• Title/Summary/Keyword: 제품의 깊이

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A Study on the Application of Stereoscopic Depth Value in VR HMD (VR HMD 기반의 스테레오스코픽 깊이 값 적용 연구)

  • Son, Ho-Jun;Kim, Jung-Ho;Lee, Seung-Hyun;Hamacher, Alaric;Kwon, Soon-Chul
    • Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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    • v.6 no.4
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    • pp.31-40
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    • 2016
  • Recently, technology of Virtual Reality(VR) based on HMD among various kinds of VR implemented products has received widespread attention. Major IT-related companies around the world participated in VR HMD research and development. Therefore, the possibility of the spread of VR HMD has been highly praised. Demands of VR HMD products using Smart Phone has been especially increased so that it is required to create a high quality of VR contents. The purpose of study in this paper is to apply the depth value of stereoscopic to VR HMD. To implement it, we analyzed VR HMD optical system and converted an experimental image to virtual depth caused by binocular disparity based on the result of calculating NPP(Native Pixel Parallax). We produced the image of stereoscopic applied with the value converted and applied to VR HMD. This study is expected to be utilized as a VR content creation field of quantitative data.

Comparison of Forming Force on Forward and Backward Flow Forming for Combustion Chamber (연소기 제작을 위한 전후방 유동성형에서의 성형력 비교)

  • Nam Kyoung-O;Yeom Sung-Ho;Hong Sung-In
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2006.05a
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    • pp.379-382
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    • 2006
  • The flow forming has been used to produce long thin walled tube parts, with reduced forming force and enhanced mechanical and surface quality for a good finished part, compared with other method formed parts. Especially, the flow forming is suitable for making high precision thin walled cylinders, such as rocket motor cases, combustion chamber, hydraulic cylinders and high-pressure vessels and so on. In this paper, finite element analysis of three-roller forward and backward flow forming for combustion chamber is carried out to study efforts of forming depth and feed rate on forming force. The axial and radial forming forces of forward flow forming on several forming depth and feed rate conditions are compared with those of backward flow forming.

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HYDROLYTIC DEGRADATION OF DENIAL COMPOSITE RESINS (수종 치과용 복합레진의 가수분해)

  • Yang, Kyu-Ho;Kim, Jung-Ran
    • Journal of the korean academy of Pediatric Dentistry
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    • v.27 no.2
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    • pp.370-378
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    • 2000
  • The composite restorative resins have their insufficient resistance to wear. The subsurface degradation within the restoration is considered to be associated with wear. The aim of this study was to evaluate the resistance to degradation of six commercial composite resins in an alkaline solution. The brands studied were Clearfil APX(Kuraray), Heliomolar(Vivadent), Surefil(Dentsply), TPH(Dentsply), Tetric Ceram(Vivadent), and Z100(3M). Preweighed discs of each brand were exposed 0.1N NaOH solution at $60^{\circ}C$. After 14 days they were removed, neutralized with HCL, washed with water and dried to constant mass at $60^{\circ}C$. Resistance to degradation was evaluated on the basis of the following parameters: (a) mass loss(%) - determined from pre-and post-exposure specimen weights; (b) Si loss (ppm)-obtained from ICP-AE analysis of solution exposed to specimens; and (c) degradation depth$({\mu}m)$ - measured microscopically (SEM) from polished circular sections of exposed specimens. The results were as follows: 1. The mass loss was in descending order by Z100, TC H, S, CL, TPH and in the range of $0.45\sim3.64%$ 2. The degradation layer depth was in descending order by H, Z100, S, TC, TPH, CL and in the range of $10.85\sim73.38{\mu}m$ 3. For the Si concentration, Z100 was the highest of all 4. The highly significant correlation(r=0.81, p<0.05) was observed between mass loss and degradation depth. 5. Under scanning electronmicroscopy, the degradation of connection between resin matrix and fillers was observed 2 weeks after soaking in NaOH solution.

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Electron Beam Welding on Module-typed Turbine Diaphragm (모듈 형 터빈 다이아프람의 전자빔 용접 기술)

  • Kim, Yong-Jai;Shim, Duck-Nam;Jung, In-Chul
    • Proceedings of the KWS Conference
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    • 2009.11a
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    • pp.107-107
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    • 2009
  • 모듈 형 터빈 다이아프람은, 아우터 링(outer ring), 스팀 패스(steam path)와 이너 웹(inner web)의 원형 형상을 갖는 세 부분을 조립하여 원주 방향의 용접 조인트를 형성하는 기존의 다이아프람 형태가 아니라, 아우터 슈라우드(outer shroud), 베인(vane)과 이너 슈라우드(inner shroud)의 세 부분이 하나의 모듈을 이루고 이러한 모듈을 원주 방향으로 조립하여 방사 방향의 조인트를 형성한다. 전자빔 용접은 이와 같은 방사 방향의 조인트를 수직으로 가로지르는 용접 궤적을 따라 진행되며, 용접 패스에 따라 형성되는 용융 비드의 단면적만큼 인접하는 두 모듈을 접합시킨다. 이 경우 용융 비드의 단면적과 형상은 두 모듈의 결합 강도를 결정하는 중요한 요소가 되어, 제작 시 다이아프람의 크기와 두께에 따라 용입 깊이와 평균 단면 비드 폭을 규정하고 있다. 본 연구에서는 용입 깊이와 단면 비드 폭의 요구 조건을 만족하면서 결함이 없는 건전한 용접부를 얻을 수 있는 최적 용접 조건을 도출하는데 그 목적이 있다. 이를 위해 플레이트 시편과 모듈 시편을 사용한 기초 실험과 유사 시제품(semi-mockup) 실험을 실시하였다. 플레이트 기초 실험을 통해 전자빔 주요 변수인 빔 전류, 초점 위치, 용접 속도, 빔 진동 폭 변화에 따른 용융 비드 형상 변화를 관찰하였고, 빔 전류가 용입 깊이에 가장 큰 영향을 주는 인자임을 확인하여 요구 용입 깊이 별 적정 빔 전류 값을 설정하였다. 용접 속도는 생산성 측면에서 균열이 발생하지 않는 범위에서 가능하면 가장 큰 값을 사용하였고, 빔 진동 폭은 초점 위치와 함께 단면 비드 형상 결정에 많은 영향을 주는 인자로 확인되어 균열이 없는 가장 이상적인 단면 비드 형상인 완만한 쐐기 형태가 되도록 설정하였다. 이 후 실제 제품 폭과 용접 패스를 갖는 블록 모듈 실험을 통해 설정 용접 변수의 적용성과 균열 발생 여부를 확인하였고, 이 때 적용 제품 폭이 30 mm 이하이며 요구 용입 깊이가 50 mm 이상의 경우에서 비드 중앙부 균열이 발생함을 관찰하였다. 따라서 해당 영역의 제품에는 균열 저항성이 높도록 용접 속도와 빔 진동 폭을 줄여 최적 용접 변수를 새롭게 설정하였으며, 이를 유사 시제품 실험에 적용하여 최종적으로 용접 변수 안정성을 검증하였다. 이러한 실험을 통해 확인된 최적 용접 조건을 실 제품 제작에 적용하여 모듈 형 터빈 다이아프람 전자빔 용접 제작을 성공적으로 완료할 수 있었다.

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ABRASION AND CHEMICAL DEGRADATION OF LIGHT-CURED COMPOSITE RESIN FOR UPDATED RESIN DEVELOPMENT (차세대 레진개발을 위한 광중합형 복합레진의 마모와 화학적 분해)

  • Yang, Kyu-Ho;Choi, Nam-Ki;Yook, Geun-Young
    • Journal of the korean academy of Pediatric Dentistry
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    • v.31 no.4
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    • pp.685-695
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    • 2004
  • The aim of this study was to evaluate the resistance to degradation and to compare the wear resistance characteristics of four composite resins in an alkaline solution. The resistance to degradation was evaluated on the basis of mass loss(%), degradation depth(${\mu}m$), Si loss(ppm) and wear depth. The brands studied were Heliomolar flow, Filtek supreme, Point4, Tetric flow. The results were as follows: 1. The sequence of the mass loss was in descending order by Heliomolar flow, Filtek supreme, Point4, Tetric flow. There was significant differences among the materials except Heliomolar flow and Filtek supreme. 2. The sequence of the degree of degradation layer depth was in descending order by Filtek supreme, Heliomolar flow, Tetric flow, Point4. There were significant differences among the materials except Heliomolar flow and Tetric flow. 3. The sequence of Si loss was in descending order by Filtek supreme, Heliomolar flow, Point4, Tetric flow. There were significant differences among the materials except Point 4 and Tetric flow. 4. The sequence of maximum wear depth was in descending order by Heliomolar flow, Point4, Fillet supreme, Tetric flow and there was increasing wear depth on soaking in 0.1N NaOH solution. 5. When observed with SEM, destruction of bonding between matrix and filler was observed and when observed with CLSM, the depth of degradation layer of specimen surface was observed. There results indicate that wear and hydrolytic degradation could be considered to be evaluation factors of composite resins.

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AN EVALUATION OF CHEMICAL DEGRADATION OF LIGHT-CURED RESTORATIVE COMPOSITES (광중합 복합레진의 화학적 분해 평가)

  • Yang, Kuy-Ho;Kim, Hun-Ju;Choi, Nam-Ki
    • Journal of the korean academy of Pediatric Dentistry
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    • v.30 no.3
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    • pp.530-539
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    • 2003
  • The aim of this study was to evaluate the resistance to degradation of four commercial composite resins in an alkaline solution. The brands studied were Charisma, Filtek P 60, Palpique Estelite, and Spectrum. Preweighed discs of each brand were exposed to 0.1N NaOH solution at $60^{\circ}C$. After 2 weeks they were removed, neutralized with HCl, washed with water and dried. Resistance to degradation was evaluated on the basis of following parameters: (a) mass loss(%) - determined from pre-and post-exposed specimen weights; (b) Si loss(ppm) - obtained from ICP-AE analysis of solution exposed to specimens; and (c) degradation depth(${\mu}m$) - measured SEM and CLSM from polished circular sections of exposed specimens. The results were as follows: 1. The sequence of mass loss was in descending order by Palpique Estelite, Filtek P 60, Charisma, and Spectrum. 2. The sequence of the degree of degradation layer depth was in descending order by Filtek P 60, Charisma, Palpique Estelita, and Spectrum. 3. The sequence of the Si loss was in descending order by Chrisma, Spectrum, Palpique Estelite, and Filtek P 60. 4. The correlation coefficient between mass loss and degradation layer depth was relatively high(r=0.704, p<0.05). 5. When observed with SEM, destruction of bonding was observed between resin matrix and filler. 6. When observed with CLSM, degradation layer depth of composite resin surface was observed.

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CHEMICAL DEGRADATION AND WEAR OF LIGHT-CURED COMPOSITE RESINS (광중합형 복합레진의 화학적 분해와 마모에 관한 연구)

  • Yang, Kyu-Ho;Jung, Hee-Kyung;Choi, Nam-Ki;Kim, Seon-Mi
    • Journal of the korean academy of Pediatric Dentistry
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    • v.34 no.2
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    • pp.273-284
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    • 2007
  • The aim of this study was to evaluate the resistance to degradation and to compare the wear resistance characteristics of four esthetic restorative materials in an alkaline solution(0.1N NaOH). The composite resins studied were Composan LCM flow(Promedica, Germany). Clearfil ST(Kuraray medical, Japan), Durafi VS1(Heraeus Kulzer, U.S.A), Point 4(Kerr, U.S.A). The results were as follows : 1. The mass loss of each brand was $1.02{\sim}6.04%$ and highest value in Durafil VS$(6.04{\pm}0.29%)$. 2. The sequence of the degree of degradation layer depth was in descending order by Durafil VS, Clearfil ST, Point 4 and Composan LCM flow. There were significant differences between Point 4, Composan LCM flow and the others (p<0.001). 3. The sequence of the Si loss was in descending order by Clearfil ST, Durafil VS, Composan LCM flow and Point 4. There were significant differences among the materials (p<0.001). 4. On SEM, destruction of bonding between matrix and filler and on CLSM, the depth of degradation layer of specimen surface was observed. 5. The sequence of maximum wear depth was in descending order by Durafil VS, Composan LCM flow, Point 4 and Clearfil ST. There were no significant differences among the materials (p>0.001) 6. The correlation coefficient between Si loss and degradation layer depth (r=0.892, p<0.01) and Si loss and mass loss(r=0.736, p<0.01) were relatively high. These results indicate that hydrolytic degradation, wear and another factor may consider as evaluation factors of composite resins.

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인터넷쇼핑몰의 머천다이징만족 결정요인에 관한 연구

  • Jang, Yeong-Il;Hong, Jun-Seok;Yu, Seong-Jin
    • Journal of Global Scholars of Marketing Science
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    • v.6
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    • pp.281-296
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    • 2000
  • 인터넷쇼핑몰은 전통적 유통경로에 비해 많은 장점을 지니고 있음에도 많은 네티즌 (Netizen)들올 만족시키지 못하고 있는데 그 이유중 하나는 머천다이징 전략의 실패에 기인 한다 인터넷쇼핑올 운영자률은 어떤 종류의 제품 서비스들이 인터넷쇼핑몰 판매에 적합 한가에 대한 많은 관심을 가지고 있지만 여기에 대한 기존의 연구가 부족한 실정이다. 본 연구에서는 인터넷쇼핑몰의 만족 결정요인 가운데 하나인 머천다이징 만족에 영향을 미치는 요인들에 대하여 알아보았다. 실종연구 결과는 다음과 같다. 먼저, 제품믹스의 깊이는 머천다이징에 대한 만족에 영향을 주지만, 폭은 영향이 없는 것으 로 나타났으며, 머천다이징에서 '비트-기초 제품'의 비중이 높을수록 그리고 제품의 탐색성이 높올수록 머천다이징에 대한 만족이 높은 것으로 나타났다. 또한 제품이미지나 명성이 높을수 록 그러고 정보가 풍부한 제품일수록 머천다이징 만족이 높은 것으로 나타났다.

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CHEMICAL DEGRADATION OF VARIOUS COMPOMERS IN NaOH (콤포머의 NaOH 용액 내에서의 화학적 분해)

  • Park, Mi-Ran;Choi, Nam-Ki;Lee, Young-Jun;Kim, Seon-Mi;Yang, Kyu-Ho
    • Journal of the korean academy of Pediatric Dentistry
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    • v.31 no.2
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    • pp.144-152
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    • 2004
  • The aim of this study was to evaluate the resistance to degradation of three commercial compomers in an alkaline solution. Dyract(Dentsply), Elan(Kerr) and F-2000(3M) polyacid modified resin composites(compomers) were used in this study. The resistance to degradation was evaluated on the basis of mass loss(%), degradation $depth({\mu}m)$ and Si, Al, Ba loss(ppm). The results were as follows : 1. The mass loss of each brand was $1.42%{\sim}2.14%$ and there was no statistically significant difference of mass loss among Dyract, F2000 and Elan. 2. The degradation layer depth of each brand was $182.92{\sim}227.7{\mu}m$ and there was no statistically significant difference of degradation layer depth among Dyract, F2000 and Elan. 3. There was statistically significant differences in Si-loss and Al-loss among three compomers (p<0.05). Si loss was the highest value in Dyract and Al loss was the highest value in F2000. 4. There was statistically significant correlation between mass loss and degradation layer depth (r=0.60, p<0.05). 5. In SEM finding, there was some destruction of compomer matrix-filler interface in post-exposure specimen to NaOH solution. As the matrix decreased, the filler particles distinguished and the periphery of the filler particles appeared whitish color due to degradation.

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A Study on Conformance Testing Methodology for XML Encryption Products (XML 암호화 제품을 위한 표준 적합성 시험 방법론 연구)

  • Chae, Han-Na;Rhee, Gwang-Soo
    • Proceedings of the Korean Information Science Society Conference
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    • 2005.07a
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    • pp.193-195
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    • 2005
  • 국내의 한 인터넷 경매업체는 "대한민국 국민 5명 중 한명은 이미 자신들의 경매를 경험해 보았다." 라고 광고할 정도로 웹 기반의 전자상거래는 이미 우리의 일상생활에 깊이 파고든 상태이며, 이제는 단순한 웹상의 전자상거래 뿐이 아닌 웹 서비스 개념의 시대가 현실화 되고 있는 시점이다. 이러한 흐름 속에서 XML은 데이터만을 따로 표현할 수 있다는 특성에 의하여 업계의 표준으로 떠올랐으며, 자연스럽게 이와 더불어 XML의 보안기능은 주목을 받고 있다. XML 전자서명, XML 암호화, XML 키 관리 명세는 주요한 XML 보안기술로서 표준화가 진행되어 많은 부분 완료되었다. 이에 따라 표준을 구현한 제품들이 출시되어 상용화되고 있다. 이러한 제품들은 표준에 적합하도록 개발되어야만 제품의 목적인 안정성과 각 제품들 간의 상호운용성에 있어서의 신뢰도를 검증받을 수 있다. 이에 본 논문에서는 XML 암호화에 대한 표준 적합성 시험 방법을 제시하고 시험도구를 구현하였다.

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