• Title/Summary/Keyword: intercomparison

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Assessment of Natural Radiation Exposure by Means of Gamma-Ray Spectrometry and Thermoluminescence Dosimetry (감마선분광분석(線分光分析) 및 열형광검출법(熱螢光檢出法)에 의한 자연방사선(自然放射線)의 선량측정연구(線量測定硏究))

  • Jun, Jae-Shik;Oh, Hi-Peel;Choi, Chul-Kyu;Oh, Heon-Jin;Ha, Chung-Woo
    • Journal of Radiation Protection and Research
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    • v.10 no.2
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    • pp.96-108
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    • 1985
  • A study for the assessment of natural environmental radiation exposure at a flat and open field of about $10,000m^2$ in area in CNU Daeduk campus has been carried out by means of gamma-ray scintillation spectrometry and thermoluminescence dosimetry for one year period of time from October 1984. The detectors used were 3'${\phi}{\times}$3' NaI(T1) and two different types of LiF TLD, namely, chip sealed in plastic sheet which tightly pressed on two open holes of a metal plate and Teflon disk. Three 24-hour cycles of in-situ spectrometry, and two 3-month and one 1-month cycles of field TL dosimetry were performed. All the spectra measured were converted into exposure rate by means of G(E) opertaion, and therefrom exposure rate due to terrestrial component of environmental radiation was figured out. Exposure rate determined by the spectrometry was, on average, $(10.54{\pm}2.96){\mu}R/hr$, and the rates of $(12.0{\pm}3.4){\mu}R/hr$ and $(11.0{\pm}3.6){\mu}R/hr$ were obtained from chip and disk TLD, respectively. Fluctuations in diurnal variation of the exposure rate measured by the spectrometry were noticeable sometime even in a single cycle of 24 hours. It is concluded that appropriately combined use of TLD with iu-sitn gamma-ray spectrometry system can give more accurate and precise measure of environmental radiation exposure, and further study for more adequate and sensitive TLD for environmental dosimetry, including improvement and elevation of accuracy in data assessment through inter-laboratory or international intercomparison is necessary.

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Intercomparison of Daegwallyeong Cloud Physics Observation System (CPOS) Products and the Visibility Calculation by the FSSP Size Distribution during 2006-2008 (대관령 구름물리관측시스템 산출물 평가 및 FSSP를 이용한 시정환산 시험연구)

  • Yang, Ha-Young;Jeong, Jin-Yim;Chang, Ki-Ho;Cha, Joo-Wan;Jung, Jae-Won;Kim, Yoo-Chul;Lee, Myoung-Joo;Bae, Jin-Young;Kang, Sun-Young;Kim, Kum-Lan;Choi, Young-Jean;Choi, Chee-Young
    • Korean Journal of Remote Sensing
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    • v.26 no.2
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    • pp.65-73
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    • 2010
  • To observe and analyze the characteristics of cloud and precipitation properties, the Cloud physics Observation System (CPOS) has been operated from December 2003 at Daegwallyeong ($37.4^{\circ}N$, $128.4^{\circ}E$, 842 m) in the Taebaek Mountains. The major instruments of CPOS are follows: Forward Scattering Spectrometer Probe (FSSP), Optical Particle Counter (OPC), Visibility Sensor (VS), PARSIVEL disdrometer, Microwave Radiometer (MWR), and Micro Rain Radar (MRR). The former four instruments (FSSP, OPC, visibility sensor, and PARSIVEL) are for the observation and analysis of characteristics of the ground cloud (fog) and precipitation, and the others are for the vertical cloud characteristics (http://weamod.metri.re.kr) in real time. For verification of CPOS products, the comparison between the instrumental products has been conducted: the qualitative size distributions of FSSP and OPC during the hygroscopic seeding experiments, the precipitable water vapors of MWR and radiosonde, and the rainfall rates of the PARSIVEL(or MRR) and rain gauge. Most of comparisons show a good agreement with the correlation coefficient more than 0.7. These reliable CPOS products will be useful for the cloud-related studies such as the cloud-aerosol indirect effect or cloud seeding. The visibility value is derived from the droplet size distribution of FSSP. The derived FSSP visibility shows the constant overestimation by 1.7 to 1.9 times compared with the values of two visibility sensors (SVS (Sentry Visibility Sensor) and PWD22 (Present Weather Detect 22)). We believe this bias is come from the limitation of the droplet size range ($2{\sim}47\;{\mu}m$) measured by FSSP. Further studies are needed after introducing new instruments with other ranges.

Development Strategy for New Climate Change Scenarios based on RCP (온실가스 시나리오 RCP에 대한 새로운 기후변화 시나리오 개발 전략)

  • Baek, Hee-Jeong;Cho, ChunHo;Kwon, Won-Tae;Kim, Seong-Kyoun;Cho, Joo-Young;Kim, Yeongsin
    • Journal of Climate Change Research
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    • v.2 no.1
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    • pp.55-68
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    • 2011
  • The Intergovernmental Panel on Climate Change(IPCC) has identified the causes of climate change and come up with measures to address it at the global level. Its key component of the work involves developing and assessing future climate change scenarios. The IPCC Expert Meeting in September 2007 identified a new greenhouse gas concentration scenario "Representative Concentration Pathway(RCP)" and established the framework and development schedules for Climate Modeling (CM), Integrated Assessment Modeling(IAM), Impact Adaptation Vulnerability(IAV) community for the fifth IPCC Assessment Reports while 130 researchers and users took part in. The CM community at the IPCC Expert Meeting in September 2008, agreed on a new set of coordinated climate model experiments, the phase five of the Coupled Model Intercomparison Project(CMIP5), which consists of more than 30 standardized experiment protocols for the shortterm and long-term time scales, in order to enhance understanding on climate change for the IPCC AR5 and to develop climate change scenarios and to address major issues raised at the IPCC AR4. Since early 2009, fourteen countries including the Korea have been carrying out CMIP5-related projects. Withe increasing interest on climate change, in 2009 the COdinated Regional Downscaling EXperiment(CORDEX) has been launched to generate regional and local level information on climate change. The National Institute of Meteorological Research(NIMR) under the Korea Meteorological Administration (KMA) has contributed to the IPCC AR4 by developing climate change scenarios based on IPCC SRES using ECHO-G and embarked on crafting national scenarios for climate change as well as RCP-based global ones by engaging in international projects such as CMIP5 and CORDEX. NIMR/KMA will make a contribution to drawing the IPCC AR5 and will develop national climate change scenarios reflecting geographical factors, local climate characteristics and user needs and provide them to national IAV and IAM communites to assess future regional climate impacts and take action.

On Securing Continuity of Long-Term Observational Eddy Flux Data: Field Intercomparison between Open- and Enclosed-Path Gas Analyzers (장기 관측 에디 플럭스 자료의 연속성 확보에 대하여: 개회로 및 봉폐회로 기체분석기의 야외 상호 비교)

  • Kang, Minseok;Kim, Joon;Yang, Hyunyoung;Lim, Jong-Hwan;Chun, Jung-Hwa;Moon, Minkyu
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.21 no.3
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    • pp.135-145
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    • 2019
  • Analysis of a long cycle or a trend of time series data based on a long-term observation would require comparability between data observed in the past and the present. In the present study, we proposed an approach to ensure the compatibility among the instruments used for the long-term observation, which would allow to secure continuity of the data. An open-path gas analyzer (Model LI-7500, LI-COR, Inc., USA) has been used for eddy covariance flux measurement in the Gwangneung deciduous forest for more than 10 years. The open-path gas analyzer was replaced by an enclosed-path gas analyzer (Model EC155, Campbell Scientific, Inc., USA) in July 2015. Before completely replacing the gas analyzer, the carbon dioxide ($CO_2$) and latent heat fluxes were collected using both gas analyzers simultaneously during a five-month period from August to December in 2015. It was found that the $CO_2$ fluxes were not significantly different between the gas analyzers under the condition that the daily mean temperature was higher than $0^{\circ}C$. However, the $CO_2$ flux measured by the open-path gas analyzer was negatively biased (from positive sign, i.e., carbon source, to 0 or negative sign, i.e., carbon neutral or sink) due to the instrument surface heating under the condition that the daily mean temperature was lower than $0^{\circ}C$. Despite applying the frequency response correction associated with tube attenuation of water vapor, the latent heat flux measured by the enclosed-path gas analyzer was on average 9% smaller than that measured by the open-path gas analyzer, which resulted in >20% difference of the sums over the study period. These results indicated that application of the additional air density correction would be needed due to the instrument heat and analysis of the long-term observational flux data would be facilitated by understanding the underestimation tendency of latent heat flux measurements by an enclosed-path gas analyzer.

A Comparative Study on a New Religion, the Idea of the Gaebyok (신종교의 개벽사상 비교)

  • Shin, Jin-sik
    • The Journal of Korean Philosophical History
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    • no.56
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    • pp.81-117
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    • 2018
  • The purpose of this study is to clarify the overall features and its meaning of the Gaebyok(開闢) through the intercomparison of the Gaebyok idea that is the core idea of a newly risen modern religion in Korea. Limitation of most studies so far is that they have stayed in the fragmentary study on the Gaebyok idea of each new religion. In order to overcome this problem, first of all, the Gaebyok idea was studied from a philosophical point encompassing the cosmological view of time in the book of changes. And based on this methodological foundation, with organizing the existing result of study, the process of development and characteristics in the Gaebyok idea of a posteriori Donghak(東學), Right I Ching (正易), Won Buddhism(圓佛敎), and Kangjeungsan(姜甑山) was investigated respectively. And through comparing and analyzing each Gaebyok idea, the similarities and differences between each other were organized. The founders of new religions thought that a great change in the universal and natural luck was made before and after the point of their living. The concept of the frequency of revolution theory is the concept to explain the aspect of transition according to the frequency of revolution(運度) of the cosmological nature that returns to the beginning, and in the idea of the posterior Gaebyok, this content and concepts is contained as it was. This study showed that the concept of the frequency of revolution theory in an apriority and a posterior like those becomes appeared in some preaches of Suun, Ilbu, Sotaesan and Jeungsan. An apriority in the Gaebyok idea of new religion is the world of crisis that represents the limited condition of human being, and a posterity means the religious ideal world realized through the power of the absolute being or a dramatic universal change from that limited circumstances. So the Gaebyok ida is a kind of an universal eschatology and religious view that expects the coming of ideal world in the future. In addition, since the universal eschatology is a kind of a view of time, it inevitably has an issue how long time apriority and a posterity included in it have. And especially, it becomes to premise the content how the social condition and human condition change in an apriority and a posterity. Accordingly, in this study, based on the understanding of the view of time in the cosmological level, the content of answers that each newly risen religion discloses was listed and analyzed with comparison. It can be considered that Suun took charge of a mission to deliver the message through being possessed of a god in heaven who is able to be called a transcendental existence, Ilbu disclosed the coming of the world of a posterity beyond an apriority through the Book of Changes(易學), Jeungsan proclaimed himself as the absolute being who could make such a posterity and bring it, and Sotaesan proposed the Gaebyok of mind in order to meet with the world of a posterity and to live in that era.

19th-Century Morality Dispute in Context of History of Thought - From Four-Seven Dispute to Morality Dispute (사상사(思想史)의 맥락에서 본 19세기 심설논쟁(心說論爭) - 사칠논쟁(四七論爭)에서 심설논쟁(心說論爭)까지 -)

  • Choi, Young-sung
    • The Journal of Korean Philosophical History
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    • no.59
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    • pp.9-38
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    • 2018
  • Joseon Neo-Confucianism had important disputes throughout its hundred years of history. Starting in mid-16th century, Four-Seven Dispute focused on 'Qing (情, emotion)' while Horak Dispute that emerged in early 18th century put emphasis on whether people and things have the same 'Xing (性, nature).' These two disputes lasted until late Joseon. In that process, their issues were clearly recognized and consequently, characteristics of Joseon Neo-Confucianism were well demonstrated. With Western power surging in since mid-18th century, Joseon Neo-Confucianism should develop logic to cope with the Western power. One of responding logics was Zhulilun (主理論, theory of reason) in Neo-Confucianism. Diverse discussions particularly on 'Xin (心, mind)' were expansively made. From the notion of Xin Tong Xing Qing (心統性情) that Xin converges with Xing and Qing, an argument that Xin should be seen as 'Li (理, reason)' and another that Xin is basically 'Qi (氣, force of nature)' were up against each other. The academia heated up with issues raised such as whether Xin and Mingde (明德, bright virtue) are the same notion and whether Mingde should be seen as 'Li' or 'Qi', etc. Defining morality dispute in the late Joseon along with Four-Seven Dispute and Horak Dispute as 'three major disputes in Joseon Neo-Confucianism,' this paper focuses on clarifying their status, actuality and significance. Morality dispute was not only a theoretical dispute. It has significance in the aspect of 'topicality.' It directly and indirectly affected movements against Western and Japanese power, loyal troop's activities and independence movement as well. Compared to Four-Seven Dispute and Horak Dispute, morality dispute is more complex and expansive. In addition, it requires systematic organization of data. Intercomparison of three major disputes is one of key topics to determine characteristics of Joseon Neo-Confucianism.