Detection of closely spaced edges in images contaminated by noise is important in medical applications, industrial inspection, advanced TV systems, and image understanding. Laplacian-of-Gaussian (Marr-Hildreth) edge d...
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Detection of closely spaced edges in images contaminated by noise is important in medical applications, industrial inspection, advanced TV systems, and image understanding. Laplacian-of-Gaussian (Marr-Hildreth) edge detectors are known from their tunable resolution to edge spacing. However, when they are tuned for the detection of very closely spaced edges, their noise performance deteriorates. In this paper, a class of nonlinear edge detectors suitable especially for the detection of closely spaced edges is introduced. The detectors are based on a difference between linear and median-type filters and use the principle of zero-crossings. computer simulations indicate that the nonlinear edge detectors perform better in noisy conditions than Marr-Hildreth edge detectors of comparable resolution.
We consider the planning problem for a mobile manipulator system that must perform a sequence of tasks defined by position, orientation, force, and moment vectors at the end-effector. Each task can be performed in mul...
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We consider the planning problem for a mobile manipulator system that must perform a sequence of tasks defined by position, orientation, force, and moment vectors at the end-effector. Each task can be performed in multiple configurations due to the redundancy introduced by mobility. We formulate the planning problem as an optimization problem in which the decision variables for mobility (base position) are separated from the manipulator joint angles in the cost function. The resulting numerical problem is nonlinear with nonconvex, unconnected feasible regions in the decision space. Simulated annealing is proposed as a general solution method for obtaining near-optimal results. The problem formulation and numerical solution by simulated annealing are illustrated for a manipulator system with three degrees of freedom mounted on a base with two degrees of freedom. These results are compared with results obtained by conventional nonlinear programming techniques customized for the particular example system.
Conventional subband coding for image data compression uses two-dimensional (2-D) separable QMF banks in which the analysis and synthesis filters are composed of 1-D filters. Such an implementation produces a large si...
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This paper concerns the supervisory coordination and control of concurrent activity cycles in automated manufacturing facilities. In contrast to commonly used simulation models which integrate the control policy with ...
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This paper concerns the supervisory coordination and control of concurrent activity cycles in automated manufacturing facilities. In contrast to commonly used simulation models which integrate the control policy with the system model, the state transition logic for the manufacturing equipment is represented by a class of controlled Petri nets (CtlPN) with external inputs to be determined by the control synthesis algorithm. We formulate the forbidden state control problem in the CtlPN context and present an algorithm for generating maximally permissive controls which guarantee the system will avoid the forbidden states while permitting a maximal amount of flexibility in the system operation. The problem formulation and control synthesis algorithm is illustrated for an example of AGV co-ordination, and several classes of manufacturing control problems which can be addressed within this framework are identified.
The problem of defining an appropriate measure of the degree of nonstationarity for stochastic processes that exhibit cyclostationarity is addressed. After discussing several candidate measures of degree of nonstation...
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The problem of defining an appropriate measure of the degree of nonstationarity for stochastic processes that exhibit cyclostationarity is addressed. After discussing several candidate measures of degree of nonstationarity, one particularly promising measure is adopted. By decomposing this measure, several component measures are arrived at. Bounds on these measures are derived and their utility in applications involving signal detection and estimation is established. Examples are presented to illustrate the calculation of degrees of nonstationarity for several types of cyclostationary signals.
A new method for detecting dominant points is presented. It does not require any input parameter, and the dominant points obtained by this method remain relatively the same even when the object curve is scaled or rota...
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A new method for detecting dominant points is presented. It does not require any input parameter, and the dominant points obtained by this method remain relatively the same even when the object curve is scaled or rotated. In this method, for each boundary point, a support region is assigned to the point based on its local properties. Each point is then smoothed by a Gaussian filter with a width proportional to its determined support region. A significance measure for each point is then computed. Dominant points are finally obtained through nonmaximum suppression. Unlike other dominant point detection algorithms which are sensitive to scaling and rotation of the object curve, the new method will overcome this difficulty. Furthermore, it is robust in the presence of noise. The proposed new method is compared to the Teh-Chin algorithm (see C. Teh and R. T. Chin, IEEE Trans. Pattern Anal. Mach. Intell. 11, 859-872 (1989)) in terms of the computational complexity, the approximation errors and the number of detected dominant points of an object curve.
We consider the integration problem of LAN/MAN traffic to WAN by ATM/SONET multiplexing. We propose separate buffers for voice and data to efficiently control the throughput of each traffic type. Transmission bandwidt...
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Severe inter-symbol-interference (ISI) due to multipath fading broadcast channels requires the equalization of digital teletext signals for reliable operation. Until now, the equalization of the teletext signals has b...
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Severe inter-symbol-interference (ISI) due to multipath fading broadcast channels requires the equalization of digital teletext signals for reliable operation. Until now, the equalization of the teletext signals has been achieved by conventional adaptive equalization. However, these equalizers need a training signal which is sent during the potential data transmission time. Also, conventional adaptive equalizers are very poor in tracking changing channel characteristics which are often encountered in fading multipath environments. This paper suggests the use of blind adaptive equalization, which removes the mentioned drawbacks of the conventional adaptive equalization. The paper also deals with the compatibility of the proposed blind equalizer with the existing teletext system standards and cost-effectiveness issues. computer simulations demonstrate substantial improvements in the bit-error-rates for the received teletext data in a multipath transmission medium.
This paper addresses the problem of creating software tools for visualizing the dynamic behavior of parallel applications and systems. PARADISE (PARallel Animated Debugging and Simulation Environment) approaches this ...
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Amplitude beating between closely spaced frequency components is a well-known effect in musical acoustics, psychoacoustics, and other fields [l-31. Depending on the musical context and the personal preference of the l...
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