• Journal of Ginseng Research
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• v.14 no.3
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• pp.364-372
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• 1990

This experiment was performed to investigate the effects of ginseng saponin fractions (total saponin, triol saponin. diol saponin) and lipopolysacrharide (LPS) on the tllmoricidal activity of macrophage. The ginseng saponin fractions had little effect on the tumoricidal activity of macrophage (less than 10%). When the ginseng saponin fractions were treated with LPS, the effects of tumoricidal activation of macrophage increased a relatively high percent, and the total saponin and triol saponin (20-35%) were ulore effectual than diol saponin (15-25%). The effects of ginseng saponin and LPS on the tumoricidal activity of macrophage were mediated by the induction of macrophage-release factor(5) which has(have) the capacity of tumor cell killing. And the quantity of the (actors) was(were) increased by the contact of macrophage with tumor cell.

• 한국태양에너지학회:학술대회논문집
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• 2008.04a
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• pp.68-74
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• 2008

This paper describes the causes and effects that have influence on thermoelectric generation. If heat transfer is unequal to thermoelectric modules, we could not get the maximum thermoelectric power. So, by experiment, we analysed the differences of power generation according to the state of the contact between thermoelectric module and heat source. And with the variation of heat transfer area, the generated power was analysed also. Using the experimental results we proposed a thermoelectric generation system.

• Journal of the Semiconductor & Display Technology
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• v.5 no.2 s.15
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• pp.37-39
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• 2006

We employed in-situ spectroscopic ellipsometry(SE) and imaging ellipsometry(IE) to study the interaction of water and photoresist(PR) in 193 immersion lithography. Real time measurement of SE showed thickness increase when PR was immerged in water indicating swelling effect. From the temporal evolution we could observe its reaction-limited behavior. Meanwhile, IE could identify the modification of PR surface by contact of water even for a short period of a second.

• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.63-64
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• 2006

The solid state dye-sensitized solar cells (DSSCs) employing polymer electrolytes show high overall energy conversion efficiency as high as 4.5 % at 1 sun conditions. The improved efficiency may be primarily due to the enlarged interfacial contact area between the electrolyte and dyes in addition to the increased ionic conductivity, which were done by utilizing liquid oligomers, followed by in situ self-solidification, to form the solid DSSCs: "Oligomer Approach". The effect of the charge transfer resistance at the counter electrode side on the efficiency has also been investigated.

• Proceedings of the Korean Vacuum Society Conference
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• 1997.07a
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• pp.34-34
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• 1997

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 1998.04a
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• pp.91-96
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• 1998

In recent years, the tribological behavior of coated ceramic material has been the topic of much interest. Particularly, the understanding of the tribological performance of thin film under light load is important for potential applications in MEMS. In this work under light load and low speed, the tribological behavior of coated silicon was investigated. The results show that both adhesive and abrasive wear occur depending on the sliding condition. Also the effect of humidity on friction was influenced by the apparent ares of contact between the two surfaces. Finally, undulations on the silicon wafer were found to be effective in trapping wear particles.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 1997.04a
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• pp.176-180
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• 1997

Evaluating an optimum seal design to minimize leakage is concerned in the aspect of flow control. Flow is characterized into five categories according to its leakage path. Effect of geometry and leakage path are evaluated according to variation of sealing geometry. To simulate an oil jet or oil mist type high speed spindle lubrication, the working fluid is regarded as two phases that are mixed flow of oil phase and air phase. Both of the turbulence and the compressible flow model were introduced in CFD(Computational Fluid Dynamics) analysis. This offers a methodological way of enhancement seal design for high speed spindle.

• Tribology and Lubricants
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• v.29 no.1
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• pp.27-32
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• 2013

This study examined the effects of surface roughness in the mixed lubrication regime of smooth and rough surfaces for roller bearings. The average flow model was adopted for interaction between the flow rheology of the lubricant and the surface roughness. The average Reynolds equation and related flow factor that describes the coupled effects of surface roughness and flow rheology, the viscosity-pressure and density-pressure equations, the elastic deformation equation, and the force balance equation were solved simultaneously. The results showed that the effects of surface roughness on the film thickness and pressure distribution should be considered, especially in elastohydrodynamic lubrication contact problems.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2001.04a
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• pp.647-650
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• 2001

In case of bent axis type axial piston hydraulic pump or motor, hydrostatic bearing used to achieve the lubrication effect on the mechanical sliding contact areas between the following pairs ; piston shoe and swash plate, valve plate and cylinder block, piston and cylinder block, etc. In this research, we designed two pairs of spherical ball joint in witch connecting rod piston end. The one is not hydrostatic bearing, the other is designed with spherical hydrostatic bearing in point of view minimum pumping power loss. By varying supply pressure on the piston, we can know that it is possible to reduce the friction torque by using hydrostatic bearing designed one. Finally, by comparing the results of driving torque between the two models, it was verified that the spherical hydrostatic bearing is well designed.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.11a
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• pp.670-673
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• 2000

This paper attempt analysis and computer simulation of dynamics of a set of dual multi-joint fingers with soft-deformable tips which are grasping. Firstly, a set of differential equation describing dynamics of the fingers and object together with geometric constraint of tight area-contacts is formulated by Euler-Lagrange's formalism. Secondly, problems of controlling both the internal force and the rotation angle of the grasped object under the constraints of area-contacts of tight area-contacts are discussed. The effect of geometric constraints of area-contacts on motion of the overall system is analyzed and a method of computer simulation for overall system of differential-algebraic equations is presented. Finally, simulation results are shown and the effects of geometric constraints of area-contact is discussed.