Sharif Digital Repository

Nowadays Aeroelasticity is one of most important branch of aerospace science. The Aeroelastic analysis and get on aeroelastic safety margin, is one of the major steps that must be taken in flying crafts design. Diverse software have been developed for this purpose. Due to the increasing the demands of use of composite materials in aircraft structures, need to examine the effect of various parameters such as angles and stacking sequence on the aeroelastic instability (flutter and divergence) composite aircraft structures is determined. The analysis of wind turbines as a means of extracting energy from the wind and having a large diameter blades, causing the interference effects of aerodynamic... 

In order to survive in today's business world, which is changing at a very fast pace, organizations can detect deviations even before they occur, quickly and with a high percentage of confidence, by analyzing their processes, in order to prevent disruptions in the processes. by monitoring the information systems that automatically execute business processes, it is possible to ensure the correct implementation of the existing processes. For this purpose, various techniques for monitoring business processes have been presented so that managers have a comprehensive and real view of how implement processes and be able to identify possible deviations in the future and try to fix them because the... 

Video Instance Segmentation is one of the newest tasks in computer vision, tasked with segmenting, categorizing, and tracking instances across video frames. This task is highly significant and applicable today in industries such as autonomous vehicles, surveillance systems, production lines, and medical video analysis. Generally, there are two approaches for solving the task of Video Instance Segmentation: the object-oriented approach and the pixel-oriented approach. In the object-oriented approach, after detecting instances at the image level, the segmentation and tracking processes are performed to link the instances. In the pixel-oriented approach, all spatial-temporal information is... 

Introduction: Today, backward and forward scattering tomography of dispersive medium is of great interest because of its broad applications, especially in medical imaging, of breast cancer, Distinguishing different tissues of the body from each other is one of the necessities. Increasing the quality of the image by just a few percents has great improvement on the tomography resolution.
Materials and Methods: In this project we made phantom of the tissue and tumor from Intralipid 10% plus Agarose and Indian ink for soft tissue and plastic fibers as tumor having birefringence factor of 0.001.After putting the plastic tumor in soft tissue phantom, the polarized white light and a digital... 

Investigation of electrohydrodynamic behavior of fluids under electric fields is a challenging and impressive matter in condensed matter physics. In this thesis, inspired from previous works on liquid film motor, a new phenomenon has been observed and its properties has been investigated.Here by making a new device named “Liquid Film Electric Generator” we produced potential difference on the rotating suspended liquid film under electric field. The power conducted by electrodes has been generated on the surfaces of the film. By this method, under electric field of 1000 V/cm, micro-watt electric power can be achieved on a liquid film of diameter of about 1 cm.We explained this phenomenon on... 

In the past few years, virtual advertisement replacement has become one of the most popular methods of advertising. Currently a few companies are applying this novel technique on highly-viewd soccer videos. In the atmosphere of rivalry for achieving a method of cheapest and least needed-equpiment between companies, this thesis is aimed at introducing an all software system based on multi-view soccer videos. The goal is to bring the best possible qualities given the challenges of this particular definition. This thesis provides a system to replace advertisement boards around soccer field which consists of detection, tracking and adjusting the advertisement. In detection the systems aligns the... 

This work is concerned with a class of plate equations with memory and p-laplacian operator with simply supported boundary condition, where Ω is a bounded domain
of RN; g > 0 is a memory kernel that decays exponentially and f(u) is a nonlinear perturbation. This kind of problem without the memory term models elastoplastic flows  

Vehicular ad hoc networks (VANETs) are currently attracting the attention of researchers around the world. They offer a wide range of applications improving road safety and driving comfort. Since VANET applications affect safety-of-life, data security in a vehicular system is mandatory. VANET is a special case of Mobile Ad hoc Network (MANET). Routing in VANET is a controversial issue. Furthermore, Security at routing level is so important because if the routing is compromised, other protocol layers on top of the network layer are also compromised. In this thesis, DSDV, DSR and AODV routing protocols are simulated to understand which of these protocols are suitable for VANET. Finding... 

Many airlines operate different fleets under different service conditions. These aircraft fleets need to be maintained in service. Safety, reliability and economic reasons motivate manufacturers, airlines and airworthiness authorities to investigate about different approaches to aircraft maintenance. At first, corrective maintenance which was developed for other industries was used by the aircraft industry but due to increasing complexity of aircrafts and their systems the industry started using time based maintenance. After years of operation and fleet experience, this industry started developing a program of its own i.e., MSG-1, MSG-2 and MSG-3. These maintenance programs have been evolved... 

Hydrocracking is one of the most versatile petroleum refining process for production of valuable products including gasoline, gas oil, and kerosene. Various kinetic models have been proposed for hydrocracking process. A commonly used approach is to consider the mixture in terms of selected lums, which can be specified in terms of structural characteristics, such as boiling point. From this approach the reaction mixture can be considered in two types of discrete lumping and continuous lumping. In this thesis, a 5 parameter continuous kinetic lumping model was studied for modeling of the Isomax reactor of Tabriz refinery whose feedstock is a low quality gasoil from vaccum distillatin column.... 

In this research, the first attempt was made to increase the thickness of the absorbent layer and increase the size of the absorbent layer crystals and minimize the cavities of this layer. this attempt resulted in the synthesis of absorbent layer with a thickness of about one micrometer and with low cavities. then, an attempt was made to crystallize the buffer layer and form the bond with the absorbent layer. these efforts led to the synthesis of a cadmium sulfide layer with a high carrier density. in this study, cadmium sulfide and cadmium zinc sulfide and indium sulfide were used to make the cell. then we could synthesizing window layer with low resistance.at end, we made superstrate... 

In the proton exchange membrane fuel cells (PEM, the produced water would be divided into two phases of vapor and liquid. distribution of both liquid and vapor phases in different cell layers affects the performance, the efficiency and the life of a fuel cell significantly. Moreover, Nano pores of the cathode catalyst layer are involved with some phenomena such as electrochemical reaction kinetics, heat and mass transfer and interface phase change. One of the most important problems in the performance of fuel cells is distribution of liquid water in the porous areas. Water flooding in fuel cells causes to delay in oxygen transport to active sites in the catalyst layer because the pores of...