Sharif Digital Repository

Products on Research and Development (R&D) are followed by Technology development. Projects on R&D are cost intensive and considerable of financial resources should be allocated. Optimal allocation of resources could be managed through cost effective strategy. Hence, a “Model for planning and development of technology” has been developed in the present work, which lends itself to the analysis of the industrial application of planning of technological development based on minimizing costs of both development and application of a technology. Mixed Integer Programming optimization model has been developed which enables studying the structure of R&D activities. This model is based on the concept... 

As a problem, generally, energy security components do not interfere with the calculation of the optimal energy supply situation. In this paper, we are looking to find a solution to make a framework of the impact of energy security on energy supply in order to obtain comprehensive analysis of the economic optimal point. Method is based on the competition of energy costs to meet demand during the study period. Threats that have been addressed in the energy security are seen as risky and stochastic parameters in the model. The nature of these parameters is of uncertainty type, therefore, based on the probable scenarios of the stochastic model, the perspective of the energy supply system is... 

Productivity is the effective usage of input or resources for production or output. Input (including Energy, raw materials, capital and work force), which is being used for output (including final products or services performed by an organization). Productivity, increases gross domestic product and competitiveness, and improves level of living. Firms and related management levels play the main role in improving productivity. Using productivity cycle management brings the productivity to improve as a permanent process, specifies the rout for productivity and prepares the ground. The most important step in productivity cycle (PDCA) is the measurement of productivity. In this research several... 

Since the number of Internet users for the services such as e-applications is increasing rapidly, authentication constrains more latency as well as load to the system. It is due to large number of users whose identity needs to be checked and compared individually, and the number of simultaneous authentication requests in a specific time. To solve the stated issues, this thesis proposes a new definition of group authentication and describes group authentication protocols. Group authentication is the verification of identity of multiple requests of users at the same time. In this protocol, the authentication server inputs the multiple authentication requests in a function, and then applies... 

In the recent years, there has been an increasing attention toward usage of ultrasonic for enhanced oil recovery practices. But, thorough knowledge of active mechanisms and spreading and characterization of developed fingers during this practice is not available. From the other hand, due to limited amount of light oil fields, more attentions towards recovery from heavy oils is the need of the hour. Documents show that the big issues during the enhanced oil recovery from heavy crudes are high density of reservoir oil as well as poor development of fingers during injection due to high mobility ratios. In this study, results of ultrasound effect on the heavy oil recovery and its effect on the... 

Nowadays, the world is full of multi criteria decision problems and all the people should make decisions in different situations. Sometimes, the result of a decision problem is so important as a wrong decision may result in a loss that cannot be compensated. Therefore a decision making tool seems as a must. On the other hand, in this era of rapid social and technological change leading to increasing life complexity, sensitivity analysis is an important issue in all decision making processes. Analytic Hierarchy Process and Analytic Network Process, as two common tools for multi criteria decision making, are widely used throughout the past decade in different fields. Designing the model and... 

The aim of this thesis was to find the optimum retention time for treatment of synthetic petroleum wastewater by a wastewater treatment system made with a bucket, mineral material and earthworms residing in a vermibed. In order to make the desired flow happen, height difference was utilized. The polluting substance used for making wastewater was BTEX. As the wastewater was synthetic, the concentration was also a variable. The ultimate soluble concentration was 3200 mg/l and more concentrations were not tested. Parameters such as number of worms, worm’s growth rate and their distribution pattern, humidity amount and distribution and worm’s acclimatization time during organic loading shock... 

In the present study, the factors that affect the IPO underpricing in the Tehran Stock Exchange are investigated. We define the variables of IPO percentage, age and size of companies, dummy variable for rounded IPO prices, market return in a month before the initial public offering, average return of IPOs that had been done during one month before the IPO of each ticker and the dummy variable for industrial group in which the company is located. We had to calculate the initial return of 246 companies that were offered in the years 1380 to 1395. In this study, due to the existence of a daily stock price volatility constraint, a new algorithm was introduced to calculate the dependent... 

In many biological populations, information about environmental conditions is acquired collectively, through information sharing among individuals, by exchanging signals. In order to achieve a better understanding of such systems, using methods borrowed from statistical physics, we introduce two mathematical models. First, a collective decision making model, for a community of individuals residing on a communication network, who live in an uncertain environment, in which individuals try to collectively find the environmental state. In the second model, a collective movement model, we consider a population of collectively moving individuals, in which individuals try to collectively find and... 

In this thesis, a new passive method suitable for Geolocating LPI radars is introduced. The method uses two Electronic Support (ES) receivers placed on a fast moving platform (e.g., an airplane or a satellite). The proposed method has a high processing gain, which makes it highly suitable for very weak LPI signals. The processing gain of the method was analytically derived and illustrated with simulation to determine if the proposed method can detect LPI radars in much lower SNRs compared to regular time-frequency LPI detection methods. Also, the resolution of the proposed method in both range and cross-range direction in radar location finding was analyzed. Furthurmore, the effect of the...