• 전기학회논문지P
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• 제67권3호
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• pp.149-154
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• 2018

We consider the system is subject to the linearly polarized oscillatory external field. We study the optical quantum transition Line shapes(QTLS) which show the absorption power and the quantum transition line widths(QTLW) of electron-piezoelectric phonon interacting system. We analyze the magnetic field dependence of the QTLS and the QTLW in various cases. In order to analysis the quantum transition, we compare the magnetic field dependence of the QTLW and the QTLS of two transition process, the intra-Landau level transition process and the inter-Landau level transition process.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2014년도 추계학술대회 논문집
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• pp.927-929
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• 2014

MRE(Magneto-rheological Elastomer) is a material which shows reversible and various modulus in magnetic field. Comparing to conventional rubber vibration isolator, MREs are able to absorb broader frequency range of vibration. These characteristic phenomena result from the orientation of magnetic particle (i.e., chain-like formation). Magnetic reactive powder(MRP), having rapid magnetic reaction, was selected as a magnetic particle to give magnetic field reactive modulus. The mechanical properties of manufactured MREs were measured with the application of magnetic field. The analysis of MR effect was carried out by FFT analyzer with various induced current. As induced magnetic field intensity increased and coated with MRP, increment of MR effect was observed.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제51권2호
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• pp.80-84
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• 2002

This paper presents some of the results of current research on 400kN Suspension Insulator Design. In this paper, authors carried out 2-dimensional field calculation in order to analyse dielectric characteristics of the insulator unit and 3-dimensional field calculation in order to analyse dielectric characteristics of the insulator strings. And the results of puncture tests of insulators were compared with the required field intensity of the insulator As results, it was found that electric field on the insulator unit is severest between two triple junctions, dielectric characteristics of insulator strings are much influenced by the surrounding configuration and the manufactured insulators have good results of puncture tests.

• 정보관리학회지
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• 제32권3호
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• pp.69-97
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• 2015

본 연구는 문헌정보학 측면에서 국외 독서 및 독서교육 연구의 동향을 분석하고 향후의 연구과제를 제시하였다. 이를 위해 첫째, 문헌정보학 분야 국외 데이터베이스(LISTA)의 통제 키워드와 DDC 23판을 검토하여 독서 및 독서교육 관련 주요 연구 영역을 설정하였다. 둘째, 문헌정보학 분야 국외 데이터베이스(LISTA)에서 검색한 지난 100년(1914년~2014년) 동안의 독서 및 독서교육 관련 학술논문(2,115편)을 대상으로 지적구조 분석을 적용하여 연구동향을 분석하였다. 셋째, 이러한 연구동향 분석의 결과에 기초하여 독서 및 독서교육 분야의 향후 연구과제를 제시하였다.

• International Journal of Aeronautical and Space Sciences
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• 제11권4호
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• pp.319-325
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• 2010

For decades, researchers have rigorously studied the characteristics of flow traveling around blunt objects in order to gain greater understanding of the flow around aircraft, vehicles or vessels. Many different types of flow exist, such as boundary layer flow, flow separation, laminar and turbulent flow, vortex and vortex shedding; such types are especially observed around circular cylinders. Vortex shedding around a circular cylinder exhibits a two-dimensional flow structure possessing a Reynolds number within the range of 47 and 180. As the Reynolds number increases, the Karman vortex changes into a three-dimensional flow structure. In this paper, a numerical analysis was performed examining the flow and aero-acoustic field characteristics around a circular cylinder using an optimized high-order compact scheme, which is a high order scheme. The analysis was conducted with a Reynolds number ranging between 300 and 1,000, which belongs to B-mode flow around a circular cylinder. For a B-mode Reynolds number, a proper spanwise length is analyzed in order to obtain the characteristics of three-dimensional flow. The numerical results of the Strouhal number as well as the lift and drag coefficients according to Reynolds numbers are coincident with the other experimental results. Basic research has been conducted studying the effects an unstable three-dimensional wake flow on an aero-acoustic field.

• Journal of the Korean Data and Information Science Society
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• 제20권4호
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• pp.661-672
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• 2009

65세 이상 노인 30명을 대상으로 매트 운동과 필드 운동을 6주간 실시한 후 운동전, 3주 후, 그리고 6주 후에 균형과 보행에 미치는 영향에 대해 알아보기 위해 실시하였다. 측정은 외다리 기립 검사, 버그 균형 검사, 그리고 3차원 동작분석기를 이용하여 보행 분석을 실시하였다. 반복측정자료 분산분석 결과, 시간과 그룹 간 상호작용 효과는 활보길이에서 유의한 차이가 있었고, 외다리 기립, 버그 균형, 분속수, 속도는 유의한 차이가 없었다. 중재기간 별 효과크기를 검정해 본 결과 중재 전과 중재 6주 후, 중재 3주 후와 중재 6주 후에서 유의한 차이가 있었다.

• 한국방사선학회논문지
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• 제17권2호
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• pp.267-275
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• 2023

전 세계적으로 방사선종사자들의 피폭 기록은 관심의 대상이며 피폭이 일어나는 분야에 대한 분석이 수행되고 있다. 한국에서는 유관부처에 따라 보건복지부, 농림축산식품부, 원자력안전위원회에서 종사자들의 피폭을 11개 업종으로 나누어 기록을 수집 분석하고 있다. 그러나 이러한 분류 체계는 유엔방사선영향과학위원회를 비롯한 주요 국가들의 분류 체계와는 정합성이 부족하다. 국내의 종사자 피폭 분류 체계는 명확한 분류 기준이 없고 업종 특성 등을 반영해주지 못하고 있다. 유엔방사선영향과학위원회의 분류 체계를 바탕으로 국내의 분류 체계를 핵주기 분야, 의료분야, 산업분야, 그 외 분야(교육/연구, 군사/공공)의 5개 대분류 체계와 그에 따른 세 분류 및 직군 분류를 본 연구를 통해 제안하였다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 춘계학술대회 논문집
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• pp.384-389
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• 2011

The electric railway cars are operated by high voltage supply through the catenary wire. Also, numerous electric equipments operated by electric signal are distributed in the electric railway cars. Such electric equipments are exposed to EMI/EMC problems, and there is the possibility that the magnetic field due to the catenary wire current takes effect on the electromagnetic field in the electric railway cars which move under the catenary wire. There is the possibility that the electromagnetic interference generates in view of the operation of many electric equipments in the electric railway cars. There is the possibility that the communication device faults generate, and that the hazards on the human beings generate. In this paper, we predict the magnetic field around the catenary wire, and obtain the exact magnetic field distribution by comparing the analytic results and the numerical results. Finally, we confirmed the possibility of the passive loop mitigation by comparing the analytic results and the numerical results through the passive loop mitigation technique.

• 한국정밀공학회지
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• 제18권10호
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• pp.84-92
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• 2001

Commercial eddy current dynamometers control the torque of rotating body, power supply machine, with the field coil current being operated as a braking force. In this paper, we studied the relation between field coil current and torque load of eddy current dynamometer. By the torque measuring analysis of eddy current dynamometer it is linear relation between the brake force measured from a torque meter which is installed at the case of dynamometer and the multiplied shaft rpm by the squares of field coil current (N$\times$I$^2$). To prove the relation, it was experimented and showed that the torque operated by the rotating body can be measured with the shaft rpm and the field coil current of the eddy current dynamometer. This result shows a possibility that eddy current dynamometer can measure the torque of rotating body without a torque measuring device. such as load cell.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2014년도 추계학술대회 논문집
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• pp.288-291
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• 2014

MRE(Magneto-rheological Elastomer) is a material which shows reversible and various modulus in magnetic field. Comparing to conventional rubber vibration isolator, MREs are able to absorb broader frequency range of vibration. These characteristic phenomena result from the orientation of magnetic particle (i.e., chain-like formation) in rubber matrix. In this study, Silicon was used as a matrix in order to manufacture MREs. Magnetic reactive powder(MRP), having rapid magnetic reaction, was selected as a magnetic particle to give magnetic field reactive modulus. The mechanical properties of manufactured MREs were measured with the application of magnetic field. The analysis of MR effect was carried out by FFT analyzer with various induced magnetic field. As the addition of CIP and induced magnetic field intensity increased, increment of MR effect was observed.