利用局部评估的分布式图模式匹配算法

为了在分布式存储的大规模数据图上进行快速图模式匹配,提出利用局部评估的分布式图模式匹配算法。各计算节点并行地执行本地匹配;协调器节点收集局部匹配结果、计算边界点的匹配状态并发送给相应的计算节点;计算节点根据边界点的匹配状态确定与边界点相连的节点的匹配情况;协调器节点组合得出最大匹配集。实验结果表明:与已有的分布式图模式匹配算法相比,dis GPM-PE算法都能够在不显著增加通信量的前提下避免数据片段间的依赖关系对执行时间的影响,从而减少图模式匹配的时间。     

Dynamic pricing and matching in ride-hailing platforms

Ride-hailing platforms such as Uber, Lyft, and DiDi have achieved explosive growth and reshaped urban transportation. The theory and technologies behind these platforms have become one of the most active research topics in the fields of economics, operations research, computer science, and transportation engineering. In particular, advanced matching and dynamic pricing (DP) algorithms—the two key levers in ride-hailing—have received tremendous attention from the research community and are continuously being designed and implemented at industrial scales by ride-hailing platforms. We provide a review of matching and DP techniques in ride-hailing, and show that they are critical for providing an experience with low waiting time for both riders and drivers. Then we link the two levers together by studying a pool-matching mechanism called dynamic waiting (DW) that varies rider waiting and walking before dispatch, which is inspired by a recent carpooling product Express Pool from Uber. We show using data from Uber that by jointly optimizing DP and DW, price variability can be mitigated, while increasing capacity utilization, trip throughput, and welfare. We also highlight several key practical challenges and directions of future research from a practitioner's perspective.     

接收机前端放大链与数字模块接口匹配分析

探讨了雷达数字化接收系统前端放大链与数字A/D模块级联后,接收系统的噪声系数、灵敏度和瞬时动态范围等参数的变化;研究了在工程上接收系统为获得最佳性能,前端放大链与数字A/D模块性能指标的折衷问题,推导了相应的设计公式并给出了实验验证.最后总结了在接收系统前端和A/D性能允许范围内,获得设计师希望得到的接收系统灵敏度和动态范围的方法及设计参考曲线.     

基于相似原理的点特征松弛匹配算法

利用感兴趣点检测算子提取点特征,构建三角形并利用其相似度来定义点特征的匹配度,提出了一种新的具有比例与旋转不变特性的点特征松弛匹配算法.实验表明,所提出的匹配算法有很快的运算速度和很高的匹配正确率.     

海战场态势评估问题的研究

对海战场综合态势进行态势评估和威胁分析是信息融合系统的最高层级,态势评估结果将对指挥员的指挥决策起到非常重要的作用。根据海军作战理论分析了海战场态势的表示方法,并基于模板方法设计了一种战场当前态势与模板数据库中态势进行匹配的算法。该算法特别适用于高层推理如态势或威胁评估。     

新型紫外非线性光学晶体K2Al2B2O7倍频特性研究

模拟计算了新型紫外光学晶体K2A l2B2O7的Ⅰ类、Ⅱ类倍频的相位匹配角、有效非线性系数,得到了其倍频的最短极限基频波波长和最大有效非线性系数,得到了其Ⅰ类、Ⅱ类倍频的走离角、允许角和允许波长的理论曲线。从理论上证明了K2A l2B2O7晶体是优质的新型紫外非线性光学晶体。     

Doubly Stochastic Sequential Assignment Problem

This article introduces the Doubly Stochastic Sequential Assignment Problem (DSSAP), an extension of the Sequential Stochastic Assignment Problem (SSAP), where sequentially arriving tasks are assigned to workers with random success rates. A given number of tasks arrive sequentially, each with a random value coming from a known distribution. On a task arrival, it must be assigned to one of the available workers, each with a random success rate coming from a known distribution. Optimal assignment policies are proposed for DSSAP under various assumptions on the random success rates. The optimal assignment algorithm for the general case of DSSAP, where workers have distinct success rate distribution, has an exponential running time. An approximation algorithm that achieves a fraction of the maximum total expected reward in a polynomial time is proposed. The results are illustrated by several numerical experiments. © 2016 Wiley Periodicals, Inc. Naval Research Logistics 63: 124–137, 2016     

一种实用的提高景象匹配可靠性的方法

景象匹配导航具有高准确性和高可靠性,因此被应用于诸多领域。从景象匹配适配区的选择出发,提出了一种实用的提高景象匹配可靠性的方法,在匹配前对参考图提取出高概率匹配区,然后再用NPROD算法进行匹配,实验证明该方法能够有效地提高景象匹配的可靠性。     

信号相位匹配法检测正弦信号的高阶统计量方法

为了能对提高高斯色噪声中正弦信号的检测能力,提出了二阶自相关和四阶累积量预处理的信号相位匹配检测法.仿真结果表明,高斯色噪声中四阶累积量预处理的信号相位匹配检测法的检测性能接近于高斯白噪声下匹配滤波器,优于二阶自相关的信号相位匹配检测法的检测性能,更优于的信号相位匹配的最小二乘检测器.     

冬季火场灭火装具保温防冻方法探讨

冬季火场灭火装具保温防冻问题一直困扰着消防部队的作战，利用适当的防冻措施可以极大地降低严寒对灭火装具的影响，提高部队的战斗力。就室外消火栓及消防车辆的保温问题，分析了几种常用保温方法，探讨了火场灭火装具的防冻对策。