E . 융어의 기술 형이상학

양우석 한국동서철학회 1998 동서철학연구 Vol.16 No.1

테일러 유동을 이용한 새로운 산화박리 그래핀 제조 및 기능화

양우석 한국공업화학회 2015 한국공업화학회 연구논문 초록집 Vol.2015 No.0

Graphene Oxide (GO)는 2D material 인 그래핀의 표면 및 가장자리에 수산기 와 에폭시기, 카르복실기 등과 같은 oxygen groups이 결합한 형태로 환원 과정을 통해 그래핀으로 쉽게 제작할 수 있다. 이러한 GO는 기존에 modify Hummers method를 이용하여 많이 제작되고 있으나, 이 방법은 원 재료로 사용되는 그라파 이트의 층간 사이에 KMnO4와 같은 산화제를 삽입하는데 시간이 오래 걸리고, 균 일하게 삽입되지 못하는 등 문제점을 갖고 있다. 본 연구에서는 처음으로 GO 제조 시 화학적 박리법과 물리적 박리법을 함께 사용한 Taylor vortex라는 나선형 와류 를 이용하여 그라파이트의 균일한 산화 및 박리를 촉진 시켰으며, 이로 인해 산화 반응시간을 획기적으로 단축시켰다. 또한, 이렇게 만들어진 GO에 테일러 유동을 사용하여 Fe3O4를 쉽게 기능화하였으며, Fe3O4@GO를 이용하여 물속의 중금속 을 제거하는 수처리에 응용하였다.

A Location Problem of Fast Charging Stations Considering Congestion

양우석 인하대학교 정석물류통상연구원 2017 JOURNAL OF INTERNATIONAL LOGISTICS AND TRADE Vol.15 No.3

This paper considers locating congested fast charging stations (FCSs) and deploying chargers in a stochastic environment, while the related studies have predominantly focused on problems in deterministic environments. Reducing the inconvenience caused by congestion at FCSs is an important challenge for FCS service provider. This is the underlying motivation for this study to consider a problem for FCS network design with the congestion restriction in a stochastic environment. We proposed a maximal coverage problem subject to budget constraints and a congestion restriction in order to maximize the demand coverage. With the derivation of the congestion restriction in the considered stochastic environment, the problem is formulated into an integer programming model. A real-life case study is conducted and managerial implications are drawn from its results.

Bluetooth와 Smartphone을 이용한 LED 디밍 시스템 구현

양우석,김혜명,조영식,박대희,Yang, Woo-Seok,Kim, Hye-Myeong,Cho, Young-Seek,Park, Dae-Hee 한국전기전자재료학회 2015 전기전자재료학회논문지 Vol.28 No.1

In this paper, LED lighting system is realized by using Bluetooth wireless communications and smartphones. A bluetooth module with a lighting control function is manufactured by miniaturizing a development board of TI company and the volume of LED dimming system as a whole is reduced. And a trial product is materialized by designing a hardware composed of the manufactured bluetooth module, LED down light equipped with degree warm white and cool white, and 2-channel LED driver; and LED dimming software. The materialized trial product is controled in terms of the brightness and color temperature of LED light source using an application of a smartphone. The experiment showed that the users can easily control the intensity of illumination of LED light source by using the scroll bar of the applications of smartphones. In addition, the color temperatures of both warm white and cool white can be controlled, and when the color temperature of the trial product using the manufactured bluetooth module is compared with that of a trial product of TI company, they show the same color temperatures.

그린솔라잉크 연구단 용액공정 기반 광흡수층 및 투명전극 소재 개발 현황

양우석,문주호 한국태양광발전학회 2017 한국태양광발전학회지 Vol.3 No.2

$\mu$-PD법에 의한 Er : Mg : LiNbO$_3$fiber 결정 성장 및 형광특성

양우석,윤대호 한국결정성장학회 2000 韓國結晶成長學會誌 Vol.10 No.6

본 연구에서는 $\mu$-PD법으로 Er : Mg : $LiNbO_3$화이버 결정을 MgO의 첨가량을 달리하여 성장시켰으며, 첨가물 농도에 따른 성장조건과 PL 특성에 관해 조사하였다. 또한,성장한 결정의 투과 스펙트럼으로부터 Er : Mg : $LiNbO^3$에서 $Er^{3+}$ 의 에너지 준위구조를 계산하였다. Crack과 bubble등의 결함이 없는 결정은 after-beater를 조정하여 0.5 mm/min 이하의 성장속도에서 얻을 수 있었다. MgO의 농도에 따른 PL강도는 0.6 mol% $Er_2O_3$와 3 mol% MgO가 첨가된 Er : Mg : $LiNbO_3$결정에서 가장 강한 형광강도가 관측되었다. 또한, 에너지 준위 $^4S_{3/2}$에서 기저준위로 방출되는 빛이 가장 강했으며 1530 nm의 형광은 비방출천이 및 형광방출 등의 원인에 의한 $^4I_{13/2}$ 준위에서의 여기전자 감소가 형광강도 감소의 원인임을 알 수 있었다. High-quality $Er^{3+}$ doped Mg : $LiNbO_3$single crystal fibers were grown by a micro-pulling down ($\mu$-PD) method. Single crystal fibers were pulled down through the nozzle, at a pulling down rate of 0.5 mm/min and using a Pt crucible with a nozzle 1 mm in diameter in air atmosphere. Defects such as bubbles, cracks and inclusions were not detected in any of the grown crystals. The optical transmission of Er : Mg : $LiNbO_3$crystal was measured and the energy levels of $Er_2O_3$ ion could be calculated. The photoluminescence spectrum of crystal fibers showed an energy band emission with the strongest line corresponding to the $^4I_{3/2}{\to}^4I_{15/2}$transition. The concentration dependence of the entire wavelength region emission intensity upon excitation intensity measured emission intensity for the 3 mol% MgO doped fibers was larger than that for the 1, 5 mol% MgO doped fibers.

태양광-수소 생산을 위한 용액공정 기반 저가 Sb₂Se₃ 광전극 개발 현황

양우석,Yang, U-Seok 한국전기전자재료학회 2021 전기전자재료 Vol.34 No.1

Nuclear factor kappa-B- and activator protein-1-mediated immunostimulatory activity of compound K in monocytes and macrophages

양우석,이영수,김동현,김민호,박재광,김은지,이상열,윤기정,김종훈,박준성,조재열 고려인삼학회 2017 Journal of Ginseng Research Vol.41 No.3

Background: Compound K (CK) is a bioactive derivative of ginsenoside Rb1 in Panax ginseng (Korean ginseng). Its biological and pharmacological activities have been studied in various disease conditions, although its immunomodulatory role in innate immunity mediated by monocytes/macrophages has been poorly understood. In this study, we aimed to elucidate the regulatory role of CK on cellular events mediated by monocytes and macrophages in innate immune responses. Methods: The immunomodulatory role of CK was explored by various immunoassays including cell-cell adhesion, fibronectin adhesion, cell migration, phagocytic uptake, costimulatory molecules, reactive oxygen species production, luciferase activity, and by the measurement of mRNA levels of proinflammatory genes. Results: Compound K induced cell cluster formation through cell-cell adhesion, cell migration, and phagocytic activity, but it suppressed cell-tissue interactions in U937 and RAW264.7 cells. Compound K also upregulated the surface expression of the cell adhesion molecule cluster of differentiation (CD) 43 (CD43) and costimulatory molecules CD69, CD80, and CD86, but it downregulated the expression of monocyte differentiation marker CD82 in RAW264.7 cells. Moreover, CK induced the release of reactive oxygen species and induced messenger RNA expression of proinflammatory genes, inducible nitric oxide synthase, and tumor necrosis factor-alpha by enhancing the nuclear translocation and transcriptional activities of nuclear factor kappa-B and activator protein-1. Conclusion: Our results suggest that CK has an immunomodulatory role in innate immune responses through regulating various cellular events mediated by monocytes and macrophages.

부유식 방파에의 파랑 차단 성능 제어

양우석,조원철,박우선 한국해안해양공학회 2001 한국해안해양공학회 논문집 Vol.13 No.3

본 논문은 2차원 유한요소모델을 이용한 부유식 방파제의 파랑차단특성에 대한 수치적 연구이다. 유체영역은 선형화된 2차원유동으로 가정하고, 부유식 방파제의 성능을 분석하기 위하여 유한요소법을 적용하였다. 상자형 부유식 방파제와 두 개의 상자가 일정한 간격으로 양측 방파제를 대상으로 파랑차단효과 대한 수치해석을 실시하였다. 긴 주기 파랑의 차단효과를 증대시키기 위한 방안 중의 하나로 연직판을 부체 하단에 양측에 부착한 경우에 대한 수치실험을 실시하였다. The numerical investigations on the wave-screening characteristics of floating breakwaters are presented. The fluid motion is idealized as linearized, two dimensional potential flow. A finite element model is adopted to analyze the performance of floating breakwaters. Numerical experiments are carried out for two type floating breakwater. One is a conventional pontoon type breakwater with rectangular cross-section, and the other is a side float breakwater which consists of two rectangular shaped floats connected to each other by a frame. To improve the performance of the floating breakwaters, especially for long-period wave conditions, numerical experiments are carried out for the cases attaching the thin plates at the bottom of folats in the vertical direction.

초고속 광변조기 제작을 위한 LiNbO₃도파로의 건식식각

양우석,김우경,이승태,박우정,장현수,윤대호,이한영 한국전기전자재료학회 2003 전기전자재료학회논문지 Vol.16 No.8

Ti-indiffused LiNbO$_3$waveguide have been used to various high speed optical device based on electro-optic effect such as modulators, switches, and sensor, etc. In order to high speed modulation of optical modulator have, one of the further devices, needed to increasing of electrode surrounding air by LiNbO$_3$dry etching because of impedance matching for optical and RF phase velocity between waveguide and electrode. We studied property of LiNbO$_3$dry etching after waveguide patterning lot optical modulation by using neutral loop discharge (NLD) plasma.