• 한국수자원학회논문집
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• 제57권7호
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• pp.461-470
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• 2024

본 연구는 다양한 인간의 활동으로 인해 공공수역에 영양물질이 유입됨에 따라 발생하는 부영양화를 초기에 대응하기 위해 T-P (Total Phosphorus) 예측을 진행하였다. 기존의 T-P 모니터링 시스템은 인력 및 시간이 많이 소요되는 단점이 존재해 직독식 센서를 활용한 측정이 국내외를 막론하고 많이 시도되고 있는 추세이다. 따라서 직독식 센서를 통해 얻을 수 있는 수질항목을 활용하여 T-P 예측을 진행하였으며, 두 단계로 나누어 진행하였다. T-P 예측에 있어 Turbidity (Tur)의 중요성에 대해 살펴보았으며, 자동수질분석기 분석항목을 추가한 분석을 통해 직독식 센서 측정 항목만으로 T-P 예측이 가능한지 살펴보았다. 본 연구의 연구 대상 지점인 낙동강 유역 내 T-P 현황을 살펴본 결과, T-P 농도가 상류 지역 대비 중·하류 지역에 높게 나타났다. Pearson 상관분석을 통해 지점별로 T-P와 상관성이 높은 수질항목을 파악하였으며, 이를 활용하여 다중선형회귀분석을 진행하여 T-P를 예측하였다. Tur의 유무에 따른 분석을 진행하였으며, 자동수질분석기 분석항목이 포함된 분석을 통해 직독식 센서 측정 항목과의 성능을 비교하였다. 결과적으로 Tur 활용의 중요성을 확인하였으며, 이는 부영양화 개선 대책 수립을 위한 보조 자료로 활용할 수 있을 것으로 판단된다.

• 동아시아식생활학회지
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• 제18권4호
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• pp.489-498
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• 2008

This study was designed to evaluate the relationships among snack intake, obesity index, and blood parameters in obese elementary school children. Anthropometric measurements, nutrient intake from meals and snacks, serum cholesterol, glucose, GOT, GPT, and hemoglobin levels were obtained 36 obese elementary students (boys=28, girls=8). The average age, height, weight, % body fat, and obesity index were 11.9 years, 145.5cm, 53.5kg, 45.7%, and 32.4%, respectively. The mean energy intake was 1,818.7 kcal in boys and 1,818.1 kcal in girls. In addition, the energy intake from snacks was 470.4 kcal in boys and 479.4 kcal in girls. The levels of plant fat (p<0.05) and cholesterol (p<0.001) consumed during snacks (1,000 kcal per energy intake) were higher than those consumed during meals. The serum cholesterol, glucose, and hemoglobin levels were 177.4 mg/dL, 90.4 mg/dL, and 14.5 g/dL, respectively. In addition, the levels of serum GOT (p<0.001) and GPT (p<0.05) were higher in boys than in girls. Height was positively correlated with food intake (p<0.05), snack intake (p<0.05), and energy intake from snacks (p<0.05). Based on these results, further studies are needed in order to investigate the relationships among various aspects of snacking and obesity in elementary school children.

• Smart Structures and Systems
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• 제25권2호
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• pp.135-153
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• 2020

There has been a sustained interest towards the non-contact structural displacement measurement by means of videogrammetric technique. On the way forward, one of the major concerns is the spurious image drift induced by temperature variation. This study therefore carries out an investigation into the temperature effect of videogrammetric technique, focusing on the exploration of the mechanism behind the temperature effect and the elimination of the temperature-caused measurement error. 2D videogrammetric measurement tests under monotonic or cyclic temperature variation are first performed. Features of measurement error and the casual relationship between temperature variation and measurement error are then studied. The variation of the temperature of digital camera is identified as the main cause of measurement error. An excellent linear relationship between them is revealed. After that, camera parameters are extracted from the mapping between world coordinates and pixels coordinates of the calibration targets. The coordinates of principle point and focal lengths show variations well correlated with temperature variation. The measurement error is thought to be an outcome mainly attributed to the variation of the coordinates of principle point. An approach for eliminating temperature-caused measurement error is finally proposed. Correlation models between camera parameters and temperature are formulated. Thereby, camera parameters under different temperature conditions can be predicted and the camera projective matrix can be updated accordingly. By reconstructing the world coordinates with the updated camera projective matrix, the temperature-caused measurement error is eliminated. A satisfactory performance has been achieved by the proposed approach in eliminating the temperature-caused measurement error.

• 한국항공우주학회지
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• 제41권7호
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• pp.524-531
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• 2013

본 연구에서는 헬리콥터 로터 블레이드의 제작 과정 및 여러 가지 요인으로 인해 발생하는 불균형성을 해소하기 위한 RTB(Rotor Track and Balance) 알고리즘을 개발하였다. 비행 시험 결과로부터 RTB 조절 값과 트랙 및 기체 진동 사이의 상호관계를 선형모델을 이용한 회귀분석을 통하여 RTB 모델을 구축하였다. 개발된 RTB 알고리즘을 실기 시험 결과에 적용하여 RTB 모델을 검증하였고 선형화 모델만으로도 비교적 정확한 모델링이 가능함을 확인하였다. RTB 조절값 설정을 위해 최적화 문제를 정식화하고 유전자 알고리즘에 입자 군집 최적화(PSO) 알고리즘을 결합하여 빠른 수렴성을 갖는 최신의 최적화 기법을 적용하였다. 또한 최적화 해석을 통하여 얻은 RTB 조절값을 이용하여 트랙 편차와 기체 진동을 허용 기준치 아래로 감소시키고, 다양한 비행 조건에 대하여 효율적인 RTB를 수행할 수 있음을 보였다.

• 대한임상검사과학회지
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• 제48권3호
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• pp.196-201
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• 2016

효과적인 비만의 중재는 대상 인구에서 가장 관련성이 있는 인구통계학적 건강 관련 및 직무 관련 요인을 고려해야 한다. 가장 강력한 비만 관련 요인은 직업군 또는 연령 범주에서 다룰 수 있다. 이 연구의 목적은 심리적인 직무 스트레스와 면역관련 인자의 혈액분석의 상관성에 대한 최신지견을 제공하는 것이다. 우리는 여성 근로자의 비만 관련 매개 변수 뿐만 아니라 자연살해세포활성(NKCA)을 평가하였다. 비만과 관련된 혈당(p<0.05)은 연령에서 유의한 차이를 보였다. 또한, 비만군과 non-비만군에서는 NK 세포의 활성에 큰 차이를 보였다(p<0.05). 단계적 다중 회귀 분석에서 NKCA는 비만 관련 요인과 밀접한 상관성을 보였다. 향후에는 면역인자들의 활성도가 증가하는 생물학적 변화를 연구해야 할 것이다.

• 한국산업보건학회지
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• 제17권1호
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• pp.31-42
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• 2007

Recently, concerns regarding indoor air quality in offices have continued to increase. Thirty offices in five metropolitan commercial buildings were surveyed from February to April 2004. Sampling was performed during normal business hours. Thermal comfort factors such as temperature and relative humidity, carbon dioxide ($CO_2$), carbon monoxide (CO), formaldehyde (HCHO), respirable dust, $PM_{10}$ were sampled and analyzed to determine the mean, standard deviation, range, and correlation for each of those parameters. The data was then compared to office as standard of Ministry of Labor, and guideline applicable to the indoor environment. The results represented that the temperature was slightly higher than the standard of American Society of Refrigerating and Air-Conditioning Engineers (ASHRAE), the relative humidity was lower that the standard of ASHRAE. The range of the 8-TWA concentration of $CO_2$ was 639 ~ 786 ppm, but 33.3% of the total thirty offices exceeded the 1000 ppm as ceiling concentration. The concentration of CO was less than 3 ppm, which was similar to that of offices in Japanese. The mean concentration of formaldehyde was 0.032 ppm, and only 2 % of total samples (193) exceeded the 0.1 ppm, standard of formaldehyde in office air. The concentration of respirable dust and $PM_{10}$ was not exceeded the standard of those parameters, $150{\mu}g/m^3$. The concentration of those parameters in the office air was statistically correlated.

• 한국물환경학회지
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• 제29권4호
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• pp.504-513
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• 2013

Water quality trends for major tributaries (66 sites) in the Yeongsan River basin of Korea were examined for 12 parameters based on water quality data collected every month over a period of 12 months. The complex data matrix was treated with multivariate analysis such as PCA, FA and CA. PCA/FA identified four factors, which are responsible for the structure explaining 78.2% of the total variance. The first factor accounting 27.3% of the total variance was correlated with BOD, TN, TP, and TOC, and weighting values were allowed to these parameters for grade classification. CA rendered a dendrogram, where monitoring sites were grouped into 5 clusters. Cluster 2 corresponds to high pollution from domestic wastewater, wastewater treatment and run-off from livestock farms. For grade classification of tributaries, scores to 10 indexes were calculated considering the weighting values to 3 parameters as BOD, TN and TP which were categorized as the first factor after FA. The highest-polluted group included 10 tributaries such as Gwangjucheon, Jangsucheon, Daejeoncheon, Gamjungcheon, Yeongsancheon. The results indicate that grade classification method suggested in this study is useful in reliable classification of tributaries in the study area.

• 한국측량학회지
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• 제32권1호
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• pp.9-17
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• 2014

대기의 에너지를 측정하거나 지표면유출을 예측하는 기상 및 수문모델에서 지표면특성(식생피복)을 파악하는 것은 매우 중요한 요소이다. 1978년 Deardorff가 식생피복을 정량적으로 파악하기 위하여 식생피복지수(Vegetation Cover Fraction)를 제안한 후 식생피복지수에 관한 연구가 활발해졌다. 그러나 선행연구에서는 AVHRR, MODIS 그리고 KOMPSAT-2영상과 같은 고 저해상도 위성영상을 이용한 많은 연구가 있었으나, 중해상도 영상인 Landsat에 대한 연구는 미비한 실정이다. 따라서 본 연구는 Landsat OLI영상을 이용하여 식생피복지수 산정방법을 연구하였다. 정확하고 효율적인 식생피복지수 산정방법을 연구하기 위하여, 본 연구에서 제안된 방법과 선행연구방법을 비교평가 하였다. 실험결과 NDVI와 식생피복지수는 많은 연관성을 지니는 것으로 분석되었으며, 본 연구에서 제안된 방법을 이용한 식생피복지수가 특이점을 제외한 RMSE 7.3%로 전체 방법 중에서 가장 높은 정확도를 보였다.

• Asian-Australasian Journal of Animal Sciences
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• 제19권5호
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• pp.611-616
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• 2006

Genetic parameters for performance traits on 409 bulls and growth and carcass traits on 591 of their steer progeny were estimated in Japanese Black cattle with Gibbs sampling. Traits of bulls included body weight at the start (BWS) and finish (BWF) of test, daily gain (DG), concentrate, roughage and TDN intake, and TDN conversion ratio. Progeny traits were BWS, BWF, DG, rib eye area, marbling score (MSR), dressing percentage and subcutaneous fat thickness (SFT). In bulls, heritabilities were high for BWS (0.50) and BWF (0.63) and moderate for concentrate (0.48) and TDN intake (0.45), while in progeny, the heritability for all the studied traits was moderate to high (ranging from 0.30 to 0.73), highlighting the potential for genetic improvement of these traits. Genetic correlations between TDN intake and growth traits (BWS, BWF and DG) in bulls were highly positive (ranging from 0.77 to 0.94). The weak but negative genetic correlation (-0.20) between MSR and SFT in progeny indicated that improvement of beef marbling without increasing subcutaneous fat deposition could be possible. The estimated genetic correlations of roughage intake of bulls with body weights (BWS and BWF) and MSR of their progeny were moderate (ranging from 0.35 to 0.52). On the basis of the selection for bulls, growth traits and TDN intake correlated positively with SFT (ranging from 0.43 to 0.53) of their progeny, suggesting the necessity of controlling the increase of SFT in selection programs.

• 한국대기환경학회지
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• 제29권6호
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• pp.780-788
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• 2013

This study attempted to determine important meteorological parameters related to airborne pollen concentrations in urban areas. Hourly pollen measurement data were prepared from a regular sampling with a volumetric Burkard spore trap at a site in the Ulsan city, during the spring season (March~May) of 2011. Results showed that the daily mean and maximum concentrations for total pollen counts during the spring season were statistically significantly correlated with both air temperature and wind speed; daily mean pollen concentration was the most highly related to daily maximum temperature (r=0.567, p<0.001). It was also identified that pollen concentration has a stronger relationship with wind speed at the rural site than at the urban one, which confirms that strong wind conditions over the pollen sources area can be favorable for pollen dispersal, resulting in increases in airborne pollen concentrations downwind. From the results of an oak-pollen episode analysis, it was found that there was a significant relationship between hourly variation of oak pollen concentrations and dynamic meteorological factors, such as wind and mixing height (representing the boundary layer depth); especially, a strong southwestern wind and elevated mixing height was associated with high nocturnal concentrations of oak pollen. This study suggests that temperature, wind, and mixing height can be important considerations in explaining the pollen concentration variations. Additional examination of complex interactions of multiple meteorological parameters affecting pollen behavior should be carried out in order to better understand and predict the temporal and spatial pollen distribution in urban areas.