Crews, K 2009, 'Australian Journal of Structural Engineering: Preface', Australian Journal of Structural Engineering, vol. 9, no. 3.
Dackermann, U, Li, J & Samali, B 2009, 'Damage Identification in Timber Bridges Utilising the Damage Index Method and Neural Network Ensembles', Australian Journal of Structural Engineering, vol. 9, no. 3, pp. 181-194.
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Many of Australia's timber bridges are in aged and decayed conditions. In order to ensure the reliability of these structures and the safety of the public, condition assessment, damage detection and safety evaluation is necessary. This paper presents a damage identification procedure, which is based on global change of vibration characteristics of a structure. The developed method utilises the damage index (DI) method in combination with neural network techniques to identify damage in numerical and experimental timber beam structures. The neural network ensemble approach is utilised in order to respect important diversities of different modes and to integrate individual characteristics of vibrational mode separated damage features. The method considers field testing issues associated with measurement noise, limited number of sensor arrays and environmental fluctuations. The results of damage detection using the proposed approach demonstrate its ability to determine the location and severity of all present damage cases. The outcomes show that the developed damage detection method is effective, robust and reliable.
De Silva, P, Bucea, L & Sirivivatnanon, V 2009, 'Chemical, microstructural and strength development of calcium and magnesium carbonate binders', CEMENT AND CONCRETE RESEARCH, vol. 39, no. 5, pp. 460-465.
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Fatahi, B, Khabbaz, H & Indraratna, B 2009, 'Parametric studies on bioengineering effects of tree root-based suction on ground behaviour', ECOLOGICAL ENGINEERING, vol. 35, no. 10, pp. 1415-1426.
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Using native vegetation to improve soil stiffness, stabilise slopes and control erosion is a rapidly evolving process. A theoretical model previously developed by the authors for the rate of tree root water uptake together with an associated numerical simulation is used to study the effects of a wide range of soil, tree, and atmospheric parameters on partially saturated ground. The influence of different parameters on the maximum initial rate of root water uptake is investigated through parametric and sensitivity analyses. Field measurements taken from previously published literature are compared with numerical predictions for validation. The rate of selected parameters such as potential transpiration and its distribution, suction at wilting point, the coefficient of permeability and the distribution of root length density are studied in detail. The analysis shows that the rate of potential transpiration increases the soil matric suction and ground settlement, while the potential transpiration rate has an insignificant effect on the distribution of soil suction. Root density distribution factors affect the size of the influence zone. Suction at the wilting point increases the soil matric suction and ground settlement, whereas the saturation permeability decreases the maximum soil matric suction generated. The analysis confirms that the most sensitive parameters, including the coefficients of the tree root system, the transpiration rate, the permeability of the soil and its suction at the wilting point should be measured or estimated accurately for an acceptable prediction of ground conditions in the vicinity of trees. © 2009 Elsevier B.V. All rights reserved.
Gerber, C & Crews, K 2009, 'Timber Stressed-Skin Panels: Design Guidelines for Australian Practice', Australian Journal of Structural Engineering, vol. 9, no. 3, pp. 207-216.
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this paper puts forward a design procedure and proposes, in the form of an amendment to Section 5 of AS1720.1-1997, to include these directives in a future edition of the design code. The design procedure discussed herein is thorough in scope and straightforward in application. It addresses the composite characteristics of SSP structures - composite action and tributary width of the sheathing. It provides clear guidelines for the assessment of both aspects. It also imposes a systematic verification of the different stresses experienced by the structure. This particular section of the design procedure considers both AS1720.1-1997 and Eurocode 5 (European Committee for Standardisation, 1995). In addition, a method to account for the two-way action ability of SSP structures is also proposed in the design procedure, which includes two equations derived by Gerber (2007). For defined applications, acceptable assessments of the load distribution in SSP systems are achieved with these two equations for loading on an exterior and interior joist, respectively.
Hien, LV, Ha, QP & Phat, VN 2009, 'Stability and stabilization of switched linear dynamic systems with time delay and uncertainties', APPLIED MATHEMATICS AND COMPUTATION, vol. 210, no. 1, pp. 223-231.
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This paper considers the problem of exponential stability and stabilization of switched linear time-delay systems. The system parameter uncertainties are time-varying and unknown but norm-bounded. The delay in the system states is also time-varying. By using an improved Lyapunov-Krasovskii functional, a switching rule for the exponential stability and stabilization is designed in terms of the solution of Riccati-type equations. The approach allows for computation of the bounds that characterize the exponential stability rate of the solution. Numerical examples are given to illustrate the results.
Hu, H, Li, Y & Wang, J 2009, 'Structural design and dynamic characteristics analysis for a magneto-rheological gun recoil shock absorber under impact load', Zhongguo Jixie Gongcheng/China Mechanical Engineering, vol. 20, no. 4, pp. 389-393.
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A full-scale mock-up for MR shock absorber characterized with multistage slotted and smoothness disposal under impact load was firstly established. Considering the dynamic of MR shock absorber under impact load, an inertia factor was introduced to Herschel-Bulkley model, which led to two revised models, named as Herschel-Bulkley-Inertia model. And a suit of real-time measuring and controlling simulation experimental platform including hardware and software for dynamic response of MR gun recoil shock absorber under impact load was developed. The parameters in Bingham-Inertia model and Herschel-Bulkley-Inertia model were identificated by using the testing data. Further, the testing results prove that the designed MR gun recoil long-stroke shock absorber's dynamic performance under impact load can be well controlled by changing the applied current, and the dynamic response models for MR gun recoil shock absorber under impact load are proved.
Hu, HS, Wang, J & Li, YC 2009, 'Design and magnetic analysis of a gun recoil magneto-rheological damper', Dandao Xuebao/Journal of Ballistics, vol. 21, no. 2, pp. 78-82.
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A gun recoil magneto-rheological (MR) damper under impact load was researched. A full-scale gun recoil MR damper with long-stroke, multistage slotted and smoothness disposal was designed. The coupling problem between structure and magnetic circuit for MR recoil damper was solved by the electromagnetic field finite element analysis software, and the electromagnetic field distribution of the designed gun recoil MR damper was also analyzed under different conditions, such as coil ringing direction, plunger and steel cylinder part's material selection, dampen channel, smoothness and chamfering disposal, etc. The magnetic circuit design rules of MR recoil damper under high impact load were also concluded. The simulation results indicate that the performance of the designed gun recoil damper satisfy the design requirements.
Indraratna, B, Rujikiatkamjorn, C, Vinod, J & Khabbaz, H 2009, 'A Review of Ballast Characteristics, Geosynthetics, Confining Pressures and Native Vegetation in Rail Track Stabilisation', Transport Engineering in Australia, vol. 12, no. 1, pp. 25-36.
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Given the increased demand for freight transport for the mining and agriculture industries, and for greater public transport via trains due to increased fuel costs, heavier cyclic loading on existing tracks is now inevitable. Construction of rail tracks requires appropriate ballast specification to increase stability and performance of railway tracks. This paper aims to demonstrate and discuss some major aspects in relation to stabilisation of ballasted rail tracks overlying soft formation soils using geocomposites, prefabricated vertical drains and native vegetation. The use of geocomposites (ie. bonded geogrid-geotextile layers) for enhancing the performance of fresh and recycled ballast is described, with the aim of achieving reduced track settlement, increased resilient modulus and decreased ballast degradation. The effects of increasing the confi ning pressure on rail track behaviour, particularly with regard to particle breakage, have been studied using large-scale laboratory tests under cyclic loads. An elastoplastic stress-strain constitutive model for ballast was developed at the University of Wollongong, incorporating the degradation of particles as a particular feature, was introduced by capturing the breakage of particles during shearing, and the effects of cyclic loading on particle degradation and plastic deformation. In addition, numerical simulation using discrete element method has been carried out an assembly of irregular particles to investigate the mechanism of ballast breakage and to quantify breakage in relation to the ballast particle size distribution.
Kwok, NM, Ha, QP, Liu, D & Fang, G 2009, 'Contrast Enhancement and Intensity Preservation for Gray-Level Images Using Multiobjective Particle Swarm Optimization', IEEE TRANSACTIONS ON AUTOMATION SCIENCE AND ENGINEERING, vol. 6, no. 1, pp. 145-155.
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The contrast enhancement of gray-level digital images is considered in this paper. In particular, the mean image intensity is preserved while the contrast is enhanced. This provides better viewing consistence and effectiveness. The contrast enhancement is achieved by maximizing the information content carried in the image via a continuous intensity transform function. The preservation of image intensity is obtained by applying gamma-correction on the images. Since there is always a trade-off between the requirements for the enhancement of contrast and preservation of intensity, an improved multiobjective particle swarm optimization procedure is proposed to resolve this contradiction, making use of its flexible algorithmic structure. The effectiveness of the proposed approach is illustrated by a number of images including the benchmarks and an image sequence captured from a mobile robot in an indoor environment. © 2006 IEEE.
Li, Y, Li, J, Samali, B & Wang, J 2009, 'Design considerations and experimental studies on semi-active smart pin joint', Frontiers of Mechanical Engineering in China, vol. 4, no. 4, pp. 363-370.
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Hostile dynamic loadings such as severe wind storms, earthquakes, and sudden impacts can cause severe damage to many civil engineering structures. An intelligent structural system equipped with smart structural members that are controllable in real-time is an effective solution to structural damage and failure during such situations. Civil intelligent structures with controllable properties to adapt to any changes due to dynamic loadings can lead to effective protection of structures and their occupants. In this paper, design and testing of a semi-active magnetorheological (MR) pin joint, in which the moment resistance can be controlled in real-time by altering the magnetic field, is reported with the view of using it as a potential candidate for smart members in the development of intelligent structures. Design of prototype smart pin joints includes theoretical analysis related to the radius of the rotary plate, the property of MR fluids and the gap between the rotary plate and the casing based on the requirements of the dynamics of MR pin joints. FEM analysis was deployed to study the distribution of the magnetic field along the gap. It is found, from the theoretical analysis and experimental verification, that the MR pin joint with a diameter of 180 mm can produce a torque of up to 30 Nm, which meets requirements for semi-active members in a multi-storey prototype building model in the next stage of research and development. © Higher Education Press and Springer-Verlag 2009.
Raja, S, Thomas, PS, Stuart, BH, Guerbois, JP & O'Brien, C 2009, 'The estimation of pig bone age for forensic application using thermogravimetric analysis', JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY, vol. 98, no. 1, pp. 173-176.
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An accurate means of determining bone age is a goal for forensic scientists. In this study, thermogravimetric analysis (TGA) has been used to examine pig bone specimens of different post-mortem age. Analysis of bone in both air and nitrogen atmospheres reveals a decrease in total mass loss as the bones age. Two mass loss steps due to the decomposition of the organic bone components were observed and show decreasing trends with age for decomposition in an air atmosphere. In a nitrogen atmosphere the decomposition was observed to be more complex and age dependence of the mass loss for each step was not identified. The TGA data, however, demonstrates the potential of the technique as a means of estimating post-mortem age of forensic bone specimens.
Smallwood, A, Thomas, PS, Ray, AS & Simon, P 2009, 'Application of a Fickian model of diffusion to the dehydration of graded specimens of a precious Australian sedimentary opal derived from Coober Pedy', JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY, vol. 97, no. 2, pp. 685-688.
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A model developed for the estimation of the diffusion coefficient based on Fickian diffusion is applied to the dehydration of a Coober Pedy white play of colour (precious) opal using thermogravimetric analysis (TG). The model was originally applied to bulk and powdered opal (opal with no bulk). In this paper the opal was graded prior to TG analysis. The diffusion coefficient was calculated and is reported up to the critical point of water.
Vessalas, K, Ray, AS, Thomas, P, Sri Ravindrarajah, R, Joyce, PA & Haggman, J 2009, 'Pitchstone Fines - A New Naturally Occuring Pozzolan from North Queensland', Concrete Forum, vol. 2, no. 1, pp. 11-15.
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Global warming presents an ever-challenging battle to humankind, as emissions arising from industrially produced gteenhouse gases are predicted to alter the long-term climatic patterns of earth. Harmful environmental emissions arising during the manufactute of Portland cements (C) can be effectively reduced by incorporating siliceous-aluminous based supplementary cementitious materials (SCMs), as partial cement replacements. In Australia, mined pitchstone fines (PF), derived as waste material from expandable perlire production, area viable SCM for reducing cement consumption using an eco-friendly approach. This paper reports on the results of an experimental investigation into the pozzolanic activity of PP. Up to 40% cement was replaced with PF in mortar mixes. In addition, PP was used to partially replace sand. Strength activity index (SM) values for PP were evaluated using accelerated 28-day compressive strengths for all PP substitution levels, with flows and wet densities of mortar mixes reported.
Vessalas, K, Thomas, PS, Ray, AS, Guerbois, J-P, Joyce, P & Haggman, J 2009, 'Pozzolanic reactivity of the supplementary cementitious material pitchstone fines by thermogravimetric analysis', JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY, vol. 97, no. 1, pp. 71-76.
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Thermogravimetric (TG) analysis was applied to the characterisation of the pozzolanic reaction in mortars containing the supplementary cementitious materials (SCMs) pitchstone fines (PF) and fly ash (FA) as partial replacements for Portland cement (PC). TG analysis was used to determine the proportion of calcium hydroxide (CH) present from the hydration of the PC based on the dehydroxylation of the CH present in the blended PC-SCM mortars. The consumption of CH indicated that both SCMs underwent the pozzolanic reaction and that PF was found to compare favourably in its pozzolanic reactivity of FA, the industry and globally accepted standard artificial pozzolan.
Xu, YL, Zhang, J, Li, JC & Xia, Y 2009, 'Experimental Investigation on Statistical Moment-based Structural Damage Detection Method', Structural Health Monitoring, vol. 8, no. 6, pp. 555-571.
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Although vibration-based structural damage detection methods have demonstrated various degrees of success, the damage detection of civil structures still remains as a challenging task. The main obstacles include the insensitivity to local damage and the high sensitivity to measurement noise. A new structural damage detection method based on the statistical moments of dynamic responses of a structure has been recently proposed by the authors, and the numerical study manifested that the proposed method is sensitive to local structural damage but insensitive to measurement noise. The experimental investigation on this method is presented in this article. Three shear building models with and without damage were built and subjected to ground motions generated by a shaking table. The displacement and acceleration responses of each building model at each floor were recorded. The recorded ground motion and building responses as well as identified structural damping ratios were then used to identify damage locations and severities using the statistical moment-based damage detection method. The identified damage locations and severities were compared with the theoretical values. The comparison is found satisfactory, and the method proposed is effective and feasible.
Aoki, Y, Sri Ravindrarajah, R & Khabbaz, H 1970, 'Effect Of Fly Ash Performance Of Pervious Concrete', Ninth ACI International Conference on Superplasticizers and Other Chemical Admixtures in Concrete and Tenth ACI International Conference on Recent Advances in Concrete Technology and Sustainability Issues - SUPPLEMENTARY PAPERS, ACI International Conference on Superplasticizers and Other Chemical Admixtures in Concrete and Tenth ACI International Conference onRecent Advances in Concrete Technology and Sustainability Issues, ACI International Conference, Seville, Spain, pp. 511-520.
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Production of good quality pervious concrete is necessary to meet specification requirements for the construction of durable concrete pervious pavements. This paper reports and discusses the results of an experimental investigation into the physical and engineering properties ofpervious concrete having varying amounts of fly ash as the cement replacement material. The following properties were studied: porosity density, compressive strength weight loss on drying, free drying shrinkage and water permeability. The results thowed that porosity has significant effect on compressive strength and permeability of pervioos concrete. Replacement of cement with fly ash up to 50%, by mass ofbinder, had no significant effect on the water permeability and shrinkage ofshe pervious concrete, although marginal effect on strength was noticed.
Choudhury, D & Nimbalkar, S 1970, 'Seismic stability of tailings dam by using pseudo-dynamic method', Proceedings of the 17th International Conference on Soil Mechanics and Geotechnical Engineering: The Academia and Practice of Geotechnical Engineering, pp. 1542-1545.
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Seismic stability of tailings dams and embankments is an important topic which needs the special assessments by the researchers as it is mainly governed by the safety concerns. Several researchers in the past had attempted to investigate the seismic stability of earthen dams and embankments by using conventional pseudo-static method of analysis. However, the crude estimate of finding the approximate seismic acceleration makes the pseudo-static approach too conservative to adopt in the stability assessment. Although a few researchers in the recent past highlighted the limitations and drawbacks of the pseudo-static approach, there are very limited studies being reported worldwide for the seismic stability assessment of earthen dams and embankments by using alternative methods of analysis. In this paper, a recently developed and modified pseudo-dynamic method of analysis is used to compute the seismic inertia forces acting on the sliding wedge of the tailings dam by considering the effects of time of seismic accelerations, phase differences in the propagating shear and primary waves in the soil during an earthquake, frequency of earthquake excitation etc. with the horizontal and vertical seismic accelerations. The factor of safety decreases with increase in the seismic accelerations and phase difference in body waves. Influence of various parameters such as seismic acceleration coefficients, period of lateral shaking on seismic stability of tailings dam are studied under harmonic seismic loading conditions for both empty and full water cases. Present results are compared with the pseudo-static based solutions to validate the findings of the pseudo-dynamic method of analysis. © 2009 IOS Press.
Christie, D, Nimbalkar, S & Indraratna, B 1970, 'The performance of rail track incorporating the effects of ballast breakage, confining pressure and geosynthetic reinforcement', Bearing Capacity of Roads, Railways and Airfields - Proceedings of the 8th International Conference on the Bearing Capacity of Roads, Railways and Airfields, 8th International Conference on the Bearing Capacity of Roads, Railways and Airfields, CRC Press, Champaign, IL, pp. 5-24.
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Rail tracks are often placed on ballast which offers the desirable resiliency to cyclic loads. However ballasted beds need periodic maintenance due to deformation and degradation associated with breakage and fouling. A proper understanding of load transfer mechanisms and their effect on ballast breakage are prerequisites for minimizing maintenance costs. Recycled ballast is a cheaper and environmentally viable option but its strength characteristics need to be investigated beforehand. This paper demonstrates the analytical, numerical and laboratory investigations carried out to investigate the geotechnical behavior of ballast, including shear strength, ballast breakage, and confining pressure. The potential use of geosynthetics for improving the stability and drainage of railway tracks under high monotonic and cyclic loading is also studied. Field tests were carried out to measure the in-situ stresses of ballast on a section of instrumented track funded and built by RailCorp, Australia. © 2009 Taylor & Francis Group, London.
Dalvand, H, Nguyen, HT & Ha, QP 1970, 'Design of Second-Order Sliding Mode Controllers for MR Damper-Embedded Smart Structures', Proceedings of the 2009 International Symposium on Automation and Robotics in Construction (ISARC 2009), 26th International Symposium on Automation and Robotics in Construction, International Association for Automation and Robotics in Construction (IAARC), Austin USA, pp. 332-340.
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Design of a current controlled system for MR damper-embedded civil structures
Ding, GK & Ge, J 1970, 'Green revolution - a challenge to improve environmental performance of existing housing stocks', 2009 Conference on Green Building: Towards Eco-City, Conference on Green Building: Towards Eco-City, Architecture and Building Research Institute, Ministry of the Interior, Taipei, Taiwan, pp. 135-149.
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Climate change is one of the most pressing issues facing Australia today. This is a challenge and responsibility that is shared by all Australian households. Improvements to energy and water efficiency of houses can significantly cut greenhouse gas emissions and reduce utility bills. In July 2004 the New South Wales (NSW) government introduced the Building Sustainability Index (BASIX) to assess potential performance of a dwelling against a set of pre-determined criteria. Housing construction in NSW is the first in Australia to be subjected to mandatory sustainability requirements. BASIX is an online assessment tool which sets scores required to obtain development approval in new residential projects. BASIX is mandated only to improve environmental performance of new residential buildings and does not attempt to improve environmental performance of existing housing stocks which continue to consume natural resources and pollute the environment. Existing houses represent approximately 98% of residential building stocks in NSW and any improvement to these dwellings will have a profound impact on reducing the negative effects of the environment. This paper examines the sustainable upgrading strategies in improving environmental performance of three existing single dwellings in meeting the minimum BASIX requirements. This paper presents an economic analysis of sustainable upgrading using Net Present Value. The results suggest that sustainable upgrading of existing housing stocks is feasible and the scheme will be more attractive if the payback period is reduced with further government financial assistance.
Ge, J & Ding, GK 1970, 'Energy efficient and water reduction programs on households in Australia', 2009 Conference on Green Building: Towards Eco-City, Conference on Green Building: Towards Eco-City, Architecture and Building Research Institute, Ministgry of the Interior, Taiwan, pp. 56-66.
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In 2009, the Australian government has formulated strategies to provide $3.9 billion Energy Efficient Home Package for cutting energy waster and $12.9 billion Water for the Future plan for reducing the use of drinking water, aim of tackling climate change and reducing green house emission. Under the strategies, there are incentive schemes for households of the existing homes, which include a) rebates of up to $500 for installing a new rainwater tank or a permanent grey water treatment system; b) offers of up to $1,600 ceiling insulation or installation of solar hot water system or an assistance of up to $1,000 installing insulation in private rental properties; c) cash rebates of up to $8,000 for the installation of solar photovoltaic systems on homes; and d) providing detailed, quality household sustainability assessments and green renovations packs to Australian households as well as access to low interest Green Loans of up to $10,000 each to make existing homes more energy and water efficient. This paper studies whether the incentive schemes motivate households and how much attraction of the schemes for households. The paper starts to review government policies for home energy efficient and water reduction programs in Australia and compare schemes provided by other countries. Case studies on incomes and expenses for a standard family, costs and benefits, as well as elements impact on households of taking the government incentive schemes are examined. The paper comments on the current incentive programs provided by the government and argue that education on attitude toward saving electricity and water should be one of the important parts of the programs.
Ge, JX & Ding, GKC 1970, 'Cost Effective and Sustainable?: Photovoltaic (PV) Rebate Program in Australia', 2009 International Conference on Management and Service Science, 2009 International Conference on Management and Service Science (MASS), IEEE, Beijing, China, pp. 1-4.
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The Australian Government has recently announced a Renewable Energy Target (RET) scheme to provide up front payments of $8,000 for around 25,250 households of income less than $100,000 per year installing a 150 watt solar panel system starting on 01 July 2009 using $202 million taxpayers' money. The scheme has not included households' with incomes greater than $100,000, nor developers who produce new houses. Whether the policies are effective and sustainable is arguable. This paper examines policies designed to encourage households to install solar panel system in Australia and demonstrates reasons for supporting developers to build green houses using Net Present Value (NPV) analysis in a case study. The findings suggest that the government should support installation of solar systems by both households and the developers. ©2009 IEEE.
Gerber, C & Crews, K 1970, 'Timber stressed-skin panels: Design guidelines for Australian practice', AUSTRALIAN JOURNAL OF STRUCTURAL ENGINEERING, Australian Structural Engineering Conference, TAYLOR & FRANCIS AS, Melbourne, pp. 207-216.
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Hongsheng, H, Jiong, W, Suxiang, Q, Yancheng, L & Xuezheng, J 1970, 'Investigation on controllability of a Magnetorheological gun recoil damper', 2009 International Conference on Information and Automation, 2009 International Conference on Information and Automation (ICIA), IEEE, pp. 1044-1049.
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Its primary purpose of this study is to provide a comprehensive investigation on the controllability of a Magnetorheological (MR) gun recoil damper. Performances of MR damper under random load, mainly in the transportation applications, seismic protection in civil engineering and windrain- induced load in Cable Bridge, have been well investigated by many researchers. However, little research has been focused on the dynamic performance and its controllability of MR damper under impact load. At present, a systematic architecture has still not been formed, including its structure design, dynamicmodelling and controlling method of a MR damper subjected to impact load. In this paper, the research is developed and aims at the MR gun recoil damper. To evaluate its controllability of a MR gun recoil damper, a test rig which uses a closed bump to produce an impact load is developed. A novel large-scale singleended MR damper without the accumulator is used as the specimen. First, impact tests were done to evaluate the response time of the special designed long-stroke MR gun recoil damper, corresponding to the step signal of the operating current. Then, three revised control strategies, including on-off control method, PID control method, adaptive fuzzy control method, were investigated to confirm its controllability of the MR damper under impact load. Compared with on-off control and PID control policy, it is indicated by test results that this developed MR gun recoil damper has a bette r controllability using the adaptive fuzzy control policy. © 2009 IEEE.
Hongsheng, H, Jiong, W, Suxiang, Q, Yancheng, L, Xuezheng, J & IEEE 1970, 'Investigation on Controllability of a Magnetorheological Gun Recoil Damper', ICIA: 2009 INTERNATIONAL CONFERENCE ON INFORMATION AND AUTOMATION, VOLS 1-3, 2nd International Conference on Smart Materials and Nanotechnology in Engineering, SPIE-INT SOC OPTICAL ENGINEERING, Weihai, PEOPLES R CHINA, pp. 1023-1028.
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Hongsheng, H, Juan, W, Jiong, W, Suxiang, Q & Yancheng, L 1970, 'Investigation on modeling and controability of a magnetorheological gun recoil damper', SECOND INTERNATIONAL CONFERENCE ON SMART MATERIALS AND NANOTECHNOLOGY IN ENGINEERING.
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Hongsheng, H, Juan, W, Jiong, W, Yancheng, L & Xuezheng, J 1970, 'Investigation on its properties for MR damper under high impact load', ISTM/2009: 8TH INTERNATIONAL SYMPOSIUM ON TEST AND MEASUREMENT, VOLS 1-6, 8th International Symposium on Test Measure, INTERNATIONAL ACADEMIC PUBLISHERS LTD, Chongqing, PEOPLES R CHINA, pp. 2186-2189.
Khabbaz, H & Indraratna, B 1970, 'Development of a Smart Tool for Capturing Novel Advancement in Ballasted Rail Track Substructure', Congress e-Proceedings, 8th International Congress on Civil Engineering, International Congress on Civil Engineering, Department Of Civil And Environmental Engineering Of Shiraz University, Shiraz, Iran, pp. 1-8.
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The obligation of keeping a competitive edge against other means of transportation has increased the pressure on the railway industry to improve its efficiency and decrease the maintenance costs. In this paper, several innovative solutions are presented to improve the rail track foundations including optimum particle ballast grading and confining pressure as well as stabilising tracks overlying soft soils employing different techniques. A smart tool for predicting the performance of rail track substructure is also developed. This smart tool provides the user optimum construction parameters and required geotechnical properties according to various subgrade conditions, train loads and speeds.
Kwok, NM, Ha, QP & Fang, G 1970, 'Effect of color space on color image segmentation', PROCEEDINGS OF THE 2009 2ND INTERNATIONAL CONGRESS ON IMAGE AND SIGNAL PROCESSING, VOLS 1-9, International Congress on Image and Signal Processing, IEEE, Inc., Tianjin China, pp. 1369-1373.
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A study of color image segmentation with its dependence on color space representation is presented. Segmentation has been one of the basic procedures in image processing. Because of the three-fold increase in color signal dimension as compared to black-and-white images, an advantage resulting from the choice of color space representation could be taken to enhance the performances of processes such as segmentation and feature matching. However, the choice of a particular color space is still largely application dependent. This work attempts to study a number of popular color space schemes on the basis of the maximum information that the space is able to convey to the segmentation process. Thus, a reduction in the complexity of the segmentation procedure is achievable when it is operating on a single color space domain. The amount of information contained in the segmented objects is adopted as a measure to determine the segmentation rule. Several aerial images over planted fields are employed in experiments and their satisfactory segmentation results are used to conclude the study.
Manamperi, P, Wije, A, Perumynar, S, Aboura, K, Samali, B & Crews, KI 1970, 'Stochastic Processes for Bridge Deterioration Assessment', 7th Austroads Bridge Conference - Bridges linking communities, 7th Austroads Bridge Conference - Bridges linking communities, Austroads, Auckland, New Zealand, pp. 1-9.
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The Roads and Traffic Authority of NSW (RTA) has over 5000 bridges in the road network under its jurisdiction. These structures were built from different materials, at different times, under different design codes with different articulations and are exposed to different environments. The levels and rate of deterioration of these structures vary greatly and are dependent on the effects of age, environment, magnitude and frequency of heavy traffic and construction quality. These factors make the management of these structures a real challenge to the RTA. In order for the RTA to improve the management of these bridge assets, the RTA is working with the University of Technology Sydney (UTS) to develop a statistical model to predict the future condition of bridges using the condition inspection data collected over the last 15 years. This paper will report on findings of the study conducted to identify a suitable model for prediction of future condition of bridges based on the available inspection data. The gamma process is considered in the development of the predictive model for the life of bridge components. In addition to the gamma process application, observations are made on the distribution of deterioration at different times that could lead to other stochastic processes for modeling time-dependent structural deterioration.
Raja, S, Stuart, BH & Thomas, P 1970, 'The development of analytical techniques for the determination of forensic bone age', 5th European Academy of Forensic Science Conference Book of Abstracts, 5th European Academy of Forensic Science Conference, Glasgow, pp. 1-1.
Raja, S, Thomas, P & Stuart, BH 1970, 'A study of storage conditions and treatments for forensic bone specimens using thermogravimetric analysis', Medicta 2009 Book of Abstracts, 9th Mediterranean Conference on Calorimetry and Thermal Analysis, Marseille.
Raja, S, Thomas, P, Stuart, BH & O'Brien, C 1970, 'Pyrolysis gas chromatography - mass spectrometry analysis for the estimation of pig bone age', 21st Congress of the International Academy of Legal Medicine Abstracts, Congress of the International Academy of Legal Medicine, Lisbon.
Ray, AS, Connan, H, Liu, B & Thomas, P 1970, 'Alumina-Silica Rich Clay Brick Waste In Hydrothermally Treated Cement-Based Construction Products', Proceedings of the 34th Conference on Our World In Concrete & Structures, Conference On Our World In Concrete & Structures, CI-Premier Conference Organisation, Singapore, Singapore, pp. 289-296.
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An urgent need for creative, sustainable approaches, which minimise the environmental impact of conventional Portland Cement (PC) -based construction materials, is recognised throughout the world. In recent years intensive research has been directed to the use of alumino-silicate materials to produce blended PC. The reduction of CO2 emissions, through the minimisation of PC consumption in the manufacture of PC-based construction products, and utilisation of industrial byproducts, to limit environmental impact, are the principal drivers of this worldwide activity. A number of supplementary cementitious materials (SCMs) containing alumina and silica such as fly ash, granulated blast furnace slag and silica fume are well known additives for the production of blended PCs due to their pozzolanic properties. The potential of other by-products such as those from the construction and demolition industry are less known however, even though they represent an excellent source of reactive alumina and silica-rich material. This paper deals with fired clay bricks (CB), generated as a waste product from construction and demolition activities, and their value as an additive in the manufacture of PC-based construction products. The research findings reported in this paper are from laboratory scale experiments conducted under hydrothermal conditions in an autoclave where fmely ground Cl3 waste was incorporated in the mixes. From a combination of analytical techniques including X-ray Diffraction, Differential Thermal Analysis, Scanning Electron Microscopy and solid-state Nuclear Magnetic Resonance, it was established that the aluminosilicate phase in the fired clay bricks promoted the development of the tobermorite, the principal binder in most calcium silicate products under hydrothermal conditions. The use of CB waste as a cement replacement for the manufacture of these products was also demonstrated as a viable option.
Saleh, A & Gardner, AP 1970, 'Digital animations as a visual learning tool for Structural Analysis', Proceedings of the 20th Australasian Association for Engineering Education Conference, Annual Conference of Australasian Association for Engineering Education, The School of Mechanical Engineering, The University of Adelaide, Adelaide, Australia, pp. 229-236.
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A number of digital animation clips have been developed to explore the effectiveness of their use in teaching of the subject Structural Analysis at the University of Technology, Sydney.The subject Structural Analysis is perceived by most students as challenging not only because of the theory and analysis concepts covered, but also because in its application it is difficult to visualise how structures behave when subjected to loads. The animation clips that were developed bring âmovement and lifeâ to structures that are traditionally presented in textbooks as static. It is anticipated that this will assist students to visualise the behaviour of structures and to better understand difficult concepts and methods taught in the subject. The intended uses of the animations are (1) in-class demonstration of behaviour of structures and methods of structural analysis and (2) as a self learning tool for students. This paper will present examples of the animations, how they have been used in teaching of Structural Analysis and feedback from students on their effectiveness.
Sri Ravindrarajah, R & Lyte, MC 1970, 'Properties of adjusted density high-performance concrete', Future in Mechanics of Structures and Materials, Proceedings of the 20th Australasian Conference on the Mechanics of Structures and Materials, Australasian Conference on the Mechanics of Structures and Materials, CRC Press, Taylor & Francis Group, Toowoomba, Australia, pp. 351-355.
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Lightweight expanded polystyrene a well known material to absorb impact energy is being used to produce adjusted density concrete having enhanced impact energy absorption capacity concrete. Two structural concrete grade 30 and 45 MPa normal weight concrete and lightweight polystyrene concrete were tested for their impact response under 75 kg weight test through 462mm drop. The impact response of concrete was monitored through load-time plot. Peak load and contact time are considered as important measurable quantities in identifying the energy absorbing capacity of concrete. The results showed that for a given structural grade the concrete containing expanded polystyrene aggregate out-performed the nonnal weight concrete in its impact resistance. Under the tested impact loading condition, polystyrene concrete having the compressive strength of 30 MPa showed 28% increase in the contact time and 18% reduction in the peak load compared to the similar grade normal weight concrete
Sri Ravindrarajah, R & Mansour, M 1970, 'Current Practices on Cement Rendering In Australia', Proceedings of the 1st International Conference on Rehabilitation and Maintenance in Civil Engineering (ICRMCE), 1st International Conference on Rehabilitation and Maintenance in Civil Engineering (ICRMCE), Sebelas Maret University, Solo, Indonesia, pp. 39-48.
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Cement rendering is widely used in Australia in the construction of new buildings and to rehabilitate the existing old buildings. Rendering buildings are normally carried out by tradesmen with varying degree of experience. The quality of the rendering is significantly varied and failure of render is not uncommon. This paper reports the existing practice of cement rendering in Australia and highlights the factors influencing the causes of poor performance of cement rendering. Interviews were conducted with renders, builders, clients and architects in relation to their experience on rendering practices and the results of these interviews are reported. A case study on the performance of rendered sea wall is reported.`
Vessalas, K, Ray, AS, Thomas, P, Joyce, PA & Haggman, J 1970, 'Assessment of chemical durability of pitchstone fines in Portland cement blended mortars', Concrete Solutions 09: Adding value in changing climates - Proceedings of the 24th Biennial Conference of the Concrete Institute of Australia, Concrete Solutions 09: Adding value in changing climates - 24th Biennial Conference of the Concrete Institute of Australia, Concrete Institute of Australia, Sydney, Australia, pp. 1-9.
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The use of supplementary cementitious materials (SCMs) as partial replacement of Portland cement (PC) is an effective way of reducing the consumption of PC. This investigation is aimed at assessing some chemical durability aspects of PC-SCM blended mortars containing pitchstone fines (PF) and fly ash (FA) at 20% and 40% replacement levels of PC. Hardened mortar cubes containing these two pozzolanic SCMs and a control mortar containing 100% PC were prepared and pre-aged in lime-saturated water for 28-days. These specimens were then immersed into 1M solution of sodium sulphate (Na2SO4) and their mass and pH recorded after 28-days and 56-days. Specimens were also immersed in deionised water as a control environment for comparison of mass change and pH. In the case of PF, data from 1M Na2SO4 immersion demonstrate increasing substitution rate provides lower mass gain. In contrast, increasing replacement rate of PC by FA in 1M Na2SO4 demonstrates higher mass gain comparable to 100% PC.
Wang, JJ, Hu, G, Huang, S & Dissanayake, G 1970, '3D landmarks extraction from a range imager data for SLAM', Proceedings of the 2009 Australasian Conference on Robotics and Automation, ACRA 2009, Australasian Conference on Robotics and Automation, Australian Robotics and Automation Association Inc., Sydney, Australia, pp. 1-8.
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This paper introduces a new 3D landmark extraction method using the range and intensity images captured by a single range camera. Speeded up robust features (SURF) detection and matching is used to extract and match features from the intensity images. The range image information is used to transfer the selected 2D features into 3D points. The range measurement bias and uncertainty of the range camera are analysed, and their models are developed for improving the range estimation. After outliers' detection and removal using random sampling consensus (RANSAC), reliable 3D points are obtained. 3D landmarks for simultaneous localisation and mapping (SLAM) are selected from the 3D points considering several factors, such as the uncertainty and geometry of their locations. Because of the availability of the SURF descriptor, the data association in SLAM has been performed using both the geometry and the descriptor information. The proposed method is tested in unstructured indoor environments, where the range camera moves in six degrees of freedom. Experimental results demonstrate the success of the proposed 3D landmark extraction method for SLAM.
Wang, JJ, Kodagoda, S & Dissanayake, G 1970, 'Vision aided GPS/INS system for robust land vehicle navigation', 22nd International Technical Meeting of the Satellite Division of the Institute of Navigation 2009, ION GNSS 2009, pp. 195-204.
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This paper introduces a new approach for improving land vehicle navigation by integrating a digital camera with a GNSS receiver and a MEMS INS, to provide seamless robust navigation solutions in urban environment. As a camera has the ability to detect surrounding environment, it can measure its relative position and direction to the surrounding objects. The integration of heterogeneous sensors with very different characters, such as GNSS, INS and image in this approach, can complement each other and provide cost-effective and robust navigation solutions. In the proposed system, INS is selected as the reference navigation sensor as it provides complete navigation solutions without disruptions. The navigation errors caused by its inherent nonlinear and time-varying characteristics can be corrected by the camera and GNSS. Vision based navigation (VBN) is one of the fundamental issues in computer vision and is relatively well developed. In this paper mono vision (MV) based navigation technologies are merged with GNSS and INS measurement, termed as GNSS/INS/MV (GlMV) integration. VBN is at the core of proposed robust navigation system, in which a relative range scale factor is estimated by continuously applying structure-from-motion in the MV navigation. Due to the complexity of multi-sensor integration, it needs an optimal sensor fusion framework with reliable system design, modeling and quality control procedures. The proposed sensor fusion method consists of two local and one master data fusion units, based on extended Kalman filter and fuzzy logic. It takes the advantages of federate architecture, and can select using either GNSS or VBN navigation solutions for PNS correction according to their quality. GNSS/INS integration is the mainstream for navigation when the vehicle travels in an open area with good GNSS signal. At the same time, the modeling parameters of INS and camera are estimated. When the system is navigating in areas with weak GNSS signals,...
Yu, Y, Kodagoda, S & Ha, QP 1970, 'Relative Distance Estimation for Indoor Multi-Robot Control Using Monocular Digital Camera', Proceedings of the 3rd International Workshop on Artificial Intelligence in Science and Technology, International Workshop on Artificial Intelligence in Science and Technology, The University of Tasmania, Hobart, Australia, pp. 1-6.
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Distance measurement methodologies based on the digital camera usually require extensive calibration routines, some are even derived from complicated image processing algorithms resulting in low picture frame rates. Particularly, in a dynamic camera system, due to the unpredictability of intrinsic and extrinsic parameters, the reliable measuring results are highly dependent on the accuracy of extra sensors. In this paper, a simple algorithm for relative distance estimation is proposed for multi-robot control with a monocular digital camera. Reasonable accuracy is achieved by judging the 2D perspective projection image ratio (PPIR) of robots' labels on a TFT-LCD (Thin Film Transistor-Liquid Crystal Display) monitor without any additional sensory cost and complicated calibration effort. Further, the algorithm does not contain any trigonometric functions so that it can be easily implemented on an embedded system using the field programmable gate array (FPGA) technology.
Yu, Y-H, Ha, QP & Kwok, NM 1970, 'Chip-based Design for Real-time Moving Object Detection using a Digital Camera Module', PROCEEDINGS OF THE 2009 2ND INTERNATIONAL CONGRESS ON IMAGE AND SIGNAL PROCESSING, VOLS 1-9, International Congress on Image and Signal Processing, IEEE Inc, Tianjin China, pp. 1993-1997.
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Design of a FPGA-based colour detection system for detection of moving objects.
Zhang, J, Xu, YL, Xia, Y & Li, JC 1970, 'Statistical moment-based damage detection of building structures', Structural Health Monitoring of Intelligent Infrastructure - Proceedings of the 4th International Conference on Structural Health Monitoring of Intelligent Infrastructure, SHMII 2009.
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This paper presents a novel structural damage detection method based on the statistical moments of dynamic responses of building structures under random excitation. The principle of the method is put forward in terms of a single-degree-of-freedom (SDOF) system and then extended to multi-degree-of- freedom (MDOF) systems with resort to the least-squares method. The numerical studies on a shear building structure manifest that the proposed method is sensitive to local structural damage but insensitive to measurement noise. Furthermore, the proposed method was experimentally examined to assess its reliability in practical applications. Eight damage scenarios were designed and a series of shaking table tests were conducted on three shear building models before and after damage under white noise or color noise ground excitations. The experimental results matched the theoretical values well and the statistical moment-based damage detection method is demonstrated to be feasible and accurate.
