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International Conference on Universal Personal Communications

作者： F. Harris Communications and Signal Processing Laboratory Department of Electrical and Computer Engineering San Diego State University San Diego CA USA

Gain and phase mismatch between the two signal processing paths of an I-Q receiver are responsible for artifacts which limit the dynamic range of a communication system. We describe and demonstrate a technique to adaptively balance the gain and phase of the I-Q paths with DSP based balancing loops which operate as background tasks while processing input data.

关键词： Digital filters Signal processing Digital signal processing Frequency Sparse matrices Laboratories Dynamic range Gain Temperature Blind equalizers

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A system for vehicle classification from range imagery

A system for vehicle classification from range imagery

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Southeastern Symposium on System Theory

作者： Shiquan Peng C.A. Harlow Department of Electrical and Computer Engineering and Remote Sensing and Image Processing Laboratory Louisiana State University Baton Rouge LA USA

ISBN: (纸本)0818673524

In this project we consider automated vehicle location and classification systems. Current systems which utilize loop detectors or video cameras have deficiencies. Video based systems are sensitive to environmental conditions and do not perform well in vehicle classification. The new generation of range or distance sensors that are being developed offer the promise of sensors which are not sensitive to lighting conditions and provide information which should give better vehicle detection and classification percentages than current systems. The focus of this project is to develop an automated vehicle location and classification system based upon imagery obtained from range sensors. Image analysis operators and classification methods are developed for vehicle classification. Preliminary results indicate that accurate vehicle classification can be obtained.

关键词： Vehicle detection Radar detection Sensor systems Costs Infrared detectors Laser radar Image processing Road transportation Machine vision Surveillance

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Path planning the processing of titanium matrix composites

Path planning the processing of titanium matrix composites

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IEEE Conference on Control Technology and Applications (CCTA)

作者： R. Vancheeswaran D.G. Meyer H.N.G. Wadley Intelligent Processing of Materials Laboratory Materials Science and Engineering University of Virginia Charlottesville VA USA Electrical and Computer Engineering Department University of Colorado Boulder CO USA

The high temperature consolidation of fiber reinforced titanium matrix composites (TMCs) seeks to reduce the concentration of matrix pores (i.e. increase relative density) while simultaneously minimizing fiber microbending/fracture and the growth of reaction product layers at the fiber-matrix interface. These three goals have conflicting dependencies upon the consolidation processes variables (temperature and pressure), and "trial and error" has had difficulty in identifying optimal process pathways that lead to composites with the least fiber damage, reaction layer thickness and matrix porosity. Here, model predictive control (MPC) concepts have been combined with dynamic consolidation models to investigate the design of locally optimal process cycles that minimize fiber damage, reaction product layer thickness and pore concentration. The approach is used to path plan the input process schedules for a Ti-6Al-4V/SCS-6 TMC system. We then show how useful process windows (i.e. an approximation to the domain of the reachable goals) can be computed by varying the goal and repeating the path planning procedure.

关键词： Path planning Titanium Thermal spraying Hip Plasma temperature Fatigue Plasma materials processing Composite materials Creep Pressing

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Semi-automatic extraction of vascular networks in angiograms

Semi-automatic extraction of vascular networks in angiograms

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Annual International Conference of the IEEE engineering in Medicine and Biology Society (EMBC)

作者： K. Haris S.N. Efstratiadis N. Maglaveras C. Pappas Laboratory of Medical Informatics Faculty of Medicine Aristotle University of Thessaloniki Thessaloniki Greece Information Processing Laboratory Department of Electrical & Computer Engineering Aristotle University of Thessaloniki Thessaloniki Greece

A semi-automatic algorithm for the segmentation of angiographic images is proposed. First, the digital angiogram is smoothed by an image structure preserving technique which is based on homogeneity testing and anisotropic diffusion. Then, the watershed transform is applied to the smoothed image gradient magnitude and the resulting initial image partition is input to a fast hierarchical region merging process. Finally, the vessel regions are extracted from the segmented image by a simple point-and-click interactive procedure. Experimental results on Digital Subtracted Angiograms (DSA) are presented.

关键词： Intelligent networks Image segmentation Testing Anisotropic magnetoresistance Smoothing methods Noise reduction Merging Pixel Filters Data mining

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Design of optimal digital FIR filters with arbitrary magnitude and phase responses

Design of optimal digital FIR filters with arbitrary magnitu...

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IEEE International Symposium on Circuits and Systems (ISCAS)

作者： L.J. Karam J.H. McClellan Telecommunications Research Center Department of Electrical Engineering Arizona State University Tempe AZ USA Digital Signal Processing Laboratory School of Electrical and Computer Engineering Georgia Institute of Technology Atlanta GA USA

This paper presents a new multiple-exchange ascent algorithm for designing optimal Chebyshev digital FIR filters with arbitrary magnitude and phase specifications. Compared to existing Chebyshev design techniques, the new design algorithm exhibits faster convergence while maintaining high accuracy, and is guaranteed to converge to the optimal solution. In addition, the proposed algorithm reduces to the classic second Remez (Parks-McClellan) algorithm when real-only or imaginary-only filters are designed and is, therefore, a true generalization of the classic Remez algorithm to the complex case.

关键词： Finite impulse response filter Digital filters Chebyshev approximation Algorithm design and analysis Signal processing algorithms Frequency response Electronic mail Design optimization Filtering Robustness

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SOI material technology using plasma immersion ion implantation

SOI material technology using plasma immersion ion implantat...

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IEEE SOI-3D-Subthreshold Microelectronics Technology Unified Conference (S3S)

作者： X. Lu S.S.K. Iyer J. Min Z. Fan J.B. Liu P.K. Chu C. Hu N.W. Chueng Plasma Assisted Materials Processing Laboratory Department of Electrical Engineering and Computer Sciences University of California Berkeley CA USA Department of Physics and Materials Science City University of Hong Kong Hong Kong China

Silicon on insulator (SOI) devices have many attractive applications in integrated circuit technology. The high cost of manufacturing the SOI wafers, however, prevents it from being widely accepted for mass production. Separation by plasma implantation of oxygen (SPIMOX), an extremely high through-put SIMOX formation process using plasma immersion ion implantation (PIII) has demonstrated promising results. In this paper, an improvement on the SPIMOX process is presented. High-dose implantation is a costly procedure for the "smart cut" process. A low cost, high through-put implantation by hydrogen or helium plasma is demonstrated as a feasible, novel process for SOI technology using PIII.

关键词： Materials science and technology Plasma immersion ion implantation Silicon on insulator technology Costs Integrated circuit technology Manufacturing Mass production Plasma applications Plasma devices Plasma materials processing

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Interference mitigation in orthogonal frequency division multiplexing (OFDM)

Interference mitigation in orthogonal frequency division mul...

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International Conference on Universal Personal Communications

作者： R.W. Lowdermilk F.J. Harris Communications and Signal Processing Laboratory Department of Electrical and Computer Engineering San Diego State University San Diego CA USA Advanced Development Operations Lockheed Martin Corporation San Diego CA USA

Orthogonal frequency division multiplexing (OFDM) is a modulation scheme purported to be insensitive to the multipath effects of a mobile communication channel as well as exhibiting immunity to narrow-band interference via hole punching in the OFDM spectrum. We examine and verify the OFDM bit error rate sensitivity to low level interference and introduce and demonstrate a spectrum spreading technique to reduce the effect of the narrow-band interferer.

关键词： Interference OFDM modulation Pulse modulation Pulse shaping methods Frequency domain analysis Signal processing Narrowband Bit error rate Demodulation Fast Fourier transforms

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Detection of the complex amplitude distribution of a kinoform using an iterative Fourier-transform algorithm

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ELECTRONICS AND COMMUNICATIONS IN JAPAN PART II-ELECTRONICS 1996年第1期79卷 11-21页

作者： Akahori, H Faculty of Engineering Kanagawa Institute of Technology Atsugi Japan 243-02 Graduated in 1963 from the Department of Electrical Engineering Tokyo Institute of Technology and joined the Electrotechnical Laboratory of the Ministry of International Trade and Industry. Later he obtained a Dr. of Eng. degree. In 1987 he became a Professor in the Department of Information and Computer Sciences Kanagawa Institute of Technology. He has been engaged in research on optical information processing and digital holography.

This paper presents a method for recovering, by using the iterative Fourier-transform algorithm, the complex amplitude transmittance of a recorded one-dimensional Fourier transform-type kinoform. A method for estimating the phase-recording characteristic of the kinoform fabrication system by comparing the retrieved phase with the theoretical phase is also presented. The spatial variations of both the magnitude and phase inside each of the kinoform cells were evaluated to improve estimation of the phase-recording characteristic. The initial estimate of the kinoform phase given to the algorithm was derived using the knowledge that the recorded phase is an approximation of the phase to be recorded. The relationship between the shift of the central sampling point of the Fourier image from the optical axis and the retrieved phase of the kinoform is investigated;a kinoform phase pattern with a structure suitable for indirectly detecting the shift is then proposed. In an experiment using a kinoform fabrication system including a photographic process, the recorded phase distribution is retrieved at five sampling points of each cell. The phase-recording characteristic is estimated using the retrieved phase values. Next, a computer simulation is executed to reveal the influence of errors in the measurement of magnitude. The simulation result shows that the recorded phase distribution can approximately be retrieved when the rms error added to the magnitude is approximately 10 percent of its average. Furthermore, the validity of the phase distribution retrieved in the experiment is discussed.

关键词： Kinoform Gerchberg-Saxton algorithm phase retrieval phase-recording characteristic

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A hypermedia-based design image database system using a perceptional link method

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Journal of Management Information Systems 1996年第3期13卷 25-43页

作者： Shibata, Y. Fukuda, M. Katsumoto, M. University of California Los Angeles CA United States Computer Science Department United States Bell Communication Research United States Dept. of Info. and Computer Science Toyo University Japan ACM Info. Processing Society of Japan Inst. Electron. Commun. Eng. Japan Japan Toyo University Japan Department of Electrical Engineering IPSJ Japan Communication Research Laboratory Japan. Min. P. and Telecommunication Japan IPSJ IEICE IEEE Computer Society Japan

We introduce a hypermedia-based distributed design image database system that can provide simple and flexible user access capabilities based on the "kansei" link method. As proof of this concept, we have developed a prototype distributed multimedia information network incorporating the DHS model. Dubbed the Textile Design Image Database System (TDIDS), this database aids designers using apparel computer-aided design (CAD) systems in different locations, collaborating or working separately, in the design of clothes, including kimonos. Our purpose has been to create a database that will allow each designer to make the best use of his or her creativity and originality-his or her "style and sensitivity to beauty," or, in Japanese, kansei. In our hypermedia system, "metanodes" are defined as abstract nodes that are dynamically organized by multimedia objects, while "metalinks" are defined as flexible kansei links. Metanodes and metalinks are combined to organize a dynam ic hypermedia space from which users can easily retrieve desired design image objects by querying a knowledge agent. The knowledge agent, utilizing the knowledge base, creates links from kansei word objects provided by the user to suitable design image objects among those stored on multimedia databases distributed across the network. The knowledge agent also performs query conversion of individual users' subjective kansei (idiosyncratic, subjective use of kansei words) into objective kansei words using each user's own "user model," These objective kansei words are then converted to equivalent color values. Color value is the means by which all stored design images are characterized. This dynamic linking of kansei word objects to equivalent design images allows individual users' kansei to influence the retrieval process. The sophisticated and flexible CAD systems of the future will require multimedia database systems with cooperative supporting capabilities similar to our kansei system.

关键词： Design databases Hypermedia Image datatbases Perceptional retrieval

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Texture segmentation using hierarchical wavelet decomposition

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PATTERN RECOGNITION 1995年第12期28卷 1819-1824页

作者： Salari, E Ling, Z Computer Vision and Image Processing Laboratory Department of Electrical Engineering University of Toledo Toledo OH 43606 U.S.A.

This paper presents a texture segmentation algorithm based on a hierarchical wavelet decomposition. Using Daubechies' four-tap filter, an original image is decomposed into three detail images and one approximate image. The decomposition can be recursively applied to the approximate image to generate a lower resolution of the pyramid. The segmentation starts at the lowest resolution using the K-means clustering scheme and textural features obtained from various sub-bands. The result of segmentation is propagated through the pyramid to a higher resolution with continuously improving the segmentation. The lower resolution levels help to build the contour of the segmented texture, while higher levels refine the process, and correct possible errors.

关键词： Texture segmentation Wavelet transform Clustering algorithm Multiresolution segmentation

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