SHAHID CHAMRAN UNIVERSITY JOURNAL OF SCIENCE
Year:2007 | Volume:NEW SERIES | Issue:16 (SECTION A)|Papers Count:12

Private industries encounter failure more quickly in comparison with non-private units because they receive limited financial, specialist human resources and less capital support. Consequently due to the effect of industrial developments on the improvement of economical condition, it is necessary to examine the problems causing reduction or stopping industrial productions trend, specially in private industry. Required information is obtained with the help and use of available information in the organization of industries and questionnaires handed out to the managers of industrial units to find different failures and effective causes of them. Constitution of Khouzestan industrial organization until the end of Mehr 81 is being the juncture of the study. A sample was obtained from Ahvaz exploited non-private units by proportional sampling and selected control, the size of which is 206 units.Analysis of collecting information is carried out by competing risk model. In fitting this model to the data we use the Cox proportional hazards model. Capital, management and sales reduction problems are considered as the failure causes in this research.

In this paper, we state the general form of the Cable-Khodro (automobile Cable) problem. First, we model the problem in the form of the linear programming problem of the type of mixed variables. Then we model the problem in the form of the nonlinear programming of the type of mixed variables in which the factory of the Cable-Khodro of Sabzevar is a special case of the model. Finally, we obtain the optimal solution of the factory of the Cable-Khodro of Sabzevar for the following cases: four kinds of wires with two optimal lengths, three kinds of wires with three optimal lengths, and four kinds of wires with three optimal lengths.

A project consists of a set of activities with precedence relations. There is also a set of limited resources with which one can perform the activities. Each activity may be executed in more than one manner, depending on which resource(s) is (are) assigned to it. The objective of the limited resource scheduling problem which is known as NP-hard is to find the starting time and the manner in which each activity is performed in order to minimize the project span. In this paper a solution procedure based on genetic algorithm is proposed. Each chromosome is encoded by 9 priority rules. In addition, chromosomes represent best solutions obtained between three cases of: (i) activities are performed at their earliest possible time, (ii) activities are performed at their latest possible time, and (iii) activities are performed at a time randomly selected from their time windows. To describe the solution procedure a numerical example is Presented.

The aim of this article is to solve the optimal shape design problem governed by a parabolic control system, defined according to a pair of geometric elements, the domain and its boundary, by embedding method. First, the classical form of the parabolic equation together with the boundary and the initial conditions are presented by integral equalities. Then, in a new formulation, the problem is shown as a minimization of a function on a set of positive Radon measures. By applying the suitable approximations and discretization on the appropriate spaces, this problem is also transferred to a finite linear programming one. In this manner, the solution can determine the optimal domain and optimal control at the same time. Based on this method, some numerical examples are also presented.

Tourism has always had a positive effect on the government's revenue and creating new occupations. But various factors, especially terrorism, can destabilize the revenue of tourism industry. Nowadays through investment for developing tourist resorts as well as its administrating expenses, governments try to increase their tourism revenue. On the other hand, terrorists try to decrease the effects of such investment by exhibiting violent actions. The aim of this study is to design a controlling system for the above model so that the governments play the major role in decision making process of the plan, thus maximizing the revenue. Using measure theory, we approximate this optimal control problem with a finite dimensional linear programming. The solution of this problem is used to find an approximation solution for the original problem. By solving this problem the approximate optimal control functions, i.e. the government's investment in two different parts of the plan, foundations of tourism and security-executing expenses are determined. By administrating this model the tourism revenue will be maximized.

Gas flow meter sensor is produced with thin film techniques. This sensor is of thermal type, and when gas flows over the heater, some thermal energy is. carried away, hence temperature difference is produced between two sides of the heater. Temperature sensitive element of this sensor is made of two Ni-Cr thermo arrays. This sensor can measure the flow within 10 Sccm to 10000 Sccm in the rectangular duct of cross section 1x15 mm2. Design, mask making, different deposition, lithography and etching of these layers are successfully done. Micromachining over glass for producing glass membrane is carried out. The results of the experiments on the behavior and response of this sensor is reported which showing the sensor response to be linear up to 1000 Sccm. A new geometrical design is proposed which will increase the sensitivity of the sensor.