• Journal of Korean Biological Nursing Science
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• v.10 no.2
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• pp.147-153
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• 2008

Purpose: Methicillin Resistant Staphylococcus aureus (MRSA) has become a major clinical problem and one of the major nosocomial pathogen worldwide. The aim of the study was to investigate the epidemiological characteristics of genotypes of MRSA isolated in the A-hospital ICU. Methods: In the period between December 2007 and May 2008, MRSA was isolated from ICU patients and its surrounding environment. Polymerase Chain Reaction (PCR) was conducted for the detection of MRSA gene. The incidence of MRSA in the clinical isolates of Staphylococcus aureus was examined by using a multiplex PCR. The spa gene of Staphylococcus aureus encodes protein A and is used for typing of MRSA. We used sequence typing of the spa gene repeat region to study the epidemiology of MRSA at a hospital. Results: Two different genotypes of MRSA were identified with 90 isolated from the patients and its surrounding environments in the ICU. Conclusion: This study may contribute to the development of effective strategies for preventing nosocomial infections. Genotyping may have more general application for the study of MRSA epidemic outbreak in hospital and community infection.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.1122-1123
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• 2015

본 논문에서는 회전전기자형 고온초전도 발전기의 이중 계자를 제안하고 설계를 하였다. 기존의 동기발전기는 회전자가 계자이지만, 본 논문에서는 전기자를 회전자로 설계하였다. 고정자인 계자는 전기자의 내측과 외측에 위치하게 설계하여 이중계자라고 하였다. 초전도 선재는 제조사에 의해 규격이 정해져있다. 계자에 대전류를 사용하기 위해서는 적층등의 방법들이 있다. 적층하여 구리 권선으로 계자를 권선시 저항과 인덕턴스의 불균등을 제거하기 위하여 구리 권선을 일정한 간격으로 위치를 변환시키는 전위의 방법이 사용된다. 하지만 초전도 선재의 경우는 꺽기, 비틀기등의 방법이 불가능하므로 이 방법을 사용할 수 없다. 그래서 선재를 펀칭하여 선재를 전위시키는 CTCC(Continuously Transposed Coated Conductors) 등의 방법을 사용한다. 본 연구에서는 CTCC 형태의 초전도 권선을 사용하여 기본 모델과 이중계자 권선을 설계하고 특성을 비교하였다. 초전도 선재를 적층하여 사용함으로 계자부의 면적은 증가하지만 인덕턴스, 길이등의 불균등을 제거할 수 있으며 적층 선재수가 증가할수록 계자부 면적은 감소하는 장점이 발생한다.

• Journal of computational fluids engineering
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• v.14 no.3
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• pp.105-114
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• 2009

A numerical study of the flow characteristics inside a U-type circular tube is carried out in this paper. The numerical simulations carried out by using a Navier-Stokes code which is commercially available. Before detailed numerical simulations, validation of present numerical approach is made by comparing numerical solutions with experimental data. Numerical simulations are performed to study the effect of curvature on the flow characteristics inside a U-type tube. Numerical solutions show that a significant effect on the secondary flow structure in the cross section of the tube, especially in the curved section is shown when the curvature ratio, ratio of curvature to tube diameter, is smaller than about 3.5. As the curvature ratio decreases below 3.5, a counter rotating vortex is found below the primary vortex in the cross section of the tube. Another dramatic change of the flow structure is the formation of streamwise separation zone when the curvature ratio is decreased below 1.25.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.18 no.12
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• pp.52-58
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• 2019

This study numerically analyzed the icing process in a U-shaped pipe exposed to the outside by considering the mushy zone of freezing water. Numerical results showed that the flow was pulled outward due to the U-shaped bend in the freezing section exposed to the outside, which resulted in the ice wave formation on the wall of the bended pipe behind. At the same time, the formation of a corrugated ice layer became apparent due to the venturi effect caused by the ice. The factors affecting the freezing were investigated, including the change of the pipe wall temperature, the water inflow velocity, and the pipe bend spacing. It was found that, as a whole, the thickness of the freezing layer increased as the pipe wall temperature decreased. It was also found that the freezing layer became relatively thin when the inflow rate of water was increased, and that the spacing of the pipe bends did not significantly impact the change in the freezing layer.

• Korean Journal of Materials Research
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• v.7 no.9
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• pp.763-771
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• 1997

이규화몰리브덴 고온발열체의 제조공정을 개발하였다. 원료분말은 상용 MoSi$_{2}$분말이었으며 Bentonite, Si$_{3}$N$_{4}$, B, ThO$_{2}$를 각각 가소제와 첨가제로 사용하였다. 이들은 진공압출, 소결, 단자부 기계가공, U자형 성형, 용접 등의 과정을 거쳐 U자형 발열체로 제조되었다. 사용제품의 분석결과 최근 사용온도가 크게 증가된 것으로 알려진 190$0^{\circ}C$용 발열체는 다량(33wt%)의 W이 Mo을 치환하고 있는 것으로 나타났다. 발열체의 전기비저항은 겉보기 밀도가 증가함에 따라 급격하게 감소하는 경향을 보였으며 첨가물들의 영향은 미미하였다. 1400-1$600^{\circ}C$에서 용접한 경우 용접면에서의 전기비저항은 비용접부보다 낮았으며 용접온도가 증사함에 따라 감소하였다. 발열시험결과 제조된 발열체는 표면온도가 1$700^{\circ}C$이하에서는 문제가 없었으며 175$0^{\circ}C$ 이상의 온도에서는 원형의 융기가 표면에 발생하면서 급속하게 파괴되었다. 이 융기는 X-선 회절분석결과 SiO로 밝혀졌으며 따라서 발열체의 파괴는 MoSi$_{2}$/SiO$_{2}$계면에서의 Si(in MoSi$_{2}$) + SiO$_{2}$=2SiO(g)반응에 으해 일어나는 것으로 판단된다.

• Journal of KSNVE
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• v.9 no.5
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• pp.975-983
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• 1999

This paper describes the dynamic characteristics of the joint structures in case of using the simplified beam model in the F. E. analysis. The modeling errors, when replace the shell with the beam, are investigated through F. E. normal modes analysis. Normal mode analysis were performed to obtain the natural frequencies of the L and T shaped joints with various type of channels. The results were analyzed to access the effects of the models on the accuracy of F.E. analysis by identifying the geometric factors which cause the error. The geometric factors considered are joint angle, channel length, thickness and area ratio of the hollow section to the filled one. The joint stiffness evaluation technique is developed in this study using normal modes analysis with Lumped Mass. With this method, the progressively improved results of F. E. analysis are obtained using the simplified beam model. The static and normal modes analysis are performed with the joint stiffness values obtained by the Kazunori Shimonkakis' virtual stiffness method and the proposed method and these simplified modeling errors are compared.

• Proceedings of the Korean Society for Food Science of Animal Resources Conference
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• 2005.10a
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• pp.123-126
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• 2005

본 연구는 고등동물의 불포화지방산 생합성의 핵심 효소로 알려져 있는 Stearoyl-CoA desaturase(SCD) 유전자의 특정한 단일염기다형(single nucleotide polymorphism; SNP)이 한우의 도체 및 육질형질에 미치는 영향을 분석하기 위해 SCD 유전자의 Intron 7번 영역의 특정부위를 포함하는 primer를 제작하고, 염기서열 분석을 통하여 유전자 구조를 해석한 결과 총 211bp 크기를 갖는 염기서열의 122번째에서 아데닌(A)${\leftrightarrow}$구아닌(G) 염기치환으로 발생한 단일염기다형(SNP) 부위를 발견하였다. 이들 단일염기다형 염기서열 부위를 PCR-SSCP(single-strand conformation polymorphism) 기법을 이용하여 분석한 결과 3종류의 SNP 유전자형(A/A, A/G 및 G/G)을 검출하였다. 이 가운데 A/G 유전자형이 한우의 근내지방도와 등지방두께와 고도의 유의적 연관성이 있다는 새로운 사실을 발견하였다. 따라서, 본 연구를 통해 개발된 한우 SCD 유전자의 특정한 단일 염기다형 표지인자는 한우의 연령 및 성별에 관계없이 육질이 우수한 고급육을 생산하는 우량 한우의 조기식별에 매우 유용한 DNA 표지인자로 활용할 수 있을 것으로 기대된다.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.10 no.5
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• pp.757-765
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• 1999

In this paper, L-Type aperture coupled circular polarization patch antenna for mobile communication(IMT-2000, 1.9375 GHz), which is capable of being mounted in mobile unit, was designed and fabricated. This antenna is expanded to the $2\times2$ circular polarization array antenna for satellite mobile communications which are using the L-band frequency. The results are as followings : Returnloss 18.56 dB, beamwidth $60^{\circ}$, gain 7 dBd, axial ratio 0.9 dB in the case of single element and returnloss 28.43 dB, beamwidth $38^{\circ}$, gain 9.8dBd, axial ratio 1.5 dB in the case of $2\times2$ array, respectively.

• Journal of architectural history
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• v.13 no.4 s.40
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• pp.125-138
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• 2004

Open-rectangular plan Hanok is one of the major types that compose the urban tissues of Bukchon, a typical traditional residential area in Seoul. Through the comparison of the cadastral map of 1912 and the aerial photograph of 1962, the paper has given the outline of the and the distribution of Open-rectangular plan Hanok at Bukchon. And the paper defines the characteristics of Open-rectangular plan Hanok at Bukchon as followings. First, Open-rectangular plan Hanok at Bukchon is the mutated type of Open-rectangular plan Hanok in Kyong-gi Province. Second, the composition and characteristics of Bakat-chae and outer-courtyard have been changed through the adaptation itself to the compact lots of urban neighborhood. Third, the composition and characteristics of An-chae has not been changed except the inner corner bay, that gives the lights and view to An-bang through the window. And the comparison and observation of four examples, the paper defines the identities of Open-rectangular plan Hanok at Bukchon. The partial transformation comes from the conflicts and adjustments with the structure of alley and the topographical condition of lots.

• Journal of the Korean Data and Information Science Society
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• v.23 no.3
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• pp.467-474
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• 2012

Human diseases and livestock economic traits are not typically the result of variation of a single genetic locus, but are rather the result of interplay between interactions among multiple genes and a variety of environmental exposures. We have used linear regression model for adjusted environmental effects and multifactor dimensionality reduction (MDR) method to identify gene-gene interaction effect of statistical model in general. Of course, we use 5 SNPs (single uncleotide polymorphism) which were studied recently by Oh et al. (2011). We apply the MDR (multifactor demensionality reduction) method on the identify major interaction effects of single nucleotide polymorphisms responsible for economic traits in a Korean cattle population.