• Journal of Information Processing Systems
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• 제15권2호
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• pp.331-343
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• 2019

Dynamic thermal rating of the overhead transmission lines is affected by many uncertain factors. The ambient temperature, wind speed and wind direction are the main sources of uncertainty. Measurement uncertainty is an important parameter to evaluate the reliability of measurement results. This paper presents the uncertainty analysis based on Monte Carlo. On the basis of establishing the mathematical model and setting the probability density function of the input parameter value, the probability density function of the output value is determined by probability distribution random sampling. Through the calculation and analysis of the transient thermal balance equation and the steady- state thermal balance equation, the steady-state current carrying capacity, the transient current carrying capacity, the standard uncertainty and the probability distribution of the minimum and maximum values of the conductor under 95% confidence interval are obtained. The simulation results indicate that Monte Carlo method can decrease the computational complexity, speed up the calculation, and increase the validity and reliability of the uncertainty evaluation.

• 천문학회보
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• 제43권2호
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• pp.45.3-46
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• 2018

Oscillations in a sunspot are easily detected through the Doppler velocity observation. Although the sunspot oscillations look erratic, the wavelet analysis show that they consist of successive wave packets which have strong power near three or five minutes. Previous studies found that 3-min oscillation at the chromosphere is a visual pattern of upward propagating acoustic waves along the magnetic field lines. Resent multi-height observations help this like vertical study, however, we also focus on horizontal facet to extend three dimensional understand of sunspot waves. So, we investigate a fragmented sunspot expected to have complex wave profiles according to the positions in the sunspot observed by the Fast Imaging Solar Spectrograph. We choose 4 points at different umbral cores as sampling positions to determine coherence of oscillations. The sets of cross-correlation with three and five minutes bandpass filters during a single wave packet reveal interesting results. Na I line show weak correlations with some lags, but Fe I and Ni I have strong correlations with no phase difference over the sunspots. It is more remarkable at Ni I line with 3-min bandpass that all sets of cross-correlation look like the autocorrelation. We can interpret this as sunspot oscillations occur spontaneously over a sunspot at photosphere but not at chromosphere. It implies a larger or deeper origin of 3-min sunspot oscillation.

• 한국산학기술학회논문지
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• 제18권9호
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• pp.411-417
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• 2017

농업부문의 에너지 관련 정책의 합리적인 수립을 위해서 농업부문의 에너지 수급을 예측하고, 농가 에너지 소비현황을 파악해야 한다. 특히 에너지원별 및 작물별 소비량을 파악하는 것이 중요하다. 또한 최근 기후 온난화에 대응하여 세계는 온실가스를 의무적으로 감축하고자 하며, 우리나라도 2020년 까지 온실가스 배출 전망치의 30%를 감축하기로 하고, 관련법을 제정하였다. 국가 온실가스 감축목표 달성을 위해 농림어업부문은 5.2%의 감축목표를 설정하였다. 농업부문 온실가스 배출은 에너지 소비와 관련되어 있어 감축목표 이행을 위한 합리적인 정책 수립을 위해서 작물별 및 에너지원별 온실가스 배출량 수준을 파악하는 것이 필요하다. 이 연구는 농업부문 탄소배출량 및 에너지 소비량 수준을 파악하기 위해 기반이 되는 표본설계에 중점을 두고, 조사 및 추정 오차를 줄이고, 신뢰도를 높일 수 있는 설계 방안을 제안하고 있다. 농업부문 에너지 소비실태 조사를 위한 모집단을 농업총조사 자료를 기준으로 설정하였고, 왜도(Skewness)가 높은 품목과 전국적으로 재배가 분산된 품목들에 대해서는 주산지를 대상으로 표본 추출틀을 설정하는 등 통계적으로 유의한 범위에서 규모를 절사하였다. 표본의 수는 품목별 각 층의 경계를 결정한 이후 95% 신뢰수준을 활용하여 네이만 할당방식에 의해 설정되었다. 또한 이 연구는 품목별로 추출된 표본을 이용하여 도출된 추정결과와 모수를 비교 검정하고, 오차를 관리하는 방법을 제안하고 있다.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2005년도 Proceedings of ISRS 2005
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• pp.182-185
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• 2005

Satellite cameras are calibrated before launch in detail and in general, but it cannot be guaranteed that the geometry is not changing during launch and caused by thermal influence of the sun in the orbit. Modem satellite imaging systems are based on CCD-line sensors. Because of the required high sampling rate the length of used CCD-lines is limited. For reaching a sufficient swath width, some CCD-lines are combined to a longer virtual CCD-line. The images generated by the individual CCD-lines do overlap slightly and so they can be shifted in x- and y-direction in relation to a chosen reference image just based on tie points. For the alignment and difference in scale, control points are required. The resulting virtual image has only negligible errors in areas with very large difference in height caused by the difference in the location of the projection centers. Color images can be related to the joint panchromatic scenes just based on tie points. Pan-sharpened images may show only small color shifts in very mountainous areas and for moving objects. The direct sensor orientation has to be calibrated based on control points. Discrepancies in horizontal shift can only be separated from attitude discrepancies with a good three-dimensional control point distribution. For such a calibration a program based on geometric reconstruction of the sensor orientation is required. The approximations by 3D-affine transformation or direct linear transformation (DL n cannot be used. These methods do have also disadvantages for standard sensor orientation. The image orientation by geometric reconstruction can be improved by self calibration with additional parameters for the analysis and compensation of remaining systematic effects for example caused by a not linear CCD-line. The determined sensor geometry can be used for the generation? of rational polynomial coefficients, describing the sensor geometry by relations of polynomials of the ground coordinates X, Y and Z.

• 한국운동역학회지
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• 제27권4호
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• pp.279-285
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• 2017

Objective: The purpose of this study was to perform a muscle function path analysis of muscle function on myofascial meridians. Method: Seven male students (mean age: $22{\pm}3.46years$; mean mass: $72.71{\pm}8.19kg$; mean height: $174{\pm}4.39cm$) without a history of musculoskeletal system symptoms or injuries were recruited for this study. The measurement muscle of the myofascial line was selected along with the muscle presented in "anatomy trains (Thomas W. Myers. 2014)", and the attachment of the surface EMG (Telemyo 2400T G2, USA) pad was determined according to "EMG analysis (Kim Tae Wan et al., 2013)". The subjects underwent maximum volumetric contraction of their fascia line end muscles three times in lying and standing postures and were subjected to the maximum number of contractions of the myofascial line muscle three times in the lying and standing postures. The sampling rate of the EMG signal was set to 1,000 Hz, and the bandwidth was 20 to 350 Hz. The activity of each muscle was quantitated using the Pearson correlation coefficient, and SPSS 22.0 was used for data analysis. Results: In myofascial meridians, a positive correlation in the myofascial connection and a negative correlation in the mechanical connection were observed. Conclusion: Muscles that show significant contract correlations with one another may be expected to be used as an effective clinical marker in muscle strengthening or relaxation therapy, and rehabilitative training. In this study, the correlation of total myofascial meridians may differ without consideration of functional posture. Future studies need to consider these points.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 하계학술대회 논문집 Vol.9
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• pp.518-518
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• 2008

현재 전차선 높이 및 편위 측정을 위한 측정시스템은 원천기술 자체를 독일, 일본, 프랑스, 이탈리아에서 제품개발 이전에 기술 특허를 출원하여 선점이 되어있어 국내 전차선에 적합하고 정밀도가 높은 기술 개발과 더불어 측정을 위한 원천기술의 자체개발이 필요하다. [1, 2] 따라서, 독자적이고 독립적인 원천기술을 개발하고 객관적 검증을 위해 기초시험과 이미지프로세싱 기법을 이용한 선형화로 원천, 측정기술 확보와 동시에 실질적 기술 검증이 필요하다. 이를 위해 Line Scan Camera 및 시스템 구성 후 시험을 위해 카메라고정과 모의시험을 위해 지그를 제작하였으며 측정된 데이터를 저장하고 Line Scan Camera를 동작하기 위한 프로그램을 개발하여 이를 구현하고자 하였다.

• 지구물리
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• 제3권4호
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• pp.215-226
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• 2000

갈곡단층이 통과하는 경주시 천북목장 부근의 단구면상에서 기반암의 분포를 파악하고, 비교적 규모가 큰 파쇄대를 인지하기 위하여 굴절법 탐사를 실시하였다. 동서방향으로 길이 72m인 측선 1과 남북방향으로 각각 72m, 36m인 측선 2와 3의 굴절파 측선을 따라 5kg의 해머로 발생시킨 지진파를 3m 간격으로 배열된 8Hz 수직지오폰 12개를 이용하여 디지털 방식으로 192ms 기록하였다. GRM 방법으로 해석한 결과, 속도와 두께는 각각 250m/s, 평균 2.1m이며, 표층의 하부에는 속도가 약 $1,030{\sim}1,400m/s$정도이고 두께가 4.6m인 제 4기 후기 자갈층이 존재한다. 이 층의 하부는 기반암으로서 속도 $2,100{\sim}2,200m/s$의 제 3기 흑색 이암이 분포하는 것으로 해석된다. 측선 1과 측선 3의 일부구간은 굴절면의 깊이 차이가 수십 cm 이상으로 나타나 제4기 단층의 존재 가능성을 지시한다. 단구의 상단에 해당하는 측선 1의 동쪽 구간과 측선 3에서는 기반암 굴절파가 기록되지 않은 점으로 보아, 측선 1의 서쪽부분에 대규모 단층이 존재할 가능성이 매우 높다.

• Journal of Power Electronics
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• 제12권1호
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• pp.88-97
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• 2012

This paper presents a method for the digital control of a high power factor AC/DC converter employing the power balance control technique to achieve a fast response of the output voltage control. To avoid the effects of an output voltage ripple in the voltage control loop, the average output voltage is sampled and used as a feedback signal for the output voltage controller. The proposed control technique was verified by simulations using MATLAB/Simulink and its implementation was realized by a dsPIC30F4011 digital signal processor to control a CUK topology AC/DC converter with a 48V output voltage and a 250 W output power. The experimental results agree with the simulation results. The proposed control technique achieves a fast transient response with a lower line current distortion than is achieved when using a conventional proportional-integral controller and the power balance control technique with the conventional sampling method.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.762-766
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• 2003

In this paper, we present a new approach to solve the problem of estimating the camera 3-D location and orientation from a matched set of 3-D model and 2-D image features. An iterative least-square method is used to solve both rotation and translation simultaneously. Because conventional methods that solved for rotation first and then translation do not provide good solutions, we derive an error equation using roll-pitch-yaw angle to present the rotation matrix. To minimize the error equation, Levenberg-Marquardt algorithm is introduced with uniform sampling strategy of rotation space to avoid stuck in local minimum. Experimental results using real images are presented.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.327-332
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• 2003

A new discretization method for nonlinear system with time-delay is proposed. It is based on the well-known Taylor series expansion and the zero-order hold (ZOH) assumption. We know that a discretization of linear system can be obtained with the ZOH assumption and within the sampling interval. A similar line of thinking is available in nonlinear case. The mathematical structure of the new discretization method is explored and under the structure, the sampled-data representation of nonlinear system including time-delay is computed. Provided that the discrete form of the single input nonlinear system with time-delay is derived, this result is easily extended to nonlinear system with multi-input time-delay. For simplicity two inputs are considered in this study. It is enough to generalize that of multiple inputs. Finally, the time-discretization of non-affine nonlinear system with time-delay is investigated for apply all nonlinear system