我国老年人应用互联网的态度与相关行为决策的调查——以信息查询与电邮收发为例

分别以家庭和公共场所为背景,对老年人应用互联网的状况进行调查,分析老年人应用互联网的态度、互联网在其相关决策中的作用及其长期积累的经验对决策的影响。从已有策略、人与人的合作、信息域的界定3方面得出老年人应用互联网的态度与相关决策的评价结果,分析我国老年人应用互联网的特征和障碍。     

Examining Risk in Mineral Exploration

Successful mineral exploration strategy requires identification of some of the risk sources and considering them in the decision-making process so that controllable risk can be reduced. Risk is defined as chance of failure or loss. Exploration is an economic activity involving risk and uncertainty, so risk also must be defined in an economic context. Risk reduction can be addressed in three fundamental ways: (1) increasing the number of examinations; (2) increasing success probabilities; and (3) changing success probabilities per test by learning. These provide the framework for examining exploration risk. First, the number of prospects examined is increased, such as by joint venturing, thereby reducing chance of gambler's ruin. Second, success probability is increased by exploring for deposit types more likely to be economic, such as those with a high proportion of world-class deposits. For example, in looking for 100+ ton (>3 million oz) Au deposits, porphyry Cu-Au, or epithermal quartz alunite Au types require examining fewer deposits than Comstock epithermal vein and most other deposit types. For porphyry copper exploration, a strong positive relationship between area of sulfide minerals and deposits' contained Cu can be used to reduce exploration risk by only examining large sulfide systems. In some situations, success probabilities can be increased by examining certain geologic environments. Only 8% of kuroko massive sulfide deposits are world class, but success chances can be increased to about 15% by looking in settings containing sediments and rhyolitic rocks. It is possible to reduce risk of loss during mining by sequentially developing and expanding a mine—thus reducing capital exposed at early stages and reducing present value of risked capital. Because this strategy is easier to apply in some deposit types than in others, the strategy can affect deposit types sought. Third, risk is reduced by using prior information and by changing the independence of trials assumption, that is, by learning. Bayes' formula is used to change the probability of existence of the deposit sought on the basis of successive exploration stages. Perhaps the most important way to reduce exploration risk is to employ personnel with the appropriate experience and yet who are learning.     

基于3DCM的中尺度地面风场的空间分析研究

为提升城市环境的生态自净能力,采用基于3DCM的中尺度综合方法建立了城市地面风场的空间分析及预测模型,并对典型区域进行了实证分析,发现中尺度地面风场可采用风道网络参数进行有效模拟和量化。     

煤层气项目经济评价辅助决策系统设计及应用

用VisualC 6．0建立了煤层气项目经济评价辅助决策系统，整个系统的设计遵循“针对性、实用性、科学性、易操作性和通用性”的原则。本系统具有产能预测、综合评价、不确定性分析及计算机自动绘图等功能，并以实例验证了该系统是实用、有效的。     

企业迁移研究进展

企业迁移研究对区域经济统筹发展、区域政策的制定具有重要的指导意义．本研究通过梳理国内外相关文献,从企业迁移的类型、三大基础理论学派的对比和国内外在实证研究的研究内容和方法上的差异等3个方面对企业迁移研究进行了较为系统的回顾与总结,并提出未来研究的展望,指出企业迁移的内部因素、企业迁移与区域经济发展的关系、企业迁移的绩效研究等应成为未来研究的重点领域．     

基于多目标决策与层次分析法的最佳路径模型

在最佳路径选择问题中,如何综合考虑多种因素的综合影响以及确定各因素的影响大小是一个关键性问题。通过建立最佳路径的道路层次模型,给出多目标决策模型和因素评分模型,并用层次分析法确定各影响因素权值的方法建立了基于多影响因素与综合评判的最佳路径模型。同时,在Dijkstra最短路径算法的基础上,应用文章所提模型方法实现了在多...     

From agriculture to nature – a study of drivers of land use change in a peri-urban landscape

In this article, we investigate drivers behind land use changes in a peri-urban landscape. The research focuses on the motives and factors behind landowners’ decision-making in relation to land use changes, with the objective of improving our knowledge of the dynamics of land use change processes on farmland. An actor-centred conceptual framework is developed on the basis of the concept of lenses of decision-making. Data on farm and farmer characteristics were collected through a survey conducted in Roskilde Municipality, Denmark, a peri-urban landscape with a high level of landscape dynamics. A logistic regression analysis was used to analyse the relationship between nine purposively selected farm and farmer characteristics and the landscape activities of 93 landowners in the municipality. The results indicate that small farms, farms without livestock and landowners with a basic level of education are less likely to engage in landscape activities. A cluster analysis was used to analyse patterns of motives associated with land use changes. The results correspond with the intrinsic interests and family considerations suggested in the lenses of the decision-making framework, and in addition shows that the desire to improve the qualities of the property was the dominant motive.     

Earthquake disaster risk index for Canadian cities using Bayesian belief networks

Devastation observed from global earthquakes highlights the need for a decision-making tool to aid in prioritisation and resource allocation for seismic risk management. In this paper, a seismic risk index assessment tool is developed using Bayesian belief network (BBN) that considers geological, engineering, economic, social, political and cultural factors. Previously proposed hierarchical structure is modified and modelled using a BBN. The subjective probabilities of the BBN are derived using expert knowledge. Furthermore, to illustrate versatility of the proposed model, a case study is undertaken for 11 Canadian cities.     

基于多目标决策模型的封育工程绩效研究——以旱泉沟流域为例

以旱泉沟流域封山育林育草调查研究为基础,通过农户调查、专项统计监测、野外试验研究等手段,在专家咨询、统计分析的基础上,运用多目标决策评价模型建立封育工程生态恢复综合效果评价指标体系,系统全面地分析了封育工程生态恢复的效果,以期为西部地区小流域综合治理和退化生态系统恢复提供理论依据。研究结果表明,旱泉沟流域封育工程的生态恢复效果显著,年经济价值为5.217×10⁶元,其中生态系统稳定性和土壤保持能力恢复较好,综合效果评分为77.70,达到良好水平。     

城市防灾公园规划建设的综合决策分析

针对当前防灾公园规划实践的不足,该文集成GIS空间分析技术和多目标决策模型,从适宜性评价、服务域分析、避难网络构建方面探讨城市防灾公园规划建设的综合决策方法体系,同时选择上海市黄浦区开展实证研究,旨在为我国城市防灾公园规划建设提供系统的决策思路和技术方法.