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Full-Text Articles in Social and Behavioral Sciences

Chandra Observations Of Nuclear Outflows In The Elliptical Galaxy Ngc 4552 In The Virgo Cluster, M Machacek, Paul E. J Nulsen, C Jones, W R. Forman Jan 2006

Chandra Observations Of Nuclear Outflows In The Elliptical Galaxy Ngc 4552 In The Virgo Cluster, M Machacek, Paul E. J Nulsen, C Jones, W R. Forman

Faculty of Engineering and Information Sciences - Papers: Part A

We use a 54.4 ks Chandra observation to study nuclear outflow activity in NGC 4552 (M89), an elliptical galaxy in the Virgo Cluster. Chandra images in the 0.5–2 keV band show two ringlike features ∼1.7 kpc in diameter in the core of NGC 4552, as reported previously by Filho et al. We use spherically symmetric point explosion shock models to argue that the shape of the surface brightness profile across the rims of the rings and the temperature of hot gas in the rings are consistent with a Mach 1.7 shock carrying mean mechanical power Lshock ∼ 3 × 1041 …


Large Amplitude Nematicon Propagation In A Liquid Crystal With Local Response, Catherine Garcia-Reimbert, Antonmaria Minzoni, Noel Smyth, Annette L. Worthy Jan 2006

Large Amplitude Nematicon Propagation In A Liquid Crystal With Local Response, Catherine Garcia-Reimbert, Antonmaria Minzoni, Noel Smyth, Annette L. Worthy

Faculty of Engineering and Information Sciences - Papers: Part A

The evolution of polarized light in a nematic liquid crystal whose directors have a local response to reorienta-tion by the light is analyzed for arbitrary input light power. Approximate equations describing this evolution are derived based on a suitable trial function in a Lagrangian formulation of the basic equations governing the electric fields involved. It is shown that the nonlinearity of the material response is responsible for the forma-tion of solitons, so-called nematicons, by saturating the nonlinearity of the governing nonlinear Schrödinger equation. Therefore in the local material response limit, solitons are formed due to the nonlinear saturation behavior. It …


The Effect Of Small Business Clusters In Prioritising Barriers To E-Commerce Adoption In Regional Smes, Robert Macgregor, Lejla Vrazalic Jan 2006

The Effect Of Small Business Clusters In Prioritising Barriers To E-Commerce Adoption In Regional Smes, Robert Macgregor, Lejla Vrazalic

Faculty of Engineering and Information Sciences - Papers: Part A

This paper presents a study of Swedish regional small businesses which investigated the barriers to E-commerce adoption (amongst other things). The aim of the paper is twofold: to examine the correlation between barriers to E-commerce adoption in order to identify underlying factors: and to determine whether these differ between SMEs that are members of a small business cluster and SMEs that are not. The paper begins by examining the nature of SMEs and identifying features that are unique to SMEs. A discussion of barriers to E-commerce adoption based on previous research is then presented and the barriers are mapped to …


Geant4 Antropomorphic Phantoms, Susanna Guatelli, Barbara Mascialino, Maria Grazia Pia, Witold Pokorski Jan 2006

Geant4 Antropomorphic Phantoms, Susanna Guatelli, Barbara Mascialino, Maria Grazia Pia, Witold Pokorski

Faculty of Engineering and Information Sciences - Papers: Part A

A novel architectural approach to the design of human phantom software models is presented. A detailed design has been developed to enable the adoption of this approach in Geant4-based simulation applications. A few preliminary implementations and application demonstrations are described.


Geant4 Simulation In A Distributed Computing Environment, Susanna Guatelli, Alfonso Mantero, Patricia Mendez Lorenzo, Jakub Moscicki, Maria Grazia Pia Jan 2006

Geant4 Simulation In A Distributed Computing Environment, Susanna Guatelli, Alfonso Mantero, Patricia Mendez Lorenzo, Jakub Moscicki, Maria Grazia Pia

Faculty of Engineering and Information Sciences - Papers: Part A

A general system to perform a Geant4-based simulation in a distributed computing environment is presented. The architecture developed makes the system transparent to sequential or parallel execution and to the environment where the simulation is run: a single machine, a local cluster or a geographically distributed grid.


Experience In The Application Of Iec/Tr 61000-3-6 To Harmonic Allocation In Transmission Systems, T J. Browne, V J. Gosbell, S Perera, D A. Robinson, L M. Falla, P J. Windle, A C. D Perera Jan 2006

Experience In The Application Of Iec/Tr 61000-3-6 To Harmonic Allocation In Transmission Systems, T J. Browne, V J. Gosbell, S Perera, D A. Robinson, L M. Falla, P J. Windle, A C. D Perera

Faculty of Engineering and Information Sciences - Papers: Part A

Technical report IEC/TR 61000-3-6 is widely used as a guide to harmonic management in HV and MV networks, assisting in coordination of harmonic levels between utility and customer. In 2001, Australia and New Zealand adopted the harmonic standard AS/NZS 61000.3.6, which closely follows the above IEC technical report. As a result, transmission utilities and connected loads are required by government regulations to abide by the harmonic allocations set by the standard. The technical report contains some useful general principles which can be applied to the harmonic management of power systems. However, unexpected difficulties can be found when attempts are made …


Hydro-Turbine Governor Control: Theory, Techniques And Limitations, J Culberg, Michael Negnevitsky, Kashem M. Muttaqi Jan 2006

Hydro-Turbine Governor Control: Theory, Techniques And Limitations, J Culberg, Michael Negnevitsky, Kashem M. Muttaqi

Faculty of Engineering and Information Sciences - Papers: Part A

With the entry of Tasmania into the national electricity market, equipment upgrades are required in many parts of the existing power system. This presents an opportunity to embrace new technology, in order to enhance the current efficiency and productivity of the system. One area is that of hydro-turbine speed governors, an integral part of maintaining the frequency of the output. This paper analyses the current standard control algorithm for turbine governors, the PID controller. It illustrates the processes involved, tuning and their limitations. Finally, alternative control systems are discussed.


A Numerical Approach To Evaluate The Fatigue Life Of Monolimb, Nian-Zhong Chen, Winson Lee, Ming Zhang Jan 2006

A Numerical Approach To Evaluate The Fatigue Life Of Monolimb, Nian-Zhong Chen, Winson Lee, Ming Zhang

Faculty of Engineering and Information Sciences - Papers: Part A

Monolimb refers to a transtibial prosthesis with the prosthetic socket and the shank being molded into one piece of thermoplastic material. Shank flexibility of a monolimb can improve gait and comfort. However, fatigue failure of monolimbs under cyclic walking load is an important concern. This study is to evaluate the fatigue life of a monolimb designed for a transtibial amputee, based on finite element analysis, the statistical Miner's rule and reliability analysis. Stress uncertainty due to modeling error and the scatter in fatigue test data were considered. Results indicated that the accuracy of fatigue life evaluation of monolimb depends significantly …


A Robust Design Procedure For Improvement Of Quality Of Lower-Limb Prosthesis, Nian-Zhong Chen, Winson Lee, Ming Zhang Jan 2006

A Robust Design Procedure For Improvement Of Quality Of Lower-Limb Prosthesis, Nian-Zhong Chen, Winson Lee, Ming Zhang

Faculty of Engineering and Information Sciences - Papers: Part A

Lower-limb prostheses are used to restore amputee's walking. Monolimb is one of the designs referring to socket and the shank being molded into one piece of thermoplastic material. Appropriate shank flexibility of a monolimb can improve gait of an amputee. However, during the fabrication, the variations of design variables are inevitably produced which may lead the unexpected shank deflection and directly influence on gait efficiency of an amputee. This paper presents a robust design procedure for improvement of quality of the monolimb by simultaneously minimizing performance variations caused by variations in design variables and bringing the mean value of performance …


Generic Construction Of Hybrid Public Key Traitor Tracing With Full-Public-Traceability, Duong Hieu Phan, Rei Safavi-Naini, Joseph Tonien Jan 2006

Generic Construction Of Hybrid Public Key Traitor Tracing With Full-Public-Traceability, Duong Hieu Phan, Rei Safavi-Naini, Joseph Tonien

Faculty of Engineering and Information Sciences - Papers: Part A

No abstract provided.


An Efficient Single-Key Pirates Tracing Scheme Using Cover-Free Families, Joseph Tonien, Rei Safavi-Naini Jan 2006

An Efficient Single-Key Pirates Tracing Scheme Using Cover-Free Families, Joseph Tonien, Rei Safavi-Naini

Faculty of Engineering and Information Sciences - Papers: Part A

A cover-free family is a well-studied combinatorial structure that has many applications in computer science and cryptography. In this paper, we propose a new public key traitor tracing scheme based on cover-free families. The new traitor tracing scheme is similar to the Boneh-Franklin scheme except that in the Boneh-Franklin scheme, decryption keys are derived from Reed-Solomon codes while in our case they are derived from a cover-free family. This results in much simpler and faster tracing algorithms for single-key pirate decoders, compared to the tracing algorithms of Boneh-Franklin scheme that use Berlekamp- Welch algorithm. Our tracing algorithms never accuse innocent …


Control Stabilisation Of An Islanded System With Dfig Wind Turbine, M Aktarujjaman, Kashem M. Muttaqi, Michael Negnevitsky, Gerard Ledwich Jan 2006

Control Stabilisation Of An Islanded System With Dfig Wind Turbine, M Aktarujjaman, Kashem M. Muttaqi, Michael Negnevitsky, Gerard Ledwich

Faculty of Engineering and Information Sciences - Papers: Part A

Distributed Generation (DG) is often used to export power to the utility system. Loss of main supply can cause a severe loading mismatch between DG generation and load consumption. Consequently, the voltage and frequency of the islanded system will cross the allowable limit. Due to this fact, it is essential to control the voltage and frequency in the islanding mode of operation. In this paper, control stabilisation of an islanded system with a doubly-fed induction generator (DFIG) wind turbine has been addressed. Wind DG produces variable output and is not capable to produce enough reactive power. Hence, it is imperative …


Black Start With Dfig Based Distributed Generation After Major Emergencies, M Aktarujjaman, Kashem M. Muttaqi, Michael Negnevitsky, Gerard Ledwich Jan 2006

Black Start With Dfig Based Distributed Generation After Major Emergencies, M Aktarujjaman, Kashem M. Muttaqi, Michael Negnevitsky, Gerard Ledwich

Faculty of Engineering and Information Sciences - Papers: Part A

Grid connected distributed generation (DG) increases reliability and additional benefits for consumers as well as utilities. The stable and reliable operation of a power system is necessary after major emergencies (or blackouts) following a major system event. Distributed generation may be capable of black start and contribute to fast restoration process at medium to low voltage level. A large scale voltage and frequency excursions may occur during the process of black start with distributed generation due to low inertia and intermittency in power generation. Energy storage integrated with DG can absorb initial impact of central generation and ensure smooth load …


Loading Capabilities Assesment Of Power Transmission Lines, P Hu, Michael Negnevitsky, Kashem M. Muttaqi Jan 2006

Loading Capabilities Assesment Of Power Transmission Lines, P Hu, Michael Negnevitsky, Kashem M. Muttaqi

Faculty of Engineering and Information Sciences - Papers: Part A

This paper reviews the factors that affect the loading capabilities of the transmission line over the short duration. The paper demonstrates how to determine the impact of various parameters on the permissible loading of bare conductors of a power transmission line. Methods for calculating these factors are presented. A sample of a practical application is also included in order to show how these factors affect the loading capabilities of a transmission line.


Distributed Generation For Minimization Of Power Losses In Distribution Systems, Kashem M. Muttaqi, An D. T Le, Michael Negnevitsky, Gerard Ledwich Jan 2006

Distributed Generation For Minimization Of Power Losses In Distribution Systems, Kashem M. Muttaqi, An D. T Le, Michael Negnevitsky, Gerard Ledwich

Faculty of Engineering and Information Sciences - Papers: Part A

Appropriate size and location of distributed generation (DG) play a significant role in minimizing power losses in distribution systems. This paper represents techniques to minimize power losses in a distribution feeder by optimizing DG model in terms of size, location and operating point of DG. Sensitivity analysis for power losses in terms of DG size and DG operating point has been performed. The proposed sensitivity indices can indicate the changes in power losses with respect to DG current injection. The proposed techniques have been developed with considering load characteristics and representing loads with constant impedance and constant current models, separately. …


Validation Of The Geant4 Bremsstrahlung Models: First Results, S Chauvie, S Guatelli, B Mascialino, L Pandola, M G. Pia, P Rodrigues, A Trindade Jan 2006

Validation Of The Geant4 Bremsstrahlung Models: First Results, S Chauvie, S Guatelli, B Mascialino, L Pandola, M G. Pia, P Rodrigues, A Trindade

Faculty of Engineering and Information Sciences - Papers: Part A

A project is in progress for a systematic, rigorous validation of Geant4 electromagnetic physics. This paper presents the first results concerning the validation of Geant4 bremsstrahlung models against experimental data.


Models Of Biological Effects Of Radiation In The Geant4 Toolkit, S Chauvie, Z Francis, S Guatelli, S Incerti, G Montarou, P Nieminen, M G. Pia Jan 2006

Models Of Biological Effects Of Radiation In The Geant4 Toolkit, S Chauvie, Z Francis, S Guatelli, S Incerti, G Montarou, P Nieminen, M G. Pia

Faculty of Engineering and Information Sciences - Papers: Part A

A project, named Geant4-DNA, is in progress to extend the Geant4 simulation toolkit to model the effects of radiation with biological systems at cellular and DNA level. The first component implemented in the first development cycle of the project describes the fractional survival of a population of cells irradiated with photons or charged particles. The software system developed provides the user the option to choose among a small set of alternative models for the calculation of mammalian cell survival after irradiation. The flexible design adopted makes the system open to further extension to implement other cell survival models available in …


Validation Of Geant4 Electromagnetic And Hadronic Models Against Proton Data, G A. P Cirrone, G Cuttone, F Di Rosa, S Guatelli, B Mascialino, M G. Pia, G Russo Jan 2006

Validation Of Geant4 Electromagnetic And Hadronic Models Against Proton Data, G A. P Cirrone, G Cuttone, F Di Rosa, S Guatelli, B Mascialino, M G. Pia, G Russo

Faculty of Engineering and Information Sciences - Papers: Part A

A comprehensive, rigorous validation of Geant4 electromagnetic and hadronic models pertinent to the simulation of the proton Bragg peak in water is presented. Geant4 simulation results are validated against high precision experimental data taken in the CATANA hadrontherapy facility.


Stereoscopic Visualization And Editing Of Automatic Abdominal Aortic Aneurysms (Aaa) Measurements For Stent Graft Planning, Luping Zhou, Yaping Wang, Lin-Chia Goh, Ralf A. Kockro, Luis Serra Jan 2006

Stereoscopic Visualization And Editing Of Automatic Abdominal Aortic Aneurysms (Aaa) Measurements For Stent Graft Planning, Luping Zhou, Yaping Wang, Lin-Chia Goh, Ralf A. Kockro, Luis Serra

Faculty of Engineering and Information Sciences - Papers: Part A

For stent graft selection in the treatment of abdominal aortic aneurysms (AAA) anatomic considerations are important. They determine GO/NO-GO of the treatment and help customize the stent. Current systems for AAA stent insertion planning based on pre-operative CT and MR of the patient do not provide an intuitive interface to view the resulting measurements against the pre-operative CT/MR. Subsequent modifications of the measurements are frequent when automatic algorithms are inaccurate. However, 3D editing is difficult to achieve because of the limitations of monoscopic displays and 2D interface. In this paper, we present a system for automatic AAA measurement and interactive …


Unadulterated Spectral Function Of Low-Energy Quasiparticles In Bi2sr2cacu2o8+Delta, D V. Evtushinsky, A A. Kordyuk, S V. Borisenko, V B. Zabolotnyy, M Knupfer, J Fink, B Büchner, A. V. Pan, A Erb, C T. Lin, H Berger Jan 2006

Unadulterated Spectral Function Of Low-Energy Quasiparticles In Bi2sr2cacu2o8+Delta, D V. Evtushinsky, A A. Kordyuk, S V. Borisenko, V B. Zabolotnyy, M Knupfer, J Fink, B Büchner, A. V. Pan, A Erb, C T. Lin, H Berger

Faculty of Engineering and Information Sciences - Papers: Part A

Fitting the momentum distribution photoemission spectra to the Voigt profile appears to be a robust procedure to purify the interaction effects from the experimental resolution. In application to Bi2Sr2CaCu2O8+delta high-Tc cuprates, the procedure reveals the true scattering rate at low binding energies and temperatures, and consequently, the true value of the elastic scattering. Reaching the minimal value ~16 meV, the elastic scattering does not reveal a systematic dependence on doping level, but is rather sensitive to impurity concentration and can be explained by the forward scattering on out-of-plane impurities. The inelastic scattering is found to form well-defined quasiparticles with the …


On Self Matching In ⌊Nα⌋, Martin W. Bunder Jan 2006

On Self Matching In ⌊Nα⌋, Martin W. Bunder

Faculty of Engineering and Information Sciences - Papers: Part A

For an arbitrary real number with convergents p0 q0 , p1 q1 , p2 q2 , . . ., b(n+qi)c−bnc is equal to pi, and so is independent of n, except at a small specified number of values of n. For fixed n, this relation holds for all or for all except a finite number of values of i.


Spatial Prediction For Massive Datasets, Noel A. Cressie, Gardar Johannesson Jan 2006

Spatial Prediction For Massive Datasets, Noel A. Cressie, Gardar Johannesson

Faculty of Engineering and Information Sciences - Papers: Part A

Remotely sensed spatio-temporal datasets on the order of megabytes to terrabytes are becoming more common. For example, polar-orbiting satellites observe Earth from space, monitoring the Earth's atmospheric, oceanic, and terrestrial processes, and generate massive amounts of environmental data. The current generation of satellites, such as the National Aeronautic and Space Administration's (NASA) Earth Observing System (EOS) Terra and Aqua satellites, generate about 1.5 terrabytes of data per day. In the USA, there are remote-sensing projects in preparation that will dwarf even these datasets. NASA, the National Oceanic and Atmospheric Administration (NOAA), and the Department of Defense (DoD) have created the …


Gait Analysis Of Low-Cost Flexible-Shank Transtibial Prostheses, Winson Lee, Ming Zhang, Peggy Chan, David A. Boone Jan 2006

Gait Analysis Of Low-Cost Flexible-Shank Transtibial Prostheses, Winson Lee, Ming Zhang, Peggy Chan, David A. Boone

Faculty of Engineering and Information Sciences - Papers: Part A

The latest lower-limb prosthetic designs have been incorporated with dynamic elastic response (DER) components to enhance prosthesis flexibility, which are suggested to be beneficial to gait. Although DER prosthetic. feet are preferred by most transtibial amputees and their benefits to gait are supported by some biomechanical studies, many are still utilizing the simple conventional solid ankle cushioned heel (SACH) designs because of the lower cost. The monolimb, a transtibial prosthesis with the socket and the shank molded from a single piece of thermoplastic material, perhaps is an alternative to DER feet for providing flexibility at the shank. In addition to …


Explicit Dynamic Fem Analysis Of Multipass Vertical-Horizontal Rolling, Hai-Liang Yu, Xiang-Hua Liu, Xian-Ming Zhao, Di Wu, Y Kusaba Jan 2006

Explicit Dynamic Fem Analysis Of Multipass Vertical-Horizontal Rolling, Hai-Liang Yu, Xiang-Hua Liu, Xian-Ming Zhao, Di Wu, Y Kusaba

Faculty of Engineering and Information Sciences - Papers: Part A

Three passes of plate rolling during vertical-horizontal rolling process are simulated with explicit dynamic finite element method and updating geometric method. The equivalent strain and stress fields, and shape change at the head and tail of slab during rolling are obtained. The calculated result of the shape at the head and tail of slab is in good agreement with the measured one. The explicit dynamic finite element method and updating geometric method can be used effectively to analyze the multipass vertical-horizontal (V-H) rolling process. © 2006 Central Iron and Steel Research Institute.


Human Visual Perception Of Region Warping Distortions With Different Display And Scene Characteristics, Yang-Wai Chow, Ronald Pose, Matthew Regan, James Phillips Jan 2006

Human Visual Perception Of Region Warping Distortions With Different Display And Scene Characteristics, Yang-Wai Chow, Ronald Pose, Matthew Regan, James Phillips

Faculty of Engineering and Information Sciences - Papers: Part A

This paper presents human visual perception experiment results for a computer graphics rendering technique introduced in ACSC'05. In order to achieve a good immersive virtual reality experience, it is necessary to have at least 60 frames per second to ensure smooth motion. It is also necessary to have low end-to-end latency so that user interaction does not suffer from perceptible delays in images presented to the eyes. The Address Recalculation Pipeline (ARP) architecture reduces end-to-end latency in immersive Head Mounted Display (HMD) virtual reality systems. By using the ARP in conjunction with priority rendering, different sections of the scene are …


Flexural Behaviour Of Hybrid Frp-Concrete-Steel Double Skin Tubular Members, T Yu, Y L. Wong, J G. Teng, S L. Dong, E S.S Lam Jan 2006

Flexural Behaviour Of Hybrid Frp-Concrete-Steel Double Skin Tubular Members, T Yu, Y L. Wong, J G. Teng, S L. Dong, E S.S Lam

Faculty of Engineering and Information Sciences - Papers: Part A

This paper presents the results of an experimental study on the flexural behavior of a new type of hybrid FRP-concrete-steel member as well as results from a corresponding theoretical model based on the plane section assumption and the fiber element approach. This new type of hybrid member is in the form of a double-skin tube, composed of a steel inner tube and an FRP outer tube with a concrete infill between the two tubes, and may be employed as columns or beams. The parameters examined in this study include the section configuration, the concrete strength, and the thicknesses of the …


Jacket Matrices Constructed From Hadamard Matrices And Generalized Hadamard Matrices, Ken Finlayson, Moon Ho Lee, Jennifer Seberry, Mieko Yamada Jan 2006

Jacket Matrices Constructed From Hadamard Matrices And Generalized Hadamard Matrices, Ken Finlayson, Moon Ho Lee, Jennifer Seberry, Mieko Yamada

Faculty of Engineering and Information Sciences - Papers: Part A

Jacket matrices constructed from Hadamard matrices and generalized Hadamard matrices.


Exel's Crossed Product And Relative Cuntz-Pimsner Algebras, Nathan Brownlowe, Iain Raeburn Jan 2006

Exel's Crossed Product And Relative Cuntz-Pimsner Algebras, Nathan Brownlowe, Iain Raeburn

Faculty of Engineering and Information Sciences - Papers: Part A

We consider Exel's new construction of a crossed product of a $C^*$-algebra $A$ by an endomorphism $\alpha$. We prove that this crossed product is universal for an appropriate family of covariant representations, and we show that it can be realised as a relative Cuntz-Pimsner algbera. We describe a necessary and sufficient condition for the canonical map from $A$ into the crossed product to be injective, and present several examples to demonstrate the scope of this result. We also prove a gauge-invariant uniqueness theorem for the crossed product.


A Dual Graph Construction For Higher-Rank Graphs, And K-Theory For Finite 2-Graphs, Stephen Allen, David Pask, Aidan Sims Jan 2006

A Dual Graph Construction For Higher-Rank Graphs, And K-Theory For Finite 2-Graphs, Stephen Allen, David Pask, Aidan Sims

Faculty of Engineering and Information Sciences - Papers: Part A

Given a k-graph Λ and an element p of Nk, we define the dual k-graph, pΛ. We show that when Λ is row-finite and has no sources, the C*-algebras C*(Λ) and C*(pΛ) coincide. We use this isomorphism to apply Robertson and Steger's results to calculate the K-theory of C*(Λ) when Λ is finite and strongly connected and satisfies the aperiodicity condition.


An Agent-Oriented Approach To Change Propagation In Software Evolution, Khanh Hoa Dam, Michael Winikoff, Lin Padgham Jan 2006

An Agent-Oriented Approach To Change Propagation In Software Evolution, Khanh Hoa Dam, Michael Winikoff, Lin Padgham

Faculty of Engineering and Information Sciences - Papers: Part A

Software maintenance and evolution are inevitable activities since almost all software that is useful and successful stimulates user-generated requests for change and improvements. One of the most critical problems in software maintenance and evolution is to maintain consistency between software artefacts by propagating changes correctly. Although many approaches have been proposed, automated change propagation is still a significant technical challenge in software engineering. In this paper we present a novel, agent-oriented approach to deal with change propagation in evolving software systems that are developed using the Prometheus methodology. A metamodel with a set of the Object Constraint Language (OCL) rules …