source
stringlengths 31
203
| text
stringlengths 28
2k
|
|---|---|
https://en.wikipedia.org/wiki/Devicescape
|
Devicescape is an American developer of client/server software services for wireless networking connectivity, analytics, and context-awareness. Founded in 2001 as Instant802 Networks, the company was renamed to Devicescape in January 2005. Devicescape is a venture backed private company.
Corporate History
Instant802 Networks was founded in 2001 by Eduardo de-Castro and Roy Petruschka in San-Francisco, and Simon Barber had joined as a third founder a few months after company incorporation.
In 2004 the company began development of packaged software products, including security for emerging devices and complete access point packages. The software was used in devices ranging from LCD projectors, televisions and digital video recorders to PDAs and SOHO access points. The company also provided software for the Wi-Fi Alliance test bed.
Dave Fraser joined as CEO in 2004, and in 2005 the company was renamed Devicescape Software. The company continued to develop additional client security products.
In 2006, Devicescape exited the access point business by licensing its Wireless Infrastructure Platform technology to LVL7, which was subsequently sold to Broadcom.
In 2007, Devicescape contributes a new wireless stack to the Linux kernel.
In 2007, Devicescape introduced Connect, a client-server system which allowed embedded devices to automatically authenticate against a large number of public Wi-Fi networks. The company released a variety of consumer applications for PCs and smartphones under the Devicescape Easy Wi-Fi brand. In 2009, Devicescape launched the Easy WiFi Network.
In 2010, Devicescape applied server-based analysis to curate Wi-Fi networks discovered by client applications, so that Wi-Fi networks could be assessed for quality, location, sharing status and other factors. The company referred to this as a "Curated Virtual Network" (CVN) and became a mechanism for offloading traffic from cellular networks. Late in 2010, MetroPCS (now T-Mobile) became the firs
|
https://en.wikipedia.org/wiki/Hostapd
|
hostapd (host access point daemon) is a user space daemon software enabling a network interface card to act as an access point and authentication server. There are three implementations: Jouni Malinen's hostapd, OpenBSD's hostapd and Devicescape's hostapd.
Jouni Malinen's hostapd
Jouni Malinen's hostapd is a user space daemon for access point and authentication servers. It can be used to create a wireless hotspot using a Linux computer. It implements IEEE 802.11 access point management, IEEE 802.1X/WPA/WPA2/EAP Authenticators, RADIUS client, EAP server, and RADIUS authentication server. The current version supports Linux (Host AP, MadWifi, Prism54 and some of the drivers which use the kernel's mac80211 subsystem), QNX, FreeBSD (net80211), and DragonFlyBSD.
OpenBSD's hostapd
OpenBSD's hostapd is a user space daemon that helps to improve roaming and monitoring of OpenBSD-based wireless networks. It implements Inter Access Point Protocol (IAPP) for exchanging station association information between access points. It can trigger a set of actions like frame injection or logging when receiving specified IEEE 802.11 frames.
Devicescape's hostapd
The Open Wireless Linux version of hostapd. It is kept as close as possible to the original open source release, but with OWL specific packaging and defaults.
The website appears to be dead (April 2013), probably as the project itself.
See also
HostAP
References
External links
DragonFlyBSD commit
Undeadly Article
Wi-Fi
OpenBSD
|
https://en.wikipedia.org/wiki/Data%20access%20layer
|
A data access layer (DAL) in computer software is a layer of a computer program which provides simplified access to data stored in persistent storage of some kind, such as an entity-relational database. This acronym is prevalently used in Microsoft environments.
For example, the DAL might return a reference to an object (in terms of object-oriented programming) complete with its attributes instead of a row of fields from a database table. This allows the client (or user) modules to be created with a higher level of abstraction. This kind of model could be implemented by creating a class of data access methods that directly reference a corresponding set of database stored procedures. Another implementation could potentially retrieve or write records to or from a file system. The DAL hides this complexity of the underlying data store from the external world.
For example, instead of using commands such as insert, delete, and update to access a specific table in a database, a class and a few stored procedures could be created in the database. The procedures would be called from a method inside the class, which would return an object containing the requested values. Or, the insert, delete and update commands could be executed within simple functions like registeruser or loginuser stored within the data access layer.
Also, business logic methods from an application can be mapped to the data access layer. So, for example, instead of making a query into a database to fetch all users from several tables, the application can call a single method from a DAL which abstracts those database calls.
Applications using a data access layer can be either database server dependent or independent. If the data access layer supports multiple database types, the application becomes able to use whatever databases the DAL can talk to. In either circumstance, having a data access layer provides a centralized location for all calls into the database, and thus makes it easier to port t
|
https://en.wikipedia.org/wiki/Briggs%E2%80%93Rauscher%20reaction
|
The Briggs–Rauscher oscillating reaction is one of a small number of known oscillating chemical reactions. It is especially well suited for demonstration purposes because of its visually striking colour changes: the freshly prepared colourless solution slowly turns an amber colour, then suddenly changes to a very dark blue. This slowly fades to colourless and the process repeats, about ten times in the most popular formulation, before ending as a dark blue liquid smelling strongly of iodine.
History
The first known homogeneous oscillating chemical reaction, reported by W. C. Bray in 1921, was between hydrogen peroxide (H2O2) and iodate () in acidic solution. Because of experimental difficulty, it attracted little attention and was unsuitable as a demonstration. In 1958 Boris Pavlovich Belousov discovered the Belousov–Zhabotinsky reaction (BZ reaction). The BZ reaction is suitable as a demonstration, but it too met with skepticism, largely because such oscillatory behaviour was unheard of up to that time, until Anatol Zhabotinsky learned of it and in 1964 published his research. In May 1972 a pair of articles in the Journal of Chemical Education brought it to the attention of Thomas Briggs and Warren Rauscher, two science instructors at Galileo High School in San Francisco. They discovered the Briggs–Rauscher oscillating reaction by replacing bromate () in the BZ reaction with iodate and adding hydrogen peroxide. They produced the strikingly colorful demonstration by adding starch indicator. Since then, many other investigators have added to the knowledge and uses of this very unusual reaction.
Description
Initial conditions
The initial aqueous solution contains hydrogen peroxide, an iodate, divalent manganese (Mn2+) as catalyst, a strong chemically unreactive acid (sulphuric acid (H2SO4) or perchloric acid (HClO4) are good), and an organic compound with an active ("enolic") hydrogen atom attached to carbon which will slowly reduce free iodine (I2) to iodide (I−).
|
https://en.wikipedia.org/wiki/List%20of%20random%20number%20generators
|
Random number generators are important in many kinds of technical applications, including physics, engineering or mathematical computer studies (e.g., Monte Carlo simulations), cryptography and gambling (on game servers).
This list includes many common types, regardless of quality or applicability to a given use case.
Pseudorandom number generators (PRNGs)
The following algorithms are pseudorandom number generators.
Cryptographic algorithms
Cipher algorithms and cryptographic hashes can be used as very high-quality pseudorandom number generators. However, generally they are considerably slower (typically by a factor 2–10) than fast, non-cryptographic random number generators.
These include:
Stream ciphers. Popular choices are Salsa20 or ChaCha (often with the number of rounds reduced to 8 for speed), ISAAC, HC-128 and RC4.
Block ciphers in counter mode. Common choices are AES (which is very fast on systems supporting it in hardware), TwoFish, Serpent and Camellia.
Cryptographic hash functions
A few cryptographically secure pseudorandom number generators do not rely on cipher algorithms but try to link mathematically the difficulty of distinguishing their output from a `true' random stream to a computationally difficult problem. These approaches are theoretically important but are too slow to be practical in most applications. They include:
Blum–Micali algorithm (1984)
Blum Blum Shub (1986)
Naor–Reingold pseudorandom function (1997)
Random number generators that use external entropy
These approaches combine a pseudo-random number generator (often in the form of a block or stream cipher) with an external source of randomness (e.g., mouse movements, delay between keyboard presses etc.).
/dev/random – Unix-like systems
CryptGenRandom – Microsoft Windows
Fortuna
RDRAND instructions (called Intel Secure Key by Intel), available in Intel x86 CPUs since 2012. They use the AES generator built into the CPU, reseeding it periodically.
True Random Number Gen
|
https://en.wikipedia.org/wiki/Float%20switch
|
A float switch is a type of level sensor, a device used to detect the level of liquid within a tank. The switch may be used to control a pump, as an indicator, an alarm, or to control other devices.
One type of float switch uses a mercury switch inside a hinged float. Another common type is a float that raises a rod to actuate a microswitch. One pattern uses a reed switch mounted in a tube; a float, containing a magnet, surrounds the tube and is guided by it. When the float raises the magnet to the reed switch, it closes. Several reeds can be mounted in the tube for different level indications by one assembly.
A very common application is in sump pumps and condensate pumps where the switch detects the rising level of liquid in the sump or tank and energizes an electrical pump which then pumps liquid out until the level of the liquid has been substantially reduced, at which point the pump is switched off again. Float switches are often adjustable and can include substantial hysteresis. That is, the switch's "turn on" point may be much higher than the "shut off" point. This minimizes the on-off cycling of the associated pump.
Some float switches contain a two-stage switch. As liquid rises to the trigger point of the first stage, the associated pump is activated. If the liquid continues to rise (perhaps because the pump has failed or its discharge is blocked), the second stage will be triggered. This stage may switch off the source of the liquid being pumped, trigger an alarm, or both.
Where level must be sensed inside a pressurized vessel, often a magnet is used to couple the motion of the float to a switch located outside the pressurized volume. In some cases, a rod through a stuffing box can be used to operate a switch, but this creates high drag and has a potential for leakage. Successful float switch installations minimize the opportunity for accumulation of dirt on the float that would impede its motion. Float switch materials are selected to resist the de
|
https://en.wikipedia.org/wiki/Sight%20glass
|
A sight glass or water gauge is a type of level sensor, a transparent tube through which the operator of a tank or boiler can observe the level of liquid contained within.
Liquid in tanks
Simple sight glasses may be just a plastic or glass tube connected to the bottom of the tank at one end and the top of the tank at the other. The level of liquid in the sight glass will be the same as the level of liquid in the tank. Today, however, sophisticated float switches have replaced sight glasses in many such applications.
Steam boilers
If the liquid is hazardous or under pressure, more sophisticated arrangements must be made. In the case of a boiler, the pressure of the water below and the steam above is equal, so any change in the water level will be seen in the gauge. The transparent tube (the “glass” itself) may be mostly enclosed within a metal or toughened glass shroud to prevent it from being damaged through scratching or impact and offering protection to the operators in the case of breakage. This usually has a patterned backplate to make the magnifying effect of the water in the tube more obvious and so allow for easier reading. In some locomotives where the boiler is operated at very high pressures, the tube itself would be made of metal-reinforced toughened glass. It is important to keep the water at the specified level, otherwise the top of the firebox will be exposed, creating an overheat hazard and causing damage and possibly catastrophic failure.
To check that the device is offering a correct reading and the connecting pipes to the boiler are not blocked by scale, the water level needs to be “bobbed” by quickly opening the taps in turn and allowing a brief spurt of water through the drain cock.
The National Board of Boiler and Pressure Vessel Inspectors recommends a daily testing procedure described by the American National Standards Institute, chapter 2 part I-204.3 water level gauge. While not strictly required, this procedure is designed to allow a
|
https://en.wikipedia.org/wiki/Invariant-based%20programming
|
Invariant-based programming is a programming methodology where specifications and invariants are written before the actual program statements. Writing down the invariants during the programming process has a number of advantages: it requires the programmer to make their intentions about the program behavior explicit before actually implementing it, and invariants can be evaluated dynamically during execution to catch common programming errors. Furthermore, if strong enough, invariants can be used to prove the correctness of the program based on the formal semantics of program statements. A combined programming and specification language, connected to a powerful formal proof system, will generally be required for full verification of non-trivial programs. In this case a high degree of automation of proofs is also possible.
In most existing programming languages the main organizing structures are control flow blocks such as for loops, while loops and if statements. Such languages may not be ideal for invariants-first programming, since they force the programmer to make decisions about control flow before writing the invariants. Furthermore, most programming languages do not have good support for writing specifications and invariants, since they lack quantifier operators and one can typically not express higher order properties.
The idea of developing the program together with its proof originated from E.W. Dijkstra. Actually writing invariants before program statements has been considered in a number of different forms by M.H. van Emden, J.C. Reynolds and R-J Back.
See also
Eiffel (programming language)
Notes
Formal methods
Programming paradigms
|
https://en.wikipedia.org/wiki/Full%20custom
|
In integrated circuit design, full-custom is a design methodology in which the layout of each individual transistor on the integrated circuit (IC), and the interconnections between them, are specified. Alternatives to full-custom design include various forms of semi-custom design, such as the repetition of small transistor subcircuits; one such methodology is the use of standard cell libraries (which are themselves designed full-custom).
Full-custom design potentially maximizes the performance of the chip, and minimizes its area, but is extremely labor-intensive to implement. Full-custom design is limited to ICs that are to be fabricated in extremely high volumes, notably certain microprocessors and a small number of application-specific integrated circuits (ASICs).
As of 2008 the main factor affecting the design and production of ASICs was the high cost of mask sets (number of which is depending on the number of IC layers) and the requisite EDA design tools. The mask sets are required in order to transfer the ASIC designs onto the wafer.
See also
Electronics design flow
References
Integrated circuits
|
https://en.wikipedia.org/wiki/Hybrid%20bond%20graph
|
A hybrid bond graph is a graphical description of a physical dynamic system with discontinuities (i.e., a hybrid dynamical system). Similar to
a regular bond graph, it is an energy-based technique. However, it allows instantaneous switching of the junction structure, which may violate the principle of continuity of power (Mosterman and Biswas, 1998).
References
Pieter Mosterman and Gautam Biswas, 1998: "A Theory of Discontinuities in Physical System Models" in Journal of the Franklin Institute, Volume 335B, Number 3, pp. 401-439, January, 1998.
Further reading
Pieter Mosterman, 2001: "HyBrSim - A Modeling and Simulation Environment for Hybrid Bond Graphs" in Journal of Systems and Control Engineering, vol. 216, Part I, pp. 35-46, 2002.
Cuijpers, P.J.L., Broenink, J.F., and Mosterman P.J., 2008: "Constitutive Hybrid Processes: a Process-Algebraic Semantics for Hybrid Bond Graphs" in SIMULATION, vol. 84, No. 7, pages 339-358, 2008.
Bond graph
|
https://en.wikipedia.org/wiki/Standard%20of%20Good%20Practice%20for%20Information%20Security
|
The Standard of Good Practice for Information Security (SOGP), published by the Information Security Forum (ISF), is a business-focused, practical and comprehensive guide to identifying and managing information security risks in organizations and their supply chains.
The most recent edition is 2020, an update of the 2018 edition. A 2022 edition is coming.
Upon release, the 2011 Standard was the most significant update of the standard for four years. It covers information security 'hot topics' such as consumer devices, critical infrastructure, cybercrime attacks, office equipment, spreadsheets and databases and cloud computing.
The 2011 Standard is aligned with the requirements for an Information Security Management System (ISMS) set out in ISO/IEC 27000-series standards, and provides wider and deeper coverage of ISO/IEC 27002 control topics, as well as cloud computing, information leakage, consumer devices and security governance.
In addition to providing a tool to enable ISO 27001 certification, the 2011 Standard provides full coverage of COBIT v4 topics, and offers substantial alignment with other relevant standards and legislation such as PCI DSS and the Sarbanes Oxley Act, to enable compliance with these standards too.
The Standard is used by Chief Information Security Officers (CISOs), information security managers, business managers, IT managers, internal and external auditors, IT service providers in organizations of all sizes.
The 2018 Standard is available free of charge to members of the ISF. Non-members are able to purchase a copy of the standard directly from the ISF.
Organization
The Standard has historically been organized into six categories, or aspects. Computer Installations and Networks address the underlying IT infrastructure on which Critical Business Applications run. The End-User Environment covers the arrangements associated with protecting corporate and workstation applications at the endpoint in use by individuals. Systems Developme
|
https://en.wikipedia.org/wiki/Glossary%20of%20machine%20vision
|
The following are common definitions related to the machine vision field.
General related fields
Machine vision
Computer vision
Image processing
Signal processing
0-9
1394. FireWire is Apple Inc.'s brand name for the IEEE 1394 interface. It is also known as i.Link (Sony's name) or IEEE 1394 (although the 1394 standard also defines a backplane interface). It is a personal computer (and digital audio/digital video) serial bus interface standard, offering high-speed communications and isochronous real-time data services.
1D. One-dimensional.
2D computer graphics. The computer-based generation of digital images—mostly from two-dimensional models (such as 2D geometric models, text, and digital images) and by techniques specific to them.
3D computer graphics. 3D computer graphics are different from 2D computer graphics in that a three-dimensional representation of geometric data is stored in the computer for the purposes of performing calculations and rendering 2D images. Such images may be for later display or for real-time viewing. Despite these differences, 3D computer graphics rely on many of the same algorithms as 2D computer vector graphics in the wire frame model and 2D computer raster graphics in the final rendered display. In computer graphics software, the distinction between 2D and 3D is occasionally blurred; 2D applications may use 3D techniques to achieve effects such as lighting, and primarily 3D may use 2D rendering techniques.
3D scanner. This is a device that analyzes a real-world object or environment to collect data on its shape and possibly color. The collected data can then be used to construct digital, three dimensional models useful for a wide variety of applications.
A
Aberration. Optically, defocus refers to a translation along the optical axis away from the plane or surface of best focus. In general, defocus reduces the sharpness and contrast of the image. What should be sharp, high-contrast edges in a scene become gradual transiti
|
https://en.wikipedia.org/wiki/Global%20Buddhist%20Network
|
The Global Buddhist Network (GBN), previously known as the Dhammakaya Media Channel (DMC) is a Thai online television channel concerned with Buddhism. The channel's taglines were "The secrets of life revealed" and "The only one", but these were later replaced by "Channel for the path to the cessation of suffering and attainment of Dhamma". The channel features many types of programs with Buddhist content, and has programs in several languages.
The channel started in 2002, as a means to reach remote provinces in Thailand. Controversially, the channel made international headlines in 2012 when it featured a teaching on the afterlife of Steve Jobs. On 26 December 2016, Thai authorities withdrew the permit for the satellite channel permanently, during the legal investigations into the temple by the Thai junta. In April 2017, it was reported, however, that the channel's programming had continued, but broadcast through the Internet only. In its online format, the channel has been renamed Global Buddhist Network.
Background
DMC started in 2002. The channel was owned by the Dhamma Research for Environment Foundation, part of the temple Wat Phra Dhammakaya. The channel was founded to provide an alternative to the many distractions that surround people in modern life, which lure "people into doing immoral things", as stated by Phra Somsak Piyasilo, spokesperson of the organization. The channel originated from an initiative in 2001 when people living in the far provinces of Thailand wanted to listen to the teachings of the temple. The temple therefore provided live teachings through a thousand public telephone lines, through which people could follow the activities. The telephone lines had many restrictions in use, and the temple started to broadcast through a satellite television channel instead. Later, in 2005, the temple developed an online counterpart to the channel.
The channel is managed by Phra Maha Nopon Puññajayo, who supervises a team of thirty volunteers. Previou
|
https://en.wikipedia.org/wiki/Isoamyl%20acetate
|
Isoamyl acetate, also known as isopentyl acetate, is an organic compound that is the ester formed from isoamyl alcohol and acetic acid, with the molecular formula C7H14O2. It is a colorless liquid that is only slightly soluble in water, but very soluble in most organic solvents. Isoamyl acetate has a strong odor which is described as similar to both banana and pear. Pure isoamyl acetate, or mixtures of isoamyl acetate, amyl acetate, and other flavors in ethanol may be referred to as banana oil or pear oil.
Production
Isoamyl acetate is prepared by the acid catalyzed reaction (Fischer esterification) between isoamyl alcohol and glacial acetic acid as shown in the reaction equation below. Typically, sulfuric acid is used as the catalyst. Alternatively, p-toluenesulfonic acid or an acidic ion exchange resin can be used as the catalyst.
It is also produced synthetically by the rectification of amyl acetate.
Applications
Isoamyl acetate is used to confer banana or pear flavor in foods such as circus peanuts, Juicy Fruit and pear drops. Banana oil and pear oil commonly refer to a solution of isoamyl acetate in ethanol that is used as an artificial flavor.
It is also used as a solvent for some varnishes, oil paints, and nitrocellulose lacquers. As a solvent and carrier for materials such as nitrocellulose, it was extensively used in the aircraft industry for stiffening and wind-proofing fabric flying surfaces, where it and its derivatives were generally known as 'aircraft dope'. Now that most aircraft wings are made of metal, such use is mostly limited to historically accurate reproductions and scale models.
Because of its intense, pleasant odor and its low toxicity, isoamyl acetate is used to test the effectiveness of respirators or gas masks.
Occurrence in nature
Isoamyl acetate occurs naturally in many plants, including apple, banana, coffee, grape, guava, lychee, papaya, peach, pomegranate, and tomato. It is also released by fermentation processes, including t
|
https://en.wikipedia.org/wiki/OutSystems
|
OutSystems is a Low-code development platform which provides tools for companies to develop, deploy and manage omnichannel enterprise applications.
OutSystems was founded in 2001 in Lisbon, Portugal.
In June 2018 OutSystems secured a $360M round of funding from KKR and Goldman Sachs and reached the status of Unicorn.
In February 2021 OutSystems raised another $150M investment from a round co-led by Abdiel Capital and Tiger Global Management, having a total valuation of $9.5 Billion.
OutSystems is a member of the Consortium of IT Software Quality (CISQ).
Products
OutSystems is a low-code development platform for the development of mobile and web enterprise applications, which run in the cloud, on-premises or in hybrid environments.
In 2014 OutSystems launched a free version of the platform that provides developers with personal cloud environments to create and deploy web and mobile applications without charge. The current version is 11.53, for both the paid and unpaid versions.
References
External links
Cloud computing providers
Cloud platforms
2001 establishments in Portugal
Low Code Application Platform
|
https://en.wikipedia.org/wiki/Supporting%20hyperplane
|
In geometry, a supporting hyperplane of a set in Euclidean space is a hyperplane that has both of the following two properties:
is entirely contained in one of the two closed half-spaces bounded by the hyperplane,
has at least one boundary-point on the hyperplane.
Here, a closed half-space is the half-space that includes the points within the hyperplane.
Supporting hyperplane theorem
This theorem states that if is a convex set in the topological vector space and is a point on the boundary of then there exists a supporting hyperplane containing If ( is the dual space of , is a nonzero linear functional) such that for all , then
defines a supporting hyperplane.
Conversely, if is a closed set with nonempty interior such that every point on the boundary has a supporting hyperplane, then is a convex set, and is the intersection of all its supporting closed half-spaces.
The hyperplane in the theorem may not be unique, as noticed in the second picture on the right. If the closed set is not convex, the statement of the theorem is not true at all points on the boundary of as illustrated in the third picture on the right.
The supporting hyperplanes of convex sets are also called tac-planes or tac-hyperplanes.
The forward direction can be proved as a special case of the separating hyperplane theorem (see the page for the proof). For the converse direction,
See also
Support function
Supporting line (supporting hyperplanes in )
Notes
References & further reading
Convex geometry
Functional analysis
Duality theories
|
https://en.wikipedia.org/wiki/Active%20chromatin%20sequence
|
An active chromatin sequence (ACS) is a region of DNA in a eukaryotic chromosome in which histone modifications such as acetylation lead to exposure of the DNA sequence thus allowing binding of transcription factors and transcription to take place. Active chromatin may also be called euchromatin. ACSs may occur in non-expressed gene regions which are assumed to be "poised" for transcription. The sequence once exposed often contains a promoter to begin transcription. At this site acetylation or methylation can take place causing a conformational change to the chromatin. At the active chromatin sequence site deacetylation can caused the gene to be repressed if not being expressed.
See also
Chromatin
References
Genetics
|
https://en.wikipedia.org/wiki/Pot-in-pot%20refrigerator
|
A pot-in-pot refrigerator, clay pot cooler or zeer () is an evaporative cooling refrigeration device which does not use electricity. It uses a porous outer clay pot (lined with wet sand) containing an inner pot (which can be glazed to prevent penetration by the liquid) within which the food is placed. The evaporation of the outer liquid draws heat from the inner pot. The device can cool any substance, and requires only a flow of relatively dry air and a source of water.
History
Many clay pots from around 3000 BC were discovered in the Indus Valley civilization and are considered to have been used for cooling as well as storing water. The pots are similar to the present-day ghara and matki used in India and Pakistan.
There is evidence that evaporative cooling may have been used in North Africa as early as the Old Kingdom of Egypt, circa 2500 BC. Frescoes show slaves fanning water jars, which would increase air flow around porous jars to aid evaporation and cooling the contents. These jars exist even today and are called zeer, hence the name of the pot cooler. Despite being developed in Northern Africa, the technology appeared to have been forgotten since the advent of modern electrical refrigerators.
However, in the Indian subcontinent, ghara, matka and surahi, all of which are different types of clay water pots, are in everyday use to cool water. In Spain, botijos are popular. A botijo is a porous clay container used to keep and to cool water; they have been in use for centuries and are still in relatively widespread use. Botijos are favored most by the low Mediterranean climate; locally, the cooling effect is known as "botijo effect".
In the 1890s, gold miners in Australia developed the Coolgardie safe, based on the same principles.
In rural northern Nigeria in the 1990s, Mohamed Bah Abba developed the Pot-in-Pot Preservation Cooling System, consisting of a small clay pot placed inside a larger one, and the space between the two filled with moist sand. The i
|
https://en.wikipedia.org/wiki/Round-trip%20translation
|
Round-trip translation (RTT), also known as back-and-forth translation, recursive translation and bi-directional translation, is the process of translating a word, phrase or text into another language (forward translation), then translating the result back into the original language (back translation), using machine translation (MT) software. It is often used by laypeople to evaluate a machine translation system, or to test whether a text is suitable for MT when they are unfamiliar with the target language. Because the resulting text can often differ substantially from the original, RTT can also be a source of entertainment.
Software quality
To compare the quality of different machine translation systems, users perform RTT and compare the resulting text to the original. The theory is that the closer the result of the RTT is to the original text, the higher the quality of the machine translation system. One of the problems with this technique is that if there is a problem with the resulting text it is impossible to know whether the error occurred in the forward translation, in the back translation, or in both. In addition, it is possible to get a good back translation from a bad forward translation. A study using the automatic evaluation methods BLEU and F-score compared five different free online translation programs, evaluating the quality of both the forward translation and the back translation, and found no correlation between the quality of the forward translation and the quality of the back translation (i.e., a high quality forward translation did not always correspond to a high quality back translation). The author concluded that RTT was a poor method of predicting the quality of machine translation software. This conclusion was reinforced by a more in-depth study also using automatic evaluation methods. A subsequent study which included human evaluation of the back translation in addition to automatic evaluation methods found that RTT might have some abili
|
https://en.wikipedia.org/wiki/Flavorist
|
A flavorist, also known as flavor chemist, is someone who uses chemistry to engineer artificial and natural flavors. The tools and materials used by flavorists are almost the same as that used by perfumers with the exception that flavorists seek to mimic or modify both the olfactory and gustatory properties of various food products rather than creating just abstract smells. Additionally, the materials and chemicals that a flavorist utilizes for flavor creation must be safe for human consumption.
The profession of flavorists came about when affordable refrigeration for the home spurred of food processing technology, which could affect the quality of the flavor of the food. In some cases, these technologies can remove naturally occurring flavors. To remedy the flavor loss, the food processing industry created the flavor industry. The chemists that resolved the demand of the food processing industry became known as flavorists.
Education
Educational requirements for the profession known as flavorist are varied. Flavorists are often graduated either in Chemistry, Biology or Food Science up to PhDs obtained in subjects such as Biochemistry and Chemistry. Because, however, the training of a flavorist is mostly done on-the-job and specifically at a flavor company known as a flavor house, this training is similar to the apprentice system.
Located in Versailles (France), ISIPCA French School offers two years of high-standard education in food flavoring including 12 months traineeship in a flavor company. This education program provides students with solid background in Flavoring formulation, flavor application, and flavor chemistry (analysis and sensory).
The British Society of Flavourists together with Reading University provide, every year, a three-week flavorist training course for flavorists from all around the world.
Flavorist societies
In the United States, a certified flavorist must be a member of the Society of Flavor Chemists, which meets in New Jersey, Cincin
|
https://en.wikipedia.org/wiki/Cell%20cortex
|
The cell cortex, also known as the actin cortex, cortical cytoskeleton or actomyosin cortex, is a specialized layer of cytoplasmic proteins on the inner face of the cell membrane. It functions as a modulator of membrane behavior and cell surface properties. In most eukaryotic cells lacking a cell wall, the cortex is an actin-rich network consisting of F-actin filaments, myosin motors, and actin-binding proteins. The actomyosin cortex is attached to the cell membrane via membrane-anchoring proteins called ERM proteins that plays a central role in cell shape control. The protein constituents of the cortex undergo rapid turnover, making the cortex both mechanically rigid and highly plastic, two properties essential to its function. In most cases, the cortex is in the range of 100 to 1000 nanometers thick.
In some animal cells, the protein spectrin may be present in the cortex. Spectrin helps to create a network by cross-linked actin filaments. The proportions of spectrin and actin vary with cell type. Spectrin proteins and actin microfilaments are attached to transmembrane proteins by attachment proteins between them and the transmembrane proteins. The cell cortex is attached to the inner cytosolic face of the plasma membrane in cells where the spectrin proteins and actin microfilaments form a mesh-like structure that is continuously remodeled by polymerization, depolymerization and branching.
Many proteins are involved in the cortex regulation and dynamics including formins with roles in actin polymerization, Arp2/3 complexes that give rise to actin branching and capping proteins. Due to the branching process and the density of the actin cortex, the cortical cytoskeleton can form a highly complex meshwork such as a fractal structure. Specialized cells are usually characterized by a very specific cortical actin cytoskeleton. For example, in red blood cells, the cell cortex consists of a two-dimensional cross-linked elastic network with pentagonal or hexagonal symme
|
https://en.wikipedia.org/wiki/Corrosion%20fatigue
|
Corrosion fatigue is fatigue in a corrosive environment. It is the mechanical degradation of a material under the joint action of corrosion and cyclic loading. Nearly all engineering structures experience some form of alternating stress, and are exposed to harmful environments during their service life. The environment plays a significant role in the fatigue of high-strength structural materials like steel, aluminum alloys and titanium alloys. Materials with high specific strength are being developed to meet the requirements of advancing technology. However, their usefulness depends to a large extent on the degree to which they resist corrosion fatigue.
The effects of corrosive environments on the fatigue behavior of metals were studied as early as 1930.
The phenomenon should not be confused with stress corrosion cracking, where corrosion (such as pitting) leads to the development of brittle cracks, growth and failure. The only requirement for corrosion fatigue is that the sample be under tensile stress.
Effect of corrosion on S-N diagram
The effect of corrosion on a smooth-specimen S-N diagram is shown schematically on the right. Curve A shows the fatigue behavior of a material tested in air. A fatigue threshold (or limit) is seen in curve A, corresponding to the horizontal part of the curve. Curves B and C represent the fatigue behavior of the same material in two corrosive environments. In curve B, the fatigue failure at high stress levels is retarded, and the fatigue limit is eliminated. In curve C, the whole curve is shifted to the left; this indicates a general lowering in fatigue strength, accelerated initiation at higher stresses and elimination of the fatigue limit.
To meet the needs of advancing technology, higher-strength materials are developed through heat treatment or alloying. Such high-strength materials generally exhibit higher fatigue limits, and can be used at higher service stress levels even under fatigue loading. However, the presence
|
https://en.wikipedia.org/wiki/Constrained%20optimization
|
In mathematical optimization, constrained optimization (in some contexts called constraint optimization) is the process of optimizing an objective function with respect to some variables in the presence of constraints on those variables. The objective function is either a cost function or energy function, which is to be minimized, or a reward function or utility function, which is to be maximized. Constraints can be either hard constraints, which set conditions for the variables that are required to be satisfied, or soft constraints, which have some variable values that are penalized in the objective function if, and based on the extent that, the conditions on the variables are not satisfied.
Relation to constraint-satisfaction problems
The constrained-optimization problem (COP) is a significant generalization of the classic constraint-satisfaction problem (CSP) model. COP is a CSP that includes an objective function to be optimized. Many algorithms are used to handle the optimization part.
General form
A general constrained minimization problem may be written as follows:
where and are constraints that are required to be satisfied (these are called hard constraints), and is the objective function that needs to be optimized subject to the constraints.
In some problems, often called constraint optimization problems, the objective function is actually the sum of cost functions, each of which penalizes the extent (if any) to which a soft constraint (a constraint which is preferred but not required to be satisfied) is violated.
Solution methods
Many constrained optimization algorithms can be adapted to the unconstrained case, often via the use of a penalty method. However, search steps taken by the unconstrained method may be unacceptable for the constrained problem, leading to a lack of convergence. This is referred to as the Maratos effect.
Equality constraints
Substitution method
For very simple problems, say a function of two variables subject to
|
https://en.wikipedia.org/wiki/Polynomial%20expansion
|
In mathematics, an expansion of a product of sums expresses it as a sum of products by using the fact that multiplication distributes over addition. Expansion of a polynomial expression can be obtained by repeatedly replacing subexpressions that multiply two other subexpressions, at least one of which is an addition, by the equivalent sum of products, continuing until the expression becomes a sum of (repeated) products. During the expansion, simplifications such as grouping of like terms or cancellations of terms may also be applied. Instead of multiplications, the expansion steps could also involve replacing powers of a sum of terms by the equivalent expression obtained from the binomial formula; this is a shortened form of what would happen if the power were treated as a repeated multiplication, and expanded repeatedly. It is customary to reintroduce powers in the final result when terms involve products of identical symbols.
Simple examples of polynomial expansions are the well known rules
when used from left to right. A more general single-step expansion will introduce all products of a term of one of the sums being multiplied with a term of the other:
An expansion which involves multiple nested rewrite steps is that of working out a Horner scheme to the (expanded) polynomial it defines, for instance
.
The opposite process of trying to write an expanded polynomial as a product is called polynomial factorization.
Expansion of a polynomial written in factored form
To multiply two factors, each term of the first factor must be multiplied by each term of the other factor. If both factors are binomials, the FOIL rule can be used, which stands for "First Outer Inner Last," referring to the terms that are multiplied together. For example, expanding
yields
Expansion of (x+y)n
When expanding , a special relationship exists between the coefficients of the terms when written in order of descending powers of x and ascending powers of y. The coefficients will b
|
https://en.wikipedia.org/wiki/Tiller%20%28botany%29
|
A tiller is a shoot that arises from the base of a grass plant. The term refers to all shoots that grow after the initial parent shoot grows from a seed. Tillers are segmented, each segment possessing its own two-part leaf. They are involved in vegetative propagation and, in some cases, also seed production.
"Tillering" refers to the production of side shoots and is a property possessed by many species in the grass family. This enables them to produce multiple stems (tillers) starting from the initial single seedling. This ensures the formation of dense tufts and multiple seed heads. Tillering rates are heavily influenced by soil water quantity. When soil moisture is low, grasses tend to develop more sparse and deep root systems (as opposed to dense, lateral systems). Thus, in dry soils, tillering is inhibited: the lateral nature of tillering is not supported by lateral root growth.
See also
Crown (botany)
References
Grasses
Biology terminology
Plant morphology
|
https://en.wikipedia.org/wiki/Piczo
|
Piczo was a social networking and blogging website for teens. It was founded in 2003 by Jim Conning in San Francisco, California. Early investors included Catamount, Sierra Ventures, U.S. Venture Partners, and Mangrove Capital Partners.
In March 2009, Piczo was acquired by Stardoll (Stardoll AB with CEO Mattias Miksche). After the acquisition Piczo was led by Stardoll's CEO Mattias Miksche and his Stardoll team.
In September 2012, Piczo.com was acquired by Posh Media Group (PMGcom Publishing AB with CEO Christofer Båge).
In November 2012, Piczo.com shut down.
Their eponymous service, also called Piczo (Piczo.com), was an online photo website builder and community, which was for the generation of free advertising-supported websites.
Launched in 2005 Piczo allowed users to add images, text, guestbooks, message boxes, videos, music and other content to their site using plain text and HTML. Partners included YouTube, VideoEgg, Photobucket, Flock, Yahoo & PollDaddy. When it began, the company's focus was individual web-page design, and blogs were not included as a feature.
In addition to the website development aspect of the site, Piczo once had a User Generated Content repository (the Piczo Zone) where users can browse, post, and consume content that they or others have used on their site. Later on, Piczo remodelled the entire site, and this along with many other features were no longer available.
One of the features that stayed is "The Board" where Piczo informs users about HTML and Internet safety, though most pages are designed for the old Piczo.
In August 2010 Piczo announced "Piczo Plus", a feature that allows users to buy an "ad-free" site, which is no longer available to purchase.
Popularity
Piczo saw around 10 million unique visitors a month. While primarily offering services in English and German, Piczo was also available
in French, Spanish, Romanian, Russian, Japanese, and Korean BETA versions.
The service was very popular with a teenage audience in B
|
https://en.wikipedia.org/wiki/Shockley%20diode%20equation
|
The Shockley diode equation, or the diode law, named after transistor co-inventor William Shockley of Bell Labs, models the exponential current–voltage (I–V) relationship of semiconductor diodes in moderate constant current forward bias or reverse bias:
where
is the diode current,
is the reverse-bias saturation current (or scale current),
is the voltage across the diode,
is the thermal voltage, and
is the ideality factor, also known as the quality factor or emission coefficient.
The equation is called the Shockley ideal diode equation when the ideality factor equals 1, thus is sometimes omitted. The ideality factor typically varies from 1 to 2 (though can in some cases be higher), depending on the fabrication process and semiconductor material. The ideality factor was added to account for imperfect junctions observed in real transistors, mainly due to carrier recombination as charge carriers cross the depletion region.
The thermal voltage is approximately 25.852mV at . At an arbitrary temperature, it is a known constant:
where
is the Boltzmann constant,
is the absolute temperature of the p–n junction, and
is the elementary charge (the magnitude of an electron's charge).
The reverse saturation current is not constant for a given device, but varies with temperature; usually more significantly than , so that typically decreases as increases.
Under reverse bias, the diode equation's exponential term is near 0, so the current is near the somewhat constant reverse current value (roughly a picoampere for silicon diodes or a microampere for germanium diodes, although this is obviously a function of size).
For moderate forward bias voltages the exponential becomes much larger than 1, since the thermal voltage is very small in comparison. The in the diode equation is then negligible, so the forward diode current will approximate
The use of the diode equation in circuit problems is illustrated in the article on diode modeling.
Limitat
|
https://en.wikipedia.org/wiki/Thermal%20management%20%28electronics%29
|
All electronic devices and circuitry generate excess heat and thus require thermal management to improve reliability and prevent premature failure. The amount of heat output is equal to the power input, if there are no other energy interactions. There are several techniques for cooling including various styles of heat sinks, thermoelectric coolers, forced air systems and fans, heat pipes, and others. In cases of extreme low environmental temperatures, it may actually be necessary to heat the electronic components to achieve satisfactory operation.
Overview
Thermal resistance of devices
This is usually quoted as the thermal resistance from junction to case of the semiconductor device. The units are °C/W. For example, a heatsink rated at 10 °C/W will get 10 °C hotter than the surrounding air when it dissipates 1 Watt of heat. Thus, a heatsink with a low °C/W value is more efficient than a heatsink with a high °C/W value.
Given two semiconductor devices in the same package, a lower junction to ambient resistance (RθJ-C) indicates a more efficient device. However, when comparing two devices with different die-free package thermal resistances (Ex. DirectFET MT vs wirebond 5x6mm PQFN), their junction to ambient or junction to case resistance values may not correlate directly to their comparative efficiencies. Different semiconductor packages may have different die orientations, different copper(or other metal) mass surrounding the die, different die attach mechanics, and different molding thickness, all of which could yield significantly different junction to case or junction to ambient resistance values, and could thus obscure overall efficiency numbers.
Thermal time constants
A heatsink's thermal mass can be considered as a capacitor (storing heat instead of charge) and the thermal resistance as an electrical resistance (giving a measure of how fast stored heat can be dissipated). Together, these two components form a thermal RC circuit with an associated time co
|
https://en.wikipedia.org/wiki/XMK%20%28operating%20system%29
|
The eXtreme Minimal Kernel (XMK) is a real-time operating system (RTOS) that is designed for minimal RAM/ROM use. It achieves this goal, though it is almost entirely written in the C programming language. As a consequence it can be easily ported to any 8-, 16-, or 32-bit microcontroller.
XMK comes as two independent packages: the XMK Scheduler that contains the core kernel, everything necessary to run a multithreaded embedded application, and the Application Programming Layer (APL) that provides higher level functions atop the XMK Scheduler API.
The XMK distribution contains no standard libraries such as libc that should be part of the development tools for target systems.
External links
XMK: eXtreme Minimal Kernel project home page (broken link)
Windows Evolution Over Timeline
Real-time operating systems
Embedded operating systems
|
https://en.wikipedia.org/wiki/Additive%20identity
|
In mathematics, the additive identity of a set that is equipped with the operation of addition is an element which, when added to any element in the set, yields . One of the most familiar additive identities is the number 0 from elementary mathematics, but additive identities occur in other mathematical structures where addition is defined, such as in groups and rings.
Elementary examples
The additive identity familiar from elementary mathematics is zero, denoted 0. For example,
In the natural numbers (if 0 is included), the integers the rational numbers the real numbers and the complex numbers the additive identity is 0. This says that for a number belonging to any of these sets,
Formal definition
Let be a group that is closed under the operation of addition, denoted +. An additive identity for , denoted , is an element in such that for any element in ,
Further examples
In a group, the additive identity is the identity element of the group, is often denoted 0, and is unique (see below for proof).
A ring or field is a group under the operation of addition and thus these also have a unique additive identity 0. This is defined to be different from the multiplicative identity 1 if the ring (or field) has more than one element. If the additive identity and the multiplicative identity are the same, then the ring is trivial (proved below).
In the ring of -by- matrices over a ring , the additive identity is the zero matrix, denoted or , and is the -by- matrix whose entries consist entirely of the identity element 0 in . For example, in the 2×2 matrices over the integers the additive identity is
In the quaternions, 0 is the additive identity.
In the ring of functions from , the function mapping every number to 0 is the additive identity.
In the additive group of vectors in the origin or zero vector is the additive identity.
Properties
The additive identity is unique in a group
Let be a group and let and in both denote additive identities, so f
|
https://en.wikipedia.org/wiki/Hazchem
|
Hazchem (; from hazardous chemicals) is a warning plate system used in Australia, Hong Kong, Malaysia, New Zealand, India and the United Kingdom for vehicles transporting hazardous substances, and on storage facilities. The top-left section of the plate gives the Emergency Action Code (EAC) telling the fire brigade what actions to take if there's an accident or fire. The middle-left section containing a 4 digit number gives the UN Substance Identification Number describing the material. The lower-left section gives the telephone number that should be called if special advice is needed. The warning symbol in the top right indicates the general hazard class of the material. The bottom-right of the plate carries a company logo or name.
There is also a standard null Hazchem plate to indicate the transport of non-hazardous substances. The null plate does not include an EAC or substance identification.
The National Chemical Emergency Centre (NCEC) in the United Kingdom provides a Free Online Hazchem Guide.
Emergency Action Code
The Emergency Action Code (EAC) is a three character code displayed on all dangerous goods classed carriers, and provides a quick assessment to first responders and emergency responders (i.e. fire fighters and police) of what actions to take should the carrier carrying such goods become involved in an incident (traffic collision, for example). EAC's are characterised by a single number (1 to 4) and either one or two letters (depending on the hazard).
NCEC was commissioned by the Department for Communities and Local Government (CLG) to edit the EAC List 2013 publication, outlining the application of Hazchem Emergency Actions Codes (EACs) in Britain for 2013. The Dangerous Goods Emergency Action Code (EAC) List is reviewed every two years and is an essential compliance document for all emergency services, local government and for those who may control the planning for, and prevention of, emergencies involving dangerous goods. The current EAC Lis
|
https://en.wikipedia.org/wiki/Brettanomyces%20bruxellensis
|
Brettanomyces bruxellensis (the anamorph of Dekkera bruxellensis) is a yeast associated with the Senne valley near Brussels, Belgium. Despite its Latin species name, B. bruxellensis is found all over the globe. In the wild, it is often found on the skins of fruit.
Beer production
B. bruxellensis plays a key role in the production of the typical Belgian beer styles such as lambic, Flanders red ales, gueuze and kriek, and is part of spontaneous fermentation biota. The Trappist Orval has very little in it aswell. It is naturally found in the brewery environment living within oak barrels that are used for the storage of beer during the secondary conditioning stage. Here it completes the long slow fermentation or super-attenuation of beer, often in symbiosis with Pediococcus sp. Macroscopically visible colonies look whitish and show a dome-shaped aspect, depending on the age and size.
B. bruxellensis is increasingly being used by American craft brewers, especially in Maine, California and Colorado. Jolly Pumpkin Artisan Ales, Allagash Brewing Company, Port Brewing Company, Sierra Nevada Brewing Company, Russian River Brewing Company and New Belgium Brewing Company have all brewed beers fermented with B. bruxellensis. The beers have a slightly sour, earthy character. Some have described them as having a "barnyard" or "wet horse blanket" flavor.
Wine production
In the wine industry, B. bruxellensis is generally considered a spoilage yeast and it and other members of the genus are often referred to as Brettanomyces ("brett"). Its metabolic products can impart "sweaty saddle leather", "barnyard", "burnt plastic" or "band-aid" aromas to wine. Some winemakers in France, and occasionally elsewhere, consider it a desirable addition to wine, e.g., in Château de Beaucastel, but New World vintners generally consider it a defect. Some authorities consider brett to be responsible for 90% of the spoilage problems in premium red wines.
One defense against brett is to limit pot
|
https://en.wikipedia.org/wiki/Crypt%20%28Unix%29
|
In Unix computing, crypt or enigma is a utility program used for encryption. Due to the ease of breaking it, it is considered to be obsolete.
The program is usually used as a filter, and it has traditionally been implemented using a "rotor machine" algorithm based on the Enigma machine. It is considered to be cryptographically far too weak to provide any security against brute-force attacks by modern, commodity personal computers.
Some versions of Unix shipped with an even weaker version of the crypt(1) command in order to comply with contemporaneous laws and regulations that limited the exportation of cryptographic software. Some of these were simply implementations of the Caesar cipher (effectively no more secure than ROT13, which is implemented as a Caesar cipher with a well-known key).
History
Cryptographer Robert Morris wrote a M-209-based , which first appeared in Version 3 Unix, to encourage codebreaking experiments; Morris managed to break by hand. Dennis Ritchie automated decryption with a method by James Reeds, and a new Enigma-based version appeared in Version 7, which Reeds and Peter J. Weinberger also broke.
crypt(1) under Linux
Linux distributions generally do not include a Unix compatible version of the crypt command. This is largely due to a combination of three major factors:
crypt is relatively obscure and rarely used for e-mail attachments nor as a file format
crypt is considered to be cryptographically far too weak to withstand brute-force attacks by modern computing systems (Linux systems generally ship with GNU Privacy Guard which is considered to be reasonably secure by modern standards)
During the early years of Linux development and adoption there was some concern that even as weak as the algorithm used by crypt was, that it might still run afoul of ITAR's export controls; so mainstream distribution developers in the United States generally excluded it, leaving their customers to fetch GnuPG or other strong cryptographic software fr
|
https://en.wikipedia.org/wiki/PC%20Exchange
|
PC Exchange was a utility program for Apple Macintosh computers. It was a control panel for the classic Mac OS that lets the operating system mount FAT file systems and mapped file extensions to the user-defined type and creator codes.
It was first made available in 1992 as a commercial software product from Apple, but in 1993, it was no longer a commercial product on its own, and shipped with System 7 Pro as part of Apple's push to become more compatible with Microsoft Windows. It worked transparently, mounting the disks on the desktop as if they were normal Mac disks, with the exception of the large letters PC on the icon which were visually similar to the IBM logotype. Originally only floppy disks were supported, but later versions added support for hard drives, CD-ROMs and other types of media.
PC Exchange is not used in macOS, which uses a completely different driver architecture to read the FAT file system.
Compatibility layers
Classic Mac OS
Apple Inc. file systems
|
https://en.wikipedia.org/wiki/Wallace%20tree
|
A Wallace multiplier is a hardware implementation of a binary multiplier, a digital circuit that multiplies two integers. It uses a selection of full and half adders (the Wallace tree or Wallace reduction) to sum partial products in stages until two numbers are left. Wallace multipliers reduce as much as possible on each layer, whereas Dadda multipliers try to minimize the required number of gates by postponing the reduction to the upper layers.
Wallace multipliers were devised by the Australian computer scientist Chris Wallace in 1964.
The Wallace tree has three steps:
Multiply each bit of one of the arguments, by each bit of the other.
Reduce the number of partial products to two by layers of full and half adders.
Group the wires in two numbers, and add them with a conventional adder.
Compared to naively adding partial products with regular adders, the benefit of the Wallace tree is its faster speed. It has reduction layers, but each layer has only propagation delay. A naive addition of partial products would require time.
As making the partial products is and the final addition is , the total multiplication is , not much slower than addition. From a complexity theoretic perspective, the Wallace tree algorithm puts multiplication in the class NC1.
The downside of the Wallace tree, compared to naive addition of partial products, is its much higher gate count.
These computations only consider gate delays and don't deal with wire delays, which can also be very substantial.
The Wallace tree can be also represented by a tree of 3/2 or 4/2 adders.
It is sometimes combined with Booth encoding.
Detailed explanation
The Wallace tree is a variant of long multiplication. The first step is to multiply each digit (each bit) of one factor by each digit of the other. Each of this partial products has weight equal to the product of its factors. The final product is calculated by the weighted sum of all these partial products.
The first step, as said above, is to
|
https://en.wikipedia.org/wiki/Dadda%20multiplier
|
The Dadda multiplier is a hardware binary multiplier design invented by computer scientist Luigi Dadda in 1965. It uses a selection of full and half adders to sum the partial products in stages (the Dadda tree or Dadda reduction) until two numbers are left. The design is similar to the Wallace multiplier, but the different reduction tree reduces the required number of gates (for all but the smallest operand sizes) and makes it slightly faster (for all operand sizes).
Dadda and Wallace multipliers have the same three steps for two bit strings and of lengths and respectively:
Multiply (logical AND) each bit of , by each bit of , yielding results, grouped by weight in columns
Reduce the number of partial products by stages of full and half adders until we are left with at most two bits of each weight.
Add the final result with a conventional adder.
As with the Wallace multiplier, the multiplication products of the first step carry different weights reflecting the magnitude of the original bit values in the multiplication. For example, the product of bits has weight .
Unlike Wallace multipliers that reduce as much as possible on each layer, Dadda multipliers attempt to minimize the number of gates used, as well as input/output delay. Because of this, Dadda multipliers have a less expensive reduction phase, but the final numbers may be a few bits longer, thus requiring slightly bigger adders.
Description
To achieve a more optimal final product, the structure of the reduction process is governed by slightly more complex rules than in Wallace multipliers.
The progression of the reduction is controlled by a maximum-height sequence , defined by:
, and
This yields a sequence like so:
The initial value of is chosen as the largest value such that , where and are the number of bits in the input multiplicand and multiplier. The lesser of the two bit lengths will be the maximum height of each column of weights after the first stage of multiplication.
|
https://en.wikipedia.org/wiki/Comparison%20of%20hex%20editors
|
The following is a comparison of notable hex editors.
General
Features
See also
Comparison of HTML editors
Comparison of integrated development environments
Comparison of text editors
Comparison of word processors
Notes
ao: ANSI is the Windows character set, OEM is the DOS character set. Both are based on ASCII.
References
External links
"Harry's Windows Hex Editor Review" (July 2002). harrymnielsen.tripod.com. Retrieved October 15, 2019.
Hex editors
Text editor comparisons
|
https://en.wikipedia.org/wiki/Railway%20Preservation%20Society%20of%20Ireland
|
The Railway Preservation Society of Ireland (RPSI) is a railway preservation group founded in 1964 and operating throughout Ireland. Mainline steam train railtours are operated from Dublin, while short train rides are operated up and down the platform at Whitehead, County Antrim, and as of 2023, the group sometimes operates mainline trains in Northern Ireland using hired-in NIR diesel trains from Belfast. The RPSI has bases in Dublin and Whitehead, with the latter having a museum. The society owns heritage wagons, carriages, steam engines, diesel locomotives and metal-bodied carriages suitable for mainline use.
Bases
The society has developed several bases over time, with Whitehead joined by Sallins, then Mullingar, and also Inchicore and Connolly in Dublin. As of 2019, three locations are in operation: Whitehead, Inchicore and Connolly.
Current operations
Whitehead site and museum
Whitehead, near Belfast, has a long history as an excursion station, and the RPSI developed a working steam and engineering depot there. This was added to by the development of a museum.
The Whitehead Railway Museum opened without ceremony in early 2017, after a 5-year project to expand the site from a depot to include a rebuilt Whitehouse Excursion station and the museum. The total cost was £3.1m from various funding sources. The museum received 10,000 visitors in 2017, its first year, and 15,000 in 2018. The museum hosts five galleries and it is possible for visitors to see various heritage steam and diesel locomotives and observe work on railway carriage restoration. Guides from the society are present.
Inchicore, Dublin
The RPSI has arrangements for storage of stock at Inchicore Works with maintenance also being carried out there.
Connolly shed
In 2015 the RPSI gained an arrangement with Iarnród Éireann to lease the locomotive shed just to the north of for the maintenance and storage of mainline diesel locomotives.
Historic operations
Mullingar
The RPSI moved into the loco
|
https://en.wikipedia.org/wiki/Tablet%20computer
|
A tablet computer, commonly shortened to tablet, is a mobile device, typically with a mobile operating system and touchscreen display processing circuitry, and a rechargeable battery in a single, thin and flat package. Tablets, being computers, have similar capabilities, but lack some input/output (I/O) abilities that others have. Modern tablets largely resemble modern smartphones, the only differences being that tablets are relatively larger than smartphones, with screens or larger, measured diagonally, and may not support access to a cellular network. Unlike laptops (which have traditionally run off operating systems usually designed for desktops), tablets usually run mobile operating systems, alongside smartphones.
The touchscreen display is operated by gestures executed by finger or digital pen (stylus), instead of the mouse, touchpad, and keyboard of larger computers. Portable computers can be classified according to the presence and appearance of physical keyboards. Two species of tablet, the slate and booklet, do not have physical keyboards and usually accept text and other input by use of a virtual keyboard shown on their touchscreen displays. To compensate for their lack of a physical keyboard, most tablets can connect to independent physical keyboards by Bluetooth or USB; 2-in-1 PCs have keyboards, distinct from tablets.
The form of the tablet was conceptualized in the middle of the 20th century (Stanley Kubrick depicted fictional tablets in the 1968 science fiction film 2001: A Space Odyssey) and prototyped and developed in the last two decades of that century. In 2010, Apple released the iPad, the first mass-market tablet to achieve widespread popularity. Thereafter, tablets rapidly rose in ubiquity and soon became a large product category used for personal, educational and workplace applications. Popular uses for a tablet PC include viewing presentations, video-conferencing, reading e-books, watching movies, sharing photos and more. As of 2021 there
|
https://en.wikipedia.org/wiki/Septum%20transversum
|
The septum transversum is a thick mass of cranial mesenchyme, formed in the embryo, that gives rise to parts of the thoracic diaphragm and the ventral mesentery of the foregut in the developed human being and other mammals.
Origins
The septum transversum originally arises as the most cranial part of the mesenchyme on day 22. During craniocaudal folding, it assumes a position cranial to the developing heart at the level of the cervical vertebrae. During subsequent weeks the dorsal end of the embryo grows much faster than its ventral counterpart resulting in an apparent descent of the ventrally located septum transversum. At week 8, it can be found at the level of the thoracic vertebrae.
Nerve supply
After successful craniocaudal folding the septum transversum picks up innervation from the adjacent ventral rami of spinal nerves C3, C4 and C5, thus forming the precursor of the phrenic nerve. During the descent of the septum, the phrenic nerve is carried along and assumes its descending pathway.
During embryonic development of the thoracic diaphragm, myoblast cells from the septum invade the other components of the diaphragm. They thus give rise to the motor and sensory innervation of the muscular diaphragm by the phrenic nerve.
Derivatives
The cranial part of the septum transversum gives rise to the central tendon of the diaphragm, and is the origin of the myoblasts that invade the pleuroperitoneal folds resulting in the formation of the muscular diaphragm.
The caudal part of the septum transversum is invaded by the hepatic diverticulum which divides within it to form the liver and thus gives rise to the ventral mesentery of the foregut, which in turn is the precursor of the lesser omentum, the visceral peritoneum of the liver and the falciform ligament.
Though not derived from the septum transversum, development of the liver is highly dependent upon signals originating here. Bone morphogenetic protein 2 (BMP-2), BMP-4 and BMP-7 produced from the septum transv
|
https://en.wikipedia.org/wiki/High-Speed%20Serial%20Interface
|
The High-Speed Serial Interface (HSSI) is a differential ECL serial interface standard developed by Cisco Systems and T3plus Networking primarily for use in WAN router connections. It is capable of speeds up to 52 Mbit/s with cables up to in length.
While HSSI uses 50-pin connector physically similar to that used by SCSI-2, it requires a cable with an impedance of 110 Ω (as opposed to the 75 Ω of a SCSI-2 cable).
The physical layer of the standard is defined by EIA-613 and the electrical layer by EIA-612.
It is supported by the Linux kernel since version 3.4-rc2.
References
External links
What is HSSI?
HSSI Description
Serial buses
|
https://en.wikipedia.org/wiki/Platform%20Invocation%20Services
|
Platform Invocation Services, commonly referred to as P/Invoke, is a feature of Common Language Infrastructure implementations, like Microsoft's Common Language Runtime, that enables managed code to call native code.
Managed code, such as C# or VB.NET, provides native access to classes, methods, and types defined within the libraries that make up the .NET Framework. While the .NET Framework provides an extensive set of functionality, it may lack access to many lower level operating system libraries normally written in unmanaged code or third party libraries also written in unmanaged code. P/Invoke is the technique a programmer can use to access functions in these libraries. Calls to functions within these libraries occur by declaring the signature of the unmanaged function within managed code, which serves as the actual function that can be called like any other managed method. The declaration references the library's file path and defines the function parameters and return in managed types that are most likely to be implicitly marshaled to and from the unmanaged types by the common language run-time (CLR). When the unmanaged data types become too complex for a simple implicit conversion from and to managed types, the framework allows the user to define attributes on the function, return, and/or the parameters to explicitly refine how the data should be marshaled so as not to lead to exceptions in trying to do so implicitly.
There are many abstractions of lower-level programming concepts available to managed code programmers as compared to programming in unmanaged languages. As a result, a programmer with only managed code experience will need to brush up on programming concepts such as pointers, structures, and passing by reference to overcome some of the obstacles in using P/Invoke.
Architecture
Overview
Two variants of P/Invoke currently in use are:
Explicit
Native code is imported via dynamic-linked libraries (DLLs)
Metadata embedded in the caller's
|
https://en.wikipedia.org/wiki/SIMDIS
|
SIMDIS is a software toolset developed by Code 5770 at the US Naval Research Laboratory (NRL). The software provides 2D and 3D interactive graphical and video displays of live and postprocessed simulation, test, and operational data. SIMDIS is a portmanteau of simulation and display.
Features
SIMDIS runs on Windows, Linux, and Sun Microsystems workstations with hardware-accelerated 3D graphics and provides identical execution and "look and feel" for all supported platforms.
SIMDIS provides either a 2D or a 3D display of the normally "seen" data such as platform position and orientation, as well as the "unseen" data such as the interactions of sensor systems with targets, countermeasures, and the environment. It includes custom tools for interactively analyzing and displaying data for equipment modes, spatial grids, ranges, angles, antenna patterns, line of sight and RF propagation. Capability for viewing time synchronized data from either a standalone workstation or multiple networked workstations is also provided.
To meet the needs of range operators, simulation users, analysts, and decision makers SIMDIS provides multiple modes of operation including live display, interactive playback, and scripted multimedia modes. It also provides capability for manipulation of post-processed data and integration with charts, graphs, pictures, audio and video for use in the development and delivery of 3-D visual presentations.
SIMDIS binaries are released under U.S. Department of Defense (DoD) Distribution Statement A, meaning the binaries are approved for public release with unlimited distribution. SIMDIS has been independently accredited and certified by Commander Operational Test and Evaluation Force (COMOPTEVFOR) and Joint Forces Command (JFCOM). It has also been approved for use on the Navy/Marine Corps Intranet (NMCI).
Operational use
SIMDIS provides support for analysis and display of test and training mission data to more than 4000 users. At the Naval Research La
|
https://en.wikipedia.org/wiki/Compensation%20law%20of%20mortality
|
The compensation law of mortality (or late-life mortality convergence) states that the relative differences in death rates between different populations of the same biological species decrease with age, because the higher initial death rates in disadvantaged populations are compensated by lower pace of mortality increase with age. The age at which this imaginary (extrapolated) convergence of mortality trajectories takes place is named the "species-specific life span" (see Gavrilov and Gavrilova, 1979). For human beings, this human species-specific life span is close to 95 years (Gavrilov and Gavrilova, 1979; 1991).
Compensation law of mortality is a paradoxical empirical observation, and it represents a challenge for methods of survival analysis based on proportionality assumption (proportional hazard models). The compensation law of mortality also represents a great challenge for many theories of aging and mortality, which usually fail to explain this phenomenon. On the other hand, the compensation law follows directly from reliability theory, when the compared systems have different initial levels of redundancy.
See also
Ageing
Biodemography of human longevity
Biogerontology
Demography
Mortality
Reliability theory of aging and longevity
References
Gavrilov LA, Gavrilova NS. "Reliability Theory of Aging and Longevity." In: Masoro E.J. & Austad S.N.. (eds.): Handbook of the Biology of Aging, Sixth Edition. Academic Press. San Diego, CA, USA, 2006, 3-42.
Gavrilov LA, Gavrilova NS. Why We Fall Apart. Engineering's Reliability Theory Explains Human Aging. IEEE Spectrum, 2004, 41(9): 30–35.
Gavrilov L.A., Gavrilova N.S. "The quest for a general theory of aging and longevity". Science's SAGE KE (Science of Aging Knowledge Environment) for 16 July 2003; Vol. 2003, No. 28, 1–10. https://www.science.org/loi/sageke,
Gavrilov L.A., Gavrilova N.S. The reliability theory of aging and longevity. Journal of Theoretical Biology, 2001, 213(4): 527–545.
|
https://en.wikipedia.org/wiki/Chetaev%20instability%20theorem
|
The Chetaev instability theorem for dynamical systems states that if there exists, for the system with an equilibrium point at the origin, a continuously differentiable function V(x) such that
the origin is a boundary point of the set ;
there exists a neighborhood of the origin such that for all
then the origin is an unstable equilibrium point of the system.
This theorem is somewhat less restrictive than the Lyapunov instability theorems, since a complete sphere (circle) around the origin for which and both are of the same sign does not have to be produced.
It is named after Nicolai Gurevich Chetaev.
Applications
Chetaev instability theorem has been used to analyze the unfolding dynamics of proteins under the effect of optical tweezers.
See also
Lyapunov function — a function whose existence guarantees stability
References
Further reading
Theorems in dynamical systems
Stability theory
|
https://en.wikipedia.org/wiki/GoForce
|
The Nvidia GoForce was a line of chipsets that was used mainly in handheld devices such as PDAs and mobile phones. Nvidia acquired graphics display processor firm MediaQ in 2003, and rebranded the division as GoForce. It has since been replaced by the Nvidia Tegra series of SoCs.
Features
GoForce 2100
Featuring VGA image capture, 2D graphics acceleration, JPEG support, and MJPEG acceleration. Used in the Samsung SCH-M500 Palm OS based flip-phone.
GoForce 2150
Featuring 1.3-megapixel camera support, JPEG support, and 2D graphics acceleration.
Supports 3-megapixel images with the upgrade.
GoForce 3000/GoForce 4000
The GoForce 4000 supports 3.0-megapixel camera and MPEG-4/H.263 codec, whilst GoForce 3000 is a low-cost version of the GoForce 4000 with limited features.
GoForce 4500
Features 3D graphics support with a geometry processor and programmable pixel shaders, used in the Gizmondo device.
GoForce 4800
Supports 3.0-megapixel camera and a 3D graphics engine.
GoForce 5500
The GoForce 5500 is a multimedia processor, incorporates Tensilica Xtensa HiFi 2 Audio Engine (based on the Xtensa LX processor licensed in 2005). It can decode video and audio formats, such as WMV, WMA, MP3, MP4, MPEG, JPEG and supports H.264. Also including a 24-bit 64-voice sound processor with supports up to 32 MB of external memory, 10-megapixel camera support, and 3D graphics engine version 2.
GoForce 5300
Equipped with 2.25 MiB embedded DRAM (eDRAM) on TSMC's 65 nm process, being the first in the GoForce product line. Its multimedia technology is claimed to be similar to the 5500's, but it does not sport a 3D engine and only supports much smaller screens.
GoForce 6100
The latest chipset in the series, the GoForce 6100 (showcased in 2007), claiming the first applications processor by NVIDIA, adds 10-megapixel camera support and integrated 802.11b/g support (with external RF), based on a 130 nm process. It contains a 250 MHz ARM1176JZ-S core.
Implementations
Acer N300 PDA
HTC Fores
|
https://en.wikipedia.org/wiki/Mixed-species%20foraging%20flock
|
A mixed-species feeding flock, also termed a mixed-species foraging flock, mixed hunting party or informally bird wave, is a flock of usually insectivorous birds of different species that join each other and move together while foraging. These are different from feeding aggregations, which are congregations of several species of bird at areas of high food availability.
While it is currently unknown how mixed-species foraging flocks originate, researchers have proposed a few mechanisms for their initiation. Many believe that nuclear species play a vital role in mixed-species flock initiation. Additionally, the forest structure is hypothesized to play a vital role in these flocks' formation. In Sri Lanka, for example, vocal mimicry by the greater racket-tailed drongo might have a key role in the initiation of mixed-species foraging flocks, while in parts of the American tropics packs of foraging golden-crowned warblers might play the same role.
Composition
Mixed-species foraging flocks tend to form around a "nuclear" species. Researchers believe nuclear species both stimulate the formation of a mixed-species flock and maintain the cohesion between bird species. They tend to have a disproportionately large influence on the flock. Nuclear species have a few universal qualities. Typically, they are both generalists that employ a gleaning foraging strategy and intraspecifically social birds. "Associate" or "attendant" species are birds that trail the flock only after it has entered their territory. Researchers have shown that these species tend to have a higher fitness following mixed-species foraging flocks. The third class of birds found in mixed-species flocks have been termed "sentinel" species. Unlike nuclear species, sentinels are fly-catching birds that are rarely gregarious. Their role is to alert the other birds in the mixed-species flock to the arrival of potential predators.
Benefits
Ecologists generally assume that species in the same ecological niche comp
|
https://en.wikipedia.org/wiki/Parrondo%27s%20paradox
|
Parrondo's paradox, a paradox in game theory, has been described as: A combination of losing strategies becomes a winning strategy. It is named after its creator, Juan Parrondo, who discovered the paradox in 1996. A more explanatory description is:
There exist pairs of games, each with a higher probability of losing than winning, for which it is possible to construct a winning strategy by playing the games alternately.
Parrondo devised the paradox in connection with his analysis of the Brownian ratchet, a thought experiment about a machine that can purportedly extract energy from random heat motions popularized by physicist Richard Feynman. However, the paradox disappears when rigorously analyzed. Winning strategies consisting of various combinations of losing strategies were explored in biology before Parrondo's paradox was published.
Illustrative examples
According to Harmer and Abbott, other than the last two examples (i.e. the saw-tooth example and the coin-tossing example), the other examples do not truly exhibit Parrondo's paradox in its strictest definition. In particular, since Parrondo's paradox was physically motivated from the flashing Brownian ratchet, a skip free process must be used to properly preserve this ratchet action and so only a +1 or -1 unit payoff structure can be used. See the coin-tossing example for an explicit illustration of this.
The simple example
Consider two games Game A and Game B, with the following rules:
In Game A, you lose $1 every time you play.
In Game B, you count how much money you have left — if it is an even number you win $3, otherwise you lose $5.
Say you begin with $100 in your pocket. If you start playing Game A exclusively, you will obviously lose all your money in 100 rounds. Similarly, if you decide to play Game B exclusively, you will also lose all your money in 100 rounds.
However, consider playing the games alternatively, starting with Game B, followed by A, then by B, and so on (BABABA...). It shou
|
https://en.wikipedia.org/wiki/Gompertz%E2%80%93Makeham%20law%20of%20mortality
|
The Gompertz–Makeham law states that the human death rate is the sum of an age-dependent component (the Gompertz function, named after Benjamin Gompertz), which increases exponentially with age and an age-independent component (the Makeham term, named after William Makeham). In a protected environment where external causes of death are rare (laboratory conditions, low mortality countries, etc.), the age-independent mortality component is often negligible. In this case the formula simplifies to a Gompertz law of mortality. In 1825, Benjamin Gompertz proposed an exponential increase in death rates with age.
The Gompertz–Makeham law of mortality describes the age dynamics of human mortality rather accurately in the age window from about 30 to 80 years of age. At more advanced ages, some studies have found that death rates increase more slowly – a phenomenon known as the late-life mortality deceleration – but more recent studies disagree.
The decline in the human mortality rate before the 1950s was mostly due to a decrease in the age-independent (Makeham) mortality component, while the age-dependent (Gompertz) mortality component was surprisingly stable. Since the 1950s, a new mortality trend has started in the form of an unexpected decline in mortality rates at advanced ages and "rectangularization" of the survival curve.
The hazard function for the Gompertz-Makeham distribution is most often characterised as . The empirical magnitude of the beta-parameter is about .085, implying a doubling of mortality every .69/.085 = 8 years (Denmark, 2006).
The quantile function can be expressed in a closed-form expression using the Lambert W function:
The Gompertz law is the same as a Fisher–Tippett distribution for the negative of age, restricted to negative values for the random variable (positive values for age).
Future of human longevity
The birth year cohorts of those born after 1950 should be the first to see a considerable delay in the historical course of death,
|
https://en.wikipedia.org/wiki/Readers%E2%80%93writer%20lock
|
In computer science, a readers–writer (single-writer lock, a multi-reader lock, a push lock, or an MRSW lock) is a synchronization primitive that solves one of the readers–writers problems. An RW lock allows concurrent access for read-only operations, whereas write operations require exclusive access. This means that multiple threads can read the data in parallel but an exclusive lock is needed for writing or modifying data. When a writer is writing the data, all other writers and readers will be blocked until the writer is finished writing. A common use might be to control access to a data structure in memory that cannot be updated atomically and is invalid (and should not be read by another thread) until the update is complete.
Readers–writer locks are usually constructed on top of mutexes and condition variables, or on top of semaphores.
Upgradable RW lock
Some RW locks allow the lock to be atomically upgraded from being locked in read-mode to write-mode, as well as being downgraded from write-mode to read-mode. Upgrading a lock from read-mode to write-mode is prone to deadlocks, since whenever two threads holding reader locks both attempt to upgrade to writer locks, a deadlock is created that can only be broken by one of the threads releasing its reader lock. The deadlock can be avoided by allowing only one thread to acquire the lock in "read-mode with intent to upgrade to write" while there are no threads in write mode and possibly non-zero threads in read-mode.
Priority policies
RW locks can be designed with different priority policies for reader vs. writer access. The lock can either be designed to always give priority to readers (read-preferring), to always give priority to writers (write-preferring) or be unspecified with regards to priority. These policies lead to different tradeoffs with regards to concurrency and starvation.
Read-preferring RW locks allow for maximum concurrency, but can lead to write-starvation if contention is high. This is becau
|
https://en.wikipedia.org/wiki/Ethyl%20benzoate
|
Ethyl benzoate, C9H10O2, is an ester formed by the condensation of benzoic acid and ethanol. It is a colorless liquid that is almost insoluble in water, but miscible with most organic solvents.
As with many volatile esters, ethyl benzoate has a pleasant odor described as sweet, wintergreen, fruity, medicinal, cherry and grape. It is a component of some fragrances and artificial fruit flavors.
Preparation
A simple and commonly used method for the preparation of ethyl benzoate in laboratory is the acidic esterification of benzoic acid with ethanol and sulfuric acid as catalyst:
References
External links
Material Safety Data Sheet
Ethyl esters
Benzoate esters
Perfume ingredients
Flavors
Sweet-smelling chemicals
|
https://en.wikipedia.org/wiki/Salt%20tide
|
Salt tide is a phenomenon in which the lower course of a river, with its low altitude with respect to the sea level, becomes salty when the discharge of the river is low during dry season, usually worsened by the result of astronomical high tide.
The lower course Xijiang (West River) in Guangdong, China was periodically affected and has been widely reported since 2004, for bringing shortage of fresh water supply to the western part of the Pearl River Delta. The salinity level of tap water at Zhuhai was reported to be as high as 800 mg per litre in late February 2006, more than 3 times higher than the World Health Organization standard of 250 mg.
References
"Fresh-water crisis looms for Macau - Salinity keeps rising despite assurances", South China Morning Post, Page A7 Hong Kong & Delta, published Thursday, February 23, 2006.
Hydrology
Rivers
Freshwater ecology
|
https://en.wikipedia.org/wiki/Gravity%20%28alcoholic%20beverage%29
|
Gravity, in the context of fermenting alcoholic beverages, refers to the specific gravity (abbreviated SG), or relative density compared to water, of the wort or must at various stages in the fermentation. The concept is used in the brewing and wine-making industries. Specific gravity is measured by a hydrometer, refractometer, pycnometer or oscillating U-tube electronic meter.
The density of a wort is largely dependent on the sugar content of the wort. During alcohol fermentation, yeast converts sugars into carbon dioxide and alcohol. By monitoring the decline in SG over time the brewer obtains information about the health and progress of the fermentation and determines that it is complete when gravity stops declining. If the fermentation is finished, the specific gravity is called the final gravity (abbreviated FG). For example, for a typical strength beer, original gravity (abbreviated OG) could be 1.050 and FG could be 1.010.
Several different scales have been used for measuring the original gravity. For historical reasons, the brewing industry largely uses the Plato scale (°P), which is essentially the same as the Brix scale used by the wine industry. For example, OG 1.050 is roughly equivalent to 12°P.
By considering the original gravity, the brewer or vintner obtains an indication as to the probable ultimate alcoholic content of their product. The OE (Original Extract) is often referred to as the "size" of the beer and is, in Europe, often printed on the label as or sometimes just as a per cent. In the Czech Republic, for example, common descriptions are "10 degree beers", "12 degree beers" which refers to the gravity in Plato of the wort before the fermentation.
Low vs. high gravity beers
The difference between the original gravity of the wort and the final gravity of the beer is an indication of how much sugar has been turned into alcohol. The bigger the difference, the greater the amount of alcohol present and hence the stronger the beer. This is wh
|
https://en.wikipedia.org/wiki/Higman%27s%20lemma
|
In mathematics, Higman's lemma states that the set of finite sequences over a finite alphabet, as partially ordered by the subsequence relation, is well-quasi-ordered. That is, if is an infinite sequence of words over some fixed finite alphabet, then there exist indices such that can be obtained from by deleting some (possibly none) symbols. More generally this remains true when the alphabet is not necessarily finite, but is itself well-quasi-ordered, and the subsequence relation allows the replacement of symbols by earlier symbols in the well-quasi-ordering of labels. This is a special case of the later Kruskal's tree theorem. It is named after Graham Higman, who published it in 1952.
Reverse-mathematical calibration
Higman's lemma has been reverse mathematically calibrated (in terms of subsystems of second-order arithmetic) as equivalent to over the base theory .
References
Wellfoundedness
Order theory
Lemmas
|
https://en.wikipedia.org/wiki/Lozani%C4%87%27s%20triangle
|
Lozanić's triangle (sometimes called Losanitsch's triangle) is a triangular array of binomial coefficients in a manner very similar to that of Pascal's triangle. It is named after the Serbian chemist Sima Lozanić, who researched it in his investigation into the symmetries exhibited by rows of paraffins (archaic term for alkanes).
The first few lines of Lozanić's triangle are
1
1 1
1 1 1
1 2 2 1
1 2 4 2 1
1 3 6 6 3 1
1 3 9 10 9 3 1
1 4 12 19 19 12 4 1
1 4 16 28 38 28 16 4 1
1 5 20 44 66 66 44 20 5 1
1 5 25 60 110 126 110 60 25 5 1
1 6 30 85 170 236 236 170 85 30 6 1
1 6 36 110 255 396 472 396 255 110 36 6 1
1 7 42 146 365 651 868 868 651 365 146 42 7 1
1 7 49 182 511 1001 1519 1716 1519 1001 511 182 49 7 1
1 8 56 231 693 1512 2520 3235 3235 2520 1512 693 231 56 8 1
listed in .
Like Pascal's triangle, outer edge diagonals of Lozanić's triangle are all 1s, and most of the enclosed numbers are the sum of the two numbers above. But for numbers at odd positions k in even-numbered rows n (starting the numbering for both with 0), after adding the two numbers above, subtract the number at position (k − 1)/2 in row n/2 − 1 of Pascal's triangle.
The diagonals next to the edge diagonals contain the positive integers in order, but with each integer stated twi
|
https://en.wikipedia.org/wiki/Interlocus%20contest%20evolution
|
Interlocus contest evolution (ICE) is a process of intergenomic conflict by which different loci within a single genome antagonistically coevolve. ICE supposes that the Red Queen process, which is characterized by a never-ending antagonistic evolutionary arms race, does not only apply to species but also to genes within the genome of a species.
Because sexual recombination allows different gene loci to evolve semi-autonomously, genes have the potential to coevolve antagonistically. ICE occurs when "an allelic substitution at one locus selects for a new allele at the interacting locus, and vice versa." As a result, ICE can lead to a chain reaction of perpetual gene substitution at antagonistically interacting loci, and no stable equilibrium can be achieved. The rate of evolution thus increases at that locus.
ICE is thought to be the dominant mode of evolution for genes controlling social behavior. The ICE process can explain many biological phenomena, including intersexual conflict, parent offspring conflict, and interference competition.
Intersexual conflict
A fundamental conflict between the sexes lies in differences in investment: males generally invest predominantly in fertilization while females invest predominantly in offspring. This conflict manifests itself in many traits associated with sexual reproduction. Genes expressed in only one sex are selectively neutral in the other sex; male- and female-linked genes can therefore be acted upon separated by selection and will evolve semi-autonomously. Thus, one sex of a species may evolve to better itself rather than better the species as a whole, sometimes with negative results for the opposite sex: loci will antagonistically coevolve to enhance male reproductive success at females’ expense on the one hand, and to enhance female resistance to male coercion on the other. This is an example of intralocus sexual conflict, and is unlikely to be resolved fully throughout the genome. However, in some cases this confl
|
https://en.wikipedia.org/wiki/224%20%28number%29
|
224 (two hundred [and] twenty-four) is the natural number following 223 and preceding 225.
In mathematics
224 is a practical number,
and a sum of two positive cubes . It is also , making it one of the smallest numbers to be the sum of distinct positive cubes in more than one way.
224 is the smallest k with λ(k) = 24, where λ(k) is the Carmichael function.
The mathematician and philosopher Alex Bellos suggested in 2014 that a candidate for the lowest uninteresting number would be 224 because it was, at the time, "the lowest number not to have its own page on [the English-language version of] Wikipedia".
In other areas
In the SHA-2 family of six cryptographic hash functions, the weakest is SHA-224, named because it produces 224-bit hash values. It was defined in this way so that the number of bits of security it provides (half of its output length, 112 bits) would match the key length of two-key Triple DES.
The ancient Phoenician shekel was a standardized measure of silver, equal to 224 grains, although other forms of the shekel employed in other ancient cultures (including the Babylonians and Hebrews) had different measures. Likely not coincidentally, as far as ancient Burma and Thailand, silver was measured in a unit called a tikal, equal to 224 grains.
See also
224 (disambiguation)
References
Integers
|
https://en.wikipedia.org/wiki/River%20ecosystem
|
River ecosystems are flowing waters that drain the landscape, and include the biotic (living) interactions amongst plants, animals and micro-organisms, as well as abiotic (nonliving) physical and chemical interactions of its many parts. River ecosystems are part of larger watershed networks or catchments, where smaller headwater streams drain into mid-size streams, which progressively drain into larger river networks. The major zones in river ecosystems are determined by the river bed's gradient or by the velocity of the current. Faster moving turbulent water typically contains greater concentrations of dissolved oxygen, which supports greater biodiversity than the slow-moving water of pools. These distinctions form the basis for the division of rivers into upland and lowland rivers.
The food base of streams within riparian forests is mostly derived from the trees, but wider streams and those that lack a canopy derive the majority of their food base from algae. Anadromous fish are also an important source of nutrients. Environmental threats to rivers include loss of water, dams, chemical pollution and introduced species. A dam produces negative effects that continue down the watershed. The most important negative effects are the reduction of spring flooding, which damages wetlands, and the retention of sediment, which leads to the loss of deltaic wetlands.
River ecosystems are prime examples of lotic ecosystems. Lotic refers to flowing water, from the Latin , meaning washed. Lotic waters range from springs only a few centimeters wide to major rivers kilometers in width. Much of this article applies to lotic ecosystems in general, including related lotic systems such as streams and springs. Lotic ecosystems can be contrasted with lentic ecosystems, which involve relatively still terrestrial waters such as lakes, ponds, and wetlands. Together, these two ecosystems form the more general study area of freshwater or aquatic ecology.
The following unifying characterist
|
https://en.wikipedia.org/wiki/IBM%2037xx
|
IBM 37xx (or 37x5) is a family of IBM Systems Network Architecture (SNA) programmable communications controllers used mainly in mainframe environments.
All members of the family ran one of three IBM-supplied programs.
Emulation Program (EP) mimicked the operation of the older IBM 270x non-programmable controllers.
Network Control Program (NCP) supported Systems Network Architecture devices.
Partitioned Emulation Program (PEP) combined the functions of the two.
Models
370x series
3705 — the oldest of the family, introduced in 1972 to replace the non-programmable IBM 270x family. The 3705 could control up to 352 communications lines.
3704 was a smaller version, introduced in 1973. It supported up to 32 lines.
371x
The 3710 communications controller was introduced in 1984.
372x series
The 3725 and the 3720 systems were announced in 1983. The 3725 replaced the hardware line scanners used on previous 370x machines with multiple microcoded processors.
The 3725 was a large-scale node and front end processor.
The 3720 was a smaller version of the 3725, which was sometimes used as a remote concentrator.
The 3726 was an expansion unit for the 3725.
With the expansion unit, the 3725 could support up to 256 lines at data rates up to 256 kbit/s, and connect to up to eight mainframe channels.
Marketing of the 372x machines was discontinued in 1989.
IBM discontinued support for the 3705, 3720, 3725 in 1999.
374x series
The 3745, announced in 1988, provides up to eight T1 circuits. At the time of the announcement, IBM was estimated to have nearly 85% of the over US$825 million market for communications controllers over rivals such as NCR Comten and Amdahl Corporation. The 3745 is no longer marketed, but still supported and used.
The 3746 "Nways Controller" model 900, unveiled in 1992, was an expansion unit for the 3745 supporting additional Token Ring and ESCON connections. A stand-alone model 950 appeared in 1995.
Successors
IBM no longer manufactures 37xx p
|
https://en.wikipedia.org/wiki/Ethnopsychopharmacology
|
A growing body of research has begun to highlight differences in the way racial and ethnic groups respond to psychiatric medication.
It has been noted that there are "dramatic cross-ethnic and cross-national variations in the dosing practices and side-effect profiles in response to practically all classes of psychotropics."
Differences in drug metabolism
Drug metabolism is controlled by a number of specific enzymes, and the action of these enzymes varies among individuals. For example, most individuals show normal activity of the IID6 isoenzyme that is responsible for the metabolism of many tricyclic antidepressant medications and most antipsychotic drugs. However, studies have found that one-third of Asian Americans and African Americans have a genetic alteration that decreases the metabolic rate of the IID6 isoenzyme, leading to a greater risk of side effects and toxicity. The CYP2D6 enzyme, important for the way in which the liver clears many drugs from the body, varies greatly between individuals in ways that can be ethnically specific.
Though enzyme activity is genetically influenced, it can also be altered by cultural and environmental factors such as diet, the use of other medications, alcohol and disease states.
Differences in pharmacodynamics
If two individuals have the same blood level of a medication there may still be differences in the way that the body responds due to pharmacodynamic differences; pharmacodynamic responses may also be influenced by racial and cultural factors.
In addition to biology and environment, culturally determined attitudes toward illness may affect how an individual responds to psychiatric medication.
Cultural factors
In addition to biology and environment, culturally determined attitudes toward illness and its treatment may affect how an individual responds to psychiatric medication. Some cultures see suffering and illness as unavoidable and not amenable to medication, while others treat symptoms with polypharmacy, oft
|
https://en.wikipedia.org/wiki/Limitation%20of%20size
|
In the philosophy of mathematics, specifically the philosophical foundations of set theory, limitation of size is a concept developed by Philip Jourdain and/or Georg Cantor to avoid Cantor's paradox. It identifies certain "inconsistent multiplicities", in Cantor's terminology, that cannot be sets because they are "too large". In modern terminology these are called proper classes.
Use
The axiom of limitation of size is an axiom in some versions of von Neumann–Bernays–Gödel set theory or Morse–Kelley set theory. This axiom says that any class that is not "too large" is a set, and a set cannot be "too large". "Too large" is defined as being large enough that the class of all sets can be mapped one-to-one into it.
References
Philosophy of mathematics
History of mathematics
Basic concepts in infinite set theory
|
https://en.wikipedia.org/wiki/Overdispersion
|
In statistics, overdispersion is the presence of greater variability (statistical dispersion) in a data set than would be expected based on a given statistical model.
A common task in applied statistics is choosing a parametric model to fit a given set of empirical observations. This necessitates an assessment of the fit of the chosen model. It is usually possible to choose the model parameters in such a way that the theoretical population mean of the model is approximately equal to the sample mean. However, especially for simple models with few parameters, theoretical predictions may not match empirical observations for higher moments. When the observed variance is higher than the variance of a theoretical model, overdispersion has occurred. Conversely, underdispersion means that there was less variation in the data than predicted. Overdispersion is a very common feature in applied data analysis because in practice, populations are frequently heterogeneous (non-uniform) contrary to the assumptions implicit within widely used simple parametric models.
Examples
Poisson
Overdispersion is often encountered when fitting very simple parametric models, such as those based on the Poisson distribution. The Poisson distribution has one free parameter and does not allow for the variance to be adjusted independently of the mean. The choice of a distribution from the Poisson family is often dictated by the nature of the empirical data. For example, Poisson regression analysis is commonly used to model count data. If overdispersion is a feature, an alternative model with additional free parameters may provide a better fit. In the case of count data, a Poisson mixture model like the negative binomial distribution can be proposed instead, in which the mean of the Poisson distribution can itself be thought of as a random variable drawn – in this case – from the gamma distribution thereby introducing an additional free parameter (note the resulting negative binomial distribution
|
https://en.wikipedia.org/wiki/Phytogeography
|
Phytogeography (from Greek φυτόν, phytón = "plant" and γεωγραφία, geographía = "geography" meaning also distribution) or botanical geography is the branch of biogeography that is concerned with the geographic distribution of plant species and their influence on the earth's surface. Phytogeography is concerned with all aspects of plant distribution, from the controls on the distribution of individual species ranges (at both large and small scales, see species distribution) to the factors that govern the composition of entire communities and floras. Geobotany, by contrast, focuses on the geographic space's influence on plants.
Fields
Phytogeography is part of a more general science known as biogeography. Phytogeographers are concerned with patterns and process in plant distribution. Most of the major questions and kinds of approaches taken to answer such questions are held in common between phyto- and zoogeographers.
Phytogeography in wider sense (or geobotany, in German literature) encompasses four fields, according with the focused aspect, environment, flora (taxa), vegetation (plant community) and origin, respectively:
plant ecology (or mesology – however, the physiognomic-ecological approach on vegetation and biome study are also generally associated with this field);
plant geography (or phytogeography in strict sense, chorology, floristics);
plant sociology (or phytosociology, synecology – however, this field does not prescind from flora study, as its approach to study vegetation relies upon a fundamental unit, the plant association, which is defined upon flora).
historical plant geography (or paleobotany, paleogeobotany)
Phytogeography is often divided into two main branches: ecological phytogeography and historical phytogeography. The former investigates the role of current day biotic and abiotic interactions in influencing plant distributions; the latter are concerned with historical reconstruction of the origin, dispersal, and extinction of taxa.
Ove
|
https://en.wikipedia.org/wiki/Aigo
|
Beijing Huaqi Information Digital Technology Co., Ltd, trading as Aigo (stylized as aigo), is a Chinese consumer electronics company. It is headquartered in the Ideal Plaza () in Haidian District, Beijing.
History
Beijing Huaqi Information Digital Technology Co Ltd (北京华旗资讯科技发展有限公司) is a consumer electronics manufacturer headquartered in Beijing. It was founded by Féng Jūn, who is the current president, in 1993. The company initially produced keyboards. aigo may be participating in a trend that sees Chinese nationals preferring to purchase locally produced durable goods.
Products
aigo's products include MIDs, digital media players, computer cases, digital cameras, cpu cooling fans, computer peripherals, and monitors.
Subsidiaries
aigo has 27 subsidiaries and several R&D facilities. An incomplete list of aigo's subsidiaries can be found here.
aigo Music
Established in 1993 and located in Beijing, aigo Music operates a digital music service much like iTunes. The first of its kind in China, it is, as of 2009, the biggest portal for legal downloading of music in the country. Strategic partnerships with Warner Music, EMI and Sony allow a wide range of music to be offered at 0.99 yuan per song.
Beijing aifly Education and Technology Co Ltd
aigo set up this English as a Second Language brand with help from Crazy English founder Li Yang.
Beijing aigo Digital Animation Institution
An aigo subsidiary that specializes in 3D animated films.
Huaqi Information Technology (Singapore) Pte Ltd
Set up in October 2003, it operates two official aigo outlet stores in Singapore.
Shenzhen aigo R&D Co Ltd
Established in 2006, this Shenzhen-based research and development facility focuses on the development of mobile multimedia software.
Sponsorships
aigo is a sponsor of a number of sporting events, the majority involving automobile racing.
Motorsport
aigo was an official partner of the Vodafone McLaren Mercedes Formula One team.
As of 2008, aigo sponsors Chinese driver "Frankie"
|
https://en.wikipedia.org/wiki/Stealth%20wallpaper
|
For computer network security, stealth wallpaper is a material designed to prevent an indoor Wi-Fi network from extending or "leaking" to the outside of a building, where malicious persons may attempt to eavesdrop or attack a network. While it is simple to prevent all electronic signals from passing through a building by covering the interior with metal, stealth wallpaper accomplishes the more difficult task of blocking Wi-Fi signals while still allowing cellphone signals to pass through.
The first stealth wallpaper was originally designed by UK defense contractor BAE Systems
In 2012, The Register reported that a commercial wallpaper had been developed by Institut Polytechnique Grenoble and the Centre Technique du Papier with planned sale in 2013. This wallpaper blocks three selected Wi-Fi frequencies. Nevertheless, it does allow GSM and 4G signals to pass through the network, therefore allowing cell phone use to remain unaffected by the wallpaper.
See also
Electromagnetic shielding
Faraday cage
TEMPEST
Wallpaper
Wireless security
References
External links
Azcom: Stealth Wallpaper Prevents Wi-Fi Signals Escaping without Blocking Mobile Phone Signals
The Register: Wifi Blocking Wallpaper
BAE Systems research and development
Computer network security
Wi-Fi
|
https://en.wikipedia.org/wiki/Alor%20Setar%20Tower
|
Alor Setar Tower (), also known as Kedah Tower is a 4-story, 165.5-meter-tall telecommunication tower in Alor Setar, Kedah, Malaysia, It is Malaysia's third tallest tower, the tallest structure in the state and the tallest structure in the city.
Apart from serving the role of a telecommunication tower, it also caters as a tourist destination for the town. The tower also houses some restaurants and a souvenir shop. The tower is an observatory tower to look for the crescent moon to mark the beginning of Muslim months such as Ramadhan, Shawwal, and Zulhijjah, to celebrate Ramadhan, Hari Raya Aidilfitri and Hari Raya Aidiladha, respectively.
The observation deck is at a height of from the base of the structure.
Also, the open deck or skydeck is at a height of and the antenna tower is with the height of .
History
Before Alor Setar Tower was built, the tallest structure in Kedah was Holiday Villa Alor Setar, which is . Located at the Alor Setar City Centre, it was built in 1994. It is also the second structure in Northern Region of Peninsular Malaysia to surpass after Penang's Komtar. Alor Setar Tower was started in 1994, topped-out in 1995, it surpassed the previous Holiday Villa Alor Setar, became the third to surpass . The tower was completed in 1996. Opened in 14 August 1997 by Mahathir Mohamad, who was the prime minister at the time.
Following the completion of the Alor Setar Tower, many high-rise and low-rise buildings started taking shape, including Amansuri Residences, Aman Central, SADA Tower, G Residence Alor Setar, VIVRE Residence, AS100, and AMEX Alor Mengkudu.
Gallery
Channels listed by frequency
Television
TV Alhijrah UHF 559.25 MHz (Ch 32)
Radio
Fly FM 99.1 MHz
Buletin FM 107.3 MHz
Menara Alor Setar is a telecommunication tower in Alor Setar, Kedah and a popular tourist destination in the northern region. With a total height of , it is the third tallest telecommunication tower in Malaysia (behind the Kuala Lumpur Tower, and the newly opened Kua
|
https://en.wikipedia.org/wiki/The%20Monkey%20Suit
|
"The Monkey Suit" is the twenty-first and penultimate episode of the seventeenth season of the American animated television series The Simpsons. It originally aired on the Fox network in the United States on May 14, 2006. In the episode, Ned Flanders is shocked after seeing a new display at the museum about evolution. Together with Reverend Lovejoy, he spreads the religious belief of creationism in Springfield, and at a later town meeting, teaching evolution is made illegal. As a result, Lisa decides to hold secret classes for people interested in evolution. However, she is quickly arrested and a trial against her is initiated.
J. Stewart Burns wrote "The Monkey Suit", for which he received inspiration from the 1925 Scopes Monkey Trial. The episode features a few references to this legal case, as well as several references to popular culture. Many analysts have commented on the episode's treatment of the creation–evolution controversy, a dispute about the origin of humanity between those who support a creationist view based upon their religious beliefs, versus those who accept evolution, as supported by scientific evidence.
Critics have given the episode generally positive reviews, praising it for its satire of the creation-evolution debate. "The Monkey Suit" has won an award from the Independent Investigations Group (IIG) for being "one of those rare shows in the media that encourage science, critical thinking, and ridicule those shows that peddle pseudoscience and superstition." In 2007, a scene from the episode was highlighted in the scientific journal Nature.
Plot
Lisa decides to bring the family to the museum to see a weaving exhibit for her summer vacation, but they soon discover that it has been replaced by a "History of Weapons" exhibit, sponsored by Kellogg's. Faced with an incredibly long line, Homer notices Ned Flanders and his sons at the front of the line and cuts in front of them. Everyone else starts taking advantage of Ned’s kindness as well until
|
https://en.wikipedia.org/wiki/Levant%20Mine%20and%20Beam%20Engine
|
Levant Mine and Beam Engine is a National Trust property at Trewellard, Pendeen, near St Just, Cornwall, England, UK. Its main attraction is that it has the world's only Cornish beam engine still operated by steam on its original site. There is also a visitor centre, a short underground tour, and the South West Coast Path leads to Botallack Mine, via a cliff-top footpath.
In 1919 the engine used to transport men between the different levels of the mine failed, leading to the deaths of thirty-one men. Since 2006, the area has been part of the UNESCO World Heritage Site, Cornwall and West Devon Mining Landscape.
Site
The property is on the site of the former Levant Mine, established in 1820 and closed in 1930, where tin and copper ores were raised. The mine reached a depth of about 600 metres. It got the nickname "mine under the sea", because tunnels were driven up to 2.5 km from the cliffs under the sea. The surviving beam engine was built by Harvey's of Hayle.
History
The mine yields both copper and tin and was opened in 1820 with twenty shares of £20 each. From first opening, to circa 1883, the mine gave a profit of £171,000 from approximately £1,300,000 worth of ore. In 1882 the mine was taken over by new owners on a 21 year lease, replaced machinery and improved the surface-works.
In 1883 three shafts were open. One shaft is occupied by the man-engine, a second by a pumping-engine and the third for hauling out the skips. Since the introductions of skips, for bringing ore to the surface, two shafts were abandoned. There was six engines on site,
pumping-engine, cylinder – pumps water from the mine
stamping, cylinder – breaks up the ore
winding-engine or whim, cylinder – raises the ore to the surface
man-engine, cylinder
crushing-machine, cylinder
winding-engine, cylinder.
A description of the working conditions of the mine was described in The Cornishman newspaper in 1883. Around 366 men, boys, and girls were employed compared with about 600
|
https://en.wikipedia.org/wiki/Arc%20converter
|
The arc converter, sometimes called the arc transmitter, or Poulsen arc after Danish engineer Valdemar Poulsen who invented it in 1903, was a variety of spark transmitter used in early wireless telegraphy. The arc converter used an electric arc to convert direct current electricity into radio frequency alternating current. It was used as a radio transmitter from 1903 until the 1920s when it was replaced by vacuum tube transmitters. One of the first transmitters that could generate continuous sinusoidal waves, it was one of the first technologies used to transmit sound (amplitude modulation) by radio. It is on the list of IEEE Milestones as a historic achievement in electrical engineering.
History
Elihu Thomson discovered that a carbon arc shunted with a series tuned circuit would "sing". This "singing arc" was probably limited to audio frequencies. Bureau of Standards credits William Duddell with the shunt resonant circuit around 1900.
The English engineer William Duddell discovered how to make a resonant circuit using a carbon arc lamp. Duddell's "musical arc" operated at audio frequencies, and Duddell himself concluded that it was impossible to make the arc oscillate at radio frequencies.
Valdemar Poulsen succeeded in raising the efficiency and frequency to the desired level. Poulsen's arc could generate frequencies of up to 200 kilohertz and was patented in 1903.
After a few years of development the arc technology was transferred to Germany and Great Britain in 1906 by Poulsen, his collaborator Peder Oluf Pedersen and their financial backers. In 1909 the American patents as well as a few arc converters were bought by Cyril Frank Elwell. The subsequent development in Europe and the United States was rather different, since in Europe there were severe difficulties for many years implementing the Poulsen technology, whereas in the United States an extended commercial radiotelegraph system was soon established with the Federal Telegraph Company. Later the US Nav
|
https://en.wikipedia.org/wiki/Fixation%20index
|
The fixation index (FST) is a measure of population differentiation due to genetic structure. It is frequently estimated from genetic polymorphism data, such as single-nucleotide polymorphisms (SNP) or microsatellites. Developed as a special case of Wright's F-statistics, it is one of the most commonly used statistics in population genetics. Its values range from 0 to 1, with 0.15 being substantially differentiated and 1 being complete differentiation.
Interpretation
This comparison of genetic variability within and between populations is frequently used in applied population genetics. The values range from 0 to 1. A zero value implies complete panmixis; that is, that the two populations are interbreeding freely. A value of one implies that all genetic variation is explained by the population structure, and that the two populations do not share any genetic diversity.
For idealized models such as Wright's finite island model, FST can be used to estimate migration rates. Under that model, the migration rate is
,
where is the migration rate per generation, and is the mutation rate per generation.
The interpretation of FST can be difficult when the data analyzed are highly polymorphic. In this case, the probability of identity by descent is very low and FST can have an arbitrarily low upper bound, which might lead to misinterpretation of the data. Also, strictly speaking FST is not a distance in the mathematical sense, as it does not satisfy the triangle inequality.
For populations of plants which clearly belong to the same species, values of FST greater than 15% are considered "great" or "significant" differentiation, while values below 5% are considered "small" or "insignificant" differentiation.
Values for mammal populations between subspecies, or closely related species, typical values are of the order of 5% to 20%. FST between the Eurasian and North American populations of the gray wolf were reported at 9.9%, those between the Red wolf and Gray wolf popu
|
https://en.wikipedia.org/wiki/Otto%20Schott
|
Friedrich Otto Schott (1851–1935) was a German chemist, glass technologist, and the inventor of borosilicate glass. Schott systematically investigated the relationship between the chemical composition of the glass and its properties. In this way, he solved fundamental problems in glass properties, identifying compositions with optical properties that approach the theoretical limit. Schott's findings were a major advance in the optics for microscopy and optical astronomy. His work has been described as "a watershed in the history of glass composition".
Early life and education
Schott was the son of a window glass maker, Simon Schott. His mother was Karoline Schott. From 1870 to 1873 Schott studied chemical technology at the technical college in Aachen and at the University of Würzburg and at the University of Leipzig. He earned a doctorate in chemistry at Friedrich Schiller University of Jena, specializing in glass science. His doctoral thesis was entitled “Contributions to the Theory and Practice of Glass Fabrication” (1875).
Scientific contributions
In 1879, Schott developed a new lithium-based glass that possessed novel optical properties. Schott shared this discovery with Ernst Abbe, a professor of physics at Jena University whose comments on glass had stimulated Schott's interest in the subject.
Not long after Schott had completed his formal university training, he had become aware that Abbe had articulated the deficiencies in glass that was available at the time. The deficiencies were particularly acute in scientific instruments for which optical performance of the glass in lenses such as for telescopes and microscopes. Scientifically, as the magnification power of the lenses were increased, chromatic aberration became large. Chromatic aberration causes the optical quality of the visual image to become dependent on the color of the light, resulting in a significant limitation of the scientific instrument.
In response to Abbe's scientific provocation, Scho
|
https://en.wikipedia.org/wiki/Iron%28II%29%20gluconate
|
Iron(II) gluconate, or ferrous gluconate, is a black compound often used as an iron supplement. It is the iron(II) salt of gluconic acid. It is marketed under brand names such as Fergon, Ferralet and Simron.
Uses
Medical
Ferrous gluconate is effectively used in the treatment of hypochromic anemia. The use of this compound compared with other iron preparations results in satisfactory reticulocyte responses, a high percentage utilization of iron, and daily increase in hemoglobin that a normal level occurs in a reasonably short time.
Food additive
Ferrous gluconate is also used as a food additive when processing black olives. It is represented by the food labeling E number E579 in Europe. It imparts a uniform jet black color to the olives.
Toxicity
Ferrous gluconate may be toxic in case of overdose. Children may show signs of toxicity with ingestions of 10–20 mg/kg of elemental iron. Serious toxicity may result from ingestions of more than 60 mg/kg. Iron exerts both local and systemic effects: it is corrosive to the gastrointestinal mucosa, it can have a negative impact on the heart and blood (dehydration, low blood pressure, fast and weak pulse, shock), lungs, liver, gastrointestinal system (diarrhea, nausea, vomiting blood), nervous system (chills, dizziness, coma, convulsions, headache), and skin (flushing, loss of color, bluish-colored lips and fingernails). The symptoms may disappear in a few hours, but then emerge again after 1 or more days.
See also
Acceptable daily intake
Iron poisoning
References
Color fixers
Food additives
Iron(II) compounds
E-number additives
|
https://en.wikipedia.org/wiki/Critical%20heat%20flux
|
In the study of heat transfer, critical heat flux (CHF) is the heat flux at which boiling ceases to be an effective form of transferring heat from a solid surface to a liquid.
Description
Boiling systems are those in which liquid coolant absorbs energy from a heated solid surface and undergoes a change in phase. In flow boiling systems, the saturated fluid progresses through a series of flow regimes as vapor quality is increased. In systems that utilize boiling, the heat transfer rate is significantly higher than if the fluid were a single phase (i.e. all liquid or all vapor). The more efficient heat transfer from the heated surface is due to heat of vaporization and sensible heat. Therefore, boiling heat transfer has played an important role in industrial heat transfer processes such as macroscopic heat transfer exchangers in nuclear and fossil power plants, and in microscopic heat transfer devices such as heat pipes and microchannels for cooling electronic chips.
The use of boiling as a means of heat removal is limited by a condition called critical heat flux (CHF). The most serious problem that can occur around CHF is that the temperature of the heated surface may increase dramatically due to significant reduction in heat transfer. In industrial applications such as electronics cooling or instrumentation in space, the sudden increase in temperature may possibly compromise the integrity of the device.
Two-phase heat transfer
The convective heat transfer between a uniformly heated wall and the working fluid is described by Newton's law of cooling:
where represents the heat flux, represents the proportionally constant called the heat transfer coefficient, represents the wall temperature and represents the fluid temperature. If decreases significantly due to the occurrence of the CHF condition, will increase for fixed and while will decrease for fixed .
Modes of CHF
The understanding of CHF phenomenon and an accurate prediction of the CHF condition
|
https://en.wikipedia.org/wiki/Entomopathogenic%20nematode
|
Entomopathogenic nematodes (EPN) are a group of nematodes (thread worms), that cause death to insects. The term entomopathogenic has a Greek origin, with entomon, meaning insect, and pathogenic, which means causing disease. They are animals that occupy a bio control middle ground between microbial pathogens and predator/parasitoids. Although many other parasitic thread worms cause diseases in living organisms (sterilizing or otherwise debilitating their host), entomopathogenic nematodes are specific in only infecting insects. Entomopathogenic nematodes (EPNs) live parasitically inside the infected insect host, and so they are termed as endoparasitic. They infect many different types of insects living in the soil like the larval forms of moths, butterflies, flies and beetles as well as adult forms of beetles, grasshoppers and crickets. EPNs have been found all over the world in a range of ecologically diverse habitats. They are highly diverse, complex and specialized. The most commonly studied entomopathogenic nematodes are those that can be used in the biological control of harmful insects, the members of Steinernematidae and Heterorhabditidae. They are the only insect-parasitic nematodes possessing an optimal balance of biological control attributes.
Classification
Life cycle
Because of their economic importance, the life cycles of the genera belonging to families Heterorhabditidae and Steinernematidae are well studied. Although not closely related, phylogenetically, both share similar life histories (Poinar 1993). The cycle begins with an infective juvenile, whose only function is to seek out and infect new hosts. When a host has been located, the nematodes penetrate into the insect body cavity, usually via natural body openings (mouth, anus, spiracles) or areas of thin cuticle. (Shapiro-Ilan, David I., and Randy Gaugler. "Nematodes.") After entering an insect, infective juveniles release an associated mutualistic bacterium from their gut which multiplies rapi
|
https://en.wikipedia.org/wiki/Franz%E2%80%93Keldysh%20effect
|
The Franz–Keldysh effect is a change in optical absorption by a semiconductor when an electric field is applied. The effect is named after the German physicist Walter Franz and Russian physicist Leonid Keldysh.
Karl W. Böer observed first the shift of the optical absorption edge with electric fields during the discovery of high-field domains and named this the Franz-effect. A few months later, when the English translation of the Keldysh paper became available, he corrected this to the Franz–Keldysh effect.
As originally conceived, the Franz–Keldysh effect is the result of wavefunctions "leaking" into the band gap. When an electric field is applied, the electron and hole wavefunctions become Airy functions rather than plane waves. The Airy function includes a "tail" which extends into the classically forbidden band gap. According to Fermi's golden rule, the more overlap there is between the wavefunctions of a free electron and a hole, the stronger the optical absorption will be. The Airy tails slightly overlap even if the electron and hole are at slightly different potentials (slightly different physical locations along the field). The absorption spectrum now includes a tail at energies below the band gap and some oscillations above it. This explanation does, however, omit the effects of excitons, which may dominate optical properties near the band gap.
The Franz–Keldysh effect occurs in uniform, bulk semiconductors, unlike the quantum-confined Stark effect, which requires a quantum well. Both are used for electro-absorption modulators. The Franz–Keldysh effect usually requires hundreds of volts, limiting its usefulness with conventional electronics – although this is not the case for commercially available Franz–Keldysh-effect electro-absorption modulators that use a waveguide geometry to guide the optical carrier.
Effect on modulation spectroscopy
The absorption coefficient is related to the dielectric constant (especially the complex part 2). From Maxwell's
|
https://en.wikipedia.org/wiki/List%20of%20haplogroups%20of%20historic%20people
|
This is a list of haplogroups of historic people. Haplogroups can be determined from the remains of historical figures, or derived from genealogical DNA tests of people who trace their direct maternal or paternal ancestry to a noted historical figure. Some contemporary notable figures have made their test results public in the course of news programs or documentaries about this topic; they may be included in this list too.
MtDNA results indicate direct maternal descent while Y-DNA results indicate direct paternal descent; these are only two of many lines of descent. Scientists make inferences of descent as hypotheses which could be disproved or modified by future research.
Ancient samples
These are results from 'ancient' samples, those collected from the remains or reputed remains of the person. Because mtDNA breaks down more slowly than nuclear DNA, it is often possible to obtain mtDNA results where other testing fails.
Birger Magnusson
Birger Jarl, the founder of Stockholm, the modern capital of Sweden, belonged to Y Haplogroup I-M253, according to Andreas Carlsson at the National Board of Forensic Medicine of Sweden. Birger Magnusson was the ancestor of a line of kings of both Sweden and Norway, starting with his son, Valdemar, King of Sweden.
Gaodang King Korguz (高唐王=趙王 闊裏吉思)
Noble burials of Mongols in the Yuan dynasty in Shuzhuanglou Site (northernmost Hebei, China, 700YBP) were excavated. All three men excavated belong to Y haplogroup Q, with subclade not analysed.
The most principal occupant, Gaodang King Korguz, had mtDNA of haplogroup D4m2. Two others' mtDNA are A
Korguz () was the son of a princess of Kublai Khan and he was the king of the Ongud and a descendant of Gok-Turk. The Ongud claimed descent from the Shatuo, prominent in the era of the Five Dynasties and Ten Kingdoms period. His two wives were all princesses of Yuan Dynasty. It was very important for the Yuan dynasty to maintain marriage-alliance with the Onguds, which had been very i
|
https://en.wikipedia.org/wiki/Vacuum%20engineering
|
Vacuum engineering is the field of engineering that deals with the practical use of vacuum in industrial and scientific applications. Vacuum may improve the productivity and performance of processes otherwise carried out at normal air pressure, or may make possible processes that could not be done in the presence of air. Vacuum engineering techniques are widely applied in materials processing such as drying or filtering, chemical processing, application of metal coatings to objects, manufacture of electron devices and incandescent lamps, and in scientific research.
Vacuum techniques vary depending on the desired vacuum pressure to be achieved. For a "rough" vacuum, over 100 Pascals pressure, conventional methods of analysis, materials, pumps and measuring instruments can be used, whereas ultrahigh vacuum systems use specialized equipment to achieve pressures below one-millionth of one Pascal. At such low pressures, even metals may emit enough gas to cause serious contamination.
Design and mechanism
Vacuum systems usually consist of gauges, vapor jet and pumps, vapor traps and valves along with other extensional piping. A vessel that is operating under vacuum system may be any of these types such as processing tank, steam simulator, particle accelerator, or any other type of space that has an enclosed chamber to maintain the system in less than atmospheric gas pressure. Since a vacuum is created in an enclosed chamber, the consideration of being able to withstand external atmospheric pressure are the usual precaution for this type of design. Along with the effect of buckling or collapsing, the outer shell of vacuum chamber will be carefully evaluated and any sign of deterioration will be corrected by the increase of thickness of the shell itself. The main materials used for vacuum design are usually mild steel, stainless steel, and aluminum. Other sections such as glass are used for gauge glass, view ports, and sometimes electrical insulation. The interior of
|
https://en.wikipedia.org/wiki/Linnaean%20enterprise
|
The Linnaean enterprise is the task of identifying and describing all living species. It is named after Carl Linnaeus, a Swedish botanist, ecologist and physician who laid the foundations for the modern scheme of taxonomy.
As of 2006, the Linnaean enterprise is considered to be barely begun. There are estimated to be 10 million living species, but only about 1.5-1.8 million have been even named, and fewer than 1% of these have been studied enough to understand the basics of their ecological roles. Linnaean enterprise plays a larger role in applied science and basic science. With applied science, it can assist in finding new natural products and species (bioprospecting) and effective conservation practices. It allows for an understanding of evolutionary biology and how ecosystems function in basic science.
The cost of completing the Linnaean Enterprise has been estimated at US $5 billion.
Name
Carl Linnaeus (1707–1778) was one of the most well known natural scientists of his time. Very unsatisfied with the contemporary way of naming living things, he was responsible for creating the binomial nomenclature system still used in science to name species of organisms. Linnaeus's work laid the basis of modern taxonomy. As part of his work, Linnaeus formally described and classified numerous species of plants and animals, and created binomial (scientific) names that still are used today for many of the most common species in Europe. Notably, Linnaeus's taxonomic system was the first where humans were taxonomically grouped with apes, classifying both genus Homo as well as Simia (now defunct and replaced by several other genera) to be members of order Primates.
See also
Catalogue of Life
Encyclopedia of Life
Wikispecies
References
Sources
Edward O. Wilson, A Global Biodiversity Map, Science 29 September 2000: Vol. 289. no. 5488, p. 2279
Taxonomy (biology)
Carl Linnaeus
|
https://en.wikipedia.org/wiki/Position%20angle
|
In astronomy, position angle (usually abbreviated PA) is the convention for measuring angles on the sky. The International Astronomical Union defines it as the angle measured relative to the north celestial pole (NCP), turning positive into the direction of the right ascension. In the standard (non-flipped) images, this is a counterclockwise measure relative to the axis into the direction of positive declination.
In the case of observed visual binary stars, it is defined as the angular offset of the secondary star from the primary relative to the north celestial pole.
As the example illustrates, if one were observing a hypothetical binary star with a PA of 135°, that means an imaginary line in the eyepiece drawn from the north celestial pole to the primary (P) would be offset from the secondary (S) such that the angle would be 135°.
When graphing visual binaries, the NCP is, as in the illustration, normally drawn from the center point (origin) that is the Primary downward–that is, with north at bottom–and PA is measured counterclockwise. Also, the direction of the proper motion can, for example, be given by its position angle.
The definition of position angle is also applied to extended objects like galaxies, where it refers to the angle made by the major axis of the object with the NCP line.
Nautics
The concept of the position angle is inherited from nautical navigation on the oceans, where the optimum compass course is the course from a known position to a target position with minimum effort. Setting aside the influence of winds and ocean currents, the optimum course is the course of smallest distance between the two positions on the ocean surface. Computing the compass course is known as the inverse geodetic problem.
This article considers only the abstraction of minimizing the distance between and traveling on the surface of a sphere with some radius : In which direction angle relative to North should the ship steer to reach the target position?
Se
|
https://en.wikipedia.org/wiki/Dehn%20plane
|
In geometry, Max Dehn introduced two examples of planes, a semi-Euclidean geometry and a non-Legendrian geometry, that have infinitely many lines parallel to a given one that pass through a given point, but where the sum of the angles of a triangle is at least . A similar phenomenon occurs in hyperbolic geometry, except that the sum of the angles of a triangle is less than . Dehn's examples use a non-Archimedean field, so that the Archimedean axiom is violated. They were introduced by and discussed by .
Dehn's non-archimedean field Ω(t)
To construct his geometries, Dehn used a non-Archimedean ordered Pythagorean field Ω(t), a Pythagorean closure of the field of rational functions R(t), consisting of the smallest field of real-valued functions on the real line containing the real constants, the identity function t (taking any real number to itself) and closed under the operation . The field Ω(t) is ordered by putting x > y if the function x is larger than y for sufficiently large reals. An element x of Ω(t) is called finite if m < x < n for some integers m, n, and is called infinite otherwise.
Dehn's semi-Euclidean geometry
The set of all pairs (x, y), where x and y are any (possibly infinite) elements of the field Ω(t), and with the usual metric
which takes values in Ω(t), gives a model of Euclidean geometry. The parallel postulate is true in this model, but if the deviation from the perpendicular is infinitesimal (meaning smaller than any positive rational number), the intersecting lines intersect at a point that is not in the finite part of the plane. Hence, if the model is restricted to the finite part of the plane (points (x,y) with x and y finite), a geometry is obtained in which the parallel postulate fails but the sum of the angles of a triangle is . This is Dehn's semi-Euclidean geometry. It is discussed in .
Dehn's non-Legendrian geometry
In the same paper, Dehn also constructed an example of a non-Legendrian geometry where there are infini
|
https://en.wikipedia.org/wiki/Bacterial%20cell%20structure
|
The bacterium, despite its simplicity, contains a well-developed cell structure which is responsible for some of its unique biological structures and pathogenicity. Many structural features are unique to bacteria and are not found among archaea or eukaryotes. Because of the simplicity of bacteria relative to larger organisms and the ease with which they can be manipulated experimentally, the cell structure of bacteria has been well studied, revealing many biochemical principles that have been subsequently applied to other organisms.
Cell morphology
Perhaps the most elemental structural property of bacteria is their morphology (shape). Typical examples include:
coccus (circle or spherical)
bacillus (rod-like)
coccobacillus (between a sphere and a rod)
spiral (corkscrew-like)
filamentous (elongated)
Cell shape is generally characteristic of a given bacterial species, but can vary depending on growth conditions. Some bacteria have complex life cycles involving the production of stalks and appendages (e.g. Caulobacter) and some produce elaborate structures bearing reproductive spores (e.g. Myxococcus, Streptomyces). Bacteria generally form distinctive cell morphologies when examined by light microscopy and distinct colony morphologies when grown on Petri plates.
Perhaps the most obvious structural characteristic of bacteria is (with some exceptions) their small size. For example, Escherichia coli cells, an "average" sized bacterium, are about 2 µm (micrometres) long and 0.5 µm in diameter, with a cell volume of 0.6–0.7 μm3. This corresponds to a wet mass of about 1 picogram (pg), assuming that the cell consists mostly of water. The dry mass of a single cell can be estimated as 23% of the wet mass, amounting to 0.2 pg. About half of the dry mass of a bacterial cell consists of carbon, and also about half of it can be attributed to proteins. Therefore, a typical fully grown 1-liter culture of Escherichia coli (at an optical density of 1.0, corresponding to c. 109
|
https://en.wikipedia.org/wiki/LIGA
|
LIGA is a fabrication technology used to create high-aspect-ratio microstructures. The term is a German acronym for – lithography, electroplating, and molding.
Overview
The LIGA consists of three main processing steps; lithography, electroplating and molding.
There are two main LIGA-fabrication technologies, X-Ray LIGA, which uses X-rays produced by a synchrotron to create high aspect ratio structures, and UV LIGA, a more accessible method which uses ultraviolet light to create structures with relatively low aspect ratios.
Notable characteristics of X-ray LIGA-fabricated structures include:
high aspect ratios on the order of 100:1
parallel side walls with a flank angle on the order of 89.95°
smooth side walls with = , suitable for optical mirrors
structural heights from tens of micrometers to several millimeters
structural details on the order of micrometers over distances of centimeters
X-Ray LIGA
X-Ray LIGA is a fabrication process in microtechnology that was developed in the early 1980s
by
a team under the leadership of Erwin Willy Becker and Wolfgang Ehrfeld at the Institute for Nuclear Process Engineering
(Institut für Kernverfahrenstechnik, IKVT) at the Karlsruhe Nuclear Research Center, since renamed to the Institute for Microstructure Technology (Institut für Mikrostrukturtechnik, IMT) at the Karlsruhe Institute of Technology (KIT).
LIGA was one of the first major techniques to allow on-demand manufacturing of high-aspect-ratio structures (structures that are much taller than wide) with lateral precision below one micrometer.
In the process, an X-ray sensitive polymer photoresist, typically PMMA, bonded to an electrically conductive substrate, is exposed to parallel beams of high-energy X-rays from a synchrotron radiation source through a mask partly covered with a strong X-ray absorbing material. Chemical removal of exposed (or unexposed) photoresist results in a three-dimensional structure, which can be filled by the electrodeposition of me
|
https://en.wikipedia.org/wiki/Self%20defined%20ethnicity
|
Self defined ethnicity (SDE) codes are a set of codes used by the Home Office in the United Kingdom to classify an individual's ethnicity according to that person's self-definition.
The codes are also called "18 + 1" codes, as there are 18 of them, plus one code (NS) for "not stated". In addition to the previously used 16+1 codes, they contain the categories W3 and O2, while A4 is now replacing O1 (Chinese).
The code system originated in the United Kingdom Census 2001 based on Recommendation 61 of the Stephen Lawrence Inquiry Report (SLIR).
British police forces are required to use the SDE 18+1 codes (as opposed to the commonly used radio shorthand IC codes) when spoken contact has taken place and an individual has been given an opportunity to state their self-perceived ethnicity.
List of SDE codes
White
W1 – British
W2 – Irish
W3 – Gypsy or Irish Traveller
W9 – Any other White background
Mixed or Multiple ethnic groups
M1 – White and Black Caribbean
M2 – White and Black African
M3 – White and Asian
M9 – Any other Mixed or Multiple background
Asian or Asian British
A1 – Indian
A2 – Pakistani
A3 – Bangladeshi
A4 – Chinese
A9 – Any other Asian background
Black, Black British, Caribbean or African
B1 – Caribbean
B2 – African
B9 – Any other Black, Black British or Caribbean background
Other ethnic groups
O2 – Arab
O9 – Any other ethnic group
Not stated
NS – Not Stated.
See also
Classification of ethnicity in the United Kingdom
IC codes
External links
Ethnicity facts and figures. Government data about the UK's different ethnic groups.
References
Demographics of the United Kingdom
Encodings
Law enforcement in the United Kingdom
|
https://en.wikipedia.org/wiki/Weight%20distribution
|
Weight distribution is the apportioning of weight within a vehicle, especially cars, airplanes, and trains. Typically, it is written in the form x/y, where x is the percentage of weight in the front, and y is the percentage in the back.
In a vehicle which relies on gravity in some way, weight distribution directly affects a variety of vehicle characteristics, including handling, acceleration, traction, and component life. For this reason weight distribution varies with the vehicle's intended usage. For example, a drag car maximizes traction at the rear axle while countering the reactionary pitch-up torque. It generates this counter-torque by placing a small amount of counterweight at a great distance forward of the rear axle.
In the airline industry, load balancing is used to evenly distribute the weight of passengers, cargo, and fuel throughout an aircraft, so as to keep the aircraft's center of gravity close to its center of pressure to avoid losing pitch control. In military transport aircraft, it is common to have a loadmaster as a part of the crew; their responsibilities include calculating accurate load information for center of gravity calculations, and ensuring cargo is properly secured to prevent its shifting.
In large aircraft and ships, multiple fuel tanks and pumps are often used, so that as fuel is consumed, the remaining fuel can be positioned to keep the vehicle balanced, and to reduce stability problems associated with the free surface effect.
In the trucking industry, individual axle weight limits require balancing the cargo when the gross vehicle weight nears the legal limit.
See also
Center of mass
Center of percussion
Load transfer
Mass distribution
Roll center
Tilt test
Weight transfer
References
External links
Weight Distribution Calculator
Aerospace engineering
Mass
Vehicle technology
|
https://en.wikipedia.org/wiki/Four-valued%20logic
|
In logic, a four-valued logic is any logic with four truth values. Several types of four-valued logic have been advanced.
Belnap
Nuel Belnap considered the challenge of question answering by computer in 1975. Noting human fallibility, he was concerned with the case where two contradictory facts were loaded into memory, and then a query was made. "We all know about the fecundity of contradictions in two-valued logic: contradictions are never isolated, infecting as they do the whole system." Belnap proposed a four-valued logic as a means of containing contradiction.
He called the table of values A4: Its possible values are true, false, both (true and false), and neither (true nor false). Belnap's logic is designed to cope with multiple information sources such that if only true is found then true is assigned, if only false is found then false is assigned, if some sources say true and others say false then both is assigned, and if no information is given by any information source then neither is assigned. These four values correspond to the elements of the power set based on {T, F}.
T is the supremum and F the infimum in the logical lattice where None and Both are in the wings. Belnap has this interpretation: "The worst thing is to be told something is false simpliciter. You are better off (it is one of your hopes) in either being told nothing about it, or being told both that it is true and also that it is false; while of course best of all is to be told that it is true." Belnap notes that "paradoxes of implication" (A&~A)→B and A→(B∨~B) are avoided in his 4-valued system.
Logical connectives
Belnap addressed the challenge of extending logical connectives to A4. Since it is the power set on {T, F}, the elements of A4 are ordered by inclusion making it a lattice with Both at the supremum and None at the infimum, and T and F on the wings. Referring to Dana Scott, he assumes the connectives are Scott-continuous or monotonic functions. First he expands negation by ded
|
https://en.wikipedia.org/wiki/Curious%20George%20%28TV%20series%29
|
Curious George is an American children's animated television series based on the children's book series of the same name for PBS Kids which features Jeff Bennett as the voice of Ted Shackelford (credited as "The Man with the Yellow Hat", formerly called that in the original series books and telefilm books). Frank Welker, who voiced George in the 2006 feature film, reprises the role in the series. The show premiered on PBS Kids in the fall of 2006, and originally ended after nine seasons on April 1, 2015 before returning in 2018.
Season 10 premiered on September 3, 2018 on Family Jr. in Canada. Seasons 10-13 debuted on NBCUniversal's streaming service Peacock in the United States when it launched in July 2020. Seasons 1-9 are available to stream for Peacock Premium subscribers since September 20, 2020, which is also available to stream on Hulu. Season 10 premiered on PBS on October 5 the same year.
Curious George is a production of Universal 1440 Entertainment (Universal Studios Family Productions before 2013), Imagine Entertainment, and WGBH-TV (WGBH Kids) (before season 13), and animated by Toon City. From seasons 1-9, each episode has two animated segments per half hour episode, and a short live-action segment after each. The live-action shorts illustrate and explain various concepts in math and science, and shows a class with kids engaging in experiments, that teach the math or science concept featured in the previous story. Season 10 eliminated them, leaving only the animated segments left.
Settings
City: George and the Man live in an apartment in the Big City. The actual name of the city is unknown but has some similarities to New York. However in the episode "Curious George Takes a Vacation", an airport worker mentions they're in Illinois meaning they possibly live in Chicago. The Doorman keeps a pigeon coop on the roof and is the guardian of Hundley, his dachshund dog. The apartment is near Endless Park, the museum where Professor Wiseman works, and the z
|
https://en.wikipedia.org/wiki/Cain%20and%20Abel%20%28software%29
|
Cain and Abel (often abbreviated to Cain) was a password recovery tool for Microsoft Windows. It could recover many kinds of passwords using methods such as network packet sniffing, cracking various password hashes by using methods such as dictionary attacks, brute force and cryptanalysis attacks.
Cryptanalysis attacks were done via rainbow tables which could be generated with the winrtgen.exe program provided with Cain and Abel.
Cain and Abel was maintained by Massimiliano Montoro and Sean Babcock.
Features
WEP cracking
Speeding up packet capture speed by wireless packet injection
Ability to record VoIP conversations
Decoding scrambled passwords
Calculating hashes
Traceroute
Revealing password boxes
Uncovering cached passwords
Dumping protected storage passwords
ARP spoofing
IP to MAC Address resolver
Network Password Sniffer
LSA secret dumper
Ability to crack:
LM & NTLM hashes
NTLMv2 hashes
Microsoft Cache hashes
Microsoft Windows PWL files
Cisco IOS – MD5 hashes
Cisco PIX – MD5 hashes
APOP – MD5 hashes
CRAM-MD5 MD5 hashes
OSPF – MD5 hashes
RIPv2 MD5 hashes
VRRP – HMAC hashes
Virtual Network Computing (VNC) Triple DES
MD2 hashes
MD4 hashes
MD5 hashes
SHA-1 hashes
SHA-2 hashes
RIPEMD-160 hashes
Kerberos 5 hashes
RADIUS shared key hashes
IKE PSK hashes
MSSQL hashes
MySQL hashes
Oracle and SIP hashes
Status with virus scanners
Some virus scanners (and browsers, e.g. Google Chrome 20.0.1132.47) detect Cain and Abel as malware.
Avast! detects it as "Win32:Cain-B [Tool]" and classifies it as "Other potentially dangerous program", while Microsoft Security Essentials detects it as "Win32/Cain!4_9_14" and classifies it as "Tool: This program has potentially unwanted behavior."
Even if Cain's install directory, as well as the word "Cain", are added to Avast's exclude list, the real-time scanner has been known to stop Cain from functioning. However, the latest version of Avast no longer blocks Cain.
Symantec (the developer of the
|
https://en.wikipedia.org/wiki/KNSN-TV
|
KNSN-TV (channel 21) is a primary sports-formatted independent television station in Reno, Nevada, United States, which has a secondary affiliation with MyNetworkTV. It is owned by Deerfield Media, which maintains joint sales and shared services agreements (JSA/SSA) with Sinclair Broadcast Group, owner of Fox affiliate KRXI-TV (channel 11), for the provision of certain services. Sinclair also manages NBC affiliate KRNV-DT (channel 4) under a separate JSA with Cunningham Broadcasting; however, Sinclair effectively owns KRNV as the majority of Cunningham's stock is owned by the family of deceased group founder Julian Smith. The three stations share studios on Vassar Street in Reno; KNSN-TV's transmitter is located on Red Hill between US 395 and SR 445 in Sun Valley, Nevada.
History
The station launched on October 11, 1981, as KAME-TV, an independent station airing movies (TV-21's The Big Movie), cartoons, westerns, and sitcoms. On October 9, 1986, it became a charter Fox affiliate. On January 16, 1995, KAME-TV picked up UPN on a secondary basis; it became a full-time UPN affiliate on January 1, 1996, after KRXI signed-on and took Fox. Between September 1996 and May 1997, the station was briefly owned by Raycom Media. With the 2006 shutdown and merge of The WB and UPN to form The CW, the station joined News Corporation–owned and Fox sister network MyNetworkTV on September 5, 2006.
On July 20, 2012, one day after Cox Media Group purchased WAWS and WTEV in Jacksonville, Florida, and KOKI-TV and KMYT-TV in Tulsa, Oklahoma, from Newport Television, Cox put KRXI-TV (along with the LMA for KAME-TV) and sister stations WTOV-TV in Steubenville, Ohio, WJAC-TV in Johnstown, Pennsylvania, and KFOX-TV in El Paso, Texas (all in markets that are smaller than Tulsa), plus several radio stations in medium to small markets, on the selling block. On February 25, 2013, Cox announced that it would sell the four television stations, and the LMA for KAME, to Sinclair Broadcast Group; as
|
https://en.wikipedia.org/wiki/ACP%20131
|
ACP-131 is the controlling publication for the listing of and It is published and revised from time to time by the Combined Communications Electronics Board (CCEB) countries: Australia, New Zealand, Canada, United Kingdom, and United States. When the meanings of the codes contained in ACP-131 are translated into various languages, the codes provide a means of communicating between ships of various nations, such as during a NATO exercise, where there is no common language.
History
The original edition of ACP-131 was published by the U.S. military during the early years of radio telegraphy for use by radio operators using Morse Code on continuous wave (CW) telegraphy. It became especially useful, and even essential, to wireless radio operators on both military and civilian ships at sea before the development of advanced single-sideband telephony in the 1960s.
Reason for the codes
Radio communications, prior to the advent of landlines and satellites as communication paths and relays, was always subject to unpredictable fade outs caused by weather conditions, practical limits on available emission power at the transmitter, radio frequency of the transmission, type of emission, type of transmitting antenna, signal waveform characteristics, modulation scheme in use, sensitivity of the receiver and presence, or lack of presence, of atmospheric reflective layers above the earth, such as the E-layer and F-layers, the type of receiving antenna, the time of day, and numerous other factors.
Because of these factors which often resulted in limiting periods of transmission time on certain frequencies to only several hours a day, or only several minutes, it was found necessary to keep each wireless transmission as short as possible and to still get the message through. This was particularly true of CW radio circuits shared by a number of operators, with some waiting their turn to transmit.
As a result, an operator communicating by radio telegraphy to another operator, want
|
https://en.wikipedia.org/wiki/Near-field%20scanning%20optical%20microscope
|
Near-field scanning optical microscopy (NSOM) or scanning near-field optical microscopy (SNOM) is a microscopy technique for nanostructure investigation that breaks the far field resolution limit by exploiting the properties of evanescent waves. In SNOM, the excitation laser light is focused through an aperture with a diameter smaller than the excitation wavelength, resulting in an evanescent field (or near-field) on the far side of the aperture. When the sample is scanned at a small distance below the aperture, the optical resolution of transmitted or reflected light is limited only by the diameter of the aperture. In particular, lateral resolution of 6 nm and vertical resolution of 2–5 nm have been demonstrated.
As in optical microscopy, the contrast mechanism can be easily adapted to study different properties, such as refractive index, chemical structure and local stress. Dynamic properties can also be studied at a sub-wavelength scale using this technique.
NSOM/SNOM is a form of scanning probe microscopy.
History
Edward Hutchinson Synge is given credit for conceiving and developing the idea for an imaging instrument that would image by exciting and collecting diffraction in the near field. His original idea, proposed in 1928, was based upon the usage of intense nearly planar light from an arc under pressure behind a thin, opaque metal film with a small orifice of about 100 nm. The orifice was to remain within 100 nm of the surface, and information was to be collected by point-by-point scanning. He foresaw the illumination and the detector movement being the biggest technical difficulties. John A. O'Keefe also developed similar theories in 1956. He thought the moving of the pinhole or the detector when it is so close to the sample would be the most likely issue that could prevent the realization of such an instrument. It was Ash and Nicholls at University College London who, in 1972, first broke the Abbe’s diffraction limit using microwave radiation with a wa
|
https://en.wikipedia.org/wiki/Analyser
|
An analyser (British English) or analyzer (American English; see spelling differences) is a tool used to analyze data. For example, a gas analyzer tool is used to analyze gases. It examines the given data and tries to find patterns and relationships. An analyser can be a piece of hardware or software.
Autoanalysers are machines that perform their work with little human involvement.
Operation
Analysis can be done directly on samples or the analyser can process data acquired from a remote sensor. The source of samples for automatic sampling is commonly some kind of industrial process. Analysers that are connected to a process and conduct automatic sampling, can be called online (or on-line) analysers or sometimes inline (or in-line) analysers. For inline analysis, a sensor can be placed in a process vessel or stream of flowing material. Another method of online analysis is allowing a sample stream to flow from the process equipment into an analyser, sometimes conditioning the sample stream e.g., by reducing pressure or changing the sample temperature. Many analysers are not designed to withstand high pressure. Such sampling is typically for fluids (either liquids or gases). If the sample stream is not substantially modified by the analyser, it can be returned to the process. Otherwise, the sample stream is discarded; for example, if reagents were added.
Pressure can be lowered by a pressure reducing valve. Such valves may be used to control the flow rate to the online analyser. The temperature of a hot sample may be lowered by use of an online sample cooler. Analysis can be done periodically (for example, every 15 minutes), or continuously. For periodic sampling, valves (or other devices) can be switched open to allow a fluid sample stream to flow to the analyser and shut when not sampling.
Some methods of inline analysis are so simple, such as electrical conductivity or pH, the instruments are usually not even called analysers. Salinity determined from simple onl
|
https://en.wikipedia.org/wiki/Salience%20%28neuroscience%29
|
Salience (also called saliency) is that property by which some thing stands out. Salient events are an attentional mechanism by which organisms learn and survive; those organisms can focus their limited perceptual and cognitive resources on the pertinent (that is, salient) subset of the sensory data available to them.
Saliency typically arises from contrasts between items and their neighborhood. They might be represented, for example, by a red dot surrounded by white dots, or by a flickering message indicator of an answering machine, or a loud noise in an otherwise quiet environment. Saliency detection is often studied in the context of the visual system, but similar mechanisms operate in other sensory systems. Just what is salient can be influenced by training: for example, for human subjects particular letters can become salient by training. There can be a sequence of necessary events, each of which has to be salient, in turn, in order for successful training in the sequence; the alternative is a failure, as in an illustrated sequence when tying a bowline; in the list of illustrations, even the first illustration is a salient: the rope in the list must cross over, and not under the bitter end of the rope (which can remain fixed, and not free to move); failure to notice that the first salient has not been satisfied means the knot will fail to hold, even when the remaining salient events have been satisfied.
When attention deployment is driven by salient stimuli, it is considered to be bottom-up, memory-free, and reactive. Conversely, attention can also be guided by top-down, memory-dependent, or anticipatory mechanisms, such as when looking ahead of moving objects or sideways before crossing streets. Humans and other animals have difficulty paying attention to more than one item simultaneously, so they are faced with the challenge of continuously integrating and prioritizing different bottom-up and top-down influences.
Neuroanatomy
The brain component named the
|
https://en.wikipedia.org/wiki/Spatial%20relation
|
A spatial relation specifies how some object is located in space in relation to some reference object. When the reference object is much bigger than the object to locate, the latter is often represented by a point. The reference object is often represented by a bounding box.
In Anatomy it might be the case that a spatial relation is not fully applicable. Thus, the degree of applicability is defined which specifies from 0 till 100% how strongly a spatial relation holds. Often researchers concentrate on defining the applicability function for various spatial relations.
In spatial databases and geospatial topology the spatial relations are used for spatial analysis and constraint specifications.
In cognitive development for walk and for catch objects, or for understand objects-behaviour; in robotic Natural Features Navigation; and many other areas, spatial relations plays a central role.
Commonly used types of spatial relations are: topological, directional and distance relations.
Topological relations
The DE-9IM model expresses important space relations which are invariant to rotation, translation and scaling transformations.
For any two spatial objects a and b, that can be points, lines and/or polygonal areas, there are 9 relations derived from DE-9IM:
Directional relations
Directional relations can again be differentiated into external directional relations and internal directional relations. An internal directional relation specifies where an object is located inside the reference object while an external relations specifies where the object is located outside of the reference objects.
Examples for internal directional relations: left; on the back; athwart, abaft
Examples for external directional relations: on the right of; behind; in front of, abeam, astern
Distance relations
Distance relations specify how far is the object away from the reference object.
Examples are: at; nearby; in the vicinity; far away
Relations by class
Reference objects repres
|
https://en.wikipedia.org/wiki/Andon%20%28manufacturing%29
|
In manufacturing, andon () is a system which notifies managerial, maintenance, and other workers of a quality or process problem. The alert can be activated manually by a worker using a pullcord or button or may be activated automatically by the production equipment itself. The system may include a means to pause production so the issue can be corrected. Some modern alert systems incorporate audio alarms, text, or other displays; stack lights are among the most commonly used.
“Andon” is a loanword from Japanese, originally meaning paper lantern; Japanese manufacturers began its quality-control usage.
Details
An andon system is one of the principal elements of the Jidoka quality control method pioneered by Toyota as part of the Toyota Production System and therefore now part of the lean production approach.
The principle of Andon works as such: if there are any production issues happening in Production line, the affected work station operator will need to trigger alert by pulling down the andon cord. But since 2014, Toyota is slowly replacing the andon cord with "andon button" as it can be operated wirelessly and reduce the clutter mess of tangling cables in production floor which leads to avoidance of tripping incidents in production floor. It gives workers the ability, and moreover the empowerment, to stop production when a defect is found, and immediately call for assistance. Common reasons for manual activation of the andon are:
Part shortage
Defects created or found
Tools/machines malfunction
Existence of a safety problem.
All work in production line is stopped until a solution has been found. The alerts may be logged to a database so that they can be studied as part of a continual improvement process. Once the problem is troubleshot and fixed, a second pull of the andon cord authorizes the production to be resumed.
The system typically indicates where the alert was generated, and may also provide a description of the issue. Modern andon systems can
|
https://en.wikipedia.org/wiki/Philip%20Hanawalt
|
Philip C. Hanawalt (born 1931) is an American biologist who discovered the process of repair replication of damaged DNA in 1963. He is also considered the co-discoverer of the ubiquitous process of DNA excision repair along with his mentor, Richard Setlow, and Paul Howard-Flanders. He holds the Dr. Morris Herzstein Professorship in the Department of Biology at Stanford University, with a joint appointment in the Dermatology Department in Stanford University School of Medicine.
Early life and education
Philip C. Hanawalt was born on 1931 in Akron, Ohio. He was raised in Midland, Michigan. Having an interest in electronics from youth, Hanawalt earned an honorable mention in the 1949 Westinghouse Science Talent Search, receiving a scholarship to attend Deep Springs College. Hanawalt eventually transferred to Oberlin College where he received his B.A. degree in physics in 1954. He received his M.S. degree in physics from Yale University in 1955. Hanawalt also received his Ph.D. in Biophysics from Yale University in 1959. His doctoral thesis advisor was Richard Setlow.
He undertook three years of postdoctoral study at the University of Copenhagen, Denmark, and at the California Institute of Technology before joining the faculty at Stanford in 1961.
DNA repair
DNA repair is the process by which all living cells deal with damage to their genetic material. Such damage occurs as a consequence of exposure to environmental radiations and genotoxic chemicals, but also to endogenous oxidations and the intrinsic instability of DNA. Hanawalt and his colleagues discovered a special pathway of excision repair, called transcription-coupled repair, which is targeted to expressed genes, and he studies several diseases characterized by defects in DNA repair pathways. DNA repair is important for protecting against cancer and some aspects of ageing in humans, and its deficiency has been implicated in the etiology of a number of hereditary diseases.
Career
In 1965 Hanawalt became ass
|
https://en.wikipedia.org/wiki/Java%20processor
|
A Java processor is the implementation of the Java virtual machine (JVM) in hardware. In other words, the Java bytecode that makes up the instruction set of the abstract machine becomes the instruction set of a concrete machine. These were the most popular form of a high-level language computer architecture, and were "an attractive choice for building embedded and real-time systems that are programmed in Java". However, as of 2017, embedded Java is "pretty much dead" and no realtime Java chip vendors exist.
Implementations
There are several research Java processors tested on FPGA, including:
picoJava was the first attempt to build a Java processor, by Sun Microsystems. Its successor picoJava-II was freely available under the Sun Community Source License, and is still available from some archives.
provides hardware support for object-oriented functions
Java Optimized Processor for FPGAs. A PhD thesis is available, and it has been used in several commercial applications. In 2019 it was extended to be energy aware (EAJOP).
Some commercial implementations included:
The aJile processor was the most successful ASIC Java processor.
Cjip from Imsys Technologies. Available on boards and with wireless radios from AVIDwireless
ARM926EJ-S is an ARM processor able to run Java bytecode, this technology being named Jazelle
See also
Java Card
References
Java virtual machine
High-level language computer architecture
|
https://en.wikipedia.org/wiki/Economic%20capital
|
In finance, mainly for financial services firms, economic capital (ecap) is the amount of risk capital, assessed on a realistic basis, which a firm requires to cover the risks that it is running or collecting as a going concern, such as market risk, credit risk, legal risk, and operational risk. It is the amount of money that is needed to secure survival in a worst-case scenario. Firms and financial services regulators should then aim to hold risk capital of an amount equal at least to economic capital.
Typically, economic capital is calculated by determining the amount of capital that the firm needs to ensure that its realistic balance sheet stays solvent over a certain time period with a pre-specified probability. Therefore, economic capital is often calculated as value at risk. The balance sheet, in this case, would be prepared showing market value (rather than book value) of assets and liabilities.
The first accounts of economic capital date back to the ancient Phoenicians, who took rudimentary tallies of frequency and severity of illnesses among rural farmers to gain an intuition of expected losses in productivity. These calculations were advanced by correlations to climate change, political outbreaks, and birth rate change.
The concept of economic capital differs from regulatory capital in the sense that regulatory capital is the mandatory capital the regulators require to be maintained while economic capital is the best estimate of required capital that financial institutions use internally to manage their own risk and to allocate the cost of maintaining regulatory capital among different units within the organization.
In social science
In social science, economic capital is distinguished in relation to other types of capital which may not necessarily reflect a monetary or exchange-value. These forms of capital include natural capital, cultural capital and social capital; the latter two represent a type of power or status that an individual can attain
|
https://en.wikipedia.org/wiki/Microsoft%20Point-to-Point%20Encryption
|
Microsoft Point-to-Point Encryption (MPPE) encrypts data in Point-to-Point Protocol (PPP)-based dial-up connections or Point-to-Point Tunneling Protocol (PPTP) virtual private network (VPN) connections. 128-bit key (strong), 56-bit key, and 40-bit key (standard) MPPE encryption schemes are supported. MPPE provides data security for the PPTP connection that is between the VPN client and the VPN server.
MPPE alone does not compress or expand data, but the protocol is often used in conjunction with Microsoft Point-to-Point Compression which compresses data across PPP or VPN links.
Negotiation of MPPE happens within the Compression Control Protocol (CCP), a subprotocol of PPP. This can lead to incorrect belief that it is a compression protocol.
RFC 3078, which defines this protocol, defines RC4 with either 40-bit or 128-bit key lengths as the only encryption options with this protocol.
External links
(the protocol), (deriving initial session keys)
MPPE, Microsoft Point-To-Point Encryption Protocol
Broken cryptography algorithms
Cryptographic protocols
Internet protocols
Microsoft Windows security technology
|
https://en.wikipedia.org/wiki/Truncation%20%28geometry%29
|
In geometry, a truncation is an operation in any dimension that cuts polytope vertices, creating a new facet in place of each vertex. The term originates from Kepler's names for the Archimedean solids.
Uniform truncation
In general any polyhedron (or polytope) can also be truncated with a degree of freedom as to how deep the cut is, as shown in Conway polyhedron notation truncation operation.
A special kind of truncation, usually implied, is a uniform truncation, a truncation operator applied to a regular polyhedron (or regular polytope) which creates a resulting uniform polyhedron (uniform polytope) with equal edge lengths. There are no degrees of freedom, and it represents a fixed geometric, just like the regular polyhedra.
In general all single ringed uniform polytopes have a uniform truncation. For example, the icosidodecahedron, represented as Schläfli symbols r{5,3} or , and Coxeter-Dynkin diagram or has a uniform truncation, the truncated icosidodecahedron, represented as tr{5,3} or , . In the Coxeter-Dynkin diagram, the effect of a truncation is to ring all the nodes adjacent to the ringed node.
A uniform truncation performed on the regular triangular tiling {3,6} results in the regular hexagonal tiling {6,3}.
Truncation of polygons
A truncated n-sided polygon will have 2n sides (edges). A regular polygon uniformly truncated will become another regular polygon: t{n} is {2n}. A complete truncation (or rectification), r{3}, is another regular polygon in its dual position.
A regular polygon can also be represented by its Coxeter-Dynkin diagram, , and its uniform truncation , and its complete truncation . The graph represents Coxeter group I2(n), with each node representing a mirror, and the edge representing the angle π/n between the mirrors, and a circle is given around one or both mirrors to show which ones are active.
Star polygons can also be truncated. A truncated pentagram {5/2} will look like a pentagon, but is actually a double-covered (deg
|
https://en.wikipedia.org/wiki/164%20%28number%29
|
164 (one hundred [and] sixty-four) is the natural number following 163 and preceding 165.
In mathematics
164 is a zero of the Mertens function.
In base 10, 164 is the smallest number that can be expressed as a concatenation of two squares in two different ways: as 1 concatenate 64 or 16 concatenate 4.
In astronomy
164P/Christensen is a comet in the Solar System
164 Eva is a large and dark Main belt asteroid
In geography
Chaplin no. 164, Saskatchewan in Saskatchewan, Canada
In the military
was a cargo vessel during World War II
was a T2 tanker during World War II
was a Barracuda-class submarine during World War II
was an Alamosa-class cargo ship during World War II
was an Admirable-class minesweeper during World War II
was a Trefoil-class concrete barge during World War II
was a during World War II
was a during World War II
was a yacht during World War I
was a during World War II
In sports
Baseball Talk was a set of 164 talking baseball cards released by Topps Baseball Card Company in 1989
In transportation
Caproni Ca.164 was a training biplane produced in Italy prior to World War II
The Alfa Romeo 164 car produced from 1988 to 1997
The Volvo 164 car produced from 1968 to 1975
List of highways numbered 164
Is a London Transport bus route running between Sutton and Wimbledon
In other fields
164 is also:
The year AD 164 or 164 BC
164 AH is a year in the Islamic calendar that corresponds to 780 – 781 CE
The Scrabble board, a 15-by-15 grid, includes 164 squares that have neither word nor letter multiplier. The remainder have attributes such as double letter, triple letter, double word, and triple word
The atomic number of an element temporarily called Unhexquadium
Solvent Red 164 is a synthetic red diazo dye
E.164 is an ITU-T recommendation defines public telecommunication numbering plan used in the PSTN and data networks
See also
United States Supreme Court cases, Volume 164
United Nations Security Council Resolution 164
|
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.