船舶电缆虚拟敷设仿真平台的研究与实现

针对船舶电装生产设计中电缆敷设设计复杂繁琐,效率低下的问题,结合实际电缆敷设设计的流程,开发了基于AutoCAD二次开发的船舶电缆虚拟敷设仿真平台。重点对虚拟敷设通道数学模型的建立、交互式图形敷设方式的设计、带限制条件的最短路径算法的实现和电缆通道的仿真进行了详细阐述。电缆虚拟敷设平台的开发已经完成,初步实现了船舶电缆的虚拟敷设。该平台为电装设计人员提供了一种直观,动态的敷设设计方式,简化了电缆敷设设计过程,提高了敷设设计的效率和质量,同时节省了电缆用量。     

AVR单片机并口ISP下载线的工作原理及其程序设计

通常ISP下载线的硬件电路和软件设计都比较复杂,不易掌握。介绍一种硬件电路和软件设计都很简单的AVR单片机下载程序设计。下载线为并口ISP下载线。分析了PC机并口相关电路和ISP下载线电路的工作原理,介绍了AVR单片机的串行编程指令及其算法。最后,以AVR单片机的ATtinyl3芯片为例给出了C语言编写的ISP下载程序。     

基于电力载波的路灯电缆防盗报警器设计

介绍了一种基于电力载波技术和模数转换器TLC3548的路灯电缆防盗报警器的硬件和软件设计实现方案。阐述了该方案的原理,即在主机与从机间进行电力载波通信以检测电缆状况,通过单片机控制TLC3548进行数据采集与分析,比较精确地测量出断缆处距路灯现场控制柜的距离,并将信息经GPRS通信模块上报给服务器。经实验证明,该防盗报警器可靠实用,性价比较高。     

Interactive analysis and design of steel frames using the AISC specification

A number of computer programs are available for the analysis of frames and for the design, according to certain codes, of the individual members of such frames. This paper describes the integration of a plane frame analysis program and the American Institute of Steel Construction (AISC) column design program with interactive computer graphics to provide a complete system for the interactive analysis and design of steel building frames.The user of the program has the option of allowing computer controlled interation between analysis and design to produce a fully stressed design or he may select complete man-machine interaction for control of the analysis-design process. The use of interactive computer graphics displays aids the engineer in interpreting the large bulk of data needed for input and produced by the analysis and design algorithms.     

Guyed tower optimization

A unique procedure for the optimum design of a guyed tower structure is presented. The method depends on a carefully established design hierarchy which is based on the observed independence of the design variables in certain portions of the design space. Powell Search and Branch-and-Bound sub-optimization routines are used to generate locally optimum designs in terms of cable area, initial cable tension, mast area and anchor to tie locations. A design example is presented and computer program capabilities are discussed.     

数字网络交互式机顶盒的双模块设计

随着数字电视的发展，市场上急需一种具有交互功能的机顶盒，但由于目前三网合一的标准尚未确定，网络数据和数字电视的压缩数据流还不能在同一条线路中传输，为解决此问题，该文给出了一个双模块设计的网络交互式机顶盒，详细阐述了其硬件和软件设计方案。     

The impact of animation interactivity on novices’ learning of introductory statistics

This study examined the impact of animation interactivity on novices’ learning of introductory statistics. The interactive animation program used in this study was created with Adobe Flash following Mayer’s multimedia design principles as well as Kristof and Satran’s interactivity theory. This study was guided by three main questions: 1) Is there any difference in achievement improvement among students who use different interactive levels of an animation program? 2) Is there any difference in confidence improvement among students who use different interactive levels of an animation program? 3) Is there any difference in program perception among students who use different interactive levels of an animation program?     

Physically based real-time interactive assembly simulation of cable harness

In this paper, we designed and developed an interactive assembly simulation system of cable harness. First, we establish a real-time physical model of cable harness based on an extension of the mass–spring model. We use various kinds of springs to describe the different properties of the cable harness: linear springs for stretching, bending springs for bending, and torsion springs for geometrical torsion and material twisting. The constraints of connectors and clips on cable harness are both considered. We also associate the elastic coefficients of various springs with the material parameters of the cable. Moreover, we use spherical bounding volume hierarchy and triangular facets for collision detection of cable harness during the assembly simulation. By applying contact forces to both ends of the cable links that collide with the surrounding environment, we obtain the real-time contact response of cable harness. Finally, we apply the proposed model to a cable assembly task. The results show that the proposed model successfully expressed the deformation of the cable harness and the interactive manipulation is computationally efficient.     

Interactive computer methods for design optimization

Two interactive methods for design optimization are discussed in this paper. The first method is implemented by the computer program GDOPT and is an essentially manual search procedure based on graphical searches of the design space within user-defined planes. In contrast, the computer program ADOPT consists of the more effective nonlinear programming techniques available and the search is mostly under computer control. The user observes progress on a graphical display and is able to modify the search procedure as desired. These two interactive methods make an extensive use of computer graphics to display search results in the form of graphs, contour plots, sensitivity curves, and search trajectories. The designer interacts with the programs through these displays and is an active participant in the decision making process. It is believed that this integrated approach to design optimization can result in an enhanced understanding of the design problem and an effective convergence to the optimum design. An example is presented which illustrates the effectiveness of this interactive technique.     

自动摊铺机测控系统软件设计

文章针对LTU125A沥青混凝土自动摊铺机开发项目的要求,分析了摊铺机测控系统的软件需求及功能,描述了测控软件的模块化结构,讨论了信号输入／输出接口程序设计、测控机与交互机及方向机之间的通信程序设计、测控主模块程序及人机交互程序设计等。     

An interactive graphics program for teaching computer aided design of beams

A computer program developed for teaching flexural design of shafts to students taking machine design courses is described. The program utilizes conversational mode interaction via a storage tube graphics terminal and it includes interactive facilities for problem definition, analysis, evaluation and modification. Some experience in using this program is also presented.     

服装用模块化计算机系统设计

针对计算机与服装一体化集成设计中系统结构和功能融合方面的问题,研究服装用模块化计算机系统的设计与实现。将服装用穿戴计算机系统的问题归纳为可靠性、集成性、人机交互性能等三个方面,为实现该系统,提出了模块化的计算机结构和三层的服装结构,通过高密度布线实现计算机模块的微小型化,基于织物编织技术的织物线缆设计实现了模块间的柔性互联。     

Computational experience with adaptive model-reference identification schemes

This paper deals with the design implementation of adaptive identification schemes using a model-reference approach. An on-line, general-purpose simulation program is developed to operate in an interactive mode. The simulation program provides the user with multiple design options and aids in the assessment of the adaptive identification process. An illustrative example is presented to demonstrate the potential features of the program.     

Interactive graphical program portability

In the opinion of the authors, a fully portable interactive graphical program should be able to take advantage of the object display terminal's hardware features where these are beneficial to the efficiency of man-machine interaction. By analysing the FORTRAN code of an interactive graphical program designed to operate on both refresh displays and storage tubes, a program design approach has evolved which attempts to reduce the effort required to achieve this aim.     

The analysis of nonlinear cable net systems and their supporting structures

The analysis of large cable net systems is feasible only with the aid of high speed digital computers. However, even computerized design of cable nets requires careful formulation and the selection of efficient solution techniques. This paper describes the solution of a general integrated structural system which includes three-dimensional beam members and cable elements that is useful to the design engineer. This solution is used to analyze an example prestressed cable structure, and results are presented to demonstrate the efficiency and accuracy of different solution techniques and to illustrate the effect of variation of important parameters.NET 3 is the general solution program. Input includes: (1) cable sizes, weights, and stress-strain characteristics; (2) initial coordinate points and cable forces due to prestressing; (3) support conditions for the cable net; (4) applied loads; and (5) data for supporting structure. The initial shape and cable forces are computed with the aid of an auxilliary program, SHAPE, given the coordinates of the cable end points, the initial prestressing forces, and an initial interior coordinate. The cable stress-strain characteristics may be linear or nonlinear. The supporting structure may be replaced with equivalent spring stiffnesses or actual three-dimensional elements.The assumptions used in the solution are: (1) cable elements are straight between nodal points and have no flexural stiffnesses; (2) the roofing and decking provide no stiffness; (3) all loads are applied at the nodal points; and (4) all supporting structural elements are elastic. It should be noted that no displacements of the cable nodal points are neglected. Even at boundaries, the elastic stiffness can be considered. Temperature changes can be analyzed to determine their effect upon the structure.Cable net structures usually have many elements and require relatively large amounts of computer time. In addition many loading and geometric conditions must be considered. To be useful as a practical design tool, it was essential that the program be as efficient as possible and require a minimum of storage. The solution utilizes a variation of the Newton-Raphson method. Initially the tangent-modulus stiffness is used. At each iteration the change in the element force is compared with the change in element force for the previous iteration to determine if the convergence rate is within a prescribed value. If it is acceptable, the stiffness for the previous iteration is used; if unacceptable for any element, tangent stiffnesses for all elements are recalculated. This technique attempts to combine the best features of the Newton-Raphson and the modified Newton-Raphson methods by increasing convergence probability and decreasing solution time.To minimize storage requirements, NET 3 has the capability of utilizing tapes in the problem solution. The storage requirements are determined internally before the solution is initiated. If the required storage exceeds that alloted for the system of equations, the solution is effected through the use of tapes.Output for the cables includes nodal point displacements, nodal point forces, and element forces; for beam elements, forces and moments are given. The solution has been verified by comparison with results by other investigators.An elliptical shaped structure, 220 by 240 ft, has been analyzed with the program to investigate the influence of several parameters. The short direction cables were prestressed, and a uniform load of 40 psf was assumed. The variables investigated include: (1) initial prestress force; (2) degree of stiffness of supporting structure; (3) cable sizes; (4) sag-span ratio; and (5) temperature change.     

VB与三菱FX系列PLC在SC-09下的通信

文介绍了三菱FX系列PLC在SC-09下的通信协议与指令,并利用VB6.0的MSComm控件进行串行通信程序的设计。该通信程序能读写FX全系列PLC内部各种软设备,强制复位与置位位映象元件。     

SPEED - an early design tool for building services

An interactive program SPEED has been produced to assist in the sketch-plan stage of building design. It will allow an architect and building services engineer to examine the interaction between the building envelope and the internal thermal and visual environment. The program is simple to use and follows a design philosophy which will be familiar to users. The amount of data that must be provided by the user is small and use is made of data files within the program. The program is fast in execution, permitting many different design solutions to be appraised at low cost.     

The design of an interactive program development system for Pascal

A program language can be defined as the language in which computer programs are written, and a programming language as the language used by the programmer to create programs. This paper presents the design of an interactive program development system which uses Pascal as both program and programming language. Principal properties of the system are a complete immediate syntax check, a program-structure oriented editor, incremental compiling techniques, and interactive interpretation and debugging of programs. The syntax check is split into three phases, and the user can change the degree of check wanted. After a change of the program only part of it is recompiled, and only necessary phases of the compiling process are performed.     

PEP: An interactive programming system with an Algol-like programming language

PEP (Program Editor and Processor) is an interactive programming system based on an Algol-like language. It is intended to replace BASIC as a system for interactive program development on small computers (LSI-11). The language processed by the system allows declaration of variables, constants and procedures; it has structured statements for conditional and repetitive execution of program parts. We describe design and implementation of the system and give our impressions after 1 year of experience with the system.     

RTI网络监控研究

分析了高层体系结构（HLA）的核心部件联邦运行支持环境,即RTI网络的监控机制在大规模虚拟试验中的重要性和监控程序的设计流程。对监控程序进行了模块化分并分析了各个模块的功能和实现方法。提出了一种利用HLA管理对象模型（MOM）中的预定义的对象类和交互类,以联邦成员的方式加入联邦,通过订购发表MOM对象类和交互类,并向RTI发送MOM交互类来实现对联邦和联邦成员进行监控的方法。