Variation in time between two successive heart beats occurring due to internal and external stimulation causes Heart Rate Variability (HRV). HRV is a tool for indirect investigation of both cardiac and autonomic system function in both healthy and diseased condition. It has been speculated that HRV analysis by nonlinear method might bring potentially useful prognosis information into light which will be helpful for assessment of cardiac condition. In this study, HRV from two types of data sets (normal sinus rhythm and sinus arrhythmia) are analyzed which are stored in MIT-BIH (Massachusetts Institute of Technology -Beth Israel hospital) database, an extended collection of recorded physiological signals. Then two nonlinear methods, approximate entropy (ApEn) and detrended fluctuation analysis (DFA), have been applied to analyze HRV of both Arrhythmia patients and people having normal sinus rhythm. It has been clearly shown that nonlinear parameters obtained from these two methods reflect the opposite heart condition of the two types of subjects under study, healthy and diseased, by HRV measures. Thus, value of the nonlinear parameters found in this work can be used as standard when treating suspected patients for diagnosis of Arrhythmia. Also, by measuring these nonlinear parameter values, heart condition can be understood.978-1-4799-0400-6/13/$31.00 ©2013 IEEE

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The Existing power system networks were designed at a time when there was virtually no embedded generation, and hence the design accommodated the voltage drop expected due to the load, and impedances of the conductors used. As solar PV generation started to grow, the rise in voltage due to ohms Law, started to push network voltages towards, and even above, the desired upper limits. Voltage limits are based on typical appliance requirements and long-term over-voltages will ultimately result in unacceptably short appliance life spans. performance of low voltage networks can be improved by Distribution Static Compensators (dSTATCOMs) using reactive power injection. This paper investigated the application of low voltage STATCOMs at optimal locations for the management of distribution system voltages. This paper presents a case study on the application of an optimization tool to four Energy Queensland (Energex) distribution feeders. They are modelled in Open Distribution System Simulator (OpenDSS). The optimization algorithm is coded in MATLAB which calls upon OpenDSS model to run load flow in each iteration. These feeders are tested on five different scenarios such as highest loading conditions and highest generations to demonstrate the effectiveness of the optimization tool in placing the dSTATCOM in the optimum location.

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This paper proposes control augmentations to allow two Static Synchronous Compensators (STATCOMs) devices to operate in parallel from a shared DC bus. Two parallel connected four-wire STATCOMs will be shown to be highly susceptible to an uncontrolled circulating current in the neutrals when operating with a three degree of freedom current control scheme. The circulating current can be calculated from the local inverter phase currents and neutral current. This paper shows the circulating component is readily suppressed by a neutral voltage offset that is determined by a proportional controller (P). The controller is validated by both simulation and experimental results.INDEX TERMS-Four-leg STATCOMs, neutral current control, parallel three phase inverter, proportional control.