矿产资源开发整合绩效评价指标体系与评价方法研究

实行矿产资源开发整合是实现矿产资源合理开发利用的有效途径。在矿产资源开发整合评价指标选取原则下,建立了包括开采秩序、安全开采、资源利用效率、环境治理和社会效益等5大类指标构成的矿产资源开发整合绩效评价指标体系,提出运用模糊综合评价模型对矿产资源开发整合的绩效进行评价的方法,并对矿产资源开发整合绩效评价中应注意的一些问题进行了剖析。     

Puncture resistance of polyester (PET) and polypropylene (PP) needle-punched nonwoven geotextiles

It is common practice to use needle-punched nonwoven geotextiles as puncture protection for geomembranes against sharp objects like gravel or stones in either the soil above or the underlying soil/rock below. There are several design and experimental methods available for geotextile selection in this regard. None, however, directly address the type of resin or fiber from which the geotextile is made. This paper does exactly that insofar as a direct comparison of similar mass per unit area polyester (PET) versus polypropylene (PP) geotextiles are concerned. Furthermore, two types of PP geotextiles are evaluated; one made from continuous filaments and the other from staple fibers. Three different size and shaped puncture probes are used in the testing program. All three are ASTM Standards, i.e., D4833, D5495 and D6241.The test results clearly indicate that geotextiles made from PP fibers outperform those made from PET fibers at all masses evaluated. Clearly, the present trend of using PP resin for heavy nonwoven protection geotextiles seems justified on the basis of these test results. In addition, the continuous filament PP and staple fiber PP geotextiles performed equivalently over all mass ranges for the three different types of puncture tests.     

SBS改性沥青针入度指数影响因素探析

针入度指数是评价沥青感温性能的指标,SBS改性沥青的生产原料、加工工艺条件对针入度指数的影响有较大差别,其中改性剂、基质沥青和增容剂对针入度指数的影响较大,因此研究不同因素对SBS改性沥青针入度指数的影响,可为SBS改性沥青感温性能的改善提供一定的参考。     

IP环境下时钟同步网模型和指标的探讨

探讨和分析了时钟同步网指标和移动基站指标,结合本地网时间指标的分析,尝试给出了IP环境下同步网模型和指标分配。讨论的重点是时钟同步网,并在一定程度上论述了时间同步网。     

基于MPLS VPN的流量统计技术

MPLS VPN技术是未来构建VPN的发展方向,越来越受到客户和运营商的青睐.传统的基于IP的流量统计无法满足当前网络发展的需要,因此对MPLS VPN网络的流量进行分析,能够很好地规划网络并指导网络的设计,具有非常重要的意义.     

基于ELECTREⅠ法的装备修理过程质量评价研究

将修理过程拆分为4个主要修理工序,构建影响修理过程质量的评价指标体系.以我军4家同级别修理工厂的装备修理过程为例,运用ELECTREⅠ理论,建立装备修理过程质量的综合评价模型.通过提出净优势度的概念,很好地解决了ELECTRE Ⅰ理论评价结果不完全排序的问题,也进一步验证了评价模型的科学性和实用性.     

供应商评价系统的设计与实现

设计开发了基于改进模糊层次分析法的供应商综合评价管理系统,给出了供应商综合评价管理系统的系统设计、数据库设计、模块设计的基本思想,重点介绍了供应商综合评价系统中的基本信息管理、评价指标管理、综合评价与选择模块等关键功能模块的设计方法,以实现对制造型企业供应商的评价与选择。     

A tree-structured crash surrogate measure for freeways

In this paper, we propose a novel methodology to define and estimate a surrogate measure. By imposing a hypothetical disturbance to the leading vehicle, the following vehicle’s action is represented as a probabilistic causal model. After that, a tree is built to describe the eight possible conflict types under the model. The surrogate measure, named Aggregated Crash Index (ACI), is thus proposed to measure the crash risk. This index reflects the accommodability of freeway traffic state to a traffic disturbance. We further apply this measure to evaluate the crash risks in a freeway section of Pacific Motorway, Australia. The results show that the proposed indicator outperforms the three traditional crash surrogate measures (i.e., Time to Collision, Proportion of Stopping Distance, and Crash Potential Index) in representing rear-end crash risks. The applications of this measure are also discussed.     

A Comparative Analysis of Primary and Extreme Characteristics of Dry or Wet Status between Asia and North America

In this study, the Palmer Drought Severity Index (PDSI) was used to analyze the average and extreme dry/wet states of Asia and North America from 1953 to 2003. The results indicate that the two continents underwent drying trends during this period. Compared with North America, Asia showed more severe drought trends. However, more significant and regular seasonal variation for drought was found in North America. The driest regions in Asia were located in the northern region of China, Mongolia, and eastern mid-Siberian plateau. Most regions in central North America were relatively wetter than other regions. The northern and southwestern regions of North America, as well as the Atlantic and Pacific coastal areas, experienced the most drought during this period. A sharp increase of the drought area and the number of extreme drought events took place from 1997 to 2003 in both Asia and North America. Severe drought events were more likely to occur during the summer on both continents. Asia had the most extreme drought events during July, but North America reached its highest drought frequency from June to September. In Asia, a persistent increasing trend of extreme drought emerged throughout the studied period. However, a more complex evolution of drought emerged in North America: a decreasing trend appeared before the mid-1960s and an increasing trend appeared after the late 1970s. A relatively steady dry/wet status was observed between the mid-1960s and the late 1970s. The role of exceptional, extreme drought events with respect to the La Nina event was considered during 1997-2003.     

两自由度并联机构性能指标分析

对两自由度2SPU+U并联机构进行了速度全域性能指标分析,绘出了上述性能指标图谱。针对速度全域性能指标的不足提出线速度全域性能波动指标和角速度全域性能波动指标公式,该指标可更好的反映机构线速度和角速度在整个工作空间内的运动性能波动情况。通过单变量分析法分析了关键部件尺寸变化对机构性能波动指标的影响,得到尺寸变化对机构性能的影响趋势,为机构尺寸选取以及优化设计提供理论依据,该研究对机器人重要结构尺寸的选取以及控制方案的设计有着重要意义。