WorldWideScience

Sample records for risk based limits

  1. Risk based limits for Operational Safety Requirements

    International Nuclear Information System (INIS)

    Cappucci, A.J. Jr.

    1993-01-01

    OSR limits are designed to protect the assumptions made in the facility safety analysis in order to preserve the safety envelope during facility operation. Normally, limits are set based on ''worst case conditions'' without regard to the likelihood (frequency) of a credible event occurring. In special cases where the accident analyses are based on ''time at risk'' arguments, it may be desirable to control the time at which the facility is at risk. A methodology has been developed to use OSR limits to control the source terms and the times these source terms would be available, thus controlling the acceptable risk to a nuclear process facility. The methodology defines a new term ''gram-days''. This term represents the area under a source term (inventory) vs time curve which represents the risk to the facility. Using the concept of gram-days (normalized to one year) allows the use of an accounting scheme to control the risk under the inventory vs time curve. The methodology results in at least three OSR limits: (1) control of the maximum inventory or source term, (2) control of the maximum gram-days for the period based on a source term weighted average, and (3) control of the maximum gram-days at the individual source term levels. Basing OSR limits on risk based safety analysis is feasible, and a basis for development of risk based limits is defensible. However, monitoring inventories and the frequencies required to maintain facility operation within the safety envelope may be complex and time consuming

  2. A risk-based microbiological criterion that uses the relative risk as the critical limit

    DEFF Research Database (Denmark)

    Andersen, Jens Kirk; Nørrung, Birgit; da Costa Alves Machado, Simone

    2015-01-01

    A risk-based microbiological criterion is described, that is based on the relative risk associated to the analytical result of a number of samples taken from a food lot. The acceptable limit is a specific level of risk and not a specific number of microorganisms, as in other microbiological...... criteria. The approach requires the availability of a quantitative microbiological risk assessment model to get risk estimates for food products from sampled food lots. By relating these food lot risk estimates to the mean risk estimate associated to a representative baseline data set, a relative risk...... estimate can be obtained. This relative risk estimate then can be compared with a critical value, defined by the criterion. This microbiological criterion based on a relative risk limit is particularly useful when quantitative enumeration data are available and when the prevalence of the microorganism...

  3. Dynamic probability control limits for risk-adjusted CUSUM charts based on multiresponses.

    Science.gov (United States)

    Zhang, Xiang; Loda, Justin B; Woodall, William H

    2017-07-20

    For a patient who has survived a surgery, there could be several levels of recovery. Thus, it is reasonable to consider more than two outcomes when monitoring surgical outcome quality. The risk-adjusted cumulative sum (CUSUM) chart based on multiresponses has been developed for monitoring a surgical process with three or more outcomes. However, there is a significant effect of varying risk distributions on the in-control performance of the chart when constant control limits are applied. To overcome this disadvantage, we apply the dynamic probability control limits to the risk-adjusted CUSUM charts for multiresponses. The simulation results demonstrate that the in-control performance of the charts with dynamic probability control limits can be controlled for different patient populations because these limits are determined for each specific sequence of patients. Thus, the use of dynamic probability control limits for risk-adjusted CUSUM charts based on multiresponses allows each chart to be designed for the corresponding patient sequence of a surgeon or a hospital and therefore does not require estimating or monitoring the patients' risk distribution. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

  4. Limit lines for risk

    International Nuclear Information System (INIS)

    Cox, D.C.; Baybutt, P.

    1982-01-01

    Approaches to the regulation of risk from technological systems, such as nuclear power plants or chemical process plants, in which potential accidents may result in a broad range of adverse consequences must take into account several different aspects of risk. These include overall or average risk, accidents posing high relative risks, the rate at which accident probability decreases with increasing accident consequences, and the impact of high frequency, low consequence accidents. A hypothetical complementary cumulative distribution function (CCDF), with appropriately chosen parametric form, meets all these requirements. The Farmer limit line, by contrast, places limits on the risks due to individual accident sequences, and cannot adequately account for overall risk. This reduces its usefulness as a regulatory tool. In practice, the CCDF is used in the Canadian nuclear licensing process, while the Farmer limit line approach, supplemented by separate qualitative limits on overall risk, is employed in the United Kingdom

  5. Calculation of risk-based detection limits for radionuclides in the liquid effluents from Korean nuclear power plants

    International Nuclear Information System (INIS)

    Cheong, Jae Hak

    2017-01-01

    In order to review if present detection limits of radionuclides in liquid effluent from nuclear power plants are effective enough to warrant compliance with regulatory discharge limits, a risk-based approach is developed to derive a new detection limit for each radionuclide based on radiological criteria. Equations and adjustment factors are also proposed to discriminate the validity of the detection limits for multiple radionuclides in the liquid effluent with or without consideration of the nuclide composition. From case studies to three nuclear power plants in Korea with actual operation data from 2006 to 2015, the present detection limits have turned out to be effective for Hanul Unit 1 but may not be sensitive enough for Kori Unit 1 (8 out of 14 radionuclides) and Wolsong Unit 1 (9 out of 42 radionuclides). However, it is shown that the present detection limits for the latter two nuclear power plants can be justified, if credit is given to the radionuclide composition. Otherwise, consideration should be given to adjustment of the present detection limits. The risk-based approach of this study can be used to determine the validity of established detection limits of a specific nuclear power plant. (author)

  6. An evaluation of a risk-based environmental regulation in Brazil: Limitations to risk management of hazardous installations

    International Nuclear Information System (INIS)

    Naime, Andre

    2017-01-01

    The environmental regulation of hazardous projects with risk-based decision-making processes can lead to a deficient management of human exposure to technological hazards. Such an approach for regulation is criticized for simplifying the complexity of decisions involving the economic, social, and environmental aspects of the installation and operation of hazardous facilities in urban areas. Results of a Brazilian case study indicate that oil and gas transmission pipelines may represent a threat to diverse communities if the relationship between such linear projects and human populations is overlooked by regulatory bodies. Results also corroborate known challenges to the implementation of EIA processes and outline limitations to an effective environmental and risk management. Two preliminary topics are discussed to strengthen similar regulatory practices. Firstly, an effective integration between social impact assessment and risk assessment in EIA processes to have a more comprehensive understanding of the social fabric. Secondly, the advancement of traditional management practices for hazardous installations to pursue a strong transition from assessment and evaluation to management and control and to promote an effective interaction between land-use planning and environmental regulation.

  7. An evaluation of a risk-based environmental regulation in Brazil: Limitations to risk management of hazardous installations

    Energy Technology Data Exchange (ETDEWEB)

    Naime, Andre, E-mail: andre.naime.ibama@gmail.com

    2017-03-15

    The environmental regulation of hazardous projects with risk-based decision-making processes can lead to a deficient management of human exposure to technological hazards. Such an approach for regulation is criticized for simplifying the complexity of decisions involving the economic, social, and environmental aspects of the installation and operation of hazardous facilities in urban areas. Results of a Brazilian case study indicate that oil and gas transmission pipelines may represent a threat to diverse communities if the relationship between such linear projects and human populations is overlooked by regulatory bodies. Results also corroborate known challenges to the implementation of EIA processes and outline limitations to an effective environmental and risk management. Two preliminary topics are discussed to strengthen similar regulatory practices. Firstly, an effective integration between social impact assessment and risk assessment in EIA processes to have a more comprehensive understanding of the social fabric. Secondly, the advancement of traditional management practices for hazardous installations to pursue a strong transition from assessment and evaluation to management and control and to promote an effective interaction between land-use planning and environmental regulation.

  8. Environmental radiation standards and risk limitation

    International Nuclear Information System (INIS)

    Kocher, D.C.

    1987-01-01

    The Environmental Protection Agency and Nuclear Regulatory Commission have established environmental radiation standards for specific practices which correspond to limits on risk to the public that vary by several orders of magnitude and often are much less than radiation risks that are essentially unregulated, e.g., risks from radon in homes. This paper discusses a proposed framework for environmental radiation standards that would improve the correspondence with limitation of risk. This framework includes the use of limits on annual effective dose equivalent averaged over a lifetime, rather than limits on dose equivalent to whole body or any organ for each year of exposure, and consideration of exposures of younger age groups as well as adults; limits on annual effective dose equivalent averaged over a lifetime no lower than 0.25 mSv (25 mrem) per practice; maintenance of all exposures as low as reasonably achievable (ALARA); and establishment of a generally applicable de minimis dose for public exposures. Implications of the proposed regulatory framework for the current system of standards for limiting public exposures are discussed. 20 refs

  9. Bases for establishing radiation exposure limits

    International Nuclear Information System (INIS)

    Pochin, E.E.

    1977-01-01

    It is an essential requirement of good radiation protection that all unnecessary exposure of people should be avoided and that any necessary exposure, whether of workers or of members of the general public, should be minimized. It is, however, an additional requirement that such necessary exposures should not exceed certain stated limits. These principles are based on the possibility that even the smallest exposures may involve some risk of harm, that any risk of harm should be justifiable by the circumstances necessitating it, and that risk should always be limited to an appropriately low level. The bases for establishing exposure limits must therefore involve an assessment of the risk involved in any form of radiation exposure, and an opinion as to the degree of safety that should be ensured in circumstances which necessitate any occupational or public exposure to radiation. There is increasing quantitative evidence on the frequency on which harm, and particularly the induction of malignancies, may be caused in people exposed to radiation at high doses; and somewhat clearer bases than previously for inferring the possible frequencies at low doses. It is therefore easier to assess the degree of safety ensured by restricting radiation exposure to particular levels. It is clear also that a comparable degree of safety should be ensured whether the radiation exposure involves the whole body more of less uniformly, or individual tissues or organs selectively. The ''weighting'' factors appropriate to irradiation of particular tissues from internal emitters can thus be defined in terms of their likely individual contributions to the harm of whole-body irradiation. In this way the limits for different modes of exposure by external or internal radiation can be related so as to ensure that protection should be equally effective for different distributions of absorbed dose in the body. In particular, the over-simplified concept of a single critical organ determining the

  10. Hanford Waste Vitrification Project Building limited scope risk assessment

    International Nuclear Information System (INIS)

    Braun, D.J.; Lindberg, S.E.; Reardon, M.F.; Wilson, G.P.

    1992-10-01

    A limited scope risk assessment was performed on the preliminary design of a high-level waste interim storage facility. The Canister Storage Building (CSB) facility will be built to support remediation at the US Department of Energy Hanford Site in Washington State. The CSB will be part of the support facilities for a high level Hanford Waste Vitrification Plant (HWVP). The limited scope risk assessment is based on a preliminary design which uses forced air circulation systems to move air through the building vault. The current building design calls for natural circulation to move air through the building vault

  11. Bases for establishing radiation exposure limits

    International Nuclear Information System (INIS)

    Pochin, E.E.

    1977-01-01

    It is an essential requirement of good radiation protection that all unnecessary exposure of people should be avoided and that any necessary exposure, whether of workers or of members of the general public, should be minimised. It is, however, an additional requirement that such necessary exposures should not exceed certain stated limits. These principles are based on the possibility that even the smallest exposures may involve some risk of harm, that any risk of harm should be justifiable by the circumstances necessitating it, and that risk should always be limited to an appropriately low level. The bases for establishing exposure limits must therefore involve an assessment of the risk involved in any form of radiation exposure, and an opinion as to the degree of safety that should be ensured in circumstances which necessitate any occupational or public exposure to radiation. There is increasing quantitative evidence on the frequency on which harm, and particularly the induction of malignancies, may be caused in people exposed to radiation at high doses; and somewhat clearer bases than previously for inferring the possible frequencies at low doses. It is therefore easier to assess the degree of safety ensured by restricting radiation exposure to particular levels. The degree of safety which should be regarded as appropriate in different circumstances remains a matter for review, but suggestions are made as to levels which would be advocated by informed opinion, and the exposure limits which would correspond to these. It is clear also that a comparable degree of safety should be ensured whether the radiation exposure involves the whole body more of less uniformly, or individual tissues or organs selectively. Increasing epidemiological evidence is available on the relative sensitivity to radiation induction of malignancies in a number of organs, and to the apparently much lower sensitivity of other organs; and experimental evidence in animals allows a comparable

  12. 46 CFR 249.8 - Limitation on risk.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 8 2010-10-01 2010-10-01 false Limitation on risk. 249.8 Section 249.8 Shipping... OPERATORS APPROVAL OF UNDERWRITERS FOR MARINE HULL INSURANCE § 249.8 Limitation on risk. (a) Underwriters may take a line on any single risk in excess of five percent of its Policyholders' Surplus only with...

  13. A qualitative risk assessment approach for Swiss dairy products: opportunities and limitations.

    Science.gov (United States)

    Menéndez González, S; Hartnack, S; Berger, T; Doherr, M; Breidenbach, E

    2011-05-01

    Switzerland implemented a risk-based monitoring of Swiss dairy products in 2002 based on a risk assessment (RA) that considered the probability of exceeding a microbiological limit value set by law. A new RA was launched in 2007 to review and further develop the previous assessment, and to make recommendations for future risk-based monitoring according to current risks. The resulting qualitative RA was designed to ascertain the risk to human health from the consumption of Swiss dairy products. The products and microbial hazards to be considered in the RA were determined based on a risk profile. The hazards included Campylobacter spp., Listeria monocytogenes, Salmonella spp., Shiga toxin-producing Escherichia coli, coagulase-positive staphylococci and Staphylococcus aureus enterotoxin. The release assessment considered the prevalence of the hazards in bulk milk samples, the influence of the process parameters on the microorganisms, and the influence of the type of dairy. The exposure assessment was linked to the production volume. An overall probability was estimated combining the probabilities of release and exposure for each combination of hazard, dairy product and type of dairy. This overall probability represents the likelihood of a product from a certain type of dairy exceeding the microbiological limit value and being passed on to the consumer. The consequences could not be fully assessed due to lack of detailed information on the number of disease cases caused by the consumption of dairy products. The results were expressed as a ranking of overall probabilities. Finally, recommendations for the design of the risk-based monitoring programme and for filling the identified data gaps were given. The aims of this work were (i) to present the qualitative RA approach for Swiss dairy products, which could be adapted to other settings and (ii) to discuss the opportunities and limitations of the qualitative method. © 2010 Blackwell Verlag GmbH.

  14. Development of new risk based regulations

    International Nuclear Information System (INIS)

    Nielsen, L.

    1999-01-01

    A short presentation of the oil and gas industry in Norway, and a brief overview of the regulatory regime in the petroleum sector in Norway is given. Risk analysis has been performed in Norway since 1981 and the various applications will be described. These risk analyses are quite different from a nuclear PSA and some of these differences will be commented. Risk based optimisation techniques such as RCM (Reliability Centred Maintenance) and Risk Based Inspection is used in the industry, with very limited support from the risk analysis. Some of the limitation that exist when such techniques are imported from other industries will be commented on. NPD (Norwegian Petroleum Directorate) is revising our regulations and some of the future plants when it comes to risk informed regulatory requirements will be presented. (au)

  15. 31 CFR 223.11 - Limitation of risk: Protective methods.

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 2 2010-07-01 2010-07-01 false Limitation of risk: Protective methods. 223.11 Section 223.11 Money and Finance: Treasury Regulations Relating to Money and Finance... BUSINESS WITH THE UNITED STATES § 223.11 Limitation of risk: Protective methods. The limitation of risk...

  16. Risk based surveillance for vector borne diseases

    DEFF Research Database (Denmark)

    Bødker, Rene

    of samples and hence early detection of outbreaks. Models for vector borne diseases in Denmark have demonstrated dramatic variation in outbreak risk during the season and between years. The Danish VetMap project aims to make these risk based surveillance estimates available on the veterinarians smart phones...... in Northern Europe. This model approach may be used as a basis for risk based surveillance. In risk based surveillance limited resources for surveillance are targeted at geographical areas most at risk and only when the risk is high. This makes risk based surveillance a cost effective alternative...... sample to a diagnostic laboratory. Risk based surveillance models may reduce this delay. An important feature of risk based surveillance models is their ability to continuously communicate the level of risk to veterinarians and hence increase awareness when risk is high. This is essential for submission...

  17. A Risk-Limiting Audit In Denmark: A Pilot

    DEFF Research Database (Denmark)

    Schürmann, Carsten

    2017-01-01

    The theory of risk-limiting audits is well-understood, at least mathematically. Such audits serve to create confidence in the reported election outcome by checking the evidence created during the election. When election officials introduce election technologies into the voting process, it is best...... to do this after the appropriate auditing framework has been implemented. In this paper, we describe our experiences with piloting a risk-limiting audit of a referendum that was held in Denmark on December 3, 2015. At the time of the publication of this paper, Denmark’s election law did not permit...... electronic voting technologies to be used during voting allowing us to study auditing in isolation. Our findings are that (1) risk-limiting audits also apply to paper and pencil elections; (2) election officials usually support risk-limiting audits even if no voting technologies are used because these audits...

  18. Activity Limitation Stages Are Associated With Risk of Hospitalization Among Medicare Beneficiaries.

    Science.gov (United States)

    Na, Ling; Pan, Qiang; Xie, Dawei; Kurichi, Jibby E; Streim, Joel E; Bogner, Hillary R; Saliba, Debra; Hennessy, Sean

    2017-05-01

    Activity limitation stages based on activities of daily living (ADLs) and instrumental activities of daily living (IADLs) are associated with 3-year mortality in elderly Medicare beneficiaries, yet their associations with hospitalization risk in this population have not been studied. To examine the independent association of activity limitation stages with risk of hospitalization within a year among Medicare beneficiaries aged 65 years and older. Cohort study. Community. A total of 9447 community-dwelling elderly Medicare beneficiaries from the Medicare Current Beneficiary Survey for years 2005-2009. Stages were derived for ADLs and IADLs separately. Associations of stages with time to first hospitalization and time to recurrent hospitalizations within a year were assessed with Cox proportional hazards models, with which we accounted for baseline sociodemographics, smoking status, comorbidities, and the year of survey entry. Time to first hospitalization and time to recurrent hospitalizations within 1 year. The adjusted risk of first hospitalization increased with greater activity limitation stages (except stage III). The hazard ratios (95% confidence intervals) for ADL stages I-IV compared with stage 0 (no limitations) were 1.49 (1.36-1.63), 1.61 (1.44-1.80), 1.54 (1.35-1.76), and 2.06 (1.61-2.63), respectively. The pattern for IADL stages was similar. For recurrent hospitalizations, activity limitation stages were associated with the risk of the first hospitalization but not with subsequent hospitalizations. Activity limitation stages are associated with the risk of first hospitalization in the subsequent year among elderly Medicare beneficiaries. Stages capture clinically interpretable profiles of ADL and IADL functionality and describe preserved functions and activity limitation in an aggregated measure. Stage can inform interventions to ameliorate disability and thus reduce the risk of a subsequent hospitalization in this population. IV. Copyright © 2017

  19. Obesity as a risk factor for developing functional limitation among older adults: A conditional inference tree analysis.

    Science.gov (United States)

    Cheng, Feon W; Gao, Xiang; Bao, Le; Mitchell, Diane C; Wood, Craig; Sliwinski, Martin J; Smiciklas-Wright, Helen; Still, Christopher D; Rolston, David D K; Jensen, Gordon L

    2017-07-01

    To examine the risk factors of developing functional decline and make probabilistic predictions by using a tree-based method that allows higher order polynomials and interactions of the risk factors. The conditional inference tree analysis, a data mining approach, was used to construct a risk stratification algorithm for developing functional limitation based on BMI and other potential risk factors for disability in 1,951 older adults without functional limitations at baseline (baseline age 73.1 ± 4.2 y). We also analyzed the data with multivariate stepwise logistic regression and compared the two approaches (e.g., cross-validation). Over a mean of 9.2 ± 1.7 years of follow-up, 221 individuals developed functional limitation. Higher BMI, age, and comorbidity were consistently identified as significant risk factors for functional decline using both methods. Based on these factors, individuals were stratified into four risk groups via the conditional inference tree analysis. Compared to the low-risk group, all other groups had a significantly higher risk of developing functional limitation. The odds ratio comparing two extreme categories was 9.09 (95% confidence interval: 4.68, 17.6). Higher BMI, age, and comorbid disease were consistently identified as significant risk factors for functional decline among older individuals across all approaches and analyses. © 2017 The Obesity Society.

  20. RiskREP: Risk-Based Security Requirements Elicitation and Prioritization (extended version)

    NARCIS (Netherlands)

    Herrmann, Andrea; Morali, A.

    2010-01-01

    Today, companies are required to be in control of the security of their IT assets. This is especially challenging in the presence of limited budgets and conflicting requirements. Here, we present Risk-Based Requirements Elicitation and Prioritization (RiskREP), a method for managing IT security

  1. Pill organizers and pill cutters: risks and limitations.

    Science.gov (United States)

    Borja-Oliveira, Caroline Ribeiro de

    2013-02-01

    In this essay, based on documental analysis, the limitations associated with the use of pill organizers and cutters are discussed and analyzed as a matter of public health. The use of the organizers for storing and carrying tablets and capsules exposes these medications to environmental factors from which their original packaging protected them, compromising their stability and safeness. Cutters also pose the additional risk of causing loss of efficacy, adverse reactions and overdose. On the other hand, the user carrying their own medication reflects the balance between autonomy and self-care, and splitting is sometimes required to comply with certain regimens. It can be concluded that healthcare professionals should observe and guide patients and caregivers in order to avoid risks.

  2. Quantitative risk stratification in Markov chains with limiting conditional distributions.

    Science.gov (United States)

    Chan, David C; Pollett, Philip K; Weinstein, Milton C

    2009-01-01

    Many clinical decisions require patient risk stratification. The authors introduce the concept of limiting conditional distributions, which describe the equilibrium proportion of surviving patients occupying each disease state in a Markov chain with death. Such distributions can quantitatively describe risk stratification. The authors first establish conditions for the existence of a positive limiting conditional distribution in a general Markov chain and describe a framework for risk stratification using the limiting conditional distribution. They then apply their framework to a clinical example of a treatment indicated for high-risk patients, first to infer the risk of patients selected for treatment in clinical trials and then to predict the outcomes of expanding treatment to other populations of risk. For the general chain, a positive limiting conditional distribution exists only if patients in the earliest state have the lowest combined risk of progression or death. The authors show that in their general framework, outcomes and population risk are interchangeable. For the clinical example, they estimate that previous clinical trials have selected the upper quintile of patient risk for this treatment, but they also show that expanded treatment would weakly dominate this degree of targeted treatment, and universal treatment may be cost-effective. Limiting conditional distributions exist in most Markov models of progressive diseases and are well suited to represent risk stratification quantitatively. This framework can characterize patient risk in clinical trials and predict outcomes for other populations of risk.

  3. Environmental risk limits for antifouling substances

    International Nuclear Information System (INIS)

    Wezel, Annemarie P. van; Vlaardingen, P. van

    2004-01-01

    In 1989, the EU restricted the use of tributyl-tin (TBT) and the International Maritime Organisation (IMO) decided for a world-wide ban on TBT in 2003. As a replacement for TBT, new antifouling agents are entering the market. Environmental risk limits (ERLs) are derived for substances that are used as TBT-substitutes, i.e. the compounds Irgarol 1051, dichlofluanid, ziram, chlorothalonil and TCMTB. ERLs represent the potential risk of the substances to the ecosystem and are derived using data on (eco)toxicology and environmental chemistry. Only toxicity studies with endpoints related to population dynamics are taken into account. For Irgarol 1051 especially plants appear to be sensitive; the mode of action is inhibition of photosynthetic electron transport. Despite the higher sensitivity of the plants, the calculated ERL for water based on plants only is higher than the ERL based on all data due to the lower variability in the plant only dataset. Because there is a mechanistic basis to state that plants are the most sensitive species, we propose to base the ERL for water on the plants only dataset. As dichlofluanid is highly unstable in the water phase, it is recommended to base the ERL on the metabolites formed and not on the parent compound. No toxicity data of the studied compounds for organisms living in sediments were found, the ERLs for sediment are derived with help of the equilibrium partitioning method. For dichlofluanid and chlorothalonil the ERL for soil is directly based on terrestrial data, for Irgarol 1051 and ziram the ERL for soil is derived using equilibrium partitioning. Except for Irgarol 1051, no information was encountered in the open literature on the environmental occurrence in The Netherlands of the chemicals studied. The measured concentrations for Irgarol 1051 are close to the derived ERL. For this compound it is concluded that the species composition and thereby ecosystem functioning cannot be considered as protected

  4. Environmental risk limits for antifouling substances

    Energy Technology Data Exchange (ETDEWEB)

    Wezel, Annemarie P. van; Vlaardingen, P. van

    2004-03-10

    In 1989, the EU restricted the use of tributyl-tin (TBT) and the International Maritime Organisation (IMO) decided for a world-wide ban on TBT in 2003. As a replacement for TBT, new antifouling agents are entering the market. Environmental risk limits (ERLs) are derived for substances that are used as TBT-substitutes, i.e. the compounds Irgarol 1051, dichlofluanid, ziram, chlorothalonil and TCMTB. ERLs represent the potential risk of the substances to the ecosystem and are derived using data on (eco)toxicology and environmental chemistry. Only toxicity studies with endpoints related to population dynamics are taken into account. For Irgarol 1051 especially plants appear to be sensitive; the mode of action is inhibition of photosynthetic electron transport. Despite the higher sensitivity of the plants, the calculated ERL for water based on plants only is higher than the ERL based on all data due to the lower variability in the plant only dataset. Because there is a mechanistic basis to state that plants are the most sensitive species, we propose to base the ERL for water on the plants only dataset. As dichlofluanid is highly unstable in the water phase, it is recommended to base the ERL on the metabolites formed and not on the parent compound. No toxicity data of the studied compounds for organisms living in sediments were found, the ERLs for sediment are derived with help of the equilibrium partitioning method. For dichlofluanid and chlorothalonil the ERL for soil is directly based on terrestrial data, for Irgarol 1051 and ziram the ERL for soil is derived using equilibrium partitioning. Except for Irgarol 1051, no information was encountered in the open literature on the environmental occurrence in The Netherlands of the chemicals studied. The measured concentrations for Irgarol 1051 are close to the derived ERL. For this compound it is concluded that the species composition and thereby ecosystem functioning cannot be considered as protected.

  5. Rhythmic Interlimb Coordination Impairments and the Risk for Developing Mobility Limitations.

    Science.gov (United States)

    James, Eric G; Leveille, Suzanne G; Hausdorff, Jeffrey M; Travison, Thomas; Kennedy, David N; Tucker, Katherine L; Al Snih, Soham; Markides, Kyriakos S; Bean, Jonathan F

    2017-08-01

    The identification of novel rehabilitative impairments that are risk factors for mobility limitations may improve their prevention and treatment among older adults. We tested the hypothesis that impaired rhythmic interlimb ankle and shoulder coordination are risk factors for subsequent mobility limitations among older adults. We conducted a 1-year prospective cohort study of community-dwelling older adults (N = 99) aged 67 years and older who did not have mobility limitations (Short Physical Performance Battery score > 9) at baseline. Participants performed antiphase coordination of the right and left ankles or shoulders while paced by an auditory metronome. Using multivariable logistic regression, we determined odds ratios (ORs) for mobility limitations at 1-year follow-up as a function of coordination variability and asymmetry. After adjusting for age, sex, body mass index, Mini-Mental State Examination score, number of chronic conditions, and baseline Short Physical Performance Battery score, ORs were significant for developing mobility limitations based on a 1 SD difference in the variability of ankle (OR = 1.88; 95% confidence interval [CI]: 1.16-3.05) and shoulder (OR = 1.96; 95% CI: 1.17-3.29) coordination. ORs were significant for asymmetry of shoulder (OR = 2.11; 95% CI: 1.25-3.57), but not ankle (OR = 0.95; 95% CI: 0.59-1.55) coordination. Similar results were found in unadjusted analyses. The results support our hypothesis that impaired interlimb ankle and shoulder coordination are risk factors for the development of mobility limitations. Future work is needed to further examine the peripheral and central mechanisms underlying this relationship and to test whether enhancing coordination alters mobility limitations. © The Author 2016. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  6. Usefulness and limitations of global flood risk models

    Science.gov (United States)

    Ward, Philip; Jongman, Brenden; Salamon, Peter; Simpson, Alanna; Bates, Paul; De Groeve, Tom; Muis, Sanne; Coughlan de Perez, Erin; Rudari, Roberto; Mark, Trigg; Winsemius, Hessel

    2016-04-01

    Global flood risk models are now a reality. Initially, their development was driven by a demand from users for first-order global assessments to identify risk hotspots. Relentless upward trends in flood damage over the last decade have enhanced interest in such assessments. The adoption of the Sendai Framework for Disaster Risk Reduction and the Warsaw International Mechanism for Loss and Damage Associated with Climate Change Impacts have made these efforts even more essential. As a result, global flood risk models are being used more and more in practice, by an increasingly large number of practitioners and decision-makers. However, they clearly have their limits compared to local models. To address these issues, a team of scientists and practitioners recently came together at the Global Flood Partnership meeting to critically assess the question 'What can('t) we do with global flood risk models?'. The results of this dialogue (Ward et al., 2013) will be presented, opening a discussion on similar broader initiatives at the science-policy interface in other natural hazards. In this contribution, examples are provided of successful applications of global flood risk models in practice (for example together with the World Bank, Red Cross, and UNISDR), and limitations and gaps between user 'wish-lists' and model capabilities are discussed. Finally, a research agenda is presented for addressing these limitations and reducing the gaps. Ward et al., 2015. Nature Climate Change, doi:10.1038/nclimate2742

  7. Risk newsboy: approach for addressing uncertainty in developing action levels and cleanup limits

    International Nuclear Information System (INIS)

    Cooke, Roger; MacDonell, Margaret

    2007-01-01

    Site cleanup decisions involve developing action levels and residual limits for key contaminants, to assure health protection during the cleanup period and into the long term. Uncertainty is inherent in the toxicity information used to define these levels, based on incomplete scientific knowledge regarding dose-response relationships across various hazards and exposures at environmentally relevant levels. This problem can be addressed by applying principles used to manage uncertainty in operations research, as illustrated by the newsboy dilemma. Each day a newsboy must balance the risk of buying more papers than he can sell against the risk of not buying enough. Setting action levels and cleanup limits involves a similar concept of balancing and distributing risks and benefits in the face of uncertainty. The newsboy approach can be applied to develop health-based target concentrations for both radiological and chemical contaminants, with stakeholder input being crucial to assessing 'regret' levels. Associated tools include structured expert judgment elicitation to quantify uncertainty in the dose-response relationship, and mathematical techniques such as probabilistic inversion and iterative proportional fitting. (authors)

  8. Risk assessment applications for determining cleanup limits for uranium in treated and untreated soils

    International Nuclear Information System (INIS)

    Armstrong, A.Q.; Layton, D.W.; Rutz, E.E.

    1994-01-01

    Uranium-contaminated soils are present at various locations across the US where uranium was processed for nuclear fuels or atomic weapons. Important issues relative to such contamination include the assessment of potential health risks associated with human exposures to the residual uranium and the determination of safe levels of uranium in soils that have been treated by a given technology. This paper discusses various risk assessment considerations that must be dealt with when developing cleanup limits for uranium in treated and untreated soils. Key issues addressed include alternative land use scenarios, potential exposure pathways, characterization of the bioavailability of uranium compounds in food and water, a brief overview of health risks associated with uranium and its daughter products as well as a summary of considerations for development of risk-based cleanup limits for uranium in soils

  9. Revision of risk estimates and implications for dose limits

    International Nuclear Information System (INIS)

    Clarke, R.H.

    1989-01-01

    It has been apparent for some time that our estimates of the risks associated with exposure to ionizing radiation must be increased above those values reported by UNSCEAR in 1977 an dused by ICRP to form their present recommendations. NRPB foresaw some of these changes and introduced interim advice within the UK to restrict exposures of wordkers and members of the public to levels below the existing limits. Since that advice was given, UNSCEAR has produced a 1988 report reviewing human data to provide new estimates of risks associated with exposure at high doses and high doserates. These risk figures are up to 4 times higher than when UNSCEAR reported in 1977. In this paper, the reasons for the changes in the estimates of risk will be described and the current NRPB guidelines for risk factors for protection purposes will be presented. The implications of these new risk factors for the setting of dose limits will then be discussed. (Author). 10 refs.; 2 tabs

  10. Developing of risk-hedging CO2-emission policy. Part II: risks associated with measures to limit emissions, synthesis and conclusions

    International Nuclear Information System (INIS)

    Harvey, L.D.D.

    1996-01-01

    This paper is Part II of a two-part series in which the risk associated with unrestrained greenhouse-gas emissions, and with measures to limit emissions, are reviewed. The following risks associated with these efforts to limit CO 2 emissions are reviewed here: (1) resources might be diverted from other urgent needs; (2) economic growth might be reduced; (3) reduction measures might cost more than expected; (4) early action might cost more than later action; (5) reduction measures might have undesired side effects; (6) reduction measures might require heavy-handed government intervention; and (7) reduction measures might not work. With gradual implementation of a diversified portfolio of measures, these risks can be greatly reduced. Based on the review of risks associated with measures to limit emissions here, and the review of the risk associated with unrestrained emissions presented in Part I, it is concluded that a reasonable near-term (20-30 year) risk hedging strategy is one which seeks to stabilize global fossil CO 2 emissions at the present (early 1990s) level. This is turn implies an emission reduction of 26% for industrialized countries as a whole and 40-50% for Canada and the USA if developing country emissions are to increase by no more than 60%, which in itself would require major assistance from the industrialized countries. The framework and conclusions presented here are critically compared with so-called optimization frameworks. 82 refs., 2 figs., 2 tabs

  11. Aging and Cardiometabolic Risk in European HEMS Pilots: An Assessment of Occupational Old-Age Limits as a Regulatory Risk Management Strategy.

    Science.gov (United States)

    Bauer, Hans; Nowak, Dennis; Herbig, Britta

    2017-12-11

    Old-age limits are imposed in some occupations in an effort to ensure public safety. In aviation, the "Age 60 Rule" limits permissible flight operations conducted by pilots aged 60 and over. Using a retrospective cohort design, we assessed this rule's validity by comparing age-related change rates of cardiometabolic incapacitation risk markers in European helicopter emergency medical service (HEMS) pilots near age 60 with those in younger pilots. Specifically, individual clinical, laboratory, and electrocardiogram (ECG)-based risk markers and an overall cardiovascular event risk score were determined from aeromedical examination records of 66 German, Austrian, Polish, and Czech HEMS pilots (average follow-up 8.52 years). Risk marker change rates were assessed using linear mixed models and generalized additive models. Body mass index increases over time were slower in pilots near age 60 compared to younger pilots, and fasting glucose levels increased only in the latter. Whereas the lipid profile remained unchanged in the latter, it improved in the former. An ECG-based arrhythmia risk marker increased in younger pilots, which persisted in the older pilots. Six-month risk of a fatal cardiovascular event (in or out of cockpit) was estimated between 0% and 0.3%. Between 41% and 95% of risk marker variability was due to unexplained time-stable between-person differences. To conclude, the cardiometabolic risk marker profile of HEMS pilots appears to improve over time in pilots near age 60, compared to younger pilots. Given large stable interindividual differences, we recommend individualized risk assessment of HEMS pilots near age 60 instead of general grounding. © 2017 Society for Risk Analysis.

  12. Prevention and risks limitation of the radioactive installations

    International Nuclear Information System (INIS)

    San Segundo, T.

    1983-01-01

    Associated risks to the ionizing radiation, in general, and to the radioactive installations, in particular, are exposed; as well as the prevention and limitation techniques applied in order to keep risk into acceptable levels are detatched. Finally, the effect in the human life of the radioactivity use and other activities are compared and man-made occupational and public exposures are explained. (author)

  13. Acute Kidney Injury Risk Assessment: Differences and Similarities Between Resource-Limited and Resource-Rich Countries

    Directory of Open Access Journals (Sweden)

    Kianoush Kashani

    2017-07-01

    Full Text Available The incidence of acute kidney injury (AKI among acutely ill patients is reportedly very high and has vexing consequences on patient outcomes and health care systems. The risks and impact of AKI differ between developed and developing countries. Among developing countries, AKI occurs in young individuals with no or limited comorbidities, and is usually due to environmental causes, including infectious diseases. Although several risk factors have been identified for AKI in different settings, there is limited information on how risk assessment can be used at population and patient levels to improve care in patients with AKI, particularly in developing countries where significant health disparities may exist. The Acute Disease Quality Initiative consensus conference work group addressed the issue of identifying risk factors for AKI and provided recommendations for developing individualized risk stratification strategies to improve care. We proposed a 5-dimension, evidence-based categorization of AKI risk that allows clinicians and investigators to study, define, and implement individualized risk assessment tools for the region or country where they practice. These dimensions include environmental, socioeconomic and cultural factors, processes of care, exposures, and the inherent risks of AKI. We provide examples of these risks and describe approaches for risk assessments in the developing world. We anticipate that these recommendations will be useful for health care providers to plan and execute interventions to limit the impact of AKI on society and each individual patient. Using a modified Delphi process, this group reached consensus regarding several aspects of AKI risk stratification.

  14. Dose limits cause unacceptable risk

    International Nuclear Information System (INIS)

    Collier, Sylvia.

    1985-01-01

    This paper on radiation dose limits for workers and the public discusses the following: Medical Research Council report; safety standards; risk assessment; deaths from cancers; biological radiation effects; UK legislation; low-level radiation; public concern; UKAEA staff survey; Ionising Radiations Regulations; United Nations Scientific Committee on Effects of Atomic Radiation; US studies on work force in nuclear establishments; problems of extrapolation; Japanese data from Hiroshima and Nagasaki; International Commission on Radiological Protection recommendations; studies on uranium miners; UK Health and Safety Executive; UK National Radiological Protection Board. (U.K.)

  15. Limits of Risk Predictability in a Cascading Alternating Renewal Process Model.

    Science.gov (United States)

    Lin, Xin; Moussawi, Alaa; Korniss, Gyorgy; Bakdash, Jonathan Z; Szymanski, Boleslaw K

    2017-07-27

    Most risk analysis models systematically underestimate the probability and impact of catastrophic events (e.g., economic crises, natural disasters, and terrorism) by not taking into account interconnectivity and interdependence of risks. To address this weakness, we propose the Cascading Alternating Renewal Process (CARP) to forecast interconnected global risks. However, assessments of the model's prediction precision are limited by lack of sufficient ground truth data. Here, we establish prediction precision as a function of input data size by using alternative long ground truth data generated by simulations of the CARP model with known parameters. We illustrate the approach on a model of fires in artificial cities assembled from basic city blocks with diverse housing. The results confirm that parameter recovery variance exhibits power law decay as a function of the length of available ground truth data. Using CARP, we also demonstrate estimation using a disparate dataset that also has dependencies: real-world prediction precision for the global risk model based on the World Economic Forum Global Risk Report. We conclude that the CARP model is an efficient method for predicting catastrophic cascading events with potential applications to emerging local and global interconnected risks.

  16. Application of the risk-informed methodology for APR1400 P-T limits curve

    Energy Technology Data Exchange (ETDEWEB)

    Kim, K.; Namgung, I. [KEPCO International Nuclear Graduate School, Ulsan (Korea, Republic of)

    2014-07-01

    A reactor pressure vessel (RPV) in a nuclear power plant has operational limits of pressure and temperature to prevent a potential drastic propagation of cracks due to brittle fracture. We call it a pressure-temperature limits curve (P-T limits curve). Appendix G of the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code, Section XI, provides deterministic procedures to develop the P-T limits curve for the reactor pressure vessel. Recently, an alternative risk-informed methodology has been added in the ASME Code. Risk-informed means that we can consider insights from a probabilistic risk assessment by using this methodology. This alternative methodology provides a simple procedure to develop risk-informed P-T limits for heat up, cool down, and hydrostatic test events. The risk-informed P-T limits curve is known to provide more operational flexibility, particularly for reactor pressure vessels with relatively high irradiation levels and radiation sensitive materials. In this paper, we developed both the deterministic and a risk-informed P-T limits curve for an APR1400 reactor using Appendix G of the ASME Code, Section XI and compare the results in terms of additional operational margin. (author)

  17. A Risk Based Approach to Limit the Effects of Covert Channels for Internet Sensor Data Aggregators for Sensor Privacy

    Science.gov (United States)

    Viecco, Camilo H.; Camp, L. Jean

    Effective defense against Internet threats requires data on global real time network status. Internet sensor networks provide such real time network data. However, an organization that participates in a sensor network risks providing a covert channel to attackers if that organization’s sensor can be identified. While there is benefit for every party when any individual participates in such sensor deployments, there are perverse incentives against individual participation. As a result, Internet sensor networks currently provide limited data. Ensuring anonymity of individual sensors can decrease the risk of participating in a sensor network without limiting data provision.

  18. Agent-Based Modelling for Security Risk Assessment

    NARCIS (Netherlands)

    Janssen, S.A.M.; Sharpans'kykh, Alexei; Bajo, J.; Vale, Z.; Hallenborg, K.; Rocha, A.P.; Mathieu, P.; Pawlewski, P.; Del Val, E.; Novais, P.; Lopes, F.; Duque Méndez, N.D.; Julián, V.; Holmgren, J.

    2017-01-01

    Security Risk Assessment is commonly performed by using traditional methods based on linear probabilistic tools and informal expert judgements. These methods lack the capability to take the inherent dynamic and intelligent nature of attackers into account. To partially address the limitations,

  19. 31 CFR 223.10 - Limitation of risk.

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 2 2010-07-01 2010-07-01 false Limitation of risk. 223.10 Section 223.10 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) FISCAL SERVICE, DEPARTMENT OF THE TREASURY FINANCIAL MANAGEMENT SERVICE SURETY COMPANIES DOING BUSINESS WITH THE...

  20. Automatic Margin Computation for Risk-Limiting Audits

    DEFF Research Database (Denmark)

    Beckert, Bernhard; Kirsten, Michael; Klebanov, Vladimir

    2017-01-01

    A risk-limiting audit is a statistical method to create confidence in the correctness of an election result by checking samples of paper ballots. In order to perform an audit, one usually needs to know what the election margin is, i.e., the number of votes that would need to be changed in order...

  1. Quantification of Technology Innovation Usinga Risk-Based Framework

    OpenAIRE

    Gerard E. Sleefe

    2010-01-01

    There is significant interest in achieving technology innovation through new product development activities. It is recognized, however, that traditional project management practices focused only on performance, cost, and schedule attributes, can often lead to risk mitigation strategies that limit new technology innovation. In this paper, a new approach is proposed for formally managing and quantifying technology innovation. This approach uses a risk-based framework that s...

  2. The global limits and population at risk of soil-transmitted helminth infections in 2010

    Directory of Open Access Journals (Sweden)

    Pullan Rachel L

    2012-04-01

    Full Text Available Abstract Background Understanding the global limits of transmission of soil-transmitted helminth (STH species is essential for quantifying the population at-risk and the burden of disease. This paper aims to define these limits on the basis of environmental and socioeconomic factors, and additionally seeks to investigate the effects of urbanisation and economic development on STH transmission, and estimate numbers at-risk of infection with Ascaris lumbricoides, Trichuris trichiura and hookworm in 2010. Methods A total of 4,840 geo-referenced estimates of infection prevalence were abstracted from the Global Atlas of Helminth Infection and related to a range of environmental factors to delineate the biological limits of transmission. The relationship between STH transmission and urbanisation and economic development was investigated using high resolution population surfaces and country-level socioeconomic indicators, respectively. Based on the identified limits, the global population at risk of STH transmission in 2010 was estimated. Results High and low land surface temperature and extremely arid environments were found to limit STH transmission, with differential limits identified for each species. There was evidence that the prevalence of A. lumbricoides and of T. trichiura infection was statistically greater in peri-urban areas compared to urban and rural areas, whilst the prevalence of hookworm was highest in rural areas. At national levels, no clear socioeconomic correlates of transmission were identified, with the exception that little or no infection was observed for countries with a per capita gross domestic product greater than US$ 20,000. Globally in 2010, an estimated 5.3 billion people, including 1.0 billion school-aged children, lived in areas stable for transmission of at least one STH species, with 69% of these individuals living in Asia. A further 143 million (31.1 million school-aged children lived in areas of unstable

  3. Overview of Risk Mitigation for Safety-Critical Computer-Based Systems

    Science.gov (United States)

    Torres-Pomales, Wilfredo

    2015-01-01

    This report presents a high-level overview of a general strategy to mitigate the risks from threats to safety-critical computer-based systems. In this context, a safety threat is a process or phenomenon that can cause operational safety hazards in the form of computational system failures. This report is intended to provide insight into the safety-risk mitigation problem and the characteristics of potential solutions. The limitations of the general risk mitigation strategy are discussed and some options to overcome these limitations are provided. This work is part of an ongoing effort to enable well-founded assurance of safety-related properties of complex safety-critical computer-based aircraft systems by developing an effective capability to model and reason about the safety implications of system requirements and design.

  4. Perception of mobile phone and base station risks.

    Science.gov (United States)

    Siegrist, Michael; Earle, Timothy C; Gutscher, Heinz; Keller, Carmen

    2005-10-01

    Perceptions of risks associated with mobile phones, base stations, and other sources of electromagnetic fields (EMF) were examined. Data from a telephone survey conducted in the German- and French-speaking parts of Switzerland are presented (N = 1,015). Participants assessed both risks and benefits associated with nine different sources of EMF. Trust in the authorities regulating these hazards was assessed as well. In addition, participants answered a set of questions related to attitudes toward EMF and toward mobile phone base stations. According to respondents' assessments, high-voltage transmission lines are the most risky source of EMF. Mobile phones and mobile phone base stations received lower risk ratings. Results showed that trust in authorities was positively associated with perceived benefits and negatively associated with perceived risks. People who use their mobile phones frequently perceived lower risks and higher benefits than people who use their mobile phones infrequently. People who believed they lived close to a base station did not significantly differ in their level of risks associated with mobile phone base stations from people who did not believe they lived close to a base station. Regarding risk regulation, a majority of participants were in favor of fixing limiting values based on the worst-case scenario. Correlations suggest that belief in paranormal phenomena is related to level of perceived risks associated with EMF. Furthermore, people who believed that most chemical substances cause cancer also worried more about EMF than people who did not believe that chemical substances are that harmful. Practical implications of the results are discussed.

  5. Bioassay-based risk assessment of complex mixtures

    International Nuclear Information System (INIS)

    Donnelly, K.C.; Huebner, H.J.

    1996-01-01

    The baseline risk assessment often plays an integral role in various decision-making processes at Superfund sites. The present study reports on risk characterizations prepared for seven complex mixtures using biological and chemical analysis. Three of the samples (A, B, and C) were complex mixtures of polycyclic aromatic hydrocarbons (PAHs) extracted from coal tar; while four samples extracted from munitions-contaminated soil contained primarily nitroaromatic hydrocarbons. The chemical-based risk assessment ranked sample C as least toxic, while the risk associated with samples A and B was approximately equal. The microbial bioassay was in general agreement for the coal tar samples. The weighted activity of the coal tar extracts in Salmonella was 4,960 for sample C, and 162,000 and 206,000 for samples A and B, respectively. The bacterial mutagenicity of 2,4,6-trinitrotoluene contaminated soils exhibited an indirect correlation with chemical-based risk assessment. The aqueous extract of sample 004 induced 1,292 net revertants in Salmonella, while the estimated risk to ingestion and dermal adsorption was 2E-9. The data indicate that the chemical-based risk assessment accurately predicted the genotoxicity of the PAHs, while the accuracy of the risk assessment for munitions contaminated soils was limited due to the presence of metabolites of TNT degradation. The biological tests used in this research provide a valuable compliment to chemical analysis for characterizing the genotoxic risk of complex mixtures

  6. Handbook of methods for risk-based analysis of technical specifications

    International Nuclear Information System (INIS)

    Samanta, P.K.; Kim, I.S.; Mankamo, T.; Vesely, W.E.

    1996-01-01

    Technical Specifications (TS) requirements for nuclear power plants define the Limiting Conditions for Operations (LCOs) and Surveillance Requirements (SRs) to assure safety during operation. In general, these requirements are based on deterministic analyses and engineering judgments. Improvements in these requirements are facilitated by the availability of plant-specific Probabilistic Risk Assessments (PRAs). The US Nuclear Regulatory Commission (USNRC) Office of Research sponsored research to develop systematic, risk-based methods to improve various aspects of TS requirements. A handbook of methods summarizing such risk-based approaches has been completed in 1994. It is expected that this handbook will provide valuable input to NRC's present work in developing guidance for using PRA in risk-informed regulation. The handbook addresses reliability and risk-based methods for evaluating allowed outage times (AOTs), action statements requiring shutdown where shutdown risk may be substantial, surveillance test intervals (STIs), managing plant configurations, and scheduling maintenance

  7. A risk modelling approach for setting microbiological limits using enterococci as indicator for growth potential of Salmonella in pork.

    Science.gov (United States)

    Bollerslev, Anne Mette; Nauta, Maarten; Hansen, Tina Beck; Aabo, Søren

    2017-01-02

    Microbiological limits are widely used in food processing as an aid to reduce the exposure to hazardous microorganisms for the consumers. However, in pork, the prevalence and concentrations of Salmonella are generally low and microbiological limits are not considered an efficient tool to support hygiene interventions. The objective of the present study was to develop an approach which could make it possible to define potential risk-based microbiological limits for an indicator, enterococci, in order to evaluate the risk from potential growth of Salmonella. A positive correlation between the concentration of enterococci and the prevalence and concentration of Salmonella was shown for 6640 pork samples taken at Danish cutting plants and retail butchers. The samples were collected in five different studies in 2001, 2002, 2010, 2011 and 2013. The observations that both Salmonella and enterococci are carried in the intestinal tract, contaminate pork by the same mechanisms and share similar growth characteristics (lag phase and maximum specific growth rate) at temperatures around 5-10°C, suggest a potential of enterococci to be used as an indicator of potential growth of Salmonella in pork. Elevated temperatures during processing will lead to growth of both enterococci and, if present, also Salmonella. By combining the correlation between enterococci and Salmonella with risk modelling, it is possible to predict the risk of salmonellosis based on the level of enterococci. The risk model used for this purpose includes the dose-response relationship for Salmonella and a reduction factor to account for preparation of the fresh pork. By use of the risk model, it was estimated that the majority of salmonellosis cases, caused by the consumption of pork in Denmark, is caused by the small fraction of pork products that has enterococci concentrations above 5logCFU/g. This illustrates that our approach can be used to evaluate the potential effect of different microbiological

  8. Risk factors for mobility limitation in community-dwelling older adults: a social ecological perspective.

    Science.gov (United States)

    Yeom, Hye A; Fleury, Julie; Keller, Colleen

    2008-01-01

    Although a variety of risk factors for mobility limitation in older adults have been examined, a collective review of relevant literature has not been reported. The purposes of this review are to report the intrapersonal, interpersonal, environmental, and organizational risk factors related to mobility limitation using a social ecological perspective and to discuss the direction of future clinical practice consistent with current literature on mobility limitation of community-dwelling older adults. Intrapersonal risk factors related to mobility limitation include advanced age, female gender, low socioeconomic status, comorbidity, lack of motivation (i.e., dependent personality, decreased self-efficacy), lifestyle factors (i.e., sedentary lifestyle, smoking, obesity), and physiological factors (i.e., vitamin D deficiency, inflammation, poor nutritional status). Interpersonal risk factors related to mobility limitation include weak social networks and limited social activities. Geriatric clients may also experience a decline in mobility when they encounter environmental challenges such as an inconvenient home environment and lack of availability of services in their community, as well as lack of organizational resources stemming from social policy. Potential intervention strategies focused on modifiable risk factors may include lifestyle modifications, social networking programs, and enhancing awareness of environmental and organizational resources in the community for older adults at risk for mobility limitation.

  9. NASA Space Radiation Protection Strategies: Risk Assessment and Permissible Exposure Limits

    Science.gov (United States)

    Huff, J. L.; Patel, Z. S.; Simonsen, L. C.

    2017-01-01

    Permissible exposure limits (PELs) for short-term and career astronaut exposures to space radiation have been set and approved by NASA with the goal of protecting astronauts against health risks associated with ionizing radiation exposure. Short term PELs are intended to prevent clinically significant deterministic health effects, including performance decrements, which could threaten astronaut health and jeopardize mission success. Career PELs are implemented to control late occurring health effects, including a 3% risk of exposure induced death (REID) from cancer, and dose limits are used to prevent cardiovascular and central nervous system diseases. For radiation protection, meeting the cancer PEL is currently the design driver for galactic cosmic ray and solar particle event shielding, mission duration, and crew certification (e.g., 1-year ISS missions). The risk of cancer development is the largest known long-term health consequence following radiation exposure, and current estimates for long-term health risks due to cardiovascular diseases are approximately 30% to 40% of the cancer risk for exposures above an estimated threshold (Deep Space one-year and Mars missions). Large uncertainties currently exist in estimating the health risks of space radiation exposure. Improved understanding through radiobiology and physics research allows increased accuracy in risk estimation and is essential for ensuring astronaut health as well as for controlling mission costs, optimization of mission operations, vehicle design, and countermeasure assessment. We will review the Space Radiation Program Element's research strategies to increase accuracy in risk models and to inform development and validation of the permissible exposure limits.

  10. 26 CFR 5.1502-45 - Limitation on losses to amount at risk.

    Science.gov (United States)

    2010-04-01

    ... 26 Internal Revenue 14 2010-04-01 2010-04-01 false Limitation on losses to amount at risk. 5.1502... Limitation on losses to amount at risk. (a) In general—(1) Scope. This section applies to a loss of any subsidiary if the common parent's stock meets the stock ownership requirement described in section 465(a)(1...

  11. Risk-based configuration control system: Analysis and approaches

    International Nuclear Information System (INIS)

    Samanta, P.K.; Kim, I.S.; Vesely, W.E.; Lofgren, E.V.

    1989-01-01

    This paper presents an evaluation of the configuration risks associated with the operation of a nuclear power plant and the approaches to control these risks using risk-based configuration control considerations. In that context, the actual and maximum potential configuration risks at a plant are analyzed and the alternative types criteria for a risk-based configuration control systems are described. The risk-based configuration calculations which are studied here focus on the core-melt frequency impacts from given plant configurations. By calculating the core-melt frequency for given configurations, the configurations which cause large core-melt frequency increases can be identified and controlled. The duration time in which the configuration can exist can then be limited or the core-melt frequency level associated with the configuration can be reduced by various actions. Furthermore, maintenances and tests can be scheduled to avoid the configurations which cause large core-melt frequency increases. Present technical specifications do not control many of these configurations which can cause large core-melt frequency increases but instead focus on many risk-unimportant allowed outage times. Hence, risk-based configuration management can be effectively used to reduce core-melt frequency associated risks at a plant and at the same time can provide flexibility in plant operation. The alternative strategies for controlling the core-melt frequency and other risk contributions include: (1) controlling the increased risk level which is associated with the configuration; (2) controlling the individual configuration risk which is associated with a given duration of a configuration; (3) controlling the time period configuration risk from configurations which occur in a time period

  12. Risk-based safety indicators

    International Nuclear Information System (INIS)

    Szikszai, T.

    1997-01-01

    The presentation discusses the following issues: The objectives of the risk-based indicator programme. The characteristics of the risk-based indicators. The objectives of risk-based safety indicators - in monitoring safety; in PSA applications. What indicators? How to produce the risk based indicators? PSA requirements

  13. Risk based modelling

    International Nuclear Information System (INIS)

    Chapman, O.J.V.; Baker, A.E.

    1993-01-01

    Risk based analysis is a tool becoming available to both engineers and managers to aid decision making concerning plant matters such as In-Service Inspection (ISI). In order to develop a risk based method, some form of Structural Reliability Risk Assessment (SRRA) needs to be performed to provide a probability of failure ranking for all sites around the plant. A Probabilistic Risk Assessment (PRA) can then be carried out to combine these possible events with the capability of plant safety systems and procedures, to establish the consequences of failure for the sites. In this way the probability of failures are converted into a risk based ranking which can be used to assist the process of deciding which sites should be included in an ISI programme. This paper reviews the technique and typical results of a risk based ranking assessment carried out for nuclear power plant pipework. (author)

  14. Informed choice in direct-to-consumer genetic testing (DTCGT) websites: a content analysis of benefits, risks, and limitations.

    Science.gov (United States)

    Singleton, Amanda; Erby, Lori Hamby; Foisie, Kathryn V; Kaphingst, Kimberly A

    2012-06-01

    An informed choice about health-related direct-to-consumer genetic testing (DTCGT) requires knowledge of potential benefits, risks, and limitations. To understand the information that potential consumers of DTCGT services are exposed to on company websites, we conducted a content analysis of 23 health-related DTCGT websites. Results revealed that benefit statements outweighed risk and limitation statements 6 to 1. The most frequently described benefits were: 1) disease prevention, 2) consumer education, 3) personalized medical recommendations, and 4) the ability to make health decisions. Thirty-five percent of websites also presented at least one risk of testing. Seventy-eight percent of websites mentioned at least one limitation of testing. Based on this information, potential consumers might get an inaccurate picture of genetic testing which could impact their ability to make an informed decision. Practices that enhance the presentation of balanced information on DTCGT company websites should be encouraged.

  15. Toward risk-based control of nuclear power plant configurations

    International Nuclear Information System (INIS)

    Samanta, P.K.; Veseley, W.E.; Kim, I.S.

    1992-01-01

    This paper presents an evaluation of the configuration risks associated with the operation of a nuclear power plant and the approaches to control these risks using risk-based configuration control considerations. In that context, the actual and maximum potential configuration risks at a plant are analyzed and the alternative types criteria for a risk-based configuration control systems are described. The risk-based configuration calculations which are studied here focus on the core-melt frequency impacts from given plant configurations, the configurations which cause large core-melt frequency increases can be identified and controlled. The duration time in which the configuration can exist can then be limited or the core-melt frequency level associated with the configuration can be reduced by various actions. Futhermore, maintenances and tests can be scheduled to avoid the configurations which cause large core-melt frequency increases. Present technical specifications do not control many of these configurations which can cause large core-melt frequency increases but instead focus on many risk-unimportant allowed outage times. Hence, risk-based configuration management can be effectively used to reduce core-melt frequency associated risks at a plant and at the same time can provide flexibility in plant operation. The alternative strategies for controlling the core-melt frequency and other risk contributions include: (1) controlling the increased risk level which is associated with the configuration; (2) controlling the individual configuration risk which is associated with a given duration of a configuration; (3) controlling the time period configuration risk from configurations which occur in a time period. (orig.)

  16. The assessment of solvency and determination of limits for risk acceptance in insurance companies

    Directory of Open Access Journals (Sweden)

    Drljača Dejan

    2017-01-01

    Full Text Available The subject of this paper is the presentation of key requirements for Solvency II project, the methodology for testing of capital adequacy and methods for identification, definition and establishment of risk limits, as a limit for acceptance, bearing and control of exposure to certain risks in insurance companies. The aim of the paper is to show that the capital adequacy is the key factor for insurers' safety, i.e. guarantee of capability of an insurer to settle any future liabilities and leverage for strengthening of insurer's market position. Business operations of insurance companies are exposed to a significant number of risks that differ by their nature, character and influence, due to which adequacy of calculated technical reserves does not provide a satisfactory level of safety in case of more significant impairments of assets and funds of insurers, as well as in case of significant deviations between amounts of settled claims and actuarially expected amounts of liabilities based on claims. Stress testing of capital adequacy will show that losses due to impairment of risky securities, difficult collection of low liquid, i.e. securities that are difficult to market, inability to collect receivables from reinsurers, as well as losses due to inadequately calculated reserved claims, must be covered by a solvent capital. The paper is structured so as to provide a review of rules, elements and principles that are the foundation of solvency requirements in insurance companies, methodologies of calculation of guarantee reserve, technical basis for stress testing which assesses capital adequacy of insurers, as well as methods for establishment of limits of exposure to certain risks.

  17. Handbook of methods for risk-based analyses of technical specifications

    International Nuclear Information System (INIS)

    Samanta, P.K.; Kim, I.S.; Mankamo, T.; Vesely, W.E.

    1994-12-01

    Technical Specifications (TS) requirements for nuclear power plants define the Limiting Conditions for Operation (LCOs) and Surveillance Requirements (SRs) to assure safety during operation. In general, these requirements are based on deterministic analysis and engineering judgments. Experiences with plant operation indicate that some elements of the requirements are unnecessarily restrictive, while a few may not be conducive to safety. The US Nuclear Regulatory Commission (USNRC) Office of Research has sponsored research to develop systematic risk-based methods to improve various aspects of TS requirements. This handbook summarizes these risk-based methods. The scope of the handbook includes reliability and risk-based methods for evaluating allowed outage times (AOTs), scheduled or preventive maintenance, action statements requiring shutdown where shutdown risk may be substantial, surveillance test intervals (STIs), and management of plant configurations resulting from outages of systems, or components. For each topic, the handbook summarizes analytic methods with data needs, outlines the insights to be gained, lists additional references, and gives examples of evaluations

  18. Handbook of methods for risk-based analyses of technical specifications

    Energy Technology Data Exchange (ETDEWEB)

    Samanta, P.K.; Kim, I.S. [Brookhaven National Lab., Upton, NY (United States); Mankamo, T. [Avaplan Oy, Espoo (Finland); Vesely, W.E. [Science Applications International Corp., Dublin, OH (United States)

    1994-12-01

    Technical Specifications (TS) requirements for nuclear power plants define the Limiting Conditions for Operation (LCOs) and Surveillance Requirements (SRs) to assure safety during operation. In general, these requirements are based on deterministic analysis and engineering judgments. Experiences with plant operation indicate that some elements of the requirements are unnecessarily restrictive, while a few may not be conducive to safety. The US Nuclear Regulatory Commission (USNRC) Office of Research has sponsored research to develop systematic risk-based methods to improve various aspects of TS requirements. This handbook summarizes these risk-based methods. The scope of the handbook includes reliability and risk-based methods for evaluating allowed outage times (AOTs), scheduled or preventive maintenance, action statements requiring shutdown where shutdown risk may be substantial, surveillance test intervals (STIs), and management of plant configurations resulting from outages of systems, or components. For each topic, the handbook summarizes analytic methods with data needs, outlines the insights to be gained, lists additional references, and gives examples of evaluations.

  19. Task-based dermal exposure models for regulatory risk assessment

    NARCIS (Netherlands)

    Warren, N.D.; Marquart, H.; Christopher, Y.; Laitinen, J.; Hemmen, J.J. van

    2006-01-01

    The regulatory risk assessment of chemicals requires the estimation of occupational dermal exposure. Until recently, the models used were either based on limited data or were specific to a particular class of chemical or application. The EU project RISKOFDERM has gathered a considerable number of

  20. Risk-based remediation of polluted sites: A critical perspective.

    Science.gov (United States)

    Kuppusamy, Saranya; Venkateswarlu, Kadiyala; Megharaj, Mallavarapu; Mayilswami, Srinithi; Lee, Yong Bok

    2017-11-01

    Sites contaminated with chemical pollutants represent a growing challenge, and remediation of such lands is of international concern. Risk-based land management (RBLM) is an emerging approach that integrates risk assessment practices with more traditional site-specific investigations and remediation activities. Developing countries are yet to adopt RBLM strategies for remediation. RBLM is considered to be practical, scientifically defensible and cost-efficient. However, it is inherently limited by: firstly, the accuracy of risk assessment models used; secondly, ramifications of the fact that they are more likely to leave contamination in place; and thirdly, uncertainties involved and having to consider the total concentrations of all contaminants in soils that overestimate the potential risks from exposure to the contaminants. Consideration of contaminant bioavailability as the underlying basis for risk assessment and setting remediation goals of those contaminated lands that pose a risk to environmental and human health may lead to the development of a more sophisticated risk-based approach. However, employing the bioavailability concept in RBLM has not been extensively studied and/or legalized. This review highlights the extent of global land contamination, and the concept of risk-based assessment and management of contaminated sites including its advantages and disadvantages. Furthermore, the concept of bioavailability-based RBLM strategy has been proposed, and the challenges of RBLM and the priority areas for future research are summarized. Thus, the present review may help achieve a better understanding and successful implementation of a sustainable bioavailability-based RBLM strategy. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. IT Operational Risk Measurement Model Based on Internal Loss Data of Banks

    Science.gov (United States)

    Hao, Xiaoling

    Business operation of banks relies increasingly on information technology (IT) and the most important role of IT is to guarantee the operational continuity of business process. Therefore, IT Risk management efforts need to be seen from the perspective of operational continuity. Traditional IT risk studies focused on IT asset-based risk analysis and risk-matrix based qualitative risk evaluation. In practice, IT risk management practices of banking industry are still limited to the IT department and aren't integrated into business risk management, which causes the two departments to work in isolation. This paper presents an improved methodology for dealing with IT operational risk. It adopts quantitative measurement method, based on the internal business loss data about IT events, and uses Monte Carlo simulation to predict the potential losses. We establish the correlation between the IT resources and business processes to make sure risk management of IT and business can work synergistically.

  2. Assessing control of postural stability in community-living older adults using performance-based limits of stability

    DEFF Research Database (Denmark)

    Jbabdi, Myriam; Boissy, Patrice; Hamel, Mathieu

    2008-01-01

    BACKGROUND: Balance disability measurements routinely used to identify fall risks in frail populations have limited value in the early detection of postural stability deficits in community-living older adults. The objectives of the study were to 1) measure performance-based limits of stability (LOS......-session performance variability during multiple trials using the performance-based LOS paradigm. METHODS: Twenty-four healthy community-living older adults (10 men, 14 women) aged between 62 to 85 (mean age +/- sd, 71.5 +/- 6 yrs) participated in the study. Subjects' performance-based LOS were established by asking...

  3. 76 FR 12645 - Ownership Limitations and Governance Requirements for Security-Based Swap Clearing Agencies...

    Science.gov (United States)

    2011-03-08

    ... 3235-AK74 Ownership Limitations and Governance Requirements for Security- Based Swap Clearing Agencies... the Dodd-Frank Act, the Commission shall adopt such rules if it determines that they are necessary or appropriate to improve the governance of, or to mitigate systemic risk, promote competition or mitigate...

  4. Risk-based evaluation of Allowed Outage Times (AOTs) considering risk of shutdown

    International Nuclear Information System (INIS)

    Mankamo, T.; Kim, I.S.; Samanta, P.K.

    1992-01-01

    When safety systems fail during power operation, Technical Specifications (TS) usually limit the repair within Allowed Outage Time (AOT). If the repair cannot be completed within the AOT, or no AOT is allowed, the plant is required to be shut down for the repair. However, if the capability to remove decay heat is degraded, shutting down the plant with the need to operate the affected decay-heat removal systems may impose a substantial risk compared to continued power operation over a usual repair time. Thus, defining a proper AOT in such situations can be considered as a risk-comparison between the repair in frill power state with a temporarily increased level of risk, and the altemative of shutting down the plant for the repair in zero power state with a specific associated risk. The methodology of the risk-comparison approach, with a due consideration of the shutdown risk, has been further developed and applied to the AOT considerations of residual heat removal and standby service water systems of a boiling water reactor (BWR) plant. Based on the completed work, several improvements to the TS requirements for the systems studied can be suggested

  5. Model-based mitigation of availability risks

    NARCIS (Netherlands)

    Zambon, E.; Bolzoni, D.; Etalle, S.; Salvato, M.

    2007-01-01

    The assessment and mitigation of risks related to the availability of the IT infrastructure is becoming increasingly important in modern organizations. Unfortunately, present standards for risk assessment and mitigation show limitations when evaluating and mitigating availability risks. This is due

  6. Model-Based Mitigation of Availability Risks

    NARCIS (Netherlands)

    Zambon, Emmanuele; Bolzoni, D.; Etalle, Sandro; Salvato, Marco

    2007-01-01

    The assessment and mitigation of risks related to the availability of the IT infrastructure is becoming increasingly important in modern organizations. Unfortunately, present standards for Risk Assessment and Mitigation show limitations when evaluating and mitigating availability risks. This is due

  7. Physics-Based Identification, Modeling and Risk Management for Aeroelastic Flutter and Limit-Cycle Oscillations (LCO), Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed research program will develop a physics-based identification, modeling and risk management infrastructure for aeroelastic transonic flutter and...

  8. Attributable risks for childhood overweight: evidence for limited effectiveness of prevention.

    Science.gov (United States)

    Plachta-Danielzik, Sandra; Kehden, Britta; Landsberg, Beate; Schaffrath Rosario, Angelika; Kurth, Bärbel-Maria; Arnold, Christiane; Graf, Christine; Hense, Sabrina; Ahrens, Wolfgang; Müller, Manfred James

    2012-10-01

    Calculation of attributable risks (ARs) of childhood overweight to estimate effectiveness of prevention strategies. We used pooled data of 4 population-based German studies including 34240 children and adolescents aged 3 to 18 years to calculate the impact of familial, social, "early life", and lifestyle factors on overweight. ARs (joint for all determinants as well as partial risks) were calculated. The prevalence of childhood overweight was 13.4%. Successfully tackling all determinants can reduce overweight by 77.7% (ie, from 13.4% to 3.0%; = joint AR) with partial effects of treating parental overweight (42.5%); improving social status (14.3%); reducing media time to lifestyle) the effect is 9.2%. Media time has the strongest effect. The determinants identified explained 78% of the prevalence of overweight. Taking into account the partial ARs, the effectiveness of lifestyle interventions to prevent overweight in children is limited. Our data argue in favor of interventions aimed at families and social environments, with a major focus on promoting a lower screen time and computer use in children.

  9. Electro smog. Health risks, limiting values, consumer protection

    International Nuclear Information System (INIS)

    Karus, M.; Ebert, L.; Schneider, W.; Koehnecke, W.; Loefflad, H.; Plotzke, O.; Niessen, P.

    1994-01-01

    At first, the popular book describes physical facts. All terms and units being necessary for the comprehension of electro smog are presented and referred to practice: Which electric and magnetic fields of natural and technical origin appear in everyday life? The main part of the book occupies physical effects. The current scientific state of the research is presented: Are electric and magnetic fields a physical risk factor? In the chapter 'limiting values', the valid limiting values and their conceptional and political basis are discussed. The last part of the book addresses consumer protection: How can the own load be reduced through electric and magnetic fields of electric devices and installations, computers and mobile telephones without renouncing of electric comfort. (VHE) [de

  10. 77 FR 53059 - Risk-Based Capital Guidelines: Market Risk

    Science.gov (United States)

    2012-08-30

    ...'' framework that includes (1) Risk-based capital requirements for credit risk, market risk, and operational... default and credit quality migration risk for non-securitization credit products. With respect to... securitization positions, the revisions assign a specific risk- weighting factor based on the credit rating of a...

  11. Risk-based safety indicators

    International Nuclear Information System (INIS)

    Sedlak, J.

    2001-12-01

    The report is structured as follows: 1. Risk-based safety indicators: Typology of risk-based indicators (RBIs); Tools for defining RBIs; Requirements for the PSA model; Data sources for RBIs; Types of risks monitored; RBIs and operational safety indicators; Feedback from operating experience; PSO model modification for RBIs; RBI categorization; RBI assessment; RBI applications; Suitable RBI applications. 2. Proposal for risk-based indicators: Acquiring information from operational experience; Method of acquiring safety relevance coefficients for the systems from a PSA model; Indicator definitions; On-line indicators. 3. Annex: Application of RBIs worldwide. (P.A.)

  12. Some computer simulations based on the linear relative risk model

    International Nuclear Information System (INIS)

    Gilbert, E.S.

    1991-10-01

    This report presents the results of computer simulations designed to evaluate and compare the performance of the likelihood ratio statistic and the score statistic for making inferences about the linear relative risk mode. The work was motivated by data on workers exposed to low doses of radiation, and the report includes illustration of several procedures for obtaining confidence limits for the excess relative risk coefficient based on data from three studies of nuclear workers. The computer simulations indicate that with small sample sizes and highly skewed dose distributions, asymptotic approximations to the score statistic or to the likelihood ratio statistic may not be adequate. For testing the null hypothesis that the excess relative risk is equal to zero, the asymptotic approximation to the likelihood ratio statistic was adequate, but use of the asymptotic approximation to the score statistic rejected the null hypothesis too often. Frequently the likelihood was maximized at the lower constraint, and when this occurred, the asymptotic approximations for the likelihood ratio and score statistics did not perform well in obtaining upper confidence limits. The score statistic and likelihood ratio statistics were found to perform comparably in terms of power and width of the confidence limits. It is recommended that with modest sample sizes, confidence limits be obtained using computer simulations based on the score statistic. Although nuclear worker studies are emphasized in this report, its results are relevant for any study investigating linear dose-response functions with highly skewed exposure distributions. 22 refs., 14 tabs

  13. Handbook of methods for risk-based analysis of technical specification requirements

    International Nuclear Information System (INIS)

    Samanta, P.K.; Vesely, W.E.

    1994-01-01

    Technical Specifications (TS) requirements for nuclear power plants define the Limiting Conditions for Operation (LCOs) and Surveillance Requirements (SRs) to assure safety during operation. In general, these requirements were based on deterministic analysis and engineering judgments. Experiences with plant operation indicate that some elements of the requirements are unnecessarily restrictive, while others may not be conducive to safety. Improvements in these requirements are facilitated by the availability of plant specific Probabilistic Safety Assessments (PSAs). The use of risk and reliability-based methods to improve TS requirements has gained wide interest because these methods can: Quantitatively evaluate the risk and justify changes based on objective risk arguments; Provide a defensible basis for these requirements for regulatory applications. The US NRC Office of Research is sponsoring research to develop systematic risk-based methods to improve various aspects of TS requirements. The handbook of methods, which is being prepared, summarizes such risk-based methods. The scope of the handbook includes reliability and risk-based methods for evaluating allowed outage times (AOTs), action statements requiring shutdown where shutdown risk may be substantial, surveillance test intervals (STIs), defenses against common-cause failures, managing plant configurations, and scheduling maintenances. For each topic, the handbook summarizes methods of analysis and data needs, outlines the insights to be gained, lists additional references, and presents examples of evaluations

  14. Handbook of methods for risk-based analysis of Technical Specification requirements

    International Nuclear Information System (INIS)

    Samanta, P.K.; Vesely, W.E.

    1993-01-01

    Technical Specifications (TS) requirements for nuclear power plants define the Limiting Conditions for Operation (LCOs) and Surveillance Requirements (SRs) to assure safety during operation. In general, these requirements were based on deterministic analysis and engineering judgments. Experiences with plant operation indicate that some elements of the requirements are unnecessarily restrictive, while others may not be conducive to safety. Improvements in these requirements are facilitated by the availability of plant specific Probabilistic Safety Assessments (PSAs). The use of risk and reliability-based methods to improve TS requirements has gained wide interest because these methods can: quantitatively evaluate the risk impact and justify changes based on objective risk arguments. Provide a defensible basis for these requirements for regulatory applications. The United States Nuclear Regulatory Commission (USNRC) Office of Research is sponsoring research to develop systematic risk-based methods to improve various aspects of TS requirements. The handbook of methods, which is being prepared, summarizes such risk-based methods. The scope of the handbook includes reliability and risk-based methods for evaluating allowed outage times (AOTs), action statements requiring shutdown where shutdown risk may be substantial, surveillance test intervals (STIs), defenses against common-cause failures, managing plant configurations, and scheduling maintenances. For each topic, the handbook summarizes methods of analysis and data needs, outlines the insights to be gained, lists additional references, and presents examples of evaluations

  15. Finite element limit analysis based plastic limit pressure solutions for cracked pipes

    International Nuclear Information System (INIS)

    Shim, Do Jun; Huh, Nam Su; Kim, Yun Jae; Kim, Young Jin

    2002-01-01

    Based on detailed FE limit analyses, the present paper provides tractable approximations for plastic limit pressure solutions for axial through-wall cracked pipe; axial (inner) surface cracked pipe; circumferential through-wall cracked pipe; and circumferential (inner) surface cracked pipe. Comparisons with existing analytical and empirical solutions show a large discrepancy in circumferential short through-wall cracks and in surface cracks (both axial and circumferential). Being based on detailed 3-D FE limit analysis, the present solutions are believed to be the most accurate, and thus to be valuable information not only for plastic collapse analysis of pressurised piping but also for estimating non-linear fracture mechanics parameters based on the reference stress approach

  16. Risky Information: Social Limits to Risk Management

    NARCIS (Netherlands)

    P. Mascini (Peter)

    1998-01-01

    textabstractThis article demonstrates that systematic biases occur in (near-)accident reporting. This conclusion is based on a quantitative document analysis of 208 reports recently written by employees of an industrial company. The effectiveness of accident reporting, as an instrument for risk

  17. 75 FR 50936 - Loan Policies and Operations; Lending and Leasing Limits and Risk Management

    Science.gov (United States)

    2010-08-18

    ...-AC60 Loan Policies and Operations; Lending and Leasing Limits and Risk Management AGENCY: Farm Credit... sound operation of System institutions by strengthening their risk management practices and abilities to... the establishment of consistent, uniform and prudent concentration risk management policies by System...

  18. Security breaches: tips for assessing and limiting your risks.

    Science.gov (United States)

    Coons, Leeanne R

    2011-01-01

    As part of their compliance planning, medical practices should undergo a risk assessment to determine any vulnerability within the practice relative to security breaches. Practices should also implement safeguards to limit their risks. Such safeguards include facility access controls, information and electronic media management, use of business associate agreements, and education and enforcement. Implementation of specific policies and procedures to address security incidents is another critical step that medical practices should take as part of their security incident prevention plan. Medical practices should not only develop policies and procedures to prevent, detect, contain, and correct security violations, but should make sure that such policies and procedures are actually implemented in their everyday operations.

  19. Risk factors for persistent airflow limitation: Analysis of 306 patients with asthma

    OpenAIRE

    Wang, Lingcheng; Gao, Shuncui; Zhu, Wei; Su, Jun

    2014-01-01

    Objectives : To determine the risk factors associated with persistent airflow limitation in patients with asthma. Method s: This study was designed and carried out in the department of respiratory medicine, fourth People?s Hospital of Jinan City, Shandong province, China between Jan 2012 and Dec 2012. Three hundred and six asthma patients participating in the study were divided into persistent airflow limitation group (PAFL) and no persistent airflow limitation group (NPAFL). The patients par...

  20. An Integrated Risk Index Model Based on Hierarchical Fuzzy Logic for Underground Risk Assessment

    Directory of Open Access Journals (Sweden)

    Muhammad Fayaz

    2017-10-01

    Full Text Available Available space in congested cities is getting scarce due to growing urbanization in the recent past. The utilization of underground space is considered as a solution to the limited space in smart cities. The numbers of underground facilities are growing day by day in the developing world. Typical underground facilities include the transit subway, parking lots, electric lines, water supply and sewer lines. The likelihood of the occurrence of accidents due to underground facilities is a random phenomenon. To avoid any accidental loss, a risk assessment method is required to conduct the continuous risk assessment and report any abnormality before it happens. In this paper, we have proposed a hierarchical fuzzy inference based model for under-ground risk assessment. The proposed hierarchical fuzzy inference architecture reduces the total number of rules from the rule base. Rule reduction is important because the curse of dimensionality damages the transparency and interpretation as it is very tough to understand and justify hundreds or thousands of fuzzy rules. The computation time also increases as rules increase. The proposed model takes 175 rules having eight input parameters to compute the risk index, and the conventional fuzzy logic requires 390,625 rules, having the same number of input parameters to compute risk index. Hence, the proposed model significantly reduces the curse of dimensionality. Rule design for fuzzy logic is also a tedious task. In this paper, we have also introduced new rule schemes, namely maximum rule-based and average rule-based; both schemes can be used interchangeably according to the logic needed for rule design. The experimental results show that the proposed method is a virtuous choice for risk index calculation where the numbers of variables are greater.

  1. Risk-based configuration control

    International Nuclear Information System (INIS)

    Szikszai, T.

    1997-01-01

    The presentation discusses the following issues: The Configuration Control; The Risk-based Configuration Control (during power operation mode, and during shutdown mode). PSA requirements. Use of Risk-based Configuration Control System. Configuration Management (basic elements, benefits, information requirements)

  2. A risk modelling approach for setting microbiological limits using enterococci as indicator for growth potential of Salmonella in pork

    DEFF Research Database (Denmark)

    Bollerslev, Anne Mette; Nauta, Maarten; Hansen, Tina Beck

    2017-01-01

    Microbiological limits are widely used in food processing as an aid to reduce the exposure to hazardous microorganisms for the consumers. However, in pork, the prevalence and concentrations of Salmonella are generally low and microbiological limits are not considered an efficient tool to support...... for this purpose includes the dose-response relationship for Salmonella and a reduction factor to account for preparation of the fresh pork. By use of the risk model, it was estimated that the majority of salmonellosis cases, caused by the consumption of pork in Denmark, is caused by the small fraction of pork...... products that has enterococci concentrations above 5. log. CFU/g. This illustrates that our approach can be used to evaluate the potential effect of different microbiological limits and therefore, the perspective of this novel approach is that it can be used for definition of a risk-based microbiological...

  3. A scenario-based procedure for seismic risk analysis

    International Nuclear Information System (INIS)

    Kluegel, J.-U.; Mualchin, L.; Panza, G.F.

    2006-12-01

    A new methodology for seismic risk analysis based on probabilistic interpretation of deterministic or scenario-based hazard analysis, in full compliance with the likelihood principle and therefore meeting the requirements of modern risk analysis, has been developed. The proposed methodology can easily be adjusted to deliver its output in a format required for safety analysts and civil engineers. The scenario-based approach allows the incorporation of all available information collected in a geological, seismotectonic and geotechnical database of the site of interest as well as advanced physical modelling techniques to provide a reliable and robust deterministic design basis for civil infrastructures. The robustness of this approach is of special importance for critical infrastructures. At the same time a scenario-based seismic hazard analysis allows the development of the required input for probabilistic risk assessment (PRA) as required by safety analysts and insurance companies. The scenario-based approach removes the ambiguity in the results of probabilistic seismic hazard analysis (PSHA) which relies on the projections of Gutenberg-Richter (G-R) equation. The problems in the validity of G-R projections, because of incomplete to total absence of data for making the projections, are still unresolved. Consequently, the information from G-R must not be used in decisions for design of critical structures or critical elements in a structure. The scenario-based methodology is strictly based on observable facts and data and complemented by physical modelling techniques, which can be submitted to a formalised validation process. By means of sensitivity analysis, knowledge gaps related to lack of data can be dealt with easily, due to the limited amount of scenarios to be investigated. The proposed seismic risk analysis can be used with confidence for planning, insurance and engineering applications. (author)

  4. Potential Occupational Exposures and Health Risks Associated with Biomass-Based Power Generation

    Science.gov (United States)

    Rohr, Annette C.; Campleman, Sharan L.; Long, Christopher M.; Peterson, Michael K.; Weatherstone, Susan; Quick, Will; Lewis, Ari

    2015-01-01

    Biomass is increasingly being used for power generation; however, assessment of potential occupational health and safety (OH&S) concerns related to usage of biomass fuels in combustion-based generation remains limited. We reviewed the available literature on known and potential OH&S issues associated with biomass-based fuel usage for electricity generation at the utility scale. We considered three potential exposure scenarios—pre-combustion exposure to material associated with the fuel, exposure to combustion products, and post-combustion exposure to ash and residues. Testing of dust, fungal and bacterial levels at two power stations was also undertaken. Results indicated that dust concentrations within biomass plants can be extremely variable, with peak levels in some areas exceeding occupational exposure limits for wood dust and general inhalable dust. Fungal spore types, identified as common environmental species, were higher than in outdoor air. Our review suggests that pre-combustion risks, including bioaerosols and biogenic organics, should be considered further. Combustion and post-combustion risks appear similar to current fossil-based combustion. In light of limited available information, additional studies at power plants utilizing a variety of technologies and biomass fuels are recommended. PMID:26206568

  5. Potential Occupational Exposures and Health Risks Associated with Biomass-Based Power Generation

    Directory of Open Access Journals (Sweden)

    Annette C. Rohr

    2015-07-01

    Full Text Available Biomass is increasingly being used for power generation; however, assessment of potential occupational health and safety (OH&S concerns related to usage of biomass fuels in combustion-based generation remains limited. We reviewed the available literature on known and potential OH&S issues associated with biomass-based fuel usage for electricity generation at the utility scale. We considered three potential exposure scenarios—pre-combustion exposure to material associated with the fuel, exposure to combustion products, and post-combustion exposure to ash and residues. Testing of dust, fungal and bacterial levels at two power stations was also undertaken. Results indicated that dust concentrations within biomass plants can be extremely variable, with peak levels in some areas exceeding occupational exposure limits for wood dust and general inhalable dust. Fungal spore types, identified as common environmental species, were higher than in outdoor air. Our review suggests that pre-combustion risks, including bioaerosols and biogenic organics, should be considered further. Combustion and post-combustion risks appear similar to current fossil-based combustion. In light of limited available information, additional studies at power plants utilizing a variety of technologies and biomass fuels are recommended.

  6. The nutritional limitations of plant-based beverages in infancy and childhood.

    Science.gov (United States)

    Vitoria, Isidro

    2017-10-24

    Breastfeeding, infant formula and cow's milk are basic foods in infant nutrition. However, they are being increasingly replaced either totally or partially by plant-based beverages.The composition of 164 plant-based beverages available in Spain was reviewed based on the nutritional labeling of the package and the manufacturers' webpages. This was compared to the composition of cow's milk and infant formula. In addition, the nutritional disease associated with consumption of plant-based beverages in infants and children was reviewed by means of a literature search in Medline and Embase since 1990 based on the key words "plant-based beverages" or "rice beverages" or "almond beverages" or "soy beverages" and "infant" or "child".The nutritional composition of 54 soy beverages, 24 rice beverages, 22 almond beverages, 31 oat beverages, 6 coconut beverages, 12 miscellaneous beverages and 15 mixed beverages was described. At least 30 cases of nutritional disease in children associated with nearly exclusive consumption of plant-based beverages have been published. A characteristic association has been observed between soy beverage and rickets, rice beverage and kwashiorkor, and almond-based beverage and metabolic alkalosis.The nutritional quality of plant-based beverages is lower than that of cow's milk and infant formula, therefore they are not a nutritional alternative. Predominant or exclusive use of these beverages in infant feeding can lead to serious nutritional risks. In the case of nonexclusive feeding with these beverages, the pediatrician should be aware of the nutritional risks and limitations of these beverages in order to complement their deficiencies with other foods.

  7. Risk-based regulation: Challenges and opportunities

    International Nuclear Information System (INIS)

    Bari, R.A.

    1995-01-01

    Over the last twenty years, man has witnessed a gradual but steady movement toward increased usage of risk-based methods and results in the regulatory process. The ''risk perspective'' as a supportive view to existing (non-risk-based or deterministic) information used in decision making has a firm foothold now in most countries that regulate nuclear power. Furthermore, in the areas outside the nuclear power field, such as health risk assessment, risk-based information is used increasingly to make decisions on potential impacts of chemical, biological, and radiological exposures. Some of the principal concepts and issues that are pertinent to risk-based regulation are reviewed. There is a growing interest in most countries in the use of risk-based methods and results to facilitate decision-making associated with regulatory processes. A summary is presented of the challenges and opportunities related to expanded use of risk-based regulation

  8. 76 FR 1889 - Risk-Based Capital Guidelines: Market Risk

    Science.gov (United States)

    2011-01-11

    ... ``three-pillar'' framework that includes (i) risk-based capital requirements for credit risk, market risk... incremental risk capital requirement to capture default and credit quality migration risk for non... (advanced approaches rules) (collectively, the credit risk capital rules) \\8\\ by requiring any bank subject...

  9. Managing long-term polycyclic aromatic hydrocarbon contaminated soils: a risk-based approach.

    Science.gov (United States)

    Duan, Luchun; Naidu, Ravi; Thavamani, Palanisami; Meaklim, Jean; Megharaj, Mallavarapu

    2015-06-01

    Polycyclic aromatic hydrocarbons (PAHs) are a family of contaminants that consist of two or more aromatic rings fused together. Soils contaminated with PAHs pose significant risk to human and ecological health. Over the last 50 years, significant research has been directed towards the cleanup of PAH-contaminated soils to background level. However, this achieved only limited success especially with high molecular weight compounds. Notably, during the last 5-10 years, the approach to remediate PAH-contaminated soils has changed considerably. A risk-based prioritization of remediation interventions has become a valuable step in the management of contaminated sites. The hydrophobicity of PAHs underlines that their phase distribution in soil is strongly influenced by factors such as soil properties and ageing of PAHs within the soil. A risk-based approach recognizes that exposure and environmental effects of PAHs are not directly related to the commonly measured total chemical concentration. Thus, a bioavailability-based assessment using a combination of chemical analysis with toxicological assays and nonexhaustive extraction technique would serve as a valuable tool in risk-based approach for remediation of PAH-contaminated soils. In this paper, the fate and availability of PAHs in contaminated soils and their relevance to risk-based management of long-term contaminated soils are reviewed. This review may serve as guidance for the use of site-specific risk-based management methods.

  10. Risk-based waste clearance concept for the D ampersand D program

    International Nuclear Information System (INIS)

    Chen, S.Y.; Bhattacharyya, S.K.

    1996-01-01

    Large amounts of radioactively contaminated wastes are expected to result from decontamination and decommissioning (D ampersand D) activities at nuclear facilities. Many of the waste materials, such as concrete rubble and scrap metals, are only slightly contaminated and can be recycled to minimize waste streams, resulting in substantial savings from reducing conventional waste disposal costs and recovering the values of the raw materials. For instance, a recent projection indicates that recycling an estimated 30 million tonnes of radioactive scrap metal (RSM) worldwide, having a corresponding recoverable value of about $10 billion to $20 billion, would avoid an estimated $5 billion in disposal costs. As an average heuristic, waste disposition constitutes ∼50% of total D ampersand D costs. There is thus a strong incentive to minimize the waste from D ampersand D activities. In the United States, no specific standards have been developed for the unrestricted release of bulk contaminated materials, although standards for the unrestricted release of radioactive surface contamination have existed for ∼20 yr. Materials are not commonly released because of the lack of risk-based justifications. Recent guidance from international bodies has established a basis for deriving risk-based release limits for radioactive materials. It is important, therefore, to evaluate the feasibility of recycling, because if it is feasible, risk-based release limits for the reusable materials will need to be established

  11. RiskREP: Risk-Based Security Requirements Elicitation and Prioritization

    OpenAIRE

    Herrmann, Andrea; Morali, A.; Etalle, Sandro; Wieringa, Roelf J.; Niedrite, Laila; Strazdina, Renate; Wangler, Benkt

    2011-01-01

    Companies are under pressure to be in control of their assets but at the same time they must operate as efficiently as possible. This means that they aim to implement “good-enough security‿ but need to be able to justify their security investment plans. In this paper, we present a Risk-Based Requirements Prioritization method (RiskREP) that extends misuse case-based methods with IT architecture based risk assessment and countermeasure definition and prioritization. Countermeasure prioritizati...

  12. A risk-informed basis for establishing non-fixed surface contamination limits for spent fuel transportation casks

    International Nuclear Information System (INIS)

    Rawl, R.R.; Eckerman, K.F.; Bogard, J.S.; Cook, J.R.

    2004-01-01

    The current limits for non-fixed contamination on packages used to transport radioactive materials were introduced in the 1961 edition of the International Atomic Energy Agency (IAEA) transport regulations and were based on radiation protection guidance and practices in use at that time. The limits were based on exposure scenarios leading to intakes of radionuclides by inhalation and external irradiation of the hands. These considerations are collectively referred to as the Fairbairn model. Although formulated over 40 years ago, the model remains unchanged and is still the basis of current regulatory-derived limits on package non-fixed surface contamination. There can also be doses that while not resulting directly from the contamination, are strongly influenced by and attributable to transport regulatory requirements for contamination control. For example, actions necessary to comply with the current derived limits for light-water-reactor (LWR) spent nuclear fuel (SNF) casks can result in significant external doses to workers. This is due to the relatively high radiation levels around the loaded casks, where workers must function during the measurement of contamination levels and while decontaminating the cask. In order to optimize the total dose received due to compliance with cask contamination levels, it is necessary to take into account all the doses that vary as a result of the regulatory limit. Limits for non-fixed surface contamination on spent fuel casks should be established by using a model that considers and optimizes the appropriate exposure scenarios both in the workplace and in the public environment. A risk-informed approach is needed to ensure optimal use of personnel and material resources for SNF-based packaging operations. This paper is a summary of a study sponsored by the US Nuclear Regulatory Commission and performed by Oak Ridge National Laboratory that examined the dose implications for removable surface contamination limits on spent fuel

  13. 12 CFR 567.6 - Risk-based capital credit risk-weight categories.

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 5 2010-01-01 2010-01-01 false Risk-based capital credit risk-weight... CAPITAL Regulatory Capital Requirements § 567.6 Risk-based capital credit risk-weight categories. (a) Risk...)(2) of this section), plus risk-weighted recourse obligations, direct credit substitutes, and certain...

  14. Generally applicable limits on intakes of uranium based on its chemical toxicity and the radiological significance of intakes at those limits

    International Nuclear Information System (INIS)

    Thorne, M C; Wilson, J

    2015-01-01

    Uranium is chemically toxic and radioactive, and both considerations have to be taken into account when limiting intakes of the element, in the context of both occupational and public exposures. Herein, the most recent information available on the chemical toxicity and biokinetics of uranium is used to propose new standards for limiting intakes of the element. The approach adopted allows coherent standards to be set for ingestion and inhalation of different chemical forms of the element by various age groups. It also allows coherent standards to be set for occupational and public exposures (including exposures of different age groups) and for various exposure regimes (including short-term and chronic exposures). The proposed standards are more restrictive than those used previously, but are less restrictive than the Minimal Risk Levels proposed recently by the US Agency for Toxic Substances and Disease Registry. Having developed a set of proposed limits based solely on chemical toxicity considerations, the radiological implications of exposure at those proposed limits are investigated for natural, depleted and enriched uranium. (paper)

  15. Entecavir treatment does not eliminate the risk of hepatocellular carcinoma in chronic hepatitis B: limited role for risk scores in Caucasians.

    Science.gov (United States)

    Arends, Pauline; Sonneveld, Milan J; Zoutendijk, Roeland; Carey, Ivana; Brown, Ashley; Fasano, Massimo; Mutimer, David; Deterding, Katja; Reijnders, Jurriën G P; Oo, Ye; Petersen, Jörg; van Bömmel, Florian; de Knegt, Robert J; Santantonio, Teresa; Berg, Thomas; Welzel, Tania M; Wedemeyer, Heiner; Buti, Maria; Pradat, Pierre; Zoulim, Fabien; Hansen, Bettina; Janssen, Harry L A

    2015-08-01

    Hepatocellular carcinoma (HCC) risk-scores may predict HCC in Asian entecavir (ETV)-treated patients. We aimed to study risk factors and performance of risk scores during ETV treatment in an ethnically diverse Western population. We studied all HBV monoinfected patients treated with ETV from 11 European referral centres within the VIRGIL Network. A total of 744 patients were included; 42% Caucasian, 29% Asian, 19% other, 10% unknown. At baseline, 164 patients (22%) had cirrhosis. During a median follow-up of 167 (IQR 82-212) weeks, 14 patients developed HCC of whom nine (64%) had cirrhosis at baseline. The 5-year cumulative incidence rate of HCC was 2.1% for non-cirrhotic and 10.9% for cirrhotic patients (peliminate the risk of HCC. Discriminatory performance of HCC risk scores was limited, particularly in Caucasians, at baseline and during therapy. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  16. Risk-based maintenance-Techniques and applications

    International Nuclear Information System (INIS)

    Arunraj, N.S.; Maiti, J.

    2007-01-01

    Plant and equipment, however well designed, will not remain safe or reliable if it is not maintained. The general objective of the maintenance process is to make use of the knowledge of failures and accidents to achieve the possible safety with the lowest possible cost. The concept of risk-based maintenance was developed to inspect the high-risk components usually with greater frequency and thoroughness and to maintain in a greater manner, to achieve tolerable risk criteria. Risk-based maintenance methodology provides a tool for maintenance planning and decision making to reduce the probability of failure of equipment and the consequences of failure. In this paper, the risk analysis and risk-based maintenance methodologies were identified and classified into suitable classes. The factors affecting the quality of risk analysis were identified and analyzed. The applications, input data and output data were studied to understand their functioning and efficiency. The review showed that there is no unique way to perform risk analysis and risk-based maintenance. The use of suitable techniques and methodologies, careful investigation during the risk analysis phase, and its detailed and structured results are necessary to make proper risk-based maintenance decisions

  17. The impact of high-risk drivers and benefits of limiting their driving degree of freedom.

    Science.gov (United States)

    Habtemichael, Filmon G; de Picado-Santos, Luis

    2013-11-01

    The perception of drivers regarding risk-taking behaviour is widely varied. High-risk drivers are the segment of drivers who are disproportionately represented in the majority of crashes. This study examines the typologies of drivers in risk-taking behaviour, the common high-risk driving errors (speeding, close following, abrupt lane-changing and impaired driving), their safety consequences and the technological (ITS) devices for their detection and correction. Limiting the driving degree of freedom of high-risk drivers is proposed and its benefits on safety as well as traffic operations are quantified using VISSIM microscopic traffic simulation at various proportions of high-risk drivers; namely, 4%, 8% and 12%. Assessment of the safety benefits was carried out by using the technique of simulated vehicle conflicts which was validated against historic crashes, and reduction in travel time was used to quantify the operational benefits. The findings imply that limiting the freedom of high-risk drivers resulted in a reduction of crashes by 12%, 21% and 27% in congested traffic conditions; 9%, 13% and 18% in lightly congested traffic conditions as well as 9%, 10% and 17% in non-congested traffic conditions for high-risk drivers in proportions of 4%, 8% and 12% respectively. Moreover, the surrogate safety measures indicated that there was a reduction in crash severity levels. The operational benefits amounted to savings of nearly 1% in travel time for all the proportions of high-risk drivers considered. The study concluded that limiting the freedom of high-risk drivers has safety and operational benefits; though there could be social, legal and institutional concerns for its practical implementation. Copyright © 2013 Elsevier Ltd. All rights reserved.

  18. Cool but counterproductive: interactive, Web-based risk communications can backfire.

    Science.gov (United States)

    Zikmund-Fisher, Brian J; Dickson, Mark; Witteman, Holly O

    2011-08-25

    Paper-based patient decision aids generally present risk information using numbers and/or static images. However, limited psychological research has suggested that when people interactively graph risk information, they process the statistics more actively, making the information more available for decision making. Such interactive tools could potentially be incorporated in a new generation of Web-based decision aids. The objective of our study was to investigate whether interactive graphics detailing the risk of side effects of two treatments improve knowledge and decision making over standard risk graphics. A total of 3371 members of a demographically diverse Internet panel viewed a hypothetical scenario about two hypothetical treatments for thyroid cancer. Each treatment had a chance of causing 1 of 2 side effects, but we randomly varied whether one treatment was better on both dimensions (strong dominance condition), slightly better on only one dimension (mild dominance condition), or better on one dimension but worse on the other (trade-off condition) than the other treatment. We also varied whether respondents passively viewed the risk information in static pictograph (icon array) images or actively manipulated the information by using interactive Flash-based animations of "fill-in-the-blank" pictographs. Our primary hypothesis was that active manipulation would increase respondents' ability to recognize dominance (when available) and choose the better treatment. The interactive risk graphic conditions had significantly worse survey completion rates (1110/1695, 65.5% vs 1316/1659, 79.3%, P graphic formats.

  19. How to evaluate the risks of exceeding limits: geostatistical models and their application to air pollution

    International Nuclear Information System (INIS)

    Fouquet, Ch. de; Deraisme, J.; Bobbia, M.

    2007-01-01

    Geo-statistics is increasingly applied to the study of environmental risks in a variety of sectors, especially in the fields of soil decontamination and the evaluation of the risks due to air pollution. Geo-statistics offers a rigorous stochastic modeling approach that makes it possible to answer questions expressed in terms of uncertainty and risk. This article focusses on nonlinear geo-statistical methods, based on the Gaussian random function model, whose essential properties are summarised. We use two examples to characterize situations where direct and thus rapid methods provide appropriate solutions and cases that inevitably require more laborious simulation techniques. Exposure of the population of the Rouen metropolitan area to the risk of NO 2 pollution is assessed by simulations, but the surface area where the pollution exceeds the threshold limit can be easily estimated with nonlinear conditional expectation techniques. A second example is used to discuss the bias introduced by direct simulation, here of a percentile of daily SO 2 concentration for one year in the city of Le Havre; an operational solution is proposed. (authors)

  20. Power MOSFET-diode-based limiter for high-frequency ultrasound systems.

    Science.gov (United States)

    Choi, Hojong; Kim, Min Gon; Cummins, Thomas M; Hwang, Jae Youn; Shung, K Kirk

    2014-10-01

    The purpose of the limiter circuits used in the ultrasound imaging systems is to pass low-voltage echo signals generated by ultrasonic transducers while preventing high-voltage short pulses transmitted by pulsers from damaging front-end circuits. Resistor-diode-based limiters (a 50 Ω resistor with a single cross-coupled diode pair) have been widely used in pulse-echo measurement and imaging system applications due to their low cost and simple architecture. However, resistor-diode-based limiters may not be suited for high-frequency ultrasound transducer applications since they produce large signal conduction losses at higher frequencies. Therefore, we propose a new limiter architecture utilizing power MOSFETs, which we call a power MOSFET-diode-based limiter. The performance of a power MOSFET-diode-based limiter was evaluated with respect to insertion loss (IL), total harmonic distortion (THD), and response time (RT). We compared these results with those of three other conventional limiter designs and showed that the power MOSFET-diode-based limiter offers the lowest IL (-1.33 dB) and fastest RT (0.10 µs) with the lowest suppressed output voltage (3.47 Vp-p) among all the limiters at 70 MHz. A pulse-echo test was performed to determine how the new limiter affected the sensitivity and bandwidth of the transducer. We found that the sensitivity and bandwidth of the transducer were 130% and 129% greater, respectively, when combined with the new power MOSFET-diode-based limiter versus the resistor-diode-based limiter. Therefore, these results demonstrate that the power MOSFET-diode-based limiter is capable of producing lower signal attenuation than the three conventional limiter designs at higher frequency operation. © The Author(s) 2014.

  1. Radiofrequency fields: Bases for exposure limits

    Energy Technology Data Exchange (ETDEWEB)

    Paolo Vecchia [Department of Technologies and Health National Institute of Health, Rome (Italy)

    2006-07-01

    Several biological effects have been reported at exposure levels below the threshold for thermal effects, but most of them require independent confirmation before being accepted as established. However, no seems to have relevant implications for human health. Precautionary measures should be based on a cost/benefit analysis, and be proportionate on one side to the risk they aim at preventing and on the other side to actions taken in other areas to prevent comparable risks. (N.C.)

  2. Radiofrequency fields: Bases for exposure limits

    International Nuclear Information System (INIS)

    Paolo Vecchia

    2006-01-01

    Several biological effects have been reported at exposure levels below the threshold for thermal effects, but most of them require independent confirmation before being accepted as established. However, no seems to have relevant implications for human health. Precautionary measures should be based on a cost/benefit analysis, and be proportionate on one side to the risk they aim at preventing and on the other side to actions taken in other areas to prevent comparable risks. (N.C.)

  3. Risk ratios for use in establishing dose limits for occupational exposure to radiation

    International Nuclear Information System (INIS)

    Metcalf, P.E.; Winkler, B.C.

    1980-01-01

    Dose limits for occupational exposure to radiation may be established by comparing the associated mortality risk with apparently accepted levels of industrial mortality risk due to conventional hazards. Average levels of industrial mortality risk rates are frequently quoted and used in such comparisons. However, within particular occupations or industries certain groups of workers will be exposed to higher levels of risk than the average, again an apparently accepted situation. A study has been made of the ratios of maximum to average industrial mortality risk currently experienced in some South African industries. Such a ratio may be used to assess the acceptability of maximum individual-to-average exposures in particular groups of exposed individuals. (author)

  4. Reliability analysis and risk-based methods for planning of operation & maintenance of offshore wind turbines

    DEFF Research Database (Denmark)

    Sørensen, John Dalsgaard

    2017-01-01

    for extreme and fatigue limit states are presented. Operation & Maintenance planning often follows corrective and preventive strategies based on information from condition monitoring and structural health monitoring systems. A reliability- and risk-based approach is presented where a life-cycle approach...

  5. Risk-based and deterministic regulation

    International Nuclear Information System (INIS)

    Fischer, L.E.; Brown, N.W.

    1995-07-01

    Both risk-based and deterministic methods are used for regulating the nuclear industry to protect the public safety and health from undue risk. The deterministic method is one where performance standards are specified for each kind of nuclear system or facility. The deterministic performance standards address normal operations and design basis events which include transient and accident conditions. The risk-based method uses probabilistic risk assessment methods to supplement the deterministic one by (1) addressing all possible events (including those beyond the design basis events), (2) using a systematic, logical process for identifying and evaluating accidents, and (3) considering alternative means to reduce accident frequency and/or consequences. Although both deterministic and risk-based methods have been successfully applied, there is need for a better understanding of their applications and supportive roles. This paper describes the relationship between the two methods and how they are used to develop and assess regulations in the nuclear industry. Preliminary guidance is suggested for determining the need for using risk based methods to supplement deterministic ones. However, it is recommended that more detailed guidance and criteria be developed for this purpose

  6. 76 FR 29992 - Loan Policies and Operations; Lending and Leasing Limits and Risk Management

    Science.gov (United States)

    2011-05-24

    ... FARM CREDIT ADMINISTRATION 12 CFR Part 614 RIN 3052-AC60 Loan Policies and Operations; Lending and Leasing Limits and Risk Management AGENCY: Farm Credit Administration. ACTION: Final rule. SUMMARY: The... (collectively loan) concentration risks. We expect this final rule will increase the safe and sound operation of...

  7. Limited risk assessment and some cost/benefit considerations for greater confinement disposal compared to shallow land burial

    International Nuclear Information System (INIS)

    Hunter, P.H.; Lester, D.H.; Robertson, L.D.; Spaeth, M.E.; Stoddard, J.A.; Dickman, P.T.

    1984-09-01

    A limited risk assessment and some cost/benefit considerations of greater confinement disposal (GCD) compared to shallow land burial (SLB) are presented. This study is limited to an analysis of the postclosure phase of hypothetical GCD and SLB facilities. Selected release scenarios are used which bound the range of risks to a maximally exposed individual and a hypothetical population. Based on the scenario assessments, GCD had a significant risk advantage over SLB for normal exposure pathways at both humid and arid sites, particularly for the human intrusion scenario. Since GCD costs are somewhat higher than SLB, it is necessary to weigh the higher costs of GCD against the higher risks of SLB. In this regard, GCD should be pursued as an alternative to SLB for certain types of low-level waste, and as an alternative to processing for wastes requiring improved stabilization or higher integrity packaging to be compatible with SLB. There are two reasons for this conclusion. First, GCD might diminish public apprehension regarding the disposal of wastes perceived to be too hazardous for SLB. Second, GCD may be a relatively cost-effective alternative to various stabilization and packaging schemes required to meet 10 CFR 61 near-surface requirements as well as being a cost-effective alternative to deep geologic disposal. Radionuclide transport through the biosphere and resultant dose consequences were determined using the RADTRAN radionuclide transport code. 19 references, 4 figures, 5 tables

  8. Recognition of risk situations based on endoscopic instrument tracking and knowledge based situation modeling

    Science.gov (United States)

    Speidel, Stefanie; Sudra, Gunther; Senemaud, Julien; Drentschew, Maximilian; Müller-Stich, Beat Peter; Gutt, Carsten; Dillmann, Rüdiger

    2008-03-01

    Minimally invasive surgery has gained significantly in importance over the last decade due to the numerous advantages on patient-side. The surgeon has to adapt special operation-techniques and deal with difficulties like the complex hand-eye coordination, limited field of view and restricted mobility. To alleviate these constraints we propose to enhance the surgeon's capabilities by providing a context-aware assistance using augmented reality (AR) techniques. In order to generate a context-aware assistance it is necessary to recognize the current state of the intervention using intraoperatively gained sensor data and a model of the surgical intervention. In this paper we present the recognition of risk situations, the system warns the surgeon if an instrument gets too close to a risk structure. The context-aware assistance system starts with an image-based analysis to retrieve information from the endoscopic images. This information is classified and a semantic description is generated. The description is used to recognize the current state and launch an appropriate AR visualization. In detail we present an automatic vision-based instrument tracking to obtain the positions of the instruments. Situation recognition is performed using a knowledge representation based on a description logic system. Two augmented reality visualization programs are realized to warn the surgeon if a risk situation occurs.

  9. Study on risk-based operation and maintenance using the living PSA system

    International Nuclear Information System (INIS)

    Kurisaka, K.

    2000-01-01

    The objective of this study is to contribute to an improvement of fast reactor plant operation and maintenance from the standpoint of risk assessment. An effort was made to analyze a relationship between the valve failure probability and the standby time based on the component reliability database and statistical analysis system (CORDS). According to the analysis result, the following issues were examined: the surveillance test interval (STI), timing and the allowable outage time (AOT) of redundant valve system in a fast reactor model plant. An examination was performed based on the failure probability non-linearly dependent on the standby time using the risk importance measures and technique to optimize the AOT which are incorporated in the living PSA system (LIPSAS). The case study showed that consideration of non-linear time trend of the failure probability made the recommended STI and AOT longer under the same risk limitation. It is recommended to apply the nonlinear expression of demand failure probability in estimating the STI and AOT based on the risk measures. (author)

  10. Risk-based analyses in support of California hazardous site remediation

    International Nuclear Information System (INIS)

    Ringland, J.T.

    1995-08-01

    The California Environmental Enterprise (CEE) is a joint program of the Department of Energy (DOE), Lawrence Livermore National Laboratory, Lawrence Berkeley Laboratory, and Sandia National Laboratories. Its goal is to make DOE laboratory expertise accessible to hazardous site cleanups in the state This support might involve working directly with parties responsible for individual cleanups or it might involve working with the California Environmental Protection Agency to develop tools that would be applicable across a broad range of sites. As part of its initial year's activities, the CEE supported a review to examine where laboratory risk and risk-based systems analysis capabilities might be most effectively applied. To this end, this study draws the following observations. The labs have a clear role in analyses supporting the demonstration and transfer of laboratory characterization or remediation technologies. The labs may have opportunities in developing broadly applicable analysis tools and computer codes for problems such as site characterization or efficient management of resources. Analysis at individual sites, separate from supporting lab technologies or prototyping general tools, may be appropriate only in limited circumstances. In any of these roles, the labs' capabilities extend beyond health risk assessment to the broader areas of risk management and risk-based systems analysis

  11. Quality expectations and tolerance limits of trial master files (TMF) - Developing a risk-based approach for quality assessments of TMFs.

    Science.gov (United States)

    Hecht, Arthur; Busch-Heidger, Barbara; Gertzen, Heiner; Pfister, Heike; Ruhfus, Birgit; Sanden, Per-Holger; Schmidt, Gabriele B

    2015-01-01

    This article addresses the question of when a trial master file (TMF) can be considered sufficiently accurate and complete: What attributes does the TMF need to have so that a clinical trial can be adequately reconstructed from documented data and procedures? Clinical trial sponsors face significant challenges in assembling the TMF, especially when dealing with large, international, multicenter studies; despite all newly introduced archiving techniques it is becoming more and more difficult to ensure that the TMF is complete. This is directly reflected in the number of inspection findings reported and published by the EMA in 2014. Based on quality risk management principles in clinical trials the authors defined the quality expectations for the different document types in a TMF and furthermore defined tolerance limits for missing documents. This publication provides guidance on what type of documents and processes are most important, and in consequence, indicates on which documents and processes trial team staff should focus in order to achieve a high-quality TMF. The members of this working group belong to the CQAG Group (Clinical Quality Assurance Germany) and are QA (quality assurance) experts (auditors or compliance functions) with long-term experience in the practical handling of TMFs.

  12. Risk-based methodology for USNRC inspections

    International Nuclear Information System (INIS)

    Wong, S.M.; Holahan, G.M.; Chung, J.W.; Johnson, M.R.

    1995-01-01

    This paper describes the development and trial applications of a risk-based methodology to enhance the inspection processes for US nuclear power plants. Objectives of risk-based methods to complement prescriptive engineering approaches in US Nuclear Regulatory Commission (USNRC) inspection programs are presented. Insights from time-dependent risk profiles of plant configurational from Individual Plant Evaluation (IPE) studies were integrated to develop a framework for optimizing inspection efforts in NRC regulatory initiatives. Lessons learned from NRC pilot applications of the risk-based methodology for evaluation of the effectiveness of operational risk management programs at US nuclear power plant sites are also discussed

  13. Risk-based SMA for Cubesats

    Science.gov (United States)

    Leitner, Jesse

    2016-01-01

    This presentation conveys an approach for risk-based safety and mission assurance applied to cubesats. This presentation accompanies a NASA Goddard standard in development that provides guidance for building a mission success plan for cubesats based on the risk tolerance and resources available.

  14. Currency risk management of non-financial public limited companies listed on WIG30 index

    Directory of Open Access Journals (Sweden)

    Alicja Mikołajewicz-Woźniak

    2013-12-01

    Full Text Available The objects of the study are selected aspects of currency risk management of nonfinancial public limited companies listed on WIG30 index. The estimation of net profit sensitivity to currencies exchange rates was used to determine importance of currency risk management for functioning of analyzed entities. The indication of the methods and tools used in currency risk management process became the basis for evaluation of taken actions. The determination of the relationship between hedging accounting and risk management results enabled the verification to what extent Polish companies exploit existing opportunities.

  15. Bayesian-network-based safety risk analysis in construction projects

    International Nuclear Information System (INIS)

    Zhang, Limao; Wu, Xianguo; Skibniewski, Miroslaw J.; Zhong, Jingbing; Lu, Yujie

    2014-01-01

    This paper presents a systemic decision support approach for safety risk analysis under uncertainty in tunnel construction. Fuzzy Bayesian Networks (FBN) is used to investigate causal relationships between tunnel-induced damage and its influential variables based upon the risk/hazard mechanism analysis. Aiming to overcome limitations on the current probability estimation, an expert confidence indicator is proposed to ensure the reliability of the surveyed data for fuzzy probability assessment of basic risk factors. A detailed fuzzy-based inference procedure is developed, which has a capacity of implementing deductive reasoning, sensitivity analysis and abductive reasoning. The “3σ criterion” is adopted to calculate the characteristic values of a triangular fuzzy number in the probability fuzzification process, and the α-weighted valuation method is adopted for defuzzification. The construction safety analysis progress is extended to the entire life cycle of risk-prone events, including the pre-accident, during-construction continuous and post-accident control. A typical hazard concerning the tunnel leakage in the construction of Wuhan Yangtze Metro Tunnel in China is presented as a case study, in order to verify the applicability of the proposed approach. The results demonstrate the feasibility of the proposed approach and its application potential. A comparison of advantages and disadvantages between FBN and fuzzy fault tree analysis (FFTA) as risk analysis tools is also conducted. The proposed approach can be used to provide guidelines for safety analysis and management in construction projects, and thus increase the likelihood of a successful project in a complex environment. - Highlights: • A systemic Bayesian network based approach for safety risk analysis is developed. • An expert confidence indicator for probability fuzzification is proposed. • Safety risk analysis progress is extended to entire life cycle of risk-prone events. • A typical

  16. Physics-based Entry, Descent and Landing Risk Model

    Science.gov (United States)

    Gee, Ken; Huynh, Loc C.; Manning, Ted

    2014-01-01

    A physics-based risk model was developed to assess the risk associated with thermal protection system failures during the entry, descent and landing phase of a manned spacecraft mission. In the model, entry trajectories were computed using a three-degree-of-freedom trajectory tool, the aerothermodynamic heating environment was computed using an engineering-level computational tool and the thermal response of the TPS material was modeled using a one-dimensional thermal response tool. The model was capable of modeling the effect of micrometeoroid and orbital debris impact damage on the TPS thermal response. A Monte Carlo analysis was used to determine the effects of uncertainties in the vehicle state at Entry Interface, aerothermodynamic heating and material properties on the performance of the TPS design. The failure criterion was set as a temperature limit at the bondline between the TPS and the underlying structure. Both direct computation and response surface approaches were used to compute the risk. The model was applied to a generic manned space capsule design. The effect of material property uncertainty and MMOD damage on risk of failure were analyzed. A comparison of the direct computation and response surface approach was undertaken.

  17. Work-Related Health Limitations, Education, and the Risk of Marital Disruption

    Science.gov (United States)

    Teachman, Jay

    2010-01-01

    Despite progress in identifying the covariates of divorce, there remain substantial gaps in the knowledge. One of these gaps is the relationship between health and risk of marital dissolution. I extend prior research by examining the linkages between work-related health limitations and divorce using 25 years of data (N = 7919) taken from the 1979…

  18. Current estimates of radiation risks and implications for dose limits

    International Nuclear Information System (INIS)

    Clarke, R.H.

    1989-01-01

    The publication of the 1988 report of UNSCEAR represents a major step forward in that there is an international consensus on the estimation of risk from exposure to ionising radiation. The estimates of fatal cancers in the UNSCEAR report are up to 4 times the values in the 1977 review. This paper will describe the reasons for the increase, the remaining uncertainties and the implications for dose limits in occupational and public exposure. (author)

  19. Use of limited data to construct Bayesian networks for probabilistic risk assessment.

    Energy Technology Data Exchange (ETDEWEB)

    Groth, Katrina M.; Swiler, Laura Painton

    2013-03-01

    Probabilistic Risk Assessment (PRA) is a fundamental part of safety/quality assurance for nuclear power and nuclear weapons. Traditional PRA very effectively models complex hardware system risks using binary probabilistic models. However, traditional PRA models are not flexible enough to accommodate non-binary soft-causal factors, such as digital instrumentation&control, passive components, aging, common cause failure, and human errors. Bayesian Networks offer the opportunity to incorporate these risks into the PRA framework. This report describes the results of an early career LDRD project titled %E2%80%9CUse of Limited Data to Construct Bayesian Networks for Probabilistic Risk Assessment%E2%80%9D. The goal of the work was to establish the capability to develop Bayesian Networks from sparse data, and to demonstrate this capability by producing a data-informed Bayesian Network for use in Human Reliability Analysis (HRA) as part of nuclear power plant Probabilistic Risk Assessment (PRA). This report summarizes the research goal and major products of the research.

  20. ℓ0 Gradient Minimization Based Image Reconstruction for Limited-Angle Computed Tomography.

    Directory of Open Access Journals (Sweden)

    Wei Yu

    Full Text Available In medical and industrial applications of computed tomography (CT imaging, limited by the scanning environment and the risk of excessive X-ray radiation exposure imposed to the patients, reconstructing high quality CT images from limited projection data has become a hot topic. X-ray imaging in limited scanning angular range is an effective imaging modality to reduce the radiation dose to the patients. As the projection data available in this modality are incomplete, limited-angle CT image reconstruction is actually an ill-posed inverse problem. To solve the problem, image reconstructed by conventional filtered back projection (FBP algorithm frequently results in conspicuous streak artifacts and gradual changed artifacts nearby edges. Image reconstruction based on total variation minimization (TVM can significantly reduce streak artifacts in few-view CT, but it suffers from the gradual changed artifacts nearby edges in limited-angle CT. To suppress this kind of artifacts, we develop an image reconstruction algorithm based on ℓ0 gradient minimization for limited-angle CT in this paper. The ℓ0-norm of the image gradient is taken as the regularization function in the framework of developed reconstruction model. We transformed the optimization problem into a few optimization sub-problems and then, solved these sub-problems in the manner of alternating iteration. Numerical experiments are performed to validate the efficiency and the feasibility of the developed algorithm. From the statistical analysis results of the performance evaluations peak signal-to-noise ratio (PSNR and normalized root mean square distance (NRMSD, it shows that there are significant statistical differences between different algorithms from different scanning angular ranges (p<0.0001. From the experimental results, it also indicates that the developed algorithm outperforms classical reconstruction algorithms in suppressing the streak artifacts and the gradual changed

  1. The Global Landscape of Occupational Exposure Limits--Implementation of Harmonization Principles to Guide Limit Selection.

    Science.gov (United States)

    Deveau, M; Chen, C-P; Johanson, G; Krewski, D; Maier, A; Niven, K J; Ripple, S; Schulte, P A; Silk, J; Urbanus, J H; Zalk, D M; Niemeier, R W

    2015-01-01

    Occupational exposure limits (OELs) serve as health-based benchmarks against which measured or estimated workplace exposures can be compared. In the years since the introduction of OELs to public health practice, both developed and developing countries have established processes for deriving, setting, and using OELs to protect workers exposed to hazardous chemicals. These processes vary widely, however, and have thus resulted in a confusing international landscape for identifying and applying such limits in workplaces. The occupational hygienist will encounter significant overlap in coverage among organizations for many chemicals, while other important chemicals have OELs developed by few, if any, organizations. Where multiple organizations have published an OEL, the derived value often varies considerably-reflecting differences in both risk policy and risk assessment methodology as well as access to available pertinent data. This article explores the underlying reasons for variability in OELs, and recommends the harmonization of risk-based methods used by OEL-deriving organizations. A framework is also proposed for the identification and systematic evaluation of OEL resources, which occupational hygienists can use to support risk characterization and risk management decisions in situations where multiple potentially relevant OELs exist.

  2. Potentials and limitations of hazard indices for the determination of risk potentials of disposed toxic wastes

    International Nuclear Information System (INIS)

    Kirchner, Gerald

    1989-01-01

    Hazard indices are often used for the determination of risk potentials arising from the geological disposal of toxic wastes. They are based on simplified models for the calculation of potential health effects caused by the wastes. The attractiveness of hazard indices lies in their simplicity which nevertheless results in reliable data on necessary isolation times and the most toxic nuclides of a waste. They also make possible comparisons of the potential risks of different wastes. After a discussion of the processes that control the behavior of toxic wastes in the environment after a failure of the geological barriers, a new hazard index is presented. Originally developed for nuclear wastes, it is the first which involves the joint consideration of the composition of a waste, the probability for transport of waste nuclides to man, their toxicity, and the time-dependent changes of the risk potentials which are caused by radioactive buildup and decay processes after the waste has entered the biosphere. The new hazard index makes possible the calculation of risk potentials at a given time of release and time period of concern thereafter. Sample calculations for different nuclear wastes show the importance of the model improvements on resulting time-dependent risk potentials. Applicability of the new hazard index to non-nuclear wastes is described. Potentials and limitations of comparative risk assessments using hazard indices are discussed. (author)

  3. Risk Management Practices in Islamic Bank: A Case Study of Islami Bank Bangladesh Limited

    OpenAIRE

    Uddin, Md Akther

    2015-01-01

    Islamic banking industry has been growing rapidly for last three decades. As risk is inherent in banking business it is necessary to develop a comprehensive risk management framework and process. In this paper, a humble attempt has been made to study and analyze risk management practices of Islami Bank Bangladesh Limited (IBBL), one of the leading Islamic banks in Bangaladesh. Annual reports of IBBL and 7 other full-fledged Islamic banks, Bangladesh Bank, the central bank of Bangladesh, publi...

  4. Threshold limit values, permissible exposure limits, and feasibility: The bases for exposure limits in the United States

    International Nuclear Information System (INIS)

    Rappaport, S.M.

    1993-01-01

    The development of exposure limits in the United States has always relied heavily upon the threshold limit values (TLVs) developed by the American Conference of Governmental Industrial Hygienists (ACGIH). In fact, the TLVs were adopted as official exposure limits by the Occupational Safety and Health Administration (OSHA) in 1972 and 1989. Given the continuing importance of the ACGIH limits, this paper compares the basis of the TLVs with that employed by OSHA de novo in its 12 new permissible exposure limits (PELs). Using benzene as an example, it is shown that OSHA's new PELs have been established following a rigorous assessment of the inherent risks and the feasibility of instituting the limit. The TLVs, on the other hand, have been developed by ad hoc procedures and appear to have traditionally reflected levels thought to be achievable at the time. However, this might be changing. Analysis of the historical reductions of TLVs, for 27 substances on the 1991-1992 list of intended changes, indicates smaller reductions in the past (median reduction of 2.0-2.5-fold between 1946 and 1988) compared to those currently being observed (median reduction of 7.5-fold between 1989 and 1991). Further analysis suggests a more aggressive policy of the ACGIH regarding TLVs for carcinogens but not for substances that produce effects other than cancer. Regardless of whether the basis of the TLVs has changed recently, it would take a relatively long time for the impact of any change to be felt, since the median age of the 1991-1992 TLVs is 16.5 years, and 75% of these limits are more than 10 years old. The implications of OSHA's continued reliance on the TLVs as a means of updating its PELs are discussed, and four alternatives are presented to the ACGIH regarding the future of its activities related to exposure limits. It is concluded that new mechanisms are needed for OSHA to update its PELs in a timely fashion so that the TLVs will not be adopted by default in the future

  5. HOW INTERNAL RISK - BASED AUDIT APPRAISES THE EVALUATION OF RISKS MANAGEMENT

    Directory of Open Access Journals (Sweden)

    N. Dorosh

    2017-09-01

    Full Text Available The article deals with the nature and function of the internal risk-based audit process approach to create patterns of risks and methods of evaluation. Deals with the relationship between the level of maturity of the risk of the company and the method of risk-based internal audit. it was emphasized that internal auditing provides an independent and objective opinion to an organization’s management as to whether its risks are being managed to acceptable levels.

  6. Scrape-off layer based modelling of the density limit in beryllated JET limiter discharges

    International Nuclear Information System (INIS)

    Borrass, K.; Campbell, D.J.; Clement, S.; Vlases, G.C.

    1993-01-01

    The paper gives a scrape-off layer based interpretation of the density limit in beryllated JET limiter discharges. In these discharges, JET edge parameters show a complicated time evolution as the density limit is approached and the limit is manifested as a non-disruptive density maximum which cannot be exceeded by enhanced gas puffing. The occurrence of Marfes, the manner of density control and details of recycling are essential elements of the interpretation. Scalings for the maximum density are given and compared with JET data. The relation to disruptive density limits, previously observed in JET carbon limiter discharges, and to density limits in divertor discharges is discussed. (author). 18 refs, 10 figs, 1 tab

  7. Comparative risk-benefit-cost effectiveness in nuclear and alternate power sources: methodology, perspective, limitations

    International Nuclear Information System (INIS)

    Vinck, W.; Van Reijen, G.; Maurer, H.; Volta, G.

    1980-01-01

    A critical survey is given of the use of quantitative risk assessment in defining acceptable limits of safety and of its use together with cost-benefit analyses for decision making. The paper indicates uncertainties and even unknowns in risk assessment in particular if the whole fuel cycle for energy production is considered. It is made clear that for decisions on acceptance of risk also the risk perception factor must be considered. A difficult issue here is the potential for low-probability/large consequence accidents. Examples are given, suggestions for improvement are made and perspectives are outlined

  8. Comparison of Thoracic Injury Risk in Frontal Car Crashes for Occupant Restrained without Belt Load Limiters and Those Restrained with 6 kN and 4 kN Belt Load Limiters.

    Science.gov (United States)

    Foret-Bruno, J Y; Trosseille, X; Page, Y; Huère, J F; Le Coz, J Y; Bendjellal, F; Diboine, A; Phalempin, T; Villeforceix, D; Baudrit, P; Guillemot, H; Coltat, J C

    2001-11-01

    , and 149 involved cars equipped with the 4 kN load limiter. Based on this accident data, the study compares the thoracic injury risk for two occupant populations: belted occupants involved in accidents in which the vehicle was not equipped with a load limiter (378 cases with pyrotechnic pretensioners), and belted occupants involved in accidents in which the vehicles were equipped with 4 or 6 kN load limiters and pyrotechnic pretensioners (347 cases). One observes that a 4 kN load limitation results in a very important reduction of thoracic injury risk for all AIS levels, compared to others samples. 50 to 60% reduction for AIS 2+ was observed, as well as 75 to 85% for AIS 3+. The complete absence of AIS 4+ with a 4 kN load limiter must be stressed, though it remains more than 8% for the other samples (no limiter and 6 kN limiter).

  9. Balancing public health and resource limitations: A role for ethical low-level risk communication

    International Nuclear Information System (INIS)

    McGinn, R.E.

    1991-01-01

    Recognition of the pervasiveness of risk in everyday life in modern industrial society has elicited calls for greater efforts to protect individual and public health. Yet, it is increasingly clear that decisions to do so must often be made in the context of significant limits in the amounts of financial resources available for achieving that protection. Achieving risk-free work, residential, and community environments may be so expensive as to render a private business unit uncompetitive or as to divert resources from or prelude commencing with other governmental projects with equal or greater health benefit potential. Ethical low-level risk communication (LLRC) is something risk-generating entities are morally obligated to do. However, such communication also offers important opportunities for such entities to move toward achieving better balances between health and the costs of protecting it. In this paper, the authors elaborate on several features of an ethically ideal LLRC process, focusing on those with aspects they hope are not obvious or common knowledge. In discussing these features, they provide examples of conflicts between health risks and resource limits at the level of the individual private firm, the local community, or the national government, such that LLRC with the feature in question provides an opportunity for mitigating or at least clarifying the conflict in question

  10. RISK LOAN PORTFOLIO OPTIMIZATION MODEL BASED ON CVAR RISK MEASURE

    Directory of Open Access Journals (Sweden)

    Ming-Chang LEE

    2015-07-01

    Full Text Available In order to achieve commercial banks liquidity, safety and profitability objective requirements, loan portfolio risk analysis based optimization decisions are rational allocation of assets.  The risk analysis and asset allocation are the key technology of banking and risk management.  The aim of this paper, build a loan portfolio optimization model based on risk analysis.  Loan portfolio rate of return by using Value-at-Risk (VaR and Conditional Value-at-Risk (CVaR constraint optimization decision model reflects the bank's risk tolerance, and the potential loss of direct control of the bank.  In this paper, it analyze a general risk management model applied to portfolio problems with VaR and CVaR risk measures by using Using the Lagrangian Algorithm.  This paper solves the highly difficult problem by matrix operation method.  Therefore, the combination of this paper is easy understanding the portfolio problems with VaR and CVaR risk model is a hyperbola in mean-standard deviation space.  It is easy calculation in proposed method.

  11. The revision of dose limits for exposure to ionizing radiation

    International Nuclear Information System (INIS)

    Hughes, D.

    1990-01-01

    The paper reviews the current dose limits for exposure to ionizing radiations and the risk factors on which they are based, and summarizes the revised risk factors and the draft proposals for new dose limits published by the International Commission on Radiological Protection. (author)

  12. Risk-based inspection of nuclear power plants

    International Nuclear Information System (INIS)

    Masopust, R.

    1995-01-01

    A multidiscipline research programme was developed in the USA to establish risk-based inspections for NPP structures and equipment components. Based on this US research effort, the risk-based procedure for developing inspection guidelines for NPPs is described. The procedure includes the definition of systems, qualitative risk assessment, qualitative risk analysis and development of the inspection programme. The method, when adopted and modified, is recommended also for risk-based inspections of structures and equipment of WWER-type NPPs. A pilot application of the method to unit 1 of the Surry NPP is summarized. (Z.S.) 1 tab., 1 fig., 5 refs

  13. Model based climate information on drought risk in Africa

    Science.gov (United States)

    Calmanti, S.; Syroka, J.; Jones, C.; Carfagna, F.; Dell'Aquila, A.; Hoefsloot, P.; Kaffaf, S.; Nikulin, G.

    2012-04-01

    The United Nations World Food Programme (WFP) has embarked upon the endeavor of creating a sustainable Africa-wide natural disaster risk management system. A fundamental building block of this initiative is the setup of a drought impact modeling platform called Africa Risk-View that aims to quantify and monitor weather-related food security risk in Africa. The modeling approach is based the Water Requirement Satisfaction Index (WRSI), as the fundamental indicator of the performances of agriculture and uses historical records of food assistance operation to project future potential needs for livelihood protection. By using climate change scenarios as an input to Africa Risk-View it is possible, in principles, to evaluate the future impact of climate variability on critical issues such as food security and the overall performance of the envisaged risk management system. A necessary preliminary step to this challenging task is the exploration of the sources of uncertainties affecting the assessment based on modeled climate change scenarios. For this purpose, a limited set of climate models have been selected in order verify the relevance of using climate model output data with Africa Risk-View and to explore a minimal range of possible sources of uncertainty. This first evaluation exercise started before the setup of the CORDEX framework and has relied on model output available at the time. In particular only one regional downscaling was available for the entire African continent from the ENSEMBLES project. The analysis shows that current coarse resolution global climate models can not directly feed into the Africa RiskView risk-analysis tool. However, regional downscaling may help correcting the inherent biases observed in the datasets. Further analysis is performed by using the first data available under the CORDEX framework. In particular, we consider a set of simulation driven with boundary conditions from the reanalysis ERA-Interim to evaluate the skill drought

  14. Risk-based remediation: Approach and application

    International Nuclear Information System (INIS)

    Frishmuth, R.A.; Benson, L.A.

    1995-01-01

    The principle objective of remedial actions is to protect human health and the environment. Risk assessments are the only defensible tools available to demonstrate to the regulatory community and public that this objective can be achieved. Understanding the actual risks posed by site-related contamination is crucial to designing cost-effective remedial strategies. All to often remedial actions are overdesigned, resulting in little to no increase in risk reduction while increasing project cost. Risk-based remedial actions have recently been embraced by federal and state regulators, industry, government, the scientific community, and the public as a mechanism to implement rapid and cost-effective remedial actions. Emphasizing risk reduction, rather than adherence to ambiguous and generic standards, ensures that only remedial actions required to protect human health and the environment at a particular site are implemented. Two sites are presented as case studies on how risk-based approaches are being used to remediate two petroleum hydrocarbon contaminated sites. The sites are located at two US Air Force Bases, Wurtsmith Air Force Base (AFB) in Oscoda, Michigan and Malmstrom AFB in Great Falls, Montana

  15. Elderly benzodiazepine users at increased risk of activity limitations: influence of chronicity, indications, and duration of action--the three-city cohort.

    Science.gov (United States)

    Carrière, Isabelle; Mura, Thibault; Pérès, Karine; Norton, Joanna; Jaussent, Isabelle; Edjolo, Arlette; Rouaud, Olivier; Berr, Claudine; Ritchie, Karen; Ancelin, Marie Laure

    2015-08-01

    To examine the cross-sectional and longitudinal associations between benzodiazepine use and daily activity limitations, according to drug indications and duration of action. Prospective cohort study. Population-based three-city study. 6,600 participants aged 65 years and over included between 1999 and 2001 and followed after 2, 4, and 7 years. Benzodiazepine users were separated into hypnotic, short-acting anxiolytic, and long-acting anxiolytic users and compared with non users. Three outcomes were examined assessing restrictions in mobility, instrumental activities of daily living (IADLs) and social participation. In multivariate simple or mixed logistic models adjusted for sociodemographic variables, impairments and comorbidity, and for anxiety, insomnia, and depression, hypnotic benzodiazepines were moderately associated with mobility limitation prevalence and IADL limitation incidence. Short-acting and long-acting anxiolytics were associated with IADL limitation prevalence and with mobility limitation prevalence and incidence and long-acting anxiolytics were also associated with IADL limitation incidence. Chronic benzodiazepines users were at a marked risk of developing restrictions for the three outcomes; odds ratio: 1.71 (95% CI: 1.23-2.39) for mobility, 1.54 (95% CI: 1.14-2.10) for IADL, and 1.74 (95% CI: 1.23-2.47) for participation limitations. Benzodiazepine users are at increased risk of activity limitations regardless of the duration of action or indication. Chronic use of benzodiazepines should be avoided in order to extend disability-free survival. Copyright © 2015 American Association for Geriatric Psychiatry. Published by Elsevier Inc. All rights reserved.

  16. A risk-based approach to liquid effluent monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Hull, L.C.

    1995-10-01

    DOE Order 5400.1 identifies six objectives of a liquid effluent monitoring program. A strategy is proposed that meets these objective in one of two ways: (1) by showing that effluent concentrations are below concentration limits set by permits or are below concentrations that could cause environmental problems or (2) by showing that concentrations in effluent have not changed from a period when treatment processes were in control and there were no unplanned releases. The intensity of liquid effluent monitoring should be graded to the importance of the source being monitored. This can be accomplished by determining the risk posed by the source. A definition of risk is presented that defines risk in terms of the statistical probability of exceeding a release limit and the time available to recover from an exceedance of a release limit. Three examples are presented that show this approach to grading an effluent monitoring program can be implemented at the Idaho National Engineering Laboratory and will reduce monitoring requirements.

  17. A risk-based approach to liquid effluent monitoring

    International Nuclear Information System (INIS)

    Hull, L.C.

    1995-10-01

    DOE Order 5400.1 identifies six objectives of a liquid effluent monitoring program. A strategy is proposed that meets these objective in one of two ways: (1) by showing that effluent concentrations are below concentration limits set by permits or are below concentrations that could cause environmental problems or (2) by showing that concentrations in effluent have not changed from a period when treatment processes were in control and there were no unplanned releases. The intensity of liquid effluent monitoring should be graded to the importance of the source being monitored. This can be accomplished by determining the risk posed by the source. A definition of risk is presented that defines risk in terms of the statistical probability of exceeding a release limit and the time available to recover from an exceedance of a release limit. Three examples are presented that show this approach to grading an effluent monitoring program can be implemented at the Idaho National Engineering Laboratory and will reduce monitoring requirements

  18. Developing points-based risk-scoring systems in the presence of competing risks.

    Science.gov (United States)

    Austin, Peter C; Lee, Douglas S; D'Agostino, Ralph B; Fine, Jason P

    2016-09-30

    Predicting the occurrence of an adverse event over time is an important issue in clinical medicine. Clinical prediction models and associated points-based risk-scoring systems are popular statistical methods for summarizing the relationship between a multivariable set of patient risk factors and the risk of the occurrence of an adverse event. Points-based risk-scoring systems are popular amongst physicians as they permit a rapid assessment of patient risk without the use of computers or other electronic devices. The use of such points-based risk-scoring systems facilitates evidence-based clinical decision making. There is a growing interest in cause-specific mortality and in non-fatal outcomes. However, when considering these types of outcomes, one must account for competing risks whose occurrence precludes the occurrence of the event of interest. We describe how points-based risk-scoring systems can be developed in the presence of competing events. We illustrate the application of these methods by developing risk-scoring systems for predicting cardiovascular mortality in patients hospitalized with acute myocardial infarction. Code in the R statistical programming language is provided for the implementation of the described methods. © 2016 The Authors. Statistics in Medicine published by John Wiley & Sons Ltd. © 2016 The Authors. Statistics in Medicine published by John Wiley & Sons Ltd.

  19. Challenges in Risk Assessment: Quantitative Risk Assessment

    OpenAIRE

    Jacxsens, Liesbeth; Uyttendaele, Mieke; De Meulenaer, Bruno

    2016-01-01

    The process of risk analysis consists out of three components, risk assessment, risk management and risk communication. These components are internationally well spread by Codex Alimentarius Commission as being the basis for setting science based standards, criteria on food safety hazards, e.g. setting maximum limits of mycotoxins in foodstuffs. However, the technical component risk assessment is hard to elaborate and to understand. Key in a risk assessment is the translation of biological or...

  20. RISK MANAGEMENT AUTOMATION OF SOFTWARE PROJECTS BASED ОN FUZZY INFERENCE

    Directory of Open Access Journals (Sweden)

    T. M. Zubkova

    2015-09-01

    Full Text Available Application suitability for one of the intelligent methods for risk management of software projects has been shown based on the review of existing algorithms for fuzzy inference in the field of applied problems. Information sources in the management of software projects are analyzed; major and minor risks are highlighted. The most critical parameters have been singled out giving the possibility to estimate the occurrence of an adverse situations (project duration, the frequency of customer’s requirements changing, work deadlines, experience of developers’ participation in such projects and others.. The method of qualitative fuzzy description based on fuzzy logic has been developed for analysis of these parameters. Evaluation of possible situations and knowledge base formation rely on a survey of experts. The main limitations of existing automated systems have been identified in relation to their applicability to risk management in the software design. Theoretical research set the stage for software system that makes it possible to automate the risk management process for software projects. The developed software system automates the process of fuzzy inference in the following stages: rule base formation of the fuzzy inference systems, fuzzification of input variables, aggregation of sub-conditions, activation and accumulation of conclusions for fuzzy production rules, variables defuzzification. The result of risk management automation process in the software design is their quantitative and qualitative assessment and expert advice for their minimization. Practical significance of the work lies in the fact that implementation of the developed automated system gives the possibility for performance improvement of software projects.

  1. Risk analysis in cattle fattening in North West Ethiopia: Empirical evidence form two limit Tobit model

    Directory of Open Access Journals (Sweden)

    Habtamu Yesigat Ayenew

    2012-09-01

    Full Text Available Resource allocation is a point of concern in small to large farms and is generally argued that small farmers in developing countries are “poor but efficient”, trying to allocate the limited resources to unlimited desires efficiently in the given production system in the light of their life-long experiences. The issue of market orientation in cattle fattening is basically challenged with the risks and uncertainties in the production and the market. Data were collected from 112 purposively selected fattening operator farmers from 3 districts and 6 peasant associations to see the risks. The data were analyzed through both descriptive and econometric statistical tools using STATA. Only about 13% of the respondents have participated in the farm business with own capital and the vast majority borrowed from Amhara Credit and Saving Association (ACSI through their cooperatives. It is found that production risks are limited while economic and market related risks play vital role in the farm operation. Duration of stay of the cattle, land holding of the household, distance to the development agent’s office and age of the household head increase the risk averse nature of the household and limit their participation in export market. In the other hand, frequency of fattening enhances the risk taking character of the households and their participation in the export of cattle. It is vital to enhance the institutional support from the public to enhance the gain from the fattening activity and market orientation of farming.

  2. Nuclear insurance risk assessment using risk-based methodology

    International Nuclear Information System (INIS)

    Wendland, W.G.

    1992-01-01

    This paper presents American Nuclear Insurers' (ANI's) and Mutual Atomic Energy Liability Underwriters' (MAELU's) process and experience for conducting nuclear insurance risk assessments using a risk-based methodology. The process is primarily qualitative and uses traditional insurance risk assessment methods and an approach developed under the auspices of the American Society of Mechanical Engineers (ASME) in which ANI/MAELU is an active sponsor. This process assists ANI's technical resources in identifying where to look for insurance risk in an industry in which insurance exposure tends to be dynamic and nonactuarial. The process is an evolving one that also seeks to minimize the impact on insureds while maintaining a mutually agreeable risk tolerance

  3. 13 CFR 120.1000 - Risk-Based Lender Oversight.

    Science.gov (United States)

    2010-01-01

    ... 13 Business Credit and Assistance 1 2010-01-01 2010-01-01 false Risk-Based Lender Oversight. 120.1000 Section 120.1000 Business Credit and Assistance SMALL BUSINESS ADMINISTRATION BUSINESS LOANS Risk-Based Lender Oversight Supervision § 120.1000 Risk-Based Lender Oversight. (a) Risk-Based Lender...

  4. Prioritization of pharmaceuticals based on risks to aquatic environments in Kazakhstan.

    Science.gov (United States)

    Aubakirova, Bakhyt; Beisenova, Raikhan; Boxall, Alistair Ba

    2017-09-01

    Over the last 20 years, there has been increasing interest in the occurrence, fate, effects, and risk of pharmaceuticals in the natural environment. However, we still have only limited or no data on ecotoxicological risks of many of the active pharmaceutical ingredients (APIs) currently in use. This is partly due to the fact that the environmental assessment of an API is an expensive, time-consuming, and complicated process. Prioritization methodologies, which aim to identify APIs of most concern in a particular situation, could therefore be invaluable in focusing experimental work on APIs that really matter. The majority of approaches for prioritizing APIs require annual pharmaceutical usage data. These methods cannot therefore be applied to countries, such as Kazakhstan, that have very limited data on API usage. The present paper therefore offers an approach for prioritizing APIs in surface waters in information-poor regions such as Kazakhstan. Initially data were collected on the number of products and active ingredients for different therapeutic classes in use in Kazakhstan and on the typical doses. These data were then used alongside simple exposure modeling approaches to estimate exposure indices for active ingredients (about 240 APIs) in surface waters in the country. Ecotoxicological effects data were obtained from the literature or predicted. Risk quotients were then calculated for each pharmaceutical based on the exposure and the substances were ranked in order of risk quotient. Highest exposure indices were obtained for benzylpenicillin, metronidazole, sulbactam, ceftriaxone, and sulfamethoxazole. The highest risk was estimated for amoxicillin, clarithromycin, azithromycin, ketoconazole, and benzylpenicillin. In the future, the approach could be employed in other regions where usage information is limited. Integr Environ Assess Manag 2017;13:832-839. © 2017 SETAC. © 2017 SETAC.

  5. Accounting for failure: risk-based regulation and the problems of ensuring healthcare quality in the NHS.

    Science.gov (United States)

    Beaussier, Anne-Laure; Demeritt, David; Griffiths, Alex; Rothstein, Henry

    2016-05-18

    In this paper, we examine why risk-based policy instruments have failed to improve the proportionality, effectiveness, and legitimacy of healthcare quality regulation in the National Health Service (NHS) in England. Rather than trying to prevent all possible harms, risk-based approaches promise to rationalise and manage the inevitable limits of what regulation can hope to achieve by focusing regulatory standard-setting and enforcement activity on the highest priority risks, as determined through formal assessments of their probability and consequences. As such, risk-based approaches have been enthusiastically adopted by healthcare quality regulators over the last decade. However, by drawing on historical policy analysis and in-depth interviews with 15 high-level UK informants in 2013-2015, we identify a series of practical problems in using risk-based policy instruments for defining, assessing, and ensuring compliance with healthcare quality standards. Based on our analysis, we go on to consider why, despite a succession of failures, healthcare regulators remain committed to developing and using risk-based approaches. We conclude by identifying several preconditions for successful risk-based regulation: goals must be clear and trade-offs between them amenable to agreement; regulators must be able to reliably assess the probability and consequences of adverse outcomes; regulators must have a range of enforcement tools that can be deployed in proportion to risk; and there must be political tolerance for adverse outcomes.

  6. Fall risk factors in community-dwelling elderly who receive Medicaid-supported home- and community-based care services.

    Science.gov (United States)

    Yamashita, Takashi; Jeon, Haesang; Bailer, A John; Nelson, Ian M; Mehdizadeh, Shahla

    2011-06-01

    This study identifies fall risk factors in an understudied population of older people who receive community-based care services. Data were collected from enrollees of Ohio's Medicaid home- and community-based waiver program (preadmission screening system providing options and resources today [PASSPORT]). A total of 23,182 participants receiving PASSPORT services in 2005/2006 was classified as fallers and nonfallers, and a variety of risk factors for falling was analyzed using logistic regressions. The following factors were identified as risk factors for falling: previous fall history, older age, White race, incontinence, higher number of medications, fewer numbers of activity of daily living limitations, unsteady gait, tremor, grasping strength, and absence of supervision. Identifying risk factors for the participants of a Medicaid home- and community-based waiver program are useful for a fall risk assessment, but it would be most helpful if the community-based care service programs incorporate measurements of known fall risk factors into their regular data collection, if not already included.

  7. Research on the method of information system risk state estimation based on clustering particle filter

    Directory of Open Access Journals (Sweden)

    Cui Jia

    2017-05-01

    Full Text Available With the purpose of reinforcing correlation analysis of risk assessment threat factors, a dynamic assessment method of safety risks based on particle filtering is proposed, which takes threat analysis as the core. Based on the risk assessment standards, the method selects threat indicates, applies a particle filtering algorithm to calculate influencing weight of threat indications, and confirms information system risk levels by combining with state estimation theory. In order to improve the calculating efficiency of the particle filtering algorithm, the k-means cluster algorithm is introduced to the particle filtering algorithm. By clustering all particles, the author regards centroid as the representative to operate, so as to reduce calculated amount. The empirical experience indicates that the method can embody the relation of mutual dependence and influence in risk elements reasonably. Under the circumstance of limited information, it provides the scientific basis on fabricating a risk management control strategy.

  8. Research on the method of information system risk state estimation based on clustering particle filter

    Science.gov (United States)

    Cui, Jia; Hong, Bei; Jiang, Xuepeng; Chen, Qinghua

    2017-05-01

    With the purpose of reinforcing correlation analysis of risk assessment threat factors, a dynamic assessment method of safety risks based on particle filtering is proposed, which takes threat analysis as the core. Based on the risk assessment standards, the method selects threat indicates, applies a particle filtering algorithm to calculate influencing weight of threat indications, and confirms information system risk levels by combining with state estimation theory. In order to improve the calculating efficiency of the particle filtering algorithm, the k-means cluster algorithm is introduced to the particle filtering algorithm. By clustering all particles, the author regards centroid as the representative to operate, so as to reduce calculated amount. The empirical experience indicates that the method can embody the relation of mutual dependence and influence in risk elements reasonably. Under the circumstance of limited information, it provides the scientific basis on fabricating a risk management control strategy.

  9. Risk-based approach to long-term safety assessment for near surface disposal of radioactive waste in Korea

    International Nuclear Information System (INIS)

    Jeong, C.W.; Kim, K.I.; Lee, J.I.

    2000-01-01

    This paper presents the Korean regulatory approach to safety assessment consistent with probabilistic, risk-based long-term safety requirements for near surface disposal facilities. The approach is based on: (1) From the standpoint of risk limitation, normal processes and probabilistic disruptive events should be integrated in a similar manner in terms of potential exposures; and (2) The uncertainties inherent in the safety assessment should be reduced using appropriate exposure scenarios. In addition, this paper emphasizes the necessity of international guidance for quantifying potential exposures and the corresponding risks from radioactive waste disposal. (author)

  10. Cost tradeoffs in consequence management at nuclear power plants: A risk based approach to setting optimal long-term interdiction limits for regulatory analyses

    International Nuclear Information System (INIS)

    Mubayi, V.

    1995-05-01

    The consequences of severe accidents at nuclear power plants can be limited by various protective actions, including emergency responses and long-term measures, to reduce exposures of affected populations. Each of these protective actions involve costs to society. The costs of the long-term protective actions depend on the criterion adopted for the allowable level of long-term exposure. This criterion, called the ''long term interdiction limit,'' is expressed in terms of the projected dose to an individual over a certain time period from the long-term exposure pathways. The two measures of offsite consequences, latent cancers and costs, are inversely related and the choice of an interdiction limit is, in effect, a trade-off between these two measures. By monetizing the health effects (through ascribing a monetary value to life lost), the costs of the two consequence measures vary with the interdiction limit, the health effect costs increasing as the limit is relaxed and the protective action costs decreasing. The minimum of the total cost curve can be used to calculate an optimal long term interdiction limit. The calculation of such an optimal limit is presented for each of five US nuclear power plants which were analyzed for severe accident risk in the NUREG-1150 program by the Nuclear Regulatory Commission

  11. Developing safety performance functions incorporating reliability-based risk measures.

    Science.gov (United States)

    Ibrahim, Shewkar El-Bassiouni; Sayed, Tarek

    2011-11-01

    Current geometric design guides provide deterministic standards where the safety margin of the design output is generally unknown and there is little knowledge of the safety implications of deviating from these standards. Several studies have advocated probabilistic geometric design where reliability analysis can be used to account for the uncertainty in the design parameters and to provide a risk measure of the implication of deviation from design standards. However, there is currently no link between measures of design reliability and the quantification of safety using collision frequency. The analysis presented in this paper attempts to bridge this gap by incorporating a reliability-based quantitative risk measure such as the probability of non-compliance (P(nc)) in safety performance functions (SPFs). Establishing this link will allow admitting reliability-based design into traditional benefit-cost analysis and should lead to a wider application of the reliability technique in road design. The present application is concerned with the design of horizontal curves, where the limit state function is defined in terms of the available (supply) and stopping (demand) sight distances. A comprehensive collision and geometric design database of two-lane rural highways is used to investigate the effect of the probability of non-compliance on safety. The reliability analysis was carried out using the First Order Reliability Method (FORM). Two Negative Binomial (NB) SPFs were developed to compare models with and without the reliability-based risk measures. It was found that models incorporating the P(nc) provided a better fit to the data set than the traditional (without risk) NB SPFs for total, injury and fatality (I+F) and property damage only (PDO) collisions. Copyright © 2011 Elsevier Ltd. All rights reserved.

  12. The occupational exposure limit for fluid aerosol generated in metalworking operations: limitations and recommendations.

    Science.gov (United States)

    Park, Donguk

    2012-03-01

    The aim of this review was to assess current knowledge related to the occupational exposure limit (OEL) for fluid aerosols including either mineral or chemical oil that are generated in metalworking operations, and to discuss whether their OEL can be appropriately used to prevent several health risks that may vary among metalworking fluid (MWF) types. The OEL (time-weighted average; 5 mg/m(3), short-term exposure limit ; 15 mg/m(3)) has been applied to MWF aerosols without consideration of different fluid aerosol-size fractions. The OEL, is also based on the assumption that there are no significant differences in risk among fluid types, which may be contentious. Particularly, the health risks from exposure to water-soluble fluids may not have been sufficiently considered. Although adoption of The National Institute for Occupational Safety and Health's recommended exposure limit for MWF aerosol (0.5 mg/m(3)) would be an effective step towards minimizing and evaluating the upper respiratory irritation that may be caused by neat or diluted MWF, this would fail to address the hazards (e.g., asthma and hypersensitivity pneumonitis) caused by microbial contaminants generated only by the use of water-soluble fluids. The absence of an OEL for the water-soluble fluids used in approximately 80-90 % of all applicants may result in limitations of the protection from health risks caused by exposure to those fluids.

  13. A model-based risk management framework

    Energy Technology Data Exchange (ETDEWEB)

    Gran, Bjoern Axel; Fredriksen, Rune

    2002-08-15

    The ongoing research activity addresses these issues through two co-operative activities. The first is the IST funded research project CORAS, where Institutt for energiteknikk takes part as responsible for the work package for Risk Analysis. The main objective of the CORAS project is to develop a framework to support risk assessment of security critical systems. The second, called the Halden Open Dependability Demonstrator (HODD), is established in cooperation between Oestfold University College, local companies and HRP. The objective of HODD is to provide an open-source test bed for testing, teaching and learning about risk analysis methods, risk analysis tools, and fault tolerance techniques. The Inverted Pendulum Control System (IPCON), which main task is to keep a pendulum balanced and controlled, is the first system that has been established. In order to make risk assessment one need to know what a system does, or is intended to do. Furthermore, the risk assessment requires correct descriptions of the system, its context and all relevant features. A basic assumption is that a precise model of this knowledge, based on formal or semi-formal descriptions, such as UML, will facilitate a systematic risk assessment. It is also necessary to have a framework to integrate the different risk assessment methods. The experiences so far support this hypothesis. This report presents CORAS and the CORAS model-based risk management framework, including a preliminary guideline for model-based risk assessment. The CORAS framework for model-based risk analysis offers a structured and systematic approach to identify and assess security issues of ICT systems. From the initial assessment of IPCON, we also believe that the framework is applicable in a safety context. Further work on IPCON, as well as the experiences from the CORAS trials, will provide insight and feedback for further improvements. (Author)

  14. Risk Probability Estimating Based on Clustering

    DEFF Research Database (Denmark)

    Chen, Yong; Jensen, Christian D.; Gray, Elizabeth

    2003-01-01

    of prior experiences, recommendations from a trusted entity or the reputation of the other entity. In this paper we propose a dynamic mechanism for estimating the risk probability of a certain interaction in a given environment using hybrid neural networks. We argue that traditional risk assessment models...... from the insurance industry do not directly apply to ubiquitous computing environments. Instead, we propose a dynamic mechanism for risk assessment, which is based on pattern matching, classification and prediction procedures. This mechanism uses an estimator of risk probability, which is based...

  15. Impact of shutdown risk on risk-based assessment of technical specifications

    International Nuclear Information System (INIS)

    Deriot, S.

    1992-10-01

    This paper describes the current work performed by the Research and Development Division of EDF concerning risk-based assessment of Operating Technical Specifications (OTS). The current risk-based assessment of OTS at EDF is presented. Then, the level 1 Probabilistic Safety Assessment of unit 3 of the Paluel nuclear power station (called PSA 1300) is described. It is fully computerized and takes into account the risk in shutdown states. A case study is presented. It shows that the fact of considering shutdown risk suggests that the current OTS should be modified

  16. Application of discriminant analysis-based model for prediction of risk of low back disorders due to workplace design in industrial jobs.

    Science.gov (United States)

    Ganga, G M D; Esposto, K F; Braatz, D

    2012-01-01

    The occupational exposure limits of different risk factors for development of low back disorders (LBDs) have not yet been established. One of the main problems in setting such guidelines is the limited understanding of how different risk factors for LBDs interact in causing injury, since the nature and mechanism of these disorders are relatively unknown phenomena. Industrial ergonomists' role becomes further complicated because the potential risk factors that may contribute towards the onset of LBDs interact in a complex manner, which makes it difficult to discriminate in detail among the jobs that place workers at high or low risk of LBDs. The purpose of this paper was to develop a comparative study between predictions based on the neural network-based model proposed by Zurada, Karwowski & Marras (1997) and a linear discriminant analysis model, for making predictions about industrial jobs according to their potential risk of low back disorders due to workplace design. The results obtained through applying the discriminant analysis-based model proved that it is as effective as the neural network-based model. Moreover, the discriminant analysis-based model proved to be more advantageous regarding cost and time savings for future data gathering.

  17. Risk-based decisionmaking (Panel)

    Energy Technology Data Exchange (ETDEWEB)

    Smith, T.H.

    1995-12-31

    By means of a panel discussion and extensive audience interaction, explore the current challenges and progress to date in applying risk considerations to decisionmaking related to low-level waste. This topic is especially timely because of the proposed legislation pertaining to risk-based decisionmaking and because of the increased emphasis placed on radiological performance assessments of low-level waste disposal.

  18. Approach and issues toward development of risk-based release standards for radioactive scrap metal recycle and reuse

    International Nuclear Information System (INIS)

    Chen, S.Y.; Nieves, L.A.; Nabelssi, B.K.; LePoire, D.J.

    1994-01-01

    The decontamination and decommissioning of nuclear facilities is expected to generate large amounts of slightly radioactive scrap metal (RSM). It is likely that some of these materials will be suitable for recycling and reuse. The amount of scrap steel from DOE facilities, for instance, is estimated to be more than one million tons (Hertzler 1993). However, under current practice and without the establishment of acceptable recycling standards, the RSM would be disposed of primarily as radioactive low-level waste (LLW). In the United States, no specific standards have been developed for the unrestricted release of bulk contaminated materials. Although standards for unrestricted release of radioactive surface contamination (NRC 1974) have existed for about 20 years, the release of materials is not commonly practiced because of the lack of risk-based justifications. Recent guidance from international bodies (IAEA 1988) has established a basis for deriving risk-based release limits for radioactive materials. It is important, therefore, to evaluate the feasibility of recycling and associated issues necessary for the establishment of risk-based release limits for the radioactive metals

  19. Limited probabilistic risk assessment applications in plant backfitting

    International Nuclear Information System (INIS)

    Desaedeleer, G.

    1987-01-01

    Plant backfitting programs are defined on the basis of deterministic (e.g. Systematic Evaluation Program) or probabilistic (e.g. Probabilistic Risk Assessment) approaches. Each approach provides valuable assets in defining the program and has its own advantages and disadvantages. Ideally one should combine the strong points of each approach. This chapter summarizes actual experience gained from combinations of deterministic and probabilistic approaches to define and implement PWR backfitting programs. Such combinations relate to limited applications of probabilistic techniques and are illustrated for upgrading fluid systems. These evaluations allow sound and rational optimization systems upgrade. However, the boundaries of the reliability analysis need to be clearly defined and system reliability may have to go beyond classical boundaries (e.g. identification of weak links in support systems). Also the implementation of upgrade on a system per system basis is not necessarily cost-effective. (author)

  20. Ecohydrology of agroecosystems: probabilistic description of yield reduction risk under limited water availability

    Science.gov (United States)

    Vico, Giulia; Porporato, Amilcare

    2013-04-01

    Supplemental irrigation represents one of the main strategies to mitigate the effects of climate variability and stabilize yields. Irrigated agriculture currently provides 40% of food production and its relevance is expected to further increase in the near future, in face of the projected alterations of rainfall patterns and increase in food, fiber, and biofuel demand. Because of the significant investments and water requirements involved in irrigation, strategic choices are needed to preserve productivity and profitability, while maintaining a sustainable water management - a nontrivial task given the unpredictability of the rainfall forcing. To facilitate decision making under uncertainty, a widely applicable probabilistic framework is proposed. The occurrence of rainfall events and irrigation applications are linked probabilistically to crop development during the growing season and yields at harvest. Based on these linkages, the probability density function of yields and corresponding probability density function of required irrigation volumes, as well as the probability density function of yields under the most common case of limited water availability are obtained analytically, as a function of irrigation strategy, climate, soil and crop parameters. The full probabilistic description of the frequency of occurrence of yields and water requirements is a crucial tool for decision making under uncertainty, e.g., via expected utility analysis. Furthermore, the knowledge of the probability density function of yield allows us to quantify the yield reduction hydrologic risk. Two risk indices are defined and quantified: the long-term risk index, suitable for long-term irrigation strategy assessment and investment planning, and the real-time risk index, providing a rigorous probabilistic quantification of the emergence of drought conditions during a single growing season in an agricultural setting. Our approach employs relatively few parameters and is thus easily and

  1. Risk control and the minimum significant risk

    International Nuclear Information System (INIS)

    Seiler, F.A.; Alvarez, J.L.

    1996-01-01

    Risk management implies that the risk manager can, by his actions, exercise at least a modicum of control over the risk in question. In the terminology of control theory, a management action is a control signal imposed as feedback on the system to bring about a desired change in the state of the system. In the terminology of risk management, an action is taken to bring a predicted risk to lower values. Even if it is assumed that the management action taken is 100% effective and that the projected risk reduction is infinitely well known, there is a lower limit to the desired effects that can be achieved. It is based on the fact that all risks, such as the incidence of cancer, exhibit a degree of variability due to a number of extraneous factors such as age at exposure, sex, location, and some lifestyle parameters such as smoking or the consumption of alcohol. If the control signal is much smaller than the variability of the risk, the signal is lost in the noise and control is lost. This defines a minimum controllable risk based on the variability of the risk over the population considered. This quantity is the counterpart of the minimum significant risk which is defined by the uncertainties of the risk model. Both the minimum controllable risk and the minimum significant risk are evaluated for radiation carcinogenesis and are shown to be of the same order of magnitude. For a realistic management action, the assumptions of perfectly effective action and perfect model prediction made above have to be dropped, resulting in an effective minimum controllable risk which is determined by both risk limits. Any action below that effective limit is futile, but it is also unethical due to the ethical requirement of doing more good than harm. Finally, some implications of the effective minimum controllable risk on the use of the ALARA principle and on the evaluation of remedial action goals are presented

  2. The nuclear option in front of climate change. Associated risks, limitations and inhibition to alternatives

    International Nuclear Information System (INIS)

    Marignac, Yves; Besnard, Manon

    2015-10-01

    Within the context of struggle against climate change, the reduction of fossil energy consumption and of the associated carbon dioxide production is considered as the main lever of reduction of greenhouse gas emissions, and nuclear energy is then a matter of debate as a massively available de-carbonated energy but presenting some unacceptable risks. In this synthesis, the authors first propose an overview of risks which cannot be separated from the use of nuclear energy: proliferation as a major, persistent and often ignored threat, a re-assessed and increasing risk of accident, and an accumulation of wastes, materials and sites. In a second part, they show that it has a limited efficiency on emission reduction: indirect but non-null CO 2 emissions, influence of the energy mix, marginal contribution to emission management, declining energetic and climatic role, limited field of action. In the third part, the authors state that nuclear energy could be an inhibitor to the most performing solutions

  3. Familial risk of epilepsy: a population-based study

    Science.gov (United States)

    Peljto, Anna L.; Barker-Cummings, Christie; Vasoli, Vincent M.; Leibson, Cynthia L.; Hauser, W. Allen; Buchhalter, Jeffrey R.

    2014-01-01

    Almost all previous studies of familial risk of epilepsy have had potentially serious methodological limitations. Our goal was to address these limitations and provide more rigorous estimates of familial risk in a population-based study. We used the unique resources of the Rochester Epidemiology Project to identify all 660 Rochester, Minnesota residents born in 1920 or later with incidence of epilepsy from 1935–94 (probands) and their 2439 first-degree relatives who resided in Olmsted County. We assessed incidence of epilepsy in relatives by comprehensive review of the relatives’ medical records, and estimated age-specific cumulative incidence and standardized incidence ratios for epilepsy in relatives compared with the general population, according to proband and relative characteristics. Among relatives of all probands, cumulative incidence of epilepsy to age 40 was 4.7%, and risk was increased 3.3-fold (95% confidence interval 2.75–5.99) compared with population incidence. Risk was increased to the greatest extent in relatives of probands with idiopathic generalized epilepsies (standardized incidence ratio 6.0) and epilepsies associated with intellectual or motor disability presumed present from birth, which we denoted ‘prenatal/developmental cause’ (standardized incidence ratio 4.3). Among relatives of probands with epilepsy without identified cause (including epilepsies classified as ‘idiopathic’ or ‘unknown cause’), risk was significantly increased for epilepsy of prenatal/developmental cause (standardized incidence ratio 4.1). Similarly, among relatives of probands with prenatal/developmental cause, risk was significantly increased for epilepsies without identified cause (standardized incidence ratio 3.8). In relatives of probands with generalized epilepsy, standardized incidence ratios were 8.3 (95% confidence interval 2.93–15.31) for generalized epilepsy and 2.5 (95% confidence interval 0.92–4.00) for focal epilepsy. In relatives of

  4. Quality expectations and tolerance limits of trial master files (TMF) – Developing a risk-based approach for quality assessments of TMFs

    Science.gov (United States)

    Hecht, Arthur; Busch-Heidger, Barbara; Gertzen, Heiner; Pfister, Heike; Ruhfus, Birgit; Sanden, Per-Holger; Schmidt, Gabriele B.

    2015-01-01

    This article addresses the question of when a trial master file (TMF) can be considered sufficiently accurate and complete: What attributes does the TMF need to have so that a clinical trial can be adequately reconstructed from documented data and procedures? Clinical trial sponsors face significant challenges in assembling the TMF, especially when dealing with large, international, multicenter studies; despite all newly introduced archiving techniques it is becoming more and more difficult to ensure that the TMF is complete. This is directly reflected in the number of inspection findings reported and published by the EMA in 2014. Based on quality risk management principles in clinical trials the authors defined the quality expectations for the different document types in a TMF and furthermore defined tolerance limits for missing documents. This publication provides guidance on what type of documents and processes are most important, and in consequence, indicates on which documents and processes trial team staff should focus in order to achieve a high-quality TMF. The members of this working group belong to the CQAG Group (Clinical Quality Assurance Germany) and are QA (quality assurance) experts (auditors or compliance functions) with long-term experience in the practical handling of TMFs. PMID:26693218

  5. Quality expectations and tolerance limits of trial master files (TMF – Developing a risk-based approach for quality assessments of TMFs

    Directory of Open Access Journals (Sweden)

    Hecht, Arthur

    2015-12-01

    Full Text Available This article addresses the question of when a trial master file (TMF can be considered sufficiently accurate and complete: What attributes does the TMF need to have so that a clinical trial can be adequately reconstructed from documented data and procedures? Clinical trial sponsors face significant challenges in assembling the TMF, especially when dealing with large, international, multicenter studies; despite all newly introduced archiving techniques it is becoming more and more difficult to ensure that the TMF is complete. This is directly reflected in the number of inspection findings reported and published by the EMA in 2014. Based on quality risk management principles in clinical trials the authors defined the quality expectations for the different document types in a TMF and furthermore defined tolerance limits for missing documents. This publication provides guidance on what type of documents and processes are most important, and in consequence, indicates on which documents and processes trial team staff should focus in order to achieve a high-quality TMF.The members of this working group belong to the CQAG Group (Clinical Quality Assurance Germany and are QA (quality assurance experts (auditors or compliance functions with long-term experience in the practical handling of TMFs.

  6. The Occupational Exposure Limit for Fluid Aerosol Generated in Metalworking Operations: Limitations and Recommendations

    Directory of Open Access Journals (Sweden)

    Donguk Park

    2012-03-01

    Full Text Available The aim of this review was to assess current knowledge related to the occupational exposure limit (OEL for fluid aerosols including either mineral or chemical oil that are generated in metalworking operations, and to discuss whether their OEL can be appropriately used to prevent several health risks that may vary among metalworking fluid (MWF types. The OEL (time-weighted average; 5 mg/m3, short-term exposure limit ; 15 mg/m3 has been applied to MWF aerosols without consideration of different fluid aerosol-size fractions. The OEL, is also based on the assumption that there are no significant differences in risk among fluid types, which may be contentious. Particularly, the health risks from exposure to water-soluble fluids may not have been sufficiently considered. Although adoption of The National Institute for Occupational Safety and Health's recommended exposure limit for MWF aerosol (0.5 mg/m3 would be an effective step towards minimizing and evaluating the upper respiratory irritation that may be caused by neat or diluted MWF, this would fail to address the hazards (e.g., asthma and hypersensitivity pneumonitis caused by microbial contaminants generated only by the use of water-soluble fluids. The absence of an OEL for the water-soluble fluids used in approximately 80-90 % of all applicants may result in limitations of the protection from health risks caused by exposure to those fluids.

  7. Application and Evaluation of Control Modes for Risk-Based Engine Performance Enhancements

    Science.gov (United States)

    Liu, Yuan; Litt, Jonathan S.; Sowers, T. Shane; Owen, A. Karl; Guo, Ten-Huei

    2015-01-01

    The engine control system for civil transport aircraft imposes operational limits on the propulsion system to ensure compliance with safety standards. However, during certain emergency situations, aircraft survivability may benefit from engine performance beyond its normal limits despite the increased risk of failure. Accordingly, control modes were developed to improve the maximum thrust output and responsiveness of a generic high-bypass turbofan engine. The algorithms were designed such that the enhanced performance would always constitute an elevation in failure risk to a consistent predefined likelihood. This paper presents an application of these risk-based control modes to a combined engine/aircraft model. Through computer and piloted simulation tests, the aim is to present a notional implementation of these modes, evaluate their effects on a generic airframe, and demonstrate their usefulness during emergency flight situations. Results show that minimal control effort is required to compensate for the changes in flight dynamics due to control mode activation. The benefits gained from enhanced engine performance for various runway incursion scenarios are investigated. Finally, the control modes are shown to protect against potential instabilities during propulsion-only flight where all aircraft control surfaces are inoperable.

  8. Designing and evaluating risk-based surveillance systems

    DEFF Research Database (Denmark)

    Willeberg, Preben; Nielsen, Liza Rosenbaum; Salman, Mo

    2012-01-01

    Risk-based surveillance systems reveal occurrence of disease or infection in a sample of population units, which are selected on the basis of risk factors for the condition under study. The purpose of such systems for supporting practical animal disease policy formulations and management decisions...... with prudent use of resources while maintaining acceptable system performance. High-risk category units are selected for testing by identification of the presence of specific high-risk factor(s), while disregarding other factors that might also influence the risk. On this basis we argue that the most...... applicable risk estimate for use in designing and evaluating a risk-based surveillance system would be a crude (unadjusted) relative risk, odds ratio or apparent prevalence. Risk estimates found in the published literature, however, are often the results of multivariable analyses implicitly adjusting...

  9. Cost effectiveness of risk-based closures at UST sites

    International Nuclear Information System (INIS)

    Scruton, K.M.; Baker, J.N.

    1995-01-01

    Risk-based closures have been achieved at Underground Storage Tank (UST) sites throughout the country for a major transportation company. The risk-based closures were cost-effective because a streamlined risk-based approach was used instead of the generic baseline risk assessment approach. USEPA has recently provided guidance encouraging the use of risk-based methodology for achieving closure at UST sites. The risk-based approach used in achieving the site closures involved an identification of potential human and ecological receptors and exposure pathways, and a comparison of maximum onsite chemical concentrations to applicable or relevant and appropriate requirements (ARARs). The ARARs used in the evaluation included Federal and/or State Maximum Contaminant Levels (MCLs) for groundwater and risk-based screening levels for soils. If the maximum concentrations were above the screening levels, a baseline risk assessment was recommended. In several instances, however, the risk-based approach resulted in a regulatory agency acceptance of a ''no further action'' alternative at UST sites which did not pose a significant threat to human health and the environment. The cost of the streamlined risk-based approach is approximately $3,500, while a baseline risk assessment for the same UST site could cost up to $10,000 or more. The use of the streamlined risk-based approach has proven to be successful for achieving a ''no further action'' outcome for the client at a reasonable cost

  10. Assessment of drug-induced arrhythmic risk using limit cycle and autocorrelation analysis of human iPSC-cardiomyocyte contractility

    Energy Technology Data Exchange (ETDEWEB)

    Kirby, R. Jason [Sanford Burnham Prebys Medical Discovery Institute, Conrad Prebys Center for Chemical Genomics, 6400 Sanger Rd, Orlando, FL 32827 (United States); Qi, Feng [Sanford Burnham Prebys Medical Discovery Institute, Applied Bioinformatics Facility, 6400 Sanger Rd, Orlando, FL 32827 (United States); Phatak, Sharangdhar; Smith, Layton H. [Sanford Burnham Prebys Medical Discovery Institute, Conrad Prebys Center for Chemical Genomics, 6400 Sanger Rd, Orlando, FL 32827 (United States); Malany, Siobhan, E-mail: smalany@sbpdiscovery.org [Sanford Burnham Prebys Medical Discovery Institute, Conrad Prebys Center for Chemical Genomics, 6400 Sanger Rd, Orlando, FL 32827 (United States)

    2016-08-15

    Cardiac safety assays incorporating label-free detection of human stem-cell derived cardiomyocyte contractility provide human relevance and medium throughput screening to assess compound-induced cardiotoxicity. In an effort to provide quantitative analysis of the large kinetic datasets resulting from these real-time studies, we applied bioinformatic approaches based on nonlinear dynamical system analysis, including limit cycle analysis and autocorrelation function, to systematically assess beat irregularity. The algorithms were integrated into a software program to seamlessly generate results for 96-well impedance-based data. Our approach was validated by analyzing dose- and time-dependent changes in beat patterns induced by known proarrhythmic compounds and screening a cardiotoxicity library to rank order compounds based on their proarrhythmic potential. We demonstrate a strong correlation for dose-dependent beat irregularity monitored by electrical impedance and quantified by autocorrelation analysis to traditional manual patch clamp potency values for hERG blockers. In addition, our platform identifies non-hERG blockers known to cause clinical arrhythmia. Our method provides a novel suite of medium-throughput quantitative tools for assessing compound effects on cardiac contractility and predicting compounds with potential proarrhythmia and may be applied to in vitro paradigms for pre-clinical cardiac safety evaluation. - Highlights: • Impedance-based monitoring of human iPSC-derived cardiomyocyte contractility • Limit cycle analysis of impedance data identifies aberrant oscillation patterns. • Nonlinear autocorrelation function quantifies beat irregularity. • Identification of hERG and non-hERG inhibitors with known risk of arrhythmia • Automated software processes limit cycle and autocorrelation analyses of 96w data.

  11. Assessment of drug-induced arrhythmic risk using limit cycle and autocorrelation analysis of human iPSC-cardiomyocyte contractility

    International Nuclear Information System (INIS)

    Kirby, R. Jason; Qi, Feng; Phatak, Sharangdhar; Smith, Layton H.; Malany, Siobhan

    2016-01-01

    Cardiac safety assays incorporating label-free detection of human stem-cell derived cardiomyocyte contractility provide human relevance and medium throughput screening to assess compound-induced cardiotoxicity. In an effort to provide quantitative analysis of the large kinetic datasets resulting from these real-time studies, we applied bioinformatic approaches based on nonlinear dynamical system analysis, including limit cycle analysis and autocorrelation function, to systematically assess beat irregularity. The algorithms were integrated into a software program to seamlessly generate results for 96-well impedance-based data. Our approach was validated by analyzing dose- and time-dependent changes in beat patterns induced by known proarrhythmic compounds and screening a cardiotoxicity library to rank order compounds based on their proarrhythmic potential. We demonstrate a strong correlation for dose-dependent beat irregularity monitored by electrical impedance and quantified by autocorrelation analysis to traditional manual patch clamp potency values for hERG blockers. In addition, our platform identifies non-hERG blockers known to cause clinical arrhythmia. Our method provides a novel suite of medium-throughput quantitative tools for assessing compound effects on cardiac contractility and predicting compounds with potential proarrhythmia and may be applied to in vitro paradigms for pre-clinical cardiac safety evaluation. - Highlights: • Impedance-based monitoring of human iPSC-derived cardiomyocyte contractility • Limit cycle analysis of impedance data identifies aberrant oscillation patterns. • Nonlinear autocorrelation function quantifies beat irregularity. • Identification of hERG and non-hERG inhibitors with known risk of arrhythmia • Automated software processes limit cycle and autocorrelation analyses of 96w data

  12. Risk based inspection for atmospheric storage tank

    Science.gov (United States)

    Nugroho, Agus; Haryadi, Gunawan Dwi; Ismail, Rifky; Kim, Seon Jin

    2016-04-01

    Corrosion is an attack that occurs on a metallic material as a result of environment's reaction.Thus, it causes atmospheric storage tank's leakage, material loss, environmental pollution, equipment failure and affects the age of process equipment then finally financial damage. Corrosion risk measurement becomesa vital part of Asset Management at the plant for operating any aging asset.This paper provides six case studies dealing with high speed diesel atmospheric storage tank parts at a power plant. A summary of the basic principles and procedures of corrosion risk analysis and RBI applicable to the Process Industries were discussed prior to the study. Semi quantitative method based onAPI 58I Base-Resource Document was employed. The risk associated with corrosion on the equipment in terms of its likelihood and its consequences were discussed. The corrosion risk analysis outcome used to formulate Risk Based Inspection (RBI) method that should be a part of the atmospheric storage tank operation at the plant. RBI gives more concern to inspection resources which are mostly on `High Risk' and `Medium Risk' criteria and less on `Low Risk' shell. Risk categories of the evaluated equipment were illustrated through case study analysis outcome.

  13. Limit loads for pipe bends under combined pressure and in-plane bending based on finite element limit analysis

    International Nuclear Information System (INIS)

    Oh, Chang Sik; Kim, Yun Jae

    2006-01-01

    In the present paper, approximate plastic limit load solutions for pipe bends under combined internal pressure and bending are obtained from detailed three-dimensional (3-D) FE limit analyses based on elastic-perfectly plastic materials with the small geometry change option. The present FE results show that existing limit load solutions for pipe bends are lower bounds but can be very different from the present FE results in some cases, particularly for bending. Accordingly closed-form approximations are proposed for pipe bends under combined pressure and in-plane bending based on the present FE results. The proposed limit load solutions would be a basis of defective pipe bends and be useful to estimate non-linear fracture mechanics parameters based on the reference stress approach

  14. A Risk Prediction Model for Sporadic CRC Based on Routine Lab Results.

    Science.gov (United States)

    Boursi, Ben; Mamtani, Ronac; Hwang, Wei-Ting; Haynes, Kevin; Yang, Yu-Xiao

    2016-07-01

    Current risk scores for colorectal cancer (CRC) are based on demographic and behavioral factors and have limited predictive values. To develop a novel risk prediction model for sporadic CRC using clinical and laboratory data in electronic medical records. We conducted a nested case-control study in a UK primary care database. Cases included those with a diagnostic code of CRC, aged 50-85. Each case was matched with four controls using incidence density sampling. CRC predictors were examined using univariate conditional logistic regression. Variables with p value CRC prediction models which included age, sex, height, obesity, ever smoking, alcohol dependence, and previous screening colonoscopy had an AUC of 0.58 (0.57-0.59) with poor goodness of fit. A laboratory-based model including hematocrit, MCV, lymphocytes, and neutrophil-lymphocyte ratio (NLR) had an AUC of 0.76 (0.76-0.77) and a McFadden's R2 of 0.21 with a NRI of 47.6 %. A combined model including sex, hemoglobin, MCV, white blood cells, platelets, NLR, and oral hypoglycemic use had an AUC of 0.80 (0.79-0.81) with a McFadden's R2 of 0.27 and a NRI of 60.7 %. Similar results were shown in an internal validation set. A laboratory-based risk model had good predictive power for sporadic CRC risk.

  15. Backtesting for Risk-Based Regulatory Capital

    NARCIS (Netherlands)

    Kerkhof, F.L.J.; Melenberg, B.

    2002-01-01

    In this paper we present a framework for backtesting all currently popular risk measurement methods (including value-at-risk and expected shortfall) using the functional delta method.Estimation risk can be taken explicitly into account.Based on a simulation study we provide evidence that tests for

  16. Toward risk assessment 2.0: Safety supervisory control and model-based hazard monitoring for risk-informed safety interventions

    International Nuclear Information System (INIS)

    Favarò, Francesca M.; Saleh, Joseph H.

    2016-01-01

    Probabilistic Risk Assessment (PRA) is a staple in the engineering risk community, and it has become to some extent synonymous with the entire quantitative risk assessment undertaking. Limitations of PRA continue to occupy researchers, and workarounds are often proposed. After a brief review of this literature, we propose to address some of PRA's limitations by developing a novel framework and analytical tools for model-based system safety, or safety supervisory control, to guide safety interventions and support a dynamic approach to risk assessment and accident prevention. Our work shifts the emphasis from the pervading probabilistic mindset in risk assessment toward the notions of danger indices and hazard temporal contingency. The framework and tools here developed are grounded in Control Theory and make use of the state-space formalism in modeling dynamical systems. We show that the use of state variables enables the definition of metrics for accident escalation, termed hazard levels or danger indices, which measure the “proximity” of the system state to adverse events, and we illustrate the development of such indices. Monitoring of the hazard levels provides diagnostic information to support both on-line and off-line safety interventions. For example, we show how the application of the proposed tools to a rejected takeoff scenario provides new insight to support pilots’ go/no-go decisions. Furthermore, we augment the traditional state-space equations with a hazard equation and use the latter to estimate the times at which critical thresholds for the hazard level are (b)reached. This estimation process provides important prognostic information and produces a proxy for a time-to-accident metric or advance notice for an impending adverse event. The ability to estimate these two hazard coordinates, danger index and time-to-accident, offers many possibilities for informing system control strategies and improving accident prevention and risk mitigation

  17. Integrating adaptive behaviour in large-scale flood risk assessments: an Agent-Based Modelling approach

    Science.gov (United States)

    Haer, Toon; Aerts, Jeroen

    2015-04-01

    Between 1998 and 2009, Europe suffered over 213 major damaging floods, causing 1126 deaths, displacing around half a million people. In this period, floods caused at least 52 billion euro in insured economic losses making floods the most costly natural hazard faced in Europe. In many low-lying areas, the main strategy to cope with floods is to reduce the risk of the hazard through flood defence structures, like dikes and levees. However, it is suggested that part of the responsibility for flood protection needs to shift to households and businesses in areas at risk, and that governments and insurers can effectively stimulate the implementation of individual protective measures. However, adaptive behaviour towards flood risk reduction and the interaction between the government, insurers, and individuals has hardly been studied in large-scale flood risk assessments. In this study, an European Agent-Based Model is developed including agent representatives for the administrative stakeholders of European Member states, insurers and reinsurers markets, and individuals following complex behaviour models. The Agent-Based Modelling approach allows for an in-depth analysis of the interaction between heterogeneous autonomous agents and the resulting (non-)adaptive behaviour. Existing flood damage models are part of the European Agent-Based Model to allow for a dynamic response of both the agents and the environment to changing flood risk and protective efforts. By following an Agent-Based Modelling approach this study is a first contribution to overcome the limitations of traditional large-scale flood risk models in which the influence of individual adaptive behaviour towards flood risk reduction is often lacking.

  18. Risk-based decision analysis for groundwater operable units

    International Nuclear Information System (INIS)

    Chiaramonte, G.R.

    1995-01-01

    This document proposes a streamlined approach and methodology for performing risk assessment in support of interim remedial measure (IRM) decisions involving the remediation of contaminated groundwater on the Hanford Site. This methodology, referred to as ''risk-based decision analysis,'' also supports the specification of target cleanup volumes and provides a basis for design and operation of the groundwater remedies. The risk-based decision analysis can be completed within a short time frame and concisely documented. The risk-based decision analysis is more versatile than the qualitative risk assessment (QRA), because it not only supports the need for IRMs, but also provides criteria for defining the success of the IRMs and provides the risk-basis for decisions on final remedies. For these reasons, it is proposed that, for groundwater operable units, the risk-based decision analysis should replace the more elaborate, costly, and time-consuming QRA

  19. Habit-based Asset Pricing with Limited Participation Consumption

    DEFF Research Database (Denmark)

    Bach, Christian; Møller, Stig Vinther

    We calibrate and estimate a consumption-based asset pricing model with habit formation using limited participation consumption data. Based on survey data of a representative sample of American households, we distinguish between assetholder and non-assetholder consumption, as well as the standard...

  20. Habit-based asset pricing with limited participation consumption

    DEFF Research Database (Denmark)

    Møller, Stig Vinther; Bach, Christian

    2011-01-01

    We calibrate and estimate a consumption-based asset pricing model with habit formation using limited participation consumption data. Based on survey data of a representative sample of American households, we distinguish between assetholder and non-assetholder consumption, as well as the standard...

  1. Aggregate Exposure and Cumulative Risk Assessment--Integrating Occupational and Non-occupational Risk Factors.

    Science.gov (United States)

    Lentz, T J; Dotson, G S; Williams, P R D; Maier, A; Gadagbui, B; Pandalai, S P; Lamba, A; Hearl, F; Mumtaz, M

    2015-01-01

    Occupational exposure limits have traditionally focused on preventing morbidity and mortality arising from inhalation exposures to individual chemical stressors in the workplace. While central to occupational risk assessment, occupational exposure limits have limited application as a refined disease prevention tool because they do not account for all of the complexities of the work and non-occupational environments and are based on varying health endpoints. To be of greater utility, occupational exposure limits and other risk management tools could integrate broader consideration of risks from multiple exposure pathways and routes (aggregate risk) as well as the combined risk from exposure to both chemical and non-chemical stressors, within and beyond the workplace, including the possibility that such exposures may cause interactions or modify the toxic effects observed (cumulative risk). Although still at a rudimentary stage in many cases, a variety of methods and tools have been developed or are being used in allied risk assessment fields to incorporate such considerations in the risk assessment process. These approaches, which are collectively referred to as cumulative risk assessment, have potential to be adapted or modified for occupational scenarios and provide a tangible path forward for occupational risk assessment. Accounting for complex exposures in the workplace and the broader risks faced by the individual also requires a more complete consideration of the composite effects of occupational and non-occupational risk factors to fully assess and manage worker health problems. Barriers to integrating these different factors remain, but new and ongoing community-based and worker health-related initiatives may provide mechanisms for identifying and integrating risk from aggregate exposures and cumulative risks from all relevant sources, be they occupational or non-occupational.

  2. Principles of risk-based decision making

    National Research Council Canada - National Science Library

    United States. Coast Guard. Risk based decision-making guidelines

    2001-01-01

    ... original content in order to make this product more generically applicable and less Coast Guard specific. h s k assessment and risk management are important topics in industry and government. Because of limited resources and increasing demands for services, most organizations simply cannot continue business as usual. Even if resources are not dec...

  3. Bipolar-power-transistor-based limiter for high frequency ultrasound imaging systems.

    Science.gov (United States)

    Choi, Hojong; Yang, Hao-Chung; Shung, K Kirk

    2014-03-01

    High performance limiters are described in this paper for applications in high frequency ultrasound imaging systems. Limiters protect the ultrasound receiver from the high voltage (HV) spikes produced by the transmitter. We present a new bipolar power transistor (BPT) configuration and compare its design and performance to a diode limiter used in traditional ultrasound research and one commercially available limiter. Limiter performance depends greatly on the insertion loss (IL), total harmonic distortion (THD) and response time (RT), each of which will be evaluated in all the limiters. The results indicated that, compared with commercial limiter, BPT-based limiter had less IL (-7.7 dB), THD (-74.6 dB) and lower RT (43 ns) at 100 MHz. To evaluate the capability of these limiters, they were connected to a 100 MHz single element transducer and a two-way pulse-echo test was performed. It was found that the -6 dB bandwidth and sensitivity of the transducer using BPT-based limiter were better than those of the commercial limiter by 22% and 140%, respectively. Compared to the commercial limiter, BPT-based limiter is shown to be capable of minimizing signal attenuation, RT and THD at high frequencies and is thus suited for high frequency ultrasound applications. Copyright © 2013 Elsevier B.V. All rights reserved.

  4. Methods for risk-based planning of O&M of wind turbines

    DEFF Research Database (Denmark)

    Nielsen, Jannie Sønderkær; Sørensen, John Dalsgaard

    2014-01-01

    take more information into account, and especially, the method based on the Markov decision process is very flexible and accurate. A case study shows that the Markov decision process and decision rules based on the probability of failure are equally good and give lower costs compared to decision rules......In order to make wind energy more competitive, the big expenses for operation and maintenance must be reduced. Consistent decisions that minimize the expected costs can be made based on risk-based methods. Such methods have been implemented for maintenance planning for oil and gas structures......, a method based on limited memory influence diagrams and a method based on the partially observable Markov decision process. The methods with decision rules based on observed variables are easy to use, but can only take the most recent observation into account, when a decision is made. The other methods can...

  5. Component Degradation Susceptibilities As The Bases For Modeling Reactor Aging Risk

    International Nuclear Information System (INIS)

    Unwin, Stephen D.; Lowry, Peter P.; Toyooka, Michael Y.

    2010-01-01

    The extension of nuclear power plant operating licenses beyond 60 years in the United States will be necessary if we are to meet national energy needs while addressing the issues of carbon and climate. Characterizing the operating risks associated with aging reactors is problematic because the principal tool for risk-informed decision-making, Probabilistic Risk Assessment (PRA), is not ideally-suited to addressing aging systems. The components most likely to drive risk in an aging reactor - the passives - receive limited treatment in PRA, and furthermore, standard PRA methods are based on the assumption of stationary failure rates: a condition unlikely to be met in an aging system. A critical barrier to modeling passives aging on the wide scale required for a PRA is that there is seldom sufficient field data to populate parametric failure models, and nor is there the availability of practical physics models to predict out-year component reliability. The methodology described here circumvents some of these data and modeling needs by using materials degradation metrics, integrated with conventional PRA models, to produce risk importance measures for specific aging mechanisms and component types. We suggest that these measures have multiple applications, from the risk-screening of components to the prioritization of materials research.

  6. Research needs for risk-informed, performance-based regulations

    International Nuclear Information System (INIS)

    Thadani, A.C.

    1997-01-01

    This article summarizes the activities of the Office of Research of the NRC, both from a historical aspect as well as it applies to the application of risk-based decision making. The office has been actively involved in problems related to understanding risks related to core accidents, to understanding the problem of aging of reactor components and materials from years of service, and toward the understanding and analysis of severe accidents. In addition new policy statements regarding the role of risk assessment in regulatory applications has given focus for the need of further work. The NRC has used risk assessment in regulatory questions in the past but in a fairly ad hoc sort of manner. The new policies will clearly require a better defined application of risk assessment, and help for people evaluating applications in judging the applicability of such applications when a component of them is based on risk-based decision making. To address this, standard review plans are being prepared to serve as guides for such questions. In addition, with regulatory decisions being allowed to be based upon risk-based decisions, it is necessary to have an adequate data base prepared, and made publically available, to support such a position

  7. Risk of Debt-Based Financing in Indonesian Islamic Banking

    Directory of Open Access Journals (Sweden)

    Kharisya Ayu Effendi

    2017-05-01

    Full Text Available The purpose of this study is to know the risk of debt-based financing in Islamic banking in Indonesia by using an accounting based calculation, those are NPF analysis, Credit risk Z-score and Altman Z-score. This study is telling about the risk of debt-based finacing on Indonesian Islamic banking using an accounting based measurement, those are NPF analysis, Credit Risk Z-score analysis and Altman Z-score analysis. The data was obtained from 2011 to 2015 from the website of each bank. The result is a risk on debt-based financing on Indonesian Islamic banking is low. The measurement using 3 accounting based measurement tool gives a consistent result, that is Indonesian Islamic banking use a debt-based financing have a high financial stability and a low risk.DOI: 10.15408/aiq.v9i2.4821

  8. Emerging contaminants in the environment: Risk-based analysis for better management.

    Science.gov (United States)

    Naidu, Ravi; Arias Espana, Victor Andres; Liu, Yanju; Jit, Joytishna

    2016-07-01

    Emerging contaminants (ECs) are chemicals of a synthetic origin or deriving from a natural source that has recently been discovered and for which environmental or public health risks are yet to be established. This is due to limited available information on their interaction and toxicological impacts on receptors. Several types of ECs exist such as antibiotics, pesticides, pharmaceuticals, personal care products, effluents, certain naturally occurring contaminants and more recently nanomaterials. ECs may derive from a known source, for example released directly to the aquatic environment from direct discharges such as those from wastewater treatment plants. Although in most instances the direct source cannot be identified, ECs have been detected in virtually every country's natural environment and as a consequence they represent a global problem. There is very limited information on the fate and transport of ECs in the environment and their toxicological impact. This lack of information can be attributed to limited financial resources and the lack of analytical techniques for detecting their effects on ecosystems and human health on their own or as mixture. We do not know how ECs interact with each other or various contaminants. This paper presents an overview of existing knowledge on ECs, their fate and transport and a risk-based analysis for ECs management and complementary strategies. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Risk based definition of TS requirements for NPPs with WWER-1000 type reactor

    International Nuclear Information System (INIS)

    Morozov, V.; Tokmachev, G.

    2000-01-01

    The main regulations in safety related maintenance for NPPs in Russia are defined as a part of Technical Specifications (TSs). It includes limiting conditions for operation (surveillance requirements, allowed outage time, et.). In Russian practice the two levels of TSs are presented: general TSs that have been established as a master documents for similar designed NPPs and plant specific based on operation practice of each NPP unit. This paper presents a brief review of submissions to TS changes for NPPs with WWER type reactor were issued by AEP PSA team since 1988 year. Besides it provides an approach allows to estimate the complex affect on plant risk for both Limiting Conditions of Operation (LCO) and Surveillance Test Intervals (STI) based on relevant probabilistic tool (Minimal Cut Sets method and Marcov Chains methods). (author)

  10. Analysis and Assessment of Operation Risk for Hybrid AC/DC Power System based on the Monte Carlo Method

    Science.gov (United States)

    Hu, Xiaojing; Li, Qiang; Zhang, Hao; Guo, Ziming; Zhao, Kun; Li, Xinpeng

    2018-06-01

    Based on the Monte Carlo method, an improved risk assessment method for hybrid AC/DC power system with VSC station considering the operation status of generators, converter stations, AC lines and DC lines is proposed. According to the sequential AC/DC power flow algorithm, node voltage and line active power are solved, and then the operation risk indices of node voltage over-limit and line active power over-limit are calculated. Finally, an improved two-area IEEE RTS-96 system is taken as a case to analyze and assessment its operation risk. The results show that the proposed model and method can intuitively and directly reflect the weak nodes and weak lines of the system, which can provide some reference for the dispatching department.

  11. Analysis and Assessment of Operation Risk for Hybrid AC/DC Power System based on the Monte Carlo Method

    Directory of Open Access Journals (Sweden)

    Hu Xiaojing

    2018-01-01

    Full Text Available Based on the Monte Carlo method, an improved risk assessment method for hybrid AC/DC power system with VSC station considering the operation status of generators, converter stations, AC lines and DC lines is proposed. According to the sequential AC/DC power flow algorithm, node voltage and line active power are solved, and then the operation risk indices of node voltage over-limit and line active power over-limit are calculated. Finally, an improved two-area IEEE RTS-96 system is taken as a case to analyze and assessment its operation risk. The results show that the proposed model and method can intuitively and directly reflect the weak nodes and weak lines of the system, which can provide some reference for the dispatching department.

  12. Affordable, automatic quantitative fall risk assessment based on clinical balance scales and Kinect data.

    Science.gov (United States)

    Colagiorgio, P; Romano, F; Sardi, F; Moraschini, M; Sozzi, A; Bejor, M; Ricevuti, G; Buizza, A; Ramat, S

    2014-01-01

    The problem of a correct fall risk assessment is becoming more and more critical with the ageing of the population. In spite of the available approaches allowing a quantitative analysis of the human movement control system's performance, the clinical assessment and diagnostic approach to fall risk assessment still relies mostly on non-quantitative exams, such as clinical scales. This work documents our current effort to develop a novel method to assess balance control abilities through a system implementing an automatic evaluation of exercises drawn from balance assessment scales. Our aim is to overcome the classical limits characterizing these scales i.e. limited granularity and inter-/intra-examiner reliability, to obtain objective scores and more detailed information allowing to predict fall risk. We used Microsoft Kinect to record subjects' movements while performing challenging exercises drawn from clinical balance scales. We then computed a set of parameters quantifying the execution of the exercises and fed them to a supervised classifier to perform a classification based on the clinical score. We obtained a good accuracy (~82%) and especially a high sensitivity (~83%).

  13. Risk-based inspection--Development of guidelines

    International Nuclear Information System (INIS)

    1993-07-01

    Effective inservice inspection programs can play a significant role in minimizing equipment and structural failures. Most of the current inservice inspection programs for light water reactor (LWR) nuclear power plant components are based on experience and engineers' qualitative judgment. These programs include only an implicit consideration of risk, which combines the probability of failure of a component under its operation and loading conditions and the consequences of such failure, if it occurs. This document recommends appropriate methods for establishing a risk-based inspection program for LWR nuclear power plant components. The process has been built from a general methodology (Volume 1) and has been expanded to involve five major steps: defining the system; evaluating qualitative risk assessment results; using this and information from plant probabilistic risk assessments to perform a quantitative risk analysis; selecting target failure probabilities; and developing an inspection program for components using economic decision analysis and structural reliability assessment methods

  14. Can a Risk Factor Based Approach Safely Reduce Screening for Retinopathy of Prematurity?

    Directory of Open Access Journals (Sweden)

    K. M. Friddle

    2017-01-01

    Full Text Available Objective. Current American retinopathy of prematurity (ROP screening guidelines is imprecise for infants ≥ 30 weeks with birth weights between 1500 and 2000 g. Our objective was to evaluate a risk factor based approach for screening premature infants at low risk for severe ROP. Study Design. We performed a 13-year review from Intermountain Health Care (IHC data. All neonates born at ≤32 weeks were reviewed to determine ROP screening and/or development of severe ROP. Severe ROP was defined by stage ≥ 3 or need for laser therapy. Regression analysis was used to identify significant risk factors for severe ROP. Results. We identified 4607 neonates ≤ 32 weeks gestation. Following exclusion for death, with no retinal exam or incomplete data, 2791 (61% were included in the study. Overall, severe ROP occurred in 260 (9.3%, but only 11/1601 ≥ 29 weeks (0.7%. All infants with severe ROP ≥ 29 weeks had at least 2 identified ROP risk factors. Implementation of this risk based screening strategy to the IHC population over the timeline of this study would have eliminated screening in 21% (343/1601 of the screened population. Conclusions. Limiting ROP screening for infants ≥ 29 and ≤ 32 weeks to only those with clinical risk factors could significantly reduce screening exams while identifying all infants with severe ROP.

  15. Risk-Based Operation and Maintenance of Offshore Wind Turbines

    DEFF Research Database (Denmark)

    Nielsen, Jannie Sønderkær

    For offshore wind turbines, maintenance costs are substantial due to a large number of component failures. In addition to the repair costs, equipment costs and lost production costs are large due to limited accessibility to the turbines. In order to reduce the costs, preventive methods can be used......, but presently maintenance is not planned using advanced methods taking all available information into account in a consistent manner. Maintenance decisions can be made based on risk-based methods, where the total expected life cycle costs are minimized. Methods have been developed for assessing the corrective...... maintenance costs, and many studies have also been published for preventive maintenance. However, an important part is the modeling of the relationship between maintenance and reliability, which is typically not modeled in a consistent way. Therefore, the methods cannot be used directly for optimal...

  16. A FTA-based method for risk decision-making in emergency response

    DEFF Research Database (Denmark)

    Liu, Yang; Li, Hongyan

    2014-01-01

    Decision-making problems in emergency response are usually risky and uncertain due to the limited decision data and possible evolvement of emergency scenarios. This paper focuses on a risk decisionmaking problem in emergency response with several distinct characteristics including dynamic...... evolvement process of emergency, multiple scenarios, and impact of response actions on the emergency scenarios. A method based on Fault Tree Analysis (FTA) is proposed to solve the problem. By analyzing the evolvement process of emergency, the Fault Tree (FT) is constructed to describe the logical relations...

  17. Application of REVEAL-W to risk-based configuration control

    International Nuclear Information System (INIS)

    Dezfuli, H.; Meyer, J.; Modarres, M.

    1994-01-01

    Over the past two years, the concept of risk-based configuration control has been introduced to the US Nuclear Regulatory Commission and the nuclear industry. Converting much of the current, deterministically based regulation of nuclear power plants to risk-based regulation can result in lower levels of risk while relieving unnecessary burdens on power plant operators and regulatory staff. To achieve the potential benefits of risk-based configuration control, the risk models developed for nuclear power plants should be (1) flexible enough to effectively support necessary risk calculations, and (2) transparent enough to encourage their use by all parties. To address these needs, SCIENTECH, Inc., has developed the PC-based REVEAL W (formerly known as SMART). This graphic-oriented and user-friendly application software allows the user to develop transparent complex logic models based on the concept of the master plant logic diagram. The logic model is success-oriented and compact. The analytical capability built into REVEAL W is generic, so the software can support different types of risk-based evaluations, such as probabilistic safety assessment, accident sequence precursor analysis, design evaluation and configuration management. In this paper, we focus on the application of REVEAL W to support risk-based configuration control of nuclear power plants. (author)

  18. Effects of a risk-based online mammography intervention on accuracy of perceived risk and mammography intentions.

    Science.gov (United States)

    Seitz, Holli H; Gibson, Laura; Skubisz, Christine; Forquer, Heather; Mello, Susan; Schapira, Marilyn M; Armstrong, Katrina; Cappella, Joseph N

    2016-10-01

    This experiment tested the effects of an individualized risk-based online mammography decision intervention. The intervention employs exemplification theory and the Elaboration Likelihood Model of persuasion to improve the match between breast cancer risk and mammography intentions. 2918 women ages 35-49 were stratified into two levels of 10-year breast cancer risk (<1.5%; ≥1.5%) then randomly assigned to one of eight conditions: two comparison conditions and six risk-based intervention conditions that varied according to a 2 (amount of content: brief vs. extended) x 3 (format: expository vs. untailored exemplar [example case] vs. tailored exemplar) design. Outcomes included mammography intentions and accuracy of perceived breast cancer risk. Risk-based intervention conditions improved the match between objective risk estimates and perceived risk, especially for high-numeracy women with a 10-year breast cancer risk ≤1.5%. For women with a risk≤1.5%, exemplars improved accuracy of perceived risk and all risk-based interventions increased intentions to wait until age 50 to screen. A risk-based mammography intervention improved accuracy of perceived risk and the match between objective risk estimates and mammography intentions. Interventions could be applied in online or clinical settings to help women understand risk and make mammography decisions. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  19. Sugary food and beverage consumption and epithelial ovarian cancer risk: a population-based case?control study

    OpenAIRE

    King, Melony G; Olson, Sara H; Paddock, Lisa; Chandran, Urmila; Demissie, Kitaw; Lu, Shou-En; Parekh, Niyati; Rodriguez-Rodriguez, Lorna; Bandera, Elisa V

    2013-01-01

    Background Ovarian cancer is the deadliest gynecologic cancer in the US. The consumption of refined sugars has increased dramatically over the past few decades, accounting for almost 15% of total energy intake. Yet, there is limited evidence on how sugar consumption affects ovarian cancer risk. Methods We evaluated ovarian cancer risk in relation to sugary foods and beverages, and total and added sugar intakes in a population-based case?control study. Cases were women with newly diagnosed epi...

  20. Medication use and kidney cancer risk: A population-based study.

    Science.gov (United States)

    Nayan, Madhur; Juurlink, David N; Austin, Peter C; Macdonald, Erin M; Finelli, Antonio; Kulkarni, Girish S; Hamilton, Robert J

    2017-09-01

    Exposure to commonly prescribed medications may be associated with cancer risk. However, there is limited data in kidney cancer. Furthermore, methods of classifying cumulative medication exposure in previous studies may be prone to bias. We conducted a population-based case-control study of 10,377 incident kidney cancer cases aged ≥66 years matched with 35,939 controls on age, sex, history of hypertension, comorbidity score, and geographic location. Cumulative exposure to commonly prescribed medications hypothesised to modulate cancer risk was obtained using prescription claims data. We modelled exposure in four different fashions: (1) as continuous exposures using (a) fractional polynomials (which allow for a non-linear relationship between an exposure and outcome) or (b) assuming linear relationships; and 2) as dichotomous exposures denoting (a) ≥3 years versus kidney cancer. The directions of association were relatively consistent across analyses; however, the magnitudes were sensitive to the method of analysis. When utilising fractional polynomials, increasing cumulative exposure to acetylsalicylic acid, selective serotonin reuptake inhibitors, and proton-pump inhibitors was associated with significantly reduced risk of kidney cancer, while increasing exposure to antihypertensive drugs was associated with significantly increased risk. Our study provides impetus to further explore the effect of commonly prescribed medications on carcinogenesis to identify modifiable pharmacological interventions to reduce the risk of kidney cancer. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. New approach for risk based inspection of H2S based Process Plants

    International Nuclear Information System (INIS)

    Vinod, Gopika; Sharma, Pavan K.; Santosh, T.V.; Hari Prasad, M.; Vaze, K.K.

    2014-01-01

    Highlights: • Study looks into improving the consequence evaluation in risk based inspection. • Ways to revise the quantity factors used in qualitative approach. • New approach based on computational fluid dynamics along with probit mathematics. • Demonstrated this methodology along with a suitable case study for the said issue. - Abstract: Recent trend in risk informed and risk based approaches in life management issues have certainly put the focus on developing estimation methods for real risk. Idea of employing risk as an optimising measure for in-service inspection, termed as risk based inspection, was accepted in principle from late 80s. While applying risk based inspection, consequence of failure from each component needs to be assessed. Consequence evaluation in a Process Plant is a crucial task. It may be noted that, in general, the number of components to be considered for life management is very large and hence the consequence evaluation resulting from their failures (individually) is a laborious task. Screening of critical components is usually carried out using simplified qualitative approach, which primarily uses influence factors for categorisation. This necessitates logical formulation of influence factors and their ranges with a suitable technical basis for acceptance from regulators. This paper describes application of risk based inspection for H 2 S based Process Plant along with the approach devised for handling the influence factor related to the quantity of H 2 S released

  2. Risk-based plant performance indicators

    International Nuclear Information System (INIS)

    Boccio, J.L.; Azarm, M.A.; Hall, R.E.

    1991-01-01

    Tasked by the 1979 President's Commission on the Accident at Three Mile Island, the U.S. nuclear power industry has put into place a performance indicator program as one means for showing a demonstrable record of achievement. Largely through the efforts of the Institute of Nuclear Power Operations (INPO), plant performance data has, since 1983, been collected and analyzed to aid utility management in measuring their plants' performance progress. The U.S. Nuclear Regulatory Commission (NRC) has also developed a set of performance indicators. This program, conducted by NRC's Office for the Analysis and Evaluation of Operational Data (AEOD), is structured to present information on plant operational performance in a manner that could enhance the staff's ability to recognize changes in the safety performance. Both organizations recognized that performance indicators have limitations and could be subject to misinterpretation and misuse with the potential for an adverse impact on safety. This paper reports on performance indicators presently in use, e.g., unplanned automatic scrams, unplanned safety system actuation, safety system failures, etc., which are logically related to safety. But, a reliability/risk-based method for evaluating either individual indicators or an aggregated set of indicators is not yet available

  3. Structuring a risk-based bioassay program for uranium usage in university laboratories

    Science.gov (United States)

    Dawson, Johnne Talia

    Bioassay programs are integral in a radiation safety program. They are used as a method of determining whether individuals working with radioactive material have been exposed and have received a resulting dose. For radionuclides that are not found in nature, determining an exposure is straightforward. However, for a naturally occurring radionuclide like uranium, it is not as straightforward to determine whether a dose is the result of an occupational exposure. The purpose of this project is to address this issue within the University of Nevada, Las Vegas's (UNLV) bioassay program. This project consisted of two components that studied the effectiveness of a bioassay program in determining the dose for an acute inhalation of uranium. The first component of the plan addresses the creation of excretion curves, utilizing MATLAB that would allow UNLV to be able to determine at what time an inhalation dose can be attributed to. The excretion curves were based on the ICRP 30 lung model, as well as the Annual Limit Intake (ALI) values located in the Nuclear Regulatory Commission's 10CFR20 which is based on ICRP 30 (International Commission on Radiological Protection). The excretion curves would allow UNLV to be able to conduct in-house investigations of inhalation doses without solely depending on outside investigations and sources. The second component of the project focused on the creation of a risk based bioassay program to be utilized by UNLV that would take into account bioassay frequency that depended on the individual. Determining the risk based bioassay program required the use of baseline variance in order to minimize the investigation of false positives among those individuals who undergo bioassays for uranium work. The proposed program was compared against an evaluation limit of 10 mrem per quarter, an investigational limit of 125 mrem per quarter, and the federal/state requirement of 1.25 rem per quarter. It was determined that a bioassay program whose bioassay

  4. Incentivising flood risk adaptation through risk based insurance premiums : Trade-offs between affordability and risk reduction

    NARCIS (Netherlands)

    Hudson, Paul F.; Botzen, W.J.W.; Feyen, L.; Aerts, Jeroen C.J.H.

    2016-01-01

    The financial incentives offered by the risk-based pricing of insurance can stimulate policyholder adaptation to flood risk while potentially conflicting with affordability. We examine the trade-off between risk reduction and affordability in a model of public-private flood insurance in France and

  5. 12 CFR 652.70 - Risk-based capital level.

    Science.gov (United States)

    2010-01-01

    ... risk-based capital level is the sum of the following amounts: (a) Credit and interest rate risk. The... 12 Banks and Banking 6 2010-01-01 2010-01-01 false Risk-based capital level. 652.70 Section 652.70 Banks and Banking FARM CREDIT ADMINISTRATION FARM CREDIT SYSTEM FEDERAL AGRICULTURAL MORTGAGE...

  6. A risk-based sensor placement methodology

    International Nuclear Information System (INIS)

    Lee, Ronald W.; Kulesz, James J.

    2008-01-01

    A risk-based sensor placement methodology is proposed to solve the problem of optimal location of sensors to protect population against the exposure to, and effects of, known and/or postulated chemical, biological, and/or radiological threats. Risk is calculated as a quantitative value representing population at risk from exposure at standard exposure levels. Historical meteorological data are used to characterize weather conditions as the frequency of wind speed and direction pairs. The meteorological data drive atmospheric transport and dispersion modeling of the threats, the results of which are used to calculate risk values. Sensor locations are determined via an iterative dynamic programming algorithm whereby threats detected by sensors placed in prior iterations are removed from consideration in subsequent iterations. In addition to the risk-based placement algorithm, the proposed methodology provides a quantification of the marginal utility of each additional sensor. This is the fraction of the total risk accounted for by placement of the sensor. Thus, the criteria for halting the iterative process can be the number of sensors available, a threshold marginal utility value, and/or a minimum cumulative utility achieved with all sensors

  7. Holistic stakeholder-oriented and case study-based risk analysis

    Science.gov (United States)

    Heisterkamp, Tobias

    2013-04-01

    Case studies of storm events in the Berlin conurbation demonstrate the chance of a holistic approach and its potential data sources. Data sets of population, but also data provided by insurance and transport companies, and operating data provided by fire brigades, are used. Various indicators for risk analysis are constructed to identify hot spots. These hot spots can be shortcomings or critical aspects in structure, communication, the warning chain, or even in the structure of potentially affected stakeholders or in the civil protection system itself. Due to increasing complexity of interactions and interdependencies in or between societies and nature, it is important to choose a holistic approach. For risk analyses like the storms in Berlin, it captures many important factors with their effects. For risk analyses, it is important to take potential users into concern: The analysis gets important due to its use later on. In addition to a theoretical background, a focus on the application should be set from the beginning on. To get usable results, it is helpful to complement the theoretical meta-level by a stakeholder-oriented level. An iterative investigation and combination of different layers for the risk analysis explores important influencing factors and allows a tailoring of results to different stakeholder groups. Layers are indicators, gained from data sets like losses from insurance data. Tailoring is important, because of different requirements e.g. by technical or medical assistance. Stakeholders' feedback in the iterative investigation also shows structural limitations for later applications, like special laws the fire brigades have to deal with. Additionally, using actors' perspectives offers the chance to convince practitioners of taking part in the analysis. Their participation is an essential component in applied science. They are important data suppliers, whose goodwill is needed to ensure good results. Based on their experience, they can also help

  8. Upper limits for air humidity based on human comfort

    DEFF Research Database (Denmark)

    Toftum, Jørn; Fanger, Povl Ole; Jørgensen, Anette S.

    1998-01-01

    respiratory cooling. Human subjects perceived the condition of their skin to be less acceptable with increasing skin humidity. Inhaled air was rated warmer, more stuffy and less acceptable with increasing air humidity and temperature. Based on the subjects' comfort responses, new upper limits for air humidity......The purpose of this study was to verify the hypothesis that insufficient respiratory cooling and a high level of skin humidity are two reasons for thermal discomfort at high air humidities, and to prescribe upper limits for humidity based on discomfort due to elevated skin humidity and insufficient...

  9. Risk analysis of Odelouca cofferdam

    OpenAIRE

    Pimenta, L.; Caldeira, L.; Maranha das Neves, E.

    2009-01-01

    In this paper we present the risk analysis of Odelouca Cofferdam, using an event tree analysis. The initializing events, failure modes and analysed limit states are discussed based on an influence diagram. The constructed event trees and their interpretation are presented. The obtained risk values are represented in an FN plot superimposed to the acceptability and tolerability risk limits proposed for Portuguese dams. Initially, particular emphasis is placed on the main characteristic...

  10. Water risk assessment in China based on the improved Water Risk Filter

    Science.gov (United States)

    Hong, G.; Yaqin, Q.; Qiong, L.; Cunwen, N.; Na, W.; Jiajia, L.; Jongde, G.; Na, Z.; Xiangyi, D.

    2014-09-01

    Finding an effective way to deal with the water crisis and the relationship between water and development is a major issue for all levels of government and different economic sectors across the world. Scientific understanding of water risk is the basis for achieving a scientific relationship between water and development, and water risk assessment is currently an important research focus. To effectively deal with the global water crisis, the World Wide Fund for Nature and German Investment and Development Company Limited proposed the concept of water risk and released an online Water Risk Filter in March 2012, which has been applied to at least 85 countries. To comprehensively and accurately reflect the situation of water risk in China, this study adjusts the water risk assessment indicators in the Water Risk Filter, taking the actual situation in China and the difficulty of obtaining the information about the indicators into account, and proposes an index system for water risk evaluation for China which consists of physical risk, regulatory risk and reputational risk. The improved Water Risk Filter is further used to assess the sources and causes of the water risks in 10 first-class and seven second-class water resource areas (WRAs). The results indicate that the water risk for the whole country is generally medium and low, while those for different regions in the country vary greatly, and those for southern regions are generally lower than those for northern regions. Government regulatory and policy implementation as well as media supervision in northern regions should be strengthened to reduce the water risk. The research results may provide decision support and references for both governments and industrial enterprises in identifying water risks, formulating prevention and control policies, and improving water resources management in China.

  11. Water risk assessment in China based on the improved Water Risk Filter

    Directory of Open Access Journals (Sweden)

    G. Hong

    2014-09-01

    Full Text Available Finding an effective way to deal with the water crisis and the relationship between water and development is a major issue for all levels of government and different economic sectors across the world. Scientific understanding of water risk is the basis for achieving a scientific relationship between water and development, and water risk assessment is currently an important research focus. To effectively deal with the global water crisis, the World Wide Fund for Nature and German Investment and Development Company Limited proposed the concept of water risk and released an online Water Risk Filter in March 2012, which has been applied to at least 85 countries. To comprehensively and accurately reflect the situation of water risk in China, this study adjusts the water risk assessment indicators in the Water Risk Filter, taking the actual situation in China and the difficulty of obtaining the information about the indicators into account, and proposes an index system for water risk evaluation for China which consists of physical risk, regulatory risk and reputational risk. The improved Water Risk Filter is further used to assess the sources and causes of the water risks in 10 first-class and seven second-class water resource areas (WRAs. The results indicate that the water risk for the whole country is generally medium and low, while those for different regions in the country vary greatly, and those for southern regions are generally lower than those for northern regions. Government regulatory and policy implementation as well as media supervision in northern regions should be strengthened to reduce the water risk. The research results may provide decision support and references for both governments and industrial enterprises in identifying water risks, formulating prevention and control policies, and improving water resources management in China.

  12. Risk-based performance indicators

    International Nuclear Information System (INIS)

    Azarm, M.A.; Boccio, J.L.; Vesely, W.E.; Lofgren, E.

    1987-01-01

    The purpose of risk-based indicators is to monitor plant safety. Safety is measured by monitoring the potential for core melt (core-melt frequency) and the public risk. Targets for these measures can be set consistent with NRC safety goals. In this process, the performance of safety systems, support systems, major components, and initiating events can be monitored using measures such as unavailability, failure or occurrence frequency. The changes in performance measures and their trends are determined from the time behavior of monitored measures by differentiation between stochastical and actual variations. Therefore, degradation, as well as improvement in the plant safety performance, can be determined. The development of risk-based performance indicators will also provide the means to trace a change in the safety measures to specific problem areas which are amenable to root cause analysis and inspection audits. In addition, systematic methods will be developed to identify specific improvement policies using the plant information system for the identified problem areas. The final product of the performance indicator project will be a methodology, and an integrated and validated set of software packages which, if properly interfaced with the logic model software of a plant, can monitor the plant performance as plant information is provided as input

  13. Risk-based decision making for terrorism applications.

    Science.gov (United States)

    Dillon, Robin L; Liebe, Robert M; Bestafka, Thomas

    2009-03-01

    This article describes the anti-terrorism risk-based decision aid (ARDA), a risk-based decision-making approach for prioritizing anti-terrorism measures. The ARDA model was developed as part of a larger effort to assess investments for protecting U.S. Navy assets at risk and determine whether the most effective anti-terrorism alternatives are being used to reduce the risk to the facilities and war-fighting assets. With ARDA and some support from subject matter experts, we examine thousands of scenarios composed of 15 attack modes against 160 facility types on two installations and hundreds of portfolios of 22 mitigation alternatives. ARDA uses multiattribute utility theory to solve some of the commonly identified challenges in security risk analysis. This article describes the process and documents lessons learned from applying the ARDA model for this application.

  14. Strategies and criteria for risk-based configuration control

    International Nuclear Information System (INIS)

    Samanta, P.K.; Kim, I.S.; Vesely, W.E.

    1991-01-01

    A configuration, as used here, is a set of component operability or statuses that define the state of a nuclear power plant. Risk-based configuration control is the management of component configurations using a risk perspective to control risk and assure safety. If the component configurations that have high risk implications do not occur then the risk from the operation of nuclear power plants would be minimal. The control of component configurations, i.e., the management of component statuses, so that the risk from components being unavailable is minimized, becomes difficult because the status of a standby safety system component is often not apparent unless it is tested. In this paper, we discuss the strategies and criteria for risk-based configuration control in nuclear power plants. In developing these strategies and criteria, the primary objective is to obtain more direct risk control but the added benefit is the effective use of plant resources. Implementation of such approaches can result in replacement/modification of parts of Technical Specifications. Specifically, the risk impact or safety impact of a configuration depends upon four factors: (1) The configuration components which are simultaneously down (i.e., inoperable); (2) the backup components which are known to be up (i.e., operable); (3) the duration of time the configuration exists (the outage time); and (4) the frequency at which the configuration occurs. Risk-based configuration control involves managing these factors using risk analyses and risk insights. In this paper, we discuss each of the factors and illustrate how they can be controlled. The information and the tools needed in implementing configuration control are also discussed. The risk-based calculation requirements in achieving the control are also delineated. 4 refs., 4 figs., 1 tab

  15. A theory-based approach to understanding suicide risk in shelter-seeking women.

    Science.gov (United States)

    Wolford-Clevenger, Caitlin; Smith, Phillip N

    2015-04-01

    Women seeking shelter from intimate partner violence are at an increased risk for suicide ideation and attempts compared to women in the general population. Control-based violence, which is common among shelter-seeking women, may play a pivotal role in the development of suicide ideation and attempts. Current risk assessment and management practices for shelter-seeking women are limited by the lack of an empirically grounded understanding of increased risk in this population. We argue that in order to more effectively promote risk assessment and management, an empirically supported theory that is sensitive to the experiences of shelter-seeking women is needed. Such a theory-driven approach has the benefits of identifying and prioritizing targetable areas for intervention. Here, we review the evidence for the link between coercive control and suicide ideation and attempts from the perspective of Baumeister's escape theory of suicide. This theory has the potential to explain the role of coercive control in the development of suicide ideation and eventual attempts in shelter-seeking women. Implications for suicide risk assessment and prevention in domestic violence shelters are discussed. © The Author(s) 2014.

  16. Risk-based decision making and risk management of European Union regional programs

    Directory of Open Access Journals (Sweden)

    Michalopoulos Evangelos

    2008-01-01

    Full Text Available This paper presents a generalized method for management decision making incorporating risk assessment techniques. The risk based decision making methodology is applied to European Union expenditure programs used to implement its regional policy, such as the community support framework, community initiatives, special initiatives and other European policies. An example is presented for the development of an audit (inspection program in the region of West Macedonia, Greece, during the implementation of the 3rd Community Structural Support Framework Operational Program. The generic nature of the method permits its use in the management of similar European regional programs in Greece and other European countries. It is also applicable to many other industries interested in applying risk-based management decisions to physical or process based systems. .

  17. Risk limitation, safety and environmental compatibility in electricity generation

    International Nuclear Information System (INIS)

    Angelini, A.M.

    1981-01-01

    The purpose of this paper is to present the problem of meeting future electricity needs while at the same time reducing to a minimum the risks, the pollution of air and water and the environmental effects of power stations. The first resource to exploit is the ''virtual source'' represented by energy saving pursued to the limit of the possible. The second, in order of priority, is that of renewable resources as yet unused and under development. Unfortunately, in most countries these latter resources are far from sufficient: it is then necessary to choose between the use of conventional fossil fuels and nuclear fuels. In this paper it is shown that, of all the possible fossil fuels, only coal can be considered for electricity production. As a result, in meeting new electricity needs, the choice will have to be made between coal and nuclear power. Attention is directed to factors having a significant influence on this choice, particularly the risks and safety problems in the widest sense, with a view to making a global evaluation comprising not just generating stations but the entire production cycle, from the search for the primary source to the supplying of electricity to the user. The most important problems that arise in this connection are briefly analysed in the paper, which concludes with an appeal for more objectivity in providing information on energy, such information being at present very ''polluted'' and exerting a major influence on the views of experts. (author)

  18. Limits of Spalling of Fire-Exposed Concrete

    DEFF Research Database (Denmark)

    Hertz, Kristian Dahl

    2003-01-01

    on the nature of spalling, add the latest findings from the research of the author, and derives limits within which spalling should not take place. Some guidelines are formulated based on experience from research and practise for reducing the spalling risk for constructions beyond the safe design limits....... The limits provided are those, which can be stated at present, but further research is in progress, identifying more precisely the range of materials susceptible to spalling and contributing to the full understanding of the phenomenon....

  19. Efficacy of a virtual assistance-based lifestyle intervention in reducing risk factors for Type 2 diabetes in young employees in the information technology industry in India: LIMIT, a randomized controlled trial.

    Science.gov (United States)

    Limaye, T; Kumaran, K; Joglekar, C; Bhat, D; Kulkarni, R; Nanivadekar, A; Yajnik, C

    2017-04-01

    To investigate a virtual assistance-based lifestyle intervention to reduce risk factors for Type 2 diabetes in young employees in the information technology industry in India. LIMIT (Lifestyle Modification in Information Technology) was a parallel-group, partially blinded, randomized controlled trial. Employees in the information technology industry with ≥3 risk factors (family history of cardiometabolic disease, overweight/obesity, high blood pressure, impaired fasting glucose, hypertriglyceridaemia, high LDL cholesterol and low HDL cholesterol) from two industries were randomized to a control or an intervention (1:1) group. After initial lifestyle advice, the intervention group additionally received reinforcement through mobile phone messages (three per week) and e-mails (two per week) for 1 year. The primary outcome was change in prevalence of overweight/obesity, analysed by intention to treat. Of 437 employees screened (mean age 36.2 ± 9.3 years; 74.8% men), 265 (61.0%) were eligible and randomized into control (n=132) or intervention (n=133) group. After 1 year, the prevalence of overweight/obesity reduced by 6.0% in the intervention group and increased by 6.8% in the control group (risk difference 11.2%; 95% CI 1.2-21.1; P=0.042). There were also significant improvements in lifestyle measurements, waist circumference, and total and LDL cholesterol in the intervention group. The number-needed-to-treat to prevent one case of overweight/obesity in 1 year was 9 (95% CI 5-82), with an incremental cost of INR10665 (£112.30) per case treated/prevented. A total of 98% of participants found the intervention acceptable. A virtual assistance-based lifestyle intervention was effective, cost-effective and acceptable in reducing risk factors for diabetes in young employees in the information technology industry, and is potentially scalable. © 2016 Diabetes UK.

  20. COMPETENCY-BASED TRAINING IN NURSING: LIMITS AND POSSIBILITIES

    Directory of Open Access Journals (Sweden)

    Silvia Franco da Rocha Tonhom

    2014-12-01

    Full Text Available Objective To analyze the possibilities and limits of competency-based training in nursing. Method An integrative review of the literature on the subject was carried out, and an analysis was made of the results of a survey evaluating a nursing course based on areas of competency. A dialog was then established between the review and the results of the research. Results On the question of which theoretical type of competency the articles from the literature relate to, there is a predominance of the constructivist perspective, followed by the functionalist approach and the dialog-based approach. In the dialog between the literature and the research, limits and possibilities were observed in the development of a training by areas of competency. Conclusion The dialog-based approach to competency is the proposition that most approximates to the profile defined by the National Curriculum Guidelines for training in nursing, and this was also identified in the evaluation survey that was studied. However, it is found that there are aspects on better work is needed, such as: partnership between school and the workplace, the role of the teacher, the role of the student, and the process of evaluation.

  1. The API methodology for risk-based inspection (RBI) analysis for the petroleum and petrochemical industry

    International Nuclear Information System (INIS)

    Reynolds, J.T.

    1998-01-01

    Twenty-one petroleum and petrochemical companies are currently sponsoring a project within the American Petroleum Institute (API) to develop risk-based inspection (RBI) methodology for application in the refining and petrochemical industry. This paper describes that particular RBI methodology and provides a summary of the three levels of RBI analysis developed by the project. Also included is a review of the first pilot project to validate the methodology by applying RBI to several existing refining units. The failure for pressure equipment in a process unit can have several undesirable effects. For the purpose of RBI analysis, the API RBI program categorizes these effects into four basic risk outcomes: flammable events, toxic releases, major environmental damage, and business interruption losses. API RBI is a strategic process, both qualitative and quantitative, for understanding and reducing these risks associated with operating pressure equipment. This paper will show how API RBI assesses the potential consequences of a failure of the pressure boundary, as well as assessing the likelihood (probability) of failure. Risk-based inspection also prioritizes risk levels in a systematic manner so that the owner-user can then plan an inspection program that focuses more resources on the higher risk equipment; while possibly saving inspection resources that are not doing an effective job of reducing risk. At the same time, if consequence of failure is a significant driving force for high risk equipment items, plant management also has the option of applying consequence mitigation steps to minimize the impact of a hazardous release, should one occur. The target audience for this paper is engineers, inspectors, and managers who want to understand what API Risk-Based Inspection is all about, what are the benefits and limitations of RBI, and how inspection practices can be changed to reduce risks and/or save costs without impacting safety risk. (Author)

  2. 12 CFR 932.3 - Risk-based capital requirement.

    Science.gov (United States)

    2010-01-01

    ... credit risk capital requirement, its market risk capital requirement, and its operations risk capital... 12 Banks and Banking 7 2010-01-01 2010-01-01 false Risk-based capital requirement. 932.3 Section 932.3 Banks and Banking FEDERAL HOUSING FINANCE BOARD FEDERAL HOME LOAN BANK RISK MANAGEMENT AND...

  3. Can Diet and Physical Activity Limit Alzheimer's Disease Risk?

    Science.gov (United States)

    Rege, Shraddha D; Geetha, Thangiah; Broderick, Tom L; Babu, Jeganathan Ramesh

    2017-01-01

    Alzheimer's disease (AD) is a progressive neurodegenerative disease affecting elderly individuals at an alarming rate. It has become a global health crisis imposing tremendous social and economic burden on society. Although there is no cure for AD, it is important to identify and implement preventive strategies that may delay or prevent the symptoms, limit the burden, and improve the quality of life of those afflicted. Adequate nutrition and physical activity are the two potential lifestyle modifiable factors that have gained considerable interest for their potential in the prevention or management of this challenging disease. In this review, we discuss the beneficial effects of physical activity and adequate nutrition on minimizing the risk of developing AD. The research question was initially formulated in a structured and explicit way. Relevant studies were identified using a wide range of scientific databases. Their potential relevance was based on the criteria for inclusion and exclusion. The quality of selected studies was subjected to a more precise quality assessment using standard tools. A detailed description of the implemented intervention and how it differed from what the control group received was outlined. The effects of intervention on measurable outcomes for the study sample were applied. One hundred and sixty-four references were included in the review comprising of epidemiological, longitudinal, cross-sectional, intervention and randomized controlled studies. This review highlighted the effect of various nutrient diet supplements on cognitive performance in humans as well as animals with AD and mild cognitive impairment (MCI). Moreover, the effect of physical exercise on the cognitive function in animal models with AD was outlined. The findings of this review highlight the therapeutic potential of combination of nutritionally adequate diet and physical activity in preventing or delaying the symptoms associated with AD pathology.

  4. Selecting a risk-based tool to aid in decision making

    Energy Technology Data Exchange (ETDEWEB)

    Bendure, A.O.

    1995-03-01

    Selecting a risk-based tool to aid in decision making is as much of a challenge as properly using the tool once it has been selected. Failure to consider customer and stakeholder requirements and the technical bases and differences in risk-based decision making tools will produce confounding and/or politically unacceptable results when the tool is used. Selecting a risk-based decisionmaking tool must therefore be undertaken with the same, if not greater, rigor than the use of the tool once it is selected. This paper presents a process for selecting a risk-based tool appropriate to a set of prioritization or resource allocation tasks, discusses the results of applying the process to four risk-based decision-making tools, and identifies the ``musts`` for successful selection and implementation of a risk-based tool to aid in decision making.

  5. Risk Classification and Risk-based Safety and Mission Assurance

    Science.gov (United States)

    Leitner, Jesse A.

    2014-01-01

    Recent activities to revamp and emphasize the need to streamline processes and activities for Class D missions across the agency have led to various interpretations of Class D, including the lumping of a variety of low-cost projects into Class D. Sometimes terms such as Class D minus are used. In this presentation, mission risk classifications will be traced to official requirements and definitions as a measure to ensure that projects and programs align with the guidance and requirements that are commensurate for their defined risk posture. As part of this, the full suite of risk classifications, formal and informal will be defined, followed by an introduction to the new GPR 8705.4 that is currently under review.GPR 8705.4 lays out guidance for the mission success activities performed at the Classes A-D for NPR 7120.5 projects as well as for projects not under NPR 7120.5. Furthermore, the trends in stepping from Class A into higher risk posture classifications will be discussed. The talk will conclude with a discussion about risk-based safety and mission assuranceat GSFC.

  6. Patient clusters in acute, work-related back pain based on patterns of disability risk factors.

    Science.gov (United States)

    Shaw, William S; Pransky, Glenn; Patterson, William; Linton, Steven J; Winters, Thomas

    2007-02-01

    To identify subgroups of patients with work-related back pain based on disability risk factors. Patients with work-related back pain (N = 528) completed a 16-item questionnaire of potential disability risk factors before their initial medical evaluation. Outcomes of pain, functional limitation, and work disability were assessed 1 and 3 months later. A K-Means cluster analysis of 5 disability risk factors (pain, depressed mood, fear avoidant beliefs, work inflexibility, and poor expectations for recovery) resulted in 4 sub-groups: low risk (n = 182); emotional distress (n = 103); severe pain/fear avoidant (n = 102); and concerns about job accommodation (n = 141). Pain and disability outcomes at follow-up were superior in the low-risk group and poorest in the severe pain/fear avoidant group. Patients with acute back pain can be discriminated into subgroups depending on whether disability is related to pain beliefs, emotional distress, or workplace concerns.

  7. Study of operational risk-based configuration control

    Energy Technology Data Exchange (ETDEWEB)

    Vesely, W E [Science Applications International Corp., Dublin, OH (United States); Samanta, P K; Kim, I S [Brookhaven National Lab., Upton, NY (United States)

    1991-08-01

    This report studies aspects of a risk-based configuration control system to detect and control plant configurations from a risk perspective. Configuration control, as the term is used here, is the management of component configurations to achieve specific objectives. One important objective is to control risk and safety. Another is to operate efficiently and make effective use of available resources. PSA-based evaluations are performed to study configuration to core-melt frequency and core-melt probability for two plants. Some equipment configurations can cause large core-melt frequency and there are a number of such configurations that are not currently controlled by technical specifications. However, the expected frequency of occurrence of the impacting configurations is small and the core-melt probability contributions are also generally small. The insights from this evaluation are used to develop the framework for an effective risk-based configuration control system. The focal points of such a system and the requirements for tools development for implementing the system are defined. The requirements of risk models needed for the system, and the uses of plant-specific data are also discussed. 18 refs., 25 figs., 10 tabs.

  8. III: Use of biomarkers as Risk Indicators in Environmental Risk Assessment of oil based discharges offshore.

    Science.gov (United States)

    Sanni, Steinar; Lyng, Emily; Pampanin, Daniela M

    2017-06-01

    Offshore oil and gas activities are required not to cause adverse environmental effects, and risk based management has been established to meet environmental standards. In some risk assessment schemes, Risk Indicators (RIs) are parameters to monitor the development of risk affecting factors. RIs have not yet been established in the Environmental Risk Assessment procedures for management of oil based discharges offshore. This paper evaluates the usefulness of biomarkers as RIs, based on their properties, existing laboratory biomarker data and assessment methods. Data shows several correlations between oil concentrations and biomarker responses, and assessment principles exist that qualify biomarkers for integration into risk procedures. Different ways that these existing biomarkers and methods can be applied as RIs in a probabilistic risk assessment system when linked with whole organism responses are discussed. This can be a useful approach to integrate biomarkers into probabilistic risk assessment related to oil based discharges, representing a potential supplement to information that biomarkers already provide about environmental impact and risk related to these kind of discharges. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Risk-based Regulatory Evaluation Program methodology

    International Nuclear Information System (INIS)

    DuCharme, A.R.; Sanders, G.A.; Carlson, D.D.; Asselin, S.V.

    1987-01-01

    The objectives of this DOE-supported Regulatory Evaluation Progrwam are to analyze and evaluate the safety importance and economic significance of existing regulatory guidance in order to assist in the improvement of the regulatory process for current generation and future design reactors. A risk-based cost-benefit methodology was developed to evaluate the safety benefit and cost of specific regulations or Standard Review Plan sections. Risk-based methods can be used in lieu of or in combination with deterministic methods in developing regulatory requirements and reaching regulatory decisions

  10. Study of a risk-based piping inspection guideline system.

    Science.gov (United States)

    Tien, Shiaw-Wen; Hwang, Wen-Tsung; Tsai, Chih-Hung

    2007-02-01

    A risk-based inspection system and a piping inspection guideline model were developed in this study. The research procedure consists of two parts--the building of a risk-based inspection model for piping and the construction of a risk-based piping inspection guideline model. Field visits at the plant were conducted to develop the risk-based inspection and strategic analysis system. A knowledge-based model had been built in accordance with international standards and local government regulations, and the rational unified process was applied for reducing the discrepancy in the development of the models. The models had been designed to analyze damage factors, damage models, and potential damage positions of piping in the petrochemical plants. The purpose of this study was to provide inspection-related personnel with the optimal planning tools for piping inspections, hence, to enable effective predictions of potential piping risks and to enhance the better degree of safety in plant operations that the petrochemical industries can be expected to achieve. A risk analysis was conducted on the piping system of a petrochemical plant. The outcome indicated that most of the risks resulted from a small number of pipelines.

  11. Self-organizing maps based on limit cycle attractors.

    Science.gov (United States)

    Huang, Di-Wei; Gentili, Rodolphe J; Reggia, James A

    2015-03-01

    Recent efforts to develop large-scale brain and neurocognitive architectures have paid relatively little attention to the use of self-organizing maps (SOMs). Part of the reason for this is that most conventional SOMs use a static encoding representation: each input pattern or sequence is effectively represented as a fixed point activation pattern in the map layer, something that is inconsistent with the rhythmic oscillatory activity observed in the brain. Here we develop and study an alternative encoding scheme that instead uses sparsely-coded limit cycles to represent external input patterns/sequences. We establish conditions under which learned limit cycle representations arise reliably and dominate the dynamics in a SOM. These limit cycles tend to be relatively unique for different inputs, robust to perturbations, and fairly insensitive to timing. In spite of the continually changing activity in the map layer when a limit cycle representation is used, map formation continues to occur reliably. In a two-SOM architecture where each SOM represents a different sensory modality, we also show that after learning, limit cycles in one SOM can correctly evoke corresponding limit cycles in the other, and thus there is the potential for multi-SOM systems using limit cycles to work effectively as hetero-associative memories. While the results presented here are only first steps, they establish the viability of SOM models based on limit cycle activity patterns, and suggest that such models merit further study. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. Feasibility assessment of a risk-based approach to technical specifications

    International Nuclear Information System (INIS)

    Atefi, B.; Gallagher, D.W.

    1991-05-01

    To assess the potential use of risk and reliability techniques for improving the effectiveness of the technical specifications to control plant operational risk, the Technical Specifications Branch of the Nuclear Regulatory Commission initiated an effort to identify and evaluate alternative risk-based approaches that could bring greater risk perspective to these requirements. In the first phase four alternative approaches were identified and their characteristics were analyzed. Among these, the risk-based approach to technical specifications is the most promising approach for controlling plant operational risk using technical specifications. The second phase of the study concentrated on detailed characteristics of the real time risk-based approach. It is concluded that a real time risk-based approach to technical specifications has the potential to improve both plant safety and availability. 33 figs., 5 figs., 6 tabs

  13. Risk-based rules for crane safety systems

    Energy Technology Data Exchange (ETDEWEB)

    Ruud, Stian [Section for Control Systems, DNV Maritime, 1322 Hovik (Norway)], E-mail: Stian.Ruud@dnv.com; Mikkelsen, Age [Section for Lifting Appliances, DNV Maritime, 1322 Hovik (Norway)], E-mail: Age.Mikkelsen@dnv.com

    2008-09-15

    The International Maritime Organisation (IMO) has recommended a method called formal safety assessment (FSA) for future development of rules and regulations. The FSA method has been applied in a pilot research project for development of risk-based rules and functional requirements for systems and components for offshore crane systems. This paper reports some developments in the project. A method for estimating target reliability for the risk-control options (safety functions) by means of the cost/benefit decision criterion has been developed in the project and is presented in this paper. Finally, a structure for risk-based rules is proposed and presented.

  14. Risk-based rules for crane safety systems

    International Nuclear Information System (INIS)

    Ruud, Stian; Mikkelsen, Age

    2008-01-01

    The International Maritime Organisation (IMO) has recommended a method called formal safety assessment (FSA) for future development of rules and regulations. The FSA method has been applied in a pilot research project for development of risk-based rules and functional requirements for systems and components for offshore crane systems. This paper reports some developments in the project. A method for estimating target reliability for the risk-control options (safety functions) by means of the cost/benefit decision criterion has been developed in the project and is presented in this paper. Finally, a structure for risk-based rules is proposed and presented

  15. Event-based historical value-at-risk

    NARCIS (Netherlands)

    Hogenboom, F.P.; Winter, Michael; Hogenboom, A.C.; Jansen, Milan; Frasincar, F.; Kaymak, U.

    2012-01-01

    Value-at-Risk (VaR) is an important tool to assess portfolio risk. When calculating VaR based on historical stock return data, we hypothesize that this historical data is sensitive to outliers caused by news events in the sampled period. In this paper, we research whether the VaR accuracy can be

  16. Risk-based audit selection of dairy farms.

    Science.gov (United States)

    van Asseldonk, M A P M; Velthuis, A G J

    2014-02-01

    Dairy farms are audited in the Netherlands on numerous process standards. Each farm is audited once every 2 years. Increasing demands for cost-effectiveness in farm audits can be met by introducing risk-based principles. This implies targeting subpopulations with a higher risk of poor process standards. To select farms for an audit that present higher risks, a statistical analysis was conducted to test the relationship between the outcome of farm audits and bulk milk laboratory results before the audit. The analysis comprised 28,358 farm audits and all conducted laboratory tests of bulk milk samples 12 mo before the audit. The overall outcome of each farm audit was classified as approved or rejected. Laboratory results included somatic cell count (SCC), total bacterial count (TBC), antimicrobial drug residues (ADR), level of butyric acid spores (BAB), freezing point depression (FPD), level of free fatty acids (FFA), and cleanliness of the milk (CLN). The bulk milk laboratory results were significantly related to audit outcomes. Rejected audits are likely to occur on dairy farms with higher mean levels of SCC, TBC, ADR, and BAB. Moreover, in a multivariable model, maxima for TBC, SCC, and FPD as well as standard deviations for TBC and FPD are risk factors for negative audit outcomes. The efficiency curve of a risk-based selection approach, on the basis of the derived regression results, dominated the current random selection approach. To capture 25, 50, or 75% of the population with poor process standards (i.e., audit outcome of rejected), respectively, only 8, 20, or 47% of the population had to be sampled based on a risk-based selection approach. Milk quality information can thus be used to preselect high-risk farms to be audited more frequently. Copyright © 2014 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  17. Laboratory-based and office-based risk scores and charts to predict 10-year risk of cardiovascular disease in 182 countries

    DEFF Research Database (Denmark)

    Ueda, Peter; Woodward, Mark; Lu, Yuan

    2017-01-01

    BACKGROUND: Worldwide implementation of risk-based cardiovascular disease (CVD) prevention requires risk prediction tools that are contemporarily recalibrated for the target country and can be used where laboratory measurements are unavailable. We present two cardiovascular risk scores, with and ...

  18. Risk assessment, eradication, and biological control: global efforts to limit Australian acacia invasions

    Science.gov (United States)

    Wilson, John R.U.; Gairifo, Carla; Gibson, Michelle R.; Arianoutsou, Margarita; Bakar, Baki B.; Baret, Stephane; Celesti-Grapow, Laura; DiTomaso, Joseph M.; Dufour-Dror, Jean-Marc; Kueffer, Christoph; Kull, Christian A.; Hoffman, John H.; Impson, Fiona A.C.; Loope, Lloyd L.; Marchante, Elizabete; Harchante, Helia; Moore, Joslin L.; Murphy, Daniel J.; Tassin, Jacques; Witt, Arne; Zenni, Rafael D.; Richardson, David M.

    2011-01-01

    Aim Many Australian Acacia species have been planted around the world, some are highly valued, some are invasive, and some are both highly valued and invasive. We review global efforts to minimize the risk and limit the impact of invasions in this widely used plant group. Location Global. Methods Using information from literature sources, knowledge and experience of the authors, and the responses from a questionnaire sent to experts around the world, we reviewed: (1) a generalized life cycle of Australian acacias and how to control each life stage, (2) different management approaches and (3) what is required to help limit or prevent invasions. Results Relatively few Australian acacias have been introduced in large numbers, but all species with a long and extensive history of planting have become invasive somewhere. Australian acacias, as a group, have a high risk of becoming invasive and causing significant impacts as determined by existing assessment schemes. Moreover, in most situations, long-lived seed banks mean it is very difficult to control established infestations. Control has focused almost exclusively on widespread invaders, and eradication has rarely been attempted. Classical biological control is being used in South Africa with increasing success. Main conclusions A greater emphasis on pro-active rather than reactive management is required given the difficulties managing established invasions of Australian acacias. Adverse effects of proposed new introductions can be minimized by conducting detailed risk assessments in advance, planning for on-going monitoring and management, and ensuring resources are in place for long-term mitigation. Benign alternatives (e.g. sterile hybrids) could be developed to replace existing utilized taxa. Eradication should be set as a management goal more often to reduce the invasion debt. Introducing classical biological control agents that have a successful track-record in South Africa to other regions and identifying new

  19. A Knowledge-Based Model of Audit Risk

    OpenAIRE

    Dhar, Vasant; Lewis, Barry; Peters, James

    1988-01-01

    Within the academic and professional auditing communities, there has been growing concern about how to accurately assess the various risks associated with performing an audit. These risks are difficult to conceptualize in terms of numeric estimates. This article discusses the development of a prototype computational model (computer program) that assesses one of the major audit risks -- inherent risk. This program bases most of its inferencing activities on a qualitative model of a typical bus...

  20. A discussion of the limitations of the psychometric and cultural theory approaches to risk perception

    International Nuclear Information System (INIS)

    Sjoeberg, L.

    1996-01-01

    Risk perception has traditionally been conceived as a cognitive phenomenon, basically a question of information processing. The very term perception suggests that information processing is involved and of crucial importance. Kahneman and Tversky suggested that the use of 'heuristics' in the intuitive estimation of probabilities accounts for biased probability perception, hence claiming to explain risk perception as well. The psychometric approach of Slovic et al, a further step in in the cognitive tradition, conceives of perceived risk as a function of general properties of a hazard. However, the psychometric approach is shown here to explain only about 20% of the variance of perceived risk, even less of risk acceptability. Its claim to explanatory power is based on a statistical illusion: mean values were investigated and accounted for, across hazards. A currently popular alternative to the psychometric tradition, Cultural Theory, is even less successful and explains only about 5% of the variance of perceived risk. The claims of this approach were also based on a statistical illusion: 'significant' results were reported and interpreted as being of substantial importance. The present paper presents a new approach: attitude to the risk generating technology, general sensitivity to risks and specific risk explained well over 60% of the variance of perceived risk of nuclear waste, in a study of extensive data from a representative sample of the Swedish population. The attitude component functioning as an explanatory factor of perceived risk, rather than as a consequence of perceived risk, suggests strongly that perceived risk is something other than cognition. Implications for risk communication are discussed. (author)

  1. Quality assurance of nuclear analytical techniques based on Bayesian characteristic limits

    International Nuclear Information System (INIS)

    Michel, R.

    2000-01-01

    Based on Bayesian statistics, characteristic limits such as decision threshold, detection limit and confidence limits can be calculated taking into account all sources of experimental uncertainties. This approach separates the complete evaluation of a measurement according to the ISO Guide to the Expression of Uncertainty in Measurement from the determination of the characteristic limits. Using the principle of maximum entropy the characteristic limits are determined from the complete standard uncertainty of the measurand. (author)

  2. Risk-Based Operation and Maintenance of Offshore Wind Turbines using Bayesian Networks

    DEFF Research Database (Denmark)

    Nielsen, Jannie Jessen; Sørensen, John Dalsgaard

    2011-01-01

    the lifetime. Two different approaches are used; one uses a threshold value of the failure probability, and one uses a Limited Memory Influence Diagram. Both methods are tested for an application example using MonteCarlo sampling, and they are both found to be efficient and equally good.......For offshore wind farms, the costs due to operation and maintenance are large, and more optimal planning has the potential of reducing these costs. This paper presents how Bayesian networks can be used for risk-based inspection planning, where the inspection plans are updated each year through...

  3. Risk based rulemaking and design - Proceed with caution

    DEFF Research Database (Denmark)

    Zachariadis, Panos; Psaraftis, Harilaos N.; Kontovas, Christos A.

    2007-01-01

    The trend towards a risk based regulatory framework at IMO and within classification societies is expanding while some voices claim that a full ship risk based scantlings design approach can be immediately implementable. This paper attempts to clarify some widely used, but confusing to many, noti...

  4. Generalized Fragility Relationships with Local Site Conditions for Probabilistic Performance-based Seismic Risk Assessment of Bridge Inventories

    Directory of Open Access Journals (Sweden)

    Sivathayalan S.

    2012-01-01

    Full Text Available The current practice of detailed seismic risk assessment cannot be easily applied to all the bridges in a large transportation networks due to limited resources. This paper presents a new approach for seismic risk assessment of large bridge inventories in a city or national bridge network based on the framework of probabilistic performance based seismic risk assessment. To account for the influences of local site effects, a procedure to generate site-specific hazard curves that includes seismic hazard microzonation information has been developed for seismic risk assessment of bridge inventories. Simulated ground motions compatible with the site specific seismic hazard are used as input excitations in nonlinear time history analysis of representative bridges for calibration. A normalizing procedure to obtain generalized fragility relationships in terms of structural characteristic parameters of bridge span and size and longitudinal and transverse reinforcement ratios is presented. The seismic risk of bridges in a large inventory can then be easily evaluated using the normalized fragility relationships without the requirement of carrying out detailed nonlinear time history analysis.

  5. Weather based risks and insurances for agricultural production

    Science.gov (United States)

    Gobin, Anne

    2015-04-01

    Extreme weather events such as frost, drought, heat waves and rain storms can have devastating effects on cropping systems. According to both the agriculture and finance sectors, a risk assessment of extreme weather events and their impact on cropping systems is needed. The principle of return periods or frequencies of natural hazards is adopted in many countries as the basis of eligibility for the compensation of associated losses. For adequate risk management and eligibility, hazard maps for events with a 20-year return period are often used. Damages due to extreme events are strongly dependent on crop type, crop stage, soil type and soil conditions. The impact of extreme weather events particularly during the sensitive periods of the farming calendar therefore requires a modelling approach to capture the mixture of non-linear interactions between the crop, its environment and the occurrence of the meteorological event in the farming calendar. Physically based crop models such as REGCROP (Gobin, 2010) assist in understanding the links between different factors causing crop damage. Subsequent examination of the frequency, magnitude and impacts of frost, drought, heat stress and soil moisture stress in relation to the cropping season and crop sensitive stages allows for risk profiles to be confronted with yields, yield losses and insurance claims. The methodology is demonstrated for arable food crops, bio-energy crops and fruit. The perspective of rising risk-exposure is exacerbated further by limited aid received for agricultural damage, an overall reduction of direct income support to farmers and projected intensification of weather extremes with climate change. Though average yields have risen continuously due to technological advances, there is no evidence that relative tolerance to adverse weather events has improved. The research is funded by the Belgian Science Policy Organisation (Belspo) under contract nr SD/RI/03A.

  6. Integrating pixel- and polygon-based approaches to wildfire risk assessment: Application to a high-value watershed on the Pike and San Isabel National Forests, Colorado, USA

    Science.gov (United States)

    Matthew P. Thompson; Julie W. Gilbertson-Day; Joe H. Scott

    2015-01-01

    We develop a novel risk assessment approach that integrates complementary, yet distinct, spatial modeling approaches currently used in wildfire risk assessment. Motivation for this work stems largely from limitations of existing stochastic wildfire simulation systems, which can generate pixel-based outputs of fire behavior as well as polygon-based outputs of simulated...

  7. 12 CFR Appendix B to Part 3 - Risk-Based Capital Guidelines; Market Risk Adjustment

    Science.gov (United States)

    2010-01-01

    ...) The bank must have a risk control unit that reports directly to senior management and is independent... management systems at least annually. (c) Market risk factors. The bank's internal model must use risk.... Section 4. Internal Models (a) General. For risk-based capital purposes, a bank subject to this appendix...

  8. Ontology-based specification, identification and analysis of perioperative risks.

    Science.gov (United States)

    Uciteli, Alexandr; Neumann, Juliane; Tahar, Kais; Saleh, Kutaiba; Stucke, Stephan; Faulbrück-Röhr, Sebastian; Kaeding, André; Specht, Martin; Schmidt, Tobias; Neumuth, Thomas; Besting, Andreas; Stegemann, Dominik; Portheine, Frank; Herre, Heinrich

    2017-09-06

    Medical personnel in hospitals often works under great physical and mental strain. In medical decision-making, errors can never be completely ruled out. Several studies have shown that between 50 and 60% of adverse events could have been avoided through better organization, more attention or more effective security procedures. Critical situations especially arise during interdisciplinary collaboration and the use of complex medical technology, for example during surgical interventions and in perioperative settings (the period of time before, during and after surgical intervention). In this paper, we present an ontology and an ontology-based software system, which can identify risks across medical processes and supports the avoidance of errors in particular in the perioperative setting. We developed a practicable definition of the risk notion, which is easily understandable by the medical staff and is usable for the software tools. Based on this definition, we developed a Risk Identification Ontology (RIO) and used it for the specification and the identification of perioperative risks. An agent system was developed, which gathers risk-relevant data during the whole perioperative treatment process from various sources and provides it for risk identification and analysis in a centralized fashion. The results of such an analysis are provided to the medical personnel in form of context-sensitive hints and alerts. For the identification of the ontologically specified risks, we developed an ontology-based software module, called Ontology-based Risk Detector (OntoRiDe). About 20 risks relating to cochlear implantation (CI) have already been implemented. Comprehensive testing has indicated the correctness of the data acquisition, risk identification and analysis components, as well as the web-based visualization of results.

  9. Limited clinical efficacy of azacitidine in transfusion-dependent, growth factor-resistant, low- and Int-1-risk MDS

    DEFF Research Database (Denmark)

    Holm, Mette; Dybedahl, I; Holm, Mette

    2014-01-01

    This prospective phase II study evaluated the efficacy of azacitidine (Aza)+erythropoietin (Epo) in transfusion-dependent patients with lower-risk myelodysplastic syndrome (MDS). Patients ineligible for or refractory to full-dose Epo+granulocyte colony stimulation factors for >8 weeks and a trans...... patients, but efficacy is limited, toxicity substantial and most responses of short duration. This treatment cannot be generally recommended in lower-risk MDS. Mutational screening revealed a high frequency of mutations....

  10. Environmental risk limits for zinc

    NARCIS (Netherlands)

    Bodar CWM; SEC

    2007-01-01

    Environmental Riks Limits (ERLs) were derived for zinc. ERLs serve as advisory values to set environmental quality standards in the Netherlands. The ERLs for zinc closely follow the outcomes of earlier discussions on zinc within the Water Framework Directive and EC Regulation 793/93. The ERLs

  11. Environmental risk limits for zinc

    NARCIS (Netherlands)

    Bodar CWM; SEC

    2007-01-01

    Environmental Riks Limits (ERLs) were derived for zinc. ERLs serve as advisory values to set environmental quality standards in the Netherlands. The ERLs for zinc closely follow the outcomes of earlier discussions on zinc within the Water Framework Directive and EC Regulation 793/93. The ERLs refer

  12. Heat transfer calculations for the High Flux Isotope Reactor (HFIR). Technical specifications: bases for safety limits and limiting safety system settings

    International Nuclear Information System (INIS)

    Sims, T.M.; Swanks, J.H.

    1977-09-01

    Heat transfer analyses, in support of the preparation of the HFIR technical specifications, were made to establish the bases for the safety limits and limiting safety system settings applicable to the HFIR. The results of these analyses, along with the detailed bases, are presented

  13. A Risk Metric Assessment of Scenario-Based Market Risk Measures for Volatility and Risk Estimation: Evidence from Emerging Markets

    Directory of Open Access Journals (Sweden)

    Sitima Innocent

    2015-03-01

    Full Text Available The study evaluated the sensitivity of the Value- at- Risk (VaR and Expected Shortfalls (ES with respect to portfolio allocation in emerging markets with an index portfolio of a developed market. This study utilised different models for VaR and ES techniques using various scenario-based models such as Covariance Methods, Historical Simulation and the GARCH (1, 1 for the predictive ability of these models in both relatively stable market conditions and extreme market conditions. The results showed that Expected Shortfall has less risk tolerance than VaR based on the same scenario-based market risk measures

  14. Study on Market Stability and Price Limit of Chinese Stock Index Futures Market: An Agent-Based Modeling Perspective.

    Science.gov (United States)

    Xiong, Xiong; Nan, Ding; Yang, Yang; Yongjie, Zhang

    2015-01-01

    This paper explores a method of managing the risk of the stock index futures market and the cross-market through analyzing the effectiveness of price limits on the Chinese Stock Index 300 futures market. We adopt a cross-market artificial financial market (include the stock market and the stock index futures market) as a platform on which to simulate the operation of the CSI 300 futures market by changing the settings of price limits. After comparing the market stability under different price limits by appropriate liquidity and volatility indicators, we find that enhancing price limits or removing price limits both play a negative impact on market stability. In contrast, a positive impact exists on market stability if the existing price limit is maintained (increase of limit by10%, down by 10%) or it is broadened to a proper extent. Our study provides reasonable advice for a price limit setting and risk management for CSI 300 futures.

  15. Risk-based technical specifications program: Site interview results

    International Nuclear Information System (INIS)

    Andre, G.R.; Baker, A.J.; Johnson, R.L.

    1991-08-01

    The Electric Power Research Institute and Pacific Gas and Electric Company are sponsoring a program directed at improving Technical Specifications using risk-based methods. The major objectives of the program are to develop risk-based approaches to improve Technical Specifications and to develop an Interactive Risk Advisor (IRA) prototype. The IRA is envisioned as an interactive system that is available to plant personnel to assist in controlling plant operation. Use of an IRA is viewed as a method to improve plant availability while maintaining or improving plant safety. In support of the program, interviews were conducted at several PWR and BWR plant sites, to elicit opinions and information concerning risk-based approaches to Technical Specifications and IRA requirements. This report presents the results of these interviews, including the functional requirements of an IRA. 2 refs., 6 figs., 2 tabs

  16. Risk based regulation: a convenient concept for legislation and regulation in the field of technical risks?

    International Nuclear Information System (INIS)

    Seiler, J.H.

    1998-01-01

    Legislation and regulation concerning risk activities are traditionally based on deterministic safety measures. This may lead to inefficient results: sometimes the law requires safety measures which are - from an economic viewpoint - not justified because of their poor cost-effectiveness; sometimes it does not require safety measures although they would be very efficient. The risk based regulation approach wants to make the law more efficient and to get more safety at less costs. Legislation and regulation should be based on terms of risk rather than on deterministic rules. Risk should be expressed in quantitative terms and risk regulation should be based on the cost-effectiveness of safety measures. Thus a most efficient (in the sense of the economic analysis of the law) strategy for safety and environmental law could be established. The approach is economically reasonable and theoretically convincing. Its practical implementation however raises a lot of technical and legal questions. The project 'Risk Based Regulation' (1996-1999), sponsored by the Swiss National Fund for Scientific Research, intends to evaluate the practical feasibility of the approach from a technical and a legal view. It contains a general part which describes the risk based regulation approach and its legal and technical questions, case studies which try to practically implement the risk based regulation approach; the case studies are: storage and management of explosives in the army, storage and management of explosives for non-military purposes, safety at work, accident prevention in the non-professional field (mainly road accidents), fire protection, transportation of dangerous goods, waste disposal: traditional waste, waste disposal: radioactive waste, nuclear energy (reactor safety), a synthesis with recommendations for the future legislation and regulation in the field of technical risks. The paper presents the project and its preliminary results. (author)

  17. Reducing risks of Transfusion-transmitted infections in a resource-limited hospital-based blood bank: the case of the Yaoundé University Teaching Hospital, Cameroon

    Science.gov (United States)

    Tagny, C. T.; Ndoumba, A.; Laperche, S.; Murphy, E.; Mbanya, D.

    2016-01-01

    Background and Objectives Although interest in assessing risk of TTIs, very few trends in blood safety epidemiological data from resource-limited blood services are reported in the literature. This analysis aims at reporting trends in seroprevalences of TTIs in blood donations in the Yaoundé University Teaching Hospital (UTH) from 2011 to 2015 and to describe reasons for these changes. Materials and Methods All donations of 2015 were tested for HIV 1&2 antibodies and the P24 antigen, HBsAg, HCV antibody and the Treponema pallidum antibody. Screening for HIV uses a national algorithm based on the systematic use of two assays of different principles: a rapid determination testing assay and an EIA HIV 1 & 2 Ab-Ag. The tests used for HBsAg and HCVAb screening were all based on EIA techniques. Treponema pallidum antibody screening was based on Treponema Pallidum hemagglutination assay (TPHA) and rapid immunochromatographic test (RIT). Screening techniques and results from 2015 were compared to retrospective data from 2011, 2012, 2013 and 2014. Results In 2015, 13·4% (n = 214) of 1,596 blood donations were seropositive for at least one screened TTIs. The most frequent serological marker was HBsAg with 123 (7·7%) blood units contaminated. Nineteen (1·2%) and 18 (1·1%) blood units was positive for HIV and syphilis, respectively. There was a significant decrease in the total number of blood donations (P < 10−4) and HIV, HBsAg and syphilis seroprevalences and an increase in the proportion of voluntary non-remunerated blood donor (P < 0·05). HCVAb seroprevalence was 3·8% in 2015 and has not decreased significantly over the years (P = 0·09). Conclusion Significant progress is noted in reduction in seroprevalences of HIV, HBV, HCV and syphilis since the beginning of a regular registration of data in 1990. PMID:28484511

  18. 77 FR 39387 - Loan Policies and Operations; Lending and Leasing Limits and Risk Management; Effective Date

    Science.gov (United States)

    2012-07-03

    ... FARM CREDIT ADMINISTRATION 12 CFR Part 614 RIN 3052-AC60 Loan Policies and Operations; Lending and Leasing Limits and Risk Management; Effective Date AGENCY: Farm Credit Administration. ACTION: Notice of effective date. SUMMARY: The Farm Credit Administration (FCA or Agency), through the FCA Board (Board...

  19. Occupational dose equivalent limits

    International Nuclear Information System (INIS)

    Goldfinch, E.P.

    1980-01-01

    This paper considers methods of limiting individual radiation risks by recognizing the variation of risk with age at exposure, taking into account both somatic and genetic risks and proposes a simple formula for controlling individual cumulative exposure and hence risk. (Author)

  20. 76 FR 13902 - Fair Credit Reporting Risk-Based Pricing Regulations

    Science.gov (United States)

    2011-03-15

    ... TRADE COMMISSION 16 CFR Parts 640 and 698 RIN R411009 Fair Credit Reporting Risk-Based Pricing... respective risk-based pricing rules to require disclosure of credit scores and information relating to credit scores in risk-based pricing notices if a credit score of the consumer is used in setting the material...

  1. Urban flooding and health risk analysis by use of quantitative microbial risk assessment

    DEFF Research Database (Denmark)

    Andersen, Signe Tanja

    D thesis is to identify the limitations and possibilities for optimising microbial risk assessments of urban flooding through more evidence-based solutions, including quantitative microbial data and hydrodynamic water quality models. The focus falls especially on the problem of data needs and the causes......, but also when wading through a flooded area. The results in this thesis have brought microbial risk assessments one step closer to more uniform and repeatable risk analysis by using actual and relevant measured data and hydrodynamic water quality models to estimate the risk from flooding caused...... are expected to increase in the future. To ensure public health during extreme rainfall, solutions are needed, but limited knowledge on microbial water quality, and related health risks, makes it difficult to implement microbial risk analysis as a part of the basis for decision making. The main aim of this Ph...

  2. Alternative approaches to risk-based technical specifications

    International Nuclear Information System (INIS)

    Atefi, B.; Gallagher, D.W.; Liner, R.T.; Lofgren, E.V.

    1987-01-01

    Four alternative risk-based approaches to Technical Specifications are identified. These are: a Probabilistic Risk Assessment (PRA) oriented approach; a reliability goal-oriented approach; an approach based on configuration control; a data-oriented approach. Based on preliminary results, the PRA-oriented approach, which has been developed further than the other approaches, seems to offer a logical, quantitative basis for setting Allowed Outage Times (AOTs) and Surveillance Test Intervals (STIs) for some plant components and systems. The most attractive feature of this approach is that it directly links the AOTs and STIs with the risk associated with the operation of the plant. This would focus the plant operator's and the regulatory agency's attention on the most risk-significant components of the plant. A series of practical issues related to the level of detail and content of the plant PRAs, requirements for the review of these PRAs, and monitoring cf the plant's performance by the regulatory agency must be resolved before the approach could be implemented. Future efforts will examine the other three approaches and their practicality before firm conclusions are drawn regarding the viability of any of these approaches

  3. The clinical performance of an office-based risk scoring system for fatal cardiovascular diseases in North-East of Iran.

    Directory of Open Access Journals (Sweden)

    Sadaf G Sepanlou

    Full Text Available Cardiovascular diseases (CVD are becoming major causes of death in developing countries. Risk scoring systems for CVD are needed to prioritize allocation of limited resources. Most of these risk score algorithms have been based on a long array of risk factors including blood markers of lipids. However, risk scoring systems that solely use office-based data, not including laboratory markers, may be advantageous. In the current analysis, we validated the office-based Framingham risk scoring system in Iran.The study used data from the Golestan Cohort in North-East of Iran. The following risk factors were used in the development of the risk scoring method: sex, age, body mass index, systolic blood pressure, hypertension treatment, current smoking, and diabetes. Cardiovascular risk functions for prediction of 10-year risk of fatal CVDs were developed.A total of 46,674 participants free of CVD at baseline were included. Predictive value of estimated risks was examined. The resulting Area Under the ROC Curve (AUC was 0.774 (95% CI: 0.762-0.787 in all participants, 0.772 (95% CI: 0.753-0.791 in women, and 0.763 (95% CI: 0.747-0.779 in men. AUC was higher in urban areas (0.790, 95% CI: 0.766-0.815. The predicted and observed risks of fatal CVD were similar in women. However, in men, predicted probabilities were higher than observed.The AUC in the current study is comparable to results of previous studies while lipid profile was replaced by body mass index to develop an office-based scoring system. This scoring algorithm is capable of discriminating individuals at high risk versus low risk of fatal CVD.

  4. Study on institutionalization of risk-informed performance-based regulation

    Energy Technology Data Exchange (ETDEWEB)

    Kim, M. G.; Hong, S. Y.; Seo, M. R. [Korea Electric Power Research Institute, Taejon (Korea, Republic of)

    2003-02-15

    In this study, for the institutionalization of risk informed and performance based regulation in Korea, the latest technical movements of overseas countries are examined and reviewed. And the issues that was found when license change petition using risk information was submitted in Korean regulatory body are reviewed. Based on these review, the applicable areas to domestic situation will be found and proposed. This study can contribute to setting up the proper direction for the institutionalization of risk informed and performance based regulation.

  5. Finite element-based limit load of piping branch junctions under combined loadings

    International Nuclear Information System (INIS)

    Xuan Fuzhen; Li Peining

    2004-01-01

    The limit load is an important input parameter in engineering defect-assessment procedures and strength design. In the present work, a total of 100 different piping branch junction models for the limit load calculation were performed under combined internal pressure and moments in use of non-linear finite element (FE) method. Three different existing accumulation rules for limit load, i.e., linear equation, parabolic equation and quadratic equation were discussed on the basis of FE results. A novel limit load solution was developed based on detailed three-dimensional FE limit analyses which accommodated the geometrical parameter influence, together with analytical solutions based on equilibrium stress fields. Finally, six experimental results were provided to justify the presented equation. According to the FE limit analysis, limit load interaction of the piping tees under combined pressure and moments has a relationship with the geometrical parameters, especially with the diameter ratio d/D. The predicted limit loads from the presented formula are very close to the experimental data. The resulting limit load solution is given in a closed form, and thus can be easily used in practice

  6. Risk-based replacement strategies for redundant deteriorating reinforced concrete pipe networks

    International Nuclear Information System (INIS)

    Adey, B.; Bernard, O.; Gerard, B.

    2003-01-01

    This paper gives an example of how predictive models of the deterioration of reinforced concrete pipes and the consequences of failure can be used to develop risk-based replacement strategies for redundant reinforced concrete pipe networks. It also shows how an accurate deterioration prediction can lead to a reduction of agency costs, and illustrates the limitation of the incremental intervention step algorithm. The main conclusion is that the use of predictive models, such as those developed by Oxand S.A., in the determination of replacement strategies for redundant reinforced concrete pipe networks can lead to a significant reduction in overall costs for the owner of the structure. (author)

  7. Wind Power Fluctuation Smoothing Controller Based on Risk Assessment of Grid Frequency Deviation in an Isolated System

    DEFF Research Database (Denmark)

    Lin, Jin; Sun, Yuanzhang; Song, Yonghua

    2013-01-01

    a smoothing controller to suppress the power fluctuation from doubly-fed induction generator (DFIG)-based wind farm. This controller consists of threemain functionality components: risk assessmentmodel, wind turbine rotor speed optimizer, and rotor speed upper limiter. In order to avoid unnecessary energy...... curve with reduced output so that a trade-off between fluctuation smoothing and energy loss is achieved. Subsequently, the controller limits the maximum rotor speed to shift down the power curve of wind power plant based on the optimal wind turbine rotor speed. Therefore, the power fluctuation......Wind power fluctuation raises the security concern of grid frequency deviation, especially for an isolated power system. Thus, better control methodology needs to be developed to smooth the fluctuation without excessive spillage. Based on an actual industrial power system, this paper proposes...

  8. Blended Risk Approach in Applying PSA Models to Risk-Based Regulations

    International Nuclear Information System (INIS)

    Dimitrijevic, V. B.; Chapman, J. R.

    1996-01-01

    In this paper, the authors will discuss a modern approach in applying PSA models in risk-based regulation. The Blended Risk Approach is a combination of traditional and probabilistic processes. It is receiving increased attention in different industries in the U. S. and abroad. The use of the deterministic regulations and standards provides a proven and well understood basis on which to assess and communicate the impact of change to plant design and operation. Incorporation of traditional values into risk evaluation is working very well in the blended approach. This approach is very application specific. It includes multiple risk attributes, qualitative risk analysis, and basic deterministic principles. In blending deterministic and probabilistic principles, this approach ensures that the objectives of the traditional defense-in-depth concept are not compromised and the design basis of the plant is explicitly considered. (author)

  9. Using ensemble weather forecast in a risk based real time optimization of urban drainage systems

    DEFF Research Database (Denmark)

    Courdent, Vianney Augustin Thomas; Vezzaro, Luca; Mikkelsen, Peter Steen

    2015-01-01

    Global Real Time Control (RTC) of urban drainage system is increasingly seen as cost-effective solution in order to respond to increasing performance demand (e.g. reduction of Combined Sewer Overflow, protection of sensitive areas as bathing water etc.). The Dynamic Overflow Risk Assessment (DORA......) strategy was developed to operate Urban Drainage Systems (UDS) in order to minimize the expected overflow risk by considering the water volume presently stored in the drainage network, the expected runoff volume based on a 2-hours radar forecast model and an estimated uncertainty of the runoff forecast....... However, such temporal horizon (1-2 hours) is relatively short when used for the operation of large storage facilities, which may require a few days to be emptied. This limits the performance of the optimization and control in reducing combined sewer overflow and in preparing for possible flooding. Based...

  10. Risk-based management of invading plant disease.

    Science.gov (United States)

    Hyatt-Twynam, Samuel R; Parnell, Stephen; Stutt, Richard O J H; Gottwald, Tim R; Gilligan, Christopher A; Cunniffe, Nik J

    2017-05-01

    Effective control of plant disease remains a key challenge. Eradication attempts often involve removal of host plants within a certain radius of detection, targeting asymptomatic infection. Here we develop and test potentially more effective, epidemiologically motivated, control strategies, using a mathematical model previously fitted to the spread of citrus canker in Florida. We test risk-based control, which preferentially removes hosts expected to cause a high number of infections in the remaining host population. Removals then depend on past patterns of pathogen spread and host removal, which might be nontransparent to affected stakeholders. This motivates a variable radius strategy, which approximates risk-based control via removal radii that vary by location, but which are fixed in advance of any epidemic. Risk-based control outperforms variable radius control, which in turn outperforms constant radius removal. This result is robust to changes in disease spread parameters and initial patterns of susceptible host plants. However, efficiency degrades if epidemiological parameters are incorrectly characterised. Risk-based control including additional epidemiology can be used to improve disease management, but it requires good prior knowledge for optimal performance. This focuses attention on gaining maximal information from past epidemics, on understanding model transferability between locations and on adaptive management strategies that change over time. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

  11. Risk-based decisionmaking in the DOE: Challenges and status

    International Nuclear Information System (INIS)

    Henry, C.J.; Alchowiak, J.; Moses, M.

    1995-01-01

    The primary mission of the Environmental Management Program is to protect human health and the environment, the first goal of which must be, to address urgent risks and threats. Another is to provide for a safe workplace. Without credible risk assessments and good risk management practices, the central environmental goals cannot be met. Principles for risk analysis which include principles for risk assessment, management, communication, and priority setting were adopted. As recommended, Environmental Management is using risk-based decision making in its budget process and in the implementation of its program. The challenges presented in using a risk-based Decision making process are to integrate risk assessment methods and cultural and social values so as to produce meaningful priorities. The different laws and regulations governing the Department define risk differently in implementing activities to protect human health and the environment, therefore, assumptions and judgements in risk analysis vary. Currently, the Environmental Management Program is developing and improving a framework to incorporate risk into the budget process and to link the budget, compliance requirements and risk reduction/pollution prevention activities

  12. Risk-based decisionmaking in the DOE: Challenges and status

    Energy Technology Data Exchange (ETDEWEB)

    Henry, C.J.; Alchowiak, J.; Moses, M. [Dept. of Energy, Washington, DC (United States)] [and others

    1995-12-31

    The primary mission of the Environmental Management Program is to protect human health and the environment, the first goal of which must be, to address urgent risks and threats. Another is to provide for a safe workplace. Without credible risk assessments and good risk management practices, the central environmental goals cannot be met. Principles for risk analysis which include principles for risk assessment, management, communication, and priority setting were adopted. As recommended, Environmental Management is using risk-based decision making in its budget process and in the implementation of its program. The challenges presented in using a risk-based Decision making process are to integrate risk assessment methods and cultural and social values so as to produce meaningful priorities. The different laws and regulations governing the Department define risk differently in implementing activities to protect human health and the environment, therefore, assumptions and judgements in risk analysis vary. Currently, the Environmental Management Program is developing and improving a framework to incorporate risk into the budget process and to link the budget, compliance requirements and risk reduction/pollution prevention activities.

  13. Risk assessment and model for community-based construction ...

    African Journals Online (AJOL)

    It, therefore, becomes necessary to systematically manage uncertainty in community-based construction in order to increase the likelihood of meeting project objectives using necessary risk management strategies. Risk management, which is an iterative process due to the dynamic nature of many risks, follows three main ...

  14. Impact of selected risk factors on expected lifetime without long-standing, limiting illness in Denmark

    DEFF Research Database (Denmark)

    Brønnum-Hansen, Henrik; Juel, Knud; Davidsen, Michael

    2007-01-01

    long-standing, limiting illness was 8-10 years shorter among sedentary than physically active people. Obesity shortened lifetime without illness by 5 years for men and ten years for women. CONCLUSION: The results of this study could be used in health policy-making, as the potential gains in public......OBJECTIVE: To estimate the impacts of tobacco smoking, high alcohol consumption, physical inactivity and overweight on expected lifetime with and without long-standing, limiting illness. METHODS: Life tables for each level of exposure to the risk factors were constructed, mainly on the basis......-olds was 9-10 years shorter for heavy smokers than for those who never smoke, and all the lifetime lost would have been without long-standing, limiting illness. Similarly, all 5 years of expected lifetime lost by men with high alcohol consumption would have been without illness. The expected lifetime without...

  15. Population-based absolute risk estimation with survey data

    Science.gov (United States)

    Kovalchik, Stephanie A.; Pfeiffer, Ruth M.

    2013-01-01

    Absolute risk is the probability that a cause-specific event occurs in a given time interval in the presence of competing events. We present methods to estimate population-based absolute risk from a complex survey cohort that can accommodate multiple exposure-specific competing risks. The hazard function for each event type consists of an individualized relative risk multiplied by a baseline hazard function, which is modeled nonparametrically or parametrically with a piecewise exponential model. An influence method is used to derive a Taylor-linearized variance estimate for the absolute risk estimates. We introduce novel measures of the cause-specific influences that can guide modeling choices for the competing event components of the model. To illustrate our methodology, we build and validate cause-specific absolute risk models for cardiovascular and cancer deaths using data from the National Health and Nutrition Examination Survey. Our applications demonstrate the usefulness of survey-based risk prediction models for predicting health outcomes and quantifying the potential impact of disease prevention programs at the population level. PMID:23686614

  16. Big data based fraud risk management at Alibaba

    Directory of Open Access Journals (Sweden)

    Jidong Chen

    2015-12-01

    Full Text Available With development of mobile internet and finance, fraud risk comes in all shapes and sizes. This paper is to introduce the Fraud Risk Management at Alibaba under big data. Alibaba has built a fraud risk monitoring and management system based on real-time big data processing and intelligent risk models. It captures fraud signals directly from huge amount data of user behaviors and network, analyzes them in real-time using machine learning, and accurately predicts the bad users and transactions. To extend the fraud risk prevention ability to external customers, Alibaba also built up a big data based fraud prevention product called AntBuckler. AntBuckler aims to identify and prevent all flavors of malicious behaviors with flexibility and intelligence for online merchants and banks. By combining large amount data of Alibaba and customers', AntBuckler uses the RAIN score engine to quantify risk levels of users or transactions for fraud prevention. It also has a user-friendly visualization UI with risk scores, top reasons and fraud connections.

  17. Coronary risk assessment by point-based vs. equation-based Framingham models: significant implications for clinical care.

    Science.gov (United States)

    Gordon, William J; Polansky, Jesse M; Boscardin, W John; Fung, Kathy Z; Steinman, Michael A

    2010-11-01

    US cholesterol guidelines use original and simplified versions of the Framingham model to estimate future coronary risk and thereby classify patients into risk groups with different treatment strategies. We sought to compare risk estimates and risk group classification generated by the original, complex Framingham model and the simplified, point-based version. We assessed 2,543 subjects age 20-79 from the 2001-2006 National Health and Nutrition Examination Surveys (NHANES) for whom Adult Treatment Panel III (ATP-III) guidelines recommend formal risk stratification. For each subject, we calculated the 10-year risk of major coronary events using the original and point-based Framingham models, and then compared differences in these risk estimates and whether these differences would place subjects into different ATP-III risk groups (20% risk). Using standard procedures, all analyses were adjusted for survey weights, clustering, and stratification to make our results nationally representative. Among 39 million eligible adults, the original Framingham model categorized 71% of subjects as having "moderate" risk (20%) risk. Estimates of coronary risk by the original and point-based models often differed substantially. The point-based system classified 15% of adults (5.7 million) into different risk groups than the original model, with 10% (3.9 million) misclassified into higher risk groups and 5% (1.8 million) into lower risk groups, for a net impact of classifying 2.1 million adults into higher risk groups. These risk group misclassifications would impact guideline-recommended drug treatment strategies for 25-46% of affected subjects. Patterns of misclassifications varied significantly by gender, age, and underlying CHD risk. Compared to the original Framingham model, the point-based version misclassifies millions of Americans into risk groups for which guidelines recommend different treatment strategies.

  18. Risk-based audit selection of dairy farms

    NARCIS (Netherlands)

    Asseldonk, van M.A.P.M.; Velthuis, A.G.J.

    2014-01-01

    Dairy farms are audited in the Netherlands on numerous process standards. Each farm is audited once every 2 years. Increasing demands for cost-effectiveness in farm audits can be met by introducing risk-based principles. This implies targeting subpopulations with a higher risk of poor process

  19. Physically based probability criterion for exceeding radionuclide concentration limits in heterogeneous bedrock

    International Nuclear Information System (INIS)

    Worman, A.; Xu, S.; Dverstorp, B.

    2004-01-01

    A significant problem in a risk analysis of the repository for high-level nuclear waste is to estimate the barrier effect of the geosphere. The significant spatial variability of the rock properties implies that migrating RNs encounter a distribution of bedrock properties and mass-transfer mechanisms in different proportions along the transport paths. For practical reasons, we will never be able to know exactly this distribution of properties by performing a reasonable amount of measurements in a site investigation. On the contrary, recent experimental studies reveal that crystalline bedrock can possess a marked heterogeneity of various physical and geochemical properties that potentially may have a certain impact on the transport of RNs in fractured bedrock. Also current field investigation techniques provide only fragmentary information of the properties of the geosphere. This is a basic motivation for treating flows of water and solute elements in groundwaters by means of stochastic continuum models. The stochastic analysis is based on the idea that we know only certain point values of the property fields and use this information to estimate intermediate values. The probabilistic properties of the stochastic analysis are suitable input variables for risk analyses of the relevant sequence of extreme events for which empirical observations are rare or non-existing. The purpose of this paper is to outline the implications of the stochastic approach for estimating probabilities that certain concentration limits are exceeded at discharge points from. the bedrock in case of a leakage from the waste repository. The analysis is restricted to the water flow and solute transport in the bedrock alone without consideration of the full sequence of events in a full risk analysis and the Bayesian statistics involved in such conditioned (and cross-correlated) event series. The focus is on the implication for the risk analysis of the auto-covariance structure in bedrock

  20. Limitations and problems in deriving risk estimates for low-level radiation exposure

    International Nuclear Information System (INIS)

    Cohen, B.L.

    1981-01-01

    Some of the problems in determining the cancer risk of low-level radiation from studies of exposed groups are reviewed and applied to the study of Hanford workers by Mancuso, Stewart, and Kneale. Problems considered are statistical limitations, variation of cancer rates with geography and race, the ''healthy worker effect,'' calendar year and age variation of cancer mortality, choosing from long lists, use of proportional mortality rates, cigarette smoking-cancer correlations, use of averages to represent data distributions, ignoring other data, and correlations between radiation exposure and other factors that may cause cancer. The current status of studies of the Hanford workers is reviewed

  1. LIFETIME LUNG CANCER RISKS ASSOCIATED WITH INDOOR RADON EXPOSURE BASED ON VARIOUS RADON RISK MODELS FOR CANADIAN POPULATION.

    Science.gov (United States)

    Chen, Jing

    2017-04-01

    This study calculates and compares the lifetime lung cancer risks associated with indoor radon exposure based on well-known risk models in the literature; two risk models are from joint studies among miners and the other three models were developed from pooling studies on residential radon exposure from China, Europe and North America respectively. The aim of this article is to make clear that the various models are mathematical descriptions of epidemiologically observed real risks in different environmental settings. The risk from exposure to indoor radon is real and it is normal that variations could exist among different risk models even when they were applied to the same dataset. The results show that lifetime risk estimates vary significantly between the various risk models considered here: the model based on the European residential data provides the lowest risk estimates, while models based on the European miners and Chinese residential pooling with complete dosimetry give the highest values. The lifetime risk estimates based on the EPA/BEIR-VI model lie within this range and agree reasonably well with the averages of risk estimates from the five risk models considered in this study. © Crown copyright 2016.

  2. Nitrate in drinking water and colorectal cancer risk: A nationwide population-based cohort study.

    Science.gov (United States)

    Schullehner, Jörg; Hansen, Birgitte; Thygesen, Malene; Pedersen, Carsten B; Sigsgaard, Torben

    2018-07-01

    Nitrate in drinking water may increase risk of colorectal cancer due to endogenous transformation into carcinogenic N-nitroso compounds. Epidemiological studies are few and often challenged by their limited ability of estimating long-term exposure on a detailed individual level. We exploited population-based health register data, linked in time and space with longitudinal drinking water quality data, on an individual level to study the association between long-term drinking water nitrate exposure and colorectal cancer (CRC) risk. Individual nitrate exposure was calculated for 2.7 million adults based on drinking water quality analyses at public waterworks and private wells between 1978 and 2011. For the main analyses, 1.7 million individuals with highest exposure assessment quality were included. Follow-up started at age 35. We identified 5,944 incident CRC cases during 23 million person-years at risk. We used Cox proportional hazards models to estimate hazard ratios (HRs) of nitrate exposure on the risk of CRC, colon and rectal cancer. Persons exposed to the highest level of drinking water nitrate had an HR of 1.16 (95% CI: 1.08-1.25) for CRC compared with persons exposed to the lowest level. We found statistically significant increased risks at drinking water levels above 3.87 mg/L, well below the current drinking water standard of 50 mg/L. Our results add to the existing evidence suggesting increased CRC risk at drinking water nitrate concentrations below the current drinking water standard. A discussion on the adequacy of the drinking water standard in regards to chronic effects is warranted. © 2018 UICC.

  3. PENGARUH PELAKSANAAN RISK BASED INTERNAL AUDITING TERHADAP PENCEGAHAN FRAUD

    Directory of Open Access Journals (Sweden)

    Rozmita Dewi Yuniarti Rozali

    2015-12-01

    Full Text Available This study aims to determine the effect of implementation of risk based internal auditing on fraud prevention on internal audit Inspection Office Bank BRI Bandung Region. The sample used by 18 internal auditors in Inspection Office of Bank BRI Bandung Region saturated sampling method. Based on calculation of simple regression analysis obtained result that every increase of implementation of risk based internal auditing (X will lead to increase fraud prevention (Y. It shows that there is a positive influence between the implementation of risk based internal auditing on fraud prevention on the internal audit of Inspection Office of Bank BRI Bandung Region.

  4. Risk-based classification system of nanomaterials

    International Nuclear Information System (INIS)

    Tervonen, Tommi; Linkov, Igor; Figueira, Jose Rui; Steevens, Jeffery; Chappell, Mark; Merad, Myriam

    2009-01-01

    Various stakeholders are increasingly interested in the potential toxicity and other risks associated with nanomaterials throughout the different stages of a product's life cycle (e.g., development, production, use, disposal). Risk assessment methods and tools developed and applied to chemical and biological materials may not be readily adaptable for nanomaterials because of the current uncertainty in identifying the relevant physico-chemical and biological properties that adequately describe the materials. Such uncertainty is further driven by the substantial variations in the properties of the original material due to variable manufacturing processes employed in nanomaterial production. To guide scientists and engineers in nanomaterial research and application as well as to promote the safe handling and use of these materials, we propose a decision support system for classifying nanomaterials into different risk categories. The classification system is based on a set of performance metrics that measure both the toxicity and physico-chemical characteristics of the original materials, as well as the expected environmental impacts through the product life cycle. Stochastic multicriteria acceptability analysis (SMAA-TRI), a formal decision analysis method, was used as the foundation for this task. This method allowed us to cluster various nanomaterials in different ecological risk categories based on our current knowledge of nanomaterial physico-chemical characteristics, variation in produced material, and best professional judgments. SMAA-TRI uses Monte Carlo simulations to explore all feasible values for weights, criteria measurements, and other model parameters to assess the robustness of nanomaterial grouping for risk management purposes.

  5. A carbon risk prediction model for Chinese heavy-polluting industrial enterprises based on support vector machine

    International Nuclear Information System (INIS)

    Zhou, Zhifang; Xiao, Tian; Chen, Xiaohong; Wang, Chang

    2016-01-01

    Chinese heavy-polluting industrial enterprises, especially petrochemical or chemical industry, labeled low carbon efficiency and high emission load, are facing the tremendous pressure of emission reduction under the background of global shortage of energy supply and constrain of carbon emission. However, due to the limited amount of theoretic and practical research in this field, problems like lacking prediction indicators or models, and the quantified standard of carbon risk remain unsolved. In this paper, the connotation of carbon risk and an assessment index system for Chinese heavy-polluting industrial enterprises (eg. coal enterprise, petrochemical enterprises, chemical enterprises et al.) based on support vector machine are presented. By using several heavy-polluting industrial enterprises’ related data, SVM model is trained to predict the carbon risk level of a specific enterprise, which allows the enterprise to identify and manage its carbon risks. The result shows that this method can predict enterprise’s carbon risk level in an efficient, accurate way with high practical application and generalization value.

  6. Risk-based regulation: A regulatory perspective

    International Nuclear Information System (INIS)

    Scarborough, J.C.

    1993-01-01

    In the early development of regulations for nuclear power plants, risk was implicitly considered through qualitative assessments and engineering reliability principles and practices. Examples included worst case analysis, defense in depth, and the single failure criterion. However, the contributions of various systems, structures, components and operator actions to plant safety were not explicitly assessed since a methodology for this purpose had not been developed. As a consequence of the TMI accident, the use of more quantitative risk methodology and information in regulation such as probabilistic risk analysis (PRA) increased. The use of both qualitative and quantitative consideration of risk in regulation has been a set of regulations and regulatory guides and practices that ensure adequate protection of public health and safety. Presently, the development of PRA techniques has developed to the point that safety goals, expressed in terms of risk, have been established to help guide further regulatory decision making. This paper presents the personal opinions of the author as regards the use of risk today in nuclear power plant regulation, areas of further information needs, and necessary plans for moving toward a more systematic use of risk-based information in regulatory initiatives in the future

  7. Train integrity detection risk analysis based on PRISM

    Science.gov (United States)

    Wen, Yuan

    2018-04-01

    GNSS based Train Integrity Monitoring System (TIMS) is an effective and low-cost detection scheme for train integrity detection. However, as an external auxiliary system of CTCS, GNSS may be influenced by external environments, such as uncertainty of wireless communication channels, which may lead to the failure of communication and positioning. In order to guarantee the reliability and safety of train operation, a risk analysis method of train integrity detection based on PRISM is proposed in this article. First, we analyze the risk factors (in GNSS communication process and the on-board communication process) and model them. Then, we evaluate the performance of the model in PRISM based on the field data. Finally, we discuss how these risk factors influence the train integrity detection process.

  8. Risk-based optimization of land reclamation

    International Nuclear Information System (INIS)

    Lendering, K.T.; Jonkman, S.N.; Gelder, P.H.A.J.M. van; Peters, D.J.

    2015-01-01

    Large-scale land reclamations are generally constructed by means of a landfill well above mean sea level. This can be costly in areas where good quality fill material is scarce. An alternative to save materials and costs is a ‘polder terminal’. The quay wall acts as a flood defense and the terminal level is well below the level of the quay wall. Compared with a conventional terminal, the costs are lower, but an additional flood risk is introduced. In this paper, a risk-based optimization is developed for a conventional and a polder terminal. It considers the investment and residual flood risk. The method takes into account both the quay wall and terminal level, which determine the probability and damage of flooding. The optimal quay wall level is found by solving a Lambert function numerically. The terminal level is bounded by engineering boundary conditions, i.e. piping and uplift of the cover layer of the terminal yard. It is found that, for a representative case study, the saving of reclamation costs for a polder terminal is larger than the increase of flood risk. The model is applicable to other cases of land reclamation and to similar optimization problems in flood risk management. - Highlights: • A polder terminal can be an attractive alternative for a conventional terminal. • A polder terminal is feasible at locations with high reclamation cost. • A risk-based approach is required to determine the optimal protection levels. • The depth of the polder terminal yard is bounded by uplifting of the cover layer. • This paper can support decisions regarding alternatives for port expansions.

  9. Contrasting the Effect of Risk- and Non Risk-Based Capital Structure on Insurers’ Performance in Nigeria

    Directory of Open Access Journals (Sweden)

    Sunday S. Akpan

    2017-11-01

    Full Text Available Literature on capital-based regulation and performance of insurers in emerging market is not only limited; it is incomplete, particularly on a comparative basis. This has continuously attracts researchers’ interest and concerns for practitioners and policy makers. This paper therefore examines the effect of capital structure on performance of insurers comparatively before and after the implementation of risk-based capital (RBC policy in Nigeria to determine which policy regime enables insurers to perform better. Descriptive statistics are employed to describe the characteristics of the data while the hypotheses are tested using two-stage estimation procedure of fixed and random effect models. Results reveal that insurance capital structure (measured by technical provision ratio has a significant positive effect on insurance performance (measured by earnings per share and return on asset during non-RBC regime when compared to RBC regime. Based on these findings, it is concluded that insurers in Nigeria performed better under non-RBC than RBC era. This finding provides important insight to managers, regulators and investors by fostering more understanding of how to manipulate and regulate insurance capital for performance optimization under RBC scenarios.

  10. Risk Based Milk Pricing Model at Dairy Farmers Level

    Directory of Open Access Journals (Sweden)

    W. Septiani

    2017-12-01

    Full Text Available The milk price from a cooperative institution to farmer does not fully cover the production cost. Though, dairy farmers encounter various risks and uncertainties in conducting their business. The highest risk in milk supply lies in the activities at the farm. This study was designed to formulate a model for calculating milk price at farmer’s level based on risk. Risks that occur on farms include the risk of cow breeding, sanitation, health care, cattle feed management, milking and milk sales. This research used the location of the farm in West Java region. There were five main stages in the preparation of this model, (1 identification and analysis of influential factors, (2 development of a conceptual model, (3 structural analysis and the amount of production costs, (4 model calculation of production cost with risk factors, and (5 risk based milk pricing model. This research built a relationship between risks on smallholder dairy farms with the production costs to be incurred by the farmers. It was also obtained the formulation of risk adjustment factor calculation for the variable costs of production in dairy cattle farm. The difference in production costs with risk and the total production cost without risk was about 8% to 10%. It could be concluded that the basic price of milk proposed based on the research was around IDR 4,250-IDR 4,350/L for 3 to 4 cows ownership. Increasing farmer income was expected to be obtained by entering the value of this risk in the calculation of production costs. 

  11. Risk based maintenance to increase safety and decrease costs

    International Nuclear Information System (INIS)

    Phillips, J.H.

    2000-01-01

    Risk-Based techniques have been developed for commercial nuclear power plants for the last eight years by a team working through the ASME Center for Research and Technology Development (CRTD). System boundaries and success criteria is defined using the Probabilistic Risk Analysis or Probabilistic Safety Analysis developed to meet the Individual Plant Evaluation. Final ranking of components is by a plant expert panel similar to the one developed for the Maintenance Rule. Components are identified as being high risk-significant or low risk-significant. Maintenance and resources are focused on those components that have the highest risk-significance. The techniques have been developed and applied at a number of plants. Results from the first risk-based inspection pilot plant indicates safety due to pipe failure can be doubled while the inspection reduced to about 80% when compared with current inspection programs. Pilot studies on risk-based testing indicate that about 60% of pumps and 25 to 30% of valves in plants are high safety-significant The reduction in inspection and testing reduces the person-rem exposure and resulting in further increases in safety. These techniques have been documented in publications by the ASME CRTD which are referenced. (author)

  12. WTS - Risk Based Resource Targeting (RBRT) -

    Data.gov (United States)

    Department of Transportation — The Risk Based Resource Targeting (RBRT) application supports a new SMS-structured process designed to focus on safety oversight of systems and processes rather than...

  13. RiskREP : risk-based security requirements elicitation and prioritization

    NARCIS (Netherlands)

    Herrmann, A.; Morali, A.; Etalle, S.; Wieringa, R.J.

    2011-01-01

    Companies are under pressure to be in control of their assets but at the same time they must operate as efficiently as possible. This means that they aim to implement "good-enough security" but need to be able to justify their security investment plans. In this paper, we present a Risk-Based

  14. RiskREP: Risk-Based Security Requirements Elicitation and Prioritization

    NARCIS (Netherlands)

    Herrmann, Andrea; Morali, A.; Etalle, Sandro; Wieringa, Roelf J.; Niedrite, Laila; Strazdina, Renate; Wangler, Benkt

    2011-01-01

    Companies are under pressure to be in control of their assets but at the same time they must operate as efficiently as possible. This means that they aim to implement “good-enough security‿ but need to be able to justify their security investment plans. In this paper, we present a Risk-Based

  15. Risk evaluation in Dutch land-use planning

    NARCIS (Netherlands)

    Xanten, van N.H.W.; Pietersen, C.M.; Pasman, H.J.; Torn, van der P.; Vrijling, H.K.; Wal, van der A.J.; Kerstens, J.G.M.

    2014-01-01

    In Dutch external safety policy, the acceptance of risk for the population in areas surrounding hazardous substances establishments is based on a limit value for individual risk (IR). Additionally, changes to societal risk (SR) must be justified. A specific software program (SAFETI-NL) with the

  16. The Community – Based Flood Disaster Risk Reduction (CBDRR in Beringin Watershed in Semarang City

    Directory of Open Access Journals (Sweden)

    Tiara Sartika Worowirasmi

    2015-08-01

    Full Text Available Population growth in Semarang city is certainly increasing land demand for settlement. Limited land and weak regulation enforcement of land control trigger the land use change including the watershed area. Semarang City Spatial Plan 2011-2031 has determined Beringin as a buffer area with limited physical development allocation but the citizens utilized the watershed area for settlement. Settlement developments in the area reduce the watershed ability to catch water and river capacity due to increased sedimentation. These two reasons are the main cause of the flash flood disaster (regularly in rainy season in seven villages of Beringin watershed. The condition is exacerbated by the tidal flood occurred in two village lies in coastal. In 2012, Semarang City government developed Flood Forecasting and Warning System as one of Climate Change Adaptation Measures known as Flood Early Warning System (FEWS. One of important output of FEWS is community-based disaster risk reduction. Community participation process in the FEWS has made it possible for the community to identify disaster risk characteristics, to propose solution for reducing flood risk which is suitable to the local wisdom, to increase the community capacity and to organize one of themselves in a disaster preparedness group which run quite independently.

  17. Reliability Evaluation of Bridges Based on Nonprobabilistic Response Surface Limit Method

    OpenAIRE

    Chen, Xuyong; Chen, Qian; Bian, Xiaoya; Fan, Jianping

    2017-01-01

    Due to many uncertainties in nonprobabilistic reliability assessment of bridges, the limit state function is generally unknown. The traditional nonprobabilistic response surface method is a lengthy and oscillating iteration process and leads to difficultly solving the nonprobabilistic reliability index. This article proposes a nonprobabilistic response surface limit method based on the interval model. The intention of this method is to solve the upper and lower limits of the nonprobabilistic ...

  18. Clinical risk stratification optimizes value of biomarkers to predict new-onset heart failure in a community-based cohort.

    Science.gov (United States)

    Brouwers, Frank P; van Gilst, Wiek H; Damman, Kevin; van den Berg, Maarten P; Gansevoort, Ron T; Bakker, Stephan J L; Hillege, Hans L; van Veldhuisen, Dirk J; van der Harst, Pim; de Boer, Rudolf A

    2014-09-01

    We aim to identify and quantify the value of biomarkers for incident new-onset heart failure (HF) in a community-based cohort and subgroups based on cardiovascular risk and evaluate the prognostic value of 13 biomarkers for HF with reduced and preserved ejection fraction. Thirteen biomarkers reflecting diverse pathophysiologic domains were examined in 8569 HF-free participants in Prevention of Vascular and Renal Endstage Disease (mean age, 49 years; 50% men). Subjects were categorized in 2 risk groups based on cardiovascular history. Incremental value per biomarker was assessed using Harrell C-indices. One hundred sixty-eight subjects (2.4%) were diagnosed with new-onset HF in the low-risk group (n=6915; Framingham Risk Score, 5.9%) and 206 (12.2%) subjects in the high-risk group (n=1654; Framingham Risk Score, 18.6%). The association of natriuretic peptides, adrenomedullin, endothelin, and galectin-3 with new-onset HF was stronger in the high-risk group (all Prisk for new-onset HF between both risk groups. The best model for new-onset HF included the combination of N-terminal pro-B-type natriuretic peptide, troponin-T, and urinary albumin excretion, increasing model accuracy to 0.81 (9.5%, Prisk group. Except for a modest effect of cystatin-C, no biomarker was associated with increased risk for HF with preserved ejection fraction. Risk stratification increases the incremental value per biomarker to predict new-onset HF, especially HF with reduced ejection fraction. We suggest that routine biomarker testing should be limited to the use of natriuretic peptides and troponin-T in patients with increased cardiovascular risk. © 2014 American Heart Association, Inc.

  19. MgB2-based superconductors for fault current limiters

    Science.gov (United States)

    Sokolovsky, V.; Prikhna, T.; Meerovich, V.; Eisterer, M.; Goldacker, W.; Kozyrev, A.; Weber, H. W.; Shapovalov, A.; Sverdun, V.; Moshchil, V.

    2017-02-01

    A promising solution of the fault current problem in power systems is the application of fast-operating nonlinear superconducting fault current limiters (SFCLs) with the capability of rapidly increasing their impedance, and thus limiting high fault currents. We report the results of experiments with models of inductive (transformer type) SFCLs based on the ring-shaped bulk MgB2 prepared under high quasihydrostatic pressure (2 GPa) and by hot pressing technique (30 MPa). It was shown that the SFCLs meet the main requirements to fault current limiters: they possess low impedance in the nominal regime of the protected circuit and can fast increase their impedance limiting both the transient and the steady-state fault currents. The study of quenching currents of MgB2 rings (SFCL activation current) and AC losses in the rings shows that the quenching current density and critical current density determined from AC losses can be 10-20 times less than the critical current determined from the magnetization experiments.

  20. Risk-based configuration control system: Analysis and approaches

    International Nuclear Information System (INIS)

    Samanta, P.K.; Kim, I.S.; Lofgren, E.V.; Vesely, W.E.

    1990-01-01

    This paper presents an analysis of risks associated with component outage configurations during power operation of a nuclear power plant and discusses approaches and strategies for developing a risk-based configuration control system. A configuration, as used here, is a set of component states. The objective of risk-based configuration control is to detect and control plant configurations using a risk-perspective. The configuration contributions to core-melt frequency and core-melt probability are studied for two plants. Large core-melt frequency can be caused by configurations and there are a number of such configurations that are not currently controlled by technical specifications. However, the expected frequency of occurrence of the impacting configurations is small and the actual core-melt probability contributions are also generally small. Effective strategies and criteria for controlling configuration risks are presented. Such control strategies take into consideration the risks associated with configurations, the nature and characteristics of the configuration risks, and also the practical considerations such as adequate repair times and/or options to transfer to low risk configurations. Alternative types of criteria are discussed that are not overly restrictive to result in unnecessary plant shutdown, but rather motivates effective test and maintenance practices that control risk-significant configurations to allow continued operation with an adequate margin to meet challenges to safety

  1. Risk-based configuration control system: Analysis and approaches

    International Nuclear Information System (INIS)

    Samanta, P.K.; Vesely, W.E.; Kim, I.S.; Lofgren, E.V.

    1989-01-01

    This paper presents an analysis of risks associated with component outage configurations during power operation of a nuclear power plant and discusses approaches and strategies for developing a risk-based configuration control system. A configuration, as used here, is a set of component states. The objective of risk-based configuration control is to detect and control plant configurations using a risk-perspective. The configuration contributions to core-melt frequency and core-melt probability are studied for two plants. Large core-melt frequency can be caused by configurations and there are a number of such configurations that are not currently controlled by technical specifications. However, the expected frequency of occurrence of the impacting configurations is small and the actual core-melt probability contributions are also generally small. Effective strategies and criteria for controlling configuration risks are presented. Such control strategies take into consideration the risks associated with configurations, the nature and characteristics of the configuration risks, and also the practical considerations such as adequate repair times and/or options to transfer to low risk configurations. Alternative types of criteria are discussed that are not overly restrictive to result in unnecessary plant shutdown, but rather motivates effective tests and maintenance practices that control; risk-significant configurations to allow continued operation with an adequate margin to meet challenges to safety. 3 refs., 7 figs., 2 tabs

  2. Review of NASA approach to space radiation risk assessments for Mars exploration.

    Science.gov (United States)

    Cucinotta, Francis A

    2015-02-01

    Long duration space missions present unique radiation protection challenges due to the complexity of the space radiation environment, which includes high charge and energy particles and other highly ionizing radiation such as neutrons. Based on a recommendation by the National Council on Radiation Protection and Measurements, a 3% lifetime risk of exposure-induced death for cancer has been used as a basis for risk limitation by the National Aeronautics and Space Administration (NASA) for low-Earth orbit missions. NASA has developed a risk-based approach to radiation exposure limits that accounts for individual factors (age, gender, and smoking history) and assesses the uncertainties in risk estimates. New radiation quality factors with associated probability distribution functions to represent the quality factor's uncertainty have been developed based on track structure models and recent radiobiology data for high charge and energy particles. The current radiation dose limits are reviewed for spaceflight and the various qualitative and quantitative uncertainties that impact the risk of exposure-induced death estimates using the NASA Space Cancer Risk (NSCR) model. NSCR estimates of the number of "safe days" in deep space to be within exposure limits and risk estimates for a Mars exploration mission are described.

  3. Risk analysis of heat recovery steam generator with semi quantitative risk based inspection API 581

    Science.gov (United States)

    Prayogo, Galang Sandy; Haryadi, Gunawan Dwi; Ismail, Rifky; Kim, Seon Jin

    2016-04-01

    Corrosion is a major problem that most often occurs in the power plant. Heat recovery steam generator (HRSG) is an equipment that has a high risk to the power plant. The impact of corrosion damage causing HRSG power plant stops operating. Furthermore, it could be threaten the safety of employees. The Risk Based Inspection (RBI) guidelines by the American Petroleum Institute (API) 58 has been used to risk analysis in the HRSG 1. By using this methodology, the risk that caused by unexpected failure as a function of the probability and consequence of failure can be estimated. This paper presented a case study relating to the risk analysis in the HRSG, starting with a summary of the basic principles and procedures of risk assessment and applying corrosion RBI for process industries. The risk level of each HRSG equipment were analyzed: HP superheater has a medium high risk (4C), HP evaporator has a medium-high risk (4C), and the HP economizer has a medium risk (3C). The results of the risk assessment using semi-quantitative method of standard API 581 based on the existing equipment at medium risk. In the fact, there is no critical problem in the equipment components. Damage mechanisms were prominent throughout the equipment is thinning mechanism. The evaluation of the risk approach was done with the aim of reducing risk by optimizing the risk assessment activities.

  4. Risk analysis of heat recovery steam generator with semi quantitative risk based inspection API 581

    International Nuclear Information System (INIS)

    Prayogo, Galang Sandy; Haryadi, Gunawan Dwi; Ismail, Rifky; Kim, Seon Jin

    2016-01-01

    Corrosion is a major problem that most often occurs in the power plant. Heat recovery steam generator (HRSG) is an equipment that has a high risk to the power plant. The impact of corrosion damage causing HRSG power plant stops operating. Furthermore, it could be threaten the safety of employees. The Risk Based Inspection (RBI) guidelines by the American Petroleum Institute (API) 58 has been used to risk analysis in the HRSG 1. By using this methodology, the risk that caused by unexpected failure as a function of the probability and consequence of failure can be estimated. This paper presented a case study relating to the risk analysis in the HRSG, starting with a summary of the basic principles and procedures of risk assessment and applying corrosion RBI for process industries. The risk level of each HRSG equipment were analyzed: HP superheater has a medium high risk (4C), HP evaporator has a medium-high risk (4C), and the HP economizer has a medium risk (3C). The results of the risk assessment using semi-quantitative method of standard API 581 based on the existing equipment at medium risk. In the fact, there is no critical problem in the equipment components. Damage mechanisms were prominent throughout the equipment is thinning mechanism. The evaluation of the risk approach was done with the aim of reducing risk by optimizing the risk assessment activities.

  5. Risk analysis of heat recovery steam generator with semi quantitative risk based inspection API 581

    Energy Technology Data Exchange (ETDEWEB)

    Prayogo, Galang Sandy, E-mail: gasandylang@live.com; Haryadi, Gunawan Dwi; Ismail, Rifky [Department of Mechanical Engineering, Diponegoro University, Semarang (Indonesia); Kim, Seon Jin [Department of Mechanical & Automotive Engineering of Pukyong National University (Korea, Republic of)

    2016-04-19

    Corrosion is a major problem that most often occurs in the power plant. Heat recovery steam generator (HRSG) is an equipment that has a high risk to the power plant. The impact of corrosion damage causing HRSG power plant stops operating. Furthermore, it could be threaten the safety of employees. The Risk Based Inspection (RBI) guidelines by the American Petroleum Institute (API) 58 has been used to risk analysis in the HRSG 1. By using this methodology, the risk that caused by unexpected failure as a function of the probability and consequence of failure can be estimated. This paper presented a case study relating to the risk analysis in the HRSG, starting with a summary of the basic principles and procedures of risk assessment and applying corrosion RBI for process industries. The risk level of each HRSG equipment were analyzed: HP superheater has a medium high risk (4C), HP evaporator has a medium-high risk (4C), and the HP economizer has a medium risk (3C). The results of the risk assessment using semi-quantitative method of standard API 581 based on the existing equipment at medium risk. In the fact, there is no critical problem in the equipment components. Damage mechanisms were prominent throughout the equipment is thinning mechanism. The evaluation of the risk approach was done with the aim of reducing risk by optimizing the risk assessment activities.

  6. Limitation of radioactive discharges from NPP based on radionuclide specific monitoring

    International Nuclear Information System (INIS)

    Bucina, I.; Malatova, I.; Vidlakova, J.

    1998-01-01

    Monitoring of gaseous and liquid discharges from nuclear power plants based on particulate-iodine-gas measurements and gross beta or gamma plus tritium measurements is being improved by performing radionuclide specific measurements using semiconductor gamma and beta spectrometers and radiochemical methods. A new concept of regulatory effluent limits is being developed. The activities of all the relevant radionuclides discharged during a years, multiplied by the appropriate Sv/Bq conversion coefficient based on a standard multi-pathway model, are summed up, and the effective dose is compared with the new limit. Such limits should be laid down as the per capita collective commitment effective dose in the plant surroundings for atmospheric discharges, and as the committed effective dose to a critical group member for the hydrospheric releases

  7. Television viewing time as a risk factor for frailty and functional limitations in older adults: results from 2 European prospective cohorts.

    Science.gov (United States)

    García-Esquinas, Esther; Andrade, Elena; Martínez-Gómez, David; Caballero, Francisco Félix; López-García, Esther; Rodríguez-Artalejo, Fernando

    2017-04-26

    Sedentariness is an important risk factor for poor health. The main objective of this work was to examine the prospective association between television viewing time and indicators of physical function, mobility, agility, and frailty. Data came from two independent cohorts of community-dwelling older adults: the Seniors-ENRICA (n = 2392, 3.5 year follow-up), and the ELSA (n = 3989, 3.9 year follow-up). At baseline, television viewing and other sedentary behaviors were ascertained using interviewer-administered questionnaires. In the Seniors-ENRICA cohort overall physical function at baseline and follow-up was assessed using the physical component summary (PCS) of the SF-12 Health Survey. Measures for incident mobility and agility limitations in both cohorts were based on standardized questions, and incident frailty was measured with the Fried criteria. Analyses were adjusted for the main confounders, including physical activity at baseline. Results across cohorts were pooled using a random effects model. Lower (worse) scores in the PCS were observed among those in the highest (vs. the lowest) tertile of television viewing time (b-coefficient:-1.66; 95% confidence interval:-2.81,-0.52; p-trend = 0.01). Moreover, the pooled odds ratios (95% CIs) for mobility limitations for the second and third (vs. the lowest) tertile of television viewing were 1.00 (0.84, 1.20) and 1.17 (1.00, 1.38); p-trend = 0.12, respectively. The corresponding results for agility limitations were 1.18 (0.97, 1.44) and 1.25 (1.03, 1.51); p-trend = 0.02. Results for incident frailty were 1.10 (0.80, 1.51) and 1.47 (1.09, 1.97); p-trend = 0.03. No association between other types of sedentary behavior (time seated at the computer, while commuting, lying in the sun, listening to music/reading, internet use) and risk of functional limitations was found. Among older adults, longer television viewing time is prospectively associated with limitations in physical function

  8. Application of risk-based inspection methods for cryogenic equipment

    CERN Multimedia

    CERN. Geneva

    2016-01-01

    Risk-based Inspection (RBI) is widely applied across the world as part of Pressure Equipment Integrity Management, especially in the oil and gas industry, to generally reduce costs compared with time-based approaches and assist in assigning resources to the most critical equipment. One of the challenges in RBI is to apply it for low temperature and cryogenic applications, as there are usually no degradation mechanisms by which to determine a suitable probability of failure in the overall risk assessment. However, the assumptions used for other degradation mechanisms can be adopted to determine, qualitatively and semi-quantitatively, a consequence of failure within the risk assessment. This can assist in providing a consistent basis for the assumptions used in ensuring adequate process safety barriers and determining suitable sizing of relief devices. This presentation will discuss risk-based inspection in the context of cryogenic safety, as well as present some of the considerations for the risk assessme...

  9. Risk-based classification system of nanomaterials

    Energy Technology Data Exchange (ETDEWEB)

    Tervonen, Tommi, E-mail: t.p.tervonen@rug.n [University of Groningen, Faculty of Economics and Business (Netherlands); Linkov, Igor, E-mail: igor.linkov@usace.army.mi [US Army Research and Development Center (United States); Figueira, Jose Rui, E-mail: figueira@ist.utl.p [Technical University of Lisbon, CEG-IST, Centre for Management Studies, Instituto Superior Tecnico (Portugal); Steevens, Jeffery, E-mail: jeffery.a.steevens@usace.army.mil; Chappell, Mark, E-mail: mark.a.chappell@usace.army.mi [US Army Research and Development Center (United States); Merad, Myriam, E-mail: myriam.merad@ineris.f [INERIS BP 2, Societal Management of Risks Unit/Accidental Risks Division (France)

    2009-05-15

    Various stakeholders are increasingly interested in the potential toxicity and other risks associated with nanomaterials throughout the different stages of a product's life cycle (e.g., development, production, use, disposal). Risk assessment methods and tools developed and applied to chemical and biological materials may not be readily adaptable for nanomaterials because of the current uncertainty in identifying the relevant physico-chemical and biological properties that adequately describe the materials. Such uncertainty is further driven by the substantial variations in the properties of the original material due to variable manufacturing processes employed in nanomaterial production. To guide scientists and engineers in nanomaterial research and application as well as to promote the safe handling and use of these materials, we propose a decision support system for classifying nanomaterials into different risk categories. The classification system is based on a set of performance metrics that measure both the toxicity and physico-chemical characteristics of the original materials, as well as the expected environmental impacts through the product life cycle. Stochastic multicriteria acceptability analysis (SMAA-TRI), a formal decision analysis method, was used as the foundation for this task. This method allowed us to cluster various nanomaterials in different ecological risk categories based on our current knowledge of nanomaterial physico-chemical characteristics, variation in produced material, and best professional judgments. SMAA-TRI uses Monte Carlo simulations to explore all feasible values for weights, criteria measurements, and other model parameters to assess the robustness of nanomaterial grouping for risk management purposes.

  10. Model based risk assessment - the CORAS framework

    Energy Technology Data Exchange (ETDEWEB)

    Gran, Bjoern Axel; Fredriksen, Rune; Thunem, Atoosa P-J.

    2004-04-15

    Traditional risk analysis and assessment is based on failure-oriented models of the system. In contrast to this, model-based risk assessment (MBRA) utilizes success-oriented models describing all intended system aspects, including functional, operational and organizational aspects of the target. The target models are then used as input sources for complementary risk analysis and assessment techniques, as well as a basis for the documentation of the assessment results. The EU-funded CORAS project developed a tool-supported methodology for the application of MBRA in security-critical systems. The methodology has been tested with successful outcome through a series of seven trial within the telemedicine and ecommerce areas. The CORAS project in general and the CORAS application of MBRA in particular have contributed positively to the visibility of model-based risk assessment and thus to the disclosure of several potentials for further exploitation of various aspects within this important research field. In that connection, the CORAS methodology's possibilities for further improvement towards utilization in more complex architectures and also in other application domains such as the nuclear field can be addressed. The latter calls for adapting the framework to address nuclear standards such as IEC 60880 and IEC 61513. For this development we recommend applying a trial driven approach within the nuclear field. The tool supported approach for combining risk analysis and system development also fits well with the HRP proposal for developing an Integrated Design Environment (IDE) providing efficient methods and tools to support control room systems design. (Author)

  11. 12 CFR 652.65 - Risk-based capital stress test.

    Science.gov (United States)

    2010-01-01

    ...) You will use Corporation loan-level data to implement the credit risk component of the risk-based... Service corporate income tax schedule, as further described in appendix A to this subpart. (b) Credit risk. The credit risk part estimates loan losses during a period of sustained economic stress. (1) For each...

  12. An Evidence Base for Human Spaceflight Risks in Wikipedia

    Science.gov (United States)

    Kundrot, Craig; Steil, Jennifer; Lumpkins, Sarah; Pellis, Neal

    2013-01-01

    NASA's Human Research Program (HRP) is focused on understanding and mitigating thirty two risks to crew health and performance in exploration missions beyond low Earth orbit. The HRP has developed an evidence report for each of the risks. Most evidence reports are a brief review article describing the evidence related to a specified risk, written at a level appropriate for the scientifically educated, non-specialist reader. Each evidence report captured the current state of knowledge from both research and operations. Two limitations of the evidence reports have become apparent: 1) they are updated infrequently and 2) they do not take full advantage of the expertise available in other space agencies and in related fields of terrestrial research. Therefore, the HRP is experimenting with the use of Wikipedia articles as a repository for evidence. Wikipedia's accessibility to the international space flight community and researchers in related terrestrial fields creates the opportunity to generate a more timely and comprehensive evidence base. Initial Wikipedia articles were populated for seven risks using a subset of the information in the HRP-approved evidence reports: Fatigue and Sleep Loss, Treating An Ill or Injured Crew Member, Radiation Carcinogenesis, Visual Impairment and Intracranial Pressure, Renal Stone Formation, Team Cohesion, and Intervertebral Disc Damage. Since the initial articles were created, there have been additions to these Wikipedia articles, including content from sources outside the HRP, and editorial changes to the pages. We will report on the nature of the contributions made after the initial articles were created, the comprehensiveness of the resulting Wikipedia articles, and the effort required to maintain quality control of the content. The Wikipedia approach will also be compared to wiki efforts that exert more traditional editorial control of content prior to posting.

  13. Use of results of microbiological analyses for risk-based control of Listeria monocytogenes in marinated broiler legs.

    Science.gov (United States)

    Aarnisalo, Kaarina; Vihavainen, Elina; Rantala, Leila; Maijala, Riitta; Suihko, Maija-Liisa; Hielm, Sebastian; Tuominen, Pirkko; Ranta, Jukka; Raaska, Laura

    2008-02-10

    Microbial risk assessment provides a means of estimating consumer risks associated with food products. The methods can also be applied at the plant level. In this study results of microbiological analyses were used to develop a robust single plant level risk assessment. Furthermore, the prevalence and numbers of Listeria monocytogenes in marinated broiler legs in Finland were estimated. These estimates were based on information on the prevalence, numbers and genotypes of L. monocytogenes in 186 marinated broiler legs from 41 retail stores. The products were from three main Finnish producers, which produce 90% of all marinated broiler legs sold in Finland. The prevalence and numbers of L. monocytogenes were estimated by Monte Carlo simulation using WinBUGS, but the model is applicable to any software featuring standard probability distributions. The estimated mean annual number of L. monocytogenes-positive broiler legs sold in Finland was 7.2x10(6) with a 95% credible interval (CI) 6.7x10(6)-7.7x10(6). That would be 34%+/-1% of the marinated broiler legs sold in Finland. The mean number of L. monocytogenes in marinated broiler legs estimated at the sell-by-date was 2 CFU/g, with a 95% CI of 0-14 CFU/g. Producer-specific L. monocytogenes strains were recovered from the products throughout the year, which emphasizes the importance of characterizing the isolates and identifying strains that may cause problems as part of risk assessment studies. As the levels of L. monocytogenes were low, the risk of acquiring listeriosis from these products proved to be insignificant. Consequently there was no need for a thorough national level risk assessment. However, an approach using worst-case and average point estimates was applied to produce an example of single producer level risk assessment based on limited data. This assessment also indicated that the risk from these products was low. The risk-based approach presented in this work can provide estimation of public health risk

  14. Dose limits

    International Nuclear Information System (INIS)

    Fitoussi, L.

    1987-12-01

    The dose limit is defined to be the level of harmfulness which must not be exceeded, so that an activity can be exercised in a regular manner without running a risk unacceptable to man and the society. The paper examines the effects of radiation categorised into stochastic and non-stochastic. Dose limits for workers and the public are discussed

  15. The association of hospital prevention processes and patient risk factors with the risk of Clostridium difficile infection: a population-based cohort study.

    Science.gov (United States)

    Daneman, N; Guttmann, A; Wang, X; Ma, X; Gibson, D; Stukel, T A

    2015-07-01

    Clostridium difficile is the most common cause of healthcare-acquired infection; the real-world impacts of some proposed C. difficile prevention processes are unknown. We conducted a population-based retrospective cohort study of all patients admitted to acute care hospitals between April 2011 and March 2012 in Ontario, Canada. Hospital prevention practices were determined by survey of infection control programmes; responses were linked to patient-level risk factors and C. difficile outcomes in Ontario administrative databases. Multivariable generalised estimating equation (GEE) regression models were used to assess the impact of selected understudied hospital prevention processes on the patient-level risk of C. difficile infection, accounting for patient risk factors, baseline C. difficile rates and structural hospital characteristics. C. difficile infections complicated 2341 of 653 896 admissions (3.6 per 1000 admissions). Implementation of the selected C. difficile prevention practices was variable across the 159 hospitals with isolation of all patients at onset of diarrhoea reported by 43 (27%), auditing of antibiotic stewardship compliance by 26 (16%), auditing of cleaning practices by 115 (72%), on-site diagnostic testing by 74 (47%), vancomycin as first-line treatment by 24 (15%) and reporting rates to senior leadership by 52 (33%). None of these processes were associated with a significantly reduced risk of C. difficile after adjustment for baseline C. difficile rates, structural hospital characteristics and patient-level factors. Patient-level factors were strongly associated with C. difficile risk, including age, comorbidities, non-elective and medical admissions. In the largest study to date, selected hospital prevention strategies were not associated with a statistically significant reduction in patients' risk of C. difficile infection. These prevention strategies have either limited effectiveness or were ineffectively implemented during the study

  16. Probabilistic risk analysis and terrorism risk.

    Science.gov (United States)

    Ezell, Barry Charles; Bennett, Steven P; von Winterfeldt, Detlof; Sokolowski, John; Collins, Andrew J

    2010-04-01

    Since the terrorist attacks of September 11, 2001, and the subsequent establishment of the U.S. Department of Homeland Security (DHS), considerable efforts have been made to estimate the risks of terrorism and the cost effectiveness of security policies to reduce these risks. DHS, industry, and the academic risk analysis communities have all invested heavily in the development of tools and approaches that can assist decisionmakers in effectively allocating limited resources across the vast array of potential investments that could mitigate risks from terrorism and other threats to the homeland. Decisionmakers demand models, analyses, and decision support that are useful for this task and based on the state of the art. Since terrorism risk analysis is new, no single method is likely to meet this challenge. In this article we explore a number of existing and potential approaches for terrorism risk analysis, focusing particularly on recent discussions regarding the applicability of probabilistic and decision analytic approaches to bioterrorism risks and the Bioterrorism Risk Assessment methodology used by the DHS and criticized by the National Academies and others.

  17. Canadian population risk of radon induced lung cancer variation range assessment based on various radon risk models

    International Nuclear Information System (INIS)

    Chen, Jing

    2017-01-01

    To address public concerns regarding radon risk and variations in risk estimates based on various risk models available in the literature, lifetime lung cancer risks were calculated with five well-known risk models using more recent Canadian vital statistics (5-year averages from 2008 to 2012). Variations in population risk estimation among various models were assessed. The results showed that the Canadian population risk of radon induced lung cancer can vary from 5.0 to 17% for men and 5.1 to 18% for women based on different radon risk models. Averaged over the estimates from various risk models with better radon dosimetry, 13% of lung cancer deaths among Canadian males and 14% of lung cancer deaths among Canadian females were attributable to long-term indoor radon exposure. (authors)

  18. Risk-Based Approach for Thermal Treatment of Soils Contaminated with Heavy Metals

    Directory of Open Access Journals (Sweden)

    Cocârţă D. M.

    2013-04-01

    Full Text Available In the actual context of limited soil resources and the significant degree of environmental pollution, public administrations and authorities are interested in restoring contaminated sites paying attention to the impact of these soils on human health. This paper aims to present the efficiency of the the incineration as a method for treatment of the contaminated soils t based on human health risk assessment. Through various experimentations, the following metals have been studied: Zn, Cu, Fe, Mn, Ni, Pb, Cr, Co, Cd, Hg, As and Be. The most important and interesting results concerning both thermal treatment removal efficiency and associated human health risk assessments were achieved concerning Cd, Pb and Ni contaminants. The behavior of Cadmium (Cd, Lead (Pb and Nickel (Ni concentrations from heavy metals incineration soil has been analyzed for three incineration temperatures (600°C, 800°C and 1000°C and two resident times of soil within the incineration reactor (30 min. and 60 min.. In this case, the level of contaminants in the treated soil can be reduced but not enough to ensure an acceptable risk for human health.

  19. Research needs for risk-informed, performance-based regulation

    International Nuclear Information System (INIS)

    Cloninger, T.H.

    1997-01-01

    This presentation was made by an executive in the utility which operates the South Texas Project reactors, and summarizes their perspective on probabilistic safety analysis, risk-based operation, and risk-based regulation. They view it as a tool to help them better apply their resources to maintain the level of safety necessary to protect the public health and safety. South Texas served as one of the pilot plants for the application of risk-based regulation to the maintenance rule. The author feels that the process presents opportunities as well as challenges. Among the opportunities is the involvement of more people in the process, and the sense of investment they take in the decisions, in addition to the insight they can offer. In the area of challenges there is the need for better understanding of how to apply what already is known on problems, rather than essentially reinventing the wheel to address problems. Research is needed to better understand when some events are not truly of a significant safety concern. The demarcation between deterministic decisions and the appropriate application of risk-based decisions must be better defined, for the sake of the operator as well as the public observing plant operation

  20. Quantified Risk Ranking Model for Condition-Based Risk and Reliability Centered Maintenance

    Science.gov (United States)

    Chattopadhyaya, Pradip Kumar; Basu, Sushil Kumar; Majumdar, Manik Chandra

    2017-06-01

    In the recent past, risk and reliability centered maintenance (RRCM) framework is introduced with a shift in the methodological focus from reliability and probabilities (expected values) to reliability, uncertainty and risk. In this paper authors explain a novel methodology for risk quantification and ranking the critical items for prioritizing the maintenance actions on the basis of condition-based risk and reliability centered maintenance (CBRRCM). The critical items are identified through criticality analysis of RPN values of items of a system and the maintenance significant precipitating factors (MSPF) of items are evaluated. The criticality of risk is assessed using three risk coefficients. The likelihood risk coefficient treats the probability as a fuzzy number. The abstract risk coefficient deduces risk influenced by uncertainty, sensitivity besides other factors. The third risk coefficient is called hazardous risk coefficient, which is due to anticipated hazards which may occur in the future and the risk is deduced from criteria of consequences on safety, environment, maintenance and economic risks with corresponding cost for consequences. The characteristic values of all the three risk coefficients are obtained with a particular test. With few more tests on the system, the values may change significantly within controlling range of each coefficient, hence `random number simulation' is resorted to obtain one distinctive value for each coefficient. The risk coefficients are statistically added to obtain final risk coefficient of each critical item and then the final rankings of critical items are estimated. The prioritization in ranking of critical items using the developed mathematical model for risk assessment shall be useful in optimization of financial losses and timing of maintenance actions.

  1. The risk-based approach to anti-money laundering: problems and solutions

    DEFF Research Database (Denmark)

    Simonova, Anna

    2011-01-01

    Purpose – The purpose of this paper, which is a part of a PhD thesis, is to detect problems associated with the risk-based approach to anti-money laundering (AML), as well as present ways to improve the risk-based approach. Design/methodology/approach – The method is law and economics. The Ph......D thesis itself is also based on a comparative analysis of the Danish and British AML regimes. Findings – The main findings are: failure to develop adequate risk-based AML systems, taking into account varying levels of money laundering risk, is not only to be considered in the context of legal risk...... but also and more importantly in the context of integrity risk; anti-money laundering (AML) has to be made part of financial and non-financial institutions' corporate social responsibility policies; the Risk Analysis Manual provided by the Central Bank of The Netherlands lists very specific...

  2. Improving cluster-based methods for investigating potential for insect pest species establishment: region-specific risk factors

    Directory of Open Access Journals (Sweden)

    Michael J. Watts

    2011-09-01

    Full Text Available Existing cluster-based methods for investigating insect species assemblages or profiles of a region to indicate the risk of new insect pest invasion have a major limitation in that they assign the same species risk factors to each region in a cluster. Clearly regions assigned to the same cluster have different degrees of similarity with respect to their species profile or assemblage. This study addresses this concern by applying weighting factors to the cluster elements used to calculate regional risk factors, thereby producing region-specific risk factors. Using a database of the global distribution of crop insect pest species, we found that we were able to produce highly differentiated region-specific risk factors for insect pests. We did this by weighting cluster elements by their Euclidean distance from the target region. Using this approach meant that risk weightings were derived that were more realistic, as they were specific to the pest profile or species assemblage of each region. This weighting method provides an improved tool for estimating the potential invasion risk posed by exotic species given that they have an opportunity to establish in a target region.

  3. Spirometry, questionnaire and electronic medical record based COPD in a population survey: Comparing prevalence, level of agreement and associations with potential risk factors.

    Science.gov (United States)

    Borlée, Floor; Yzermans, C Joris; Krop, Esmeralda; Aalders, Bernadette; Rooijackers, Jos; Zock, Jan-Paul; van Dijk, Christel E; Maassen, Catharina B M; Schellevis, François; Heederik, Dick; Smit, Lidwien A M

    2017-01-01

    COPD-diagnosis is confirmed by post-bronchodilator (BD) spirometry. However, epidemiological studies often rely on pre-BD spirometry, self-reports, or medical records. This population-based study aims to determine COPD-prevalence based on four different operational definitions and their level of agreement, and to compare associations between COPD-definitions and risk factors. COPD-prevalence in 1,793 adults from the general Dutch population (aged 18-70 years) was assessed based on self-reported data, Electronic Medical Records (EMR), and post-BD spirometry: using the FEV1/FVC below the lower limit of normal (LLN) and GOLD fixed cut-off (FEV1/FVC spirometry as a reference, sensitivity was calculated for self-reported and EMR-based COPD. Associations between COPD and known risk factors were assessed with logistic regression. Data were collected as part of the cross-sectional VGO study (Livestock Farming and Neighboring Residents' Health Study). The highest prevalence was found based on spirometry (GOLD: 10.9%, LLN: 5.9%), followed by self-report (4.6%) and EMR (2.9%). Self-reported or EMR-based COPD identified less than 30% of all COPD-cases based on spirometry. The direction of association between known risk factors and COPD was similar across the four definitions, however, magnitude and significance varied. Especially indicators of allergy were more strongly associated with self-reported COPD compared to the other definitions. COPD-prevalence varied depending on the used definition. A substantial number of subjects with spirometry-based COPD cannot be identified with questionnaires or medical records which can cause underestimation of COPD-prevalence. The influence of the different COPD-definitions on associations with known risk factors was limited.

  4. Routine culture-based screening versus risk-based management for the prevention of early-onset group B streptococcus disease in the neonate: a systematic review.

    Science.gov (United States)

    Kurz, Ella; Davis, Deborah

    2015-04-17

    Early-onset group B streptococcus disease, recognized as the most common cause of early onset neonatal sepsis in developed countries, is transmitted vertically from the group B streptococcus carrier mother to the neonate in the peripartum. Accordingly, early-onset group B streptococcus disease is prevented by halting the transmission of the microorganism from the mother to the infant. Two main methods, routine culture-based screening and risk-based management, may be used in the identification of mothers requiring intrapartum antibiotic prophylaxis in labor. While there are advantages and disadvantages to each, there is limited high level evidence available as to which method is superior. To identify the effectiveness of risk-based management versus routine culture-based screening in the prevention of early-onset group B streptococcus disease in the neonate. This review considered studies which treated pregnant women with intrapartum antibiotic prophylaxis following risk- and culture-based protocols for the prevention of early-onset group B streptococcus disease in the neonate. Types of intervention: This review considered studies that evaluated risk-based management against routine culture-based screening for the prevention of early-onset group B streptococcus disease in the neonate. Types of studies: This review looked for highest evidence available which in this case consisted of one quasi experimental study and eight comparative cohort studies with historical or concurrent control groups. Types of outcomes: Incidence of early-onset group B streptococcus disease in neonates as measured by positive group B streptococcus culture from an otherwise sterile site. Secondary outcomes include neonatal death due to group B streptococcus sepsis and percentage of women who received intrapartum antibiotic prophylaxis. A multi-step search strategy was used to find studies which were limited to the English language and published between January 2000 and June 2013. The quality

  5. Probabilistic safety and risk assessments in the field of nuclear technology - Mode of operation, possibilities and limits

    International Nuclear Information System (INIS)

    Mertens, J.

    1993-01-01

    In this study probabilistic safety and risk assessments in the field of nuclear energy are explained. Mainly qualitative results and conclusions are presented. Explanations for often discussed aspects of such analysis reveal the procedure and reasonable limits of application. The mentioned literature contains detailed results. (orig./DG) [de

  6. Big data based fraud risk management at Alibaba

    OpenAIRE

    Chen, Jidong; Tao, Ye; Wang, Haoran; Chen, Tao

    2015-01-01

    With development of mobile internet and finance, fraud risk comes in all shapes and sizes. This paper is to introduce the Fraud Risk Management at Alibaba under big data. Alibaba has built a fraud risk monitoring and management system based on real-time big data processing and intelligent risk models. It captures fraud signals directly from huge amount data of user behaviors and network, analyzes them in real-time using machine learning, and accurately predicts the bad users and transactions....

  7. Options for improving hazardous waste cleanups using risk-based criteria

    International Nuclear Information System (INIS)

    Elcock, D.

    1995-01-01

    This paper explores how risk- and technology-based criteria are currently used in the RCRA and CERCLA cleanup programs. It identifies ways in which risk could be further incorporated into RCRA and CERCLA cleanup requirements and the implications of risk-based approaches. The more universal use of risk assessment as embodied in the risk communication and risk improvement bills before Congress is not addressed. Incorporating risk into the laws and regulations governing hazardous waste cleanup, will allow the use of the best scientific information available to further the goal of environmental protection in the United States while containing costs. and may help set an example for other countries that may be developing cleanup programs, thereby contributing to enhanced global environmental management

  8. Developing an objective evaluation method to estimate diabetes risk in community-based settings.

    Science.gov (United States)

    Kenya, Sonjia; He, Qing; Fullilove, Robert; Kotler, Donald P

    2011-05-01

    Exercise interventions often aim to affect abdominal obesity and glucose tolerance, two significant risk factors for type 2 diabetes. Because of limited financial and clinical resources in community and university-based environments, intervention effects are often measured with interviews or questionnaires and correlated with weight loss or body fat indicated by body bioimpedence analysis (BIA). However, self-reported assessments are subject to high levels of bias and low levels of reliability. Because obesity and body fat are correlated with diabetes at different levels in various ethnic groups, data reflecting changes in weight or fat do not necessarily indicate changes in diabetes risk. To determine how exercise interventions affect diabetes risk in community and university-based settings, improved evaluation methods are warranted. We compared a noninvasive, objective measurement technique--regional BIA--with whole-body BIA for its ability to assess abdominal obesity and predict glucose tolerance in 39 women. To determine regional BIA's utility in predicting glucose, we tested the association between the regional BIA method and blood glucose levels. Regional BIA estimates of abdominal fat area were significantly correlated (r = 0.554, P < 0.003) with fasting glucose. When waist circumference and family history of diabetes were added to abdominal fat in multiple regression models, the association with glucose increased further (r = 0.701, P < 0.001). Regional BIA estimates of abdominal fat may predict fasting glucose better than whole-body BIA as well as provide an objective assessment of changes in diabetes risk achieved through physical activity interventions in community settings.

  9. Synthesis of Enterprise and Value-Based Methods for Multiattribute Risk Analysis

    International Nuclear Information System (INIS)

    Kenley, C. Robert; Collins, John W.; Beck, John M.; Heydt, Harold J.; Garcia, Chad B.

    2001-01-01

    This paper describes a method for performing multiattribute decision analysis to prioritize ap-proaches to handling risks during the development and operation of complex socio-technical systems. The method combines risk categorization based on enterprise views, risk prioritization of the categories based on the Analytic Hierarchy Process (AHP), and more standard probability-consequence ratings schemes. We also apply value-based testing me-thods used in software development to prioritize risk-handling approaches. We describe a tool that synthesizes the methods and performs a multiattribute analysis of the technical and pro-grammatic risks on the Next Generation Nuclear Plant (NGNP) enterprise.

  10. Sibship structure and risk of infectious mononucleosis: a population-based cohort study.

    Science.gov (United States)

    Rostgaard, Klaus; Nielsen, Trine Rasmussen; Wohlfahrt, Jan; Ullum, Henrik; Pedersen, Ole; Erikstrup, Christian; Nielsen, Lars Peter; Hjalgrim, Henrik

    2014-10-01

    Present understanding of increased risk of Epstein-Barr virus (EBV)-related infectious mononucleosis among children of low birth order or small sibships is mainly based on old and indirect evidence. Societal changes and methodological limitations of previous studies call for new data. We used data from the Danish Civil Registration System and the Danish National Hospital Discharge Register to study incidence rates of inpatient hospitalizations for infectious mononucleosis before the age of 20 years in a cohort of 2,543,225 Danes born between 1971 and 2008, taking individual sibship structure into account. A total of 12,872 cases of infectious mononucleosis were observed during 35.3 million person-years of follow-up. Statistical modelling showed that increasing sibship size was associated with a reduced risk of infectious mononucleosis and that younger siblings conferred more protection from infectious mononucleosis than older siblings. In addition to this general association with younger and older siblings, children aged less than 4 years transiently increased their siblings’ infectious mononucleosis risk. Our results were confirmed in an independent sample of blood donors followed up retrospectively for self-reported infectious mononucleosis. Younger siblings, and to a lesser degree older siblings, seem to be important in the transmission of EBV within families. Apparently the dogma of low birth order in a sibship as being at the highest risk of infectious mononucleosis is no longer valid.

  11. Risk-based indicators of Canadians' exposures to environmental carcinogens.

    Science.gov (United States)

    Setton, Eleanor; Hystad, Perry; Poplawski, Karla; Cheasley, Roslyn; Cervantes-Larios, Alejandro; Keller, C Peter; Demers, Paul A

    2013-02-12

    Tools for estimating population exposures to environmental carcinogens are required to support evidence-based policies to reduce chronic exposures and associated cancers. Our objective was to develop indicators of population exposure to selected environmental carcinogens that can be easily updated over time, and allow comparisons and prioritization between different carcinogens and exposure pathways. We employed a risk assessment-based approach to produce screening-level estimates of lifetime excess cancer risk for selected substances listed as known carcinogens by the International Agency for Research on Cancer. Estimates of lifetime average daily intake were calculated using population characteristics combined with concentrations (circa 2006) in outdoor air, indoor air, dust, drinking water, and food and beverages from existing monitoring databases or comprehensive literature reviews. Intake estimates were then multiplied by cancer potency factors from Health Canada, the United States Environmental Protection Agency, and the California Office of Environmental Health Hazard Assessment to estimate lifetime excess cancer risks associated with each substance and exposure pathway. Lifetime excess cancer risks in excess of 1 per million people are identified as potential priorities for further attention. Based on data representing average conditions circa 2006, a total of 18 carcinogen-exposure pathways had potential lifetime excess cancer risks greater than 1 per million, based on varying data quality. Carcinogens with moderate to high data quality and lifetime excess cancer risk greater than 1 per million included benzene, 1,3-butadiene and radon in outdoor air; benzene and radon in indoor air; and arsenic and hexavalent chromium in drinking water. Important data gaps were identified for asbestos, hexavalent chromium and diesel exhaust in outdoor and indoor air, while little data were available to assess risk for substances in dust, food and beverages. The ability to

  12. Particular aspects and limits of absolute nuclear liability

    International Nuclear Information System (INIS)

    Engelhard, M.; Brunengo, C.

    1981-10-01

    Ambiguities subsist concerning the application limits of conventional non-nuclear liability and nuclear liability. Based on three examples where the system of channelling liability onto the operator of a nuclear installation is not applied: holder of low-risk nuclear products or materials; nuclear/supplier contractual relations; and nuclear operator/third party relations, this paper outlines some practical solutions to the problems met. The solutions considered concern: suppression of nuclear risk exclusions in policies underwritten by persons who do not take part in the nuclear activity and generalizing and strengthening of the channelling of the nuclear risk onto the operator as well as creation of ''bridges'' between the existing Conventions. (NEA) [fr

  13. Existing Regulatory Approaches to Reducing Exposures to Chemical- and Product-Based Risk and Their Applicability to Diet-Related Chronic Disease.

    Science.gov (United States)

    Cohen, Deborah A; Knopman, Debra S

    2018-04-17

    We aimed to identify and categorize the types of policies that have been adopted to protect Americans from harmful exposures that could also be relevant for addressing diet-related chronic diseases. This article examines and categorizes the rationales behind government regulation. Our interest in the historical analysis is to inform judgments about how best to address newly emergent risks involving diet-related chronic disease within existing regulatory and information-based frameworks. We assessed exemplars of regulation with respect to harmful exposures from air, water, and food, as well as regulations that are intended to modify voluntary behaviors. Following the comparative analysis, we explored how exposures that lead to diet-related chronic diseases among the general population fit within models of regulation adopted for other comparable risks. We identified five rationales and five approaches that protect people from harmful exposures. Reasons for regulation include: protection from involuntary exposure to risk, high risk of death or chronic illness, ubiquity of risk, counteraction to limit compulsive behaviors, and promotion of population health. Regulatory approaches include: mandatory limits on use, mandatory limits on exposure, mandatory controls on quality, mandatory labeling, and voluntary guidance. In contrast to the use of mandates, the prevention of diet-related chronic diseases thus far has largely relied on information-only approaches and voluntary adoption of guidelines. There is ample precedent for mandatory regulatory approaches that could address harms related to exposure to unhealthy diets, but several barriers to action would need to be overcome. © 2018 Society for Risk Analysis.

  14. Beam-limiting and radiation-limiting interlocks

    International Nuclear Information System (INIS)

    Macek, R.J.

    1996-01-01

    This paper reviews several aspects of beam-limiting and radiation- limiting interlocks used for personnel protection at high-intensity accelerators. It is based heavily on the experience at the Los Alamos Neutron Science Center (LANSCE) where instrumentation-based protection is used extensively. Topics include the need for ''active'' protection systems, system requirements, design criteria, and means of achieving and assessing acceptable reliability. The experience with several specific devices (ion chamber-based beam loss interlock, beam current limiter interlock, and neutron radiation interlock) designed and/or deployed to these requirements and criteria is evaluated

  15. Limitations of the planning organ at risk volume (PRV) concept.

    Science.gov (United States)

    Stroom, Joep C; Heijmen, Ben J M

    2006-09-01

    Previously, we determined a planning target volume (PTV) margin recipe for geometrical errors in radiotherapy equal to M(T) = 2 Sigma + 0.7 sigma, with Sigma and sigma standard deviations describing systematic and random errors, respectively. In this paper, we investigated margins for organs at risk (OAR), yielding the so-called planning organ at risk volume (PRV). For critical organs with a maximum dose (D(max)) constraint, we calculated margins such that D(max) in the PRV is equal to the motion averaged D(max) in the (moving) clinical target volume (CTV). We studied margins for the spinal cord in 10 head-and-neck cases and 10 lung cases, each with two different clinical plans. For critical organs with a dose-volume constraint, we also investigated whether a margin recipe was feasible. For the 20 spinal cords considered, the average margin recipe found was: M(R) = 1.6 Sigma + 0.2 sigma with variations for systematic and random errors of 1.2 Sigma to 1.8 Sigma and -0.2 sigma to 0.6 sigma, respectively. The variations were due to differences in shape and position of the dose distributions with respect to the cords. The recipe also depended significantly on the volume definition of D(max). For critical organs with a dose-volume constraint, the PRV concept appears even less useful because a margin around, e.g., the rectum changes the volume in such a manner that dose-volume constraints stop making sense. The concept of PRV for planning of radiotherapy is of limited use. Therefore, alternative ways should be developed to include geometric uncertainties of OARs in radiotherapy planning.

  16. Rituals in risk evaluation for land-use planning

    NARCIS (Netherlands)

    Xanten, van N.H.W.; Pietersen, C.M.; Pasman, H.J.; Vrijling, H.K.; Kerstens, J.G.M.

    2013-01-01

    In Dutch external safety policy, the acceptance of risk for the population in areas surrounding hazardous substances establishments is based on a limit value for individual risk (IR). Additionally, changes to societal risk (SR) must be justified. A specific software program (SAFETI-NL) with the

  17. Project transition to risk based corrective action

    International Nuclear Information System (INIS)

    Judge, J.M.; Cormier, S.L.

    1996-01-01

    Many states have adopted or are considering the adoption of the America Society for Testing and Materials (ASTM) Standard E 1739, Standard for Risk Based Corrective Action (RBCA) Applied to Petroleum Release Sites. This standard is being adopted to regulate leaking underground storage tank (LUST) sites. The case studies of two LUST sites in Michigan will be presented to demonstrate the decision making process and limiting factors involved in transitioning sites to the RBCA program. Both of these case studies had been previously investigated and one was actively remediated. The first case study involves a private petroleum facility where soil and ground water have been impacted. Remediation involved a ground water pump and treat system. Subsequent monitoring during system operation indicated that analytical data were still above the Tier 1 RBSLs but below the Tier 2 SSTLs. The closure strategy that was developed was based on the compounds of concern that were below the SSTLs. A deed restriction was also developed for the site as an institutional control. The second LUST site exhibited BTEX concentrations in soil and ground water above the Tier 1 RBSLs. Due to the exceedence of the Tier 1 RBSLs, the second site required a Tier 2 assessment to develop SSTLs as remedial objectives and remove hot spots in the soil and treat the ground water to achieve closure. Again, a deed restriction was instituted along with a performance monitoring plan

  18. Functional limitations as potential mediators of the effects of self-reported vision status on fall risk of older adults.

    Science.gov (United States)

    Steinman, Bernard A; Allen, Susan M; Chen, Jie; Pynoos, Jon

    2015-02-01

    To test whether limitations in mobility and large-muscle functioning mediate self-reported vision status to increase fall risk among respondents age 65 and above. This study used two waves from the Health and Retirement Study. We conducted binary logistic and negative binomial regression analyses to test indirect paths leading from self-reported vision status to falls, via indices of mobility and large-muscle functioning. Limited evidence was found for a mediating effect among women; however, large-muscle groups were implicated as partially mediating risk factors for falls among men with fair self-reported vision status. Implications of these findings are discussed including the need for prioritizing improved muscle strength of older men and women with poor vision as a preventive measure against falls. © The Author(s) 2014.

  19. Risk-Based Operation and Maintenance of Offshore Wind Turbines

    DEFF Research Database (Denmark)

    Nielsen, Jannie Sønderkær

    to oil and gas structures. In addition, condition monitoring systems are often available, and the information should be taken into account when making decisions. In this thesis, methods for risk-based maintenance planning using Bayesian methods are investigated, with the aim of making optimal decisions......, but presently maintenance is not planned using advanced methods taking all available information into account in a consistent manner. Maintenance decisions can be made based on risk-based methods, where the total expected life cycle costs are minimized. Methods have been developed for assessing the corrective...... considering all available information. First, a theoretical damage model is formulated, the model is then updated using condition monitoring data, and the updated model is used as basis for risk-based decision making. Several approaches for solving the decision problems have been considered: various types...

  20. Waste-acceptance criteria and risk-based thinking for radioactive-waste classification

    International Nuclear Information System (INIS)

    Lowenthal, M.D.

    1998-01-01

    The US system of radioactive-waste classification and its development provide a reference point for the discussion of risk-based thinking in waste classification. The official US system is described and waste-acceptance criteria for disposal sites are introduced because they constitute a form of de facto waste classification. Risk-based classification is explored and it is found that a truly risk-based system is context-dependent: risk depends not only on the waste-management activity but, for some activities such as disposal, it depends on the specific physical context. Some of the elements of the official US system incorporate risk-based thinking, but like many proposed alternative schemes, the physical context of disposal is ignored. The waste-acceptance criteria for disposal sites do account for this context dependence and could be used as a risk-based classification scheme for disposal. While different classes would be necessary for different management activities, the waste-acceptance criteria would obviate the need for the current system and could better match wastes to disposal environments saving money or improving safety or both

  1. The role of hazard- and risk-based approaches in ensuring food safety

    OpenAIRE

    Barlow, Susan M.; Boobis, Alan R.; Bridges, Jim; Cockburn, Andrew; Dekant, Wolfgang; Hepburn, Paul; Houben, Geert F.; König, Jürgen; Nauta, Maarten; Schuermans, Jeroen; Bánáti, Diána

    2015-01-01

    BackgroundFood legislation in the European Union and elsewhere includes both hazard- and risk-based approaches for ensuring safety. In hazard-based approaches, simply the presence of a potentially harmful agent at a detectable level in food is used as a basis for legislation and/or risk management action. Risk-based approaches allow consideration of exposure in assessing whether there may be unacceptable risks to health.Scope and approachThe advantages and disadvantages of hazard- and risk-ba...

  2. Toxic chemical risk acceptance criteria

    International Nuclear Information System (INIS)

    Craig, D.K.; Davis, J.; Lee, L.; Lein, P.; Omberg, S.

    1992-01-01

    This paper presents recommendations of a subcommittee of the Westinghouse M ampersand 0 Nuclear Facility Safety Committee concerning toxic chemical risk acceptance criteria. Two sets of criteria have been developed, one for use in the hazard classification of facilities, and the second for use in comparing risks in DOE non-reactor nuclear facility Safety Analysis Reports. The Emergency Response Planning Guideline (ERPG) values are intended to provide estimates of concentration ranges for specific chemicals above which exposure would be expected to lead to adverse heath effects of increasing severity for ERPG-1, -2, and -3s. The subcommittee recommends that criteria for hazard class or risk range be based on ERPGs for all chemicals. Probability-based Incremental Cancer Risk (ICR) criteria are recommended for additional analyses of risks from all known or suspected human carcinogens. Criteria are given for both on-site and off-site exposure. The subcommittee also recommends that the 5-minute peak concentration be compared with the relevant criterion with no adjustment for exposure time. Since ERPGs are available for only a limited number of chemicals, the subcommittee has developed a proposed hierarchy of concentration limit parameters for the different criteria

  3. Risk-based inspection in the context of nuclear power plants

    Energy Technology Data Exchange (ETDEWEB)

    Soares, Wellington A.; Vasconcelos, Vanderley de; Rabello, Emerson G., E-mail: soaresw@cdtn.br, E-mail: vasconv@cdtn.br, E-mail: egr@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2015-07-01

    Nuclear power plant owners have to consider several aspects like safety, availability, costs and radiation exposure during operation of nuclear power plants. They also need to demonstrate to regulatory bodies that risk assessment and inspection planning processes are being implemented in effective and appropriate manner. Risk-Based Inspection (RBI) is a methodology that, unlike time-based inspection, involves a quantitative assessment of both failure probability and consequence associated with each safety-related item. A correctly implemented RBI program classifies individual equipment by its risks and prioritizes inspection efforts based on this classification. While in traditional deterministic approach, the inspection frequencies are constant, in the RBI approach the inspection interval for each item depends on the risk level. Regularly, inspection intervals from RBI result in risk levels lower or equal than deterministic inspection intervals. According to the literature, RBI solutions improve integrity and reduce costs through a more effective inspection. Risk-Informed In-service Inspection (RI-ISI) is the equivalent term used in the nuclear area. Its use in nuclear power plants around world is briefly reviewed in this paper. Identification of practice methodologies for performing risk-based analyses presented in this paper can help both Brazilian nuclear power plant operator and regulatory body in evaluating the RI-ISI technique feasibility as a tool for optimizing inspections within nuclear plants. (author)

  4. Risk-based inspection in the context of nuclear power plants

    International Nuclear Information System (INIS)

    Soares, Wellington A.; Vasconcelos, Vanderley de; Rabello, Emerson G.

    2015-01-01

    Nuclear power plant owners have to consider several aspects like safety, availability, costs and radiation exposure during operation of nuclear power plants. They also need to demonstrate to regulatory bodies that risk assessment and inspection planning processes are being implemented in effective and appropriate manner. Risk-Based Inspection (RBI) is a methodology that, unlike time-based inspection, involves a quantitative assessment of both failure probability and consequence associated with each safety-related item. A correctly implemented RBI program classifies individual equipment by its risks and prioritizes inspection efforts based on this classification. While in traditional deterministic approach, the inspection frequencies are constant, in the RBI approach the inspection interval for each item depends on the risk level. Regularly, inspection intervals from RBI result in risk levels lower or equal than deterministic inspection intervals. According to the literature, RBI solutions improve integrity and reduce costs through a more effective inspection. Risk-Informed In-service Inspection (RI-ISI) is the equivalent term used in the nuclear area. Its use in nuclear power plants around world is briefly reviewed in this paper. Identification of practice methodologies for performing risk-based analyses presented in this paper can help both Brazilian nuclear power plant operator and regulatory body in evaluating the RI-ISI technique feasibility as a tool for optimizing inspections within nuclear plants. (author)

  5. Comparative performance of diabetes-specific and general population-based cardiovascular risk assessment models in people with diabetes mellitus.

    Science.gov (United States)

    Echouffo-Tcheugui, J-B; Kengne, A P

    2013-10-01

    Multivariable models for estimating cardiovascular disease (CVD) risk in people with diabetes comprise general population-based models and those from diabetic cohorts. Whether one set of models should receive preference is unclear. We evaluated the evidence on direct comparisons of the performance of general population vs diabetes-specific CVD risk models in people with diabetes. MEDLINE and EMBASE databases were searched up to March 2013. Two reviewers independently identified studies that compared the performance of general CVD models vs diabetes-specific ones in the same group of people with diabetes. Independent, dual data extraction on study design, risk models, outcomes; and measures of performance was conducted. Eleven articles reporting on 22 pair wise comparisons of a diabetes-specific model (UKPDS, ADVANCE and DCS risk models) to a general population model (three variants of the Framingham model, Prospective Cardiovascular Münster [PROCAM] score, CardioRisk Manager [CRM], Joint British Societies Coronary Risk Chart [JBSRC], Progetto Cuore algorithm and the CHD-Riskard algorithm) were eligible. Absolute differences in C-statistic of diabetes-specific vs general population-based models varied from -0.13 to 0.09. Comparisons for other performance measures were unusual. Outcomes definitions were congruent with those applied during model development. In 14 comparisons, the UKPDS, ADVANCE or DCS diabetes-specific models were superior to the general population CVD risk models. Authors reported better C-statistic for models they developed. The limited existing evidence suggests a possible discriminatory advantage of diabetes-specific over general population-based models for CVD risk stratification in diabetes. More robust head-to-head comparisons are needed to confirm this trend and strengthen recommendations. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

  6. The impact of physically demanding work of basketball and volleyball players on the risk for patellar tendinopathy and on work limitations.

    Science.gov (United States)

    van der Worp, H; Zwerver, J; Kuijer, P P F M; Frings-Dresen, M H W; van den Akker-Scheek, I

    2011-01-01

    Patellar tendinopathy is a common injury in jumping athletes. Little is known about work-related etiological factors for patellar tendinopathy and related work limitations. The aim of this study was to identify work-related etiological factors for patellar tendinopathy and to determine the relation between patellar tendinopathy and work limitations. Basketball and volleyball players between 18 and 35 years were invited to complete an online-questionnaire concerning knee complaints, etiological risk factors for patellar tendinopathy and related work limitations. A total of 1505 subjects were included in the analysis. Risk factors for patellar tendinopathy were gender and heavy physically demanding work. The odds for having patellar tendinopathy were significantly higher for heavy physically demanding occupations compared to mentally demanding occupations. 30% of subjects with patellar tendinopathy with a physically demanding job reported to be impaired in their work and 17% reported to be less productive. Basketball and volleyball players with heavy physically demanding work seem to have an increased risk for developing patellar tendinopathy. This finding has important clinical relevance in the treatment of this injury. Working activities should be adjusted in order to reduce the total load on the patellar tendon and help prevention and recovery.

  7. Risk-Based Educational Accountability in Dutch Primary Education

    Science.gov (United States)

    Timmermans, A. C.; de Wolf, I. F.; Bosker, R. J.; Doolaard, S.

    2015-01-01

    A recent development in educational accountability is a risk-based approach, in which intensity and frequency of school inspections vary across schools to make educational accountability more efficient and effective by enabling inspectorates to focus on organizations at risk. Characteristics relevant in predicting which schools are "at risk…

  8. Game Theory and Risk-Based Levee System Design

    Science.gov (United States)

    Hui, R.; Lund, J. R.; Madani, K.

    2014-12-01

    Risk-based analysis has been developed for optimal levee design for economic efficiency. Along many rivers, two levees on opposite riverbanks act as a simple levee system. Being rational and self-interested, land owners on each river bank would tend to independently optimize their levees with risk-based analysis, resulting in a Pareto-inefficient levee system design from the social planner's perspective. Game theory is applied in this study to analyze decision making process in a simple levee system in which the land owners on each river bank develop their design strategies using risk-based economic optimization. For each land owner, the annual expected total cost includes expected annual damage cost and annualized construction cost. The non-cooperative Nash equilibrium is identified and compared to the social planner's optimal distribution of flood risk and damage cost throughout the system which results in the minimum total flood cost for the system. The social planner's optimal solution is not feasible without appropriate level of compensation for the transferred flood risk to guarantee and improve conditions for all parties. Therefore, cooperative game theory is then employed to develop an economically optimal design that can be implemented in practice. By examining the game in the reversible and irreversible decision making modes, the cost of decision making myopia is calculated to underline the significance of considering the externalities and evolution path of dynamic water resource problems for optimal decision making.

  9. Incentivising flood risk adaptation through ris based insurance premiums: trade-offs between affordability and risk reduction

    NARCIS (Netherlands)

    Hudson, P.G.M.B.; Botzen, W.J.W.; Feyen, L.; Aerts, J.C.J.H.

    2016-01-01

    The financial incentives offered by the risk-based pricing of insurance can stimulate policyholder adaptation to flood risk while potentially conflicting with affordability. We examine the trade-off between risk reduction and affordability in a model of public-private flood insurance in France and

  10. Failure detection system risk reduction assessment

    Science.gov (United States)

    Aguilar, Robert B. (Inventor); Huang, Zhaofeng (Inventor)

    2012-01-01

    A process includes determining a probability of a failure mode of a system being analyzed reaching a failure limit as a function of time to failure limit, determining a probability of a mitigation of the failure mode as a function of a time to failure limit, and quantifying a risk reduction based on the probability of the failure mode reaching the failure limit and the probability of the mitigation.

  11. Area-based assessment of extinction risk.

    Science.gov (United States)

    Hei, Fangliang

    2012-05-01

    Underpinning the International Union for Conservation of Nature (IUCN) Red List is the assessment of extinction risk as determined by the size and degree of loss of populations. The IUCN system lists a species as Critically Endangered, Endangered, or Vulnerable if its population size declines 80%, 50%, or 30% within a given time frame. However, effective implementation of the system faces substantial challenges and uncertainty because geographic scale data on population size and long-term dynamics are scarce. I develop a model to quantify extinction risk using a measure based on a species' distribution, a much more readily obtained quantity. The model calculates the loss of the area of occupancy that is equivalent to the loss of a given proportion of a population. It is a very simple yet general model that has no free parameters and is independent of scale. The model predicted well the distributions of 302 tree species at a local scale and the distributions of 348 species of North American land birds. This area-based model provides a solution to the long-standing problem for IUCN assessments of lack of data on population sizes, and thus it will contribute to facilitating the quantification of extinction risk worldwide.

  12. Task-based dermal exposure models for regulatory risk assessment.

    Science.gov (United States)

    Warren, Nicholas D; Marquart, Hans; Christopher, Yvette; Laitinen, Juha; VAN Hemmen, Joop J

    2006-07-01

    The regulatory risk assessment of chemicals requires the estimation of occupational dermal exposure. Until recently, the models used were either based on limited data or were specific to a particular class of chemical or application. The EU project RISKOFDERM has gathered a considerable number of new measurements of dermal exposure together with detailed contextual information. This article describes the development of a set of generic task-based models capable of predicting potential dermal exposure to both solids and liquids in a wide range of situations. To facilitate modelling of the wide variety of dermal exposure situations six separate models were made for groupings of exposure scenarios called Dermal Exposure Operation units (DEO units). These task-based groupings cluster exposure scenarios with regard to the expected routes of dermal exposure and the expected influence of exposure determinants. Within these groupings linear mixed effect models were used to estimate the influence of various exposure determinants and to estimate components of variance. The models predict median potential dermal exposure rates for the hands and the rest of the body from the values of relevant exposure determinants. These rates are expressed as mg or microl product per minute. Using these median potential dermal exposure rates and an accompanying geometric standard deviation allows a range of exposure percentiles to be calculated.

  13. Conceptualization and Pilot Testing of a Core Competency-Based Training Workshop in Suicide Risk Assessment and Management: Notes From the Field.

    Science.gov (United States)

    Cramer, Robert J; Bryson, Claire N; Eichorst, Morgam K; Keyes, Lee N; Ridge, Brittany E

    2017-03-01

    As professional psychology training programs and continuing education have moved toward competency based approaches, it has become equally important to develop uniform, evidence-based approaches for suicide risk assessment and management. The present article presents a workshop curriculum based on established core competencies in suicide risk assessment and management. Drawing on theories suicide risk formation, the workshop features an integration of didactic, process, and experiential components. We present pilot data from 2 small group workshops (n = 17): 1 from a clinical psychology doctoral program and 1 from a university counseling center. Workshop participation yielded increases in (a) the ability to recognize appropriate clinician responses to suicidal client statements, (b) self-perceptions of general capacity to interface with suicidal patients and mastery of the 10 core competencies, (c) factual knowledge concerning suicide risk assessment and management, and (d) the self-rated ability to assess and manage a suicidal patient. We discuss statistical and generalizability limitations as well as implications for future modification, implementation, and provision of this training method. © 2016 Wiley Periodicals, Inc.

  14. Risk-based inservice testing program modifications at Palo Verde nuclear generating station

    International Nuclear Information System (INIS)

    Knauf, S.; Lindenlaub, B.; Linthicum, R.

    1996-01-01

    Arizona Public Service Company (APS) is investigating changes to the Palo Verde Inservice Testing (IST) Program that are intended to result in the reduction of the required test frequency for various valves in the American Society of Mechanical Engineers (ASME) Section XI IST program. The analytical techniques employed to select candidate valves and to demonstrate that these frequency reductions are acceptable are risk based. The results of the Palo Verde probabilistic risk assessment (PRA), updated in June 1994, and the risk significant determination performed as part of the implementation efforts for 10 CFR 50.65 (the maintenance rule) were used to select candidate valves for extended test intervals. Additional component level evaluations were conducted by an 'expert panel.' The decision to pursue these changes was facilitated by the ASME Risk-Based Inservice Testing Research Task Force for which Palo Verde is participating as a pilot plant. The NRC's increasing acceptance of cost beneficial licensing actions and risk-based submittals also provided incentive to seek these changes. Arizona Public Service is pursuing the risk-based IST program modification in order to reduce the unnecessary regulatory burden of the IST program through qualitative and quantitative analysis consistent with maintaining a high level of plant safety. The objectives of this project at Palo Verde are as follows: (1) Apply risk-based technologies to IST components to determine their risk significance (i.e., high or low). (2) Apply a combination of deterministic and risk-based methods to determine appropriate testing requirements for IST components including improvement of testing methods and frequency intervals for high-risk significant components. (3) Apply risk-based technologies to high-risk significant components identified by the open-quotes expert panelclose quotes and outside of the IST program to determine whether additional testing requirements are appropriate

  15. Risk-based inservice testing program modifications at Palo Verde nuclear generating station

    Energy Technology Data Exchange (ETDEWEB)

    Knauf, S.; Lindenlaub, B.; Linthicum, R.

    1996-12-01

    Arizona Public Service Company (APS) is investigating changes to the Palo Verde Inservice Testing (IST) Program that are intended to result in the reduction of the required test frequency for various valves in the American Society of Mechanical Engineers (ASME) Section XI IST program. The analytical techniques employed to select candidate valves and to demonstrate that these frequency reductions are acceptable are risk based. The results of the Palo Verde probabilistic risk assessment (PRA), updated in June 1994, and the risk significant determination performed as part of the implementation efforts for 10 CFR 50.65 (the maintenance rule) were used to select candidate valves for extended test intervals. Additional component level evaluations were conducted by an `expert panel.` The decision to pursue these changes was facilitated by the ASME Risk-Based Inservice Testing Research Task Force for which Palo Verde is participating as a pilot plant. The NRC`s increasing acceptance of cost beneficial licensing actions and risk-based submittals also provided incentive to seek these changes. Arizona Public Service is pursuing the risk-based IST program modification in order to reduce the unnecessary regulatory burden of the IST program through qualitative and quantitative analysis consistent with maintaining a high level of plant safety. The objectives of this project at Palo Verde are as follows: (1) Apply risk-based technologies to IST components to determine their risk significance (i.e., high or low). (2) Apply a combination of deterministic and risk-based methods to determine appropriate testing requirements for IST components including improvement of testing methods and frequency intervals for high-risk significant components. (3) Apply risk-based technologies to high-risk significant components identified by the {open_quotes}expert panel{close_quotes} and outside of the IST program to determine whether additional testing requirements are appropriate.

  16. 75 FR 65881 - Ownership Limitations and Governance Requirements for Security-Based Swap Clearing Agencies...

    Science.gov (United States)

    2010-10-26

    ... it determines they are necessary or appropriate to improve the governance of, or to mitigate systemic... Part IV Securities and Exchange Commission 17 CFR Part 242 Ownership Limitations and Governance... Ownership Limitations and Governance Requirements for Security- Based Swap Clearing Agencies, Security-Based...

  17. Respiratory cancer risks associated with low-level nickel exposure: an integrated assessment based on animal, epidemiological, and mechanistic data.

    Science.gov (United States)

    Seilkop, Steven K; Oller, Adriana R

    2003-04-01

    Increased lung and nasal cancer risks have been reported in several cohorts of nickel refinery workers, but in more than 90% of the nickel-exposed workers that have been studied there is little, if any evidence of excess risk. This investigation utilizes human exposure measurements, animal data from cancer bioassays of three nickel compounds, and a mechanistic theory of nickel carcinogenesis to reconcile the disparities in lung cancer risk among nickel-exposed workers. Animal data and mechanistic theory suggest that the apparent absence of risk in workers with low nickel exposures is due to threshold-like responses in lung tumor incidence (oxidic nickel), tumor promotion (soluble nickel), and genetic damage (sulfidic nickel). When animal-based lung cancer dose-response functions for these compounds are extrapolated to humans, taking into account interspecies differences in deposition and clearance, differences in particle size distributions, and human work activity patterns, the predicted risks at occupational exposures are remarkably similar to those observed in nickel-exposed workers. This provides support for using the animal-based dose-response functions to estimate occupational exposure limits, which are found to be comparable to those in current use.

  18. Risk analyses in nuclear engineerig, their value in terms of information, and their limits in terms of applicability

    International Nuclear Information System (INIS)

    Heuser, F.W.

    1983-01-01

    This contribution first briefly explains the main pillars of the deterministic safety concept as developed in nuclear engineering, and some basic ideas on risk analyses in general. This is followed by an outline of the methodology and main purposes of risk analyses. The German Risk Study is taken as an example to discuss selected aspects with regard to information value and limits of risk analyses. The main conclusions state that risk analyses are a valuable instrument for quantitative safety evaluation, leading to a better understanding of safety problems and their prevention, and allowing a comparative assessment of various safety measures. They furthermore allow a refined evaluation of a variety of accident parameters and other impacts determining the risk emanating from accidents. The current state of the art in this sector still leaves numerous uncertainties so that risk analyses yield information for assessments rather than for definite predictions. However, the urge for quantifying the lack of knowledge leads to a better and more precise determination of the gaps still to be filled up by researchers and engineers. Thus risk analyses are a useful help in defining suitable approaches and setting up standards, showing the tasks to be fulfilled in safety research in general. (orig./HSCH) [de

  19. Development of a risk-based approach to Hanford site cleanup

    International Nuclear Information System (INIS)

    Hesser, W.A.

    1996-01-01

    In response to a request from Mr. Thomas Grumbly, Assistant Secretary of Energy for Environmental Management, the Hanford Site contractors developed a set of risk-based cleanup strategies that (1) protect the public, workers, and environment from unacceptable risks; (2) are executable technically; and (3) fit within currently expected annual funding profiles. These strategies were developed because (1) the U.S. Department of Energy and Hanford Site budgets are being reduced, (2) stakeholders are dissatisfied with the perceived rate of cleanup, (3) the U.S. Congress and the U.S. Department of Energy are increasingly focusing on risk and risk-reduction activities, (4) the present strategy is not integrated across the Site and is inconsistent in its treatment of similar hazards, (5) the present cleanup strategy is not cost-effective from a risk-reduction or future land use perspective, and (6) the milestones and activities in the Tri-Party Agreement cannot be achieved with an anticipated funding of 1.05 billion dollars, or less, annually. This analysis produced a framework and a set of tools that are available for dealing with changes to anticipated funding levels, changes in risk cleanup standards, and Congressional initiatives and inquiries. The tools include land-supply curves, cost profiles, risk profiles, mortgage reduction curves, and minimum operations costs. This paper describes the methodology used to develop mortgage-based, risk-based, and land-based cleanup strategies and how those strategies differ in terms of the work to be performed, its sequence, and the resulting end states

  20. Can an Internet-based health risk assessment highlight problems of heart disease risk factor awareness? A cross-sectional analysis.

    Science.gov (United States)

    Dickerson, Justin B; McNeal, Catherine J; Tsai, Ginger; Rivera, Cathleen M; Smith, Matthew Lee; Ohsfeldt, Robert L; Ory, Marcia G

    2014-04-18

    Health risk assessments are becoming more popular as a tool to conveniently and effectively reach community-dwelling adults who may be at risk for serious chronic conditions such as coronary heart disease (CHD). The use of such instruments to improve adults' risk factor awareness and concordance with clinically measured risk factor values could be an opportunity to advance public health knowledge and build effective interventions. The objective of this study was to determine if an Internet-based health risk assessment can highlight important aspects of agreement between respondents' self-reported and clinically measured CHD risk factors for community-dwelling adults who may be at risk for CHD. Data from an Internet-based cardiovascular health risk assessment (Heart Aware) administered to community-dwelling adults at 127 clinical sites were analyzed. Respondents were recruited through individual hospital marketing campaigns, such as media advertising and print media, found throughout inpatient and outpatient facilities. CHD risk factors from the Framingham Heart Study were examined. Weighted kappa statistics were calculated to measure interrater agreement between respondents' self-reported and clinically measured CHD risk factors. Weighted kappa statistics were then calculated for each sample by strata of overall 10-year CHD risk. Three samples were drawn based on strategies for treating missing data: a listwise deleted sample, a pairwise deleted sample, and a multiple imputation (MI) sample. The MI sample (n=16,879) was most appropriate for addressing missing data. No CHD risk factor had better than marginal interrater agreement (κ>.60). High-density lipoprotein cholesterol (HDL-C) exhibited suboptimal interrater agreement that deteriorated (eg, κInternet-based health risk assessments such as Heart Aware may contribute to public health surveillance, but they must address selection bias of Internet-based recruitment methods.

  1. Risk based decision tool for space exploration missions

    Science.gov (United States)

    Meshkat, Leila; Cornford, Steve; Moran, Terrence

    2003-01-01

    This paper presents an approach and corresponding tool to assess and analyze the risks involved in a mission during the pre-phase A design process. This approach is based on creating a risk template for each subsystem expert involved in the mission design process and defining appropriate interactions between the templates.

  2. Risk stratification in non-ST elevation acute coronary syndromes: Risk scores, biomarkers and clinical judgment

    Directory of Open Access Journals (Sweden)

    David Corcoran

    2015-09-01

    Clinical guidelines recommend an early invasive strategy in higher risk NSTE-ACS. The Global Registry of Acute Coronary Events (GRACE risk score is a validated risk stratification tool which has incremental prognostic value for risk stratification compared with clinical assessment or troponin testing alone. In emergency medicine, there has been a limited adoption of the GRACE score in some countries (e.g. United Kingdom, in part related to a delay in obtaining timely blood biochemistry results. Age makes an exponential contribution to the GRACE score, and on an individual patient basis, the risk of younger patients with a flow-limiting culprit coronary artery lesion may be underestimated. The future incorporation of novel cardiac biomarkers into this diagnostic pathway may allow for earlier treatment stratification. The cost-effectiveness of the new diagnostic pathways based on high-sensitivity troponin and copeptin must also be established. Finally, diagnostic tests and risk scores may optimize patient care but they cannot replace patient-focused good clinical judgment.

  3. Application of risk-based methodologies to prioritize safety resources

    International Nuclear Information System (INIS)

    Rahn, F.J.; Sursock, J.P.; Hosler, J.

    1993-01-01

    The Electric Power Research Institute (EPRI) started a program entitled risk-based prioritization in 1992. The purpose of this program is to provide generic technical support to the nuclear power industry relative to its recent initiatives in the area of operations and maintenance (O ampersand M) cost control using state-of-the-art risk methods. The approach uses probabilistic risk assessment (PRA), or similar techniques, to allocate resources commensurate with the risk posed by nuclear plant operations. Specifically, those items or events that have high risk significance would receive the most attention, while those with little risk content would command fewer resources. As quantified in a companion paper,close-quote the potential O ampersand M cost reduction inherent in this approach is very large. Furthermore, risk-based methods should also lead to safety improvements. This paper outlines the way that the EPRI technical work complements the technical, policy, and regulatory initiatives taken by others in the industry and provides an example of the approach as used to prioritize motor-operated valve (MOV) testing in response to US Nuclear Regulatory Commission (NRC) Generic Letter 89-10

  4. Application of Physiologically Based Pharmacokinetic Models in Chemical Risk Assessment

    Directory of Open Access Journals (Sweden)

    Moiz Mumtaz

    2012-01-01

    Full Text Available Post-exposure risk assessment of chemical and environmental stressors is a public health challenge. Linking exposure to health outcomes is a 4-step process: exposure assessment, hazard identification, dose response assessment, and risk characterization. This process is increasingly adopting “in silico” tools such as physiologically based pharmacokinetic (PBPK models to fine-tune exposure assessments and determine internal doses in target organs/tissues. Many excellent PBPK models have been developed. But most, because of their scientific sophistication, have found limited field application—health assessors rarely use them. Over the years, government agencies, stakeholders/partners, and the scientific community have attempted to use these models or their underlying principles in combination with other practical procedures. During the past two decades, through cooperative agreements and contracts at several research and higher education institutions, ATSDR funded translational research has encouraged the use of various types of models. Such collaborative efforts have led to the development and use of transparent and user-friendly models. The “human PBPK model toolkit” is one such project. While not necessarily state of the art, this toolkit is sufficiently accurate for screening purposes. Highlighted in this paper are some selected examples of environmental and occupational exposure assessments of chemicals and their mixtures.

  5. 12 CFR 652.100 - Audit of the risk-based capital stress test.

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 6 2010-01-01 2010-01-01 false Audit of the risk-based capital stress test... AGRICULTURAL MORTGAGE CORPORATION FUNDING AND FISCAL AFFAIRS Risk-Based Capital Requirements § 652.100 Audit of the risk-based capital stress test. You must have a qualified, independent external auditor review...

  6. Limitations on blanket performance

    International Nuclear Information System (INIS)

    Malang, S.

    1999-01-01

    The limitations on the performance of breeding blankets in a fusion power plant are evaluated. The breeding blankets will be key components of a plant and their limitations with regard to power density, thermal efficiency and lifetime could determine to a large degree the attractiveness of a power plant. The performance of two rather well known blanket concepts under development in the frame of the European Blanket Programme is assessed and their limitations are compared with more advanced (and more speculative) concepts. An important issue is the question of which material (structure, breeder, multiplier, coatings) will limit the performance and what improvement would be possible with a 'better' structural material. This evaluation is based on the premise that the performance of the power plant will be limited by the blankets (including first wall) and not by other components, e.g. divertors, or the plasma itself. However, the justness of this premise remains to be seen. It is shown that the different blanket concepts cover a large range of allowable power densities and achievable thermal efficiencies, and it is concluded that there is a high incentive to go for better performance in spite of possibly higher blanket cost. However, such high performance blankets are usually based on materials and technologies not yet developed and there is a rather high risk that the development could fail. Therefore, it is explained that a part of the development effort should be devoted to concepts where the materials and technologies are more or less in hand in order to ensure that blankets for a DEMO reactor can be developed and tested in a given time frame. (orig.)

  7. Compliance of feed limits, does not mean compliance of food limits

    Directory of Open Access Journals (Sweden)

    van Raamsdonk LWD.

    2009-01-01

    Full Text Available The carry-over of contaminants from feed to animal food products is an important aspect of the animal production chain. For a proper containment, limits for feed as well food products are fixed for a series of chemicals, e.g. dioxins and dioxin-like PCBs, lead, cadmium, some chlorinated pesticides, and aflatoxin B1 (and its metabolite M1 in milk. The relationship between feed and food limits is an important issue. An ideal goal is to assure that compliance to a feed limits automatically results in compliance to food limits. In order to collect information about this relationship, several simulation models and a large database on transfer factors have been developed. An optimal choice between either a model or an application of data from the Transfer Database is based on both the knowledge level, and on the circumstances of the specific situation. To reach and validate such an optimal choice an Expert System Carry-Over is currently in development, containing four different modules: 1 the different calculation models and the Transfer Database, 2 a decision tree for choosing the optimal strategy, 3 data tables indicating knowledge levels of compound/animal/product parameters, and 4 supporting databases containing information on consumption and composition of daily diets, animal parameters, and amounts of (daily production. Calculations indicate that for dioxins compliance to feed levels does not necessarily mean that food limits are complied as well. Besides an estimation of the compliance to limits, the expert system is a tool for feed related risk assessments, and for planning of future research.

  8. Risk assessment of hazardous impacts on urbanization and industrialization activities based upon toxic substances

    Directory of Open Access Journals (Sweden)

    T. Salem

    2016-03-01

    Full Text Available A risk assessment study was conducted to predict the expected hazardous influence on the ecosystem resulted from urbanization and industrialization activities at Helwan area, Egypt. To achieve these goals, soils, plants and water samples were collected from Helwan area, and their total concentrations of inorganic contaminants (Cd, Cr, Co, Cu, Fe, Mn, Ni, Pb, and Zn and organic pollutants; such as Phenol and hydrocarbons were measured. The obtained results showed that, the concentrations of organic contaminants in water streams and surrounding soils recorded high concentration values than the permissible limits, while inorganic elements were within the safe limits for irrigation. In addition, soils irrigated with the effluents of industrial units recorded high values of inorganic and organic contaminants. Consequently, the levels of these contaminants were high in plant tissues grown thereon; especially the edible parts. Risk assessment based on available Predicted No Effect Concentration values for the aquatic and terrestrial environment was performed. Inorganic elements were expected to cause serious hazard problems for both aquatic organisms and soil microorganisms. The impact of these pollutants on human health was calculated using daily metals intake of inorganic metals via consumption of edible plants. Hazard index values proved that concentrations of Cr may cause serious hazard problems for humans in this area; especially, children.

  9. Tailoring Risk Management in Design

    DEFF Research Database (Denmark)

    Tegeltija, M.; Oehmen, J.; McMahon, C. A.

    2018-01-01

    While risk quantification research has grown over the last few decades, only a limited number of studies have addressed the overall process integration of these approaches in design risk management. This paper argues that the choice of risk quantification method has strong implications for several...... process aspects. We investigate current risk management maturity models and suggest an expansion to accommodate requirements originating from the choice of quantification method, and to inform the choice of quantification method, based on other process parameters, validated through 3 case companies....

  10. Risk-based design of process plants with regard to domino effects and land use planning

    Energy Technology Data Exchange (ETDEWEB)

    Khakzad, Nima, E-mail: nkhakzad@gmail.com [Safety and Security Science Group (S3G), Faculty of Technology, Policy and Management, TU Delft, Delft (Netherlands); Reniers, Genserik [Safety and Security Science Group (S3G), Faculty of Technology, Policy and Management, TU Delft, Delft (Netherlands); Antwerp Research Group on Safety and Security (ARGoSS), Faculty of Applied Economics, Universiteit Antwerpen, Antwerp (Belgium); Research Group CEDON, Campus Brussels, KULeuven, Brussels (Belgium)

    2015-12-15

    Highlights: • A Bayesian network methodology has been developed to estimate the total probability of major accidents in chemical plants. • Total probability of accidents includes the probability of individual accidents and potential domino effects. • The methodology has been extended to calculate on-site and off-site risks. • The results of the risk analysis have been used in a multi-criteria decision analysis technique to risk-based design of chemical plants. - Abstract: Land use planning (LUP) as an effective and crucial safety measure has widely been employed by safety experts and decision makers to mitigate off-site risks posed by major accidents. Accordingly, the concept of LUP in chemical plants has traditionally been considered from two perspectives: (i) land developments around existing chemical plants considering potential off-site risks posed by major accidents and (ii) development of existing chemical plants considering nearby land developments and the level of additional off-site risks the land developments would be exposed to. However, the attempts made to design chemical plants with regard to LUP requirements have been few, most of which have neglected the role of domino effects in risk analysis of major accidents. To overcome the limitations of previous work, first, we developed a Bayesian network methodology to calculate both on-site and off-site risks of major accidents while taking domino effects into account. Second, we combined the results of risk analysis with Analytic Hierarchical Process to design an optimal layout for which the levels of on-site and off-site risks would be minimum.

  11. Safety assessment of historical masonry churches based on pre-assigned kinematic limit analysis, FE limit and pushover analyses

    International Nuclear Information System (INIS)

    Milani, Gabriele; Valente, Marco

    2014-01-01

    This study presents some results of a comprehensive numerical analysis on three masonry churches damaged by the recent Emilia-Romagna (Italy) seismic events occurred in May 2012. The numerical study comprises: (a) pushover analyses conducted with a commercial code, standard nonlinear material models and two different horizontal load distributions; (b) FE kinematic limit analyses performed using a non-commercial software based on a preliminary homogenization of the masonry materials and a subsequent limit analysis with triangular elements and interfaces; (c) kinematic limit analyses conducted in agreement with the Italian code and based on the a-priori assumption of preassigned failure mechanisms, where the masonry material is considered unable to withstand tensile stresses. All models are capable of giving information on the active failure mechanism and the base shear at failure, which, if properly made non-dimensional with the weight of the structure, gives also an indication of the horizontal peak ground acceleration causing the collapse of the church. The results obtained from all three models indicate that the collapse is usually due to the activation of partial mechanisms (apse, façade, lateral walls, etc.). Moreover the horizontal peak ground acceleration associated to the collapse is largely lower than that required in that seismic zone by the Italian code for ordinary buildings. These outcomes highlight that structural upgrading interventions would be extremely beneficial for the considerable reduction of the seismic vulnerability of such kind of historical structures

  12. Safety assessment of historical masonry churches based on pre-assigned kinematic limit analysis, FE limit and pushover analyses

    Energy Technology Data Exchange (ETDEWEB)

    Milani, Gabriele, E-mail: milani@stru.polimi.it; Valente, Marco, E-mail: milani@stru.polimi.it [Department of Architecture, Built Environment and Construction Engineering (ABC), Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milan (Italy)

    2014-10-06

    This study presents some results of a comprehensive numerical analysis on three masonry churches damaged by the recent Emilia-Romagna (Italy) seismic events occurred in May 2012. The numerical study comprises: (a) pushover analyses conducted with a commercial code, standard nonlinear material models and two different horizontal load distributions; (b) FE kinematic limit analyses performed using a non-commercial software based on a preliminary homogenization of the masonry materials and a subsequent limit analysis with triangular elements and interfaces; (c) kinematic limit analyses conducted in agreement with the Italian code and based on the a-priori assumption of preassigned failure mechanisms, where the masonry material is considered unable to withstand tensile stresses. All models are capable of giving information on the active failure mechanism and the base shear at failure, which, if properly made non-dimensional with the weight of the structure, gives also an indication of the horizontal peak ground acceleration causing the collapse of the church. The results obtained from all three models indicate that the collapse is usually due to the activation of partial mechanisms (apse, façade, lateral walls, etc.). Moreover the horizontal peak ground acceleration associated to the collapse is largely lower than that required in that seismic zone by the Italian code for ordinary buildings. These outcomes highlight that structural upgrading interventions would be extremely beneficial for the considerable reduction of the seismic vulnerability of such kind of historical structures.

  13. A proposed risk acceptance criterion for nuclear fuel waste disposal

    International Nuclear Information System (INIS)

    Mehta, K.

    1985-06-01

    The need to establish a radiological protection criterion that applies specifically to disposal of high level nuclear fuel wastes arises from the difficulty of applying the present ICRP recommendations. These recommendations apply to situations in which radiological detriment can be actively controlled, while a permanent waste disposal facility is meant to operate without the need for corrective actions. Also, the risks associated with waste disposal depend on events and processes that have various probabilities of occurrence. In these circumstances, it is not suitable to apply standards that are based on a single dose limit as in the present ICRP recommendations, because it will generally be possible to envisage events, perhaps rare, that would lead to doses above any selected limit. To overcome these difficulties, it is proposed to base a criterion for acceptability on a set of dose values and corresponding limiting values of probabilities; this set of values constitutes a risk-limit line. A risk-limit line suitable for waste disposal is proposed that has characteristics consistent with the basic philosophy of the ICRP and UNSCEAR recommendations, and is based on levels on natural background radiation

  14. Habitat selection and risk of predation: re-colonization by lynx had limited impact on habitat selection by roe deer.

    Directory of Open Access Journals (Sweden)

    Gustaf Samelius

    Full Text Available Risk of predation is an evolutionary force that affects behaviors of virtually all animals. In this study, we examined how habitat selection by roe deer was affected by risk of predation by Eurasian lynx - the main predator of roe deer in Scandinavia. Specifically, we compared how habitat selection by roe deer varied (1 before and after lynx re-established in the study area and (2 in relation to habitat-specific risk of predation by lynx. All analyses were conducted at the spatial and temporal scales of home ranges and seasons. We did not find any evidence that roe deer avoided habitats in which the risk of predation by lynx was greatest and information-theoretic model selection showed that re-colonization by lynx had limited impact on habitat selection by roe deer despite lynx predation causing 65% of known mortalities after lynx re-colonized the area. Instead we found that habitat selection decreased when habitat availability increased for 2 of 5 habitat types (a pattern referred to as functional response in habitat selection. Limited impact of re-colonization by lynx on habitat selection by roe deer in this study differs from elk in North America altering both daily and seasonal patterns in habitat selection at the spatial scales of habitat patches and home ranges when wolves were reintroduced to Yellowstone National Park. Our study thus provides further evidence of the complexity by which animals respond to risk of predation and suggest that it may vary between ecosystems and predator-prey constellations.

  15. Habitat selection and risk of predation: re-colonization by lynx had limited impact on habitat selection by roe deer.

    Science.gov (United States)

    Samelius, Gustaf; Andrén, Henrik; Kjellander, Petter; Liberg, Olof

    2013-01-01

    Risk of predation is an evolutionary force that affects behaviors of virtually all animals. In this study, we examined how habitat selection by roe deer was affected by risk of predation by Eurasian lynx - the main predator of roe deer in Scandinavia. Specifically, we compared how habitat selection by roe deer varied (1) before and after lynx re-established in the study area and (2) in relation to habitat-specific risk of predation by lynx. All analyses were conducted at the spatial and temporal scales of home ranges and seasons. We did not find any evidence that roe deer avoided habitats in which the risk of predation by lynx was greatest and information-theoretic model selection showed that re-colonization by lynx had limited impact on habitat selection by roe deer despite lynx predation causing 65% of known mortalities after lynx re-colonized the area. Instead we found that habitat selection decreased when habitat availability increased for 2 of 5 habitat types (a pattern referred to as functional response in habitat selection). Limited impact of re-colonization by lynx on habitat selection by roe deer in this study differs from elk in North America altering both daily and seasonal patterns in habitat selection at the spatial scales of habitat patches and home ranges when wolves were reintroduced to Yellowstone National Park. Our study thus provides further evidence of the complexity by which animals respond to risk of predation and suggest that it may vary between ecosystems and predator-prey constellations.

  16. Guidelines for Risk-Based Changeover of Biopharma Multi-Product Facilities.

    Science.gov (United States)

    Lynch, Rob; Barabani, David; Bellorado, Kathy; Canisius, Peter; Heathcote, Doug; Johnson, Alan; Wyman, Ned; Parry, Derek Willison

    2018-01-01

    In multi-product biopharma facilities, the protection from product contamination due to the manufacture of multiple products simultaneously is paramount to assure product quality. To that end, the use of traditional changeover methods (elastomer change-out, full sampling, etc.) have been widely used within the industry and have been accepted by regulatory agencies. However, with the endorsement of Quality Risk Management (1), the use of risk-based approaches may be applied to assess and continuously improve established changeover processes. All processes, including changeover, can be improved with investment (money/resources), parallel activities, equipment design improvements, and standardization. However, processes can also be improved by eliminating waste. For product changeover, waste is any activity not needed for the new process or that does not provide added assurance of the quality of the subsequent product. The application of a risk-based approach to changeover aligns with the principles of Quality Risk Management. Through the use of risk assessments, the appropriate changeover controls can be identified and controlled to assure product quality is maintained. Likewise, the use of risk assessments and risk-based approaches may be used to improve operational efficiency, reduce waste, and permit concurrent manufacturing of products. © PDA, Inc. 2018.

  17. Outlier treatment for improving parameter estimation of group contribution based models for upper flammability limit

    DEFF Research Database (Denmark)

    Frutiger, Jerome; Abildskov, Jens; Sin, Gürkan

    2015-01-01

    Flammability data is needed to assess the risk of fire and explosions. This study presents a new group contribution (GC) model to predict the upper flammability limit UFL oforganic chemicals. Furthermore, it provides a systematic method for outlier treatment inorder to improve the parameter...

  18. Strengthening air traffic safety management by moving from outcome-based towards risk-based evaluation of runway incursions

    International Nuclear Information System (INIS)

    Stroeve, Sybert H.; Som, Pradip; Doorn, Bas A. van; Bakker, G.J.

    2016-01-01

    Current safety management of aerodrome operations uses judgements of severity categories to evaluate runway incursions. Incident data show a small minority of severe incursions and a large majority of less severe incursions. We show that these severity judgements are mainly based upon the outcomes of runway incursions, in particular on the closest distances attained. As such, the severity-based evaluation leads to coincidental safety management feedback, wherein causes and risk implications of runway incursions are not well considered. In this paper we present a new framework for the evaluation of runway incursions, which effectively uses all runway incursions, which judges same types of causes similarly, and which structures causes and risk implications. The framework is based on risks of scenarios associated with the initiation of runway incursions. As a basis an inventory of scenarios is provided, which can represent almost all runway incursions involving a conflict with an aircraft. A main step in the framework is the assessment of the conditional probability of a collision given a runway incursion scenario. This can be effectively achieved for large sets of scenarios by agent-based dynamic risk modelling. The results provide detailed feedback on risks of runway incursion scenarios, thus enabling effective safety management. - Highlights: • Current evaluation of runway incursions is primarily based on their outcomes. • A new framework assesses collision risk given initiation of runway incursions. • Agent-based dynamic risk modelling can evaluate the risks of many scenarios. • A developed scenario inventory can represent almost all runway incursions. • The framework provides detailed feedback to safety management.

  19. Health-Based Capitation Risk Adjustment in Minnesota Public Health Care Programs

    Science.gov (United States)

    Gifford, Gregory A.; Edwards, Kevan R.; Knutson, David J.

    2004-01-01

    This article documents the history and implementation of health-based capitation risk adjustment in Minnesota public health care programs, and identifies key implementation issues. Capitation payments in these programs are risk adjusted using an historical, health plan risk score, based on concurrent risk assessment. Phased implementation of capitation risk adjustment for these programs began January 1, 2000. Minnesota's experience with capitation risk adjustment suggests that: (1) implementation can accelerate encounter data submission, (2) administrative decisions made during implementation can create issues that impact payment model performance, and (3) changes in diagnosis data management during implementation may require changes to the payment model. PMID:25372356

  20. Likelihood ratio-based integrated personal risk assessment of type 2 diabetes.

    Science.gov (United States)

    Sato, Noriko; Htun, Nay Chi; Daimon, Makoto; Tamiya, Gen; Kato, Takeo; Kubota, Isao; Ueno, Yoshiyuki; Yamashita, Hidetoshi; Fukao, Akira; Kayama, Takamasa; Muramatsu, Masaaki

    2014-01-01

    To facilitate personalized health care for multifactorial diseases, risks of genetic and clinical/environmental factors should be assessed together for each individual in an integrated fashion. This approach is possible with the likelihood ratio (LR)-based risk assessment system, as this system can incorporate manifold tests. We examined the usefulness of this system for assessing type 2 diabetes (T2D). Our system employed 29 genetic susceptibility variants, body mass index (BMI), and hypertension as risk factors whose LRs can be estimated from openly available T2D association data for the Japanese population. The pretest probability was set at a sex- and age-appropriate population average of diabetes prevalence. The classification performance of our LR-based risk assessment was compared to that of a non-invasive screening test for diabetes called TOPICS (with score based on age, sex, family history, smoking, BMI, and hypertension) using receiver operating characteristic analysis with a community cohort (n = 1263). The area under the receiver operating characteristic curve (AUC) for the LR-based assessment and TOPICS was 0.707 (95% CI 0.665-0.750) and 0.719 (0.675-0.762), respectively. These AUCs were much higher than that of a genetic risk score constructed using the same genetic susceptibility variants, 0.624 (0.574-0.674). The use of ethnically matched LRs is necessary for proper personal risk assessment. In conclusion, although LR-based integrated risk assessment for T2D still requires additional tests that evaluate other factors, such as risks involved in missing heritability, our results indicate the potential usability of LR-based assessment system and stress the importance of stratified epidemiological investigations in personalized medicine.

  1. Contradictions Between Risk Management and Sustainable Development

    International Nuclear Information System (INIS)

    Olsen, Odd Einar; Langhelle, Oluf; Engen, Ole A.

    2006-01-01

    The aim of this paper is to discuss how risk management as a methodology and mindset influence on priorities and decisions concerning sustainable development. Management of risks and hazards often rely on partial analysis with a limited time frame. This may lead to a paradoxical situation where risk management and extended use of risk analysis could hamper long term sustainable development. The question is: Does the use of risk and vulnerability analysis (RaV-analysis) hamper or contribute to sustainable development? Because risk management and assessment has a more narrow scope and a limited time perspective based on well established methodologies, the tangible impacts of risk reducing measures in a project is easier to calculate than long-term and intangible impacts on global development. Empirical evidence is still scarce, but our preliminary conclusion is that mainstream risk management and assessments is counterproductive to sustainable development

  2. Contradictions Between Risk Management and Sustainable Development

    Energy Technology Data Exchange (ETDEWEB)

    Olsen, Odd Einar; Langhelle, Oluf; Engen, Ole A. [Univ. of Stavanger (Norway). Dept. of Media, Culture and Social Science

    2006-09-15

    The aim of this paper is to discuss how risk management as a methodology and mindset influence on priorities and decisions concerning sustainable development. Management of risks and hazards often rely on partial analysis with a limited time frame. This may lead to a paradoxical situation where risk management and extended use of risk analysis could hamper long term sustainable development. The question is: Does the use of risk and vulnerability analysis (RaV-analysis) hamper or contribute to sustainable development? Because risk management and assessment has a more narrow scope and a limited time perspective based on well established methodologies, the tangible impacts of risk reducing measures in a project is easier to calculate than long-term and intangible impacts on global development. Empirical evidence is still scarce, but our preliminary conclusion is that mainstream risk management and assessments is counterproductive to sustainable development.

  3. 12 CFR 956.4 - Risk-based capital requirement for investments.

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 7 2010-01-01 2010-01-01 false Risk-based capital requirement for investments... OFF-BALANCE SHEET ITEMS FEDERAL HOME LOAN BANK INVESTMENTS § 956.4 Risk-based capital requirement for investments. Each Bank shall hold retained earnings plus general allowance for losses as support for the...

  4. An In Silico Approach for Evaluating a Fraction-Based, Risk Assessment Method for Total Petroleum Hydrocarbon Mixtures

    Directory of Open Access Journals (Sweden)

    Nina Ching Y. Wang

    2012-01-01

    Full Text Available Both the Massachusetts Department of Environmental Protection (MADEP and the Total Petroleum Hydrocarbon Criteria Working Group (TPHCWG developed fraction-based approaches for assessing human health risks posed by total petroleum hydrocarbon (TPH mixtures in the environment. Both organizations defined TPH fractions based on their expected environmental fate and by analytical chemical methods. They derived toxicity values for selected compounds within each fraction and used these as surrogates to assess hazard or risk of exposure to the whole fractions. Membership in a TPH fraction is generally defined by the number of carbon atoms in a compound and by a compound's equivalent carbon (EC number index, which can predict its environmental fate. Here, we systematically and objectively re-evaluate the assignment of TPH to specific fractions using comparative molecular field analysis and hierarchical clustering. The approach is transparent and reproducible, reducing inherent reliance on judgment when toxicity information is limited. Our evaluation of membership in these fractions is highly consistent (̃80% on average across various fractions with the empirical approach of MADEP and TPHCWG. Furthermore, the results support the general methodology of mixture risk assessment to assess both cancer and noncancer risk values after the application of fractionation.

  5. Administrative limits for tritium concentrations found in non-potable groundwater at nuclear power facilities

    International Nuclear Information System (INIS)

    Parker, R.; Hart, D.; WIllert, C.

    2012-01-01

    Currently, there is a regulatory limit available for tritium in drinking water, but no such limit for non-potable groundwater. Voluntary administrative limits for site groundwater may be established at nuclear power facilities to ensure minimal risk to human health and the environment, and provide guidance for investigation or other actions intended to prevent exceedances of future regulatory or guideline limits. This work presents a streamlined approach for nuclear power facilities to develop three tiers of administrative limits for tritium in groundwater so that facilities can identify abnormal/uncontrolled releases of tritium at an early stage, and take appropriate actions to investigate, control, and protect groundwater. Tier 1 represents an upper limit of background, Tier 2 represents a level between background and Tier 3, and Tier 3 represents a risk-based concentration protective of down-gradient receptors. (author)

  6. 12 CFR 955.6 - Risk-based capital requirement for acquired member assets.

    Science.gov (United States)

    2010-01-01

    ... losses as support for the credit risk of all AMA estimated by the Bank to represent a credit risk that is...) Recalculation of credit enhancement. For risk-based capital purposes, each Bank shall recalculate the estimated... 12 Banks and Banking 7 2010-01-01 2010-01-01 false Risk-based capital requirement for acquired...

  7. Assessing surface water flood risk and management strategies under future climate change: Insights from an Agent-Based Model.

    Science.gov (United States)

    Jenkins, K; Surminski, S; Hall, J; Crick, F

    2017-10-01

    Climate change and increasing urbanization are projected to result in an increase in surface water flooding and consequential damages in the future. In this paper, we present insights from a novel Agent Based Model (ABM), applied to a London case study of surface water flood risk, designed to assess the interplay between different adaptation options; how risk reduction could be achieved by homeowners and government; and the role of flood insurance and the new flood insurance pool, Flood Re, in the context of climate change. The analysis highlights that while combined investment in property-level flood protection and sustainable urban drainage systems reduce surface water flood risk, the benefits can be outweighed by continued development in high risk areas and the effects of climate change. In our simulations, Flood Re is beneficial in its function to provide affordable insurance, even under climate change. However, the scheme does face increasing financial pressure due to rising surface water flood damages. If the intended transition to risk-based pricing is to take place then a determined and coordinated strategy will be needed to manage flood risk, which utilises insurance incentives, limits new development, and supports resilience measures. Our modelling approach and findings are highly relevant for the ongoing regulatory and political approval process for Flood Re as well as for wider discussions on the potential of insurance schemes to incentivise flood risk management and climate adaptation in the UK and internationally. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. A simple data base for identification of risk profiles

    Energy Technology Data Exchange (ETDEWEB)

    Munganahalli, D.

    1996-12-31

    Sedco Forex is a drilling contractor that operates approximately 80 rigs on land and offshore worldwide. The HSE management system developed by Sedco Forex is an effort to prevent accidents and minimize losses. An integral part of the HSE management system is establishing risk profiles and thereby minimizing risk and reducing loss exposures. Risk profiles are established based on accident reports, potential accident reports and other risk identification reports (RIR) like the Du Pont STOP system. A rig could fill in as many as 30 accident reports, 30 potential accident reports and 500 STOP cards each year. Statistics are important for an HSE management system, since they are indicators of success or failure of HSE systems. It is however difficult to establish risk profiles based on statistical information, unless tools are available at the rig site to aid with the analysis. Risk profiles are then used to identify important areas in the operation that may require specific attention to minimize the loss exposure. Programs to address the loss exposure can then be identified and implemented with either a local or corporate approach. In January 1995, Sedco Forex implemented a uniform HSE Database on all the rigs worldwide. In one year companywide, the HSE database would contain information on approximately 500 accident and potential accident reports, and 10,000 STOP cards. This paper demonstrates the salient features of the database and describes how it has helped in establishing key risk profiles. It also shows a recent example of how risk profiles have been established at the corporate level and used to identify the key contributing factors to hands and finger injuries. Based on this information, a campaign was launched to minimize the frequency of occurrence and associated loss attributed to hands and fingers accidents.

  9. Enterprise risk management implementation : perceptions of risk practitioners in the South African mining industry

    OpenAIRE

    2013-01-01

    M.Comm. (Financial Economics) Enterprise risk management (ERM) is emerging as a risk management methodology that is seemingly superior to that of traditional, silo-based risk management. Although ERM implementation is on the increase, research into ERM is still limited. There is, for instance, a lack of clarity within the literature regarding which factors lead to companies embracing ERM, as well as a lack of consensus on ERM’s benefits. The purpose of this study was therefore to explore t...

  10. Experiences with strain based limit state design in The Netherlands

    NARCIS (Netherlands)

    Gresnigt, A.M.; Foeken, R.J. van

    1996-01-01

    Limit state design differs from conventional design methods in that each failure mode is specifically addressed (e.g. burst, collapse, local buckling, fracture due to insufficient strain capacity of the pipe wall, fatigue). Based on an extensive theoretical and experimental research programme,

  11. AHP-based risk analysis of energy performance contracting projects in Russia

    International Nuclear Information System (INIS)

    Garbuzova-Schlifter, Maria; Madlener, Reinhard

    2016-01-01

    Understanding and properly managing risks that could potentially affect the target- and performance-based profits of energy performance contracting (EPC) projects are essential. It is particularly important for the establishment and success of energy service companies (ESCOs) acting in the vulnerable environment of the vast but highly energy-inefficient Russian market. This study systematically explores common risk factors and causes of risk associated with EPC projects executed in three Russian sectors: (1) industrial; (2) housing and communal services; and (3) public. Several interviews with the Russian EPC experts were accomplished and a qualitative risk assessment by using an analytic hierarchy process (AHP) approach. The data were obtained from a web-based questionnaire survey conducted among Russian EPC project executors. For each focus sector, a specific preference-based ranking of the identified risk factors and causes of risk was derived. The AHP results show that causes of risk related to the financial and regulatory aspects contribute most to the riskiness of EPC projects performed in all three focus sectors in Russia, calling for the special attention of EPC policy- and business-makers. Due to sectorial particularities and different actors involved, we conclude that there is a need for elaboration of sector-specific contractual schemes for EPC projects. - Highlights: • AHP- and survey-based study of energy performance contracting (EPC) projects in Russia. • Main risk factors and causes of risk associated with EPC projects are investigated. • In practice, lack of a feasible risk management approach in EPC projects. • Regulatory and financial risks contribute most to the EPC projects’ riskiness. • Elaboration of the sector-specific EPC project contractual scheme is required.

  12. A performance-oriented and risk-based regulation for containment testing

    International Nuclear Information System (INIS)

    Dey, M.

    1994-01-01

    In August 1992, the NRC initiated a major initiative to develop requirements for containment testing that are less prescriptive, and more performance-oriented and risk-based. This action was a result of public comments and several studies that concluded that the economic burden of certain, present containment testing requirements are not commensurate with their safety benefits. The rulemaking will include consideration of relaxing the allowable containment leakage rate, increasing the interval for the integrated containment test, and establishing intervals for the local containment leak rate tests based on their performance. A study has been conducted to provide technical information for establishing the performance criteria for containment tests, the allowable leakage rate, commensurate with its significance to total public risk. The study used results of a recent comprehensive study conducted by the NRC, NUREG-1150, 'Severe Accident Risks: An Assessment for Five U.S. Nuclear Power Plants,' to examine the sensitivity of containment leakage to public risk. Risk was found to be insensitive to containment leakage rate up to levels of about 100 percent-volume per day for certain types of containments. PRA methods have also been developed to establish risk-based intervals for containment tests based on their past experience. Preliminary evaluations show that increasing the interval for the integrated containment leakage test from three times to once every ten years would have an insignificant impact on public risk. Preliminary analyses of operational experience data for local leak rate tests show that performance-based testing, valves and penetrations that perform well are tested less frequently, is feasible with marginal impact on safety. The above technical studies are being used to develop efficient (cost-effective) requirements for containment tests. (author). 4 refs., 2 figs

  13. Genetic variation in the base excision repair pathway, environmental risk factors, and colorectal adenoma risk.

    Directory of Open Access Journals (Sweden)

    Roman Corral

    Full Text Available Cigarette smoking, high alcohol intake, and low dietary folate levels are risk factors for colorectal adenomas. Oxidative damage caused by these three factors can be repaired through the base excision repair pathway (BER. We hypothesized that genetic variation in BER might modify colorectal adenoma risk. In a sigmoidoscopy-based study, we examined associations between 182 haplotype tagging SNPs in 14 BER genes, and colorectal adenoma risk, and examined their potential role as modifiers of the effect cigarette smoking, alcohol intake, and dietary folate levels. Among all individuals, no statistically significant associations between BER SNPs and adenoma risk persisted after correction for multiple comparisons. However, among Asian-Pacific Islanders we observed two SNPs in FEN1 and one in NTHL1, and among African-Americans one SNP in APEX1 that were associated with colorectal adenoma risk. Significant associations were also observed between SNPs in the NEIL2 gene and rectal adenoma risk. Three SNPS modified the effect of smoking (MUTYH interaction p = 0.002; OGG1 interaction p = 0.013; FEN1 interaction p = 0.013, one SNP in LIG3 modified the effect of alcohol consumption (interaction p = 0.024 and two SNPs in LIG3 modified the effect of dietary folate (interaction p = 0.001 and p = 0.08 on colorectal adenoma risk. These findings support a role for genetic variants in the BER pathway as potential modifiers of colorectal adenoma risk. Our findings strengthen the role of oxidative damage induced by key lifestyle and dietary risk factors in colorectal adenoma formation.

  14. Limitation of radioactive discharges from NPP based on radionuclide specific monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Bucina, I; Malatova, I; Vidlakova, J [National Radaition Protection Institute, Prague (Czech Republic)

    1996-12-31

    Monitoring of nuclear power plants (NPP) discharges into atmosphere and hydrosphere based on particulate-iodine-gas (PIG) measurements and gross beta and gamma plus tritium measurements respectively is being improved by nuclide specific measurements employing semiconductor gamma and alpha spectrometry and radiochemical methods. In connection with the progress new concept of authorized effluent limits and the related regulations is being implemented in the Czech Republic. Activities of all principally contributing to the effective dose radionuclides discharges during a year multiplied by a Sv/Bq conversion coefficient based on a standard model are summed up and the effective dose is compared with the new limit. These limits should be authorized for discharges into atmosphere as per caput collective committed effective dose in the NPP surrounding or as its value multiplied by the number of surrounding segment providing thus committed effective dose to member of a vital critical group and into the hydrosphere as committed effective dose to the critical group member. The criteria for obligatory evaluation of the specific radionuclide contribution and the resulting requirements on minimum detectable activities for both the shorter and longer monitoring intervals are included in the new regulations. The PIG and gross activity measurement results will be compared with investigation levels only and no more used for limitation purposes. (authors).

  15. Burden of typhoid fever in low-income and middle-income countries: a systematic, literature-based update with risk-factor adjustment.

    Science.gov (United States)

    Mogasale, Vittal; Maskery, Brian; Ochiai, R Leon; Lee, Jung Seok; Mogasale, Vijayalaxmi V; Ramani, Enusa; Kim, Young Eun; Park, Jin Kyung; Wierzba, Thomas F

    2014-10-01

    No access to safe water is an important risk factor for typhoid fever, yet risk-level heterogeneity is unaccounted for in previous global burden estimates. Since WHO has recommended risk-based use of typhoid polysaccharide vaccine, we revisited the burden of typhoid fever in low-income and middle-income countries (LMICs) after adjusting for water-related risk. We estimated the typhoid disease burden from studies done in LMICs based on blood-culture-confirmed incidence rates applied to the 2010 population, after correcting for operational issues related to surveillance, limitations of diagnostic tests, and water-related risk. We derived incidence estimates, correction factors, and mortality estimates from systematic literature reviews. We did scenario analyses for risk factors, diagnostic sensitivity, and case fatality rates, accounting for the uncertainty in these estimates and we compared them with previous disease burden estimates. The estimated number of typhoid fever cases in LMICs in 2010 after adjusting for water-related risk was 11·9 million (95% CI 9·9-14·7) cases with 129 000 (75 000-208 000) deaths. By comparison, the estimated risk-unadjusted burden was 20·6 million (17·5-24·2) cases and 223 000 (131 000-344 000) deaths. Scenario analyses indicated that the risk-factor adjustment and updated diagnostic test correction factor derived from systematic literature reviews were the drivers of differences between the current estimate and past estimates. The risk-adjusted typhoid fever burden estimate was more conservative than previous estimates. However, by distinguishing the risk differences, it will allow assessment of the effect at the population level and will facilitate cost-effectiveness calculations for risk-based vaccination strategies for future typhoid conjugate vaccine. Copyright © 2014 Mogasale et al. Open Access article distributed under the terms of CC BY-NC-SA. Published by .. All rights reserved.

  16. The effect of Pilates based exercise on mobility, postural stability, and balance in order to decrease fall risk in older adults.

    Science.gov (United States)

    Pata, Rachel W; Lord, Katrina; Lamb, Jamie

    2014-07-01

    Falls are a common problem in older adults. Impaired balance, mobility and postural stability are risk factors for falling. Limited research has been performed on Pilates exercise and the ability to decrease fall risk. In this quasi-experimental study, 35 adults (61-87 years old) participated in an 8-week Pilates based exercise program. Blind examiners conducted the Timed Up and Go (TUG), Forward Reach Test, and Turn 180 Test before and after the intervention. Number of falls, perception of Pilates, and fear of falling was also recorded. Thirty-two (91.4%) participants completed post-test measures. Significant improvements were seen in the TUG (p falling was shown. Results suggest a Pilates based exercise program may be effective in improving balance, mobility and postural stability to decrease fall risk. Copyright © 2013 Elsevier Ltd. All rights reserved.

  17. A qualitative analysis of peer recruitment pressures in respondent driven sampling: Are risks above the ethical limit?

    Science.gov (United States)

    Mosher, Heather I; Moorthi, Gayatri; Li, JiangHong; Weeks, Margaret R

    2015-09-01

    This paper examines peer recruitment dynamics through respondent driven sampling (RDS) with a sample of injection drug users in Hartford, CT to understand the strategies participants use to recruit peers into a study and the extent to which these strategies may introduce risks above the ethical limit despite safeguards in RDS. Out of 526 injection drug users who participated in a mixed-method RDS methodology evaluation study, a nested sample of 61 participants completed an in-depth semi-structured interview at a 2-month follow-up to explore their experiences with the recruitment process. Findings revealed that participants used a variety of strategies to recruit peers, ranging from one-time interactions to more persistent strategies to encourage participation (e.g., selecting peers that can easily be found and contacted later, following up with peers to remind them of their appointment, accompanying peers to the study site, etc.). Some participants described the more persistent strategies as helpful, while some others experienced these strategies as minor peer pressure, creating a feeling of obligation to participate. Narratives revealed that overall, the probability of experiencing study-related risks remains relatively low for most participants; however, a disconcerting finding was that higher study-related risks (e.g., relationship conflict, loss of relationship, physical fights, violence) were seen for recruits who participated but switched coupons or for recruits who decided not to participate in the study and did not return the coupon to the recruiter. Findings indicate that peer recruitment practices in RDS generally pose minimal risk, but that peer recruitment may occasionally exceed the ethical limit, and that enhanced safeguards for studies using peer recruitment methods are recommended. Suggestions for possible enhancements are described. Copyright © 2015 Elsevier B.V. All rights reserved.

  18. Competing-Risks Mortality After Radiotherapy vs. Observation for Localized Prostate Cancer: A Population-based Study

    Energy Technology Data Exchange (ETDEWEB)

    Abdollah, Firas, E-mail: firas.abdollah@gmail.com [Cancer Prognostics and Health Outcomes Unit, University of Montreal Health Centre, Montreal (Canada); Department of Urology, Vita Salute San Raffaele University, Milan (Italy); Sun, Maxine [Cancer Prognostics and Health Outcomes Unit, University of Montreal Health Centre, Montreal (Canada); Schmitges, Jan [Cancer Prognostics and Health Outcomes Unit, University of Montreal Health Centre, Montreal (Canada); Martini-Clinic, Prostate Cancer Center Hamburg-Eppendorf, Hamburg (Germany); Thuret, Rodolphe [Cancer Prognostics and Health Outcomes Unit, University of Montreal Health Centre, Montreal (Canada); Department of Urology, University of Montpellier Health Centre, Montpellier (France); Tian, Zhe [Cancer Prognostics and Health Outcomes Unit, University of Montreal Health Centre, Montreal (Canada); Shariat, Shahrokh F. [Department of Urology, Weill Medical College of Cornell University, New York, NY (United States); Briganti, Alberto [Department of Urology, Vita Salute San Raffaele University, Milan (Italy); Jeldres, Claudio; Perrotte, Paul [Cancer Prognostics and Health Outcomes Unit, University of Montreal Health Centre, Montreal (Canada); Department of Urology, University of Montreal Health Centre, Montreal (Canada); Montorsi, Francesco [Department of Urology, Vita Salute San Raffaele University, Milan (Italy); Karakiewicz, Pierre I. [Cancer Prognostics and Health Outcomes Unit, University of Montreal Health Centre, Montreal (Canada); Department of Urology, University of Montreal Health Centre, Montreal (Canada)

    2012-09-01

    Purpose: Contemporary patients with localized prostate cancer (PCa) are more frequently treated with radiotherapy. However, there are limited data on the effect of this treatment on cancer-specific mortality (CSM). Our objective was to test the relationship between radiotherapy and survival in men with localized PCa and compare it with those treated with observation. Methods: A population-based cohort identified 68,797 men with cT1-T2 PCa treated with radiotherapy or observation between the years 1992 and 2005. Propensity-score matching was used to minimize potential bias related to treatment assignment. Competing-risks analyses tested the effect of treatment type (radiotherapy vs. observation) on CSM, after accounting to other-cause mortality. All analyses were carried out within PCa risk, baseline comorbidity status, and age groups. Results: Radiotherapy was associated with more favorable 10-year CSM rates than observation in patients with high-risk PCa (8.8 vs. 14.4%, hazard ratio [HR]: 0.59, 95% confidence interval [CI]: 0.50-0.68). Conversely, the beneficial effect of radiotherapy on CSM was not evident in patients with low-intermediate risk PCa (3.7 vs. 4.1%, HR: 0.91, 95% CI: 0.80-1.04). Radiotherapy was beneficial in elderly patients (5.6 vs. 7.3%, HR: 0.70, 95% CI: 0.59-0.80). Moreover, it was associated with improved CSM rates among patients with no comorbidities (5.7 vs. 6.5%, HR: 0.81, 95% CI: 0.67-0.98), one comorbidity (4.6 vs. 6.0%, HR: 0.87, 95% CI: 0.75-0.99), and more than two comorbidities (4.2 vs. 5.0%, HR: 0.79, 95% CI: 0.65-0.96). Conclusions: Radiotherapy substantially improves CSM in patients with high-risk PCa, with little or no benefit in patients with low-/intermediate-risk PCa relative to observation. These findings must be interpreted within the context of the limitations of observational data.

  19. An Agent-Based Model of Evolving Community Flood Risk.

    Science.gov (United States)

    Tonn, Gina L; Guikema, Seth D

    2017-11-17

    Although individual behavior plays a major role in community flood risk, traditional flood risk models generally do not capture information on how community policies and individual decisions impact the evolution of flood risk over time. The purpose of this study is to improve the understanding of the temporal aspects of flood risk through a combined analysis of the behavioral, engineering, and physical hazard aspects of flood risk. Additionally, the study aims to develop a new modeling approach for integrating behavior, policy, flood hazards, and engineering interventions. An agent-based model (ABM) is used to analyze the influence of flood protection measures, individual behavior, and the occurrence of floods and near-miss flood events on community flood risk. The ABM focuses on the following decisions and behaviors: dissemination of flood management information, installation of community flood protection, elevation of household mechanical equipment, and elevation of homes. The approach is place based, with a case study area in Fargo, North Dakota, but is focused on generalizable insights. Generally, community mitigation results in reduced future damage, and individual action, including mitigation and movement into and out of high-risk areas, can have a significant influence on community flood risk. The results of this study provide useful insights into the interplay between individual and community actions and how it affects the evolution of flood risk. This study lends insight into priorities for future work, including the development of more in-depth behavioral and decision rules at the individual and community level. © 2017 Society for Risk Analysis.

  20. A randomized, controlled trial to test the efficacy of an online, parent-based intervention for reducing the risks associated with college-student alcohol use

    Science.gov (United States)

    Donovan, Elizabeth; Wood, Mollie; Frayjo, Kezia; Black, Ryan A.; Surette, Daniel A.

    2011-01-01

    Alcohol consumption among college students remains a major public health concern. Universal, Web-based interventions to reduce risks associated with student alcohol consumption have been found to be effective in changing their alcohol-related behavior. Recent studies also indicate that parent-based interventions, delivered in booklet form, are effective. A parent-based intervention that is also Web-based may be well suited to a dispersed parent population; however, no such tool is currently available. The purpose of this study was to test the efficacy of an online parent-based intervention designed to (1) increase communication between parents and students about alcohol and (2) reduce risks associated with alcohol use to students. A total of 558 participants, comprising 279 parent-teen dyads, were enrolled in the study. The findings suggested that parents who participated in the online intervention were more likely to discuss protective behavioral strategies, particularly those related to manner of drinking and stopping/limiting drinking, with their teens, as compared with parents in an e-newsletter control group. Moreover, students whose parents received the intervention were more likely to use a range of protective behavioral strategies, particularly those related to manner of drinking and stopping/limiting drinking, as compared with students whose parents did not receive the intervention. A universal, online, parent-based intervention to reduce risks associated with student alcohol consumption may be an efficient and effective component of a college’s overall prevention strategy. PMID:21963316

  1. The stochastic risks of radioactive radiation - risk assessment, risk proportions, dose limits

    International Nuclear Information System (INIS)

    Lindackers, K.H.

    1990-01-01

    The latest data on the delayed injury to the a-bomb survivors of Hiroshima and Nagasaki reveal that the effects of radiation are more severe than was estimated in the past. However, the application of these data to small dose rate radiation exposure over longer periods of time leads to an overestimation of the actual risk. The future supersonic aviation schemes for altitudes within 20,000 m should include early personnel check-ups for assessment of the required protective measures. (orig./DG) [de

  2. MO-E-9A-01: Risk Based Quality Management: TG100 In Action

    Energy Technology Data Exchange (ETDEWEB)

    Huq, M [University of Pittsburgh Medical Center, Pittsburgh, PA (United States); Palta, J [Virginia Commonwealth University, Richmond, VA (United States); Dunscombe, P [Tom Baker Cancer Centre, Calgary, AB (Canada); Thomadsen, B [University of Wisconsin, Madison, WI (United States)

    2014-06-15

    One of the goals of quality management in radiation therapy is to gain high confidence that patients will receive the prescribed treatment correctly. To accomplish these goals professional societies such as the American Association of Physicists in Medicine (AAPM) has published many quality assurance (QA), quality control (QC), and quality management (QM) guidance documents. In general, the recommendations provided in these documents have emphasized on performing device-specific QA at the expense of process flow and protection of the patient against catastrophic errors. Analyses of radiation therapy incidents find that they are most often caused by flaws in the overall therapy process, from initial consult through final treatment, than by isolated hardware or computer failures detectable by traditional physics QA. This challenge is shared by many intrinsically hazardous industries. Risk assessment tools and analysis techniques have been developed to define, identify, and eliminate known and/or potential failures, problems, or errors, from a system, process and/or service before they reach the customer. These include, but are not limited to, process mapping, failure modes and effects analysis (FMEA), fault tree analysis (FTA), and establishment of a quality management program that best avoids the faults and risks that have been identified in the overall process. These tools can be easily adapted to radiation therapy practices because of their simplicity and effectiveness to provide efficient ways to enhance the safety and quality of treatment processes. Task group 100 (TG100) of AAPM has developed a risk-based quality management program that uses these tools. This session will be devoted to a discussion of these tools and how these tools can be used in a given radiotherapy clinic to develop a risk based QM program. Learning Objectives: Learn how to design a process map for a radiotherapy process. Learn how to perform a FMEA analysis for a given process. Learn what

  3. MO-E-9A-01: Risk Based Quality Management: TG100 In Action

    International Nuclear Information System (INIS)

    Huq, M; Palta, J; Dunscombe, P; Thomadsen, B

    2014-01-01

    One of the goals of quality management in radiation therapy is to gain high confidence that patients will receive the prescribed treatment correctly. To accomplish these goals professional societies such as the American Association of Physicists in Medicine (AAPM) has published many quality assurance (QA), quality control (QC), and quality management (QM) guidance documents. In general, the recommendations provided in these documents have emphasized on performing device-specific QA at the expense of process flow and protection of the patient against catastrophic errors. Analyses of radiation therapy incidents find that they are most often caused by flaws in the overall therapy process, from initial consult through final treatment, than by isolated hardware or computer failures detectable by traditional physics QA. This challenge is shared by many intrinsically hazardous industries. Risk assessment tools and analysis techniques have been developed to define, identify, and eliminate known and/or potential failures, problems, or errors, from a system, process and/or service before they reach the customer. These include, but are not limited to, process mapping, failure modes and effects analysis (FMEA), fault tree analysis (FTA), and establishment of a quality management program that best avoids the faults and risks that have been identified in the overall process. These tools can be easily adapted to radiation therapy practices because of their simplicity and effectiveness to provide efficient ways to enhance the safety and quality of treatment processes. Task group 100 (TG100) of AAPM has developed a risk-based quality management program that uses these tools. This session will be devoted to a discussion of these tools and how these tools can be used in a given radiotherapy clinic to develop a risk based QM program. Learning Objectives: Learn how to design a process map for a radiotherapy process. Learn how to perform a FMEA analysis for a given process. Learn what

  4. Determination and risk assessment of naturally occurring genotoxic and carcinogenic alkenylbenzenes in nutmeg-based plant food supplements.

    Science.gov (United States)

    Al-Malahmeh, Amer J; Alajlouni, Abdalmajeed M; Ning, Jia; Wesseling, Sebastiaan; Vervoort, Jacques; Rietjens, Ivonne M C M

    2017-10-01

    A risk assessment of nutmeg-based plant food supplements (PFS) containing different alkenylbenzenes was performed based on the alkenylbenzene levels quantified in a series of PFS collected via the online market. The estimated daily intake (EDI) of the alkenylbenzenes amounted to 0.3 to 312 μg kg -1 body weight (bw) for individual alkenylbenzenes, to 1.5 to 631 μg kg -1 bw when adding up the alkenylbenzene levels assuming equal potency, and to 0.4 to 295 μg kg -1 bw when expressed in safrole equivalents using toxic equivalency factors (TEFs). The margin of exposure approach (MOE) was used to evaluate the potential risks. Independent of the method used for the intake estimate, the MOE values obtained were generally lower than 10000 indicating a priority for risk management. When taking into account that PFS may be used for shorter periods of time and using Haber's rule to correct for shorter than lifetime exposure it was shown that limiting exposure to only 1 or 2 weeks would result in MOE values that would be, with the presently determined levels of alkenylbenzenes and proposed uses of the PFS, of low priority for risk management (MOE > 10000). It is concluded that the results of the present paper reveal that nutmeg-based PFS consumption following recommendations for daily intake especially for longer periods of time raise a concern. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

  5. Risk perception, risk evaluation and human values: cognitive bases of acceptability of a radioactive waste repository

    International Nuclear Information System (INIS)

    Earle, T.C.; Lindell, M.K.; Rankin, W.L.

    1981-07-01

    Public acceptance of radioactive waste management alternatives depends in part on public perception of the associated risks. Three aspects of those perceived risks were explored in this study: (1) synthetic measures of risk perception based on judgments of probability and consequences; (2) acceptability of hypothetical radioactive waste policies, and (3) effects of human values on risk perception. Both the work on synthetic measures of risk perception and on the acceptability of hypothetical policies included investigations of three categories of risk: (1) Short-term public risk (affecting persons living when the wastes are created), (2) Long-term public risk (affecting persons living after the time the wastes were created), and (3) Occupational risk (affecting persons working with the radioactive wastes). The human values work related to public risk perception in general, across categories of persons affected

  6. Web-based GIS: the vector-borne disease airline importation risk (VBD-AIR) tool.

    Science.gov (United States)

    Huang, Zhuojie; Das, Anirrudha; Qiu, Youliang; Tatem, Andrew J

    2012-08-14

    and robust informatics infrastructure by separating the modules of functionality through an ontological model for vector-borne disease. The VBD‒AIR tool is designed as an evidence base for visualizing the risks of vector-borne disease by air travel for a wide range of users, including planners and decisions makers based in state and local government, and in particular, those at international and domestic airports tasked with planning for health risks and allocating limited resources.

  7. Stroke risk associated with balloon based catheter ablation for atrial fibrillation: Rationale and design of the MACPAF Study

    Directory of Open Access Journals (Sweden)

    Schultheiss Heinz-Peter

    2010-07-01

    Full Text Available Abstract Background Catheter ablation of the pulmonary veins has become accepted as a standard therapeutic approach for symptomatic paroxysmal atrial fibrillation (AF. However, there is some evidence for an ablation associated (silent stroke risk, lowering the hope to limit the stroke risk by restoration of rhythm over rate control in AF. The purpose of the prospective randomized single-center study "Mesh Ablator versus Cryoballoon Pulmonary Vein Ablation of Symptomatic Paroxysmal Atrial Fibrillation" (MACPAF is to compare the efficacy and safety of two balloon based pulmonary vein ablation systems in patients with symptomatic paroxysmal AF. Methods/Design Patients are randomized 1:1 for the Arctic Front® or the HD Mesh Ablator® catheter for left atrial catheter ablation (LACA. The predefined endpoints will be assessed by brain magnetic resonance imaging (MRI, neuro(psychological tests and a subcutaneously implanted reveal recorder for AF detection. According to statistics 108 patients will be enrolled. Discussion Findings from the MACPAF trial will help to balance the benefits and risks of LACA for symptomatic paroxysmal AF. Using serial brain MRIs might help to identify patients at risk for LACA-associated cerebral thromboembolism. Potential limitations of the study are the single-center design, the existence of a variety of LACA-catheters, the missing placebo-group and the impossibility to assess the primary endpoint in a blinded fashion. Trial registration clinicaltrials.gov NCT01061931

  8. Development of a risk-based approach to Hanford Site cleanup

    International Nuclear Information System (INIS)

    Hesser, W.A.; Daling, P.M.; Baynes, P.A.

    1995-06-01

    In response to a request from Mr. Thomas Grumbly, Assistant Secretary of Energy for Environmental Management, the Hanford Site contractors developed a conceptual set of risk-based cleanup strategies that (1) protect the public, workers, and environment from unacceptable risks; (2) are executable technically; and (3) fit within an expected annual funding profile of 1.05 billion dollars. These strategies were developed because (1) the US Department of Energy and Hanford Site budgets are being reduced, (2) stakeholders are dissatisfied with the perceived rate of cleanup, (3) the US Congress and the US Department of Energy are increasingly focusing on risk and riskreduction activities, (4) the present strategy is not integrated across the Site and is inconsistent in its treatment of similar hazards, (5) the present cleanup strategy is not cost-effective from a risk-reduction or future land use perspective, and (6) the milestones and activities in the Tri-Party Agreement cannot be achieved with an anticipated funding of 1.05 billion dollars annually. The risk-based strategies described herein were developed through a systems analysis approach that (1) analyzed the cleanup mission; (2) identified cleanup objectives, including risk reduction, land use, and mortgage reduction; (3) analyzed the existing baseline cleanup strategy from a cost and risk perspective; (4) developed alternatives for accomplishing the cleanup mission; (5) compared those alternatives against cleanup objectives; and (6) produced conclusions and recommendations regarding the current strategy and potential risk-based strategies

  9. The role of hazard- and risk-based approaches in ensuring food safety

    DEFF Research Database (Denmark)

    Barlow, Susan M.; Boobis, Alan R.; Bridges, Jim

    2015-01-01

    action. Risk-based approaches allow consideration of exposure in assessing whether there may be unacceptable risks to health. Scope and approach The advantages and disadvantages of hazard- and risk-based approaches for ensuring the safety of food chemicals, allergens, ingredients and microorganisms were...

  10. Limits in point to point resolution of MOS based pixels detector arrays

    Science.gov (United States)

    Fourches, N.; Desforge, D.; Kebbiri, M.; Kumar, V.; Serruys, Y.; Gutierrez, G.; Leprêtre, F.; Jomard, F.

    2018-01-01

    In high energy physics point-to-point resolution is a key prerequisite for particle detector pixel arrays. Current and future experiments require the development of inner-detectors able to resolve the tracks of particles down to the micron range. Present-day technologies, although not fully implemented in actual detectors, can reach a 5-μm limit, this limit being based on statistical measurements, with a pixel-pitch in the 10 μm range. This paper is devoted to the evaluation of the building blocks for use in pixel arrays enabling accurate tracking of charged particles. Basing us on simulations we will make here a quantitative evaluation of the physical and technological limits in pixel size. Attempts to design small pixels based on SOI technology will be briefly recalled here. A design based on CMOS compatible technologies that allow a reduction of the pixel size below the micrometer is introduced here. Its physical principle relies on a buried carrier-localizing collecting gate. The fabrication process needed by this pixel design can be based on existing process steps used in silicon microelectronics. The pixel characteristics will be discussed as well as the design of pixel arrays. The existing bottlenecks and how to overcome them will be discussed in the light of recent ion implantation and material characterization experiments.

  11. Prototype Biology-Based Radiation Risk Module Project

    Science.gov (United States)

    Terrier, Douglas; Clayton, Ronald G.; Patel, Zarana; Hu, Shaowen; Huff, Janice

    2015-01-01

    Biological effects of space radiation and risk mitigation are strategic knowledge gaps for the Evolvable Mars Campaign. The current epidemiology-based NASA Space Cancer Risk (NSCR) model contains large uncertainties (HAT #6.5a) due to lack of information on the radiobiology of galactic cosmic rays (GCR) and lack of human data. The use of experimental models that most accurately replicate the response of human tissues is critical for precision in risk projections. Our proposed study will compare DNA damage, histological, and cell kinetic parameters after irradiation in normal 2D human cells versus 3D tissue models, and it will use a multi-scale computational model (CHASTE) to investigate various biological processes that may contribute to carcinogenesis, including radiation-induced cellular signaling pathways. This cross-disciplinary work, with biological validation of an evolvable mathematical computational model, will help reduce uncertainties within NSCR and aid risk mitigation for radiation-induced carcinogenesis.

  12. Caveats and limitations of plate reader-based high-throughput kinetic measurements of intracellular calcium levels

    International Nuclear Information System (INIS)

    Heusinkveld, Harm J.; Westerink, Remco H.S.

    2011-01-01

    Calcium plays a crucial role in virtually all cellular processes, including neurotransmission. The intracellular Ca 2+ concentration ([Ca 2+ ] i ) is therefore an important readout in neurotoxicological and neuropharmacological studies. Consequently, there is an increasing demand for high-throughput measurements of [Ca 2+ ] i , e.g. using multi-well microplate readers, in hazard characterization, human risk assessment and drug development. However, changes in [Ca 2+ ] i are highly dynamic, thereby creating challenges for high-throughput measurements. Nonetheless, several protocols are now available for real-time kinetic measurement of [Ca 2+ ] i in plate reader systems, though the results of such plate reader-based measurements have been questioned. In view of the increasing use of plate reader systems for measurements of [Ca 2+ ] i a careful evaluation of current technologies is warranted. We therefore performed an extensive set of experiments, using two cell lines (PC12 and B35) and two fluorescent calcium-sensitive dyes (Fluo-4 and Fura-2), for comparison of a linear plate reader system with single cell fluorescence microscopy. Our data demonstrate that the use of plate reader systems for high-throughput real-time kinetic measurements of [Ca 2+ ] i is associated with many pitfalls and limitations, including erroneous sustained increases in fluorescence, limited sensitivity and lack of single cell resolution. Additionally, our data demonstrate that probenecid, which is often used to prevent dye leakage, effectively inhibits the depolarization-evoked increase in [Ca 2+ ] i . Overall, the data indicate that the use of current plate reader-based strategies for high-throughput real-time kinetic measurements of [Ca 2+ ] i is associated with caveats and limitations that require further investigation. - Research highlights: → The use of plate readers for high-throughput screening of intracellular Ca 2+ is associated with many pitfalls and limitations. → Single cell

  13. Risk-based Strategy to Determine Testing Requirement for the Removal of Residual Process Reagents as Process-related Impurities in Bioprocesses.

    Science.gov (United States)

    Qiu, Jinshu; Li, Kim; Miller, Karen; Raghani, Anil

    2015-01-01

    The purpose of this article is to recommend a risk-based strategy for determining clearance testing requirements of the process reagents used in manufacturing biopharmaceutical products. The strategy takes account of four risk factors. Firstly, the process reagents are classified into two categories according to their safety profile and history of use: generally recognized as safe (GRAS) and potential safety concern (PSC) reagents. The clearance testing of GRAS reagents can be eliminated because of their safe use historically and process capability to remove these reagents. An estimated safety margin (Se) value, a ratio of the exposure limit to the estimated maximum reagent amount, is then used to evaluate the necessity for testing the PSC reagents at an early development stage. The Se value is calculated from two risk factors, the starting PSC reagent amount per maximum product dose (Me), and the exposure limit (Le). A worst-case scenario is assumed to estimate the Me value, that is common. The PSC reagent of interest is co-purified with the product and no clearance occurs throughout the entire purification process. No clearance testing is required for this PSC reagent if its Se value is ≥1; otherwise clearance testing is needed. Finally, the point of the process reagent introduction to the process is also considered in determining the necessity of the clearance testing for process reagents. How to use the measured safety margin as a criterion for determining PSC reagent testing at process characterization, process validation, and commercial production stages are also described. A large number of process reagents are used in the biopharmaceutical manufacturing to control the process performance. Clearance testing for all of the process reagents will be an enormous analytical task. In this article, a risk-based strategy is described to eliminate unnecessary clearance testing for majority of the process reagents using four risk factors. The risk factors included

  14. Biomechanical rupture risk assessment of abdominal aortic aneurysms based on a novel probabilistic rupture risk index.

    Science.gov (United States)

    Polzer, Stanislav; Gasser, T Christian

    2015-12-06

    A rupture risk assessment is critical to the clinical treatment of abdominal aortic aneurysm (AAA) patients. The biomechanical AAA rupture risk assessment quantitatively integrates many known AAA rupture risk factors but the variability of risk predictions due to model input uncertainties remains a challenging limitation. This study derives a probabilistic rupture risk index (PRRI). Specifically, the uncertainties in AAA wall thickness and wall strength were considered, and wall stress was predicted with a state-of-the-art deterministic biomechanical model. The discriminative power of PRRI was tested in a diameter-matched cohort of ruptured (n = 7) and intact (n = 7) AAAs and compared to alternative risk assessment methods. Computed PRRI at 1.5 mean arterial pressure was significantly (p = 0.041) higher in ruptured AAAs (20.21(s.d. 14.15%)) than in intact AAAs (3.71(s.d. 5.77)%). PRRI showed a high sensitivity and specificity (discriminative power of 0.837) to discriminate between ruptured and intact AAA cases. The underlying statistical representation of stochastic data of wall thickness, wall strength and peak wall stress had only negligible effects on PRRI computations. Uncertainties in AAA wall stress predictions, the wide range of reported wall strength and the stochastic nature of failure motivate a probabilistic rupture risk assessment. Advanced AAA biomechanical modelling paired with a probabilistic rupture index definition as known from engineering risk assessment seems to be superior to a purely deterministic approach. © 2015 The Author(s).

  15. Safety regulations: Implications of the new risk perspectives

    International Nuclear Information System (INIS)

    Aven, T.; Ylönen, M.

    2016-01-01

    The current safety regulations for industrial activities are to a large extent functionally oriented and risk-based (informed), expressing what to achieve rather than the means and solutions needed. They are founded on a probability-based perspective on risk, with the use of risk assessment, risk acceptance criteria and tolerability limits. In recent years several risk researchers have argued for the adoption of some new types of risk perspectives which highlight uncertainties rather than probabilities in the way risk is defined, the point being to better reflect the knowledge, and lack of knowledge, dimension of risk. The Norwegian Petroleum Safety Authority has recently implemented such a perspective. The new ISO standard 31000 is based on a similar thinking. In this paper we discuss the implications of these perspectives on safety regulation, using the oil & gas and nuclear industries as illustrations. Several suggestions for how to develop the current safety regulations in line with the ideas of the new risk perspectives are outlined, including some related to the use of risk acceptance criteria (tolerability limits). We also point to potential obstacles and incentives that the larger societal and institutional setting may impose on industry as regards the adoption of the new risk perspectives. - Highlights: • Some new types of risk perspectives have been promoted. • They have been implemented for example by the Norwegian Petroleum Safety Authority. • The paper studies the implication of these perspectives on the risk regulation. • Suggestions for how to develop the regulations are provided • Obstacles and incentives for the implementation of the perspectives are pointed to.

  16. Promotion of technical harmonisation on risk-based decision making

    International Nuclear Information System (INIS)

    Kirchsteiger, Christian; Cojazzi, Giacomo

    2000-01-01

    The EC-JRC International Workshop on Promotion of Technical Harmonisation on Risk-Based Decision Making, held at Stresa and Ispra, Italy, 22-25 May 2000, was an experts meeting to discuss the possible need of developing an internationally accepted generic 'standard' for risk-based decision making.This paper briefly describes the workshop background, its organisation and summarises its main results and conclusions; it reflects the personal opinions of the authors and in no way commits the European Commission. (author)

  17. Preclinical Torsades-de-Pointes screens: advantages and limitations of surrogate and direct approaches in evaluating proarrhythmic risk.

    Science.gov (United States)

    Gintant, Gary A

    2008-08-01

    The successful development of novel drugs requires the ability to detect (and avoid) compounds that may provoke Torsades-de-Pointes (TdeP) arrhythmia while endorsing those compounds with minimal torsadogenic risk. As TdeP is a rare arrhythmia not readily observed during clinical or post-marketing studies, numerous preclinical models are employed to assess delayed or altered ventricular repolarization (surrogate markers linked to enhanced proarrhythmic risk). This review evaluates the advantages and limitations of selected preclinical models (ranging from the simplest cellular hERG current assay to the more complex in vitro perfused ventricular wedge and Langendorff heart preparations and in vivo chronic atrio-ventricular (AV)-node block model). Specific attention is paid to the utility of concentration-response relationships and "risk signatures" derived from these studies, with the intention of moving beyond predicting clinical QT prolongation and towards prediction of TdeP risk. While the more complex proarrhythmia models may be suited to addressing questionable or conflicting proarrhythmic signals obtained with simpler preclinical assays, further benchmarking of proarrhythmia models is required for their use in the robust evaluation of safety margins. In the future, these models may be able to reduce unwarranted attrition of evolving compounds while becoming pivotal in the balanced integrated risk assessment of advancing compounds.

  18. Risk Reduction Education: Voices from the Field

    Science.gov (United States)

    Lamorey, Suzanne

    2010-01-01

    Teens with disabilities need information about risk topics such as addiction, abuse, sex, and delinquency to make healthy choices as they participate in mainstream society. This article presents questionnaire-based information provided by special educators in secondary schools about their efforts, limitations, and needs in providing risk reduction…

  19. Risk-Based Sampling: I Don't Want to Weight in Vain.

    Science.gov (United States)

    Powell, Mark R

    2015-12-01

    Recently, there has been considerable interest in developing risk-based sampling for food safety and animal and plant health for efficient allocation of inspection and surveillance resources. The problem of risk-based sampling allocation presents a challenge similar to financial portfolio analysis. Markowitz (1952) laid the foundation for modern portfolio theory based on mean-variance optimization. However, a persistent challenge in implementing portfolio optimization is the problem of estimation error, leading to false "optimal" portfolios and unstable asset weights. In some cases, portfolio diversification based on simple heuristics (e.g., equal allocation) has better out-of-sample performance than complex portfolio optimization methods due to estimation uncertainty. Even for portfolios with a modest number of assets, the estimation window required for true optimization may imply an implausibly long stationary period. The implications for risk-based sampling are illustrated by a simple simulation model of lot inspection for a small, heterogeneous group of producers. © 2015 Society for Risk Analysis.

  20. Obesity as a risk factor for developing functional limitation among older adults: A conditional inference tree analysis

    Science.gov (United States)

    Objective: To examine the risk factors of developing functional decline and make probabilistic predictions by using a tree-based method that allows higher order polynomials and interactions of the risk factors. Methods: The conditional inference tree analysis, a data mining approach, was used to con...

  1. A Knowledge-Base for a Personalized Infectious Disease Risk Prediction System.

    Science.gov (United States)

    Vinarti, Retno; Hederman, Lucy

    2018-01-01

    We present a knowledge-base to represent collated infectious disease risk (IDR) knowledge. The knowledge is about personal and contextual risk of contracting an infectious disease obtained from declarative sources (e.g. Atlas of Human Infectious Diseases). Automated prediction requires encoding this knowledge in a form that can produce risk probabilities (e.g. Bayesian Network - BN). The knowledge-base presented in this paper feeds an algorithm that can auto-generate the BN. The knowledge from 234 infectious diseases was compiled. From this compilation, we designed an ontology and five rule types for modelling IDR knowledge in general. The evaluation aims to assess whether the knowledge-base structure, and its application to three disease-country contexts, meets the needs of personalized IDR prediction system. From the evaluation results, the knowledge-base conforms to the system's purpose: personalization of infectious disease risk.

  2. The Two C”s of the Risk-Based Approach to Goal based Standards: Challenges and Caveats

    DEFF Research Database (Denmark)

    Kontovas, Christos A.; Psaraftis, Harilaos N.; Zachariadis, Panos

    2007-01-01

    industry has begun to move from a reactive to a proactive approach to safety through “Formal Safety Assessment” (FSA) and “Goal Based Standards” (GBS). FSA was introduced by the IMO as “a rational and systematic process for accessing the risk related to maritime safety and the protection of the marine...... environment and for evaluating the costs and benefits of IMO’s options for reducing these risks”. The recent GBS approach aims to be another proactive instrument, and there has been recent discussion in the IMO on the possible links between FSA and GBS. This paper attempts to clarify some widely used......, but confusing to many, notions such as Risk Based Rulemaking vs. Risk Based Design, and IMO's GBS Traditional Approach vs. Safety Level Approach, and the implications of their use, or misuse, to future ship rulemaking, design and safety. The paper elaborates on some identified weaknesses of the risk based...

  3. The Key to Sustainable Risk Governance

    DEFF Research Database (Denmark)

    Andersen, Torben Juul; Shaw, Gregory L.

    by relevant literatures on risk governance and values-based management complemented with insights from case analyses and empirical studies. Findings: – The paper explains why formal risk management approaches have limitations and outlines how the presence of official policies and codes of conduct...... failed to do the job when the leadership in reality gave first priority to profits at the expense of the stated environmental values. The prioritized code of the US Coast Guard is used to illustrate the circumstances where core values support effective crisis, disaster and risk management outcomes......Purpose: – The article brings attention to the importance of corporate values and concrete leadership enactment of those values as a necessary condition for effective risk management outcomes. Design/methodology/approach: – The content is based on practice-based research experiences supported...

  4. Proposed Robust Entanglement-Based Magnetic Field Sensor Beyond the Standard Quantum Limit.

    Science.gov (United States)

    Tanaka, Tohru; Knott, Paul; Matsuzaki, Yuichiro; Dooley, Shane; Yamaguchi, Hiroshi; Munro, William J; Saito, Shiro

    2015-10-23

    Recently, there have been significant developments in entanglement-based quantum metrology. However, entanglement is fragile against experimental imperfections, and quantum sensing to beat the standard quantum limit in scaling has not yet been achieved in realistic systems. Here, we show that it is possible to overcome such restrictions so that one can sense a magnetic field with an accuracy beyond the standard quantum limit even under the effect of decoherence, by using a realistic entangled state that can be easily created even with current technology. Our scheme could pave the way for the realizations of practical entanglement-based magnetic field sensors.

  5. An evaluation of the exemption level for the radiation protection regulation based on the social risk acceptance in Korea

    International Nuclear Information System (INIS)

    Yoon, Ki Don

    1998-02-01

    Radiation protection is based not only on the science but also on the political, social, economical and emotional factors, so a policy decision for a factor like the exemption level in this field must be considered social expectation and valuation as well as scientific evaluation. In this paper, an attempt was made to get a rationale on the exemption level, which has a significant meaning in radiation protection, by means of surveying the social risk acceptance in Korea. Risk perception data were collected by mail surveys to the respondents randomly selected in the city of Seoul. A poor response rate, 156 out of 400, was observed. The result showed that the majority of the respondents agreed upon setting a de mini mis level of risk and the favoured de mini mis level appeared to be in the range of 10 -6 yr -1 to 10 -7 yr -1 , which is consistent with the level suggested by other organizations: ICRP, EPA and NRPB. Approximately the same risk level, unfortunately, was obtained for the risk limits against a harmful agent, which makes no sense. It can be attributed to mis-communication due to the questionnaires inadequately designed. The acceptable risk level for a single practice was selected to be 1/100 or less of the risk limits, which seemed overly conservative, but could be understood in the light of the public attitude of outrage. There seems to be tendency that the public recognize the risk significant if it is not de mini mis. This study should not be regarded as one giving a satisfactory conclusion but a preliminary attempt to evaluate the acceptable risk level. More endeavors in design of questionnaires are needed to communicate successfully with the members of the public

  6. A risk-based auditing process for pharmaceutical manufacturers.

    Science.gov (United States)

    Vargo, Susan; Dana, Bob; Rangavajhula, Vijaya; Rönninger, Stephan

    2014-01-01

    The purpose of this article is to share ideas on developing a risk-based model for the scheduling of audits (both internal and external). Audits are a key element of a manufacturer's quality system and provide an independent means of evaluating the manufacturer's or the supplier/vendor's compliance status. Suggestions for risk-based scheduling approaches are discussed in the article. Pharmaceutical manufacturers are required to establish and implement a quality system. The quality system is an organizational structure defining responsibilities, procedures, processes, and resources that the manufacturer has established to ensure quality throughout the manufacturing process. Audits are a component of the manufacturer's quality system and provide a systematic and an independent means of evaluating the manufacturer's overall quality system and compliance status. Audits are performed at defined intervals for a specified duration. The intention of the audit process is to focus on key areas within the quality system and may not cover all relevant areas during each audit. In this article, the authors provide suggestions for risk-based scheduling approaches to aid pharmaceutical manufacturers in identifying the key focus areas for an audit.

  7. Volatility and correlation-based systemic risk measures in the US market

    Science.gov (United States)

    Civitarese, Jamil

    2016-10-01

    This paper deals with the problem of how to use simple systemic risk measures to assess portfolio risk characteristics. Using three simple examples taken from previous literature, one based on raw and partial correlations, another based on the eigenvalue decomposition of the covariance matrix and the last one based on an eigenvalue entropy, a Granger-causation analysis revealed some of them are not always a good measure of risk in the S&P 500 and in the VIX. The measures selected do not Granger-cause the VIX index in all windows selected; therefore, in the sense of risk as volatility, the indicators are not always suitable. Nevertheless, their results towards returns are similar to previous works that accept them. A deeper analysis has shown that any symmetric measure based on eigenvalue decomposition of correlation matrices, however, is not useful as a measure of "correlation" risk. The empirical counterpart analysis of this proposition stated that negative correlations are usually small and, therefore, do not heavily distort the behavior of the indicator.

  8. A risk-based model for maintenance decision support of civil structures using RAMS

    NARCIS (Netherlands)

    Viana Da Rocha, T. C.; Stipanovic, I.; Hartmann, A.; Bakker, J.

    2017-01-01

    As a cornerstone of transportation asset management, risk-based approaches have been used to support maintenance decisions of civil structures. However, ambiguous and subjective risk criteria and inconsistency on the use of risk-based approaches can lead to a fuzzy understanding of the risks

  9. Case studies: Risk-based analysis of technical specifications

    International Nuclear Information System (INIS)

    Wagner, D.P.; Minton, L.A.; Gaertner, J.P.

    1987-01-01

    The SOCRATES computer program uses the results of a Probabilistic Risk Assessment (PRA) or a system level risk analysis to calculate changes in risk due to changes in the surveillance test interval and/or the allowed outage time stated in the technical specification. The computer program can accommodate various testing strategies (such as staggered or simultaneous testing) to allow modeling of component testing as it is carried out at a plant. The methods and computer program are an integral part of a larger decision process aimed at determining benefits from technical specification changes. These benefits can include cost savings to the utilities by reducing forced shutdowns with no adverse impacts on risk. Three summaries of case study applications are included to demonstrate the types of results that can be achieved through risk-based evaluation of technical specifications. (orig.)

  10. Risk Analysis Method Based on FMEA for Transmission Line in Lightning Hazards

    Directory of Open Access Journals (Sweden)

    You-Yuan WANG

    2014-05-01

    Full Text Available Failure rate of transmission line and reliability of power system are significantly affected by Lightning meteorological factor. In view of the complexity and variability of Lightning meteorological factors, this paper presents lightning trip-out rate model of transmission line in considering distribution of ground flash density and lightning day hours. Meanwhile, presents a failure rate model of transmission line in different condition, and a risk analysis method for transmission line considering multiple risk factors based on risk quantification. This method takes Lightning meteorological factor as the main evaluation standard, and establishes risk degree evaluation system for transmission line including another five evaluation standard. Put forward the risk indicators by quantify the risk factors based on experience date of transmission line in service. Based on the risk indexes comprehensive evaluation is conducted, and the evaluation result closer to practice is achieved, providing basis for transmission line risk warning and maintenance strategy. Through the risk analysis for 220 kV transmission line in a certain power supply bureau, the effectiveness of the proposed method is validated.

  11. Sugary food and beverage consumption and epithelial ovarian cancer risk: a population-based case-control study.

    Science.gov (United States)

    King, Melony G; Olson, Sara H; Paddock, Lisa; Chandran, Urmila; Demissie, Kitaw; Lu, Shou-En; Parekh, Niyati; Rodriguez-Rodriguez, Lorna; Bandera, Elisa V

    2013-02-27

    Ovarian cancer is the deadliest gynecologic cancer in the US. The consumption of refined sugars has increased dramatically over the past few decades, accounting for almost 15% of total energy intake. Yet, there is limited evidence on how sugar consumption affects ovarian cancer risk. We evaluated ovarian cancer risk in relation to sugary foods and beverages, and total and added sugar intakes in a population-based case-control study. Cases were women with newly diagnosed epithelial ovarian cancer, older than 21 years, able to speak English or Spanish, and residents of six counties in New Jersey. Controls met same criteria as cases, but were ineligible if they had both ovaries removed. A total of 205 cases and 390 controls completed a phone interview, food frequency questionnaire, and self-recorded waist and hip measurements. Based on dietary data, we computed the number of servings of dessert foods, non-dessert foods, sugary drinks and total sugary foods and drinks for each participant. Total and added sugar intakes (grams/day) were also calculated. Multiple logistic regression models were used to estimate odds ratios and 95% confidence intervals for food and drink groups and total and added sugar intakes, while adjusting for major risk factors. We did not find evidence of an association between consumption of sugary foods and beverages and risk, although there was a suggestion of increased risk associated with sugary drink intake (servings per 1,000 kcal; OR=1.63, 95% CI: 0.94-2.83). Overall, we found little indication that sugar intake played a major role on ovarian cancer development.

  12. Automatic identification of web-based risk markers for health events

    DEFF Research Database (Denmark)

    Yom-Tov, Elad; Borsa, Diana; Hayward, Andrew C.

    2015-01-01

    but these are often limited in size and cost and can fail to take full account of diseases where there are social stigmas or to identify transient acute risk factors. Objective: Here we report that Web search engine queries coupled with information on Wikipedia access patterns can be used to infer health events...

  13. Evaluation of a community-based participatory physical activity promotion project: effect on cardiovascular disease risk profiles of school employees

    Directory of Open Access Journals (Sweden)

    Kobza Cee E

    2010-06-01

    Full Text Available Abstract Background The efficacy of physical activity in improving cardiovascular disease (CVD risk profiles has been well established. However, the effectiveness of health promotion programs implemented at the community level remains controversial. This study evaluated a school-based work-site physical activity program. Methods Using a community-based participatory research model, a work-site wellness intervention was implemented in a rural public school system in Southwestern Oklahoma. During the 2005-2006 school year, 187 participants (mean age 45 years completed a pre intervention screening for CVD risk factors followed by a physical activity promotion program. Post intervention screening was conducted after a 6 month period. During both screening sessions, body composition, blood pressure, lipids, glucose and self-reported physical activity levels were assessed. The focus of the intervention was on promoting physical activity. Opportunities for in school physical activity were created by marking hallways, adding a treadmill in each school, and allowing teachers to use planning periods for physical activity. Results During the post intervention screening, compared to pre intervention levels, participants had lower total, low, and high density lipoprotein-cholesterol (t = 5.9, p Conclusions A successful participatory program was associated with improvements in several CVD risk factors among school employees. Limitations of this study such as seasonal variation in the outcome variables and lack of a control group limit our ability to draw solid conclusions about the effectiveness of the intervention.

  14. Questionnaire-based risk assessment system

    International Nuclear Information System (INIS)

    Sakajo, Satoko; Ohi, Tadashi

    2004-01-01

    In order to reduce human errors efficiently, it is important to evaluate error-likely tasks and improve them. There are a lot of evaluation methods, for example, experimental evaluation methods, investigations by the expert of human factors, checking guidelines, estimating human error probabilities, and so on. There are roughly two problems in those methods. (1) Qualitative evaluation methods do not evaluate how likely human errors will occur and do not estimate how effective the countermeasure is in reducing human error. (2) Most of the quantitative evaluation methods and detailed analysis methods require expert's judgment. We developed a questionnaire-based risk assessment method and its system. In this paper, we introduce the concept of the method, realization, and applications to a maintenance procedure of a nuclear power plant and an elevator. The feature of the method is that it is so simple and the inexpert can easily evaluate the risk of human error. Furthermore, because it is provided as an application service provider system, a lot of evaluators can use it simultaneously through internet and it is easy to collect and sum up the responses. We confirmed that it is useful to evaluate the risk of human error, analyze the problem, and estimate the effectiveness of countermeasures in advance through the applications. (author)

  15. Risk perception, risk evaluation and human values: cognitive bases of acceptability of a radioactive waste repository

    Energy Technology Data Exchange (ETDEWEB)

    Earle, T.C.; Lindell, M.K.; Rankin, W.L.

    1981-07-01

    Public acceptance of radioactive waste management alternatives depends in part on public perception of the associated risks. Three aspects of those perceived risks were explored in this study: (1) synthetic measures of risk perception based on judgments of probability and consequences; (2) acceptability of hypothetical radioactive waste policies, and (3) effects of human values on risk perception. Both the work on synthetic measures of risk perception and on the acceptability of hypothetical policies included investigations of three categories of risk: (1) Short-term public risk (affecting persons living when the wastes are created), (2) Long-term public risk (affecting persons living after the time the wastes were created), and (3) Occupational risk (affecting persons working with the radioactive wastes). The human values work related to public risk perception in general, across categories of persons affected. Respondents were selected according to a purposive sampling strategy.

  16. Limited output transcranial electrical stimulation (LOTES-2017): Engineering principles, regulatory statutes, and industry standards for wellness, over-the-counter, or prescription devices with low risk.

    Science.gov (United States)

    Bikson, Marom; Paneri, Bhaskar; Mourdoukoutas, Andoni; Esmaeilpour, Zeinab; Badran, Bashar W; Azzam, Robin; Adair, Devin; Datta, Abhishek; Fang, Xiao Hui; Wingeier, Brett; Chao, Daniel; Alonso-Alonso, Miguel; Lee, Kiwon; Knotkova, Helena; Woods, Adam J; Hagedorn, David; Jeffery, Doug; Giordano, James; Tyler, William J

    regard to output performance and standing regulation, the availability of tDCS, tACS, or tPCS to the public would not introduce risk, provided such devices are responsibly manufactured and legally marketed. In Part 3, we develop voluntary manufacturer guidance for limited output tES that is aligned with current regulatory standards. Based on established medical engineering and scientific principles, we outline a robust and transparent technical framework for ensuring limited output tES devices are designed to minimize risks, while also supporting access and innovation. Alongside applicable medical and government activities, this voluntary industry standard (LOTES-2017) further serves an important role in supporting informed decisions by the public. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. Making the EU "Risk Window" transparent: The normative foundations of the environmental risk assessment of GMOs

    DEFF Research Database (Denmark)

    Jensen, K.K.; Gamborg, C.; Madsen, K.H.

    2003-01-01

    In Europe, there seems to be widespread, morally based scepticism about the use of GMOs in food production. In response to this scepticism, the revised EU directive 2001/18/EC on the deliberate release into the environment of genetically modified organisms stresses the importance of respecting...... assessment and approval of GMOs outlined in the directive. An environmental risk assessment views the world through a "risk window" that only makes visible that which has been predefined as a relevant risk. The importance of the value judgements that define the risk window consists in limiting...

  18. 48 CFR 39.102 - Management of risk.

    Science.gov (United States)

    2010-10-01

    ... are not limited to: prudent project management; use of modular contracting; thorough acquisition... evaluation of risk-based assessment data; prototyping prior to implementation; post implementation reviews to...

  19. Sarcopenic obesity: A probable risk factor for dose limiting toxicity during neo-adjuvant chemotherapy in oesophageal cancer patients.

    Science.gov (United States)

    Anandavadivelan, Poorna; Brismar, Torkel B; Nilsson, Magnus; Johar, Asif M; Martin, Lena

    2016-06-01

    Profound weight loss and malnutrition subsequent to severe dysphagia and cancer cachexia are cardinal symptoms in oesophageal cancer (OC). Low muscle mass/sarcopenia has been linked to toxicity during neo-adjuvant therapy in other cancers, with worser effects in sarcopenic obesity. In this study the association between sarcopenia and/or sarcopenic obesity and dose limiting toxicity (DLT) during cycle one chemotherapy in resectable OC patients was evaluated. Body composition was assessed from computed tomography scans of 72 consecutively diagnosed OC patients. Lean body mass and body fat mass were estimated. Patients were grouped as sarcopenic or non-sarcopenic based on pre-defined gender-specific cut-offs for sarcopenia, and as underweight/normal (BMI sarcopenia combined with overweight and obesity. DLT was defined as temporary reduction/delay or permanent discontinuation of drugs due to adverse effects. Odds ratios for developing toxicity were ascertained using multiple logistic regression. Of 72 patients, 85% (n = 61) were males. Sarcopenia and sarcopenic obesity were present in 31 (43%) and 10 (14%), respectively, prior to chemotherapy. Sarcopenic patients had significantly lower adipose tissue index (p = 0.02) compared to non-sarcopenic patients. Patients with DLT (n = 24) had lower skeletal muscle mass (p = 0.04) than those without DLT. Sarcopenic patients (OR = 2.47; 95% CI: 0.88-6.93) showed a trend towards increased DLT risk (p < 0.10). Logistic regression with BMI as an interaction term indicated higher DLT risk in sarcopenic patients with normal BMI (OR = 1.60; 95% CI 0.30-8.40), but was non-significant. In the sarcopenic obese, risk of DLT increased significantly (OR = 5.54; 95% CI 1.12-27.44). Sarcopenic and sarcopenic obese OC patients may be at a higher risk for developing DLT during chemotherapy compared to non-sarcopenic OC patients. Copyright © 2015 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All

  20. A Risk-based Assessment And Management Framework For Multipollutant Air Quality

    OpenAIRE

    Frey, H. Christopher; Hubbell, Bryan

    2009-01-01

    The National Research Council recommended both a risk- and performance-based multipollutant approach to air quality management. Specifically, management decisions should be based on minimizing the exposure to, and risk of adverse effects from, multiple sources of air pollution and that the success of these decisions should be measured by how well they achieved this objective. We briefly describe risk analysis and its application within the current approach to air quality management. Recommend...

  1. Multi-site risk-based project planning, optimization, sequencing, & budgeting process and tool for the integrated facility disposition project

    International Nuclear Information System (INIS)

    Nelson, J.G.; Castillo, C.; Huntsman, J.; Killoy, S.; Lucek, H.; Marks, T.C.

    2011-01-01

    Faced with the Department of Energy (DOE) Complex Transformation, National Nuclear Security Administration (NNSA) was tasked with developing an integrated plan for the decommissioning of over 400 facilities and 300 environmental remediation units, as well as the many reconfiguration and modernization projects at the Oak Ridge National Laboratory (ORNL) and Y-12 Complex. Manual scheduling of remediation activities is time-consuming and inherently introduces bias of the scheduler or organization into the process. Clearly a well-defined process, quantitative risk-based tool was needed to develop an objective, unbiased baseline sequence and schedule with a sound technical foundation for the Integrated Facility Disposition Project (IFDP). Faced with limited available data, innovation was needed to extrapolate intelligent relative data for key risk parameters based on known data elements. The IFDP Supermodel was customized and expanded to provide this capability for conceptual planning of diverse project portfolios and multiple sites. (author)

  2. A Comparative Study Between Strain And Stress Based Forming Limit Analysis By Applying Several Phenomenological Yield Criteria

    International Nuclear Information System (INIS)

    Butuc, Marilena C.; Vincze, Gabriela T.; Gracio, Jose J.; Barata da Rocha, A.

    2005-01-01

    The present work aims at analyzing a comparative study between the strain-based forming limit criterion (FLD) and the stress-based forming limit criterion (FLSD), under linear and complex strain paths. The selected material is an AA5182-0 aluminium alloy. Some relevant remarks about stress-based forming limit criterion concept are presented

  3. Trust-Based Information Risk Management in a Supply Chain Network

    OpenAIRE

    Yanjun Zuo; Wen-Chen Hu

    2009-01-01

    Information risk management is crucial for an organization operating in an increasingly integrated and intensively communicated environment to mitigate risks and ensure core business functions. Given the open and dynamic nature of a supply chain network, information risk management is challenging and various factors must be considered. This article introduces a trust-based approach to facilitate supply chain participants to perform effective risk management. The major components of the propos...

  4. Cost-effectiveness and harm-benefit analyses of risk-based screening strategies for breast cancer.

    Directory of Open Access Journals (Sweden)

    Ester Vilaprinyo

    Full Text Available The one-size-fits-all paradigm in organized screening of breast cancer is shifting towards a personalized approach. The present study has two objectives: 1 To perform an economic evaluation and to assess the harm-benefit ratios of screening strategies that vary in their intensity and interval ages based on breast cancer risk; and 2 To estimate the gain in terms of cost and harm reductions using risk-based screening with respect to the usual practice. We used a probabilistic model and input data from Spanish population registries and screening programs, as well as from clinical studies, to estimate the benefit, harm, and costs over time of 2,624 screening strategies, uniform or risk-based. We defined four risk groups, low, moderate-low, moderate-high and high, based on breast density, family history of breast cancer and personal history of breast biopsy. The risk-based strategies were obtained combining the exam periodicity (annual, biennial, triennial and quinquennial, the starting ages (40, 45 and 50 years and the ending ages (69 and 74 years in the four risk groups. Incremental cost-effectiveness and harm-benefit ratios were used to select the optimal strategies. Compared to risk-based strategies, the uniform ones result in a much lower benefit for a specific cost. Reductions close to 10% in costs and higher than 20% in false-positive results and overdiagnosed cases were obtained for risk-based strategies. Optimal screening is characterized by quinquennial or triennial periodicities for the low or moderate risk-groups and annual periodicity for the high-risk group. Risk-based strategies can reduce harm and costs. It is necessary to develop accurate measures of individual risk and to work on how to implement risk-based screening strategies.

  5. Project Scheduling Based on Risk of Gas Transmission Pipe

    Science.gov (United States)

    Silvianita; Nurbaity, A.; Mulyadi, Y.; Suntoyo; Chamelia, D. M.

    2018-03-01

    The planning of a project has a time limit on which must be completed before or right at a predetermined time. Thus, in a project planning, it is necessary to have scheduling management that is useful for completing a project to achieve maximum results by considering the constraints that will exists. Scheduling management is undertaken to deal with uncertainties and negative impacts of time and cost in project completion. This paper explains about scheduling management in gas transmission pipeline project Gresik-Semarang to find out which scheduling plan is most effectively used in accordance with its risk value. Scheduling management in this paper is assissted by Microsoft Project software to find the critical path of existing project scheduling planning data. Critical path is the longest scheduling path with the fastest completion time. The result is found a critical path on project scheduling with completion time is 152 days. Furthermore, the calculation of risk is done by using House of Risk (HOR) method and it is found that the critical path has a share of 40.98 percent of all causes of the occurence of risk events that will be experienced.

  6. Determinants of self-perceived risk of HIV infection: population-based observations in Zambia

    OpenAIRE

    Mwangala, Sheila Monde

    2008-01-01

    Background Perception of risk of HIV infection has been suggested to be an important area of study as it can be an assumed to be an indicator of one’s understanding of susceptibility to HIV infection and a precursor to behavioral change, which could determine future decision making regarding risk taking. Studies that have examined perception of HIV risk and its determinants still remain limited. Zambia is among the worst affected countries by the HIV pandemic in the sub-Sahara African r...

  7. Flexible transfer limits in an open power market - Congestion versus risk of interruption

    Energy Technology Data Exchange (ETDEWEB)

    Warland, Geir

    1999-07-01

    Traditionally, power systems have been operated by deterministic criteria which tend to provide conservative security limits and will be inflexible and insensitive to changes in outage probabilities or market demands in a deregulated power system. This thesis introduces a new approach to power system operation in which the determination of operating limits for critical transmission lines or corridors is presented as a multiobjective decision problem, including risk assessment. Two objectives are included: (1) minimization of operating cost and (2) obtaining a secure operating level. The operating costs included are congestion costs, interruption costs and the costs of corrective or preventive actions to enhance security. In modelling uncertainties, a fuzzy model for the amount of load lost due to outages is presented. It includes the subjective uncertainty in the assessment of the amount of load lost, considering weather dependency of outage probabilities. There are four main conclusions: (1) The approach is flexible and sensitive to changes in outage probabilities and market demand, (2) A recommended solution will depend on system operator preference and expert opinion, (3) The approach includes the deterministic N-1 criterion as a special case, (4) The regret measure may in some difficult cases lead to indecision between solutions. 84 refs., 71 figs., 2 tabs.

  8. Flexible transfer limits in an open power market - Congestion versus risk of interruption

    International Nuclear Information System (INIS)

    Warland, Geir

    1999-01-01

    Traditionally, power systems have been operated by deterministic criteria which tend to provide conservative security limits and will be inflexible and insensitive to changes in outage probabilities or market demands in a deregulated power system. This thesis introduces a new approach to power system operation in which the determination of operating limits for critical transmission lines or corridors is presented as a multiobjective decision problem, including risk assessment. Two objectives are included: (1) minimization of operating cost and (2) obtaining a secure operating level. The operating costs included are congestion costs, interruption costs and the costs of corrective or preventive actions to enhance security. In modelling uncertainties, a fuzzy model for the amount of load lost due to outages is presented. It includes the subjective uncertainty in the assessment of the amount of load lost, considering weather dependency of outage probabilities. There are four main conclusions: (1) The approach is flexible and sensitive to changes in outage probabilities and market demand, (2) A recommended solution will depend on system operator preference and expert opinion, (3) The approach includes the deterministic N-1 criterion as a special case, (4) The regret measure may in some difficult cases lead to indecision between solutions. 84 refs., 71 figs., 2 tabs

  9. Sensitivity of Risk-Based Maintenance Planning of Offshore Wind Turbine Farms

    DEFF Research Database (Denmark)

    Ambühl, Simon; Sørensen, John Dalsgaard

    2017-01-01

    Inspection and maintenance expenses cover a considerable part of the cost of energy from offshore wind turbines. Risk-based maintenance planning approaches are a powerful tool to optimize maintenance and inspection actions and decrease the total maintenance expenses. Risk-based planning is based...... on many input parameters, which are in reality often not completely known. This paper will assess the cost impact of this incomplete knowledge based on a case study following risk-based maintenance planning. The sensitivity study focuses on weather forecast uncertainties, incomplete knowledge about...... the needed repair time on the site as well as uncertainties about the operational range of the boat and helicopter used to access the broken wind turbine. The cost saving potential is estimated by running Crude Monte Carlo simulations. Furthermore, corrective and preventive (scheduled and condition...

  10. Tourism at Risk: Failures and Dichotomies of Risk Perception Theory in Tourism (Opinion Piece

    Directory of Open Access Journals (Sweden)

    Maximiliano E. KORSTANJE

    2017-12-01

    Full Text Available The turn of the century has brought a lot of radical shifts and risks for tourism industry, which ranged from terrorism to lethal virus outbreaks. Henceforth risk perception theory, which was formulated in psychology, was re-appropriated by policy makers and tourism-related scholars. However, from its inception this conceptual corpus was based on the economic-centred paradigm. This piece discusses critically the main limitations of risk perception theory and the rise of a new discipline, post disaster marketing, in view of the caveats and speculative assumption of “the precautionary principle”.

  11. Performance-Based Risk-Sharing Arrangements: U.S. Payer Experience.

    Science.gov (United States)

    Goble, Joseph A; Ung, Brian; van Boemmel-Wegmann, Sascha; Navarro, Robert P; Parece, Andrew

    2017-10-01

    As a result of global concern about rising drug costs, many U.S. payers and European agencies such as the National Health Service have partnered with pharmaceutical companies in performance-based risk-sharing arrangements (PBRSAs) by which manufacturers share financial risk with health care purchasing entities and authorities. However, PBRSAs present many administrative and legal challenges that have minimized successful contract experiences in the United States. To (a) identify drug and disease characteristics and contract components that contribute to successful PBRSA experiences and the primary barriers to PBRSA execution and (b) explore solutions to facilitate contract negotiation and execution. A 37-item, web-based survey instrument (Qualtrics), approximately 20 minutes in duration, was open during July and August 2016. The survey was emailed to 90 pharmacy and medical directors of various health care organizations. Statistical analysis included the Kruskal-Wallis test and chi-square tests to examine differences among payer responses. Survey responses were anonymized and data were aggregated. Twenty-seven individuals completed the survey (30% completion rate). The majority of respondents worked for regional health plans (52%, n = 14), covering at least 1 million lives (63%, n = 17), with at least 7 years of managed care experience (81%, n = 22). A total of 51 PBRSAs were active among respondents at the time of the survey. Easily obtainable and evaluable drug data and medical data were the most important drug and disease attributes for successful PBRSAs, respectively. Pharmacy claims and patient demographic data were assessed as "very easy and inexpensive" to collect. Type and amount of manufacturer payment for drug outcome performance failure, endpoint measurement, and necessary clinical data for drug performance measurement were all critical factors for successful PBRSAs. Standardized contract templates and transparent contract financial risk evaluation and

  12. Differences conception prospective students teacher about limit of function based gender

    Science.gov (United States)

    Usman, Juniati, Dwi; Siswono, Tatag Yuli Eko

    2017-08-01

    Gender is one of the interesting topics and has continuity to be explored in mathematics education research. The purpose of this study to explore difference on conceptions of students teaching program by gender. It specialized on conception of understanding, representating, and mental images about limit function. This research conducting qualitative explorative method approach. The subject consisted of one man and one woman from the group of highly skilled student and has gone through semester V. Based on data that had been analyzed proved that male student has an understanding about limit function shared by explaining this material using illustrations, while female student explained it through verbal explanation. Due to representating aspect, it revealed that both of male and female students have similarity such as using verbal explanation, graphs, symbols, and tables to representating about limit function. Analyzing Mental image aspect, researcher got that male student using word "to converge" to explained about limit function, while female student using word "to approach". So, there are differences conceptions about limit function between male and female student.

  13. Credit risk evaluation based on social media.

    Science.gov (United States)

    Yang, Yang; Gu, Jing; Zhou, Zongfang

    2016-07-01

    Social media has been playing an increasingly important role in the sharing of individuals' opinions on many financial issues, including credit risk in investment decisions. This paper analyzes whether these opinions, which are transmitted through social media, can accurately predict enterprises' future credit risk. We consider financial statements oriented evaluation results based on logit and probit approaches as the benchmarks. We then conduct textual analysis to retrieve both posts and their corresponding commentaries published on two of the most popular social media platforms for financial investors in China. Professional advice from financial analysts is also investigated in this paper. We surprisingly find that the opinions extracted from both posts and commentaries surpass opinions of analysts in terms of credit risk prediction. Copyright © 2015 Elsevier Inc. All rights reserved.

  14. The principles of dose limitation in radiation protection

    International Nuclear Information System (INIS)

    Kaul, A.

    1988-01-01

    The aim of radiation protection is to protect individuals, their offspring and the population as a whole against harmful effects from ionizing radiation and radioactive substances. Harmful effects may be either somatic, i.e. occurring in the exposed person himself/herself, or hereditary, i.e. occurring in the exposed person's offspring. Successful radiation protection involves (a) protective measures based on the results of research into the biological and biophysical effects of radiation and (b) ensuring that activities necessitating exposure are justified and that the degree of exposure is minimal. This benefit/risk principle ceases to apply if a radiation source is out of control, since the main aim is then to introduce risk limitation measures, provided that these are of positive net benefit to the individual and the population as a whole. This paper discusses the principles of dose limitation as a function of exposure conditions, i.e. controlled or uncontrolled exposure to a source of radiation

  15. To manage the ionizing radiations risks

    International Nuclear Information System (INIS)

    Metivier, H.; Romerio, F.

    2000-01-01

    Mister Romerio's work tackles the problem of controversy revealed by the experts in the field of estimation and management of ionizing radiations risks. The author describes the three paradigms at the base of the debate: the relationship without threshold (typified by the ICRP and its adepts), these ones that think that low doses risks are overestimated ( Medicine Academia for example) or that ones that believe that dose limits are too severe and induce unwarranted costs; then that ones that think that these risks are under-estimated and limits should be more reduced, even stop these practices that lead to public exposure to ionizing radiations. The author details the uncertainties about the risk estimations, refreshes the knowledge in radiation protection with the explanations of the different paradigms. At the end a table summarize the positions of the three paradigms

  16. Experiences from occupational exposure limits set on aerosols containing allergenic proteins

    DEFF Research Database (Denmark)

    Nielsen, Gunnar; Larsen, Søren; Hansen, Jitka S

    2012-01-01

    Occupational exposure limits (OELs) together with determined airborne exposures are used in risk assessment based managements of occupational exposures to prevent occupational diseases. In most countries, OELs have only been set for few protein-containing aerosols causing IgE-mediated allergies. ...... is available for setting OELs for proteins and protein-containing aerosols where the critical effect is IgE sensitization and IgE-mediated airway diseases.......Occupational exposure limits (OELs) together with determined airborne exposures are used in risk assessment based managements of occupational exposures to prevent occupational diseases. In most countries, OELs have only been set for few protein-containing aerosols causing IgE-mediated allergies...... for setting OELs. Our aim is to analyse prerequisites for setting OELs for the allergenic protein-containing aerosols. Opposite to the key effect of toxicological reactions, two thresholds, one for the sensitization phase and one for elicitation of IgE-mediated symptoms in sensitized individuals, are used...

  17. Managing Risks in Distributed Software Projects: An Integrative Framework

    DEFF Research Database (Denmark)

    Persson, John Stouby; Mathiassen, Lars; Boeg, Jesper

    2009-01-01

    techniques into an integrative framework for managing risks in distributed contexts. Subsequent implementation of a Web-based tool helped us refine the framework based on empirical evaluation of its practical usefulness.We conclude by discussing implications for both research and practice.......Software projects are increasingly geographically distributed with limited face-to-face interaction between participants. These projects face particular challenges that need carefulmanagerial attention. While risk management has been adopted with success to address other challenges within software...... development, there are currently no frameworks available for managing risks related to geographical distribution. On this background, we systematically review the literature on geographically distributed software projects. Based on the review, we synthesize what we know about risks and risk resolution...

  18. Measuring the coupled risks: A copula-based CVaR model

    Science.gov (United States)

    He, Xubiao; Gong, Pu

    2009-01-01

    Integrated risk management for financial institutions requires an approach for aggregating risk types (such as market and credit) whose distributional shapes vary considerably. The financial institutions often ignore risks' coupling influence so as to underestimate the financial risks. We constructed a copula-based Conditional Value-at-Risk (CVaR) model for market and credit risks. This technique allows us to incorporate realistic marginal distributions that capture essential empirical features of these risks, such as skewness and fat-tails while allowing for a rich dependence structure. Finally, the numerical simulation method is used to implement the model. Our results indicate that the coupled risks for the listed company's stock maybe are undervalued if credit risk is ignored, especially for the listed company with bad credit quality.

  19. Benefits and Limitations of Real Options Analysis for the Practice of River Flood Risk Management

    Science.gov (United States)

    Kind, Jarl M.; Baayen, Jorn H.; Botzen, W. J. Wouter

    2018-04-01

    Decisions on long-lived flood risk management (FRM) investments are complex because the future is uncertain. Flexibility and robustness can be used to deal with future uncertainty. Real options analysis (ROA) provides a welfare-economics framework to design and evaluate robust and flexible FRM strategies under risk or uncertainty. Although its potential benefits are large, ROA is hardly used in todays' FRM practice. In this paper, we investigate benefits and limitations of a ROA, by applying it to a realistic FRM case study for an entire river branch. We illustrate how ROA identifies optimal short-term investments and values future options. We develop robust dike investment strategies and value the flexibility offered by additional room for the river measures. We benchmark the results of ROA against those of a standard cost-benefit analysis and show ROA's potential policy implications. The ROA for a realistic case requires a high level of geographical detail, a large ensemble of scenarios, and the inclusion of stakeholders' preferences. We found several limitations of applying the ROA. It is complex. In particular, relevant sources of uncertainty need to be recognized, quantified, integrated, and discretized in scenarios, requiring subjective choices and expert judgment. Decision trees have to be generated and stakeholders' preferences have to be translated into decision rules. On basis of this study, we give general recommendations to use high discharge scenarios for the design of measures with high fixed costs and few alternatives. Lower scenarios may be used when alternatives offer future flexibility.

  20. Risk based In Vitro Performance Assessment of Extended Release Abuse Deterrent Formulations

    Science.gov (United States)

    Xu, Xiaoming; Gupta, Abhay; Al-Ghabeish, Manar; Calderon, Silvia N.; Khan, Mansoor A.

    2016-01-01

    High strength extended release opioid products, which are indispensable tools in the management of pain, are associated with serious risks of unintentional and potentially fatal overdose, as well as of misuse and abuse that might lead to addiction. The issue of drug abuse becomes increasingly prominent when the dosage forms can be readily manipulated to release a high amount of opioid or to extract the drug in certain products or solvents. One approach to deter opioid drug abuse is by providing novel abuse deterrent formulations (ADF), with properties that may be viewed as barriers to abuse of the product. However, unlike regular extended release formulations, assessment of ADF technologies are challenging, in part due to the great variety of formulation designs available to achieve deterrence of abuse by oral, parenteral, nasal and respiratory routes. With limited prior history or literature information, and lack of compendial standards, evaluation and regulatory approval of these novel drug products become increasingly difficult. The present article describes a risk-based standardized in-vitro approach that can be utilized in general evaluation of abuse deterrent features for all ADF products. PMID:26784976

  1. Advances in probabilistic risk analysis

    International Nuclear Information System (INIS)

    Hardung von Hardung, H.

    1982-01-01

    Probabilistic risk analysis can now look back upon almost a quarter century of intensive development. The early studies, whose methods and results are still referred to occasionally, however, only permitted rough estimates to be made of the probabilities of recognizable accident scenarios, failing to provide a method which could have served as a reference base in calculating the overall risk associated with nuclear power plants. The first truly solid attempt was the Rasmussen Study and, partly based on it, the German Risk Study. In those studies, probabilistic risk analysis has been given a much more precise basis. However, new methodologies have been developed in the meantime, which allow much more informative risk studies to be carried out. They have been found to be valuable tools for management decisions with respect to backfitting, reinforcement and risk limitation. Today they are mainly applied by specialized private consultants and have already found widespread application especially in the USA. (orig.) [de

  2. Investigation of established genetic risk variants for glioma in prediagnostic samples from a population-based nested case-control study.

    Science.gov (United States)

    Wibom, Carl; Späth, Florentin; Dahlin, Anna M; Langseth, Hilde; Hovig, Eivind; Rajaraman, Preetha; Johannesen, Tom Børge; Andersson, Ulrika; Melin, Beatrice

    2015-05-01

    Although glioma etiology is poorly understood in general, growing evidence indicates a genetic component. Four large genome-wide association studies (GWAS) have linked common genetic variants with an increased glioma risk. However, to date, these studies are based largely on a case-control design, where cases have been recruited at the time of or after diagnosis. They may therefore suffer from a degree of survival bias, introduced when rapidly fatal cases are not included. To confirm glioma risk variants in a prospective setting, we have analyzed 11 previously identified risk variants in a set of prediagnostic serum samples with 598 cases and 595 matched controls. Serum samples were acquired from The Janus Serum Bank, a Norwegian population-based biobank reserved for cancer research. We confirmed the association with glioma risk for variants within five genomic regions: 8q24.21 (CCDC26), 9p21.3 (CDKN2B-AS1), 11q23.3 (PHLDB1), 17p13.1 (TP53), and 20q13.33 (RTEL1). However, previously identified risk variants within the 7p11.2 (EGFR) region were not confirmed by this study. Our results indicate that the risk variants that were confirmed by this study are truly associated with glioma risk and may, consequently, affect gliomagenesis. Though the lack of positive confirmation of EGFR risk variants may be attributable to relatively limited statistical power, it nevertheless raises the question whether they truly are risk variants or markers for glioma prognosis. Our findings indicate the need for further studies to clarify the role of glioma risk loci with respect to prolonged survival versus etiology. ©2015 American Association for Cancer Research.

  3. Risk-based emergency decision support

    International Nuclear Information System (INIS)

    Koerte, Jens

    2003-01-01

    In the present paper we discuss how to assist critical decisions taken under complex, contingent circumstances, with a high degree of uncertainty and short time frames. In such sharp-end decision regimes, standard rule-based decision support systems do not capture the complexity of the situation. At the same time, traditional risk analysis is of little use due to variability in the specific circumstances. How then, can an organisation provide assistance to, e.g. pilots in dealing with such emergencies? A method called 'contingent risk and decision analysis' is presented, to provide decision support for decisions under variable circumstances and short available time scales. The method consists of nine steps of definition, modelling, analysis and criteria definition to be performed 'off-line' by analysts, and procedure generation to transform the analysis result into an operational decision aid. Examples of pilots' decisions in response to sudden vibration in offshore helicopter transport method are used to illustrate the approach

  4. Time-based collision risk modeling for air traffic management

    Science.gov (United States)

    Bell, Alan E.

    Since the emergence of commercial aviation in the early part of last century, economic forces have driven a steadily increasing demand for air transportation. Increasing density of aircraft operating in a finite volume of airspace is accompanied by a corresponding increase in the risk of collision, and in response to a growing number of incidents and accidents involving collisions between aircraft, governments worldwide have developed air traffic control systems and procedures to mitigate this risk. The objective of any collision risk management system is to project conflicts and provide operators with sufficient opportunity to recognize potential collisions and take necessary actions to avoid them. It is therefore the assertion of this research that the currency of collision risk management is time. Future Air Traffic Management Systems are being designed around the foundational principle of four dimensional trajectory based operations, a method that replaces legacy first-come, first-served sequencing priorities with time-based reservations throughout the airspace system. This research will demonstrate that if aircraft are to be sequenced in four dimensions, they must also be separated in four dimensions. In order to separate aircraft in four dimensions, time must emerge as the primary tool by which air traffic is managed. A functional relationship exists between the time-based performance of aircraft, the interval between aircraft scheduled to cross some three dimensional point in space, and the risk of collision. This research models that relationship and presents two key findings. First, a method is developed by which the ability of an aircraft to meet a required time of arrival may be expressed as a robust standard for both industry and operations. Second, a method by which airspace system capacity may be increased while maintaining an acceptable level of collision risk is presented and demonstrated for the purpose of formulating recommendations for procedures

  5. Enhancing the effectiveness of IST through risk-based techniques

    Energy Technology Data Exchange (ETDEWEB)

    Floyd, S.D.

    1996-12-01

    Current IST requirements were developed mainly through deterministic-based methods. While this approach has resulted in an adequate level of safety and reliability for pumps and valves, insights from probabilistic safety assessments suggest a better safety focus can be achieved at lower costs. That is, some high safety impact pumps and valves are currently not tested under the IST program and should be added, while low safety impact valves could be tested at significantly greater intervals than allowed by the current IST program. The nuclear utility industry, through the Nuclear Energy Institute (NEI), has developed a draft guideline for applying risk-based techniques to focus testing on those pumps and valves with a high safety impact while reducing test frequencies on low safety impact pumps and valves. The guideline is being validated through an industry pilot application program that is being reviewed by the U.S. Nuclear Regulatory Commission. NEI and the ASME maintain a dialogue on the two groups` activities related to risk-based IST. The presenter will provide an overview of the NEI guideline, discuss the methodological approach for applying risk-based technology to IST and provide the status of the industry pilot plant effort.

  6. Risk management through dynamic technical specifications

    International Nuclear Information System (INIS)

    Klopp, George T.; Petersen, Thomas A.

    2004-01-01

    The wide deployment of plant specific probabilistic risk assessments for nuclear power plants has provided the means to effect a fresh risk management perspective and a fresh, risk based, regulatory outlook on nuclear power. There has been a great deal of conversation on risk based regulation within the U. S. nuclear power industry but, curiously, very little on effective risk management. This paper proposes a means to link the two subjects through the plant Technical Specifications. A revised concept for Technical Specifications is suggested which is based on deterministic analyses and probabilistic risk assessments for each plant. The revised Technical Specifications would consider, on a real-time basis, the exact state of the plant in terms of the status of key components and systems. It would depict current plant risk levels and compare those levels to the desired and limiting (alert/action) levels. It would advise the plant operator on the risk impact of proposed actions through a simple query system and illustrate the impact of such actions on plant status relative to designated risk values. The basis for the proposed approach lies in realistic deterministic plant analyses and probabilistic risk assessment (PRA) deployment tools being developed, in parallel, by a number of parties in the U.S. today. These PRAs are based primarily on the existing plant responses to Generic Letter 88-20, 'Individual Plant Examinations' (IPEs). Each of these tools allows the plant operator to input, on a real-time basis, the status of key equipment and systems. The tools then provide explicit illustrations of dependency effects; updated, 'real-time' risk status indications such as core damage frequency; and, in some cases, allow the operator to assess the risk impact of removing from service selected components for maintenance or testing. These systems generally operate on personal computers and provide nearly instantaneous responses to plant queries. Moving from these tools to

  7. Methods of Optimisation of the Structure of the Dealing Bank with a Limited Base of Counter-Agents

    Directory of Open Access Journals (Sweden)

    Novak Sergіy M.

    2013-11-01

    Full Text Available The article considers methods of assessment of optimal parameters of the dealing bank service with a limited base of counter-agents. The methods are based on the mathematical model of micro-structure of the inter-bank currency market. The key parameters of the infrastructure of the dealing service within the framework of the model are: number of authorised traders, contingent of counter-agents, quotation policy, main parameters of the currency market – spread and volatility of quotations and the resulting indicators of efficiency of the dealing service – profit and probability of breakeven operation. The methods allow identification of optimal parameters of the infrastructure of the dealing bank service based on indicators of dynamics of currency risks and market environment of the bank. On the basis of the developed mathematical model the article develops methods of planning calculations of parameters of the infrastructure of the dealing bank service, which are required for ensuring a necessary level of efficiency with set parameters of the currency market. Application of the said methods gives a possibility to assess indicators of operation of the bank’s front office depending on its scale.

  8. Integrating Household Risk Mitigation Behavior in Flood Risk Analysis: An Agent-Based Model Approach.

    Science.gov (United States)

    Haer, Toon; Botzen, W J Wouter; de Moel, Hans; Aerts, Jeroen C J H

    2017-10-01

    Recent studies showed that climate change and socioeconomic trends are expected to increase flood risks in many regions. However, in these studies, human behavior is commonly assumed to be constant, which neglects interaction and feedback loops between human and environmental systems. This neglect of human adaptation leads to a misrepresentation of flood risk. This article presents an agent-based model that incorporates human decision making in flood risk analysis. In particular, household investments in loss-reducing measures are examined under three economic decision models: (1) expected utility theory, which is the traditional economic model of rational agents; (2) prospect theory, which takes account of bounded rationality; and (3) a prospect theory model, which accounts for changing risk perceptions and social interactions through a process of Bayesian updating. We show that neglecting human behavior in flood risk assessment studies can result in a considerable misestimation of future flood risk, which is in our case study an overestimation of a factor two. Furthermore, we show how behavior models can support flood risk analysis under different behavioral assumptions, illustrating the need to include the dynamic adaptive human behavior of, for instance, households, insurers, and governments. The method presented here provides a solid basis for exploring human behavior and the resulting flood risk with respect to low-probability/high-impact risks. © 2016 The Authors Risk Analysis published by Wiley Periodicals, Inc. on behalf of Society for Risk Analysis.

  9. Limited Commitment Models of the Labour Market

    OpenAIRE

    Jonathan Thomas; Tim Worrall

    2007-01-01

    We present an overview of models of long-term self-enforcing labour con- tracts in which risk-sharing is the dominant motive for contractual solutions. A base model is developed which is sufficiently general to encompass the two-agent problem central to most of the literature, including variable hours. We consider two-sided limited commitment and look at its implications for aggregate labour market variables. We consider the implications for empirical testing and the available empirical evide...

  10. A perspective of PC-based probabilistic risk assessment

    International Nuclear Information System (INIS)

    Sattison, M.B.; Rasmuson, D.M.; Robinson, R.C.; Russell, K.D.; Van Siclen, V.S.

    1987-01-01

    Probabilistic risk assessment (PRA) information has been under-utilized in the past due to the large effort required to input the PRA data and the large expense of the computers needed to run PRA codes. The microcomputer-based Integrated Reliability and Risk Analysis System (IRRAS) and the System Analysis and Risk Assessment (SARA) System, under development at the Idaho National Engineering Laboratory, have greatly enhanced the ability of managers to use PRA techniques in their decision-making. IRRAS is a tool that allows an analyst to create, modify, update, and reanalyze a plant PRA to keep the risk assessment current with the plant's configuration and operation. The SARA system is used to perform sensitivity studies on the results of a PRA. This type of analysis can be used to evaluate proposed changes to a plant or its operation. The success of these two software projects demonstrate that risk information can be made readily available to those that need it. This is the first step in the development of a true risk management capability

  11. SADA: Ecological Risk Based Decision Support System for Selective Remediation

    Science.gov (United States)

    Spatial Analysis and Decision Assistance (SADA) is freeware that implements terrestrial ecological risk assessment and yields a selective remediation design using its integral geographical information system, based on ecological and risk assessment inputs. Selective remediation ...

  12. [Physical process based risk assessment of groundwater pollution in the mining area].

    Science.gov (United States)

    Sun, Fa-Sheng; Cheng, Pin; Zhang, Bo

    2014-04-01

    Case studies of groundwater pollution risk assessment at home and abroad generally start from groundwater vulnerability, without considering the influence of characteristic pollutants on the consequences of pollution too much. Vulnerability is the natural sensitivity of the environment to pollutants. Risk assessment of groundwater pollution should reflect the movement and distribution of pollutants in groundwater. In order to improve the risk assessment theory and method of groundwater pollution, a physical process based risk assessment methodology for groundwater pollution was proposed in a mining area. According to the sensitivity of the economic and social conditions and the possible distribution of pollutants in the future, the spatial distribution of risk levels in aquifer was ranged before hand, and the pollutant source intensity corresponding to each risk level was deduced accordingly. By taking it as the criterion for the classification of groundwater pollution risk assessment, the groundwater pollution risk in the mining area was evaluated by simulating the migration of pollutants in the vadose zone and aquifer. The result show that the risk assessment method of groundwater pollution based on physical process can give the concentration distribution of pollutants and the risk level in the spatial and temporal. For single punctuate polluted area, it gives detailed risk characterization, which is better than the risk assessment method that based on aquifer intrinsic vulnerability index, and it is applicable to the risk assessment of existing polluted sites, optimizing the future sites and providing design parameters for the site construction.

  13. FIRE SAFETY IN NUCLEAR POWER PLANTS: A RISK-INFORMED AND PERFORMANCE-BASED APPROACH

    International Nuclear Information System (INIS)

    AZARM, M.A.; TRAVIS, R.J.

    1999-01-01

    The consideration of risk in regulatory decision-making has long been a part of NRC's policy and practice. Initially, these considerations were qualitative and were based on risk insights. The early regulations relied on good practices, past insights, and accepted standards. As a result, most NRC regulations were prescriptive and were applied uniformly to all areas within the regulatory scope. Risk technology is changing regulations by prioritizing the areas within regulatory scope based on risk, thereby focusing on the risk-important areas. Performance technology, on the other hand, is changing the regulations by allowing requirements to be adjusted based on the specific performance expected and manifested, rather than a prior prescriptive requirement. Consistent with the objectives of risk-informed and performance-based regulatory requirements, BNL evaluated the feasibility of applying risk- and performance-technologies to modifying NRC's current regulations on fire protection for nuclear power plants. This feasibility study entailed several case studies (trial applications). This paper describes the results of two of them. Besides the case studies, the paper discusses an overall evaluation of methodologies for fire-risk analysis to support the risk-informed regulation. It identifies some current shortcomings and proposes some near-term solutions

  14. Risk-based systems analysis for emerging technologies: Applications of a technology risk assessment model to public decision making

    International Nuclear Information System (INIS)

    Quadrel, M.J.; Fowler, K.M.; Cameron, R.; Treat, R.J.; McCormack, W.D.; Cruse, J.

    1995-01-01

    The risk-based systems analysis model was designed to establish funding priorities among competing technologies for tank waste remediation. The model addresses a gap in the Department of Energy's (DOE's) ''toolkit'' for establishing funding priorities among emerging technologies by providing disciplined risk and cost assessments of candidate technologies within the context of a complete remediation system. The model is comprised of a risk and cost assessment and a decision interface. The former assesses the potential reductions in risk and cost offered by new technology relative to the baseline risk and cost of an entire system. The latter places this critical information in context of other values articulated by decision makers and stakeholders in the DOE system. The risk assessment portion of the model is demonstrated for two candidate technologies for tank waste retrieval (arm-based mechanical retrieval -- the ''long reach arm'') and subsurface barriers (close-coupled chemical barriers). Relative changes from the base case in cost and risk are presented for these two technologies to illustrate how the model works. The model and associated software build on previous work performed for DOE's Office of Technology Development and the former Underground Storage Tank Integrated Demonstration, and complement a decision making tool presented at Waste Management 1994 for integrating technical judgements and non-technical (stakeholder) values when making technology funding decisions

  15. System risk evolution analysis and risk critical event identification based on event sequence diagram

    International Nuclear Information System (INIS)

    Luo, Pengcheng; Hu, Yang

    2013-01-01

    During system operation, the environmental, operational and usage conditions are time-varying, which causes the fluctuations of the system state variables (SSVs). These fluctuations change the accidents’ probabilities and then result in the system risk evolution (SRE). This inherent relation makes it feasible to realize risk control by monitoring the SSVs in real time, herein, the quantitative analysis of SRE is essential. Besides, some events in the process of SRE are critical to system risk, because they act like the “demarcative points” of safety and accident, and this characteristic makes each of them a key point of risk control. Therefore, analysis of SRE and identification of risk critical events (RCEs) are remarkably meaningful to ensure the system to operate safely. In this context, an event sequence diagram (ESD) based method of SRE analysis and the related Monte Carlo solution are presented; RCE and risk sensitive variable (RSV) are defined, and the corresponding identification methods are also proposed. Finally, the proposed approaches are exemplified with an accident scenario of an aircraft getting into the icing region

  16. Bayesian risk-based decision method for model validation under uncertainty

    International Nuclear Information System (INIS)

    Jiang Xiaomo; Mahadevan, Sankaran

    2007-01-01

    This paper develops a decision-making methodology for computational model validation, considering the risk of using the current model, data support for the current model, and cost of acquiring new information to improve the model. A Bayesian decision theory-based method is developed for this purpose, using a likelihood ratio as the validation metric for model assessment. An expected risk or cost function is defined as a function of the decision costs, and the likelihood and prior of each hypothesis. The risk is minimized through correctly assigning experimental data to two decision regions based on the comparison of the likelihood ratio with a decision threshold. A Bayesian validation metric is derived based on the risk minimization criterion. Two types of validation tests are considered: pass/fail tests and system response value measurement tests. The methodology is illustrated for the validation of reliability prediction models in a tension bar and an engine blade subjected to high cycle fatigue. The proposed method can effectively integrate optimal experimental design into model validation to simultaneously reduce the cost and improve the accuracy of reliability model assessment

  17. Intensity ramp-up: 2011 experience - Limitations, mitigation, risks, strategy, pushing it in 2012, 1380 in 3 weeks?

    CERN Document Server

    Zerlauth, M; Wenninger, J

    2012-01-01

    This paper will discuss the experience with ramping up the beam intensities in the early days of the 2011 run and after the subsequent technical stops. Weak points and limitations are being identified and their possible mitigations evaluated. In view of the risks and drawbacks of a too aggressive approach, possible improvements of the applied strategy whilst maintaining the required validation points for the various equipment and machine protection systems (MPS) are being discussed.

  18. Towards risk-based structural integrity methods for PWRs

    International Nuclear Information System (INIS)

    Chapman, O.J.V.; Lloyd, R.B.

    1992-01-01

    This paper describes the development of risk-based structural integrity assurance methods and their application to Pressurized Water Reactor (PWR) plant. In-service inspection is introduced as a way of reducing the failure probability of high risk sites and the latter are identified using reliability analysis; the extent and interval of inspection can also be optimized. The methodology is illustrated by reference to the aspect of reliability of weldments in PWR systems. (author)

  19. A clustering approach to segmenting users of internet-based risk calculators.

    Science.gov (United States)

    Harle, C A; Downs, J S; Padman, R

    2011-01-01

    Risk calculators are widely available Internet applications that deliver quantitative health risk estimates to consumers. Although these tools are known to have varying effects on risk perceptions, little is known about who will be more likely to accept objective risk estimates. To identify clusters of online health consumers that help explain variation in individual improvement in risk perceptions from web-based quantitative disease risk information. A secondary analysis was performed on data collected in a field experiment that measured people's pre-diabetes risk perceptions before and after visiting a realistic health promotion website that provided quantitative risk information. K-means clustering was performed on numerous candidate variable sets, and the different segmentations were evaluated based on between-cluster variation in risk perception improvement. Variation in responses to risk information was best explained by clustering on pre-intervention absolute pre-diabetes risk perceptions and an objective estimate of personal risk. Members of a high-risk overestimater cluster showed large improvements in their risk perceptions, but clusters of both moderate-risk and high-risk underestimaters were much more muted in improving their optimistically biased perceptions. Cluster analysis provided a unique approach for segmenting health consumers and predicting their acceptance of quantitative disease risk information. These clusters suggest that health consumers were very responsive to good news, but tended not to incorporate bad news into their self-perceptions much. These findings help to quantify variation among online health consumers and may inform the targeted marketing of and improvements to risk communication tools on the Internet.

  20. Industrial risks

    International Nuclear Information System (INIS)

    Okrent, D.

    1981-01-01

    A brief look is taken at the status of progress, or the lack of it, towards a quantitative approach to the estimation and assessment of risk for several technologies in the United States. The increase of interest in the consideration of comparative risks in decision-making is also discussed. Finally, a recently proposed trial approach to quantitative safety goals for light-water nuclear power reactors is summarized. The approach is divided into two major tasks: the predominantly social and political task of setting safety criteria, and the technical task of estimating the risks and deciding whether the safety criteria have been met. The safety criteria include the following: limits on hazard states within the reactor; limits on risk to the individual; limits on societal risk; a cost-effectiveness criterion as low as reasonably achievable; a small element of risk aversion. (author)

  1. Demonstration of risk-based approaches to nuclear plant regulation

    International Nuclear Information System (INIS)

    Rahn, F.J.; Sursock, J.P.; Darling, S.S.; Oddo, J.M.

    1993-01-01

    This paper describes generic technical support EPRI is providing to the nuclear power industry relative to its recent initiatives in the area of risk-based regulations (RBR). A risk-based regulatory approach uses probabilistic risk assessment (PRA), or similar techniques, to allocate safety resources commensurate with the risk posed by nuclear plant operations. This approach will reduce O ampersand M costs, and also improve nuclear plant safety. In order to enhance industry, Nuclear Regulatory Commission (NRC) and public confidence in RBR, three things need to be shown: (1) manpower/resource savings are significant for both NRC and industry; (2) the process is doable in a reasonable amount of time; and (3) the process, if uniformly applied, results in demonstrably cheaper power and safer plants. In 1992, EPRI performed a qualitative study of the key RBR issues contributing to high O ampersand M costs. The results are given on Table 1. This study is being followed up by an in-depth quantitative cost/benefit study to focus technical work on producing guidelines/procedures for licensing submittals to NRC. The guidelines/procedures necessarily will be developed from successful demonstration projects such as the Fitzpatrick pilot plant study proposed by the New York Power Authority and other generic applications. This paper presents three examples: two motor operated valve projects performed by QUADREX Energy Services Corporation working with utilities in responding to NRC Generic Letter 89-10, and a third project working with Yankee Atomic Electric Company on service water systems at a plant in its service system. These demonstration projects aim to show the following: (1) the relative ease of putting together a technical case based on RBR concepts; (2) clarity in differentiating the various risk trade-offs, and in communicating overall reductions in risk with NRC; and (3) improved prioritization of NRC directives

  2. Scientists vs. Vesuvius: limits of volcanology

    Science.gov (United States)

    Carlino, Stefano; Somma, Renato

    2014-05-01

    Recently, Italian newspapers reported the statements of Japanese and American volcanologists which declared the high hazard related to the future occurrence of catastrophic eruption at Vesuvius. Is this a reliable picture from scientific point of view? The evaluation of volcanic hazard is based on a general statistical law for which the chances of an eruptive event increase when energy decreases. This law is constructed on the basis of empirical data. Thus, the possibility that a plinian-like eruption occurs, for each volcano, is rare and further reduced for worst-case scenario. However, empirical data are not supported by a robust scientific theory, experimentally verifiable through an exact forecast of a long-term eruption, both in time limits and in energy. Today, the lack of paradigms able to predict in a deterministic way such a complex phenomena, limit the field of the scientists that cannot go further evaluations of a purely probabilistic nature. From this point of view volcanology cannot be considered an hard quantitative Science. The declaration according to which Vesuvius, sooner or later, will produce a catastrophic eruption, yet apparently obvious if we consider the very high degree of urbanization, is not supported by any experimentally verifiable theory. Therefore, the statement according to which Vesuvius next eruptive event will be catastrophic is false. In probabilistic terms, it is actually the least possible scenario. Recognizing the cognitive limits in this research field means to encourage research itself towards the determination of more solid paradigms, in order to get more exact forecasts about such complex phenomena. The scientific compromise of defining risk scenarios, rather than deterministic evaluations about future eruptive events, precisely reflects the limits of research that have to be contemplated even by Civil Protection. Having considered these limits, every risk scenario, even the most conservative, will be ineffective in

  3. Estimating risk using bounding calculations and limited data

    International Nuclear Information System (INIS)

    COWLEY, W.L.

    1999-01-01

    This paper describes a methodology for estimating the potential risk to workers and the public from igniting organic solvents in any of the 177 underground waste storage tanks at the Hanford Site in southeastern Washington state. The Hanford Site is one of the U.S. Department of Energy's former production facilities for nuclear materials. The tanks contain mixed radioactive wastes. Risk is measured by calculating toxicological and radiological accident consequences and frequencies and comparing the results to established regulatory guidelines. Available sample data is insufficient to adequately characterize the waste and solvent, so a model that maximizes releases from the tanks (bounding case) is used. Maximizing releases (and thus consequences) is a standard technique used in safety analysis to compensate for lack of information. The model predicts bounding values of fire duration, the time at which the fire extinguishes because of lack of oxygen, and a pressure history of a fire in a tank. The model output is used to calculate mass and volume release rates of material from the tanks. The mass and volume release rates permit calculation of radiological and toxicological consequences. The resulting consequence calculations demonstrate that risk from an organic solvent fire in the tanks is within regulatory guidelines

  4. Non-cancer health risk assessment from exposure to cyanide by resident adults from the mining operations of Bogoso Gold Limited in Ghana.

    Science.gov (United States)

    Obiri, S; Dodoo, D K; Okai-Sam, F; Essumang, D K

    2006-07-01

    Cyanide is a very toxic chemical that is used to extract gold from its ores. Wastewaters from gold mining companies such as Bogoso Gold Limited (BGL) contain cyanide and other potentially toxic chemicals that have adverse effects on human beings and aquatic organisms. This study was conducted to evaluate the human health risk assessment from exposure to free cyanide via oral and dermal contact of surface/underground water by resident adults within the concession of Bogoso Gold Limited. The chronic non-cancer health risk from exposure to cyanide in River Bogo Upstream is 230 and 43 (by Central Tendency Exposure (CTE) parameters respectively). This means that approximately 230 and 43 resident adults are likely to suffer diseases related to cyanide intoxication via oral and dermal contact respectively. For chronic exposure to River Bogo Downstream by resident adults, the non-cancer health risks are: 0.031 and 0.57 via oral and dermal contact for CTE parameters respectively, which also means that, the non-cancer health risks associated with cyanide intoxication is negligible as the hazard index is less than 1.0 via oral and dermal contacts respectively. The results showed that health risk for acute exposure to cyanide by the resident adults is very high. Hence the residents attribute most of the unexplained deaths in the communities to accidental ingestion and dermal contact of cyanide water.

  5. Association of physical workload and leisure time physical activity with incident mobility limitations

    DEFF Research Database (Denmark)

    Mänty, M; Møller, A; Nilsson, C

    2014-01-01

    OBJECTIVES: To examine individual as well as joint associations of physical workload and leisure time physical activity with incident mobility limitations in initially well-functioning middle-aged workers. METHODS: This study is based on 6-year follow-up data of the Danish Longitudinal Study...... on Work, Unemployment and Health. Physical workload was reported at baseline and categorised as light, moderate or heavy. Baseline leisure time physical activity level was categorised as sedentary or active following the current recommendations on physical activity. Incidence of mobility limitations...... with higher workload regardless of level of leisure time physical activity, although the risks tended to be higher among those with sedentary leisure time compared with their active counterparts. All in all, the risk for onset of mobility limitations was highest among those with heavy workload combined...

  6. Sugary food and beverage consumption and epithelial ovarian cancer risk: a population-based case–control study

    Science.gov (United States)

    2013-01-01

    Background Ovarian cancer is the deadliest gynecologic cancer in the US. The consumption of refined sugars has increased dramatically over the past few decades, accounting for almost 15% of total energy intake. Yet, there is limited evidence on how sugar consumption affects ovarian cancer risk. Methods We evaluated ovarian cancer risk in relation to sugary foods and beverages, and total and added sugar intakes in a population-based case–control study. Cases were women with newly diagnosed epithelial ovarian cancer, older than 21 years, able to speak English or Spanish, and residents of six counties in New Jersey. Controls met same criteria as cases, but were ineligible if they had both ovaries removed. A total of 205 cases and 390 controls completed a phone interview, food frequency questionnaire, and self-recorded waist and hip measurements. Based on dietary data, we computed the number of servings of dessert foods, non-dessert foods, sugary drinks and total sugary foods and drinks for each participant. Total and added sugar intakes (grams/day) were also calculated. Multiple logistic regression models were used to estimate odds ratios and 95% confidence intervals for food and drink groups and total and added sugar intakes, while adjusting for major risk factors. Results We did not find evidence of an association between consumption of sugary foods and beverages and risk, although there was a suggestion of increased risk associated with sugary drink intake (servings per 1,000 kcal; OR=1.63, 95% CI: 0.94-2.83). Conclusions Overall, we found little indication that sugar intake played a major role on ovarian cancer development. PMID:23442818

  7. A new active portfolio risk management for an electricity retailer based on a drawdown risk preference

    International Nuclear Information System (INIS)

    Charwand, Mansour; Gitizadeh, Mohsen; Siano, Pierluigi

    2017-01-01

    This paper addresses the deciding under uncertainty of an electricity retailer in order to maximise its total expected rate of return. The developed methodology is based on the modelling of the stochastic evolution of zonal prices that seeks to manage a portfolio of different contracts. Retailer's load and the price at each zone are forecasted using the seasonal autoregressive integrated moving average (SARIMA) model and a clustering technique is used for scenario reduction. Supply sources include the pool, self-production facilities, forward and bilateral contracts. The risk of cost fluctuation due to uncertainties is explicitly modelled using the multi-scenario drawdown methodology. This risk function quantifies in aggregated format the frequency and magnitude of the portfolio drawdowns over planning horizon. In-sample and out-of-sample runs are performed for a portfolio allocation problem. Carried out experimental results on the basis of realistic data, show that imposing risk constraints improve the “real” performance of a portfolio management in out-of-sample runs. - Highlights: • A new drawdown-based method is introduced to retailer deciding under uncertainty. • This tool is used to assess the risk levels regarding retailer midterm strategies. • The methodology is based on the modeling of the stochastic evolution of zonal prices. • The risk function quantifies the frequency and magnitude of the portfolio drawdowns. • In-sample and out-of-sample runs are performed for a portfolio allocation problem.

  8. A risk-based review of Instrument Air systems at nuclear power plants

    International Nuclear Information System (INIS)

    DeMoss, G.; Lofgren, E.; Rothleder, B.; Villeran, M.; Ruger, C.

    1990-01-01

    The broad objective of this analysis was to provide risk-based information to help focus regulatory actions related to Instrument Air (IA) systems at operating nuclear power plants. We first created an extensive data base of summarized and characterized IA-related events that gave a qualitative indication of the nature and severity of these events. Additionally, this data base was used to calculate the frequencies of certain events, which were used in the risk analysis. The risk analysis consisted of reviewing published PRAs and NRC Accident Sequence Precursor reports for IA-initiated accident sequences, IA interactions with frontline systems, and IA-related risk significant events. Sensitivity calculations were performed when possible. Generically, IA was found to contribute less to total risk than many safety systems; however, specific design weaknesses in safety systems, non-safety systems, and the IA system were found to be significant in risk. 22 refs., 13 figs., 24 tabs

  9. Development of the Risk-Based Inspection Techniques and Pilot Plant Activities

    International Nuclear Information System (INIS)

    Phillips, J.H.

    1997-01-01

    Risk-based techniques have been developed for commercial nuclear power plants. System boundaries and success criteria is defined using the probabilistic risk analysis or probabilistic safety analysis developed to meet the individual plant evaluation. Final ranking of components is by a plant expert panel similar to the one developed for maintenance rule. Components are identified as being high risk-significant or low-risk significant. Maintenance and resources are focused on those components that have the highest risk-significance. The techniques have been developed and applied at a number of pilot plants. Results from the first risk-based inspection pilot plant indicates that safety due to pipe failure can be doubled while the inspection reduced to about 80% when compared with current inspection programs. The reduction in inspection reduces the person-rem exposure resulting in further increases in safety. These techniques have been documented in publication by the ASME CRTD

  10. Assessment of Home-Based Nigerian Engineers on Risk ...

    African Journals Online (AJOL)

    Assessment of Home-Based Nigerian Engineers on Risk Management Approach ... Journal of Applied Sciences and Environmental Management ... The Analysis of Variance (ANOVA) and Correlation methods were adopted for statistical ...

  11. Reviewing the economic efficiency of disaster risk management

    Science.gov (United States)

    Mechler, Reinhard

    2013-04-01

    There is a lot of rhetoric suggesting that disaster risk management (DRM) pays, yet surprisingly little in the way of hard facts. Cost-benefit analysis (CBA) is one major tool that can provide quantitative information about the prioritization of disaster risk management (DRM) (and climate adaptation) based on economic principles. Yet, on a global scale, there has been surprisingly little robust evidence on the economic efficiency and benefits of risk management measures. This review shows that for the limited evidence reported the economic case for DRM across a range of hazards is strong and that the benefits of investing in DRM outweigh the costs of doing so, on average, by about four times the cost in terms of avoided and reduced losses. Most studies using a CBA approach focus on structural DRM and most information has been made available on physical flood prevention. There have been some limited studies on preparedness and risk financing. The global evidence base is limited and estimates appear not very solid, and overall, in line with the conclusion of the recent IPCC SREX report, there is limited evidence and medium agreement across the literature. Some of the factors behind the limited robustness are inherent to CBA more widely: these challenges comprise the inability to price intangibles, evaluating strategies rather than single projects, difficulties in assessing softer rather than infrastructure-related options, choices regarding a proper discount rate, lack of accounting for the distribution of benefits and costs and difficulties with assessing nonmarket values such as those related to health, the environment, or public goods. Although techniques exist to address some of these challenges, they are not very likely to easily go away. Other challenges associated specifically with DRM, such as the need and difficulty to undertake risk -based analysis can be overcome, and there have been manuals and reports providing a way forward. In an age of austerity, cost

  12. Hanford study: a review of its limitations and controversial conclusions

    International Nuclear Information System (INIS)

    Gilbert, E.S.

    1984-10-01

    The Hanford data set has attracted attention primarily because of analyses conducted by Mancuso, Stewart, and Kneale (MSK). These investigators claim that the Hanford data provide evidence that our current estimates of cancer mortality resulting from radiation exposure are too low, and advocate replacing estimates based on populations exposed at relatively high doses (such as the Japanese atom bomb survivors) with estimates based on the Hanford data. In this paper, it is shown that the only evidence of association of radiation exposure and mortality provided by the Hanford data is a small excess of multiple myeloma, and that this data set is not adequate for reliable risk estimation. It is demonstrated that confidence limits for risk estimates are very wide, and that the data are not adequate to differentiate among models. The more recent MSK analyses, which claim to provide adequate models and risk estimates, are critiqued. 18 references, 1 table

  13. Sleep Disordered Breathing in Four Resource-Limited Settings in Peru: Prevalence, Risk Factors, and Association with Chronic Diseases.

    Science.gov (United States)

    Schwartz, Noah G; Rattner, Adi; Schwartz, Alan R; Mokhlesi, Babak; Gilman, Robert H; Bernabe-Ortiz, Antonio; Miranda, J Jaime; Checkley, William

    2015-09-01

    Sleep disordered breathing (SDB) is a highly prevalent condition in high-income countries, with major consequences for cardiopulmonary health, public safety, healthcare utilization, and mortality. However, its prevalence and effect in low- and middle-income countries are less well known. We sought to determine the prevalence, risk factors, and comorbidities of SDB symptoms in four resource-limited settings. Cross-sectional analysis of the CRONICAS Cohort, a population-based age- and sex-stratified sample. Four resource-limited settings in Peru varying in altitude, urbanization, and air pollution. There were 2,682 adults aged 35 to 92 y. Self-reported SDB symptoms (habitual snoring, observed apneas, Epworth Sleepiness Scale), sociodemographics, medical history, anthropometrics, spirometry, blood biomarkers were reported. We found a high prevalence of habitual snoring (30.2%, 95% confidence interval [CI] 28.5-32.0%), observed apneas (20.9%, 95% CI 19.4-22.5%) and excessive daytime sleepiness (18.6%, 95% CI 17.1-20.1%). SDB symptoms varied across sites; prevalence and adjusted odds for habitual snoring were greatest at sea level, whereas those for observed apneas were greatest at high altitude. In multivariable analysis, habitual snoring was associated with older age, male sex, body mass index (BMI), and higher socioeconomic status; observed apneas were associated with BMI; and excessive daytime sleepiness was associated with older age, female sex, and medium socioeconomic status. Adjusted odds of cardiovascular disease, depression, and hypertension and total chronic disease burden increased progressively with the number of SDB symptoms. A threefold increase in the odds of having an additional chronic comorbid disease (adjusted odds ratio 3.57, 95% CI 2.18-5.84) was observed in those with all three versus no SDB symptoms. Sleep disordered breathing symptoms were highly prevalent, varied widely across four resource-limited settings in Peru, and exhibited strong

  14. Mode of action based risk assessment of the botanical food-borne alkenylbenzene apiol from parsley using physiologically based kinetic (PBK) modelling and read-across from safrole.

    Science.gov (United States)

    Alajlouni, Abdalmajeed M; Al Malahmeh, Amer J; Kiwamoto, Reiko; Wesseling, Sebastiaan; Soffers, Ans E M F; Al-Subeihi, Ala A A; Vervoort, Jacques; Rietjens, Ivonne M C M

    2016-03-01

    The present study developed physiologically-based kinetic (PBK) models for the alkenylbenzene apiol in order to facilitate risk assessment based on read-across from the related alkenylbenzene safrole. Model predictions indicate that in rat liver the formation of the 1'-sulfoxy metabolite is about 3 times lower for apiol than for safrole. These data support that the lower confidence limit of the benchmark dose resulting in a 10% extra cancer incidence (BMDL10) that would be obtained in a rodent carcinogenicity study with apiol may be 3-fold higher for apiol than for safrole. These results enable a preliminary risk assessment for apiol, for which tumor data are not available, using a BMDL10 value of 3 times the BMDL10 for safrole. Based on an estimated BMDL10 for apiol of 5.7-15.3 mg/kg body wt per day and an estimated daily intake of 4 × 10(-5) mg/kg body wt per day, the margin of exposure (MOE) would amount to 140,000-385,000. This indicates a low priority for risk management. The present study shows how PBK modelling can contribute to the development of alternatives for animal testing, facilitating read-across from compounds for which in vivo toxicity studies on tumor formation are available to compounds for which these data are unavailable. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  15. Data base of accident and agricultural statistics for transportation risk assessment

    Energy Technology Data Exchange (ETDEWEB)

    Saricks, C.L.; Williams, R.G.; Hopf, M.R.

    1989-11-01

    A state-level data base of accident and agricultural statistics has been developed to support risk assessment for transportation of spent nuclear fuels and high-level radioactive wastes. This data base will enhance the modeling capabilities for more route-specific analyses of potential risks associated with transportation of these wastes to a disposal site. The data base and methodology used to develop state-specific accident and agricultural data bases are described, and summaries of accident and agricultural statistics are provided. 27 refs., 9 tabs.

  16. Data base of accident and agricultural statistics for transportation risk assessment

    International Nuclear Information System (INIS)

    Saricks, C.L.; Williams, R.G.; Hopf, M.R.

    1989-11-01

    A state-level data base of accident and agricultural statistics has been developed to support risk assessment for transportation of spent nuclear fuels and high-level radioactive wastes. This data base will enhance the modeling capabilities for more route-specific analyses of potential risks associated with transportation of these wastes to a disposal site. The data base and methodology used to develop state-specific accident and agricultural data bases are described, and summaries of accident and agricultural statistics are provided. 27 refs., 9 tabs

  17. Estimation of second primary cancers risk based on the treatment planning system

    International Nuclear Information System (INIS)

    Jin Chufeng; Sun Guangyao; Liu Hui; Zheng Huaqing; Cheng Mengyun; Li Gui; Wu Yican; FDS Team

    2011-01-01

    Estimates of second primary cancers risk after radiotherapy has become increasingly important for comparative treatment planning. A new method based on the treatment planning system to estimate the risk of second primary cancers was introduced in this paper. Using the Advanced/Accurate Radiotherapy Treatment System(ARTS), a treatment planning system developed by the FDS team,the risk of second primary cancer was estimated over two treatment plans for a patient with pancreatic cancer. Based on the second primary cancer risk, the two plans were compared. It was found that,kidney and gall-bladder had higher risk to develop second primary cancer. A better plan was chosen by the analysis of second primary cancer risk. The results showed that this risk estimation method we developed could be used to evaluate treatment plans. (authors)

  18. Evidence-based risk assessment and communication: a new global dengue-risk map for travellers and clinicians.

    Science.gov (United States)

    Jentes, Emily S; Lash, R Ryan; Johansson, Michael A; Sharp, Tyler M; Henry, Ronnie; Brady, Oliver J; Sotir, Mark J; Hay, Simon I; Margolis, Harold S; Brunette, Gary W

    2016-06-01

    International travel can expose travellers to pathogens not commonly found in their countries of residence, like dengue virus. Travellers and the clinicians who advise and treat them have unique needs for understanding the geographic extent of risk for dengue. Specifically, they should assess the need for prevention measures before travel and ensure appropriate treatment of illness post-travel. Previous dengue-risk maps published in the Centers for Disease Control and Prevention's Yellow Book lacked specificity, as there was a binary (risk, no risk) classification. We developed a process to compile evidence, evaluate it and apply more informative risk classifications. We collected more than 839 observations from official reports, ProMED reports and published scientific research for the period 2005-2014. We classified each location as frequent/continuous risk if there was evidence of more than 10 dengue cases in at least three of the previous 10 years. For locations that did not fit this criterion, we classified locations as sporadic/uncertain risk if the location had evidence of at least one locally acquired dengue case during the last 10 years. We used expert opinion in limited instances to augment available data in areas where data were sparse. Initial categorizations classified 134 areas as frequent/continuous and 140 areas as sporadic/uncertain. CDC subject matter experts reviewed all initial frequent/continuous and sporadic/uncertain categorizations and the previously uncategorized areas. From this review, most categorizations stayed the same; however, 11 categorizations changed from the initial determinations. These new risk classifications enable detailed consideration of dengue risk, with clearer meaning and a direct link to the evidence that supports the specific classification. Since many infectious diseases have dynamic risk, strong geographical heterogeneities and varying data quality and availability, using this approach for other diseases can

  19. Health risk assessment and the practice of industrial hygiene.

    Science.gov (United States)

    Paustenbach, D J

    1990-07-01

    It has been claimed that there may be as many as 2000 airborne chemicals to which persons could be exposed in the workplace and in the community. Of these, occupational exposure limits have been set for approximately 700 chemicals, and only about 30 chemicals have limits for the ambient air. It is likely that some type of health risk assessment methodology will be used to establish limits for the remainder. Although these methods have been used for over 10 yr to set environmental limits, each step of the process (hazard identification, dose-response assessment, exposure assessment, and risk characterization) contains a number of traps into which scientists and risk managers can fall. For example, regulatory approaches to the hazard identification step have allowed little discrimination between the various animal carcinogens, even though these chemicals can vary greatly in their potency and mechanisms of action. In general, epidemiology data have been given little weight compared to the results of rodent bioassays. The dose-response extrapolation process, as generally practiced, often does not present the range of equally plausible values. Procedures which acknowledge and quantitatively account for some or all of the different classes of chemical carcinogens have not been widely adopted. For example, physiologically based pharmacokinetic (PB-PK) and biologically based models need to become a part of future risk assessments. The exposure evaluation portion of risk assessments can now be significantly more valid because of better dispersion models, validated exposure parameters, and the use of computers to account for complex environmental factors. Using these procedures, industrial hygienists are now able to quantitatively estimate the risks caused not only by the inhalation of chemicals but also those caused by dermal contact and incidental ingestion. The appropriate use of risk assessment methods should allow scientists and risk managers to set scientifically valid

  20. Risk-based prioritization at Hanford Nuclear Site

    International Nuclear Information System (INIS)

    Hesser, W.A.; Mosely, M.T.

    1995-11-01

    This paper describes the method used to incorporate risk-based decision making into the Hanford resource allocation process. This method, the Revised Priority Planning Grid, is used as a tool to calculate benefits and benefit-to-cost ratios for comparison of environmental cleanup activities. The tool is based on Hanford Site objectives. Benefits are determined by estimating the impact on those objectives resulting from funding specific environmental management activities. Impacts are also a function of the weights associated with the objectives. These weights in the Revised Priority Planning Grid reflect US Development of Energy management values, which were obtained through a formal value-elicitation process. With modification to the objectives and weights, the Revised Priority Planning Grid could be used in different situations. By factoring in environmental, safety, and health risk and assigning higher scores to those activities that provide the most benefit, the Revised Priority Planning Grid is a reproducible, scientific way of scoring competing activities or interests