• Title/Summary/Keyword: photo current

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A Study on the Aspect of Space Change to Seokpajeong garden(石坡亭) in the Late Joseon Dynasty (조선후기 원림 석파정(石坡亭)의 공간변화양상에 관한 고찰)

  • Lee, Won-Ho;Kim, Dong-Hyun;Kim, Jae-Ung;Choi, Jong-Hee
    • Journal of the Korean Institute of Traditional Landscape Architecture
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    • v.33 no.1
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    • pp.31-40
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    • 2015
  • This study aims to comprehend that Seokpajeong garden for aspect of space change. Spatial characteristics according to the transfer of ownership are classified as period. And investigate the aspect of space change in Seokpajeong garden based on literature and painting, newspaper, photo. The results were as follows. First, Investigate the construction and change of Seokpajeong garden. Accordingly, spatial characteristics of Seokpajeong garden are classified into three period. 1st period is Kim-Heung Keun owned Samgyedong-jungsa garden. 2nd period is Daewongun hold Seokpajeong garden. 3rd period is damaged original form of Seokpajeong garden from Korean War to current time inclusive. Secondly, Kim-Heung Keun owned Samgyedong-jungsa garden has characteristics of water system centric space and many buildings. In addition accept foreign culture like chinese pavilion and Byeoldang Villa. and plant unique flower and leaf in garden. Thirdly, According to Seokpajeong garden folding screen, Daewongun owned Seokpajeong garden accept organization of space in Samgyedong garden. But different locations of Sarangchae in folding screen means possibility of move building to current position. So, additional historical research is required with representation of chinese pavilion location. Fourthly, Seokpajeong garden was damaged from original form to frequent changes of ownership. Transform of geographical features and water system as well as Anchae and Sarangchae, back side of a outbuilding are only the remained among many buildings. Also, Seokpajeong garden is more fell to the subsidiary facility of Seoul Museum than Wonrim. Therefore restoration and recovery of original form are urgent.

Pattern Analysis of Maximum Power Point by means of Solar Cell Module Array Simulation (태양전지 모듈 어레이 시뮬레이션을 이용한 최대전력점 패턴분석)

  • Jeong, Ji-Won;Park, In-Gyu;Hwang, Kuk-Yeon;Ahn, Tae-Chon
    • Journal of the Korean Institute of Intelligent Systems
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    • v.23 no.1
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    • pp.72-79
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    • 2013
  • In the paper, a pattern analysis to decide whether the 1st local peak power point near open circuit voltage is the global peak power point or not, in case that the voltage and current at the 1st local peak power point are in a specific range, for Maximum Power Point Tracking on the photo voltaic power conversion system. When a solar cell panel array is shaded partially, multi-local peak power points can occur. That makes it hard to search the global peak power point. Through Tableau analysis using by piecewise linear solar cell model, V-I characteristic of a solar cell panel array circuit when partial shading problem happens, is simulated. The global peak power and the local peak power points is confirmed by simulations. Voltage and current values and patterns of V-I characteristic are analyzed. The generating efficiency of the solar cell panel array is improved, when the solar cell panel array circuit is operated at the power point estimated by setting up specific range.

Growth of $CdS_{0.67}Se_{0.33}$ single crystal by sublimation method and their photoconductive characteristics (승화법에 의한 $CdS_{0.67}Se_{0.33}$ 단결정 성장과 광전도 특성)

  • Hong, K.J.;Lee, S.Y.
    • Journal of Sensor Science and Technology
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    • v.7 no.2
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    • pp.131-139
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    • 1998
  • $CdS_{0.67}Se_{0.33}$ single crystal was grown by vertical sublimation method of closed tube physical vapour deposition. The (0001) growth plane of oriented single crystals was confirmed from the back-ref1ection Laue patterns. From the Hall effects by van der Pauw method, the as-grown $CdS_{0.67}Se_{0.33}$ single crystals were found to be n-type semiconductors. The mobility appeared to be decreased by lattice scattering at temperature range from 150K to 293K and by impurity scattering at temperatures ranging from 30K to 150K In order to explore its applicability in photoconductive cells, we measured the ratio of photo-current to dark-current (pc/dc), maximum allowable power dissipation (MAPD), spectral response and response time respectively. The results indicated that for the samples annealed in Cu vapour the photoconductive characteristics are best. We obtained sensitivity of 0.99, the value of pc/de of $1.84{\times}10^{7}$, the MAPD of 323mW and the rise and decay time of 9.3 ms and 9.7 ms, respectively.

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The Study on Characteristic Composition of As in a-Se with X-ray Detection Sensor using $CaWO_4/a-Se$ (다층구조($CaWO_4/a-Se$) 기반의 X선 검출센서에서 a-Se에 첨가된 As의 특성비 연구)

  • Choe, Jang-Yong;Lee, Dong-Gil;Sin, Jeong-Uk;Kim, Jae-Hyeong;Nam, Sang-Hee;Park, Ji-Koon;Kang, Sang-Sik;Jang, Gi-Won;Lee, Hung-Won
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2002.11a
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    • pp.432-435
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    • 2002
  • The ultimate study of this research is to improve the properties of digital X-ray receptor based on amorphous selenium. There are being two prominent studying for Digital Radiography. Direct and Indirect method of Digital Radiography are announced for producing high quality digital image. But each two systems have strength and weakness. This is a basic research for developing of Hybrid digital radiography which is a new type X-ray detector. ln this study, we investigated the electrical characteristic of multi-layer$(CaWO_4+a-Se)$ as a photoconductor according to the changing iodine composition ratio. The iodine composition ratio of a-Se compound is classified into 5 different kinds which have 30ppm, 100ppm, 300ppm, 500ppm, 700ppm and were made test sample throught thermo-evaporation. The phosphor layer of $CaWO_4$ was overlapped on a-Se using EFIRON optical adhesives. We measured the dark and photo current about the test sample and compared the electrical characteristic of the net charge and signal-to-noise ratio. Among other things, test sample of compound material of 700ppm iodine showed good characteristic of $2.53nA/cm^2$ dark current and $479nC/cm^2{\cdot}mR$ net charge at $3V/{\mu}m$.

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Application of $TiO_2$-Coated Construction Materials for Nicotine Photo-decomposition (니코틴 광분해를 위한 산화티타늄 코팅 건축자재 활용)

  • Jo, Wan-Kuen;Chun, Hee-Dong
    • Journal of Korean Society of Environmental Engineers
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    • v.28 no.3
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    • pp.316-322
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    • 2006
  • The current study evaluated the technical feasibility of the application of $TiO_2$ photocatalysis for the removal of nocotine which has well known as a representative material of environmental tobacco smoke(ETS). Four different preliminary experiments were performed for the evaluation of nicotine removal using photocatalyst-coated construction materials. The photocatalytic removal of nicotine was investigated for five parameters: dry condition of coating tiles, type of coating sol, number of coatings, relative humidity(RH), and input concentrations. Prior to performing the parameter tests, adsorption of nicotine onto the current experimental system was surveyed. All the variables tested in the present study exhibited to influence the photocatalytic decomposition of Nicotine. A dry condition of high temperature and short dry period presented higher photocatalytic oxidation(PCO) efficiency compared to that of low temperature and long dry period. ST-KO3 sol showed higher decomposition efficiency than E-T Sol. The PCO efficiency increased as the number of coating increased. High humidity and low input concentrations exhibited higher PCO efficiency. Consequently, it is noted that the five parameters tested in the present study should be considered for the application of photocatalyst-coated construction materials in cleaning nicotine in ETS.

Surface reaction of $HfO_2$ etched in inductively coupled $BCl_3$ plasma ($BCl_3$ 유도결합 플라즈마를 이용하여 식각된 $HfO_2$ 박막의 표면 반응 연구)

  • Kim, Dong-Pyo;Um, Doo-Seunng;Kim, Chang-Il
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2008.06a
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    • pp.477-477
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    • 2008
  • For more than three decades, the gate dielectrics in CMOS devices are $SiO_2$ because of its blocking properties of current in insulated gate FET channels. As the dimensions of feature size have been scaled down (width and the thickness is reduced down to 50 urn and 2 urn or less), gate leakage current is increased and reliability of $SiO_2$ is reduced. Many metal oxides such as $TiO_2$, $Ta_2O_4$, $SrTiO_3$, $Al_2O_3$, $HfO_2$ and $ZrO_2$ have been challenged for memory devices. These materials posses relatively high dielectric constant, but $HfO_2$ and $Al_2O_3$ did not provide sufficient advantages over $SiO_2$ or $Si_3N_4$ because of reaction with Si substrate. Recently, $HfO_2$ have been attracted attention because Hf forms the most stable oxide with the highest heat of formation. In addition, Hf can reduce the native oxide layer by creating $HfO_2$. However, new gate oxide candidates must satisfy a standard CMOS process. In order to fabricate high density memories with small feature size, the plasma etch process should be developed by well understanding and optimizing plasma behaviors. Therefore, it is necessary that the etch behavior of $HfO_2$ and plasma parameters are systematically investigated as functions of process parameters including gas mixing ratio, rf power, pressure and temperature to determine the mechanism of plasma induced damage. However, there is few studies on the the etch mechanism and the surface reactions in $BCl_3$ based plasma to etch $HfO_2$ thin films. In this work, the samples of $HfO_2$ were prepared on Si wafer with using atomic layer deposition. In our previous work, the maximum etch rate of $BCl_3$/Ar were obtained 20% $BCl_3$/ 80% Ar. Over 20% $BCl_3$ addition, the etch rate of $HfO_2$ decreased. The etching rate of $HfO_2$ and selectivity of $HfO_2$ to Si were investigated with using in inductively coupled plasma etching system (ICP) and $BCl_3/Cl_2$/Ar plasma. The change of volume densities of radical and atoms were monitored with using optical emission spectroscopy analysis (OES). The variations of components of etched surfaces for $HfO_2$ was investigated with using x-ray photo electron spectroscopy (XPS). In order to investigate the accumulation of etch by products during etch process, the exposed surface of $HfO_2$ in $BCl_3/Cl_2$/Ar plasma was compared with surface of as-doped $HfO_2$ and all the surfaces of samples were examined with field emission scanning electron microscopy and atomic force microscope (AFM).

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Estimation of the Original Location of Haechi (Haetae) Statues in Front of Gwanghwamun Gate Using Archival Photos from Early 1900s and Newly Taken Photos by Image Analysis (1900년대 초반의 기록사진과 디지털 카메라 사진분석을 활용한 광화문 앞 해치상의 원위치 추정)

  • Oh, Hyundok;Nam, Ho Hyun;Yoo, Yeongsik;Kim, Jung Gon;Kang, Kitaek;Yoo, Woo Sik
    • Journal of Conservation Science
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    • v.37 no.5
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    • pp.491-504
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    • 2021
  • Gwanghwamun Gate of Gyeongbokgung Palace was dismantled and relocated during the Japanese colonial period, destroyed during the Korean War, reconstructed with reinforced concrete in 1968, and finally erected at its present location in 2010. A pair of Haechi statues located in front of Gwanghwamun was dismantled and relocated several times, and the statues have yet to be returned precisely to their original positions. This study assesses the historical accuracy of their current placement under the Gwanghwamun Square Restructuring Project of the Seoul Metropolitan Government and the Cultural Heritage Administration based on archival photos from the early 1900s, and proposes a method to estimate the original positions of the Haechi through image analysis of contemporary photographs and recent digital camera photos. We estimated the original position of the Haechi before the Japanese colonial period by identifying the shooting location of the archival photo and reproducing contemporary photographs by calculating the angle and distance to the Haechi from the shooting location. The leftmost and rightmost Haechi were originally located about 9.6 m to the east and 7.4 m to the north and about 1.9 m to the west and 8.0 m to the north, respectively, of their current location indicators. As the first attempt to determine the original location of a building and its accessories using archival photos, this study launches a new scientific methodology for the restoration of cultural properties.

A Study on the Historical Values of the Changes of Forest and the Major Old Big Trees in Gyeongbokgung Palace's Back Garden (경복궁 후원 수림의 변화과정 및 주요 노거수군의 역사적 가치규명)

  • Shin, Hyun-Sil
    • Journal of the Korean Institute of Traditional Landscape Architecture
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    • v.40 no.2
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    • pp.1-13
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    • 2022
  • This paper examined the history and development of Gyeongbokgung Palace's back garden based on historical materials and drawings such as Joseon Ilgi(Diaries of Joseon Dynasty), Joseon Wangjo Sillok(the Annals of the Joseon Dynasty), Doseongdaejido(the Great Map of Seoul), Bukgwoldohyeong(Drawing Plan of the Northern Palace), the Bukgung Palace Restoration Plan, Restoration Planning of Gyeongbokgung Palace and the following results were derived. First, it was confirmed that the Back Garden of Gyeongbokgung Palace was famous for its great location since the Goryeo Dynasty, and that it was named Namkyeong at that time and was a place where a shrine was built, and that castles and palaces were already built during the Goryeo Dynasty under the influence of Fengshui-Docham(風水圖讖) and Zhouli·Kaogongji(周禮考工記). Although the back garden of Gyeongbokgung Palace in the early Joseon Dynasty stayed out of the limelight as a back garden for the palace, it has a place value as a living space for the head of the state from King Gojong to the present. Second, in order to clearly identify the boundaries of back garden, through literature such as map of Doseongdo (Map of the Capital), La Coree, Gyeongmudae Area, Japanese Geography Custom Compendium, Korean Photo Album, JoseonGeonchukdoJip(The Illustration Book of Joseon Construction), Urban Planning Survey of Gyeongseong, it was confirmed that the current Blue House area outside Sinmumun Gate was built outside the precincts of Gyeongbokgung Palace. It was found that the area devastated through the Japanese Invasion of Korea in 1592, was used as a space where public corporations were combined through the process of reconstruction during the King Gojong period. In Japanese colonial era, the place value as a back garden of the primary palace was damaged, as the palace buildings of the back garden was relocated or destroyed, but after liberation, it was used as the presidential residence and restored the place value of the ruler. Third, in the back garden of Gyeongbokgung Palace, spatial changes proceeded through the Japanese Invasion and Japanese colonial era. The place with the greatest geographical change was Gyeongnongjae area, where the residence of the Japanese Government-General of Korea was built, and there were frequent changes in the use of the land. On the other hand, the current Gyeongmudae area, the forests next to the small garden, and the forests of Baekak were preserved in the form of traditional forests. To clarify this, 1:1200 floor plan of inner Gyeongmudae residence and satellite images were overlapped based on Sinmumun Gate, and as a result, it was confirmed that the water path originating from Baekak still exists today and the forest area did not change. Fourth, in the areas where the traditional forest landscape was inherited, the functional changes in the topography were little, and major old-age colonies are maintained. The old trees identified in this area were indicator tree species with historical value. Representatively, Pinus densiflora for. multicaulis Uyeki, located in Nokjiwon Garden, is presumed to have been preserved as one of Pinus densiflora for. multicaulis Uyeki planted next to Yongmundang, and has a historicality that has been used as a photo zone at dinners for heads of state and important guests. Lastly, in order to continuously preserve and manage the value of Gyeongbokgung Palace in Blue House, it is urgent to clarify the space value through excavation of historical materials in Japanese colonial era and establish a hierarchy of garden archaeology by era. In addition, the basis for preserving the historical landscape from the Joseon Dynasty to the modern era from Gyeongbokgung Palace should not damage the area of the old giant trees, which has been perpetuated since the past, and a follow-up study is needed to investigate all the forests in Blue House.

The Scattering Beam Measurement of the RBC and the Fabrication of the Micro Cell Biochip (적혈구의 산란빔 측정과 마이크로 세포 분석 바이오칩 제작)

  • Byun, In Soo;Kwon, Ki Jin;Lee, Joon Ha
    • Progress in Medical Physics
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    • v.25 no.2
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    • pp.116-121
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    • 2014
  • Next future, The bio technology will be a rapidly developing. This paper is the scattering beam measurement of the red blood cell (RBC) and the fabrication of the micro cell biochip using the bio micro electro mechanical system (Bio-MEMS) process technology. The Major process method of Bio-MEMS technology was used the buffered oxide etchant (BOE), electro chemical discharge (ECD) and ultraviolet sensitive adhesives (UVSA). All experiments were the 10 times according to the process conditions. The experiment and research are required the ultraviolet expose, the micro fluid current, the cell control and the measurement of the output voltage Vpp (peak to peak) waveform by scattering angles. The transmitting and receiving of the laser beam was used the single mode optical fiber. The principles of the optical properties are as follows. The red blood cells were injected into the micro channel. The single mode optical fiber was inserting in the guide channel. The He-Ne laser beam was focusing in the single mode optical fiber. The transmission He-Ne laser beam is irradiating to the red blood cells. The manufactured guide channel consists of the four inputs and the four outputs. The red blood cell was allowed with the cylinder pump. The output voltage Vpp waveform of the scattering beam was measured with a photo detector. The receiving angle of the output optical fiber is $0^{\circ}$, $5^{\circ}$, $10^{\circ}$, $15^{\circ}$. The magnitude of the output voltage Vpp waveform was measured in the decrease according to increase of the reception angles. The difference of the output voltage Vpp waveform is due differences of the light transmittance of the red blood cells.

Optical Communication and Sensing Modules for Plastic Optical Fibers (고분자광섬유용 광통신 및 센서 모듈)

  • Park, Byung-Wook;Yoon, Do-Young;Kim, Dong-Shik
    • Korean Chemical Engineering Research
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    • v.47 no.5
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    • pp.558-564
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    • 2009
  • POF(Polymer optical fiber) offers advantages of lighter, inexpensive, and easier to use over GOF(glass optical fiber). Its higher transmission loss and low bandwidth, however, make it suitable only for short distance networking such as LAN. The polymer materials and its synthesis technology of low transmission loss and the broader application for flexible POF are the two of many critical areas to be investigated more. In the current study, low-noise POF modules are developed and optimized with a low noise amplifier and low cost LED of 650 nm. In order to demonstrate the dynamic characteristics of the POF module for optical communication and sensing, we have built an image transfer module, optical transmission speed measurement module, optical transceiver for RS-232, and sound-transfer module, and the signal characteristics of them are evaluated. It is found that the module can be readily used for a quick and simple measurement of optical transfer speed. With help of analog amplifier, LED, and PD, sound and image transfers through a maximum 60 m optical waveguide have been confirmed. Real-time data transfer was also demonstrated in PID control, which is thought to be valuable to industrial plant design and control.