• Proceedings of the Korea Water Resources Association Conference
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• 2020.06a
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• pp.394-394
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• 2020

최근 빈번히 발생하고 있는 슈퍼 태풍과 집중호우로 인해 크고 작은 침수피해가 발생하고 있다. 우리나라는 4대강 사업을 통해 주요 국가하천에 대한 정비를 마친 바 있으나 이후 지속적으로 변화하는 하천 환경에 대한 홍수예측 모형의 반영은 미비한 실정이었다. 따라서 본 연구에서는 낙동강 본류 및 지류의 최신 단면자료를 수집하여 수리학적 홍수예측모형에 반영하고자 하였다. 또한, 기존의 모형에 비해 정확도를 개선할 수 있는 방안을 모색하여 적용성을 검증하고 이를 반영한 수리학적 홍수예측 모형을 제시하고자 한다. 본 연구에서는 낙동강 본류 및 주요 지류에 대한 최신 횡단면 측량자료를 활용하여 1차원 수리학적 홍수예측 모형을 구축하고 2012년 태풍 산바 사상에 대한 검보정을 실시하였다. 대상구간은 안동조정지댐으로부터 낙동강 하구둑 하류 8km지점이며, 상류단 경계조건은 안동조정지댐 방류량을 입력하고 하류단 경계조건은 가덕도 조위관측소의 조위를 활용하였다. 또한, 반변천, 내성천, 위천, 감천, 금호강, 황강, 남강 등 7개 지류에 대한 하도를 하도추적이 가능한 네트워크 모형으로 구축함으로써 지류에 대한 홍수예보에 활용할 수 있도록 하였다. 낙동강 본류의 하도 길이는 340km, 824개의 단면으로 구성하였으며, 지류를 포함한 전체 하도 길이는 572km, 1,570개의 단면으로 구성하였다. 또한, 낙동강 본류에 위치한 8개의 다기능보와 지류에 위치한 횡단구조물의 반영을 위해 다기능보의 제원 및 하천기본계획을 참고하여 내부경계조건으로 활용하였다. 본 연구에서 구축된 낙동강 본류 및 지류의 수리학적 홍수예측 모형을 낙동강 유역에 대한 홍수주의보 및 홍수경보 등 홍수특보 발령 업무에 활용함으로써 정확한 홍수예보가 가능하도록 하였다.

• Journal of Biomedical Engineering Research
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• v.44 no.6
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• pp.482-487
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• 2023

The purpose of this study was to investigate changes in wrist extensor activity, pain, and grip strength before and after wearing a forearm strap in their 20s who complained of chronic lateral epicondylitis for more than 6 weeks. As a result of the study, there was an increase in wrist extensor activity on both the injured and non-injured sides after wearing the forearm strap, but this was not statistically significant. There was a statistically decrease in pain after wearing the forearm strap on the injured side, and a statistically significant increase in grip strength on both. After applying the forearm strap with pad, there was an increase in muscle activity of ECRB (extensor carpi radialis brevis) on both the injured and non-injured sides. This is thought to be due to the strap pad acting as a compressive force, reducing pain, and increasing muscle recruitment ability due to stability in wrist extension. However, considering that the number of study subjects is insufficient to generalize the results, additional supplementary research is deemed necessary.

• Neonatal Medicine
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• v.17 no.2
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• pp.193-200
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• 2010

Purpose: Feeding desaturation is a common problem among preterm infants which can result in prolonged hospital stays, longterm feeding difficulties and growth delay. The purpose of this study was to identify the characteristics of premature infants with feeding desaturation and to examine the effect of orocutaneous stimulation on oral feeding. Methods: During the first phase of this study, 125 extremely low birth weight infants were reviewed retrospectively. Characteristics between infants with feeding desaturation (n=34) and those without feeding desaturation (n=91) were examined. During the second phase, 29 infants recruited from March, 2009 to May, 2010 were subjected to orocutaneous stimulation. The results of orocutaneous stimulation were compared to a control group (n=81). Results: The first phase of the study revealed that extremely low birth weight infants with feeding desaturation were significantly lower in gestational ages at birth, and had lower 5 minute apgar scores, more gastroesophageal refluxes and bronchopulmonary dysplasia. Infants without feeding desaturation reached full enteral feeding significantly earlier and showed shorter duration of hospital stay. At the second phase, infants in the intervention group showed shorter days to achieve initiation of bottle feeding, shorter days in achievement of full bottle feeding, last episodes of feeding desaturation and length of hospital stay compared to the control group of similar characteristics. Conclusion: Orocutaneous stimulation among extremely low birth weight infants results in earlier achievement of full bottle feedings without episodes of feeding desaturation hence shortens the length of hospital stay.

• Journal of Hospice and Palliative Care
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• v.12 no.4
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• pp.194-198
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• 2009

Department of Internal Medicine, The Catholic University of Korea College of Medicine, Seoul, Korea Purpose: Malignant bowel obstruction causes gastrointestinal symptoms and leads to diminished quality of life in patients with advanced cancer. Several studies have shown the efficacy of octreotide for the relief of malignant bowel obstruction-related symptoms. The aim of this study is to assess the efficacy and safety of octreotide in patients with malignant bowel obstruction. Methods: We retrospectively reviewed medical records of twenty nine patients who had suffered from malignant bowel obstruction without clinical improvement of conservative care and subsequently, received octreotide treatment. Initial dosage of octreotide was 0.1 mg/day, and dose was escalated depending on the clinical effect. For each patient, we assessed visual analogue scale (VAS) of pain, number of vomiting episode, and amount of nasogastric tube drainage. Results: Median dosage of octreotide was 0.2 mg/day (range 0.1~0.6), and median duration from initial medication to death was 20 days (range 2~103). VAS before and after octreotide treatment were 5.6$\pm$1.24, and 2.7$\pm$0.96, respectively. The numbers of vomiting episode before and after octreotide treatment were 3.6/day$\pm$2.5, and 0.4/day$\pm$0.8, respectively. The mean amounts of nasogastric tube drainage before and after octreotide treatment were 975$\pm$1,083 cc/day and 115$\pm$196 cc/day, respectively. Statistically significant reduction in VAS, the number of vomiting episode and the amount of nasogastric tube drainage were observed after octreotide treatment (P<0.05). Conclusion: Administration of octreotide in patients with malignant bowel obstruction, which is uncontrolled by other medication, was effective and safe. In such clinical situations, physicians should consider to add of octreotide for symptomatic control.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.26 no.1
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• pp.11-36
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• 2021

The solar annual (Sa) and semiannual (Ssa) tides account for much of the non-uniform annual and seasonal variability observed in sea levels. These non-equilibrium tides depend on atmospheric variations, forced by changes in the Sun's distance and declination, as well as on hydrographic conditions. Here we employ tidal harmonic analyses to calculate Sa and Ssa harmonic constants for 21 Korean coastal tidal stations (TS), operated by the Korea Hydrographic and Oceanographic Agency. We used 19 year-long (1999 to 2017) 1 hr-interval sea level records from each site, and used two conventional harmonic analysis (HA) programs (Task2K and UTide). The stability of Sa harmonic constants was estimated with respect to starting date and record length of the data, and we examined the spatial distribution of the calculated Sa and Ssa harmonic constants. HA was performed on Incheon TS (ITS) records using 369-day subsets; the first start date was January 1, 1999, the subsequent data subset starting 24 hours later, and so on up until the final start date was December 27, 2017. Variations in the Sa constants produced by the two HA packages had similar magnitudes and start date sensitivity. Results from the two HA packages had a large difference in phase lag (about 78°) but relatively small amplitude (<1 cm) difference. The phase lag difference occurred in large part since Task2K excludes the perihelion astronomical variable. Sensitivity of the ITS Sa constants to data record length (i.e., 1, 2, 3, 5, 9, and 19 years) was also tested to determine the data length needed to yield stable Sa results. HA results revealed that 5 to 9 year sea level records could estimate Sa harmonic constants with relatively small error, while the best results are produced using 19 year-long records. As noted earlier, Sa amplitudes vary with regional hydrographic and atmospheric conditions. Sa amplitudes at the twenty one TS ranged from 15.0 to 18.6 cm, 10.7 to 17.5 cm, and 10.5 to 13.0 cm, along the west coast, south coast including Jejudo, and east coast including Ulleungdo, respectively. Except at Ulleungdo, it was found that the Ssa constituent contributes to produce asymmetric seasonal sea level variation and it delays (hastens) the highest (lowest) sea levels. Comparisons between monthly mean, air-pressure adjusted, and steric sea level variations revealed that year-to-year and asymmetric seasonal variations in sea levels were largely produced by steric sea level variation and inverted barometer effect.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.17 no.4
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• pp.225-242
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• 2012

This is the first attempt to produce simultaneous surface current field from satellite altimeter data for the entire East Sea and to provide surface current information to users with formal description. It is possible to estimate surface geostrophic current field in near real-time because satellite altimeters and coastal tide gauges supply sea level data for the whole East Sea. Strength and location of the major currents and meso-scale eddies can be identified from the estimated surface geostrophic current field. The mean locations of major surface currents were explicated relative to topographic, ocean-surface and undersea features with schematic representation of surface circulation. In order to demonstrate the practical use of this surface current information, exemplary descriptions of annual, seasonal and monthly mean surface geostrophic current distributions were presented. In order to objectively classify surface circulation patterns in the East Sea, empirical orthogonal function (EOF) analysis was performed on the estimated 16-year (1993-2008) surface current data. The first mode was associated with intensification or weakening of the East Korea Warm Current (EKWC) flowing northward along the east coast of Korea and of the anti-cyclonic circulation southwest of Yamato Basin. The second mode was associated with meandering paths of the EKWC in the southern East Sea with wavelength of 300 km. The first and second modes had inter-annual variations. The East Sea surface circulation was classified as inertial boundary current pattern, Tsushima Warm Current pattern, meandering pattern, and Offshore Branch pattern by the time coefficient of the first two EOF modes.

• The Korean Journal of Pharmacology
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• v.31 no.3
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• pp.313-321
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• 1995

Conflicting data have been reported on the effect of nicotine on gastric mucosal damage. To elucidate the effect of chronic intermittent nicotine on gastric mucosal damage, intragastric nicotine (5 mg/kg, 10 mg/kg) was administered twice per day for 9 days. Gastric mucosal damage was created by s.c. injection of a large dose (1.2 mg/kg) of pentagastrin followed by pylorus ligation for 6 hours. Nicotine treated rats showed reduced gastric mucosal damage about 50% of the control. To examine the mechanism of the protective effect of nicotine, gastric perfusion experiments were done. Basal acid secretion was not affected by intragastric or intravenous nicotine. However, pentagastrin-stimulated acid secretion markedly inhibited by a bolus injection of nicotine, and this response was dose-related. These data indicates that chronic intermittent administration of nicotine protects gastric mucosa against gastrin-induced gastric mucosal damage, and nicotine-induced inhibition of gastrin-stimulated acid secretion has an important role for the protective effect of nicotine. Considering reports concerning nicotine's aggravating effect on the gastric mucosal damage, it is suggested that the methods of administration of nicotine may be an important decisive factor of the divergent action of nicotine on the gastric mucosa.

• Journal of the Korean Society of Marine Environment & Safety
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• v.26 no.2
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• pp.186-194
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• 2020

In this study, spectral analysis was conducted to identify environmental factors af ecting short-term changes in water temperature in the East, West and South coasts of Korea. The data used in the spectrum analysis is the 2016 summer water temperature, air temperature, tide level and wind data provided by Korea Hydrographic & Oceanographic Agency. In power spectrum results, peaks of water temperature and tide level were observed at same periods in West Sea (Incheon, Pyeungteak, Gunsan and Mokpo) and South Sea (Wando, Goheung, Yeosu, Tongyeong and Masan) where mean tidal range was more than 100 cm. On the other hand, periodicity of water temperature did not appear in East Sea and Busan where the mean tidal range was small. Coherence analysis showed that water temperature was highly correlated with tide in West Sea and three stations(Wando, Goheung and Tongyeong) of South Sea. Especially, correlation between water temperature and tide level in Wando and Tongyeong presented 0.96 at semi-diurnal period. Water temperature in Yeosu seems to have influenced by tide and inflow of fresh water. In Masan, water temperature is influenced by south wind, tide and inflow of fresh water. In East Sea, influence of tide on water temperature is small due to current and small tidal range. As a result of comparing the time series graph, stations where the correlation between water temperature and tide is high show that relatively cold water was inputted at flood tide and flow out at ebb tide. short-term variation of water temperature was affected by tide, but long-term variation over a month was affected by air temperature.

• Journal of Wetlands Research
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• v.18 no.2
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• pp.121-131
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• 2016

The determination of feasible design flood is the most important to control flood damage in river management. Concentration time and storage constant in the Clark unit hydrograph method mainly affects magnitude of peak flood and shape of hydrograph. Model parameters should be calibrated using observed discharge but due to deficiency of observed data the parameters have been adopted by empirical formula. This study is to suggest concentration time and storage constant based on the observed rainfall-runoff data at GongDo stage station in the Ansung river basin. To do this, five criteria have been suggested to compute root mean square error(RMSE) and residual of oserved value and computed one. Once concentration time and storage constant have been determined from three rainfall-runoff event selected at the station, the five criteria based on observed hydrograph and computed hydrograph by the Clark model have been computed to determine the value of concentration time and storage constant. A criteria has been proposed to determine concentration time and storage constant based on the results of the observed hydrograph and the Clark model. It has also been shown that an exponent value of concentration time-cumulative area curve should be determined based on the shape of watershed.

• Proceedings of the Korea Water Resources Association Conference
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• 2008.05a
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• pp.102-106
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• 2008

This study is to evaluated the impact of varying spatial resolutions of DEM (2 m, 10 m, and 30 m), land use (QuickBird, 1/25,000 and Landsat), and soil data (1/25,000 and 1/50,000) on the uncertainty of Soil and Water Assessment Tool (SWAT) predicted streamflow, sediment, T-N, and T-P transport in a small agricultural watershed ($1.21\;km^2$). SWAT model was adopted and the model was calibrated for a $255.4\;km^2$ watershed using 30 m DEM, Landsat land use, and 1/25,000 soil data. The model was run with the combination of three DEM, land use, and soil map respectively. The SWAT model was calibrated for 2 years (1999-2000) using daily streamflow and monthly water quality (SS, T-N, T-P) records from 1999 to 2000, and verified for another 2 years (2001-2002). The average Nash and Sutcliffe model efficiency was 0.59 for streamflow and the root mean square error were 2.08, 4.30 and 0.70 tons/yr for sediment, T-N and T-P respectively. The hydrological results showed that output uncertainty was biggest by spatial resolution of land use. Streamflow increase the watershed average CN value of QucikBird land use was 0.4 and 1.8 higher than those of 1/25,000 and Landsat land use caused increase of streamflow.