空间工程辅助设计GIS系统的研究与实践

探讨GIS技术在空间工程辅助设计(例如电力、电信管线工程)方面的应用.在系统分析空间工程设计的 逻辑过程和工程辅助设计系统的发展与需求的基础上,对GIS技术在空间工程辅助设计中应用的优势及工程辅助 设计GIS系统的结构、功能和特点以及系统基本设计思路进行了探讨，指出GIS技术的引入一方面提高了空间工 程辅助设计的效率和水平，同时使空间工程辅助设计成为同时具有规划和设计功能的系统。     

地面驱动单螺杆泵杆柱的组合设计

根据地面驱动单螺杆泵的工作特点，分析了传递动力的抽油杯柱受力状况，认为抽油杆柱受复合载荷的作用，在承受扭矩的同时承受较大的轴向力，给出了各种载荷的计算方法。由第四强度理论，提出了把抽油杯柱设计成两级杆柱的等强度组合设计方法，即先按要求及标准确定两级杆柱的直径和长度，然后扶强度条件进行校核。根据油田的实际情况，编制了抽油杆柱电算程序，并给出了设计训一算实例。     

Information systems effectiveness: research designs for causal inference

Abstract. This paper examines the capacity of the research designs of 37 empirical studies of information systems (IS) effectiveness to provide a basis for the development of theories about behaviour related to IS effectiveness. The power of each study to support causal inference was evaluated in terms of (a) its handling of the time dimension, (b) its ability to weigh differences and (c) its resistance to internal validity threats that pose alternative explanations for its reported findings. Of the reviewed studies, 29.7% could account for the time dimension, 32.4% employed a comparison group and 16.2% were not susceptible to any internal validity threats. Only 13.5% of the studies combined an accounting for the time dimension with the use of a comparison group. Of these, however, only 5.4% were also invulnerable to internal validity threats. The research designs of nearly 95% of these published studies were deficient in supporting causal inference. In those studies, suggestions that one variable was causally related to another variable could not be substantiated. Encouragement for the future capacity of IS effectiveness research to support causal inference was found in a trend towards the use of quasiexperimental designs. Recommendations are made regarding ways to increase the inferential capacity of research designs employed in the study of IS effectiveness.     

基于神经网络的降雨径流预报

本文将人工神经网络应用于二滩水电站以上支流鱼河的降雨径流预报，通过建模、计算、比较和分析可知，其非线性映射能力、自学习能力和灵活性，均能较好地反映降雨径流之间的非线性的、复杂的转换关系，结合流域水文特性并合理处理建模数据，值得进一步深入研究。     

A computational framework for representing authors'' courseware models*

Abstract This paper looks at some of the problems of existing courseware authoring systems, and advocates the use of knowledge-based techniques to resolve these problems and to form the basis of future authoring environments. The prototype knowledge-based representation language, GTE, is presented as an example of a knowledge-based language which might form the basis of such environments. The final part of the paper discusses some of the developments in GTE which must take place if it is to be used within a full and flexible authoring environment. The paper will focus particularly on the question of instructional strategies, but many of the observations can be taken as relevant to all the knowledge involved in a teaching interaction.     

Macroscopic analysis of design processes based on a scheme for coding designers' cognitive actions

We have devised a new scheme for coding designers' cognitive actions from video/audio design protocols. Designers' actions are coded into four cognitive levels; physical, perceptual, functional and conceptual. Relations between actions belonging to different levels, such as dependencies and triggering relations, are also coded. The present scheme has two benefits. First, we found that design actions are definable in a systematic way using the vocabulary of the scheme, and thus a designer's cognitive behaviours in each of local design stages is represented as a structure composed of defined primitive actions. This is expected to lay the foundation for microscopic analyses of how particular types of actions contribute to the formation of key design ideas. Second, this scheme is suitable for macroscopic analyses of how designers cognitively interact with their own sketches. We examined, for a practising architect, the ways in which drawing, inspection of drawings, perception, and functional thoughts correlated with one another in his design process. The findings suggest that design sketches serve not only as external memory or as a provider of visual cues for association of non-visual information, but also as a physical setting in which design thoughts are constructed on the fly.     

SMS——智能网的业务管理系统

本文叙述了智能网的业务管理系统所实现的３种功能：业务管理功能，网络管理功能和业务管理访问功能，还介绍了业务管理和网络管理之间的关系，ＳＭＳ的集中式和分布式两种体系结构及业务管理功能的设计方法和进一步研究方向。     

Effective lightning protection schemes for distribution line

The causes of lightning outage are subdivided into direct lightning strokes and induced lightning strokes, which are identified by the characteristics of the lightning overvoltage. In the past, lightning protection devices were directed mainly toward the latter, and attention has been focused on the installation of lightning protection devices, ground wires, and reinforcement of insulators. However, lightning outages continue to occur. Thus it is extremely important to clarify the fault characteristics of lightning surges and to study the effectiveness of various lightning protection devices by considering both direct lightning stroke and induced lightning stroke in order to prevent lightning outage in the future. In this research, the electromagnetic transients program (EMTP) has been applied to the direct lightning stroke, and the induced lightning outage analysis program for multiple conductor systems has been applied to the induced lightning stroke to study the effectiveness of lightning protection devices provided by combination of various lightning protection devices. The most effective lightning protection schemes are analyzed and evaluated based on verification tests on the full scale models as well as economic considerations.     

Thermal design method of bayonet-tube evaporators and condensers

The paper describes an effectiveness-NTU design method of bayonet-tube evaporators and condensers. Including the effect of the wall superheat on the shell-side film coefficient, and using an energy balance on the tube, differential equations for the steady-state fluid temperatures are formulated. Because of the nonlinear nature of the governing equations, the fourth-order Runge-Kutta method is employed to the solution of the finite difference equations. The results are iterated with the combination of integration techniques. An upper bound to the numerical error being ±5% the fluid temperature distribution as well as the exchanger effectiveness are determined, and presented as a function of the Hurd number, the number of heat transfer units and the flow arrangement. For flow entering through the inner tube, the temperature distribution displays the occurrence of a minimum at a point other than the tube-tip of the exchanger. In an extension of the analysis, an effort is made to illustrate the deviation of the results obtained by uniform film coefficient from the present study, and the differences are outlined.