Assessing Raster GIS Approximation for Euclidean Shortest Path Routing

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.     

一种基于遗传算法的多模式多标准路径规划方法

单一路径评价标准难以满足日益多样化的出行路径规划需求。多标准路径规划成为公众出行服务的研究热点。然而,多标准路径规划本质上是具有NP特性的多标准决策问题,且涉及多种交通出行模式。多个不同标准的权重设置将直接影响路径规划结果。因此,如何科学合理地设置不同标准的权重成为多标准路径规划中的技术瓶颈。本文提出了一种适应多模式交通网络环境的多标准路径规划方法,借鉴遗传算法在求解多标准优化问题中的优势,将其扩展到多模式多标准路径规划中。该方法避免了不同出行标准权重设置中的主观性和不确定性,能够实现更为灵活的交通出行模式自动化组合,为出行者提供满足个性化需求的、多标准的出行路径规划服务。     

A New Framework for Solving the Spatial Network Problems Based on Line Graphs

In this article we define inverse line graphs of directed graphs as a new framework for solving some classical network analysis problems. The extraction method and theories of inverse line graphs are explained in this article. It is shown that by changing the analysis space from the original directed graph to the inverse line graph, complex problems can be changed into simpler problems. We show the usefulness of the proposed framework in two particular applications: shortest path computations and the more general route planning. Considering the implementation result, we expect that this framework could be used in many more network analysis problems.     

顾及相似用户特征的个人位置预测算法

个体位置预测在传染病精准防控、公共设施科学规划等应用中具有重要意义,既有位置预测算法主要侧重对个体纵向历史轨迹特征进行挖掘建模,从而实现位置预测,对横向相似性用户的规律特性考虑较少。因此,基于图卷积和长短期记忆模型（long short-term memory,LSTM）框架,提出顾及横向相似用户轨迹特征以及纵向历史规律性特征的个体位置预测算法。首先,构建用户轨迹相似性算法并筛选高相似度用户;然后,利用图卷积模型提取待预测用户相似高的用户轨迹特征;最后,利用LSTM框架提取历史轨迹特征,集成相似用户轨迹特征,从而实现个体位置预测。基于某市8万多个用户连续4个工作日的数据进行实验,结果表明,所提算法的准确率随预测时间步长增加而下降,而夜间预测准确率明显高于白天,但相比于既有模型均有10%以上提高;以15 min为预测时间步长时,模型准确率达80.45%。     

Routing through open spaces – A performance comparison of algorithms

Abstract

Finding the shortest path through open spaces is a well-known challenge for pedestrian routing engines. A common solution is routing on the open space boundary, which causes in most cases an unnecessarily long route. A possible alternative is to create a subgraph within the open space. This paper assesses this approach and investigates its implications for routing engines. A number of algorithms (Grid, Spider-Grid, Visibility, Delaunay, Voronoi, Skeleton) have been evaluated by four different criteria: (i) Number of additional created graph edges, (ii) additional graph creation time, (iii) route computation time, (iv) routing quality. We show that each algorithm has advantages and disadvantages depending on the use case. We identify the algorithms Visibility with a reduced number of edges in the subgraph and Spider-Grid with a large grid size to be a good compromise in many scenarios.     

一种智能的最短航线构建方法

航线的优化设计是舰船安全、经济航行的基础。本文提出一种智能的最短航线构建方法。通过追踪安全等深线,获取障碍区,然后测试线段与障碍区的空间关系来智能地搜索最短路径。实验表明,与传统方法相比,新方法在效率、准确性和可靠性上都具有明显的优势。     

Investigating Hologram-Based Route Planning

It is often assumed that three-dimensional topographic maps provide more effective route planning, navigation, orientation, and way-finding results than traditional two-dimensional representations. The research reported here investigates whether three-dimensional spatial mappings provide better support for route planning than two-dimensional representations. In a set of experiments performed as part of this research, human subjects were randomly shown either a two- or three-dimensional hologram of San Francisco and were asked to plan a bicycling route between an origin and a destination point. In a second task, participants used these holograms to identify the highest elevation point in the displayed area. The eye-movements of the participants, throughout the process of looking at the geospatial holograms and executing the tasks, were recorded. The eye-tracking metrics analysis indicates with a high statistical level of confidence that three-dimensional holographic maps enable more efficient route planning. In addition, the research group is developing a new algorithm to analyze the differences between participant-selected routes and a set of "good routes." The algorithm employs techniques used to represent the boundary of objects and methods for assessing the difference between objects in modern digital image recognition, image registration, and image alignment applications. The overall goal is to create a theoretical framework for investigating and quantifying route planning effectiveness.     

Mapping Apeldoorn

Abstract

Navigation around urban areas is often constraining for the mobility-impaired due to the fabric of the urban landscape, and there is a need to provide maps tailored to individual abilities. Barriers to effective navigation, such as slope, surface type and dropped kerbs, differ for able-bodied pedestrians and wheelchair users. This study identifies and quantifies such differences, and develops a Geographical Information Systems (GIS) network model for the creation of accessibility maps for wheelchair users. The measurement of barriers uses Digital Elevation Models, calculation of rolling resistance, and surveys in the field using hand-held GIS. A spatial database has been constructed which contains the pedestrian route network and barriers to navigation. A GIS application runs the model, providing a user-friendly interface to define and calculate routes through the pedestrian route network that take account of impedances to accessibility. The model, application and interface has been tested with wheelchair users and the route selection provides a good correspondence with patterns of route finding already established through experience. The interface and individually tailored maps generated, provide a tool suitable to assist wheelchair users new to an area; to enable better navigation for existing users, and a means for planners to consider the way in which access is restricted for wheelchair users in their designs for more inclusive urban environments.     

一种利用双侧凸包扩张模型的路径快速规划算法

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...     

基于网页旅游攻略的旅行线路规划

为帮助旅行者规划旅行线路,以旅游攻略为数据源,针对旅行线路规划问题中可选景点的动态性问题,根据传统车辆路径问题求解方法中两阶段法的先分组再定路线的策略,重点研究并设计改进了一种基于攻略中景点出现频率的先分组再定路线的启发式旅行线路规划策略用于自动规划旅游行程。试验结果表明,使用本文所提出的方法生成的旅游线路,时间分配更加合理,游览的景点间路程更短,线路的游览时间与景点间距离的费效比更高,对于游客规划旅行线路有着很大的现实意义。     

空天网格化星间通视及路由路径规划算法

通信、导航、遥感一体的天基信息服务系统的建设将对跨境实时通信、动目标全球跟踪、灾害快速响应等提供有力保障,同时也对高效的网络通信,特别是卫星路由规划算法提出了新的要求.为优化通信链路,进一步降低时延,充分利用网格空间关系直视、编码计算效率高的优势,提出了卫星星座空间互联网格化计算方法.基于 GeoSOT-3D(geog...     

最短路径算法在旅游线路规划中的应用——以庐山为例

本文以庐山旅游风景区为例,以一日游为主题,结合旅游景区景点知名度和各景点的停留时间,改进了G IS中的最短路径算法,利用VC++分析旅游区内各个景点之间的最短路径关系,得出该旅游区内的三条较合理的不同主题的一日游路线。通过本文的研究,希望能加强对庐山风景区的开发力度,促进庐山风景区的发展,并最终能推广G IS在旅游线路规划中的应用。     

面向道路网VGI数据的匹配与融合方法

自发地理信息(VGI)是一种新兴的地理数据采集方式,具有数据更新快、细节丰富、覆盖范围广等优势。利用VGI数据可以对道路网实现快速更新;但是由于VGI数据是非专业自发共享的,且数据采集时多使用非专业设备,所以存在数据质量不高的问题。大量VGI数据对同一地理要素的重复采集与融合处理则可改善数据的质量,文中以多人采集的道路网数据为例,结合矢量要素的匹配与融合理论,设计一种适用于道路网VGI数据的匹配与融合算法。首先在路段结点处建立缓冲区进行结点匹配,再根据路段距离相似度进行路段匹配,最后再利用Delaunay三角剖分融合算法对匹配后的同名路段进行融合。将匹配融合后的道路网与原始道路网VGI数据及Google影像图叠加对比分析,结果表明利用本文算法可有效地实现道路网VGI数据的匹配与融合。     

基于图的语义室内导航模型构建研究

室内空间模型是室内导航的基础和关键所在,针对当前多数室内空间模型在建模过程中只考虑部分导航相关的影响因素,适用范围有限这一问题,结合室内导航特点,综合考虑用户室内移动特征、几何和语义信息表达、路径规划效率3个方面的建模影响因素,提出一种基于图的语义室内导航模型。基于图论的方法构建室内导航概念模型,然后在概念模型的基础上提出具体的几何图模型构建方法和语义信息表达方式,设计图模型中节点和边的数据结构,最后研究将该模型用于不同情景下室内路径规划的具体流程。     

交通限制条件下的最短路径算法分析与优化

通过对交通网络本身的特点及要求的分析与研究，介绍了一些适合道路网的经典最短路算法和数据存贮模式，探讨了在交通网络路线优化过程中需要特别处理的几个问题，如路口延误、禁行状态等，并在理论上给出了相应的解决方案。最后给出了一个路径搜索的实例。     

顾及地形起伏的步行最优路径分析算法

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。     

Understanding Design with VGI using an Information Relevance Framework

Volunteered Geographic Information (VGI) has the potential to offer benefits to end‐users over and above those of Professional Geographic Information (PGI). A multi‐methods approach, consisting of participatory observation, focus groups and diary studies, was used to study how VGI and PGI were actually used by a target user group. A theoretical framework of information relevance was used to understand the attributes of information that were most important in relation to the characteristics of the users' activity and their community. The key finding was that the discussion amongst GIS designers should not be whether to choose VGI or PGI as the information data set, but to consider which combination of VGI and PGI relating to different geographic features and task characteristics would best meet the users' needs. VGI is likely to be most relevant to the user when a geographic feature is dynamic rather than static in nature, and can also provide a level of detail that is unlikely to arise through PGI. These findings have implications for how different forms of information are most effective for different usage situations. Above all, a case is presented for the implementation of User Centred Design (UCD) principles when integrating VGI and PGI together in a single mashup‐based product.     

基于不同交通工具多约束条件的最短路径算法研究

多约束条件下的最短路径选择可以满足用户的出行需求,然而不同的交通工具在相同起始点下最短路径选择存在很大差异。为了满足多用户的出行需求,基于不同交通工具的多约束条件,对传统的Dijkstra算法进行改进,由传统的基于单约束条件向多约束条件改进,并对最短路径选择的准确程度进行优化。通过实例,验证算法的可行性和准确程度。     

众源地理信息研究现状与展望

众源地理信息作为新型地理信息模式,是指由互联网用户借助交互式平台,通过直接上传传感器数据或提供数字化劳动而贡献的地理信息数据。近20年来,众源地理信息热度上升,并受到越来越多研究者的关注,正在逐渐成为一种重要的地理信息数据来源。本文对近十几年来关于众源地理信息的中文和英文文献进行了系统性的分析与研究,力图展现出众源地理信息研究的发展现状,同时以这些研究发现的规律为基础,结合当前的国际形势,探讨了众源地理信息的发展机遇与挑战,同时对发展自主众源地理信息给出了建议。