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Functional programming for concurrent and distributed computing
R&D reports 'R&D reports' is a snapshot of the "state of the art' in computing design, software development and engineering applications seen through items selected from international scientific publications and the trade press. Applications Chan, Y T, Ching, P C, and Lai, W M 'A microcomputer-based, speakerindependent isolated word recognition system' MicrocompuL AppL Vol 6 No 1 (1987) pp 25-28 Presents a word recognition scheme, realizable on a microcomputer, that avoids time warping. The scheme is designed for the recognition of the Southern China dialect, Cantonese.
Randall, l 'Digital potentiometer brings pPbased control to audio systems' EDN Vol 32 No 20 (1 October 1987) pp 177-186 Most audio applications still use mechanical potentiometer volume and tone controls. Digitally controlled, microprocessor-based potentiometers, however, offer programmability and greater reliability and are finding increasing use, says Randall.
Saito, K, Kamiyama, K, Sukegawa, T, Matsui, T and Okuyama, T 'A multimicroprocessor-based fully digital AC drive system for rolling mills' IEEETrans. Industry AppL Vol IA23 No 3 (May/June 1987) pp 538544 Theoretical considerations to control voltage disturbances in cycloconverter-fed AC drives have been verified using factory test data obtained with a multimicroprocessorbased 72-arm cycloconverter-fed 5000kW induction motor drive control system. Cache memory Smith, A l 'Line (block) size choice for CPU cache memories' IEEETrans. CompuL Vol C-36 No 9 (September 1987) pp 1063-1075 Vol 11 No 10 December 1987
Line (block) size is the cache parameter, along with overall cache size, that most strongly affects cache performance. Excessively large or small lines can increase the 'miss' ratio; large lines can also create high levels of memory traffic in multiprocessor systems. Factors that affect particularly the cache miss ratio are studied through the use of tracedriven simulation, using 27 traces from five different machine architectures. For high-performance microprocessor designs, it is found that line sizes in the range from 16 to 64 byte appear to be best.
Distributed software
Special issue Software Eng. J. Vol 2 No 5 (September 1987)
Bastable, A, Ireland, D M and Langsford, A 'Building an open communication application' pp 178-183 Halsall, F and Hui, S C 'Performance monitoring and evaluation of large embedded systems' pp 184-192 Shrivastava, S K, Dixon, G N and Parrington, G D 'Objects and actions in reliable distributed systems' pp 160-168 Walpole, J, Blair, G S, Hutchinson, D and Nicol, J R 'Transaction mechanisms for distributed programming environments' pp 169-177 Wilbur, S and Bacarisse, B 'Building distributed systems with remote procedure call' pp 148-159 Five papers present UK work on solving the problems in designing, building and debugging distributed systems software.
Burton, F W 'Functional programming for concurrent and distributed computing' CompuL J. Vol 30 No 5 (October 1987) pp 437-450 One approach to parallel computing is to use functional languages, such as
LISP, which are easy to read, write, verify and transform. The more conventional approach is to use procedural languages which give the programmer a high degree of control over the runtime behaviour of a program. Burton argues that for simplicity and efficiency the two approaches need to be reconciled. To do so, he proposes a set of annotations to control the runtime behaviour of a functional program, so that the logic of the program is largely separated from the control of its evaluation.
Gait, I 'Synchronizing multiprocessor access to shared operating system data structures' Comput. Syst. ScL Eng. Vol 2 No 4 (October 1987) pp 186-191 Describes a software method, applicable to a variety of busoriented architectures, of synchronizing multiprocessor access to shared operating system data, e.g. scheduling queues and message queues for interprocess communications.
Distributed systems Micheletti, G and Salati, C 'A low-cost distributed architecture for telecommunication systems' IEEE Micro Vol 7 No 5 (October 1987) pp 70-82 Several low-cost multipoint connections -- Starlan, Omninet, Appletalk and Bitbus -- exist for distributed control architectures. The authors describe another such architecture that supports applicationtailored protocols and provides an interface that is IEEE 802 MAC compatible.
Nichols, K M and Messerschmitt, D G 'Traffic-specific interconnection networks for multicomputers' IEEEE Trans. CompuL Vol 0 3 6 No 10 (October 1987) pp 1183-1196 General-purpose multiprocessor interconnection networks (ICNs) are being widely studied across a range of
559
Randall, l 'Digital potentiometer brings pPbased control to audio systems' EDN Vol 32 No 20 (1 October 1987) pp 177-186 Most audio applications still use mechanical potentiometer volume and tone controls. Digitally controlled, microprocessor-based potentiometers, however, offer programmability and greater reliability and are finding increasing use, says Randall.
Saito, K, Kamiyama, K, Sukegawa, T, Matsui, T and Okuyama, T 'A multimicroprocessor-based fully digital AC drive system for rolling mills' IEEETrans. Industry AppL Vol IA23 No 3 (May/June 1987) pp 538544 Theoretical considerations to control voltage disturbances in cycloconverter-fed AC drives have been verified using factory test data obtained with a multimicroprocessorbased 72-arm cycloconverter-fed 5000kW induction motor drive control system. Cache memory Smith, A l 'Line (block) size choice for CPU cache memories' IEEETrans. CompuL Vol C-36 No 9 (September 1987) pp 1063-1075 Vol 11 No 10 December 1987
Line (block) size is the cache parameter, along with overall cache size, that most strongly affects cache performance. Excessively large or small lines can increase the 'miss' ratio; large lines can also create high levels of memory traffic in multiprocessor systems. Factors that affect particularly the cache miss ratio are studied through the use of tracedriven simulation, using 27 traces from five different machine architectures. For high-performance microprocessor designs, it is found that line sizes in the range from 16 to 64 byte appear to be best.
Distributed software
Special issue Software Eng. J. Vol 2 No 5 (September 1987)
Bastable, A, Ireland, D M and Langsford, A 'Building an open communication application' pp 178-183 Halsall, F and Hui, S C 'Performance monitoring and evaluation of large embedded systems' pp 184-192 Shrivastava, S K, Dixon, G N and Parrington, G D 'Objects and actions in reliable distributed systems' pp 160-168 Walpole, J, Blair, G S, Hutchinson, D and Nicol, J R 'Transaction mechanisms for distributed programming environments' pp 169-177 Wilbur, S and Bacarisse, B 'Building distributed systems with remote procedure call' pp 148-159 Five papers present UK work on solving the problems in designing, building and debugging distributed systems software.
Burton, F W 'Functional programming for concurrent and distributed computing' CompuL J. Vol 30 No 5 (October 1987) pp 437-450 One approach to parallel computing is to use functional languages, such as
LISP, which are easy to read, write, verify and transform. The more conventional approach is to use procedural languages which give the programmer a high degree of control over the runtime behaviour of a program. Burton argues that for simplicity and efficiency the two approaches need to be reconciled. To do so, he proposes a set of annotations to control the runtime behaviour of a functional program, so that the logic of the program is largely separated from the control of its evaluation.
Gait, I 'Synchronizing multiprocessor access to shared operating system data structures' Comput. Syst. ScL Eng. Vol 2 No 4 (October 1987) pp 186-191 Describes a software method, applicable to a variety of busoriented architectures, of synchronizing multiprocessor access to shared operating system data, e.g. scheduling queues and message queues for interprocess communications.
Distributed systems Micheletti, G and Salati, C 'A low-cost distributed architecture for telecommunication systems' IEEE Micro Vol 7 No 5 (October 1987) pp 70-82 Several low-cost multipoint connections -- Starlan, Omninet, Appletalk and Bitbus -- exist for distributed control architectures. The authors describe another such architecture that supports applicationtailored protocols and provides an interface that is IEEE 802 MAC compatible.
Nichols, K M and Messerschmitt, D G 'Traffic-specific interconnection networks for multicomputers' IEEEE Trans. CompuL Vol 0 3 6 No 10 (October 1987) pp 1183-1196 General-purpose multiprocessor interconnection networks (ICNs) are being widely studied across a range of
559