Sharif Digital Repository

As technology develops, the need of instruments which could be used for improving the rate and accuracy of the manufacturing increases. This makes the robots inevitable to use in most industries. Among the robots, cable-driven robots have special characteristics that increase the tendency of using them.Multi-body cable-driven robots are novel type of cable-driven robots that have advantages compared to single-body ones. Capability of use in rehabilitation applications, in which the different parts of human body have to move separately, is one of the advantages of multi-body cable-driven robots.The first aim of this thesis is to extend the tensionable workspace concept for multi-body... 

The development of the boundary layer and shock boundary layer interaction essentialy determine the performance boundaries of transonic aircrafts. Employing shock and boundary layer control has therefore a large potential for improving flight performance. Aerodynamic surfaces of these aircrafts usually have very closed design points and critical points so small changes in angle of attack and free stream mach number cause entering drag divergence. Adaptive wings are the aerodynamic surfaces that use additional devices to control the flow pattern for improvment of aerodynamic performance in different flight conditions. Shock Control Bump is a control mechanism that is used for shock wave... 

Ionization chamber is used in radiotherapy for to get precise information from amount activity of radionuclide. Ionization chamber filled with Argon is used to measure the activity of brachytherapy radionuclide. This device measures the activity according to the produced current by the incident radiation. In order to obtain the precise activity of the radionuclide, it is necessary to the precise amount of the device calibration factor which relates the amount of the produced current to the activity. Because of little access to standard radionuclide and for appointing the activity of unknown samples, ionization chamber calibration is done indirectly and with the help of the simulation of the... 

Performance-based seismic design method, with a new look and a totally different philosophy, as an alternative design method instead of strength-based design method has been suggested in the new generation of seismic codes. Massive problems such as the need for complex dynamic analysis and consequently, spending high cost and time in researches forced researchers to seek more effective methods to evaluate seismic performance of structures. This idea in the optimal design of structures that require repeated analysis seems to be more effective. In the Endurance Time (ET) method, structures are subjected to specially designed intensifying acceleration functions and their response at various... 

The present study was aimed at developing a model to optimize the sizing of wind turbines according to the region’s wind condition and the capital costs of each part of the turbine. The proposed model, which consists of technical aerodynamic, economic and optimization sub-models, is used to achieve maximum annual energy production by a fixed cost of a single or a number of wind turbines. A cost model has been used to determine the detailed cost of the turbine’s components. The model’s results are presented for two regions in Iran, Khaf and Ahar, and the optimized configurations for a single turbine and a wind farm have been investigated.A case study for the region- Manjil that has some... 

Biodiesel can be a good alternative for fossil diesel since it isrenewable, biodegradable and non-toxic. Also, in comparison with fossil fuels, it emits less air pollutants and greenhouse gases.Findacost effective and environmentally friendly wayforcontinuousproductionofbiodieselcanaddressmany of our environmental concerns. In this study, we applied heterogeneous alkali-catalyzed transesterification as method and used waste frying oil as a low cost feedstock for biodiesel production. The project was performed in two phases. First, experiments were conducted in astirred reactor to finda suitable catalyst which was strontium carbonate calcinated for 3:24 hours in 975̊C.
RPB(rotating... 

The aerial vehicle capable of vertical takeoff and landing (VTOL), have created an interest in the community of researchers and admirers of Unmanned Aerial Vehicles. Among the existing UAV's, those with the capability of vertical takeoff and landing are prominent due to their higher maneuverability and hover capability. Quadrotors mostly have been considered as a flying robot for save and rescue operations in dangerous and unreachable places in addition to its military application. In cross shape of Quadrotor platform on each edge is appointed an electric motor with light rotors that usually are controled by considering motor rates as their only inputs. This thesis aims, to simulate and... 

Retinal detachment is a disorder of the eye in which a part or entire retina detaches from underlying layers. It is a medical emergency and if it is not treated, all vision may be lost. Surgery is the only way to treat retinal detachment. Pneumatic retinopexy (PR) is an office-based procedure for repairing some retinal detachment. PR has three cardinal steps: applying laser or cryopexy around all breaks to seal them, injection of gas into the vitreous cavity and appropriate head position so that the bubble closes the retinal breaks.
In this thesis, we are trying to model PR procedure and predict the behavior of intraocular gas. In general, once the gas is injected into the eye, because... 

In recent decades, rapid growth in the utilization of energy resources has led to using a system of combined power, heating and cooling due to their high efficiency. Losses of electrical power transmission and distribution networks are also another reason to emphasize using the combined production systems. Today, the use of small scale combined production systems at the same time, competitive with electricity generated from renewable energy technologies have also emerged. The present study was undertaken to answer questions on the topic of disrict heating and cooling system design with power that can be occur. For this purpose, first the governing mathematical equations are expressed and... 

Structural vibrations can be reduced using an opposite force generated from an active controller. Nowadays implementation of smart materials for active controlling of vibration is growing increasingly specially in aircrafts, spacecrafts and other state of art manmade machines. In aerospace structures as the weight is extremely a limiting factor, the lightweight structural control strategies are more demanded. Considering these motivations, in recent decades, engineers have done many researches to implement active structural damping methods in industrials applications. Among all active vibration approaches, using piezoelectric materials is one of the most attractive ways because of their... 

This study addresses the simultaneous berth and quay crane (QC) scheduling problem in a container terminal. The berths are considered as a continuous area and the vessels arrive dynamically. QCs are allowed to move to other vessels before completing the process on an assigned vessel.The objective function is determined based on the practical applications of the problem. It deals with minimization of sum of the completion time of vessels. In this research, a mathematical model has been developed for the research problem. According to NP-hardness of the research problem, two meta heuristic algorithms based on Tabu Search are proposed. To solve the problem, these methods have two layers with... 

Structures which are designed in accordance with previously used design codes are usually weak to sustain dynamic loading and therefore they shall be rehabilitated. One approach for rehabilitation is to use active control. In this study, active tendon is used as a structural device control. Various arrangements of controllers can be used to limit the response of the structure but it is desired to find an arrangement at which the cost of the placement will be minimized. The aim of this thesis is to find the best placement of active tendons on a frame such that the placement satisfies two general restrictions; namely structural response and control forces. Genetic algorithm is applied to the... 

Some of the most usual problems in rehabilitation are ankle joint disabilities which are caused by stroke or damages like ankle twist and disrupt the movement activities. So rehabilitation of this joint which has important role in daily activities like walking is of high importance.
The aim of this research is design of an unwearable robot for rehabilitation of ankle. After the study of several different mechanisms, this robot was designed based on a 2 DOF mechanism named “Agile Eye”. Based on the mechanism and parametrical analysis, final design of this robot was drafted using optimization method. Next, the musculoskeletal model of lower limb was created in MATLAB and by using this... 

In recent decades, the air pollution issue and fuel resource constraints have compelled researchers to find ways to replace fossil fuels or reduce their consumption. Since the Vehicles are one of the most important sources of pollution and energy consumer, efforts to reduce vehicles fuel consumption can be an effective action to reduce air pollution. A proper powertrain system has an important task to reduce fuel consumption and air pollution.
Uses of continuously variable transmission system (CVT) and infinitely variable transmission (IVT), which makes the internal combustion engine to operate in optimal condition, can help to achieve this goal. In this thesis, the target is find... 

The purpose of this project is choosing optimal technologies of cooling and heating and production of usable hot water and also to use optimal thicknesses of heat isolating walls, roof, floor and heat isolating of hot water transfer piping that is done to minimize the expenses of technology, energy and maintenance of the technology. We did all of the above mentioned issues by depicting the energy balance. In this modeling, we first defined four scenarios. Then by using a linear mathematical model of integer, the optimum number of lamps selected in accordance with the standard lighting. In the next step, by using a nonlinear mathematical model, we defined the optimal thicknesses of insulators... 

This project focuses on the Tennessee East-man challange problem(TEP) and the impact of setpoint changes and controller tunning on plant performance and profitability. TE has four major units. it is an unstable system due to the reaction within the reactor and a recycle streamcausing snow ball effect. As a result the control of this system is not easy. The study has been conducted along two main directions. First, selecting the optimal values for the setpoints and applying them in the simulation. secondly, try to find better parameter for controller in simulation. Simulation is based on working of Ricker. In TEP like the other multivariable systems, it is ameanable to use a centralized... 

The only problem in aviation and airport development is the noise print on population groups surrounding airports due to its high frequency it is so annoying for human ear. In order to overcome this problem technology has reached its edge and the only alternative is to deviate terminal flight path.In this thesis I tried find a pattern for optimizing terminal flight path considering a Boeing 737-800 taking off from Mehrabad airport’s runway 29. To do this we were in need of a huge database of airplane low speed model, geographic information and population knowledge.The common approaches used by FAA and other international organizations for modeling low speed flight were used. The influence of... 

Xanthan is a water-soluble anionic polysaccharide that is produced by anaerobic fermentation using the bacterium Xanthomonas campstris. Xanthan is used in various industries, including food industry and oil industry because of its appropriate rheological properties. For this reason, various studies have been done on the production and recovery of xanthan. In this study conditions for recovery of xanthan gum were investigated and optimized by response surface methodology. Initially xanthan production under optimal conditions that determined in previous studies i.e. YM broth at 30 ⁰C without pH control was performed. After production, the gum separation was investigated using food solvents... 

In this study, aerodynamic shape optimization of axial compressors is considered. In order to optimization, one of the gradient based optimization algorithms, namely Adjoint method, is used. Recently, Adjoint method has been emerged as one of the reliable gradient based optimization algorithms in turbomahineries applications. Because this method is a gradient method of optimization, similar to the other entire gradient based algorithms, adjoint method also has a better convergence than non-gradient based optimization algorithms. In this work, aerodynamic shape optimization of two-dimensional cross section through a transonic axial compressor is studied. The process is considered for midspan... 

In this thesis we propose a new metamodel based simulation optimization algorithm using sequential design of experiments. The main objective is to have a new method which can be used without deep knowledge of different kinds of metamodels, optimization techniques and design of experiments. The method uses three metamodels simulataneously and gradually adapts to the best metamodel. In each iteration, some points are chosen as candidates for future simulation. These points are ranked based on the quality of metamodel prediction and their placement among simulated points, the best point will be chosen for simulation. Comparing the proposed algorithm with some of the popular simulation...