• 한국전자파학회논문지
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• 제8권5호
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• pp.525-533
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• 1997

건축연구에서의 수분측정 방법을 개선하기 위하여 비파괴적인 수분측정기술을 응용하였다. 본 실험은 연속적이고 비파괴적인 측정에서의 핵심요소로서 자유공간에서의 혼 안테나를 사용하여 실험하였으며 사용한 기술은 마이크로파 브릿지 장치로서 9.5GHz의 주파수에서 함수율이 1~12% 범위의 모래수분을 측정하였다. 이로부터 대표적인 교정곡선을 구하였다. 이를 바탕으로 마이크로파를 이용한 석탄, 제지, 식품 미치 건축재료 등과 같은 비금속내의 수분측정이 가능함을 보였다.

• 핵의학기술
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• 제20권2호
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• pp.75-79
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• 2016

Purpose The ASAN Medical Center, Nuclear Medicine performs TSH (Thyroid stimulating hormone) and FT4 (Free Thyroxine) tests 8 times per day. Accordingly, 70 ~ 80 kit tubes are consumed every day for the measurements and the time consumed for reagent dispensing averages over 170 seconds, where the TAT (turnaround time) may be effected when the number of test samples is larger than expected. Therefore, the following test was conducted with the purpose to reduce the number of kit tubes consumed, and reduce the time for reagent dispensing. Materials and Methods The test is based on applying the same reagent for tests where the number of samples is 30 or less. The test for TSH was conducted 9 times from July $1^{st}$ 2015 to July $10^{th}$ 2015. The test for FT4 was conducted 4 times from June $18^{th}$ 2015 to June $22^{nd}$, 2015. Standard Solution No.2 (0.153 uU/mL) and No.5 (4.96 uU/mL) was selected as the two-point standards for the TSH test, and Standard Solution No.3 (0.777 ng/dL) and No.4 (2.044 ng/dL) was selected as the two-point standards for the FT4 test. 38 test samples were subject to correlation analysis. Results For TSH, the result of the normal test shows ranges of 0.20 ~ 0.37 uU/mL for Control1, 0.53 ~ 0.71 uU/mL for Control2, and 6.77 ~ 7.94uU/mL for Control3, while the result of two-point calibration curve test shows ranges of 0.18 ~ 0.27 uU/mL for Control1, 0.53 ~ 0.71 uU/mL for Control2, and 7.30 ~ 8.52 uU/mL for Control3. For FT4, the result of the normal test shows ranges of 0.85 ~ 0.94 ng/dL for Control1 and 4.23 ~ 4.57 ng/dL for Control2, while the result of two-point calibration curve test shows ranges of 0.61 ~ 0.75 ng/dL for Control1 and 3.88 ~ 5.71 ng/dL for Control2. For TSH, the CV% of the normal test for Control1, Control2 and Control3 are 10.5, 3.3 and 3.6 respectively, while the CV% of the two-point calibration curve test for Control1 and Control1 are 12.4, 8.2 and 5.1 respectively. The result shows an outstanding correlation of TSH: y = 0.9985x - 0.0459 $R^2=0.9986$. For FT4, the CV% of the normal test for Control1 and Control2 are 0.70 and 0.71 respectively, while the CV% of the two-point calibration curve test for Control1 and Control1 are 8.7 and 16.2 respectively. The result shows an outstanding correlation of FT4: y = 1.2674x - 0.1133 $R^2=0.9824$. Conclusion The two-point calibration curve can be efficiently applied for TSH in cases where the number of test samples is not large, since the number of samples to be re-tested increases when the result is abnormal from the calibration curve. The two-point calibration curve test should not be applied for FT4 where the results do not consistently comply with the quality assessment range. Depending on how the two-point calibration curve is applied, up to 5 test tubes can be conserved per test, and the reduced time for reagent dispensing is anticipated to have a positive effect on the TAT (turnaround time).

• 한국정밀공학회지
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• 제31권7호
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• pp.605-613
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• 2014

Scanning white-light interferometry is an important measurement option for many surfaces. However, serious profile measurement errors can be present when measuring free-form surfaces being highly curved or tilted. When the object surface slope is not zero, the object and reference rays are no longer common path and optical aberrations impact the measurement. Aberrations mainly occur at the beam splitter in the interference objective and from misalignment in the optical system. Both effects distort the white-light interference signal when the surface slope is not zero. In this paper, we describe a modified version of white-light interferometry for eliminating these measurement errors and improving the accuracy of white-light interferometry. Moreover, we report systematic errors that are caused by optical aberrations when the object is not flat, and compare our proposed method with the conventional processing algorithm using the random ball test.

• 한국소음진동공학회논문집
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• 제18권6호
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• pp.598-605
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• 2008

An improved beamforming method is proposed to measure the surface impedance of absorbing materials in a free field. It is possible to estimate the surface impedance by decomposing measured signals into incident and reflected signals by using the spatial filter matrix of the beamforming method. Wavelet do-noising techniques which reduce the white Gaussian noise are applied to improve the results. Phase calibration method is also used to improve the results of the measured surface impedance in a low frequency range. The results of the normal incidence experiments that are performed in a semi-anechoic chamber are verified by comparing with those of the standard test method that is presented in ASTM E1050. The proposed method is found to be reliable to measure the surface impedance for frequencies higher than 400 Hz.

• 신재생에너지
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• 제9권1호
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• pp.12-16
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• 2013

The nacelle anemometer mounted behind the blade roots of a wind turbine measures distorted wind speed comparable with free-stream wind because of the wake effects caused dependent upon the operation of the wind turbine and the rotation of its blades. The field campaign was carried out to measure free-stream wind speed at a height identical to the height of the nacelle anemometer by deploying a ground-based remote-sensing equipment, LIDAR. It is derived that a third-order polynomial equation for correcting wind speed measured by the nacelle anemometer to undistorted free-stream wind speed incident to a wind turbine. It is anticipated that the derived correction equation enables wind speed measured by the nacelle anemometer to be used as a precise input for a wind turbine performance test and for developing an active control logic.

• Journal of Mechanical Science and Technology
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• 제17권10호
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• pp.1411-1422
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• 2003

The detection of free spaces between obstacles in a scene is a prerequisite for navigation of a mobile robot. Especially for stereo vision-based navigation, the problem of correspondence between two images is well known to be of crucial importance. This paper describes multi-range approach of area-based stereo matching for grid mapping and visual navigation in uncertain environment. Camera calibration parameters are optimized by evolutionary algorithm for successful stereo matching. To obtain reliable disparity information from both images, stereo images are to be decomposed into three pairs of images with different resolution based on measurement of disparities. The advantage of multi-range approach is that we can get more reliable disparity in each defined range because disparities from high resolution image are used for farther object a while disparities from low resolution images are used for close objects. The reliable disparity map is combined through post-processing for rejecting incorrect disparity information from each disparity map. The real distance from a disparity image is converted into an occupancy grid representation of a mobile robot. We have investigated the possibility of multi-range approach for the detection of obstacles and visual mapping through various experiments.

• Journal of Pharmaceutical Investigation
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• 제22권1호
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• pp.63-68
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• 1992

An HPLC procedure with UV detection has been developed for the quantitation of flurbiprofen released into isopropyl myristate used as the receptor phase in an in vitro membraneless drug diffusion cell. The drug and the internal standard (oxaprozin) were extracted from isopropyl myristate with a mixture of dimethylsulfoxide:methanol:water (2:1:1) and quantitated using a reverse phase $C_{18}$ column. The chromatograms were completely free from interfering peaks, and the relative retention times of flurbiprofen and the internal standard were 4.9 and 6.8 min, respectively. Calibration plots were linear over the concentration range of $1-200\;{\mu}g/ml$ of flurbiprofen with correlation coefficients, all higher than 0.99. The mean intra-day precision and accuracy among three replicate sets of the assay in a day were 4.26 and 4.52%, respectively, whereas the mean inter-day precision and accuracy were 3.35 and 3.64%, respectively. The mean recovery of the drug was 92.5% over the calibration range. The method was simple, reliable and accurate for the quantitation of flurbiprofen in unpurified isopropyl myristate.

• 대한방사선치료학회지
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• 제6권1호
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• pp.56-60
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• 1994

In the past, brachytherapy was carried out mostly with radium or radon sources. Currently. use of artificially produced radionuclially produced radionuclides such as $^{137}Cs,\;^{192}Ir,\;^{198}Au,\;and\;^{125}I$ is rapidly increasing. Although electrons are often used as an alternative to interstitial implants, brachytherapy continues to remain an important mode of therapy, either alone or combined with external beam. The National Council on Radiation Protection and Measurements(NCRP) recommends that the strength of any ${\gamma}$ emitter should be specified directly in terms of exposure rate in air at a specified distance such as 1m. The air kerma strength is defined as the product of air kerma rate in 'free space' and the square of the disrance of the calibration point from the source center along the perpendicular bisector, i. e., $S_k=K_L{\times}L^2$. Where $S_K$ is the the air kerma strength and K is the air kerma rate at a specified distance L. (usually 1m). Recommended units for all kerma strength are ${\mu}Gym^{2}h^{-1}$.

• 방송공학회논문지
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• 제4권2호
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• pp.87-102
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• 1999

가상의 삼 차원 컴퓨터 그래픽 영상을 실제 비디오 영상과 합성하는 증강현실을 구현하기 위해서는 카메라의 초점거리 같은 내부변수와 카메라가 어떻게 움직였는지를 나타내는 회전 및 직선 운동에 대한 이동정보가 반드시 필요하다. 따라서, 기존의 방법들은 미리 카메라의 내부변수를 계산해 둔 다음, 실제 영상에서 얻어지는 정보를 이용하여 카메라의 이동정보를 계산하거나, 실제 영상에 카메라 보정을 위한 삼 차원 보정 패턴이 보이도록 한다음 영상에서 그 패턴의 형태를 분석하여 카메라의 내부변수와 운동정보를 동시에 계산하는 방법을 사용하였다. 이 논문에서는 실제 영상에서 얻어지는 정합점들로부터 카메라 조정없이 구할 수 있는 투영기하공간 카메라 이동정보를 이용하여 증강현실을 구현하는 방법을 제안한다. 실제 카메라의 내부변수와 유클리드공간 이동정보를 대신하기 위하여 가상카메라를 정의하며, 가상카메라는 실제공간과 가상 그래픽 공간의 연결을 위하여 두 장의 영상에 사용자가 삽입하는 가상공간 좌표계의 기준점들의 영상좌표로부터 구해진다. 제안하는 방법은 카메라의 내부변수에 대한 정보를 따로 구할 필요가 없으며 컴퓨터 그래픽이 지원하는 모든 기능을 비유클리드공간의 정보로도 구현이 가능하다는 것을 보여준다.

• 한국축산식품학회지
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• 제40권6호
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• pp.896-907
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• 2020

Imaging technique or computer vision (CV) technology has received huge attention as a rapid and non-destructive technique throughout the world for measuring quality attributes of agricultural products including meat and meat products. This study was conducted to test the ability of CV technology to predict the quality attributes of beef. Images were captured from longissimus dorsi muscle in beef at 24 h post-mortem. Traits evaluated were color value (L*, a*, b*), pH, drip loss, cooking loss, dry matter, moisture, crude protein, fat, ash, thiobarbituric acid reactive substance (TBARS), peroxide value (POV), free fatty acid (FFA), total coliform count (TCC), total viable count (TVC) and total yeast-mould count (TYMC). Images were analyzed using the Matlab software (R2015a). Different reference values were determined by physicochemical, proximate, biochemical and microbiological test. All determination were done in triplicate and the mean value was reported. Data analysis was carried out using the programme Statgraphics Centurion XVI. Calibration and validation model were fitted using the software Unscrambler X version 9.7. A higher correlation found in a* (r=0.65) and moisture (r=0.56) with 'a*' value obtained from image analysis and the highest calibration and prediction accuracy was found in lightness (r²_c=0.73, r²_p=0.69) in beef. Results of this work show that CV technology may be a useful tool for predicting meat quality traits in the laboratory and meat processing industries.