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Faculty of Engineering and Information Sciences - Papers: Part A

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Full-Text Articles in Engineering

A Decomposition Approach Via Fourier Sine Transform For Valuing American Knock-Out Options With Rebates, Nhat Tan Le, Duy-Minh Dang, Tran Vu Khanh Jan 2017

A Decomposition Approach Via Fourier Sine Transform For Valuing American Knock-Out Options With Rebates, Nhat Tan Le, Duy-Minh Dang, Tran Vu Khanh

Faculty of Engineering and Information Sciences - Papers: Part A

We present an innovative decomposition approach for computing the price and the hedging parameters of American knock-out options with a time-dependent rebate. Our approach is built upon: (i) the Fourier sine transform applied to the partial differential equation with a finite time-dependent spatial domain that governs the option price, and (ii) the decomposition technique that partitions the price of the option into that of the European counterpart and an early exercise premium. Our analytic representations can generalize a number of existing decomposition formulas for some European-style and American-style options. A complexity analysis of the method, together with numerical results, show …


Multivariate Spatial Covariance Models: A Conditional Approach, Noel A. Cressie, Andrew Zammit-Mangion Jan 2016

Multivariate Spatial Covariance Models: A Conditional Approach, Noel A. Cressie, Andrew Zammit-Mangion

Faculty of Engineering and Information Sciences - Papers: Part A

Multivariate geostatistics is based on modelling all covariances between all possible combinations of two or more variables at any sets of locations in a continuously indexed domain. Multivariate spatial covariance models need to be built with care, since any covariance matrix that is derived from such a model must be nonnegative-definite. In this article, we develop a conditional approach for spatial-model construction whose validity conditions are easy to check. We start with bivariate spatial covariance models and go on to demonstrate the approach's connection to multivariate models defined by networks of spatial variables. In some circumstances, such as modelling respiratory …


Vulnerability Analysis Of Hydrological Infrastructure To Flooding In Coastal Cities - A Graph Theory Approach, Robert Ighodaro Ogie, Tomas Holderness, Sarah Dunn, Etienne Turpin Jan 2016

Vulnerability Analysis Of Hydrological Infrastructure To Flooding In Coastal Cities - A Graph Theory Approach, Robert Ighodaro Ogie, Tomas Holderness, Sarah Dunn, Etienne Turpin

Faculty of Engineering and Information Sciences - Papers: Part A

Hydrological infrastructure such as pumps and floodgates are invaluable assets for mitigating flooding in coastal cities. These infrastructure components are often vulnerable to damage or failure due to the impact of flood waters, thus exacerbating the flood hazards and causing significant loss of life and destruction to property worth billions of dollars. Hence, there is a growing need worldwide to enhance the understanding of flood vulnerability and to develop key metrics for assessing it. This study proposes an approach for measuring the vulnerability of hydrological infrastructure to flood damage in coastal cities. In this approach, a hydrological infrastructure flood vulnerability …


A New Approach To Reduce The Expected Energy Not Supplied In A Power Plant Located In A Non-Expandable Transmission System, Hadi Lomei, Danny Sutanto, Kashem M. Muttaqi, Mohsen Assili Jan 2015

A New Approach To Reduce The Expected Energy Not Supplied In A Power Plant Located In A Non-Expandable Transmission System, Hadi Lomei, Danny Sutanto, Kashem M. Muttaqi, Mohsen Assili

Faculty of Engineering and Information Sciences - Papers: Part A

The main objective of most of power plants is to inject power as much as possible into the grid from the power plants. However, the transmission system may restrain the output capability of the power plant, especially, if the power plant is located in an area of non-expandable transmission system. In this situation, any disturbance in the nearby transmission system may force the plant to generate lower than its rated value, which disables it from selling the remaining available generated power to the costumers and also increases the cost of energy not supplied. In this paper, an efficient method is …


A New Approach To Reduce The Non-Linear Characteristics Of A Stressed Power System By Using The Normal Form Technique In The Control Design Of The Excitation System, Hadi Lomei, Danny Sutanto, Kashem M. Muttaqi, Mohsen Assili Jan 2015

A New Approach To Reduce The Non-Linear Characteristics Of A Stressed Power System By Using The Normal Form Technique In The Control Design Of The Excitation System, Hadi Lomei, Danny Sutanto, Kashem M. Muttaqi, Mohsen Assili

Faculty of Engineering and Information Sciences - Papers: Part A

In this paper, a new approach is presented to reduce the nonlinear characteristics of a stressed power system by reducing its second-order modal interaction through retuning some parameters of the generator excitation system. In order to determine the second-order modal interaction of the system, a new index on nonlinearity is developed using normal form theory. Using the proposed index of nonlinearity, a sensitivity function is formed to indicate the most effective excitation system parameters in the nonlinear behavior of the system. These dominant parameters are tuned to reduce the second-order modal interaction of the system and to reduce the index …


A Subspace Projection Approach For Wall Clutter Mitigation In Through-The-Wall Radar Imaging, Fok Hing Chi Tivive, Abdesselam Bouzerdoum, Moeness Amin Jan 2015

A Subspace Projection Approach For Wall Clutter Mitigation In Through-The-Wall Radar Imaging, Fok Hing Chi Tivive, Abdesselam Bouzerdoum, Moeness Amin

Faculty of Engineering and Information Sciences - Papers: Part A

One of the main challenges in through-the-wall radar imaging (TWRI) is the strong exterior wall returns, which tend to obscure indoor stationary targets, rendering target detection and classification difficult, if not impossible. In this paper, an effective wall clutter mitigation approach is proposed for TWRI that does not require knowledge of the background scene nor does it rely on accurate modeling and estimation of wall parameters. The proposed approach is based on the relative strength of the exterior wall returns compared to behind-wall targets. It applies singular value decomposition to the data matrix constructed from the space-frequency measurements to identify …


A New Approach For Classification And Characterization Of Voltage Dips And Swells Using 3d Polarization Ellipse Parameters, Mollah R. Alam, Kashem M. Muttaqi, Abdesselam Bouzerdoum Jan 2015

A New Approach For Classification And Characterization Of Voltage Dips And Swells Using 3d Polarization Ellipse Parameters, Mollah R. Alam, Kashem M. Muttaqi, Abdesselam Bouzerdoum

Faculty of Engineering and Information Sciences - Papers: Part A

This paper presents a new method for classification and characterization of voltage dips and swells in electricity networks. The proposed method exploits unique signatures and parameters of three phase voltage signals extracted from the polarization ellipse in three-dimensional (3D) co-ordinates. Five ellipse parameters, which include azimuthal angle, elevation, tilt, semi-minor axis and semi-major axis, are used to classify and characterize voltage dips and swells. Seven types of voltage dips, which include a total of 19 groups of dips incorporating different kinds of balanced (three-phase dips) and unbalanced (single-phase or double-phase) dips, are identified and successfully classified using the 3D polarization …


Indirect Radio-Chemo-Beta Therapy: A Targeted Approach To Increase Biological Efficiency Of X-Rays Based On Energy, Sianne Oktaria, Stephanie Corde, Michael L. F Lerch, Konstantin K. Konstantinov, Anatoly B. Rosenfeld, Moeava Tehei Jan 2015

Indirect Radio-Chemo-Beta Therapy: A Targeted Approach To Increase Biological Efficiency Of X-Rays Based On Energy, Sianne Oktaria, Stephanie Corde, Michael L. F Lerch, Konstantin K. Konstantinov, Anatoly B. Rosenfeld, Moeava Tehei

Faculty of Engineering and Information Sciences - Papers: Part A

Despite the use of multimodal treatments incorporating surgery, chemotherapy and radiotherapy, local control of gliomas remains a major challenge. The potential of a new treatment approach called indirect radio-chemo-beta therapy using the synergy created by combining methotrexate (MTX) with bromodeoxyuridine (BrUdR) under optimum energy x-ray irradiation is assessed. 9L rat gliosarcoma cells pre-treated with 0.01 μM MTX and/or 10 μM BrUdR were irradiated in vitro with 50 kVp, 125 kVp, 250 kVp, 6 MV and 10 MV x-rays. The cytotoxicity was assessed using clonogenic survival as the radiobiological endpoint. The photon energy with maximum effect was determined using radiation sensitization …


Multi-Phase Variety Trials Using Both Composite And Individual Replicate Samples: A Model-Based Design Approach, Alison B. Smith, David G. Butler, C R. Cavanagh, Brian R. Cullis Jan 2015

Multi-Phase Variety Trials Using Both Composite And Individual Replicate Samples: A Model-Based Design Approach, Alison B. Smith, David G. Butler, C R. Cavanagh, Brian R. Cullis

Faculty of Engineering and Information Sciences - Papers: Part A

The present paper provides an approach for the design and analysis of variety trials that are used to obtain quality trait data. These trials are multi-phase in nature, comprising a field phase followed by one or more laboratory phases. Typically the laboratory phases are costly relative to the field phase and this imposes a limit on the number of samples that can be tested. Historically, this has been achieved by sacrificing field replication, either by testing a single replicate plot for each variety or a single composite sample, obtained by combining material from several field replicates. An efficient statistical analysis …


Multizone Reproduction Of Speech Soundfields: A Perceptually Weighted Approach, Jacob Donley, Christian H. Ritz Jan 2015

Multizone Reproduction Of Speech Soundfields: A Perceptually Weighted Approach, Jacob Donley, Christian H. Ritz

Faculty of Engineering and Information Sciences - Papers: Part A

In this paper a method for the reproduction of multizone speech soundfields using perceptual weighting criteria is proposed. Psychoacoustic models are used to derive a space-time-frequency weighting function to control leakage of perceptually unimportant energy from the bright zone into the quiet zone. This is combined with a method for regulating the number of basis planewaves used in the reproduction to allow for an efficient implementation using a codebook of predetermined weights based on desired soundfield energy in the zones. The approach is capable of improving the mean squared error for reproduced speech in the bright zone by -10.5 decibels. …


A Combined Experimental-Numerical Approach For Determining Mechanical Properties Of Aluminum Subjects To Nanoindentation, Mao Liu, Cheng Lu, A Kiet Tieu, Ching-Tun Peng, Charlie Kong Jan 2015

A Combined Experimental-Numerical Approach For Determining Mechanical Properties Of Aluminum Subjects To Nanoindentation, Mao Liu, Cheng Lu, A Kiet Tieu, Ching-Tun Peng, Charlie Kong

Faculty of Engineering and Information Sciences - Papers: Part A

A crystal plasticity finite element method (CPFEM) model has been developed to investigate the mechanical properties and micro-texture evolution of single-crystal aluminum induced by a sharp Berkovich indenter. The load-displacement curves, pile-up patterns and lattice rotation angles from simulation are consistent with the experimental results. The pile-up phenomenon and lattice rotation have been discussed based on the theory of crystal plasticity. In addition, a polycrystal tensile CPFEM model has been established to explore the relationship between indentation hardness and yield stress. The elastic constraint factor C is slightly larger than conventional value 3 due to the strain hardening.


An Efficient Approach To Dynamically Weighted Multizone Wideband Reproduction Of Speech Soundfields, Jacob Donley, Christian H. Ritz Jan 2015

An Efficient Approach To Dynamically Weighted Multizone Wideband Reproduction Of Speech Soundfields, Jacob Donley, Christian H. Ritz

Faculty of Engineering and Information Sciences - Papers: Part A

This paper proposes and evaluates an efficient approach for practical reproduction of multizone soundfields for speech sources. The reproduction method, based on a previously proposed approach, utilises weighting parameters to control the soundfield reproduced in each zone whilst minimising the number of loudspeakers required. Proposed here is an interpolation scheme for predicting the weighting parameter values of the multizone soundfield model that otherwise requires significant computational effort. It is shown that initial computation time can be reduced by a factor of 1024 with only 85dB of error in the reproduced soundfield relative to reproduction without interpolated weighting parameters. The perceptual …


An Efficient Background Modeling Approach Based On Vehicle Detection, Jia-Yan Wang, Limei Song, Jiangtao Xi, Qinghua Guo Jan 2015

An Efficient Background Modeling Approach Based On Vehicle Detection, Jia-Yan Wang, Limei Song, Jiangtao Xi, Qinghua Guo

Faculty of Engineering and Information Sciences - Papers: Part A

The existing Gaussian Mixture Model(GMM) which is widely used in vehicle detection suffers inefficiency in detecting foreground image during the model phase, because it needs quite a long time to blend the shadows in the background. In order to overcome this problem, an improved method is proposed in this paper. First of all, each frame is divided into several areas(A, B, C and D), Where area A, B, C and D are decided by the frequency and the scale of the vehicle access. For each area, different new learning rate including weight, mean and variance is applied to accelerate the …


Combinatorial Approach Using Wavelet Analysis And Artificial Neural Network For Short-Term Load Forecasting, Dao Hoang Vu, Kashem M. Muttaqi, Ashish P. Agalgaonkar Jan 2014

Combinatorial Approach Using Wavelet Analysis And Artificial Neural Network For Short-Term Load Forecasting, Dao Hoang Vu, Kashem M. Muttaqi, Ashish P. Agalgaonkar

Faculty of Engineering and Information Sciences - Papers: Part A

Short term load forecasting is critically important in modern electricity networks since it helps provide supportive information for reliable power system operation in competitive electricity market environment. In this paper, the wavelet analysis based neural network model is employed to forecast the electricity demand in short-term period. The wavelet analysis helps to decompose the electricity demand data into different frequency bands. The Fourier transform is then employed to reveal the significant lags of these decomposed components. These lags are then used as inputs of neural network model to forecast the future values of each decomposed component. Finally, the forecasted components …


Packet Loss Protection For Interactive Speech Object Rendering: A Multiple Description Approach, Xiguang Zheng, Christian H. Ritz Jan 2014

Packet Loss Protection For Interactive Speech Object Rendering: A Multiple Description Approach, Xiguang Zheng, Christian H. Ritz

Faculty of Engineering and Information Sciences - Papers: Part A

2014 IEEE. This paper investigates the application of novel packet loss protection schemes to compress mixtures of speech sources for interactive real-time audio services such as spatial teleconferencing. Hybrid Forward Error Correction (FEC) and Multiple Description Coding (MDC) packet loss protection techniques are applied to the outputs of a psychoacoustic-based Analysis-By-Synthesis (PABS) coder designed for such applications. The protection approaches split the coder outputs into two descriptions that are separately protected using the hybrid FEC-MDC techniques. Perceptual Evaluation of Speech Quality (PESQ) measurements compare the performance of different protection schemes for a range of typical packet loss conditions. Results indicate …


Emerging Of Academic Information Search System With Ontology-Based Approach, Norasykin Mohd Zaid, Sim Kim Lau Jan 2014

Emerging Of Academic Information Search System With Ontology-Based Approach, Norasykin Mohd Zaid, Sim Kim Lau

Faculty of Engineering and Information Sciences - Papers: Part A

This paper describes the comparison of ontology development tools for development of academic information search system that assists inexperienced research students at a local university in Malaysia to search for academic resources in the local language context (Bahasa Malaysia). The cohort of inexperienced research students faces two main problems when using current system comprises of keyword search. Firstly the language barrier-limiting students' capabilities to conduct keyword search in foreign language (such as English). Secondly limited research experience in querying often results in obtaining irrelevant search results. The proposed semantic search system aims to apply ontology-based search to overcome the above …


A Novel Approach To Mineral Effects On Coke Reactivity, Brian Monaghan, Apsara Jayasekara, Raymond Longbottom Jan 2014

A Novel Approach To Mineral Effects On Coke Reactivity, Brian Monaghan, Apsara Jayasekara, Raymond Longbottom

Faculty of Engineering and Information Sciences - Papers: Part A

A coke analogue has been developed to evaluate mineral effects on coke reactivity. Elucidation of the effects of minerals on coke reactivity has proved difficult due to the complex and heterogeneous nature of industrial coke and the potential non-additive effects of minerals on coke reactivity. The coke analogue addresses this complexity and heterogeneity through control of its mineralogy, porosity and carbon structures. Recent studies have shown the analogue is capable of discriminating individual mineral effects on coke reactivity. In this paper the reaction mechanism of the analogues reactivity in CO2 is assessed and compared with that of industrial coke.


An Algebraic Approach For Determination Of Dg Parameters To Support Voltage Profiles In Radial Distribution Networks, Kashem M. Muttaqi, An D. T Le, Michael Negnevitsky, Gerard Ledwich Jan 2014

An Algebraic Approach For Determination Of Dg Parameters To Support Voltage Profiles In Radial Distribution Networks, Kashem M. Muttaqi, An D. T Le, Michael Negnevitsky, Gerard Ledwich

Faculty of Engineering and Information Sciences - Papers: Part A

Rapidly increasing electricity demands and capacity shortage of transmission and distribution facilities are the main driving forces for the growth of Distributed Generation (DG) integration in power grids. One of the reasons for choosing a DG is its ability to support voltage in a distribution system. Selection of effective DG characteristics and DG parameters is a significant concern of distribution system planners to obtain maximum potential benefits from the DG unit. This paper addresses the issue of improving the network voltage profile in distribution systems by installing a DG of the most suitable size, at a suitable location. An analytical …


An Approach For Assessing The Effectiveness Of Multiple-Feature-Based Svm Method For Islanding Detection Of Distributed Generation, Mollah R. Alam, Kashem M. Muttaqi, Abdesselam Bouzerdoum Jan 2014

An Approach For Assessing The Effectiveness Of Multiple-Feature-Based Svm Method For Islanding Detection Of Distributed Generation, Mollah R. Alam, Kashem M. Muttaqi, Abdesselam Bouzerdoum

Faculty of Engineering and Information Sciences - Papers: Part A

Islanding detection is a critical protection issue, as conventional protection schemes such as vector surge (VS) and rate of change of frequency relays do not guarantee islanding detection for all network conditions. Integration of multiple distributed generation (DG) units of different sizes and technologies into distribution grids makes this issue even more critical. This paper presents a comprehensive analysis of the effectiveness of a new method for islanding detection in DG networks. The proposed method, which is based on multiple features and support vector machine (SVM) classification, has the potential to overcome the limitations of conventional protection schemes. The multifeature-based …


Intensity Ratio Approach For 3d Profile Measurement Based On Projection Of Triangular Patterns, Zongkai Yang, Ke Wu, Jiangtao Xi, Yanguang Yu Jan 2014

Intensity Ratio Approach For 3d Profile Measurement Based On Projection Of Triangular Patterns, Zongkai Yang, Ke Wu, Jiangtao Xi, Yanguang Yu

Faculty of Engineering and Information Sciences - Papers: Part A

This paper presents an intensity ratio approach for 3D object profilometry measurement based on projection of triangular patterns. Compared to existing intensity ratio approaches, the proposed one is not influenced by the surface reflectivity and ambient light. Moreover, the proposed intensity ratio is point-by-point-based and thus does not suffer from the influence of surrounding points. The performance of the proposed technique has been tested and the advantages have been demonstrated by experiments. This paper was published in Applied Optics and is made available as an electronic reprint with the permission of OSA. The paper can be found at the following …


A Multifeature-Based Approach For Islanding Detection Of Dg In The Subcritical Region Of Vector Surge Relays, Mollah R. Alam, Kashem M. Muttaqi, Abdesselam Bouzerdoum Jan 2014

A Multifeature-Based Approach For Islanding Detection Of Dg In The Subcritical Region Of Vector Surge Relays, Mollah R. Alam, Kashem M. Muttaqi, Abdesselam Bouzerdoum

Faculty of Engineering and Information Sciences - Papers: Part A

Anti-islanding protection is an important requirement which has to be considered prior to the integration of distributed generation into electricity grids. Conventional vector surge (VS) relays are usually used to detect islanding; however, there is a nondetection zone (NDZ) wherein islanding incidents are undetectable by VS relays. This paper proposes a multifeature-based technique for islanding detection in the subcritical region, defined as a subregion of the NDZ. In the proposed method, features are extracted from five network variables. The extracted features are then used as inputs to a support vector machine to classify the event as islanding or nonislanding. A …


A Novel Approach For Ramp-Rate Control Of Solar Pv Using Energy Storage To Mitigate Output Fluctuations Caused By Cloud Passing, M J. E Alam, K M. Muttaqi, D Sutanto Jan 2014

A Novel Approach For Ramp-Rate Control Of Solar Pv Using Energy Storage To Mitigate Output Fluctuations Caused By Cloud Passing, M J. E Alam, K M. Muttaqi, D Sutanto

Faculty of Engineering and Information Sciences - Papers: Part A

The variability of solar irradiance with a high ramp-rate, caused by cloud passing, can create fluctuation in the PV output. In a weak distribution grid with a high PV penetration, this can create significant voltage fluctuations. Energy storage devices are used to smooth out the fluctuation using traditional moving average control. However, moving average does not control the ramp-rate directly; rather the ramp-rate depends on previous values of PV output. This paper proposes a strategy where the ramp-rate of PV panel output is used to control the PV inverter ramp-rate to a desired level by deploying energy storage (which can …


An Approach For Online Assessment Of Rooftop Solar Pv Impacts On Low-Voltage Distribution Networks, Md Jan-E- Alam, Kashem Muttaqi, Darmawan Sutanto Jan 2014

An Approach For Online Assessment Of Rooftop Solar Pv Impacts On Low-Voltage Distribution Networks, Md Jan-E- Alam, Kashem Muttaqi, Darmawan Sutanto

Faculty of Engineering and Information Sciences - Papers: Part A

Assumption-based offline analysis tools may not be able to provide sufficient and accurate information for the corrective decision making to mitigate solar photovoltaic (PV) impacts in the future distribution grids. This is mainly due to the increasing penetration level of intermittent power generation resources and also the fluctuating behavior of consumer demand. Online assessment tools can assist to manage PV impacts and aid to mitigate those on a real-time basis. This paper proposes an approach for online assessment of rooftop PV impacts on low-voltage (LV) networks using real-time network data. A variable-width sliding window will be used to provide the …


Smoke Detection In Video: An Image Separation Approach, Hongda Tian, Wanqing Li, Lei Wang, Philip Ogunbona Jan 2014

Smoke Detection In Video: An Image Separation Approach, Hongda Tian, Wanqing Li, Lei Wang, Philip Ogunbona

Faculty of Engineering and Information Sciences - Papers: Part A

Existing video-based smoke detection methods often rely on the visual features extracted directly from the original frames. In the case of light smoke, the background is still visible and it deteriorates the quality of the features. This paper presents an approach to separating the smoke component from the background such that visual features can be extracted from the smoke component for reliable smoke detection. Specifically, an image is assumed to be a linear blending of a smoke component and a background image. Given a video frame and its background, the estimation of the blending parameter and the actual smoke component …


Economic-Emission Dispatch Problem: A Semi-Definite Programming Approach, A M. Jubril, O A. Olaniyan, O A. Komolafe, Philip O. Ogunbona Jan 2014

Economic-Emission Dispatch Problem: A Semi-Definite Programming Approach, A M. Jubril, O A. Olaniyan, O A. Komolafe, Philip O. Ogunbona

Faculty of Engineering and Information Sciences - Papers: Part A

A semi-definite programming (SDP) formulation of the multi-objective economic-emission dispatch problem is presented. The fuel cost and emission functions are represented by high order polynomial functions and this was shown to be a more accurate representation of the economic-emission dispatch (EED) problem. Furthermore, the polynomial functions of both objective functions are aggregated into a single objective function using the weighted sum approach. This thus reduces the problem to a standard polynomial optimization problem which was formulated as a hierarchy of semi-definite relaxation problems. The resulting SDP problem was then solved at different degrees of approximation. The performance of the proposed …


An Elementary Approach To C*-Algebras Associated To Topological Graphs, Hui Li, David Pask, Aidan Sims Jan 2014

An Elementary Approach To C*-Algebras Associated To Topological Graphs, Hui Li, David Pask, Aidan Sims

Faculty of Engineering and Information Sciences - Papers: Part A

We develop notions of a representation of a toopological grapph E and of a covariant representation of a topological graph E which do onot require the machinery of C* -correspondences and Cuntz-Pimsner alegebars. We show that the C* -algebra generated by a universal representation of E is isomorphic to the Toeplitz algebra of Katsura's topological-graph bimodule, and that the C* palgebra generated by a universal covariant representation of E is isomorphic to Katsura's topological graph C* -algebra. We exhibit our resluts by constructing the isomorphism between the C* -algebra of the row-finite directed graph E with no sources and the …


Control Of Conducting Polymer Actuators Without Physical Feedback: Simulated Feedback Control Approach With Particle Swarm Optimization, Xingcan Xiang, Rahim Mutlu, Gursel Alici, Weihua Li Jan 2014

Control Of Conducting Polymer Actuators Without Physical Feedback: Simulated Feedback Control Approach With Particle Swarm Optimization, Xingcan Xiang, Rahim Mutlu, Gursel Alici, Weihua Li

Faculty of Engineering and Information Sciences - Papers: Part A

Conducting polymer actuators have shown significant potential in articulating micro instruments, manipulation devices, and robotics. However, implementing a feedback control strategy to enhance their positioning ability and accuracy in any application requires a feedback sensor, which is extremely large in size compared to the size of the actuators. Therefore, this paper proposes a new sensorless control scheme without the use of a position feedback sensor. With the help of the system identification technique and particle swarm optimization, the control scheme, which we call the simulated feedback control system, showed a satisfactory command tracking performance for the conducting polymer actuator's step …


Speech Enhancement With An Acoustic Vector Sensor: An Effective Adaptive Beamforming And Post-Filtering Approach, Yuexian Zou, Peng Wang, Yong Wang, Christian Ritz, Jiangtao Xi Jan 2014

Speech Enhancement With An Acoustic Vector Sensor: An Effective Adaptive Beamforming And Post-Filtering Approach, Yuexian Zou, Peng Wang, Yong Wang, Christian Ritz, Jiangtao Xi

Faculty of Engineering and Information Sciences - Papers: Part A

Speech enhancement has an increasing demand in mobile communications and faces a great challenge in a real ambient noisy environment. This paper develops an effective spatialfrequency domain speech enhancement method with a single acoustic vector sensor (AVS) in conjunction with minimum variance distortionless response (MVDR) spatial filtering and Wiener post-filtering (WPF) techniques. In remote speech applications, the MVDR spatial filtering is effective in suppressing the strong spatial interferences and the Wiener postfiltering is considered as a popular and powerful estimator to further suppress the residual noise if the power spectral density (PSD) of target speech can be estimated properly. With …


A Multiagent Approach For Decentralized Voltage Regulation In Power Distribution Networks Within Dgs, Fenghui Ren, Minjie Zhang, Danny Sutanto Jan 2013

A Multiagent Approach For Decentralized Voltage Regulation In Power Distribution Networks Within Dgs, Fenghui Ren, Minjie Zhang, Danny Sutanto

Faculty of Engineering and Information Sciences - Papers: Part A

Voltage regulation (VR) is a procedure to keep voltages in a distribution network (DN) within normal limits. Conven- tionally, a voltage regulator can read voltage levels from pre- dened measures, and regulate the voltages. However, due to lacking of a distributed generator's (DG) information, the unexpected electricity from a DG will mislead readings on voltages levels, so as to disturb the VR in a DN. Adjust- ing a DG's reactive power output is an alternative way for VR. However, because of limited penetration levels, DGs need to collaborate with other devices in order to provide an eective voltage regulation. Therefore, …


A New Approach To Harmonic Allocation For Medium-Voltage Installations, Victor J. Gosbell, R A. Barr Jan 2013

A New Approach To Harmonic Allocation For Medium-Voltage Installations, Victor J. Gosbell, R A. Barr

Faculty of Engineering and Information Sciences - Papers: Part A

Distributors need to allocate a maximum allowed level of harmonic current to medium-voltage customers to keep voltage distortion acceptable. Tlie paper describes a new approach, based on the concept of voltage droop, requiring much less calculation and data than required by the present approach based on an IEC technical report. The discrepancy between the new method and the present is studied by comparing some carefully selected scenarios. It is shown that the proposed method gives results within 20% of the standards-based approach which makes it a very attractive alternative for harmonic allocation. © Institution of Engineers Australia, 2013.