• 한국안광학회지
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• 제10권4호
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• pp.255-259
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• 2005

난시 교정용 콘택트렌즈 착용 시 렌즈의 축 방향을 정확하게 하지 않을 경우이거나, 착용 후 순목 시 안검 등에 의해 콘택트렌즈가 회전할 경우가 있다. 이러한 현상이 있을 경우 완전교정상태가 잘못 교정된 상태로 되기 때문에 안정피로를 유발하여 시력의 저하를 가져올 수 있다. 이런 이유로 콘택트렌즈가 어느 정도 회전했는지의 파악이 필요하다. 콘택트렌즈가 회전했다면 착용 후 굴절검사에서 잔류 난시가 검출될 것이다. 이것을 이용해서 우리는 콘택트렌즈의 회전량을 계산하는 프로그램을 개발하였다.

• 대한치과기공학회지
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• 제34권1호
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• pp.1-9
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• 2012

Purpose: The purpose of this study was to investigate the transmittance differences of pressable ceramic core due to thickness within the visible light spectrum. Methods: 36 specimens were divided into 2 groups (0.6mm, 0.8mm) which have each 3 specimens. The size of specimens was 10mm high and 10mm wide. The transmittance of specimens are measured by spectrophotometer Model Cary 500 that can measure infrared-ray, visible wave and ultraviolet-ray. Results: The results shows that there was no significant difference between specimen's thickness(0.6mm, 0.8mm) and transmittance. Conclusion: The individual's color perception is personal and there are numerous factors that influence on it. In general, human eye can perceive the color of thing only within visible light spectrum but in this experiment through spectrophotometer there was no big difference between specimen's thickness(0.6mm, 0.8mm) and transmittance. To sum up, The most important factors were a layed porcelain structure and its thickness rather than core thickness in the porcelain crown. Also, When making all ceramic core with dead pulp (nervous treatment tooth) when used as a restorative esthetic think is more efficient to improve.

• 통합자연과학논문집
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• 제8권1호
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• pp.60-66
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• 2015

The physical and optical properties of polymers with 2-fluoroaniline and 4-fluoroaniline added, which can be used for hydrophilic ophthalmic lenses, were investigated in this study. The UV-blocking properties of 2- and 4-fluoroaniline were also investigated by measuring their UV transmissibility. 2- and 4-Fluoroaniline were used as additives for the basic combination of HEMA, 5% AA, and 1% MMA, and the materials were copolymerized with EGDMA as the cross-linking agent and AIBN as the initiator. The refractive index, water content, optical transmittance, tensile strength, and contact angle were measured to evaluate the physical properties of the produced hydrogel lens. The measured physical properties of the hydrogel contact lens produced with the copolymerized polymer showed a refractive index of 1.425-1.436; a water content of 36.95-44.65%; a visual light transmittance of 66.0-81.0%; a tensile strength of 0.138-0.281 kgf; and a contact angle of $55.02-57.87^{\circ}$. The UV transmissibility was significantly reduced, which indicates that 2-fluoroaniline and 4-fluoroaniline have UV-blocking properties. This study showed that 2- and 4-fluoroaniline are expected to be used as UV-blocking materials in hydrogel ophthalmic lenses whose physical properties, such as their refractive index and water content, do not change.

• 대한치과기공학회지
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• 제35권1호
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• pp.49-56
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• 2013

Purpose: The deformation characteristics induced by non-destructive stresses using piezoelectric transducer(PZT) were analyzed for 3-unit fixed partial dentures manufactured PFM, Everest(CAD/CAM) and Zirkonzahn(copy milling, MAD/MAM) by electron speckle pattern interferometery(ESPI). Methods: The ESPI analysis after loading the restoration with PZT by applying electric voltage of 900mV at the points of 10 mm above the base of the prostheses. Results: PFM and All-Ceramic Everest prostheses showed about 0.1 ${\mu}m$ while that of All- Ceramic Zirkonzahn prostheses showed 0.085 ${\mu}m$, demonstrating that Zirkonzahn displaced less. For PFM and All-Ceramic Zirkonzahn prostheses, the displacements were large at just below the loading point, while generalize displacement was shown over the loading point and weak connector areas for All-Ceramic Everest prostheses. Conclusion: We could find that the deformation characteristics induced by non-destructive stresses using PZT analyzed by ESPI were similar to the fracture strengths evaluated using universal testing machine.

• 한국임상보건과학회지
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• 제1권3호
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• pp.33-37
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• 2013

Purpose. In this study, we divided elementary school students into two investigated groups. The A group is the lower graders(boys 9, girls 18), and the B group is the higher graders(boys 10, girls 13). The myopia progression has been compared with to each group and it has been investigated for variable terms. Methods. We have analyzed the refraction inspection record of 50 students(boys 19, girls 31) who visited optical shops and more than two times in one year. Results. The subject of study were 50 students(boys 19, girls 31). 1. The distribution of spherical equivalent power with ages : boys A group -2.42D, girls A group -2.53D, boys B group -2.63D, girls B group -2.78D. boys B group -2.63D, girls B group -2.78D. 2. The monthly variation of spherical equivalent power : -0.055D(A), -0.04D(B) in boys, and -0.065D(A), -0.07D(B) in girls. Conclusions. Considering monthly variations and Supposing that the time of changing spectacles degrees were the time of refracting inspection. The result : 3.8 month for A group, 4.5 month for B group in boys, and 3.5 month for A group, 5.2 month for B group in girls.

• 한국재료학회지
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• 제24권12호
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• pp.652-657
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• 2014

The purpose of this study was to investigate the microstructures and mechanical properties of zirconia toughened alumina (ZTA) ceramics prepared from two kinds of 3Y-TZP powders. ZTA composites were prepared by adding two kinds of 3Y-TZP powders, 3YEH (BET = $7m^2/g$) and 3YEM (BET = $16m^2/g$), to ${\alpha}$-alumina in the range of 5-25 wt%. It was found that the microstructure photographs of the ZTA composites showed that the average grain size of alumina decreased as the content of zirconia increased. In our present study, specimens containing 3YEM zirconia exhibited smaller grain sizes compared to those of 3YEH zirconia. The Vickers hardness of the ZTA composites that were sintered at $1600^{\circ}C$ for 2 hrs was found to smoothly decrease with increasing zirconia content because of the low Young modulus in zirconia. The Vickers hardness of the ZTA containing 3YEH zirconia was greater than that of the 3YEM zirconia. In substance, the fracture toughness ($K_{1c}$) of the ZTA composites increased as the content of zirconia increased. The fracture toughness ($K_{1c}$) of ZTA containing 3YEM zirconia was greater than that of 3YEH zirconia.

• 한국산학기술학회논문지
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• 제12권3호
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• pp.1319-1326
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• 2011

상업용 3-D simulation tool(OPERA)을 이용하여 슬릿형 위글러가 장착된 초소형 자유전자레이저 모듈에 있어서 위글러 구조에 따른 전자빔 특성을 조사하였다. 전자렌즈의 중앙 전극에 일정한 potential을 인가하여 전자빔이 평행빔이 되도록 divergence를 줄여서 위글러에 입사시켰으며 위글러의 구조 의존성에 따른 위글러 내부에서의 전기장과 potential 분포를 계산하여 위글러에서의 전자빔 궤적의 변화를 조사하였다.

• 환경생물
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• 제28권4호
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• pp.196-201
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• 2010

The phenethyl ester of caffeic acid (CAPE), an active component of honeybee propolis extract, is shown to inhibit cancer growth previously. However, studies on human ovarian cancer are largely obscure. This study evaluated the effects of CAPE as a potential anti-proliferative and pro-apoptotic agent in the human ovarian cancer line, OVCAR-3. CAPE treated OVCAR-3 cells showed inhibition of cell viability and proliferation in a dose-dependent manner by WST-1 assay, LDH assay and bromodeoxyuridine (BrdU) incorporation assay. Furthermore, CAPE-mediated OVCAR-3 cell growth inhibition was associated with apoptotic changes as evident by cell cycle arrest and accumulation of cells in the apoptotic phase and DNA fragmentation. Taken together, CAPE inhibits cell proliferation via DNA synthesis reduction and induces apoptotic cell death via DNA damage, thus elucidating a novel, plausible mechanism of CAPE anti-tumorigenic property in OVCAR-3 cells.

• 한국안광학회지
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• 제12권3호
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• pp.65-70
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• 2007

본 연구는 전국 2년제 7개 대학 안경광학과의 교육목표 서술 내용과 개설된 교육과정의 교과목을 교양, 전공 필수, 전공 전공 선택 등으로 분류하여 조사 분석하였다. 교육목표는 7개 대학 모두 2년제 대학 교육 목적에 맞는 전문 직업인 양성이었으며, 목표 서술 내용은 대학 교육을 통해 달성 가능한 내용으로 조사되었다. 교육과정은 7개 대학 모두 안경사 국가 면허 시험 과목으로 개설되어 있으나, 검안학 교과목의 굴절검사, 안기능검사와 교양교과목의 직업의식, 조직 내 리더십, 마케팅 관련 교과목의 편성이 더 요구되고, 임상 현장실습 교육은 전문직업인이 되기 위한 경험으로 모든 대학은 교과목으로 개설할 필요성이 있다.

• 한국안광학회지
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• 제12권3호
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• pp.59-63
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• 2007

본 연구의 목적은 유아기 부모를 위한 안보건교육프로그램 개발을 위한 기초연구로서 어머니들이 가지고 있는 안보건관련 지식 정도를 파악하는 것이다. 경기도 수원시 소재 유아교육기관 2곳에 다니고 있는 유아의 어머니 139명을 대상으로 연구자들이 개발한 질문지를 이용하여 조사 연구한 결과, 어머니들의 안보건관련 지식은 연령, 학력, 직업유무에 따른 차이는 없었다. 어머니들의 안보건관련 지식 정도는 높은 편이었지만 지식 정도에 편차가 컸다. 따라서 유아기 부모를 대상으로 심도있고 체계적인 눈 건강 교육프로그램이 개발되고 실시되어야 하며 유아의 시력보호를 위한 다양한 정보나 구체적인 교육내용, 방법을 제시한 실제적인 안보건교육프로그램이 부모들에게 제공됨으로써 자녀의 시력보호를 위한 올바른 개념을 형성하고 실천할 수 있도록 해야 한다.