• Title/Summary/Keyword: analysis-dark current

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Photoelectric Properties of PbTe/CuPc Bilayer Thin Films (PbTe/CuPc 이층박막의 광전 특성)

  • Lee, Hea-Yeon;Kang, Young-Soo;Park, Jong-Man;Lee, Jong-Kyu;Jeong, Jung-Hyun
    • Journal of Sensor Science and Technology
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    • v.7 no.1
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    • pp.67-72
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    • 1998
  • The crystallized CuPc and PbTe films are formed by thermal evaporation and pulsed ArF excimer laser ablation. Structural and electrical properties of thin film is observed by XRD and current-voltage(I-V) curves. From XRD analysis, both PbTe and CuPc thin films show a-axis oriented structure. For the measurement of photovoltaic effect, the transverse current-voltage curve of CuPc/Si, PbTe/Si and PbTe/CuPc/Si junctions have been analyzed in the dark and under illumination. The PbTe/CuPc/Si junction exthibits a strong photovoltaic characteristics with short circuit current($J_{sc}$) of $25.46\;mA/cm^{2}$ and open-circuit voltage($V_{oc}$) of 170 mV. Quantum efficiency and power conversion efficiency are calculated to be 15.4% and $3.46{\times}10^{-2}$, respectively. Based on the results of QE and ${\eta}$, the photocurrent process of PbTe/CuPc/Si junction can be explained as following three effective steps; photocarrier generation in the CuPc layer, carrier separation at PbTe/CuPc interface, and finally a transportation of electrons through the PbTe layer.

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FAR-IR GALACTIC EMISSION MAP AND COSMIC OPTICAL BACKGROUND

  • Matsuoka, Y.
    • Publications of The Korean Astronomical Society
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    • v.27 no.4
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    • pp.353-356
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    • 2012
  • We present new constraints on the cosmic optical background (COB) obtained from an analysis of the Pioneer 10/11 Imaging Photopolarimeter (IPP) data. After careful examination of the data quality, the usable measurements free from the zodiacal light are integrated into sky maps at the blue (${\sim}0.44{\mu}m$) and red (${\sim}0.64{\mu}m$) bands. Accurate starlight subtraction was achieved by referring to all-sky star catalogs and a Galactic stellar population synthesis model down to 32.0 mag. We find that the residual light is separated into two components: one component shows a clear correlation with the thermal $100{\mu}m$ brightness, whilst the other shows a constant level in the lowest $100{\mu}m$ brightness region. The presence of the second component is significant after all the uncertainties and possible residual light in the Galaxy are taken into account, thus it most likely has an extragalactic origin (i.e., the COB). The derived COB brightness is ($(1.8{\pm}0.9){\times}10^{-9}$ and $(1.2{\pm}0.9){\times}10^{-9}\;erg\;s^{-1}\;cm^{-2}\;sr^{-1}\;{\AA}^{-1}$ in the blue and red spectral regions, respectively, or $7.9{\pm}4.0$ and $7.7{\pm}5.8\;nW\;m^{-2}\;sr^{-1}$. Based on a comparison with the integrated brightness of galaxies, we conclude that the bulk of the COB is comprised of normal galaxies which have already been resolved by the current deepest observations. There seems to be little room for contributions from other populations including "first stars" at these wavelengths. On the other hand, the first component of the IPP residual light represents the diffuse Galactic light (DGL)-scattered starlight by the interstellar dust. We derive the mean DGL-to-$100{\mu}m$ brightness ratios of $2.1{\times}10^{-3}$ and $4.6{\times}10^{-3}$ at the two bands, which are roughly consistent with previous observations toward denser dust regions. Extended red emission in the diffuse interstellar medium is also confirmed.

The Characteristics of Achromatic & Chromatic Color Coordination In Current Women's Fashion -Centered on the Collections of Paris, Milan, New York, London - (현대 패션에 나타난 무채색과 유채색 코디네이션 특성 - 파리, 밀란, 뉴욕, 런던 컬렉션 중심으로 -)

  • Kwon, Hae-Sook
    • Journal of Fashion Business
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    • v.12 no.4
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    • pp.73-87
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    • 2008
  • The main objective of this research was to investigate the characteristics of achromatic & chromatic color coordination of contemporary female fashion by reviewing 'pre-a-porter Collections' of four collections (i. e. cities) - Paris, Milan, New York, London - from the periods of 2002 S/S to 2006/7 A/W. The data was collected by reviewing 'pre-a-porter Collections' magazine and total 677 observations were made. Statistical analysis of frequency and also qualitative interpretation of achromatic & chromatic color coordination characteristics were completed. The main findings were; (1) The achromatic & chromatic color coordination was identified as one of most used color coordination in contmeporary women's fashion collections. (2) Black and white mainly used for achromatic color, and brown used the most often, then followed by blue, red, yellow, green and the others for chromatic color in achromatic & chromatic coordination of contmeporary women's fashion collections. (3) The characteristics of achromatic & chromatic color coordination of modern women's fashion collections from 2002 S/S to 2006/07 A/W showed various images according to chromatic colors and tone variation. The combination of achromaticand brown color variations produced an intelligent and sophisticated image. The soft or light chromatic color and chromatic color combination projected soft, feminine and subtle feeling, while the combination of vivid or strong chromatic color and achromatic color projected a clean and strong feeling through contrasting tones of clear and bright colors. The chromatic color of deep or dark tone and black combination demonstrated supernatural and gloomy image. (4)In all four collections, Paris showed most use of two color coordination and then followed by Milan, N.Y, and London. N.Y showed higher rate of using achromatic & chromatic color coordination, and then followed by Paris, London and Milan.

SPECTROSCOPIC AND PHOTOMETRIC STUDY OF STARBURST GALAXIES: OPTICAL AND NEAR INFRARED PROPERTIES OF A BLUE COMPACT DWARF GALAXY MRK 49 IN THE VIRGO CLUSTER

  • Sung, Eon-Chang;Kyeong, Jae-Mann;Byun, Yong-Ik
    • Journal of The Korean Astronomical Society
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    • v.41 no.5
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    • pp.121-137
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    • 2008
  • We present optical and near-infrared imaging and long-slit spectroscopy for the blue compact dwarf galaxy (BCD) Mrk 49 in the Virgo Cluster. The surface brightness distribution analysis shows that Mrk 49 consists of an off-centered blue bright compact core of r = 10" and a red faint outer exponential envelope. The $H_{\alpha}$ image and color difference suggest that these two components have different stellar populations: a high surface brightness population of massive young stars and an underlying low surface brightness population of older stars. The redder near-infrared colors of the inner most region suggest that the near-infrared flux of Mrk 49 originates from evolved massive stars associated with the current star-forming activity. The total apparent magnitude is $B_T\;=\;14.32$ mag and the mean effective surface brightness is ${\mu}_{eff}(B)\;=\;21.56$ mag $arcsec^{-2}$. Long-slit spectroscopy shows that Mrk 49 rotates apparently as a solid body within r = 10" in a plane at position angle 55 degrees with an amplitude of about $20\;km\;sec^{-1}$. The measured radial velocity of Mrk 49 was derived as $1,535\;km\;sec^{-1}$; and the total mass of stars and gases is in the range of 3 to $6\;{\times}\;10^9\;M_{\odot}$. The mass-to-light ratios for the central region of Mrk 49 in I and B band are estimated 1.0 and 0.5, respectively. The upper limit of the dark matter to visible matter ratio seems to be < 5. The oxygen abundance is $12\;+\;\log(O/H)\;=\;8.21\;{\pm}\; 0.1$ which is about one quarter of the solar value while the relative helium abundance appears to be similar to that of the sun.

A Study of the Concept of Futuristic Image in Fashion Since 2000 (2000년 이후 패션에 나타난 미래적 이미지의 개념에 관한 연구)

  • Kim, Yoon-Hee
    • Journal of the Korean Society of Costume
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    • v.58 no.2
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    • pp.107-119
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    • 2008
  • This study aims to define the concept of the futuristic image in fashion since 2000. In this study, earlier studies of the futuristic images in the fashion are analyzed and it is discovered that the most important characteristics of the futuristic images are the cosmic space and virtual reality. An analysis of actual data of the futuristic images of the fashion since 2000 produces the following conclusions. First, since 2000 the futuristic fashion to convey the image of space tends to be minimalist, taking H or A silhouette and using white, silver, or other vivid colors. Second, since 2000 the image of virtual reality is often expressed in the fashion of futuristic image as female fighters or vampires of the future who mostly wear pants suit or skirts that expose the body line. Materials of advanced technology or shiny leather are often used and dark colors including black are dominant in these images. Third, when the space image is expressed, the androgynous youth is emphasized. However when female fighters or vampires of the future are shown, sexual image of gloomy atmosphere is often stressed. Fourth, the fashion of futuristic image since 2000 takes up the space age look of the 1960s and the techno-cyber look of the 1980s and the 1990s. However their internal meanings are lost and only external forms are repeated. In sum, the current fashion of futuristic image emulates the past look of the fashion which was circulated as futuristic images and may be considered as a result of combination of futuristic image and retrospective image.

A Study on Hybrid Characteristics in the Work of Chinese Rising Fashion Designers (중국 신진 패션 디자이너의 작품에 나타난하이브리드 특성 연구)

  • Bin, Sen;Yum, Haejung
    • Journal of Fashion Business
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    • v.24 no.1
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    • pp.1-14
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    • 2020
  • Based on the trend of pluralization and globalization the collapse of national borders now is a manifestation of mixed and compromised cultures and societies. It is also emerging as a hybrid fashion in fashion. Hybrid fashion means creating a new image by mixing various cultures beyond the time and space. This study aims to analyze the current state of Chinese fashion design and present its direction by grasping the characteristics of hybrids in the works of rising Chinese fashion designers in the era of pluralization. The research method was literature review and empirical research. According to the selection criteria of new fashion designers, 6 new fashion designers of 5 fashion brands were selected and their total 458 points works were analyzed. The analysis results are as follows. First, most of the time trade-offs were 'past and present' trade-offs that express Chinese traditional culture and the image of the past with modern design. The trade-offs between 'present and future' is expressed by mixing print patterns, colors and light with fractal art. Second, spatial trade-offs was expressed in the way of expressing Chinese themes in the composition of western clothing, expressing the Western themes in oriental colors, and inspired by Japanese culture expressed by deconstructionism, Third, the gender mix mainly used dark embroidery on women's clothing, while the men's wear showed a delicate feminine charm with a surreal pattern on thin and transparent gauze fabric.

CNN based Raman Spectroscopy Algorithm That is Robust to Noise and Spectral Shift (잡음과 스펙트럼 이동에 강인한 CNN 기반 라만 분광 알고리즘)

  • Park, Jae-Hyeon;Yu, Hyeong-Geun;Lee, Chang Sik;Chang, Dong Eui;Park, Dong-Jo;Nam, Hyunwoo;Park, Byeong Hwang
    • Journal of the Korea Institute of Military Science and Technology
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    • v.24 no.3
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    • pp.264-271
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    • 2021
  • Raman spectroscopy is an equipment that is widely used for classifying chemicals in chemical defense operations. However, the classification performance of Raman spectrum may deteriorate due to dark current noise, background noise, spectral shift by vibration of equipment, spectral shift by pressure change, etc. In this paper, we compare the classification accuracy of various machine learning algorithms including k-nearest neighbor, decision tree, linear discriminant analysis, linear support vector machine, nonlinear support vector machine, and convolutional neural network under noisy and spectral shifted conditions. Experimental results show that convolutional neural network maintains a high classification accuracy of over 95 % despite noise and spectral shift. This implies that convolutional neural network can be an ideal classification algorithm in a real combat situation where there is a lot of noise and spectral shift.

A Study on the Analysis of the Potential FT(Financing of Terrorism) Threat Using Virtual Currencies and Its Response (가상통화를 활용한 테러자금조달 위협 분석과 국내 대응방안에 관한 연구)

  • Kang, Taeho;Cha, Jang-Hyeon;Kim, Gunin
    • Korean Security Journal
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    • no.62
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    • pp.9-33
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    • 2020
  • This study presents aspects of the financing of terrorism using virtual-currencies. Fisrt of all, this introduces the conventional threat of the financing of terrorism and the analysis of current legal system regarding virtual-currency in South Korea. Next, the financing of terrorism cases are analyzed. With given analysis, the paper deals with its response and future extensions by technical and institutional aspects. The threats of the financing of terrorism are going higher after the appearance of virtual-currencies such as Bitcoin. There are two typical ways to use virtual-currencies by terrorist groups. One is to conduct public fund-raising in the social network system and the dark web. The other is to hack into virtual-currency exchange network in order to steal virtual currencies for developing the weapon of mass destruction. Specifically South Korea is top three country of trading virtual currencies and has been subject to virtual-currency hacking more than 10 cases. However, many countries including South Korea deal with virtual currencies as only innovative technology and means of investment, not the threats of the financing of terrorism. Under these circumstances, there a the legal contradiction. This article points this limit and absurdity. Also, it shows reasonable alternatives. All in all, given these aspects, the article proposes detailed policy directions.

Depositional Environment and Formation Ages of Eurimji Lake Sediments in Jaechon City, Korea (제천 의림지 호저퇴적물 퇴적환경과 형성시기 고찰)

  • 김주용;양동윤;이진영;김정호;이상헌
    • The Korean Journal of Quaternary Research
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    • v.14 no.1
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    • pp.7-31
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    • 2000
  • Quaternary Geological and geophysical investigation was performed at the Eurimji reservoir of Jaechon City in order to interprete depositional environment and genesis of lake sediments. For this purpose, echo sounding, bottom sampling and columnar sampling by drilling on board and GPR survey were employed for a proper field investigation. Laboratory tests cover grain size population analysis, pollen analysis and $^{14}C$ datings for the lake sediments. The some parts of lake bottom sediments anthropogenically tubated and filled several times to date, indicating several mounds on the bottom surface which is difficult to explain by bottom current. Majority of natural sediments were accumulated both as rolling and suspended loads during seasonal flooding regime, when flash flow and current flow are relatively strong not only at bridge area of the western part of Eurimji, connected to stream valley, but at the several conduit or sewage system surrounding the lake. Most of uniform suspend sediments are accumulated at the lake center and lower bank area. Some parts of bottom sediments indicate the existence of turbid flow and mudflow probably due to piezometric overflowing from the lake bottom, the existence of which are proved by CM patterns of the lake bottom sediments. The columnar samples of the lake sediments in ER-1 and ER-3-1 boreholes indicate good condition without any human tubation. The grain size character of borehole samples shows poorly sorted population, predominantly composed of fine sand and muds, varying skewness and kurtosis, which indicate multi-processed lake deposits, very similar to lake bottom sediments. Borehole columnar section, echo sounding and GPR survey profilings, as well as processed data, indicate that organic mud layers of Eurimji lake deposits are deeper and thicker towards lower bank area, especially west of profile line-9. In addition the columnar sediments indicate plant coverage of the Eurimji area were divided into two pollen zones. Arboreal pollen ( AP) is predominant in the lower pollen zone, whreas non-aboreal pollen(NAP) is rich in the upper pollen zone. Both of the pollen zones are related to the vegetation coverage frequently found in coniferous and deciduous broad-leaved trees(mixed forest) surrounded by mountains and hilly areas and prevailing by aquatic or aquatic margin under the wet temperate climate. The $^{14}C$ age of the dark gray organic muds, ER1-12 sample, is 950$\pm$40 years B.P. As the sediments are anthropogenetically undisturbed, it is assumed that the reliability of age is high. Three $^{14}C$ ages of the dark gray organic muds, including ER3-1-8, ER3-1-10, ER3-1-11 samples, are 600$\pm$30 years B.P., 650$\pm$30 years B.P., 800$\pm$40 years B.P. in the descending order of stratigraphic columnar section. Based on the interpretation of depositional environments and formation ages, it is proved that Eurimji reservoir were constructed at least 950$\pm$40 years B.P., the calibrated ages of which ranges from 827 years, B.P. to 866 years B.P. Ancient people utilize the natural environment of the stream valley to meet the need of water irrigation for agriculture in the local valley center and old alluvium fan area.

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A Study on the Early North Sung Period Buddhist Literatures Found in the Pagoda of Suzhou Ruiguangsi (소주(蘇州) 서광사탑(瑞光寺塔) 출토(出土) 북송초기(北宋初期)의 불교문헌(佛敎文獻) 연구(硏究))

  • Song, Il-Gie
    • Journal of Korean Library and Information Science Society
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    • v.45 no.1
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    • pp.81-102
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    • 2014
  • In 1978, there was an investigation before the repair of the pagoda in Suzhou Ruiguangsi (蘇州 瑞光寺) and many Buddhist literatures were found in the center of pagoda's 3rd floor. This study is the analysis of the forms and values of the literatures. Since there were 123 ea of precious literatures made from Tang (唐) period to early North Sung (北宋) period among the found Buddhist literatures, they have very important meaning in the bibliography for the time. Suzhou Reiguangsi (蘇州 瑞光寺) was built by the first king of Wu (吳), Sun Quan (孫權). He built this Buddhist temple to meet Monk Xingkang (性康) from Kangjuguo (康居國). When it had been first built, it had been called Puji Chanyuan (普濟禪院) and it was renamed as current Ruiguangsi (瑞光寺) after the major expansion in the early period of North Sung (北宋). The Ruiguangta (瑞光塔) was built by Sun Quan (孫權) in A.D. 247 immediately after the temple had been built. Sun Quan built this pagoda as a 13-floor pagoda to pray for the easy passage into eternity of his mother, national prosperity and welfare of the people. As time passed by, the pagoda was largely damaged and it was newly built in A.D. 1017 (天禧 1) of early North Sung (北宋) period; while it was named as Duobaota (多寶塔). The literatures found in Ruiguangta consist of 107 ea of 3 sets dharani (陀羅尼) scripture and 16 volumes of 5 books, total 123 ea. Especially, there were 7 books of full set transcript of Lotus Sutra (法華經) in relatively complete form. This sutra written in gilt lettering on dark blue paper was made in Middle Tang (中唐) period and it is believed to be the only one existing in East Asia as a scripture written in gilt lettering on dark blue paper (紺紙金字寫經). There were also 6 books of small letter edition of Lotus Sutra (法華經) in complete form, which was published during the early North Sung (北宋) period. This specific edition is incorrectly stated in most general reference books published in China as having been engraved in early Tang period (初唐) since a Japanese scholar wrongly introduced it as having been engraved together with Nakamura edition (中村本). It is meaningful that this error can be corrected by the finding of this study.