• Proceedings of the KIEE Conference
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• 2002.07a
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• pp.298-300
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• 2002

The design of a measurement system to perform Harmonic State Estimation (HSE) is a very complex problem. In particular, the number of available harmonic instruments(Continuous Harmonic Analysis in Real Time : CHART) is always limited. Therefore, a systematic procedure is needed to design the optimal placement of measurement points. This paper presents a new HSE algorithm which is based on an optimal placement of measurement points using Genetic Algorithms (GAs). This HSE has been applied to the New Zealand AC Power System for the validation of the new HSE algorithm. The study results have indicated an economical and effective method for optimal placement of measurement points using GAs in the HSE.

• Proceedings of the KIEE Conference
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• 2003.07a
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• pp.92-94
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• 2003

The design of a measurement system to perform Harmonic State Estimation(HSE) is a very complex problem. In particular, the number of available harmonic instruments (Continuous Harmonic Analysis in Real Time : CHART) is always limited. Therefore, a systematic procedure is needed to design the optimal placement of measurement points. This paper presents an optimal algorithm of HSE which is based on an optimal placement of measurement points using Immune Algorithm (IAs). This HSE has been applied to power system for the validation of an optimal algorithm of HSE. The study results have indicated an economical and effective method for optimal placement of measurement points using IAs in the HSE.

• Proceedings of the KIEE Conference
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• summer
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• pp.286-288
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• 2004

The design of a measurement system to perform Harmonic State Estimation (HSE) is a very complex problem. In particular, the number of harmonic instruments available is always limited. Therefore, a systematic procedure is needed to design the optimal placement of measurement points. This paper presents a new HSE algorithm which is based on an optimal placement of measurement points using Genetic Algorithms (GAs). This HSE has been applied to the Simulation Test Power System for the validation of the new HSE algorithm. The study results have indicated an economical and effective method for optimal placement of measurement points using Genetic Algorithms (GAs) in the Harmonic State Estimation (HSE).

• Implantology
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• v.22 no.4
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• pp.210-218
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• 2018

Purpose: The purpose of this study was to investigate the validity and reproducibility of a method based on cone-beam computed tomography (CBCT) technology for the visualization and measurement of gingival soft-tissue dimensions. Material and Methods: A total of 66 selected points in soft-tissue of the ex vivo head of an adult pig were investigated in this study. For the measurement of radiographic thickness (RT), wet soft-tissue surfaces were lightly covered with barium sulfate powder using a powder spray. CBCT was taken and DICOM files were assessed for soft-tissue thickness measurement at reference points. A periodontal probe and a rubber stop were used for the measurement of trans-gingival probing thickness (TPT). After flap elevation, actual thickness of soft-tissue (actual thickness, AT) was measured. Correlation analysis and intraclass correlation coefficients analysis (ICC) were performed for AT, TPT, and RT. Results: All variables were distributed normally. Strong significant correlations of AT with RT and TPT values were found. The two ICC values between TPT vs. AT and RT vs. AT differed significantly. Conclusion: Our results indicated that correlation of RT was stronger than that of TPT with AT. We concluded that soft tissue measurement with CBCT could be a reliable method, compared to the trans-gingival probing measurement method.

• Proceedings of the KSME Conference
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• 2001.06e
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• pp.536-541
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• 2001

A high resolution digital cinematic Particle Image Velocimetry(PIV) has been developed. The system consists of a high speed CCD camera, a continuous Ar-ion laser and a computer with camera controller. To improve the spatial resolution, we adopt a Recursive Technique for velocity interrogation. At first, we obtain a velocity vector for a larger interrogation window size based on the conventional two-frame cross-correlation PIV analysis using the FFT algorithm. Based on the knowing velocity information, more spatially resolved velocity vectors are obtained in the next iteration step with smaller interrogation windows. The correct velocity vector at the first step is found to be critical, so we apply a Multiple Correlation Validation(MCV) technique in order to decrease the spurious vectors. The MCV technique turns out to improve SNR(Signal to Noise Ratio) of the correlation table. The developed cinematic PIV method has been applied to the measurement of the unsteady flow characteristics of a Rushton turbine mixer. A total of 3,245 instantaneous velocity vectors were successfully obtained with 4 ms time resolution. The acquired spatial resolution corresponds the performance of the conventional high resolution digital PIV system using a $1K{\times}1K$ CCD camera.

• Journal of Nutrition and Health
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• v.23 no.2
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• pp.93-107
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• 1990

The purposes of this investigation were to determine the validity of various methods (available anthropometric equations and near-infrared light interactance) for estimating body fat and to develop multiple regression equations for the prediction of body fat. Thirty-eight healthy males(age: 20.87$\pm$7.17 yrs) and 12 females(19.58$\pm$2.19 yrs) underwent hydrostatic weighing to determine body fat. Anthropometric measurements were taken of height, weight, nin skinfolds and thirteen circumferences. The results obtained are summarized as follows: 1) Relative body fat determined by underwater weighing was 12.08$\pm$5.21% for the males and 17.97$\pm$5.75% for the females. 2) Circumference and skin fold that had the highest correlation with the body fat were waist girth in males and females(r=0.60, r=0.96, respectively), and subscapular in males(r=0.68) and triceps in females(r=0.96). 3) Corss-validation of 18 selected equations on males revealed total errors ranging from 3.76% to 5.06%. Among these equations, M3(Pollock et al.) demonstrated the least total error. Total error of estimation by near-infrared(NIR) was less than that of available anthropometric measurement equations. The results of the cross-validation of 12 equations on females revealed that F3(Sloan et al.) was clearly superior in accuracy of prediction. 4) Correlational analyses showed that estimation of body fat by NIR measurement seemed to be more closely associated with body fat determined by underwater weighing in women than men, in older subjects than younger ones, and in fatter subjects than leaner ones.

• Journal of Korea Society of Industrial Information Systems
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• v.13 no.5
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• pp.44-54
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• 2008

The objective of this research is to develop a measurement instrument for service recovery quality in the Internet commerce setting. To this same end, Parasuraman et al.(2005) have devised a scale called E-RecS-QUAL, which we revised and supplemented to develop another instrument named eSR-Q. To guarantee its reliability and validity, this instrument went through the refinement and validation processes for internal consistency and construct validity in terms of convergent, discriminant, and nomological validity. Our final scale consists of four dimensions including responsiveness, compensation, contact, and apologies altogether with fourteen measures. Overall, this research deals with the related research background, the scale development and validation processes, its limitations, and future research directions.

• Korean Journal of Remote Sensing
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• v.21 no.5
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• pp.371-382
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• 2005

We present a processing system for the Atmospheric Infrared Sounder (AIRS) sounding suite onboard Aqua satellite. With its unprecedented 2378 channels in IR bands, AIRS aims at achieving the sounding accuracy of radiosonde (1 K in 1-km layer for temperature and $10\%$ in 2-km layer for humidity). The core of the processor is the International MODIS/AIRS Processing Package (IMAPP) that performs the geometric and radiometric correction for generation of Level 1 brightness temperature and Level 2 geophysical parameters retrieval. The processor can produce automatically from received raw data to Level 2 geophysical parameters. As we process the direct-broadcast data almost for the first time among the AIRS direct-broadcast community, a special attention is paid to understand and verify the Level 2 products. This processor includes sub-systems, that is, the near real time validation system which made the comparison results with in-situ measurement data, and standard digital information system which carry out the data format conversion into GRIdded Binary II (GRIB II) standard format to promote active data communication between meteorological societies. This processing system is planned to encourage the application of geophysical parameters observed by AIRS to research the aqua cycle in the Korean peninsula.

• Korean Journal of Remote Sensing
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• v.22 no.5
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• pp.389-396
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• 2006

Surface Solar Insolation is important for vegetation productivity, hydrology, crop growth, etc. In this study, Surface Solar Insolation is estimated using Multi-functional Transport Satellite (MTSAT-1R) in clear and cloudy conditions. For the Cloudy sky cases, the surface solar insolation is estimated by taking into account the cloud transmittance and multiple scattering between cloud and surface. This model integrated Kawamura's model and SMAC code computes surface solar insolation with a $5\;km{\times}5\;km$ spatial resolution in hourly basis. The daily value is derived from the available hourly Surface Solar Insolation, independently for every pixel. To validation, this study uses ground truth data recorded from the pyranometer installed by the Korea Meteorological Agency (KMA). The validation of estimated value is performed through a match-up with ground truth. Various match-up with ground truth. Various match-up window sizes are tested with $3{\times}3,\;5{\times}5,\;7{\times}7,\;9{\times}9,\;10{\times}10,\;11{\times}11,\;13{\times}pixels to define the spatial representativity of pyranometer measurement, and to consider drifting clouds from adjacent pixels across the ground station during the averaging interval of 1 hour are taken into account.

• Nuclear Engineering and Technology
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• v.52 no.12
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• pp.2717-2724
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• 2020

Silicon, especially silicon in the form of SiO₂, is a major component of rocks. Final spent fuel storages, which are being designed, are located in suitable rock formations in the Earth's crust. Reduction of the uncertainty of silicon neutron scattering and capture is needed; improved silicon evaluations have been recently produced by the ORNL/IAEA collaboration within the INDEN project. This paper deals with the nuclear data validation of that evaluation performed at the LR-0 reactor by means of critical experiments and measurement of reaction rates. Large amounts of silicon were used both as pure crystalline silicon and SiO₂ sand. The critical moderator level was measured for various core configurations. Reaction rates were determined in the largest core configuration. Simulations of the experimental setup were performed using the MCNP6.2 code. The obtained results show the improvement in silicon cross-sections in the INDEN evaluations compared to existing evaluations in major libraries. The new Thermal Scattering Law for SiO₂ published in ENDF/B-VIII.0 additionally reduces the discrepancy between calculation and experiments. However, an unphysical peak is visible in the neutron spectrum in SiO₂ obtained by calculation with the new Thermal Scattering Law.