Signal theory - Signal theory Signal theory provides a set of special mathematical approaches for use in a wide range of applications. High-level perceptions include: Amplitude, phase, resonance, Q (Q for "quality", means the strength of a resonance), time constant (of a filter), great-signal and small-signal bandwidth, maximum output swing, noise floor. Low-level perceptions include the whole spectrum of mathematics, for example integrals and differentials. If you incidentally are in statistical physics or op-amp electronics you are common with this stuff..
Signal (information theory) - Signal (information theory) A signal is an abstract element of information, or more exactly usually a flow of information (in either one or several dimensions). The signal can be either analog or digital. The former is a continuous flow of information in some framework (the signal value does not need to be continuous), while digital signals are constant within some constant temporal (or spatial) intervals. A typical signal is sound such asspeech whereby the signal carries the information of the spoken words, the identity of the speaker and for example, emotional cues. Another typical signal is a radio transmission which, in turn, can carry the speech sound-signal. Both sound and radio signals are analog signals. The frequency spectrum of an analog signal can be evaluated with.
Information theory - Information theory Information theory is a branch of the mathematical theory of probability and mathematical statistics, that deals with the concepts of information and information entropy, communication systems, data transmission and rate distortion theory, cryptography, signal-to-noise ratios, data compression, and related topics. It is not to be confused with library and information science or information technology. Claude E. Shannon (1916-2001) has been called "the father of information theory" (ISBN 0252725484). His theory "considered the transmission of information as a statistical phenomenon" and gave communications engineers a way to determine the capacity of a communication channel in terms of the common currency of bits. The transmission part of the theory is not "concerned with the content of information or the message itself," though the complementary wing of information.
Handicap theory - Handicap theory The handicap theory is an idea proposed by the Israeli biologist Amotz Zahavi. It concerns the way in which animals communicate through their behaviour, and makes the paradoxical claim that certain forms of animal behaviour (and features of animal anatomy supporting them) may have evolved because they apparently act to reduce the chances of individual survival of the animal exhibiting the behaviour. The reasoning supporting this claim depends on considering the question as to how an animal that is the recipient of communication can be assured that the information conveyed is accurate (ie that the signal is honest). The classic example is that of stotting in gazelles. This behaviour consists in the gazelle initially running slowly and jumping high when it is threatened by a.
Gate control theory of pain - Gate control theory of pain The gate control theory of pain of Ron Melzack and Philip Wall arises from evolutionary psychology. It holds that evolution of intelligence in any natural environment, historically, begins with the recognition of the entity's own body - called the kinesthetic sense. Pain, in this view, is then a part of this very sense, a way in which parts of the body learn where they should be, and where not to be. Experiments on dogs which grew up confined in cages, who when released were excited, constantly ran around, and when pain (such as contact with a burning match or being pinched) is encountered, required several attempts to learn to avoid it, seemed to demonstrate that pain is understood and avoided only by experience.
Digital signal processing - Digital signal processing Digital signal processing (DSP) is the study of signals in a digital representation and the processing methods of these signals. DSP and analog signal processing are subsets of signal processing. It has three major subfields: audio signal processing, digital image processing and speech processing. In DSP, engineers most commonly study digital signals in one of the following domains: time domain (one-dimensional signals), spatial domain (multidimensional signals), frequency domain, autocorrelation domain, and wavelet domains. They choose the domain in which to process a signal by making an educated guess (or trying out different possibilities) as to which domain best represents the essential characteristics of the signal. A sequence of samples from a measuring device produces a time or spatial domain representation, whereas a discrete Fourier.
Antenna theory - Antenna theory Antenna theory and antenna design is of interest to anyone who receives or transmits radio signals. An antenna is an arrangement of electrical conductorss that can transmit and/or receive electromagnetic energy. Antenna theory is grounded in Maxwell's equations. Antennas may be omnidirectional, sending or receiving from all directions equally, or they may be directional and favor one direction over others. Antenna theory is concerned with understanding how the size and shape of antennas affects directionality, antenna gain and other properties. Table of contents showTocToggle("show","hide") 1 Antenna types based on waves are generated 1.1 Electric antenna 1.2 Magnetic antenna 2 Directionality in antennas 2.3 Directional antenna 3 See also Antenna types based on waves are generated Since radio waves are electromagnetic, there are two basically different.
Signal - Signal A signal may be: An abstract element of information, or more exactly usually a flow of information (in either one or several dimensions). See Signal (information theory) In computing, an asynchronous event transmitted between one process and another (in Linux, UNIX and other POSIX-compliant operating systems, and also in several real-time operating system). A means of controlling road vehicles, pedestrians or trains. See Traffic signal, Pedestrian crossing or Railway signal. See also Signal processing, noise (physics). This is a disambiguation page; that is, one that just points to other pages that might otherwise have the same name. If you followed a link here, you might want to go back and fix the link, so that it points to the appropriate page..
Rate distortion theory - Rate distortion theory Rate distortion theory is the branch of information theory addressing the problem of determining the minimal amount of entropy (or information) R that should be communicated over a channel such that the source (input signal) can be reconstructed at the receiver (output signal) with given distortion D. As such, rate distortion theory gives theoretical bounds for how much compression can be achieved using lossy data compression methods. Many of the existing audio, speech, image, and video compression techniques have transforms, quantization, and bit rate allocation procedures that capitalize on the general shape of rate-distortion functions. Rate distortion theory was created by Claude Shannon in his founding work on information theory. Table of contents showTocToggle("show","hide") 1 Introduction 2 Rate-Distortion Functions 2..1 Memoryless (Independent) Gaussian Source 2..2.
Quantization (signal processing) - Quantization (signal processing) In digital signal processing, quantization is the process of approximating a continuous signal by a set of discrete symbols or integer values. In general, a quantization operator can be represented as Q(x) = round(f(x)) where x is a real number, Q(x) an integer, and f(x) is an arbitrary real-valued function that controls the 'quantization law' of the particular coder. For example, in digital telephony, two popular quantization schemes are the 'A-law' and 'µ-law', each mapping an analog signal to an integer value represented by an 8-bit binary number, but each with a different function f. See also: information theory rate distortion theory.
Jamming - control of a battle. A transmitter, tuned to the same frequency as the opponents receiving equipment and with the same type of modulation, can with enough power override any signal at the receiver. The most common types of this form of signal jamming are: Random Noise; Random Pulse; Stepped Tones; Wobbler; Random Keyed Modulated CW; Tone; Rotary; Pulse; Spark; Recorded Sounds; Gulls; and Sweep-through. All of these can be divided into two groups - obvious and subtle. Obvious jamming is easy to detect as it can be heard on the receiving equipment, it is some type of noise such as stepped tones (bagpipes), random-keyed code, pulses, erratically warbling tones, and recorded sounds. The purpose of this type of jamming is to block out reception of transmitted signals and to cause a.
Janez Strnad - thought this was not fair. A researcher should explain to the laity what he is doing and "if they won't support him within such milieu, that is their own concern"). Selected works University textbooks: Janez Strnad, Atlas klasične in moderne fizike (Atlas of classical and modern physics), translation and adaptation of Hans Breuer, dtv-Atlas zur Physik, (Deutscher Taschenbuch Verlag, München 1987, 1988)), DZS, Ljubljana 1993, pp 400. Janez Strnad, Fizika, 1. del, Mehanika, Toplota (Physics, 1st part, Mechanics, Heat), (DZS, Ljubljana 1977, pp 1 - 284. Janez Strnad, Fizika, 2. del, Elektrika, Optika (Physics, 2nd part, Electricity, Optics), (DZS, Ljubljana 1978, pp 285 - 564). Janez Strnad, Fizika, 3. del, Posebna teorija relativnosti, Atomi (Physics, 3rd part, Special Theory of relativity, Atoms), (DZS, Ljubljana 1980, pp 320). Janez Strnad, Fizika, 4..
Jumpstart 3rd-6th Grade - meets Maestro Trumbot[spelling not certain] the head of the All-Winning, All-Robot Courus. Here we find out that Polly wants us to play a particular song for her. However she has organized the chips. The user must reorganize them, when they are correct, the Maestro will play the music for Polly and the student will receaive the Invention/Mission Clue. Second Floor On the second floor there is a staircase leading back to the First Floor, and a tram that takes the rider to the Third Floor. There are two rooms on the Second Floor. Biosphere In the Biosphere, Prof. Spark can grow anything he wants from any part of the world. There are five environments in the Bioshere; a desert, a rain forest, a savana, a mountain range and an ocean. To.
Interdisciplinarity - than others: philosophy, mathematics, business, economics, education, ecology, history, and computer science, among others. Some other, newer fields, such as cybernetics and systems theory, are also highly interdisciplinary. All disciplines have important connections with other disciplines, however. Factors that, arguably, have hindered interdisciplinary work are the traditional divisions that have been established between disciplines and the resulting homogeneity within academic bodies such as departments and specialized journals. Nevertheless, some of the most important interdisciplinary work has been done by people who have a definite "academic home" in one discipline. Here are a few of the most important concepts that are arguably interdisciplinary, thus finding applications in several different fields: Terms with a high degree of interdisciplinarity include: abstraction architecture analogy chaos theory complexity control culture cycle design discipline elegance energy entropy.
Viterbi algorithm - of hidden states (or causes) that result in a sequence of observed events. It is commonly used in information theory, speech recognition and computational linguistics. For example, in speech-to-text speech recognition, the acoustic signal is treated as the observed sequence of events, and a string of text is considered to be the "hidden cause" of the acoustic signal. The Viterbi algorithm finds this hidden cause if it is given the acoustic signal. The algorithm is not general; it makes a number of assumptions. First, both the observed events and hidden events must be in a sequence. This sequence often corresponds to time. Second, these two sequences need to be aligned, and an observed event needs to correspond to exactly one hidden event. Third, computing the most likely hidden sequence up to.
Israeli attack on USS Liberty - the size of the Liberty. All crew members and several Western observers allege that the attack was made deliberately, and reject all these reports as incomplete. They claim a real investigation has never taken place, all previous work being incomplete, mentioning the incident in passing, and designed to exonerate Israel. The survivors claim further that there has been no full congressional hearing, a demand which would probably satisfy them (especially since Liberty stands as the only peacetime attack on a US naval vessel not investigated by Congress[1]). Various theories are presented at times as to why they claim that Israel carried out this action; one theory was that Israel was trying to get the U.S. involved in the conflict on Israel's side, by convincing the U.S. that Egypt was the aggressor..
Hamming distance - Hamming distance In information theory, the Hamming distance is the number of positions in two strings of equal length for which the corresponding elements are different. Put another way, it measures the number of substitutions required to change one into the other. It was named after Richard Hamming. The Hamming distance is used in telecommunication to count the number of flipped bits in a fixed-length binary word, an estimate of error, and so is sometimes called the signal distance. It corresponds to the weight (number of ones) in the XOR of the words, or to the Manhattan distance between two vertices in an n-dimensional hypercube, where n is the length of the words. Some examples: The Hamming distance between 1011101 and 1001001 is 2. The Hamming distance between 2143896.
Harry Nyquist - 1889 - April 4, 1976) was an important contributor to information theory. He was born in Nilsby, Sweden. He emigrated to the USA in 1907 and entered the University of North Dakota in 1912. He received a Ph.D. in physics at Yale University in 1917. He worked at AT&T from 1917 to 1934, then moved to Bell Telephone Laboratories. As an engineer at Bell Laboratories, he did important work on thermal noise ("Johnson-Nyquist noise") and the stability of feedback amplifiers. His early theoretical work on determining the bandwidth requirements for transmitting information, as published in "Certain factors affecting telegraph speed" (Bell System Technical Journal, 3, 324-346, 1924), laid the foundations for later advances by Claude Shannon, which led to the development of information theory. In 1927 Nyquist determined that an analog.
Heaviside step function - whose value is zero for negative inputs and one elsewhere: The function is used in the mathematics of signal processing to represent a signal that switches on at a specified time and stays switched on indefinitely. The Heaviside function is the integral of the Dirac delta function. The value of H(0) is of very little importance, since the function is often used within an integral. Some writers give H(0) = 0, some H(0) = 1. H(0) = 0.5 is often used, since it maximizes the symmetry of the function. This makes the definition: The question of the Fourier transform of H is an interesting example for the theory of distributions. It is often stated that it is 1/x, up to a normalizing constant. But near x=0 that cannot be justified: the.
Hydrogen atom - momentum quantum number l is denoted in each column, using the usual spectroscopic letter code ("s" means l=0; "p": l=1; "d": l=2). The main quantum number n (=1,2,3,...) is marked to the right of each row. For all pictures the magnetic quantum number m has been set to 0, and the cross-sectional plane is the x-z plane (z is the vertical axis). The probability density in threedimensional space is obtained by rotating the one shown here around the z-axis. The "ground state", i.e. the state of lowest energy, in which the electron is usually found, is the first one, the "1s" state (n=1,l=0). Click to view an image with more orbitals (up to higher numbers n and l). Note the number of black lines that occur in each but the first.
