• Korean Journal of Environment and Ecology
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• v.36 no.3
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• pp.257-276
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• 2022

Studies on rare and endemic plant conservation should be performed nationally to conserve plant diversity. Studies targeting a specific taxon have been reported based on the necessity of conserving plant diversity. From this point of view, there is an increasing necessity to compare and evaluate the studies for conservation. Moreover, it is necessary to analyze and review the direction for study subjects and items required for effective conservation of rare and endemic plants in Korea, based on the analysis results of collected data. We analyzed trends of studies on rare and endemic plants worldwide. In particular, we collected and analyzed the study trend in Korea. Study fields of the rare and endemic plants were divided into six classifications, of which the conservation ecology classification was sub-divided into the species traits, population study, and biological interaction. We have collected conservation ecology studies showing significant differences in regions and countries. They have been actively conducted in Europe and North America by region and in Japan and the United States by country. On the contrary, studies on basic ecology accounted for the most, followed by conservation genetics and restoration ecology in Korea. It was revealed that the portion of conservation ecology conducted in Korea was lower than that of the world. Moreover, studies mainly focused on a specific taxon of rare and endemic plants, such as endangered plants designated by the Korean Ministry of Environment. Particularly in Korea, conservation genetics and restoration ecology studies accounted for high percentages. Considering the worldwide study trends, particularly those in Europe and North America that lead the study of conservation ecology, we suggest approaches to increase the percentages of conservation ecology, including securing the information on species traits, population structure and population dynamics, and interaction between animals and plants are necessary for effective conservation of rare and endemic plants in Korea.

• Conservation Science in Museum
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• v.26
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• pp.161-182
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• 2021

A jungwangu, a type of medium-sized mortar, is a firearm with a barrel and a bowl-shaped projectileloading component. A bigyeokjincheonroe (bombshell) or a danseok (stone ball) could be used as a projectile. According to the Hwaposik eonhae (Korean Translation of the Method of Production and Use of Artillery, 1635) by Yi Seo, mortars were classified into four types according to its size: large, medium, small, or extra-small. A total of three mortars from the Joseon period have survived, including one large mortar (Treasure No. 857) and two medium versions (Treasure Nos. 858 and 859). In this study, the production method for medium mortars was investigated based on scientific analysis of the two extant medium mortars, respectively housed in the Jinju National Museum (Treasure No. 858) and the Korea Naval Academy Museum (Treasure No. 859). Since only two medium mortars remain in Korea, detailed specifications were compared between them based on precise 3D scanning information of the items, and the measurements were compared with the figures in relevant records from the period. According to the investigation, the two mortars showed only a minute difference in overall size but their weight differed by 5,507 grams. In particular, the location of the wick hole and the length of the handle were distinct. The extant medium mortars are highly similar to the specifications listed in the Hwaposik eonhae. The composition of the medium mortars was analyzed and compared with other bronze gunpowder weapons. The surface composition analysis showed that the medium mortars were made of a ternary alloy of Cu-Sn-Pb with average respective proportions of (wt%) 85.24, 10.16, and 2.98. The material composition of the medium mortars was very similar to the average composition of the small gun from the Joseon period analyzed in previous research. It also showed a similarity with that of bronze gun-metal from medieval Europe. The casting technique was investigated based on a casting defect on the surface and the CT image. Judging by the mold line on the side, it appears that they were made in a piece-mold wherein the mold was halved and using a vertical design with molten metal poured through the end of the chamber and the muzzle was at the bottom. Chaplets, an auxiliary device that fixed the mold and the core to the barrel wall, were identified, which may have been applied to maintain the uniformity of the barrel wall. While the two medium mortars (Treasure Nos. 858 and 859) are highly similar to each other in appearance, considering the difference in the arrangement of the chaplets between the two items it is likely that a different mold design was used for each item.

• Journal of Plant Biotechnology
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• v.49 no.2
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• pp.118-123
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• 2022

To obtain information on the molecular mechanism underlying the low temperature tolerance of sweet potato [Ipomoea batatas (L.) Lam], the proteome expressed in the sweet potato cultivar Xushu 15-1 with high cold storage tolerance and in the cultivar Xushu 15-4 with low cold storage tolerance was analyzed using 2-D and MALDI-TOF/TOF analyses. Compared with the control (without cold treatment), four protein spots were newly expressed in Xushu 15-1. The expression level of one protein spot was higher in Xushu 15-4 than in Xushu 15-1. Spot 2, which was newly expressed in Xushu 15-1, was identified as sporamin. Assessment of the change in protein expression levels over 8 weeks in the storage roots of the two cultivars treated at 4℃ revealed no significant difference in the expression levels in Xushu 15-1 over time. However, in Xushu 15-4, the expression level of one protein spot increased, while those of four spots decreased. Of the proteins with reduced expression levels, spots 7 and 8 were identified as actin and spots 9 and 10 were identified as fructokinase-like proteins. The present results are expected to enhance the understanding of the complex mechanism underlying the low temperature tolerance of sweet potatoes during storage and can be used to identify candidate genes for the development of new varieties of sweet potatoes with improved low temperature tolerance during cold storage in the future.

• Korean Journal of Remote Sensing
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• v.38 no.6_3
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• pp.1817-1826
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• 2022

After the hydrogen fluoride leak in Gumi in 2012, the government has been systemizing the disaster management system, such as responding to and managing chemical accidents. In particular, the Ministry of the Interior and Safety (MOIS) is in charge of evacuation of residents following chemical accidents based on the Framework Act on Management of Disaster and Safety. In this study, an application plan was presented to support and utilize the decision-making support for evacuation of residents after a chemical accident using the chemical accident investigation equipment of the National Disaster Management Research Institute (NDMI). In the equipment operation system for scientific information collection due to chemical accidents, the roles and purpose of use of long/short distance measurement equipment were presented according to regular and emergency situations. Using the data acquired through long/short distance measurement equipment, it can be used as basic data for resident evacuation decision-making by monitoring whether chemicals are detected in an emergency and managing data on detected substances by company in a regular situation. As a result of measuring chemical substances in order to verify on-site usability by equipment only for the regular operation system, it was confirmed that real-time detection of chemical substances is possible with long distance measuring equipment. In addition, it was confirmed that it was necessary to check the measurable distance and range of the equipment in the future. In the case of short distance measurement equipment, hydrocarbon-based substances were mainly detected, and it was confirmed that it was measured at a higher level in Ulsan-Mipo National Industrial Complex than in Onsan National Industrial Complex. It is expected that it can be used as basic data to support decision-making in the event of chemical accidents through continuous data construction in the future.

• Journal of Korea Port Economic Association
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• v.37 no.4
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• pp.127-144
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• 2021

The purpose of this study is to derive service factors based on the "Rail Statistical Yearbook" data of railroad service providers from 1990 to 2019, and to analyze the effect of the service factors on the operating profit ratio(OPR), a representative management performance variable of railroad transport service providers. In particular, it has academic significance in terms of empirical research to evaluate whether the management innovation of the KoRail has changed in line with the purpose of establishing the corporation by dividing the research period into the first period (1990-2003) and the latter (2004-2019). The contents of this study investigated previous studies on the quality of railway passenger transportation service and analyzed the contents of government presentation data related to the management performance evaluation of the KoRail. As an empirical analysis model, a research model was constructed using OPR as a dependent variable and service factor variables of infrastructure, economy, safety, connectivity, and business diversity as explanatory variables based on the operation and management activity information during the analysis period 30 years. On the results of research analysis, OPR is that the infrastructure factor is improved by structural reform or efficiency improvement. And economic factors are the fact that operating profit ratio improves by reducing costs. The safety factor did not reveal the significant explanatory power of the regression coefficient, but the sign of influence was the same as the prediction. Connectivity factor reveals a influence on differences between first period and latter, but OPR impact direction is changed from negative in before to positive in late. This is an evironment in which connectivity is actually realized in later period. On diversity factor, there is no effect of investment share in subsidiaries and government subsidies on OPR.

• Journal of Technology Innovation
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• v.30 no.3
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• pp.1-34
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• 2022

This study examines the effect of CEO age on the value relevance of R&D which is the relationship between R&D expenditures and firm value. The value relevance of R&D expenditures is higher in companies with current older CEOs, while the relationship in companies with younger CEOs is lower than that of other companies. These results suggest that older CEOs tend to be conservative and make prudent R&D investment decisions. Because they make systematic investment decisions with rich experience, they are expected to have higher investment performance in the market. On the other hand, young CEOs choose risky investments in order to have their abilities highly evaluated in the labor market. The market places a high degree of risk on the R&D decision-making of young CEOs. Next, we analyze whether the age of the replaced CEOs affects the relationship between R&D expenditures and firm value. The result shows that the change of management increases the effect of R&D expenditure on firm value. However, in the case of being replaced by a younger CEO, this positive relationship becomes lower than that of other companies, showing results consistent with the case of the current younger CEO. The samples are analyzed by dividing them into conglomerates and non-conglomerates. In conglomerates, the age of the replaced CEOs does not affect the value relevance of R&D expenditures. Only non-conglomerates showed a negative (-) effect on the replaced younger CEOs. These results suggest that conglomerates maintain the stability of R&D management and performance so that the performance of R&D expenditures is not significantly affected by the age of the replaced CEOs. The reason is that mutual checks and support are coordinated within the group through decentralization of work and systematization of decision-making. This study shows evidence that the relationship between R&D expenditure and firm value according to the age of the replaced CEO is a phenomenon that only occurs in non-conglomerates. This phenomenon suggests that conglomerates are stably managing their R&D performance regardless of the change of CEOs or the characteristics of the CEOs.

• Economic and Environmental Geology
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• v.54 no.2
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• pp.271-283
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• 2021

The Imjingang Belt in the middle-western Korean Peninsula has tectonically been correlated with the Permo-Triassic Qinling-Dabie-Sulu collisional belt between the North and South China cratons in terms of collisional tectonics. Within the belt, crustal-scale extensional ductile shear zones that were interpreted to be formed during collapsing stage with thrusts and folds were reported as evidence of collisional events by previous studies. In this study, we tried to understand the nature of deformation along the southern boundary of the belt in the Munsan area based on the interpretations of recently conducted structural analyses. To figure out the realistic geometry of the study area, the down-plunge projection was carried out based on the geometric relationships between structural elements from the detailed field investigation. We also conducted kinematic interpretations based on the observed shear sense indicators from the outcrops and the oriented thin-sections made from the mylonite samples. The prominent structures of the Munsan area are the regional-scale ENE-WSW striking thrust and the N-S trending map-scale folds, both in its hanging wall and footwall areas. Shear sense indicators suggest both eastward and westward vergence, showing opposite directions on each limb of the map-scale folds in the Munsan area. In addition, observed deformed microstructures from the biotite gneiss and the metasyenite of the Munsan area suggest that their deformation conditions are corresponding to the typical mid-crustal plastic deformation of the quartzofeldspathic metamorphic rocks. These microstructural results combined with the macro-scale structural interpretations suggest that the shear zones preserved in the Munsan area is mostly related to the development of the N-S trending map-scale folds that might be formed by flexural folding rather than the previously reported E-W trending crustal-scale extensional ductile shear zone by Permo-Triassic collision. These detailed examinations of the structures preserved in the Imjingang Belt can further contribute to solving the tectonic enigma of the Korean collisional orogen.

• Economic and Environmental Geology
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• v.55 no.1
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• pp.77-95
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• 2022

The Gonamsan gabbroic complex in the Pocheon area, northwestern region of South Korea consists of a variety types of gabbroic rocks and associated Fe-Ti oxide deposits caused by magmatic differentiation. Post-magmatic intrusions (i.e., gabbroic pegmatite and pyroxene-apatite-zircon rocks) partly intruded into the gabbroic rocks. The gabbroic pegmatite occurs in monzodiorite and oxide gabbro of the complex, intimately and spatially associated with high-grade lenticular Fe-Ti oxide mineralization. The pegmatite can be subdivided into plagioclase-amphibole and pyroxene-olivine pegmatite, in which the contact surface is sharp. The plagioclase-amphibole pegmatite comprises plagioclase and amphibole, with lesser amount of pyroxene, ilmenite, sphene, apatite, and biotite. The pegmatite shows plagioclase-amphibole intergranular texture, in which the open space formed by large plagioclase laths (An_2-26Ab_72-98Or_0-2) are infilled by amphibole. The pyroxene-olivine pegmatite is dark gray to black in color and also contains magnetite, ilmenite, spinel, apatite, and calcite as a minor component. The pyroxene (En_35-36Fs_8-9Wo₅₅) and olivine (Fo_84-85Fa_15-16) partly show a poikilitic texture defined by smaller euhedral olivine enclosed by coarser clinopyroxene. Fe-Ti oxide minerals consist mainly of magnetite and ilmenite that are found interstitially to earlier formed silicates. Subsequently, they are encompassed by reaction rim (almost of amphibole and biotite) along the boundary with surrounding silicate minerals. Under the microscope, magnetite contains a lot of oxyexsolved ilmenite (trellis type) and spinel, and thereby is weakly enriched in magnetite-compatible elements such as Ti, Al, Mg, and V. The structure and textures at the contact zone as well as mineralogical disequilibrium between gabbroic pegmatite and the host gabbroic rocks suggest that the pegmatite may form as a result of accumulation from Fe-rich melt (or liquid) that occurred somewhere rather than in situ form from the host gabbroic rock during the magmatic differentiation. Consequently, the preliminary study suggests that further study on the post-magmatic activities can not only help us improve our understanding on magmatic fractionation but also provide critical information on Fe-Ti oxide mineralization in gabbroic rocks resulting from the magmatic differentiation.

• Journal of the Korean earth science society
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• v.43 no.1
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• pp.151-164
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• 2022

According to the records of historical and instrumental earthquakes, the southeastern part of the Korean Peninsula is considered the highest seismic activity area. Owing to recent reports of numerous Quaternary faults along the Yangsan and Ulsan fault zones, paleoseismological studies are being actively conducted in these areas. The study area is located in the central part of the Ulsan fault zone, where the largest number of active faults have been reported. Based on lineament and geomorphic analysis using LiDAR images and aerial photographs, fault-related landforms showing topographic relief were observed and a trench survey was conducted. The trench length 20 m, width 5 m, depth 5 m is located approximately 300 m away to the northeast from the previously reported Malbang fault. From the trench section, we interpreted the geometric and kinematic characteristics of the fault based on the deformed features of the Quaternary sedimentary layers. The attitude of the reverse fault, N26°W/33°NE, is similar to those of the reported faults distributed along the Ulsan fault zone. Although a single apparent displacement of approximately 40 cm has been observed, the true displacement could not be calculated due to the absence of the slickenline on the fault plane. Based on the geochronological results of the cryogenic structure proposed in a previous study, the most recent faulting event has been estimated as being earlier than the late Wurm glaciation. We interpreted the thrust fault system of the study area as an imbrication structure based on the previous studies and the fault geometry obtained in this additional trench. Although several previous investigations including many trench surveys have been conducted, they found limited success in obtaining the information on fault parameters, which could be due to complex characteristics of the reverse fault system. Additional paleoseismic studies will contribute to solving the mentioned problems and the comprehensive fault evolution.

• Journal of Applied Biological Chemistry
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• v.65 no.4
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• pp.253-259
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• 2022

The aim of this study was to investigate the correlation between growth characteristics and ginsenoside contents of 4-year-old wild-simulated ginseng cultivated in different regions. Most of the soil properties except for available phosphate showed significantly higher in Pyeongchang than in other cultivation sites. The growth characteristics except for root length and number of rootlets showed significantly higher in Pyeongchang than in other cultivation sites. In the case of 8 ginsenoside contents, the content of F2-AS was significantly higher in Muju than in other cultivation sites and the content of F1 in Yeongju was significantly high. In Yeongwol, the contents of Rb1 and Re-p were significantly high and the content of Ro in Pyeongchang showed significantly higher than in other cultivation sites. Root length and soil pH did not show a significant correlation with any soil properties and growth characteristics of wild-simulated ginseng, respectively. Most of the growth characteristics showed significantly positive correlations with electrical conductivity, organic matter content, total nitrogen content, exchangeable cations (K⁺, Ca²⁺, Mg²⁺), and cation exchange capacity. Rb1 and Re-p showed significantly negative correlations with most of the growth characteristics of wild-simulated ginseng except for the number of rootlets. Ro showed a significantly positive correlation with stem length, number of leaflets per stem, leaflet length, leaflet width, and root diameter. The results of this study probably will help to provide useful information on the establish a quality standard by investigate correlation analysis between growth characteristics and ginsenoside content of 4-year-old wild-simulated ginseng.