• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 춘계학술대회
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• pp.660-665
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• 2003

The true stress - true strain relation of SA508 steel was evaluated with analytical and experimental equation on the base of the indentation load-depth curve obtained from the modeling of ball indentation test. The evaluated relation between true stress and true strain is agreed well with that of SA508 teel defined in the modeling. The distribution of effective stress along the center axis of indentation depth was calculated with Tresca criteria in the modeling. The representative strain, which are defined in this study as the corresponding strains obtained from the maximum effective stress, have a linear relation with the true strain. The true stress - true strain relation of austenitic stainless steel was evaluated by the modeling of ball indentation test to verify the case of A508 steel.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2008년도 International Meeting on Information Display
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• pp.51-54
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• 2008

In this paper, we propose a practical method for displaying 2D/True3D mixed contents in real-time. Many companies released their 3D display recently, but the costs of producing True3D contents are still very expensive. Since there are already a lot of 2D contents in the world and it is more effective to mix True3D objects into the 2D contents than making True3D contents directly, people became interested in mixing 2D/True3D contents. Moreover, real-time 2D/True3D mixing is helpful for 3D displays because the scenario of the contents can be easily changed on playback-time by adjusting the 3D effects and the motion of the True3D object interactively. In our system, True3D objects are rendered into multiple view-point images, which are composed with 2D contents by using depth information, and then they are multiplexed with pre-generated view masks. All the processes are performed on a graphics processor. We were still able to play a 2D/True3D mixed contents with Full HD resolution in real-time using a normal graphics processor.

• 대한기계학회논문집A
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• 제33권10호
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• pp.1054-1064
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• 2009

본 연구에서는 인장시험 및 유한요소해석으로 재료의 파단 진변형률을 구하고, 궁극적으로 재료의 진응력-진변형률을 얻는 방법을 제안했다. 먼저 인장시험으로 얻은 응력-변형률 선도를 네킹점에서 선형 외삽해, 초기 진응력-진변형률 곡선을 설정하고, 이를 유한요소해석에 채택했다. 유한요소해석 후 Bridgman 계수 및 평판 수정계수들을 사용해, 단축 상태의 하중-진변형률 선도를 얻어 파단진변형률을 실험-해석적으로 구했다. 이 예측 파단진변형률의 실험치 대비 오차는 3% 미만이다. 이렇게 구한 파단 진변형률과 이에 상응하는 파단진응력을 구해 파단점을 결정한다. 이어 네킹점과 결정한 파단점을 연결하는 네킹 후 진응력-진변형률 선형선도를 확보하고, 이를 네킹 전의 실험선도와 결합해 최종적으로 재료의 진응력-진변형률 선도를 완성했다. 본 연구에서 제시한 실험-해석적 진응력-진변형률 곡선 획득 방법은 SS400 평판시편과 같이 파단면적 측정이 어려운 경우, 그 유용함이 배가된다.

• 핵의학기술
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• 제15권2호
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• pp.83-87
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• 2011

최근 진단분야에서 PET/CT는 종양학 분야뿐만 아니라 심장 신경 등 여러 가지 분야에서 널리 활용되고 있다. PET/CT의 중요성이 높아지면서 영상의 질과 관련된 재구성 방법에 대한 연구도 활발히 진행되고 있다. 이 중 Siemens사의 TrueX 재구성 방법을 phantom 실험을 통해 Iterative 2D 재구성 방법과 비교 평가하여 임상적 유용성을 높이고자 하였다. 선량에 따른 영상을 비교 평가하기 위해 contrast ratio와 FWHM을 측정하였고 Biograph 40 True Point PET/CT (Siemens, Germany)를 사용하여 실험을 실시하였다. Contrast ratio를 구하기 위해 NEMA IEC PET body phantom (Data Spectrum Corp.)을 이용하였고, FWHM을 측정하기 위해 capillary tube를 사용하였다. 모든 영상은 10분씩 획득하였고, 영상 재구성은 현재 사용하고 있는 TrueX와 기존에 사용하던 Itertive 2D 알고리즘을 사용하였다. Iterative 2D는 임상에 적합한 parameter 조건을 적용하고 TrueX는 Siemens에서 권고하는 parameter를 적용하여 실험하였다. Capillary tube를 사용하여 FWHM을 측정한 결과, TrueX가 Iterative 2D 방식보다 낮게 나왔다. 저선량일수록 FWHM의 차이가 점점 커졌다. NEMA IEC PET body phantom을 사용하여 contrast ratio를 구한 결과, TrueX가 Itertive 2D보다 좋은 양상을 보였다. 그러나 선량에 따른 차이는 보이지 않았다. 본 연구에서는 영상 분석을 통해 TrueX가 Itertive 2D보다 contrast ratio와 spatial resolution이 높게 나타났다. 또한 TrueX를 통한 재구성 결과 저선량일수록 기존의 Iterative 2D보다 resolution은 좋은 양상을 보였고 contrast ratio는 큰 변화를 보이지 않았다. 즉 PET/CT에서 TrueX 재구성 기법이 환자의 피폭도 절감하고 질적으로 우수한 영상을 구현할 수 있어 임상적 이용가치가 높다고 생각된다.

• 한국시뮬레이션학회논문지
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• 제11권3호
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• pp.35-48
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• 2002

In the work presented here, we describe a method to extract TrueType features for supporting letter recognition. Even if variously existing document processing techniques have been challenged, almost few methods are capable of recognize a letter associated with its TrueType features supporting OCR free, which boost up fast processing time for image text retrieval. By reviewing the mechanism generating digital fonts and birth of TrueType, we realize that each TrueType is drawn by its contour of the glyph table. Hence, we are capable of deriving the segment with density for a letter with a specific TrueType, defined by the number of occurrence over a segment width. A certain number of occurrence appears frequently often due to the fixed segment width. We utilize letter recognition by comparing TrueType feature library of a letter with that from input word images. Experiments have been carried out to justify robustness of the proposed method showing acceptable results.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
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• pp.940-942
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• 2003

In an attempt to enhance the visual effect of SPOT image, this study develops a neural network algorithm to transform SPOT false color into simulated true color. The method has been tested using Landsat TM and SPOT images. The qualitative and quantitative comparisons indicate that the striking similarity can be found between the true and simulated true images in terms of the visual looks and the statistical analysis.

• 대한한방소아과학회지
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• 제25권2호
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• pp.111-120
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• 2011

Objectives: The purpose of this study is to estimate genetic and environmental factors, which can affect Idiopathic true Precocious puberty, and to evaluate the clinical and endocrinologic characteristics. Methods: Retrospective and Comparative analysis of 76 children (72 girls and 4 boys) has been diagnosed with idiopathic true precocious puberty, and treated with GnRHa from December 2008 to July 2011. Results: 1. The Average chronological age (CA. yr) of children diagnosed with idiopathic true precocious puberty was $8.40{\pm}0.81$ (girls), $9.93{\pm}0.12$ (boys). 2. The Average height & weight percentile (%ile) of the girls diagnosed with idiopathic true precocious puberty was $67.38{\pm}22.04$, $67.69{\pm}23.20$. 3. The girls' mothers have diagnosed with idiopathic true precocious puberty, and they were shorter than the average. This shows that mother's small height and idiopathic true precocious puberty are closely related to each other. 4. BMI percentile (%ile) of girls diagnosed with idiopathic true precocious puberty was $63.26{\pm}24.86$. 23.6% of children were diagnosed with overweight or obesity. This result shows that obesity and idiopathic true precocious puberty are proportionally related. 5. Birth weights (kg) of the children diagnosed with idiopathic true precocious puberty were $3.16{\pm}0.43$ (girls), $3.15{\pm}0.38$ (boys). 8.3% of children were diagnosed with Intrauterine growth retardation. 6. The Average bone ages (BA. yr) of the children diagnosed with idiopathic true precocious puberty were $10.51{\pm}0.99$ (girls), $12.10{\pm}0.97$ (boys). The Average BA-CA was $2.11{\pm}0.81$ (girls), $2.00{\pm}0.87$ (boys). 7. The Average predicted adults' height (PAH. cm) of the children diagnosed with idiopathic true precocious puberty was $151.61{\pm}4.00$ (girls), $163.50{\pm}2.15$ (boys). The Average MPH-PAH was $6.84{\pm}4.91$ (girls), $6.00{\pm}5.35$ (boys). 8. 23.6% of the children treated with GnRHa were co-treated with Growth Hormone. Conclusions: Estimated factors which cause Idiopathic true precocious puberty are mother's small height, obesity, and Intrauterine growth retardation. However, the studies of Oriental Medicine for Idiopathic true precocious puberty were lacking. Further clinical and experimental researches are needed.

• Asian-Australasian Journal of Animal Sciences
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• 제4권3호
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• pp.211-218
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• 1991

The effects of dietary fiber on true digestibility of amino acids by growing pigs were studied, using semi-purified diets formulated from alfalfa meal, cassava leaf meal, rubber seed meal and leucacna meal at 20% level. A protein-free diet including 5% cellulose was formulated for correcting the endogenous amino acid loss. Across all the diets, arginine was the most digestible while the least at ileal level was threonine; methionine and/or histidine at fecal level respectively. The true digestibility value of amino acids at ileal level were higher than at fecal level except control diet (cellulose). The true digestibility values at ileal level were similar for all diets but differed at fecal level in different magnitude. These results indicate that undigestible compound in individual feedstuff might confound. True digestibility should be studied together for accurate diet formulation as apparent digestibility decreased when their amino acid concentration in the diet was reduced.

• Current Optics and Photonics
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• 제3권5호
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• pp.408-414
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• 2019

In this paper we propose a method to generate a true color image in scanning white-light interferometry (SWLI). Previously, a true color image was obtained by using a color camera, or an RGB multichannel light source. Here we focused on acquiring a true color image without any hardware changes in basic SWLI, in which a monochrome camera is utilized. A Fourier transform method was used to obtain the spectral intensity distributions of the light reflected from the sample. RGB filtering was applied to the intensity distributions, to determine RGB values from the spectral intensity. Through color corrections, a true color image was generated from the RGB values. The image generated by the proposed method was verified on the basis of the RGB distance and peak signal-to-noise ratio analysis for its effectiveness.

• 한국융합학회논문지
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• 제8권2호
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• pp.253-258
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• 2017

현대사회가 산업화, 도시화, 정보화로 풍요로운 삶과 동시에 기계화와 경쟁화로 인간소외와 스트레스로 인하여 자아상실이 발생하여 부적응 현상들이 많이 나타나고 있다. 발생한 부적응을 적응으로 변화하기 위하여 진실한 자신과 참나와의 만남에 노력을 기울여야 한다. 일상생활에서 진실한 자신 참나와의 만남의 도구로서 차는 좋은 역할을 한다. 따라서 본 연구에서는 차를 진실한 나를 느끼고 이해하기 위하여 다례를 통해서 자신을 존중하고 사랑하는 참나를 만나는 참나다례를 구성하고 대중화를 위하여 표준 웹 프로토콜 기술을 활용한다. 참나다례는 준비단계를 거쳐, 가장 기본적인 다도구를 사용한다. 참나다례는 차와 나를 소통하기 위하여 다도구와 나를 정화하는 단계, 나를 이해하며 차 우리기 단계, 나를 존중하며 차 마시기 단계, 참나를 만나는 단계로 구성되어 있다. 본 논문에서는 참나다례를 구성하고, 표준 웹 프로토콜 기술을 활용하여 참나다례의 대중화를 제안하였다. 표준 웹 프로토콜 기술을 활용하면 이용자의 접근성이 증대되므로 언제 어디서나 참나다례를 접할 수 있다.