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Full-Text Articles in Social and Behavioral Sciences

Impact Of Signaling Schemes On Iterative Linear Minimum-Mean-Square-Error Detection, Li Ping, Jun Tong, Xiaojun Yuan, Qinghua Guo Jan 2008

Impact Of Signaling Schemes On Iterative Linear Minimum-Mean-Square-Error Detection, Li Ping, Jun Tong, Xiaojun Yuan, Qinghua Guo

Faculty of Engineering and Information Sciences - Papers: Part A

In this paper, we study the iterative detection problem for a coded system with multi-ary modulation. We show that, with iterative linear minimum-mean-square-error (LMMSE) detection, superposition coded modulation (SCM) can provide performance superior to that with other traditional signaling schemes used in trellis coded modulation (TCM) and bit-interleaved coded modulation (BICM). This finding provides a useful guideline for system design considering inter-symbol interference (ISI) and other forms of interference. Simulation results are provided to illustrate the efficiency of the iterative LMMSE detection with different signaling schemes. © 2008 IEEE.


Joint Linear Interleaver Design For Concatenated Zigzag Codes, D S. Lin, S Tong, S Q. Li Jan 2008

Joint Linear Interleaver Design For Concatenated Zigzag Codes, D S. Lin, S Tong, S Q. Li

Faculty of Engineering and Information Sciences - Papers: Part A

The design of a class of well-structured low-density parity-check (LDPC) codes, namely linear interleaver based concatenated zigzag (LICZ) codes, is investigated. With summary distances as the design metric, short LICZ codes with large minimum distances can be constructed. Moreover, an efficient cycle-based method is proposed to compute the minimum distances of LICZ codes. Simulation results show that LICZ codes outperform both CZ codes with random interleavers and LDPC codes by the progressive edge growth algorithm.


Study Of The Energy Performance Of Korean Apartment Buildings With Alternative Balcony Configurations, Jo Clarke, Cameron Johnstone, Jaemin Kim, Georgios Kokogiannakis, Paul Strachan, Kyung-Hun Woo, Boo-Sik Kang Jan 2008

Study Of The Energy Performance Of Korean Apartment Buildings With Alternative Balcony Configurations, Jo Clarke, Cameron Johnstone, Jaemin Kim, Georgios Kokogiannakis, Paul Strachan, Kyung-Hun Woo, Boo-Sik Kang

Faculty of Engineering and Information Sciences - Papers: Part A

The purpose of this study is to evaluate the impact of the new regulations design changes on heating loads of apartment buildings and identify the construction configurations (e.g. glazing types, thermal properties, window area ratio, etc.) of the new designs that will ensure the energy performance is at least on the same level as those with a traditional balcony configuration.


Performance Analysis Of Multi-Ary Systems With Iterative Linear Minimum-Mean-Square-Error Detection, Li Ping, Jun Tong, Xiaojun Yuan, Qinghua Guo Jan 2008

Performance Analysis Of Multi-Ary Systems With Iterative Linear Minimum-Mean-Square-Error Detection, Li Ping, Jun Tong, Xiaojun Yuan, Qinghua Guo

Faculty of Engineering and Information Sciences - Papers: Part A

This paper is concerned with coded multi-ary systems over linear channels. Based on a semi-analytical evolution technique, the impact of signaling schemes on the performance of low-cost iterative linear minimum-mean-square-error (LMMSE) detection is studied. It is shown that superposition coded modulation (SCM) maximizes the output signal-to-noise ratio (SNR) of LMMSE detectors. Consequently, SCM may potentially outperform other conventional signaling schemes when LMMSE detectors are used. Numerical examples are provided to verify the theoretical analysis. © 2008 IEEE.


Formal Security Definition And Efficient Construction For Roaming With A Privacy-Preserving Extension, Guomin Yang, Duncan S. Wong, Xiaotie Deng Jan 2008

Formal Security Definition And Efficient Construction For Roaming With A Privacy-Preserving Extension, Guomin Yang, Duncan S. Wong, Xiaotie Deng

Faculty of Engineering and Information Sciences - Papers: Part A

In a secure roaming scenario, a user U travels to a foreign network and communicates with a foreign server V securely so that no one other than U and V can obtain the messages exchanged between them. U may also want to travel anonymously so that no one including V can find out its identity or trace its whereabouts except its home server H. There have been many key establishment protocols proposed for secure roaming. A typical application of these protocols is the mobile roaming service which may be deployed to interconnected WLAN and 3G networks. Despite the importance of …


Reducing Diffusible Hydrogen Contents Of Shielded Metal Arc Welds Through Addition Of Flux-Oxidizing Ingedients, John Du Plessis, Madeleine Du Toit Jan 2008

Reducing Diffusible Hydrogen Contents Of Shielded Metal Arc Welds Through Addition Of Flux-Oxidizing Ingedients, John Du Plessis, Madeleine Du Toit

Faculty of Engineering and Information Sciences - Papers: Part A

This investigation examined the feasibility of using flux modification in the form of the addition of oxidizing ingredients to reduce the as-deposited hydrogen content of basic-type shielded metal arc welds. Additions of up to 16.3% micaceous iron oxide (MIO) to the flux formulation of an E7018-1 type electrode lowered the diffusible weld hydrogen content by approximately 70%. This can be attributed to the formation of oxygen, which lowers the partial pressure of hydrogen in the arc atmosphere, and the reaction of FeO (formed on dissociation of MIO) with hydrogen. The partitioning of deoxidizing elements (manganese and silicon) between the weld …


An Analysis Of The Criteria For Evaluating Adequate Theories Of Computation, Nir Fresco Jan 2008

An Analysis Of The Criteria For Evaluating Adequate Theories Of Computation, Nir Fresco

Faculty of Engineering and Information Sciences - Papers: Part A

This paper deals with the question: What are the criteria that an adequate theory of computation has to meet? (1) Smith's answer: it has to meet the empirical criterion (i.e. doing justice to computational practice), the conceptual criterion (i.e. explaining all the underlying concepts) and the cognitive criterion (i.e. providing solid grounds for computationalism). (2) Piccinini's answer: it has to meet the objectivity criterion (i.e. identifying computation as a matter of fact), the explanation criterion (i.e. explaining the computer's behaviour), the right things compute criterion, the miscomputation criterion (i.e. accounting for malfunctions), the taxonomy criterion (i.e. distinguishing between different classes …


Laterally Loaded Rigid Piles In Cohesionless Soil, Wei-Dong Guo Jan 2008

Laterally Loaded Rigid Piles In Cohesionless Soil, Wei-Dong Guo

Faculty of Engineering and Information Sciences - Papers: Part A

In this paper, limiting force profile for laterally loaded rigid piles in sand and is differentiated from the on-pile force profile, from which elastic-plastic solutions are established and presented in explicity expressioins. Nonlinear responses of the piles are characterized by slip depths mobilized from mudline and the pile-tip. At the states of tip-yield and rotation point yield, expressions for some critical depths are developed, which allow the on-pile force profiles to be constructed. The solutions and the expressions are developed concerning a constant subgrade modulus (k) and a linearly incresing modulus with depth (Gibson k), respectively. capitalized on three measurable …


Two Colour Nonlocal Vector Solitary Waves With Angular Momentum In Nematic Liquid Crystals, Gaetano Assanto, Noel F. Symth, A. L. Worthy Jan 2008

Two Colour Nonlocal Vector Solitary Waves With Angular Momentum In Nematic Liquid Crystals, Gaetano Assanto, Noel F. Symth, A. L. Worthy

Faculty of Engineering and Information Sciences - Papers: Part A

The propagation and interaction of two solitary waves with angular momentum in bulk nematic liquid crystals, termed nematicons, have been studied in the nonlocal limit. These two spinning solitary waves are based on two different wavelengths of light and so are referred to as two-color nematicons. Under suitable boundary conditions, the two nematicons can form a bound state in which they spin about each other. This bound state is found to be stable to the emission of diffractive radiation as the nematicons evolve. In addition this bound state shows walk-off due to dispersion. Using an approximate method based on the …


Shi's Local Estimates, Glen Wheeler Jan 2008

Shi's Local Estimates, Glen Wheeler

Faculty of Engineering and Information Sciences - Papers: Part A

The talk is concerned with some of the analytic results and techniques that are fundamental to the study of the qualitative behavior of solutions of the Ricci flow, later used in singularity analysis. In particular we focus on derivatives estimates, useful for proving long time existence of solutions and obtaining local control of solutions.


Perelman's L-Distrance, V.-M Wheeler Jan 2008

Perelman's L-Distrance, V.-M Wheeler

Faculty of Engineering and Information Sciences - Papers: Part A

This talk is a preparation of the necessary tools for proving the non-collapsing results. The L-length defined by Perelman is the analog of an energy path, but defined in a Riemannian manifold context. The length is used to define the l reduced distance and later on, the reduced volume. So far the properties of the l-length have two applications in the proof of the Poincare conjecture. Associated with the notion of reduced volume, they are used to prove non-collapsing results and also to study the K- solutions.


Monotonicity Of Reduced Volume; Local Non-Collapsing, V.-M Wheeler Jan 2008

Monotonicity Of Reduced Volume; Local Non-Collapsing, V.-M Wheeler

Faculty of Engineering and Information Sciences - Papers: Part A

The talk is divided in two parts. In the first one we give the definition of the reduced volume and by means of reduced length we prove it to be non-increasing in backwards time.


Analysis Of Roll Gap Pressure In Sendzimir Mill By Fem, Hai-Liang Yu, Xiang-Hua Liu, Chao Wang, Hae-Doo Park Jan 2008

Analysis Of Roll Gap Pressure In Sendzimir Mill By Fem, Hai-Liang Yu, Xiang-Hua Liu, Chao Wang, Hae-Doo Park

Faculty of Engineering and Information Sciences - Papers: Part A

The acting force on the roll system of Sendzimir mill was analyzed using 3D FEM. The roll gap pressure distribution and the acting force between rolls S and O, rolls O and I, rolls O and J, rolls I and A, rolls I and B, as well as rolls J and B were analyzed. The results showed that the roll gap pressure mainly affected the roll surface layer, 50 mm for backup rolls the roll gap pressure distribution is of double peaks among the work roll, the 1st intermediate roll (IMR), and the 2nd IMR; the maximum value of the …


Adaboost With Svm-Based Component Classifiers, Xuchun Li, Lei Wang, Eric Sung Jan 2008

Adaboost With Svm-Based Component Classifiers, Xuchun Li, Lei Wang, Eric Sung

Faculty of Engineering and Information Sciences - Papers: Part A

The use of SVM (Support Vector Machine) as component classifier in AdaBoost may seem like going against the grain of the Boosting principle since SVM is not an easy classifier to train. Moreover, Wickramaratna et al. [2001. Performance degradation in boosting. In: Proceedings of the Second International Workshop on Multiple Classifier Systems, pp. 11-21] show that AdaBoost with strong component classifiers is not viable. In this paper, we shall show that AdaBoost incorporating properly designed RBFSVM (SVM with the RBF kernel) component classifiers, which we call AdaBoostSVM, can perform as well as SVM. Furthermore, the proposed AdaBoostSVM demonstrates better generalization …


The Chern Character Of Semifinite Spectral Triples, Alan L. Carey, John Phillips, Adam C. Rennie, Fyodor A. Sukochev Jan 2008

The Chern Character Of Semifinite Spectral Triples, Alan L. Carey, John Phillips, Adam C. Rennie, Fyodor A. Sukochev

Faculty of Engineering and Information Sciences - Papers: Part A

In previous work we generalised both the odd and even local index formula of Connes and Moscovici to the case of spectral triples for a ∗-subalgebra A of a general semifinite von Neumann algebra. Our proofs are novel even in the setting of the original theorem and rely on the introduction of a function valued cocycle (called the resolvent cocycle) which is 'almost' a (b,B)-cocycle in the cyclic cohomology of A. In this paper we show that this resolvent cocycle 'almost' represents the Chern character, and assuming analytic continuation properties for zeta functions, we show that the associated residue cocycle, …


Psdboost: Matrix-Generation Linear Programming For Positive Semidefinite Matrices Learning, Chunhua Shen, Alan Welsh, Lei Wang Jan 2008

Psdboost: Matrix-Generation Linear Programming For Positive Semidefinite Matrices Learning, Chunhua Shen, Alan Welsh, Lei Wang

Faculty of Engineering and Information Sciences - Papers: Part A

In this work, we consider the problem of learning a positive semidefinite matrix. The critical issue is how to preserve positive semidefiniteness during the course of learning. Our algorithm is mainly inspired by LPBoost [1] and the general greedy convex optimization framework of Zhang [2]. We demonstrate the essence of the algorithm, termed PSDBoost (positive semidefinite Boosting), by focusing on a few different applications in machine learning. The proposed PSDBoost algorithm extends traditional Boosting algorithms in that its parameter is a positive semidefinite matrix with trace being one instead of a classifier. PSDBoost is based on the observation that any …


Regularized Discriminative Direction For Shape Difference Analysis, Luping Zhou, Richard Hartley, Lei Wang, Paulette Lieby, Nick Barnes Jan 2008

Regularized Discriminative Direction For Shape Difference Analysis, Luping Zhou, Richard Hartley, Lei Wang, Paulette Lieby, Nick Barnes

Faculty of Engineering and Information Sciences - Papers: Part A

The "discriminative direction" has been proven useful to re- veal the subtle difference between two anatomical shape classes. When a shape moves along this direction, its deformation will best manifest the class difference detected by a kernel classifier. However, we observe that such a direction cannot maintain a shape's "anatomical" correctness, in- troducing spurious difference. To overcome this drawback, we develop a regularized discriminative direction by requiring a shape to conform to its population distribution when it deforms along the discriminative direction. Instead of iterative optimization, an analytic solution is pro- vided to directly work out this direction. Experimental study …


Distributed Generation Diversity Level For Optimal Investment Planning, An D. T Le, M A. Kashem, Michael Negnevitsky, G Ledwich Jan 2008

Distributed Generation Diversity Level For Optimal Investment Planning, An D. T Le, M A. Kashem, Michael Negnevitsky, G Ledwich

Faculty of Engineering and Information Sciences - Papers: Part A

The task of improving the supply quality and maintaining supply continuity during emergencies has become more feasible for a distribution company (DISCO), owing to new developments in Distributed Generation (DG) technologies. Even though the technical issues regarding DG interconnection to the main grid are of great importance and are being addressed by on-going research, it must be clearly placed in the context of on the financial performance of the utility. In this paper, a general approach to quantify the technical benefits of DG employment is proposed. The power system economic impact is assessed by evaluating supply quality, supply reliability, system …


Differential Equations And Asymptotic Solutions For Arithmetic Asian Options: 'Black-Scholes Formulae' For Asian Rate Calls, Jeffrey Dewynne, William Shaw Jan 2008

Differential Equations And Asymptotic Solutions For Arithmetic Asian Options: 'Black-Scholes Formulae' For Asian Rate Calls, Jeffrey Dewynne, William Shaw

Faculty of Engineering and Information Sciences - Papers: Part A

In this article, we present a simplified means of pricing Asian options using partial differential equations (PDEs). We first provide a concise derivation of the well-known similarity reduction and exact Laplace transform solution. We then analyse the problem afresh as a power series in the volatility-scaled contract duration, with a view to obtaining an asymptotic solution for the low-volatility limit, a limit which presents difficulties in the context of the general Laplace transform solution. The problem is approached anew from the point of view of asymptotic expansions and the results are compared with direct, high precision, inversion of the Laplace …


Enhancing Information Flow In A Retail Supply Chain Using Rfid And The Epc Network: A Proof-Of-Concept Approach, Samuel Fosso Wamba, Harold Boeck Jan 2008

Enhancing Information Flow In A Retail Supply Chain Using Rfid And The Epc Network: A Proof-Of-Concept Approach, Samuel Fosso Wamba, Harold Boeck

Faculty of Engineering and Information Sciences - Papers: Part A

RFID technology and the Electronic Product Code (EPC) network have attracted considerable interest from businesses and academics in recent years. The interest is even stronger in the retail industry where firms such as Best Buy, Wal-Mart, Tesco, Target and Metro AG are capitalizing on the potential of these technologies. Based on a field study conducted in a three-layer retail supply chain, this paper tests several scenarios integrating Radio Frequency Identification (RFID) technology and the EPC network and evaluates, in a laboratory setting, their potential as enablers of information flow within a retail supply chain. Using an "open-loop" adoption strategy, our …


Development Of Hydraulic Fracturing In High Stress Conditions In Australian Underground Coal Mines, Dennis John Black, Naj Aziz Jan 2008

Development Of Hydraulic Fracturing In High Stress Conditions In Australian Underground Coal Mines, Dennis John Black, Naj Aziz

Faculty of Engineering and Information Sciences - Papers: Part A

Hydraulic fracturing has been used extensively in the petroleum and coalbed methane industries as a means of improving access to the reservoir and thereby enhancing production. In the Australian coal mining industry there has been an aversion to the use of hydraulic fracturing. One of the main reasons for the lack of application of this technology has been the perceived risk of damage to the strata and the resulting impact on future mining operations. A number of Australian mines are progressing toward areas where gas drainage is becoming increasingly difficult and these mines are seriously considering the use of hydraulic …


A Kernel-Induced Space Selection Approach To Model Selection Of Klda, Lei Wang, Kap Luk Chan, Ping Xue, Luping Zhou Jan 2008

A Kernel-Induced Space Selection Approach To Model Selection Of Klda, Lei Wang, Kap Luk Chan, Ping Xue, Luping Zhou

Faculty of Engineering and Information Sciences - Papers: Part A

Model selection in kernel linear discriminant analysis (KLDA) refers to the selection of appropriate parameters of a kernel function and the regularizer. By following the principle of maximum information preservation, this paper formulates the model selection problem as a problem of selecting an optimal kernel-induced space in which different classes are maximally separated from each other. A scatter-matrix-based criterion is developed to measure the "goodness" of a kernel-induced space, and the kernel parameters are tuned by maximizing this criterion. This criterion is computationally efficient and is differentiable with respect to the kernel parameters. Compared with the leave-one-out (LOO) or -fold …


Orbifolds Are Not Commutative Geometries, Adam C. Rennie, Joseph C. Varilly Jan 2008

Orbifolds Are Not Commutative Geometries, Adam C. Rennie, Joseph C. Varilly

Faculty of Engineering and Information Sciences - Papers: Part A

In this note we show that the crucial orientation condition for commutative geometries fails for the natural commutative spectral triple of an orbifold M/G.


A Low-Complexity Iterative Channel Estimation And Detection Technique For Doubly Selective Channels, Qinghua Guo, Li Ping Jan 2008

A Low-Complexity Iterative Channel Estimation And Detection Technique For Doubly Selective Channels, Qinghua Guo, Li Ping

Faculty of Engineering and Information Sciences - Papers: Part A

In this paper, we propose a low-complexity iterative joint channel estimation, detection and decoding technique for doubly selective channels. The key is a segment-by-segment frequency domain equalization (FDE) strategy under the assumption that channel is approximately static within a short segment. Guard gaps (for cyclic prefixing or zero padding) are not required between adjacent segments, which avoids the power and spectral overheads due to the use of cyclic prefix (CP) in the conventional FDE technique. A low-complexity bi-directional channel estimation algorithm is also developed to exploit correlation information of time-varying channels. Simulation results are provided to demonstrate the efficiency of …


Implementing Analytical Geometric And Penetration Response Correction For Keel-Edge Pinhole Spect Image Reconstruction, Xuezhu Zhang, Qiusheng Dai, Yujin Qi Jan 2008

Implementing Analytical Geometric And Penetration Response Correction For Keel-Edge Pinhole Spect Image Reconstruction, Xuezhu Zhang, Qiusheng Dai, Yujin Qi

Faculty of Engineering and Information Sciences - Papers: Part A

The collimator response compensation is very important in high-resolution pinhole SPECT imaging for resolution recovery and quantitative imaging. In this study the pinhole collimator response of the keel-edge aperture was investigated in terms of the geometric response function and penetration response function (GPRF). An approximate numerical method was proposed to implement the geometric and penetration response correction (GPRC) for keel-edge pinhole SPECT image reconstruction. A lookup table for the GPRC was calculated and then was utilized in the 3D pinhole iterative OSEM reconstruction procedure. The performance of the image reconstruction with the GPRC was evaluated using both the phantom and …


She-Pwm Switching Strategies For Active Neutral Point Clamped Multilevel Converters, Sridhar R. Pulikanti, Mohamed S. A Dahidah, Vassilios G. Agelidis Jan 2008

She-Pwm Switching Strategies For Active Neutral Point Clamped Multilevel Converters, Sridhar R. Pulikanti, Mohamed S. A Dahidah, Vassilios G. Agelidis

Faculty of Engineering and Information Sciences - Papers: Part A

The main drawback of the diode neutral-point-clamped (NPC) converter is the unequal loss distribution among the semiconductor devices which confines the maximum output power and the switching frequency. To address this drawback, switching state redundancy is required to evenly distribute the losses and can be achieved differently as the level of the converter changes. For instance, the three-level active NPC (3L-ANPC) converter has switching state redundancy and is derived from the 3L-NPC converter by adding an anti-parallel switch to the clamping diodes; in the 4L-ANPC converter, the combination of a 2L converter and a 3L-ANPC converter is used; in a …


Berkovich Indentation Of Diamondlike Carbon Coatings On Silicon Substrates, Ayesha J. Haq, Paul Munroe, Mark Hoffman, Phil Martin, Avi Bendavid Jan 2008

Berkovich Indentation Of Diamondlike Carbon Coatings On Silicon Substrates, Ayesha J. Haq, Paul Munroe, Mark Hoffman, Phil Martin, Avi Bendavid

Faculty of Engineering and Information Sciences - Papers: Part A

The deformation behavior of diamondlike carbon (DLC) coatings on silicon substrates induced by Berkovich indentation has been investigated. DLC coatings deposited by a plasma-assisted chemical vapor deposition technique were subjected to nanoindentation with a Berkovich indenter over a range of maximum loads from 100 to 300 mN. Distinct pop-ins were observed for loads greater than 150 mN. However, no pop-out was observed for the loads studied. The top surface of the indents showed annular cracks with associated fragmented material. The cross sections showed up to 20% localized reduction in thickness of the DLC coating beneath the indenter tip. Cracking, {111} …


The Evolution In Coal Mine Gas Extraction - A Response To Economic, Environmental And Community Pressures, Dennis John Black, Naj Aziz Jan 2008

The Evolution In Coal Mine Gas Extraction - A Response To Economic, Environmental And Community Pressures, Dennis John Black, Naj Aziz

Faculty of Engineering and Information Sciences - Papers: Part A

Effective gas management is vital to the success of the longwall mines operating in the Bulli seam, located in the Southern Sydney Basin, Australia. High gas emissions are characteristic of the region with specific gas emissions typically in the order of 30-45 m3/t. The mines that operate in this area have, since 1980, relied on the use of extensive underground to inseam (UIS) drilling to drain gas both ahead of advancing roadway development and following longwall coal extraction. With the ever increasing production capacity of modern mining machinery the UIS methods are struggling to drain sufficient gas from the coal …


Semifinite Spectral Triples Associated With Graph C*-Algebras, Alan L. Carey, John Phillips, Adam Rennie Jan 2008

Semifinite Spectral Triples Associated With Graph C*-Algebras, Alan L. Carey, John Phillips, Adam Rennie

Faculty of Engineering and Information Sciences - Papers: Part A

We review the recent construction of semifinite spectral triples for graph C^*-algebras. These examples have inspired many other developments and we review some of these such as the relation between the semifinite index and the Kasparov product, examples of noncommutative manifolds, and an index theorem in twisted cyclic theory using a KMS state.


Low-Complexity Iterative Detection In Multi-User Mimo Isi Channels, Xiaojun Yuan, Qinghua Guo, Li Ping Jan 2008

Low-Complexity Iterative Detection In Multi-User Mimo Isi Channels, Xiaojun Yuan, Qinghua Guo, Li Ping

Faculty of Engineering and Information Sciences - Papers: Part A

We propose a low-cost detection strategy for multi-user multiple-input-multiple-output (MIMO) systems with inter-symbol interference (ISI). The cyclic prefix (CP) technique is assumed. The proposed detection algorithm is derived in a very concise manner based on some elegant properties of circulant matrices. We show that multi-user detection and equalization can be carried out jointly and efficiently. © 2007 IEEE.