• Transactions of the Korean Society of Mechanical Engineers A
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• v.36 no.11
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• pp.1391-1397
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• 2012

A cam ring gear (CRG) system based on a hypotrochoid curve consists of a pinion with roller teeth and its conjugated internal CRG. In this study, we investigated contact forces, contact stresses, and load stress factors to predict the surface pitting life using an exact CRG profile by introducing the profile modification coefficient. The results show that the pitting life can be extended significantly by increasing the profile modification coefficient without any other change of parameters in the CRG system.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.8B
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• pp.745-756
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• 2006

The general packet filtering system using TCAM has some limitations such as range and negation rules filtering, so this paper proposes efficient searching schemes than existing methods. CRG(Converting Range rules using Gray code) algorithm, in the case of range rules, that takes advantage of the gray code and TCAM characteristics to save a number of TCAM entries is proposed, and a nTCAM(TCAM with negation) architecture for negation rules is proposed, implemented using a FPGA design tool, and verified through the wave simulation. According to the simulation with the SNORT rules, the CRG algorithm and nTCAM save TCAM entries about 93% in IPv4 and 98% in IPv6 than the existing method.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.23 no.2
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• pp.194-198
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• 2014

In recent years, RGM(roller gear mechanism) systems, wherein one of the gears of a meshing gear pair is replaced with pins or rollers, have been reintroduced, which is a consequence of, and therefore a reflection of, the rapid advances made in manufacturing technology. Three RTG(roller track gear) systems for arbitrary path transportation (e.g., L-, O-, U-, and S-shaped tracks) were constructed using two out of three RGM systems, namely, the CRP(cam rack pinion), CRG(cam ring gear), and RPG(roller pinion gear) systems, and are introduced in this paper. We also present three ways to prevent the intersection and non-contact phenomena at the teeth in the vicinity of the conversion point between two joined RGM systems.

• The Journal of Internal Korean Medicine
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• v.28 no.4
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• pp.886-895
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• 2007

Objective : The immune system is a complex of systems, all of which work together to clear infection from the body. In Korea, red ginsenghas been one of the herbs most widely used to enhance the immune system for thousand of years. More recently, red ginseng has been reported to have many positive effects on the immune system. The purpose of this study was evaluate the effects of Korean red ginseng and Chinese red ginseng on IgG, IgM, and IgA, using immunoglobulin productivity assay. Methods : Male SD rats were separated into 3 groups. We administered Korean red ginseng (KRG) to one group and Chinese red ginseng (CRG) to another, with normal saline for the Control group consecutively and orally for 3 months. The dose of red ginseng was 500mg per day, as a powder with soluble water. Immunoglobulin levels from spleen cell were estimated by ELISA kit. Results : In immunoglobulin productivity assay (cell), the IgG level of the KRG group significantly increased but there was no significant difference in the IgG of the CRG group. The IgM level of the KRG group significantly increased stimulated with PWM. When it was unstimulated, the level of IgM in KRG and CRG increased together. The IgA level of the KRG group significantly increased when it was stimulated with PWM and unstimulated. Conclusion : According to the above results, oral administration of red ginseng for 3 months is considered useful for immunomodulatory effect, and Korean red ginseng may be superior to Chinese red ginseng in that effect.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2012.10a
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• pp.715-716
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• 2012

• Transactions of the Korean Society of Mechanical Engineers A
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• v.38 no.8
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• pp.881-886
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• 2014

The purpose of three-dimensional (3-D) metal printing using 5-axis is to deposit metal powder by changing the orientation of the deposited structure to be built for the overhang or undercut feature on part geometry. This requires a complicated preprocess functionality of providing three dimensionally sliced layers to cover the required part geometry. This study addresses the overhang/undercut problem in 3-D metal printing and discusses a possible solution of providing 3-D layers to be built using the DMT(R) machine.