Narrow Results

The software for a failure diagnosis system can be represented in terms of production rules; the condition part represents a system failure condition and the conclusion part corresponds to a cause of the system failure or an appropriate protective action to be taken. This paper proposes a safety assessment model of the software to evaluate its contribution to the risk caused by the entire failure diagnosis system. The proposed risk criterion considers not only the reliability of hardware components of the failure diagnosis system, but also the reliability characteristics of the system to be monitored. Conventional verification and validation methods of rule-based systems assume that the software reliability can be achieved by maintaining the consistent relation between condition parts and conclusion parts. However, the risk criterion derived in this paper shows that the software for a failure diagnosis system cannot be optimized without considering these environmental factors.

At present, the shortage of water resources has severely restricted the sustainable development of economy in China, and water saving management contract (WSMC) is an important measure to effectively alleviate the problem of water shortage. However, the complexity of WSMC projects makes it difficult for water saving service enterprises to distinguish the risk of different projects. Therefore, based on combination weighting method, this paper tries to establish a risk evaluation method for WSMC projects. First, the risk evaluation index system of WSMC is constructed via the hierarchical holographic modeling method. Second, to evaluate the risk of different projects, a score function is defined to reflect the statistical dispersion of the comprehensive risk of each project, and then a multiple objective optimization problem is constructed. Third, after solving this optimization problem, a comprehensive risk score function is defined, and then a combination weighting method for the risk evaluation of WSMC project, which effectively incorporate expert knowledge and historical data, is established combing with the analytic hierarchy process and anti-entropy method. Finally, numerical examples are given to verify the feasibility of the proposed method. The proposed method not only enriches the research on the risk evaluation method of WSMC projects, but also provides reference for the project selection of water saving service enterprises.

As a result of the disaster of nuclear power plant caused by the 2011 off the pacific coast of Tohoku Earthquake, establishment of a method to estimate the influence of slopes on the seismic safety of nuclear facilities has become necessary. The creation of such a method can yield important information regarding potential risk as well as risk management regarding seismic safety. The existing guidelines used to evaluate landslide risk provide guidance for landslide zoning as well as how landslide risk can be reduced and avoided. According to these guidelines, either people or houses are typically used as targets of risk evaluation. Particularly, for a specific slope, it is necessary to evaluate the damage of the potentially affected structures quantitatively and systematically. Therefore, the definition and basic assessment procedure of three limit states (stability limit, reachable limit and damage limit) are herein described. Furthermore, an evaluation case for a slope model describes the influence of slope collapse due to an earthquake. In this case, the fragility curves, as well as the occurrence probability for each limit state are described and an evaluation example is provided. Regarding new ideas and methods to evaluate the conditional reachable probability and the conditional damage probability as well as a method to evaluate the total probability of all three limit states are proposed. From the results obtained in our example case, it is found that systematical assessment of the risk information of facilities damaged due to slope collapse is useful, and is made possible via numerical analysis.

Metro security check risk evaluation plays an important role in identifying security check risks. The differential security check mode can improve passenger passage efficiency and metro service quality. In this paper, a multi-level comprehensive evaluation index system of differential security checks at stations is constructed, and the combination assignment method is selected as the method of determining index weights. Furthermore, a risk evaluation model of differential security checks in the metro based on the extension theory is established. The case study shows that the selected station of the Nanjing metro is in a relatively safe state.

The risk analysis of key nodes is the foundation and important link to ensure the safety of the sea lanes. To analyze the risk and provide a basis for safety management, this paper proposes a risk assessment model based on a multi-state fuzzy Bayesian network. Firstly, a fault tree model is built for risk events, revealing the causal relationships between the risk events and the influential factors. Secondly, the multiple fault state of nodes is described by fuzzy numbers. The multi-state fuzzy conditional probability table is applied to describe the uncertain logical relationship between nodes. An expert investigation method based on a confidence index is proposed to establish a multi-state, conditional probability interval table that describes the logical relationship between variables. Finally, the model parameters are determined by obtaining the exact values of the conditional probability interval table using the α-weighted valuation method for defuzzification. The risk probability distribution based on prior knowledge and known evidence is calculated. The key risk factors are then identified. Taking the risk analysis for key nodes of sea lanes as an example, the application results demonstrated the feasibility and efficiency of the proposed method.

Due to the rapid development of the internet, there has been increased attention from researchers regarding the electronic commerce (e-commerce) risk and security issues. This paper utilizes the analytic hierarchy process combined with the fuzzy comprehensive evaluation method to analyze and evaluate e-commerce risk because it provides more reasonable and scientific findings than the traditional hierarchical analysis method to evaluate the e-commerce risk of enterprise M. Firstly, this paper establishes the risk evaluation index system of e-commerce. Secondly, the analytic hierarchy process and fuzzy comprehensive evaluation method was used to determine the weight of each security risk index and risk factors of fuzzy membership. Lastly, the safety risk assessment results were calculated and discussed. The results obtained demonstrated that enterprise M’s e-commerce system contains several weak links and thus further analysis for influence factors of e-commerce security risk should be conducted.