SIMULATION: Transactions of The Society for Modeling and Simulation International

Thorn, Rodney

doi: 10.1177/003754977101700309pmid: N/A

doi: 10.1177/003754977101700301pmid: N/A

Nielsen, Norman R.

doi: 10.1177/003754977101700302pmid: N/A

Bohn, Paul F.

doi: 10.1177/003754977101700303pmid: N/A

Every simulation requires a good static check to be performed to insure that,initially, the equations being simulated match those of the analysis and, subsequently, to be sure that the analog computer's patchboards remain free from wiring errors. Custom arily the static check is prepared by hand using a desk calculator, since the time required for pro gramming a "one-shot" digital program is typically not a good investment. However, by utilizing the capabilities of a suitable simulation language (such as CSMP or DSL/91), digital static checks can be made economically in less time than that required for a hand-calculated check, especially in the case of hybrid computations. Also, with a little ingenuity, the efficiency of hybrid simulation can be greatly increased by combining the static-check calculation and automatic analog setup via the simulation-language static check. (Familiarity with analog programming and the use of simulation languages is assumed.)

Nance, Richard E.; Baker, Norman R.

doi: 10.1177/003754977101700304pmid: N/A

An industrial dynamics model of a university library, developed originally to investigate the effect of library control policies, is described. The model is used to analyze the effect of two policies pro posed by the Physics Library at Purdue University. After having operated under extremely crowded con ditions for the past several years, the Physics Library will move in 1971 into new, more spacious quarters. The policies for loans from the library collection have been rather free, control over the collection has been lax, and penalties for users failing to comply with library policies have been mild. The reasoning behind these policies was that if all loaned materials were returned, sufficient shelf space was unavailable.With the space limitations removed in the new quarters, the Physics Librarian can adopt one of two general policies:Policy 1 - Closer control over the library collection, more restrictive loan policies, more staff, and longer operating hoursPolicy 2 - Less control over the collection with more extended loan policies and increased purchases of multiple copies.Analysis of the two policies shows that Policy 1 effects a reduction in delays in return of loaned material at the expense of incurring user dissatis faction with the library and that Policy 2 results in even higher user satisfaction than is presently experienced.

Anderson, Thomas C.

doi: 10.1177/003754977101700305pmid: N/A

At the 1968 FJCC Hsu and Howe presented an itera tive hybrid method for solving partial differential equations. The method allows the solution of prob lems requiring a large number of nodes in its representation through time-sharing the analog com ponents. The initial attempt to utilize this method showed that the accuracy of the solutions was extremely sensitive to the program parameters. This sensitivity was reduced to acceptable levels through the use of dynamic scaling and incremental equation formulations. The resulting implementa tion has been found to yield solutions of suitable stability and accuracy for practical applications.

Rideout, V.C.

doi: 10.1177/003754977101700306pmid: N/A

Holst, Per A.

doi: 10.1177/003754977101700307pmid: N/A

Moores, Chuck

doi: 10.1177/003754977101700308pmid: N/A