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Articles 1 - 11 of 11

Full-Text Articles in Physical Sciences and Mathematics

Naturality Of Rieffel's Morita Equivalence For Proper Actions, Astrid An Huef, S Kaliszewski, Iain F. Raeburn, Dana P. Williams Jan 2011

Naturality Of Rieffel's Morita Equivalence For Proper Actions, Astrid An Huef, S Kaliszewski, Iain F. Raeburn, Dana P. Williams

Faculty of Informatics - Papers (Archive)

Suppose that a locally compact group G acts freely and properly on the right of a locally compact space T . Rieffel proved that if is an action of G on a C*-algebra A and there is an equivariant embedding of C0(T ) in M(A), then the action α of G on A is proper, and the crossed product Aα,rG is Morita equivalent to a generalised fixed-point algebra Fix(A,α ) in M(A)α. We show that the assignment (A,α) → Fix(A,α ) extends …


A Mathematical Model For The Biological Treatment Of Industrial Wastewaters In A Cascade Of Four Reactors, Annette L. Worthy, Mark I. Nelson, Rubayyi Turki Alqahtani Jan 2011

A Mathematical Model For The Biological Treatment Of Industrial Wastewaters In A Cascade Of Four Reactors, Annette L. Worthy, Mark I. Nelson, Rubayyi Turki Alqahtani

Faculty of Informatics - Papers (Archive)

Many industrial processes, particularly in the food industry, produce slurriesor wastewaters containing high concentrations of biodegradable organicmaterials. Before these contaminated wastewaters can be dischargedthe concentration of these pollutants must be reduced. A method which has beenextensively employed to remove biodegradable organic matter is biologicaltreatment. In this process the wastewater (or slurry) is passed through abioreactor containing biomass which grows through consumption of thepollutants.The industrial treatment of wastewaters typically employs a reactor cascade.In a reactor cascade of n reactors the effluent stream from the ith reactor inthe cascade acts as the feed stream for the (i+1)th reactor, i.e. the nextreactor. The …


Initial Values In Estimation Procedures For State Space Models (Ssms), Raed Alzghool, Yan-Xia Lin Jan 2011

Initial Values In Estimation Procedures For State Space Models (Ssms), Raed Alzghool, Yan-Xia Lin

Faculty of Informatics - Papers (Archive)

In this paper, we will focus on State Space Models(SSMs), especially the stochastic volatility model, and lookfor a standard approach for assigning initial values in theQuasi-Likelihood (QL) and Asymptotic Quasi-Likelhood (AQL)estimation procedures.


A Spectral-Collocation Method For Pricing Perpetual American Puts With Stochastic Volatility, Song-Ping Zhu, Wenting Chen Jan 2011

A Spectral-Collocation Method For Pricing Perpetual American Puts With Stochastic Volatility, Song-Ping Zhu, Wenting Chen

Faculty of Informatics - Papers (Archive)

Based on the Legendre pseudospectral method, we propose a numerical treatment for pricing perpetual American put option with stochastic volatility. In this simple approach, a nonlinear algebraic equation system is first derived, and then solved by the Gauss–Newton algorithm. The convergence of the current scheme is ensured by constructing a test example similar to the original problem, and comparing the numerical option prices with those produced by the classical Projected SOR (PSOR) method. The results of our numerical experiments suggest that the proposed scheme is both accurate and efficient, since the spectral accuracy can be easily achieved within a small …


A Novel Bath Lily-Like Graphene Sheet-Wrapped Nano-Si Composite As A High Performance Anode Material For Li-Ion Batteries, Jun Chen, Jun Yang, Zi-Feng Ma, Pengfei Gao, Yu-Shi He, Xiao Zhen Liao, Xiaowei Yang Jan 2011

A Novel Bath Lily-Like Graphene Sheet-Wrapped Nano-Si Composite As A High Performance Anode Material For Li-Ion Batteries, Jun Chen, Jun Yang, Zi-Feng Ma, Pengfei Gao, Yu-Shi He, Xiao Zhen Liao, Xiaowei Yang

Faculty of Science - Papers (Archive)

"A novel bath lily-like graphene sheet-wrapped nano-Si composite synthesized via a simple spray drying process exhibits a high reversible capacity of 1525 mAh g(-1) and superior cycling stability, which could be attributed to a synergistic effect between highly conductive graphene sheets and active nanoparticles in the open nano/micro-structure."


Contextual Effects In Modeling For Small Domain Estimation, Mohammad-Reza Namazi-Rad, David G. Steel Jan 2011

Contextual Effects In Modeling For Small Domain Estimation, Mohammad-Reza Namazi-Rad, David G. Steel

SMART Infrastructure Facility - Papers

Many different Small Area Estimation (SAE) methods have been proposed to overcome the challenge of findingreliable estimates for small domains. Often, the required data for various research purposes are available at differentlevels of aggregation. Based on the available data, individual-level or aggregated-level models are used in SAE.However, parameter estimates obtained from individual and aggregated level analysis may be different, in practice.This may happen due to some substantial contextual or area-level effects in the covariates which may be misspecifiedin individual-level analysis. If small area models are going to be interpretable in practice, possible contextualeffects should be included. Ignoring these effects leads …


Understanding The Conducting States Of Active And Passive Switches In An Inverter Circuit Used For Power System Applications, Danny Sutanto, B.P. Divakar, K.W.E. Cheng Jan 2011

Understanding The Conducting States Of Active And Passive Switches In An Inverter Circuit Used For Power System Applications, Danny Sutanto, B.P. Divakar, K.W.E. Cheng

Faculty of Informatics - Papers (Archive)

Bi-directional inverter circuits are commonly used in many applications in power systems, such as in FACTS devices, energy storage systems and active power filters. Many power engineering students however find it difficult to understand the conducting states of the active switches (transistors, IGBTs) and the passive switches (the antiparallel diodes connected across the active switches). It seems a mystery to them that power can flow from a lower voltage ac system to a higher voltage dc system to charge the energy storage system. This paper proposes a simple chart that intuitively explains how to determine the states (either conducting or …


Daily And 3-Hourly Variability In Global Fire Emissions And Consequences For Atmospheric Model Predictions Of Carbon Monoxide, M Mu, James Randerson, G R. Van Der Werf, L Giglio, Prasad Kasibhatla, D Morton, G J. Collatz, R S. Defries, E J. Hyer, E M. Prins, David W. Griffith, Debra Wunch, G C. Toon, V Sherlock, Paul O. Wennberg Jan 2011

Daily And 3-Hourly Variability In Global Fire Emissions And Consequences For Atmospheric Model Predictions Of Carbon Monoxide, M Mu, James Randerson, G R. Van Der Werf, L Giglio, Prasad Kasibhatla, D Morton, G J. Collatz, R S. Defries, E J. Hyer, E M. Prins, David W. Griffith, Debra Wunch, G C. Toon, V Sherlock, Paul O. Wennberg

Faculty of Science - Papers (Archive)

"Attribution of the causes of atmospheric trace gas and aerosol variability often requires the use of high resolution time series of anthropogenic and natural emissions inventories. Here we developed an approach for representing synoptic-and diurnal-scale temporal variability in fire emissions for the Global Fire Emissions Database version 3 (GFED3). We disaggregated monthly GFED3 emissions during 2003-2009 to a daily time step using Moderate Resolution Imaging Spectroradiometer (MODIS)-derived measurements of active fires from Terra and Aqua satellites. In parallel, mean diurnal cycles were constructed from Geostationary Operational Environmental Satellite (GOES) Wildfire Automated Biomass Burning Algorithm (WF_ABBA) active fire observations. Daily variability …


An Assessment Of Three Harpacticoid Copepod Species For Use In Ecotoxicological Testing, Daniel J. Ward, Victor Perez-Landa, David A. Spadaro, Stuart L. Simpson, Dianne F. Jolley Jan 2011

An Assessment Of Three Harpacticoid Copepod Species For Use In Ecotoxicological Testing, Daniel J. Ward, Victor Perez-Landa, David A. Spadaro, Stuart L. Simpson, Dianne F. Jolley

Faculty of Science - Papers (Archive)

The relatively short life cycles of harpacticoid copepods makes them appropriate animals for use in tests that rapidly assess the #180, sublethal, or chronic effects of sediment contaminants. In this study, four harpacticoid copepod species (Nitocra spinipes, Tisbe tenuimana, Robertgurneya hopkinsi, and Halectinosoma sp.) were isolated from clean marine sediments, and procedures for laboratory culturing were developed. Halectinosoma sp. was abandoned due to handling difficulties. For the remaining species, the influence of food type and quantity on life-cycle progression was assessed. A mixed diet, comprising two species of algae (Tetraselmis sp. and Isochrysis sp.) and fish food (Sera …


An Automated Land Subdivision Tool For Urban And Regional Planning: Concepts, Implementation And Testing, Rohan Wickramasuriya, Laurie A. Chisholm, Marjetta Puotinen, Nicholas Gill, Peter Klepeis Jan 2011

An Automated Land Subdivision Tool For Urban And Regional Planning: Concepts, Implementation And Testing, Rohan Wickramasuriya, Laurie A. Chisholm, Marjetta Puotinen, Nicholas Gill, Peter Klepeis

Faculty of Science - Papers (Archive)

Simulation of the land subdivision process is useful in many applied and research areas. Planners use such tools to understand potential impacts of planning regulations prior to their implementation. While the credibility of both land-use change and urban growth models would be enhanced by integrating capabilities to simulate land subdivision, such research is lacking in the published literature. Of the few subdivision tools that exist, most are either not fully-automated or are unable to generate realistic subdivision layouts. This limits their applicability, particularly for high resolution land-use change models. In this paper, we present a fully-automated land subdivision tool that …


Climate-Induced Reaction Norms For Life-History Traits In Pythons, Beata Ujvari, Richard Shine, L Luiselli, Thomas R. Madsen Jan 2011

Climate-Induced Reaction Norms For Life-History Traits In Pythons, Beata Ujvari, Richard Shine, L Luiselli, Thomas R. Madsen

Faculty of Science - Papers (Archive)

Climate change modelers predict increasingly frequent ''extreme events,'' so it is critical to quantify whether organismal responses (such as reproductive output) measured over the range of usual climatic conditions can predict responses under more extreme conditions. In a 20-year field study on water pythons (Liasis fuscus), we quantified the effects of climatically driven annual variation in food supply on demographic traits of female pythons (feeding rate, body size, body mass, and reproductive output). Reaction norms linking food supply to feeding rates and residual body mass were broadly linear, whereas norms linking food supply to female body size became curvilinear when …