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针对障碍存在情况下距离变换研究较少的问题,提出了一种基于元胞自动机的绕障欧氏距离变换方法。以南海为例,基于海陆分布数据和目标点数据,以最短绕障路径长度为元胞状态,设计了包含距离算子的元胞状态转换规则。通过元胞自动机模拟距离扩散计算过程,得到绕障距离变换结果,并分析了绕障效果和精度。结果表明:本文方法动态直观地展示了绕障距离变换过程,能够自动计算绕过障碍的最短距离;具有更新机制,能够根据邻域的变化修正状态值;为绕障距离变换问题提供了一种近似的解决途径,错误率低于3.96%,可应用于航线设计、海上救助等领域。 相似文献
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沈正军 《测绘与空间地理信息》2007,30(2):36-39
最优路径分析是GIS中基本空间分析之一,迄今为止,国内外出现不少关于最短路径/最优路径算法的研究,但其数据模型主要以矢量数据模型或网络模型为主,而建立在栅格数据模型上的最优路径算法的相关研究较少。基于栅格的最优路径算法是一些专业应用模型的基础,如道路通达度模型、城市引力模型、洪水演进过程模型等,其算法设计非常重要。本文在前人的研究基础上,提出一种用于计算栅格最优路径的算法,对其计算过程进行了详细的分析与描述,并根据实验结果总结了其优点和缺点。 相似文献
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Case-based reasoning is an AI technique in which the previous solutions are stored for future use. People are used to guiding themselves according to those routes that are stored in their memories and have been used by them before. It is just based on people’s preference to familiar routes, which are gained through the study of the cognitive activities. We propose to apply the intelligent method based on the case reasoning to path planning. It is impossible for a case base to store all the solutions to all the shortest paths; therefore, part of them should be stored. However, which routes should be stored and which should not be? How do we adapt the cases that have already been stored and how do we acquire the shortest route based on them? All these issues need to be explained by integrating knowledge of the network on account of case-based reasoning techniques. This paper suggests the case-based reasoning in another point. This means finding some irreplaceable links on the basis of the complete analysis of the problems space, which are called the must_be_passed link between the source and destination. Merely compute the shortest path case from those best exit/entry nodes of the grids to the irreplaceable links, and then add them into the case base storing for future use. This method is based on case-based reasoning technique and completely considers the properties of the problem space. In addition to the use of knowledge of the natural grid in the route network, this method is more efficient than existing algorithms on computing efficiency. 相似文献
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大椭圆航线设计的空间矢量方法 总被引：2，自引：2，他引：0
针对传统大圆航线设计采用的球体模型和现代导航设备采用的椭球体模型不统一引起航行误差的问题,研究了基于空间矢量的大椭圆航线设计方法。通过采用空间矢量代数方法直接求解大椭圆顶点,并提出依据长轴矢量和短轴矢量的大椭圆描述方法,应用两个基本矢量推导大椭圆航线方位和航程计算公式,进而研究了大椭圆航线设计算法,重点提出了基于Newton-Raphson(N-R)的等距离航线设计算法。对比算例表明,大圆航线与大椭圆航线设计结果差异明显,大椭圆航线设计算法与航行阶段采用的地球模型一致,可消除大圆航线设计引起的误差,提高航海计算精度。 相似文献
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将行人的生理因素与GIS路径分析有机结合起来,根据生理学研究进展,建立了步行体能消耗计算模型,并提出了基于坡度转换的等效水平距离计算原则,从而将三维空间距离转换为等体能消耗平面距离,实现了顾及地形起伏的最优路径算法。实验结果表明,该算法具有兼顾坡度与距离关系的优势,提高了路径分析方法的有效性。 相似文献
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The characteristics of asymmetric pedestrian behavior: A preliminary study using passive smartphone location data 
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下载免费PDF全文 Nick Malleson Anthony Vanky Behrooz Hashemian Paolo Santi Santosh K. Verma Theodore K. Courtney Carlo Ratti 《Transactions in GIS》2018,22(2):616-634
Understanding the movements of people is essential for the design and management of urban areas. This article presents a novel approach to understanding the asymmetry in route choice (i.e., the degree to which people choose different walking routes for their outbound and return journeys). The study utilizes a large volume of traces of individual routes, captured using a smartphone application. The routes are aggregated to a regular grid, and matrix statistics are developed to estimate the aggregate degree of route asymmetry for different types of route (shortest, longest, weekday, weekend, etc.). The results suggest that people change their route approximately 15% of the time. Although this varied little when observing trips made at the weekend or on a weekday, people taking journeys that deviated substantially from the shortest possible path were 6 percentage points less likely to change their routes than those taking journeys that were closest to the shortest path (14 and 20% asymmetry, respectively). The absolute length also impacted on the asymmetry of journeys, but not as substantially. This result is important because, for the first time, it reports a correlation between deviation from shortest route and aggregate pedestrian choice. 相似文献
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Along with rapid global urbanization, cities are challenged by environmental risks and resource scarcity. Sustainable urban planning is central to address the dilemma of economic growth and ecosystem protection, where the use of land is critical. Sustainable land use patterns are spatially explicit in nature, and can be structured and addressed using spatial optimization integrating GIS and mathematical models. This research discusses prominent sustainability concerns in land use planning and suggests a generalized multi‐objective spatial optimization model to facilitate conventional planning. The model is structured to meet land use demand while satisfying the requirements of the physical environment, society and economy. Unlike existing work relying on raster data, due to its simple data structure and ease of spatial relationship evaluation, this research develops an approach for identifying land use solutions based on vector data that better reflects the actual shape and spatial layout of land parcels as well as the ways land use information is managed in practice. An evolutionary algorithm is developed to find the set of efficient (Pareto) solutions given the complexity of vector‐based representations of space. The proposed approach is applied in an empirical study of Dafeng, China in order to support local urban growth and development. The results demonstrate that spatial optimization can be a powerful tool for deriving effective and efficient land use planning strategies. A comparison to results using a raster data approach supports the superiority of land use optimization using vector data as part of planning practice. 相似文献
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针对障碍环境中路径规划存在的运算效率低、最短路径遗失问题,根据凸包边界在构建空间网络模型过程中具有快速高效的特点,结合路径与障碍物的相对位置关系,提出了一种基于双侧凸包扩张模型的路径快速规划算法.该算法在对凸包边界算法进行改进的基础上,提取左右侧关联障碍物的凸包边界作为网络模型,利用最短路径算法搜寻目标路径,并在Arc... 相似文献
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设计了基于障碍距离的优化算法,解决突发事件应急联动中复杂地理环境下最短路径的寻优求解问题。在详细分析地理空间高程、坡度、障碍物等空间信息的基础上,通过计算搜索空间、搜索方向和网络弧段权值构建网络拓扑关系网,并利用遗传算法对最优路径进行寻优求解。 相似文献
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网络最短路径的地图代数栅格算法 总被引：4，自引：1，他引：3
在阐述网络分析和最短路径算法的现状的基础上,以地图代数为理论支撑,介绍了地图代数对于网络元素的表达,探讨另外一种途径的网络最短路径分析—基于栅格数据的最短路径分析,重点讨论了基于地图代数的网络数据模型、栅格路径距离计算方法,在此基础上论述了求取最短路径的栅格方法的具体过程。最后,通过算例证明栅格途径的网络分析有其独特的优势。 相似文献
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Existing GIS‐based least‐cost routefinding approaches can in some cases be confounded by linear features in the landscape whose crossing costs are high relative to other traversing costs found throughout the landscape. Unfortunately, such high‐cost linear features are not uncommon; they frequently occur in the form of hydrologic features whose crossing costs are high relative to costs of traversing the surrounding dry land. This study (1) enumerates the situations where existing approaches can fail, (2) proposes a simple method for overcoming the limitations of the existing approaches, and (3) conducts an experiment to assess the impact of the weaknesses of existing approaches and the magnitude of the differences between the results produced by existing and revised approaches. Our results show that in mountainous terrain, linear hydrologic features with high crossing costs can have a profound impact on least‐cost routes, and the choice of solution method has equally profound impacts on the optimal route produced by the analysis. 相似文献
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While finding the optimal route for users with physical disabilities and personalizing routes for each user, on the one hand, and collaborative wayfinding, on the other hand, have been addressed in the pedestrian navigation systems literature, there has not been much research on combining the two activities. The problem associated with wayfinding approaches solely based on information about network segments and personal preferences is that the information about segments in the database may not, correctly and/or adequately address user preferences. The problem associated with wayfinding approaches solely based on the ratings given to routes by wheelchair users is the lack of rates (or scores) for all possible routes between all possible origin‐destination pairs in the network. This article discusses an approach to combine these two approaches for wayfinding to augment each other's shortcomings. To evaluate the personalized wayfinding approach, we utilize a route index, called a comparison index. The results show that with a P‐value of 9%, the routes obtained from our approach are more accessible than the routes obtained from another approach developed in another study. To evaluate the collaborative wayfinding approach, a Monte Carlo simulation was conducted which reflects the updates in routes as users' feedbacks become available. 相似文献
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自驾游以自主性、灵活性、选择性以及多样性等内在特点吸引着许多人,而它的线路设计质量直接影响自驾游者的心理满意度。通过收集、梳理河南省优秀旅游资源的空间分布、景区详情、交通道路等信息,依据旅游学中旅游行为空间模式、数学中图论和旅行商问题、地理信息系统(GIS)等科学理论,设计河南省自助游的最佳旅游线路。本研究以具有河南代表性的旅游景区为实际空间数据源,以ArcGIS系统为空间分布、交通等属性信息的可视化工具,以图论和旅行商问题为路线设计的数学基础,构建出自驾游线路设计的模式。本研究方法简单科学,为广大自驾游者规划旅游线路提供了有实际意义的参考。 相似文献
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本文介绍了最小生成树及其常见的算法,对比栅格算法分析了基于矢量的最小生成树算法的缺点,介绍了地图代数的距离变换和基于地图代数的距离变换图生成Voronoi图、Delaunay三角网,然后根据最小生成树MST是Delaunay三角剖分的一个子集,逐次删掉Delaunay三角网中每个三角形的最长边,从而得到最小生成树,该方法不仅适用于欧氏非障碍空间,同样也适用于障碍空间的情况,解决了以往最小生成树在障碍空间下(尤其是当障碍空间中的障碍是全形态的条件下)难以求解的问题,具有一定的理论意义。 相似文献
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讨论了一种地理信息系统空间分析算法——最短路径分析,然后利用最短路径结果,采用表上作业法将灾害救援物资进行优化,给出最优调运方案。 相似文献
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The problem of finding the least-cost path from a source point to a destination point can be dealt with by routing across a continuous surface or routing along a discrete network. The solutions within these two contexts are linked to the use of a raster- or a vector-based least-cost path algorithm. This study presents a technique which integrates raster- and vector-based least-cost path algorithms for determining the least-cost path across a continuous raster surface with discrete vector networks. The technique incorporates ancillary vector data sets that are required to examine the travel cost at each link, connections between nodes, and the representation of intersecting links in the discrete vector network into raster-based least-cost path analysis. The integrated technique presented here is applicable to all-terrain vehicle navigation where a continuous raster surface and discrete vector networks need to be considered simultaneously in order to find least-cost paths. This paper describes the concept behind, and details of, the integrated technique. Applications of the technique with synthetic and real-world data sets are also presented. They provide proof that the technique is effective in finding least-cost paths across a continuous raster surface with discrete vector networks. 相似文献