• The Journal of Information Technology and Database
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• v.3 no.1
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• pp.25-43
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• 1996

정보시스템이 효과적이기 위해서는 정보가 도출되는 자료의 무결성이 우선 전제되어야 한다. 특히 오늘날과 같이 사회가 다양한 활동들을 지원하기 위해 컴퓨터를 이용한 정보시스템에 점점 더 의존해감에 따라 정보시스템에서 사용되는 자료의 질을 적절한 수준으로 유지 및 관리해야 할 필요성이 더욱 절실히 대두되게 되었다. 그럼에도 불구하고 여전히 관리자들은 효과적인 의사결정 및 활동을 위해 필요한 최신의 정확한 자료들을 제공 받지 못하고 있으며 [Nesbit 1985], 정보시스템이 기대 이하의 성능을 나타내는 가장 단순하고 일반적인 원인은 정보시스템에 입력된 자료가 부정확하거나 불완전하기 때문인 것으로 나타나고 있다 [Ballou and Pazer 1989]. 낮은 질의 자료는 즉각적인 경제적 손실뿐만 아니라 보다 많은 간접적이고 경제적으로 측정하기 어려운 손실들을 초래한다. 그리고 아무리 잘 관리되는 시스템에도 시간이 흐름에 따라 여러가지 원인에 의해 저장된 자료에 오류가 발생하게 된다. 자료의 질을 적절한 수준으로 유지하기 위해서는 이와 같은 오류는 주기적으로 발견 및 수정되어야 한다. 이와 같은 작업을 데이타베이스 감사라고 한다. 본 논문에서는 데이타베이스에 저장된 자료의 질을 주기적으로 향상시키기 위한 최적 데이타베이스 감사시점을 일반적인 비용모형을 통해 결정하는 과정을 제시하고, 그와 관련된 사항들에 대해 논의하였다. 데이타베이스는 오류 발생률도 다르고 오류의 결과도 상당히 다른 여러개의 자료군들로 구성되어 있다고 가정하였다. 그리고 각 자료군에서의 오류 누적과정은 확정적이 아닌 확률적인 과정으로 모형화하고, 단순한 오류의 발생뿐만 아니라 오류의 크기도 확률적으로 변하는 상황을 모형에 반영하여 보다 현실성있게 모형화하였다.

• Proceedings of the Korean Information Science Society Conference
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• 2006.06a
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• pp.13-15
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• 2006

microRNA는 유전자의 전사 후 과정에서 negative regulation을 담당하는 small noncoding RNA의 한 증류이다. 최근까지 330여개의 인간 microRNA가 발견되었지만 그들의 기능이 밝혀진 것은 소수에 불과하다. microRNA의 기능은 3'UTR에 불완전 상보결합을 통해 negative regulation을 받게 되는 유전자의 기능으로부터 유추되는 것이 일반적이다. 특별히 유전체상에 군집화 된 microRNA들은 하나의 전사체로부터 발현되는 것으로 판단되며, 같은 또는 관련된 기능을 하거나 같은 목표 유전자를 조절하기 위한 functional family일 가능성이 높다. 또한 이러한 functional family는 하나의 전사체로부터 발현되기 때문에, 조직별로 조건별로 같은 발현 패턴을 보여야 한다. 본 연구에서는 발현데이터로부터 microRNA functional family를 탐색하기 위해, 5개의 연구 그룹에서 공개한 조직별 microRNA 발현데이터를 표준화 작업을 거친 후 통합하고 k-nearest neighbor 알고리즘을 이용해 결측치를 보정한 후 microRNA 발현사이의 correlation을 계산한다. 이때 데이터 통합에서 생기는 문제에 robust한 결과를 얻기 위해 실제 발현데이터가 아닌 rank 데이터부터 correlation을 측정한다. 계산된 spearman ranked correlation 결과와 microRNA의 genomic coordination 정보로부터 34개의 functional family를 정의할 수 있었다.

• Microbiology and Biotechnology Letters
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• v.21 no.1
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• pp.47-53
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• 1993

Antibiotics KG-431A and KG-431B were isolated from the fermentation broth of the Clostridium sp. KH-431. As we have shown previously, only KG-431B was successful to recrystallize. These antibiotics showed antimicrobial activities against broad spectrum of bacteria and fungi. KG-431B also showed anticancer activity against some animal tumor cells according to the SRB method. Physico-chemical properties of KG-431B were determined using UV, IR, NMR and Mass spectra. It was identified to be 3-Indole propionic acid and the structure of the KG-431A is currently under investigation.

• Korean Journal of Microbiology
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• v.53 no.4
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• pp.326-328
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• 2017

Herbaspirillum sp. meg3 belonging to Betaproteobacteria was isolated from soil in Jeju island. Here, we report the complete genome sequence of strain meg3 with a size of approximately 5.47 Mb and a mean G + C content of 57.1%. The genome included 4,816 coding sequences, and 9 ribosomal RNA and 51 transfer RNA genes. In the genome, two incomplete prophage regions have been identified. Also, we propose that strain meg3 has a potential capability for aromatic-compounds degradation based on the result of genome analysis.

• Journal of the Korean Arthroscopy Society
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• v.6 no.2
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• pp.126-130
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• 2002

Purpose : To evaluate the diagnostic efficiency of the subacromial bursoscopy with glenohumeral air infusion technique for detection of the full thickness tear which we used to think as a partial thickness tear, because it was hidden by bursal tissue. Materials and methods : We chose 65 cases and divided them into 2 groups. The group I was 18 cases with partial thickness rotator cuff tears on glenohumeral arthroscopic evaluation, and the group 2 was 37 cases with full thickness rotator cuff tears which were repaired. We inflated the glenohumeral Joint with 50-100ml of air and observed air bubble leakage simultaneously on bursoscopy. Results : In group I, we could detect air leakage in 3 cases and found that it was full thickness tear. In group II, 2 cases revealed too much air leakage proved that it was incomplete repair and was in need of additional suture. Conclusion : Air infusion technique is though to be a valuable method in differentiation between the partial and full thickness tear and for evaluation of the security of the repair.

• Journal of the Korean Institute of Intelligent Systems
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• v.26 no.6
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• pp.439-444
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• 2016

The definition of quality continues to evolve. In recent years, there has been growing interest in how to satisfy customers' potential needs with an emphasis on customer-oriented quality. Two-dimensional quality proposed by Kano provides a useful framework for discovering quality attributes critical to customer satisfaction and it is widely employed for product and service development. In Kano model, quality attributes are classified into attractive, one-dimensional, must-be, indifferent, and reverse ones. Finding attractive elements among them is important for achieving customer satisfaction effectively. However, Kano's classification method has limitations in dealing with customers' ambiguous and complex ideas. The customer response itself includes uncertainty and incompleteness. To overcome this problem, fuzzy methods are incorporated with Kano's classification in this paper. According to numerical comparisons, it is shown that the fuzzy Kano method is useful for accommodating various response of customer and is helpful to identify potential needs.

• Radiation Oncology Journal
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• v.6 no.2
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• pp.195-201
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• 1988

Sixty patients with proven lung cancer were retrospectively studied to determine whether postoperative radiation therapy improves survival. Patterns of treatment failure and 5 year survival were assessed according to extent of tumor spread, histology, type of operation, positive resection margin and radiation dose. Of the 60 patients, excluding S patients who received incomplete treatment or poor pulmonary function,55 patients received postoperative radiation therapy following curative resection. The overall survival at 5 years was $39\%$. The hilar and mediastinal lymph node involvement had an influence on survival. The authors recommend that patients with resection. lung cancer involving the hilar and mediastinal lymph nodes may require postoperative radiotherapy to reduce the local recurrence and improve survival.

• Journal of The Korean Association For Science Education
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• v.21 no.3
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• pp.497-505
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• 2001

In this study, the relationships among students' conceptual understanding of molecular structure and cognitive variables were investigated for 165 high school students. After they had learned 'High School Chemistry II' for two semesters, the tests of conception concerning molecular structure, spatial visualization ability, logical thinking ability, mental capacity, and learning approach were administered. The results indicated that students' conceptual understanding of molecular structure was not sound, and several misconceptions were found. The scores of the conception test were significantly correlated with all the cognitive variables studied. Multiple regression analyses were conducted to examine the predictive influences of students' cognitive variables on their conceptual understanding. Meaningful learning approach was the most significant predictor and were followed by logical thinking ability, rote learning approach, and mental capacity. However, spatial visualization ability did not have the predictive power.

• Journal of Educational Research in Mathematics
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• v.24 no.2
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• pp.125-143
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• 2014

In this study, we analyzed a mathematical discussion in the Calculus II course of the Gifted Science Academy and individual interviews to determine the relationship between cognitive conflicts and commognitive conflicts. The mathematical discussion began with a question from a student who seemed to have a cognitive conflict about the osculating plane of a space curve. The results indicated that the commognitive conflicts were resolved by ritualizing and using the socially constructed knowledge, but cognitive conflicts were not resolved. Furthermore, we found that the cause of the cognitive conflict resulted from the student's imperfect analogical reasoning and the reflective discourse about it could be a learning opportunity for overcoming the conflict. These findings imply that cognitive conflicts can trigger the appearance of commognitive conflicts, but the elimination of commognitive conflicts does not imply that cognitive conflicts are resolved.

• Journal of the Korean Geotechnical Society
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• v.33 no.12
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• pp.93-105
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• 2017

This study presents direct shear tests, model tests, and numerical simulations to assess the effect of reduction of soil strength because of saturation during formation of ground cave-in caused by damaged sewer pipe lines. The direct shear test results show that the saturation affects the cohesion of soil significantly although it does not influence the friction angle of soil. To experimentally reproduce ground cave-in, the model tests were performed. As ground cave-ins were accompanied with extreme deformation, conventional finite element method has difficulty in simulating them. The present study relies on generalized interpolation material point method, which is one of meshless methods. Although there are differences between the model test and numerical simulation caused by boundary conditions, incomplete saturation, and exclusion of groundwater flow, similar ground deformation characteristics are observed both in the model test and numerical simulation.