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Sources Of Electromagnetic Interference
Source may refer to: Research * Historical document * Historical source * Source (intelligence) or sub source, typically a confidential provider of non open-source intelligence * Source (journalism), a person, publication, publishing institute or other record or document that gives information * Source document, a document in which data collected for a clinical trial is first recorded * Source text, in research (especially in the humanities), a source of information referred to by citation ** Primary source, a first-hand written evidence of history made at the time of the event by someone who was present ** Secondary source, a written account of history based upon the evidence from primary sources ** Tertiary source, a compilation based upon primary and secondary sources * Sources (website), a directory of expert contacts and media spokespersons * Open source, a philosophy of dissemination of intellectual products Law * Sources of international law, the materials and processes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Historical Document
Historical documents are original documents that contain important historical information about a person, place, or event and can thus serve as primary sources as important ingredients of the historical methodology. Significant historical documents can be deeds, laws, accounts of battles (often given by the victors or persons sharing their viewpoint), or the exploits of the powerful. Though these documents are of historical interest, they do not detail the daily lives of ordinary people, or the way society functioned. Anthropologists, historians and archeologists generally are more interested in documents that describe the everyday life, day-to-day lives of ordinary people, indicating what they ate, their interaction with other members of their households and social groups, and their states of mind. It is this information that allows them to try to understand and describe the way society was functioning at any particular time in history. Greek ostraka provide good examples of hist ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Field-effect Transistor
The field-effect transistor (FET) is a type of transistor that uses an electric field to control the current through a semiconductor. It comes in two types: junction FET (JFET) and metal-oxide-semiconductor FET (MOSFET). FETs have three terminals: ''source'', ''gate'', and ''drain''. FETs control the current by the application of a voltage to the gate, which in turn alters the conductivity between the drain and source. FETs are also known as unipolar transistors since they involve single-carrier-type operation. That is, FETs use either electrons (n-channel) or holes (p-channel) as charge carriers in their operation, but not both. Many different types of field effect transistors exist. Field effect transistors generally display very high input impedance at low frequencies. The most widely used field-effect transistor is the MOSFET (metal–oxide–semiconductor field-effect transistor). History The concept of a field-effect transistor (FET) was first patented by the Austr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Source (programming Language)
Source is a family of sublanguages of JavaScript, developed for the textbook Structure and Interpretation of Computer Programs, JavaScript Edition (SICP JS). The JavaScript sublanguages Source §1, Source §2, Source §3 and Source §4 are designed to be just expressive enough to support all examples of the respective chapter of the textbook. Purpose and design principle During the development of SICP JS, starting in 2008, it became clear that purpose-designed sublanguages of JavaScript would contribute to the learning experience. Initially called "JediScript" and inspired by the book "JavaScript: The Good Parts" by Douglas Crockford, the Source sublanguages follow the chapters of SICP JS; each language Source §x is a sublanguage of the next language Source §(x+1). Following the minimalistic approach of SICP JS, implementations of Source are expected to remove any JavaScript language features that are not included in the language specification. Features Source §1 is a ve ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Information Theory
Information theory is the mathematical study of the quantification (science), quantification, Data storage, storage, and telecommunications, communication of information. The field was established and formalized by Claude Shannon in the 1940s, though early contributions were made in the 1920s through the works of Harry Nyquist and Ralph Hartley. It is at the intersection of electronic engineering, mathematics, statistics, computer science, Neuroscience, neurobiology, physics, and electrical engineering. A key measure in information theory is information entropy, entropy. Entropy quantifies the amount of uncertainty involved in the value of a random variable or the outcome of a random process. For example, identifying the outcome of a Fair coin, fair coin flip (which has two equally likely outcomes) provides less information (lower entropy, less uncertainty) than identifying the outcome from a roll of a dice, die (which has six equally likely outcomes). Some other important measu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Source Code
In computing, source code, or simply code or source, is a plain text computer program written in a programming language. A programmer writes the human readable source code to control the behavior of a computer. Since a computer, at base, only understands machine code, source code must be Translator (computing), translated before a computer can Execution (computing), execute it. The translation process can be implemented three ways. Source code can be converted into machine code by a compiler or an assembler (computing), assembler. The resulting executable is machine code ready for the computer. Alternatively, source code can be executed without conversion via an interpreter (computing), interpreter. An interpreter loads the source code into memory. It simultaneously translates and executes each statement (computer science), statement. A method that combines compilation and interpretation is to first produce bytecode. Bytecode is an intermediate representation of source code tha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Communication Source
A source or sender is one of the basic concepts of communication and information processing. Sources are objects which encode message data and transmit the information, via a channel, to one or more observers (or receivers). In the strictest sense of the word, particularly in information theory, a ''source'' is a process that generates message data that one would like to communicate, or reproduce as exactly as possible elsewhere in space or time. A source may be modelled as memoryless, ergodic, stationary, or stochastic, in order of increasing generality. ''Communication Source'' combines ''Communication and Mass Media Complete'' and ''Communication Abstracts'' to provide full-text access to more than 700 journals, and indexing and abstracting for more than 1,000 core journals. Coverage dating goes back to 1900. Content is derived from academic journals, conference papers, conference proceedings, trade publications, magazines and periodicals. A transmitter can be e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Source (command)
In a Unix shell, the full stop called the dot command (.) is a command that evaluates commands in a computer file in the current execution context. In the C shell, a similar functionality is provided as the source command, and this name is seen in "extended" POSIX shells as well. The dot command is not to be confused with a dot file, which is a dot-prefixed hidden file or hidden directory. Nor is it to be confused with the ./scriptfile notation for running commands, which is simply a relative path pointing to the current directory (notated in Unix as a '.' character, and typically outside of the Path variable). Arguments The filename is the dot command's first argument. When this argument does not contain a slash, the shell will search for the file in all directories defined in the PATH environment variable. Unlike normal commands which are also found in PATH, the file to source does not have to be executable. Otherwise the filename is considered as a simple path to th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Voltage Source
A voltage source is a two-terminal (electronics), terminal device which can maintain a fixed voltage. An ideal voltage source can maintain the fixed voltage independent of the load resistance or the output Electric current, current. However, a real-world voltage source cannot supply unlimited current. A voltage source is the dual (electronics), dual of a current source. Real-world sources of electrical energy, such as Electric battery, batteries and Electric generator, generators, can be modeled for analysis purposes as a combination of an ideal voltage source and additional combinations of Electrical impedance, impedance elements. Ideal voltage sources An ideal voltage source is a two-terminal device that maintains a fixed voltage drop across its terminals. It is often used as a mathematical abstraction that simplifies the analysis of real electric circuits. If the voltage across an ideal voltage source can be specified independently of any other variable in a circuit, it ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sound
In physics, sound is a vibration that propagates as an acoustic wave through a transmission medium such as a gas, liquid or solid. In human physiology and psychology, sound is the ''reception'' of such waves and their ''perception'' by the brain. Only acoustic waves that have frequency, frequencies lying between about 20 Hz and 20 kHz, the audio frequency range, elicit an auditory percept in humans. In air at atmospheric pressure, these represent sound waves with wavelengths of to . Sound waves above 20 kHz are known as ultrasound and are not audible to humans. Sound waves below 20 Hz are known as infrasound. Different animal species have varying hearing ranges, allowing some to even hear ultrasounds. Definition Sound is defined as "(a) Oscillation in pressure, stress, particle displacement, particle velocity, etc., propagated in a medium with internal forces (e.g., elastic or viscous), or the superposition of such propagated oscillation. (b) Auditory sen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radioactive Source
A radioactive source is a known quantity of a radionuclide which emits ionizing radiation, typically one or more of the radiation types gamma rays, alpha particles, beta particles, and neutron radiation. Sources can be used for irradiation, where the radiation performs a significant ionising function on a target material, or as a radiation metrology source, which is used for the calibration of radiometric process and radiation protection instrumentation. They are also used for industrial process measurements, such as thickness gauging in the paper and steel industries. Sources can be sealed in a container (highly penetrating radiation) or deposited on a surface (weakly penetrating radiation), or they can be in a fluid. As an irradiation source they are used in medicine for radiation therapy and in industry for such as industrial radiography, food irradiation, sterilization (microbiology), sterilization, vermin disinfestation, and Cross-linked polyethylene, irradiation crosslinki ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Point Source
A point source is a single identifiable ''localized'' source of something. A point source has a negligible extent, distinguishing it from other source geometries. Sources are called point sources because, in mathematical modeling, these sources can usually be approximated as a mathematical point to simplify analysis. The actual source need not be physically small if its size is negligible relative to other length scales in the problem. For example, in astronomy, stars are routinely treated as point sources, even though they are in actuality much larger than the Earth. In three dimensions, the density of something leaving a point source decreases in proportion to the inverse square of the distance from the source, if the distribution is isotropic, and there is no absorption or other loss. Mathematics In mathematics, a point source is a singularity from which flux or flow is emanating. Although singularities such as this do not exist in the observable universe, mathematical ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Light Source
Light, visible light, or visible radiation is electromagnetic radiation that can be visual perception, perceived by the human eye. Visible light spans the visible spectrum and is usually defined as having wavelengths in the range of 400–700 nanometres (nm), corresponding to frequency, frequencies of 750–420 terahertz (unit), terahertz. The visible band sits adjacent to the infrared (with longer wavelengths and lower frequencies) and the ultraviolet (with shorter wavelengths and higher frequencies), called collectively ''optical radiation''. In physics, the term "light" may refer more broadly to electromagnetic radiation of any wavelength, whether visible or not. In this sense, gamma rays, X-rays, microwaves and radio waves are also light. The primary properties of light are intensity (physics), intensity, propagation direction, frequency or wavelength spectrum, and polarization (waves), polarization. Its speed of light, speed in vacuum, , is one of the fundamental physi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
