共查询到20条相似文献，搜索用时 125 毫秒
1.
《地理与地理信息科学》2016,(1)
随着移动互联网和街景地图的发展,基于360°全景影像的街景地图服务将成为移动互联网时代位置服务的主流趋势。该文提出了一种面向iOS移动端的全景地图应用构建方法。首先,提出基于球面模型的移动端全景场景构建、纹理贴图和渲染优化的技术方法;其次,针对移动终端应用模式,设计了面向移动终端的全景地图数据服务的技术框架;最后,采用移动端全景地图模型和数据服务框架,实现了iOS下移动端全景地图的开发。实验结果表明移动端全景浏览流畅,可以广泛应用在增强现实位置服务,具有很好的应用前景。 相似文献
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格网技术对GIS发展的影响 总被引：4，自引：0，他引：4
格网技术作为新一代的Web技术,必将深刻影响GIS的发展。格网计算为数据密集型空间分析提供了资源支持。数据格网为海量空间数据分布式存储、管理、传输、分析提供了一体化的解决方法。格网技术为VRGIS实时场景渲染和海量场景数据存储以及GIS互操作问题的解决提供了一种新思路。格网中的智能体组件动态组装应用软件将对GIS应用开发方式产生重大影响。通过建立空间信息格网可以实现中国GIS产业的跨越式发展。 相似文献
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格网技术作为新一代的Web技术，必将深刻影响GIS的发展。格网计算为数据密集型空间分析提供了资源支持。数据格网为海量空间数据分布式存储、管理、传输、分析提供了一体化的解决方法。格网技术为VRGIS实时场景渲染和海量场景数据存储以及GIS互操作问题的解决提供了一种新思路。格网中的智能体组件动态组装应用软件将对GIS应用开发方式产生重大影响。通过建立空间信息格网可以实现中国GIS产业的跨越式发展。 相似文献
4.
基于数据库存储方案的高性能瓦片地图服务研究 总被引：1，自引：0，他引：1
实时渲染与网络传输是影响WebGIS性能的两大因素,瓦片技术是改进系统性能的最佳选择,它通过对地图数据预先渲染、切片,有效减轻服务器处理压力,减少网络负载和响应延迟,但瓦片数据量庞大,磁盘存储碎片化,影响IO性能,数据可迁移性差,无论是数据备份、迁移或是恢复都耗时漫长。该文设计实现了一种新的基于文件数据库的瓦片存储方案,并将分布式缓存系统Memcached作为缓存支持集成在方案中,不仅克服了传统瓦片储存的缺陷,还在性能方面取得了优异的表现,是构建高性能瓦片地图服务的有益尝试。 相似文献
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该文提出和探讨了基于内容的虚拟地理场景检索与智能导航研究框架。该框架包括三维地理数据获取与模型创建,三维地理对象的识别与定位,三维地理场景的内容分析、检索与认知,基于内容的虚拟地理数据层次式描述与分类索引,地理场景智能导航以及基于内容的自适应虚拟地理数据网络传输等方面的研究方法和内容,有助于建立一种符合人类认知特点的人地关系和人地交互模型。最后,总结和分析了该技术在虚拟地理环境(VGE)研究中的地位和作用。 相似文献
7.
虚拟奥运环境系统的构建及"人文奥运"可视化表达研究 总被引：2，自引：1，他引：1
该文介绍构建虚拟奥运环境系统的相关原理和方法,应用Java和VRML语言,实现了基于客户机／服务器结构的系统原型。在系统中用户不但可以在三维虚拟场景中进行漫游和查询,而且还能以化身人和文本的方式进行交流与互动。此外,还从古代、现代、未来三个方面,对北京南北中轴线的时空演变进行可视化模拟表达与分析,从而体现了虚拟奥运环境系统中“人文奥运”的主题内容。 相似文献
8.
王琪 《地理与地理信息科学》2007,23(2):39-42
网络环境下进行二维电子地图与三维虚拟场景集成,关键问题之一是数据快速、有效地传输与表达。为了解决网络电子地图与三维虚拟场景集成过程中数据快速传输问题,该文讨论了空间数据多级存储、网络数据流压缩、矢栅数据有机结合、纹理模型及原型模型库等网络传输瓶颈解决方案和模型数据简化方法,为后续网络电子地图和三维虚拟场景集成系统的开发奠定基础。 相似文献
9.
基于文献分析方法,综合分析了数字地球的概念,总结了数字地球技术在城市规划中的应用.其主要包括:数据源扩展技术;定量分析技术;公众参与支持系统;动态监测系统;基于云计算模型与时态GIS的城市规划时空展示分析体系;城市规划教育与创新体系.认为凭借其多分辨率、三维动态可视化以及海量数据存储的特点,数字地球技术在城市规划中的应用将具有广阔的发展前景. 相似文献
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"数字黄河" 作为科学工程,是数字地球的组成部分.该文提出了数字黄河科学工程的框架,并依次论述了框架所包括的数字黄河科学工程的设计、数字黄河的空间基础设施、数据更新能力、虚拟现实与仿真、科学工程的网络以及应用工程.在此基础上提出了加强"数字黄河"基础研究、建立"数字黄河"科学工程示范和科学工程阶段性的建议. 相似文献
11.
Pilleriine Kamenjuk Anto Aasa Jaanus Sellin 《International journal of geographical information science》2017,31(7):1425-1447
Similar to every process involving quantitative research, the study of migration heavily depends on the data available for analysis. The available movement data limit the type of questions that can be asked, and as a result, certain aspects of human spatial mobility have yet to be examined. The development of information and communication technologies and their widespread adoption offers new datasets, methods and interpretations that make it possible to study social processes at a new level. For example, mobile positioning data can aid in overcoming certain constraints embedded in traditional data sources (such as censuses or questionnaires) for study of the connections between daily mobility and change of residence. This study presents a framework for mapping changes of residence using data from passive mobile positioning and an anchor point model to better understand the limits of these methods and their contribution to understanding long-term mobility. The study concludes that the most important considerations in monitoring change of residence using passive mobile position data include the continuity of the time-series data, the varying structure of the mobile tower network and the diversified nature of human mobility. The fine spatial and temporal granularities of passive mobile positioning data allow us to study human movement at a detailed scale. 相似文献
12.
信息时代移动社会理论构建与城市地理研究 总被引：16，自引：4，他引：12
以信息技术进步为核心的信息革命已经成为推动国家、区域与城市社会经济发展及其快速转型的重要动力,并持久、深刻地冲击和改变着工业革命以来人类对社会经济及其空间结构形成的固有认识。当前,移动通信技术的进步及其应用,与高速铁路的加快建设、城市区域化的加速和智慧城市的建设一起,正将世界带入一个全新的移动信息时代。由于时间和空间概念的重新定义,全新时空观的出现,使得以空间问题为核心内容的城市地理学面临着根本性的变革。在移动信息技术的支撑下,城市地理学的研究范式、方法和内容都开始发生巨大的变化,传统的理论框架已逐渐不能满足当前研究的需要。本文重点分析了移动信息技术影响下的地理空间与网络信息空间的变化,提出了基于移动信息技术的移动社会理论框架。进而对移动信息时代城市地理学的研究方法、研究重点进行了探讨,希望运用城市地理学的研究更好地服务于移动信息时代的城市与区域的发展、规划与管治。 相似文献
13.
全球手机贸易网络演化特征研究 总被引：3，自引：2，他引：1
基于复杂网络方法,运用Pajek、Ucinet、Gephi等软件,构建全球手机产业贸易网络,探究2001-2016年全球手机产业贸易网络结构及其演化过程。根据研究发现全球手机贸易网络呈现稠密化发展趋势,网络整体遵循“核心-边缘”的圈层结构,结构内部不断演化和重组;全球手机贸易网络呈现由双核主导向多核演变,空间格局上形成由欧美日发达国家向东亚发展中国家的转移趋势;全球手机贸易网络的四大子群网络板块特征明显,且随着时间的发展而发生变化。 相似文献
14.
Yingjie Hu Krzysztof Janowicz Yuqi Chen 《International journal of geographical information science》2016,30(6):1228-1249
Recent years have witnessed a large increase in the amount of information available from the Web and many other sources. Such an information deluge presents a challenge for individuals who have to identify useful information items to complete particular tasks in hand. Information value theory (IVT) from economics and artificial intelligence has provided some guidance on this issue. However, existing IVT studies often focus on monetary values, while ignoring the spatiotemporal properties which can play important roles in everyday tasks. In this paper, we propose a theoretical framework for task-oriented information value measurement. This framework integrates IVT with the space-time prism from time geography and measures the value of information based on its impact on an individual’s space-time prisms and its capability of improving task planning. We develop and formalize this framework by extending the utility function from space-time accessibility studies and elaborate it using a simplified example from time geography. We conduct a simulation on a real-world transportation network using the proposed framework. Our research could be applied to improving information display on small-screen mobile devices (e.g., smartwatches) by assigning priorities to different information items. 相似文献
15.
Olle Järv Henrikki Tenkanen Tuuli Toivonen 《International journal of geographical information science》2017,31(8):1630-1651
Novel digital data sources allow us to attain enhanced knowledge about locations and mobilities of people in space and time. Already a fast-growing body of literature demonstrates the applicability and feasibility of mobile phone-based data in social sciences for considering mobile devices as proxies for people. However, the implementation of such data imposes many theoretical and methodological challenges. One major issue is the uneven spatial resolution of mobile phone data due to the spatial configuration of mobile network base stations and its spatial interpolation. To date, different interpolation techniques are applied to transform mobile phone data into other spatial divisions. However, these do not consider the temporality and societal context that shapes the human presence and mobility in space and time. The paper aims, first, to contribute to mobile phone-based research by addressing the need to give more attention to the spatial interpolation of given data, and further by proposing a dasymetric interpolation approach to enhance the spatial accuracy of mobile phone data. Second, it contributes to population modelling research by combining spatial, temporal and volumetric dasymetric mapping and integrating it with mobile phone data. In doing so, the paper presents a generic conceptual framework of a multi-temporal function-based dasymetric (MFD) interpolation method for mobile phone data. Empirical results demonstrate how the proposed interpolation method can improve the spatial accuracy of both night-time and daytime population distributions derived from different mobile phone data sets by taking advantage of ancillary data sources. The proposed interpolation method can be applied for both location- and person-based research, and is a fruitful starting point for improving the spatial interpolation methods for mobile phone data. We share the implementation of our method in GitHub as open access Python code. 相似文献
16.
Inferring properties and revealing geographical impacts of intercity mobile communication network of China using a subnet data set 总被引：3，自引：0，他引：3
This article provides a novel and practical approach for investigating the characteristics of intercity telecommunication network whose overall and complete information is unavailable. Using a mobile phone call data set covering 4.39 million subscribers registered in a particular region, we construct two intercity mobile communication subnets and infer characteristics of the whole intercity mobile communication network of China. Results confirm that intercity communication intensity is characterized by the gravity model. The communication intensity based on mobile call number decreases along the distance with a scaling exponent 0.5, whereas the scaling exponent for the communication intensity based on mobile call duration is 0.4. Moreover, we uncover the rank-size distribution of tie strength (mobile call number and duration) between a city and its neighbours. The rank-size law of tie strengths between cities is mainly determined by the rank-size distribution of cities. The distance between cities plays a less decisive role than the size distribution in the network, but significantly impacts mobile communication patterns. The call duration of individual intercity mobile communication is generally positively correlated to the communication distance, explaining why the distance decay of communication intensity based on call durations is slower than that based on call numbers. The contribution of this research is twofold. First, we identify the distance decay effect in intercity mobile communications of China and uncover the dominant impact of the rank-size distribution of cities. Second, a method for estimating the properties of the whole network according to the observed interactions of its subnets is developed. 相似文献
17.
Under the initiative of “encouraging 300 million people to participate in ice and snow sports” and the guidance of the ‘Evidence-based’ policy-making process, this study takes the Hierarchical Model of Leisure Constraints as the theoretical framework to empirically explore the constraints influencing the participation of residents in Southern China in ice and snow sports. After factor analysis, the constraint dimension of residents’ participation was obtained, and the constraints of participants and non-participants were evaluated and compared by Propensity Score Matching (PSM). The results indicate that Chengdu residents have potential interest in and demand for winter sports, and the constraint dimensions are: facilities and services, companions, time, and personal feelings. The predisposition scores of the experimental group and the control group revealed that the constraints on interest, relevant knowledge and skills, and personal feelings of the participating group were significantly lower than those of the non-participating group, while the other constraints were not significant. We suggest that efforts should be made to increase the effective supply according to local conditions in order to reduce structural constraints, and the social attributes should be integrated into ice and snow sports to resolve the inter-personal constraints. 相似文献
18.
Lin Hui Gong Jianhua Xu Bingli Qi Hua 《International journal of geographical information science》2013,27(4):607-621
To improve the efficiency of planning and designing silt dam systems, this article employs theories and technologies of collaboration and distributed virtual geographic environments (VGEs) to construct a collaborative virtual geographic environment (CVGE) system. The CVGE system provides geographically distributed users with a shared virtual space and a collaborative platform to implement collaborative planning. Many difficulties have been found in integrating data resources and model procedures for the planning of silt dam systems because of their diversity in heterogeneous environments. Unlike most of the current distributed system applications, the proposed CVGE system not only supports multi-platform and multi-program-language interoperability in the dynamically changing network environment, but also shares programs, data and software in the collaborative environment. Based on creating a shared 3D space by virtual reality technology, agent and grid technologies were tightly coupled to develop the CVGE system. A grid-based multi-agent system service framework was designed to implement this new paradigm for the CVGE system, which efficiently integrates and shares geographically distributed resources as well as having the ability to build modelling procedures on different platforms. At the same time, mobile agent computing services were implemented to reduce the network load, process parallel tasks, enhance communication efficiency and adapt dynamically to the changing network environment. Using Java, JMF (Java Media Framework API), Globus Toolkits (GT) core, Voyager, C++, and the OpenGL development package, a prototype system was developed to support silt dam systems planning in the case study area, the Jiu-Yuan-Gou watershed of the Loess Plateau, China. Compared with the traditional workflow, the CVGE system can reduce the workload by between one third and a half. 相似文献
19.
为解决乡村振兴中乡镇政府如何选择正确产业和如何制定合理产业政策2个重要问题,运用新结构经济学“增长甄别与因势利导框架”分析并提出乡镇“有为政府”产业政策演化的逻辑框架：1）选择产业,依据“两步六轨法”选择具备相似资源禀赋、约束条件的产业。2）政策制定,针对筛选出的产业制定合理的政策内容、选择适当的政策工具,以支持产业发展。以该逻辑框架为依据分析了云南省西双版纳州勐罕镇的产业现状、目标乡镇比较优势产业,发现勐罕镇领先型产业为菠萝种植业,应通过引进菠萝深度加工企业,建设营销网络、运输网络,提供市场信息支持产业发展;转进型产业为传统种植业和特色养殖业,应通过建立冷链物流等基础设施、培训农户种养能力,提高农户市场参与度;“弯道超车型”产业为酒类制造和傣药生产等,应通过联合农户开发制造技术体系,协助注册品牌商标,建设生产和成品制造基地等促进产业发展,从而完成了逻辑框架的实践检验。总体上,因势利导逻辑框架既结合实际又着眼未来,为乡镇政府的产业政策决策提供了理论指导和经验借鉴。 相似文献
20.
Tian Lan 《International journal of geographical information science》2013,27(11):2305-2333
ABSTRACTSchematic maps are popular for the representation of transport networks. Many automated methods have been developed to generate such maps. In these methods, optimization techniques work with various sets of constraints. Most of these constraints govern geometric properties of individual features. A few constraints address relationships among features, but none explicitly deal with the main structure of an entire network. We believe that preservation of main structure is the most important and preservation of relative relations is helpful. This is because human perception follows a global-to-local process. These constraints have recently been formed into four general principles, with two for global structure and two for relativity of features. This study develops an automated method by integrating these principles into the mixed-integer programming (MIP) framework. Experimental evaluations have been conducted with two sets of real-world transit networks. In comparison to the existing method, the proposed method has smaller fractal dimensions, better computational performance and higher scores in terms of clarity, recognition of major lines, visual simplicity and satisfaction. Therefore, it is concluded that the proposed method can generate schematic maps with improved clarity and aesthetics. The idea in this study is also helpful for the design of other visual representations. 相似文献