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Faculty of Engineering and Information Sciences - Papers: Part A

2015

Systems

Articles 1 - 15 of 15

Full-Text Articles in Social and Behavioral Sciences

On Transformation Of Query Scheduling Strategies In Distributed And Heterogeneous Database Systems, Janusz R. Getta, - Handoko Jan 2015

On Transformation Of Query Scheduling Strategies In Distributed And Heterogeneous Database Systems, Janusz R. Getta, - Handoko

Faculty of Engineering and Information Sciences - Papers: Part A

This work considers a problem of optimal query processing in heterogeneous and distributed database systems. A global query sub- mitted at a local site is decomposed into a number of queries processed at the remote sites. The partial results returned by the queries are in- tegrated at a local site. The paper addresses a problem of an optimal scheduling of queries that minimizes time spend on data integration of the partial results into the final answer. A global data model defined in this work provides a unified view of the heterogeneous data structures located at the remote sites and a ...


A Survey Of Single And Multi-Hop Link Schedulers For Mmwave Wireless Systems, Jian Song, Kwan-Wu Chin Jan 2015

A Survey Of Single And Multi-Hop Link Schedulers For Mmwave Wireless Systems, Jian Song, Kwan-Wu Chin

Faculty of Engineering and Information Sciences - Papers: Part A

Wireless communication at 60. GHz, aka mmWave, provides extremely high data rates, i.e., several Gb/s. Moreover, devices have a much shorter transmission range as compared to those operating in the 2.4 and 5. GHz bands. Indeed, links can be treated as pseudo-wires with minimal interference leakage. As a result, future 60. GHz systems will have very high spatial reuse. This, however, is at the expense of high propagation loss, which can be overcome using directional or smart antennas. Another promising solution is to employ relays to boost the signal of weak links. In particular, if relays are ...


Effective Utilization Of Excess Energy In Standalone Hybrid Renewable Energy Systems For Improving Comfort Ability And Reducing Cost Of Energy: A Review And Analysis, M Ismail Ismail, Mahmoud Moghavvemi, T Mahlia, Kashem M. Muttaqi, S Moghavvemi Jan 2015

Effective Utilization Of Excess Energy In Standalone Hybrid Renewable Energy Systems For Improving Comfort Ability And Reducing Cost Of Energy: A Review And Analysis, M Ismail Ismail, Mahmoud Moghavvemi, T Mahlia, Kashem M. Muttaqi, S Moghavvemi

Faculty of Engineering and Information Sciences - Papers: Part A

One of the features that characterize renewable energy sources is their variability and intermittency. Intermittency covers both the predictable and unpredictable variations of their power outputs and uncertainty in the power availability. To overcome the drawback of intermittency, special design considerations should be taken into account. These additional design considerations increases the overall cost of the renewable energy systems. Adding storage system and/or backup source to the renewable sources is one of the measures used to guarantee the continuity of power supply to the loads, and therefore improve the reliability of the renewable energy systems. The operation of renewable ...


Exact Error Performance Analysis Of Binary Space-Time Block Coded Cooperative Communications Systems In Rayleigh Fading Channels, Le Chung Tran, Zixuan Lin, Farzad Safaei, Alfred Mertins, Duy T. Ngo Jan 2015

Exact Error Performance Analysis Of Binary Space-Time Block Coded Cooperative Communications Systems In Rayleigh Fading Channels, Le Chung Tran, Zixuan Lin, Farzad Safaei, Alfred Mertins, Duy T. Ngo

Faculty of Engineering and Information Sciences - Papers: Part A

Cooperative communications using the Alamouti space-time block code (STBC) has been mentioned intensively. However, to our knowledge, an in-depth error performance analysis for a space-time coded cooperative communications system, where each node acts as both a source node and a relay node for its partner, has not been reported. Intuitively, cooperative communications would not always be better than direct transmission, but only under certain conditions. This paper first derives an exact performance analysis of the Alamouti STBC cooperative communications for a Binary Phase Shift Keying (BPSK) constellation, which could be extended to a higher density modulation scheme. This mathematical analysis ...


A Phantom Assessment Of Achievable Contouring Concordance Across Multiple Treatment Planning Systems, Elise M. Pogson, Jarrad Begg, Michael Jameson, Claire Dempsey, Drew Latty, Vikneswary Batumalai, Andrew Lim, Kankean Kandasamy, Peter E. Metcalfe, Lois C. Holloway Jan 2015

A Phantom Assessment Of Achievable Contouring Concordance Across Multiple Treatment Planning Systems, Elise M. Pogson, Jarrad Begg, Michael Jameson, Claire Dempsey, Drew Latty, Vikneswary Batumalai, Andrew Lim, Kankean Kandasamy, Peter E. Metcalfe, Lois C. Holloway

Faculty of Engineering and Information Sciences - Papers: Part A

In this paper, the highest level of inter- and intra-observer conformity achievable with different treatment planning systems (TPSs), contouring tools, shapes, and sites have been established for metrics including the Dice similarity coefficient (DICE) and Hausdorff Distance. High conformity values, e.g. DICEBreast_Shape = 0.99 ± 0.01, were achieved. Decreasing image resolution decreased contouring conformity.


Simulink Model For Examining Dynamic Interactions Involving Electro-Mechanical Oscillations In Distribution Systems, Dothinka Ranamuka Rallage, Ashish P. Agalgaonkar, Kashem M. Muttaqi Jan 2015

Simulink Model For Examining Dynamic Interactions Involving Electro-Mechanical Oscillations In Distribution Systems, Dothinka Ranamuka Rallage, Ashish P. Agalgaonkar, Kashem M. Muttaqi

Faculty of Engineering and Information Sciences - Papers: Part A

In Australian medium voltage (MV) distribution networks, the majority of embedded local generation (LG) uses synchronous machine based technology. LG units with a synchronous generator can easily be dispatched and controlled to provide or absorb reactive power and thereby locally supporting the system voltage and increasing the voltage stability margin. The fast response from a synchronous machine based LG unit exciter will ensure fast voltage recovery. This will significantly improve the transient voltage stability. Also, the synchronous machine based LG units can provide inertial support to the system. Furthermore, some of these LG technologies work as standby power supplies all ...


Optimal Design For Energy-Efficient Per-Subcarrier Antenna Selection Mimo–Ofdm Wireless Systems, Ngoc Phuc Le, Le Chung Tran, Farzad Safaei Jan 2015

Optimal Design For Energy-Efficient Per-Subcarrier Antenna Selection Mimo–Ofdm Wireless Systems, Ngoc Phuc Le, Le Chung Tran, Farzad Safaei

Faculty of Engineering and Information Sciences - Papers: Part A

In this paper, we consider a novel optimal design for per-subcarrier antenna selection multi-input multi-output orthogonal frequency division multiplexing systems from an energy-efficiency perspective. The optimal number of antennas, i.e., the number of radio frequency chains, that needs to be built-in on a transmitter to achieve the maximum energy-efficiency is determined. Specifically, an optimization problem for maximizing the average energy-efficiency with respect to the number of antennas is formulated. To solve this optimization problem, we first derive a closed-form formula expressing the cost function (i.e., the average energy-efficiency) as a function of the number of antennas. Search algorithms ...


Energy Efficiency Analysis Of Antenna Selection Multi-Input Multi-Output Automatic Repeat Request Systems Over Nakagami-M Fading Channels, Ngoc Phuc Le, Le Chung Tran, Farzad Safaei, Vineeth Satheeskum Varma Jan 2015

Energy Efficiency Analysis Of Antenna Selection Multi-Input Multi-Output Automatic Repeat Request Systems Over Nakagami-M Fading Channels, Ngoc Phuc Le, Le Chung Tran, Farzad Safaei, Vineeth Satheeskum Varma

Faculty of Engineering and Information Sciences - Papers: Part A

In this study, the authors investigate energy efficiency in antenna selection multi-input multi-output automatic repeat request (MIMO ARQ) wireless systems. The authors first derive an approximate expression for the average frame-error rate (FER) in antenna selection MIMO systems over quasi-static Nakagami-m fading channels. The FER approximation is then used to obtain an analytical expression of an energy-efficiency metric that is defined as the total energy required to successfully deliver one information bit. The authors prove that this energy-efficiency metric is a quasi-convex function with respect to the average signal-to-noise ratio value. Based on this analysis, the authors obtain the optimal ...


Maximising Energy Efficiency In Antenna Selection Mimo Wireless Systems Subject To Qos Constraints, Ngoc Phuc Le, Farzad Safaei, Le Chung Tran Jan 2015

Maximising Energy Efficiency In Antenna Selection Mimo Wireless Systems Subject To Qos Constraints, Ngoc Phuc Le, Farzad Safaei, Le Chung Tran

Faculty of Engineering and Information Sciences - Papers: Part A

Energy-efficiency (EE) in antenna selection multi-input–multi-output (MIMO) systems over Nakagami-m fading channels is investigated. An EE metric is defined as the number of successfully received bits per unit of energy consumption, which takes into account several important system parameters such as channel coding and modulation. An optimisation problem that maximises the EE metric subject to an error-performance constraint is formulated. On the basis of an analysis of this problem, the optimal value of the average energy per transmitted data symbol is obtained, such that the EE in the system is maximised. Simulation results are provided to validate the analysis.


Evaluation Of 3d Gamma Index Calculation Implemented In Two Commercial Dosimetry Systems, Aitang Xing, Sankar Arumugam, Shrikant Deshpande, Armia George, Philip J. Vial, Lois C. Holloway, Gary Goozee Jan 2015

Evaluation Of 3d Gamma Index Calculation Implemented In Two Commercial Dosimetry Systems, Aitang Xing, Sankar Arumugam, Shrikant Deshpande, Armia George, Philip J. Vial, Lois C. Holloway, Gary Goozee

Faculty of Engineering and Information Sciences - Papers: Part A

3D Gamma index is one of the metrics which have been widely used for clinical routine patient specific quality assurance for IMRT, Tomotherapy and VMAT. The algorithms for calculating the 3D Gamma index using global and local methods implemented in two software tools: PTW-VeriSoft (R) r as a part of OCTIVIUS 4D dosimeter systems and 3DVH (TM) from Sun Nuclear were assessed. The Gamma index calculated by the two systems was compared with manual calculated for one data set. The Gamma pass rate calculated by the two systems was compared using 3%/3mm, 2%/2mm, 3%/2mm and 2%/3mm ...


Modeling Minimum Transport Boundary For Fluidized Dense-Phase Pneumatic Conveying Systems, G Setia, Soumya Suddha Mallick, Renhu Pan, Peter W. Wypych Jan 2015

Modeling Minimum Transport Boundary For Fluidized Dense-Phase Pneumatic Conveying Systems, G Setia, Soumya Suddha Mallick, Renhu Pan, Peter W. Wypych

Faculty of Engineering and Information Sciences - Papers: Part A

For the reliable design of fluidized dense-phase pneumatic conveying systems, it is of paramount importance to accurately estimate blockage conditions or the minimum transport boundary. Existing empirical models for the fluidized dense-phase conveying of fine powders are either based on a limited number of products and pipelines or have not been tested for their accuracy and stability over a wide range of scale-up conditions. In this paper, based on the test results of 22 different powders conveyed through 38 pipelines, a unified model for the minimum transport boundary has been developed that represents gas Froude number as a function of ...


A Promising Set Of Spreading Sequences To Mitigate Mai Effects In Mimo Sts Systems, Anh Tuyen Le, Le Chung Tran, Prashan Premaratne, David Stirling, Beata J. Wysocki, Tadeusz A. Wysocki, Peter J. Vial Jan 2015

A Promising Set Of Spreading Sequences To Mitigate Mai Effects In Mimo Sts Systems, Anh Tuyen Le, Le Chung Tran, Prashan Premaratne, David Stirling, Beata J. Wysocki, Tadeusz A. Wysocki, Peter J. Vial

Faculty of Engineering and Information Sciences - Papers: Part A

Multiple input, Multiple output space time spreading (MIMO STS) system is a scheme which can provide full diversity gain without extra resource requirements. However, its performance degrades significantly when multiple access interference (MAI) occurs. In order to mitigate MAI effects, we propose a criterion to build a promising set of combination of spreading sequences for users. Simulation results show that the average BER performance of users using this promising set is about thirty percent lower than that of users using another set in case of 64 chip length Walsh-Hadamard code.


Enhanced Frequency Response Strategy For Pmsg Based Wind Energy Conversion System Using Ultracapacitor In Remote Area Power Supply Systems, Yingjie Tan, Kashem M. Muttaqi Jan 2015

Enhanced Frequency Response Strategy For Pmsg Based Wind Energy Conversion System Using Ultracapacitor In Remote Area Power Supply Systems, Yingjie Tan, Kashem M. Muttaqi

Faculty of Engineering and Information Sciences - Papers: Part A

The high penetration level of wind energy, and non-responsive nature of power electronic interfaced wind energy conversion system (WECS) during frequency variations may create significant stress on conventional generators in a wind-diesel hybrid remote area power supply (RAPS) system. Hence, it is a necessity for WECS to provide frequency support. However, conventional frequency control strategies being used for WECS may impose a severe stress to wind turbines. In this paper, an enhanced frequency response strategy is proposed for the permanent magnet synchronous generator (PMSG) based WECS to regulate RAPS system frequency jointly with its integrated ultracapacitors. The proposed frequency response ...


Optimization Of The Number Of Rays In Interpolation For Light Field Based Free Viewpoint Systems, Hooman Shidanshidi, Farzad Safaei, Wanqing Li Jan 2015

Optimization Of The Number Of Rays In Interpolation For Light Field Based Free Viewpoint Systems, Hooman Shidanshidi, Farzad Safaei, Wanqing Li

Faculty of Engineering and Information Sciences - Papers: Part A

Light field (LF) rendering is widely used in free viewpoint video systems (FVV). Different methods have been proposed to employ depth maps to improve the rendering quality. However, estimation of depth is often error-prone. In this paper, a new method based on the concept of effective sampling density (ESD) is proposed for evaluating the depth-based LF rendering algorithms at different levels of errors in the depth estimation. In addition, for a given rendering quality, we provide an estimation of number of rays required in the interpolation algorithm to compensate for the adverse effect caused by errors in depth maps. The ...


Applications Of Magnetorheological Technology To Semiactive Vibration Control Systems, Miao Yu, Seung-Bok Choi, Norman M. Wereley, Weihua Li, Jeong-Hoi Koo, Xinchun Guan Jan 2015

Applications Of Magnetorheological Technology To Semiactive Vibration Control Systems, Miao Yu, Seung-Bok Choi, Norman M. Wereley, Weihua Li, Jeong-Hoi Koo, Xinchun Guan

Faculty of Engineering and Information Sciences - Papers: Part A

Semiactive vibration control systems possess both the simplicity and inherent reliability of passive systems while maintaining the adaptability of active vibration control systems integrated with an appropriate control algorithm. One of the recent and promising technologies in semiactive vibration control is to utilize magnetorheological (MR) fluids (MRFs) and MR elastomers (MREs). The well-known remarkable feature of MR materials is the continuous controllability of stiffness and damping properties under external magnetic field. The unique controllable characteristic of MR materials has catalyzed comprehensive research and development focusing on vibration control systems including vehicle dampers, engine mounts, adaptive tuned vibration absorber, and seismic ...