Physical Sciences and Mathematics Commons^™

A Novel Multi-Image Query Techniques For Automatic Query Concept Capture, Fenghui Ren, Philip Ogunbona, Lei Ye

Dr Fenghui Ren

No abstract provided.

A Regression-Based Approach For Improving The Association Rule Mining Through Predicting The Number Of Rules On General Datasets, Dien Tuan Le, Fenghui Ren, Minjie Zhang

Dr Fenghui Ren

Association rule mining is one of the useful techniques in data mining and knowledge discovery that extracts interesting relationships between items in datasets. Generally, the number of association rules in a particular dataset mainly depends on the measures of support and confidence To choose the number of useful rules, normally, the measures of support and confidence need to be tried many times. In some cases, the measures of support and confidence are chosen by experience. Thus, it is a time consuming to find the optimal measure of supportand confidence for the process of association rule mining in large datasets. This …

Partners Selection In Multi-Agent Systems By Using Linear And Non-Linear Approaches, Minjie Zhang, Fenghui Ren

Dr Fenghui Ren

No abstract provided.

Using Colored Petri Nets To Predict Future States In Agent-Based Scheduling And Planning Systems, Minjie Zhang, John Fulcher, Quan Bai, Fenghui Ren

Dr Fenghui Ren

No abstract provided.

Bilateral Single-Issue Negotiation Model Considering Nonlinear Utility And Time Constraint, Fenghui Ren, Minjie Zhang, John Fulcher

Dr Fenghui Ren

Bilateral single-issue negotiation is studied a lot by researchers as a fundamental research issue in agent negotiation. During a negotiation with time constraint, a negotiation decision function is usually predefined by negotiators to express their expectations on negotiation outcomes in different rounds. By combining the negotiation decision function with negotiators' utility functions, offers can be generated accurately and efficiently to satisfy negotiators expectations in each round. However, such a negotiation procedure may not work well when negotiators' utility functions are nonlinear. For example, if negotiators' utility functions are non-monotonic, negotiators may find several offers that come with the same utility; …

Defect Structure Of Sb2−Xcrxte3 Single Crystals, Jeffrey Dyck, J. HoráK, P. C. Quayle, Č. DrašAr, P. LošT’ÁK, C. Uher

Jeffrey Dyck

Single crystals of Sb2Te3 doped with Cr (cCr=0–6×1020 cm-3) were prepared by the Bridgman method. The measurements of the Hall coefficient reveal a nonmonotonous dependence of hole concentrations on the Cr content in the crystal. The hole concentration decreases at low content of Cr, while at higher content of Cr it increases again. However, according to magnetic measurements, Cr atoms enter the structure and form uncharged substitutional defects CrSb×, which cannot affect the free carrier concentration directly. The observed dependence can be elucidated by means of a point defect model. The model is based on an assumption that defect structure …

Global Trophic Position Comparison Of Two Dominant Mesopelagic Fish Families (Myctophidae, Stomiidae) Using Amino Acid Nitrogen Isotopic Analyses, C. Anela Choy, Peter C. Davison, Jeffrey C. Drazen, Adrian Flynn, Elizabeth J. Gier, Joel C. Hoffman, Jennifer P. Mcclain-Counts, Todd W. Miller, Brian N. Popp, Steve W. Ross, Tracey Sutton

Marine & Environmental Sciences Faculty Articles

The δ15N values of organisms are commonly used across diverse ecosystems to estimate trophic position and infer trophic connectivity. We undertook a novel cross-basin comparison of trophic position in two ecologically well-characterized and different groups of dominant mid-water fish consumers using amino acid nitrogen isotope compositions. We found that trophic positions estimated from the δ15N values of individual amino acids are nearly uniform within both families of these fishes across five global regions despite great variability in bulk tissue δ15N values. Regional differences in the δ15N values of phenylalanine confirmed that bulk tissue δ15N values reflect region-specific water mass biogeochemistry …

On The Distribution Of Quadratic Expressions In Various Types Of Random Vectors, Ali Akbar Mohsenipour

Electronic Thesis and Dissertation Repository

Several approximations to the distribution of indefinite quadratic expressions in possibly singular Gaussian random vectors and ratios thereof are obtained in this dissertation. It is established that such quadratic expressions can be represented in their most general form as the difference of two positive definite quadratic forms plus a linear combination of Gaussian random variables. New advances on the distribution of quadratic expressions in elliptically contoured vectors, which are expressed as scalar mixtures of Gaussian vectors, are proposed as well. Certain distributional aspects of Hermitian quadratic expressions in complex Gaussian vectors are also investigated. Additionally, approximations to the distributions of …

University Scholar Series: Craig B. Clements, Craig B. Clements

University Scholar Series

Groundbreaking Research on Wildfire Weather

On November 28, 2012 Craig B. Clements spoke in the University Scholar Series hosted by Provost Ellen Junn at the Dr. Martin Luther King, Jr. Library. Craig Clements is an associate professor in the Department of Meteorology and Climate Science who received a $900,000 National Science Foundation CAREER grant for his work in tracking atmospheric conditions in and around wildfires. His work will better help predict wildfire behavior and conditions that could lead to increased wildfire danger.

Hecke Algebras Of Group Extensions, Udo Baumgartner, James Foster, Jacqui Hicks, Helen Lindsay, Benjamin Maloney, Iain Raeburn, Jacqueline Ramagge, Sarah Richardson

Professor Jacqui Ramagge

We describe the Hecke algebra (Γ,Γ0) of a Hecke pair (Γ,Γ0) in terms of the Hecke pair (N,Γ0) where N is a normal subgroup of Γ containing Γ0. To do this, we introduce twisted crossed products of unital *-algebras by semigroups. Then, provided a certain semigroup S Γ/N satisfies S −1 S = Γ/N, we show that (Γ,Γ0) is the twisted crossed product of (N,Γ0) by S. This generalizes a recent theorem of Laca and Larsen about Hecke algebras of semidirect products.

An Introduction To Kac-Moody Groups, Jacqueline Ramagge

Professor Jacqui Ramagge

No abstract provided.

Groups, Representations And Haagerup´S Inequality For Buildings, Jacqueline Ramagge

Professor Jacqui Ramagge

No abstract provided.

A Haagerup Inequality For A1 X A1 And A2 Buildings, Jacqueline Ramagge, Guyan Robertson, Tim Steger

Professor Jacqui Ramagge

Haagerup's inequality for convolvers on free groups may be interpreted as a result on A1 buildings, i.e. trees. Here are proved analogous inequalities for discrete groups acting freely on the vertices of A1 x A1 and A2 buildings. The results apply in particular to groups of typerotating automorphisms acting simply transitively on the vertices of such buildings. These results provide the first examples of higher rank groups with property (RD).

Contraction Groups In Complete Kac-Moody Groups, Udo Baumgartner, Jacqueline Ramagge, Bertrand Remy

Professor Jacqui Ramagge

Let G be an abstract Kac-Moody group over a finite field and overlineG the closure of the image of G in the automorphism group of its positive building. We show that if the Dynkin diagram associated to G is irreducible and neither of spherical nor of affine type, then the contraction groups of elements in overline G which are not topologically periodic are not closed. (In those groups there always exist elements which are not topologically periodic.)

Factors From Buildings, Jacqueline Ramagge, A Robertson

Professor Jacqui Ramagge

No abstract provided.

Phase Transition On Exel Crossed Products Associated To Dilation Matrices, Marcelo Laca, Iain Raeburn, Jacqui Ramagge

Professor Jacqui Ramagge

No abstract provided.

Posets And Differential Graded Algebras, Jacqueline Ramagge, Wayne Wheeler

Professor Jacqui Ramagge

If P is a partially ordered set and R is a commutative ring, then a certain differential graded /f-algebra A,(P) is defined from the order relation on P. The algebra A.(Vi) corresponding to the empty poset is always contained in A.(P) so that A,(P) can be regarded as an /4.(0)-algebra. The main result of this paper shows that if R is an integral domain and P and P' are finite posets such that A.(P) = A.(P') as differential graded /4,(0)-algebras, then P and P' are isomorphic. 1991 Mathematics subject classification (Amer. Math. Soc): primary 06A06.

Affine Kac-Moody Groups Of Types Ii And Iii, Jacqueline Ramagge

Professor Jacqui Ramagge

We announce a theorum which states that, over certain fields, affine Kac-Moody groups of types II and III arise as the fixed point subgroups under particular automorphism of affine Kac_moody groups obtained from a simply laced extended Cartan matrices (and hence of type I) of higher rank. Thus our result extends a theorum on Kac-Moody algebras to corresponding groups. A detailed proof of this result will appear in the J. Algebra.

On Certain Fixed Point Subgroups Of Affine Kac-Moody Groups, Jacqueline Ramagge

Professor Jacqui Ramagge

In this paper we give a detailed description of the fixed point subgroups of certain Kac-Moody groups under particular automorphisms. We consider Kac-Moody groups arising from simply laced extended Cartan matrices and their fixed point subgroups under automorphisms which contain a non-trivial field automorphism constituent as well as a non-trivial graph automorphism constituent. We show that such a situation satisfies all the conditions of a theorem of J-Y. Hée "Torsion de groupes munis dune donnée radicelle, Théorème (4.5)" which concludes that the fixed point subgroup has a B , N )-pair and a system of root subgroups. This paper contains …

Triangle Buildings And Actions Of Type Iii 1/Q2, Jacqueline Ramagge, Guyan Robertson

Professor Jacqui Ramagge

We study certain group actions on triangle buildings and their boundaries and some von Neumann algebras which can be constructed from them. In particular, for buildings of order q ≥ 3 certain natural actions on the boundary are hyperfinite of type III_1/q².

When Does Qp Yield The Exact Solution To Constrained Nmpc?, José Mare, Jose De Dona, María Seron, Hernan Haimovich, Jacqueline Ramagge

Professor Jacqui Ramagge

It is well known that the optimal control sequence for a linear system with a quadratic cost and linear inequality constraints over a finite optimisation horizon can be computed by means of a quadratic programme (QP). The aim of this article is to investigate when the optimal control sequence for a non-linear single-input single-output system also can be computed via QP. Our main contribution is to show that the optimal control sequence for non-linear systems, with a quadratic cost and linear inequality constraints can be computed in exact form via QP provided the optimisation horizon is no larger than a …

Factors From Trees, Jacqueline Ramagge, A G. Robertson

Professor Jacqui Ramagge

We construct factors of type III,/n for n E N, n > 2, from group actions on homogeneous trees and their boundaries. Our result is a discrete analogue of a result of R.J Spatzier, where the hyperfinite factor of type III1 is constructed from a group action on the boundary of the universal cover of a manifold.

A Compactly Generated Group Whose Hecke Algebras Admit No Bounds On Their Representations, Udo Baumgartner, Jacqueline Ramagge, George A. Willis

Professor Jacqui Ramagge

We construct a compactly generated, totally disconnected, locally compact group whose Hecke algebra with respect to any compact open subgroup does not have a C∗-enveloping algebra. 2000 Mathematics Subject Classification. 20C08.

Cohomology Of Buildings And Finiteness Properties Of An-Groups, Jacqueline Ramagge, Wayne Wheeler

Professor Jacqui Ramagge

Borel and Serre calculated the cohomology of the building associated to a reductive group and used the result to deduce that torsion-free S-arithmetic groups are duality groups. By replacing their group-theoretic arguments with proofs relying only upon the geometry of buildings, we show that Borel and Serre's approach can be modied to calculate the cohomology of any locally nite ane building. As an application we show that any nitely presented e An-group is a virtual duality group. A number of other niteness conditions for e An-groups are also established.

Affine Hecke Algebras, Cyclotomic Hecke Algebras And Clifford Theory, Arun Ram, Jacqueline Ramagge

Professor Jacqui Ramagge

We show that the Young tableaux theory and constructions of the irreducible representations of the Weyl groups of type A, B and D, Iwahori-Hecke algebras of types A, B, and D, the complex reflection groups G(r, p, n) and the corresponding cyclotomic Hecke algebras Hr,p,n, can be obtained, in all cases, from the affine Hecke algebra of type A. The Young tableaux theory was extended to affine Hecke algebras (of general Lie type) in recent work of A. Ram. We also show how (in general Lie type) the representations of general affine Hecke algebras can be constructed from the representations …

Removing The Angst From Statistics, N. Baharun, A. Porter

Associate Professor Anne Porter

This paper presents the results of a case study investigating the use of video resources in teaching statistics proven to have their impact on student learning outcomes which positively affect the student understanding of topics and reduce students’ anxiety. A two-way ANOVA is utilized to analyze the sample data from forty postgraduate students in the Health Informatics at University of Wollongong. The findings from the study show that male students are significantly more confident in their understanding of statistics topics e.g. writing meaningful paragraphs about variables (p=0.014, F=6.684), producing and interpreting scatter plots and correlations (p=0.007, F=8.388); and less anxious …

Teaching Statistics Using A Blended Approach: Integrating Technology-Based Resources, N. Baharun, A. Porter

Associate Professor Anne Porter

This paper presents the results of a study investigating the use of face-to-face components of teaching and technology-based resources in teaching statistics via a blended approach. The student perspective is the focus of investigation which involved 38 on-campus students who enrolled in an introductory statistics subject at University of Wollongong. Assessment items and the laboratory manual and tasks that precede assessment were found to be of greatest importance in assisting students to understand. Students’ perceptions were that learning outcomes were positively impacted by both traditional and technologically based resources both in terms of student understanding of topics and increased their …

Experience With Change Evaluations Suggests The Need For Better Learning Designs: One Possibility For Mathematics, Bothaina Bukhatowa, Anne Porter, Mark Nelson

Associate Professor Anne Porter

A Change Evaluation was conducted in the School of Mathematics and Applied Statistics, at the University of Wollongong (UOW) with a view to identifying which resources to improve in order to facilitate better student learning outcomes. One hundred and thirty students took the subject MATH151 during the autumn term of the 2010 academic year with 101 students responding to the evaluation questionnaire. Data collection was used to discover which resources had the greatest potential for improvement or replacement and to examine if the structure of the subject could be improved for better student understanding and learning. The survey was also …

The Use Of Technology To Support Student Learning, Anne L. Porter, Norhayati Baharun

Associate Professor Anne Porter

This paper presents the results of a case study investigating the use of technology i.e. video resources in teaching statistics to 40 Health Informatics post-graduate students at the University of Wollongong. The purpose of the study is to investigate if the use of such technology has some impact on student learning outcomes in terms of their understanding of topics and level of anxiety in learning the subject. The findings from the study reveal that students were concerned about their learning of the subject and they found that the use of videos as teaching and learning tools in the subject was …

Assessment As A Tool For Learning, Maureen Morris, Anne Porter, David Atherton Griffiths

Associate Professor Anne Porter

Assessment should provide a catalyst for student learning and for reflective teaching practices. Fundamental to the development of appropriate assessment must be a direct link between what is being taught and what is being learned. Both teacher and student must be able to identify this link. The teacher needs to ensure the relevance and validity of the task in terms of both the instructional process and subject objectives. Student learning results in the construction of new knowledge through a process that assembles personally identified content and skills. Subsequent assessment may be facilitated by classification of learning outcomes. The use of …