Application Of Risk Evaluation Research Articles

A New Divergence Based on the Belief Bhattacharyya Coefficient with an Application in Risk Evaluation of Aircraft Turbine Rotor Blades

Belief divergence is a significant measure to quantify the discrepancy between evidence, which is beneficial for conflict information management in Dempster–Shafer evidence theory. In this article, three new concepts are given, namely, the belief Bhattacharyya coefficient, adjustment function, and enhancement factor. And based on them, a novel enhanced belief divergence, called EBD, is proposed, which can assess the correlation of subsets and fully reflect the uncertainty of multielement sets. The important properties of the EBD have been studied. In particular, a new EBD-based multisource information fusion method is designed to handle evidence conflict, where the weight of evidence is decided by the EBD between evidence and the information volume of each evidence. Compared with other methods, the proposed method in the applications of target recognition and iris classification can produce more rational and telling outcomes when dealing with conflict information. Finally, an application in risk priority evaluation of the failure modes of rotor blades of an aircraft turbine is provided to validate that the proposed method has the extensive applicability.

Data quality evaluation criteria for systematic review of epidemiology studies under the Toxic Substances Control Act (TSCA): refinement through practical application in risk evaluation

BACKGROUND AND AIM: The 2016 Frank R. Lautenberg Chemical Safety for the 21st Century Act and the 2017 Procedures for Chemical Risk Evaluation under the Amended Toxic Substances Control Act (TSCA) require the U.S. Environmental Protection Agency (EPA) to conduct risk evaluations using the best available science and weight of the scientific evidence. Therefore, EPA has developed systematic review methods including data quality evaluation criteria to evaluate scientific studies in specific disciplines including epidemiology. EPA has aimed to refine these criteria for practical application in risk evaluation of high-priority chemicals under TSCA. METHODS: EPA considered the pros and cons of multiple existing systematic review frameworks and guidance documents and drew upon these methodologies to develop data quality evaluation domains, metrics, and criteria for the systematic review of epidemiology studies under TSCA. EPA refined these domains, metrics, and criteria through practical application to add specificity to increase consistency among evaluators and to harmonize with the evaluation of animal toxicology studies under TSCA. RESULTS: EPA adopted aspects of methods including the National Toxicology Program (NTP) Office of Health Assessment and Translation (OHAT) and EPA’s Integrated Risk Information System (IRIS) methods, but also aimed to be consistent with other disciplines and to address TSCA scientific standards. CONCLUSIONS: EPA has further refined data quality evaluation criteria for systematic review of epidemiology studies under TSCA in response to comments from peer reviewers, the public, the National Academies, and the TSCA Science Advisory Committee on Chemicals (SACC). Systematic review of epidemiology studies is a critical component of protecting human health under TSCA. DISCLAIMER: The views expressed in this presentation are solely those of the authors and do not represent the policies of EPA. Mention of trade names or commercial products should not be interpreted as an endorsement by EPA. KEY WORDS: Systematic Review, Data Quality Evaluation

Time‐periodic model of wind speed and its application in risk evaluation of wind‐power‐integrated power systems

Risk evaluation of wind-power-integrated power systems requires a distinctive wind speed modelling technique. Existing techniques of mid- and long-term risk assessment mainly focus on annual wind speed pattern rather than its monthly and daily patterns, which cannot reflect the time-varying characteristics of power system risk. This article proposes a time-periodic model of wind speed which incorporates two parts. The first part is the monthly wind speed patterns which can be represented as time-periodic functions, while the other one is the fluctuation in daily wind speeds that can be denoted as a random variable following a certain probability distribution. With this model, a risk evaluation procedure for wind-power-integrated power system is developed. Collected wind speed data from four representative sites in China are used to verify the proposed model. The application of the proposed wind model and risk assessment method is tested by calculating annual and monthly risk indices of a modified IEEE-RTS79 system. Results can provide references for power system planning, mid- and long-term dispatching, and monthly generation scheduling.

Probabilistic dual hesitant fuzzy set and its application in risk evaluation

The concurrence of randomness and imprecision widely exists in real-world problems. To describe the aleatory and epistemic uncertainty in a single framework and take more information into account, in this paper, we propose the concept of probabilistic dual hesitant fuzzy set (PDHFS) and define the basic operation laws of PDHFSs. For the purpose of applications, we also develop the basic aggregation operator for PDHFSs and give the general procedures for information fusion. Next, we propose a visualization method based on the entropy of PDHFSs so as to analyze the aggregated information and improve the final evaluation results. The proposed method is then applied to the risk evaluations. A case study of the Arctic geopolitical risk evaluation is presented to illustrate the validity and effectiveness. Finally, we discuss the advantages and the limitations of the PDHFS in detail.

Generalized Discrete Fuzzy Number and Application in Risk Evaluation

In this paper, the definition of generalized discrete fuzzy numbers is introduced, and a representation theorem of such fuzzy numbers is obtained. Based on the representation theorem, it is shown that the usual addition and multiplication which are defined by Zadeh’s extension principle do not preserve the closeness of the operation, and a new addition operation and a new multiplication operation are defined, which not only preserve the closeness of the operation, but also are easy to calculate. Then some weak orders on the generalized discrete fuzzy number space are defined, and their properties are investigated. At last, a practical example is given to show the application of the algorithmic version to rank uncertain or imprecise discrete quantity.

Landing Risk Assessment of Carrier-Based Aircraft Based on Fuzzy Multi-Attribute Group Decision Making

In allusion to the special characteristic of longitudinal loop risk assessment in landing process of carrier-based aircraft, this paper extends the concept of decision-maker, and proposes a method of fuzzy multi-attribute decision making with normal fuzzy linguistic variables as decision-making information. Based on the establishment of carrier-based aircraft landing model, the expressions of risk evaluation indicators are ensured, and the relative attribute weight is calculated by the simulation of the safe flight area in landing process. The application of risk assessment is implemented by analogy between standard points and decision-maker. The analysis of numerical examples shows that the method is practical and the application in risk evaluation is reasonable. Multipoint decision information is complete and decision results accord with distributions of touchdown points. Comprehensive evaluation of flight safety with different pilots can be realized.

The Improved Fuzzy Analytic Hierarchy Process and Its Application in Risk Evaluation of Wind Power Project Investment

The Improved Fuzzy Analytic Hierarchy Process and Its Application in Risk Evaluation of Wind Power Project Investment

Application of risk evaluation in chemical industry occupational hazards evaluation

危险性评价和管理理论始于1983年,由美国国家研究委员会(NRC)首先提出,并将其划分为危害识别(Hazard identification)、剂量-反应评价(Dose response assessment)、暴露评价(Exposure assessment)和危险度描述(Risk characterization)4个阶段[1].自此,围绕危险性评价与管理的4个阶段对环境污染物致机体危害的危险性评价技术和方法得到了广泛应用[2-3].危险度评价与管理模式是由多步骤组成的,关于识别、分析和评价职业危害,确定危险度水平和管理危险度的一个系统的关联过程。

Relevance of Animal Studies in Regulatory Toxicology: Current Approaches and Future Opportunities

With rapidly increasing knowledge of toxicological processes, the scientific value and relevance of toxicity studies for risk assessment must be re-evaluated. In this paper, it is proposed that the rigid risk evaluation currently required should be replaced by a more flexible, case-by-case approach, in order to increase the relevance of each animal test conducted. The development of new types of toxicity studies and their application in risk evaluation are also described.

Gauss-Markov Load Model for Application in Risk Evaluation and Production Simulation

Gauss-Markov Load Model for Application in Risk Evaluation and Production Simulation

A Gauss-Markov load model for application in risk evaluation and production simulation

Load uncertainty contributes to system operational risk; thus the study of system operating reserve or unit commitment risk requires a load model that includes the uncertainty in load as well as the variation with time. The authors propose a Gauss-Markov load model. This random process model includes both the time variation and the uncertainty in load. This load model is used to predict, conditional on what is known at a previous hour, the mean and the variance of the system hourly load. This mean and variance are required for a system operating reserve study and a broad spectrum of production simulations. The proposed load model is described, the model is justified, and the model is illustrated via an example. >