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Topic Review
Blockchain and Machine Learning for Future Smart Grids
A wide range of solutions, beyond the classical one of building more lines, cables and transformers, have been proposed to modernize the power grid with new technologies, enabling a more smart automatic networked system. These solutions, typically using new technology, go by the name “smart grids” (SG) or “smart-grid technology”. Blockchain technology (BC) is a viable solution to overcome the issues of centralized system. BC is an immutable, distributed and P2P network that provides security, privacy and trust among peers using cryptographic techniques. Machine learning (ML) techniques can be exploited to develop energy prediction algorithms and the proper scheduling of energy usage. A large amount of the energy consumption data of several users is generated from smart meters that also contain users’ private/confidential information as well as sensitive information of utility providers. This high volume of data increases the complexity of data analysis. 
  • 5.1K
  • 27 Feb 2023
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.
  • 5.1K
  • 11 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.
  • 5.1K
  • 10 Nov 2022
Topic Review
Terrestrial Links Rain Attenuation Models
 Rain is a natural process that attenuates the propagating signal at microwave and millimeter-wave frequencies. Therefore, it is necessary to mitigate rain attenuation to ensure the quality of microwave and millimeter-wave links. To this end, dynamic attenuation mitigation methods are implemented alongside attenuation prediction models that can predict the projected attenuation of the links. Studies on rain attenuation are used in geographically distributed locations to analyze and develop a rain attenuation model applicable over a wide frequency range, particularly radio frequencies over approximately 30 GHz for 5G and beyond network applications.
  • 5.1K
  • 02 Jun 2021
Topic Review
Adaptive Clustering
The paper is devoted to an overview of multi-agent principles, methods, and technologies intended to adaptive real-time data clustering. The proposed methods provide new principles of self-organization of records and clusters, represented by software agents, making it possible to increase the adaptability of different clustering processes significantly. The paper also presents a comparative review of the methods and results recently developed in this area and their industrial applications. An ability of self-organization of items and clusters suggests a new perspective to form groups in a bottom-up online fashion together with continuous adaption previously obtained decisions. Multi-agent technology allows implementing this methodology in a parallel and asynchronous multi-thread manner, providing highly flexible, scalable, and reliable solutions. Industrial applications of the intended for solving too complex engineering problems are discussed together with several practical examples of data clustering in manufacturing applications, such as the pre-analysis of customer datasets in the sales process, pattern discovery, and ongoing forecasting and consolidation of orders and resources in logistics, clustering semantic networks in insurance document processing. Future research is outlined in the areas such as capturing the semantics of problem domains and guided self-organization on the virtual market.
  • 5.1K
  • 08 Feb 2021
Topic Review
Altitude (Triangle)
In geometry, an altitude of a triangle is a line segment through a vertex and perpendicular to (i.e., forming a right angle with) a line containing the base (the side opposite the vertex). This line containing the opposite side is called the extended base of the altitude. The intersection of the extended base and the altitude is called the foot of the altitude. The length of the altitude, often simply called "the altitude", is the distance between the extended base and the vertex. The process of drawing the altitude from the vertex to the foot is known as dropping the altitude at that vertex. It is a special case of orthogonal projection. Altitudes can be used in the computation of the area of a triangle: one half of the product of an altitude's length and its base's length equals the triangle's area. Thus, the longest altitude is perpendicular to the shortest side of the triangle. The altitudes are also related to the sides of the triangle through the trigonometric functions. In an isosceles triangle (a triangle with two congruent sides), the altitude having the incongruent side as its base will have the midpoint of that side as its foot. Also the altitude having the incongruent side as its base will be the angle bisector of the vertex angle. It is common to mark the altitude with the letter h (as in height), often subscripted with the name of the side the altitude is drawn to. In a right triangle, the altitude drawn to the hypotenuse c divides the hypotenuse into two segments of lengths p and q. If we denote the length of the altitude by hc, we then have the relation For acute and right triangles the feet of the altitudes all fall on the triangle's sides (not extended). In an obtuse triangle (one with an obtuse angle), the foot of the altitude to the obtuse-angled vertex falls in the interior of the opposite side, but the feet of the altitudes to the acute-angled vertices fall on the opposite extended side, exterior to the triangle. This is illustrated in the adjacent diagram: in this obtuse triangle, an altitude dropped perpendicularly from the top vertex, which has an acute angle, intersects the extended horizontal side outside the triangle.
  • 5.0K
  • 25 Oct 2022
Topic Review
Closed Graph
In mathematics, particularly in functional analysis and topology, closed graph is a property of functions. A function f : X → Y between topological spaces has a closed graph if its graph is a closed subset of the product space X × Y. A related property is open graph. This property is studied because there are many theorems, known as closed graph theorems, giving conditions under which a function with a closed graph is necessarily continuous. One particularly well-known class of closed graph theorems are the closed graph theorems in functional analysis.
  • 5.0K
  • 18 Oct 2022
Topic Review
Power Architecture
Power Architecture is a registered trademark for similar reduced instruction set computing (RISC) instruction sets for microprocessors developed and manufactured by such companies as IBM, Freescale/NXP, AppliedMicro, LSI, Teledyne e2v and Synopsys. The governing body is Power.org, comprising over 40 companies and organizations. "Power Architecture" is a broad term including all products based on newer POWER, PowerPC and Cell processors. The term "Power Architecture" should not be confused with IBM's different generations of "POWER Instruction Set Architecture", an earlier instruction set for IBM RISC processors of the 1990s from which the PowerPC instruction set was derived. Power Architecture is a family name describing processor architecture, software, toolchain, community and end-user appliances and not a strict term describing specific products or technologies. More details and documentation on the Power Architecture can be found on the IBM Portal for OpenPOWER.
  • 5.0K
  • 18 Nov 2022
Topic Review
List of Dell PowerEdge Servers
Dell PowerEdge is a server line by Dell, following the naming convention for other Dell products: the PowerVault (data storage) and the PowerConnect (data transfer & switches). Below is an overview of current and former servers within Dell's PowerEdge product line. Different models are or were available as towers, 19-inch racks or blades. In the current naming scheme, towers are designated by T, racks by R, and blades by M (for modular). The 19″ rack-servers come in different physical heights expressed in rack units or U. Most modern servers are either 1U or 2U high while in the past the 4U was more common.
  • 4.9K
  • 21 Oct 2022
Topic Review
Guccifer 2.0
"Guccifer 2.0" is a persona which claimed to be the hacker(s) that hacked into the Democratic National Committee (DNC) computer network and then leaked its documents to the media, the website WikiLeaks, and a conference event. Some of the documents "Guccifer 2.0" released to the media appear to be forgeries cobbled together from public information and previous hacks, which had been mixed with disinformation. According to indictments in February 2018, the persona is operated by Russian military intelligence agency GRU. On July 13, 2018, Special Counsel Robert Mueller indicted 12 GRU agents for allegedly perpetrating the cyberattacks. The U.S. Intelligence Community concluded that some of the genuine leaks from "Guccifer 2.0" were part of a series of cyberattacks on the DNC committed by two Russian military intelligence groups, and that "Guccifer 2.0" is actually a persona created by Russian intelligence services to cover for their interference in the 2016 U.S. presidential election. This conclusion is based on analyses conducted by various private sector cybersecurity individuals and firms, including CrowdStrike, Fidelis Cybersecurity, FireEye's Mandiant, SecureWorks, ThreatConnect, Trend Micro, and the security editor for Ars Technica. The Russian government denies involvement in the theft, and "Guccifer 2.0" denied links to Russia. WikiLeaks founder Julian Assange said multiple parties had access to DNC emails and that there was "no proof" Russia was behind the attack. In March 2018, Special Counsel Robert Mueller took over investigation of Guccifer 2.0 from the FBI while it was reported that forensic determination had found the Guccifer 2.0 persona to be a "particular military intelligence directorate (GRU) officer working out of the agency's headquarters on Grizodubovoy Street in Moscow".
  • 4.9K
  • 10 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.
  • 4.9K
  • 14 Oct 2022
Topic Review
False Position Method
In mathematics, the false position method or regula falsi is a very old method for solving an equation in one unknown, that, in modified form, is still in use. In simple terms, the method is the trial and error technique of using test ("false") values for the variable and then adjusting the test value according to the outcome. This is sometimes also referred to as "guess and check". Versions of the method predate the advent of algebra and the use of equations. As an example, consider problem 26 in the Rhind papyrus, which asks for a solution of (written in modern notation) the equation x + x/4 = 15. This is solved by false position, using a technique that predates formally written equations. First, guess that x = 4 to obtain, on the left, 4 + 4/4 = 5. This guess is a good choice since it produces an integer value. However, 4 is not the solution of the original equation, as it gives a value which is three times too small. To compensate, multiply x (currently set to 4) by 3 and substitute again to get 12 + 12/4 = 15, verifying that the solution is x = 12. Modern versions of the technique employ systematic ways of choosing new test values and are concerned with the questions of whether or not an approximation to a solution can be obtained, and if it can, how fast can the approximation be found.
  • 4.9K
  • 15 Nov 2022
Topic Review
Modern Computing in Iran
Iran’s modern computing history can be divided into four distinct periods: (1) Computers were first introduced to Iran in 1962. As a result, the introduction of computers in Iran occurred approximately ten years after introducing computers in developed countries. (2) Computer development, Iran’s computer development era began in 1971 and lasted until 1981. This path was followed by a lot of competition to buy hardware, introduce massive software systems, recruit more manpower, and follow rigorous programs based on the country’s technological realities. (3) Computer revisit: As a result of the Islamic Revolution, improvements and innovations in computers occurred, and a series of general reviews were conducted until 1980. (4) Technological maturity and growth in Iran: Following the reopening of universities in 1983, the next stage of computer development began, with software and hardware becoming widely available. The Persian language and script processing is among this century’s most important works.
  • 4.8K
  • 29 Aug 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.
  • 4.8K
  • 02 Nov 2022
Topic Review
Domain Fronting
Domain fronting is a technique for Internet censorship circumvention that uses different domain names in different communication layers of an HTTPS connection to discreetly connect to a different target domain than is discernable to third parties monitoring the requests and connections. Due to quirks in security certificates, the redirect systems of the content delivery networks (CDNs) used as 'domain fronts', and the protection provided by HTTPS, censors are typically unable to differentiate circumvention ("domain-fronted") traffic from overt non-fronted traffic for any given domain name. As such they are forced to either allow all traffic to the domain front—including circumvention traffic—or block the domain front entirely, which may result in expensive collateral damage and has been likened to "blocking the rest of the Internet".[note 1] Domain fronting does not conform to HTTP standards that require the SNI extension and HTTP Host header to contain the same domain. Large cloud service providers, including Amazon and Google, now actively prohibit domain fronting, which has made it "largely non-viable"[note 1] as a censorship bypass technique.
  • 4.8K
  • 06 Oct 2022
Topic Review
List of DOS Commands
This article presents a list of commands used by DOS operating systems, especially as used on x86-based IBM PC compatibles (PCs). Other DOS operating systems are not part of the scope of this list. In DOS, many standard system commands were provided for common tasks such as listing files on a disk or moving files. Some commands were built into the command interpreter, others existed as external commands on disk. Over the several generations of DOS, commands were added for the additional functions of the operating system. In the current Microsoft Windows operating system, a text-mode command prompt window, cmd.exe, can still be used.
  • 4.8K
  • 14 Oct 2022
Topic Review
Video Games in Education
This page includes some history of video games being used as an additional or alternative method to traditional education. This page presents why using video games are beneficial to use for educational purposes in the classroom as well as the limitations. This page additionally discusses how learning from video games outside the classroom is possible as well.
  • 4.8K
  • 04 Nov 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.
  • 4.8K
  • 11 Nov 2022
Topic Review
Salient Object Detection
Detection and localization of regions of images that attract immediate human visual attention is currently an intensive area of research in computer vision. The capability of automatic identification and segmentation of such salient image regions has immediate consequences for applications in the field of computer vision, computer graphics, and multimedia. A large number of salient object detection (SOD) methods have been devised to effectively mimic the capability of the human visual system to detect the salient regions in images. These methods can be broadly categorized into two categories based on their feature engineering mechanism: conventional or deep learning-based. In this survey, most of the influential advances in image-based SOD from both conventional as well as deep learning-based categories have been reviewed in detail. Relevant saliency modeling trends with key issues, core techniques, and the scope for future research work have been discussed in the context of difficulties often faced in salient object detection. Results are presented for various challenging cases for some large-scale public datasets. Different metrics considered for assessment of the performance of state-of-the-art salient object detection models are also covered. Some future directions for SOD are presented towards end.
  • 4.8K
  • 19 Nov 2020
Topic Review
Windows 10 Version History (Version 1903)
The Windows 10 May 2019 Update (also known as version 1903 and codenamed "19H1") is the seventh major update to Windows 10 and the first to use a more descriptive codename (including the year and the order released) instead of the "Redstone" or "Threshold" codename. It carries the build number 10.0.18362.
  • 4.8K
  • 16 Nov 2022
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