Showing papers by "Iran University of Science and Technology published in 1988"
TL;DR: In this article, a cycle ordering algorithm is given for bandwidth reduction of transformed element flexibility matrices, which is a direct approach and selects cycles having the least possible overlaps, and also an indirect method is also presented which generates cycles of the smallest possible lengths on an ordered member-set of a structure.
Abstract: An algorithm is developed for the generation of cycle bases leading to highly sparse transformed element flexibility matrices for an efficient flexibility analysis of skeletal structures. This method is a direct approach and selects cycles having the least possible overlaps. An indirect method is also presented which generates cycles of the least possible lengths on an ordered member-set of a structure. A cycle ordering algorithm is given for bandwidth reduction of transformed element flexibility matrices.
18 citations
TL;DR: In this paper, methods for the study of the topological properties of skeletal structures were presented for determining the degree of statical indeterminancy of structures, together with Euler's polyhedra formula.
14 citations
6 citations
TL;DR: In this article, methods for the study of the topological properties of skeletal structures are presented for determining the degree of statical indeterminacy of structures and the counting process in the presented methods is considerably simplified for space structures.
Abstract: Methods are presented for the study of the topological properties of different types of skeletal structures. An application of these methods together with Euler's formula, results in some new approaches for determining the degree of statical indeterminacy of structures. The counting process in the presented methods is considerably simplified for space structures.
Es werden Methoden zum Studium der topologischen Eigenschaften verschiedener Typen von Geruststrukturen angegeben. Eine Anwendung dieser Methoden unter Einbeziehung der Eulerschen Formel ergibt einige neue Ansatze zur Bestimmung des Grades der statischen Unbestimmtheit von Strukturen. Fur Raum-Strukturen vereinfacht sich der Zahlprozes bei den vorgestellten Verfahren betrachtlich.
2 citations
TL;DR: The Makrovian waiting line model has been emplayed and a general solution to estimate the effect of memory conflict on the average number of waiting units in the system, idle and busy periods for memory unit, system efficiency, the stretching factor of program on bases of "First Com, First Served" descipline is obtained.
Abstract: In a multiprocessors configuration, a memory conflict occurs whenever two or more processors or I/O, s attempt to access the same memory unit simultaneously. The overall effect of these conflicts are lose of the system efficiency. A multiprocessor activity during execution of a program has been considered as a stochostic process which moves through a countable set of states. The process decides where to go next by a random mechanism which depends only on the current state and not on the previous history or even on the time. This kind of process is called Markov process. The transition from any state is possible only to the neighbouring states due to these conditions that the arrivale of request rate from processors and the memory communication rate follow a poisson distribution. Under these assumations a multi-server waiting line model has been developed for a multi-processors organisation. The basic motivation for this investigation will be the search to find a set of system parameters to measure the multiprocessors. performance with multi-memory nuits.The Makrovian waiting line model has been emplayed and obtained a general solution to estimate the effect of memory conflict on the average number of waiting units in the system, idle and busy periods for memory unit, system efficiency, the stretching factor of program on bases of "First Com, First Served" descipline.The simulation programs written by Basic to implement the developed waiting line model are general enough so that a system configuration of any size can be studied.
2 citations
TL;DR: In this paper, an efficient algorithm is developed for generating subminimal cycle bases of graphs, where an expansion process is employed and independent cycles of prescribed lengths together with minimal cycles on unused edges are generated.
2 citations
Journal Article•
TL;DR: A two-state Markovian maintenance process where the true state is unknown will be considered and it is shown that if certain condition is satisfied, then it is possible to find the average cost per period by a simple calculation.
Abstract: In this paper a two-state Markovian maintenance process where the true state is unknown will be considered. The operating cost per period is a continuous random variable which depends on the state of the process. If investigation cost is incurred at the beginning of any period, the system wit I be returned to the "in-control" state instantaneously. This problem is solved using the average criteria. The method involves exploiting the structure of the problem to develop an algorithm which is shown to be more efficient than the usual dynamic programming approach. Results of extensive tests show the accuracy of this algorithm. In addition, it is shown that if certain condition is satisfied, then it is possible to find the average cost per period by a simple calculation.
2 citations
TL;DR: A markovian waiting line model have been developed for various different multi-processors configurations, with shared memory, and the system is analysed at the request level rather than job level.
Abstract: This paper is primarily concerned with theoretical evaluation of the performance of multi-processors system. A markovian waiting line model have been developed for various different multi-processors configurations, with shared memory.The system is analysed at the request level rather than job level.
1 citations
01 Jan 1988
TL;DR: The Cauchy-Navier equation of motion for the linear elastic isotropic continuum, for the vanishing body forces, may be written in the form ==================672======676======Open image in new window.
Abstract: The Cauchy-Navier equation of motion for the linear elastic isotropic continuum, for the vanishing body forces, may be written in the form
Open image in new window