Spill accident modeling: a critical survey of the event-decision network in the context of IMO's formal safety assessment

In this paper, we present the relationship between an oil spill-assessing approach, namely the event-decision network (EDN) and the formal safety assessment (FSA) of the International Maritime Organization (IMO). We focus on various points at which the Network incorporates basic features of the FSA in order to formulate a state-of-the-art, original strategic tool. In keeping with a safety-friendly effort, we developed the EDN, which implements a scenario-driven, generic tree framework. Moreover, the IMO, under the umbrella of decision-making, has introduced FSA, which is a systematic methodology for enhanced maritime safety by using risk and cost/benefit criteria. It is of interest to describe the introduced spill-scenario analysis/simulation and to pinpoint its interconnections with the aforementioned official instrument. Among other things, the goal of such a task is the enhancement of marine safety and the subsequent protection of seas from oil spills.     

Risk-based rules for crane safety systems

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.     

A historical overview of probabilistic risk assessment development and its use in the nuclear power industry: a tribute to the late Professor Norman Carl Rasmussen

This paper reviews the historical development of the probabilistic risk assessment (PRA) methods and applications in the nuclear industry. A review of nuclear safety and regulatory developments in the early days of nuclear power in the United States has been presented. It is argued that due to technical difficulties for measuring and characterizing uncertainties and concerns over legal challenges, safety design and regulation of nuclear power plants has primarily relied upon conservative safety assessment methods derived based on a set of design and safety principles. Further, it is noted that the conservatism adopted in safety and design assessments has allowed the use of deterministic performance assessment methods. This approach worked successfully in the early years of nuclear power epoch as the reactor design proved to be safe enough. However, it has been observed that as the conservative approach to design and safety criteria proved arbitrary, and yielded inconsistencies in the degree to which different safety measures in nuclear power plants protect safety and public heath, the urge for a more consistent assessment of safety became apparent in the late 1960s. In the early 1970s, as a result of public and political pressures, then the US Atomic Energy Commission initiated a new look at the safety of the nuclear power plants through a comprehensive study called ‘Reactor Safety Study’ (WASH-1400, or ‘Rasmussen Study’—after its charismatic study leader Professor Norman Rasmussen of MIT) to demonstrate safety of the nuclear power plants. Completed in October 1975, this landmark study introduced a novel probabilistic, systematic and holistic approach to the assessment of safety, which ultimately resulted in a sweeping paradigm shift in safety design and regulation of nuclear power in the United States in the turn of the Century. Technical issues of historic significance and concerns raised by the subsequent reviews of the Rasmussen Study have been discussed. Effect of major events and developments such as the Three Mile Island accident and the Nuclear Regulatory Commission and the Nuclear Industry sponsored studies on the tools, techniques and applications of the PRA that culminated in the present day risk-informed initiatives has been discussed.     

A fuzzy-logic-based approach to qualitative safety modelling for marine systems

Safety assessment based on conventional tools (e.g. probability risk assessment (PRA)) may not be well suited for dealing with systems having a high level of uncertainty, particularly in the feasibility and concept design stages of a maritime or offshore system. By contrast, a safety model using fuzzy logic approach employing fuzzy IF–THEN rules can model the qualitative aspects of human knowledge and reasoning processes without employing precise quantitative analyses. A fuzzy-logic-based approach may be more appropriately used to carry out risk analysis in the initial design stages. This provides a tool for working directly with the linguistic terms commonly used in carrying out safety assessment. This research focuses on the development and representation of linguistic variables to model risk levels subjectively. These variables are then quantified using fuzzy sets. In this paper, the development of a safety model using fuzzy logic approach for modelling various design variables for maritime and offshore safety based decision making in the concept design stage is presented. An example is used to illustrate the proposed approach.     

Use of risk assessment in the nuclear industry with specific reference to the Australian situation

The use of risk assessment in the nuclear industry began in the 1970s as a complementary approach to the deterministic methods used to assess the safety of nuclear facilities. As experience with the theory and application of probabilistic methods has grown, so too has its application. In the last decade, the use of probabilistic safety assessment has become commonplace for all phases of the life of a plant, including siting, design, construction, operation and decommissioning. In the particular case of operation of plant, the use of a ‘living’ safety case or probabilistic safety assessment, building upon operational experience, is becoming more widespread, both as an operational tool and as a basis for communication with the regulator. In the case of deciding upon a site for a proposed reactor, use is also being made of probabilistic methods in defining the effect of design parameters. Going hand in hand with this increased use of risk based methods has been the development of assessment criteria against which to judge the results being obtained from the risk analyses. This paper reviews the use of risk assessment in the light of the need for acceptability criteria and shows how these tools are applied in the Australian nuclear industry, with specific reference to the probabilistic safety assessment (PSA) performed of HIFAR.     

危险品运输选线的定量风险评价模型

定量化风险评价是危险品道路运输选线的重要决策依据,但在如何定量其风险方面往往存在分歧。系统地总结了常见的危险品运输定 量风险评价模型,将其划分为传统风险评价模型及其特例、感知风险模型、条件风险模型、侧重后果的避灾风险模型以及改进后的传统风险模 型5类,分析了风险评价模型的性质和原则,对将来的研究发展提出了建议 。     

A perceptual computing–based method to prioritize intervention actions in the probabilistic risk assessment techniques

Probabilistic risk assessment techniques as the systematic tools have been widely used on the different type of industrial sectors to reduce the estimated risk to an acceptable level. The fact is to design inherently safety; hazards have to be eliminated and reduced in risk as much as possible with the consideration of several interventions. In this regard, multicriteria decision making (MCDM) science is commonly integrated with the probabilistic risk assessment techniques to improve the safety performance of a system. Thus, it has been widely used to assist decision makers in controlling the identified process hazards in a different type of engineering applications. However, by increasing the complexity of industrial sectors as well as human being judgments, typical MCDM methods cannot highly guarantee their output results. According to this point, proposing MCDM methods based on mathematical programming have been interested in scholars due to high reliability and feasibility of the results. In this paper, we extended integration of MULTIMOORA approach with the Choquet integral under subjectivity circumstances to prioritize corrective actions in a typical probabilistic risk assessment technique. To illustrate the efficiency and feasibility of the proposed method, it has been applied in a real case study.     

Ship collision risk assessment for the Singapore Strait

The Singapore Strait is considered as the bottleneck and chokepoint of the shipping routes connecting the Indian and the Pacific Ocean. Therefore, the ship collision risk assessment is of significant importance for ships passing through the narrow, shallow, and busy waterway. In this paper, three ship collision risk indices are initially proposed to quantitatively assess the ship collision risks in the Strait: index of speed dispersion, degree of acceleration and deceleration, and number of fuzzy ship domain overlaps. These three risk indices for the Singapore Strait are estimated by using the real-time ship locations and sailing speeds provide by Lloyd's MIU automatic identification system (AIS). Based on estimation of these three risk indices, it can be concluded that Legs 4W, 5W, 11E, and 12E are the most risky legs in the Strait. Therefore, the ship collision risk reduction solutions should be prioritized being implemented in these four legs. This study also finds that around 25% of the vessels sail with a speed in excess of the speed limit, which results in higher potentials of ship collision. Analysis indicates that the safety level would be significantly improved if all the vessels follow the passage guidelines.     

Risk-based asset management in heat recovery steam generators

Abstract

A risk based inspection and asset management process has been implemented on a number of HRSGs for a client in Australasia. This process has been undertaken in a phased approach consisting of: data gathering on site, detailed risk assessment of all critical items of static plant, risk calculation and implementation of a risk based inspection plan based upon the results of the prior aspects of the assessment. The project has been streamlined through the use of dedicated risk based asset management software, RMS, developed specifically for the tasks described.

Following the programme of work major inspections have been undertaken, the results of which have been uploaded to the program to allow a subsequent detailed review of the new plant profile and hence risk reduction. This not only allows a clear report on progress to senior management, but ensures that the process is continually maintained and future maintenance is most efficiently deployed to ensure optimum plant efficiency. Furthermore the rigorous nature of the process and the traceability which it enforces is being used to apply for extension of mandatory inspection of pressure vessels, where appropriate, allowing longer run times for the plant such that major shutdowns can be aligned with the requirements of the gas turbine overhauls.     

水下隧道盾构法施工安全风险评估探讨

随着地铁、公路等交通隧道的不断发展,隧道往往穿越江河湖泊等水体,大直径泥水平衡盾构广泛应用于水下隧道施工。大直径盾构施工风险高、控制难度大,加上水下施工不确定因素多,风险因素具有不断动态变化的特点,使得施工过程中存在较大的风险。风险评估越来越多的应用于水下隧道施工安全管理中。文章介绍了大直径泥水盾构的几个特点,并对这几个特点引起风险增大的机理进行了分析,针对风险评估常用的几中方法中存在的不足,提出了一种改进的指数法,给出了该方法的评估流程及基本计算模型,并将该方法初步应用于某水下隧道施工风险评估。该方法能够适应风险因素的变化,并且不拘泥于真实概率,通过进一步的细化和完善,能够更好地适用于水下隧道施工安全风险评估。     

MSEs Credit Risk Assessment Model Based on Federated Learning and Feature Selection

Federated learning has been used extensively in business innovation scenarios in various industries. This research adopts the federated learning approach for the first time to address the issue of bank-enterprise information asymmetry in the credit assessment scenario. First, this research designs a credit risk assessment model based on federated learning and feature selection for micro and small enterprises (MSEs) using multi-dimensional enterprise data and multi-perspective enterprise information. The proposed model includes four main processes: namely encrypted entity alignment, hybrid feature selection, secure multi-party computation, and global model updating. Secondly, a two-step feature selection algorithm based on wrapper and filter is designed to construct the optimal feature set in multi-source heterogeneous data, which can provide excellent accuracy and interpretability. In addition, a local update screening strategy is proposed to select trustworthy model parameters for aggregation each time to ensure the quality of the global model. The results of the study show that the model error rate is reduced by 6.22% and the recall rate is improved by 11.03% compared to the algorithms commonly used in credit risk research, significantly improving the ability to identify defaulters. Finally, the business operations of commercial banks are used to confirm the potential of the proposed model for real-world implementation.     

基于Camshift的多特征自适应融合船舶跟踪算法

基于航道内船舶监控图像序列的多目标跟踪技术是开展船撞主动预警,提升桥区船舶通航安全的前提.基于颜色直方图的Camshift跟踪算法在复杂气象条件下无法得到准确的跟踪结果,本文提出了一种多特征自适应融合的多目标跟踪算法.该算法的目标模型由颜色、形状及纹理多特征自适应融合实现,增加了描述目标模型的可靠性和鲁棒性;在跟踪目标...     

SCAP: a new methodology for safety management based on feedback from credible accident-probabilistic fault tree analysis system

As it is conventionally done, strategies for incorporating accident--prevention measures in any hazardous chemical process industry are developed on the basis of input from risk assessment. However, the two steps-- risk assessment and hazard reduction (or safety) measures--are not linked interactively in the existing methodologies. This prevents a quantitative assessment of the impacts of safety measures on risk control.We have made an attempt to develop a methodology in which risk assessment steps are interactively linked with implementation of safety measures. The resultant system tells us the extent of reduction of risk by each successive safety measure. It also tells based on sophisticated maximum credible accident analysis (MCAA) and probabilistic fault tree analysis (PFTA) whether a given unit can ever be made 'safe'. The application of the methodology has been illustrated with a case study.     

冰区航行船舶冰阻力及六自由度运动响应的离散元分析EI北大核心CSCD

冰阻力是冰区船舶航行过程中的重要影响因素,对船舶航行性能及航行安全带来严峻挑战。该文采用扩展多面体离散元方法建立冰船动力作用过程的三维离散元方法,基于船舶推进功率与推进力间近似关系,将螺旋桨推力、冰载荷、舵力及水动力等载荷分开考虑,开展恒功率破冰船六自由度非线性操纵直航冰阻力及运动响应计算。为验证该离散元方法的可靠性,对比了碎冰区DUBROVIN及平整冰区LINDQVIST冰阻力公式计算结果。基于船舶在不同主机推进功率及复杂冰况下的直航冰阻力计算结果,展开对船舶破冰航速的影响因素分析。在此基础上,给出了船舶垂荡、横摇、纵摇等冰区船舶运动响应模拟结果和极地船舶运动响应预报结果,最后对碎冰及平整冰区船舶冰阻力及运动响应展开了对比分析。该方法可有效计算船舶冰阻力,其模拟结果可为冰区船舶运动响应及航行安全预警提供重要参考。     

An Analytical Model to Measure the Effectiveness of Safety Management Systems: Global Safety Improve Risk Assessment (G-SIRA) Method

The ever-increasing complexity of production systems, together with the need to obtain efficient processes with limited costs, has led companies to develop custom tools for process control and management. Even for risk assessment, the traditional models often are overcome by methods that are best suited to specific needs. In this context, the aim of this paper was to propose a new model, which we call the global safety improve risk assessment (G-SIRA). This model can classify risks and identify corrective actions that allow the best risk reduction at the lowest cost. The proposed model, which is based on improvements to previous research, uses the analytic hierarchy process approach to develop a valid and simple tool for risk management. The G-SIRA method has been tested in a real-world application, i.e., it was applied to all of the processes of a textile company, and the results were compared with those obtained from the classical approach failure mode, effects, and criticality analysis. The comparison clearly showed the effectiveness of the proposed model.     

基于IPSO-BP的船舶航迹预测研究

目的 面对复杂的海上交通及密集的物流交通流,及时有效地对船舶航迹进行跟踪预测显得尤为重要,针对传统船舶航迹预测方法精确度低且效率低下的问题,提出一种改进方法。方法 在船舶自动识别系统（AutomaticIdentificationSystem,AIS）数据的基础上,建立改进粒子群算法（IPSO）与BP神经网络相结合的船舶轨迹预测模型,利用船舶历史航行轨迹数据,实现对未来船舶运动的预测。选取宁波舟山港的船舶历史轨迹数据进行实验,并将IPSO-BP模型的实验结果与其他模型进行比较。结果 不同模型航迹预测对比结果表明,IPSO-BP模型的性能较好,其预测精度较高,适用于船舶轨迹预测。结论 使用IPSO-BP模型能够更加精准地预测船舶航迹,在船舶危险预警、船舶异常监测等方面具有重要的指导作用。     

特征相似的舰船噪声模型可信性分析

舰船噪声建模是研究水声信号处理和声纳系统的关键技术。从舰船噪声的时频域特性出发建立适应性广的舰船目标噪声模型,提出基于特征相似的模型可信性评估方法,并对舰船噪声模型进行可信性分析。     

Current practices for risk zoning around nuclear power plants in comparison to other industry sectors

This paper analyses the background and current status of the information basis leading to the definition of risk and emergency zones around nuclear power plants (NPPs) in different countries in Europe and beyond. Although dependable plant-specific probabilistic safety assessment (PSA) of level 2 and/or level 3 could in principle provide sufficiently detailed input to define the geographical dimension of a NPP's risk and emergency zones, the analysis of the status in some European and other countries shows that other, "deterministic" approaches using a reference accident are actually used in practice. Regarding use of level 2 PSA for emergency planning, the approach so far has been to use the level 2 PSA information retrospectively to provide the justification for the choice of reference accident(s) used to define the emergency plans and emergency planning zones (EPZs). There are significant differences in the EPZs that are defined in different countries, ranging from a few up to 80km. There is a striking contrast in the extent of using probabilistic information to define emergency zones between the nuclear and other high risk industry sectors, such as the chemical process industry, and the reasons for these differences are not entirely clear, since the risk of chemical industry is similar as that of the nuclear sector. The differences seem to be more related to risk perception than to the actual risk potential. Therefore, there is a strong need to be able to communicate risk information to the Public both before and following an accident. In addition, there is a need to educate the Public so that they can understand risk information in a comparative sense. Finally, based on the consensus discussions at a recent JRC/OECD International Seminar on Risk and Emergency Zoning around NPPs, a set of recommendations is given in the areas of: -a more comprehensive use of the available risk information for risk zoning purposes, -risk communication; -comparative (energy) risk assessment.     

Hazard-Based Design of the Bow-Tie Method to Prevent and Mitigate Mine Accidents

The mining trade involves many complicated and interrelated variables—its complex environment, abundant machinery and a plethora of other contributors to accidents. In both developed and developing countries, mining accidents have caused many casualties. However, a universal risk assessment method for mining accidents is has not yet been implemented. Among risk assessment methods, the bow-tie has been used in different industry processes and systems and has proven effective. In this paper, the bow-tie model is utilized to investigate the relationship among mining accident risks, safety measures and possible consequences. The paper illustrates the hazards of mining accidents using US mine accident data. It also shows how the consequences of mine accidents are summarized by laws and regulations of different countries. This paper also introduces a series safety measures from Chinese safety standards and how the safety measures prevent and mitigate risks. At the end of the paper, a case of mine water inrush is applied using the bow-tie approach. The results show that the method is effective for analyzing mine safety.     

高通量筛查和安全评估结合评价乳制品包装安全风险

目的 以乳制品包装为研究对象,建立一套科学评价食品接触材料安全风险的方法,全面评价食品接触材料在接触食品过程中带来的食品安全风险。方法 采用非靶向高通量筛查检测技术全面筛查食品模拟物中的重金属和有机物,根据权威数据库和物质毒理学资料进行危害评估,参考欧盟和美国膳食暴露量计算方法进行暴露评估,结合评估结果计算风险系数,最终表征食品接触材料的安全风险。结果 抽取了市面上的塑料、金属、涂料及复合包装等不同材质的乳制品包装进行检测,检出铜、铬、锰和锡等元素,以及有意添加物（如单体、溶剂、抗氧剂、光引发剂、爽滑剂、增塑剂等）、非有意添加物质（如抗氧剂降解产物、寡聚物等）。采用暴露评估和危害评估方法分别表征检出物的膳食暴露和健康指导值,安全风险评估风险系数分布在0.007%～9.4%之间,安全风险较低。结论 建立的食品接触材料安全评价方法是一种有效评价食品接触材料安全风险的方法,该方法具有一定的通用性,企业、行业和政府部门等可用于识别食品接触材料的安全风险,为减少和排除安全风险提供科学依据。