Sharif Digital Repository

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... 

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... 

The rapid expansion of the Internet of Medical Things (IoMT) and the massive generation of multimodal health data have provided unprecedented opportunities for early disease diagnosis and smart patient monitoring. However, the effective utilization of these data faces fundamental challenges regarding privacy preservation and severe computational resource constraints on edge devices. The distributed approach of Federated Learning (FL) addresses privacy concerns by training models locally without transferring raw data. Nevertheless, its implementation in real-world environments suffers from performance degradation due to device heterogeneity (the straggler effect) and their inability to run... 

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... 

Smart heat-sensitive polymers play a unique role in drug delivery systems due to reversible behavior in response to environmental changes, especially temperature changes. Among the heat-sensitive polymers, UCST polymers due to their specific behavior and very little-known polymers with this feature are the subject of many new researches. In the present study, New designed temperature-sensitive polymers with UCST capability based on acrylamide and vinyl acetate were synthesized. These copolymers were synthesized in different percentages of acrylamide by free radical polymerization in solution conditions. All polymers compounds were characterized by H-NMR, FT-IR, DSC and GPC measurements. The... 

There are several methods for measuring thin film thickness, however, for the analysis of liquid film motors [1] we need a method which is capable of measuring the thickness using a single image of the film. In this work, we use the colors that appear on thin films, such as soup bubbles, which is a result of light interference to calculate the thickness of the layer  

Thermal relaxation time is the time when maximum temperature of a particle get to 1/e of it’s initial value. The destruction of a tissue depends to this important parameter. This parameter has studied by Monte Carlo simulation of pulsed laser in to environment as healthy and cancerous tissue. The main goal of this method is providing proper temperature in a special area so that minimize thermal destruction around that area. In this thesis, temperature distribution of tissue that is caused by pulsed laser, has solved by new method;in this new method the pulse duration uses for Monte Carlo simulation. Also using the solution of radiation transfer equation by Discretes Ordinate Method, new... 

By direct and alternating electric field applied to thin film of liquid suspended in the air we can spin out and control it. Rotation pattern depends on the geometry of the electrodes and the applied magnetic field. This is called a rotating liquid film (Liquid Film Motor). To determine the cause of rotation, different models have been proposed. In this project we have tried to check the accuracy of any of the models. Using particle velocimetry using the photo, we calculate the velocity pattern. Then, using the Navier-Stokes equation calculate the acceleration and viscosity from the velocity. Then, for a special arrangement using a finite diffrent method, electric potential and the electric...