Research ArticleOpen accessIn the abstractImproving Mechanical Characteristics of Inverter-induction Motor Drive SystemHussein Sarhan, Rateb IssaAn inverter-three-phase squirrel-cage induction motor drive system with improved mechanical characteristics is presented. The proposed system provides mechanical characteristics with constant maximum torque or increased maximum torque and reduced slip speed at frequencies below the nominal frequency. The control algorithm is based on the constant volts per hertz principle using two improvement techniques: keeping maximum torque constant or keeping magnetic … …American Journal of Applied Sciences, Vol. 3, Issue 8 · 31 Aug 2006 · 7,661 accessesView PDFCite
Research ArticleOpen accessIn the abstractFault Detection of 3-Phase VSI using Wavelet-Fuzzy AlgorithmM. Rozailan Mamat, M. Rizon, M. S. KhannicheThe good knowledge and information about the fault mode behaviour of the PWM voltage source inverter is important to improve system design, protection and fault tolerant control. This paper develops a real-time condition-monitoring algorithm for 3-phase Pulse Width Modulation (PWM) inverter in fuzzy speed controlled induction machine. It is designed to detect and identify the transistor open-circuit fault and an … …American Journal of Applied Sciences, Vol. 3, Issue 1 · 31 Jan 2006 · 7,958 accessesView PDFCite
Research ArticleOpen accessIn the abstractA Laboratory Study of Bayesian Updating in Small Feedback-Based Decision ProblemsTakemi Fujikawa, Sobei H. OdaThis study explores small feedback-based decision problems experimentally. Conducted were the experiments in which the decision-maker’s payoff distribution was limited to either favorable distribution or unfavorable distribution. The first remarkable observation revealed complexity/loss aversion in the experiment. The second observation included the law of small numbers. Deviations from maximization were also observed. Finally, we investigated the imperfect Bayesian decision-makers observed … …American Journal of Applied Sciences, Vol. 2, Issue 7 · 31 Jul 2005 · 6,760 accessesView PDFCite
Research ArticleOpen accessIn the abstractA Class of Region-preserving Space Transformations for Indexing High-dimensional DataRatko Orlandic, Jack LukaszukThis study introduces a class of region preserving space transformation (RPST) schemes for accessing high-dimensional data. The access methods in this class differ with respect to their space-partitioning strategies. The study develops two new static partitioning schemes that can split each dimension of the space within linear space complexity. They also support an effective mechanism for handling skewed data in … …Journal of Computer Science, Vol. 1, Issue 1 · 31 Mar 2005 · 6,926 accessesView PDFCite
Research ArticleOpen accessIn the abstractImpulse Volt-Time Characteristics of Oil and OIP InsulationS. Venkatesan, S. UsaEstimation of insulation strength of transformer oil and Oil Impregnated Paper (OIP) insulation, which constitutes major portion of insulation in power transformer, is an important task. Also, it is often necessary to evaluate the breakdown strength of oil and OIP under non-standard impulse voltages, since the oil and OIP insulation is subjected to non-standard waveshapes between inter-disc and inter-turn insulation. … …American Journal of Applied Sciences, Vol. 2, Issue 2 · 28 Feb 2005 · 7,244 accessesView PDFCite
Research ArticleOpen accessIn the abstractAn Investigation of the Effect of Aspect Ratio on the Airfoil PerformanceM. Kopaç, M. Yılmaz, T. GültopThe effect of aspect ratio on the airfoil performance is investigated for airflow about axially symetric wings as a function of the angle of attack. The magnitudes of aerodynamic forces and moments on airfoils resulting from the incompressible viscous flow fields are determined experimentally. The TE54 wind tunnel used for the experiments is an open conduit and has a 300x300 … …American Journal of Applied Sciences, Vol. 2, Issue 2 · 28 Feb 2005 · 7,688 accessesView PDFCite