Sharif Digital Repository

Today, with the increasing use of non-linear loads in the power grid, power quality problems such as current harmonics, unbalance and reactive power have intensified. It is common to use active power filters to solve these problems. In order to justify the use of active filter, two approaches can be adopted. On the one hand, by increasing the active filter capability such as simultaneous harmonic compensation, umbalance and reactive power by one device, the filter capabilities increased. On the other hand, it reduced the final cost of the active filter. In this research, firstly, a comprehensive hardware structure for various compensation applications is presented. This is done with the aim... 

Usually the structures are designed based on the fixed-base assumption; however thisassumption is not always correct and the bed flexibility should be considered. This effectwhich is called soil-structure interaction, change the response of structure on both elasticand inelastic behavior. In the regulations for the design of structures on flexible base,generally soil-structure system is replaced with an equivalent fixed base structure; in theway that the design force of soil-structure system with reasonable accuracy can beestimated by equivalent fixed-base structure. In some regulations, dynamic characteristicsof equivalent structure have been determined on elastic state and the results have... 

This work presents a quick method in estimation of spring back effect in sheet metal forming. In this method, the so called Inverse Finite Element Method (IFEM) has been adopted for compution of strains and also blank shape. Although the of element used is membrane, the effect of bending/ unbendiing is considered by addition of some extra forces as the bending forces to the nodal forces. The results of strain distribution obtained by IFEM are applied to another algorithm developed for computation of the spring back . this algorithm has been developed for the sections with plane starin assumption. Therefore, spring back of longitudinal parts, can be estimated by this method in a short time.... 

Analog computing has emerged as a promising candidate for Neural networks' implementation due to its high Interconnectivity, high bandwidth, parallel computing, high-speed processing, and low power consumption. Artificial Neural Networks have a wide range of applications; however, the Implementation of complicated Neural Networks on traditional computers would encounter two fundamental obstacles: limited processing speed and non-optimal energy consumption. This thesis's primary focus is on designing and simulating a whole-passive planar Optical neural network(ONN) based on silicon photonics technology. Firstly, the concept of ONN is studied using some lately proposed work. The device is... 

In the regard of structural health monitoring the identification of the structural modal parameters is essential. Since the different sources (wind, waves, Devices …) induce vibration on an offshore platform, it is impossible to determine the portion of each source in vibration. Thus the methods that analyze vibrations needless of input measurements are more efficient. These methods apply the ambient factors and obtain the modal properties from the structural response. This procedure has no unwanted effect on the serviceability of structure and by placement of sensors on the platform; one can monitor the structural health.
In the present work a two dimensional jacket offshore platform... 

In economics, choice or behavior is considered as a result of utility optimization. However, there’s much theoretical and experimental evidence that shows human beings suffer from decision-making and judgment errors. This research aiming at examining the relationship between post-choice attitude changes and framing effects as the two instances of those errors designed and implemented a 2 by 2 between-subject lab experiment. The subjects were randomly assigned to one of these four groups. The two treatment groups made their decision after they rated the objects one time and the two control groups did this after they evaluated the objects two times. Another intervention was to manipulate...