Showing papers by "Applied Science Private University published in 1975"

Liquefaction Potential at Ekotisk Tank in North Sea

Abstract: Design of a 93-m diameter x 90-m tall oil storage tank and production platform for the Norwegian North Sea required an investigation of the stability of the dense sand foundation against liquefaction from the wave-induced cyclic loads on the structure. The results of special cyclic loading triaxial tests, interpreted in terms of the expected maximum storm conditions, demonstrated the adequacy of the foundation and illustrated a number of new aspects concerning the liquefaction potential of sand under cyclic loading.

Optimal Dyadic Models of Time-Invariant Systems

Abstract: The ease of simulating a dyadic model on digital computers suggests approximating linear time-invariant (LTI) systems by dyadic models. Methods for calculating the best such approximations are provided. It is shown that the matrices characterizing the LTI system and its optimal dyadic approximant have identical diagonal elements in the Walsh domain. This fact is used to derive a direct transformation between the impulse-response function of an LTI system and that of its dyadic approximant. The transformation can be accomplished in less than N log N additions.

Multi person decision analysis in large-scale hierarchical systems—team decision theory†

Abstract: This paper represents a portion of a study of decision analysis in large-scale systems in which an effort is made to attack problem complexity by taking advantage of any inherent structure in the problem By arranging the elements in the problem in an appropriate graphical form, usually a tree or hierarchy, it may often be possible to decompose the problem into a number of loosely coupled subproblems which can be solved independently and then coordinated in such a way as to provide a solution to the overall problem We first survey team decision theory in which a multiplicity of decision makers, each of whom has access to different information, is attempting to extremize the same cost function Under the conditions of a linear system with quadratic costs and Gaussian noises, the solution of a static team problem, in which no member's decision affects any other member's information, reduces to the solution of a set of linear algebraic equations A large class of dynamic team problems which possess certain

Renormalization for the Wiener Hermite Representation of Statistical Turbulence

Abstract: Publisher Summary One of the methods of treatment of statistical turbulence involves the use of the Wiener Hermite (WH) representation that has been used with some success in the treatment of diffusion problems This chapter describes some manifest arbitrariness or the representation to improve convergence by calculating for the process using one of the presently available representations Readjustment is done to improve convergence, and the calculation is started with these renormalized values The chapter suggests that W H representation is adequate for moderate Reynolds numbers and for moderate times, for the representation of (decaying) initial value problems of interest in turbulence theory When these conditions are not met, the representation becomes progressively more poorly convergent The renormalization proposal offers hope of considerable improvement in the convergence of the representation under these more demanding circumstances If the renormalization procedure yields significantly improved results in a full scale computation, it will next be applied to the real fluid mechanics problem and to diffusion problems There is more flexibility in the choice of the functions for such problems, and it might be anticipated that the renormalization procedure will be even more effective in their treatment

Thermodynamics of the α-AuZn and β'-AuZn phases

Abstract: Thermodynamic data of theα-AuZn alloys recently reported in the literature are found to follow closely the sub-regular solution model. Values of the two parameters for this model are found to increase linearly with temperature. Using theα-phase data, the established(α + β′) phase boundaries, the thermodynamic activities of Zn in theβ′-phase, the theoretical equations of Chang and co-workers for ordered phases and the calorimetric value of the stoichiometric alloy, the thermodynamic properties of β1-AuZn alloys are obtained. It is found that the thermal entropy of the β1-AuZn phase is essentially independent of composition, verifying one of the assumptions made in the theoretical equations of Chang and co-workers. The large discrepancies between the three sets of experimental data for β′-AuZn phases are discussed and best consistent results are reported.