求解作业车间批量流问题的变邻域搜索算法

对具有等子批和空闲约束的作业车间批量流问题进行了研究,提出一种有效变邻域搜索（VNS）算法以最小化延迟和提前惩罚总和,该算法利用双串表示法描述问题的解.为了适应问题的特点,几个初始解独立进化以改善VNS的探索能力,对批调度采用一个变邻域结构,而对批量流条件则根据一个较小的概率进行调整.将VNS应用于一些实例,计算结果验证了VNS的优异性能.     

无人机在海上搜救中的应用探索

文中以无人机在搜救行动中承担的任务角色不同,分别探索无人机在实现搜寻定位、远距离视频传输和救援物资投放任务的原理和实现方式。     

UUV操纵性能综合优化模型研究

操纵性能是无人潜器（UUV）航行的重要性能之一,其优劣直接影响到UUV的航行安全和稳定性,UUV操纵性能评判和优化是UUV优化设计的重要组成部分.基于AUTOSUB型无人潜器的设计模型,在充分分析艇体操纵性能的基础上,重点研究UUV水平运动和垂直运动性能,提出了较为完备的UUV操纵性能优化数学模型.采用模糊评判方法构造操纵性系统总目标函数,利用专家咨询法确定了各子系统的权重;通过大量艇体操纵性能数据对各个性能指标进行统计分析,选择模糊数学中对应的隶属度函数进行拟合,确定相应隶属度函数参数;利用禁忌搜索算法对遗传算法的改进而得到的遗传禁忌搜索算法（GA-TS）,由并行和分层策略改进遗传算法得到的并行遗传算法（PGA）以及遗传二次载波算法（LGA）,将数学模型与这3种算法集成,利用C＋＋语言编写了UUV操纵性能优化软件.通过对总系统优化得到的遗传禁忌搜索算法寻优能力最强,利用该算法研究水平面运动和垂直面运动2个子系统,得到各个性能指标权重对系统目标函数影响程度的排序,同时分别得到-组最佳性能的权重分配.     

Quadratic approximation and convergence of some bush-based algorithms for the traffic assignment problem

This paper first shows that LUCE (Gentile, 2012), a recent addition to the family of bush-based algorithms, is closely related to OBA (Bar-Gera, 2002). LUCE’s promise comes mainly from its use of the greedy method for solving the quadratic approximation of node-based subproblems, which determines the search direction. While the greedy algorithm accelerates the solution of the subproblems and reduces the cost of line search, it unexpectedly disrupts the overall convergence performance in our experiments, which consistently show that LUCE failed to converge beyond certain threshold of relative gap. Our analysis suggests that the root cause to this interesting behavior is the inaccurate quadratic approximation constructed on faulty information of second-order derivatives. Because the quadratic approximations themselves are inaccurate, the search directions generated from them are sub-optimal. Unlike OBA, however, LUCE does not have a mechanism to correct these search directions through line search, which explains why its convergence performance suffers the observed breakdowns. We also attempt to improve LUCE using the ideas that have been experimented for the improvement of OBA. While these improvements do work, their effects are not enough to counteract the inability to adjust sub-optimal search directions. Importantly, the fact that the search direction has to be corrected in line search to ensure smooth convergence attests to the limitation of origin-based flow aggregation shared by both OBA and LUCE. These findings offer guidelines for the design of high performance traffic assignment algorithms.     

基于可靠性最短路的实时定制公交线路优化研究

为实时优化定制公交线路，提出一种基于可靠性最短路的线路优化方法，在复杂的交通环境中，可以高效的将乘客送达目的地. 对可靠性最短路进行问题描述，建立可靠性时空网络；给出求解可靠性最短路的算法步骤，构建乘客和定制公交运营商总成本最小的目标函数，采用禁忌搜索算法对问题进行求解；最后，以某市定制公交路网进行实例分析. 结果表明：与最短路线路方案比较，所提方法更接近于实际运营；在高峰时段，交通拥堵的情况下，所提方法可以提高车辆的可靠性，提升定制公交线路的服务水平.     

Cooperative path following control of UAV and USV cluster for maritime search and rescue北大核心CSCD

［Objectives ］ This paper studies a three-dimensional (3D) cooperative path-following control problem in the process of maritime search and rescue for a heterogeneous unmanned cluster system composed of unmanned aerial vehicles (UAVs) and unmanned surface vehicles (USVs).［Methods ］ First, kinematic models of the UAVs and USVs are established under a fixed coordinate system and body coordinate system. In order to design a 3D path-following controller suitable for motion control, an air coordinate system is established, and the path tracking error models of the UAVs and USVs are established in the Serret-Frenet coordinate system. Next, a 3D line-of-sight (LOS) guidance law is designed at the kinematic level, and a cooperative path-following control method suitable for heterogeneous clusters of marine vehicles is proposed, allowing the UAVs and USVs to track the preset parameterized path. Finally, the stability of the control system is analyzed based on the Lyapunov stability theory.［Results］The simulation results verify the effectiveness of the proposed cooperative path-following control method for heterogeneous clusters of marine vehicles.［Conclusions］The results of this study can provide references for maritime search and rescue by using the proposed cooperative path-following control method. © 2022 Journal of Clinical Hepatology. All rights reserved.     

面向层次资质的机场外航服务人员排班研究

机场外航服务人员排班是机场智能调度系统的重要组成.针对目前我国机场外航服务人员排班主要采用人工方式，排班效率低下，员工工作时间均衡性不高，且难以满足多种类约束这一现状，本文充分考虑员工对任务具有层次资质及各类劳动法规约束，以均衡员工工作时间为优化目标，提出了面向层次资质的机场外航服务人员排班模型，并设计了基于禁忌搜索算法的模型求解策略.在首都机场外航服务部实际数据集上进行实验，验证结果表明，相比较于现有人工排班方案，利用本文模型得到的排班方案能满足所有排班约束条件，且在员工工作时间均衡性上有显著提高.     

一种基于时空距离的带时间窗车辆路径问题算法

带时间窗的车辆路径问题是典型的NP难题,一种常用的求解方法是先对顾客分组,后进行路径优化的两阶段启发式算法. 传统算法在顾客分组时主要考虑顾客的空间位置关系,但是忽略了顾客对服务时间窗口的要求. 本文同时考虑顾客的时间和空间特性,提出了一种基于时空度量的顾客分组方法. 在路径优化阶段,本文提出了一种禁忌搜索算法来进行求解,该算法中禁忌的对象不是解,而是这些解的目标函数值的区间,以便于提高收敛效率. 作为验证,本文以Solomon标杆问题集为算例进行演算,结果表明,在窄时间窗约束下,基于时空距离的两阶段启发式算法明显优于基于空间距离的算法,且部分算例的解达到了国内外已发表的最好解.     

基于数据库的动态路径寻优算法与实现

为适应当今数据存储和处理的需要,在路径寻优算法的实际应用过程中可以充分利用数据库管理数据的功能。利用实时动态的交通信息,寻找动态实时的最优路径,建立一个基于浮动车数据的动态实时路段速度数据库。通过实时动态地获得数据库中路段数据,提出基于数据库操作的动态路径寻优算法。为提高算法效率,提出动态变化限制搜索区域大小的辅助算法,并通过实例应用实现算法。     

有限经济批量排产和运送问题的禁忌搜索算法

探讨使用禁忌搜索算法解决一个简单的供应链经济批量排产和运送问题。其中供应商通过一个灵活的生产流水线生产多个组件并进行装配。假定所有参数,如组件的需求率等具有确定性,找到本研究的目标就是求解最优的生产批量和排序,使供应链的平均投入和运输费用最小。