• Honam Mathematical Journal
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• v.29 no.1
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• pp.55-60
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• 2007

Given operators X and Y acting on a Hilbert space $\cal{H}$, an interpolating operator is a bounded operator A such that AX = Y. In this article, we showed the following : Let $\cal{L}$ be a subspace lattice acting on a Hilbert space $\cal{H}$ and let X and Y be operators in $\cal{B}(\cal{H})$. Let P be the projection onto $\bar{rangeX}$. If FE = EF for every $E\in\cal{L}$, then the following are equivalent: (1) $sup\{{{\parallel}E^{\perp}Yf\parallel\atop \parallel{E}^{\perp}Xf\parallel}\;:\;f{\in}\cal{H},\;E\in\cal{L}\}\$ < $\infty$, $\bar{range\;Y}\subset\bar{range\;X}$, and < Xf, Yg >=< Yf,Xg > for any f and g in $\cal{H}$. (2) There exists a self-adjoint operator A in Alg$\cal{L}$ such that AX = Y.

• Journal of the Korea Society of Computer and Information
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• v.21 no.4
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• pp.97-106
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• 2016

The aim of this study is to measure the degrees of emotional labor and to empirically analyze how emotional labor affects individual's stress coping style and psychological burnout. The results were as follows. First, the call center employees were actually experiencing emotional labor and it was shown that the deep acting was higher than the surface acting. Second, the degree of experiencing stress coping style and psychological burnout appeared differently depending on the socio-economic variables of the employee. Third, despite the differences in the direction, there is a correlation between emotional labor, stress coping style, and psychological burnout. Fourth, the characteristics of the employees and emotional labor clearly affected stress coping style and psychological burnout. Therefore, companies will have to provide various psychological treatments and training programs for call center employees, and a change in social awareness, where people take the service industry workers' kindness for granted, is required as well.

• Journal of Industrial Technology
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• v.24 no.B
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• pp.29-36
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• 2004

The wind and wind-induced dynamic wind pressures fluctuate irregularly according to time and space. In this study, the proper orthogonal decomposition(POD) technique is applied to wind pressures acting on a tall tower model, and the following results are found: the along-wind and across-wind forces can be reconstructed by only four dominant POD modes, and the reconstructed errors are 4.71% and 22%, respectively for across-wind and along-wind directions. The physical meanings for dominant modes are also presented in the paper. The POD analysis can compress complex wind pressure data only by a few dominant modes and interpret spatio-temporal characteristics of wind pressure by novel way while existing statistical methods do not have such benefits.

• Progress in Superconductivity and Cryogenics
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• v.15 no.3
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• pp.13-19
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• 2013

Superconducting field coils using a high-temperature superconducting (HTS) wires with high current density generate high magnetic field of 2 to 5 [T] and electromagnetic force (Lorentz force) acting on the superconducting field coils also become a very strong from the point of view of a mechanical characteristics. Because mechanical stress caused by these powerful electromagnetic force is one of the factors which worsens the critical current performance and structural characteristics of HTS wire, the mechanical stress analysis should be performed when designing the superconducting field coils. In this paper, as part of structural design of superconducting field coils for 17 MW class superconducting ship propulsion motor, mechanical stress acting on the superconducting field coils was analyzed and structural safety was also determined by the coupling analysis system that is consists of commercial electromagnetic field analysis program and structural analysis program.

• Genomics & Informatics
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• v.10 no.4
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• pp.234-238
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• 2012

Genetic epidemiology studies have established that the natural variation of gene expression profiles is heritable and has genetic bases. A number of proximal and remote DNA variations, known as expression quantitative trait loci (eQTLs), that are associated with the expression phenotypes have been identified, first in Epstein-Barr virus-transformed lymphoblastoid cell lines and later expanded to other cell and tissue types. Integration of the eQTL information and the network analysis of transcription modules may lead to a better understanding of gene expression regulation. As these network modules have relevance to biological or disease pathways, these findings may be useful in predicting disease susceptibility.

• Proceedings of the Korean Geotechical Society Conference
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• 2004.03b
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• pp.952-957
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• 2004

Cut and Cover Method is generally used in shallow tunnels and tunnel entrances with thin soil cover. In this type of cons0truction, backfilling is considered to be the most important process. In this process even though the backfill material is thoroughly compacted, compaction and self-weight due to vehicular vibration and pressure exerted by the soil cause the backfill material to undergo self-compression which leads to settlement. The settlement of the backfill material subjects the tunnel lining under excessive earth pressure which cause cracking and deformation. In the model test performed installation of geotextile on the sides and top of the tunnel was able to reduce the earth pressure acting on the tunnel lining.

• Journal of Ocean Engineering and Technology
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• v.20 no.6 s.73
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• pp.75-81
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• 2006

In this study, the dynamic response of the umbilical cable in a deep-water unmanned underwater vehicle system was analyzed. In order to analyze the forces acting on the cable, the launcher and umbilical cable were modeled by the simple 1-D mass-spring system. Damping and dynamic analysis was carried out by a direct time integration scheme using the $Newmark-{\beta}$ method with inverse iteration procedure, considering the nonlinear drag forces acting on the launcher. The obtained results of the present study can be used for the design of connecting the structure of the launcher and cable of the UUV system.

• 유체기계공업학회:학술대회논문집
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• 2006.08a
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• pp.437-440
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• 2006

Particle suspension is frequently observed in many natural flows such as in the atmosphere and the ocean as well as in various engineering flows. Recently, airborne micro or nano-scale particles in atmosphere attract much attention from environmental society since small particle cause serious environmental problems in the industrialized areas. Also, the characteristics of such heavy particles' behavior is quite different from its fluid particles because the inertia force and buoyance force acting on the heavy particles are different than those acting on fluid particles. Therefore, our studies is to investigate the characteristics of the behavior of heavy particles considering the inertia effect with or without gravity effect, but do not consider modification of turbulence by the particles, that is one-way interaction. We carried out direct numerical simulation of isotropic turbulence with particles under the Stokes drag assumption for a spherical particle. These results can be used in the development of a stochastic model for predicting particle's behavior.

• 제어로봇시스템학회:학술대회논문집
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• 1991.10a
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• pp.962-967
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• 1991

A counter balance valve is used as one part of hydraulic motor brake system. The function of this valve is to protect over-run or free falling of inertia load. But occasionally the brake system with counter balance valve makes some undesirable problems such as pressure surges or vibrations. In this study, for the purpose of easy estimation about dynamic characteristics of hydraulic system including counter balance valve, precise formulation describing fluid dynamics and valve dynamics under various boundary conditions were made. Dynamic characteristics were analysed by numerical integration using Runge-Kutta method, because the equations in this circuit with counter balance valve contain various nonlinear terms. Propriety of this analysis method is verified by experiment. For the purpose of obtaining fundamental data for preventing instability, this study experimented the effects of the spool taper, spring constant, cylindrical choke. And we developed double acting brake system integrated counter balance valve.

• Honam Mathematical Journal
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• v.30 no.4
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• pp.685-691
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• 2008

Given operators $X_i$ and $Y_i$ (i = 1, 2, ${\cdots}$, n) acting on a Hilbert space $\mathcal{H}$, an interpolating operator is a bounded operator A acting on $\mathcal{H}$ such that $AX_i$ = $Y_i$ for i= 1, 2, ${\cdots}$, n. In this article, if the range of $X_k$ is dense in H for a certain k in {1, 2, ${\cdots}$, n), then the following are equivalent: (1) There exists a self-adjoint operator A in $\mathcal{B}(\mathcal{H})$ stich that $AX_i$ = $Y_i$ for I = 1, 2, ${\cdots}$, n. (2) $sup\{{\frac{{\parallel}{\sum}^n_{i=1}Y_if_i{\parallel}}{{\parallel}{\sum}^n_{i=1}X_if_i{\parallel}}:f_i{\in}H}\}$ < ${\infty}$ and < $X_kf,Y_kg$ >=< $Y_kf,X_kg$> for all f, g in $\mathcal{H}$.