Sharif Digital Repository

Nowadays, due to environmental problems, electric cars are becoming more and more popular. The main drawback of these cars is due to the large volume, weight, and price of the battery and its long charging time. Charging the battery at short intervals or even in moving, can help to use a smaller battery and reduce battery problems. Therefore, the dynamic wireless power transmission technology that provides power without having to stop the car to recharge its batteries can revolutionize the electric car industry. The ever-expanding advance of power electronics and wireless power transmission technologies has made it possible to transfer power to moving electric cars. Barriers to this industry... 

In this research, we have presented a method to delay the propagation of fault current in high voltage power supplies. Common protection methods usually protect the load and do not protect the power supply itself well. In this research, our goal was to propose a method to prevent the short circuit fault current from reaching the power supply elements. At first, the available methods to limit the fault current and protect the high voltage power sources were studied and investigated. Then, using the transmission line theory, a ladder filter was designed as an alternative to the normal filter at the output of the power supply. In the next step, using software simulation, the performance of the... 

A Tesla charged PFL Bipolar pulsed power generator has been successfully designed and simulated. The compact Tesla transformer that it employs has successfully charged capacitive loads to peak voltages up to 0.6 MV . The Tesla–driven PFL generator is capable of producing a voltage impulse approaching .3 MV with generating a peak electrical power of up to 1.8 GW for 5 ns when connected to a matched resistive load. Potentially for medical application, a bipolar former has been designed and successfully simulated as an extension to the system and to enable the generation of a sinusoid-like voltage impulse with a peak-to-peak value reaching 600 kV and having a frequency bandwidth beyond 1 GHz.... 

With the expansion of the use of electric energy, the importance of sustainable supply of this energy has been revealed. The task of supplying this energy is with power systems, therefore, for a stable supply of electrical energy, it is necessary to continuously monitor the systems. Power systems are composed of various destructible components such as cables. There are various methods and tests for maintaining and monitoring power cables. One of the daily maintenance methods of alternating current cables is called very low frequency testing. The main advantage of this test is the small and portable nature of the test equipment. In this thesis, the design of a very low frequency alternating... 

One of the ways to enhance the safety and economic performance of nuclear power plants, is to choose an appropriate policy for arrange the reactor fuel assembly in the beginning of each cycle. There are variety of ways to optimize the layout of the fuel in the reactor core, but to achieve more than one goal, choosing multi-objective method can be used.One of the intelligent optimization methods is the genetic algorithms that emulate nature of biological processes and can be used to optimize two or more of the target.The goals of this research is to increase the neutron multiplication factor is to make maximum use of the fuel in the reactor and maintain the radial power peaking factor for... 

Flameless combustion in combustion technology is an innovative method with low nox production that few years provided it passes. In this paper the effects of various parameters on flameless combustion chamber with separate fuel and air jets, has been modeled numerically with the help of Fluent 6.3 software. Differences between traditional combustion and flameless combustion were determined and the flame structure has been studied in different scenarios. In numerical modeling, approach were used to modeling turbulence and eddy dissipation concept (EDC) approach use to modeling combustion and turbulence interaction effects. A global Two-step reaction mechanism for propane and a global... 

Gene regulatory modeling in different species is one of the main aims of Bioinformatics. Regarding the limitations of the data available and the perspectives which should be taken into account for modeling such networks, proposed methods up to now have not yet been successful in yielding a comprehensive model. In one of the recent researches, the Gene regulation process is considered as a nonlinear dynamic stochastic process and described by state space equations. Afterwards, in order for the unknown parameters to be estimated, Extended Kalman Filtering is used. In this thesis, first of all, Gene complexes are taken into consideration instead of genes and afterwards, Extended Kalman... 

Parkinson's disease is a progressive and severe neurodegenerative disorder in the central nervous system that is common in adults and, to some extent, in young people. One way to control and improve this disease is through rehabilitation, specifically in the form of rehabilitation activities. Due to the difficulty of travelling to and from the clinic, systems have been developed today that, using inertial sensors, provide the possibility of remotely monitoring this type of treatment up to 95%. In this regard, a system named SEPANTA has been developed at the Djavad Mowafaghian Research Center to diagnose and monitor the rehabilitation activities performed by patients with Parkinson's disease.... 

In this study, temperature and Thermo-mechanical stress Distributions during and after TIG welding operations of AA2024 have been investigated by means of numerical simulation and experimental observations. Different geometries and initial microstructures, i.e. artificially and naturally aged alloys, have been selected. The model can determine the effect of welding parameters as well as mechanical fixtures on temperature and stress fields developed within metal being welded. Furthermore the subsequent aging behaviour of welded alloy (up to 70 days) has been evaluated employing hardness measurement and tensile testing. In addition, microstructural evolutions have been made utilising Scanning... 

Distal humerus fractures commonly take place in adults with low bone mineral density causing major technical challenges upon orthopedic surgeons. Persian fixation method was introduced as a novel technique to stabilize small fragments in comminuted distal humerus fractures using a set of K-wires and reconstruction plate. The objective of the present study is to measure the stiffness and stability of this technique and analyze the effect of influential parameters with numerical simulation and biomechanical testing on a cadaveric specimen. Furthermore, we were able to propose new method to model plastic deformation of implants in surgery.Validation of the finite element (FE) model was... 

According to increasing computer systems, needs for verification of such systems with respect to desirable properties is critical. Model checking is one of the best methods of verification. Different methods have been proposed for model checking. The most efficient of these methods is automata-theoretic approach. In this approach, formal specification of desirable property, specified by formula in temporal logics, is translated to corresponding automaton. If the system model is expressed as automaton, the problem of model checking is then reduced to a problem of automata-theory. The question is the following. Are all the computations of the corresponding automaton accepted by the automaton... 

Cloud computing is a paradigm for scalable processing infrastructure which combines distributed software concepts, networks and IT management. Virtualization techniques help to increase productivity from resources. Services are adjusted based on service level agreement with a contract between users and service providers for specifying quality service. In this way, the level of customer satisfaction will be improved. Reliable and flexible management of service level agreements is very important for users and providers. This agreement model is used to prevent the payment of the penalty by providers and minimized interaction between users and providers. Migration from the traditional model to a... 

Predicting the Amino Acids that have a catalytic effect in the enzymes, is a big step in appointing the activity of the enzymes and classifying them. This is a very challenging job, because an Amino Acid can appear in a variety of active sites.The biological activity of a protein usually depends on the existence of a small number of Amino Acids. Detecting these Amino Acids from the sequence of Amino Acids has many applications. Usually, the Amino Acids that are preserved are known as the Amino Acids that build up the active site, but the algorithms for finding the preserved Amino Acids are much more complex. There are a lot of algorithms for predicting the active sites of Amino Acids, but...