• Journal of the Korean Society of Environmental Restoration Technology
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• v.26 no.6
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• pp.21-32
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• 2023

The Environmental Impact Assessment (EIA) plays a pivotal role in predicting the potential environmental impacts of proposed developments and planning appropriate mitigation measures to minimize effects on species. However, as concerns over biodiversity loss rise, there's ongoing debate about the efficacy of these mitigation plans. In this study, we utilized data from EIAs and post-environmental impact surveys to understand the trends in biodiversity during construction and operation phases. By examining 30 urban development projects, we categorized species richness indices of mammals, birds, amphibians, and reptiles into pre-construction, during construction, and post-construction operational stages. The biodiversity trends were analyzed based on the rate of change in these indices. The results revealed three distinct biodiversity change patterns: (A) An initial increase in biodiversity indices post-development, followed by a gradual decline over time; (B) a sustained increase in biodiversity as a result of mitigation measures; and (C) a continuous decline in biodiversity post-development. Furthermore, all species exhibited a higher rate of biodiversity decline during the construction phase compared to the operational phase, with mammals showing the most significant rate of change. Notably, the biodiversity change rate during operation was generally lower than during construction. In particular, mammals seemed to be most influenced by mitigation measures, displaying the smallest rate of change. This study provides empirical evidence on the efficacy of mitigation measures and deliberates on ways to enhance their effectiveness in minimizing the adverse impacts of urban development on biodiversity. These findings can serve as foundational data for addressing terrestrial biodiversity reduction.

• Korean Journal of Environmental Biology
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• v.41 no.4
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• pp.439-446
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• 2023

Mangroves are distributed in intertidal zones of coastal environments or estuarine margins, playing a critical role in the global carbon cycle. However, understanding of the carbon cycle role of mangrove associates in the Republic of Korea is still limited. This research measured soil respiration and leaf gas exchange in three habitats of Hibiscus hamabo(Gimnyeong, Seongsan, and Wimi) and analyzed the impacts on sites and months. Soil respiration was measured once a month from June to October 2022 and leaf gas exchange was measured monthly from June to September 2022. Soil respiration in August(5.7±0.8 μmol CO₂ m^-2 s^-1) was significantly higher than that in other months (p<0.001) and soil respiration increased as air temperature increased (p<0.001). In Seongsan, net photosynthesis in July(9.0±0.9μmol m^-2 s^-1) was significantly higher than that in other months (p<0.001). Net photosynthesis increased as stomatal conductance and transpiration rate increased during the entire period(p<0.001). Furthermore, a weak positive linear relationship was observed between soil respiration and net photosynthesis (r²=0.12; p<0.01). The results indicated that soil respiration was influenced not only by air temperature and season but also by net photosynthesis. This study is expected to provide basic information on the carbon dynamics of mangrove associates.

• Journal of the Korea institute for structural maintenance and inspection
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• v.13 no.1 s.53
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• pp.195-204
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• 2009

Application of steel plates is one of widely used methods for shear strengthening of reinforced concrete beams that are insufficient of shear capacity. While the existing method applying solid steel plates provides good shear rigidity, however, it is concerned by brittle bond failure patterns, inefficient material usage, and low constructability. The use of strap type steel plates has also shortcomings of low strenthening effect due to small interface bonding area and ununified behavior between plates and main body. Therefore, this study aims to introduce the shear strengthening method using slit type steel plate, which can solve out the problems aforementioned, and to verify its strengthening effects on shear capacity. A total of 13 specimens strengthened by slit type steel plates were fabricated with primary test parameters of plate width, slit spacing, and plate thickness. The test results from this study were also compared to those from the existing research on RC beams strengthened by strap type steel plates, and the strengthening effects on shear capacity of specimens having bonded slit type steel plates were quantitatively analyzed. The test results showed that the RC beams strengthened by slit type steel plates had greater shear capacities than those with strap type steel plates, which is considered to be the effects of improved composite behavior and larger interface bonding area in the RC beams strengthened by the slit type steel plates.

• Land and Housing Review
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• v.15 no.3
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• pp.165-175
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• 2024

As living standards improve, the demand for quiet and comfortable environments is increases. However, noise sources are rising due to population growth, urbanization, and industrialization. One solution to this problem is low-noise asphalt pavement, which has fewer installation regulations and can reduce noise at the source. Despite its advantages, there are few evaluation cases and no domestic guidelines for low-noise asphalt pavement. This study aims to evaluate the overall performance of low-noise asphalt pavement on roads in Seoul, focusing on average noise levels, skid resistance, and permeability. Noise measurements were conducted using a digital noise analyzer according to the Ministry of Environment's standards. Results indicated that noise reduction was maintained for 1 to 2 years but decreased over time. Skid resistance, assessed with the British Pendulum Tester, showed excellent performance with values above the standard of 57 in the initial stages after paving. Permeability, evaluated using the KS F 2394 method, was initially effective across all sections but declined over time.

• Korean Journal of Construction Engineering and Management
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• v.25 no.5
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• pp.15-24
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• 2024

System support is a facility that is temporarily installed to support vertical loads at construction sites, and is assembled and installed by reused individual members. These characteristics are likely to lead to poor performance of installed system supports, and even though it is institutionalized to check structural safety at the their design phase, accidents continue to occur at the construction site. Accordingly, safety management of system support is implemented through various institutional methods, but the current system does not consider the performance degradation of temporary facilities due to the reuse of individual temporary members. Therefore, the purpose of this study is to verify the performance of assembled system support. In order to do achieve this purpose, the authors divided individual system supports into unused and used groups and performed compression performance test with defined models assembled with those two groups of system supports. The results of this study are expected to be meaningful as a research case that can quantitatively evaluate safety systems and standards for the performance of existing temporary facilities and suggest directions for improving the safety management system of temporary facilities in the future.

• Journal of Venture Innovation
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• v.7 no.2
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• pp.19-40
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• 2024

This study was conducted to empirically analyze the impact of environmental factors on small and medium-sized enterprises' intention to adopt digital transformation. A research model was derived for empirical analysis. Environmental factors were subdivided into independent variables, including industrial competitive pressure, labor shortage, government support, and lack of financial resources, with CEO's perception serving as a moderating variable. A survey targeted executives and employees of small and medium-sized enterprises, and 240 valid responses were selected for analysis. The structural equation method using Amos 24 was employed for the empirical analysis. The findings indicated that industrial competitive pressure and government support had a significant positive influence on the intention to adopt digital transformation, while lack of financial resources had a significant negative effect. The significance of labor shortage was not tested. The order of influence on the intention to adopt was government support, industrial competitive pressure, and lack of financial resources. In terms of the impact of industrial competitive pressure and lack of financial resources on the intention of small and medium enterprises to adopt digital transformation, it was found that in groups with low CEO perception, the lack of financial resources had a negative effect. On the other hand, in the case of the group with high perception, industrial competitive pressure was found to have a significant positive effect. These research results were academically meaningful as they produced significant findings by focusing on environmental factors among the various factors that affect the digital transformation of small and medium-sized enterprises. Practically, it can be said that the importance of the role of top management in small and medium-sized enterprises was emphasized anew

• The Korean Journal of Mycology
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• v.52 no.1
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• pp.1-11
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• 2024

The present study aimed to screen unrecorded wild yeasts from Jeju lsland and Jangsado on the southern coast of Korea, and to investigate their microbiological characteristics. To date, Coniozyma leucospermi JJD37-2, Hanseniaspora thailandica JJD44-1, Kluyveromyces nonfermentans JJD15-1, Kockovaella fuzhouensis JJD47-3, Vishniacozyma heimaeyensis JJD8-4, Candida carpophila JSDH24-1, Wickerhamomyces strasburgensis JSDH34-2, Candida savonica HJD6-4, and Candida karawaiewii YP23-3 have not been previously recorded in Korea. In the present study, we investigated the microbiological characteristics of these previously unrecorded yeasts. Except for W. strasburgensis JSDH34-2 strain, none of the strains formed spores, and only the C. leucospermi JJD37-2 strain formed pseudomycelia. Almost all strains grew well in yeast extract-peptone-dextrose (YPD) medium, potato dextrose (PD) medium and yeast extract-malt extract (YM) media. C. carpophila JSDH24-1 and W. strasburgensis JSDH34-2 also grew well in YPD medium containing 10% NaCl. H. thailandica JJD44-1 is fermented to produce glucose, fructose and mannose.

• Journal of the Korean Electrochemical Society
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• v.27 no.3
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• pp.97-104
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• 2024

The electrodes of commercialized lithium secondary batteries are manufactured through a wet coating process, and the drying process (DC) is a very important factor as to electrode production speed and process cost. In this study, silicon anodes were manufactured under high-temperature (180 ℃) and low-temperature (50 ℃) DC to investigate the quality and the electrochemical performance of Si-electrodes according to DC. High-temperature DC can quickly evaporate the solvent in the Si-electrode slurry, improving the electrode production rate. However, this also causes the electrode composite to peel off from the current collector. As a result, the Si-electrode's adhesion weakened, and the electrode coating's quality deteriorated. In addition, the Si-electrode manufactured under high-temperature was found to have a thicker composite material than the Si-electrode manufactured under low-temperature. Si-electrodes manufactured under high-temperature had higher sheet resistance and lower electrical conductivity than those manufactured under low-temperature. Consequently, the Si-electrode manufactured under low-temperature showed 152.5% superior cycle performance compared to the Si-electrode manufactured under high-temperature. (Discharge capacities of Si-electrodes manufactured under high-temperature and low-temperature DC were 844 and 1287 mAh g^-1, respectively, after 300 cycles). Establishing the DC of Si-electrodes can easily provide new perspectives to improve the quality and stability of Si-electrodes.

• Journal of Advanced Navigation Technology
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• v.28 no.4
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• pp.559-565
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• 2024

Research on autonomous vehicles is being actively conducted. As autonomous vehicles emerge, there will be a transitional period in which traditional and autonomous vehicles coexist, potentially leading to a higher accident rate. Currently, when a traffic accident occurs, the fault ratio is determined according to the criteria set by the General Insurance Association of Korea. However, the time required to investigate the type of accident is substantial. Additionally, there is an increasing trend in fault ratio disputes, with requests for reconsideration even after the fault ratio has been determined. To reduce these temporal and material costs, we propose a deep learning model that automatically determines fault ratios. In this study, we aimed to determine fault ratios based on accident video through a image classification model based on ResNet-18 and video action recognition using TSN. If this model commercialized, could significantly reduce the time required to measure fault ratios. Moreover, it provides an objective metric for fault ratios that can be offered to the parties involved, potentially alleviating fault ratio disputes.

• Journal of the Daesoon Academy of Sciences
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• v.49
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• pp.157-186
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• 2024

This study aims to understand the symbolic meanings of dragons in the contemporary period through the painting featuring poetry based on the Hwaryong (paintings of dragons) and to analyze the literary representations and characteristics of dragons. First, the shape and aura of the dragon in the paintings should be confirmed. In dragon Painting Poetry (Paintings Featuring Poetry), the shape of the dragon is embodied in the aura of 'spirit.' However, people in previous eras customarily believed that dragons were real. In addition, the main spirit of the Hwaryong was in the representation of the dragon's aura, or "Jeonsin (transmission of spirit)," such as the creature's dragonly virtue or Heavenly Perfection. Next, the rhetorical representation of the dragon in the painting is to be examined. In the actual Painting Poetry, dragon images were relatively common in descriptions of pines, bamboo, and plum trees. The pine-bamboo-plum motif is known as Sehan Samwu (the three friends of the cold season), and since the Northern Song Dynasty, it has become a symbol of literary incision. Manifested as a dragon, the pine-bamboo-plum motif has a common denominator of winding branches, tangled stems, and bluish jade coloration, and like the dragon, it is used as a backdrop for weather phenomena such as rain, wind, and lightning. In the schematic that connects the Hwaryong, dragon Painting Poetry, the original meaning of the dragon is transformed into shapes and language. This is the meaning conveyed by the dragon, and this symbolic meaning was shared among the writers of the period who viewed the poems and paintings.