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Articles 121 - 129 of 129
Full-Text Articles in Science and Technology Studies
Energy Storage System For Reduction Of Mid-Line Voltage Variation Of A Dfig Wnd Turbine Connected To A Weak Grid, M Aktarujjaman, Kashem M. Muttaqi, Michael Negnevitsky, Gerard Ledwich
Energy Storage System For Reduction Of Mid-Line Voltage Variation Of A Dfig Wnd Turbine Connected To A Weak Grid, M Aktarujjaman, Kashem M. Muttaqi, Michael Negnevitsky, Gerard Ledwich
Faculty of Engineering and Information Sciences - Papers: Part A
Penetration of wind power into electricity system is constantly increasing. Wind resources are usually distant from existing transmission lines. Wind farms are often connected to weak grids far from central generation stations. Maximum wind power extraction causes the more irregular and unpredicted power output of wind turbine, which has same nature as wind speed variation. The voltage in such long line is vulnerable with the consumption and generation imbalance. In a long line, the mid-line voltage is largely affected by the variation and the penetration of the wind fluctuating power. Fluctuating nature of wind power output and long transmission line …
Specifying System Requirements Using The 5s Method, Robert B. K Brown, Peter Hyland, Ian C. Piper
Specifying System Requirements Using The 5s Method, Robert B. K Brown, Peter Hyland, Ian C. Piper
Faculty of Engineering and Information Sciences - Papers: Part A
The 5S Method takes an Activity Theory approach to stakeholder elicitation. We interview stakeholders and build up a network of Activities according to Activity Theory precepts. These Activities are hierarchically decomposed into the smaller units of Action and Operation. This comprises a useful conceptual map of the human motivations and dependencies prior to insertion of the new computer based system. To identify and describe such a potential computer system, we analyse and identify linkages between the Activities and assemble a list of those which could usefully pass through such a computer system. Design decisions are driven and evaluated by reference …
Control Stabilisation Of An Islanded System With Dfig Wind Turbine, M Aktarujjaman, Kashem M. Muttaqi, Michael Negnevitsky, Gerard Ledwich
Control Stabilisation Of An Islanded System With Dfig Wind Turbine, M Aktarujjaman, Kashem M. Muttaqi, Michael Negnevitsky, Gerard Ledwich
Faculty of Engineering and Information Sciences - Papers: Part A
Distributed Generation (DG) is often used to export power to the utility system. Loss of main supply can cause a severe loading mismatch between DG generation and load consumption. Consequently, the voltage and frequency of the islanded system will cross the allowable limit. Due to this fact, it is essential to control the voltage and frequency in the islanding mode of operation. In this paper, control stabilisation of an islanded system with a doubly-fed induction generator (DFIG) wind turbine has been addressed. Wind DG produces variable output and is not capable to produce enough reactive power. Hence, it is imperative …
Dynamics Of A Hydro-Wind Hybrid Isolated Power System, M Aktarujjaman, Kashem M. Muttaqi, Michael Negnevitsky, Gerard Ledwich
Dynamics Of A Hydro-Wind Hybrid Isolated Power System, M Aktarujjaman, Kashem M. Muttaqi, Michael Negnevitsky, Gerard Ledwich
Faculty of Engineering and Information Sciences - Papers: Part A
Implementation of Distributed Generation (DG) can improve power quality and reliability, and guarantee continuity of power supply. This paper addresses the issue of continuity of power supply especially for isolated communities. A part of a network can be electrically isolated from the main grid when the grid fails to supply power due to a fault in the network or unavailability of power generation. In this paper, a mini hydro-wind hybrid power system is considered, and operation and control of the hybrid system during connecting it with the grid as well as its operation in the isolated condition are investigated. The …
Development And Characterization Of A High-Resolution Microspect System For Small-Animal Imaging, Yujin Qi, Benjamin Tsui, Yuchuan Wang, Brian Yoder, R Wojcik, S Majewski, A G Weisenberger
Development And Characterization Of A High-Resolution Microspect System For Small-Animal Imaging, Yujin Qi, Benjamin Tsui, Yuchuan Wang, Brian Yoder, R Wojcik, S Majewski, A G Weisenberger
Faculty of Engineering and Information Sciences - Papers: Part A
We developed a high-resolution microSPECT system and investigated its performance characteristics for small animal imaging. The microSPECT system consists of a stationary compact gamma camera with interchangeable pinhole and parallel-hole collimators and vertical object rotation mechanism. The modular camera is based on a pixellated NaI(Tl) crystal array with 1.2 mm pixel size and 1.4 mm pixel pitch coupled to a 5” diameter Hamamatsu R3292 PSPMT. The pinhole collimator has a 10cm focal length fitted with keel-edge pinhole apertures with diameters of 1.0, 1.5 and 2.0 mm. The system performance was characterized by the measurements of the point source response function …
Intersection Type Systems And Logics Related To The Meyer-Routley System B+, Martin W. Bunder
Intersection Type Systems And Logics Related To The Meyer-Routley System B+, Martin W. Bunder
Faculty of Engineering and Information Sciences - Papers: Part A
Some, but not all, closed terms of the lambda calculus have types; these types are exactly the theorems of intuitionistic implicational logic. An extension of these simple (→) types to intersection (or →∧) types allows all closed lambda terms to have types. The corresponding →∧ logic, related to the Meyer–Routley minimal logic B+ (without ∨), is weaker than the →∧ fragment of intuitionistic logic. In this paper we provide an introduction to the above work and also determine the →∧ logics that correspond to certain interesting subsystems of the full →∧ type theory.
Glass Formation In A (Ti,Zr,Hf)-(Cu,Ni,Ag)-Al High-Order Alloy System By Mechanical Alloying, L C. Zhang, Z Q. Shen, Jian Xu
Glass Formation In A (Ti,Zr,Hf)-(Cu,Ni,Ag)-Al High-Order Alloy System By Mechanical Alloying, L C. Zhang, Z Q. Shen, Jian Xu
Faculty of Engineering and Information Sciences - Papers: Part A
In this work, glass formation under high-energy ball milling was investigated for a (Ti0.33Zr0.33Hf0.33)50(Ni0.33Cu0.33Ag0.33)40Al10 high-order alloy system with equiatomic substitution for early and late transition-metal contents. For comparison, an amorphous alloy ribbon with the same composition was prepared using the melt-spinning method as well. Structural features of the samples were characterized using x-ray diffraction, transmission electron microscopy, and differential scanning calorimetry. Mechanical alloying resulted in a glassy alloy similar to that obtained by melt spinning. However, the glass formation was incomplete, and a …
Mr Damper And Its Application For Semi-Active Control Of Vehicle Suspension System, G Z. Yao, F F. Yap, G Chen, Weihua Li, S H. Yeo
Mr Damper And Its Application For Semi-Active Control Of Vehicle Suspension System, G Z. Yao, F F. Yap, G Chen, Weihua Li, S H. Yeo
Faculty of Engineering and Information Sciences - Papers: Part A
In this paper, a semi-active control of vehicle suspension system with magnetorheological (MR) damper is presented. At first a MR damper working in flow mode is designed. Performance testing is done for this damper with INSTRON machine. Then a mathematical model, Bouc–Wen model, is adopted to characterize the performance of the MR damper. With optimization method in MATLAB® and experimental results of MR damper, the coefficients of the model are determined. Finally, a scaled quarter car model is set up including the model of the MR damper and a semi-active control strategy is adopted to control the vibration of …
Mat: A Mobile Agent System For Supporting Autonomous Mobile Agents, Wei Li, Minjie Zhang
Mat: A Mobile Agent System For Supporting Autonomous Mobile Agents, Wei Li, Minjie Zhang
Faculty of Engineering and Information Sciences - Papers: Part A
Mobile Agent Template (MAT) is a mobile agent system that is under study and development at the Institute of Computing Technology, Chinese Academy of Sciences and sponsored by the University of Wollongong, Australia. MAT is not an alternative to other mobile agent systems, but is an agent system that can provide the autonomy to mobile agents. MAT tries to support new Web applications, such as the mobile computation, by autonomous and mobile agents. Mobile Thread Programming Model (MTPM), Distributed Task Plan (DTP) and Active State Space (ASS) are integral components on which MAT is constructed. Integration of these three components …