SIMULATION: Transactions of The Society for Modeling and Simulation International

McLeod, John; McLeod, Suzette

doi: 10.1177/003754977702800110pmid: N/A

doi: 10.1177/003754977702800101pmid: N/A

Watt, Kenneth F.

doi: 10.1177/003754977702800102pmid: N/A

Adam, Yves

doi: 10.1177/003754977702800103pmid: N/A

Shallow coastal seas are the "priviledged" places for the dumping of wastes of all kinds: sewage, mud re leases, and chemical refuses are typical examples. In most cases, the shallow coastal seas are therefore very polluted. This paper describes a digital simu lation of the diffusion and transportation of pollu tants released in the shallow sea bordering Belgium. The model of course has much wider application. The principal new development in this paper is the method of integration of equations which describe such systems.The equations of the model have dominant advection terms, mixed derivatives, and nonlinear interaction terms, and are solved by a special predictor- corrector scheme consisting of three distinct steps. The mixed derivative is separated into second deri vatives along the grid axes and an auxiliary axis. The first two steps (implicit and locally one-dimen sional) form the predictor. The third one is the corrector, and it yields a consistent discrete approximation of the time derivative. The accuracy is 0(τ2 + τh + h2). A stability condition is derived and some problems in implementing the method are discussed. The paper concludes by presenting the results of a simulation of pollutant dumping in the North Sea near Ostend.

Taylor, Fred J.

doi: 10.1177/003754977702800105pmid: N/A

A common problem in system simulation is producing the solution to a differential equation of the form x(t)= Ax(t) + Bu(t), where A and B are constants. In particular, simulation often requires solutions for a step, ramp, or constant-acceleration forcing function. Standard numerical integration methods may fail or be extremely slow when implemented on a mini computer because of its short wordlength. This paper presents a new deterministic integration method which will accurately and rapidly produce the solution. Some numerical experiments are shown to demonstrate the new method.

Leventhal, Lance A.

doi: 10.1177/003754977702800106pmid: N/A

This article begins our discussion of microcomputer architecture. We briefly consider the basic features of computer architecture and describe the functions of the various sections of a computer. We then dis cuss the memory and input/output sections in more detail and show how these sections are implemented in microcomputers and how standard logic elements and special-purpose LSI interfaces are used.

Leventhal, Lance A.

doi: 10.1177/003754977702800107pmid: N/A

Lange, Allen S.; Birta, Louis G.

doi: 10.1177/003754977702800108pmid: N/A

Leventhal, Lance A.

doi: 10.1177/003754977702800109pmid: N/A

Hirschman, Elizabeth C.; Bellenger, Danny N.; Robertson, Dan H.

doi: 10.1177/003754977702800104pmid: N/A

Simulation appears to be a promising tool for applied market ing researchers. Marketing executives, however, have not yet learned to appreciate its value. This paper presents the re sults of a simulation study of the effects of subway construc tion on retail traffic flows and sales. It is to be hoped that this study and others like it will help to show the potential value of simulation to marketing management.