The present study examines the validity, reliability, and psychometric properties of a newly developed violence risk assessment and treatment planning measure for youth the Violence Risk Scale-Youth Version (VRS-YV; Lewis, Wong, & Gordon, 2004). Composed of 4 static and 19 dynamic items, the VRS-YV is designed to assess violence risk, identify targets for treatment, and evaluate changes in risk as a function of treatment. Change is evaluated through a modified application of Prochaska et al.s (1992) Transtheoretical Model of Change. Stages of change ratings made pre- and post-treatment are summed across dynamic items to yield change scores. <p>The VRS-YV, Youth Level of Services/Case Management Inventory (YLS/CMI; Hoge & Andrews, 2003), and Psychopathy Checklist-Youth Version (PCL-YV; Forth, Kosson, & Hare, 2003) were each rated from file information on a sample of 133 young offenders (68 males and 65 females) who had received assessment and/or treatment services from a community mental health facility in Saskatoon, Saskatchewan. All youths had been charged or convicted of a violent offense. This tended to be a rather high risk sample with a large proportion of Aboriginal youths.<p>The VRS-YV demonstrated good internal consistency (VRS-YV total á = .91) and interrater reliability (VRS-YV total ICC = .90), while most of the individual items had acceptable inter-item (mean r = .32) and item total correlations (range r = .30 to .70). Male and female youths displayed few differences on the three risk measures or their respective scale components; however, Aboriginal youths scored significantly higher on these measures than non-Aboriginal youths, with the trend being particularly strong among males.<p>The VRS-YV showed good convergence with the YLS/CMI and PCL-YV. The three measures significantly postdicted violent offending, that is, youth who were repeat violent offenders tended to score significantly higher on each of the measures, than first time violent youth (i.e., those who had no previous history of violence). Similar postdiction was observed for general criminal offending. <p>Recidivism data were available for roughly half of the total sample (n = 62) over a mean follow-up time of approximately 2 years. Preliminary evidence was obtained for the predictive accuracy of the VRS-YV with respect to violent and general recidivism. Predictive accuracy statistics were comparable to those obtained for the YLS/CMI and PCL-YV, with correlations generally being in the .40 to .50 range and Areas Under the Curve (AUCs) in the mid .70s to low .80s. There was also a significant relationship between VRS-YV risk level and both violent and general recidivism. Survival analyses further confirmed that the VRS-YV was able to differentiate those who were more likely to recidivate and more likely to do so more quickly.<p>Change ratings were available for a small subsample of youth (n = 39), which were used to compute post-treatment dynamic ratings. Youths appeared to demonstrate some degree of change, indicating possible therapeutic progress after receiving treatment services. While the trends for the change results tended to be in the expected direction across several of the analyses, the small nature of the sample precluded meaningful interpretation of these findings.<p>In sum, these data provide preliminary evidence for the ability of the VRS-YV to evaluate risk and predict violent and general recidivism with comparable accuracy to that of two well-known and psychometrically robust instruments in the field. The results further demonstrate that the VRS-YV, YLS/CMI, and PCL-YV can have predictive validity for future violent and general recidivism among a diverse sample of youth that includes both male and female, Aboriginal, and community-based youth, living in the province of Saskatchewan. Limitations and future directions are discussed.

In this thesis, topics in chemical hazard and risk assessment are explored through the use of multimedia mass balance models and high-throughput chemical property prediction methods. Chemical hazard metrics, as calculated by environmental fate and transport simulations, are investigated to determine the validity of two common simplifying assumptions in the underlying models; the use of octanol as a surrogate for organic matter and the use of environmental parameters that do not vary in time. A major finding is that the use of these common simplifying assumptions in multimedia mass balance models has little effect on chemical risk assessment, provided that chemicals are ranked relative to each other rather than a predetermined cutoff value. Chemical properties relevant to hazard and risk are collected, and applied in a large-scale chemical hazard assessment to derive a short list of potential Arctic contaminants. Several further data needs are identified; these are widely applicable and easily calculable metrics for chemical biodegradation, toxicity and emissions. A new method of predicting chemical properties is presented to assist in meeting these data needs. The method automatically creates predictive, quantitative relationships between the structures and properties of chemicals that are comparable to similar relationships created with expert judgement.

In this thesis, topics in chemical hazard and risk assessment are explored through the use of multimedia mass balance models and high-throughput chemical property prediction methods. Chemical hazard metrics, as calculated by environmental fate and transport simulations, are investigated to determine the validity of two common simplifying assumptions in the underlying models; the use of octanol as a surrogate for organic matter and the use of environmental parameters that do not vary in time. A major finding is that the use of these common simplifying assumptions in multimedia mass balance models has little effect on chemical risk assessment, provided that chemicals are ranked relative to each other rather than a predetermined cutoff value. Chemical properties relevant to hazard and risk are collected, and applied in a large-scale chemical hazard assessment to derive a short list of potential Arctic contaminants. Several further data needs are identified; these are widely applicable and easily calculable metrics for chemical biodegradation, toxicity and emissions. A new method of predicting chemical properties is presented to assist in meeting these data needs. The method automatically creates predictive, quantitative relationships between the structures and properties of chemicals that are comparable to similar relationships created with expert judgement.

The present study examines the validity, reliability, and psychometric properties of a newly developed violence risk assessment and treatment planning measure for youth the Violence Risk Scale-Youth Version (VRS-YV; Lewis, Wong, & Gordon, 2004). Composed of 4 static and 19 dynamic items, the VRS-YV is designed to assess violence risk, identify targets for treatment, and evaluate changes in risk as a function of treatment. Change is evaluated through a modified application of Prochaska et al.s (1992) Transtheoretical Model of Change. Stages of change ratings made pre- and post-treatment are summed across dynamic items to yield change scores. <p>The VRS-YV, Youth Level of Services/Case Management Inventory (YLS/CMI; Hoge & Andrews, 2003), and Psychopathy Checklist-Youth Version (PCL-YV; Forth, Kosson, & Hare, 2003) were each rated from file information on a sample of 133 young offenders (68 males and 65 females) who had received assessment and/or treatment services from a community mental health facility in Saskatoon, Saskatchewan. All youths had been charged or convicted of a violent offense. This tended to be a rather high risk sample with a large proportion of Aboriginal youths.<p>The VRS-YV demonstrated good internal consistency (VRS-YV total á = .91) and interrater reliability (VRS-YV total ICC = .90), while most of the individual items had acceptable inter-item (mean r = .32) and item total correlations (range r = .30 to .70). Male and female youths displayed few differences on the three risk measures or their respective scale components; however, Aboriginal youths scored significantly higher on these measures than non-Aboriginal youths, with the trend being particularly strong among males.<p>The VRS-YV showed good convergence with the YLS/CMI and PCL-YV. The three measures significantly postdicted violent offending, that is, youth who were repeat violent offenders tended to score significantly higher on each of the measures, than first time violent youth (i.e., those who had no previous history of violence). Similar postdiction was observed for general criminal offending. <p>Recidivism data were available for roughly half of the total sample (n = 62) over a mean follow-up time of approximately 2 years. Preliminary evidence was obtained for the predictive accuracy of the VRS-YV with respect to violent and general recidivism. Predictive accuracy statistics were comparable to those obtained for the YLS/CMI and PCL-YV, with correlations generally being in the .40 to .50 range and Areas Under the Curve (AUCs) in the mid .70s to low .80s. There was also a significant relationship between VRS-YV risk level and both violent and general recidivism. Survival analyses further confirmed that the VRS-YV was able to differentiate those who were more likely to recidivate and more likely to do so more quickly.<p>Change ratings were available for a small subsample of youth (n = 39), which were used to compute post-treatment dynamic ratings. Youths appeared to demonstrate some degree of change, indicating possible therapeutic progress after receiving treatment services. While the trends for the change results tended to be in the expected direction across several of the analyses, the small nature of the sample precluded meaningful interpretation of these findings.<p>In sum, these data provide preliminary evidence for the ability of the VRS-YV to evaluate risk and predict violent and general recidivism with comparable accuracy to that of two well-known and psychometrically robust instruments in the field. The results further demonstrate that the VRS-YV, YLS/CMI, and PCL-YV can have predictive validity for future violent and general recidivism among a diverse sample of youth that includes both male and female, Aboriginal, and community-based youth, living in the province of Saskatchewan. Limitations and future directions are discussed.

In oil/gas and chemical industries, dynamics is one of the most essential characteristics of any process. Time-dependent response is involved in most steps of both the physical/engineering processes and the equipment performance. The conventional Quantitative Risk Assessment (QRA) is unable to address the time dependent effect in such dynamic processes. In this dissertation, a methodology of Dynamic Operational Risk Assessment (DORA) is developed for operational risk analysis in oil/gas and chemical industries. Given the assumption that the component performance state determines the value of parameters in process dynamics equations, the DORA probabilistic modeling integrates stochastic modeling and process dynamics modeling to evaluate operational risk. The stochastic system-state trajectory is modeled based on the abnormal behavior or failure of the components. For each of the possible system-state trajectories, a process dynamics evaluation is carried out to check whether process variables, e.g., level, flow rate, temperature, pressure, or chemical concentration, remain in their desirable regions. Monte Carlo simulations are performed to calculate the probability of process variable exceeding the safety boundaries. Component testing/inspection intervals and repair time are critical parameters to define the system-state configuration; and play an important role for evaluating the probability of operational failure. Sensitivity analysis is suggested to assist selecting the DORA probabilistic modeling inputs. In this study, probabilistic approach to characterize uncertainty associated with QRA is proposed to analyze data and experiment results in order to enhance the understanding of uncertainty and improve the accuracy of the risk estimation. Different scenarios on an oil/gas separation system were used to demonstrate the application of DORA method, and approaches are proposed for sensitivity and uncertainty analysis. Case study on a knockout drum in the distillation unit of a refinery process shows that the epistemic uncertainty associated with the risk estimation is reduced through Bayesian updating of the generic reliability information using plant specific real time testing or reliability data. Case study on an oil/gas separator component inspection interval optimization illustrates the cost benefit analysis in DORA framework and how DORA probabilistic modeling can be used as a tool for decision making. DORA not only provides a framework to evaluate the dynamic operational risk in oil/gas and chemical industries, but also guides the process design and optimization of the critical parameters such as component inspection intervals.

¡@¡@Recently due to the significant economic growth in Taiwan, buildings were constructed taller with usage diversified. However, the Building Code is difficult to cope with this rapid change and also sometimes with design negligence, fire accidents are not uncommon in this country. ¡@¡@Based on former experience, casualties occurred mainly due to the smoke hazard and inadequate time for egress. Therefore, quantitative assessment on these two items has become increasingly important, which is the main theme of this study. ¡@¡@During the design stage, a lot of constraints existed in adapting the local fire code, which is prescriptive in nature, especially in designing buildings with large spaces, atria, or malls. In that case, performance-based design was often attempted followed by quantitative risk assessment to validate its design effectiveness. ¡@¡@In this study, the ABRI Manual for Fire Risk assessment has been applied, followed by the F method for comparative study. The result indicated that both methods can be applied as reliable tools for fire risk assessment and warrants its application in engineering projects.

Due to the economic booms in Taiwan, huge buildings were constructed frequently and with more versatility in use. Which makes the fire protection and egress becoming a more important issue. In evaluating the smoke management and egress effectiveness, the method published by the Ministry of the Interior (MOI), or named as Route B, was widely adapted in Taiwan. However, when using this method in evaluating rooms with less than 200 square meters, difficulty existed due to the lower ceiling height and fixed internal heat released rate. It is the goal of this research to analyze the feasibility in adapting a ¡§Simplified Zone Model¡¨ for this purposes. In this research, various mathematical models were analyzed and compared first, followed by quantitative comparison with smoke descending rates calculated by both methods. It is concluded that the Simplified Zone model is suitable for evaluating rooms with floor area less than 200 square meters. Otherwise, the Route B method as proposed by the MOI is appropriate as expected.

Physical security systems are intended to prevent or mitigate potentially catastrophic loss of property or life. Decisions regarding the selection of one system or configuration of resources over another may be viewed as design decisions within a risk theoretic setting. The problem of revealing a clear preference among design alternatives, using only a partial or inexact delineation of event probabilities, is examined. In this dissertation, an analytical framework for the assessment of the risk associated with a physical security system is presented. Linear programming is used to determine bounds on the expected utility of an alternative, and conditions for the separation of preferences among alternatives are shown. If distinguishable preferences do not exist, techniques to determine what information may help to separate preferences are presented. The linear programming approach leads to identification of vulnerabilities in a security system through an examination of the solution to the dual problem. Security of a hypothetical military forward operating base is considered as an illustrative example. For two alternative security schemes, the uncertainty inherent in the scenario is represented using probability assessments consisting of bounds on event probabilities and exact probability assignments. Application of the framework reveals no separation of preferences between the alternatives. Examination of the primal and dual solutions to the linear programming problems, however, reveals insights into information which, if obtained, could lead to a separation of preferences as well as information on vulnerabilities in one of the alternative security postures.

Thesis (M. Sc.)--University of Alberta, 2009. / Title from PDF file main screen (viewed on Nov. 27, 2009). "A thesis submitted to the Faculty of Graduate Studies and Research in partial fulfillment of the requirements for the degree of Master of Science in Engineering Management, Department of Mechanical Engineering, University of Alberta." Includes bibliographical references.

Thesis (M.S.)--West Virginia University, 2004. / Title from document title page. Document formatted into pages; contains xiv, 97 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 93-97).