• Journal of Electrical Engineering and Technology
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• v.7 no.6
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• pp.845-851
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• 2012

Power system loads have a significant impact on a system. Although it is difficult to precisely describe loads in a mathematical model, accurately modeling them is important for a system analysis. The traditional load modeling method is based on the load components of a bus. Recently, the load modeling method based on measurements from a system has been introduced and developed by researchers. The two major components of a load modeling problem are determining the mathematical model for the target system and estimating the parameters of the determined model. We use the composite load model, which has both static and dynamic load characteristics. The ZIP model and the induction motor model are used for the static and dynamic load models, respectively. In this work, we propose the measurement-based parameter estimation method for the composite load model. The test system and related measurements are obtained using transient security assessment tool(TSAT) simulation program and PSS/E. The parameter estimation is then verified using these measurements. Cases are tested and verified using the sample system and its related measurements.

• YAKHAK HOEJI
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• v.48 no.3
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• pp.171-176
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• 2004

This study was described for measuring clinically relevant levels of glucose in undiluted plasma and whole blood by near-infrared (NIR) spectroscopy. Result from an initial measurement of major blood components powder was over-lapped the absorption bands of glucose at 1500-1600 nm. However, the NIR data of blood components were clearly separated by principle component analysis (PCA) space. By the use of partial least squares (PLS) regression, glucose concentrations in undiluted plasma and whole blood could be determined with standard errors of prediction (SEP) of 15 mg/dl and 76 mg/dl, respectively. Although these blood components possessed strong absorption bands that overlapped with the absorption bands of glucose, successful calibration models could be carried out.

• Journal of the Korean Physical Society
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• v.73 no.11
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• pp.1657-1662
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• 2018

A null test method which relies on a computer generated hologram (CGH) is widely used to measure a large aspheric surface. For precise measurements of the surface shape of an aspheric optics, the CGH must precisely generate a wavefront that can fit on the ideal surface shape of the aspheric optics. If fabrication errors arise in the CGH, an unwanted wavefront will be generated and the measuring result will lack trustworthiness. Thus far, there has been limited research on wavefronts generated by CGH using only linear-type binary grating models. In this study, a theoretical error model of a circular-type zone plate, the most commonly used types for CGH patterns, is suggested. The proposed error model is checked by simulations and experiments.

• The Journal of the Korea Contents Association
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• v.12 no.10
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• pp.357-364
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• 2012

Dental scanner-based dental digital models have been developed that have the potential to replace conventional stone model. The aim of this study was examine the accuracy and reliability of measurements made on digital models. A master model with the prepared upper full arch tooth was used. Stone model(N=10) were produced from master model, and on the other hands, digital models were made with the white light scanner(Identica, korea). One examiner individually measured 6 parameters on the conventional model and the digital models on two occasions. The student's t-test for paired samples and intra-class correlation coefficient(ICC) were used for statistical analysis. At the intra-examiner reliability of measurement, ICC at the stone and digital models were 0.75 and 0.87. The mean difference between measurements made directly on the stone models and those made on the digital models was 0.11-0.23mm, and was statistically significant(P<0.05). These in vitro studies show that accuracy of the digital model is similar to that of the stone model. These results will have to be confirmed in further clinical studies.

• The Transactions of the Korean Institute of Power Electronics
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• v.9 no.3
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• pp.260-266
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• 2004

Because the EMI filter is mainly designed by trial and error method, it takes many times to reduce the conducted EMI noise in a power converter. Thus, a newly analytical design procedure is proposed to overcome the problem in this paper. High frequency models of each component are built, md, using the modeling circuits, the filter design is carried out applicable to each mode. Based on the accumulated database for practical components, and the measurement data of EUT with a standard filter, the filler design algorithm is presented. Finally, the validity of the Proposed models and design method is verified through the measurement results.

• Journal of the Korean Wood Science and Technology
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• v.44 no.6
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• pp.864-871
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• 2016

This study was conducted to compare and analyze gross calorific values from measurement methods of lignocellulosic biomass and calculation data from calorific value prediction models based on the elemental content. The deviation of Liriodendron tulipifera (LT) and Populus euramericana (PE) was shown 7.7 cal/g and 7.4 cal/g respectively in palletization method, which are within repeatability limit 28.8 cal/g of ISO FDIS 18125. In the case of Thailand charcoal (TC), nontreatment method and palletization method was satisfied with repeatability limit as 22.8 cal/g and 8.8 cal/g respectively. Seowon charcoal (SC) was shown deviation of 11.4 cal/g in nontreatment method, because the density and chemical affinity of sample increases as the carbon content increases from heat treatment at high temperature in the case of TC and SC. In addition, after applying the elemental content of each of these samples to the calorific value prediction models, the study found that Model Equation (3) was relatively consistent with measured calorific values of all these lignocellulosic biomass. Thus, study about the correlation between the density and size of particle should be conducted in order to select the measurement method for a wide range of solid biofuels in the future.

• Journal of the Korean Operations Research and Management Science Society
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• v.42 no.2
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• pp.35-48
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• 2017

As the technology convergence paradigm emerges, the need for "CIA techniques" to analyze the mutual effects of technology is increasing. However, since the CIA input parameter estimation is difficult, the present study suggests a "CIA input parameter setting model" to alleviate the difficulty of CIA input parameter estimation. This paper is focused on the difference of measurement difficulty by each scale which expert's estimation behavior was defined as measurement activity quantifying the judgment of future technology. Therefore, this model is designed to estimate the input variable as a sequence or isometric scale that is relatively easy to measure, and then converts it into a probability value. The input parameter setting model of the CIA technique consists of three sub-models : 'probability value derivation model', 'influence estimation model', and 'impact value calculation model', in order to develop a series of models the Thurstone V model, Regression Analysis, etc has been used.

• Journal of Korean society of Dental Hygiene
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• v.13 no.2
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• pp.361-368
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• 2013

Objectives : The purpose of this in vitro study was to evaluate the effect of firing cycles on the marginal and internal fit of metal ceramic crown. Methods : Ten same cases of stone models (abutment teeth 11) were manufactured. Ten cobalt-chrome cores were made per each models and the marginal and internal fit was evaluated through a silicone replica technique. The marginal and internal fit of specimens was measured twice. The first measurement was done after manufacturing cobalt-chrome alloy core and the second measurement was done after porcelain firing. T-test of paired sample for statistical analysis was executed with SPSS 12.0K for Windows (${\alpha}$=0.05). Results : Mean(SD) marginal and internal fit were 77.1(23.3) ${\mu}m$ for the cobalt-chrome alloy core group and 84.4(21.9) ${\mu}m$ for the metal-ceramic crown group. They were statistically significant differences between groups for marginal and internal fit (p<.05). Conclusions : All metal ceramic crowns showed marginal and internal fit ranged within the current clinical recommendations.

• Bulletin of the Korean Space Science Society
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• 2009.10a
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• pp.49.4-50
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• 2009

We report stray light modeling and analysis results for the current and proposed next generation ocean color imagers with Sun and the target area around Korean penninsular as viewed from geostationary orbit. The imagers used in this study are GOCI of 140mm in diameter and a proposed next generation GOCI (GOCI-II) of about 300mm in diameter. First, we built complete GOCI and GOCI-II 3D optical system models with the realistic surface characteristics. These optical models were incorporated into the in-house built Intergrated Ray Tracing (IRT) algorithm, connecting the Sun, the measurement target area and the instruments via single ray tracing computation for radiative transfer and scattering. The stray light level was then estimated for possible orbital configurations for science measurement and in-orbit calibration operation. The simulation details, results and their implications are presented.

• Journal of the Korea Safety Management & Science
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• v.7 no.4
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• pp.141-163
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• 2005

The international SPICE (Software Process Improvement and Capability determination) Project ISO/IEC 15504(SPICE : Software Process Improvement and Capability determination) is an emerging International Standard on SPA(Software Process Assessment). A prime motivation for developing this standard has been the perceived need for an internationally recognized software process assessment framework that pulls together the existing public and proprietary models and methods. A SPICE assessment can be considered as one of representative SPA model since assessors assign ratings to indicators and metrics to measure the capability of software process. But this models doesn't provide a systematic measurement procedures and dynamic method for SPI(Software Process Improvement). Through the evaluation of SPICE is capable of providing a substantiated basis for using the notion of capability, as well as providing information for nacessary improvements to the standard using 6sigma process. As a result, this paper propose a measurement procedure and guidelines for application of 6sigma process to guarantee the reliability in SPI and suggest the structure to support SPI on overall organization.