Wide-Gain Range Bridgeless PFC Modified SEPIC Rectifier

With the increasing demand for power from the ac line and more strict limits for power quality, power factor correction has gained great attention in recent years. AII basic power converter topologies, such as Boost, Buck, Buck-Boost, and their variations, can be used to realize active PFC techniques. In this research, a new bridge less rectifier that operates with high power factor and high efficiency is investigated targeting LED and battery charging applications. The new topology is a high-power-factor rectifier, which is suitable for universal line base on a modified version of the single-ended primary inductance converter (SEPIC) operating in Discontinuous Conduction Mode (DCM). The new configuration also allows the reduction of the losses associated to the diode reverse recovery current. Furthermore, the proposed topology has wider gain than classical full bridge SEPIC converter, higher efficiency and lower current harmonics. Small signal analysis is used to model the variation affecting the rectifier circuit. Current Injected Equivalent Circuit Approach (CIECA) is utilized in modeling the small signal transfer function of the converter. Feedback control is applied to regulate output voltage around the desired reference and to reduce the effect of disturbances. Simulated results of the output voltage as function of input voltage disturbance and load change are presented

Improvement of wind turbine lightning receptor

Lightning receptor is a device attached to a wind turbine blade that will attract and assist lightning current flow to the ground. However, lightning does not necessarily strike it, instead the other part of the wind turbine is still been stroked by lightning eventually leading to catastrophe damage of the wind turbine. This research is aimed to develop a needle-type receptor on a wind turbine blade for lightning protection system (LPS). Other than that, this project is aimed to study the practical parameters of lightning protection system, including the relation between receptor size and electric field strength. The receptors were designed by three different disk diameters of 0.2 m, 0.5 m and 0.8 m. In 0.2m receptor diameter, the comparison between the numbers and length of needles presents that 32 number of needles and 0.3m length of needles can attract a higher electrical field than others. Each disk diameter consists of different needles number and length. Finite Element Method (FEM) has used for this research, the proper dimensions and shapes of receptors simulated by suggesting the minimum and maximum electric field that accumulates around receptors. The simulation study plays an active role in understanding and designing the receptor of wind turbines for an effective lightning protection system (LPS), but it requires a validation under actual condition

The Principal Al- Ain as an instructional Leader in Al - Ain School in the United Arab Emirates: A Case Study

This study aimed at identifying the extent of instructional leadership practices in Al-Ain government schools as perceived by teachers, the practices that this study investigated are related to five domains: schools goals, supervision ,curriculum, student performance and professional development. This study was guided by three research questions and used both quantitative and quantitative analysis in identifying the extent of instructional leadership Data for this study were collected through a survey using a Likert scale. It was sent to 644 teachers in Al - Ain public schools who taught in different grade levels, Teachers selected were males and females from different age group. Years of experience and qualification; and they were UAE nationals and foreign teachers Statistical tests included means, Percentages and standard deviations. One-way ANOVA test was used to analyze the quantitative part of the questionnaire. The answers to the open-ended questions in the last part of the questionnaire were analyzed qualitatively only four principals of different genders, ages, and years of experience. And educational backgrounds were interviewed. The aim of interviews was to know their perceptions about the extent of instructional leadership according to five domains. The results of this study showed opposite views from both sides. Teachers in Al- Ain schools perceive their principal’s instructional leadership behaviors as highly existent whereas the views of teachers in the interviews as positive. Further, the results also revealed that female principals tend to manage schools far better than the male principals do. Finally, what the school principals need was motivation to adopt leadership practices,Training by professional s who can understand their situation better, colleague who can share Experience and follow up with them and show them how and when to apply the leadership Practices effectively

The effect of board of directors and audit committee characteristics on firm performance : evidence from Malaysia

Corporate governance issues are under the attention of the researchers for over three decades due to the increasing global economic crisis. Hence, this study attempts to contribute towards literature by investigating relationships of corporate governance and firm performance in Malaysia as a developing country. In particular, the study investigates the relationship between the board of director’s characteristics and the audit committee characteristics and the performance of non-financial listed companies (excluding financial companies) in Malaysia for the two years (2014 and 2015). The model of this study is theoretically based on the agency theory. To examine the conceptual model, the required data were gathered from the annual reports of top 100 non-financial listed firms in Malaysia. In analyzing the data, this study utilized the liner multiple regression by taking the sample of 100 companies with 200 observations in order analyze the relationship between board of director’s characteristics and the audit committee characteristics and the performance (ROA and Tobin`s Q). Moreover, this study used firm size and leverage as control variables. Based on the liner multiple regression results that was used to examine the effect of the predictors of the firm performance measured by Return on Assets (ROA) and Tobin-Q. The statistical results showed that board size and foreigner board members were a positive determinant of Tobin-Q. While, the government link of board members was negative determinants of Tobin-Q. On the other hand, the government liking of the board and the audit committee meeting were negative predictors of ROA. While, the board size was a positive predictor of ROA. Besides providing suggestions for future research directions, this study also provides several recommendations for regulators, companies, stakeholders and in particular, the shareholders

Web-Based Brokerage System Development

Electronic Commerce (ecommerce) depends on the emergence of capabilities that empower buyers to obtain the product data they need to make informed purchase decisions, quickly and easily. Traditional physical markets are often brokered by intermediaries that facilitate market transitions by providing brokerage services. In the global Internet Electronic Brokers provide a central marketplace, and provide many essential third party services. Electronic Brokerages are regarded as the core functionality in overcoming many current limitation of Internet Commerce. Also, search costs, lack of privacy, incomplete information, contracting risk, and pricing are better managed with Electronic Brokers. However, Brokers are currently facing the problem of combining all the information within a single coherent structure through which buyers can navigate readily. This is due to the lack of interoperability standards between ecommerce applications, which leads to high costs for the brokers. The research is to design a framework for building a web-based brokerage system. The system plays a central role in allowing service providers to publish and advertise their offer and at the same time helping the consumer to access easily and in a moderate manner the offered services and information and try to solve the problem of interoperability. Consumer Buying Behavior model which consists of six stages that defines the decision process and acts of people involved in buying and using products had been applied in the design of the system. In addition to offering many essential third party services, the system offers some tasks, which simplify the functionality of brokers, which override the limitations of Internet e-commerce. Client-server communication that uses 3-tier architecture had been used to override the 2-tier limitations and enhance the security features of the system. To achieve the requirements of such as online e-commerce application Java servlets with JDBC on the server side, HTML and JavaScript on the client side are used. Unified Modeling Language (UML) had been applied in order to determine system structure and system behavior from user/system requirements. The study shows that online brokerage can replace traditional brokers with additional functionality. By designing reusable components and using certain tools will try to solve Interoperability problem between ecommerce applications. Java servlets shown as a powerful tool to be used on server side in this type of application which can help to override some limitations of Internet e-commerce

The Principal As an Instructional Leader in Al Ain Schools In the United Arab Emirates: A Case Study.

This study aimed at identifying the extent of instructional leadership practices inn Al Ain government schools as perceived by teachers. The practices that this study investigated are related to five domains: school goals, supervision, curriculum, student performance, and professional development. This study was guided by three research questions and used both quantitative and qualitative analysis in identifying the extent of instructional leadership. Data for this study were collected through a survey using a likert scale. It was sent to 644 teachers in Al Ain public schools who taught in different grade levels. Teachers selected were males and females, from different age group, years of experience and qualifications; and they were UAE national and foreign teachers. Statistical tests include means, percentages and standard deviations. One-way ANOVA test was used to analyze the quantitative part of the questionnaire. The answers to the open-ended questions in the last part of the questionnaire was analyzed qualitatively. Only four principals of different genders, ages, years of experience, and educational backgrounds were interviewed. The aim of interviews was to know their perceptions about the extent of instructional leadership according to five domains. The results of this study showed opposite views from both sides. Teachers in Al Ain schools perceive their principal instructional leadership as highly existent whereas the views of the teachers in the interviews as positive. Further, the results also revealed that female principals tend to manage schools far better than the male principals do. Finally, what the school principals need was motivation to adopt leadership practices, training by professionals who can understand their situation better, colleagues who can share experiences and follow up with them and show them how and when to apply the leadership practices effectively

The Educational Significance of the Qu'ranic Dialogue to Young Muslims in the West

This study sheds light on the ethical and social difficulties young Muslims face in the West. It aims to help Young Muslims fit socially without sacrificing their religion's principles, acquire Qu'ranic teachings and guidance, and assimilate Islamic principles and moral values that help them lead a righteous life. It attempts to achieve that by exposing young Muslims to the Qu'ranic educational significances and lessons and the moral values and Islamic principles derived from two types of Qu'ranic dialogue: the exchange dialogue and the speech dialogue. It seeks to develop a plan that enhances acquisition of ample Qu'ranic knowledge and guidance, assimilation of Qu'ranic ethical conducts, Islamic codes and social morals. It also seeks to provide Young Muslims with Qu’ranic teachings that strengthen their faith and immunity against non-Muslim passive social influences. As well, it helps Young Muslims refute the false claims about Islam. Moreover, this study recommends educationalists to help young Muslims eliminate indifference toward their religion, foster trust in themselves toward their Islamic identity and transfer this study into educational programs, and conduct further study from another perspective. Finally, this study concludes the abolition of young Muslims' ignorance of their religion and fostering the pure Islamic doctrine in their hearts

Comparison on the Bayesian Estimation of Gompertz Distribution Based on Type I Censored Data

The paper depicts assessment of the Bayesian methodology utilizing Gaussian quadrature formulas and Markov Chain Monte Carlo of the Gompertz distribution based on type I censored data with two loss functions, the Square Error loss function and the Linear Exponential loss function. In Markov Chain Monte Carlo, the full conditional distributions for the scale and shape parameters, survival and hazard functions are acquired by means Gibbs sampling and Metropolis- Hastings algorithm. The strategies for the Bayesian methodology are contrasted with maximum likelihood estimation regarding the Mean Square Error (MSE) to decide the best assessing of the scale and shape parameters, survival and hazard functions of the Gompertz distribution based on type I censored data. Keywords: Gompertz distribution, Bayesian estimation, Type I censored data, Gaussian Quadrature Formulas, Markov Chain Monte Carlo

Electronic democracy strategy for Bahrain

This thesis attempts to answer the question ‘What e-democracy strategy, if any, is most suitable for Bahrain?’. Based on a qualitative case study for the country, an e-Democracy strategy is synthesised and presented in this thesis. The literature review includes the forms, ideals and values of democracy. The researcher supports and argues for the assertion that any attempt to implement e-Democracy must not undermine the basic values and ideals of democracy. In the review on Islam and democracy, the author argues that Islam is not against democracy. However it is asserted that e-Democracy implementation must consider the cultural and religious context of Bahrain. The process of democratisation and how it is taking place in Bahrain and Gulf countries are also discussed. A strategy formulation framework is adopted after reviewing literature on how to formulate a strategy. E-Government strategies of reading players in the e-Government are reviewed with an objective of learning lessons prior to formulating e-Democracy strategy. The literature review on e-democracy helped to understand the theory and practice of e-Democracy elsewhere in the world and identify issues that required further investigation. The issues identified from the literature were investigated using empirical data. Data from multiple sources were collected and analysed. The methods included interviews, focus groups and analysis of documents. The results confirm that most of the issues identified as part of the literature review are relevant to the case under investigation. However, there were issues that were not present in the literature. This includes the need to consider democracy’s human, social and cultural aspects as well as factors pertaining to the political divide in Bahrain. This, if not tackled properly, may pose some challenges to the implementation of e-Democracy. The results also disprove the assumption held by the government of Bahrain, as well as by the researcher at the beginning of the study, that e-voting is a more plausible type of e-democracy than other forms. The author adapts and presents an e-Democracy model for Bahrain based on Chadwick and May (2003) along with the e-Democracy strategy for Bahrain. The author also argues that the model and the strategy can be tailored to use in other GCC countries. The study fills a gap in the literature, namely the lack of e-democracy studies pertaining to the Middle East. It also provides a framework and lessons for other countries in the region for the creation of an e-democracy strategy

Development of a framework for total quality management principles in the construction companies with special reference to the construction companies in the state of Qatar

PhDAn increased demand of quality in the construction industry has been a major cause of finding new systems and developing frameworks that are fit for purpose. Construction companies around the world are trying to increase their productivity and index of quality and they are developing new methodologies through research and development. Though innovation is, never completely good or bad and it is not easy to analyse the net effect. Theories and empirical research on materials, technology and innovation have been produced more than 100 years. In this, the framework for management and innovations of processes in construction industry has attracted the most interest, while other areas, such as the combination of technologies, construction companies‟ life cycles in Qatar and regulatory process have also been researched in detail. This research work has identified and addresses the important issues related to the implantation of Total Quality Management (TQM) in the construction sector in the State of Qatar. The main aim of the study is to develop and present to the construction companies in Qatar a new model that could not only improve the understanding of Total Quality Management (TQM) within their sector, but also help in developing the processes, procedures and operations by employing TQM framework in all sections of a company. Therefore, this thesis suggests a model based on existing and new quality management framework in Construction industry in Qatar. Furthermore, this thesis is a combination of the collected knowledge in different research traditions, and of observed studies of the Qatar Construction industry. The aim is to give a complete picture of the materials, technology, regulatory process and innovation and to provide a theoretical model, which can be used for existing and new management framework that may be implemented in the industry that has been referred as “client” in this study. This study examined one of the largest construction companies in Qatar as a case study to identify the current status and to highlight current barriers faced by construction companies in the implementation of Total Quality Management (TQM) philosophy. European Foundation Quality Management (EFQM) elements, identified through the iii TQM concept in the literature review, are used as a data collection framework while both the qualitative and quantitative methodologies are used to measure the level of perceptions among employees of the “client” construction company towards those elements. Moreover, the Critical Success Factors (CSFs) are reviewed based on previous studies in the literature review. The findings of this thesis suggest that TQM can be successfully implemented among Qatar‟s construction companies. The conclusions and recommendations are drawn from the best practice of TQM implementation as a guideline for the client construction company to consider in adopting the TQM philosophy. Furthermore, a framework has been suggested for the Client recommending the actions the Client should take to establish and implement a TQM framework, which will increase productivity, stream line the processes and improves the quality of the services and the products offered by the client