一种基于多目标优化的QoS路由交互式算法

为了满足通信网络中一些特定业务对于多个网络指标性能的同时要求 ,研究了一类基于多目标决策的QoS路由算法。通过选取带宽作为约束条件 ,把时延和丢失率作为优化目标 ,建立了QoS路由选择的多目标非线性整数规划模型 ,并给出了一种求解模型的交互式算法。该算法通过逐步调整目标函数的上界 ,压缩目标函数的搜索空间来满足决策者的要求和网络条件。实例计算结果表明了算法的可行性     

Dynamic routing of prioritized warranty repairs

Recent years have seen a strong trend toward outsourcing warranty repair services to outside vendors. In this article we consider the problem of dynamically routing warranty repairs to service vendors when warranties have priority levels. Each time an item under warranty fails, it is sent to one of the vendors for repair. Items covered by higher priority warranty receive higher priority in repair service. The manufacturer pays a fixed fee per repair and incurs a linear holding cost while an item is undergoing or waiting for repair. The objective is to minimize the manufacturer's long‐run average cost. Because of the complexity of the problem, it is very unlikely that there exist tractable ways to find the optimal routing strategies. Therefore, we propose five heuristic routing procedures that are applicable to real‐life problems. We evaluate the heuristics using simulation. The simulation results show that the index‐based “generalized join the shortest queue” policy, which applies a single policy improvement step to an initial state‐independent policy, performs the best among all five heuristics. © 2007 Wiley Periodicals, Inc. Naval Research Logistics, 2008     

电子整机三维线缆EMC可视化预测研究

基于电磁场时域有限差分法(FDTD),进行电子整机三维线缆EM C问题的可视化预测研究,应用本研究结果,通过观测可视图形,可根据图形颜色与数值的对应关系判别线缆布线是否符合电磁兼容的要求。该成果应用到电子整机三维自动布线中,将完善布线系统,并提高布线的速度和质量。     

基于能量分级和位置预测的高效路由算法

针对车载传感器网络节点移动速度快、网络拓扑结构不稳定、终端传感器节点能量不确定性等特点,提出了一种能量分级和位置预测的高效路由算法ERLP(Energy Rank and Location Prediction based routing)。该算法根据具有不同能量等级的节点将消息传递距离的不同选择那些能量高的节点作为中转节点,并结合节点的分布区域和当前速度,尽量将多个消息副本传递给覆盖不同方向的节点,避免消息传递的局部性。仿真结果表明,与当前典型延迟容忍网络的路由算法相比,ERLP算法在传输成功率、平均延迟时间上具有较大提升。     

基于遗传算法的MIL-STD-188-220c标准最佳转发树的构造

针对MIL-STD-188-220C标准的路由协议多目的地址最佳转发树问题,提出一种基于遗传算法的优化算法,仿真结果表明,该算法具有收敛快,寻路成功率高的优点。     

Flexibility and complexity in periodic distribution problems

In this paper, we explore trade‐offs between operational flexibility and operational complexity in periodic distribution problems. We consider the gains from operational flexibility in terms of vehicle routing costs and customer service benefits, as well as the costs of operational complexity in terms of modeling, solution methods, and implementation challenges for drivers and customers. The period vehicle routing problem (PVRP) is a variation of the classic vehicle routing problem in which delivery routes are constructed for a period of time; the PVRP with service choice (PVRP‐SC) extends the PVRP to allow service (visit) frequency to become a decision of the model. For the periodic distribution problems represented by PVRP and PVRP‐SC, we introduce operational flexibility levers and a set of quantitative measures to evaluate the trade‐offs between flexibility and complexity. We develop a Tabu Search heuristic to incorporate a range of operational flexibility options. We analyze the potential value and the increased operational complexity of the flexibility levers. © 2006 Wiley Periodicals, Inc. Naval Research Logistics, 2007     

流媒体的RTP传输与QoS管理策略研究

应用RTP协议进行传输和实现QoS管理是当前数据传输方面的热点问题,通过分析RTP协议的结构和原理,提出了一种RTP的传输模型,实现了数据流的RTP传输,同时就RTCP协议(RTP协议的传输控制部分)对QoS的管理策略进行了理论探讨.     

编码感知的机会路由算法研究

提出一种编码感知的机会路由算法——CAR.它利用机会传输增加编码机会,并通过引入一系列参数衡量"机会"好坏,创造性地解决了交叉数据流下机会路由转发节点的选取问题,解决了流间网络编码和机会路由算法结合时数据包上下跳节点"已知"与"未知"的矛盾.CAR算法能够最大化每次编码传输中原始数据包的个数,仿真表明,它能够显著提高可靠传输协议以及整个网络的传输性能.通过机会传输实现多用户分集,可显著增加流间网络编码机会,引入的转发延时也可增加流间网络编码机会.     

一种基于Dijkstra算法的航空平台组网技术

针对航空平台在超低空和超视距飞行过程中,传统单一的TDMA网络难以满足无盲区通信需求,提出一种基于Dijkstra算法的AdHoc组网技术。通过建立实时邻居信息表、网络拓扑表和动态路由,在工程应用中实现了具有中继功能的地空-空空高速实时无线传输网络,满足了部队通信网络大范围覆盖和实时性需求。     

片上网络中一种单周期2GHz无缓冲路由器

近年来,无缓冲路由器由于不需要缓冲器而成为片上网络低开销的解决方案。为了提高无缓冲路由器的性能,提出一种单周期高性能无缓冲片上网络路由器。该路由器使用一个简单的置换网络替换串行化的交换分配器与交叉开关以实现高性能。虚通道路由器与基准无缓冲路由器相比,该路由器在TSMC65nm工艺下可以以较小的面积开销达到2GHz的时钟频率。在合成通信负载与真实应用负载下的模拟结果表明,该路由器的包平均延迟远小于虚通道路由器和其他无缓冲路由器。