• 한국신재생에너지학회:학술대회논문집
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• 2011.05a
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• pp.61.1-61.1
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• 2011

풍력 터빈은 복잡한 바람 조건에 노출되어 운용 되는 시스템으로서 경제성과 신뢰성을 확보하기 위해서는 이러한 조건하에서 시스템에 작용하는 정확한 공력 하중 예측이 필요하다. 여러 조건 중에서도 요에러는 풍향이 수시로 바뀌기 때문에 피할 수 없는 비정상 유동 중에 하나이다. 본 연구에서는 이러한 요에러 발생시 공력 하중예측을 적절히 예측하기 위해서 와류 격자 기법을 기반으로 하는 비선형 와류 보정기법을 적용하였다. 비선형 와류 보정기법은 실속 이후의 공력 예측을 위해 기지의 공력 테이블을 이용하는 방법으로서 실속 이후의 공력 테이블 값의 양력과 와류 격자 기법에서의 양력 값이 일치하도록 순환(circulation)을 분포시키는 기법이다. 또한 요에러시에 발생할 수 있는 동적 실속을 계산하기 위해 Beddoes-Leishmen 동적 실속 모델을 비선형 와류 보정 기법에 적용하는 연구를 수행하였다. 요에러시 공력 하중 예측에 관한 수치해석 기법 연구의 적절성을 알아보기 위해 NREL-Phase VI Rotor 실험 결과와 비교 하였다. 그 결과 기존의 여타의 기법들과 비교하여 본 연구에서 제안한 기법의 적절성을 확인 할 수 있었다. 앞으로 본 연구를 바탕으로 다양한 비정상 공력 조건에 대한 풍력 블레이드의 공력 하중 해석에 대해 수행할 계획이다.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.21 no.5
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• pp.95-102
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• 2021

The urinalysis, which is universally accessible to the general public, has disadvantages of being less objective using sight and purchasing a separate portable urinalysis machine. However, due to the high penetration rate and performance improvement of smartphone created by the development of mobile communication technology, research on urinalysis services using smartphone has been conducted. In this paper, a new urinalysis screening application based on smartphone was developed by supplementing the limitations of the previously studied urinalysis services. The key technology of the application is urinalysis recognition algorithm and urinalysis pad color determination algorithm through image-processing and contour detection. In order to confirm the performance of the developed application, urinalysis strip was photographed and analyzed from various backgrounds and angles.

• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.459-459
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• 2022

물수지의 불균형으로 발생되는 가뭄은 장기간에 걸쳐 넓은 규모로 발생되는 자연재해로서, 농업 및 산업에 직접 피해와 다양한 상품에 대한 공급 부족으로 인한 가격 상승 등의 간접 피해를 야기하는 재해이다. 이러한 가뭄을 정량적으로 평가하기 위하여 기상 요인(강수, 기온), 농업 요인(식생), 수문 요인(증발산, 토양수분) 등과 같은 설명 변수를 기초로 하는 많은 가뭄지수들이 개발되어 왔다. 대표적인 가뭄지수에는 Standardized Precipitation Index (SPI), Standardized Precipitation Evapotranspiration Index (SPEI), Palmer Drought Severity Index (PDSI), Soil Water Deficit Index (SWDI), Vegetation condition index (VCI), Temperature Condition Index (TCI), Vegetation Health Index (VHI), Scaled Drought Condition Index (SDCI), Integrated Crop Drought Index (ICDI) 등이 있다. 본 연구는 최근 개발된 통합작물가뭄지수(ICDI)를 통해 미국 옥수수의 약 90%를 생산하는 농업지역인 미국 콘벨트의 가뭄 특성을 분석하고자 한다. ICDI는 기상 요인(강우량 및 지표면 온도), 수문학적 요인(잠재 증발산 및 토양수분), 식생 요인(강화식생지수(Enhanced Vegetation Index, EVI))의 조합을 통해 지표면의 건조·습윤 상태 및 식생의 건강 상태를 설명하는 가뭄지수이다. 2004년부터 2019년까지 주요 콘벨트 지역인 일리노이, 인디애나, 아이오와를 대상으로 가뭄분석을 실시하였으며, 옥수수 수확량 아노말리와의 상관성을 분석하였다.

• Clinical and Experimental Pediatrics
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• v.50 no.5
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• pp.457-461
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• 2007

Purpose : Urinary tract infection (UTI) is a common bacterial infectious disease in childhood. Especially UTI in infant and young children is associated with urinary tract anomalies such as hydronephrosis, vesicoureteral reflux. The aim of this study was to compare the clinical and laboratory characteristics, and uroradiologic findings of UTI caused by pathogens other than E. coli with UTI caused by E. coli in infant and young children. Methods : We retrospectively reviewed medical records of 170 infants and children, who had been admitted for UTI to Il Sin Christian Hospital from January 2003 to December 2005. All patients were divided into two groups; E. coli and non-E. coli UTI, and they were compared for demographic data, clinical data (degree and duration of fever, time to defervescence, and length of hospital stay), underlying urinary tract anomalies (by history and ultrasonography), recurrent infection (by history and past medical records), and laboratory data [urinalysis, white blood cells (WBC) count in peripheral blood, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and serum creatinine level]. Results : Of the 170 UTI patients, the number of non-E. coli UTI was 114 (67.1%) and E. coli UTI was 56 (32.9%). As compared to E. coli group, non-E. coli group was younger in age ($0.52{\pm}0.59years$ vs $0.84{\pm}1.39years$, P<0.05), had higher rates of urinary tract anomalies [n=46 (82.1%) vs n=53 (46.5%), P<0.001], higher recurrence rate, shorter time to defervescence, less peripheral blood WBC count, lower level of CRP, lower level of ESR. Conclusion : The characteristics of non-E. coli UTI compared to E. coli UTI was younger age, milder clinical symptoms and signs, higher rates of urinary tract anomalies and higher recurrence rate.

• Science of Emotion and Sensibility
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• v.22 no.3
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• pp.47-54
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• 2019

We examined previous studies of the correlation analysis of heart rate variability as a method to reduce the stress caused by outside noise during driving, and we investigated whether there are electrocardiographic changes when drivers play music, which provides a stable sound source amid the noise. Because the number of cars increases every year, drivers and passengers show an increase in stress caused by outside noise. The stress from outside noise while a person is driving can cause several disorders, such as anxiety, immunosuppression, depression, and heart disease. Subjects in this study operated a vehicle simulator to reduce the stress from outside noise and were given different auditory stimuli, and we studied the drivers' responses to the stimuli. Repeated-measures analysis of variance revealed a significant differences between subjects exposed to different auditory stimuli (ρ < 0.05). Through post hoc analyses, we examined these differences. We found significant differences between factor 1 (stability) and factor 2 (simulation driving), between factor 1 (stability) and factor 3 (driving + police siren), and between factor 1 (stability) and factor 4 (driving + police siren + music). In addition, the factor that produced the highest level of sympathetic nervous system activity was factor 4 (driving + police siren + music), followed by factor 3 (driving + police siren), factor 2 (driving), and factor 1 (stability). In conclusion, even when a police siren was heard during driving, there were no significant differences on electrocardiograms (ECGs). In addition, even when the siren was heard over the music, there was no difference on the ECGs (ρ < 0.01). In future studies, investigators should determine which types of music help stabilize the heart rate during driving.

• Journal of Korea Port Economic Association
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• v.31 no.1
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• pp.51-68
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• 2015

Recently, it has been emphasized that 'marine special economic zone' need to be designated and developed. Therefore, the purpose of this paper is to analyse on successful growth factors of 'marine special economic zone'. This study deals with the terms of three connection success factors which are a firm's subjective factors, a industrial environment factors, and a governmental policy factors. According to analysis results of the three successful growth factors, a firm's subjective factors(4.11 score) are scored at the most ones of the three successful growth factors, to be compared with a industrial environment factors(3.89 score). with a government policy factors(3.72 score). Therefore, first of all, it is important to enhance competitiveness of 'marine special economic zone' through as follows, a firm's subjective factors : (1) to procure concentrated market strategy and real market capacity, (2) to promote customer service, (3) to procure speedy satisfaction of customer needs and confidence, (4) to enhance competitiveness through standing in a trio of connection growth model. And, the next, we have to enhance competitiveness of 'marine special economic zone' through considering a industrial environment factors, that is, sustainable growth of marine industry, clustering of marine industry, expansion of infrastructure, etc., and a government policy factors, that is, leading law improvement and policy of leading 'marine special economic zone' designation and development, etc.,

• Korean Journal of Clinical Laboratory Science
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• v.49 no.4
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• pp.366-373
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• 2017

Urinalysis is considered to be easier and simpler than other tests. It has been known to cause no burden to patients, while offering important information on diagnosing, treating, and determining the prognoses of kidney and urinary tract diseases. Urinary sediments are usually performed by microscopic examination of centrifuged urine by technologist. The guidelines proposed by the Korean Association of External Quality Assessment Service are actually different from those actually practiced by medical institutions and taught to biomedical students in textbooks. Therefore, we verified whether different sediment preparation methods lead different test results. Specimens that tested positive from the occult blood and leukocyte esterase in the urine dipstick test were randomly selected for a microscopic examination. The differences in the urine sediment preparation affected the sediment concentrations, which influenced the cell grade and cell number per HPF. The first factor in determining the sediment concentration is the centrifugal force. Many medical institutions use 1,500 rpm as the centrifugal speed without considering the radius of the centrifuge; such a value may not be accurate for 400 G. Consequently, there were differences in urine concentrations, which influenced the results. The second factor is the amount of sediment in urine. Different amounts of the remaining supernatant led to different sediment concentration factors, again, causing different results. Furthermore, not only by using a pipette to obtain an accurate amount as stipulated, but also by roughly obtaining a drop, the microscopic examination using such a volume of sediment examined affected the results. Therefore, this study highlights the importance of standardization of urine sediment preparation procedures to promote consistency and accuracy across institutions.

• Childhood Kidney Diseases
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• v.12 no.2
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• pp.150-156
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• 2008

Purpose : Many results have reported a correlation between the spot urine protein/creatinine ratio(P/C ratio) and 24-hour urinary protein(24UP) amount. This study was designed to evaluated correlation between 24UP amounts and P/C ratio in children and to find the factors that affect this correlation. Methods : 210 patients who visited the Department of Pediatrics in Busan Paik Hospital from september 2003 to december 2007 were included in this study. All the patients were divided into I, II, III/A, B, C group[I:24UP(mg/$m^2$/day)]<100, II: 100$\leq$24UP<1,000, III: 24UP$\geq$1,000, A: Cr excretion(mg/kg)<15, B: 15$\leq$Cr excretion<25, C: Cr excretion$\geq$25)]. Pearson correlation analysis was performed between 24UP and P/C ratio to evaluate the relationship. We defined fractional difference between 24UP and P/C ratio, and then performed multiple regression analysis. Results : There was a strong positive linear correlation between 24UP and P/C ratio in all patients, and the correlation was also good in each group. The factors affecting accurate quantitation of proteinuria using spot urine P/C ratio was creatinine excretion. Conclusion : Spot urine P/C ratio is a useful test to predict proteinuria roughly. Therefore, we expect that urine P/C ratio can be used as parameter instead of 24UP, if we set cutoff value of P/C ratio considered to creatinine excretion according to age and sex in large pediatric population.

• Journal of Biomedical Engineering Research
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• v.19 no.5
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• pp.477-486
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• 1998

In this paper, we implemented the urine analysis system capable of measuring a qualitative and semi-quantitative and assay using strip. The analysis algorithm of urine analysis was adopted a fuzzy logic-based classifiers that was robust to external error factors such as temperature and electric power noises. The spectroscopic properties of 9 pads In a strip were studied to developing the urine analysis system was designed for robustnesss and stability. The urine analysis system was consisted of hardware and software. The hardware of the urine analysis system was based on one-chip microprocessor, and Its peripherals which composed of optic modulo, tray control, preamplifier, communication with PC, thermal printer and operating status indicator. The software of the urine analysis system was composed of system program and classification program. The system program did duty fort system control, data acquisition and data analysis. The classification program was composed of fuzzy inference engine and membership function generator. The membership function generator made triangular membership functions by statical method for quality control. Resulted data was transferred through serial cable to PC. The transferred data was arranged and saved be data acquisition program coded by C+ + language. The precision of urine analysis system and the stability of fuzzy classifier were evaluated by testing the standard urine samples. Experimental results showed a good stability states and a exact classification.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.7
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• pp.1319-1325
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• 2006

Urine analysis is basic test in clinical medicine using visual examination by expert nurse. Recently, this test is measured by automatic urine analysis system. But, this system has different results by each instrument. So, a new classification algorithm is required for accurate classify and urine color collection. In this paper, a intelligent color classifier of urine analysis system was designed using neural network algorithm. The input parameters are three stimulus(RGB) after preprocessing using normalization. The fuzzy inference and neural network ware constructed for classify class according to 9 urine test items and $3{\sim}7$ classes. The experiment material to be used a standard sample of medicine. The possibility to adapt classifier designed for urine analysis system was verified as classifying measured standard samples and observing classified result. Of many test items, experimental results showed a satisfactory agreement with test results of reference system.