Physical Sciences and Mathematics Commons^™

What's Your Contribution? An Online System For Assessing Each Member's Participation In Team Based Projects, Peter James Vial, Zhihao Zhang, Montserrat Ros, Christian Ritz, Geoffrey W. Trott

Faculty of Informatics - Papers (Archive)

Team based subjects in Engineering occur within the School of Electrical, Computer and Telecommunications Engineering in second and third year undergraduate degrees. In such subjects, students work in teams of between five and ten students to propose and develop engineered products for a target market place (chosen from different themes) with a small budget allocated for purchasing materials and devices. In practice, all students cannot make exactly the same contribution as each other, so a system to allocate marks for individual's contribution has been previously developed and employed within the school. This system is called the Fair Contribution Sheet (FCS) …

Hybrid Operation Of Wind-Diesel-Fuel Cell Remote Area Power Supply System, Nishad Mendis, Kashem Muttaqi, Saad Sayeef, Sarath Perera

Faculty of Informatics - Papers (Archive)

Due to the uncertainties associated with wind profiles, the load side voltage and frequency control of a wind dominated Remote Area Power Supply (RAPS) system is a challenging task. The performance of such a wind dominated hybrid RAPS system consisting of a diesel generator, fuel cell system, dump load and mains load is investigated in this paper. Integrating a fuel cell into the RAPS system enables the diesel usage to be kept at its minium level while avoiding operation of the diesel generator at low load factor. The diesel generator is used to provide the reactive power requirement of the …

Desired And Received Customer Value Models In Logistics Service Outsourcing, Yeni Sumantri, Sim Kim Lau

Faculty of Informatics - Papers (Archive)

The customer value literature offers diverse meanings of customer value concept. The significant differences among these meanings rest on interpretation or understanding of customer value. Generally, there are two major concepts of customer value. The first is desired value and the second is received value. Desired value refers to the value that customer wants to receive from product-vendor-customer interactions. Received value refers to the value that is actually experienced through product-vendor-customer interactions. Majority of research tends to focus on the received value concept. Although these two concepts are complementary, no research investigating both concepts has been conducted. This paper explores …

Control Coordination Of A Wind Turbine Generator And A Battery Storage Unit In A Remote Area Power Supply System, Nishad Mendis, Kashem Muttaqi, Saad Sayeef, Sarath Perera

Faculty of Informatics - Papers (Archive)

A novel hybrid Remote Area Power Supply (RAPS) system consisting of a Doubly Fed Induction Generator (DFIG) based wind turbine and a battery Energy Storage System (ESS) is investigated in this paper. The proposed RAPS system also consists of a dummy load and its controller. The battery energy storage system is used as a buffer which is connected to the DC link of the DFIG. The dummy load which is connected to the AC side of the system is used to absorb the energy associated with over generation, a situation which cannot be handled through the battery system. Control coordination …

Magnetic Phase Transition In Mnfep0.5as0.4si 0.1, Jianli Wang, Stewart J. Campbell, O Tegus, E Bruck, S X. Dou

Australian Institute for Innovative Materials - Papers

We have carried out a detailed investigation of the magnetic phase transition in MnFeP_0.5As_0.4Si_0.1. Temperature hysteresis has been observed in the variable temperature magnetization curves (B_appl = 0.01 T) with T_C ^W ~ 302 K on warming and T_C ^C ~ 292 K on cooling. The first order nature of this transition in MnFeP_0.5As_0.4Si_0.1 is confirmed by the negative slope obtained from isotherms of M² versus B/M around the critical temperature. Linear thermal expansion measurements reveal a large volume change, ΔV/V∼8.7×10^-3, at the …

The Control Of Time-Dependent Buckling Patterns In Thin Confined Elastomer Film, Brad Winton, Mihail Ionescu, S X. Dou

Australian Institute for Innovative Materials - Papers

Low energy metal ion implantation has been used to combine an easy “bottom-up” way of creating and tuning different topographic structures on submicron to micrometer scales with the embedding of a metallic element-rich functionalized layer at the surface for a variety of scientific and technological applications. The self-organizing and complex patterns of functionalized topographic structures are highly dependent on the implanted metal ion species, variations in the geometric confinement of the buckled areas on the larger unmodified elastomer film, and the boundary conditions of the buckled regions. Systematic investigations of these dependencies have been carried out via optical and atomic …

A Sign Of Field-Induced First Order Magnetic State Transition And Giant Reversible Magnetocaloric Effect In Cobalt Hydroxide Nanosheets, Precious Shamba, Rong Zeng, J Q Wang, S X. Dou

Australian Institute for Innovative Materials - Papers

We report the synthesis of β−Co(OH)₂ nanosheets using microwave assisted hydrothermal and conventional chemical reaction methods. A magnetic transition at an onset temperature, T₁ ~ 96 K, and a sign of antiferromagnetic state transition at the Néel temperature, T_N=9~10 K, can be determined from M-T curves and M-H curves magnetic properties investigation. It is found that a sign of field-induced first order transition below 9 K, act as a role of reversing the magnetocaloric effect from negative to positive value. The large reversible magnetic-entropy change (∆S_M) of 17 J/kg K around 11 K for …

Preliminary Sample Design For The New Zealand Health Survey 2010, Robert Graham Clark

Faculty of Informatics - Papers (Archive)

This report describes the choice of the preliminary design for the New Zealand Health Survey, to be implemented from 2011. The survey will use computer assisted personal interviewing. The sample will be selected using a multi-stage area design. The selected sample size will be around 12,000 people per year. This is envisaged as sufficient to provide adequate precision for estimates of key prevalences for adults and children. The main objectives of the sample design are: • The design should support analysis of the survey by multiple users, which implies avoiding great variation in estimation weights. • Estimates for children and …

Definition Of A Description Language For Business Service Decomposition, Lam-Son Le, Aditya K. Ghose, Evan D. Morrison

Faculty of Informatics - Papers (Archive)

In the last few years, service-oriented computing has become an emerging research topic in response to the shift from product-oriented economy to service-oriented economy and the move from focusing on software/system development to addressing business-IT alignment. From an IT perspective, there is a proliferation of methods and languages for describing Web services. There has not been as much work in defining languages or ontologies for describing services from business perspectives. In this paper, we analyze the landscape of service representation and discuss the needs of having a description language for business services. By leveraging existing work on describing service capabilities …

Strategy Representation Using An I*-Like Notation, Lam-Son Le, Bingyu Zhang, Aditya K. Ghose

Faculty of Informatics - Papers (Archive)

Assessing and achieving alignment between an organization’s strategies and its IT/business functions has long been recognized as a critically important question. This paper reports on a project that seeks to overturn established management orthodoxy by establising that strategies can be adequately modeled using conceptual modeling notations and that methodological and tool support can be provided for the task of assessing and achieving alignment between the strategies of an organization and its service offerings. A key element of this enterprise has been the design of SML - the Strategy Modeling Language. This paper presents an interim report from this project that …

A Particle Swarm Optimization Algorithm Based On Orthogonal Design, Jie Yang, Abdesselam Bouzerdoum, Son Lam Phung

Faculty of Informatics - Papers (Archive)

The last decade has witnessed a great interest in using evolutionary algorithms, such as genetic algorithms, evolutionary strategies and particle swarm optimization (PSO), for multivariate optimization. This paper presents a hybrid algorithm for searching a complex domain space, by combining the PSO and orthogonal design. In the standard PSO, each particle focuses only on the error propagated back from the best particle, without “communicating” with other particles. In our approach, this limitation of the standard PSO is overcome by using a novel crossover operator based on orthogonal design. Furthermore, instead of the “generating-and-updating” model in the standard PSO, the elitism …

Adaptive Hierarchical Architecture For Visual Recognition, Fok Hing Chi Tivive, Abdesselam Bouzerdoum, Son Lam Phung, Khan M. Iftekharuddin

Faculty of Informatics - Papers (Archive)

We propose a new hierarchical architecture for visual pattern classification. The new architecture consists of a set of fixed, directional filters and a set of adaptive filters arranged in a cascade structure. The fixed filters are used to extract primitive features such as orientations and edges that are present in a wide range of objects, whereas the adaptive filters can be trained to find complex features that are specific to a given object. Both types of filters are based on the biological mechanism of shunting inhibition. The proposed architecture is applied to two problems: pedestrian detection and car detection. Evaluation …

Automatic Human Motion Classification From Doppler Spectrograms, Fok Hing Chi Tivive, Abdesselam Bouzerdoum, Moeness G. Amin

Faculty of Informatics - Papers (Archive)

No abstract provided.

Motion Estimation With Adaptive Regularization And Neighborhood Dependent Constraint, Muhammad Wasim Nawaz, Abdesselam Bouzerdoum, Son Lam Phung

Faculty of Informatics - Papers (Archive)

Modern variational motion estimation techniques use total variation regularization along with the L1 norm in constant brightness data term. An algorithm based on such homogeneous regularization is unable to preserve sharp edges and leads to increased estimation errors. A better solution is to modify regularizer along strong intensity variations and occluded areas. In addition, using neighborhood information with data constraint can better identify correspondence between image pairs than using only a pointwise data constraint. In this work, we present a novel motion estimation method that uses neighborhood dependent data constraint to better characterize local image structure. The method also uses …

Automatic Recognition Of Smiling And Neutral Facial Expressions, Peiyao Li, S L. Phung, Abdesselam Bouzerdoum, Fok Hing Chi Tivive

Faculty of Informatics - Papers (Archive)

Facial expression is one way humans convey their emotional states. Accurate recognition of facial expressions via image analysis plays a vital role in perceptual human computer interaction, robotics and online games. This paper focuses on recognising the smiling from the neutral facial expression. We propose a face alignment method to address the localisation error in existing face detection methods. In this paper, smiling and neutral facial expression are differentiated using a novel neural architecture that combines fixed and adaptive non-linear 2-D filters. The fixed filters are used to extract primitive features, whereas the adaptive filters are trained to extract more …

Inter-Domain Routing Validator Based Spoofing Defence System, Lei Wang, Tianbing Xia, Jennifer Seberry

Faculty of Informatics - Papers (Archive)

IP spoofing remains a problem today in the Internet. In this paper, a new system called Inter-Domain Routing Validator Based Spoofing Defence System (SDS) for filtering spoofed IP packets is proposed . SDS uses efficient symmetric key message authentication code (UMAC) as its tag to verify that a source IP address is valid. Different ASes border routers obtain a shared key via the Inter-Domain Routing Validator (IRV) servers which will manage the secret keys and exchange keys among different ASes via security communication channel. SDS is efficient, secure and easy to cooperate with other defence mechanisms.

Differential Fault Analysis Of Lex, Jianyong Huang, Willy Susilo, Jennifer Seberry

Faculty of Informatics - Papers (Archive)

LEX is a stream cipher based on the round transformation of the AES block cipher, and it was selected for the final phase evaluation of the eSTREAM project. LEX is 2.5 times faster than AES both in software and in hardware. In this paper, we present a differential fault attack on LEX. The fault model assumes that the attacker is able to flip a random bit of the internal state of the cipher but cannot control the exact location of the induced fault. Our attack requires 40 faults, and recovers the secret key with 216 operations.

Social Tagging For Digital Libraries Using Formal Concept Analysis, Timothy Wray, Peter W. Eklund

Faculty of Informatics - Papers (Archive)

This paper describes the Art Collection Ecosystem – an application that allows users to tag and serendipitously browse content using Formal Concept Analysis. Within this application, tags are derived from meta-data of artworks within an existing asset management system and are classified according to theories derived from social tagging behaviour.We present past and recent iterations of its design, where it is evaluated as a contextual comparison to a popular image tagging application, Flickr. Through the process of iterative design and user evaluation, we produce results are of interest to any applied research and development that involves the exploration of digital …

Estimating Shared Copy Number Aberrations For Array Cgh Data: The Linear-Median Method, Yan-Xia Lin, Veera Baladandayuthapani, V Bonato, K.-A. Do

Faculty of Informatics - Papers (Archive)

Motivation: Existing methods for estimating copy number variations in array comparative genomic hybridization (aCGH) data are limited to estimations of the gain/loss of chromosome regions for single sample analysis. We propose the linear-median method for estimating shared copy numbers in DNA sequences across multiple samples, demonstrate its operating characteristics through simulations and applications to real cancer data, and compare it to two existing methods.

Results: Our proposed linear-median method has the power to estimate common changes that appear at isolated single probe positions or very short regions. Such changes are hard to detect by current methods. This new …

Probabilistic Neural Network For Vulnerability Prediction On A Practical Power System, Ahmed Haidar, Zulkeflee Khalidin, Ibrahim Abdulrab Ahmed

Faculty of Informatics - Papers (Archive)

Vulnerability prediction of power systems is important so as to determine its ability to continue to provide service in case of any unforeseen catastrophic contingency. It is considered one of the vital concerns due to the continual blackouts in recent years which indicate that the power system today is too vulnerable to withstand a severer disturbance. The objective of this paper is to investigate and compare the performance of two vulnerability indices used for assessing the vulnerability of power systems when subjected to various contingencies. The Probabilistic Neural Network (PNN) based on power system loss and possible loss of load …

A Longer Look At The Asymmetric Dependence Between Hedge Funds And The Equity Market, Byoung Kang, Francis In, Gunky Kim, Tong Kim

Faculty of Informatics - Papers (Archive)

This paper reexamines, at a range of investment horizons, the asymmetric dependence between hedge fund returns and market returns. Given the current availability of hedge fund data, the joint distribution of longer-horizon returns is extracted from the dynamics of monthly returns using the filtered historical simulation; we then apply the method based on copula theory to uncover the dependence structure therein. While the direction of asymmetry remains unchanged, the magnitude of asymmetry is attenuated considerably as the investment horizon increases. Similar horizon effects also occur on the tail dependence. Our findings suggest that nonlinearity in hedge fund exposure to market …

Analysis Of A Model For Ethanol Production Through Continuous Fermentation: Ethanol Productivity, Simon Watt, Harvinder Sidhu, Mark Nelson, Ajay Ray

Faculty of Informatics - Papers (Archive)

We investigate a model for the production of ethanol through continuous fermentation using Saccharomyces cerevisiae in a single reactor and cascades of up to five reactors. Using path-following methods we investigate how the ethanol productivity varies with the residence time in each reactor of the cascade. With a substrate feed concentration of 160 g/l we find the optimal productivity is 3.80 g/l/h, 5.08 g/l/h, and 5.18 g/l/h in a single reactor, a double reactor cascade and a triple reactor cascade respectively. For the case of a cascade containing reactors of equal size we investigate reactor configurations of up to five …

One Or Two Species Of The Giant Crocodylian Deinosuchus?, David R. Schwimmer

Faculty Bibliography

No abstract provided.

A Phenomenographic Study Of Introductory Physics Students: Approaches To Their Learning And Perceptions Of Their Learning Environment In A Physics Problem-Based Learning Environment, Paul Irving

Doctoral

This phenomenographic study describes students’ approaches to learning and their perceptions of the learning environment in an introductory physics course which is taught using a problem-based learning approach. This research builds on previous studies which showed that these students develop a greater conceptual knowledge than their counterparts in a more traditional learning environment while others showed very little development even though they engaged fully with the pedagogy. This study aimed to examine and describe the students’ approaches to learning. The definitions of surface, strategic and deep approaches to learning are not appropriate in this context and could not be applied …

A Parallel Non-Alignment Based Approach To Efficient Sequence Comparison Using Longest Common Subsequences, Sanjukta Bhowmick, Mohammad Shafiullah, H. Rai, Dhundy Raj Bastola

Chemistry Faculty Publications

Biological sequence comparison programs have revolutionized the practice of biochemistry, and molecular and evolutionary biology. Pairwise comparison of genomic sequences is a popular method of choice for analyzing genetic sequence data. However the quality of results from most sequence comparison methods are significantly affected by small perturbations in the data and furthermore, there is a dearth of computational tools to compare sequences beyond a certain length. In this paper, we describe a parallel algorithm for comparing genetic sequences using an alignment free-method based on computing the Longest Common Subsequence (LCS) between genetic sequences. We validate the quality of our results …

On Hyperplanes And Semispaces In Max-Min Convex Geometry, Viorel Nitica, Sergeĭ Sergeev

Mathematics Faculty Publications

No abstract provided.

Continued Fraction Proofs Of M-Versions Of Some Identities Of Rogers-Ramanujan-Slater Type, Douglas Bowman, James Mclaughlin, Nancy Wyshinksi

Mathematics Faculty Publications

We derive two general transformations for certain basic hypergeometric series from the recurrence formulae for the partial numerators and denominators of two q-continued fractions previously investigated by the authors. By then specializing certain free parameters in these transformations, and employing various identities of Rogers-Ramanujan type, we derive m-versions of these identities. Some of the identities thus found are new, and some have been derived previously by other authors, using different methods. By applying certain transformations due to Watson, Heine and Ramanujan, we derive still more examples of such m-versions of Rogers Ramanujan-type identities.

General Wp-Bailey Chains, James Mclaughlin, Peter Zimmer

Mathematics Faculty Publications

Motivated by a recent paper of Liu and Ma, we describe a number of general WP-Bailey chains. We show that many of the existing WP-Bailey chains (or branches of the WP-Bailey tree), including chains found by Andrews, Warnaar and Liu and Ma, arise as special cases of these general WP-Bailey chains. We exhibit three new branches of the WP-Bailey tree, branches which also follow as special cases of these general WP-Bailey chains. Finally, we describe a number of new transformation formulae for basic hypergeometric series which arise as consequences of these new WP-Bailey chains.

An Identity Motivated By An Amazing Identity Of Ramanujan, James Mclaughlin

Mathematics Faculty Publications

Ramanujan stated an identity to the effect that if three sequences {an}, {bn} and {cn} are defined by r1(x) =: ∑∞ n=0 anx n , r2(x) =: ∑∞ n=0 bnx n and r3(x) =: ∑∞ n=0 cnx n (here each ri(x) is a certain rational function in x), then a 3 n + b 3 n − c 3 n = (−1)n , ∀ n ≥ 0. Motivated by this amazing identity, we state and prove a more general identity involving eleven sequences, the new identity being ”more general” in the sense that equality holds not just for the power …

Some Applications Of A Bailey-Type Transformation, James Mclaughlin, Peter Zimmer

Mathematics Faculty Publications

If k is set equal to aq in the definition of a WP Bailey pair, βn(a, k) = Xn j=0 (k/a)n−j (k)n+j (q)n−j (aq)n+j αj (a, k), this equation reduces to βn = Pn j=0 αj . This seemingly trivial relation connecting the αn’s with the βn’s has some interesting consequences, including several basic hypergeometric summation formulae, a connection to the Prouhet-Tarry-Escott problem, some new identities of the Rogers-Ramanujan-Slater type, some new expressions for false theta series as basic hypergeometric series, and new transformation formulae for poly-basic hypergeometric series.