• Korean Journal of Environment and Ecology
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• v.36 no.6
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• pp.676-683
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• 2022

Due to the effects of rapid changes in the living environment since 2000 and the recent unforeseen pandemic, people are refraining from domestic and international traveling and movement, and outdoor activities for health and the public value of forest trails, called Dullegil Trail in Korea, have become more important. This study estimated the environmental value of the tentatively named "East-West Trail," which connects the forest trails crossing Chungcheong and Gyeongsang Provinces using CVM (Contingent Valuation Method). It surveyed visitors to the East-West Trail, and 725 questionnaires were used for analysis. The average characteristics of respondents were those who exercised 2-3 times per week, visited a forest trail not far from their residence with friends or family, and showed a tendency to spend 50 thousand Korean won or more per visit. Visitors to the Dullegil Trail felt that there was a shortage of information boards on the forest trail, and they preferred a shelter in appropriate locations. We used a double-bounded dichotomous choice (BDDC) logit model proposed by Hanemann to measure the conservation value of the East-West Trail. It was estimated that the environmental value that a visitor to the East-West Trail could obtain was 30,087 won per trip. The estimated environmental value of the East-West Trail can be converted to about 94 billion won total visitors annually based on the population belonging to the direct-use zone near the East-West Trail. As there has been no study on the environmental value of forest trails using CVM, the results of this study will be able to suggest the feasibility of the government policies on forest trails.

• Journal of Service Research and Studies
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• v.13 no.1
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• pp.186-200
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• 2023

This study aims to improve the usability of the white cane, which is walking equipment that most local visually impaired people use and carry when going out, and to contribute to the prevention of safety accidents and the walking rights of visually impaired people by providing improvement and resolution measures for the problems identified. Also, this study is a study on the visually impaired, primarily targeting the 1st to 2nd degree visually impaired people, who cannot go out on their own without walking equipment such as a white cane, corresponding to 20% among approximately 250,000 blind and low vision people in the Korean population. In the study process, the concept has been developed from the user's point of view in order that the white cane becomes a real help in the walking step of the visually impaired and the improvement of usability of the white cane, the main walking equipment for the visually impaired, are done by problem identification through the Double Diamond Model of Design Thinking (Empathize → Define → Ideate → Prototype → Test (verify)). As a result of the investigation in the process of Empathy, a total of five issues was synthesized, including an increase in the proportion of the visually impaired people, an insufficient workforce situation to help all the visually impaired, an improvement and advancement of assistive devices essential for the visually impaired, problems of damage, illegal occupation, demolition, maintenance about braille blocks, making braille block paradigms for the visually impaired and for everyone. In Ideate and Prototype steps, situations derived from brainstorming were grouped and the relationship were made through the KJ method, and specific situations and major causes were organized to establish the direction of the concept. The derived solutions and major functions are defined in four categories, and representative situations requiring solutions and major functions are organized into two user scenarios. Ideas were visualized by arranging the virtual Persona and Customer Journey Map according to the situation and producing a prototype through 3D modeling. Finally, in the evaluation, the final concept derived is a device such a smart cane for guidance for the visually impaired as ① a smart cane emphasizing portability + ② compatibility with other electronic devices + ③ a product with safety and convenience.

• Journal of the Korean Geotechnical Society
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• v.25 no.4
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• pp.91-103
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• 2009

Slope failure depends upon the climatic features related to related rainfall, structural geology and geomorphological features as well as the variation of the mechanical behaviors of soil constituting a slope. In this paper, among many variables, effects of soil layer thickness on the slope failure process, and variations of matric suction and volumetric water content were observed. When the soil layer is relatively thick, the descending wetting front decreases matric suction and the observed matric suction reaches to "0" value. When the wetting front reaches to the impermeable boundary, the bottom surface of steel soil box, ascending wetting front was observed. This observation can be postulated to be the effects of various sizes of pores. When macro size pores exist, the capillary effects can be reduced and infilling of pore will be limited. The partially filled pores would be filled with water during the ascending of the wetting front, which bounces from the impermeable boundary. This assumption has been assured from the observation of variation of the volumetric water contents at different depth. When the soil layer is thick (thickness = 20 cm), for granular material, erosion is a cause triggering the slope failure. It has been found that the initiation of erosion occurs when the top soil is fully saturated. Meanwhile, when the soil layer is shallow (thickness = 10 cm), slope slides as en mass. The slope failure for this condition occurs when the wetting front reaches to the interface between the soil layer and steel soil box. As the wetting front approaches to the bottom of soil layer, reduction of shear resistance along the boundary and increase of the unit weight due to the infiltration occur and these produce complex effects on the slope failure processes.

• Journal of Marine Life Science
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• v.8 no.1
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• pp.8-31
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• 2023

To understand the distribution and formation mechanism of benthic foraminiferal assemblages, grain size analysis, ¹⁴C radiocarbon dating, and benthic foraminifera analysis were conducted on thirty-two surface sediments collected from the continental shelf of the northern East China Sea, respectively. Surface sediment was composed of sandy mud~muddy sand facies with an average of 52.04% of sand, 13.72% of silt, and 34.20% of clay. These sedimentary facies are palimpsest sediment. Benthic foraminifera was classified into a total of 48 genera and 104 species, including agglutinated foraminifera, calcareous-hyaline, and calcareous-porcelaneous foraminifera. The production rate of agglutinated foraminifera increased toward the Yangtze River area while that of planktonic foraminifera increased toward Jeju Island. Dominant species are Ammonia ketienziensis, Bolivina robusta, Eggella advena, Eilohedra nipponica, Pseudorotalia gamardii, Pseudoparrella naraensis. ¹⁴C radiocarbon datings of Bolivina robusta and Pseudorotalia gamardii with the highest production rate were 2,360±40 yr B.P. and 2,450±40 yr B.P., respectively. In the result of cluster analysis, three assemblages composed of P. gaimardii, B. robusta, and A. ketienziensis-P. naraensis were classified broadly. P. gaimardii assemblage is thought to be formed from about 2.5 yr B.P. at the sea area of the Yangtze River to 50 m in water depth affected by fresh water. B. robusta assemblage is thought to be formed from about 2.4 yr B.P. at the sea area of Jeju Island to 50~100 m affected by offshore water. And then, A. ketienziensisP. naraensis assemblage was formed in the northwest sea area (Central Yellow Sea Mud). These distributions and composition of benthic foraminiferal assemblages formed from about 2.5 yr B.P. in the northern East China Sea are thought to be due to the change of benthic ecology environment that occurred by the sea level increase during the late Holocene.

• Journal of Bio-Environment Control
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• v.32 no.2
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• pp.122-131
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• 2023

This study was aimed to determine the effects of grow media on the mineral contents of the leaves and growth characteristics of strawberry grown under aquaponics system in a plant factory. For aquaculture, 12 fish (Cyprinus carpio) (total weight, 2.0 kg) were raised in an aquaponics tank (W 0.7 m × L 1.5 m × H 0.45 m, 472.5 L) filled with 367.5 L of water at a density of 5.44 kg·m^-3 and total 34 of strawberry seedlings were transplanted in the pots filed with 200 g of orchid stone, hydroball or polyurethane sponge in the growing bed (W 0.7 m × L 1.5 m × H 0.22 m) laid out with holly acrylic sheet (140×60 mm, Ø80) on the top of the system. The pH and EC of the aquaponic solution was ranged from 7.6 to 4.9 and 0.24-0.91 dS·m^-1, respectively. The concentration of NO_3-N was about 28% lower than that of the hydroponic standard solution, and K, Fe and B were 10, 27 and 3.8 times lower, respectively; however, the mineral contents of strawberry leaves were in the appropriate ranges with lower contents in the leaves grown with sponge media. The organic content (OM), nitrogen (N), phosphorus (P), and potassium (K) of the sludge were 61.5, 5.72, 8.92, and 0.24%, respectively. The leaf area, leaf number, and dry and fresh weights of shoot at 81 DAT were significantly higher in the hydroball, and the average number of fruits per plant was significantly higher in both the orchid stone and hydroball. There was no significant difference in the fresh and dry weights of fruits. Integrated all the results suggest that the orchid stone and hydroball media are more effective to utilize nutrients in solid particles of aquaponic solution, compared to the polyurethane sponge.

• Journal of Food Hygiene and Safety
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• v.38 no.2
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• pp.69-78
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• 2023

This study aimed to investigate the protective effect of enzymatically modified stevia (EMS) on C2C12 cell-based model of dexamethasone (DEX)-induced muscle atrophy to provide baseline data for utilizing EMS in functional health products. C2C12 cells with DEX-induced muscle atrophy were treated with EMS (10, 50, and 100 ㎍/mL) for 24 h. C2C12 cells were treated with EMS and DEX to test their effects on cell viability and myotube formation (myotube diameter and fusion index), and analyze the expression of muscle strengthening or degrading protein markers. Schisandra chinensis Extract, a common functional ingredient, was used as a positive control. EMS did not show any cytotoxic effect at all treatment concentrations. Moreover, it exerted protective effects on C2C12 cell-based model of DEX-induced muscle atrophy at all concentrations. In addition, the positive effect of EMS on myotube formation was confirmed based on the measurement and comparison of the fusion index and myotube diameter when compared with myotubes treated with DEX alone. EMS treatment reduced the expression of muscle cell degradation-related proteins Fbx32 and MuRF1, and increased the expression of muscle strengthening and synthesis related proteins SIRT1 and pAkt/Akt. Thus, EMS is a potential ingredient for developing functional health foods and should be further evaluated in preclinical models.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.68 no.2
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• pp.81-89
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• 2023

Lime-treated fertilizer (LTF) is manufactured using the lime stabilization method with food waste. LTF is effective in neutralizing acidic soil, improving nutrient and organic matter content in soil, and increasing crop productivity. However, excessive use of LTF in agricultural land can have undesirable effects, such as reduced crop growth and nutrient accumulation in soil. This study was evaluated the effect of different application ratios of LTF on the crop yield index (%), nutrient (N, P₂O₅, K₂O) uptake index (%), and soil chemical properties. The following treatments were applied: untreated (UT), NPK (NPK), NPK+calcium hydroxide (CH), and NPK+1-, 2-, 4-, and 8-times of LTF (LTF1, 2, 4, and 8). The yield index for LTF1 was the highest among different LTF treatments. Moreover the yield index for spring and winter cabbage in LTF1 treatment was 10% and 21% higher, respectively, than that in NPK treatment. The yield and nutrient indices were decreased with the increase in LTF application ratio. The soil pH and EC tended to increase with the increase in LTF ratio, and were the highest at 8.2 and 2.1, respectively, after cultivation for LTF8 (P<0.05). With the increase in soil pH, the soil inorganic nitrogen (NH₄-N, NH₃-N) and available phosphate (Av. P₂O₅) levels were decreased (P<0.05). Our results suggest that LTF1 (643 kg 10a^-1) is an appropriate ratio for improving soil chemical properties and increasing crop yield.

• The Korean Journal of Mycology
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• v.50 no.4
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• pp.281-289
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• 2022

Fusarium head blight is an important disease of small grains. It is mainly caused by members of the Fusarium graminearum species complex (FGSC). Barley and wheat growers spray fungicides, especially demethylation-inhibitor fungicides, to suppress the disease. The objective of this study was to examine the changes in the sensitivity of the FGSC population to the triazole fungicide, propiconazole. A total of 124 and 350 isolates of FGSC were obtained from barley and wheat in Jeolla Province during 2010-2016 and 2020-2021, respectively. The species identity and trichothecene chemotypes of the FGSC isolates were determined based on polymerase chain reaction assays targeting translation elongation factor 1-alpha and TRI12 genes, respectively. Sensitivity to propiconazole was determined based on the effective concentration that reduced 50% of the mycelial growth (EC₅₀) using the agar dilution method. Of all isolates, F. asiaticum with the nivalenol chemotype was the most common (83.9% in 2010-2016 and 96.0% in 2020-2021), followed by F. asiaticum with the 3-acetyl deoxynivalenol chemotype (12.1% in 2010-2016 and 2.9% in 2020-2021). The EC₅₀ values of the isolates collected in 2010-2016 and 2020-2021 ranged from 0.0180 to 11.0166 ㎍/mL and 1.3104 to 17.9587 ㎍/mL, respectively. The mean EC₅₀ value of the isolates increased from 3.8648 ㎍/mL in 2010-2016 to 5.9635 ㎍/mL in 2020-2021. The baseline resistance to propiconazole was determined to be 7 ㎍/mL, based on the EC₅₀ value of isolates collected in 2010-2016, and the ratio of resistant isolates increased from 9.7% in 2010-2016 to 28.6% in 2020-2021.

• Korean Journal of Heritage: History & Science
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• v.55 no.4
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• pp.242-275
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• 2022

This study tries to reveal the structure of the "Kisun"(senior envoy ship) taken by senior envoys for the 10^th to 12^th visits to Japan from the perspective of professional shipbuilding engineering focusing on the theory of the ship in the travel logs of royal envoys to Japan (Sahaengrok) written by Joseon Tongsinsa that includes 12 visits to Japan for about 200 years from 1607 to 1811. The results of the study showed that the size of Kisun for the 10^th to 12^th envoy visits was 19 Pa (把) and a half in length and 6 Pa (把) and 2 Cheok (尺) in width. The height of the Sampan was found to be 2 Pa (把) and 1 Cheok (尺) based on records in Gyemisusarok and Jeungjeonggyorinji. The structure of Kisun was different for each visit but, it was found that Kisun was mainly composed of a main deck, bow (bow plate, stem plate), stern (stern plate), Sampan, Meonge (support), Garyong (support), Sinbang, Gungji, deck, two masts and sail, Gurejjak (mast support), Panok, stern Panok, Taru, dodger, anchor reel, stairs, rail, rudder, oar, and anchor. In addition, wood and iron nails were used together for connection. It was also found that the sail was made of herbage and cotton. This study found that Kisun, which was operated for the 10^th and 12^th envoy visits, was big in terms of length and height among the Joseon Tongsinsa fleet to show the authority and dignity of Joseon and that it had passages outside on the sides of the vessel and paddles were located between the sides and Panok structure and rails were installed on four sides on the Panok, improving stability and linear beauty. The walls of Panok were decorated with the royal Dancheong pattern and fancy murals. In addition, it was found that they wished for a safe voyage by drawing a demon face on the bow. Therefore, it was revealed that Kisun, which was taken by envoys as recorded in travel logs, was made by the state and equipped with structures and functions that enabled international voyages.

• Korean Journal of Environmental Biology
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• v.41 no.1
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• pp.18-30
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• 2023

Forest destruction is an inevitable result of the development processes. According to the environmental impact assessment, over 10% of the destroyed trees need to be recycled and transplanted to minimize the impact of forest destruction. However, the rate of successful transplantation is low, leading to a high rate of tree death. This is attributable to a lack of consideration for environmental factors when choosing a temporary site for transplantation and inadequate management. To monitor transplanted trees, a field survey is essential; however, the spatio-temporal aspect is limited. This study evaluated the applicability of remote sensing for the effective monitoring of transplanted trees. Vegetation indices based on satellite remote sensing were derived to detect time-series changes in the status of the transplanted trees at three temporary transplantation sites. The mortality rate and vitality of transplanted trees before and after the transplant have a similar tendency to the changes in the vegetation indicators. The findings of this study showed that vegetation indices increased after transplantation of trees and decreased as the death rate increased and vitality decreased over time. This study presents a method for assessing newly transplanted trees using satellite images. The approach of utilizing satellite photos and the vegetation index is expected to detect changes in trees that have been transplanted across the country and help to manage tree transplantation for the environmental impact assessment.