• Title/Summary/Keyword: intercomparison

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Intercomparison of the Global Ocean Reanalysis Data (전지구 해양 재분석 자료 비교 분석)

  • Chang, You-Soon
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.20 no.2
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    • pp.102-118
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    • 2015
  • This study summarized the results of the international ocean reanalysis intercomparison project. We introduced the characteristics of various ocean reanalysis systems and analyzed the assimilated performance on the typical eight oceanic variables (heat content, steric height, sea level, surface heat fluxes, mixed layer depth, subsurface salinity, depth of $20^{\circ}C$ isotherm, sea ice). In general, ensemble means show better estimations than those of any individual ocean reanalysis, but it depends on analyzed regions and variables. Among the eight oceanic variables, salinity and sea ice variabilities have large spreads among models. The deep sea, Southern Ocean, and coastal regions including western boundary current commonly appear as the areas with largest uncertainty between different objective analyses and assimilation models. We expect that intercomparison project for the ocean assimilation models independently operated in Korea should be processed, which allows us to join relevant international programs in the near future.

Intercomparison Exercise on Internal Dose Assessment in Korea (국내 내부피폭방사선량 평가 상호비교)

  • Lee, Jong-Il;Kim, Jang-Lyul;Kim, Bong-Hwan
    • Journal of Radiation Protection and Research
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    • v.36 no.2
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    • pp.64-70
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    • 2011
  • The intercomparison exercise on internal dose assessment has been carried out for the purpose of the evaluation for harmonization of internal dosimetry between the nuclear-related institutes in Korea. The exercises of 9 items on internal dose assessment have been developed for the unknown internal dosimetric parameters such as the intake pathway, absorption type, AMAD, and intake time of a radionuclide. Solutions to these exercises were reported by 7 participants from 5 institutes. The range of the ratio between the individual values and the geometric mean value of the evaluated doses for the exercises was $5.75{\times}10^{-4}$ ~ 9.81. But without the extreme partial solution, the range of the ratio was 0.216 ~ 3.12.

APMP (Asia Pacific Metrology Programme) Regional Intercomparison Results of Acoustic Calibrators (음향교정기의 아시아.태평양 지역 국제비교 결과)

  • 서상준;서재갑;조문재
    • The Journal of the Acoustical Society of Korea
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    • v.22 no.6
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    • pp.463-471
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    • 2003
  • The results of the APMP (Asia Pacific Metrology Programme) regional intercomparison of acoustic calibrators were reviewed and analyzed. The artefacts used in intercomparison are a sound level calibrator and a pistonphone. The microphones used to measure the output pressure level are 1" and 1/2" standard microphones (LS1P, LS2P) as well as 1" and 1/2" reference microphones (WS1P/F, WS2P/F). The results obtained using standard microphones are satisfactory, but those obtained by the reference microphones, even though E/sub n/ values are within ±1.0, showed great deviations. Such results had come from the inaccurate calibration of reference microphones. By using the correct calibration results which were obtained by the recently established international standards, the new results were very similar to those of the foreign standard institutes.

Intercomparison and Determination of Trace Elements in Urban Dust by Neutron Activation Analysis (중성자방사화분석법을 이용한 대기분진중의 미량원소 비교분석)

  • Chung, Yong-Sam;Moon, Jong-Hwa;Kim, Sun-Ha;Park, Kwang-Won;Kang, Sang-Hun
    • Analytical Science and Technology
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    • v.13 no.2
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    • pp.179-188
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    • 2000
  • Trace elements in air samples artificially loaded on filters with urban dust and the bulk material of urban dust as an environmental sample were determined non-destructively using instrumental neutron activation analysis. Standard reference material (Urban Dust, SRM 1648) of the National Institute of Standard and Technology was used for the analytical quality control. The relative error for 37 elements was less than 15% and the standard deviation was less than 10%. 29 elements in the urban dust and 21 elements in the loaded filter sample were determined respectively. To evaluate the proficiency and reliability of the measurement, data intercomparison was performed and 39 analytical laboratories participated in the analysis using different analytical methods; neutron activation analysis, particle induced X-ray emission analysis, X-ray fluorescence analysis and atomic absorption spectrometry. Z-scores were calculated using the standard deviation of the laboratorie's mean as target standard deviation, and a good result was obtained that the values fall between -1 and +1 except some elements.

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Review of International Research Cooperation Results for Intercomparison of Luminescence Dating (루미네선스 연대측정 상호비교를 위한 국제공동연구 결과 고찰)

  • Jin Cheul Kim
    • The Korean Journal of Quaternary Research
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    • v.34 no.1
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    • pp.31-40
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    • 2024
  • The Risø Research Institute in Denmark conducted the luminescence dating intercomparison project, which derives equivalent dose, annual dose, and absolute age results for each laboratory from the same sample, and compares the results between laboratories. This project was carried out from 2006 to 2012. In this project, 30 international laboratories worldwide participated, including the luminescence laboratory at the Korea Institute of Geoscience and Mineral Resources (KIGAM). As a result of the project's synthesis, the average value of the results generally shows an over-dispersion value between laboratories of about 13%. The equivalent dose value obtained through the provided quartz analyzed in KIGAM shows results almost identical to the final equivalent dose value of the project. On the other hand, the equivalent dose value obtained from self-extracted quartz analyzed in KIGAM shows a difference of about 0.9 Gy from the final result of the project, which is thought to be due to the difference in particle size of the separated quartz. This international joint research project is the first large-scale international joint study related to luminescence dating and is expected to have contributed to the reliability and use of luminescence dating internationally.

(Technical Note) Introduction of PMIP4 Experimental Design for Simulating Quaternary Climates ((기술노트) PMIP4의 제4기 기후 재현 실험 소개)

  • Sang-Yoon Jun;Seong-Joong Kim
    • The Korean Journal of Quaternary Research
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    • v.33 no.1_2
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    • pp.49-58
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    • 2021
  • In the Paleoclimate Modeling Intercomparison Project phase 4 (PMIP4), various experiments for quaternary climatic change are being carried out along with the Coupled Model Intercomparison Project phase 6 (CMIP6). With the CMIP6 preindustrial climate experiment (piControl), the equilibrium climate simulations of 6 ka Holocene experiment (midHolocene), 21 ka Last Glacial Maximum experiment (lgm), and 127 ka Last Interglacial experiment (lig127k) experiment, and transient climate simulations of 850-1849 Common Era Last Millennium experiment (past1000), 21-9 ka last deglaciation, and 140-127 ka penultimate deglaciation experiment have been carried out under PMIP4 protocols by several modeling groups. In this technical note, important physical parameters and boundary conditions of these Tier 1 experiments and a list of additional Tier 2 and 3 experiments are summarized.

Domestic Intercomparison Study for the Performance of Personnel Dosimeters (개인선량계 성능의 국내 상호비교)

  • Kim, Jang-Lyul;Chang, Si-Young;Kim, Bong-Hwan
    • Journal of Radiation Protection and Research
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    • v.21 no.3
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    • pp.147-153
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    • 1996
  • The Korea Atomic Energy Research Institute(KAERI) conducted a intercomparison study for personnel dosimetry services in Korea to enhance the accuracy and precision of the dosimetry system. Nine types of dosimeters(6 TLD, 3 film badge) from 7 institutions took part in this intercomparison study. Each participant submitted 30 dosimeters including transit control for irradiations. Both TLDs and film badges were irradiated with Cs-137 gamma, Sr/Y-90 beta and 4 X-ray beams in ISO wide series. Four dosimeters were irradiated on phantom with same dose equivalent for each field category. The delivered dose equivalent was in the range of $0.1{\sim}10mSv$. The participants assessed the results of their dosimeter readings in terms of the ICRU operational quantities for personal monitoring, Hp(10) and Hp(0.07). Most participants except 1 dosimeter estimated the delivered dose equivalent with biases less than ${\pm}25%$ for Cs-137 and Sr/Y-90. But for X-rays, the biases exceeded ${\pm}35%$ in some cases bacause the dose evaluation algorithm was based on the ANSI N13.11 X-ray fields which are different from those given by ISO.

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Intercomparison of Chamber Methods for Soil Respiration Measurement in a Phytotron System (식물 환경 조절 시스템에서의 토양 호흡 관측 챔버법의 비교 실험)

  • Chae Namyi;Kim Rae-Hyun;Hwang Taehee;Suh Sang-Uk;Lee Jae-Seok;Son Yowhan;Lee Dowon;Kim Joon
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.7 no.1
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    • pp.107-114
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    • 2005
  • Soil CO₂ emission is one of the primary components in carbon balance of terrestrial ecosystems. In soil CO₂ flux measurements, chamber method is currently the most common technique. Prior to compare or synthesize the data collected from different chamber methods, potential biases must be quantified for each measurement system. We have conducted an intercomparison experiment among four closed dynamic chamber systems and an automatic open-closed chamber system in a temperature-controlled phytotron. Due to the disturbed CO₂ concentrations inside the phytotron during the measurements with closed dynamic chambers and the changes in soil water content, the interpretation of the data was difficult to quantify the biases of individual methods. However, the experiment provided not only valuable information on the performance characteristics of the five instruments to varying soil temperature and CO₂ concentration but also useful insights for better designs and strategy for future intercomparison in a controlled environment.