http://researchbank.rmit.edu.au/ RMIT University en Fez http://blogs.law.harvard.edu/tech/rss http://researchbank.rmit.edu.au/view/rmit:1591 In this paper, we provide a detailed description of an algorithm that implements join and prune mechanisms, which will help to build an optimal multicast tree with QoS requirements during handoff. An analysis is presented to show how mobility prediction can help in the selection of potential access routers (AR) with QoS requirements that affect multicast group size and bandwidth cost in the multicast tree. The proposed technique tries to minimise the number of multicast tree join and prune operations. We have examined the performance of this algorithm using simulations in various environments and obtained good performance results. Our results show that the expected multicast group increases linearly with the increase in the number of selected destination access routers (AR) for multicast during handoff. We observe that the expected number of joins and prunes from the multicast tree increases with group size. Thus, for an increased number of destinations, the estimated cost of the multicast tree in a cellular network also increases. 2009-04-08T00:00:00Z Venkatachalaiah, S og Suryasaputra, R og Harris, R http://researchbank.rmit.edu.au/view/rmit:11778 Not available 2011-08-19T00:00:00Z Bajwa, S og Weerasooriya, G og Sarvi, M og Kuwahara, M http://researchbank.rmit.edu.au/view/rmit:11777 Not available 2011-08-19T00:00:00Z Ryall, R og Bedford, A http://researchbank.rmit.edu.au/view/rmit:14973 Biometric techniques provide a feasible solution for protecting personal information at a high security level. However, biometric features themselves demand protection. As a promising method, fuzzy extractor seamlessly binds a cryptographic key to biometric features, in order to prevent both keys and features being exposed to attackers. Some related research has been done in this area however three major issues are still unsolved, which are : 1) Feature alignment 2) Verification accuracy. 3) Information leakage. In this paper, an alignment-free fingerprint fuzzy extraction scheme is proposed. To eliminate the alignment process, we use the minutia local structure features which has been proved to be stable, discriminative, rotation and shift free. The Dual Layer Structure Check (DLSC) verification scheme is base on the minutia local structure and it achieves a high verification performance. In this paper, we proposed a nearequivalent version of DLSC (NeDLSC) that can be directly employed by the existing bio-cryptographic constructions. Then a new fuzzy extractor scheme which is on the basis of NeDLSC is demonstrated. The preliminary experiments on publicly-available database FVC2002 shows a high verification accuracy. 2012-04-27T08:08:00Z Xi, K og Hu, J og Han, F http://researchbank.rmit.edu.au/view/rmit:15456 The present paper proposes an analog front-end (AFE) circuit, including only one low-noise amplifier with chopping techniques and one high-pass sigma-delta modulator (HPSDM), which can be applied as a sensing circuit for electroencephalogram or electrocorticogram (ECoG) signal acquisition systems. The low-noise amplifier, which has a close-loop gain of 20 V/V and CMRR of 109.6 dB, is implemented by a differential difference amplifier with feedback pseudo-resistors and capacitors. The HPSDM is implemented in a feed-forward architecture with an order of 3, an oversampling ratio of 128, and a 1-bit quantizer under a sampling frequency of 51.2 kHz. The TSMC 0.18 �m 1P6M CMOS process is used in the entire AFE circuit with a supply voltage of 1.2 V and power consumption of 28.7 �W. Within the maximum range of ECoG signals, the simulated SNR and SFDR of the entire AFE circuits are 70.8 and 73 dB, respectively. 2012-05-25T00:00:00Z Hong, J og Liang, M og Haung, M og Tsai, T og Fang, Q og Lee, S http://researchbank.rmit.edu.au/view/rmit:15443 Housing supply is one of important components of the housing sector. Compared with an increasingly strong housing demand, the growth rates of total housing stock in Australia have exhibited a downward trend since the end of the 1990s whilst the significant adjustments in the Australian monetary policy were being implemented. This research aims to estimate the nature of the relationship between housing supply and monetary policy by a vector error correction model. According to the empirical results, a transmission pattern comprised of the indicators associated with housing supply and monetary policy can be identified, which suggests that there is a significant interrelationship between monetary policy and the supply side of the housing sector in Australia. 2012-05-25T00:00:00Z London, K og Liu, J http://researchbank.rmit.edu.au/view/rmit:10865 We present the analysis and design of a FIR filter with balanced ternary coefficients (i.e., -1, 0, +1) suitable for FPGA implementation. The ternary filter taps were generated using a S-M process in MATLAB® and the filter implemented in VHDL. An efficient fast adder structure accumulates the partial multiplication products. Two alternative implementations in 2's complement and redundant binary signed digit representations are compared on a range of commercial FPGA devices for both pipelined and nonpipelined organizations. Using a high performance device, the filter can operate at clock rates of more than 400MHz. 2011-05-26T10:12:00Z Memon, T og Beckett, P og Hussain, Z http://researchbank.rmit.edu.au/view/rmit:17649 Complex networks are ubiquitous in the world. Many phenomena in nature can be described by the complex networks, such as brain structures, protein-protein interaction networks, scientific citation networks, food web, social interactions, the Internet, and so on. The study of complex networks is a young and active area of scientific research inspired largely by the empirical investigations of many real-world complex networks such as computer networks and social networks. It is very necessary to briefly review the main advances in the analysis, control and applications of complex networks over the last decade. 2012-11-26T09:22:00Z Lu, J og Chen, G http://researchbank.rmit.edu.au/view/rmit:11508 A statistical analysis of the single-delay multiplication based frequency estimator is treated here. The single-delay multiplication frequency estimator for complex single sinusoid signals is a phase averaged estimator, which is similar to the Kay's estimator. Here we provide a study on the statistical distribution of the frequency estimates made by the estimator, and verify the analytical results using simulations. It is shown that the analytical results hold true even at very low signal to noise ratio levels. In deriving the probability density function of the frequency estimates, we explore the cross product noise terms resulting due to the multiplication operation of the estimator by making valid assumptions. 2011-06-27T00:00:00Z Sithamparanathan, K og Reisenfeld, S http://researchbank.rmit.edu.au/view/rmit:13151 A methodology that uses multi-axial testing and dissipated energy (DE) to characterise the mechanical behaviour of laminated composite materials has been implemented into an analysis approach. The goal of this approach is to quantify the damage development on a continuum basis and eventually relate this damage to the constitutive behaviour of the material. The approach was implemented into a commercial finite element package with a custom user subroutine. Doublenotch characterisation specimens and open hole tension coupons were assessed. DE was predicted well in tension and in-plane rotation cases apart from a pure shear case where DE was excessive. DE magnitude was satisfactory in the open hole case and damage propagation well represented. Future work will involve advancing the technique to include DEdependent constitutive modelling. 2011-11-09T00:00:00Z Litchfield, A og Thomson, R og Orifici, A http://researchbank.rmit.edu.au/view/rmit:11105 Not available 2011-06-10T10:46:00Z Sun, S og Mohammed, R og Brandt, M og Clark, G og Liu, Q og Janardhana, M http://researchbank.rmit.edu.au/view/rmit:17650 Considering that optical networking is still in early stages of its evolution, Optical Burst Switching (OBS) is widely recognized as the most feasible data forwarding mechanism for the next generation Optical Internet that could be realized using currently available optical technology. OBS forwards data in a form of bursts of packets assembled and disassembled in the electrical domain in order to overcome the barrier of non-availability of optical memory. The purpose of this paper is to highlight the adverse effects of higher burst sizes on queue delay in the electrical domain in the presence of aggregate self-similar traffic, as that is found in a Differentiated Service (DiffServ) environment. Absolute effects on delay are highlighted by not using packet policing mechanism, similar to a token bucket, at the entrance of a network. This paper presents a combination of analytical and simulated results in verifying additional delays incur, and confirms them for all levels of aggregation and class-based (aggregate) utilization. In short, limitations, in general, in using larger burst sizes, which could deteriorate service quality, in an aforementioned environment, are emphasized. 2012-11-26T09:22:00Z Watagodakumbura, C http://researchbank.rmit.edu.au/view/rmit:18410 Ethanol, unlike petroleum, is a renewable resource that can be produced from agricultural feed stocks. Ethanol fuel is widely used by flex-fuel light vehicles in Brazil and as oxygenate to gasoline in the United States. Ethanol can be blended with gasoline in varying quantities up to pure ethanol (E100), and most modern gasoline engines well operate with mixtures of 10% ethanol (E10). E100 consumption in an engine is higher than for gasoline since the energy per unit volume of ethanol is lower than for gasoline. The higher octane number of ethanol may possibly allow increased power output and better fuel economy of pure ethanol engines vs. flexi-fuel engines. High compression ratio ethanol only vehicles possibly will have fuel efficiency equal to or greater than current gasoline engines. The paper explores the impact some advanced technologies, namely downsizing, turbo charging, liquid charge cooling, high pressure direct injection, variable valve actuation may have on performance and emission of a pure ethanol engine. Results of simulations are described in details providing guidelines for development of new dedicated engines. 2013-01-21T10:51:00Z Parker, A http://researchbank.rmit.edu.au/view/rmit:11684 The presence of impulsive noise in any power line channel is typical. In this paper, parameters such as 'interarrival' times are employed for the measurement of different impulsive noise scenarios. BER analysis is performed to compare the performance of the channel for the two types of impulsive noise under three different scenarios, with different number of subcarriers. 2011-08-12T00:00:00Z Al-Hinai, M og Sadik, A og Hussain, Z http://researchbank.rmit.edu.au/view/rmit:2553 Not available 2009-10-19T00:00:00Z Pirogova, E og Akay, M og Cosic, I http://researchbank.rmit.edu.au/view/rmit:2782 The lateral leakage behaviour of TM-based silicon-on-insulator thin-rib waveguides is analysed using mode matching technique. Both the TM-TE mode coupling properties and the leakage loss of propagating TM mode are investigated. 2009-11-25T08:00:32Z Nguyen, G og Sekhar, R og Webster, M og Koch, T og Mitchell, A http://researchbank.rmit.edu.au/view/rmit:17674 We propose to use the search log to study long queries, in order to understand the types of information needs that are behind them, and to design techniques to improve search ef- fectiveness when they are used. Long queries arise in many different applications, such as CQA (community-based ques-tion answering) and literature search, and they have beenstudied to some extent using TREC data. They are also, however, quite common in web search, as can be seen by looking at the distribution of query lengths in a large scale search log. In this paper we analyze the long queries in the search log with the aim of identifying the characteristics of the most commonly occurring types of queries, and the issues involved with using them effectively in a search engine. In addition, we propose a simple yet effective method for evaluating the performance of the queries in the search log using a combination of the click data in the search log with the existing TREC corpora. 2012-11-26T09:22:00Z Bendersky, M og Croft, B http://researchbank.rmit.edu.au/view/rmit:17962 Genetic Programming (GP) is reputable for its power in finding creative solutions for complex problems. However the downside of it is also well known: the evolved solutions are often difficult to understand. 2012-12-17T12:08:00Z Shi, Q og Yin, W og Song, A http://researchbank.rmit.edu.au/view/rmit:10848 This paper presents an analysis of research papers about programming education that were published in computing education conferences in the years 2005 to 2008. We employed Simon's classification scheme to identify the papers of interest from the ICER, SIGCSE, ITiCSE, ACE, Koli Calling and NACCQ conferences. Having identified the papers, we analysed the type of data collected, whether the analysis was qualitative, quantitative, or mixed, and the aims and outcomes being reported. 2011-05-26T10:12:00Z Sheard, J og Simon og Hamilton, M og Lonnberg, J http://researchbank.rmit.edu.au/view/rmit:11599 The significance of this research is that it is the first comprehensive analysis of cost performance across Australia. It is well known that measuring cost performance is not an easy task; comparisons of building projects on a 'like-for-like' basis are uncommon, and rarely occur in the real world. However, this paper analyses 120 different structural frame models that represent various; structural designs, construction methods, grid spans, and locations. 2011-07-11T00:00:00Z Mills, A http://researchbank.rmit.edu.au/view/rmit:1581 Learning goal-scoring behaviour from scratch for simulated robot soccer is considered to be a very difficult problem, and is often achieved by endowing players with an innate set of hand-coded skills, or by decomposing the problem into learning a set of simpler behaviours which are then aggregated into goal-scoring behaviour. When only basic skills are available to the player the fitness landscape is very flat, containing only a few thin peaks. As more human expertise is injected via hand-coded skills or a composite fitness function, more gradient information becomes apparent on the landscape and the genetic search is more successful. The work presented in this paper uses autocorrelation and information content measures to examine features of the fitness landscape to explain how the difficulty of the problem is changed by injecting human expertise. 2009-04-08T09:42:32Z Ciesielski, V og Riley, J http://researchbank.rmit.edu.au/view/rmit:14535 Flashover is damaging to the power transmission and distribution system. In this paper, correlation coefficient as a measure of nonlinearity is employed to analyze the leakage current signals generated from heavily polluted insulators for flashover prediction purpose. Data is generated with dry and wet conditions together with various supply voltages. By calculating the correlation coefficients between the supply voltages and the leakage currents, some patterns are found which may help identify the status of insulators. 2012-02-24T00:00:00Z Li, X og Feng, Y og Wong, K og Sokolowski, P og Yu, X http://researchbank.rmit.edu.au/view/rmit:1403 We describe a progression of solutions to a di ffi cult object detection problem, that of locating landmarks in X-Rays used in orthodontic treatment planning. In our fi rst formula tion an object detector was a genetic program whose inputs were a number of attributes computed from a scanning window. We used a rich function set comprising f+; ; -; ÷ ; min; max; ifthenelseg. Experimentation with di ff erent function sets revealed that using the function set f+; g gave detectors that were almost as accurate. Such detectors are essentially a linear combination of attributes so we also implemented a parameter optimization solution with a particle swarm optimizer. Contrary to expectation, the PSO detectors are more accurate and smaller than the GP ones. Our analysis of the reasons for this reveals that (1) the PSO approach involves a considerably smaller search space than the GP approach, (2) in the PSO approach there is a 1-1 mapping between genotype and phenotype while in the GP approach this mapping is many-1 and many semantically equivalent potential solutions are evaluated, (3) the fi tness landscape for PSO is a good one for search in that solutions are distributed in areas of high fi tness that are easy to locate while the GP landscape is much more di ffi cult to characterize and areas of high fi tness more difficult to find. 2009-04-08T09:42:32Z Ciesielski, V og Wijesinghe, D og Innes, A og John, S http://researchbank.rmit.edu.au/view/rmit:11317 In this paper, third-order intermodulation (IM3) distortion in BST varactors is analyzed based on the existing analysis methods for semiconductor varactor diodes. A polynomial expression is initially derived to predict the nonlinear behavior of the BST devices. A dual BST design, with the varactors in a parallel configuration with opposite bias voltages shows cancellation of the second-order distortion. Calculated and simulated results of the single and dual BST varactor configurations are compared where good agreement is observed. In the dual BST, significantly lower IM3 peaks are achieved at specific bias voltages but slightly higher IM3 peaks are achieved at certain bias voltage range compared to their single BST counterparts. Hence, a dual BST varactor configuration can reduce IM3 distortion at specific bias voltages. 2011-06-20T07:36:00Z Abdul Khalid, M og Holland, A og Ghorbani, K og Scott, J http://researchbank.rmit.edu.au/view/rmit:11086 This Using numerical simulation, the evolution of vortices in an aneurysm can be tracked. We examined large-scale swirling of blood within a significantly dilated aneurysm and quantified the pressure gradient and shear strain rate. Based on these fluid mechanical parameters, we are able to identify the difference in flow effects between the untreated and stented aneurysmal arteries. This study demosntrates that the large-scale vortex, pressure gradient and blood shear strain rate within an aneurysm sac reduces after stenting. 2011-06-10T09:22:00Z Wong, K og Thavornpattanapong, P og Chaichana, T og Sun, Z og Tu, J http://researchbank.rmit.edu.au/view/rmit:15967 Meeting customer satisfaction is an essential responsibility of power and utilities companies. Considering the property of customer's satisfaction degree, an analytical interval assessment method of voltage sag frequency is proposed. The customer satisfaction degree is presented by interval data corresponding to the voltage tolerance of the tested equipment installed at the customer side. Based on the determination function derived from the relationship between the voltage magnitude and the length of fault line in the power supply system, the critical fault positions are determined using an analytical iterative algorithm. By studying the variation in the satisfaction degree within a given interval range, the interval sag frequency is calculated. Moreover, the quantitative sag frequency is determined with the help of the interval sag frequency. After a comprehensive analysis, the proposed method is applied to a five-bus system and IEEE 30-bus reliability test system (RTS). A myriad of experiments based on different methods indicate that the proposed method is very credible and practical for the application. 2012-07-06T00:00:00Z Xu, W og Wang, Y og Xiao, X http://researchbank.rmit.edu.au/view/rmit:10868 This paper demonstrates the analytical design and optimisation of piezoresistive rectangular cantilevers with particular concern for the geometric factors and associated influences of the displacement response functions through an increase in damping. Microcantilever sensors with a higher frequency response ultimately proved critical due to their response to forces that vary rapidly in time. The increase of the damping due to the fluid loading was shown to be mostly dependent upon the reduction of the cantilever dimensions. Such a scaling downward of dimensions has the profound additional benefit of leading to a marked reduction in response time. Reducing the dimensions of the cantilever provides tangible benefits include: the reduction of the total noise, the maximization of sensitivity to modulations in the Brownian fluctuations from analyst binding and the capacity to account for Brownian noise relative to Johnson noise. 2011-05-26T00:00:00Z Sukuabol, S og Sood, D http://researchbank.rmit.edu.au/view/rmit:2529 It is important to measure how well Strategic Information Systems Planning (SISP) is done and how planning is improving over time. SISP measurement and assessment is associated with a huge amount of variables and interactions. SISP is confronted with two problems: a problem of comparing the importance of the tangible and intangible properties of its elements, measured by different scales, and a problem of synthesis of influence of these elements on the SISP constructs or the overall SISP success. The reported SISP measurement methods are not capable of overcoming these problems. This paper demonstrates a unique implementation of the Analytic thinking theory for establishing the relative and absolute importance of the SISP constructs. This theory is operationalized through the Analytic Network Process (ANP) and Analytic Hierarchy Process (AHP) methods which have capability to synthesize the various measures into a single overall measure of SISP maturity or SISP success. Based on AHP/ANP, the paper presents the framework for assessment and measurement of SISP maturity which is empirically validated in Australian environment. 2009-10-19T00:00:00Z Cheong, F og Pita, Z og Corbitt, B http://researchbank.rmit.edu.au/view/rmit:20167 Multimedia is increasingly accessed online and within social networks; however, users are typically limited to visual/auditory stimulus through media presented onscreen with accompanying audio over speakers. Whilst recent research studying additional ambient sensory multimedia effects recorded numerical scores of perceptual quality, the users' time-varying emotional response to the ambient sensory feedback is not considered. This paper thus introduces a framework to evaluate user ambient quality of multimedia experience and discover users' time-varying emotional responses through explicit user tagging and implicit EEG biosignal analysis. In the proposed framework, users interact with the media via discrete tagging activities whilst their EEG biosignal emotional feedback is continuously monitored in-between user tagging events with emotional states correlated with media content and tags. 2013-03-18T14:42:00Z Cheng, E og Davis, S og Burnett, I og Ritz, C http://researchbank.rmit.edu.au/view/rmit:1849 In this paper we analyse the reasons why evolving programs with a restricted form of loops is superior to evolving programs without loops for two problems which have underlying repetitive characteristics - a visit-every-square problem and a modified Santa Fe ant problem. We show that in the case of loops there is a larger number of solutions with smaller tree sizes. We show that the computational patterns captured in the bodies of the loops are reflective of repeating patterns in the domain. We show that the increased computational cost of evaluating an individual can be controlled by domain knowledge. 2009-07-31T09:45:47Z Li, X og Ciesielski, V http://researchbank.rmit.edu.au/view/rmit:13969 Recently, evolutionary dynamics on structured population has attracted an increasing attention in various fields. This paper aims at investigating the fixation probability of a mutant under random drift on a class of weighted networks. In particular, we have attained the analytical solutions of fixation probability of mutants on the weighted networks with three different updating rules, including link dynamics, Moran process, and voter model. It should be especially pointed out that the above analytical solutions can be used to further understand and control the evolution processes. Numerical simulations are also given to validate the above analytical solutions. 2011-12-22T00:00:00Z Tan, S og Lu, J og Setti, G http://researchbank.rmit.edu.au/view/rmit:12598 The aim of this paper is to investigate how much the effectiveness of a Question Answering (QA) system was affected by the performance of Machine Translation (MT) based question translation. Nearly 200 questions were selected from TREC QA tracks and ran through a question answering system. It was able to answer 42.6% of the questions correctly in a monolingual run. These questions were then translated manually from English into Arabic and back into English using an MT system, and then re-applied to the QA system. The system was able to answer 10.2% of the translated questions. An analysis of what sort of translation error affected which questions was conducted, concluding that factoid type questions are less prone to translation error than others. 2011-10-28T00:00:00Z Al-Maskari, A og Sanderson, M http://researchbank.rmit.edu.au/view/rmit:13116 Not available 2011-11-09T08:09:00Z Queiroz Batista Da Silva, C og Mahmood, A og Tari, Z http://researchbank.rmit.edu.au/view/rmit:19836 The growing concern for the environment and advancement in technology has led the automotive industries to develop green vehicles. The development of EV among alternative power-train has attained popularity. Replacing conventional power-train with an electric powertrain does not resolve the acoustic issues of vehicles. However, acoustic tests performed on EV shows that noise levels in the cabin are significant in high sensitivity region of human hearing. At present, limited research has been carried out in the acoustics of EV interiors due to the complexities involved in predicting noise level. This paper aims at developing an efficient method to optimize vehicle interior acoustics by characterizing interior trims. Alpha cabin and impedance tube experiments were conducted on porous materials to obtain acoustic and non-acoustic properties. The non-acoustic properties thus obtained were used as input parameters for a Statistical Energy Analysis (SEA) tool to obtain simulation results. Experiment and simulation results showed good correlation which would assist in creating a database of interior trims. The proposed method can therefore be used as an effective and efficient means to predict and optimize EV interior acoustic performance in the early design phase. The assistance of the developed analytical method in optimizing NVH performance has a significant impact on saving time and the cost of design. 2013-03-04T11:09:00Z Varghese, V og Egab, L og Rajan, V og Fard, M og Nakahie Jazar, G og Miller, J http://researchbank.rmit.edu.au/view/rmit:18882 An equivalent circuit, known as a Mason model, is proposed to characterize a novel ultrasonic motor in this study. This motor, which consists of a non-circular cross-section twisted beam and a piezoelectric element, generates coupled longitudinal-torsional vibration upon application of an electric field. The model predictions and experimental data are in good agreement. For example, under the condition of having input voltage of 100 Vpp, and driving frequency of 352.8 kHz, the model predicts a longitudinal velocity of 0.7 m/s compared to the experimental results of 0.65-0.75 m/s. The assumption is that the torsional velocity and longitudinal velocity are in a linear relationship; a proportionality coefficient K=0.259±0.012 is obtained through the experimental data by empirically fitting 2013-02-19T12:43:00Z Qi, A og Friend, J og Yeo, L http://researchbank.rmit.edu.au/view/rmit:11094 The performance of TCP over multi-hop wireless networks has been studied in extensive simulation experiments in the past decade, but few theoretical models have yet been introduced to capture the TCP behaviour over contention based MAC protocols, like IEEE 802.11. In this paper, a mathematical model is presented for a single TCP flow over a multi-hop wireless network with arbitrary number of hops, denoted by H in this paper. A stochastic modelling technique is used to formulate the performance of the TCP flow, based on its interaction with the underlying wireless medium. This model is derived for linear topology with static nodes. A statistical formula for the ratio of concurrent transmissions to the total is also introduced for a TCP flow over H wireless hops. The proposed mathematical model has been validated with simulation results indicating that the average deviation is less than 5%. 2011-06-10T09:22:00Z Azimi, F og Bertok, P http://researchbank.rmit.edu.au/view/rmit:1544 Caching is a commonly used technique for reducing access latency and improving scalability. However, the static nature of existing network caching techniques makes them unsuitable for wireless environments. As mobile clients move from one location to another, the performance of these caches deteriorates. To combat this problem, object relocation strategies can be used, where objects are dynamically relocated to locations near the moving clients. Existing work on object relocation have focused on achieving relocation transparency. Little attention has been given to the network overhead introduced by the relocation. In this paper, we propose a low overhead object relocation strategy suitable for wireless environments. Object lists are passed between nodes prior to relocation to ensure only the nearest copy of each object is relocated. We have developed detailed analytical models of the proposed strategy and a number of other strategies to facilitate comparison. Analytical and simulation results show the proposed strategy effectively reduce the effect of mobility on the performance of network caches. The relocation overhead of the proposed method is also significantly lower compared to existing schemes. 2009-04-08T09:42:32Z Lai, K og Tari, Z og Bertok, P http://researchbank.rmit.edu.au/view/rmit:14222 This paper reports on the recently completed and significant upgrade of the University of Wollongong' s Configurable Hemispheric Environment for Spatialised Sound (CHESS). The CHESS studio, which housed a 16 speaker hemisphere for creating spatial sound, has been converted into an anechoic chamber and a new 3D speaker system has been designed. The recent work is a continuation of a successful cross-disciplinary research activity between the Faculty of Informatics and the Faculty of Creative Arts. Also reported are new research initiatives that will be taking place in the facility. 2012-01-27T00:00:00Z Ritz, C og Schiemer, G og Burnett, I og Cheng, E og Lock, D og narushima, T og ingham, s og Conroy, D http://researchbank.rmit.edu.au/view/rmit:1482 A fine-grained reconfigurable array based on complementary, dual-gate, fully depleted, silicon on insulator (DGFD-SOI) nanowire transistors is proposed and analyzed. Both low power and reconfigurable operation may be achieved by altering the switching threshold of the array using the back-gate bias on the complementary double-gate transistors. Simulated performance figures are presented for the array when configured into representative circuits and compared with two similar self-assembled molecular arrays. It is shown that SOI nanowire arrays can achieve dense, low-power reconfigurable operation without the overheads of either level restoration or additional gain blocks that may be required by molecular-based systems. 2009-04-08T09:42:32Z Beckett, P http://researchbank.rmit.edu.au/view/rmit:13134 Today informationand communication technologies represent an important part of our life. Over the years, these technologies and regular innovations have led to a changed community, who recognizes the advantages of these technologies. Irrespective of the branch of trade, each company and all actors connected can benefit from such innovations, which enable ljfective and ljjicient cperatiol1s ill their daily processes. 2011-11-09T00:00:00Z Zwicker, M og Seitz, J og Wickramasinghe, N http://researchbank.rmit.edu.au/view/rmit:10937 Software process and product views should be closely linked in order to better manage quality improvement. However until now the two views have not been effectively synchronized. Current approaches to Software Configuration Management (SCM) are strongly based on files and lacking in logical and semantic understanding. Some impediments faced when modeling and analyzing software evolution include additional effort for dealing with language dependent source code analysis and continuous mining of the evolving system. By leveraging features offered by modern VMs and other enabling technologies, we have developed a language neutral architecture with extensibility mechanisms to support continuous Software Evolution Management (SEM). Our research aims to contribute to an SEM infrastructure where semantic artifacts can be consistently accessed, tracked and managed for performing software evolution analytics beyond the file-based model. This paper presents compelling factors for our infrastructure, the architecture we have developed, and then sketches a case study to demonstrate its application. 2011-06-02T15:22:00Z Sudaman, F og Mingins, C og Dick, M http://researchbank.rmit.edu.au/view/rmit:13135 Agent-based simulations are an increasingly popular means of exploring and understanding complex social systems. In order to be useful, these simulations must capture a range of aspects of the modeled situation, each possibly requiring distinct expertise. Moreover, different paradigms may be useful in modelling, ranging from those that use many lightweight reactive agents, to those that use cognitive agents, to those that focus on agent teams and organisational structures. There is need for an architecture which supports the development of a large simulation, through the integration of separately developed modules. This paper describes a framework and architecture which facilitates the integration of multiple agent-based simulations into a single global simulation. This architecture naturally supports distributed simulation and incremental development, which are ways of addressing the computational and conceptual complexity of such systems. In this paper we focus particularly on how to ensure proper management of simulation data that is affected by agents in different modules, at the same logical time. We also provide some preliminary performance evaluation addressing scalability, as well as a comparison of how other available systems handle the issue of shared data. 2011-11-09T08:09:00Z Scerri, D og Hickmott, S og Padgham, L og Drogoul, A http://researchbank.rmit.edu.au/view/rmit:14658 The use of dielectric stacks in radio frequency design is common. These stacks are often simplified to a volume average material to assist in the design process. This simplification, however, hides the frequency dependant nature of dielectric stacks. This paper illustrates the frequency dependence and highlights the cause and situations where it occurs. This frequency dependence is then exploited to design narrow-band window from a dielectric stack. This window has near total transmission and 0� phase delay at a particular frequency with high reflection outside the narrow-band transmission window. 2012-03-09T00:00:00Z Seidel, T og Galehdar, A og Rowe, W og Ghorbani, K http://researchbank.rmit.edu.au/view/rmit:16511 Gas-liquid bubbly flows with wide range of bubble sizes are commonly encountered in many industrial applications. Based on our previous study, a generalized Average Bubble Number Density (ABND) model has been developed to model the dynamical changes of bubble size due to bubble coalescence and breakage mechanism. With the aim to asses the model performance, numerical studies have been performed to validate the model predictions against experimental data. Three experimental data [7,10,12] exhibiting totally different bubble size evolution trends were strategically selected for the present validation study. Numerical predictions were validated against measured results under three different experimental conditions. In general, predictions of the ABND model yield good agreement with experimental data. The encouraging results demonstrated the capability of the ABND model in capturing the changes of bubbles size due to bubble interactions and the transition from "wall peak" to "core peak" gas volume fraction profiles under various flow conditions. Merits and drawbacks of the ABND model for industrial application are also discussed. 2012-08-06T00:00:00Z Cheung, C og Duan, X og Yeoh, G og Tu, J og Krepper, E og Lucas, D http://researchbank.rmit.edu.au/view/rmit:19828 Gas-liquid bubbly flows (i.e. swarm of discrete gas bubbles suspended in continuous liquid) have a wide range of applications; including mining, pharmaceutical and petroleum industries. Many researches have been carried out to develop an effective design tool for these industries and enhance the efficiency of their systems. Population balance (PB) approach in conjunction with Computational Fluid Dynamics (CFD) technique has been widely recognized as a robust methodology in solving such complex bubbly flows and providing a better understanding of the local flow behaviour. Nonetheless, to model the microscopic bubble interactions, an accurate coalescence and breakup kernel is crucial. Several models have been proposed within literatures for modelling breakup frequency and the daughter size distribution in the breakup mechanism; as well as coalescence frequency and efficiency in coalescence (Liao and Lucas 2009; Liao and Lucas 2010). A thorough assessment of the performance of a number of gas-liquid coalescence and breakage kernels has been carried out to find its effect in modelling the evolution of bubble size distribution in large scale vertical bubble column. A total of four different models were considered (one for breakage and three for coalescence) (Coulaloglou and Tavlarides 1977; Prince and Blanch 1990; Luo and Svendsen 1996; Lehr et al. 2002). To assess the performances under complex flow conditions, validation has been carried out against experimental data of Prasser et al. (2007) measured in the Helmholtz-Zentrum Dresden-Rossendorf (HZRD) facility. 2013-03-04T11:09:00Z Deju, L og Cheung, C og Yeoh, G og Tu, J http://researchbank.rmit.edu.au/view/rmit:17689 A population of serrated tussock at Diggers Rest just north-west of Melbourne has been identified as being resistant to the herbicide flupropanate. This has prompted a national mail survey of 5000 land managers impacted by serrated tussock across Australia. Survey results have shown that serrated tussock has spread widely throughout Victoria, NSW, ACT and Tasmania with 15 out of 400 respondents reporting resistance and requiring further investigation. The survey has also shown that serrated tussock is costing each land manager between $15,000 and $20,000 annually in control and lost production costs. This emphasises the importance of promoting integrated management of serrated tussock 2012-11-26T09:22:00Z McLaren, D og Ramasamy, S og Lawrie, A og Pritchard, G og Morfe, T http://researchbank.rmit.edu.au/view/rmit:12011 Abstract not available. 2011-09-19T00:00:00Z Crawford, R og Aranda-Mena, G og Froese, T http://researchbank.rmit.edu.au/view/rmit:20111 A subsurface pot irrigation system and a subsurface irrigation system with specially designed clay emitters were designed and tested to investigate the efficiency of the auto-irrigation systems for home gardens crop cultivation. The yield and development of curry chilies cultivated under the designed subsurface irrigation systems were compared with the yield and development of curry chilies under manual irrigation during three seasons; January - April, May - August and September - December. The yield obtained from the crop grown under designed irrigation systems is two times higher than the yield of crop grown under manual irrigation during dry seasons. The use of water under subsurface irrigation system with clay emitters was considerably less when compared with the subsurface pot irrigation. Both designed irrigation systems automatically control the water intake of soil when the soil is wet. 2013-03-18T14:42:00Z Navarathne, C og Weerasinghe, D og Jayasuriya, N http://researchbank.rmit.edu.au/view/rmit:11703 Cardiovascular disease (CVD) being the number one killer for many of the developed nations, real-time patient monitoring via the mobile phone network is increasingly becoming popular. The CVD patients, as subscribers for the CVD monitoring service providers, access to the facilities before initiating the dedicated services. However, this authentication must be secured, since the service providers often hold sensitive health information of their subscribers. In this paper, we propose a fully automated and integrated cardiovascular patient authentication system using patients ECG as a biometric entity. The proposed ECG recognition method is up to 12 time faster than existing ECG based biometric algorithms, requires up to 6.5 times less template storage, needs only 2.49 (average) acquisition time with the a high accuracy rate (up to 95%) when experimented a small population size of 15. With this new authentication mechanism in place, the cardiovascular patients no longer need to provide additional details like user name or password for identification purposes to access their health monitoring facility, making the remote tele-cardiology application faster than existing authentication approaches. 2011-08-12T10:33:00Z Khalil, I og Sufi, F http://researchbank.rmit.edu.au/view/rmit:18360 Not available 2013-01-21T10:51:00Z Osman, H og Georgy, M og Ibrahim, M