• Proceedings of the Mineralogical Society of Korea Conference
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• 2003.05a
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• pp.54-54
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• 2003

The metasedimentary rocks together with various granitoids are the main constituents in Taebaeksan gneiss complex, northern Yeongnam Massif. Chemical compositions of sedimentary rocks may reflect the nature of the provenance and could be crucial for understanding the evolution of early continental crust. Previous workers have suggested that the provenance and tectonic studies based on the geochemistry of sediments are applicable to the Precambrian samples. In this study we analyzed the major, trace and REE elements of metasedimentary rocks to understand their provenance and tectonic setting during sedimentation. The overall geochemical characteristics of metasedimentary rocks are similar to those of average shale of the post-Archean. Major element chemistry indicates mature and sorted nature of the sediments. The degree of weathering in the source rocks the is not uniform, as inferred from a large scatter in chemical indices of weathering (CIW). The immobile trace elements such as Th, Sc, and REE can be used to discriminate various sedimentary processes. The Th/sc ratios (0.9 - 4.4) are larger than those of the upper crust and average shale, suggesting that the felsic source predominates. The contents of Ni and Cr and the variations in the ratio of compatible to incompatible elements are similar to the average post-Archean shale. Uniform chondrite-normalized REE pattern with the LREE enrichment (LaN/SmN = 4.9 ${\pm}$ 0.4) and slight negative Eu anomalies (Eu/Eu$\^$*/ = 0.7 ${\pm}$ 0.1) also support this observation. The presence of negative Eu anomaly indicates that intracrustal igneous processes involving plagioclase separation have affected the provenance rocks. The LREE enrichment implies the major role of felsic rocks in source rocks. The eNd (1.9 Ga) values of metasediment rocks vary from 9.4 to 6.7, corresponding to TDM of 2.9 - 2.7 Ga. On the other hand, the 147Sm/144Nd ratios are 0.1079 - 0.1101, corresponding to typical tettigenous sediments. The geochemical features of metasedimentary rocks such as high abundances of large ion lithophile elements, high ratios of Th/Sc and La/Sm, commonly high Th/U ratios, negative Eu anomalies, and negative eNd, suggest a provenance consisting virtually entirely of recycled upper continental crust in passive margin environment. Tectonic discrimination diagrams based upon major element compositions also support this suggestion. In conjunction with igneous activity and metamorphism in the convergent margin setting at 1.8 - 1. 9 Ga, the transition from passive margin to active margin characterize the Paleoproterozoic crustal evolution in northern Yeongnam Massif.

• Applied Chemistry for Engineering
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• v.16 no.6
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• pp.809-814
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• 2005

In this work, the thermal properties of epoxy coating system on the liner plate in the containment structure of nuclear power plants had been examined by irradiation and design basis accident (DBA) conditions. The effect of immersion in hot water on adhesion strength of the coating system had been also studied. The glass transition temperature ($T_g$) and thermal stability of ET-5290/carbon steel A 32 epoxy coating systems were measured by DSC and TGA analyses, respectively. Contact angle measurements were used to determine the effect of immersion on the surface energetics of epoxy coating system, with a viewpoint of surface free energy. Adhesion tests were also executed to evaluate the adhesion strength at interfaces between carbon steel plate and epoxy resins. As a result, it was found that the irradiation led to an improvement of internal crosslinked structure in cured epoxy systems, resulting in significantly increasing the thermal stability, as well as the $T_g$. Also, the immersion in hot water made a role in the post-curing of epoxy resins and increased the mechanical interlocking of the network system, resulting in increasing the adhesion strength of the epoxy coating system.

• Journal of the Geological Society of Korea
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• v.54 no.6
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• pp.657-675
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• 2018

The apparent thickening of the subducting slab in the shallow lower mantle has been attributed to slab buckling. However, the scaling laws have not been quantitatively evaluated for the buckling behavior of the subducting slab when phase transformations are considered. Thus, two-dimensional dynamic subduction experiments are formulated to evaluate the effect of phase transformations on the buckling behavior of the subducting slab. The model calculations show that the phase transformation from olivine to wadsleyite at a depth of 410 km plays an important role in the development of slab buckling; increased slab pull due to the endothermic phase transformation accelerates slab sinking in the upper mantle and the subducting slab reaches the lower mantle in a shorter time than that of the experiments without the phase transformation. However, the phase transformation from ringwoodite to perovskite plus $magnesiow{\ddot{u}}stite$ at a depth of 660 km retards slab sinking into the lower mantle and the subducting slab tends to be accumulated in the transformation (transition) zone. Buckling analyses show that the scaling laws predict the buckling amplitude and period of the subducting slab with small relative errors even if the phase transformations are considered. The universal phenomenon of the slab buckling can explain apparent slab thickening in the shallow lower mantle and transformation zone under the subduction zones such as Java-Sunda and Northeast Japan. In addition, the buckling behavior of the subducting slab may be related to the periodic compressions and extensions in the Cretaceous Gyeongsang basin.

• Journal of Technology Innovation
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• v.28 no.4
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• pp.151-163
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• 2020

The routinized tasks in the post-COVID era are to be replaced by digital technologies, while there is a high possibility that digital transformation technologies and non-routinized tasks have strong complementarity. In particular, looking at the job composition within Korea's industries, the intensities of routinized works appear to be continuously rising. It suggests that the potential side effects on the labor market caused by the acceleration of digital transformation in the post-COVID era will be greater within Korean innovation system. With this background, this study aims to provide a conceptual framework for dealing with potential crises such as, job polarization and widening gaps between workers in terms of economic earnings, based on an in-depth understanding of the inherent properties of digital transformation that will lead to structural changes in our economic and social system. In particular, focusing on the interaction between digital transformation technology and learning in the post-COVID era, this study attempts to redefine the role of the innovation policy for making a successful transition to a new equilibrium state. In addition, this study examines the institutional conditions of the Korean innovation system which affect the creative learning activities of economic actors to draw policy implications for establishing future-oriented innovation policy. Based on these approaches, this study highlights the importance of coevolution between the skills demand and skills supply to spur inclusiveness of Korean innovation system in the post-COVID era.

• Knowledge Management Research
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• v.22 no.1
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• pp.85-103
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• 2021

While there is a rapid transition to smart work due to COVID-19, not many studies have measured the changes in organizational culture after firm-wide institutionalization of smart work. Through a questionnaire and a series of stakeholder interviews, this study examined how and to what extent employees' perception of organizational culture changed after the introduction of smart work in a large leisure service company H in South Korea. The working culture of the organization is measured as the changes in the organizational members' perception on seven dimensions: strategic innovativeness, organizational flexibility, fair human resource management, rational decision making processes, organizational vitality, trustful collaboration, proactive leadership. The results demonstrated that, after the introduction of smart work, the organizational members' perception on strategic innovativeness, organizational flexibility, organizational vitality, trustful collaboration have declined significantly while the changes in fair human resource management, rational decision making processes, and proactive leadership are insignificant. Though found to be insignificant, follow up interviews revealed that participants think that the role of management leadership is very critical for the smart work systems to be institutionalized successfully. While the smart work may have different effects depending upon industry or organizational characteristics, this study present a case for changes in organizational culture after institutionalizing smart work. Implications are discussed with further research issues at the end.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.1
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• pp.30-38
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• 2022

According to the United Nations Convention on the Law of the Sea (Article 94), the flag state must fulfill its overall role to ensure maritime safety and operate the ship inspection system as a related measure. The Korean government (Ministry of Ocean and Fisheries) has implemented policies for reducing marine accidents to promote maritime safety; however, the target goal has not been achieved. The ship inspection system is a measure to prevent marine accidents, and for the effective operation of the system, a sufficient understanding of the origin of the ship inspection system is required. In this study, the trend of the international ship inspection system was identified by analyzing ship inspection system origins and the history of the system's paradigm shift. The recent international ship inspection system paradigm confirms international standardization and the active safety management of ship companies are becoming increasingly prominent. Based on this, the introduction of the 'PDCA cycle-based self-inspection system' is presented to the current domestic ship inspection system. This is a new type of inspection system that establishes the roles of interested parties based on the basic philosophy of the ISO 9000 series to improve the ef ectiveness of maritime safety. Additionally, the necessity for a non-face-to-face ship inspection system has emerged because of the COVID-19 pandemic. Hence, the transition to a 'mobile application-based ship inspection system' is proposed to accommodate the rapid development of information communications technology.

• Journal of the Korean earth science society
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• v.43 no.1
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• pp.224-235
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• 2022

This study aimed to confirm the status of media reports on space hazards using topic modeling analysis of media articles that are related to space hazards for the past 12 years. Therefore, Latent Dirichlet Allocation (LDA) analysis was performed by collecting over 1200 space hazards articles between 2010 and 2021 on solar storm, artificial space objects, and natural space objects from BIGKins news platform. The articles related to solar storm focused on three topics: the effect of solar explosion on satellites; effect of solar explosion on radio communication in Korea, centered on the Korean Space Weather Center; and relationship between aircrew and space radiation. The articles related to artificial space objects focused on three topics: the threat of space garbage to satellite and space stations and the transition of useful objects into space junk; the relationship between space garbage and humanity as shown in movies; and the effort of developed countries for tracking, monitoring, and disposing of space garbage. The articles related to natural space objects focused on two topics: International Space Agency's tracking and monitoring of near-Earth asteroids and the countermeasures of collisions, and the evolution and extinction of dinosaurs and mammals, with a focus on the collisions of asteroids or comets. Therefore, this study confirmed that domestic media play a role in conveying dangers of space hazards and arousing the attention of public using a total of eight themes in various fields such as society and culture, and derived education method and policy on space hazards.

• International Journal of Computer Science & Network Security
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• v.22 no.9
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• pp.123-130
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• 2022

Modernization of the educational sector requires globalization, democratization, and the transition to an information technology society. The main goal of education at the present stage is to solve the problem of ensuring the priority of the development of education and science. In modern conditions, the quality of training of qualified specialists is becoming particularly relevant. The great role of teacher education is emphasized by its main goal, which is to train specialists who can ensure the versatile and innovative development of a person as a person and the highest value of society, its mental, physical and aesthetic abilities, high moral qualities, and, consequently, the enrichment on this basis of the intellectual, creative and cultural potential of the people. Among the strategic tasks of modernizing higher education is to ensure informatization of the educational process and access to International Information Systems. The essence of the concept of multimedia is clarified. In the context of media education, multimedia lists a number of functions: informational, interpretive, cultural, entertainment, and educational. The need to meet the needs outlined in the article in the conditions of informatization of the educational process requires the teacher to have knowledge and skills in the field of multimedia pedagogical technologies, knowledge of advanced methods and means of modern science. It is considered what relevant concepts of media education have been developed and are being developed in Ukraine and form an important basis for the modernization of education, which will contribute to the construction of an information society in the country and the formation of civil society. Distance learning is considered - the most democratic form of education that allows broad segments of society to get an education. Distance learning methods are used in higher education institutions, in school education, in the system of advanced training of teachers, in the system of training managerial personnel.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.36 no.3
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• pp.280-285
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• 1991

The rice culture techniques of the ancient China which have played a key role directly and indirectly, in development of ancient farming and its techniques of Korea, were established before Christ in terms of dry-farming and the spirit of the farming-first principle. Especially techniques of rice culture were developed by cultivation methods for deep plowing, storage of water and preservation use of soil fertility. Therefore, the techniques of transplanting methods, seeding in rows, use of iron-made farming tools and dam construction for irrigation were advanced. And rice varieties were differentiated to avoid disasters or to supply of rice for various uses in many areas. Also, because north China was the origin of Chinese agriculture in which population density was low and flat land was wide that were the cradle of Chinese agriculture, ‘Hwayungsunubeob’(firing and drawning weed control method) and fallowing were quickened as intensive techniques of rice culture. In connection with the view of agricuture with 'the theory of the cosmic dual forces and the five primary substances' of Han Mooje and Chamwye scholars, the techniques of seeding and selection of crops were gradually developed. From ‘Jeminyosul’ of the 6th century to ‘Wangjongnongseo’ of the 14th century, the techniques of rice culture have been developed continuously and additively, but were not improved thereafter Won dynasty. From this point of time, the time of agriculture in the end of Koryo age and by ‘Nongsajiksul’ were initiated.

• Clean Technology
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• v.29 no.3
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• pp.163-171
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• 2023

Hydrogen has been gaining a lot of attention as a possible clean energy source that can aid in reaching carbon neutrality. Currently, hydrogen production has relied on the steam reforming of fossil fuels. However, due to the carbon dioxide emissions caused by this process, hydrogen production based on the steam reforming of bio-oil derived from biomass has been proposed as an alternative approach. In order to use this alternative approach efficiently, one of the key issues that must be overcome is that the complexity of bio-oil, which has a large molecular weight and diverse functional groups of hydrocarbons, promotes the catalytic deactivation of nickel-based catalysts. In this review, research efforts to improve nickel-based catalysts for the steam reforming of bio-oil have been discussed in terms of the active phase, support, and promoters. The active phases are involved in activating C-C and C-H bonds of high-molecular-weight hydrocarbons, and noble and transition metals can be utilized. In terms of the support and promoters, the catalytic deactivation of Ni-based catalysts can be inhibited by utilizing reactive lattice oxygen for support or by suppressing the acidity. The development of active and stable Ni-based reforming catalysts plays a critical role in clean hydrogen production based on bio-oils.