Showing papers on "Verification and validation of computer simulation models published in 1974"

Comments on models of multi-processor multi-memory bank computer systems

Abstract: This paper is concerned with processor degradation produced by access conflicts in multi-processor, multi-memory bank computer systems. Hardware and software parameters which influence performance are outlined and discussed. The incorporation of these parameters in analytic and simulation models is discussed with a view to the predictive merit of the model. Finally a general simulation model of a multi-processor is presented, and results based on its use are analyzed and compared with those of other models.

The simulation of computer systems in a university environment

Abstract: The spectrum of current work concerning the simulation of computer systems in a university environment ranges from simple interpreter-oriented simulation models for educational use through research into areas concerned with the development and refinement of techniques generalizing or simplifying the simulation process [37, 38]. When we speak of work related to the simulation of computer systems, we include the development and use of any software or technique which aids in the imitation of the stimulus-response relationship of any portion of a computer system. Thus, this survey paper discusses work concerned with the “emulation” of one machine (called a virtual machine) on another machine (called the real machine) as well as more conventional forms of simulation. These studies are prevalent in academia and are used for two distinct purposes: education and research. A topic of interest that frequently occurs in a research environment is the use of simulation models to create an environment in which some small portion of a total computer system can be tested. Popular examples of this area are job mix generators to test scheduling algorithm alternatives or reference stream generators to investigate paging algorithms. Included also in the area of environment creation are the software engineering systems, used to aid in the consistent design of computers, as may be best exemplified by Project LOGOS, [3, 28, 29]. These studies are of interest to our survey in that they liberally employ automated simulation during the design period.An area that has classically been popular in academic simulation studies is the creation and use of high level models for configuration studies, operating system tuning etc. This area represents the largest intersection of interest with investigators in government and industry. A final area of study included in this survey is the investigation to improve techniques for approaching the simulation problem, or the generalization of known techniques to develop some kind of theory or set of concepts for computer system simulation.

The use of simulation in the development and empirical validation of analytic models for emergency services

Abstract: Simulation models are generally costly tools to use in systems analysis. Whenever applicable, one prefers to use a simple analytic model. However, in many cases, the conditions assumed by solvable analytic models do not hold in the real world. But a simulation can be used to suggest an approximate model and to determine how good an approximation an analytic model is. We show how simulations of New York City's fire and police operations have been used to develop and validate simple analytic models which are now being used to determine the deployment of resources in these two services.

An appreciation of computer simulation

Abstract: Students learning computer simulation often are bewildered by the complexity of computer simulation models. To overcome this difficulty, we have used an exercise which requires modeling a simple system.The student constructs a model and performs hand simulation. Next, the student uses a program deck to perform computer simulation for the same problem. Finally, the student constructs an analytic model and compares the results of simulation runs with calculated results.Experience shows that this three-way exercise, involving hand simulation, computer simulation, and analytic model, gives the beginning student a feeling for and confidence in the validity of computer simulation.