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Proceedings of the conference on Visualization '00

作者： Henk Huitema Robert van Liere Center for Mathematics and Computer Science Amsterdam CWI Department of Software Engineering P.O. Box 94097 1090 GB Amsterdam Netherlands

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Exact analysis of equal-gain diversity systems over fading channels

Exact analysis of equal-gain diversity systems over fading c...

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IEEE Conference on Vehicular Technology (VTC)

作者： A. Annamalai Jing Su C. Tellambura Bradley Department of Electrical and Computer Engineering Virginia Polytechnic Institute and State University Falls Church VA USA Mobile Communications Technology Center Mitsubishi Wireless Communications San Diego CA USA School of Computer Science and Software Engineering Monash University Clayton VIC Australia

Performance evaluation of equal-gain (EG) diversity systems is notoriously difficult-a classical problem dating back to Lord Rayleigh himself almost a century ago. A number of references to this problem and to its difficulty can be found in the research literature and textbooks. In this paper, we derive exact analytical expressions for the EG receiver performance in Rayleigh, Rician, Nakagami-m and Nakagami-q fading channels in terms of the Appell hypergeometric function. Our methodology and analytical framework can readily handle any order of diversity as well as arbitrary fading statistics (including mixed-fading). The method also applies to a broad class of coherent, differentially coherent and noncoherent modulation formats. For coherent BPSK and BFSK, the solution is particularly simple because a desirable exponential integral representation for the Gaussian probability integral is available.

关键词： Fading Diversity reception Rayleigh channels Modulation Closed-form solution Rician channels Frequency domain analysis Error probability Mobile communication Communications technology

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Little-JIL/Juliette: a process definition language and interpreter

Little-JIL/Juliette: a process definition language and inter...

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International Conference on software engineering (ICSE)

作者： A.G. Cass A.S. Lerner E.K. McCall L.J. Osterweil S.M. Sutton A. Wise Laboratory for Advanced Software Engineering Research Department of Computer Science University of Massachusetts Amherst MA USA University of Massachusetts Amherst Amherst MA US HP Laboratories Palo Alto CA USA IBM Thomas J. Watson Research Center Hawthorne NY USA

Little-JIL, a language for programming coordination in processes is an executable, high-level language with a formal (yet graphical) syntax and rigorously defined operational semantics. The central abstraction in Little-JIL is the step, which is the focal point for coordination, providing a scoping mechanism for control, data and exception flow and for agent and resource assignment. Steps are organized into a static hierarchy, but can have a highly dynamic execution structure including the possibility of recursion and concurrency. Little-JIL is based on two main hypotheses. The first is that coordination structure is separable from other process language issues. Little-JIL provides rich control structures while relying on separate systems for resource, artifact and agenda management. The second hypothesis is that processes are executed by agents that know how to perform their tasks but benefit from coordination support. Accordingly, each Little-JIL step has an execution agent (human or automated) that is responsible for performing the work of the step. This approach has proven effective in supporting the clear and concise expression of agent coordination for a wide variety of software, workflow and other processes.

关键词： Resource management Laboratories computer science Humans Permission Communication system control High level languages Centralized control Control systems computer languages

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Measure-driven

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Journal of software Maintenance and Evolution 2000年第1期12卷 47-78页

作者： Cantone, Giovanni Dept. Info. Syst. Prod. Mgmt. Eng. University of Rome at Tor Vergata Roma Italy Dept. Info. Syst. Prod. Mgmt. Eng. University of Rome at Tor Vergata S.N.C. Roma Italy Department of Computer Science Dept. Info. Syst. and Prod. Mgmt. Faculty of Engineering Italy Scientific-Technical Committee Admin. and Docum. Computing Center University of Rome at Tor Vergata Roma Italy University of Naples University of Maryland Italy Intl. Software Eng. Research Network Italy UMD Exp. Software Engineering Group Italy Ital. Assoc. Info. Automat. Comp. Italy Faculty of Engineering University of Naples Italy

This paper reports on an on-going project undertaken within the University of Rome at Tor Vergata to automate the business processes of a class of administrative organizations. The experience gained and the lessons learned, while performing in the role of Innovation-driver, are abstracted and presented. In the context of this experience with process re-engineering, the paper compares the utility of empirically investigating software technology transfer with the reuse of technology measurement models possibly available. The paper also discusses the roles played by various environmental factors - technology, experimentation and measurements, an organization's business objectives, and other organizational issues, including the expected benefits and costs - in the empirical investigation of software technology transfer. The paper concludes by presenting a short case study and three lessons learned. Copyright © 2000 John Wiley and Sons, Ltd.

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On the implementation of the Opus coordination language

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Concurrency and Computation: Practice and Experience 2000年第4期12卷

作者： Erwin Laure Matthew Haines Piyush Mehrotra Hans Zima Institute for Software Technology and Parallel Systems University of Vienna Liechtensteinstrasse 22 A-1090 Vienna Austria Department of Computer Science University of Wyoming Laramie WY 82071-3682 U.S.A. Institute for Computer Applications in Science and Engineering NASA Langley Research Center Mail Stop 132C Hampton VA 23681-0001 U.S.A.

Opus is a new programming language designed to assist in coordinating the execution of multiple, independent program modules. With the help of Opus, coarse grained task parallelism between data parallel modules can be expressed in a clean and structured way. In this paper we address the problems of how to build a compilation and runtime support system that can efficiently implement the Opus constructs. Our design considers the often-conflicting goals of efficiency and modular construction through software re-use. In particular, we present the system requirements for an efficient Opus implementation, the Opus runtime system, and describe how they work together to provide the underlying services that the Opus compiler needs for a broad class of machines. Copyright © 2000 John Wiley & Sons, Ltd.

关键词： Opus task parallelism data parallelism coordination

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Visualization and performance prediction of multithreaded Solaris programs by tracing kernel threads

Visualization and performance prediction of multithreaded So...

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International Symposium on Parallel Processing

作者： M. Broberg L. Lundberg H. Grahn Department of Software Engineering and Computer Science Soft Center University of Karlskrona Ronneby Ronneby Sweden

Efficient performance tuning of parallel programs is often hard. We present a performance prediction and visualization tool called VPPB. Based on a monitored uni-processor execution, VPPB shows the (predicted) behaviour of a multithreaded program using any number of processors and the program behaviour is visualized as a graph. The first version of VPPB was unable to handle I/O operations. This version has, by an improved tracing technique, added the possibility to trace activities at the kernel level as well. Thus, VPPB is now able to trace various I/O activities, e.g., manipulation of OS internal buffers, physical disk I/O, socket I/O, and RPC. VPPB allows flexible performance tuning of parallel programs developed for shared memory multiprocessors using a standardized environment; C/C++ programs that uses the thread package in Solaris 2.X.

关键词： Visualization Kernel Yarn Operating systems Libraries Spinning Probes Hardware software engineering computer science

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Empirical studies of evolving systems

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Empirical software engineering 1999年第4期4卷 370-380页

作者： Bennett, K. Burd, E. Kemerer, C. Lehman, M.M. Lee, M. Madachy, R. Mair, C. Sjoberg, D. Slaughter, S. Department of Computer Science University of Durham United Kingdom Katz Graduate School of Business University of Pittsburgh United States Department of Computing Imperial College United Kingdom Department of Informatics and Simulation RMCS Cranfield University United Kingdom Litton Guidance and Control Systems USC Center for Software Engineering United States Design Engineering and Computing University of Bournemouth United Kingdom Department of Informatics University of Oslo Norway Graduate School of Industrial Administrations Carnegie Melon University United States

This paper describes the results of the working group investigating the issues of empirical studies for evolving systems. The groups found that there were many issues that were central to successful evolution and this concluded that this is a very important area within software engineering. Finally nine main areas were selected for consideration. For each of these areas the central issues were identified as well as success factors. In some cases success stories were also described and the critical factors accounting for the success analyzed. In some cases it was later found that a number of areas were so tightly coupled that it was important to discuss them together.

关键词： software engineering

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Transient analysis of minimum duration outage for RF channel in cellular systems

Transient analysis of minimum duration outage for RF channel...

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IEEE Conference on Vehicular Technology (VTC)

作者： Yue Ma J.J. Han K.S. Trivedi Center for Advanced Computing and Communication (CACC) Department of Computer Science Duke University Durham NC USA Corporate Software Technology Center Schaumburg IL USA Center for Advanced Computing and Communication (CACC) Department of Electrical and Computer Engineering Duke University Durham NC USA

Following Mandayam et al. (1998), we define outage events as the channel being attenuated for at least a deterministic period of time, /spl tau//sub m/. Compared with a continuous time Markov chain or discrete time Markov chain, a semi-Markov process (SMP) is general enough that it allows the sojourn time to be any distribution function. In this paper, we develop a minimum duration outage model based on an SMP. Closed-form expressions are derived for the time dependent and steady state probabilities of outage. Describing the outage event in the transient regime, our model can reflect the channel fading behavior in a dynamic way.

关键词： Transient analysis Radio frequency Steady-state Markov processes Closed-form solution Fading Land mobile radio cellular systems Power system modeling Communication system software computer science

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A channel recovery method for RF channel failure in wireless communications systems

A channel recovery method for RF channel failure in wireless...

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IEEE Conference on Wireless Communications and Networking

作者： Yue Ma J.J. Han K.S. Trivedi Department of Computer Science Duke University Durham NC USA Corporate Software Technology Center Motorola Inc. Schaumburg IL USA Department of Elec. & Comput. Engineering Duke University Durham NC USA

An RF channel at a cell is assigned to a call during the call set-up process. The channel is dedicated to the subscriber until the call is terminated (normal termination) or the subscriber leaves the cell (handoff). However, the RF channel may fail due to equipment failure or environment changes (failure-termination). In order to increase system end-to-end availability, an RF channel recovery method is proposed in this paper. When an RF channel fails, the channel is replaced by another working channel and the call continues. The method to replace failed RF channels of ongoing calls and to handle channel failures of handoff and new calls is investigated. The numerical results show that the recovery scheme reduces the dropped calls and the blocked calls significantly under both light and normal traffic. In addition, the numerical results for the recovery model and the pure performance model are nearly the same, which indicates that the recovery scheme can almost eliminate the dropped/blocked calls caused by channel impairment.

关键词： Radio frequency Wireless communication Telecommunication traffic Degradation Availability Performance analysis Stochastic processes software packages computer science Equipment failure

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Automatic adjustment system for the optical head of a magnetooptical disk drive

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Systems and computers in Japan 1999年第10期30卷 1-12页

作者： Matsueda, Jun Oosawa, Fujio Sutou, Kazumi Kikuchi, Takahiro Tamano, Michio Koezuka, Tetsuo Furukawa, Yasuo Corp. Mfg. Engineering Systems Group Fujitsu Ltd. Kawasaki 211-8588 Japan Fujitsu Automation Ltd. Oyama 323-0042 Japan Fujitsu Laboratories Ltd. Atsugi 243-0197 Japan Department of Computer Science University of Electro-Communications Fujitsu 1st Commun. Software Co. Fujitsu Ltd. Corp. Mfg. Engineering Systems Group Department of Mathematics Nihon University Fujitsu 1st Commun. Software Ltd. Fujitsu Automation Ltd. 2nd Business Center

A fully automatic adjustment system for mass production of the optical head for magnetooptical disk drives is described. The optical head is composed of millimeter scale optical components, such as laser diode, the collimator lens, the object lens, various prisms and various detectors. A series of algorithms composed of measurement, recognition, calculation of manipulation, execution of manipulation, verification and fixation ensures proper adjustment of the head. The key is to process the measured value, recognize the shape of the beam and the waveform, and determine the manipulation. With this system, the adjustment process is reduced to 6 minutes, as compared to 9 hours it takes an experience worker.

关键词： Optical disk storage

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