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4th IEEE international symposium on High-Assurance Systems Engineering, HASE 1999

作者： Whalen, Michael W. Heimdahl, Mats P.E. Dept. of Comput. Sci. and Eng. Minnesota Univ. MinneapolisMN55455 United States

ISBN: (纸本)0769504183

Although formal requirements specifications can provide a complete and consistent description of a safety-critical software system, designing and developing production quality code from high-level specifications can be a time-consuming and error-prone process. Automated translation, or code generation, of the specification to production code can alleviate many of the problems associated with design and implementation. However, current approaches have been unsuitable for safety-critical environments because they employ complex and/or ad-hoc methods for translation. In this paper we discuss the issues involved in automatic code generation for high-assurance systems and define a set of requirements that code generators for this domain must satisfy. these requirements cover the formality of the translation, the quality of the code generator, and the properties of the generated code. © 2017 IEEE.

关键词： Specifications

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the logical abstract machine: A Curry-Howard isomorphism for machine code 4th

The logical abstract machine: A Curry-Howard isomorphism for...

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4th Fuji international symposium on Functional and Logic Programming (FLOPS 99)

作者： Ohori, A Kyoto Univ Math Sci Res Inst Kyoto 6068502 Japan

ISBN: (纸本)354066677X

this paper presents a logical framework for low-level machine code and code generation. We first define a calculus, called sequential sequent calculus, of intuitionistic propositional logic. A proof of the calculus only contains left rules and has a linear (non-branching) structure, which reflects the properties of sequential machine code. We then establish a Curry-Howard isomorphism between this proof system and machine code based on the following observation. An ordinary machine instruction corresponds to a polymorphic proof transformer that extends a given proof with one inference step. A return instruction, which turns a sequence of instructions into a program, corresponds to a logical axiom (an initial proof tree). Sequential execution of code corresponds to transforming a proof to a smaller one by successively eliminating the last inference step. this logical correspondence enables us to present and analyze various low-level implementation processes of a functional language within the logical framework. For example, a code generation algorithm for the lambda calculus is extracted from a proof of the equivalence theorem between the natural deduction and the sequential sequent calculus.

关键词： Differentiation (calculus)

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On the requirements of high-integrity code generation

On the requirements of high-integrity code generation

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IEEE international Symposim on High Assurance Systems Engineering

作者： M.W. Whalen M.P.E. Heimdahl Department of Computer Science and Engineering University of Minnesota Minneapolis MN USA

关键词： Natural languages Software safety Software systems Formal specifications Production systems Computer science Design engineering Error correction codes Hardware design languages Specification languages

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IMD compensation for CDMA through FEC coding and nonlinearity recovery technique for optical fiber feeder system

IEEE Symposium on Computers and Communications - Proceedings

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IEEE symposium on Computers and Communications - Proceedings 1999年 382-387页

作者： Yaqub, Raziq P. Keio Univ Yokohama Japan

Optical Feedering between Base Stations (BS) and Radio Network Controller (RNC), proposed in this paper, is an efficient technique for third generation wideband CDMA mobile communication systems. the proposed technique provides the compensation to the Intermodulation Distortions (IMD) instituted by both, Power Amplifier (an electrical component), and Laser Diode (an optical component). these IMDs can impose strong limitations on CDMA and deteriorate system performance. In this paper IMD compensation is proposed through unification of FEC codes and Post Nonlinearity Recovery Block (PNRB). System Performance is evaluated through calculating the transfer functions of FEC codes, laser diode and PNRB. Transfer functions of FEC codes are calculated by using the flow graph rules, and of laser diode and PNRB through Voltera Kernels. Performance of PNRB alone for narrow band CDMA signals was sought in our previous work, whereas performance of PNRB combined with digital coding protection to compensate the nonlinearities of Diode (LD) and Power Amplifier (PA) for wideband CDMA is pursued here.

关键词： code division multiple access

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4th international symposium on Solving Irregularly Structured Problems in Parallel, IRREGULAR 1997

4th International Symposium on Solving Irregularly Structure...

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4th international symposium on Solving Irregularly Structured Problems in Parallel, IRREGULAR 1997

ISBN: (纸本)3540631380

the proceedings contain 23 papers. the special focus in this conference is on Discrete Algorithms, Programming Environments and Implementations. the topics include: Parallel mesh generation;efficient massively parallel quicksort;practical parallel list ranking;on computing all maximal cliques distributedly;a probabilistic model for best-first search BandB algorithms;programming irregular parallel applications in cilk;a variant of the biconjugate gradient method suitable for massively parallel computing;efficient implementation of the improved quasi-minimal residual method on massively distributed memory computers;programming with shared data abstractions;supporting run-time parallelization of DO-ACROSS loops on general networks of workstations;engineering diffusive load balancing algorithms using experiments;comparative study of static scheduling with task duplication for distributed systems;a new approximation algorithm for the register allocation problem;improving cache performance through tiling and data alignment;a support for non-uniform parallel loops and its application to a flame simulation code;performance otimization of combined variable-cost computations and I/O;parallel software caches;communication efficient parallel searching;parallel sparse cholesky factorization and unstructured graph partitioning for sparse linear system solving.

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optimization of code rate and spreading factor for direct-sequence CDMA systems

Optimization of code rate and spreading factor for direct-se...

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IEEE 4th international symposium on Spread Spectrum Techniques and Applications (IEEE ISSSTA 96)

作者： Bickel, M Granzow, W Schramm, P Univ of Erlangen-Nuernberg Erlangen Germany

ISBN: (纸本)0780335678

In direct-sequence CDMA, code rate and spreading factor are parameters of the transmission system that can be traded with each other in order to optimize its performance and implementation complexity. In this paper, we investigate the bit error rate performance of convolutionally encoded direct-sequence spread spectrum transmission schemes where the code rate and spreading factor are varied while the transmission bandwidth and interleaving delay are kept constant. It is shown that for coherent demodulation schemes decreasing code rate improves the performance even if very simple channel estimation is used. In contrast, for noncoherent and differential demodulation schemes no gain can be achieved when the code rate is decreased below 1/3.

关键词： Mobile radio systems

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Proceedings of the 1996 4th international symposium on Spread Spectrum Techniques & Applications, ISSSTA'96. Part 1 (of 3)

Proceedings of the 1996 4th International Symposium on Sprea...

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Proceedings of the 1996 4th international symposium on Spread Spectrum Techniques & Applications, ISSSTA'96

the proceedings contains 88 papers from the IEEE Fourth international symposium on Spread Spectrum Techniques & Applications. Topics discussed include: detection and characterization of direct-sequence spread spectrum (DS/SS) signals;application specific integrated circuit in DS/SS-code division multiple access (CDMA) receivers;programmable wideband signal generation and matched filtering;Nakagami multipath fading channels;wideband spatial mobile radio channel models;spread spectrum cellular communication;multi-carrier CDMA;ultra-wideband impulse radar;constant false alarm rate (CFAR) radar imaging detection;polyphase coded continuous wave radar;commutation signaling simulation;and Rayleigh fading mobile radio channels.

关键词： Spread spectrum communication

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Modal testianalysis correlation of space station structures using nonlinear sensitivity

Modal testianalysis correlation of space station structures ...

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4th symposium on Multidisciplinary Analysis and optimization, 1992

作者： Gupta, Viney K. Newell, James F. Berke, Laszlo Armand, Sasan Rocketdyne Division Rockwell International Corporation 6633 Canoga Avenue P.O. Box 7922 Canoga ParkCA91309-7922 United States NASA-Lewis Research Center ClevelandOH44135 United States

the modal correlation problem is formulated as a constrained optimization problem for validation of finite element models (FEMs). For large-scale structural applications, a pragmatic procedure for substructuring, model verification, and system integration is described to achieve effective modal correlation. the space station substructure FEMs are reduced using Lanczos vectors and integrated into a system FEM using Craig-Bampton component modal synthesis. the optimization code is interfaced with MSCJNASTRAN to solve the problem of modal testJana1ysis correlation;that is, the problem of validating FEMs for launch and on-orbit coupled loads analysis against experimentally observed frequencies and mode shapes. An iterative perturbation algorithm is derived and implemented to update nonlinear sensitivity (derivatives of eigenvalues and eigenvectors) during optimizer iterations, which reduced the number of finite element analyses. © 1992 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved.

关键词： Space stations

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Design and optimization of materials handling dust control systems

Design and optimization of materials handling dust control s...

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Simultaneus Convening of the 4th international Conference on Bulk Materials Storage, Handling and Transportation and the 7th international symposium on Freight Pipelines

作者： Fish, K.A. Mclean, A.G. Basu, A. Blue Circle Southern Cement Ltd

this paper presents aspects or an investigation into dust containment and collection within the cement clinker handling facilities at Blue Circle Southern Cement's Berrima Plant, New South Wales. Aspects covered include, economic, social and environmental issues, principles of dust generation, conveyor transfer point design, dust control equipment selection and system design and operational requirements. these aspects are highlighted by reference to actual dust generation sources, plant problems and plant upgrade proposals and installations. Furthermore, the need for direct involvement of plant personnel to achieve sustainable long term dust control is emphasized.

关键词： Dust control

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Generic abstract interpretation algorithms for prolog: Two optimization techniques and their experimental evaluation 4th

Generic abstract interpretation algorithms for prolog: Two o...

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4th international symposium on Programming Language Implementation and Logic Programming, PLILP 1992

作者： Englebert, Vincent Le Charlier, Baudouin Roland, Didier Van Hentenryck, Pascal University of Namur 21 rue Grandgagnage NamurB-500C Belgium Brown University Box 1910 ProvidenceRI02912 United States

ISBN: (纸本)9783540558446

the efficient implementation of generic abstract interpretation algorithms for Prolog is reconsidered after [12, 14]. Two new optimization techniques are proposed and applied to the original algorithm of [12]: dependency on clause prefixes and caching of operations. the first improvement avoids reevaluating a clause prefix when no abstract value which it depends on has been updated. the second improvement consists of caching all operations on substitutions and reusing the results whenever possible. the algorithm together with the two optimization techniques have been implemented in C (about 8000 lines of code each), tested on a large number of Prolog programs, and compared with the original implementation on an abstract domain containing modes, patterns and sharing. In conjunction with refinments of the domain algorithms, they produce an average reduction of more than 58% in computation time. Extensive experimental results on the programs are given, including computation times, hit ratios for the caches, the number of operations performed, and the time distribution. As a main result, the improved algorithms exhibit the same efficiency as the specific tools of [26, 8], despite the fact that our abstract domain is more sophisticated and accurate. the abstract operations also take 90% of the computation time indicating that the room left for improvement is very limited. Results on a simpler domain are also given and show that even extremely basic domains can benefit from the optimizations. the general-purpose character of the optimizations is also discussed. © Springer-Verlag Berlin Heidelberg 1992.

关键词： Model checking

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