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Communications, Power and Computing Conference: WESCANEX

作者： A. Langi W. Kinsner Department of Electrical and Computer Engineering Signal and Data Compression Laboratory and TRLabs (Telecommunications Research Laboratories) University of Manitoba Winnipeg MAN Canada

This paper presents a new and promising approach in characterizing speech consonants using a fractal model for speech recognition systems. Characterization of consonants has been a difficult problem because consonant waveforms may be indistinguishable in time or frequency domain. The approach views consonant waveforms as coming from a turbulent constriction (excitation) in a human speech production system, and thus exhibiting turbulent and noise like time domain appearance. However, it departs from the usual approach by modeling consonant excitation using chaotic dynamical systems capable of generating turbulent and noise-like excitations. The scheme employs correlation fractal dimension and Takens embedding theorem to measure fractal dimension from time-series observation of the dynamical systems. It uses linear predictive coding (LPC) excitation of twenty-two consonant waveforms as the time series. Furthermore, the correlation fractal dimension is calculated using a fast Grassberger algorithm. A preliminary observation shows encouraging results because every consonant results in a unique trend of fractal dimensions for different embedding dimensions and scales.

关键词： Fractals Speech recognition Chaos Noise generators Frequency domain analysis Humans Production systems Time domain analysis Linear predictive coding Data compression

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Modeling and control of a spark ignition engine with variable cam timing

Modeling and control of a spark ignition engine with variabl...

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American control Conference (ACC)

作者： A.G. Stefanopoulou J.A. Cook J.S. Freudenberg J.W. Grizzle M. Haghgooie P.S. Szpak Control Systems Laboratory Department of Electrical Engineering and Computer Science University of Michigan Ann Arbor MI USA Scientific Research Laboratory Ford Motor Company Limited Dearborn MI USA

A control scheme is designed to minimize emissions and respond to rapid throttle changes in a fuel injected, spark ignition engine equipped with variable cam timing. The model is derived from engine mapping data for an eight cylinder experimental engine mounted in a dynamometer test cell; it is fundamentally a nonlinear and multivariable model. The control scheme jointly manages fuel and cam position.

关键词： Sparks Ignition computer aided manufacturing CADCAM Timing Engine cylinders Fuels Valves Torque Exhaust systems

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Consequences of modular controller development for automotive powertrains: a case study

Consequences of modular controller development for automotiv...

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IEEE Conference on Decision and control

作者： A.G. Stefanopoulou K.R. Butts J.A. Cook J.S. Freudenberg J.W. Grizzle Control Systems Laboratory Department of Electrical Engineering and Computer Science University of Michigan Ann Arbor MI USA Scientific Research Laboratory Ford Motor Company Limited Dearborn MI USA

A modular controller structure for automotive powertrains has certain benefits. These include improved productivity through module reuse, seamless integration of new features, transparent removal of obsolete features, and module sharing across powertrain platforms. Modular architecture also potentially reduces the complexity in the design and calibration process, in that controller modules for different subsystems are developed independently. Due to the fact that the automotive powertrain system contains many highly interactive sub-systems, it is not clear that a modular controller development process can yield acceptable feedback controller performance with respect to emissions, fuel economy, and drivability. In this paper, we describe the engineering design issues associated with a decentralized development process, and the impact that the resulting decentralized controller has upon the dynamic response of the feedback system. We describe the possible detrimental consequences of subsystem interaction, and the potential of coordinated, multivariable feedback for alleviating these limitations. control of a spark ignition engine incorporating variable camshaft timing is used as a case study.

关键词： Automotive engineering Mechanical power transmission Process control control systems Feedback Productivity Process design Calibration Adaptive control Fuel economy

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Robust parametrized controller design with an application to exhaust gas recirculation (EGR) system

Robust parametrized controller design with an application to...

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IEEE Conference on Decision and control

作者： A.W. Olbrot M.H. Berri J.R. Asik Department of Electrical and Computer Engineering Wayne State University Detroit MI USA Control Systems Department Scientific Research Laboratory Ford Motor Company Limited Dearborn MI USA

An exhaust gas recirculation (EGR) control system for automotive application is briefly presented. Robustness is one of the main issues in this particular system due to nonlinearities, time delays, and the effects of complex exhaust gas dynamics. It was found that a good approximation of the system dynamics consists of a first order transfer function with a time delay where both transfer function coefficients and the time delay depend on the reference signal (desired EGR(%)). Moreover, it is sufficient to identify only four models corresponding to four different values of desired EGR (%) and assume interpolation for transfer function coefficients to characterize the system dynamics. Since the value of the reference signal is available in real time the controller design can be reduced to four controllers corresponding to four identified models and interpolation for coefficients of the controller transfer function in cases when the value of desired EGR (%) is between the assumed values. Simulation results for such designs are presented.

关键词： Robust control Transfer functions Delay effects Vehicle dynamics Nonlinear dynamical systems Interpolation control systems Automotive applications Robustness Signal processing

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Securing data transfer in asynchronous transfer mode networks

Securing data transfer in asynchronous transfer mode network...

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IEEE Conference and Exhibition on Global telecommunications (GLOBECOM)

作者： R.H. Deng Li Gong A.A. Lazar Institute of Systems Science National University of Singapore Singapore Computer Science Laboratory SRI International Inc. Menlo Park CA USA Department of Electrical Engineering and Center for Telecommunications Research Columbia University New York NY USA

Asynchronous transfer mode (ATM), which can provide integrated services of various media types and bit rates, is rapidly becoming the dominant technology for local and wide area information transport. In this paper we present a network security architecture for secure data transfer in ATM networks. The proposed architecture facilitates seamless integration of security services into the existing ATM architecture and conforms to the ATM B-ISDN PRM: security related signaling functionality, such as mutual end system authentication, establishment of security associations, and cryptographic key distributions are carried out in the control plane, while protection of user traffic is achieved by defining a data protection layer in the user plane.

关键词： Asynchronous transfer mode Data security Information security Protection Intserv networks Bit rate B-ISDN Authentication Cryptography control systems

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Authenticated key distribution and secure broadcast using no conventional encryption: a unified approach based on block codes

Authenticated key distribution and secure broadcast using no...

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IEEE Conference and Exhibition on Global telecommunications (GLOBECOM)

作者： R.H. Deng Li Gong A.A. Lazar Weiguo Wang Institute of Systems Science National University of Singapore Singapore Computer Science Laboratory SRI International Inc. Menlo Park CA USA Department of Electrical Engineering and Center for Telecommunications Research Columbia University New York NY USA

To eliminate the use of conventional encryption and to improve protocol efficiency, one-way hash function based authenticated key distribution protocols have appeared in the literature following two distinct approaches: the first approach employs one-way hash function and bit-wise XOR operation; while the second approach makes use of one-way hash function and polynomial interpolation. In this paper, we present a new technique for constructing one-way hash function based protocols for authenticated key distribution. The technique makes use of systematic linear block codes in error-control coding theory, results in more efficient protocols compared with their counterparts in the literature, and in effect, unifies the above two approaches in designing such protocols. As a by product, a secure broadcast protocol is also given which is capable of distributing a data message of any size in one broadcast protocol message.

关键词： Broadcasting Protocols Block codes Polynomials Public key cryptography Authentication computer science Laboratories Data security System performance

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OPTIMUM FREQUENCY REUSE IN MOBILE TELEPHONY SYSTEMS

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INTERNATIONAL JOURNAL OF COMMUNICATION SYSTEMS 1995年第3期8卷 185-190页

作者： KAZANTZAKIS, MG DEMESTICHAS, PP ANAGNOSTOU, ME National Technical University of Athens Computer Science Division Department of Electrical and Computer Engineering Heroon Polytechneiou 9 Zografou Athens 15773 Greece Michael G. Kazantzakii was born in Athens Greece in 1962. He received both the Diploma and Ph.D. Degree from the Electrical Engineering Department of the National Technical University of Athens in 1986 and 1992 respectively. During the period 1992–1993 he was a member of the Staff of the Hellenic Navy Research Centre working in the area of underwater acoustics. Since 1994 he has been a researcher at the National Technical University of Athens Department of Electrical Engineering and Computer Science Telecommunications Laboratory. His interests include data mobile and integrated services networks. Panagiotis P. Demestichas was born in Athens Greece in 1967. He received the Diploma in electrical engineering from the National Technical University of Athens (NTUA) Athens in 1993. At present he is a research assistant at NTUA working towards his Ph.D. dissertation. He participated in the BRITE/EURAM-EURATN and in the RACE-TOMQAT and MONET projects. His research interests are in the areas of broadband and mobile networks queueing theory algorithms and complexity theory. He is a Member of the Technical Chamber of Greece. Miltiades E. Anagnostou was born in Athens in 1958. He received the Electrical Engineers Diploma from the National Technical University of Athens (NTUA) in 1981. During the period 1981–1987 he was a teaching assistant at NTUA. In 1987 he received his Ph.D. in the area of computer networks. In 1987–1989 he served the Greek army in the Air Force Research and Development Center. In 1989–1991 he was a Lecturer and since 1991 he has been an Assistant Professor in the Computer Science Division Department of Electrical and Computer Engineering of the NTUA. He teaches courses on modern telecommunications formal specification of protocols stochastic processes and queueing theory. Since 1981 Dr. Anagnostou has been involved

The reason why cellular mobile telephony systems exist is that they allow frequency reuse. Dynamic allocation algorithms improve the network efficiency and the service quality. Dynamic allocation is closely related to the following instantaneous allocation problem: given a number of channels (frequencies), a cell structure and the number of calls to be accommodated in each cell, find the optimum allocation of channels to cells subject to restrictions concerning the distance of cells, where the same frequency can be reused. In this paper we formulate and solve this problem by showing that it can be reduced to a 0-1 programming problem. Finally we present results, and draw subsequent conclusions.

关键词： MOBILE TELEPHONY FREQUENCY ALLOCATION UMTS

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NETWORK PLANNING BASED ON VIRTUAL PATH BANDWIDTH MANAGEMENT

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INTERNATIONAL JOURNAL OF COMMUNICATION SYSTEMS 1995年第2期8卷 143-153页

作者： LOGOTHETIS, M KOKKINAKIS, G Wire Communications Lab. Electrical Engineering Dept. University of Patras 261 10 Patras Greece Michael D. Logothetis was born in Andros Greece in 1959. He received the Dipl.-Eng. and Ph.D. degrees in electrical engineering both from the University of Patras PatradGreece in 1981 and 1990 respectively. From 1982 to 1990 he was a Teaching and Research Assistant at the laboratory of Wire Communications University of Patras and participated in many national research programmes and three EEC projects (ESPRIT LRE) dealing with telecommunication networks as well as with natural language processing. From 1991 to 1992 he was Research Associate in NTT's Telecommunication Networks Laboratories. Since 1992 he has been a Lecturer in the Department of Electrical Engineering University of Patras Greece. His research interests include traffic control network management simulation and performance optimization of telecommunication networks. He is a member of the IEEE (Commun. Society-CNOM) IEICE and the Technical Chamber of Greece (TEE). George K. Kokkinakis was born in Chios Greece in 1937. He received the Diploma in Electrical Engineering (Dipl.-Ing.) in 1961 the Doctor's Degree in Engineering (Dr.-Ing) in 1966 and the Diploma in Engineering Economics (Dipl. Wjrt.-Ing) in 1967 all from the Technical University of Munich Germany. Since 1969 he has been with the Department of Electrical Engineering at the University of Patras where he has organGed and directing the Wire Communications Laboratory (WCL). His current activity in research and development which coincides with the activity of WCL includes the design and optimization of telecommunication networks and the analysis synthesis recognition and linguistic processing of the Greek language. He has published several books and over 100 technical papers articles and reports on Telecommunications Electrotechnology and Speech Technology. Prof. Kokkinakis is a senior member of IEEE and a member of the Technical Chamber of Greece (TEE) the VDE (Vere

Periodical performance evaluation and adaptive resource assignment, already proposed as performance-oriented management, seems to be the most suitable strategy for network planning under demand uncertainty. In this paper, we exploit the inherent capability of ATM networks to rearrange dynamically the already installed resources, and propose performance-oriented management combined with virtual path bandwidth (VPB) control for the planning of the extensions of bandwidth capacities of virtual paths (VPs) and transmission links of the network. We define a large network optimization problem and solve it by a rigorous, analytical procedure. The optimization model comprises specific requirements of the network-planning problem and a bandwidth distribution scheme ensuring network reliability. We reveal the efficiency of the proposed scheme by applying it on a model network, considering two realistic case-studies of network-traffic evolution. We show that in the presence of VPB control: (a) the initial distribution of the total bandwidth to VPs is of no importance, since it can be adaptively rearranged according to the offered traffic, (b) the network is well used and bandwidth investment could be saved, and (c) whenever additional bandwidth must be installed in VPs which have an unanticipated bad grade-of-service, time savings result. We present the network performance in detail, in figures, and compare this with the performance of the network in the absence of VPB control.

关键词： NETWORK PLANNING NETWORK OPTIMIZATION BANDWIDTH control MATHEMATICAL PROGRAMMING VIRTUAL PATH CALL BLOCKING PROBABILITY ATM

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Adaptive multiuser detector for synchronous code division multiple access applications 13th

Adaptive multiuser detector for synchronous code division mu...

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13th International Zurich Seminar on Digital Communications, 1994

作者： Siveski, Zoran Bar-Ness, Yeheskel Chen, David W. Center for Communications and Signal Processing Electrical and Computer Engineering Department New Jersey Institute of Technology University Heights NewarkNJ07102 United States Delft University of Technology Faculty of Electrical Engineering Telecommunications and Traffic-Control Systems Group Delft Netherlands Center for Communications and Signal Processing Research NJIT NewarkNJ07102 United States

ISBN: (纸本)9783540578567

A two-stage multiuser detector for the code division multiple access environment employing a combination of a decorrelator and a nonlinear multiuser interference canceler is considered. The weights of the canceler are adaptively adjusted, thus rendering the knowledge of the received signal energies unnecessary. The probability of error is evaluated and compared to those of the decorrelator and a similar two-stage, fixed-weights scheme which requires an estimation of signal energies. © Springer-Verlag Berlin Heidelberg 1994.

关键词： Code division multiple access

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Adaptive control of flexible-link manipulators with piezoelectric ceramic sensors and actuators 1

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IFAC Proceedings Volumes 1994年第14期27卷 593-598页

作者： Farshad Khorrami Control/Robotics Research Laboratory (CRRL) School of Electrical Engineering & Computer Science Polytechnic University Six Metrotech Center Brooklyn NY 11201

Active control of flexible multi-body systems and structures through utilization of smart materials is considered in this paper. Specifically, utilization of piezoceramics for sensing and actuation is investigated. Experimental setups have been developed at CRRL to study modeling issues and control design approaches for flexible structures with embedded (or surface-mounted) piezoceramics. In this paper, experimental results on vibration suppression for a flexible manipulator with surface mounted piezoceramics are presented. It will be shown that piezoceramics substantially improve the performance of the systems under consideration. The advocated approaches for control designs are decentralized frequency shaping and self-tuning adaptive controllers. The self-tuning controller is based on identification of the system dynamics in frequency domain utilizing Fast Fourier Transform (FFT). Addition of a self-tuning regulator enhances the performance and the robustness of the controlled system to parameter variations.

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