• Journal of Korea Water Resources Association
• /
• v.53 no.11
• /
• pp.985-997
• /
• 2020

SWAT (Soil and Water Assessment Tool)-MODFLOW (Modular Groundwater Flow) is a coupled model that linking semi-distributed watershed hydrology with fully-distributed groundwater behavior. In this study, the groundwater simulation results of SWAT and SWAT-MODFLOW were compared for Bokhacheon watershed in Namhan river basin. The models were calibrated and validated with 9 years (2009~2017) daily streamflow (Q) data of Heungcheon (HC) water level gauge station and the daily groundwater level observation data of Yulheon (YH). For SWAT, the groundwater parameters of GW_DELAY, GWQMN, and ALPHA_BF affecting baseflow and recession phase were treated. The SWAT results showed the coefficient of determination (R²) of 0.7 and Nash-Sutcliffe model efficiencies (NES_Q, NSE_inQ) for Q and 1/Q with 0.73 and -0.1 respectively. For SWAT-MODFLOW, the spatio-temporal aquifer hydraulic conductivity (K, m/day), specific storage (S_s, 1/m), and specific yield (S_y) were applied. The SWAT-MODFLOW showed R², NSE_Q, and NSE_inQ of 0.69, 0.74, and 0.51 respectively. The SWAT-MODFLOW considerably enhanced the low flow simulation with the help of aquifer physical information. The total streamflow of SWAT and SWAT-MODFLOW were 718.6 mm and 854.9 mm occupying baseflow of 342.9 mm and 423.5 mm respectively.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2021.06a
• /
• pp.120-120
• /
• 2021

2020년 8월 7일부터 8월 8일까지 호우는 용담댐, 섬진강댐, 합천댐 하류 유역의 막대한 침수피해를 일으켰다. 이들 다목적 댐 유입량의 신뢰도 높은 모의는 홍수기 댐 운영 및 하류하천의 홍수 해석에 필수다. 여기서는 일 유출 모의 기반으로 개발된 ONE 모형을 10분 단위, 1시간 단위로 적용한 결과를 제시하고자 한다. 보통 홍수모의는 사상별로 실시하지만, 여기서는 1월1일부터 12월 31일까지 연속으로 모의한 결과에서 해당 홍수사상 결과를 제시하였다. 3개 다목적 댐의 홍수사상은 8월6일부터 8월 10일까지 5일간으로 설정하였다. 유역면적은 용담댐, 섬진강댐, 합천댐, 각각 930km², 763km², 925km², 총강우량은 각각 490.7mm, 451.9mm, 452.4mm, 첨두유입량은 10분 단위는 각각 4,872.7m³/s, 3,533.7.0m³/s, 2,776.0m³/s, 1시간 단위는 각각 4,394.9m³/s, 3,401.8m³/s, 2,745.6m³/s, 총유입량은 각각 3억8,836만m³, 3억1,324만m³, 3억2,816만m³였다. 첨두유입량 상대오차가 0일 때의 매개변수로 모의한 결과를 제시하며, 총유입량 상대오차(Vq), R², RMSE, NSE 등으로 평가하였다. 용담댐 결과는 10분 단위 경우 최대면적강우량 7.3mm, 첨두유입량 4,872.4m³/s, 총유입량 3억 8,138만m³, Vq 1.9%, R² 0.968, RMSE 207.347, NSE 0.978였고, 1시간의 경우 최대면적강우량 29.6mm, 첨두유입량 4394.9m³/s, 총유입량 4억157만m³, Vq -8.4%, R² 0.970, RMSE 186.962, NSE 0.982였다. 섬진강댐 결과는 10분 단위 경우 최대면적강우량 9.2mm, 첨두유입량 3,533.3m³/s, 총유입량 2억7,223만m³, Vq 18.4%, R² 0.885, RMSE 808.296, NSE 0.925였고, 1시간의 경우 최대 면적강우량 37.9mm, 첨두유입량 3401.6m³/s, 총유입량 2억7,029만m³, Vq 13.7%, R² 0.907, RMSE 285.544, NSE 0.936였다. 합천댐 결과는 10분 단위 경우 최대면적강우량 5.5mm, 첨두유입량 2,776.2m³/s, 총유입량 3억3,667만m³, Vq -2.7%, R² 0.941, RMSE 191.896, NSE 0.965였고, 1시간의 경우 최대면적강우량 17.0mm, 첨두유입량 2,746.7m³/s, 총유입량 3억1,333만m³, Vq 4.5%, R² 0.965, RMSE 140.739, NSE 0.981였다. 이상 ONE 모형으로 10분, 1시간 단위의 댐 홍수 유입량 모의결과는 높은 신뢰도를 나타냈다.

• Journal of Chest Surgery
• /
• v.25 no.8
• /
• pp.806-811
• /
• 1992

The primary neuroendocrine carcinomas[NEC] of the lung are relatively rare. There are classified histologically into the following groups. 1] bronchial carcinoid, 2] well differentiated neuroendocrine carcinoma[WDNC], 3] intermediate cell neuroendocrine carci-noma[ICNC], 4] small cell neuroendocrie carcinoma[SCNC]. The NE cells can be found throughout the mucosa of the bronchial tree by the electron microscopy. By the immunocytochemistry, Neuron-specific enolase[NSE], serotonin, born-csin, and calcitonin are found in normal solitary NE cells and neuroepithelial bodies. The immunohistochemistry has the advantage that it can be applied on routine pathology specimens. The NSE was localized in all of the NE granule bearing tumors but also present in 57 per cent of the non NE carcinomas. Together the combination of chromogranin A, bombesin and NSE should provide an exellent signature for tumor cells expressing NE features, such as carcinoids and other NE carcinomas. We have experienced two cases of primary pulmonary NEC in 59 and 29 years old men. The former was admitted due to exertional dyspnea and left chest pain, the latter, newly developed mass on chest X-ray. They were treated by Lt pneumonectomy with LN dissection and RLL resection with LN dissection The postoperative diagnoses were could be confirmed by NSE study as NEC which were SCNEC and INEC in subgroups. The postoperative courses were uneventful.

• The Korean Journal of Rehabilitation Nursing
• /
• v.19 no.2
• /
• pp.108-117
• /
• 2016

Purpose: This study aimed to prove the effects of the net-step exercise (NSE) on gait ability, depression, cognitive function and activities of daily living (ADL) in older adults. Methods: The study employed a non-equivalent control group non-synchronized design. A total of 64 community-dwelling older adults were recruited and divided equally into two groups; 32 subjects for an experimental group and 32 subjects for a control group. In the experimental group, the NSE was applied to an hour, two times per week for 4 weeks. The level of gait ability, depression, cognitive function and ADL were measured before and after NSE. The study conducted from July to August, 2016. Data were analyzed with descriptive statistics, $x^2$ test, Fisher's exact test, t-test, ANCOVA, and Pearson correlation coefficients using SPSS/WIN 22.0 version. Results: Gait ability, depression, cognitive function were significantly better in the experimental group than the control group. However, the difference in ADL was not significant between the two groups. Conclusion: These findings in this study showed that the NSE was an efficient intervention for older adults. Nurses could apply non-pharmacological interventions to avoid pharmacological side-effects.

• Nuclear Engineering and Technology
• /
• v.54 no.9
• /
• pp.3242-3249
• /
• 2022

As Kori unit 1 is undergoing the decommissioning process, estimating the disposal amount of waste from the decommissioned nuclear reactor has become one of the challenging issues. Since the waste disposal amount estimation depends on the packing of the waste, it is highly desirable to optimize the waste packing plan. In this study, we developed an efficient scheme for packing waste component segments. The scheme consists of 1) preparing three-dimensional models of segments, 2) orienting each segment in such a way to minimize the bounding box volume, and 3) applying hybrid genetic algorithm to pack the segments in the disposal containers. When the packing solution converges in the algorithm, it comes up with the number of containers used and the placement of segments in each container. The scheme was applied to Kori-1 reactor pressure vessel. The required number of containers calculated by the developed scheme was 24 compared to 42 that was the estimation of the prior packing plan, resulting in disposal volume savings by more than 40%. The developed method is flexible for applications to various packing problems with waste segments from different cutting options and different sizes of containers.

• Journal of The Korean Society of Agricultural Engineers
• /
• v.57 no.3
• /
• pp.21-39
• /
• 2015

유역 내부의 수문과정에 대한 관측치를 이용한 모형의 보정은 분산형 수문수질 모형의 적용성을 높이는 방법으로 권장되지만, 관측치가 충분하지 않은 경우가 많아 적용사례가 드문 실정이다. 본 연구는 경지에서 유역의 출구까지 여러 단계의 수문과정을 고려하여 분산형 수문수질모형을 보정하는 방법을 제시하고, 이와 같은 방법으로 보정된 모형의 적용성을 검토하고자 하였다. 이를 위해 본 연구는 SWAT 모형을 이용하여 미국 조지아의 South Atlantic Coastal Plain에 있는 한 농업유역의 수문과정을 모의하였다. 또한, 유사와 영양물질의 구체적인 하천운송과정을 모의하기 위해 SWAT모형의 QUAL2E 모듈을 이용하였다. 모형보정은 유역의 유출량 및 유사와 영양물질의 양 뿐만 아니라 경지에서 관측된 바이오매스, 토양 침식량 및 영양물질 발생량, 수변지역 (riparian buffer)에서 발생하는 유사와 영양물질 감소, 하천운송과정 등을 고려하여 수행되었다. 모형의 보정 및 검증기간은 자료기간과 토양보전농법의 시행기간을 고려하여 선정되었으며, 보정된 모형의 적용성은 복수의 통계치 (NSE, RE, RSR 등)를 이용하여 분석되었다. 보정된 모형은 유역의 출구에서 하천유량과 총질소량을 각각 NSE 0.93 및 0.59의 정확도로 모의하였다. 그러나 유사 (NSE: 0.40)와 총인량 (NSE: 0.45)모의에서는 상대적으로 낮은 정확도를 보였다. SWAT의 QUAL2E 모듈을 이용하여 하천에서의 유사 및 영양물질 운송과정을 고려하는 것은 총인과 총질소 모의결과의 정확도를 향상시킬 수 있는 것으로 나타났다. 본 연구에서 다단계 수문과정을 고려하여 보정된 SWAT모형은 유역 내부에서 발생하는 수문과정을 모의하는데 적용성이 있는 것으로 나타났다. 하지만, 계측방법 및 계측된 자료의 분석방법의 변화에 따른 오차와 토지이용의 시공간적 변화를 모의에서 고려하지 못해서 발생한 오차를 감안하더라도, 보정된 모형은 유역출구에서 관측되는 유사와 영양물질 양을 정확하게 모의하는데 실패 (NSE < 0.5)하였다고 평가할 수 있으며, 이는 SWAT 모형의 보정에서 다단계 또는 유역내부의 수문과정을 고려하는 것이 유역출구에서 높은 모의 정확도를 얻는데 기여하지 못할 수도 있음을 보여주었다.

• Journal of Korean Society of Steel Construction
• /
• v.11 no.3 s.40
• /
• pp.251-258
• /
• 1999

The aim of this paper is to examine the behavior of the N-joints using square hollow sections and to improve the structural performance without reinforcing the joints. The selected parameters are the ratio of web to chord width, gap to chord width and eccentricity to chord width. Comparison between test results and codes shows the fact that the NPE-type has superior structural properties to the NSE-type in ultimate strength and deformation capacity. The experimental formulae based on the regression analysis are proposed. Ultimate strength formula employed in eurocode 3 is revised and proposed for the NSE-type. And ultimate strength formula including the eccentricity to chord width ratio which effects on the ultimate strength is proposed for the NPE-type.

• Journal of The Korean Society of Clinical Toxicology
• /
• v.16 no.1
• /
• pp.49-56
• /
• 2018

Purpose: Glufosinate ammonium poisoning can cause seizures, even after a symptom-free period. This study was conducted to evaluate the relationship between serum neuron specific enolase (NSE) level and the occurrence of seizures in patients with acute glufosinate ammonium poisoning. Methods: For this retrospective observational study, data from patients diagnosed with acute glufosinate ammonium poisoning were collected between January 2016 and June 2016. Serum NSE was measured within 2 hours of arrival at the emergency department. The patients were divided into a seizure group and a non-seizure group. Results: The seizure group included eight of the 15 total patients (53.3%). The serum NSE level was significantly higher in the seizure group than in the non-seizure group ($32.4{\pm}11.9ng/mL$ vs. $19.5{\pm}5ng/mL$, p=0.019). The amount of glufosinate ingested and initial and peak serum ammonia levels were significantly higher in the seizure group than in the non-seizure group. There was no significant difference in the area under the curve of the serum NSE level or the initial and peak serum ammonia levels in terms of predicting the occurrence of seizures. Conclusion: In acute glufosinate poisoning, initial serum NSE levels may help in prediction of seizures.

• Journal of Soil and Groundwater Environment
• /
• v.26 no.6
• /
• pp.118-129
• /
• 2021

The sediment transportation caused by soil erosion due to rainfall-discharge in the large watershed scale plays critical role in human society. The relationship between rainfall-discharge-sediment transportation is depending on the start time of rainfall and end of rainfall but, the studies related with rainfall characteristics are insufficient. In this study, The Soil and Water Assession Tool (SWAT) model was used to study the relationship between rainfall-discharge-sediment transportation at the Sook river watershed which is monitored by the Ministry of Environment. To do this, first of all, the sensitivity analysis about model attributes was performed using monitored data. The accuracy analysis of SWAT model was conducted using the model's efficiency index (Nash and Sutcliffe model efficiency; NSE) and the coefficient of determination (R²). After that, it was studied what results could be obtained according to changes in rainfall timing and end points. In the result of discharge simulation, the modified rainfall values (sum of total rainfall starting time and end time) showed more high accuracy values (R²:0.90, NSE: 0.8) than original rainfall values (R²:0.76, NSE: 0.72). In the result of sediment transportation simulation, during calibration had more resonable results(R²:0.87, NSE: 0.86) than compared with original rainfall values (R²:0.44, NSE: 0.41). However, validation results of sediment transportation simulation showed low accuracy values compared with calibration results. This results maybe cause monitoring periods of sediment flow compared with discharge monitoring periods. Nevertheless, since rainfall characteristic plays critical rule in model results, continuous research on rainfall characteristic is needed.

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