• Journal of the Korean Society for information Management
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• v.39 no.2
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• pp.111-129
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• 2022

Insomnia is a chronic disease in modern society, with the number of new patients increasing by more than 20% in the last 5 years. Insomnia is a serious disease that requires diagnosis and treatment because the individual and social problems that occur when there is a lack of sleep are serious and the triggers of insomnia are complex. This study collected 5,699 data from 'insomnia', a community on 'Reddit', a social media that freely expresses opinions. Based on the International Classification of Sleep Disorders ICSD-3 standard and the guidelines with the help of experts, the insomnia corpus was constructed by tagging them as insomnia tendency documents and non-insomnia tendency documents. Five deep learning language models (BERT, RoBERTa, ALBERT, ELECTRA, XLNet) were trained using the constructed insomnia corpus as training data. As a result of performance evaluation, RoBERTa showed the highest performance with an accuracy of 81.33%. In order to in-depth analysis of insomnia social data, topic modeling was performed using the newly emerged BERTopic method by supplementing the weaknesses of LDA, which is widely used in the past. As a result of the analysis, 8 subject groups ('Negative emotions', 'Advice and help and gratitude', 'Insomnia-related diseases', 'Sleeping pills', 'Exercise and eating habits', 'Physical characteristics', 'Activity characteristics', 'Environmental characteristics') could be confirmed. Users expressed negative emotions and sought help and advice from the Reddit insomnia community. In addition, they mentioned diseases related to insomnia, shared discourse on the use of sleeping pills, and expressed interest in exercise and eating habits. As insomnia-related characteristics, we found physical characteristics such as breathing, pregnancy, and heart, active characteristics such as zombies, hypnic jerk, and groggy, and environmental characteristics such as sunlight, blankets, temperature, and naps.

• The Journal of Engineering Geology
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• v.32 no.2
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• pp.257-270
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• 2022

This study evaluated the hydraulic factors contributing to the decreasing groundwater levels across Jeju island. Time-series data for groundwater level, precipitation, and groundwater usage and information on land use were acquired, and the correlations among them were analyzed to evaluate the causes of the decreasing groundwater. The effects of precipitation and groundwater usage on the fluctuations of groundwater level were quantified using response surface analysis and sensitivity analysis, and methods for groundwater quantity management by region were proposed. The results showed that the rate of groundwater decrease in the western region was larger than that in the eastern region. For the eastern region, the influence of precipitation was large and the rate of decrease in the groundwater level was relatively small. The geological formation of this part of the island and continuous seawater intrusion suggest that although the absolute amount of groundwater extracted for use was large, the decrease in the groundwater level was not seen to be great due to an increase in pressure by seawater intrusion. Overall, precipitation and groundwater usage had the greatest effect on the amount of groundwater in the western region, and thus their data would be most useful for informing groundwater management, whereas other factors (e.g., sea level and the location of the freshwater-seawater transition zone) must be considered when understanding Jeju's eastern region. As the characteristics of groundwater level fluctuations in the eastern and western regions are distinct, an optimal management plan for each region should be proposed to ensure the efficient management of groundwater quantity.

• Korean Journal of Mineralogy and Petrology
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• v.35 no.2
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• pp.101-109
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• 2022

The mobility and transport of radioactive cesium are crucial factors to consider for the safety assessment of high-level radioactive waste disposal sites in granite. The retardation of radionuclides in the fractured crystalline rock is mainly controlled by the hydrochemical condition of groundwater and surface reactions with minerals present in the fractures. This paper reports the experimental results of cesium sorption to the Wonju Granite, a typical Mesozoic granite in Korea, performed in an anaerobic chamber that mimics the anoxic environment of a deep disposal site. We measured the rates and amounts of cesium (¹³³Cs) removed by crushed granite samples in different electrolyte (NaCl, KCl, and CaCl₂) solutions and a synthetic groundwater solution, with variations in the initial cesium concentration (10^-5, 5×10^-6, 10^-6, 5×10^-7 M). The cesium sorption kinetic and isotherm data were successfully simulated by the pseudo-second-order kinetic model (r²= 0.99) and the Freundlich isotherm model (r²= 0.99), respectively. The sorption distribution coefficient of granite increased almost linearly with increasing biotite content in granite samples, indicating that biotite is an effective cesium scavenger. The cesium removal was minimal in KCl solution compared to that in NaCl or CaCl₂ solution, regardless of the ionic strength and initial cesium concentration that we examined, showing that K⁺ is the most competitive ion against cesium in sorption to granite. Because it is the main source mineral of K⁺ in fracture fluids, biotite may also hinder the sorption of cesium, which warrants further research.

• Journal of The Korean Association For Science Education
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• v.42 no.3
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• pp.311-324
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• 2022

This study analyzed the types of scientific emoticons made by science-gifted elementary school students and their perceptions on making scientific emoticons. To do this, 71 students from 4th to 6th graders of two gifted science education center in Seoul were selected. Scientific emoticons made by the students were analyzed according to the number and types. Their perceptions on making scientific emoticons were also analyzed through a questionnaire and group interviews. In the analyses for types of text in the scientific emoticons, 'word type' and 'sentence type' were made more than 'question and answer type'. And the majority of students made more 'pun using pronunciation type' and 'mixed type' than other types. They also made more 'graphic type' and 'animation type' than 'text type' in the images of the scientific emoticons. In the analyses for the information of the scientific emoticons, 'positive emotion type' and 'negative emotion type' of scientific emoticons were made evenly. The students made more 'new creation type' than 'partial correction type' and 'entire reconstruction type'. They also used scientific knowledge that preceded the knowledge of science curriculum in their grade level. The scientific knowledge of chemistry was used more than physics, biology, earth science, and combination field. 'Name utilization type' was more than 'characteristic utilization type' and 'principle utilization type'. Students had various positive perceptions in making scientific emoticons such as 'increase of scientific knowledge', 'increase of various higher-order thinking abilities', 'ease of explanation, use, memory, and understanding of scientific knowledge', 'increase of fun, enjoyment, and interest about science and science learning', and 'increase of opportunity to express emotions'. They were also aware of some limitations related to 'difficulties in the process of making scientific emoticons', 'lack of time', and 'limit that it may end just for fun'. Educational implications of these findings are discussed.

• Korean Journal of Environment and Ecology
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• v.36 no.3
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• pp.338-349
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• 2022

This study aims to investigate whether modular community planting, which entailed planting a variety of species of seedlings at high density, was more effective in restoring natural forests than the existing mature tree planting. We also investigated whether the planting density of the modular community planting facilitates growth or improves the tree layer coverage. We conducted outdoor experiments in which the samples were divided into a mature tree planting plot (control plot), where mature trees were planted at wide intervals, and a modular community planting (MCP) plot (treatment plot), where multiple seedlings were planted in high density. The MCP plot was further divided into the plot in which 3 seedlings were planted per m² and the plot of 1 seedling per m². We measured the specimens' survival rate, growth rate (tree height, crown width, and root collar diameter), and cover rate for 26 months from May 2019 and the predicted future tree height growth using the measured tree height. The survival rate and relative growth rate of the MCP were higher than those of the mature tree planting plot. The vertical coverage rate of the tree crown in the MCP exhibited complete coverage of the ground before 23 months, while the coverage rate of the mature tree planting decreased due to transplantation stress. The seedlings in the MCP, which were planted at high density, grew well and were predicted to grow higher than the mature trees in the large tree planting plot within 5 to 6.5 years after planting. It was due to multiple species, seedlings, high-density planting, and planting foundation improvements, such as soil enhancement and mulching. In other words, the seedlings planted in the MCP had a higher survival rate as their environmental adaptation after planting was better, and their early growth was also larger than the trees in the mature planting plot. The high-density mixed planting of various native species not only mitigated the inter-complementary environmental pressures but also facilitated growth by inducing competition between species. Moreover, the planting foundation improvement effectively increased the seedlings' viability and growth rate. A reduction in follow-up management costs is expected as the tree layer coverage sharply increases due to the higher planting density. In the MCP (3 seedlings per m² and 1 seedling per m²), the tree height growth was promoted with the higher planting density, and the crown width and root collar diameter tended to be larger with the lower planting density, but these differences were not statistically significant.

• The Journal of Korean Society for Radiation Therapy
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• v.33
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• pp.109-116
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• 2021

Purpose: The purpose of this study is to evaluate the usefulness of Surface-Guided Patient Setup by comparing the patient positioning accuracy when image-guided radiation therapy was used for Markerless patients(unmarked on the skin) using Surface-Guided Patient Setup and Marker patients(marked on the skin) using Laser-Based Patient Setup. Materials And Methods: The position error during IGRT was compared between a Markerless patient initially set up with SGPS using an optical surface scanning system using three cameras and a Marker patient initially set up with LBPS that aligns the laser with the marker drawn on the patient's skin. Both SGPS and LBPS were performed on 20 prostate cancer patients and 10 Stereotactic Radiation Surgery patients, respectively, and SGPS was performed on an additional 60 breast cancer patients. All were performed IGRT using CBCT or OBI. Position error of 6 degrees of freedom was obtained using Auto-Matching System, and comparison and analysis were performed using Offline-Review in the treatment planning system. Result: The difference between the root mean square (RMS) of SGPS and LBPS in prostate cancer patients was Vrt -0.02cm, Log -0.02cm, Lat 0.01cm, Pit -0.01°, Rol -0.01°, Rtn -0.01°, SRS patients was Vrt 0.02cm, Log -0.05cm, Lat 0.00cm, Pit -0.30°, Rol -0.15°, Rtn -0.33°. there was no significant difference between the two regions. According to the IGRT standard of breast cancer patients, RMS was Vrt 0.26, Log 0.21, Lat 0.15, Pit 0.81, Rol 0.49, Rtn 0.59. Conclusion:. As a result of this study, the position error value of SGPS compared to LBPS did not show a significant difference between prostate cancer patients and SRS patients. In the case of additionally performed SGPS breast cancer patients, the position error value was not large based on IGRT. Therefore, it is considered that it will be useful to replace LBPS with SGPS, which has the great advantage of not requiring patient skin marking..

• Journal of the Korean Chemical Society
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• v.66 no.2
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• pp.78-85
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• 2022

Natural white clay was treated with 6 M of H₂SO₄ and heated at 80℃ for 6 h under mechanical stirring and the resulting acid active clay was used as an adsorbent for the removal of Cs⁺ in water. The physicochemical changes of natural white clay and acid active clay were observed by X-ray Fluorescence Spectrometry (XRF), BET Surface Area Analyser and Energy Dispersive X-line Spectrometer (EDX). While activating natural white clay with acid, the part of Al₂O₃, CaO, MgO, SO₃ and Fe₂O₃ was dissolved firstly from the crystal lattice, which bring about the increase in the specific surface area and the pore volume as well as active sites. The specific surface area and the pore volume of acid active clay were roughly twice as high compared with natural white clay. The adsorption of Cs⁺ on acid active clay was increased rapidly within 1 min and reached equilibrium at 60 min. At 25 mg L^- of Cs⁺ concentration, 96.88% of adsorption capacity was accomplished by acid active clay. The adsorption data of Cs⁺ were fitted to the adsorption isotherm and kinetic models. It was found that Langmuir isotherm was described well to the adsorption behavior of Cs⁺ on acid active clay rather than Freundlich isotherm. For adsorption Cs⁺ on acid active clay, the Langmuir isotherm coefficients, Q, was found to be 10.52 mg g^-1. In acid active clay/water system, the pseudo-second-order kinetic model was more suitable for adsorption of Cs⁺ than the pseudo-first-order kinetic model owing to the higher correlation coefficient R² and the more proximity value of the experimental value q_e,exp and the calculated value q_e,cal. The overall results of study showed that acid active clay could be used as an efficient adsorbent for the removal of Cs⁺ from water.

• The Journal of Korean Society for Radiation Therapy
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• v.33
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• pp.79-88
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• 2021

Objectives: Bolus, which combines 3D-bolus and Step-bolus, was produced and its usefulness is evaluated. Materials and Methods: A Bolus was manufactured with a thickness of 10mm and 5mm using a 3D printer (3D printer, USA), and a Step Bolus of 5mm was bonded to a 5mm thick bolus. In order to understand the characteristics of Step bolus and 3D bolus, the differences in relative electron density, HU value, and mass density of the two bolus were investigated. These two Bolus were applied to anthropomorpic phantom to confirm its effectiveness. After all contouring of the phantom, a treatment plan was established using the computed treatment planning system (Eclipse 16.1, Varian medical system, USA). Treatment plan was performed using electron beam 6MeV, nine dose measurement points were designated on the phantom chest, air-gap was measured at that point, and dose evaluation was performed at the same point for each bolus applied using a glass dosimeter (PLD). Results: Bolus, which combines 3D-bolus 5mm and Step-bolus 5mm, was manufactured and evaluated compared with 3D-bolus 1cm. The relative electron density of 3D Bolus was 1.0559 g/cm2 and the step Bolus was 1.0590 g/cm2, which was different by 0.01%, so the relative electron density was almost the same. In the lightweight measurement of air-gap, the combined bolus was reduced to 54.32% for all designated points compared to 3D-bolus. In the dose measurement using a glass dose meter (PLD), the consistency was high in phantom using combined bolus at most points except the slope point. Conclusion: Combined bolus made by combining 3D-bolus and Step-bolus has all the advantages of 3D-bolus and Step-bolus. In addition, by dose inaccuracy due to Air-gap, more improved dose distribution can be shown, and effective radiation therapy can be performed.

• Journal of Practical Agriculture & Fisheries Research
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• v.22 no.2
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• pp.99-114
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• 2020

In this study we examined the topic analysis and correlation analysis by text mining from the self introduction letter of freshman at Korea National College of Agriculture and Fisheries(KNCAF) in 2020. The analysis items of the 3rd question were and the 4th question were the motivation for applying to college, the academic plan and the career plan. The text mining to the 3rd question showed that the frequency of 'friends' was overwhelmingly high, followed by keywords such as 'thought', 'time', 'opinion', 'activity', and 'club'. In the 4th question, keyword frequency such as 'thought', 'agriculture', 'KNCAF', 'farm', 'father' was high. The result of association rules analysis for each question showed that the relationship with the highest support level, which means the frequency and importance of the rule, was the {friend} <=> {thought}, {thought} <=> {KNCAF}. The confidence level of a correlation between keywords was the highest in the rules of {teacher}=>{friend}, {agriculture, KNCAF}=>{thought}. Also the lift level that indicates the closeness of two words was the highest in the rules of {friend} <=> {teacher}, {knowledge} <=> {professional}. These keywords are found to play a very important roles in analyzing betweenness centrality and analyzing degree centrality between keywords. The results of frequency analysis and association analysis were visualized with word cloud and correlation graphs to make it easier to understand all the results.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.67 no.1
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• pp.17-26
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• 2022

Rice is one of the three major grains globally, and has been used as a staple food in Asian countries for a long time. In recent years, with the increase in the use of processed rice, the development and distribution of rice flour varieties have become a research focus. However, rice flour varieties are susceptible to pre-harvest sprouting (PHS). In this study, the optimal transplanting date for rice flour varieties for maximum yield production with PHS avoidance was examined. Four rice flour varieties with different maturity types (early maturing type, Garumi2 and medium-late maturing type, Seolgaeng, Hangaru, and Singil) were selected. The field experiment was conducted in Chuncheon (Central Plain area) and Cheorwon (Northern Plain area), Gangwon Province, Republic of Korea, from 2017 to 2019. The transplanting dates used were May 10, May 20, May 30, June 10, and June 20 in Chuncheon and April 30, May 10, May 20, May 30, and June 10 in Cheorwon. In Chuncheon, late transplantation decreased PHS in Garumi2. In Cheorwon, PHS in Garumi2 decreased with transplantation dates after May 20. The PHS decreased in Seolgaeng, Hangaru, and Singil with late transplantation in Chuncheon and Cheorwon. The optimal transplanting date for maximum yield production while avoiding PHS for Garumi2 was estimated to be June 10 in Chuncheon and May 25 in Cheorwon; for Seolgaeng, the optimal transplanting dates were May 20 in Chuncheon and May 15 in Cheorwon; for Hangaru, it was estimated to be May 30 in Chuncheon and May 15 in Cheorwon; and for Singil, the optimal dates were May 25 in Chuncheon and May 15 in Cheorwon.