An effective routing algorithm in incomplete hypercubes

An incomplete hypercube appears interesting and practical because of its relaxed restriction on the system size and possession of salient properties of complete hypercubes. The performance of incomplete hypercubes can be improved considerably by reducing communication time, which can be achieved by forwarding messages through two parallel paths between a pair of nodes. This paper presents a simple and effective two-parallel-paths routing algorithm for incomplete hypercubes which takes advantage of the flexibility provided by incomplete hypercubes, and yet prevents traffic congestion and deadlock. Simulation results indicate that the mean latency for sending large sized messages is reduced and the degree of reduction becomes larger when the system load grows. This significant reduction in latency could translate to a respectable performance improvement. This algorithm can also tolerate one fault in the system by sending duplicate copies of messages through two parallel paths with little increase in the mean latency under light-traffic load.     

Shortest paths of bounded curvature in the plane

Given two oriented points in the plane, we determine and compute the shortest paths of bounded curvature joining them. This problem has been solved recently by Dubins in the no-cusp case, and by Reeds and Shepp otherwise. We propose a new solution based on the minimum principle of Pontryagin. Our approach simplifies the proofs and makes clear the global or local nature of the results.     

Designing networks with compact routing tables

Classes of network topologies are identified in which shortest-path information can be succinctly stored at the nodes, if they are assigned suitable names. The naming allows each edge at a node to be labeled with zero or more intervals of integers, representing all nodes reachable by a shortest path via that edge. Starting with the class of outerplanar networks, a natural hierarchy of networks is established, based on the number of intervals required. The outerplanar networks are shown to be precisely the networks requiring just one interval per edge. An optimal algorithm is given for determining the labels for edges in outerplanar networks.The research of this author was supported in part by the National Science Foundation under Grant DCR-8320124, and by the Office of Naval Research on contract N 00014-86-K-0689.The research of this author was supported in part by the National Science Foundation under Grant DCR-8320124.     

Multi‐constrained Shortest Disjoint Paths for Reliable QoS Routing

Finding link‐disjoint or node‐disjoint paths under multiple constraints is an effective way to improve network QoS ability, reliability, and so on. However, existing algorithms for such scheme cannot ensure a feasible solution for arbitrary networks. We propose design principles of an algorithm to fill this gap, which we arrive at by analyzing the properties of optimal solutions for the multi‐constrained link‐disjoint path pair problem. Based on this, we propose the link‐disjoint optimal multi‐constrained paths algorithm (LIDOMPA), to find the shortest link‐disjoint path pair for any network. Three concepts, namely, the candidate optimal solution, the contractive constraint vector, and structure‐aware non‐dominance, are introduced to reduce its search space without loss of exactness. Extensive simulations show that LIDOMPA outperforms existing schemes and achieves acceptable complexity. Moreover, LIDOMPA is extended to the node‐disjoint optimal multi‐constrained paths algorithm (NODOMPA) for the multi‐constrained node‐disjoint path pair problem.     

不同应力路径下煤样变形破坏过程声发射特征的试验研究

 利用RMT–150B岩石力学试验机对义马耿村具有冲击倾向性煤样进行常规单轴、三轴和三轴卸围压试验,研究在不同应力路径下煤样变形破坏过程中的声发射特征。试验结果表明,煤样在不同应力路径下加载变形破坏过程中产生的声发射特征有所差异。常规单轴压缩过程中各个阶段均有不同程度的声发射事件,与三轴筒内单轴压缩相比,声发射累计计数和能量明显偏大,破坏瞬时的声发射计数和能量大致相当;常规三轴压缩试验时,在围压作用下煤样屈服前声发射事件较少,进入屈服阶段声发射事件逐渐趋于活跃,计数和能量大幅度增大,标志煤样破坏前兆,破坏瞬时声发射计数和能量达到最大值;三轴卸围压试验时,在卸围压前煤样处于弹性阶段声发射事件较少,随围压逐渐降低,由正应力提供的摩擦力不断减小,煤样内部材料强度相对较低逐步屈服破坏形成微裂纹。屈服前期产生少量声发射事件,屈服后期声发射事件逐渐趋于活跃,计数和能量大幅度增大,标志煤样卸围压破坏前兆,破坏瞬间计数和能量同时达到最大值,与常规三轴压缩相比,声发射计数更大,能量则更高,表明三轴卸围压煤样破坏时更加强烈;常规单轴压缩煤样破坏产生的声发射累计计数和累计能量明显偏大,三轴筒内单轴、常规三轴压缩以及三轴卸围压试验时,声发射累计计数和能量大致相同,没有明显差异。     

黑启动辅助决策支持系统

针对电网黑启动的特点和要求,结合图形建模技术、数据库技术和电力系统分析计算技术开发了一套可视化的电网黑启动辅助决策支持系统。该系统将图形系统与数据库结合形成图-模一体化平台,具有界面友好、交互性强和功能完善等特点。该系统采用了基于规则的黑启动路径自动生成算法形成黑启动初始路径方案,既避免了人工提供黑启动初始路径的繁琐,又能避免合理路径的遗漏;系统中所包括的路径分析功能及数据管理,既相互独立,又能相互配合,而形成了一个完整的系统。该系统所提供的分析结果的导出功能,可方便地生成黑启动初步分析报告,从而大大减轻撰写分析报告的压力。实际应用证明了该系统的有效性和工程实用性。     

海上搜救雷达应答器天线架设高度的研究

研究了多径和海面大气折射这两种环境因素对雷达搜索应答器最远距离的影响,使用PE方程计算了不同蒸发波导高度条件下导航雷达和应答器发射信号的传播衰减,通过对计算结果分析和解释,结合东海试验的实测数据,得出应答器天线高度的最佳选择。     

含金高硫铜锌多金属硫化矿浮选分离试验研究

我国某难选铜锌多金属硫化矿,铜锌硫矿物共生关系密切,且次生硫化铜矿物的含量较高,致使铜锌硫矿物分离难度较大。依据矿石特性,试验研究采用一段细磨—铜锌硫等可浮—铜锌硫分离—锌浮选的工艺流程,使用石灰、TW、硫酸锌和亚硫酸钠组合药剂作锌矿物的抑制剂,使用选择性较好的Z-200作为铜矿物的捕收剂,实现了铜锌矿物的有效分离,试验室闭路试验获得的铜精矿品位23.23%、铜回收率91.45%,锌精矿品位49.53%、锌回收率85.36%,硫精矿品位44.25%、回收率59.16%,分离指标较为理想。     

中国传统饮食文化融入食育路径研究

为国民身体素质、探索具有中国特色的现代食育之路，必须深入分析与探索中国饮食文化中的食育理念。文章以传统饮食文化为出发点和落脚点，概括出医食同源、饮食有节、饮食有礼等先进的食育观点。分析传统饮食与现代食育的关系，认为食育是弘扬传统饮食文化的重要途径，传统饮食文化是发展现代食育的基础。但探索现代食育仍面临着西方快餐文化冲击和国民食育进程缓慢等困境，必须采取强化国民食育意识、加强食育法制建设、健全食育教育体系、推进食育试点工作等措施促进中国传统饮食文化融入食育体系建设，真正探索具有中国特色的食育之路。