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Topic: Discrete time

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	Discrete - Wikipedia, the free encyclopedia
		In topology, a branch of mathematics, a discrete space is a topological space in which all sets are open, and a discrete set is a set of isolated points.
		In discrete mathematics, without notion of continuity, a discrete set is a countable set; this concept is also important for combinatorics, probability theory, and statistical theory.
		In discrete mathematics and in theoretical computer science, the abstract world is usually modeled as a discrete space with discrete time.
	en.wikipedia.org /wiki/Discrete (275 words)

	Discrete mathematics - Encyclopedia.WorldSearch (Site not responding. Last check: 2007-09-11)
		Discrete mathematics, sometimes called finite mathematics, is the study of mathematical structures that are fundamentally discrete, in the sense of not supporting or requiring the notion of continuity.
		Discrete mathematics has become popular in recent decades because of its applications to computer science.
		Concepts and notations from discrete mathematics are useful to study or express objects or problems in computer algorithms and programming languages.
	encyclopedia.worldsearch.com /discrete_mathematics.htm (435 words)

	Discrete time control apparatus - Patent 4791548
		A discrete time control apparatus as recited in claim 1, wherein the sampling/detecting means comprises means for adding the controlled system variable to a disturbance and a measuring unit.
		A discrete time control apparatus as recited in claim 5, further comprising means for selecting the binary mode under transient conditions and the continuous mode under normal operating conditions.
		A discrete time control apparatus as recited in claim 5, wherein the means for distinguishing transient from normal operating conditions further comprises means for comparing a preset value and a value obtained from a measuring unit.
	www.freepatentsonline.com /4791548.html (3709 words)

	Stata Library: Discrete Time Survival Analysis
		Discrete time survival analysis treats time not as a continuous variable, but as being divided into discrete units or chunks.
		We will be able to analyze discrete time data using logistic regression with indicator variables for each of the time periods.
		In order to do discrete time survival analysis we to have as many observations as there are time periods for each patient.
	www.ats.ucla.edu /stat/stata/Library/survival2.htm (795 words)

	Simulink and the DSP Blockset (DSP Blockset)
		The time instants where the signal is defined are called the signal's sample times; traditionally, a discrete signal is considered to be undefined at points in time between these instants.
		Because in these modes a discrete-time signal is defined between sample times, if you sample the signal with a rate or phase that is distinct from the signal's own rate and phase, you still measure meaningful values.
		Simulink offers the ability to shift a signal's sample times by an arbitrary value, which is equivalent to shifting the signal's phase by a fractional sample period.
	www.tau.ac.il /cc/pages/docs/matlab/help/toolbox/dspblks/dspi12.html (969 words)

	DES
		Continuous models are represented through sets of differential equations, and discrete time models through sets of difference equations.
		Discrete event models which use continuous state and continuous time axis differ from continuous models by the fact that only a finite number of state changes may occur within finite time interval depending on instantaneous "events".
		The discrete event system is driven by events, and a typical example of discrete system is a queueing system shown as Figure 2.
	www.acims.arizona.edu /SOFTWARE/devscpp/v41_2.htm (391 words)

	Discrete Time Mechanics
		In those recent papers there is a discussion of time as a quantum process and an explanation of why it is necessarily discrete.
		Time is one of the great enigmas of existence which has been discussed and speculated upon since antiquity.
		Firstly, our ordinary experience of time is that it is continuous: we are not normally aware of any sudden jumps "in time" of the world around us.
	www.maths.nottingham.ac.uk /personal/gaj/discrete.html (740 words)

	Discrete PID Controllers
		To discretise the controller, we need to approximate the integral and the derivative terms to forms suitable for computation by a computer.
		The position of the poles and zeros of the discrete transfer functions depend on the sampling interval used.
		Although this characteristic is not of great significance in PID type algorithms, it becomes important when discrete process models are used directly in the design of digital controllers.
	lorien.ncl.ac.uk /ming/digicont/digimath/dpid1.htm (1030 words)

	Discrete-Time Systems
		The time invariance is defined by considering an input sequence x(n), which
		If the system is time invariant, the response to x(n - D) is equal to
		over time or that produce an output sequence at a rate different from that of
	www.faqs.org /docs/sp/sp-17.html (301 words)

	[No title]
		The time update equations are responsible for projecting forward (in time) the current state and error covariance estimates to obtain the a priori estimates for the next time step.
		The time update equations can also be thought of as predictor equations, while the measurement update equations can be thought of as corrector equations.
		After each time and measurement update pair, the process is repeated with the previous a posteriori estimates used to project or predict the new a priori estimates.
	www.cs.brown.edu /stc/education/course95-96/Kalman-Filters/kalman.html (3083 words)

	Discrete Time
		Discrete time models are used when something behaves in a periodical fashion.
		In the case of 17 and 13 year periodical cicadas, we would think of their populations changing in time steps 17 and 13 years long.
		Maybe a model was working really well for a few years then suddenly it doesn’t work at all.
	www.andrews.edu /~chantel/research/mymodel/time.htm (364 words)

	Computing Papers on Discrete (Site not responding. Last check: 2007-09-11)
		Discrete time models are frequently applied to digital systems where the clock defines the required Discrete steps.
		Discrete math is used, for example, whenever objects are counted, when relationships between finite sets are studied, and when processes involving a finite number of steps are analyzed.
		Both Discrete math courses should be required the first year, just as engineering programs require two semesters of calculus in year one.
	computing.breinestorm.net /Discrete (2739 words)

	Is Space-Time Discrete?
		After matter and light, history is repeating itself for a third time and now it is space-time which is threatened to be reduced to discrete events.
		It has been apparent since early times that there is something different between the mathematical properties of the real numbers and the quantities of measurement in physics at small scales.
		However, such observations and the discovery of quantum theory with its discrete energy levels and the Heisenberg uncertainty principle led physicists to speculate that space-time itself may be discrete as early as the 1930's.
	www.karlin.mff.cuni.cz /~motl/Gibbs/discrete.htm (2783 words)

	Sampling and Discrete Time Fourier Transform (Site not responding. Last check: 2007-09-11)
		This discreteness gives rise to a periodic spectrum in the frequency domain with a period equal to the sampling frequency.
		Notice that the situation here is the "opposite" of the Fourier Series where the signal is periodic in the time domain and the spectrum is discrete in the frequency domain.
		Because the sampled signal is discrete in time, it is convenient to refer to its spectrum as the Discrete Time Fourier Transform (DTFT).
	dspcan.homestead.com /files/Sdtft/dtftintr.htm (205 words)

	Discrete-Time Integrator (Using Simulink) (Site not responding. Last check: 2007-09-11)
		The Discrete-Time Integrator block can be used in place of the Integrator block when constructing a purely discrete system.
		T is the sampling period (delta T in the case of triggered sampling time).
		Although the values are the same, Simulink generates them at slightly different times, which protects your model from these problems.
	www.rdg.ac.uk /ITS/Topic/Graphics/GrGMatl601/Matlab6/toolbox/simulink/ug/discretetimeintegrator.html (1167 words)

	Continuous-time to discrete-time system con- version (Site not responding. Last check: 2007-09-11)
		time physical template can result from measurements on a real physical system.
		model can be expressed as a signal flowchart in discrete time.
		ing to discrete time, the overall effect of the constant is canceled.
	www.faqs.org /docs/sp/sp-20.html (380 words)

	EconPapers: Discrete time hedging errors for options with irregular payoffs
		Abstract: In a complete market with a constant interest rate and a risky asset, which is a linear diffusion process, we are interested in the discrete time hedging of a European vanilla option with payoff function f.
		As regards the perfect continuous hedging, this discrete time strategy induces, for the trader, a risk which we analyze w.r.t.
		Keywords: Discrete time hedging; approximation of stochastic integral; rate of convergence.
	econpapers.repec.org /article/sprfinsto/v_3A5_3Ay_3A2001_3Ai_3A3_3Ap_3A357-367.htm (274 words)

	BLOG@STEFANGEENS.COM (Site not responding. Last check: 2007-09-11)
		What I found remarkable at the time is that in building this framework, she and her colleagues had been working from the perspective of the smallest possible units of space, looking for very simple processes that operate locally.
		But the fact that time may be discrete at a fundamental level — massive though this conceptual shift would be — is only half my point.
		This time, his patients had a problem with their visual perception, in that it sometimes slowed down enormously, so that they no longer perceived their surroundings continuously, but instead as a series of disjointed images, much like a flickering film or even a slideshow.
	www.stefangeens.com /000344.html (1622 words)

	Essays in discrete time asset pricing
		Most discrete time literature uses the beta that results from a regression of an asset's simple returns on various factors to quantify risk.
		I define a discrete time affine process as one where the conditional cumulant generating function is affine in the current state.
		Flow of information is modeled as the discreteness τ in a discrete-time economy.
	repository.upenn.edu /dissertations/AAI3031711 (356 words)

	ipedia.com: Binomial options model Article (Site not responding. Last check: 2007-09-11)
		The model differs from other option pricing models, in that it uses a “discrete-time” model of the varying price over time of financial instruments; the model is thus able to handle a variety of conditions for which other models cannot be applied.
		The Binomial Value is found for each node, starting at the penultimate time step, and working back to the first node of the tree, the valuation date, where the calculated result is the value of the option.
		Similar assumptions underpin both the binomial model and the Black-Scholes model, and the binomial model thus provides a discrete time approximation to the continuous process underlying the Black-Scholes model.
	www.ipedia.com /binomial_options_model.html (891 words)

	[No title]
		This course provides foundational education for students in sampling of continuous-time signals and in time, frequency, and Z-domain descriptions of discrete-time signals and systems.
		The discrete Fourier transform for practical evaluation of a signal’s spectral content and a system’s frequency response.
		Graduates will be able to determine the system eigenresponse and will understand the significance of both the magnitude and the phase response of linear, time-invariant systems.
	www.ee.psu.edu /acadaff/courses/ee351_syllabus.html (582 words)

	Discrete-Time System Analysis
		To perform discrete time convolution, x[n]*h[n], define the vectors x and h with elements in the sequences x[n] and h[n].
		Most of the commands for the continuous time state space representation also work for the discrete time state space.
		for discrete time are used exactly the same way as for the continuous time case discussed in Section 3.F.
	users.ece.gatech.edu /~bonnie/book/TUTORIAL/tut_4.html (1347 words)

	Discrete time systems
		returns the output and state time history in the matrices Y and X. No plot is drawn on the screen.
		sampling time, TFINAL is interpreted as the number of samples.
		time for the discrete approximation to the continuous system.
	www.coe.montana.edu /ee/jpeterson/Matlab_step_response_examples.htm (346 words)

	[No title] (Site not responding. Last check: 2007-09-11)
		In all cases, the up times and repair times are assumed to be exponentially distributed with means 1.0 and 0.5, respectively.
		The timeout and transmission/acknowledgement times are assumed to be exponentially distributed.
		Say the queue lengths were as follows: 2 between times 0.0 and 1.4, 3 between times 1.4 and 2.1, 2 between times 2.1 and 4.9, and 1 between 4.9 and 5.3.
	heather.cs.ucdavis.edu /~matloff/simpy.html (4681 words)

	Prof. Salvatore Monaco - Publications
		Monaco and D. Normand-Cyrot: On the immersion of a discrete time polynomial analytic system into a polynomial affine one; Systems and Control Lett., vol.
		Monaco and D. Normand-Cyrot: Canonical representations of nonlinear discrete time systems; in Systems, Models and Feedback: Theory and Applications, (A. Isidori and T. Tarn Eds.), pp.
		Monaco and D. Normand-Cyrot: Lie exponential formula for the nonlinear discrete time functional expansions, Theory and Applications of Nonlinear Control Systems (C. Byrnes and A. Lindquist Eds.), pp.
	w3.uniroma1.it /monaco/Publications.htm (2787 words)

	Discrete-Time Signal Metrics (Site not responding. Last check: 2007-09-11)
		is the exponential time constant and A is the peak amplitude.
		The time constant is the time it takes for the quantity y(t) to decay by 1/e (i.e.
		Note that a positive time constant will produce a decaying exponential while a negative time constant will produce a growing exponential.
	www.music.mcgill.ca /~gary/307/week1/metrics.html (618 words)

	Discrete time signals
		Generally a time discrete signal is a sequence of real or complex numbers.
		The unit sample is a signal which is zero everywhere except when its argument is zero, then it is equal to 1.
		The unit sample function is very useful in that it can be seen as the elementary constituent in any discrete signal.
	cnx.rice.edu /content/m11476/latest (400 words)

	ECE 4660: Lab 4-Discrete-time modulation and demodulation
		Note: In up and down sampling, be very careful to set the sample rates in each block.
		When available, set the "Sample Time" in the filter blocks to -1.
		Then the filters will "inherit" their sample times from the previous block.
	www.engineering.usu.edu /classes/ece/4660/lab4/lab4.html (857 words)

	Discrete Time and Quantum Cosmology
		My researches on Discrete Time have now entered the phase where questions on cosmology can be considered.
		We simply suppose that the entire universe is described by such a (time dependent) state.
		Likewise, if there were clumps of factor states which more or less retained their configuration as clumps as the state of the universe evolved, we could legitimately start to talk about the "onset of classicity".
	www.maths.nott.ac.uk /personal/jag/future.html (1300 words)

	2.5.1 Discrete Time Markov Chains (DTMCs) (Site not responding. Last check: 2007-09-11)
		The transition probability between state i to state j at time n-1 is the probability
		Throughout this dissertation proposal, we consider time homogeneous DTMCs.
		Each row of the probability transition matrix represents the transition flow out of the corresponding state.
	www.cs.wm.edu /~riska/main/node14.html (487 words)

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