The Experts below are selected from a list of 498693 Experts worldwide ranked by ideXlab platform
Tarek Sayed - One of the best experts on this subject based on the ideXlab platform.
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Development of a Road Safety Risk Index
Transportation Research Record: Journal of the Transportation Research Board, 2002Co-Authors: Paul De Leur, Tarek SayedAbstract:The cornerstone of most safety management programs consists of a “collision-prone location” program, where significant collision history must exist and be identified before improvements are recommended. Often, these programs are solely dependent on collision records and thus program success is governed by the data quality. Unfortunately, in many jurisdictions in North America, the quantity and quality of collision data have been degrading for several years. This growing problem is jeopardizing the success and continuance of many road safety programs. To help mitigate this problem, it is believed that a subjective evaluation technique could be developed that does not rely on collision statistics and that could be used to identify and diagnose problematic areas. The development and application of a Risk Index used for road safety evaluation are described. The Risk Index is developed as a driver-based, subjective assessment of the potential road safety Risks for in-service roadways. The objective of developing the safety Risk Index is to produce a technique to support road safety analysis that does not rely on deteriorating collision data. The road safety Risk Index was developed and tested to ensure consistency between observers in their subjective assessment of safety. In addition, the results from the Risk Index were compared with results from objectively derived road safety measures to evaluate the success of the road safety Risk Index. The comparison indicates that there is a statistically significant agreement between the results of the Risk Index and the objectively derived road safety measures.
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Development of a Road Safety Risk Index
Transportation Research Record, 2002Co-Authors: Paul De Leur, Tarek SayedAbstract:The cornerstone of most safety management programs consists of a "collision-prone location" program, where significant collision history must exist and be identified before improvements are recommended. Often, these programs are solely dependent on collision records and thus program success is governed by the data quality. Unfortunately, in many jurisdictions in North America, the quantity and quality of collision data have been degrading for several years. This growing problem is jeopardizing the success and continuance of many road safety programs. To help mitigate this problem, it is believed that a subjective evaluation technique could be developed that does not rely on collision statistics and that could be used to identify and diagnose problematic areas. The development and application of a Risk Index used for road safety evaluation are described. The Risk Index is developed as a driver-based, subjective assessment of the potential road safety Risks for in-service roadways. The objective of developi...
Xiaoxia Huang - One of the best experts on this subject based on the ideXlab platform.
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a mean Risk Index model for uncertain capital budgeting
Journal of the Operational Research Society, 2015Co-Authors: Qun Zhang, Xiaoxia Huang, Chao ZhangAbstract:This paper discusses the capital budgeting problem of projects using annual cash inflows, cash outflows and initial investment outlays given by experts’ evaluations when no historical data are available. Uncertain variables are used to describe the projects’ parameters. A profit Risk Index and a capital Risk Index are proposed, and a mean-Risk Index model is developed for optimal project selection. In addition, the deterministic forms of the model are given and a solution algorithm is provided. For the sake of illustration, a numerical example is also presented. The results of the example show that both profit Risk Index and capital Risk Index are important in investment Risk control. However, when the profit Risk control requirement is strong, the selected project portfolio may be insensitive to the capital Risk constraint; when the profit Risk control requirement is moderate, the capital Risk constraint plays an important role. The results also show the tendency that when either the tolerable profit Risk level or the tolerable capital Risk level becomes higher, the obtained expected net present value of the project portfolio becomes larger, which is in agreement with the investment rule that the higher the Risk, the higher the return.
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A Risk Index model for portfolio selection with returns subject to experts' estimations
Fuzzy Optimization and Decision Making, 2012Co-Authors: Xiaoxia HuangAbstract:Portfolio selection is concerned with selecting an optimal portfolio that can strike a balance between maximizing the return and minimizing the Risk among a large number of securities. Traditionally, security returns were regarded as random variables. However, there are cases that the predictions of security returns are given mainly based on experts' judgements and estimations rather than historical data. In this paper, we introduce a new type of variable to reflect the subjective estimations of the security returns. A Risk Index for uncertain portfolio selection is proposed and a new safe criterion for judging the portfolio investment is introduced. Based on the proposed Risk Index, a new mean-Risk Index model is developed and its crisp forms are given. In addition, to illustrate the application of the model, two numerical examples are also presented.
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A Risk Index model for multi-period uncertain portfolio selection
Information Sciences, 2012Co-Authors: Xiaoxia Huang, Lei QiaoAbstract:This paper discusses a multi-period portfolio selection problem when security returns are given by experts' evaluations. The security return rates are regarded as uncertain variables and an uncertain Risk Index adjustment model is proposed. Optimal portfolio adjustments are determined with the objective of maximizing the total incremental wealth within the constraints of controlling the cumulative Risk Index value over the investment horizon and satisfying self-financing at each period. To enable the users to solve the model problem with currently available programming tools, an equivalent of the model is provided. In addition, a method of obtaining the uncertainty distributions of the security returns is given based on experts' evaluations, and a selection example is presented.
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A Risk Index model for uncertain portfolio selection with background Risk
Computers & Operations Research, 1Co-Authors: Xiaoxia Huang, Guowei Jiang, Pankaj Gupta, Mukesh Kumar MehlawatAbstract:Abstract This study proposes a new uncertain Risk Index model with background Risk and presents its deterministic equivalents. The security returns and background asset returns are assumed as uncertain variables and estimated by experts. To discuss the influence of background Risk on investment decisions, we compare the proposed model with a variant without background Risk and find that the portfolio with background Risk produces an equal or lower return than the one without background Risk. The effects of changes in the standard deviation of background asset and the Risk-free interest rate on optimal expected value are discussed. Two different Risk measures for portfolio optimization model with background Risk are compared, viz., the Risk Index model with background Risk is further compared with the mean chance model with background Risk. The nonlinear Risk Index model is solved by using a genetic algorithm. The efficiency of the genetic algorithm and the applications of the proposed models are illustrated through numerical experiments.
C. J. Westen - One of the best experts on this subject based on the ideXlab platform.
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Generation of a landslide Risk Index map for Cuba using spatial multi-criteria evaluation
Landslides, 2007Co-Authors: E. A. Castellanos Abella, C. J. WestenAbstract:This paper explains the procedure for the generation of a landslide Risk Index map at national level in Cuba, using a semi-quantitative model with ten indicator maps and a cell size of 90 × 90 m. The model was designed and implemented using spatial multi-criteria evaluation techniques in a GIS system. Each indicator was processed, analysed and standardised according to its contribution to hazard and vulnerability. The indicators were weighted using direct, pairwise comparison and rank-ordering weighting methods, and weights were combined to obtain the final landslide Risk Index map. The results were analysed per physiographic region and administrative units at provincial and municipal levels. The Sierra Maestra mountain system was found to have the largest concentration of high landslide Risk Index values while the Nipe–Cristal–Baracoa system has the highest absolute values, although they are more dispersed. The results obtained allow designing an appropriated landslide Risk mitigation plan at national level and to link the information to the national hurricane early warning system, allowing also warning and evacuation for landslide-prone areas.
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Generation of a landslide Risk Index map for Cuba using spatial multi-criteria evaluation
Landslides, 2007Co-Authors: E. A. Castellanos Abella, C. J. WestenAbstract:This paper explains the procedure for the generation of a landslide Risk Index map at national level in Cuba, using a semi-quantitative model with ten indicator maps and a cell size of 90 × 90 m. The model was designed and implemented using spatial multi-criteria evaluation techniques in a GIS system. Each indicator was processed, analysed and standardised according to its contribution to hazard and vulnerability. The indicators were weighted using direct, pairwise comparison and rank-ordering weighting methods, and weights were combined to obtain the final landslide Risk Index map. The results were analysed per physiographic region and administrative units at provincial and municipal levels. The Sierra Maestra mountain system was found to have the largest concentration of high landslide Risk Index values while the Nipe–Cristal–Baracoa system has the highest absolute values, although they are more dispersed. The results obtained allow designing an appropriated landslide Risk mitigation plan at national level and to link the information to the national hurricane early warning system, allowing also warning and evacuation for landslide-prone areas.
David A. Lombardi - One of the best experts on this subject based on the ideXlab platform.
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Toward a “Risk Index” to Assess Work Schedules
Chronobiology international, 2004Co-Authors: Simon Folkard, David A. LombardiAbstract:This article describes our preliminary attempt to develop a Risk Index to estimate the Risk of human error on different work schedules based on trends in the relative Risk of accidents and injuries, rather than on hypothetical intervening variables such as alertness, fatigue, or performance on interpolated tasks. We briefly review trends in Risk from the published epidemiological studies that have ensured that the a priori Risk was constant. A simple Risk Index based on an additive model is developed on the basis of these trends, and we illustrate how it may be used to assess work schedules. Finally, we compare the results from this Risk Index with those from the UK HSE's Fatigue Index and point out the discrepancies that emerge. We conclude that our Risk-based modeling approach may assist in developing safer work schedules and also increase our understanding of this complex, multifaceted area.
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toward a Risk Index to assess work schedules
Chronobiology International, 2004Co-Authors: Simon Folkard, David A. LombardiAbstract:This article describes our preliminary attempt to develop a Risk Index to estimate the Risk of human error on different work schedules based on trends in the relative Risk of accidents and injuries, rather than on hypothetical intervening variables such as alertness, fatigue, or performance on interpolated tasks. We briefly review trends in Risk from the published epidemiological studies that have ensured that the a priori Risk was constant. A simple Risk Index based on an additive model is developed on the basis of these trends, and we illustrate how it may be used to assess work schedules. Finally, we compare the results from this Risk Index with those from the UK HSE's Fatigue Index and point out the discrepancies that emerge. We conclude that our Risk-based modeling approach may assist in developing safer work schedules and also increase our understanding of this complex, multifaceted area.
Paul De Leur - One of the best experts on this subject based on the ideXlab platform.
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Development of a Road Safety Risk Index
Transportation Research Record: Journal of the Transportation Research Board, 2002Co-Authors: Paul De Leur, Tarek SayedAbstract:The cornerstone of most safety management programs consists of a “collision-prone location” program, where significant collision history must exist and be identified before improvements are recommended. Often, these programs are solely dependent on collision records and thus program success is governed by the data quality. Unfortunately, in many jurisdictions in North America, the quantity and quality of collision data have been degrading for several years. This growing problem is jeopardizing the success and continuance of many road safety programs. To help mitigate this problem, it is believed that a subjective evaluation technique could be developed that does not rely on collision statistics and that could be used to identify and diagnose problematic areas. The development and application of a Risk Index used for road safety evaluation are described. The Risk Index is developed as a driver-based, subjective assessment of the potential road safety Risks for in-service roadways. The objective of developing the safety Risk Index is to produce a technique to support road safety analysis that does not rely on deteriorating collision data. The road safety Risk Index was developed and tested to ensure consistency between observers in their subjective assessment of safety. In addition, the results from the Risk Index were compared with results from objectively derived road safety measures to evaluate the success of the road safety Risk Index. The comparison indicates that there is a statistically significant agreement between the results of the Risk Index and the objectively derived road safety measures.
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Development of a Road Safety Risk Index
Transportation Research Record, 2002Co-Authors: Paul De Leur, Tarek SayedAbstract:The cornerstone of most safety management programs consists of a "collision-prone location" program, where significant collision history must exist and be identified before improvements are recommended. Often, these programs are solely dependent on collision records and thus program success is governed by the data quality. Unfortunately, in many jurisdictions in North America, the quantity and quality of collision data have been degrading for several years. This growing problem is jeopardizing the success and continuance of many road safety programs. To help mitigate this problem, it is believed that a subjective evaluation technique could be developed that does not rely on collision statistics and that could be used to identify and diagnose problematic areas. The development and application of a Risk Index used for road safety evaluation are described. The Risk Index is developed as a driver-based, subjective assessment of the potential road safety Risks for in-service roadways. The objective of developi...
