1,3-丙二醇生产方法及用途

本文介绍并比较了 1,3-丙二醇的生产方法。在环氧乙烷法、丙烯醛法和生物技术法三种有工业应用前景的生产方法中 ,环氧乙烷法比丙烯醛法更有竞争力 ,生物技术法在国外是很有吸引力的路线 ,但国内由于农产品的价格偏高降低了该路线的竞争力。本文也简要介绍了 1,3-丙二醇的用途     

城市直送式配送运输线路优化

运用运筹学中的Dijkstra算法建立模型,给出对城市直送式货物配送运输车辆路线进行优化的方法和步骤,得出最优运输线路。并结合某市道路状况,以配送运输路线的优化选择为例,作出具体优化计算。配送线路优化能有效提高企业的服务质量、降低成本。     

浅析CDMA山区及交通干线覆盖方案

文章结合不同的用户分布和山区丘陵地形的特点进行站址选择和设备选型的分析,通过系统仿真来比较高山站与平地站的覆盖范围,综合考虑覆盖目标、建设成本和投资收益对二者进行取舍。直放站和射频拉远(RRU)是山区交通干线优化时的主力军,着重分析直放站对施主基站低噪抬升的影响。     

500kV变压器直流偏磁下的铁心损耗分析研究

为了研究变压器直流偏磁下的铁心损耗,文章以某一核电站500 k V主变压器为例,在二维有限元瞬态场A–φ算法基础下构造了直流偏磁下的变压器二维仿真损耗模型。在仿真中,偏磁直流量从0 A增加至30 A,可得到变压器铁心的损耗分布。结果分析可表明:随着偏磁直流量的增加,励磁电流会产生畸变和较大的偶次谐波,并导致铁心局部损耗增大,其中:铁心主柱与上、下铁轭交接区域的损耗值受到直流偏磁的影响最大,铁心水平路径的损耗值相较于垂直路径受直流偏磁的影响较大。     

Cruise missile multiple routes planning based on hybrid particle swarm optimization

In order to solve cruise missile route planning problem for low-altitude penetration,a hybrid particle swarm optimization( HPSO) algorithm is proposed. Firstly,K-means clustering algorithm is applied to divide the particle swarm into multiple isolated sub-populations,then niche algorithm is adopted to make all particles independently search for optimal values in their own sub-populations. Finally simulated annealing( SA) algorithm is introduced to avoid the weakness of PSO algorithm,which can easily be trapped into the local optimum in the search process. The optimal value obtained by every sub-population search corresponds to an optimal route,multiple different optimal routes are provided for cruise missile. Simulation results show that the HPSO algorithm has a fast convergence rate,and the planned routes have flat ballisticpaths and short ranges which meet the lowaltitude penetration requirements.     

淮盐文化线路的判别与梳理

横跨古淮河尾闾南北、南至长江口、北到赣榆县的两淮海盐产区,是我国历史上最为悠久的海盐产区之一,在相当长一段时期内也是我国产量最高、规模最大的盐区,所以才有"天下盐利淮为大"的说法。从文化线路的视角,分别对文化线路应具备的时间指标、空间指标和文化功能指标这三个要素进行分析,阐述淮盐文化遗产满足文化线路遗产判别的基本要求,其具备较高的资源价值、遗产价值和旅游价值。     

2-Covered paths by a set of antennas with minimum power transmission range

In this paper we describe and solve the following geometric optimisation problem: given a set S of n points on the plane (antennas) and two points A and B, find the smallest radial range r∈^ℜ+ (power transmission range of the antennas) so that a path with endpoints A and B exists in which all points are within the range of at least two antennas. The solution to the problem has several applications (e.g., in the planning of safe routes). We present an O(nlogn) time solution, which is based on the second order Voronoi diagram. We also show how to obtain a path with such characteristics.     

External watchman routes

We consider the problem of finding a shortest watchman route from which the exterior of a polygon is visible (external watchman route). We present an O (n ⁴ log logn) algorithm to find shortest external watchman routes for simple polygons by transforming the external watchman route problem to a set of internal watchman route problems. Also, we present faster external watchman route algorithms for special cases. These include optimal O (n) algorithms for convex, monotone, star and spiral polygons and an O (n log logn) algorithm for rectilinear polygons.This work was supported in part by a grant from Texas Instruments, Inc. to S. Ntafos     

基于SGML数据的船舶航线可视化

提出了基于SGML数据的船舶航线可视化方法,其基本原理是从SGML数据解析、船舶航线经纬度实时读取与航线要素可视化等三个方面入手,设计和实现了SGML的船舶航线可视化。     

Minimal functional routes in directed graphs with dependent edges

Graphs are mathematical structures used to model a set of objects and the relations between them. One of the basic concepts of graph theory, the path, has wide real‐world applications. In classic graph models, edges ending at a node are assumed to be independent. However, many real graphs/networks can only be correctly described by considering a dependency among nodes or edges. Paths in such graphs may not be functional if the conditional dependency is ignored. In this study, we investigate the routing problem in directed graphs with dependent edges represented by general graph models as alternatives to hypergraphs. We define a minimal functional route (MFR) as a minimal set of nodes and edges that can independently perform information transfer between two given nodes, and formulate the determination of MFRs as a graph search problem. A depth‐first‐search (DFS) top‐down algorithm, an iterative integer linear programming (ILP) bottom‐up algorithm, and a subgraph‐growing bottom‐up algorithm are devised subsequently to solve this problem. Numerical experiments verify the effectiveness of the algorithms. The defined MFR problem and the proposed algorithms are expected to find many practical applications.