• The Bulletin of The Korean Astronomical Society
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• v.39 no.1
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• pp.62.1-62.1
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• 2014

We present preliminary results on the chemical differentiation of two dense gas tracers CS and $N_2H^+$ in five 'evolved' starless cores, L1544, L1552, L1689B, L694-2 and L1197, using our mapping observations in $C^{34}S$(J=2-1) and $N_2H^+$(J=1-0) with Nobeyama 45-m telescope. We compared the intensity maps of two molecular lines with 850 ${\mu}m$ continuum data which precisely trace the density distribution of the dense cores, finding that all of our targets show the central depletion holes in CS distribution, but the similar distribution in $N_2H^+$ to the one in dust continuum. Our data confirm the claim that CS molecule generally deplete out in the central region in starless cores, while $N_2H^+$ keep abundant as they get evolved. The detailed quantitative analysis on CS depletion in the dense cores, for example, the size of CS depletion area and radial (or gas density) dependence of CS depletion, is underway and will be presented in the meeting.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.10a
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• pp.162-165
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• 2005

The objective of this research work is to investigate into the three-dimensional temperature distribution using quasi steady-state heat transfer analysis fur the case of the laser cutting of CSP 1N sheet using high power CW Nd:YAG laser. The laser heat source is assumed as a volumetric heat source with a gaussian heat distribution in a plane. Through the comparison of the results of analyses with those of the experiments, the optimal finite element model is obtained. Finally, characteristics of the three-dimensional heat transfer and temperature distribution have been estimated by the optimal finite element model.

• Journal of Ecology and Environment
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• v.37 no.4
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• pp.217-223
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• 2014

We conducted a distributional survey of Pectinatella magnifica, an invasive species, in the Geum River and the Nakdong River from July 12 to July 25, 2014. The spacing between the study sites was 10 km along the main channels for the Geum River (n = 12, 120 km) and the Nakdong River (n = 38, 380 km) from the estuarine barrage to upper part of main channel. Pectinatella magnifica was detected along the riparian zone (within 100 m) at each of the study sites. Presence rate of P. magnifica in Geum River and Nakdong River was 25% and 32.6%, respectively. The colony number of P. magnifica at Geum River ($9.5{\pm}3.1colony/m$, n = 3) was over 94 fold higher than that in the Nakdong River ($0.1{\pm}0.1colony/m$, n = 16). The Total length distribution of P. magnifica had a truncated bell shape at each rivers (mean length: $14.0{\pm}1.2cm$ for Geum River (n = 32), and $16.8{\pm}1.4cm$ for Nakdong River (n = 52)). These findings could provide basic information regarding the distribution pattern of P. magnifica in a new invasion area.

• Journal of Soil and Groundwater Environment
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• v.20 no.7
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• pp.23-33
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• 2015

This study was conducted to provide the preliminary data on preparation for policy decisions regarding the groundwater supply scheme for N. Korea vulnerable to drought. Agricultural activities oriented to upland field due to the mountainous terrain more than 79% as well as the diversity of rainfall distribution over the country make more vulnerable to structural problems in the drought in N. Korea. Therefore, in anticipation of the expansion of exchange policies in agricultural sector, the available amount of groundwater needed for sustainable water resources supply was estimated for each administrative district after analyzing alluvium and hydrogeology distribution in N. Korea. Overall, the available amount of groundwater was estimated to 22.3 billion m³ (0.18 million m³/km²). The available amount of groundwater per unit area in Ryanggangdo and Gaesungsi was appeared very high in each of 0.56 and 0.39 million m³/km², respectively, and it would be interpreted that two districts have relatively wide area of volcanic rocks and alluvium with highly permeable characteristics, respectively. Finally, to maximize the utilization of this study result, the available amount of groundwater distribution map was developed on the basis of the 1 × 1 km grid network over the entire N. Korea.

• PNF and Movement
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• v.16 no.3
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• pp.345-353
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• 2018

Purpose: The purpose of the present study was to compare the effects of proprioceptive neuromuscular facilitation (PNF) and static stretching on weight distribution and flexibility for trunk flexion. Method: Sixty participants who had no musculoskeletal disorders were recruited from a local university within six months of this study. The participants were randomly assigned to a PNF stretching group (N=30) and a static stretching group (N=32). For the pre-and post-measurement design, the left-right weight distribution, anterior-posterior weight distribution, and finger-to-floor distance (FFD) were measured before and after the stretching interventions. Result: The FFD results were significantly improved after the interventions, regardless of the group differentiation (p<0.05). The PNF stretching intervention significantly increased the differences between anterior and posterior weight distribution compared to the static stretching group (p<0.05). Conclusions: Both the PNF and static stretching interventions could improve flexibility for trunk flexion mobility. Although the PNF intervention improved the weight distribution in the anterior-posterior direction, further research is required to investigate the various PNF interventions on left-and-right and anterior-posterior weight distribution.

• Journal of Astronomy and Space Sciences
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• v.26 no.1
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• pp.9-24
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• 2009

We compare the relation among the annual distribution of sunspots: coronal mass ejections (CMEs) and geomagnetic storms and North-South asymmetry during solar cycle 23. For this purpose, we calculate correlation coefficients between (i) annual distribution and N-S asymmetry of CMEs - sunspots (ii) distribution of CMEs - occurrence number of geomagnetic storms (iii) distribution of sunspots - occurrence number of geomagnetic storms. We find that (i) the annual distribution of total CMEs has good correlation with distribution of annual average of sunspots but poor correlation with N-S asymmetry of sunspots, N-S asymmetry of CMEs has good correlation with N-S asymmetry of sunspots: (ii) total and N-S asymmetry of CMEs have poor correlation with occurrence number of geomagnetic storms, it's, however, well correlated with the classified groups of CMEs (Ap, Dst and an indices vs. fast CMEs($\upsilon$ > $1000kms^{-1}$), Dst index vs. Halo CMEs), and (iii) sunspot numbers and area are correlated with occurrence number of geomagnetic storms. We conclude that annual distribution of CMEs and sunspots have well correlated with geomagnetic storms, N-S asymmetry of CMEs and sunspots have poor correlated with the geomagnetic storms.

• Journal of Environmental Health Sciences
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• v.47 no.4
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• pp.303-309
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• 2021

Background: Humidifier disinfectant is a biocidal product used in the water tanks of humidifiers to prevent the growth of microorganisms. Although there are a huge number of cases of reported humidifier disinfectant-related health effects across the entire Korean population, their numbers are distributed differently depending on the region. Objectives: This study aimed to investigate the regional distribution of enrollment cases who reported humidifier disinfectant-related health effects. Methods: This study used data on 6,240 subjects who experienced humidifier disinfectant-related health effects and who enrolled their cases which is conducted by the Korea Ministry of Environment. We examined the regional distribution of the enrolled cases based on sixteen administrative divisions and assessed the: 1) crude number; 2) proportional rate; and 3) age-standardized proportional rate of enrollment by region. Results: When we examined the crude number of enrollments by region, the highest number were in Gyeonggi-do Province (n=1,896), followed in order by Seoul (n=1,405), Incheon (n=436) Busan, Daegu, Gyeongsangnam-do Province, Daejeon, Chungcheongnam-do Province, Gyeongsangbuk-do Province, Jeollabuk-do Province, Gwangju, Chungcheongbuk-do Province, Gangwon-do Province, Jeollanam-do Province, Ulsan, and Jeju-do. When we examined proportional rate of the regional enrollment (cases per 100,000 population), Daejeon (n=16.2) was the region with the highest rate, followed in order by Gyeonggi-do Province (n=16.1), Incheon-do Province (n=15.9), Seoul, Daegu, Gwangju, Jeollabuk-do Province, Chungcheongnam-do Province, Busan, Chungcheongbuk-do Province, Gangwon-do Province, Gyeongsanbuk-do Province, Gyeongsangnam-do Province, Ulsan, Jeju-do, and Jeollanam-do Province, which is inconsistent with the order in terms of crude numbers. However, when we examined the age-standardized proportional rate of regional enrollment (cases per 100,000 population), their ranked distribution is consistent with the crude rate. Conclusions: This study observed that the regional distribution of the enrolled cases who reported humidifier disinfectant-related health effects is inconsistent with the regional distribution of the proportional rate of enrollment cases, which may be caused in part by the volume of the inherent population of each region.

• Journal of the Korean Statistical Society
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• v.17 no.1
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• pp.46-55
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• 1988

Two-piece double exponential distribution (TPDE) with one piece $(X \leq 0)$ having the scale parameter $\theta_1$ while the other piece (X>0) having $\theta_2$ is considered here. Distribution of the sum of n-independent variables from such a distribution is obtained. Special cases of this distribution are also treated. Next, distribution of the ratio of two independent (TPDE) variables is derived. As an extension, distribution of $x_1/x_2x_3$ is expressed terms of hypergeometric functions. A small table gives the power of the test regarding double exponential against (TPDE).

• Journal of applied mathematics & informatics
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• v.25 no.1_2
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• pp.541-550
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• 2007

This paper presents characterizations of the power distribution with the parameter $\beta=1$ by the independence of the lower record values. We prove $X\;{\in}\;POW({\alpha},\;1)$ for ${\alpha}\;>\;0$, if and only if $\frac{X_{L(n)}}{X_{L(m)}}$ and $X_{L(m)}$ for $1\;{\leq}\;m\;<\;n$ are independent. And we prove that $X\;{\in}\;POW({\alpha},\;1)$ for ${\alpha}\;>\;0$, if and only if $\frac{X_{L(m)}-X_{L(m+1)}}{X_{L(m)}}$ and $X_{L(m)$ for $m\;{\geq}\;1$ are independent or $\frac{X_{L(m)}-X_{L(m+1)}}{X_{L(m+1)}}$ and $X_{L(m)}$ for $m\;{\geq}\;1$ are independent.

• Proceedings of the KIEE Conference
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• 2006.10b
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• pp.159-162
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• 2006

In this paper energy distribution function in $SiH_4$ has been analysed over the E/N range 0.5${\sim}$300Td and Pressure value 0.5, 1.0, 2.5 Torr by a two-term approximation Boltzmann equation method and by a Monte Carlo simulation. The motion has been calculated to give swarm parameters for the electron drift velocity, diffusion coefficient, electron ionization, mean energy and the electron energy distribution function. The electron energy distribution function has been analysed in $SiH_4$ at E/N=30, 50Td for a case of the equilibrium region in the mean electron energy and respective set of electron collision cross sections. The results show that the deduced electron drift velocities, the electron ionization or attachment coefficients, longitudinal and transverse diffusion coefficients and mean energy agree reasonably well with theoretical for a rang of E/N values.