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111.
In pest risk assessment it is frequently necessary to make management decisions regarding emerging threats under severe uncertainty. Although risk maps provide useful decision support for invasive alien species, they rarely address knowledge gaps associated with the underlying risk model or how they may change the risk estimates. Failure to recognize uncertainty leads to risk‐ignorant decisions and miscalculation of expected impacts as well as the costs required to minimize these impacts. Here we use the information gap concept to evaluate the robustness of risk maps to uncertainties in key assumptions about an invading organism. We generate risk maps with a spatial model of invasion that simulates potential entries of an invasive pest via international marine shipments, their spread through a landscape, and establishment on a susceptible host. In particular, we focus on the question of how much uncertainty in risk model assumptions can be tolerated before the risk map loses its value. We outline this approach with an example of a forest pest recently detected in North America, Sirex noctilio Fabricius. The results provide a spatial representation of the robustness of predictions of S. noctilio invasion risk to uncertainty and show major geographic hotspots where the consideration of uncertainty in model parameters may change management decisions about a new invasive pest. We then illustrate how the dependency between the extent of uncertainties and the degree of robustness of a risk map can be used to select a surveillance network design that is most robust to knowledge gaps about the pest. 相似文献
112.
湖北省高校大学生浮躁心理现状调查 总被引:1,自引:0,他引:1
通过文献资料和问卷调查以及数理统计法等研究方法,对湖北省普通高校大学生浮躁心理的现状及表现进行了调查,在此基础上分析其产生的原因,并探讨消除这种心态的方法和措施。 相似文献
113.
两点射线追踪是解决复杂地质结构下反射波射线正演的有效方法。在初至波层析射线追踪算法基础上,提出了一种两点射线追踪方法,利用层析网格对模型进行离散化,通过两阶段法射线追踪,分别对激发点和接收点按向前处理过程计算模型单元及节点的旅行时,两次时间相加作为最小旅行时,再在目的层界面邻域扫描最小旅行时子震源网格单元,用粒子群算法在该单元内扫描全局最小旅行时点,得到反射点位置与反射夹角,再利用向后处理过程运用旅行时线性插值算法,从反射点分别到激发点、接收点反向追踪射线路径,最后得到反射波两点射线路径。 相似文献
114.
Feyzan Erkip Guliz Mugan 《Innovation: The European Journal of Social Science Research》2010,23(3):181-198
Time-use surveys have been rich data sources in many countries for a long time. Turkey was among the countries that realized the potential of time-use surveys quite late and completed the first national survey in 2006. Despite its importance for a wide range of issues and applications, the first survey has flaws in design, which reduce its effectiveness and reliability. This is mostly due to disregarding cultural factors while tracking the methodology of European examples. This study aims to propose more appropriate methods of gathering time-use data in the Turkish context through a field survey in Ankara, the capital city. A mixed methodology that combines quantitative and qualitative methods effectively was applied and used to enrich data. The influence of space use was stressed and leisure activities were utilized to exemplify the use and benefits of mixed methods. 相似文献
115.
Abstract The 24-h dietary intake, nutritional status parameters and psychosomatic factors of two-shift, three-shift and day workers were compared. Estimations of the dietary intake (across a work cycle) were made by use of a nutrient database. No significant differences were found between the groups for a large number of nutritional variables: intake of energy; intake and percentage of energy from protein, fat, total carbohydrates and sucrose; intake of coffee; and intake and density of vitamins and minerals. Only minor differences were found between the groups with regard to the quantitative intake of alcohol and calcium, and with regard to the quality of the diet (percentage of energy from alcohol, density of calcium). The groups differed significantly with respect to attitude towards work hours (three-shift workers being most negative in their attitude) and sleep disturbances (shift workers being most negative). The three-shift workers were more evening-oriented and they had higher concentrations of glucose in their blood. It was concluded that work hours not related to nutritional intake—at least not when total amounts across time are considered. It was also concluded that work hours were not related to Body Mass Index or blood lipids: triglycerides, total cholesterol, LDL (low-density lipoprotein) cholesterol and HDL (high-density lipoprotein) cholesterol. 相似文献
116.
Mattias Bengtsson Tomas Berglund Maria Oskarson 《The British journal of sociology》2013,64(4):691-716
Studies of the relationship between class position and political outlooks still only have a limited understanding of the class‐related mechanisms that matter for ideological orientations. This article presents a comprehensive analysis of the mechanisms that link class position and left/right and authoritarian/libertarian orientations. Besides main factors such as income, career prospects, job security, education, class origin and class identification, the significance of work‐related factors such as work autonomy, working in a team, a physically demanding job and a mentally demanding job is studied. The findings are based on a survey specifically designed for this purpose and collected in Sweden in 2008/2009. A great deal of the association between class position and left/right orientations is explained by socio‐economic conditions; different classes sympathize with policies that will benefit them economically. Another important factor is class identification. Work‐related factors also have relevance, but the effect of class position on left/right orientations works mainly through the remuneration system. Class position is also related to authoritarian/libertarian orientations. However, this relationship is less explained by socio‐economic position per se, but is rather an effect of the educational system and its allocation of the workforce into different class positions. It also turns out that work‐related factors do not explain the class effects; however, a physically demanding job shows a unique effect. Overall, our findings suggest that besides factors such as class position, income, education and class identification, we need to consider work‐related aspects to derive a more complete understanding of the distribution of ideological orientations in Western societies. 相似文献
117.
马治国 《西安交通大学学报(社会科学版)》2011,31(2):61-66
在对国内首起收视率数据侵权案件分析的基础上,对此类特殊经营信息的认定与保护提出法律建议;认为商业秘密的本质是信息,包含技术信息与经营信息;相对而言,技术信息比较"硬",更容易被理解和保护,而经营信息比较"软",往往难以界定,保护起来也更加困难;针对于从事媒体的收视率调查公司而言,其提供的调查数据就是其主营业务的产品,以数据所包含的信息为媒体提供服务,获得相应的报酬;该信息是生产要素、主导产品和企业财产,同时也属于商业秘密,应当受到保护。 相似文献
118.
This article aims to contribute to the discussion about the ethics of research on children when studying sensitive issues such as violence. The empirical analysis is based on the accounts given by children (11 377) who completed a computer‐based questionnaire about their experiences of violence (‘The Finnish Child Victim Survey 2008’) and their reflections on the survey. We argue that experiences of violence should not be excluded from the research agenda on children due to ethical reasons, but that a more sophisticated practice should be developed instead to meet the needs and rights of children as informants. © 2010 The Author(s). Journal compilation 2010 National Children’s Bureau and Blackwell Publishing Limited. 相似文献
119.
卓俭华 《合肥工业大学学报(社会科学版)》2009,23(3):159-164
运用比较成熟的顾客满意度测评理论,以安徽省烟草商业企业为例,分析烟草公司面临的形势、经营状况、特别是其销售网络的现状,阐述了安徽烟草公司进行卷烟零售户满意度测评的意义,提出测评实施方法,测评卷烟零售户对烟草公司的满意程度,以了解零售户对烟草公司满意状况和存在的不满意方面。在此基础上,提出了改善这些不足的对策建议,期望以此提高卷烟零售户对烟草公司的满意程度。 相似文献
120.
20世纪90年代后期,中国的"三农"问题逐步突显出来,涉及"三农"问题的抽样调查也越来越多。然而,抽取样本依据的抽样框大多是基于普查和行政记录资料编制的单纯名录抽样框。单纯名录抽样框的使用存在很多弊端。拟从抽样框的建立与更新维护两个阶段进行分析,提出解决现有问题的具体思路。在抽样框的建立阶段,建立名录抽样框和区域抽样框相结合的双重简单抽样框,并在此简单抽样框的基础上添加特征群,构建适合不同调查类别的复杂抽样框;在抽样框的更新维护阶段,通过合理地制度安排,以普查数据为基础,以建设抽样框数据库为契机开展抽样框的更新维护工作,使建成的抽样框得到及时有效地更新维护。 相似文献