SIMULATION: Transactions of The Society for Modeling and Simulation International

Aytug, Haldun; Dogan, Can A.; Bezmez, Gokce

doi: 10.1177/003754979606700103pmid: N/A

In this paper, a method to determine the number of kanbans in a pull production system by using simulation metamodeling is described. The method is demonstrated on a two-card kanban- controlled manufacturing system. Through meta modeling, a relationship between the number of kanbans and the average time to fill a customer order is determined. Later this relationship is used in a model to determine the number of kanbans while minimizing costs.

Wildberger, A. Martin

doi: 10.1177/003754979606700104pmid: N/A

Pack, Daniel J.

doi: 10.1177/003754979606700105pmid: N/A

In the context of controlling an inverted pendulum, the novel ideas presented in this paper relate to i) the design of a fuzzy logic controller; ii) the design of a neural-network controller; and iii) implementation of a nonlinear controller based on differential- geometric notions. These novel ideas are presented in a comparative setting where five different control schemes are compared: a proportional and derivative controller, a linear quadratic controller, a nonlinear controller, a neural network controller, and a fuzzy logic controller. The paper shows how the controllable portion of the four dimensional space of control variables changes with the different control schemes. This is done by defining an "effectiveness coefficient" that is the ratio of the portion of the size of the controllable region to the size of the overall space as spanned by the position variables. The overall conclusion may be summarized by the following values of the effectiveness coefficient for the five different control schemes:

Comair, Claude; Chu, Jason; Ly, Van; Ghali, Prasanna

doi: 10.1177/003754979606700106pmid: N/A

This paper depicts the advances made by our team in the fields of computer science, mainly computer compiler writing and interpreter writing, to define a computer language oriented to solving problems in the field of emergency simulation, database management, interprocess communication and network programming. In this paper, we present a simple model of a structure being subjected to the various effects of a tremor. In the case study presented here, the building is designed to withstand a certain force beyond which a partial or total destruction will occur. The computer model developed in this paper will show at which point the structure will start to collapse as well as the evaluation of the casualties that may result from such destruction. The result may be used by a professional team of experts in various fields in order to study the various scenarios that may occur if a tremor hits the structure. Evacuation or emergency response operations could be planned in advance. Other emergency situations such as mass migration of population due to other natural disasters such as floods, tornados, and fire can be studied and simulated.

McLeod, John; McLeod, Suzette; Ford, Andy

doi: 10.1177/003754979606700107pmid: N/A

This month, in line with our policy of sometimes publishing information on work planned, or in progress, rather than "carved in stone," we present the first part of QUEST, an article which we received from Dave Biggs of SDRI, University of British Columbia. Note that this project is one that is still in the development stage, and the authors invite suggestions and comments from readers. It is believed that such feedback can be more helpful now than later.The second half of the writeup is scheduled to appear in the August issue of this column.