• 디지털융복합연구
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• 제11권11호
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• pp.37-52
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• 2013

현재 정부는 본격적인 전력 스마트그리드 확대에 앞서 제주도 구좌읍 6,000호를 대상으로 스마트그리드 실증사업을 추진 중에 있다. 하지만, 관련 기업들은 정부와 한전 주도의 한국 전력시장의 한계, 기존 전력망의 높은 안정성 및 효율성, 신재생에너지 활용도 미흡, 전기요금 인상 우려 등을 이유로 스마트그리드 확산에 대한 부정적인 시각을 가지고 있다. 본 연구는 스마트그리드 시장을 활성화하기 위한 핵심 이슈들을 1) 이해관계자들의 대립 문제, 2) 실시간 요금제 도입에 따른 효과 문제, 3) 소비자들의 수요 반응 참여 부족, 4) 스마트그리드의 비즈니스 모델부재, 5) 스마트그리드 거점지구 확산 문제 등의 5가지로 분류하고, 이에 대한 전략적 방안을 제시하였다.

• The Journal of Advanced Prosthodontics
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• 제5권2호
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• pp.187-197
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• 2013

PURPOSE. The purpose of this study was to evaluate various core designs on stress distribution within zirconia crowns. MATERIALS AND METHODS. Three-dimensional finite element models, representing mandibular molars, comprising a prepared tooth, cement layer, zirconia core, and veneer porcelain were designed by computer software. The shoulder (1 mm in width) variations in core were incremental increases of 1 mm, 2 mm and 3 mm in proximal and lingual height, and buccal height respectively. To simulate masticatory force, loads of 280 N were applied from three directions (vertical, at a $45^{\circ}$ angle, and horizontal). To simulate maximum bite force, a load of 700 N was applied vertically to the crowns. Maximum principal stress (MPS) was determined for each model, loading condition, and position. RESULTS. In the maximum bite force simulation test, the MPSs on all crowns observed around the shoulder region and loading points. The compressive stresses were located in the shoulder region of the veneer-zirconia interface and at the occlusal region. In the test simulating masticatory force, the MPS was concentrated around the loading points, and the compressive stresses were located at the 3 mm height lingual shoulder region, when the load was applied horizontally. MPS increased in the shoulder region as the shoulder height increased. CONCLUSION. This study suggested that reinforced shoulder play an essential role in the success of the zirconia restoration, and veneer fracture due to occlusal loading can be prevented by proper core design, such as shoulder.

• 대한조선학회논문집
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• 제34권1호
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• pp.60-67
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• 1997

본 논문은 WIG 무인 조종 시험선, '한진1호'와 '한진2호'의 날개에 대한 3차 시험 결과를 수록하고 있다. 지난 95년 5월에 당 연구소에서는 '한진1호'를 설계 제작하여 시험비행에 성공하였으며, 아울러 지면효과에 따른 공기역학적 특성을 파악하기 위하여 풍동에서 여러가지 날개단면에 대한 양력 및 항력을 계측하였다. 이 실험결과에 의하면 지면에 가까워질수록 양력 및 양항비는 증가되지만, 그 특성들은 주로 날개 단면의 형상에 영향을 받고 있음을 알 수 있었다. 따라서 본 논문에서는 우선 '한진1호'에 사용된 NACA6409 익형과 러시아에서 WIG선용으로 개발한 DHMTU계열의 익형 2종을 선택하고, 풍동실험을 통하여 그들의 양력 및 항력 특성을 비교하였다. 특히 본 실험에서는 종방향 운동에 대한 안정성을 파악하기 위해서 피칭모멘트를 계측 비교하였다. 실험결과에 의하면 피칭모멘트의 절대값은 코오드 길이의 1/4 에서 NACA6409 보다 DHMTU 계열이 적게 계측되었다.

• 한국기록관리학회지
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• 제11권1호
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• pp.231-252
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• 2011

이 논문은 문화유산기관 아카이브 포탈의 대중화와 지속적인 이용을 위해 퀄리티 포탈에 필요한 요소들을 살펴보았다. 이용자에 대한 이해가 문화유산기관 아카이브 포탈의 성공에 결정적임에도 불구하고 많은 연구가 되어오지 않은 점을 감안하여, 타 포탈들의 퀄리티 분석에 적용된 이용자 중심 평가모델들을 정리하였다. Intrinsic bias를 피하기 위해 triangulation 방법론을 선택하였으며, 이에 서비스 품질(Service Quality), 데이타 품질(Data Quality), 그리고 기술수용모델(Technology Acceptance Model: TAM)을 분석 정리하여 문화유산기관의 아카이브 포탈에 적합한 평가모델을 제시하였다. 제시된 평가모델을 검증하기 위한 99 항목 설문도 제안하였다. 후속 연구에서는 설문의 타당성과 평가모델의 적합성이 실증적으로 검증될 계획이다.

• 대한치과보철학회지
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• 제30권4호
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• pp.582-610
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• 1992

The long-term success of any dental implant is dependent upon the optimization of stresses which occur during oral function and parafunction. Especially, it has been suggested that there is an unique set of problems associated with joining an osseointegrated implant and a natural tooth with a fixed partial denture. For this particular case, although many literatures suggest different ways to avoid high stress concentrations on the bone surrounding the implant under static and dynamic loading conditions, but few studies on the biomechanical efficacy of each assertion have been reported. The purpose of this investigation was to evaluate the efficacies of clinically suggested methods on stress distribution under static load and shock absorption under dynamic load, using two dimensional finite element method. In FEM models of osseointegrated implant-natural tooth supported fixed partial dentures, calculations were made on the stresses in surrounding bone and on the deflections of abutments and superstructure, first, to compare the difference in stress distribution effects under static load by the flexure of fastening screw or prosthesis, or intramobile connector, and second, to compare the difference in the shock absorption effects under dynamic load by intramobile connector or occlusal veneering with composite resin. The results of this analysis suggest that : 1. Under static load condition, using an implant design with fastenign screw connecting implant abutment and prosthesis or increasing the flexibility of fastening screw, or increasing the flexibility of prosthesis led to the .increase in height of peak stresses in cortical bone surrounding the implant, and has little effect on stress change in bone around the natural tooth. 2. Under static load condition, intramobile connector caused the substantial decrease in stress concentration in cortical bone surrounding the implant and the slight increase in stress in bone around the natural tooth. 3. Under dynamic load condition, both intramobile connector and composite resin veneering showed shock absorption effect on bone surrounding the implant and composite resin veneering had a greater shock absorption effect than intramobile connector.

• 정보보호학회논문지
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• 제29권6호
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• pp.1383-1392
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• 2019

적대적 공격은 기계학습 분류 모델의 오분류를 유도하는 적대적 데이터를 생성하는 공격으로, 실생활에 적용된 분류 모델에 혼란을 야기하여 심각한 피해를 발생시킬 수 있다. 이러한 적대적 공격 중 블랙박스 방식의 공격은, 대상 모델과 유사한 대체 모델을 학습시켜 대체 모델을 이용해 적대적 데이터를 생성하는 공격 방식이다. 이 때 사용되는 야코비 행렬 기반의 데이터 어그멘테이션 기법은 합성되는 데이터의 왜곡이 심해진다는 단점이 있다. 본 논문은 기존의 데이터 어그멘테이션 방식에 존재하는 단점을 보완하기 위해 감쇠 요소를 추가한 데이터 어그멘테이션을 사용하여 대체 모델을 학습시키고, 이를 이용해 적대적 데이터를 생성하는 방안을 제안한다. 실험을 통해, 기존의 연구 결과보다 공격 성공률이 최대 8.5% 가량 높음을 입증하였다.

• 정보처리학회논문지D
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• 제18D권3호
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• pp.185-196
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• 2011

최근 보건의료 분야와 정보통신 기술이 접목된 u-Healthcare에 대해 원격진료 제한을 완화하는 의료법 개정안이 입법 예고되면서 u-Healthcare 수요 창출을 위한 비즈니스 모델로 IPTV를 이용한 서비스가 등장하였다. 하지만, 의료서비스에 IPTV 기술을 도입함으로써 환자의 치료방법의 개선, 서비스 질의 향상, 치료의 효용성 증가 등의 많은 이점들이 예상처럼 도입되고 있지 못하고 있는데, 이는 아직 정비되지 않은 법, 제도적 환경뿐만 아니라 사용자 수용 연구를 통한 전략 마련이 부족했음을 인정하지 않을 수 없다. 본 연구는 IPTV를 통해 제공되는 의료서비스를 수용하는데 있어서 연결되는 순차적인 관계를 검증하고, 분석된 결과를 토대로 IPTV 기반 의료서비스의 활성화 방안을 제시하였다. 연구 결과 IPTV 기술 품질의 편의성, 콘텐츠 품질의 완결성, 그리고 Healthcare 서비스 품질이 만족도를 이끌어 내는 주요 요소들로 추출되었고, 전반적으로 IPTV 기술 품질, 콘텐츠 품질, Healthcare 서비스 품질 모두 만족도에 유의한 영향을 미치는 것으로 분석되었으며, 본서비스의 만족도는 사용의도에 유의한 영향을 미치는 것으로 나타났다.

• Biotechnology and Bioprocess Engineering:BBE
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• 제8권4호
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• pp.246-251
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• 2003

The blood-brain barrier (BBB) is composed of the brain capillaries, which are lined by endothelial cells displaying extremely tight intercellular junctions. Several attempts at creating an in vitro model of the BBB have been met with moderate success as brain capillary endothelial cells lose their barrier properties when isolated in cell culture. This may be due to a lack of recreation of the in vivo endothelial cellular environment in these models, including nearly constant contact with astrocyte foot processes. This work is motivated by the hypothesis that growing endothelial cells on one side of an ultra-thin, highly porous membrane and differentiating astrocyte or astrogliomal cells on the opposite side will lead to a higher degree of interaction between the two cell types and therefore to an improved model. Here we describe our initial efforts towards testing this hypothesis including a procedure for membrane fabrication and methods for culturing endothelial cells on these membranes. We have fabricated a 1 $\mu\textrm{m}$ thick, 2.0 $\mu\textrm{m}$ pore size, and 55% porous membrane with a very narrow pore size distribution from low-stress silicon nitride (SiN) utilizing techniques from the microelectronics industry. We have developed a base, acid, autoclave routine that prepares the membranes for cell culture both by cleaning residual fabrication chemicals from the surface and by increasing the hydrophilicity of the membranes (confirmed by contact angle measurements). Gelatin, fibronectin, and a 50/50 mixture of the two proteins were evaluated as potential basement membrane protein treatments prior to membrane cell seeding. All three treatments support adequate attachment and growth on the membranes compared to the control.

• 대한의용생체공학회:의공학회지
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• 제29권3호
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• pp.212-221
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• 2008

The total hip replacement (THR) has been used as the most effective way to restore the function of damaged hip joint. However, various factors have caused some side effects after the THR. Unfortunately, the success of the THR have been decided only by the proficiency of surgeons so far. Hence, It is necessary to find the way to minimize the side effect caused by those factors. The purpose of this study was to suggest the definite data, which can be used to design and choose the optimal hip implant. Using finite element analysis (FEA), the biomechanical condition of bone cement was evaluated. Stress patterns were analyzed in three conditions: cement mantle, procimal femur and stem-cement contact surface. Additionally, micro-motion was analyzed in the stem-cement contact surface. The 3-D femur model was reconstructed from 2-D computerized tomography (CT) images. Raw CT images were preprocessed by image processing technique (i.e. edge detection). In this study, automated edge detection system was created by MATLAB coding for effective and rapid image processing. The 3-D femur model was reconstructed based on anatomical parameters. The stem shape was designed using that parameters. The analysis of the finite element models was performed with the variation of parameters. The biomechanical influence of each parameter was analyzed and derived optimal parameters. Moreover, the results of FE A using commercial stem model (Zimmer's V erSys) were similar to the results of stem model that was used in this study. Through the study, the improved designs and optimal factors for clinical application were suggested. We expect that the results can suggest solutions to minimize various side effects.

• 한국지능정보시스템학회:학술대회논문집
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• 한국지능정보시스템학회 2005년도 공동추계학술대회
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• pp.241-250
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• 2005

New product development (NPD) is defined as the transformation of a market opportunity and a set of assumptions about product technology into a product available for sale. Managers charged with project selection decisions in the NPD process, such as go/no-go choices and specific resource allocation decisions, are faced with a complicated problem. Therefore, the ability to develop new successful products has identifies as a major determinant in sustaining a firm's competitive advantage. The purpose of this study is to develop a new evaluation model for NPD project selection in the high -tech industry using support vector machines (SYM). The evaluation model is developed through two phases. In the first phase, binary (go/no-go) classification prediction model, i.e. SVM for high-tech NPD project selection is developed. In the second phase. using the predicted output value of SVM, feasibility grade is calculated for the final NPD project decision making. In this study, the feasibility grades are also divided as three level grades. We assume that the frequency of NPD project cases is symmetrically determined according to the feasibility grades and misclassification errors are partially minimized by the multiple grades. However, the horizon of grade level can be changed by firms' NPD strategy. Our proposed feasibility grade method is more reasonable in NPD decision problems by considering particularly risk factor of NPD in viewpoints of future NPD success probability. In our empirical study using Korean NPD cases, the SVM significantly outperformed ANN and logistic regression as benchmark models in hit ratio. And the feasibility grades generated from the predicted output value of SVM showed that they can offer a useful guideline for NPD project selection.