Sharif Digital Repository

One of the best methods of gait analysis is to use analytical models. In this project, first, the normal human gait was simulated using a two-dimensional biped model with 7 segments, i.e., a HAT segment representing head, arms and trunk, and 6 segments representing thighs, shanks and feet of the two legs. The foot-ground contact was simulated using a five-point penetration contact model. The elastic impact and friction effects are considered in the ground reaction force modeling. Optimization of the normal human walking model provided constant coefficients for simple PD controllers’ (driving torque) equations that could reasonably reproduce the normal kinematical pattern. Then, in the second... 

Due to the importance of the direct reduction method in iron and steel production, the optimum operating condition of this unit has an increasing importance. In some areas, because of the climate conditions and geographical situation and inaccessibility to adequate water, supply of required water for the unit is a major problem. So, many attempts have been performed to decrease water consumption in these units. In this thesis, water consumption of the scrubbers in direct reduction unit of Mobarakeh Steel plant is investigated. First, this unit is simulated. Then with solving the set of equations of mass and heat balances of water circulation, the amount of water consumption in these... 

Considering the existing facilities and conditions, this study has been done to achieve the optimum of Hydrogen distribution in a refinery network. Tehran Refinery is the case study. First of all, 7 units of north part of Tehran Refinery have been simulated. These units are Hydrogen consumers, producers, and the units which are connected to them. The kinetic of Hydrogen production and consumption reactions and other processes are considered in simulation. The optimization problem solved by Genetic Algorithm method using relations of changes in processes and system constraints as linear and nonlinear equalities and inequalities. Developing the superstructure then reducing it by heuristic... 

The problem of LQR design based on full state feedback is solved completely in the subject of Optimal Control. So far, however, despite the fact that use of output feedback in many applications of Control is desirable or even necessary, designing optimal controllers using output feedback in general does not seem to have received much attention in the existing literature. Of course, special cases of designing simple controllers using analytical or numerical-analytical methods do exist in the literature. A new algorithm for tuning an optimal controller (P, PI, PID, etc) for a low-order system without delay, and also in the presence of delay, has been introduced in this thesis using the LQR... 

Todays, the most important thing in the oil and gas fields is how to find the main properteis as porosity and permeability; therefere in this project was tryed to estimate to correct porosity in the reservoir area with using estimated porosity from siesmic attributes. For this study Mishrif reservoir in Sarvak formation was selected and the used data are 3D siesmic and also corrected porosity estimated by analysing siesmic attributes from five wells. For combination sresmic and log data, Simulated Annealing was seleted as a Neural Network optimizer for this project.
 

Nowadays, the use of gas turbines with low capacity have acceptance in large quantity. This type of gas turbines with a capacity of approximately 5-200kW are known as microturbines. This type of turbines due to the existence of limitations on increasing of turbine inlet temperature and compressor pressure ratio has low efficiency compared to the turbine with high capacity. Therefore the use of a recuperator in the cycle is necessary. Optimum design of heat recuperator has important effect on improving of gas turbine cycle efficiency. In this project for optimum design of heat recuperator, the effect of recuperator on gas turbine cycle efficiency is studied. By determining geometric... 

Management decisions, Enhanced Oil Recovery, and reservoir development plans in petroleum industries are based on predictions by reservoir simulation. Due to uncertainties in model parameters or engineering assumptions, the simulation results are not accurate, while they are correct. One remedy is to match simulation results with engineering measurements, typically pressure and flow rate, by adjusting model parameters. In Reservoir Engineering literature, this is called History Matching and is an optimization problem. Common methods of history matching are based on finite difference simulation, and therefore have a very low speed. In addition, these methods usually ignore Geostatistical... 

Rapid growing use of energy resources in recent decades, caused to focus on combined heat and power generation systems according to their high efficiencies. Energy efficiencies with these technologies will be up to 90 percent. Some benefits of Co-generation systems are their high efficiencies, omitting of transmission and distribution lossesin the electricity grid, fuel consumption reduction, moving to ward privatization,independent and decentralized production of electricity and heat, increase competition in the power generation and reduction theemission of greenhouse gases, particularly carbon dioxide. In This article theeconomicsof combined heat and power generator stobe installed... 

Advances in semiconductor manufacturing technologies have enabled us to build billions of transistors on a single die. However, the increasing amount of process variation in nanometer technologies has made it inevitable to move toward statistical analysis methods, instead of deterministic worst-case-based techniques, at all design levels. In this project, we studied the problem of variation-aware task scheduling for MPSoCs. To this end, we first proposed a variability analysis framework to analyze the effect of process variation on the main parameters of MPSoCs. Then, to solve the MPSoC task scheduling problem, we proposed two metaheuristic variation-aware task scheduling method based on... 

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 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... 

The presence of highly toxic cyanides in the effluent of coke oven of steel industries is considered as a critical problem. Owing to high levels of toxicity, control and removal of cyanide are of great importance in this industry. Biological removal of cyanides by indigenous microorganisms offers inexpensive, safe and environmentally compatible option in comparison with chemical and physical methods. The present study primarily focused on the isolation and purification of the microorganisms which utilize cyanide as the sole source of Nitrogen in alkaline conditions. The isolated bacterial strains were investigated through variety of bacteriological and biochemical reactions as well as... 

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... 

Manufacturing environments has changed in recent decades. Today’s it has specification such as shorten life cycle of products, decrease new product design and manufacturing cycle, increase flexibility, decrease response time for market demands and increase competitive level among manufacturers. For achieve this specification integration of CAD, CAPP and CAM is essential. Process planning is important in manufacturing systems so that down stream activity costs and optimality depends on process plans. To develop a process plan for a prismatic part it is required to interpret part design data; select manufacturing processes; select machines, tools and fixtures; decompose the material volume to... 

One of the methods to enhance the economic performance and safety factor of nuclear power plants is to determine a suitable fuel loading strategy in a reactor core. Different methods have been already elaborated to choose the proper fuel loading pattern. Selection of the best pattern for fuel loading ensures the best use of fissile material and more safety during reactor operation. Perturbation theory method is one the methods which could be used to solve this kind of problems. The effect of non-uniform perturbations on the reactor operation can be evaluated by multigroup calculations and using proper space dependent group constants. In this study, a C# based program is developed to find the... 

In recent decades, emission from automobiles is considered one of the main reasons for global warming. One of the ways to decrease the fuel consumption of the vehicle, increase the power train efficiency and vehicle acceleration is to use Continuously Variable Transmission (CVT) and infinitely variable transmission (IVT). Previous inquiries include investigate miscellaneous types of continuously variable transmissions and their efficiency and different ways of combination of CVT and other power trains in order to create an IVT. The aim of this research is to optimize one kind of IVT transmission. At first, different state of combination of IVT portions will be investigated. Then, a model is... 

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...