• Conservation Science in Museum
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• v.24
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• pp.1-16
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• 2020

This paper presents the process of re-conservation and the results of research on the production method of the Iron Sword with Ring Pommel with Three-Pointed Leaf Decoration, one of the excavation findings from Tomb No. 55 in the Dalseong Ancient Tomb Complex in Daegu. This iron sword is a double weapon with two large swords housed within a single sheath. Four smaller swords are attached to the surface of the sheath, two on the upper portion and the other two below. It is the only such two-in-one weapon excavated intact thus far from an ancient Korean tomb. The records show that it underwent conservation treatment twice in the past. In this study, it was subjected to conservation treatment again to replace the stiffener in some cracking areas, and its material, composition, and production method were analyzed by CT, XRF analysis, and stereoscopic microscopy. The sword is mainly made of copper, but the golden component contains both gold and mercury, which suggests that the copper was plated in gold using mercury amalgamation. The examination of the production methods indicates that it was intended more to demonstrate the authority of its owner rather than to serve any practical use. The two upper small swords on the sheath were made in the same manner as the main swords, and the two small lower swords were cut from a single metal sheet. The sheath was made by cutting two metal sheets. Supports were used to attach the two small swords to the upper portion of the sheath, while the lower portion of the sheath was slit to allow the other two small swords to be inserted into it. The ring pommels of the main swords have a three-pointed leaf decoration. As for the other designs, the handle of the main sword features a series of semicircles, the decorative bands on the sheath have waves in dots, and the fish tail of the sheath shows diagonal lines of dots.

• Journal of Life Science
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• v.31 no.6
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• pp.543-549
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• 2021

Approximately 10% of all angiosperms belong to the Asteraceae family. Plant species belonging to this family have traditionally been used as medicinal plants in the Korean Peninsula. We investigated the antioxidant activity of seed extracts from 14 species belonging to the Asteraceae family. Seeds with ≥ 90% percentage of filled seed and ≥ 50% final germination were used. The total phenolic content was the highest in Dendranthema zawadskii var. tenuisectum (13.5 mg of gallic acid equivalents (GAEs)/g seeds), followed by Dendranthema zawadskii var. latilobum (11.8 mg of GAEs/g seeds), and Callistephus chinensis (11.0 mg of GAEs/g seeds). The total flavonoid content was highest in C. chinensis (9.8 mg of quercetin equivalents (QEs)/g seeds), followed by D. zawadskii var. tenuisectum (7.2 mg of QEs/g seeds) and Taraxacum officinale (6.3 mg of QEs/g seeds). Our results showed that 2,2-diphenyl-1-picrylhydrazyl radical (DPPH) scavenging activity was highest in D. zawadskii var. tenuisectum (57.4 ㎍/ml), followed by T. officinale (59.1 ㎍/ml) and D. zawadskii var. latilobum (65.0 ㎍/ml), with a half maximal inhibitory concentration (IC₅₀) of DPPH scavenging activity. Furthermore, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging activity was highest in C. chinensis (26.2 ㎍/ml), followed by D. zawadskii var. tenuisectum (38.4 ㎍/ml), T. officinale (40.2 ㎍/ml), with a half maximal inhibitory concentration (IC₅₀) of ABTS scavenging activity. Based on a cluster analysis according to the antioxidant activity, the 14 species were classified into five groups, with group 4 having the highest antioxidant activity and group 0 having the lowest antioxidant activity. D. zawadskii var. latilobum, D. zawadskii var. tenuisectum, T. officinale, and C. chinensis belonging to groups 3 and 4, exhibited high phenolic content and antioxidant activity and can be considered potent plant-derived natural antioxidants.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.66 no.4
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• pp.307-317
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• 2021

In recent years, global warming has led to frequent climate change-related problems, and elevated temperatures, among adverse climatic factors, represent a critical problem negatively affecting crop growth and yield. In this context, the present study examined the physiological traits of wheat plants grown under high temperatures. Specifically, the effects of elevated temperatures on seed development after heading were evaluated, and the vegetation indices of different organs were assessed using hyperspectral analysis. Among physiological traits, leaf greenness and OJIP parameters were higher in the high-temperature treatment than in the control treatment. Similarly, the leaf photosynthetic rate during seed development was higher in the high-temperature treatment than in the control treatment. Moreover, temperature by organ was higher in the high-temperature treatment than in the control treatment; consequently, the leaf transpiration rate and stomatal conductance were higher in the control treatment than in the high-temperature treatment. On all measuring dates, the weight of spikes and seeds corresponding to the sink organs was greater in the high-temperature treatment than in the control treatment. Additionally, the seed growth rate was higher in the high-temperature treatment than in the control treatment 14 days after heading, which may be attributed to the higher redistribution of photosynthates at the early stage of seed development in the former. In hyperspectral analysis, the vegetation indices related to leaf chlorophyll content and nitrogen state were higher in the high-temperature treatment than in the control treatment after heading. Our results suggest that elevated temperatures after the booting stage positively affect wheat growth and yield.

• Korean Chemical Engineering Research
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• v.60 no.1
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• pp.116-124
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• 2022

In this study, waste air containing ethanol and hydrogen sulfide, was treated by an integrated hybrid system composed of two alternatively-operating UV/photocatalytic reactor-process and biofilter processes of a biofilter system having two units with an improved design (R reactor) and a conventional biofilter (L reactor). Both a pressure drop (△p) per unit process of the integrated hybrid system and a microbe-population-distribution of each biofilter process were observed. The △p of the UV/photocatalytic reactor process turned out very negligible. The △p of the L reactor was observed to increase continuously to 4.0~5.0 mmH₂O (i.e., 5.0~6.25 mmH₂O/m). In case of R reactor, its △p showed the one below ca. 16~20% of the △p of the L reactor. Adopting such microbes-carrying biofilter media with high porosity as waste-tire crumb media, and the improved biofilter design, contributed to △p of this study, reduced by ca. 37~50% and 40~53%, respectively, from the reported △p of conventional biofilter packed with biofilter media of the mixture (50:50) of wood chip and wood bark. In addition, the △p of R reactor in this study, reduced by ca. 80% from the reported △p of conventional biofilter packed with biofilter media of the mixture (75:25) of scoria with high porosity and compost, was mainly attributed to adopting the improved biofilter design. On the other hand, in case of L reactor, the CFU counts in its lowest column was analyzed double as much as those in any other columns. However, in case of R reactor, its CFU counts were bigger by 50% than the one of L reactor and its microbes were evenly distributed at its higher and lower columns of R_dn reactor and R_up reactor. This phenomena was attributed to an even moisture distribution of 50~55% of R reactor at its higher and lower columns. Therefore, R reactor showed superb characteristics in terms of both △p and microbe-population-distribution, compared to L reactor.

• The Journal of Korean Academy of Prosthodontics
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• v.60 no.2
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• pp.135-142
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• 2022

Purpose. This study aims to evaluate the combined effect of reduced thickness in different regions on the fracture resistance of monolithic zirconia crowns. Materials and methods. Seven nickel-chromium dies were generated from a 3D model of mandibular first molar using the digital scanner with the following geometries: 1.5 mm occlusal reduction, 1.0 mm deep chamfer. Based on the abutment model, Zirconia blocks (Luxen Zirconia) were selected to fabricate Sixty-three zirconia crowns with occlusal thicknesses of 0.3 mm, 0.5 mm, and 1.5 mm, and different axial thicknesses of 0.3 mm, 0.5 mm, and 1.0 mm. All crowns were cemented by resin cement. Next, the crowns were subjected to load-to-fracture test until fracture using an electronic universal testing machine. In addition, fracture patterns were observed with a scanning electron microscope (SEM). Two-way ANOVA and the Tuckey HSD test for post hoc analysis were used for statistical analysis (P < .05). Results. The mean values of fracture resistancerecorded was higher than the average biting force in the posterior region. The two-way ANOVA showed that the occlusal and axial thickness affected the fracture resistance significantly (P < .05). However, the effect of axial thickness on fracture resistance did not show a statistical difference when thicker than 0.5 mm. The observed failure modes were partial or complete fracture depending on the severity of crack propagation. Conclusion. Within the limitations of the present study, the CAD-CAM monolithic zirconia crown with extremely reduced thickness showed adequate fracture resistance to withstand occlusal load in molar regions. In addition, both occlusal and axial thickness affected the fracture resistance of the zirconia crown and showed different results as combined.

• Journal of the Daesoon Academy of Sciences
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• v.35
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• pp.39-71
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• 2020

Ever since gaining liberation in 1945, Korean society has constantly recalled memories of Japan's invasion and Korea's anti-Japanese movements for an independent state (AMIS). In the process, a small number of new religious groups were also identified as main subjects within AMIS. However, the logic necessary to connect these religious groups with AMIS was still weak. In order to solve this situation academically, the purpose of this article is to illuminate the activities of Mugeukdo (無極道) and Jo Jeongsan (趙鼎山) through the lens of AMIS and to reflect on the issues that will arise when linking the religion with AMIS. Regarding this purpose, this article analyzed the internal and external data collected by Daesoon Jinrihoe (大巡眞理會) about Jo Jeongsan and Mugeukdo's activities linked to AMIS. Later, this paper presents several tasks for future research on this subject matter. Specifically, according to Chapter II, the AMIS of Jo Jeongsan and Mugeukdo were generally centered on resistance at the family level, Jo Jeongsan's order to participate in the March 1st Movement, and Mugeukdo's industrial activities. In Chapter III, I reviewed the contents of Chapter II using Daesoon Jinrihoe's external materials. According to the results of the review, future research is required to discover and cross-check materials related to the AMIS of Jo Jeongsan and Mugeukdo believers. Likewise, further research is needed to highlight the theory of the enthronement of emperor (天子登極說) and the Great Opening of the later world (後天開闢) in terms of AMIS. These efforts can make contributions that increase the credibility of Daesoon Jinrihoe's internal data on the AMIS of Jo Jeongsan and Mugeukdo and expand the periphery of AMIS as it relates to certain religious groups. Subsequently, in Chapter IV, I present three items for reflecting upon the connection between certain religious groups and AMIS. The first is that criteria for establishing the category of AMIS is necessary to determine whether religious activities can be included. Second, reductionist approaches make it difficult to explain the reasons why some of the people who participated in AMIS did so while forming 'new religious movements,' and why these groups have maintained their religious identity even after liberation was achieved in 1945. Third, it is necessary to distinguish between the primary and the secondary dimensions to elaborate on the connection between these religions and AMIS. This means that researchers should be expected to look at whether the activities in question are based on a religious worldview and whether the goal of the activities is the realization of AMIS or the implementation of some aspect of that religious worldview. In the future, considering the mechanisms that make AMIS memorable in Korea, religious groups and religious studies should take greater interest in discovering and accumulating data that facilitates research on these topics. At the same time, effort should be made to find the basis for AMIS within religious worldviews. It can also be made possible through specific interest in further elaboration on the various AMIS-related activities of Jo Jeongsan and Mugeukdo.

• Industry Promotion Research
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• v.7 no.2
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• pp.43-49
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• 2022

This study aims to study Esping-Anderson's theory of welfare state system, develop a model of welfare state suitable for Korea's situation, and apply it to reality. In this research method, basic research and analysis of ideology is used, focusing on Esping-Anderson's welfare state system theory, and applying it appropriately to the Korean situation. Studies on the model of the welfare state have been studied after the classification of complementary and institutional models asserted by Willensky and Lebo in 1965. In addition, Esping-Andersen asserts three things as a model of the welfare state according to ideology. First, the role of the market is central to the liberal welfare system that best fits the image of classical capitalism, and individualistic solidarity through the market. The role of the state or family, which can be a hindrance, is actually marginalized. In addition, in order to maximize individualistic solidarity through the market, de-commodification in the national domain tends to be minimized. Second, the conservative welfare system has a strong familistic element, so the source of social solidarity is the family, and the state plays a role of supporting and supplementing the characteristics of this family. In the conservative system, de-commodification appears to be high among household heads, or the welfare system takes on a corporatist and nationalistic form, it can be said that these characteristics are reflected. Third, in the social democratic welfare system, the source of social solidarity is the state. Therefore, the role of the state is large, the state has a high possibility of decommodification, and it has the characteristics of substitutes for the family and the market through universalist intervention. This study applies Esping-Anderson's three welfare state models to study a model suitable for the Korean situation. In conclusion, Esping-Anderson's three welfare state models can be classified into a market-oriented model based on a liberal welfare system, a status-oriented model based on a conservative corporatist welfare system, and a solidarity-oriented model based on a social-democratic welfare system, presented a compromise between liberalism and conservatism as a Korean model.

• The Journal of the Convergence on Culture Technology
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• v.7 no.4
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• pp.693-704
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• 2021

This study empirically verified the effect of strategic orientation on information technology(IT) competency and corporate performance for organizational members engaged in small and medium-sized enterprises (SMEs). In the research model proposed in this study, strategic orientation affects corporate performance, and IT competency is used as a mediating variable in this process. For this study, a survey was conducted on organizational members working in small and medium-sized manufacturers located in Ulsan Metropolitan City. A total of 320 questionnaires were distributed, and 277 copies were used in this study. The collected data were statistically analyzed using SPSS 24.0. The research results are as follows: First, customer orientation, market orientation, and technology orientation of strategic orientation were found to have a positive (+) effect on both information technology knowledge and information technology operation of IT competency. And it was found that both customer orientation and technology orientation of strategic orientation only affects the information technology infrastructure of IT competency. Second, it was found that customer orientation and technology orientation of strategic orientation had a positive (+) effect on corporate performance, but market orientation had no effect on corporate performance. Third, it was found that information technology knowledge, information technology operation, and information technology infrastructure of IT competency had a positive (+) effect on corporate performance. Fourth, as a result of examining the mediating effect of information technology competency between strategic orientation and corporate performance, information technology knowledge, information technology operation, and information technology infrastructure of IT capability were found to have a partial mediating effect between customer orientation and technology orientation of strategic orientation and corporate performance. These research results suggest that in today's fourth industrial revolution era, customer-oriented and technology-oriented management strategies should be established to improve the competitive advantage and performance of small and medium-sized enterprises(SMEs) in the supply chain with large enterprises, and at the same time information technology capabilities such as information technology knowledge, information technology operation, and information technology infrastructure should be strengthened.

• Journal of The Korean Association For Science Education
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• v.42 no.3
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• pp.325-340
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• 2022

This study attempts to analyze the causes of low affective achievement of elementary, middle, and high school students in Korea in science. To this end, a total of 27 students, three to four students per grade, were interviewed by grade from the fourth grade of elementary school to the first grade of high school, and a total of nine teachers were interviewed by school level. In the interview, related questions were asked in five sub-areas of the 'Indicators of Positive Experiences about Science': 'Science Academic Emotion', 'Science-Related Self-Concept', 'Science Learning Motivation', 'Science-Related Career Aspiration', and 'Science-Related Attitude'. Interview contents were recorded, transcribed, and categorized. As a result of examining the causes of low science academic emotion, it was found that students experienced negative emotions when experiments are not carried out properly, scientific theories and terms are difficult, and recording the inquiry results is burdensome. In addition, students responded that science-related self-concept changed negatively due to poor science grades, difficult scientific terms, and a large amount of learning. The reasons for the decline in science learning motivation were the lack of awareness of relationship between science class content and daily life, difficulty in science class content, poor science grades, and lack of relevance to one's interest or career path. The main reason for the decline in science-related career aspirations was that they feel their career path was not related to science, and due to poor science performance. Science-related attitudes changed negatively due to difficulties in science classes or negative feelings about science classes, and high school students recognized the ambivalence of science on society. Based on the results of the interview, support for experiments and basic science education, improvement of elementary school supplementary textbook 'experiment & observation', development of teaching and learning materials, and provision of science-related career information were proposed.

• Korean Journal of Heritage: History & Science
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• v.55 no.1
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• pp.51-61
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• 2022

Earthenware horn cups with horse head decorations were excavated from Tomb No. 7 of Bokcheon-dong, Dongraegu, Busan Metropolitan City. Made of earth in the shape of a horn, these cups are considered to have been used to drink alcohol or beverage. Large numbers of earthenware horn cups of various shapes were excavated from tombs located in the old territories of Silla and Gaya. A pair of earthenware horn cups were excavated from Tomb No. 7, and the two cups are almost identical in overall shapes and manufacturing techniques despite different sizes. Conservation treatment was carried out for the bigger one of the two horn cups this time. There are two cracks toward the horse head decorations around the mouth with missing parts observed. The chest of the horse touches the ground with one side decorating the horse head and the other side facing the conical mouth of the horn cup. It is in the U shape, striking a balance based on two legs attached behind. The surface of the horn cup was made with a potter's wheel, and the connection to the horse head has traces of cutting and trimming. The horse head is expressed realistically with its features including the ears, eyes, nose, and mouth well apprehended and its color is grey This study intended to investigate manufacturing techniques of the artifact by examining its internal structure through the condition survey in a non-destructive way. CT imaging was used to figure out its manufacturing techniques and to diagnose its condition, and accordingly the scientific conservation treatment was conducted to stabilize the artifact. The precise diagnosis on conservation condition found that there are two chips in the spout with their cracks extended. One of the chips is connected with separation added to the crack. The material which has been used for connection in the past was collected for the infrared spectroscopic analysis, which was identified to be nitrocellulose resin for the connection. Therefore, this conservation treatment focused on removing the old material and preventing the spread of cracks. Before conservation treatment, the condition survey and scientific examination for the artifact were carried out to secure data about the earthenware horn cup with horse head decorations(Treasure). Based on them, effective plans for its conservation treatment was sought for and then existing adhesive was safely removed, and restoration material was selected to take into account its reversibility. In addition, the conservation treatment according to optimal methodologies was conducted through the consultation meeting with experts.