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Creator | Title | Description | Subject | Date |
| 26 |
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Mathews, V. John | Image compression using vector quantization of linear (One-Step) prediction errors | ABSTRACT A novel approach to image compression using vector quantization of linear (one-step) prediction errors is presented in this paper. In order to minimize the image reconstruction error, we choose the optimum predictor coefficients (in a least-squares sense) that satisfy the additional constr... | | 1987 |
| 27 |
 |
Mathews, V. John | Improved convergence analysis of stochastic gradient adaptive filters using the sign algorithm | Abstract-Convergence analysis of stochastic gradient adaptive filters using the sign algorithm is presented in this paper. The methods of analysis currently available in literature assume that the input signals to the filter are white. This restriction is removed for Gaussian signals in our analysis... | | 1987 |
| 28 |
 |
Mathews, V. John | Adaptive filters requiring zero multiplications | This paper introduces an adaptive filter structure that requires zero multiplications for its implementations. The primary input signals are quantized using DPCM and the DPCM outputs are processed by the adaptive filter. The sign algorithm. We show that if the parameters are chosen properly, hardwar... | | 1987 |
| 29 |
 |
Mathews, V. John | A fast recursive least-squares adaptive nonlinear filter | This paper presents a fast, recursive least-squares (RLS) adaptive nonlinear filter. The nonlinearity in the system is modeled using the Hammerstein model, which consists of a memoryless polynomial nonlinearity followed by a finite impulse response linear system. The complexity of our method is abou... | | 1988 |
| 30 |
 |
Mathews, V. John | A new carrier frequency estimator for modem signals | ABSTRACT A novel carrier frequency estimation scheme for a relatively broad class of voiceband data signals (modem signals) is presented in this paper. The class of signals being studied includes different types of phase-shift-keyed (PSK) and frequency-shift-keyed (FSK) signals. The frequency estim... | | 1988 |
| 31 |
 |
Mathews, V. John | A fast recursive least-squares second order volterra filter | ABSTRACT This paper presents a fast, recursive least-squares (RLS) adaptive nonlinear filter. The nonlinearity is modelled using a second order Volterra series expansion. The structure presented in the paper makes use of the ideas of fast RLS multichannel filters and has a computational complexity ... | | 1988 |
| 32 |
 |
Mathews, V. John | A baseband residual vector quantization algorithm for voiceband data signals | Abstract-In this paper, we present a new approach to the digitization and compression of a class of voiceband modem signals. Our approach, which we call baseband residual vector quantization (BRVQ), relies heavily upon the simple structure present in a modem signal. After the signal is converted to... | | 1989 |
| 33 |
 |
Mathews, V. John | Multiplication-free vector quantization using the L l distortion measure and its variants | Vector quantization is a very powerful technique for data compression and consequently, it has attracted a lot of attention lately. One major drawback associated with this approach is its extreme computational complexity. This paper first considers vector quantization that uses the L1 distortion mea... | | 1989 |
| 34 |
 |
Mathews, V. John | Efficient FIR adaptive filter using DPCM and the sign algorithm | This correspondence introduces an adaptive filter structure that requires zero multiplications for its implementation. The primary input signal is quantized using DPCM, and the DPCM outputs are processed by a conventional adaptive filter. The filter coefficients are updated using the sign algorithm.... | | 1989 |
| 35 |
 |
Furse, Cynthia M. | Three-dimensional electromagnetic power deposition in tumors using interstitial antenna arrays | Interstitial arrays of insulated antennas have shown promise for microwave hyperthermia treatment of deep-seated tumors. Available analytical techniques for predicting the electromagnetic (EM) power deposition of these antennas have been limited to the case of a homogeneous conductive medium surrou... | Interstitial antenna arrays; Microwave hyperthermia treatment; Invasive hyperthermia; Electromagnetic power deposition | 1989-10 |
| 36 |
 |
Furse, Cynthia M. | Three-dimensional electromagnetic power deposition in tumors using interstitial antenna arrays | Abstract-Interstitial arrays of insulated antennas have shown promise for microwave hyperthermia treatment of deep-seated tumors. Available analytical techniques for predicting the electromagnetic (EM) power deposition of these antennas have been limited to the case of a homogeneous conductive mediu... | | 1989-10 |
| 37 |
 |
Mathews, V. John | Fixed-point error analysis of stochastic gradient adaptive lattice filters | Abstract-This paper presents a theoretical analysis of the stochastic gradient adaptive lattice filter used as a linear, one-step predictor, when the effects of finite precision arithmetic are taken into account. Only the fixed-point implementation is considered here. Both the unnormalized and norma... | | 1990 |
| 38 |
 |
Mathews, V. John | Tracking analysis of the sign algorithm in nonstationary environments | Abstract-This paper presents a tracking analysis of the adaptive filters equipped with the sign algorithm and operating in nonstationary environments. Under the assumption that the nonstationarity can be modeled using a random disturbance, it is shown that the long-term time average of the mean-abso... | | 1990 |
| 39 |
 |
Mathews, V. John | Tracking analysis of the sign algorithm in nonstationary environments | This paper presents a tracking analysis of the adaptive filters equipped with the sign algorithm and operating in nonstationary environments. Under the assumption that the nonstationarity can be modeled using a random disturbance, it is shown that the long-term time average of the mean-absolute erro... | | 1990 |
| 40 |
 |
Mathews, V. John | Stochastic gradient adaptive filters with gradient adaptive step sizes | This paper presents two adaptive step-size gradient adaptive filters. The step sizes are changed using a gradient descent algorithm designed to minimize the squared estimation error. The first algorithm uses the same step-size sequence for all the filter coefficients whereas the second algorithm use... | | 1990 |
| 41 |
 |
Mathews, V. John | Lattice and QR decomposition-based algorithms for recursive least squares adaptive nonlinear filters | This paper presents a lattice structure for adaptive Volterra systems. The stucture is applicable to arbitrary planes of support of the Volterra kernels. A fast least squares lattice and a fast QR-lattice adaptive nonlinear filtering algorithms based on the lattice structure are also presented. The... | | 1990 |
| 42 |
 |
Furse, Cynthia M.; Gandhi, Om P. | Improvements to the finite-difference time-domain method for calculating the radar cross section of a perfectly conducing target | The finite-difference time-domain (FDTD) method has been used extensively to calculate scattering and absorption from both dielectric objects and perfectly conducting objects. Several improvements to the FDTD method for calculating the radar cross section (RCS) of a perfectly conducting target are p... | Finite-difference time-domain; FDTD | 1990-01-01 |
| 43 |
 |
Furse, Cynthia M.; Gandhi, Om P. | Improvements to the finite-difference time-domain method for calculating radar cross section of a perfectly conducting target | Abstract -The finite-difference time-domain (FDTD) method has been used extensively to calculate scattering and absorption from both dielectric objects and perfectly conducting objects. Several improvements to the FDTD method for calculating the radar cross section (RCS) of a perfectly conducting ta... | Finite-difference time-domain method; FDTD; RCS; Perfectly conducting target | 1990-07 |
| 44 |
 |
Normann, Richard A.; Campbell, Patrick K.; Jones, Kelly E.; Huber, Robert J.; Horch, Kenneth W. | Silicon-based, three-dimensional neural interface: manufacturing processes for an intracortical electrode array | A method has been developed for the manufacture of a "three-dimensional" electrode array geometry for chronic intracortical stimulation. This silicon based array consists of a 4.2 x 4.2 x 0.12 mm thick monocrystalline substrate, from which project 100 conductive, silicon needles sharpened to facilit... | Electric Stimulation; Electrodes, Implanted; Sensory Cortex; Intracortical Electrode Array | 1991 |
| 45 |
 |
Mathews, V. John | Adaptive polynomial filters | While 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 |
| 46 |
 |
Mathews, V. John | Adaptive algorithms for identifying recursive nonlinear systems | ABSTRACT This paper presents two fast least-squares lattice algorithms for adaptive non-linear filters equipped with system models involving nonlinear feedback. Such models can approximate a large class of non-linear systems adequately, and usually with considerable parsimony in the number of coeff... | | 1991 |
| 47 |
 |
Mathews, V. John | Output-error adaptive bilinear filters | This paper presents an overview of several gradient type recursive algorithms for adaptive nonlinear filters equipped with bilinear system models. Bilinear models are attractive because they can approximate a large class of nonlinear systems with great parsimony in the use of coefficients. Two al... | | 1991 |
| 48 |
 |
Mathews, V. John | Performance analysis of adaptive filters equipped with the dual sign algorithm | Adaptive filters equipped with the sign algorithm are attractive in many applications because of their computational simplicity. Unfortunately, their slow speed of convergence is a major limitation. The dual sign algorithm (DSA) is a means by which the convergence speed can be increased without over... | | 1991 |
| 49 |
 |
Mathews, V. John | Parameter estimation for a bilinear time series model | ABSTRACT This paper presents a direct approach to the estimation of the parameters associated with a bilinear time series model. The approach depends critically on the expressions for certain higher-order statistics of the signals that satisfy the bilinear model. These expressions are linear in mo... | | 1991 |
| 50 |
 |
Cotter, Neil E. | Prejudicial search and backprop | This paper introduces the combination of backward error propagation and prejudicial search. Prejudicial search is a method, which like simulated annealing, guarantees convergence to a global minimum as time approaches infinity. Unlike simulated annealing, its application is more flexible because it ... | | 1991 |
