Science and Technology Studies Commons^™

Simulation Model Of A Grid-Connected Single-Phase Photovoltaic System In Pscad/Emtdc, Brian K. Perera, Sridhar R. Pulikanti, Philip Ciufo, Sarath Perera

Faculty of Engineering and Information Sciences - Papers: Part A

In this paper, a complete simulation model of a grid-connected single-phase two-stage photovoltaic (PV) system with associated controllers is presented. The simulation model is developed in PSCAD/EMTDC simulation program. The component models of the grid-connected PV system include a PV array, a dc-dc boost converter, a voltage source converter (VSC) and an LCL filter. Components of the LCL filter, the dc-link capacitor of the VSC and the inductor of the dc-dc boost converter are established theoretically and that are used in modelling the grid-connected PV system. The control architecture of the presented system incorporates a synchronous reference frame phase-locked-loop (s-PLL), …

Improved Base-Calling And Quality Scores For 454 Sequencing Based On A Hurdle Poisson Model, Kristof De Beuf, Joachim De Schrijver, Olivier Thas, Wim Van Criekinge, Rafael A. Irizarry, Lieven Clement

Faculty of Engineering and Information Sciences - Papers: Part A

Background: 454 pyrosequencing is a commonly used massively parallel DNA sequencing technology with a wide variety of application fields such as epigenetics, metagenomics and transcriptomics. A well-known problem of this platform is its sensitivity to base-calling insertion and deletion errors, particularly in the presence of long homopolymers. In addition, the base-call quality scores are not informative with respect to whether an insertion or a deletion error is more likely. Surprisingly, not much effort has been devoted to the development of improved base-calling methods and more intuitive quality scores for this platform.

Studying The Impact Of The Corner Propagation Model On Vanet Routing In Urban Environments, Abhinay Mukunthan, Craig Cooper, Farzad Safaei, D. Franklin, Mehran Abolhasan

Faculty of Engineering and Information Sciences - Papers: Part A

Accurate modelling of the radio channel is often the most difficult aspect of a Vehicular Ad Hoc Network (VANET) simulation due to the large variability present in vehicular terrain. CORNER is a propagation model that calculates path-loss in an urban terrain with a large concentration of buildings, based on the position of the transmitter and receiver on a street map. This paper proposes additions to the CORNER propagation model to take selective multi-path fading into account and investigates the performance of the GPSR routing protocol under the CORNER propagation model in a realistic city environment.

Thermal, Microstructural And Mechanical Coupling Analysis Model For Flatness Change Prediction During Run-Out Table Cooling In Hot Strip Rolling, Xiao-Dong Wang, Fei Li, Zheng-Yi Jiang

Faculty of Engineering and Information Sciences - Papers: Part A

Non-uniformity of temperature distribution across strip width direction is the ultimate reason why the flatness defect occurs on the strip after cooling process although the strip is flat at the exit of finishing mill. One thermal, microstructural and mechanical coupling analysis model for predicting flatness change of steel strip during the run-out table cooling process was established using ABAQUS finite element software. K Esaka phase transformation kinetics model was employed to calculate the phase transformation, and coupled with temperature calculation using the user subroutine program HETVAL. Elasto-plasticity constitutive equations of steel material, in which conventional elastic and plastic strains, thermal …

Parameter Estimation Of A Regime-Switching Model Using An Inverse Stieltjes Moment Approach, X Xi, Marianito R. Rodrigo, Rogemar S. Mamon

Faculty of Engineering and Information Sciences - Papers: Part A

We address the problem of recovering the time-dependent parameters of the Black-Scholes option pricing model when the underlying stock price dynamics are modelled by a finite-state, continuous-time Markov chain. The coupled system of Dupire-type partial differential equations is derived and formulated as an inverse Stieltjes moment problem. We provide numerical illustration on how to apply our method to simulated financial data. The accuracy of the model parameter estimation is examined and sensitivity analyses are included to study the behaviour of the estimated results when model parameters are varied.

A Social Network Model For Understanding Technology Use For Knowledge-Intensive Workers, Kon Shing Kenneth Chung

Faculty of Engineering and Information Sciences - Papers: Part A

This chapter presents a theoretical model based on social network theories and the social influence model for understanding how knowledge professionals utilise technology. In particular, the association between egocentric network properties (structure, position and tie) and information and communication technology (ICT) use of individuals in knowledge-intensive and geographically dispersed settings is explored. A novel triangulation methodology is adopted where in-depth interviews and observation techniques were utilised to develop constructs for the conceptual model which were then vetted by domain-level experts. A reliable and validated social network-based questionnaire survey is also developed to operationalise the model. Results show that task-level ICT …

A Novel Integrated Model To Measure Supplier Performance Considering Qualitative And Quantitative Criteria Used In The Supplier Selection Process, Alptekin Ulutas, Senevi Kiridena, Peter Gibson, Nagesh Shukla

Faculty of Engineering and Information Sciences - Papers: Part A

Supplier evaluation has become a significant topic over the past few decades, as companies have become more outsourced oriented. However, previous research on this topic has not paid adequate attention to the limitations associated with the availability of accurate and reliable data relating to the performance of potential suppliers. In an attempt to address this issue, this paper proposes a novel supplier evaluation model that can handle imprecise quantitative and qualitative data. Additionally, Decision Maker's judgement regarding both qualitative and quantitative criteria are incorporated into this model so that a more comprehensive and realistic assessment of supplier performance can be …

Evaluating Disaster Management Knowledge Model By Using A Frequency-Based Selection Technique, Siti Hajar Othman, Ghassan Beydoun

Faculty of Engineering and Information Sciences - Papers: Part A

Disaster Management (DM) is a multidisciplinary endeavour and a very difficult knowledge domain to model. It is a diffused area of knowledge that is continuously evolving and informally represented. Metamodel is the output artefact of metamodelling, a software engineering approach, which makes statements about what can be expressed in the valid models of the knowledge domain. It is an appropriate high level knowledge structure to facilitate it being communicated among DM stakeholders. A Disaster Management Metamodel (DMM) is developed. To satisfy the expressiveness and the correctness of a DMM, in this paper we present a metamodel evaluation technique by using …

Prediction Model Of A Joint Analysis Of Beef Growth And Carcass Quality Traits, H R. Mirzaei, Arunas P. Verbyla, Wayne S. Pitchford

Faculty of Engineering and Information Sciences - Papers: Part A

A joint growth-carcass analysis was conducted to develop equations for predicting carcass quality traits associated with variation in growth path of crossbred cattle. During a four-year period (1994-1997) of the Australian "Southern Crossbreeding Project", mature Hereford cows (r = 581) were mated to 97 sires of Jersey, Wagyu, Angus, Hereford, South Devon, Limousin, and Belgian Blue breeds, resulting in 1141 calves. Data included body weight measurements of steers and heifers from birth until slaughter and four carcass quality traits: hot standard carcass weight, rump fat depth, rib eye muscle area, and intramuscular fat content. The model provides nine outputs: median …

Development Of A Lifetime Model For Vrla Batteries Used In Wind Turbine Generators, Xiaolin Wang, Stephen Choi, Tieling Zhang, K J. Tseng

Faculty of Engineering and Information Sciences - Papers: Part A

An approach to predict the remaining lifetime of lead-acid battery is described. The battery is used to provide back-up power to keep essential devices within wind turbine generators operational under emergency conditions. The approach is developed from a circuit model of the battery. From the results of laboratory tests, changes in the model parametric values due to ambient temperature variations, battery aging effects as well as discharge current level have been quantified. Through a developed computational method, the terminal voltage and state of charge of the battery at any other discharging conditions can then be calculated. The discharge profile allows …

Model Tests On Free-Standing Passive Pile Groups In Sand, Wei-Dong Guo, E. H. Ghee

Faculty of Engineering and Information Sciences - Papers: Part A

A number of tests have been conducted to investigate response of vertically loaded capped pile groups in sand undergoing uniform lateral soil movement. The development of shear force, bending moment and deflection along the piles was measured. Presented in this paper are 4 tests on 2-pile free-standing groups, with a view to establish solutions for predicting the pile response. It was concluded that (1) maximum bending moment Mmax is largely linearly related to the sliding force Tmax in stable and moving layers; (2) The combined impact of pile-cap fixity, soil movement profiles, and axial load may be quantified by a …

Numerical Study On Self-Similar Pulses In Mode-Locking Fiber Laser By Coupled Ginzburg-Landau Equation Model, Ting Lei, Chenghou Tu, Fuyun Lu, Yixin Deng, Enbang Li

Faculty of Engineering and Information Sciences - Papers: Part A

A theoretical model is established to study the self-similar pulses in nonlinear polarization evolution (NPE) mode-locked fiber lasers. The propagation of pulse in single mode fibers and gain fibers are described by coupled Ginzburg- Landau equation (GLE). Two wave plates and a polarizer are considered to realize the NPE mechanism in simulation. This model describes the laser completely and provides some useful pulses' information. In our simulation the laser generates high quality self-similar pulses output. The region of steady self-similar pulses operation is found. The polarization states of different parts across the pulse are simulated along the laser cavity. It …

Discovering Prediction Model For Environmental Distribution Maps, Ke Zhang, Huidong Jin, Nianjun Liu, Rob Lesslie, Lei Wang, Zhouyu Fu, Terry Caelli

Faculty of Engineering and Information Sciences - Papers: Part A

Currently environmental distribution maps, such as for soil fertility, rainfall and foliage, are widely used in the natural resource management and policy making. One typical example is to predict the grazing capacity in particular geographical regions. This paper uses a discovering approach to choose a prediction model for real-world environmental data. The approach consists of two steps: (1) model selection which determines the type of prediction model, such as linear or non-linear; (2) model optimisation which aims at using less environmental data for prediction but without any loss on accuracy. The latter step is achieved by automatically selecting non-redundant features …

A Polyhedral Model For Carbon Nanotubes, Barry Cox, James Hill

Faculty of Engineering and Information Sciences - Papers: Part A

A new structural model accounts for the curvature inherent in their cylindrical shape.

A Quasi-Dynamic Nonlinear Finite Element Model To Investigate Prosthetic Interface Stresses During Walking For Trans-Tibial Amputees, Xiaohong Jia, Ming Zhang, Xiaobing Li, Winson Lee

Faculty of Engineering and Information Sciences - Papers: Part A

Background. To predict the interface pressure between residual limb and prosthetic socket for trans-tibial amputees during walking. Methods. A quasi-dynamic finite element model was built based on the actual geometry of residual limb, internal bones and socket liner. To simulate the friction/slip boundary conditions between the skin and liner, automated surface-to-surface contact was used. Besides variable external loads and material inertia, the coupling between the large rigid displacement of knee joint and small elastic deformation of residual limb and prosthetic components were also considered. Results. Interface pressure distribution was found to have the same profile during walking. The high pressures …

Smoothing With Mixed Model Software, Long Ngo, M P. Wand

Faculty of Engineering and Information Sciences - Papers: Part A

Smoothing methods that use basis functions with penalization can be formulated as fits in a mixed model framework. One of the major benefits is that software for mixed model analysis can be used for smoothing. We illustrate this for several smoothing models such as additive and varying coefficient models for both S-PLUS and SAS software. Code for each of the illustrations is available on the Internet.

Www Sites Vs. Applications Software: The Dais Model, Lejla Vrazalic, Peter N. Hyland

Faculty of Engineering and Information Sciences - Papers: Part A

Since the advent and widespread use of the Internet, it has become apparent that there are significant differences between applications software and WWW sites which warrant a re-examination of HCI design and evaluation methods. Previous research has identified and documented the factors which differentiate between applications software and WWW sites, however a well defined model of these differences and their origins was not available. This paper defines such a model of Distinguishing Attributes for Informational Sites (DAIS). © 2003 ACM.

Does The Model Matter For Greg Estimation? A Business Survey Example, Dan Hedlin, Hannah Falvey, Raymond Chambers, Phillip Kokic

Faculty of Engineering and Information Sciences - Papers: Part A

Although asymptotically design-unbiased, GREG estimators may produce bad estimates. The article examines the behaviour of GREG estimators when the underlying models are misspecified. It shows how an efficient GREG estimator was found for a business survey that posed some problems. The work involved data exploration in several steps, combined with analyses of g-weights, residuals and standard regression diagnostics. We discuss two diagnostics for whether a GREG estimate is reasonable or not. A common justification for the use of GREG estimators is that, being asymptotically design unbiased, they are relatively robust to model choice. However, we show that the property of …

Wiener Model Identification And Predictive Control For Dual Composition Control Of A Distillation Column, H H J Bloemen, C T. Chou, T J J Van Den Boom, V Verdult, M Verhaegen, T C. Backx

Faculty of Engineering and Information Sciences - Papers: Part A

The benefits of using the Wiener model based identification and control methodology presented in this paper, compared to linear techniques, are demonstrated for dual composition control of a moderate-high purity distillation column simulation model. An identification experiment design is presented which enables one to identify both the low and high gain directions of the distillation column, properties which are important for control and hard to identify in a conventional identification experiment setup as is demonstrated in the paper. Data from the proposed experiment design is used for indirect closed-loop identification of both a linear and a Wiener model, which shows …

A Physical Model For The Hard X-Ray Background, R J. Wilman, A C. Fabian, Paul E J Nulsen

Faculty of Engineering and Information Sciences - Papers: Part A

We combine a semi-analytic galaxy formation model with a prescription for the obscured growth of massive black holes, to reproduce the hard X-ray background (XRB), the local 2–10 keV active galactic nuclei (AGN) luminosity function and the source counts, including recent Chandra results. The model also complies with constraints on the AGN contribution to the far-infrared and submillimetre backgrounds.

The comoving density of luminous AGN [L(2-10keV) > 10⁴⁴ erg s^-1, in the unabsorbed rest-frame] in the model declines sharply since z=2, mimicking the observed evolution of the quasar population. The abundance of lower luminosity AGN simultaneously increases, and …

A Three-Dimensional Numerical Model Of The Response Of The Australian North West Shelf To Tropical Cyclones, Song-Ping Zhu, Jorg Imberger

Faculty of Engineering and Information Sciences - Papers: Part A

A three-dimensional barotropic and baroclinic model is developed to simulate currents and temperature changes induced by tropical cyclones traversing the continental shelf and slope region of the Australian North West Shelf. The model is based on a layered, explicit, finite difference formulation using the nonlinear primitive equations with an embedded entrainment scheme; a mixed-surface-layer interface is defined, which is allowed to shift from one interface to another, depending on the strength of a storm. The model has been tested by simulating the currents and temperature changes induced by tropical cyclones Orson and Ian. The modelled currents and temperatures agreed well …

Relative Accuracy Of A Neighbour Method For Field Trials, W J. Lill, A C. Gleeson, Brian R. Cullis

Faculty of Engineering and Information Sciences - Papers: Part A

Two scries of simulation experiments were used to investigate the accuracy of treatment and variance estimation with a neighbour analysis of field trials proposed by Gleeson & Cullis (1987). The first series examined the accuracy of residual maximum likelihood (REML) estimation of seven theoretical error models applicable to field trials. REML estimation provided accurate estimates of the variance parameters, but the Ftest of treatments was slightly biased upward (to +2·4%) for first differences models and slightly biased downwards (to –1·4%) for second differences models. The second series of simulations, based on 19 uniformity data sets, illustrated that treatment effects were …