浅析矿山生产能力确定及优化

矿山生产能力确定是矿山生产能否形成最大利润的重要指标,因其影响因素较多,在用传统的方法上不可能所有因素都能考虑,为实现诸因素综合影响,只有从灰色信息系统来达到。通过灰色系统决策—灰色效果测量建模;层次分析—层次结构建模;最后的灰色决策达到优化。该方法考虑了决策中的诸影响因素,根据各因素的权重进行灰色定量决策,理论上更具有科学性。     

Assessment of non-recurrent congestion caused by precipitation using archived weather and traffic flow data

Since precipitation has a negative impact on traffic congestion, there have been various studies for modeling the relationship between precipitation and its impact on traffic flow. However, due to limitations on existing data, none of the previous studies have accounted for the estimation of the total delay caused by precipitation. The objective of this study is to estimate the non-recurrent traffic congestion on freeways caused by precipitation. To accomplish this objective, archived weather and traffic data for the year 2008 from the Korean Freeway Systems was collected and analyzed. As a result, non-recurrent traffic congestion was about 1.6 million vehicle-hours due to rainfall and 186,000 vehicle-hours due to snowfall in 2008. In addition, simple analyses were performed to describe the average non-recurrent traffic congestion per unit distance as a function of precipitation and a function of the time period of precipitation. Although precipitation events might not be handled by human efforts, these results will assist in making strategic plans such as active speed management and contingency planning for mitigating traffic congestion due to precipitation.     

Capacity Constraints and Hedge Fund Strategy Returns

Hedge funds have generated significant absolute returns (alpha) in the decade between 1995 and 2004. However, the level of alpha has declined substantially over this period. We investigate whether capacity constraints at the level of hedge fund strategies have been responsible for this decline. For four out of eight hedge fund strategies, capital inflows have statistically preceded negative movements in alpha, consistent with this hypothesis. We also find evidence that hedge fund fees have increased over the same period. Our results provide support for the Berk and Green (2004) rational model of active portfolio management.     

我国铁路集装箱运输中存在的问题与对策研究

铁路集装箱运输在我国铁路货运中的地位起来越重要，但由于我国铁路集装箱运输起步较晚，还存在很多不足之处。分析了我国铁路集装箱运输中存在的问题，并对我国铁路集装箱运输发展的对策进行了探讨。     

铁路双线自动闭塞区间通过能力计算方法研究

铁路区间通过能力计算方法的研究,对于铁路运输事业的发展有着重要作用。依据直接计算法的思想,结合具体的运行图铺画,建立铁路双线自动闭塞区间通过能力计算模型,并利用该模型求解郑武客运专线新郑州到新许昌段的通过能力,通过实例验证明该模型的有效性。     

国外乙丙橡胶生产及市场供需趋势

介绍了国外 乙丙橡胶的生产现状以及北美，南美，西欧和亚洲地区的市场供需趋势。     

东亚地区石化业的现状与趋势

叙述东亚地区石化生产能力的扩充、石化产品供需的平衡、市场竞争的加剧以及产品盈利的前景。分别介绍新加坡、印尼、泰国、韩国和中国台湾省石化业的现状与趋势。     

浅析地基承载力特征值的深度修正

影响地基承载力特征值修正的因素较多，文章通过对地基破坏形式的分析得出地基承载力深度修正的实质，并分析不同情况下地基承载力深度修正时基础埋深的取值。     

兰州市公用机械式立体停车库规划研究

随着经济的快速发展。停车难成为城市发展中一个亟待解决的问题，机械式立体停车库是城市停车场的一种形式，具有占地面积小、空间利用率高等优势，在当前城市用地资源日趋紧张的情况下，从城市交通总体角度规划一定数量的公共类机械式立体停车库，缓解城市交通压力。文章以兰州市重点区域为例，分析了城市机械式立体停车库应用规划研究，并对兰州市重点区域进行了具体规划，以推动停车科技产业发展。可有效缓解兰州市停车难现状。     

北京交通拥堵的五种成本分析

以科学发展观为指导，以发展现代交通业为目标，以实现民众的福祉为宗旨，着眼于解决城市交通拥堵问题，促进我国交通事业的又快又好发展。本研究从拥堵经济成本（JEC）、社会成本、环境成本、健康成本与焦虑成本五种分析，试图解读交通拥堵对经济社会带来的伤害。