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HandWiki is the world's largest wiki-style encyclopedia dedicated to science, technology and computing. It allows you to create and edit articles as long as you have external citations and login account. In addition, this is a content management environment that can be used for collaborative editing of original scholarly content, such as books, manuals, monographs and tutorials.

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Shock Capturing Method
In computational fluid dynamics, shock-capturing methods are a class of techniques for computing inviscid flows with shock waves. The computation of flow containing shock waves is an extremely difficult task because such flows result in sharp, discontinuous changes in flow variables such as pressure, temperature, density, and velocity across the shock.
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  • 25 Nov 2022
Topic Review
S3 ViRGE
The S3 Virtual Reality Graphics Engine (ViRGE) graphics chipset was one of the first 2D/3D accelerators designed for the mass market. Introduced in 1995 by then graphics powerhouse S3, Inc., the ViRGE was S3's first foray into 3D-graphics. The S3/Virge was the successor to the successful Trio64V+. ViRGE/325 was pin compatible with the Trio64 chip, retaining the DRAM-framebuffer interface (up to 4MB), and clocking both the core and memory up to 80 MHz. In Windows, Virge was benchmarked as the fastest DRAM-based accelerator of the era. The VRAM-based version, ViRGE/VX, was actually slower in lower resolutions, but had a faster RAMDAC to support high-resolution modes not available on the 325.
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  • 25 Nov 2022
Topic Review
Action
In physics, action is a numerical value describing how a physical system has changed over time. Action is significant because the equations of motion of the system can be derived through the principle of stationary action. In the simple case of a single particle moving with a specified velocity, the action is the momentum of the particle times the distance it moves, added up along its path, or equivalently, twice its kinetic energy times the length of time for which it has that amount of energy, added up over the period of time under consideration. For more complicated systems, all such quantities are added together. More formally, action is a mathematical functional which takes the trajectory, also called path or history, of the system as its argument and has a real number as its result. Generally, the action takes different values for different paths. Action has dimensions of energy × time or momentum × length, and its SI unit is joule-second (like the Planck constant h).
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  • 25 Nov 2022
Topic Review
Hyoscine
Hyoscine, also known as scopolamine, is a medication used to treat motion sickness and postoperative nausea and vomiting. It is also sometimes used before surgery to decrease saliva. When used by injection, effects begin after about 20 minutes and last for up to 8 hours. It may also be used by mouth and via a skin patch. Common side effects include sleepiness, blurred vision, dilated pupils, and dry mouth. It is not recommended in people with angle-closure glaucoma or bowel obstruction. It is unclear if use during pregnancy is safe; however, it appears to be safe during breastfeeding. Hyoscine is in the antimuscarinic family of medications and works by blocking some of the effects of acetylcholine within the nervous system. Hyoscine was first written about in 1881 and started to be used for anesthesia around 1900. It is on the World Health Organization's List of Essential Medicines. Hyoscine is main active component produced by certain plants of the nightshade family which historically have been used as psychoactive drugs due to their hallucinogenic effects. The name "scopolamine" is derived from one type of nightshade known as Scopolia while the name "hyoscine" is derived from another type known as Hyoscyamus niger.
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  • 25 Nov 2022
Topic Review
Dog-Whistle Politics
Dog-whistle politics is the use of coded or suggestive language in politics to garner support from a wider audience for a candidate. Dog whistles serve the purpose of attracting the intended political audience without garnering ire with opposing audiences, similar to ultrasonic dog whistles used in sheepherding. The concept of dog-whistles has similarities to the concept of code words. Accusations of dog-whistling may be used to accuse an individual of expressing a "hidden" meaning when no such message was intended and the actual words used are innocuous. Such accusations can be a form of political correctness or gaslighting and are by their nature impossible to refute. An example is the accusation that using the phrase "international banks" is evidence of anti-Semitism. When it exists, a dog-whistle is a type of doublespeak used in political messaging. Dog whistles work by employing language that has normal meanings to the majority, but can be implied or loaded to mean very specific things to intended recipients. One example commonly believed to be dog whistling may include is the use of 'family values' as a signal to Christians that the candidate is Christian and would support policies related to Christian values without raising flags among the non-religious who might oppose a Christian candidate. This type of dog whistle would serve the purpose of gaining popularity with Christians without losing popularity with non-Christians.
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  • 25 Nov 2022
Topic Review
Interactive Visualization
Interactive visualization or interactive visualisation is a branch of graphic visualization in computer science that involves studying how humans interact with computers to create graphic illustrations of information and how this process can be made more efficient. For a visualization to be considered interactive it must satisfy two criteria: One particular type of interactive visualization is virtual reality (VR), where the visual representation of information is presented using an immersive display device such as a stereo projector (see stereoscopy). VR is also characterized by the use of a spatial metaphor, where some aspect of the information is represented in three dimensions so that humans can explore the information as if it were present (where instead it was remote), sized appropriately (where instead it was on a much smaller or larger scale than humans can sense directly), or had shape (where instead it might be completely abstract). Another type of interactive visualization is collaborative visualization, in which multiple people interact with the same computer visualization to communicate their ideas to each other or to explore information cooperatively. Frequently, collaborative visualization is used when people are physically separated. Using several networked computers, the same visualization can be presented to each person simultaneously. The people then make annotations to the visualization as well as communicate via audio (i.e., telephone), video (i.e., a video-conference), or text (i.e., IRC) messages.
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  • 25 Nov 2022
Topic Review
Emotional Dysregulation
Emotional dysregulation is a term used in the mental health community that refers to emotional responses that are poorly modulated and do not lie within the accepted range of emotive response. Emotional dysregulation can be associated with an experience of early psychological trauma, brain injury, or chronic maltreatment (such as child abuse, child neglect, or institutional neglect/abuse), and associated disorders such as reactive attachment disorder. Emotional dysregulation may be present in people with psychiatric disorders such as attention deficit hyperactivity disorder, autism spectrum disorders, bipolar disorder, borderline personality disorder, complex post-traumatic stress disorder, and fetal alcohol spectrum disorders. In such cases as borderline personality disorder and complex post-traumatic stress disorder, hypersensitivity to emotional stimuli causes a slower return to a normal emotional state. This is manifested biologically by deficits in the frontal cortices of the brain. Possible manifestations of emotional dysregulation include extreme tearfulness, angry outbursts or behavioral outbursts such as destroying or throwing objects, aggression towards self or others, and threats to kill oneself. Emotional dysregulation can lead to behavioral problems and can interfere with a person's social interactions and relationships at home, in school, or at place of employment.
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  • 25 Nov 2022
Topic Review
Theravāda Abhidhamma
The Theravāda Abhidhamma is a scholastic systematization of the Theravāda school's understanding of the highest Buddhist teachings (Abhidhamma). These teachings are traditionally believed to have been taught by the Buddha, though modern scholars date the texts of the Abhidhamma Piṭaka to the 3rd century BCE. Theravāda traditionally sees itself as the vibhajjavāda ("the teaching of analysis"), which reflects the analytical (vibhajjati) method used by the Buddha and early Buddhists to investigate the nature of the person and other phenomena. According to Bhikkhu Bodhi, a modern Theravāda scholar, the Abhidhamma is "simultaneously a philosophy, a psychology and an ethics, all integrated into the framework of a program for liberation." There are different textual layers of Abhidhamma literature. The earliest Abhidhamma works are found in the Pali Canon. Then there are exegetical works which were composed in Sri Lanka in the 5th century. There are also later sub-commentarial works composed in later historical periods.
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  • 25 Nov 2022
Topic Review
Holomorphic Embedding Load Flow Method
The Holomorphic Embedding Load-flow Method (HELM) is a solution method for the power flow equations of electrical power systems. Its main features are that it is direct (that is, non-iterative) and that it mathematically guarantees a consistent selection of the correct operative branch of the multivalued problem, also signalling the condition of voltage collapse when there is no solution. These properties are relevant not only for the reliability of existing off-line and real-time applications, but also because they enable new types of analytical tools that would be impossible to build with existing iterative load flow methods (due to their convergence problems). An example of this would be decision-support tools providing validated action plans in real time. The HELM load flow algorithm was invented by Antonio Trias and has been granted two US Patents. A detailed description was presented at the 2012 IEEE PES General Meeting and subsequently published. The method is founded on advanced concepts and results from complex analysis, such as holomorphicity, the theory of algebraic curves, and analytic continuation. However, the numerical implementation is rather straightforward as it uses standard linear algebra and the Padé approximation. Additionally, since the limiting part of the computation is the factorization of the admittance matrix and this is done only once, its performance is competitive with established fast-decoupled loadflows. The method is currently implemented into industrial-strength real-time and off-line packaged EMS applications.
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  • 25 Nov 2022
Topic Review
Treatments for PTSD
Posttraumatic stress disorder (PTSD) is a psychiatric disorder that can develop in certain individuals after exposure to traumatic events, such as combat and sexual assault. PTSD is commonly treated with various types of psychotherapy and pharmacotherapy.
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