Engineering Commons^™

Rational Revalidation, Hosam Aleem, Timothy J. Mccarthy, Rodger Edwards

Faculty of Engineering - Papers (Archive)

The economic problems the world is currently facing have caused severe cost pressure on pharmaceutical manufacturing. Revalidation of manufacturing processes and equipment comprises a significant cost to the industry. Maintaining a validated status is a regulatory requirement. Technical issues, patient risk, and business considerations impact the organizational approach to revalidation. This discussion addresses the need for revalidation with particular attention to business considerations. Strategies to prioritise revalidation among systems and how to decide on what, how, and when to revalidate are discussed. Alternative approaches when revalidation is not possible are suggested. Costs associated with revalidation are described. Activities to reduce …

Dynamic Hand Gesture Recognition System Using Moment Invariants, Zhengmao Zou, Prashan Premaratne, Malin Premaratne, Ravi Monaragala, Nalin Bandara

Faculty of Engineering - Papers (Archive)

We have developed a dynamic hand gesture recognition system that can simplify the way humans interact with computers and many other non-critical consumer electronic equipment. The proposed system is based on the well-known “Wave Controller” technology developed at the University of Wollongong and will revolutionize video gaming and consumer electronics control interfaces. Currently, computer interfacing mainly involves keyboard, mouse, joystick or gaming wheels and occasionally voice recognition for user input. These modes of interaction have restrained the artistic ability of many users, as they are required to respond to the computer through pressing buttons or moving other apparatus. Voice recognition …

A Tool For Online Mechanics Learning Resource Sharing, Thomas Goldfinch, Anne Gardner, Timothy Mccarthy, Alan Henderson, Giles Thomas, Anna L. Carew

Faculty of Engineering - Papers (Archive)

Many hours and dollars have been spent developing new resources to improve learning outcomes in engineering mechanics courses. While many of these have been developed into packaged learning systems, available for purchase by other universities, a large proportion are available free of charge for students looking to expand their study options. Over the past eighteen months, a group of engineering academics, through Australian Learning and Teaching Council funding, has been working to develop a way of guiding students towards these online engineering mechanics learning resources. One of the outcomes of this work is an online, database-driven directory of existing online …

Flow-Induced Vibration Mitigation Using Attached Splitter-Plates, B. Stappenbelt

Faculty of Engineering - Papers (Archive)

Prior stationary cylinder studies have continually demonstrated the effectiveness of attached splitter-plates in reducing drag and lift coefficients of cylinders in steady uniform flow. The use of attached splitter-plates has even been reported to be able to completely eliminate vortex shedding in fixed cylinder investigations. In the present study, the proposed utility of attached splitter-plate wake-stabilisation as a passive control mechanism for vortex-induced vibration (VIV) mitigation was investigated. A range of splitter-plate ratios from I/D=O to 4 were examined over a reduced velocity interval of Ur=3 to 60. The addition of splitter-plates resulted in the desired effect of decreasing the …

Geotechnical Analysis Of Slopes And Landslides: Achievements And Challenges, R. Chowdhury, P. Flentje

Faculty of Engineering - Papers (Archive)

PRIMARY OBJECTIVES

Design Safe Slopes, Understand Performance of Slopes and Earth Dams, Quantify Landslide Susceptibility, Hazard and Risk, Landslide Risk Management, Reduction of Disaster Risk

ESSENTAIL INFORMATION

REGIONAL---Geology, Topography, Urbanisation, Landslide History, Triggering Factors(Rainfall ,Earthquakes etc)

SITE-SPECIFIC----Soil and Rock Types, Discontinuities ,Pore Water Pressures, Shear Strength Parameters, Unsaturated Zones, Observed Slope Movements, Quality of Data

IMPORTANT STEPS

Identify Failure Mechanisms, Develop Geotechnical Models, Parameter Variability, Systematic Uncertainties, Assess Stability/Reliability/Hazard /Risk, Validate with Respect to Observed Data

Mechanical Model Of A Floating Oscillating Water Column Wave Energy Conversion Device, Brad Stappenbelt, Paul Cooper

Faculty of Engineering - Papers (Archive)

The study of floating oscillating water column (OWC) wave energy conversion (WEC) device performance includes analysis of the dynamic coupling of the water column and the floating structure. In the present investigation, a mechanical oscillator model was proposed in order to examine this relationship for the heave motion of a floating wave energy conversion device. Characterisation of the dynamic system optimal behaviour was performed by examining the effect of relative OWC and floating structure natural frequencies, the phase relationships of the various system components and the optimal power take-off damping of the system. It was determined that separation of the …

Periodic And Continuous Landslide Monitoring To Assess Landslide Frequency – Selected Australian Examples, P. Flentje, R. Chowdhury, Anthony Miner, C. Mazengarb

Faculty of Engineering - Papers (Archive)

Landslide frequency is one of the major challenges that must be managed when undertaking a landslide risk assessment. Important issues to be considered when assessing landslide frequency include recognition of the landslide types and processes, landslide volume and magnitudes of displacement. Landslide frequency assessments must also recognize anthropogenic factors (in place and or proposed) such as any remedial measures (subsurface drainage and or retaining structures) as such works will be designed to have significant effects in reducing the frequency of landsliding at any site. Periodic and or continuous monitoring will certainly be of benefit in such assessments, but will only …

Sorption Of Steroidal Hormones By Electrodialysis Membranes, Laura J. Banasiak, Andrea I. Schafer

Faculty of Engineering - Papers (Archive)

The mechanisms of sorption of four steroidal hormones – estradiol, estrone, progesterone and testosterone – to electrodialysis (ED) membranes were investigated as a function of solution pH and presence of humic acid (HA). Hormone-membrane partition coefficients (log KAEM/CEM) determined through sorption isotherm experiments suggested that hormone sorption was due to hydrogen bonding and cation–π interactions between hormone and membrane functional groups. Progesterone sorption at pH 7 (922 μg/cm3) during ED was greater than estrone sorption (591 μg/cm3) due to its greater cation-exchange membrane (CEM) bonding affinity. Estrone sorption at pH 11 (487 μg/cm3) was reduced due to estrone dissociation and …

A Polynomial Chaos-Based Kalman Filter Approach For Parameter Estimation Of Mechanical Systems, Emmanuel D. Blanchard, Corina Sandu, Adrian Sandu

Faculty of Engineering - Papers (Archive)

Mechanical systems operate under parametric and external excitation uncertainties. The polynomial chaos approach has been shown to be more efficient than Monte Carlo for quantifying the effects of such uncertainties on the system response. Many uncertain parameters cannot be measured accurately, especially in real time applications. Information about them is obtained via parameter estimation techniques. Parameter estimation for large systems is a difficult problem, and the solution approaches are computationally expensive. This paper proposes a new computational approach for parameter estimation based on the extended Kalman filter (EKF) and the polynomial chaos theory for parameter estimation. The error covariances needed …

Kinetics Of Decarburization Reaction In Oxygen Steelmaking Process, Neslihan Dogan, Geoffrey A. Brooks, Muhammad A. Rhamdhani

Faculty of Engineering - Papers (Archive)

The steelmaking process is complex since it involves simultaneous multi-phase (solidgas- liquid) interactions, chemical reactions, heat and mass transfer and complex flow patterns at high temperatures. The transient nature of the process also adds more complexities and the severe operating conditions inhibit the direct measurement and observation of the process. This difficulty can be addressed by developing models, which make it possible to describe the complicated nature of the process itself and to understand the interconnection of important process variables. A global model of oxygen steelmaking focusing on the overall decarburization of the process and including the new bloated droplet …

Performance Enhancement Of A Complex Chilled Water System Using A Check Valve: Experimental Validation, Shengwei Wang, Zhenjun Ma, Dian-Ce Gao

Faculty of Engineering - Papers (Archive)

The large primary–secondary chilled water systems often suffer from the excess flow demand and low chilled water temperature difference, which is known as the low ΔT central plant syndrome, during operation. This paper presents an approach for experimental validation of the possible utility of a check valve (i.e., putting a one-direction check valve in the chilled water by-pass line) to solve this operational problem and enhance the overall system performance, prior to a check valve is really installed. The experimental tests were carried out on the complex central chiller plant in a super high-rise building using a simulated check valve …

Background Estimation In Mxgs Apparatus On International Space Station, Behcet Alpat, Mauro Menichelli, Diego Caraffini, Marco Petasecca, Francesca Renzi

Faculty of Engineering - Papers (Archive)

THE Atmosphere-Space Interactions Monitor (ASIM) [1] is an ESA science instrument assembly, to be installed on the Columbus External Platform Facility (CEPF) of the ISS (International Space Station), to study the giant electrical discharges (lightning) in the high-altitude atmosphere above thunderstorms. The discharges are seen as optical, X and gamma-ray flashes in the stratosphere and mesosphere. The optical emissions are dubbed red sprites, blue jets, and elves or, collectively, Transient Luminous Events (TLEs); theXand gamma-ray emissions are dubbed Terrestrial Gamma Ray Flashes (TGFs), instead. The ASIM mission comprises, therefore, two main scientific instruments: the Miniature Multi-spectral Imaging Array (MMIA) composed …

Thinking Head: Towards Human Centred Robotics, Damith C. Herath, Christian Kroos, Catherine J. Stevens, Lawrence Cavedon, Prashan Premaratne

Faculty of Engineering - Papers (Archive)

Thinking Head project is a multidisciplinary approach to building intelligent agents for human machine interaction. The Thinking Head Framework evolved out of the Thinking Head Project and it facilitates loose coupling between various components and forms the central nerve system in a multimodal perception-action system. The paper presents the overall architecture, components and the attention system. The paper then concludes with a preliminary behavioral experiment that studies the intelligibility of the audiovisual speech output produced by the Embodied Conversational Agent (ECA) that is part of the system. These results provide the baseline for future evaluations of the system as the …

Laboratory Investigation Of The Input Current Characteristics Of Modern Domestic Appliances For Varying Supply Voltage Conditions, Sean Elphick, Philip Ciufo, Sarath Perera

Faculty of Engineering - Papers (Archive)

The past decade has seen major changes to the appliances which comprise the domestic load. Appliances which may have been considered to be passive loads are now supplied through power electronic front ends. These new loads are known sources of power quality disturbances, predominately harmonic currents. While examinations have been made of the electrical behaviour of first generation electronic appliances, there is little literature dealing with the performance of more modern loads. Understanding the behaviour of modern loads is essential if accurate models of equipment connected to the power system are to be developed. This paper examines the input current …

Giant Magnetodielectric Effect In 0-3 Ni0.5zn0.5fe2o4-Poly(Vinylidene-Fluoride) Nanocomposite Films, Yiping Guo, Yun Liu, Jianli Wang, R. L. Withers, Hua Chen, Lu Jin, Paul Smith

Faculty of Engineering - Papers (Archive)

Multiferroic nanocomposite films, composed of well-dispersed, magnetic Ni_0.5Zn_0.5Fe₂O₄ (NZFO) nanoparticles (in the size range 10−20 nm) embedded into a poly(vinylidene-fluoride) copolymer matrix host, have been prepared by a modified polymer processing route. The dielectric, ferroelectric, ferromagnetic and magnetodielectric properties of these nanocomposite films have been systematically investigated. The nanocomposite films exhibit low dielectric loss and good ferroelectric character. The magnetodielectric coefficient of the resultant nanocomposite films increases as a function of the NZFO fraction and is almost frequency independent. A giant magnetodielectric coefficient up to 5.1% was obtained at room temperature and under …

Gapless Insulator And A Band Gap Scaling Law In Semihydrogenated Graphene, Anthony Wright, T E. O'Brien, Chao Zhang, Dieter Beaven

Faculty of Engineering - Papers (Archive)

We demonstrate two unusual electronic properties of semihydrogenated graphene with variable sized A- or B-hydrogenated domains within the tight-binding formalism as follows: (i) a universal band gap scaling law which states that the band gap depends linearly upon the ratio of the number of A- to B-hydrogenated atoms, N_A/N_B, reaching zero gap at N_A = N_B, but independent of the domain size, and (ii) an insulating state with zero band gap at N_A = N_B, a rare phenomenon in nature. We confirm this gapless insulator state by the zero …

Effect Of Mg/B Ratio On The Superconductivity Of Mgb2 Bulk With Sic Addition, Yun Zhang, S X. Dou, Cheng Lu, Sihai Zhou, Wenxian Li

Faculty of Engineering - Papers (Archive)

To improve the self-field critical current density (J_c) and critical temperature (T_c) in SiC-doped MgB₂, optimization of the nominal Mg/B mixing ratio has been performed. The effects of the nominal Mg/B mixing ratio (x:2) on the superconductivity, Raman spectra, current transport properties, and flux pinning mechanisms in MgB₂ with 10 wt.% SiC doping were investigated systematically, with x varied from 1 to 1.2. It has been found that the sample with the Mg/B ratio of 1.15:2 exhibited the best J_c performance for all fields (0–8.5 T), and its T_c was also …

Implementation And Application Of A Real-Time Control System Using Matlab/Xpc, Xiaofeng He, Zhengyi Jiang, Christopher David Cook, Yinshui Liu

Faculty of Engineering - Papers (Archive)

A real-time control system for rolling mill control such as the Hille 100 experimental rolling mill was developed based on Matlab Simulink, Real-Time Workshop and xPC Target. The Host-Target PCs architecture for the control system was introduced, then the approach for the implementation of data acquisition, real-time control and the associated graphic user interface (GUI), were discussed in detail. Some limitations of the commercial software were also presented. The developed control system has been verified with Hille 100 rolling mill in laboratory, indicating the effective application in rolling mill control.

Carbothermal Reduction Of A Primary Ilmenite Concentrate In Different Gas Atmospheres, Mohammad A. R Dewan, Guangqing Zhang, Oleg Ostrovski

Faculty of Engineering - Papers (Archive)

The carbothermal reduction of a primary ilmenite concentrate was studied in hydrogen, argon, and helium. Ilmenite and graphite were uniformly mixed and pressed into pellets. Reduction was studied in isothermal and temperature-programmed reduction experiments in a tube reactor with continuously flowing gas. CO, CO2, and CH4 contents in the off-gas were measured online using infrared sensors. The phase composition of reduced samples was characterized by X-ray diffraction (XRD). Oxygen and carbon contents in reduced samples were determined by LECO analyzers (LECO Corporation, St. Joseph, MI). The main phases in the ilmenite concentrate were ilmenite and pseudorutile. The reaction started with …

Research Methodologies For Engineering Asset Management, Khaled O. El-Akruti, Richard Dwight

Faculty of Engineering - Papers (Archive)

This paper serves as a guide for researchers in Asset Management (AM). Its objective is to establish sufficient reasoning to select and complement research methodologies for AM research studies. It explores literature and adds to existing research approaches in AM. This will lead to a stronger body of knowledge through a better contribution from research. AM as a discipline, addresses the management of the life cycle of assets utilized by an organisation. This extends from identification of the need to the disposal and liability thereafter. It includes technical and business activities. From this view, AM is a relatively new discipline. …

Business Modeling With The Support Of Multiple Notations In Requirements Engineering, Mohammad Moshiur Bhuiyan, Aneesh Krishna

Faculty of Engineering - Papers (Archive)

Requirements specification should not be concerned only with the software specification, but should also be able to integrate with the organizational models describing the environment in which the system will function. Agent–oriented conceptual modeling notations such as i* represents an interesting approach for modeling early phase requirements which includes organizational contexts, stakeholder intentions and rationale. Business Process Modeling notations such as BPMN are used to effectively conceptualize and communicate important process characteristics to relevant stakeholders. On the other hand, Unified Modeling Language (UML) is suitable for later phases of requirement capture which usually focus on completeness, consistency, and automated verification …

Multi-View Through-The-Wall Radar Imaging Using Compressed Sensing, Jie Yang, Abdesselam Bouzerdoum, Moeness G. Amin

Faculty of Engineering - Papers (Archive)

This paper considers the problem of Through-the-Wall Radar Imaging (TWRI) from multiple views using Compressed Sensing (CS). The scene reconstruction problem is reformulated in terms of finding a sparse representation of the target locations, consistent with the observations. In contrast to the common approach of first applying image formation to each view and then fusing the single-view images, observations from the different views are combined together into a composite measurement vector and a new dictionary is constructed accordingly. A sparse image representation of the scene is then obtained from the composite measurement vector and the new dictionary using 1 -norm …

Qos Analysis And Service Selection For Composite Services, Huiyuan Zheng, Jian Yang, Weiliang Zhao

Faculty of Engineering - Papers (Archive)

A composite service can be constructed with the arbitrary combination of sequential, parallel, loop, and conditional structures. In this paper, we propose a general solution to calculate the QoS for composite services with complex structures. We also show QoS-based service selection can be conducted based on the proposed QoS calculation method. An application example is given to show the effectiveness of the method.

General Probability Distribution-Based Qos Analysis For Web Service Composition, Huiyuan Zheng, Jian Yang, Weiliang Zhao

Faculty of Engineering - Papers (Archive)

In this paper, we propose a comprehensive solution for QoS aggregation in service composition. Different from existing work on QoS modeling which uses single values, discrete values with frequencies, or well known statistical distributions, the proposed method can work on QoS represented by general probability distributions. A set of formulas are developed to calculate the QoS probability distribution for the composite service based on the four identified patterns. Experimental results are provided to demonstrate the effectiveness of the proposed method.

Structural And Superconducting Properties Of Lafeas1-Xsbxo1-Yfy, Cao Wang, Zhifeng Ma, Shuai Jiang, Yuke Li, Zhu-An Xu, Guanghan Cao

Faculty of Engineering - Papers (Archive)

We report the antimony (Sb) doping effect in a prototype system of iron-based superconductors LaFeAsO_1−y F _y (y=0, 0.1, 0.15). X-ray powder diffraction indicates that the lattice parameters increase with Sb content within the doping limit. Rietveld structural refinements show that, with the partial substitution of Sb for As, the thickness of the Fe₂As₂ layers increases significantly, whereas that of the La₂O₂ layers shrinks simultaneously. So a negative chemical pressure is indeed “applied” to the superconducting-active Fe₂As₂ layers, in contrast to the effect of positive chemical pressure …

Qos Probability Distribution Estimation For Web Services And Service Compositions, Huiyuan Zheng, Jian Yang, Weiliang Zhao

Faculty of Engineering - Papers (Archive)

In this paper, we propose an approach to model the probability density function (PDF) of the QoS of a web service (QoWS) based on non-parametric statistical method. Mathematical formulas are designed to calculate the QoS distributions for service compositions (QoCS). Experiment has been done to show that the proposed QoWS distribution modeling approach is much more accurate than exiting methods. An accurate PDF estimation can be obtained for the QoCS if the PDF of the component QoWSs are modeled by the proposed method.

Soft Soils Improved By Prefabricated Vertical Drains: Performance And Prediction, Buddhima Indraratna, Cholachat Rujikiatkamjorn, V Wijeyakulasuriya, G Mcintosh, R Kelly

Faculty of Engineering - Papers (Archive)

The use of prefabricated vertical drains with preloading is now common practice and is proving to be one of the most effective ground improvement techniques known. The factors affecting its performance, such as the smear zone, the drain influence zone, and drain unsaturation, are discussed in this paper. In order to evaluate these effects a large scale consolidation test was conducted and it was found that the proposed Cavity Expansion Theory could be used to predict the characteristics of the smear zone based on the soil properties available. Moreover, the procedure for converting an equivalent 2-D plane strain multi-drain analysis …

Experimental Investigations Into Subballast Filtrations Behaviour Under Cyclic Conditions, Laricar Dominic Ortega Trani, Buddhima Indraratna

Faculty of Engineering - Papers (Archive)

In rail track environments the loading system is cyclic unlike the monotonic seepage force that usually occurs in embankment dams. The mechanisms of filtration, interface behaviour and time-dependent changes of the drainage and filtration properties occurring within the filter medium require further research to improve the design guidelines. A novel cyclic process simulation filtration apparatus was designed and commissioned at the University of Wollongong, and a standard testing procedure was established. The test apparatus was designed to simulate heavy haul train operations. Key parameters that influence the change in porosity and pore water pressure within the sub ballast layer under …

Stress Analysis In Failed Roof At A Longwall Face, Jan Anton Nemcik, Ian Porter, Buddhima Indraratna

Faculty of Engineering - Papers (Archive)

This paper presents a conceptual work on roof failure mechanisms at a longwall coal mining face based on a multiple sliding block model. Underground observations of the caved roof strata at the longwall face indicate that many types of fracture exist and that two are dominant. In response to roof convergence close to the goaf, the stratified ground flexes resulting in shear failure along the weak bedding planes that are present in sedimentary strata, while sub-vertical fractures form just ahead of the longwall face in response to the mining induced stress state. . These mining induced fractures usually occur at …

Performance Of A Prb For The Remediation Of Acidic Groundwater In Acid Sulfate Soil Terrain, Buddhima Indraratna, Gyanendra Regmi, Long Nghiem, A. Golab

Faculty of Engineering - Papers (Archive)

Contaminated groundwater resulting from pyrite oxidation of acid sulfate soils (ASSs) is a major environmental problem in coastal Australia. A column test was carried out for an extended period with recycled concrete to study the efficiency of the reactive materials for neutralizing acidic groundwater. Results show that the actual acid neutralization capacity of the recycled concrete could decrease to less than 50% of the theoretical value due to armoring effects. Nevertheless, the performance is good as a spot treatment in ASS Terrain using a near-zero cost waste product. Based on the test results and site characterization, a permeable reactive barrier …