• The Journal of the Petrological Society of Korea
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• v.19 no.4
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• pp.255-267
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• 2010

The primary utilization of recently improved (U-Th)/He thermochronometry is to reveal the low-T thermal histories of shallow crustal sections or transient episodes (such as wildfires or meteorite impacts) because of the high sensitivity of He diffusion to temperature in host minerals. In this contribution, we present reviews and perspectives regarding how this method can be used to characterize the ejection-related shock metamorphism of Martian meteorites. The temperature conditions of shock metamorphism can be constrained through shock recovery experiments, paleomagnetism, and $^{40}Ar/^{39}Ar$ and (U-Th)/He dating. The most reliable constraints can be deduced when these independent approaches are combined. However, the thermal history of the ALH84001 Martian meteorite has been under serious debate because the different methods have yielded contrasting results. Recent work has shown how single-grain (U-Th)/He and $^{40}Ar/^{39}Ar$ dating, two noble-gas based thermochronometries with different T sensitivities, can be used to resolve this issue, providing a good example for future research on other meteorites.

• Journal of the Mineralogical Society of Korea
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• v.20 no.4
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• pp.231-245
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• 2007

The forged iron axe of the middle 3rd Century found in the No. 2 wood-framed tomb from the Hwangseongdong site, Gyeongju is rectangular on the plane level. The iron axe shines in met-allic luster, which is light grey with pale creamy tint. The result of X-ray diffraction analysis shows that the axe consists of magnetite and geothite, which can explain why the composition and texture of the original ore has been kept intact. There are fine-grained quartz, calcite, mica, magnetite, amphibole, unknown tungsten minerals, pyroxene and olivine inside the axe. Those must be the impurities that they failed to remove in the thermal treatment process. Generally, the iron axe consists mainly of pearlite texture coexisting ferrite and cementite, and show high carbon contents with homogeneous distribution. It can be interpreted the axe was carburized after the material was made to resemble pure iron. The decarbonization work didn't go well along the process marks. Crude ores of the iron axe are possible utilized by magnetite from the Ulsan mine on the basis of the occurrences and inclusions. It's estimated that the original ore was bloom produced in low-temperature reduction and formed around in $727^{\circ}C$, which is eutetic temperature.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.1
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• pp.304-312
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• 2019

Service companies are making constant efforts to gain positive business performance such as customer satisfaction, quality improvement, and valuable management. Compared to other industries, service companies are highly dependent on workers for responding to customers and satisfying various customer needs in terms of business content and type. Thus, the attitude, given, environment, and capacity of the workers who supply service and serve customers are important factors that directly and indirectly influence customer satisfaction and performance. To enhance the performance of organizations and gain competitive advantage, it is important to provide the various forms of social support for workers as service suppliers. In this sense, active interests including the development of personal competence, support for working environment, and providing chances for the development of new services are significant. This study is a follow-up study on the influence of social support for positive psychological capital, creativity, and work performance of service workers. Among the service process matrix, this study targets the workers involved in mass service fields and seeks to examine how support for co-worker influences the performance through self-efficacy. No empirical analysis has examined workers involved in mass service fields. Thus, this study aims to take an approach different from that of previous studies and to suggest more effective human resource management strategies for enhancing the competitiveness of service companies and provide related implications.

• Korean Journal of Microbiology
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• v.54 no.4
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• pp.343-353
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• 2018

Our previous research demonstrated the essential role of the xenB gene in stress response to RDX by using Pseudomonas sp. HK-6 xenB knockout. We have extended this work to examine the cellular responses and altered proteomic profiles of the HK-6 xenA knockout mutant under RDX stress. The xenA mutant degraded RDX about 2-fold more slowly and its growth and survival rates were several-fold lower than the wild-type HK-6 strain. SEM revealed more severe morphological damages on the surface of the xenA mutant cells under RDX stress. The wild-type cells expressed proportionally-increased two stress shock proteins, DnaK and GroEL from the initial incubation time point or the relatively low RDX concentrations, but slightly less expressed at prolonged incubation period or higher RDX. However the xenA mutant did not produced DnaK and GroEL as RDX concentrations were gradually increased. The wild-type cells well maintained transcription levels of dnaA and groEL under increased RDX stress while those in the xenA mutant were decreased and eventually disappeared. The altered proteome profiles of xenA mutant cells under RDX stress also observed so that the 27 down-regulated plus the 3 up-regulated expression proteins were detected in 2-DE PAGE. These all results indicated that the intact xenA gene is necessary for maintaining cell integrity under the xenobiotic stress as well as performing an efficient RDX degradation process.

• Journal of Convergence for Information Technology
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• v.11 no.3
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• pp.185-193
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• 2021

The purpose of this study is to seek out effective policy measures for improving the working environment and improving the supply and demand of nursing manpower in Korea, thereby improving the quality of nursing and creating a high-quality work environment to present a plan to secure adequate supply and demand for nursing manpower. To this end, we have looked at ways to secure effective nursing manpower through literature related to Japanese nursing manpower policy, which has similar health systems to Korea. Japan has established a nursing manpower supply policy since 1974, and is making efforts to improve the working environment and re-employment of idle nursing personnel due to frequent turnover and retirement. As a result of these efforts, the turnover rate of new nurses less than one year in Japan decreased to 7.5%, while the rate of new nurses in Korea was 33.9%. In addition, it is possible to consider ways to encourage medical institutions that have actively promoted and hired idle personnel through various incentives and financial support at the central and local levels.

• Journal of Industrial Convergence
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• v.19 no.3
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• pp.1-12
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• 2021

Even though there have been so much practical interests in industry, the relevant empirical researches are not sufficient. In this study, we try to identify the problems of matrix organization structure in the semiconductor industry and make suggestions for improvements. Also, we try to find out whether there are differences in the perceptions of the problems among ranks and teams. This study was conducted to the researchers in the matrix organization structure of the H-corp. research institute. The problems we found are as follows. The researchers agreed that the matrix organization structure is appropriate when highly professional members for the development of next-generation semiconductors are participated in the projects. They showed strong wills to participate and succeed in projects. However, the researchers felt that the equipments and manpowers were not enough and too much tasks and workloads were assigned to both the managers and members Also, in an open ended question, the researchers pointed out the problems of the matrix organization structure such as 'weak project manager's authority', 'communication and teamwork issues', 'non-obvious work priorities', 'compensation and benefit system', 'lack of research manpower and equipment'. From the strengths and weaknesses of the matrix organization structure of the semiconductor industry, we provide some suggestions for improvements.

• Journal of Digital Convergence
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• v.19 no.8
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• pp.319-325
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• 2021

With the advancement of wireless technology and the rapid growth of the infrastructure of mobile communication technology, systems applying AI-based platforms are drawing attention from users. In particular, the system that understands users' tastes and interests and recommends preferred items is applied to advanced e-commerce customized services and smart homes. However, there is a problem that these recommendation systems are difficult to reflect in real time the preferences of various users for tastes and interests. In this research, we propose a Fuzzy-AHP-based movies recommendation system using the Gated Recurrent Unit (GRU) language model to address a problem. In this system, we apply Fuzzy-AHP to reflect users' tastes or interests in real time. We also apply GRU language model-based models to analyze the public interest and the content of the film to recommend movies similar to the user's preferred factors. To validate the performance of this recommendation system, we measured the suitability of the learning model using scraping data used in the learning module, and measured the rate of learning performance by comparing the Long Short-Term Memory (LSTM) language model with the learning time per epoch. The results show that the average cross-validation index of the learning model in this work is suitable at 94.8% and that the learning performance rate outperforms the LSTM language model.

• Korean Journal of Remote Sensing
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• v.39 no.6_2
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• pp.1529-1539
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• 2023

The data from Geostationary Ocean Color Imager-II (GOCI-II), which observes the color of the sea to monitor marine environments, undergoes various correction processes in the ground station system, producing data from Raw to Level-2 (L2). Quality issues arising at each processing stage accumulate step by step, leading to an amplification of errors in the satellite data. To address this, improvements were made to the GOCI-II ground station system to measure potential optical quality and geolocation accuracy errors in the Level-1A/B (L1A/B) data. A newly established Radiometric and Geometric Performance Assessment Module (RGPAM) now measures five optical quality factors and four geolocation accuracy factors in near real-time. Testing with GOCI-II data has shown that RGPAM's functions, including data processing, display and download of measurement results, work well. The performance metrics obtained through RGPAM are expected to serve as foundational data for real-time radiometric correction model enhancements, assessment of L1 data quality consistency, and the development of reprocessing strategies to address identified issues related to the GOCI-II detector's sensitivity degradation.

• Korea journal of population studies
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• v.29 no.2
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• pp.1-26
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• 2006

This paper examines the interplay among changes in socioeconomic conditions, population policies, and fertility decline during $1960{\sim}2000$ in South Korea. Period-parity-progression-ratios (PPPR) are calculated using 2% samples of Population Census with the implied distribution of completed family size. The total fertility rate based on PPPR declined from 5.21 in 1960 to 2.76 in 1980, and 1.69 in 2000. The family planning programs were successful in meeting the needs of families that wanted to prevent further childbearing after having achieved the desired family size during $1960{\sim}1970$. The 1980s mark two important landmarks: achievement of replacement fertility and emergence of high sex ratio at birth. In the 1990s the "quality and welfare" approach was emphasized. In 2000s, South Korea's fertility is one of the lowest in the world. In response to this, in 2005, the Government adopted a new population policy with the goal of increasing the total fertility level to 1.6 by 2010. The results of this study indicate that proportion of women who would have no children at all throughout their reproductive life span increased substantially from 10% in 1995 to 16% in 2000, with a sharp increase since 1997. Thus, pro-natal programs need to address the problems associated with marriage and having the first child. Towards that, it is important that work and family life become more compatible.

• Journal of Conservation Science
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• v.26 no.1
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• pp.33-41
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• 2010

The archival objects are tangible evidence reflecting public work as forming archives which are administrative, historic, symbolic, cultural and artistic value. They are produced from the various countries so that they have different material and manufacture techniques. However there are difficulties in conservation and management because the material investigation and conservation management system are not established. Therefore this research presents fundamental data for the efficient conservation management by material investigation and condition check metal archival objects. Among the public official presents made of metal, 12 pieces which are discoloration, oxidation, loss or crack are chosen for this research. In order to examine extensive condition of metal archival objects, the condition check card used from the domestic museum and the national museum in Japan are collected and then the new check card is produced. X-ray is used to know the making technique, binding means between different material. Portable-XRF is also used for the chemical composition analysis of metal archival objects, and then classifying respectively according to their material. As a result of condition check, it is possible to investgate the appearance character, deteriorated parts and weak parts of structure. Also P-XRF could find out the composition of metal archival objects which is different from existing condition check card. Therefore the research results can be used as fundamental data for further conservation and management as well as long-term conservation.