• 한국BIM학회 논문집
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• 제9권3호
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• pp.30-40
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• 2019

Extraction of fabrication documents is very important because it provides information related to tasks of fabrication and construction. Therefore, in the case of a prefabricated member such as a steel structure, it is necessary to improve the productivity of fabrication documents through 3D BIM. However, research and evidence data on direct comparison analysis of 3D BIM-based documents extraction versus 2D CAD-based documents extraction are hard to find. Thus, this study focuses on productivity analysis of 3D BIM based fabrication documents extraction. In this study, the productivity data of fabrication documents extraction for module construction of EPC project was analyzed. For the productivity analysis, a case study on the fabrication documents of Module A (1,965 sheets) and Module B (1,216 sheets) was conducted. Fabrication documents for each module include general arrangement drawing, assembly drawing, single part drawing and single plate drawing. Comparison of 2D CAD based fabrication documents extraction and 3D BIM based fabrication documents extraction, the productivity for the entire work was improved from 17 hours to 16 hours for Module A and 12 hours to 7 hours for Module B. Especially, the productivity of the assembly drawings, which occupies a large part of the fabrication documents, was improved by about 48.75% from the total time required from 281 hours to 144 hours.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
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• pp.408-410
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• 2003

In this paper, an improved gradient direction assisted linking algorithm is proposed. This algorithm begins with initial seeds satisfying some local criteria. Then it will search along the direction provided by the initial point. A window will be generated in the gradient direction of the current point. Instead of the conventional method which only considers the value of the local salient structure, an improved mathematical model is proposed to describe the desired linear features. This model not only considers the value of the salient structure but also the direction of it. Furthermore, the linking problem under this model can be efficiently solved by dynamic programming method. This algorithm is tested for linear features detection in IKONOS images. The result demonstrates this algorithm is quite promising.

• 한국멀티미디어학회논문지
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• 제22권12호
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• pp.1347-1355
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• 2019

Deep learning approach based on convolution neural network (CNN) has extensively studied in the field of computer vision. However, periocular feature extraction using CNN was not well studied because it is practically impossible to collect large volume of biometric data. This study uses the ResNet model which was trained with the ImageNet dataset. To overcome the problem of insufficient training data, we focused on the training of multi-layer perception (MLP) having simple structure rather than training the CNN having complex structure. It first extracts features using the pretrained ResNet model and reduces the feature dimension by principle component analysis (PCA), then trains a MLP classifier. Experimental results with the public periocular dataset UBIPr show that the proposed method is effective in person authentication using periocular region. Especially it has the advantage which can be directly applied for other biometric traits.

• 한국자기공명학회논문지
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• 제15권1호
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• pp.14-24
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• 2011

We have performed Liquid Chromatography-Solid Phase Extraction-NMR (LC-SPE-NMR) analysis for liquid crystalline mixture and elucidated the structures of selected components by NMR spectra. Combining the results of one-dimensional 1H experiments as well as homonuclear and heteronuclear two-dimensional experiments, we could analyze the molecular structure of the liquid crystal singles whose structure had not been interpretable by mass spectrometry alone.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 추계학술대회 논문집 학회본부
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• pp.302-304
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• 1997

Chemical structure and electrical properties such as water treeing and space charge accumulation of various raw materials(XLPE) used for power cable insulation were investigated. It was found that chemical structure was changed after crosslinking reaction and every materials have different amounts of DCP and antioxidant. Electrical properties were also changed after extraction using $CHCl_3$ and xylene. Water tree length was smaller with additives such as DCP and antioxidant and bigger with low molecular weight components of polyethylene than that of extracted samples. Heterocharge was changed into homocharge after extraction. This shows that additives and low molecular weight components of polyethylene cause the heterocharge.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2002년도 춘계종합학술대회
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• pp.275-278
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• 2002

MOSFET의 게이트 길이가 50nm이하로 작아지면 소자를 설계함에 있어 고려해야 하는 많은 문제점들이 존재하게 된다. 본 논문에서는 MOSFET 소자에 대한 문턱 전압 특성을 조사하였다. 소자에 대한 스케일링은 generalized scaling을 사용하였고 게이트 길이 100nm에서 30nm까지 시뮬레이션 하였다. 이때 나노 구조 MOSFET에 대한 스케일링의 한계를 볼 수 있었다. 문턱 전압을 구하는 방법으로는 선형 추출 방법을 사용하였다.

• 열처리공학회지
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• 제21권6호
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• pp.320-325
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• 2008

• 한국지하수토양환경학회지:지하수토양환경
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• 제14권3호
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• pp.57-67
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• 2009

토양미생물은 토양 및 퇴적토 환경에서 생물학적 물질순환의 중요한 역할을 맡고 있다. 이러한 중요성으로 인해 토양미생물 생태 다양성과 군집구성이 토양 및 퇴적토 생태환경과 자연저감능력을 평가하는 지표로 유용하게 쓰일 수 있다. 보다 정확한 다양성과 군집구조 분석을 위해서는 다양한 토양 및 퇴적토 시료로부터 분석에 필요한 DNA수율과 순도를 확보해야 한다. 지금까지 토양 및 퇴적토에서 DNA추출하는 방법들에 대한 다양한 기초연구가 이루어졌지만, 실제 환경생태영향평가와 분해기능평가에 사용시 DNA추출방법 선정에 대한 지침 및 정보는 매우 부족하다. 이에 본 연구에서는 문헌조사를 통해서 다양한 방법들의 토양 및 퇴적토 내 미생물 DNA 추출 특성을 비교 분석하고, 현재 주로 사용되고 있는 DNA추출방법을 토양 및 퇴적토 환경평가나 오염지하수토양 자연저감능평가에 활용 할 경우 고려해야 할 기술적 사항에 대해 고찰하였다. 본 연구를 통해 하나의 특정 추출 방법으로는 미생물다양성, 군집구성 및 개체간 상호작용에 대한 정보를 얻기에는DNA양과 순도 차원에서 충분하지 않으며, 토양 및 퇴적토 미생물 군집분석의 목적에 따라 적합한 방법의 선택이 매우 중요함을 알 수 있었다.

• 전자공학회논문지CI
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• 제47권2호
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• pp.11-20
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• 2010

본 논문에서는 피부색 정보를 이용한 얼굴 후보 검출 방법과 얼굴의 구조적 특징을 이용한 얼굴 확인 방법으로 구성된 얼굴 검출 시스템을 제안한다. 먼저 제안하는 얼굴 후보 검출 방법은 피부색 영역과 피부색의 주변 영역에 대한 이미지 분할과 병합 알고리듬을 이용한다. 이미지 분할과 병합 알고리듬의 적용은 복잡한 이미지에 존재하는 다양한 얼굴들을 후보로 검출할 수 있다. 그리고 제안하는 얼굴 확인 방법은 얼굴을 지역적인 특징에 따라 분류 가능한 부분 얼굴 분류기를 사용하여 얼굴의 구조적 특징을 판단하고, 얼굴과 비-얼굴을 구별한다. 부분 얼굴 분류기는 학습 과정에서 얼굴 이미지만을 사용하고, 비-얼굴 이미지는 고려하지 않기 때문에 적은 수의 훈련 이미지를 사용한다. 실험 결과 제안한 얼굴 후보 검출 방법은 기존의 방법보다 평균 9.55% 많은 얼굴을 후보로 검출하였다. 그리고 얼굴/비-얼굴 분류 실험에서 비-얼굴에 대한 분류율이 99%일 때 기존의 분류기보다 평균 4.97% 높은 얼굴 분류율을 달성 하였다.

• ETRI Journal
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• 제36권5호
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• pp.847-855
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• 2014

We developed a highly refractive index planarization layer showing a very smooth surface for organic light-emitting diode (OLED) light extraction, and we successfully prepared a highly efficient white OLED device with an embossed nano-structure and highly refractive index planarization layers. White OLEDs act as an internal out-coupling layer. We used a spin-coating method and two types of $TiO_2$ solutions for a planarization of the embossed nano-structure on a glass substrate. The first $TiO_2$ solution was $TiO_2$ sol, which consists of $TiO_2$ colloidal particles in an acidic aqueous solution and several organic additives. The second solution was an organic and inorganic hybrid solution of $TiO_2$. The surface roughness ($R_a$) and refractive index of the $TiO_2$ planarization films on a flat glass were 0.4 nm and 2.0 at 550 nm, respectively. The J-V characteristics of the OLED including the embossed nano-structure and the $TiO_2$ planarization film were almost the same as those of an OLED with a flat glass, and the luminous efficacy of the aforementioned OLED was enhanced by 34% compared to that of an OLED with a flat glass.