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Topic Review
Health Information on the Internet
Health information on the Internet refers to all health-related information communicated through or available on the Internet.
  • 1.4K
  • 16 Nov 2022
Topic Review
Elie Bursztein
Elie Bursztein (born 1 June 1980) leads the anti-abuse research team at Google.[r 1] He is best known for his research on anti-fraud and abuse,[r 2] his novel attacks against web service and video games and his work on applied cryptography.[p 1][p 2] Prior to Google Bursztein was a post-doctoral fellow in computer science at Stanford University, where he focused on CAPTCHAs security[p 3][p 4] and usability.[p 5][p 6]
  • 1.4K
  • 20 Oct 2022
Topic Review
Divide and Conquer Algorithm
In computer science, divide and conquer is an algorithm design paradigm based on multi-branched recursion. A divide and conquer algorithm works by recursively breaking down a problem into two or more sub-problems of the same or related type, until these become simple enough to be solved directly. The solutions to the sub-problems are then combined to give a solution to the original problem. This divide and conquer technique is the basis of efficient algorithms for all kinds of problems, such as sorting (e.g., quicksort, merge sort), multiplying large numbers (e.g. the Karatsuba algorithm), finding the closest pair of points, syntactic analysis (e.g., top-down parsers), and computing the discrete Fourier transform (FFTs) . Understanding and designing divide and conquer algorithms is a complex skill that requires a good understanding of the nature of the underlying problem to be solved. As when proving a theorem by induction, it is often necessary to replace the original problem with a more general or complicated problem in order to initialize the recursion, and there is no systematic method for finding the proper generalization. These divide and conquer complications are seen when optimizing the calculation of a Fibonacci number with efficient double recursion . The correctness of a divide and conquer algorithm is usually proved by mathematical induction, and its computational cost is often determined by solving recurrence relations.
  • 1.4K
  • 01 Nov 2022
Topic Review
Stoned (Computer Virus)
Stoned is a boot sector computer virus created in 1987. It is one of the first viruses and is thought to have been written by a student in Wellington, New Zealand. By 1989 it had spread widely in New Zealand and Australia, and variants became very common worldwide in the early 1990s. A computer infected with the original version had a one in eight probability that the screen would declare: "Your PC is now Stoned!", a phrase found in infected boot sectors of infected floppy disks and master boot records of infected hard disks, along with the phrase "Legalise Marijuana". Later variants produced a range of other messages.
  • 1.4K
  • 03 Nov 2022
Topic Review
Convolution (Computer Science)
In computer science, specifically formal languages, convolution (sometimes referred to as zip) is a function which maps a tuple of sequences into a sequence of tuples. This name zip derives from the action of a zipper in that it interleaves two formerly disjoint sequences. The reverse function is unzip which performs a deconvolution.
  • 1.4K
  • 28 Sep 2022
Topic Review
Heterogeneous Relation
In mathematics, a heterogeneous relation is a binary relation, a subset of a Cartesian product A × B, where A and B are distinct sets. The prefix hetero is from the Greek ἕτερος (heteros, "other, another, different"). A heterogeneous relation has been called a rectangular relation, suggesting that it does not have the square-symmetry of a homogeneous relation on a set where A = B. Commenting on the development of binary relations beyond homogeneous relations, researchers wrote, "...a variant of the theory has evolved that treats relations from the very beginning as heterogeneous or rectangular, i.e. as relations where the normal case is that they are relations between different sets." Developments in algebraic logic have facilitated usage of binary relations. The calculus of relations includes the algebra of sets, extended by composition of relations and the use of converse relations. The inclusion R ⊆ S, meaning that aRb implies aSb, sets the scene in a lattice of relations. But since [math]\displaystyle{ P \subseteq Q \equiv (P \cap \bar{Q} = \varnothing ) \equiv (P \cap Q = P), }[/math] the inclusion symbol is superfluous. Nevertheless, composition of relations and manipulation of the operators according to Schröder rules, provides a calculus to work in the power set of A × B. In contrast to homogeneous relations, the composition of relations operation is only a partial function. The necessity of matching range to domain of composed relations has led to the suggestion that the study of heterogeneous relations is a chapter of category theory as in the category of sets, except that the morphisms of this category are relations. The objects of the category Rel are sets, and the relation-morphisms compose as required in a category.
  • 1.4K
  • 21 Nov 2022
Topic Review
IoT Technologies during COVID-19
The COVID-19 pandemic provided a much-needed sanity check for IoT-inspired frameworks and solutions. IoT solutions such as remote health monitoring and contact tracing provided support for authorities to successfully manage the spread of the coronavirus. 
  • 1.3K
  • 06 May 2021
Topic Review
List of Folding@home Cores
The distributed-computing project Folding@home uses scientific computer programs, referred to as "cores" or "fahcores", to perform calculations. Folding@home's cores are based on modified and optimized versions of molecular simulation programs for calculation, including TINKER, GROMACS, AMBER, CPMD, SHARPEN, ProtoMol and Desmond. These variants are each given an arbitrary identifier (Core xx). While the same core can be used by various versions of the client, separating the core from the client enables the scientific methods to be updated automatically as needed without a client update.
  • 1.3K
  • 29 Nov 2022
Topic Review
Palatine Lion
The Palatine Lion (German: Pfälzer Löwe), less commonly the Palatinate Lion, is an heraldic charge (see also: heraldic lions). It was originally part of the family coat of arms of the House of Wittelsbach and is found today on many coats of arms of municipalities, counties and regions in South Germany and the Austrian Innviertel.
  • 1.3K
  • 08 Nov 2022
Topic Review
Learning-Assisted Rain Attenuation Prediction Models
Rain attenuation becomes significant to degrade the earth-space or terrestrial radio link’s signal-to-noise ratio (SNR). So, to maintain the desired SNR level, with the help of fade mitigation techniques (FMTs), it needs to control transmitted signals power considering the expected rainfall. However, since the rain event is a random phenomenon, the rain attenuation that may be experienced by a specific link is difficult to estimate. Many empirical, physical, and compound nature-based models exist in the literature to predict the expected rain attenuation. Furthermore, many optimizations and decision-making functions have become simpler since the development of the learning-assisted (LA) technique. In this work, the LA rain attenuation (LARA) model was classified based on input parameters. Besides, for comparative analysis, each of the supported frequency components of LARA models were tabulated, and an accurate contribution of each model was identified. In contrast to all the currently available LARA models, the accuracy and correlation of input-output parameters are presented. Additionally, it summarizes and discusses open research issues and challenges.
  • 1.3K
  • 01 Jun 2021
Topic Review
Mojikyō
Conceptualized in 1996, the first version of the CD-ROM was released in July 1997. For a time, the Mojikyō Institute also offered a web subscription, termed "Mojikyō WEB" (文字鏡WEB), which had more up-to-date characters. (As of September 2006), Mojikyō encoded 174,975 characters. Among those, 150,366 characters ([math]\displaystyle{ \approx }[/math]86%) then belonged to the extended Chinese–Japanese–Korean–Vietnamese (CJKV)[note 2] family. Many of Mojikyō's characters are considered obsolete or obscure, and are not encoded by any other character set, including the most widely used international text encoding standard, Unicode. Originally a paid proprietary software product, as of 2015, the Mojikyō Institute began to upload its latest releases to Internet Archive as freeware, as a memorial to honor one of its developers, Tokio Furuya (古家時雄), who died that year. On December 15, 2018, version 4.0 was released. The next day, Ishikawa announced that without Furuya this would be the final release of Mojikyō.
  • 1.3K
  • 09 Oct 2022
Topic Review
Famous Photographical Manipulations
Photographical Manipulation is the alteration of a photograph. The U.S. National Press Photographers Association (NPPA) Digital Manipulation Code of Ethics states: “As journalists we believe the guiding principle of our profession is accuracy; therefore, we believe it is wrong to alter the content of a photograph in any way that deceives the public. As photojournalists, we have the responsibility to document society and to preserve its images as a matter of historical record. It is clear that the emerging electronic technologies provide new challenges to the integrity of photographic images... in light of this, we the National Press Photographers Association, reaffirm the basis of our ethics: Accurate representation is the benchmark of our profession. We believe photojournalistic guidelines for fair and accurate reporting should be the criteria for judging what may be done electronically to a photograph. Altering the editorial content... is a breach of the ethical standards recognized by the NPPA.”
  • 1.3K
  • 17 Oct 2022
Topic Review
MLT (Hacktivist)
MLT, real name Matt Telfer, is a former grey hat computer hacker and member of TeaMp0isoN. MLT was arrested in May 2012 in relation to his activities within TeaMp0isoN, a computer-hacking group which claimed responsibility for many high-profile attacks, including website defacements of the United Nations , Facebook, NATO, BlackBerry, T-Mobile USA and several other large sites in addition to high-profile denial-of-service attacks and leaks of confidential data.
  • 1.3K
  • 18 Nov 2022
Topic Review
Differential Privacy
Differential privacy is a statistical technique that aims to provide means to maximize the accuracy of queries from statistical databases while measuring (and, thereby, hopefully minimizing) the privacy impact on individuals whose information is in the database. Differential privacy was developed by cryptographers and is thus often associated with cryptography, and it draws much of its language from cryptography. Although differential privacy is often discussed in the context of identifying individuals whose information may be a database, identification and reidentification attacks are not included within the original differential privacy framework.
  • 1.3K
  • 25 Oct 2022
Topic Review
Inventory (Library)
Inventories are the one method that libraries use to determine whether some items in their collection are in need of preservation or conservation activities. A modern inventory might involve examining item by item with a barcode scanner and a laptop, with the objective of adjusting bibliographic and item records in theirs and OCLC's WorldCat databases. Using a laptop and handheld bar code reader will “reduce human error and inconsistencies, while helping to maintain staff concentration and enthusiasm for the project”. Print materials in the digital age, though dramatically decreased in size compared to e-print materials, are still valuable components of a library's collection. Increasing print material's accessibility, and reducing user frustration, make the inventory process an effective tool in improving library service quality. “When library users are unable to find materials in the expected locations, they lose confidence in the library catalog as well as in the library itself”. Missing or mislabeled books have a direct impact on the quality of library services. Maintaining the stacks through inventories and shelf reading can mitigate staff time lost searching for missing or mislabeled items. Libraries have thousands of books; large academic libraries may have millions of books;. Doing an annual (or less frequent) physical inventory with the laying on of hands on each individual item may not be practical for several reasons. It may not be financially feasible, employees required may not have extra time to devote to such an inventory, and there are no financial rewards for the Library for completing an inventory. Problems that are discovered (books in need of repurchase, rebinding, repair, or digitization) may require solutions that are expensive and labor-intensive. Because of these restraints, inventories may not take place for decades, if ever, at large academic institutions. By contrast, complete inventories are often a regular part of the school library media specialist's job at K-12 institutions, where inventory may be a legal requirement that shows that the libraries are accountable for the money they have spent throughout the year. Checking for lost books and materials can be similarly compared to auditing. However, there are alternative options to performing a complete inventory, such as performing a selective inventory. Selective inventory can be performed by circumstance or by data prediction. Physical space is a premium in libraries. Inventorying mini collections before relocating them to their new location presents the library with an opportunity to perform a selective inventory project. An alternative to opportunistic selective inventory projects is Kohl's (1982) assertion that circulation statistics, book search statistics, and ILL statistics can be useful tools in identifying areas as possible selective inventory areas. He writes, “areas in need of an inventory can be identified through the use of predictive data”. Once the objectives for accuracy and methods of measuring have been established “the criteria need to be quantified. An overall measure of the inventory accuracy should be maintained as a management key performance indicator”.
  • 1.3K
  • 01 Nov 2022
Topic Review
2D Filters
Two dimensional filters have seen substantial development effort due to their importance and high applicability across several domains. In the 2-D case the situation is quite different from the 1-D case, because the multi-dimensional polynomials cannot in general be factored. This means that an arbitrary transfer function cannot generally be manipulated into a form required by a particular implementation. The input-output relationship of a 2-D IIR filter obeys a constant-coefficient linear partial difference equation from which the value of an output sample can be computed using the input samples and previously computed output samples. Because the values of the output samples are fed back, the 2-D filter, like its 1-D counterpart, can be unstable.
  • 1.3K
  • 26 Oct 2022
Topic Review
Aural Cascading Style Sheets
Cascading Style Sheets (CSS) is a style sheet language used for describing the presentation of a document written in a markup language like HTML. CSS is a cornerstone technology of the World Wide Web, alongside HTML and JavaScript. CSS is designed to enable the separation of presentation and content, including layout, colors, and fonts. This separation can improve content accessibility, provide more flexibility and control in the specification of presentation characteristics, enable multiple web pages to share formatting by specifying the relevant CSS in a separate .css file, and reduce complexity and repetition in the structural content. Separation of formatting and content also makes it feasible to present the same markup page in different styles for different rendering methods, such as on-screen, in print, by voice (via speech-based browser or screen reader), and on Braille-based tactile devices. CSS also has rules for alternate formatting if the content is accessed on a mobile device. The name cascading comes from the specified priority scheme to determine which style rule applies if more than one rule matches a particular element. This cascading priority scheme is predictable. The CSS specifications are maintained by the World Wide Web Consortium (W3C). Internet media type (MIME type) text/css is registered for use with CSS by RFC 2318 (March 1998). The W3C operates a free CSS validation service for CSS documents. In addition to HTML, other markup languages support the use of CSS including XHTML, plain XML, SVG, and XUL.
  • 1.3K
  • 14 Nov 2022
Topic Review
Hosts (File)
The computer file hosts is an operating system file that maps hostnames to IP addresses. It is a plain text file. Originally a file named HOSTS.TXT was manually maintained and made available via file sharing by Stanford Research Institute for the ARPANET membership, containing the hostnames and address of hosts as contributed for inclusion by member organizations. The Domain Name System, first described in 1983 and implemented in 1984, automated the publication process and provided instantaneous and dynamic hostname resolution in the rapidly growing network. In modern operating systems, the hosts file remains an alternative name resolution mechanism, configurable often as part of facilities such as the Name Service Switch as either the primary method or as a fallback method.
  • 1.3K
  • 15 Nov 2022
Topic Review
DSQuery
As the next version of Windows NT after Windows 2000, as well as the successor to Windows Me, Windows XP introduced many new features but it also removed some others.
  • 1.3K
  • 08 Nov 2022
Topic Review
Alundra 2: A New Legend Begins
Alundra 2: A New Legend Begins (アランドラ2 魔進化の謎, Arandora 2 Ma Shinka no Nazo, Alundra 2: The Mystery of Magic Evolution) is an action role-playing game developed by Matrix Software for the Sony PlayStation. It was published by SCEI in Japan and Activision worldwide. Unlike its predecessor, Alundra, Alundra 2 features a 3D look which opens up a new world of puzzles. Also, despite its title, Alundra 2 is a standalone sequel, and has no ties with the original. It has a whole new story with a different set of characters, including the main character, Flint. Compared to the darker storyline of Alundra, Alundra 2 has a more light-hearted storyline.
  • 1.3K
  • 03 Nov 2022
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