NASHRIYYAH -I MUHANDISI -I BARQ VA MUHANDISI -I KAMPYUTAR -I IRAN, A- MUHANDISI -I BARQ
Year:2012 | Volume:9 | Issue:4|Papers Count:7

In this paper, the long-term dynamics of an electricity market due to bounded rationality in investment decision is analyzed under different market designs, including energy only market (EO), market with operating reserve pricing (OR), market with fixed capacity payment (FCP) and demand curve-based capacity market (DC). System dynamics (SD) method is used to analyze the behavior. Also, the equilibrium path is determined for comparison purposes. The results indicate that the different market designs have very different dynamics and it is possible to mitigate power market dynamics by selecting proper market design.

Course timetabling is a complex problem, happening at the beginning of every semester at universities. One of the most important problems related to this issue is various constraints. As a result of this, timetabling is performed in various methods at different departments. Many works have been performed to solve this problem which majority of them have used metaheuristic based techniques. In this paper, an algorithm is based on hybridization of improved memetic algorithm and simulated annealing algorithm is proposed. Improvement in memetic algorithm means heuristic initializes population and modification in crossover operator. Also, an operator which is called improvement is designed for improvement of created chromosomes and decrease of violation of constraints. In addition, utilization of simulated annealing will result to increase of the exploitive search ability of memetic algorithm. The experimental results which based on standard data indicate this method is more efficient in comparison with some other new methods.

In This paper, a new scheme for long term learning in CBIR systems is proposed. In this scheme, semantic templates are extracted from information provided through relevance feedback process for short-term learning which use similarity refinement techniques. This information will be used as semantic templates in future retrieval sessions to improve the precision of the CBIR system. Also, a similarity function is introduced to calculate the similarity between queries and semantic templates. The proposed method is examined on a database with 10000 color images. The experimental results and comparison with ‘iFind’ method, confirm the effectiveness of the proposed method.

Object boundaries detection is one of the interesting subjects in computer and image processing. Active contour models are one of the popular methods in object detection and segmentation. This paper presents a new method for segmentation of texture object by means of parametric active contour. In this proposed method, by adding a balloon energy to energy function of the parametric active contour model, the detection and segmentation of textured object against textured background would be achieved. In this method, texture feature of contour and object points are calculated by contourlet transform. Then by comparing these features with texture feature of target object, which are available as prior information, movement direction of balloon is defined, whereupon contour curves are expanded or contracted in order to adapt to the target boundaries. Experimental results demonstrate that the active contour based on contourlet (Contourlet-ACM) has higher segmentation accuracy than the active contour based on moment (Moment-ACM) and active contour based on DWHT (DWHT-ACM).

An optimization method has been developed to determine the optimal capacities for the CHP and boiler such that thermal and electrical energy demands can be satisfied with high cost efficiency. The proposed method offers an operational strategy in order to determine the optimum value for boiler and CHP capacities which maximize an objective function based on the net present value (NPV). The reduction in operational strategy expenses arising from the monetary cost of the credit attainable by air pollution reduction is also taken into account in evaluation of the objective function. The optimal value for boiler and CHP capacities and the resulting projection for the optimal value of the objective function are derived using a hybrid optimization method involving the particle swarm optimization (PSO) and the linear programming algorithms. The viability of the proposed method is demonstrated by analyzing the decision to construct a CHP system for a typical hospital.

Thyristor Controlled Series Capacitor (TCSC) has been used for various purposes such as power system stability improving and increasing of loadability, loss reduction, line impedance compensation or power flow control. Fast switching of TCSC from capacitive mode to inductive mode and vice versa following the fault and clearing of it respectively, is an essential key for improving transient and even dynamic stability of power system which have not been considered significantly.In this paper a new algorithm for fast mode-switching and control of TCSC in less than half cycle is proposed for changing capacitive to inductive mode and vice versa in less than half cycle. Simulation results show that the proposed method is faster and more reliable in different conditions than the existing method and can be used more effective in transient and dynamic stability improvement.