• Economic and Environmental Geology
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• v.44 no.2
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• pp.95-107
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• 2011

The Hwangsan volcanic rocks, hosting the Moisan epithermal Au-Ag deposit arc widely distributed throughout the Seongsan district, and associated with large hydrothermal alteration. They were analyzed as the Moisan and around voleanic rocks, and most of them show dacitic to rhyolitic compositions. Hydrothermal alteration related to epithermal system causes the host rocks to show the geochemical variation due to high mobility of alkali elements. These features can be applied for quantitative estimates of alteration intensity. Alteration intensity of volcanic rocks from the Moisan ranges from subtle to intense, based on AI vs. $Na_2O$ diagram. The pattern that ($CaO+Na_2O$) content decrease with increasing $K_2O$ content results from sericitic alteration, in which hydrothermal fluids continually provide $K^+$ into country rocks but remove $Ca^{2+}$ and $Na^{2+}$ of feldspars within country rocks. The decrease of ($CaO+Na_2O$) with decreasing $K_2O$ in some samples from the Moisan may be caused by advanced argillic alteration that all alkali elements are entirely removed from country rocks by acid hydrothermal fluids. Two alteration trends, based on Al and CCPI alteration indices suggest both sericitic alterations of feldsaprs to illite and sericite+chlorite$^{\circ}{\ae}$pyritc alteration of high Mg and Fe activities. Trace and Rare Earth Elements patterns show the similar geochemical variation related to hydrothermal alteration. Of LIL elements, strong depletion of $Sr^{2+}$, substituting for $Ca^{2+}$ in feldspars, appears to be resulted from removal of $Ca^{2+}$, during replacement of feldspars to alumino-silicates or phyllo silicates minerals by hydrothermal fluids. Relatively low total REEs contents (Moisan: 119-182 ppm; Seongsan: 111-209 ppm) and gently negative slopes suggest that significant mobility of LREEs appear to occur during hydrothermal alteration.

• Phonetics and Speech Sciences
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• v.14 no.4
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• pp.57-66
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• 2022

In this study, the definition of "digital therapeutics" was clarified by examining related studies, and the development trend of digital therapeutics at the domestic level was investigated. Further, research data and technologies applied to various communication disorders since 2015 were analyzed. From all these, digital therapeutics can be defined as software that can support evidence-based treatment when used on patients to prevent, manage, and treat disorders With huge investments and research efforts increasingly made in the field of digital therapeutics, 17 of the 22 studies examined were on digital therapeutics applied in the treatment of language disorders. In the research papers examined, the technologies applied were virtual reality and augmented reality, with augmented reality used in most cases. The effects of applying digital treatment were positive, and most studies focused on content development in relation to the development of digital treatment, although one study was conducted for app development. Future studies could examine the application of digital therapeutics to more diverse communication disorder subjects. Active government support is expected in developing more sophisticated software that can be applied using a wider range of technologies in the field of digital therapeutics to treat more communication disorders.