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Topic Review
Turn (Geometry)
A turn is a unit of plane angle measurement equal to 2π radians, 360 degrees or 400 gradians. A turn is also referred to as a cycle (abbreviated cyc), revolution (abbreviated rev), complete rotation (abbreviated rot) or full circle. Subdivisions of a turn include half turns, quarter turns, centiturns, milliturns, points, etc.
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  • 22 Nov 2022
Topic Review
IBM Hexadecimal Floating Point
IBM System/360 computers, and subsequent machines based on that architecture (mainframes), support a hexadecimal floating-point format (HFP). In comparison to IEEE 754 floating-point, the IBM floating-point format has a longer significand, and a shorter exponent. All IBM floating-point formats have 7 bits of exponent with a bias of 64. The normalized range of representable numbers is from 16−65 to 1663 (approx. 5.39761 × 10−79 to 7.237005 × 1075). The number is represented as the following formula: (−1)sign × 0.significand × 16exponent−64.
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  • 09 Oct 2022
Topic Review
Signalling (Economics)
In contract theory, signalling (or signaling; see spelling differences) is the idea that one party (the agent) credibly conveys some information about itself to another party (the principal). Although signalling theory was initially developed by Michael Spence based on observed knowledge gaps between organisations and prospective employees, its intuitive nature led it to be adapted to many other domains, such as Human Resource Management, business, and financial markets. In Spence's job-market signaling model, (potential) employees send a signal about their ability level to the employer by acquiring education credentials. The informational value of the credential comes from the fact that the employer believes the credential is positively correlated with having the greater ability and difficulty for low ability employees to obtain. Thus the credential enables the employer to reliably distinguish low ability workers from high ability workers. The concept of signaling is also applicable in competitive altruistic interaction, where the capacity of the receiving party is limited.
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  • 21 Nov 2022
Topic Review
Lemniscatic Elliptic Function
In mathematics, a lemniscatic elliptic function is an elliptic function related to the arc length of a lemniscate of Bernoulli studied by Giulio Carlo de' Toschi di Fagnano in 1718. It has a square period lattice and is closely related to the Weierstrass elliptic function when the Weierstrass invariants satisfy g2 = 1 and g3 = 0. In the lemniscatic case, the minimal half period ω1 is real and equal to where Γ is the gamma function. The second smallest half period is pure imaginary and equal to iω1. In more algebraic terms, the period lattice is a real multiple of the Gaussian integers. The constants e1, e2, and e3 are given by The case g2 = a, g3 = 0 may be handled by a scaling transformation. However, this may involve complex numbers. If it is desired to remain within real numbers, there are two cases to consider: a > 0 and a < 0. The period parallelogram is either a square or a rhombus.
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  • 24 Oct 2022
Topic Review
List of Notable Security Hacking Incidents
The timeline of computer security hacker history covers important and noteworthy events in the history of security hacking and cracking.
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  • 25 Oct 2022
Topic Review
Strategy (Game Theory)
In game theory, a player's strategy is any of the options which they choose in a setting where the outcome depends not only on their own actions but on the actions of others. The discipline mainly concerns the action of a player in a game affecting the behavior or actions of other players. Some examples of "games" include chess, bridge, poker, monopoly, diplomacy or battleship. A player's strategy will determine the action which the player will take at any stage of the game. In studying game theory, economists enlist a more rational lens in analyzing decisions rather than the psychological or sociological perspectives taken when analyzing relationships between decisions of two or more parties in different disciplines. The strategy concept is sometimes (wrongly) confused with that of a move. A move is an action taken by a player at some point during the play of a game (e.g., in chess, moving white's Bishop a2 to b3). A strategy on the other hand is a complete algorithm for playing the game, telling a player what to do for every possible situation throughout the game. It is helpful to think about a "strategy" as a list of directions, and a "move" as a single turn on the list of directions itself. This strategy is based on the payoff or outcome of each action. The goal of each agent is to consider their payoff based on a competitors action. For example, competitor A can assume competitor B enters the market. From there, Competitor A compares the payoffs they receive by entering and not entering. The next step is to assume Competitor B doesn't enter and then consider which payoff is better based on if Competitor A chooses to enter or not enter. This technique can identify dominant strategies where a player can identify an action that they can take no matter what the competitor does to try and maximize the payoff. This also helps players to identify Nash equilibrium which are discussed in more detail below. A strategy profile (sometimes called a strategy combination) is a set of strategies for all players which fully specifies all actions in a game. A strategy profile must include one and only one strategy for every player.
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  • 28 Nov 2022
Topic Review
Bit Manipulation Instruction Sets
Bit Manipulation Instructions Sets (BMI sets) are extensions to the x86 instruction set architecture for microprocessors from Intel and AMD. The purpose of these instruction sets is to improve the speed of bit manipulation. All the instructions in these sets are non-SIMD and operate only on general-purpose registers. There are two sets published by Intel: BMI (here referred to as BMI1) and BMI2; they were both introduced with the Haswell microarchitecture. Another two sets were published by AMD: ABM (Advanced Bit Manipulation, which is also a subset of SSE4a implemented by Intel as part of SSE4.2 and BMI1), and TBM (Trailing Bit Manipulation, an extension introduced with Piledriver-based processors as an extension to BMI1, but dropped again in Zen-based processors).
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  • 17 Oct 2022
Topic Review
Finale
Finale is the flagship program of a series of proprietary music notation software developed and released by MakeMusic for the Microsoft Windows and macOS operating systems. First released in 1988, version 26 was released in 2018. Finale has been regarded as one of the industry standards for music notation software. Finale is one of a number of types of software used by composers, songwriters and arrangers for creating sheet music, including the score for an entire ensemble (e.g., orchestra, concert band, big band, etc.) and parts for the individual musicians. A scorewriter is to music notation what a word processor is to text, in that they both allow fast corrections (via the "undo" button), flexible editing, easy sharing of content (via the Internet or compact storage media), and production of a clean, uniform layout. In addition, most scorewriters, including Finale, are able to use software-based synthesizers to "play" the sounds of the notated music and record the music—an especially useful feature for novice composers, when no musicians are readily available, or if a composer cannot afford to hire musicians. MakeMusic also offers several less expensive versions of Finale (currently available for Microsoft Windows only), which do not contain all of the main program's features. These include PrintMusic and a freeware program, Finale Notepad, which allows only rudimentary editing. Discontinued versions include Finale Guitar, Notepad Plus, Allegro, SongWriter, and the free Finale Reader.
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  • 04 Nov 2022
Topic Review
Core (Game Theory)
In cooperative game theory, the core is the set of feasible allocations that cannot be improved upon by a subset (a coalition) of the economy's agents. A coalition is said to improve upon or block a feasible allocation if the members of that coalition are better off under another feasible allocation that is identical to the first except that every member of the coalition has a different consumption bundle that is part of an aggregate consumption bundle that can be constructed from publicly available technology and the initial endowments of each consumer in the coalition. An allocation is said to have the core property if there is no coalition that can improve upon it. The core is the set of all feasible allocations with the core property.
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  • 08 Oct 2022
Topic Review
Forensic Toxicology
Forensic toxicology is the use of toxicology and disciplines such as analytical chemistry, pharmacology and clinical chemistry to aid medical or legal investigation of death, poisoning, and drug use. The primary concern for forensic toxicology is not the legal outcome of the toxicological investigation or the technology utilized, but rather the obtainment and interpretation of results. A toxicological analysis can be done to various kinds of samples. A forensic toxicologist must consider the context of an investigation, in particular any physical symptoms recorded, and any evidence collected at a crime scene that may narrow the search, such as pill bottles, powders, trace residue, and any available chemicals. Provided with this information and samples with which to work, the forensic toxicologist must determine which toxic substances are present, in what concentrations, and the probable effect of those chemicals on the person. In the United States, forensic toxicology can be separated into 3 disciplines: Postmortem toxicology, human performance toxicology, and forensic drug testing (FDT). Postmortem toxicology includes the analysis of biological specimens taken from an autopsy to identify the effect of drugs, alcohol, and poisons. A wide range of biological specimens may be analyzed including blood, urine, gastric contents, oral fluids, hair, tissues, and more. The forensic toxicologist works with pathologists, medical examiners, and coroners to help determine the cause and manner of death. In human performance toxicology, a dose-response relationship between a drug(s) present in the body and the effects on the body are examined. This field of forensic toxicology is responsible for building and implementing laws such as driving under the influence of alcohol or drugs. Lastly, forensic drug testing (FDT) is the detection of drug use among individuals in the workplace, sport doping, drug-related probation, and new job applicant screenings. Determining the substance ingested is often complicated by the body's natural processes (see ADME), as it is rare for a chemical to remain in its original form once in the body. For example: heroin is almost immediately metabolised into another substance and further to morphine, making detailed investigation into factors such as injection marks and chemical purity necessary to confirm diagnosis. The substance may also have been diluted by its dispersal through the body; while a pill or other regulated dose of a drug may have grams or milligrams of the active constituent, an individual sample under investigation may only contain micrograms or nanograms.
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  • 09 Nov 2022
Topic Review
Outlier Detection
Outlier detection is a statistical procedure that aims to find suspicious events or items that are different from the normal form of a dataset. It has drawn considerable interest in the field of data mining and machine learning. Outlier detection is important in many applications, including fraud detection in credit card transactions and network intrusion detection. There are two general types of outlier detection: global and local. Global outliers fall outside the normal range for an entire dataset, whereas local outliers may fall within the normal range for the entire dataset, but outside the normal range for the surrounding data points. 
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  • 07 Feb 2021
Topic Review
Literature
This is a list of encyclopedias as well as encyclopedic and biographical dictionaries published on the subject of literature in any language.
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  • 28 Apr 2023
Topic Review
Multivariate Mutual Information
In information theory there have been various attempts over the years to extend the definition of mutual information to more than two random variables. The expression and study of multivariate higher-degree mutual-information was achieved in two seemingly independent works: McGill (1954) who called these functions “interaction information”, and Hu Kuo Ting (1962) who also first proved the possible negativity of mutual-information for degrees higher than 2 and justified algebraically the intuitive correspondence to Venn diagrams .
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  • 18 Oct 2022
Topic Review
Sierpinski Number
In number theory, a Sierpiński number is an odd natural number k such that [math]\displaystyle{ k \times 2^n + 1 }[/math] is composite for all natural numbers n. In 1960, Wacław Sierpiński proved that there are infinitely many odd integers k which have this property. In other words, when k is a Sierpiński number, all members of the following set are composite: If the form is instead [math]\displaystyle{ k \times 2^n - 1 }[/math], then k is a Riesel number.
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  • 02 Dec 2022
Topic Review
Nine-Point Circle
In geometry, the nine-point circle is a circle that can be constructed for any given triangle. It is so named because it passes through nine significant concyclic points defined from the triangle. These nine points are: The nine-point circle is also known as Feuerbach's circle, Euler's circle, Terquem's circle, the six-points circle, the twelve-points circle, the n-point circle, the medioscribed circle, the mid circle or the circum-midcircle. Its center is the nine-point center of the triangle.
  • 3.0K
  • 19 Oct 2022
Topic Review
Bayonetta
Bayonetta is an action hack and slash video game developed by PlatinumGames and published by Sega. The game was originally released for Xbox 360 and PlayStation 3 in Japan in October 2009, and in North America and Europe in January 2010. The game was later released on the Wii U alongside its sequel, Bayonetta 2, releasing in September 2014 in Japan and worldwide the following month - the two games were later released worldwide on the Nintendo Switch in February 2018. An enhanced port for Windows was released in April 2017 with 4K support. A remastered version of Bayonetta as well as another PlatinumGames title, Vanquish, was released for PlayStation 4 and Xbox One on February 18, 2020, as part of a compilation to celebrate the 10th anniversary of the game. Bayonetta takes place in Vigrid, a fictional city in Europe. The game stars the eponymous character, a witch who is capable of shapeshifting and using various firearms. She possesses magical attacks, and she can use her hair to summon demons to dispatch her foes. It features a rating system, which gives players a grade based on their performance, and a combat system that is similar to the Devil May Cry series. Development of the game was started in January 2007, with Hideki Kamiya being the game's director. According to Kamiya, the game was completely original, though he drew some inspirations from Scandinavian mythology, and played Devil May Cry 4 for reference. The game's theme is "sexiness" and "partial nudity", and that the characters were designed to be "fashionable". Kamiya and artist Mari Shimazaki spent more than a year to create Bayonetta's design. Several demos were released for the game prior to its launch. Bayonetta was the third project released by PlatinumGames, which was founded by former Clover Studio employees. Upon release, the game received generally positive reviews. The game was praised for its combat, presentation and soundtrack, but drew criticism for its story and quick time events. Bayonetta was nominated for and won several end-of-the-year accolades, and had sold over a million units worldwide by 2010. An anime film adaptation of the game by Gonzo, titled Bayonetta: Bloody Fate, was released in Japan in November 2013. A third game, Bayonetta 3, is in development for the Switch.
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  • 22 Nov 2022
Topic Review
DNS Tunnelling Detection
The Domain Name System (DNS) protocol is fundamental to the operation of the Internet with the primary purpose of translating domain names to IP addresses. This important service facilitates access to the Internet by using website names or any arbitrary domain names. The DNS protocol communicates internal requests to external remote servers and creates a landscape for attackers to perform malicious activities such as stealing credentials and sensitive data. One of the most effective DNS attack types is DNS tunnelling, where the attacker creates a tunnel between the client’s network and the attacker’s machine, utilising command and control channels to obscure data and bypass the firewall and intrusion detection systems.
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  • 01 Mar 2024
Topic Review
Knowledge Graph
The Google Knowledge Graph is a knowledge base used by Google and its services to enhance its search engine's results with information gathered from a variety of sources. The information is presented to users in an infobox next to the search results. Knowledge Graph infoboxes were added to Google's search engine in May 2012, starting in the United States, with international expansion by the end of the year. The information covered by Google's Knowledge Graph grew quickly after launch, tripling its size within seven months (covering 570 million entities and 18 billion facts) and answering "roughly one-third" of the 100 billion monthly searches Google processed in May 2016. It has been criticized for providing answers without source attribution or citation. Information from the Knowledge Graph is presented as a box, which Google has referred to as the "knowledge panel", to the right (top on mobile) of search results. According to Google, this information is retrieved from many sources, including the CIA World Factbook, Wikidata, and Wikipedia. In October 2016, Google announced that the Knowledge Graph held over 70 billion facts; by May 2020, this had grown to 500 billion facts on 5 billion entities. There is no official documentation of how the Knowledge Graph is implemented. It is used to answer direct spoken questions in Google Assistant and Google Home voice queries.
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  • 02 Dec 2022
Topic Review
Topology of Uniform Convergence
In mathematics, a linear map is a mapping V → W between two modules (including vector spaces) that preserves the operations of addition and scalar multiplication. By studying the linear maps between two modules one can gain insight into their structures. If the modules have additional structure, like topologies or bornologies, then one can study the subspace of linear maps that preserve this structure.
  • 3.0K
  • 28 Nov 2022
Topic Review
A discrete quantum momentum operator
We introduce finite-differences derivatives intended to be exact when applied to the real exponential function. We want to recover the known results of continuous calculus with our finite differences derivatives but in a discrete form. The purpose of this work is to have a discrete momentum operator suitable for use as an operator in discrete quantum mechanics theory.
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  • 24 Aug 2021
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