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721.
环境空间决策支持集成系统的设计原理与应用   总被引:3,自引:0,他引:3       下载免费PDF全文
空间决策支持系统(SDSS)是地理信息系统(GIS)和决策支持系统(DSS)的有机结合.笔者在已有研究成果基础上,以厦门市环境管理空间决策支持集成系统(XME-SDSS)为例,介绍了空间信息集成系统的设计原理和实现方法,包括数据分析模型、系统的数据流、数据库结构以及系统的集成方式.   相似文献   
722.
Abstract: The most comprehensive data on many species come from scientific collections. Thus, we developed a method of population viability analysis (PVA) in which this type of occurrence data can be used. In contrast to classical PVA, our approach accounts for the inherent observation error in occurrence data and allows the estimation of the population parameters needed for viability analysis. We tested the sensitivity of the approach to spatial resolution of the data, length of the time series, sampling effort, and detection probability with simulated data and conducted PVAs for common, rare, and threatened species. We compared the results of these PVAs with results of standard method PVAs in which observation error is ignored. Our method provided realistic estimates of population growth terms and quasi‐extinction risk in cases in which the standard method without observation error could not. For low values of any of the sampling variables we tested, precision decreased, and in some cases biased estimates resulted. The results of our PVAs with the example species were consistent with information in the literature on these species. Our approach may facilitate PVA for a wide range of species of conservation concern for which demographic data are lacking but occurrence data are readily available.  相似文献   
723.
城市化与环境污染:中国省际面板数据的实证研究   总被引:2,自引:0,他引:2  
对环境库兹涅茨曲线(EKC)假说进行了扩展,选取1998~2005年中国30个省(市、自治区)的面板数据,构建了6类环境污染指标同城市化水平及控制变量间的计量模型,并运用Eviews软件进行了实证检验。研究结果表明:4类污染物同城市化水平之间存在倒U形曲线关系,另外2类污染物同城市化水平之间存在正U形曲线关系,目前中国大体上已经进入U形曲线的右半段,但由于地区发展差距的存在,各地进入曲线右半段的时间不同;控制变量的加入不仅改变了转折点出现的时间,而且改变了某些污染指标同城市化水平之间的U形曲线关系;贸易开放并不一定造成环境的恶化,“污染天堂”假说在中国不成立;产业结构变动是造成环境污染的重要因素;技术进步引致的单位GDP能耗下降能减轻环境污染压力;快速的经济增长将导致更加严重的环境污染。  相似文献   
724.
The 26 December 2004 tsunamis around the Indian Ocean exposed the vulnerability of many coastal communities, including those serving tourists. To draw conclusions regarding disaster risk reduction for tourism in coastal areas, this study surveyed international tourists who survived the tsunami regarding their perceptions and experiences of the disaster. Semi-structured interviews were completed between January and June 2005 of 55 primary interviewees who were international tourists in locations affected by the tsunami. The qualitative data from the interviews yielded commonalities across four main themes with relevance to disaster risk reduction: information and awareness, warning systems, personal preparation, and livelihoods. Three areas are suggested as topics to highlight for further investigation: the connections between sustainable tourism and disaster vulnerability, the role of tourists in disasters, and disaster risk reduction education.  相似文献   
725.
ITS数据质量控制技术及应用研究   总被引:8,自引:1,他引:7  
通过总结智能交通系统 (ITS)数据质量控制中所涉及的数据属性 ,提出了ITS数据质量控制算法 :根据阈值理论和交通流理论 ,针对错误数据、丢失数据和不精确数据设计相应的判别规则 ,利用数值计算方法对其进行修正 ,并提出了针对数据中的不规则时间点的修正算法。在对北京市和美国圣安东尼奥市的两组不同时间序列的ITS数据进行实践应用后 ,比较质量控制前后的数据特征 ,证明所提出的算法能够有效地解决数据质量问题 ,提高数据的精确度。最后 ,对国内外ITS数据进行质量控制后的结论和经验作了总结。  相似文献   
726.
In this paper, we construct a model in which the impact of pollution on health is exerted through both direct and indirect channels. The indirect channel is captured by a production function in which the principal health-improving factor, income growth, can be realized only in the cost of pollution increase. This model is then tested by the aggregated chronicle disease data in over 78 Chinese counties. Our results show, after attaining the threshold of 8 μ g/m^2, continuous increase in industrial SO2 emission density will lead the ratio of population suffering chronicle diseases, among which respiratory diseases occupy a significant proportion, to rise. However, owing to technological progress in pollution control activities, the needed SO2 emission to produce one unit of GDP diminishes with time. Therefore, the negative effect from pollution augmentation on public health seems to be recompensed more and more by the positive effect of economic growth.  相似文献   
727.
This paper analyzes the impacts of urbanization and unemployment rate on China’s divorce rate with the panel data of 31 Chinese provinces from 2000 to 2011. The study manifests as follows. First, the significant influence of urbanization cannot be observed on the rising breakdown since the latter is not the inevitable result of the former. In the second place, unemployment rate has a significant negative influence on divorce rate, namely, with the former increasing, the latter will decrease, which echoes the perspective of divorce cost. And finally, this paper also finds positive effects of per capita fixed investment, old-age dependency rate, average household size, the proportion of floating population and population density, and negative correlation of average education attainment on divorce rate.  相似文献   
728.
Abstract

In this paper, we construct a model in which the impact of pollution on health is exerted through both direct and indirect channels. The indirect channel is captured by a production function in which the principal health-improving factor, income growth, can be realized only in the cost of pollution increase. This model is then tested by the aggregated chronicle disease data in over 78 Chinese counties. Our results show, after attaining the threshold of 8 μg/m2, continuous increase in industrial SO2 emission density will lead the ratio of population suffering chronicle diseases, among which respiratory diseases occupy a significant proportion, to rise. However, owing to technological progress in pollution control activities, the needed SO2 emission to produce one unit of GDP diminishes with time. Therefore, the negative effect from pollution augmentation on public health seems to be recompensed more and more by the positive effect of economic growth.  相似文献   
729.
The analysis of traffic safety data archives has improved markedly with the development of procedures that are heavily dependent upon computers. Three such procedures are described here. The first procedure involves using computers to assist in the identification and correction of invalid data. The second procedure makes greater computational demands, and involves using computerized algorithms to fill in the “gaps” that typically occur in archival data when information regarding key variables is not available. The third and most computer-intensive procedure involves using data mining techniques to search archives for interesting and important relationships between variables. These procedures are illustrated using examples from data archives that describe the characteristics of traffic accidents in the USA and Australia.  相似文献   
730.
Data on traffic injury cases that includes both the crash circumstances and the health outcome is a key tool for creating appropriate motor-vehicle injury prevention policies. The aim of this study was to explore the feasibility of the probabilistic linkage of police and emergency department data relating to motor-vehicle injury cases in Barcelona. A probabilistic linkage process was performed using local police reports (n = l2,481) and hospital emergency department data (n = 16,733) for all traffic injury cases that occurred in 1997. In almost two out of every three matched pairs for the injured person, at least five of the seven variables coincided, and in 7.3% of the cases all variables coincided. This work has allowed the empirical development of combined methods for the linkage of police and healthcare sources of information at the local level, which are the preliminary steps towards the construction of a data base that would include full information on the circumstances and the consequences of motor-vehicle crashes.  相似文献   
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