• 해양환경안전학회지
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• 제24권1호
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• pp.10-17
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• 2018

종합 안전관리체계인 e-navigation을 준비하기 위해 선박의 의도된 경로를 선박 대 선박, 그리고 선박 대 육상 간에 공유하는 경로교환에 대한 연구가 활발히 진행 중이다. 하지만 경로교환을 위한 기술적인 측면에서의 연구 개발은 진행되고 있으나, 그 효과나 문제점 등 도입 필요성에 대한 연구는 부족한 실정이다. 본 연구는 선박조종 시뮬레이션을 통해 경로교환이 항해 안전에 미치는 영향을 정량적으로 분석하고, 시뮬레이션 수행자들의 주관적인 평가를 종합하여 경로교환의 효과를 검증하였다. 선박 간 경로교환을 할 경우 최초 충돌회피 시점은 평균 3.43분 더 빨라졌으며, 충돌회피 방향은 60 %가 변경되었다. 또한 타선 A와의 최근접점은 31 % 더 가까워지고, 평균 타 사용지수는 57 % 줄어들었다. 그리고 설문 응답자의 95 %는 경로교환이 충돌회피 의사결정에 영향, 85 %는 안전운항에 긍정적인 영향, 90 %는 사고예방 효과, 70 %는 항해사의 심리적 부담 경감, 70 %는 경로교환을 실무에 도입해야한다고 답하였다.

• Journal of Microbiology and Biotechnology
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• 제17권11호
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• pp.1782-1788
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• 2007

Cellulosomes in Clostridium cellulovorans are assembled by the interaction between the repeated cohesin domains of a scaffolding protein (CbpA) and the dockerin domain of enzyme components. In this study, we determined the synergistic effects on cellulosic and hemicellulosic substrates by three different recombinant mini-cellulosomes containing either endoglucanase EngB or endoxylanase XynA bound to mini-CbpA with one cohesin domain (mini-CbpAl), two cohesins (mini-CbpA12), or four cohesins (mini-CbpAl234). The assembly of EngB or XynA with mini-CbpA increased the activity against carboxymethyl cellulose, acid-swollen cellulose, Avicel, xylan, and com fiber 1.1-1.8-fold compared with that for the corresponding enzyme alone. A most distinct improvement was shown with com fiber, a natural substrate containing xylan, arabinan, and cellulose. However, there was little difference in activity between the three different mini-cellulosomes when the cellulosomal enzyme concentration was held constant regardless of the copy number of cohesins in the cellulosome. A synergistic effect was observed when the enzyme concentration was increased to be proportional to the number of cohesins in the mini-cellulosome. The highest degree of synergy was observed with mini-CbpAl234 (1.8-fold) and then mini-CbpAl2 (1.3-fold), and the lowest synergy was observed with mini-CbpAl (1.2-fold) when Avicel was used as the substrate. As the copy number of cohesin was increased, there was more synergy. These results indicate that the clustering effect (physical enzyme proximity) of the enzyme within the mini-cellulosome is one of the important factors for efficient degradation of plant cell walls.

• 노동경제논집
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• 제34권1호
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• pp.33-69
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• 2011

본 연구는 기업수준에서 교육훈련스톡, 연구개발스톡, 특허출원스톡 추계를 통하여 교육훈련활동과 연구개발활동의 생산성 효과에 대하여 분석한다. 특히 교육훈련투자를 스톡으로 구축하여 추정에 이용함으로써 숙련의 자산성을 분석에 반영하였다. 교육훈련투자의 파급효과 분석시 기술적 근접도를 이용한 것과 동적패널 분석을 이용하여 장단기 효과를 구분한 것 역시 방법론상의 새로운 시도이다. 분석 결과, 교육훈련투자의 생산성 효과는 연구개발투자에 비해 상대적으로 더 큰 것으로 나타났다. 교육훈련활동과 연구개발 활동은 자체효과뿐만 아니라 파급효과와 장기효과를 통해 기업의 생산성에 큰 영향을 미친다.

• 한국의류학회지
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• 제38권2호
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• pp.251-265
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• 2014

China is the biggest market for the Korean fashion industry. However, China is still difficult in regards to market entry and market success in China despite the geographical proximity. This study investigated the image of Korea and its impact on brand identity, brand attitude and intention to purchase with a focus on Chinese consumers in order to identify the variables of a country's image that affect a consumer's intention to purchase. The results of this survey targeted 214 Chinese consumers who were used for the final analysis. The survey subjects were female consumers in their 20s and 30s, living in metropolitan cities in China. Exploratory factor, reliability and frequency analyses were conducted using SPSS 19.0; in addition, confirmatory factor and path analyses were administered with AMOS 18.0. We identified two general images of Korea (economy and culture), two images of Korean (stylish and friendly) and three Korean fashion-product related images (quality, design and prestige). The results of the structural equation model were as follows. 1) Economy factor exerted significant effect on quality and prestige. 2) Stylish factor exerted a significant effect on all of the Korean fashion product images (quality, design and prestige). Friendly factor exerted positive impact on prestige. 3) All of the Korean fashion product images significantly influenced brand identity. 4) Brand identity exerted a significant effect on brand attitude. Lastly, brand attitude significantly affected intention to purchase.

• 한국통신학회논문지
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• 제35권1A호
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• pp.87-94
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• 2010

협력 스펙트럼 감지(cooperative spectrum sensing) 방식은 지역적으로 분산되어 있는 다수의 부 사용자들이 협력하여 스펙트럼 감지를 수행하는 방법으로, 페이딩으로 인한 검파 성능의 손실을 효과적으로 줄일 수 있는 것으로 알려져 있다. 지금까지 협력 스펙트럼 감지에 관해 발표된 대부분의 연구 결과들은 부 사용자들의 스펙트럼 감지 결정이 통계적으로 서로 독립이라는 가정에 기초한 것이다. 그러나 실제 환경에서는 음영 효과(shadowing effect)로 인해 서로 가까이에 위치한 부 사용자들의 감지 결정(decision)들은 상관 관계(correlation)를 가질 수 있다. 이런 요인이 협력 스펙트럼 감지 방식의 성능에 미치는 영향을 평가하기 위하여, 본 논문에서는 주 사용자(primary user)가 활동할 때는 서로 다른 부 사용자 2명의 스펙트럼 감지 결정 사이에 일정한 통계적 상관도(correlation)가 존재하고, 활동하지 않는 경우에는 통계적으로 독립인 것으로 CR 시스템 환경을 설정한 후, 통계적 상관도에 따라 전송 용량(throughput)이 어떻게 변화하는 지를 분석하였다. 분석 결과 부 사용자들의 스펙트럼 감지 결정 사이의 상관 계수가 커질수록 OR 융합 규칙을 사용하는 경우에는 전송 용량이 줄어들은 반면 AND 융합 규칙을 사용하는 경우는 전송 용량이 증가하는 것으로 나타났다.

• 한국환경생태학회지
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• 제22권2호
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• pp.128-137
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• 2008

본 연구는 북한산 국립공원을 대상으로 등산로가 산림경관의 파편화에 미치는 영향을 분석한 후, 이를 토대로 소유역별 경관생태학적 건전성을 평가하였다. 등산로 개설에 의한 영향 분석 결과에 따르면, 산림패치의 크기는 감소한 반면 패치 및 가장자리 밀도는 증가한 것으로 나타났다. 또한, 패치형태는 보다 복잡해지고, 핵심지역의 면적은 뚜렷하게 감소하였고, 패치간의 근접도는 증가하는 것으로 나타났다. 한편, 소유역별 경관생태학적 건전성 평가 결과, 종합적인 건전성은 북한산유역이 3.7점으로 가장 높게 나타났으며, 구기유역이 1.6점으로 가장 낮게 평가되었다. 이상의 결과를 종합해 볼 때, 산림의 경관생태학적 보전과 관리를 위해서는 불필요한 등산로의 개설을 금지하고, 훼손 및 교란 지역에 대한 자연적인 생태학적 복원이 이루어져야 할 것으로 판단된다.

• Nuclear Engineering and Technology
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• 제42권6호
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• pp.680-689
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• 2010

The crack-tip stress fields and fracture mechanics assessment parameters for a surface crack, such as the elastic stress intensity factor or the elastic-plastic J-integral, can be affected significantly by the adjacent cracks. Such a crack interaction effect due to multiple cracks can alter the fracture mechanics assessment parameters significantly. There are many factors to be considered, for instance the relative distance between adjacent cracks, the crack shape, and the loading condition, to quantify the crack interaction effect on the fracture mechanics assessment parameters. Thus, the current assessment codes on crack interaction effects (crack combination rules), including ASME Sec. XI, BS7910, British Energy R6 and API 579-1/ASME FFS-1, provide different rules for combining multiple surface cracks into a single surface crack. The present paper investigates crack interaction effects by evaluating the elastic stress intensity factor and the elastic-plastic J-integral of adjacent in-plane surface cracks in a plate through detailed 3-dimensional elastic and elastic-plastic finite element analyses. The effects on the fracture mechanics assessment parameters of the geometric parameters, the relative distance between two cracks, and the crack shape are investigated systematically. As for the loading condition, an axial tension is considered. Based on the finite element results, the acceptability of the crack combination rules provided in the existing guidance was investigated, and the relevant recommendations on a crack interaction for in-plane surface cracks are discussed. The present results can be used to develop more concrete guidance on crack interaction effects for crack shape characterization to evaluate the integrity of defective components.

• 대한간호학회지
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• 제30권5호
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• pp.1133-1144
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• 2000

This study was conducted to evaluate the effects of the program for the autistic children which was designed to promote mother-child attachment. The subjects of this study were consisted of 11 pairs of mother and child( 7 for participant group:PG, 4 for non-participant group: NPG), who were diagnosed as Pervasive Developmental Disorder. The intervention was consisted with play activity centered mother-child interaction, educational activity for mothers, lecture, video-feedback, and supports. The main data were collected by video-taping and analyzed by Wilcoxon Rank Sign Test, and Content Analysis. The results obtained were as follows, 1. Before the program, there were no significant group differences on the children's and the mother's characteristics. After the program, total score on the attachment of PG was higher than that of NPG, but not significant. Only proximity-seeking behaviors and contact-maintaining behaviors were higher significantly(p<.05). Then the characteristics on contact- maintaining behaviors of PG were lasting longer and reciprocal than those of NPG. 2. After the program, the score on mother's nurturing behavior of PG was significantly more increased. The mother's behaviors to her child of PG became more child- centered, positively responsive, expressive supportively. But there were pretty big individual difference. It can be concluded that Mother-child Attachment Promotion Program is effective. Thus it can be recommended to be a early intervention model for autistic children.

• JSTS:Journal of Semiconductor Technology and Science
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• 제14권5호
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• pp.525-536
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• 2014

Recently, the first generation of mass production of FinFET-based microprocessors has begun, and scaling of FinFET transistors is ongoing. Traditional capacitance and resistance models cannot be applied to nonplanar-gate transistors like FinFETs. Although scaling of nanoscale FinFETs may alleviate electrostatic limitations, parasitic capacitances and resistances increase owing to the increasing proximity of the source/drain (S/D) region and metal contact. In this paper, we develop analytical models of parasitic components of FinFETs that employ the raised source/drain structure and metal contact. The accuracy of the proposed model is verified with the results of a 3-D field solver, Raphael. We also investigate the effects of layout changes on the parasitic components and the current-gain cutoff frequency ($f_T$). The optimal FinFET layout design for RF performance is predicted using the proposed analytical models. The proposed analytical model can be implemented as a compact model for accurate circuit simulations.

• 대한산업공학회지
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• 제40권6호
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• pp.628-641
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• 2014

Stepwise efficiency improvement in data envelopment analysis (DEA)-based benchmarking is a realistic and effective method by which inefficient decision making units (DMUs) can choose benchmarks in a stepwise manner and, thereby, effect gradual performance improvement. Most of the previous research relevant to stepwise efficiency improvement has focused primarily on how to stratify DMUs into multiple layers and how to select immediate benchmark targets in leading levels for lagging-level DMUs. It can be said that the sequence of benchmark targets was constructed in a myopic way, which can limit its effectiveness. To address this issue, this paper proposes an optimization approach to the construction of a sequence of benchmarks in DEA-based benchmarking, wherein two optimization criteria are employed : similarity of input-output use patterns, and proximity of input-output use levels between DMUs. To illustrate the proposed method, we applied it to the benchmarking of 23 national universities in South Korea.