波段选择协同表达高光谱异常探测算法

高光谱遥感影像具有光谱分辨率极高的特点,承载了大量可区分不同类型地物的诊断性光谱信息以及区分亚类相似地物之间细微差别的光谱信息,在目标探测领域具有独特的优势。与此同时,高光谱遥感影像也带来了数据维数高、邻近波段之间存在大量冗余信息的问题,高维度的数据结构往往使得高光谱影像异常目标类和背景类之间的可分性降低。为了缓解上述问题,本文提出了一种基于波段选择的协同表达高光谱异常探测算法。首先,使用最优聚类框架对高光谱波段进行选择,获得一组波段子集来表示原有的全部波段,使得高光谱影像异常目标类与背景类之间的可分性增强。然后使用协同表达对影像上的像元进行重建,由于异常目标类和背景类之间的可分性增强,对异常目标像元进行协同表达时将会得到更大的残差,异常目标像元的输出值增大,可以更好地实现异常目标和背景类的分离。本文使用了3组高光谱影像数据进行异常目标探测实验,实验结果表明,该方法与其他现有高光谱异常目标探测算法对比,曲线下面积AUC(Area Under Curve)值更高,可以更好地实现异常目标与背景分离,能够更有效地对高光谱影像进行异常目标探测。     

分布异构空间数据协同编辑关键技术研究

分布式环境下空间数据库的异构、多源、多平台特性,使不同系统之间难以实现协同处理。为实现分布异构空间数据的协同编辑,在研究网络要素服务(Web Feature Service,WFS)规范的基础上,对WFS规范中的锁定、编辑操作进行了改进,同时将发布订阅机制引入到基于WFS的网络空间数据编辑处理中,使其能够适应协同编辑的需求,并以此为基础提出了基于WFS的一致性控制机制、编辑机制和发布订阅机制,最后建立了相应的原型系统以验证其有效性。     

CVE中多种视点视图导航效果研究

协同虚拟环境是网络技术与虚拟现实技术相结合的产物,将单用户虚拟环境扩展为多用户的网络化虚拟环境,实现群组协同工作.目前,协同虚拟环境系统已经在科学可视化、协同设计、战争模拟等很多领域得到了广泛应用.在单用户虚拟环境中导航与多用户的协同虚拟环境中导航是完全不同的,文中论述了协同虚拟环境导航的特点以及导航与视点的关系,探讨了常用的协同虚拟环境三种视点视图界面的导航及其效果,并进行了相关实验测试.     

协同空间决策的概念、过程与特点研究

对空间决策支持系统和计算机系统协同工作环境进行系统分析和总结，概括了较为完整的协同空间决策概念，提出了协同空间决策的空间问题协同分析、方案生成与可视化、方案分析、方案表决等基本过程。在此基础上，作者详细分析了协同空间决策的复杂性、交互可视化、多用户参与、方案探索性分析、多层次协同等基本特征。     

Web Use in Geographical and Environmental Education: An International Survey at the Primary and Secondary Level

This article aims to study Web use and Web-based co-operation and collaboration in geographical and environmental education at the primary and secondary level around the world. Recent trends and future opportunities and challenges are taken into account. The theoretical part of the study considers Web use and different forms of Web-based co-operation. Web use and co-operation in education are classified as co-operative learning, collaborative learning or communal learning. Web use in geographical and environmental education is noted to be growing in significance. Web-based co-operation at any level of intensity is associated with many opportunities and challenges. The empirical part of this study involves a survey of geographical and environmental education researchers in various countries about their views of Web use in education. The results of this survey indicate that the Web in general finds minimal use in geographical and environmental education. As access to the Web is limited and only some pupils can use it, co-operation, particularly collaborative learning on the Web, is still rare in geographical and environmental education. The most often used application is e-mail. Researchers recognise the potential of the Web to enhance local, national and international co-operation, and to facilitate a better understanding of geographical and environmental issues at the grass-root level. Web-based learning can also help to increase and deepen the pupils' cultural understanding. Before that, however, problems in access, costs and teacher training must be solved. This revised version was published online in August 2006 with corrections to the Cover Date.     

Research relevance, 'knowledge transfer' and the geographies of CASE studentship collaboration

The Co-operative Awards in Science and Engineering (CASE) studentship programme of the UK Research Councils provide one example of wider efforts internationally to encourage so-called 'knowledge transfer' and thereby harness publicly supported university research more closely to the goals of national competitiveness, regional economic development and local regeneration. In this paper we describe the implications of how the various UK research councils have interpreted the objectives and beneficiaries of 'knowledge transfer', both for the relative opportunities available to human and physical geographers for collaboration through CASE and for the sorts of values that their research must serve. Then, we draw on unpublished data from the Economic and Social Research Council (ESRC) to explore the geographies of CASE studentship allocation and participation. The broad regional and institutional patterns of participation we describe have important implications for ongoing debates in the UK about research selectivity and the role of the university as an engine of local development, while the striking disciplinary patterns of CASE participation, and in particular the overwhelming success of geographers in this competitive programme, provide an opportunity to reassess claims about whether and for whom geographical research is relevant.     

Satellite image analysis using crowdsourcing data for collaborative mapping: current and opportunities

ABSTRACT

Researchers are continually finding new applications of satellite images because of the growing number of high-resolution images with wide spatial coverage. However, the cost of these images is sometimes high, and their temporal resolution is relatively coarse. Crowdsourcing is an increasingly common source of data that takes advantage of local stakeholder knowledge and that provides a higher frequency of data. The complementarity of these two data sources suggests there is great potential for mutually beneficial integration. Unfortunately, there are still important gaps in crowdsourced satellite image analysis by means of crowdsourcing in areas such as land cover classification and emergency management. In this paper, we summarize recent efforts, and discuss the challenges and prospects of satellite image analysis for geospatial applications using crowdsourcing. Crowdsourcing can be used to improve satellite image analysis and satellite images can be used to organize crowdsourced efforts for collaborative mapping.     

Application of ICTs in Airspace Management and Collaborative Decision-Making—Analyzing the Risk Avoidance in the Condition of Risky Weather as an Example

The application of ICTs makes structural change of the development and effective utilization of airspace. Next generation air transportation system (NextGen) includes new automation concepts with automated information to support the traffic control decision-making. As a result, in the field of academia and industry, air traffic controllers integrate information automatically while making decisions to change the previous manually integrated and decided pattern. The safety ability of airspace is reduced and airspace system is endangered under risky weather conditions of airspace. So there is an urgent demand for new information and communication technologies. The paper is an overview of the information constitution and support of NextGen and provides the study of the development of technique of airspace collaborative decision-makings to confirm the new features based on ICTs. It contains basic application-the input of data and output of the routes of airspace management and collaborative decision-making, and general application-the choose of probability nets of avoiding risky weather, and special application-the affection in the management of the air routes, which are made up of position and direction. The research shows the accurate schedule characteristics of airspace management and collaborative decision-making based on ICTs, which made the space accurate by time accurate. Second, the visualization of airspace management and collaborative decision-making based on ICTs made the maps of flight path under mobile data quickly generated. This could make the fully development and utilization of national airspace, ensure safety, and reduce air traffic controllers’ workload and the costs in delaying and operating in risky weather.     

A location-aware GIServices quality prediction model via collaborative filtering

The quality of GIServices (QoGIS) is an important consideration for services sharing and interoperation. However, QoGIS is a complex concept and difficult to be evaluated reasonably. Most of the current studies have focused on static and non-scalable evaluation methods but have ignored location sensitivity subsequently resulting in the inaccurate QoGIS values. For intensive geodata and computation, GIServices are more sensitive to the location factor than general services. This paper proposes a location-aware GIServices quality prediction model via collaborative filtering (LAGCF). The model uses a mixed CF method based on time zone feature from the perspectives of both user and GIServices. Time zone is taken as the location factor and mapped into the prediction process. A time zone-adjusted Pearson correlation coefficient algorithm was designed to measure the similarity between the GIServices and the target, helping to identify highly similar GIServices. By adopting a coefficient of confidence in the final generation phase, the value of the QoGIS most similar to the target services will play a dominant role in the comprehensive result. Two series of experiments on large-scale QoGIS data were implemented to verify the effectivity of LAGCF. The results showed that LAGCF can improve the accuracy of QoGIS prediction significantly.     

基于镜像图的LRC和CRC偏差结合的人脸识别

为了提高人脸识别率及更好地显示人脸特征,本文提出了一种基于镜像图的LRC和CRC偏差结合的人脸识别方法.该方法首先生成一种镜像人脸,再通过融合原始人脸和镜像人脸形成新的混合训练样本,最后利用LRC和CRC偏差结合进行人脸识别.新方法增加了训练样本的数目,克服了由于光照和姿态等外部因素带来的影响.实验结果表明,镜像图与LRC和CRC偏差结合的人脸识别方法提高了人脸识别的准确性.