On the stability of the risk hull method for projection estimators

We consider in this paper the regularization by projection of a linear inverse problem Y=Af+εξ$Y=\mathit{Af}+\epsilon \xi$ where ξ$\xi$ denotes a Gaussian white noise, A   a compact operator and ε>0$\epsilon >0$ a noise level. Compared to the standard unbiased risk estimation (URE) method, the risk hull minimization (RHM) procedure presents a very interesting numerical behavior. However, the regularization in the singular value decomposition setting requires the knowledge of the eigenvalues of A$A$. Here, we deal with noisy eigenvalues: only observations on this sequence are available. We study the efficiency of the RHM method in this situation. More generally, we shed light on some properties usually related to the regularization with a noisy operator.     

后现代主义思潮与大学生价值观嬗变

进入新时期以来,在西方后现代主义思潮的浸染下,我国大学生的价值观发生了嬗变:由单一向多元转变、集体向个人位移、理想向世俗变动,甚至呈现出与我国社会主义核心价值观相背离的风险。后现代主义语境下的这一嬗变,因循于社会结构的变迁和大学生思维的非真实化变动,并深刻地受到大众传媒低俗化的影响。面对大学生价值观取向的变迁,引导大学生正确认识后现代主义思潮、强化大学生价值观再培育、发挥社会主义核心价值观的整合作用显得尤为重要。     

我国社会福利的发展取向:走进福利国家——基于风险社会理论的分析

风险社会理论是西方学者关于晚期现代性社会问题的一种思考。它虽然不能直接应用到我国语境中来,但能够促进我们对转型中的社会问题加以反思。从这个意义上,我国解决转型中的社会问题与社会风险的方略也与西方是不同的。当前中国正面临着多重社会风险,并且这些风险是不平等地分配的。要化解风险,需要我们建立制度化的社会福利制度,促进劳动力的去商品化、满足社会需要和维护社会公平。从长期来看,我们需要重返福利国家。     

Social perception of natural risks by local residents in developing countries—The example of the coastal area of Benin

Risk management and planning activities cannot be sustainably and efficiently implemented unless being based on a participative approach resulting from the problem consciousness and perception of the local inhabitants. This requires that the measures linked to problem perception and assessment by local stakeholders, above all by the population affected, are known. This investigation conducted in the flat Beninese coastal lagoon areas aims to assess the local inhabitants’ risk perception. The results are the following: (i) the stakeholders have group-specific ways of risk perception (according to ethnicity, social group, age); (ii) every risk management strategy should be based on the group-specific ways of risk perception and assessment; (iii) the acceptance of a given risk management strategy including interactive ways of participation can be advanced through education, dissemination of risk information as well as through communication between stakeholders.     

Communicating Contaminant Risks from Sport-Caught Fish: The Importance of Target Audience Assessment

A fish consumption health advisory has existed for New York Lake Ontario sport-caught fish since 1978. Our study objectives were to evaluate the effectiveness of the advisory for reaching potential target audiences and to identify appropriate advisory content, style, and dissemination methods using a risk communication planning model as an evaluation framework. We used a combination of mail surveys and personal interviews with three target audiences (opinion leaders among recreational anglers and charter boat operators, migrant farm workers, and low-income individuals) and two communicator groups (fishery experts and health care experts). The New York Lake Ontario advisory appeared to be successful in reaching and encouraging risk-mitigating fish consumption behavior in recreational angler opinion leaders and low-income individuals but not in migrant farm workers. The advisory may not be reaching two sensitive subpopulations, women of childbearing age and children. Communicators and target audiences differed in their assessments of important information to include in an advisory. The health advisory could be improved with additional information such as risk-reducing cooking and cleaning methods and by diversifying the dissemination methods to reach the variety of audiences who potentially consume Lake Ontario fish.     

Risk Homeostasis Theory and Traffic Accident Data

The risk homeostasis theory posits, in essence, that a control mechanism analogous to the thermal homeostatic system in warm-blooded animals tends to keep risk per unit time constant, and, as a consequence, the number of traffic accidents per unit time of driving also tends to remain constant, essentially independent of changes in the traffic safety system. It is the purpose of the present research to examine the validity of this claim using a wide variety of traffic accident data. All the data examined are found to be incompatible with the risk homeostasis theory. The only specific field accident data offered in the literature to support the risk homeostasis theory are found to, in fact, refute the theory. The accident data provide evidence that a rich variety of user responses occur. While it is possible for users to collectively respond in such a way that safety benefits are completely cancelled, such a response is not particularly common; it is certainly not universally occurring, as suggested by the risk homeostasis theory. It is concluded that the risk homeostasis theory should be rejected because there is no convincing evidence supporting it and much evidence refuting it.     

Final report of the Color Additive Scientific Review Panel

The Color Additives Scientific Review Panel considered whether there was information sufficient to perform a carcinogenic risk assessment on the colors D&C Red No. 19 (R-19), D&C Red No. 37 (R-37), D&C Orange No. 17 (O-17), D&C Red No. 9 (R-9), D&C Red No. 8 (R-8) and FD&C Red No. 3 (R-3) and to evaluate the assessments sent to FDA as part of the petitions for use of the colors for drug and external uses by the Cosmetic, Toiletry and Fragrance Association (CTFA). There is a lack of human data concerning the colors for making a human health assessment, so the assessments are based upon the extrapolation of animal data. The risk assessments are determined for exposure to single chemicals. Excluded from consideration are possible effects from exposure to multiple chemicals, such as co-carcinogenesis, promotion, synergism, antagonism, etc. In the light of recent efforts in establishing a consensus in risk assessment, the Panel has determined that the CTFA assessments for R-10, O-17, and R-9 are consistent with present acceptable usages, although it questions some of the assumptions used in the assessments. The Panel identified a number of general assumptions made, and discusses their validity, their impact on total uncertainty, and the potential options to address the gaps in understanding that necessitate the assumption. The Panel also derived revised risk estimates using more "reasonable" assumptions than "worst-case" situations, for 90th percentile and average exposure. For those assumptions that are easily quantifiable, the Panel's estimates are less than an order of magnitude lower than the CTFA risk estimates, indicating that the underestimates and overestimates of the CTFA risk estimates tend to balance each other. The impact of most of the assumptions is not quantifiable. The assessment for R-3 is complicated by the fact that there is no good skin penetrance study for this color. It was assumed that the penetrance is similar to that of another water-soluble xanthene color, R-19. It is expected that the absorption of the color is not likely to exceed that of the smaller molecule, R-19. Therefore, the risk estimates are similar to the CTFA estimates, but with different reasoning. The estimates for R-8 and R-37 are different from the others in that there is a lack of any exposure or toxicological information on these colors.(ABSTRACT TRUNCATED AT 400 WORDS)     

工程项目全过程风险管理模式探讨

本文在分析工程项目风险管理研究现状的基础上,从全过程管理角度,提出工程项目全过程风险管理模式:全过程风险管理机构的设置、全过程风险管理计划的制定、工程项目定义与决策阶段、设计与计划阶段、实施与控制阶段、竣工验收阶段四个阶段的风险管理。为项目业主和承包商更好的进行风险管理提供参考。     

集团公司战略风险管理的理论探讨

本文对集团公司战略管理过程中产生战略风险的机制从公司整体运行的角度进行研究,提出了公司战略风险管理的系统化理论模型,并从公司的环境、资源、能力和公司主题战略四个方面分析了战略风险产生的风险机理。并提出了环境和资源对公司战略主题目标的实现的影响及产生风险的机制。