Generators info

In computing, specifically Linux, a raw device is a special kind of block device file that allows accessing a storage device such as a hard drive directly, bypassing the operating system’s caches and buffers (although the hardware caches might still be used). Applications like a Database management system can use raw devices directly, enabling them to manage how data is cached, rather than deferring this task to the operating system.

On Linux raw devices are now obsolete and have been removed from the kernel, because the O_DIRECT flag can be used instead.[1] Instead of accessing a special raw device file, the application simply accesses a file with the O_DIRECT flag enabled, and caching will be disabled.

The terms pulse rifle and pulse pistol refer to various science fiction weapons.

• The M41A “Pulse Rifle” is an assault rifle in the motion picture Aliens that uses 10 mm caseless ammunition.
• There has been a statement that a pulse rifle is a bullet-firing rifle where the cartridge’s primer is set off electronically and not by a firing hammer. This is sometimes used in conjunction with the M41 “Pulse Rifle” above.
• The Overwatch Standard Issue Pulse Rifle is an assault rifle-type raygun in the computer game Half-Life 2. It is the general infantry weapon of the Combine Overwatch
• In the fictional Warhammer 40,000 universe, the pulse rifle and pulse pistol are standard infantry weapons for the Tau race.
• “Pulse rifle” and “pulse pistol” are often used to mean a raygun.
• The pulse rifle and pulse pistol are the primary weapons used by the Peacekeepers and others on the television show Farscape.
• The pulse rifle is a weapon in Blade Runner (video game)

See also

• Plasma rifle
• Science fiction weapon

A power-on reset (PoR) generator is a microcontroller or microprocessor peripheral that generates a reset signal when power is applied to the device. It ensures that the device starts operating in a known state.

In VLSI devices, the power-on reset (PoR) is an electronic device incorporated into the integrated circuit that detects the power applied to the chip and generates a reset impulse that goes to the entire circuit placing it into a known state.
A simple PoR is composed by a RC device that charges with the rising of the supply voltage. A schmitt trigger is used so that the rising charged voltage of the RC network generates an impulse. This impulse is generated based on the two threshold voltages of the schmitt trigger. When the input voltage at the schmitt trigger coming from the RC network reaches the first threshold voltage the output of the schmitt trigger switches so that it generates the first edge of the input. The charging of the RC network should be long enough so that the PoR can reset all the internal circuits before the charging voltage reaches the other threshold voltage of the schmitt trigger and the output to switch back.

One of the issues with using RC network to generate PoR pulse is the sensitivity of the R and C values to the power-supply ramp characteristics. When the power supply ramp is rapid, the R and C values can be calculated so that the time to reach the switching threshold of the schmitt trigger is enough to apply a long enough reset pulse. When the power supply ramp itself is slow, the RC network tends to get charged up along with the power-supply ramp up. So when the input schmitt stage is all powered up and ready, the input voltage from the RC network would already have crossed the schmitt trigger point. This means that there might not be a reset pulse supplied to the core of the VLSI…

Fantasy name generators are programs that use a computer algorithm to create a fantasy name at random probability, usually for use in a role-playing game. They have been around since at least 1994. Early fantasy name generators often generated nonsense, creating names such as “Rsi’sskoo” or “Gbbtti”. Modern fantasy name generators are typically better at creating usable names.

In electronics (specifically, signal processing), half time usually refers to the time it takes for the amplitude of a pulse to drop from 100% to 50% of its peak value.

<math>t_{half}\;=\;t_2\;-\;t_1\,\!</math>

Jim Sonzero is a music video and film director. He co-directed Mariah Carey’s “Can’t Let Go”. His feature length directorial debut was Pulse, a horror movie starring Kristen Bell.

PODi the Digital Printing Initiative. An organisation that helps set strategic direction in the digital print industry. Members include IBM, Kodak, Xerox, Canon and Hewlett-Packard.

External links

• PODi home page

E Pluribus Unicorn is a collection of fantasy and science fiction stories by Theodore Sturgeon, published in 1953 by Abelard.

Contents

• “Essay on Sturgeon” by Groff Conklin
• “The Silken-Swift”
• “The Professor’s Teddy-Bear”
• “Bianca’s Hands”
• “Saucer of Loneliness”
• “The World Well Lost”
• “It Wasn’t Syzygy”
• “The Music”
• “Scars”
• “Fluffy”
• “The Sex Opposite”
• “Die, Maestro, Die!”
• “Cellmate”
• “A Way of Thinking”

1. REDIRECTList of Star Wars weapons#Destructive Electro-Magnetic Pulse 2 Gun

The Condor Trilogy () is a trilogy of three wuxia fiction novels by Jinyong. The trilogy began with the fall of Jin Dynasty and Song Dynasty and the rise of Mongolian Empire. The story ended more than a hundred years later with the establishment of Ming dynasty. The characters in the trilogy played significant roles in the rise and fall of these nations.

Although the English name of the trilogy is “The Condor Trilogy”, it is most likely a mistranslation, as the characters in the first two novels are associated with eagles, not condors (the word 鵰 in the Chinese titles literally meaning eagle, not condor).

The books in the trilogy are:

• The Legend of the Condor Heroes (射鵰英雄傳) (1957)
• The Return of the Condor Heroes (神鵰俠侶) (1959)
• The Heavenly Sword and the Dragon Saber (倚天屠龍記) (1961)

See also

• List of characters in Condor Trilogy

A Triplexor is an optical component made of silica with a silicon wavefront which utilize the Mach-Zehnder interferometry design to tweak fiber-bragg grating.

A Triplexor is also a short name for a Triplex Alternator. Often found as a 3 input, 2 or 3 output, solid state alternator that equalizes output load operational time. A load select switch can permit the Triplexor to be used as a duplex alternator until system expansion requires Triplex operation.

In classical conditioning, second-order conditioning or higher-order conditioning is a form of learning in which a stimulus is first made meaningful or consequential for an organism through an initial step of learning, and then that stimulus is used as a basis for learning about some new stimulus. For example, an animal might first learn to associate a bell with food (first-order conditioning), but then learn to associate a light with the bell (second-order conditioning). Third order conditioning can then follow with a further stimulus being added and the response elicited can be weak. Also known as shaping behavior. Often related to B. F. Skinner’s studies with pigeons. Another example would be Skinner first condition a pigeon to walk up to a ball, then conditioning it to touch the ball with its beak. He would thus use a second-order to shape the animal’s behavior. Often used with biological predispositions.

A Lagged Fibonacci generator (LFG) is an example of a pseudorandom number generator. This class of random number generator is aimed at being an improvement on the ’standard’ linear congruential generator. These are based on a generalisation of the Fibonacci sequence.

The Fibonacci sequence may be described by the recurrence relation:

<math>S_n = S_{n-1} + S_{n-2}</math>

Hence, the new term is the sum of the last two terms in the sequence. This can be generalised to the sequence:

<math>S_n \equiv S_{n-j} \star S_{n-k} \pmod{m}, 0 < j < k</math>

In which case, the new term is some combination of any two previous terms. m is usually a power of 2 (m = 2^M), often 2³² or 2⁶⁴. The <math>\star</math> operator denotes a general binary operation. This may be either addition, subtraction, multiplication, or the bitwise arithmetic exclusive-or operator (XOR). The theory of this type of generator is rather complex, and it may not be sufficient simply to choose random values for j and k. These generators also tend to be very sensitive to initialisation.

Generators of this type employ k words of state (they ‘remember’ the last k values).

If the operation used is addition, then the generator is described as an Additive Lagged Fibonacci Generator or ALFG, if multiplication is used, it is a Multiplicative Lagged Fibonacci Generator or MLFG, and if the XOR operation is used, it is called a Two-tap Generalised Feedback Shift Register or GFSR. The Mersenne twister algorithm is a variation on a GFSR.

Properties of Lagged Fibonacci Generators

Lagged Fibonacci generators have a maximum period of (2^k - 1)*2^M-1 if addition or subtraction is used, and (2^k-1) if exclusive-or operations are used to combine the previous values. If, on the other hand, multiplication is used, the maximum period is (2^k - 1)*2^M-3, or 1/4 of period of the additive case. It is important that M be greater than 100 for the additive case.

For the generator to achieve this maximum period, the polynomial:

y = x^k + x^j + 1

must be primitive over the integers mod 2. Values of j and k satisfying this constraint have been published in the literature. Popular pairs are:

{j = 7, k = 10}, {j = 5, k = 17}, {j = 24, k = 55}, {j = 65, k = 71}, {j = 128, k = 159} [1], {j = 6, k = 31}, {j = 31, k = 63}, {j = 97, k = 127}, {j = 353, k = 521}, {j = 168, k = 521}, {j = 334, k = 607}, {j = 273, k = 607}, {j = 418, k = 1279} [2]

Another list of possible values for j and k is on page 28 of volume 2 of The Art of Computer Programming; the values listed above are in bold face:

(1,2), (1,3), (2,3), (1,4), (3,4), (2,5), (3,5), (1,6), (5,6), (1,7), (6,7), (3,7), (4,7), (4,9), (5,9), (3,10), (7,10), (2,11), (9,11), (1,15), (14,15), (4,15), (11,15), (7,15), (8,15), (3,17), (14,17), (5,17), (12,17), (6,17), (11,17), (7,18), (11,18), (3,20), (17,20), (2,21), (19,21), (1,22), (21,22), (5,23), (18,23), (9,23), (14,23), (3,25), (22,25), (7,25), (18,25), (3,28), (25,28), (9,28), (19,28), (13,28), (15,28), (2,29), (27,29), (3,31), (28,31), (6,31), (25,31), (7,31), (24,31), (13,31), (18,31), (13,33), (20,33), (2,35), (33,35), (11,36), (25,36), (4,39), (35,39), (8,39), (31,39), (14,39), (25,39), (3,41), (38,41), (20,41), (21,41), (5,47), (42,47), (14,47), (33,47), (20,47), (27,47), (21,47), (26,47), (9,49), (40,49), (12,49), (37,49), (15,49), (34,49), (22,49), (27,49), (3,52), (49,52), (19,52), (33,52), (21,52), (31,52), (24,55), (31,55), (7,57), (50,57), (22,57), (35,57), (19,58), (39,58), (1,60), (59,60), (11,60), (49,60), (1,63), (62,63), (5,63), (58,63), (31,63), (32,63), (18,65), (47,65), (32,65), (33,65), (9,68), (59,68), (33,68), (35,68), (6,71), (65,71), (9,71), (62,71), (18,71), (53,71), (20,71), (51,71), (35,71), (36,71), (25,73), (48,73), (28,73), (45,73), (31,73), (42,73), (9,79), (70,79), (19,79), (60,79), (4,81), (77,81), (16,81), (65,81), (35,81), (46,81), (13,84), (71,84), (13,87), (74,87), (38,89), (51,89), (2,93), (91,93), (21,94), (73,94), (11,95), (84,95), (17,95), (78,95), (6,97), (91,97), (12,97), (85,97), (33,97), (64,97), (34,97), (63,97), (11,98), (87,98), (27,98), (71,98)

Note that the smaller number have short periods (only a few “random” numbers are generated before the first “random” number is repeated and the sequence restarts).

It is required that at least one of the first k values chosen to initialise the generator be odd.

It has been suggested that good ratios between j and k are approximately the golden ratio.

Problems with LFGs

The initialisation of LFGs is a very complex problem; any maximum period LFG has a large number of possible cycles, all different. Choosing a cycle is possible, but methods for doing this may endanger the randomness of subsequent outputs. Secondly, the output of LFGs is very sensitive to initial conditions, and statistical defects may appear initially but also periodically in the output sequence unless extreme care is taken. Another potential problem with LFGs is that the mathematical theory behind them is incomplete, making it necessary to rely on statistical tests rather than theoretical performance. These reasons, combined with the existence of the free and very high-quality Mersenne twister algorithm tend to make ‘home-brewed’ implementations of LFGs less than desirable in the presence of superior alternatives.

Usage

• Freeciv uses a lagged Fibonacci generator with {j = 24, k = 55} for its random number generator.
• The Boost library includes an implementation of a lagged Fibonacci generator.
• MATLAB uses a {j=??, k = 32} generator for its rand() function (info here).
• The Oracle Database implements this generator in its DBMS_RANDOM package (available in Oracle 8 and newer versions).

See also

• Linear congruential generator
• Mersenne twister
• FISH (cipher)
• Pike
• VIC cipher

In computer science, Atropos is a real-time scheduling algorithm developed at Cambridge University. It combines the Earliest Deadline First algorithm with a best effort scheduler to make use of slack time, while exercising strict admission control.

Vibrational energy relaxation, or vibrational population relaxation, is a process in which the population distribution of molecules in vibrationally quantum states of high energy level caused by an external perturbation returns to the Maxwell-Boltzmann distribution.

In solution, the process proceeds with intra- and intermolecular energy transfer. The excess energy of the excited vibrational mode is transferred to the kinetic modes in the same molecule or to the surrounding molecules. Through this process, the initially excited vibrational mode moves to a vibrational state of a lower energy. The relaxation is called the longitudinal relaxation, and the time constant of the relaxation is called the longitudinal relaxation time, or T₁.

Vibrational energy relaxation has been studied with time-resolved spectroscopy. By the excitation of the pump pulse, the population distribution of the vibrationally excited state is made by infrared absorption or a Raman process when the molecule is in the electronic ground state. In addition, by the electronic transition, the molecule often moves to the vibrationally excited state of the electronic excited state. The process of the energy relaxation from these vibrationally excited states can be observed with the probe pulse, which is delayed from the pump pulse.

A Barker code is a sequence of N values of +1 and −1,

<math>a_j</math> for <math>j = 1, \cdot\cdot\cdot, N</math>

such that

<math>|\sum_{j=1}^{N-v} a_j a_{j+v}| \le 1\,</math>

for all <math>1 \le v < N</math>.

Here is a table of all known Barker codes, where negations and reversals of the codes have been omitted:

Barker codes of length 11 and 13 are used in direct-sequence spread spectrum and Pulse Compression Radar systems because of their low autocorrelation properties.

Barker codes utilize biphase modulation; that is, the change of phase in the carrier wave is 180 degrees.

See also

• Pseudorandom number sequence

References

• Barker Code — Mathworld

ASG may refer to:

• ASG (band)
• Abstract semantic graph
• Abu Sayyaf Group
• Adaptive Services Grid
• Airsoft gun
• All Saints Greek Orthodox Grammar School, or All Saints Grammar
• All-star game
• Allen Systems Group, Inc., a Naples, Florida based worldwide software company
• Alsager railway station’s national rail code
• Alternating Step Generator, a cryptographically secure pseudorandom number generator
• Associated Student Government, of Texas State University in San Marcos, Texas
• Australasian Seabird Group, a special interest group of Birds Australia
• Australian Standard Garratt, a WWII-era Australian steam-engine locomotive
• Austria Switzerland Germany, a geographic region used by companies
• Labour and Social Justice Party (Arbeit & soziale Gerechtigkeit)

This list contains an overview of coating techniques for Thin-film deposition, found in the field of materials science. The techniques can be classified in various ways.

Chemical vapor deposition techniques

• Metalorganic vapour phase epitaxy

Physical vapor deposition techniques

• arc-PVD
• Cathodic Arc Deposition
• EBPVD
• Pulsed laser deposition
• Sputter deposition

Other techniques

• Anodising
• Bead
• Curtain
• EB-ion implantation
  
• Electroplating
• Enamel
• Evaporative deposition
• Extrusion
• High velocity oxygen fuel
• Hydrothermal treatment
• Ion implantation
• Ion plating
• Ion beam assisted deposition (IBAD)
• IBED
• Laser alloying
• Liquid phase epitaxy
• Mist deposition
• Magnetron sputtering
• Molecular beam epitaxy
• Pack cementation
• Plasma electrolytic oxidation
• Plasma spraying
• Slurry technique
• Slide Bead
• Sol-gel
• Sputter ion plating
• Wire arc spraying
• Aerosol jet deposition

Source

• Titanium and titanium alloys, edited by C. Leyens and M. Peters, Wiley-VCH, ISBN 3-527-30534-3, table 6.2: overview of several coating systems and fabriction processes for titanium alloys and titanium aluminides (amended)

spin-coating

A sex object could be either:

• an instance of sexual objectification
• a sex symbol
• a device used in sexual activity (e.g. condom)
• a device used to simulate sex (e.g. blow up doll or dildo), also known as a sex toy
• someone’s goal for “scoring” with
• a prostitute
• a pornographic actor
• In fiction, the use of an attractive woman as a distraction (a plot device)
• a 1986 song by Kraftwerk from their album “Electric Café”

Seventh Sanctum (sometimes just The Sanctum) is a website run by Steven Savage (also known as XWayfarer, or simply X). It is a collection of random generators or randomizers and name generators that create random names, items, and even full descriptions of characters. There are generators for everything from spells and pirate ship names, to entire story plots and characters. Many of the generators are oriented towards science fiction, fantasy and anime, and are directed towards artists, writers, and role-playing gamers. It is one of the largest, if not the largest, single collections of random generation tools on the Internet.

As an interesting note, Wikipedia is mentioned a number of times and has a number of links attached.

Writer’s Digest named Seventh Sanctum one of the 101 Best Websites for Writers for 2006. [1]

History of the Website

1999 - Site created as subsite of domain. Incorporated past JavaScript generator for Superhero Names, and one for anime attacks. Initially spawned after commentary that attacks in anime often sounded randomly generated. Site expanded continuously.

2000-2001: The site moved from JavaScript to PHP.

2004 - Site moved to top-level of domain.

2005 - First random contest started.

Generators

There are over a hundred and forty generators which fall into the following seventeen categories. There are also examples from each category.

• Anime/Manga - including “Catgirl Generator” and “Battle Aura Generator”
• Art - including “Sword Generator” and “Dragon Description Generator”
• Beings - including “Alien Race Generator” and “Legendary Creature Generator”
• Characters - including “Deity Generator” and “Super Ninja Generator”
• Combat - including “Fantasy Military Unit Generator” and “Wrestling Move Generator”
• Darkness/Evil - including “Vampire Namer” and “Dark Ritual Generator”
• Equipment - including “Quest Item Generator” and “Currency Generator”
• Humour - including “Wacky Class Generator” and “Evil Animal Minion Generator”
• Magic - including “Magic Item Generator” and “Outer Plane Generator”
• Media/Fandom - including “Crossover Generator” and “Digimon Generator”
• Names - including “Weird Name Generator” and “Greek Namer”
• Organizations - including “Government Title Generator” and “Sentai Team Name Generator”
• Setting - including “Landscape Generator” and “Tavern Generator”
• Superheroes/Sentai - including “Silly Superhero Name Generator” and “Sentai Story Generator”
• Skills/Abilities/Traits - including “Mood Generator” and “Anime Power Generator”
• Technology - including “IT Department Generator” and “Space Phenomena Generator”
• Writing - including “Quick Story Idea Generator” and “What-if-inator”

Community

Part of the Sanctum, as it is known to users, centres on the forum (Seventh Sanctum Sector), where users of the generators gather to talk. Most of the users are of a creative bent, be they poets, writers or artists. A great deal of users are also players of role-playing games.

The forum even has a running joke, and refers on a semi-regular basis to demonic stuffed felines or DSFs. These are small, cute but evil cats with brilliant green eyes and black or navy blue fur. They supposedly constrict one’s writing ability with the aid of a Writer’s Block.

The forum members are also now engaged in a communal world building project and are creating a planet (named Xothu) from scratch with some standard fantasy races (such as dwarves) but also new races as well, such as lilithians (a highly intelligent and dominating race) and jellicles (a race of cat-like humanoids possessing magical power).

External links

• Seventh Sanctum

The French (SNCF) and Belgian (SNCB) railways use an alert system more or less equal to the British Automatic Warning System (AWS),
called the Répétition du Signal en Cabine (French for “Signal Repetition in Driver’s Cab”).

The signal repetition is done by the crocodile, an electrical contact placed between the rails (in the four-foot or 1.22m way) to provide warnings in the locomotive cab. It is distinctively French, originating on the Chemins de Fer du Nord around 1872, spreading throughout France and penetrating even into Belgium and Luxemburg after 1900. It was intended principally to provide evidence of the alertness of the driver, not to act to control a train automatically. Contact is made with a metallic brush mounted beneath an engine passing over it.

The crocodile is an invention of the engineers Lartigue and Forest. Originally it was placed 100-200 metres in rear of a distant signal, usually a red disc of “deferred stop”.
When recording of cab signals was introduced, the crocodile was moved closer to the signal, often directly opposite it, to reduce the chance of a change of the signal between the time the locomotive passed over the crocodile and when the locomotive actually passed the signal. If a signal changed suddenly to a warning aspect in the face of the driver, it would appear that he had not noticed it and had been surprised, when that was not the case.

The crocodile can send two different pieces of information to the driver, according to the aspect of the corresponding signal:

- the “Répétition Signal Fermé” (which literally means: repetition of closed (=on) signal), corresponding to a warning signal, applies a +20V voltage to the crocodile and sounds a horn in the driver’s cab. Then unless the driver presses a button within 5 seconds, a penalty brake is applied.

- the “Répétition Signal Ouvert” (which literally means: repetition of opened (=off) signal), corresponding to a cleared signal, applies a -20V voltage to the crocodile and sounds a gong in the driver’s cab.

See also

• Train protection system

External links

• Explanation of the Crocodile and the French Automatic Train Control (K.V.B.), in French.

• An introduction to French cab signals and speed recorders

In telecommunications, Asynchronous communication is transmission of data without the use of an external clock signal. Any timing required to recover data from the communication symbols is encoded within the symbols. The most significant aspect of asynchronous communications is variable bit rate, or that the transmitter and receiver clock generators do not have to be exactly synchronized.

Physical layer

In asynchronous serial communication at the physical protocol layer, the data blocks are code words of a certain word length, for example octets (bytes) or ASCII characters, delimited by start bits and stop bits. A variable length space can be inserted between the code words. No bit synchronization signal is required. This is sometimes called character oriented communication. Examples are the RS232C serial standard, and MNP2 and V.2 modems and older.

The opposite is isochronous or synchronous serial communication, where a separate clock signal is transferred. Example of this is the X.21 electrical interface between modem and computer. Alternatively the clock signal may be retrieved from a self-clocking line code method such as 8B/10B encoding used in Firewire and Manchester code used in Ethernet. The clock signal timing may also be retrieved from a bit synchronization bit pattern in the beginning of large data blocks or data frames, see below. Other examples of synchronous serial communication are modems using MNP3 or V.5 standards or later.

Non-coherent modulation methods do not require a receiver reference clock signal that is phase synchronized with the sender carrier wave. In this case, the asynchronously transferred blocks (see the definition above) are modulation symbols. The opposite is coherent modulation.

Data link layer and higher

Asynchronous communication at the data link layer or higher protocol layers is known as statistical multiplexing or packet mode communication, for example asynchronous transfer mode (ATM). In this case the asynchronously transferred blocks are called data packets, for example ATM cells. The opposite is circuit switched communication, which provides constant bit rate, for example ISDN and SONET/SDH.

The packets may be encapsulated in a data frame, with a frame synchronization bit sequence indicating the start of the frame, and sometimes also a bit synchronization bit sequence, typically 01010101, for identification of the bit transition times. Note that at the physical layer, this is considered as synchronous serial communication. Examples of packet mode data link protocols that can be/are transferred using synchronous serial communication are the HDLC, Ethernet, PPP and USB protocols.

Application layer

An asynchronous communication service or application does not require constant bit rate. Examples are file transfer, email and the World Wide Web. An example of the opposite, a synchronous communication service, is realtime streaming media, for example IP telephony, IP-TV and video conferencing.

See also

• Asynchronous serial communication
• Asynchronous transfer mode (ATM)
• Plesiochronous
• Plesiochronous Digital Hierarchy (PDH)
• Asynchronous system
• Asynchronous circuit
• Asynchrony
• Anisochronous
• Baud rate

The redshift rocket, envisioned by novelist Karl Schroeder, is a fictional method of spacecraft propulsion.

It is a variant on the Sanger antimatter rocket. One of the key difficulties of harnessing the energy from matter/antimatter collisions is that most of the energy released by them is in the X-ray and gamma ray spectrum. The redshift rocket proposes to use particle beams, such as those produced by ultrafast laser pulses. Both the matter and antimatter would be accelerated to near light speed away from the spacecraft before colliding in the reaction chamber. This would lead to the radiation that reaches the spacecraft being redshifted. If the speed of the particle beams is great enough, the radiation that hits the spacecraft will be of a frequency that can be reflected. Energy absorbed by the spacecraft could be used to help power the particle beams.

But as a result only a very small fraction of the matter/antimatter annihilation reaction would contribute to the propulsion and the main source of thrust would be the particle beams themselves, which must be generated by other means.

A power-on reset (PoR) generator is a microcontroller or microprocessor peripheral that generates a reset signal when power is applied to the device. It ensures that the device starts operating in a known state.

In VLSI devices, the power-on reset (PoR) is an electronic device incorporated into the integrated circuit that detects the power applied to the chip and generates a reset impulse that goes to the entire circuit placing it into a known state.
A simple PoR is composed by a RC device that charges with the rising of the supply voltage. A schmitt trigger is used so that the rising charged voltage of the RC network generates an impulse. This impulse is generated based on the two threshold voltages of the schmitt trigger. When the input voltage at the schmitt trigger coming from the RC network reaches the first threshold voltage the output of the schmitt trigger switches so that it generates the first edge of the input. The charging of the RC network should be long enough so that the PoR can reset all the internal circuits before the charging voltage reaches the other threshold voltage of the schmitt trigger and the output to switch back.

One of the issues with using RC network to generate PoR pulse is the sensitivity of the R and C values to the power-supply ramp characteristics. When the power supply ramp is rapid, the R and C values can be calculated so that the time to reach the switching threshold of the schmitt trigger is enough to apply a long enough reset pulse. When the power supply ramp itself is slow, the RC network tends to get charged up along with the power-supply ramp up. So when the input schmitt stage is all powered up and ready, the input voltage from the RC network would already have crossed the schmitt trigger point. This means that there might not be a reset pulse supplied to the core of the VLSI…

Pulse generators can either be internal circuits or pieces of electronic test equipment used to generate pulses.

Features

Simple pulse generators usually allow control of the pulse repetition rate (frequency), pulse width, delay with respect to an internal or external trigger and the high- and low-voltage levels of the pulses. More-sophisticated pulse generators may allow control over the rise time and fall time of the pulses. Pulse generators may use digital techniques, analog techniques, or a combination of both techniques to form the output pulses. For example, the pulse repetition rate and duration may be digitally controlled but the pulse amplitude and rise and fall times may be determined by analog circuitry in the output stage of the pulse generator. With correct adjustment, pulse generators can also produce a 50% duty cycle square wave. Pulse generators are generally single-channel providing one frequency, delay, width and output. To produce multiple pulses, these simple pulse generators would have to be ganged in series or in parallel.

A new family of pulse generators can produce multiple-channels of independent widths and delays and independent outputs and polarities. Often called digital delay/pulse generators, the newest designs even offer differing repetition rates with each channel. These digital delay generators are useful in synchronizing, delaying, gating and triggering multiple devices usually with respect to one event.

Pulse generators are generally voltage sources, with true current pulse generators being available only from a few suppliers.

Applications

These pulses can then be injected into a device under test and used as a stimulus or clock signal or analyzed as they progress through the device, confirming the proper operation of the device or pinpointing a fault in the device. Pulse generators are also used to drive devices such as switches, lasers and optical components, modulators, intensifiers as well as resistive loads.

The output of a pulse generator may also be used as the modulation signal for a signal generator.

Winona: A woman’s name, is originally from a Sioux nickname for a first-born daughter. <ref>www.native-languages.org</ref>

Places

• Winona, Arizona
• Winona Lake, Indiana
• Winona, Kansas
• Winona, Michigan
• Winona County, Minnesota
  • Winona, Minnesota, the county seat of Winona County
• Winona, Mississippi
  
• Winona, Missouri
• Wynona, Oklahoma
• Winona, Ontario
• Winona, Texas

People

• Wynonna Judd - country singer
• Winona LaDuke - activist
• Winona Ryder - actress

Objects

• In the sci-fi series Farscape, John Crichton nicknamed his personal pulse pistol “Winona” (after Winona Ryder).

See also

• Wenonah

References

<references/>

Project Dolphin is also an ongoing web project to track the number of keystrokes its registered users type. (For example, as of 2006-04-11, the average Project Dolphin user has typed 3,573,210 keystrokes, and the most prolific user has evidently typed 500,000,000 keystrokes, over a period of about 2 years.)
The original Project Dolphin was created in 2002, but was closed in 2003. Source code of the software and scripts allowed for a new Project Dolphin to be created by other people. The client software used to count keystrokes is called Pulse.

In late 2007 the project-dolphin.nl domain expired, and is now appareantly for sale. The stats server is still available at http://85.17.61.56/. Even though the website itself does open, no stats can be seen. Also, the ability to “pulse” keystrokes is unavailable.

External links

• Project-dolphin.nl

A solar engine can be:

• a Crookes radiometer : A light mill composed of an airtight glass bulb containing a partial vacuum. Inside are a set of vanes which are mounted on a spindle. The vanes rotate when exposed to light.
• a Solar Engine circuit, a BEAM component which receives radiant energy, capacitates the energy, and then utilizes that energy in pulses for motor power or to power other circuits.
• a Stirling engine, a heat engine of the external combustion piston engine type whose heat-exchange process allows for near-ideal efficiency in conversion of heat into mechanical movement.

Generator may refer to:

• Electrical generator
• Generator (mathematics), any of several closely related usages in mathematics.

Music

• “Generator” (song), a song by The Foo Fighters
• “Generator” (The Holloways song), a song by The Holloways
• Generator (album), an album by punk band Bad Religion, and its opening track

In computing:

• Generator (computer science), a specialized routine that acts like an iterator
• A program which produces a stream of data
• Pseudorandom number generator, producer of a sequence of random or nearly-random numbers
• Prime number generator, a producer of the ordered sequence of prime numbers
• A zero-generator, the pseudo-device /dev/zero outputs a never ending stream of zero-valued bytes
• Code generator, a program which creates source code as its output
• anything that creates source code automatically in generative programming
• Natural language generator, a program that produces human language from a machine representation
• Generator matrix, a matrix whose rows can generate all the elements of a linear code

In popular culture:

• A Generator in the anime Generator Gawl is a metal-organic hybrid organism with far greater powers than that of a human.

See also

• Generate

A Barker code is a sequence of N values of +1 and −1,

<math>a_j</math> for <math>j = 1, \cdot\cdot\cdot, N</math>

such that

<math>|\sum_{j=1}^{N-v} a_j a_{j+v}| \le 1\,</math>

for all <math>1 \le v < N</math>.

Here is a table of all known Barker codes, where negations and reversals of the codes have been omitted:

Barker codes of length 11 and 13 are used in direct-sequence spread spectrum and Pulse Compression Radar systems because of their low autocorrelation properties.

Barker codes utilize biphase modulation; that is, the change of phase in the carrier wave is 180 degrees.

See also

• Pseudorandom number sequence

References

• Barker Code — Mathworld

Continuous-wave radar system is a radar system where a known stable frequency continuous wave radio energy is transmitted and then received from any reflecting objects. The return frequencies are shifted away from the transmitted frequency based on the Doppler effect if they are moving.

The main advantage of the CW radars is that they are not pulsed and simple to manufacture. They have no minimum or maximum range (although the broadcast power level imposes a practical limit on range) and maximize power on a target because they are always broadcasting. However they also have the disadvantage of only detecting moving targets, as stationary targets (along the line of sight) will not cause a Doppler shift and the reflected signals will be filtered out. CW radar systems are used at both ends of the range spectrum; e.g., as radio-altimeters at the close-range end (where the range may be a few feet), and early warning radars at long range.

CW radars also have a disadvantage because they cannot measure range. Range is normally measured by timing the delay between a pulse being sent and received, but as CW radars are always broadcasting, there is no delay to measure. Ranging can be implemented, however, through a technique known as “chirping”, or frequency modulated continuous-wave radar. In this system the signal is not a continuous fixed frequency, but varies up and down over a fixed period of time. By comparing the frequency of the received signal to the one currently being sent, the difference in frequency can be accurately measured, and from that the time-of-flight can be calculated.

The military uses continuous-wave radar to guide semi-active radar homing (SARH) air-to-air missiles, such as the U.S. AIM-7 Sparrow. The launch aircraft illuminates the target with a CW radar signal, and the missile homes in on the reflected radar waves. Since the missile is moving at high velocities relative to the aircraft, there is almost always a strong return. Most modern air combat radars, even pulse Doppler sets, have a CW function for missile guidance purposes.

See also

• Doppler radar
• Fm-cw radar
• Pulse-doppler radar

Pulse Ultra was a four-piece alternative metal/hard rock music group from Montreal, Quebec.

History

Pulse Ultra was initially formed as Head Space in 1997 by guitarist Dominic Cifarelli and bassist Jeff Feldman. Drummer Maxx Zinno was added that same year, followed by vocalist Zo Vissa two years later.

Pulse Ultra’s break came in 2000 when the band met Taproot, with Cifarelli later passing on one of their demos to the band. Taproot guitarist Mike DeWolf, through their management team Velvet Hammer, later got the band signed with Atlantic Records.

After a year of songwriting, the band issued their debut album Headspace on July 16, 2002. The band would appear on the Ozzfest tour that year in support of the album’s release. Subsequently, the album failed to push the band into the mainstream, and were dropped by Atlantic Records in 2003.

Beginning late 2003, the band set to work on the follow up to Headspace. Unfortunately at some point during mid-2004, tensions within the band grew and vocalist Zo Vissa was kicked out. In a post on the band’s official forum, he stated that the split was amicable and they were all on good terms. Despite finding a replacement in Lukas Rossi, the band would disband shortly after. They are now all involved in other projects.

Members

• Zo Vissa – Vocals
• Dominic Cifarelli – Guitar
• Jeff Feldman – Bass
• Maxx Zinno – Drums

Discography

External links

• Pulse Ultra: VH1 page
  
• Pulse Ultra: MTV page

Echopraxia is the involuntary repetition or imitation of the observed movements of another. Even though it is considered a tic, it is a behaviour characteristic of some people with autism, Tourette syndrome, schizophrenia (especially catatonic schizophrenia), some forms of clinical depression and some other neurological disorders.

Etymology: Greek “echo (repetition)” and “praxia (action)”.

In mathematics, an automatic group is a finitely generated group equipped with several finite-state automata. These automata can tell if a given word representation of a group element is in a “canonical form” and can tell if two elements given in canonical words differ by a generator.

More precisely, let G be a group and A be a finite set of generators. Then an automatic structure of G with respect to A is a set of finite-state automata:

• the word-acceptor, which accepts for every element of G at least one word in A representing it
• multipliers, one for each <math>a \in A \cup \{1\}</math>, which accept a pair (w_1, w_2), for words w_i accepted by the word-acceptor, precisely when <math>w_1 a = w_2</math> in G.

The property of being automatic does not depend on the set of generators.

Properties

• Automatic groups have word problem solvable in quadratic time. A given word can actually be put into canonical form in quadratic time.

Examples of automatic groups

• Finite groups
• Negatively curved groups
• Euclidean groups
• Coxeter groups
• Braid groups
• Geometrically finite groups

Examples of non-automatic groups

• Baumslag-Solitar groups
• Non-Euclidean nilpotent groups

References

• Epstein, David B. A.; Cannon, James W.; Holt, Derek F.; Levy, Silvio V. F.; Paterson, Michael S.; Thurston, William P. Word processing in groups. Jones and Bartlett Publishers, Boston, MA, 1992. xii+330 pp. ISBN 0-86720-244-0

Ziyad Cattan is a dual citizen of Poland and Iraq.

According to an article published in The Independent, on September 19, 2005, Hazim al-Shaalan, Defense Minister of Iyad Allawi’s interim administration, appointed Ziyad Cattan, as the Defence Ministry’s procurement chief.

The Independent article describes massive fraud in the Defense Ministry’s procurement, which it describes as “the greatest theft in history”, which occurred under Cattan’s watch. Of expenditures of between $1 and $2 billion the article estimates only $200 million worth of usable equipment was purchased.

Cattan and his former boss al-Shaalan, are both living in Jordan, and refusing comment.

External links

• What has happened to Iraq’s missing $1bn?, The Independent, September 19, 2005

In ring theory and related areas of mathematics a central simple algebra (CSA) over a field K (also called a Brauer algebra after Richard Brauer), is a finite-dimensional associative algebra A, which is simple, and for which the center is exactly K. In other words, any simple algebra is a central simple algebra over its center.

For example, the complex numbers C form a CSA over themselves, but not over the real numbers R (the center of C is all of C, not just R). The quaternions H form a 4 dimensional CSA over R.

According to the Artin–Wedderburn theorem a simple algebra A is isomorphic to M(n,S) for some division ring S. Given two central simple algebras A ~ M(n,S) and B ~ M(m,T) over the same field F , A and B are called similar (or Brauer equivalent) if their division rings S and T are isomorphic. The set of all equivalence classes of central simple algebras over a given field F, under this equivalence relation, can be equipped with a group operation given by the tensor product of algebras. The resulting group is called the Brauer group Br(F) of the field F.

Properties

• Every automorphism of a central simple algebra is an inner automorphism (follows from Skolem-Noether theorem)
• If S is a simple subalgebra of a central simple algebra A then dim_FS divides dim_FA
• Every 4 dimensional central simple algebra over a field F is isomorphic to a quaternion algebra; in fact, it is either a two-by-two matrix algebra, or a division algebra

See also

• Brauer group
• Severi-Brauer variety

Mud Pulse Telemetry - The transmission of encoded data through a drilling rig’s drilling mud system using rapid fluctuations in the pressure of a closed loop circulating system. There are three common methods of mud pulse telemetry: Continuous wave, Positive pulse, and negative pulse.

See also:

EM telemetry

MWD (measurement while drilling)

LWD (logging while drilling)

Pulse Types

Continuous wave telemetry sends the sensory data accumulated by the downhole measurement tool, known as an MWD (measurement while drilling) or LWD (logging while drilling) tool, by phase variations in the rig standpipe in a specific analog signal sequence that can be converted to a digital signal by processors that can measure fluctuations in the medium’s pressure. Positive pulse telemetry sends the sensory data by pressure increases. Negative pulse is the same transmission of encoded data using pressure decreases.

Pulse Determination

All digital data is formed by combining ones and zeros, known as the binary numeral system format. When the MWD (measurement while drilling)/LWD (logging while drilling) tool transmits data, it is in the form of an analog signal that sends ones and zeros.
Combining the sequences of numbers into a word, (or symbol, or value or anything else a computer is programmed to look for), returns input for the specific variable the system was expecting at the time. Continued decoding of data will be achieved while the binary return values match the expected variable input data format.

Underbalanced Drilling

When underbalanced drilling is used, mud pulse telemetry can become unusable. This is because usually in order to reduce the equivalent density of the drilling mud a compressible gas is injected into the mud, drastically reducing its ability to transmit pulsed data. In this case it is necessary to use another method different than mud telemetry, such as electromagnetic waves to sensors located at the surface.

1. REDIRECT: Pulse-density modulation

In signal processing and telecommunication, the term pulse duration has the following meanings:

1. In a pulse waveform, the interval between (a) the time, during the first transition, that the pulse amplitude reaches a specified fraction (level) of its final amplitude, and (b) the time the pulse amplitude drops, on the last transition, to the same level.

   Note: The interval between the 50% points of the final amplitude is usually used to determine or define pulse duration, and this is understood to be the case unless otherwise specified. Other fractions of the final amplitude, e.g., 90% or 1/e, may also be used, as may the root mean square (rms) value of the pulse amplitude. Deprecated synonyms: pulse length, pulse width.

2. In radar, measurement of pulse transmission time in microseconds, that is, the time the radar’s transmitter is energized during each cycle.

Source: From Federal Standard 1037C and from MIL-STD-188 and from the Department of Defense Dictionary of Military and Associated Terms

In telecommunication, the term chirping has the following meanings:

1. The rapid changing, as opposed to long-term drifting, of the frequency of an electromagnetic wave.

Chirping is most often observed in pulsed operation of a source.

2. A pulse compression technique that uses (usually linear) frequency modulation during the pulse.

3. A trademarked term in mobile communications used by Nextel and Boost Mobile for sending voice messages to a private number in push-to-talk or walkie-talkie mode.

4. To make fun of someone from afar or to make fun of a good friend at anytime about things that are only “inside jokes”. It can be used in context as either a positive compliment or a negative retort.

See also: chirp.

Self-phase modulation (SPM) is a nonlinear optical effect of light-matter interaction.
An ultrashort pulse of light, when travelling in a medium, will induce a varying refractive index of the medium due to the optical Kerr effect. This variation in refractive index will produce a phase shift in the pulse, leading to a change of the pulse’s frequency spectrum.

Self-phase modulation is an important effect in optical systems that use short, intense pulses of light, such as lasers and optical fibre communications systems.

Theory

For an ultrashort pulse with a Gaussian shape and constant phase, the intensity at time t is given by I(t):

<math>I(t) = I_0 \exp \left(- \frac{t^2}{\tau^2} \right) </math>

where I₀ is the peak intensity, and τ is half the pulse duration.

If the pulse is travelling in a medium, the optical Kerr effect produces a refractive index change with intensity:

<math>n(I) = n_0 + n_2 \cdot I</math>

where n₀ is the linear refractive index, and n₂ is the second-order nonlinear refractive index of the medium.

As the pulse propagates, the intensity at any one point in the medium rises and then falls as the pulse goes past. This will produce a time-varying refractive index:

<math>\frac{dn(I)}{dt} = n_2 \frac{dI}{dt} = n_2 \cdot I_0 \cdot \frac{-2 t}{\tau^2} \cdot \exp\left(\frac{-t^2}{\tau^2} \right).</math>

This variation in refractive index produces a shift in the instantaneous phase of the pulse:

<math>\phi(t) = \omega_0 t - \frac{2 \pi}{\lambda_0} \cdot n(I) L</math>

where <math>\omega_0</math> and <math>\lambda_0</math> are the carrier frequency and (vacuum) wavelength of the pulse, and <math>L</math> is the distance the pulse has propagated.

The phase shift results in a frequency shift of the pulse. The instantaneous frequency ω(t) is given by:

<math>\omega(t) = \frac{d \phi(t)}{dt} = \omega_0 - \frac{2 \pi L}{\lambda_0} \frac{dn(I)}{dt},</math>

and from the equation for dn/dt above, this is:

<math>\omega(t) = \omega_0 + \frac{4 \pi L n_2 I_0}{\lambda_0 \tau^2} \cdot t \cdot \exp\left(\frac{-t^2}{\tau^2}\right).</math>

Plotting ω(t) shows the frequency shift of each part of the pulse. The leading edge shifts to lower frequencies (”redder” wavelengths), trailing edge to higher frequencies (”bluer”) and the very peak of the pulse is not shifted. For the centre portion of the pulse (between t = ±τ/2), there is an approximately linear frequency shift (chirp) given by:

<math>\omega(t) = \omega_0 + \alpha \cdot t</math>

where α is:

<math>\alpha = \left. \frac{d\omega}{dt} \right |_0 = \frac{4 \pi L n_2 I_0}{\lambda_0 \tau^2}.</math>

It is clear that the extra frequencies generated through SPM broaden the frequency spectrum of the pulse symmetrically. In the time domain, the envelope of the pulse is not changed, however in any real medium the effects of dispersion will simultaneously act on the pulse. In regions of normal dispersion, the “redder” portions of the pulse have a higher velocity than the “blue” portions, and thus the front of the pulse moves faster than the back, broadening the pulse in time. In regions of anomalous dispersion, the opposite is true, and the pulse is compressed temporally and becomes shorter. This effect can be exploited to some degree (until it diggs holes into the spectrum) to produce ultrashort pulse compression.

A similar analysis can be carried out for any pulse shape, such as the hyperbolic secant-squared (sech^{2</sub>) pulse profile generated by most ultrashort pulse lasers.}

If the pulse is of sufficient intensity, the spectral broadening process of SPM can balance with the temporal compression due to anomalous dispersion and reach an equilibrium state. The resulting pulse is called an optical soliton.

Carrier frequency is a term used to designate:

• The nominal frequency of a carrier wave
• The center frequency of a frequency modulation signal
• The frequency of the unmodulated electrical wave at the output of an amplitude modulated (AM), frequency modulated (FM), or phase modulated (PM) transmitter
• The output of a transmitter when the modulation is zero.

Casper is a male’s given name of Persian origin meaning “Master of the Treasure”. It is one of the traditional names assigned by folklore to the anonymous Magi mentioned in the Gospel of Matthew account of the Nativity of Jesus.

Alternate forms include:

• Jasper
• Jesper
• Caspar
• Gaspar
• Kasper
• Kasperi
• Kaspar
• Kacper
• Kaspor

Some people consider the name Casper to be a name of kingship.

The signal velocity of a wave is the speed at which a pulse travels through a medium. The signal velocity is usually defined from the position of half-maximum intensity of the pulse.

For electromagnetic waves such as light, the signal velocity is identical to the group velocity of the wave except when it is travelling through a medium with an absorption resonance close to the frequency of the wave. In this case, the phase velocity <math>v_\phi</math> may exceed the speed of light c, but the signal velocity v_s will always be less than or equal to c.

See also

• Dispersion (optics)
• Front velocity
• Phase velocity

References

• Brillouin, Léon. Wave propagation and group velocity. Academic Press Inc., New York (1960).

HappyDoc is a documentation generator for the Python programming language. It can produce code documentation in HTML, XML, SGML, or PDF, and is written by Doug Hellmann.

See also

• Comparison of documentation generators

External links

• HappyDoc

The signal velocity of a wave is the speed at which a pulse travels through a medium. The signal velocity is usually defined from the position of half-maximum intensity of the pulse.

For electromagnetic waves such as light, the signal velocity is identical to the group velocity of the wave except when it is travelling through a medium with an absorption resonance close to the frequency of the wave. In this case, the phase velocity <math>v_\phi</math> may exceed the speed of light c, but the signal velocity v_s will always be less than or equal to c.

See also

• Dispersion (optics)
• Front velocity
• Phase velocity

References

• Brillouin, Léon. Wave propagation and group velocity. Academic Press Inc., New York (1960).

There are a number of lists of fictional species:

Alien species (science fiction)

• List of extraterrestrials in fiction
• List of fictional robots

Fantasy species (fantasy fiction)

• List of species in fantasy fiction
• List of fictional dragons
  • List of dragons in fantasy fiction
• List of Pokémon
• List of Digimon
• List of The Future Is Wild species
  

Humanoid species

• List of fictional humanoid species

Plant species

• List of fictional plants

Katharine Q. Seelye is a political reporter for The New York Times.

External links

• New York Times bio
  

• Official Site’

Englemann-Camurati syndrome is a rare, non-fatal bone disorder that limits muscle strength.

People with the Camurati-Engelmann Syndrome

• John Belluso, writer for the CBS program “Ghost Whisperer”, was bound to a wheel chair since the age of 13 because of the Englemann-Camurati syndrome. He died on February 10, 2006, at the age of 36. He was found in his New York City hotel room. The cause of death has not yet been determined.