A COMPUTER METHOD FOR COMPARISON BETWEEN EHVAC AND EHVDC TRANSMISSIONS

A computer method for comprehensive comparison between EHVAC and EHVDC is presented in this paper after analyzing the fundamental characteristics and studying the design methods of these two types of transmi-sson schemes. Some formulas are developed and an appropriate mathematical model is established. A generally applicable computer program is exploited which is acceptable to IBM-pc and its compatible micro-computers. The results of numerical practical project of the program are given to prove the correctness of the model and the program described in this paper,and it also shows that the method proposed is an efficient one with the practical values in power system planning.     

THE DEVELOPMENT OF COMPUTER AIDED NORM OF WORKING HOUR PLANNING SYSTEM

Based on Group Technology, part families of the norm of working hour are formed according to the similarity among components. With the progressive regerssion, the models of the norm of working hour are built for every part family. A computer aided norm model building program and a computer aided norm of working hour planning system are developed. The system is successfully integrated with CAD/CAPP system. Some examples of the model building and calculation results are illustrated as well.     

Module Design of Refrigerant Themodynamic Properties Calculation for Simulation of Refrigeration and Air Condition System

This paper constructs a model of refrigerant thermodynamic properties calculation for simulation of refrigeration and air condition system based on the parametric equations of state of refrigerant. The Visual C++ 6.0 language is used to develop this model, which has a friendly user interface (UI). This program is easy to learn and use and it has reliably function. Compared with the data provided by the standard graphs and tables of refrigerant thermodynamic properties, the calculation results of this model have certain precision and meet the expectative requirements.     

Optimal Load Curtailment in Bulk Power System Reliability Evaluation

This paper studies the question for considering optimal load curtailment in bulk power system adequacy evaluation. A minimization model of load curtailment is utilized for the contingency states which may have load curtailment. In order to calculate realistic bus indexes, two practical load curtailment philosophies are incorporated in the minimization model of load curtailment, which is achieved in computer program developed for bulk power system reliability evaluation. The minimization model of load curtailment, correlated algorithms, and flow chart of program are given in this paper. The effectiveness and availability of the model are verified from two case studies.     

CALCULATION OF AVERAGE SKY LIGHTING

Under the condition of average sky model,this paper studies the luminous flux arriving at the window and suggests the modified daylightingcoefficient method for estimating the area of the window.The method is simpleand easy to be carried out.And according to average sky luminance model,this paper has carried out the calculation of average sky lighting with a computer.The method described above is verified reasonable and applicable in engineering.     

Deformation of Soft Ground with Consideration of the Concomitant Damage

On the basis of continuum damage mechanics theory, the effective stress theory of damaged porous media was presented and its modified self contained seepage differential equation was deduced. The traditional Drucker Prager yield criterion subsequently was modified, and a coupled seepage and damage finite element computer program compiled that was combined with the modified Biot consolidation equation. A simple roadbed foundation model then was analyzed and calculated using the computer program we compiled, and the typical node settlement, pore pressure, and damage variables were discussed and compared with those from the analytic solution. The results show that the damage finite element program we compiled is reasonable and effective.     

棉铃虫灾变预警与辅助防治决策系统(MLCYJC-CDROM)研究

依据棉铃虫灾变预警与防治决策及系统分析原理 ,采用结构化分析与结构化设计和面向对象的设计方法 ,应用 VB编程开发而成。整个系统是一个融灾变预警与辅助防治决策信息的实况输入、数据处理、作用评估及结果输出于一体的实用性较强的计算机应用系统。其中灾变预警亚系统由灾变预警指标体系与灾变警级评估警报体系组成。辅助防治决策亚系统既接受灾变预警亚系统的信息传输 ,也含有辅助防治决策相关信息。据此确定棉铃虫灾变预警警级的等级 ,并指导综合防治决策 ,可使灾变警级预警更加符合实际 ,指导减灾防治更有科学依据     

A four-compartment computer virus propagation model with graded infection rate

A new resident virus propagation model with graded infection rate is established based on the properties of two important stages undergoing by resident virus, which are the latent phase, in which resident virus cannot infect other hosts because it has not yet been loaded into memory and the active phase, in which resident virus resides in memory and infects any suitable program that is executed on the computer. Two computer compartments with different infection rate are established. Furthermore, the dynamic behaviors of this model are investigated by stability theory and numerical simulations. It is found that the dynamical properties of this model are determined by basic reproductive rate. Specifically, virus-free equilibrium is globally asymptotically stable if basic reproductive rate is less than or equal to one , whereas the local asymptotical stability of the viral equilibrium is guaranteed if basic reproductive rate is bigger than one, followed by a conjecture on its global stability. Then the sensitivity analysis of basic reproductive rate to the system parameters is investigated and a collection of policies is advised to control the spread of computer virus over the Internet.     

OPTIMAL SBLECTION OF CONSTRUCTION SCHEME OF THE MAIN BUILDING IN HIGY-RISE REINFORCED CONCRETE SHEAR-WALL STRUCTURE

Relying on the mathematical model of fuzzy comprehensive estimation of con-struction sclieme optmization,comprehensive evaluation coefficient of every scheme can be figuredout with the auther's computer program in order to get optimal solution. This paper presents themethod of doing reliability analysis to optimal solution.     

COMPUTER-AIDED ANALYSIS AND DESIGN FOR THE BASE STRUCTURE OF A MOVABLE TOWER CRANE

This paper is one of the achievements of the researchitem for computer-aided design of tower crane's steel structure.In thepaper,taking the well-base structure as an example,first the method establishing the mechanical model is explained for the base structure ofa movable tower crane.Then the math model of its optimal design andthe N-S figures for the computer program is described and calculatedusing discrete optimal technology.Finally the problems related to thedesign for the base structure of a movable tower crane are briefly illu-strated.     

Method to Determine the Intersection of Two Arbitrary Solid Polygon With Node Operation

The method to polygon' intersection is applied in computational geometry, computer graphics, GIS, evaluation of geo-hazards and civil engineering. Based on the node state of polygon, the authors propose the method and algorithm of polygon' intersection, the key to which is node operation. This method's concept is simple; and it is easy to computer program's implementation. It avoids to singular problem of Boolean Operation, and is easy to solve the problem of overlapping side and sides intersecting in node of polygon. For the arbitrary way of intersecting of arbitrary solid polygon, this method is accurate and general.     

广西芒果电脑农业专家系统的研究与应用

芒果电脑农业专家系统是基于农业专家知识和模仿农业专家进行推理决策的计算机程序系统,在Paid开发平台的基础上研究开发出面向基层农技推广人员和广大农户的芒果农业专家系统。介绍了芒果农业专家系统的系统结构体系、系统目标、系统内容及应用示范情况。为农民和基层农技人员提供各种农业问题咨询服务与决策方案,起到高层次农业专家随时都能亲临现场指导农业生产的作用。对加速芒果科技的普及和科技成果转化,实现广西芒果向产业化发展具有重大意义。     

生鲜农产品冷链物流车辆配送路径优化研究

针对生鲜农产品易变质、易腐蚀的特性,探索冷链物流配送路径的优化方法。首先通过对固定成本、运输成本、货损成本、惩罚成本和能耗成本的研究,建立了以总成本最小为目标函数的农产品冷链物流车辆配送路径优化模型,然后采用改进的蚁群算法对模型进行设计,最后通过实例分析,运用MATLAB软件编写算法程序,求解结果验证了设计的模型的合理性和可行性。     

A Time-effect Model for Concrete Compressive Strength under Sustained Load

Based on the existed stress-strain curve of concrete prism under one-off short-term load and the concrete creep model, a new time-effect model for evaluation of concrete compressive strength is established through the synthesis of the concrete creep attenuating effect under sustained load and the concrete strength enhancing effect by age, a corresponding computer program has been developed. The computation of related indices and their change rules of several different-grade concrete materials with the program was carried out and the results were compared with experimental data and finite element numerical results reported in the literature, the reasonableness and practicality of the proposed new model have been verified.     

计算机视觉技术在水稻氮素营养诊断中应用的研究进展

为探究水稻冠层外观特征与水稻氮素营养状况的关系,综述了应用计算机视觉技术进行水稻氮素营养诊断的基本思路及研究进展。主要分述了常规性水稻氮素营养指标的获取,水稻冠层图像的获取、预处理以及特征的提取与优化,水稻氮素营养诊断模型建立的方法等方面的内容。指出近地面水稻冠层图像的获取方法、水稻图像处理方法、多种综合性特征的优化选择方式都有待进一步研究,应用机器学习进行水稻氮素营养诊断建模的方法需要更加深入探究。今后应加大计算机视觉技术在水稻氮素营养诊断相关研究中的应用,将多种图像处理方法、特征优化选择方法与机器学习建模方法相结合,并探寻更为简便易行的方法进行水稻氮素营养诊断。     

二维高炉区域BFC网格生成技术及其Matlab实现

利用数学模型对高炉冶炼过程进行模拟是高炉炼铁新工艺研发的有效方法,网格生成技术是数值模拟过程中重要的前处理过程,是高炉模拟计算的先决条件。生成网格的质量对高炉模型模拟的精度、效率以及收敛性具有重要影响,因此,建立优质的网格对高炉数学模型的求解具有重要意义。文中提出了一种适用于高炉数学模型的适体坐标系(BFC)网格的生成方法,从求解区域的划分、椭圆型方程的转换、椭圆型方程的离散及BFC网格生成步骤等方面进行了研究,并把死料区的边界作为BFC网格计算的边界条件,使数学模型的求解过程得以简化。采用带有源项的泊松方程作为变换方程,网格的正交性和疏密程度便于控制。该网格生成算法原理简单、易于编程、网格生成效率高,生成的网格能够满足数学模型求解的要求。     

THE OVERALL LOAD-BEARING CAPACITY AND EFFECTIVE LENGTHS OF STEPPED COLUMNS OF PINNED R.C.PORTAL FRAMES WITH FIXED BASES

In this paper,a computer program for nonlinear analysis ofa special frame is developed.The frame has all columns fixed at the base and hinged at the top.By taking the frame as a whole,the behavior ofthe frame is studied from the test results of three specimens of the frame andlarge amount of results of computer program.The minimun value of total sumof vertical loads sustained by the frame is found and a new method of deter-mining the effective length of stepped columns is suggested.     

Tool path planning and geometry simulation for multi axis CNC belt grinding

Belt grinding machine with multi axis computer number control(CNC) system can effectively process parts with complex moulding surfaces.In this paper,iso parametric and iso planar tool path planning strategies customized for this kind of machine are proposed.The tool path generation methods are designed based on the analysis of the belt grinding process.By using least square method,optimized cross section normal is computed in the iso planar method.To improve the design efficiency of path planning,reduce experiments and increase economical benefit,the geometric simulation program based on linear grinding model is developed.Experiment on a turbine blade profile shows that the proposed algorithms work satisfyingly.     

蠕变模型对约束钢梁抗火性能分析的影响

钢材在高温和荷载作用下产生明显蠕变变形,影响火灾中结构的变形和受力性能。现有的蠕变模型较多,但没有一个广泛适用的蠕变模型。不同的蠕变模型对钢结构抗火分析结果有很大影响。为了量化蠕变模型对约束钢梁抗火性能分析的影响,对5种常用的蠕变模型进行了对比分析。采用编写的约束钢梁计算程序,分别计算5种蠕变模型下约束钢梁的抗火性能并与试验数据进行对比。结果表明,采用Norton蠕变模型的计算结果与试验数据吻合最好。最后对影响约束钢梁抗火性能参数进行了研究,研究发现,Harmathy蠕变模型对约束梁抗火性能分析结果影响最大;不同蠕变模型对不同荷载比、约束刚度下的约束钢梁抗火性能影响程度均不同。     

Voting Model Design for Group Decisionn Support System

In the group decision supporting system, no matter how excellent the individual decision terminal is, it's difficult to ensure the correction of the final decision without a efficient and reliable GDSS coordinated system.Since the voting instrument is the key part of the GDSS, the efficiency and the reliability of the system are very important and must be programmed specially. Under the common situation, the voting instrument is produced by the pure software method. However, the pure software method is liable to be attacked and destroyed by the computer virus and hacker program in the circumstance of the network group decision system. While, the voting model based on the hardware logic method takes the advantage of the speed and reliability over the software model.