• Journal of Surface Science and Engineering
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• v.40 no.5
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• pp.234-240
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• 2007

As a reactor coolant pump (RCP) is operated in the nuclear power system for a long time, so its surface is continuously contaminated by radioactive scales. In order to maintain for RCP internals, a special chemical decontamination process should be used to reduce the radiation from the RCP surface. In this study, applicable possibility in chemical decontamination for RCP was investigated for the various stainless steels. The stainless steel (STS) 304 showed the best electrochemical properties for corrosion resistance and the lowest weight loss ratio in chemical decontamination process model 3-1 than other materials. However, the pitting corrosion was generated in both STS 415 and STS 431 with the increasing numbers of cycle. The intergranular corrosion in STS 415 was sporadically observed. The sizes of their pitting corrosion were also increased with increasing cycle numbers.

• Journal of the Korean earth science society
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• v.35 no.5
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• pp.333-341
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• 2014

A new set of basis functions was constructed using the Rossby-Haurwitz waves, which are the eigenfunctions of nondivergent barotropic vorticity equations on the sphere. The basis functions were designed to be non-separable, that is, not factored into functions of either the longitude or the latitude. Due to this property, the nodal lines of the functions are aligned neither along with the meridian nor the parallel. The basis functions can be categorized into groups of which members have the same degree or the total wavenumber-like index on the sphere. The orthonormality of the basis functions were found to be close to the machine roundoffs, giving the error of $O(10^{-15})$ or $O(10^{-16})$ for double-precision computation (64 bit arithmetic). It was demonstrated through time-stepping procedure that the basis functions were also the eigenfunctions of the non-divergent barotropic vorticity equations. The projection of the basis functions was carried out onto the low-resolution geopotential field of Gaussian bell, and compared with the theory. The same projections were performed for the observed atmospheric-geopotential height field of 500 hPa surface to demonstrate decomposition into the fields that contain disturbance of certain range of horizontal scales. The usefulness of the new basis functions was thus addressed for application to the eigenmode analysis of the atmospheric motions on the global domain.

• Publications of The Korean Astronomical Society
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• v.30 no.2
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• pp.269-270
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• 2015

We carried out near-IR photometric and optical spectroscopic observations of V582 Aur, which is a FU Orionis type object, to investigate any periodic and/or aperiodic variations. We obtained light curves on the scale of a night and a year, in J, H and Ks bands with KASINICS (KASI Near Infrared Camera System) attached to the BOAO (Bohyun-san Optical Astronomy Observatory) 1.8-m reflector in Youngcheon, South Korea and examined photometric variations on the two time scales. So far we have not found any periodic brightness variations on the scale of a night. On the other hand, we have found that there seems to be a periodic brightness variation with a period of approximately 45 days. In addition, high-resolution optical spectroscopic observations of V582 Aur were performed from February 2013 to May 2014 with the high-resolution echelle spectrograph BOES attached to the BOAO 1.8-m reflector. We analyzed several spectral lines to understand the physical state of V582 Aur. The P Cyg profiles are clearly shown in the $H{\alpha}$ line and Na I D line.

• The Research Journal of the Costume Culture
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• v.14 no.6
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• pp.1004-1014
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• 2006

The purposes of this study is to investigate the present condition of nurses' uniform design and to categorize the image of nurses' uniform design. To investigate the nurses' uniform design, total 241 data were collected from the pictures of nurses who work for private hospital and semi-general hospital in Deajeon and Seoul city and Chungnam province and the pictures of uniform for nurses in general hospital presented at nurses' uniform company web sites. This data was evaluated by 3 major garment characteristics, yin/yang, casual/professional, and lightness/ darkness-were used as criteria for categorizing the image of nurses' uniform design. Focus group consisting of 10 experts majored in Clothing and Textiles were evaluated by 7 point Likert type scales. Nurses' uniform design at the present time showed equal distribution in terms of yin/yang and casual/professional. However, in terms of lightness/darkness, nurses' uniform design were partial to light image. Therefore, dark image, specially dark and masculine image in nurses' uniform design were very rare. Nurses' uniform design had some differences by type of hospital, department, and geographical area. The most important meaning from the result through this study was that the nurse uniforms were classified into groups according to the present condition of nurses' uniform design.

• The Korean Journal of Applied Statistics
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• v.18 no.3
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• pp.597-606
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• 2005

The nonresponse in sample survey causes a problem when it comes time to analyze dataset in public-use files where the user has only complete-data methods available and has limited information about the reasons for nonresponse. Recently imputation for nonresponse is becoming a standard approach for handling nonresponse and various imputation methods have been devised . However, most imputation methods concern with continuous traits while many interesting features are measured by binary or ordered categorical scales in sample survey. In this note. an imputation method for ignorable nonresponse in binary or ordered categorical traits is considered.

• Journal of the Korean Vacuum Society
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• v.12 no.S1
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• pp.113-115
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• 2003

We investigate transmission of light in nanoscale structures. We present spatial and temporal domain measurements of the dephasing of surface plasmon excitations in metal films with periodic nano-hole arrays. By probing coherent spatial SP propagation lengths of a few f1. $\mu$m and an ultrafast decay of the SP polarization on a 10 fs timescale, we demonstrate that the SP transmission peaks are homogeneously broadened by the SP radiative lifetime. The pronounced wavelength and hole size dependence of the dephasing rate shows that the microscopic origin of the conversion of SP into light is a Rayleigh-like scattering by the periodic hole array. We have experimentally studied the dephasing of surface plasmon excitations in metallic nano-hole arrays. By relating nanoscopic SP propagation, ultrafast light transmission and optical spectra, we demonstrate that the transmission spectra of these plasmonic bandgap structures are homogeneously broadened. The spectral line shape and dephasing time are dominated by Rayleigh scattering of SP into light and can varied over a wide range by controlling the resonance energy and/or hole radius. This opens the way towards designing SP nano-optic devices and spatially and spectrally tailoring light -matter interactions on nanometer length scales.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2002.11a
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• pp.333-337
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• 2002

All the outdoor and indoor spaces are connected with each other. The human being moves toward those spaces and experiences temperature fluctuation between the natural and artificial temperature. We conducted an experiment which subjects are the college students wearing the data logger in urban life, and measured 24 hours' exposed temperature and thermal comfort in summer. Results were as follows. 1. Most subjects get weather information(84.6％). Fashion(46.2％) and weather (30.8％) are the reasons to select clothes. They spend their time in indoor environment for 84.92％ hours of a day and have an air-conditioner(61.5％) in their houses. 2. Exposed temperature fluctuation were from 33.8$^{\circ}C$ to 15.6$^{\circ}C$. The median value of experienced temperature were 26-27$^{\circ}C$ and average temperature was 26.3$^{\circ}C$. Subjects experienced cold shock of 3.96 times in a day and 67.21％ of all evaluated thermal comfort in the range of -1 and 1 by ASHRAE 7 Category Scales. Artificial environment which connected with outside let people experienced temperature fluctuation in wide range.

• Journal of Families and Better Life
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• v.28 no.6
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• pp.71-80
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• 2010

This study investigates the infant's cognitive and motor development, mother's parenting knowledge, and father's participation of child-rearing according to demographic variables and child-care related variables. A total of 112 infants aged from 11.5 months to 12.5 months old were tested by Korean Bayley Scales of Infant Development II; in addition, their mothers participated in the survey. The major results were as follows: First, among five areas of parenting knowledge, mothers attained the highest score on socio-emotional development and the lowest on cognitive and language development. Second, fathers participation in child-rearing were related to their income and the time to start child-care center. Third, the development of infants were positively associated with the father's participation in child-rearing. The implications for designing child-care policy and parent education program were discussed.

• Journal of Communications and Networks
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• v.18 no.4
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• pp.567-579
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• 2016

Several energy saving techniques in cellular wireless networks such as active base station (BS) selection, transmit power budget adaptation and user association have been studied independently or only part of these aspects have been considered together in literature. In this paper, we jointly tackle these three problems and propose an integrated framework, called dynamic cell reconfiguration (DCR). It manages three techniques operating on different time scales for ultimate energy conservation while guaranteeing the quality of service (QoS) level of users. Extensive simulations under various configurations, including the real dataset of BS topology and utilization, demonstrate that the proposed DCR can achieve the performance close to an optimal exhaustive search. Compared to the conventional static scheme where all BSs are always turned on with their maximum transmit powers, DCR can significantly reduce energy consumption, e.g., more than 30% and 50% savings in uniform and non-uniform traffic distribution, respectively.

• The Bulletin of The Korean Astronomical Society
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• v.36 no.1
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• pp.82.1-82.1
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• 2011

We present a new code for solving non-LTE radiative transfer problems in a general grid (RIG). RIG develops from RATRAN code (Hogerheijde & van der Tak 2000) using the Accelerated Monte-Carlo method, and it can cope with line overlap effect among multiple molecular and atomic species. In this algorithm we make grids in arbitrary coordinates adequate to the problem, but, on the other hand, photons propagate in the Cartesian coordinates. For spherical, cylindrical and other well defined coordinate, the problem of tracing photon's path reduces to solving simple quadratic equations. For example, the outflow in the star formation have high dynamic range in scales from a few AU to ~ 0.1 pc and have also cylindrical symmetry. So, we have used (r, ${\alpha}$) coordinate system, where r is the distance from the origin and ${\alpha}$ is z/ R2 in the cylindrical coordinate of (R,z). The (r, ${\alpha}$) coordinate realizes the density - power function of r - and temperature distributions of the problems with smaller numbers of grid than the cylindrical coordinate does, and the former consumes less time to solve the problems than the latter.