• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제49권7호
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• pp.412-417
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• 2000

This paper offer fundamental materials about Partial Discharge(PD) detection by electromagnetic waves. All spectrum data-usually used as grape- can be used as numbers. And then the average of background noise spectrum strength was made. Average value subtract from every data. Then average value appeared, graphed. The graph was compared with the magnitude of charge. The shape of changes is similar, and the change of electric field strength could be seen in one sight. When the magnitude of charge is over than 100[pC], antenna can detect partial discharge. So this method will be very useful to diagnosis of insulation. It the performance of the antenna used in this experiment is analyzed, good results can be obtained.

• 한국수자원학회논문집
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• 제38권6호
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• pp.485-494
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• 2005

유량과 수질의 관계를 분석하는 것은 매우 중요하다. 하천의 실시간적 관리를 위해서는 유량과 수질의 측정이 동일한 지점에서 동시간적으로 이루어져야 보다 효과적이다. 그러나 수질자동측정망 지점과 T/M 수위관측소가 원거리에 위치한 경우들이 있으며, 평창강 수질자동측정망 지점이 그 중 하나이다. 이러한 지점에서는 보다 정확한 유량 산정과 이를 활용한 예측 프로그램이나 시스템이 요구된다. 이번 연구에서는 미계측 지점인 평창강 수질자동측정망 지점에 유량예측 신경망 모형을 적용하고, 적용성을 검토하기 위해 WMS 모형의 모의결과와 비교하였다. WMS 모형은 첨두유량이 작고, 수문곡선이 단조로운 사상에 적합한 것으로 나타났다. 신경망 모형의 유출량 예측값은 비유량과 WMS 모형의 모의값에 근사하였으며, 미계측 지점에서의 유출량 변화성향을 잘 반영하는 것으로 나타났다.

• 한국물환경학회지
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• 제27권3호
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• pp.293-299
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• 2011

The quantity of a discharge load can change with changes in rainfall in the area with a combined sewer system (CSS). To evaluate the implementation appropriately in the management of total maximum daily loads (TMDLs), the effects of rainfall changes should be considered in the estimation of the discharge load. The rainfall condition for the estimation of the discharge load in a certain year should be standardized to the same rainfall condition as that of the reference year. However, the calculation process is very complicated with its potential limitations. This study investigated and developed relatively simple methods for estimating the discharge load. Load conversion method (LCM) is designed to convert the discharge load under the current rainfall condition into that of the reference rainfall conditions. Simple rainfall data method (SRDM) is to simplify the estimation process of the discharge load by the simple conversion of rainfall data. These methods were applied to calculate the discharge load and examine the estimation results. From the results of this study the application of these methods may be useful for estimating the discharge load in the TMDL process.

• 해양환경안전학회지
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• 제26권3호
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• pp.242-253
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• 2020

This study examined the ef ects of freshwater discharge by artificial dikes from the Kanwol and Bunam lakes on the dynamics in the Chunsu Bay, Yellow Sea, Korea, during the summer season based on three-dimensional numerical modeling experiments. Model performances were evaluated in terms of skill scores for tidal elevation, velocity, temperature, and salinity and these scores mostly exceeded 90 %. The variability in residual currents before and after the freshwater discharge was examined. The large amount of lake water discharge through artificial dikes may result in a dramatically changed density field in the Chunsu Bay, leading to an estuarine circulation system. The density-driven current formed as a result of the freshwater inflow through the artificial dikes (Kanwol/Bunam) caused a partial change in the tidal circulation and a change in the scale and location of paired residual eddies. The stratification formed by strengthened static stability following the freshwater discharge led to a dramatic increase in the Richardson number and lasted for a few weeks. The strong stratification suppressed the vertical flux and inhibited surface aerated water mixing with bottom water. This phenomenon would have direct and indirect impacts on the marine environment such as hypoxia/anoxia formation at the bottom.

• Fisheries and Aquatic Sciences
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• 제13권2호
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• pp.89-95
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• 2010

This study was conducted to investigate the efficacy of using a coating of gelatin extracted from refiner discharge to extend the shelf life of salmon during cold storage ($5^{\circ}C$). Relative percentage of moisture loss in gelatin-coated salmon during cold storage was less than that of uncoated salmon. The treatment of salmon with gelatin reduced volatile basic nitrogen (VBN) formation throughout the entire storage period. Measurements of the peroxide value (POV), fatty acid composition, and (20:5n-3+22:6n-3)/16:0 ratio during cold storage indicated that the coating of salmon with gelatin from refiner discharge effectively suppressed lipid oxidation over the entire storage period. The extent of sensory color change during cold storage was less in the gelatin-coated than in the uncoated salmon. From the results of chemical measurements, such as relative moisture content, VBN, POV, fatty acid composition, (20:5n-3+22:6n-3)/16:0 ratio, and sensory color change, the conclusion was made that the coating treatment of salmon with refiner discharge gelatin effectively suppressed moisture loss, lipid oxidation, and color deterioration over the entire storage period.

• 한국수자원학회논문집
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• 제49권7호
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• pp.615-623
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• 2016

본 연구에서는 개량형 공압식 가동보를 대상으로 가동보의 기립 각도변화에 따른 잠김흐름 특성을 분석하고 유량계수를 산정하였다. 실험결과, 위어마루에서 하류수면까지의 높이와 위어마루에서 상류 수면고 높이의 비($h_t/H$)에 대한 유량감소계수($Q_s/Q_1$)의 변화는 ($h_t/H$가 1에 가까울수록 감소하였다. 따라서 보 하류에서의 수심은 상류보다 작지만 보를 통과하는 흐름으로 인해 하류 유속이 빠르게 나타났으며, 유량이 증가할수록 상 하류 수위차는 감소하는 것으로 나타났다. 또한 같은 유량조건인 경우 하류수두는 L/W가 클수록 크게 증가하였다. 개량형 공압식 가동보의 잠김흐름 유량계수는 가동보의 물리적 제원보다는 상류 접근흐름수두와 상 하류 흐름조건에 의하여 결정되었다.

• 접착 및 계면
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• 제17권3호
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• pp.104-109
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• 2016

AC 코로나와 DC 코로나 처리 효과들을 비교하기 위해 선행연구의 DC 코로나 처리 조건들과 같이 폴리에스테르 직물들을 전류세기 5, 10, 15 A로, 공급속도 5, 10, 15 m/min로 AC 코로나 처리하였다. 이들의 표면변화를 주사전자현미경(SEM)과 X-ray 광전자분석기(XPS)로 확인하였고, 또한 물리적 성질의 변화를 건조 시와 습윤 시의 접착강도를 통하여 측정하였다. 대기압에서 AC 코로나 방전처리에 의해 폴리에스테르 직물의 표면변화는 DC 코로나 방전과 유사한 경향을 보였다. 일반적으로 AC, DC 코로나 처리 양쪽에서 건조 시의 접착강도는 전류세기와 공급속도가 증가할수록 증가하였으나, 습윤 시의 접착강도는 전류세기가 증가할수록 공급속도가 감소할수록 증가하였다. 전류가 20 A일 때 DC 코로나 방전에서는 탄화가 발생하였으나 AC 코로나에서는 탄화가 발생하지 않았다.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2019년도 학술발표회
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• pp.152-152
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• 2019

This study demonstrates a novel approach of remotely sensed estimates of stream flow at fifteen hydrological station in the Han River Basin, Korea. Multi-temporal data of the European Space Agency's Sentinel-1 SAR satellite from 19 January, 2015 to 25 August, 2018 is used to develop and validate the flow estimation model for each station. The flow estimation model is based on a power law relationship established between the remotely sensed surface area of water at a selected reach of the stream and the observed discharge. The satellite images were pre-processed for thermal noise, radiometric, speckle and terrain correction. The difference in SAR image brightness caused by the differences in SAR satellite look angle and atmospheric condition are corrected using the histogram matching technique. Selective area filtering is applied to identify the extent of the selected stream reach where the change in water surface area is highly sensitive to the change in stream discharge. Following this, an iterative procedure called the Optimum Threshold Classification Algorithm (OTC) is applied to the multi-temporal selective areas to extract a series of water surface areas. It is observed that the extracted water surface area and the stream discharge are related by the power law equation. A strong correlation coefficient ranging from 0.68 to 0.98 (mean=0.89) was observed for thirteen hydrological stations, while at two stations the relationship was highly affected by the hydraulic structures such as dam. It is further identified that the availability of remotely sensed data for a range of discharge conditions and the geometric properties of the selected stream reach such as the stream width and side slope influence the accuracy of the flow estimation model.

• 대한한방내과학회지
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• 제40권5호
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• pp.938-947
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• 2019

Objective: This study was performed to report the changes in symptoms and radiological consequences of a patient diagnosed with spinal neurofibroma and complaining of lower back pain. Methods: The patient was diagnosed with a spinal neurofibroma after MRI examination and was treated with traditional Korean medicine, including traditional Korean medication and acupuncture. We measured the change in symptom severity using a numerical rating scale (NRS) and the Oswestry Disability Index (ODI). We also used the EQ-5D (EuroQoL-5D) scale to assess the patient's quality of life. In addition, we examined the change in the size of the cyst by MRI twice after discharge: at about 3 months after discharge and at about 8 months after discharge. Results: After about 6 weeks of treatment, most pathological symptoms had decreased. The patient showed a decline in NRS and ODI scores and showed an increase in quality of life. The two MRI examinations after the discharge revealed a decrease in the size of the cyst. Conclusions: Traditional Korean medicine can be a solution for patients with spinal neurofibroma causing neurological pain.

• 한국수자원학회논문집
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• 제56권1호
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• pp.23-34
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• 2023

본 연구에서는 실내실험과 수치모의를 통해 식생대에서의 소류사 이동 및 하도 변화를 분석하였다. 실내시험에서 식생대의 영향을 검토하기 위해 아크릴 봉으로 제작한 인공 식생대를 실험수로에 설치하였으며, 유량 조건을 조정하여 유량변화에 따른 식생대에서의 소류사 이동 및 하도 변화를 검토하였다. 다음으로 실내실험과 동일한 조건을 2차원 수치 모형인 Nays2D모형에 적용하여 수치모의를 수행하고, 그 결과를 실내실험 결과와 비교하여 수치모형의 적용성을 검토하였다. 마지막으로 적용성을 검토한 수치모형을 적용하여 식생밀도의 변화에 따른 소류사 이동 및 하도의 변화를 검토하였다. 실내실험과 수치모형을 적용하여 유량변화에 따른 식생대에서의 소류사 이동 및 하도 변화를 검토한 결과, 두 적용 방법의 결과가 유사하게 나타났다. 유량이 증가함에 따라 상류에서 유입된 소류사가 식생대 내부에 퇴적되었으며, 식생대 반대편에는 흐름이 집중되어 침식이 발생하였다. 또한 시간이 지날수록 하류방향으로 침식범위가 증가하였다. 식생밀도의 변화에 따른 소류사 이동 및 하도의 변화를 검토한 결과, 식생대의 식생밀도가 증가할수록 상류에서 유입된 소류사가 식생대 내부에 퇴적되었다. 또한 식생밀도의 증가로 인하여 흐름이 식생대의 반대편으로 집중되어 식생대 반대편 하도의 침식이 발생하였다.