无标底招投标的Nash均衡模型及GA算法实现

在分析现有无标底招投标规则的基础上,采用一般对象化方法,建立无标底招投标报价问题的无协作形式Nash均衡模型.在招投标报价中引入智能算法思想,运用并行选择遗传算法进行求解,并通过双矩阵的实例验证了该算法的有效性.     

A hybrid approach to integrate fuzzy C-means based imputation method with genetic algorithm for missing traffic volume data estimation

Although various innovative traffic sensing technologies have been widely employed, incomplete sensor data is one of the most major problems to significantly degrade traffic data quality and integrity. In this study, a hybrid approach integrating the Fuzzy C-Means (FCM)-based imputation method with the Genetic Algorithm (GA) is develop for missing traffic volume data estimation based on inductance loop detector outputs. By utilizing the weekly similarity among data, the conventional vector-based data structure is firstly transformed into the matrix-based data pattern. Then, the GA is applied to optimize the membership functions and centroids in the FCM model. The experimental tests are conducted to verify the effectiveness of the proposed approach. The traffic volume data collected at different temporal scales were used as the testing dataset, and three different indicators, including root mean square error, correlation coefficient, and relative accuracy, are utilized to quantify the imputation performance compared with some conventional methods (Historical method, Double Exponential Smoothing, and Autoregressive Integrated Moving Average model). The results show the proposed approach outperforms the conventional methods under prevailing traffic conditions.     

基于最小浮动车样本数量的道路覆盖率与交通信息更新周期研究

基于浮动车样本数量的道路覆盖率与交通信息更新周期的关系是浮动车信息采集技术应用中亟待解决的关键问题。浮动车的道路覆盖率与交通信息更新周期之间成正比关系,通过对基于经典概率统计理论的传统计算最小浮动车样本数量方法中所存在不足的分析,提出从路段内车辆运行时间角度出发考虑样本量,引入表征运行时间变化的变量,确定满足道路覆盖率的最小浮动车样本数量,进而建立基于浮动车样本数量的道路覆盖率与交通信息更新周期的关系模型,并给出满足道路覆盖率的浮动车最小样本数量计算的改进算法。通过成渝高速公路成都—龙泉段的实际浮动车数据,验证了关系模型的可靠性及改进算法的优越性。     

铁路轨道不平顺预测模型研究与应用

在保障列车行车安全的前提下提高维修效率和减少经济开支具有重要意义。为此,利用综合轨道检测车检测的历史轨道不平顺动态检测数据TQI值进行科学合理的分析,建立一种基于数据选择向量的非等时距灰色模型和神经网络理论相结合的预测方法,对实际线路轨道不平顺值进行预测,相对误差分别为2.63%、2.516%和2.025%。将预测模型应用在年度轨道状态最优综合维修计划的编排中,以养护维修时间和维修地点为决策变量,以年度轨道不平顺平均值最小为目标函数,在考虑了一系列约束函数的情况下,建立了利用遗传算法求解最优解的辅助决策模型。实验结果表明,该方法提高了预测精度,具有较好的实用性,能够快速地编排出线路的年度养护计划。     

基于单分类算法OSVM船用燃气轮机状态评估

针对船舶综合监控系统中存储有海量设备正常运行时的数据没有得到充分利用，此外设备退化时的故障数据难以获取，无法训练传统的多分类退化检测模型，提出利用单分类算法OSVM来建立模型,从而实现退化检测，在该过程中只需用正常样本数据来训练模型，并在一个经过实船数据验证过的模拟器产生的数据集上进行了实验。结果显示，只需要400个正常样本就可训练出准确的退化检测模型，该模型在精确度，召回率，特异性，正确率，AUC五个指标都有很好表现，此外，该退化检测模型有很好的扩展性，也可被用于其他机械设备的状态评估中。     

Single track line capacity model

The objective of the research described in this paper was to develop a model for computation of an ultimate capacity of a single track line and to provide a sensitivity analysis of this capacity to the parameters which influence it. The model is based in a concept of mathematical expectation of capacity and can be applied under saturation conditions i.e. a constant demand for service. It can serve for planning purposes, computation of single track line capacity on the base of which estimations are possible concerning a single track line performance under given conditions, as well as commercial time‐tables planning, decisions about a partial or complete construction of the second parallel track along the line in service, intermediate stations locations planning and the necessary facilities along the line under construction.

In the sensitivity analysis, the model allows a change of parameters upon which the capacity depends. These are: the length of the line segment which is considered to be bottleneck for calculation of capacity, traffic distributions per directions, train mix, train velocities and train spacing rules applied by the dispatching service when regulating the traffic on a line.     

Hinge joint damage identification method of soft yoke mooring system based on multibody dynamic modeling and structural monitoring data

Soft yoke mooring system (SYMs) is a single-point mooring system used in shallow water oil and gas development. In general, SYMs consists of mooring framework support, mooring legs, yoke, and single-point turret and it forms a multibody dynamic system with 13 hinge joint structures such as universal joints and thrust bearings. The hinge joint is one of the key components of SYMs; therefore, it is necessary to accurately evaluate the operating behavior of the hinge joints. In this study, real-time damage identification is conducted based on the multibody dynamic features of the SYMs. First, a long-term monitoring strategy for the prototype application is developed based on the multibody governing equations of the SYMs. The motion behaviors and stress state of the hinge joints and bodies are calculated using prototype monitoring data. A hinge joint damage identification based on the virtual moment is proposed by considering the changes in the friction coefficient in the damage state. The virtual moment method is used to transform the damage identification problem of the SYMs into a problem of seeking the optimal solution to the dynamics identification function. Genetic algorithm (GA) is implemented to seek the optimal solution of the friction coefficient of each hinge joint. A large-scale model testing system of the SYMs is established to perform the damage identification of the bottom hinge joints of the SYMs. The results show that the proposed method can effectively identify the damage degree and position of the hinge joints of the SYMs and provide a real-time warning system for the in-service operation of the SYMs.     

Assessing transportation user benefits with maximum trip lengths

Maximum time lengths of urban trips can be used to calculate major user benefits of transportation improvements. These benefits include those associated with reduced cost of travel, those associated with travel to additional destinations, and those associated with improved quality of destinations. Maximum trip lengths can be measured using techniques of psychological scaling.     

Charging infrastructure planning for promoting battery electric vehicles: An activity-based approach using multiday travel data

This paper studies electric vehicle charger location problems and analyzes the impact of public charging infrastructure deployment on increasing electric miles traveled, thus promoting battery electric vehicle (BEV) market penetration. An activity-based assessment method is proposed to evaluate BEV feasibility for the heterogeneous traveling population in the real world driving context. Genetic algorithm is applied to find (sub)optimal locations for siting public charging stations. A case study using the GPS-based travel survey data collected in the greater Seattle metropolitan area shows that electric miles and trips could be significantly increased by installing public chargers at popular destinations, with a reasonable infrastructure investment.     

CTCS-2级列控系统地面应答器布置算法

简要介绍了既有线提速200km／h的CTCS-2级列控系统地面应答器布置规则，以及胶济线、浙赣线对此规则的工程运用。在此基础上，提出一个应答器合理布置的算法，阐述了该算法的实现过程。