基于本体语义的地理信息服务发现

基于本体语义研究地理信息服务发现问题.将加权语义距离和Wu-Palmer法相结合并进行改进计算本体概念语义相似度.引入服务接口依赖关系,提出支持接口多态性的本体语义地理信息服务输入输出匹配方法.最后开发实验原型对基于本体的地理信息服务匹配方法进行实验与分析.     

北京市测绘成果管理的现状与建议

测绘成果是重要的信息资源,总结了现有测绘成果管理的国家政策法规.对北京市和兄弟省市在政策法规与标准建设、机构建设、测绘成果的汇交与发布进行了对比分析.提出进一步完善测绘成果管理政策法规;成立专门的测绘成果管理机构,加强对测绘成果汇交情况的监管;建立与测绘成果汇交有关的数据标准;加大经费投入,保障测绘成果管理工作的顺利进行;集成整合规划监督测量成果,降低测绘成果生产成本;研发相关网站,促进测绘成果分发共享,大力开展测绘产品增值服务.     

一种分布式空间数据的服务聚合模型

数据源的异构、GIS服务规范的自定义以及分布式存放等问题制约了空间信息的广泛共享和应用。本文基于空间信息共享平台建设,围绕服务动态聚合的思想,结合OGC的标准规范和技术思想,在具有REST风格的GIS服务的基础之上,提出了一个服务聚合模型,通过该模型实现了分布式存放的异构瓦片数据的无缝集成显示以及网络要素服务的功能共享。     

An integrated heterogeneous web service retrieval via combination of instance- and metadata-based schema matching method

Schema matching is a critical step in the integration of heterogeneous web service, which contains various types of web services and multi-version services of the same type. Mapping loss or mismatch usually occurs due to schema differences in structure and content and the variety in concept definition and organization. Current instance schema matching methods are not mature enough for heterogeneous web service because they cannot deal with the instance data in web service domain and capture all the semantics, especially metadata semantics. The metadata-based and the instance-based matching methods, in the case of being employed individually, are not efficient to determine the concept relationships, which are crucial for finding high-quality matches between schema attributes. In this paper, we propose an improved schema matching method, based on the combination of instance and metadata (CIM) matcher. The main method of our approach is to utilize schema structure, element labels, and the corresponding instance data information. The matching process is divided into two phases. In the first phase, the metadata-based matchers are used to compute the element label similarity of multi-version open geospatial consortium web service schema, and the generated matching results are raw mappings, which will be reused in the next instance matching phase. In the second phase, the designed instance matching algorithms are employed to the instance data of the raw mappings and fine mappings are generated. Finally, the raw mappings and the fine mappings are combined, and the final mappings are obtained. Our experiments are executed on different versions of web coverage service and web feature service instance data deployed in Geoserver. The results indicate that, the CIM method can obtain more accurate matching results and is flexible enough to handle the web service instance data.     

基于等分辨率的全球四叉树网格剖分模型研究

针对目前我国地理信息公共服务平台建设情况和我国地理信息服务特点进行总结分析,提出基于SOA的多级树结构目录服务模型,实现地理信息服务的集成、控制和共享,为地理信息公共服务平台建设服务的集成与共享提供了新思路。     

XXIII INTERNATIONAL GEOGRAPHICAL CONGRESS,U.S.S.R.

Edward Jarvis in 1850 first demonstrated that admission rates to mental hospitals decrease with increasing residential distance, a relationship known today as “Jarvis's Law.” His original data are presented, mapped, and examined by regression analysis to better understand spatial and temporal patterns of mid-19th century mental hospital utilization. Distance substantially affected admission rates to a radius of about 60 miles from the institution in Massachusetts; and there was strong distance decay in the other states examined. For all twelve states, there was a positive association between age of the hospitals and admission rates, which also decreased with increasing residential distance.     

Ecosystem services in practice: Challenges to real world implementation of ecosystem services across multiple landscapes – A critical review

Ecosystem services (ES) and ecosystem services assessment (ESA) have become common parlance in the environmental field. Scientists, policy-makers and activists have promoted the ES approach as a means of conveying the extent of threats to natural ecosystems with the goal of crafting socially acceptable and effective policy to address ecological threats and biodiversity conservation. Yet there are some significant challenges to wide acceptance of the ES approach which hinder its absorption into the mainstream geography literature. This paper reviews the historical development of the ES approach focusing on its relevance to applied geography at different stages of its development, describes the present state-of-the-art of ES, and synthesizes the results from several seminal papers and reports. I posit that there are two major stumbling blocks: 1) the difficulty of simplifying complexities between services so that statutory planning processes can incorporate the approach, and 2) the lack of cross-landscape assessment methods and examples. If we focus on the most immediately surmountable challenges to the ES approach much progress could be made in a short time. The subsequent and final substantive section of this review summaries these challenges and offers some suggestions for moving forward.     

Pervasive geo-security – a lightweight triple-A approach to securing distributed geo-service infrastructures

Security has recently become a major concern in distributed geo-infrastructures for spatial data provision. Thus, a lightweight approach for securing distributed low-power environments such as geo-sensor networks is needed. The first part of this article presents a survey of current security mechanisms for authentication and authorisation. Based on this survey, a lightweight and scalable token-based security infrastructure was developed, which is tailored for use in distributed geo-web service infrastructures. The developed security framework comprises dedicated components for authentication, rule-based authorisation and optimised storage and administration of access rules. For validation purposes, a prototypical implementation of the approach has been created.     

A framework design for the Chinese National Disaster Reduction System of Systems (CNDRSS)

China is one of the most disaster-prone countries in the world. Currently, the disaster prevention and relief mechanism in China is mainly based on single disaster types and is implemented by different ministries and divisions in single administrative regions. Subsequently, the available resources, including data, services, materials, and human resources, cannot be shared and used effectively. Based on the idea of an observation system of systems and a business system of systems, this paper presents an integrated framework for a Chinese National Disaster Reduction System of Systems (CNDRSS) to address this issue. The CNDRSS framework aims to achieve data sharing and collaboration among different disaster-related ministries/institutions by providing one-stop services for all phases of disaster management and linking together existing and planned disaster-related business systems and observation systems. The key technologies use federated databases and a web service to integrate multiple disaster management systems among different ministries/institutions and a sensor web to integrate airborne, space-borne, and in-situ observations through the web service. These event-driven focused-services connecting the various observations, processing, and mapping processes can meet the requirements for complex disaster-chain systems.     

基于GNSS CV的精密时间服务系统的设计与实现

通过研究GNSS(global navigation satellite syetem,全球导航卫星系统)共视远程时间传递技术,并结合现代网络通信技术,搭建了基于GNSS CV(common-view,共视)的精密时间服务系统的硬件平台。利用中国科学院国家授时中心保持的精确时间UTC(NTSC)和GNSS共视接收机观测数据,实现了用户与国家授时中心之间的在线数据传输和比对处理,为用户时间与UTC(NTSC)之间的高精度时间同步提供了一种解决方案。