摘要:

AbstractA lot of current e‐mail systems are ASCII text‐based, e.g. the e‐mail system in Internet. In the coming era of multimedia, e‐mails will be composed of other non‐text‐based information. This paper presents an evolution approach to enhance the capabilities of the current text‐based e‐mail systems. Using the proposed approach, an adapter is added to the top of the current system. As a result, multimedia e‐mails can be transmitted without changing the kernel part of the existing systems. We also propose an encoding scheme that has a 7/8 bandwidth utilization rate. Using this encoding scheme, all of the non‐ASCII data formats, e.g. image, voice, graphics, and so on, will be transformed to the ASCII data formats. Recently, we have developed an experimental multimedia e‐mail system using the proposed method. Our system has been developed on SUN SPARC workstations and an X‐window‐based user‐interfac

ISSN:0038-0644    

DOI:10.1002/spe.4380240902

出版商:John Wiley&Sons, Ltd.    

年代:1994

数据来源: WILEY

摘要:

AbstractThe searching power of massively parallel associative computers is an under used and under investigated capability that can be used to facilitate software development. This paper describes the development of a context sensitive compiler for pattern‐matching languages using that searching power. The described compiler was implemented on the STARAN parallel computer and the compiled OPS5 programs were also executed on the STARAN obtaining an estimated throughput of 6000 rules per second. The described compilation of production rules into equivalent procedural rules is completely data parallel, with the degree of parallelism depending on the number of tokens in the program being compiled. During any one step of the context‐sensitive analysis, the entire program is processed in constant t

ISSN:0038-0644    

DOI:10.1002/spe.4380240903

出版商:John Wiley&Sons, Ltd.    

年代:1994

数据来源: WILEY

摘要:

AbstractThe problem of finding shortest paths arises in many contexts; testing restoration algorithms and developing design packages for large telecommunications networks are two cases where the simple task of finding sets of restoration paths can consume up to 95 per cent of the execution time of an application program. This paper presents experimental studies of several well‐known shortest‐paths algorithms adapted to the task of finding the k‐successively‐shortest link‐disjoint replacement paths for restoration in a telecommunications network with n nodes. The implementations range in complexity fromO(kn2) when based on Dijkstra's original method, through several improvements to an efficient implementation ofO(kn[v+longn]) complexity, and finally to anO(kn) implementation for the special case of edge‐sparse graphs with small integer edge weights. Here v is the maximum degree of a node in the network. Several alternatives were tested during the course of these studies, particularly with a view to minimizing the number of heap updates, These alternatives are possible because we are searching for several paths between a given pair of nodes, rather than just one path between one or more pairs of nodes. Two fairly straightforward changes yield a decrease in execution time, whereas a more complex heap management strategy consumes as much time in the added code as it releases from the main routine. Experimental results confirm the theoretical complexity of q k n log n) and demonstrate a speed‐up of nearly an order of magnitude over the simplerO(kn2) implementation in the largest networks tested. The optimized implementation is recommended for planning and operational applications of k‐shortest paths rerouting for telecommunications network restoration and restorable network design. If hop counts or small integer link weights can be used to measure distances, then the qkn) implementation is recommended, as typical telecommunications networks

ISSN:0038-0644    

DOI:10.1002/spe.4380240904

出版商:John Wiley&Sons, Ltd.    

年代:1994

数据来源: WILEY

摘要:

AbstractIt is possible, by appropriate programming language extensions, to use the assignment statement as the sole means of changing the value of a variable, thereby eliminating the need to modify routine arguments by output parameters. Several suggestions are made to enhance the syntax and semantics of routine definition and assignment to maintain notational convenience and efficient execution normally associated with output parameters. Finally, an almost complete implementation of the ideas is presented in C.

ISSN:0038-0644    

DOI:10.1002/spe.4380240905

出版商:John Wiley&Sons, Ltd.    

年代:1994

数据来源: WILEY

ISSN:0038-0644    

DOI:10.1002/spe.4380240901

出版商:John Wiley&Sons, Ltd.    

年代:1994

数据来源: WILEY