• Tribology and Lubricants
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• 제27권3호
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• pp.156-161
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• 2011

The rectangular waveguide technique can be used to measure the complex permittivity of dielectric material of various thickness and cross section. This paper presents the analysis system of engine oil permittivity at which deterioration of engine oil is measured at the X-band(8-12.5 GHz). The middle of the rectangular waveguide has engine oil case and is connected with VNA(Vector Network Analyzer) for the measurement of the transmission$(S_{21})$ and reflection$(S_11)$ and then the permittivity is extracted. The deterioration of engine oil is proved by the comparison with both the extracted data and reference data. As the additional research, This paper suggest that an accurate permittivity is considered by not only the wave guide length but the air gap between oil case and the waveguide.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 1996년도 춘계학술발표회논문집(2)
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• pp.467-472
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• 1996

This study discusses special aspects of severe accident related recriticality modeling and analysis in the Advanced Neutron Source (ANS) reactor.$^{1, 2)}$ The analytical comparison of three elements core to former two elements case is conducted including evaluation of suitable nuclear cross-section sets to account for the effects of system configulation, fuel and moderator mixture temperature, material dispersion and the other thermal-hydraulics. Three elements core ANS reactor is the alternative core design which was proposed as a modified core design, with three fuel elements instead of two, that would allow operation with only 50% enriched uranium (former uranium fuel is the baseline design value of 93%) A comprehensive test matrix of calculations to evaluate the threat of a criticality event in the ANS is described. Strong dependencies still on geometry, material constituents, and thermal-hydraulic conditions are verified. Therefore, the concepts of mitigative design features are qualified.d.

• International Journal of Ocean System Engineering
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• 제2권3호
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• pp.195-199
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• 2012

This paper reports a new analytical method to calculate the planar displacement of structures. The cross-sections were assumed to remain in plane and the deflection curve was evaluated using the curvature values geometrically, despite being solved with differential equations. The deflection curve was parameterized with the arc-length of the curvature values, and was taken as an assembly of chains of circular arcs. Fast and accurate solutions of complex deflections can be obtained easily. This paper includes a comparison of the nonlinear displacements of an elastic tapered cantilever beam with a uniform moment distribution among the proposed analytical method, numerical method of the theory and large deflection FEM solutions.

• 한국생활과학회지
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• 제13권5호
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• pp.765-776
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• 2004

The objectives of this study are to compare the levels of materialism with hedonic-utilitarian shopping values among 645 college students in Ulsan and Seoul, Korea; Columbus, Ohio, USA; and Nagasaki, Japan, and to analyze the impact of materialism on hedonic-utilitarian shopping values. As for the levels of hedonic shopping values, the students in Japan and Ulsan had the highest of all, whereas for the levels of utilitarian shopping values, those in Ulsan had the highest. For the levels of materialism, the students in Ulsan had the highest of all and those in Seoul had the lowest. And three scales in the materialism had a different influence on hedonic-utilitarian shopping values.

• 복합신소재구조학회 논문집
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• 제6권3호
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• pp.20-25
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• 2015

This paper introduces a digital image processing(DIP) method as a method for measuring the displacement of pylon. The comparison of DIP results and ANSYS analysis results verified the validity of the image processing technique. Normalized cross-correlation(NCC) coefficient was used and experiments were performed three times. It shows that the displacement difference was 22% and 5% compared to ANSYS results. Therefore, the image processing method is expected to be able to measure the displacement of pylon sufficiently.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2009년도 제40회 하계학술대회
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• pp.1175_1176
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• 2009

In comparison with different mass transportation systems, the streetcar is lower, both in speed and transportation capacity. However, it has the advantage of reducing the cost of construction, because it makes infrastructure simple, by using the road. It is proper in the city, where the population is few, to raise the efficiency of traffic. The convenience is high to passengers. On time accuracy and the commercial speed is influenced by operating condition. Generally that is organized into 21m degree in 6 quantity. All passengers in a streetcar are about 180 people. The maximum speed is 40~60km/h. When road traffic is considered, the speed can be reduced to 15km/h. To enhance the speed, the construction of a priority signaling system is necessary which is integrated with the road traffic operation information system. In order to develop a better Traffic Control System which is connected to a Traffic Control Center, a Priority Signaling System which incorporates Intersection Control Technics must be included.

• 대한기계학회논문집A
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• 제20권7호
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• pp.2223-2233
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• 1996

The analytical solutions for the free vibration of cross-ply laminated composite cyllindrical shell with axial stiffeners(stringers) are presented usint the energy method. The stiffeners are taken to be smeared over the surface of shell with the smeared stffener theory. The effect of the parameters such as the stacking sequences, the shell thichness, the shell radius-to stringer depth ratio, the stringer depth-to width ratio, the shell length-to radius ratio are studied. By comparison with the previously published experimental results and the analytical results for the stiffened isotropic cylindrical shell and the unstiffened orthotropic composite laminated cylindrical shell, it is shown that natural frequencies can be determined with adequate accuracy.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회A
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• pp.968-973
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• 2007

This paper presents an electromagnetic design for the magneto-rheological fluid valve. The MR valve can control high-level fluid power without moving parts, due to the apparent viscosity controllability of the MR fluid in magnetic fields. In order to improve the static characteristic of the MR valve, the length of the flux path is decreased by removing the unnecessary bulk of the yoke. Then, in order to improve the dynamic and hysteretic characteristics, the magnetic reluctance of the ferromagnetic material is increased by minimizing the cross sectional area through which the flux passes. Two MR valves, one is a conventional type valve and the other is the proposed one, were fabricated and performance evaluation is experimentally achieved through the comparison study using by-pass damper system.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회A
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• pp.204-209
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• 2007

This study was carried out to analyze the effect of wind load on the structural stability of a container crane according to the increase of the lifting capacity using wind tunnel test and provided a container crane designer with data which can be used in a wind resistance design of a container crane assuming that a wind load at 75m/s wind velocity is applied on a container crane. Data acquisition conditions for this experiment were established in accordance with the similarity. The scale of a container crane dimension, wind velocity and time were chosen as 1/200, 1/13.3 and 1/15. And this experiment was implemented in an Eiffel type atmospheric boundary-layer wind tunnel with $11.52m^{2}$ cross-section area. Each directional drag and overturning moment coefficients were investigated.

• 한국해안해양공학회지
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• 제5권4호
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• pp.369-383
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• 1993

잉여응력의 수정된 형태가 현 모델에서 제시되며 자유수면 이류항의 존재가 파랑에너지식과의 비교를 통해서 입증되었다. 수식모델은 편평한 해빈경사에서의 3차원적인 흐름의 순환패턴을 산출하며 그 결과는 실험치와 비교하여 좋은 일치를 보였다. 마지막으로 수심적분된 특성과 그 수직분포를 연계하여 전 연안역에 적용가능한 준3차원적 모델이 개발되었다.