Research ArticleOpen accessIn the abstractTunability Performance of Reflectarrays Based on Non-Linear Material PropertiesM. Y. Ismail, M. Hashim DahriLimited phase range and narrower bandwidth are the main performance limitations of reflectarray antennas for high gain applications which result in the performance to be restricted particularly in satellite and earth observatory systems. This study provides a thorough investigation on the tunability performance of reflectarrays designed in X-band frequency range using different non-linear dielectric substrates. An investigation of phase agility … …American Journal of Engineering and Applied Sciences, Vol. 6, Issue 1 · 6 Feb 2013 · 7,450 accessesView PDFCite
Research ArticleOpen accessIn the abstractComputational Techniques for Stability Analysis of a Class of Dynamic Economic ModelsGeorge E. Halkos, Kyriaki D. TsilikaModern microeconomics and macroeconomics study dynamic phenomena. Dynamics could predict future states of an economy based on its structural characteristics. Dynamic models in discrete time discrete state economic systems may take the form of one single linear difference equation or a system of linear difference equations. In this study we use Xcas and Mathematica as software tools in order to … …American Journal of Applied Sciences, Vol. 9, Issue 12 · 12 Dec 2012 · 7,379 accessesView PDFCite
Research ArticleOpen accessIn the abstractTime-Delay Estimation using the Characteristic Roots of Delay Differential EquationsSun Yi, Wonchang Choi, Taher Abu-LebdehProblem statement: For ordinary dynamic systems (i.e., non-delayed), various methods such as linear least-squares, gradient-weighted least-squares, Kalman filtering and other robust techniques have been widely used in signal processing, robotics, civil engineering. On the other hand, time-delay estimation of systems with unknown time-delay is still a challenging problem due to difficulty in formulation caused. Approach: The presented method makes use … …American Journal of Applied Sciences, Vol. 9, Issue 6 · 7 Apr 2012 · 8,082 accessesView PDFCite
Research ArticleOpen accessIn the abstractSynthesis of Robust Dynamic Controller, Model Predictive Control BasedMohamed Adel Sellami, Elyes Maherzi, Mongi BesbesProblem statement: More advanced control techniques have been developed in recent decades following the great progress of calculations means. Without considering the constraints on system variables, the response of controlled system moves away from the desired response. Hence the control strategy must provide the ability to integrate these constraints in the design phase of the controller. Approach: This study presents … …American Journal of Applied Sciences, Vol. 9, Issue 6 · 16 Mar 2012 · 7,267 accessesView PDFCite
Research ArticleOpen accessIn the abstractReengineering Legacy to Modern System with One Time Checker for Information System EvolutionP. Sudhakar, P. SakthivelProblem statement: The prime focus of Information System (IS) evolution process is the aggrandize productivity and quality of various components of the system. The evolution process is always challenging as it leads to an increase in overall complexity especially when the system changes are mostly confined to part of it. Approach: In this respect to improve efficiency and decrease complexity, … …American Journal of Applied Sciences, Vol. 9, Issue 6 · 14 Mar 2012 · 7,268 accessesView PDFCite
Research ArticleOpen accessIn the abstractSTATCOM Stabilizer based on Fuzzy Logic Control for Damping Power OscillationPrechanon KumkratugProblem statement: In power systems, there exists a continuous challenge to improve dynamic performance of power system. Approach: Static Synchronous Compensator (STATCOM) is a power electronic based device that has the capability of controlling the power flow through a line. This study applies the Static Synchronous Compensator (STATCOM) to control the power flow during dynamic period. To verify the effect … …American Journal of Applied Sciences, Vol. 8, Issue 10 · 8 Sep 2011 · 7,440 accessesView PDFCite
Research ArticleOpen accessIn the abstractInter-Area Power Systems Stability Improvement by Static Synchronous Series CompensatorPrechanon KumkratugProblem statement: The inter-area power systems have special characteristic of the stability behavior. The improvement of inter-area power system is one of the important aspects in power system. Approach: This study applies the Static Synchronous Series Compensator (SSSC) to improve stability of inter-area systems. The SSSC is modeled and then is applied to be incorporated into the power system model … …American Journal of Applied Sciences, Vol. 8, Issue 7 · 24 Jun 2011 · 7,006 accessesView PDFCite
Research ArticleOpen accessIn the abstractDynamic Allocation of CPUs in Multicore Processor for Performance Improvement in Network Security ApplicationsSudhakar Gummadi, Radhakrishnan ShanmugasundaramProblem statement: Multicore and multithreaded CPUs have become the new approach for increase in the performance of the processor based systems. Numerous applications benefit from use of multiple cores. Increasing performance of the system by increasing the number of CPUs of the multicore processor for a given application warrants detailed experimentation. In this study, the results of the experimentation done … …Journal of Computer Science, Vol. 7, Issue 6 · 14 Jun 2011 · 6,844 accessesView PDFCite
Research ArticleOpen accessIn the abstractOptimal Control Design of Static Synchronous Series Compensator for Damping Power System OscillationPrechanon KumkratugProblem statement: In power systems, there exists a continuous challenge to improve dynamic performance of power system. Approach: The Static Synchronous Series Compensator (SSSC) is a power electronic based device that has capability of controlling the power flow through the line both in steady state and dynamic sate. This study applied the SSSC to damp power system oscillation. The optimal … …Journal of Computer Science, Vol. 7, Issue 6 · 14 Jun 2011 · 6,885 accessesView PDFCite
Research ArticleOpen accessIn the abstractSynchronization of Chaos Systems Using Fuzzy LogicMohammad Ababneh, Issa Etier, Mahmoud Smadi, Jasim GhaebProblem statement: This study presented a new and systematic method to robustly synchronize uncertain chaos systems. It was derived based on the observer approach for synchronization, where error dynamics was made asymptotically stable around the zero to accomplish synchronization. Approach: This method viewed the synchronization problem as a control problem in order to make use of the literature available in … …Journal of Computer Science, Vol. 7, Issue 2 · 25 Feb 2011 · 7,642 accessesView PDFCite