Sharif Digital Repository

New electric Unmanned Aerial Vehicles (UAV) has unconventional methods for design and performance analyzing. Using the electric power sources and reduce power with time, cause to confusion about operating this type of planes, so new optimization methods are generated. This methods, can used for some part of flight and special problems and involve some assumptions. One of these new methods is using Singular Perturbation theory for prediction optimal path trajectory of Aerial Vehicles. In this research, we solve the optimal climb trajectory for an electric UAV in rested (no wind) atmosphere. Solution of this problem, involve some parameters such as velocity, altitude and flight path angle with... 

The main purpose of this dissertation is to study thermoelastic behaviors in rotating disks subjected to thermal shock loads based on the generalized and classic theories of coupled thermoelasticity. To this end, this research has been carried out in two stages. In the first stage, thermoelasticity problems in an axisymmetric rotating disk with constant thickness made of a homogeneous isotropic material are analytically solved. In this stage, based on the classical and generalized coupled theories, and dynamic and quasi-static uncoupled theories, an analytical method based on the Fourier-Bessel transform is employed to obtain the thermoelastic solutions. Then, closed-form formulations are... 

Sea water desalination needs fossil fuel and electricity. Although there has been major technical development in this case , including RO technical improvements, mainly motivated by oil exporting rich countries, under developed region still need investments for these processes. In this MSc project , a process using renewable energies is investigated to minimize operating costs. “Green technologies” for water desalination will become attractive with oil price increase. The green desalination process is simulated and sensitivity analysis of parameters is investigated. Based on the results, the optimum number of effect is 6, last effect pressure equal to 0.64 bar, and the sea water flow rate to... 

In order to retrieve the temporal dynamics of the long term memory representation, which is believed that synaptically encoded with respect to an approach, we have utilized machine learning methods to classify the magnetoencephalogram (MEG) data that has been collected from an experiment called association task. The decoding process can be considered as a two-class classification problem in which we want to make a decision about the color or orientation of the grating of the test label. For the first step, different features have been extracted. This extraction can be done from the total signals of the different channels or can be extracted from the signal segments for each channel. These... 

Considering the drastical increasing of greenhouse gases in the atmosphere, especially carbon dioxide, reduction of these gases seems necessary to combat global warming. Fossil fuel power plants are one of the main sources of CO2 emission. In this thesis, CO2 capture from a natural gas fired combined cycle power plant using different oxygen percent in air feed is studied. Aspen Plus was used to evaluate the effect of this capture technology on the plant efficiency and energetic parameters of the system. Aspen Hysys is used to simulate Amine absorption tower and Air Separation cryogenic tower. Since the oxygen production plant, CO2 capture and transport are cost and energy intensive, the cost... 

In this thesis, three different mathematical models named Markov Reward Model (MRM), Stochastic Reward Net (SRN) and Stochastic Activity Network (SAN) are used to model and evaluate the performability of grid computing environments consisting of many grid resources. The proposed models consider the arriving and servicing process of grid tasks inside a resource together with the failure-repair behavior of processors of the resource. Since the proposed MRM cannot be extended to model a grid environment with some realistic assumptions, we switch to use SRNs in modeling a single grid resource with more number of processors. Although the proposed SRN models for a single grid resource can...