• Korean Journal of Soil Science and Fertilizer
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• v.43 no.6
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• pp.804-811
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• 2010

The lower portion of sloping paddy fields normally contains excessive moisture and the higher water table caused by the inflow of ground water from the upper part of the field resulting in non-uniform water content distribution. Four drainage methods namely Open Ditch, Vinyl Barrier, Pipe Drainage and Tube Bundle for multiple land use were installed within 1-m position from the lower edge of the upper embankment of sloping alluvial paddy fields. Knowledge of the spatial variability of soil water properties is of primary importance for management of agricultural lands. This study was conducted to evaluate the effect of drainage in the soil on spatial variability of soil water content using the geostatistical analysis. The soil water content was collected by a TDR (Time Domain Reflectometry) sensor after the installation of subsurface drainage on regular square grid of 80 m at 20 m paddy field located at Oesan-ri, Buk-myeon, Changwon-si in alluvial slopping paddy fields ($35^{\circ}22^{\prime}$ N, $128^{\circ}35^{\prime}$). In order to obtain the most accurate field information, the sampling grid was divided 3 m by 3 m unit mesh by four drainage types. The results showed that spatial variance of soil water content by subsurface drainage was reduced, though yield of soybean showed the same trends. Value of "sill" of soil water content with semivariogram was 9.7 in Pipe Drainage, 86.2 in Open Ditch, and 66.8 in Vinyl Barrier and 15.7 in Tube Bundle.

• Korean Journal of Psychosomatic Medicine
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• v.24 no.1
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• pp.74-82
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• 2016

Objectives : Suicide attempters have impaired decision making and are at high risk of reattempt. Therefore it is important to refer them to psychiatric treatment. Especially, People with medical comorbidity are at higher risk of suicidal attempt and mortality. The aim of this study was to investigate the characteristics of suicidal attempters and to analyze the influence of the medical comorbidity on decision to receive psychiatric treatment after visit to an emergency department. Methods : One hundred and thirty two patients, who visited the emergency room of a general hospital in Gyeonggi-do between January, 2012 and December, 2012 were enrolled as the subjects of this study. After reviewing each subject's medical records retrospectively, demographic and clinical factors were analyzed. Results : Regardless of the engagement type, either via admission or outpatient clinic, the determinant factors of psychiatric treatment engagement were psychiatric diagnosis, employment status, previous psychiatric treatment history, and previous attempt history. Comparison of severity of medical comorbidity(Charlson Comorbidity Index) showed that suicide attempters who received psychiatric treatment via admission or refused the treatment tended to have higher level of medical comorbidity than who received psychiatric treatment via outpatient department. Conclusions : Our findings showed that medical comorbidity of suicide attempters affected the decision to accept psychiatric treatment. All psychiatrists should evaluate the presence and the severity of medical comorbidity of the suicide attempters and consider implementing more intervention for the medically ill attempters who are willing to discharge against advice.

• Journal of Korean Tunnelling and Underground Space Association
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• v.24 no.6
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• pp.617-628
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• 2022

A ground support pattern should be designed by properly integrating various support materials in accordance with the rock mass grade when constructing a tunnel, and a technical decision must be made in this process by professionals with vast construction experiences. However, designing supports at the early stage of tunnel design, such as feasibility study or basic design, may be very challenging due to the short timeline, insufficient budget, and deficiency of field data. Meanwhile, the design of the support pattern can be performed more quickly and reliably by utilizing the machine learning technique and the accumulated design data with the rapid increase in tunnel construction in South Korea. Therefore, in this study, the design data and ground exploration data of 48 road tunnels in South Korea were inspected, and data about 19 items, including eight input items (rock type, resistivity, depth, tunnel length, safety index by tunnel length, safety index by rick index, tunnel type, tunnel area) and 11 output items (rock mass grade, two items for shotcrete, three items for rock bolt, three items for steel support, two items for concrete lining), were collected to automatically determine the rock mass class and the support pattern. Three machine learning models (S1, A1, A2) were developed using two machine learning algorithms (SVR, ANN) and organized data. As a result, the A2 model, which applied different loss functions according to the output data format, showed the best performance. This study confirms the potential of support pattern design using machine learning, and it is expected that it will be able to improve the design model by continuously using the model in the actual design, compensating for its shortcomings, and improving its usability.

• Korean Journal of Food Science and Technology
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• v.53 no.6
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• pp.749-755
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• 2021

The objective of this study was to investigate the physicochemical properties of rice starch extracted from stale rice using alkaline steeping (AKL) and improved enzymatic digestion (iENZ) methods. The crude protein content (0.5-0.7%) of stale rice starch (SRS) was less than 1% by iENZ, but not so when measured by the existing ENZ methods. SRS is an intermediate amylose rice starch. AKL-SRS and iENZ-SRS exhibited typical A-type crystal packing arrangements with similar relative crystallinities. iENZ-SRS showed higher gelatinization onset and peak temperatures with a narrower gelatinization temperature range, compared to those of AKL-SRS, indicating that iENZ annealed SRS. Thus, iENZ-SRS exhibited lower swelling power and solubility, and higher pasting viscosities with delayed viscosity development. Overall, the use of stale rice as a rice starch source could make economical production of rice starch possible, and iENZ may diversify rice starch characteristics, which expands the utilization of rice starch in food and non-food industries.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.66 no.3
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• pp.240-247
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• 2021

Anthocyanins are known to be involved in various functions such as antioxidant and antibacterial activities in plants. Although studies on anthocyanins in corn have been conducted recently, basic research related to anthocyanin biosynthesis is insufficient. In this study, we examined the molecular biological and physicochemical properties related to anthocyanin biosynthesis in the tassel and silks of Gwangpyeongok and Dacheongok cultivars. Anthocyanins were not synthesized in either the tassel or silks in Gwangpyeongok, whereas were synthesized in both in Dacheongok. The total anthocyanin content was approximately 30 times higher in the tassel and silks of Dacheongok than in those of Gwangpyeongok. In addition, C-3-G was measured only in the tassel of Dacheongok, and C-3-G, Pg-3-G, and M-3-G were 45.2 times, 27.3 times, and 37.6 times higher, respectively, in the silks of Dacheongok than of Gwangpyeongok. Expression of F3'H, DFR, and GST genes decreased in the tassel, and that of F3'H and DFR genes decreased in the silks of Gwangpyeongok. It was further confirmed that transcription factor P1 and R1 regulate the expression of anthocyanin biosynthetic genes in the tassel and silks, respectively, in Gwangpyeongok. Linoleic acid (C18:2) decreased by 6.6% and 10.9%, and linolenic acid (C18:3) increased by 8.5% and 8.5%, in the tassel and silks, respectively, of Gwangpyeongok compared to those of Dacheongok. Palmitic acid (C16:0) increased by 4.1% and oleic acid (C18:1) decreased by 2.1% in the silks of Gwangpyeongok compared to that in Dacheongok. In addition, the total fatty acid content in the tassel and silks increased by 10.3% and 30.4%, respectively, in Gwangpyeongok compared to that in Dacheongok. However, no significant results were observed in the analysis of phytosterol components. These results may be utilized as useful resources for the development of functional corn containing a large amount of anthocyanins.

• Korean Journal of Remote Sensing
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• v.37 no.5_1
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• pp.959-974
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• 2021

Forel-Ule Index (FUI) is an index which classifies the colors of inland and seawater exist in nature into 21 gradesranging from indigo blue to cola brown. FUI has been analyzed in connection with the eutrophication, water quality, and light characteristics of water systems in many studies, and the possibility as a new water quality index which simultaneously contains optical information of water quality parameters has been suggested. In thisstudy, Ocean Colour-Climate Change Initiative (OC-CCI) based 4 km FUI was spatially downscaled to the resolution of 500 m using the Geostationary Ocean Color Imager (GOCI) data and Random Forest (RF) machine learning. Then, the RF-derived FUI was examined in terms of its correlation with various water quality parameters measured in coastal areas and its spatial distribution and seasonal characteristics. The results showed that the RF-derived FUI resulted in higher accuracy (Coefficient of Determination (R²)=0.81, Root Mean Square Error (RMSE)=0.7784) than GOCI-derived FUI estimated by Pitarch's OC-CCI FUI algorithm (R²=0.72, RMSE=0.9708). RF-derived FUI showed a high correlation with five water quality parameters including Total Nitrogen, Total Phosphorus, Chlorophyll-a, Total Suspended Solids, Transparency with the correlation coefficients of 0.87, 0.88, 0.97, 0.65, and -0.98, respectively. The temporal pattern of the RF-derived FUI well reflected the physical relationship with various water quality parameters with a strong seasonality. The research findingssuggested the potential of the high resolution FUI in coastal water quality management in the Korean Peninsula.

• Journal of the Microelectronics and Packaging Society
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• v.28 no.3
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• pp.33-38
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• 2021

Recently, rollable and foldable displays are attracting great attention in the flexible display market due to their excellent form factor. To predict and prevent the mechanical failure of the display panels, it is essential to accurately understand the mechanical properties of brittle SiN_x thin films, which have been used as an insulating film in flexible displays. In this study, tensile properties of the ~130 nm- and ~320 nm-thick SiN_x thin films were successfully measured by coating a ~190 nm-thick organic nano-support-layer (PMMA, PS, P3HT) on the fragile SiN_x thin films and stretching the films as a bilayer state. Young's modulus values of the ~130 nm and ~320 nm SiN_x thin films fabricated through the controlled chamber pressure and deposition power (A: 1250 mTorr, 450 W/B: 1000 mTorr, 600 W/C: 750 mTorr, 700 W) were calculated as A: 76.6±3.5, B: 85.8±4.6, C: 117.4±6.5 GPa and A: 100.1±12.9, B: 117.9±9.7, C: 159.6 GPa, respectively. As a result, Young's modulus of ~320 nm SiN_x thin films fabricated through the same deposition condition increased compared to the ~130 nm SiN_x thin films. The tensile testing method using the organic nano-support-layer was effective in the precise measurement of the mechanical properties of the brittle thin films. The method developed in this study can contribute to the robust design of the rollable and foldable displays by enabling quantitative measurement of mechanical properties of fragile thin films for flexible displays.

• Korean Journal of Environment and Ecology
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• v.35 no.5
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• pp.438-479
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• 2021

Basic information such as flora and their distribution are the key factors to consider for preserving plant diversity on a regional level. The number of plant species identified through a survey is closely related to the survey area and the number of habitats distributed within the survey area. In this study, we surveyed the flora of Mt. Maryong-san (PH) and Mt. Daeso-san (YH) located in Uljin-gun, Gyeongsangbuk-do, six and nine times, respectively. We planned to include a variety of habitats in the survey routes. As a result, we identified a total of 594 taxa composing of 112 families, 349 genera, 548 species, 10 subspecies, 34 varieties, and 2 formulas in the Mt. Maryong-san (PH) area and a total of 434 taxa composing of 89 families, 270 genera, 400 species, 9 subspecies, and 25 varieties in the Mt. Daeso-san (YH) area. Of the plants observed in the 21 habitats, the plants distributed in the transition zone around the valley and the dry grassland accounted for the highest proportion. The traditional graveyards located on the coast also served as the major habitat for the distribution of some plant species. In the two graveyards, 19 taxa of endemic plant species were surveyed. Moreover, the identified floristic target species included 1 taxon for grade V, 11 taxa for grade IV, and 24 taxa for grade III. A total of 77 taxa of naturalized plants were identified, and four of them were invasive alien plants as designated by the Ministry of Environment. The differences in the plants distributed in the area of Mt. Maryong-san (PH) and Mt. Daeso-san (YH) were mainly due to the difference in the size of each habitat distributed within the survey area. Moreover, it was judged that the entire vicinity of Mt. Daeso-san (YH) was not connected to the surrounding mountains and was an isolated area surrounded by farmland and residential areas.

• Journal of Korea Water Resources Association
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• v.54 no.10
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• pp.795-805
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• 2021

In this study, after developing an LSTM-based deep learning model for estimating daily runoff in the Soyang River Dam basin, the accuracy of the model for various combinations of model structure and input data was investigated. A model was built based on the database consisting of average daily precipitation, average daily temperature, average daily wind speed (input up to here), and daily average flow rate (output) during the first 12 years (1997.1.1-2008.12.31). The Nash-Sutcliffe Model Efficiency Coefficient (NSE) and RMSE were examined for validation using the flow discharge data of the later 12 years (2009.1.1-2020.12.31). The combination that showed the highest accuracy was the case in which all possible input data (12 years of daily precipitation, weather temperature, wind speed) were used on the LSTM model structure with 64 hidden units. The NSE and RMSE of the verification period were 0.862 and 76.8 m³/s, respectively. When the number of hidden units of LSTM exceeds 500, the performance degradation of the model due to overfitting begins to appear, and when the number of hidden units exceeds 1000, the overfitting problem becomes prominent. A model with very high performance (NSE=0.8~0.84) could be obtained when only 12 years of daily precipitation was used for model training. A model with reasonably high performance (NSE=0.63-0.85) when only one year of input data was used for model training. In particular, an accurate model (NSE=0.85) could be obtained if the one year of training data contains a wide magnitude of flow events such as extreme flow and droughts as well as normal events. If the training data includes both the normal and extreme flow rates, input data that is longer than 5 years did not significantly improve the model performance.

• Knowledge Management Research
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• v.22 no.3
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• pp.217-233
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• 2021

Small business owners are currently greatly affected by the economic downturn caused by COVID-19. It is a study on the expected effect of education on management education of small business owners and the sustainability of the project on the premise that education can increase the self-sustainability of small business owners amid the rapidly changing global economy and consumer sentiment due to COVID-19. The following research results were derived by surveying those who completed management education of the Small Business Market Promotion Foundation. Management education was found to have a positive effect on education expectation effect, and education expectation effect was also found to have a positive effect on sustainability. In addition, management education had a positive effect on the sustainability of the project, and the expected effect of education was mediated between management education and sustainability. These results show that management education has a positive effect on survival and continuous performance in the business of small business owners, and steady efforts to acquire education can be said to be helpful in management activities. As a practical implication, first, since positive education expectations for management education can be seen as affecting the sustainability of the project, it should be possible to increase the expected effect by configuring interest and interest in education when forming management education programs. Second, management education directly affects the maintenance, survival, and sustainability of small business owners, and the knowledge acquired by participating in education helps improve management activities, so you can think of adding the amount and number of educational support. Third, since the sustainability of small business owners also affects the survival of the business, more active promotion of education will be needed so that more small business owners can receive management education.