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Gwangju, South Korea

Gwangju National University of Education is a national university located in Gwangju, South Korea. Wikipedia.

Kim Y.-H.,Gwangju National University of Education | Kim Y.-H.,Sunchon National University | Lee S.-K.,Sunchon National University | Koh J.-G.,Sunchon National University | Koh J.-G.,Korean Institute of Information Scientists and Engineers
International Journal of Smart Home | Year: 2013

Ethernet is one of the most widely-deployed and utilized local-loop networking technology across the world, and IEEE 802.3az working group has confirmed EEE(Energy Efficient Ethernet) standard proposal based on LPI (Low Power Idle) mode. This paper suggests Synchronizing Adaptive LPI Control Mechanism in a bid to improve the energy efficiency between interfacing terminals on Ethernet network and the Ethernet switches. This mechanism determines ON and OFF durations of consecutive cycles based on the measured incoming traffic quantities from the terminals. It keeps transferring cycle information which is the most proximate to the traffic bursting cycles while resting in idle is left to LPI mode by conveying the corresponding information to the switch. This paper conducts the performance evaluations with simulations on Poisson distribution traffic and burst traffic. The result has shown that the suggested mechanism in this paper improves the overall performance by reducing the energy consumption rate compared to the existing mechanism, keeping the average packet delay to the similar state as before ©2013 SERSC.

Koh Y.-K.,Chonnam National University | Oh K.-H.,Chonnam National University | Youn S.-T.,Chonnam National University | Kim H.-G.,Gwangju National University of Education
Journal of Marine and Island Cultures | Year: 2014

The island area has well preserved geodiversity and biodiversity due to minimal exposure to humans. UNESCO has maintained things and sites with geological importance as geoheritage. Although a number of natural heritages and national parks exist on 'geological' bases, geodiversity concepts are less concerned about biodiversity due to a lack of recognition. Recently, geotourism linked to geodiversity has been activated in worldwide and geopark programs have been established in many countries. These precedents offer good chances for the use of geoheritage and preservation of geodiversity. Geopark programs can lead to the preservation of geodiversity and public geoeducation through tour of geosites. In particular, it is necessary to understand oceanic nature and culture including islands through geoeducation programs used by geodiversity of islands. Gwanmae Island is the first luxury village named by the Korea National Park Service. This study suggests plans of geotourism by geosites with noticeable geodiversity of the island. © 2014 .

Kim Y.G.,Gwangju National University of Education | Lee H.M.,CERN
Journal of High Energy Physics | Year: 2011

We consider sneutrino inflation and post-inflation cosmology in the singlet extension of the MSSM with approximate Peccei-Quinn(PQ) symmetry, assuming that supersymmetry breaking is mediated by gauge interaction. The PQ symmetry is broken by the intermediate-scale VEVs of two flaton fields, which are determined by the interplay between radiative flaton soft masses and higher order terms. Then, from the flaton VEVs, we obtain the correct μ term and the right-handed(RH) neutrino masses for see-saw mechanism. We show that the RH sneutrino with non-minimal gravity coupling drives inflation, thanks to the same flaton coupling giving rise to the RH neutrino mass. After inflation, extra vector-like states, that are responsible for the radiative breaking of the PQ symmetry, results in thermal inflation with the flaton field, solving the gravitino problem caused by high reheating temperature. Our model predicts the spectral index to be ns ? 0.96 due to the additional efoldings from thermal inflation. We show that a right dark matter abundance comes from the gravitino of 100 keV mass and a successful baryogenesis is possible via Affleck-Dine leptogenesis. © 2011 SISSA.

Kim Y.G.,Gwangju National University of Education
Modern Physics Letters A | Year: 2011

We investigate a squark cascade decay, i.e. q̄L→qx̄ 2→qZx̄1→qllx̄1. It is shown that some information on the mass and spin of the supersymmetric particles might be obtained from the cascade decay chain at the Large Hadron Collider at CERN. © 2011 World Scientific Publishing Company.

Sohn K.H.,Gwangju National University of Education | Kim M.K.,Gimcheon College | Lee S.M.,Gimcheon College | Ji B.C.,Gimcheon College | And 3 more authors.
Fibers and Polymers | Year: 2011

Triphenyl phosphate (TPP) is well known to be one of the most effective flame retardants for acrylonitrile-butadiene-styrene copolymer (ABS) and its blending resins, such as polycarbonate (PC)/ABS, among various phosphorous-based compounds. However, TPP can also play a role as a plasticizer, which decreases the mechanical properties of PC/ABS resins at high temperature. Furthermore considerable amount of TPP has to be evaporated during molding process due on its much lower evaporation temperature. To overcome these shortcomings, we tried to immobilize TPP by grafting on butadiene moiety of ABS. FT-IR analysis of prepared TPP-grafted ABS (ABS-g-TPP) comparing with TPP, ABS and their blend confirmed that chemical reactions happened between TPP and ABS resins and it was attributed to the graft reaction of TPP onto butadiene moieties. Prepared ABS-g-TPP resins were blended with PC at various compositions to be prepared as testing specimens by injection molding. The physical characteristics such as mechanical properties, thermal stability, and flame retarding properties of the PC/ABS-TPP graft copolymer were analyzed through Vicat softening temperature, IZOD impact strength, transmission electron microscope, and UL94 flame retardation tests. Results showed that PC/ABS-g-TPP resin takes better thermomechanical properties than the existing PC/ABS resins at relatively low additional TPP amounts. © 2011 The Korean Fiber Society and Springer Netherlands.

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