Results 131 to 140 of about 21,767,102 (210)
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Real-time parallel logarithmic filtering
Optics Letters, 1982Parallel logarithmic filtering of multiplicatively combined image signals is achieved in real time. A liquid-crystal light valve (LCLV) is combined with a specially designed halftone screen that matches the LCLV characteristics to produce an overall logarithmic transformation. Experimental results are shown.
A, Armand +3 more
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Time-gated filter for sideband suppression
Optics Letters, 2009A time-gated filter is demonstrated that converts a double-sideband radio-frequency (rf) waveform on a pulsed optically chirped carrier into a single sideband (SSB) waveform. Electrical technology to produce SSB modulation is currently limited to rfs less than 20 GHz, while our filter operates up to the maximum frequency available from optical ...
Jason, Chou +4 more
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Time-Limited Time-Invariant Wiener Filtering
Information Sciences, 1981Abstract For the estimation of a signal observed with additive white noise, it is shown that the optimum linear least-squares filter constrained to have its impulse response time-limited to the interval [0,T] satisfies a truncated version of the Wiener-Hopf equation.
J.M. Potter, B.D.O. Anderson
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ICASSP-88., International Conference on Acoustics, Speech, and Signal Processing, 2003
The author considers the transformation of bilinear time-frequency distributions for the case of a linear time-variant transformation of the signal. The conditions for the output to be representable, that is, for a signal to exist which gives the output distribution, are derived and related to the general question of time-frequency filtering. >
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The author considers the transformation of bilinear time-frequency distributions for the case of a linear time-variant transformation of the signal. The conditions for the output to be representable, that is, for a signal to exist which gives the output distribution, are derived and related to the general question of time-frequency filtering. >
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Time reversed filtering in real-time
IEEE International Symposium on Circuits and Systems, 2002A technique is developed for indirectly realizing true time-reversed convolution for continuous inputs of infinite duration. This real-time technique is based on a novel extension of sectioned convolution methods using an infinite impulse response (IIR) filter and local time reversal using last-in, first-out (LIFO) memory stacks.
S.R. Powell, P.M. Chau
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2019
In Sect. 1.5 we defined filters as operations in continuous time which preserved frequencies. Such operations are important since they can change the frequency content in many ways. They are difficult to use computationally, however, since they are defined for all instances in time. This will now be addressed by changing focus to discrete-time. Filters
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In Sect. 1.5 we defined filters as operations in continuous time which preserved frequencies. Such operations are important since they can change the frequency content in many ways. They are difficult to use computationally, however, since they are defined for all instances in time. This will now be addressed by changing focus to discrete-time. Filters
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1989
In this chapter, we continue the discussion of joint time-frequency energy representations for speech signals. Here we shall make stronger assumptions about the form of the signals. We will introduce a particular model of the time-varying vocal tract, and define its ‘transfer function’, H(t,ω).
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In this chapter, we continue the discussion of joint time-frequency energy representations for speech signals. Here we shall make stronger assumptions about the form of the signals. We will introduce a particular model of the time-varying vocal tract, and define its ‘transfer function’, H(t,ω).
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Photorefractive time correlation filter
Optical Society of America Annual Meeting, 1990Previous photorefractive holographic filters are limited by the response time of the material. The time correlation filter recognizes a sequence of individual temporal features which are limited only by the speed of the phase modulators in the reference and input signals.
V. Ryan +3 more
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Time-multiplexed active filters
IEEE Journal of Solid-State Circuits, 1972The inductorless realization of high-order voltage transfer functions is achieved by subdividing a conventional realization into identical memoryless active subnetworks; the realization is then achieved by time multiplexing one of the memoryless active subnetworks such that it effectively replaces the total number of active subnetworks.
L.T. Bruton, R.T. Pederson
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Discrete-Time Equivalent of Continuous-Time Filtering Processes
Journal of Dynamic Systems, Measurement, and Control, 1981The continuous-time Kalman filtering problem over a finite time interval can be made equivalent to a discrete-time filtering problem. The matrices in the latter are related to the submatrices of the transition matrix of a Hamiltonian system that corresponds to the continuous-time filtering problem.
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