• Journal of Korean Society of Forest Science
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• v.112 no.1
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• pp.57-70
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• 2023

In recent years, the frequency of warnings about particulate matter (PM) has gradually increased in Korea, along with an increase in its intensity. Because of their vast surface area, reactivity to external particles, and characteristics of their leaves, urban trees can act as biofilters, reducing PM pollution. However, the air pollutant PM can cause various types of damage not only to human health but also to vegetation. Studies performed to date on the responses of trees to PM are still insufficient. Here, we analyzed the correlation between PM adsorption and physiological and biochemical responses of four major street tree species, namely, Abies holophylla, Acer buergerianum, Pinus densiflora, and Quercus variabilis, under conditions of approximately 300 ㎍ m^-3 of fly ash emissions using a phytotron. The results showed that the physiological and biochemical responses and PM adsorption differed depending on the tree species. In correlation analysis, it was confirmed that there were positive correlations between physiological factors, and PM adsorption on adaxial leaf surfaces negatively impacted the physiological characteristics. This study provides fundamental information for selecting tree species to reduce PM pollution and develop sustainable urban forests.

• Tunnel and Underground Space
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• v.32 no.6
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• pp.491-501
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• 2022

Bentonite has been proposed as a buffer and backfill material for high-level radioactive waste repository. Under such repository environment conditions, bentonite is subjected to combined thermal, hydrological, mechanical, and chemical processes. This study evaluates the feasibility of applying X-ray CT technology on the characterization of bentonite under hydration conditions using a newly developed testing cell. The cylindrical cell is made of platic material, with a removable cap to place the sample, enabling to apply vertical pressure on the sample and to measure swelling pressure. The hydration test was carried out with a sample made of Gyeonju bentonite, with a dry density of 1.4 g/cm³, and a water content of 20%. The sample had a diameter of 27.5 mm and a height of 34 mm. During the test, water was injected at a constant pressure of 0.207 MPa, and lasted for 7 days. After one day of hydration, bentonite swelled and filled out the space inside the cell. Moreover, CT histograms showed how the hydration process induced an initial increase and later progressive decrease on the density of the sample. Detailed profiles of the mean CT value, CT standard deviation, and CT gradient provided more details on the hydration process of the sample and showed how the bottom and top regions exhibited a decrease on density while the middle region showed an increase, especially during the first two days of hydration. Later, the differences in CT values with respect to the initial state decreased, and were small at the end of testing. The formation and later reduction of cracks was also characterized through CT scanning.

• Korean Journal of Environment and Ecology
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• v.36 no.6
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• pp.582-591
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• 2022

This study was conducted to eliminate Myocastor coypusMolina, 1782 (Nutria) from Jeju Special Self-Governing Province, South Korea. Habitat identification and eradication were carried out from September to November 2013, and a survey was carried out until June 2022 to check whether the eradication was successful. The habitat was identified with unmanned cameras, interviews, and literature surveys, and the capture was performed using the trapping method with food to attract nutria to the habitat area. The study area for the follow-up survey, which was set relatively wide considering nutria's home range, included wetlands and rivers within 4.0 km² of the habitat area (eradication area). As a result, nutria's habitat was confirmed only at Songdang Ranch, Songdang-ri, of Jeju Island, with traces of habitat (footprints, excrement, and burrows) confirmed in waterways and ponds within the pasture. Eight individuals were captured, including four females, three males, and one individual in too advanced a state of decay to identify the sex. The follow-up survey thoroughly investigated the habitat and its surroundings, focusing on three areas with permanent water, Seongeup Reservoir, Cheonmi Creek, and Molsuni Pond, but no signs of habitat were identified. Therefore, it is determined that nutria inhabiting Jeju Island has been completely eradicated. It is believed that the successful eradication of nutria in the Jeju Special Autonomous Region was possible due to a synergy between 1) the eradication of nutria at the beginning of the settlement phase through rapid capture after confirming the nutria habitat and 2) the delayed expansion period because of rare presence of wetlands, where water is constantly stagnant, on Jeju Island. These results imply that quickly identifying the ecological characteristics of the species and preventing disturbances before they or at the beginning of the ecological disturbance through control and eradication at the initial stage of settlement before the expansion stage is an effective measure to cope with the influx of alien species.

• Korean Journal of Environmental Biology
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• v.40 no.2
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• pp.224-238
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• 2022

North Korea has actively participated in the international community related to environmental agreements. It has proposed various environmental policies internally since the Kim Jong-un regime. In particular, it emphasizes activities related to climate change response, the Sustainable Development Goals, and the conservation of ecosystems including forests and wetlands. In this study, a new security cooperation plan was proposed with an understanding of the climate crisis and environmental regime as a starting point. To this end, trends and recent activities for climate-environment cooperation in the international community and on the Korean Peninsula were analyzed. In addition, North Korea's conditions for cooperation on the Korean Peninsula, technology demand, and the projected future environment of the Korean Peninsula were dealt with. Ultimately, through advice of experts, we were able to discover cooperation agendas by sector and propose short-term and long-term environmental cooperation strategies for the Korean Peninsula based on them. In this study, conditions and directions for cooperation in fields of climate technology, biological resources, air/weather, water environment, biodiversity, renewable energy, bioenergy, and so on were considered comprehensively. Among 21 cooperation agendas discovered in this study, energy showed the largest number of areas. Renewable energy, forest resources, and environmental and meteorological information stood out as agendas that could be cooperated in the short term. As representative initiatives, joint promotion of 'renewable energy' that could contribute to North Korea's energy demand and carbon neutrality and 'forest cooperation' that could be recognized as a source of disaster reduction and greenhouse gas sinks were suggested.

• Journal of Service Research and Studies
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• v.13 no.2
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• pp.62-81
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• 2023

The purpose of this study is to propose policies to improve and revitalize rural bus services in Jeollabuk-do in the future by identifying the factors that affect service satisfaction and policy satisfaction and the relationship between them, targeting rural bus users in 4 cities and counties in Jeollabuk-do. In the four cities and counties in the study area, the number of rural bus users is continuously decreasing, and various transportation policies, such as unification of bus fares and demand-response transportation, are being piloted to promote bus use. In this study, three major service quality factors that affect rural bus service satisfaction and policy satisfaction were derived after a literature review. Modifying the research model presented in previous studies, we have presented a research model to verify the relationship between the three factors affecting service satisfaction and policy satisfaction, and the relationship between service satisfaction and policy satisfaction. For the verification of the research model, a total of 520 survey data collected from passengers near bus stops and bus terminals in four cities and counties, Gochang, Gimje, Buan, and Jeongeup, were used. As a result of the verification, it was found that the three factors of economic feasibility, convenience, and safety had a statistically positive (+) effect on service satisfaction, but only convenience and safety had a positive (+) effect on policy satisfaction. Contrary to the research hypothesis, it was found that there was no statistically significant relationship between service satisfaction and policy satisfaction. Although the result is different from the research hypothesis, it was a meaningful result that can make policy suggestions on the improvement of the unified fare system policy, service satisfaction, and policy satisfaction to Jeollabuk-do rural bus transportation policy makers and working-level officers. In conclusion, based on the results of research analysis, the unified fare system, and transportation policy, measures to improve service satisfaction and policy satisfaction were presented.

• Journal of Bio-Environment Control
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• v.32 no.2
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• pp.89-96
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• 2023

This study was conducted to apply with an air duct for the cooling and a utilizing cultivating method that uses the fruiting node and the defoliation to the high-temperature vertical and hydroponic cultivation of the oriental melon. The lower fruiting node (LF) was to remove all third vines generated from 5 nodes of a secondary vine. The higher fruiting node (HF) was fruiting on the third vine generated from a first node of the third vine. The direction of the stem string; upward (UW), downward (DW). Four treatment conditions were applied with the LF-UW, LF-DW, HF-UW (control), and HF-DW. The leaf age of melon leaves was measured for photosynthesis at 3 days intervals, and the fruit characteristic was conducted on 79 fruits in each treatment. The photosynthesis rate steadily increased after leaf development, reaching 20.8 μmol CO₂·m^-2·s^-1 on the 10 days, gradually increasing to 21.3 μmol CO₂·m^-2·s^-1 on the 19 days, and reaching 23.4 μmol CO₂·m^-2·s^-1 on the 32 days. After that, it lowered to 16.8 μmol CO₂·m^-2·s^-1 on the 38 days and dropped significantly to 7.6 μmol CO₂·m^-2·s^-1 on the 47 days. As a result of the fruit characteristics by fruiting nodes, the treatments of the fruit length was 12.6-13.4 cm, respectively, which was significant, and the fruit width was 7.9- 8.6 cm, respectively, was not significant. The soluble content ranged from 12.9 to 15.7°Brix, and the significance of all treatments, and higher than of LF-DW and HF-UW. The photosynthesis rate of melon leaves was good until 32 days after leaf development, but after that, the rate decreased. As for fruit quality, it was conformed that melons can be cultivated at the LF because the fruit enlargement and soluble content dose not decrease even when set at the LF. Results indicated that those can be used for LF and defoliation in the development of vertical and hydroponic cultivation method in high-temperature season.

• Conservation Science in Museum
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• v.29
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• pp.133-152
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• 2023

This study references preceding studies to examine the history of paint application techniques using various paints in the past, with the aim to contribute to the long-term preservation of large military cultural heritage assets situated outdoors. To this end, the study compared the findings of preceding research with the findings of an analysis conducted on a H-13 helicopter housed at the War Memorial of Korea. Upon collecting and analyzing samples from three grounded WWII aircraft from above-ground by preceding studies, it was confirmed from each sample that the various chemical properties of chrome ensured the effectiveness of the protective coating. The compound was first tested as a corrosion-inhibiting pigment in the early 1940s and proved its excellent moisture-resistant properties over the course of 80 years, despite the deterioration of the paint layer and long-term exposure to the natural environment. For this reason, it has been widely used as a corrosion inhibitor for aluminum alloys in the aviation industry. In other word, the most widely-used material for preventing corrosion was an organic primer containing chromate. In this study, based on the paint analysis of a H-13 helicopter operated in the Korean War, it was shown that the second layer, consisting of the primer, contains chromium oxide (Cr₂O₃). In addition, it was estimated that red lead tetraoxide (Pb₃O₄) was used for the vehicle. Analysis results and data from previous studies can help to confirm the continued effectiveness of corrosion prevention function provided by chromate. Meanwhile, the result of infrared spectroscopy analysis confirmed the use of alkyd resin. In the future, comparisons with a more diverse range of artifacts will allow the identification of changes in the manufacturing technology of paints used to protect alloys from corrosion.

• Journal of Dental Rehabilitation and Applied Science
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• v.38 no.1
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• pp.18-25
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• 2022

Purpose: This study aimed to evaluate the color stability and antibacterial properties of the surface of polyethyl methacrylate (PEMA) resin with zirconia nanoparticles added. Materials and Methods: The control group was pure PEMA resin, and the experiment group was PEMA resin 15 mm in diameter and 2.5 mm in thickness disk-shaped specimens with 2, 4 and 8 w/v% of zirconia nanoparticles added, which were respectively divided into Group Z2, Group Z4, and Group Z8. After analyzing the surface roughness and color stability of the specimens, their antibacterial properties were evaluated using Porphyromonas gingivalis (P. gingivalis). The Statistical analysis was performed using when normality was met in the Shapiro-Wilk test, one-way ANOVA was used to test parameters, and Tukey's test was used as a post hoc test. When normality was not met, the Kruskal-Wallis test, a non-parametric test was used (P < 0.05). Results: The surface roughness measurement found that there was no significant difference between the experimental and control groups. The color stability evaluation showed that the Z2, Z4, and Z8 groups were within the color range of natural teeth. The adhesion of P. gingivalis was evaluated to be significantly reduced in Group Z2 compared to the control group (P < 0.05). In the Z2 group, Z4 group, and Z8 group, dead cells bacteria than the control group were observed. Conclusion: In conclusion, PEMA resin with zirconia nanoparticles added was within the range of natural teeth in color and reduced the adhesion of P. gingivalis.

• Journal of Korean Philosophical Society
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• v.115
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• pp.249-279
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• 2010

The Law of the Heart, which appears in the chapter "B. The Actualization of Rational Self-consciousness Through its own Activity" in Hegel's Phenomenology of Spirit represents that the self-certainty of the reason may be the another face of the Madness. The Reason's indubitable certainty is the testimony of the truth for Descartes, and it also plays a role as the moral maxim of the conscience for Kant. But this subjective certainty unavoidably leads to the Madness of self-conceit, which unifies the consciousness and the reality ignoring the difference between them. The typical attitude appearing in the reformer like Don Quixote and also romantic idealists reveals the fact that modern reason and the psychosis can be both faces of one and the same coin. The Mirror Stage, the Imaginary, and the Formula of the Desire in Lacan's Theory shows that the Image of completeness is the result of Mis-understanding. Even if the Mirror stage is necessary for the Formation of the subject, at the same time it should also lead to the next stage, i.e., the Symbolic Order. It is considered as the realm of the Otherness, which refers to the realm of language or that of law. If the Ego can't go through the symbolic castration acted on by the Name of the Father, he will be remained in the prison of the Imaginary. The Madness also shows the similar process. For Hegel the Discipline of the Labor or the Death as absolute Otherness that inevitably delays the Desire plays the same role as the name of Father. It may be the experience of Separation or that of Sublation of the individual towards the universal, which is equivalent to the experience of Symbolic castration in Lacan. Furthermore there may be the difference between Hegel and Lacan as the following; while in Hegel the experience of Separation is founded on the spontaneity of the Spirit, for Lacan it is to be compelled and structured by the absolute Other.

• Journal of Popular Narrative
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• v.25 no.4
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• pp.191-221
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• 2019

This study aims to analyze the post-humanistic imagination that has emerged as a major academic thesis in Korean literature, especially novels. In particular, this paper focuses on Cho Ha-hyung's two novels Chimera's Morning(2004) and A Prefabricated Bodhi Tree(2008), published in the early 2000s, for intensive analysis. Post-humanism can be seen as an extension of post-modernism that tried to overcome the limitations of modernity and seek to establish a new world view. In particular, this thought pays attention to the comprehensive understanding of how the rapid development of science and technology, which has developed since the 20th century, has changed the view of humanity and human-centered civilization itself. At the concrete level, it is developing in the direction of constructing a new subject idea by reflecting and dismantling Western-, reason-, and male-centered power mechanisms that are the core of modern civilization. Cho attempts to discover and re-illuminate the surrounding figures, non-humans, and objects that were not noticed in the classic works written in the past. This ideological flow reflects the fact that the concept of human beings, which had been dominated by the humanities in recent years, has been completely changed, and the natural science and technology perspective is applied to the discourse field in various ways. From the point of view of post-humanism, objects that have not been classified as humans and objects that were considered inferior to humans should be included in human or comparable levels. These questions generate interdisciplinary research tasks by involving the large categories of philosophy, such as ontology, epistemology and empirical fields, as well as calling for the participation of the entire literature, science and social sciences. Against the backdrop of a disaster-hit world, Chimera's Morning and A Prefabricated Bodhi Tree depict human beings as variants transformed by bio-technology, and creatures made out of the artificial intelligence built by computer simulations. Post-humanistic ideas in Cho's novels provide a reflective opportunity to comprehensively reconsider the world's shape and human identity reproduced in the text, and to re-explore boundary lines and hierarchy order that distinguish between human and non-human.