• 한국윤활학회:학술대회논문집
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• 한국윤활학회 1998년도 제27회 춘계학술대회
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• pp.256-262
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• 1998

Many lubricated systems experience boundary, lubrication condition during operation. However, the friction and wear characteristics of boundary lubrication are not clearly understood. In this work the factors which affect the friction and wear between boundary lubricated metallic surfaces are investigated. Experiments were performed on atuminium, copper, and SM45C with bearing ball using a pin-on disk type tester. The experimental conditions were determined by Taguchi experimental method. From the experimental results, the major factors that influence the friction and wear characteristics of boundary lubrication could be identified.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 1998년도 제28회 추계학술대회
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• pp.82-90
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• 1998

Machines that normally operate under fluid film lubricated condition also experience surface damage. This is largely due to the failure of the lubricant film which leads to boundary lubrication. Thus, it is important to have a good understanding of boundary lubrication behavior. In this paper the major tribological parameters that influence the boundary lubrication properties are evaluated. It is shown that disk roughness, hardness and normal load affect the friction and wear of metals in boundary lubrication. Also, the mechanism of surface damage is attributed to abrasion and wear particle interaction.

• 대한기계학회논문집B
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• 제22권9호
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• pp.1335-1348
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• 1998

Flow characteristics in transitional boundary layers on a flat plate were experimentally investigated under three different freestream conditions i. e. uniform flow with 0.1 % and 3.7% freestream turbulent intensity and cylinder-wake with 3.7% maximum turbulent intensity. Instantaneous streamwise velocities in laminar, transitional and turbulent boundary layers were measured by I-type hot-wire probe. For estimation of wall shear stresses on the flat plate, measured mean velocities near the wall were applied to the principle of Computational Preston Tube Method (CPM). Distributions of skin friction coefficients were reasonably predicted in all developed boundary layers. Intermittency profiles, which were estimated using Conditional Sampling Technique in transitional boundary layers, were also consistent with previously published data. It was predicted that the incoming turbulent intensity had more influence on transition onset point and transition process than freestream turbulent intensity existed just over the transition region. It was also confirmed that non-turbulent and turbulent profiles in transitional boundary layers could not be simply treated as Blasius and fully turbulent profiles.

• 한국조리학회지
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• 제18권5호
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• pp.16-32
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• 2012

본 연구의 목적은 외식프랜차이즈에서 본사의 영향전략이 가맹점의 영역초월행동에 어떠한 영향을 미치는지와, 본사의 영향전략이 가맹점의 영역초월행동에 미치는 인과관계에서 본사의 기업가지향성이 조절역할을 하는지, 및 본사의 기업가지향성이 가맹점의 영역초월행동에 어떠한 영향을 미치는지를 파악하는데 있다. 본 연구의 표본은 전국 외식프랜차이즈에서의 가맹점의 점주나 관리인이었으며 총 698부의 설문지를 회수하였다. 본 연구에서 사용된 통계분석방법은 빈도분석, 탐색적 요인분석, 신뢰도 분석, 위계적 회귀분석이었다. 통계분석 결과, 본사의 영향전략인 약속(${\beta}$=0.292), 위협(${\beta}$=-0.256), 권고(${\beta}$=0.200), 정보교환(${\beta}$=0.359), 요청(${\beta}$=-0.097), 법적소원(${\beta}$=-0.137)이 가맹점의 영역초월행동에 영향을 미쳤으며, 본사의 기업가지향성(${\beta}$=0.537)도 가맹점의 영역초월행동에 유의한 영향을 미치는 것으로 나타났다. 또한 본사의 기업가지향성은 약속측면(약속 x 본사의 기업가지향성; ${\beta}$=0.168)과 위협측면(위협 x 본사의 기업가지향성; ${\beta}$=-0.075)이 가맹점의 영역초월행동에 미치는 인과관계에서 조절효과를 가지는 것으로 나타났다. 이러한 결과를 바탕으로 한국의 외식프랜차이즈 가맹점들은 본사가 높은 기업가지향성을 가져 시장에서 긍정적인 성과를 획득하기 원하며, 동시에 영향전략에서 약속을 행하는 것을 선호하는 것으로 나타났다. 마지막으로 본 연구의 한계점과 미래연구의 방향이 서술되었다.

• 대한안전경영과학회지
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• 제11권2호
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• pp.179-185
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• 2009

This paper reviewed the relationship between boundary spanning behaviors and service quality, and the moderating effect of gender. Based on the responses from 204 employees in outdoor-food franchising system, hierarchical regression analysis showed that service delivery has positive relationships with all service quality factors, and external representation and internal influence have partly positive relationship with them. Gender appeared to have partly moderating effect on the relationship between only internal influence and service quality.

• 대한기계학회논문집A
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• 제25권2호
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• pp.304-311
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• 2001

The present work examines the influence of surface coating on the temperature and the thermo-mechanical stress field produced by friction due to sliding contact. A two-dimensional transient model of a layered medium submitted to a moving heat flux is prsented. A solution technique based on the boundary element method employing the multiregion technique is utilized. Results are presented showing the influence of coating thickness, thermal properties, Peclet number, and mechanical properties. It has been shown that the mechanical properties and thickness of coating have a significant influence on the stress field, even for low temperature increase. The effects of the ratios of shear modulus become more important for low temperature increase than the effects of the ratios of other mechanical properties.

• 한국지진공학회:학술대회논문집
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• 한국지진공학회 1998년도 춘계 학술발표회 논문집 Proceedings of EESK Conference-Spring 1998
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• pp.155-162
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• 1998

The influence of the dam-reservoir interaction on the seismic response of dams is studied. To represent the radiation of energy into the infinite region of the reservoir, a transmitting boundary is newly developed. The results obtained using the transmitting boundary is compared with abvailabel analytic solutions.

• 한국세라믹학회지
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• 제33권1호
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• pp.35-40
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• 1996

The influence of grain boundary on the electrical properties of WO3-doped SrTiO3 ceramics has been investi-gated. From the result resistivity and capacitance of grains and boundaries were obtained by employing impedance spectrocopy. And the temperature dependance of capacitance of WO3-doped SrTiO3. was influenced directly by the variation of grain boundary capacitance. It was also found by impedance spectroscopy that the dispersion frequency characteristics showed discernibly that the resistivity of the specimen varied with WO3 content.

• Structural Engineering and Mechanics
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• 제41권5호
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• pp.591-604
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• 2012

This paper provides an iteration approach for the solution of multiple notch problem, which is based on the complex variable boundary integral equation (CVBIE). The contours of notches are applied by some loadings. The source points are assumed on the boundary of individual notch and the displacements along the boundaries become unknowns to be investigated. After discretization of the BIE, many influence matrices are obtained. One does not need to assemble many influence matrices into a larger matrix. This will considerably reduce the work in the program. The displacements along the many boundaries can be obtained from an iteration. There is no limitation for the configuration of notches. Several numerical examples are provided to prove the efficiency of the suggested approach.

• 한국해양공학회지
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• 제26권5호
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• pp.55-62
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• 2012

In this paper, the rigid lid boundary condition is applied to simulate the influence of floating structures such as ships or pontoons, and the pressure term in both the momentum equations and continuity equation are modified. The pressure of a floating structure under the free surface is dependent on the draft of the structure, generally called a ship. If the free surface is covered by a floating structure, the free surface cannot move freely. The water level should be fixed, using a rigid lid boundary condition. This boundary condition is implemented by reducing the storage area of the grid cell with a factor between zero and one. The numerical model developed by Hong (2009) is verified through a comparison with experimental results, and the influence of the reduction factor is investigated using the verified numerical model.