• Structural Engineering and Mechanics
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• 제12권5호
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• pp.475-490
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• 2001

Remeshing strategies are formulated for r-adaptive and h/r-adaptive analysis of crack propagation. The relocation of the nodes, which typifies r-adaptivity, is a very cheap method to optimise a given discretisation since the element connectivity remains unaltered. However, the applicability is limited. To further improve the finite element mesh, a combined h/r-adaptive method is proposed in which h-adaptivity is applied whenever r-adaptivity is not capable of further improving the discretisation. Two and three-dimensional examples are presented. It is shown that the r-adaptive approach can optimise a discretisation at minimal computational costs. Further, the combined h/r-adaptive approach improves the performance of a fully r-adaptive technique while the number of h-remeshings is reduced compared to a fully h-adaptive technique.

• 대한약학회:학술대회논문집
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• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2-2
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• pp.118.1-118.1
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• 2003

SS cream and its revised formula, CJ-4001 is topical Chinese herbal drugs for premature ejaculation. To evaluate the genotoxic potentials of these drugs, micronucleus test using Acridine orange (AO) staining method was performed. Acridine orange (AO) staining is adopted in OECD guideline 474 and widely used in micronucleus test. In dose range finding study, no mouse was dead at 2000 mg/kg using single treatment subcutaneously. Therefore, 3 dose levels were chosen at 500, 1000, 2000 mg/kg. (omitted)

• 한국치위생학회지
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• 제15권5호
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• pp.805-811
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• 2015

Objectives: The purpose of the study is to investigate the relationship between self-efficacy and learning attitude according to smoking experience in the middle school students. Methods: A self-reported questionnaire was completed by 608 middle school students in Gyeongnam from July 1 to 23, 2013. The questionnaire consisted of general characteristics of the subjects, smoking behavior, self-efficacy, and learning attitude. The questionnaire was adapted and modified from Kang, Park, and Koh. The self-efficacy was divided into general efficacy and social efficacy. The learning attitude was divided into attention concentration, learning method, and self learning. Data were analyzed using SPSS Win 21.0 program. Results: The nonsmoking students tended to have higher general efficacy and social efficacy than the smokers (p<0.01). The nonsmokers had more attention concentration in learning attitude than the smokers (p<0.001). The learning method (p<0.001) and self learning (p<0.001) showed the same results between the two groups. The smoking experience had the negative correlation with general efficacy (r=-0.164) and social efficacy(r=-0.154). The general efficacy is positively related to social efficacy (r=0.568). The smoking experience had the negative correlation to attention concentration (r=-0.235), learning method (r=-0.211) and self learning (r=-0.148). The attention concentration was positive relation with learning method (r=0.690) and self learning(r=0.662. The learning method had positive relation to self learning (r=0.764). Conclusions: The smoking students tended to have lower self-efficacy and learning attitude, so it is necessary to implement the smoking prevention program in the middle school students.

• 한국정보통신학회논문지
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• 제17권4호
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• pp.945-952
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• 2013

QRS 영역 중 R파는 ECG 신호 중 가장 큰 대표 신호라 할 수 있으며, 이 점을 기준으로 다양한 특징점을 검출하기 때문에 R파의 검출성능을 높이기 위해 많은 노력을 기울여 왔다. 하지만 R파 검출은 여러 종류의 잡음성분들로 인하여 이를 분석하는데 어려움을 준다. 또한 QRS 영역의 진폭과 유사한 T파나 P파를 R파로 오인함으로써 검출의 어려움이 발생한다. ECG 신호처리는 하드웨어 및 소프트웨어 자원에 대한 효율성을 고려해야 하며, 소형화 및 저 전력을 위해 단순해야 한다. 즉, 최소한의 연산량으로 정확한 R파를 검출함으로써 다양한 부정맥을 분류할 수 있는 적합한 알고리즘의 설계가 필요하다. 따라서 본 연구에서는 차감 동작 기법(Subtractive Operation Method, 이하 SOM) 기반의 심전도 신호의 R파 검출 방법을 제안한다. 이를 위해 형태 연산을 통한 전처리 과정과 경험적 문턱값과 차감신호를 통해 R파를 검출하였으며, 검출의 효율성을 위하여 RR 간격을 이용한 동적 역탐색 기법을 적용하였다. 제안한 알고리즘의 R파 검출 성능을 평가하기 위해서 MIT-BIH 부정맥 데이터베이스를 사용하였다. 성능평가 결과, R파는 평균 99.41%의 검출결과가 나타났다.

• Journal of Magnetics
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• 제21권3호
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• pp.303-307
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• 2016

$Y_{3-x}R_xFe_5O_{12}$ (R = La, Nd, and Gd) powder were fabricated using a sol-gel pyrolysis method. Their magnetic properties and crystalline structures were investigated using x-ray diffraction (XRD), a vibrating sample magnetometer (VSM), and $M{\ddot{o}}ssbauer$ Spectrometer. The $M{\ddot{o}}ssbauer$ spectra for the powders were taken at various temperatures ranging from 12 K to Curie temperature (Tc). The isomer shifts indicated that the valence states of Fe ions for the 16(a) and 24(d) sites have a ferric character. The saturation magnetization (Ms) increases from 32 to 34 (emu/g) for the YIG, and Nd-YIG, respectively. However, Ms decreases to 27 (emu/g) at Gd-YIG.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 1997년도 특별강연 및 춘계학술발표 개요집
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• pp.91-98
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• 1997

This research is to evaluate of the J-R curve characteristic in 5083 aluminum alloy weldment by utilizing the load ratio analysis. This analysis method can be evaluated the J-R curve only with load-displacement curve without any particular precision instrument equipment in CT specimen. For validity, the results of the load ratio analysis are compared with the those of the J-R curve, which are obtained by the ASTM standard unloading compliance method. The calculated crack length of the load ratio analysis is well appropriate that the measured final crack length. And the J-R curve slope estimated by the load ratio analysis is slightly smaller than that by the ASTM unloading compliance method.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2002년도 International Meeting on Information Display
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• pp.852-855
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• 2002

Quality of the reflective LCD as a display is strongly influenced by the environment where the display is evaluated. Up to now, several methods for the evaluation of the reflective LCDs have been proposed. We have developed a new method in which the optical characteristics of the reflective LCDs from the spot light and the diffuse light can be obtained at the same time. The results obtained in our experiments by using the new method showed a good agreement with those evaluated at office and outdoor environments.

• 산업경영시스템학회지
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• 제14권23호
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• pp.57-64
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• 1991

The preliminary, advanced and final evaluation of R&D project is essential in order to reduce loss of resource and opportunity and to minimize uncertainty resulting from optimal selection and efficient progress of R&D project. This thesis examined characteristics of deterministic evaluation, economical evaluation, and OR-approach evaluation as theoretical methodology of evaluation of R&D project applicable to food industry in Korea by using scoring method, one of deterministic evaluations. In addition, this thesis divided the evaluation factors for preliminary evaluation of R&D project into 5 groups and 30 factors on basis of the environment of domestic companies and set up the standard of each evaluation factors and contains marking-selecting way. But, generally, the evaluation model by this thesis, as the conditions of the business company environment are different to each other, contents to be set up evaluation factors, evaluation standard and decision method conforming to each the environment of the business companies with referring to as one standard of evaluation project for selecting R&D project.

• 한국산학기술학회논문지
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• 제22권2호
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• pp.721-732
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• 2021

본 연구는 농업 R&D의 추세를 살펴보고자 텍스트마이닝 기법을 활용하여 농업 R&D에 해당하는 키워드를 분석하였다. 분석자료는 NTIS의 국가연구개발사업 과제정보를 활용하였으며, 2003년부터 2018년까지의 농업 R&D의 주요 키워드를 연도별 및 연구개발단계별로 구분하였다. 텍스트마이닝을 위해 키워드의 TF-IDF를 계산하여 점수별로 순위를 매기었으며, 유사한 키워드별로 그룹화하여 해석하였다. 주요 분석 결과는 다음과 같다. 첫 번째, 신기술의 도입과 외부 환경에 변화에 따른 농업 R&D 트렌드가 변화해가고 있다. 시간이 흐를수록 새로운 키워드가 대두되고 있으며, 기초연구 단계에서는 '기후변화'가, 응용연구 단계에서는 'ICT'와 '스마트팜'이, 개발연구 단계에서는 '수출' 키워드가 주되게 등장하고 있다. 두 번째, 연구개발 단계에서 시차를 가지고 키워드 변화가 나타나고 있다. 기초연구-응용연구-개발연구 순으로 주요 키워드가 변화하고 있으며, 대표적으로 '기후변화'와 '신품종' 키워드가 연구개발단계별로 연계되어 있었다. 세번째, 농업 R&D의 대표적인 키워드는 '벼' 키워드로 나타났다. 그러나 '녹색 및 기후변화 대응'과 '가공 및 유통기술' 같이 국내외 농업 환경 변화에 따라 연구의 방향성과 목적이 변화하고 있었다.

• 한국공작기계학회논문집
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• 제15권3호
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• pp.73-81
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• 2006

This paper describes our primary study for a new method of recognizing materials, which is need for precision work system. This is a study of dynamic characteristics of smart sensors, new method$(R_{SAI})$ has the sensing ability of distinguishing materials. Experiment and analysis are executed for finding the proper dynamic sensing condition. First, we developed advanced smart sensor. We made smart sensors for experiment. The type of smart sensor is HH type. The smart sensor was developed for recognition of material. Second, we develop new estimation methods that have a sensing ability of distinguish materials. Dynamic characteristics of sensor are evaluated through new recognition index$(R_{SAI})$ that ratio of sensing ability index. Distinguish of object is executed with $R_{SAI}$ method relatively. We can use the $R_{SAI}$ method for finding materials. Applications of this method are finding abnormal condition of object (auto-manufacturing), feeling of object(medical product), robotics, safety diagnosis of structure, etc.