基于多媒体数据挖掘的多通道检索技术

首先介绍多媒体数据挖掘的过程,接着分析了多媒体信息的多通道检索的体系结构和多通道检索流程图。针对多媒体信息内容的复杂性,文章的第四部分介绍了多媒体关联规则挖掘算法,对将其应用于多通道检索进行了初步探讨。     

含椭球纳米颗粒复合介质的等效介电常数

利用S参数反演与MG(Maxwell-Garnett)有效介质理论计算了含椭球纳米颗粒复合介质的等效介电常数,考虑椭球体积分数和长宽比的影响,分析了两种等效模型的适用性。结果发现S参数反演对掺杂颗粒的形状和体积分数变化适应性较好,在所考虑的体积分数和长宽比下都能完美适用;而MG有效介质理论受体积分数和长宽比的影响较大,当椭球的长宽比为2、3或4时,其适用的最高体积分数分别为8%、4%或2%,因此随着椭球逐渐变扁,MG有效介质理论的适用范围会不断降低。      

知识管理综述

随着知识经济的发展,知识管理作为管理科学和信息科学交叉研究领域引起越来越多的关注.在对知识管理与知识工程,以及知识管理与信息管理等相关概念进行阐述的基础上,描述了知识管理的实施现状及其存在的问题,并从信息处理技术角度对知识采集、知识表示和知识应用等知识管理的三大要素以及制造业企业实施知识管理的关键技术进行了论述,最后对知识管理相关技术的研究方向进行了展望.     

A study of people's sketching habits in GIS

Sketching is traditionally associated withdoodling simple strokes on a piece of paper.Only few professionals outside of design andthe fine arts have recognized the expressivepower of this intuitive modality. However,sketching seems particularly well suited tocapture objects and situations in a spatialenvironment, such as geographic space. To learnmore about the techniques and strategies peopleuse when sketching, a survey of sketching wasconducted. The study showed that paper andpencil sketches contain mostly simple andabstract objects that are composed of only fewstrokes. The spatial configuration of a sceneis primarily expressed through the topologicalordering of objects relative to each other.Metric relationships are used to refine spatialconfigurations. These and other findingssuggest that sketching is an appropriatemodality to interact with a computer where onewants to describe and capture objectconfigurations in a spatial environment, suchas a geographic information system (GIS).     

Validation of the operational IASI level 2 processor using AIRS and ECMWF data

The algorithms being implemented in EUMETSAT’s IASI Level 2 Product Processing Facility are validated with real case situations using AIRS data and comparing the retrieved atmospheric states with ECMWF analyses. The tests have been performed for clear-sky ocean scenes during daytime.

The Empirical Orthogonal Function (EOF) retrievals show very good performance, with retrieved atmospheric states standard deviations between 1 and 2 K in temperature and 10% and 20% in relative humidity when compared with ECMWF analysis in the troposphere. The EOF retrievals show relatively smooth profiles.

Results from an iterative retrieval show a standard deviation between 2 and 3 K in temperature and 10% and 30% in relative humidity when compared with ECMWF analyses in the troposphere. They tend to show meteorologically reasonable discontinuities in both temperature and relative humidity. This seems to be the reason why they do not compare as well with ECMWF analyses as the EOF retrievals do. Whether they are closer to reality or not will have to be tested with co-located radiosondes or similar more accurate data, which generally do not exhibit such smooth vertical profiles as ECMWF analyses do.     

浅析Z39．50服务器的实现

对在TCP／IP协议上实现Z39．50服务器所涉及到的主要问题进行了研究给出了一个相应的解决方案，并介绍了自行开发的Z39．50服务器软件。     

第四代语言NH4GL系统

本文介绍了第四代语言系统NH4GL,并论述了其设计准则和实现方案。     

基于主题模型的结构化Web服务发现机制

提出了基于主题模型(topic model)的结构化Web服务发现机制.利用LDA(Latent Dirichlet Allocation)生成概率模型,将Web服务(Web service)建模为结构化文本文档.一个文档视作主题的概率分布,主题又由关键词的概率分布组成,从而提供基于主题的Web服务检索.同时,利用Web服务的结构化特性,将Web服务描述文档表示为有向无环图,利用n阶谱核测量Web服务文档的相似度,实现Web服务结构化信息的发现.通过实验分析对比,基于主题模型的结构化Web服务发现机制有效提高了Web服务发现的效率和精确率.      

基于边缘检测与颜色目标定位的图像检索

提出一种先利用图像边缘信息缩小检索范围。再利用图像颜色信息进行目标定位的图像检索算法。首先。提取图像边缘信息。利用图像位错率进行边缘信息比较,位错率越小图像边缘信息越接近;然后,利用主色调确定图像的目标块,进行目标子块间的比较。算法忽略图像中不重要的背景因素,有效利用重要的目标因素。从而提高了检索效率。仿真实验证明该算法比单一使用边缘检测、颜色目标定位具有更好的检索性能。     

面向中文问答的信息检索系统及评测

为了解决中文问答系统中检索有效性的问题,提出并构建了一个面向中文问答的信息检索系统,在新进展的基础上,该系统通过利用问答系统中问题分类信息,对查询进行优化处理,从而改进问答系统中检索结果的质量,在独立的检索评测中正确率达到0.5013,在问答系统的整体评测中F3值达到0.2231,取得了较好的效果.