leff@smu.UUCP (Laurence Leff) (05/15/89)
If you would like any of the following, please mail the request with payment to: Lauren Oddo Department of Electrical Engineering Tulane University New Orleans, LA 70118-5674 The format of the following is Authors Title Tech Report Number Date Abstract Cost Ansari, A. and A. B. Martinez A Bayesian Approach to Optimal Quantization for Distributed Detection 88-9 05-19-88 The problem of optimal quantization by a network of distributed sensors is considered. It is shown that the quantization rule at the sensors and the fusion rule at the central processor are coupled. To minimize the cost, a multidimensional search for the parameters is needed. Suboptimal systems are obtained for either a fixed sensor performance or a given fusion rule. Computational complexity reduction is achieved for a restricted case of identical quantization rule at each sensor. $1 Ansari, A. and A. B. Martinez Locally Optimum Quantization for Distributed Detection 88-8 04-22-88 A distributed network of sensors is considered where each sensor quantizes its observation optimally. It is shown that if the global decision test statistic is obtained as the sum of the statistics of each sensor, then the efficacy of the network is maximized by maximizing the efficacy of each sensor. The quantizer minimizing the mean square error between the locally optimum nonlinearity and the quantizer output can, therefore, be used at each sensor. The result is an extension of locally optimum quantization to the multisensor case. $1 Barad, Herb An Object-Oriented Prototype of a Pyramid Architecture for Computer Vision 88-4 03-02-88 This paper describes a working software prototype of a pyramid architecture to investigate its use and effectiveness in computer vision. The results demonstrate that the pyramid architecture is an effective architecture for a wide range of computer vision tasks. An object-oriented methodology for modeling the individual processors and ports is used. The method of modeling and constructing the prototype is efficient and flexible. The prototype is used as a testbed for simulations of computer vision tasks. The segmentation results are presented. Implications of these results are discussed as well as the advantages of using this method of modeling to examine alternative architectures. $2 Barad, Herb Rapid Prototyping of Massively Parallel Architectures 88-10 05-30-88 This paper describes a working software prototype of a pyramid architecture, known as the SCOOP pyramid. The purpose of the prototype is to analyze the effectiveness of the architecture for computer vision work. The SCOOP pyramid was built using Smalltalk. Each functional element of the entire architecture (i.e., processors, internal elements of processors, ports connecting processors, etc.) was modeled using different classes. The SCOOP environment is flexible enough to handle architectures of different topologies and those created from different types of hardware (e.g. optical). The construction of a prototype encourages the fine-tuning of the architecture design. The prototype is used as a test bed for simulations of computer vision tasks and the results of some of these simulations are presented. The SCOOP environment is a paradigm in which one can rapidly prototype architectures of arbitrary topology, complexity, and composition. The pyramid architecture is shown by simulation to be an effective architec- ture for a wide range of computer vision tasks from low level pixel-oriented operations to segmentation to high level symbolic operations. A description of the environment and results of some benchmarks are presented. $2 Barbieri, E. and Umit Ozguner Rest-to-Rest Slewing of Flexible Structures in Minimum Time 88-23 12-08-88 The rest-to-rest slewing of flexible structures in minimum time is considered via phase-plane techniques. The trajectories are shown to satisfy a set of necessary and sufficient conditions for optimality and are shown to exhibit a mirror-image symmetry in the phase plane. The advantage of this solution is that the control law is expressed in terms of the states thereby resulting in a closed-loop strategy. Simulations are included for a 1-bending-mode model of a flexible slewing structure. $1 Barbieri, E. and Umit Ozguner Unconstrained and Constrained Mode Expansions for a Flexible Slewing Link 88-21 12-08-88 The linear equations of motion of a uniform flexible slewing link which were derived via Hamilton's Extended Principle are considered. These equations account for the coupling between bending and rigid modes. Unconstrained and constrained mode expansions are investigated and a quantitative comparison is made between the frequency equations and associated mode shapes. A finite dimensional model is derived using the assumed modes method and the theoretical frequencies are verified with an experimental counterbalanced aluminum beam. $1 Barbieri, E., Umit Ozguner, and S. Yurkovich Vibration Compensation in Optical Tracking Systems 88-22 12-08-88 Modeling and control of multiple-mirror/flexible slewing structures is considered. Primary applications for such systems include Line-Of-Sight point systems on large flexible structures, space telerobotic systems, and space telescope systems. Analysis can be accomplished in a four stage process: 1) Relegation of control tasks; 2) The flexible structure modeling and slewing control problem; 3) Vibration compensation using mirror actuators; and 4) Active vibration damping with additional (structural) actuation. In the present paper the first and third stages of the above process are addressed. Relegation is achieved under the assumption that the optical ray hits the center of the following mirror along the ray path. Vibration compensation is then cast into the framework of a decentralized servocompensator problem. A recently developed optimal solution approach is utilized. A particular system is examined in detail and control simulations are included to illustrate the results. $1 Bergantz, David and Herb Barad Neural Network Control of Cybernetic Limb Prostheses 88-12 06-28-88 CMAC (Cerebellar Model Arithmetic Computer) is a Perception-like neural network that was developed to mimic the functionality of the human cerebellum in complex motor tasks. It is proposed that CMAC-like networks can be used to process the dynamic and concurrent variables involved in the motion of upper-body cyber- netic limb prostheses. An example of a four degree of freedom above elbow prosthesis is provided to illustrate how this approach can be implemented. $1 Bourgeois, Brian S. Specialized Hardware for Digital Signal Processing 88-20 12-08-88 This paper on digital signal processing hardware provides an indoctrination for the casual computer user to some of the more commonly used computer architectures seen in these devices. It begins with a simplified description of a standard von Neumann type processor to provide a contrast to the more sophisticated systems. A description of data dependent algorithm's follows using a multiply operation, a radix-2 FFT algorithm and a matrix-vector multiplication as examples to demonstrate the inherent parallelism that exists in common digital signal processing tasks. Operational descriptions are provided for some of the more commonly used advanced architecture types that take advantage of this parallelism and the paper concludes with descriptions of existing hardware using these architectures. $3 Bruce, R. N., R. L. Drake, C. J. Sperry, and H. A. Thompson Nondestructive Inspection of Cable Stays by Electronic Means 88-6 04-20-88 The research reported here concerns a technique for nondestructive inspection of cable stays for a cable-stayed bridge at Luling, Louisiana. The method uses acoustic pulse transmission through the steel cables. The results of laboratory tests on stay samples and on test cables are described. These results establish the apparent feasibility of the method. Field measurements at the bridge are described. These measurements indicate that the cables tested are free of major faults. Certain difficulties have been encountered in field tests. These are described. Recommendations are made to improve the practicality and the applicability of the proposed method. $1 Cartwright, K. A Note on the Equivalence of the Diagonalized and the MSE Receiver for Larger S/N Ratios and for Any Constellation 88-2 10-17-88 The probability of symbol error performance of the diagonalizer is shown to be the same as that of the MSE receiver for large signal-to-noise ratios and for any constellation. $1 Cartwright, K. A Note on the Probability of Symbol Error for the Diagonalizer 88-1 10-17-88 It is shown analytically that the logarithm of the probability of symbol error for the adaptive diagonalizer is the sum of two terms--a constant term and a sinusoidal term, the latter of which represents the variation of probability of error with the phases of the crosstalk, and the former is dependent upon the magnitude of the crosstalk only. This sum is valid when the crosstalk is less than -10 dB. $1 Cartwright, Kenneth Obtaining the Performance of Cross-Polarized L-QPRS Systems, the Easy Way 88-19 10-25-88 An algebraic method is described which enables a general formula to be derived for the performance of cross-polarized L-QPRS systems which is valid when the desired channel is L-QPRS and the interfering channel's constellation is quadrantly symmetric. $1 Cartwright, Kenneth Obtaining the Performance of Cross-Polarized M-QAM Systems, the Easy Way 88-18 10-25-88 An algebraic method is described which enables a general formula to be derived for the probability of symbol error performance for cross- polarized M-QAM systems. The method is valid when the desired channel's constellation is square M-QAM, and the interfering channel's constellation is quadrantly symmetric. $2 Cartwright, K. Obtaining the Probability of Symbol Error Performance for the MSE Adaptive Baseband Canceller the Easy Way 88-3 10-17-88 An algebraic approach is described which enables a general formula to be derived for the probability of symbol error performance for the MSE adaptive baseband canceller. The method is valid when the desired channel's constellation is square M-QAM and the interfering channel's constellation is quadrantly symmetric. $1 Davey, Jack, Peng Zhang, and R. A. Brossette Generation Investment Responsibility Based Upon Consumer Contribution to Utility Unreliability 88-24 12-08-88 This paper describes a method which results in determining each electricity consumer class' generation investment responsibility based upon each class' contribution to the electric utility's generation system unreliability. The load data used is Louisiana Power & Light Company's (LP&L) hourly total load and each consumer class' contribution to the hourly total load. Loss of Load Expectation (LOLE) and Loss of Energy Expectation (LOEE) are computed on each hour of load experience and responsibility divided among the consumer classes in proportion to their load contribution. The resulting investment responsibilities are compared with traditional "cost of service" study methods. The paper also discusses the applicability of the calculation method to the development of fundamental data for guidance in the formation of demand-side plans for a utility and presents an argument for the appropriateness of the LOEE index. $1 Jaggi, S., A. B. Martinez, H. Silber, and P. V. Moulder An Algorithm for Estimation of Frequencies of Biological Signals Using Adaptive IIR Line Enhancers 88-13 06-28-88 An estimator using an adaptive IIR filter form is used to estimate the frequencies of a biological signal. This signal is the instantaneous ventricular diameter of a dog's heart. This method is found to be more accurate in determining frequency than traditional FFT and periodogram methods. Its high speed of estimation makes it useful as a real-time process. $1 Jaggi, S. and R. L. Drake Process Parameter Identification 88-15 06-28-88 Parameter identification of an unknown linear plant, by obtaining a process model having an input response with a best match to the plant input response, is presented. [TAB]The estimation of the parameters is done by minimizing the error between the actual response of the plant and the estimated value of the response. The effects of choosing various kinds of error functions for minimization, such as Integral Square Error (ISE), Integral Time Square Error (ITSE), and Integral Square Time Square Error (ISTSE), on the speed of convergence and the degree of accuracy of the estimator algorithm, are presented. [TAB]The techniques used for estimation are derived first from the steepest descent optimization method and later from the LMS algorithm. [TAB]System modelling techniques used here include parallel modelling and cascade modelling. $1 Jaggi, S. System Response Design Using Variable Sampling 88-14 06-28-88 A new approach to sampled data system design is considered as an alternative to compensation design techniques. The sampling interval is varied in a cyclic manner. The rela- tionships between this cyclically varying sampling interval and the peak overshoot and the settling time of the step response of the system are investigated. Calculation of the response of a system with variable sampling is usually a cumbersome process. A simpler technique is introduced which adapts easily to numerical computation without the need to analyze the whole system algebraically. $1 Jaggi, S. and A. B. Martinez Upper and Lower Bounds of the Misadjustment in the LMS Algorithm 88-16 07-18-88 The misadjustment is a dimensionless measure of the difference between the optimal Weiner performance and the actual performance of the LMS algorithm. This is attributed to the gradient noise in the adaptive process. Present estimates relate the misadjustment to the convergence gain and the trace of the autocorrelation matrix. This paper establishes tighter lower bounds on the estimate of this misadjustment and an upper bound on the misadjustment as a function of the convergence gain is found. $1 Lee, M. S., B. S. Bourgeois, S. T. Hsieh, and A. B. Martinez A Laser Sensing Scheme for Detection of Underwater Acoustic Signals 88-5 04-15-88 A technique has been developed to detect underwater acoustic signals by utilizing the resultant surface perturbations. These perturbations result in an amplitude modulation effect on a laser beam reflected by the water surface. A theory is proposed to explain this phenomenon. A detection system was developed based on this theory. Laboratory investigations were conducted to evaluate the characteristics of the system. Preliminary results are included and indicate that detection is possible based on this technique. $1 Lee, Michael Su-Hsien The Surface Detection of Underwater Acoustic Signals Using a Helium-Neon Laser 88-11 06-10-88 Master's Thesis. $7 Martinez, Andrew B., Richard T. Joy, Maria K. Kalcic, Greg Terrie, and Stephen P. Haimbach Adaptive Estimation of Water Depth Using Multispectral Remote Sensing 88-7 04-22-88 An adaptive procedure for the estimation of water depth from passive multispectral scanner data is presented. While many authors have proposed nonadaptive, model-based estimators, most are computationally intensive and require accurate estimates of model parameters (directly or through regression) and bottom classification. By using an adaptive estimator based on the LMS algorithm, computational overhead is greatly reduced. Parameter estimation is unnecessary due to the inherent robustness of the algorithm to changes in ocean environment. This results in significant improvements in performance. Examples are given illustrating these points, and comparisons are made of methods based on adaptive estimation and on regression. Trade-offs between rate or convergence and residual error are discussed. $1 Rastgoufard, P. and J. Davey Advancements in Power System Transient Stability Analysis: Past, Present, and Future 88-25 12-08-88 The purpose of this paper is to present an overview of Direct Method Transient Stability Analysis (DMTSA) techniques. These techniques are qualitatively analyzed and practical difficulties encountered in implementation of original and current theoretical developments are outlined. An overview of future DMTSA techniques and the need for a universally-recognized test system for quantitative comparison purposes are discussed in the last sections of the paper. $2 Rastgoufard, Parviz and R. A. Schlueter Determination of Power System Transient Stability via Global Kinetic Energy Accounting 88-28 12-08-88 (no abstract) $1 Rastgoufard, Parviz and R. A. Schlueter Identification of Critical Generators for Power System Direct Transient Stability Analysis 88-26 12-08-88 (no abstract) $1 Rastgoufard, Parviz, R. A. Schlueter, and J. Davey Kinetic Energy and Potential Energy Considerations for Power System Transient Stability Analysis 88-30 12-08-88 (no abstract) $1 Rastgoufard, Parviz and R. A. Schlueter Loss of Power System Stability Due to Sequential Decoupling of Individual Generators of the Critical Group 88-29 12-08-88 (no abstract) $1 Rastgoufard, Parviz, A. Yazdankhah, and R. A. Schlueter Multi-Machine Equal Area Based Power System Transient Stability Measure 88-27 12-08-88 (no abstract) $1 Sperry, C. J. Jr. and H. A. Thompson Luling Bridge Cable Stays First-Mode Frequencies and Tensions, August 16-17, 1988 88-17 09-06-88 Tension in each of the 72 cables making up the cable stays of the Luling-Destrehan Bridge are inferred from measurements of first-mode resonant frequencies and compared with tensions measured in June of 1983. The greatest change in any individual cable tension is a 1.9% decrease. The greatest change in any total stay load is a 1.4% decrease. Since the expected accuracy of the measurement technique is +2%, it is concluded that there has been no significant change in cable stay loads between June 1983 and August 1988. $1 Potlapalli, H., M. Y. Jaisimha, H. Barad, A. B. Martinez, M. C. Lohrenz, J. Ryan, and J. Pollard Classification Techniques for Digital Map Compression 89-1 01-27-89 The performance of image classification techniques as applied to color cartographic maps is compared. These maps have a lot of graininess due to imperfections in the printing process. This graininess decreases the efficiency of compression techniques. The color maps are classified using the K-means clustering algorithm and the vector quantization with neighborhood classification to improve the visual quality and compression ratio. The classification is performed in various image representations schemes. The performance of the classifier is evaluated based on the visual quality of the classified image, the time required to classify the image and compression achieved on the classified image. The compression ratio after classification was higher than before classification. $2 Zhang, Peng, H. Barad, and A. B. Martinez Application of Fractal Modeling to Cell Image Analysis 89-2 01-27-89 The fractal dimension of a surface is a useful measure of the roughness of the surface. A method of estimating fractal dimension using mathematical morphology is derived and is applied to cell image analysis. By utilizing the fractal dimension property, the cells can be automatically classified as labeled or unlabeled cells. $1 -- Herb Barad [Signal & Image Processing Laboratory] [Electrical Engineering Dept. - Tulane Univ.] INTERNET: barad@ee.tulane.edu USENET: barad@bourbon.uucp