Generators info

In mathematics, a free Boolean algebra is a Boolean algebra with a distinguished set of elements, called generators, such that:

1. Each element of the Boolean algebra can be expressed as a finite combination of generators, using the Boolean operations, and
2. The generators are as independent as possible, in the sense that there are no relationships among them (again in terms of finite expressions using the Boolean operations) that do not hold in every Boolean algebra no matter which elements are chosen.

Motivation and example

The generators of a free Boolean algebra can represent independent propositions. For example, we might consider the two propositions “John is tall” and “Mary is rich”. These generate a Boolean algebra with four atoms, namely

1. John is tall, and Mary is rich
2. John is tall, and Mary is not rich
3. John is not tall, and Mary is rich
4. John is not tall, and Mary is not rich

Other elements of the Boolean algebra are then logical disjunctions of the atoms, such as “John is tall and Mary is not rich, or John is not tall and Mary is rich”. In addition there is one more element, FALSE, which is not a disjunction of atoms (though it can be thought of as the empty disjunction; that is, the disjunction of no atoms).

This example yields a Boolean algebra with 16 elements; in general, for finite n, the free Boolean algebra with n generators has 2ⁿ atoms, and therefore <math>2^{2^n}</math> elements.

For infinitely many generators the situation is very similar, except that there are no atoms. Each element of the Boolean algebra is a combination of finitely many of the generating propositions; two such elements are considered to be the same if they are logically equivalent.

Category-theoretic definition

More formally, using concepts from category theory, a free Boolean algebra on a set of generators S is an ordered pair (π,B), where

1. π: S → B is a mapping,
2. B is a Boolean algebra,

and which is universal with respect to this property. This means that for any Boolean algebra B₁ and mapping π₁: S → B₁, there is a unique homomorphism f: B → B₁ such that

<math> \pi_1 = f \circ \pi. </math>

This universality property can also be formulated as an initiality property in so-called comma categories.

The uniqueness up to isomorphism is a property that follows immediately from the universal property. Note that the mapping π can be shown to be injective. Thus any free Boolean algebra B has the property that there is a subset S of B, called the set of generators of B, such that any map from S into a Boolean algebra B₁ extends uniquely to a homomorphism from B into B₁.

Topological realization

For any desired number κ of generators, finite or infinite, the free Boolean algebra with κ generators may be realized as the collection of all clopen subsets of {0,1}^κ, given the product topology assuming that {0,1} has the discrete topology. The generators may be enumerated as follows: for each α<κ the α’th generator is the set of all elements of {0,1}^κ whose α’th coordinate is 1. In particular, the free Boolean algebra with <math>\aleph_0</math> generators is the collection of all clopen subsets of Cantor space. Perhaps surprisingly, there are only countably many of these. In fact, while for finite n the free Boolean algebra with n generators has cardinality <math>2^{2^n}</math>, for infinite κ the corresponding cardinality is just κ.

For the wider context of this topological realization, see the article on Stone’s representation theorem for Boolean algebras.

References

Saunders Mac Lane (1999) Algebra. 3d. edition, American Mathematical Society. ISBN 0-821-81646-2.

Ballochroy is a megalithic site in Kintyre on the Argyll peninsula in Scotland. It consists of three vertical stones, side by side, aligned with various land features 7-19 miles away.

Alexander Thom, known for his work on Stonehenge, maintained that the great length between the stones and the features of distant landscape lent precision to pinpointing the midsummer and winter solstices for ancient observers.

These three stones are considered the most spectacular set of megalithic monuments that cluster around south Argyll. The three mica schist stones were measured at 3.5m, 3.0m and 2.0m in height. It is possible that this last, smallest, stone may have been broken off at the top. This is unsure however. The line of stones is orientated north-east to south-west.

The flat face of the central stone (at right angles to the alignment) indicates the mountain of Cora Bheinn, on the island of Jura, which is 30 km away. The shortest stone also faces across the alignment, and points to Ben a’Chaolais, the southernmost of the four Paps of Jura. The sun setting here would have given warning of the approach of the solstice.

As with many megalithic sites, the current theories concerning the exact use of the stones at Ballochroy are somewhat controversial.

External links

Common Image Generator Interface (CIGI) is an interface designed to promote a standard way for a host device to communicate with an image generator (IG) in the simulation industry.

External links

• CIGI Official Site on Sourceforge

A bleeder resistor is a resistor placed in parallel with a high-voltage supply for the purposes of discharging the energy stored in the power source’s filter capacitors or other components that store electrical energy.

The bleeder resistor commonly found inside a flyback transformer that supplies high voltage for a CRT is valued in the hundreds of megaohms range, and can therefore not be measured with the common technician’s multimeter.

Instead of a resistor inside the transformer, the focus and screen control array may be used for the same purpose, depending on the application and tolerances of the type of tube it is producing output for.

The failure of a bleeder resistor prevents the discharge of the capacitors. This is the reason for the typical warning behind most equipment: “Warning - No user-serviceable parts inside”. An un-suspecting technician may get an electrical shock due to failure of a bleeder resistor.

There is always a trade-off between the speed with which the bleeder operates and the amount of power wasted in the bleeder; a faster bleed-down rate wastes more power during normal, power-on operation. Because of this, high-powered circuits often use two separate bleeder circuits. A fast bleed circuit is switched out during normal operation so that no power is wasted; when power is switched off, the bleeder is connected, rapidly bleeding down the voltage. Because this circuitry is somewhat complex, it may fail, either by connecting when it shouldn’t (and overheating) or by not connecting when it should (and thereby failing to bleed off the voltage). To avoid the risk of not having an operational bleeder, a secondary, slower (and less lossy) bleeder is usually permanently connected so that there is always some bleed-down capability.

In mathematics, a symmetric function of multiple variables is one that is invariant under permutation of its variables; that is, the value of the function does not depend on the order of the n-tuple of arguments.

In most contexts, the term refers to a polynomial with this property: a symmetric polynomial.
The theory of symmetric polynomials is part of the theory of polynomial equations, and also a substantial chapter of combinatorics. Examples of symmetric polynomials are

X₁ + X₂ + … + X_n ,

X₁³ + X₂³ + … + X_n³ ,

and

X₁X₂…X_n .

If P(x) is a polynomial with roots

α₁, α₂, …, α_n ,

a symmetric function of the roots of P means

S(α₁, α₂, …, α_n)

where S is a symmetric function of n variables.

There is a direct relation between certain symmetric functions of the roots and the coefficients in the polynomial P. Assume for simplicity that P is monic, so that

P(x) = xⁿ + a_n−1xⁿ⁻¹ + … + a₀ = (x − α₁)(x − α₂)…(x − α_n),

where the a_i are in a field K and the α_i are in the algebraic closure of K. The sum of all the α_i equals −a_n−1 and their product equals (−1)ⁿa₀. In fact, it is classical algebra (Viète’s formulas) that the intermediate coefficients of P are plus or minus the sums of the products of the roots taken j at a time, for 1 < j < n. (The sign is alternately + and −.) These formulae are the basis of the traditional theory of equations. In symbols the formulas say:

a_n−j = (−1)^n−j Σ α_k(1)…α_k(j)

with the summation taken over all index sequences

1 ≤ k(1) < … < k(j) ≤ n.

These sums for j = 1, 2, …, n are called the elementary symmetric functions of the roots, because the jth elementary symmetric polynomial, written σ_j, is given by the same formula, but in indeterminates X_i. A basic theorem states that any symmetric polynomial function S of n variables can be expressed as a polynomial in the elementary symmetric functions. In the solution of polynomial equations, the symmetric polynomials of the roots lie in K.

The polynomial relations underlying that assertion are universal (independent of choice of P); and, if we work with the symmetric polynomials created from a monomial, we can eliminate dependence on K, too, to get formulae with integer coefficients. Putting this more algebraically, we can define a subring Symm(n) of Z[X₁, X₂, …, X_n] consisting of the integral symmetric polynomials (those invariant under the action of the symmetric group on indices); and then assert that the formulae for σ_j, for which we retain the notation, are ring generators of Symm(n). What is more, they are independent generators (no algebraic relations hold), so that Symm(n) is abstractly also a polynomial ring on n generators. A great deal of attention was paid, in older algebra textbooks, to algorithmic procedures expressing the procedural content of this (which has been stated as an existence theorem but has computational content).

The most important single application is to the power sums α₁^k + α₂^k + … + α_n^k, in terms of the a_j. The formulae for doing this are attributed to Isaac Newton. They were encountered in K-theory too, where they underlie the Adams operations.

They also support the theory of the Newton polygon, part of the theory of ramification. In Newton’s case the point was to work with a_j in a formal power series ring; here passage to the algebraic closure is the theory of Puiseux expansions in fractional powers, and the Newton polygon is a device for computing the required exponents.

See also

• Newton’s identities
• Symmetric matrix

Functional verification, in electronic design automation, is the task of verifying that the logic design conforms to specification. In everyday terms, functional verification attempts to answer the question “Does this proposed design do what is intended?” This is a complex task, and takes the majority of time and effort in most large electronic system design projects.

Functional verification is very difficult - it is equivalent to program verification, and is NP-hard or even worse - and no solution has been found that works well in all cases. However, it can be attacked by many methods. None of them are perfect, but each can be helpful in certain circumstances:

• Logic simulation simulates the logic before it is built.
• Simulation acceleration applies special purpose hardware to the logic simulation problem.
• Emulation builds a version of system using programmable logic. This is expensive, and still much slower than the real hardware, but orders of magnitude faster than simulation. It can be used, for example, to boot the operating system on a processor.
• Formal verification attempts to prove mathematically that certain requirements (also expressed formally) are met, or that certain undesired behaviors (such as deadlock) cannot occur.
• HDL-specific versions of lint, and other heuristics, are used to find common problems.

Simulation based verification (also called ‘dynamic verification’) is widely used to “simulate” the design, since this method scales up very easily. Stimulus is provided to exercise each line in the HDL code. A test-bench is built to functionally verify the design by providing meaningful scenarios to check that given certain input, the design performs to specification.

A simulation environment is typically composed of several types of components:

• The generator (or irritator) generates input vectors. Modern generators generate random, biased, and valid stimuli. The randomness is important to achieve a high distribution over the huge space of the available input stimuli. To this end, users of these generators intentionally under-specify the requirements for the generated tests. It is the role of the generator to randomly fill this gap. This mechanism allows the generator to create inputs that reveal bugs not being searched for directly by the user. Generators also bias the stimuli toward design corner cases to further stress the logic. Biasing and randomness serve different goals and there are tradeoffs between them, hence different generators have a different mix of these characteristics. Since the input for the design must be valid (legal) and many targets (such as biasing) should be maintained, many generators use the Constraint Satisfaction Problem (CSP) technique to solve the complex testing requirements. The legality of the design inputs and the biasing arsenal are modeled. The model-based generators use this model to produce the correct stimuli for the target design.
• The drivers translate the stimuli produced by the generator into the actual inputs for the design under verification. Generators create inputs at a high level of abstraction, namely, as transactions or assembly language. The drivers convert this input into actual design inputs as defined in the specification of the design’s interface.
• The simulator produces the outputs of the design, based on the design’s current state (the state of the flip-flops) and the injected inputs. The simulator has a description of the design net-list. This description is created by synthesizing the HDL to a low gate level net-list.
• The monitor converts the state of the design and its outputs to a transaction abstraction level so it can be stored in a ’score-boards’ database to be checked later on.
• The checker validates that the contents of the ’score-boards’ are legal. There are cases where the generator creates expected results, in addition to the inputs. In these cases, the checker must validate that the actual results match the expected ones.
• The arbitration manager manages all the above components together.

Different coverage metrics are defined to assess that the design has been adequately exercised. These include function coverage (has every function been exercised?), statement coverage (has each line of HDL been exercised?), and branch coverage (has each direction of every branch been exercised?). None of these are sufficient to prove a design works, but all are helpful in pointing out areas of the HDL that have not been tested.

External links

Certess, Inc. product’s : Certitude

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 AC electrical power systems, a synchroscope is a device that indicates the degree to which two systems (generators or power networks) are synchronized with each other.

For two electrical systems to be considered synchronized, both systems must be operating at the same frequency, and the phase angle between the systems must be zero. Synchroscopes measure and display the frequency difference and phase angle between two power systems.

It is not possible to connect two AC power systems unless the systems are synchronized.

Use in Power Plants

Since it is necessary to synchronize AC power systems before connecting them, synchroscopes are used in any power plant that connects to an outside power grid and also in isolated plants containing more than one generator, as each generator must be synchronized with the others before being connected to the plant bus.

When the operator of an electric generator wishes to connect a generator to the grid, they will first start the generator spinning at a rate approximately equal to the line frequency of the grid with which they plan to connect. A synchroscope will then be connected to the power grid and to the generator being started.

If the generator is turning at a lower frequency than the grid, the synchroscope needle will rotate in the direction (usually counterclockwise) marked “slow” or “lag” on the dial to indicate that the generator is running slower than, or lagging behind, the grid. If the generator is running faster than the grid, the needle will rotate in the opposite direction, marked “fast” or “lead”. Next, the plant operator will adjust the speed of the generator until it is running at precisely the same speed (frequency) as the grid. As the frequency of the generator nears that of the grid, the synchroscope needle will slow down and when the frequencies match, the needle will stop moving.

At this point, there is one more task to perform before the generator can be connected to the grid. Although the generator and the grid are now operating at the same frequency, they are not necessarily at the same position in the rotational cycle as each other. If two electrical networks operating at two different phase angles were to be connected to each other, a fault similar to a short circuit would occur and most likely destroy the generator and damage the grid.

The position (as opposed to movement) of the needle on a synchroscope indicates the current phase angle between the two systems. The angle between the systems is zero when the synchroscope needle is pointing directly to the line in between the “slow” and “fast” markings on the dial. (In the picture example in this article, the zero-phase-angle position is straight upwards, at the twelve o’clock position.)

If the needle reads “fast,” then the plant’s generator should be slowed down by a very small amount and the needle will turn counterclockwise (toward the zero mark). Alternatively, if the needle reads “slow,” then the plant operator will speed the generator up slightly, and the needle will turn clockwise. Slightly before the needle reaches the zero mark, the plant operator will return the generator to the grid frequency in order to stop the needle when it reaches the zero mark. When the needle is at zero and is not moving, the two systems are synchronized.

Once the two systems are synchronized, they can be safely connected.

References

• Technical description of how a synchroscope works:

http://www.tpub.com/content/doe/h1011v4/css/h1011v4_98.htm

• Program demonstrating operation of a Synchroscope:

http://www.nhancetech.com/nht_web.nsf/frmViewDemoDownloads!OpenForm

A Bipolar Violation, or BPV, is an error in the transmission of a T1 signal where two pulses of the same polarity occur without an intervening pulse of the opposite polarity.

T1 signals are transmitted using a scheme called Alternate Mark Inversion (AMI), where a ONE is represented by a pulse, and a ZERO is represented by no pulse. Pulses-which represent ones-always alternate in polarity, so that if, for example two positive pulses are received in succession, the receiver knows that one or more bits were either added or deleted from the original signal.

B8ZS coding is a scheme used in addition to AMI, which allows longer strings of consecutive zeroes to be transmitted.

Pulse pressure is the change in blood pressure seen during a contraction of the heart.

Calculation

Formally it is the systolic pressure minus the diastolic pressure.

Theoretically, the pulse pressure can be conceptualized as stroke volume X compliance. For instance, even though the right and left ventricles have similar stroke volumes, because the aorta is the most compliant vessel (due to the large amount of elastic fibers) the aortic pulse pressure is much greater than the pulmonary pulse pressure.

Values and variation

Usually, the resting pulse pressure in healthy adults, sitting position, is about 40 mmHg. The pulse pressure increases with exercise due to increased stroke volume, healthy values being up to pulse pressures of about 100 mmHg, simultaneously as total peripheral resistance drops during exercise. In healthy individuals the pulse pressure will typically return to normal within about 10 minutes.

For most individuals, during exercise, the systolic pressure progressively increases while the diastolic remains about the same. In some very aerobically athletic individuals, the diastolic will progressively fall as the systolic increases. This behavior facilitates a much greater increase in stroke volume and cardiac output at a lower mean arterial pressure and enables much greater aerobic capacity and physical performance. The diastolic drop reflects a much greater fall in total peripheral resistance of the muscle arterioles in response to the exercise (a greater proportion of red versus white muscle tissue).

Low values

If the usual resting pulse pressure is measured as less than 40 mmHg, the most common reason is an error of measurement. If the pulse pressure is genuinely low, e.g. 25 mmHg or less, the cause may be low stroke volume, as in Congestive Heart Failure and/or shock, a serious issue. This interpretation is reinforced if the resting heart rate is relatively rapid, e.g. 100-120 (in sinus tachycardia), reflecting increased sympathetic nervous system activity and the body’s response to low stroke volume and low cardiac output.

High values

If the usual resting pulse pressure is consistently greater than 40 mmHg, e.g. 60 or 80 mmHg, the most likely basis is stiffness of the major arteries, aortic regurgitation (a leak in the aortic valve), arteriovenous malformation (an extra path for blood to travel from a high pressure artery to a low pressure vein without the gradient of a capillary bed), hyperthyroidism or some combination. (A chronically increased stroke volume is also a technical possibility, but very rare in practice.) Some drugs for hypertension have the side effect of increasing resting pulse pressure irreversibly. A high resting pulse pressure is harmful and tends to accelerate the normal ageing of body organs, particularly the heart, the brain and kidneys. A high pulse pressure combined with bradycardia is associated with increased intracranial pressure and should be reported to a physician immediately.

Relationship to heart disease

Recent work suggests that a high pulse pressure is an important risk factor for heart disease. A meta-analysis in 2000, which combined the results of several studies of 8,000 elderly patients in all, found that a 10 mm Hg increase in pulse pressure increased the risk of major cardiovascular complications and mortality by nearly 20%.Blacher J, Staessen JA, Girerd X, Gasowski J, Thijs L, Liu L, Wang JG, Fagard RH, Safar ME. Pulse pressure not mean pressure determines cardiovascular risk in older hypertensive patients. Arch Intern Med 2000 Apr 24;160(8):1085-9. PMID 10789600 The authors suggest that this helps to explain the apparent increase in risk sometimes associated with low diastolic pressure, and warn that some medications for high blood pressure may actually increase the pulse pressure and the risk of heart disease.

See also

• Blood pressure
• Mean arterial pressure

References

The Cégep André-Laurendeau is a Cégep pre-university and technical college located at 1111 Lapierre Street in Montreal (LaSalle), Quebec, Canada.

The Cegep offers ten Technical formations:

• Gestion de commerces (410.D0)
• Soins infirmiers (180.A0)
• Techniques de bureautique (412.A0)
• Techniques de comptabilité et de gestion (410.B0)
• Techniques de l’informatique (420.A0)
• Techniques de la logistique du transport (410.A0)
• Technologie de l’architecture (221.A0)
• Technologie de l’électronique industrielle (243.06)
• Technologie du génie civil (221.B0)
• Technologie physique (244.A0) (Profil Nanotechnologie et photonique)

External links

• Official site (in French)

Adson’s sign is seen during abduction and external rotation at the shoulder, where there is loss of the radial pulse in the arm. It can be a sign of thoracic outlet syndrome. Thoracic outlet obstruction may be caused by a number of abnormalities, including degenerative or bony disorders, trauma to the cervical spine, fibromuscular bands, vascular abnormalities, and spasm of the anterior scalene muscle. Symptoms are due to compression of the brachial plexus and subclavian vasculature, and consist of complaints ranging from diffuse arm pain to a sensation of arm fatigue, frequently aggravated by carrying anything in the ipsilateral hand or doing overhead work such as window cleaning.

As cited in the literature the Adson’s sign is loss of radial pulse while turning the head to the contralateral side, slightly elevating the chin and breathing in.

See also

• White hand sign

References

A CO-oximeter is a device for of detecting hypoxia, a medical condition relating to oxygen deficiency at tissue level. It is an enhanced version of a pulse oximeter operating with more than two wavelengths.

The device measures absorption at several wavelengths to distinguish oxyhemoglobin from carboxyhemoglobin and determine the oxyhemoglobin saturation: the percentage of oxygenated Hb compared to the total amount of Hb, including carboxy-Hb, met-Hb, oxy-Hb, and reduced Hb. When a patient presents with carbon monoxide poisoning, the CO-oximeter will detect this Hb and will report the oxyhemoglobin saturation as markedly reduced.

See also

Pulse oximeter

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.

Adson’s sign is seen during abduction and external rotation at the shoulder, where there is loss of the radial pulse in the arm. It can be a sign of thoracic outlet syndrome. Thoracic outlet obstruction may be caused by a number of abnormalities, including degenerative or bony disorders, trauma to the cervical spine, fibromuscular bands, vascular abnormalities, and spasm of the anterior scalene muscle. Symptoms are due to compression of the brachial plexus and subclavian vasculature, and consist of complaints ranging from diffuse arm pain to a sensation of arm fatigue, frequently aggravated by carrying anything in the ipsilateral hand or doing overhead work such as window cleaning.

As cited in the literature the Adson’s sign is loss of radial pulse while turning the head to the contralateral side, slightly elevating the chin and breathing in.

See also

• White hand sign

References

In the science fiction television show Stargate SG-1, the Naqahdah generator is a power source which can provide enormous and practically endless amounts of clean energy. The device uses the fictional element Naqahdah to provide power.

About

The Earth version of the device was created by Samantha Carter, based on Orbanian designs.”Learning Curve” (Stargate SG-1) The Naqahdah generator has been used to power not only many Earth-based technologies but can be adapted to power other alien technology, including the Ancients’. The generator is less than a meter long, and is shaped rather like a dumbbell with spheres at its ends.

A Naqahdah generator can also be converted into a devastating bomb,”Scorched Earth” (Stargate SG-1); several are set to be employed in this manner in Atlantis’s self-destruct system.”The Siege” (Stargate Atlantis) The device emits a powerful electromagnetic pulse when detonated, similar to those emitted by nuclear weapons.”Hot Zone” (Stargate Atlantis)

The generators have been seen to power a handful of different Earth and Ancient Technology, including until recently, Daedalus class ships. The generators were abandoned on the Odyssey for a ZPM and later, an Asgard computer core. At least one generator powered Prometheus before it was destroyed.

The United States government was supposed to share this technology with Russia as part of the agreement that saw the end of the Russian Stargate programme, but failed to do so immediately. They were eventually forced to share it, as well as other technology, with Russia in exchange for their DHD.”48 Hours” (Stargate SG-1)

Variations

“Mini” Naqahdah Generator

This variation of the Nahqahdah generator was mounted to the X699 prototype plasma weapon that was presented to a technology conference by Dr Lee. This generator was mounted to part of the prototype, it appeared to be of the same configuration as the larger versions of the Nahqahdah generator employed by Stargate Command, but due to its reduced size, it is presumed to either have a reduced output, or contain enhancements to the technology that allow for a smaller unit to generate the same amount of power as the older, larger versions.”Bounty” (Stargate SG-1)

Mark II Naqahdah generator

The Mark II Naqahdah generator was later developed, and is able to operate stably at a state of barely controlled overload. This type of generator achieves 600% of the power output of a Mark I, producing sufficient power for two generators to operate the Ancient control chair for a short period, something which previously required a Zero Point Module. Nevertheless, it does not produce enough power to operate the Atlantis main shield, nor can it provide a Stargate with enough power to establish a long-lasting intergalactic wormhole. A pair of these devices were successful in powering the chair in Antarctica.”No Man’s Land” (Stargate Atlantis)

Also, at least two Mark II generators are placed in the ZPM room in Atlantis as a back up power source on Atlantis.”Critical Mass” (Stargate Atlantis)

The Mark II’s reactor casing appears to be much closer to the original Orbanian design that Stargate Command initially studied. The naqahdah is housed in what appears to be a casing identical to the Mark I reactor. The reactor itself is a long grey rectangular shape with a keypad and LCD display at the center of the unit. There are two smaller keypads on one side of the device to control the power generator’s output and numerous lights to identify the state of the generator’s activity.

References

External links

• “Naqahdah generator” at GateWorld Omnipedia.

In finance, a forward rate agreement (FRA) is a forward contract in which one party pays a fixed interest rate, and receives a floating interest rate equal to a reference rate (the underlying rate). The payments are calculated over a notional amount over a certain period, and netted, i.e. only the differential is paid. It is paid on the termination date. The reference rate is fixed zero, one or two days before the termination date, dependent on the market convention for the particular currency. FRAs are over-the counter derivatives. A swap is a combination of FRAs.

The payer of the fixed interest rate is also known as the borrower or the buyer, whilst the receiver of the fixed interest rate is the lender or the seller.

Payoff formula

The netted payment made at the termination date is:

<math>
\mbox{Payment} = \mbox{Notional Amount} * \left( \frac{(\mbox{Reference Rate}-\mbox{Fixed Rate}) * \alpha }{ \mbox{Reference Rate} * \alpha +1} \right)
</math>

• The Fixed Rate is the rate at which the contract is agreed.
• The Reference Rate is typically Euribor or LIBOR.
• <math>\alpha </math> is the day count fraction, i.e. the portion of a year over which the rates are calculated, using the day count convention used in the money markets in the underlying currency. For EUR and USD this is generally the number of days divided by 360, for GBP it is the number of days divided by 365 days.
• The Fixed Rate and Reference Rate are rates that should accrue over a period starting on the termination date, and then paid at the end of the period. However, as the payment is already known at the beginning of the period, it is also paid at the beginning. This is why the discount factor is used in the denominator.

A Forward Rate Agreement is an agreement between two parties to settle the difference between an agreed level of interest and an actual future level of interest. The contract is agreed at the start of the period for which the interest is fixed.

FRAs Notation

FRA Descriptive Notation and Interpretation

See also

• Derivative (finance)
• List of finance topics

The NOM interface is a simplified version of the Simple DirectMedia Layer (SDL) library. It features functions of SDL code that are packaged for specific usage, so that your code isn’t long or complicated. It features 3D, pixel manipulation, distortion, easy sound management, and a nifty pre-built window system for window-based applications or games. It also features a key aspect to all 2D RPG/Action games: A tilemap function. It was created by Bladestrife in early 2005 for a game that shared the same title. The game was dropped and NOM became the New Operations Mainframe.

A pulse-width modulation integrated circuit, or PWMIC, describes any integrated circuit which uses pulse-width modulation to regulate voltage. The most common example of a PWMIC is a group of MOSFETs.

Nicola is an ancient (but still very common) Italian male personal name (from the Greek and Byzantine Νικόλαος) derived from Nichos meaning “victory,” and laos meaning “people,” therefore implying the meaning “winner of the people.” The English form of the same name is Nicholas.

Nicola was a frequently given male personal name among the traditional Italian nobility, and was used often in the Middle Ages. In the UK, Poland and Germany the male form Nicola has been used as a female name, which originally came from incorrectly presuming the name’s vowel ending ‘a’ was the female form, as has also occurred with the male given name Andrea (also an Italian male personal name from the Greek meaning ‘manly.’) The proper female form of Nicola in Italian is Nicoletta. An excellent reference for the name form and biblical history is The Golden Legend or Lives of the Saints. Compiled by Jacobus de Voragine, Archbishop of Genoa, 1275. First Edition Published 1470.

See also

• List of people known as Nicola

Carding may refer to :

• A carder is someone who “cards” or combs material in order to align the fibres as in carding wool. Carders used large steel combs, cards, to align the fibres of raw sheep fleeces to enable them to be further processed. This process combs out some of the dirt, organizes the fibers, and fluffs up the wool with air so the ’spinner’ can use it easily.

• A carder is a criminal who engages in carding, a form of identity theft. Carders use lists of credit and debit card information to perpetrate multiple acts of fraud (by web or by phone), by making purchases without the consent of the original cardholder.

Carders may obtain card numbers by various means:

• • Hacking servers operated by online merchants who store unencrypted card information.
  • Extracting card information from data keyed into consumer machines infected with a keystroke logging virus.
  • Trading or purchasing lists of cards from other online criminals.
  • Engaging in phishing scams to intercept card information.

Carders may also use card generators. These are programs that extrapolate sequences of potentially valid new card numbers from a single card that is known to be valid. Card generators are generally ineffective following the adoption of expiry, AVS, CVV and PIN validation.

Carders may also veer into other forms of identity theft, such as obtaining the credentials (username and password) of consumers with online payment accounts, such as PayPal.

Carding is a form of wire fraud, and is a federal offense in the United States.

Gain-switching is a technique in optics by which a laser can be made to produce pulses of light of extremely short duration, of the order of picoseconds (10^-12s).

In a semiconductor laser, the optical pulses are generated by injecting a large number of carriers (electrons) into the active region of the device, bringing the carrier density within that region from below to above the lasing threshold. When the carrier density exceeds that value, the ensuing stimulated emission results in the generation of a large number of photons.

However, carriers are depleted as a result of stimulated emission faster than they are injected. So the carrier density eventually falls back to below lasing threshold which results in the termination of the optical output. If carrier injection has not ceased during this period, then the carrier density in the active region can increase once more and the process will repeat itself.

The figure on the right shows a typical pulse generated by gain-switching with a sinusoidal injection current at 250 MHz producing a pulse of approximately 50 ps. Notice the depletion in carrier density during the pulse, and its subsequent rise due to continued current injection giving rise to a smaller secondary pulse.

For solid-state and dye lasers, gain switching (or synchronous pumping) usually involves the laser gain medium being pumped with another pulsed laser. Since the pump pulses are of short duration, optical gain is only present in the laser for a short time, which results in a pulsed output. Q-switching is more commonly used for producing pulsed output from these types of laser, as pulses with much higher peak power can be achieved.

The term gain-switching derives from the fact that the optical gain is negative when carrier density or pump intensity in the active region of the device is below threshold, and switches to a positive value when carrier density or the pump intensity exceeds the lasing threshold.

See also

• Q-switching
• Modelocking

Still Life is an album by Van der Graaf Generator. It was originally released in 1976. One bonus track was added for the 2005 rerelease.

Track listing

All songs written by Peter Hammill, except where noted

1. “Pilgrims” (Hammill/David Jackson) – 7:12
2. “Still Life” – 7:24
3. “La Rossa” – 9:52
4. “My Room (Waiting for Wonderland)” – 8:02
5. “Childlike Faith in Childhood’s End” – 12:24
6. “Gog (live) - 12:23*

• *was the 2005 bonus track.

Personnel

• Peter Hammill – vocals, guitar, keyboards
• David Jackson– saxophone, flute
• Hugh Banton - organ
• Guy Evans - drums, percussion

References

VAN DER GRAAF GENERATOR Still Life reviews and MP3 @ progarchives.com retrieved 9-1-07

In probability and statistics, the logarithmic distribution (also known as the logarithmic series distribution) is a discrete probability distribution derived from the Maclaurin series expansion

<math> -\ln(1-p) = p + \frac{p^2}{2} + \frac{p^3}{3} + \cdots. </math>

From this we obtain the identity

<math>\sum_{k=1}^{\infty} \frac{-1}{\ln(1-p)} \; \frac{p^k}{k} = 1. </math>

This leads directly to the probability mass function of a Log(p)-distributed random variable:

<math> f(k) = \frac{-1}{\ln(1-p)} \; \frac{p^k}{k}</math>

for <math>k \ge 1</math>, and where <math>0<p<1</math>. Because of the identity above, the distribution is properly normalized.

The cumulative distribution function is

<math> F(k) = 1 + \frac{\Beta_p(k+1,0)}{\ln(1-p)}</math>

where <math>\Beta</math> is the incomplete beta function.

A Poisson mixture of Log(p)-distributed random variables has a negative binomial distribution. In other words, if <math>N</math> is a random variable with a Poisson distribution, and <math>X_i</math>, <math>i</math> = 1, 2, 3, … is an infinite sequence of independent identically distributed random variables each having a Log(p) distribution, then

<math>\sum_{n=1}^N X_i</math>

has a negative binomial distribution. In this way, the negative binomial distribution is seen to be a compound Poisson distribution.

R.A. Fisher applied this distribution to population genetics.

See also

• Poisson distribution (also derived from a Maclaurin series)

In the nervous system, afferent neurons–otherwise known as sensory or receptor neurons–carry nerve impulses from receptors or sense organs toward the central nervous system. This is the case vice versa as well. This term can also be used to describe relative connections between structures. Afferent neurons communicate with specialized interneurons. (The opposite activity of direction or flow is efferent.)

In the nervous system there is a “closed loop” system of sensation, decision, and reactions. This process is carried out through the activity of afferent neurons, interneurons, and efferent neurons.

A touch or painful stimulus, for example, creates a sensation in the brain only after information about the stimulus travels there via afferent nerve pathways. Afferent neurons are pseudounipolar neurons, that have a single long dendrite and a short axon, and a smooth and rounded cell body. The dendrite is structurally and functionally similar to an axon, and is myelinated; it is these axon-like dendrites that make up the afferent nerves. Just outside the spinal cord, thousands of afferent neuronal cell bodies are aggregated in a swelling in the dorsal root known as the dorsal root ganglion. (See efferent nerve.)

Etymology and mnemonics

Both afferent and efferent come from french, as evolution from latin (much used in medicine and biology) of respectively ad ferentes (latin verb fero : I carry), meaning carrying into, and ex ferentes, meaning carrying away. Ad and ex give an easy mnemonic device for remembering the relationship between afferent and efferent : afferent connection arrives and an efferent connection exits.

References

External links

Edwin J. Houston (1847–1914) was an American electrical inventor. He helped design an arc light generator with Elihu Thomson.

See also

• Thomson-Houston Electric Company

References

End distortion: In start-stop teletypewriter operation, the shifting of the end of all marking pulses, except the stop pulse, from their proper positions in relation to the beginning of the next start pulse.

Shifting of the end of the stop pulse is a deviation in character time and rate rather than an end distortion.

Spacing end distortion is the termination of marking pulses before the proper time. Marking end distortion is the continuation of marking pulses past the proper time.

The magnitude of the distortion is expressed as a percentage of an ideal pulse length.

Doc-O-Matic is a commercial automatic documentation generator that creates fully cross linked documentation systems, including both Source Code Documentation, Online Help and User Manuals in PDF, browser-based Help, HTML Help, MS Help 2, Windows Help, RTF and XML. Doc-O-Matic supports all major project file formats as well as the following programming languages: C/[[C++]], C++/CLI, C#, Delphi, Java, IDL, VB.NET, JavaScript, MATLAB, ASP.NET, JSP.

See

also

• Comparison of documentation generators

External links

Project Doc-O-Matic home page

A fantasy wargame is a wargame that involves a fantastical setting, and employs rules for items such as magic and non-human intelligent creatures.

The rise in popularity in wargaming of the 1950s through to the 1970s largely coincided with the rise in popularity of J. R. R. Tolkien’s The Lord of the Rings novel. While wargaming was initially focused on historical subjects, other subjects also emerged, with the fantasy supplement to Chainmail (1971) leading to the development of Dungeons and Dragons.

All the common elements of fantasy literature, including fantasy races (elves, trolls, orcs, zombies etc.) and forms of magic (wizards, psychics, witches, sorcerers, etc.) can be found in fantasy wargames.

Popular fantasy miniature wargames include:

• Kingdoms of Arcania
• Confrontation
• Fantasy Gaming
• Flintloque
• Lord of the Rings
• Mage Knight
• Warhammer 40,000 (the setting is properly a dystopian science-fantasy mix)
• Warhammer Fantasy Battle
• Warmachine

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…

A vortex generator is an aerodynamic surface, consisting of a small vane that creates a vortex. They can be found in many devices, but the term is most often used in aircraft design.

Vortex generators are added to the leading edge of a swept wing in order to maintain steady airflow over the control surfaces at the rear of the wing. They are typically rectangular or triangular, tall enough to protrude above the boundary layer, and run in spanwise lines near the thickest part of the wing. They can be seen on the wings and vertical tails of many airliners. Vortex generators are positioned in such a way that they have an angle of attack with respect to the local airflow.

A vortex generator creates a tip vortex which draws energetic, rapidly-moving air from outside the slow-moving boundary layer into contact with the aircraft skin. The boundary layer normally thickens as it moves along the aircraft surface, reducing the effectiveness of trailing-edge control surfaces; vortex generators can be used to remedy this problem, among others, by re-energizing the boundary layer. Vortex generators delay flow separation and aerodynamic stalling; they improve the effectiveness of control surfaces (e.g Embraer 170 and Symphony SA-160); and, for swept-wing transonic designs, they alleviate potential shock-stall problems (e.g. Harrier, Blackburn Buccaneer, Gloster Javelin).

Many aircraft carry vane vortex generators from time of manufacture, but there are also after-market suppliers who sell VG kits to improve the STOL performance of some light aircraft.

Air jet vortex generators work on a different principle. They direct a jet of air into the boundary layer, thereby re-energising it.

Vortex generators are also being used in automotive vehicles. In one form they are used as in aircraft to influence the boundary layer of air flow primarily for drag reduction. In another form they are installed in the engine’s air intake hose. Manufacturers claim that the vortex generator creates a swirling motion within the air intake pipe, and within the combustion chamber causing improved burning of the fuel, increasing horsepower and fuel efficiency.

See also

• Turbulator
• Boundary layer suction

External links

• Aeronautical Testing Service, Inc. Manufacturer of Vortex Generator Kits

Femtochemistry is the science that studies chemical reactions on extremely short timescales, approximately 10^–15 seconds (this is one femtosecond, hence the name).

In 1999, Ahmed H. Zewail received the Nobel Prize in Chemistry for his pioneering work in this field.

Zewail’s technique uses flashes of laser light that last for a few femtoseconds. Femtochemistry is the area of physical chemistry that addresses the short time period in which chemical reactions take place and investigates why some reactions occur but not others. Zewail’s picture-taking technique made possible these investigations. One of the first major discoveries of femtochemistry was to reveal details about the intermediate products that form during chemical reactions, which cannot be deduced from observing the starting and end products. Many publications have discussed the possibility of controlling chemical reactions by this method, but this remains controversial.

The simplest approach and still one of the most common techniques is known as pump-probe spectroscopy. In this method, two or more optical pulses with variable time delay between them are used to investigate the processes happening during a chemical reaction. The first pulse (pump) initiates the reaction, by breaking a bond or exciting one of the reactants. The second pulse (probe) is then used to interrogate the progress of the reaction a certain period of time after initiation. As the reaction progresses, the response of the reacting system to the probe pulse will change. By continually scanning the time delay between pump and probe pulses and observing the response, workers can follow the progress of the reaction in real time.

External links

• The 1999 Nobel Prize in Chemistry, article on nobelprize.org

MoTeC

MoTeC is an Australian company founded in 1987, specializing in advanced automotive racing products.

Areas of MoTeC specialty include:

• data

acquisition

MoTeC manufactures engine control units as well as instrumentation and data logging equipment, including telemetry equipment. Most of their business involves automobile and motorcycle sport. MoTeC also produces PC software to make their products more usable.

External links

• MoTeC - official site

The tunnel of light is an element of the usual near-death experience. People experience floating upwards peacefully through a long tunnel, at the end of which is a beautiful demulcent light. It remains to be determined whether this phenomenon is universal or not, and whether it is subjective or objective.

Bit level device has several meanings, which can be separated by considering their antonyms:

• A bit level device provides its output in binary format, whereas a pulse level device outputs raw voltages. A digital circuit or computer needs a separate controller or converter device to receive information from a pulse level device.

• A bit level device considers the data a continuous stream of information, whereas a packet level device divides the data into packets.

• A bit level device sends and receives data one bit at a time. A byte level device sends and receives data a byte at a time, a word level device sends and receives a word at a time, etc.

• Also, a bit level device may refer to a device that considers the data it deals with opaque, i.e. it doesn’t care about the semantics, or meaning, of the data.

Eastwood Guitars is a company set up by Michael Robinson which reproduces some classic electric guitar designs.

The company was set up because Michael Robinson wanted to re-create some of the vintage electric guitars that have since gone out of production. He wanted to create guitars with vintage sound and feel, but that were meant to be played not just collected, as he thought so many vintage guitars were simply for looking at, not touching.

Eastwood guitars now produce around 20 guitar models, which have been greatly received by players and reviews. They also produce bass guitars which are either reproductions of classic bass guitar designs or adopted from their guitar designs.

External links

• MyRareGuitars - Home of Michael Robinson and Eastwood guitars
• Eastwood guitars only homepage

In electronics, fall time (pulse decay time) <math>t_f\,</math> is the time required for the amplitude of a pulse to decrease (fall) from a specified value (usually 90 percent of the peak value exclusive of overshoot or undershoot) to another specified value (usually 10 percent of the peak value exclusive of overshoot or undershoot). Limits on undershoot and oscillation (i.e. hunting) may need to be specified when specifying fall time limits.

See also

• Federal Standard 1037C
• MIL-STD-188
• Rise time
• Transition time

References

• Federal Standard 1037C “Telecommunications: Glossary of Telecommunication Terms“[1]

The 4Pi-STED-microscope is the result of combining the two unrelated concepts of STED- and 4Pi-microscopy. Here, the fluorescent sample is placed in the common focus of two opposing lenses, but excitation and detection are performed through a single lens (4Pi mode A). The green excitation pulse is immediately followed by a red STED-pulse, which enters the focal region through both lenses inducing stimulated emission of the excited fluorescent molecules to the ground state. To permit fluorescence emission from the center but suppress it from neighbouring regions it is useful to phaseshift the STED beam to have a minimum at the center.

External links

Technical details

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

The Device Manager is a Control Panel applet included with Microsoft Windows operating systems that allows the user to display and control the hardware attached to the computer. When a piece of hardware is not working, the offending hardware is highlighted where the user can deal with it. The list of hardware can be sorted by various criteria.

For each device in the list, users can:

• Supply device drivers to the hardware
• Enable or disable devices
• Tell Windows to ignore malfunctioning devices
• View other technical properties

Device Manager was introduced with Windows 95 and later added to Windows 2000. In NT-based versions, it is included as an MMC snap-in.

• 1 Invoking the Device Manager
• 2 See also
• 3 External links
  • 3.1 Windows-specific articles

Invoking the Device Manager

Windows 95/98/Me:

• Right-click My Computer then select Properties
• Select the Device Manager tab
  

Windows 2000 and Windows XP:

• Right-click My Computer then select Properties
• Select the Hardware tab
• Click the Device Manager button

• Alternative solution: invoke devmgmt.msc

• Alternative solution #2: Device Manager is part of the Computer Management, which also includes Event Viewer, Services Manager, Disk Management, as well as many other things. Right-Click My Computer then select Manage to start Computer Management, or invoke compmgmt.msc.

Windows Vista:

• Open the Start menu, right-click on Computer, select Manage
• Click on “Device Manager” in the left-hand tree
• Alternative solution: run devmgmt.msc

• Alternative solution #2: Device Manager is part of the Computer Management, which also includes Event Viewer, Services Manager, Disk Management, as well as many other things. Right-Click My Computer then select Manage to start Computer Management, or invoke compmgmt.msc.

See also

• List of Microsoft Windows components
• Microsoft Management Console

External links

Windows-specific articles

NB: not all articles apply to all Windows versions

• Displaying detailed information in Windows XP device manager
• Displaying unconnected devices in Windows XP device manager
• The DevCon utility

For the European kings, see Lothar. For the Moroccan musical instrument, see Lutar

Lotar, an acronym for Lohama Neged Teror (lit. combat against terrorism), is an Israeli set of armed and unarmed self defense techniques. It integrates many modern combat techniques into the baseline techniques of both krav maga and kapap systems.

External links

• “What is LOTAR?” - illustrated article by Avi Nardia at UsaDojo

Future Sound Corporation is an Italian-based hard trance/hardstyle record label fronted by DJ Ben and Radium (who work together as Trance Generators). Artists that have released work through Future Sound include Radium, Trance Generators, Jon The Baptist, Force 9, Atomic Alliance, DJ Chuck-E and The Elite.

See also

• List of record labels

External links

• Official site
• Future Sound Corporation on discogs.com

Soft tissue technique is used in osteopathic manipulative medicine (OMM).

Indications/contraindications

Soft tissue technique is used to resolve dysfunctions commonly described by the mnemonic device “TART” (Tissue texture change, Asymmetry, Restriction, and Tenderness). It is often used in conjunction with other techniques to treat somatic dysfunction. Soft tissue technique is considered to be a direct technique, meaning that the tissue is directly engaged. It is therefore contraindicated for acute injury, wounds, cancer, and in any situation where it might elicit pain.

Techniques

Techniques are generally classified by the orientation of the vector of force in relation to the grain of the tissue being treated, either perpendicular or parallel. For each body segment, there are a variety of techniques in both vectors. It can be administered with the patient in nearly any posture, allowing it to be used in a wide range of situations. Many techniques involve rhythmic engaging of the tissue, massaging the muscle into relaxation. Other techniques simply involve stretching the tissue parallel to its grain.

Sources

Ward, Robert C. et al; Foundations for Osteopathic Medicine (2nd ed.). Philadelphia: Lippincot Williams and Wilkins. ISBN 0-7817-3497-5

The Family Friendly Programming Forum is a coalition of over 40 advertisers, all of whom belong to the Association of National Advertisers. They seek to increase the amount of “family-friendly” programming on U.S. television.

They define family-friendly programming as:

It is relevant to today’s TV viewer, has generational appeal, depicts real life and is appropriate in theme, content and language for a broad family audience. Family friendly programs also embody a responsible resolution. Family friendly programs may include movies, dramas, situation comedies and informational programs.[1]

The FFPF supports various programs and initiatives:

• Script Development Fund
• Student Scholarship Program
• Annual Symposium
• Family Television Awards

The script-development fund has helped several programs reach the pilot stage — including

• Gilmore Girls
• Life Is Wild
• Bionic Woman
• Chuck
• Ugly Betty
• Friday Night Lights
  
• Brothers and Sisters
• Everybody Hates Chris
• Notes from the Underbelly
• Runaway
• Commander in Chief
• Old Christine
• Related
• Complete Savages
• Clubhouse
• 8 Simple Rules for Dating My Teenage Daughter
• American Dreams
• Big Time

The fund has no influence on the direction of the show further than the pilot.

External links

• Official homepage

Ramesh Chand Saxena (born September 20, 1944, Delhi) is a former Indian cricketer who played in one Test in 1967.

Simple Simon is a nursery rhyme which begins:

Simple Simon met a pieman

Going to the fair;

Says Simple Simon to the pieman,

“Let me taste your ware.”

Says the pieman to Simple Simon,

“Show me first your penny.”

Says Simple Simon to the pieman,

“Indeed I have not any.”

Because of this, he became a comic foil in pantomime, most commonly Mother Goose.

Variation

The Three Stooges did a variant version, which began the usual way, and ended this way…

Said de pieman to Simple Simon,

“Foist let me see yah penny.”

Said Simple Simon to de pieman,

“Nah! Ya don’t get any!”

(And a pie in the face)

In the film Die Hard With A Vengeance, the antagonist Simon Gruber, played by Jeremy Irons first lines in the film are a taunt to the police:

“Said Simple Simon to the pie man going to the fair: Give me your pies… or I’ll cave your head in.”

External link

• A page containing the full text of the rhyme

Corridors is a demo by British cinematic industrial black metal band The Axis of Perdition, self-released in 2002. According to the band, only 20 copies were released (presumably because the debut album followed soon, they didn’t distribute many demos)

The demo is actually a split CD with the group’s side project Pulsefear; a dark ambient project which pre-dates The Axis of Perdition. This project was put on hiatus for some time but work started again around the time of the second Axis of Perdition album.

Line up

• Michael Blenkarn - Guitar, Keys, Programming, Sampling, Ambient Discord
• Brooke Johnson - Vocal Corrosion, Industrial Bleakness, Bass, Further Guitar, Sampling

Track listing

1. Axis of Perdition - “To Walk the Corridors of Hell” - (7:17)
2. Axis of Perdition - “Chained in the Damnation Asylum” - (5:49)
3. Axis of Perdition - “Born Under the Knife, Live in Pain” - (6:04)
4. Pulse Fear - “A Figure In The Mist” - (5:27)
5. Pulse Fear - “Lighthouse” - (11:50)
6. Pulse Fear - “Embrasure Of The Dark Aspect” - (2:08)

The loop braid group is a mathematical group structure that is used in some models of theoretical physics to model the exchange of particles with loop-like topologies within three dimensions of space and time.

The basic operations which generate a loop braid group for n loops are exchanges of two adjacent loops, and passing one adjacent loop through another. The topology forces these generators to satisfy some relations, which determine the group.

To be precise, the loop braid group on n loops is defined as the motion group of n disjoint circles embedded in a compact three dimensional “box” diffeomorphic to the three dimensional disk. A motion is a loop in the configuration space, which consists of all possible ways of embedding n circles into the 3-disk. This becomes a group in the same way as loops in any space can be made into a group; first, we define equivalence classes of loops by letting paths g and h be equivalent iff they are related by a (smooth) homotopy, and then we define a group operation on the equivalence classes by concatenation of paths. Dahm was able to show that there is an injective homomorphism from this group into the automorphism group of the free group on n generators, so it is natural to identify the group with this subgroup of the automorphism group (described in a paper by Goldsmith). One may also show that the loop braid group is isomorphic to the welded braid group, as is done for example in a paper by Baez, Crans, and Wise, which also gives some presentations of the loop braid group using the work of Lin.

See also

• Braid group
  

External links

• Braids and Loop Braids

PSR J0737-3039 is a binary pulsar system discovered in 2003, the first known double pulsar.

The object is similar to PSR B1913+16, which was discovered in 1974 by Taylor and Hulse, and for which the two won the 1993 Nobel Prize in Physics. Objects of this kind enable precise testing of Einstein’s theory of general relativity, because relativistic effects can be seen in the timing of the pulsar pulses. However most such binary systems are merely known to consist of one pulsar and one neutron star; J0737-3039 is the first case where both components are known to be not just neutron stars but pulsars.

The orbital period of J0737-3039 (2.4 hours) is the smallest yet known for such an object (one-third that of the Taylor-Hulse object), which enables the most precise tests yet. In 2005, it was announced that measurements had shown an excellent agreement between general relativity theory and observation. In particular, the predictions for energy loss due to gravitational waves appear to match the theory.

As a result of energy loss due to gravitational waves, the common orbit shrinks by 7 mm per day. The two components will coalesce in about 85 million years.

The pulsars

The pulses from Pulsar B are only detectable for about 20 minutes in each orbit.

External links

• http://skyandtelescope.com/news/article_1124_1.asp (discovery)
• http://skyandtelescope.com/news/article_1473_1.asp (verification of general relativity)
• http://www.physicsweb.org/articles/world/18/3/6/1
• http://www.jb.man.ac.uk/news/doublepulsar/