Infrastructure Engineering - Research Publications
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ItemRoad Networks Management under Uncertainty: A stochastic based model(SpringerLink, 2012)Current pavement management systems (PMS) adopted by the Road Authorities are often very complex and data intensive. Other challenges also faced by Road Authorities in managing road networks include budget constraints and the uncertainty associated in predicting the future performance of pavements. In addition, the emphasis in pavement management has shifted from reconstructing completely new roads towards preservation of existing networks. In many cases, existing PMS do not meet these requirements. Thus, an efficient model that is able to accommodate all of those challenges needs to be developed. This paper outlines the development of a stochastic based PMS that includes a performance prediction model using Markov chains and an optimization model based on Markov Decision Processes (MDP). Combinations of pavement preservation strategies and maintenance budget levels are applied as action criteria in contrast to other stochastic models. Despite the apparent influence of uncertainty in road pavement performance during their service live, stochastic models provide promising results for enhancing current PMS. By analysing historical data, the future behaviour of road pavements under different expenditure levels and combination of routine and periodic maintenance measures can be predicted. From an optimization point of view, the utilization of constrained MDP will potentially result in cost savings. This is due to the optimality principal of the model which is capable of finding a optimal multi-year maintenance policy through the direct inclusion of additional constraints into the optimization problem. Hence, the model considers constraints and incorporates relationships between historical maintenance actions and costs. This paper also presents a methodology for developing rationale for long-term maintenance policies by integrating stochastic based performance prediction and optimization models with the experience of Road Authorities in managing roads networks.
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ItemImproved capital procurement through increased use of quantitatively-based decisions(Department of Civil Engineering, National Taiwan University, 2008)The procurement of major capital projects always involves significant risk and uncertainties and this is one of the primary causes for the variations from expected outcomes. This paper outlines the delimitation between strategies for making complex decisions using quantitative analyses as opposed to the techniques and applications currently being used by project and construction managers. Various approaches have been developed and adopted by researchers and practitioners to improve the quality of critical project decisions to maximise benefits. Strategic frameworks and organisational hierarchies are frequently deemed as an optimal solution from the perspective of industrial participants, while numerous researchers indicate decisions with quantitative evidences, underpinned by proper choice of technique, will add additional benefits over current industrial practices. It is asserted that improved decisions can be made through the additional use of quantitative approaches. This paper reports the finding of a study that has identified where the increased use of quantitative approaches may assist project and construction managers and proposes a mechanism to confirm the potential benefits.
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ItemInterpretation of qualitative and quantitative information for project reviews: A fuzzy-based approach for OGC ™ gateway review (GR) colour code system (CCS)(Department of Civil Engineering, National Taiwan University, 2008)Independent project reviews are gaining popularity as a technique to improve project outcomes through the timely identification of outstanding project risks. A common technique is that of a Gateway. The Gateway Review Process (GRP) appraises qualitative and quantitative risks and reports the findings via a Colour Code System (CCS) of Red/Amber/Green (R/A/G). Medium to high risk projects that exceed certain risk thresholds are eligible for GRP. Intuitive recognition of potential risks from the application of CCS is insufficient to determine the value gained from the process. This paper attempts to shed light on a tentative effort to interpret the CCS into numerical descriptions by using fuzzy-based method on a survey outcome. This quantitative interpretation of the CCS would then be adopted to provide a measure and understanding (decision evidence) of the benefits obtained through project review such as GRP.
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ItemQuantification of the contribution of non-structural components to the structural performance of high-rise buildings(Department of Civil Engineering, National Taiwan University, 2008-12-01)Non-structural components (NSCs) such as infill walls, façades, stairs, and windows are normally considered as non-load bearing components in the design of buildings. However, a number of researchers have identified that those so-called NSCs have a significant contribution to the lateral performance of the structure. This paper presents the findings of the investigation into the influence of a variety of NSCs on the performance of typical high-rise framed structures via the observation of the influence of these NSCs on the shear and flexural performance, as well as the lateral stiffness of the structures. Finite element (FE) models have been developed to analyse storey drifts, shear force distributions, bending moment distributions, and joint rotations under different structural configurations. The results of the study indicate a significant decrease of the storey drift can be achieved by including different NSCs to the structural frame. Dramatic changes to both the bending moment and the shear force distributions in the inner columns of the structural frame are resulted from the inclusion of NSCs. However, the influence of these NSCs on the flexural and shear performance of the outer columns of the building is significantly less than that of the inner columns. It is concluded that the enhanced performance of actual buildings by including NSCs provides opportunity for refining of the lateral deflection of the building for the serviceability limit states.
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ItemInfrastructure investment decisions - issues surrounding the use of financial analysis(Nanyang University, 2001)
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ItemLessons learned in the design and construction of a wastewater earth liner project(CITC Construction in the 21st Century, 2003)
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ItemA preliminary artificial intelligence model for predicting the risk from glass windows subject to airblast overpressure(Construction Publishing House, 2007)
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ItemThe use of long term contracts to stimulate innovation and long term maintenance of Public Infrastructure(Construction Publishing House, 2007)
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ItemRacking behaviour of residential light framed walls(The Institution of Engineers, Australia, 2001)
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ItemAssessment of plasterboard properties and relationship to lateral capacity of residential structures(The Institution of Engineers, Australia, 2001)