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Power control using two-level channel inversion for data traffic in a cellular CDMA system: performance and optimal design

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International Journal of Wireless Information Networks 2000年第3期7卷 115-132页

作者： Ding, Ling Lehnert, James S. Sch. of Elec. and Comp. Engineering Purdue University 1285 Electrical Engineering Building West Lafayette IN 47907-1285 United States Coordinated Science Laboratory University of Illinois Urbana IL United States Motorola Communications Schaumburg IL United States Data Systems Research Laboratory Harris Corporation Melbourne FL United States Dept. of Elec. and Comp. Engineering Purdue University West Lafayette IN United States

In this paper, we propose and analyze a simple adaptive uplink power control scheme, called two-level channel inversion, for data traffic in a cellular CDMA system. The basic idea is to reduce out-cell interference by reducing the rate of, or even suspending, transmission when the wireless channel is in a bad condition. We first describe the scheme in detail, and then present a probabilistic analysis model for evaluating the system performance. With this model, we determine the queueing delay and system throughput. Numerical results show that in comparison with the traditional channel inversion scheme, the two-level channel inversion scheme can substantially improve system throughput at a moderate cost of extra queueing delay. Finally, we present a design algorithm to optimize the overall performance while maintaining each user's quality of service (QoS).

关键词： Wireless telecommunication systems

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An architecture of small-scaled neuro-hardware using probabilistically-coded pulse neurons

An architecture of small-scaled neuro-hardware using probabi...

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作者： Kawashima, T. Ishiguro, A. Okuma, S. Research Laboratories Denso Corporation Minamiyama Komenoki-cho Nissin470-0111 Japan Dept. of Computational Science and Engineering Nagoya University Furo-Cho Chikusa-ku Nagoya464-8603 Japan Emergent Soft Computer Project Nagoya Industrial Science Research Institute Anaga-hora Shimoshidami Moriyama Nagoya463-0003 Japan

We present an architecture of a neuro-hardware that can be realized on a small-scaled circuit compared to the conventional approach. In order to reduce the scale of the circuits, the architecture employs a new method of computing the membrane potential and sigmoid function by encapsulating the probability properties into relative delay between two pulses. The proposed architecture enables one to integrate more than one hundred of neurons on a latest FPGA chip, which means thirteen-fold miniaturization compared to the conventional architecture. © 2000 IEEE.

关键词： Delay circuits

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An approximate search engine for structural databases 00

An approximate search engine for structural databases

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Proceedings of the 2000 ACM SIGMOD international conference on Management of data

作者： Jason T. L. Wang Xiong Wang Dennis Shasha Bruce A. Shapiro Kaizhong Zhang Qicheng Ma Zasha Weinberg Dept. of CIS NJIT NJ Courant Institute of Mathematical Sciences New York University New York NY Experimental and Computational Biology Lab National Cancer Institute Frederick MD Dept. of Computer Science University of Western Ontario London Ontario N6A 5B7 Canada Dept. of Computer Science & Engineering University of Washington Seattle WA

ISBN: (纸本)9781581132175

When a person interested in a topic enters a keyword into a Web search engine, the response is nearly instantaneous (and sometimes overwhelming). The impressive speed is due to clever inverted index structures, caching, and a domain-independent knowledge of strings. Our project seeks to construct algorithms, data structures, and software that approach the speed of keyword-based search engines for queries on structural databases.A structural database is one whose data objects include trees, graphs, or a set of interrelated labeled points in two, three, or higher dimensional space. Examples include databases holding (i) protein secondary and tertiary structure, (ii) phylogenetic trees, (iii) neuroanatomical networks, (iv) parse trees, (v) molecular diagrams, and (vi) XML documents. Comparison queries on such databases require solving variants of the graph isomorphism or subisomorphism problems (for which all known algorithms are exponential), so we have explored a large heuristic space.

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Fractional factorial design of genetic coding for aerodynamic optimization 14th

Fractional factorial design of genetic coding for aerodynami...

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14th computational Fluid Dynamics Conference, 1999

作者： Oyama, Akira Obayashi, Shigeru Nakahashi, Kazuhiro Hirose, Naoki Tohoku University Sendai Japan National Aerospace Laboratory Tokyo Japan Dept. of Aeronautics and Space Engineering Japan Computational Science Division Japan

Evolutionary Algorithms (EAs) based on structured coding have been proposed for aerodynamic optimization of wing design. Fractional factorial design is used to investigate interactions of the design variables to determine the appropriate coding structure for EAs in advance. To improve efficiency and accuracy of this approach, parameterization techniques of airfoil shapes are first tested through reproduction of a NASA supercritical airfoil. Their performance is also examined by performing aerodynamic design optimization coupled with a two-dimensional Navier-Stokes code. Finally, three-dimensional wing design is optimized based on a potential flow code and the design result is presented. © 1999 American Institute of Aerhnautics and Astronautics, Inc., 1999. AU rights reserved.

关键词： NASA

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A study on culturing of neurons on micro-electrode array in hybrid retinal implant 6

A study on culturing of neurons on micro-electrode array in ...

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6th International Conference on Neural Information Processing, ICONIP 1999

作者： Ito, Yuichiro Yagi, Tohru Kanda, Hiroyuki Tanaka, Saijiro Watanabe, Masami Uchikawa, Yoshiki Dept. of Computational Science and Engineering Nagoya University Furo-cho Chikusa-ku Nagoya464-8603 Japan Dept. of Physiology Institute for Developmental Research Aichi Colony 713-8 Kamiya-cho Kasugai480-0392 Japan

ISBN: (纸本)0780358716

We are developing a visual prosthesis named a "hybrid retinal implant" for blind patients. In this prosthesis, it is necessary to develop a stimulating micro-electrode array which is implanted into the eyes, to culture the neurons on it and to guide their axons toward the central nervous system (CNS). We have developed electrodes which were fabricated using micro-machining technology. In a culture experiment, the dorsal root ganglion neurons of an adult rat were cultured on the array, and the axon guidance was tested by means of the concentration gradient of the nerve growth factor (NGF). The results showed that the neurons on the array extended their processes, and the NGF facilitated the extension. However, it failed to guide the axons toward the particular direction. Because the proper gradient was not organized in a low-viscosity collagen, the NGF could spread over the dish. Therefore, in future, a high-viscosity collagen will be used in order to make a suitable gradient. © 1999 IEEE.

关键词： Neurons

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Dynamic view-dependent partitioning of structured grids with complex boundaries for object-order rendering techniques

Dynamic view-dependent partitioning of structured grids with...

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1999 IEEE Symposium on Parallel Visualization and Graphics, PVGS 1999

作者： Burton, Lance C. Machiraju, Raghu Reese, Donna S. NSF Engineering Research Center for Computational Field Simulation Dept. of Computer Science Mississippi State University P.O. Box 9627 Mississippi StateMS39762 United States

ISBN: (纸本)1581132379

Object-order rendering techniques present an attractive approach to run-time visualization of structured grid data, particularly when combined with a parallel rendering paradigm such as image composition. The ability of this combination to exploit hardware exceeds that of parallel image order methods. However, certain configurations of grid boundaries prevent composition from being performed correctly. In particular, when the boundary between two partitions contains concave sections, the partitions may no longer be dept. sorted correctly, a requirement for some visualization techniques such as direct volume rendering. This occurs because the concave boundary prevents even the simple ordering of two adjacent partitions. If the data may be repartitioned such that it can be dept. sorted correctly, then an image composition approach is a viable option. To facilitate such an operation, we present an algorithm to analyze the geometric structure of a grid boundary and extract knowledge about how the boundary impacts dept. sorting and therefore image composition. We then show through examples how this knowledge may be applied to create a set of partitions that may be properly dept. sorted.

关键词： Visualization

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Preface

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Lecture Notes in Computer science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) 2000年 1803卷 6-6页

作者： Cagnoni, Stefano Poli, Riccardo Li, Yun Smith, George Corne, David Oates, Martin Hart, Emma Lanzi, Pier Luca Boers, Egbert J. W. Paechter, Ben Fogarty, Terence C. University of Parma Department of Computer Engineering Parco delle Scienze 181/a Parma Italy The University of Birmingham School of Computer Science Edgbaston Birmingham United Kingdom University of Glasgow Electronics and Electrical Engineering Rankine Building Glasgow United Kingdom University of East Anglia Department of Information Systems Norwich United Kingdom University of Reading P.O. Box 225 Whiteknights Reading United Kingdom BT Labs at Adastral Park Dept. Complex Systems Laboratory Martlesham Heath Suffolk United Kingdom University of Edinburgh Division of Informatics 80 South Bridge Edinburgh United Kingdom Milan Polytechnic Department of Electronics and Informatics Piazza Leonard0 da Vinci 32 Milan Italy National Aerospace Laboratory NLR Data and Knowledge Systems Dept I.C.T. Division Anthony Fokkerweg 2 Amsterdam Netherlands Napier University School of Computing 219 Colinton Road Edinburgh United Kingdom South Bank University School of Computing Information Systems and Mathematics 103 Borough Road London United Kingdom

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3-D hypersonic inlet optimization using a genetic algorithm 34th

3-D hypersonic inlet optimization using a genetic algorithm

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34th AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit, 1998

作者： Chernyavsky, B. Stepanov, V. Rasheed, K. Blaize, M. Knight, D. Gas Dynamics Department of Central Institute of Aviation Motors Dept. Mechanical and Aerospace Engineering Rutgers University Moscow Central Institute of Aviation Motors Russia Rutgers University Dept. of Computer Science and Center for Computational Design New Brunswick Rutgers University NJ United States Dept. of Mechanical and Aerospace Engineering Center for Computational Design New Brunswick Rutgers University NJ United States

A numerical code has been developed for automatic aerodynamic optimization of supersonic 3- D inlet design with a high value of total pressure recovery coefficient with the aid of an improved Genetic Algorithm (GADO). The code combines GA and simple 1-D flow solver to form an optimization loop. The code is intended for optimization of inlet geometry, based on one optimization criteria and set of variable optimizing parameters. The code has been tested on a model problem considering optimization of Trexler-type 3-D inlet for Mach number range from 3 to 8. The optimizing parameters have been wedge panel angles and wedge leading edge sweep angle, determining inlet geometry. Total pressure recovery was used as an optimization criteria. The dependencies of wedge panel angles, wedge leading edge sweep angle and Mach number on total pressure recovery coefficient have been studied. Optimum inlet configurations have been obtained and compared for different number of wedge panels and Mach numbers in a range from 3 to 8. The influence of the turbulent boundary layer separation restriction on the integral inlet characteristics has been studied and obtained results have been compared for cases both with and without account for flow separation criteria. Calculations have shown, that account for turbulent boundary layer separation with the use of Gedd criterion significantly decrease expected inlet performance. © 1998 by Boris Chernyavsky, Vladimir Stepanov, Khaled Rasheed, Michael Blaize and Doyle Knight.

关键词： Mach number

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Reducing data Hazards on Multi-pipelined DSP Architecture with Loop Scheduling

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Journal of VLSI Signal Processing Systems for Signal, Image, and Video Technology 1998年第2期18卷 111-123页

作者： Tongsima, Sissades Chantrapornchai, Chantana Sha, Edwin H.-M. Passos, Nelson L. Dept. of Comp. Sci. and Engineering University of Notre Dame Notre Dame IN 46556 United States Dept. of Computer Science Midwestern State University Wichita Falls TX 76308 United States King Mongkut Institute of Technology Ladkrabang Thailand University of Notre Dame United States Dept. of Comp. Sci. and Engineering University of Notre Dame United States Thammasat University Bangkok Thailand Northeastern University Boston MA United States National Taiwan University Taipei Taiwan Department of Computer Science Princeton University Princeton NJ United States University of Notre Dame Notre Dame IN United States Dept. of Comp. Sci. and Engineering University of Sao Paulo Brazil Control Data Corporation Greece University of North Dakota United States Midwestern State University Department of Computer Science Wichita Falls TX United States

Computation intensive DSP applications usually require parallel/pipelined processors in order to meet specific timing requirements. data hazards are a major obstacle against the high performance of pipelined systems. This paper presents a novel efficient loop scheduling algorithm that reduces data hazards for such DSP applications. This algorithm has been embedded in a tool, called SHARP, which schedules a pipelined data flow graph to multiple pipelined units while hiding the underlying data hazards and minimizing the execution time. This paper reports significant improvement for some well-known benchmarks showing the efficiency of the scheduling algorithm and the flexibility of the simulation tool.

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Fuzzy inference networks: An introduction

Fuzzy inference networks: An introduction

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1997 IEEE International Conference on Neural Networks (ICNN 97)

作者： Pedrycz, W Smith, MH Computational Intelligence Laboratory Dept. of Electrical and Computer Engineering University of Manitoba Winnipeg R3T 2N2 Canada Dept. of Elecuical Engineering and Computer Science University of California Berkeley United States

ISBN: (纸本)0780341236

One of the problems of existing fuzzy - neural approaches is that the logic nature of the structure is often lost, i.e., what is being processed by the neural networks becomes irrelevant. To retain this logic content while benefiting from the advantage of integrating fuzzy set and neural network approaches, we propose in this paper a fuzzy neural network which supports fuzzy inference mechanisms by being based exclusively on logic implication neurons. A supervised learning method involving an equality performance measure and an on-line update delta rule (gradient - based) learning procedure is used. An experimental study involving Wolfer's sunspot numbers is carried out, demonstrating fast convergence accompanied by explicit format of the inference network.

关键词： Fuzzy inference

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