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        검색결과 13

        4.
        2022.05 구독 인증기관·개인회원 무료
        NFDC (Nuclear Fuel and materials Data Center) developed standard reference data for oxidation of HANA-6 cladding material. Thermo-gravimetric analyzer (TGA) was used to measure oxidation, and the measuring device was self-calibrated using standard materials. The oxidation amount of the HANA6 cladding was measured in an oxidizing atmosphere in the temperature range of 400 to 700°C. Through this, oxidation data, oxidation rate model equation, and graph were developed. The uncertainty factors were analyzed from the oxidation model. The expanded uncertainty of oxidation data was calculated by evaluating the uncertainty for each uncertainty factor. The oxidation data produced in this study was self-rated through deliberation by a specialized committee of NFDC and third experts. It was finally registered as a reference standard through the technical committee of the National Reference Standards Center. It is believed that the standard reference data developed in this study will be helpful for increasing reliability and stability evaluation of nuclear fuel and spent fuel.
        5.
        2021.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        대한민국 기상청에서 사용하고 있는 UM (Unified Model, UM) 모델의 국지예측시스템(Local Data Assimilation and Prediction System, LDAPS)은 수치모델 모의 시 대기경계층 유형에 따라 물리과정을 다르게 계산하기 때문에 이 과정을 검증하는 것은 모델의 정확도 향상에 중요하다. 따라서, 본 연구에서는 수치모델의 대기경계층 유형을 관측자료 를 기반으로 검증하였다. 관측자료를 기반으로 대기경계층 유형을 분류하기 위해서 보성 표준기상관측소에서 수행한 여름철 집중관측자료(라디오존데, 플럭스관측장비, 도플러 라이다, 운고계)를 활용하였으며, 2019년 6월 18일 부터 8월 17일 까지 61일 동안에 총 201회의 관측자료를 분석하였다. 또한 관측자료와 수치모델 결과가 다른 경우를 보면, 관측자료를 기반으로 한 대기경계층 유형 분류 결과에서 2유형으로 분류되는 사례가 수치모델에서는 1유형으로 분류된 사례가 53회로 가장 많이 나타났다. 그 다음으로는 관측자료를 기반으로 한 대기경계층 유형 분류 결과에서 5유형과 6유형 으로 분류되는 사례가 수치모델에서는 3유형으로 분류된 사례가 많이 나타났다(각각 24회, 15회). 관측결과와 수치모델 모의 결과가 일치하지 않은 사례는 모두 층적운 접합 여부 및 적운 모의 등 수치모델의 구름물리 부분의 모의 성능에 기인하여 발생한 것이라고 분석된다. 따라서, 대기경계층 유형 분류의 구름물리과정의 모의 정확도를 개선하면 수치모델 성능이 향상 될 것으로 판단된다.
        4,000원
        7.
        2021.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        PURPOSES : The purpose of this study is to contribute to the utilization of standards while considering the possible upgrade of a local system as a subject of the application. Therefore, this study aims to explore the possible application of LandInfra for a local road management (maintenance) system in the context of enabling the basis of 3D geospatial road information management in Korea. METHODS : Based on a review of related literature and international standards, an analysis of the current system is performed. After reviewing the LandInfra standard, an examination of corresponding classes between each data model (HMS and LandInfra) is performed for the mapping process. After the mapping process, a data model of the LandInfra-based HMS pavement data model is proposed. RESULTS : To apply the LandInfa to the HMS pavement part, an examination of each data model is performed. After this procedure, a LandInfra-based HMS pavement database schema is proposed in the context of enabling 3D geospatial road information management and maintenance, particularly for pavement management information. CONCLUSIONS : This paper presents how the LandInfra international open geospatial standard can be applied to the local road management system (HMS pavement part). As a result of this study, the LandInfra standard could be applied to the HMS; however, an encoding of the standard is required for conformance. Thus, further studies would be the encoding of the proposed data model for conformance with InfaGML encoding standards. In addition, a system prototype may be needed for complete application.
        4,000원
        12.
        2008.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Korea Astronomy and Space Science Institute (KASI), direct decendant of Korea National Astronomy Observatory, has been publishing Korean Astronomical Almanac since in 1976. The almanac contains essential data in our daily lives such as the times of sunrise, sunset, moonrise, and moonset, conversion tables between luni-solar and solar calendars, and so forth. So, we are planning to register Korean astronomical almanac data for national Standard Reference Data(SRD), which is a scientific/technical data whose the reliablity and the accuracy are authorized by scientific analysis and evalution. To be certificated as national SRD, reference data has to satisfy several criteria such as traceability, consistency, uncertainty, and so on. Based on similarity among calculation processes, we classified astronomical almanac data into three groups: Class I, II, and III. We are planning to register them for national SRD in consecutive order. In this study, we analyzed Class I data which is aimed to register in 2009, and presented the results. Firstly, we found that the traceability and the consistency can be ensured by the usage of NASA/JPL DE405 ephemeris and by the comparsion with international data, respectively. To evaluate uncertainty in Class I data, we solved the mathematical model and determined the factors influencing the calculations. As a result, we found that the atmospheric refraction is the main factor and leads to a variation of ±16 seconds in the times of sunrise and sunset. We also briefly review the histories of astronomical almanac data and of standard reference data in Korea.
        4,200원
        13.
        2016.06 KCI 등재 서비스 종료(열람 제한)
        Among agronomists, there appears to be a confusion in selecting among standard deviation (SD), standard error (SE) and confidence interval (CI) in reporting their results as figures and graphs. If there is a confusion in selection among them, there should also be difficulties in interpreting results published in peer-reviewed journals. This review paper aims to help researchers better suited for reporting their results as well as interpreting others by revisiting the definition of SD, SE and CI and explaining in plain words the concepts behind the formula. A variation among observation obtained from an experiment can be explained by the use of SD, a descriptive statistic. If one wants to draw an attention to a variation observed among plant germplasm collected from different regions or countries, SD can be reported along with the mean so that readers can get an idea how much variation exists in the particular set of germplasm. When the purpose of reporting experiment results is about inferring true mean of the population, it is advised to use SE or CI, both inferential statistics. For example, a certain chemical compound is to be quantified from plant materials, estimated mean with SD does not tell the range where the true mean content of the chemical compound would lie. It merely indicates how variable the measured values were from replications. In this case, it would be better to report the mean with SE or CI. The author recommends the use of CI over SE since CI is a sort of adjusted SE. The adjustment comes from t value that considers not only the probability but also n size.