• 한국지반신소재학회논문집
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• 제14권1호
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• pp.59-65
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• 2015

TDR을 이용한 흙의 건조밀도와 함수비의 새로운 보정 방정식을 검증하기 위해 본 연구를 수행하였다. 기존의 보정 방정식이 제안되고 몇몇 연구자들에 의해 새로운 보정 방정식을 개발하는 연구가 진행되고 있다. 기존의 보정 방정식이 함수비가 높은 세립토와 느슨한 토질에서는 적용되기 어려워 새로운 보정 방정식을 개발하였다. 이에 따라 본 연구에서는 새로운 보정 방정식을 소개하고 기존의 실험과 비교해 새로운 보정방정식의 국내지반과의 적용성을 검토를 수행하였다. 그 결과 함수비의 보정방정식에 오차가 발생하여 함수비의 새로운 보정방정식을 개발하였고, 개발한 보정방정식을 검토한 결과 95%이상의 정확도를 보여준다.

• 항공우주기술
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• 제12권2호
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• pp.147-155
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• 2013

천리안위성 기상탑재체 적외채널의 복사보정에서는 기본 복사보정식을 기반으로 다섯 개의 알고리즘이 추가되어 있다. 일반적으로 기하보정은 복사보정 이후 수행하므로, 복사보정 완료시각은 기하보정 처리의 시작시각을 결정한다. 본 논문에서는 기하보정 처리의 시작시각을 앞당기는 방법을 제안하기 위해서, 기본 복사보정 및 정밀 복사보정(기본 복사보정에 다섯 개의 알고리즘 추가) 결과를 입력으로 수행한 기하보정 처리의 정확도를 비교 분석한 내용을 정리하였다. 처리 속도가 빠른 기본 복사보정의 결과와 정확한 복사보정 값을 포함하는 정밀복사보정의 결과를 입력으로 각각의 기하보정 처리의 정확도를 분석하는 실험을 수행하였고, 두 경우 모두 기하보정 정확도 요구사항을 만족시킴을 검증하였다. 따라서 기하보정 처리 속도를 향상시키기 위해서, 기본 복사보정식으로 생성된 결과를 기하보정 처리의 입력으로 사용할 수 있음을 확인하였다.

• 한국연초학회지
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• 제21권1호
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• pp.95-101
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• 1999

This study was carried out to analyze chemical components in burley tobacco using near infrared spectroscopy(NIRS). Samples were collected in '96 and '97 crop year. Calibration equations were developed by modified partial least square. The standard error performance(SEP) of '96 crop year samples between NIRS and standard laboratory analysis were 0.25% for nicotine, 0.18% for total nitrogen, 0.59% for crude ash, 0.32% for ether extracts, and 0.14% for chlorine, respectively. The analytical results of '97 crop year samples were similar to those of '96 crop year samples. The analytical result of '97 crop year samples analyzed by '96 calibration equation was more inaccurate than that of '96 crop year samples. The SEP of '96 or '97 crop year samples applying calibration equation derived from '96 plus '97 crop year samples was similar to that of '96 or '97 crop year samples analyzed by '96 or '97 calibration equation, respectively. The SEP of '97 crop year samples analyzed by calibration equation derived from '96 plus '97 crop year samples was more accurate than that of '97 crop year samples analyzed by '96 calibration equation. To improve the analytical inaccuracy caused by the difference of crop year between calibration and prediction samples, we need to include the prediction sample spectra which were different from calibration sample spectra in recalibration sample spectra, and then develop recalibration equation. The NIRS can apply to analyze burley leaf tobacco, leaf process or tobacco manufacturing process which were required the rapid analytical result.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 추계학술대회논문집B
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• pp.99-104
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• 2000

Calibration equation for Variable Temperature Anemometer(VTA) has been tested for measured velocity-output data and the calibration process has been compared with that of Constant Temperature Anemometer(CTA). VTA has greater sensitivity than that of any other conventional anemometers, but to be more popular technique in flow field measurement, simple, accurate and well established calibration process should be suggested. To meet this purpose, similar calibration method used for CTA has been adopted for VTA and finally calibration equation for VTA including the effect of temperature drift has been proposed.

• 한국연초학회지
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• 제22권1호
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• pp.76-83
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• 2000

This study was carried out to predict blending ratio of cut tobacco(CT), expanded stem(ES), and expanded cut tobacco(ECT) in cigarettes. CT, ES, and ECT samples from A brand were, ground and blended with reference to A blending ratio, and scanned by near infrared spectroscopy(NIRSystem Co., Model 6500). Calibration equations were developed and then determined blending ratio by NIRS. The standard error of calibration(SEC) and performance(SEP) of C factory samples between NIRS and known blending ratio were 0.97%, 1.93% for CT, 0.50%, 1.12 % for ES and 0.68%, 1.10% for ECT, respectively. The SEP of CT, ES and ECT of Band D factory samples determined by C factory calibration equation were more inaccurate than those of C factory samples determined by C factory calibration equations. These results were caused by the difference of CT, ES and ECT spectra followed by each factory. The SEP of CT, ES and ECT of Band D factories determined by calibration equations derived from each factory samples were more accurate than those of determined by calibration equation derived from C factory samples. Each factory SEP of CT, ES and ECT determined by calibration equation derived from all calibration samples(B+C+D factory) was similar to that determined by calibration equation derived from each factory samples. To improve the analytical inaccuracy caused by spectra difference, we need to apply a specific calibration equation for each factory sample. Data in development of specific calibrations between sample and NIRS spectra might supply a method for rapid determination of blending ratio of CT, ES, and ECT.

• 한국작물학회지
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• 제54권1호
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• pp.29-35
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• 2009

The aim of the present study was to update the calibration that is used for the measurement of the total nitrogen content in the rice plant samples by using the visible and near infrared spectrum. Before the equation merge, correlation coefficient of calibration equation for nitrogen content on each rice parts was 0.945 (Leaf), 0.928 (Stem), and 0.864 (Whole plant), respectively. In the calibration models created by each part in the rice plant under the various regression method, the calibration model for the leaf was recorded with relatively high accuracy. Among of those, the calibration equation developed by Partial least squares (PLS) method was more accurate than the Multiple linear regression (MLR) method. The calibration equation was sensitive based on variety and location variations. However, we have merged and enlarged various of the samples that made not only to measure the nitrogen content more accurately, but also later sampling populations became more diversified. After merging, $R^2$ value becomes more accurate and significantly to 0.950 (L.), 0.974 (S.), 0.940 (W.). Also, after removal of outlier, R2 values increased into 0.998, 0.995, and 0.997. In view of the results so far achieved, Standard error of prediction (SEP) and SEP (C) were reduced in the stem and whole plant. Biases were reduced in the leaf, stem as well as whole plant. Slopes were high in the stem. Standard deviation reduced in the stem but $R^2$ was high in the stem and whole plant. Result was indicated that calibration equation make update, and updating robust calibration equation from merge function and multi-variate calibration.

• 대한수의학회지
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• 제50권1호
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• pp.11-17
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• 2010

Linear and non-linear regressions were used to derive the calibration function for the measurement of roxithromycin plasma concentration. Their results were compared with weighted least squares regression by usual weight factors. In this paper the performance of a non-linear calibration equation with the capacity to account empirically for the curvature, y = ax$^{b}$ + c (b $\neq$ 1) is compared with the commonly used linear equation, y = ax + b, as well as the quadratic equation, y = ax$^{2}$+ bx + c. In the calibration curve (range of 0.01 to 10 ${\mu}g/mL$) of roxithromycin, both heteroscedasticity and nonlinearity were present therefore linear least squares regression methods could result in large errors in the determination of roxithromycin concentration. By the non-linear and weighted least squares regression, the accuracy of the analytical method was improved at the lower end of the calibration curve. This study suggests that the non-linear calibration equation should be considered when a curve is required to be fitted to low dose calibration data which exhibit slight curvature.

• 방사선산업학회지
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• 제11권1호
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• pp.27-31
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• 2017

Reliable follow-up of bone mineral density (BMD) by dual energy X-ray absorptiometry (DXA) is essential in clinical practice. When there is a difference in the BMD values from DXA systems in the same patient, cross calibration equation is required for the reliable follow-up. Unfortunately, no equation is existed in BMD measure between GE Lunar Prodigy Advance (US, GE Healthcare; LPA) and Osteosys Dexxum T (Korea, Osteosys; ODT) DXA systems. In this study, we evaluate the agreement of BMD values between LPA and ODT and suggest the cross calibration equation using European spine phantom (ESP) with two systems. We performed BMD measurements using ten scans with ESP in each DXA systems. We compared BMD values and calculated cross calibration equation by linear regression analysis. The comparison between the LPA and ODT bone densitometers used the ESP. Compared to the ESP BMD values, ODT underestimated 14.36% and LPA overestimated 12.96%. The average of total BMD measurement values acquired with ODT were 21.44% lower than those from LPA. Cross-calibration equation for LPA and ODT was derived from ESP. We calculated simple cross calibration equation for LPA and ODT DXA systems. Cross-calibration equation is necessary for the reliable follow-up of BMD values in two different systems.

• 한국연초학회지
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• 제20권2호
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• pp.183-190
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• 1998

This study was conducted to analyze chemical components in flue-cured tobacco using near infrared spectroscopy(NIRS). Samples were collected in '96 and '97 crop year and were scanned in the wavelengths of 400 ～ 2500 nm by near infrared analyzer(NIRSystem Co., Model 6500). Calibration equations were developed and then analyzed flue-cured samples by NIRS. The standard error of calibration(SEC) and performance (SEP) of '96 crop year samples between NIRS and standard laboratory analysis(SLA) were 0.18% and 0.24% for nicotine, 1.60% and 1.77% for total sugar, 0.13% and 0.15% for total nitrogen, 0.58% and 0.68% for crude ash, 0.23% and 0.28% for ether extracts, and 0.09% and 0.08% for chlorine, respectively. The coefficient of determination($R^2$) of calibration and prediction samples between NIRS and SLA of '96 crop year samples was 0.94～0.99 and 0.83～0.97 depending on chemical components, respectively. The SEC and SEP of '97 crop year samples were similar to those of '96 crop year samples. The SEP of '97 crop year samples which were analyzed using '96 calibration equation was 0.32 % for nicotine, 2.72% for total sugar, 0.14 % for total nitrogen, 1.00 % for crude ash, 0.48 for ether extracts and 0.17% for chlorine, respectively. The prediction result was more accurate when calibration and prediction samples were produced in the same crop year than those of the different crop year. The SEP of '96 and '97 crop year samples using calibration equation which was developed '96 plus '97 crop year samples was similar to that of '96 crop year samples using 96 calibration equation and that of '97 crop year samples using '97 calibration equation, respectively. The SEP of '97 crop year samples using calibration equation which was developed '96 plus '97 crop year samples was lower than that of '97 crop year samples analyzed by '96 calibration equation. To improve the analytical inaccuracy caused by the difference of crop year between calibration and prediction samples, we need to include the prediction sample spectra which are different from calibration sample spectra in recalibration sample spectra, and then develop recalibration equation. Although the analytical result using NIR is not as good as SLA, the chemical component analysis using NIR can apply to tobacco leaves, leaf process or tobacco manufacturing process which demand the rapid analytical result.

• 지구물리
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• 제7권4호
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• pp.237-245
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• 2004

밀도 검층에 미치는 각 영향 요소들을 검토하고 현행 사용자 보정의 한계와 문제점 파악을 위한 기초 실험이 수행되었다. 간접 보정 방법에 속하는 현행 사용자 보정을 물과 알루미늄 블럭을 사용하는 사용자 보정과 반감기 식을 이용한 사용자 보정으로 구분하여 분석하였으며 국내에서 처음 시도된 지구물리모형 시추공을 이용한 직접 보정 방법의 적용 결과와 비교, 분석되었고 이로부터 기존의 사용자 보정의 한계와 가능성을 평가할 수 있었다.