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Articles 1 - 12 of 12

Full-Text Articles in Social and Behavioral Sciences

The Toeplitz Algebra Of A Hilbert Bimodule, Neal J. Fowler, Iain Raeburn Jan 1999

The Toeplitz Algebra Of A Hilbert Bimodule, Neal J. Fowler, Iain Raeburn

Faculty of Engineering and Information Sciences - Papers: Part A

Suppose a C โˆ— -algebra A acts by adjointable operators on a Hilbert A -module X. Pimsner constructed a C โˆ— -algebra ๐’ช X which includes, for particular choices of X , crossed products of A by Z , the Cuntz algebras ๐’ช n , and the CuntzKrieger algebras ๐’ช B. Here we analyse the representations of the corresponding Toeplitz algebra. One consequence is a uniqueness theorem for the ToeplitzCuntz-Krieger algebras of directed graphs, which includes Cuntzโ€™s uniqueness theorem for ๐’ช โˆž.


Consideration Of Probability Assessments Relevant To Hazard And Risk For Landslides, R N. Chowdhury, P N. Flentje Jan 1999

Consideration Of Probability Assessments Relevant To Hazard And Risk For Landslides, R N. Chowdhury, P N. Flentje

Faculty of Engineering and Information Sciences - Papers: Part A

Probability of occurrence is the most important component of landslide hazard and risk and this paper outlines different approaches for its assessment. The reasons for the popularity of qualitative approaches are first outlined. Quantitative approaches can be best applied if the important influencing factors and issues are fully understood. Formal probabilistic approaches are often based on geotechnical models or on a combination of hydrological and geotechnical models. The paper also highlights the situations for which the performance function must be formulated in terms of lateral displacements rather than the conventional safety factor. Reference is then made to a procedure, based ...


Magnetic Circuit Of A Synchronous Reluctance Motor, P P. Ciufo, D. Platt, B S. P Perera Jan 1999

Magnetic Circuit Of A Synchronous Reluctance Motor, P P. Ciufo, D. Platt, B S. P Perera

Faculty of Engineering and Information Sciences - Papers: Part A

This paper presents a model of the magnetic circuit for an axially laminated synchronous reluctance motor. The basis of the modelling technique is the determination of a value for an equivalent ``q-channel'' reluctance. This reluctance contains all the effects of paths available to q-axis flux through the rotor body. Expressions for the distribution of airgap and other motor fluxes have been developed from basic analyses involving mmf and continuity of flux. The foundations of all of these expressions are the physical parameters of the motor. The equations developed have been applied to a 370 W motor and the results from ...


Instrumentation For Slope Stability - Experience From An Urban Area, P N. Flentje, R N. Chowdhury Jan 1999

Instrumentation For Slope Stability - Experience From An Urban Area, P N. Flentje, R N. Chowdhury

Faculty of Engineering and Information Sciences - Papers: Part A

This paper describes the monitoring of several existing landslides in an urban area near Wollongong in the state of New South Wales, Australia. A brief overview of topography and geology is given and reference is made to the types of slope movement, processes and causal factors. Often the slope movements are extremely slow and imperceptible to the eye, and catastrophic failures are quite infrequent. However, cumulative movements at these slower rates do, over time, cause considerable distress to structures and disrupt residential areas and transport routes. Inclinometers and piezometers have been installed at a number of locations and monitoring of ...


Quantitative Landslide Hazard Assessment In An Urban Area, Phillip N. Flentje, Robin N. Chowdhury Jan 1999

Quantitative Landslide Hazard Assessment In An Urban Area, Phillip N. Flentje, Robin N. Chowdhury

Faculty of Engineering and Information Sciences - Papers: Part A

Before decisions can be made concerning the management of sloping areas subject to landsliding, systematic approaches for hazard and risk assessment must be developed. This paper is limited to a discussion of hazard assessment and describes quantitative approaches which have been developed for existing landslides. Consideration of areas of potential landsliding is outside the scope of the paper. The approach described here is based on (a) monitoring of subsurface shear movement at instrumented sites and (b) the percentage exceedance time of cumulative rainfalls considering different selected periods of antecedent rainfall. This approach is used in conjunction with a simpler approach ...


Landslide Risk Assessment - Development Of A Hazard Consequence Approach, Chit Ko Ko, Phillip N. Flentje, Robin N. Chowdhury Jan 1999

Landslide Risk Assessment - Development Of A Hazard Consequence Approach, Chit Ko Ko, Phillip N. Flentje, Robin N. Chowdhury

Faculty of Engineering and Information Sciences - Papers: Part A

Several Landslide Hazard and Risk Assessment methods have been developed and used in the State of New South Wales (NSW), Australia. The Rail Services Australia Geotechnical Services and the Roads and Traffic Authority of NSW have each developed Risk Assessment procedures suitable to their own specific needs. A generic risk management methodology is presented in the Australian Standard/New Zealand Standard (AS/NZS) 4360:1995. An approach similar to the (AS/NZS) 4360:1995 Risk Management Standard has been applied by a NSW State Emergency Services geotechnical team (which included one of the writers) to 191 problem sites in the ...


Aspects Of Recent Landslide Research At The University Of Wollongong, Robin N. Chowdhury, Phillip N. Flentje, Chit Ko Ko Jan 1999

Aspects Of Recent Landslide Research At The University Of Wollongong, Robin N. Chowdhury, Phillip N. Flentje, Chit Ko Ko

Faculty of Engineering and Information Sciences - Papers: Part A

This paper introduces the issues which are of critical importance to landslide hazard and risk assessment and management. These include understanding of probability and consequence, the separation of the role of site-dependent factors from that of influencing/triggering natural events and the factors influencing target levels of risk. The research completed at the University of Wollongong is then outlined. This includes the development of an observational approach based on monitoring of subsurface movements at individual sites and appropriate use of rainfall data in terms of the concept of annual rainfall percentage exceedance time (ARPET). Attention is then focused on current ...


Geotechnical Assessment And Management Of 148 Landslides Triggered By A Major Storm Event In Wollongong, Australia, P N. Flentje, R N. Chowdhury Jan 1999

Geotechnical Assessment And Management Of 148 Landslides Triggered By A Major Storm Event In Wollongong, Australia, P N. Flentje, R N. Chowdhury

Faculty of Engineering and Information Sciences - Papers: Part A

On the 17th August 1998 a severe rainfall event occurred over a widespread area of the City of Wollongong. During this storm, 1 person drowned and an estimated $50 to $100 million damage was caused to the City of Wollongong. Road access to the City was cut by raised water levels and debris flows covering and or scouring road and rail routes for up to 36 hours following this event. A geotechnical team of 3, including the first author, was organised at very short notice during the response phase of the emergency operations on the early morning of the 20th ...


Optimization Of Soliton Amplitude In Dispersion-Decreasing Nonlinear Optical Fibres, Ken I M Mckinnon, Noel Smyth, Annette L. Worthy Jan 1999

Optimization Of Soliton Amplitude In Dispersion-Decreasing Nonlinear Optical Fibres, Ken I M Mckinnon, Noel Smyth, Annette L. Worthy

Faculty of Engineering and Information Sciences - Papers: Part A

The compression of a cw into a periodic train of noninteracting solitons by a dispersion-decreasing fiber is investigated with a variational method. To model the evolution from the cw to the soliton train, an elliptic-function-based expression is used as the trial function in the averaged Lagrangian. Both a continuous dispersion variation and a step dispersion variation in the fiber are considered. By use of an optimization method based on the approximate variational equations, the optimal dispersion profile required for achieving maximum pulse compression in a fixed length of fiber is determined. The solutions of the approximate equations are compared with ...


Lie Algebras Of Cohomological Codimension One, Grant F. Armstrong, Grant Cairns, Gunky Kim Jan 1999

Lie Algebras Of Cohomological Codimension One, Grant F. Armstrong, Grant Cairns, Gunky Kim

Faculty of Engineering and Information Sciences - Papers: Part A

We show that if g is a finite dimensional real Lie algebra, then g has cohomological dimension cd(g) = dim(g) - 1 if and only if g is a unimodular extension of the two-dimensional non-Abelian Lie algebra aff.


Simulated Annealing: Searching For An Optimal Temperature Schedule, Harry Cohn, Mark James Fielding Jan 1999

Simulated Annealing: Searching For An Optimal Temperature Schedule, Harry Cohn, Mark James Fielding

Faculty of Engineering and Information Sciences - Papers: Part A

A sizable part of the theoretical literature on simulated annealing deals with a property called convergence, which asserts that the simulated annealing chain is in the set of global minimum states of the objective function with probability tending to 1. However, in practice, the convergent algorithms are considered too slow, whereas a number of nonconvergent ones are usually preferred. We attempt a detailed analysis of various temperature schedules. Examples will be given of when it is both practically and theoretically justified to use boiling, fixed temperature, or even fast cooling schedules which have a small probability of reaching global minima ...


Network Reconfiguration For Load Balancing In Distribution Networks, Kashem M. Muttaqi, Velappa Ganapathy, G G. Jasmon Jan 1999

Network Reconfiguration For Load Balancing In Distribution Networks, Kashem M. Muttaqi, Velappa Ganapathy, G G. Jasmon

Faculty of Engineering and Information Sciences - Papers: Part A

Network reconfiguration of a power distribution system is an operation to alter the topological structure of distribution feeders by changing opedclosed status of sectionalising and tie switches. By transferring loads from the heavily loaded feeders to the lightly loaded ones, network reconfiguration can balance feeder loads and alleviate overload conditions of a network. The branch load-balancing index and the overall system load-balancing index are used to determine the loading conditions of the system and maximum system loading capacity. The index value has to be minimum in the optimal configuration of load balancing. For optimal load balancing condition the branch load-balancing ...