• Title/Summary/Keyword: visible wave

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Photovoltaic Effect of the Si-AnSe n-n Heterojunction (Si-ZnSe n-n Heterojunction의 광기전력 효과)

  • 김화택
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.15 no.1
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    • pp.5-11
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    • 1978
  • Si-ZnSe n-n heterojunction was made by growing ZnSe thin film on the Si single crystal (111) surface with Bash evaporating method in vacuum. This heterojunction was found to be a useful device for frequency meter in the visible wave-length from the measuring of the photovoltaic effect of the heterojunction.

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On the Mural Paintings Detectedc by through the Infrared T.V.Camera at Josadang, Busuk Temple (부석사 조사당 벽화조사에 따른 적외선 T.V카메라 이용)

  • Chung, Kwang-Yong
    • 보존과학연구
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    • s.7
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    • pp.218-236
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    • 1986
  • In the fields of the cultural properties, the Infrared TV camera is being initiated to use instead of the Infrared photo film fo a better means to detect the description of drawings of the paintings. Seeing from the effect of transillumination, the Infrared TV camera with its long wave of visible spectrum that makes less absorption by the pigments and with the reflection rays passing through the base of colour layers makes it able to findbase drawing and letters. The detection range of transillumination by the infrared rays depends on the kinds of pigments, lines of the base drawing and wave length of the infrared rays. In our country, it was the first time to detect by our Conservation Science Dep't of The Research Institute of Cultural Properties by means of using Infrared TV camera to determine the mural paintings on the Josadang, Busuk Temple, resulted in an epoch-making success, that we have come to know the painting technique methods, how to treat for its conservation and making replica, reproduction, etc.

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Optical configurtion and fabriation for a reflective display using an antiferroelectric liquid crystal cell (AFLC 셀을 이용한 반사형 LCD의 설계 및 제작)

  • 김성철;박원상;이서헌;황용석;이기동;윤태훈;김재창
    • Korean Journal of Optics and Photonics
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    • v.12 no.3
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    • pp.235-239
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    • 2001
  • In this paper, we propose an optical configuration of a reflective AFLC display mode using a half-wave AFLC cell in which inplane tilt angle is $22.5^{\circ}C$. To check the validity of our design, we fabricate a reflective half-wave AFLC cell of which the in-plane tilt angle is $24.9^{\circ}C$, and measure viewing angle and visible spectra characteristics. In the results, the half-wave AFLC cell in the reflective configuration exhibits wide viewing-angle as well as high brightness and contrast. trast.

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Effect of Extracorporeal Shock-wave Therapy on Pain, Grip Strength, and Upper-extremity Function in Patients with Lateral Epicondylitis (체외충격파치료가 팔꿉관절 가쪽위관절염 환자의 통증과 악력 및 팔 기능에 미치는 영향)

  • Song, Min-Jeong;Kang, Tae-Woo;Kim, Beom-Ryong
    • PNF and Movement
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    • v.18 no.1
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    • pp.117-126
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    • 2020
  • Purpose: The purpose of this study was to investigate the effects of extracorporeal shock-wave therapy (ESWT) on pain, grip strength, and upper-extremity function in patients diagnosed with lateral epicondylitis and to provide an effective intervention method for lateral epicondylitis. Methods: Twenty patients with lateral epicondylitis were randomly assigned to the ESWT group (n = 10) and the stretching exercise group (n = 10). Interventions in both groups were performed six times twice a week for three weeks. The visible analog scale (VAS) was used to measure pain change. A dynamometer was used to measure grip strength (GS). Patient-rated tennis elbow evaluation (PRTEE) was used to measure the upper-extremity function. Results: There were significant differences in pain, grip strength, and upper-extremity function in both groups before and after intervention (p < 0.05). There were also significant differences in pain, grip strength, and upper-extremity function between the groups after intervention (p < 0.05). Conclusion: This study showed very positive improvement in pain, grip strength, and upper-extremity function after ESWT in patients with lateral epicondylitis. Therefore, ESWT can be recommended for patients with lateral epicondylitis.

Terahertz Imaging Technology and Applications (테라헤르츠 이미징 기술 및 그 응용 분야)

  • Kim, M.G.;Lee, E.S.;Park, D.W.;Choi, D.H.;Lee, I.M.;Shin, J.H.;Kim, Y.H.;Kim, J.S.;Cho, J.C.;Kim, Y.H.;Kwak, D.Y.;Park, K.H.
    • Electronics and Telecommunications Trends
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    • v.36 no.3
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    • pp.97-105
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    • 2021
  • The terahertz wave (THz wave) is a band between infrared and microwaves and is defined as an electromagnetic wave having a frequency of 0.1 to 10 THz band. THz waves have the property of transmitting nonpolar materials, which the visible light cannot be transmitted, such as ceramics, plastics, and paper; and the photon energy is low, such as several meV. For this reason, non-destructive testing equipment based on THz imaging technology can be applied to the industrial field. Recently, THz imaging technology was applied in wide industrial fields, such as automobiles, batteries, food, medical, and security, and being actively studied. In this paper, we describe the research trends of terahertz imaging technology and experimental results. Furthermore, we summarize the recent commercialized terahertz camera. Finally, we present the research results in the field of the human security scanner system.

Short-Wave Infrared Fluorescence-Guided Surgery Using Indocyanine Green in a Dog with a Cutaneous Mast Cell Tumor

  • Su-Hyeon Kim;Sungin Lee
    • Journal of Veterinary Clinics
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    • v.39 no.6
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    • pp.395-399
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    • 2022
  • A 6-year-old spayed, female golden retriever dog was presented with a skin mass on the dorsal region of the right carpus. The cytology result of the region revealed characteristics of mast cell tumors (MCTs). Short wave-infrared fluorescence-guided surgery using Indocyanine green (ICG) was performed to determine the surgical margin of the tumor. ICG was injected intravenously 24 hours before the surgery and the patient was hospitalized and carefully monitored. During the surgery, ICG fluorescence-based surgery was performed to identify the tumor and the surgical margin. The tumor was visible, and the skin mass was resected using NIR device for the guidance of the surgical margin of the tumor. Once the resection was complete, the surgical site was again inspected with SWIR fluorescence imaging to identify residual tumor cells. The resected tumor, using ICG navigation, was classified as low-grade cutaneous MCT and the margin was complete on the histopathological result. We report herein a case of resection of a cutaneous MCT in a dog using SWIR fluorescence imaging ICG which can be potentially used for the identification of tumors and evaluation of the surgical margin for complete resection.

Numerical Analysis of Nonlinear Shoaling Process of Random Waves - Centered on the Evolution of Wave Height Distribution at the Varying Stages of Shoaling Process (불규칙 파랑 비선형 천수 과정 수치해석 - 천수 단계별 파고분포 변화를 중심으로)

  • Kim, Yong Hee;Cho, Yong Jun
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.32 no.2
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    • pp.106-121
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    • 2020
  • In order to make harbor outskirt facilities robust using the reliability-based design, probabilistic models of wave heights at varying stage of shoaling process optimized for Korean sea waves are prerequisite. In this rationale, we numerically simulate the nonlinear shoaling process of random waves over the beach with a sandbar at its foreshore. In doing so, comprehensive numerical models made of spatially filtered Navier-Stokes Eq., LES [Large Eddy Simulation], dynamic Smagorinsky turbulence closure were used. Considering the characteristics of swells observed at the east coast of Korean Peninsula, random waves were simulated using JONSWAP wave spectrum of various peak enhancement coefficients and random phase method. The coefficients of probabilistic models proposed in this study are estimated from the results of frequency analysis of wave crests and its associated trough detected by Wave by Wave Analysis of the time series of numerically simulated free surface displacements based on the threshold crossing method. Numerical results show that Modified Glukhovskiy wave height distribution, the most referred probabilistic models at finite water depth in the literature, over-predicts the occurring probability of relatively large and small wave heights, and under predicts the occurrence rate of waves of moderate heights. On the other hand, probabilistic models developed in this study show vary encouraging agreements. In addition, the discrepancy of the Modified Glukhovskiy distribution from the measured one are most visible over the surf zone, and as a result, the Modified Glukhovskiy distribution should be applied with caution for the reliability-based design of harbor outskirt facilities deployed near the surf-zone.

A Study on Effects of Temperature for Physical Properties Change of rocks (암석의 물리적 특성 변화에 대한 온도의 영향)

  • Kim, Jae-Hwan;Lee, Myeong-Seong;Lee, Mi-Hye;Lee, Jae-Man;Park, Sung-Mi
    • The Journal of the Petrological Society of Korea
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    • v.20 no.3
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    • pp.141-149
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    • 2011
  • Samples (two granites, marble, sandstone) were heated in an electric furnace at temperature $400^{\circ}C$ and $600^{\circ}C$ in order to investigate the change of physical properties of rocks depending on the heating temperature. Changes of Color and physical properties such as specify gravity, porosity, absorption, p-wave velocity are visible while mineralogical changes by using polarizing microscope are not pronounced. In addition, porosity and absorption increased while specific gravity and p-wave velocity decreased at a more higher temperature ($600^{\circ}C$). Although the open porosity does not indicate total porosity of the rock. but p-wave velocity can be used to evaluate the degree of damage Therefore, porosity and p-wave velocity should be compared in order to investigate the change of physical properties of rocks depending on the heating temperature.

Implementation of Optical Sensor based on Block Surface Wave and Diffraction Grating Profile (Block 표면파와 회절 격자구조에 기초한 광학 센서의 구현)

  • Ho, Kwang-Chun
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.21 no.4
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    • pp.143-148
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    • 2021
  • A systematic study of Bloch surface wave (BSW), which is created by guided mode resonance (GMR) of dielectric multilayer structures with a grating profile, is presented to analyze the sensing performance of bio-sensors. The effect of structural parameters on optical behavior is evaluated by using Babinet's principle and modal transmission-line theory. The sensitivity of designed bio-sensors is proportional to the grating constant at wavelength spectrum, and inversely proportional to the normal wave vector of incident electromagnetic wave at angular spectrum. Numerical results for two devices with SiO/SiO2 and TiO2/SiO2 multilayer dielectric stacks are presented, showing that BSW can be exploited for the realization of efficient diffraction-based bio-sensors from infrared to visible-band range.

Estimation of Forest LAI in Close Canopy Situation Using Optical Remote Sensing Data

  • Lee, Kyu-Sung;Kim, Sun-Hwa;Park, Ji-Hoon;Kim, Tae-Geun;Park, Yun-Il;Woo, Chung-Sik
    • Korean Journal of Remote Sensing
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    • v.22 no.5
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    • pp.305-311
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    • 2006
  • Although there have been several attempts to estimate forest LAI using optical remote sensor data, there are still not enough evidences whether the NDVI is effective to estimate forest LAI, particularly in fully closed canopy situation. In this study, we have conducted a simple correlation analysis between LAI and spectral reflectance at two different settings: 1) laboratory spectral measurements on the multiple-layers of leaf samples and 2) Landsat ETM+ reflectance in the close canopy forest stands with fieldmeasured LAI. In both cases, the correlation coefficients between LAI and spectral reflectance were higher in short-wave infrared (SWIR) and visible wavelength regions. Although the near-IR reflectance showed positive correlations with LAI, the correlations strength is weaker than in SWIR and visible region. The higher correlations were found with the spectral reflectance data measured on the simulated vegetation samples than with the ETM+ reflectance on the actual forests. In addition, there was no significant correlation between the forest.LAI and NDVI, in particular when the LAI values were larger than three. The SWIR reflectance may be important factor to improve the potential of optical remote sensor data to estimate forest LAI in close canopy situation.