Sharif Digital Repository

There are many linear and nonlinear programming problems with uncertain parameters and variables. These types of linear and nonlinear models are called fuzzy linear and nonlinear programming problems. Solving such problems is important, due to applications and variety of these models. Here, we first review various types of fuzzy linear programming problems based on the models or the solution methods. Next, we revise a method due to Kerre to compare two unipolar LR fuzzy numbers and present some new results on the comparison of LR fuzzy numbers. Then, we solve linear programming problems with unipolar fuzzy numbers by our proposed time varient particle swarm optimization (TV-PSO) algorithm.... 

A special steel beam-to-column connection, named Khor-jini, is commonly used for steel framing system in Iran. In this system, two continuous beams are passed next to the columns and are connected to the column side using seated brackets.This type of connection has been common in Iran from the late past. Unfortunately, the seismic behavior of Khorjini frames had not been sufficiently studied prior to Manjil Earthquake of 1990. Due to very large damages which occurred in steel structures especially in connections during the said earthquake, the seismic behavior of this type of connection was studied and some of its weak points were recognized.In this study non-linear... 

Cloud computing is a way to increase capacity or add capabilities dynamically without investing in new infrastructure. The purpose of this project is the use of specialized algorithms for efficient energy management for cloud computing environments.One of the issues that is very important with respect to cloud computing is considering lifetime of servers or physical machines. Servers are some of the most important and critical elements of cloud computing. Server costseffect on the costs of the entire cloud computing system and the interference of serverseffects on entire system. Lifetime of each sever is dependent on a few factors, the most important of which is the number of switching... 

In the present research, model-based reasoning is introduced and explained based on Giere’s explanation of model. In other word, this research could be regarded as a reconstruction of model in Giere’s books and papers due to prpose a clear explanation of model-based reasoning. In the second chapter, after the introduction, the concept of model in Giere’s distinguished book, “Explainnig Science: A Cognitive Approach” (1988) is introduced and analyzed. In the second chapter, however, the concept of model in Giere’s recent works is traced. “An agent-based account of model” and “focusing on functionality rather than ontology” could be explained as the two important differences between his... 

In the preceding years, hydroxyapatite (HA)-based coatings and scaffolds have been known as the best biomaterials for dental and orthopedics applications. Biocompatible and bioactive hydroxyapatite-based Coatings on metallic implants is one of the best methods for reaching both suitable mechanical properties and appropriate bioactivity, leading to better osseointegration and osteoblast proliferation. The ultimate goal of this project is characterization as well as mechanical and electrochemical behavior investigation of Hydroxyapatite- Chitosan nanocomposite coating by electrophoretic deposition (EPD) method on Plasma Electrolyte Oxidation (PEO) treated titanium substrates and Magnesium (Mg)... 

The need for planning for the management and recovery of flare gases is an important issue in the energy sector of the country. On a day, about 46 million cubic meters of gas in Iran is burning in the torch, which in addition to the destruction of non-renewable energies, contributes to environmental pollution and emissions of greenhouse gases. Gas burning is one of the few pollutant activities that is due to short-term economic revenues, system design weaknesses, and lack of management in the operation process, with no service provided or value added. Iran is ranked third in the world according to satellite data among the countries that are burning flares. Accordingly, by burning 17/7...