• Title/Summary/Keyword: light reflection

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Morphological Characteristics of Ginseng Leaves in High-Temperature Injury Resistant and Susceptible Lines of Panax ginseng Meyer

  • Lee, Joon-Soo;Lee, Kyung-Hwan;Lee, Sung-Sik;Kim, Eun-Soo;Ahn, In-Ok;In, Jun-Gyo
    • Journal of Ginseng Research
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    • v.35 no.4
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    • pp.449-456
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    • 2011
  • Plant leaf cuticle is related to the prevention of moisture loss, transpiration, and diffusion of light reflection. The purpose of this study was to examine the morphological characteristics of ginseng leaves in ginseng plants resistant and susceptible to hightemperature injury (HTI) to be related with the leaf-burning. For the HTI resistant lines Yunpoong, high-temperature injury resistance (HTIR) 1, HTIR 2, and HTIR 3, and the HTI-susceptible line Chunpoong, the cuticle densities were 53.0%, 46.2%, 44.9%, 48.0%, and 17.0%; the adaxial leaf cuticle layers were 141.3, 119.7, 119.7, 159.4, and 85.0 nm in thickness; the abaxial leaf cuticle layers were 153.6, 165.8, 157.9, 199.6, and 119.4 nm in thickness; and the stomtal lengths were 21.7, 32.4, 29.4, 30.9, and $21.8{\mu}m$, respectively. All of these aspects suggest that HTI resistant lines have higher cuticle density, thickicker adaxial and abaxial leaf cuticle layers, and longer of stomta length than the HTI-susceptible line, protecting leaves from moisture loss and excessive transpiration under high temperatures to be resistant against the leaf-burning.

Thermal Transfer Pixel Patterning by Using an Infrared Lamp Source for Organic LED Display (유기 발광 소자 디스플레이를 위한 적외선 램프 소스를 활용한 열 전사 픽셀 패터닝)

  • Bae, Hyeong Woo;Jang, Youngchan;An, Myungchan;Park, Gyeongtae;Lee, Donggu
    • Journal of Sensor Science and Technology
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    • v.29 no.1
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    • pp.27-32
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    • 2020
  • This study proposes a pixel-patterning method for organic light-emitting diodes (OLEDs) based on thermal transfer. An infrared lamp was introduced as a heat source, and glass type donor element, which absorbs infrared and generates heat and then transfers the organic layer to the substrate, was designed to selectively sublimate the organic material. A 200 nm-thick layer of molybdenum (Mo) was used as the lightto-heat conversion (LTHC) layer, and a 300 nm-thick layer of patterned silicon dioxide (SiO2), featuring a low heat-transfer coefficient, was formed on top of the LTHC layer to selectively block heat transfer. To prevent the thermal oxidation and diffusion of the LTHC material, a 100 nm-thick layer of silicon nitride (SiNx) was coated on the material. The fabricated donor glass exhibited appropriate temperature-increment property until 249 ℃, which is enough to evaporate the organic materials. The alpha-step thickness profiler and X-ray reflection (XRR) analysis revealed that the thickness of the transferred film decreased with increase in film density. In the patterning test, we achieved a 100 ㎛-long line and dot pattern with a high transfer accuracy and a mean deviation of ± 4.49 ㎛. By using the thermal-transfer process, we also fabricated a red phosphorescent device to confirm that the emissive layer was transferred well without the separation of the host and the dopant owing to a difference in their evaporation temperatures. Consequently, its efficiency suffered a minor decline owing to the oxidation of the material caused by the poor vacuum pressure of the process chamber; however, it exhibited an identical color property.

A Parallel Mode Confocal System using a Micro-Lens and Pinhole Array in a Dual Microscope Configuration (이중 현미경 구조를 이용한 마이크로 렌즈 및 핀홀 어레이 기반 병렬 공초점 시스템)

  • Bae, Sang Woo;Kim, Min Young;Ko, Kuk Won;Koh, Kyung Chul
    • Journal of Institute of Control, Robotics and Systems
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    • v.19 no.11
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    • pp.979-983
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    • 2013
  • The three-dimensional measurement method of confocal systems is a spot scanning method which has a high resolution and good illumination efficiency. However, conventional confocal systems had a weak point in that it has to perform XY axis scanning to achieve FOV (Field of View) vision through spot scanning. There are some methods to improve this problem involving the use of a galvano mirror [1], pin-hole array, etc. Therefore, in this paper we propose a method to improve a parallel mode confocal system using a micro-lens and pin-hole array in a dual microscope configuration. We made an area scan possible by using a combination MLA (Micro Lens Array) and pin-hole array, and used an objective lens to improve the light transmittance and signal-to-noise ratio. Additionally, we made it possible to change the objective lens so that it is possible to select a lens considering the reflection characteristic of the measuring object and proper magnification. We did an experiment using 5X, 2.3X objective lens, and did a calibration of height using a VLSI calibration target.

Analysis of the Meaning of Reminiscence in Korean Elderly : by analysing Korean Novel Literature (노인 회상의 의미 분석연구 : 근대 이후 한국소설의 분석을 중심으로)

  • Lee Eun-Jeong
    • The Journal of Korean Academic Society of Nursing Education
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    • v.4 no.1
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    • pp.38-52
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    • 1998
  • The aim of this study is to analyze the meaning of Korean elders' reminiscences by analysing korean novel literature from 1930s to 1990s. The results of this study are as follows : The moaning of elders' reminiscences are the reflecting on their life, conquesting the excessive fondness the regrecting, the pursuiting of the powers, the pursuiting of the love(Jeong) and the conformation of their exsistence. Elders have tried to examine their life through reflection on their life tha? they did not live good life as son and daughter for parents and as parents for children and that they have foolishly lived, on dream that they did not come true, on their learning that they did not unsatisfied. But elders conquest the excessive fondness. They have felt their limitations of power in the conflict of human relation, the economic matter and the difficult predicament, and have finally accepted their life as it is by conquesting from their tenacity. It is dynamically found that both the reflecting on their life and conquesting of the excessive fondness. And they pursuit the powers. It means the pursuit of the vital powers, the vigorous powers and the competency, Elders have pursuited their vitality, vigor and competency through their reminiscences and have wanted to be recognized by others as a powerful being. These have dynamic and compounded aspects. Elders have pursuited the purely love (Jeong) through their reminiscence togather with their sisters and brothers. And the confirmation of their exsistence refer to through their own situation of health, condition, children, neighbourhood and doing their duty as a human. Elders have confirmed the present value of their being through the reflecting the present, past self, other men around themselves, children, neighborhood and the doing their human duty as a good men. Therefore the results of this study can offer new view on the elders' reminiscences that we have to understand them as a process as what they are, escaping from the simple logic that elders' reminiscence have a positive or a negative effects. Also, this study which have examined the natures of Korean elders' reminiscences can cast a new light on elders' nursing proper for Korean culture.

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A Study on Aerial Perspective on Painterly Rendering (회화적 렌더링에서의 대기원근법의 표현에 관한 연구)

  • Jang, Jae-Ni;Ryoo, Seung-Taek;Seo, Sang-Hyun;Lee, Ho-Chang;Yoon, Kyung-Hyun
    • Journal of Korea Multimedia Society
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    • v.13 no.10
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    • pp.1474-1486
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    • 2010
  • In this paper, we propose an algorithm which represents the distance depiction technique of real painting that named "Aerial Perspective" in painterly rendering. It is a painting technique that depicts the attenuations of light in the atmosphere, and the scattering effect is changed by the distance, altitude and density of atmospheres. For the reflection of these natures, we use the depth information corresponding to an input image and user-defined parameters, so that user changes the effect level. We calculate the distance and altitude of every pixel with the depth information and parameters about shot information, and control the scattering effects by expression parameters. Additionally, we accentuate the occluding edges detected by the depth information to clarify the sense of distance between fore and back-ground. We apply our algorithm on various landscape scenes, and generate the distance-emphasized results compared to existing works.

Implementation of a Robust Visual Surveillance System for the Variation of Illumination Lights (조명광 변화에 강인한 영상 감시시스템 구현)

  • Jung, Yong-Bae;Kim, Jung-Hyeon;Kim, Tae-Hyo
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.10 no.3
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    • pp.517-525
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    • 2006
  • In this paper, the algorithm which improve the efficiency of surveillance in spite of the change of light is proposed and confirmed by virtue of the experiments. One of the problems for the implementation of visual surveillance system is the image processing technique to overcome with the variations of illumination lights. Some conventional systems are generally not considered the error due to the change of lights because the system use at indoor. In practical, the factors of bad image can be classified to the ghosts due to the reflection of lights and shadows in a scene. Especially weak images and noises at night are decreased the performance of visual surveillance system. In the paper, the filter which improve the images with some change of illumination lights is designed and the gabor filter is used for recognition and tracking of the moving objects. In the results, the system showed that the recognition and tracking were obtained $92\sim100%$ of recognition rate at daytime, but $80\sim90%$ of nighttime.

Electrical, Electronic Structure and Optical Properties of Undoped and Na-doped NiO Thin Films

  • Denny, Yus Rama;Lee, Kangil;Seo, Soonjoo;Oh, Suhk Kun;Kang, Hee Jae;Yang, Dong-Seok
    • Proceedings of the Korean Vacuum Society Conference
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    • 2014.02a
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    • pp.193.1-193.1
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    • 2014
  • This study was to investigate the electronic structure and optical properties of Na doped into NiO thin film using XPS and REELS. The films were grown by electron beam evaporation with varying the annealing temperature. The relationship between the electrical characteristics with the local structure of NiO thin films was also discussed. The x-ray photoelectron results showed that the Ni 2p spectra for all films consist of Ni 2p3/2 which indicate the presence of Ni-O bond from NiO phase and for the annealed film at temperature above $200^{\circ}C$ shows the coexist Ni oxide and Ni metal phase. The reflection electron energy loss spectroscopy spectra showed that the band gaps of the NiO thin films were slightly decreased with Na-doped into films. The Na-doped NiO showed relatively low resistivity compared to the undoped NiO thin films. In addition, the Na-doped NiO thin films deposited at room temperature showed the best properties, such as a p-type semiconducting with low electrical resistivity of $11.57{\Omega}.cm$ and high optical transmittance of ~80% in the visible light region. These results indicate that the Na doping followed by annealing process plays a crucial in enhancing the electrical and optical properties of NiO thin films. We believe that our results can be a good guide for those growing NiO thin films with the purpose of device applications, which require deposited at room temperature.

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Optical Properties of VO2 Thin Film Deposited on F:SnO2 Substrate for Smart Window Application (스마트윈도우 응용을 위한 FTO 기판 위에 증착된 VO2 박막의 광학적 특성)

  • Kang, So Hee;Han, Seung Ho;Park, Seung Jun;Kim, Hyeongkeun;Yang, Woo Seok
    • Korean Journal of Materials Research
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    • v.23 no.4
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    • pp.215-218
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    • 2013
  • Vanadium dioxide ($VO_2$) is an attractive material for smart window applications where the transmittance of light can be automatically modulated from a transparent state to an opaque state at the critical temperature of ${\sim}68^{\circ}C$. Meanwhile, F : $SnO_2$ (F-doped $SnO_2$, FTO) glass is a transparent conductive oxide material that is widely used in solar-energy-related applications because of its excellent optical and electrical properties. Relatively high transmittance and low emissivity have been obtained for FTO-coated glasses. Tunable transmittance corresponding to ambient temperature and low emissivity can be expected from $VO_2$ films deposited onto FTO glasses. In this study, FTO glasses were applied for the deposition of $VO_2$ thin films by pulsed DC magnetron sputtering. $VO_2$ thin films were also deposited on a Pyrex substrate for comparison. To decrease the phase transition temperature of $VO_2$, tungsten-doped $VO_2$ films were also deposited onto FTO glasses. The visible transmittance of $VO_2$/FTO was higher than that of $VO_2$/pyrex due to the increased crystallinity of the $VO_2$ thin film deposited on FTO and decreased interface reflection. Although the solar transmittance modulation of $VO_2$/FTO was lower than that of $VO_2$/pyrex, room temperature solar transmittance of $VO_2$/FTO was lower than that of $VO_2$/pyrex, which is advantageous for reflecting solar heat energy in summer.

Silicon Oil-Based 2-Channel Fiber-Optic Temperature Sensor Using a Subtraction Method (감법을 이용한 실리콘 오일 기반의 2채널 광섬유 온도 센서)

  • Lee, Dong Eun;Yoo, Wook Jae;Shin, Sang Hun;Kim, Mingeon;Song, Young Beom;Kim, Hye Jin;Jang, Kyoung Won;Tack, Gye Rae;Lee, Bongsoo
    • Journal of Sensor Science and Technology
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    • v.25 no.5
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    • pp.344-348
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    • 2016
  • We developed a 2-channel fiber-optic temperature sensor (FOTS) using a temperature sensing probe, a fiber-optic coupler, transmitting optical fiber, and an optical time domain reflectometer (OTDR). The temperature sensing probe is divided into a sensing probe and a reference probe for accurate thermometry. A sensing probe is composed of a silicon oil, a FC terminator, a brass pipe, and a singlemode optical fiber and the structure of a reference probe is identical with that of the sensing probe excluding a silicon oil. In this study, we measured the modified optical powers of the light signals reflected from the temperature sensing probe placed inside of the water with a thermal variation from 5 to $70^{\circ}C$. Although the optical power of the reference probe was constant regardless of the temperature change, the optical power of the sensing probe decreased linearly as the temperature increased. As experimental results, the FOTS using a subtraction method showed a small difference (i.e., hysteresis) in its response due to heating and cooling. The reversibility and reproducibility of the FOTS were also evaluated.

AlN를 도핑시킨 ZnO박막의 전기적 및 광학적 특성

  • Son, Lee-Seul;Kim, Gyeom-Ryong;Lee, Gang-Il;Jang, Jong-Sik;Chae, Hong-Cheol;Gang, Hui-Jae
    • Proceedings of the Korean Vacuum Society Conference
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    • 2011.02a
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    • pp.88-88
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    • 2011
  • ZnO는 직접 천이형 반도체로써, 상온에서 3.4eV에 해당하는 띠틈을 가지고 있다. 뿐만 아니라 60meV의 큰 엑시톤 결합에너지를 가지고 있어 단파장 광전 소자 영역의 LED(Light Emitting Diode)나 LD(Laser Diode)에 널리 사용되고 있다. 하지만 일반적으로 격자틈새 Zn(Zni2+)이온이나 O 빈자리(V02+)이온과 같은 자연적인 도너 이온이 존재하여 n-형 전도성을 나타낸다. 그러므로 ZnO계 LED와 LD의 개발에 있어서 가장 중요한 연구 과제는 재현성 있고 안정된 고농도의 p-형 ZnO박막을 성장시키는 것이다. 하지만, 자기보상효과나 얕은 억셉터 준위, 억셉터의 낮은 용해도로 인하여 어려움을 가지고 있다. 본 연구에서는 고품질의 p-형 ZnO박막을 제작하기 위해 AlN를 도핑시킨 ZnO박막을 RF 마그네트론 스퍼터링 법을 이용하여 Ar과 O2분위기에서 성장시켰다. ZnO와 AlN타겟을 동시에 사용하였으며, ZnO타겟에 걸어준 RF 파워는 80W, AlN타겟에 걸어준 RF 파워는 5~20W로 변화시켰다. 박막의 전기적, 광학적 특성은 XPS (X-ray Photoelectron Spectroscopy), REELS (Reflection Electron Energy Loss Spectroscopy), XRD (X-ray Diffraction), SIMS (Secondary Ion Mass Spectrometry), AES (Auger Electron Spectroscopy), Hall measurement를 이용하여 연구하였다. XPS측정결과, AlN를 도핑시킨 ZnO박막의 Zn2p3/2와 O1s피크는 undoped ZnO박막의 피크보다 낮은 결합에너지에서 측정되었다. 모든 박막이 결정화 되었으며, (002)방향으로 우선적으로 성장된 것을 확인할 수 있었다. 홀 측정 결과, 기판을 $200^{\circ}C$로 가열하면서 성장시킨 박막이 p-형을 나타내었으며, 비저항(Resistivity)이 $5.51{\times}10^{-3}{\Omega}{\cdot}m$, 캐리어 농도(Carrier Concentration)가 $1.96{\times}1018cm^{-3}$, 이동도(Mobility)가 $481cm^2$/Vs이었다. 또한 QUEELS -Simulation에 의한 광학적 특성분석 결과, 가시광선영역에서 투과율이 90%이상으로 투명전자소자로의 응용이 가능하다는 것을 보여주었다.

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