• Journal of the Korean Institute of Gas
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• v.13 no.4
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• pp.1-7
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• 2009

In recent years, the needs for more fuel-efficient and lower-emission vehicles have driven to use the alternative fuel of LPG(Liquefied Petroleum Gas) which is able to meet the more stringent legislations without many modifications to current engine. LPLi (Liquid Phase LPG Injection) system (the 3rd generation LPG injection system) is the core technology to produce power equivalent to a gasoline engine with less emissions. The LPG fuel pump can supply the compressed LP gas in the liquid phase to engine. The fuel filter is attached in the fuel pump to eliminate the remnants in the liquid phased LP gas and the performance of blowoff flow for a pump can be varied with various filters. In this study, experiments were conducted to investigate the performance and efficiency of the impeller type LPG fuel pump under various filter types of microfiber, double mesh and external filter. And blowoff flow for a LPG fuel pump was measured according to the temperature of the fuel.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.10
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• pp.1443-1453
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• 2010

We simulated the roughing train of the rod mill of SEAH BESTEEL Inc. using finite element method to inhibit surface cracks initiation on workpiece. We designed 2nd pass (square roll) and applied to this roll in the roughing train of the rod mill. Also, we proposed new pass schedule, which changed roll gap of 3rd and 4th groove by using finite element method. We used shear damage model, which is dependent on shear stress ratio and compared the number of damaged elements on workpiece. A damaged element means surface crack. Consequently, after 2nd pass (square roll) is changed, the error rate decreased by 1.43% when compare to that of the old groove. And the number of damaged elements in the new pass schedule decreased by 37.6%, which is less than present pass schedule.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.4
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• pp.828-834
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• 2009

To get a better profit, standalone mobile game market shifts network-based mobile game. Currently, most of the game platform are separated into mobile to mobile, desktop to desktop, and console to console. Multi platform network game has a diverse problems including consistency control, object management technique, and bandwidth inconsistency. n this paper, we will introduce a multi-platform arcade game "Push-Push", which is played on desktop to mobile environment. The game guarantees realtime play between heterogeneous machine users and game item sharing between two platforms. e will focus n the issues of the 3rd generation multi platform games and propose some techniques or solving these problems. Our server database is implemented on MS SQL database, also the desktop programming tool is Visual Basic, and WIPI(Wireless Internet Platform or Interoperability) as a mobile platform.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.39 no.7
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• pp.46-56
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• 2002

In this paper, we describe a hardware-software co-verification methodology and environment in developing a mobile station modem chip for cdma2000 1x which is one of the 3rd generation mobile communication standards. By constructing an efficient co-verification environment for a register-transfer-level hardware model and a physical-layer software model combining a channel link simulator and a versatile test-bench, we can drastically reduce both time and cost for developing a complex three-million-gate class system integrated circuit.

• Journal of Advanced Marine Engineering and Technology
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• v.31 no.1
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• pp.26-33
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• 2007

The intake swirl motion, as one of dominant effects for an engine combustion. is very effective for turbulence enhancement during the compression process in the cylinder of 2-valve engine. Because the combustion flame speed is determined by the turbulence that is mainly generated from the mean flow of the charge air motion in intake port system. This paper describes the experimental results of swirl flow and combustion characteristics by using the oil spot method and back-scattering Laser Doppler velocimeter (LDV) in 2-valve single cylinder transparent LPG engine using the liquid phase LPG injection. For this. various intake port configurations were developed by using the flow box system and swirl ratios for different intake port configurations were determined by impulse swirl meter in a steady flow rig test. And the effects of intake swirl ratio on combustion characteristics in an LPG engine were analyzed with some analysis parameters that is swirl ratio. mean flow coefficient, swirl mean velocity fuel conversion efficiency. combustion duration and cyclic variations of indicated mean effective pressure(IMEP). As these research results, we found that the intake port configuration with swirl ratio of 2.0 that has a reasonable lean combustion stability is very suitable to an $11{\ell}$ heavy-duty LPG engine with liquid phase fuel injection system. It also has a better mean flow coefficient of 0.34 to develope a stable flame kernel and to produce high performance. This research expects to clarify major factor that effects on the design of intake port efficiently with the optimized swirl ratio for the heavy duty LPG engine.

• YAKHAK HOEJI
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• v.48 no.2
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• pp.147-152
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• 2004

A wide variety of cancer chemotherapeutic agents have been shown to induce programmed cell death (PCD, APOPTOSIS) in various tumor cell lines in vitro. cis-Malonato [(4R,5R)-4,5-bis(aminomethyl)-2-isoprpopyl-1,3-dioxolane] platinum(II) (heptaplatin), which is a new drug approved by KFDA in 1999, in a novel platinum-based antitumor agent with clinical potential against stomach cancer and the 3rd generation of the cisplatin. This study was performed to know how heptaplatin and cisplatin and sunpla (mixture of heptaplatin and mannitol) affect on SK-MEL-28 cell line, and how they induce the apoptosis. At EM analysis, the morphology of the cell was changed by treatment of the cisplatin, heptaplatin and sunpla. Apoptotic body formed around plasma membrane, and chromatin condensation represented in nucleus. This phenomenon is one of the characteristic of the apoptosis. The DNA of SK-MEL-28 cell line truncated by cisplatin and sunpla treatment was identified on 2% agarose gel electrophoresis. TUNEL assay was performed to know whether SK-MEL-28 cell die as apoptosis or necrosis by cisplatin, heptaplatin and sunpla. At this result, fluorescence intensity increased according to increase of time and concentration. Therefore, it was identified that cislatin, heptaplatin and sunpla induced apoptosis. Fas expressed on SK-MEL-28 cell membrane by cisplatin, heptaplatin and sunpla was identified by using flow cytometer and the expression of bcl-2(anti-apoptotic gene) decreased according to increase of concentration of the cisplatin, heptaplatin and sunpla. Cisplatin, heptaplatin and sunpla induced apoptosis against SK-MEL-28 cell line, and the apoptotic mechanism was identified as Fas-mediated apoptosis and decreased bcl-2 expression.

• The Journal of Korean Association of Computer Education
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• v.14 no.4
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• pp.11-20
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• 2011

Recently, the interests of mobile GIS(Geographic Information System) technology is increasing with the spread of wireless network, the improvement of mobile device's performances and the growth of demands about mobile services. If we refer mobile GIS system classified as 3rd generation with the success of Web 2.0, it is suggested that supplies of information from the server side couldn't enhance users' participations and the usage of service. In this study, we suggested the model of GIS 2.0 application based on Google map for Android smart-phones, which users could make, save and share information using photos and text by themselves. We were able to grasp the expectation of GIS 2.0 by expert assessment of this application and got to the core of conditions and implications for the success of GIS 2.0.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.9A
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• pp.1031-1038
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• 2004

The call admission control algorithm of hybrid scheme is proposed to enhance the QoS(quality of service) of attempted multimedia calls. In the initial stage of 3rd generation multimedia services networks, the major limitations include the small sefyice coverage and the limited radio link capacity. Because the initial massive deployment of network elements such as base stations, base station controllers, and mobile switching centers is restricted to populated areas and the other areas should be covered with the fewer network elements, the radio channel resources are hmited and coverage network is supposed to be established. Therefore the QoS of multimedia services is expected to be severely degraded when tentative traffic hot spot occurs frequently. Thus, the blocking probability of attempted calls mcreases when relatively large number of users try to place multimedia calls in a hot spot area of the wireless networks. In this situation, the proposed hybrid scheme can mitigate the degradation of the QoS of multimedia services by using the available radio channels of the neighboring cells.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.32 no.4 s.59
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• pp.219-225
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• 2006

In this study, we evaluated anti-oxidation, whitening and anti-inflammatory effects of Elsholtzia ciliata extract for use as the cosmeceuticals. Elsholtzia ciliata extracts (30, 70 and 100% methanol extract) exhibited a significant tree radical scavenging effect (up to 80% over 0.025% concentration of 30 and 70% methanol extract, over 0.01% concentration of 100% methanol extract) against DPPH radical generation and showed a significant inhibitory effect (up to 80% over 0.1% concentration) on melanin synthesis in B-16 Melanoma cells. We separated 4 fractions from Elsholtzia ciliata extract (70% methanol extract) by MPLC. The 1st, 2nd, and 3rd fractions showed anti-oxidation (DPPH radical scavenging activity and suppressive effect on Mn-SOD), whitening(inhibitory effect on melanin synthesis) and anti-inflammatory (suppressive effects on $IL-1{\alpha}$, IL-6, COX-2, and total NO synthesis) effects.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.32 no.4 s.59
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• pp.249-255
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• 2006

In this study, we evaluated anti-oxidation, whitening and anti-inflammatory effects of Ardisia crenata for use as the cosmeceuticals. Ardisia crenata extract (70% MeOH) showed a significant free-radical scavenging effect (up to 90% over at the concentration of 0.01 %) against DPPH radical generation and showed a significant inhibitory effect (up to 50% over at the concentration of 0.05 %) on melanin synthesis in B16 meanoma cells. We separated 5 fractions from Ardisia crenata extract (70% MeOH) by MPLC. The 3rd, 4th, and 5th fractions showed the anti-oxidation (DPPH radical scavenging activity and supressive effect on Mn-SOD), whitening (inhibitory effect on melanin synthesis) and anti-inflammatory (supressive effects on $IL-1{\alpha}$, IL-6, COX-2 and total NO synthesis) effects.