• International Journal of Contents
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• v.3 no.1
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• pp.1-8
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• 2007

The distributions of the minimum correlated F-variable arises in many applied statistical problems including simultaneous analysis of variance (SANOVA), equality of variance, selection and ranking populations, and reliability analysis. In this paper, negative binomial sampling technique is employed to derive the distributions of the minimum of chi-square variables and hence the distributions of the minimum correlated F-variables. The work presented in this paper is divided in two parts. The first part is devoted to develop some combinatorial identities arised from the negative binomial sampling. These identities are constructed and justified to serve important purpose, when we deal with these distributions or their characteristics. Other important results including cumulants and moments of these distributions are also given in somewhat simple forms. Second, the distributions of minimum, chisquare variable and hence the distribution of the minimum correlated F-variables are then derived within the negative binomial sampling framework. Although, multinomial theory applied to order statistics and standard transformation techniques can be used to derive these distributions, the negative binomial sampling approach provides more information regarding the nature of the relationship between the sampling vehicle and the probability distributions of these functions of chi-square variables. We also provide an algorithm to compute the percentage points of the distributions. The computation methods we adopted are exact and no interpolations are involved.

• Journal of the Korean Society of Safety
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• v.22 no.2 s.80
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• pp.41-46
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• 2007

This paper considers the electrical shock risk of the human body due to underwater leakage current in such places of public baths. Many submerged electric facilities in a public bath may create a severe electric shock hazard for the human body, since wet body in an accidentally energized bathtub can result in low electrical resistance through the human body for leakage or fault currents. Therefore a major consideration, in the context of electrical safety underwater, is the shock risk to the bather as a result of electric current flowing through the water in bathtub. To assess the electric shock risk and to analyze the potential distribution in a bathtub, 2 different situation cases are set up, then experimental and simulation methods are adopted. The validity of 2 cases of simulation and experiment data in a bathtub for electric distribution underwater are compared and analyzed. Also electric shock risk assessment underwater in a real public bathtub by simulation program package, Flux 3D, was conducted herein, and the results are presented and discussed.

• Journal of the Korean Society of Safety
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• v.33 no.3
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• pp.21-26
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• 2018

Approximately 20% of the total fire is electrical fire, and electrical energy is a potential source of heat. Large-scale fault currents that occur during a line ground fault flow into electric utility poles, electric power equipment, or electric appliances of the customer, and cause simultaneous electrical fire. In this paper, we investigated the possibility of fire through the change of fault current flowing in faulty and sound feeder in case of 1 line ground fault in 22.9 kV distribution line. We propose a fire investigation analysis method for simultaneous multiple electrical fire such as evidence analysis method, and fault current occurrence confirmation method in case of fire accident by analyzing the fault current occurring in the ground fault in the distribution line using EMTP, electric power system analysis program.

• Journal of the Korean Wood Science and Technology
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• v.44 no.2
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• pp.231-240
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• 2016

The change in chemical compositions of leachate and medium density fiberboard (MDF) from a laboratory-scale simulated landfill which constructed in a plastic container containing alternating layers of soil and MDF was investigated to evaluate decomposing of MDF in soil. Four treatments were conducted: 1) MDF in soil, 2) MDF only, 3) cured UF resin in soil, and 4) soil only. Molecular weight (MW) distribution of compounds in leachate from soil only treatment did not change over time. In UF resin in soil treatment, the MW distribution shifted to a lower MW distribution over time, while the peak shifted to the left indicated changing to higher MW distribution in leachate from treatment 1 and 2 contained MDF. Higher percent nitrogen in leachate was observed in MDF containing treatments due to the UF resin in the MDF. The percent carbon slightly increased in MDF only while that greatly decreased in MDF in soil treatment maybe due to bacterial activity. The percent of extractable materials from the MDF decreased greatly on day 35 compare to day 0, and subsequently did not change much on day 77. In contrast, percent holocellulose and lignin did not change much over time. No structural change of the wood fiber in MDF occurs during the study. Water-soluble materials from MDF in soil contributed the change in chemical composition of leachate.

• The Journal of Korean Academy of Prosthodontics
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• v.30 no.2
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• pp.203-224
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• 1992

The purpose of this study was to evaluate the stress distribution developed in supporting structures by distal extension removable partial denture with 4-types of direct retainer. The direct retainers examined were Akers clasp, RPI clasp, RPA clasp and RPL clasp in bilateral & unilateral free end case. 3-dimensional photoelastic stress analysis was used to record the isochromatic fringe patterns and to calculate the compressive stress at measuring points. The results were as follows. 1. In bilateral free end case, RPI clasp exhibited the similar stress distribution on distal and mesial alveolar crest but Akers clasp exhibited higher stress concentration on distal alveolar crest than mesial alveolar crest. 2. In bilateral free end case, RPA clasp and RPL clasp exhibited the similar stress distribution on distal and mesial alveolar crest and RPL clasp exhibited higher stress concentration on buccal alveolar crest than lingual alveolar crest. 3. Akers clasp produced high stress concentration on residual alveolar ridge distally, but RPI clasp, RPA clasp and RPL clasp produced even stress distribution on residual alveolar ridge. 4. Removable partial denture in unilateral free end case exerted higher stress on abutment tooth root apex than bilateral distal extension removable partial denture.

• Food Science and Biotechnology
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• v.15 no.2
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• pp.232-237
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• 2006

Bacillus cereus group comprising B. cereus, B. thuringiensis, and B. mycoides was differentiated by polymerase chain reaction (PCR) and colony morphology. Prevalence of B. cereus group in rice and distribution of enterotoxin genes were determined as possible food poisoning agents. PCR using primers targeted for gyrB and cry genes could distinguish B. thuringiensis from B. cereus, and B. mycoides was differentiated by rhizoid morphological characteristics on nutrient agar. Among 136 rice and their processed products, prevalence of B. cereus group was 40%. B. cereus group consisted of 54 B. cereus, 11 B. thuringiensis, and 1 B. mycoides. Major isolates were B. cereus, with B. thuringiensis detected up to 10% among edible rice tested. Five enterotoxin genes, hbl, nhe, bceT, entFM, and cytK, were broadly distributed among B. cereus group, especially in B. cereus and B. thuringiensis. Prevalence of B. cereus group in rice and enterotoxin distribution suggest B. thuringiensis and B. cereus are toxigenic strain that should be controlled in rice and its products.

• The Journal of Internal Korean Medicine
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• v.21 no.1
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• pp.135-145
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• 2000

Objective : This study has been made to analysis of clinical type of vertigo prodromic Cerebral Vascular Disease in stroke patients who admitted to sangji oriental hospital department of circulatoty internal medicine in the period from July. 1999 to October 1999. Methods : A Questionaire was done after explanationin details to patients and agreement of patients. The inquire was done as follows. Sex and age, risk factor of stroke, type of stroke, existence of vertigo last three years before stroke attack, the beginning age of vertigo and period of prevalence, frequency, continuance time of vertigo, predilection season and time, factor of causing vertigo, accompanying symptoms of vertigo, severity of vertigo. Result and Conclusion : The existence of Rotation sense(Rotation group and non-Rotation group) and the type of Stroke is no difference significantly but the Rotation vertigo group and non-Rotation vertigo group is difference significantly in distribution. The sixties in age of vertigo attack, previous vertigo before 3 year Stroke attack, irregular in predilection season of vertigo, have a high frequency significantly in distribution and previous period of vertigo has no significantly difference in distribution. One or two per a month in frequency of vertigo, below 5 minute in continuance time of vertigo, irregular in predilection time of vertigo, stand up and sit down in causing vertigo position have a high frequency significantly in distribution.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2004.08a
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• pp.297-306
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• 2004

This study investigated Austenite Grain Size (AGS) distribution in Low-Speed Round-Oval Rolling. Rolling experiments were done along with the AGS numerical modeling to characterize the final AGS distribution and its kinetics behavior. For bar rolling experiment, we utilized the pilot rolling mill, operating at 34 fixed rpm, at POSCO Technical Research Laboratories. To investigate the microstructural observation, the rigid-viscoplastic finite element analysis was combined with Hodgson's AGS evolution model. To consider the transient thermal history in the integrative AGS modeling, additivity rule was introduced. The integrated analysis revealed that static or meta-dynamic recrystallization is responsible for the AGS difference in the inner or outer region of rolled bar. Comparative study showed that the current AGS modeling approach can be used to model the overall AGS distribution in bar rolling processes. For more accurate AGS prediction, the AGS modeling method should be verified under the various rolling conditions such as different rolling speeds and different deformations.

• The Bulletin of The Korean Astronomical Society
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• v.43 no.1
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• pp.60.2-60.2
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• 2018

We present the near infrared JHK photometric properties and the spatial distribution of red supergiants(RSGs) of NGC 3623, NGC 3627 and NGC 3628 in the Leo Triplet system using the data obtained with 3.8m UKIRT(United Kingdom Infra-Red Telescope) at Hawaii. We checked interaction between the three galaxies by making a spatial density map of RSGs. From (J-K,K)0 Color-Magnitude Diagram which include resolved stars in three galaxy and control field with PARSEC isochrone, we figured out the RSG candidates of the Leo triplet are at 0.9<(J-K)0<1.2, mK<17.5 and separated them from background and foreground sources. Using gaussian kernel density estimation, we drew spatial density map of RSGs in the Leo triplet with an assumption that all RSGs are an identical population. The density map shows extended features of NGC 3628 to NGC 3627 along the declination direction. The asymmetries between NGC 3627 and NGC 3628 might be evidence for that the distribution of actual star components(RSGs) follows the neutral hydrogen distribution and also for interaction between two galaxies. And the extended features along the right ascension direction might be a supporting evidence for the existence of a TDG(Tidal Dwarf Galaxy). In case of NGC 3623, we could not see any sign of interaction in density map.

• Journal of Environmental Science International
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• v.20 no.3
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• pp.385-394
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• 2011

Organotin compounds (OTs), namely butyltins compounds (BTs) and phenyltin compounds (PhTs), were measured in surface and core sediments collected in Jeju harbor. The horizontal and vertical distribution was examined and the relationship between the concentration of OTs and organic matter content and particle size distribution was also studied. BTs were detected in significant concentrations in sediments inside Jeju harbor. PhTs were detected in very low concentrations, compared to BTs. The main species in BTs and PhTs were dibutyltin (DBT) and monobutyltin (MBT), monophenyltin (MPhT), respectively. In the relationships between the concentrations of total BTs and organic carbon content, the significant correlations ($r^2$=0.4898 in surface sediments, $r^2$=0.53 in one core sediments) and no correlation in another core sediments obtained, which is estimated that the distribution of BTs in sediments were affected by several factors, such as their physicochemical properties including organic carbon content, and a tide, etc. In the relationships between the concentrations of total BTs and particle size (mud, sand, and gravel) in sediments, the concentrations of total BTs were higher in the sediments with higher mud content, indicating that higher BTs were distributed with increasing sediments of fine granules.