• 센서학회지
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• 제21권2호
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• pp.121-126
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• 2012

Piezoresistive type contact force sensor array is fabricated by (111) Silicon bulk micromachining for continuous blood pressure monitoring. Length and width of the unit sensor structure is $200{\mu}m$ and $190{\mu}m$, respectively. The gap between sensing elements is only $10{\mu}m$. To achieve wafer level packaging, the sensor structure is capped by PDMS soft cap using wafer molding and bonding process with $10{\mu}m$ alignment precision. The resistance change over contact force was measured to verify the feasibility of the proposed sensor scheme. The maximum measurement range and resolution is 900 mm Hg and 0.57 mm Hg, respectively.

• 한국안광학회지
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• 제13권3호
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• pp.45-50
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• 2008

목적: 본 연구는 천연항균물질인 나린진을 소프트 콘택트렌즈 수지용액에 첨가하여 소프트 콘택트렌즈를 제조하고, 제조된 콘택트렌즈에서 용출된 용액의 광학적 특성과 나린진의 물리화학적인 상태 그리고 식염수에서의 용출 특성 등에 대해 살펴보고자 하였다. 방법: 나린진이 첨가된 콘택트렌즈는 벌크(bulk)중합 방식을 이용하여 제조하였고, 제조된 나린진이 첨가된 콘택트렌즈에서 나린진의 결합상태와 식염수로의 나린진 용출과정, 그리고 시간에 따른 나린진의 용출량 등은 적외선 스펙트럼(IR spectrum)과 고성능 액체 크로마토그래피(HPLC)를 이용하여 살펴보았다. 결과: 나린진이 첨가된 콘택트렌즈에서 나린진의 용출은 일정농도를 유지하면서 약 1개월 동안 지속되었고, 용출된 나린진은 첨가하기 전과 동일한 구조를 유지하고 있었으며 투과율과 같은 광학적 특성 변화는 관찰할 수 없었다. IR spectrum과 HPLC 결과로부터 콘택트렌즈 내에서 나린진의 구조와 결합상태를 확인하였다. 결론: 나린진이 첨가된 콘택트렌즈에서 나린진은 폴리머 분자와 반데르발스(van der Waals) 인력이나 나린진 분자의 수산기 (hydroxyl group)와 약한 수소결합(hydrogen bonding)에 의해 상호 결합되어 있는 것으로 판단되었다. 나린진이 첨가된 콘택트렌즈로부터 나린진은 약 1개월 동안 일정농도씩 꾸준히 용출되었으며 1개월 후에도 하루 동안 용출된 나린진의 농도가 약 10 ppm으로 나타나 일정기간 동안 항균력의 유지가 지속적으로 필요한 소프트 콘택트렌즈의 제조에 나린진을 첨가하는 방법이 매우 효과적임을 알 수 있었다.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
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• pp.882-885
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• 2006

The contact resistivity of the black interlayer which has been introduced between BUS and ITO electrodes in a plasma display panel was evaluated using two kinds of specially designed test electrode patterns. Of the two, type 2 pattern was able to evaluate the contact resistivity more successfully, which was calculated as about $250{\Omega}$ in the suggested test pattern structure.

• Kyungpook Mathematical Journal
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• 제45권1호
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• pp.55-65
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• 2005

We find the expression of the curvature tensor field for a manifold with is endowed with an almost contact structure satisfying the condition (1.7). By using this condition we obtain some properties of the Ricci tensor and scalar curvature (d. Theorem 3.2 and Proposition 3.2).

• Kyungpook Mathematical Journal
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• 제62권1호
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• pp.179-191
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• 2022

We set our target to investigate Yamabe solitons, gradient Yamabe solitons and gradient Einstein solitons within the structure of 3-dimensional non-cosymplectic normal almost contact metric manifolds. Also, we provide a nontrivial example and validate a result of our paper.

• 센서학회지
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• 제10권4호
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• pp.207-213
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• 2001

A Schottky type GaN ultraviolet photodetector with a mesa structure was fabricated by depositing an Al ohmic contact on an $n^+$-GaN layer and a Pt Schottky contact on a GaN layer. The undoped GaN(0.5um)/$n^-$-GaN(0.1 um)/$n^+$-GaN(1.5 um) multi-layer structure was grown on a sapphire substrate using MOCVD. The Schottky contact properties were characterized for different passivation conditions. The leakage current of the fabricated Schottky diode was 2 nA at a reverse voltage of 5V. Plus the photocurrent was 120uA using a hydrargyrum lamp with an optical power of 1mW at a wavelength of 365 nm. The diode exhibited an ultraviolet-visible rejection ratio of $10^2$.

• 한국정밀공학회지
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• 제29권8호
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• pp.920-926
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• 2012

Wrinkling is a common phenomenon in nature and the shape of a wrinkle can be defined using characteristic dimensions such as pitch, length, amplitude, and density etc. Wrinkle structure can be utilized in various research fields, and especially it has special characteristics when it used in applications of heat transfer; a wrinkly surface has the effect to promote turbulent flow and increasing surface area. However, the generation of wrinkle structures in somewhat regular is not easy. Till now, there are some research works focused on realization of wrinkles in micro scale. However, most of the processes generally requires high precision equipments and high costs, and also there is a limitation to generate the wrinkles in a large area. In this study, we propose a novel method named as a RCO (repetitive contact-and-open) process to fabricate wrinkle structure with low cost and relative easy way. Using the RCO, we fabricated micro-corrugate structures successfully. From the experimental results, we found out the process parameters of RCO, and showed the possibility of RCO to be used in real applications.

• 한국전산구조공학회논문집
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• 제12권3호
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• pp.363-370
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• 1999

본 연구에서는 철근콘크리트기둥과 철골보로 이루어진 혼합구조 접합부의 해석에 대한 유한 유소법을 이용한 해석 모델 방법을 제시하였다. 혼합구조 접합부에서 콘크리트와 강판이 접하는 접촉면은 두 접촉면 사이를 부착과 마찰의 개념으로 표현할 수 있는 주-종속 접촉 알고리즘(master-slave contact algorithm)을 이용하여 모델링하였다. 그리고, 휨응력의 지배를 받는 강관에는 비적합 모드 요소를 사용하였다. 본 연구에서의 혼합구조 특징은 보에서 기둥으로 힘의 전달을 원활히 하기 위하여 다이아프램이 사용되었고, 이러한 혼합구조 접합부 모델링 방법에 대한 타당성을 알아보기 위하여 3차원 비선형 해석을 행하여 실험결과와 비교한 결과 잘 일치하는 결과를 얻었다.

• 한국수소및신에너지학회논문집
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• 제21권4호
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• pp.295-300
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• 2010

Metal bipolar plate applied to Polymer Electrolyte Membrane Fuel Cell is getting most attractive due to their good feasibility of mass production and low cost. But it is one of the immediate causes of performance decline because it is difficult to reduce channel pitch of metal bipolar plate. In this study, mesh was inserted in between bipolar plate and GDL to obtain uniform contact pressure without reducing channel pitch. The section measuring and performance test were carried out to confirm the mesh structure distributes contact pressure equally in reacting area. The performance of 3 type mesh structures developed in this study were higher than the normal cell at all over the current range. Especially, it showed that the mesh cell performance was increased and pressure drop was decreased with diminishing mesh gap size. The Mesh structure was more sensitive to humidification and contact pressure change than the normal cell.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2005년도 춘계학술대회 논문집
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• pp.71-76
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• 2005

The defects evaluation of the interior and the surface would be considered as vital characteristics in predicting the total life span of the steel structure. More importantly, the understandings in the interior composite of welding zone and the notifications in the presence, the formation, and the positioning of the non-metallic inclusion are necessary as well, since there were signs of relatively high defect frequency presented in the welding zone. The ultrasonic testing is a highly recommended technique chosen from among other techniques because of variety of advantages in conducting the non-destructive testing for the welding zone. However, the ultrasonic testing had technical disadvantages referred as followings; the problems due to the couplant between the PZT and the specimen, the formations that were miniature and complex, the moving subject, and the high temperature surrounding the specimen. This research was conducted to resolve the technical disadvantages of the contact ultrasonic testing by studying the non-contact ultrasonic testing where the ultrasonic waves were transferred by the laser, and revealing the specimen defects at its interior part and its surface part. The ultimate goal of this research was to develop a non-destructive evaluation applying the laser manipulated ultrasonic method for the steel structure.