• Transactions of the Korean Society of Mechanical Engineers A
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• v.25 no.7
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• pp.1147-1154
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• 2001

One of major problems in analyzing failure mechanism of real components is the accurate measurement of crack size and shape. The DCPD(Direct Current Potential Drop) method has been widely used for the crack measurement of a structure and finite element analysis has been used for the derivation of calibration equations, which relates the potential drop with the crack depth. In this paper, finite element analyses were performed for semi-elliptical surface cracks with various crack shapes(a/c) and crack depths(a/t). As a result, a calibration equation has been derived for the measurement of a semi-elliptical surface crack in wide plates. Analytical results are compared with experimental results to evaluate the validity and the applicability of the derived equation. The proposed method is expected to provide efficient and accurate measurement of a surface crack during crack growth.

• Korean Journal of Remote Sensing
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• v.36 no.6_2
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• pp.1629-1634
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• 2020

It is essential to convert the Digital Number (DN) measured from Earth observing satellites into the physical parameter of radiance when deriving the geophysical parameter such as surface temperature in the satellite data processing. The purpose of this study is to update the DN·Radiance equation established from lab measurements, using the KOMPSAT-3A mid-wave infrared data and the MODTRAN radiative transfer model. Results of this study show that the improved DN·Radiance equation allows us to produce the realistic values of radiance. We expect in the forthcoming study that the radiances calculated as such should be more quantitatively validated with the use of relevant in-situ measurements and a radiative transfer model.

• Journal of the Korean Chemical Society
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• v.29 no.3
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• pp.265-270
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• 1985

Ta$_2$O$_5$, Nb$_2$O$_5$, SnO$_2$ and ZrO$_2$ in tin-slag samples were determined by X-ray fluorescence spectrometry using the dilution parameter method and the analytical results were compared with the data obtained by standard calibration curve method. Tin-slag samples and one standard sample having very similar composition to the tin-slags were diluted with a proper diluent (La$_2$O$_3$) to the ratio of 1: 1, 1 : 2, 1 : 3 and 1 : 4. After measuring the X-ray intensities of original and diluted samples, the values of dilution parameters were calculated by using the dilution parameter equation. Without any calibration curve, the analytical results were calculated from the equation including the dilution parameter term. The results were in good agreement with the reference data by the standard calibration curve method.

• Journal of the Korean Society for Precision Engineering
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• v.30 no.1
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• pp.77-84
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• 2013

Most research on the inkjet printing technology has focused on the development of inkjet head itself, and of process, not on the landing accuracy of the droplets to a target. Thus, this paper presents the modeling and experimental verification on the static landing accuracy and precision of the droplets from the magnetostrictive inkjet head. A simple model based on the angle deviation of a nozzle tip and on a distance to a substrate is considered, assuming that there is no ambient effect. The angle deviation of the nozzle tip is determined by using its digital image with the aid of a pixel calculation program, and the distance to the substrate is set to 1 mm. Three experiments have planned and preformed. The first experiment is to collect the initial data for the landing distribution of the droplets. The second experiment is to collect the repeatability data of the stage used. Then, these data are used to rederive the equation for the final landing position of the droplet. The final experiment is to verify the equation and to show the calibration results. The respective landing accuracy of the droplet after calibration on the x-axis and on y axis has improved from $338.51{\mu}m$ and $-133.63{\mu}m$ to $7.06{\mu}m$ and $13.11{\mu}m$. The respective percent improvement on the x-axis and on y axis reaches about 98 and about 90. The respective landing precision of the droplet after calibration on the x-axis and on y axis has improved from ${\pm}182.6{\mu}m$ and ${\pm}182.88{\mu}m$ to ${\pm}24.64{\mu}m$ and ${\pm}42.76{\mu}m$. The respective percent improvement on the x-axis and on y axis reaches about 87 and about 77.

• Korean Journal of Food Science and Technology
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• v.28 no.1
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• pp.40-43
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• 1996

Our objective was to evaluate the potential of near-infrared reflectance spectroscopy to determine the salt content of mayonnaise. The calibration equation for salt developed using partial least square regression was compared with conventional method. 100 samples for calibration set and 40 samples for validation set were used. The multiple correlation coefficient was 0.946 and standard error of prediction was 0.017, when calibration equation was applied to validation set. Near-infrared reflectance spectroscopy method for determining salt content of mayonnaise appears quite satisfactory to evaluate nondestructively.

• YAKHAK HOEJI
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• v.40 no.1
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• pp.72-77
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• 1996

Penicillin sensor was manufactured by immobillizing penicillinase with glutaraldehyde on the $H^+$-selective membrane based on PVC-COOH-TDDA. This membrane was not inter fered by $K^+$ ion in Pc-G potassium salt. When enzyme was immobilized with glutaraldehyde, the PVC-COOH matrix was more effective than PVC matrix. Calibration curve calculated from Nernst equation was not linear. But potential was relative to concentration of Pc-G. And maximal potentiometric velocity was also relative to concentration of Pc-G. Therefore, it may be applied to Michaelis-Menten equation. The penicillin sensor was useful for determination of Pc-G at concentration of 0.1~10mM level.

• Korean Journal of Optics and Photonics
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• v.29 no.2
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• pp.70-76
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• 2018

Comparison calibration equipment for infrared-radiation thermometers below $0^{\circ}C$ has been established, using a TRT2 (transfer radiation thermometer 2, HEITRONICS) as a transfer standard and an ME30 (Model: ME30, HEITRONICS) as a variabletemperature blackbody. The TRT2 was calibrated using three fixed points (Ice ($0.01^{\circ}C$), In ($156.5985^{\circ}C$), and Sn ($231.928^{\circ}C$)) and the Planckian Sakuma-Hattori equation, and including the interpolation and extrapolation errors at $-50^{\circ}C$ in the uncertainty. The pneumatic lid is installed upon opening of the ME30 and is opened for only 30 seconds for measuring the radiation temperature, which prevents formation of ice in the ME30 and also reduces the calibration time to half. The farther away from the $0{\sim}232^{\circ}C$ region, the larger the uncertainty of the comparison calibration equipment becomes. The expanded uncertainty of the comparison calibration equipment was estimated as 0.26 K at $-20^{\circ}C$.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.12
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• pp.1736-1740
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• 2004

Since the application of relatively high levels of heavy metals in the compost poses a potential hazard to plants and animals, the content of heavy metals in the compost with animal manure is important to know if it is as a fertilizer. Measurement of heavy metals content in the compost by chemical methods usually requires numerous reagents, skilled labor and expensive analytical equipment. The objective of this study, therefore, was to explore the application of near-infrared reflectance spectroscopy (NIRS), a nondestructive, cost-effective and rapid method, for the prediction of heavy metals contents in compost. One hundred and seventy two diverse compost samples were collected from forty-seven compost facilities located along the Han river in Korea, and were analyzed for Cr, As, Cd, Cu, Zn and Pb levels using inductively coupled plasma spectrometry. The samples were scanned using a Foss NIRSystem Model 6500 scanning monochromator from 400 to 2,500 nm at 2 nm intervals. The modified partial least squares (MPLS), the partial least squares (PLS) and the principal component regression (PCR) analysis were applied to develop the most reliable calibration model, between the NIR spectral data and the sample sets for calibration. The best fit calibration model for measurement of heavy metals content in compost, MPLS, was used to validate calibration equations with a similar sample set (n=30). Coefficient of simple correlation (r) and standard error of prediction (SEP) were Cr (0.82, 3.13 ppm), As (0.71, 3.74 ppm), Cd (0.76, 0.26 ppm), Cu (0.88, 26.47 ppm), Zn (0.84, 52.84 ppm) and Pb (0.60, 2.85 ppm), respectively. This study showed that NIRS is a feasible analytical method for prediction of heavy metals contents in compost.

• Journal of the Korean Society of Tobacco Science
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• v.17 no.2
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• pp.177-183
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• 1995

This study was conducted to develop the most precise NIR(near infrared spectrometric) calibration for rapid determination of chemical composition in ground samples of toasted burley tobacco using stepwise, stepup, principal component regression(PCR), partial least square(PLS) and modified partial least square(MPLS) calibration method. The number of wavelength(W) selected by stepup multiple linear regression using: second derivative spectra was as follows: total sugar(TS)-4 W, nicotine-9 W, total nitrogen(TN)-2 W, ash-8 W, total volatile base(TVB)-5 W, chlorine4 W, L of color-6 W, a of color-6 W and b of color-7 W. Comparing the calibration equations followed by each chemical components, the most precise calibration equation was MPLS for 75, a and b of color, PLS for nicotine, ash, TVB, chlorine and L of color and stepup for TN. The standard error of calibration(SEC) and standard error of performance(SEP) between result of near infrared analysis and standard laboratory analysis were 0.18, 0.40% for 75, 0.06, 0.08% for nicotine, 0.18, 0.16% for TN, 0.33, 0.46% for ash, 0.04, 0.03% for TVB, 0.08, 0.06% for chlorine, 0.54, 0.58 for L of color, 0.22, 0.22 for a of color and 0.27, 0.27 for b of color, respectively. The SEC and SEP of ash and TVB were within allowable error of standard laboratory analysis, nicotine, TN and chlorine were 1.2-2.0 times and 75 were 2.1-4.0 times larger than allowable error of standard laboratory analysis. The ratio of SEC and SEP to mean were 1.5, 1.6% for L of color, 3.7, 3.8% for a of color and 1.8, 1.8% for b of color, respectively. Key words : burley tobacco chemistry, near infrared spectroscopy.

• Journal of the Korean Institute of Intelligent Systems
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• v.21 no.5
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• pp.555-563
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• 2011

The goal of image calibration is to find a relation between image and world coordinates. Conventional image calibration uses physical camera model that is able to reflect camera's optical properties between image and world coordinates. In this paper, we try to calibrate images distortion using performance criterion-based polynomial model which assumes that the relation between image and world coordinates can be identified by polynomial equation and its order and parameters are able to be estimated with image and object coordinate values and performance criterion. In order to overcome existing limitations of the conventional image calibration model, namely, over-fitting feature, the performance criterion-based polynomial model is proposed. The efficiency of proposed method can be verified with 2D images that were taken by laser scan camera.