Volume 13,Issue 4,1990 Table of Contents

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

Chen HuaZhou Jiaqi

1990, 13(4):1-6.

[Abstract](693) [HTML](0) [PDF 304.54 K](147)

Abstract:
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.

2 LOAD FREQUENCY CONTROL USING DECOMPOSED DISCRETE MODELS

Chen Ganping Qin Yihong Xu Guoyu

1990, 13(4):7-13.

[Abstract](575) [HTML](0) [PDF 372.45 K](152)

Abstract:
Decomposed discrete models, can be used to design load frequency' controllers in multi-area power systems.Considering the exchanging real power in tie-lines as a measurable disturbance, the multi-area power system is decomposed into several subsystems.On the basis of generalized minimum variance control principles, an expanded control rule is induced. Using discrete models, the proposed method greatly decreases the number of varialles in be measured and simplifies the control system. The method is illustrated with a two-area power system example and its simulation Jesuits.

3 THE NEW PHASE SELECTION SCHEMES ON USE OE FAULT COMPONENT

Yao Zaoxin Ye Yilin

1990, 13(4):14-22.

[Abstract](601) [HTML](0) [PDF 370.37 K](136)

Abstract:
In accordance with the characteristic of digital relay and fault locatoin four methods of phase selection on fault component are presented in this paper.These methods are simple in principle, reliable in action, and immune from load flow,system oscillation.Hardly affected by fault location, source impedance and fault resistance, they can select fault phase reliably for any power system and fault type.As phase selection schemes, they can be used for perfect digital relay.

4 DEVELOPMENT OF COMPUTER AIDED PROCESS PLANNING SUBSYSTEM FOR A CAD/CAPP INTEGRATED SYSTEM

Yi Shuping Wu Yuanyi Xu Xiangsui

1990, 13(4):34-40.

[Abstract](518) [HTML](0) [PDF 316.47 K](143)

Abstract:
Based on Group Technology, a CAD/CAPP integrated system is developed. This paper mainly covers the research work of the CAPP subsystem. In this subsystem, geometric and manufacturing information is obtained from the CAD data base, modular block programming and full Chinese menu are adopted, process planning is produced with the semi-generative method, and process card involved the operation charts is yielded by printer. The operation is simple and convenient, and the performance is quick. The ? CAPP subsystem is successfully integrated with the CAD subsystem. The subsystem is an advanced CAPP system.

5 NUMERICAL SIMULATIONS OF THE SOLIDIFICATION PROCESS IN HEAVY STEEL CASTINGS AND THE SHRINKAGE CAVITY PREDICTION

Chen HaiqingChen DeyinLi Huaji Zhou Desheng Peng Shufang Wu Jian

1990, 13(4):41-48.

[Abstract](540) [HTML](0) [PDF 376.21 K](166)

Abstract:
In this paper a numerical simulation software of the casting solidification process is designed with the implicit alternating direction method (i,e IAD) and the TRUE BASIC language. The solidification process of the cross-section A-A of the high pressure inner cylinder is simulated and the shrinkage cavity position is predicated by means of utility software. The simulation is agreeable to the measurement.

6 REALIZATON OF EXPERIMENTAL MODAL ANALYSIS ON MICROCOMPUTER

He Yusheng Li Keqiang

1990, 13(4):49-56.

[Abstract](505) [HTML](0) [PDF 361.40 K](228)

Abstract:
The engineering circls at home and abroad are attaching great importance to the technology of experimental modal analysis. The expensive special equipment is needed while analysising, so the application is limitted. The development of microcomputer modal analysis system is studied. Based on its theoritical description the microcomputer system is presented. After a series of tests and analysis, the rationality and correctness of this system is verified and has been applied in engineering.

7 A METHOD OF SYSTEM IDENTIFICATION AND MODEL REDUCTION BASED ON TIME-DOMAIN RESPONSE OF A DYNAMIC SYSTEM

Wang Tingkai Wang Lichun

1990, 13(4):57-65.

[Abstract](686) [HTML](0) [PDF 339.69 K](140)

Abstract:
This paper combines model reduction with system identification by means of time-domain function approximation, and presents a new time domain method of direct identification of linear reduced model and model reduction, and demonstrates existence theorem of its solution and criterion of order determination. Simulation tests show that the method is simple, accurate with few data requirement.

8 THE PERFORMANCE EVALUATION OF RELATIONAL DATABASE ON B~+ TREE INDEX

Zeng Yongning

1990, 13(4):66-73.

[Abstract](484) [HTML](0) [PDF 323.27 K](158)

Abstract:
An approach for evaluating the performance of relational database is introduced, the stroage cost, responding time and maintenance ccst oi a relational database based on B+ tree index are theoretically analyzed, and the evaluation model is proposed

9 THE APPLICATION OF MULTIBODY DISCRETE METHOD IN RING''''S VIBRATION ANALYSIS

Yin Xuegang Wang Ya

1990, 13(4):74-83.

[Abstract](572) [HTML](0) [PDF 365.47 K](886)

Abstract:
A ring's muJtibody discrete model is discussed in this paper. The ring's plane geometric nonlinear vibration equations are derived. Compared with the finite element and lump mass methods, this method is better. In the last pa it of the paper, the eigenvalues, the first 9 modes of the ring, the geometric nonlinear dynamic responses of the ring are calculated.

10 A STUDY OF PHOTO-ELASTIC EXPERIMENT TO FRACTURE PROCESS OF LIMESTONE SPECIMEN WITH PRE-CRACKS

Li Xin Li He Wan Ling Xu Jiang Yin Guangzhi

1990, 13(4):84-86.

[Abstract](481) [HTML](0) [PDF 168.62 K](805)

Abstract:
In this paper, the fracture process of specimen with pre-cracks is studied by using photo-elastic expe' merit.The analysis results of cracks stress field show that because the inter-effection appears between the the two cracks and the tensile fracture occured when the tensile stress concentration reaches to a certain degree, and cracks link up with each other, macroscopic failure will gradually result. Positions of cracks will have different effections to speciment's fracture.

11 A SDUDY ON THE LOCKING PERFORMANCE OF THE SYSTEM FOR HEIGHT OF MG150-WD COAL SEAM SHEARER

Tian Bo Ying Zhengxi

1990, 13(4):87-96.

[Abstract](428) [HTML](0) [PDF 467.96 K](918)

Abstract:
In this paper, based on the automatic-control theory, the time and frequency response of the hydraulic control system for height of MG150-WD coal shearer are analysed, and the steady and dynamic locking performance tests are made. The results show that the locking performance is satisfactory.

12 RANDOM SIMULATION OF THE PRODUCTION SYSTEM OF A MINE

Cao Shugang Qi Qingjie

1990, 13(4):97-103.

[Abstract](456) [HTML](0) [PDF 344.31 K](1123)

Abstract:
The production-transportation system in a mine is analysed with the principle of system analysis in this paper and the working process of this system is simulated with the technology of random simulation in a computer. Finally, the optimal projects of designing and administering are put forward.

13 THE EQUATION OF STBING IN THE EXTERNAL FIELDS

Wang Shaofeng Yang Xueheng

1990, 13(4):109-118.

[Abstract](541) [HTML](0) [PDF 319.04 K](850)

Abstract:
The classical equations of string in the external fields deduced with Kaluza's method. A solution of the equations for uniform magnetic field is got by means of differential geometry technlqde.

14 THE BIFURCATION PROBLEM OF TRIPLE-MOLECULAR MODEL WITH LOW CONCENTRATIONS

Zhou Jin Chen Junping

1990, 13(4):119-121.

[Abstract](536) [HTML](0) [PDF 111.87 K](597)

Abstract:
In this paper, we use the Hopf bifurcation theory to investigate the bifurcation problem of triple-molecular reaction model with low concentrations.

15 VARIATION OF LOCALLY LIPSCHITZ FUNCTION ON FINSLER MANIFOLD

Ma Renyi

1990, 13(4):122-126.

[Abstract](763) [HTML](0) [PDF 201.57 K](694)

Abstract:
In this paper, we generalize the generalized gradient of clarke on Banach manifold to the case of Finsler manifold and discuss the variational property of corresponding locally Lipschitz function, such as pseudo-gradient vector field, deformation lemma and Morse inequality.

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