• 풍력에너지저널
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• 제10권3호
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• pp.5-11
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• 2019

This paper suggests and compares two algorithms, a moving average filter method and a method developed by the National Renewable Energy Laboratory (NREL), to verify the yaw control algorithm characteristic to reduce yaw error for a wind turbine. A characteristic change for yaw movement in accordance with control parameter change that consists of each control method has been verified. Also, yaw simulations were performed using nacelle wind data measured from two areas with different turbulence intensities and the yaw movement data in each area was compared. These two algorithms and real data were compared by calculating mean absolute error (MSE) and the number of yawing (NY). As a result of the analysis, the MSE values were not significantly different between the two algorithms, but the algorithm proposed by the NREL was found to reduce yaw movement by up to 50 percent more than the moving average filter method.

• Journal of applied mathematics & informatics
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• 제15권1_2호
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• pp.363-375
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• 2004

In this paper, We show that the bandpass random signals of the form ∑$_{\alpha}$$\alpha$$_{\alpha}$ a Sin(2$\pi$f$_{\alpha}$t + b$_{\alpha}$) where a$_{\alpha}$ being a random number in [0,1], f$_{\alpha}$ a random integer in a given frequency band, and b$_{\alpha}$ a random number in [0, 2$\pi$], generate Gaussian white noise signals and hence they are adequate for simulating Continuous Markov processes. We apply the result to the fluctuation-dissipation formula for the Johnson noise and show that the probability distribution for the long term average of the power of the Johnson noise is a X$^2$ distribution and that the relative error of the long term average is (equation omitted) where N is the number of blocks used in the average.error of the long term average is (equation omitted) where N is the number of blocks used in the average.

• 대한방사선기술학회지:방사선기술과학
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• 제46권1호
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• pp.9-14
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• 2023

When measuring cerebrovascular with 3D rotational angiography, the accuracy was verified by comparing the actual size and measurement size, respectively. It is intended to help select therapeutic materials and instruments during cerebrovascular intervention by comparing the average error rates for measured values in the 3DRA and CTA methods by examining with protocols such as brain CTA, which are always performed in emergency situations. The mean error rate between the groups of measurers was ±3.655% for radiation technologist and ±3.331% for university students, and the mean error rate of the student group was within tolerance (±10%), and the independent sample T-test result t =0.879, p=0.394 (p>0.05) showed no statistically difference between the two. In addition, the average error rate measured by both groups by 3DRA was measured below ±5% within the tolerance error rate (±10%), and most of CTA was measured within the tolerance range (±10%), but showed an average error rate of up to 5.65%, and the independent sample T-test result was statistically more accurate than 3DRA. Both the 3DRA method and the brain CTA method for measuring cerebrovascular size could be accurately measured within tolerance, but it would be better to measure cerebrovascular blood vessels using a more accurate 3DRA method during cerebrovascular intervention.

• 한국항해항만학회지
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• 제28권6호
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• pp.509-515
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• 2004

여객수와 화물량에 대한 예측은 터미널의 개발 및 계획, 선사의 적정선복량 화보를 위해 중요하다. 본 연구에서는 역전파 학습 알고리즘을 이용한 뉴럴네트웍을 이용하여 목포항 여객수와 화물량을 예측하였다. 그리고 이동평균법, 지수평활법, 뉴럴네트웍의 예측수행을 평균제곱오차, 절대평균오차로 비교하여 뉴럴네트웍의 예측수행능력이 우수함을 검정하였다. 또한 2005년 목포항 여객수와 화물량을 예측하여 여객선 선복량의 적정성을 분석하였다.

• 정보처리학회논문지A
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• 제12A권5호
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• pp.391-394
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• 2005

이 논문에서는 정적분의 수치계산 방법 중에 하나인 사다리꼴 공식의 평균오차를 zero mean-Gaussian을 이용하여 연구한다. 구간 [0,1]에 n개의 소구간을 잡고 계산의 단순화를 위하여 각 소구간의 길이가 같다고 하고 길이를 h라 하면, $r{\leq}2$일 때, 상수 $c_r$을 직접 계산하여 연속된 두개의 소구간 위에서 단순 사다리꼴공식과 복합 사다리꼴공식 사이의 평균오차가 $O(h^{2r+3})$임을 보인다.

• 디지털융복합연구
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• 제11권3호
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• pp.381-387
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• 2013

본 연구는 초등학교 6학년 학생들의 작문에 나타난 낱말의 형태적 오류를 분석한 글이다. 본 연구의 주요 결과는 다음과 같다. 첫째, 조사 대상 학생들의 글 분량을 보면, 조사 대상 학생들이 사용한 낱말 수는 모두 14,532개였고, 평균은 145.3개였다. 문장 수는 1903개였고 평균은 19.0개였다. 문장당 사용된 낱말은 평균 7.6개였다. 둘째, 연구 대상 100명 중 31명만이 오류가 없었고 69명은 하나 이상의 오류를 나타내었다. 이는 본 연구가 기초 문식성에 해당하는 내용임을 감안하면 높은 수치라고 볼 수 있다. 셋째, 낱말의 형태 오류는 준말(33.09%), 어미(27.70%), 기타 오류(19.78%), 어간(19.42%) 순으로 높게 나타났다. 본 연구의 결과는 초등학교 쓰기 교과서 집필과 초등학생을 대상으로 한 맞춤법 지도 내용 선정에 기여할 수 있다.

• 통합자연과학논문집
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• 제10권4호
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• pp.232-239
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• 2017

The researcher set up multiple sensor units on the road slope such as national highway and highway where there is a possibility of loss, and using the acceleration sensor built into the sensor unit the researcher will sense whether the inclination of the road slope occur in real time, and Based on the sensed data, the researcher tries to implement a system that detects collapse of road slope and dangerous situation. In the experiment of measuring the error between the actual measurement time and the judgment time of the monitoring system when judging the warning of the sensor and falling rock detection by using the acceleration sensor, the error between measurement time and the judgment time at the sensor warning was 0.34 seconds on average, and an error between measurement time and judgment time at falling rock detection was 0.21 seconds on average. The error is relatively small, the accuracy is high, and thus the change of the slope can be clearly judged.

• 호남수학학술지
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• 제29권2호
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• pp.245-257
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• 2007

We showed in [2] that if $r\leq2$, then the average error between simple Trapezoidal rule and the composite Trapezoidal rule on two consecutive subintervals is proportional to $h^{2r+3}$ using zero mean Gaussian distribution under the assumption that we have subintervals (for simplicity equal length) partitioning and that each subinterval has the length. In this paper, if $r\geq3$, we show that zero mean Gaussian distribution of average error between simple Trapezoidal rule and the composite Trapezoidal rule on two consecutive subintervals is bounded by $Ch^8$.

• Journal of applied mathematics & informatics
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• 제13권1_2호
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• pp.353-363
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• 2003

In [2], if ${\gamma}$ $\leq$ 2, the average error of the composite Trapezoidal rule on two consecutive intervals turned out to be proportional to h$\^$2r+3/ where ${\gamma}$ is the number of differentiablity and h is the length of each uniform subinterval of the interval [0, 1] In this paper, we show that if ${\gamma}$ $\geq$ 3, the average error of the composite Trapezoidal rule on two consecutive intervals is bounded by Ch$\^$8/.

• 전자공학회논문지A
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• 제32A권9호
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• pp.1177-1183
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• 1995

This paper proposes a new modulation scheme of $\pi$/4-DQPSK with stepped phase for a frequency selective fading channel. In the proposed modulation scheme, the phase of transmitted signal is shifted in the mid of a symbol duration in order to reduce the effect of multipath delay spread. It reduces the irreducible error of $\pi$/4-DQPSK over a frequency selective fading channel. It is shown that $\pi$/4-DQPSK with stepped phase achieves smaller average bit error probability than regular $\pi$/4- DQPSK by simulation. The former achieves much smaller average bit error probability than the latter for small TEX>${\tau}/T_{s}$.