Abolhasan, M, Wysocki, T & Lipman, J 2005, 'A New Strategy to Improve Proactive Route Updates in Mobile Ad Hoc Networks', EURASIP Journal on Wireless Communications and Networking, vol. 2005, no. 5, pp. 828-837.
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This paper presents two new route update strategies for performing proactive route discovery in mobile ad hoc networks (MANETs). The first strategy is referred to as minimum displacement update routing (MDUR). In this strategy, the rate at which route updates are sent into the network is controlled by how often a node changes its location by a required distance. The second strategy is called minimum topology change update (MTCU). In this strategy, the route updating rate is proportional to the level of topology change each node experiences. We implemented MDUR and MTCU on top of the fisheye state routing (FSR) protocol and investigated their performance by simulation. The simulations were performed in a number of different scenarios, with varied network mobility, density, traffic, and boundary. Our results indicate that both MDUR and MTCU produce significantly lower levels of control overhead than FSR and achieve higher levels of throughput as the density and the level of traffic in the network are increased.
Cha, F, Jeng, DS, Blumenstein, M & Zhang, H 2005, 'Prediction of maximum wave-induced liquefaction in porous seabed using multi-artificial neural network model', Research Report - University of Sydney, Department of Civil Engineering, no. 854, pp. 1-29.
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In the last decades, considerable efforts have been devoted to the phenomenon of wave-induced liquefactions, because it is one of the most important factors for analysing the seabed and designing marine structures. Although numerous studies of wave-induced liquefaction have been carried out, comparatively little is known about the impact of liquefaction on marine structures. Furthermore, most previous researches have focused on complicated mathematical theories and some laboratory work. In the present study, a data dependent approach for the prediction of the wave-induced liquefaction depth in a porous seabed is proposed, based on a multi-artificial neural network (MANN) method. Numerical results indicate that the MANN model can provide an accurate prediction of the wave-induced maximum liquefaction depth with 10% of the original database. This study demonstrates the capacity of the proposed MANN model and provides coastal engineers with another effective tool to analyse the stability of the marine sediment.
Choudhury, D & Nimbalkar, S 2005, 'Seismic passive resistance by pseudo-dynamic method', Géotechnique, vol. 55, no. 9, pp. 699-702.
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Indraratna, B 2005, 'Addressing the Geotechnical Challenges Posed by Soft Clays', International Journal of Geomechanics, vol. 5, no. 2, pp. 85-86.
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Indraratna, B & Jayanathan, M 2005, 'Measurement of pore water pressure of clay-infilled rock joints during triaxial shearing', Géotechnique, vol. 55, no. 10, pp. 759-764.
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Indraratna, B, Golab, A, Glamore, W & Blunden, B 2005, 'Acid sulphate soil remediation techniques on the Shoalhaven River floodplain, Australia', Quarterly Journal of Engineering Geology and Hydrogeology, vol. 38, no. 2, pp. 129-142.
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A commonly used flood mitigation technique in coastal areas of Australia during the late 1960s was the installation of one-way floodgates on flood mitigation drains. In regions affected by acid sulphate soils (the oxidation of pyrite in the soil forms sulphuric acid), the floodgates prevent tidal carbonate/bicarbonate buffering of the drains and thereby create reservoirs of acidic water (pH < 4.5) that discharge during low tide. Several acid sulphate soil remediation techniques have been used in coastal lowland in southeastern NSW, Australia. Following extensive monitoring and finite element modelling of groundwater conditions and quality, fixed level V-notch weirs were installed at three elevations to maintain elevated groundwater levels. The weirs successfully maintained the groundwater level above the acid sulphate soils, preventing additional pyrite oxidation, and reduced the rate of discharge of acid to the drain. Following further monitoring, investigation into anaerobic acid sources, and finite element-based geochemical modelling, modified two-way floodgates that allow tidal ingress were installed. The modified floodgates were successful in buffering the drain water pH before discharging the drain water into adjacent waterways. Numerical analysis based on finite element modelling was extended to illustrate that saline intrusion into the surrounding soil (as a result of tidal ingress and acid buffering in the drains) was not a major concern for the pastureland or other agricultural activities.
Indraratna, B, Lackenby, J & Christie, D 2005, 'Effect of confining pressure on the degradation of ballast under cyclic loading', Géotechnique, vol. 55, no. 4, pp. 325-328.
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Indraratna, B, Lackenby, J & Christie, D 2005, 'Effect of confining pressure on the degradation of ballast under cyclic loading', Géotechnique, vol. 55, no. 4, pp. 325-328.
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Indraratna, B, Rujikiatkamjorn, C & Sathananthan, I 2005, 'Analytical and numerical solutions for a single vertical drain including the effects of vacuum preloading', Canadian Geotechnical Journal, vol. 42, no. 4, pp. 994-1014.
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A system of vertical drains combined with vacuum preloading is an effective method to accelerate soil consolidation by promoting radial flow. This study presents the analytical modeling of vertical drains incorporating vacuum preloading in both axisymmetric and plane strain conditions. The effectiveness of the applied vacuum pressure along the drain length is considered. The exact solutions applied on the basis of the unit cell theory are supported by finite element analysis using ABAQUS software. Subsequently, the details of an appropriate matching procedure by transforming permeability and vacuum pressure between axisymmetric and equivalent plane strain conditions are described through analytical and numerical schemes. The effects of the magnitude and distribution of vacuum pressure on soft clay consolidation are examined through average excess pore pressure, consolidation settlement, and time analyses. Lastly, the practical implications of this study are discussed.Key words: consolidation, finite element method, soft clay, vacuum preloading, vertical drains.
Indraratna, B, Rujikiatkamjorn, C & Sathananthan, I 2005, 'Radial consolidation of clay using compressibility indices and varying horizontal permeability', Canadian Geotechnical Journal, vol. 42, no. 5, pp. 1330-1341.
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A system of vertical drains, with surcharge load to accelerate consolidation by shortening the drainage path, is one of the most popular methods of soft ground improvement. The conventional radial consolidation theory (including smear and well resistance) has been commonly used to predict the behaviour of vertical drains in soft clay. Its mathematical formulation is based on the small strain theory; and for a given stress range, a constant volume compressibility (mv) and a constant coefficient of horizontal permeability (kh) are assumed. However, the value of mvvaries along the consolidation curve over a wide range of applied pressure (Δp). In the same manner, khalso changes with the void ratio (e). In this paper, the writers have replaced mvwith the compressibility indices (Ccand Cr), which define the slopes of the e log σ′ relationship. Moreover, the variation of the horizontal permeability coefficient (kh) with the void ratio (e) during consolidation is represented by the e log khrelationship that has a slope of Ck. In contrast to the conventional analysis, the current study highlights the influence of the Cc/Ck(or Cr/Ck) ratio and the preloading increment ratio (Δp/σi) on the consolidation process. The analytical predictions are compared with the experimental results when a large-scale consolidation chamber was used, and these predictions show good agreement with the measured data. Finally, an embankment case history taken from Muar Plains, Malaysia, is analysed on the basis of the current solution and compared with field measurements.Key words: compressibility, embankments, permeability, soft soils, soil consolidation, vertical...
Indraratna, B, Rujikiatkamjorn, C, Balasubramaniam, AS & Wijeyakulasuriya, V 2005, 'Chapter 7 Predictions and observations of soft clay foundations stabilized with geosynthetic drains and vacuum surcharge', Elsevier Geo-Engineering Book Series, vol. 3, no. C, pp. 199-229.
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This chapter starts with an introduction of a revised analytical model of radial drainage with vacuum preloading in both axisymmetric and plane strain conditions. Observed from large-scale radial drainage consolidation tests, the influence of vacuum pressure distribution along the drain length is examined through the dissipation of average excess pore pressure and associated settlement. The details of an appropriate conversion procedure by transforming permeability and vacuum pressure between axisymmetric and equivalent plane strain conditions are described through analytical and numerical schemes. The effects of the magnitude and distribution of vacuum pressure on soft clay consolidation are investigated on the basis of average excess pore pressure consolidation settlement, and time analyses. The writers describe a multi-drain plane strain finite element method analysis based on permeability conversion, which is employed to study the behavior of embankments stabilized at the site of the Second Bangkok International Airport with vacuum-assisted prefabricated vertical drains. In the field, a constant suction head is not always stable because of the occurrence of air leaks; therefore the magnitude of applied vacuum pressure was adjusted accordingly. The theoretical (numerical) predictions are compared with measured field data such as settlements, excess pore pressures, and lateral movements. The case history analysis employing the writers' model indicates improved accuracy of the predictions in relation to the field observations. The data indicate that the efficiency of the prefabricated vertical drains depends on the magnitude and distribution of vacuum pressure as well as on the extent of air leak protection provided in practice. © 2005 Elsevier Ltd. All rights reserved.
Indraratna, B, Sathananthan, I, Bamunawita, C & Balasubramaniam, AS 2005, 'Chapter 2 Theoretical and numerical perspectives and field observations for the design and performance evaluation of embankments constructed on soft marine clay', Elsevier Geo-Engineering Book Series, vol. 3, no. C, pp. 51-89.
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In this chapter, a two-demensional plane strain solution is adopted for the embankment analysis, which includes the effects of smear zone caused by mandrel driven vertical drains. The equivalent (transformed) permeability coefficients are incorporated in finite element codes, employing modified Cam-clay theory. Selected numerical studies have been carried out to study the effect of embankment slope, construction rate, and drain spacing on the failure of the soft clay foundation. Finally the observed and predicted performances of well-instrumented full-scale trial embankments built on soft Malaysian marine clay have been discussed in detail. The predicted results agree with the field measurements. © 2005 Elsevier Ltd. All rights reserved.
Indraratna, B, Sathananthan, I, Rujikiatkamjorn, C & Balasubramaniam, AS 2005, 'Analytical and Numerical Modeling of Soft Soil Stabilized by Prefabricated Vertical Drains Incorporating Vacuum Preloading', International Journal of Geomechanics, vol. 5, no. 2, pp. 114-124.
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This paper describes the analytical formulation of a modified consolidation theory incorporating vacuum pressure, and numerical modeling of soft clay stabilized by prefabricated vertical drains, with a linearly distributed (trapezoidal) vacuum pressure for both axisymmetric and plane strain conditions. The effects of the magnitude and distribution of vacuum pressure on soft clay consolidation are examined through average time-dependent excess pore pressure and consolidation settlement analyses. The plane strain analysis was executed by transforming the actual vertical drains into a system of equivalent parallel drain walls by adjusting the coefficient of permeability of the soil and the applied vacuum pressure. The converted parameters are incorporated in the finite element code ABAQUS, employing the modified Cam-clay theory. Numerical analysis conducted to study the performance of a full-scale test embankment constructed on soft Bangkok clay. The performance of this selected embankment is predicted on the basis of four different vacuum pressure distributions. The predictions are compared with the available field data. The assumption of distributing the vacuum pressure as a constant over the soil surface and varying it linearly along the drains seems justified in relation to the field data. © ASCE.
Indraratna, B, Welideniya, HS & Brown, ET 2005, 'A shear strength model for idealised infilled joints under constant normal stiffness', Géotechnique, vol. 55, no. 3, pp. 215-226.
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Infill materials found in natural rock joints may cause a reduction in joint shear strength, influencing rock mass stability. This paper reports a study aimed at developing a semi-empirical methodology for predicting the shear strength of infilled joints, taking into account joint surface characteristics and the properties of the joint and infill materials. A new model for predicting the shear strength of infilled joints is presented, on the basis of a series of tests carried out on two types of model joint surface having asperity angles of 9·5° and 18·5°, with graphite and bentonite used as infill materials. All tests were carried out in a large-scale shear apparatus under constant normal stiffness (CNS) conditions. The results indicate that at low infill thickness to asperity height ratio (t/a), the combined effect of the basic friction angle (ϕb) and the joint asperity angle (i) is pronounced, but it diminishes with increasing t/a ratio so that the shear strength converges towards that of the infill alone. Summation of two algebraic functions (A and B) that represent the joint and infill characteristics correctly models the decay of normalised shear strength with increasing t/a ratio. The new model successfully describes the observed shear strengths of the graphite and clay (bentonite) filled model joints.
Indraratna, B, Welideniya, HS & Brown, ET 2005, 'A shear strength model for idealised infilled joints under constant normal stiffness', Géotechnique, vol. 55, no. 3, pp. 215-226.
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Ji, JC & Hansen, CH 2005, 'Forced phase-locked response of a nonlinear system with time delay after Hopf bifurcation', CHAOS SOLITONS & FRACTALS, vol. 25, no. 2, pp. 461-473.
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The trivial equilibrium of a nonlinear autonomous system with time delay may become unstable via a Hopf bifurcation of multiplicity two, as the time delay reaches a critical value. This loss of stability of the equilibrium is associated with two coincident pairs of complex conjugate eigenvalues crossing the imaginary axis. The resultant dynamic behaviour of the corresponding nonlinear non-autonomous system in the neighbourhood of the Hopf bifurcation is investigated based on the reduction of the infinite-dimensional problem to a four-dimensional centre manifold. As a result of the interaction between the Hopf bifurcating periodic solutions and the external periodic excitation, a primary resonance can occur in the forced response of the system when the forcing frequency is close to the Hopf bifurcating periodic frequency. The method of multiple scales is used to obtain four first-order ordinary differential equations that determine the amplitudes and phases of the phase-locked periodic solutions. The first-order approximations of the periodic solutions are found to be in excellent agreement with those obtained by direct numerical integration of the delay-differential equation. It is also found that the steady state solutions of the nonlinear non-autonomous system may lose their stability via either a pitchfork or Hopf bifurcation. It is shown that the primary resonance response may exhibit symmetric and asymmetric phase-locked periodic motions, quasi-periodic motions, chaotic motions, and coexistence of two stable motions. © 2005 Elsevier Ltd. All rights reserved.
Ji, JC & Hansen, CH 2005, 'Hopf bifurcation of a magnetic bearing system with time delay', JOURNAL OF VIBRATION AND ACOUSTICS-TRANSACTIONS OF THE ASME, vol. 127, no. 4, pp. 362-369.
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This paper is concerned with a study of the influence of a time delay occurring in a PD feedback control on the dynamic stability of a rotor suspended by magnetic bearings. In the presence of geometric coordinate coupling and time delay, the equations of motion governing the response of the rotor are a set of two-degree-of-freedom nonlinear differential equations with time delay coupling in nonlinear terms. It is found that as the time delay increases beyond a critical value, the equilibrium position of the rotor motion becomes unstable and may bifurcate into two qualitatively different kinds of periodic motion. The resultant Hopf bifurcation is associated with two coincident pairs of complex conjugate eigenvalues crossing the imaginary axis. Based on the reduction of the infinite dimensional problem to the flow on a four-dimensional center manifold, the bifurcating periodic solutions are investigated using a perturbation method. Copyright © 2005 by ASME.
Ji, JC & Hansen, CH 2005, 'On the approximate solution of a piecewise nonlinear oscillator under super-harmonic resonance', JOURNAL OF SOUND AND VIBRATION, vol. 283, no. 1-2, pp. 467-474.
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An approximate solution for the super-harmonic resonance response of a periodically excited nonlinear oscillator with a piecewise nonlinear-linear characteristic is constructed using both a matching method and a modified averaging method. The validity of the developed analysis is confirmed by comparing the approximate solutions with the results of direct numerical integration of the original equation. © 2004 Elsevier Ltd. All rights reserved.
Ji, JC, Hansen, CH & Li, XY 2005, 'Effect of external excitations on a nonlinear system with time delay', NONLINEAR DYNAMICS, vol. 41, no. 4, pp. 385-402.
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The trivial equilibrium of a two-degree-of-freedom autonomous system may become unstable via a Hopf bifurcation of multiplicity two and give rise to oscillatory bifurcating solutions, due to presence of a time delay in the linear and nonlinear terms. The effect of external excitations on the dynamic behaviour of the corresponding non-autonomous system, after the Hopf bifurcation, is investigated based on the behaviour of solutions to the four-dimensional system of ordinary differential equations. The interaction between the Hopf bifurcating solutions and the high level excitations may induce a non-resonant or secondary resonance response, depending on the ratio of the frequency of bifurcating periodic motion to the frequency of external excitation. The first-order approximate periodic solutions for the non-resonant and super-harmonic resonance response are found to be in good agreement with those obtained by direct numerical integration of the delay differential equation. It is found that the non-resonant response may be either periodic or quasi-periodic. It is shown that the super-harmonic resonance response may exhibit periodic and quasi-periodic motions as well as a co-existence of two or three stable motions. © Springer 2005.
Lipman, J, Abolhasan, M, Boustead, P & Chicharo, J 2005, 'An optimised resource aware approach to information collection in ad hoc networks', Ad Hoc Networks, vol. 3, no. 5, pp. 643-655.
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In ad hoc networks there is a need for all-to-one protocols that allow for information collection or 'sensing' of the state of an ad hoc network and the nodes that comprise it. Such protocols may be used for service discovery, auto-configuration, network management, topology discovery or reliable flooding. There is a parallel between this type of sensing in ad hoc networks and that of sensor networks. However, ad hoc networks and sensor networks differ in their application, construction, characteristics and constraints. The main priority of sensor networks is for the flow of data from sensors back to a sink, but in an ad hoc network this may be of secondary importance. Hence, protocols suitable to sensor networks are not necessarily suitable to ad hoc networks and vice versa. We propose, Resource Aware Information Collection (RAIC), a distributed two phased resource aware approach to information collection in ad hoc networks. RAIC utilises a resource aware optimised flooding mechanism to both disseminate requests and initialise a backbone of resource suitable nodes responsible for relaying replies back to the node collecting information. RAIC in the process of collecting information from all nodes in an ad hoc network is shown to consume less energy and introduce less overhead compared with Directed Diffusion and a brute force approach. Importantly, over multiple successive queries (in an energy constrained environment), the use of resource awareness allows for the load of relaying to be distributed to those nodes most suitable, thereby extending the lifetime of the network. © 2004 Elsevier B.V. All rights reserved.
Nayak, S, Parija, J, Pradhan, B, Reddy, S, Palmer, JL, Zhang, T & Bruera, E 2005, 'Perception of quality of physician communication by cancer patients before and after the implementation of a communication strategy in a regional cancer center in India', Journal of Clinical Oncology, vol. 23, no. 16_suppl, pp. 8088-8088.
Patra, B & Pradhan, B 2005, 'Design of an environmental information system for monitoring water and air quality in urban areas', Disaster Prevention and Management: An International Journal, vol. 14, no. 3, pp. 326-342.
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PurposeOver the past 50 years India has been experiencing rapid population growth, causing the migration of a large part of the population to the cities looking for livelihood. This resulted in massive increments of population in the cities that has led to the increase of pollution. Gujarat, being a highly industrialized state, is a case in point. The systems for treatment and water disposal of this state are highly challenged. The north‐western state of Gujarat has no effective systems for treatment or disposal of waste water. The purpose of this article is to address this problem, introducing a geographic information system (GIS) approach to record the characterization, analyze the needs and generate a conceptual GIS database in the state.Design/methodology/approachThis paper outlines the background, suggested methodology for the development of a GIS database pollution dependent control of water pollution in the state of Gujarat in India. The present research is to install a document management system that has been developed in providing organizing chart, sorting, querying and retrieving of key data. A computerized laboratory information system on monitoring of quality of ambient air has been developed.FindingsAn integrated GIS database has been generated involving creation of pollutant contours, querying and visualizing the query output in spatial and non‐spatial form.Originality/valueThe authors have created a complete geo‐spatial database for the environmental monitoring for the whole state of Gujarat. They have dealt with nearly 36,000 different files from different sources and put them togethe...
Pradhan, B, Kumar, S, Mansor, S, Ramli, AR & Sharif, ARBM 2005, 'Light detection and ranging (LIDAR) data compression', KMITL Science and Technology Journal, vol. 5, no. 3, pp. 515-526.
Price, J & Indraratna, B 2005, 'Development of an Equivalent Homogenous Fluid Model for Pseudo-Two-Phase (Air+Water) Flow through Fractured Rock', Journal of Geotechnical and Geoenvironmental Engineering, vol. 131, no. 7, pp. 857-866.
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Sheng, D 2005, 'Numerical modelling of ground movement under covered areas', Australian Geomechanics Journal, vol. 40, no. 2, pp. 15-22.
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Rigorous design of interactive slab-ground foundation systems on expansive soils remains as a challenge for both practitioners and researchers. Attempts to solve these problems in a generalized way usually involve substantial approximations and have limited success. In this paper, a simple soil behaviour model is adapted into a new finite element formulation. The success of the approach is evaluated by comparing predicted foundation movements with those measured at the Maryland expansive soils field site. In particular, the computed vertical displacements are compared with field measurements. The numerical solutions are generally in good agreement with the observed data.
Sheng, D, Eigenbrod, KD & Wriggers, P 2005, 'Finite element analysis of pile installation using large-slip frictional contact', Computers and Geotechnics, vol. 32, no. 1, pp. 17-26.
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Wang, Y, Tan, T, Loe, K-F & Wu, J-K 2005, 'A probabilistic approach for foreground and shadow segmentation in monocular image sequences', Pattern Recognition, vol. 38, no. 11, pp. 1937-1946.
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Yang Wang, Loe, K-F, Tan, T & Jian-Kang Wu 2005, 'Spatiotemporal video segmentation based on graphical models', IEEE Transactions on Image Processing, vol. 14, no. 7, pp. 937-947.
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Zhao, J, Sheng, D & Zhou, W 2005, 'Shear banding analysis of geomaterials by strain gradient enhanced damage model', International Journal of Solids and Structures, vol. 42, no. 20, pp. 5335-5355.
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Abolhasan, M, Lipman, J & Society, IEEEC 1970, 'Efficient and highly scalable route discovey for on-demand routing protocols in ad hoc networks', LCN 2005: 30th Conference on Local Computer Networks, Proceedings, Local Computer Networks, 2005. 30th Anniversary. The IEEE Conference on, IEEE, Sydney, Australia, pp. 358-365.
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This paper presents a number of different route discovery strategies for on-demand routing protocols, which provide more control to each intermediate node make during the route discovery phase to make intelligent forwarding decisions. This is achieved through the idea of self-selection. In self-selecting route discovery each node independently makes route request (RREQ) forwarding decisions based upon a selection criterion or by satisfying certain conditions. The nodes which do not satisfy the selection criterion do not rebroadcast the routing packets. We implemented our self-selecting route discovery strategies over AODV using the GloMoSim network simulation package, and compared the performance with existing route discovery strategies used in AODV. Our simulation results show that a significant drop in the number of control packets can be achieved by giving each intermediate node more authority for self-selection during route discovery. Furthermore, a significant increase in throughput is achieved as the number nodes in the network is increased
Abolhasan, M, Wysocki, T, Lipman, J & IEEE 1970, 'Performance investigation on three-classes of MANET routing protocols', 2005 Asia-Pacific Conference on Communications (APCC), Vols 1& 2, Communications, 2005 Asia-Pacific Conference on, Communications, 2005 Asia-Pacific Conference on, Perth, WA, pp. 774-778.
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Routing in Ad hoc Networks has received significant attention with a number of different routing protocols proposed in recent years. These routing protocols may be classified into three main categories: proactive, reactive and hybrid. Prior work aimed at comparing the performance of routing protocols has mainly focused on comparing reactive and proactive protocols [6] [4] [1]. In this paper, we present a simulation study of different routing protocols from all three categories. We also explore the benefits and performance of each routing category. Further, we present a discussion of future research directions for routing in Ad hoc Networks. © 2005 IEEE.
Carter, JP, Potts, DM, Leung, CF, Indraratna, B, Mimura, M, Michalowski, RL, Kodaka, T & MILLPRESS 1970, 'Technical session 1f: Prediction and performance', Proceedings of the 16th International Conference on Soil Mechanics and Geotechnical Engineering, Vols 1-5, pp. 3165-3168.
Choi, F, Samali, B, Li, J, Brown, PW & Dackermann, U 1970, 'Investigation on the Dynamic Response of a Damaged Bridge', Proceedings of the 11th Asia-Pacific Vibration Conference, Asia Pacific Vibration Conference, Universiti Teknologi Malaysia, Langkawi, Malaysia, pp. 274-280.
Chun Ki Cheng & Blumenstein, M 1970, 'The neural-based segmentation of cursive words using enhanced heuristics', Eighth International Conference on Document Analysis and Recognition (ICDAR'05), Eighth International Conference on Document Analysis and Recognition (ICDAR'05), IEEE, pp. 650-654 Vol. 2.
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This paper presents an Enhanced Heuristic Segmenter (EHS) and an improved neural-based segmentation technique for segmenting cursive words and validating prospective segmentation points respectively. The EHS employs two new features, ligature detection and a neural assistant, to locate prospective segmentation points. The improved neural-based segmentation technique can then be used to examine the prospective segmentation points by fusion of confidence values obtained from left and centre character recognition outputs in addition to the segmentation point validation (SPY) output. The improved neural-based segmentation technique uses a recently proposed feature extraction technique (Modified Direction Feature) for representing the segmentation points and characters to enhance the overall segmentation process. The EHS and the neural-based segmentation technique have been implemented and tested on a benchmark database providing encouraging results. © 2005 IEEE.
Green, S, Blumenstein, M, Browne, M & Tomlinson, R 1970, 'The Detection and Quantification of Persons in Cluttered Beach Scenes Using Neural Network-Based Classification', Sixth International Conference on Computational Intelligence and Multimedia Applications (ICCIMA'05), Sixth International Conference on Computational Intelligence and Multimedia Applications (ICCIMA'05), IEEE, pp. 303-308.
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This paper presents an initial investigation into the detection and quantification of persons in real-world beach scenes for the automated monitoring of tourist sites. Aside from the obvious use of video and digital imagery for surveillance applications, this research focuses on the analysis of images for the purpose of predicting trends of tourist activities at beach sites in Australia. The proposed system uses image enhancement and segmentation techniques to detect objects in cluttered scenes. Following these steps, a newly proposed feature extraction technique is used to represent important information in the extracted objects for training of a neural network. The neural classifier is used to distinguish the extracted objects between "person" and "non-person" categories to assist in quantification. Encouraging results are presented for person classification on a database of real-word beach scenes. © 2005 IEEE.
Indraratna, B, Rujikiatkamjorn, C & Sathananthan, I 1970, 'Analytical modeling and field assessment of embankment stabilized with vertical drains and vacuum preloading', Proceedings of the 16th International Conference on Soil Mechanics and Geotechnical Engineering: Geotechnology in Harmony with the Global Environment, 16th International Conference on Soil Mechanics and Geotechnical Engineering, MILLPRESS SCIENCE PUBLISHERS, Osaka, JAPAN, pp. 1049-1052.
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This study presents an analytical model of radial drainage with vacuum preloading using compressibility indices and varying horizontal permeability and considers the influence of linearly distributed vacuum pressure along the drain. An analytical solution based on the Cylindrical Cavity Expansion theory is used to evaluate the extent of the smear zone along the drain length and predict the performance of an embankment stabilized with vacuum-assisted prefabricated vertical drains at the New Bangkok International Airport (NBIA). Here, a significantly reduced height of sand surcharge could be applied because excess pore pressure was reduced by vacuum preloading. The performance of the embankment was evaluated under different vacuum pressure conditions during which the suction head could not be maintained in the field due to probable air leaks. In the analysis, therefore, the magnitude of applied vacuum pressure was based on field measurements and adjusted accordingly. The settlement predictions based on the writers' solutions were compared and agreed with the available field data. The results also indicate that the efficiency of the vertical drains depends on the extent of the smear zone, the magnitude and distribution of vacuum pressure and the extent of air leak protection provided in the field.
Indraratna, B, Shahin, MA, Rujikiatkamjorn, C & Khabbaz, H 1970, 'Tsunami affected coastal soil disturbance and implications on reconstruction with special reference to low-cost dwellings and rail tracks', Geotechnical Engineering for Disaster Mitigation and Rehabilitation, International Conference on Geotechnical Engineering for Disaster Mitigation and Rehabilitation, WORLD SCIENTIFIC PUBL CO PTE LTD, Singapore, SINGAPORE, pp. 64-77.
Kwok, N, Ha, QP, Li, J & Samali, B 1970, 'Parameter Identification for a Magnetorheological Fluid Damper: An Evolutionary Computation Approach', Proceedings of the 6th International Symposium on Intelligent Technologies, International Symposium on Intelligent Technologies in Tech'05, Faculty of Science and Technology, Assumption University, Phuket, Thailand, pp. 115-122.
Li, J, Samali, B & Smith, ST 1970, 'Stiffness estimation and damage detection of fibre reinforced polymer strengthened reinforced concrete beams using a vibration-based method', 4th Australasian Congress on Applied Mechanics, ACAM 2005, Australasian Congress on Applied Mechanics, Institute of Materials Engineering Australasia Ltd, Melbourne, Australia, pp. 663-669.
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Reinforced concrete (RC) structural elements can be strengthened by bonding high-strength, noncorrosive fibre reinforced polymer (FRP) composites to their surfaces. In the majority of strengthening situations the existing structure would have been subjected to extreme loading at some stage of its life. It is of great interest to designers and users of structures to be aware of the condition of the structural elements, particularly with regards to damage, prior to the design and application of FRP strengthening measures. This paper reports the results of a vibration-based method for assessing damage in RC beams prior to and after the application of FRP strengthening. The vibration-based method measures the vibrations of beams with and without additional mass and provides an assessment of the degree of damage as well as stiffness of the structural element. A simply supported RC beam was constructed and initially damaged by loading to 50% of its flexural capacity. FRP strengthening was then applied and the beam tested to failure. Vibration measurements were taken prior to and after damage of the plain beam as well as after application of the FRP strengthening. The proposed method was used for detecting damage and evaluating the repair as well as quantitatively estimating in-service stiffness of the beams. Good correlation between dynamic results and static load test results is found, thus demonstrating the potential of the vibration-based method. © Institute of Materials Engineering Australasia Ltd 2005.
Martin, P, Blumenstein, M & Deer, P 1970, 'Toward Cooperatively-Built Knowledge Repositories', Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics), Springer Berlin Heidelberg, pp. 411-424.
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After noting that informal documents and formal knowledge bases are far from ideal for discussing or retrieving technical knowledge, we propose mechanisms to support the sharing, re-use and cooperative update of semi-formal semantic networks, assign values to contributions and credits to the contributors. We then propose ontological elements to guide and normalize the construction of such knowledge repositories, and an approach to permit the comparison of tools or techniques. © Springer-Verlag Berlin Heidelberg 2005.
Navak, S, Parija, J, Pradhan, B, Reddy, S, Palmer, JL, Zhang, T & Bruera, E 1970, 'Perception of quality of physician communication by cancer patients before and after the implementation of a communication strategy in a regional cancer center in India', JOURNAL OF CLINICAL ONCOLOGY, 41st Annual Meeting of the American-Society-of-Clinical-Oncology, AMER SOC CLINICAL ONCOLOGY, Orlando, FL, pp. 751S-751S.
Pradhan, B, Mansor, S, Ramli, AR, Mohamed Sharif, ARB & Sandeep, K 1970, 'LIDAR data compression using wavelets', SPIE Proceedings, Remote Sensing, SPIE, pp. 598305-598305.
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Samali, B, Dowling, DM & Li, J 1970, 'Dynamic Response of U-Shaped Adobe-Mudbrick Wall Units', Australian Structural Engineering Conference 2005: Structural Engineering - Preserving and Building into the Future, Australian Structural Engineering Conference, Tour Hosts Pty Limited, Newcastle, Australia, pp. 1-9.
Samali, B, Dowling, DM & Li, J 1970, 'Dynamic Testing of Unreinforced U-Shaped Adobe-Mudbrick Wall Unit', Developments in Mechanics of Structures and Materials, Australasian Conference on the Mechanics of Structures and Materials, A A Balkema, Perth, Australia, pp. 505-510.
Samali, B, Widjaja, JH, Li, J & Reizes, J 1970, 'Smart Braced Frame Systems', Developments in Mechanics of Structures and Materials, Australasian Conference on the Mechanics of Structures and Materials, A. A. Balkema, Perth, Australia, pp. 401-406.
Samali, B, Widjaja, JH, Li, J, Dackermann, U & Brown, PW 1970, 'Amplitude Frequency Characteristics of 'Smart'-Pin Frame System', Proceedings of the 11th Asia Pacific Vibration Conference, Asia Pacific Vibration Conference, Universiti Teknologi Malaysia, Langkawi, Malaysia, pp. 228-233.
Widjaja, J, Samali, B, Li, J & Reizes, J 1970, 'Dynamic frequency de-tuning using controllable beamcolumn semi-rigid connections', 4th Australasian Congress on Applied Mechanics, ACAM 2005, Australasian Congress on Applied Mechanics, Institute of Materials Engineering Australasia Ltd, Melbourne, Australia, pp. 807-813.
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The concept of frequency de-tuning and damping enhancement to avoid resonant frequencies and to suppress the vibration response of structures, respectively, has been known for passive vibration control systems since mid 1950's. Ideally the concept shifts the structural frequency away from resonant frequency and significantly reduces the structural response in the 'narrow-band' dampingcontrolled region. However in reality, the passive vibration control performance depends heavily on the dynamic characteristics of energy dissipation systems that are fixed and only applicable for a particular frequency band. Conversely, the Direct Current (DC) controllable beam-column semirigid connections using Magneto-rheological (MR) rotational fluid dampers, can act as real time adjustable passive control devices for any required frequency band. The supplied DC current level can adjust the device torque and rotational velocity characteristics that affect the structural frequency. This paper presents a preliminary parametric study on vibration control performance of a single and a two storey prototype plane frame model due to combination of frequency de-tuning and its associated damping enhancement by selecting end beam connections as either hinged or fixed. The controllable semi-rigid connection characteristics are represented in terms of normalised frequency. And the control performance indicated by Amplitude Frequency Characteristics (AFC) of the models is studied numerically and presented graphically. The study yields an insight into the controllable connections prior to any experiments. © Institute of Materials Engineering Australasia Ltd 2005.
Widjaja, JH, Samali, B, Li, J & Reizes, J 1970, 'Seismic Structural Control Investigations Using a Prototype Magnetorheological Shear Damper', Australian Structural Engineering Conference 2005: Structural Engineering - Preserving and Building into the Future, Australian Structural Engineering Conference, Tour Hosts Pty Limited, Newcastle, Australia, pp. 1-11.
Yang Wang & Qiang Ji 1970, 'A Dynamic Conditional Random Field Model for Object Segmentation in Image Sequences', 2005 IEEE Computer Society Conference on Computer Vision and Pattern Recognition (CVPR'05), 2005 IEEE Computer Society Conference on Computer Vision and Pattern Recognition (CVPR'05), IEEE, San Diego, CA, pp. 264-270.
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Yang Wang, Kia-Fock Loe, Tele Tan & Jian-Kang Wu 1970, 'A Dynamic Hidden Markov Random Field Model for Foreground and Shadow Segmentation', 2005 Seventh IEEE Workshops on Applications of Computer Vision (WACV/MOTION'05) - Volume 1, 2005 Seventh IEEE Workshops on Applications of Computer Vision (WACV/MOTION'05), IEEE, pp. 474-480.
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