Novel Single Phase Dc-Ac Inverter Topology With Enhanced Power Quality

Inverters are widely employed in many application such as photovoltaic (PV), uninterruptable power supply (UPS) etc for the conversion of direct current (DC) power to alternating current (AC) power. The key challenges in design and implementation of inverters are the realization of higher efficiency and good quality output power. To achieve these, this thesis presents a novel single phase DC-AC inverter topology with enhanced power quality. In this topology, a switch is connected at the lower arm of the full-bridge switches to control the output voltage across the full-bridge inverter. The switch at the lower arm of the full-bridge controls the output of full-bridge inverter by increasing or reducing the voltage level at the lower arm of the bridge. This switch of lower arm is controlled by a high frequency sinusoidal pulse width modulation (SPWM) switching signal. While the power switches of full-bridge inverter operate with square wave switching signal at a frequency of 50 Hz. The proposed topology produces a clean sinusoidal output waveform with low distortion and with minimum switching losses, thus yielding high quality output at high efficiency. Next, a random switching hybrid pulse width modulation (HPWM) inverter is developed in order to give a comparison between the proposed inverter and the random switching HPWM inverter. Both computer simulation and experiment were carried out to verify the performance of proposed topology. From the presented results, it is shown that proposed topology has superior performance compared to its conventional counterpart

The development of a driver assist system with distance estimation using a single camera / Erma Rahayu Mohd Faizal Abdullah

In this thesis, an investigation on lane and vehicle tracking on a highway is carried out. The highway is chosen as the test ground due to the one-way flow of traffic, relative straightness of the road and consists of mostly automobiles. This study describes the development of a mid-line generation technique on the road as guidance for drivers to stay in the centre of the road lane they are currently driving on. The technique detects and tracks road lane in a video sequence and draws a virtual mid-line on the screen to guide the driver to stay centred within the lane

Tracing the P2P Botnets Behaviours via Hybrid Analysis Approach

P2P botnets has become central issue that threatens global network security. The unification of botnets and P2P technology make it more powerful and complicated to detect. P2P botnets generally known with abnormal traffic behaviours may highly impact the networks operation, network security and cause financial losses. In order to detect these P2P botnets, a highly-profile investigation on flow analysis is necessary. We consider hybrid analysis approach that integrate both static analysis and dynamic analysis approach. The hybrid analysis will be used in profiling the P2P behaviours and characteristics. Then, the findings of analysis results will contributes on P2P botnets behaviour pattern that will be used in constructing the general model of P2P botnets behaviour. Through the findings, this paper proposes a general P2P botnets behaviour model. The proposed model will be beneficial to further work on P2P botnets detection techniques

Professional Learning Community in Secondary Schools Community in Malaysia

This paper outlines a research towards an initial assessment of the stage of the PLC in secondary schools in Malaysians secondary school with teachers as the main focus. A brief philosophy of the importance of learning organization and its development in various countries was reviewed and incorporated by the current situations, leading to the objectives and methodology for this study. The result showed the teachers can be active in their learning and improving their schools as to enhance the learning performance of the students in the first four characteristic dimensions refer to the practice of shared values, goals, mission and vision among teachers which play an important role in shaping the PLC in secondary school

Modeling a Wave on Mild Sloping Bottom Topography and Its Dispersion Relation Approximation

Linear wave theory is a simple theory that researchers and engineers often use to study a wave in deep, intermediate, and shallow water regions. Many researchers mostly used it over the horizontal flat seabed, but in actual conditions, sloping seabed always exists, although mild. In this research, we try to model a wave over a mild sloping seabed by linear wave theory and analyze the influence of the seabed’s slope on the solution of the model. The model is constructed from Laplace and Bernoulli equations together with kinematic and dynamic boundary conditions. We used the result of the analytical solution to find the relation between propagation speed, wavelength, and bed slope through the dispersion relation. Because of the difference in fluid dispersive character for each water region, we also determined dispersion relation approximation by modifying the hyperbolic tangent form into hyperbolic sine-cosine and exponential form, then approximated it with Padé approximant. As the final result, exponential form modification with Padé approximant had the best agreement to exact dispersion relation equation then direct hyperbolic tangent form

Multiple linear regression parameters for determining fatigue-based entropy characterisation of magnesium alloy

This paper presents the development of the multiple linear regression approach based on the stress ratio and applied load that was assessed using entropy generation. The energy dissipation is associated with material degradation to determine the fatigue life with consideration to the irreversible thermodynamic framework. This relationship was developed by predicting a complete entropy generation using a statistical approach, where a constant amplitude loading was applied to evaluate the fatigue life. By conducting compact tension tests, different stress ratios were applied to the specimen. During the tests, the temperature change was observed. The lowest entropy generation was 2.536 MJm-3 K-1 when 3,000N load with a stress ratio of 0.7 was applied to the specimen. The assumptions of the models were considered through graphical residual analysis. As a result, the predicted regression model based on the applied load and stress ratio was found to agree with the results of the experiment, with only 9.3% from the actual experiment. Therefore, the entropy generation can be predicted to access the dissipated energy as an irreversible degradation of a metallic material, subjected to cyclic elastic-plastic loading. Thermodynamic entropy is shown to play an important role in the fatigue process to trace the fatigue life

PENGUJIAN BLACK BOX PADA WEBSITE PENDAFTARAN SISWA BARU DENGAN METODE GRAPH BASED TESTING

Sebuah sistem yang telah dibangun,  akan  melalui  tahapan  pengujian,  tahapan  pengujian  yang  dilakukan  menggunakan pengujian Black Box. Pengujian Black box merupakan pengujian perangkat lunak dimana yang diuji hanyalah fungsionalitasnya saja tanpa perlu menguji kode program atau pun desain dari perangkat lunak tersebut dan tanpa pengetahuan detil struktur internal dari sistem atau komponen yang dites. Pada awal tahun ajaran baru sekolah-sekolah melakukan pembukaan pendaftaran bagi calon siswa siswi secara serentak. Pendaftaran sekolah yang dilakukan pada saat ini sudah secara online. Pendaftaran secara online dilakukan melalui website yang dinilai lebih efektif dan efisien. Untuk mengetahui apakah aplikasi efektif dan efisien maka diperlukan pengujian terhadap system aplikasi website pendaftaran tersebut, yang mana untuk mengetahui apakah system tersebut berjalan sesuai dengan yang diharapkan atau tidak. Kata Kunci: Pengujian, Software, Black Box, Graph Based, Websit

Good Faith in Construction Contract: A Common Law Perspective

The good faith principle requires contracting parties to be honest as well as considering their contracting partners in performing their contractual duties. In the event, contract clauses are insufficient to protect the interests of the innocent party in a breached contract, the said innocent party may rely on the good faith principle to ensure the fair. However, applying good faith principles to construction contracts is a difficult task. By nature, construction contracts are unique due to the fact that parties (Client and Contractor) are presumed competent to carry out their parts of the contractual obligations. Controversially, the construction contract is often unfairly prejudicial as the Client would customarily have the upper hand in deciding the terms and conditions of a contract. It is the objective of the research to examine the relevancy of application of good faith principle in construction contracts by employing qualitative content analysis. This study adopts a qualitative research approach, mainly employing library and internet resources with the intention to explore relevant legislation, textbooks, journals, research papers and articles. The comparative approach in this paper used content analysis from primary and secondary legal resources of different jurisdictions in the United Kingdom, Malaysia and Australia to compare the application of the good faith principle in the context of construction contracts.  The findings of the research reveals that the adoption and application of the good faith principle in construction contracts is of limited usage even though it is widely used in general contract law of United Kingdom, Malaysia and Australia. This article contributes to the knowledge of the good faith principle in construction contracts, particularly with standard form contracts, by highlighting the importance of the good faith principle in achieving a fairer functioning of construction contracts in its application.  

USE OF SCENARIO PLANNING APPROACH TO EXPLORE HIGH-DENSE, MIXED-USE FUNCTION DISTRIBUTION: A CASE OF FINANCIAL VIABILITY, DAYLIGHT AVAILABILITY, AND SOLAR ENVELOPE RADIATION.

Master'sMASTER OF ARTS (ARCHITECTURE