客专大站到发线运用随机机会约束模型与算法研究

在考虑到发线运用过程中不确定性因素的基础上,研究旅客列车停站时间和接续时间随机变动情况下客专大站到发线运用优化问题,以提高车站作业效率和方便旅客乘降为优化目标,建立了到发线运用的随机机会约束规划模型.通过将模型中的随机机会约束转化为相应的确定性等价形式,从而将随机规划模型转化为确定性模型,并设计了解决该问题的蚁群算法.算例表明该随机机会约束规划模型能取得可靠性更高的到发线运用计划.     

利用频移动态特征的辐射源目标盲分选

利用辐射源目标的频移动态特征进行盲分选时,针对已有的分选方法不能很好解决非合作接收数据非周期、间断、交叠的问题,提出了一种改进的逻辑回归分选算法,将信号分选转化为轨迹分类的问题来处理。首先,借鉴多目标航迹起始模型中的M/N逻辑法的框架,设计新的数据关联门限,以建立目标起始曲线;其次,采用最小二乘拟合方法替代卡尔曼滤波,设计新的外推规则,建立载频变化预测曲线;分析新的接收数据与预测曲线的关联性,不断迭代回归或形成新的分支,最后获得目标分选结果。仿真与实测试验表明,利用逻辑回归分选算法,对不同运动目标搭载的同频辐射源可进行自动分选,4个仿真目标与2个真实目标的分选正确率达到100%。同时,该方法拓展了辐射源目标盲分选中的动态频移特征应用,为辐射源个体识别提供了新的支持。     

高速铁路车站作业计划优化编制方法研究

以高速铁路车站作业总时间最短、设备均衡使用、提高车站作业效率为目标,考虑设备独占性、设备相容性、作业时间范围、作业接续性等相关约束条件,建立了高速铁路车站作业计划编制的0-1整数规划模型.并采用列生成算法来进行求解,以北京南站为例进行实证研究,得出北京南站车站作业计划并对计算结果进行分析,证明了模型和算法的合理性和有效性.     

公共选择理论在完善我国政府投资项目决策机制中的应用

通过对目前我国政府投资项目决策机制中存在问题的分析,借鉴公共选择理论中的宪法经济理论和官僚经济理论的合理思想,提出了完善我国政府投资项目决策机制的具体对策。     

Partial Identification in Monotone Binary Models: Discrete Regressors and Interval Data

We investigate identification in semi-parametric binary regression models, y = 1( x β +υ+ε > 0) when υ is either discrete or measured within intervals. The error term ε is assumed to be uncorrelated with a set of instruments z , ε is independent of υ conditionally on x and z , and the support of − ( x β +ε) is finite. We provide a sharp characterization of the set of observationally equivalent parameters β . When there are as many instruments z as variables x , the bounds of the identified intervals of the different scalar components β _k of parameter β can be expressed as simple moments of the data. Also, in the case of interval data, we show that additional information on the distribution of υ within intervals shrinks the identified set. Specifically, the closer the conditional distribution of υ given z is to uniformity, the smaller is the identified set. Point identified is achieved if and only if υ is uniform within intervals.     

Asymmetric Trading Costs Prior to Earnings Announcements: Implications for Price Discovery and Returns

We show that the cost of trading on negative news, relative to positive news, increases before earnings announcements. Our evidence suggests that this asymmetry is due to financial intermediaries reducing their exposure to announcement risks by providing liquidity asymmetrically. This asymmetry creates a predictable upward bias in prices that increases preannouncement, and subsequently reverses, confounding short‐window announcement returns as measures of earnings news and risk premia. These findings provide an alternative explanation for asymmetric return reactions to firms' earnings news, and help explain puzzling prior evidence that announcement risk premia precede the actual announcements. Our study informs methods for research centering on earnings announcements and offers a possible explanation for patterns in returns around anticipated periods of heightened inventory risks, including alternative firm‐level, industry‐level, and macroeconomic information events.     

复合土钉墙支护的监理控制措施

结合嘉兴江南摩尔工程实例，阐述监理对复合土钉墙支护工程进行事前、事中和事后控制的措施。