• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2023년도 학술발표회
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• pp.173-173
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• 2023

The Mekong River Basin (MRB) is a crucial watershed in Asia, impacting over 60 million people across six developing nations. Accurate satellite-based precipitation products (SPPs) are essential for effective hydrological and watershed management in this region. However, the performance of SPPs has been varied and limited. The APHRODITE product, a unique gauge-based dataset for MRB, is widely used but is only available until 2015. In this study, we present a novel framework for correcting SPPs in the MRB by employing a deep learning approach that combines convolutional neural networks and encoder-decoder architecture to address pixel-by-pixel bias and enhance accuracy. The DLF was applied to four widely used SPPs (TRMM, CMORPH, CHIRPS, and PERSIANN-CDR) in MRB. For the original SPPs, the TRMM product outperformed the other SPPs. Results revealed that the DLF effectively bridged the spatial-temporal gap between the SPPs and the gauge-based dataset (APHRODITE). Among the four corrected products, ADJ-TRMM demonstrated the best performance, followed by ADJ-CDR, ADJ-CHIRPS, and ADJ-CMORPH. The DLF offered a robust and adaptable solution for bias correction in the MRB and beyond, capable of detecting intricate patterns and learning from data to make appropriate adjustments. With the discontinuation of the APHRODITE product, DLF represents a promising solution for generating a more current and reliable dataset for MRB research. This research showcased the potential of deep learning-based methods for improving the accuracy of SPPs, particularly in regions like the MRB, where gauge-based datasets are limited or discontinued.

• 국제학술발표논문집
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• The 1th International Conference on Construction Engineering and Project Management
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• pp.655-661
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• 2005

For a hydro power plant project, the headrace tunnel having a finished diameter of 3.3m was constructed in volcanic rocks with well-developed vertical joint and high groundwater table. The intake facility was located 20.3 km upstream of the powerhouse and headrace tunnel of 20 km in length and penstock of 440 m in height connected the intake and the powerhouse. The typical caldera lake, Lake Toba set the geology at the site; the caving of the ground caused tension cracks in the vertical direction to be developed and initial stresses at the ground to be released. High groundwater table(the maximum head of 20 bar) in the area of well-connected vertical joints delayed the progress of tunnel excavation severely due to the excessive inflow of groundwater. The excavation of tunnel was made using open-shield type TBM and mucking cars on the rail. High volume of water inflow raised the water level inside tunnel to 70 cm, 17% of tunnel diameter (3.9 m) and hindered the mucking of spoil under water. To improve the productivity, several adjustments such as modification of TBM and mucking cars and increase in the number of submersible pumps were made for the excavation of severe water inflow zone. Since the ground condition encountered during excavation turned out to be much worse, it was decided to adopt PC segment lining instead of RC lining. Besides, depending on the conditions of the water inflow, rock mass condition and internal water pressure, one of the invert PC segment lining with in-situ RC lining, RC lining and steel lining was applied to meet the site specific condition. With the adoption of PC segment lining, modification of TBM and other improvement, the excavation of the tunnel under severe groundwater condition was successfully completed.

• 한국건축시공학회지
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• 제23권2호
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• pp.209-220
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• 2023

먹매김 로봇은 허용오차 이내의 정밀도를 확보하는 것이 매우 중요하다. 그러나 골조공사는 시공과정에서 철근배근의 변위가 빈번하게 발생하며, 해당오차는 먹선이나 철근위치의 수정을 요구한다. 먹매김 로봇은 정밀도 확보 및 자동화를 위해 철근의 오차를 측정하고 먹선과 철근의 수정을 스스로 판단할 수 있어야 한다. 이에 본 연구는 LiDAR 센서를 통한 철근배근의 오차 측정방안과 이를 바탕으로 먹매김 판단 프로세스를 제시하였다. LiDAR 센서를 활용한 철근인식 실험결과 평균적으로 5mm 내외의 오차를 발생하였으며, 이는 일반적으로 벽체에 적용되는 철근 수준에서 인식을 신뢰할만한 수준으로 나타났다. 또한 철근오차를 범위별로 판단하여 철근의 보정여부와 먹매김의 수행여부를 로봇이 스스로 판단할 수 있는 프로세스를 제시하였다. 본 연구결과는 시공오차를 고려한 먹매김로봇의 자동운영에 기여할 수 있으며 이를 통해 골조품질을 향상시킬 수 있을 것으로 기대된다.

• 운동영양학회지
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• 제13권2호
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• pp.155-160
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• 2009

PURPOSE. The purpose of this study was to investigate the effects of fasting and high-fat diet feeding on uncoupling protein 3 (UCP3) mRNA levels, uncoupling the respiratory chain and producing heat, of skeletal muscle in rat. METHODS. Fasting experiment: Forty Male Sprague-Dawley rats (5 wk) were divided into non-fasting groups (CON) and fasting groups (FG) for 0 day, 0.5 day (12 hr), 1 day, 2 day and 3 day. The rats of CON were sacrificed at 0 and 3 day. High-fat diet experiment: Forty Male Sprague-Dawley rats (5 wk) were divided into low-fat diet groups (LF) and high-fat diet group feeding for 0 day, 0.5 day (12 hr), 1 day, 2 day and 3 day. The rats of LF were sacrificed at 0 and 3 day. Analysis: Analysis of UCP3 mRNA expression was used by Real-time PCR. RESULTS. UCP3 mRNA levels of FG group were increased according to time course for 2 days- fasting but decreased at 3 day-fasting. UCP3 mRNA of HF were increased during HF diet feeding for 2 day, and peaked at 1 day-HF feeding, but decreased 2 day and 3 day-HF feeding CONCLUSION. Therefore, it may be rational that UCP3 is up-regulation when a large amount of fatty acids influx occurs in skeletal muscles as well as might have a role for fine adjustments of energy expenditure.

• 대한방사선기술학회지:방사선기술과학
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• 제46권4호
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• pp.295-301
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• 2023

In addition to protocol adjustments during CT examinations, the height of the CT table can also affect image quality. Therefore, this study aimed to investigate the change in image quality depending on the height of the table in brain CT, which accounts for a large proportion of CT examinations, by measuring signal to contrast to noise ratio (CNR) and noise power spectrum (NPS) using the head phantom and evaluating them. The head phantom images were acquired using Philips Brilliance iCT 256. When the image was acquired, the table height was adjusted to 815, 865, 915, 965, 1015, and 1030 mm, respectively, and each scan was performed 3 times for each height. The CNR result showed the highest value at 965 mm, which is the height adjacent to the center of the head phantom. NPS showed the lowest NPS at 915 mm, the center of the head phantom in the low frequency region. From these results, it can be seen that the height of the table in CT examination is closely related to the image quality, and it can be seen the characteristics of image quality according to CT table through quantitative evaluation methods such as CNR and NPS.

• 무역학회지
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• 제48권2호
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• pp.1-26
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• 2023

본 연구는 자회사가 현지시장 적응과 시장변화에 대한 대응으로서 내부능력의 재조정을 실시하며, 나아가 조직 내·외부의 네트워크를 활용하는 것이 투자성과에 어떠한 영향을 미치는 실증하는데 연구목적을 둔다. 실증결과로부터 자회사의 내부능력 조정 크기가 클수록, 이를 신속하고 유연적으로 실행할수록 투자성과에 긍정적 효과가 발생함을 입증하였다. 이 과정에서 네트워크 내부배태성의 활용과, 네트워크 외부배태성의 활용이 투자성과에 긍정적 매개자로서 역할을 하는 것도 입증하였다. 또한 중국시장에 진출한 다국적제조기업에게는 외부배태성의 매개효과의 크기가 내부배태성의 매개효과 크기보다 더 클 것이라는 연구가설에 대해 통계분석 결과가 지지하는 것으로 나타났다. 이러한 분석결과는 자회사 최고경영자에게는 현지 정보의 탐색과 접근, 현지 제도에 적응 등 외국비용 절감 전략을 수립하는 것과 함께 자회사가 현지에서 새로운 지리적 경쟁우위를 창출하는 데 외부배태성을 적극적으로 활용해야 한다는 시사점을 제공한다.

• Journal of Ecology and Environment
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• 제47권3호
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• pp.103-116
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• 2023

Background: This study analyzed the physiological adaptations of a woody plant, Vitex rotundifolia, in Goraebul coastal sand dunes from May to September 2022. Environmental factors and physiological of plants growing under field and controlled (pot) conditions were compared. Results: Photosynthesis in plants growing in the coastal sand dunes and pots was the highest in June 2022 and July 2022, respectively. Chlorophyll fluorescence indicated the presence of stress in the coastal sand dune environment. The net photosynthesis rate (P_N) and Y(II) were highest in June in the coastal sand dune environment and July in the pot environment. In August and September, Y(NPQ) increased in the plants in the coastal sand dune environment, showing their photoprotective mechanism. Chlorophyll a and b contents in the pot plant leaves were higher than those in the coastal sand dune plant leaves; however, chlorophyll-a/b ratio was higher in the coastal sand dune plant leaves than in the pot plant leaves, suggesting a relatively high photosynthetic efficiency. Carotenoid content in the coastal sand dune plant leaves was higher in August and September 2022 than that in the pot plant leaves. Leaf water and soluble carbohydrate contents of the coastal sand dune plant leaves decreased in September 2022, leading to rapid leaf abscission. Diurnal variations in photosynthesis and chlorophyll fluorescence in both environments showed peak activity at 12:00 hour; however, the coastal sand dune plants had lower growth rates and Y(II) than the pot plants. Plants in the coastal sand dunes had higher leaf water and ion contents, indicating that they adapted to water stress through osmotic adjustments. However, plants growing in the coastal sand dunes exhibited reduced photosynthetic activity and accelerated decline due to seasonal temperature decreases. These findings demonstrate the adaptation mechanisms of V. rotundifolia to water stress, poor soils, and high temperature conditions in coastal sand dunes. Conclusions: The observed variations indicate the responses of the V. rotundifolia to environmental stress, and may reveal its survival strategies and adaptation mechanisms to stress. The results provide insights into the ecophysiological characteristics of V. rotundifolia and a basis for the conservation and restoration of damaged coastal sand dunes.

• 한국의류학회지
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• 제47권5호
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• pp.839-852
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• 2023

This study examined personal protective clothing, specifically the D (M, L, XL) and C (L, XL, 2XL) levels with high sales rates. The goal was to collect essential data for developing Korean personal protective clothing. There were eight and twelve patterns for the D-level and C-level, respectively. While the pattern dimensions were similar, the chest and waist circumferences (relaxed) were larger in the C-level, and the waist (extended), hip, upper arm circumference, and total lengths were larger in the D-level. The D-level wear sensation worked well for average-sized Koreans in their twenties, but the C-level caused discomfort in multiple areas, such as the face, arms, armpits, hips, crotch, thighs, and knee during movement. Consequently, this region required pattern adjustments and resetting for improved comfort. The grading rules were 10 cm in the chest, waist, and hip circumference, regardless of the level, with slight differences in other parts depending on the levels. Thus, manufacturers should establish new grading rules to suit the Korean body shape.

• Journal of Preventive Medicine and Public Health
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• 제56권5호
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• pp.458-466
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• 2023

Objectives: The association between long sleep duration and mortality is frequently attributed to the confounding influence of comorbidities. Nevertheless, past efforts to account for comorbidities have yielded inconsistent outcomes. The objective of this study was to evaluate this relationship using a large prospective cohort in Korea. Methods: The study included 114 205 participants from the Health Examinees Study, who were followed for a median of 9.1 years. A composite comorbidity score was developed to summarize the effects of 21 diseases. Using Cox proportional hazards regression, hazard ratios (HRs) and 95% confidence intervals (CIs) for all-cause, cancer, and cardiovascular mortality associated with sleep duration were estimated. These estimates were adjusted for socio-demographic factors, lifestyle factors, body mass index, and comorbidity score. Additionally, a stratified analysis by subgroups with and without comorbidities was conducted. Results: Throughout the follow-up period, 2675 deaths were recorded. After all adjustments, an association was observed between a sleep duration of 8 hours or more and all-cause mortality (HR, 1.10; 95% CI, 1.01 to 1.20). However, no such association was detected in the stratified analysis for the subgroups based on comorbidity status. Conclusions: Long sleep duration was found to be associated with all-cause mortality among Koreans, even after adjusting for comorbidities. Additional studies are required to explore the mechanism underlying the association between sleep duration and major causes of mortality.

• 대한심미치과학회지
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• 제32권1호
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• pp.23-32
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• 2023

비기능적 습관을 가진 환자는 턱관절 장애, 저작 근육의 근막통증증후군 등과 함께 치아의 광범위한 마모를 유발한다. 지속되는 교모는 수직교합고경의 감소를 동반하게 되며 이는 안모의 변화, 저작 효율 저하, 측두하악 관절 장애 등의 문제가 발생할 수 있다. 이런 수직교합고경 감소 환자의 3차원적인 교합 회복과 재구성을 위해서는 정확한 진단 및 분석과 예지성 있는 치료계획 수립이 필요하며, 생리적인 수직교합고경의 회복 및 정상적인 교합평면 재설정을 동반한 보철치료가 필요하다. 본 증례는 구강 악습관에 의한 전반적인 치아의 마모와 저작근의 불편감, 그리고 수직교합고경 감소로 인한 심미적 불만족을 호소하는 환자의 수직교합고경 증가를 동반한 완전 구강 회복 증례이다. 교합안정장치를 통한 측두하악관절의 안정과 고딕아치 기록장치를 이용한 악간관계 재설정 및 임시 수복물을 통한 경과 관찰을 통해 기능적, 심미적으로 좋은 결과를 보였기에 이를 보고하고자 한다.