• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2022년도 봄 학술논문 발표대회
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• pp.37-38
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• 2022

This study is attempted to propose an appropriate number of measurements by checking and statistically analyzing the change in hardness according to the number of measurements. As a result, there was no significant difference between the 20th and 30th data, and in the 10th case, the effect on errors occurring during measurement was found to be dominant. Therefore, as the number of measurements, proposing 20 times in consideration of the convenience of use. In addition, in order to minimize the effect on the measurement error, it is proposed to remeasure the surface mane of the measurement surface and the test value in which the error occurs on the average of the test values.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2004년도 제29회 KOSCI SYMPOSIUM 논문집
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• pp.91-96
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• 2004

Simultaneous CH and OH planar laser induced fluorescence(PLIF) and stereoscopic particle image velocimetry (PIV) measurements have been developed to investigate the local flame structure of turbulent premixed flames. The developed simultaneous two radical concentrations and three component velocity measurements on a two-dimensional plane was applied for relatively high Reynolds number turbulent premixed flames in a swirl stabilized combustor. All measurements were conducted for methane-air premixed flames in the corrugated flamelets regime. Strong three-dimensional fluctuation implies that misunderstanding of the flame/turbulent interactions would be caused by the analysis of two-component velocity distribution in a cross section. Furthermore, comparisons of CH-OH PLIF and three-component velocity field show that the burned gases not always have high-speed velocity in relatively high Reynolds number turbulent premixed flame. The Reynolds number dependence of the flame front was clearly captured by the simultaneous CH-OH PLIF and stereoscopic PIV measurements.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제10권1호
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• pp.58-78
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• 2016

Compressed sensing (CS) possesses the potential benefits for spectrum sensing of wideband signal in cognitive radio. The sparsity of signal in frequency domain denotes the number of occupied channels for spectrum sensing. This paper presents a scheme of adaptively adjusting the number of compressed measurements to reduce the unnecessary computational complexity when priori information about the sparsity of signal cannot be acquired. Firstly, a method of sparsity estimation is introduced because the sparsity of signal is not available in some cognitive radio environments, and the relationship between the amount of used data and estimation accuracy is discussed. Then the SNR of the compressed signal is derived in the closed form. Based on the SNR of the compressed signal and estimated sparsity, an adaptive algorithm of adjusting the number of compressed measurements is proposed. Finally, some simulations are performed, and the results illustrate that the simulations agree with theoretical analysis, which prove the effectiveness of the proposed adaptive adjusting of compressed measurements.

• Journal of Positioning, Navigation, and Timing
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• 제2권1호
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• pp.59-65
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• 2013

The signal broadcast from a GPS satellite experiences code delay and carrier phase advance while passing through the ionosphere, which causes a signal error. Many ionosphere models have been studied to correct this ionospheric delay error. In this paper, the ionosphere modeling for the Korean Peninsula was carried out using a spherical harmonics based model. In contrast to the previous studies, we considered a real-time ionospheric delay correction model using fewer number of basis functions. The modeling performance was evaluated by comparing with a grid model. Total number of basis functions was set to be identical to the number of grid points in the grid model. The performance test was conducted using the GPS measurements collected from 5 reference stations during 24 hours. In the test result, the modeling residual error was smaller than that of the existing grid model. However, when the number of measurements was small and the measurements were not evenly distributed, the overall trend was found to be problematic. For improving this problem, we implemented the modeling with additional virtual measurements.

• 제어로봇시스템학회논문지
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• 제19권3호
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• pp.209-218
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• 2013

Military surveillance systems with electro-optical sensors can be used to track a number of targets efficiently and reliably. In MTT (Multi-Target Tracking), joint events in which different tracks share the same measurements may occur. Measurement-to-track assignment are computationally challenging because of the number of operations increases exponentially with number of tracks and number of measurements. IHPDA (Integrated Highest Probability Data Association) based on a 2D-Assignment technique can find an optimal solution for measurement to track one-to-one assignments for complex environments. In this paper, LM-IHPDA (Linear Multi-Target IHPDA) which does not need to form all feasible joint events of association and thus the computational load is linear in the number of tracks and the number of measurements. Simulation studies illustrate the effectiveness of this approach in an infrared image environment.

• 한국지반공학회논문집
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• 제19권4호
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• pp.299-310
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• 2003

SASW 실험으로 지반의 전단강성 구조를 구하는 해석과정에 있어서 위상속도의 계산은 SASW 실험의 신뢰도를 좌우하는 매우 중요한 단계이다. 기존의 SASW 자료 분석기법 중 위상속도의 계산은 전문가적 경험을 이용한 위상각 스펙트럼의 분석이 선행되어야 하는데, 위상각 스펙트럼 분석 과정의 난해성은 SASW 기법의 일반화에 장애가 되어 왔었다. 본 연구에서는 SASW 기법에 적용가능하고, 위상속도 계산에 전문가적 경험을 배제할 수 있으며, 자동화함으로써 효율성을 제고할 수 있는 위상속도 계산 기법을 제안하였다. 본 연구에서 제안한 기법은 다층구조 지반에서의 표면파의 주파수파수 특성을 이용하였으며, 그 개념에 기초하여 주파수파수 기법(Frequency-Wave Number Technique)이라고 하였다. 본 연구에서 제안한 기법의 신뢰성을 검증하기 위하여, SASW 수치실험을 수행하였다. 그리고 SASW 수치실험에 의해 구한 이론 전달함수로부터 위상속도를 계산하여, 위상각전개법으로 구한 위상속도와 비교 검토하였다. 또한, 경기도$\bigcirc$$\bigcirc$ 지구에서 수행한 SASW 실험자료에 대해 본 연구에서 제안한 기법을 적용하여 현장적용성 및 실용성을 확인하였다.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2008년도 International Meeting on Information Display
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• pp.947-950
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• 2008

This paper reports of traceable and repeatable time resolved colorimetric measurements of the luminance- and colour variation occurring during the frame refresh period of FPD's. During one frame period a number of measurements are performed, and for the dynamic artifacts a simulated smooth pursuit eye tracking algorithm is included.

• Nuclear Engineering and Technology
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• 제52권8호
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• pp.1807-1816
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• 2020

In this work, a Gaussian Process (Kriging) approach is proposed to provide efficient dose mapping for complex radiation fields using limited number of responses. Given a few response measurements (or simulation data points), the proposed approach can help the analyst in completing a map of the radiation dose field with a 95% confidence interval, efficiently. Two case studies are used to validate the proposed approach. The First case study is based on experimental dose measurements to build the dose map in a radiation field induced by a D-D neutron generator. The second, is a simulation case study where the proposed approach is used to mimic Monte Carlo dose predictions in the radiation field using a limited number of MCNP simulations. Given the low computational cost of constructing Gaussian Process (GP) models, results indicate that the GP model can reasonably map the dose in the radiation field given a limited number of data measurements. Both case studies are performed on the nuclear engineering radiation laboratories at the University of Sharjah.

• 한국수학사학회지
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• 제18권3호
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• pp.55-66
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• 2005

현재 학교수학에서는 소수를 기초로 무리수와 실수를 지도한다. 이와 관련하여, 이 글에서는 역사적 분석을 통하여 무한소수에 의한 실수와 무리수 정의의 본질을 확인하였다. 역사적으로 실수의 형성은 모든 크기의 수치화, 무리수의 형성은 통약 불가능한 양의 수치화라는 의미를 가지고 있다. 이러한 역사적 분석에 기초하여 실수 개념에의 의미있는 접근을 기대할 수 있는 구체적 지도 방안을 제안하였다.

• 한국한의학연구원논문집
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• 제18권3호
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• pp.111-118
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• 2012

Objective : The aim of this study was to investigate the number of measurements and visits for blood pressure measurement. We also analyzed the change of blood pressure based on the measurement method and measurement interval. Methods : Data of three clinical trials evaluating the effect of acupuncture, moxibustion, and qigong for pre and mild essential hypertension were used. Blood pressure was measured 3 times each visit with 1 or 5 minutes interval, and it was checked until $3^{rd}$ visit. Two trials used sphygmomanometer and another one trial used automatic device for blood pressure measurement. Results : The mean difference between $1^{st}$ and $2^{nd}$, and $2^{nd}$ and $3^{rd}$ measurement were significant in systolic (p<0.001) and diastolic blood pressure (p<0.001). However, in automated measurement or measuring with 1 minute interval, the difference between $2^{nd}$ and $3^{rd}$ was not significant. The mean of $1^{st}$ and $2^{nd}$ measurements was also significantly different from the mean of all three measurements in both systolic (p<0.001) and diastolic blood pressure (p<0.001). While the difference between each visit was not significant in diastolic blood pressure, the systolic blood pressure difference was significant between $1^{st}$ and $2^{nd}$ visit in automated and manual measurement. Conclusion : The mean of two measurements and three measurements were significantly different. The change of blood pressure was different according to the method and interval of blood pressure measurement.