码头堆场龙门起重机动态配置优化模型

为了优化轮胎式龙门起重机的动态配置,建立一个多目标非线性数学规划模型,以各箱区总的未按计划完成工作箱量所需的龙门起重机时间和龙门起重机闲置时间的最小化为目标函数,采用基于启发式方法的Lagrangian松弛算法,求取轮胎式龙门起重机的动态配置近似最优解。算例测试表明,算法的平均相对对偶间隙为1％,平均计算时间为4min,这种方法对于港口堆场内轮胎式龙门起重机的动态优化配置是有效的。     

基于Lagrangian算法的目标跟踪与信息融合效果评估

指挥自动化系统（C4ISR）作为现代战争中对作战部队和武器系统实施高效指挥与控制的主要手段,通过对来自多个传感器的资料以及相关情报进行分析和综合处理,研究复杂战场态势环境下的指挥自动化系统目标跟踪与信息融合的效果评估。用Lagrangian算法得到评价体系中定义的性能指标,并根据这些指标进行综合评估,提高系统的有效性和可靠性。     

观测路径出行时间下随机网络交通需求估计

道路网络起讫点(OD)需求是城市决策长期交通规划和短期交通管理中的基础参数,准确的交通需求更是实施交通拥堵控制、限行限速、路径诱导等措施的先决条件.综合运用观测的轨迹已知和未知路径出行时间,建立随机网络交通需求估计双层规划模型.上层广义最小二乘模型最小化历史交通需求与待估交通需求、观测路径出行时间与待估路径出行时间之间...     

Evolution of the open-sea eddy ALGERS'98 in the Algerian Basin with Lagrangian trajectories and remote sensing observations

The westward evolution of an open-sea anticyclonic eddy along the western Algerian Basin is shown, for the first time, by means of 15 buoy trajectories and remote sensing observations. For 3 months, the buoy trajectories described several anticyclonic loops in periods of 4–21 days. The eddy's movement, translation, and rotation were separated with a kinematic model, resulting in a mean translation speed of 2 km/day, which fits the self-propulsion speed predicted on theoretical models for isolated eddies on a beta plane. Fluctuations in translation speed were associated with advection of the mean flow and topographic interactions. Both mechanisms changed the eddy's horizontal shape from circular to elliptical, inducing fluctuations in its swirl velocity and solid-body rotation. The initial stage of the eddy is an isolated asymmetric dipole, comprised by a small cyclone and a large anticyclone, the latter generated from a frontal instability, which under the Coriolis term acquires anticyclonic relative vorticity. During its first days of life, the anticyclonic eddy was shallow Ro=0.9 and small (diameter less than 50 km). Later on, it reached a diameter of 150 km and a vertical structure of 3 km (Ro=0.1). A retrospective analysis with infrared images shows that the eddy's generation took place at about 3–4°E. Then, the eddy completed a counterclockwise circuit never before reported in other studies and ended up at the entrance of the Algerian Basin, where the interaction with the topography and the coastal instability induced its decay. The eddy's life span was 10 months. Computations of the heating rate following clusters of buoy trajectories show fluctuations throughout the eddy's journey, induced by advection and a seasonal warming.     

反舰导弹弹道攻击模式及其战术运用

反舰导弹利用机动弹道是提高突防能力、增强攻击效果的重要措施.论文从导弹弹道运用的角度,归纳了目前世界主要先进反舰导弹的典型攻击模式,并阐述了低弹道、高弹道、复合弹道三种典型攻击模式的基本特征,进而分析了不同弹道攻击模式下导弹的突防能力.最后依据不同弹道攻击模式的优势和不足,对导弹弹道运用的制约因素、使用时机、协同方式等三个方面进行了分析和总结.     

The method of imbedded Lagrangian element to estimate wave power absorption by some submerged devices

A simple approach is described to estimate the wave power absorption potential of submerged devices known to cause wave focusing and flow enhancement. In particular, the presence of a flow-through power take-off （PTO） system, such as low-head turbines, can be accounted for. The wave radiation characteristics of an appropriately selected Lagrangian element （LE） in the fluid domain are first determined. In the limit of a vanishing mass, the LE reduces to a patch of distributed normal dipoles. The hydrodynamic coefficients of this virtual object are then input in a standard equation of motion where the effect of the PTO can be represented, for example, as a dashpot damping term. The process is illustrated for a class of devices recently proposed by Carter and Ertekin （2011）, although in a simplified form. Favorable wave power absorption is shown for large ratios of the LE wave radiation coefficient over the LE added mass coefficient. Under optimal conditions, the relative flow reduction from the PTO theoretically lies between 0.50 and 1 2 ≈ 0.71, with lower values corresponding to better configurations. Wave power capture widths, the sensitivity of results to PTO damping and sample spectral calculations at a typical site in Hawaiian waters are proposed to further illustrate the versatility of the method.     

面向鲁棒性的高速铁路网络列车运行调整计划优化模型

针对高速铁路路网中出现区间封锁事件,考虑事件持续时间的不确定性,以列车运行时间和安全间隔时间为约束条件,引入路径选择唯一性约束保证列车运行调整计划的鲁棒性,以所有列车晚点时间之和的期望值最小为目标函数,建立高速铁路列车运行调整计划优化整数规划模型.设计基于优先级规则的启发式算法,求解原模型的可行解.运用拉格朗日松弛算法和最短路径算法求解该模型的松弛模型,得到原模型最优解的下界.根据可行解与最优解下界之间的距离,可以定量地衡量可行解的质量.结果表明,相较于CPLEX数学求解软件,算法求解效率较高;模型与算法能够有效生成鲁棒的列车运行调整计划,为调度员提供必要辅助决策信息.     

一个鲁棒性冲突解脱轨迹规划模型

针对固定航路飞行条件下高密度运行空域多航空器实时冲突解脱轨迹规划问题,为了获取高空风场数值及增强航空器冲突解脱轨迹的鲁棒性,根据航空器的运行状态构建了高空风场线性和非线性滤波模型.采用模型预测控制理论,通过将预测模型的校正过程转化为高空风场数值的滤波过程,在给各航空器设定解脱优先权重及考虑两类解脱变量物理约束条件的前提下,从航空器的动态协同特性出发,构造能够反映控制输入量优劣的指标函数,提出一种能够适应空域环境变化的冲突解脱航迹在线滚动规划方案.算例分析表明,所提出的在线解脱轨迹规划方案可行有效.     

An augmented Lagrangian origin‐based algorithm for link‐capacitated traffic assignment problem

The origin‐based algorithm is embedded into the augmented Lagrangian method for the link‐capacitated traffic assignment problem. In order to solve the “nonexistence” problem due to the second partial derivatives of the augmented Lagrangian function at some specific points, the approximate expressions of the second partial derivatives are amended in the origin‐based algorithm. The graph of last common nodes is developed on the basis of the restricted single‐origin network. A method is proposed for finding n–1 last common nodes of the restricted single‐origin network, resulting in computational complexity of O(n²) in finding last common nodes. Numerical analysis on the Sioux Falls network and Chicago Sketch network demonstrated the effectiveness and characteristics of the proposed algorithm. Copyright © 2014 John Wiley & Sons, Ltd.     

A lane-change trajectory model from drivers’ vision view

Car-following and Lane-changing are two fundamental tasks during driving. While many car-following models can be applied, relatively, only a few lane-changing models have been developed. Classical lane-changing models mainly focus on drivers’ lane selection and gap acceptance behaviors, but very limited research has paid attention to formulating detailed lane-changing trajectories. This research aims to fill the gap by proposing a lane-changing trajectory model, which is built directly from drivers’ vision view, to model detailed lane-changing trajectories. A large amount of data of reference angles, defined as the angle changes between the drivers’ vision angle and left or right lane line, were first extracted from the videos recorded by the vehicle traveling data recorders (VTDRs) installed in 11 taxies. A comprehensive data analysis indicates that same drivers show similarity of their daily lane-changing habit but with variety, and different drivers’ lane-change trajectory data show different lane-change “personality” including aggressive or non-aggressive behaviors. Based on these findings, this paper then proposed a hyperbolic tangent lane-change trajectory model to describe drivers’ detailed lane-change trajectories. The model is verified using both real data and simulation. The results show the proposed lane-change trajectory model can successfully describe drivers’ lane-changing trajectories. More importantly, some parameters in the model are directly associated to drivers’ driving characteristics during lane-change. With this unique feature, the proposed model can generate driver-specific lane-change trajectories. Such improvement could contribute to the future development of Advanced Driver Assistance Systems (ADAS).