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Full-Text Articles in Engineering

Minimising Power Losses In Distribution Systems With Distributed Resources, An D. T Le, Kashem M. Muttaqi, Michael Negnevitsky, Gerard Ledwich Jan 2005

Minimising Power Losses In Distribution Systems With Distributed Resources, An D. T Le, Kashem M. Muttaqi, Michael Negnevitsky, Gerard Ledwich

Faculty of Engineering and Information Sciences - Papers: Part A

Attempts to reduce electricity cost, together with improving the efficiency of distribution systems, have led power utilities to dealing with the problem of power loss minimisation. Although losses in the system can never be entirely eliminated, they can be controlled and minimised in several ways. Research conducted in the last few decades has proven that an inclusion of Distributed Resources (DR) into distribution systems considerably lowers the level of power losses. Moreover, the choice of DR is even more attractive since it provides not only benefits in power loss minimisation, but also a wide range of other advantages including environment, …


Minimising Voltage Deviation In Distribution Feeders By Optimising Size And Location Of Distributed Generation, An D. T Le, Kashem M. Muttaqi, Michael Negnevitsky, Gerard Ledwich Jan 2005

Minimising Voltage Deviation In Distribution Feeders By Optimising Size And Location Of Distributed Generation, An D. T Le, Kashem M. Muttaqi, Michael Negnevitsky, Gerard Ledwich

Faculty of Engineering and Information Sciences - Papers: Part A

A new emerging trend of distribution networks is to use small generating units, known as distributed generation (DG), operating in parallel with the main grid. This kind of distribution networks has enabled DG to support power systems in fulfilling their requirements to increase power output as well as quality of power supply. DG has potential to alter power flows, system voltages, and the system performance. In order to maximise benefits from the DG system, proper DG planning is necessary. Determining an optimal DG size and its DG location are critical issues that are addressed in this paper. The main purpose …


Dynamics Of A Hydro-Wind Hybrid Isolated Power System, M Aktarujjaman, Kashem M. Muttaqi, Michael Negnevitsky, Gerard Ledwich Jan 2005

Dynamics Of A Hydro-Wind Hybrid Isolated Power System, M Aktarujjaman, Kashem M. Muttaqi, Michael Negnevitsky, Gerard Ledwich

Faculty of Engineering and Information Sciences - Papers: Part A

Implementation of Distributed Generation (DG) can improve power quality and reliability, and guarantee continuity of power supply. This paper addresses the issue of continuity of power supply especially for isolated communities. A part of a network can be electrically isolated from the main grid when the grid fails to supply power due to a fault in the network or unavailability of power generation. In this paper, a mini hydro-wind hybrid power system is considered, and operation and control of the hybrid system during connecting it with the grid as well as its operation in the isolated condition are investigated. The …


A Bluetooth Based Protocol For Multimedia Guidebooks On Mobile Computing Devices, Matthew D'Souza, Adam Postula, Neil Bergmann, Montserrat Ros Jan 2005

A Bluetooth Based Protocol For Multimedia Guidebooks On Mobile Computing Devices, Matthew D'Souza, Adam Postula, Neil Bergmann, Montserrat Ros

Faculty of Engineering and Information Sciences - Papers: Part A

This paper presents a Bluetooth based communications protocol used for multimedia guidebooks on mobile computing devices. Multimedia guidebooks are used in museums to allow users to access information about museum exhibits. The multimedia guidebook protocol was successfully implemented on a personal digital assistant and mobile (cell) phone platforms. The protocol overcomes some of the wireless file transfer protocol limitation issues with mobile computing devices. The protocol uses Bluetooth wireless connections as a communications medium. The protocol can be used to transfer various file formats such as image or audio files. The protocol also identifies the language content of the information …


Learning Texture Similarity With Perceptual Pairwise Distance, Yan Gao, Lei Wang, Kap Luk Chan, Wei-Yan Yau Jan 2005

Learning Texture Similarity With Perceptual Pairwise Distance, Yan Gao, Lei Wang, Kap Luk Chan, Wei-Yan Yau

Faculty of Engineering and Information Sciences - Papers: Part A

In this paper, we demonstrate how texture classification and retrieval could benefit from learning perceptual pairwise distance of different texture classes. Textures as represented by certain image features may not be correctly compared in a way that is consistent with human perception. Learning similarity helps to alleviate this perceptual inconsistency. For textures, psychological experiments were shown to be able to construct perceptual pairwise distance matrix. We are going to show how this distance information could be utilized in learning similarity by Support Vector Machines for efficient texture classification and retrieval.


Mimo-Ofdm Channel Estimation In The Presence Of Carrier Frequency Offset, Jun Y. Li, Guisheng Liao, Qinghua Guo Jan 2005

Mimo-Ofdm Channel Estimation In The Presence Of Carrier Frequency Offset, Jun Y. Li, Guisheng Liao, Qinghua Guo

Faculty of Engineering and Information Sciences - Papers: Part A

A multiple-input multiple-output (MIMO) wireless communication system with orthogonal frequency division multiplexing (OFDM) is expected to be a promising scheme. However, the estimation of the carrier frequency offset (CFO) and the channel parameters is a great challenging task. In this paper, a maximum-likelihood- (ML-) based algorithm is proposed to jointly estimate the frequency-selective channels and the CFO in MIMO-OFDM by using a block-type pilot. The proposed algorithm is capable of dealing with the CFO range nearly ±1/2 useful OFDM signal bandwidth. Furthermore, the cases with timing error and unknown channel order are discussed. The Cramér-Rao bound (CRB) for the problem …


Convergence Rates Comparison Of Sum-Product Decoding Of Ra Codes Under Different Message-Passing Schedules, Sheng Tong, Baoming Bai, Xinmei Wang Jan 2005

Convergence Rates Comparison Of Sum-Product Decoding Of Ra Codes Under Different Message-Passing Schedules, Sheng Tong, Baoming Bai, Xinmei Wang

Faculty of Engineering and Information Sciences - Papers: Part A

In iterative decoding of turbo-like codes, serial schedule generally provides a much faster convergence rate compared with parallel schedule. With the aid of extrinsic information transfer (EXIT) charts, sum-product decoding of repeat accumulate (RA) codes under both message passing schedules is investigated as an example for verifying the above statement.


Conditional Ordering Using Nonparametric Expectiles, Yves Aragon, Sandrine Casanova, Raymond Chambers, Eve Leconte Jan 2005

Conditional Ordering Using Nonparametric Expectiles, Yves Aragon, Sandrine Casanova, Raymond Chambers, Eve Leconte

Faculty of Engineering and Information Sciences - Papers: Part A

Expectile regression, and more generally M-quantile regression, can be used to characterise the relationship between a response variable and explanatory variables when the behaviour of "nonaverage" individuals is of interest. The aim is to demonstrate how an individual expectile-order, based on nonparametric estimation of the expectile regression function, can also be used to define a conditional ordering of the individual's value relative to the values of other members of a data set. The relationship between contextual, or "grouping", variables and this ordering can then be investigated. In particular, we propose five estimators of expectile-order, which we compare via simulation. The …


Drag Reduction In A Flat-Plate Turbulent Boundary Layer Flow By Polymer Additives, Shu-Qing Yang, G Dou Jan 2005

Drag Reduction In A Flat-Plate Turbulent Boundary Layer Flow By Polymer Additives, Shu-Qing Yang, G Dou

Faculty of Engineering and Information Sciences - Papers: Part A

This paper presents a theoretical study on the velocity distribution and the friction factor of boundary layer flows with polymer additives starting from the concept of “stress deficit.” A novel method of order of magnitude analysis is developed, which converts the governing equations of boundary layer flow into a solvable ordinary differential equation, thus the total shear stress distribution is obtained, then the formulas for the mean velocity profiles and the friction factor for a boundary layer flow are derived after introducing appropriate expressions for the “effective viscosity” and the thickness of viscous sublayer. The derived velocity equation is able …


Measuring Preparedness To Teach With Ict, Patricia A. Forster, Vaille M. Dawson, Doug Reid Jan 2005

Measuring Preparedness To Teach With Ict, Patricia A. Forster, Vaille M. Dawson, Doug Reid

Faculty of Engineering and Information Sciences - Papers: Part A

In this paper we discuss the development and implementation of a questionnaire that measures preparedness to teach secondary school science with information and communication technologies (leT). The questionnaire was designed for the purpose of evaluating the effectiveness of instruction in a science education unit in a Graduate Diploma teacher education course. Rasch analysis of the pre- and post-unit responses indicated domains of expertise for which students perceived they had improved their knowledge during the unit, and domains for which they perceived they were less knowledgeable after the unit than before it. We discuss students' responses in relation to the unit, …


Bayesian Analysis For Penalized Spline Regression Using Winbugs, Ciprian Crainiceanu, David Ruppert, M. P. Wand Jan 2005

Bayesian Analysis For Penalized Spline Regression Using Winbugs, Ciprian Crainiceanu, David Ruppert, M. P. Wand

Faculty of Engineering and Information Sciences - Papers: Part A

Penalized splines can be viewed as BLUPs in a mixed model framework, which allows the use of mixed model software for smoothing. Thus, software originally developed for Bayesian analysis of mixed models can be used for penalized spline regression. Bayesian inference for nonparametric models enjoys the flexibility of nonparametric models and the exact inference provided by the Bayesian inferential machinery. This paper provides a simple, yet comprehensive, set of programs for the implementation of nonparametric Bayesian analysis in WinBUGS. Good mixing properties of the MCMC chains are obtained by using low-rank thin-plate splines, while simulation times per iteration are reduced …


A Multimedia Guidebook Implementation Using A Bluetooth Wireless Information Point Network, Matthew D'Souza, Adam Postula, Neil Bergmann, Montserrat Ros Jan 2005

A Multimedia Guidebook Implementation Using A Bluetooth Wireless Information Point Network, Matthew D'Souza, Adam Postula, Neil Bergmann, Montserrat Ros

Faculty of Engineering and Information Sciences - Papers: Part A

This paper describes the implementation of a Bluetooth Village Guide Book (VGB) scenario for use in the Kelvin Grove Urban Village located in Brisbane, Australia. An Information Point Station Network (IPSN) was developed, along with software for two types of mobile computing devices. The implementation consists of several Information Point Stations (IPSs) placed at locations of significance, with access to information items on a centralized server. Once a user is registered on the network, he/she is given the opportunity to experience context and eventually user aware information on demand and in various multimedia formats. These information items are selected by …


A Post-Compilation Register Re-Assignment Technique For Improving Hamming Distance Based Code Compression, Montserrat Ros, Peter Sutton Jan 2005

A Post-Compilation Register Re-Assignment Technique For Improving Hamming Distance Based Code Compression, Montserrat Ros, Peter Sutton

Faculty of Engineering and Information Sciences - Papers: Part A

Code compression is a field where compression ratios between compiler-generated code and subsequent compressed code are highly dependent on decisions made at compile time. Most optimizations employed by compilers tend to focus on parameters such as program performance, minimizing resource dependencies and sometimes the option of reducing code size. This paper describes a post-compilation technique for the greedy reassignment of general purpose scratch registers to improve Hamming distance based code compression. The code translation renumbers registers based on the frequency of registers used by isomorphic instructions and employs a Gray coding scheme to reduce Hamming distances between similar instructions. Register …


Design Of Monolimb Using Finite Element Modelling And Statistics-Based Taguchi Method, Winson Lee, Ming Zhang Jan 2005

Design Of Monolimb Using Finite Element Modelling And Statistics-Based Taguchi Method, Winson Lee, Ming Zhang

Faculty of Engineering and Information Sciences - Papers: Part A

Background. Monolimb is a transtibial prosthesis having the socket and shank molded into one piece of thermoplastic material. If properly designed, the shank of a monolimb can have a controlled deflection during walking which simulates the ankle joint motions to some extent. However, there is no clear guidance for the design of monolimb considering the dilemma between shank flexibility and structural integrity. Methods. Finite element analysis was used to simulate structural tests based on ISO10328 on monolimbs of different configurations. Statistics-based Taguchi method was employed to identify the significance of each design factor in controlling the deformation and stress within …


Mobile Locality-Aware Multimedia On Mobile Computing Devices, Matthew D'Souza, Adam Postula, Neil Bergmann, Montserrat Ros Jan 2005

Mobile Locality-Aware Multimedia On Mobile Computing Devices, Matthew D'Souza, Adam Postula, Neil Bergmann, Montserrat Ros

Faculty of Engineering and Information Sciences - Papers: Part A

This paper describes the implementation of a Bluetooth Village Guide Book (VGB) scenario for use in the Kelvin Grove Urban Village located in Brisbane, Australia. An Information Point Station Network (IPSN) was developed, along with software for two types of mobile computing devices. The implementation consists of several Information Point Stations (IPSs) placed at locations of significance, with access to information items on a centralized server. Once a user is registered on the network, he/she is given the opportunity to experience context- (and eventually user-) aware information on demand and in various multimedia formats. These information items are selected by …


Eliciting And Specifying Requirements For Highly Interactive Systems Using Activity Theory, Robert B. K. Brown, Peter Hyland, Ian C. Piper Jan 2005

Eliciting And Specifying Requirements For Highly Interactive Systems Using Activity Theory, Robert B. K. Brown, Peter Hyland, Ian C. Piper

Faculty of Engineering and Information Sciences - Papers: Part A

The processes of eliciting user requirements and formalising these into specifications are critical for the success of highly interactive systems. These processes are still poorly understood, partly because current methods are usually ad hoc and lack any theoretical basis. A number of researchers have used Activity Theory (AT) to refine these processes and have met with some success. To date, this approach has been more useful explaining the processes post hoc. This positional paper proposes an AT method for requirement elicitation and specification definition. The method is sufficiently prescriptive and well formed that it does not require any detailed understanding …


Development And Characterization Of A High-Resolution Microspect System For Small-Animal Imaging, Yujin Qi, Benjamin Tsui, Yuchuan Wang, Brian Yoder, R Wojcik, S Majewski, A G Weisenberger Jan 2005

Development And Characterization Of A High-Resolution Microspect System For Small-Animal Imaging, Yujin Qi, Benjamin Tsui, Yuchuan Wang, Brian Yoder, R Wojcik, S Majewski, A G Weisenberger

Faculty of Engineering and Information Sciences - Papers: Part A

We developed a high-resolution microSPECT system and investigated its performance characteristics for small animal imaging. The microSPECT system consists of a stationary compact gamma camera with interchangeable pinhole and parallel-hole collimators and vertical object rotation mechanism. The modular camera is based on a pixellated NaI(Tl) crystal array with 1.2 mm pixel size and 1.4 mm pixel pitch coupled to a 5” diameter Hamamatsu R3292 PSPMT. The pinhole collimator has a 10cm focal length fitted with keel-edge pinhole apertures with diameters of 1.0, 1.5 and 2.0 mm. The system performance was characterized by the measurements of the point source response function …


Ozchi 2005 Doctoral Consortium Application, Robert B. K. Brown Jan 2005

Ozchi 2005 Doctoral Consortium Application, Robert B. K. Brown

Faculty of Engineering and Information Sciences - Papers: Part A

Formal methods of generating and specifying requirements have a chequered past when it comes to dealing with interface design. The Human Computer Interface (HCI) community have not adopted formal methods with open arms [Paterno 96]. If the accurate determination of stakeholder requirements is a significant factor in determining software project success, this thesis turns to a theory based in psychology and sociology to understand these capricious actors, the misunderstanding of whose whims can bring down 70% of software projects. This thesis will deploy Activity Theory as a basis for a proposed system design method and present initial conceptions and some …


Turbo Equalization Based On Factor Graphs, Qinghua Guo, Li Ping, Hans-Andrea Loeliger Jan 2005

Turbo Equalization Based On Factor Graphs, Qinghua Guo, Li Ping, Hans-Andrea Loeliger

Faculty of Engineering and Information Sciences - Papers: Part A

This paper presents a factor graph approach to turbo equalization. Unlike the existing linear MMSE turbo equalization methods, which operate with truncated windows (sliding or extending window), the proposed is a full-window approach with low complexity. This approach supports a high-speed parallel implementation technique, which makes it an attractive option in practice.


Optimized Collimator Designs For Small Animal Spect Imaging With A Compact Gamma Camera, Yujin Qi Jan 2005

Optimized Collimator Designs For Small Animal Spect Imaging With A Compact Gamma Camera, Yujin Qi

Faculty of Engineering and Information Sciences - Papers: Part A

The aim of this study to design optimized pinhole and parallel-hole collimators for the development of a high-resolution microSPECT system using a compact pixelleted scintillation detector. The detector has a field-of-view of 11 cm with pixellated crystal elements of 1.0 mm pixel size and 1.12 mm pixel pitch. The relative resolution and sensitivity advantages of pinhole and parallel-hole collimators for mice and rats imaging were investigated using analytic formulations and Monte Carlo simulations. The optimized collimator designs were obtained by maximizing the system detection efficiency for a given object resolution. The collimator designs were optimized for 140 keV incident gamma …


A Simple Convergence Comparison Of Gallager Codes Under Two Message-Passing Schedules, Sheng Tong, Xinmei Wang Jan 2005

A Simple Convergence Comparison Of Gallager Codes Under Two Message-Passing Schedules, Sheng Tong, Xinmei Wang

Faculty of Engineering and Information Sciences - Papers: Part A

The convergence rate of iterative decoding of Gallager codes on the additive white Gaussian noise (AWGN) channel using the sum-product algorithm (SPA) under the flooding schedule (FS) is compared with that under the turbo-decoding schedule (TDS). Analyses using extrinsic information transfer (EXIT) charts show that TDS exhibits a much faster convergence behavior than FS.


Box-Minus Operation And Application In Sum-Product Algorithm, S Tong, P Wang, D Wang, X Wang Jan 2005

Box-Minus Operation And Application In Sum-Product Algorithm, S Tong, P Wang, D Wang, X Wang

Faculty of Engineering and Information Sciences - Papers: Part A

A new formula for box-minus operation, which separates the box-minus operation into sign and reliability operations, was derived. Its application in the sum-product algorithm (SPA) was also investigated. Both box-plus operation and box-minus operation were divided into sign operation and reliability operation. The results show that on using the box-minus operation, SPA can be implemented with less decoding latency and complexity.


Cmos-Aps For Hep Applications: Design And Test Of Innovative Architectures, Alessandro Marras, Daniele Passeri, Pisana Placidi, Guido Matrella, Marco Petasecca, Leonello Servoli, Gian Mario Bilei, Paollo Ciampolini Jan 2005

Cmos-Aps For Hep Applications: Design And Test Of Innovative Architectures, Alessandro Marras, Daniele Passeri, Pisana Placidi, Guido Matrella, Marco Petasecca, Leonello Servoli, Gian Mario Bilei, Paollo Ciampolini

Faculty of Engineering and Information Sciences - Papers: Part A

A set of innovative active pixel architectures has been conceived and implemented in standard CMOS technology. Active circuits are introduced into the pixel, to increase S/N ratio and to perform basic signal processing. Testing of such devices, however, becomes critical, due to the circuit relative complexity and to the need of accurately evaluating timing and position of the impinging radiation. A test strategy has thus been devised, exploiting a NIR laser source, which has been carefully characterized and tuned. The NIR laser allows for emulating, in a much more controllable fashion, a MIP event. This allow for validation of novel …


A Comprehensive Numerical Simulation Of Heavily Irradiated P-Type And N-Type Silicon Detectors, Marco Petasecca, Francesco Moscatelli, Daniele Passeri, Giorgio Umberto Pignatel, Carlo Scarpello, Giovanni Caprai Jan 2005

A Comprehensive Numerical Simulation Of Heavily Irradiated P-Type And N-Type Silicon Detectors, Marco Petasecca, Francesco Moscatelli, Daniele Passeri, Giorgio Umberto Pignatel, Carlo Scarpello, Giovanni Caprai

Faculty of Engineering and Information Sciences - Papers: Part A

In the framework of the CERN-RD50 Collaboration, the adoption of p-type substrates has been proposed as a suitable mean to Improve the radiation hardness of silicon detectors up to fluences of 1016n/cm2. In this work the simulated electrical characteristics of Irradiated p-type and n-type detectors are reported, for comparison with experimental measurements collected from the literature. The behaviour of the silicon devices at a fluence of 1016n/cm2 shows better results In term of charge collection efficiency using a p-type silicon detector.


Advanced Active Pixel Architectures In Standard Cmos Technology, Alessandro Marras, Daniele Passeri, Guido Matrella, Pisana Placidi, Marco Petasecca, Leonello Servoli, Gian Mario Bilei, Paolo Ciampolini Jan 2005

Advanced Active Pixel Architectures In Standard Cmos Technology, Alessandro Marras, Daniele Passeri, Guido Matrella, Pisana Placidi, Marco Petasecca, Leonello Servoli, Gian Mario Bilei, Paolo Ciampolini

Faculty of Engineering and Information Sciences - Papers: Part A

This paper aims at exploring and validating the adoption of standard fabrication processes for the realization of CMOS active pixel sensors, for particle detection purposes. The goal is to implement a single-chip, complete radiation sensor system, including on a CMOS integrated circuit the sensitive devices, read-out and signal processing circuits. A prototype chip (RAPS01) based on these principles has been already fabricated, and a chip characterization has been carried out; in particular, the evaluation of the sensitivity of the sensor response on the actual operating conditions was estimated, as well as the response uniformity. Optimization and tailoring of the sensor …


Encapsulation Of Validation Tests In The Esp-R Simulation Program, Paul Strachan, Georgios Kokogiannakis, I Macdonald Jan 2005

Encapsulation Of Validation Tests In The Esp-R Simulation Program, Paul Strachan, Georgios Kokogiannakis, I Macdonald

Faculty of Engineering and Information Sciences - Papers: Part A

It is well recognised that validation of dynamic building simulation programs is a long-term complex task. There have been many large national and international efforts that have led to a well-established validation methodology comprising analytical, inter-program comparison and empirical validation components, and a significant number of tests have been developed. As simulation usage increases, driven by such initiatives as the European Energy Performance of Buildings Directive, such tests are starting to be incorporated into national and international standards. Although many program developers have run many of the developed tests, there does not appear to have been a systematic attempt to …


Energy Injection By Disbributed Generation For Enhancement Of Voltage Profile In Swer Systems, Kashem M. Muttaqi, Gerard Ledwich Jan 2005

Energy Injection By Disbributed Generation For Enhancement Of Voltage Profile In Swer Systems, Kashem M. Muttaqi, Gerard Ledwich

Faculty of Engineering and Information Sciences - Papers: Part A

A system with Distributed Generation (DG) has greater load carrying capacity and can correct for a poor voltage profile during peak loading. This paper addresses the loading patterns of rural feeders and the relative effectiveness of real and reactive injection to support voltage profile in Single Wire Earth Return (SWER) systems. Real and reactive injection on a SWER network has been investigated and required energy for voltage enhancement estimated. DG with real and reactive injection (DG-PQ) using Q priority (DG-QPQ) can drastically reduce fuel and energy requirements compared to the amount required by proportional use of real and reactive power …


Maximising Voltage Support In Distribution Systems By Distributed Generation, An D. T Le, Kashem M. Muttaqi, Michael Negnevitsky, Gerard Ledwich Jan 2005

Maximising Voltage Support In Distribution Systems By Distributed Generation, An D. T Le, Kashem M. Muttaqi, Michael Negnevitsky, Gerard Ledwich

Faculty of Engineering and Information Sciences - Papers: Part A

Rapidly increasing in the demand of electricity along with recently advances in distributed generation (DG) technologies have sparked a new interest in utilisation of DG sources. However, there are a number of technical issues regarding to the installation of DG, since DG connection significantly affects existing network configuration and operation, especially for system with high level of DG penetration. To achieve maximum voltage support from DG utilisation, methodologies related to DG placement and DG operation are developed in this paper. Technique to optimise voltage improvement by effectively injecting active and reactive power of DG is developed based on voltage sensitivity …


Reinforcement Of Macroscopic Carbon Nanotube Structures By Polymer Intercalation: The Role Of Polymer Molecular Weight And Chain Conformation, C J. Frizzell, Marc In Het Panhuis, D H. Coutinho, K J. Balkus, A Minett, W J. Blau, J N. Coleman Jan 2005

Reinforcement Of Macroscopic Carbon Nanotube Structures By Polymer Intercalation: The Role Of Polymer Molecular Weight And Chain Conformation, C J. Frizzell, Marc In Het Panhuis, D H. Coutinho, K J. Balkus, A Minett, W J. Blau, J N. Coleman

Faculty of Engineering and Information Sciences - Papers: Part A

Novel polymer nanotube composites were fabricated by intercalating poly(vinylpyrrolidone) into Buckypaper from solution. This was carried out for both low (10kg∕mol) and very high (1.3Mg∕mol) molecular weight polymers. Measurements of the polymer mass uptake as a function of time allowed the calculation of diffusion coefficients as 1.66×10−9cm2∕s and 3.08×10−12cm2∕s for the low and high molecular weight strands, respectively. Taking into account the molecular weights, comparison of these coefficients suggests that each polymer type undergoes a different mode of diffusion: normal diffusion for the 10kg∕mol polymer, but reptation for the 1.3Mg∕mol polymer. This means that while the low weight polymer retains …


Hierarchical Bayesian Modeling Of The Movement Of Ice Streams, L M. Berliner, Noel A. Cressie, Kenneth Jezek, Yongku Kim, Calvin Lam Jan 2005

Hierarchical Bayesian Modeling Of The Movement Of Ice Streams, L M. Berliner, Noel A. Cressie, Kenneth Jezek, Yongku Kim, Calvin Lam

Faculty of Engineering and Information Sciences - Papers: Part A

Modern studies of the behaviors of glaciers, ice-sheets, and ice-streams rely heavily on both observations and physically based models. Data acquired via remote-sensing provide critical information on geometry and movement of ice over large sections of the Antarctic and Greenland. Though these datasets represent significant advances in terms of spatial coverage and the range of processes we can observe, the physical systems to be modeled are nevertheless incompletely observed. Uncertainties associated with measurement errors are also present. In addition, physical models are also subject to uncertainties. Hence, there is a need for combining observations and models in a fashion that …