• Maxillofacial Plastic and Reconstructive Surgery
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• v.23 no.3
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• pp.238-243
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• 2001

Purpose : The purpose of this study was to determine radiologic variables affecting extraction of impacted mandibular third molar. Materials and Methods : This study was investigated on 44 consecutive extractions of unilateral impacted mandibular third molars (Male;34, Female;10, Mean age;24.98, Age range;19-35). Fourteen radiologic variables, which were actual value except only one, were evaluated to establish their relation to the operation time. The Pearson correlation coefficient and Stepwise procedures for regression analysis were carried out. Results : Eight variables (depth, angulation, ramus width, relationship to the second molar, distal ramus depth, mesial ramus depth, mesial periodontal ligament width and follicle) showed a statistically significant relation to the operation time(Pearson correlation coefficient, p<0.05). Two variables, depth and mesial periodontal ligament width, showed the most powerful and just relation to the operation time($r^2$ = 0.349, p<0.05). Conclusion : This study shows that our results can help general practioner to estimate the operation time of extraction of impacted mandibular third molars by measuring two radiologic variables ; depth and mesial periondontal ligament width.

• Annual Conference on Human and Language Technology
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• 2018.10a
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• pp.552-556
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• 2018

본 논문에서는 텍스트에서 개체(entity) 간 관계(relation) 추출 문제에서 의존구문트리를 이용하여 자질을 추출할 때 형용사구 내에 관계가 나타나는 경우의 성능을 향상시키는 방법을 제안한다. 일률적으로 의존구문트리의 최소공동조상(LCA: Least Common Ancestor)을 이용하는 일반적인 방법보다 형용사구가 나타날 때는 형용사구의 술어를 대신 이용하는 것이 더 좋은 자질이 된다는 것을 제안하고 로지스틱 회귀분석, SVM(linear), SVM(exponential kernel)을 이용한 실험들을 통해 그 효과를 확인하였다. 이는 트리커널을 이용한 것과 같이 의존구문트리의 최소공동조상이 주요한 역할을 하는 관계추출 모델들의 성능을 높일 수 있음을 보여 준다. 수행한 실험 과정을 통해 관계추출 데이터 셋에서 형용사구 내 관계를 포함하는 문장이 전체에서 차지하는 비율이 낮을 경우 생길 수 있는 문제를 추가적으로 얻을 수 있었다.

• Resources Recycling
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• v.27 no.4
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• pp.65-69
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• 2018

In solvent extraction, extraction isotherm represents the relation between the equilibrium concentration of metal in the aqueous and organic phase. McCabe-Thiele diagram on which extraction isotherm and operating line are constructed provides valuable information on the mass transfer operation. When the equilibrium constant of a solvent extraction reaction is known, the calculation method to obtain extraction isotherm was introduced. Kresmer equation by which the number of extraction stages can be calculated when the distribution coefficient is constant was introduced.

• The Journal of the Korea Contents Association
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• v.12 no.7
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• pp.463-472
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• 2012

For last decade, the amount of information has been increased rapidly because of the internet and computing technology development, mobile devices and sensors, and social networks like facebook or twitter. People who want to gain important knowledge from database have been frustrated with large database. Many studies for automatic knowledge extracting meaningful knowledge from large database have been fulfilled. In that sense, automatic knowledge extracting with computing technology has been highly significant in information technology field, but still has many challenges to go further. In order to improve the effectives and efficiency of knowledge extracting system, test collection is strongly necessary. In this research, we introduce a test collection for automatic knwoledge extracting. We name the test collection KEEC/KREC(KISTI Entity Extraction Collection/KISTI Relation Extraction Collection) and present the process and guideline for building as well as the features of. The main feature is to tag by experts to guarantee the quality of collection. The experts read documents and tag entities and relation between entities with a tool for tagging. KEEC/KREC is being used for a research to evaluate system performance and will continue to contribute to next researches.

• Proceedings of the Korea Contents Association Conference
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• 2009.05a
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• pp.754-758
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• 2009

Extracting information in large-scale documents would be very useful not only for information retrieval but also for question answering and summarization. Even though relation extraction is very important area, it is difficult to develop and evaluate a machine learning based system without test collection. The study shows how to build test collection(KREC2008) for the relation extraction system. We extracted technology terms from abstracts of journals and selected several relation candidates between them using Wordnet. Judges who were well trained in evaluation process assigned a relation from candidates. The process provides the method with which even non-experts are able to build test collection easily. KREC2008 are open to the public for researchers and developers and will be utilized for development and evaluation of relation extraction system.

• Journal of Information Science Theory and Practice
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• v.2 no.1
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• pp.6-21
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• 2014

This paper proposes a novel knowledge extraction system, TAKES (Two-step Approach for Knowledge Extraction System), which integrates advanced techniques from Information Retrieval (IR), Information Extraction (IE), and Natural Language Processing (NLP). In particular, TAKES adopts a novel keyphrase extraction-based query expansion technique to collect promising documents. It also uses a Conditional Random Field-based machine learning technique to extract important biological entities and relations. TAKES is applied to biological knowledge extraction, particularly retrieving promising documents that contain Protein-Protein Interaction (PPI) and extracting PPI pairs. TAKES consists of two major components: DocSpotter, which is used to query and retrieve promising documents for extraction, and a Conditional Random Field (CRF)-based entity extraction component known as FCRF. The present paper investigated research problems addressing the issues with a knowledge extraction system and conducted a series of experiments to test our hypotheses. The findings from the experiments are as follows: First, the author verified, using three different test collections to measure the performance of our query expansion technique, that DocSpotter is robust and highly accurate when compared to Okapi BM25 and SLIPPER. Second, the author verified that our relation extraction algorithm, FCRF, is highly accurate in terms of F-Measure compared to four other competitive extraction algorithms: Support Vector Machine, Maximum Entropy, Single POS HMM, and Rapier.

• Journal of information and communication convergence engineering
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• v.20 no.2
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• pp.113-124
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• 2022

News in the form of web data generates increasingly large amounts of information as unstructured text. The capability of understanding the meaning of news is limited to humans; thus, it causes information overload. This hinders the effective use of embedded knowledge in such texts. Therefore, Automatic Knowledge Extraction (AKE) has now become an integral part of Semantic web and Natural Language Processing (NLP). Although recent literature shows that AKE has progressed, the results are still behind the expectations. This study proposes a method to auto-extract surface knowledge from English news into a machine-interpretable semantic format (triple). The proposed technique was designed using the grammatical structure of the sentence, and 11 original rules were discovered. The initial experiment extracted triples from the Sri Lankan news corpus, of which 83.5% were meaningful. The experiment was extended to the British Broadcasting Corporation (BBC) news dataset to prove its generic nature. This demonstrated a higher meaningful triple extraction rate of 92.6%. These results were validated using the inter-rater agreement method, which guaranteed the high reliability.

• Journal of KIISE
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• v.42 no.12
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• pp.1568-1574
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• 2015

Relation extraction plays a role in for the process of transforming a sentence into a form of knowledge base. In this paper, we focus on predicates in a sentence and aim to identify the relevant knowledge base properties required to elucidate the relationship between entities, which enables a computer to understand the meaning of a sentence more clearly. Distant Supervision is a well-known approach for relation extraction, and it performs lexicalization tasks for knowledge base properties by generating a large amount of labeled data automatically. In other words, the predicate in a sentence will be linked or mapped to the possible properties which are defined by some ontologies in the knowledge base. This lexical and ontological linking of information provides us with a way of generating structured information and a basis for enrichment of the knowledge base.

• Natural Product Sciences
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• v.28 no.2
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• pp.89-92
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• 2022

In Asia, the roots of Paeonia lactiflora and Astragalus membranaceus have been used as therapeutic agents for thousands of years. Once the medicinal plants are harvested, they are dried and their ingredients are extracted by heat-mediated reflux extraction. However, the condensed structure of organic products (especially roots) limits the extraction of bioactive components. In this study, we assessed the effect of the puffing method (using high temperature and pressure) before the extraction process in relation to the profile and antioxidant capacity of active ingredients. We demonstrated that the additional puffing process before extraction methods improves the yield of polyphenol concentrations and antioxidant activities from the roots of P. lactiflora and A. membranaceus.

• The KIPS Transactions:PartB
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• v.12B no.4 s.100
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• pp.479-486
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• 2005

The ontology was proposed to construct the logical basis of semantic web. Ontology represents domain knowledge in the formal form and it enables that machine understand domain knowledge and provide appropriate intelligent service for user request. However, the construction and the maintenance of ontology requires large amount of cost and human efforts. This paper proposes an automatic ontology construction method for defining relation between concepts in the documents. The Proposed method works as following steps. First we find concept pairs which compose association rule based on the concepts in domain specific documents. Next, we find pattern that describes the relation between concepts by clustering the context between two concepts composing association rule. Last, find generalized pattern name by clustering the clustered patterns. To verify the proposed method, we extract relation between concepts and evaluate the result using documents set provide by TREC(Text Retrieval Conference). The result shows that proposed method cant provide useful information that describes relation between concepts.