基于复合预测控制的并联有源电力滤波器研究

通过建立线性预测数学模型,分析了线性预测的不稳定性和差一拍控制对谐波补偿输出的影响,提出了将线性预测与记录一周期谐波电流采样点作为后续预测电流相复合的无差拍控制,消除了采样与计算延时对系统的影响。仿真结果表明,平均滤波器应用于ip-iq谐波电流检测算法中,谐波检测精度较高、响应速度较快;采用复合无差拍控制,对谐波抑制与无功补偿有较好的稳态精度和动态响应速度。在整体上提高了并联有源电力滤波器的谐波抑制与无功补偿性能。     

运行速度理论在山地城市快速路设计中的应用

介绍了现行以计算行车速度为依据的城市快速路设计方法存在的局限性,提出基于运行速度的设计方法和设计流程,为山地城市快速路几何设计指标选取和运行速度设计方法的应用提供参考。     

珠三角腹地软基十字板与静探试验成果的相关性研究

在原位十字板与静探数据的相关性分析中,考虑研究范围内土体强度可分别由两种测试数据独立线性表达,找出两种试验指标的等式,将试验参数综合考虑,建立多元线性回归方程,通过大量试验数据并借助数学软件对回归方程进行求解。通过实例分析,验证两种试验关系的准确性,为今后的勘察与研究提供参考和新的方法。     

基于免疫遗传算法的水下无人平台航路规划

为克服遗传算法在水下无人平台航路规划应用中存在的问题,提出了基于免疫遗传算法的水下航路规划问题.仿真结果表明,这种算法能够有效地提高航路规划的计算速度和保证航路规划的质量.     

动态分段技术在高速公路应急救援指挥系统中的应用

动态分段技术是一项新的线性特征的存储、显示和分析技术,在建立高速公路应急救援指挥系统的过程中,有很多事件的处理过程涉及到了针对线状道路的属性定位问题。文中介绍了动态分段技术的基本概念和基本原理,并结合实际介绍了动态分段技术在高速公路应急救援指挥系统中的应用实例,包括事故定位、影响分析、路况查看等多项问题。使用ArcGIS Server组件与.NET平台实现了基于动态分段技术的高速公路应急救援指挥系统,表明动态分段技术在该系统中的适用性。     

江水北调优化调度模型的研究

从江水北调水资源系统的实际情况出发,建立了确定型的优化调度数学模型,提出一种灵活性较强又能较好地解决实际问题的求解方法,即逐次优化算法(POA)的目标规划,同时编制了计算软件,并给出有益的结论。     

The time-dependent pollution-routing problem

The Time-Dependent Pollution-Routing Problem (TDPRP) consists of routing a fleet of vehicles in order to serve a set of customers and determining the speeds on each leg of the routes. The cost function includes emissions and driver costs, taking into account traffic congestion which, at peak periods, significantly restricts vehicle speeds and increases emissions. We describe an integer linear programming formulation of the TDPRP and provide illustrative examples to motivate the problem and give insights about the tradeoffs it involves. We also provide an analytical characterization of the optimal solutions for a single-arc version of the problem, identifying conditions under which it is optimal to wait idly at certain locations in order to avoid congestion and to reduce the cost of emissions. Building on these analytical results we describe a novel departure time and speed optimization algorithm for the cases when the route is fixed. Finally, using benchmark instances, we present results on the computational performance of the proposed formulation and on the speed optimization procedure.     

高性能混凝土配合比设计方法研究

结合重庆石板坡长江大桥复线桥高性能混凝土应用研究,应用数值分析方法回归得到了高性能混凝土28 d立方体抗压强度与胶凝材料比例、水泥强度、胶水比的多元线性关系,为高性能混凝土配合设计提供了参数计算的依据。     

Nonlinear programming methods based on closed-form expressions for optimal train control

This paper proposes a novel approach to solve the complex optimal train control problems that so far cannot be perfectly tackled by the existing methods, including the optimal control of a fleet of interacting trains, and the optimal train control involving scheduling. By dividing the track into subsections with constant speed limit and constant gradient, and assuming the train’s running resistance to be a quadratic function of speed, two different methods are proposed to solve the problems of interest. The first method assumes an operation sequence of maximum traction – speedholding – coasting – maximum braking on each subsection of the track. To maintain the mathematical tractability, the maximum tractive and maximum braking functions are restricted to be decreasing and piecewise-quadratic, based on which the terminal speed, travel distance and energy consumption of each operation can be calculated in a closed-form, given the initial speed and time duration of that operation. With these closed-form expressions, the optimal train control problem is formulated and solved as a nonlinear programming problem. To allow more flexible forms of maximum tractive and maximum braking forces, the second method applies a constant force on each subsection. Performance of these two methods is compared through a case study of the classic single-train control on a single journey. The proposed methods are further utilised to formulate more complex optimal train control problems, including scheduling a subway line while taking train control into account, and simultaneously optimising the control of a leader-follower train pair under fixed- and moving-block signalling systems.