• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.8 s.179
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• pp.2143-2150
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• 2000

An MRC(Magneto-rheological Clutch) has a great potential of application because of its good transmissibility, little wear-out and fast response to electrical control signal. Though many MRCs have been developed for years, there has not been an research on the method to predict the performance of MRC except the simplified mathematical models. But the simplified mathematical models do not fit well since their performance has close relations with shapes of clutches and viscosity distribution throughout the fluids caused by applied magnetic fields. in this study, the CFD and FEM analyses were applied to various shape of MRC and the methods were examined in experiments.

• Steel and Composite Structures
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• v.3 no.5
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• pp.349-369
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• 2003

The paper concerns the modelling of rigid and semi-rigid steel-concrete composite joints under monotonic loading through use of the Abaqus program, a widespread finite element code. By comparing numerical and experimental results obtained on cruciform tests, it is shown that the proposed modelling allows a good fit of the global joint response in terms of moment-rotation law. Even the local response in terms of stresses and strains is adequately predicted. Hence, this numerical approach may represent a useful tool for attaining a better understanding of experimental results. It may also be used to perform parametric analyses and to calibrate simplified mechanical models for practical applications.

• Earthquakes and Structures
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• v.15 no.2
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• pp.165-178
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• 2018

The aim of this study is to investigate the efficiency of using threaded rods and steel profiles to produce a steel confining system for rehabilitation of damaged concrete corbels for the first time in literature. Some of the specimens were repaired by crack repair epoxy before being confined for further enhancement. A total of 19 two sided damaged corbels were used in the study with different mechanical properties and parameters but similar dimensions. The differences were in rehabilitation style, shear span, fiber percentage, reinforcement steel diameter, and concrete strength. The rehabilitated specimens were loaded with vertical load until failure. Four different configurations were used in the investigation. Test results show that the proposed rehabilitation technique is effective to enhance the load capacity of the corbels and to improve their ductility. Moreover, new formulations were proposed to calculate the load capacity of the rehabilitated corbels. A good fit was observed between numerical and experimental results.

• Bulletin of the Korean Chemical Society
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• v.32 no.7
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• pp.2433-2442
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• 2011

The three dimensional quantitative structure activity relationship (3D QSAR) models were developed using Comparative molecular field analysis (CoMFA), comparative molecular similarity indices analysis (CoMSIA) and docking studies. The fit of Quinazolinone antifolates inside the active site of modeled bovine dihydrofolate reductase (DHFR) was assessed. Both ligand based (LB) and receptor based (RB) QSAR models were generated, these models showed good internal and external statistical reliability that is evident from the $q^2_{loo}$, $r^2_{ncv}$ and $r^2_{pred}$. The identified key features enabled us to design new Quinazolinone analogues as DHFR inhibitors. This study is a building bridge between docking studies of homology modeled bovine DHFR protein as well as ligand and target based 3D QSAR techniques of CoMFA and CoMSIA approaches.

• Textile Coloration and Finishing
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• v.30 no.3
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• pp.159-167
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• 2018

Here we designed and synthesized new zinc phthalocyanines and structures were fully confirmed by spectral and elemental analysis. All phthalocyanines have a very good solubility in industrial solvents like chloroform, dichloromethane, dimethyl sulfoxide, N,N-dimethyl formamide, propylene glycol monomethyl ether acetate (PGMEA), acetone, tetrahydrofuran and acetonitrile. UV-Visible absorption and transmittance in PGMEA showed that these dyes have suitable spectral properties for LCD color filters. By Triton X surfactant study, we confirmed that these dyes are not showing any aggregation in PGMEA. We dissolved the all phthalocyanines in LCD fabricating solvent (PGMEA), and all phthalocyanines showed more than 8 wt% of solubility. Finally, all of these results concluded that PCK1, PCK2 and PCK3 are fit for LCD green color filter.

• Proceedings of the Korea Concrete Institute Conference
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• 2003.05a
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• pp.311-314
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• 2003

Concrete structures such as bridge, pavement, airfield, and offshore structure are normally subjected to repeated load. This paper proposes a failure probability models of concrete subjected to split tension repeated-loads, based on experimental results. The fatigue tests were performed at the stress ratio of 0.1, the loading shape of sine, the frequency of 20Hz, and the stress levels of 90, 80 and 70%. The fatigue test specimen was 150mm in diameter and 75mm in thickness. The fatigue analysis did not include which exceeded 0.9 of statistical coefficient of determination values or did not failure at 2$\times$$10^6$ cycles. The graphical method, the moment method, and maximum likelihood estimation method were used to obtain Weibull distribution parameters. The goodness-of-fit test by Kolmogorov-Smirnov test was acceptable 5% level of significance. As a result, the proposed failure probability model based on the two-parameter($\alpha and \mu$) Weibull distribution was good enough to estimate accurately the fatigue life subjected to tension mode.

• Journal of the Korean Home Economics Association
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• v.40 no.5
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• pp.133-146
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• 2002

The purpose of this study was to verify a Structural Equation Model that constructed the causations among the leisure resources, health perception, leisure attitude, leisure satisfaction and the quality of life in the elderly. For the purpose, 208 elderly who were over sixty years old and inhabited in Seoul were given questionnaires. Questionnaires were distributed by means of a 1:1 personal interview method. A Measurement model and a structural equation model estimates by Maximum Likelihood method(ML method) utilizing LISREL 8.51 ver. The major results are summarized as follows: 1) A Goodness of fit is good of structural equation model presented in the study. 2) The higher their leisure resource is, the higher health perception is, the higher leisure attitude is the more leisure satisfaction. 3) The important valuable factor which affected the quality of life in the elderly was the leisure satisfaction. It showed powerfully if the elderly participate enjoyment, self-development and positive leisure activity, their leisure satisfaction would increase, consequently the Quality of life would be improved.

• Transactions of the Korean Society of Mechanical Engineers
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• v.19 no.7
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• pp.1770-1779
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• 1995

A combined convective heat transfer study for non-Newtonian fluids was experimentally performed in uniformly heated horizontal tubes with laminar flow in the thermal entry region. Velocity profiles were fully developed at the entrance of the heated sections in the tubes. Aqueous solutions of sodium carboxymethylcellulose(CMC ) were used; their behavior showed a reasonably good fit into the power-law model, .tau.=K.gamma.$^{n}$ . The test sections were made of copper with inside diameters of 3.23 cm and 5.042 cm and lengths of approximately 300 cm. Most experimental runs displayed noticeable secondary flows caused by buoyancy ; when present, secondary flows caused significant increase in the rate of heat transfer over the purely forced-convection case. A correlation, which relates the rate of heat transfer for flows with temperature-dependent properties, free convection effects, and non-newtonian effects, was suggested.

• Knowledge Management Research
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• v.8 no.1
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• pp.1-14
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• 2007

This paper is an exploratory study providing critical research issues in knowledge management strategy, process operations, and knowledge management system design and control in mass customization. The firms implementing mass customization provide good cases adopting recent changes in business environment including increased diversity and variability of customer needs, fast development of related technologies, and increase of the necessity of knowledge management. In this study, required knowledge management characteristics are investigated and future research issues are suggested for successful implementations of knowledge management. Research issues are extracted from the context of strategy, process, and information system for the purpose of practical adaptation and the types of mass customization are emphasized as a mediating element for fit and consistency between firms' corporate strategy and knowledge management characteristics.

• Communications for Statistical Applications and Methods
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• v.27 no.5
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• pp.501-510
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• 2020

Mardia (Biometrika, 57, 519-530, 1970) defined measures of multivariate skewness and kurtosis. Based on these measures, omnibus test statistics of multivariate normality are proposed using normalizing transformations. The transformations we consider are normal approximation and a Wilson-Hilferty transformation. The normalizing transformation proposed by Enomoto et al. (Communications in Statistics-Simulation and Computation, 49, 684-698, 2019) for the Mardia's kurtosis is also considered. A comparison of power is conducted by a simulation study. As a result, sum of squares of the normal approximation to the Mardia's skewness and the Enomoto's normalizing transformation to the Mardia's kurtosis seems to have relatively good power over the alternatives that are considered.