TSA—OT：一个调度Out—Tree任务科的算法

对于把一个任务群调度到多个处理器的问题,人们往往只注重找到一个调度路径最短的算法,却忽略了要节省处理器。收于Out-Tree任务图代表分治算法的一大类问题,因此,文中专门针对该任务图,给出了一个基于任务复制的算法TSA－OT。它首先分配关键路径上的任务结点,然后在不改变调度长度的情况下,把非关键路径上的结点尽可能分配到已用的处理器上。并且,该算法将Out-Tree任务图中的所有通信都化为零。TSA－OT算法与近几年所提出的TDS,CPFD,DCP算法之间的比较表明,TSA－OT算法不仅调度长度最短,而且采用了更少或相当个数的处理器。     

An Appreciation

Five male subjects were trained to work in non-erect task postures and then shovelled in five task postures: normal erect, under ceilings set at 80 and 60% of normal stature; kneeling without ceiling restraint; and, kneeling under a ceiling set at 80% of kneeling height. The steady-state data for all five task postures were averaged with a resulting heart rate of 131 beats min^?1 and an oxygen uptake of 1·41^?1 These averaged values compared very well with studies of actual coal miners shovelling in normal working environments     

电子商务系统安全与电子签名技术改进

阐述了电子商务系统的安全性需求以及作为安全保障中必不可缺的电子签名关键技术的实现过程,指出现行电子签名实现过程中存在的不足,提出了基于“安全/速度比”的数字签名强度理论及其改进实现方案,并指出了电子商务安全技术的发展方向。     

An improved maxnet

In the proposed model, dynamic inhibitory weights are used to speed up the convergence rate, and a new convergence rule is applied to find all maxima. The hardware implementation of the proposed model is presented in the study, and simulation results indicate that the proposed model converges much faster than the other networks.     

An Intrusion-Detection Model

A model of a real-time intrusion-detection expert system capable of detecting break-ins, penetrations, and other forms of computer abuse is described. The model is based on the hypothesis that security violations can be detected by monitoring a system's audit records for abnormal patterns of system usage. The model includes profiles for representing the behavior of subjects with respect to objects in terms of metrics and statistical models, and rules for acquiring knowledge about this behavior from audit records and for detecting anomalous behavior. The model is independent of any particular system, application environment, system vulnerability, or type of intrusion, thereby providing a framework for a general-purpose intrusion-detection expert system.     

An unrealistic parser

A parser for natural language is proposed which, (a) concentrates on methodological procedures rather than grammatical details of a natural language; (b) is based on the claim that in order to exploit the full power of computers, models of human language processing should not necessarily be designed to simulate human behavior; and (c) is designed for the advanced technology of the computers of the future. the parser is a component of a language understanding machine which is only represented in a sketch in this article.     

An IKBS implementation

This paper details the practical approaches and solutions taken in the implementation of an INTERLISP programmed knowledge based program. Although some of the solutions used are particular to the specific problem domain of this program, the general pragmatic methods are of wider interest. The program excerpts are given in Pseudo-LISP code.     

An Information Avalanche

The Internet has added yet another dimension to the production and consumption of information. Long merely consumers of content, Internauts are now also major producers of it. Search engines make it possible to sift through the enormous quantity of material that is finding its way into digital form. Going online has become an adventure in discovery for those who eagerly surf the billions of Web pages housed in the global Internet. Because of its global reach, the Internet seriously threatens to undermine IP protection regimes that have long served copyright holders     

一个邮件监听程序

介绍了如何利用VＢ６．０的Ｗinsock控件通过ＰＯＰ３协议来实现对Ｅ－mail的实时监听,并提出了作为实用软件需进一步完善的方面。     

An NSF Proposal

The objectives of this research are to improve software productivity, reliability, and performance of complex systems. The approach combines program transformations, sometimes in reflective ways, to turn very high level perspicuous specifications into efficient implementations. These transformations will be implemented in a meta-transformational system, which itself will be transformed from an executable specification into efficient code. Experiments will be conducted to assess the research objectives in scaled up applications targetted to systems that perform complex program analysis and translation.The transformations to be used include dominated convergence (for implementing fixed points efficiently), finite differencing (for replacing costly repeated calculations by less expensive incremental counterparts), data structure selection (for simulating associative access on a RAM in real time), and partial evaluation (for eliminating interpretive overhead and simplification). Correctness of these transformations, of user-defined transformations, and of the transformational system itself will be addressed in part. Both the partial evaluator and components of the transformational system that perform inference and conditional rewriting will be derived by transformation from high level specifications. Other transformations will be specified in terms of Datalog-like inference and conditional rewriting rules that should be amenable to various forms of rule induction.Previously, Cai and Paige in [12] used an ideal model of productivity free from all human factors in order to demonstrate experimentally how a transformation from a low level specification language into C could be used to obtain a five-fold increase in the productivity of efficient algorithm implementation in C in comparison to hand-coded C. However, only small-scale examples were considered. The proposed research includes a plan to expand this model of productivity to involve other specification languages (and their transformation to C), and to conduct experiments to demonstrate how to obtain a similar five-fold improvement in productivity for large-scale examples of C programs that might exceed 100,000 lines.The proposal lays out extensive evidence to support the approach, which will be evaluated together with its theoretical underpinnings through substantial experiments. If successful, the results are expected to have important scientific and economic impact. They are also expected to make interesting, new pedagogical connections between the areas of programming languages, software engineering, databases, artificial intelligence, and algorithms.     

An EDA compendium

Reviewed in this issue The Electronic Design Automation Handbook, by Dirk Jansen (Kluwer Academic Publishers,2003, ISBN 1-402-07502-2, 244 pp., $148).     

An Electronic Secretary

This paper describes an electronic mail system which has been implemented to provide facilities for the receiver as well as the sender of electronic mail. As well as the usual mail creation, transmission and filing operations, the system allows the receiver to specify automatic redirection of mail, and provides classification facilities so that the order of mail presentation is under the receiver's control. The system also includes an automatic mechanism for acknowledging mail and for cancelling mail which is either out-of-date or which was sent in error. The model on which the system is based is a non-automated office, so analogues of waste paper baskets, etc. are provided.