THE OBJECTIVES AND REQUIREMENTS OF MODEL MANAGEEMENT

Model management is a technology evolving by necessity, pushed by the attempts to deal with increasingly complex systems and the perceived inadequacies of past efforts. This rapid evolution of Model Management Systems (MMS) has created different perspectives of the role of the MMS; one arising the user's interaction with a model data bank and the other view from the in the database and decision support systems research community stressing modeling community emphasizing the model development functions. These two perspectives are clarified and reconciled by relating each to the model life cycle, which leads to a more comprehensive statement of MMS requirements

IMPLEMENTATION OF FORTRAN RANDOM NUMBER GENERATORS ON COMPUTERS WITH ONE'S COMPLEMENT ARITHMETIC

No abstract available

THE MIXED METHOD OF RANDOM NUMBER GENERATION: A TUTORIAL

Several motivations are recognized for user-defined random number generators in preference to built-in generators. The mixed method of random number generation is discussed) and the conditions for achieving full period with a modulus of 2^b are explained. Implementation of mixed random number generators is affected both by the computer and language used. Guidelines are presented for realizing acceptable mixed generators on several machines using the FORTRAN, PL/l and SNOBOL4 languages

Systems and Methods for the Electrodeposition of a Nickel-cobalt Alloy

Systems and methods for electrodepositing a nickel-cobalt alloy using a rotating cylinder electrode assembly with a plating surface and an electrical contact. The assembly is placed within a plating bath and rotated while running a plating cycle. Nickel-cobalt alloy deposition is selectively controlled by controlling current density distribution and/or cobalt content in the plating bath while running the plating cycle to deposit an alloy of a desired yield strength onto the plating surface in a single plating cycle. In various embodiments, the rotating cylinder may be used as an insitu monitoring method to assist in obtaining the properties desired

TO BE, OR NOT TO BE -- IS THAT THE QUESTION?

My purpose is to identify three fundamental questions regarding language standardization, to share with you my answers to these questions, and to explore the rationale emanating from these answers

A PROCESSOR UTILIZATION MODEL FOR A MULTIPROCESSOR COMPUTER SYSTEM

A processor utilization model for a simplified multiprocessor computer system is developed. Jobs are assumed to arrive according to a general input process, and each job is assigned randomly to an available processor. A finite capacity input buffer is used if no processor is available. The mathematical model is based on the busy period analysis, and two utilization measures are derived: (1) processor utilization when the system is busy (the fraction of processor occupation time during a busy period), and (2) global processor utilization (the fraction of processor occupation time during a busy cycle). Additionally, the arbitrary time state probability distribution is obtained and serves as the basis for the above measures in addition to others. Several approximations enable the development of a computational model from the mathematical model. Experimentation with the computational model reveals the sensitivity of the model to variability in the arrival process. Comparison of 2-processor and 4-processor systems from the operator perspective indicates a qualified preference for the behavior of the 2-processor system. This preference must be carefully interpreted since processor costs, the increase in overhead with an increase in processors, and behavioral variables reflecting the user perspective are excluded

A COMPARISON OF DISCRETE EVENT SIMULATION COURSES BASED ON A SMALL SAMPLE SURVEY

No abstract available

STYLITISM, SYNERGISM AND SYNCRETISM: THE INTERFACE OF COMPUTER SCIENCE AND OPERATIONS RESEARCH

The interface of computer science and operations research is described from a stylitic perspective. This position enables an honest appraisal of the disciplinary synergism often claimed for the two. Operations research emphasizes the development of algorithms and the implications therein; while computer science gives primary emphasis to the representation of algorithms and the implications of execution on a digital computer. The realization of a syncretic state can be claimed only for discrete event simulation and, to a lesser extent, for scheduling theory. To the extent that the "algorithm" can serve as common ground for both disciplines, a broader, more fundamental form of syncretism might be achieved

MODEL REPRESENTATION IN DISCRETE EVENT SIMULATION: THE CONICAL METHODOLOGY

Beginning with a brief review and classification of model development approaches, we characterize the simulation model life cycle as comprised of seven phases: the conceptual model, the communicative model, the programmed model, the experimental model, model results, use of the model for integrated decision support, and the modification and extension of of the model. This characterization places severe requirements on the task of model management (creation, acceptance, use, revision or extension, and reuse). The Conical methodology has been developed in response to the needs that predominate the model development phases (from conceptual model to model results). Definitions used in the Conical Methodology are explained, and the approach is illustrated with a machine repairman example. An incomplete critigue of the result and the approach concludes the paper

Contemplations of A Simulated Navel

The Model Development Environment Project has the goal of defining the software utilities and the database support needed for creating, validating, and experimenting with complex simulation models. This project review, emphasizing the needs and explaining some of the guiding concepts and principles, serves to underscore key issues extending beyond discrete event simulation. An introspective summary presents an optimistic reaction to the fear that technically naive modelers might use the more sophisticated capabilities to produce catastrophic results