Akgun, A, Kıncal, C & Pradhan, B 2012, 'Application of remote sensing data and GIS for landslide risk assessment as an environmental threat to Izmir city (west Turkey)', Environmental Monitoring and Assessment, vol. 184, no. 9, pp. 5453-5470.
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Akgun, A, Sezer, EA, Nefeslioglu, HA, Gokceoglu, C & Pradhan, B 2012, 'An easy-to-use MATLAB program (MamLand) for the assessment of landslide susceptibility using a Mamdani fuzzy algorithm', Computers & Geosciences, vol. 38, no. 1, pp. 23-34.
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Althuwaynee, OF, Pradhan, B & Lee, S 2012, 'Application of an evidential belief function model in landslide susceptibility mapping', Computers & Geosciences, vol. 44, pp. 120-135.
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Aoki, Y, Ravindrarajah, RS & Khabbaz, H 2012, 'Properties of pervious concrete containing fly ash', ROAD MATERIALS AND PAVEMENT DESIGN, vol. 13, no. 1, pp. 1-11.
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Pervious concrete isoneofthe most effective pavement materialsto addressanumber ofimportant environmental issues, such as recharging groundwater and reducing stormwater runoff. In this paper, the findings of an experimental investigation on properties of pervious concrete are reported and discussed. The amount of general purpose Portland cement has been reduced by introducing fly ash as a cementitious agent in pervious concrete samples. The properties of various pervious concrete samples including density, porosity, compressive strength, water permeability and drying shrinkage have been carefully measured. In addition, the relationships among these properties are explored. According to the results, high porosity samples indicated higher permeability, whereas their compressive strength was reduced. There was no significant difference between properties of pervious concrete samples containing fly ash and those samples comprising only cement as a cementitious agent. Hence, environmentally friendly pervious concrete with fly ash can be produced in lieu of conventional pervious concrete. © 2012 Taylor & Francis.
Ashurov, R, Butaev, A & Pradhan, B 2012, 'On Generalized Localization of Fourier Inversion Associated with an Elliptic Operator for Distributions', Abstract and Applied Analysis, vol. 2012, pp. 1-13.
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We study the behavior of Fourier integrals summed by the symbols of elliptic operators and pointwise convergence of Fourier inversion. We consider generalized localization principle which in classicalLpspaces was investigated by Sjölin (1983), Carbery and Soria (1988, 1997) and Alimov (1993). Proceeding these studies, in this paper, we establish sharp conditions for generalized localization in the class of finitely supported distributions.
Bu, GP, Lee, JH, Guan, H, Loo, YC & Blumenstein, M 2012, 'Long-Term Performance of Bridge Elements Using Integrated Deterioration Method Incorporating Elman Neural Network', Applied Mechanics and Materials, vol. 204-208, pp. 1980-1987.
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Currently, probabilistic deterioration modeling techniques have been employed in most state-of-the-art Bridge Management Systems (BMSs) to predict future bridge condition ratings. As confirmed by many researchers, the reliability of the probabilistic deterioration models rely heavily on the sufficient amount of condition data together with their well-distributed historical deterioration patterns over time. However, inspection records are usually insufficient in most bridge agencies. As a result, a typical standalone probabilistic model (e.g. state-based or time-based model) is not promising for forecasting a reliable bridge long-term performance. To minimise the shortcomings of lacking condition data, an integrated method using a combination of state- and time-based techniques has recently been developed and has demonstrated an improved performance as compared to the standalone techniques. However, certain shortcomings still remain in the integrated method which necessities further improvement. In this study, the core component of the state-based modeling is replaced by an Elman Neural Networks (ENN). The integrated method incorporated with ENN is more effective in predicting long-term bridge performance as compared to the typical deterioration modeling techniques. As part of comprehensive case studies, this paper presents the deterioration prediction of 52 bridge elements with material types of Steel (S), Timber (T) and Other (O). These elements are selected from 94 bridges (totaling 4,115 inspection records). The enhanced reliability of the proposed integrated method incorporating ENN is confirmed.
Bui, DT, Pradhan, B, Lofman, O, Revhaug, I & Dick, OB 2012, 'Application of support vector machines in landslide susceptibility assessment for the Hoa Binh province (Vietnam) with kernel functions analysis', iEMSs 2012 - Managing Resources of a Limited Planet: Proceedings of the 6th Biennial Meeting of the International Environmental Modelling and Software Society, pp. 382-389.
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The main objective of this study is to investigate the potential application of support vector machines (SVM) with kernel functions analysis for spatial prediction of landslides in the Hoa Binh province, Vietnam. A landslide inventory map that accounts for landslides that occurred during the last ten years was constructed using data from various sources. The landslide inventory was randomly divided into a training dataset 70% for building the models and the remaining 30% for the validation of the models. Ten landslide conditioning factors, such as slope angle, aspect, relief amplitude, lithology, soil type, landuse, distance to roads, distance to rivers, distance to faults and rainfall were prepared. During the model building process, four different SVM kernel functions (linear, polynomial, radial basic function, and sigmoid) were employed and four landslide susceptibility maps were constructed. Using the prediction rate method, the validation was performed by using landslide locations, which were not utilized during the model building. The validation results showed that the area under the curve (AUC) for landslide susceptibility maps produced by the SVM linear function, SVM polynomial function, SVM radial basic function, and SVM sigmoid function are 0.956, 0.956, 0.952, and 0.945 respectively. It indicates that the four landslide models seem to have performed well. Compared with the logistic regression (AUC =0.938) and Bayesian neural network model (AUC 0.903), the accuracy of the SVM landslide models in this study (using radial basic function and polynomial function) are slightly better. The result shows that SVM is a powerful tool for landslide susceptibility mapping at a regional scale. These maps can be very useful for natural hazards assessment and for land use planning.
Bui, DT, Pradhan, B, Lofman, O, Revhaug, I & Dick, OB 2012, 'Landslide susceptibility assessment in the Hoa Binh province of Vietnam using Artificial Neural Network', Geomorphology. doi, vol. 10, p. 1016.
Chai, J, Sheng, D, Carter, JP & Zhu, H 2012, 'Coefficient of consolidation from non-standard piezocone dissipation curves', Computers and Geotechnics, vol. 41, pp. 13-22.
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Cheng, S, Ji, JC & Zhou, J 2012, 'Second-order consensus of multiple non-identical agents with non-linear protocols', IET CONTROL THEORY AND APPLICATIONS, vol. 6, no. 9, pp. 1319-1324.
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The second-order consensus of multiple interacting non-identical agents with non-linear protocols is studied in this article. Firstly, it is shown that all agents with different non-linear dynamics can achieve consensus without a leader. Secondly, an explicit expression of the consensus value is analytically developed for the group of all agents. Thirdly, for the consensus of multiple agents with a leader, it is proved that each agent can track the position and velocity of the leader, which are different from those of the follower agents. Finally, numerical simulations are given to illustrate the theoretical results. © 2012 The Institution of Engineering and Technology.
Dallo, YAH & Wang, Y 2012, 'Discussion of “Assessing the Potential of Internal Erosion and Suffusion of Granular Soils” by Buddhima Indraratna, Vo Trong Nguyen, and Cholachat Rujikiatkamjorn', Journal of Geotechnical and Geoenvironmental Engineering, vol. 138, no. 6, pp. 772-773.
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Delgado-Ramos, F & Poyatos, JM 2012, 'Discussion of “Assessing the Potential of Internal Erosion and Suffusion of Granular Soils” by Buddhima Indraratna, Vo Trong Nguyen, and Cholachat Rujikiatkamjorn', Journal of Geotechnical and Geoenvironmental Engineering, vol. 138, no. 6, pp. 773-775.
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Dom, NC, Latif, ZA, Ahmad, AH, Ismail, R & Pradhan, B 2012, 'Manifestation of GIS tools for spatial pattern distribution analysis of dengue fever epidemic in the city of Subang Jaya, Malaysia', EnvironmentAsia, vol. 5, no. 2, pp. 82-92.
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Dengue has now emerged as one of the major public health problems in Malaysia. It was first reported in 1901 in Penang and since then the disease has become endemic concentrating mostly in urban areas. This study used the temporal-spatial model to determine high risk areas for dengue outbreak by measuring three temporal risk characteristics (i.e. frequency, duration and intensity) in order to define the severity and magnitude of outbreak transmission. This study examined a total of 4,651 confirmed dengue fever cases, geo-coded by address in the city of Subang Jaya between January 2006 and December 2009. The values of the three indices were considered high in a spatial unit when their standard values were positive. Measurement of the three temporal risk indices found that there were areas with significant high value for each of the temporal indices. This suggested that areas within Subang Jaya Municipality had different temporal characteristics for dengue occurrence. The utilization of three risk measures enabled to identify higher-risk areas for the occurrence of dengue fever. Even though case notification data are subjected to bias, this information is available in the health services and can lead to important conclusions, recommendations and hypotheses. As a recommendation, the temporal risk indices can be utilized by public health officials to characterize dengue rather than relying on the traditional case incidence data.
Fatahi, B, Basack, S, Premananda, S & Khabbaz, H 2012, 'Settlement prediction and back analysis of Young's modulus and dilation angle of stone columns', Australian Journal of Civil Engineering, vol. 10, no. 1, pp. 67-80.
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Ground improvement using stone columns is one of the most suitable methods for deformation control of soft soils. The use of stone columns can improve the bearing capacity, reduce settlement, accelerate consolidation process and enhance slope stability as ivell as resistance to liquefaction. Settlement prediction of the ground influenced by the large stiffness difference between the columns and the surrounding soil and the induced arching is discussed in this paper. Plate load test is one of the common methods to be used for quality control of stone column reinforced ground. The test results can be used to back calculate some of the design parameters of the stone column. A finite element based procedure to estimate the Young's modulus and dilation angle o f stone column material using plate load test residts is proposed. The employed finite element model is axisymmetric and suitable for a cylindrical stone column. The field measurements after calibration have been in good agreement with numerical results for predicting deformations. The procedure developed in this study can be adopted by practicing engineers to estimate the Young's modulus and dilation angle of stone columns by conducting a plate load test. © Institution of Engineers Australia, 2012.
Fatahi, B, Khabbaz, H & Fatahi, B 2012, 'Mechanical characteristics of soft clay treated with fibre and cement', GEOSYNTHETICS INTERNATIONAL, vol. 19, no. 3, pp. 252-262.
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In this study, the influence of three types of fibre - polypropylene, recycled carpet and steel - on the mechanical properties of cement-treated clay is investigated. Cement-treated clay specimens were prepared with cement contents of 5%, 10% and 15% by weight of dry soil, and cured for 14 days. To investigate and understand the influence of different fibre types and contents, three different percentages of fibre content were adopted. The results of unconfined compression tests on 90 cylindrical samples of cement-treated clay with varied cement and fibre contents are analysed to discern the relationships between these parameters and the key mechanical properties, including unconfined compressive strength and stiffness of treated soil. Furthermore, indirect tension test results of a further 90 treated soil samples have been used to determine the influence of fibre and cement content on the tensile strength of the treated soil. The fibre reinforcement increases the peak compressive strength. The addition of fibres increases the residual strength and changes the brittle behaviour of the cement-treated clay to that of a more ductile material. The tensile strength of the cement-treated clay is increased by adding carpet and steel fibres, but small quantities of polypropylene fibres do not influence the tensile strength. © 2012 Thomas Telford Ltd.
Fatahi, B, Le, TM & Khabbaz, H 2012, 'Effects of initial stress state on performance of embankments on soft soils', Australian Geomechanics Journal, vol. 47, no. 3, pp. 77-88.
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Analysing the behaviour of soft soil under embankment loads is a challenging task for geotechnical engineers. This numerical study revisits the case study of an embankment constructed on Boston Blue Clay, considering the model incorporating the influence of soil creep on the ground lateral deformation and pore water pressure. Then a numerical parametric study is conducted to investigate the influence of the lateral earth pressure coefficient at rest (K0) calculated based on the different available correlations on the vertical and horizontal displacements, pore water pressures, and the factor of safety of the embankment. The results indicate that although the value of Ko influences the predicted horizontal and vertical displacements notably, it has minor effects on the predicted pore water pressures. The lateral earth pressure coefficient influences the long term stability of the embankment and thus the effects of the initial stress field on the stability of embankments should be taken into consideration, while assessing the performance of embankments constructed on soft soils. It is recommended to determine the in situ horizontal stresses using accurate methods such as self-boring pressuremeter to predict the behaviour of embankments on the soft ground precisely.
Foroughi, J, Kimiaghalam, B, Ghorbani, SR, Safaei, F & Abolhasan, M 2012, 'Effect of conducting polypyrrole on the transport properties of carbon nanotube yarn', THIN SOLID FILMS, vol. 520, no. 24, pp. 7049-7053.
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Experiments were conducted to measure the electrical conductivity in three types of pristine and carbon nanotube-polypyrrole (CNT-PPy) composite yarns and its dependence on over a wide temperature range. The experimental results fit well with the analyti
Geng, X, Indraratna, B & Rujikiatkamjorn, C 2012, 'Analytical Solutions for a Single Vertical Drain with Vacuum and Time-Dependent Surcharge Preloading in Membrane and Membraneless Systems', International Journal of Geomechanics, vol. 12, no. 1, pp. 27-42.
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Ghandeharioon, A, Indraratna, B & Rujikiatkamjorn, C 2012, 'Laboratory and Finite-Element Investigation of Soil Disturbance Associated with the Installation of Mandrel-Driven Prefabricated Vertical Drains', Journal of Geotechnical and Geoenvironmental Engineering, vol. 138, no. 3, pp. 295-308.
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Hokmabadi, AS, Fakher, A & Fatahi, B 2012, 'Full scale lateral behaviour of monopiles in granular marine soils', MARINE STRUCTURES, vol. 29, no. 1, pp. 198-210.
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Monopiles are used in piers as mooring or berthing dolphins. This article reports the results of full-scale lateral loading tests on monopiles constructed as dolphins in the Pars Special Economic Energy Zone in southern Iran. The length and diameter of the monopiles were approximately 40 m and 2 m, respectively. Lateral loading tests of such large monopiles are not commonly undertaken, thus there is limited data available. This research developed a lateral analysis of piles computer code to examine analytical methods for pile analysis. Appropriate models were introduced resulting in accurate predictions in the analysis of lateral loaded piles. The results showed that traditional p-y curves and strain wedge models calculate larger pile head deflection in comparison to the field test data and therefore local calibration is essential. © 2012 Elsevier Ltd.
Hokmabadi, AS, Fatahi, B & Samali, B 2012, 'Recording inter-storey drifts of structures in time-history approach for seismic design of building frames', Australian Journal of Structural Engineering, vol. 13, no. 2, pp. 175-179.
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The growing trend in the application of direct displacement-based or performance-based design, lays more emphasis on the precise prediction of design parameters such as the inter-storey drift controlling the performance level of the structure. Practising engineers employ different methods to record the inter-storey drifts in time-history approach mainly based on the maximum lateral deformation of the structure. In this study, a 15-storey concrete moment resisting building is designed using time-history analysis. Then reliability and accuracy of each method in predicting the maximum inter-storey drifts under the influence of three earthquake records, namely 1995 Kobe, 1994 Northridge and 1940 El Centro earthquakes, are investigated. Results clearly indicate that to choose the most critical drift to evaluate the performance level of structures, the absolute maximum drift over time should be calculated. Other methods based on the maximum storey deflection may result in unconservative design.
Indraratna, B, Karimullah Hussaini, SK & Vinod, JS 2012, 'On The Shear Behavior of Ballast-Geosynthetic Interfaces', Geotechnical Testing Journal, vol. 35, no. 2, pp. 305-312.
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Abstract Large-scale direct shear tests were performed to explore the behavior of rail ballast-geogrid interfaces and establish the role of geogrid aperture size on the interface shear strength. Fresh latite ballast with an average particle size (D50) of 35 mm, and seven geogrids with equivalent aperture sizes ranging from 20.8 to 88 mm were used for this current study. The laboratory experimental results confirm that the interface shear strength is influenced by the geogrid aperture size. The interface efficiency factor (α), defined as the ratio of the shear strength of the interface to the internal shear strength of the ballast varies from 0.8 to 1.16, and the ballast-geosynthetic interface friction angles vary from 52 to 67°. Moreover, a criterion to determine the minimum and maximum aperture sizes required to generate the beneficial effects of the geogrid has been identified in this study.
Indraratna, B, Nguyen, VT & Rujikiatkamjorn, C 2012, 'Closure to “Assessing the Potential of Internal Erosion and Suffusion of Granular Soils” by Buddhima Indraratna, Vo Trong Nguyen, and Cholachat Rujikiatkamjorn', Journal of Geotechnical and Geoenvironmental Engineering, vol. 138, no. 6, pp. 775-775.
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Indraratna, B, Nguyen, VT & Rujikiatkamjorn, C 2012, 'Corrigendum: Hydraulic conductivity of saturated granular soils determined using a constriction-based technique', Canadian Geotechnical Journal, vol. 49, no. 10, pp. 1225-1225.
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Indraratna, B, Nguyen, VT & Rujikiatkamjorn, C 2012, 'Corrigendum: Hydraulic conductivity of saturated granular soils determined using a constriction-based technique', Canadian Geotechnical Journal, vol. 49, no. 6, pp. 754-754.
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Indraratna, B, Nguyen, VT & Rujikiatkamjorn, C 2012, 'Hydraulic conductivity of saturated granular soils determined using a constriction-based technique', Canadian Geotechnical Journal, vol. 49, no. 5, pp. 607-613.
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This study presents a new semi-empirical approach for predicting the saturated hydraulic conductivity of noncohesive (granular) soils through a constriction size–based technique. For the same particle-size distribution of a granular filter material, there can be many different void distributions depending on the as-compacted density. Therefore, particle-size distribution is not unique in determining the hydraulic conductivity as proposed in numerous earlier studies. In contrast, the constriction-size distribution is unique for a given as-placed density of the material, and therefore it is a better representation of hydraulic conductivity as proposed in this study. Accordingly, the hydraulic conductivity of a granular medium can be represented by an empirical power function that has been established on the basis of 60 laboratory tests.
Indraratna, B, Nguyen, VT & Rujikiatkamjorn, C 2012, 'Reply to the discussion by Wang and Dallo on “Hydraulic conductivity of saturated granular soils determined using a constriction-based technique” 1Appears in the Canadian Geotechnical Journal, 49(10): 1221–1222 [doi:10.1139/t2012-078].', Canadian Geotechnical Journal, vol. 49, no. 10, pp. 1223-1224.
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Indraratna, B, Nimbalkar, S & Rujikiatkamjorn, C 2012, 'Track Stabilisation with Geosynthetics and Geodrains, and Performance Verification through Field Monitoring and Numerical Modelling', International Journal of Railway Technology, vol. 1, no. 1, pp. 195-219.
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Indraratna, B, Rujikiatkamjorn, C, Balasubramaniam, AS & McIntosh, G 2012, 'Soft ground improvement via vertical drains and vacuum assisted preloading', Geotextiles and Geomembranes, vol. 30, pp. 16-23.
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Indraratna, B, Rujikiatkamjorn, C, Kelly, R & Buys, H 2012, 'Soft soil foundation improved by vacuum and surcharge loading', Proceedings of the Institution of Civil Engineers - Ground Improvement, vol. 165, no. 2, pp. 87-96.
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The Pacific Highway has been upgraded to support the high transportation demand between Sydney and Brisbane, along the north-east coast of Australia. To avoid the traffic through the busy town of Ballina, a bypass route was designed to traverse on a floodplain consisting of very soft, highly compressible, saturated marine clays up to 30 m deep in certain locations. A vacuum-assisted surcharge load scheme in conjunction with prefabricated vertical drains was selected to reduce the required time to consolidate the deep subsoil layers. The design of the combined vacuum and surcharge fill system and the construction of the embankment are described, and a comparison of the performance between the combined vacuum and surcharge loading system with the conventional surcharge only system is highlighted. Field data are presented and interpreted to demonstrate how the embankments performed during construction in both vacuum and non-vacuum areas. Suitable design charts for vertical drains are presented and discussed with a worked example, considering both vertical and radial drainage.
Indraratna, B, Thakur, PK, Vinod, JS & Salim, W 2012, 'Semiempirical Cyclic Densification Model for Ballast Incorporating Particle Breakage', International Journal of Geomechanics, vol. 12, no. 3, pp. 260-271.
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Ji, JC 2012, 'Application of a Weakly Nonlinear Absorber to Suppress the Resonant Vibrations of a Forced Nonlinear Oscillator', JOURNAL OF VIBRATION AND ACOUSTICS-TRANSACTIONS OF THE ASME, vol. 134, no. 4, pp. 1-6.
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A weakly nonlinear vibration absorber is used to suppress the primary resonance vibrations of a single degree-of-freedom weakly nonlinear oscillator with periodic excitation, where the two linearized natural frequencies of the integrated system are not under any internal resonance conditions. The values of the absorber parameters are significantly lower than those of the forced nonlinear oscillator, as such the nonlinear absorber can be regarded as a perturbation to the nonlinear primary oscillator. The characteristics of the nonlinear primary oscillator change only slightly in terms of its new linearized natural frequency and the frequency interval of primary resonances after the nonlinear absorber is added. The method of multiple scales is employed to obtain the averaged equations that determine the amplitudes and phases of the first-order approximate solutions. Selection criteria are developed for the absorber linear stiffness (linearized natural frequency) and nonlinear stiffness in order to achieve better performance in vibration suppression. Illustrative examples are given to show the effectiveness of the nonlinear absorber in suppressing nonlinear vibrations of the forced oscillator under primary resonance conditions. © 2012 American Society of Mechanical Engineers.
Ji, JC, Li, XY, Luo, Z & Zhang, N 2012, 'TWO-TO-ONE RESONANT HOPF BIFURCATIONS IN A QUADRATICALLY NONLINEAR OSCILLATOR INVOLVING TIME DELAY', INTERNATIONAL JOURNAL OF BIFURCATION AND CHAOS, vol. 22, no. 3.
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The trivial equilibrium of a weakly nonlinear oscillator having quadratic nonlinearities under a delayed feedback control can change its stability via a single Hopf bifurcation as the time delay increases. Double Hopf bifurcation occurs when the characteristic equation has two pairs of purely imaginary solutions. An interaction of resonant HopfHopf bifurcations may be possible when the two critical time delays corresponding to the two Hopf bifurcations have the same value. With the aid of normal form theory and centre manifold theorem as well as the method of multiple scales, the present paper studies the dynamics of a quadratically nonlinear oscillator involving time delay in the vicinity of the point of two-to-one resonances of HopfHopf bifurcations. The ratio of the frequencies of two Hopf bifurcations is numerically found to be nearly equal to two. The two resonant Hopf bifurcations can generate two respective periodic solutions. Consequently, the centre manifold corresponding to these two solutions is determined by a set of four first-order differential equations under two-to-one internal resonances. It is shown that the amplitudes of the two bifurcating periodic solutions admit the trivial solution and two-mode solutions for the averaged equations on the centre manifolds. Correspondingly, the cumulative behavior of the original nonlinear oscillator exhibits the initial equilibrium and a quasi-periodic motion having two frequencies. Illustrative examples are given to show the unstable zero solution, stable zero solution, and stable two-mode solution of the nonlinear oscillator under the two-to-one resonant HopfHopf interactions. © 2012 World Scientific Publishing Company.
Kardani, M, Nazem, M, Abbo, AJ, Sheng, D & Sloan, SW 2012, 'Refined h-adaptive finite element procedure for large deformation geotechnical problems', Computational Mechanics, vol. 49, no. 1, pp. 21-33.
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Kia, MB, Pirasteh, S, Pradhan, B, Mahmud, AR, Sulaiman, WNA & Moradi, A 2012, 'An artificial neural network model for flood simulation using GIS: Johor River Basin, Malaysia', Environmental Earth Sciences, vol. 67, no. 1, pp. 251-264.
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Kia, MB, Pirasteh, S, Pradhan, B, Mahmud, AR, Sulaiman, WNA & Moradi, A 2012, 'An artificial neural network model for flood simulation using GIS: Johor River Basin, Malaysia', Environmental Earth Sciences, vol. 67, no. 1, pp. 251-264.
Laird, J, Geers, DG, Wang, Y & Chou, CT 2012, 'Modeling Impact of Sensor Placement for Vision-Based Traffic Monitoring', Transportation Research Record: Journal of the Transportation Research Board, vol. 2315, no. 1, pp. 110-120.
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A generic sensor placement model for vision-based traffic monitoring is the focus of this study. A significant problem with such sensors is the difficulty in detection because of the occlusion between vehicles. Thus, the efficiency of traffic monitoring can be directly affected by sensor placement. To simulate various traffic flows, models are developed for various aspects of moving traffic. Such models include Gaussian mixture distributions for vehicle dimensions and the distribution for gap length between vehicles. These models are used to predict the vehicle detection error in a traffic flow as perceived from various sensor locations when vehicle headlight detection methods are used. Validation of the model has shown that accuracy is consistent with performance from a vehicle detection framework with approximately 3% variance on average.
Le, TM, Fatahi, B & Khabbaz, H 2012, 'Viscous Behaviour of Soft Clay and Inducing Factors', Geotechnical and Geological Engineering, vol. 30, no. 5, pp. 1069-1083.
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As a result of the scarcity of land for construction, a number of projects to construct man-made islands or to expand lands over soft grounds keeps increasing. Creep behaviour of soft ground has been considered as a challenging issue for engineers and researchers for many years. A number of studies have focused on the method to predict the creep deformation of the ground under a construction site. However, there is no unified theory to clearly explain the mechanism of soil creep deformation of soils. Results of the critical review in this paper indicate that the causes of soil creep can be categorised into five main groups, namely (a) the breakdown of the inter-particle bonds, (b) sliding between the soil particles, (c) water flow from micro-pores to macro-pores (d) the deformation due to the structural viscosity and (e) the deformation due to the jumping of bonds. This paper presents these mechanisms in details with an effort to recommend an enhanced explanation for the creep compression mechanisms of clays. © 2012 Springer Science+Business Media B.V.
Lee, J, Guan, H, Loo, Y-C & Blumenstein, M 2012, 'Refinement of Backward Prediction Method for Reliable Artificial Intelligence-Based Bridge Deterioration Modelling', Advances in Structural Engineering, vol. 15, no. 5, pp. 825-836.
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A deterioration model is the most critical component of a Bridge Management System (BMS). Artificial Intelligence (AI)-based bridge deterioration model has recently been developed to minimise uncertainties in predicting long-term performance of bridge structural elements. This model contains two components: (1) using Neural Network-based Backward Prediction Model (BPM) to generate unavailable historical condition ratings; and (2) using Time Delay Neural Network (TDNN) to perform long-term performance prediction of bridge structural elements. However new problems have emerged in the process of TDNN prediction. In this study, the BPM-generated condition ratings are used together with the actual overall condition ratings. The incompatibility between the two sets of data produces unreliable prediction outcomes during the TDNN process. This research therefore aims to introduce a new data processing procedure for BPM outcomes, by removing meaningless condition ratings that cause poor training outcomes for long-term prediction using TDNN. Consequently, the outcome of this study can improve accuracy of the current AI-based bridge deterioration model.
Li, C, Ma, T, Sun, L, Li, W & Zheng, A 2012, 'Application and verification of a fractal approach to landslide susceptibility mapping', Natural Hazards, vol. 61, no. 1, pp. 169-185.
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Li, J, Subhani, M & Samali, B 2012, 'Determination of Embedment Depth of Timber Poles and Piles Using Wavelet Transform', Advances in Structural Engineering, vol. 15, no. 5, pp. 759-770.
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This paper presents an investigation on the wave propagation in timber poles with Wavelet Transform (WT) analysis for identification of the condition and underground depth of embedded timber poles in service. Most of non-destructive testing (NDT) applications for timber poles using wave-based methods consider only single wave mode and no dispersion. However, for wave propagations in timber poles (damaged/undamaged), such simplification may not be correct, especially for broad band excitation using impulse impact. To investigate the problem, a 5m timber pole was investigated numerically and experimentally. A dispersion curve is generated from the numerical results to provide guidance on the velocity and wave mode selection. Continuous wavelet transform (CWT) is applied on the same signal to verify the presence of modes and to process data from experimental testing. The results are presented in both time domain and time-frequency domain for comparison. The results of the investigation showed that, wavelet transform analysis can be a reliable signal processing tool for NDT in terms of condition and embedment length determination.
Liu, MD, Indraratna, B, Horpibulsuk, S & Suebsuk, J 2012, 'Variations in strength of lime-treated soft clays', Proceedings of the Institution of Civil Engineers - Ground Improvement, vol. 165, no. 4, pp. 217-223.
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Strength is often the most significant parameter in measuring the effect of soil improvement in geotechnical engineering practice. In this paper, a primary study is made of the variation in unconfined compressive strength of lime-treated soft clays under various practical conditions. There are three major factors that affect the strength development: lime content, curing time, and curing temperature. The variations in strength with the three factors are analysed and quantified by proposed empirical equations. These equations are verified against experimental data independently. Based on an analysis of the above simulations, a general strength equation is proposed, unifying the influence of all the three factors into a single equation. The capacity of the general equation is demonstrated and it is seen that the proposed strength equations have the potential for predicting the strength of lime-treated clays under various conditions.
Luo, Z, Zhang, N, Ji, J & Wu, T 2012, 'A meshfree level-set method for topological shape optimization of compliant multiphysics actuators', COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING, vol. 223, pp. 133-152.
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This paper proposes a topology optimization method for compliant multiphysics actuators of geometrically nonlinear structures using meshfree Galerkin weak-forms and level set methods. The design boundary is implicitly represented as the zero level set of a higher-dimensional level set function, leading to a level set model capable of handling complex shape and topological changes with flexibilities. A family of compactly supported radial basis functions (CSRBFs) is firstly used to interpolate the level set function of Lipschitz continuity, and then augmented to construct the shape function for meshless approximation by satisfying basic requirements, in particular the predetermined consistency and the Kronecker delta function property. A meshless Galerkin method (MGM) with global weak-forms is established to implement the discretization of the state equations. The design of actuators is transformed into an easier size optimization from a more difficult shape and topology optimization. The design boundary evolution is just a question of advancing the discrete level set function in time by updating the design variables of the size optimization. Compared to most conventional level set methods, the proposed meshless level set method is able to implement the free moving boundary discontinuities without remeshing, and unify two different numerical procedures in propagating the discrete level set function (e.g. Eulerian grid) and approximating the state equation (e.g. Lagrangian mesh), respectively. This method can also avoid numerical difficulties in solving a series of complicate Hamilton-Jacobi partial differential equations (PDEs) with explicit time schemes. Two typical numerical examples are used to demonstrate the effectiveness of the proposed method. © 2012 Elsevier B.V.
Macabuag, J, Guragain, R & Bhattacharya, S 2012, 'Seismic retrofitting of non-engineered masonry in rural Nepal', Proceedings of the Institution of Civil Engineers - Structures and Buildings, vol. 165, no. 6, pp. 273-286.
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One of the greatest causes of casualties in major earthquakes around the world is the collapse of non-engineered masonry buildings (those built without engineering input). Yet by definition non-engineered structures remain largely outside of the scope of modern engineering research, meaning that the majority of those at risk often remain so. A further barrier to realising research in this field is the significant social and economic challenge of implementation in low-income communities, where non-engineered housing is prevalent. This paper introduces a retrofitting technique aimed at preventing or prolonging the collapse of adobe (mud brick) houses under strong earthquakes. This technique uses common polypropylene packaging straps to form a mesh, which is then used to encase structural walls. The aim of this paper is to give an overview of the retrofitting technique's development and implementation. The key development stages of static, dynamic and numerical testing are presented, showing that the proposed technique effectively prevents brittle masonry collapse and the loss of debris. An implementation project is then discussed, involving a training programme for rural masons in Nepal, a public shake-table demonstration and the retrofit of a real house. The implementation project proved effective at reaching rural communities but highlighted that government subsidies are required to incentivise the safeguarding of homes among low-income communities.
Masihpour, M, Abolhasan, M & Franklin, DR 2012, 'NFMIC Cooperative Communication Methods for Body Area Networks.', J. Networks, vol. 7, no. 9, pp. 1431-1440.
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To achieve higher data rate or to extend the coverage range of a wireless communication system, cooperative relay has been seen as a promising solution. This concept has been integrated in many traditional wireless communication networks. However, it has not been extensively examined for near field magnetic induction communication (NFMIC) systems. This paper aims to apply cooperative relay to NFMIC in a sense that is applicable to body area networking, since NFMIC is stated to be a suitable physical layer for body area networks. We have shown that using idle NFMIC nodes as relaying terminals, the system performance will be enhanced, as compared to a point to point communication system. In this context we have proposed three relaying methods to enhance the data rate and the received signal power in a personal area network. The relaying strategies are denoted as MI-Relay, MAMI Relay1 and MAMI Relay2. In this paper, using theoretical studies and simulation results, we have compared the performance of the three strategies and we have shown that higher data rates can be achieved through MAMI Relay1. However, we have discussed that the separation distance between relaying nodes and the source or destination can be a key factor for relay node selection.
Mohammady, M, Pourghasemi, HR & Pradhan, B 2012, 'Landslide susceptibility mapping at Golestan Province, Iran: A comparison between frequency ratio, Dempster–Shafer, and weights-of-evidence models', Journal of Asian Earth Sciences, vol. 61, pp. 221-236.
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Nazem, M, Kardani, M, Carter, JP & Sheng, D 2012, 'A comparative study of error assessment techniques for dynamic contact problems of geomechanics', Computers and Geotechnics, vol. 40, pp. 62-73.
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Pourghasemi, HR, Mohammady, M & Pradhan, B 2012, 'Landslide susceptibility mapping using index of entropy and conditional probability models in GIS: Safarood Basin, Iran', CATENA, vol. 97, pp. 71-84.
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Pourghasemi, HR, Pradhan, B & Gokceoglu, C 2012, 'Application of fuzzy logic and analytical hierarchy process (AHP) to landslide susceptibility mapping at Haraz watershed, Iran', Natural Hazards, vol. 63, no. 2, pp. 965-996.
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Pradhan, B, Chaudhari, A, Adinarayana, J & Buchroithner, MF 2012, 'Soil erosion assessment and its correlation with landslide events using remote sensing data and GIS: a case study at Penang Island, Malaysia', Environmental Monitoring and Assessment, vol. 184, no. 2, pp. 715-727.
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Rapeli, P, Fabritius, C, Kalska, H & Alho, H 2012, 'Do drug treatment variables predict cognitive performance in multidrug-treated opioid-dependent patients? A regression analysis study', Substance Abuse Treatment, Prevention, and Policy, vol. 7, no. 1, p. 45.
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Robinson, RG, Indraratna, B & Rujikiatkamjorn, C 2012, 'Final state of soils under vacuum preloading', Canadian Geotechnical Journal, vol. 49, no. 6, pp. 729-739.
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Vacuum preloading of clay deposits is becoming an increasingly popular ground improvement technique. Although many studies have been reported in literature, the mechanism of vacuum preloading is still not properly understood. Soil under vacuum preloading is expected to undergo an inward lateral deformation, therefore the influence of lateral deformation on volumetric strain requires further analysis. This paper addresses this aspect through laboratory studies on reconstituted samples of kaolinite. The Rowe cell apparatus was modified to measure lateral deformation under various states of stress because lateral and vertical deformation of soil depends on its state of stress and associated lateral pressure. A method for predicting the volumetric and lateral strains under vacuum consolidation is proposed and then applied to two case studies in China.
Rothberg, SJ, Halkon, BJ, Tirabassi, M & Pusey, C 2012, 'Radial vibration measurements directly from rotors using laser vibrometry: The effects of surface roughness, instrument misalignments and pseudo-vibration', Mechanical Systems and Signal Processing, vol. 33, pp. 109-131.
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Laser Doppler vibrometry (LDV) offers an attractive solution when radial vibration measurement directly from a rotor surface is required. Research to date has demonstrated application on polished-circular rotors and rotors coated with retro-reflective tape. In the latter case, however, a significant cross-sensitivity to the orthogonal radial vibration component occurs and post-processing is required to resolve individual radial vibration components. Until now, the fundamentally different behaviour observed between these cases has stood as an inconsistency in the published literature, symptomatic of the need to understand the effect of surface roughness. This paper offers the first consistent mathematical description of the polished-circular and rough rotor behaviours, combined with an experimental investigation of the relationship between surface roughness and cross-sensitivity. Rotors with surface roughness up to 10 nm satisfy the polished-circular rotor definition if vibration displacement is below 100% beam diameter, for a 90 μm beam, and below 40% beam diameter, for a 520 μm beam. On rotors with roughness between 10 nm and 50 nm, the polished-circular rotor definition is satisfied for vibration displacements up to 25% beam diameter, for a 90 μm beam, and up to 10% beam diameter, for a 520 μm beam. As roughness increases, cross-sensitivity increases but only rotors coated in retro-reflective tape satisfied the rough rotor definition fully. Consequently, when polished-circular surfaces are not available, rotor surfaces must be treated with retro-reflective tape and measurements post-processed to resolve individual vibration components. Through simulations, the value of the resolution and correction algorithms that form the post-processor has been demonstrated quantitatively. Simulations incorporating representative instrument misalignments and measurement noise have enabled quantification of likely error levels in radial vibration measurements. On a p...
RUZINOOR, CM, SHARIFF, ARM, PRADHAN, B, RODZI AHMAD, M & RAHIM, MSM 2012, 'A review on 3D terrain visualization of GIS data: techniques and software', Geo-spatial Information Science, vol. 15, no. 2, pp. 105-115.
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Samali, B, Dackermann, U & Li, J 2012, 'Location and Severity Identification of Notch-Type Damage in a Two-Storey Steel Framed Structure Utilising Frequency Response Functions and Artificial Neural Network', ADVANCES IN STRUCTURAL ENGINEERING, vol. 15, no. 5, pp. 743-757.
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This paper presents a vibration-based damage identification method that utilises damage fingerprints embedded in frequency response functions (FRFs) to identify location and severity of notch-type damage in a two-storey framed structure. The proposed method utilises artificial neural networks (ANNs) to map changes in FRFs to damage characteristics. To enhance damage fingerprints in FRF data, residual FRFs, which are differences in FRF data between the undamaged and the damaged structures, are used for ANN inputs. By adopting principal component analysis (PCA) techniques, the size of the residual FRF data is reduced in order to obtain suitable patterns for ANN inputs. A hierarchy of neural network ensembles is created to take advantage of individual characteristics of measurements from different locations. The method is applied to laboratory and numerical two-storey framed structures. A number of single notch-type damage scenarios of different locations and severities are investigated. To simulate field-testing conditions, numerically simulated data is polluted with white Gaussian noise of up to 10% noise-to-signal-ratio. The results from both numerical and experimental investigations show the proposed method is effective and robust for detecting notch-type damage in structures.
Sheng, DC & Yang, C 2012, 'Discussion of fundamental principles in unsaturated soil mechanics', Yantu Gongcheng Xuebao/Chinese Journal of Geotechnical Engineering, vol. 34, no. 3, pp. 438-456.
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An unsaturated soil is a state of the soils. All soils can be partially saturated with water. Therefore, constitutive models for soils should ideally represent the soil behaviours over entire ranges of possible pore pressure and stress values and allow arbitrary stress and hydraulic paths within these ranges. The last two decades or so have seen significant advances in modelling behaviours of unsaturated soils. A review of constitutive models for unsaturated soils is presented. In particular, it focuses on the fundamental principles that govern the volume change, shear strength, yield stress, water retention and hydro-mechanical coupling. Alternative forms of these principles are critically examined in terms of their predictive capacities for experimental data, the consistency between these principles and the continuity between saturated and unsaturated states.
Sołowski, WT, Hofmann, M, Hofstetter, G, Sheng, D & Sloan, SW 2012, 'A comparative study of stress integration methods for the Barcelona Basic Model', Computers and Geotechnics, vol. 44, pp. 22-33.
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Tabatabaiefar, SHR, Fatahi, B & Samali, B 2012, 'Finite difference modelling of soil-structure interaction for seismic design of moment resisting building frames', Australian Geomechanics Journal, vol. 47, no. 3, pp. 113-120.
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The importance of Soil-Structure Interaction (SSI) both for static and dynamic loads has been well established and the related literature spans at least 30 years of computational and analytical approaches for solving soil-structure interaction problems. Since the 1990s, great effort has been made to substitute the classical methods of design by new ones based on the concept of performance-based seismic design. Also, the necessity of estimating the vulnerability of existing structures and assessing reliable methods for their retrofit have greatly attracted the attention of engineering communities in most seismic zones throughout the world. In the present study, in order to draw a clear picture of soil characteristics effects on seismic response of moment resisting building frames, a ten storey moment resisting building frame, resting on shallow foundation, is selected in conjunction with three soil types with shear wave velocities less than 600m/s, representing soil classes Ce, De and Ee, according to Australian Standard AS 1170.4. The structure is modelled considering the three mentioned types of the soil deposits employing Finite Difference approach using FLAC 2D software. Fully nonlinear dynamic analyses under influence of different earthquake records are conducted, and the results of the different cases are compared and discussed. The results indicate that as shear wave velocity and shear modulus of the subsoil decrease, inter-storey drifts and subsequently the necessity of considering SSI effects in seismic design of moment resisting building frames increase. In general, by decreasing the subsoil stiffness, the effects of soil-structure interaction become more dominant and detrimental to the seismic behaviour of moment resisting building frames. These effects substantially alter performance level of the building model resting on soil classes De and Ee from life safe to near collapse. Consequently, structural safety for the mentioned building frames ...
Tennakoon, N, Indraratna, B, Rujikiatkamjorn, C, Nimbalkar, S & Neville, T 2012, 'The Role of Ballast-Fouling Characteristics on the Drainage Capacity of Rail Substructure', Geotechnical Testing Journal, vol. 35, no. 4, pp. 629-640.
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Abstract The ballast layer is designed to be free draining, but when the voids of the granular medium are wholly or partially filled because of the intrusion of fine particles, the ballast is considered to be “fouled.” To ensure acceptable track performance, it is necessary to maintain good drainage within the ballast layer. This paper critically examines the current methods commonly used for evaluating the degree of ballast fouling and, because of their limitations, a new parameter, “void contaminant index” is introduced. A series of large-scale constant head hydraulic conductivity tests were conducted with different levels of fouling to establish the relationship between the void contamination index and the associated hydraulic conductivity. Subsequently, a numerical analysis was executed to simulate more realistic two-dimensional flow under actual track geometry capturing the drainage capacity of ballast in relation to the void contamination index. In the context of observed test data, the drainage condition of the track could be classified into different categories together with a classification chart capturing the degree of fouling. The contents of this paper have already been considered in track maintenance schemes in the states of Queensland and New South Wales.
Tien Bui, D, Pradhan, B, Lofman, O & Revhaug, I 2012, 'Landslide Susceptibility Assessment in Vietnam Using Support Vector Machines, Decision Tree, and Naïve Bayes Models', Mathematical Problems in Engineering, vol. 2012, pp. 1-26.
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The objective of this study is to investigate and compare the results of three data mining approaches, the support vector machines (SVM), decision tree (DT), and Naïve Bayes (NB) models for spatial prediction of landslide hazards in the Hoa Binh province (Vietnam). First, a landslide inventory map showing the locations of 118 landslides was constructed from various sources. The landslide inventory was then randomly partitioned into 70% for training the models and 30% for the model validation. Second, ten landslide conditioning factors were selected (i.e., slope angle, slope aspect, relief amplitude, lithology, soil type, land use, distance to roads, distance to rivers, distance to faults, and rainfall). Using these factors, landslide susceptibility indexes were calculated using SVM, DT, and NB models. Finally, landslide locations that were not used in the training phase were used to validate and compare the landslide susceptibility maps. The validation results show that the models derived using SVM have the highest prediction capability. The model derived using DT has the lowest prediction capability. Compared to the logistic regression model, the prediction capability of the SVM models is slightly better. The prediction capability of the DT and NB models is lower.
Tien Bui, D, Pradhan, B, Lofman, O, Revhaug, I & Dick, OB 2012, 'Landslide susceptibility assessment in the Hoa Binh province of Vietnam: A comparison of the Levenberg–Marquardt and Bayesian regularized neural networks', Geomorphology, vol. 171-172, pp. 12-29.
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Tien Bui, D, Pradhan, B, Lofman, O, Revhaug, I & Dick, OB 2012, 'Landslide susceptibility mapping at Hoa Binh province (Vietnam) using an adaptive neuro-fuzzy inference system and GIS', Computers & Geosciences, vol. 45, pp. 199-211.
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Tien Bui, D, Pradhan, B, Lofman, O, Revhaug, I & Dick, OB 2012, 'Spatial prediction of landslide hazards in Hoa Binh province (Vietnam): A comparative assessment of the efficacy of evidential belief functions and fuzzy logic models', CATENA, vol. 96, pp. 28-40.
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Velani, N, Wilson, O, Halkon, BJ & Harland, AR 2012, 'Measuring the risk of sustaining injury in sport a novel approach to aid the re-design of personal protective equipment', Applied Ergonomics, vol. 43, no. 5, pp. 883-890.
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Despite the possibilities offered by new approaches in design and advances in materials and manufacturing methods, few items of Personal Protective Equipment (PPE) used in sport have seen significant change for many decades. A major reason for this is the tradition and conservative attitudes associated with many sports, although the absence of appropriate tools and techniques to assist the design and development process has also played a large part. The aim of this study was to develop the first stage of a method of identifying specific regions of the human anatomy that are at the greatest risk of sustaining injury during participation in sports in which the player is subjected to multiple ballistic impacts. It is proposed that the findings could be used to confirm future designs of sports PPE. Previous studies have identified the amount and the location of the protection provided by current commercially available products but, until now, no evidence has been reported to determine what protection is required based on an understanding of the likely impact and the anatomy of the athlete.Using the leg and cricket as examples of an anatomical feature and a sporting application respectively, the severity and probability of injury due to ball impacts typically observed in play are quantified, with respect to their location on the leg, to estimate the level of risk in that region. Results show that the level of risk is greatest in the shin regions of the front leg, suggesting that this region should be offered the greatest degree of protection, as is generally the case in commercially available leg guard designs. Conversely, however, the inner region of the mid shin of the back leg is at the lowest risk, suggesting that protection in this region might be substantially reduced, a feature which is certainly not included in current product; such a reduction may significantly enhance the ergonomic performance of the leg guard design.The findings of this preliminar...
WALKER, R, INDRARATNA, B & RUJIKIATKAMJORN, C 2012, 'Vertical drain consolidation with non-Darcian flow and void-ratio-dependent compressibility and permeability', Géotechnique, vol. 62, no. 11, pp. 985-997.
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Vertical drains increase the rate of consolidation in soft soils by facilitating faster dissipation of excess pore water pressure through short, horizontal drainage paths. This paper presents an analytical solution for non-linear radial consolidation under equal-strain conditions incorporating smear but ignoring well resistance. Three aspects of non-linearity are considered: (a) non-Darcian flow, (b) a log-linear void-ratio–stress relationship; and (b) a log-linear void-ratio–permeability relationship. The analytical solution to non-linear radial consolidation can explicitly capture the behaviour of both overconsolidated and normally consolidated soils. For non-linear material properties, consolidation may be faster or slower when compared with the cases with constant material properties. The difference depends on the compressibility/permeability ratios (Cc/Ck and Cr/Ck), the preconsolidation pressure and the stress increase. If Cc/Ck < 1 or Cr/Ck < 1 then the coefficient of consolidation increases as excess pore pressures dissipate, and the corresponding rate of consolidation is greater.
Wang, SY, Sloan, SW, Sheng, DC & Tang, CA 2012, 'Numerical analysis of the failure process around a circular opening in rock', Computers and Geotechnics, vol. 39, pp. 8-16.
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Yang, C, Sheng, D & Carter, JP 2012, 'Effect of hydraulic hysteresis on seepage analysis for unsaturated soils', Computers and Geotechnics, vol. 41, pp. 36-56.
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Youssef, AM, Pradhan, B, Sabtan, AA & El-Harbi, HM 2012, 'Coupling of remote sensing data aided with field investigations for geological hazards assessment in Jazan area, Kingdom of Saudi Arabia', Environmental Earth Sciences, vol. 65, no. 1, pp. 119-130.
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ZHOU, A-N, SHENG, D & CARTER, JP 2012, 'Modelling the effect of initial density on soil-water characteristic curves', Géotechnique, vol. 62, no. 8, pp. 669-680.
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This paper presents a simple approach to quantify the effect of initial soil density on the soil-water characteristic curve (SWCC) of unsaturated soils. This approach is based on an incremental relationship between the degree of saturation and the initial void ratio, which satisfies the intrinsic constraints for three-phase porous materials. The incremental relationship can be incorporated into existing SWCC equations to model the water retention behaviour for deformable soils. Only one additional parameter is introduced, which can be conveniently calibrated by way of conventional water retention tests. The SWCCs for the same soil at different initial void ratios can be found using the proposed approach. The proposed approach is validated against experimental data from drying tests for both compacted and reconstituted soils.
Zhou, A-N, Sheng, D, Sloan, SW & Gens, A 2012, 'Erratum to “Interpretation of unsaturated soil behaviour in the stress–saturation space II: Constitutive relationships and validations’’', Computers and Geotechnics, vol. 43, pp. 177-177.
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Zhou, A-N, Sheng, D, Sloan, SW & Gens, A 2012, 'Interpretation of unsaturated soil behaviour in the stress – Saturation space, I: Volume change and water retention behaviour', Computers and Geotechnics, vol. 43, pp. 178-187.
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Zhou, A-N, Sheng, D, Sloan, SW & Gens, A 2012, 'Interpretation of unsaturated soil behaviour in the stress–saturation space', Computers and Geotechnics, vol. 43, pp. 111-123.
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Zoorabadi, M, Indraratna, B & Nemcik, J 2012, 'A new equation for the equivalent hydraulic conductivity of rock mass around a tunnel', International Journal of Rock Mechanics and Mining Sciences, vol. 54, pp. 125-128.
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A, H, B, I & C, R 1970, 'Use of the Soil Modulus for Compaction Control of Compacted Soils', Proceedings of the International Conference on Ground Improvement & Ground Control, International Conference on Ground Improvement & Ground Control, Research Publishing Services.
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Abbas, AA, Mansor, SB, Pradhan, B & Tan, CK 1970, 'Spatial and seasonal variability of Chlorophyll-a and associated oceanographic events in Sabah water', 2012 Second International Workshop on Earth Observation and Remote Sensing Applications, 2012 Second International Workshop on Earth Observation and Remote Sensing Applications (EORSA), IEEE, pp. 215-219.
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AL Sabbagh, A, Braun, R & Abolhasan, M 1970, 'A power efficient RAT selection algorithm for heterogeneous wireless networks', 2012 International Symposium on Communications and Information Technologies (ISCIT), 2012 International Symposium on Communications and Information Technologies (ISCIT), IEEE, Gold Coast, Australia, pp. 997-1002.
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The Fourth Generation of wireless network (4G) is a heterogeneous network where different Radio Access Technologies (RATs) are integrated. This requires a need for Common Radio Resource Management (CRRM) to support efficient utilization of radio resources and to provide the required Quality of Service (QoS) for allocated calls. RAT selection algorithms are an important part of CRRM. This paper proposes an intelligent hybrid power efficient RAT selection algorithm (patent pending1). It is a battery power saver algorithm which includes sorting available RATs, collecting information on each RAT using the IEEE P1900.4 Protocol, and making decisions for selecting the most suitable RAT for incoming calls. The proposed power efficient algorithm is compared to centralized and distributed algorithms in terms of new call blocking and Vertical Handover (VHO) call dropping probabilities. Users' satisfactions probability and saving battery power percentage are also compared. Simulation results show that the proposed algorithm performs better than the centralized and distributed algorithms in terms of blocking, dropping and users' satisfactions probabilities. The proposed and the distributed algorithms have similar performance in term of saving battery power, and both perform better than the centralized algorithm. © 2012 IEEE.
Al Sabbagh, A, Braun, RM & Abolhasan, M 1970, 'Interaction of Radio Resource Management in Heterogeneous wireless Networks', 1st Australian Conference on the Applications of Systems Engineering (ACASE'12), 1st Australian Conference on the Applications of Systems Engineering (ACASE'12), University of Technology, Sydney, Sydney, Australia, pp. 34-35.
AlAamri, H, Safaei, F, Abolhasan, M & Franklin, DR 1970, 'Location-Based Utilization for Unidirectional Links in MANETs', Proceedings of the Eighth International Conference on Wireless and Mobile Communications, International Conference on Wireless and Mobile Communications, XPS (Xpert Publishing Services) / IARIA, Venice, Italy, pp. 248-253.
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AbstractHeterogeneous Mobile Ad hoc Network(HMANET) comprises different nodes with different capabilities. Hence, transmission and receiving capabilities aredifferent. This causes unidirectionality problem. Avoidances is the most used strategy in researches to route data, e.g., Blacklist. In this paper, we proposed a strategy for on-demand routing protocols to detect unidirectional link and resolve it in timely fashion. This strategy is based on utilizing locations of nodes to filter and cache incoming RREQ packets to find reliable path to destination in the existence of unidirectional links. Simulation results show that our strategy outperforms Blacklist strategy in homogeneous and heterogeneous MANET.
Alamdari, M, Li, J & Samali, B 1970, 'A comparative study on the performance of the damage detection methods in the frequency domain', From materials to structures: Advancement through innovation, Australasian Conference on the Mechanics of Structures and Materials, CRC Press, Sydney, Australia, pp. 867-872.
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During last two decades, a vast number of damage detection methods have been proposed either in frequency or time domain. These methods normally have their own advantages and limitations or suitable applications; the purpose of this study is to examine the performance of the some popular methods on localisation a possible damage on a sample structure. All of the chosen methods are based on the frequency domain data and work based on proposing a damage sensitive indicator which contains spatial information. Mode shape curvature, frequency response functionsâ curvature, modal strain energy, flexibility matrix and spatial wavelet transform were amongst those damage detection methods were chosen for this study. The case study considers a clamped-clamped beam which was modelled by solid elements in order to define several damage stages based on different crack depth. Damage was simulated by reduction in elastic modulus of the elements in damage zone. The transient response of the structure due to an external impact excitation was obtained by ANSYS and then polluted by different percentages of white noise. The time-domain responses at selected evenly-spaced locationswas then processed byMATLAB to achieve the FRFs and mode shapes respectively by applying Fourier transform and eigenvalue realization algorithm (ERA). Based on the obtained results, it was found that despite some of these methods were suggested by so many researchers, they completely fail in localising damage in the structure even at high level of damage severity.
Alamdari, M, Li, J & Samali, B 1970, 'A FRF-based damage detection method utilising wavelet decomposition', From materials to structures: Advancement through innovation, Australasian Conference on the Mechanics of Structures and Materials, CRC Press, Sydney, Australia, pp. 873-877.
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Damage in a structure causes deviation in dynamic responses of the structure either in frequency or time domain in comparison with its healthy status. The purpose of this study is to present a new damage detection method in order to detect and localize the structural damage. This novel algorithm is based on the directly-measured frequency response functions (FRFs). The approach is composed of three major steps: first, developing the curvature of FRFs which produces spatially distributed shape functions at each frequency coordinate, secondly, normalization of FRFsâ curvature in order to enhance the influence of the lower-frequency-band data; finally decomposition of the obtained profiles (normalized version of FRFsâ curvature) by conducting wavelet analysis to detect any possible structural abnormality through structure. The combination of these three steps leads to a robust algorithm in detection and localisation of any damage in the structure even at small levels which other FRF-based methods were unable to detect. There are some benefits with the presented method: first, this method does not need higher-frequency-range data which is hard to obtain in most civil applications; second, there is no need for baseline data from the intact structure; This is particularly attractive for practical applications as it opens an opportunity for online monitoring of the structural integrity without demanding for any previous data records of the structure. The performance of the method is evaluated on a numerical model and the effect of different parameters such as the location of the excitation point, the level and the location of the damage was studied; the results demonstrated that the method can efficiently identify the location of the damage in the structure even for damage at small levels.
Althuwaynee, OF, Pradhan, B, Mahmud, AR & Yusoff, ZM 1970, 'Prediction of slope failures using bivariate statistical based index of entropy model', 2012 IEEE Colloquium on Humanities, Science and Engineering (CHUSER), 2012 IEEE Colloquium on Humanities, Science and Engineering (CHUSER), IEEE, pp. 362-367.
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Anantanasakul, P, Indraratna, B, Nimbalkar, SS & Neville, T 1970, 'Effects of Geosynthetic Reinforcement on Performance of Ballasted Rail Track', Proceedings of the International Conference on Ground Improvement & Ground Control, International Conference on Ground Improvement & Ground Control, Research Publishing Services.
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Askari, M, Li, J & Samali, B 1970, 'Application of extended, unscented, iterated extended and iterated unscented Kalman Filter for real-time structural identification', Advances in Applied Mechanics Research, Conference Proceedings - 7th Australasian Congress on Applied Mechanics, ACAM 2012, Australasian Congress on Applied Mechanics, Engineers Australia, Adelaide, pp. 1041-1051.
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System identification refers to any systematic way of deriving or improving models of dynamical systems through the use of experimental and field testing input-output data. In the field of civil engineering, identification of the state of a structure during service condition under dynamic loading, such as earthquake, in order to detect any damage as it occurs, has posed a great challenge to the research community. Therefore, online and real-time structural identification has attracted a great deal of attentions in the structural engineering research over the past decades, especially when input-output measurement data are contaminated by high-level noise. Among real-time identification methods, one of the most successful and widely used methods for estimation of states and parameters is the Kalman filter and its various nonlinear extensions like Extended Kalman Filter (EKF) and iterated Extended Kalman Filter (IEKF). However, these methods are not effective in the case of highly nonlinear problems. To overcome the problem, two filtering techniques, namely unscented Kalman filter (UKF) and iterated unscented Kalman filter (IUKF), have been recently developed to handle any functional nonlinearity. In this paper, an investigation has been carried out on the aforementioned methods for their effectiveness and efficiencies through a highly nonlinear SDOF structure as well as a two-storey linear structure. Results show that, although IEKF is an improved version of EKF, the IUKF, in most of cases, produces better results on state estimation and parameter identification than UKF and IEKF. IUKF is also more robust to measurement noise levels compared to the other approaches.
Banasiak, L & Indraratna, B 1970, 'Performance Monitoring of a Permeable Reactive Barrier (PRB) for the Remediation of Acidic Groundwater in Acid Sulfate Soil (ASS) Terrain', Proceedings of the International Conference on Ground Improvement & Ground Control, International Conference on Ground Improvement & Ground Control, Research Publishing Services.
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Banasiak, L & Indraratna, B 1970, 'Permeable Reactive Barrier (PRB) Technology: An Innovative Solution for the Remediation of Acidic Groundwater from Acid Sulphate Soil (ASS) Terrain', GeoCongress 2012, GeoCongress 2012, American Society of Civil Engineers, pp. 3523-3532.
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The remediation of acidic groundwater contaminated with potentially toxic metals such as aluminium (Al) and iron (Fe) resulting from the oxidation of sulphidic materials in acid sulphate soils (ASSs) is a challenging geo-environmental problem that requires innovative engineering solutions. In low-lying coastal floodplains, the remediation strategies of groundwater manipulation (e.g. fixed-level weirs) and tidal buffering (e.g. two-way modified floodgates) are not feasible due to the risk of flooding during heavy rainfall events and their inability to prevent pyritic oxidation. In view of this in 2006, the first pilot subsurface permeable reactive barrier (PRB) using recycled concrete for the remediation of acidic groundwater (- pH 3) was employed in ASS terrain in southeast New South Wales, Australia. While monitoring has confirmed the PRB has successfully neutralized the acidic groundwater to - pH 7.3 and removed - 95% of Al and Fe, this technology is not without its challenges. These have included the: (1) selection of the appropriate reactive material; (2) elucidation of the mechanisms involved in the neutralization of the acidic groundwater; (3) chemical armouring and possible clogging of the recycled concrete by Al and Fe oxy/hydroxide precipitates; and (4) thus, uncertainty regarding the longevity of the PRB. This paper will present details on the screening process of reactive materials, the installation of the PRB, the column experiments simulating the flow of acidic groundwater through the PRB for the determination of the predominant neutralization reactions occurring within the PRB, the long-term performance of the PRB and the current research strategy for determining its longevity. © 2012 American Society of Civil Engineers.
Banasiak, L, Pathirage, P & Indraratna, B 1970, 'Modeling of Chemical Armoring in a Permeable Reactive Barrier (PRB) in Acid Sulfate Soil (ASS) Terrain', Proceedings of the International Conference on Ground Improvement & Ground Control, International Conference on Ground Improvement & Ground Control, Research Publishing Services.
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Bang Zhang, Yang Wang & Wei Wang 1970, 'Batch mode active learning for multi-label image classification with informative label correlation mining', 2012 IEEE Workshop on the Applications of Computer Vision (WACV), 2012 IEEE Workshop on Applications of Computer Vision (WACV), IEEE, pp. 401-407.
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The performances of supervised learning techniques on image classification problems heavily rely on the quality of their training images. But the acquisition of high quality training images requires significant efforts from human annotators. In this paper, we propose a novel multi-label batch model active learning (MLBAL) approach that allows the learning algorithm to actively select a batch of informative example-label pairs from which it learns at each learning iteration, so as to learn accurate classifiers with less annotation efforts. Unlike existing methods, the proposed approach fines the active selection granularity from example to example-label pair, and takes into account the informative label correlations for active learning. And the empirical studies demonstrate its effectiveness. © 2012 IEEE.
Bang Zhang, Yang Wang & Wei Wang 1970, 'Multiple-Instance learning from multiple perspectives: Combining models for Multiple-Instance learning', 2012 IEEE Workshop on the Applications of Computer Vision (WACV), 2012 IEEE Workshop on Applications of Computer Vision (WACV), IEEE, pp. 481-487.
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Multiple-Instance learning (MIL), which relaxes training annotation granularity from instance level to instance collection (bag) level by applying bag concept, obtains increasing attentions from computer vision community. Due to its flexible annotation mechanism, MIL has been naturally utilized on a variety of computer vision problems. And numerous models have been proposed, each of which is ingeniously designed to catch certain characteristics of MIL. However different models only perform well on certain tasks, and further improvement can hardly be achieved. © 2012 IEEE.
Blumenstein, M, Pal, U & Uchida, S 1970, 'Message from General Chair and Program Chairs', 2012 10th IAPR International Workshop on Document Analysis Systems, 2012 10th IAPR International Workshop on Document Analysis Systems (DAS), IEEE.
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Bu, G, Lee, J, Guan, H, Blumenstein, M & Loo, Y-C 1970, 'Performance Prediction of Concrete Elements in Bridge Substructures using Integrated Deterioration Method', IABSE Congress Reports, IABSE Congress, Seoul 2012: Innovative Infrastructures – Towards Human Urbanism, International Association for Bridge and Structural Engineering (IABSE).
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<p>The typical probabilistic deterioration model cannot guarantee a reliable long-term prediction for various situations of available condition data. To minimise this limitation, this paper presents an advanced integrated method using state-/time-based model to build a reliable transition probability for prediction long-term performance of bridge elements. A selection process is developed in this method to automatically select a suitable prediction approach for a given situations of condition data. Furthermore, a Backward Prediction Model (BPM) is employed to effectively prediction the bridge performance when the inspection data are insufficient. In this study, a benchmark example- concrete element in bridge substructures is selected to demonstrate that the BPM in conjunction with time-based model can improve the reliability of long-term prediction.</p>
Buchroithner, MF, Petters, C & Pradhan, B 1970, 'Three-dimensional visualisation of the world-class prehistoric site of the Nial Great Cave, Borneo, Malaysia', Conference Handout. Interdisciplinary Conference on Digital Cultural Heritage, July, pp. 2-4.
Bui, DT, Pradhan, B, Lofman, O, Revhaug, I & Dick, OB 1970, 'Landslide Susceptibility Assessment at Hoa Binh Province of Vietnam Using Frequency Ratio Model', 2012 Asia Pacific Conference on Environmental Science and Technology. Advances in Biomedical Engineering, p. 476.
Chiaro, G, Indraratna, B, Rujikiatkamjorn, C & Naeeni, S 1970, 'Effects of Steel Slag Content and Curing Time on Compressive Strength of Underwater Compacted Coal Wash', Proceedings of the International Conference on Ground Improvement & Ground Control, International Conference on Ground Improvement & Ground Control, Research Publishing Services.
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Chitsaz, M, Wang, K, Blumenstein, M & Qi, G 1970, 'Concept Learning for $\ensuremath{\ensuremath{\cal E}\ensuremath{\cal L}^{++}}$ by Refinement and Reinforcement', Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics), Pacific Rim International Conference on Artificial Intelligence, Springer Berlin Heidelberg, Kuching, Malaysia, pp. 15-26.
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Ontology construction in OWL is an important and yet time-consuming task even for knowledge engineers and thus a (semi-) automatic approach will greatly assist in constructing ontologies. In this paper, we propose a novel approach to learning concept definitions in from a collection of assertions. Our approach is based on both refinement operator in inductive logic programming and reinforcement learning algorithm. The use of reinforcement learning significantly reduces the search space of candidate concepts. Besides, we present an experimental evaluation of constructing a family ontology. The results show that our approach is competitive with an existing learning system for ℰℒ. © 2012 Springer-Verlag.
Chu, J, Indraratna, B, Yan, S & Rujikiatkamjorn, C 1970, 'Soft Soil Improvement Through Consolidation: An Overview', Proceedings of the International Conference on Ground Improvement & Ground Control, International Conference on Ground Improvement & Ground Control, Research Publishing Services.
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Fatahi, B, Engelbert, D, Mujic, S & Khabbaz, H 1970, 'Assessment of Surcharging on Strength and Stiffness of Cement Treated Clays', Grouting and Deep Mixing 2012, Proceedings of the Fourth International Conference on Grouting and Deep Mixing, American Society of Civil Engineers, Louisiana, USA, pp. 272-280.
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Deep soil mixing (DSM) is a ground improvement technique most appropriate in applications aimed at improving properties of soft clay, which is very sensitive to temperature and water content changes. This paper presents an experimental study capturing effects of surcharge application during curing time on the stress-strain behaviour of DSM columns. An investigation has been undertaken into the effects of varying surcharges, applied immediately after mixing, ranging from 40kPa to 120kPa, on the strength and stiffness of cement treated kaolinite clay samples with different cement contents. The results of uniaxial tests are analysed to illustrate how the Young's modulus and unconfined compressive strength (UCS) are influenced under varying surcharges. Results confirm a promising increase in strength and stiffness with increased preloading. Results are significant, in that desired DSM column strengths can be achieved through a combination of cement and surcharging, as opposed to increasing the cement content; thus significantly reducing the carbon footprint induced by cement production. © 2012 American Society of Civil Engineers.
Fatahi, B, Far, H, Sadeghi Hokmabadi, A & Samali, B 1970, 'Significance of bedrock depth in dynamic soil-structure interaction analysis for moment resisting frames', 2nd International Conference on Performance-Based Design in Earthquake Geotechnical Engineering, International Conference on Performance-Based Design in Earthquake Geotechnical Engineering, Associazione Geotecnica Italiana - Roma, Taormina, Italy, pp. 1396-1406.
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In this study, a fifteen storey moment resisting building frame, resting on a shallow foundation, is selected in conjunction with two clayey soils with the shear wave velocities less than 600m/s, representing soil classes De and Ee, according to AS 1170.4. Different bedrock depths including 10m, 20m, and 30 m are employed in the numerical modelling using finite difference software FLAC 2D. Fully nonlinear dynamic analysis under the influence of different earthquake records is conducted, and the results of the three different cases are compared and discussed. The results indicate that the dynamic properties of the subsoil such as shear wave velocity as well as bedrock depth play significant roles in seismic response of the building frames under the influence of soil-structure interaction. As the bedrock depth increases, lateral deflections and inter-storey drifts of the structures increase. These effects can change the performance level of structures from life safe to near collapse or total collapse. Therefore, the conventional design procedure excluding SSI is not adequate enough to guarantee the structural safety for the building frames resting on soft soil deposits.
Fatahi, B, Khabbaz, H & Fatahi, B 1970, 'Application of Polypropylene and Carpet Fibres to Improve Mechanical Properties of Cement Treated Clay', International Symposium on Ground Improvement IS-GI, PROCEEDINGS OF THE INTERNATIONAL SYMPOSIUM, SIMSG, Brussel, pp. 303-308.
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In this study, the influence of two types of fibre reinforcement, namely polypropylene and carpet waste fibres, on mechanical properties of cement treated kaolinite is investigated. The results of unconfined compressive strength testing of 63 cylindrical samples of cement treated kaolinite with varied cement and fibre contents are analysed to discern the relationships between these parameters and the key mechanical properties, including unconfined compressive strength and stiffness of treated soil. The fibre reinforcement increases the peak strength. The initial Young's modulus of the fibre reinforced cement treated kaolinite increases by adding polypropylene whereas slightly decreases when adding carpet fibres. The improvement of mechanical properties was far more pronounced with the introduction of polypropylene than carpet waste fibres. The implication of these findings is a cost effective and environmentally friendly alternative compare to increasing cement content in soil to achieve the required mechanical properties, particularly where the strength is a governing consideration.
Fatahi, B, Khabbaz, H & Le, TM 1970, 'Improvement of rail track subgrade using stone columns combined with geosynthetics', ADVANCES IN TRANSPORTATION GEOTECHNICS II, International Conference on Transportation Geotechnics (ICTG), CRC Press - Taylor & Francis Group, Hokkaido, Japan, pp. 202-206.
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This study seeks to identify the effectiveness of ground improvement using stone columns in controlling settlement of soft soils when placed under the dead loads of the rail structure and the large live loads of freight trains. The employed numerical study assesses the relationship between the column position in the track cross section and the overall settlement of the ballasted rail formation. The numerical results show that the overall settlement of the track reduces significantly with the use of stone columns close to the centre of the track and not just under the rail. In addition, application of one layer of geogrids between sub-ballast and sub-grade assists to reduce the maximum settlement of track decreasing the future maintenance costs. © 2012 Taylor & Francis Group.
Ghobadi, Y, Pradhan, B, Kabiri, K, Pirasteh, S, Shafri, HZM & Sayyad, GA 1970, 'Use of multi-temporal remote sensing data and GIS for wetland change monitoring and degradation', 2012 IEEE Colloquium on Humanities, Science and Engineering (CHUSER), 2012 IEEE Colloquium on Humanities, Science and Engineering (CHUSER), IEEE, pp. 103-108.
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Halkon, B, Webster, J, Mitchell, S & Mientjes, M 1970, 'Development of a test methodology for the assessment of human impacts in sport', Procedia Engineering, 9th Conference of the International-Sports-Engineering-Association (ISEA), Elsevier BV, Univ Massachusetts Lowell, Lowell, MA, pp. 813-818.
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The study described in this paper aims to develop a suitable method for the measurement of contact forces, pressures and velocities of simulated human-on-human impacts typical of those experienced within American Football. A thin-film pressure sensor system was chosen to enable the impacts to be quantified, however, initial testing suggested that the measured impact forces were underestimated by circa 30% with the system calibrated in the standard, static pressure manner. A two-stage, dynamic calibration was therefore developed, in which the sensors were subsequently dynamically loaded in a manner more representative of the impacts, allowing an appropriate dynamic calibration factor to be derived. To determine the typical impact force levels experienced in a shoulder-on-thigh impact event, eight subjects were required to perform three 'good' tackles at two different velocities. The processed results identified a peak, transmitted force of 1.1 (0.4) and 1.7 (0.5) kN for 'low' and 'medium' velocities respectively, with corresponding effective areas of application of 70 (22) cm2 and 85 (25) cm2 and contact times of 0.257 (0.098) s and 0.245 (0.112) s respectively. © 2012 Published by Elsevier Ltd.
Heitor, A, Indraratna, B & Rujikiatkamjorn, C 1970, 'Characterising compacted soil using shear wave velocity and matric suction', Australian Geomechanics Journal, pp. 79-86.
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The manner in which soil compacts governs the practical and reliable criteria in controlling compaction in the field. A nuclear density meter, based on radioactive isotopes, is the method most commonly used for field compaction, and while it performs well for controlling placement, its localised nature is not suitable for deeper fills or for assessing larger surface areas. In those types of conditions, alternative non-destructive methods should be considered. Numerous research studies have focused on the characteristics of compacted soil at its optimum moisture content under saturated conditions, but only a few have evaluated compacted soil under unsaturated conditions using surface wave and shear wave velocity surveys. This study explores the performance of a cost effective method for evaluating the characteristics of compacted fills by measuring the shear wave velocity and matric suction to evaluate the void ratio or dry density of compacted soil. Laboratory studies of compacted specimens were used to evaluate this method and their performance under different isotropic confining pressures. The results showed that the shear wave velocity and matric suction can effectively predict how the soil will compact, but its success requires field measurements of both shear wave velocity and matric suction. The application of this relationship would enable practitioners to efficiently control compaction over large areas during post-construction stages, and locate areas within the existing formations where the soil was not sufficiently compacted.
Hussaini Syed, KK, Indraratna, B & J. S, V 1970, 'Some Aspects of the Shear Behaviour of Unreinforced and Geosynthetic-Reinforced Rail Ballast', Proceedings of the International Conference on Ground Improvement & Ground Control, International Conference on Ground Improvement & Ground Control, Research Publishing Services.
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Indraratna, B 1970, 'Ground Improvement for Transportation Infrastructure in Australia', Proceedings of the International Conference on Ground Improvement & Ground Control, International Conference on Ground Improvement & Ground Control, Research Publishing Services.
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Indraratna, B, Geng, XY & Rujikiatkamjorn, C 1970, 'Consolidation of Ground with Prefabricated Vertical Drains Combined with Time-Dependent Surcharge Loading in Membrane System', GeoCongress 2012, GeoCongress 2012, American Society of Civil Engineers, pp. 60-69.
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The system of vertical drains combined with vacuum pressure and/or surcharge preloading is widely used to accelerate the consolidation of soft clay, in order to decrease the long-term settlements and curtail lateral displacement. This study presents a solution of soil consolidation subjected to vacuum preloading for a membrane system, which is comprised of an airtight membrane laid over the drainage layer, under time-dependent surcharge preloading. Both vertical and horizontal drainage were considered in this analysis to reflect realistic in-situ conditions. The model was verified using the measured settlement and excess pore water pressure obtained from various sites at Ballina Bypass, Australia. In the paper, the solutions improve the accuracy of predicting the dissipation of pore water pressure and the associated settlement. The effect of the permeability of the sand blanket in the membrane system and the possible loss of vacuum are also discussed. Finally, design charts have been developed, for the convenience of practicing engineers. © 2012 American Society of Civil Engineers.
Indraratna, B, Heitor, A & Rujikiatkamjorn, C 1970, 'Effect of compaction energy on shear wave velocity of dynamically compacted silty sand soil', 5th Asia-Pacific Conference on Unsaturated Soils 2012, pp. 538-543.
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This study was focused on the effects of compaction energy on the dynamic properties of a silty sand in its as-compacted state in relation to the measured values of marric suction. The influence of the imparted energy on the shear wave velocity and the small-strain shear modulus of the compacted soil was studied for three different energy levels that correspond to the standard Proctor as well as reduced and enhanced. The specimens were prepared with moisture contents ranging from the dry to wet of optimum, and subsequently compacted to known dry unit weights for which the corresponding marric suction and shear wave velocity were measured. While a non-destructive technique adopting Bender elements was used to determine the shear wave velocity, the marric suction was evaluated using the filter paper method. Test results reveal that the shear wave velocity increases with the level of imparted compaction energy and the associated marric suction developed in the compacted soil. However, the change in shear wave velocity along the compaction curve is very significant. Pronounced compaction energy dependence is observed on the dry side of the optimum moisture content, whereas on the wet side of the optimum the marric suction governs the variation in the shear wave velocity.
Indraratna, B, Mahamud, MAA & Vinod, JS 1970, 'Chemical and Mineralogical Behaviour of Lignosulfonate Treated Soils', GeoCongress 2012, GeoCongress 2012, American Society of Civil Engineers, pp. 1146-1155.
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This paper presents the results of Unconfined Compressive Strength tests (UCS) carried out on clay soils stabilized with Lignosulfonate (LS). Laboratory studies indicate that lignosulfonate can increase the stiffness of the treated soils. Moreover, the influence of clay minerals on the LS stablisation is investigated using Fourier Transform Infrared (FTIR) Spectroscopy and Electrical Conductivity (EC). The analysis confirms that the clay mineralogy plays an important role in the stabilisation of clay soils. The stabilization mechanism is mainly due to the formation of lignosulfonate-clay amorphous compounds through the electrostatic reaction process. © 2012 American Society of Civil Engineers.
Indraratna, B, Premadasa, WN & Oliveira, D 1970, 'Physical Modeling of Soil-Infilled Discontinuities', GeoCongress 2012, GeoCongress 2012, American Society of Civil Engineers, pp. 2312-2321.
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Soil-infilled discontinuities adversely affect the overall strength of rock mass because, the soft infill material, especially when saturated, drastically reduces the shear strength of the rock joint. Due to all the uncertainties arising from sample heterogeneity and scale effects, physical modeling of rock joints becomes an essential approach for understanding all the different factors affecting the geomechanical behaviour in the field. In this paper, several modeling techniques adopted at the University of Wollongong are discussed. These techniques focused on isolating the different factors affecting the behaviour of soil-infilled discontinuities. Some of the resulting semi-empirical models that were developed to describe the effect of the soft-infill on the joint shear strength are also presented. © 2012 American Society of Civil Engineers.
Indraratna, B, Rujikiatkamjorn, C & Chiaro, G 1970, 'Characterization of Compacted Coal Wash As Structural Fill Material', GeoCongress 2012, GeoCongress 2012, American Society of Civil Engineers, pp. 3826-3834.
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In this paper, detailed laboratory investigations were conducted on coal wash produced at coal mine, Wollongong, New South Wales, Australia. Geotechnical tests were conducted to determine the particle size distribution, compaction characteristics, shear resistance and collapse potential. The compaction tests were conducted under dry and submerged condition to examine the compactability and the strength of the coal wash. The test shows that compacted coal wash has good potential as effective fill for embankments, and land reclamation. Although when coal wash is compacted under submerged condition, increased level of compaction has minimal effect. © 2012 American Society of Civil Engineers.
Jiang, X, Li, Y, Li, J & Wang, J 1970, 'Electromechanical Modeling of a PZT Disc-type Energy Harvester for Large Force Vibration', PROCEEDINGS OF THE FIRST INTERNATIONAL CONFERENCE ON MECHATRONIC SYSTEM AND MEASUREMENT TECHNOLOGY, 1st International Conference on Mechatronic System and Measurement Technology, SCIENCE PRESS USA INC, Nanjing, PEOPLES R CHINA, pp. 411-416.
Kabiri, K, Pradhan, B, Rezai, H, Ghobadi, Y & Moradi, M 1970, 'Fluctuation of Sea Surface Temperature in the Persian Gulf and its impact on coral reef communities around Kish Island', 2012 IEEE Colloquium on Humanities, Science and Engineering (CHUSER), 2012 IEEE Colloquium on Humanities, Science and Engineering (CHUSER), IEEE, pp. 164-167.
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Khabbaz, H & Fatahi, B 1970, 'General and Technical Considerations for Implementing High Speed Rail Systems in Australia', PROCEEDINGS OF THE 2012 AGS SYMPOSIUM: ADVANCES IN GEOTECHNICAL ASPECTS OF ROADS AND RAILWAYS, AGS Symposium Advances in Geotechnical Aspects of Roads and Railways, The Australian Geomechanics Society, Darling Harbour, NSW, Australia, pp. 67-78.
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Australia has a number of medium speed rail services such as the Prospector, which runs from East Perth to Kalgoorlie, at speeds of up to 160 km/hr. Speeds as high as 210 km/hr have been reached by the tilt train from Brisbane to Rockhampton. Although there are a few medium speed rail systems in Australia, there is not a passenger rail transport with the high transit speeds seen in other countries. This paper presents the feasibility of implementing high speed rail systems in Australia by looking at the main elements that a high speed train is composed of. This paper also reviews the performance of high speed rail systems around the world and the factors contributed to their success made them successful. The main objective of this study is to look at how the solutions from overseas and how the technical requirements particularly the geotechnical aspects of tracks for a high speed rail system can be applied in Australian existing and new tracks. Australia has its own unique demographic, geographic and economic characteristics and the aim is to identify where there are overlaps between Australiaâs characteristics and countries with high speed rail systems. High speed rail transport might not necessarily be one the best solutions for the transportation at present in Australia, but it can be what a nation needs to succeed in its future transportation system.
Khabbaz, H, Fatahi, B & Nucifora, C 1970, 'Finite Element Methods against Limit Equilibrium Approaches for Slope Stability Analysis', Proceedings of the 11th Australia - New Zealand Conference on Geomechanics - Ground Engineering in a Changing World (ANZ 2012), Australia New Zealand Conference on Geomechanics, Geomechanical Society and New Zealand Geotechnical Society, Melbourne, Australia, pp. 1293-1298.
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A number of powerful numerical models, including limit equilibrium and finite element (FE) methods, have been developed for slope stability analysis in recent decades. The limit equilibrium method contains several limitations, yet is considered the most common approach. However, the advancement of technology has increased the use of the finite element method as it embraces a wider range of features. The limit equilibrium software, SLOPE/W, and the FE program PLAXIS are two common software programs currently employed in geotechnical engineering. Slope analysis using the limit equilibrium method involves a series of slip surfaces dividing ground into vertical slices, and using the static equilibrium equations to calculate the factor of safety (FOS) and stresses for each slice. PLAXIS requires the input of soil properties and elastic-plastic parameters of elements. In this study the properties of a heterogeneous slope, consisting of general fill embankment over soft, slightly overconsolidated clay is implemented in each program. The FOS of slopes is determined for subsequent design requirements, and results are analysed and comparisons are conducted. The effect of Youngâs modulus on the FOS is also discussed. Recommendations are provided based on the results and previously published findings. The contribution of this paper is beneficial to geotechnical engineers, as it discusses the suitability and limitations of each method and assesses reliability of model outputs for slope stability analyses.
Latif, ZA, Aman, SNA & Pradhan, B 1970, 'Landslide susceptibility mapping using LiDAR derived factors and frequency ratio model: Ulu Klang area, Malaysia', 2012 IEEE 8th International Colloquium on Signal Processing and its Applications, 2012 IEEE 8th International Colloquium on Signal Processing & its Applications (CSPA), IEEE, pp. 378-382.
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Maali, Y, Rafiei, A, Abolhasan, M, Franklin, D & Safaei, F 1970, 'A Fuzzy Logic Node Relocation Model in WSNs', 6TH INTERNATIONAL CONFERENCE ON SIGNAL PROCESSING AND COMMUNICATION SYSTEMS (ICSPCS'2012), International Conference on Signal Processing and Communication Systems, IEEE, Gold Coast, Australia, pp. 1-6.
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Hostile and harsh environments may preclude the possibility of manual redeployment of new sensor nodes, especially in the areas suffering from widespread damage and unbalanced node deployments. Distributed local relocations of currently deployed nodes is one promising solution to this problem. By using expected global node density and force-based movement algorithms inspired by the laws of nature, it is possible to address the aforementioned challenge. Force-based movement algorithms steer nodes towards their new locations based on the aggregation of exerted virtual forces on the node from their neighborhood. Some implicit assumptions about nodes' global status such as expected global node density are not realistic in dynamic and harsh environments. Thus, to conform to the uncertain nature and local interactions of nodes, a combination of radial-angular force fuzzy movement algorithms is suggested. The performance of the proposed model in terms of percentage of coverage, uniformity and average movement under three different boundary conditions are evaluated and compared with distributed self-spreading algorithms (DSSA). The results show that the simple fuzzy movement algorithm either outperforms or matches DSSA even if nodes don't benefit from expected global node density as in DSSA. © 2012 IEEE.
Mirlatifi, S & Fatahi, B 1970, 'Numerical Analysis of Geosynthetic Reinforced Soil Wall as Bridge Abutment', Proceedings of the 11th Australia - New Zealand Conference on Geomechanics - Ground Engineering in a Changing World (ANZ 2012), Australia New Zealand Conference on Geomechanics, Geomechanical Society and New Zealand Geotechnical Society, Melbourne, Australia, pp. 1383-1388.
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This paper presents the finite element analysis of a geosynthetic reinforced soil wall as a bridge abutment built in Tehran, and the predictions are compared with the available field measurements. This abutment is analysed using both Limit Equilibrium Method (LEM) for stability analysis and Finite Element Method (FEM) for deformation analysis. Two dimensional plane strain finite element model is adopted for the simulation. Polyvinyl Alcohol (PVA) geogrid with high tensile moduli and low creep characteristics has been adopted in this project to limit the deformation of the bridge abutment. In this model, the backfill soil and geogrids simulated adopting Mohr-Coulomb model, and the elasto-plastic material model that only works in tension, respectively. Bridge abutments can be stabilised by including geosynthetic layers with high tensile moduli satisfying both stability and deformation criteria reducing the construction cost and time, post construction deformations, and future maintenance cost.
Movassaghi, S, Abolhasan, M, Lipman, J & IEEE 1970, 'Energy Efficient Thermal and Power Aware (ETPA) Routing in Body Area Networks', 2012 IEEE 23RD INTERNATIONAL SYMPOSIUM ON PERSONAL INDOOR AND MOBILE RADIO COMMUNICATIONS (PIMRC), IEEE International Symposium on Personal and Indoor Mobile Radio Conference, IEEE, Sydney, pp. 1108-1113.
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Research on routing in a network of intelligent, lightweight, micro and nano-technology sensors deployed in or around the body, namely Body Area Network (BAN), has gained great interest in the recent years. In this paper, we present an energy efficient, thermal and power aware routing algorithm for BANs named Energy Efficient Thermal and Power Aware routing (ETPA). ETPA considers a node's temperature, energy level and received power from adjacent nodes in the cost function calculation. An optimization problem is also defined in order to minimize average temperature rise in the network. Our analysis demonstrates that ETPA can significantly decrease temperature rise and power consumption as well as providing a more efficient usage of the available resources compared to the most efficient routing protocol proposed so far in BANs, namely PRPLC. Also, ETPA has a considerably higher depletion time that guarantees a longer lasting communication among nodes. © 2012 IEEE.
Movassaghi, S, Arab, P & Abolhasan, M 1970, 'Wireless technologies for Body Area Networks: Characteristics and challenges', 2012 International Symposium on Communications and Information Technologies (ISCIT), 2012 International Symposium on Communications and Information Technologies (ISCIT), IEEE, Queensland, Australia, pp. 42-47.
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Body Area Networks (BANs) are an exciting new networking technology expected to cause a dramatic shift on the way people think and manage their health and the way they benefit from information technology and advancements in a wide range of medical and non-medical applications. Since BANs are in the early stages of their development, a number of fundamental features and challenges need to be investigated to overcome the stringent requirements tied with this technology. Also the choice of an appropriate wireless technology is required to enable BAN systems to communicate physiological data. This paper provides an overview of existing wireless technologies applicable to BANs. The specific features of each wireless technology is described along with their major advantages, drawbacks and most appropriate application in BANs. Comparison of the described technologies are provided from different aspects of frequency range, data rate, coverage area, modulation technique and network topology.
Mukunthan, A, Cooper, C, Safaei, F, Franklin, D, Abolhasan, M & IEEE 1970, 'Studying the Impact of the CORNER Propagation Model on VANET Routing in Urban Environments', 2012 IEEE VEHICULAR TECHNOLOGY CONFERENCE (VTC FALL), IEEE Vehicular Technology Conference, IEEE, Québec City, QC, Canada, pp. 1-5.
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Nguyen, V & Blumenstein, M 1970, 'A Compact Size Feature Set for the Off-Line Signature Verification Problem', 2012 10th IAPR International Workshop on Document Analysis Systems, 2012 10th IAPR International Workshop on Document Analysis Systems (DAS), IEEE, Gold Coast, Australia, pp. 261-265.
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With increasing computational power, researchers in the area of off-line signature verification have been able to investigate feature extraction techniques that produce large-dimensional feature vectors. However, a large feature vector is not necessarily associated with high performance. This paper investigates the performance of a small feature set consisting of 33 feature values. In the experiments using Support Vector Machines (SVMs), an average error rate (AER) of 16.80% was obtained together with a low false acceptance rate (FAR) for random forgeries of 0.19%. The significant reduction of the error rate was obtained when the proposed global features were employed, which demonstrates their astonishingly high discriminant power. These results suggest that the use of global features for the off-line signature verification problem is worth further investigation. © 2012 IEEE.
Nimbalkar, S, Indraratna, B & Rujikiatkamjorn, C 1970, 'Performance Improvement of Railway Ballast Using Shock Mats and Synthetic Grids', GeoCongress 2012, GeoCongress 2012, American Society of Civil Engineers, JAPAN, pp. 1622-1631.
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Railways in Australia still play a significant role in the intrastate transport of passenger and freight. In recent years, the increased demand for heavier and faster trains has posed greater challenges to railway industry to improve efficiency and stability of track while decreasing track maintenance costs. The ballast layer plays a key role in governing the stability and performance of rail tracks. However, high traffic induced stresses always result in large plastic deformations and degradation of ballast, which in turn leads to significant loss of track stability. This problem becomes severe under impact loading because it accelerates the breakage of ballast particles. Therefore, understanding the complex mechanisms involved with the transfer of impact loads on the substructure and their effect on ballast breakage and degradation is essential when designing new tracks and rehabilitating existing ones. The field trial in Bulli (near Wollongong) demonstrated that in case of train with wheel flats, extremely high pressure can be transmitted to the ballast bed. Installing resilient mats such as rubber pads (shock mats) in rail tracks can lead to attenuation of impact forces and subsequent mitigation of ballast degradation. In view of this, a series of laboratory tests using a high capacity drop-weight impact testing equipment has been carried out to evaluate the effectiveness of shock mats. This paper describes large-scale laboratory testing and full-scale instrumented field trial carried out to quantify the geotechnical behavior of ballast improved by using shock mats and synthetic grids respectively. © 2012 American Society of Civil Engineers.
Oberst, S & Lai, JCS 1970, 'Analysis of disc brake squeal: Progress and challenges', 19th International Congress on Sound and Vibration 2012, ICSV 2012, pp. 2874-2881.
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Brake squeal noise has been the subject of intense research efforts owing to concerns of car manufacturers caused by complaints lodged and warranty claim related costs arising from dissatisfied customers. Brake squeal is known to be fugitive, and often not repeatable, even under apparently similar operating conditions. The production of brake squeal is dependent on a large number of interacting parameters, such as the mechanical properties of the brake lining materials, contact conditions, wear, operating pressure and temperature which contribute to its often observed nonrepeatability. In this paper, an overview of the state-of-the-art understanding of brake squeal mechanisms and numerical analysis methods (primarily based on finite element analysis) for the prediction of brake squeal propensity is presented. The question of nonlinearity of brake squeal is raised in terms of analysing the mechanisms and how present solution methods reflect this degree of nonlinearity. This is complemented by a description of current industrial practice in the treatment of brake squeal which is, generally, managed on a case-by-case, trial-and-error basis using expensive equipment and time-consuming noise dynamometer and/or on-vehicle tests. The gaps between theory and industrial practice and, hence, challenges for brake squeal research are identified. Recommendations for bridging these gaps and improving the usefulness of current numerical methods for practical industrial use are proposed.
Oberst, S & Lai, JCS 1970, 'The role of nonlinearity in disc brake squeal', Proceedings - European Conference on Noise Control, pp. 1334-1339.
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The prediction of disc brake squeal propensity remains difficult despite significant progress made in the last two decades towards understanding its nature. Most of the numerical analysis of brake squeal is based on linear methods that have found some success in guiding the development of brakes in industry. One popular approach is the complex eigenvalue analysis using finite element models to predict unstable vibration modes. However, the complex eigenvalue analysis may over-predict or under-predict the number of unstable vibration modes and not all predicted unstable vibration modes will result in squeal. Therefore, extensive brake testing in noise dynamometers is required in order to ensure that the noise performance of brakes is acceptable. Although the analysis of brake squeal propensity is primarily based on linear approaches, it has been recognised that the operation of a brake contains a number of nonlinearities such as the excitation through the friction contact between the disc and pad, material properties, and operating conditions. The purpose of this paper is to provide an overview on nonlinearity as one mechanism of the cause of brake squeal and to discuss how such knowledge could be used to develop alternative strategies in numerical prediction of brake squeal propensity. © European Acoustics Association.
Odeh, N, Abolhasan, M, Safaei, F & Franklin, DR 1970, 'On the impact of RD link in resource allocation for multi-cell OFDMA cooperative relay networks with partial CSI.', ISCIT, International Symposium on Communications and Information Technologies, IEEE, Gold Coast, QLD, pp. 690-695.
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is paper investigates the impact of the relay-to-destination channel gain on subcarrier allocation for uplink OFDMA based cooperative relay networks using multiple amplify-and- forward (AF) relaying protocols. The closed form outage probability is derived for the system under partial channel state information (PCSI) and considering the presence of intercell interference (ICI). The results show that the impact of the link between the relay station and the destination is very low when the ICI is high. Hence, under this condition, the channel information of this link can be ignored during the resource allocation which significantly reduces the complexity of the resource allocation processes. Furthermore, this paper quantifies the level of interference at which the RD link can be ignored.
Pal, S, Alireza, A, Pal, U & Blumenstein, M 1970, 'Multi-script off-line signature identification', 2012 12th International Conference on Hybrid Intelligent Systems (HIS), 2012 12th International Conference on Hybrid Intelligent Systems (HIS), IEEE, Pine, India, pp. 236-240.
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In this paper, we present an empirical contribution towards the understanding of multi-script signature identification. In the proposed signature identification system, the signatures of Bengali (Bangla), Hindi (Devanagari) and English are considered for the identification process. This system will identify whether a claimed signature belongs to the group of Bengali, Hindi or English signatures. Zernike Moment and histogram of gradient are employed as two different feature extraction techniques. In the proposed system, Support Vector Machines (SVMs) are considered as classifiers for signature identification. A database of 2100 Bangla signatures, 2100 Hindi signatures and 2100 English signatures are used for experimentation. Two different results based on two different feature sets are calculated and analysed. The highest accuracy of 92.14% is obtained based on the gradient features using 4200 (1400 Bangla +1400 Hindi + 1400 English) samples for training and 2100 (700 Bangla +700 Hindi +700 English) samples for testing. © 2012 IEEE.
Pal, S, Blumenstein, M & Pal, U 1970, 'Hindi Off-Line Signature Verification', 2012 International Conference on Frontiers in Handwriting Recognition, 2012 International Conference on Frontiers in Handwriting Recognition (ICFHR), IEEE, Bari, Italy, pp. 373-378.
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Handwritten Signatures are one of the widely used biometrics for document authentication as well as human authorization. The purpose of this paper is to present an offline signature verification system involving Hindi signatures. Signature verification is a process by which the questioned signature is examined in detail in order to determine whether it belongs to the claimed person or not. Despite of substantial research in the field of signature verification involving Western signatures, very little attention has been dedicated to non-Western signatures such as Chinese, Japanese, Arabic, Persian etc. In this paper, the performance of an off-line signature verification system involving Hindi signatures, whose style is distinct from Western scripts, has been investigated. The gradient and Zernike moment features were employed and Support Vector Machines (SVMs) were considered for verification. To the best of the authors' knowledge, Hindi signatures have never been used for the task of signature verification and this is the first report of using Hindi signatures in this area. The Hindi signature database employed for experimentation consisted of 840 (35×24) genuine signatures and 1050 (35×30) forgeries. An encouraging accuracy of 7.42% FRR and 4.28% FAR were obtained following experimentation when the gradient features were employed. © 2012 IEEE.
Pal, S, Chanda, S, Pal, U, Franke, K & Blumenstein, M 1970, 'Off-line signature verification using G-SURF', 2012 12th International Conference on Intelligent Systems Design and Applications (ISDA), 2012 12th International Conference on Intelligent Systems Design and Applications (ISDA), IEEE, Kochi, India, pp. 586-591.
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In the field of biometric authentication, automatic signature identification and verification has been a strong research area because of the social and legal acceptance and extensive use of the written signature as an easy method for authentication. Signature verification is a process in which the questioned signature is examined in detail in order to determine whether it belongs to the claimed person or not. Signatures provide a secure means for confirmation and authorization in legal documents. So nowadays, signature identification and verification becomes an essential component in automating the rapid processing of documents containing embedded signatures. Sometimes, part-based signature verification can be useful when a questioned signature has lost its original shape due to inferior scanning quality. In order to address the above-mentioned adverse scenario, we propose a new feature encoding technique. This feature encoding is based on the amalgamation of Gabor filter-based features with SURF features (G-SURF). Features generated from a signature are applied to a Support Vector Machine (SVM) classifier. For experimentation, 1500 (50x30) forgeries and 1200 (50x24) genuine signatures from the GPDS signature database were used. A verification accuracy of 97.05% was obtained from the experiments. © 2012 IEEE.
Pal, S, Nguyen, V, Blumenstein, M & Pal, U 1970, 'Off-line Bangla signature verification', Proceedings - 10th IAPR International Workshop on Document Analysis Systems, DAS 2012, IEEE International Joint Conference on Neural Networks, IEEE, USA, pp. 282-286.
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In the field of information security, biometric systems play an important role. Within biometrics, automatic signature identification and verification has been a strong research area because of the social and legal acceptance and extensive use of the written signature as an individual authentication. Signature verification is a process in which the questioned signature is examined in detail in order to determine whether it belongs to the claimed person or not. Despite substantial research in the field of signature verification involving Western signatures, very few works have been dedicated to non-Western signatures such as Chinese, Japanese, Arabic, or Persian etc. In this paper, the performance of an off-line signature verification system involving Bangla signatures, whose style is distinct from Western scripts, was investigated. The Gaussian Grid feature extraction technique was employed for feature extraction and Support Vector Machines (SVMs) were considered for classification. The Bangla signature database employed in the experiments consisted of 3000 forgeries and 2400 genuine signatures. An encouraging accuracy of 90.4% was obtained from the experiments. © 2012 IEEE.
Pal, S, Pal, U & Blumenstein, M 1970, 'Off-line English and Chinese signature identification using foreground and background features', The 2012 International Joint Conference on Neural Networks (IJCNN), 2012 International Joint Conference on Neural Networks (IJCNN 2012 - Brisbane), IEEE.
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In the field of information security, the usage of biometrics is growing for user authentication. Automatic signature recognition and verification is one of the biometric techniques, which is only one of several used to verify the identity of individuals. In this paper, a foreground and background based technique is proposed for identification of scripts from bi-lingual (English/Roman and Chinese) off-line signatures. This system will identify whether a claimed signature belongs to the group of English signatures or Chinese signatures. The identification of signatures based on its script is a major contribution for multi-script signature verification. Two background information extraction techniques are used to produce the background components of the signature images. Gradient-based method was used to extract the features of the foreground as well as background components. Zernike Moment feature was also employed on signature samples. Support Vector Machine (SVM) is used as the classifier for signature identification in the proposed system. A database of 1120 (640 English+480 Chinese) signature samples were used for training and 560 (320 English+240 Chinese) signature samples were used for testing the proposed system. An encouraging identification accuracy of 97.70% was obtained using gradient feature from the experiment. © 2012 IEEE.
Pourghasemi, HR, Moradi, HR, Mohammadi, M, Pradhan, B, Mostafazadeh, R & Goli Jirandeh, A 1970, 'Landslide hazard assessment using remote sensing data, GIS and weights-of-evidence model (South of Golestan Province, Iran)', Asia Pacific Conference on Environmental Science and Technology (APEST 2012), Advances in Biomedical Engineering, pp. 30-36.
Pourghasemi, HR, Pradhan, B & Gokceoglu, C 1970, 'Remote Sensing Data Derived Parameters and its Use in Landslide Susceptibility Assessment Using Shannon’s Entropy and GIS', Applied Mechanics and Materials, Trans Tech Publications, Ltd., pp. 486-491.
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In recent years, the growth of urban populations in hazardous areas has increased the impact of natural disasters in both developed and developing countries. The purpose of the current study is to assess the landslide susceptibility in Kalaleh township of Golestan province, Iran. In this study the Shannon’s entropy approach was applied. A total of 82 landslide locations were identified primarily from aerial photographs and field surveys. Then eighteen landslides conditioning factors were prepared in GIS. These landslide conditioning factors are: slope degree, slope aspect, altitude, plan curvature, profile curvature, tangential curvature, surface area ratio (SAR), lithology, land use, soil texture, distance from faults, distance from rivers, distance from roads, fault density, road density, topographic wetness index (TWI), stream power index (SPI), and sediment transport index (STI). Using these conditioning factors, landslide susceptibility index was calculated using Shannon’s entropy. For model validation, the results of the analyses were then compared with the field-verified landslide locations. Additionally, the receiver operating characteristics (ROC) curves for landslide susceptibility maps were drawn and the area under curve values was calculated. Verification results showed 82.15% accuracy. According to the results of the AUC (area under curve) evaluation, the map produced exhibits satisfactory properties.
Pradhan, B & Kabiri, K 1970, 'Spectral and spatial resolution analysis of multi sensor satellite data for coral reef mapping: Tioman Island, Malaysia', 39th COSPAR Scientific Assembly, p. 1533.
Pradhan, B, Latif, ZA & Aman, SNA 1970, 'Application of Airborne LiDAR-Derived Parameters and Probabilistic-Based Frequency Ratio Model in Landslide Susceptibility Mapping', Applied Mechanics and Materials, Trans Tech Publications, Ltd., pp. 442-447.
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The escalating number of occurrences of natural hazards such as landslides has raised a great interest among the geoscientists. Due to the extremely high number of point’s returns, airborne LiDAR permits the formation of more accurate DEM compared to other space borne and airborne remote sensing techniques. This study aims to assess the capability of LiDAR derived parameters in landslide susceptibility mapping. Due to frequent occurrence of landslides, Ulu Klang in Selangor state in Malaysia has been considered as application site. A high resolution of airborne LiDAR DEM was constructed to produce topographic attributes such as slope, curvature and aspect. These data were utilized to derive secondary deliverables of landslide parameters such as topographic wetness index (TWI), surface area ratio (SAR) and stream power index (SPI). A probabilistic based frequency ratio model was applied to establish the spatial relationship between the landslide locations and each landslide related factors. Subsequently, factor ratings were summed up to yield Landslide Susceptibility Index (LSI) and finally a landslide susceptibility map was prepared. To test the model performance, receiver operating characteristics (ROC) curve was carried out together with area under curve (AUC) analysis. The produced landslide susceptibility map demonstrated that high resolution airborne LiDAR data has huge potential in landslide susceptibility mapping.
Rafiei, A, Abolhasan, M, Franklin, DR & Safaei, F 1970, 'WSNs Coverage Hole Partial Recovery by Nodes' Constrained and Autonomous Movements Using Virtual alpha-chords', ICWMC 2012, The Eighth International Conference on Wireless and Mobile Communications, International Conference on Wireless and Mobile Communications (ICWMC), XPS (Xpert Publishing Services) / IARIA, Venice, pp. 74-80.
Rujikiatkamjorn, C, Heitor, A & Indraratna, B 1970, 'The effect of dry unit weight, suction and imparted energy on the modulus of a compacted mixture of sand and kaolin', ADVANCES IN TRANSPORTATION GEOTECHNICS II, 2nd International Conference on Transportation Geotechnics (ICTG), CRC Press, JAPAN, pp. 440-445.
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Rujikiatkamjorn, C, Indraratna, B & Bergado, DT 1970, '3D Numerical Modeling of Hexagonal Wire Mesh Reinforced Embankment on Soft Bangkok Clay', GeoCongress 2012, GeoCongress 2012, American Society of Civil Engineers, pp. 2263-2272.
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The numerical modeling of the full scale test embankment reinforced with hexagonal wire mesh was analyzed using finite difference method under threedimensional (3D) conditions to reflect the actual embankment dimensions. In the analysis, the 3D finite difference simulation using 5 times of vertical laboratory permeability can reasonably predict its behavior on soft foundation. In comparison with the field measurements, the predicted results from 3D analysis reasonably agreed with measured data including vertical settlement, excess pore pressures and lateral displacements. Thus, the actual embankment geometry and the selected permeability influenced the behavior of the reinforced embankment constructed on soft ground foundation. The simulated maximum tension lines in the reinforcements tend to follow the coherent gravity failure plane. The maximum tension at the bottom of the reinforced embankment occurred near midpoint portion away from the facing due to the settlement profile of the soft soil foundation. © 2012 American Society of Civil Engineers.
Rujikiatkamjorn, C, Indraratna, B & Fatahi, B 1970, 'Numerical prediction of unsaturated ground behavior influenced by vegetation and vacuum consolidation', 5th Asia-Pacific Conference on Unsaturated Soils 2012, Asia-Pacific Conference on Unsaturated Soils Theory and Practice, Kasetsart University, Thailand, pp. 701-706.
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Bioengineering including native vegetation is an ancient method of improving the stability of slopes. In modern railway engineering, this technique is re-captured for increasing the soil stiffness and shear strength of subgrade beneath rail tracks. Currently this practice has become increasingly popular in Australia for stabilising railway corridors built over expansive clays and compressive soft soils. This paper looks at the stabilisation role by suction generated by both the natural vegetation and the artificial vacuum application using the numerical analysis. For demonstrating the role of native vegetation, a mathematical model for the rate of root water uptake was incorporated in the analysis. The soil moisture content distribution and the soil marric suction profile adjacent to the tree were numerically captured based on the general effective stress theory of unsaturated soil. For vacuum application, the equivalent plane strain theory was employed to simulate radial consolidation and artificially applied suction. The performance of both techniques on track constructed on soft formation was discussed and compared in terms of settlement and associated pore pressure.
Rujikiatkamjorn, C, Indraratna, B, Ngo, NT & Coop, M 1970, 'A laboratory study of railway ballast behaviour under various fouling degree', GA 2012 - 5th Asian Regional Conference on Geosynthetics: Geosynthetics for Sustainable Adaptation to Climate Change, pp. 507-514.
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This paper presents a laboratory study of interface behavior between ballast and geogrid under various degree of fouling by coal fines. The stress-displacement behaviour of fresh and fouled ballast with geogrid was investigated through a series of large-scale direct shear tests where the fouling degree varied from 0% to 95% Void Contamination Index (VCI), at normal stresses ranging from 15kPa to 75kPa. The results showed that geogrid enhances the shear strength and increases apparent angle of shearing resistance, while only slightly reduces the vertical displacement of the composite geogrid-ballast system. However, when ballast was contaminated by coal fines, the influences of geogrid reinforcement decreased in proportion to the increasing level of fouling. A conceptual normalized shear strength model was introduced to calculate this decrease in peak shear stress and peak angle of shearing resistance caused by coal fouling.
Rujikiatkamjorn, C, Ngo, NT, Indraratna, B, J. S, V & Coop, M 1970, 'Simulation of Fresh and Fouled Ballast Behavior using Discrete Element Method', Proceedings of the International Conference on Ground Improvement & Ground Control, International Conference on Ground Improvement & Ground Control, Research Publishing Services, pp. 1585-1591.
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Sabbagh, AAL, Braun, R & Abolhasan, M 1970, 'A mobility optimization CRRM approach for Next Generation Wireless Networks', 2012 International Conference on Computer & Information Science (ICCIS), 2012 International Conference on Computer & Information Science (ICCIS), IEEE, Kuala Lumpur, Malaysia, pp. 609-613.
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Next Generation Wireless Networks (NGWN) are predicted to be heterogeneous in nature. This is achieved through the integration of different Radio Access Technologies (RATs) over a common platform. Common Radio Resource Management (CRRM) was proposed to manage radio resource utilization in heterogeneous wireless networks and to provide required Quality of Service (QoS) for allocated calls. RAT selection algorithms are an integral part of the CRRM algorithms. Their role is to decide, when a new or Vertical Handover (VHO) call is requested, which of the available RATs is most suitable to fit the need of the incoming call and when to admit them. In this paper, we propose an intelligent hybrid RAT selection approach for mobility optimization (patent pending) which includes sorting available RATs, collecting information on each RAT using the IEEE P1900.4 Protocol, and making decisions for selecting the most suitable RAT for incoming calls. A comparison for the performance of centralized load-balancing, distributed and the proposed mobility optimization algorithms is presented in terms of new calls blocking probability, VHO calls dropping probability and satisfactions probability. Simulation results show that the proposed algorithm performs better than the centralized load-balancing and distributed algorithms in terms of blocking, dropping and satisfactions probabilities. © 2012 IEEE.
Sadeghi Hokmabadi, A, Fatahi, B, Far, H & Samali, B 1970, 'Effects of soil-pile-structure interaction on seismic response of moment resisting buildings on soft soil', 3rd International Conference on New Developments in Soil Mechanics and Geotechnical Engineering, International Conference on Soil Mechanics and Geotechnical Engineering, Near East University Press, Turkey, Turkey, pp. 377-385.
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Dynamic response of structures sitting on soft soils is influenced by the soil properties, and the response is significantly different to the fixed base condition owing to the interaction between the ground and the structure, In order to study this effect, a fifteen storey moment resisting building frame, representing a conventional type of regular mid-rise building frame, resting ,on soil type Ee according to Australian Earthquake action code with the shear wave velocity equal to 150 mls is adopted. The numerical analysis using FLAC2D software is carried out for three different cases, namely: (1) fixed-base structure representing the situation excluding the soil-structure interaction (SSI); (2) structure supported by shallow foundation on soft soil; and (3) structure supported by pile foundation in soft soil. Benchmark earthquakes including the 1995 Kobe, the 1994 Northridge, the 1968 Hachinohe, and the 1940 EI Centro earthquakes are adopted. Results indicate that considering soil-structure interaction in both cases with shallow and pile fouudations is vital, and the conventional desigu procedure excluding soil-structure interaction is not adequate to guarantee the structural safety for the moment resisting buildings resting on the soft soil.
Sharma, N, Pal, U & Blumenstein, M 1970, 'Recent Advances in Video Based Document Processing: A Review', 2012 10th IAPR International Workshop on Document Analysis Systems, 2012 10th IAPR International Workshop on Document Analysis Systems (DAS), IEEE, Gold Coast, Australia, pp. 63-68.
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Extraction and recognition of text present in video has become a very popular research area in the last decade. Generally, text present in video frames is of different size, orientation, style, etc. with complex backgrounds, noise, low resolution and contrast. These factors make the automatic text extraction and recognition in video frames a challenging task. A large number of techniques have been proposed by various researchers in the recent past to address the problem. This paper presents a review of various state-of-the-art techniques proposed towards different stages (e.g. detection, localization, extraction, etc.) of text information processing in video frames. Looking at the growing popularity and the recent developments in the processing of text in video frames, this review imparts details of current trends and potential directions for further research activities to assist researchers. © 2012 IEEE.
Sharma, N, Shivakumara, P, Pal, U, Blumenstein, M & Tan, CL 1970, 'A new method for arbitrarily-oriented text detection in video', Proceedings - 10th IAPR International Workshop on Document Analysis Systems, DAS 2012, International Workshop on Document Analysis Systems, IEEE, Institute of Electrical and Electronics Engineers, Gold Coast, Australia, pp. 74-78.
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Text detection in video frames plays a vital role in enhancing the performance of information extraction systems because the text in video frames helps in indexing and retrieving video efficiently and accurately. This paper presents a new method for arbitrarily-oriented text detection in video, based on dominant text pixel selection, text representatives and region growing. The method uses gradient pixel direction and magnitude corresponding to Sobel edge pixels of the input frame to obtain dominant text pixels. Edge components in the Sobel edge map corresponding to dominant text pixels are then extracted and we call them text representatives. We eliminate broken segments of each text representatives to get candidate text representatives. Then the perimeter of candidate text representatives grows along the text direction in the Sobel edge map to group the neighboring text components which we call word patches. The word patches are used for finding the direction of text lines and then the word patches are expanded in the same direction in the Sobel edge map to group the neighboring word patches and to restore missing text information. This results in extraction of arbitrarily-oriented text from the video frame. To evaluate the method, we considered arbitrarily-oriented data, non-horizontal data, horizontal data, Hua's data and ICDAR-2003 competition data (Camera images). The experimental results show that the proposed method outperforms the existing method in terms of recall and f-measure. © 2012 IEEE.
Shashikant, V, Shariff, ARM, Nordin, L & Pradhan, B 1970, 'Estimation of above ground biomass of oil palm trees by PALSAR', 2012 IEEE Colloquium on Humanities, Science and Engineering (CHUSER), 2012 IEEE Colloquium on Humanities, Science and Engineering (CHUSER), IEEE, pp. 838-841.
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Shashikant, V, Shariff, ARM, Nordin, L & Pradhan, B 1970, 'NDVI of oil palm trees by landsat-5 Imagery', 33rd Asian Conference on Remote Sensing 2012, ACRS 2012, pp. 1876-1879.
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Oil Palm plantations in Malaysia are managed to allow the optimum yield rate. Most plantations have a series of techniques for managing the palms. Good management provides sound recommendations and reliable management decisions of the oil palm trees. One of the techniques is the application of remote sensing which is used as a tool to determine decisions about the oil palm plantations. It is important that decisions to manage these palms are made based on fair and reliable information. Landsat-5 has capability to determine some of these information and facts. NDVI derived from the Landsat-5 can be used to determine the greenness of these palm plantations. Oil palm trees greenness can be obtained. This information can be used in determining the fertilizer application that contributes to the yield of oil palm plantations.
Sheng, D & Zhou, A-N 1970, 'Modeling Unsaturated Soil Behaviour in Stress-Saturation Space', GeoCongress 2012, GeoCongress 2012, American Society of Civil Engineers, pp. 2442-2451.
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This paper presents an alternative approach for interpreting unsaturated soil behaviour. In this approach, all constitutive laws are built in the space of stress versus degree of saturation. A new volume change equation is proposed in terms of stress and degree of saturation, to give a better explanation to the non-linear change of soil compressibility under constant suctions. The soil compression index is assumed to be a function of the effective degree of saturation. The yield surface is established in the plane of the effective degree of saturation and the Bishop effective stress. The proposed model is then validated against a variety of experimental data in literature. © 2012 American Society of Civil Engineers.
Suwanwiwat, H, Nguyen, V & Blumenstein, M 1970, 'Off-line Restricted-Set Handwritten Word Recognition for Student Identification in a Short Answer Question Automated Assessment System', 2012 12TH INTERNATIONAL CONFERENCE ON HYBRID INTELLIGENT SYSTEMS (HIS), International Conference on Hybrid Intelligent Systems, IEEE, Institute of Electrical and Electronics Engineers, Pune, India, pp. 167-172.
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Handwriting recognition is one of the most intensive areas of study in the field of pattern recognition. Many applications are able to benefit from a robust off-line handwriting recognition technique. An automatic off-line assessment system and a writer identification system are two of those applications. Off-line automatic assessment systems can be an aid for teachers in the marking process; they can reduce the time consumed by the human marker. There has only been limited work undertaken in developing off-line automatic assessment systems using handwriting recognition, and none in developing student identification systems, even though such systems would clearly benefit the education sector. In order to develop a complete off-line automatic assessment system, student identification using full student names is proposed in this paper. The Gaussian Grid and Modified Direction Feature Extraction Techniques are investigated in order to develop the proposed system. The recognition rates achieved using both techniques are encouraging (up to 99.08% for the Modified Direction feature extraction technique, and up to 98.28% for the Gaussian Grid feature extraction technique. © 2012 IEEE.
Tabatabaiefar, HR, Fatahi, B & Samali, B 1970, 'Effects of soil dynamic properties and bedrock depth on seismic response of building frames incorporation soil-structure interaction', 5th Asia-Pacific Conference on Unsaturated Soils 2012, Asian-Pacific conferences on unsaturated soils, Kasetsart University, Pattaya, Thailand, pp. 504-510.
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In this study, a ten storey moment resisting building frame, resting on a shallow foundation, is selected in conjunction with three soil types with the shear wave velocities less than 600m/s, representing classes Ce, De and Ee, according to AS 1170.4. Different bedrock depths including 10m, 20m, and 30 m are employed in the numerical modelling using finite difference software FLAC 2D. Fully nonlinear dynamic analysis under influence of different earthquake records is conducted, and the results of the three different cases are compared and discussed. The results indicate that the dynamic properties of the subsoil such as shear wave velocity as well as bedrock depth play significant roles in seismic response of the building frames under the influence of soil-structure interaction. As the shear wave velocity of the subsoil decreases and bedrock depth increases, lateral deflections and inter-storey drifts of the structures increase. The mentioned effects can change the performance level of the structures from life safe to near collapse or total collapse. Therefore, the conventional design procedure excluding SSI is no longer adequate to guarantee the structural safety for the building frames resting on soft soil deposits.
Tennakoon, N, Indraratna, B, Nimbalkar, S & Rujikiatkamjorn, C 1970, 'Deformation and Degradation of Clay fouled Ballast Subjected to Monotonic Loading', Proceedings of the International Conference on Ground Improvement & Ground Control, International Conference on Ground Improvement & Ground Control, Research Publishing Services.
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Yan, N, Li, J, Dackermann, U & Samali, B 1970, 'Numerical and experimental investigations of stress wave propagation in utility poles under soil influence', From materials to structures: Advancement through innovation, Australasian Conference on the Mechanics of Structures and Materials, CRC Press, Sydney, Australia, pp. 593-598.
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Over the past decades, different types of non-destructive testing (NDT) methods have been developed for the condition assessment of timber structures. Stress wave methods, which are based on stress wave propagation theory, are considered to be simple and cost-effective tools for identifying damage as well as embedment length of timber poles/piles. However, due to the lack of understanding on wave propagation in such structures, especially under the influence of surroundings such as soil, these methods encounter difficulties in producing reliable results. In this paper, an investigation was carried out on the wave propagation behaviour in utility timber poles under consideration of soil effects. The commercial finite element (FE) analysis software ANSYS was used to simulate stress wave propagation in a timber utility pole under the influence of soil. In order to verify the numerical findings, laboratory testing was also conducted in dual course with the numerical modelling.
Yang, C, Sheng, D & Carter, JP 1970, 'Hysteretic seepage analysis in unsaturated soil covers', 5th Asia-Pacific Conference on Unsaturated Soils 2012, pp. 463-468.
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This paper aims to study numerically the effect of hysteresis on the hydraulic behaviour of unsaturated soil covers. The Richards equation is coupled with the hysteretic soil water retention curve (SWRC), to describe the flow in unsaturated soils. A linear scanning curve is used to describe the hydraulic behaviour within the main hysteretic loop in unsaturated seepage problems. The proposed approach is implemented with the finite difference method. A comparison of the proposed hysteretic model with the traditional non-hysteretic model is carried out first. The non-hysteretic model using the main drying SWRC leads to significantly different results than the hysteretic model, further demonstrating the necessity of accounting for hysteresis in seepage analysis. A sensitivity analysis on the hysteresis ratio and the slope of the scanning curve is then carried out with the hysteretic model. Results show that hydraulic hysteresis cannot be neglected in the seepage analysis of soil covers composed of soils exhibiting significant hydraulic hysteresis. The proper determination of both the scanning curve and the initial hydraulic state plays a crucial role in the reliability of numerical simulations of soil covers subjected to cyclic drying and wetting. It is suggested that the proposed hysteretic model may be applied in the design and evaluation of the hydraulic performance of soil covers.
Zeng, J, Guo, Y, Zhu, J, Li, Y & Li, J 1970, 'Magnetic Hysteresis Properties Measurement for Magneto-Rheological Elastomer', the 13th International Conference on Electrorheological Fluids and Magnetorheological Suspensions: Book of Abstracts, Gazi University, Ankara, Turkey, pp. 1-2.
Zhao, J, Zhang, N, Ji, J & ASME 1970, 'FLUID INDUCED VIBRATION IN THE LIQUID-FILLED HYDRAULIC CIRCUIT OF PASSIVE INTERCONNECTED SUSPENSIONS', PROCEEDINGS OF THE ASME INTERNATIONAL MECHANICAL ENGINEERING CONGRESS AND EXPOSITION, 2011, VOL 8, International Mechanical Engineering Congress & Exposition, ASME, Denver, Colorado, USA, pp. 745-752.
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The fluid flow inside the liquid-filled pipe-guided hydraulic circuit of a Hydraulically Interconnected Suspension (HIS) often lead to vibrations of the whole pipeline and associated structures and hence become a source of structural noise. This paper presents an investigation of fluid induced vibration into the pipeline. The one-dimensional wave theory is employed to formulate the equations of motions that govern the dynamics of the fluid-structural system. Axial and one plane of lateral vibrations as well as the effects of shear deformation on the lateral vibration of the pipe are considered. The transfer matrix method (TMM) is applied to determine the steady state response of the fluid-structural system, which consists of various pipe sections, hose sections, damper valves, accumulators, supports and joints that connect separate pipe branches. The overall system transfer matrix including fluid and pipe mechanics is obtained by combining with field transfer matrices representing the motion of single pipe sections and hose sections and various point transfer matrices that describe specified junction conditions. The developed model of the hydraulic system is examined through simulations and laboratory based rig tests. The simulation results show the hydraulic components have apparent impact on the dynamics of combined pipe structural and fluid system. The experiments performed on a hydraulic circuit and the measured steady state responses of the circuit are compared with those obtained from the simulations. It is found that the developed model of the hydraulic system including the coupling with boundaries has a reasonable accuracy in the frequency range of interest. Copyright © 2011 by ASME.
Zhou, AN, Sheng, D & Carter, JP 1970, 'Modelling the dependency of soil-water characteristic curves on initial density', 5th Asia-Pacific Conference on Unsaturated Soils 2012, pp. 357-362.
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This paper presents a simple approach to quantify the effect of initial soil density on the soil-water characteristic curve (SWCC) of unsaturated soils. This approach is based on an incremental relationship between the degree of saturation and the initial voids ratio, which satisfies the intrinsic constraints for three-phase porous materials. The incremental relationship can be incorporated into existing SWCC equations to model the water retention behaviour for deformable soils. Only one additional parameter is introduced, which can be conveniently calibrated via conventional water retention tests. The SWCCs for the same soil at different initial voids ratios can be found using the proposed approach. The proposed approach is validated against experimental data from drying tests for both compacted and reconstituted soils. © 2012 IEEE.
