• 한국기계가공학회지
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• 제12권5호
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• pp.16-22
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• 2013

A two-dimensional photonic crystal structure was investigated using a roll-to-roll nanoreplication and physical vapor deposition processes for the inexpensive enhanced fluorescence substrate which is not sensitive to the polarization directions of excitation light source. An 8 inch silicon master having nano dot array with a diameter of 200 nm, a height of 100 nm and a pitch of 400 nm was prepared by KrF laser scanning lithography and reactive ion etching processes. A flexible polymer mold was fabricated by flat type UV replication process and a deposition of 10 nm nickel layer as an anti-adhesion layer. A roll mold was prepared by warping the flexible polymer mold on an aluminum roll base and a roll-to-roll UV replication process was carried out using the roll mold. After the deposition of ~ 100 nm $TiO_2$ layer on the replicated nano dot array, a 2 dimensional photonic crystal structure was realized with a resonance wavelength of 635 nm for both p- and s-polarized light sources.

• 정보저장시스템학회논문집
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• 제2권2호
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• pp.91-95
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• 2006

High-density image sensors rave microlens array to improve photosensitivity. It is conventionally fabricated by reflow process. The reflow process has some weak points. UV imprinting process can be proposed as an alternative process to integrate microlens array on photodiodes. In this study, the UV imprionting process to integrate microlens array on image sensor was developed using UV transparent flexible mold and simulated image sensor substrate. The UV transparent flexible mold was fabricated by replicating master pattern using siliconacrylate photopolymer. The releasing property and shape accuacy of siliconacrylate mold was analysed. After UV imprinting process, replication quality and align accuracy was analysed.

• 정보저장시스템학회:학술대회논문집
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• 정보저장시스템학회 2005년도 추계학술대회 논문집
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• pp.17-21
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• 2005

High-density image sensors have microlens array to improve photosensitivity. It is conventionally fabricated by reflow process. The reflow process has some weak points. UV imprinting process can be proposed as an alternative process to integrate microlens array on photodiodes. In this study, the UV imprionting process to integrate microlens array on image sensor was developed using W transparent flexible mold and simulated image sensor substrate. The UV transparent flexible mold was fabricated by replicating master pattern using siliconacrylate photopolymer. The releasing property and shape accuacy of siliconacrylate mold was analysed. After UV imprinting process, replication quality and align accuracy was analysed.

• 한국동물학회지
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• 제23권4호
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• pp.203-218
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• 1980

DNA회복합성과 염색체이상, 자매염색분체 교환 및 복제억제 현상과의 연관성을 추구하기 위해서 $HF_1$, CHO 및 $HeLa S_3$ 세포를 재료로 자외선 또는 MMS를 처리하기전 또는 후에 ara-C를 처리하여 그 효과를 비교 검토하였다. (1) Ara-C는 자외선 및 MMS에 의한 DNA회복합성을 억제하였으며 이 억제효과는 ara-C를 후 처리한 경우 더욱 현저하였다. (2) Ara-C는 자외선이나 MMS에 의한 염색체 이상율을 증가시켰다. 특히 MMS 처리후 ara-C를 처리한 실험군에서는 염색체이상율이 상승효과를 보였는데 이는 염색분체 절단이 증가된 때문이었다. (3) Ara-C는 염색체이상에서와는 달리 자외선이나 MMS에 의한 자매염색분체 교환율을 증가시키지 않았다. 이는 특히 MMS군에서 전처리한 경우에 뚜렷하였다. (4) Ara-C를 처리하면 DNA합성율이 즉시 감소했다가 회복되었다. 그러나 ara-C와 자외선 EH는 MMS를 복합처리하면 DNA 합성양상이 처음에는 ara-C의 영향처럼 보이다가 뒤에는 자외선 또는 MMS에 의한 반응과 같이 나타났다. 이같은 결과들은 ara-C가 DNA 상해요인이 아님에도 염색체이상 또는 염색체분체교환 유발요인으로 작용함을 나타내며, DNA 회복기작이 염색체이상, 자매염색분체교환 및 복제억제 현상과 직접적인 상관성이 없음을 시사하는 것이다.

• 한국동물학회지
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• 제25권2호
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• pp.55-62
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• 1982

발생 12일째의 계배근세포를 약 7일간 배양하면서 자외선에 의한 절제회복, 광재활성 및 DNA 복제억제율을 조사하여 다음과 같은 결과를 얻었다. 자외선에 의한 절제회복은 계배근세포의 분화정도가 진행됨에 따라 감소하였으며, 이는 특히 자외선의 선량이 높을수록 뚜렷하였다. DNA 합성율은 분화가 진행된 세포일수록 현저히 감소하는 경향이었으며 각 분화단계에 따른 DNA 복제억제 현상은 배양 초기 세포인 경우 자외선 조사후 30분에서 1시간반 사이에서 가장 심하게 나타났고, 배양후기의 세포에서는 이러한 억제현상이 뚜렷하지 않았다. 또 배양 1일째 세포에서 광재활성에 의한 피리미딘 이량체의 감소율은 자외선 조사직후에 현저하였다가 그후 시간의 경과에 따른 차이는 보이지 않았다. 그러나, 절제회복만에 의한 이량체의 감소는 조사후 시간이 지남에 따라 서서히 감소하여 광재활성에 의한 이량체의 감소량과 비슷한 수준으로 접근하였다.

• 자연과학논문집
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• 제9권1호
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• pp.45-52
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• 1997

저농도의 MNNG가 Aspergillus nidulans의 생존도 및 돌연변이 유발에 끼치는 영향을 조사하였다. Nontoxic하고 submutagenic한 농도의 MNNG 선 처리는 높은 농도로 처리 시의 치사율 및 돌연변이 유발을 낮추지 못했다. 이러한 결과는 Aspergillus nidulans에는 MNNG 에 의한 adaptive response가 일어나지 않는다는 것을 시사하고 있다. 발아 과정의 첫 번째 체세포 분열에서, 시간별로 MNNG에 대한 치사율을 조사하고 UV에 의한 생존도와 비교하였다. UV나 MNNG 처리 시 치사율은 S 세포 시기 직전까지 증가하였다가, DNA 복제 시에는 감소함을 나타내었다. MNNG 처리 시는 UV와 달리 G2세포시기에 치사율이 가장 높았다.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2007년도 춘계학술발표대회 및 제12회 신소재 심포지엄
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• pp.38.1-38.1
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• 2007

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2005년도 추계학술대회 논문집
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• pp.79-82
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• 2005

Fresnel lens has number of applications in the optical systems because of its advantages. It is nearly flat lens that has small weight. It is conventionally used in lighthouse beacons, condensing unit of overhead projector and etc. Recently, demands of small size optical systems such as display units, information storage systems, optical detecting units had increased. Conventional manufacturing process of high quality Fresnel lens is direct machining. But it is not suitable for mass production because of high cost and long cycle time. Replication process is more suitable for mass production. But the Fresnel lens has number of sharp blade shape prism. In the replication process, this blade shape causes defects that can affect optical efficiency. In this study, replication process of blade shape pattern that has maximum height of $280{\mu}m$, aspect ratio 1.4 for Fresnel lens application.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 춘계학술대회 논문집
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• pp.1493-1496
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• 2005

In this paper, we describe a simple, precise and low cost method of fabricating PDMS stamp for UV embossing. It is important to improve the replication quality of stamp because the accuracy of fabricated structure is related to that of the stamp in UV embossing. The PDMS stamp has been fabricated by the replica molding technology with ultrasonic vibration to eliminate micro-air bubbles during the fabrication process of PDMS stamp. Also, this fabrication to use ultrasonic vibration promotes PDMS solution to fill into micro channel and edge parts. We report the fabrication of an optical core using UV embossing with fabricated PDMS stamp. This fabricated core is $7\;\mu{m}\;at\;depth,\;6\;\mu{m}\;at\;width.\;This\;measured\;value\;has\;the\;difference\;below\;1\;\mu{m}$compared to the original stamp. The surface roughness of core is about 14 nm root mean square. This is satisfactory value to use low-loss optical waveguide. Our successful demonstration of precise replica technology presents an alternative approach for the stamp of UV embossing.

• 정보저장시스템학회논문집
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• 제6권1호
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• pp.37-40
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• 2010

Fresnel lens is a kind of refractive optical lens with various advantages. It has nearly flat shaped optical lens that has small mass. Fresnel lens has number of applications in the compact optical systems. Recently, demands of high quality Fresnel lens for small size optical systems such as illumination units, compact imaging systems, display units, information storage systems, optical detecting units had increased rapidly. Conventional manufacturing process of high quality Fresnel lens is direct machining. However, it is not suitable for mass production because of high cost and long cycle time. Replication method can provide cost effective mass production process. However, there are various issues about replication of Fresnel lens. Fresnel lens has number of sharp blade shape prism. In the replication process, this blade shape causes defects that can affect optical efficiency. In this study, replication processes; injection molding process and UV imprinting process, were developed and evaluated using Fresnel lens that has maximum pattern height of $250\;{\mu}m$ and aspect ratio of 1.5.