Turn calculations for the indoor application of the fewest turns path algorithm

ABSTRACT

Present-day indoor navigation systems are often not well adapted to the specific needs and requirements of its users. This research aims at improving those indoor navigation systems by providing navigation support that cognitively closer to user preferences and behaviour. More specifically, the focus is on the implementation of an accurate turn calculation method in a turn minimization algorithm, aiming to lower the complexity of routes and route instructions. This new-introduced perception-based turn calculation procedure is based on a direct door-to-door walking pattern, and, in contrast to previous algorithms, independent of the underlying indoor network type. It takes into account the effects of geometry of indoor space on human movement. To evaluate its functioning, both the traditional algorithm and the proposed perception-based algorithm are applied in the fewest turns path algorithm. It is demonstrated that the proposed algorithm accurately calculates turns in alignment with people’s perception. The implementation of the calculation algorithm in the fewest turns path algorithm also allows future applications in indoor simplest path algorithms, and overall contributes to cognitively richer indoor navigation systems.     

Campus Field Exercises for Introductory Geoscience Courses

Abstract

Field trips are essential for learning geoscience, but can be logistically challenging for introductory-level courses with large enrollments. Transporting large numbers of undergraduate students to roadway or stream bank exposures can be time consuming, expensive, and unsafe. To address this problem, the author designed three campus-based field exercises for an introductory geoscience course. Students collected and analyzed data from campus features to learn about rock weathering, retaining wall stability, and stream flow. They preferred outdoor campus exercises over indoor exercises, because they were more realistic, interesting, and interactive. The outdoor exercises utilized features common to many college campuses and thus could easily be implemented elsewhere. While the campus exercises do not replace a need for conventional road trips in upper-level courses, they are an effective way to introduce fieldwork in large introductory-level courses.     

室内定位数据分析与应用研究进展

现代人文地理学的研究越来越多地关注人的时空行为,而获取个体在出行活动中的时空位置数据是研究人类时空行为的前提。受数据获取技术的限制,之前对时空行为的研究主要集中在室外空间。随着室内定位技术的出现和应用,这类研究由室外空间扩展至室内空间。室内定位技术和方法较多,但从数据的角度来看,根据数据获取中使用定位方法的不同,可将室内定位数据分为几何位置数据、指纹位置数据和符号位置数据3类。目前,基于室内定位数据的研究可以归结为以下4个方面,即：人在室内的时空分布、人在室内的移动模式、人在室内的行为习惯及属性推断、人与室内环境的交互作用。然而,总体上目前的研究还处于探索阶段,理论和方法体系尚未成熟。本文认为后续的研究中需要关注以下问题：①数据获取方面。相对于蓝牙、射频识别、红外等定位技术,“智能手机+WiFi”模式的定位系统具有覆盖范围广、成本低廉、无需专门设备支持、易与用户交互等优势,是一种最具应用前景的室内定位技术;②研究内容方面。时空行为特征的研究是基础,个体属性推断及个体与环境的相互作用形式和机理研究将是重点,多时空尺度数据融合分析是一种趋势;③科学伦理方面。室内定位涉及微观尺度人类活动的记录,隐私保护问题需要高度关注。     

A Sustainability Initiative to Quantify Carbon Sequestration by Campus Trees

Abstract

Over 3,900 trees on a university campus were inventoried by an instructor-led team of geography undergraduates in order to quantify the carbon sequestration associated with biomass growth. The setting of the project is described, together with its logistics, methodology, outcomes, and benefits. This hands-on project provided a team of students with several learning opportunities including an introduction to carbon sequestration, basic arboriculture, field-based measurements, mapping, geographic information systems, and biogeography concepts. A GIS geodatabase was produced containing information on tree location, species, size, biomass, carbon content, and annual CO₂ sequestration, which was later customized for integration into campus facilities management.     

“Is there any time left for walking?” Physical activity implications of suburban commuting in the Barcelona metropolitan region

ABSTRACT

The present study delves into the explanatory factors of the walking patterns of residents in metropolitan regions, who tend to be pressed for time when travelling to their daily destinations or activities. We particularly focus on the effects of the commuting distance on the amount of walking that can be achieved, which has health, socioeconomic and environmental implications. This study confirms the potential benefits of using smartphone tracking data to examine walking patterns. To enable this, a smartphone tracking application was developed to obtain accurate mobility data from a group of adults (n = 93) residing in the Barcelona Metropolitan Region (Spain) and have to commute to a suburban university campus that can only be reached by using motorized transport modes. The results highlight the commuting distance and employment status as strong determinants of the amount of walking time achieved by this study group. Moreover, it was determined that among transit users, the commuting distance of male commuters was negatively associated with walking when compared with female transit users, whereas explanatory factors for private transport users bore insignificant results. Smartphone devices proved their potential as an effective and useful source of data in transportation and health research.     

基于P2P架构的位置服务

基于位置服务技术对地理信息系统和全球定位系统的发展和应用研究具有重要意义。概述基于位置服务的体系架构研究现状,给出基于P2P架构的位置服务模型。介绍该模型所涉及的相关技术,给出基于P2P架构的位置服务的原型实现PLbs。以交通信息系统为例进行研究,表明该模型能够提高基于位置服务系统的性能。     

Resolving Location Conflict with Standardized Space‐Cost Curves

Location analysis is concerned with the siting of facilities according to various cost criteria. Accessibility‐based cost criteria typically generate different optimal solutions (least‐cost location configurations) and location conflict arises. This paper outlines a new way to resolve such conflict–for single facilities sited in one‐dimensional space. Piecewise‐linear space‐cost curves for two well known criteria, efficiency and equality, are first transformed into standardized (Z‐score) curves. A family of hybrid space‐cost curves is then generated, where each member of the family reflects different fractional weights, w and 1‐w, being placed on efficiency and equality. Decision‐makers or users can assign these weights directly to the two criteria, thereby determining the most appropriate hybrid space‐cost curve used in resolving location conflict. This hybrid curve provides standardized, two‐criteria cost information for all possible facility locations.     

Ontologies of geographic information

This article explores the notion of a system of ontologies specifically designed for the needs of an information science. A framework for geographic information ontologies is outlined that focuses on geographic information constructs rather than on the direct representation of real-world entities or on linguistic terms. The framework takes the form of a generative hierarchy anchored by the notion of intentionality at one end and of a spatiotemporal field of potentially relevant information at the other. Two theoretical notions are used in the generation of the hierarchy. The first is the principle of semantic contraction, whereby, starting from a level of geographic information constructs specified so as to reflect user intentionality, semantically coherent domains of properties are removed over several steps until only the rudiments of a spatiotemporal information system are left. The second notion is that of object of discourse, which allows entities to be represented as the composites of geographic information constructs at the higher levels of the hierarchy, explicitly reflecting the connections between the purpose, function, appropriate internal constitution, and ensuing categorization of the entities represented. The framework's main contribution is thus twofold: first, it allows the notions of user purpose and object function to be directly built into geographic representations; second, it proposes a hierarchy of ontological levels that are linked by systematic semantic relations. Further, the framework presents an integrated view of object and field representations. It may also provide a novel perspective on a number of issues of ongoing interest in geographic information science.     

社会化校园与单位式校园空间的环境认知

中国社会转型带来的改革和建设不断促使大学校园走向开放与多元。针对单位式校园向社会化校园转变的趋势,研究两类校园空间的环境认知,对我国高校今后的发展与建设具有重要的理论意义。文章借鉴环境行为学方法,在探索性研究的基础上,采用调查问卷抽取环境认知与空间行为样本,通过边界与中心认知、行为地图缓冲区分析、网格统计和空间叠置等方法进行定性和定量分析,选取湖南师范大学和中南大学的本部校园作为对比案例,得出以下结论：1）社会化校园在被动地适应社会转型中融入城市系统,导致环境认知差于单位式校园;2）自然地理条件、功能格局和使用者主观意识相互交织,在时间因素的推动下,使社会化校园产生有别于单位式校园的空间行为格局;3）学生认知的发展性和社会转型环境影响的持续性,构建了环境认知与空间行为相互作用的机制。最后简单探讨了对大学校园建设的一些看法。     

Environmental decision support system project: an exploration of alternative architectures for geographical information systems

Abstract

Recent changes in information technology offer the opportunity to explore alternative architectures for geographical information systems (GIS) which might better support advanced applications. This paper describes the architecture and implementation of the environmental decision support system (EDSS), a prototype GIS tool kit. The architecture is based on a simple yet powerful systems model using only data collections, views and operations as the basic entity types. The design of the user interface, data management and data analysis within the model are outlined, with particular emphasis on the advanced facilities for which implementation is simplified by the architecture. A prototype applications system, BANKSIA, is also described.     

The use of immersive real-time 3D computer graphics for visualisation of dilution of precision in virtual environments

Dilution of precision (DOP) is a fundamental concept in satellite navigation and surveying. A deeper understanding of this concept can be achieved through the means of 3D immersive visualisation. In this article, we present a method for visualising and exploring the spatial variation of DOP and discuss its presentation within an immersive virtual environment. The work demonstrates a real-time simulation of global positioning system (GPS) satellite geometry, modelled and visualised within a virtual representation of the university campus. The number of satellites visible to the receiver is modelled in real time as a user walks through the university campus. During this process, the changing satellite geometry is visualised in both 3D and aerial views. Various DOP values update to the screen against a pseudo-realistic building backdrop as the user travels. Both the aerial views and the changing volumes of the tetrahedra drawn in 3D provide an effective way of interpreting why exceptionally large or small horizontal DOP and vertical DOP values can occur in an urban context. Because the factors affecting DOPs are inherently 3D, communicating the spatial uncertainty of global positioning system coordinates within an immersive stereo environment has been viewed as a particularly powerful communication tool by both undergraduate and postgraduate students studying GI Science.     

OutDet: an algorithm for extracting the outer surfaces of building information models for integration with geographic information systems

The integration of Building Information Modelling (BIM) and geographic information systems (GIS) is a promising but challenging topic to solve problems in construction industry. However, loading and rendering rich BIM geometric data and large-scale GIS spatial information in a unified system is still technologically challenging. Current efforts mainly simplify the geometry in BIM models, or convert BIM geometric data to a lower level of detail (LOD). By noticing that only exterior features of BIM models are visible from outdoor observation points, culling BIM interior facilities can dramatically reduce the computational burden when visualizing BIM models in GIS. This study explores the outline detection problem and presents the OutDet algorithm, which selects representative observation points, transforms & projects the BIM geometric data into the same coordinate system, and detects the visible facilities. Empirical study results show that OutDet can cull a large portion of unnecessary features when rendering BIM models in GIS. The use of outlines of BIM models is not an alternative but rather a supplementary approach for current solutions. Jointly using LOD and outer surface can help improve the efficiency of integrated BIM-GIS visualization.Because OutDet retains BIM geometry and semantics, it can be applied to more BIM-GIS applications..     

Prediction-based parking allocation framework in urban environments

ABSTRACT

Finding a parking space is usually challenging in urban areas. The literature shows that 30% of traffic congestion is caused by searching for parking spaces, which results in unnecessary energy consumption and environmental pollution. With the development of sensor technologies, smart parking guidance systems provide users with a variety of real-time parking space information. However, users cannot know whether the target parking space remains available upon arrival. Moreover, parking resources may be under competition when multiple users target the same open parking space. In this research, we develop a new framework named prediction-based parking allocation (PPA) that provides smart parking services to users. In PPA, we first construct a prediction model of parking occupancy and predict the subsequent parking availabilities. Then, we design a matching-based allocation strategy to assign users to selected parking spaces. To the best of our knowledge, this is the first study that combines occupancy prediction and space allocation simultaneously to address smart parking issues. Finally, we collect a real dataset from the SFPark on-street parking system for performance evaluation. According to experimental results, PPA can effectively increase the parking success rate and reduce costs, fuel consumption, and carbon emissions.     

Improvement of GIS graphics for analysis and decision-making

Abstract

Current geographical information systems (GIS) include functions to create cartographic output interactively or automatically. However, none of the systems presently incorporates mechanisms to ensure correct application of graphic functions. Many of today's users of GIS are not trained in the design and production of graphics and may create maps that confuse or mislead map users. Poorly-designed maps may obliterate the patterns in displayed information.

This article investigates ways to improve the quality of GIS graphical displays and increase their effectiveness for decision-making. Alternatives are presented for improving map design in GIS, ranging from non-technical efforts to enhancement of software functionality. Suggestions propose augmenting users' abilities to create maps in an automated environment, using an approach termed amplified intelligence: key decisions default explicitly to users, whose knowledge is amplified by a range of high-level tools to carry out map design operations automatically.     

An Approach to leaching Applied GIS: Implementation for Local Organizations

Abstract

Geographic information systems (GIS) is a fairly new and evolving curriculum area within geography and other disciplines at colleges and universities in the United States. The challenge of teaching underlying concepts of GIS functionality, the details of computer operation and software interfaces, as well as the contexts of various applications can be a difficult one. At Indiana University of Pennsylvania, a teaching strategy—Client-Life Cycle GIS Project Learning—has been introduced in which students in an upper level GIS course work with local organizations, faculty from other university departments, and governmental entities. This allows students with some GIS background to work with real clients; utilize and operationalize the concepts of the GIS Project Life Cycle; make the connection between data development, analysis, and applications development; provide expertise and needed data to local organizations; and see the utility and impact of their work. A group pilot project from the spring semester of 1998 is discussed to illustrate how students responded to this method of teaching GIS.     

Personalizing map content to improve task completion efficiency

Significant interaction challenges arise in both developing and using interactive map applications. Users encounter problems of information overload in using interactive maps to complete tasks. This is further exacerbated by device limitations and interaction constraints in increasingly popular mobile platforms. Application developers must then address restrictions related to screen size and limited bandwidth in order to effectively display maps on mobile devices. In order to address issues of user information overload and application efficiency in interactive map applications, we have developed a novel approach for delivering personalized vector maps. Ongoing task interactions between users and maps are monitored and captured implicitly in order to infer individual and group preferences related to specific map feature content. Personalized interactive maps that contain spatial feature content tailored specifically to users' individual preferences are then generated. Our approach addresses spatial information overload by providing only the map information necessary and sufficient to suit user interaction preferences, thus simplifying the completion of tasks performed with interactive maps. In turn, tailoring map content to specific user preferences considerably reduces the size of vector data sets necessary to transmit and render maps on mobile devices. We have developed a geographic information system prototype, MAPPER (MAP PERsonalization), that implements our approach. Experimental evaluations show that the use of personalized maps helps users complete their tasks more efficiently and can reduce information overload.     

A less‐is‐more approach to geovisualization – enhancing knowledge construction across multidisciplinary teams

The ‘less‐is‐more’ concept in interface design for computer applications has recently gained ground. In this article, the concept is adopted for a user‐centered design of geovisualization application. The premise is that using simple and clear design can lead to successful applications with improved ease of use. Over the last three decades, the development of GIS and geovisualization has seen a marked increase in the levels of interaction between the user, the system and the information. However, these enthusiastic advances in technology have not resulted in a significant increase in the number of users.

This article suggests that types of user interaction should not simply emphasize traditional GIS functions such as zooming and panning but move towards interaction based on facilitating the knowledge construction process. Considerations are made for the complexity of the system, the task at hand and the skills and limitations of the users. These elements are particularly important when maps act as the mediators in collaboration with users across disciplinary backgrounds. In such cases, the emphasis on simplicity and usability becomes as important as functionality. In these situations a geovisualization application designed for specific uses can maximize effective development of geographic knowledge.

In this article, a minimalistic design approach to geovisualization is adopted by creating a geographic profiling tool which shifts the emphasis from technological advances or interaction with the map to the interaction elements key to building the spatial knowledge of GIS experts and non‐experts alike. To evaluate this notion of ‘less‐is‐more geovisualization’ the profiling tool is evaluated according to usability matrices: efficiency, effectiveness and learnability. How well the Suburban Profiler contributes to these elements is assessed by conducting a video analysis of the types and forms of user interaction available. The video analysis demonstrates the usefulness and usability of the Suburban Profiler, providing proof of concept for ‘less‐is‐more geovisualization’.     

“Is there a bubble to burst?”-college students’ spatial perception of campus and the city,a case study of rhodes college in memphis,TN

ABSTRACT

This paper builds on the study of student geography by critically examining college students’ perceived space of a university campus and the surrounding urban space. Rhodes College is a liberal arts college situated in the city of Memphis. As a campus with a majority white population located in a predominately black city, Rhodes College exists within but often separate from the city. It serves as a perfect case study to investigate how the college students build relationships with the environment within and beyond the campus. By using mental mapping and focus groups, this research unpacks four spatialities that shape college students’ perception of the urban space: (in)activity space, (im)mobility, boundaries, and center. This research demonstrates that student geography can be gendered, classed and racialized. The perceived space is socially constructed, and is reinforced by the lived and material space. Finally, this paper provides implications to facilitate deeper connections between students, the campus, and the city.     

基于定位视频的车辆导航原型系统设计与关键技术研究

基于电子地图的导航系统相对抽象且缺乏沉浸感,不方便用户判别。为使导航效果更加直观和生动,该文提出基于定位视频的车辆导航思路,对车辆导航原型系统进行总体设计与实现,并探讨其关键技术。核心思想是建立道路定位视频(Geo-video)数据库,利用移动终端和固定目标的位置信息对定位视频数据库进行空间检索,将相应位置的视频图像传输给移动终端并实现路线和目标指引。试验证明该方法在技术上具有可行性。     

An exploration of spatial dispersion, pattern, and association of socio-economic functional units in an urban system

Hypotheses based on a set of socio-economic, cultural, and political functional units are examined. The geographic techniques employed in the study include spatial mean, standard distance, standard deviational ellipse, nearest neighbor analysis, and spatial analysis on a network: cross K function and network cross K function. The study not only explores the spatial pattern, distribution, and association of key socio-economic, cultural, and political units which could reveal internal structures and activities of an urban system, but also demonstrates a number of operational procedures that permit applications of traditional and advanced spatial analysis approaches in the study of real urban systems.