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https://en.wikipedia.org/wiki/Channel%20I/O
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In computing, channel I/O is a high-performance input/output (I/O) architecture that is implemented in various forms on a number of computer architectures, especially on mainframe computers. In the past, channels were generally implemented with custom devices, variously named channel, I/O processor, I/O controller, I/O synchronizer, or DMA controller.
Overview
Many I/O tasks can be complex and require logic to be applied to the data to convert formats and other similar duties. In these situations, the simplest solution is to ask the CPU to handle the logic, but because I/O devices are relatively slow, a CPU could waste time waiting for the data from the device. This situation is called 'I/O bound'.
Channel architecture avoids this problem by processing some or all of the I/O task without the aid of the CPU by offloading the work to dedicated logic. Channels are logically self-contained, with sufficient logic and working storage to handle I/O tasks. Some are powerful or flexible enough to be used as a computer on their own and can be construed as a form of coprocessor, for example, the 7909 Data Channel on an IBM 7090 or IBM 7094; however, most are not. On some systems the channels use memory or registers addressable by the central processor as their working storage, while on other systems it is present in the channel hardware. Typically, there are standard interfaces between channels and external peripheral devices, and multiple channels can operate concurrently.
A CPU typically designates a block of storage as, or sends, a relatively small channel program to the channel in order to handle I/O tasks, which the channel and controller can, in many cases, complete without further intervention from the CPU (exception: those channel programs which utilize 'program controlled interrupts', PCIs, to facilitate program loading, demand paging and other essential system tasks).
When I/O transfer is complete or an error is detected, the controller typically communicates wi
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https://en.wikipedia.org/wiki/Gershgorin%20circle%20theorem
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In mathematics, the Gershgorin circle theorem may be used to bound the spectrum of a square matrix. It was first published by the Soviet mathematician Semyon Aronovich Gershgorin in 1931. Gershgorin's name has been transliterated in several different ways, including Geršgorin, Gerschgorin, Gershgorin, Hershhorn, and Hirschhorn.
Statement and proof
Let be a complex matrix, with entries . For let be the sum of the absolute values of the non-diagonal entries in the -th row:
Let be a closed disc centered at with radius . Such a disc is called a Gershgorin disc.
Theorem. Every eigenvalue of lies within at least one of the Gershgorin discs
Proof. Let be an eigenvalue of with corresponding eigenvector . Find i such that the element of x with the largest absolute value is . Since , in particular we take the ith component of that equation to get:
Taking to the other side:
Therefore, applying the triangle inequality and recalling that based on how we picked i,
Corollary. The eigenvalues of A must also lie within the Gershgorin discs Cj corresponding to the columns of A.
Proof. Apply the Theorem to AT while recognizing that the eigenvalues of the transpose are the same as those of the original matrix.
Example. For a diagonal matrix, the Gershgorin discs coincide with the spectrum. Conversely, if the Gershgorin discs coincide with the spectrum, the matrix is diagonal.
Discussion
One way to interpret this theorem is that if the off-diagonal entries of a square matrix over the complex numbers have small norms, the eigenvalues of the matrix cannot be "far from" the diagonal entries of the matrix. Therefore, by reducing the norms of off-diagonal entries one can attempt to approximate the eigenvalues of the matrix. Of course, diagonal entries may change in the process of minimizing off-diagonal entries.
The theorem does not claim that there is one disc for each eigenvalue; if anything, the discs rather correspond to the axes in , and each expresse
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https://en.wikipedia.org/wiki/Independence%20system
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In combinatorial mathematics, an independence system is a pair , where is a finite set and is a collection of subsets of (called the independent sets or feasible sets) with the following properties:
The empty set is independent, i.e., . (Alternatively, at least one subset of is independent, i.e., .)
Every subset of an independent set is independent, i.e., for each , we have . This is sometimes called the hereditary property, or downward-closedness.
Another term for an independence system is an abstract simplicial complex.
Relation to other concepts
A pair , where is a finite set and is a collection of subsets of is also called a hypergraph. When using this terminology, the elements in the set are called vertices and elements in the family are called hyperedges. So an independence system can be defined shortly as a downward-closed hypergraph.
An independence system with an additional property called the augmentation property or the independent set exchange property yields a matroid. The following expression summarizes the relations between the terms:HYPERGRAPHS INDEPENDENCE-SYSTEMS ABSTRACT-SIMPLICIAL-COMPLEXES MATROIDS.
References
.
Combinatorics
Hypergraphs
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https://en.wikipedia.org/wiki/Veritas%20Cluster%20Server
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Veritas Cluster Server (rebranded as Veritas Infoscale Availability and also known as VCS and also sold bundled in the SFHA product) is a high-availability cluster software for Unix, Linux and Microsoft Windows computer systems, created by Veritas Technologies. It provides application cluster capabilities to systems running other applications, including databases, network file sharing, and electronic commerce websites.
Description
High-availability clusters (HAC) improve application availability by failing or switching them over in a group of systems—as opposed to high-performance clusters, which improve application performance by running them on multiple systems simultaneously.
Most Veritas Cluster Server implementations attempt to build availability into a cluster, eliminating single points of failure by making use of redundant components like multiple network cards, storage area networks in addition to the use of VCS.
Similar products include Fujitsu PRIMECLUSTER, IBM PowerHA System Mirror, HP ServiceGuard, IBM Tivoli System Automation for Multiplatforms (SA MP), Linux-HA, OpenSAF, Microsoft Cluster Server (MSCS), NEC ExpressCluster, Red Hat Cluster Suite, SteelEye LifeKeeper and Sun Cluster. VCS is one of the few products in the industry that provides both high availability and disaster recovery across all major operating systems while supporting 40+ major application/replication technologies out of the box.
VCS is mostly a user-level clustering software; most of its processes are normal system processes on the systems it operates on, and have no special access to the operating system or kernel functions in the host systems. However, the interconnect (heartbeat) technology used with VCS is a proprietary Layer 2 ethernet-based protocol that is run in the kernel space using kernel modules. The group membership protocol that runs on top of the interconnect heartbeat protocol is also implemented in the kernel. In case of a split brain, the 'fencing' module doe
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https://en.wikipedia.org/wiki/Security%20hacker
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A security hacker is someone who explores methods for breaching defenses and exploiting weaknesses in a computer system or network. Hackers may be motivated by a multitude of reasons, such as profit, protest, information gathering, challenge, recreation, or evaluation of a system weaknesses to assist in formulating defenses against potential hackers.
Longstanding controversy surrounds the meaning of the term "hacker." In this controversy, computer programmers reclaim the term hacker, arguing that it refers simply to someone with an advanced understanding of computers and computer networks, and that cracker is the more appropriate term for those who break into computers, whether computer criminals (black hats) or computer security experts (white hats). A 2014 article noted that "the black-hat meaning still prevails among the general public". The subculture that has evolved around hackers is often referred to as the "computer underground".
History
Birth of subculture and entering mainstream: 1960s-1980s
The subculture around such hackers is termed network hacker subculture, hacker scene, or computer underground. It initially developed in the context of phreaking during the 1960s and the microcomputer BBS scene of the 1980s. It is implicated with 2600: The Hacker Quarterly and the alt.2600 newsgroup.
In 1980, an article in the August issue of Psychology Today (with commentary by Philip Zimbardo) used the term "hacker" in its title: "The Hacker Papers." It was an excerpt from a Stanford Bulletin Board discussion on the addictive nature of computer use. In the 1982 film Tron, Kevin Flynn (Jeff Bridges) describes his intentions to break into ENCOM's computer system, saying "I've been doing a little hacking here." CLU is the software he uses for this. By 1983, hacking in the sense of breaking computer security had already been in use as computer jargon, but there was no public awareness about such activities. However, the release of the film WarGames that year, featuri
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https://en.wikipedia.org/wiki/Single-particle%20spectrum
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The single-particle spectrum is a distribution of a physical quantity such as energy or momentum. The study of particle spectra allows us to see the global picture of particle production.
The spectrum are particles that are in space. This belongs to Raman spectroscopy by Chandrasekhar Venkata Raman. Spectrum particles are nothing but the VIBGYOR rays which are separated by prism or water. For example, a rainbow.
Physical quantities
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https://en.wikipedia.org/wiki/Solaris%20Cluster
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Oracle Solaris Cluster (sometimes Sun Cluster or SunCluster) is a high-availability cluster software product for Solaris, originally created by Sun Microsystems, which was acquired by Oracle Corporation in 2010. It is used to improve the availability of software services such as databases, file sharing on a network, electronic commerce websites, or other applications. Sun Cluster operates by having redundant computers or nodes where one or more computers continue to provide service if another fails. Nodes may be located in the same data center or on different continents.
Background
Solaris Cluster provides services that remain available even when individual nodes or components of the cluster fail. Solaris Cluster provides two types of HA services: failover services and scalable services.
To eliminate single points of failure, a Solaris Cluster configuration has redundant components, including multiple network connections and data storage which is multiply connected via a storage area network. Clustering software such as Solaris Cluster is a key component in a Business Continuity solution, and the Solaris Cluster Geographic Edition was created specifically to address that requirement.
Solaris Cluster is an example of kernel-level clustering software. Some of the processes it runs are normal system processes on the systems it operates on, but it does have some special access to operating system or kernel functions in the host systems.
In June 2007, Sun released the source code to Solaris Cluster via the OpenSolaris HA Clusters community.
Solaris Cluster Geographic Edition
SCGE is a management framework that was introduced in August 2005. It enables two Solaris Cluster installations to be managed as a unit, in conjunction with one or more Data replication products, to provide Disaster Recovery for a computer installation. By ensuring that data updates are continuously replicated to a remote site in near-real time, that site can rapidly take over the provision o
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https://en.wikipedia.org/wiki/Office%20of%20Atoms%20for%20Peace
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The Office of Atoms for Peace (OAP) of Thailand (สำนักงานปรมาณูเพื่อสันติ) in Chatuchak district, Bangkok, Thailand, was established in 1961 as the Office of Atomic Energy for Peace. The OAP serves as the main authority for nuclear research in Thailand. The OAP employs approximately 400 people. The research topics and services provided at the OAP include radioisotope production, gamma radiography, neutron activation analysis, neutron radiography, and gemstone irradiation.
The OAP operated a 2-megawatt nuclear research reactor, Thai Research Reactor 1/Modification 1 (TRR-1/M1). The TRR-1/M1 is of the type TRIGA Mark III, built by General Atomics, and began operation in 1962 after being commissioned in 1961 as a 1MW reactor. The TRR-1/M1 underwent its modification during 1975-1977, at which point it began operation as a 2MW reactor. TRR-1/M1 is the only nuclear reactor in Thailand.
In 2006, OAP was divided into two separate entities: the original OAP, which will oversee nuclear and radiation regulations nationally, and the new Thailand Institute of Nuclear Technology (TINT), which will conduct peaceful nuclear research and offer services to the public.
OAP functions
To be the Secretariat of the Atomic Energy for Peace Commission (AEC).
To regulate radiation safety, nuclear safety, and nuclear material.
To conduct research and development of nuclear technology.
To co-ordinate formulation of national policy and strategic plans on peaceful utilization of atomic energy.
To co-ordinate and carry out commitments and obligations with international organizations and with foreign institutes.
To co-ordinate and support national security relevant to atomic energy issues.
To co-ordinate and carry out technical co-operation with organizations in Thailand and abroad.
References
External links
Nuclear Society of Thailand
Government departments of Thailand
Nuclear technology in Thailand
Nuclear organizations
Organizations based in Bangkok
Government agencies establishe
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https://en.wikipedia.org/wiki/Constraint%20counting
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In mathematics, constraint counting is counting the number of constraints in order to compare it with the number of variables, parameters, etc. that are free to be determined, the idea being that in most cases the number of independent choices that can be made is the excess of the latter over the former.
For example, in linear algebra if the number of constraints (independent equations) in a system of linear equations equals the number of unknowns then precisely one solution exists; if there are fewer independent equations than unknowns, an infinite number of solutions exist; and if the number of independent equations exceeds the number of unknowns, then no solutions exist.
In the context of partial differential equations, constraint counting is a crude but often useful way of counting the number of free functions needed to specify a solution to a partial differential equation.
Partial differential equations
Consider a second order partial differential equation in three variables, such as the two-dimensional wave equation
It is often profitable to think of such an equation as a rewrite rule allowing us to rewrite arbitrary partial derivatives of the function using fewer partials than would be needed for an arbitrary function. For example, if satisfies the wave equation, we can rewrite
where in the first equality, we appealed to the fact that partial derivatives commute.
Linear equations
To answer this in the important special case of a linear partial differential equation, Einstein asked: how many of the partial derivatives of a solution can be linearly independent? It is convenient to record his answer using an ordinary generating function
where is a natural number counting the number of linearly independent partial derivatives (of order k) of an arbitrary function in the solution space of the equation in question.
Whenever a function satisfies some partial differential equation, we can use the corresponding rewrite rule to eliminate some of them, b
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https://en.wikipedia.org/wiki/Direction%20cosine
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In analytic geometry, the direction cosines (or directional cosines) of a vector are the cosines of the angles between the vector and the three positive coordinate axes. Equivalently, they are the contributions of each component of the basis to a unit vector in that direction.
Three-dimensional Cartesian coordinates
If v is a Euclidean vector in three-dimensional Euclidean space, R3,
where ex, ey, ez are the standard basis in Cartesian notation, then the direction cosines are
It follows that by squaring each equation and adding the results
Here α, β and γ are the direction cosines and the Cartesian coordinates of the unit vector v/|v|, and a, b and c are the direction angles of the vector v.
The direction angles a, b and c are acute or obtuse angles, i.e., 0 ≤ a ≤ π, 0 ≤ b ≤ π and 0 ≤ c ≤ π, and they denote the angles formed between v and the unit basis vectors, ex, ey and ez.
General meaning
More generally, direction cosine refers to the cosine of the angle between any two vectors. They are useful for forming direction cosine matrices that express one set of orthonormal basis vectors in terms of another set, or for expressing a known vector in a different basis.
See also
Cartesian tensor
References
Algebraic geometry
Vectors (mathematics and physics)
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https://en.wikipedia.org/wiki/Signed%20graph
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In the area of graph theory in mathematics, a signed graph is a graph in which each edge has a positive or negative sign.
A signed graph is balanced if the product of edge signs around every cycle is positive. The name "signed graph" and the notion of balance appeared first in a mathematical paper of Frank Harary in 1953. Dénes Kőnig had already studied equivalent notions in 1936 under a different terminology but without recognizing the relevance of the sign group.
At the Center for Group Dynamics at the University of Michigan, Dorwin Cartwright and Harary generalized Fritz Heider's psychological theory of balance in triangles of sentiments to a psychological theory of balance in signed graphs.
Signed graphs have been rediscovered many times because they come up naturally in many unrelated areas. For instance, they enable one to describe and analyze the geometry of subsets of the classical root systems. They appear in topological graph theory and group theory. They are a natural context for questions about odd and even cycles in graphs. They appear in computing the ground state energy in the non-ferromagnetic Ising model; for this one needs to find a largest balanced edge set in Σ. They have been applied to data classification in correlation clustering.
Fundamental theorem
The sign of a path is the product of the signs of its edges. Thus a path is positive only if there are an even number of negative edges in it (where zero is even). In the mathematical balance theory of Frank Harary, a signed graph is balanced when every cycle is positive. Harary proves that a signed graph is balanced when (1) for every pair of nodes, all paths between them have the same sign, or (2) the vertices partition into a pair of subsets (possibly empty), each containing only positive edges, but connected by negative edges. It generalizes the theorem that an ordinary (unsigned) graph is bipartite if and only if every cycle has even length.
A simple proof uses the method of switchi
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https://en.wikipedia.org/wiki/Colored%20matroid
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In mathematics, a colored matroid is a matroid whose elements are labeled from a set of colors, which can be any set that suits the purpose, for instance the set of the first n positive integers, or the sign set {+, −}.
The interest in colored matroids is through their invariants, especially the colored Tutte polynomial, which generalizes the Tutte polynomial of a signed graph of .
There has also been study of optimization problems on matroids where the objective function of the optimization depends on the set of colors chosen as part of a matroid basis.
See also
Bipartite matroid
Rota's basis conjecture
References
Matroid theory
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https://en.wikipedia.org/wiki/Biased%20graph
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In mathematics, a biased graph is a graph with a list of distinguished circles (edge sets of simple cycles), such that if two circles in the list are contained in a theta graph, then the third circle of the theta graph is also in the list. A biased graph is a generalization of the combinatorial essentials of a gain graph and in particular of a signed graph.
Formally, a biased graph Ω is a pair (G, B) where B is a linear class of circles; this by definition is a class of circles that satisfies the theta-graph property mentioned above.
A subgraph or edge set whose circles are all in B (and which contains no half-edges) is called balanced. For instance, a circle belonging to B is balanced and one that does not belong to B is unbalanced.
Biased graphs are interesting mostly because of their matroids, but also because of their connection with multiary quasigroups. See below.
Technical notes
A biased graph may have half-edges (one endpoint) and loose edges (no endpoints). The edges with two endpoints are of two kinds: a link has two distinct endpoints, while a loop has two coinciding endpoints.
Linear classes of circles are a special case of linear subclasses of circuits in a matroid.
Examples
If every circle belongs to B, and there are no half-edges, Ω is balanced. A balanced biased graph is (for most purposes) essentially the same as an ordinary graph.
If B is empty, Ω is called contrabalanced. Contrabalanced biased graphs are related to bicircular matroids.
If B consists of the circles of even length, Ω is called antibalanced and is the biased graph obtained from an all-negative signed graph.
The linear class B is additive, that is, closed under repeated symmetric difference (when the result is a circle), if and only if B is the class of positive circles of a signed graph.
Ω may have underlying graph that is a cycle of length n ≥ 3 with all edges doubled. Call this a biased 2Cn . Such biased graphs in which no digon (circle of length 2) is balanced
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https://en.wikipedia.org/wiki/Vapour%20phase%20decomposition
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Vapour phase decomposition (VPD) is a method used in the semiconductor industry to improve the sensitivity of total-reflection x-ray fluorescence spectroscopy by changing the contaminant from a thin layer (which has an angle-dependent fluorescence intensity in the TXRF-domain) to a granular residue. When using granular residue the limits of detection are improved because of a more intense fluorescence signal in angles smaller than the isokinetic angle.
Method
When using granular residue the limits of detection are improved because of a more intense fluorescence signal in angles smaller than the isokinetic angle. This can be achieved by enhancing the impurity concentration in the solution to be analyzed. In standard atomic absorption spectroscopy (AAS), the impurity is dissolved together with the matrix element. In VPD, the surface of the wafer is exposed to hydrofluoric acid vapour, which causes the surface oxide to dissolve together with the impurity metals. The acid droplets, condensed on the surface, are then analyzed using AAS.
Advantages
The method has yielded good results for the detection and measurement of nickel and iron. To improve the range of elemental impurities and lower detection limits, the acid droplets obtained from the silicon wafers are analyzed by ICP-MS (Inductively coupled plasma mass spectrometry). This technique, VPD ICP-MS provides accurate measurement of up to 60 elements and detection limits of in the range of 1E6-E10 atoms/sq.cm on the silicon wafer.
Related Techniques
One related technique is VPD-DC (vapour phase decomposition-droplet collection), where the wafer is scanned with a droplet that collects the metal ions that were dissolved in the decomposition step. This procedure affords better limits of detection when applying AAS in order to detect metal impurities of very small concentrations on wafer surfaces.
References
Semiconductor device fabrication
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https://en.wikipedia.org/wiki/Manual%20override
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A manual override (MO) or manual analog override (MAO) is a mechanism where control is taken from an automated system and given to the user. For example, a manual override in photography refers to the ability for the human photographer to turn off the automatic aperture sizing, automatic focusing, or any other automated system on the camera.
Some manual overrides can be used to veto an automated system's judgment when the system is in error. An example of this is a printer's ink level detection: in one case, a researcher found that when he overrode the system, up to 38% more pages could be printed at good quality by the printer than the automated system would have allowed.
Automated systems are becoming increasingly common and integrated into everyday objects such as automobiles and domestic appliances. This development of ubiquitous computing raises general issues of policy and law about the need for manual overrides for matters of great importance such as life-threatening situations and major economic decisions. The loyalty of such autonomous devices then becomes an issue. If they follow rules installed by the manufacturer or required by law and refuse to cede control in some situations then the owners of the devices may feel disempowered, alienated and lacking true ownership.
Major incidents
China Airlines Flight 140 crashed, causing many deaths, due to a misunderstanding about the manual overrides for the autopilot. The Take-Off/Go Around system had been activated to abort a landing. It was programmed to ignore manual controls in this situation but the human pilots tried to continue the landing. The conflicting control signals from the pilots and autopilot then resulted in the aircraft stalling and crashing. The autopilot for this aircraft type was then reprogrammed so that it would never ignore a manual override.
See also
Big red button
Communication cord
Dead man's handle
Engine control unit (ECU)
Full authority digital engine (or electronics) contr
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https://en.wikipedia.org/wiki/HD%20ready
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HD ready is a certification program introduced in 2005 by EICTA (European Information, Communications and Consumer Electronics Technology Industry Associations), now DIGITALEUROPE. HD ready minimum native resolution is 720 rows in widescreen ratio.
There are currently four different labels: "HD ready", "HD TV", "HD ready 1080p", "HD TV 1080p". The logos are assigned to television equipment capable of certain features.
In the United States, a similar "HD Ready" term usually refers to any display that is capable of accepting and displaying a high-definition signal at either 720p, 1080i or 1080p using a component video or digital input, but does not have a built-in HD-capable tuner.
History
The "HD ready" certification program was introduced on January 19, 2005. The labels and relevant specifications are based on agreements between over 60 broadcasters and manufacturers of the European HDTV Forum at its second session in June 2004, held at the Betzdorf, Luxembourg headquarters of founding member SES Astra.
The "HD ready" logo is used on television equipment capable of displaying High Definition (HD) pictures from an external source. However, it does not have to feature a digital tuner to decode an HD signal; devices with tuners were certified under a separate "HD TV" logo, which does not require a "HD ready" display device.
Before the introduction of the "HD ready" certification, many TV sources and displays were being promoted as capable of displaying high definition pictures when they were in fact SDTV devices; according to Alexander Oudendijk, senior VP of marketing for Astra, in early 2005 there were 74 different devices being sold as ready for HD that were not. Devices advertised as HD-compatible or HD ready could take HDTV-signal as an input (via analog -YPbPr or digital DVI or HDMI), but they did not have enough pixels for true representation of even the lower HD resolution (1280 × 720) (plasma-based sets with 853 × 480 resolution, CRT based sets only capa
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https://en.wikipedia.org/wiki/Ball%20and%20beam
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The ball and beam system consists of a long beam which can be tilted by a servo or electric motor together with a ball
rolling back and forth on top of the beam.
It is a popular textbook example in control theory.
The significance of the ball and beam system is that it is a simple system which is open-loop unstable.
Even if the beam is restricted to be very nearly horizontal, without active feedback, it will swing to one side or the
other, and the ball will roll off the end of the beam. To stabilize the ball, a control system which
measures the position of the ball and adjusts the beam accordingly must be used.
In two dimensions, the ball and beam system becomes the ball and plate system, where a ball rolls on top of
a plate whose inclination can be adjusted by tilting it forwards, backwards, leftwards, or rightwards.
External links
Ball and beam with various controls strategies
Ball and beam 1: basics
Ball and beam with comprehensive dynamics and movies
Control engineering
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https://en.wikipedia.org/wiki/Institut%20f%C3%BCr%20Rundfunktechnik
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The GmbH (IRT) (Institute for Broadcasting Technology Ltd.) was a research centre of German broadcasters (ARD / ZDF / DLR), Austria's broadcaster (ORF) and the Swiss public broadcaster (SRG / SSR). It was responsible for research on broadcasting technology. It was founded in 1956 and was located in Munich, Germany.
They invented or were influential in the research, development and field-testing of important standards such as ARI, RDS, VPS, DSR, DAB and DVB-T.
was a founding member of the Hybrid Broadcast Broadband TV (HbbTV) consortium of broadcasting and Internet industry companies that established an open European standard (called HbbTV) for hybrid set-top boxes for the reception of broadcast TV and broadband multimedia applications with a single user interface.
In 2020, ZDF and then other supporters indicated that they planned to withdraw from the organization, so the IRT was closed by the end of 2020.
Former members
Bayerischer Rundfunk
Deutsche Welle
Deutschlandradio
Hessischer Rundfunk
Mitteldeutscher Rundfunk
Norddeutscher Rundfunk
Radio Bremen
Rundfunk Berlin-Brandenburg
Saarländischer Rundfunk
SRG SSR
Südwestrundfunk
Westdeutscher Rundfunk Köln
ZDF
See also
BBC Research & Development
High Com FM (researched and field-trialed by IRT between 1979 and 1984)
Wittmoor List (maintained by IRT up to June 2018)
European Broadcasting Union (EBU)
International Telecommunication Union (ITU)
DVB Project
WorldDAB
Public broadcasting
Teletext
(FTZ)
(RFZ)
(IVZ)
References
Further reading
External links
https://web.archive.org/web/20210430071454/https://www.irt.de/en/home
https://web.archive.org/web/20210430023055/https://www.irt.de/de/publikationen/technische-richtlinien/technische-richtlinien-archiv Technical guidelines
ARD (broadcaster)
International research institutes
Information technology research institutes
1956 establishments in West Germany
2020 disestablishments in Germany
Radio technology
Research institutes in Munic
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https://en.wikipedia.org/wiki/Phil%20Karn
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Phil Karn (born October 4, 1956) is a retired American engineer from Lutherville, Maryland. He earned a bachelor's degree in electrical engineering from Cornell University in 1978 and a master's degree in electrical engineering from Carnegie Mellon University in 1979. From 1979 until 1984, Karn worked at Bell Labs in Naperville, Illinois, and Murray Hill, New Jersey. From 1984 until 1991, he was with Bell Communications Research in Morristown, New Jersey. From 1991 through to his retirement, he worked at Qualcomm in San Diego, where he specialized in wireless data networking protocols, security, and cryptography.
He is currently the President/CEO of Amateur Radio Digital Communications (ARDC), a non-profit foundation funded by the sale of part of its IP address space (44/8). ARDC manages the remaining portion of its address space by providing financial grants to amateur radio and related groups.
He has been an active contributor in the Internet Engineering Task Force, especially in security, and to the Internet architecture. He is the author or co-author of at least 6 RFCs, and is cited as contributing to many more. He is the inventor of Karn's Algorithm, a method for calculating the round trip time for IP packet retransmission. In 1991, Thomas Alexander Iannelli's Master's thesis judged Karn's KA9Q NOS software as more suitable for deployment than an Air Force Institute of Technology packet radio system. In 1990, Karn was one of the first to predict that the use of wired links for the Internet's "capillaries" would become "history" because most users would access it via wireless radio links.
In 1994, Carl Malamud interviewed Karn on Internet Talk Radio for his "Geek of the Week" podcast. They talked about the KA9Q software, Qualcomm's CDMA radio technology for data transfer, the Globalstar low Earth orbit satellite radio system, Mobile IP, the Clipper chip, and encryption. In June 2014, Karn was also interviewed for the History of the Internet Project, in w
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https://en.wikipedia.org/wiki/Pcap
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In the field of computer network administration, pcap is an application programming interface (API) for capturing network traffic. While the name is an abbreviation of packet capture, that is not the API's proper name. Unix-like systems implement pcap in the libpcap library; for Windows, there is a port of libpcap named WinPcap that is no longer supported or developed, and a port named Npcap for Windows 7 and later that is still supported.
Monitoring software may use libpcap, WinPcap, or Npcap to capture network packets traveling over a computer network and, in newer versions, to transmit packets on a network at the link layer, and to get a list of network interfaces for possible use with libpcap, WinPcap, or Npcap.
The pcap API is written in C, so other languages such as Java, .NET languages, and scripting languages generally use a wrapper; no such wrappers are provided by libpcap or WinPcap itself. C++ programs may link directly to the C API or make use of an object-oriented wrapper.
Features
libpcap, WinPcap, and Npcap provide the packet-capture and filtering engines of many open-source and commercial network tools, including protocol analyzers (packet sniffers), network monitors, network intrusion detection systems, traffic-generators and network-testers.
libpcap, WinPcap, and Npcap also support saving captured packets to a file, and reading files containing saved packets; applications can be written, using libpcap, WinPcap, or Npcap, to be able to capture network traffic and analyze it, or to read a saved capture and analyze it, using the same analysis code. A capture file saved in the format that libpcap, WinPcap, and Npcap use can be read by applications that understand that format, such as tcpdump, Wireshark, CA NetMaster, or Microsoft Network Monitor 3.x.
The MIME type for the file format created and read by libpcap, WinPcap, and Npcap is application/vnd.tcpdump.pcap. The typical file extension is .pcap, although .cap and .dmp are also in common use.
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https://en.wikipedia.org/wiki/Dial%20%28measurement%29
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A dial is generally a flat surface, circular or rectangular, with numbers or similar markings on it, used for displaying the setting or output of a timepiece, radio, clock, watch, or measuring instrument. There are many instruments used in scientific and industrial applications that use dials with pointers as indicators of a specific physical property. Typical examples include pressure and vacuum gauges, fluid-level gauges (for fuel, engine oil, and so on), voltmeters and ammeters, thermometers and hygrometers, speedometers and tachometers, and indicators (distance amplifying instruments).
Traditionally these have been mechanical devices, but with the advent of electronic displays, analog dials are often simulated from digital measurements.
The term may also refer to a movable control knob used to change the settings of the controlled instrument, for example, to change the frequency of the radio, or the desired temperature on a thermostat.
Styles of dials:
Circular,
Fixed pointer with moving scale,
Fixed scale with moving dial.
Examples of dial usage:
Pressure and vacuum gauges,
Level gauges,
Volt and current meters,
Thermometers and thermostats (mechanical),
Speedometers and tachometers.
Mirror dials are designed to reduce or eliminate the effect of parallax. They usually consist of a small mirrored strip running parallel to the graduations of the scale under the pointer. When the observer moves his position so that the pointer obscures the pointer's reflection in the mirror, an accurate reading may be taken.
See also
Dial (disambiguation)
Sundial
Measuring instruments
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https://en.wikipedia.org/wiki/Control%20knob
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A control knob is a rotary device used to provide manual input adjustments to a mechanical/electrical system when grasped and turned by a human operator, so that differing extent of knob rotation corresponds to different desired input. Control knobs are a simpler type of input hardware and one of the most common components in control systems, and are found on all sorts of devices from taps and gas stoves to optical microscopes, potentiometers, radio tuners and digital cameras, as well as in aircraft cockpits.
Operation
A control knob works by turning a shaft which connects to the component which produces the actual input. Common control components used include potentiometers, variable capacitors, and rotary switches. An example where the knob does not produce a variation in an electrical signal may be found in many toasters, where the darkness knob moves the thermostat in such a way as to change the temperature at which it opens and releases the cooked toast. Some similar controls produce similar inputs using different geometry; for example, the knob may be replaced by a lever which is moved through an angle. Another example is the sliding controls which frequently replace knobs as level controls in audio equipment.
Feedback
The use of knobs is an important aspect of the design of user interfaces in these devices. Particular attention needs to be paid to the feedback to the operator from the adjustments being made. The use of a pointer on the knob in conjunction with a scale assists in producing repeatable settings; in other cases there may be a dial or other indicator which is either mechanically linked the knob's rotation (as in many older radio tuners) or which reports the behavior being controlled.
Examples
References
Control devices
Human–machine interaction
Electrical components
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https://en.wikipedia.org/wiki/Proactive%20maintenance
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Proactive maintenance is the maintenance philosophy that supplants “failure reactive” with “failure proactive” by activities that avoid the underlying conditions that lead to machine faults and degradation. Unlike predictive or preventive maintenance, proactive maintenance commissions corrective actions aimed at failure root causes, not failure symptoms. Its central theme is to extend the life of machinery as opposed to
making repairs when often nothing is wrong,
accommodating failure as routine or normal, or
detecting impending failure conditions followed by remediation.
Proactive maintenance depends on rigorous machine inspection and condition monitoring. In mechanical machinery it seeks to detect and eradicate failure root causes such as wrong lubricant, degraded lubricant, contaminated lubricant, botched repair, misalignment, unbalance and operator error.
See also
Predictive maintenance
References
Mechanical engineering
Maintenance
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https://en.wikipedia.org/wiki/ProQuest%20Dialog
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Dialog is an online information service owned by ProQuest, who acquired it from Thomson Reuters in mid-2008.
Dialog was one of the predecessors of the World Wide Web as a provider of information, though not in form. The earliest form of the Dialog system was completed in 1966 in Lockheed Martin under the direction of Roger K. Summit. According to its literature, it was "the world's first online information retrieval system to be used globally with materially significant databases". In the 1980s, a low-priced dial-up version of a subset of Dialog was marketed to individual users as Knowledge Index. This subset included INSPEC, MathSciNet, over 200 other bibliographic and reference databases, as well as third-party retrieval vendors who would go to physical libraries to copy materials for a fee and send it to the service subscriber.
While being owned by the Thomson Corporation, Dialog consisted of the Dialog, DataStar, Profound, and NewsEdge businesses. Dialog and DataStar were consolidated into Dialog. The news content from Profound and NewsEdge were consolidated, and the market research business from Profound was sold to MarketResearch.com. The NewsEdge business was eventually sold to Acquire Media, now Naviga. Prior to being owned by Thomson, MAID purchased Knight-Ridder Information which included the Dialog and DataStar businesses. MAID renamed itself to be the Dialog Corporation.
See also
Colorado Alliance of Research Libraries
References
External links
Dialog Solutions
Dialog
Former assets of Thomson Reuters
Online databases
Online companies of the United States
Bibliographic databases and indexes
Patent search services
Pre–World Wide Web online services
Full-text scholarly online databases
Scholarly search services
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https://en.wikipedia.org/wiki/Epsilon-induction
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In set theory, -induction, also called epsilon-induction or set-induction, is a principle that can be used to prove that all sets satisfy a given property. Considered as an axiomatic principle, it is called the axiom schema of set induction.
The principle implies transfinite induction and recursion.
It may also be studied in a general context of induction on well-founded relations.
Statement
The schema is for any given property of sets and states that, if for every set , the truth of follows from the truth of for all elements of , then this property holds for all sets.
In symbols:
Note that for the "bottom case" where denotes the empty set , the subexpression is vacuously true for all propositions and so that implication is proven by just proving .
In words, if a property is persistent when collecting any sets with that property into a new set (and this also requires establishing the property for the empty set), then the property is simply true for all sets. Said differently, persistence of a property with respect to set formation suffices to reach each set in the domain of discourse.
In terms of classes
One may use the language of classes to express schemata.
Denote the universal class by .
Let be and use the informal as abbreviation for .
The principle then says that for any ,
Here the quantifier ranges over all sets.
In words this says that any class that contains all of its subsets is simply just the class of all sets.
Assuming bounded separation, is a proper class. So the property is exhibited only by the proper class , and in particular by no set. Indeed, note that any set is a subset of itself and under some more assumptions, already the self-membership will be ruled out.
For comparison to another property, note that for a class to be -transitive means
There are many transitive sets - in particular the set theoretical ordinals.
Related notions of induction
If is for some predicate , then with ,
where is defined as .
If is
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https://en.wikipedia.org/wiki/Zuiyo-maru%20carcass
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The was a corpse, caught by the Japanese fishing trawler off the coast of New Zealand in 1977. The carcass's peculiar appearance led to speculation that it might be the remains of a sea serpent or prehistoric plesiosaur.
Although several scientists insisted it was "not a fish, whale, or any other mammal", analysis of amino acids in the corpse's muscle tissue later indicated it was most likely the carcass of a basking shark. Decomposing basking shark carcasses lose most of the lower head area and the dorsal and caudal fins first, making them resemble a plesiosaur.
Discovery
On April 25, 1977, the Japanese trawler Zuiyō Maru, sailing east of Christchurch, New Zealand, caught a strange, unknown creature in the trawl. The crew was convinced it was an unidentified animal, but despite the potential biological significance of the curious discovery, the captain, Akira Tanaka, decided to dump the carcass into the ocean again so not to risk spoiling the caught fish. However, before that, some photos and sketches were taken of the creature, nicknamed "Nessie" by the crew, measurements were taken and some samples of skeleton, skin and fins were collected for further analysis by experts in Japan. The discovery resulted in immense commotion and a "plesiosaur-craze" in Japan, and the shipping company ordered all its boats to try to relocate the dumped corpse, but with no apparent success.
Description
The foul-smelling, decomposing corpse reportedly weighed 1,800 kg and was about 10 m long. According to the crew, the creature had a 1.5-m-long neck, four large, reddish fins, and a tail about 2.0 m long. It seemed to lack a dorsal fin on inspection, but one was visible from photographs. No internal organs remained as the chest cavity and gut had opened up from decay, but flesh and fat were somewhat intact.
Proposed explanations
Plesiosaur
Professor Tokio Shikama from Yokohama National University was convinced the remains were of a supposedly extinct plesiosaur. Dr. Fujiro
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https://en.wikipedia.org/wiki/Lambda%20transition
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The λ (lambda) universality class is a group in condensed matter physics. It regroups several systems possessing strong analogies, namely, superfluids, superconductors and smectics (liquid crystals). All these systems are expected to belong to the same universality class for the thermodynamic critical properties of the phase transition. While these systems are quite different at the first glance, they all are described by similar formalisms and their typical phase diagrams are identical.
See also
Superfluid
Superconductor
Liquid crystal
Phase transition
Renormalization group
Topological defect
References
Books
Chaikin P. M. and Lubensky T. C. Principles of Condensed Matter Physics (Cambridge University Press, Cambridge) 1995, sect.9.
Feynman R. P. Progress in Low Temperature Physics Vol.1, edited by C. Gorter (North Holland, Amsterdam) 1955.
Journal articles
Translated as:
Condensed matter physics
Critical phenomena
Phase transitions
Phases of matter
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https://en.wikipedia.org/wiki/Musipedia
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Musipedia is a search engine for identifying pieces of music. This can be done by whistling a theme, playing it on a virtual piano keyboard, tapping the rhythm on the computer keyboard, or entering the Parsons code. Anybody can modify the collection of melodies and enter MIDI files, bitmaps with sheet music (possibly generated by the Musipedia server after entering LilyPond or abc source code), lyrics or some text about the piece, or the melodic contours as Parsons Code. Certain features on the site may no longer work due to reliance on flash which became defunct in 2020.
Search principles
Musipedia offers three ways of searching: Based on the melodic contour, based on pitches and onset times, or based on the rhythm alone. For the first two, users can draw notes, play them on a keyboard, or type out an ASCII version of a melody.
Melody
The melodic contour search uses an editing distance. Because of this, the search engine finds not only entries with exactly the contour that is entered as a query, but also the most similar ones among the contours that are not identical. The similarity is measured by determining the editing steps (inserting, deleting, or replacing a character) that are needed for converting the query contour into that of the search result. Since only the melodic contour is relevant, one can find melodies even if the key, rhythm, or the exact intervals are unknown.
Pitch and rhythm
The pitch and onset time-based search takes more properties of the melody into account. This search method, which is used by default, is still transposition-invariant and tempo-invariant, but it takes rhythm and intervals into account. The melody can be entered in various ways, for example by clicking on a virtual keyboard on the screen. The search engine then segments the query, converts each segment into a set of points in the two-dimensional space of onset time and pitch, and, by using the Earth Mover's Distance, compares each point set to pre-computed point sets re
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https://en.wikipedia.org/wiki/Seccomp
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seccomp (short for secure computing mode) is a computer security facility in the Linux kernel. seccomp allows a process to make a one-way transition into a "secure" state where it cannot make any system calls except exit(), sigreturn(), read() and write() to already-open file descriptors. Should it attempt any other system calls, the kernel will either just log the event or terminate the process with SIGKILL or SIGSYS. In this sense, it does not virtualize the system's resources but isolates the process from them entirely.
seccomp mode is enabled via the system call using the PR_SET_SECCOMP argument, or (since Linux kernel 3.17) via the system call. seccomp mode used to be enabled by writing to a file, /proc/self/seccomp, but this method was removed in favor of prctl(). In some kernel versions, seccomp disables the RDTSC x86 instruction, which returns the number of elapsed processor cycles since power-on, used for high-precision timing.
seccomp-bpf is an extension to seccomp that allows filtering of system calls using a configurable policy implemented using Berkeley Packet Filter rules. It is used by OpenSSH and vsftpd as well as the Google Chrome/Chromium web browsers on ChromeOS and Linux. (In this regard seccomp-bpf achieves similar functionality, but with more flexibility and higher performance, to the older systrace—which seems to be no longer supported for Linux.)
Some consider seccomp comparable to OpenBSD pledge(2) and FreeBSD capsicum(4).
History
seccomp was first devised by Andrea Arcangeli in January 2005 for use in public grid computing and was originally intended as a means of safely running untrusted compute-bound programs. It was merged into the Linux kernel mainline in kernel version 2.6.12, which was released on March 8, 2005.
Software using seccomp or seccomp-bpf
Android uses a seccomp-bpf filter in the zygote since Android 8.0 Oreo.
systemd's sandboxing options are based on seccomp.
QEMU, the Quick Emulator, the core component to the
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https://en.wikipedia.org/wiki/Atari%20Mindlink
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The Atari Mindlink is an unreleased video game controller for the Atari 2600, originally intended for release in 1984. The Mindlink was unique in that its headband form factor controls the game by reading the myoneural signal voltage from the player's forehead. The player's forehead movements are read by infrared sensors and transferred as movement in the game.
Specially supported games are similar to those that use the paddle controller, but with the Mindlink controller instead. Three games were in development for the Mindlink by its cancellation: Bionic Breakthrough, Telepathy, and Mind Maze. Bionic Breakthrough is basically a Breakout clone, controlled with the Mindlink. Mind Maze uses the Mindlink for a mimicry of ESP, to pretend to predict what is printed on cards. Testing showed that players frequently got headaches due to moving their eyebrows to play the game. None of these games were ever released in any other form.
References
Mindlink
Vaporware
Game controllers
Brain–computer interfacing
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https://en.wikipedia.org/wiki/StrongSwan
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strongSwan is a multiplatform IPsec implementation. The focus of the project is on authentication mechanisms using X.509 public key certificates and optional storage of private keys and certificates on smartcards through a PKCS#11 interface and on TPM 2.0.
Overview
The project is maintained by Andreas Steffen who is a professor emeritus for Security in Communications with the University of Applied Sciences in Rapperswil, Switzerland.
As a descendant of the FreeS/WAN project, strongSwan continues to be released under the GPL license. It supports certificate revocation lists and the Online Certificate Status Protocol (OCSP). A unique feature is the use of X.509 attribute certificates to implement access control schemes based on group memberships. StrongSwan interoperates with other IPsec implementations, including various Microsoft Windows and macOS VPN clients. The current version of strongSwan fully implements the Internet Key Exchange (IKEv2) protocol defined by RFC 7296.
Features
strongSwan supports IKEv1 and fully implements IKEv2.
IKEv1 and IKEv2 features
strongSwan offers plugins, enhancing its functionality. The user can choose among three crypto libraries (legacy [non-US] FreeS/WAN, OpenSSL, and gcrypt).
Using the openssl plugin, strongSwan supports Elliptic Curve Cryptography (ECDH groups and ECDSA certificates and signatures) both for IKEv2 and IKEv1, so that interoperability with Microsoft's Suite B implementation on Vista, Win 7, Server 2008, etc. is possible.
Automatic assignment of virtual IP addresses to VPN clients from one or several address pools using either the IKEv1 ModeConfig or IKEv2 Configuration payload. The pools are either volatile (i.e. RAM-based) or stored in a SQLite or MySQL database (with configurable lease-times).
The ipsec pool command line utility allows the management of IP address pools and configuration attributes like internal DNS and NBNS servers.
IKEv2 only features
The IKEv2 daemon is inherently multi-threaded (16
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https://en.wikipedia.org/wiki/Reliability%2C%20availability%20and%20serviceability
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Reliability, availability and serviceability (RAS), also known as reliability, availability, and maintainability (RAM), is a computer hardware engineering term involving reliability engineering, high availability, and serviceability design. The phrase was originally used by International Business Machines (IBM) as a term to describe the robustness of their mainframe computers.
Computers designed with higher levels of RAS have many features that protect data integrity and help them stay available for long periods of time without failure This data integrity and uptime is a particular selling point for mainframes and fault-tolerant systems.
Definitions
While RAS originated as a hardware-oriented term, systems thinking has extended the concept of reliability-availability-serviceability to systems in general, including software.
Reliability can be defined as the probability that a system will produce correct outputs up to some given time t. Reliability is enhanced by features that help to avoid, detect and repair hardware faults. A reliable system does not silently continue and deliver results that include uncorrected corrupted data. Instead, it detects and, if possible, corrects the corruption, for example: by retrying an operation for transient (soft) or intermittent errors, or else, for uncorrectable errors, isolating the fault and reporting it to higher-level recovery mechanisms (which may failover to redundant replacement hardware, etc.), or else by halting the affected program or the entire system and reporting the corruption. Reliability can be characterized in terms of mean time between failures (MTBF), with reliability = exp(-t/MTBF).
Availability means the probability that a system is operational at a given time, i.e. the amount of time a device is actually operating as the percentage of total time it should be operating. High-availability systems may report availability in terms of minutes or hours of downtime per year. Availability features allow the
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https://en.wikipedia.org/wiki/Meniscal%20cyst
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Meniscal cyst is a well-defined cystic lesion located along the peripheral margin of the meniscus, a part of the knee, nearly always associated with horizontal meniscal tears.
Signs and symptoms
Pain and swelling or focal mass at the level of the joint. The pain may be related to a meniscal tear or distension of the knee capsule or both. The mass varies in consistency from soft/fluctuant to hard. Size is variable, and meniscal cysts are known to change in size with knee flexion/extension.
Cause
Various etiologies have been proposed, including trauma, hemorrhage, chronic infection, and mucoid degeneration. The most widely accepted theory describes meniscal cysts resulting from extrusion of synovial fluid through a peripherally extended horizontal meniscal tear, accumulating outside the joint capsule. They arise more commonly from the lateral joint margin, and occur most often in 20- to 40-year-old males.
Diagnosis
Magnetic resonance imaging is the modality of choice for diagnosis of meniscal cysts. In their most subtle form, meniscal cysts present as focal areas of high signal intensity within a swollen meniscus. It is not uncommon for radiologists to miss this type of meniscal cyst because the signal intensity is not quite as great as fluid on T2 weighted sequences.2 When this fluid is extruded into the adjacent soft tissues, the swollen meniscus subsequently assumes a more normal shape, and the extruded fluid demonstrates a higher T2 signal typical of parameniscal cysts.
Medial meniscus horizontal tear extending into a meniscal cyst.
Sagittal T2 images of a medial meniscus horizontal tear extending into a meniscal cyst.
Large medial meniscus cyst.
Treatment
Treatment of meniscal cysts consists of a combination of cyst decompression (intraarticular decompression versus open cystectomy) and arthroscopic repair of any meniscal abnormalities. Success rates are significantly higher when both the cyst and meniscal tear are treated compared to treating only one di
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https://en.wikipedia.org/wiki/Singly%20and%20doubly%20even
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In mathematics an even integer, that is, a number that is divisible by 2, is called evenly even or doubly even if it is a multiple of 4, and oddly even or singly even if it is not. The former names are traditional ones, derived from ancient Greek mathematics; the latter have become common in recent decades.
These names reflect a basic concept in number theory, the 2-order of an integer: how many times the integer can be divided by 2. This is equivalent to the multiplicity of 2 in the prime factorization.
A singly even number can be divided by 2 only once; it is even but its quotient by 2 is odd.
A doubly even number is an integer that is divisible more than once by 2; it is even and its quotient by 2 is also even.
The separate consideration of oddly and evenly even numbers is useful in many parts of mathematics, especially in number theory, combinatorics, coding theory (see even codes), among others.
Definitions
The ancient Greek terms "even-times-even" () and "even-times-odd" ( or ) were given various inequivalent definitions by Euclid and later writers such as Nicomachus. Today, there is a standard development of the concepts. The 2-order or 2-adic order is simply a special case of the p-adic order at a general prime number p; see p-adic number for more on this broad area of mathematics. Many of the following definitions generalize directly to other primes.
For an integer n, the 2-order of n (also called valuation) is the largest natural number ν such that 2ν divides n. This definition applies to positive and negative numbers n, although some authors restrict it to positive n; and one may define the 2-order of 0 to be infinity (see also parity of zero). The 2-order of n is written ν2(n) or ord2(n). It is not to be confused with the multiplicative order modulo 2.
The 2-order provides a unified description of various classes of integers defined by evenness:
Odd numbers are those with ν2(n) = 0, i.e., integers of the form .
Even numbers are those with ν2(n) > 0
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https://en.wikipedia.org/wiki/Army%20Moves
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Army Moves is a scrolling shooter game developed by Dinamic Software for the Amiga, Amstrad CPC, Atari ST, Commodore 64, MSX and ZX Spectrum. It is the first chapter of the Moves Trilogy and it was followed by Navy Moves in 1987 and Arctic Moves in 1995. It was first released in 1986 and published by Dinamic in Spain and by Imagine Software. Dinamic Software also developed a MS-DOS version of the game, published in 1989 in Spain.
Gameplay
The game contains seven levels that are divided into two main sections. The first four levels make up the first section, where the player has to drive an army unit (jeep or helicopter) through a terrain, steering clear of hostile vehicles.
In the last three levels that comprise the second main section, one plays as a soldier who shoots enemies along his way. In level 5 the soldier must jump from rock to rock in a river, shooting hostile birds. Thereafter, the soldier makes his way into the enemy headquarters with the goal of retrieving secret documents.
Army Moves was regarded as a rather bad game on the Amiga — "Almost non-existent gameplay makes this very poor value for money", according to a review in Zzap!. However, it received mixed reviews from ZX Spectrum magazines and was successful enough in Spain to spawn two follow-ups, Navy Moves in 1988 and Arctic Moves in 1995. The latter appeared only for the PC platform, and it included the first two chapters of the series, playable through a ZX Spectrum emulator, as an extra. A fourth entry in the series, Desert Moves was announced at the end of the game Arctic Moves, but never appeared.
The game music in non-Spanish versions is based on the Colonel Bogey March.
References
External links
Game card in Amstrad ESP.
Game card in Computer Emuzone.
Review of Army Moves in Zzap!
Review of Army Moves in Your Sinclair
Amiga games
Amstrad CPC games
Atari ST games
Commodore 64 games
Dinamic Software games
DOS games
Europe-exclusive video games
Helicopter video games
MSX games
ZX Spec
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https://en.wikipedia.org/wiki/Phoropter
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A phoropter or refractor is an ophthalmic testing device. It is commonly used by eye care professionals during an eye examination, and contains different lenses used for refraction of the eye during sight testing, to measure an individual's refractive error and determine their eyeglass prescription.
It also is used to measure the patients' phorias and ductions, which are characteristics of binocularity.
Typically, the patient sits behind the phoropter, and looks through it at an eye chart placed at optical infinity (20 feet or 6 metres), then at near (16 inches or 40 centimetres) for individuals needing reading glasses. The eye care professional then changes lenses and other settings, while asking the patient for subjective feedback on which settings gave the best vision. The patient's habitual prescription or an automated refractor may be used to provide initial settings for the phoropter. Sometimes a retinoscope is used through the phoropter to measure the vision without the patient having to speak, which is useful for infants and people who do not speak the language of the practitioner.
Phoropters can also measure heterophorias (natural resting position of the eyes), accommodative amplitudes, accommodative leads/lags, accommodative posture, horizontal and vertical vergences, and more.
The major components of the phoropter are the battery of spherical and cylindrical lenses, auxiliary devices such as Maddox rods, filtered lenses, prisms, and the JCC (Jackson cross cylinder) used for astigmatism measurement. The prismatic lenses are used to analyze binocular vision and treat orthoptic problems.
From the measurements taken, the specialist will write an eyeglass prescription that contains at least three numerical specifications for each eye: sphere, cylinder, and axis, as well as pupillary distance (distance between eyes), and, rarely, prism for one or both eyes.
The lenses within a phoropter refract light in order to focus images on the patient's retina. The o
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https://en.wikipedia.org/wiki/Multiple%20Spanning%20Tree%20Protocol
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The Multiple Spanning Tree Protocol (MSTP) and algorithm, provides both simple and full connectivity assigned to any given virtual LAN (VLAN) throughout a bridged local area network. MSTP uses bridge protocol data unit (BPDUs) to exchange information between spanning-tree compatible devices, to prevent loops in each Multiple Spanning Tree instance (MSTI) and in the common and internal spanning tree (CIST), by selecting active and blocked paths. This is done as well as in Spanning Tree Protocol (STP) without the need of manually enabling backup links and getting rid of switching loop danger.
Moreover, MSTP allows frames/packets assigned to different VLANs to follow separate paths, each based on an independent MSTI, within MST regions composed of local area networks (LANs) and MST bridges. These regions and the other bridges and LANs are connected into a single common spanning tree (CST).
History and motivation
It was originally defined in IEEE 802.1s as an amendment to 802.1Q, 1998 edition and later merged into IEEE 802.1Q-2005 Standard, clearly defines an extension or an evolution of Radia Perlman's Spanning Tree Protocol (STP) and the Rapid Spanning Tree Protocol (RSTP). It has some similarities with Cisco Systems' Multiple Instances Spanning Tree Protocol (MISTP), but there are some differences.
The original STP and RSTP work on the physical link level, preventing bridge loops when redundant paths are present. However, when a LAN is virtualized using VLAN trunking, each physical link represents multiple logical connections. Blocking a physical link blocks all its logical links and forces all traffic through the remaining physical links within the spanning tree. Redundant links cannot be utilized at all. Moreover, without careful network design, seemingly redundant links on the physical level may be used to connect different VLANs and blocking any of them may disconnect one or more VLANs, causing bad paths.
Instead, MSTP provides a potentially better utiliza
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https://en.wikipedia.org/wiki/Pentadactyl
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Pentadactyl is a discontinued Firefox extension forked from the Vimperator and designed to provide a more efficient user interface for keyboard-fluent users. The design is heavily inspired by the Vim text editor, and the authors try to maintain consistency with it wherever possible.
Features
Once activated, Pentadactyl removes all Firefox's default user interface chrome (except for the tab bar) and adds a Vim-inspired command line at the bottom of the window. The key bindings and dialog invocation are also changed to those familiar to Vim users.
Apart from Vim-like features, Pentadactyl includes the Lynx-like links hinting mode, allowing user to enter links manipulation commands referring to the links by labels or numbers.
As the key mappings of the Pentadactyl differ significantly from those typically expected by web application developers, occasional conflicts of browser- and site-defined key mapping occur. Pentadactyl deals with such cases by providing a special "pass-through" mode, which passes all the key press events (except for Esc key) directly to the site. This mode can either be activated manually or enforced on a per domain basis with a configuration file.
Development
Pentadactyl was forked from the Vimperator Firefox extension after the disagreement over the project directions and governance. After the split Pentadactyl differentiated itself with improved start timing, ability to use the extension without restarting Firefox after installation and some changes for consistency with Vim.
The extension is available as stable releases and nightly builds.
As of November 2020, the project has been on hiatus since March 2017 due to developer inactivity and noncommunication, and doesn't seem to work on Firefox 57.0 (Firefox Quantum) or newer versions. The project was reported still working for Waterfox, Basilisk and Pale Moon browsers, but has since started to degrade due to no updates and will only work after applying community made patches. For the Pal
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https://en.wikipedia.org/wiki/Residuated%20lattice
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In abstract algebra, a residuated lattice is an algebraic structure that is simultaneously a lattice x ≤ y and a monoid x•y which admits operations x\z and z/y, loosely analogous to division or implication, when x•y is viewed as multiplication or conjunction, respectively. Called respectively right and left residuals, these operations coincide when the monoid is commutative. The general concept was introduced by Morgan Ward and Robert P. Dilworth in 1939. Examples, some of which existed prior to the general concept, include Boolean algebras, Heyting algebras, residuated Boolean algebras, relation algebras, and MV-algebras. Residuated semilattices omit the meet operation ∧, for example Kleene algebras and action algebras.
Definition
In mathematics, a residuated lattice is an algebraic structure such that
(i) (L, ≤) is a lattice.
(ii) is a monoid.
(iii) For all z there exists for every x a greatest y, and for every y a greatest x, such that x•y ≤ z (the residuation properties).
In (iii), the "greatest y", being a function of z and x, is denoted x\z and called the right residual of z by x. Think of it as what remains of z on the right after "dividing" z on the left by x. Dually, the "greatest x" is denoted z/y and called the left residual of z by y. An equivalent, more formal statement of (iii) that uses these operations to name these greatest values is
(iii)' for all x, y, z in L, y ≤ x\z ⇔ x•y ≤ z ⇔ x ≤ z/y.
As suggested by the notation, the residuals are a form of quotient. More precisely, for a given x in L, the unary operations x• and x\ are respectively the lower and upper adjoints of a Galois connection on L, and dually for the two functions •y and /y. By the same reasoning that applies to any Galois connection, we have yet another definition of the residuals, namely,
x•(x\y) ≤ y ≤ x\(x•y), and
(y/x)•x ≤ y ≤ (y•x)/x,
together with the requirement that x•y be monotone in x and y. (When axiomatized using (iii) or (iii)' monotonicity
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https://en.wikipedia.org/wiki/MV-algebra
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In abstract algebra, a branch of pure mathematics, an MV-algebra is an algebraic structure with a binary operation , a unary operation , and the constant , satisfying certain axioms. MV-algebras are the algebraic semantics of Łukasiewicz logic; the letters MV refer to the many-valued logic of Łukasiewicz. MV-algebras coincide with the class of bounded commutative BCK algebras.
Definitions
An MV-algebra is an algebraic structure consisting of
a non-empty set
a binary operation on
a unary operation on and
a constant denoting a fixed element of
which satisfies the following identities:
and
By virtue of the first three axioms, is a commutative monoid. Being defined by identities, MV-algebras form a variety of algebras. The variety of MV-algebras is a subvariety of the variety of BL-algebras and contains all Boolean algebras.
An MV-algebra can equivalently be defined (Hájek 1998) as a prelinear commutative bounded integral residuated lattice satisfying the additional identity
Examples of MV-algebras
A simple numerical example is with operations and In mathematical fuzzy logic, this MV-algebra is called the standard MV-algebra, as it forms the standard real-valued semantics of Łukasiewicz logic.
The trivial MV-algebra has the only element 0 and the operations defined in the only possible way, and
The two-element MV-algebra is actually the two-element Boolean algebra with coinciding with Boolean disjunction and with Boolean negation. In fact adding the axiom to the axioms defining an MV-algebra results in an axiomatization of Boolean algebras.
If instead the axiom added is , then the axioms define the MV3 algebra corresponding to the three-valued Łukasiewicz logic Ł3. Other finite linearly ordered MV-algebras are obtained by restricting the universe and operations of the standard MV-algebra to the set of equidistant real numbers between 0 and 1 (both included), that is, the set which is closed under the operations and of the st
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https://en.wikipedia.org/wiki/Tee%20%28command%29
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In computing, tee is a command in command-line interpreters (shells) using standard streams which reads standard input and writes it to both standard output and one or more files, effectively duplicating its input. It is primarily used in conjunction with pipes and filters. The command is named after the T-splitter used in plumbing.
Overview
The tee command is normally used to split the output of a program so that it can be both displayed and saved in a file. The command can be used to capture intermediate output before the data is altered by another command or program.
The tee command reads standard input, then writes its content to standard output. It simultaneously copies the data into the specified file(s) or variables.
The syntax differs depending on the command's implementation.
Implementations
The command is available for Unix and Unix-like operating systems, Microware OS-9, DOS (e.g. 4DOS, FreeDOS), Microsoft Windows (e.g. 4NT, Windows PowerShell), and ReactOS. The Linux tee command was written by Mike Parker, Richard Stallman, and David MacKenzie. The command is available as a separate package for Microsoft Windows as part of the UnxUtils collection of native Win32 ports of common GNU Unix-like utilities. The FreeDOS version was developed by Jim Hall and is licensed under the GPL.
The command has also been ported to the IBM i operating system.
Additionally the sponge command offers similar capabilities.
Unix and Unix-like
tee [ -a ] [ -i ] [ File ... ]
Arguments:
File ... A list of files, each of which receives the output.
Flags:
-a Appends the output to each file, rather than overwriting it.
-i Ignores interrupts.
The command returns the following exit values (exit status):
0 The standard input was successfully copied to all output files.
>0 An error occurred.
Using process substitution lets more than one process read the standard output of the originating process.
Read this example from GNU Coreutils, tee invocation.
Note: If a write to any suc
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https://en.wikipedia.org/wiki/Trendelenburg%27s%20sign
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Trendelenburg's sign is found in people with weak or paralyzed abductor muscles of the hip, namely gluteus medius and gluteus minimus. It is named after the German surgeon Friedrich Trendelenburg. It is often incorrectly referenced as the Trendelenburg test which is a test for vascular insufficiency in the lower extremities.
The Trendelenburg sign is said to be positive if, when standing on one leg (the 'stance leg'), the pelvis severely drops on the side opposite to the stance leg (the 'swing limb'). The muscle weakness is present on the side of the stance leg. If the patient compensates for this weakness (by tilting their trunk/thorax to the affected side), then the pelvis will be raised, rather than dropped, on the side opposite to the stance leg. Ergo, in the same situation, the patient's hip may be dropped or raised, dependent upon whether the patient is actively compensating, as above, or not. Compensation shifts the centre of gravity to the affected side, and also decreases the angle between the hip adductor muscles and femur, both of which decrease the forces needing to be applied by the hip adductor muscles to maintain relevant posture.
The gluteus medius is very important during the stance phase of the gait cycle to maintain both hips at the same level. Moreover, one leg stance accounts for about 60% of the gait cycle. Furthermore, during the stance phase of the gait cycle, there is approximately three times the body weight transmitted to the hip joint. The hip abductors' action accounts for two thirds of that body weight. A Trendelenburg sign can occur when there is presence of a muscular dysfunction (weakness of the gluteus medius or minimus) or when someone is experiencing pain.
See also
Gait abnormality
Superior gluteal nerve
Trendelenburg gait
References
External links
Trendelenburg Test at GPNotebook
Athletic training
Symptoms and signs: musculoskeletal system
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https://en.wikipedia.org/wiki/Java%20Card%20OpenPlatform
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Java Card OpenPlatform (JCOP) is a smart card operating system for the Java Card platform developed by IBM Zürich Research Laboratory.
On 31 January 2006 the development and support responsibilities transferred to the IBM Smart Card Technology team in Böblingen, Germany.
Since July 2007 support and development activities for the JCOP operating system on NXP / Philips silicon are serviced by NXP Semiconductors.
The title originates from the standards it complies with:
Java Card specifications
GlobalPlatform (formerly known as Visa Inc OpenPlatform) specifications
A Java Card JCOP has a Java Card Virtual Machine (JCVM) which allows it to run applications written in Java programming language.
History
First JC/OP Masks
Mask 0 : 1998 (spring)
First prototype on Atmel 8-bit uC – Flash memory, slow
Mask 1 : 1998
Siemens/Infineon SLE66 IC – Public key cryptography
Mask 2 and 3 : 1999
Gemplus International (now Gemalto) licensed JC/OP
Base mask for GemXpresso product line
Public key generation
Visa OpenPlatform
Mask 4 : 1999
Contactless JC/OP on Philips MifarePro chip
256 bytes RAM, 20 KB ROM and 8 KB EEPROM
Dual interface
JCOP01 and Cooperation with Philips
Mask 5 : 2000
Philips P8WE smartcard microcontroller
‘JCOP01’ is the foundation for all later versions
JCOP licensed by IBM
JCOP Tools for development
Visa breakthrough program
To counter MasterCard’s MULTOS
Cooperation between IBM (OS), Visa (OpenPlatform) and Philips (IC)
JCOP v1 owned by Visa
JCOP v2
Owned by IBM, sold by Philips
Philips SmartMX controller (SMX)
JCOP v2.2
GlobalPlatform 2.1.1
Java Card 2.2.1
Elliptic Curve Cryptography (ECC) F2M support
JCOP Tools Eclipse based
JCOP Transfer
JCOP v2.2.1 – JCOP v2.3.1
Owned by IBM, sold by Philips/NXP
Development transferred to IBM in Böblingen, Germany
USB interface
JCOP v2.3.2
JCOP technology owned by IBM
Policy change at IBM
Source code license acquired by NXP Semiconductors
To serve customer requests and projects
JCOP
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https://en.wikipedia.org/wiki/Systems%20Management%20Architecture%20for%20Server%20Hardware
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The Systems Management Architecture for Server Hardware (SMASH) is a suite of specifications that deliver industry standard protocols to increase productivity of the management of a data center.
Distributed Management Task Force developed SMASH Standard- which includes the Server Management Command Line Protocol specification - is a suite of specifications that deliver architectural semantics, industry standard protocols and profiles to unify the management of the data center. Through the development of conformance testing programs, the SMASH Forum will extend these capabilities by helping deliver additional compatibility in cross-platform servers.
External links
DMTF SMASH initiative
DMTF standards
Networking standards
System administration
Out-of-band management
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https://en.wikipedia.org/wiki/Pistol%20grip
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On a firearm or other tools, a pistol grip is a distinctly protruded handle underneath the main mechanism, to be held by the user's hand at a more vertical (and thus more ergonomic) angle, similar to how one would hold a conventional pistol.
In firearms, the pistol grip is located behind the trigger and generally held by the hand that operates the trigger. Rifles and shotguns without pistol grips are generally referred to as having "straight" or "upland" (shotguns only) style stocks. Some firearms, starting from a 1840s Belgian carbine, and most automatic weapons in the 20th century (e. g., Chauchat MG, Thompson submachine gun, AK-47 assault rifle), have a second frontal pistol grip (or foregrip) on the firearm's fore-end to be used by the support hand for better stability in operation.
Pistol grips can also serve multiple functions, such as a magazine housing (in semi-automatic pistols), bipod (in some foregrips) or tool storage device (for spare batteries, gun oil/cleaner, hex keys, etc.). In few firearms, like the Finnish Kk 62 light machine gun, the pistol grip is also used as a handle to charge the weapon.
Pistol grips are regarded as a defining feature in United States gun law. Pistol grips that protrude below the weapon but are not integrated with the shoulder stock (i.e. as part of a thumbhole stock) are currently regulated in some states and were regulated by the now-expired Federal Assault Weapons Ban.
Tools with pistol-style grips run the range from hand tools such as bar clamps and hand saws, to power tools such as electric drills and pneumatic surgical sternal saws. Often the word "gun" appears in the name of pistol gripped tools such as the glue gun, caulking gun and nail gun. Spray painters and grinders also often include this feature for added precision control.
One of the reasons that pistol-style grips are so common in machinery is because it is possible to ergonomically position the operating controls for use with minimal hand movement.
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https://en.wikipedia.org/wiki/Stochastic%20drift
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In probability theory, stochastic drift is the change of the average value of a stochastic (random) process. A related concept is the drift rate, which is the rate at which the average changes. For example, a process that counts the number of heads in a series of fair coin tosses has a drift rate of 1/2 per toss. This is in contrast to the random fluctuations about this average value. The stochastic mean of that coin-toss process is 1/2 and the drift rate of the stochastic mean is 0, assuming 1 = heads and 0 = tails.
Stochastic drifts in population studies
Longitudinal studies of secular events are frequently conceptualized as consisting of a trend component fitted by a polynomial, a cyclical component often fitted by an analysis based on autocorrelations or on a Fourier series, and a random component (stochastic drift) to be removed.
In the course of the time series analysis, identification of cyclical and stochastic drift components is often attempted by alternating autocorrelation analysis and differencing of the trend. Autocorrelation analysis helps to identify the correct phase of the fitted model while the successive differencing transforms the stochastic drift component into white noise.
Stochastic drift can also occur in population genetics where it is known as genetic drift. A finite population of randomly reproducing organisms would experience changes from generation to generation in the frequencies of the different genotypes. This may lead to the fixation of one of the genotypes, and even the emergence of a new species. In sufficiently small populations, drift can also neutralize the effect of deterministic natural selection on the population.
Stochastic drift in economics and finance
Time series variables in economics and finance — for example, stock prices, gross domestic product, etc. — generally evolve stochastically and frequently are non-stationary. They are typically modelled as either trend-stationary or difference stationary. A trend s
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https://en.wikipedia.org/wiki/Desktop%20Management%20Interface
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The Desktop Management Interface (DMI) generates a standard framework for managing and tracking components in a desktop, notebook or server computer, by abstracting these components from the software that manages them. The development of DMI, 2.0 version June 24, 1998, marked the first move by the Distributed Management Task Force (DMTF) into desktop-management standards.
Before the introduction of DMI, no standardized source of information could provide details about components in a personal computer.
Due to the rapid development of DMTF technologies, such as Common Information Model (CIM), the DMTF defined an "End of Life" process for DMI, which ended on March 31, 2005.
From 1999, Microsoft required OEMs and BIOS vendors to support the DMI interface/data-set in order to have Microsoft certification.
DMI and SMBIOS
DMI exposes system data (including the System Management BIOS (SMBIOS) data) to management software, but the two specifications function independently.
DMI is commonly confused with SMBIOS, which was actually called DMIBIOS in its first revisions.
Optional additional services: MIF data and MIF routines
When software queries a memory-resident agent that resides in the background, it responds by sending data in MIFs (Management Information Format) or activating MIF routines. Static data in a MIF would contain items such as model ID, serial number, memory- and port-addresses. A MIF routine could read memory and report its contents.
DMI and SNMP
DMI can co-exist with SNMP and other management protocols. For example, when an SNMP query arrives, DMI can fill out the SNMP MIB with data from its MIF. A single workstation or server can serve as a proxy agent that would contain the SNMP module and service an entire LAN segment of DMI-capable machines.
See also
dmidecode
Desktop management
lspci
System Management BIOS
Web-Based Enterprise Management (WBEM)
WS-Management
References
Further reading
External links
The DMI home page links to repositori
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https://en.wikipedia.org/wiki/E-Amusement
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e-Amusement, stylized as e-amusement, is an online service operated by Konami, used primarily for online functionality on its arcade video games. The system is used primarily to save progress and unlockable content between games, participate in internet high score lists, access other exclusive features depending on the game, and access the Paseli digital currency service.
The system uses online user accounts tied to a contactless smart card system called the "e-Amusement Pass". Users log into an e-Amusement enabled game by holding their pass up to the card reader and using a PIN.
The system is similar to parts of the functionality of the rival Taito NESYS and SEGA ALL.Net systems.
Cards
Magnetic cards
Prior to 2006, e-Amusement used magnetic stripe cards called Entry Passes that were sold separately for each game using the platform, either from an arcade desk or through a vending machine. Each card held data for one player, and typically came in 5 designs specific to the game (usually featuring character artwork). "Special" cards were also distributed from time to time, often alongside the console versions of certain games; these cards could sometimes be used to unlock special content in their respective game.
e-Amusement Pass
In 2006, Konami began to phase out the original magnetic card system in favor of the e-Amusement Pass; an IC contactless smartcard that works across all games that were upgraded to use the new system. The new cards also use a 4-digit PIN for security. In the event the pass is lost, its existing data can be transferred over to a new pass through Konami's website.
The pass can also be linked to a mobile phone "Konami NetDX" account, allowing players to access their scores and other data on their mobile phone. On some games, customization of the game can also be done through the NetDX system. However, only smartphones sold to Japan with FeliCa RFID support can use this function.
Beatmania IIDX
Beatmania IIDX is one of the prominent gam
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https://en.wikipedia.org/wiki/Speedy%20in%20Oz
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Speedy in Oz (1934) is the twenty-eighth in the series of Oz books created by L. Frank Baum and his successors, and the fourteenth written by Ruth Plumly Thompson. It was Illustrated by John R. Neill.
This book features yet another island which floats in the sky: Umbrella Island, which flies by virtue of a huge umbrella with lifting and shielding powers. The king is not very good at steering the flying island; he bumps it into a giant's head. For compensation, Loxo, the great brute, demands the King's daughter Gureeda, whom he mistakes for a boy, as a servant to lace his huge boots. However, he grants the Umbrella Islanders three months to train the child to be a bootlacer.
Meanwhile, the boy Speedy (from The Yellow Knight of Oz) returns for another adventure. While inspecting a dinosaur skeleton, Speedy is blown by a geyser into the air. The skeleton comes magically to life and becomes Terrybubble, a live dinosaur skeleton. Terrybubble and Speedy land on Umbrella Island. Speedy develops a friendship with Princess Gureeda. He also becomes friendly with the island's resident wizard, Waddy. An unscrupulous minister, however, notices that Speedy and Gureeda look very much alike and could pass for fraternal twins. He hatches a plot to compensate the giant by handing Speedy over to him as a slave instead of Gureeda. Terrybubble learns of this plot, and he parachutes off the island with Speedy and Gureeda. All three are captured by Loxo, and it is up to the wizard Waddy to save them.
Aside from a brief consultation with Princess Ozma and her advisers, the book deals exclusively with characters of Thompson's creation.
Copyright status
Under current United States copyright laws, Speedy in Oz is scheduled to enter the public domain on January 1, 2030. All of Thompson's subsequent Oz books for Reilly had their copyrights expire prematurely, thus this will be the last copyright in the series to lapse.
References
External links
On Speedy in Oz
Oz (franchise) b
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https://en.wikipedia.org/wiki/Snow%20algae
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Snow algae are a group of freshwater micro-algae which grow in the alpine and polar regions of the earth. These algae have been observed to come in a variety of colors associated with both the individual species, stage of life or topography/geography. A typical snow algae in the alps and polar regions is Chlamydomonas nivalis. This variation is associated with both albedo differences of the snowy habitat and the presence of micro-invertebrates. Snow algae play a critical role in the trophic organization as primary producers who in turn are consumed primarily by tardigrades and rotifers. Snow algae have also been found to travel great distances being carried by winds.
References
Algae
Aquatic ecology
Snow algae
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https://en.wikipedia.org/wiki/Trophic%20egg
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A trophic egg is an egg whose function is not reproduction but nutrition; in essence, the trophic egg serves as food for offspring hatched from viable eggs. In most species that produce them, a trophic egg is usually an unfertilised egg. The production of trophic eggs has been observed in a highly diverse range of species, including fish, amphibians, spiders and insects. The function is not limited to any particular level of parental care, but occurs in some sub-social species of insects, the spider A. ferox, and a few other species like the frogs Leptodactylus fallax and Oophaga, and the catfish Bagrus meridionalis.
Parents of some species deliver trophic eggs directly to their offspring, whereas some other species simply produce the trophic eggs after laying the viable eggs; they then leave the trophic eggs where the viable offspring are likely to find them.
The mackerel sharks present the most extreme example of proximity between reproductive eggs and trophic eggs; their viable offspring feed on trophic eggs in utero.
Despite the diversity of species and life strategies in which trophic eggs occur, all trophic egg functions are similarly derived from similar ancestral functions, which once amounted to the sacrifice of potential future offspring in order to provide food for the survival of rival (usually earlier) offspring. In more derived examples the trophic eggs are not viable, being neither fertilised, nor even fully formed in some cases, so they do not represent actually potential offspring, although they still represent parental investment corresponding to the amount of food it took to produce them.
Morphology
Trophic eggs are not always morphologically distinct from normal reproductive eggs; however if there is no physical distinction there tends to be some kind of specialised behaviour in the way that trophic eggs are delivered by the parents.
In some beetles, trophic eggs are paler in colour and softer in texture than reproductive eggs, with a smooth
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https://en.wikipedia.org/wiki/Polyhedron%20model
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A polyhedron model is a physical construction of a polyhedron, constructed from cardboard, plastic board, wood board or other panel material, or, less commonly, solid material.
Since there are 75 uniform polyhedra, including the five regular convex polyhedra, five polyhedral compounds, four Kepler-Poinsot polyhedra, and thirteen Archimedean solids, constructing or collecting polyhedron models has become a common mathematical recreation. Polyhedron models are found in mathematics classrooms much as globes in geography classrooms.
Polyhedron models are notable as three-dimensional proof-of-concepts of geometric theories. Some polyhedra also make great centerpieces, tree toppers, Holiday decorations, or symbols. The Merkaba religious symbol, for example, is a stellated octahedron. Constructing large models offer challenges in engineering structural design.
Construction
Construction begins by choosing a size of the model, either the length of its edges or the height of the model. The size will dictate the material, the adhesive for edges, the construction time and the method of construction.
The second decision involves colours. A single-colour cardboard model is easiest to construct — and some models can be made by folding a pattern, called a net, from a single sheet of cardboard. Choosing colours requires geometric understanding of the polyhedron. One way is to colour each face differently. A second way is to colour all square faces the same, all pentagonal faces the same, and so forth. A third way is to colour opposite faces the same. Many polyhedra are also coloured such that no same-coloured faces touch each other along an edge or at a vertex.
For example, a 20-face icosahedron can use twenty colours, one colour, ten colours, or five colours, respectively.
An alternative way for polyhedral compound models is to use a different colour for each polyhedron component.
Net templates are then made. One way is to copy templates from a polyhedron-making bo
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https://en.wikipedia.org/wiki/MESM
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MESM (Ukrainian: MEOM, Мала Електронна Обчислювальна Машина; Russian: МЭСМ, Малая Электронно-Счетная Машина; 'Small Electronic Calculating Machine') was the first universally programmable electronic computer in the Soviet Union. By some authors it was also depicted as the first one in continental Europe, even though the electromechanical computers Zuse Z4 and the Swedish BARK preceded it.
Overview
MESM was created by a team of scientists under the direction of Sergei Alekseyevich Lebedev from the Kiev Institute of Electrotechnology in the Ukrainian SSR, at Feofaniya (near Kyiv).
Initially, MESM was conceived as a layout or model of a Large Electronic Calculating Machine and letter "M" in the title meant "model" (prototype).
Work on the machine was research in nature, in order to experimentally test the principles of constructing universal digital computers. After the first successes and in order to meet the extensive governmental needs of computer technology, it was decided to complete the layout of a full-fledged machine capable of "solving real problems". MESM became operational in 1950. It had about 6,000 vacuum tubes and consumed 25 kW of power. It could perform approximately 3,000 operations per minute.
Creation and operation history
Principal computer architecture scheme was ready by the end of 1949. As well as a few schematic diagrams of an individual blocks.
In 1950 the computer was mounted in a two-story building of the former hostel of a convent in Feofania, where a psychiatric hospital was located before the second world war.
November 6, 1950: team performed the first test launch. Test task was:
January 4, 1951: First useful calculations performed. Calculate the factorial of a number, raise number in a power. Computer was shown to special commission of the USSR State Academy of Sciences. Team was led by Mstislav Keldysh.
December 25, 1951: Official government testing passed successfully. USSR Academy of Sciences and Mstislav Keldysh began regul
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https://en.wikipedia.org/wiki/ORTF%20stereo%20technique
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The ORTF stereo technique, also known as side-other-side, is a microphone technique used to record stereo sound.
It was devised around 1960 at the Office de Radiodiffusion Télévision Française
(ORTF), currently Radio France.
ORTF combines both the volume difference and the timing difference as sound arrives on- and off-axis at two cardioid microphones spread to a 110° angle, and spaced 17 cm apart.
The microphones should be as similar as possible, preferably a frequency-matched pair of an identical type and model.
The result is a realistic stereo field that has reasonable compatibility with mono playback. Since the cardioid polar pattern rejects off-axis sound, less of the ambient room characteristics are picked up. This means that the mics can be placed farther away from the sound sources, resulting in a blend that may be more appealing. Further, the availability of purpose-built microphone mounts makes ORTF easy to achieve.
As with all microphone arrangements, the spacing and angle can be manually adjusted slightly by ear for the best sound, which may vary depending on room acoustics, source characteristics, and other factors. But this arrangement is defined as it is because it was the result of considerable research and experimentation, and its results are predictable and repeatable.
These interchannel differences are not the same as interaural differences, as produced by artificial head recordings. Even the spacing of 17 cm is not strictly based on interaural ear spacing. The recording angle for this microphone system is ±48° = 96°.
See also
Jecklin Disk
NOS stereo technique
References
External links
Visualization ORTF Stereo Microphone System - Cardioid/Cardioid - 110° 17 cm Equivalence Stereo - SRA Recording angle
Microphone practices
Recording
Audio engineering
Stereophonic techniques
fr:Office de radiodiffusion télévision française
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https://en.wikipedia.org/wiki/Shore%20power
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Shore power or shore supply is the provision of shoreside electrical power to a ship at berth while its main and auxiliary engines are shut down. While the term denotes shore as opposed to off-shore, it is sometimes applied to aircraft or land-based vehicles (such as campers, heavy trucks with sleeping compartments and tour buses), which may plug into grid power when parked for idle reduction.
The source for land-based power may be grid power from an electric utility company, but also possibly an external remote generator. These generators may be powered by diesel or renewable energy sources such as wind or solar.
Shore power saves consumption of fuel that would otherwise be used to power vessels while in port, and eliminates the air pollution associated with consumption of that fuel. A port city may have anti-idling laws that require ships to use shore power. Use of shore power may facilitate maintenance of the ship's engines and generators, and reduces noise.
Oceangoing ships
"Cold ironing" is specifically a shipping industry term that came into use when all ships had coal-fired engines. When a ship tied up at port, there was no need to continue to feed the fire and the iron engines would cool down, eventually going completely cold – hence the term "cold ironing". Commercial ships can use shore-supplied power for services such as cargo handling, pumping, ventilation and lighting while in port, they need not run their own diesel engines, reducing air pollution emissions. Examples are ferries and cruise ships for hotel electric power, and a salmon feeder ship uses shore power while at the salmon farm.
Small craft
On small private boats, electrical power supply on board is usually provided by 12 or 24 volt DC batteries whilst at sea unless the vessel has a generator. When the vessel is berthed in a marina or harbourside, mains electricity is often offered via a shore power connection. This allows the vessel to use a battery charger to recharge batteries and also
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https://en.wikipedia.org/wiki/Overlapped%20I/O
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Overlapped I/O is a name used for asynchronous I/O in the Windows API. It was introduced as an extension to the API in Windows NT.
Utilizing overlapped I/O requires passing an OVERLAPPED structure to API functions that normally block, including ReadFile(), WriteFile(), and Winsock's WSASend() and WSARecv(). The requested operation is initiated by a function call which returns immediately, and is completed by the OS in the background. The caller may optionally specify a Win32 event handle to be raised when the operation completes. Alternatively, a program may receive notification of an event via an I/O completion port, which is the preferred method of receiving notification when used in symmetric multiprocessing environments or when handling I/O on a large number of files or sockets. The third and the last method to get the I/O completion notification with overlapped IO is to use ReadFileEx() and WriteFileEx(), which allow the User APC routine to be provided, which will be fired on the same thread on completion (User APC is the thing very similar to Unix/POSIX signal, with the main difference being that the signals are using signal numbers from the historically predefined enumeration, while the User APC can be any function declared as "void f(void* context)"). The so-called overlapped API presents some differences depending on the Windows version used.
Asynchronous I/O is particularly useful for sockets and pipes.
Unix and Linux implement the POSIX asynchronous I/O API (AIO).
References
External links
MSDN Reference: ReadFile()
MSDN Reference: WriteFile()
MSDN Reference: OVERLAPPED Data structure
I/O Completion Port
Concurrency control
Events (computing)
Input/output
Programming constructs
Microsoft application programming interfaces
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https://en.wikipedia.org/wiki/Sausage%20making
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The origins of meat preservation are lost to the ages but probably began when humans began to realize the preservative value of salt.
Sausage making originally developed as a means to preserve and transport meat. Primitive societies learned that dried berries and spices could be added to dried meat.
The procedure of stuffing meat into casings remains basically the same today, but sausage recipes have been greatly refined and sausage making has become a highly respected culinary art.
Sausages come in two main types: fresh and cured. Cured sausages may be either cooked or dried. Many cured sausages are smoked, but this is not mandatory. The curing process itself changes the meat and imparts its own flavors. An example is the difference in taste between a pork roast and a ham.
All smoked sausages are cured. The reason is the threat of botulism. The bacterium responsible, Clostridium botulinum, is ubiquitous in the environment, grows in the anaerobic conditions created in the interior of the sausage, and thrives in the to temperature range common in the smoke house and subsequent ambient storage. Thus, for safety reasons, sausages are cured before smoking.
Types of sausages and their storage
Fresh sausages
Fresh sausages are simply seasoned ground meats that are cooked before serving. Fresh sausages normally do not use cure (Prague powder #1) although cure can be used if desired. In addition fresh sausages typically do not use smoke flavors, although liquid smoke can be used. Fresh sausages are never smoked in a cold smoker because of the danger of botulism.
The primary seasoning agents in fresh sausages are salt and sugar along with various savory herbs and spices, and often vegetables, including onion and garlic.
A British fresh sausage typically contains around 10% butcher's rusk, 10% water, 2.5% seasoning, and 77.5% meat. At the point of sale, British sausages will often be labelled as "actual meat content X%". As meat can be fatty or lean, the X% is calcul
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https://en.wikipedia.org/wiki/Anamorphosis
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Anamorphosis is a distorted projection that requires the viewer to occupy a specific vantage point, use special devices, or both to view a recognizable image. It is used in painting, photography, sculpture and installation, toys, and film special effects. The word is derived from the Greek prefix ana-, meaning "back" or "again", and the word morphe, meaning "shape" or "form". Extreme anamorphosis has been used by artists to disguise caricatures, erotic and scatological scenes, and other furtive images from a casual spectator, while revealing an undistorted image to the knowledgeable viewer.
Types of projection
There are two main types of anamorphosis: perspective (oblique) and mirror (catoptric). More complex anamorphoses can be devised using distorted lenses, mirrors, or other optical transformations.
An oblique anamorphism forms an affine transformation of the subject. Early examples of perspectival anamorphosis date to the Renaissance of the fifteenth century and largely relate to religious themes.
With mirror anamorphosis, a conical or cylindrical mirror is placed on the distorted drawing or painting to reveal an undistorted image. The deformed picture relies on laws regarding angles of incidence of reflection. The length of the flat drawing's curves are reduced when viewed in a curved mirror, such that the distortions resolve into a recognizable picture. Unlike perspective anamorphosis, catoptric images can be viewed from many angles. The technique was originally developed in China during the Ming Dynasty, and the first European manual on mirror anamorphosis was published around 1630 by the mathematician Vaulezard.
Channel anamorphosis or tabula scalata has a different image on each side of a corrugated carrier. A straight frontal view shows an unclear mix of the images, while each image can be viewed correctly from a certain angle.
History
Prehistory
The Stone Age cave paintings at Lascaux may make use of anamorphic technique, because the oblique angle
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https://en.wikipedia.org/wiki/Peer%20Name%20Resolution%20Protocol
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Peer Name Resolution Protocol (PNRP) is a peer-to-peer protocol designed by Microsoft. PNRP enables dynamic name publication and resolution, and requires IPv6.
PNRP was first mentioned during a presentation at a P2P conference in November 2001. It appeared in July 2003 in the Advanced Networking Pack for Windows XP, and was later included in the Service Pack 2 for Windows XP. PNRP 2.0 was introduced with Windows Vista and was available for download for Windows XP Service Pack 2 users. PNRP 2.1 is included in Windows Vista SP1, Windows Server 2008 and Windows XP SP3. PNRP v2 is not available for Windows XP Professional x64 Edition or any edition of Windows Server 2003.
Windows Remote Assistance in Windows 7 uses PNRP, Teredo and IPv6 when connecting using the Easy Connect option.
The design of PNRP is covered by US Patent #7,065,587, issued on June 20, 2006.
Support for PNRP was removed in Windows 10 with version 1909.
PNRP services
The PNRP is a distributed name resolution protocol allowing Internet hosts to publish "peer names" and corresponding IPv6 addresses and optionally other information. Other hosts can then resolve the peer name, retrieve the corresponding addresses and other information, and establish peer-to-peer connections.
With PNRP, peer names are composed of an "authority" and a "qualifier". The authority is identified by a secure hash of an associated public key, or by a place-holder (the number zero) if the peer name is "unsecured". The qualifier is a string, allowing an authority to have different peer names for different services.
If a peer name is secure, the PNRP name records are signed by the publishing authority, and can be verified using its public key. Unsecured peer names can be published by anybody, without possible verification.
Multiple entities can publish the same peer name. For example, if a peer name is associated with a group, any group member can publish addresses for the peer name.
Peer names are published and resolve
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https://en.wikipedia.org/wiki/Nomad%20software
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NOMAD is a relational database and fourth-generation language (4GL), originally developed in the 1970s by time-sharing vendor National CSS. While it is still in use today, its widest use was in the 1970s and 1980s. NOMAD supports both the relational and hierarchical database models.
NOMAD provides both interactive and batch environments for data management and application development, including commands for database definition, data manipulation, and reporting. All components are accessible by and integrated through a database-oriented programming language. Unlike many tools for managing mainframe data, which are geared to the needs of professional programmers in MIS departments, NOMAD is particularly designed for (and sold to) application end-users in large corporations. End-users employ Nomad in batch production cycles and in Web-enabled applications, as well as for reporting and distribution via the web or PC desktop.
Capabilities
NOMAD is distinguished by five characteristics:
An intuitive database-oriented fourth-generation programming language (4GL) for creating databases, managing data, and writing applications
An interactive environment in which any 4GL statement may be typed and immediately processed (comparable to interactive tools like PHP or Perl)
Relational database features, supporting lookup tables and the other elements of a normalized relational database
Powerful set-at-a-time operations under the control of simple imperative commands
Accesses data from many sources, such as VSAM, IMS, IDMS, DB2, Oracle, and SQL Server.
NOMAD's language was designed to simplify the application development process, especially for reporting applications. Where possible, common requirements were addressed by intuitive nonprocedural syntax elements, to avoid traditional programming. The heart of the system was the LIST command, which created report output.
LIST BY STATE BY CUST_ID NAME PHONE ACROSS STATUS BALANCE WHERE STATE AMONG('CT','NY')
State Customer ID Nam
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https://en.wikipedia.org/wiki/Endoreduplication
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Endoreduplication (also referred to as endoreplication or endocycling) is replication of the nuclear genome in the absence of mitosis, which leads to elevated nuclear gene content and polyploidy. Endoreplication can be understood simply as a variant form of the mitotic cell cycle (G1-S-G2-M) in which mitosis is circumvented entirely, due to modulation of cyclin-dependent kinase (CDK) activity. Examples of endoreplication characterized in arthropod, mammalian, and plant species suggest that it is a universal developmental mechanism responsible for the differentiation and morphogenesis of cell types that fulfill an array of biological functions. While endoreplication is often limited to specific cell types in animals, it is considerably more widespread in plants, such that polyploidy can be detected in the majority of plant tissues.
Examples in nature
Endoreplicating cell types that have been studied extensively in model organisms
Endoreplication, endomitosis and polytenization
Endoreplication, endomitosis and polytenization are three somewhat different processes resulting in polyploidization of a cell in a regulated manner. In endoreplication cells skip M phase completely, resulting in a mononucleated polyploid cell. Endomitosis is a type of cell cycle variation where mitosis is initiated, but some of the processes are not completed. Depending on how far the cell progresses through mitosis, this will give rise to a mononucleated or binucleated polyploid cell. Polytenization arises with under- or overamplification of some genomic regions, creating polytene chromosomes.
Biological significance
Based on the wide array of cell types in which endoreplication occurs, a variety of hypotheses have been generated to explain the functional importance of this phenomenon. Unfortunately, experimental evidence to support these conclusions is somewhat limited:
Cell/organism size
Cell ploidy often correlates with cell size, and in some instances, disruption of endoreplication
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https://en.wikipedia.org/wiki/Lightweight%20Imaging%20Device%20Interface%20Language
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Lightweight Imaging Device Interface Language (abbr. LIDIL) is a printer interface definition language used in more recent Hewlett-Packard printers.
This language is commonly used on HP Deskjets that do not support the PCL printer language. As the name suggests, the language only supports the definition of raster documents, and is very limited overall. It is a "host-based" protocol which is advertised with LDL in the CMD: (command set) field of the device ID string. Such models do not support printing ASCII text.
External links
Host-based printing (including LIDIL)
Page description languages
Specification languages
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https://en.wikipedia.org/wiki/Memory-disk%20synchronization
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Memory-disk synchronisation is a process used in computers that immediately writes to disk any data queued for writing in volatile memory. Data is often held in this way for efficiency's sake, since writing to disk is a much slower process than writing to RAM. Disk synchronization is needed when the computer is going to be shut down, or occasionally if a particularly important bit of data has just been written.
In Unix-like systems, a disk synchronization may be requested by any user with the sync command.
See also
mmap, a POSIX-compliant Unix system call that maps files or devices into memory
msync, a POSIX-compliant Unix system call that forcefully flush memory to disk and synchronize
Computer memory
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https://en.wikipedia.org/wiki/WBSF
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WBSF (channel 46), branded on-air as CW 46, is a television station licensed to Bay City, Michigan, United States, serving northeastern Michigan as an affiliate of The CW. It is owned by Cunningham Broadcasting, which maintains a shared services agreement (SSA) with Sinclair Broadcast Group, owner of Flint-licensed Fox affiliate WSMH (channel 66), for the provision of certain services. Sinclair also operates Saginaw-licensed NBC affiliate WEYI-TV (channel 25) under a separate SSA with owner Howard Stirk Holdings.
The three stations share studios on West Pierson Road in Mount Morris Township (with a Flint mailing address); WBSF's transmitter is located at its former studios on West Willard Road in Vienna Township along the Genesee–Saginaw county line (with a Clio mailing address).
History
A permit was issued by the FCC for a new station on channel 46 in Bay City to Vista Communications Group in late 2003. The station was expected to be the WB network affiliate for the Flint/Tri-Cities market.
On October 1, 2004, the station's construction permit was approved. In that same year, Barrington launched WBSF on cable and on WEYI's second digital subchannel, bringing The WB back to the market after a three-year absence (WB programming in-market was last seen on WEYI on a secondary clearance from 1999 to 2001). On February 2, 2005, the FCC transferred the permit to Acme Television then to Barrington Broadcasting.
With the merger of The WB and UPN to become The CW, WBSF became the area's network affiliate in September 2006 when the channel began broadcasting over the air. Because of this, a chance existed that WKBD (which along with WBKP are the only other over-the-air CW affiliates in Michigan) would be dropped from this market's cable systems as both WBSF and WKBD would be CW affiliates. However, in the case of Midland, two CBS affiliates do coexist on the same cable system. This occurred on Charter's Tri-Cities systems which replaced WKBD with MyNetworkTV affiliate WNE
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https://en.wikipedia.org/wiki/Restriction%20site
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Restriction sites, or restriction recognition sites, are located on a DNA molecule containing specific (4-8 base pairs in length) sequences of nucleotides, which are recognized by restriction enzymes. These are generally palindromic sequences (because restriction enzymes usually bind as homodimers), and a particular restriction enzyme may cut the sequence between two nucleotides within its recognition site, or somewhere nearby.
Function
For example, the common restriction enzyme EcoRI recognizes the palindromic sequence GAATTC and cuts between the G and the A on both the top and bottom strands. This leaves an overhang (an end-portion of a DNA strand with no attached complement) known as a sticky end on each end of AATT. The overhang can then be used to ligate in (see DNA ligase) a piece of DNA with a complementary overhang (another EcoRI-cut piece, for example).
Some restriction enzymes cut DNA at a restriction site in a manner which leaves no overhang, called a blunt end. Blunt ends are much less likely to be ligated by a DNA ligase because the blunt end doesn't have the overhanging base pair that the enzyme can recognize and match with a complementary pair. Sticky ends of DNA however are more likely to successfully bind with the help of a DNA ligase because of the exposed and unpaired nucleotides. For example, a sticky end trailing with AATTG is more likely to bind with a ligase than a blunt end where both the 5' and 3' DNA strands are paired. In the case of the example the AATTG would have a complementary pair of TTAAC which would reduce the functionality of the DNA ligase enzyme.
Applications
Restriction sites can be used for multiple applications in molecular biology such as identifying restriction fragment length polymorphisms (RFLPs).
Databases
Several databases exist for restriction sites and enzymes, of which the largest noncommercial database is REBASE. Recently, it has been shown that statistically significant nullomers (i.e. short absent motifs wh
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https://en.wikipedia.org/wiki/Mike%20and%20the%20Mad%20Dog
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Mike and the Mad Dog was an American sports radio show hosted by Mike Francesa and Christopher "Mad Dog" Russo that aired in afternoons on WFAN in New York City from September 1989 to August 2008. From 2002 the show was simulcast on television on the YES Network. On the radio, the show was simulcast beginning 2007 on WQYK in Tampa, Florida, and from 2004 until 2007 on WROW in Albany, New York.
History
Before Mike and the Mad Dog
Before Francesa and Russo were paired, Russo was an overnight/weekend and fill-in host. He caught the attention of Don Imus, who was impressed with his vibrant personality and brought Russo onto the Imus in the Morning show as its sports reporter.
Meanwhile, Francesa was a midday and weekend host at WFAN, and was known to be knowledgeable but somewhat dry on-air. Like Russo, Francesa got the attention of Imus when he made an on-the-air bet with Francesa that Seton Hall University's basketball team would not make the Final Four in the NCAA tournament. Imus promised Francesa a new Porsche if Seton Hall made the Final Four, which they did. Though Imus found a way around the bet, the dialogue between the two is considered to be among the classic moments in the history of Imus in the Morning.
Paired together
In August 1989, WFAN (which was owned at the time by Emmis Communications) was looking for hosts to replace the controversial Pete Franklin in the afternoon drive time period. Mark Mason, then the program director, floated the idea of teaming Francesa with Russo. At first, the station management thought the idea was crazy because they were no-names at that time. However, because of Francesa and Russo's popularity on the weekends and on Imus in the Morning individually, the station management decided to pair the two together. The show was dubbed Mike and the Mad Dog and debuted on September 5, 1989. However, the decision to pair them on an afternoon show was a surprise to the two men, and a risk. Things were rocky at first. Accordi
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https://en.wikipedia.org/wiki/Full%20Domain%20Hash
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In cryptography, the Full Domain Hash (FDH) is an RSA-based signature scheme that follows the hash-and-sign paradigm. It is provably secure (i.e., is existentially unforgeable under adaptive chosen-message attacks) in the random oracle model. FDH involves hashing a message using a function whose image size equals the size of the RSA modulus, and then raising the result to the secret RSA exponent.
Exact security of full domain hash
In the random oracle model, if RSA is -secure, then the full domain hash RSA signature scheme is -secure where,
.
For large this reduces to .
This means that if there exists an algorithm that can forge a new FDH signature that runs in time t, computes at most hashes, asks for at most signatures and succeeds with probability , then there must also exist an algorithm that breaks RSA with probability in time .
References
Jean-Sébastien Coron(AF): On the Exact Security of Full Domain Hash. CRYPTO 2000: pp. 229–235 (PDF)
Mihir Bellare, Phillip Rogaway: The Exact Security of Digital Signatures - How to Sign with RSA and Rabin. EUROCRYPT 1996: pp. 399–416 (PDF)
Digital signature schemes
Theory of cryptography
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https://en.wikipedia.org/wiki/AMD%2010h
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The AMD Family 10h, or K10, is a microprocessor microarchitecture by AMD based on the K8 microarchitecture. The first third-generation Opteron products for servers were launched on September 10, 2007, with the Phenom processors for desktops following and launching on November 11, 2007 as the immediate successors to the K8 series of processors (Athlon 64, Opteron, 64-bit Sempron).
Nomenclature
It appears that AMD has not used K-nomenclature (which originally stood for "Kryptonite" in the K5 processor) from the time after the use of the codename K8 for the AMD K8 or Athlon 64 processor family, since no K-nomenclature naming convention beyond K8 has appeared in official AMD documents and press releases after the beginning of 2005.
The name "K8L" was first coined by Charlie Demerjian in 2005, at the time a writer at The Inquirer, and was used by the wider IT community as a convenient shorthand while according to AMD official documents, the processor family was termed "AMD Next Generation Processor Technology".
The microarchitecture has also been referred to as Stars, as the codenames for desktop line of processors was named under stars or constellations (the initial Phenom models being codenamed Agena and Toliman).
In a video interview, Giuseppe Amato confirmed that the codename is K10.
It was revealed, by The Inquirer itself, that the codename "K8L" referred to a low-power version of the K8 family, later named Turion 64, and that K10 was the official codename for the microarchitecture.
AMD refers to it as Family 10h Processors, as it is the successor of the Family 0Fh Processors (codename K8). 10h and 0Fh refer to the main result of the CPUID x86 processor instruction. In hexadecimal numbering, 0Fh (h represents hexadecimal numbering) equals the decimal number 15, and 10h equals decimal 16. (The "K10h" form that sometimes pops up is an improper hybrid of the "K" code and Family identifier number.)
Schedule of launch and delivery
Timeline
Historical information
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https://en.wikipedia.org/wiki/Hosted%20service%20provider
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A hosted service provider (xSP) is a business that delivers a combination of traditional IT functions such as infrastructure, applications (software as a service), security, monitoring, storage, web development, website hosting and email, over the Internet or other wide area networks (WAN). An xSP combines the abilities of an application service provider (ASP) and an Internet service provider (ISP).
This approach enables customers to consolidate and outsource much of their IT needs for a predictable recurring fee. xSPs that integrate web publishing give customers a central repository to rapidly and efficiently distribute information and resources among employees, customers, partners and the general public.
Hosted Service Providers benefit from economies of scale and operate on a one-to-many business model, delivering the same software and services to many customers at once. Customers are charged on a subscription basis.
Services offered
As defined by analyst Ovum.
Repeatable business process-led services shared among several clients
Remotely delivered application services using shared resources
Infrastructure services (both remotely managed and/or hosted services spanning data centre services, managed servers and databases, performance monitoring, security services, storage services and business continuity)
Web hosting- the provision of infrastructure and application services to support the hosting of Web sites.
History
Hard Corps, Inc., formed in December 1999 claimed the moniker 'xSP' and began using it in commerce prior to others.
See also
Web servers
Managed services
References
Internet access
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https://en.wikipedia.org/wiki/Tetraphobia
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Tetraphobia () is the practice of avoiding instances of the digit . It is a superstition most common in East Asian nations. It represents or can be translated as death or to die.
Rationale
The Chinese word for "four" (, pinyin: sì, jyutping: sei3), sounds quite similar to the word for "death" (, pinyin: sǐ, jyutping: sei2), in many varieties of Chinese. Similarly, the Sino-Japanese, Sino-Korean and Sino-Vietnamese words for "four", shi (し, Japanese) and sa (사, Korean), sound similar or identical to "death" in each language (see Korean numerals, Japanese numerals, Vietnamese numerals). Tetraphobia is known to occur in Korea and Japan since the two words sound identical, but not at all in Vietnam because they carry different tones (in the case of the word for "four", whether it is the Sino-Vietnamese reading tứ or the more common non-Sino-Vietnamese reading tư, neither sounds like the word for "death" which is tử) and Vietnamese does not use Sino-Vietnamese numerals as often in the first place.
Tetraphobia far surpasses triskaidekaphobia (Western superstitions around the number 13). It even permeates the business world in these regions of Asia.
Cultural examples by regions
In Mainland China
Chinese is a tonal language with a comparatively small inventory of permitted syllables, resulting in an exceptionally large number of homophone words. Many of the numbers are homophones or near-homophones of other words and have therefore acquired superstitious meanings.
The Chinese avoid phone numbers and addresses with fours because the pronunciation in "four" and "death" differ only in tone, especially when a combination with another number sounds similar to undesirable expressions. Example: “94” could be interpreted as being dead for a long time.
The People's Republic of China makes free use of the number 4 in many military designations for People's Liberation Army equipment, with examples including the Dongfeng-4 ICBM, Type 094 submarine, and Type 054A frigate, althou
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https://en.wikipedia.org/wiki/Field%20recording
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Field recording is the term used for an audio recording produced outside a recording studio, and the term applies to recordings of both natural and human-produced sounds. It also applies to sound recordings like electromagnetic fields or vibrations using different microphones like a passive magnetic antenna for electromagnetic recordings or contact microphones. For underwater field recordings, a field recordist uses hydrophones to capture the sounds and/or movements of whales, or other aquatic organisms. These recordings are very useful for sound designers.
Field recording of natural sounds, also called phonography (a term chosen to illustrate its similarities to photography), was originally developed as a documentary adjunct to research work in the field, and foley work for film. With the introduction of high-quality, portable recording equipment, it has subsequently become an evocative artform in itself. In the 1970s, both processed and natural phonographic recordings, (pioneered by Irv Teibel's Environments series), became popular.
"Field recordings" may also refer to simple monaural or stereo recordings taken of musicians in familiar and casual surroundings, such as the ethnomusicology recordings pioneered by John Lomax, Nonesuch Records, and Vanguard Records.
Techniques
General
Field recording often involves the capture of ambient noises that are low level and complex, and, in response, the requirements from the field recordist have often pushed the technical limits of recording equipment, that is, demanding low noise and extended frequency response in a portable, battery-powered unit. For this reason, field recordists have favoured high-quality (usually professional) recorders, microphones, and microphone pre-amplifiers. The history of the equipment used in this area closely tracks the development of professional portable audio recording technology. Modern accessories used in the field include, but are not limited to: windscreens (foam, fur, hair, parab
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https://en.wikipedia.org/wiki/Motorola%20Solutions
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Motorola Solutions, Inc. is an American video equipment, telecommunications equipment, software, systems and services provider that succeeded Motorola, Inc., following the spinoff of the mobile phone division into Motorola Mobility in 2011. The company is headquartered in Chicago, Illinois.
History
Motorola Solutions began trading as a separate independent company on January 4, 2011, under the NYSE symbol MSI. In April 2011, Motorola Solutions completed the sale of its cellular infrastructure business to Nokia Siemens Networks for $975 million in cash. As part of the transaction, approximately 6,900 employees were transferred to Nokia Siemens Networks. The same month, Chinese telecommunications company Huawei and Motorola Solutions settled their intellectual property disputes.
In 2012, Motorola Solutions purchased Psion for $200 million and added it to its Enterprise business. A large majority of the Enterprise business was formerly Symbol Technologies, which Motorola, Inc. had acquired in 2007. On October 27, 2014, Motorola Solutions sold its Enterprise business to Zebra Technologies for $3.45 billion in cash. As part of the sale, approximately 4,500 Motorola Solutions employees from locations throughout the world were transferred to Zebra.
In August 2015, the company received a $1 billion investment from the private equity firm Silver Lake Partners, enabling a stock buyback and providing Silver Lake with two board seats.
In December 2015, the company announced that it would acquire Airwave Solutions, the UK-based operator of the British public safety radio network servicing the police, fire, and ambulance services across England, Scotland, and Wales. The company completed the acquisition on February 19, 2016.
Beginning in March 2017, Motorola Solutions filed a series of lawsuits against China-based two-way radio manufacturer Hytera in the United States, Germany, and Australia, as well as with the United States International Trade Commission (USITC). The comp
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https://en.wikipedia.org/wiki/Bispectrum
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In mathematics, in the area of statistical analysis, the bispectrum is a statistic used to search for nonlinear interactions.
Definitions
The Fourier transform of the second-order cumulant, i.e., the autocorrelation function, is the traditional power spectrum.
The Fourier transform of C3(t1, t2) (third-order cumulant-generating function) is called the bispectrum or bispectral density.
Calculation
Applying the convolution theorem allows fast calculation of the bispectrum: , where denotes the Fourier transform of the signal, and its conjugate.
Applications
Bispectrum and bicoherence may be applied to the case of non-linear interactions of a continuous spectrum of propagating waves in one dimension.
Bispectral measurements have been carried out for EEG signals monitoring. It was also shown that bispectra characterize differences between families of musical instruments.
In seismology, signals rarely have adequate duration for making sensible bispectral estimates from time averages.
Bispectral analysis describes observations made at two wavelengths. It is often used by scientists to analyze elemental makeup of a planetary atmosphere by analyzing the amount of light reflected and received through various color filters. By combining and removing two filters, much can be gleaned from only two filters. Through modern computerized interpolation, a third virtual filter can be created to recreate true color photographs that, while not particularly useful for scientific analysis, are popular for public display in textbooks and fund raising campaigns.
Bispectral analysis can also be used to analyze interactions between wave patterns and tides on Earth.
A form of bispectral analysis called the bispectral index is applied to EEG waveforms to monitor depth of anesthesia.
Biphase (phase of polyspectrum) can be used for detection of phase couplings, noise reduction of polharmonic (particularly, speech ) signal analysis.
A physical interpretation
The bispectrum reflec
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https://en.wikipedia.org/wiki/DG/UX
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DG/UX is a discontinued Unix operating system developed by Data General for its Eclipse MV minicomputer line, and later the AViiON workstation and server line (both Motorola 88000 and Intel IA-32-based variants).
Overview
DG/UX 1.00, released in March, 1985, was based on UNIX System V Release 2 with additions from 4.1BSD. By 1987, DG/UX 3.10 had been released, with 4.2BSD TCP/IP networking, NFS and the X Window System included. DG/UX 4.00, in 1988, was a comprehensive re-design of the system, based on System V Release 3, and supporting symmetric multiprocessing on the Eclipse MV. The 4.00 filesystem was based on the AOS/VS II filesystem and, using the logical disk facility, could span multiple disks. DG/UX 5.4, released around 1991, replaced the legacy Unix file buffer cache with unified, demand paged virtual memory management. Later versions were based on System V Release 4.
On the AViiON, DG/UX supported multiprocessor machines at a time when most variants of Unix did not. The operating system was also more complete than some other Unix variants; for example, the operating system included a full C compiler (gcc) and also a logical volume manager. The OS was small and compact, but rich in features. It was simple and easy to install and did not require vast resources of memory or processing power. For example, a six-way Pentium Pro-based AViiON would support several hundred users using text terminals.
The volume manager built into the OS was simple, but very powerful. All disk administration could be performed online, without taking any file system offline. This included extending, relocating, mirroring or shrinking. The same functions could be performed on the swap area, allowing in-place migrations of disk storage without downtime. DG/UX 5.4 supported filesystem shrinking, "split mirror" online backup, filesystems up to 2 TB, and filesystem journaling in 1991. Few vendors offered similar features at that time.
DG/UX had a high-performance and stable clustered
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https://en.wikipedia.org/wiki/Systems%20architect
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The systems architect is an information and communications technology professional. Systems architects define the architecture of a computerized system (i.e., a system composed of software and hardware) in order to fulfill certain requirements. Such definitions include: a breakdown of the system into components, the component interactions and interfaces (including with the environment, especially the user), and the technologies and resources to be used in its design and implementation.
The systems architect's work should seek to avoid implementation issues and readily permit unanticipated extensions/modifications in future stages. Because of the extensive experience required for this, the systems architect is typically a very senior technologist with substantial, but general, knowledge of hardware, software, and similar (user) systems. Above all, the systems architect must be reasonably knowledgeable of the users' domain of experience. For example, the architect of an air traffic system needs to be more than superficially familiar with all of the tasks of an air traffic system, including those of all levels of users.
The title of systems architect connotes higher-level design responsibilities than a software engineer or programmer, though day-to-day activities may overlap.
Overview
Systems architects interface with multiple stakeholders in an organization in order to understand the various levels of requirements, the domain, the viable technologies, and anticipated development process. Their work includes determining multiple design and implementation alternatives, assessing such alternatives based on all identified constraints (such as cost, schedule, space, power, safety, usability, reliability, maintainability, availability, and other "ilities"), and selecting the most suitable options for further design. The output of such work sets the core properties of the system and those that are hardest to change later.
In small systems the architecture is typically
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https://en.wikipedia.org/wiki/Point%20plotting
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Point plotting is an elementary mathematical skill required in analytic geometry. Invented by René Descartes and originally used to locate positions on military maps, this skill is now assumed of everyone who wants to locate grid 7A on any map.
Using point plotting, one associates an ordered pair of real numbers (x, y) with a point in the plane in a one-to-one manner. As a result, one obtains the 2-dimensional Cartesian coordinate system.
To be able to plot points, one needs to first decide on a point in plane which will be called the origin, and a couple of perpendicular lines, called the x and y axes, as well as a preferred direction on each of the lines. Usually one chooses the x axis pointing right and the y axis pointing up, and these will be named the positive directions. Also, one picks a segment in the plane which is declared to be of unit length. Using rotated versions of this segment, one can measure distances along the x and y axes.
Having the origin and the axes in place, given a pair (x, y) of real numbers, one considers the point on the x axis at distance |x| from the origin and along the positive direction if x≥0, and the other direction otherwise. In the same way one picks the point on the y axis corresponding to the number y. The line parallel to the y axis going through the first point and the line parallel to the x axis going through the second point will intersect at precisely one point, which will be called the point with coordinates (x, y).
See also
Cartesian coordinate system
Graph of a function
Elementary mathematics
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https://en.wikipedia.org/wiki/26-bit%20computing
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In computer architecture, 26-bit integers, memory addresses, or other data units are those that are 26 bits wide, and thus can represent unsigned values up to 67,108,863. Two examples of computer processors that featured 26-bit memory addressing are certain second generation IBM System/370 mainframe computer models introduced in 1981 (and several subsequent models), which had 26-bit physical addresses but had only the same 24-bit virtual addresses as earlier models, and the first generations of ARM processors.
History
IBM System/370
As data processing needs continued to grow, IBM and their customers faced challenges directly addressing larger memory sizes. In what ended up being a short-term "emergency" solution, a pair of IBM's second wave of System/370 models, the 3033 and 3081, introduced 26-bit real memory addressing, increasing the System/370's amount of physical memory that could be attached by a factor of 4 from the previous 24-bit limit of 16 MB. IBM referred to 26-bit addressing as "extended real addressing," and some subsequent models also included 26-bit support. However, only 2 years later, IBM introduced 31-bit memory addressing, expanding both physical and virtual addresses to 31 bits, with its System/370-XA models, and even the popular 3081 was upgradeable to XA standard.
Given 26-bit's brief history as the state-of-the-art in memory addressing available in IBM's model range, and given that virtual addresses were still limited to 24 bits, software exploitation of 26-bit mode was limited. The few customers that exploited 26-bit mode eventually adjusted their applications to support 31-bit addressing, and IBM dropped support for 26-bit mode after several years producing models supporting 24-bit, 26-bit, and 31-bit modes. The 26-bit mode is the only addressing mode that IBM removed from its line of mainframe computers descended from the System/360. All the other addressing modes, including now 64-bit mode, are supported in current model mainframes.
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https://en.wikipedia.org/wiki/Alternating%20algebra
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In mathematics, an alternating algebra is a -graded algebra for which for all nonzero homogeneous elements and (i.e. it is an anticommutative algebra) and has the further property that for every homogeneous element of odd degree.
Examples
The differential forms on a differentiable manifold form an alternating algebra.
The exterior algebra is an alternating algebra.
The cohomology ring of a topological space is an alternating algebra.
Properties
The algebra formed as the direct sum of the homogeneous subspaces of even degree of an anticommutative algebra is a subalgebra contained in the centre of , and is thus commutative.
An anticommutative algebra over a (commutative) base ring in which 2 is not a zero divisor is alternating.
See also
Alternating multilinear map
Exterior algebra
Graded-symmetric algebra
References
Algebraic geometry
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https://en.wikipedia.org/wiki/List%20of%20logic%20symbols
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In logic, a set of symbols is commonly used to express logical representation. The following table lists many common symbols, together with their name, how they should be read out loud, and the related field of mathematics. Additionally, the subsequent columns contains an informal explanation, a short example, the Unicode location, the name for use in HTML documents, and the LaTeX symbol.
Basic logic symbols
Advanced and rarely used logical symbols
These symbols are sorted by their Unicode value:
Usage in various countries
Poland
in Poland, the universal quantifier is sometimes written ∧, and the existential quantifier as ∨. The same applies for Germany.
Japan
The ⇒ symbol is often used in text to mean "result" or "conclusion", as in "We examined whether to sell the product ⇒ We will not sell it". Also, the → symbol is often used to denote "changed to", as in the sentence "The interest rate changed. March 20% → April 21%".
See also
Józef Maria Bocheński
List of notation used in Principia Mathematica
List of mathematical symbols
Logic alphabet, a suggested set of logical symbols
Logical connective
Mathematical operators and symbols in Unicode
Non-logical symbol
Polish notation
Truth function
Truth table
Wikipedia:WikiProject Logic/Standards for notation
References
Further reading
Józef Maria Bocheński (1959), A Précis of Mathematical Logic, trans., Otto Bird, from the French and German editions, Dordrecht, South Holland: D. Reidel.
External links
Named character entities in HTML 4.0
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https://en.wikipedia.org/wiki/Supermatrix
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In mathematics and theoretical physics, a supermatrix is a Z2-graded analog of an ordinary matrix. Specifically, a supermatrix is a 2×2 block matrix with entries in a superalgebra (or superring). The most important examples are those with entries in a commutative superalgebra (such as a Grassmann algebra) or an ordinary field (thought of as a purely even commutative superalgebra).
Supermatrices arise in the study of super linear algebra where they appear as the coordinate representations of a linear transformations between finite-dimensional super vector spaces or free supermodules. They have important applications in the field of supersymmetry.
Definitions and notation
Let R be a fixed superalgebra (assumed to be unital and associative). Often one requires R be supercommutative as well (for essentially the same reasons as in the ungraded case).
Let p, q, r, and s be nonnegative integers. A supermatrix of dimension (r|s)×(p|q) is a matrix with entries in R that is partitioned into a 2×2 block structure
with r+s total rows and p+q total columns (so that the submatrix X00 has dimensions r×p and X11 has dimensions s×q). An ordinary (ungraded) matrix can be thought of as a supermatrix for which q and s are both zero.
A square supermatrix is one for which (r|s) = (p|q). This means that not only is the unpartitioned matrix X square, but the diagonal blocks X00 and X11 are as well.
An even supermatrix is one for which the diagonal blocks (X00 and X11) consist solely of even elements of R (i.e. homogeneous elements of parity 0) and the off-diagonal blocks (X01 and X10) consist solely of odd elements of R.
An odd supermatrix is one for which the reverse holds: the diagonal blocks are odd and the off-diagonal blocks are even.
If the scalars R are purely even there are no nonzero odd elements, so the even supermatices are the block diagonal ones and the odd supermatrices are the off-diagonal ones.
A supermatrix is homogeneous if it is either even or odd. The parity,
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https://en.wikipedia.org/wiki/Decision-matrix%20method
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The decision-matrix method, also Pugh method or Pugh concept selection, invented by Stuart Pugh, is a qualitative technique used to rank the multi-dimensional options of an option set. It is frequently used in engineering for making design decisions but can also be used to rank investment options, vendor options, product options or any other set of multidimensional entities.
Definition
A basic decision matrix consists of establishing a set of criteria and a group of potential candidate designs. One of these is a reference candidate design. The other designs are then compared to this reference design and being ranked as better, worse, or same based on each criterion. The number of times "better" and "worse" appeared for each design is then displayed, but not summed up.
A weighted decision matrix operates in the same way as the basic decision matrix but introduces the concept of weighting the criteria in order of importance. The more important the criterion the higher the weighting it should be given.
Advantages
The advantage of the decision-making matrix is that it encourages self-reflection amongst the members of a design team to analyze each candidate with a minimized bias (for team members can be biased towards certain designs, such as their own). Another advantage of this method is that sensitivity studies can be performed. An example of this might be to see how much your opinion would have to change in order for a lower ranked alternative to outrank a competing alternative.
Disadvantages
However, there are some important disadvantages of the decision-matrix method:
The list of criteria options is arbitrary. There is no way to know a priori if the list is complete; it is likely that important criteria are missing.
Conversely, it is possible that less important criteria are included, causing decision makers to be distracted and biased in their choice of options.
Scoring methods, even with weighting, tend to equalize all the requirements. But a few re
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https://en.wikipedia.org/wiki/Fibonacci%20prime
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A Fibonacci prime is a Fibonacci number that is prime, a type of integer sequence prime.
The first Fibonacci primes are :
2, 3, 5, 13, 89, 233, 1597, 28657, 514229, 433494437, 2971215073, ....
Known Fibonacci primes
It is not known whether there are infinitely many Fibonacci primes. With the indexing starting with , the first 37 indices n for which Fn is prime are :
n = 3, 4, 5, 7, 11, 13, 17, 23, 29, 43, 47, 83, 131, 137, 359, 431, 433, 449, 509, 569, 571, 2971, 4723, 5387, 9311, 9677, 14431, 25561, 30757, 35999, 37511, 50833, 81839, 104911, 130021, 148091, 201107.
(Note that the actual values Fn rapidly become very large, so, for practicality, only the indices are listed.)
In addition to these proven Fibonacci primes, several probable primes have been found:
n = 397379, 433781, 590041, 593689, 604711, 931517, 1049897, 1285607, 1636007, 1803059, 1968721, 2904353, 3244369, 3340367, 4740217, 6530879.
Except for the case n = 4, all Fibonacci primes have a prime index, because if a divides b, then also divides (but not every prime index results in a Fibonacci prime). That is to say, the Fibonacci sequence is a divisibility sequence.
Fp is prime for 8 of the first 10 primes p; the exceptions are F2 = 1 and F19 = 4181 = 37 × 113. However, Fibonacci primes appear to become rarer as the index increases. Fp is prime for only 26 of the 1,229 primes p below 10,000. The number of prime factors in the Fibonacci numbers with prime index are:
0, 1, 1, 1, 1, 1, 1, 2, 1, 1, 2, 3, 2, 1, 1, 2, 2, 2, 3, 2, 2, 2, 1, 2, 4, 2, 3, 2, 2, 2, 2, 1, 1, 3, 4, 2, 4, 4, 2, 2, 3, 3, 2, 2, 4, 2, 4, 4, 2, 5, 3, 4, 3, 2, 3, 3, 4, 2, 2, 3, 4, 2, 4, 4, 4, 3, 2, 3, 5, 4, 2, 1, ...
, the largest known certain Fibonacci prime is F201107, with 42029 digits. It was proved prime by Maia Karpovich in September 2023. The largest known probable Fibonacci prime is F6530879. It was found by Ryan Propper in August 2022.
It was proved by Nick MacKinnon that the only Fibonacci numbers that are also twin
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https://en.wikipedia.org/wiki/Kan%20extension
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Kan extensions are universal constructs in category theory, a branch of mathematics. They are closely related to adjoints, but are also related to limits and ends. They are named after Daniel M. Kan, who constructed certain (Kan) extensions using limits in 1960.
An early use of (what is now known as) a Kan extension from 1956 was in homological algebra to compute derived functors.
In Categories for the Working Mathematician Saunders Mac Lane titled a section "All Concepts Are Kan Extensions", and went on to write that
The notion of Kan extensions subsumes all the other fundamental concepts of category theory.
Kan extensions generalize the notion of extending a function defined on a subset to a function defined on the whole set. The definition, not surprisingly, is at a high level of abstraction. When specialised to posets, it becomes a relatively familiar type of question on constrained optimization.
Definition
A Kan extension proceeds from the data of three categories
and two functors
,
and comes in two varieties: the "left" Kan extension and the "right" Kan extension of along .
The right Kan extension amounts to finding the dashed arrow and the natural transformation in the following diagram:
Formally, the right Kan extension of along consists of a functor and a natural transformation that is couniversal with respect to the specification, in the sense that for any functor and natural transformation , a unique natural transformation is defined and fits into a commutative diagram:
where is the natural transformation with for any object of
The functor R is often written .
As with the other universal constructs in category theory, the "left" version of the Kan extension is dual to the "right" one and is obtained by replacing all categories by their opposites.
The effect of this on the description above is merely to reverse the direction of the natural transformations.
(Recall that a natural transformation between the functors consis
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https://en.wikipedia.org/wiki/Windows%20CE%205.0
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Windows CE 5.0 (codenamed "Macallan") is a successor to Windows CE 4.2, the third release in the Windows CE .NET family. It was first released on July 9, 2004. Like its predecessors, Windows CE 5.0 is marketed towards the embedded device market and independent device vendors. Windows CE 5.0 is billed as a low-cost, compact, fast-to-market, real-time operating system available for x86, ARM, MIPS, and SuperH microprocessor-based systems.
Windows CE 5.0 builds on previous Windows CE releases in its adoption of shared source. Since 2001, Microsoft has been steadily expanding the available Windows CE source tree with embedded system developers. Windows CE 5.0 is the most open Microsoft operating system to date, though not all of the system is available under shared source agreements. Developers have the freedom to modify down to the kernel level, without the need to share their changes with Microsoft or competitors.
Windows CE 5.x is the base OS for Windows Mobile 6.0, 6.1 and 6.5. On the x86 platform, Windows CE 5.0 competes against Microsoft's other embedded operating systems, Windows XP Embedded and its predecessor Windows NT Embedded.
Platform Builder IDE for Windows CE 5.0 is the last builder tool available as standalone product.
Windows CE vs. Windows XP Embedded
According to Microsoft, Windows CE is preferable to Windows XP Embedded in situations where demanding wireless and multimedia requirements need to be met. The following are the primary considerations for “choosing the right version”:
CPU architecture: Windows CE supports an extensive array of architectures, including x86, whereas Windows XP Embedded only supports the x86 architecture.
Real-time applications: Windows CE is a real-time operating system, while Windows XP Embedded is not by default.
Existing Win32 applications: Windows CE cannot use Win32 binaries, libraries, and drivers without modification.
Memory footprint: The minimum footprint of Windows CE is 350 kilobytes. The minimum footprint
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https://en.wikipedia.org/wiki/Nested%20radical
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In algebra, a nested radical is a radical expression (one containing a square root sign, cube root sign, etc.) that contains (nests) another radical expression. Examples include
which arises in discussing the regular pentagon, and more complicated ones such as
Denesting
Some nested radicals can be rewritten in a form that is not nested. For example,
Another simple example,
Rewriting a nested radical in this way is called denesting. This is not always possible, and, even when possible, it is often difficult.
Two nested square roots
In the case of two nested square roots, the following theorem completely solves the problem of denesting.
If and are rational numbers and is not the square of a rational number, there are two rational numbers and such that
if and only if is the square of a rational number .
If the nested radical is real, and are the two numbers
and where is a rational number.
In particular, if and are integers, then and are integers.
This result includes denestings of the form
as may always be written and at least one of the terms must be positive (because the left-hand side of the equation is positive).
A more general denesting formula could have the form
However, Galois theory implies that either the left-hand side belongs to or it must be obtained by changing the sign of either or both. In the first case, this means that one can take and In the second case, and another coefficient must be zero. If one may rename as for getting Proceeding similarly if it results that one can suppose This shows that the apparently more general denesting can always be reduced to the above one.
Proof: By squaring, the equation
is equivalent with
and, in the case of a minus in the right-hand side,
(square roots are nonnegative by definition of the notation). As the inequality may always be satisfied by possibly exchanging and , solving the first equation in and is equivalent with solving
This equality implies that bel
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https://en.wikipedia.org/wiki/Historical%20Dictionary%20of%20Switzerland
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The Historical Dictionary of Switzerland (Dictionnaire historique de la Suisse; DHS) is an encyclopedia on the history of Switzerland. It aims to present the history of Switzerland in the form of an encyclopaedia, published both on paper and on the Internet, in three of the country's national languages: German, French and Italian. When it was completed at the end of 2014, the paper version contained around 36,000 articles divided into thirteen volumes.At the same time, a reduced edition of the dictionary has been published in Romansh under the title Lexicon istoric retic (LIR), and constitutes the first specialist dictionary in the Rhaeto-Romance, Switzerland.
The encyclopedia is published by a foundation under the patronage of the Swiss Academy of Humanities and Social Sciences (SAGW/ASSH) and the Swiss Historical Society (SGG-SHH) and is financed by national research grants.
History of the project
A tradition of historical dictionaries
Since the time of the illustrated chronicles of Diebold Schilling the Elder in the fifteenth century, numerous historical works have appeared in Switzerland: the Chronicon Helveticum by Aegidius Tschudi (1569) contains around a thousand documents, the twenty volumes of the encyclopaedic dictionary Allgemeines Helvetisches, Eydgenössisches, Oder Schweitzerisches Lexicon (General Helvetic, Federal or Swiss Lexicon) were written by Zurich banker and politician between 1747 and 1765,. followed by the Dictionnaire géographique et statistique de la Suisse (Geographical and Statistical Dictionary of Switzerland) by .
The last Swiss historical dictionary to appear between the two world wars was the Dictionnaire historique et biographique de la Suisse (DHBS, Historical & Biographical Dictionary of Switzerland), published in seven volumes between 1921 and 1934. Edited by from Neuchâtel, it was a financial failure, mainly because of the lack of supervision of the authors, who were largely recruited by the cantonal archivists associat
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https://en.wikipedia.org/wiki/Superstabilization
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Superstabilization is a concept of fault-tolerance in distributed computing. Superstabilizing distributed algorithms combine the features of self-stabilizing algorithms and dynamic algorithms. A superstabilizing algorithm – just like any other self-stabilizing algorithm – can be started in an arbitrary state, and it will eventually converge to a legitimate state. Additionally, a superstabilizing algorithm will recover rapidly from a single change in the network topology (adding or removing one edge or node in the network).
Any self-stabilizing algorithm recovers from a change in the network topology – the system configuration after a topology change can be treated just like any other arbitrary starting configuration. However, in a self-stabilizing algorithm, the convergence after a single change in the network topology may be as slow as the convergence from an arbitrary starting state. In the study of superstabilizing algorithms, special attention is paid to the time it takes to recover from a single change in the network topology.
Definitions
The stabilization time of a superstabilizing algorithm is defined exactly as in the case of self-stabilizing algorithm: how long it takes to converge to a legitimate state from an arbitrary configuration. Depending on the computational model, time is measured, e.g., in synchronous communication rounds or in asynchronous cycles.
The superstabilization time is the time to recover from a single topology change. It is assumed that the system is initially in a legitimate configuration. Then the network topology is changed; the superstabilization time is the maximum time it takes for the system to reach a legitimate configuration again. Similarly, the adjustment measure is the maximum number of nodes that have to change their state after such changes.
The “almost-legitimate configurations” which occur after one topology change can be formally modelled by using passage predicates: a passage predicate is a predicate that holds af
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https://en.wikipedia.org/wiki/IEEE%20802.18
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IEEE 802.18, the Radio Regulatory Technical Advisory Group ("RR-TAG"), is a working group of IEEE 802, the LAN/MAN Standards Committee (LMCS). The working group currently has 6 projects on standards for radio-based systems:
IEEE 802.11 (Wireless Local area network- WLAN)
IEEE 802.15 (Wireless Personal area network - WPAN)
IEEE 802.16 (Wireless Metropolitan area network - WMAN)
IEEE 802.20 (Wireless Mobility)
IEEE 802.21 (Hand-off/Interoperability Between Networks)
IEEE 802.22 (Wireless Regional Area Network - WRAN).
The RR-TAG monitors the interests of the above 6 projects, at both national and international levels, and then makes comments and recommends policies to regulators, which balance the interests of all the wireless LMCS projects.
References
External links
IEEE 802
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https://en.wikipedia.org/wiki/VESA%20Digital%20Flat%20Panel
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The VESA Digital Flat Panel (DFP) interface standard specifies a video connector and digital TMDS signaling for flat-panel displays. It features 20 pins and uses the PanelLink protocol; the standard is based on the preceding VESA Plug and Display (P&D) standard, ratified in 1997. Unlike the later, electrically-compatible Digital Visual Interface (DVI, 1999), DFP never achieved widespread implementation.
History
P&D combined analog and digital video with data over USB and FireWire to reduce cable clutter, but the feature creep resulted in an unpopular, expensive connector. Compaq described DFP as a "transition" step between the analog VGA connector and P&D: DFP was designed by a consortium including Compaq, Hewlett-Packard, and ATI Technologies as a smaller, simpler connector, dropping support for analog video and data in favor of transmitting exclusively digital video signals.
The connector was used by displays such as the Compaq Presario FP400, FP500, FP700, Fp720, 5204, and 5280. It was offered on graphics cards such as the Xpert LCD, and Rage LT Pro by ATI Technologies, and the Oxygen GVX1 by 3Dlabs.
Design
DFP is compatible electrically with P&D (and by extension, DVI); DFP uses the Display Data Channel (DDC) standard level DDC2B for operation and the Extended Display Identification Data (EDID) protocol to identify the display to the host. Like the preceding P&D, DFP uses the PanelLink TMDS protocol developed by Silicon Image for digital video signals.
The DFP standard specifies a 20-pin mini D ribbon connector; however, as the signal protocols are identical, DFP connectors generally are compatible with devices equipped with a DVI interface by using a passive adaptor.
All DFP-compliant devices are required to support resolutions of 640×400, 720×400, and 640×480 (each at a refresh rate of 60Hz) as a minimum level of interoperability, although the resulting display may not necessarily be centered or scaled.
DFP was superseded by DVI because DFP, like P&D, is
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https://en.wikipedia.org/wiki/Trailblazer%20%28video%20game%29
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Trailblazer is a racing video game developed by Mr. Chip Software and published by Gremlin Graphics for the ZX Spectrum, Commodore 64, Atari 8-bit family, Amstrad CPC and Commodore 16/Plus/4 in 1986 (there was also an enhanced version on Amstrad CPC 3" disc). It was ported to the Amiga and Atari ST.
In 2005 a remake for the Gizmondo was released, and was also adapted in 2011 for the PS3, PlayStation Portable, PS Vita and PlayStation TV as part of the Playstation Mini series.
The game received a direct sequel titled Cosmic Causeway: Trailblazer II in 1987.
Gameplay
Trailblazer is a racing game which players play as a soccer ball along a series of suspended passages. The game can be played either in time trial or arcade mode and four track. The races usually last between 15 and 45 seconds. Special fields on the track let the ball jump (blue), slow down (red), speed up (green) or warp speed the ball (white), invert the controls (cyan/light blue), bounce it backwards (purple) or are holes (black).
Development
Shaun Southern had made some great games for the Commodore 16 before he moved onto the Amiga and the game was inspired by the arcade game Metrocross.
Reception
The game was reviewed in 1990 in Dragon #158 by Hartley, Patricia, and Kirk Lesser in "The Role of Computers" column, as part of the Mastertronic MEGA Pack of 10 games previously released in Europe. The reviewers gave the game 5 out of 5 stars, stating: "Our favorite on this disk; racing on Cosmic Causeway roads against the clock or against a robot. This one was really fun".
Zzap!64'''s reviewers also enjoyed the game which they thought was "an excellent variation on the race game theme". The overall rating given was 93%, qualifying the C64 version for the magazine's Sizzler award. Steve Panak, reviewing the Atari 8-bit version for ANALOG Computing, concluded that "the game is the most original arcade action wristbuster to come down the pike in a long time, and one of the best two-player competition
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https://en.wikipedia.org/wiki/SMBRelay
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SMBRelay and SMBRelay2 are computer programs that can be used to carry out SMB man-in-the-middle (mitm) attacks on Windows machines. They were written by Sir Dystic of CULT OF THE DEAD COW (cDc) and released March 21, 2001 at the @lantacon convention in Atlanta, Georgia. More than seven years after its release, Microsoft released a patch that fixed the hole exploited by SMBRelay. This fix only fixes the vulnerability when the SMB is reflected back to the client. If it is forwarded to another host, the vulnerability can be still exploited.
SMBRelay
SMBrelay receives a connection on UDP port 139 and relays the packets between the client and server of the connecting Windows machine to the originating computer's port 139. It modifies these packets when necessary.
After connecting and authenticating, the target's client is disconnected and SMBRelay binds to port 139 on a new IP address. This relay address can then be connected to directly using "net use \\192.1.1.1" and then used by all of the networking functions built into Windows. The program relays all of the SMB traffic, excluding negotiation and authentication. As long as the target host remains connected, the user can disconnect from and reconnect to this virtual IP.
SMBRelay collects the NTLM password hashes and writes them to hashes.txt in a format usable by L0phtCrack for cracking at a later time.
As port 139 is a privileged port and requires administrator access for use, SMBRelay must run as an administrator access account. However, since port 139 is needed for NetBIOS sessions, it is difficult to block.
According to Sir Dystic, "The problem is that from a marketing standpoint, Microsoft wants their products to have as much backward compatibility as possible; but by continuing to use protocols that have known issues, they continue to leave their customers at risk to exploitation... These are, yet again, known issues that have existed since day one of this protocol. This is not a bug but a fundamental
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https://en.wikipedia.org/wiki/Super%20Cobra
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Super Cobra is a horizontally scrolling shooter developed by Konami, originally released as an arcade video game in 1981. It was published by Konami in Japan in March 1981 and manufactured and distributed by Stern in North America on June 22. It is the spiritual sequel to the Scramble arcade game released earlier in 1981. Super Cobra contains eleven distinct sections, versus six in Scramble, and is significantly more difficult, requiring maneuvering through tight spaces early in the game.
The game was a commercial success, selling 12,337 arcade cabinets in the United States within four months, becoming Stern's third best-selling arcade game. Super Cobra was widely ported by Parker Brothers, and there are Adventure Vision and standalone versions from Entex.
Gameplay
The player controls a helicopter through tight caverns, and the slightest misstep will result in the loss of a life. However, unlike Scramble, the game can be continued where the player left off by adding more credits and pressing FIRE (but he/she loses all points upon continuing).
The joystick accelerates, decelerates, moves up, and moves down. The helicopter uses a laser and bomb to destroy defenders, tanks, and UFOs while infiltrating 10 Super Cobra defense systems.
The ship has a limited fuel supply, which is depleted over time. More fuel can be acquired by destroying fuel tanks in the game.
The game is divided into ten sections, plus a finale, each with a different style of terrain and different obstacles. Players navigate through ten levels and a base, where they must safely make it through the level and remove the booty. The levels are described as follows:
Player must maneuver the chopper over mountainous terrain against fast and slow firing rockets.
Chopper faces Arcing missiles over a mountain terrain.
Smart Bombs flying in groups of four over mountainous terrain. Rockets appear, but do not fire.
Single Smart Bombs over mountainous terrain. Again, Rockets appear, but do not fire.
Cho
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https://en.wikipedia.org/wiki/Hormonal%20sentience
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Hormonal sentience, first described by Robert A. Freitas Jr., describes the information processing rate in plants, which are mostly based on hormones instead of neurons like in all major animals (except sponges). Plants can to some degree communicate with each other and there are even examples of one-way-communication with animals.
Acacia trees produce tannin to defend themselves when they are grazed upon by animals. The airborne scent of the tannin is picked up by other acacia trees, which then start to produce tannin themselves as a protection from the nearby animals.
When attacked by caterpillars, some plants can release chemical signals to attract parasitic wasps that attack the caterpillars.
A similar phenomenon can be found not only between plants and animals, but also between fungi and animals. There exists some sort of communication between a fungus garden and workers of the leaf-cutting ant Atta sexdens rubropilosa. If the garden is fed with plants that are poisonous for the fungus, it signals this to the ants, which then will avoid fertilizing the fungus garden with any more of the poisonous plant.
The Venus flytrap, during a 1- to 20-second sensitivity interval, counts two stimuli before snapping shut on its insect prey, a processing peak of 1 bit/s. Mass is 10–100 grams, so the flytrap's SQ is about +1. Plants generally take hours to respond to stimuli though, so vegetative SQs (Sentience Quotient) tend to cluster around -2.
See also
Biosemiotics
Phytosemiotics
Plant cognition
Plant perception (physiology)
:Category:Plant cognition
References
External links
Xenopsychology by Robert A. Freitas Jr.
Botany
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https://en.wikipedia.org/wiki/List%20of%20fractals%20by%20Hausdorff%20dimension
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According to Benoit Mandelbrot, "A fractal is by definition a set for which the Hausdorff-Besicovitch dimension strictly exceeds the topological dimension."
Presented here is a list of fractals, ordered by increasing Hausdorff dimension, to illustrate what it means for a fractal to have a low or a high dimension.
Deterministic fractals
Random and natural fractals
See also
Fractal dimension
Hausdorff dimension
Scale invariance
Notes and references
Further reading
External links
The fractals on Mathworld
Other fractals on Paul Bourke's website
Soler's Gallery
Fractals on mathcurve.com
1000fractales.free.fr - Project gathering fractals created with various software
Fractals unleashed
IFStile - software that computes the dimension of the boundary of self-affine tiles
Hausdorff Dimension
Hausdorff Dimension
Mathematics-related lists
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https://en.wikipedia.org/wiki/MultiDimensional%20eXpressions
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Multidimensional Expressions (MDX) is a query language for online analytical processing (OLAP) using a database management system. Much like SQL, it is a query language for OLAP cubes. It is also a calculation language, with syntax similar to spreadsheet formulae.
Background
The MultiDimensional eXpressions (MDX) language provides a specialized syntax for querying and manipulating the multidimensional data stored in OLAP cubes. While it is possible to translate some of these into traditional SQL, it would frequently require the synthesis of clumsy SQL expressions even for very simple MDX expressions. MDX has been embraced by a wide majority of OLAP vendors and has become the standard for OLAP systems.
History
MDX was first introduced as part of the OLE DB for OLAP specification in 1997 from Microsoft. It was invented by the group of SQL Server engineers including Mosha Pasumansky. The specification was quickly followed by commercial release of Microsoft OLAP Services 7.0 in 1998 and later by Microsoft Analysis Services. The latest version of the OLE DB for OLAP specification was issued by Microsoft in 1999.
While it was not an open standard, but rather a Microsoft-owned specification, it was adopted by a wide range of OLAP vendors.
The XML for Analysis specification referred back to the OLE DB for OLAP specification for details on the MDX Query Language. In Analysis Services 2005, Microsoft added some MDX Query Language extensions like subselects. Products like Microsoft Excel 2007 started to use these new MDX Query Language extensions. Some refer to this newer variant of MDX as MDX 2005.
mdXML
In 2001 the XMLA Council released the XML for Analysis (XMLA) standard, which included mdXML as a query language. In the XMLA 1.1 specification, mdXML is essentially MDX wrapped in the XML <Statement> tag.
MDX data types
There are six primary data types in MDX
Scalar. Scalar is either a number or a string. It can be specified as a literal, e.g. number 5 or string "
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https://en.wikipedia.org/wiki/Aposematism
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Aposematism is the advertising by an animal to potential predators that it is not worth attacking or eating. This unprofitability may consist of any defenses which make the prey difficult to kill and eat, such as toxicity, venom, foul taste or smell, sharp spines, or aggressive nature. These advertising signals may take the form of conspicuous coloration, sounds, odours, or other perceivable characteristics. Aposematic signals are beneficial for both predator and prey, since both avoid potential harm.
The term was coined in 1877 by Edward Bagnall Poulton for Alfred Russel Wallace's concept of warning coloration. Aposematism is exploited in Müllerian mimicry, where species with strong defences evolve to resemble one another. By mimicking similarly coloured species, the warning signal to predators is shared, causing them to learn more quickly at less of a cost.
A genuine aposematic signal that a species actually possesses chemical or physical defences is not the only way to deter predators. In Batesian mimicry, a mimicking species resembles an aposematic model closely enough to share the protection, while many species have bluffing deimatic displays which may startle a predator long enough to enable an otherwise undefended prey to escape.
There is good evidence for aposematism in terrestrial animals; its existence in marine animals is possible but disputed.
Etymology
The term aposematism was coined by the English zoologist Edward Bagnall Poulton in his 1890 book The Colours of Animals. He based the term on the Ancient Greek words ἀπό apo 'away' and σῆμα sēma 'sign', referring to signs that warn other animals away.
Defense mechanism
The function of aposematism is to prevent attack, by warning potential predators that the prey animal has defenses such as being unpalatable or poisonous. The easily detected warning is a primary defense mechanism, and the non-visible defenses are secondary. Aposematic signals are primarily visual, using bright colors and high-con
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https://en.wikipedia.org/wiki/Communalness
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Communalness, as suggested by Robert A. Freitas Jr., is a level of an emergent phenomenon which originates from electronic sentience, and represents a broader mode of thinking than just normal consciousness. While consciousness is limited to the individual, communalness describes a complex organization of numerous individuals which on a higher level is tightly connected to each other. Such an organization would maybe have the same intimate awareness of its own existence as a whole as people have consciousness of their own bodies.
See also
Collective consciousness
Collective identity
Collective intelligence
Collective memory
Group mind (science fiction)
Hormonal sentience
Neurohacking
External links
Xenopsychology by Robert A. Freitas Jr.
Science fiction themes
Consciousness
Superorganisms
Emergence
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https://en.wikipedia.org/wiki/31-bit%20computing
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In computer architecture, 31-bit integers, memory addresses, or other data units are those that are 31 bits wide.
In 1983, IBM introduced 31-bit addressing in the System/370-XA mainframe architecture as an upgrade to the 24-bit physical and virtual, and transitional 24-bit-virtual/26-bit physical, addressing in System/370. This enhancement allowed address spaces to be 128 times larger, permitting programs to address memory above 16 MB (referred to as "above the line"). Support for COBOL, FORTRAN and later on Linux/390 were included.
In the early 1980s, the Motorola 68012 was introduced; it had 32-bit data and address registers, as the Motorola 68010 did, but instead of providing the lower 24 bits of an address on the address pins, it provided all but bit 30 on the address pins.
31-bit computer
The Librascope LGP-30 was an early off-the-shelf computer. The LGP-30 was first manufactured in 1956, at a retail price of $47,000, .
It was a binary, 31-bit word computer with a 4096-word drum memory. There were 32 bit locations per drum word, but only 31 were used, permitting a "restoration of magnetic flux in the head" at the 32nd bit time. The number of vacuum tubes was minimized by using solid-state diode logic, a bit-serial architecture and multiple use of each of its 15 flip-flops.
The LGP-30 was commonly referred to as a desk computer. Its height, width, and depth, excluding the typewriter shelf, was 33 by 44 by 26 inches (84 by 112 by 66 cm). It weighed about 800 pounds (360 kg), and was mounted on sturdy casters which facilitated moving the unit.
IBM mainframes with 31-bit addressing
In the System/360, other than the 360/67, and early System/370 architectures, the general-purpose registers were 32 bits wide, the machine did 32-bit arithmetic operations, and addresses were always stored in 32-bit words, so the architecture was considered 32-bit, but the machines ignored the top 8 bits of the address resulting in 24-bit addressing.
With the System/370-XA archit
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https://en.wikipedia.org/wiki/24-bit%20computing
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Notable 24-bit machines include the CDC 924 – a 24-bit version of the CDC 1604, CDC lower 3000 series, SDS 930 and SDS 940, the ICT 1900 series, the Elliott 4100 series, and the Datacraft minicomputers/Harris H series.
The term SWORD is sometimes used to describe a 24-bit data type with the S prefix referring to sesqui.
The range of unsigned integers that can be represented in 24 bits is 0 to 16,777,215 ( in hexadecimal). The range of signed integers that can be represented in 24 bits is −8,388,608 to 8,388,607.
Usage
The IBM System/360, announced in 1964, was a popular computer system with 24-bit addressing and 32-bit general registers and arithmetic. The early 1980s saw the first popular personal computers, including the IBM PC/AT with an Intel 80286 processor using 24-bit addressing and 16-bit general registers and arithmetic, and the Apple Macintosh 128K with a Motorola 68000 processor featuring 24-bit addressing and 32-bit registers.
The eZ80 is a microprocessor and microcontroller family, with 24-bit registers and therefore 24-bit linear addressing, that is binary compatible with the 8/16-bit Z80.
The 65816 is a microprocessor and microcontroller family with 16-bit registers and 24-bit bank switched addressing. It is binary compatible with the 8-bit 6502.
Several fixed-point digital signal processors have a 24-bit data bus, selected as the basic word length because it gave the system a reasonable precision for the processing audio (sound). In particular, the Motorola 56000 series has three parallel 24-bit data buses, one connected to each memory space: program memory, data memory X, and data memory Y.
Engineering Research Associates (later merged into UNIVAC) designed a series of 24-bit drum memory machines including the Atlas, its commercial version the UNIVAC 1101, the ATHENA computer, the UNIVAC 1824 guidance computer, etc. Those designers selected a 24-bit word length because the Earth is roughly 40 million feet in diameter, and an intercontinen
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https://en.wikipedia.org/wiki/Microchimerism
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Microchimerism is the presence of a small number of cells in an individual that have originated from another individual and are therefore genetically distinct. This phenomenon may be related to certain types of autoimmune diseases although the responsible mechanisms are unclear. The term comes from the prefix "micro" + "chimerism" based on the hybrid Chimera of Greek mythology. The concept was first discovered in the 1960s with the term gaining usage in the 1970s.
Types
Human
In humans (and perhaps in all placentals), the most common form is fetomaternal microchimerism (also known as fetal cell microchimerism or fetal chimerism) whereby cells from a fetus pass through the placenta and establish cell lineages within the mother. Fetal cells have been documented to persist and multiply in the mother for several decades. The exact phenotype of these cells is unknown, although several different cell types have been identified, such as various immune lineages, mesenchymal stem cells, and placental-derived cells. A 2012 study at the Fred Hutchinson Cancer Research Center, Seattle, has detected cells with the Y chromosome in multiple areas of the brains of deceased women.
Fetomaternal microchimerism occurs during pregnancy and shortly after giving birth for most women. However, not all women who have had children contain fetal cells. Studies suggest that fetomaternal microchimerism could be influenced by killer-cell immunoglobulin-like (KIR) ligands. Lymphocytes also influence the development of persisting fetomaternal microchimerism since natural killer cells compose about 70% of lymphocytes in the first trimester of pregnancy. KIR patterns on maternal natural killer cells of the mother and KIR ligands on the fetal cells could have an effect on fetomaternal microchimerism. In one study, mothers with KIR2DS1 exhibited higher levels of fetomaternal microchimerism compared to mothers who were negative for this activating KIR.
The potential health consequences of these cel
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