• Journal of Environmental Impact Assessment
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• v.27 no.6
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• pp.562-581
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• 2018

This study was designed to predict the changes in species richness of plants under the climate change in South Korea. The target species were selected based on the Plants Adaptable to Climate Change in the Korean Peninsula. Altogether, 89 species including 23 native plants, 30 northern plants, and 36 southern plants. We used the Species Distribution Model to predict the potential habitat of individual species under the climate change. We applied ten single-model algorithms and the pre-evaluation weighted ensemble method. And then, species richness was derived from the results of individual species. Two representative concentration pathways (RCP 4.5 and RCP 8.5) were used to simulate the species richness of plants in 2050 and 2070. The current species richness was predicted to be high in the national parks located in the Baekdudaegan mountain range in Gangwon Province and islands of the South Sea. The future species richness was predicted to be lower in the national park and the Baekdudaegan mountain range in Gangwon Province and to be higher for southern coastal regions. The average value of the current species richness showed that the national park area was higher than the whole area of South Korea. However, predicted species richness were not the difference between the national park area and the whole area of South Korea. The difference between current and future species richness of plants could be the disappearance of a large number of native and northern plants from South Korea. The additional reason could be the expansion of potential habitat of southern plants under climate change. However, if species dispersal to a suitable habitat was not achieved, the species richness will be reduced drastically. The results were different depending on whether species were dispersed or not. This study will be useful for the conservation planning, establishment of the protected area, restoration of biological species and strategies for adaptation of climate change.

• Korean Journal of Plant Resources
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• v.32 no.1
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• pp.53-62
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• 2019

The purpose of this study was to establish the in vitro propagation system by shoot tip culture of six Hosta species native to Korea (Hosta capitata (Koidz.) Nakai, H. clausa Nakai, H. jonesii M.G.Chung, H. minor (Baker) Nakai, H. venusta F.Maek., and H. yingeri S.B.Jones) for mass proliferation and a new cultivar development. The shoot tips of each Hosta species were cultured on MS medium containing eight combinations of 0.5, 1.0, 2.0, 4.0 mg/L BA with 0.1 mg/L NAA, 0.1, 0.5, 1.0, 2.0 mg/L TDZ with 0.1 mg/L NAA, and without any PGRs (control). They were investigated on callus, somatic embryo, crown bud, differentiation and growth of shoot and root, total fresh weight after 8 weeks of culture. In all six Hosta species, callus and somatic embryo induction rate and multiple shooting rate of the PGRs treatment group were higher than that of the control group. The highest number of differentiated shoots were obtained on medium supplemented with 2.0 ㎎/L TDZ in H. capitata (5.4), 1.0 mg/L TDZ in H. clausa and H. jonesii (3.3 and 5.8, respectively), 0.5 mg/L BA in H. minor (11.1), 1.0 mg/L BA and 0.1 mg/L TDZ in H. venusta (8.1), and 0.5 mg/L TDZ in H. yingeri (9.8). In somatic embryo formation, the PGRs treatment group of H. jonesii and H. yingeri were more effective than the control group, and the effects were relatively less in H. capitata, H. clausa Nakai, H. minor, H. venusta. Crown bud formation of four Hosta species (H.capitata, H. clausa, H. jonesiig, and H. yingeri) were also higher in the PGRs treatment group than in the control group. Crown bud formation of four Hosta species (H.capitata, H. clausa, H. jonesiig, and H. yingeri) were also higher in the PGRs treatment group than in the control group. H. clausa showed no significant effect on callus and shoot differentiation regardless of the type and concentration of cytokinin, but slightly increased in formation of crown bud in TDZ.

• Journal of the Korean earth science society
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• v.40 no.3
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• pp.227-239
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• 2019

Heavy snowfall events frequently occur in the Gangwon province, and the snowfall amount significantly varies in space due to the complex terrain and topographical modulation of precipitation. Understanding the spatial characteristics of heavy snowfall and its prediction is particularly challenging during snowfall events in the easterly winds. The easterly wind produces a significantly different atmospheric condition. Hence, it brings different precipitation characteristics. In this study, we have investigated the microphysical characteristics of snowfall in the windward and leeward sides of the Taebaek mountain range in the easterly condition. The two snowfall events are selected in the easterly, and the snow particles size distributions (SSD) are observed in the four sites (two windward and two leeward sites) by the PARSIVEL distrometers. We compared the characteristic parameters of SSDs that come from leeward sites to that of windward sites. The results show that SSDs of windward sites have a relatively wide distribution with many small snow particles compared to those of leeward sites. This characteristic is clearly shown by the larger characteristic number concentration and characteristic diameter in the windward sites. Snowfall rate and ice water content of windward also are larger than those of leeward sites. The results indicate that a new generation of snowfall particles is dominant in the windward sites which is likely due to the orographic lifting. In addition, the windward sites show heavy aggregation particles by nearby zero ground temperature that is likely driven by the wet and warm condition near the ocean.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.14 no.3
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• pp.59-71
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• 2019

The domestic unemployment rate is now seriously increasing due to the impact of the international trend of incurring high costs using only a small number of manpower in a situation where the business has been being reduced in size. The nation is taking start-up promotion policies as a way to overcome the problem, but with the advent of excessive entrepreneurs and their concentration on specific areas, their survival is in an unclear situation. Thus, this study was intended to provide a useful direction for successful start-ups by identifying the impact of entrepreneurial motivation and entrepreneurship, internal characteristics of entrepreneurs, and of competency characteristics, external characteristics of them, on sustainability through business performance. Thus, the purpose of this study was to provide a useful direction for successful start-ups by identifying the impact of entrepreneurial motivation and entrepreneurship, internal characteristics of entrepreneurs, competency, and external characteristics, on sustainability through business performance. The result of verifying the hypothesis has showed that entrepreneurial motivation, entrepreneurship, and competency characteristics had a positive effect on business performance, and on the other hand, the business performance had a positive effect on sustainability. In addition, in terms of the impact of entrepreneurial motivation, entrepreneurship, and competency characteristics on sustainability, all of them had mediating effects on business performance. It is obvious that studies on the factors affecting business performance and corporate sustainability up to now have been carried out by only collecting the independent variables of this study individually or two of them. so it is judged that if the study, which has verified the practical direction in general through the verification of entrepreneurs's internal and external characteristics from various angles, is performed more comprehensively along with the addition of background characteristics of entrepreneurs, such as characteristics of start-up preparation, etc., in the future, more in-depth results will be able to be obtained.

• Journal of Christian Education in Korea
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• v.64
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• pp.203-235
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• 2020

The purpose of this study is to identify the degree of social presence perceived by students and to explore the factors that have affected it after practicing Christian Education classes as synchronous distance course due to Covid-19. It is also to suggest effective ways in the aspects of the design and operation to improve social presence. In order to measure social presence and derive influencing factors, research related to synchronous distance class and social presence is summarized through literature review. The researchers also surveyed 58 students in three courses of Christian education major at a University in Gyeonggi-do and conducted in-depth interviews with 6 students. The main findings are as follows: First, the sense of social presence was moderate, the emotional bond was the lowest by sub-factor, the open communication, the sense of community was moderate, and the mutual support and concentration were the highest. Second, factors that had a positive impact on the sense of social reality were group activities, selfintroduction activities, active participation in classes, mutual communication such as Q & A or response to peer learners' opinions during lectures by professors, questions, feedback, etc, and having a smaller number of students. Factors that had a negative impact on the perception of social presence were lack of private conversations, poor participation in classes, lack of communication with each other, and difficulty concentrating. The causes of these negative factors were technical problems and limitations arising from zoom, inconvenience and distracting surroundings, lack of time, and psychological awkwardness. Reflecting the results of the study, orientation to effective synchronous distance course, guidance on smooth communication methods, strengthening the role of professors to promote learning, strengthening group activities and learner-centered activities, and proposing a smaller scale of students were ways that are offered to improve the sense of social presence in synchronous distance courses.

• Journal of Bio-Environment Control
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• v.30 no.1
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• pp.1-9
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• 2021

This study was conducted to examine the changes of photosynthesis, growth, chlorophyll contents and functional material contents in light intensity and EC concentration of wild baby leaf vegetable, Indian lettuce (Lactuca indica L. cv. 'Sunhyang') in DFT hydroponics. The cultivation environment was 25±1℃ of temperature and 60±5% of relative humidity in growth system. At 14 days after sowing, combination effect of light intensity (Photosynthetic Photon Flux Density (PPFD 100, 250, 500 µmol·m-2·s-1) and EC level (EC 0.8, 1.4, 2.0 dS·m-1) of nutrient solution was determined at the baby leaf stage. The photosynthesis rate, stomatal conductance, transpiration rate and water use efficiency of Indian lettuce increased as the light intensity increased. The photosynthesis rate and water use efficiency were highest in PPFD 500-EC 1.4 and PPFD 500-EC 2.0 treatment. The chlorophyll content decreased as the light intensity increased, but chlorophyll a/b ratio increased. Leaf water content and specific leaf area decreased as light intensity increased and a negative correlation (p < 0.001) was recognized. Plant height was the longest in PPFD 100-EC 0.8 and leaf number, fresh weight and dry weight were the highest in PPFD 500-EC 2.0. Anthocyanin and total phenolic compounds were the highest in PPFD 500-EC 1.4 and 2.0 treatment, and antioxidant scavenging ability (DPPH) was high in PPFD 250 and 500 treatments. Considering the growth and functional material contents, the proper light intensity and EC level for hydroponic cultivation of Indian lettuce is PPFD 500-EC 2.0, and PPFD 100 and 250, which are low light conditions, EC 0.8 is suitable for growth.

• Journal of Mushroom
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• v.18 no.4
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• pp.331-338
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• 2020

This study was conducted to cultivate new Lepista nuda varieties with shorter cultivation period and better fruiting body compared to that of wild strains, for mass production and commercial application. Eighteen genetic resources of L. nuda were collected and grown in boxes using rice straw-fermented growth medium. Four lines with fruiting bodies were formed and selected as cross-breeding lines. Although 657 combinations were crossed through monospore crossing, only 17 combinations were bred between the 'CBMLN-19' line and the 'CBMLN-30' line. Among them, 8 lines with fast mycelial growth and high density were selected. After inoculating the rice straw-fermented growth medium with 14 genetic resources and 8 cross-breeding lines, their incubation period was investigated. Six of the cross-breeding lines completed their incubation in 20 days, while 7 of the 14 genetic resources took more than 40 days to complete their incubation, reducing the incubation period by more than 20 days in most cross-breeding lines. After the incubations were completed, the clay loam soil was covered with for post-cultivation, and when the mycelial cultivation was complete, the formation of fruiting bodies was induced after scraping the mycelial bodies under these environmental conditions: 14℃, 95% relative humidity or higher, and 1,500 to 2,000 ppm CO2 concentration. The temperature was reduced to 6℃ at night, resulting in a low temperature shock. Thus, 4 lines of fruiting bodies occurred from two genetic resources 'CBMLN-31' and 'CBMLN-44' and two cross-bred lines 'CBMLN-96' and 'CBMLN-103'. After inoculation, the longest period for fruiting bodies to occur was 100 days for the control:, the genetic resource 'CBMLN-31', and the shortest period (45 days) was observed for the cross-breeding line 'CBMLN-103'. The result of the investigation of the fruiting body characteristics shows that the cross-bred line 'CBMLN-103' showed a small form with 1.9 g of individual weight and 123validstipes per box, which was the highest incidence among the four lines. Another cross-bred line, 'CBMLN-96', had an individual weight of 5.5 g, which is larger than that of 'CBMLN-103'; however, the number of valid stipes per box was 30 less than that of 'CBMLN-103'. Quantity analysis showed that the control, 'CBMLN-31', had the highest quantity of 783 g per box, followed by the cross-bred line, 'CBMLN-96' with 165 g per box, and then the 'CBMLN-103' with 232 g. The quantity of the two crossbred lines was lower than that of the control 'CBMLN-31'; however, the amount of fruiting bodies was higher, and the cultivation period was shortened by 32 to 33 days. Therefore, these two lines would be selected as superior lines.

• Economic and Environmental Geology
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• v.54 no.4
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• pp.409-425
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• 2021

Carbon dioxide has been known to be a typical greenhouse gas causing global warming, and a number of efforts have been proposed to reduce its concentration in the atmosphere. Among them, carbon dioxide capture and storage (CCS) has been taken into great account to accomplish the target reduction of carbon dioxide. In order to commercialize the CCS, its safety should be secured. In particular, if the stored carbon dioxide is leaked in the arable land, serious problems could come up in terms of crop growth. This study was conducted to investigate the effect of carbon dioxide leaked from storage sites on soil fertility. The leakage of carbon dioxide was simulated using the facility of its artificial injection into soils in the laboratory. Several soil chemical properties, such as pH, cation exchange capacity, electrical conductivity, the concentrations of exchangeable cations, nitrogen (N) (total-N, nitrate-N, and ammonia-N), phosphorus (P) (total-P and available-P), sulfur (S) (total-S and available-S), available-boron (B), and the contents of soil organic matter, were monitored as indicators of soil fertility during the period of artificial injection of carbon dioxide. Two kinds of soils, such as non-cultivated and cultivated soils, were compared in the artificial injection tests, and the latter included maize- and soybean-cultivated soils. The non-cultivated soil (NCS) was sandy soil of 42.6% porosity, the maize-cultivated soil (MCS) and soybean-cultivated soil (SCS) were loamy sand having 46.8% and 48.0% of porosities, respectively. The artificial injection facility had six columns: one was for the control without carbon dioxide injection, and the other five columns were used for the injections tests. Total injection periods for NCS and MCS/SCS were 60 and 70 days, respectively, and artificial rainfall events were simulated using one pore volume after the 12-day injection for the NCS and the 14-day injection for the MCS/SCS. After each rainfall event, the soil fertility indicators were measured for soil and leachate solution, and they were compared before and after the injection of carbon dioxide. The results indicate that the residual concentrations of exchangeable cations, total-N, total-P, the content of soil organic matter, and electrical conductivity were not likely to be affected by the injection of carbon dioxide. However, the residual concentrations of nitrate-N, ammonia-N, available-P, available-S, and available-B tended to decrease after the carbon dioxide injection, indicating that soil fertility might be reduced. Meanwhile, soil pH did not seem to be influenced due to the buffering capacity of soils, but it is speculated that a long-term leakage of carbon dioxide might bring about soil acidification.

• Korean Journal of Remote Sensing
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• v.38 no.5_1
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• pp.609-625
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• 2022

Validation of satellite data products is critical for subsequent analysis that is based on the data. Particularly, performance of ocean color products in turbid and shallow near-land ocean areas has been questioned for long time for its difficulty that stems from the complex optical environment with varying distribution of water constituents. Furthermore, validation with ship-based or station-based measurements has also exhibited clear limitation in its spatial scale that is not compatible with that of satellite data. This study firstly performed validation of major GOCI-II products such as remote sensing reflectance, chlorophyll-a concentration, suspended particulate matter, and colored dissolved organic matter, using the in-situ measurements collected from ship-based field campaign. Secondly, this study also presents preliminary analysis on the use of drone images for product validation. Multispectral images were acquired from a MicaSense RedEdge camera onboard a UAV to compensate for the significant scale difference between the ship-based measurements and the satellite data. Variation of water radiance in terms of camera altitude was analyzed for future application of drone images for validation. Validation conducted with a limited number of samples showed that GOCI-II remote sensing reflectance at 555 nm is overestimated more than 30%, and chlorophyll-a and colored dissolved organic matter products exhibited little correlation with in-situ measurements. Suspended particulate matter showed moderate correlation with in-situ measurements (R²~0.6), with approximately 20% uncertainty.

• Journal of the Korean Society of Radiology
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• v.16 no.1
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• pp.35-43
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• 2022

In this study, a survey was conducted and analyzed to find out the satisfaction of online classes among students enrolled in the radiology department of a university located in Busan city. As a result, in terms of satisfaction with online classes, male scores were higher, but there was no statistically significant difference. In the interdisciplinary system, the satisfaction score of the students enrolled in Bachelor's degree was high, and there was a statistically significant difference except for the satisfaction of learning participation (p<0.001, p<0.05). For class satisfaction by grade level, Senior had higher scores, and there were statistically significant differences except for learning participation satisfaction (p<0.001, p<0.01, p<0.05). In the satisfaction survey according to the number of lectures, the scores of the students who took 4-7 lectures were found to be high except for the satisfaction of learning participation, and there was a statistically significant difference (p<0.01, p<0.05). In the method of communication with the instructor, students who used e-mail showed high scores, and there was a statistically significant difference in lecture satisfaction (p<0.05). In the correlation analysis between sub-variables for online classes, statistically significant correlations were established in all areas. Most of the students preferred class methods such as recorded classes and classes using external content such as YouTube, and when asked about the merits of online classes, many students answered that the advantages of online classes were repetitive classes and no restrictions on time and place. When asked about the shortcomings of online classes, many students answered that it was a lack of concentration and lack of communication with the instructor. This study was conducted to provide basic data to improve the satisfaction of online classes that will increase in the future. Therefore, based on the results of this study, it is expected that more quality online classes will be produced so that students' satisfaction with online classes can be improved.