• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.1145-1146
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• 2008

Failures of equipments are linked directly to extensive damages of human lives or financial losses from the increasing uses of railway signaling equipments utilizing computers. Then safety organizations have to establish for guaranteeing safety during the system life-cycle. In this paper, we examine the relationship between railway signaling standards and other safety standards for safety meaning establishment.

• Bulletin of the Korean Chemical Society
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• v.29 no.11
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• pp.2125-2128
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• 2008

• Journal of Elementary Mathematics Education in Korea
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• v.23 no.1
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• pp.19-41
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• 2019

In this study, we present an analysis framework based on the 2015 revised curriculum to analyze how mathematical contents and achievement standards for domains of numbers and computations have changed in the curriculum of elementary mathematics in Korea. Based on this, we classified the achievement standards by type and investigated their characteristics. The achievement standards for numbers and computations can be divided into the successive, the extinctive, and the additive achievement standards depending on their characteristics. The successive achievement standards are the ones that have consistently existed without being removed from the 1-st curriculum to the latest revision in 2015. The extinctive achievement standards are the ones that have been removed at some point during the revisions of nine times and do not remain in the current revision in 2015. The characteristics of the extinctive achievement standards were analyzed to be different before and after the 4-th curriculum. The additive achievement standards refer to the ones that have been newly added to the curriculum or that have been removed at a certain moment but added back in later and thus exist in the current revision in 2015. The characteristics of each type according to the changes of the achievement standards can be thought to be the results that the revision for the mathematics curriculum in Korea has been faithfully conducted. Based on the results of this study, we suggest some implications for organizing the achievement standards in the future curricular development.

• Proceedings of the Korean Vacuum Society Conference
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• 1995.06a
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• pp.51-51
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• 1995

• Proceedings of the Korean Vacuum Society Conference
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• 1995.06a
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• pp.127-127
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• 1995

• Proceedings of the Korean Vacuum Society Conference
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• 1995.06a
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• pp.155-155
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• 1995

• Proceedings of the Korean Vacuum Society Conference
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• 1997.02a
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• pp.29-30
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• 1997

• Proceedings of the Korean Vacuum Society Conference
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• 1993.02a
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• pp.89-89
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• 1993

• Proceedings of the Korean Vacuum Society Conference
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• 1997.02a
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• pp.156-157
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• 1997

• Analytical Science and Technology
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• v.33 no.2
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• pp.68-75
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• 2020

We have developed 10 μmol/mol nitrogen and oxygen certified reference materials (CRMs) in helium, as a SI-traceable gas standard for a quantifying of impurities in pure gases for the first time in Korea. The standard gas mixtures of nitrogen and oxygen were prepared in 5000 μmol/mol and sequentially were diluted to 250 μmol/mol and 10 μmol/mol according to the gravimetric preparation. In each dilution step, two cylinders of CRMs were prepared. The verification of internal consistency among the prepared gas mixtures was performed by using GC-TCD. The amount fractions and those expanded uncertainties (k = 2) of nitrogen and oxygen in the standard gas mixtures were (10.12 ± 0.08) μmol/mol and (10.18 ± 0.08) μmol/mol for nitrogen, and (9.88 ± 0.06) μmol/mol and (9.94 ± 0.06) μmol/mol for oxygen, respectively. We have conducted a purity assessment of two commercial helium gases using developed CRMs. As the results of the purity assessment, nitrogen and oxygen were detected by (1.66 ± 0.03) μmol/mol and (0.31 ± 0.02) μmol/mol, respectively, as the impurities in one of the pure helium.