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Articles 1 - 18 of 18
Full-Text Articles in Social and Behavioral Sciences
Nonlinear Dynamical Behavior Of Axially Accelerating Beams: Three-Dimensional Analysis, Mergen H. Ghayesh, Hamed Farokhi
Nonlinear Dynamical Behavior Of Axially Accelerating Beams: Three-Dimensional Analysis, Mergen H. Ghayesh, Hamed Farokhi
Faculty of Engineering and Information Sciences - Papers: Part A
The three-dimensional (3D) nonlinear dynamics of an axially accelerating beam is examined numerically taking into account all of the longitudinal, transverse, and lateral displacements and inertia. Hamilton's principle is employed in order to derive the nonlinear partial differential equations governing the longitudinal, transverse, and lateral motions. These equations are transformed into a set of nonlinear ordinary differential equations by means of the Galerkin discretization technique. The nonlinear global dynamics of the system is then examined by time-integrating the discretized equations of motion. The results are presented in the form of bifurcation diagrams of Poincare maps, time histories, phase-plane portraits, Poincare …
Three-Dimensional Nonlinear Global Dynamics Of Axially Moving Viscoelastic Beams, Hamed Farokhi, Mergen H. Ghayesh, Shahid Hussain
Three-Dimensional Nonlinear Global Dynamics Of Axially Moving Viscoelastic Beams, Hamed Farokhi, Mergen H. Ghayesh, Shahid Hussain
Faculty of Engineering and Information Sciences - Papers: Part A
The three-dimensional nonlinear global dynamics of an axially moving viscoelastic beam is investigated numerically, retaining longitudinal, transverse, and lateral displacements and inertia. The nonlinear continuous model governing the motion of the system is obtained by means of Hamilton's principle. The Galerkin scheme along with suitable eigenfunctions is employed for model reduction. Direct time-integration is conducted upon the reduced-order model yielding the time-varying generalized coordinates. From the time histories of the generalized coordinates, the bifurcation diagrams of Poincaré sections are constructed by varying either the forcing amplitude or the axial speed as the bifurcation parameter. The results for the three-dimensional viscoelastic …
Three Dimensional Dose Verification Of Vmat Plans Using The Octavius 4d Dosimetric System, Sankar Arumugam, Aitang Xing, Tony Young, David Thwaites, Lois C. Holloway
Three Dimensional Dose Verification Of Vmat Plans Using The Octavius 4d Dosimetric System, Sankar Arumugam, Aitang Xing, Tony Young, David Thwaites, Lois C. Holloway
Faculty of Engineering and Information Sciences - Papers: Part A
The Octavius 4D dosimetric system generates a 3D dose matrix based on a measured planar dose and user supplied Percentage Depth Dose (PDD) data. The accuracy of 3D dose matrices reconstructed by the Octavius 4D dosimetric system was systematically studied for an open static field, an open arc field and clinical VMAT plans. The Octavius reconstructed 3D dose matrices were compared with the Treatment Planning System (TPS) calculated 3D dose matrices using 3D gamma (gamma) analysis with 2%/2mm and 3%/3mm tolerance criteria. The larger detector size in the 2D detector array of the Octavius system resulted in failed voxels in …
Dean-Flow-Coupled Elasto-Inertial Three-Dimensional Particle Focusing Under Viscoelastic Flow In A Straight Channel With Asymmetrical Expansion-Contraction Cavity Arrays, Dan Yuan, Jie Zhang, Sheng Yan, Chao Pan, Gursel Alici, Nam-Trung Nguyen, Weihua Li
Dean-Flow-Coupled Elasto-Inertial Three-Dimensional Particle Focusing Under Viscoelastic Flow In A Straight Channel With Asymmetrical Expansion-Contraction Cavity Arrays, Dan Yuan, Jie Zhang, Sheng Yan, Chao Pan, Gursel Alici, Nam-Trung Nguyen, Weihua Li
Faculty of Engineering and Information Sciences - Papers: Part A
In this paper, 3D particle focusing in a straight channel with asymmetrical expansion-contraction cavity arrays (ECCA channel) is achieved by exploiting the dean-flow-coupled elasto-inertial effects. First, the mechanism of particle focusing in both Newtonian and non-Newtonian fluids was introduced. Then particle focusing was demonstrated experimentally in this channel with Newtonian and non- Newtonian fluids using three different sized particles (3.2 lm, 4.8 lm, and 13 lm), respectively. Also, the effects of dean flow (or secondary flow) induced by expansion- contraction cavity arrays were highlighted by comparing the particle distributions in a single straight rectangular channel with that in the ECCA …
Encoding High Dimensional Local Features By Sparse Coding Based Fisher Vectors, Lingqiao Liu, Chunhua Shen, Lei Wang, Anton Van Den Hengel, Chao Wang
Encoding High Dimensional Local Features By Sparse Coding Based Fisher Vectors, Lingqiao Liu, Chunhua Shen, Lei Wang, Anton Van Den Hengel, Chao Wang
Faculty of Engineering and Information Sciences - Papers: Part A
Deriving from the gradient vector of a generative model of local features, Fisher vector coding (FVC) has been identified as an effective coding method for image classification. Most, if not all, FVC implementations employ the Gaussian mixture model (GMM) to characterize the generation process of local features. This choice has shown to be sufficient for traditional low dimensional local features, e.g., SIFT; and typically, good performance can be achieved with only a few hundred Gaussian distributions. However, the same number of Gaussians is insufficient to model the feature space spanned by higher dimensional local features, which have become popular recently. …
A Novel Type Of One-Dimensional Organic Selenium-Containing Fiber With Superior Performance For Lithium-Selenium And Sodium-Selenium Batteries, Hongqiang Wang, Sha Li, Zhixin Chen, Hua-Kun Liu, Zaiping Guo
A Novel Type Of One-Dimensional Organic Selenium-Containing Fiber With Superior Performance For Lithium-Selenium And Sodium-Selenium Batteries, Hongqiang Wang, Sha Li, Zhixin Chen, Hua-Kun Liu, Zaiping Guo
Faculty of Engineering and Information Sciences - Papers: Part A
A novel type of organic selenide fiber composed of carbonized polyacrylonitrile/selenium (CPAN/Se) has been synthesized by heating polyacrylonitrile-selenium (PAN-Se) fibers via the electrospinning technique at 600°C. The Se molecules are confined by N-containing carbon ring structures in the form of energy-storing selenium side chains in the carbonized PAN matrix. This unique stable chemical structure with a conductive carbon skeleton connected to the selenium side chains and excellent mechanical stability can allow CPAN/Se composite cathodes to be charged and discharged in a low-cost carbonate-based electrolyte with excellent long cycle stability and quite good rate performance. The superior electrochemical performance of CPAN/Se …
Three-Dimensional Characterisation Of Particle Size And Shape For Ballast, Yifei Sun, Buddhima Indraratna, Sanjay Nimbalkar Dr
Three-Dimensional Characterisation Of Particle Size And Shape For Ballast, Yifei Sun, Buddhima Indraratna, Sanjay Nimbalkar Dr
Faculty of Engineering and Information Sciences - Papers: Part A
The size and shape of particles influence how effectively coarse angular aggregates of ballast interact. The aim of this study was to improve the characterisation of ballast particles using a threedimensional (3D) imaging method. Various size and shape indices, such as elongation ratio, sphericity and roundness, were determined from the scanned 3D images. A modified index called ‘ellipsoidness’ was proposed to capture adequately the shape of the 3D particles. Variation of these indices with particle size was studied. Comparison of the 3D true sphericity and the corresponding two-dimensional sphericity indicated that the latter would underestimate sphericity. A modified approach for …
Chiral-Like Tunneling Of Electrons In Two-Dimensional Semiconductors With Rashba Spin-Orbit Coupling, Yee Sin Ang, Zhongshui Ma, C Zhang
Chiral-Like Tunneling Of Electrons In Two-Dimensional Semiconductors With Rashba Spin-Orbit Coupling, Yee Sin Ang, Zhongshui Ma, C Zhang
Faculty of Engineering and Information Sciences - Papers: Part A
The unusual tunneling effects of massless chiral fermions (mCF) and massive chiral fermions (MCF) in a single layer graphene and bilayer graphene represent some of the most bizarre quantum transport phenomena in condensed matter system. Here we show that in a two-dimensional semiconductor with Rashba spin-orbit coupling (R2DEG), the real-spin chiral-like tunneling of electrons at normal incidence simultaneously exhibits features of mCF and MCF. The parabolic branch of opposite spin in R2DEG crosses at a Dirac-like point and has a band turning point. These features generate transport properties not found in usual two-dimensional electron gas. Albeit its p Berry phase, …
Free Vibrations Of Interspersed Railway Track Systems In Three-Dimensional Space, Sakdirat Kaewunruen, Alexander Remennikov, Akira Aikawa, Hirotaka Sakai
Free Vibrations Of Interspersed Railway Track Systems In Three-Dimensional Space, Sakdirat Kaewunruen, Alexander Remennikov, Akira Aikawa, Hirotaka Sakai
Faculty of Engineering and Information Sciences - Papers: Part A
Statistically, the actual loading conditions for railway tracks are rather dynamic and transient. The dynamic loadings due to train and track interactions redistribute from the rails to the rail pad, from the rail pad to the railway sleeper, and from the railway sleeper to the underlying ground. Commonly, railway sleeper in track systems is modeled as a beam on elastic foundation. This study makes use of a calibrated finite element model of railway sleepers in a track system, in order to investigate the resonant frequencies and associated mode shapes of railway components in interspersed track systems. The numerical model takes …
A Novel Approach To Investigate Surface Roughness Evolution In Asymmetric Rolling Based On Three Dimensional Real Surface, H Xie, K Manabe, Z Y. Jiang
A Novel Approach To Investigate Surface Roughness Evolution In Asymmetric Rolling Based On Three Dimensional Real Surface, H Xie, K Manabe, Z Y. Jiang
Faculty of Engineering and Information Sciences - Papers: Part A
Surface roughness affects the friction behaviour, stress distribution and surface quality; moreover this influence is more significant when scaling down the strip size. A novel approach has been proposed to investigate the surface roughness in asymmetric rolling based on Finite Element Analysis (FEA). Evolution of asperity flattening, contact area ratio and surface roughness is investigated under various simulation rolling conditions. The model reviewed numerical solutions for real surfaces with asperities of arbitrary shape and varying size and height distributions. The rolling characterization has also been identified for asymmetric rolling. The difference of change in surface roughness for upper and lower …
The Feasibility Study And Characterziation Of A Two-Dimensional Diode Array In “Magic Phantom” For High Dose Rate Brachytherapy Quality Assurance, A Espinoza, B Beeksma, M Petasecca, I Fuduli, C Porumb, D L. Cutajar, S Corde, M A. Jackson, M Lf Lerch, Anatoly B. Rosenfeld
The Feasibility Study And Characterziation Of A Two-Dimensional Diode Array In “Magic Phantom” For High Dose Rate Brachytherapy Quality Assurance, A Espinoza, B Beeksma, M Petasecca, I Fuduli, C Porumb, D L. Cutajar, S Corde, M A. Jackson, M Lf Lerch, Anatoly B. Rosenfeld
Faculty of Engineering and Information Sciences - Papers: Part A
High dose rate (HDR) brachytherapy is a radiation treatment technique capable of delivering large dose rates to the tumor. Radiation is delivered using remote afterloaders to drive highly active sources (commonly 192Ir with an air KERMA strength range between 20 000 and 40 000 U, where 1 U = 1 uGy m2/h in air) through applicators directly into the patient's prescribed region of treatment. Due to the obvious ramifications of incorrect treatment while using such an active source, it is essential that there are methods for quality assurance (QA) that can directly and accurately verify the treatment plan and the …
Energy-Loss Rate Of A Fast Particle In Two-Dimensional Semiconductors With Rashba Spin-Orbit Coupling, Wei Feng, Asya Tawfiq, J.C Cao, Chao Zhang
Energy-Loss Rate Of A Fast Particle In Two-Dimensional Semiconductors With Rashba Spin-Orbit Coupling, Wei Feng, Asya Tawfiq, J.C Cao, Chao Zhang
Faculty of Engineering and Information Sciences - Papers: Part A
The energy-loss rate (ELR) of a charged particle in a two-dimensional semiconductor with Rashba spin-orbit coupling is studied. Our model takes into account of the temperature and density dependence of the electronic properties of the Rashba system. The energy and temperature dependence of the ELR are presented. It is found that a finite Rashba spin-orbit coupling offers a mechanism of tuning the mean scattering time in narrow-gap semiconductors. With a change of Rashba parameter of around 3 times, the mean scattering time can change by one to two orders of magnitude. © 2013 American Institute of Physics.
Three-Dimensional Measurement Of Object Surfaces With Complex Shape And Color Distribution Based On Projection Of Color Fringe Patterns, Ke Chen, Jiangtao Xi, Yanguang Yu, Sheng Tong, Qinghua Guo
Three-Dimensional Measurement Of Object Surfaces With Complex Shape And Color Distribution Based On Projection Of Color Fringe Patterns, Ke Chen, Jiangtao Xi, Yanguang Yu, Sheng Tong, Qinghua Guo
Faculty of Engineering and Information Sciences - Papers: Part A
A challenging issue associated with three-dimensional (3D) fringe patterns profilometry (FPP) is the unwrapping of phase maps resulting from color object surfaces. This paper proposes a new colorprojection-based 3D FPP, making use of the three primary color channels [i.e., red, green, and blue (RGB)] associated with digital projectors. One channel (e.g., red) is used for projecting sinusoidal fringes required by phase shift profilometry (PSP); the other two channels are employed for generating binary stripe patterns. In order to achieve reliable phase unwrapping, each fringe of the sinusoidal patterns is identified by a unique binary sequence. These sequences are then encoded …
A Scalable Unsupervised Feature Merging Approach To Efficient Dimensionality Reduction Of High-Dimensional Visual Data, Lingqiao Liu, Lei Wang
A Scalable Unsupervised Feature Merging Approach To Efficient Dimensionality Reduction Of High-Dimensional Visual Data, Lingqiao Liu, Lei Wang
Faculty of Engineering and Information Sciences - Papers: Part A
To achieve a good trade-off between recognition accuracy and computational efficiency, it is often needed to reduce high-dimensional visual data to medium-dimensional ones. For this task, even applying a simple full-matrix-based linear projection causes significant computation and memory use. When the number of visual data is large, how to efficiently learn such a projection could even become a problem. The recent feature merging approach offers an efficient way to reduce the dimensionality, which only requires a single scan of features to perform reduction. However, existing merging algorithms do not scale well with high-dimensional data, especially in the unsupervised case. To …
A General Compression Approach To Multi-Channel Three-Dimensional Audio, Bin Cheng, Christian Ritz, Ian Burnett, Xiguang Zheng
A General Compression Approach To Multi-Channel Three-Dimensional Audio, Bin Cheng, Christian Ritz, Ian Burnett, Xiguang Zheng
Faculty of Engineering and Information Sciences - Papers: Part A
This paper presents a technique for low bit rate compression of three-dimensional (3D) audio produced by multiple loudspeaker channels. The approach is based on the time-frequency analysis of the localization of spatial sound sources within the 3D space as rendered by a multi-channel audio signal (in this case 16 channels). This analysis results in the derivation of a stereo downmix signal representing the original 16 channels. Alternatively, a mono-downmix signal with side information representing the location of sound sources within the 3D spatial scene can also be derived. The resulting downmix signals are then compressed with a traditional audio coder, …
Three-Dimensional Nonlinear Analysis Of Seismic Ground Response Of Soft Soils In Shanghai, Qingsheng Chen, Guangyun Gao, Junfeng He
Three-Dimensional Nonlinear Analysis Of Seismic Ground Response Of Soft Soils In Shanghai, Qingsheng Chen, Guangyun Gao, Junfeng He
Faculty of Engineering and Information Sciences - Papers: Part A
Reduced order bounding surface model was employed to study 3-D seismic ground response of site considering the nonlinearity of soft soils in Shanghai. A nonlinear procedure for response analysis of horizontal layered sites subjected to multidirectional earthquake loading was used to study vertical and horizontal ground responses, respectively, under unidirectional and multidirectional base excitations (Taft). Also, the development of ratio of vertical and horizontal peak acceleration and the effects of the variation of groundwater table on the characteristics of seismic responses were studied. The study results show that the characteristics of vertical seismic ground response are much different from those …
Specific Yield For A Two-Dimensional Flow, Peter Tritscher, W Wayne Read, Philip Broadbridge
Specific Yield For A Two-Dimensional Flow, Peter Tritscher, W Wayne Read, Philip Broadbridge
Faculty of Engineering and Information Sciences - Papers: Part A
We investigate the systematic secular spatial variation of specific yield. As a vehicle for this analysis we consider a canonical unconfined aquifer consisting of a porous zone whose cross section is a simple long rectangle. The hydraulic conductivity in the unsaturated zone is modeled by the quasi-linear approximation. We find that locally the specific yield may be strongly influenced by the water table depth and mildly dependent on the recharge rate if that rate is high. For the simple geometry considered, a lateral component of flow has been found to have an insignificant effect on the local specific yield and …
A Three-Dimensional Numerical Model Of The Response Of The Australian North West Shelf To Tropical Cyclones, Song-Ping Zhu, Jorg Imberger
A Three-Dimensional Numerical Model Of The Response Of The Australian North West Shelf To Tropical Cyclones, Song-Ping Zhu, Jorg Imberger
Faculty of Engineering and Information Sciences - Papers: Part A
A three-dimensional barotropic and baroclinic model is developed to simulate currents and temperature changes induced by tropical cyclones traversing the continental shelf and slope region of the Australian North West Shelf. The model is based on a layered, explicit, finite difference formulation using the nonlinear primitive equations with an embedded entrainment scheme; a mixed-surface-layer interface is defined, which is allowed to shift from one interface to another, depending on the strength of a storm. The model has been tested by simulating the currents and temperature changes induced by tropical cyclones Orson and Ian. The modelled currents and temperatures agreed well …