• Journal of Sensor Science and Technology
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• v.31 no.3
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• pp.180-186
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• 2022

Photosynthetically active radiation flux density (PPFD) and daily light integral (DLI) values related to plant photosynthesis were obtained using the sunlight time and insolation data points in the agricultural weather sensor data for Jinan-gun, Jeollabuk-do, Korea from 2016 to 2020. The objective was to optimize the photo-environmental conditions for cultivating ginseng. The range of average monthly sunshine duration was 395.5-664.1 min, with the longest duration observed in June. The range of average annual accumulated daily insolation was 11.98-17.65 MJ·m^-2. The range of average daily external DLI calculated from the insolation and solar time data was 22.3-36.1 mol·m^-2·d^-1, and the annual cumulative DLI was 8,156-13,175 mol·m^-2·d^-1. Both the insolation and DLI values were the highest in 2016 and lowest in 2020. Based on the PPFD required for ginseng growth (111-185 µmol·m^-2·s^-1), the monthly average daily DLI and monthly cumulative DLI were 3.51-5.87 and 82-228 mol·m^-2·d^-1, respectively. The range of five-year average value for the external monthly cumulative DLI was 298-1,459 mol·m^-2·d^-1, and the monthly cumulative DLI values when a black double shading film and blue-white shading film were applied were 101-496 and 36-175 mol·m^-2·d^-1, respectively. A comparative analysis of DLI values indicated that shading was required to ginseng growth throughout the year under natural light. When the black double shading film was used, shading was required from March to October. When the blue-white shading film was applied from April to August, (i.e., the period with active ginseng growth) the appropriate DLI for ginseng growth could be continuously maintained. Regional weather differences due to climate change are gradually increasing, and even in one region, monthly and cumulative DLI values are different every year. Therefore, in order to implement a precise agricultural environment for ginseng cultivation, precise analysis and continuous research using agricultural weather sensor big data is required.

• Journal of Korean Philosophical Society
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• v.124
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• pp.295-320
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• 2012

Greek myth is a play of imagination. It represents world with magic eye. The Greek myth of Homer and Hesiod is the story of gods. But it is the world of imagination which was produced to understand the origins and the causes of natural phenomena with the symbolic factors. It is the frame with which we understand the destiny of human beings. As a world of imagination, Myth is not a total fiction but a symbolically revived world with magic eye. Myth is a play which represents the world with imagination. And it is a play which projects new world yet not exists. Myth is the world of free play with reproduction and imagination. Heraclitus elucidated the structure and change of world with the metaphor of play. He tried to define the meaning of being with play. The play is the clue of elucidating the meaning of being. On play the whole world is reflected. He expressed the world has no ultimate end and is changing endlessly. Philosophical speculation understands the world with the metaphor of play. Metaphor is correlated with the philosophical eye which view the world totally. The human beings are happy when they concentrate upon play. The rule of real world doesn't go in the world of play. They have their own rule which goes in the world of play. Ancient mythologists and pre-socratic philosophers dreamed the life free from the restriction of the nature.

• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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• v.8 no.3
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• pp.407-418
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• 2018

Science and technology have led the development of mankind, but have created problems such as natural depletion, climate change, economic inequality and poverty. The purpose of this study is to explore the meaning of early childhood science for sustainable development to solve these problems and to contribute to the harmony of nature and human beings. In order to accomplish this research objectives, 18 experts and 15 teachers were interviewed on the meaning of sustainable development and the directions of early childhood science education for sustainable development. Early childhood science education for sustainable development was categorized as follows. 'Mutual respect between child-teacher-organism', 'developing individual inquiry-based on community consciousness', 'looking at the world with child's eyes', 'deepening and expanding on topics of interest', 'continuous inquiry and commitment', 'conversation and sharing-centered exploration'. By these results, it was concluded that early childhood science education for sustainable development should start from the perspective of children, and was a meaningful process in which children constantly learn about the nature surrounding themselves based on mutual respect.

• The Journal of the Convergence on Culture Technology
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• v.9 no.4
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• pp.291-301
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• 2023

The purpose of this study is to examine the perception of early childhood teachers on ecological art activities oriented to education for sustainable development. The research results are as follows. First, Early childhood teachers recognized the visual art of natural media, the pursuit of community values, and the participation and communication of social members as educational significance of ecological art activities. And difficulties in practicing ecological art were recognized as lack of educational environment, lack of ecological art teaching materials and specific examples, and teachers' lack of understanding of ecological art. Also, they recognized that ecological art activities foster core competencies in art experience area, such as nature-friendly communication skills, eco-friendly sensibility, and creative convergence skills. Second, regarding ecological art activities and sustainable development education, early childhood teachers considered the difficulties in practice as lack of awareness about sustainable development, lack of play meia and materials, lack of educational policies and support, and insufficient teacher training programs. Also, regarding the SDGs that can be practiced in ecological art activities, teachers were found to be highly aware of 'grow affordable and clean energy', 'improve clean water and sanitation', 'provide quality education' in the order. In the contents of education for sustainable development that can be practiced in ecological art activities, teachers are given the order of 'climate change response', 'clean energy', 'water and sanitation', 'quality education', 'health and well-being' and 'marine ecosystem'. was highly recognized. If an ecological art activity program is developed, the rate of responding that it will be used is high, so it is considered that the development of an ESD-oriented ecological art activity program is urgent.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.2B
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• pp.169-177
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• 2010

Recently due to the typhoon and extreme rainfall induced by abnormal weather and climate change, the probability of severe damage to human life and property is rapidly increasing. Thus it is necessary to create adequate and reliable flood risk map in preparation for those natural disasters. The study area is Seo-gu in Daegu which is located near Geumho river, one of the tributaries of Nakdong river. Inundation depth and velocity at each time were calculated by applying FLUMEN model to the target area of interest, Seo-gu in Daegu. And the research of creating flood risk map was conducted according to the Downstream Hazard Classification Guidelines of USBR. The 2-dimensional inundation analysis for channels and protected lowland with FLUMEN model was carried out with the basic assumption that there's no levee failure against 100 year precipatation and inflow comes only through the overflowing to the protected lowland. The occurrence of overflowing was identified at the levee of Bisan-dong located in Geumho watershed. The level of risk was displayed for house/building residents, drivers and pedestrians using information about depth and velocity of each node computed from the inundation analysis. Once inundation depth map and flood risk map for each region is created with this research method, emergency action guidelines for residents can be systemized and it would be very useful in establishing specified emergency evacuation plans in case of levee failure and overflowing resulting from a flood.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.4B
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• pp.393-403
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• 2008

While characteristics of topography, soil, and vegetation coverage were surveyed, also surface runoff and soil erosion for each rainfall event were measured to analyze effect of change of land cover conditions in mountain areas, Yangyang, directly after wildfire. Fifteen rainfall events were taken in total during the survey period. The result of this survey appeared that the amount of surface runoff and soil erosion are a great difference between plots with rapidly recovered vegetation and bare plots after wildfire. The burned plots where vegetation recovered rapidly generated two times or more of surface runoff and soil erosion than control plots, as burned plots with bare soil showed about ten times of surface runoff and sediment than control plots. The result of correlation analysis between main parameters of the surface runoff and soil erosion presented that rainfall factors and vegetation factors had significant effects on runoff and soil erosion. The sensitivity of runoff and soil erosion showed specially high correlation with vegetation indices. If the land surface disturbed by wildfire are recovered by natural vegetation as time passes, runoff and soil erosion may be decreased gradually. Because runoff and soil erosion in the areas with rare vegetation or bare soil are generated continuously, the discriminated mediation strategies would be established as condition of each region.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.2B
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• pp.193-205
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• 2009

Typhoons occurred in the tropical Pacific region, these might be affected the Korea moving toward north. The strong winds and the heavy rains by the typhoons caused a natural disaster in Korea. In the research, the heavy rainfall events based on typhoons were evaluated quantitative through various statistical techniques. First, probability precipitation and typhoon probability precipitation were compared using frequency analysis. Second, EST probability precipitation was calculated by Empirical Simulation Techniques (EST). Third, NL probability precipitation was estimated by coupled Nonparametric monte carlo simulation and Locally weighted polynomial regression. At the analysis results, the typhoons can be effected Gangneung and Mokpo stations more than other stations. Conversely, the typhoons can be effected Seoul and Inchen stations less than other stations. Also, EST and NL probability precipitation were estimated by the long-term simulation using observed data. Consequently, major hydrologic structures and regions where received the big typhoons impact should be review necessary. Also, EST and NL techniques can be used for climate change by the global warming. Because, these techniques used the relationship between the heavy rainfall events and the typhoons characteristics.

• Journal of The Geomorphological Association of Korea
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• v.27 no.1
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• pp.1-19
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• 2020

A river bed which is submerged in water at high flow and becomes part of the river at low flow, serves as a bridge between the river and the land. The channel bar creates a unique ecosystem with vegetation adapted to the particular environment and the water pool forms a wetland that plays a very important role in the environment. To evaluate anthropogenic impacts on the river bed in the Middle Yeongsangang River, the fluvial landforms in the stream channel were analyzed using multi-temporal remotely-sensed images. In the aerial photograph of 2005 taken before the construction of the large weirs, oxbow lakes, mid-channel bars, point bars, and natural wetlands between the artificial levees were identified. Multiple bars divided the flow of stream water to cause the braided pattern in a particular section. After the construction of the Seungchon weir, aerial photographs of 2013 and 2015 revealed that most of the fluvial landforms disappeared due to the dredging of its riverbed and water level control(maintenance at 7.5El.m). Sentinel-2 images were analyzed to identify differences between before and after the opening of weir gate. Change detection was performed with the near infrared and shortwave infrared spectral bands to effectively distinguish water surfaces from land. As a result, water surface area of the main stream of the Yeongsangang River decreased by 40% from 1.144km² to 0.692km². A large mid-channel bar that has been deposited upstream of the weir was exposed during low water levels, which shows the obvious influence of weir on the river bed. Newly formed unvegetated point bars that were deposited on the inside of a meander bend were identified from the remotely sensed images. As the maintenance period of the weir gate opening was extended, various habitats were created by creating pools and riffles around the channel bars. Considering the ecological and hydrological functions of the river bed, it is expected that the increase in bar areas through weir gate opening will reduce the artificial interference effect of the weir.

• Journal of The Geomorphological Association of Korea
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• v.18 no.2
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• pp.81-98
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• 2011

Among the changes of the Curriculum from the liberation to the present, the biggest change in the highschool geography course appeared during the period from the Period of Syllabus to the 1st National Curriculum. More specifically, during the 1st National Curriculum the highschool geography course which previously had three subjects, 'Natural Environment and Human Lives', 'Human Geography', 'Economic Geography' was reduced to one subject, 'Human Geography.' In addition, while some contents related with astronomy, geology, and biology had been contained in the physiography course, they were left out from the human geography course of the 1st National Curriculum. This reduction of the geography course was related to the context that earth science was newly established in the 1st National Curriculum. Originally the draft plan released in June, 1953, which was 10 months before the formal time allotment criteria list had been made public, contained 'Physical Geography' instead of 'Earth Science'. What is sorry is that the name of 'Physical Geography' did not remain and was changed to 'Earth Science'. The underlying causes of the crisis the geography education is now facing are the reduction of Physical Geography and the emergence of 'Earth Science' during the 1st National Curriculum. To overcome the present crisis, the subject of geography should be changed more meaningful one based on the comprehensive perspective and academic product that geography has accumulated.

• The Bulletin of The Korean Astronomical Society
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• v.46 no.2
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• pp.58.1-59
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• 2021

Exploration of asteroids' internal structure is essential for understanding their evolutional history. It also provides a fundamental information about the history of coalescence and collision of the solar system. Among several models of the internal structures, the rubble-pile model, confirmed by the near-Earth asteroid (25143) Itokawa by Hayabusa mission [1], is now widely regarded as the most common to asteroids with size ranging from 200 m to 10 km [2]. On the contrary, monolithic and core-mantle structures are also possible for small asteroids [3]. It is, however, still challenging to look through the interior of a target object using remote-sensing devices. In this presentation, we introduce our ongoing research conducted at Seoul National and propose an idea to infer the internal structure of Apophis using available instruments. Itokawa's research provides an important benchmark for Apophis exploration because both asteroids have similar size and composition [4][5]. We have conducted research on Itokawa's evolution in terms of collision and space weathering. Space weathering is the surface alteration process caused by solar wind implantation and micrometeorite bombardment [6]. Meanwhile, resurfacing via a collision acts as a counter-process of space weathering by exposing fresh materials under the matured layer and lower the overall degree of space weathering. Therefore, the balance of these two processes determine the space weathering degrees of the asteroid. We focus on the impact evidence on the boulder surface and found that space weathering progresses in only 100-10,000 years and modifies the surface optical properties (Jin & Ishiguro, KAS 2020 Fall Meeting). It is important to note that the timescale is significantly shorter than the Itokawa's age, suggesting that the asteroid can be totally processed by space weathering. Accordingly, our result triggers a further discussion about why Itokawa indicates a moderately fresh spectrum (Sq-type denotes less matured than S-type). For example, Itokawa's smooth terrains show a weaker degree of space weathering than other S-type asteroids [7]. We conjecture that the global seismic shaking caused by collisions with >1 mm-sized interplanetary dust particles induces granular convection, which hinders the progression of space weathering [8]. Note that the efficiency of seismic wave propagation is strongly dependent on the internal structure of the asteroid. Finally, we consider possible approaches to investigate Apophis's internal structure. The first idea is studying the space weathering age, as conducted for Itokawa. If Apophis indicates a younger age, the internal structure would have more voids [9]. In addition, the 2029 close encounter with Earth provides a rare natural opportunity to witness the contrast between before and after the event. If the asteroid exhibits a slight change in shape and space weathering degree, one can determine the physical structure of the internal materials (e.g., rubble-pile monolithic, thick or thin regolith layer, the cohesion of the materials). We will also consider a possible science using a seismometer.