1 ): Association of Information & Communication Technology of Iran 642 Special Design, simulation and performance comparison of radating elements of reflect array antenna 1 4 2013 5 15 1 8 03 03 2015 03 03 2015 In this paper, the role of radiation elements in the performance of reflect array antenna is studied, and each element is designed and simulated and the phase response is compared. Also, the relations needed for designing reflect array antenna are discussed and one sample reflect array antenna is designed in the KU band and the results are presented.
643 Special Three-axis attitude control of a micro-satellite by magnetic actuators through-synthesis robust method 1 4 2013 5 15 9 18 03 03 2015 03 03 2015 In this paper a robust controller using µ-synthesis method has been designed for attitude control system of a micro-satellite in LEO orbit. Then the controller has been evaluated with accurate linear and nonlinear simulations. After necessary evaluation three-axis stabilization method with only magnetic torques and auxiliary gravity gradient boom was been selected. Nonlinear kinematics and dynamics equation of this system was obtained and linearization was performed on it. Finally the system was converted into a multivariable linear time varying system and controller for this system was performed via µ-synthesis, which has been done by changing from time varying system into system with uncertainty. 644 Special A Model for impacts of Investment in IT on customer satisfaction, using Structural Equation Modeling and Path Analysis 1 4 2013 5 15 19 30 03 03 2015 03 03 2015 In a research, that this paper reflects its results, a model for stating the relationship between investment in IT and customer satisfaction was developed. This study starts with extensive literature review on investment in IT and customer satisfaction. Then, a conceptual model with four criteria (including Economic, educational, diffusion of ICT and telecommunication) and one latent variable (indicator of customer satisfaction) were designed. This model’s primary validity was approved through expert opinion. Then, in a field study in the organization under study, the required data have been gathered for testing functional approval of the model. In the next stage of research, by using SEM techniques and interactive regression equation in the form of path analysis and using the software like SPSS and LISREL , we concentrated the factors of relationship between latent variable and observed variables. The finding of the research shows direct relationship between economic and educational factors of IT investment on customer satisfaction. 645 Special Increasing data throughput in HF channel by decision feedback equalizer employing MC-FQRD-RLS algorithm and weight extraction in data mode 1 4 2013 5 15 31 38 03 03 2015 03 03 2015 Increasing data throughput of Multipath time-varying HF channel by employing decision feedback equalization is addressed. In this paper, we propose multichannel FQRD-RLS adaptive filtering algorithm employing weight extraction in Decision-directed mode. A comparison between this technique and IQRD-RLS algorithm is performed. Simulation is conducted under channel parameters with respect to MIL-STD-188-110B. The results show higher data throughput in a frame with acceptable computational cost. It is also shown that the achieved data throughput is as same as using MC-FQRD-RLS algorithm in Full-Iteration equalization mode, at a much lower computational cost. 156 Special A Satellite Control Method Using Laguerre Model Predictive Control Approach jafari fesharaki shekoofeh m towhidkhah farzad n Talbei Heidar Ali o m amirkabir University n amirkabir University o amirkabir University 1 4 2013 5 15 39 48 21 10 2012 03 03 2015 In this paper a Model Predictive Method based controller is proposed to control a satellite. Model Predictive Control (MPC) has been well known as a practical control method for various systems in industry. A problem with this method is its computational effort and time consuming. To reduce computational load Laguerre functions have been proposed in this literature. Simulation results are given to show feasibility and the validity of the design. A comparison between the time consumed in the presence and the absence of the Laguerre functions is done too. 211 Special naghdehforoshha mona 1 4 2013 5 15 49 58 18 05 2013 03 03 2015