Ethics and fundamental principles of risk acceptance criteria

Ethics are concerned with distinguishing between what actions are “right” and “wrong” and what values are “good” and “bad”, etc. and there is a long academic tradition in discussing ethics and ethical theories. Risk acceptance criteria, on the other hand, distinguish between levels of risks that are acceptable and levels that are intolerable. In some sense, one may say that risk acceptance criteria distinguishes between “good” and “bad” systems and activities with regards to the risk they expose the society or elements of a society to and there is thus an obvious link between ethics and risk acceptance criteria or to risk management at large. However, there are few references in the literature that explores this link, and in this paper, the ethical foundation of fundamental principles of risk acceptance criteria will be elaborated upon.This paper considers some important principles for establishing risk acceptance criteria for safety critical systems and activities. The various principles and the philosophies behind them might at first sight seem contradictory and exclusive, but it is demonstrated how they may coexist in one and the same regulatory regime; They may complement each other in order to achieve the overall safety objectives of society. Then, some brief considerations of the ethical foundations for the principles will be given and some relevant examples of actual risk acceptance criteria will be given from the maritime industries. However, it is believed that the principles and discussions are of general interest and apply to all areas of technical risk and to safety regulations in a broader perspective.     

我国触电防护基础理论和观念存在问题剖析

触电形式、触电防护措施、供电系统的选择属于触电防护的基本问题.就触电形式而言,存在分类不完整、不同分类之间缺乏联系等问题,从触电相关导电体着手,提出了多层次系统化触电形式分类方法.就触电防护措施而言,就IEC最新标准由“平面式”分类转向“立体式”分类的深层意义进行了解读,并对“立体式”分类方法仍存在的问题进行了分析,提出了改进建议;指明我国翻译制定的等同标准未能充分体现IEC“立体式”分类方法的真正用意.就供电系统选择而言,“只能借用过流保护装置完成漏电保护”时代已经结束,建议我国从标准层面上放弃对TN供电系统的推荐,积极推广TT系统.     

Integration of accident scenario generation and multiobjective optimization for safety-cost decision making in chemical processes

Investment in Chemical Process Industries for improving their safety requires considering risk level, environmental effect, cost and many other aspects simultaneously. This paper focuses on a new systematic method of finding the most cost–risk–effective investment scenario set. The method uses the automatic accident scenario generation technique first to find a set of the most dangerous scenarios. Then it uses the multiobjective optimization method to decide the priority of the investment. These computations includes considering many constraints such as limited budget, environmental requirements and social demands. The Styrene Monomer plant case study proves the practical use of this integration method of accident scenario generation and multiobjective optimization.     

基于频繁模式树的一种关联规则挖掘算法及其在铁路隧道安全管理中的应用

关联规则的FP-growth算法是数据挖掘中性能较好的一种算法,笔者在分析该算法的基础上进行改造探讨,并提出了一种基于FP-tree的高性能关联规则挖掘算法FP-growthN,该新算法特别适合对那些数据量很大但数据项很稀疏的数据进行挖掘。将新算法用于挖掘铁路隧道各病害的关联中,通过对成都铁路局管辖的2005年的2787条隧道病害数据的343条重点隧道有效病害数据的关联分析,得出了各隧道病害之间隐藏着的关系。新法的提出及其应用结果对铁路部门制定检测标准和防治隧道病害有一定的指导作用。     

A new approach to estimate nuclide ratios from measurements with activities close to background

Measurements of low-level radioactivity often give results of the order of the detection limit. For many applications, interest is not only in estimating activity concentrations of a single radioactive isotope, but focuses on multi-isotope analyses, which often enable inference on the source of the activity detected (e.g. from activity ratios). Obviously, such conclusions become questionable if the measurement merely gives a detection limit for a specific isotope. This is particularly relevant if the presence of an isotope, which shows a low signal only (e.g. due to a short half-life or a small transition probability), is crucial for gaining the information of interest.     

Fuzzy adaptive management of social and ecological carrying capacities for protected areas

Commonly used methods of evaluating the degree of consistency of protected area ecosystems with social and ecological carrying capacities are likely to result in decision errors. This occurs because such methods do not account for imprecision and uncertainty in inferring the degree of ecosystem consistency from an observed ecosystem indicator. This paper proposes a fuzzy adaptive management approach to determine whether a protected area ecosystem is consistent with ecological and social carrying capacities and, if not, to identify management actions that are most likely to achieve consistency when there is uncertainty about the current degree of consistency and how alternative management actions are likely to influence that consistency. The proposed approach is illustrated using a hypothetical example that uses an ecosystem indicator that reflects combinations of different levels of user satisfaction and conservation of threatened and endangered species. Application of the proposed fuzzy adaptive management approach requires a protected area manager to: (1) identify alternative management actions for achieving ecosystem consistency with social and ecological carrying capacities in each of several management zones in a protected area; (2) randomly assign alternative management actions to management zones; (3) define fuzzy sets for the ecosystem indicator and degree of ecosystem consistency, and fuzzy relations between the ecosystem indicator and the degree of ecosystem consistency; (4) monitor the indicator in each management zone; (5) define fuzzy sets based on the observed indicator in each management zone; and (6) combine the fuzzy sets defined on the observed indicator and the fuzzy relations between the indicator and the degree of ecosystem consistency to reach conclusions about the most likely degree of consistency for alternative management actions in each management zone. The fuzzy adaptive management approach proposed here is advantageous when the benefits of avoiding the decision errors inherent with crisp and stochastic decision rules outweigh the added cost of implementing the approach.     

Revision of deposition and weathering parameters for the ingestion dose module (ECOSYS) of the ARGOS and RODOS decision support systems

The ECOSYS model is the ingestion dose model integrated in the ARGOS and RODOS decision support systems for nuclear emergency management. The parameters used in this model have however not been updated in recent years, where the level of knowledge on various environmental processes has increased considerably. A Nordic work group has carried out a series of evaluations of the general validity of current ECOSYS default parameters. This paper specifically discusses the parameter revisions required with respect to the modelling of deposition and natural weathering of contaminants on agricultural crops, to enable the trustworthy prognostic modelling that is essential to ensure justification and optimisation of countermeasure strategies. New modelling approaches are outlined, since it was found that current ECOSYS approaches for deposition and natural weathering could lead to large prognostic errors.     

Inexact multistage stochastic integer programming for water resources management under uncertainty

In this study, an inexact multistage stochastic integer programming (IMSIP) method is developed for water resources management under uncertainty. This method incorporates techniques of inexact optimization and multistage stochastic programming within an integer programming framework. It can deal with uncertainties expressed as both probabilities and discrete intervals, and reflect the dynamics in terms of decisions for water allocation through transactions at discrete points of a complete scenario set over a multistage context. Moreover, the IMSIP can facilitate analyses of the multiple policy scenarios that are associated with economic penalties when the promised targets are violated as well as the economies-of-scale in the costs for surplus water diversion. A case study is provided for demonstrating the applicability of the developed methodology. The results indicate that reasonable solutions have been generated for both binary and continuous variables. For all scenarios under consideration, corrective actions can be undertaken dynamically under various pre-regulated policies and can thus help minimize the penalties and costs. The IMSIP can help water resources managers to identify desired system designs against water shortage and for flood control with maximized economic benefit and minimized system-failure risk.     

An inexact two-stage mixed integer linear programming method for solid waste management in the City of Regina

In this study, an interval-parameter two-stage mixed integer linear programming (ITMILP) model is developed for supporting long-term planning of waste management activities in the City of Regina. In the ITMILP, both two-stage stochastic programming and interval linear programming are introduced into a general mixed integer linear programming framework. Uncertainties expressed as not only probability density functions but also discrete intervals can be reflected. The model can help tackle the dynamic, interactive and uncertain characteristics of the solid waste management system in the City, and can address issues concerning plans for cost-effective waste diversion and landfill prolongation. Three scenarios are considered based on different waste management policies. The results indicate that reasonable solutions have been generated. They are valuable for supporting the adjustment or justification of the existing waste flow allocation patterns, the long-term capacity planning of the City's waste management system, and the formulation of local policies and regulations regarding waste generation and management.     

The law and economics of reclamation bonds

It is becoming a standard practice for governments to require mining operations to post reclamation bonds. Yet, there have been few theoretical treatments examining the rationale for bonding mechanisms, and even fewer empirical treatments of the effectiveness of bonding. This paper addresses some of these holes in the literature. It begins by examining the rationale underlying reclamation bonds, and discusses the strengths and weaknesses of bonding as a tool for enforcing reclamation requirements. The role of bonding mechanisms is to help enforce standards, not necessarily yield efficient outcomes, and these mechanisms are best viewed as a complement to — not a substitute for — liability rules. The paper also examines the effectiveness of bonding by drawing on evidence from hardrock mining on public lands in the western United States.