Effective use of WebCT in a problem-based learning course for a dual mode delivery

As part of a radical curriculum change, the Faculty of Engineering and Surveying at the University of Southern Queensland (USQ) introduced a strand of four problem-based learning (PBL) courses in 2002 [1]. While the first of these courses concentrates on building team skills, the second in the strand, Engineering Problem Solving 2 (ENG2102), introduces statistical analysis, basic physics concepts and elements of GIS and mapping as part of the technical content. The annual enrolment in this course is about 250 including over 100 students studying this course externally. One of the important factors to be considered in the design and delivery of such course is to provide an effective e-learning system considering that a significant number of the students study through the distance mode

Hidden Symmetries and Commensurability of 2-Bridge Link Complements

In this paper, we show that any non-arithmetic hyperbolic $2$-bridge link complement admits no hidden symmetries. As a corollary, we conclude that a hyperbolic $2$-bridge link complement cannot irregularly cover a hyperbolic $3$-manifold. By combining this corollary with the work of Boileau and Weidmann, we obtain a characterization of $3$-manifolds with non-trivial JSJ-decomposition and rank two fundamental groups. We also show that the only commensurable hyperbolic $2$-bridge link complements are the figure-eight knot complement and the $6_{2}^{2}$ link complement. Our work requires a careful analysis of the tilings of $\mathbb{R}^{2}$ that come from lifting the canonical triangulations of the cusps of hyperbolic $2$-bridge link complements.Comment: This is the final (accepted) version of this pape

Products of Compartmental Models in Epidemiology.

We show that many structured epidemic models may be described using a straightforward product structure in this paper. Such products, derived from products of directed graphs, may represent useful refinements including geographic and demographic structure, age structure, gender, risk groups, or immunity status. Extension to multistrain dynamics, that is, pathogen heterogeneity, is also shown to be feasible in this framework. Systematic use of such products may aid in model development and exploration, can yield insight, and could form the basis of a systematic approach to numerical structural sensitivity analysis

Investors\u27 Asset Allocations versus Life-Cycle Funds

Life-cycle funds, among the newest asset allocation fund offerings, are managed according to investors\u27 time horizons and risk tolerances. Partly in response to the appearance of these funds, we examined the relationships among the risk in individual investors\u27 portfolios, their financial-planning time horizons, and their risk tolerances. Generally, we found that portfolio risk increases as time horizon and willingness to take risk increase. This relationship held when we used willingness to take risk increase. This relationship held when we used multivariate analysis. Additional factors related to portfolio risk were found to be the investors\u27 expectations of a future economic downtown, age, education, and marital status