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Topic Review
Privacy Concerns with Facebook
Meta Platforms Inc., or Meta for short, (formerly known as Facebook) has faced a number of privacy concerns. These stem partly from the company’s revenue model that involves selling information collected about its users for many things including advertisement targeting. Meta Platforms Inc. has also been a part of many data breaches that have occurred within the company. These issues and others are further described including user data concerns, vulnerabilities in the company’s platform, investigations by pressure groups and government agencies, and even issues with students. In addition, employers and other organizations/individuals have been known to use Meta Platforms Inc. for their own purposes. As a result, individuals’ identities and private information have sometimes been compromised without their permission. In response to these growing privacy concerns, some pressure groups and government agencies have increasingly asserted the users’ right to privacy and to be able to control their personal data.
  • 2.5K
  • 19 Oct 2022
Topic Review
Energy Condition
In relativistic classical field theories of gravitation, particularly general relativity, an energy condition is a generalization of the statement "the energy density of a region of space cannot be negative" in a relativistically-phrased mathematical formulation. There are multiple possible alternative ways to express such a condition such that can be applied to the matter content of the theory. The hope is then that any reasonable matter theory will satisfy this condition or at least will preserve the condition if it is satisfied by the starting conditions. Energy conditions are not physical constraints per se, but are rather mathematically imposed boundary conditions that attempt to capture a belief that "energy should be positive". Many energy conditions are known to not correspond to physical reality—for example, the observable effects of dark energy are well-known to violate the strong energy condition. In general relativity, energy conditions are often used (and required) in proofs of various important theorems about black holes, such as the no hair theorem or the laws of black hole thermodynamics.
  • 2.5K
  • 07 Nov 2022
Topic Review
Well-Known Text
Well-known text (WKT) is a text markup language for representing vector geometry objects on a map, spatial reference systems of spatial objects and transformations between spatial reference systems. A binary equivalent, known as well-known binary (WKB), is used to transfer and store the same information on databases. The formats were originally defined by the Open Geospatial Consortium (OGC) and described in their Simple Feature Access and Coordinate Transformation Service specifications. The current standard definition is in the ISO/IEC 13249-3:2016 standard, "Information technology – Database languages – SQL multimedia and application packages – Part 3: Spatial" (SQL/MM) and ISO 19162:2015, "Geographic information – Well-known text representation of coordinate reference systems".
  • 2.5K
  • 27 Oct 2022
Topic Review
Gambling Mathematics
The mathematics of gambling are a collection of probability applications encountered in games of chance and can be included in game theory. From a mathematical point of view, the games of chance are experiments generating various types of aleatory events, the probability of which can be calculated by using the properties of probability on a finite space of events.
  • 2.5K
  • 25 Oct 2022
Topic Review
Optical Camera Communication
Visible Light Communication (VLC) uses various properties of light to encode digital data, which is then modulated and transmitted over a short distance to the receiver. Photodiodes are inexpensive and provide low complexity implementation,  but their adoption requires modifying existing devices to house dedicated sensors. On the other hand, in Optical Camera Communication (OCC), existing camera-based receivers are used to extract encoded data using properties of light like color, blink frequency, intensity, and polarity. Thus, OCC is considered one possible solution to achieve a ready-to-use VLC system by utilizing the camera’s properties, computational capacity of mobile phones, and chromaticity of the light. 
  • 2.4K
  • 12 Jul 2022
Topic Review
WordNet
WordNet is a lexical database of semantic relations between words in more than 200 languages. WordNet links words into semantic relations including synonyms, hyponyms, and meronyms. The synonyms are grouped into synsets with short definitions and usage examples. WordNet can thus be seen as a combination and extension of a dictionary and thesaurus. While it is accessible to human users via a web browser, its primary use is in automatic text analysis and artificial intelligence applications. WordNet was first created in the English language and the English WordNet database and software tools have been released under a BSD style license and are freely available for download from that WordNet website.
  • 2.4K
  • 11 Nov 2022
Topic Review
Insect Euthanasia
Insect euthanasia is the process of killing insects "in a way that minimizes or eliminates pain and distress.":6 It may apply to animals in the laboratory, schools, as pets, as food, or otherwise. Euthanasia of insects and other invertebrates has historically received limited attention.:75 While vertebrate animal experimentation typically requires approval by an Institutional Animal Care and Use Committee in the United States, use of invertebrate animals has few guidelines, and many research papers make no mention of how their invertebrate subjects were killed. Many of the euthanasia methods developed for vertebrates do not transfer well to invertebrates. While a number of euthanasia methods have been proposed for various invertebrate taxa, many have not been adequately vetted, and more research is needed.
  • 2.4K
  • 17 Nov 2022
Topic Review
Mo Siang Online
Mo Siang Online is an MMORPG based on the warring states of ancient China . The game is mainly focused on Martial Arts and Kung Fu, allowing each character to choose 6 fighting styles. At present, Mo Siang only has five English servers and eight Chinese servers with their own language interface.The Korean game developer once released its global server and renamed this game as Titan, but this game used to be called as Dark Story in Korea with its Korean server. In Japan, Mo Siang is called Feats of Arms. After the agent in Japan is replaced, this game is renamed as Crest of Jade. The Japanese game distributor run its Beta on 19th Feb. 2009. From August 2009 on, there is another English version of Mo Siang released, the game agent PlayOMG renames this game as Azuga, Age of Chaos. On the contrary, from September 2009 on, the Japanese game agent of Mo Siang decides to close their server.
  • 2.4K
  • 22 Nov 2022
Topic Review
French Republican Calendar
The French Republican calendar (French: calendrier républicain français), also commonly called the French Revolutionary calendar (calendrier révolutionnaire français), was a calendar created and implemented during the French Revolution , and used by the French government for about 12 years from late 1793 to 1805, and for 18 days by the Paris Commune in 1871. The revolutionary system was designed in part to remove all religious and royalist influences from the calendar, and was part of a larger attempt at decimalisation in France (which also included decimal time of day, decimalisation of currency, and metrication). It was used in government records in France and other areas under French rule, including Belgium, Luxembourg, and parts of the Netherlands, Germany, Switzerland, Malta, and Italy.
  • 2.3K
  • 19 Oct 2022
Topic Review
VC Dimension
In Vapnik–Chervonenkis theory, the VC dimension (for Vapnik–Chervonenkis dimension) is a measure of the capacity (complexity, expressive power, richness, or flexibility) of a space of functions that can be learned by a statistical classification algorithm. It is defined as the cardinality of the largest set of points that the algorithm can shatter. It was originally defined by Vladimir Vapnik and Alexey Chervonenkis. Formally, the capacity of a classification model is related to how complicated it can be. For example, consider the thresholding of a high-degree polynomial: if the polynomial evaluates above zero, that point is classified as positive, otherwise as negative. A high-degree polynomial can be wiggly, so it can fit a given set of training points well. But one can expect that the classifier will make errors on other points, because it is too wiggly. Such a polynomial has a high capacity. A much simpler alternative is to threshold a linear function. This function may not fit the training set well, because it has a low capacity. This notion of capacity is made rigorous below.
  • 2.3K
  • 04 Nov 2022
Topic Review
RdRand
RDRAND (previously known as Bull Mountain) is an instruction for returning random numbers from an Intel on-chip hardware random number generator which has been seeded by an on-chip entropy source. RDRAND is available in Ivy Bridge processors[lower-alpha 1] and is part of the Intel 64 and IA-32 instruction set architectures. AMD added support for the instruction in June 2015. The random number generator is compliant with security and cryptographic standards such as NIST SP 800-90A, FIPS 140-2, and ANSI X9.82. Intel also requested Cryptography Research Inc. to review the random number generator in 2012, which resulted in the paper Analysis of Intel's Ivy Bridge Digital Random Number Generator. RDSEED is similar to RDRAND and provides higher level access to the entropy hardware. The RDSEED generator and processor instruction rdseed are available with Intel Broadwell CPUs and AMD Zen CPUs.
  • 2.3K
  • 09 Nov 2022
Topic Review
Georg Cantor's First Set Theory Article
Georg Cantor published his first set theory article in 1874, and it contains the first theorems of transfinite set theory, which studies infinite sets and their properties. One of these theorems is "Cantor's revolutionary discovery" that the set of all real numbers is uncountably, rather than countably, infinite. This theorem is proved using Cantor's first uncountability proof, which differs from the more familiar proof using his diagonal argument. The title of the article, "On a Property of the Collection of All Real Algebraic Numbers" ("Ueber eine Eigenschaft des Inbegriffes aller reellen algebraischen Zahlen"), refers to its first theorem: the set of real algebraic numbers is countable. Cantor's article also contains a proof of the existence of transcendental numbers. As early as 1930, mathematicians have disagreed on whether this proof is constructive or non-constructive. Books as recent as 2014 and 2015 indicate that this disagreement has not been resolved. Since Cantor's proof either constructs transcendental numbers or does not, an analysis of his article can determine whether his proof is constructive or non-constructive. Cantor's correspondence with Richard Dedekind shows the development of his ideas and reveals that he had a choice between two proofs, one that uses the uncountability of the real numbers and one that does not. Historians of mathematics have examined Cantor's article and the circumstances in which it was written. For example, they have discovered that Cantor was advised to leave out his uncountability theorem in the article he submitted; he added it during proofreading. They have traced this and other facts about the article to the influence of Karl Weierstrass and Leopold Kronecker. Historians have also studied Dedekind's contributions to the article, including his contributions to the theorem on the countability of the real algebraic numbers. In addition, they have looked at the article's legacy, which includes the impact that the uncountability theorem and the concept of countability have had on mathematics.
  • 2.3K
  • 02 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.
  • 2.3K
  • 08 Oct 2022
Topic Review
WannaCry Ransomware Attack
The WannaCry ransomware attack was a worldwide cyberattack in May 2017 by the WannaCry ransomware cryptoworm, which targeted computers running the Microsoft Windows operating system by encrypting data and demanding ransom payments in the Bitcoin cryptocurrency. It propagated through EternalBlue, an exploit developed by the United States National Security Agency (NSA) for older Windows systems. EternalBlue was stolen and leaked by a group called The Shadow Brokers a month prior to the attack. While Microsoft had released patches previously to close the exploit, much of WannaCry's spread was from organizations that had not applied these, or were using older Windows systems that were past their end-of-life. These patches were imperative to organizations' cyber security but many were not implemented due to ignorance of their importance. Some have claimed a need for 24/7 operation, aversion to risking having formerly working applications breaking because of patch changes, lack of personnel or time to install them, or other reasons. The attack began at 07:44 UTC on 12 May 2017 and was halted a few hours later at 15:03 UTC by the registration of a kill switch discovered by Marcus Hutchins. The kill switch prevented already infected computers from being encrypted or further spreading WannaCry. The attack was estimated to have affected more than 200,000 computers across 150 countries, with total damages ranging from hundreds of millions to billions of United States dollar . Security experts believed from preliminary evaluation of the worm that the attack originated from North Korea or agencies working for the country. In December 2017, the United States and United Kingdom formally asserted that North Korea was behind the attack. A new variant of WannaCry forced Taiwan Semiconductor Manufacturing Company (TSMC) to temporarily shut down several of its chip-fabrication factories in August 2018. The virus spread to 10,000 machines in TSMC's most advanced facilities.
  • 2.3K
  • 14 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.
  • 2.3K
  • 28 Nov 2022
Topic Review
Crossword
A crossword is a word puzzle and word search game that usually takes the form of a square or a rectangular grid of white- and black-shaded squares. The game's goal is to fill the white squares with letters, forming words or phrases, by solving clues, which lead to the answers. In languages that are written left-to-right, the answer words and phrases are placed in the grid from left to right and from top to bottom. The shaded squares are used to separate the words or phrases.
  • 2.3K
  • 10 Nov 2022
Topic Review
Pencil (Mathematics)
In geometry, a pencil is a family of geometric objects with a common property, for example the set of lines that pass through a given point in a plane, or the set of circles that pass through two given points in a plane. Although the definition of a pencil is rather vague, the common characteristic is that the pencil is completely determined by any two of its members. Analogously, a set of geometric objects that are determined by any three of its members is called a bundle. Thus, the set of all lines through a point in three-space is a bundle of lines, any two of which determine a pencil of lines. To emphasize the two dimensional nature of such a pencil, it is sometimes referred to as a flat pencil Any geometric object can be used in a pencil. The common ones are lines, planes, circles, conics, spheres and general curves. Even points can be used. A pencil of points is the set of all points on a given line. A more common term for this set is a range of points.
  • 2.3K
  • 10 Oct 2022
Topic Review
Italian Fiscal Code Card
The Italian fiscal code card, officially known as Italy's Codice fiscale, is the tax code card in Italy, similar to a Social Security Number (SSN) card in the United States or the National Insurance Number issued in the United Kingdom. The tax code in Italy is an alphanumeric code of 16 characters. The card serves to identify unambiguously individuals residing in Italy irrespective of residency status. Designed by and for the Italian tax office, it is now used for several other purposes, e.g. uniquely identifying individuals in the health system, or natural persons who act as parties in private contracts. The number is issued by the Italian tax office. Each person in the past was handed a plastic card with a magnetic strip, bearing the tax code as well as the surname, given name(s), sex, place and province of birth (or country of birth if foreign), date of birth and date of issue. Today, the tax or fiscal code card has been replaced by a combined Italian health insurance card for qualifying residents which shows an expiration date.
  • 2.2K
  • 03 Nov 2022
Topic Review
Reason
Reason is a digital audio workstation for creating and editing music and audio developed by Swedish software company Reason Studios (formerly known as Propellerhead Software). Reason emulates a rack of hardware synthesizers, samplers, signal processors, sequencers, and mixers, all of which can be freely interconnected in an arbitrary manner. Reason can be used either as a complete virtual music studio or as a set of virtual instruments to be used with other sequencing software in a fashion that mimics live performance.
  • 2.2K
  • 30 Sep 2022
Topic Review
Chi-Square Distribution
In probability theory and statistics, the chi-square distribution (also chi-squared or χ2-distribution) with k degrees of freedom is the distribution of a sum of the squares of k independent standard normal random variables. The chi-square distribution is a special case of the gamma distribution and is one of the most widely used probability distributions in inferential statistics, notably in hypothesis testing and in construction of confidence intervals. This distribution is sometimes called the central chi-square distribution, a special case of the more general noncentral chi-square distribution. The chi-square distribution is used in the common chi-square tests for goodness of fit of an observed distribution to a theoretical one, the independence of two criteria of classification of qualitative data, and in confidence interval estimation for a population standard deviation of a normal distribution from a sample standard deviation. Many other statistical tests also use this distribution, such as Friedman's analysis of variance by ranks.
  • 2.2K
  • 11 Nov 2022
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