• Title, Summary, Keyword: TFIDF

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Design of Keyword Extraction System Using TFIDF (TFIDF를 이용한 키워드 추출 시스템 설계)

  • 이말례;배환국
    • Korean Journal of Cognitive Science
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    • v.13 no.1
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    • pp.1-11
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    • 2002
  • In this paper, a test was performed to determine whether words in Anchor Text were appropriate as key words. As a result of the test. there were proper words of high weighting factor, while some others did not even appear in the text. therefore, were not appropriate as key words. In order to resolve this problem. a new method was proposed to extract key words. Using the proposed method, inappropriate key words can be removed so that new key words be set, and then, ranking becomes possible with the TFIDF value as a weighting factor of the key word. It was verified that the new method has higher accuracy compared to the previous methods.

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A Hangul Document Classification System using Case-based Reasoning (사례기반 추론을 이용한 한글 문서분류 시스템)

  • Lee, Jae-Sik;Lee, Jong-Woon
    • Asia pacific journal of information systems
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    • v.12 no.2
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    • pp.179-195
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    • 2002
  • In this research, we developed an efficient Hangul document classification system for text mining. We mean 'efficient' by maintaining an acceptable classification performance while taking shorter computing time. In our system, given a query document, k documents are first retrieved from the document case base using the k-nearest neighbor technique, which is the main algorithm of case-based reasoning. Then, TFIDF method, which is the traditional vector model in information retrieval technique, is applied to the query document and the k retrieved documents to classify the query document. We call this procedure 'CB_TFIDF' method. The result of our research showed that the classification accuracy of CB_TFIDF was similar to that of traditional TFIDF method. However, the average time for classifying one document decreased remarkably.

Unspecified Event Detection System Based on Contextual Location Name on Twitter (트위터에서 문맥상 지역명을 기반으로 한 불특정 이벤트 탐지 시스템)

  • Oh, Pyeonghwa;Yim, Junyeob;Yoon, Jinyoung;Hwang, Byung-Yeon
    • KIPS Transactions on Software and Data Engineering
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    • v.3 no.9
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    • pp.341-348
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    • 2014
  • The advance in web accessibility with dissemination of smart phones gives rise to rapid increment of users on social network platforms. Many research projects are in progress to detect events using Twitter because it has a powerful influence on the dissemination of information with its open networks, and it is the representative service which generates more than 500 million Tweets a day in average; however, existing studies to detect events has been used TFIDF algorithm without any consideration of the various conditions of tweets. In addition, some of them detected predefined events. In this paper, we propose the RTFIDF VT algorithm which is a modified algorithm of TFIDF by reflecting features of Twitter. We also verified the optimal section of TF and DF for detecting events through the experiment. Finally, we suggest a system that extracts result-sets of places and related keywords at the given specific time using the RTFIDF VT algorithm and validated section of TF and DF.

Automatic Text Categorization using difference TTF and ITTF (TTF와 ITTF의 차를 이용한 자동 문서 분류)

  • 이상철;하진영
    • Proceedings of the Korean Information Science Society Conference
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    • pp.133-135
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    • 2001
  • 본 논문에서는 일반적으로 Word Based Matching 방법에서 많이 쓰이는 TFIDF 방법대신에 TTF(Total Term Frequency)와 ITTF(Inverse Total Term Frequecy) 에 가중치를 주어 문서분류의 정확도를 높이는 방법을 제안하고자 한다. TFIDF방법에서 IDF는 역문헌빈도를 나타내는데 Term에 대한 빈도비율의 공정성이 떨어져 문서 분류의 정확도에 한계가 있다. 본 논문에서 제시하는 문서 분류방법은 TTF와 ITTF에 각각의 가중치를 준 후에 차연산 이용하여 문서를 분류하는 것이다. 이러한 방법의 특징은 IDF를 사용할 때 보다 각 카테고리에 있는 term, 즉 단어의 중요도에 대한 가중치를 좀 더 공평하게 줌으로써 문서의 분류를 높일 수 있다. 본 논문에서는 조선일보의 카테고리를 사용하였으며 조선일보의 기사를 대상으로 문서 자동 분류 실험을 수행하였다. 실험 결과 TFIDF보다 본 논문에서 제안한 방법이 문서 분류에 높은 정확도를 나타냄을 보였다.

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A Sliding Window-based Multivariate Stream Data Classification (슬라이딩 윈도우 기반 다변량 스트림 데이타 분류 기법)

  • Seo, Sung-Bo;Kang, Jae-Woo;Nam, Kwang-Woo;Ryu, Keun-Ho
    • Journal of KIISE:Databases
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    • v.33 no.2
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    • pp.163-174
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    • 2006
  • In distributed wireless sensor network, it is difficult to transmit and analyze the entire stream data depending on limited networks, power and processor. Therefore it is suitable to use alternative stream data processing after classifying the continuous stream data. We propose a classification framework for continuous multivariate stream data. The proposed approach works in two steps. In the preprocessing step, it takes input as a sliding window of multivariate stream data and discretizes the data in the window into a string of symbols that characterize the signal changes. In the classification step, it uses a standard text classification algorithm to classify the discretized data in the window. We evaluated both supervised and unsupervised classification algorithms. For supervised, we tested Bayesian classifier and SVM, and for unsupervised, we tested Jaccard, TFIDF Jaro and Jaro Winkler. In our experiments, SVM and TFIDF outperformed other classification methods. In particular, we observed that classification accuracy is improved when the correlation of attributes is also considered along with the n-gram tokens of symbols.

A Study on the Development of Search Algorithm for Identifying the Similar and Redundant Research (유사과제파악을 위한 검색 알고리즘의 개발에 관한 연구)

  • Park, Dong-Jin;Choi, Ki-Seok;Lee, Myung-Sun;Lee, Sang-Tae
    • The Journal of the Korea Contents Association
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    • v.9 no.11
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    • pp.54-62
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    • 2009
  • To avoid the redundant investment on the project selection process, it is necessary to check whether the submitted research topics have been proposed or carried out at other institutions before. This is possible through the search engines adopted by the keyword matching algorithm which is based on boolean techniques in national-sized research results database. Even though the accuracy and speed of information retrieval have been improved, they still have fundamental limits caused by keyword matching. This paper examines implemented TFIDF-based algorithm, and shows an experiment in search engine to retrieve and give the order of priority for similar and redundant documents compared with research proposals, In addition to generic TFIDF algorithm, feature weighting and K-Nearest Neighbors classification methods are implemented in this algorithm. The documents are extracted from NDSL(National Digital Science Library) web directory service to test the algorithm.

Implement of Relevance Feedback in "MIRINE" Information Retrieval System ("미리내" 정보검색 시스템에서 Relevance Feedback 구현)

  • Park, Su-Hyun;Park, Se-Jin;Kwon, Hyuk-Chul
    • Annual Conference on Human and Language Technology
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    • pp.65-71
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    • 1997
  • 이 논문은 부산대학교 전자계산학과 인공지능 연구실에서 개발한 정보검색 시스템 "미리내"의 적합성 피드백 방법을 분석하고, 그 방법들의 검색 효율을 비교 분석하였다. "미리내"에서 질의문은 자연언어 질의문을 사용하고 재검색을 위한 적합성 피드백은 원질의문에서 검색된 문서 중 이용자가 직접 선택한 적합 문서에서 추출한다. 적합성 피드백은 크게 단어 확장(Term Expansion)을 위한 단어 선택 방법과 추가될 단어에 가중치를 부여하는 단어 가중치 부여(Term Weighting)의 2가지 요소로 이루어진다. 단어 선택을 위해서는 적합 문서에 나타난 단어 빈도합(tf), 역문헌빈도(idf), 적합 문서 중에서 해당 단어가 있는 적합 문서의 비율(r/R) 등의 정보를 이용한다. 단어 가중치 부여 방법으로는 정규화 또는 코사인 함수를 이용하여 부여하였다. 단어확장에는 tfidf가 tfidf(r/R)보다 정확도 면에서 나은 향상율을 보였으나, 30위 내 검색된 적합문서의 수를 비교해 보았을 때 tfidf(r/R)의 정확도가 높았다. 단어 선택 방법에서 계산된 값을 정규화하여 가중치를 부여하였을 때 보다 코사인 함수를 이용하여 가중치를 부여하였을 때 정확도가 높았다. 실험은 KT-Set 2.0 (4391 건), 동아일보 96 년 신문기사(70459 건)를 대상으로 수행하였다.

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User Profile Generation using Visual Differences of HTML Document (HTML 문서의 시각적 분석을 이용한 사용자 프로파일 생성)

  • Gwak, Ju-Hyeon;Lee, Chang-Hun
    • The Transactions of the Korea Information Processing Society
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    • v.7 no.6
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    • pp.1827-1833
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    • 2000
  • In this study, I've suggested how to improve the function of web-agents to find out the web-document users prefer. Web-agents employ TFIDF, which considers all the worked used in a document as equal in improtance to find out users' preferences. Web-documents like HTML, however, make visual differences by using different sizes of letters and highlighting them based on importance of words. In this study, I've attempted to improve the functions of the web-agents by differentiating the weight of each worked in accordance with the visual importance of each paragraph. To enhance functions, I've suggested how to make a profile from each paragraph to be consolidated later. As to suggested algorithms, I've tested their effects by comparing the established TFIDF algorithm with the function which helps users find documents they prefer.

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Automatic Classification of Web Documents Using Concept-Based Keyword Information (개념 기반 키워드 정보를 이용한 웹 문서의 자동 분류)

  • 박사준;김기태
    • Proceedings of the Korean Information Science Society Conference
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    • pp.151-153
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    • 2003
  • 본 연구에서는 웹 문서를 분류하기 위해서 분류하고자 하는 영역(category)에 대한 개념 지식을 이용한다. 먼저, 영역별 개념 지식을 기구축된 웹 문서의 집합으로부터 제목과 하이퍼링크에 기반한 앵커 텍스트를 이용하여 개념을 보유한 키워드를 추출한다. 추출된 키워드를 형태소 분석을 통해 색인어로 추출한다. 추출된 색인어에 대해 TFIDF를 확장한 영역 적용 색인 가중치 TFIDFc를 적용하여 영역별 개념 기반 색인어와 색인를 구축한다. 색인은 TFIDF를 영역별로 확장하여 구축한다. 구축된 영역별 개념 기반 색인을 이용하여 새로운 웹 문서에 대해서 어떤 영역에 해당하는 가를 결정하는 자동 분류 알고리즘을 수행한다. 자동 분류 알고리즘에 의해 수행된 문서는 영역별로 정리되며, 또한, 분류된 웹 문서의 색인어는 새로운 개념 기반 키워드로 추출되어 개념 기반 영역 지식을 구축한다.

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Document Retrieval using Concept Network (개념 네트워크를 이용한 정보 검색 방법)

  • Hur, Won-Chang;Lee, Sang-Jin
    • Asia pacific journal of information systems
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    • v.16 no.4
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    • pp.203-215
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    • 2006
  • The advent of KM(knowledge management) concept have led many organizations to seek an effective way to make use of their knowledge. But the absence of right tools for systematic handling of unstructured information makes it difficult to automatically retrieve and share relevant information that exactly meet user's needs. we propose a systematic method to enable content-based information retrieval from corpus of unstructured documents. In our method, a document is represented by using several key terms which are automatically selected based on their quantitative relevancy to the document. Basically, the relevancy is calculated by using a traditional TFIDF measure that are widely accepted in the related research, but to improve effectiveness of the measure, we exploited 'concept network' that represents term-term relationships. In particular, in constructing the concept network, we have also considered relative position of terms occurring in a document. A prototype system for experiment has been implemented. The experiment result shows that our approach can have higher performance over the conventional TFIDF method.