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CreatorTitleDescriptionSubjectDate
51 Mathews, V. John; Nilsson, MichaelAdaptive gain processing to improve feedback cancellation in digital hearing aidsAdaptive filters are commonly used to cancel acoustic feedback in hearing aids. The sound quality of hearing aids deteriorates as the hearing aid gain is increased. This paper presents a method to alter the gain function in digital hearing aids to provide additional amplification and better output ...2008
52 Mathews, V. JohnAdaptive gain processing with offending frequency suppression for digital hearing aidsDigital hearing aids identify acoustic feedback signals and cancel them continuously in a closed loop with an adaptive filter. This scheme facilitates larger hearing aid gain and improves the output sound quality of hearing aids. However, the output sound quality deteriorates as the hearing aid gai...2012
53 Mathews, V. JohnAdaptive lattice bilinear filtersAbstract-This paper presents two fast least squares lattice algorithms for adaptive nonlinear filters equipped with bilinear system models. Bilinear models are attractive for adaptive filtering applications because they can approximate a large class of nonlinear systems adequately, and usually with...1993
54 Mathews, V. JohnAdaptive nonlinear digital filter with sequential regression algorithmThe purpose of this paper is to introduce an adaptive nonlinear digital filtering algorithm which use the sequential regression (SER) method to update the second order Volterra filter coefficients in a recursive way. Conventionally, the SER method has been used to invert large matrices which result ...1984
55 Mathews, V. JohnAdaptive parallel-cascade truncated volterra filtersAbstract-This paper studies adaptive truncated Volterra filters employing parallel-cascade structures. Parallel-cascade realizations implement higher order Volterra systems a s a parallel connection of multiplicative combinations of lower order truncated Volterra systems. A normalized LMS adaptive f...1998
56 Mathews, V. JohnAdaptive phase transform processors for time delay estimationThis paper introduces two recursive realizations of the phase transform (PHAT) processor for time-delay estimation (TDE), using a simple one-pole low-pass filter and the least-mean-square (LMS) adaptive filter, respectively. It is shown that these adaptive methods are capable of tracking time-varyin...1993
57 Mathews, V. JohnAdaptive polynomial filtersWhile linear filter are useful in a large number of applications and relatively simple from conceptual and implementational view points. there are many practical situations that require nonlinear processing of the signals involved. This article explains adaptive nonlinear filters equipped with polyn...1991
58 Mathews, V. JohnAdaptive realization of a maximum likelihood time delay estimatorABSTRACT This paper presents an adaptive maximum likelihood method for estimating the time difference of arrival of a source signal at two spatially separate sensors. It is well-known that the maximum likelihood technique achieves the Cramer-Rao lower bound for time delay estimation error for ce...1996
59 Mathews, V. JohnAdaptive realizations of the maximum likelihood processor for time delay estimationAbstract-This correspondence introduces an adaptive realization of the maximum likelihood (ML) processor for time delay estimation (TDE). Also presented is a modified ML processor, which requires less computations but still performs better than the other when implemented in an adaptive way. Widrow'...1984
60 Mathews, V. JohnAdaptive realizations of the phase transform for time delay estimationABSTRACT This paper introduces two recursive realizations of the Phase Transforn (PHAT) processor for tine delay estimation (TOE), using a simple one-pole lowpass filter and the least mean square (LMS) adaptive filter, respectively. It is shown that these adaptive methods are very effective in redu...1984
61 Mathews, V. JohnAdaptive unsharp masking for contrast enhancementABSTRACT A new scheme o,f unsharp masking for image contrast enhancement is presented in this paper. An adaptive algorithm is introduced so that a sharpening action is performed only in locations where the image exhibits significant dynamics. Hence, the amplification of noise in smooth areas i...1997
62 Mathews, V. JohnAdaptive volterra filters using orthogonal structuresAbstract- This paper presents an adaptive Volterra filter that employs a recently developed orthogonalization procedure of Gaussian signals for Volterra system identification. The algorithm is capable of handling arbitrary orders of nonlinearity P as well as arbitrary lengths of memory N for the sys...1995
63 Mathews, V. JohnAdaptive volterra filters using orthogonal structuresAbstract-This paper presents an adaptive Volterra filter that empolys a recently developed orthogonalization procedure of Gaussian signals for Volterra system identification. The algorithm is capable of handling arbitrary orders of nonlinearity P as well as arbitrary lengths of memory N for the syst...1996
64 Mathews, V. JohnAdaptive, quadratic preprocessing of document images for binarizationAbstract-This paper presents an adaptive algorithm for preprocessing document images prior to binarization in character recognition problems. Our method is similar in its approach to the blind adaptive equalization of binary communication channels. The adaptive filter utilizes a quadratic system mod...1998
65 Simpson, Jamesina J.ADE-FDTD scattered-field formulation for dispersive materialsThis letter presents a scattered-field formulation for modeling dispersive media using the finite-difference time-domain (FDTD) method. Specifically, the auxiliary differential equation method is applied to Drude and Lorentz media for a scattered field FDTD model. The present technique can also be a...2008-01-01
66 Stringfellow, Gerald B.; Shurtleff, James KevinAdsorption and desorption of the surfactant Sb on GaInP grown by organometallic vapor phase epitaxyIt has been determined that ordering has a profound effect on the bandgap energy of many compound semiconductor alloys. Therefore, ordering must be controlled for devices such as solar cells, light emitting diodes and diode lasers. Since ordering depends on the surface properties during organomet...Time dependent surface photoabsorption (SPA); Compound semiconductor alloys2000
67 Tasdizen, TolgaAlgebraic curves that work betterAn algebraic curve is defined as the zero set of a polynomial in two variables. Algebraic curves are practical for modeling shapes much more complicated than conics or superquadrics. The main drawback in representing shapes by algebraic curves has been the lack of repeatability in fitting algebraic...1999
68 Stevens, KennethAlgorithms for MIS vector generation and pruningIgnoring the effect of simultaneous switching for logic gates causes silicon failures for high performance microprocessor designs. The main reason to omit this effect is the run time penalty and potential over-conservatism. Run times are directly proportional to the vector sizes. Efficient algorithm...2006
69 Stevens, KennethAn A-FPGA architecture for relative timing based asynchronous designsThis paper presents an asynchronous FPGA architecture that is capable of implementing relative timing based asynchronous designs. The architecture uses the Xilinx 7-Series architecture as a starting point and proposes modifications that would make it asynchronous design capable while keeping it full...2014-01-01
70 Mathews, V. JohnAn adaptive channel estimator for CDMA systems in multipath fading channelsABSTRACT CDMA systems in multipath fading channels need to estimate channel parameters for coherent detection of the transmitted signals. In this paper we present a simple but effective channel estimation algorithm that can be incorporated into most types of multiuser receivers to obtain good dete...2001
71 Mathews, V. JohnAn analytical model of the perceptual threshold function for multichannel image compressionABSTRACT The human observer is often the final judge of the quality of compressed images. One way to design a compression system that attempts to reduce or eliminate subjective distortions in the coded images is to incorporate a perceptual threshold function model into the compression system. The...1998
72 Myers, Chris J.An asynchronous implementations of the MAXLIST algorithmABSTRACT We present an efficient asynchronous VLSI architecture for calculating running maximum or minimum values over a sliding window. Running maximums or minimums are very useful for many signal and image processing tasks. Our architecture performs the calculation using the MAXLIST algorithm. In...1997
73 Myers, Chris J.; Stevens, KennethAn asynchronous instruction length decoderAbstract-This paper describes an investigation of potential advantages and pitfalls of applying an asynchronous design methodology to an advanced microprocessor architecture. A prototype complex instruction set length decoding and steering unit was implemented using self-timed circuits. [The Revolvi...2001
74 Stevens, Kenneth; Myers, Chris J.An asynchronous instruction length decoderThis paper describes an investigation of potential advantages and pitfalls of applying an asynchronous design methodology to an advanced microprocessor architecture. A prototype complex instruction set length decoding and steering unit was implemented using self-timed circuits. [The Revolving Async...2001
75 Simpson, Jamesina J.An E-J collocated 3-D FDTD model of electromagnetic wave propagation in magnetized cold plasmaA new three-dimensional finite-difference time-domain (FDTD) numerical model is proposed herein to simulate electromagnetic wave propagation in an anisotropic magnetized cold plasma medium. Plasma effects contributed by electrons, positive, and negative ions are considered in this model. The current...2010-01-01
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