• Journal of the Korean Society of Safety
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• v.32 no.5
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• pp.54-61
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• 2017

The purpose of this study is to develop standard reference materials for safety control of construction materials considering the required performance of standard materials including flow performance incorporating particles. The flow characteristics of concrete are very complicated depending on mixing proportions of constituent materials, admixtures, amount of mixing, type of mixer, time of mixing, temperature and so forth. Uncertainties and multidimensional properties of concrete have been evaluated through various studies but there are few researches for the development of standard reference material. In this study, based on the rheological concept, the flow performance of construction materials was evaluated to understand the properties of standard reference materials and was finally obtained representing materials which simulate the standard reference materials.

• Journal of the Korean Society of Safety
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• v.34 no.5
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• pp.111-118
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• 2019

Recently, a variety of special concrete structures have been designed in domestic and overseas construction markets and more advanced construction technology is required. Therefore, it is necessary to secure quantitative construction technology. For this purpose, it is essential to develop a standard reference material having a constant flow performance and quality to evaluate quantitative performance. On the other hand, the flowability of the concrete is greatly influenced by the flowability of the cement paste. Also, in consideration of design strength and workability, mix design is carried out at various mixing ratios according to the purpose of the site. Therefore, in this study, based on the derived components of standard reference materials for cement paste, we suggested mixing ratio of standard reference materials that can uniformly simulate the flow characteristics of cement paste according to W/C. As a result, it was found that the yield stress was determined by the ratio of water and glycerol but plastic viscosity was controled by limestone content. Finally, the ratio of standard reference materials to simulate the rheological range of cement paste by W/C was suggested.

• YAKHAK HOEJI
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• v.45 no.2
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• pp.227-236
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• 2001

The complexity and variability of both the biologicals and the bioassays used to test them led to the use of the reference standard- a sample of the product of defined purity and potency, against which all preparations of that product must be calibrated. In order to prepare and establish KFDA reference standard for recombinant human growth hormone (somatropin), somatropin substance was filled in ampoules in National Institute for Biological Standards and Control (NIBSC). The candidate KFDA reference standard for somatropin (designated as 98/674) was evaluated to determine the suitability of serving as a KFDA reference standard for somatropin by the collaborative study, in which 10 laboratories participated. Physicochemical analysis and in vivo bioassay were performed by direct comparison with the international somatropin standard 88/624. 98/674 was identified as somatropin by SDS-PAGE, IEF, peptide mapping, and HPLC. Determination of somatropin content by SE-HPLC yielded a mean estimate of 2.01 mg somatropin per ampoule. Data from the study also yielded mean values of 0.39 $\pm$ 0.26% for high molecular weight impurities by SE-HPLC and mean values of 2.13 $\pm$ 1.29% for somatropin related proteins by RP-HPLC. Estimates of relative potency by weight gain bioassay in the hypophysectomised rats showed that relative potency of KS 98/674 was 1.07 aganist IS 88/624. Based on the results of the collaborative study, the candidate reference standard for somatropin is suitable to serve as a KFDA reference standard for somatropin.

• Journal of the Korean Society for Library and Information Science
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• v.37 no.4
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• pp.131-149
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• 2003

Scientific/technical data whose reliability is authorized have to include physical/chemical constants, authorized property value or authorized scientific statistical values so that the scientists in the same field use them continuously and repeatedly for their research. The data also have to be managed as Standard Reference Data that will be used in other area nationwide by analyzing, evaluating and authorizing the accuracy and reliability of the information with scientific methods. This study suggests a plan for establishing the National Center for Standard Reference Data as well as a necessity for managing the data produced in research process as a national Standard Reference Data. Also, a prototype of research information system for measurement standards is developed and described in detail for research information for measurement standard to be used as a reference data, then a plan to managing national reference data is suggested, in addition.

• Journal of Advanced Navigation Technology
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• v.20 no.6
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• pp.580-587
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• 2016

In the purpose of suggesting the necessity and proper method of providing the standard reference material for acquiring the aircraft pilot license, this study provides the FAA and ROKAF case study, and positively analyzes the materials of 178 pilots and student pilots who acquired the aircraft pilot license. The result of case study shows that compared to the case of Korea which the restriction on the standard reference material providing exists, the FAA(Federal Aviation Administration) and ROKAF are currently providing the standard reference material. Additionally, the result of positive analysis indicates the fact that the necessity of standard reference material providing is well recognized and its importance also found to be remarkably high. These results represent that the standard reference material providing is necessary for training competent aircraft pilots. Also, this will mitigate the current shortage of aircraft pilots due to the rapid growth of air transportation industry, and this will play an important role in preventing diverse aircraft-related accidents.

• Nuclear Engineering and Technology
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• v.48 no.2
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• pp.299-303
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• 2016

Prompt gamma activation analysis using a thermal neutron-guided beam at Japan Atomic Energy Agency JRR-3M was applied for the precise determination of Si in silicon nitride ceramic reference materials [Japan Ceramic Reference Material (JCRM) R 003]. In this study, the standard addition method coupled with internal standard was used for the nondestructive determination of Si in the sample. Cadmium was used as internal standard to obtain the linear calibration curves and to compensate for the neutron beam variability. The analytical result of determining Si in JCRM R 003 silicon nitride fine powder ceramic reference materials using prompt gamma activation analysis was in good agreement with that obtained by classical gravimetric analysis. The relative expanded measurement uncertainty (k = 2) associated with the determined value was 2.4%.

• Journal of Korean Society for Quality Management
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• v.47 no.2
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• pp.315-325
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• 2019

Purpose: The purpose of this study was to propose useful standards evaluation method using standards networks by analyzing the relationship between normative references citation information list. Methods: The collected data through the survey were analyzed using social network analysis. The measurement tools used for this study were divided into three dimensions such as certificate standard, normative reference and degree centrality. Results: The results of this study are as follows; regarding the influence of standard information, It is meaningful that the research using normative reference item among the bibliography information that the standard itself possesses. The analysis of social network analysis data of population standard, normative reference and the correlation analysis with sales, a variable representing actual utilization performance, suggested the importance of the standard and how to evaluate it. Conclusion: In prioritizing standard maintenance, more efficient management will be possible if centrality figures of standard network information are analyzed and used for standard maintenance.

• Korean Journal of Community Nutrition
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• v.3 no.4
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• pp.533-541
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• 1998

This study compares the growth performance(weight-for-age Z-score, height-for-age Z-score, weight-for-height Z-score) of one- to three- month-old Korean infants(n=232) with the Korean standard(1994) and NCHS reference(1983). The weight-for-age Z-scores(WAZ) by the Korean standard were -2∼1,5 for males and -3∼1 for females. The NCHS reference, WAZ results were -1∼2.5 and -2.5∼3.5 for males and females, respectively. The WAZ compared Korean standard showed no subjects with overnutrition. But 1.3% of the infants showed signs of malnutrition. Comparison with NCHS reference revealed that 0.4% of the infants were malnourished and 7.0% of the infants were overnourished. The WAZ of formula-fed infants were distributed higher than breast-fed infants, but that was not significant. The height-for-age Z-score(HAZ) by the Korean standard were -4.5%∼1.5% for males and -4∼1.5% for females. According to the NCHS reference, HAZ were -2.5%∼2.5% and -3∼3 for males and females, respectively. When the WAZ was compared with the Korean standard, there was no overnutrition but 16% of the infants showed signs of malnutrition. The NCHS reference, revealed that 6.9% of the infants were malnourished and 1.8% of the infants were ovemourished. The weight-for-height Z-scores(WHZ) by the Korean standard were -2∼5 for males and -2.5∼5 for females. The NCHS reference WAZ scores were -1∼4 and -1.5∼4.5 for males and females, respectively. When the WHZ was compared with the Korean standard, 2.2% of infants were malnourished and 19.5% were overnourished. There were no malnourished subjects according to the NCHS reference and 19.1% of the infants were overnourished. When the three Z-scores are considered together, 92.0% of the infants should a normal growth status, there was no malnutrition, and 8.0% of the infants were overnourished. The growth performance was evaluated differently according to the type of standards. Thus, it is necessary to set proper growth standards for infants, according to which classification of feeding methods is chosen. A longterm and careful assessment of infants's growth performances to develop any group of standards.

• Korean Journal of Radiology
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• v.24 no.2
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• pp.155-165
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• 2023

Objective: Little is known about the effects of using different expert-determined reference standards when evaluating the performance of deep learning-based automatic detection (DLAD) models and their added value to radiologists. We assessed the concordance of expert-determined standards with a clinical gold standard (herein, pathological confirmation) and the effects of different expert-determined reference standards on the estimates of radiologists' diagnostic performance to detect malignant pulmonary nodules on chest radiographs with and without the assistance of a DLAD model. Materials and Methods: This study included chest radiographs from 50 patients with pathologically proven lung cancer and 50 controls. Five expert-determined standards were constructed using the interpretations of 10 experts: individual judgment by the most experienced expert, majority vote, consensus judgments of two and three experts, and a latent class analysis (LCA) model. In separate reader tests, additional 10 radiologists independently interpreted the radiographs and then assisted with the DLAD model. Their diagnostic performance was estimated using the clinical gold standard and various expert-determined standards as the reference standard, and the results were compared using the t test with Bonferroni correction. Results: The LCA model (sensitivity, 72.6%; specificity, 100%) was most similar to the clinical gold standard. When expert-determined standards were used, the sensitivities of radiologists and DLAD model alone were overestimated, and their specificities were underestimated (all p-values < 0.05). DLAD assistance diminished the overestimation of sensitivity but exaggerated the underestimation of specificity (all p-values < 0.001). The DLAD model improved sensitivity and specificity to a greater extent when using the clinical gold standard than when using the expert-determined standards (all p-values < 0.001), except for sensitivity with the LCA model (p = 0.094). Conclusion: The LCA model was most similar to the clinical gold standard for malignant pulmonary nodule detection on chest radiographs. Expert-determined standards caused bias in measuring the diagnostic performance of the artificial intelligence model.

• Journal of Korean Library and Information Science Society
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• v.39 no.2
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• pp.147-167
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• 2008

The purpose of the research is to 4ind out its problems and to suggest its solution by investigating and analyzing the present condition of the Virtual Reference Shelves establishment in Chinese university libraries. To achieve the goal, this study establishes theoretical foundations for virtual reference shelves. The evaluation standard was set up on the basis of this theoretical foundation. The 38 university libraries, which had been selected in 985 Project were analyzed by this evaluation standard. The results are used to justify the cooperative establishment for virtual reference shelves.