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51.
Perception of Ecological Risk to Water Environments   总被引:12,自引:1,他引:12  
This paper examines lay and expert perceptions of the ecological risks associated with a range of human activities that could adversely affect water resource environments. It employs the psychometric paradigm pioneered in characterizing perceptions of human health risks, which involves surveys to obtain judgments from subjects about risk items in terms of several important characteristics of the risks. The paper builds on a previous study that introduced ecological risk perception. This second study employs a larger, more diverse sample, a more focused topic area, and comparisons between lay and expert judgments. The results confirm that a small set of underlying factors explain a great deal of variability in lay judgments about ecological risks. These have been termed Ecological Impact, Human Benefits, Controllability , and Knowledge. The results are useful in explaining subjects' judgments of the general riskiness of, and need for regulation of, various risk items. The results also indicate several differences and areas of agreement among the lay and expert samples that point to potential key issues in future ecological risk management efforts for water resources.  相似文献   
52.
On the basis of discussion and analysis during and following an ATSDR science panel on the bioavailability of mercury in soils, it is apparent that the default assumption of 100% relative bioavailability for mercury-contaminated soils is excessively conservative. However, current knowledge does not allow the development of default assumptions or guidelines for determining relative bioavailability of mercury in soils. Until such default assumptions or guidelines can be developed, site-specific assays of bioavailability, preferably using either animal bioassays or validated in vitro techniques, may provide the best approach for estimating soil-mercury bioavailability.  相似文献   
53.
TOT项目融资中国有资产转让定价的博弈分析   总被引:1,自引:0,他引:1  
本文以TOT项目融资方式为对象,运用博弈的方法,从合理分配国有资产经营期内增值收入的角度出发,得出这样的结论,在国有资产转让过程中,政府与私营资本之间的谈判是一系列复杂的博弈过程,在博弈中政府的最优行为是对国有资产转让进行招标,同时给予某一招标企业一定的中标优先权,这样政府能够较现行的国有资产转让方式获得更多的收益.  相似文献   
54.
核电站组织风险已经成为核电站安全运行重要的影响因素,在概率安全评价中考虑组织风险因素是核电安全研究的重要课题。文章在建立组织风险因素与PSA之间转换的概念框架的基础上,对组织风险因素进行分类。分类后的组织风险因素受人员行为形成因子的影响,其影响在人因可靠性分析中进行分析。计算和评估这些人员行为形成因子对于事故后操纵员的影响可以计算组织因素对核电站安全的影响。  相似文献   
55.
Melamine contamination of food has become a major food safety issue because of incidents of infant disease caused by exposure to this chemical. This study was aimed at establishing a safety limit in Taiwan for the degree of melamine migration from food containers. Health risk assessment was performed for three exposure groups (preschool children, individuals who dine out, and elderly residents of nursing homes). Selected values of tolerable daily intake (TDI) for melamine were used to calculate the reference migration concentration limit (RMCL) or reference specific migration limit (RSML) for melamine food containers. The only existing values of these limits for international standards today are 1.2 mg/L (0.2 mg/dm2) in China and 30 mg/L (5 mg/dm2) in the European Union. The factors used in the calculations included the specific surface area of food containers, daily food consumption rate, body weight, TDI, and the percentile of the population protected at a given migration concentration limit (MCL). The results indicate that children are indeed at higher risk of melamine exposure at toxic levels than are other groups and that the 95th percentile of MCL (specific surface area = 5) for children aged 1–6 years should be the RMCL (0.07 mg/dm2) for protecting the sensitive and general population.  相似文献   
56.
The evaluation of hazards from complex, large scale, technologically advanced systems often requires the construction of computer implemented mathematical models. These models are used to evaluate the safety of the systems and to evaluate the consequences of modifications to the systems. These evaluations, however, are normally surrounded by significant uncertainties related to the uncertainty inherent in natural phenomena such as the weather and those related to uncertainties in the parameters and models used in the evaluation.

Another use of these models is to evaluate strategies for improving information used in the modeling process itself. While sensitivity analysis is useful in defining variables in the model that are important, uncertainty analysis provides a tool for assessing the importance of uncertainty about these variables. A third complementary technique, is decision analysis. It provides a methodology for explicitly evaluating and ranking potential improvements to the model. Its use in the development of information gathering strategies for a nuclear waste repository are discussed in this paper.  相似文献   
57.
In risk assessment, the moment‐independent sensitivity analysis (SA) technique for reducing the model uncertainty has attracted a great deal of attention from analysts and practitioners. It aims at measuring the relative importance of an individual input, or a set of inputs, in determining the uncertainty of model output by looking at the entire distribution range of model output. In this article, along the lines of Plischke et al., we point out that the original moment‐independent SA index (also called delta index) can also be interpreted as the dependence measure between model output and input variables, and introduce another moment‐independent SA index (called extended delta index) based on copula. Then, nonparametric methods for estimating the delta and extended delta indices are proposed. Both methods need only a set of samples to compute all the indices; thus, they conquer the problem of the “curse of dimensionality.” At last, an analytical test example, a risk assessment model, and the levelE model are employed for comparing the delta and the extended delta indices and testing the two calculation methods. Results show that the delta and the extended delta indices produce the same importance ranking in these three test examples. It is also shown that these two proposed calculation methods dramatically reduce the computational burden.  相似文献   
58.
煤矿瓦斯爆炸事故单危险源风险度量模型研究   总被引:1,自引:0,他引:1  
本文研究了煤矿瓦斯爆炸事故危险源的分类,把危险源划分为人的不安全行为、机器设备不安全状态、环境不安全特征和管理缺陷四大类,并根据煤矿现场调查各类危险源的数据以及相应数学方法的特点,提出煤矿瓦斯爆炸事故人、机器设备(物)、环境、管理四类危险源的风险度量方法,在此基础上构建四类危险源的风险度量模型。研究表明,危险源的风险度量模型由风险发生的可能性、危险源重要度以及事故导致的损失构成;危险源风险发生的可能性,在具体应用中可以采用各类危险源的不可靠度、故障率等来衡量;危险源在事故中的重要度可以通过分析事故故障树种要素结构重要性获取。根据风险评价的结果,可以对危险源进行分级排序,从而为煤矿事故单危险源的控制提供依据。  相似文献   
59.
The three classic pillars of risk analysis are risk assessment (how big is the risk and how sure can we be?), risk management (what shall we do about it?), and risk communication (what shall we say about it, to whom, when, and how?). We propose two complements as important parts of these three bases: risk attribution (who or what addressable conditions actually caused an accident or loss?) and learning from experience about risk reduction (what works, and how well?). Failures in complex systems usually evoke blame, often with insufficient attention to root causes of failure, including some aspects of the situation, design decisions, or social norms and culture. Focusing on blame, however, can inhibit effective learning, instead eliciting excuses to deflect attention and perceived culpability. Productive understanding of what went wrong, and how to do better, thus requires moving past recrimination and excuses. This article identifies common blame‐shifting “lame excuses” for poor risk management. These generally contribute little to effective improvements and may leave real risks and preventable causes unaddressed. We propose principles from risk and decision sciences and organizational design to improve results. These start with organizational leadership. More specifically, they include: deliberate testing and learning—especially from near‐misses and accident precursors; careful causal analysis of accidents; risk quantification; candid expression of uncertainties about costs and benefits of risk‐reduction options; optimization of tradeoffs between gathering additional information and immediate action; promotion of safety culture; and mindful allocation of people, responsibilities, and resources to reduce risks. We propose that these principles provide sound foundations for improving successful risk management.  相似文献   
60.
Building a law-based government is a central element of the comprehensive framework for promoting the rule of law in China, while using evaluation to catalyze growth is in line with the incentive principle of management studies. Since China started to implement reform and opening up over thirty years ago, rule of law development and organizational evaluation have gone through several stages, each with different characteristics. Efforts to build a law-based government have met with success, but what the country now has is essentially still goal-oriented assessment. At present, this suffers from the lack of a clear goal orientation or definition of functions, an imperfect technical system and unsound motivation mechanisms, not to mention the practical problems of each government department going its own way, duplicating evaluations or being left rudderless. Drawing on a combination of value rationality and instrumental rationality and using government performance evaluation to promote the building of a law-based government not only conforms to the spirit of the rule of law and value rationality in government performance, but also strengthens the role of evaluation as an instrument for organizational management. Therefore, we need to create new evaluation theories, expand public participation, introducing diversified evaluating entities, improve technical systems, strengthen institutional buildup, and foster a performance-based culture. In addition, replacing goal-oriented assessment with performance evaluation will help the emergence of a new discipline—the performance evaluation of rule of law government, thus promoting multidisciplinary efforts to integrate and create new public administration theories in China.  相似文献   
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