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排序方式: 共有1328条查询结果,搜索用时 234 毫秒
1.
Modelling daily multivariate pollutant data at multiple sites   总被引:7,自引:1,他引:6  
Summary. This paper considers the spatiotemporal modelling of four pollutants measured daily at eight monitoring sites in London over a 4-year period. Such multiple-pollutant data sets measured over time at multiple sites within a region of interest are typical. Here, the modelling was carried out to provide the exposure for a study investigating the health effects of air pollution. Alternative objectives include the design problem of the positioning of a new monitoring site, or for regulatory purposes to determine whether environmental standards are being met. In general, analyses are hampered by missing data due, for example, to a particular pollutant not being measured at a site, a monitor being inactive by design (e.g. a 6-day monitoring schedule) or because of an unreliable or faulty monitor. Data of this type are modelled here within a dynamic linear modelling framework, in which the dependences across time, space and pollutants are exploited. Throughout the approach is Bayesian, with implementation via Markov chain Monte Carlo sampling.  相似文献   
2.
Low dose risk estimation via simultaneous statistical inferences   总被引:2,自引:0,他引:2  
Summary.  The paper develops and studies simultaneous confidence bounds that are useful for making low dose inferences in quantitative risk analysis. Application is intended for risk assessment studies where human, animal or ecological data are used to set safe low dose levels of a toxic agent, but where study information is limited to high dose levels of the agent. Methods are derived for estimating simultaneous, one-sided, upper confidence limits on risk for end points measured on a continuous scale. From the simultaneous confidence bounds, lower confidence limits on the dose that is associated with a particular risk (often referred to as a bench-mark dose ) are calculated. An important feature of the simultaneous construction is that any inferences that are based on inverting the simultaneous confidence bounds apply automatically to inverse bounds on the bench-mark dose.  相似文献   
3.
Summary.  Official employment-related performance indicators in UK higher education are based on the population of students responding to the 'First destination supplement' (FDS). This generates potentially biased performance indicators as this population of students is not necessarily representative of the full population of leavers from each institution. University leavers who do not obtain qualifications and those who do not respond to the FDS are not included within the official analysis. We compare an employment-related performance indicator based on those students who responded to the FDS with alternative approaches which address the potential non-random nature of this subgroup of university leavers.  相似文献   
4.
基于层次分析法的职务绩效定量分析   总被引:1,自引:0,他引:1  
针对企业绩效评价中存在的问题,引用管理决策的层次分析法,从系统论的角度,对企业职务绩效指标进行整体分析和比较,更为科学地确定了绩效体系中各指标的权重。  相似文献   
5.
The development of a Municipal Information System, or currently better known as a local spatial data infrastructure, is considered complex due to the required inter-institutional relationships. In many developing countries Geographical Information Systems (GISs) are introduced but the benefits are modest as no changes take place in technical and organisational structure of organisations. Digital databases and computer-aided design (CAD) maps are mushrooming in great variety within different private and public institutions, municipal organisations and even within single departments and with structures similar to the paper period and thus operating on a stand-alone basis.Many national mapping agencies are not able to provide large-scale digital urban base maps, while the absence or low quality of cadastres makes those basic core data sets unavailable or inaccessible. The result is that duplication and incompatible data are frequently observed and also donor-driven stand-alone projects have a limited impact through the lack of institutional embedding and are not able to mature from the project to the institutional level. However, a positive sign is that there is an increasing awareness among data producers and consumers that investments in the development of digital data sets should be combined to reduce costs and increase benefits from especially GIS, and information and communication technology (ICT) in general.Within Trujillo a long-term vision was developed to make full use of ICT and GIS to modernise all operations of the Municipality to increase the efficiency and effectiveness of its tasks. However, large investments are not feasible due to the very limited municipal budgets. To guarantee the support of the municipal council, short-term results are required. This paper describes three ‘products’ as part of the vision to develop through a step-by-step approach a local spatial data infrastructure for Trujillo.The three, rather different, products are:
1. fiscal cadastre, to increase municipal revenues through property taxation;
2. an ‘environmental atlas’ based on a compatible spatial and attribute data sets from a variety of organisations; and
3. a municipal website with interactive GIS and meta data information.
The paper concludes with some comments on the institutional and political requirements for the successful development of a local spatial data infrastructure and stresses that such an infrastructure is not a product but an incremental development process that will progress only in case such a process is simple, cost effective, user-friendly, and flexible with clear products.Political interest and institutional stability and genuine interest for inter-institutional cooperation will add much to the success of this process.  相似文献   
6.
生态道德教育是一个普遍性的社会伦理问题。生态危机的特征 ,生物共同体的联系以及我国生态环境的现状 ,都客观地要求我们必须注重人与自然界的和谐发展 ,加强全民性的生态道德教育。  相似文献   
7.
在我国,环境审计对于国家审计、内部审计和民间审计来说都是一个新内容。作为环境管理系统的重要组成部分,环境审计具有重大的意义。因此,建立健全环境审计制度,采取切实可行的措施,是环境管理和环境审计的重要任务。  相似文献   
8.
本文论述了中外艺术的多元分类法,对其进行科学、系统地对照比较,并结合中外艺术发展的现状和艺术教育的实际情况提出自己的见解,即艺术四大门类分类法是当今较为科学、较易接受、较能应用的艺术分类法.并在四大门类划分的基础上,对各门类中的艺术科目进行了重新整合和构建.  相似文献   
9.
企业作为环境污染的主要肇事者, 理应承担起治理环境污染的责任, 由此就会产生相应的环境支出和环境收益, 并因而影响企业的财务状况和经营成果。将环境活动纳入企业会计核算体系, 反映企业对自然资源的消耗和对环境的污染及其治理情况, 披露环境会计信息, 成为传统会计面临的新课题, 本文主要对环境会计信息披露的内容和方式进行探讨  相似文献   
10.
不同添加剂预混料对哺乳仔猪生产性能的影响   总被引:4,自引:0,他引:4  
以窝为单位将 70窝哺乳仔猪随机分为 7组 ,设 1个对照组 (试验I组 ) ,6个试验组。试验组分别添加 2 0 0mg/kg派富 (含芽胞杆菌等复合微生态制剂 ) (Ⅱ )、1%的甲酸吡啶铬 2 0 0mg/kg(Ⅲ )、2 0mg/kg泰乐菌素 (Ⅳ )、1%中药免疫增强剂 (黄芪、远智等复合中草药 ) (Ⅴ )、1%的益康XP(酵母培养物 ) (Ⅵ )以及 2 0mg/kg的硝呋烯宗 (Ⅶ )。经过 15d的试验 ,其结果表明 :试验组较对照组提高日增重 11.37% - 34.12 % ,其中Ⅴ、Ⅵ组达到显著水平 (p <0 .0 5 ) ;提高采食量 1.5 9% - 12 .30 % ;降低饲料增重比 8.4 % - 2 0 .2 0 % ;降低仔猪腹泻频次 10 .34- 31.0 3%。经无菌粪样检验 ,试验各组大肠杆菌、沙门氏菌、葡萄球菌数均低于对照组 ,差异不显著 (p >0 .0 5 ) ;而乳酸杆菌、双岐杆菌均高于对照组 ,差异不显著 (p >0 .0 5 )。经部分血液指标分析 ,试验各组的血液各项理化指标均在正常范围内 ,且各组间差异不显著 (p >0 .0 5 )。  相似文献   
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