• Transactions of the Korean Society of Pressure Vessels and Piping
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• v.12 no.1
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• pp.30-40
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• 2016

The paper investigates the previous studies about welding residual stresses in nuclear components. First, various residual stress measurement methods are reviewed in applicability. Second a finite element welding residual stress analysis technique, which was developed from the viewpoint of FFS (Fitness-For-Service) assessment, is explained. Third, characteristics of the welding residual stresses on J-groove welds and butt welds were presented via investigating the previous studies. Last, engineering formulae for residual stresses in the FFS assessment codes such as R6 and API 579/ASME FFS-1 Code is summarized.

• Particle and aerosol research
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• v.9 no.1
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• pp.1-6
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• 2013

New evaluation method for the particle size and morphology via change of ground particle during a grinding process was investigated. The grinding experiments were carried by a planetary ball mill. The relationship between the particle outline of the scanning electron microscopy photograph and measurement line, the measurement contact number was evaluated. The value of contact number decreased with the increase in the particle size of the ground sample, and varied with the experimental conditions. The value of contact number, which is related to the particle size of the raw sample, changed at the various experimental conditions.

• The KSFM Journal of Fluid Machinery
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• v.12 no.4
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• pp.54-62
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• 2009

The feedwater heaters are Critical components in a nuclear power plant. As the operation years of heaters go by, the maintenance costs required for continuous operation increase. When the carbon steel components in nuclear make contact with running fluid, the wall thinning caused by FAC (flow accelerated corrosion) can be generated. Local wall thinning is inevitable at the area around wet steam entrance to be attacked due to the long term operation. Sometimes the shell with thinned wall is eventually ruptured. To identify the relationship between the local wall thinning and fluid behavior of the feedwater heater, the practical data of a plant, which were based on ultrasonic thickness measurement tests, were analyzed and CFD(Computed Fluid Dynamics) analyses were performed.

• Journal of Information Technology Applications and Management
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• v.12 no.3
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• pp.111-128
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• 2005

This paper examines the validity of the newly developed IT consulting SERVQUAL measurement tool. In an attempt to measure Ire IS customers' expectations and perceived quality of the services they received, the researchers developed a diagnostic tool of SERVQUAL based on the solid theoretical background, which can specifically be applied to the IT consulting service sector. This on-going research so far, has been applied to six (6) different organizations that have received IT consulting services over the past years. From the preliminary data collected, the correlation and the factor analyses were conducted to understand the underlying concept and refinement of the measurement tool. Although the correlation analysis showed a little tendency of collinearity among some of the variables, all showed sound relationship of the proposed hypotheses. The exploratory factor analytic approach was chosen because it does not set any priori constraints on the estimation of components or the number of components to be extracted. The number of different factor solutions was extracted and tested to see which solution represents better grouping of the variables. The Crombach's Alpha was computed on different combinations of the factor solutions to ensure validity. The results show 8-dimensional IT consulting SERVQUAL measures which they are, assurance, knowledge & skill, customer relationship, support, empathy, process management, expertise, and education, seem more appropriate than the originally proposed 6 dimensions. The study approach was non-experimental cross-sectional research design. The longitudinal design of follow-up studies to periodically revise and refine current measure is strongly recommended for fine tuning of the tool.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.35 no.6
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• pp.573-580
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• 2017

Precise stochastic modeling for GPS measurements is one of key factors in adjustment computations for GPS positioning. To analyze the GPS measurement errors, Minimum Norm Quadratic Unbiased Estimators(MINQUE) approach is used in this study to estimate the variance components for measurement types with short-baseline GPS positioning model. The results showed the magnitudes of measurement errors for C1, P2, L1, L2 are 22.3cm, 27.6cm, 2.5mm, 2.2mm, respectively. To reduce the memory usage and computational burden, variance components are also estimated on epoch-by-epoch basis. The results showed that there exists slight differences between the solutions. However, epoch-by-epoch analysis may also be used for most of GPS applications considering the magnitudes of the differences.

• Journal of Biomedical Engineering Research
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• v.22 no.6
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• pp.497-502
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• 2001

Influence of other blond components on measuring glucose concentration was analyzed B)food phantom containing five major components was made. The prediction model was developed based on the measurement of absorption spectra including the first overtone glucose band, i.e.. 1500 ∼ 1850 nm. The concentrations were Predicted using the Partial least squares regression. Factor analysis based on Design of Experiment was Performed to study the influence of other components in predicting glucose concentration. Triglyceride does not influence. Albumin and globulin haute minor effects. However, hemoglobin showed substantial response and the compensation of hemoglobin concentration appears to be required for the model of glucose measurement.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.6
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• pp.1079-1085
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• 2011

To supply electrical power with high quality, the power system must be optimized in many ways such as planning, control and management. In order to optimize the power system, the analysis of the power system is necessary. The elements of the power system require an accurate model to analysis of the power system. The components of the power systems such as generators, transformers and transmission lines have been studied and researched a lot in their modeling and very sophisticated models have been proposed. However, in case of load in-depth studies on the exact model are required. In this paper, measurement-based load modeling method using real-time measured data is proposed in various methods to reflect the characteristics of the load. To prove the validity of the proposed method, PSCAD/EMTDC program is used to configure the power system and measurement data according to the various failures are used to study on load modeling.

• ETRI Journal
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• v.31 no.6
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• pp.675-679
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• 2009

$Ti_xSi_{1-x}O_y$ (TSO) thin films are fabricated using plasma-enhanced atomic layer deposition. The Ti content in the TSO films is controlled by adjusting the sub-cycle ratio of $TiO_2$ and $SiO_2$. The refractive indices of $SiO_2$ and $TiO_2$ are 1.4 and 2.4, respectively. Hence, tailoring of the refractivity indices from 1.4 to 2.4 is feasible. The controllability of the refractive index and film thickness enables application of an antireflection coating layer to TSO films for use as a thin film solar cell. The TSO coating layer on an Si wafer dramatically reduces reflectivity compared to a bare Si wafer. In the measurement of the current-voltage characteristics, a nonlinear coefficient of 13.6 is obtained in the TSO films.

• The Transactions of the Korea Information Processing Society
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• v.6 no.3
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• pp.580-588
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• 1999

The reuse of software components from existing software system enhances productivity and reliability, decreases the cost of production in software development. The extraction of software components with high reusability from existing software system is very important in software reuse. The reuse of a class is classified into white-box reuse to reuse with modification and black-box reuse to reuse without modification. A class has the property of procedural language and object-oriented language. Therefore, it must measure reusability in consideration of two properties. In black-box reuse, independence of class is important quality. It can quantify through information hiding, coupling between objects, cohesion, etc. In white-box reuse, modification is the best important quality. It can quality through class complexity, coupling, cohesion, documentation, etc. We propose a new model for measurement of class reusability and the measure criteria in object-oriented program. A class that is measured by proposed model can judge whether the reuse with modification has the advantage or the reuse without modification has the advantage.

• Korean Journal of Veterinary Research
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• v.47 no.2
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• pp.139-145
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• 2007

Measurement uncertainty could play an important role in the assessment of test results in laboratories and industries. We investigated measurement uncertainties possibly included in determination of flubendazole, a benzimidazole anthelmintic, in pork by HPLC. The concentration of flubendazole was 62.69 ng/g in a sample of pork. Uncertainty was estimated in the analytical procedure of flubendazole. A model equation was made for determination of flubendazole in pork. The four uncertainty components such as weight of sample, volume of sample, calibration curve, and recovery were selected to estimate measurement uncertainties. Standard uncertainty was calculated for each component and all the standard uncertainties were combined. The combined standard uncertainty was expanded to a sample population as an expanded uncertainty. The expanded uncertainty was calculated using k value on Student's t-table and effective degrees of freedom from Welch-Satterthwaite formula. The expanded uncertainty was calculated as 3.45 with the combined standard uncertainty, 1.584 6 and the k value, 2.18. The final expression can be ($62.69{\pm}3.45$) ng/g (confidence level 95%, k = 2.18). The uncertainty value might be estimated differently depending on the selection of the uncertainty components. It is difficult to estimate all the uncertainty factors. Therefore, it is better to take several big effecting components instead of many small effecting components.