• 한국통신학회논문지
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• 제38A권6호
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• pp.459-464
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• 2013

본 연구에서는 이차원 인접 심볼간 간섭(2D ISI) 및 인접 페이지간 간섭 (IPI)을 줄이는 홀로그래픽 저장장치를 위한 이차원 변조부호를 선택하는 문제를 고려한다. 변조부호 선택문제는 목적함수로 코드내부와 코드 상호간 인접심볼값의 차이를 최소화하고, 제약식으로는 사용된 심볼의 분포가 균등하며, 최소 해밍거리 조건이 주어진 이차정수계획법 모형으로 수식화되었다. 선택된 코드워드에서 고립된 픽셀의 발생여부를 검색하는 모형은 정수계획법 모형으로 수식화되었다. 제안된 모형들은 4-레벨 6/8 코드 및 2-레벨 6/8 코드에 적용되어 성능을 계산하였다.

• 한국통신학회논문지
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• 제34권2C호
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• pp.163-168
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• 2009

본 논문에서는 홀로그래픽 저장 장치에서 가장 큰 문제점인 고립 픽셀을 허용하지 않는 2차원 변조 부호를 제안한다. 제안하는 2차원 변조 부호는 기존에 사용하던 6/8 변조 부호보다 부호화와 복호화가 간단하며 데이터 검출을 어렵게 하는 1 비트의 고립된 형태를 완벽하게 제거한다. 기존에 사용하던 6/8 변조 부호는 약간의 고립 픽셀을 허용한다. 결과를 보면 blur가 1.4일 때 제안한 변조 부호가 6/8 변조 부호보다 전체적으로 성능이 좋다. 제안한 변조 부호는 수신된 값을 4비트로 양자화 하였을 때 최적의 성능을 낸다.

• 정보처리학회논문지:소프트웨어 및 데이터공학
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• 제7권2호
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• pp.63-68
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• 2018

얼굴인식 분야의 관심은 다양한 신흥분야의 응용에 의해 증강되고 있다. 2-차원적인 인식 알고리즘의 필요성이 어떤 변화무쌍한 환경들, 예를 들어서, 얼굴의 방향이나 조명도, 안경의 유무, 혹은 웃음과 울음 같은 다양한 표정변화의 처리에 적합할 수 있게 고찰 되어 지고 있다. 형상 기억이나 일반화 과정, 유사성 인식, 오류수정 등에 장점을 가지고 있는 홉 필드 네트워크의 기능을 바탕으로 하여 본 연구에서는 새로운 방법의 병렬적인 다중 홉 필드 네트워크를 구성하여 변화에 강한 얼굴표정 인식의 실험을 2-차원 알고리즘으로 실시하였고 결과가 실제적인 얼굴 형상 환경 변화에서 강한 적응성을 가지고 있음을 확인하였다.

• International Journal of Fluid Machinery and Systems
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• 제3권1호
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• pp.58-66
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• 2010

A steam control valve is used to control the flow from the steam generator to the steam turbine in thermal and nuclear power plants. During startup and shutdown of the plant, the steam control valve is operated under a partial flow conditions. In such conditions, the valve opening is small and the pressure deference across the valve is large. As a result, the flow downstream of the valve is composed of separated unsteady transonic jets. Such flow patterns often cause undesirable large unsteady fluid force on the valve head and downstream pipe system. In the present study, various flow patterns are investigated in order to understand the characteristics of the unsteady flow around the valve. Experiments are carried out with simplified two-dimensional valve models. Two-dimensional unsteady flow simulations are conducted in order to understand the experimental results in detail. Scale effects on the flow characteristics are also examined. Results show three types of oscillating flow pattern and three types of static flow patterns.

• 복식문화연구
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• 제20권4호
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• pp.594-603
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• 2012

This study aimed to investigate a bias pattern making method with geometrical approach. The bias-cut dress has soft silhouette of drape in the garment. However, the bias cut dress has problem of satisfying the intended garment size spec. This problem occurs from various sources. The main reason is that the bias-cut fabric tends to stretch on longitudinal direction and to shrink horizontal direction when it was hung on the body. The goal of this study was to develop a bias-cut dress pattern making method satisfying the intended garment size spec. The researchers developed the geometrical method of measuring dimensional change by calculating the compensation ratio of the fabric in true bias direction. The compensation ratio was calculated by applying draping ratio of the fabric. Three types of fabrics were used in the experiment. The warp and weft crossing angle of fabric was ranged from $78^{\circ}$ to $82^{\circ}$. The fabrics stretched longitudinally 6.9~9.9% and shrank horizontally 7.2~11.0%. The compensation ratio of the bias-cut pattern for sample dress was calculated for each fabric type. Two types of experimental bias-cut dress patterns were developed for each fabric. One pattern was made with applying full compensation ratio and the other one made with applying partial ratio of the fabric. Experimental dresses were made with these patterns. The results of the evaluation showed that the bias-cut dress pattern applying the partial compensation ratio was more appropriate than the pattern applying the full compensation ratio.

• 한국의류산업학회지
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• 제20권5호
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• pp.548-555
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• 2018

The purpose of this study is to analyze the patterns of commercial Cheollik dresses by size analysis and wearing evaluation. Six kinds of commercial Cheollik dress patterns distributed on the market were selected and classified into two types group, A type group(A-1, A-2, A-3) consisting of flat type sleeve pattern and B type group(B-1, B-2, B-3) consisting of three-dimensional type sleeve pattern depending on the sleeve type. The size of the Cheollik dress pattern was analyzed, and wearing evaluations of the appearance, movability were carried out. Cheollik dress pattern was made in various size and many patterns were produced in the form of omission of components such as seop. It should be based on the understanding of the form and composition of the traditional Cheollik for pattern development. As a result of the wearing evaluation, A-2 showed the highest evaluation in the appearance and movability evaluations in type A. B-2 was the highest evaluation in appearance evaluation in type B. But in the evaluation of the movability, B-2 received the lowest evaluation because of little allowance. Therefore, the allowance in clothes should be considered enough for the movability. The result of this study can be provided as a basic data for the development of Cheollik dress pattern reflecting modern trend and the traditional beauty.

• 한국의류학회지
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• 제47권1호
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• pp.123-136
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• 2023

To develop smart sportswear capable of measuring biometric data, we created a close-fitting pattern using two- and three-dimensional (2D and 3D, respectively) methods. After 3D virtual fitting, the tightness of each pattern was evaluated using image processing of contact points, mesh deviation, and cross-sectional shapes. In contact-point analysis, the 3D pattern showed high rates of contact with the body (84.6% and 93.1% for shirts and pants, respectively). Compared with the 2D pattern, the 3D pattern demonstrated closer contact at the lower chest, upper arm, and thigh regions, where electrocardiography and electromyography were primarily carried out. The overall average gap was also lower in the 3D pattern (5.27 and 4.66 mm in shirts and pants, respectively). In the underbust, waist, thigh circumference, and mid-thigh circumference, the cross-section distance between clothing and body was showed a statistically significant difference and evenly distributed in the 3D pattern, exhibiting more closeness. The tightness and fit of the 3D smart sportswear sensor pattern were successfully evaluated. We believe that this study is critical, as it facilitates the comparison of different patterns through visualization and digitization through 3D virtual fitting.

• 한국산학기술학회논문지
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• 제16권7호
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• pp.4405-4410
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• 2015

두 개의 1차원 주기 패턴을 수직으로 중첩시켜 상하층 패턴으로부터 이축 변위 정보를 각각 디코딩할 수 있는 방법을 제안한다. 투명한 상층 패턴 판별은 굴절률차에 기인한 레이저 빔의 디플렉션 검출을 통해 이뤄지고 하층 패턴 판별은 수광 전압 차의 검출를 통해 이뤄진다. 빌드 업 필름 재질의 상층 패턴은 UV 레이저 가공에 의해 미세가공되고 그리고 알루미늄 하층 패턴은 초정밀 머시닝에 의한 트렌치 가공과 불투명 소재 증착 그리고 폴리싱 과정을 통해 제작된다. 10마이크로미터 간격으로 제작된 샘플 패턴과 이를 인코딩할 수 있는 전용 광학계에 의한 변위 측정 방법은 대면적 스테이지에 장착되어 레이저 간섭계를 이용한 측정데이터와 비교하여 검증된다.

• Coupled systems mechanics
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• 제5권2호
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• pp.127-144
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• 2016

Two dimensional numerical investigations were carried out to study the influence of interface thickness and their pattern on the behavior of reinforced concrete frames subjected to in-plane lateral loads using commercial finite element tool SAP 2000. The linear elastic analysis was carried out on one and two bay structural systems as well as the influence of number of stories was studied by varying the number of stories as single, three and five. The cement mortar was used as interface material and their effect was studied by varying thicknesses as 6, 8, 10, 14 and 20 mm. The interface was recognized as one sided, two sided, three sided and four sided and their effect was studied by removing the interface material between the reinforced concrete frame and masonry infill. The effect of lateral loads on infill masonry wall was also studied by varying assumed loads as 10, 20, 30, 40, 50 and 60 kN. The behavior of infilled frames studied has revealed that there is a maximum influence of interface thickness and interface pattern corresponding to 10 mm thickness. In general, the lateral displacement of frame is increased linearly with increase in lateral loads.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 1999년도 제29회 춘계학술대회
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• pp.147-155
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• 1999

The film thickness and shape of elastohydrodynamic lubrication is measured by optical interferometer, which is the most precise method for EHL film measurement. However the interpretation of the image pattern from optical viscometer is not easy for two-dimensional shape. A newly developed method of image processing makes it possible to evaluate the film thickness and shape in every point of contact region with two dimensional aspects. In this study, we captured film shape of EHL film from the monochromatic incident light with the Image processing method, which uses phase shift method, and obtained the image analysis method for gray level image in order to qualitatively evaluate film shapes.