NETWORK FEOW APPROACH TO RELIABILITY EVALUATION IN IARGE SCALE NETWORKS BY MIXING INCREASING ELOW WITH DECREASING FLOW

Based on the maximum flow principle about networks, a network flow approach to reliability evaluation in large scale netwerks ty mixing inereasing flow with decreasing flow is proposed in this paper.This approach gets the initial flow of each branch in a r.etwork associated with a state of the retwork by decreasing flows of some branches correlative to another state of the network.As a result, the number of flow compute required can be reduced enormously.The numerical example shows that the approach is powerful. The comparison of this approach with the minimal cutset one is also given in this paper.     

MAKING AN APPROACH TO THE SOIL CAVITY PROBLEM

This paper presents that the soil cavity is a kind of the environmental-geological problem.The formation and development of the soil cavity arein close relationship with the construction of buildings.Some problemsof the soil cavity still need to be further studied.This paper proposes someviews on its concept,forming conditions,classification,mechanism,infl-uencing formation factors and development of different types.The investiga-tion of their appearance development and distribution is of significance inengineering geology and hydrogeology.     

AUTOMATIC CONTINGENCY SELECTION AND RANKING BY NETWORK PROGRAMMING APPROACH

This paper presents a new approach ,to the automatic contingency selection and ranking by the network flow programming (NFP). A complex cost optimisation model based on economy and security, and several simplified models are proposed in the paper. The performance index is the total load curtailment or its weighted value. All the solution algorithms are OKA. The model and its algorithm is tested on IEEE 30-Bus System and the encouraging results are obtained.     

A MULTI -OBJECTIVE FUZZY DECISION -MAKING APPROACH FOR POWER NETWORK PLANNING UNDER UNCERTAINTY

This paper proposes a multi - objective fuzzy decision - making approach for power network planning under uncertainty ,which simutaneously considers not only the least investment cost,the minimum power loss,the maximum reliability,and the least environmental impacts, but also the uncertainty about the future load growth and the capital investment availability. The validity and effectiveness of the proposed approach is verified with numerical examples.     

APPLICATION OF A CONVEX NETWORK FLOW PROGRAMMING TO THE ECONOMIC POWER DISPATCH

Analyses the characteristics of convex network flow programming of the economic power dispatch with security and presents a rapid algorithm. The numerical examples are given to demonstrate the effectiveness of the algorithm.     

AN APPROACH TO SOLVING QUADRATIC PROGRAMMING AND ITS APPLICATION TO SECURE ECONOMIC DISPATCH

Based on the selaxaticn t echnique, a new approach to solving quadratic programming is presented in this paper. The idea of parametric programming is introduced in the process of solving the problem,and the optimal solution can be obtained through a finite numfer of search iterations. The features of the proposed method are few regurements for the initial values and little computation. It can also be used to solve the parametric quadratic programming. As an example of application, it is applied to solve a real power secure economic dispatch problem in electric power systems,and its calculation results are given.     

仓库通风降温网络的设计

收集整理了我国近５０种不同仓容的房式仓尺寸数据，根据通风网络的布置关系，对途径比公式推导应用和仓库水平网络的设计方法进行了较为详尽的阐述。     

A SIMPLE AND FAST DRAWING APPROACH FOR ARROW DIAGRAM

This paper discusses the drawing approach arrow diagram. After repeated explorations and thinking,a simple and fast drawing approach for arrow diagram is formulated. The approach overcomes the drawback of existing drawing methods. Besides its fastness,it has the advantages of clear presentation of logical relations,easy access to correctness and it can be easily grasped by beginners.     

世界储粮生态系统网络体系的研究设想

为了进一步促进中、加科技研究合作,在中国、加拿大近几十年粮堆生态系统研究成就的基础上,参考了我国7000-10000年以来的先民储粮技术经验,特别是近60年来我国的粮食系统科技创新进展;参考了世界一些粮食储藏技术比较发达国家取得的研究成果,系统分析了建设世界储粮生态系统网络体系的必要性,清晰地提出了网络体系的研究设想及相关研究课题。     

HATURAL CONVECTION HEAT TRANSFER JN AN ENCLOSURE WITH A LOCAL INTERNAL HEAT SOURCE

Numerical analysis is made for the unsteady and steady, two-dimensional laminar natural convection in an enclosure caused simultaneously by the external heating and a local internal heat source. The velocities and temperature profiles are given, the average and local Nusselt numbers for the hot and cold surfaces obtained, and the equivalent relative intensity of the internal heat source, the critical equivalent relative intensity of the internal heat source and the transient control regime defined. The results show that there exist five flow patterns with changing the external or internal Rayleigh number, and the heat transfer performance for each flow pattern region is different.     

A DECOMPOSED OPTIMIZATION MODEL FOR POWER NETWORK PLANNING

This paper presents a decomposed optimization model for power network planning. The planning problem is divided into master problem to determine the investment decisions and subproblems to deterimne the operation decisions. In the proposed model, the effects of multi load levels,stochastic line outages,power loss cost and load curtailment cost on the investment decisions are considered. The results of the examples prove the feasibility and effectiveness of the proposed model.     

华北平原农村储粮技术优化集成

通过对华北平原三省（河南省、河北省、山东省）的调研,针对目前农户储粮存在的普遍问题,提出农村储粮实用技术优化集成、农户储粮推荐装具和农户储粮中适用的化学药剂,这对提高我国农村储粮整体水平,提高农民的生活水平,为国家粮库提供高品质粮源,增强我国粮食的国际竞争力具有重要的意义.     

APPLICATION OF THE STUDY ON TOWN-SYSTEM LAYOUT TO MOUNTAINOUS AREA IN LESHAN REGION

According to the charactor of the tonw-system layout in moun-tainous area,this paper analyses current situations and existing problems ontown-system in Leshan region,combining with the practice of the town-system planning in this region.This paper also studies how to make the town-system in the region rational layout in the light of the economic andsocial development tendency in the end of the 20th century and the beginningof the 21st century.     

粮食储备库综合测试专家系统

专家系统在粮食储备库中的应用是一个崭新的领域,可以大大提高仓储检测、控制与管理的智能化、现代化进程,保证仓储产品的质量,提高劳动生产率,本文对粮食储备库的温度、湿度、水分等参数测试专家系统的体系结构与实现方案作了详细的介绍。     

APPLICATION OF NETWORK PROGRAM SYSTEM IN PROGRESS CONTROL OF LARGE-SCALE OR MIDDLE-SIZED CONSTRUCTION PROJECTS

This paper presents some principles and methods which work out schedules witha network program system for large-scale or middle-sized construction projects. These projects arelarge in scale,complicated in structure and long in construction time.Tese ways will control con-struction projects effectively and guarantee to bring about schedules.     

北京蔬菜病害的基本调查

1981—1985年,作者对北京蔬菜病害进行了基本调查,共收集了55种蔬菜上的402种病害.内有病原183种,其中病原真菌135种、病毒18种、细菌9种、寄生线虫14种、寄生性种子植物2种、非侵染病害5种.明确了北京蔬菜病害分布的生态类型,各类病害发生的情况,蔬菜病害加重的原因并提出了综合治理北京蔬菜病害的建议.     

A MONTE CARLO APPROACH APPLIED TO THE ERROR ESTIMATION OF STANDARDLESS QUANTITATIVE PHASE ANALYSIS

A Monte Carlo approach is appplied to the error estimation and error analysis of X-ray diffraction standardless quantitative phase analysis and the coefficient of its variation is cal dilated .which is compared with the error estimation by the condition number of the coefficient matrix of linear equations. The Monte Carlo error estimation is applied to the standardless quantitative matrix-flushing method, in which the mixture of KC1. CaCO3. ZnO and BaCO3 is analyzed as an example.     

A STUOY ON TNE POLICYMAKING MODEL OF INVEST IN THE INDUSTRIAL PROJECTS TO BE INUNDATED IN TNE RESERVIOR AREA OF THE THREE GORGES PROJECT

In combination with the migration of industrial projects to be in undated in thereservior area of The Three Gorges project, a level analysis apptoach is used to formulate a policy-making model of invest optimization for the projectS to be migrated,in which various kinds of influ-encial factor on the projects are presented quantitatively and the restriction of limited resourccs isconsidered; An effective,overall and aaplicablc policymaking approach is provided for the migrationof the Three Gorges project.     

OPTIMIZATION DESIGN OF ADVANCED CORRECTION OF THE CONTROL SYSTEM BY A PASSIVE NETWORK

Optimization design of correction of the control systemby a passive network is studied in this paper.The design method guan-rantees collocation of a closed loop pole in a desired position,but alsominimizes the gain of the system amplifier,thus making the technicalrealization of the system easier.The design method is proved in thepaper.     

AN IMPROVED METHOD OF CALCULATION FOE UNSYMMETRICAL OPEN CONDUCTOR STATES IN THREE-PHASE POWER SYSTEMS

In this paper, the superposition and compensation theorems are employed to calculate the electric values under the unsymmetrical open conductor states in the three-phase power systems without modifying the bus admittance or the impedance matrices of the original networks. In cotrast with conventional algorithms, the method proposed here is highly accurate, fast, convenient and flexible. It can be applied to the unsymmetrical open conductor calculations which offered in power systems for its design and operation, to determine the settings of relay and automatic deyices, as well as accident analysis.