http://nova.newcastle.edu.au/vital/access/services/Feed ${session.getAttribute("locale")} 5 http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:8706 Synchronous machines are commonly modelled using d- and q-axis equivalent circuits. Here, we present an approach to the ensuing parameter estimation problem which employs the technique of indirect inference. In indirect inference, an intermediary model is employed which is computed for both the true system and the preferred model, in this case the equivalent circuit model. We have used frequency response data from standard standstill machine tests as the intermediary model. The circuit parameters of the model are optimised, such that the measured difference between the standstill frequency responses of the equivalent circuit model and the true system are minimised. 2013-04-19T00:14:41.919Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:6051 Due to the wide viewer-ship and high commercial potentials, recently, sports video analysis attracts extensive research efforts. One of the main tasks in sports video analysis is to identify sports genres i.e. sports video categorization. Most of the existing work focus on mapping content-based features to sports genres by using supervised learning methods. Moreover, video data sets seeks efficient data reduction methods due to the large size and noisy data. It lacks comparison analysis on the implementation and performance of these methods. In this paper, the research is carried out by using four dominant machine learning algorithms, namely Decision Tree, Support Vector Machine, K Nearest Neighbor and Naive Bayesian, and comparing their performance on a high dimensional feature set which selected by some feature selection tools such as Correlation-based Feature Selection (CFS), Principal Components Analysis (PCA) and Relief. Experimental results shows that Support Vector Machine (SVM) and k-NN are not sensitive to reduction of training sets. Moreover, three different feature reduction methods perform very differently with respect to four different tools. 2013-04-08T03:24:44.919Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:3108 This paper reports on the progress of an industry survey examining the current use of electrical machines and drives in the mining industry. Problems and issues arising out of the current practice are examined. The problems identified include occurrences of mechanical stresses in components leading to failures, power system voltage regulation issues and slow take up and application of new drive technologies. Arguments are presented to ways in which the application of modern AC drives can alleviate many of these problems. 2013-03-03T23:50:11.080Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:8772 This paper presents an automatic liver parenchyma segmentation algorithm that can segment liver in abdominal CT images. There are three major steps in the proposed approach. Firstly, a texture analysis is applied to input abdominal CT images to extract pixel level features. In this step, wavelet coefficients are used as texture descriptors. Secondly, support vector machines (SVMs) are implemented to classify the data into pixel-wised liver area or non-liver area. Finally, integrated morphological operations are designed to remove noise and finally delineate the liver. Our unique contributions to liver segmentation are twofold: one is that it has been proved through experiments that wavelet features present good classification result when SVMs are used; the other is that the combination of morphological operations with the pixel-wised SVM classifier can delineate volumetric liver accurately. The algorithm can be used in an advanced computer-aided liver disease diagnosis and liver surgical planning system. Examples of applying the proposed algorithm on real CT data are presented with performance validation based on the comparison between the automatically segmented results and manually segmented ones. 2013-02-20T04:00:36.538Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:2152 This paper investigates the use of an imaginary power based speed estimation algorithm for induction machines. The algorithm investigated was first proposed by Peng and Fukao in 1994, and has some very desirable characteristics such as insensitivity to knowledge of stator resistance, and does not use pure integrations. However, it has been shown that the algorithm does not operate stably under regeneration conditions, which has been the main reason that it has not seen much application. This paper investigates the reasons behind this instability, and then develops a solution approach. 2013-02-19T02:20:08.474Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:11533 A companion paper provided the theoretical basis for a comparison between phase shifted carrier and space vector modulation schemes. This paper utilises the analysis techniques developed to investigate some non-ideal implementation aspects of the modulation strategies as well as the effect of increasing the level number on the performance of the cascaded H-bridge static compensator (H-StatCom). Specifically, non-ideal elements of the modulation scheme, such as non-uniform DC bus voltages, carrier phase-shift error and transient capacitor voltages are discussed. Simulation results are presented which show that there is an important relationship between the performance of the phase shifted carrier technique and the number of levels in the H-StatCom. 2013-02-19T00:33:23.204Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:11603 DC machines continue to be widely used in many applications including mining. No comprehensive condition monitoring tools for large industrial DC machines are available on the market. The authors of this paper are involved in a research project supported by industry partners, which primary objective is to develop a DC Motor Duty meter envisaged as a predictive online condition monitoring tool for DC machines used in digging applications. Test facility constructed within this project and instrumentation of the motors were described in the previous year paper. This paper focuses on the analysis of experimental data obtained in steady state at different loading and speed. After initial evaluation of the machine steady state performance, spectral characteristics of the experimentally obtained armature current, armature voltage, flux density under the main pole and flux density in the commutation zone are developed. Frequency components revealed in the spectra are discussed with relation to their cause, role in brush and commutator wear and their importance for the condition monitoring tool development. 2013-02-19T00:10:13.590Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:11671 DC machines continue to be widely used in many applications including mining. No comprehensive condition monitoring tools for large industrial DC machines are available on the market. Recent advances in sensoring, data acquisition and signal processing technologies allow one to obtain real time chracteristics of DC machines directly related to their performance, such as flux density distribution inside the main air gap. This paper is based on a research project sponsored by industry partners that included construction of a test facility and an extensive experimental program with a view of development of a condition monitoring tool. The paper explains about the motor instrumentation, facility structure and tests performed to date. Based on the experimental results, a number of performance characteristics are derived in the paper including steady state, dynamic and digital drive related characteristics, as described in the paper. The findings of the paper are discussed with their potential application to the condition monitoring tool development. 2013-02-18T23:58:29.367Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:8739 Due to robustness and simplicity of control, DC machines continue to be widely used in many applications including mining. Though a mature technology, DC machines still require research attention to accomodate for heavier loads and harder operation conditions dictated by production needs. Recent advances in sensoring, data acquisition and signal processing technologies allow for direct measurement of quantities that used to be theoretically modeled or indirectly measured in the past. Within a research project with industry partners, the research team obtained the measurements of flux densities inside the motor air gap under both static and dynamic conditions. A variety of valuable information about the motor performance can be derived from these measurements. This paper focuses on one particular aspect of the commutation performance of DC machines, namely, the magnitudes and uniformity of current density through a brush, which to a large degree dictate wear rates of the DC motor commutating group. The paper revisits the classical commutation theory, presents a mathematical model for current density estimation across a brush, and applies this model to the experimental results obtained. The results are then discussed and related to the commutation quality of the machine. 2013-02-05T23:31:10.148Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:12222 Research Doctorate - Doctor of Philosophy (PhD) 2012-12-14T05:07:29.537Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:11631 Research Doctorate - Doctor of Philosophy (PhD) 2012-10-15T02:50:07.845Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:1551 Brushless doubly fed induction machines (BDFIMs) have been extensively researched over because of the possibility of using a partially rated inverter in many applications with limited speed variations. However, the special cage rotor construction and substantial rotor losses is one of the key deficiencies of these machines. A similar and extremely interesting machine, the brushless doubly fed reluctance machine (BDFRM), has been largely ignored in comparison. This was mainly due to the fact that reluctance rotor designs were not capable of generating saliency ratios large enough to make the BDFRM competitive with other machines. However, developments in reluctance rotors, spurred on by research into synchronous reluctance machines, have resulted in high-saliency-ratio cageless rotors that are economical to build. This, together with the promise of higher efficiency and simpler control compared to the BDFIM, means that further investigation of the BDFRM is warranted. This paper presents a comparative theoretical analysis and aspects of practical implementation of the important control strategies and associated machine performance/inverter size tradeoffs for the BDFRM in the light of its most likely applications-large-pump-type adjustable-speed drives and variable-speed constant-frequency wind power generation systems. 2012-10-07T23:20:03.252Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:11581 In this paper we propose a multisensor switching strategy for fault tolerant control of rotor wound induction motors operating as stand alone generators. The proposed strategy combines three current sensors and associated observers that estimate the stator flux. The estimates provided by the observers are compared at each sampling time by a switching mechanism, which selects the sensors–observer pair with the smallest error between the estimated flux magnitude and a desired flux reference. The estimates provided by the selected pair are used to implement a vector control law. The switching selection is such that measurements from faulty current sensors are automatically avoided by the switching mechanism, thus maintaining good performance levels even in the presence of a faulty sensor. Simulation results under realistic conditions illustrate the effectiveness of the scheme. 2012-09-21T04:14:08.294Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:10442 Flotation works very well for particles that are typically in the range 20 to 150 μm in diameter, for base metal ores. In this range, it is possible to obtain quite high recoveries in conventional flotation machines. Outside this range, the recoveries decline progressively, whether it is with the very fine or the coarse end of the size spectrum. In this paper, the reasons for the drop-off in recovery are briefly reviewed, together with strategies for future work. Recent progress in the author's laboratory is described. This includes the Concorde CellTM, which takes advantage of the high dissipation rates in the shock wave created when a gas-liquid mixture reaches supersonic velocities. The environment thus created is very beneficial for the flotation of ultra-fines. For coarse particles, the reasons for the drop-off in recovery can be related to the highly turbulent nature of the pulp in a conventional flotation cell. To improve recovery, it is necessary to find a way of bringing particles and bubbles into contact in a quiescent environment. A new process for coarse particle flotation is described in which a fluidized bed is created in the flotation cell. The flow conditions are very gentle and the high solids concentration leads to rapid rates of capture of the particles. Experimental results are presented. It is apparent that the maximum floatable size for coal and minerals can be increased by a factor of ten over the limits found in current practice. 2012-03-19T05:00:07.445Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:7863 Current approaches to facial expression classification employ a variety of expression classes and different preprocessing steps, making comparison of results difficult. To outline the effects of these variations we explore several image and action preprocessing steps, using the discrete expressions: happy, sad, surprised, fearful, angry, disgusted and neutral; with a dataset aligned and normalised by our proposed face model. Each of the preprocessing steps is organised across four prominent approaches: holistic, holistic action, component and component action. These are compared using a modified multiclass Support Vector Machine (SVM) that uses pairwise adaptive model parameters. We illustrate that including the neutral expression as part of the study has a noticeable impact, and suggest that it should be used in future research in this area. We also show that results can be improved through innovative use of image and action preprocessing steps. Our best correct classification rate was 98.33% using 10-fold cross validation and a component action approach. 2012-03-07T22:46:13.857Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:87 We describe experiments in which the sizes of bubbles generated in a flotation cell were measured using high-speed video images. It was observed that in the presence of floatable solids, bubble clusters would form, held together by particles that attach to two or more bubbles and form stable bridges between them. The characteristics of clusters formed in the flotation of silica with dodecylamine (DDA) as collector, are reported. The size of the clusters is found to increase with increasing concentration of collector, probably because of its influence on the hydrophobicity of the silica. The mean size of bubbles within the clusters was generally higher than those that had not aggregated, suggesting that the rate of aggregation increases with increasing bubble diameter. The fraction of bubbles that were involved in clusters was found to increase with increasing DDA addition, reaching as high as 68 percent. There was a strong correlation between the fraction in clusters, and published values of the contact angle of DDA solutions and quartz. Previously unpublished photographs of bubble clusters rising out of industrial flotation cells are presented, that provide further evidence of cluster formation. The mechanics of cluster formation are discussed, and the implications for the modelling of the flotation process, and the performance of flotation cells, are explored. Clusters would be expected to lead to increased entrainment of non-floating particles into the froth in industrial cells, resulting in reduced product purity or grade. Cluster formation would be expected to increase the flotation recovery of coarse particles. 2012-03-01T01:36:50.556Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:10064 This study describes a new approach for pedestrian behaviour analysis in simulated urban environments. A software system was developed to analyse the dynamics of pedestrians with a focus on their movement trajectories and the angle between the pedestrian's movement vector and their gaze vector. One-class support vector machines and dynamic time warping were applied for outlier detection in order to indentify noticeable changes in the visual behavior of individuals in a group of simulated pedestrians who walk past visually attractive objects. Results of simulation experiments demonstrate how different pedestrian behaviour characteristics can be detected and distinguished in a variety of abstract urban design scenarios. The described software system was designed to allow future real world applications by feeding video recordings of real pedestrians into the model. 2012-02-16T01:40:05.926Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:10033 The theoretical background for flotation kinetics of ultrafine and coarse particles are explored. Recent advances in flotation technology for these difficult areas are reviewed, with a focus on improving the flotation rate of ultrafines, and extending the upper limit for coarse particle flotation. For ultra-fine particles, the theory suggests that the rate of flotation can be improved by increasing the rate of shear in the suspension of particles and bubbles. A new cell has been developed, the Concorde Cell, in which the pre-aerated feed is raised to supersonic velocities before passing into a high-shear zone in the flotation cell. The local dissipation rate is of the order of 100 kW/m³, one to two orders of magnitude higher than is available in conventional mechanical cells. The Concorde Cell has been trialed on a finely ground PGM feed in South Africa, with excellent results. By recycling the tailings, and using the mass pull or solids recovery as the control variable, the Cell is capable of producing a high-grade concentrate at high recoveries, over a wide range of particle sizes. Theory for the upper limit of coarse particle flotation suggests that a quiescent flow field is necessary to prevent the particles from becoming detached from the bubbles. A liquid-fluidized bed provides a suitable environment. The flotation feed is introduced into the fluidized bed, and air bubbles are dispersed in the fluidizing water. Coarse particles attach to the bubbles rising through the bed and are lifted into the froth layer that is maintained on top of the cell in the usual way. Particles of galena up to 1 mm in diameter have been recovered in such a bed, while for particles of lower density such as quartz and coal, the upper limit for flotation has been extended to at least 2 mm and 5.6 mm respectively. The fluidized bed technology provides major advantages beyond the ability to recover coarse particles currently lost in existing operations. Thus, if the upper flotation limit can be extended, the top size for grinding can be raised, with significant reductions in energy costs. Liberation of the values is the key limitation. Also, a fluidized bed flotation cell can accept a feed with much higher percent solids, leading to significant reductions in water requirements. 2012-02-10T04:50:04.605Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:2975 This article addresses the issues of colour classification and collision detection as they occur in the legged league robot soccer environment of RoboCup. We show how the method of one-class classification with support vector machines (SVMs) can be applied to solve these tasks satisfactorily using the limited hardware capacity of the prescribed Sony AIBO quadruped robots. The experimental evaluation shows an improvement over our previous methods of ellipse fitting for colour classification and the statistical approach used for collision detection. 2012-01-30T04:38:36.609Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:9678 Consider the problem of scheduling a set of jobs to be processed exactly once, on any machine of a set of unrelated parallel machines, without preemption. Each job has a due date, weight, and, for each machine, an associated processing time and sequence-dependent setup time. The objective function considered is to minimize the total weighted tardiness of the jobs. This work proposes a non-delayed relax-and-cut algorithm, based on a Lagrangean relaxation of a time indexed formulation of the problem. A Lagrangean heuristic is also developed to obtain approximate solutions. Using the proposed methods, it is possible to obtain optimal solutions within reasonable time for some instances with up to 180 jobs and six machines. For the solutions for which it is not possible to prove optimality, interesting gaps are obtained. 2011-12-09T01:40:06.222Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:8511 Since the time of Plato, the philosophy of objects has had to content with at least three understandings: the ideal, the real and the aesthetic. In the case of things made, god makes the ideal, man makes the real and the artist makes the pictorial representation of the real. In the case of real objects, we can observe that the qualities of the other two objects are implicated if not revealed. This implies that there are transitional spaces between the real and the ideal and between the real and the pictorial. In the transitional space between the real and the art object we can find affect machines. That is, sensory experiences of reception (such as shining and gleaming) that can be found describing and promoting affects. In the transitional space between the real and the ideal we can find the effects of production. That is, the material qualities of real objects more and less approximate a perfect solution to objects as problems: the real chair, in its production, comes closer to or retreats from an ideal chair. The paper falls into two part. The first is a philosophic investigation into the nature of the making of things. The second part is a phenomenological account of the nature and uses of affects in the reception of objects. In claiming the transitional dimension of reception as a dimension of possible freedom, this paper claims affect machines as foundational to personal sanity and social harmony. 2011-08-02T06:10:04.038Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:7862 Support vector machines (SVMs) have been widely adopted for classification, regression and novelty detection. Recent studies (A. Ben-Hur et al., 2001) proposed to employ them for cluster analysis too. The basis of this support vector clustering (SVC) is density estimation through SVM training. SVC is a boundary-based clustering method, where the support information is used to construct cluster boundaries. Despite its ability to deal with outliers, to handle high dimensional data and arbitrary boundaries in data space, there are two problems in the process of cluster labelling. The first problem is its low efficiency when the number of free support vectors increases. The other problem is that it sometimes produces false negatives. We propose a robust cluster assignment method that harvests clustering results efficiently. Our method uses proximity graphs to model the proximity structure of the data. We experimentally analyze and illustrate the performance of this new approach. 2011-06-07T04:40:11.180Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:7780 The two-spiral task is a well-known benchmark for binary classification. The data consist of points on two intertwined spirals which cannot be linearly separated. This article reviews how this task and some of its variations have significantly inspired the development of several important methods in the history of artificial neural networks. The two-spiral task became popular for several different reasons: (1) it was regarded as extremely challenging; (2) it belonged to a suite of standard benchmark tasks; and (3) it had visual appeal and was convenient to use in pilot studies. The article also presents an example which demonstrates how small variations of the two-spiral task such as relative rotations of the two spirals can lead to qualitatively different generalisation results. 2011-05-26T03:10:04.215Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:6501 Field Oriented Control (FOC) and more recently Direct Torque Control (DTC) have been the algorithms of choice for high performance induction machine drive systems. Recently a different algorithm based on the concept of controlling the real and imaginary powers in the machine has been proposed. This algorithm is called Instantaneous Power Control (IPC). This paper presents a brief outline of the IPC algorithm, and then will, via simulation and experiment, examine the robustness of IPC to parameter variations. The transient performance of IPC and FOC are experimentally determined under similar parameter uncertainty. The low speed operating limit of IPC is investigated when a phase locked loop based back-emf estimation techniqued is utilised. 2010-06-15T05:00:04.983Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:2589 Natural field orientation (NFO) is a technique for generating a rotating reference frame position for an induction machine which is aligned with the stator flux. The term "natural" is applied because there is an implicit tendency for the rotating frame to realign with the correct stator flux frame position if there is a perturbation away from this position. However, under regeneration conditions this realignment property may not occur, and the frame position, if perturbed, will move the control reference frame away from stator flux alignment. This paper examines this frame alignment stability problem, and proposes a solution that retains the essential simplicity of the NFO concept. 2010-05-13T04:30:01.847Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:6155 This interdisciplinary study proposes a method for architectural design analysis of house façades which is based on face detection and facial expression classification. The hypothesis is that abstract face expression features can occur in the architectural design of house façades and will potentially trigger emotional responses of observers. The approach used statistical learning with support vector machines for classification. In the computer experiments the system was trained using a specifically composed image data base consisting of human faces and smileys. Afterwards it was applied to a series of test images of human facial expressions and house façades. The experiments show how facial expression pattern associated with emotional states such as surprise, fear, happiness, sadness, anger, disgust, contempt or neutral could be recognised in both image data sets. 2010-05-07T05:00:17.894Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:2632 This paper presents a new algorithm for the control of AC machines based on the concept of controlling the instantaneous real and imaginary power. This strategy, called Instantaneous Power Control (IPC), allows decoupled control of the torque and flux in the machine. This paper outlines the basic algorithm and then presents simulation results of its performance. 2010-04-27T07:00:31.342Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:2633 The brushless doubly-fed machine (BDFM) allows the use of a partially rated inverter in many variable speed applications with limited speed variations. In its induction machine form (BDFIM), however, the BDFM has significant rotor losses and poor efficiency due to the cage rotor design. A reluctance version of the BDFM, the brushless doubly-fed reluctance machine (BDFRM), ideally has no rotor losses, and therefore offers the potential for greater efficiency and simpler control compared to the BDFIM. A theoretical study of this interesting machine is very important in order to gain a thorough understanding of its unusual operation, control features and compromises between optimal performance and the size of the inverter and the machine. This paper specifically concentrates on power factor control properties of the machine and trade-offs with other control objectives such as maximum torque per inverter ampere and minimum copper losses. To date this kind of analysis has not appeared in the literature. 2010-04-27T07:00:31.082Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:2592 A comprehensive comparative study of various vector control strategies for the brushless doubly fed reluctance machine (BDFRM) is presented in this paper. Open and closed-loop scalar control algorithms for the machine are developed and examined by computer simulations. Particular emphasis is placed on the machine performance/inverter size trade-offs associated with the control properties considered. Most of this analysis is carried out using normalised modelling techniques specifically focusing on the BDFRM target applications-large pump-type drives and variable speed constant frequency wind-turbine generators. 2010-04-27T06:59:38.269Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:2503 The brushless doubly fed reluctance machine (BDFRM) is related to the better known brushless doubly fed induction machine (BDFIM). Research into doubly fed machines is motivated by the fact that they allow the use of a partially rated inverter in many variable-speed applications. Research into the BDFRM has been largely ignored in comparison to the BDFIM, despite the fact that it has the potential for greater efficiency as compared to the BDFIM, and the rotor is simpler to manufacture. This paper compares the BDFRM and its singly fed cousin, the synchronous reluctance machine. This is a natural comparison since both machines use the same reluctance rotor. The first part of the paper establishes relationships between the inductances of the two machines. This is then used to facilitate a comparison using the constraints that both machines have the same amount of active material, i.e., the same amount of copper and iron, and that the copper losses for both machines are the same. This analysis also allows an approximate comparison with the conventional squirrel-cage induction machine. The analysis is carried out using machine-independent normalizations 2010-04-27T06:49:56.155Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:1553 The brushless doubly fed induction machine (BDFIM) has been extensively researched for approximately 30 years, but a related machine [the brushless doubly fed reluctance machine (BDFRM)], has not. This was mainly due to the fact that reluctance rotor designs were not capable of generating saliency ratios large enough to make the BDFRM competitive with other machines. However, recent developments in reluctance rotors, spurred on by research into synchronous reluctance machines, has resulted in high saliency ratio rotors that are economic to build. This, together with the promise of higher efficiency and simpler control compared to the BDFIM, means that further investigation of the BDFRM is warranted. A relatively limited amount of work to date has been published on the BDFRM. This paper attempts to fill this void by presenting a theoretical analysis of some of the important control properties of the ideal BDFRM. 2010-04-27T06:27:32.275Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:2475 This paper considers a novel model of a single phase, capacitor start induction motor that is based on the use of an ideal rotating transformer (IRTF). The model is an extension of the IRTF based model already used for modelling three phase and DC machines. The paper outlines the new model and discusses an application of the model. A TRIAC is connected in series with the machine as to allow control of the motor speed. Experimental and simulation results of the new model rm the validity of the work carried out. 2010-04-27T06:23:59.289Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:2581 A new high-performance sensorless speed vector controller that implements the maximum torque per ampere control strategy for the inverter-driven synchronous reluctance machine is presented in this paper. It is based on a parameter-dependent technique for online estimation of rotor position and angular velocity at the control rate. The current ripple principle is used to estimate position. The estimates are fed to a conventional closed-loop observer to predict the new position and angular velocity. The very high accuracy of the sensorless control algorithm at both low and high speeds is confirmed by experimental results. 2010-04-27T06:18:01.197Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:2164 In this paper we propose and investigate a new systematic switching control design method applicable to a class of nonlinear discrete time hybrid systems. 2010-04-27T06:12:09.977Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:2161 We propose a systematic switching control design method applicable to a class of piecewise linear hybrid systems. We consider a class of systems controlled by a finite state actuator (i.e. switching controller). For the class of systems considered, precise conditions for stabilizability are unknown. However, by considering the same systems with unknown but bounded exogenous disturbances, we are able to give finitely computable conditions, sufficient for stabilizability without disturbances, yet necessary for stabilizability with disturbances. 2010-04-27T06:12:07.686Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:5621 Sports video has attracted a global viewership. Research effort in this area has been focused on semantic event detection in sports video to facilitate accessing and browsing. Most of the event detection methods in sports video are based on visual features. However, being a significant component of sports video, audio may also play an important role in semantic event detection. In this paper, we have borrowed the concept of the “keyword” from the text mining domain to define a set of specific audio sounds. These specific audio sounds refer to a set of game-specific sounds with strong relationships to the actions of players, referees, commentators, and audience, which are the reference points for interesting sports events. Unlike low-level features, audio keywords can be considered as a mid-level representation, able to facilitate high-level analysis from the semantic concept point of view. Audio keywords are created from low-level audio features with learning by support vector machines. With the help of video shots, the created audio keywords can be used to detect semantic events in sports video by Hidden Markov Model (HMM) learning. Experiments on creating audio keywords and, subsequently, event detection based on audio keywords have been very encouraging. Based on the experimental results, we believe that the audio keyword is an effective representation that is able to achieve satisfying results for event detection in sports video. Application in three sports types demonstrates the practicality of the proposed method. 2010-04-27T04:39:44.329Z ]]>