大幅场景高分辨率SAR图像机场自动检测

针对现有大场景高分辨率SAR图像机场检测方法中所采用的图像分割方法效果不佳、适应性不强,直线特征提取方法耗时长且易产生断裂的问题,提出一种在大幅场景SAR图像中自动检测机场的方法。首先,提出基于PPB滤波的模糊C均值算法进行图像分割,利用区域特征筛选出感兴趣区域(ROI);然后,采用启发式搜索快速有效地提取线基元,并提出新的共线性测度方法减少线基元连接中的误连接和欠连接;最后,利用平行线特征和灰度特征实现机场的检测。实验结果验证了该方法的有效性。     

科普资源发布GIS的关键技术与查询实现

为整合各类科普资源、推动科普教育的信息化,方便市民查询分析各种科普资源,建立基于GIS的科普资源信息发布系统已显得十分迫切.GIS强大的空间查询与分析功能为科普资源发布系统的实现提供了可能.叙述科普资源发布系统的开发模式,论述系统设计与实现过程中应用的关键技术,给出栅格影像自动选择的优点与方法,矢量栅格匹配的原理与优势...     

电力系统震后网络连通性研究

文中针对电力系统网络的震后连通性开展研究,在电力系统网络基本模型基础上,增加网络单元的两值工作状态假设,建立了电力系统网络连通性分析模型,提出了电力系统网络连通性模型的邻接表存储结构,给出了深度优先搜索的基本原理,形成了基于邻接表的深度优先搜索算法.用该方法分析了某区域电网在汶川8.0级地震后的网络连通性,并对计算结果...     

大型港口集装箱船舶智能配载的集成算法研究

为解决集装箱码头智能化配载多业务规则集成优化问题,提出3层规划框架,重点研究第2层规划方法。该方法对资源分配规则,建立数学模型;对质量匹配规则和胎吊冲突规则,建立逻辑学模型;这些模型均以剪枝条件的形式融入到分支限界搜索中,而剪枝条件的正确性和有效性均有严格的证明保证。对于其它的业务规则,在生成和压缩解空间的过程中就已经充分考虑。同时并不忽略卸货港、尺寸、箱型等重要属性及其对配船位置的限制,实验结果验证算法的有效性。     

禁忌搜索算法在图像匹配中的应用研究

搜索策略是图像匹配研究的主要问题之一,对匹配算法的执行速度和最终的匹配精度都有很大的影响。该文将禁忌搜索算法的思想用于图像匹配的搜索过程,并进行了改进,构造了永久禁忌和暂时禁忌两种禁忌表,每次搜索都将候选解中的点分别放入不同的禁忌表中,再利用基于灰度的匹配方法,以归一化积相关为相似性度量准则,克服了传统的归一化积相关图像匹配算法耗时过长的缺点,可以在不失匹配精度的条件下,大大减少匹配所用的时间,实现了准确而快速的图像匹配。     

A Hybrid Multi‐Objective Evolutionary Algorithm for Optimal Groundwater Management under Variable Density Conditions

In this paper, a new hybrid multi-objective evolutionary algorithm (MOEA), the niched Pareto tabu search combined with a genetic algorithm (NPTSGA), is proposed for the management of groundwater resources under variable density conditions. Relatively few MOEAs can possess global search ability contenting with intensified search in a local area. Moreover, the overall searching ability of tabu search (TS) based MOEAs is very sensitive to the neighborhood step size. The NPTSGA is developed on the thought of integrating the genetic algorithm (GA) with a TS based MOEA, the niched Pareto tabu search (NPTS), which helps to alleviate both of the above difficulties. Here, the global search ability of the NPTS is improved by the diversification of candidate solutions arising from the evolving genetic algorithm population. Furthermore, the proposed methodology coupled with a density-dependent groundwater flow and solute transport simulator, SEAWAT, is developed and its performance is evaluated through a synthetic seawater intrusion management problem. Optimization results indicate that the NPTSGA offers a tradeoff between the two conflicting objectives. A key conclusion of this study is that the NPTSGA keeps the balance between the intensification of nondomination and the diversification of near Pareto-optimal solutions along the tradeoff curves and is a stable and robust method for implementing the multi-objective design of variable-density groundwater resources.     

地震灾区区域搜救优先级判定方法研究及应用

针对震后快速反应与应急救援辅助决策的需要,综合考虑灾区人口数量、人口密度、地形、交通、天气、烈度等因素,建立了地震灾区区域搜救目标优先级的评判模型,并以汶川地震为例进行了搜救目标优先级的划分,结果表明该方法可以满足大灾区的区域搜救优先级评定需求。     

Simulating urban growth in a metropolitan area based on weighted urban flows by using web search engine

As a consequence of rapid and immoderate urbanization, simulating urban growth in metropolitan areas effectively becomes a crucial and yet difficult task. Cellular automata (CA) model is an attractive tool for understanding complex geographical phenomena. Although intercity urban flows, the key factors in metropolitan development, have already been taken into consideration in CA models, there is still room for improvement because the influences of urban flows may not necessarily follow the distance decay relationship and may change over time. A feasible solution is to define the weights of intercity urban flows. Therefore, this study presents a novel method based on weighted urban flows (CA_WeightedFlow) with the support of web search engine. The relatedness measured by the co-occurrences of the cities’ names (toponyms) on massive web pages can be deemed as the weights of intercity urban flows. After applying the weights, the gravitational field model is integrated with Logistic-CA to fulfill the modeling task. This method is employed to the urban growth simulation in the Pearl River Delta, one of the most urbanized metropolitan areas in China, from 2005 to 2008. The results indicate that our method outperforms traditional methods with respect to two measures of calibration goodness-of-fit. For example, CA_WeightedFlow can yield the best value of ‘figure of merit’. Moreover, the proposed method can be further used to explore various development possibilities by simply changing the weights.     

国内太阳数据VO化初步方案

随着太阳物理研究的深入、观测仪器的发展、观测数据的积累，促使人们去思考这样的问题：利用全世界不同时间、地点、波段的太阳相关数据、历史数据去对很多悬而未解的科学问题寻求答案，同时使研究者容易的去检索这些数据，进行分析，这就是虚拟太阳天文台要解决的问题，也是为什么虚拟太阳天文台项目得到了全世界有关天文台、研究所和大学的积极响应和运作。本文介绍了国内应如何面对虚拟天文台的发展及国内太阳数据VO化初步方案。