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https://en.wikipedia.org/wiki/Project%20ROSE
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Project ROSE ("Retrofit of Strike Element") was a program by the Pakistan Air Force to upgrade of the avionics of its ageing Dassault Mirage III and Mirage 5 fighter jets,. These had originally been built either by Dassault Aviation in France, or by the Government Aircraft Factories (GAF) in Australia. The program, based at the Pakistan Aeronautical Complex, focused on upgrading the military avionics and onboard computer systems, with equipment supplied variously by Pakistani Margella Electronics, French SAGEM and Italian SELEX consortia.
Conceived in 1992 by the Pakistan Air Force, the program started in 1995 on main considerations of retiring the A–5 Fantan from active service. The Pakistan Air Force, which was already operating Dassault Mirage IIIs and Mirage 5s, began its procurement of second-hand Mirage fighters from Australia, Lebanon, Libya, and Spain at the price range within the MoD's financial capacities. Over 90% of the aircraft were retrofitted at the Pakistan Aeronautical Complex in Kamra; few were upgraded in France. Between 1996 and 2000, several Mirage IIIs and Mirage 5s were bought from other countries and were upgraded under this program at the Pakistan Aeronautical Complex.
The avionics of the aircraft were improved: some aircraft received the Grifo radar with a detection range of about 75 km. In-flight refuelling probes were added on some aircraft too. Their airframes were overhauled, and their service life was increased. After the ROSE-III upgrade, locally manufactured weapons like the H-2 and H-4 SOW, the Takbir glide bomb, and stealth nuclear cruise missiles such as the Ra'ad Mk-1 and Ra'ad Mk-2, were added to the weapons package of the aircraft. Further considerations for upgrades was recommended but the program was terminated due to the increasing cost of spare parts and the condition of the second-hand airframes at the time of their procurement from various countries.
It is currently expected for all ROSE-upgraded Mirage fighter jets r
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https://en.wikipedia.org/wiki/Normal%20form%20%28abstract%20rewriting%29
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In abstract rewriting, an object is in normal form if it cannot be rewritten any further, i.e. it is irreducible. Depending on the rewriting system, an object may rewrite to several normal forms or none at all. Many properties of rewriting systems relate to normal forms.
Definitions
Stated formally, if (A,→) is an abstract rewriting system, x∈A is in normal form if no y∈A exists such that x→y, i.e. x is an irreducible term.
An object a is weakly normalizing if there exists at least one particular sequence of rewrites starting from a that eventually yields a normal form. A rewriting system has the weak normalization property or is (weakly) normalizing (WN) if every object is weakly normalizing. An object a is strongly normalizing if every sequence of rewrites starting from a eventually terminates with a normal form. An abstract rewriting system is strongly normalizing, terminating, noetherian, or has the (strong) normalization property (SN), if each of its objects is strongly normalizing.
A rewriting system has the normal form property (NF) if for all objects a and normal forms b, b can be reached from a by a series of rewrites and inverse rewrites only if a reduces to b. A rewriting system has the unique normal form property (UN) if for all normal forms a, b ∈ S, a can be reached from b by a series of rewrites and inverse rewrites only if a is equal to b. A rewriting system has the unique normal form property with respect to reduction (UN→) if for every term reducing to normal forms a and b, a is equal to b.
Results
This section presents some well known results. First, SN implies WN.
Confluence (abbreviated CR) implies NF implies UN implies UN→. The reverse implications do not generally hold. {a→b,a→c,c→c,d→c,d→e} is UN→ but not UN as b=e and b,e are normal forms. {a→b,a→c,b→b} is UN but not NF as b=c, c is a normal form, and b does not reduce to c. {a→b,a→c,b→b,c→c} is NF as there are no normal forms, but not CR as a reduces to b and c, and b,c have no comm
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https://en.wikipedia.org/wiki/Mini-DVI
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The Mini-DVI connector is used on certain Apple computers as a digital alternative to the Mini-VGA connector. Its size is between the full-sized DVI and the tiny Micro-DVI. It is found on the 12-inch PowerBook G4 (except the original 12-inch 867 MHz PowerBook G4, which used Mini-VGA), the Intel-based iMac, the MacBook Intel-based laptop, the Intel-based Xserve, the 2009 Mac mini, and some late model eMacs.
In October 2008, Apple announced the company was phasing Mini-DVI out in favor of Mini DisplayPort.
Mini-DVI connectors on Apple hardware are capable of carrying DVI, VGA, or TV signals through the use of adapters, detected with EDID (Extended display identification data) via DDC. This connector is often used in place of a DVI connector in order to save physical space on devices. Mini-DVI does not support dual-link connections and hence cannot support resolutions higher than 1920×1200 @60 Hz.
There are various types of Mini-DVI adapter:
Apple Mini-DVI to VGA Adapter Apple part number M9320G/A (discontinued)
Apple Mini-DVI to Video Adapter Apple part number M9319G/A, provided both S-Video and Composite video connectors (discontinued)
Apple Mini-DVI to DVI Adapter (DVI-D) Apple part number M9321G/B (discontinued)
Non-OEM Mini-DVI to HDMI adapters are also available at online stores such as eBay and Amazon, and from some retail stores, but were not sold by Apple.
The physical connector is similar to Mini-VGA, but is differentiated by having four rows of pins arranged in two vertically stacked slots rather than the two rows of pins in the Mini-VGA.
Connecting to a DVI-I connector requires a Mini-DVI to DVI-D cable plus a DVI-D to DVI-I adapter.
Criticisms
Apple's Mini-DVI to DVI-D cable does not carry the analog signal coming from the mini-DVI port on the Apple computer. This means that it is not possible to use this cable with an inexpensive DVI-to-VGA adapter for VGA output; Apple's mini-DVI to VGA cable must be used instead. This could be avoided if Apple pro
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https://en.wikipedia.org/wiki/Fracton
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A fracton is a collective quantized vibration on a substrate with a fractal structure.
Fractons are the fractal analog of phonons. Phonons are the result of applying translational symmetry to the potential in a Schrödinger equation. Fractal self-similarity can be thought of as a symmetry somewhat comparable to translational symmetry. Translational symmetry is symmetry under displacement or change of position, and fractal self-similarity is symmetry under change of scale. The quantum mechanical solutions to such a problem in general lead to a continuum of states with different frequencies. In other words, a fracton band is comparable to a phonon band. The vibrational modes are restricted to part of the substrate and are thus not fully delocalized, unlike phonon vibrational modes. Instead, there is a hierarchy of vibrational modes that encompass smaller and smaller parts of the substrate.
References
External links
The ‘Weirdest’ Matter, Made of Partial Particles, Defies Description
Fractals
Quasiparticles
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https://en.wikipedia.org/wiki/Tanenbaum%E2%80%93Torvalds%20debate
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The Tanenbaum–Torvalds debate was a written debate between Andrew S. Tanenbaum and Linus Torvalds, regarding the Linux kernel and kernel architecture in general. Tanenbaum, the creator of Minix, began the debate in 1992 on the Usenet discussion group , arguing that microkernels are superior to monolithic kernels and therefore Linux was, even in 1992, obsolete.
The debate has sometimes been considered a flame war.
The debate
While the debate initially started out as relatively moderate, with both parties involved making only banal statements about kernel design, it grew progressively more detailed and sophisticated with every round of posts. Besides just kernel design, the debate branched into several other topics, such as which microprocessor architecture would win out over others in the future. Besides Tanenbaum and Torvalds, several other people joined the debate, including Peter MacDonald, an early Linux kernel developer and creator of one of the first distributions, Softlanding Linux System; David S. Miller, one of the core developers of the Linux kernel; and Theodore Ts'o, the first North American Linux kernel developer.
The debate opened on January 29, 1992, when Tanenbaum first posted his criticism on the Linux kernel to , noting how the monolithic design was detrimental to its abilities, in a post titled "LINUX is obsolete". While he initially did not go into great technical detail to explain why he felt that the microkernel design was better, he did suggest that it was mostly related to portability, arguing that the Linux kernel was too closely tied to the x86 line of processors to be of any use in the future, as this architecture would be superseded by then. To put things into perspective, he mentioned how writing a monolithic kernel in 1991 is "a giant step back into the 1970s".
Since the criticism was posted in a public newsgroup, Torvalds was able to respond to it directly. He did so a day later, arguing that MINIX has inherent design flaws (naming
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https://en.wikipedia.org/wiki/Bitopological%20space
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In mathematics, a bitopological space is a set endowed with two topologies. Typically, if the set is and the topologies are and then the bitopological space is referred to as . The notion was introduced by J. C. Kelly in the study of quasimetrics, i.e. distance functions that are not required to be symmetric.
Continuity
A map from a bitopological space to another bitopological space is called continuous or sometimes pairwise continuous if is continuous both as a map from to and as map from to .
Bitopological variants of topological properties
Corresponding to well-known properties of topological spaces, there are versions for bitopological spaces.
A bitopological space is pairwise compact if each cover of with , contains a finite subcover. In this case, must contain at least one member from and at least one member from
A bitopological space is pairwise Hausdorff if for any two distinct points there exist disjoint and with and .
A bitopological space is pairwise zero-dimensional if opens in which are closed in form a basis for , and opens in which are closed in form a basis for .
A bitopological space is called binormal if for every -closed and -closed sets there are -open and -open sets such that , and
Notes
References
Kelly, J. C. (1963). Bitopological spaces. Proc. London Math. Soc., 13(3) 71–89.
Reilly, I. L. (1972). On bitopological separation properties. Nanta Math., (2) 14–25.
Reilly, I. L. (1973). Zero dimensional bitopological spaces. Indag. Math., (35) 127–131.
Salbany, S. (1974). Bitopological spaces, compactifications and completions. Department of Mathematics, University of Cape Town, Cape Town.
Kopperman, R. (1995). Asymmetry and duality in topology. Topology Appl., 66(1) 1--39.
Fletcher. P, Hoyle H.B. III, and Patty C.W. (1969). The comparison of topologies. Duke Math. J.,36(2) 325–331.
Dochviri, I., Noiri T. (2015). On some properties of stable bitopological spaces. Topol. Proc., 45 111–119.
Topology
T
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https://en.wikipedia.org/wiki/Ramp%20function
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The ramp function is a unary real function, whose graph is shaped like a ramp. It can be expressed by numerous definitions, for example "0 for negative inputs, output equals input for non-negative inputs". The term "ramp" can also be used for other functions obtained by scaling and shifting, and the function in this article is the unit ramp function (slope 1, starting at 0).
In mathematics, the ramp function is also known as the positive part.
In machine learning, it is commonly known as a ReLU activation function or a rectifier in analogy to half-wave rectification in electrical engineering. In statistics (when used as a likelihood function) it is known as a tobit model.
This function has numerous applications in mathematics and engineering, and goes by various names, depending on the context. There are differentiable variants of the ramp function.
Definitions
The ramp function () may be defined analytically in several ways. Possible definitions are:
A piecewise function:
The max function:
The mean of an independent variable and its absolute value (a straight line with unity gradient and its modulus): this can be derived by noting the following definition of , for which and
The Heaviside step function multiplied by a straight line with unity gradient:
The convolution of the Heaviside step function with itself:
The integral of the Heaviside step function:
Macaulay brackets:
The positive part of the identity function:
Applications
The ramp function has numerous applications in engineering, such as in the theory of digital signal processing.
In finance, the payoff of a call option is a ramp (shifted by strike price). Horizontally flipping a ramp yields a put option, while vertically flipping (taking the negative) corresponds to selling or being "short" an option. In finance, the shape is widely called a "hockey stick", due to the shape being similar to an ice hockey stick.
In statistics, hinge functions of multivariate adaptive regression
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https://en.wikipedia.org/wiki/Fritz%20Carlson
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Fritz David Carlson (23 July 1888 – 28 November 1952) was a Swedish mathematician. After the death of Torsten Carleman, he headed the Mittag-Leffler Institute.
Carlson's contributions to analysis include Carlson's theorem, the Polyá–Carlson theorem on rational functions, and Carlson's inequality
In number theory, his results include Carlson's theorem on Dirichlet series.
Hans Rådström, Germund Dahlquist, and Tord Ganelius were among his students.
Notes
External links
1888 births
1952 deaths
20th-century Swedish mathematicians
Academic staff of the KTH Royal Institute of Technology
Mathematical analysts
Directors of the Mittag-Leffler Institute
People from Vimmerby Municipality
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https://en.wikipedia.org/wiki/Great%20Wall%20of%20China
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The Great Wall of China (, literally "ten thousand li long wall") is a series of fortifications that were built across the historical northern borders of ancient Chinese states and Imperial China as protection against various nomadic groups from the Eurasian Steppe. Several walls were built from as early as the 7th century BC, with selective stretches later joined by Qin Shi Huang (220–206 BC), the first emperor of China. Little of the Qin wall remains. Later on, many successive dynasties built and maintained multiple stretches of border walls. The best-known sections of the wall were built by the Ming dynasty (1368–1644).
Apart from defense, other purposes of the Great Wall have included border controls, allowing the imposition of duties on goods transported along the Silk Road, regulation or encouragement of trade and the control of immigration and emigration. Furthermore, the defensive characteristics of the Great Wall were enhanced by the construction of watchtowers, troop barracks, garrison stations, signaling capabilities through the means of smoke or fire, and the fact that the path of the Great Wall also served as a transportation corridor.
The frontier walls built by different dynasties have multiple courses. Collectively, they stretch from Liaodong in the east to Lop Lake in the west, from the present-day SinoRussian border in the north to Tao River (Taohe) in the south; along an arc that roughly delineates the edge of the Mongolian steppe; spanning in total. Today, the defensive system of the Great Wall is generally recognized as one of the most impressive architectural feats in history.
Names
The collection of fortifications known as the Great Wall of China has historically had a number of different names in both Chinese and English.
In Chinese histories, the term "Long Wall(s)" ( Chángchéng) appears in Sima Qian's Records of the Grand Historian, where it referred both to the separate great walls built between and north of the Warring States and t
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https://en.wikipedia.org/wiki/Kathleen%20Antonelli
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Kathleen Rita Antonelli ( McNulty; formerly Mauchly;
12 February 1921 – 20 April 2006), known as Kay McNulty, was an Irish computer programmer and one of the six original programmers of the ENIAC, one of the first general-purpose electronic digital computers. The other five ENIAC programmers were Betty Holberton, Ruth Teitelbaum, Frances Spence, Marlyn Meltzer, and Jean Bartik.
Early life and education
She was born Kathleen Rita McNulty in Feymore, part of the small village of Creeslough in what was then a Gaeltacht area (Irish-speaking region) of County Donegal in Ulster, the northern province in Ireland, on February 12, 1921, during the Irish War of Independence. She was the third of six children of James and Anne (née
Nelis) McNulty. On the night of her birth, her father, an Irish Republican Army training officer, was arrested and imprisoned in Derry Gaol for two years as he was a suspected member of the IRA. On his release, the family emigrated to the United States in October 1924 and settled in the Chestnut Hill section of Philadelphia, Pennsylvania, where he found work as a stonemason. At the time, Kathleen McNulty was unable to speak any English, only Irish; she would remember prayers in Irish for the rest of her life.
She attended parochial grade school in Chestnut Hill (1927–1933) and J. W. Hallahan Catholic Girls High School (1933–1938) in Philadelphia. In high school, she had taken a year of algebra, a year of plane geometry, a second year of algebra, and a year of trigonometry and solid geometry. After graduating high school, she enrolled in Chestnut Hill College for Women. During her studies, she took every mathematics course offered, including spherical trigonometry, differential calculus, projective geometry, partial differential equations, and statistics. She graduated with a degree in mathematics in June 1942, one of only a few mathematics majors out of a class of 92 women.
During her third year of college, McNulty was looking for relevant job
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https://en.wikipedia.org/wiki/Windows%20Filtering%20Platform
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Windows Filtering Platform (WFP) is a set of system services in Windows Vista and later that allows Windows software to process and filter network traffic. Microsoft intended WFP for use by firewalls, antimalware software, and parental controls apps. Additionally, WFP is used to implement NAT and to store IPSec policy configuration.
WFP relies on Windows Vista's Next Generation TCP/IP stack. It provides features such as integrated communication and per-application processing logic. Since Windows 8 and Windows Server 2012, WFP allows filtering at the second layer of TCP/IP suite.
Components
The filtering platform includes the following components:
Shims, which expose the internal structure of a packet as properties. Different shims exist for protocols at different layers. WFP comes with a set of shims; users can register shims for other protocols using the API. The in-built set of shims includes:
Application Layer Enforcement (ALE) shim
Transport Layer Module (TLM) shim
Network Layer Module (NLM) shim
RPC Runtime shim
Internet Control Message Protocol (ICMP) shim
Stream shim
Filtering engine, which spans both kernel-mode and user-mode, providing basic filtering capabilities. It matches the data within a packetas exposed by the shimsagainst filtering rules, and either blocks or permits the packet. A callout (see below) may implement any other action as required. The filters operate on a per-application basis. To mitigate conflicts between filters, they are given weights (priorities) and grouped into sublayers, which also have weights. Filters and callouts may be associated to providers which may be given a name and description and are essentially associated to a particular application or service.
Base filtering engine, the module that manages the filtering engine. It accepts filtering rules and enforces the security model of the application. It also maintains statistics for the WFP and logs its state.
Callout, a callback function exposed by a filterin
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https://en.wikipedia.org/wiki/Bob%20Sabiston
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Bob Sabiston (born 1967) is an American film art director, computer programmer, and creator of the Rotoshop software program for computer animation. Sabiston began developing software as an undergraduate and then graduate researcher in the MIT Media Lab from 1986 to 1991. While at MIT, and also after moving to Austin, Texas, in 1993, Sabiston used his 2D/3D software to create several short films, including God's Little Monkey (1994), "Beat Dedication" (1988), and "Grinning Evil Death" (1990). "Grinning Evil Death" was widely seen on the first episode of MTV's "Liquid Television" show. "God's Little Monkey" won the Prix Ars Electronica Golden Nica award for 1994.
In 1997, he developed his interpolating rotoscope program, Rotoshop, for an animation contest sponsored by MTV. The software was used to produce a series of 25 30-second interstitials in New York, collectively entitled "Project Incognito." He moved back to Austin in 1998 and with the help of local artists made the short film "RoadHead." This was followed in 1999 by short "Snack and Drink" in collaboration with Tommy Pallotta. "Snack and Drink" won several film festival awards and resides in the MOMA video collection. The shorts collection "Figures of Speech" followed in late 1999, for PBS. In 2000, Sabiston hired thirty graphic artists in the Austin area to help make Richard Linklater's film Waking Life.
After Waking Life Sabiston spent several years making more rotoscoped short films, including "Yard", "Earthlink Sucks", "Grasshopper". He directed a series of shorts for the PBS show "Life360". In 2003 he directed a short segment for the Lars von Trier film The Five Obstructions. Both "Grasshopper" and "The Five Obstructions" were shown at the Sundance Film Festival in 2004.
In 2004 Sabiston was hired as Head of Animation for Richard Linklater's A Scanner Darkly. He modified the software substantially for the film. Since 2005 he has also directed the "Talk to Chuck" campaign of animated adverti
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https://en.wikipedia.org/wiki/Dynameter
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A dynameter is an instrument that measures the magnification of a telescope. It is usually a double-image micrometer used to measure the diameter of the image of the object glass. The magnifying power is found by comparing the actual diameter of the glass with the measured diameter of the image of the glass.
References
Dictionary entry for dynameter.
The DYNAMETER, archived from the original
Optical instruments
Measuring instruments
Astronomical imaging
Telescope instruments
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https://en.wikipedia.org/wiki/Solaris%20Containers
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Solaris Containers (including Solaris Zones) is an implementation of operating system-level virtualization technology for x86 and SPARC systems, first released publicly in February 2004 in build 51 beta of Solaris 10, and subsequently in the first full release of Solaris 10, 2005. It is present in illumos (formerly OpenSolaris) distributions, such as OpenIndiana, SmartOS, Tribblix and OmniOS, as well as in the official Oracle Solaris 11 release.
A Solaris Container is the combination of system resource controls and the boundary separation provided by zones. Zones act as completely isolated virtual servers within a single operating system instance. By consolidating multiple sets of application services onto one system and by placing each into isolated virtual server containers, system administrators can reduce cost and provide most of the same protections of separate machines on a single machine.
Terminology
The name of this technology changed during development and the pre-launch public events. Before the launch of Solaris Zones in 2005, a Solaris Container was any type of workload constrained by Solaris resource management features. The latter had been a separate software package in earlier history. By 2007 the term Solaris Containers came to mean a Solaris Zone combined with resource management controls.
Later, there was a gradual move such that Solaris Containers specifically referred to non-global zones, with or without additional Resource Management. Zones hosted by a global zone are known as "non-global zones" but are sometimes just called "zones". The term "local zone" is specifically discouraged, since in this usage "local" is not an antonym of "global". The global zone has visibility of all resource on the system, whether these are associated with the global zone or a non-global zone. Unless otherwise noted, "zone" will refer to non-global zones in this article.
To simplify terminology, Oracle dropped the use of the term Container in Solaris 11, and has
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https://en.wikipedia.org/wiki/DNA%20supercoil
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DNA supercoiling refers to the amount of twist in a particular DNA strand, which determines the amount of strain on it. A given strand may be "positively supercoiled" or "negatively supercoiled" (more or less tightly wound). The amount of a strand’s supercoiling affects a number of biological processes, such as compacting DNA and regulating access to the genetic code (which strongly affects DNA metabolism and possibly gene expression). Certain enzymes, such as topoisomerases, change the amount of DNA supercoiling to facilitate functions such as DNA replication and transcription. The amount of supercoiling in a given strand is described by a mathematical formula that compares it to a reference state known as "relaxed B-form" DNA.
Overview
In a "relaxed" double-helical segment of B-DNA, the two strands twist around the helical axis once every 10.4–10.5 base pairs of sequence. Adding or subtracting twists, as some enzymes do, imposes strain. If a DNA segment under twist strain is closed into a circle by joining its two ends, and then allowed to move freely, it takes on different shape, such as a figure-eight. This shape is referred to as a supercoil. (The noun form "supercoil" is often used when describing DNA topology.)
The DNA of most organisms is usually negatively supercoiled. It becomes temporarily positively supercoiled when it is being replicated or transcribed. These processes are inhibited (regulated) if it is not promptly relaxed. The simplest shape of a supercoil is a figure eight; a circular DNA strand assumes this shape to accommodate more or few helical twists. The two lobes of the figure eight will appear rotated either clockwise or counterclockwise with respect to one another, depending on whether the helix is over- or underwound. For each additional helical twist being accommodated, the lobes will show one more rotation about their axis.
Lobal contortions of a circular DNA, such as the rotation of the figure-eight lobes above, are referred to as
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https://en.wikipedia.org/wiki/List%20of%20DVD%20manufacturers
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This aims to be a complete list of DVD manufacturers.
This list may not be complete or up to date. If you see a manufacturer that should be here but isn't (or one that shouldn't be here but is), please update the page accordingly. This list is only a list of brand names for DVDs and not an actual
manufacturers list.
A
Aiwa
Akai
Alba
Amazon
Amstrad
Apex Digital
Apple
ACCURA
Acme
Acer
Allied Electronics Pte Limited
Asus
B
Bang & Olufsen
BenQ
Bose
Bush
Beyond
C
CMC Magnetics
Citizen Electronics Co., Ltd.
Craig Electronics
Curtis International Ltd.
D
Daewoo Electronics
Denon
Dell
E
Emerson
F
Facebook
Funai
Fukuda
G
GE
Google
Go Electronics
Grundig
H
Harman/kardon
Hitachi
Hewlett-Packard
I
Imation
J
Jodie
JVC
K
KDS
L
Lenovo
LG
LiteOn
Loewe
M
Magnavox
Marantz
Maxell
Medion
Memorex
Microsoft Windows
Mitsubishi Electric
Moser Baer
Mustek Systems, Inc.
N
NEC
O
Onn
Oppo
Orion Electric
P
Panasonic
Philips
Pioneer
ProScan
Pressing-Media
R
RCA
Ritek
Ricoh
S
Samsung
Sanyo
Sharp
Sony
Sylvania
Symphonic
SM Pictures
T
Teac
Technics
Technika
Thomson
Toshiba
U
V
Verbatim Corporation
W
Weltec
Y
Yamaha
Z
Zenith
See also
DVD
References
Computing-related lists
Technology-related lists
DVD
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https://en.wikipedia.org/wiki/Cavity%20wall
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A cavity wall is a type of wall that has a hollow center. They can be described as consisting of two "skins" separated by a hollow space (cavity). The skins typically are masonry, such as brick or cinder block. Masonry is an absorbent material that can slowly draw rainwater or even humidity into the wall. One function of the cavity is to drain water through weep holes at the base of the wall system or above windows. The weep holes allow wind to create an air stream through the cavity that exports evaporated water from the cavity to the outside. Usually, weep holes are created by separating several vertical joints approximately two meters apart at the base of each story. Weep holes are also placed above windows to prevent dry rot of wooden window frames. A cavity wall with masonry as both inner and outer skins is more commonly referred to as a double wythe masonry wall.
History
Cavity wall construction was introduced in the United Kingdom during the 19th century and gained widespread use in the 1920s. In some early examples, stones were used to tie the two skins together, while in the 20th century metal ties came into use. Initially cavity widths were narrow and were primarily implemented to reduce the passage of moisture into the interior of the building. The introduction of insulation into the cavity became standard in the 1970s and compulsory in the 1990s.
Advantages
Resist wind driven rain
Insulation provided by slow moving air films and airgap
Enables use of low cost nonrigid insulation batts
Tie types
A tie in a cavity wall is a used to secure the internal and external walls (or leaves)—constructed of bricks or cement blocks. They can be made from:
Stone
Brick
Iron - prone to rusting & expanding
Stainless steel
Plastic
Elastic
Components
A cavity wall is composed of two masonry walls separated by an air space. The outer wall is made of brick and faces the outside of the building structure. The inner wall may be constructed of masonry units such as
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https://en.wikipedia.org/wiki/Windows%20DNA
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Windows DNA, short for Windows Distributed interNet Applications Architecture, is a marketing name for a collection of Microsoft technologies that enable the Windows platform and the Internet to work together. Some of the principal technologies that DNA comprises are ActiveX, Dynamic HTML (DHTML) and COM. Windows DNA has been largely superseded by the Microsoft .NET Framework, and Microsoft no longer uses the term. To support web-based applications, Microsoft has tried to add Internet features into the operating system using COM. However, developing a web-based application using COM-based Windows DNA is quite complex, because Windows DNA requires the use of numerous technologies and languages.
These technologies are completely unrelated from a syntactic point of view.
External links
Unraveling Windows DNA at MSDN
Windows DNA at Smart Computing Encyclopedia
Microsoft's DNA Web page in 1999
Windows communication and services
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https://en.wikipedia.org/wiki/Device%20under%20test
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A device under test (DUT), also known as equipment under test (EUT) and unit under test (UUT), is a manufactured product undergoing testing, either at first manufacture or later during its life cycle as part of ongoing functional testing and calibration checks. This can include a test after repair to establish that the product is performing in accordance with the original product specification.
Electronics testing
In the electronics industry a DUT is any electronic assembly under test. For example, cell phones coming off of an assembly line may be given a final test in the same way as the individual chips were earlier tested. Each cell phone under test is, briefly, the DUT.
For circuit boards, the DUT is often connected to the test equipment using a bed of nails tester of pogo pins.
Semiconductor testing
In semiconductor testing, the device under test is a die on a wafer or the resulting packaged part. A connection system is used, connecting the part to automatic or manual test equipment. The test equipment then applies power to the part, supplies stimulus signals, then measures and evaluates the resulting outputs from the device. In this way, the tester determines whether the particular device under test meets the device specifications.
While packaged as a wafer, automatic test equipment (ATE) can connect to the individual units using a set of microscopic needles. Once the chips are sawn apart and packaged, test equipment can connect to the chips using ZIF sockets (sometimes called contactors).
See also
Automatic test equipment
DUT board
Product testing
System under test
Test bench
References
Semiconductor device fabrication
Electronic engineering
Hardware testing
Product testing
Automatic test equipment
Environmental testing
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https://en.wikipedia.org/wiki/Drinker%20paradox
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The drinker paradox (also known as the drinker's theorem, the drinker's principle, or the drinking principle) is a theorem of classical predicate logic that can be stated as "There is someone in the pub such that, if he or she is drinking, then everyone in the pub is drinking." It was popularised by the mathematical logician Raymond Smullyan, who called it the "drinking principle" in his 1978 book What Is the Name of this Book?
The apparently paradoxical nature of the statement comes from the way it is usually stated in natural language. It seems counterintuitive both that there could be a person who is causing the others to drink, or that there could be a person such that all through the night that one person were always the last to drink. The first objection comes from confusing formal "if then" statements with causation (see Correlation does not imply causation or Relevance logic for logics that demand relevant relationships between premise and consequent, unlike classical logic assumed here). The formal statement of the theorem is timeless, eliminating the second objection because the person the statement holds true for at one instant is not necessarily the same person it holds true for at any other instant.
The formal statement of the theorem is
where D is an arbitrary predicate and P is an arbitrary nonempty set.
Proofs
The proof begins by recognizing it is true that either everyone in the pub is drinking, or at least one person in the pub is not drinking. Consequently, there are two cases to consider:
Suppose everyone is drinking. For any particular person, it cannot be wrong to say that if that particular person is drinking, then everyone in the pub is drinking—because everyone is drinking. Because everyone is drinking, then that one person must drink because when that person drinks everybody drinks, everybody includes that person.
Otherwise at least one person is not drinking. For any nondrinking person, the statement if that particular person is dr
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https://en.wikipedia.org/wiki/Positioning%20system
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A positioning system is a system for determining the position of an object in space. One of the most well-known and commonly used positioning systems is the Global Positioning System (GPS).
Positioning system technologies exist ranging from worldwide coverage with meter accuracy to workspace coverage with sub-millimeter accuracy.
Coverage
Interplanetary systems
Interplanetary-radio communication systems not only communicate with spacecraft, but they are also used to determine their position. Radar can track targets near the Earth, but spacecraft in deep space must have a working transponder on board to echo a radio signal back. Orientation information can be obtained using star trackers.
Global systems
Global navigation satellite systems (GNSS) allow specialized radio receivers to determine their 3-D space position, as well as time, with an accuracy of 2–20 metres or tens of nanoseconds. Currently deployed systems use microwave signals that can only be received reliably outdoors and that cover most of Earth's surface, as well as near-Earth space.
The existing and planned systems are:
Global Positioning System – US military system, fully operational since 1995
GLONASS – Russian military system, fully operational since October 2011
Galileo – European Community, fully operational since December 2019
Beidou navigation system – China, fully operational since June 2020
Indian Regional Navigation Satellite System – a planned project in India
Regional systems
Networks of land-based positioning transmitters allow specialized radio receivers to determine their 2-D position on the surface of the Earth. They are generally less accurate than GNSS because their signals are not entirely restricted to line-of-sight propagation, and they have only regional coverage. However, they remain useful for special purposes and as a backup where their signals are more reliably received, including underground and indoors, and receivers can be built that consume very low battery powe
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https://en.wikipedia.org/wiki/Darwin%20%28unit%29
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The darwin (d) is a unit of evolutionary change, defined by J. B. S. Haldane in 1949. One darwin is defined to be an e-fold (about 2.718) change in a trait over one million years. Haldane named the unit after Charles Darwin.
Equation
The equation for calculating evolutionary change in darwins () is:
where and are the initial and final values of the trait and is the change in time in millions of years. An alternative form of this equation is:
Since the difference between two natural logarithms is a dimensionless ratio, the trait may be measured in any unit. Inexplicably, Haldane defined the millidarwin as 10−9 darwins, despite the fact that the prefix milli- usually denotes a factor of one thousandth (10−3).
Application
The measure is most useful in palaeontology, where macroevolutionary changes in the dimensions of fossils can be compared. Where this is used it is an indirect measure as it relies on phenotypic rather than genotypic data. Several data points are required to overcome natural variation within a population. The darwin only measures the evolution of a particular trait rather than a lineage; different traits may evolve at different rates within a lineage. The evolution of traits can however be used to infer as a proxy the evolution of lineages.
See also
Evolutionary biology
Macroevolution
Microevolution
References
Evolutionary biology
Rate of evolution
Units of level
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https://en.wikipedia.org/wiki/Spam%20Cube
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Spam Cube, Inc was a high-tech startup company based in the midtown area of New York City. The company invented and manufactured the Spam Cube, a SaaS (Security As A Service) network security hardware device for consumers that blocked spam e-mail, computer viruses and phishing. The company invented a SaaS delivery platform technology that enables any home networking embedded device such as a Broadband cable modem, DSL modem, Wireless router or Femtocell to offer network Security As A Service technology that blocks spam e-mail, computer viruses and phishing. The Spam Cube SaaS platform gave the consumer the choice to select spam e-mail, computer viruses, and phishing blocking technology that was powered by either McAfee or Symantec managed enterprise Security As A Service technology.
Trademark Issues
In May 2006, the company ran into a costly legal battle with Hormel Foods over its trademark "Spam Cube". Hormel Foods claimed that the company's "Spam Cube" brand name was causing confusion amongst consumers and that consumers were not able to tell the difference between the Spam Cube, a cube-shaped home network security device, and Hormel's cube-shaped SPAM canned meat product. In February 2008, the company won the legal battle against Hormel Foods in the United States. The SPAM trademark dispute was widely publicized since the dispute would have forced the company into bankruptcy had Hormel Foods won.
Competitors
Three years after Spam Cube released its technology, Cisco Systems teamed up with Trend Micro to manufacture the Linksys Home Network Defender. Linksys and Trend Micro competed directly with Spam Cube for market share in the embedded device SaaS market.
See also
Anti-spam appliances
References
External links
Spam Cube, Inc | Home Page
PC World - Spam Slayer: Don't Can Spam, Cube It
New York Times - On the Job, A Spam Fighter Is Learning
Picture of Spam Cube article on the front page of the March 30 edition of the New York Times
NY1 interview with Da
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https://en.wikipedia.org/wiki/CPU%20multiplier
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In computing, the clock multiplier (or CPU multiplier or bus/core ratio) sets the ratio of an internal CPU clock rate to the externally supplied clock. A CPU with a 10x multiplier will thus see 10 internal cycles (produced by PLL-based frequency multiplier circuitry) for every external clock cycle. For example, a system with an external clock of 100 MHz and a 36x clock multiplier will have an internal CPU clock of 3.6 GHz. The external address and data buses of the CPU (often collectively termed front side bus (FSB) in PC contexts) also use the external clock as a fundamental timing base; however, they could also employ a (small) multiple of this base frequency (typically two or four) to transfer data faster.
The internal frequency of microprocessors is usually based on FSB frequency. To calculate internal frequency the CPU multiplies bus frequency by a number called the clock multiplier. For calculation, the CPU uses actual bus frequency, and not effective bus frequency. To determine the actual bus frequency for processors that use dual-data rate (DDR) buses (AMD Athlon and Duron) and quad-data rate buses (all Intel microprocessors starting from Pentium 4) the effective bus speed should be divided by 2 for AMD or 4 for Intel.
Clock multipliers on many modern processors are fixed; it is usually not possible to change them. Some versions of processors have clock multipliers unlocked; that is, they can be "overclocked" by increasing the clock multiplier setting in the motherboard's BIOS setup program. Some CPU engineering samples may also have the clock multiplier unlocked. Many Intel qualification samples have maximum clock multiplier locked: these CPUs may be underclocked (run at lower frequency), but they cannot be overclocked by increasing clock multiplier higher than intended by CPU design. While these qualification samples and majority of production microprocessors cannot be overclocked by increasing their clock multiplier, they still can be overclocked by
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https://en.wikipedia.org/wiki/Outline%20of%20computer%20vision
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The following outline is provided as an overview of and topical guide to computer vision:
Computer vision – interdisciplinary field that deals with how computers can be made to gain high-level understanding from digital images or videos. From the perspective of engineering, it seeks to automate tasks that the human visual system can do. Computer vision tasks include methods for acquiring digital images (through image sensors), image processing, and image analysis, to reach an understanding of digital images. In general, it deals with the extraction of high-dimensional data from the real world in order to produce numerical or symbolic information that the computer can interpret. The image data can take many forms, such as video sequences, views from multiple cameras, or multi-dimensional data from a medical scanner. As a technological discipline, computer vision seeks to apply its theories and models for the construction of computer vision systems. As a scientific discipline, computer vision is concerned with the theory behind artificial systems that extract information from images.
Branches of computer vision
Computer stereo vision
Underwater computer vision
History of computer vision
History of computer vision
Computer vision subsystems
Image enhancement
Image denoising
Image histogram
Inpainting
Super-resolution imaging
Histogram equalization
Tone mapping
Retinex
Gamma correction
Anisotropic diffusion (Perona–Malik equation)
Transformations
Affine transform
Homography (computer vision)
Hough transform
Radon transform
Walsh–Hadamard transform
Filtering, Fourier and wavelet transforms and image compression
Image compression
Filter bank
Gabor filter
JPEG 2000
Adaptive filtering
Color vision
Visual perception
Human visual system model
Color matching function
Color space
Color appearance model
Color management system
Color mapping
Color model
Color profile
Feature extraction
Active contour
Blob detection
Canny edge det
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https://en.wikipedia.org/wiki/Design%20Criteria%20Standard%20for%20Electronic%20Records%20Management%20Software%20Applications
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United States Department of Defense standard 5015.2-STD, the Design Criteria Standard for Electronic Records Management Software Applications, was implemented in June 2002. This standard defines requirements for the management of records within the Department of Defense, which has become the accepted standard for many state, county, and local governments.
The standard was developed in 1996 by a team led by Kenneth Thibodeau of the National Archives and Records Administration.
, only three companies are certified for records management at all levels for the Department of Defense: HP Enterprise (American), Feith Systems and Software (American), and Open Text (Canadian).
The following additional companies have some level of certification: IBM Corporation, Oracle USA, Gimmal LLC, EMC, Newgen Software, ZL Technologies, Perceptive, Laserfiche, Alfresco, Collabware, and Northrop Grumman.
See also
Records management
Digital curation
Archives
References
External links
5015.2-STD
United States Department of Defense standards
Records management
Information governance
2002 introductions
Email
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https://en.wikipedia.org/wiki/Actinides%20in%20the%20environment
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Environmental radioactivity is not limited to actinides; non-actinides such as radon and radium are of note. While all actinides are radioactive, there are a lot of actinides or actinide-relating minerals in the Earth's crust such as uranium and thorium. These minerals are helpful in many ways, such as carbon-dating, most detectors, X-rays, and more.
Inhalation versus ingestion
Generally, ingested insoluble actinide compounds, such as high-fired uranium dioxide and mixed oxide (MOX) fuel, will pass through the digestive system with little effect since they cannot dissolve and be absorbed by the body. Inhaled actinide compounds, however, will be more damaging as they remain in the lungs and irradiate the lung tissue.
Ingested low-fired oxides and soluble salts such as nitrate can be absorbed into the blood stream. If they are inhaled then it is possible for the solid to dissolve and leave the lungs. Hence, the dose to the lungs will be lower for the soluble form.
Actinium
Actinium can be naturally found in traces in uranium ore as 227Ac, an α and β emitter with half-life 21.773 years. Uranium ore contains about 0.2 mg of actinium per ton of uranium. It is more commonly made in milligram amounts by neutron irradiation of 226Ra in a nuclear reactor. Natural actinium almost exclusively consists of one isotope, 227Ac, with only minute traces of other shorter-lived isotopes (225Ac and 228Ac) occurring in other decay chains.
Thorium
In India, a large amount of thorium ore can be found in the form of monazite in placer deposits of the Western and Eastern coastal dune sands, particularly in the Tamil Nadu coastal areas. The residents of this area are exposed to a naturally occurring radiation dose ten times higher than the worldwide average.
Occurrence
Thorium is found at low levels in most rocks and soils, where it is about three times more abundant than uranium and about as abundant as lead. On average, soil commonly contains approximately 6 parts per million (ppm
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https://en.wikipedia.org/wiki/Metatheorem
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In logic, a metatheorem is a statement about a formal system proven in a metalanguage. Unlike theorems proved within a given formal system, a metatheorem is proved within a metatheory, and may reference concepts that are present in the metatheory but not the object theory.
A formal system is determined by a formal language and a deductive system (axioms and rules of inference). The formal system can be used to prove particular sentences of the formal language with that system. Metatheorems, however, are proved externally to the system in question, in its metatheory. Common metatheories used in logic are set theory (especially in model theory) and primitive recursive arithmetic (especially in proof theory). Rather than demonstrating particular sentences to be provable, metatheorems may show that each of a broad class of sentences can be proved, or show that certain sentences cannot be proved.
Examples
Examples of metatheorems include:
The deduction theorem for first-order logic says that a sentence of the form φ→ψ is provable from a set of axioms A if and only if the sentence ψ is provable from the system whose axioms consist of φ and all the axioms of A.
The class existence theorem of von Neumann–Bernays–Gödel set theory states that for every formula whose quantifiers range only over sets, there is a class consisting of the sets satisfying the formula.
Consistency proofs of systems such as Peano arithmetic.
See also
Metamathematics
Use–mention distinction
References
Geoffrey Hunter (1969), Metalogic.
Alasdair Urquhart (2002), "Metatheory", A companion to philosophical logic, Dale Jacquette (ed.), p. 307
External links
Meta-theorem at Encyclopaedia of Mathematics
Metalogic
Mathematical terminology
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https://en.wikipedia.org/wiki/Lamella%20%28cell%20biology%29
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A lamella (: lamellae) in biology refers to a thin layer, membrane or plate of tissue. This is a very broad definition, and can refer to many different structures. Any thin layer of organic tissue can be called a lamella and there is a wide array of functions an individual layer can serve. For example, an intercellular lipid lamella is formed when lamellar disks fuse to form a lamellar sheet. It is believed that these disks are formed from vesicles, giving the lamellar sheet a lipid bilayer that plays a role in water diffusion.
Another instance of cellular lamellae can be seen in chloroplasts. Thylakoid membranes are actually a system of lamellar membranes working together, and are differentiated into different lamellar domains. This lamellar system allows plants to convert light energy into chemical energy. Chloroplasts are characterized by a system of membranes embedded in a hydrophobic proteinaceous matrix, or stroma. The basic unit of the membrane system is a flattened single vesicle called the thylakoid; thylakoids stack into grana. All the thylakoids of a granum are connected with each other, and the grana are connected by intergranal lamellae.
It is placed between the two primary cell walls of two plant cells and made up of intracellular matrix. The lamella comprises a mixture of polygalacturons (D-galacturonic acid) and neutral carbohydrates. It is soluble in the pectinase enzyme.
Lamella, in cell biology, is also used to describe the leading edge of a motile cell, of which the lamellipodia is the most forward portion.
The lipid bilayer core of biological membranes is also called lamellar phase. Thus, each bilayer of multilamellar liposomes and wall of a unilamellar liposome is also referred to as a lamella.
See also
Middle lamella
Thylakoid
Lipid bilayer
References
Further reading
Cell biology
Photosynthesis
Prokaryotic cell anatomy
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https://en.wikipedia.org/wiki/Immunocytochemistry
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Immunocytochemistry (ICC) is a common laboratory technique that is used to anatomically visualize the localization of a specific protein or antigen in cells by use of a specific primary antibody that binds to it. The primary antibody allows visualization of the protein under a fluorescence microscope when it is bound by a secondary antibody that has a conjugated fluorophore. ICC allows researchers to evaluate whether or not cells in a particular sample express the antigen in question. In cases where an immunopositive signal is found, ICC also allows researchers to determine which sub-cellular compartments are expressing the antigen.
Immunocytochemistry vs. immunohistochemistry
Immunocytochemistry differs from immunohistochemistry in that the former is performed on samples of intact cells that have had most, if not all, of their surrounding extracellular matrix removed. This includes individual cells that have been isolated from a block of solid tissue, cells grown within a culture, cells deposited from suspension, or cells taken from a smear. In contrast, immunohistochemical samples are sections of biological tissue, where each cell is surrounded by tissue architecture and other cells normally found in the intact tissue.
Immunocytochemistry is a technique used to assess the presence of a specific protein or antigen in cells (cultured cells, cell suspensions) by use of a specific antibody, which binds to it, thereby allowing visualization and examination under a microscope. It is a valuable tool for the determination of cellular contents from individual cells. Samples that can be analyzed include blood smears, aspirates, swabs, cultured cells, and cell suspensions.
There are many ways to prepare cell samples for immunocytochemical analysis. Each method has its own strengths and unique characteristics so the right method can be chosen for the desired sample and outcome.
Cells to be stained can be attached to a solid support to allow easy handling in subsequent proc
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https://en.wikipedia.org/wiki/Panama%20Canal%20fence
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The Panama Canal fence was a separation barrier built by the United States in the Panama Canal Zone that divided the Republic of Panama into two separate sections. The Canal Zone, primarily consisting of the Panama Canal, was a strip of land running from the Pacific Ocean to the Caribbean. The fence, also called “Fence of Shame” and "another Berlin Wall” portrayed the centre of geopolitical and diplomatic turmoil between the United States and the Republic of Panama. Some evidences suggest construction, breaking and repairs of the fence while others including many aerial photographs and Life magazine (January 24, 1964) confirm that there was no such physical barrier between the Canal Zone and Panama.
Background
Panama gained independence from Colombia with the assistance of the United States and was recognized as a separate state in 1903. Diplomatic relations were established on November 13, 1903 between the United States and Panama. Both countries signed the Hay-Bunau-Varilla treaty. The treaty provided the United States with sovereignty over the Canal Zone. In exchange, the Republic of Panama received a $10 million payment and additional annual payments which began with the opening of the canal. In addition to this purchase from Panama, the United States bought the title to all lands in the Canal Zone, including a payment of $40 million to the French Canal Company for their properties.
Amid much resentment among Panamanians, the treaty granted the Canal Zone, a strip 5 miles (8.0 km) wide on each side of the Panama Canal, in perpetuity to the United States to build, manage, strengthen and defend an inter-oceanic canal. The Canal Zone which became a U.S. territory and had its own police, post offices, courts, television and radio stations.
The Panama Canal fence, dubbed as “Fence of Shame” and "The other Berlin Wall”. was the demarcation line between the Canal Zone and Republic of Panama.
Construction
Due to lack of evidence in the knowledge base, the dimensi
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https://en.wikipedia.org/wiki/Camera%20interface
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The Camera Interface block or CAMIF is the hardware block that interfaces with different image sensor interfaces and provides a standard output that can be used for subsequent image processing.
A typical Camera Interface would support at least a parallel interface although these days many camera interfaces are beginning to support the Mobile Industry Processor Interface (MIPI) Camera Serial Interface (CSI) interface.
Electrical connections
The camera interface's parallel interface consists of the following lines:
8 to 12 bits parallel data line
These are parallel data lines that carry pixel data. The data transmitted on these lines change with every Pixel Clock (PCLK).
Horizontal Sync (HSYNC)
This is a special signal that goes from the camera sensor or ISP to the camera interface. An HSYNC indicates that one line of the frame is transmitted.
Vertical Sync (VSYNC)
This signal is transmitted after the entire frame is transferred. This signal is often a way to indicate that one entire frame is transmitted.
Pixel Clock (PCLK)
This is the pixel clock and it would change on every pixel.
NOTE: The above lines are all treated as input lines to the Camera Interface hardware.
See also
Digital camera
Digital photography
Demosaicing
Digital image processing
Camera Serial Interface (CSI)
References
Image processing
MIPI Alliance standards
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https://en.wikipedia.org/wiki/Chuck%20Yeager%27s%20Advanced%20Flight%20Trainer
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Chuck Yeager's Advanced Flight Trainer is an aircraft simulation computer game published by Electronic Arts in 1987. It was originally released as Chuck Yeager's Advanced Flight Simulator. Due to a legal dispute with Microsoft over the term "Flight Simulator", the game was pulled from shelves and renamed. Many copies of the original version were sold prior to this. Chuck Yeager served as technical consultant for the game, where his likeness and voice were prominently used.
The game allows a player to "test pilot" 14 different airplanes, including the Bell X-1, which Yeager had piloted to become the first man to exceed Mach 1.
The game is embellished by Yeager's laconic commentary: When the user crashes one plane, Yeager remarks "You sure bought the farm on that one", or other asides.
Aircraft
Chuck Yeager's Advanced Flight Trainer includes 11 real aircraft and three experimental aircraft designed by the developers. The fictional experimental aircraft were named after people who worked on the game.
Real aircraft
Bell X-1
Cessna 172
Douglas X-3 Stiletto
General Dynamics F-16 Fighting Falcon
Lockheed SR-71 Blackbird
McDonnell Douglas F/A-18 Hornet
North American P-51 Mustang
Piper PA-28 Cherokee
Sopwith Camel
SPAD S.XIII
Supermarine Spitfire
Experimental aircraft
Grace Industries XPG-12 Samurai
Hilleman Ltd. XRH4 MadDog
Lerner Aeronautics XNL-16 Instigator
Reception
The game was a big hit for EA, selling 100,000 copies by December 1987. In May 1988, it was awarded a "Platinum" certification from the Software Publishers Association for sales above 250,000 units. Game reviewers Hartley and Patricia Lesser complimented the game in their "The Role of Computers" column in Dragon #126 (1987), giving PC/MS-DOS version of the game 4 out of 5 stars. The Lessers reviewed the Macintosh version of the game in 1988 in Dragon #140 in "The Role of Computers" column, giving that version 4 stars as well. Compute! criticized the blocky graphics and sound, but noted that the simple g
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https://en.wikipedia.org/wiki/Heteroclinic%20cycle
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In mathematics, a heteroclinic cycle is an invariant set in the phase space of a dynamical system. It is a topological circle of equilibrium points and connecting heteroclinic orbits. If a heteroclinic cycle is asymptotically stable, approaching trajectories spend longer and longer periods of time in a neighbourhood of successive equilibria.
In generic dynamical systems heteroclinic connections are of high co-dimension, that is, they will not persist if parameters are varied.
Robust heteroclinic cycles
A robust heteroclinic cycle is one which persists under small changes in the underlying dynamical system. Robust cycles often arise in the presence of symmetry or other constraints which force the existence of invariant hyperplanes. A prototypical example of a robust heteroclinic cycle is the Guckenheimer–Holmes cycle. This cycle has also been studied in the context of rotating convection, and as three competing species in population dynamics.
See also
Heteroclinic bifurcation
Heteroclinic network
References
Guckenheimer J and Holmes, P, 1988, Structurally Stable Heteroclinic Cycles, Math. Proc. Cam. Phil. Soc. 103: 189-192.
F. M. Busse and K. E. Heikes (1980), Convection in a rotating layer: A simple case of turbulence, Science, 208, 173–175.
R. May and W. Leonard (1975), Nonlinear aspects of competition between three species, SIAM J. Appl. Math., 29, 243–253.
External links
Dynamical systems
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https://en.wikipedia.org/wiki/Food%20biodiversity
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Food biodiversity is defined as "the diversity of plants, animals and other organisms used for food, covering the genetic resources within species, between species and provided by ecosystems."
Food biodiversity can be considered from two main perspectives: production and consumption. From a consumption perspective, food biodiversity describes the diversity of foods in human diets and their contribution to dietary diversity, cultural identity and good nutrition. Production of food biodiversity looks at the thousands of food products, such as fruits, nuts, vegetables, meat and condiments sourced from agriculture and from the wild (e.g. forests, uncultivated fields, water bodies). Food biodiversity covers the diversity between species, for example different animal and crop species, including those considered neglected and underutilized species. Food biodiversity also comprises the diversity within species, for example different varieties of fruit and vegetables, or different breeds of animals.
Food diversity, diet diversity nutritional diversity, are also terms used in the new diet culture spawned by Brandon Eisler, in the study known as Nutritional Diversity.
Consumption of food biodiversity
Food biodiversity, nutrition, and health
Promoting diversity of foods and species consumed in human diets in particular has potential co-benefits for public health as well as sustainable food systems perspective.
Food biodiversity provides necessary nutrients for quality diets and is an essential part of local food systems, cultures and food security. Promoting diversity of foods and species consumed in human diets in particular has potential co-benefits for sustainable food systems. Nutritionally, diversity in food is associated with higher micronutrient adequacy of diets. On average, per additional species consumed, mean adequacy of vitamin A, vitamin C, folate, calcium, iron, and zinc increased by 3%. From a conservation point of view, diets based on a wide variety of
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https://en.wikipedia.org/wiki/Agricultural%20chemistry
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Agricultural chemistry is the study of chemistry, especially organic chemistry and biochemistry, as they relate to agriculture. This includes agricultural production, the use of ammonia in fertilizer, pesticides, and how plant biochemistry can be used to genetically alter crops. Agricultural chemistry is not a distinct discipline, but a common thread that ties together genetics, physiology, microbiology, entomology, and numerous other sciences that impinge on agriculture.
Agricultural chemistry studies the chemical compositions and reactions involved in the production, protection, and use of crops and livestock. Its applied science and technology aspects are directed towards increasing yields and improving quality, which comes with multiple advantages and disadvantages.
Advantages and Disadvantages
The goals of agricultural chemistry are to expand understanding of the causes and effects of biochemical reactions related to plant and animal growth, to reveal opportunities for controlling those reactions, and to develop chemical products that will provide the desired assistance or control. Agricultural chemistry is therefore used in processing of raw products into foods and beverages, as well as environmental monitoring and remediation. It is also used to make feed supplements for animals, as well as medicinal compounds for the prevention or control of disease. When agriculture is considered with ecology, the sustainablility of an operation is considered.
However, modern agrochemical industry has gained a reputation for its maximising profits while violating sustainable and ecologically viable agricultural principles. Eutrophication, the prevalence of genetically modified crops and the increasing concentration of chemicals in the food chain (e.g. persistent organic pollutants) are only a few consequences of naive industrial agriculture.
Soil Chemistry
Agricultural chemistry often aims at preserving or increasing the fertility of soil, maintaining or improving the
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https://en.wikipedia.org/wiki/International%20Day%20for%20Biological%20Diversity
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The International Day for Biological Diversity (or World Biodiversity Day) is a United Nations–sanctioned international day for the promotion of biodiversity issues. It is currently held on May 22.
The International Day for Biological Diversity falls within the scope of the UN Post-2015 Development Agenda's Sustainable Development Goals. In this larger initiative of international cooperation, the topic of biodiversity concerns stakeholders in sustainable agriculture; desertification, land degradation and drought; water and sanitation; health and sustainable development; energy; science, technology and innovation, knowledge-sharing and capacity-building; urban resilience and adaptation; sustainable transport; climate change and disaster risk reduction; oceans and seas; forests; vulnerable groups including indigenous peoples; and food security. The critical role of biodiversity in sustainable development was recognized in a Rio+20 outcome document, "The World We Want: A Future for All".
From its creation by the Second Committee of the UN General Assembly in 1993 until 2000, it was held on December 29 to celebrate the day the Convention on Biological Diversity went into effect. On December 20, 2000, the date was shifted to commemorate the adoption of the Convention on May 22, 1992, at the Rio de Janeiro Earth Summit, and partly to avoid the many other holidays that occur in late December.
Theme
See also
United Nations Decade on Biodiversity (2011–2020)
International Year of Biodiversity (2010)
References
External links
Post-2015 Development Agenda
Considering Man's Place in the World," May 22, 2014
Sustainable Development Goals
"The World We Want: A Future for All"
Biodiversity
Convention on Biological Diversity
Biological
May observances
Recurring events established in 1993
Biological Diversity, International Day for
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https://en.wikipedia.org/wiki/242%20%28number%29
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242 (two hundred [and] forty-two) is the natural number following 241 and preceding 243.
242 is the smallest integer to start a run of four consecutive integers with the same number of divisors.
242 is a nontotient since there is no integer with 242 coprimes below it.
242 is a palindrome.
242 is the number of parallelogram polyominoes with 8 cells.
References
Integers
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https://en.wikipedia.org/wiki/Goursat%27s%20lemma
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Goursat's lemma, named after the French mathematician Édouard Goursat, is an algebraic theorem about subgroups of the direct product of two groups.
It can be stated more generally in a Goursat variety (and consequently it also holds in any Maltsev variety), from which one recovers a more general version of Zassenhaus' butterfly lemma. In this form, Goursat's theorem also implies the snake lemma.
Groups
Goursat's lemma for groups can be stated as follows.
Let , be groups, and let be a subgroup of such that the two projections and are surjective (i.e., is a subdirect product of and ). Let be the kernel of and the kernel of . One can identify as a normal subgroup of , and as a normal subgroup of . Then the image of in is the graph of an isomorphism . One then obtains a bijection between :
Subgroups of which project onto both factors,
Triples with normal in , normal in and isomorphism of onto .
An immediate consequence of this is that the subdirect product of two groups can be described as a fiber product and vice versa.
Notice that if is any subgroup of (the projections and need not be surjective), then the projections from onto and are surjective. Then one can apply Goursat's lemma to .
To motivate the proof, consider the slice in , for any arbitrary . By the surjectivity of the projection map to , this has a non trivial intersection with . Then essentially, this intersection represents exactly one particular coset of . Indeed, if we have elements with and , then being a group, we get that , and hence, . It follows that and lie in the same coset of . Thus the intersection of with every "horizontal" slice isomorphic to is exactly one particular coset of in .
By an identical argument, the intersection of with every "vertical" slice isomorphic to is exactly one particular coset of in .
All the cosets of are present in the group , and by the above argument, there is an exact 1:1 correspondence between them. The proof
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https://en.wikipedia.org/wiki/List%20of%20MeSH%20codes%20%28C16%29
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The following is a partial list of the "C" codes for Medical Subject Headings (MeSH), as defined by the United States National Library of Medicine (NLM).
This list continues the information at List of MeSH codes (C15). Codes following these are found at List of MeSH codes (C17). For other MeSH codes, see List of MeSH codes.
The source for this content is the set of 2006 MeSH Trees from the NLM.
– congenital, hereditary, and neonatal diseases and abnormalities
– abnormalities
– abnormalities, drug-induced
– abnormalities, multiple
– Alagille syndrome
– Angelman syndrome
– Bardet–Biedl syndrome
– basal-cell nevus syndrome
– Beckwith–Wiedemann syndrome
– Bloom syndrome
– branchio-oto-renal syndrome
– Cockayne syndrome
– cri du chat syndrome
– De Lange syndrome
– Down syndrome
– ectodermal dysplasia
– Ellis–van Creveld syndrome
– focal dermal hypoplasia
– neurocutaneous syndromes
– Gardner's syndrome
– holoprosencephaly
– incontinentia pigmenti
– Laurence–Moon syndrome
– Leopard syndrome
– Marfan syndrome
– Möbius syndrome
– nail–patella syndrome
– oculocerebrorenal syndrome
– orofaciodigital syndromes
– POEMS syndrome
– Prader–Willi syndrome
– proteus syndrome
– prune belly syndrome
– rubella syndrome, congenital
– Rubinstein–Taybi syndrome
– Short rib – polydactyly syndrome
– Smith–Lemli–Opitz syndrome
– Waardenburg syndrome
– Wolfram syndrome
– Zellweger syndrome
– abnormalities, radiation-induced
– cardiovascular abnormalities
– arterio-arterial fistula
– arteriovenous malformations
– arteriovenous fistula
– intracranial arteriovenous malformations
– central nervous system vascular malformations
– heart defects, congenital
– aortic coarctation
– arrhythmogenic right ventricular dysplasia
– cor triatriatum
– coronary vessel anomalies
– crisscross heart
– dextrocardia
– Kartagener syndrome
– ductus arteriosus, patent
– Ebstein's anomaly
– Eisenmenger complex
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https://en.wikipedia.org/wiki/List%20of%20MeSH%20codes%20%28D13%29
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The following is a partial list of the "D" codes for Medical Subject Headings (MeSH), as defined by the United States National Library of Medicine (NLM).
This list continues the information at List of MeSH codes (D12.776). Codes following these are found at List of MeSH codes (D20). For other MeSH codes, see List of MeSH codes.
The source for this content is the set of 2006 MeSH Trees from the NLM.
– nucleic acids, nucleotides, and nucleosides
– antisense elements (genetics)
– DNA, antisense
– oligodeoxyribonucleotides, antisense
– oligonucleotides, antisense
– oligodeoxyribonucleotides, antisense
– oligoribonucleotides, antisense
– rna, antisense
– micrornas
– oligoribonucleotides, antisense
– rna, small interfering
– nucleic acid precursors
– rna precursors
– nucleic acids
– DNA
– DNA adducts
– DNA, a-form
– DNA, algal
– DNA, antisense
– oligodeoxyribonucleotides, antisense
– DNA, archaeal
– DNA, bacterial
– DNA, c-form
– DNA, catalytic
– DNA, circular
– DNA, catenated
– DNA, chloroplast
– DNA, mitochondrial
– DNA, kinetoplast
– DNA, superhelical
– DNA, concatenated
– DNA, cruciform
– DNA, fungal
– DNA, helminth
– DNA, intergenic
– DNA, ribosomal spacer
– DNA, neoplasm
– DNA, plant
– DNA, chloroplast
– DNA, protozoan
– DNA, kinetoplast
– DNA, recombinant
– DNA, ribosomal
– DNA, ribosomal spacer
– DNA, satellite
– DNA, single-stranded
– DNA, complementary
– DNA transposable elements
– DNA, viral
– DNA, z-form
– isochores
– retroelements
– nucleic acid heteroduplexes
– nucleic acid probes
– antisense elements (genetics)
– DNA, antisense
– oligodeoxyribonucleotides, antisense
– oligonucleotides, antisense
– oligodeoxyribonucleotides, antisense
– oligoribonucleotides, antisense
– rna, antisense
– oligoribonucleotides, antisense
– DNA probes
– DNA, complementary
– DNA probes, hla
– DNA probes, hpv
– oligonucleotide probes
– rna probes
– rna,
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https://en.wikipedia.org/wiki/List%20of%20MeSH%20codes%20%28G14%29
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The following is a partial list of the "G" codes for Medical Subject Headings (MeSH), as defined by the United States National Library of Medicine (NLM).
This list continues the information at List of MeSH codes (G13). Codes following these are found at List of MeSH codes (H01). For other MeSH codes, see List of MeSH codes.
The source for this content is the set of 2006 MeSH Trees from the NLM.
– genetic structures
– base sequence
– at rich sequence
– gc rich sequence
– cpg islands
– matrix attachment regions
– regulatory sequences, nucleic acid
– enhancer elements (genetics)
– e-box elements
– hiv enhancer
– response elements
– serum response element
– vitamin d response element
– insulator elements
– locus control region
– operator regions (genetics)
– promoter regions (genetics)
– response elements
– serum response element
– vitamin d response element
– TATA box
– regulatory sequences, ribonucleic acid
– rna 3' polyadenylation signals
– rna splice sites
– rna 5' terminal oligopyrimidine sequence
– silencer elements, transcriptional
– terminator regions (genetics)
– repetitive sequences, nucleic acid
– interspersed repetitive sequences
– dna transposable elements
– genomic islands
– retroelements
– endogenous retroviruses
– genes, intracisternal a-particle
– long interspersed nucleotide elements
– short interspersed nucleotide elements
– alu elements
– tandem repeat sequences
– dna repeat expansion
– trinucleotide repeat expansion
– dna, satellite
– microsatellite repeats
– dinucleotide repeats
– trinucleotide repeats
– trinucleotide repeat expansion
– minisatellite repeats
– terminal repeat sequences
– hiv long terminal repeat
– hiv enhancer
– chromosome structures
– centromere
– kinetochores
– chromatids
– chromatin
– euchromatin
– heterochromatin
– sex chromatin
– nucleosomes
– nucleolus organizer region
– synaptonemal complex
– telomere
– chromosomes
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https://en.wikipedia.org/wiki/List%20of%20MeSH%20codes%20%28G05%29
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The following is a partial list of the "G" codes for Medical Subject Headings (MeSH), as defined by the United States National Library of Medicine (NLM).
This list continues the information at List of MeSH codes (G04). Codes following these are found at List of MeSH codes (G06). For other MeSH codes, see List of MeSH codes.
The source for this content is the set of 2006 MeSH Trees from the NLM.
– genetic processes
– breeding
– hybridization, genetic
– inbreeding
– consanguinity
– cell division
– cell nucleus division
– anaphase
– chromosome segregation
– nondisjunction, genetic
– meiosis
– meiotic prophase i
– chromosome pairing
– synaptonemal complex
– pachytene stage
– metaphase
– mitosis
– anaphase
– metaphase
– prometaphase
– prophase
– telophase
– prometaphase
– prophase
– meiotic prophase i
– chromosome pairing
– synaptonemal complex
– pachytene stage
– telophase
– dna damage
– chromosome breakage
– dna fragmentation
– dna methylation
– dna packaging
– chromatin assembly and disassembly
– dna repair
– sos response (genetics)
– dna replication
– dna replication timing
– s phase
– evolution
– evolution, molecular
– genetic speciation
– gene expression
– protein biosynthesis
– transcription, genetic
– reverse transcription
– gene expression regulation
– chromatin assembly and disassembly
– dosage compensation, genetic
– x chromosome inactivation
– down-regulation
– epigenesis, genetic
– epistasis, genetic
– frameshifting, ribosomal
– gene amplification
– gene expression regulation, archaeal
– gene expression regulation, bacterial
– gene expression regulation, developmental
– gene expression regulation, enzymologic
– enzyme induction
– enzyme repression
– gene expression regulation, fungal
– gene expression regulation, neoplastic
– gene expression regulation, leukemic
– gene expression regulation, plant
– gene expression regulation, viral
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https://en.wikipedia.org/wiki/Typed%20assembly%20language
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In computer science, a typed assembly language (TAL) is an assembly language that is extended to include a method of annotating the datatype of each value that is manipulated by the code. These annotations can then be used by a program (type checker) that processes the assembly language code in order to analyse how it will behave when it is executed. Specifically, such a type checker can be used to prove the type safety of code that meets the criteria of some appropriate type system.
Typed assembly languages usually include a high-level memory management system based on garbage collection.
A typed assembly language with a suitably expressive type system can be used to enable the safe execution of untrusted code without using an intermediate representation like bytecode, allowing features similar to those currently provided by virtual machine environments like Java and .NET.
See also
Proof-carrying code
Further reading
Greg Morrisett. "Typed assembly language" in Advanced Topics in Types and Programming Languages. Editor: Benjamin C. Pierce.
External links
TALx86, a research project from Cornell University which has implemented a typed assembler for the Intel IA-32 architecture.
Assembly languages
Computer security
Programming language theory
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https://en.wikipedia.org/wiki/Heptyl%20acetate
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Heptyl acetate (C9H18O2), also known as acetate C-7, is a colorless alcohol-soluble liquid that is the ester formed by the condensation of 1-heptanol and acetic acid.
Heptyl acetate is used as a fruit essence flavoring in foods and as a scent in perfumes. It has a woody, fruity, rumlike odor and a spicy, floral taste with a soapy, fatty texture.
References
Flavors
Perfume ingredients
Food additives
Acetate esters
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https://en.wikipedia.org/wiki/Advanced%20Mezzanine%20Card
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Advanced Mezzanine Cards are printed circuit boards (PCBs) that follow a specification of the PCI Industrial Computers Manufacturers Group (PICMG).
Known as AdvancedMC or AMC, the official specification designation is AMC.x. Originally AMC was targeted to requirements for carrier grade communications equipment, but later used in other markets.
AMC modules are designed to work standalone, hot pluggable on any carrier card (base boards and system carrier boards in AdvancedTCA Systems) or as a hot pluggable board into a backplane directly as defined by MicroTCA specifications.
The AMC standard differs from other mezzanine card standards such as PCI Mezzanine Card (PMC), PCIexpress Mezzanine Card XMC and FMC – FPGA Mezzanine Card by the 0 degree instead of 90 degree orientation of its connector enabling hot plug of the AMC.
Specifications
AMC.0 is the "base" or "core" specification. The AdvancedMC definition alone defines a protocol agnostic connector to connect to a carrier card or a backplane. Intermediate revisions are known as engineering change notices, or ECNs.
R1.0 adopted January 3, 2005
ECN-001 adopted June 2006
R2.0 adopted November 15, 2006
An AMC card can use proprietary LVDS-based signaling, or one of the following AMC specifications:
AMC.1 PCI Express (and PCI Express Advanced Switching) (ratified)
AMC.2 Gigabit Ethernet and XAUI (ratified)
AMC.3 Storage (ratified)
AMC.4 Serial RapidIO (ratified)
Sizes
There are six types of AMC cards ("Module") available. A Full-size Module is the most common, allowing up to 23.25 mm high components (from centerline of PCB). A Mid-size Module allows component heights maxed at 11.65 to 14.01 mm (depending on board location). A Compact Module allows only 8.18 mm.
AMCs used in AdvancedTCA systems
To use AMCs in ATCA-systems a special carrier card known as hybrid or cutaway carrier is required to hold one Full-size Module or two Compact-size (see connectors below). Each height is paired with a width, single or doubl
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https://en.wikipedia.org/wiki/Biocontainment
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One use of the concept of biocontainment is related to laboratory biosafety and pertains to microbiology laboratories in which the physical containment of pathogenic organisms or agents (bacteria, viruses, and toxins) is required, usually by isolation in environmentally and biologically secure cabinets or rooms, to prevent accidental infection of workers or release into the surrounding community during scientific research.
Another use of the term relates to facilities for the study of agricultural pathogens, where it is used similarly to the term "biosafety", relating to safety practices and procedures used to prevent unintended infection of plants or animals or the release of high-consequence pathogenic agents into the environment (air, soil, or water).
Terminology
The World Health Organization's 2006 publication, Biorisk management: Laboratory biosecurity guidance, defines laboratory biosafety as "the containment principles, technologies and practices that are implemented to prevent the unintentional exposure to pathogens and toxins, or their accidental release". It defines biorisk management as "the analysis of ways and development of strategies to minimize the likelihood of the occurrence of biorisks".
The term "biocontainment" is related to laboratory biosafety. Merriam-Webster's online dictionary reports the first use of the term in 1966, defined as "the containment of extremely pathogenic organisms (such as viruses) usually by isolation in secure facilities to prevent their accidental release especially during research".
The term laboratory biosafety refers to the measures taken "to reduce the risk of accidental release of or exposure to infectious disease agents", whereas laboratory biosecurity is usually taken to mean "a set of systems and practices employed in legitimate bioscience facilities to reduce the risk that dangerous biological agents will be stolen and used maliciously".
Containment types
Laboratory context
Primary containment is the first
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https://en.wikipedia.org/wiki/Kojic%20acid
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Kojic acid is an organic compound with the formula . It is a derivative of 4-pyrone that functions in nature as a chelation agent produced by several species of fungi, especially Aspergillus oryzae, which has the Japanese common name koji. Kojic acid is a by-product in the fermentation process of malting rice, for use in the manufacturing of sake, the Japanese rice wine. It is a mild inhibitor of the formation of pigment in plant and animal tissues, and is used in food and cosmetics to preserve or change colors of substances. It forms a bright red complex with ferric ions.
Biosynthesis
13C-Labeling studies have revealed at least two pathways to kojic acid. In the usual route, dehydratase enzymes convert glucose to kojic acid. Pentoses are also viable precursors in which case dihydroxyacetone is invoked as an intermediate.
Applications
Kojic acid may be used on cut fruits to prevent oxidative browning, in seafood to preserve pink and red colors, and in cosmetics to lighten skin. As an example of the latter, it is used to treat skin diseases like melasma. Kojic acid also has antibacterial and antifungal properties.
The cocrystals of kojic acid with quercetin were found to have two times better cytotoxic activity to human cervical cancer cells (HeLa) and human colon cancer cells (Caco-2) in comparison with quercetin itself.
Other effects
Kojic acid has been shown to protect Chinese hamster ovary cells against ionizing radiation-induced damage. When exposed to a lethal dose of 3 Gy gamma radiation, dogs pretreated with kojic acid had a 51-day survival rate of 66.7% while the control group died within 16 days.
Chemical reactions
Deprotonation of the ring-OH group converts kojic acid to kojate. Kojate chelates to iron(III), forming a red complex . This kind of reaction may be the basis of the biological function of kojic aicd, that is, to solubilize ferric iron.
Being a multifunctional molecule, kojic acid has diverse organic chemistry. The hydroxymethyl group
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https://en.wikipedia.org/wiki/Airline%20codes
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This is a list of airline codes. The table lists IATA's two-character airline designators, ICAO's three-character airline designators and the airline call signs (telephony designator). Historical assignments are also included.
IATA airline designator
IATA airline designators, sometimes called IATA reservation codes, are two-character codes assigned by the International Air Transport Association (IATA) to the world's airlines. The standard is described in IATA's Standard Schedules Information Manual and the codes themselves are described in IATA's Airline Coding Directory. (Both are published semiannually.)
The IATA codes were originally based on the ICAO designators which were issued in 1947 as two-letter airline identification codes (see the section below). IATA expanded the two-character-system with codes consisting of a letter and a digit (or vice versa) e.g. EasyJet's U2 after ICAO had introduced its current three-letter-system in 1982. Until then only combinations of letters were used.
Airline designator codes follow the format xx(a), i.e., two alphanumeric characters (letters or digits) followed by an optional letter. Although the IATA standard provides for three-character airline designators, IATA has not used the optional third character in any assigned code. This is because some legacy computer systems, especially the "central reservations systems", have failed to comply with the standard, notwithstanding the fact that it has been in place for twenty years. The codes issued to date comply with IATA Resolution 762, which provides for only two characters. These codes thus comply with the current airline designator standard, but use only a limited subset of its possible range.
There are three types of designator: unique, numeric/alpha and controlled duplicate (explained below):
IATA airline designators are used to identify an airline for commercial purposes in reservations, timetables, tickets, tariffs, air waybills and in telecommunications.
A fli
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https://en.wikipedia.org/wiki/Social%20Choice%20and%20Individual%20Values
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Kenneth Arrow's monograph Social Choice and Individual Values (1951, 2nd ed., 1963, 3rd ed., 2012) and a theorem within it created modern social choice theory, a rigorous melding of social ethics and voting theory with an economic flavor. Somewhat formally, the "social choice" in the title refers to Arrow's representation of how social values from the set of individual orderings would be implemented under the constitution. Less formally, each social choice corresponds to the feasible set of laws passed by a "vote" (the set of orderings) under the constitution even if not every individual voted in favor of all the laws.
The work culminated in what Arrow called the "General Possibility Theorem," better known thereafter as Arrow's (impossibility) theorem. The theorem states that, absent restrictions on either individual preferences or neutrality of the constitution to feasible alternatives, there exists no social choice rule that satisfies a set of plausible requirements. The result generalizes the voting paradox, which shows that majority voting may fail to yield a stable outcome.
Introduction
The Introduction contrasts voting and markets with dictatorship and social convention (such as those in a religious code). Both exemplify social decisions. Voting and markets facilitate social choice in a sense, whereas dictatorship and convention limit it. The former amalgamate possibly differing tastes to make a social choice. The concern is with formal aspects of generalizing such choices. In this respect it is comparable to analysis of the voting paradox from use of majority rule as a value.
Arrow asks whether other methods of taste aggregation (whether by voting or markets), using other values, remedy the problem or are satisfactory in other ways. Here logical consistency is one check on acceptability of all the values. To answer the questions, Arrow proposes removing the distinction between voting and markets in favor of a more general category of collectiv
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https://en.wikipedia.org/wiki/Recombineering
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Recombineering (recombination-mediated genetic engineering) is a genetic and molecular biology technique based on homologous recombination systems, as opposed to the older/more common method of using restriction enzymes and ligases to combine DNA sequences in a specified order. Recombineering is widely used for bacterial genetics, in the generation of target vectors for making a conditional mouse knockout, and for modifying DNA of any source often contained on a bacterial artificial chromosome (BAC), among other applications.
Development
Although developed in bacteria, much of the inspiration for recombineering techniques came from methods first developed in Saccharomyces cerevisiae where a linear plasmid was used to target genes or clone genes off the chromosome. In addition, recombination with single-strand oligonucleotides (oligos) was first shown in Saccharomyces cerevisiae. Recombination was observed to take place with oligonucleotides as short as 20 bases.
Recombineering is based on homologous recombination in Escherichia coli mediated by bacteriophage proteins, either RecE/RecT from Rac prophage or Redαβδ from bacteriophage lambda. The lambda Red recombination system is now most commonly used and the first demonstrations of Red in vivo genetic engineering were independently made by Kenan Murphy and Francis Stewart. However, Murphy's experiments required expression of RecA and also employed long homology arms. Consequently, the implications for a new DNA engineering technology were not obvious. The Stewart lab showed that these homologous recombination systems mediate efficient recombination of linear DNA molecules flanked by homology sequences as short as 30 base pairs (40-50 base pairs are more efficient) into target DNA sequences in the absence of RecA. Now the homology could be provided by oligonucleotides made to order, and standard recA cloning hosts could be used, greatly expanding the utility of recombineering.
Recombineering with dsDNA
Recomb
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https://en.wikipedia.org/wiki/Parallax%20Propeller
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The Parallax P8X32A Propeller is a multi-core processor parallel computer architecture microcontroller chip with eight 32-bit reduced instruction set computer (RISC) central processing unit (CPU) cores. Introduced in 2006, it is designed and sold by Parallax, Inc.
The Propeller microcontroller, Propeller assembly language, and Spin interpreter were designed by Parallax's cofounder and president, Chip Gracey. The Spin programming language and Propeller Tool integrated development environment (IDE) were designed by Chip Gracey and Parallax's software engineer Jeff Martin.
On August 6, 2014, Parallax Inc. released all of the Propeller 1 P8X32A hardware and tools as open-source hardware and software under the GNU General Public License (GPL) 3.0. This included the Verilog code, top-level hardware description language (HDL) files, Spin interpreter, PropellerIDE and SimpleIDE programming tools and compilers.
Multi-core architecture
Each of the eight 32-bit cores (termed a cog) has a central processing unit (CPU) which has access to 512 32-bit long words (2 KB) of instructions and data. Self-modifying code is possible and is used internally, for example, as the boot loader overwrites itself with the Spin Interpreter. Subroutines in Spin (object-based high-level code) use a call-return mechanism requiring use of a call stack. Assembly (PASM, low-level) code needs no call stack. Access to shared memory (32 KB random-access memory (RAM); 32 KB read-only memory (ROM)) is controlled via round-robin scheduling by an internal computer bus controller termed the hub. Each cog also has access to two dedicated hardware counters and a special video generator for use in generating timing signals for PAL, NTSC, VGA, servomechanism-control, and others.
Speed and power management
The Propeller can be clocked using either an internal, on-chip oscillator (providing a lower total part count, but sacrificing some accuracy and thermal stability) or an external crystal oscillator or cera
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https://en.wikipedia.org/wiki/Potted%20shrimps
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Potted shrimps is a traditional British dish made with brown shrimp flavored with nutmeg and baked in butter. The butter acts as a preservative, and cayenne pepper may also be used. Regarded as a delicacy, it is traditionally eaten with bread.
Potted shrimps was a favourite dish of Ian Fleming, who passed on his predilection to his fictional creation James Bond. Fleming reputedly used to eat the dish at Scott's Restaurant on Mount Street in London.
See also
Food preservation
Hatchet Job of the Year
Potted meat
References
Lancashire cuisine
Shrimp dishes
Foods featuring butter
Food preservation
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https://en.wikipedia.org/wiki/Marconi%20Research%20Centre
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Marconi Research Centre is the former name of the current BAE Systems Applied Intelligence Laboratories facility at Great Baddow in Essex, United Kingdom. Under its earlier name, research at this site spanned military and civilian technology covering the full range of products offered by GEC-Marconi, including radio, radar, telecommunications, mechatronics and microelectronics.
Origins
Marconi Company chose to establish itself in Chelmsford shortly after the company was founded in 1897. It first acquired the former silk-works on Hall Street before expanding to a new factory, the New Street Works, in 1912. At the same time a formal Research Department was founded under the auspices of Charles Samuel Franklin near the original Hall Street works.
The facilities were placed under the direction of the Admiralty at the outbreak of the First World War. When the Marconi Company resumed control in 1919, it was two years before the Research Department was reconstituted under H. J. Round, who had previously worked for Franklin, with a separate research team now formed under Franklin himself. Thomas Eckersley started working for Marconi at this time.
By 1924 the Marconi Company had developed short wave radio technology sufficiently to be awarded a contract from the Post Office to run elements of the Imperial Wireless Chain. Further research groups were developed, including one working on television. In 1936 it was decided to bring together the various radio, television and telephony research teams in a single location. A site was bought in Great Baddow because it was deemed sufficiently far from potential sources of electrical interference for all research work to be carried out without problems. Building work began in 1937 and by 1938 researchers started working at the site.
Pre-war activity
The new facilities were placed under the direction J. G. Robb. Research under his direction was varied, including a telephone laboratory focusing on audio research, propagation, low no
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https://en.wikipedia.org/wiki/Vertical%20tangent
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In mathematics, particularly calculus, a vertical tangent is a tangent line that is vertical. Because a vertical line has infinite slope, a function whose graph has a vertical tangent is not differentiable at the point of tangency.
Limit definition
A function ƒ has a vertical tangent at x = a if the difference quotient used to define the derivative has infinite limit:
The first case corresponds to an upward-sloping vertical tangent, and the second case to a downward-sloping vertical tangent. The graph of ƒ has a vertical tangent at x = a if the derivative of ƒ at a is either positive or negative infinity.
For a continuous function, it is often possible to detect a vertical tangent by taking the limit of the derivative. If
then ƒ must have an upward-sloping vertical tangent at x = a. Similarly, if
then ƒ must have a downward-sloping vertical tangent at x = a. In these situations, the vertical tangent to ƒ appears as a vertical asymptote on the graph of the derivative.
Vertical cusps
Closely related to vertical tangents are vertical cusps. This occurs when the one-sided derivatives are both infinite, but one is positive and the other is negative. For example, if
then the graph of ƒ will have a vertical cusp that slopes up on the left side and down on the right side.
As with vertical tangents, vertical cusps can sometimes be detected for a continuous function by examining the limit of the derivative. For example, if
then the graph of ƒ will have a vertical cusp at x = a that slopes down on the left side and up on the right side.
Example
The function
has a vertical tangent at x = 0, since it is continuous and
Similarly, the function
has a vertical cusp at x = 0, since it is continuous,
and
References
Vertical Tangents and Cusps. Retrieved May 12, 2006.
Mathematical analysis
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https://en.wikipedia.org/wiki/Eco-sufficiency
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Ecological sufficiency, or simply sufficiency, refers to the concept or strategy to reduce the environmental footprint of societies through moderating the need for energy, carbon and material-based services and products. The term was popularised by authors such as Thomas Princen, a professor at MIT, in his 2005 book ‘The Logic of Sufficiency’. As a goal, sufficiency is about ensuring that all humans can live a good life within planetary boundaries, meaning without overshooting the ecological limits of the Earth and thus limiting resource use and pollution. Princen argues that ‘seeking enough when more is possible is both intuitive and rational - personally, organizationally and ecologically. And under global ecological constraint, it is ethical.'
In order to operationalise sufficiency, principles and ideas of concrete actions and policies have been proposed by various authors. Sufficiency may be approached at the individual level as a personal attitude or life philosophy (such as in the ‘Sobriété heureuse’ concept of French environmentalist Pierre Rabhi, or Uwe Schneidewind‘s concept of the ‘Good Life’), as well as a core collective value that could amend the notion of liberal societies. In terms of lifestyles, it is strongly related to the concepts of voluntary simplicity and downshifting.
There are significant barriers to the widespread adoption of sufficiency, as it goes against current dominant social paradigms (economic growth focus, materialism, individualism, etc.). However, there are signs of change in some trends, be they motivated by environmental concerns or other co-benefits. Sufficiency usually triggers debates around the notions of needs, wants, and 'enoughness'. Its impact on the economy and the role of rebound effects are also challenges to be addressed.
The war in Ukraine and subsequent energy crisis in 2022 have put a significant pressure on energy supply, notably in Europe, and popularised the concept of sufficiency and sufficiency policies. F
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https://en.wikipedia.org/wiki/Flexibility%20%28engineering%29
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Flexibility is used as an attribute of various types of systems. In the field of engineering systems design, it refers to designs that can adapt when external changes occur. Flexibility has been defined differently in many fields of engineering, architecture, biology, economics, etc. In the context of engineering design one can define flexibility as the ability of a system to respond to potential internal or external changes affecting its value delivery, in a timely and cost-effective manner. Thus, flexibility for an engineering system is the ease with which the system can respond to uncertainty in a manner to sustain or increase its value delivery. Uncertainty is a key element in the definition of flexibility. Uncertainty can create both risks and opportunities in a system, and it is with the existence of uncertainty that flexibility becomes valuable.
Flexible Manufacturing System
Flexibility has been especially thoroughly studied for manufacturing systems. For manufacturing science eleven different classes of flexibility have been identified [Browne, 1984], [Sethi and Sethi, 1990]:
Machine flexibility - The different operation types that a machine can perform.
Material handling flexibility - The ability to move the products within a manufacturing facility.
Operation flexibility - The ability to produce a product in different ways.
Process flexibility - The set of products that the system can produce.
Product flexibility - The ability to add new products in the system.
Routing flexibility - The different routes (through machines and workshops) that can be used to produce a product in the system.
Volume flexibility - The ease to profitably increase or decrease the output of an existing system. At firm level, it is the ability of a firm to operate profitably at different output levels. Firms often use volume flexibility as a benchmark to assess their performance vis-à-vis their competitors.
Expansion flexibility - The ability to build out the capacity of a
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https://en.wikipedia.org/wiki/Hirschberg%20test
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In the fields of optometry and ophthalmology, the Hirschberg test, also Hirschberg corneal reflex test, is a screening test that can be used to assess whether a person has strabismus (ocular misalignment).
A photographic version of the Hirschberg is used to quantify strabismus.
Technique
It is performed by shining a light in the person's eyes and observing where the light reflects off the corneas. In a person with normal ocular alignment the light reflex lies slightly nasal from the center of the cornea (approximately 11 prism diopters—or 0.5mm from the pupillary axis), as a result of the cornea acting as a temporally-turned convex mirror to the observer. When doing the test, the light reflexes of both eyes are compared, and will be symmetrical in an individual with normal fixation. For an abnormal result, based on where the light lands on the cornea, the examiner can detect if there is an exotropia (abnormal eye is turned out), esotropia (abnormal eye is turned in), hypertropia (abnormal eye higher than the normal one) or hypotropia (abnormal eye is lower than the normal one).
Interpretation
In exotropia the light lands on the medial aspect of the cornea. In esotropia the light lands on the lateral aspect of the cornea. In hypertropia the light lands on the inferior aspect of the cornea. In hypotropia the light lands on the superior aspect of the cornea. A cover test can tell you the extent of the eso/exo-tropia.
Individuals can suffer from several tropias at once. In Graves ophthalmopathy, it is not uncommon to see an esotropia (due to pathology of the medial rectus muscle) co-morbid with a hypotropia (due to pathology of the inferior rectus muscle).
Krimsky Test
The Krimsky test is essentially the Hirschberg test, but with prisms employed to quantitate deviation of ocular misalignment by determining how much prism is required to centre the reflex The Krimsky test is advisably used for patients with tropias, but not with phorias.
History
The technique
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https://en.wikipedia.org/wiki/Parallel%20Element%20Processing%20Ensemble
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The Parallel Element Processing Ensemble (PEPE) was one of the very early parallel computing systems. Bell began researching the concept in the mid-1960s as a way to provide high-performance computing support for the needs of anti-ballistic missile (ABM) systems. The goal was to build a computer system that could simultaneously track hundreds of incoming ballistic missile warheads. A single PEPE system was built by Burroughs Corporation in the 1970s, by which time the US Army's ABM efforts were winding down. The design later evolved into the Burroughs Scientific Computer for commercial sales, but a lack of sales prospects led to it being withdrawn from the market.
PEPE came about as a result of predictions of the sorts of ICBM forces that would be expected in the event of an all-out Soviet attack during the 1970s. Missile fleets of both the US and USSR were growing through the 1960s, but a bigger issue was the number of warheads as a result of the move to multiple independently targetable reentry vehicles (MIRV). Computers designed for the Nike-X system were largely similar to systems like the IBM 7030, and would have been able to handle attacks with perhaps a dozen warheads arriving simultaneously. With MIRV, hundreds of targets, both warheads and decoys, would arrive at the same time, and the CPUs being used simply did not have the performance needed to analyze their trajectories quickly enough to leave time to attack them.
An initial testbed system, the "IC model", was built with 16 processors consisting of individual integrated circuits and connected to an IBM 360/65 host. This proved successful, and Burroughs won the contract to build a prototype of the full-sized 288-processor version in the early 1970s. The design featured an array of 288 (8 × 36) identical processing elements and associative addressing. Each processing element contained a minimum of control logic, the bulk of the control being concentrated in a common control unit. The control unit read in
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https://en.wikipedia.org/wiki/Hereditary%20ring
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In mathematics, especially in the area of abstract algebra known as module theory, a ring R is called hereditary if all submodules of projective modules over R are again projective. If this is required only for finitely generated submodules, it is called semihereditary.
For a noncommutative ring R, the terms left hereditary and left semihereditary and their right hand versions are used to distinguish the property on a single side of the ring. To be left (semi-)hereditary, all (finitely generated) submodules of projective left R-modules must be projective, and similarly to be right (semi-)hereditary all (finitely generated) submodules of projective right R-modules must be projective. It is possible for a ring to be left (semi-)hereditary but not right (semi-)hereditary and vice versa.
Equivalent definitions
The ring R is left (semi-)hereditary if and only if all (finitely generated) left ideals of R are projective modules.
The ring R is left hereditary if and only if all left modules have projective resolutions of length at most 1. This is equivalent to saying that the left global dimension is at most 1. Hence the usual derived functors such as and are trivial for .
Examples
Semisimple rings are left and right hereditary via the equivalent definitions: all left and right ideals are summands of R, and hence are projective. By a similar token, in a von Neumann regular ring every finitely generated left and right ideal is a direct summand of R, and so von Neumann regular rings are left and right semihereditary.
For any nonzero element x in a domain R, via the map . Hence in any domain, a principal right ideal is free, hence projective. This reflects the fact that domains are right Rickart rings. It follows that if R is a right Bézout domain, so that finitely generated right ideals are principal, then R has all finitely generated right ideals projective, and hence R is right semihereditary. Finally if R is assumed to be a principal right ideal domain,
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https://en.wikipedia.org/wiki/Drill%20floor
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The drill floor is the heart of any drilling rig. This is the area where the drill string begins its trip into the earth. It is traditionally where joints of pipe are assembled, as well as the BHA (bottom hole assembly), drilling bit, and various other tools. This is the primary work location for roughnecks and the driller. The drill floor is located directly under the derrick.
The floor is a relatively small work area in which the rig crew conducts operations, usually adding or removing drillpipe to, or from the drillstring. The rig floor is the most dangerous location on the rig because heavy iron is moved around there. Drill string connections are made or broken on the drill floor, and the driller's console for controlling the major components of the rig are located there. Attached to the rig floor is a small metal room, the doghouse, where the rig crew can meet, take breaks, and take refuge from the elements during idle times.
External links
Schlumberger Oilfield Glossary
The History of the Oil Industry
"Black Gold" Popular Mechanics, January 1930 - large photo article on oil drilling in the 1920s and 1930s
"World's Deepest Well" Popular Science, August 1938, article on the late 1930s technology of drilling oil wells
Oilfield terminology
Oil platforms
Mining equipment
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https://en.wikipedia.org/wiki/Crypt%20%28anatomy%29
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Crypts are anatomical structures that are narrow but deep invaginations into a larger structure.
One common type of anatomical crypt is the Crypts of Lieberkühn. However, it is not the only type: some types of tonsils also have crypts. Because these crypts allow external access to the deep portions of the tonsils, these tonsils are more vulnerable to infection.
References
External links
- "Lymphoid Tissues and Organs: tonsil"
Histology of crypt of tonsil at siumed.edu
Anatomy
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https://en.wikipedia.org/wiki/Hereditarily%20countable%20set
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In set theory, a set is called hereditarily countable if it is a countable set of hereditarily countable sets.
Results
The inductive definition above is well-founded and can be expressed in the language of first-order set theory.
Equivalent properties
A set is hereditarily countable if and only if it is countable, and every element of its transitive closure is countable. If the axiom of countable choice holds, then a set is hereditarily countable if and only if its transitive closure is countable.
The collection of all h. c. sets
The class of all hereditarily countable sets can be proven to be a set from the axioms of Zermelo–Fraenkel set theory (ZF) and is set is designated . In particular, the existence does not require any form of the axiom of choice. Constructive Zermelo-Freankel (CZF) does not prove the class to be a set.
Model theory
This class is a model of Kripke–Platek set theory with the axiom of infinity (KPI), if the axiom of countable choice is assumed in the metatheory.
If , then .
Generalizations
More generally, a set is hereditarily of cardinality less than κ if it is of cardinality less than κ, and all its elements are hereditarily of cardinality less than κ; the class of all such sets can also be proven to be a set from the axioms of ZF, and is designated . If the axiom of choice holds and the cardinal κ is regular, then a set is hereditarily of cardinality less than κ if and only if its transitive closure is of cardinality less than κ.
See also
Hereditarily finite set
Constructible universe
External links
"On Hereditarily Countable Sets" by Thomas Jech
Set theory
Large cardinals
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https://en.wikipedia.org/wiki/Nerve%20%28category%20theory%29
|
In category theory, a discipline within mathematics, the nerve N(C) of a small category C is a simplicial set constructed from the objects and morphisms of C. The geometric realization of this simplicial set is a topological space, called the classifying space of the category C. These closely related objects can provide information about some familiar and useful categories using algebraic topology, most often homotopy theory.
Motivation
The nerve of a category is often used to construct topological versions of moduli spaces. If X is an object of C, its moduli space should somehow encode all objects isomorphic to X and keep track of the various isomorphisms between all of these objects in that category. This can become rather complicated, especially if the objects have many non-identity automorphisms. The nerve provides a combinatorial way of organizing this data. Since simplicial sets have a good homotopy theory, one can ask questions about the meaning of the various homotopy groups πn(N(C)). One hopes that the answers to such questions provide interesting information about the original category C, or about related categories.
The notion of nerve is a direct generalization of the classical notion of classifying space of a discrete group; see below for details.
Construction
Let C be a small category. There is a 0-simplex of N(C) for each object of C. There is a 1-simplex for each morphism f : x → y in C. Now suppose that f: x → y and g : y → z are morphisms in C. Then we also have their composition gf : x → z. The diagram suggests our course of action: add a 2-simplex for this commutative triangle. Every 2-simplex of N(C) comes from a pair of composable morphisms in this way. The addition of these 2-simplices does not erase or otherwise disregard morphisms obtained by composition, it merely remembers that this is how they arise.
In general, N(C)k consists of the k-tuples of composable morphisms
of C. To complete the definition of N(C) as a simplicial set, w
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https://en.wikipedia.org/wiki/Karatmeter
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The Karatmeter is a scientific instrument which uses X-rays to give an exact reading of the purity of gold. The Karatmeter is also referred to as a X-Ray fluorescence (XRF) spectrometer. Due to its very high precision and fast result, X-ray analysis has been adopted by international agencies in India as part of the certification process used to hallmark gold. It is an accurate, non-destructive means of testing the purity of gold and other related elements. Analyzing gold using XRF spectrometers gives the purity of gold, up to 10-12 microns and hence it gives the analysis of coating only.
Using this technique, the precise percentage or karat (of karat) in a solid piece of jewelry can be determined in 30 seconds. It also accurately (up to 10-12 microns) determines the element composition of all types of gold, white gold, platinum, silver, palladium, rhodium and related alloys.
Energy dispersive X-Ray fluorescence (ED-XRF) is a simple, accurate and economic analytical methods for the determination of the chemical composition of many types of materials. It is non-destructive and reliable, requires very little sample preparation and is suitable for solid, liquid and powdered samples. It can be used for a wide range of elements, from Chlorine (17) to Uranium (92), and provides detection limits at the sub-ppm level.
There are many models of Gold Purity Testing machines available - from portable (light weight) to industrial grade machines.
Apart from X-ray spectrometer technique, other older traditional methods are using the TouchStone and Acid to test the gold purity. But TouchStone and Acid are destructive testing - a tiny sample of gold is cut and then tested. The sample is rubbed on TouchStone and a drop of acid is put on it and the goldsmith observes the residue using a magnifying lens. Based on experience, gold smith can determine purity of sample.
References
Gold
Measuring instruments
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https://en.wikipedia.org/wiki/Network%20Security%20Services
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Network Security Services (NSS) is a collection of cryptographic computer libraries designed to support cross-platform development of security-enabled client and server applications with optional support for hardware TLS/SSL acceleration on the server side and hardware smart cards on the client side. NSS provides a complete open-source implementation of cryptographic libraries supporting Transport Layer Security (TLS) / Secure Sockets Layer (SSL) and S/MIME. NSS releases prior to version 3.14 are tri-licensed under the Mozilla Public License 1.1, the GNU General Public License, and the GNU Lesser General Public License. Since release 3.14, NSS releases are licensed under GPL-compatible Mozilla Public License 2.0.
History
NSS originated from the libraries developed when Netscape invented the SSL security protocol.
FIPS 140 validation and NISCC testing
The NSS software crypto module has been validated five times (in 1997, 1999, 2002, 2007, and 2010) for conformance to FIPS 140 at Security Levels 1 and 2. NSS was the first open source cryptographic library to receive FIPS 140 validation. The NSS libraries passed the NISCC TLS/SSL and S/MIME test suites (1.6 million test cases of invalid input data).
Applications that use NSS
AOL, Red Hat, Sun Microsystems/Oracle Corporation, Google and other companies and individual contributors have co-developed NSS. Mozilla provides the source code repository, bug tracking system, and infrastructure for mailing lists and discussion groups. They and others named below use NSS in a variety of products, including the following:
Mozilla client products, including Firefox, Thunderbird, SeaMonkey, and Firefox for mobile.
AOL Communicator and AOL Instant Messenger (AIM)
Open source client applications such as Evolution, Pidgin, and OpenOffice.org 2.0 onward (and its descendants).
Server products from Red Hat: Red Hat Directory Server, Red Hat Certificate System, and the mod nss SSL module for the Apache web server.
Sun server produ
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https://en.wikipedia.org/wiki/Discrete%20Poisson%20equation
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In mathematics, the discrete Poisson equation is the finite difference analog of the Poisson equation. In it, the discrete Laplace operator takes the place of the Laplace operator. The discrete Poisson equation is frequently used in numerical analysis as a stand-in for the continuous Poisson equation, although it is also studied in its own right as a topic in discrete mathematics.
On a two-dimensional rectangular grid
Using the finite difference numerical method to discretize
the 2-dimensional Poisson equation (assuming a uniform spatial discretization, ) on an grid gives the following formula:
where and . The preferred arrangement of the solution vector is to use natural ordering which, prior to removing boundary elements, would look like:
This will result in an linear system:
where
is the identity matrix, and , also , is given by:
and is defined by
For each equation, the columns of correspond to a block of components in :
while the columns of to the left and right of each correspond to other blocks of components within :
and
respectively.
From the above, it can be inferred that there are block columns of in . It is important to note that prescribed values of (usually lying on the boundary) would have their corresponding elements removed from and . For the common case that all the nodes on the boundary are set, we have and , and the system would have the dimensions , where and would have dimensions .
Example
For a 3×3 ( and ) grid with all the boundary nodes prescribed, the system would look like:
with
and
As can be seen, the boundary 's are brought to the right-hand-side of the equation. The entire system is while and are and given by:
and
Methods of solution
Because is block tridiagonal and sparse, many methods of solution
have been developed to optimally solve this linear system for .
Among the methods are a generalized Thomas algorithm with a resulting computational complexity of , cyclic reduction, successive o
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https://en.wikipedia.org/wiki/Satisfiability%20modulo%20theories
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In computer science and mathematical logic, satisfiability modulo theories (SMT) is the problem of determining whether a mathematical formula is satisfiable. It generalizes the Boolean satisfiability problem (SAT) to more complex formulas involving real numbers, integers, and/or various data structures such as lists, arrays, bit vectors, and strings. The name is derived from the fact that these expressions are interpreted within ("modulo") a certain formal theory in first-order logic with equality (often disallowing quantifiers). SMT solvers are tools that aim to solve the SMT problem for a practical subset of inputs. SMT solvers such as Z3 and cvc5 have been used as a building block for a wide range of applications across computer science, including in automated theorem proving, program analysis, program verification, and software testing.
Since Boolean satisfiability is already NP-complete, the SMT problem is typically NP-hard, and for many theories it is undecidable. Researchers study which theories or subsets of theories lead to a decidable SMT problem and the computational complexity of decidable cases. The resulting decision procedures are often implemented directly in SMT solvers; see, for instance, the decidability of Presburger arithmetic. SMT can be thought of as a constraint satisfaction problem and thus a certain formalized approach to constraint programming.
Basic terminology
Formally speaking, an SMT instance is a formula in first-order logic, where some function and predicate symbols have additional interpretations, and SMT is the problem of determining whether such a formula is satisfiable. In other words, imagine an instance of the Boolean satisfiability problem (SAT) in which some of the binary variables are replaced by predicates over a suitable set of non-binary variables. A predicate is a binary-valued function of non-binary variables. Example predicates include linear inequalities (e.g., ) or equalities involving uninterpreted terms and funct
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https://en.wikipedia.org/wiki/Timeline%20of%20immunology
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The following are notable events in the Timeline of immunology:
1550 BCE – The Ebers papyrus recommends placing a poultice on a tumor and then making an incision, which would induce infection and cause regression of the tumor.
1549 – The earliest account of inoculation of smallpox (variolation) occurs in Wan Quan's (1499–1582) Douzhen Xinfa (痘疹心法).
1718 – Smallpox inoculation in Ottoman Empire realized by West, and Henry Kipkosgei , recorded the positive effects of variolation.
1761 – A case of breast cancer cured after ulcerating and getting infected is reported by Lambergen
1796 – First demonstration of smallpox vaccination (Edward Jenner)
1808 – 1813 - First experimental demonstration of the germ theory of disease by Agostino Bassi though he does not formally propose the theory until 1844
1813 – Vautier reports spontaneous remission of cancer after gangrene infection (later to be known as Clostridium perfringens)
1829 – Another case of spontaneous remission of breast cancer after a patient refused surgery and the tumor ruptured, became infected and during a febrile illness with purulent discharge, it shrunk and disappeared after a few weeks. (Guillaume Dupuytren)
1837 – Description of the role of microbes in putrefaction and fermentation (Theodore Schwann)
1838 – Confirmation of the role of yeast in fermentation of sugar to alcohol (Charles Cagniard-Latour)
1850 – Demonstration of the contagious nature of puerperal fever (childbed fever) (Ignaz Semmelweis)
1857–1870 – Confirmation of the role of microbes in fermentation (Louis Pasteur)
1862 – Phagocytosis (Ernst Haeckel)
1867 – Aseptic practice in surgery using carbolic acid (Joseph Lister)
1868 – Busch discovered that a sarcoma patient being surgically intervened to remove the tumor, after being exposed to a patient suffering from erysipelas, got a skin infection and her tumor disappeared. He inoculated some other cancer patients with many successes.
1876 – Demonstration that microbes can cause
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https://en.wikipedia.org/wiki/Admissible%20set
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In set theory, a discipline within mathematics, an admissible set is a transitive set such that is a model of Kripke–Platek set theory (Barwise 1975).
The smallest example of an admissible set is the set of hereditarily finite sets. Another example is the set of hereditarily countable sets.
See also
Admissible ordinal
References
Barwise, Jon (1975). Admissible Sets and Structures: An Approach to Definability Theory, Perspectives in Mathematical Logic, Volume 7, Springer-Verlag. Electronic version on Project Euclid.
Set theory
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https://en.wikipedia.org/wiki/Code%20%28set%20theory%29
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In set theory, a code for a hereditarily countable set
is a set
such that there is an isomorphism between (ω,E) and (X,) where X is the transitive closure of {x}. If X is finite (with cardinality n), then use n×n instead of ω×ω and (n,E) instead of (ω,E).
According to the axiom of extensionality, the identity of a set is determined by its elements. And since those elements are also sets, their identities are determined by their elements, etc.. So if one knows the element relation restricted to X, then one knows what x is. (We use the transitive closure of {x} rather than of x itself to avoid confusing the elements of x with elements of its elements or whatever.) A code includes that information identifying x and also information about the particular injection from X into ω which was used to create E. The extra information about the injection is non-essential, so there are many codes for the same set which are equally useful.
So codes are a way of mapping into the powerset of ω×ω. Using a pairing function on ω (such as (n,k) goes to (n2+2·n·k+k2+n+3·k)/2), we can map the powerset of ω×ω into the powerset of ω. And we can map the powerset of ω into the Cantor set, a subset of the real numbers. So statements about can be converted into statements about the reals. Therefore,
Codes are useful in constructing mice.
See also
L(R)
References
William J. Mitchell,"The Complexity of the Core Model","Journal of Symbolic Logic",Vol.63,No.4,December 1998,page 1393.
Set theory
Inner model theory
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https://en.wikipedia.org/wiki/Ducking
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In audio engineering, ducking is an audio effect commonly used in radio and pop music, especially dance music. In ducking, the level of one audio signal is reduced by the presence of another signal. In radio this can typically be achieved by lowering (ducking) the volume of a secondary audio track when the primary track starts, and lifting the volume again when the primary track is finished. A typical use of this effect in a daily radio production routine is for creating a voice-over: a foreign language original sound is dubbed (and ducked) by a professional speaker reading the translation. Ducking becomes active as soon as the translation starts.
In music, the ducking effect is applied in more sophisticated ways where a signal's volume is delicately lowered by another signal's presence. Ducking here works through the use of a "side chain" gate. In other words, one track is made quieter (the ducked track) whenever another (the ducking track) gets louder. This may be done with a gate with its ducking function engaged or by a dedicated ducker.
A typical application is to achieve an impression similar to the "pumping" effect. The difference between ducking and side-chain pumping is that in ducking the attenuation is by a specific range while side-chain compression creates variable attenuation. Ducking may be used in place of mirrored equalization to combat masking, for example with the bass guitar ducked under the kick drum, resembling subtle side-chain pumping. A ducking system may be created where one track ducks another, which ducks another, and so on. Examples include Portishead's "Biscuit".
Used most often to turn down the music when the DJ speaks, ducking may be used to combat the muffling and distancing effect of reverb and delay. The ducker is inserted into the reverb and delay line and keyed to a dry track to duck its own reverb and delay so that when the dry track exceeds the ducker's threshold by reaching a certain amplitude the reverb and delay are atten
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https://en.wikipedia.org/wiki/D-Link%20G604T%20network%20adaptor
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The DSL-G604T is a first D-Link Wireless/ADSL router which firmware is based on open source the MontaVista Linux. The DSL-G604T was introduced in November 2004. This model has been discontinued.
Specifications
Hardware
CPU: Texas Instrument AR7W MIPS 4KEc based SoC with built-in ADSL and Ethernet interfaces
DRAM Memory: 16Mb
Flash Memory: 2Mb SquashFS file system
Wi-Fi: TI MiniPCI card
Ethernet: 5-port Ethernet hub (1 internal, 4 external)
Firmware
The G604T runs MontaVista and busybox Linux which allows a degrejje of customisation with customised firmware. These and similar units from D-Link appear to have an issue that causes certain services to fail when using the factory provided firmware, namely the Debian package update service being interrupted due to a faulty DNS through DHCP issue at the kernel level. A v2.00B06.AU_20060728 patch was made available through their downloads section that provided some level of correction, but it was not a complete fix and the issue would resurface intermittently. When the issue was originally reported, D-Link seemed to have misunderstood that the same issue has been discovered by the Linux community at large to be common across a number of their router models and they failed to provide a complete fix across the board for all adsl router models.
Russian version of the firmware (prefix .RU, e.g. V1.00B02T02.RU.20041014) has restrictions on configuring firewall rules – user can only change sender's address (computer address in the LAN segment) and the recipient's port. The web interface with Russian firmware also differs from the English interface.
Default settings
When running the D-link DSL-G604T router for the first time (or resetting), the device is configured with a default IP address (192.168.1.1), username (admin) and password (admin). Default username and password can also be printed on the router itself, in the manual, or on the box.
Problems
Security
D-Link DSL-G604T has Cross-site scripting (XSS) vulne
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https://en.wikipedia.org/wiki/DLL%20injection
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In computer programming, DLL injection is a technique used for running code within the address space of another process by forcing it to load a dynamic-link library. DLL injection is often used by external programs to influence the behavior of another program in a way its authors did not anticipate or intend. For example, the injected code could hook system function calls, or read the contents of password textboxes, which cannot be done the usual way. A program used to inject arbitrary code into arbitrary processes is called a DLL injector.
Approaches on Microsoft Windows
There are multiple ways on Microsoft Windows to force a process to load and execute code in a DLL that the authors did not intend:
DLLs listed in the registry entry HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Windows\AppInit_DLLs are loaded into every process that loads User32.dll during the initial call of that DLL. Beginning with Windows Vista, AppInit_DLLs are disabled by default. Beginning with Windows 7, the AppInit_DLL infrastructure supports code signing. Starting with Windows 8, the entire AppInit_DLL functionality is disabled when Secure Boot is enabled, regardless of code signing or registry settings.
DLLs listed under the registry key HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\AppCertDLLs are loaded into every process that calls the Win32 API functions CreateProcess, CreateProcessAsUser, CreateProcessWithLogonW, CreateProcessWithTokenW and WinExec. That is the right way to use legal DLL injection on current version of Windows - Windows 10. DLL must be signed by a valid certificate.
Process manipulation functions such as CreateRemoteThread or code injection techniques such as AtomBombing, can be used to inject a DLL into a program after it has started.
Open a handle to the target process. This can be done by spawning the process or by keying off something created by that process that is known to exist – for instance, a window with a predic
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https://en.wikipedia.org/wiki/S3%20Trio
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The S3 Trio range were popular video cards for personal computers and were S3's first fully integrated graphics accelerators. As the name implies, three previously separate components were now included in the same ASIC: the graphics core, RAMDAC and clock generator. The increased integration allowed a graphics card to be simpler than before and thus cheaper to produce.
Variants
The Trio64 and 64V+, first appeared in 1995, are essentially fully integrated solutions based upon the earlier Vision 864 and 868 accelerator chipsets. Like the 868, the 64V+ has a video acceleration engine that can perform YUV to RGB color space conversion and horizontal linear filtered scaling. Unlike the Vision964/968, the Trio chips do not support VRAM, and are limited to FPM DRAM and EDO DRAM only. The 2D graphics hardware was later used in the ViRGE.
The Trio32 is a low-cost version of the Trio64 with a narrower 32-bit DRAM interface (vs. 64-bit).
The Trio64V2 improved on the 64V+ by including vertical bilinear filtering. The 2D graphics core was later used in the ViRGE/DX and ViRGE/GX. Like the corresponding ViRGE chips, the 64V2 also came in /DX and /GX variants, with the latter supporting more modern SDRAM or SGRAM. The final version, called the Trio3D, was effectively the 128-bit successor to the ViRGE/GX2.
The various Trio chips were used on many motherboards. Because of the popularity of the series and the resulting compatibility advantages, they are used in various PC emulation and virtualization packages such as DOSBox, Microsoft Virtual PC, PCem and 86Box.
Specifications
Motherboard interface: ISA, VLB, PCI, AGP (Trio3D only)
Video Connector: 15-pin VGA connector
External links
Virtual PC 4.0 Test Results, S3 Trio emulated graphics chipset
S3 Graphics - Download Drivers - Legacy Software Archive
Vogons Vintage Driver Library
Graphics cards
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https://en.wikipedia.org/wiki/Neville%27s%20algorithm
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In mathematics, Neville's algorithm is an algorithm used for polynomial interpolation that was derived by the mathematician Eric Harold Neville in 1934. Given n + 1 points, there is a unique polynomial of degree ≤ n which goes through the given points. Neville's algorithm evaluates this polynomial.
Neville's algorithm is based on the Newton form of the interpolating polynomial and the recursion relation for the divided differences. It is similar to Aitken's algorithm (named after Alexander Aitken), which is nowadays not used.
The algorithm
Given a set of n+1 data points (xi, yi) where no two xi are the same, the interpolating polynomial is the polynomial p of degree at most n with the property
p(xi) = yi for all i = 0,…,n
This polynomial exists and it is unique. Neville's algorithm evaluates the polynomial at some point x.
Let pi,j denote the polynomial of degree j − i which goes through the points (xk, yk) for k = i, i + 1, …, j. The
pi,j satisfy the recurrence relation
{|
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This recurrence can calculate
p0,n(x),
which is the value being sought. This is Neville's algorithm.
For instance, for n = 4, one can use the recurrence to fill the triangular tableau below from the left to the right.
{|
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This process yields
p0,4(x),
the value of the polynomial going through the n + 1 data points (xi, yi) at the point x.
This algorithm needs O(n2) floating point operations to interpolate a single point, and O(n3) floating point operations to interpolate a polynomial of degree n.
The derivative of the polynomial can be obtained in the same manner, i.e:
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Application to numerical differentiation
Lyness and Moler showed in 1966 that using undetermined coefficients for the polynomials in Neville's algorithm, one can compute the Maclaurin expansion of the final interpolating polynomial, which y
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https://en.wikipedia.org/wiki/Muromonab-CD3
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Muromonab-CD3 (trade name Orthoclone OKT3, marketed by Janssen-Cilag) is an immunosuppressant drug given to reduce acute rejection in patients with organ transplants. It is a monoclonal antibody targeted at the CD3 receptor, a membrane protein on the surface of T cells. It was the first monoclonal antibody to be approved for clinical use in humans.
History
Muromonab-CD3 was approved by the U.S. Food and Drug Administration (FDA) in 1986, making it the first monoclonal antibody to be approved anywhere as a drug for humans. In the European Communities, it was the first drug to be approved under the directive 87/22/EWG, a precursor of the European Medicines Agency (EMEA) centralised approval system in the European Union. This process included an assessment by the Committee for Proprietary Medicinal Products (CPMP, now CHMP), and a subsequent approval by the national health agencies; in Germany, for example, in 1988 by the Paul Ehrlich Institute in Frankfurt. However, the manufacturer of muromonab-CD3 has voluntarily withdrawn it from the United States market in 2010 due to numerous side-effects, better-tolerated alternatives and declining usage.
Indications
Muromonab-CD3 is approved for the therapy of acute, glucocorticoid-resistant rejection of allogeneic renal, heart and liver transplants. Unlike the monoclonal antibodies basiliximab and daclizumab, it is not approved for prophylaxis of transplant rejection, although a 1996 review has found it to be safe for that purpose.
It has also been investigated for use in treating T-cell acute lymphoblastic leukemia.
Pharmacodynamics and chemistry
T cells recognise antigens primarily via the T cell receptor (TCR). CD3 is one of the proteins that make up the TCR complex. The TCR transduces the signal for the T cell to proliferate and attack the antigen.
Muromonab-CD3 is a murine (mouse) monoclonal IgG2a antibody which was created using hybridoma technology. It binds to the T cell receptor-CD3-complex (specifically the CD3
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https://en.wikipedia.org/wiki/List%20of%20microprocessors
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This is a list of microprocessors.
Altera
Nios 16-bit (soft processor)
Nios II 32-bit (soft processor)
AMD
List of AMD K5 processors
List of AMD Athlon processors
List of AMD Athlon 64 processors
List of AMD Athlon XP processors
List of AMD Duron processors
List of AMD Opteron processors
List of AMD Sempron processors
List of AMD Turion processors
List of AMD Athlon X2 processors
List of AMD Phenom processors
List of AMD FX processors
List of AMD Ryzen processors
Apollo
PRISM
ARM
ARM
Atmel
AVR32
AVR
AT&T
Hobbit
Bell Labs
Bellmac 32
BLX IC Design Corporation
Godson/Loongson
Broadcom
XLS 200 series multicore processor
Centaur Technology/IDT
WinChip
Computer Cowboys
Sh-Boom
Cyrix
486, 5x86, 6x86
Data General
microNOVA mN601 and mN602
microECLIPSE
Centre for Development of Advanced Computing
VEGA Microprocessors
Digital Equipment Corporation
DEC T-11
DEC J-11
DEC V-11
MicroVAX 78032
CVAX
Rigel
Mariah
NVAX
Alpha 21064
Alpha 21164
Alpha 21264
Alpha 21364
StrongARM
DM&P Electronics
Vortex86
Emotion Engine by Sony & Toshiba
Emotion Engine
Elbrus
Elbrus 2K (VLIW design)
Electronic Arrays
Electronic Arrays 9002
EnSilica
eSI-RISC
Fairchild Semiconductor
9440
F8
Clipper
Freescale Semiconductor (formerly Motorola)
List of Freescale products
Fujitsu
FR
FR-V
SPARC64 V
Garrett AiResearch/American Microsystems
MP944
Google
Tensor processing unit
Harris Semiconductor
Harris RTX2000
Hewlett-Packard
Capricorn (microprocessor)
FOCUS 32-bit stack architecture
PA-7000 PA-RISC Version 1.0 (32-bit)
PA-7100 PA-RISC Version 1.1
PA-7100LC
PA-7150
PA-7200
PA-7300LC
PA-8000 PA-RISC Version 2.0 (64-bit)
PA-8200
PA-8500
PA-8600
PA-8700
PA-8800
PA-8900
Saturn Nibble CPU (4-bit)
Hitachi
SuperH SH-1/SH-2 etc.
Inmos
Transputer T2/T4/T8
IBM
1977 – OPD Mini Processor
1986 – IBM ROMP
2000 – Gekko processor
2005 – Xenon processor
2006 – Cell processor
2006 – Broadway processor
2012 – Espresso
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https://en.wikipedia.org/wiki/Zero-lift%20axis
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A cambered aerofoil generates no lift when it is moving parallel to an axis called the zero-lift axis (or the zero-lift line.) When the angle of attack on an aerofoil is measured relative to the zero-lift axis it is true to say the lift coefficient is zero when the angle of attack is zero. For this reason, on a cambered aerofoil the zero-lift line is better than the chord line when describing the angle of attack.
When symmetric aerofoils are moving parallel to the chord line of the aerofoil, zero lift is generated. However, when cambered aerofoils are moving parallel to the chord line, lift is generated. (See diagram at right.) For symmetric aerofoils, the chord line and the zero lift line are the same.
See also
Angle of attack
Aerobatics
Aerobatic maneuver
References
Anderson, John D. Jr (2005), Introduction to Flight, Section 7.4 (fifth edition), McGraw-Hill
L. J. Clancy (1975), Aerodynamics, Sections 5.6 and 5.7, Pitman Publishing, London.
Kermode, A.C. (1972), Mechanics of Flight, Chapter 3, (p. 76, eighth edition), Pitman Publishing
Notes
Aerodynamics
Aerospace engineering
Aircraft manufacturing
Aircraft wing design
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https://en.wikipedia.org/wiki/Clobber
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Clobber is an abstract strategy game invented in 2001 by combinatorial game theorists Michael H. Albert, J.P. Grossman and Richard Nowakowski. It has subsequently been studied by Elwyn Berlekamp and Erik Demaine among others. Since 2005, it has been one of the events in the Computer Olympiad.
Details
Clobber is best played with two players and takes an average of 15 minutes to play. It is suggested for ages 8 and up. It is typically played on a rectangular white and black checkerboard. Players take turns to move one of their own pieces onto an orthogonally adjacent opposing piece, removing it from the game. The winner of the game is the player who makes the last move (i.e. whose opponent cannot move).
To start the game, each of the squares on the checkerboard is occupied by a stone. White stones are placed on the white squares and black stones on the black squares. To move, the player must pick up one of his or her own stones and "clobber" an opponent's stone on an adjacent square, either horizontally or vertically. Once the opponent's stone is clobbered, it must then be removed from the board and replaced by the stone that was moved. The player who, on their turn, is unable to move, loses the game.
Variants
In computational play (e.g., Computer Olympiad), clobber is generally played on a 10x10 board. There are also variations in the initial layout of the pieces. Another variant is Cannibal Clobber, where a stone may not only capture stones of the opponent but also other stones of its owner. An advantage of Cannibal Clobber over Clobber is that a player may not only win, but win by a non-trivial margin. Cannibal Clobber was proposed in the summer of 2003 by Ingo Althoefer. Another variant, also proposed by Ingo Althoefer in 2015, is San Jego: Here the pieces are not clobbered, but stacked to towers. Each tower belongs to the player with the piece on its top. At the end the player with the highest tower is declared winner. Draws are possible.
References
External
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https://en.wikipedia.org/wiki/Joule%20effect
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Joule effect and Joule's law are any of several different physical effects discovered or characterized by English physicist James Prescott Joule. These physical effects are not the same, but all are frequently or occasionally referred to in the literature as the "Joule effect" or "Joule law" These physical effects include:
"Joule's first law" (Joule heating), a physical law expressing the relationship between the heat generated and the current flowing through a conductor.
Joule's second law states that the internal energy of an ideal gas is independent of its volume and pressure, depending only on its temperature.
Magnetostriction, a property of ferromagnetic materials that causes them to change their shape when subjected to a magnetic field.
The Joule effect (during Joule expansion), the temperature change of a gas (usually cooling) when it is allowed to expand freely.
The Joule–Thomson effect, the temperature change of a gas when it is forced through a valve or porous plug while keeping it insulated so that no heat is exchanged with the environment.
The Gough–Joule effect or the Gow–Joule effect, which is the tendency of elastomers to contract if heated while they are under tension.
Joule's first law
Between 1840 and 1843, Joule carefully studied the heat produced by an electric current. From this study, he developed Joule's laws of heating, the first of which is commonly referred to as the Joule effect. Joule's first law expresses the relationship between heat generated in a conductor and current flow, resistance, and time.
Magnetostriction
The magnetostriction effect describes a property of ferromagnetic materials which causes them to change their shape when subjected to a magnetic field. Joule first reported observing the change in the length of ferromagnetic rods in 1842.
Joule expansion
In 1845, Joule studied the free expansion of a gas into a larger volume. This became known as Joule expansion. The cooling of a gas by allowing it to expand freel
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https://en.wikipedia.org/wiki/Reproductive%20isolation
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The mechanisms of reproductive isolation are a collection of evolutionary mechanisms, behaviors and physiological processes critical for speciation. They prevent members of different species from producing offspring, or ensure that any offspring are sterile. These barriers maintain the integrity of a species by reducing gene flow between related species.
The mechanisms of reproductive isolation have been classified in a number of ways. Zoologist Ernst Mayr classified the mechanisms of reproductive isolation in two broad categories: pre-zygotic for those that act before fertilization (or before mating in the case of animals) and post-zygotic for those that act after it. The mechanisms are genetically controlled and can appear in species whose geographic distributions overlap (sympatric speciation) or are separate (allopatric speciation).
Pre-zygotic isolation
Pre-zygotic isolation mechanisms are the most economic in terms of the natural selection of a population, as resources are not wasted on the production of a descendant that is weak, non-viable or sterile. These mechanisms include physiological or systemic barriers to fertilization.
Temporal or habitat isolation
Any of the factors that prevent potentially fertile individuals from meeting will reproductively isolate the members of distinct species. The types of barriers that can cause this isolation include: different habitats, physical barriers, and a difference in the time of sexual maturity or flowering.
An example of the ecological or habitat differences that impede the meeting of potential pairs occurs in two fish species of the family Gasterosteidae (sticklebacks). One species lives all year round in fresh water, mainly in small streams. The other species lives in the sea during winter, but in spring and summer individuals migrate to river estuaries to reproduce. The members of the two populations are reproductively isolated due to their adaptations to distinct salt concentrations.
An example of rep
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https://en.wikipedia.org/wiki/Forma%20specialis
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Forma specialis (plural: formae speciales), abbreviated f. sp. (plural ff. spp.) without italics, is an informal taxonomic grouping allowed by the International Code of Nomenclature for algae, fungi, and plants, that is applied to a parasite (most frequently a fungus) which is adapted to a specific host. This classification may be applied by authors who do not feel that a subspecies or variety name is appropriate, and it is therefore not necessary to specify morphological differences that distinguish this form. The literal meaning of the term is 'special form', but this grouping does not correspond to the more formal botanical use of the taxonomic rank of forma or form.
An example is Puccinia graminis f. sp. avenae, which affects oats.
An alternative term in contexts not related to biological nomenclature is physiological race (sometimes also given as biological race, and in that context treated as synonymous with biological form), except in that the name of a race is added after the binomial scientific name (and may be arbitrary, e.g. an alphanumeric code, usually with the word "race"), e.g. "Podosphaera xanthii race S". A forma specialis is used as part of the infraspecific scientific name (and follows Latin-based scientific naming conventions), inserted after the interpolation "f. sp.", as in the "Puccinia graminis f. sp. avenae" example.
History, and use with "pathotype"
The forma specialis category was introduced and recommended in the International Code of Botanical Nomenclature of 1930, but was not widely adopted. Fungal pathogens within Alternaria alternata species have also been called pathotypes (not to be confused with pathotype as used in bacteriology) by author Syoyo Nishimura who stated:"[E]ach pathogen should be called a distinct pathotype of A. alternata"
Some authors have subsequently used forma specialis and "pathotype" together for the species A. alternata: "Currently there are seven pathotypes of A. alternata described ..., but this term is
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https://en.wikipedia.org/wiki/Dunce%20hat%20%28topology%29
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In topology, the dunce hat is a compact topological space formed by taking a solid triangle and gluing all three sides together, with the orientation of one side reversed. Simply gluing two sides oriented in the opposite direction would yield a cone much like the dunce cap, but the gluing of the third side results in identifying the base of the cap with a line joining the base to the point.
Name
The name is due to E. C. Zeeman, who observed that any contractible 2-complex (such as the dunce hat) after taking the Cartesian product with the closed unit interval seemed to be collapsible. This observation became known as the Zeeman conjecture and was shown by Zeeman to imply the Poincaré conjecture.
Properties
The dunce hat is contractible, but not collapsible. Contractibility can be easily seen by noting that the dunce hat embeds in the 3-ball and the 3-ball deformation retracts onto the dunce hat. Alternatively, note that the dunce hat is the CW-complex obtained by gluing the boundary of a 2-cell onto the circle. The gluing map is homotopic to the identity map on the circle and so the complex is homotopy equivalent to the disc. By contrast, it is not collapsible because it does not have a free face.
See also
House with two rooms
List of topologies
References
Topological spaces
Algebraic topology
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https://en.wikipedia.org/wiki/Digital%20subchannel
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In broadcasting, digital subchannels are a method of transmitting more than one independent program stream simultaneously from the same digital radio or television station on the same radio frequency channel. This is done by using data compression techniques to reduce the size of each individual program stream, and multiplexing to combine them into a single signal. The practice is sometimes called "multicasting".
ATSC television
United States
The ATSC digital television standard used in the United States supports multiple program streams over-the-air, allowing television stations to transmit one or more subchannels over a single digital signal. A virtual channel numbering scheme distinguishes broadcast subchannels by appending the television channel number with a period digit (".xx"). Simultaneously, the suffix indicates that a television station offers additional programming streams. By convention, the suffix position ".1" is normally used to refer to the station's main digital channel and the ".0" position is reserved for analog channels. For example, most of the owned-and-operated stations/affiliates of Trinity Broadcasting Network transmit five streams in the following format:
The most of any large broadcaster in the United States, Ion Television stations transmit eight channels (in standard definition) and the Katz Broadcasting subchannel services Court TV, Ion Mystery, Bounce TV, Laff, Grit, Defy TV, and Scripps News. More programming streams can be fit into a single channel space at the cost of broadcast quality. Among smaller stations, KAXT-CD in San Francisco is believed to have the most feeds of any individual over-the-air broadcaster, offering twelve video and several audio feeds (all transmitted in standard definition). WANN-CD in Atlanta, Georgia, with ten video and ten audio feeds, comes at a close second. Several cable-to-air broadcasters, such as those in Willmar, Minnesota and Cortez, Colorado, have multiplexed more than five separate cable telev
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https://en.wikipedia.org/wiki/Windows%20Embedded%20CE%206.0
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Windows Embedded CE 6.0 (codenamed "Yamazaki") is the sixth major release of the Microsoft Windows embedded operating system targeted to enterprise-specific tools such as industrial controllers and consumer electronics devices like digital cameras. CE 6.0 features a kernel that supports 32,768 processes, up from the 32-process limit of prior versions. Each process receives 2 GB of virtual address space, up from 32 MB. Windows Embedded CE is commonly used in supermarket self-checkouts and cars as a display. Windows Embedded CE is a background system on most devices that have it.
Windows Embedded CE 6.0 was released on November 1, 2006, and includes partial source code. The OS currently serves as the basis for the Zune HD portable media player. Windows Mobile 6.5 is based on Windows CE 5.2. Windows Phone 7, the first major release of the Windows Phone operating system, is based on Windows Embedded CE 6.0 R3; although Windows Phone 7 is also using Windows Embedded Compact 7 features.
New features
Some system components (such as filesystem, GWES (graphics, windowing, events server), device driver manager) have been moved to the kernel space.
The system components which now run in kernel have been converted from EXEs to DLLs, which get loaded into kernel space.
New virtual memory model. The lower 2 GB is the process VM space and is private per process. The upper 2 GB is the kernel VM space.
New device driver model that supports both user mode and kernel mode drivers.
The 32 process limit has been raised to 32,768 processes.
The 32 megabyte virtual memory limit has been raised to the total virtual memory; up to 2 GB of private VM is available per process.
The Platform Builder IDE is integrated into Microsoft Visual Studio 2005 as plugin (thus forcing the client to obtain Microsoft Visual Studio 2005 also), allowing one development environment for both platform and application development.
Read-only support for UDF 2.5 filesystem.
Support for Microsoft's exFAT f
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https://en.wikipedia.org/wiki/Barbarian%20%281987%20video%20game%29
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Barbarian is a 1987 platform game by Psygnosis. It was first developed for the Atari ST, and was ported to the Amiga, Commodore 64, MS-DOS, MSX, Amstrad CPC, and ZX Spectrum. The Amiga port was released in 1987; the others were released in 1988. The cover artwork (part of "Red Dragon" figure/landscape) is by fantasy artist Roger Dean.
The game spawned a 1991 sequel, Barbarian II.
Gameplay
The game opens with a striking—for the era—animation of a muscle-bound barbarian cutting a chain with a sword. On the Amiga and Atari ST versions, the animation is accompanied by a loud, digital sound effect.
In the game, the player is Hegor, a barbarian who must traverse several dungeons and underground habitats to defeat his brother, the evil sorcerer Necron. He has a sword, a shield and bow in his arsenal of weapons. Running and jumping, as with many platform games, comprises a large part of the gameplay of this title.
The game used a unique control system to make up for lack of more than one joystick button on many systems. The player would first press the one button after which a "menu" of actions would appear along the bottom of the screen. The player then selected the desired action by cycling through the choices with the joystick and then pressing the button again when the desired action was highlighted.
In the original versions, this game tried to emulate the visual style of the game cover and opening animation. The game used very detailed and colorful sprites and a variety of thoughtful sound effects to accompany the onscreen action. The IBM PC version plays digitized speech in the opening sequence and other sound effects using the speaker.
Reception
David Plotkin of STart praised Barbarians graphics and sound as "the most impressive I've ever seen in an ST game". He hesitated to recommend the game, however, because the lack of savegame forced restarts after the frequent unavoidable deaths. The game was reviewed in 1989 in Dragon #150 by Courtney Harrington in "The
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https://en.wikipedia.org/wiki/KLV
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KLV (Key-Length-Value) is a data encoding standard, often used to embed information in video feeds. The standard uses a type–length–value encoding scheme. Items are encoded into Key-Length-Value triplets, where key identifies the data, length specifies the data's length, and value is the data itself. It is defined in SMPTE 336M-2007 (Data Encoding Protocol Using Key-Length Value), approved by the Society of Motion Picture and Television Engineers. Due to KLV's large degree of interoperability, it has also been adopted by the Motion Imagery Standards Board.
Byte packing
In a binary stream of data, a KLV set is broken down in the following fashion, with all integer-interpretation being big endian:
Key field
The first few bytes are the Key, much like a key in a standard hash table data structure. Keys can be 1, 2, 4, or 16 bytes in length. Presumably in a separate specification document you would agree on a key length for a given application. Sixteen byte keys are usually reserved for use as globally registered unique identifiers, and the Value portion of such a packet usually contains a series of more KLV sets with smaller keys.
Length field
Following the bytes for the Key are bytes for the Length field which will tell you how many bytes follow the length field and make up the Value portion. There are four kinds of encoding for the Length field: 1-byte, 2-byte, 4-byte and Basic Encoding Rules (BER). The 1-, 2-, and 4-byte variants are pretty straightforward: make an unsigned integer out of the bytes, and that integer is the number of bytes that follow.
BER length encoding is a bit more complicated but the most flexible. If the first byte in the length field does not have the high bit set (0x80), then that single byte represents an integer between 0 and 127 and indicates the number of Value bytes that immediately follows. If the high bit is set, then the lower seven bits indicate how many bytes follow that themselves make up a length field.
For example if the
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https://en.wikipedia.org/wiki/Stan%20Frankel
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Stanley Phillips Frankel (1919 – May, 1978) was an American computer scientist. He worked in the Manhattan Project and developed various computers as a consultant.
Early life
He was born in Los Angeles, attended graduate school at the University of Rochester, received his PhD in physics from the University of California, Berkeley, and began his career as a post-doctoral student under J. Robert Oppenheimer at University of California, Berkeley in 1942.
Career
Frankel helped develop computational techniques used in the nuclear research taking place at the time, notably making some of the early calculations relating to the diffusion of neutrons in a critical assembly of uranium with Eldred Nelson. He joined the T (Theoretical) Division of the Manhattan Project at Los Alamos in 1943. His wife Mary Frankel was also hired to work as a human computer in the T Division. While at Los Alamos, Frankel and Nelson organized a group of scientists' wives, including Mary, to perform some of the repetitive calculations using Marchant and Friden desk calculators to divide the massive calculations required for the project. This became Group T-5 under New York University mathematician Donald Flanders when he arrived in the late summer of 1943.
Mathematician Dana Mitchell noticed that the Marchant calculators broke under heavy use and persuaded Frankel and Nelson to order IBM 601 punched card machines. This experience led to Frankel' interest in the then-dawning field of digital computers. In August 1945, Frankel and Nick Metropolis traveled to the Moore School of Engineering in Pennsylvania to learn how to program the ENIAC computer. That fall they helped design a calculation that would determine the likelihood of being able to develop a fusion weapon. Edward Teller used the ENIAC results to prepare a report in the spring of 1946 that answered this question in the affirmative.
After losing his security clearance (and thus his job) during the red scare of the early 1950s, Franke
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https://en.wikipedia.org/wiki/Construction%20field%20computing
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Construction field computing is the use of handheld devices that augment the construction superintendent's ability to manage the operations on a construction site. These information appliances (IA) must be portable devices which can be carried or worn by the user, and have computational and connectivity capacity to perform the tasks of communication management. Data entry and retrieval must be simple so that the user can manipulate the device while simultaneously moving, observing events, studying materials, checking quality, or performing other tasks required. Examples of these devices are the PDA, tablet PC modern tablet devices including iPad and Android Tablets and smartphone.
Usage of information appliances in construction
Superintendents are often moving about the construction site or between various sites. Their responsibilities cover a wide variety of tasks such as:
Comparing planned to constructed conditions.
Carrying out in-field quality inspections ( punch lists or snagging as it is called in the UK)
Capturing data about such defects and communicating it to the relevant sub-contractors.
Coordinating and scheduling events and material delivery.
Monitoring jobsite conditions and correcting safety deficiencies, improving efficiency, and ensuring quality.
Recording and documenting work progress, labor, inspections, compliance to specifications, etc.
Communicating direction to specialty contractors, laborers, suppliers, etc.
Clarifying plans and specifications, resolving differing conditions, adapting methods and materials to site-specific requirements.
These tasks require that information is readily accessible and easily communicated to others and the company database. Since construction sites are unique, the device and system must be adaptable and flexible. Durability, predictability, and perceived value by the field management will determine the system's acceptance and thus proper use. Construction personnel are not well known for adapting to new tech
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https://en.wikipedia.org/wiki/Kinetic%20inductance
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Kinetic inductance is the manifestation of the inertial mass of mobile charge carriers in alternating electric fields as an equivalent series inductance. Kinetic inductance is observed in high carrier mobility conductors (e.g. superconductors) and at very high frequencies.
Explanation
A change in electromotive force (emf) will be opposed by the inertia of the charge carriers since, like all objects with mass, they prefer to be traveling at constant velocity and therefore it takes a finite time to accelerate the particle. This is similar to how a change in emf is opposed by the finite rate of change of magnetic flux in an inductor. The resulting phase lag in voltage is identical for both energy storage mechanisms, making them indistinguishable in a normal circuit.
Kinetic inductance () arises naturally in the Drude model of electrical conduction considering not only the DC conductivity but also the finite relaxation time (collision time) of the mobile charge carriers when it is not tiny compared to the wave period 1/f. This model defines a complex conductance at radian frequency ω=2πf given by . The imaginary part, -σ2, represents the kinetic inductance. The Drude complex conductivity can be expanded into its real and imaginary components:
where is the mass of the charge carrier (i.e. the effective electron mass in metallic conductors) and is the carrier number density. In normal metals the collision time is typically s, so for frequencies < 100 GHz is very small and can be ignored; then this equation reduces to the DC conductance . Kinetic inductance is therefore only significant at optical frequencies, and in superconductors whose .
For a superconducting wire of cross-sectional area , the kinetic inductance of a segment of length can be calculated by equating the total kinetic energy of the Cooper pairs in that region with an equivalent inductive energy due to the wire's current :
where is the electron mass ( is the mass of a Cooper pair), is the
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https://en.wikipedia.org/wiki/Alkali-metal%20thermal%20to%20electric%20converter
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An alkali-metal thermal-to-electric converter (AMTEC, originally called the sodium heat engine or SHE) is a thermally regenerative electrochemical device for the direct conversion of heat to electrical energy. It is characterized by high potential efficiencies and no moving parts except for the working fluid, which make it a candidate for space power applications.
It was invented by Joseph T. Kummer and Neill Weber at Ford in 1966, and is described in US Patents , , and .
Design
An Alkali-metal thermal to electric converter works by pumping something, usually sodium, though any Alkali metal will do, through, around, and over, a circuit. The heat evaporates the sodium at one end. This puts it at high pressure. It then passes through/over the Anode, releasing electrons, thus, charge. It then passes through an electrolyte to conduct it to the other side. This works because the electrolyte chosen can conduct Ions, but not electrons so well. At the Cathode, the Alkali metal gets its electrons back, effectively pumping electrons through the external circuit. The pressure from the electrolyte pushes it to a low-pressure vapor chamber, where it “cools off” to a liquid again. An electromagnetic pump, or a wick, takes this liquid sodium back to the hot side.
This device accepts a heat input in a range 900–1300 K and produces direct current with predicted device efficiencies of 15–40%. In the AMTEC, sodium is driven around a closed thermodynamic cycle between a high-temperature heat reservoir and a cooler reservoir at the heat rejection temperature. The unique feature of the AMTEC cycle is that sodium ion conduction between a high-pressure or -activity region and a low-pressure or -activity region on either side of a highly ionically conducting refractory solid electrolyte is thermodynamically nearly equivalent to an isothermal expansion of sodium vapor between the same high and low pressures. Electrochemical oxidation of neutral sodium at the anode leads to sodium ions
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https://en.wikipedia.org/wiki/Supine%20position
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The supine position ( or ) means lying horizontally with the face and torso facing up, as opposed to the prone position, which is face down. When used in surgical procedures, it grants access to the peritoneal, thoracic and pericardial regions; as well as the head, neck and extremities.
Using anatomical terms of location, the dorsal side is down, and the ventral side is up, when supine.
Semi-supine
In scientific literature "semi-supine" commonly refers to positions where the upper body is tilted (at 45° or variations) and not completely horizontal.
Relation to sudden infant death syndrome
The decline in death due to sudden infant death syndrome (SIDS) is said to be attributable to having babies sleep in the supine position. The realization that infants sleeping face down, or in a prone position, had an increased mortality rate re-emerged into medical awareness at the end of the 1980s when two researchers, Susan Beal in Australia and Gus De Jonge in the Netherlands, independently noted the association.
It is believed that in the prone position babies are more at risk to re-breathe their own carbon dioxide. Because of the immature state of their central chemoreceptors, infants do not respond to the subsequent respiratory acidosis that develops. Typical non-infants realize autonomic responses of increased rate and depth of respiration (hyperventilation, yawning).
Obstructive sleep apnea
Obstructive sleep apnea (OSA) is a form of sleep apnea that occurs more frequently when throat muscles relax and is most severe when individuals are sleeping in the supine position. Studies and evidence show that OSA related to sleeping in the supine position is related to the airway positioning, reduced lung volume, and the inability of airway muscles to dilate enough to compensate as the airway collapses. With individuals who have OSA, many health care providers encourage their patients to avoid the supine position while asleep and sleep laterally or sleep with the head of th
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https://en.wikipedia.org/wiki/Complex%20Hadamard%20matrix
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A complex Hadamard matrix is any complex
matrix satisfying two conditions:
unimodularity (the modulus of each entry is unity):
orthogonality: ,
where denotes the Hermitian transpose of and is the identity matrix. The concept is a generalization of the Hadamard matrix. Note that any complex Hadamard matrix can be made into a unitary matrix by multiplying it by ; conversely, any unitary matrix whose entries all have modulus becomes a complex Hadamard upon multiplication by .
Complex Hadamard matrices arise in the study of operator algebras and the theory of quantum computation. Real Hadamard matrices and Butson-type Hadamard matrices form particular cases of complex Hadamard matrices.
Complex Hadamard matrices exist for any natural (compare the real case, in which existence is not known for every ). For instance the Fourier matrices (the complex conjugate of the DFT matrices without the normalizing factor),
belong to this class.
Equivalency
Two complex Hadamard matrices are called equivalent, written , if there exist diagonal unitary matrices and permutation matrices
such that
Any complex Hadamard matrix is equivalent to a dephased Hadamard matrix, in which all elements in the first row and first column are equal to unity.
For and all complex Hadamard matrices are equivalent to the Fourier matrix . For there exists
a continuous, one-parameter family of inequivalent complex Hadamard matrices,
For the following families of complex Hadamard matrices
are known:
a single two-parameter family which includes ,
a single one-parameter family ,
a one-parameter orbit , including the circulant Hadamard matrix ,
a two-parameter orbit including the previous two examples ,
a one-parameter orbit of symmetric matrices,
a two-parameter orbit including the previous example ,
a three-parameter orbit including all the previous examples ,
a further construction with four degrees of freedom, , yielding other examples than ,
a single point - one
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https://en.wikipedia.org/wiki/Claire%20F.%20Gmachl
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Claire F. Gmachl is the Eugene Higgins Professor of Electrical Engineering at Princeton University. She is best known for her work in the development of quantum cascade lasers.
Education and honors
Gmachl earned her M.Sc. in physics from the University of Innsbruck in 1991. She went on to receive her Ph.D. in electrical engineering from the Technical University of Vienna in 1995, graduating sub auspiciis Praesidentis (with special honors by the president of the Austrian republic). Her studies focused on integrated optical modulators and tunable surface-emitting lasers in the near infrared. From 1996 to 1998, she was a postdoctoral member of technical staff at Bell Laboratories. In 1998, she became a formal member of technical staff at Bell Labs and in 2002 she was named a distinguished member of technical staff, in part due to her work on the development of the quantum cascade laser. In 2003, she left Bell Labs and took a position as associate professor in the department of electrical engineering at Princeton University, where she is currently working as a full professor since 2007.
In 2004, Popular Science named Gmachl in its "Class of 2004 - Brilliant 10," its list of the 10 most promising scientists under 40. She went on, in September 2005, to win the MacArthur Foundation's "genius grant." Recently, she was named the director of the new Mid-InfraRed Technologies for Health and the Environment (MIRTHE) Center, funded by the National Science Foundation.
Gmachl succeeded Sandra Bermann as head of Whitman College, Princeton University on July 1, 2019.
Research
Although Gmachl originally intended to study theoretical applied mathematics, her interest soon turned to theoretical applied physics, and, with the encouragement of an advisor, experimental sciences. As such, she works in the fields of optics and semiconductor laser technology. Gmachl has conceived several novel designs for solid-state lasers and her work has led to advances in the development of q
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https://en.wikipedia.org/wiki/Tacit%20programming
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Tacit programming, also called point-free style, is a programming paradigm in which function definitions do not identify the arguments (or "points") on which they operate. Instead the definitions merely compose other functions, among which are combinators that manipulate the arguments. Tacit programming is of theoretical interest, because the strict use of composition results in programs that are well adapted for equational reasoning. It is also the natural style of certain programming languages, including APL and its derivatives, and concatenative languages such as Forth. The lack of argument naming gives point-free style a reputation of being unnecessarily obscure, hence the epithet "pointless style".
Unix scripting uses the paradigm with pipes.
Examples
Python
Tacit programming can be illustrated with the following Python code. A sequence of operations such as the following:
def example(x):
return baz(bar(foo(x)))
... can be written in point-free style as the composition of a sequence of functions, without parameters:
from functools import partial, reduce
def compose(*fns):
return partial(reduce, lambda v, fn: fn(v), fns)
example = compose(foo, bar, baz)
For a more complex example, the Haskell code can be translated as:
p = partial(compose, partial(compose, f), g)
Functional programming
A simple example (in Haskell) is a program which computes the sum of a list of numbers. We can define the sum function recursively using a pointed style (cf. value-level programming) as:
sum (x:xs) = x + sum xs
sum [] = 0
However, using a fold we can replace this with:
sum xs = foldr (+) 0 xs
And then the argument is not needed, so this simplifies to
sum = foldr (+) 0
which is point-free.
Another example uses function composition:
p x y z = f (g x y) z
The following Haskell-like pseudo-code exposes how to reduce a function definition to its point-free equivalent:
p = \x -> \y -> \z -> f (g x y) z
= \x -> \y -> f (g x y)
= \x -> \y -> (f . (g x)) y
= \x
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https://en.wikipedia.org/wiki/Chine%20%28boating%29
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A chine in boat design is a sharp change in angle in the cross section of a hull. The chine typically arises from the use of sheet materials (such as sheet metal or marine ply) as the mode of construction.
Rationale of chines
Using sheet materials in boat construction is cheap and simple, but whereas these sheet materials are flexible longitudinally, they tend to be rigid vertically. Examples of steel vessels with hard chines include narrowboats and widebeams; examples of plywood vessels with hard chines include sailing dinghies such as the single-chined Graduate and the double-chined Enterprise. Although a hull made from sheet materials might be unattractively "slab-sided", most chined hulls are designed to be pleasing to the eye and hydrodynamically efficient.
Hulls without chines (such as clinker-built or carvel-built vessels) usually have a gradually curving cross section.
A hard chine is an angle with little rounding, where a soft chine would be more rounded, but still involve the meeting of distinct planes. Chine log construction is a method of building hard chine boat hulls. Hard chines are common in plywood hulls, while soft chines are often found on fiberglass hulls.
Traditional planked hulls in most cultures are built by placing wooden planks oriented parallel to the waterflow and attached to bent wooden frames. This also produced a rounded hull, generally with a sharp bottom edge to form the keel. Planked boats were built in this manner for most of history.
The first hulls to start incorporating hard chines were probably shallow draft cargo carrying vessels used on rivers and in canals.
Once sufficiently powerful marine motors had been developed to allow powerboats to plane, it was found that the flat underside of a chined boat provided maximum hydrodynamic lift and speed.
Boats using chines
The scow in particular, in the form of the scow schooner, was the first significant example of a hard chine sailing vessel. While sailing scows had a po
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https://en.wikipedia.org/wiki/Gramme%20machine
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A Gramme machine, Gramme ring, Gramme magneto, or Gramme dynamo is an electrical generator that produces direct current, named for its Belgian inventor, Zénobe Gramme, and was built as either a dynamo or a magneto. It was the first generator to produce power on a commercial scale for industry. Inspired by a machine invented by Antonio Pacinotti in 1860, Gramme was the developer of a new induced rotor in form of a wire-wrapped ring (Gramme ring) and demonstrated this apparatus to the Academy of Sciences in Paris in 1871. Although popular in 19th century electrical machines, the Gramme winding principle is no longer used since it makes inefficient use of the conductors. The portion of the winding on the interior of the ring cuts no flux and does not contribute to energy conversion in the machine. The winding requires twice the number of turns and twice the number of commutator bars as an equivalent drum-wound armature.
Description
The Gramme machine used a ring armature, with a series of armature coils, wound around a revolving ring of soft iron. The coils are connected in series, and the junction between each pair is connected to a commutator on which two brushes run. Permanent magnets magnetize the soft iron ring, producing a magnetic field which rotates around through the coils in order as the armature turns. This induces a voltage in two of the coils on opposite sides of the armature, which is picked off by the brushes.
Earlier electromagnetic machines passed a magnet near the poles of one or two electromagnets, or rotated coils wound on double-T armatures within a static magnetic field, creating brief spikes or pulses of DC resulting in a transient output of low average power, rather than a constant output of high average power.
With more than a few coils on the Gramme ring armature, the resulting voltage waveform is practically constant, thus producing a near direct current supply. This type of machine needs only electromagnets producing the magnetic field
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https://en.wikipedia.org/wiki/Pulse%20transition%20detector
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A Pulse transition detector is used in flip flops in order to achieve edge triggering in the circuit. It merely converts the clock signal's rising edge to a very narrow pulse.
The PTD consists of a delay gate (which delays the clock signal) and the clock signal itself passed through a NAND gate and then inverted.
The benefit of edge triggering is that it removes the problems of zeroes and ones catching associated with pulse triggered flipflops (e.g. master slave flip flops).
Logic gates
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https://en.wikipedia.org/wiki/Cryptographic%20module
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A cryptographic module is a component of a computer system that implements cryptographic algorithms in a secure way, typically with some element of tamper resistance.
NIST defines a cryptographic modules as "The set of hardware, software, and/or firmware that implements security functions (including cryptographic algorithms), holds plaintext keys and uses them for performing cryptographic operations, and is contained within a cryptographic module boundary."
Hardware security modules, including secure cryptoprocessors, are one way of implementing cryptographic modules.
Standards for cryptographic modules include FIPS 140-3 and ISO/IEC 19790.
References
See also
Cryptographic Module Validation Program (CMVP)
Cryptographic Module Testing Laboratory
Cryptography
Computer security
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