Robust single-track train dispatching model under a dynamic and stochastic environment: A scenario-based rolling horizon solution approach

After a major service disruption on a single-track rail line, dispatchers need to generate a series of train meet-pass plans at different decision times of the rescheduling stage. The task is to recover the impacted train schedule from the current and future disturbances and minimize the expected additional delay under different forecasted operational conditions. Based on a stochastic programming with recourse framework, this paper incorporates different probabilistic scenarios in the rolling horizon decision process to recognize (1) the input data uncertainty associated with predicted segment running times and segment recovery times and (2) the possibilities of rescheduling decisions after receiving status updates. The proposed model periodically optimizes schedules for a relatively long rolling horizon, while selecting and disseminating a robust meet-pass plan for every roll period. A multi-layer branching solution procedure is developed to systematically generate and select meet-pass plans under different stochastic scenarios. Illustrative examples and numerical experiments are used to demonstrate the importance of robust disruption handling under a dynamic and stochastic environment. In terms of expected total train delay time, our experimental results show that the robust solutions are better than the expected value-based solutions by a range of 10-30%.     

基于云模型的装备研制项目中止决策方法

装备研制项目是一项复杂的系统工程,其实施前景不确定,科学及时地中止没有前景的研制项目对于优化国防资源配置有重要意义。针对目前中止决策方法中的定性方法主观性大,而定量方法损失信息较多的问题,引入了云理论,通过云变换把定性评语转化为评价云,建立了云决策模型。     

基于期望效用准则战场目标分配决策研究

文章通过分析影响目标价值的指标,构建火力分配决策模型,研究基于期望效用准则的战场目标分配决策方案模型,提出其分析步骤和方法,科学计算期望效用,较大程度上降低了决策的风险程度,具有一定的科学性和实用性,该方法为战场目标分配决策方案的选择提供理论依据。     

舰载光电对抗系统作战仿真方法研究

该文针对舰载光电对抗系统作战仿真需求出发,首先建立了舰载光电对抗作战双方和虚拟战场环境的模型,然后开展了作战仿真试验,试验结果证明战术应用软件提交的作战方案可行,实现了多种光电对抗手段综合运用的目的,具备指挥光电对抗设备开展光电对抗作战的能力。该文所描述的仿真方法适用于评价舰载光电对抗系统作战决策方案。     

导航系统异步串口通信协议参数智能检测算法研究

针对某些舰船导航装备所采用的异步串口通信协议参数不明确,无法正常和其他设备通信的现象,提出了一套基于单片机采集电平数据,计算机对采样数据进行解析的异步串口通信协议参数自动检测方法。依次阐述了对波特率、数据位长度、校验方式以及数据编码方式的解析算法。经实践结果表明,该方法运行速率快、正确率高,是检测异步串口通信协议参数的可靠方法。     

海洋环境监测是海洋发展和维权的支撑

海洋维权装备必须适应海洋环境,海洋环境又无休止地影响着海洋装备的功能和性能.要想提高装备技术水平,发挥装备的最大效能,在应用和研制装备的同时,要充分了解海洋环境对装备的诸多影响,要研究海洋环境与装备相关性技术.本文根据海洋维权装备发展顶层设计的需求,从功能上定性地探讨分析海洋环境对雷达探测、水声探测、目标识别、精确制导、信号传输、导航定位等方面的影响,提出海洋维权装备对海洋环境的适应性要求和对海洋环境效应技术的支撑性需求,提出把海洋环境监测要素纳入海战场辅助决策体系.海洋环境监测既是人类认知海洋、开发海洋、防灾救灾、海战场建设的需要,又是海洋发展和维权的支撑和先导,军民共建,军民共享,为发展海洋经济,保护海洋权益而励志奋进!     

Predicting arterial breakdown probability: A data mining approach

Predicting the probability of traffic breakdown can be used as an important input for creating advanced traffic management strategies that are specifically implemented to reduce this probability. However, most, if not all, past research on the probability of breakdown has focused on freeways. This study focuses on the prediction of arterial breakdown probability based on archived traffic data for use in real-time transportation system operations. The breakdown of an arterial segment is defined in this study as a segment's operating condition under the level of service F according to the highway capacity manual threshold, although any other level of service could be used. Data from point detection and automatic vehicle identification matching technologies are aggregated in space and time to allow their use as inputs to the prediction model. A decision tree approach, combined with binary logistic regression, is used in this study to predict the breakdown probability based on these inputs. The model is validated using data not used in the development of the model. The research shows that the root mean square error and the mean absolute error of the prediction was 13.6 and 11%, respectively. The analysis also shows that the best set of parameters used in the prediction can be different for different links, due to the various causes of breakdown and characteristics of different links. Predicting the probability of breakdown in ahead of time will allow the agencies to change the signal-timing plan that can delay or eliminate the breakdown.     

基于MDDP系统的智能压机线开发

冲压压力机作为汽车制造行业表面件加工的设备,具有多工况,变载荷、重载荷的特点,在零件加工过程中需要持续往复运行。随着设备的负荷不断增大使用年限地不断增长,一些大型的机械故障也因为磨损、疲劳以及维护保养不及时彻底等因素而开始出现,且出现频次逐渐增高。在既有的正常点巡检和例行检修保养的前提下,一些故障和问题仍无法及时发现或提前预判,从而造成了大量的非计划停机时间、人工成本、备件成本的投入。为此,引入了智能设备的概念,开发MDDP系统,实现设备自主监控、诊断、决策和预测。     

Measuring the sustainability of marine fuels: A fuzzy group multi-criteria decision making approach

The use of alternative energy sources instead of HFO has been recognized as a promising way for reducing emissions from shipping and promoting the development of green shipping. However, it is usually difficult for the decision-making to select the best choice among multiple alternative marine fuels. In order to address this, a complete criteria system for sustainability assessment of alternative marine fuels was firstly established, and a fuzzy group multi-criteria decision making method has been developed to rank the alternative marine fuels by combining fuzzy logarithmic least squares and fuzzy TOPSIS (Technique for Order Performance by Similarity to Ideal Solution). Fuzzy logarithmic least squares method has been employed to determine the weights of the criteria for sustainability assessment, and fuzzy TOPSIS was employed to determine the sustainability order of the alternatives. An illustrative case with three alternative marine fuels including methanol, LNG and hydrogen has been studied by the proposed method, and hydrogen has been recognized as the most sustainable scenario, follows by LNG, and methanol in the descending order. The results show that the proposed method is feasible for prioritizing the alternative marine fuels; it also has the ability to help the decision-makers to select the most sustainable option among multiple marine fuels.     

Crying wolf: Repeat responses to hurricane evacuation orders

This article examines the evacuation behavior of residents in two South Carolina communities, Hilton Head and Myrtle Beach, during the 1996 hurricane season. Two hurricanes that approached South Carolina but hit in North Carolina allowed us to study the impact of repeated “false alarms”; (evacuations ordered based on expectations of a hurricane landfall that proved to be wrong). Differences in evacuation behavior, specific information and concerns prompting evacuation, and the reliability of information sources between hurricane events are examined to determine the impact of false alarms on the credibility of warning systems. Data were derived from a face‐to‐face survey of residents 2 weeks after Hurricane Fran in September 1996. We found that the role of official advisories was more limited than reported in previous research as people sought information on more diverse sets of concerns in their decision making. Reliance on the media and the Weather Channel, in particular, for storm characteristics and advisories was an important factor in evacuation decision making during both hurricane events. The perceived lack of reliability of gubernatorial warnings coupled with dependence on the media suggests that residents find other sources of information more personally relevant. Thus, while residents do not find that officials are “crying wolf,”; they are searching elsewhere for information to assess their own risk—what does it mean to me if there is a wolf? This increased attention toward individual differences in perceived threat may become more pronounced in future evacuations from hurricanes.