900 resultados para Parametric VaR (Value-at-Risk)


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This report presents the results of research projects conducted by The Australian Cooperative Research Centre for Construction Innovation, Queensland University of Technology, RMIT University, Queensland Government Department of Main Roads and Queensland Department of Public Works. The research projects aimed at developing a methodology for assessing variation and risk in investment in road network, including the application of the method in assessing road network performance and maintenance and rehabilitation costs for short- and long-term future investment.

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Realistic estimates of short- and long-term (strategic) budgets for maintenance and rehabilitation of road assessment management should consider the stochastic characteristics of asset conditions of the road networks so that the overall variability of road asset data conditions is taken into account. The probability theory has been used for assessing life-cycle costs for bridge infrastructures by Kong and Frangopol (2003), Zayed et.al. (2002), Kong and Frangopol (2003), Liu and Frangopol (2004), Noortwijk and Frangopol (2004), Novick (1993). Salem 2003 cited the importance of the collection and analysis of existing data on total costs for all life-cycle phases of existing infrastructure, including bridges, road etc., and the use of realistic methods for calculating the probable useful life of these infrastructures (Salem et. al. 2003). Zayed et. al. (2002) reported conflicting results in life-cycle cost analysis using deterministic and stochastic methods. Frangopol et. al. 2001 suggested that additional research was required to develop better life-cycle models and tools to quantify risks, and benefits associated with infrastructures. It is evident from the review of the literature that there is very limited information on the methodology that uses the stochastic characteristics of asset condition data for assessing budgets/costs for road maintenance and rehabilitation (Abaza 2002, Salem et. al. 2003, Zhao, et. al. 2004). Due to this limited information in the research literature, this report will describe and summarise the methodologies presented by each publication and also suggest a methodology for the current research project funded under the Cooperative Research Centre for Construction Innovation CRC CI project no 2003-029-C.

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An estimation of costs for maintenance and rehabilitation is subject to variation due to the uncertainties of input parameters. This paper presents the results of an analysis to identify input parameters that affect the prediction of variation in road deterioration. Road data obtained from 1688 km of a national highway located in the tropical northeast of Queensland in Australia were used in the analysis. Data were analysed using a probability-based method, the Monte Carlo simulation technique and HDM-4’s roughness prediction model. The results of the analysis indicated that among the input parameters the variability of pavement strength, rut depth, annual equivalent axle load and initial roughness affected the variability of the predicted roughness. The second part of the paper presents an analysis to assess the variation in cost estimates due to the variability of the overall identified critical input parameters.

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Research on social networking sites like Facebook is emerging but sparse. This exploratory study investigates the value users derive from self-described ‘cool’ Facebook applications, and explores the features that either encourage or discourage users to recommend applications to their friends. The concepts of value and cool are explored in a social networking context. Our qualitative data reveals consumers derive a combination of functional value along with either social or emotional value from the applications. Female Facebook users indicate self-expression as important motivators, while males tend to use Facebook applications to socially compete. Three broad categories emerged for application features; symmetrical features can both encourage or discourage recommendation, polar features where different levels of the same feature encourage or discourage, and uni-directional features only encourage or discourage but not both. Recommending or not recommending an application tends to be the result of a combination of features and context, rather than one feature in isolation.

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In my work with secondary school students who have disengaged from mainstream classrooms, I have often been surprised at the ways they enthusiastically engage with the projects on offer. They have demonstrated that, in apparent contradiction of their classroom behaviour, they still maintain hope in achieving a positive outcome from education. In a long-running schools-university project employing a “students-as-researchers” approach to investigating educational disadvantage, “at-risk” students have produced high quality results. Naturally, I wanted to know what it was about this sort of pedagogy that seemed to work for them. In this chapter, then, I outline the project and discuss some reasons for disengagement. I then address the features of the project that the participants themselves have identified as being instrumental in their re-engagement with formal education. Finally, I consider how these features may be transposed to maintaining the educational engagement of at-risk students in mainstream classrooms.

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Construction sector policy makers have the opportunity to create improvements and develop economic, social and environmental sustainability through supply chain economics. The idea of the supply chain concept to improve firm behaviour and industry performance is not new. However there has been limited application and little or no measurement to monitor successful implementation. Often purchasing policies have been developed with sound strategic procurement principles but even these have had limited penetration in to the processes and practices of infrastructure agencies. The research reported in this paper documents an action research study currently being undertaken in the Australian construction sector which aims to explore supply chain economic policy implementation for sectoral change by two government agencies. The theory which informs this study is the emerging area of construction supply chain economics. There are five stages to the project including; demand analysis, chain analysis, government agency organizational audit, supplier strategy and strategic alignment. The overall objective is towards the development of a Supplier Group Strategy Map for two public sector agencies. Two construction subsectors are examined in detail; construction and demolition waste and precast concrete. Both of these subsectors are critical to the economic and environmental sustainability performance of the construction sector and the community as a whole in the particular jurisdictions. The local and state government agencies who are at the core of the case studies rely individually on the performance of these sectors. The study is set within the context of a sound state purchasing policy that has however, had limited application by the two agencies. Partial results of the study are presented and early findings indicate that the standard risk versus expenditure procurement model does not capture the complexities of project, owner and government risk considerations. A new model is proposed in this paper, which incorporates the added dimension of time. The research results have numerous stakeholders; they will hold particular value for those interested in regional construction sector economics, government agencies who develop and implement policy and who have a large construction purchasing imprint and the players involved in the two subsectors. Even though this is a study in Australia it has widespread applicability as previous research indicates that procurement reform is of international significance and policy implementation is problematic.

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Queensland Department of Main Roads, Australia, spends approximately A$ 1 billion annually for road infrastructure asset management. To effectively manage road infrastructure, firstly road agencies not only need to optimise the expenditure for data collection, but at the same time, not jeopardise the reliability in using the optimised data to predict maintenance and rehabilitation costs. Secondly, road agencies need to accurately predict the deterioration rates of infrastructures to reflect local conditions so that the budget estimates could be accurately estimated. And finally, the prediction of budgets for maintenance and rehabilitation must provide a certain degree of reliability. This paper presents the results of case studies in using the probability-based method for an integrated approach (i.e. assessing optimal costs of pavement strength data collection; calibrating deterioration prediction models that suit local condition and assessing risk-adjusted budget estimates for road maintenance and rehabilitation for assessing life-cycle budget estimates). The probability concept is opening the path to having the means to predict life-cycle maintenance and rehabilitation budget estimates that have a known probability of success (e.g. produce budget estimates for a project life-cycle cost with 5% probability of exceeding). The paper also presents a conceptual decision-making framework in the form of risk mapping in which the life-cycle budget/cost investment could be considered in conjunction with social, environmental and political issues.

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A study has been conducted to investigate current practices on decision-making under risk and uncertainty for infrastructure project investments. It was found that many European countries such as the UK, France, Germany including Australia use scenarios for the investigation of the effects of risk and uncertainty of project investments. Different alternative scenarios are mostly considered during the engineering economic cost-benefit analysis stage. For instance, the World Bank requires an analysis of risks in all project appraisals. Risk in economic evaluation needs to be addressed by calculating sensitivity of the rate of return for a number of events. Risks and uncertainties of project developments arise from various sources of errors including data, model and forecasting errors. It was found that the most influential factors affecting risk and uncertainty resulted from forecasting errors. Data errors and model errors have trivial effects. It was argued by many analysts that scenarios do not forecast what will happen but scenarios indicate only what can happen from given alternatives. It was suggested that the probability distributions of end-products of the project appraisal, such as cost-benefit ratios that take forecasting errors into account, are feasible decision tools for economic evaluation. Political, social, environmental as well as economic and other related risk issues have been addressed and included in decision-making frameworks, such as in a multi-criteria decisionmaking framework. But no suggestion has been made on how to incorporate risk into the investment decision-making process.

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In line with developments overseas Australian clients are turning to considerations of value in project procurement. Until the 1980s the industry operated in a largely traditional manner however the extremely adversarial behaviour exhibited during towards the end of the decade led to a number of significant events and initiatives including the publication of “No Dispute”, the Gyles Royal Commission into the Building Industry, the Construction Industry Development Agency (CIDA) and the work of the Australian Procurement and Construction Council (APCC). A number of research projects in progress in the CRC for Construction Innovation (CRC CI) are focussing on the assessment of value and methodologies to support the delivery of value in the procurement and management of engineering and construction projects. This paper charts the emergence of several key drivers in the process and illustrates how they can be integrated into a comprehensive Decision Support System that balances value to stakeholders with project imperatives and incorporates a lessons learned data base which enriches the decision making process to optimise delivery method design and selection.

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A study into best practice project delivery and the development of a suite of products, resources and services to help guide clients and project teams towards the best approach for specific projects.

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Australian and international governments are increasingly adopting social marketing as a social change management tool to deal with complex social problems. Government decision makers typically need to balance the use of business models and management theories whilst maintaining the integrity of government policy. In taking this approach, decision makers experience management tensions between a social mission to equitably deliver social services and the accountability and affordability of providing quality social and health services to citizens. This is a significant challenge as the nature of the ‘social product’ in government is often more service-oriented than goods-based. In this paper the authors examine value creation in government social marketing services. The contribution of this paper is a value creation process model, which considers the nature of governments to create social good. This is particularly important for governments where consumers still expect value and quality in the service delivered, despite that offering being ‘free’.

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Background: Injury is the leading cause of mortality for young people in Australia (AIHW, 2008). Adolescent injury mortality is consistently associated with risk taking behaviour, including transport and interpersonal violence (AIHW, 2003), which often occurs in the context of alcohol and other substance use. A rapid increase in risk taking and injury through early to late adolescence highlights the need for effective school based interventions. Aim: The aim of the current research was to examine the relationship between school connectedness and adolescent risk and injury, in order to inform effective prevention approaches. School connectedness, or students’ feelings of belongingness to school, has been shown to be a critical protective factor in adolescence which can be targeted effectively through teacher interventions. Despite evidence linking low school connectedness with increased health risk behaviour, including substance use and violence, research has not yet addressed possible links between connectedness and a broader range of risk taking behaviours (e.g. transport risks) or injury. Method: This study involved background data collection to inform the development of an intervention. A total of 595 Year 9 students (aged 13-14 years) from 5 Southeast Queensland high schools completed questionnaires that included measures of school connectedness, risk taking behaviour, alcohol and other substance use, and injuries. Results: Increased school connectedness was found to be associated with fewer transport risk behaviours and with decreased alcohol and other substance use for both males and females. Similarly, increased school connectedness was associated with fewer passenger and motorcycle injuries for male participants. Both males and females with increased school connectedness reported fewer alcohol related injuries. Implications: These results indicate that school connectedness appears to have protective effects for early adolescence. These findings may also hold for older adolescents and indicate that it may be an important factor to target in school based risk and injury prevention programs. A school connectedness intervention is currently being designed, focusing on teacher professional development. The intervention will be implemented in conjunction with a curriculum based injury prevention program for Year 9 students and will be evaluated through a large scale cluster randomised trial involving 26 schools.