Johnson-Nyquist noise - Johnson-Nyquist noise Johnson-Nyquist noise (sometimes only "Nyquist noise") is the equilibrium fluctuations of the electric current inside an electrical conductor, which happen without any applied voltage, due to the random thermal motion of the charge carriers (the electrons). It is to be distinguished from Shot noise, which describes the additional current fluctuations that occur when a voltage is applied and a macroscopic current starts to flow. The strength of Nyquist noise is related to the temperature and the resistance of the conductor. See: Harry Nyquist, J. Johnson J. Johnson, "Thermal Agitation of Electricity in Conductors", Phys. Rev. 32, 97 (1928) -- the experiment H. Nyquist, "Thermal Agitation of Electric Charge in Conductors", Phys. Rev. 32, 110 (1928) -- the theory.
Harry Nyquist - Harry Nyquist Harry Nyquist (February 7, 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.
Shot noise - Shot noise Shot noise refers to the random fluctuations of the electric current in an electrical conductor, which are caused by the fact that the current is carried by discrete charges (electrons). The strength of this noise increases for growing magnitude of the average current flowing through the conductor. Shot noise is to be distinguished from current fluctuations in equilibrium, which happen without any applied voltage and without any average current flowing. These equilibrium current fluctuations are known as Johnson-Nyquist noise. Shot noise is important in electronics, telecommunication, and for fundamental physics. The strength of the current fluctuations can be expressed by giving the variance of the current, <(I-)>2, where is the average ("macroscopic") current. However, the value measured in this way depends on the frequency.
Noise (physics) - Noise (physics) In science, and especially in physics and telecommunication, noise is random fluctuations and the addition of external factors to the stream of target information (signal) being received at a detector. More specifically, in physics, the term noise has the following meanings: 1. An undesired disturbance within the frequency band of interest; the summation of unwanted or disturbing energy introduced into a communications system from man-made and natural sources. 2. A disturbance that affects a signal and that may distort the information carried by the signal. 3. Random variations of one or more characteristics of any entity such as voltage, current, or data. 4. A random signal of known statistical properties of amplitude, distribution, and spectral density. 5. Loosely, any disturbance tending to interfere with.
Timeline of thermodynamics, statistical mechanics, and random processes - equilbrium will be to counteract the perturbation 1893 - Wilhelm Wien discovers the displacement law for a blackbody's maximum specific intensity 1905 - Albert Einstein mathematically analyzes the Brownian motion 1906 - Walther Nernst presents a formulation of the third law of thermodynamics 1910 - Albert Einstein and Marian Smoluchowski find the Einstein-Smoluchowski formula for the attenuation coefficient due to density fluctuations in a gas 1916 - Sydney Chapman and David Enskog systematically develop a kinetic theory of gases 1919 - James Jeans discovers that the dynamical constants of motion determine the distribution function for a system of particles 1920 - Meghnad Saha states his ionization equation 1923 - Peter Debye and Erich Huckel publish a statistical treatment of the dissociation of electrolytes 1928 - J.B. Johnson discovers Johnson noise in.
List of physics topics F-L - Geomagnetically Trapped Radiation Invariant Inverse-square law Iridescence Isentropic process Ising model Isolated singularity Isospin Isotopic spin J Jacobi, Carl Gustav Jakob Jacobian Jaynes, Edwin Jellium Jensen, J. Hans D Johnson-Nyquist noise Josephson effect Josephson, Brian David Joule, James Prescott Joule-Thompson effect Joule's law Journal of Physics K Kaluza-Klein theory Kamerlingh-Onnes, Heike Kapitsa, Pyotr Leonidovich Kastler, Alfred Kelvin Kelvin-Helmholtz instability Kendall, Henry W Kendall, Henry W Kennedy-Thorndike experiment Kepler, Johannes Kerr metric Ketterle, Wolfgang Kilby, Jack S Kinematics Kinetic energy Kinetic theory Kirchhoff's Laws Kirchhoff, Gustav Kirkendall effect Klein paradox Knife-edge effect Koshiba, Masatoshi Kroemer, Herbert Kusch, Polycarp L LADAR Ladder operator Langevin, Paul Langevin equation Lagrange, Joseph Louis Lagrange bracket Lagrange multiplier Lagrangian Lagrangian mechanics Lagrangian point Lamb, Willis Eugene Lamb-Retheford shift Lambert, Johann Heinrich Laminar flow Landau, Lev Davidovich Lande.
Thermal noise - Thermal noise In telecommunication or other systems, thermal noise (Johnson noise) is the noise generated by thermal agitation of electrons in a conductor. The noise power, P , in watts, is given by P = kT Δf , where k is Boltzmann's constant in joules per kelvin, T is the conductor temperature in kelvins, and Δf is the bandwidth in hertz. Thermal noise power, per hertz, is equal throughout the frequency spectrum, depending only on k and T . For the general case, the above definition may be held to apply to charge carriers in any type of conducting medium. Source: from Federal Standard 1037C and from MIL-STD-188 Thermal noise is intrinsic to all resistors and is not a sign of poor design or manufacture, although resistors.
Nyquist-Shannon sampling theorem - Nyquist-Shannon sampling theorem The Nyquist-Shannon sampling theorem is a fundamental tenet in the field of information theory, in particular telecommunications. The theorem states that, when converting from an analog signal to digital (or otherwise sampling a signal at discrete intervals), the sampling frequency must be greater than twice the highest frequency of the input signal in order to be able to reconstruct the original perfectly from the sampled version. If the sampling frequency is less than this limit, then frequencies in the original signal that are above half the sampling rate will be "aliased" and will appear in the resulting signal as lower frequencies. Therefore, an analog low-pass filter is typically applied before sampling to ensure that no components with frequencies greater than half the sample.
John F. Kennedy assassination - wounds while riding in an open-top automobile. Texas Governor John B Connally was also severely injured in the same assassination attempt. Later that afternoon, U.S. Vice President Lyndon B. Johnson was sworn in as the 36th President of the United States aboard Air Force One. Table of contents showTocToggle("show","hide") 1 The Assassination 1.1 A nation mourns 2 List of Witnesses to the Assassination 3 Investigations into the assassination 4 Security failures 5 The Zapruder Film 6 Conspiracy Theories 7 KGB disinformation 8 BBC 'Correspondent' programme in 2003 9 External Links The Assassination At 11:40 AM (U.S. Central standard time), President Kennedy, his wife Jacqueline, and the rest of the presidential entourage arrived at Love Field, then Dallas' only airport, in Air Force One. The original itinerary was for the president to.
Information theory - 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 theory concerns itself with content through lossy compression of messages subject to a fidelity criterion. These two wings of information theory are joined.
It Takes a Nation of Millions to Hold Us Back - Top R&B/Hip Hop Albums chart, and #42 on the Billboard 200 chart. Table of contents showTocToggle("show","hide") 1 Track listing 2 Personnel 3 Charting singles Track listing "Countdown to Armageddon" (Ridenhour/Sadler/Shocklee) "Bring the Noise" (Ridenhour/Sadler/Shocklee) "Don't Believe the Hype" (Drayton/Ridenhour/Sadler/Shocklee) "Cold Lampin' With Flavor" (Sadler/Shocklee) "Terminator X to the Edge of Panic" (Drayton/Ridenhour/Rodgers) "Mind Terrorist" (Ridenhour/Sadler/Shocklee) "Louder Than a Bomb" (Ridenhour/Sadler/Shocklee) "Caught, Can We Get a Witness" (Ridenhour/Sadler/Shocklee) "Show 'Em Whatcha Got" (Ridenhour/Sadler/Shocklee) "She Watch Channel Zero?!" (Drayton/Griffin/Ridenhour/Sadler/Shocklee) "Night of the Living Baseheads" (Ridenhour/Sadler/Shocklee) "Black Steel in the Hour of Chaos" (Public Enemy) "Security of the First World" (Ridenhour/Sadler/Shocklee) "Rebel Without a Pause" (Ridenhour/Rodgers/Sadler/Shocklee) "Prophets of Rage" (Drayton/Ridenhour/Sadler/Shocklee) "Party for Your Right to Fight" (Ridenhour/Sadler/Shocklee) Personnel Professor Griff - Vocals Chuck D. - Vocals Steven Ett - Mixing Fab 5 Freddy -.
Vocoder - single fundamental frequency, the vocal system adds in a number of resonant frequencies that add character and quality to the voice, known as the formant. Without capturing these additional qualities, the vocoder will never sound "real". In order to address this, most vocoder systems use what are effectively a number of vocoders, all tuned to different frequencies (using band-pass filters). The various values of these filters are stored not as the raw numbers, which is all based on the original fundamental frequency, but as a series of modifications to that fundamental needed to modify it into the signal seen in that filter. During playback these settings are sent back into the filters and then added together, modified with the knowledge that speech typically varies between these frequencies in a fairly linear.
History of the United States (1918-1945) - of food. US President Woodrow Wilson campaigned for the US to join the new League of Nations without success, as the mood of the nation favored a return to isolationism. The Roaring 20s In the U.S. presidential election, 1920 the Republican Party returned to the White House with the election of Warren G. Harding, who promised a "return to normalcy" after the traumatic years of World War I. During most of the 1920s the United States enjoyed a period of unbalanced prosperity: prices for agricultural commodities and wages fell at the end of the war while new industries (radio, movies, automobiles, and chemicals) flourished. The unevenness was also geographic: the standard of living in rural areas fell increasingly behind that of urban and suburban areas which saw dramatic improvements in housing.
Glen Rice - Miami's top option and a recognized scorer in the league. In only Miami's fourth season, 1991-92, he lead Miami to the NBA playoffs, where they were swept by Michael Jordan and the 67-15 Chicago Bulls. Rice lead the Heat back to the playoffs in 1993-94, but the Heat made little noise. In 1995 in a blockbuster trade, Rice was sent with center Matt Geiger to the Charlotte Hornets for all-star center Alonzo Mourning. Rice immediately teamed with point guard Kenny Anderson and power forward Larry Johnson to form one of the top trios in the league in 1995-96. He became an undisputed star and one of the top scorers in the league. In 1996-97, now teamed with power forward Anthony Mason, Rice had perhaps the best season of his career, finishing.
Grammy Award for Best Rock Instrumental Performance - Art Neville for "SRV Shuffle" Grammy Awards of 1996: Allman Brothers Band for "Jessica" Grammy Awards of 1995: Pink Floyd for "Marooned" Grammy Awards of 1994: Zappa's Universe Rock Group featuring Steve Vai for "Sofa" Grammy Awards of 1993: Stevie Ray Vaughan & Double Trouble for "Little Wing" Grammy Awards of 1992: Eric Johnson for "Cliffs Of Dover" Grammy Awards of 1991: Vaughan Brothers for "D/FW" Grammy Awards of 1990: Jeff Beck for Jeff Beck's Guitar Shop With Terry Bozzio & Tony Hymes 1980s Grammy Awards of 1989: Carlos Santana for Blues For Salvador Grammy Awards of 1988: Frank Zappa for Jazz From Hell Grammy Awards of 1987: Art Of Noise featuring Duane Eddy for "Peter Gunn" Grammy Awards of 1986: Jeff Beck for "Escape" Grammy Awards of 1985: Yes for.
Grammy Awards of 1987 - Tutu performed by Miles Davis Best Album Notes Andrew Sarris, Frank Conroy, Gary Giddins, Jonathan Schwartz, Murray Kempton, Stephen Holden & Wilfrid Sheed for The Voice - The Columbia Years 1943-1952 performed by Frank Sinatra Polka Best Polka Recording Eddie Blazonczyk for Another Polka Celebration Jimmy Sturr for I Remember Warsaw Pop Best Female Pop Vocal Performance Barbra Streisand for The Broadway Album Best Male Pop Vocal Performance Steve Winwood for "Higher Love" Best Pop Performance by a Duo or Group with Vocal Dionne Warwick, Elton John, Gladys Knight & Stevie Wonder for "That's What Friends Are For" Best Pop Instrumental Performance Harold Faltermeyer & Steve Stevens for "Top Gun Anthem" Production and engineering Best Engineered Recording, Non-Classical Jason Corsaro & Tom Lord-Alge (engineers) for "Back in the High Life" Producer.
Filter design - response (FIR) Sample rate Unless the sample rate is fixed by some outside constraint, selecting a suitable sample rate is an important design decision. A high rate will require more in terms of computational resources, but less in terms of anti-aliasing filters. Interference and beating with other signals in the system may also be an issue. Anti-aliasing For any digital filter design, it is crucial to analyze and avoid aliasing effects. Often, this is done by adding analog anti-aliasing filters at the input and output, thus avoiding any frequency component above the Nyquist frequency. The complexity (i.e., steepness) of such filters depends on the required signal to noise ratio and the ratio between the sampling rate and the highest frequency of the signal. IIR IIR filters are the digital equivalent of.
Electronic amplifier - this by taking power from a power supply and shaping the output to match the input signal. This process invariably introduces some noise and distortion into the signal, and the process cannot be 100% efficient - amplifiers will always produce some waste heat. An idealised amplifer can be said to be "a piece of wire with gain", the output is an exact replica of the input, only larger. Different designs of amplifier are used for different types of applications and signals. We can broadly divide amplifiers into three categories - small signal amplifiers, low frequency power amplifiers and RF power amplifiers. Each of these calls for a slightly different design approach, mainly because of the physical limitations of the components used to implement the amplifier, and the efficiencies that can be.
Dennis Rodman - cm) in one year late in his teenage years. After a stint in junior college, he played for Southeastern Oklahoma State, a Division II school. However, the Detroit Pistons took sufficient notice of him to draft him in the second round in 1986. At that time, the Pistons were an up-and-coming team led by Isiah Thomas at point guard, Joe Dumars at shooting guard, and Bill Laimbeer at center. They had notable role players in Adrian Dantley, Vinnie Johnson, John Salley, and Rick Mahorn. Rodman's intensity was a perfect fit for a team known for its rough style of play and tenacious defense. The Pistons were knocked out of the playoffs in 1987 by their nemesis Boston Celtics, although Rodman did a decent job of guarding their star player, Larry Bird..
1938 in music - Reverie" by Larry Clinton "Thanks for the Memory" by Shep Fields "Ti-Pi-Tin" by Hoarce Heidt Published popular songs "And The Angels Sing" w. Johnny Mercer m. Ziggy Elman "At Long Last Love" w.m. Cole Porter "At The Roxy Music Hall" w. Lorenz Hart m. Richard Rodgers "Back Bay Shuffle" m. Artie Shaw & Teddy McRae "Big Noise From Winnetka" w.m. Ray Bauduc, Bob Crosby, Bob Haggart & Gil Rodin "The Biggest Aspidistra In The World" w.m. Thomas Connor, W. G. Haines & James S. Hancock "Bolero At The Savoy" w.m. Charles Carpenter, Gene Krupa & James Mundy "Boom!" w.m. E. Ray Goetz & Charles Trenet "Boomps-A-Daisy" w.m. Annette Mills "Boum" w.m. Charles Trenet "Change Partners" w.m. Irving Berlin "Cherokee" m. Ray Noble "Cinderella, Stay In My Arms" w. Jimmy Kennedy m. Michael Carr "Colorado Sunset" Gilbert, Conrad "Dearest Love" w.m. Noël Coward "Deep In A Dream" w..
