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Abstract

This paper presents optimal preventive control actions using ant colony optimization (ACO) algorithm to mitigate the occurrence of voltage collapse in stressed power systems. The proposed objective functions are: minimizing the transmission line losses as optimal reactive power dispatch (ORPD) problem, maximizing the preventive control actions by minimizing the voltage deviation of load buses with respect to the specified bus voltages and minimizing the reactive power generation at generation buses based on control variables under voltage collapse, control and dependent variable constraints using proposed sensitivity parameters of reactive power that dependent on a modification of Fast Decoupled Power Flow (FDPF) model. The proposed preventive actions are checked for different emergency conditions while all system constraints are kept within their permissible limits. The ACO algorithm has been applied to IEEE standard 30-bus test system. The results show the capability of the proposed ACO algorithm for preparing the maximal preventive control actions to remove different emergency effects.

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, heteroatoms, heterocycles, and, in most cases, stereochemistry. The impact of this complexity is felt in other areas such as control strategy for impurities, solubility, length of synthesis, and cost of goods [ 6 ]. Molecular complexity has continued to rise

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.g., interpersonal conflicts, get academic work done, and eat healthfully) when using situational “proactive” self-control strategies (i.e., situation selection and situation modification) rather than cognitive “reactive” ones (i.e., attentional deployment, cognitive

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Abstract

In this paper, a single-phase to three-phase converter is proposed to provide variable output voltage and frequency. The proposed topology employs only six IGBT switches, which form the front-end rectifier and the output inverter for the one step conversion from single-phase supply to output three-phase supply. The front-end rectifier permits bidirectional power flow and provides excellent regulation against fluctuations in source voltage. Moreover, it incorporates active input current shaping feature. An easy method to implement control strategy is proposed. This control strategy ensures nearly unity input power factor with sinusoidal input current over the operating range. Based on sensorless vector control technique, the proposed converter is used for the speed control of the three-phase induction motor. A low cost motor drive can be achieved using the proposed converter and control technique. Simulation and experimental results are carried out to analyse and explore the characteristics of the low cost drive system.

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Helopeltis theivora is considered as one of the major pest in tea plantations causing considerable economic damage. Recent control strategies against this notorious polyphagous pest mainly depend on the application of insecticides. The study is focused on the antennal response of H. theivora on exposure to different insecticides using electroantenogram (EAG). The result showed that the insects perceive quinalphos as they are frequently exposed to it. The hierarchy of the EAG response of exposed and unexposed insects was quinalphos > bifenthrin > deltamethrin > thiamethoxam.

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Based on a nonlinear model, this article realizes an investigation of dynamic behaviour of a batch fermentation process using direct sensitivity analysis (DSA). The used nonlinear mathematical model has a good qualitative and quantitative description of the alcoholic fermentation process. This model has been discussed and validated by authors in other studies. The DSA of dynamic model was used to calculate the matrix of the sensitivity functions in order to determine the influence of the small deviations of initial state, control inputs, and parameters from the ideal nominal values on the state trajectory and system output in time. Process optimization and advanced control strategies can be developed based on this work.

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Traffic control strategies of signalized circular intersections are analyzed in this article after a brief overview of traffic lights in roundabouts. A detailed description was made on the ‘direct’ mode of operation of the Hungarian regulation describing three types of control program. Finally a comparison of traffic performance is given based on the main geometric features and parameters of the signal programs with a description of the signal plan structure. The PTV Vissim environment was used to examine and evaluate the performance of each combination through the average delay per vehicle resulting proposals for the application as well as for further studies in subject.

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Pollack Periodica
Authors: Ildiko Jancskar, Zoltan Sári, Adam Schiffer and Geza Várady

The paper suggests a design procedure for fuzzy cascade control. The expert knowledge based tuning procedure is supported by investigation the phase plane of the reference tracking. The plant is a one degree of freedom helicopter model with highly non-linear dynamics in a hardware-in-the-loop arrangement. Starting from a common fuzzy-PI controller in the outer loop and classic PI-controller in the inner loop, the presented tuning procedure enables to obtain fuzzy-adaptive parameter settings of the inner-loop and a heuristic modified rule base in the outer loop. The developed control strategy proves to be very successful: both the settling times and overshoots have become well regulated.

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Abstract

The pharmacological strategy to treat atrial fibrillation (AF) has been studied in the last years by a number of randomized studies. The overall results showed that the rhythm control strategy is not superior to the rate control strategy in terms of mortality or stroke, mostly due to limited efficacy and toxicity of antiarrhyhtmic drugs in the rhythm control patients. Regarding to these data, current antiarrhythmic therapy for recurrent AF is recommended on the basis of choosing safer, although possibly less efficacious drug. Flecainide, propafenone, sotalol and dronedarone are the first-line drugs for patients with a minimal or no heart disease, or hypertension without left ventricular hypertrophy. Sotalol and dronedarone are recommended as first-line drugs for patients with a coronary artery disease. Dronedarone should be considered in order to reduce cardiovascular hospitalizations related to AF/flutter. It can also be used safely in patients with hypertensive heart disease and stable NYHA class I-II heart failure. Amiodarone is the most effective antiarrhythmic in all clinical settings, but because of its toxicity profile should generally be used when other agents have failed or are contraindicated. Amiodarone is recommended as drug of choice in patients with severe heart failure or recently unstable NYHA class II.

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Abstract

As it is well known that due to the continuously decreasing trend of the alternative energy technologies and the increase in the costs of the traditional fossil fuels, the development of resident or commercial buildings with greatly reduced energy needs becomes a high ranked and more pressing scientific challenge. In topic with this technological and scientific provocation, the paper presents a LabView software-based building supervising and events monitor system designed and developed with the basic purpose to serve as support for net zero-energy control strategies implementation in intelligent buildings. Afterwards a brief presentation of the adopted intelligent building development strategy and the net zero-energy concept are presented and discussed. Once these theoretical aspects have been expressed and clarified, a multi-layer type implementation is unfolded, where the background layer is a building supervising and events monitor system. The main software development steps of this system are presented in details to prove the feasibility and reliability of the adopted implementation strategy.

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