• Economic and Environmental Geology
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• v.55 no.6
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• pp.583-596
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• 2022

The rock surface of Bangudae petroglyphs is mainly dark brown hornfelsified shales by contact metamorphism. The surface form a weathered layer of a invariable depth, and there is a difference with mineral and chemical composition between weathered and non-weathered layers. Surface of the petroglyphs has been discolored to light brown over the face due to biological and chemical weathering. As the measuring chromaticity based on the non-weathered layer, the whiteness and yellowness increased in the weathered layer, and the color difference (ΔE) was 5.54 to 36.89 (mean 17.26). In the weathered layer of the petroglyph surface, the CaO content was reduced by about 90% compared to the non-weathered layer, and Sr also showed the same trend. In particular, the mean porosity of the non-weathered layer was 0.4%, but it was estimated as 25.0% in the weathered layer. This is interpreted as the fact that calcite reacts with water, and forms a weathered layer from the surface as it is eluted. Based on the weathering depth modeling of the petroglyphs using the penetration characteristics of X-rays, the weathering depth of rock faces was found to be 1 to 2mm. However, the area classified as 2mm or more estimated to be a maximum of 3 to 4mm, considering the weathering depth around the petroglyphs surface.

• Journal of the Korean BIBLIA Society for library and Information Science
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• v.33 no.1
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• pp.371-401
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• 2022

If the blockchain means storing information in a distributed environment that cannot be forged or altered, it is mentioned that this is similar to what librarians collect, preserve, and share authoritative information. In this way, this study examined blockchain technology as a way to collect and provide reliable information, increase work efficiency inside and outside the library, and strengthen cooperative networks. This study attempted to propose various ways to utilize blockchain technology in book relations based on literature surveys and case studies in other fields. To this end, this study first analyzed the field and cases of blockchain application to confirm the possibility and value of blockchain application in the library field, and proposed 12 ways to utilize it based on this. The utilization model was proposed by dividing it into operation and service sectors. In the operation sector, it is a digital identity-based user record storage and authentication function, transparent management and traceable monitoring function, voting-based personnel and recruitment system, blockchain governance-based network efficiency function, and blockchain-based next-generation device management and information integration function. The service sector includes improved book purchase and sharing efficiency due to simplification of intermediaries, digital content copyright protection and management functions, customized service provision based on customer behavior analysis, blockchain-based online learning platforms, sharing platforms, and P2P-based reliable information sharing platforms.

• Journal of Life Science
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• v.33 no.6
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• pp.506-511
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• 2023

The purposes of this study were to isolate and characterize lactic acid bacteria with antibacterial activity against Methicillin-resistant Staphylococcus aureus (MRSA) from fermented food and to confirm the antibacterial activities of fermented rice products using the isolated lactic acid bacterium. Three bacteria, namely, Weissella sp. ISF-1, ISF-2, and ISF-3, were selected from fermented squid based on the 16S rRNA gene sequence. All three strains grew well in an MRS medium containing 5% (w/v) NaCl and showed antibacterial activity against Bacillus cereus, Staphylococcus aureus, and MRSA. Their growth was excellent at 0% ~ 5% (w/v) NaCl and relatively good up to 7% (w/v) NaCl. The initial pH of 8 was optimal for their growth, and good growth was also observed at pH 6, 7, and 9. The lyophilisates of the fermented rice using Weissella sp. ISF-1 showed antibacterial activities against B. cereus, S. aureus, and MRSA. We inferred that isolated lactic acid bacteria could be useful in the development of probiotics and biopreservatives for foods and in the treatment of MRSA and may increase the value of rice products.

• Journal of the Korea Society of Computer and Information
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• v.28 no.4
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• pp.133-142
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• 2023

National parks are one of the important types of protected area management systems established by IUCN and a management model for implementing effective conservation and sustainable use of natural and cultural heritage in countries around the world, and they assume important roles in conservation, scientific research, education, recreation and driving community development. In the context of big data, this study takes China's Liaohe National Park, a typical representative of global coastal wetlands, as a case study, and using Python technology to collect tourists' travelogues and reviews from major OTA websites in China as a source. The text spans from 2015 to 2022 and contains 2998 reviews with 166,588 words in total. The results show that wildlife resources, natural landscape, wetland ecology and the fishing and hunting culture of northern China are fully reflected in the perceptions of visitors to Liaohe National Park; visitors have strong positive feelings toward Liaohe National Park, but there is still much room for improvement in supporting services and facilities, public education and visitor experience and participation.

• Economic and Environmental Geology
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• v.56 no.6
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• pp.629-646
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• 2023

Host rock of Cheonjeon-ri petroglyph is shale belonging to the Daegu Formation of Cretaceous Gyeongsang Supergroup. The rocks were hornfelsified by thermal alteration, and shows high density and hardness. The petroglyph forms weathered zone with certain depth, and has difference in mineral and chemical composition from the unweathered zone. As the physical deterioration evaluations, most of cracks on the surface appear parallel to the bedding, and are concentrated in the upper part with relatively low density. Breakout parts are occurred in the upper and lower parts of the petroglyph, accounting for 6.0% of the total area and occurs to have been created by the wedging action of cracks crossing. The first exfoliation parts occupying the surface were 23.8% of the total area, the second exfoliations covered with 9.3%, and the exfoliation parts with three or more times were calculated as 3.4%. It is interpreted that this is not due to natural weathering, and the thermal shock caused by the cremation custom here in the past. As the ultrasonic properties, the petroglyph indicates highly strength in the horizontal direction parallel to bedding, and the area with little physical damage recorded mean of 4,684 m/s, but the area with severe cracks and exfoliations showed difference from 2,597 to 3,382 m/s on average. Physical deterioration to the Cheonjeon-ri petroglyph occurred to influence by repeated weathering, which caused the rock surface to become more severe than the inside and the binding force of minerals to weaken. Therefore, it can be understood that when greater stress occurs in the weathered zone than in the unweathered zone, the relatively weathered surface loses its support and exfoliation occurs.

• Economic and Environmental Geology
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• v.57 no.3
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• pp.343-352
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• 2024

Composition analysis and lead isotope ratio analysis were conducted to determine the coloring machanism on lead glaze used in Gyeongbokgung Palace and the provenance of the lead used as a flux. 31 blue tiles were classified into green, blue, and yellow. The chemical analysis of lead glazes on the blue tiles revealed that Pb, Si, and Cu were the main components, and trace amounts of Fe, Ca, Mg, and Al were detected. The Cu content was high in blue lead glaze, while Cu was not detected in yellow or brown lead glaze which instead had high Fe content. Therefore, it was found that lead was used as a flux and copper oxide as a coloring agent in the production of lead glaze. In addition, the lead isotope ratios of the lead glaze used in the blue tiles of Gyeongbokgung palace were plotted in zone 3 on the distribution map of lead isotope ratios on the Korean Peninsula, which includes Chungcheong-do and Jeolla-do. It is presumed that the flux for the lead glaze was sourced from galena found in these regions. The lead isotope ratios of the green glaze from the Three Kingdoms and Unified Silla period were mostly located outside the Korean Peninsula, showing that the provenance of lead had changed. In particular, the lead isotope ratios of the green glaze from the Three Kingdoms and Unified Silla period suggest exchange with neighboring countries. Also the lead isotope ratios of the green glazes from the same temple are different, so it is believed that they were made at different times or in different workshops.

• Journal of Life Science
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• v.34 no.6
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• pp.418-425
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• 2024

Solid tumors are heterogeneous populations of multiple cell types. While the majority of the cells that comprise cancer are unable to divide, cancer stem cells have self-renewal and differentiation properties. Normal stem cell pathways that control self-renewal are overactivated in cancer stem cells, making cancer stem cells important for cancer cell expansion and progression. Dick first proposed the definition of cancer stem cells in acute myeloid leukemia, according to which cancer stem cells can be classified based on the expression of cell surface markers. Cancer stem cells maintain their potential in the tumor microenvironment. Multiple cell types in the tumor microenvironment maintain quiescent cancer stem cells and serve as regulators of cancer growth. Since current cancer treatments target proliferative cells, quiescent state cancer stem cells that are resistant to treatment increase the risk of recurrence or metastasis. Various signals of the tumor microenvironment induce changes to become a tumor-supportive environment by remodeling the vasculature and extracellular matrix. To effectively treat cancer, cancer stem cells and the tumor microenvironment must be targeted. Therefore, it is important to understand how the tumor microenvironment induces reprogramming of the immune response to promote cancer growth, immune resistance, and metastasis. In this review, we discuss the cellular and molecular mechanisms that can enhance immunosuppression in the tumor microenvironment.

• Journal of Korean Home Economics Education Association
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• v.18 no.1 s.39
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• pp.77-93
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• 2006

As our current society is increasingly demanding a Home Economics Education curriculum that projects the recent changes around us, in this study we hope to present which fundamental materials would be needed in Home Economics Education to satisfy the needs of learners in schools and to Provide actual practice and information crucial to live in the future society. A reform of the present Home Economics regime is needed, and as a result of critical analysis on the subject we found that it did not portray the plurality of family relations and cultures owing to the sudden changes in society, nor did it present an active curriculum that could be applied to the changes in social environments. This was partly because of the matter of establishing a proper academic identity of Home Economics Education, the matter of specializing curriculums and general methods of applying them, the academic conservatism in the field of Home Economics, and ineffectiveness of teacher reeducation as well as a lack of leadership on the part of administrative departments. The objective and content structure of Home Economics Education should be reformed to adjust to the current society by taking an approach focused on family and the consumer. In the family part, curriculums should include the formations of various family structures and home cultures to portray a more open concept of family, which should promote gender equality in matters of child upbringing and housework. From a humanitive perspective, Home Education should he dealing with the mediation and decision-making of individuals caught between social advancement and household functions. their communication skills in choosing and deciding, and furthermore their participation in their living communities which may present more material basis of critical scientific philosophies to be discussed in class. Additional themes such as sustainable consumption for earth environment and resource preservation and ways of application to rebuild our diminishing society must also be included in the education curriculum. We should look to find a more integrated approach to Home Economics Education rather than the present field based and specialized regime.

• Korean Journal of Agricultural Science
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• v.33 no.1
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• pp.17-24
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• 2006

An experiment was conducted to investigate the effects of forced molting and egg storage time on the various egg qualities. A total of 240 ISA Brown layers (60 wk of age) were employed as the unmolted treatment (Control). Two hundred and forty ISA Brown layers, molted at the age of 55 wk, were used as a forced molting treatment (T1), and the same number and strain of layers, molted at the age of 70 wk, were also used as the another forced molting treatment (T2). A total of 120 eggs were sampled from each treatment, and divided into six sets, 20 eggs per set. These six sets were stored for 1, 3, 6, 9, 12, and 15 days at $18^{\circ}C$ temperature, respectively. Eggs from T1 were collected from laying hens at the age of 68 wk, which started molting at 60 wk of age and achieved 50% egg production at 63 wk of age. Eggs from T2 were collected from hens at 82 wk of age, which started molting at 70 wk of age and achieved 50% egg production at 78 wk of age. The eggshell strength of T1 was significantly (p<0.05) higher than the Control and T2, and the storing periods did not affect the eggshell strength at all. Neither the forced molting nor the storing periods did not exert any consistent effect on the egg weight, eggshell thickness, eggshell color and egg yolk color. The albumin heights of T1 and T2 were significantly (p<0.05) lower than the Control, and it was remarkably reduced gradually as the storage periods increased in all three treatments. The Haugh unit showed very similar trends as the albumin height, indicating that both albumin height and Haugh unit were very much related to each other. In conclusion, the forced molting improves the eggshell strength, but decreases the albumin height and Haugh unit. The storage of eggs also decreases the albumin height and Haugh unit regardless of molting.

• Korean Journal of Agricultural Science
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• v.20 no.2
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• pp.153-166
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• 1993

The experiments were conducted to improve raw milk quality during storage, the chemical composition and microbiological aspect of raw milk, milk thermized at $65^{\circ}C$ for 30 second, and $75^{\circ}C$ for 2 second stored at $5^{\circ}C$ for 4 days were investigated. The result obtained were summarized as follows : 1. During storage of raw and thermized milk, in the composition of milk fat, milk protein, lactose and total solid did not change significantly. 2. The range of pH and acidity for the raw milk were 6.73~5.94 and 0.16~0.27% respectively and those of the thermized milk were 6.79~6.62 and 0.16~0.17% respectively. The phosphatase test were negative in heated milk. 3. The composition of total nitrogen, NCN and whey protein were decreased, wherease those of NPN and casein were increased in heat treated milk. 4. The compositions of total nitrogen and casein were decreased as the storage period advanced, wherese those of NCN and NPN were increased. However, the composition of whey protein did not significantly change. 5. The number of coliform bacteria was not found in thermized milk. but were gradually increased in raw milk during storage period. 6. Raw milk had total bacteria count as $5.6{\times}10^6/ml$, psychrotrophic bacteria $1.8{\times}10^6/ml$ and thermoduric bacteria $1.6{\times}10^5/ml$, as the heat treatment increased microorganism counts decreased to milk thermized at $75^{\circ}C$, for 2 sec. $3.0{\times}10^3/ml$, $1.5{\times}10/ml$ and $2.7{\times}10^3/ml$ respectively. 7. The count of thermoduric bacteria, psychrotrophic bacteria and total bacteria were increased during storage period, and more rapidly increased in raw milk than in heat treated milk.