Digital Commons Network^™

Impact Of Wind Generation Mix On Transient Stability For An Interconnected Power System, Lasantha Meegahapola, Damian Flynn, Jason Kennedy, Tim Littler

Dr Lasantha G Meegahapola

The rapid growth of wind generation in many European countries is pushing power systems into uncharted territory. As additional wind generators are installed, the changing generation mix may impact on power system stability. This paper adopts the New England 39 bus system as a test system for transient stability analysis. Thermal generator models are based on a likely future plant mix for existing systems, while varying capacities of fixed-speed induction generators (FSIG) and doubly-fed induction generators (DFIG) are considered. The main emphasis here has been placed on the impact of wind technology mix on inter-area oscillations following transient grid disturbances. …

Impact On Transient And Frequency Stability For A Power System At Very High Wind Penetration, Lasantha Meegahapola, Damian Flynn

Dr Lasantha G Meegahapola

This paper analyzes the impact on transient and frequency stability for a power system at very high wind penetration (40% wind). Wind penetration is based on the doubly-fed induction generator (DFIG), and a systematic approach has been adopted for wind power integration. A sensitivity analysis has been carried out for each wind integration scenario and for different wind generator loading conditions. A range of fault locations has been selected for stability analysis based on the proximity to synchronous generation and wind farms. The analysis has shown that transient stability performance is subject to fault location in the network, especially when …

Optimal Allocation Of Reactive Power Resources To Minimise Losses And Maintain System Security, Eknath Vittal, Lasantha Meegahapola, Damian Flynn, Andrew Keane

Dr Lasantha G Meegahapola

Modern doubly-fed induction generator (DFIG) wind turbines have significant reactive power control capability, even during low wind speed conditions. This can improve system security by providing terminal voltage control at buses in the system. Generally, such control employs the full range of reactive power production from the turbine which can lead to increased system losses. By utilizing optimal power flow analysis, and limiting the range of reactive power production at certain wind farms, system losses can be minimized. If the reactive power of the wind farms are optimized to achieve the minimum system losses this may adversely affect the voltage …

Transient Stability Analysis Of A Power System With High Wind Penetration, Lasantha Meegahapola, Damian Flynn, Tim Littler

Dr Lasantha G Meegahapola

This paper presents transient stability analysis for a power system with high wind penetration. The transient stability has been evaluated based on two stability criteria: rotor angle stability and voltage stability. A modified IEEE-14 bus system has been used as the main study network and simulations have been conducted at several wind power penetration levels, defined as a fraction of total system generation. A wide range of scenarios have been presented based on the wind farm voltage at the point of connection, i.e. low voltage (LV) distribution level and high voltage (HV) transmission level, and the type of wind generator …

Zach's News, Georgia Southern University, Zach S. Henderson Library

University Libraries News Online (2008-2023)

• HOT DOC: First Audio Book Available on GPO'S Federal Digital System

A Multi-Agent Solution To Distribution System Management By Considering Distributed Generators, Fenghui Ren, Minjie Zhang, Darmawan Sutanto

Dr Fenghui Ren

A traditional distribution network carries electricity from a central power resource to consumers, and the power dispatch is controlled centrally. Distributed generators (DGs) emerge as an alternative power resource to distribution networks at a smaller and distributed scale, which will bring benefits such as reduced voltage drop and loss. However, because most of high penetration DGs are not utility owned and characterized by high degree of uncertainty such as solar and wind, the distribution network may perform differently from the conventionally expected behaviors. How to dynamically and efficiently manage the power dispatch in a distribution network to balance the supply …

Ultrasensitive Detection Of Antibodies Using A New Tus-Ter-Lock Immunopcr System, Isabelle Morin, Nicholas E. Dixon, Patrick M. Schaeffer

Professor Nick E Dixon

A system consisting of a protein LG coated surface for the capture of mammalian antibodies (target), and an antigen fused to Tus and stoichiometrically linked to a DNA template via the Tus-Ter-lock sequence allowed the ultrasensitive detection of 5.5 attomol of target by real-time immunoPCR in complex media. © The Royal Society of Chemistry 2010.

Amplified Voices, But They Are Speaking To The Wrong People. Why The Complaint System For Unacceptable Advertising In Australia Is Not Working, Katherine Eagleton, Sandra C. Jones

Sandra Jones

This exploratory study highlights the lack of public awareness of the role of the Advertising Standards Board (ASB) in the process of handling complaints about unacceptable advertising in Australia. Results show that only a small proportion of Australian adults know that the ASB are the appropriate complaints handling body. This lack of awareness is evident even among those who have made a complaint about advertising (generally to a less appropriate body). This highlights the need for an education campaign to inform the general public how to make a complaint about inappropriate advertising, and who to make a complaint to. Empowering …

X-Tream: A Novel Dosimetry System For Synchrotron Microbeam Radiation Therapy, M Petasecca, A Cullen, I Fuduli, A Espinoza, C Porumb, C Stanton, A H. Aldosari, E Brauer-Krisch, H Requardt, A Bravin, V Perevertaylo, Anatoly B. Rosenfeld, M L. F Lerch

Anatoly Rozenfeld

Microbeam Radiation Therapy (MRT) is a radiation treatment technique under development for inoperable brain tumors. MRT is based on the use of a synchrotron generated X-ray beam with an extremely high dose rate ( ~ 20 kGy/sec), striated into an array of X-ray micro-blades. In order to advance to clinical trials, a real-time dosimeter with excellent spatial resolution must be developed for absolute dosimetry. The design of a real-time dosimeter for such a radiation scenario represents a significant challenge due to the high photon flux and vertically striated radiation field, leading to very steep lateral dose gradients. This article analyses …

Investigation Of Large-Scale Washover Of A Small Barrier System On The Southeast Australian Coast Using Ground Penetrating Radar, Brian G. Jones, C Bristow, Adam D. Switzer

B. G. Jones

Prehistoric depositional signatures for large-scale washover involving marine inundation events such as storm and tsunami have been the subject of considerable research over the last 15 years. Much of this research has focused on the identification of sand sheets in back-barrier environments as depositional records for extreme washover events. All these deposits must have a sediment source, and by their nature, the most likely source of sediment for washover into back-barrier environments is the barrier itself. This study identifies an erosional signature for large-scale washover from a small coastal barrier on the southeast Australian coast. A distinct lense of marine …

Specifying System Requirements Using The 5s Method, Robert B. K Brown, Peter Hyland, Ian C. Piper

Dr Ian Piper

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 …

The Institutional Legacy And The Development Of An Australian National Innovation System, Simon Ville

Simon Ville

Institutions are the rules of the game that help to shape the long-term historical development of societies. They mediate human interaction and can be more or less formal (or tangible) in nature ranging from systems of government to common modes of behaviour. Most formal institutions can be distinguished as economic, social, political or cultural in nature although such distinctions are more difficult to make for informal institutions. What is certain is the pervasive impact of all types of institutions on a country’s multifaceted development. Thus, economic performance may be shaped as much by a nation’s legal system as by its …

Conducting Polymers With Fibrillar Morphology Synthesized In A Biphasic Ionic Liquid/Water System, J.M. Pringle, Orawan Ngamna, Carol M. Lynam, Gordon G. Wallace, Maria Forsyth, Douglas Macfarlane

Gordon Wallace

The synthesis of poly(pyrrole), poly(terthiophene), and poly(3,4-ethylenedioxythiophene) with unusual fibrillar morphologies has been achieved by chemical polymerization in a biphasic ionic liquid/water system. Use of aqueous gold chloride as the oxidant, with the monomers dissolved in a hydrophobic ionic liquid, allows the polymerization to occur at the ionic liquid/water interface. The resultant conducting polymer fibrils are, on average, 50−100 nm wide and can be thousands of nanometers long. The polymers produced in this ionic liquid system are compared to those synthesized in a biphasic chloroform/water system.

Simulation Model Of A Grid-Connected Single-Phase Photovoltaic System In Pscad/Emtdc, Brian K. Perera, Sridhar R. Pulikanti, Philip Ciufo, Sarath Perera

Dr Philip Ciufo

In this paper, a complete simulation model of a grid-connected single-phase two-stage photovoltaic (PV) system with associated controllers is presented. The simulation model is developed in PSCAD/EMTDC simulation program. The component models of the grid-connected PV system include a PV array, a dc-dc boost converter, a voltage source converter (VSC) and an LCL filter. Components of the LCL filter, the dc-link capacitor of the VSC and the inductor of the dc-dc boost converter are established theoretically and that are used in modelling the grid-connected PV system. The control architecture of the presented system incorporates a synchronous reference frame phase-locked-loop (s-PLL), …

The Added Value Of Understanding Informal Social Networks In An Adaptive Capacity Assessment: Explorations Of An Urban Water Management System In Indonesia, Silva Larson, Kim S. Alexander, Riyanti Djalante, Dewi G.C Kirono

Faculty of Science, Medicine and Health - Papers: part A

Social networks play an important role in environmental governance regimes, and they are a key to the adaptive capacity of systems that deal with complex, contextual and multi-faceted issues. Urban water systems are typical examples of complex systems facing many pressures, such as increased population, water quality deterioration, and climate change. This paper explores social networks of the key stakeholders engaged in urban water management, in Makassar City, Indonesia, in the context of exploring ways to improve management of an increasingly complex urban water system. Three social networks were explored; those constituted by formal and informal interactions and networks perceived …

Systems Of Integration: Using System Dynamics To Understand Technology Integration In Learning And Teaching, Sarah K. Howard, Kate Thompson

Faculty of Social Sciences - Papers (Archive)

This paper presents the use of system dynamics to analyze factors impacting on teachers adoption and integration of technology in learning and teaching. Educational change is a complex and dynamic process, particularly in the area of technology integration. Existing models of teacher integration have not been designed to account for shifting and changing teacher experience, confidence and cultural aspects of technology integration. Therefore, the use of system dynamics is proposed to provide a more informed understanding of these interactions, with the aim to extend existing models of teachers' technology integration. This discussion applies this approach to analyze and model teachers' …

Ropes Eye Plaque Dosimetry: Commissioning And Verification Of An Ophthalmic Brachytherapy Treatment Planning System, J Poder, N Annabell, M Geso, M Alqathami, S Corde

Faculty of Engineering and Information Sciences - Papers: Part A

In this study, the Plaque SimulatorTM eye plaque brachytherapy planning system was commissioned for ROPES eye plaques and Amersham Health model 6711 Iodine 125 seeds, using TG43-UI data. The brachytherapy module of the RADCALC® independent checking program was configured to allow verification of the accuracy of the dose calculated by Plaque SimulatorTM. Central axis depth dose distributions were compared and observed to agree to within 2% for all ROPES plaque models and depths of interest. Experimental measurements were performed with a customized PRESAGEm 3-D type dosimeter to validate the calculated depth dose distributions. Preliminary results have shown the effect of …

Resonance Forever In A Rotational System: The Infinite Viv Lock-In Regime For Pivoted Cylinders, Brad Stappenbelt, Andrew Dennis Johnstone

Faculty of Engineering and Information Sciences - Papers: Part A

The aim of the present investigation was to examine the critical vortex-induced vibration (VIV) point for cylinders in a rotational system. For translational systems, the existence of a critical mass ratio for cylinders undergoing vortex-induced vibration has been well established. At mass ratios below this critical point, the reduced velocity at VIV lock-out tends to infinity, resulting in the resonance forever condition as described by the authors first reporting this phenomenon. The approach adopted in the present investigation involved measuring the VIV response of a positively buoyant pivoted cylinder being towed at very high reduced velocity. High reduced velocity was …

Teamwork As A Service: A Cloud-Based System For Enhancing Teamwork Performance In Mobile Learning, Geng Sun, Jun Shen

Faculty of Engineering and Information Sciences - Papers: Part A

Although cloud computing helps learners to access online learning content through commonly used devices, it can be difficult to collaborate in the mobile environment. We develop a service-oriented system, ‘Teamwork as a Service’ (TaaS), to facilitate learners’ team learning activities. The five main services of TaaS facilitate a teamwork-enhanced learning flow associated with the theory of Kolb’s team learning experience, providing learners with an introduction, a ‘jigsaw classroom’, schedule planning, and mutual supervision during the whole process. Specifically, TaaS enables a rational grouping mechanism that allocates learners to their appropriate tasks in order to give their best performance. TaaS is …

Facilitating Collaborative Learning In Taas: A Mobile Cloud System For Enhancing Teamwork Performance, Geng Sun, Jun Shen

Faculty of Engineering and Information Sciences - Papers: Part A

Mobile cloud-based learning is a novel trend that brings many advantages to distributed learners to achieve collaborative learning, but it still lacks of mechanisms to enhance their teamwork performances. To make up that shortcoming, combining the features of cloud environment, we have identified a learning flow, a specification of workflow, based on Kolb team learning experience. This novel learning flow can be executed by our newly designed system, Teamwork as a Service (TaaS), in conjunction with cloud-hosting learning management systems, following which learners benefit from functions given by cloudbased services, separately for organizing cloud jigsaw classroom, planning and publishing tasks, …

Total Electron-Scattering Cross Sections From Pyrimidine As Measured Using A Magnetically Confined Experimental System, Martina C. Fuss, Ana G. Sanz, Francisco Blanco, Juan Carlos Oller, Paulo Limao-Vieira, Michael J. Brunger, Gustavo Garcia

Faculty of Engineering and Information Sciences - Papers: Part A

In this paper, an apparatus for measuring electron-scattering cross sections while applying a strong axial magnetic field is described. The first original experiment performed with this setup is the measurement of the total cross sections for pyrimidine (1,3-diazine), which are presented for the incident electron energy range of 8-500 eV. Generally good agreement with earlier theoretical predictions is found after accounting for the angular acceptance (angular resolution for forward scattering) of the apparatus.

Validation Of An Imrt Beam Model Using A Secondary Treatment Planning System As A 3d Dosimeter, A Xing, S Arumugam, L Holloway, G Goozee

Faculty of Engineering and Information Sciences - Papers: Part A

A treatment planning system IMRT beam model is usually validated using phantom-based measurement, however this will not detect errors related to patient anatomy and inhomogeneity. In this study a secondary treatment system (CMS XIO) was used as a 3D dosimeter to verify an IMRT beam model recently commissioned in a Philips Pinnacle treatment planning system. Data sets from three head-neck and two prostate patients previously treated were utilised. The IMRT plans for these patients were planned in Pinnacle and transferred to XIO. The dose at each voxel in the patient volume was calculated in both XIO and Pinnacle. The 2D …

Innovations Of The Assessment System In Introductory Statistics Subject, Norhayati Baharun, Anne Porter

Faculty of Engineering and Information Sciences - Papers: Part A

This paper presents the results of a study investigating the innovations in the assessment system implemented in an introductory statistics subject (STAT131) at the University of Wollongong (UOW). For several years, innovations have been introduced to STAT131 particularly in the assessment system. These included the approaches of assignments, summary and mid-session test in 2003; assignments, laboratory work and midsession test from 2004 to 2005; four tests and three make-up tests in 2006; six tests with three compulsory and two optional tests in 2007; four tests (the best of three test marks were chosen) and opportunity to re-sit the tests in …

Reliability Modeling And Analysis For A Novel Design Of Modular Converter System Of Wind Turbines, Cai Wen Zhang, Tieling Zhang, Nan Chen, Tongdan Jin

Faculty of Engineering and Information Sciences - Papers: Part A

Converters play a vital role in wind turbines. The concept of modularity is gaining in popularity in converter design for modern wind turbines in order to achieve high reliability as well as cost-effectiveness. In this study, we are concerned with a novel topology of modular converter invented by Hjort, Modular converter system with interchangeable converter modules. World Intellectual Property Organization, Pub. No. WO29027520 A2; 5 March 2009, in this architecture, the converter comprises a number of identical and interchangeable basic modules. Each module can operate in either AC/DC or DC/AC mode, depending on whether it functions on the generator or …

Novel Modulation And Control Strategy For Five-Level Anpc Converter With Unbalanced Dc Voltage Applied To A Single-Phase Grid Connected Pv System, Hamid R. Teymour, Danny Sutanto, Kashem M. Muttaqi, Phil Ciufo

Faculty of Engineering and Information Sciences - Papers: Part A

This paper proposes a new control strategy and a novel modulation technique for a grid-connected photo-voltaic (PV) system using a single-phase five-level flying capacitor (FC) based active-neutral-point-clamped (ANPC) converter. The proposed modulator can control the FC voltage to follow the requested reference value and simultaneously generate the required ac output voltage regardless of the values of the dc capacitor voltages of the converter. By implementing this method, smaller values of dc-link and flying capacitors can be used even in applications that could experience ripple or transient in the capacitors voltage. In the grid-connected single-phase five-level ANPC, where the capacitors can …

Developing 'Policy Stories' For State Health System Benchmarking: A Small-N Quali-Quantitative Study, Erica Bell, Bastian Seidel

Faculty of Science, Medicine and Health - Papers: part A

Background: The benchmarking literature has made important advances and offers many different population health indicators that can be used to compare state health systems. However, there is still a need for qualitative, complexity-oriented approaches that allow policy-makers to develop explanatory 'policy stories' from combining such indicators that are useful to policy solutions. Methods: A new qualitative method from the social sciences based on Boolean approaches, called Qualitative Comparative Analysis (QCA), was piloted in a 'real world' policy consultancy to combine Australian state-level indicators of community and health system inputs, interventions, and population health outcomes. Analyses were provided for state inputs …

Ontology-Based Search System Using Hierarchical Structure Design, Norasykin Mohd Zaid, Sim Kim Lau, Mohd Nihra Haruzuan Mohamad Said

Faculty of Engineering and Information Sciences - Papers: Part A

Major retrieval issues on conventional online database search systems faced by novice researchers are identified and described. An ontology-based search framework is proposed. The framework consists of five elements: (1) user, (2) query, (3) query interface, (4) search process, and (5) result. The query interface is designed based on the ontology hierarchical structure in the ontology datastore and is represented as keywords/sub-keywords structures in the query interface. Ontology enables relationships between keywords and terms to be defined. Ontology allows desired information to be retrieved by sharing common vocabularies with an understanding of meaning of terms in the domain. A prototype …

A Multi Agent System Based Implementation For Semantic Web Services, J Shen, G Beydoun, G C. Low

Faculty of Engineering and Information Sciences - Papers: Part A

Many information systems developers face high cost in adopting service oriented architectures because of the high cost of locating appropriate services to customise and integrate into their system. This paper aims at reducing this cost by automating much of the composition and service selection effort. It illustrates the use of a Peer-Peer multi agent system (MAS) to facilitate service selection with multiple Quality of Service properties. The system will use semantic enrichment of services in order to facilitate their identification and composition. With semantic driven composition, services can be shared between teams of developers and across multiple organisations connected via …

Multi-Factor Coupling System Characteristic Of The Dynamic Roll Gap In The High-Speed Rolling Mill During The Unsteady Lubrication Process, Qiaoyi Wang, Zhengyi Jiang, Jingwei Zhao, Min Fang

Faculty of Engineering and Information Sciences - Papers: Part A

In the present work, a multi-factor coupling dynamic model of a rolling mill system for a dynamic roll gap during an unsteady lubrication process was developed on the basis of the rolling theory, lubrication and the friction theory, and the mechanical vibration theory. The multi-factor coupling model of interfacial film binding was coupled with the rolling force model, dynamic roll gap interface friction model and work roll movement model. The corresponding distributions of friction and pressure at varying surface roughness and times were systematically analyzed during the unsteady mixed lubrication process. The effects of the main processing parameters on the …

A Theoretical Investigation Of A Solar Photovoltaic Thermal System Integrated With Phase Change Materials, M Imroz Sohel, Zhenjun Ma, Paul Cooper, Jamie Adams, Robert Scott

Faculty of Engineering and Information Sciences - Papers: Part A

In this paper we present a theoretical investigation of an air based solar photovoltaic thermal (PVT) system integrated with phase change materials. The advantage of the air based PVT system is that the air can be directly used for space heating or cooling. At first we present an air based PVT system model and analyze the effect of major parameters on the system performance. We then integrate this PVT system model with a phase change material (PCM) energy storage system model and analyze the system performance. We found that solar irradiation increased thermal efficiency initially before reaching a plateau. However, …