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1.
为了更好地满足词典使用者的多方面需求,词典家们已经开始把重点转移到使用者的需求和查询技能的研究上来。也就是,词典学从过去对词进行详尽描写,转向于词典使用研究,并从词典使用过程和使用者的角度反思词典编纂问题。就精心选择各种信息,并以最优的方式呈现给用户来言,编者应该对使用者进行充分的调查了解之后再做出抉择。这样,词典才更具针对性,才能更好地满足使用者的查询需求。历年词典使用研究中采用的一些方法各具优缺点,而计算机技术在此方向具有独特优势,研究人员应开发先进的计算机软件来辅助词典使用研究。  相似文献   

2.
地名词典查询是地名校正、地名匹配等地名服务应用的重要基础,但是地名数量的快速增长使得词典查询性能面临严峻挑战。针对大规模数据环境中传统词典查询方法准确率不高且效率较低等问题,提出了一种顾及字符特征的中文地名词典查询方法(CGQM)。首先,查询具有相同字符特征的地名形成候选地名集合,同时构建单字索引提升查询效率;其次,依据字符数量特征比较查询地名与候选地名的差异,进一步过滤候选地名集合;最后,基于字符位置特征优化查询结果排序策略,使得结果排序更为合理。实验以全国地名词典为例,构建5组测试集进行CGQM方法与Lucene检索方法的对比分析。研究结果表明,CGQM方法对于增强地名词典查询功能、提升查询效率具有实际意义。  相似文献   

3.
从软件工程学的角度出发,详细地分析了干部信息管理系统的需求并进行了设计;着重阐述了该系统的数据流图、数据词典以及系统的模块结构图  相似文献   

4.
空间方向关系作为空间查询的重要选取条件,在地理信息系统等许多领域得到了广泛的应用。本文利用锥形模型和四叉树索引提出一种基于方向关系的空间查询算法,并在其基础上结合空间距离关系,实现了基于方向和距离关系的复合空间查询。实验表明,提出的算法能够对不同几何类型的空间数据进行准确、高效的查询,较好地满足了实际应用的需求。  相似文献   

5.
国土资源信息标准参考模型   总被引:8,自引:2,他引:6  
为更好地满足全社会对国土资源信息共享的越来越迫切的需求,为使其标准化的工作在统一的框架下进行,采用协调一致的方法实现整体效益最佳,我们借鉴国际信息标准的思路,以在更大的范围内实现信息的集成与共享为目标,研究并提出了国土资源信息标准化的技术框架-国土资源信息标准参考模型(以下简称参考模型)。该模型阐述国土资源信息标准化的对象、总体需求、涉及的概念、标准的构成框架与相互关系、标准制定与使用的基本原则。本文重点阐述提出国土资源信息标准参考模型的背景、内容及要点。  相似文献   

6.
近年来,随着GPS技术的日趋成熟,各行各业使用GPS进行测量已经是常态化。人们对GPS的认知已经不满足于仅仅使用,对GPS信号误差的研究和试验,已经有了一定的成效,已经不满足于在局限的范围内进行测量,对于广域空间测量的开发和需求在不断地扩大,而SBAS系统的出现则解决了人们的这一需求。  相似文献   

7.
通过对比否定前缀不同的同义词在国内外词典中的收录情况和在剑桥科学文摘自然科学类文摘中的使用次数,并从词源学、形态学和语音学的角度进行分析,指出:国内英语科技词典中存在否定前缀不当的词条;否定前缀un-,尤其是non-被滥用。以英美词典为参照,发现国内英语科技词典中后缀-ce与-cy相混淆;后缀-ness被滥用。分析了否定前缀不同的同义词单元化的趋势。建议清理词缀“不当”的词条:删除否定前缀“不当”的词条,正确区分后缀不同的同根词在不同学科中的形式和词义。  相似文献   

8.
本文针对城市信息模型(City Information Modeling,CIM)快速构建与城市级海量三维数据渲染调度需求,深入研究了轻量化CIM构建核心技术环节,从CIM快速构建、模型轻量化和三维立体空间索引3方面提出了解决方案.最后以某地级市场景为例,对关键技术可行性及应用效果进行了验证.结果表明关键技术成果能够满足城市大批量三维模型快速建设以及地上地下一体化管理需求,提高了全空间模型渲染调度和查询分析效率,对于推动CIM平台建设有着重要的参考意义.  相似文献   

9.
现有的时空数据库能够支持对大规模移动对象数据的时空聚集查询。但移动对象数据量巨大,且目前多采用单线程进行查询计算,其查询速度无法满足应用需求。由于时空聚集查询具有良好的可并行性,提出了一种基于区域划分的多线程并行时空聚集查询方法。该方法在服务器端对时空域进行格网划分,形成多个时空立方体,采用多线程并行的技术方法在每个时空立方体上进行时空聚集查询,最后将查询结果整合。通过对真实数据集进行的实验分析,该方法在查询速度上有明显提升。  相似文献   

10.
空间数据访问集成与分布式空间数据源对象查询   总被引:1,自引:0,他引:1  
目前,针对空间数据库的访问与处理方法,无法满足分布式环境下异构数据源的服务化存取和面向空间数据源的对象查询处理需求。本文给出了数据网格环境下的分布式空间数据访问与查询的方法和实现,并在服务化查询处理过程中,嵌入符合SQL/MM查询规范的空间拓展函数,实现分布式空间数据对象查询和嵌入查询过程中的空间数据分析处理。在此基础上,给出空间数据对象查询树的构造过程,以及分布式空间查询工作流的执行流程。数据访问与集成策略在空间数据处理上的应用,对异构空间数据源协同处理等,涉及大规模空间数据存取访问的应用需求,有很好的理论和实际应用价值。  相似文献   

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12.
Based on the hydrographic data in austral summer during the 22nd Antarctic Expedition of China(2005/2006),some features can be found about the northern margin of Emery ice shelf as follows.The heat content in the surface layer(0-50 m) at the eastern end and the western end of the ice-shelf margin is much higher than that at the middle.The upper mixing-layer depth and the seasonal thermocline depth at the middle of the ice-shelf northern margin are much shallower than those at the both ends.However there is much less difference between the middle and the ends in the bottom layer.The remote sensing photos show that the inhomogeneity in the surface-layer water is closely related to the spatial distribution of the floes and polynia in the area.  相似文献   

13.
Phylogenetic analysis based on 16S rDNA of 8 strains of cultivable bacteria isolated from Arctic sea-ice was studied.The results showed that strain BJ1 belonged to genus Planococcus,which was a genus of low mole percent G C gram-positive bacteria;strain BJ6 belonged to genus Burkholderia of β-proteobacteria and the rest 6 strain all belonged to γ-proteobacteria,of which strain BJ8 was a species of Pseudoalteromonas,strain BJ2-BJ5 and BJ7 were members of genus Psychrobacter.Phylogenetic analysis also indicated that bacteria of genus Psychrobacter of the isolates formed a relatively independent phylogenetic cluster in comparison with other bacteria belonged to genus Psychrobacter.  相似文献   

14.
正1 Aims and Scope Advances in Polar Science(APS)is an international,peer-reviewed journal jointly sponsored by the Polar Research Institute of China and the Chinese Arctic and Antarctic Administration.APS is a comprchensive academic journal dedicated to presentation of multi-disciplinary achievements in Arctic and Antarctic expeditions and research.Its primary purpose is to publish achievements in fundamental research,applied  相似文献   

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16.
《山地科学学报》2014,(4):I0004-I0009
<正>AIMS AND SCOPE(Editorial Policy)The Journal of Mountain Science(JMS)is devoted to mountains and their surrounding lowlands-ecoregions of particular global importance,with a particular emphasis on the important highlands/mountains in the world,such as the Tibetan Plateau,the Himalayas,the Alps,the Andes,the Rockies and many other mountain ranges of our planet.  相似文献   

17.
<正>The Journal of Mountain Science(JMS),founded in2004,is an international English-language journal on mountain sciences.JMS is supervised by the Chinese Academy of Sciences(CAS),sponsored by the Chengdu Institute of Mountain Hazards and Environment,CAS,published by Science Press China,and distributed by Springer exclusively throughout the world(excluding Mainland China).The JMS is published bimonthly,fulltexted in SpringerLink and CNKI,indexed/abstracted by  相似文献   

18.
Using the NCEP/NCAR reanalysis monthly 500 hPa height data on a 2.5 latitude-longitude grid and 1°×1° sea ice data,the polar vortex area,intensity index and arctic sea ice area index are calculated respectively,and the meridional distribution,period variation and the abrupts in the long range trend are analyzed to study their relationship.The results show that the meridional distribution of sea ice and polar vortex h-ave distinctive difference,the relative positions of them are different in the eastern and western hemispheres,and exept they have periods of 4 months,quasi half year,quasi year,4-5 years and 10 years commonly,and each of them has its own respective variation as well.The sea ice area is decreasing apparently since 1980's,so is the polar vortex area,but their abrupt changge time are different totally.The area of sea ice and polar vortex has prominent positive correlation,but the relationship of sea ice intensity,polar vortex intensity,polar vortex area is complicated.  相似文献   

19.
The ability of cell to modulate the fluidity of plasma membrane was crucial to the survival of microorganism at low temperature. Plasma membrane proteins, fatty acids and carotenoids profiles of Antarctic psychrophilc yeast Rhodotorula sp. NJ298 were investigated at -3 ℃, 0 ℃ and 8 ℃. The results showed that plasma membrane protein content was greater at -3 ℃ than that at 8 ℃, and a unique membrane polypeptide composition with an apparent molecular mass of 94.7 kDa was newly synthesized with SDS-PAGE analysis; GC analysis showed that the main changes of fatty acids were the percentage of unsaturated fatty acids (C18∶ 1 and C18∶ 2) and shorter chain saturated fatty acid (C10∶ 0) increased along with the decrease of the culture temperature from 8 ℃ to -3 ℃; HPLC analysis indicated that astaxanthin was the major functional carotenoids of the plasma membrane, percentage of which increased from 54.6±1.5% at 8 ℃ to 81.9±2.1% at -3 ℃. However the fluidity of plasma membrane which was determined by measuring fluorescence anisotropy was similar at -3 ℃, 0 ℃ and 8 ℃. Hence these changes in plasma membrane's characteristics were involved in the cellular cold-adaptation by which NJ298 could maintain normal plasma membrane fluidity at near-freezing temperature.  相似文献   

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