摘要:

AbstractThe growing complexity of models and the expanding availability of techniques do not fit adequately into the possibilities of Kendall’s famous classification. Even most ge-neralisations fail to cope with simulation models successfully. In the present paper it is tried to present an alternative shorthand notation that is able to give an adequate and unambiguous specification of most queueing models, both analytical and simulation models, at the cost of a somewhat more complex structure than Kendall’s. As such it should be suited to characterise simulation models with almost the same ease as simple analytical models can be defined, without sacrifising clarity to ambiguity.

ISSN:0228-6203    

DOI:10.1080/02286203.1982.11759773

出版商:Taylor&Francis    

年代:1982

数据来源: Taylor

摘要:

AbstractThe paper discusses current limitations of Markov methods when compared with Monte-Carlo techniques and suggests how these limitations may be overcome. A top-down Markov modelling strategy supported by interactive graphics software, which is currently under development, is described. The use of Markov processes in conjunction with Monte-Carlo models for fault-tolerant simulation is also outlined.

ISSN:0228-6203    

DOI:10.1080/02286203.1982.11759774

出版商:Taylor&Francis    

年代:1982

数据来源: Taylor

摘要:

AbstractThe properties of the software-packages GPSS-FORTRAN are described. The GPSS-FORTRAN simulator is a Fortran program-package. It consists of a chassis, the main program, into which calls to the modules, GPSS-FORTRAN's subroutines are inserted. Its oonstruction makes it superior in several respects to its grandparent, GPSS. Other simulation languages and tools for the analysis of discrete systems such as GPSS, SIMULA, SIMSCRIPT and GASP are compared with GPSS-FORTRAN.

ISSN:0228-6203    

DOI:10.1080/02286203.1982.11759775

出版商:Taylor&Francis    

年代:1982

数据来源: Taylor

摘要:

AbstractThe Department of Nuclear Science and Technology at the Royal Naval College Greenwich is responsible for the postgraduate training of personnel in the design and operations of pressurised water reactor propulsion systems used in the Royal Navy.A major part of the training is based on modelling various parts of the system to demonstrate their dynamic performance, building up to a total system model describing the interface between each of the subsystems. It is also necessary to demonstrate at an early phase of the training the importance of the man/machine interface and the operators role in the system failure situations.The paper describes the development of this simulation and discusses some of the results achieved in training operators and designers using these modelling techniques.

ISSN:0228-6203    

DOI:10.1080/02286203.1982.11759776

出版商:Taylor&Francis    

年代:1982

数据来源: Taylor

摘要:

AbstractThis article describes the UBe of simulation to design a flexible computer controlled manufacturing system (FMS).The simulation model described is designed to determi ne the best layout of the operative units of the system and to find a near-optimal control policy to be implemented on the central control processor for real time monitoring of the entire system.The program provides a discrete simulation and is structured in several extremely specialized functionally oriented modules, some of which are user implemented in a man-machine colloquium. The main control modules following suitable optimal criteria such as maximum productivity and minimum cost, have the followv.Tg tasks: to order the activities on the basis of the actual queues, to choose the operative units more profitably in order to carry out these activities by analyzing the actual system status and configuration.To accomplish the simulation purpose, the program supplies the user with numerous statistical parameters giving a significant picture of the behaviour of the single machi nes and of the entire system. This picture will isolate critical items and its analysis may suggest modifications able to improve system efficiency. A practical application of the simulation program to a production center design is also given.

ISSN:0228-6203    

DOI:10.1080/02286203.1982.11759777

出版商:Taylor&Francis    

年代:1982

数据来源: Taylor

摘要:

AbstractWhen in search of a solution for a problem in ecology or in the field of water resources the physical system has to be quantitatively specified. Such a specification is most concisely given under the form of a mathematical model. Not only important parameters and physical constants are provided, but also relationships between variables are presented. System theory gives a general answer concerning the constituent parts of the mathematical model representation. The elements are : a frame a structure and a parameter set. The frame specifies the input, output and state sets, the structure includes the functional relationships between set elements and the parameter set groups the physical constants. Whenever important ecological parameters like coefficient, etc., have to be found, parameter estimation permits to extract those constants out of the measurements. For a given frame, the parameter estimates will depend on the choice of the structure. The precise form of the structure is often a matter of debate. A parameter estimation procedure based on normalized sensitivity functions is developed. The scheme has the advantage of limiting errors which result from similar but wrong model structures. Robustness towards structural ambiguity is obtained.

ISSN:0228-6203    

DOI:10.1080/02286203.1982.11759778

出版商:Taylor&Francis    

年代:1982

数据来源: Taylor

摘要:

AbstractThe paper describes a digital model of a 3-phase synchronous generator feeding a current-controlled active load through a thyristor bridge rectifier directly in phase quantities. The equations'of the model are developed in a form suitable for the study of both transient and steady state operating conditions of non-salient pole machine. The equations are given for both open and closed loop operations. They are solved by use of the method of recurrence. Different modes of operation of the thyristor bridge are studied. Numerical results for both open and closed loop operations are given.

ISSN:0228-6203    

DOI:10.1080/02286203.1982.11759779

出版商:Taylor&Francis    

年代:1982

数据来源: Taylor

摘要:

AbstractThe goal of this paper is to study threedimensional simulation of tumor growth in a nutrient medium. For this purpose a cell cycle model for a t'lmor ce 11 and rules for its multiplication have been developed. Algorithms and program packages habe been constructed describing the spatial and temporal tumor growth.A selected case study shows the simulation of tumor growth and its treatment by chemotherapy.

ISSN:0228-6203    

DOI:10.1080/02286203.1982.11759780

出版商:Taylor&Francis    

年代:1982

数据来源: Taylor

摘要:

AbstractThis paper Introduces the different concepts of stochastic transfer function modelling as applied to the synchronous machine. Two transfer function models are fitted to the machine data collected under normal operating conditions. The adequacy and lack of fit of the fitted models is verified by means of several diagnostic checks on model residuals. Also, the use of the models to forecast the output series is illustrated.

ISSN:0228-6203    

DOI:10.1080/02286203.1982.11759781

出版商:Taylor&Francis    

年代:1982

数据来源: Taylor

摘要:

AbstractThe problem of determining the maximum amount of groundwater that can be extracted from a one dimensional cross section in coastal leaky aquifers at steady state is treated in this paper. Based on Darcy's law, the principle of mass balance and the Ghyben-Herzberg relationship, differential equations that model the steady state response of the aquifer piezanetric head to water extraction are derived. It is shown by using a discrete version of the model, in the region without seawater interface, that the problem of determining the optimal pumping strategy can be solved iteratively using linear programming technique. Simulation results are furnished about two cross sections in the Nile Delta aquifer which indicate that the amount of water currently pumped from those sections can be substantially increased without any adverse effect from the seawater intrusion.

ISSN:0228-6203    

DOI:10.1080/02286203.1982.11759782

出版商:Taylor&Francis    

年代:1982

数据来源: Taylor