• 한국가스학회지
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• 제18권1호
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• pp.8-16
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• 2014

본 연구에서는 국내에서 발생한 가스사고를 분석하여 가스사고의 건수예측모델에 대하여 제시하였다. 가스사고 건수를 예측하기 위하여 단순이동평균법(3,4,5기간), 가중이동평균법 및 지수평활법을 적용해 본 결과, 4기간 이동평균법과 가중이동평균법에 의한 모델의 평균오차제곱합이 44.4와 43으로 가장 정확성이 높은 것으로 나타났다. 가스사고 발생건수 예측시스템을 개발함으로서 가스사고 예방활동에 적극 활용할 수 있을 것이다.

• 대한원격탐사학회지
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• 제30권4호
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• pp.505-510
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• 2014

NDVI는 기후변화 모니터링과 식생 변화 탐지 모니터링을 위한 주요한 지표이다. NDVI를 산출하기 전에 cloud masking, 대기보정과 같은 전처리 과정을 거침에도 불구하고 강수, 적설이나 구름의 영향이 완전히 제거되지 않아 NDVI가 현저히 낮게 관측되는 noise가 불규칙적으로 발생한다. 이러한 noise를 보정하기 위해서 국내외로 활발한 연구가 진행되고 있다. 기존의 다중 다항 회귀식을 이용한 방법에서는 과대추정이나 low peak를 잘 탐지하지 못하는 등 문제점이 나타나고 있으므로 보다 정확하게 noise를 보정하는 방법이 요구된다. 본 연구에서는 이동평균을 이용하여 noise를 보정하였고, 기존의 다중 다항 회귀식을 이용하여 산출한 NDVI 시계열과 비교를 해보았다. 그 결과 이동평균을 이용한 방법이 이전의 방법보다 NDVI noise를 잘 보정하는 것으로 보여진다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2004년도 학술대회지
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• pp.810-813
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• 2004

In this paper, a background initialization for video surveillance proposed. The proposed algorithm is that the background images are sampled n frames during ${\Delta}t$ All Sampling frames are divided by $M{\times}N$ size block every frame. Average values of pixels for same location block of the sampling frames during ${\Delta}t$t are taken. then the maximum intensity $\alpha$ and the minimun intensity $\beta$ is obtained, respecticely. The intial by $M{\times}N$ size block, then average intensity $\eta$ of pixels for the block is obtained. If the average intensity $\eta$ is out of the initial range of the background image, it is decided the moving object image, and if the average intensity $\eta$ is included in the initial range of the background image. it is decided the background image. To examine the propriety of the proposed algorithm in this paper, the accuracy and robustness evaluation results for human and car in the indoor and outdoor enviroment. the error rate of the proposed method is less than the existing methods and the extraction rate of the proposed method is better than the existing methods.

• 한국안전학회지
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• 제32권1호
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• pp.21-26
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• 2017

An IoT-based particulate matter (PM2.5) sensing device (PSD) is developed. The PSD consists of a PM2.5 sensor, signal processing circuit, and wi-fi enabled-microprocessor along with temperature and humidity sensors. The PSD estimates PM2.5 density by measuring light scattered by PM2.5. To gauge performance of the PSD, PM2.5 density of open air was measured with the PSD and compared with that of the collocated-government-certified measuring station. Measurements were taken at a sampling frequency of 100 Hz and moving-averaged to remove measurement noise. When compared to the result of the measuring station, average percentile error of PM2.5 density from the PSD is found to be 31%. A correlation coefficient is found to be 0.72 which indicates a strong correlation. Instantaneous variation, however, may far exceed average errors, leading to a conclusion that the PSD is more suitable for estimating average trend of PM2.5 density variations than estimating instantaneous PM2.5 density.

• 전기학회논문지
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• 제63권11호
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• pp.1497-1502
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• 2014

Electric load forecasting is essential for stable electric power supply, efficient operation and management of power systems, and safe operation of power generation systems. The results are utilized in generator preventive maintenance planning and the systemization of power reserve management. Development and improvement of electric load forecasting model is necessary for power system maintenance and operation. This paper proposes daily maximum electric load forecasting methods for the next 4 weeks with a seasonal autoregressive integrated moving average model and an exponential smoothing model. According to the results of forecasting of daily maximum electric load forecasting for the next 4 weeks of March, April, November 2010~2012 using the constructed forecasting models, the seasonal autoregressive integrated moving average model showed an average error rate of 6,66%, 5.26%, 3.61% respectively and the exponential smoothing model showed an average error rate of 3.82%, 4.07%, 3.59% respectively.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 학술회의 논문집 정보 및 제어부문 A
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• pp.199-202
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• 2003

An effective method is proposed for detecting, acquisition and tracking of a moving object using a disturbance map method in complex image sequences. A significant moving object is detected and tracked within the field of view by computing a modified disturbance map method between an Input image and a temporal average image. This method is very efficient in the serveillance application of digital CCTV and an automatic tracking camera. Experimental results using a real image sequence confirmed that the proposed method can effectively detect and track a significant moving object in complex image sequences.

• 조명전기설비학회논문지
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• 제20권9호
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• pp.45-53
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• 2006

This paper proposes a method for an effective intelligent route decision for automatic moving robots(AMR) using a 2D spatial map of a stereo camera system. In this method, information about depth and disparity map are detected in the inputting images of a parallel stereo camera. The distance between the automatic moving robot and the obstacle is detected, and a 2D spatial map is obtained from the location coordinates. Then the relative distances between the obstacle and other objects are deduced. The robot move automatically by effective and intelligent route decision using the obtained 2D spatial map. From experiments on robot driving with 240 frames of stereo images, it was found that the error ratio of the calculated distance to the measured distance between objects was very low, 1.52[%] on average.

• Steel and Composite Structures
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• 제35권6호
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• pp.729-737
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• 2020

The goal of this study is to investigate dynamic responses of laminated composite beams under a moving load with thermal effects. The governing equations of problem are derived by using the Lagrange procedure. The transverse-shear strain and rotary inertia are considered within the Timoshenko beam theory. The material properties of laminas are considered as the temperature dependent physical property. The differential equations of the problem are solved by the Ritz method. The solution step of dynamic problem, the Newmark average acceleration method is used in the time history. A compassion study is performed for accuracy of used formulations and method. In the numerical results, the effects of velocity of moving load, temperature values, the fiber orientation angles and the stacking sequence of laminas on the dynamic responses of the composite laminated beam are investigated.

• Steel and Composite Structures
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• 제46권2호
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• pp.253-261
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• 2023

The goal of this paper is to investigate dynamic responses of simply-supported laminated micro beams under moving load. In the considered micro-scale problem, the modified coupled stress theory which includes the length scale parameter is used. The governing equations of problem are derived by using the Lagrange procedure. In the solution of the problem the Ritz method is used and algebraic polynomials are used with the trivial functions for the Ritz method. In the solution of the moving load problem, the Newmark average acceleration method is used in the time history. In the numerical examples, the effects of stacking sequence of laminas, fibre orientation angles and the length scale parameter on the dynamic responses of laminated micro beams are examined and discussed.

• 한국게임학회 논문지
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• 제17권4호
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• pp.55-62
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• 2017

본 연구에서는 HMD(Head Mounted Display)를 가지고 Walk-through의 이동시뮬레이션에 대한 평가를 실시하였다. 구체적으로는 VR공간 주변에 배치된 오브젝트 밀집정도(밀도)의 변화가 심리적 이동거리, 이동속도, 이동시간에 어떠한 영향을 미치는지 알아보았다. 연구결과 첫째, 실험 조건 (저밀도, 중밀도, 고밀도)에 있어 조건간의 차이는 모두 유의미하였다. 둘째, 주변 오브젝트의 밀도가 높아질수록 이동시간, 이동속도, 이동거리가 기본조건과 비교하여 평균점이 높게 나타났다. 셋째, 주변의 오브젝트가 VR공간의 이동시뮬레이션에 있어 시간, 속도, 거리의 감각을 향상 시키는 것을 확인하였다.