Social and Behavioral Sciences Commons^™

A Scalable Algorithm For Learning A Mahalanobis Distance Metric, Junae Kim, Chunhua Shen, Lei Wang

Faculty of Engineering and Information Sciences - Papers: Part A

A distance metric that can accurately re°ect the intrinsic characteristics of data is critical for visual recognition tasks. An e®ective solution to de¯ning such a metric is to learn it from a set of training sam- ples. In this work, we propose a fast and scalable algorithm to learn a Ma- halanobis distance. By employing the principle of margin maximization to secure better generalization performances, this algorithm formulates the metric learning as a convex optimization problem with a positive semide¯nite (psd) matrix variable. Based on an important theorem that a psd matrix with trace of one can always be represented …

A Multi-Resolution Approach To Learning With Overlapping Communities, Lei Tang, Xufei Wang, Huan Liu, Lei Wang

Faculty of Engineering and Information Sciences - Papers: Part A

The recent few years have witnessed a rapid surge of par- ticipatory web and social media, enabling a new laboratory for studying human relations and collective behavior on an unprecedented scale. In this work, we attempt to harness the predictive power of social connections to determine the preferences or behaviors of individuals such as whether a user supports a certain political view, whether one likes one product, whether he/she would like to vote for a presidential candidate, etc. Since an actor is likely to participate in mul- tiple dierent communities with each regulating the actor's behavior in varying degrees, and …

Balanced Truncation Of Linear Second-Order Systems: A Hamiltonian Approach, Carsten Hartmann, Valentina-Mira Vulcanov, Christof Schutte

Faculty of Engineering and Information Sciences - Papers: Part A

We present a formal procedure for structure-preserving model reduction of linear second-order and Hamiltonian control problems that appear in a variety of physical contexts, e.g., vibromechanical systems or electrical circuit design. Typical balanced truncation methods that project onto the subspace of the largest Hankel singular values fail to preserve the problem's physical structure and may suffer from lack of stability. In this paper, we adopt the framework of generalized Hamiltonian systems that covers the class of relevant problems and that allows for a generalization of balanced truncation to second-order problems. It turns out that the Hamiltonian structure, stability, and passivity …

On Pogorelov Estimates For Monge-Ampere Type Equations, Jiakun Liu, Neil Trudinger

Faculty of Engineering and Information Sciences - Papers: Part A

In this paper, we prove interior second derivative estimates of Pogorelov type for a general form of Monge-Ampère equation which includes the optimal transportation equation. The estimate extends that in a previous work with Xu-Jia Wang and assumes only that the matrix function in the equation is regular with respect to the gradient variables, that is it satisfies a weak form of the condition introduced previously by Ma,Trudinger and Wang for regularity of optimal transport mappings. We also indicate briefly an application to optimal transportation.

Noncommutative Atiyah-Patodi-Singer Boundary Conditions And Index Pairings In Kk-Theory, Alan L. Carey, John Phillips, Adam C. Rennie

Faculty of Engineering and Information Sciences - Papers: Part A

We investigate an extension of ideas of Atiyah-Patodi-Singer (APS) to a noncommutative geometry setting framed in terms of Kasparov modules. We use a mapping cone construction to relate odd index pairings to even index pairings with APS boundary conditions in the setting of KK-theory, generalising the commutative theory. We find that Cuntz-Krieger systems provide a natural class of examples for our construction and the index pairings coming from APS boundary conditions yield complete K-theoretic information about certain graph C*-algebras

Stabilisation Of An Erodible Soil Using A Chemical Admixture, Jayan S. Vinod, B Indraratna, Md A. Al Mahamud

Faculty of Engineering and Information Sciences - Papers: Part A

Internal erosional behaviour of a lignosulfonate-treated dispersive soil has been studied using apparatus designed and built at University of Wollongong. The effectiveness of lignosulfonate-treated dispersive clay on its erosion resistance has been investigated and its advantages over traditional admixtures (cement) have been presented. Lignosulfonate is a non-toxic admixture that can stabilise certain erodible and dispersive soils effectively, without causing any adverse environmental impact on the ground unlike some traditional stabilisers. Test results show that the erosional parameters such as critical shear stress and coefficient of soil erosion are improved with the increase in the amount of lignosulfonate. Knowledge about the …

Twisted Cyclic Theory And An Index Theory For The Gauge Invariant Kms State On Cuntz Algebras On, Alan L. Carey, John Phillips, Adam C. Rennie

Faculty of Engineering and Information Sciences - Papers: Part A

This paper presents, by example, an index theory appropriate to algebras without trace. Whilst we work exclusively with the Cuntz algebras the exposition is designed to indicate how to develop a general theory. Our main result is an index theorem (formulated in terms of spectral flow) using a twisted cyclic cocycle where the twisting comes from the modular automorphism group for the canonical gauge action on the Cuntz algebra. We introduce a modified K1-group of the Cuntz algebra so as to pair with this twisted cocycle. As a corollary we obtain a noncommutative geometry interpretation for Araki's notion of relative …

Coastal Reservoir In Murray-Darling River And Its Useful Experience For Yellow River, Shu-Qing Yang

Faculty of Engineering and Information Sciences - Papers: Part A

this paper deals with the similarities between the Yellow River Basin and Murray - Darling River Basin. It is found that two of them are facing similar problems, such as water shortage, poor quality for water supply and decreasing runoff etc. Two basins suffer the sharp temporal and spatial variation in water resources, which results in flood threat and water stress alternatively. Consequently these two rivers have attracted global attention due to their significant impacts on their local economical development and ecological system. To alleviate the water stress conditions, this paper investigates the feasibility of coastal reservoirs at the river …

Flicker Mitigation Strategy For Dfigs During Variable Wind Conditions, Lasantha Meegahapola, Brendan Fox, Damian Flynn

Faculty of Engineering and Information Sciences - Papers: Part A

This paper presents a flicker mitigation scheme for the doubly-fed induction generator (DFIG) during variable wind conditions. The flicker mitigation strategy was developed based on the distribution line X/R ratio and the active power deviation from the average active power during variable wind conditions. Flicker emission was analyzed using a flicker meter based on the IEC standards. Both short-term and long-term flicker severities were analyzed during the time period of study. The flicker mitigation strategy was evaluated under different system conditions such as X/R ratio, distribution line length, shortcircuit capacity (SCC), and wind variability. It is shown that the proposed …

Head Pose Estimation Based On Extended Non-Negative Matrix Factorization, Ce Zhan, Wanqing Li, Philip Ogunbona

Faculty of Engineering and Information Sciences - Papers: Part A

One popular solution to head pose estimation is to formulate it as a pattern classication problem, and treat the holistic facial appearance as the input to classiers. However, since the face appearance contains all kinds of information, the variation caused by other factors such as identity, expression and lighting may be larger than that caused by dierent head poses. Thus, the key challenge of these appearance based methods lies in constructing a feature subspace that could successfully recovers head pose while ignoring other sources of image variation. In this paper, following the intuition of combining parts to form a whole …

Compressive Evaluation In Human Motion Tracking, Yifan Lu, Lei Wang, Richard Hartley, Hongdong Li, Dan Xu

Faculty of Engineering and Information Sciences - Papers: Part A

The powerful theory of compressive sensing enables an efficient way to recover sparse or compressible signals from non-adaptive, sub-Nyquist-rate linear measurements. In particular, it has been shown that random projections can well approximate an isometry, provided that the number of linear measurements is no less than twice of the sparsity level of the signal. Inspired by these, we propose a compressive anneal particle filter to exploit sparsity existing in image-based human motion tracking. Instead of performing full signal recovery, we evaluate the observation likelihood directly in the compressive domain of the observed images. Moreover, we introduce a progressive multilevel wavelet …

Computational Intelligence For Carbon-Centric Computing, John Fulcher

Faculty of Engineering and Information Sciences - Papers: Part A

The focus of this paper is twofold: firstly we make a case for the use of Computational Intelligence (CI) techniques in the modelling and/or prediction of global weather, CO2 emissions, climate change and similar endeavours. CI exploits processes found in Nature, albeit by way of software simulations on digital computers (i.e. in silico), and excel in particular at pattern recognition and/or classification. Moreover, they are characterized as being non-algorithmic, bottom-up, data-driven, and learn-by-example. The second focus of this paper is to propose the use of carbonrather than silicon-based computing, specifically in the form of DNA (or molecular) computing. Notwithstanding the …

Liner Shipping Fleet Deployment With Cargo Transshipment And Demand Uncertainty, S Wang, Q Meng

Faculty of Engineering and Information Sciences - Papers: Part A

This paper addresses a novel liner shipping fleet deployment problem characterized by cargo transshipment, multiple container routing options and uncertain demand, with the objective of maximizing the expected profit. This problem is formulated as a stochastic program and solved by the sample average approximation method. In this technique the objective function of the stochastic program is approximated by a sample average estimate derived from a random sample, and then the resulting deterministic program is solved. This process is repeated with different samples to obtain a good candidate solution along with the statistical estimate of its optimality gap. We apply the …

The Ideal Structure Of Reduced Crossed Products, Adam Sierakowski

Faculty of Engineering and Information Sciences - Papers: Part A

Let (A, G) be a C*-dynamical system with G discrete. In this paper we investigate the ideal structure of the reduced crossed product C*-algebra and in particular we determine sufficient—and in some cases also necessary—conditions for A to separate the ideals in A ⋊r G. When A separates the ideals in A ⋊r G, then there is a one-to-one correspondence between the ideals in A ⋊r G and the invariant ideals in A. We extend the concept of topological freeness and present a generalization of the Rokhlin property. Exactness properties of (A, G) turns out to be crucial in these …

Investigation Of High Resolution Compact Gamma Camera Module Based On A Continuous Scintillation Crystal Using A Novel Charge Division Readout Method, Qiu-Sheng Dai, Cui-Lan Zhao, Hualin Zhang, Yujin Qi

Faculty of Engineering and Information Sciences - Papers: Part A

The objective of this study is to investigate a high performance and lower cost compact gamma camera module for a multi-head small animal SPECT system. A compact camera module was developed using a thin Lutetium Oxyorthosilicate (LSO) scintillation crystal slice coupled to a Hamamatsu H8500 position sensitive photomultiplier tube (PSPMT). A two-stage charge division readout board based on a novel sub-tractive resistive readout with a truncated center-of-gravity (TCOG) positioning method was developed for the camera. The performance of the camera was evaluated using a flood 99mTc source with a four-quadrant bar-mask phantom. The preliminary experimental results show that the image …

Development Of A Simplified Readout For A Compact Gamma Camera Based On 2×2 H8500 Multi-Anode Pspmt Array, Yujin Qi, Meng Liu, Xuezhu Zhang, Cuilan Zhao, Jian Song, Hualin Zhang

Faculty of Engineering and Information Sciences - Papers: Part A

The aim of this study was to develop a highperformance simplified readout electronic for a compact gamma camera to achieve a maximized performance in its intrinsic spatial resolution. This compact camera is based on a pixellated NaI(Tl) crystal with 1.2 mm×1.2 mm×5 mm pixel element and 1.4 mm pixel pitch coupled to a 2×2 Hamamatsu H8500 multi-anode position sensitive photomultiplier tube (PSPMT) array. The design of the simplified readout is based on novel two-stage charge divisions with Truncated Center-of-Gravity (TCOG) positioning method to maximize the detector performance. The performance of the compact camera with the novel simplified readout was evaluated …

Gmp‐Based Channel Estimation For Single‐Carrier Transmissions Over Doubly Selective Channels, Qinghua Guo, Defeng (David) Huang

Faculty of Engineering and Information Sciences - Papers: Part A

We present a graph-based channel estimation approach for SC-IFDE (single-carrier transmissions with iterative frequency domain equalization) without CP (cyclic prefix) over doubly selective channels using the recently developed Gaussian message passing (GMP) technique. A direct application of the GMP updating rules in the FFG (Forney-style factor graph) of the SC-IFDE system model incurs high complexity. Approximate updating rules are therefore developed to overcome this problem. The proposed GMP-based channel estimation approach has similar complexity as the low-complexity Kalman-filtering based frequency domain channel estimation approach in the literature, but significantly outperforms the latter due to its enhanced capability in capturing the …

Influence Of Hydrogen Content On Hot Deformation Behavior And Microstructural Evolution Of Ti600 Alloy, J W. Zhao, H Ding, H L. Hou, Z Q. Li

Faculty of Engineering and Information Sciences - Papers: Part A

Isothermal hot compression tests of a Ti600 alloy after hydrogenation were carried out over the temperature range of 760 to 880℃ and strain rate range of 0.01 to 10 s-1. The influence of hydrogen content was studied on the flow stress and activation energy of deformation. The microstructural changes were examined by transmission electron microscopy (TEM). The results show that the addition of 0.3% hydrogen in Ti600 alloy can decrease the hot deformation temperature by 80 ◦C and increase the deformation strain rate by two orders of magnitude. Both the flow stress and activation energy of deformation of Ti600 alloy …

Discriminative Maximum Margin Image Object Categorization With Exact Inference, Qinfeng Shi, Luping Zhou, Li Cheng, Dale Schuurmans

Faculty of Engineering and Information Sciences - Papers: Part A

Categorizing multiple objects in images is essentially a structured prediction problem: the label of an object is in general dependent on the labels of other objects in the image. We explicitly model object dependencies in a sparse graphical topology induced by the adjacency of objects in the image, which benefits inference, and then use maximum margin principle to learn the model discriminatively. Moreover, we propose a novel exact inference method, which is used in training to find the most violated constraint required by cutting plane method. A slightly modified inference method is used in testing when the target labels are …

Mechanism Of Sediment Transport In Uni-Directional, Bi-Directional Flows, Shu-Qing Yang

Faculty of Engineering and Information Sciences - Papers: Part A

The aim of the present study is to investigate the relationship between flow strength and sediment discharge. The appropriate definition of energy dissipation rate E in Bagnold's theorem is discussed and it is found that the sediment transport rate g, in unidirectional and bi-directional flows can be well predicted when E is defined as the product of bed shear stress T. and near bed velocity u. then the linear relationship between u. E and the sediment transport rate is examined using measured data. The good agreement between measured and predicted values indicates that the phenomena of sediment transport can be …

Model Tests On Free-Standing Passive Pile Groups In Sand, Wei-Dong Guo, E. H. Ghee

Faculty of Engineering and Information Sciences - Papers: Part A

A number of tests have been conducted to investigate response of vertically loaded capped pile groups in sand undergoing uniform lateral soil movement. The development of shear force, bending moment and deflection along the piles was measured. Presented in this paper are 4 tests on 2-pile free-standing groups, with a view to establish solutions for predicting the pile response. It was concluded that (1) maximum bending moment Mmax is largely linearly related to the sliding force Tmax in stable and moving layers; (2) The combined impact of pile-cap fixity, soil movement profiles, and axial load may be quantified by a …

Response Of 20 Laterally Loaded Piles In Sand, Wei-Dong Guo, Bi Tang Zhu

Faculty of Engineering and Information Sciences - Papers: Part A

Closed-form solutions and their associated spreadsheet program (GASLFP) were developed by the first author for laterally loaded free- head piles in elastic-plastic media. The solutions show behaviour of a laterally loaded pile is dominated by net limiting force per unit length (LFP) fully mobilised along the pile to a depth called slip depth. They are characterised by three parameters of Ng, α o and n (to describe the LFP) and the soil shear modulus (Gs). Conversely, these parameters may be deduced by matching the predicted with measured response. To facilitate practical design, in this paper, the input values of Ng, …

Comparison Of Thermal Stability In Max211 And 312 Phases, Wei Kong Pang, It-Meng Low, B H. O'Connor, Andrew J. Studer, Vanessa Peterson, Zheng-Ming Sun, J P. Palmquist

Faculty of Engineering and Information Sciences - Papers: Part A

The susceptibility of four MAX phases (Ti2AlC, Cr2AlC, Ti3AlC2, and Ti3SiC2) to high-temperature thermal dissociation in vacuum has been investigated using in-situ neutron diffraction.

Impacts Of Coal Shrinkage, Permeability And Petrography On Gas Regime In Mines Case Study: Tahmoor Coal Mine, Nsw, Australia, Naj Aziz, Ian Porter, F Sereshki

Faculty of Engineering and Information Sciences - Papers: Part A

The volumetric changes in the coal matrix (Coal Shrinkage), permeability under various gas environment conditions as well as perographical properties were studied in the laboratory. The shrinkage and permeability of coal were examined with respect to changing gas type and confining pressures. The shrinkage tests were carried out in high-pressure bombs while the permeability study was conducted in a specially constructed high-pressure chamber. Methane (CH4), carbon dioxide (CO2), nitrogen, (N2) and a 50%-50% volume mixture of CO2/CH4 gas were used in the study. The tests showed that under different pressure levels gas type affected permeability and shrinkage characteristics of coal. …

Thrust And Bending Moment Of Rigid Piles Subjected To Moving Soil, Wei-Dong Guo, H Y. Qin

Faculty of Engineering and Information Sciences - Papers: Part A

An experimental apparatus was developed to investigate the behaviour of vertically loaded free-head piles in sand undergoing lateral soil movement(wf). A large number of tests have been conducted to date. Presented herein are 14 typical model pile tests concerning 2 diameters, 2 vertical pile loading levels, and varying sliding depths with the movement Wf driven by a triangular loading block. The results are provided regarding driving force, and induced shear force (T), bending movement (M) and deflection (y) along the piles with Wf/ normalised sliding depth. The tests enable simple expressions to be proposed, capitalised on theory for laterally loaded …

Organisational Culture And Organisational Impacts Of Information Systems: A Review Of The Empirical Literature, Fei Peng, Rajeev Sharma, Sherah Kurnia, Reeva Lederman, Suelette Dreyfus

Faculty of Engineering and Information Sciences - Papers: Part A

Organisational culture is an important influence in shaping the organisational impacts of Information Systems. However, the conceptualisation and operationalisation of culture in empirical studies does not reflect the richness of the theoretical literature. In particular, our review finds that the dynamic, emergent and reciprocal nature of the IS-culture relationship has not been adequately examined in the empirical literature. This is partly due to the methodologies employed in existing research. Suggestions for enriching empirical research into the ISculture relationship are discussed.

Hippocampal Shape Classification Using Redundancy Constrained Feature Selection, Luping Zhou, Lei Wang, Chunhua Shen, Nick Barnes

Faculty of Engineering and Information Sciences - Papers: Part A

Landmark-based 3D hippocampal shape classification involves high-dimensional descriptor space, many noisy and redundant features, and a very small number of training samples. Feature selection becomes critical in this situation, because it not only improves classification performance, but also identifies the regions that contribute more to shape discrimination. This work identifies the drawbacks of SVM-RFE, and proposes a novel class-separability-based feature selection approach to overcome them. We formulate feature selection as a constrained integer optimization and develop a new algorithm to efficiently and optimally solve this problem. Theoretical analysis and experimental study on both synthetic data and real hippocampus data demonstrate …

Theoretical Expression Of Compressibility Behaviour Of Warp Knitted Spacer Fabrics, Fatemeh Mokhtari, Mahnaz Shamshirsaz, Masoud Latifi, Mohammad Maroufi

Faculty of Engineering and Information Sciences - Papers: Part B

Nowadays, 3-D spacer fabrics characteristics become a highly interested concept for textile researchers. These products have extensive application in automobile, locomotive, aerospace, building and other industries. Several techniques could be applied to produce spacer fabrics using woven, weft and warp knitting technology. Warp knitting is the most commonly used technology for production of spacer fabrics. Spacer fabrics present special characteristics compared to conventional textiles due to their wonderful porous 3-D structures. The compression resistance is a distinct feature beneficial for the structural stability of spacer fabrics, and it is proper to fulfil permanent or instant loading and recovery requirements.

The …

Ultrabroadband Optical Parametric Chirped Pulse Amplifier System For Single-Cycle Waveform Synthesis, Shu-Wei Huang, Giovanni Cirmi, Jeffrey Moses, Kyung-Han Hong, Andrew Benedick, Li-Jin Chen, Enbang Li, Benjamin J. Eggleton, Giulio Cerullo, Franz X. Kartner

Faculty of Engineering and Information Sciences - Papers: Part A

We demonstrate synchronized few-cycle 800-nm and 2-μm pulse trains seeded from a single Ti:sapphire oscillator, able to generate scalable, high-energy pulses lasting less than a single electric-field cycle. Such pulses are attractive for high-field physics.

Simulation Of Macroscopic Deformation Using A Sub-Particle Dem Approach, Leela Kempton, David J. Pinson, Sheng Chew, Paul Zulli, Aibing Yu

Faculty of Engineering and Information Sciences - Papers: Part A

A limitation in numerical modelling of the ironmaking blast furnace is the lack of ability to quantify the effects of particle deformation and subsequent loss of porosity arising from the softening and melting of ferrous materials. Previous attempts to consider deformation focussed solely on the macroscopic effects such as resistance to gas flow, with an assumed decrease in porosity proportional to temperature. Instead, it is proposed to approximate particle scale deformation using a modified subparticle Discrete Element Method approach, where each 'ore' particle is represented using an agglomerate of discrete elements with temperature dependent properties. Cohesive forces binding the agglomerate …