共查询到20条相似文献，搜索用时 71 毫秒
1.
Concerns over the potential negative health effects from exposure to air pollution have led to interest in assessing personal exposure and finding ways to reduce it. As journey-time exposure accounts for a disproportionately high amount of an individual's total exposure, this article assesses the potential to apply least-cost techniques within a GIS in order to identify paths of lower journey-time exposure. The methodology adopted uses pollution surfaces for PM10 and CO generated by the dispersion model ADMS, with an analysis mask derived from OS MasterMap to create a least-cost surface. Actual routes taken by a cohort of 11–13 year old children on their journeys to school are used to compare observed journey time exposure with the exposure along alternative routes generated using the least-cost path function. While the least-cost approach proved to be successful in defining low exposure routes the ability to scale up this approach is constrained by the amount of editing required to successfully create an analysis mask from OS MasterMap data. Such alternative routes have the potential to assist in promoting safer environmental choices, however, their likelihood of adoption is dependant on a number of social and environmental influences which affect an individual's route choice. 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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Identifying a route that avoids obstacles in continuous space is important for infrastructure alignment, robotic travel, and virtual object path planning, among others, because movement through space is not restricted to a predefined road or other network. Vector and raster GIS (geographic information system) solution approaches have been developed to find good/efficient routes. On the vector side, recent solution approaches exploit spatial knowledge and utilize GIS functionality, offering significant computational advantages in finding an optimal solution to this path routing problem. Raster‐based shortest path techniques are widely applied in route planning for wayfinding, corridor alignment, robotics and video gaming to derive an obstacle avoiding path, but represent an approximation approach for solving this problem. This research compares vector and raster approaches for identifying obstacle‐avoiding shortest paths/routes. Empirical assessment is carried out for a number of planning applications, highlighting representational issues, computational requirements and resulting path efficiency. 相似文献
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采用网络问卷的方式,对大型商场内人群的择路行为认知规律进行了研究,发现不论在楼梯类别的选择还是在上下楼路线的选择等择路行为上,不同性别、年龄、教育程度的人均体现出一致性。人们在上楼时的楼梯、路线选择上具有明显的倾向性,但在下楼时的选择相对较为平衡;不论上楼还是下楼,当楼层差在两层以下时,大部分人会选择自动扶梯;当楼层差大于等于三层时,大部分人会选择电梯。对室内空间处于不同楼层的两点之间的最优路径分析具有参考价值。 相似文献
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Personalized travel route recommendation using collaborative filtering based on GPS trajectories 总被引：1，自引：0，他引：1
Travelling is a critical component of daily life. With new technology, personalized travel route recommendations are possible and have become a new research area. A personalized travel route recommendation refers to plan an optimal travel route between two geographical locations, based on the road networks and users’ travel preferences. In this paper, we define users’ travel behaviours from their historical Global Positioning System (GPS) trajectories and propose two personalized travel route recommendation methods – collaborative travel route recommendation (CTRR) and an extended version of CTRR (CTRR+). Both methods consider users’ personal travel preferences based on their historical GPS trajectories. In this paper, we first estimate users’ travel behaviour frequencies by using collaborative filtering technique. A route with the maximum probability of a user’s travel behaviour is then generated based on the naïve Bayes model. The CTRR+ method improves the performances of CTRR by taking into account cold start users and integrating distance with the user travel behaviour probability. This paper also conducts some case studies based on a real GPS trajectory data set from Beijing, China. The experimental results show that the proposed CTRR and CTRR+ methods achieve better results for travel route recommendations compared with the shortest distance path method. 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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This paper introduces a GIS-based model that simulates the geographic expansion of transport networks by several decision-makers with varying objectives. The model progressively adds extensions to a growing network by choosing the most attractive investments from a limited choice set. Attractiveness is defined as a function of variables in which revenue and broader societal benefits may play a role and can be based on empirically underpinned parameters that may differ according to private or public interests. The choice set is selected from an exhaustive set of links and presumably contains those investment options that best meet private operator’s objectives by balancing the revenues of additional fare against construction costs. The investment options consist of geographically plausible routes with potential detours. These routes are generated using a fine-meshed regularly latticed network and shortest path finding methods. Additionally, two indicators of the geographic accuracy of the simulated networks are introduced. A historical case study is presented to demonstrate the model’s first results. These results show that the modelled networks reproduce relevant results of the historically built network with reasonable accuracy. 相似文献
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Raja Sengupta Griet Vankeerberghen Ruoxuan Wen Jing Rao Yanbing Chen 《Transactions in GIS》2023,27(4):1090-1103
GIS-enabled historiography allows us to shed light on missing or poorly understood aspects of historical events. Here, we use agent-based models (ABMs), least cost path analysis (LCPA), and space–time paths to recreate and evaluate possible modes and routes of travel undertaken by Shi Rao, a Western Han official. A diary was found in Shi Rao's tomb that includes information about his travels over 1 year (11 BCE), including start and end times of his journeys. But it leaves out details regarding modes of transport or exact routes. Using Tan Qixiang's historical atlas, we digitized river networks and utilized modern topographic data to digitally recreate the landscape as it was during Shi Rao's travels. This was then used to evaluate possible journeys via rivers (using ABMs) and roads (using LCPA), and compared to historical speed of boats, carts and horses, with findings indicating that horseback may have been the viable option. 相似文献
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Human beings’ intellection is the characteristic of a distinct hierarchy and can be taken to construct a heuristic in the shortest path algorithms. It is detailed in this paper how to utilize the hierarchical reasoning on the basis of greedy and directional strategy to establish a spatial heuristic, so as to improve running efficiency and suitability of shortest path algorithm for traffic network. The authors divide urban traffic network into three hierarchies and set forward a new node hierarchy division rule to avoid the unreliable solution of shortest path. It is argued that the shortest path, no matter distance shortest or time shortest, is usually not the favorite of drivers in practice. Some factors difficult to expect or quantify influence the drivers’ choice greatly. It makes the drivers prefer choosing a less shortest, but more reliable or flexible path to travel on. The presented optimum path algorithm, in addition to the improvement of the running efficiency of shortest path algorithms up to several times, reduces the emergence of those factors, conforms to the intellection characteristic of human beings, and is more easily accepted by drivers. Moreover, it does not require the completeness of networks in the lowest hierachy and the applicability and fault tolerance of the algorithm have improved. The experiment result shows the advantages of the presented algorithm. The authors argued that the algorithm has great potential application for navigation systems of large-scale traffic networks. 相似文献
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An optimum vehicular path algorithm for traffic network based on hierarchical spatial reasoning 总被引：5，自引：0，他引：5
Human beings' intellection is the characteristic of a distinct hierarchy and can be taken to construct a heuristic in the shortest path algorithms.It is detailed in this paper how to utilize the hierarchical reasoning on the basis of greedy and directional strategy to establish a spatial heuristic,so as to improve running efficiency and suitability of shortest path algorithm for traffic network.The authors divide urban traffic network into three hierarchies and set forward a new node hierarchy division rule to avoid the unreliable solution of shortest path.It is argued that the shortest path,no matter distance shortest or time shortest,is usually not the favorite of drivers in practice.Some factors difficult to expect or quantify influence the drivers' choice greatly.It makes the drivers prefer choosing a less shortest,but more reliable or flexible path to travel on.The presented optimum path algorithm,in addition to the improvement of the running efficiency of shortest path algorithms up to several times,reduces the emergence of those factors,conforms to the intellection characteristic of human beings,and is more easily accepted by drivers.Moreover,it does not require the completeness of networks in the lowest hierarchy and the applicability and fault tolerance of the algorithm have improved.The experiment result shows the advantages of the presented algorithm.The authors argued that the algorithm has great potential application for navigation systems of large-scale traffic networks. 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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基于瞬时水深模型的最短时间航线自动生成算法 总被引：2，自引：0，他引：2
优化的海图航线设计是舰船安全、经济航行的先导和基础。本文提出了一种基于瞬时水深模型的最短时间航线自动生成算法。基于海图静态水深和海域潮位模型,构建瞬时水深模型,动态提取碍航区,并进行航线可行性分析;利用动态规划思想,进行最短时间路径搜索;采用矩形包络分析、相近节点搜索和冗余点删除等策略,进行航线优化。实验表明：本文所提算法,能动态分析航线可行性,搜索最短时间航线; 与传统的最短时间航线算法相比,所提算法可提取航行时间更短的航线;所提取的最短时间航线,与舰船航行的起始时间和舰船航速相关。 相似文献
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针对生活中常见的二维电子服务地图,本文探讨了运用于已知的路径数据接口在2.5D电子地图上来实现3种路径规划的WebGIS设计方案。该项目将基于开源的Openlayers JavaScript类库包,实现公交路线、自驾路线、步行路线的查询、显示、路线详细展示以及模拟实现导航功能。就实际研发过程中遇到的问题探讨解决方案,实现了基于OpenLayers的2.5D电子地图路径规划。 相似文献
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最短路径算法:分类体系与研究进展 总被引：76，自引：3，他引：76
最短路径算法是计算机科学与地理信息科学等领域的研究热点。本文首先讨论了平面图的搜索策略，然后从问题类型、网络类型和实现方法3方面对最短路径算法进行了系统的分类，从理论上比较了近年来所提出的各具有较高效率的串行最短路径算法的时间复杂度，并对国内外一些相关研究进行了综合评述，结合城市交通网络的实验结果，作者对几种应用最为广泛的串行最短路径算法的运行效率进行了分析和评价，最后对最短路径算法在实时化和并行化方面的发展进行了讨论。 相似文献
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针对现有的LiDAR航线设计软件绝大多数针对大中型无人机,主要依靠飞行人员根据实际经验敷设航线,少数采用传统摄影测量改变基线长度的方式实现复杂地势下LiDAR航线自动敷设,但高地势地区航线较密,飞行成本高,有局限性,目前能实现轻小型无人机载LiDAR航线自主敷设的软件很少等问题,参照轻小型机载LiDAR的特点,该文提出一种复杂地势下基于DEM改变航高的航线设计方法。以延庆某山区进行试验。结果表明:该方法适当放宽分区高差限制,综合考虑地形信息、飞机性能等要素,使得单条航带点云密度得到保证,提高航线规划效率,节约飞行时间。将考虑DEM与未考虑DEM两种方式对比,确保重叠度,满足工程点云密度,便于后期数据处理。 相似文献
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以开放性问题的方式调查大学新生对地理空间的认知,通过让被试者绘制其从家乡入学的路线,并在经过简短的地理和地图基础知识理解后再进行同一问题的路线描述,试图发掘基础地理知识对路线理解的前后变化、揭示空间认知能力如何体现在绘制路线上。研究结果表明,被试者会选择文字、示意简图、方位图方式绘制心像地图,具有较强的空间记忆能力;经过地理和地图基础知识介绍后,被试者的描述方式发生改变,增强了空间感知能力和知识叠加能力;选择交通方式的不同对路线描述、途经要素的选择及途经地点数量会产生重要影响;地理和地图基础知识的介绍对途经地点的数量和行政等级几乎没有影响;山川河流及知名建筑等地理要素对人认知记忆产生重要影响,是路线描绘过程中的重要标志;远距离路线描绘会出现等级空间思维而"详-略"结合的地图刻画。实验揭示了路线描述的个体差异和上述的共同点。 相似文献
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一种基于时空拥挤度的应急疏散路径优化方法 总被引：3，自引：1，他引：2
提出时空拥挤度的概念来描述时间与空间维上的移动对象的拥挤程度,并以此提出一种基于拥挤度的应急疏散路径优化方法,该方法能够为大型公共场所的人员疏散提供从建筑物内部经由路网离开危险区域的一个完整疏散路径方案。分析在疏散路径分配的过程中以最短路径为基础的疏散路径分配方案的拥堵情形,然后以缓解拥堵、减少疏散总时间为目标,设计疏散路径分配方案的优化方法。试验结果表明优化后的方案能够减轻整个疏散方案的拥堵程度,同时能够为每个疏散个体提供一条相对合理的疏散路径。 相似文献