Sharif Digital Repository

One of the most modern types of inlets in aircraft is the Diverterless supersonic inlet, which is used in some new UAVs and fighters, and has many advantages over other types of inlets, especially in removing the boundary layer. The most important part of DSI design is the creation of bump geometry, which requires special precision and elegance. There are various methods for designing and creating bump geometry, some of which are mentioned in this report, and finally the method of creating bump geometry is selected based on the flow around the primary cone, which is in accordance with the analytical method and is in fact the most basic and widely used method.In this study, a DSI with cowl... 

Ever-increasing energy consumption and consequent extensive greenhouse gas (GHG) emissions have become two major global challenges for all human beings in the 21st century. If this trend of increasing energy consumption continues, our primary energy reserves willbe exhausted very soon.One solution is, shift of primary energy resources from fossil fuels to renewable energy could greatly reduce the current heavy dependence upon fossil fuels. Renewable energies have small share in the global energy market, therefore couldn't be a main method in the mid-term. Because of the low efficiency and consequent extensive GHG emissions of the conventional power generation that producing major amount of... 

Programmers often use object-oriented application frameworks, such as Eclipse, due to their several advantages, some of which are: providing a standard platform for designing and implementing software systems, enabling the reuse of both code and design,reducing the development’s time and costs, and increasing the maintainability of systems.However, frameworks evolve over time because of new requirements or fixing bugs. Therefore, the programs that had been written on top of those frameworks also need to evolve to become compatible with them; otherwise, they may crash.This thesis presents an approach that comprehends the evolution of frameworks through comprehending the evolution of the... 

Business Activity Monitoring (BAM) is a method for evaluating current condition of organization from the viewpoint of reaching to its strategic objectives and helps man-agerstobe informed straight forwardly about thecurren tstatu sofeach Key Performance Indicator (KPI). Enterprise Service Bus (ESB) is an infrastructure for transferring web services between some software components that performs in Service Oriented Archi-tecture (SOA) domain and its goal is improving interoperability between components.As BAM needs to interact with other systems to receive event flow and ESB assists this interaction, there is a need to define a general framework to establish communication between them and... 

Improving the network structure is one of the most important challenges in network research. Improving network structure is performed in order to achieve various goals such as refining routing and robustness.
Having an eye on the structure of a real packet switched communication network as an example, we have tried to improve its performance in those regards by injecting a small number of edges to the network in this project. To reach this goal, we have analyzed the current approaches in approximation algorithms in theoretical computer science, methods currently used in analyzing complex networks and heuristics that are based on network structure. Comparing the advantages and... 

In recent years, sparse representation has had a variety of applications in computer vision such as noise reduction, image reconstruction, classification and dimension reduction. In this project, we aim to provide a method of matching the keypoints obtained from the Scale Invariant feature Transform (SIFT) algorithm. In this algorithm is used descriptor instead of intensity . The proposed method, first, extracts the salient points from the images and learns a dictionary-based descriptors corresponding to the points. Then, using the dictionary, it obtains the sparse coefficients for each salient point by which, it determines the correspondence of the salient points in the two images using SVD... 

Making Decision about software architecture design is a multi-criteria problem which depends on different factors. One of the main problems in software architecture is the high cost and complexity of Decision making which is rooted in knowledge vaporiza-tion. In fact current developers of the system are not necessarily the primary designers of the architect. Thus, the system cannot be understood without the knowledge about the history of the architecture. Additionally, a good organization of knowledge will be helpful in terms of knowledge reuse and best practices which leads to low cost of architecture.Due to the importance of knowledge in software architecture, knowledge acquisition as well... 

Financing is an important barrier in growth path of small and medium-sized technology-based firms. Using guarantee letters to ease access of such firms to credit, is one way to encounter this barrier. In this study, the pioneer research and technology fund in offering this service to technology-based firms in Iran have been considered. Credit guarantee issuance records of this fund illustrates that none of credit guarantee letters certified by this fund has been defaulted yet. Comparison of fund’s credit scoring model with Chandler’s framework for organizational capabilities reveals that the fund does not investigate marketing and managerial capabilities in its credit scoring model. So, the... 

In this treatise, it will be shown that the subject of faith is the subject who loves God and in showing her love to God, she sacrifices her dearest things in the world. By doing that, she would free herself from everything that mind herself. She doesn’t do this action to be given a better reward by God. Her motivation for performing this action is nothing but love. Meanwhile, the subject of faith hopes God to respond to her love and engage in an I-Thou relationship with her. Now, her hope would be justified when God plays an active role in the world and admires her action, i.e., when eros can be attributed to God  

Let G be a simple graph. An eigenvalue of G, is a main eigenvalue if the corresponding eigenspace has a non-orthogonal eigenvector to the all-one vector j. A signed graph is a graph with a sign to each edge. If in the adjacency matrix of background graph change elements that corresponded by -1, set -1 and in the other elements don’t make any change, then we reach the sign matrix of a signed graph. By an eigenvalue of a signed graph, we mean an eigenvalue of its sign matrix. In this research, we study main eigenvalues of graphs and signed graphs. At first, we present the necessary and sufficient conditions for any graph which has exactly m main eigenvalues. Then, by introducing and creating... 

Nowadays, thin film alloy deposition has much importance. These alloys are used for various opto-electronic device applications such as liquid crystal displays, flat panel displays, plasma displays, solar cells and computer memories. Exact control of elements ratio in alloy is one of the important issues in deposition of thin film alloys. In alloy deposition with electron beam gun method from its elements, uniformity improvement of each layer is a way to maintain elements ratio in different parts of sample. This uniformity has much importance especially in optical coatings such as high quality antireflection coatings, highly selective filters and low loss reflectance coatings. In this... 

In this thesis, the orbit determination of Low Earth Orbits (LEO) using the integrated magnetometer and horizon sensor data has been investigated. Orbit determination is an essential part of a space mission. Not only the modeling, guidance, navigation and control errors may results in error in injecting the satellite into its nominal orbit, the environmental disturbances deviate the satellite from its predicted orbit and from an operational perspective most satellites need continuous orbit determination. Traditionally, ground based orbit determination is used which are non-autonomous and expensive and just can be used for specific times which the satellite can be observed from the ground... 

In this paper, we studied a two-echelon inventory system which consists of one central warehouse and one retailer. All installations follow base stock inventory management policy. The customers arrive at retailer according to Poisson distribution. The demand is satisfied when both central warehouse and retailer have positive on-hand inventory. Otherwise, the demand is lost. The lead time of central warehouse and the time needed to replenish orders of retailer are assumed to be exponentially distributed. The purpose of this study is to minimize the expected long-run total cost of the system per unit time. Total cost of the system includes holding costs of central warehouse and retailer, cost... 

Fault occurrence is an inevitable problem in industrial plants. These faults have numerous types. Some common kinds of faults are faults in actuators, faults in system dynamics, and faults in sensors. In many cases it is not possible to change or repair the broken part immediately. On the other hand, it is not reasonable to shut-down the whole system due to a minor failure. Therefore we should take a measure to have the best output possible in a faulty plant. In this thesis we have proposed a new static compensator by which we distribute the contribution of the faulty actuator among the other ones. At the end we evaluate the method by means of simulations  

Although a lot of research has been done on Carbon-based interconnect, there are many important questions unanswered. For example, there is no compact model for the resistance of bundle of CNTs at high frequencies, at which interconnects will be operating due to the scaling. Also there are many studies comparing CNT, GNR, and Cu wires but there is no study to show how much this will impact the design of a chip at today’s Giga Scale Integration. This comprehensive study should include chip performance, power dissipation and total number of metal levels. These two big questions are investigated in this dissertation. In the first part, high frequency behavior of CNT bundles is studied. A... 

Software Product Line Engineering (PLE) and Agile Software Development are two leading approaches in the software industry. Despite the inherent differences between the two approaches, they are intended to fulfill common goals, such as: Reducing time to market, increasing customer satisfaction, promoting product quality, managing changes in requirements, and lowering the costs of development. In addition, each of them has certain positive features which address the other’s weaknesses. As a result, it seems reasonable to integrate the two approaches in order to produce a combined method which fulfills the common goals while addressing the weaknesses. Agile Product Line Engineering (APLE) is a... 

In a centralized power system, the system operator, derives a maintenance scheduling plan that maximizing reliability of system and minimizing operating cost. But in a restructured power system the goals of GENCOs and independent system operator (ISO) are separate and each of them optimize its own goal. The goal of each GENCO is to maximize its annual benefits and the goal of ISO is to maximize the reliability of system throughout the year. Therefore there are two objective functions for finding an optimum maintenance schedule in restructured power system. This thesis proposes a new method for maintenance scheduling of generation units in a restructured power system. Firstly each GENCO...