Unlike informationRetrieval, information Extraction Systems extract factual information directly from natural language texts.
与信息检索不同，信息抽取直接从自然语言文本中抽取事实信息。
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This paper gives a brief introduction to the concept and technologies of multimedia informationretrieval, and further analyzes several typical systems of multimedia informationretrieval.
简明地介绍了多媒体信息检索的概念及其主要技术，并对几个典型多媒体信息检索系统进行了探讨分析。
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Data standards, metadata, document codes, subject indexes and filing systems are widely used to enable efficient information correlation, storage and retrieval.