Simulation and reliability analysis of shunt active power filter based on instantaneous reactive power theory

This paper first discusses the operating principle of instantaneous reactive power theory. Then, the theory is introduced into shunt active power filter and its control scheme is studied. Finally, Matlab/Simulink power system toolbox is used to simulate the system. In the simulation model, as the most common harmonic source, 3-phase thyristor bridge rectifier circuit is constructed. The simulation results before and after the shunt active filter was switched to the system corresponding to different firing angles of the thyristors are presented and analyzed, which demonstrate the practicability and reliability of the proposed shunt active filter scheme.

An Interpretation of The Color Purple from the Perspective of Foucault’s Power Theory

Afro-American writer Alice Walker is one of most influential black women writers in the American literary world of the twentieth century.She has long time focused on the living conditions of the black,especially black females under the ethnic context.Through Foucault’s power theory,the operating mechanism of power the in The Color Purple can be clearly elaborated.On the one hand,patriarchal disciplinary power sets numerous restrictions on individuals for the purpose of producing docile bodies.On the oth⁃er hand,the disciplined individuals take the body as a site of protest against disciplinary power,so as to construct their own dis⁃course,free themselves from the marginalized living status and realize the promise of reconciliation between sexes and races.

Is the Purchasing Power Parity Supported by the Data？

This report mainly examines whether the Purchasing Power Parity （PPP） theory is supported by the data. The data used in the report contains the exchange rate of US dollar against New Zealand dollar, Consumer Price Index （CPI） of the US, and Consumer Price Index of New Zealand. The time period of the data is from September 30th, 1914 to March 31st, 2010, the data were collected quarterly. Mathematical regressions and graphs are contained in the research. In this research, the simplified form of the PPP theory is analyzed, and then there is a comparison between the spotted exchange rates and the expected exchange rates. Finally, the observation on long-run PPP is explained. The key conclusion of this research is that, the PPP theory is not supported by the data, however, the long-run PPP does hold.

Kubelka-Munk Revised Theory for High Solar Reflectance and High Long-wave Emissivity Coatings Designing

The Kubelka-Munk revised theory was adopted to derive the mix design theory of high solar reflectance and high emissivity coatings.When the concentration of each colorant is within 20%,and the width of the coating is more than 200 μm,each colorant has enough covering power in visible and near-infrared spectral range.It can be assumed that the addition of colorants in coatings can only change the solar spectral absorption ratio rather than solar spectral scattering coefficient.The spectral scattering coefficient of coatings tends to a constant.The spectral absorption-scattering property of each colorant can be characterized through one parameter.The spectral absorption-scattering coefficient of coatings can be calculated with the multivariate linear relationship of each pigment.Moreover,the results can be expanded for high solar reflectivity and high long-wave emissivity coating preparation.The accuracy of Kubelka-Munk revised theory has been tested and verified through comparison between the calculated value and tested value of coating reflectance.

The Role of Sports Diplomacy in Advancing Environmental Security in Africa: Case of Forest Conservation in Kenya

Environmental security remains a key challenge in the late 19th through to the 21st century,whose solution has attracted a number of initiatives.Sports diplomacy has achieved great strides in achieving international,regional,and local unity.However,the use of sports diplomacy in achieving environmental security has received much less research attention.This research examines the role of sports in diplomacy in achieving environmental security in Kenya.This study was anchored on the soft power theory and Conservation of Resources(COR)theory which offer frameworks for explaining the role of sports diplomacy in advancing environmental security.The study adopted exploratory research design.The target population was diplomats,marathoners,coaches,environmentalists,conservationists and government officials,academia as well as Water Resources Authority(WRA).The primary data were obtained through open and closed structured questionnaire.The collected data were analyzed through the use of frequency distribution,and thematic analysis.The study established that sports diplomacy advanced environmental security in Kenya,which was better for athletics and volleyball.Environmental security was also enhanced through training,sensitization,conservation efforts,and environmental education.Sport events also allowed a contact-platform for interaction between various groups involved in environment and forest conservation.This study recommends that sports diplomacy should be used in most of the regions in Kenya experiencing environmental perturbations and the current strategies should be applied in the sports diplomacy and environmental conservation as well as security.Further,the government is also encouraged to appoint more sports ambassadors with proper environmental knowledge to help in environmental management.The role of academicians in sports diplomacy and environmental security was found to be minimal where academicians should be at the forefront as the 21st century diplomats are incorporated into sports to be local ambassadors.Perceiving the significance of sports diplomacy and environmental security,there is need for coordination between various county governments to coordinate their efforts and in the process they should bring on board even the non sports actors to boost the role of sports in diplomacy and environment.

FPGA Resources Reduction by a Multiplexing Technique Applied on ANN-Based Harmonics Extraction Algorithms

In this paper, a multiplexing technique is applied on a neural harmonics extraction method, based on an efficient formulation of the instantaneous reactive power theory. This approach can be used in nonlinear loads compensation with APFs （Active Power Filters）. The architecture for reference current generation, synchronized by a neural phase lock-loop, is composed of three Adaline neural networks. This leads to an important consumption of field programmable gate array resources during implementation. The proposed technique uses only one Adaline and keeps the immunity of the approach under non-sinusoidal and unbalanced conditions of voltage. Simulation results of the neural harmonics detection system connected to a reference current controller show balanced and sinusoidal source currents under various conditions. Results with experimental measurement made on an APF test bench demonstrate its good performances on harmonics filtering. Moreover, the simplified structure from the new approach called mp-q method shows a significant resource reduction.

Quantifying Likelihood in Digital Forensic Investigations

While the conventional forensic scientists routinely validate and express the results of their investigations quantitatively using statistical measures from probability theory,digital forensics examiners rarely if ever do so.In this paper,we review some of the quantitative tools and techniques which are available for use in digital forensic investigations,including Bayesian networks,complexity theory,information theory and probability theory,and indicate how they may be used to obtain likelihood ratios or odds ratios for the relative plausibility of alternative explanations for the creation of the recovered digital evidence.The potential benefits of such quantitative measures for modern digital forensics are also outlined.

A Game Theoretic Approach for Inter-Network Interference Mitigation in Wireless Body Area Networks

Wireless Body Area Network(WBAN) is an emerging technology to provide real-time health monitoring and ubiquitous healthcare services. In many applications, multiple wireless body area networks have to coexist in a small area, resulting in serious inter-network interference. This not only reduces network reliability that is especially important in emergency medical applications, but also consumes more power of WBANs. In this paper, an inter-network interference mitigation approach based on a power control algorithm is proposed. Power control is modeled as a non-cooperative game, in which both inter-network interference and energy efficiency of WBANs are considered. The existence and uniqueness of Nash Equilibrium in the game are proved, and an optimal scheme based on best response is proposed to find its Nash Equilibrium. By coordinating the transmission power levels among networks under interference environment, the total system throughput can be increased with minimum power consumed. The effectiveness of the proposed method has been illustrated by simulation results, where the performance of the proposed approach is evaluated in terms of overall utility and power efficiency and convergence speed.

Re-interpretation of the classical geopolitical theories in a critical geopolitical perspective

Struggling for supremacy between great powers and the rise or fall and regime change of great powers are all subject to the Geopolitical Law. Geographers should keep in step with the times, accurately grasp the national interests, and seize the opportunity to contribute to the great rejuvenation of our nation. However, due to lack of criticism on the history and philosophy of geopolitics, we can neither accurately understand the geopolitical theory, nor effectively put the geopolitical theory into practice. This paper introduces the development of critical geopolitics, summarizes the three characteristics of critical geopolitics, and interprets the four classical geopolitical theories accordingly. In order to simplify the interpretation process, this paper firstly presents an analytical framework for interpretation of four classical geopolitical theories; secondly, focuses on interpretation of "The Geographical Pivot of History" put forward by Mackinder according to the analytical framework; finally, critically summarizes the four classical geopolitical theories. Through the critical interpretation, this paper draws a conclusion that there are the scientific, hypothetical and conceptual classical geopolitical theories. The construction of classical geopolitical theories is based on the international geopolitical structure, spatial distribution of national interests and inter-state spatial conflict, in order to show the identity of theoretical constructor, so as to reflect the historicality, sociality, situationality and geographical knowledge – power structure of geopolitical theories.

A Combined Reinforcement Learning and Sliding Mode Control Scheme for Grid Integration of a PV System

The paper presents development of a reinforcement learning(RL)and sliding mode control(SMC)algorithm for a 3-phase PV system integrated to a grid.The PV system is integrated to grid through a voltage source inverter(VSI),in which PVVSI combination supplies active power and compensates reactive power of the local non-linear load connected to the point of common coupling(PCC).For extraction of maximum power from the PV panel,we develop a RL based maximum power point tracking(MPPT)algorithm.The instantaneous power theory(IPT)is adopted for generation reference inverter current(RIC).An SMC algorithm has been developed for injecting current to the local non-linear load at a reference value.The RL-SMC scheme is implemented in both simulation using MATLAB/SIMULINK software and on a prototype PV experimental.The performance of the proposed RL-SMC scheme is compared with that of fuzzy logic-sliding mode control(FL-SMC)and incremental conductance-sliding mode control(IC-SMC)algorithms.From the obtained results,it is observed that the proposed RL-SMC scheme provides better maximum power extraction and active power control than the FL-SMC and IC-SMC schemes.

Authoritarian leadership and task performance:the effects of leader-member exchange and dependence on leader

This study examines how and when authoritarian leadership affects subordinates’task performance.Using social exchange theory and power dependence theory,this study proposes that authoritarian leadership negatively influences task performance through leader-member exchange(LMX).This study further proposes that the effect of authoritarian leadership on LMX is stronger when a subordinate has less dependence on a leader.A two-wave survey was conducted in a large electronics and information enterprise group in China.These hypotheses are supported by results based on 219 supervisor-subordinate dyads.The results reveal that authoritarian leadership negatively affects subordinates’task performance via LMX.Dependence on leader buffers the negative effect of authoritarian leadership on LMX and mitigates the indirect effect of authoritarian leadership on employee task performance through LMX.Theoretical contributions and practical implications are discussed.

Concept and design of super junction devices

The super junction（SJ） has been recognized as the ＂milestone＂ of the power MOSFET, which is the most important innovation concept of the voltage-sustaining layer（VSL）. The basic structure of the SJ is a typical junction-type VSL（J-VSL） with the periodic N and P regions. However, the conventional VSL is a typical resistance-type VSL（R-VSL） with only an N or P region. It is a qualitative change of the VSL from the R-VSL to the JVSL, introducing the bulk depletion to increase the doping concentration and optimize the bulk electric field of the SJ. This paper firstly summarizes the development of the SJ, and then the optimization theory of the SJ is discussed for both the vertical and the lateral devices, including the non-full depletion mode, the minimum specific on-resistance optimization method and the equivalent substrate model. The SJ concept breaks the conventional＂silicon limit＂ relationship of R_（on）∝V_B^（2.5）, showing a quasi-linear relationship of R_（on）∝V_B^（1.03）.