• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.05a
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• pp.641-644
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• 2017

Usage of LTE(Long Term Evolution) technology is expanded to industrial an emergency service field beyond commercial communications of mobile internet focused on smartphone. In this paper, transmission performance of LTE technology be supplied to various service area is analyzed on the level of application traffics. Performance is evaluated with compter simulation based NS(Network Simulator)-2, CBR(Constant Bit Rate), VBR(Variable Bit Rate File) traffic is used as simulation target. Results and methods of this paper can be used for research and developmemt of LTE based networks.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.10a
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• pp.527-530
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• 2017

LTE-R(Long Term Evolution-Railway) based on LTE technology is expected to use core communication technology for high speed railway as one of standards for railway communications. In this paper, transmission performance of video traffic as an application is analyzed on LTE-R networks. Performance is evaluated with compter simulation based NS(Network Simulator)-2, open video traffic is used, RTP(Real Time Protocol) is used for transmission protocol. Results and methods of this paper can be used for research and developmemt of LTE-R networks.

• Proceedings of the Korean Information Science Society Conference
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• 2003.04d
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• pp.211-213
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• 2003

RED 파라미터를 가장 적합하게 설정할지라도 RED 라우터의 처리량(Throughput)이 TD 라우터 보다 획기적으로 향상되기는 매우 어려운 일이다 하지만 REO 라우터를 이용하여 TCP 커넥션들간의 페어니스(Fairness)와 페어니스 향상에 따른 전체 네트워크 이용률(Utilization)을 높일 수는 있다. 본 논문에서는 네트워크 상황에 따라 동적으로 RED 파라미터를 조절하면서 빠르게 안정적인 상태로 적응하는 진보된 RED 알고리즘인 ea-RED(Efficient Adaptive RED)의 성능을 네트워크 시뮬레이션 툴인 NS-2를 이용하여 TD. RED 알고리즘과 다양하게 실험하고 비교 분석한다. 이 실험을 통해 병목구간에서 혼잡이 심할 경우, ea-RED 라우터가 RED나 TD 라우터에 비해 큐를 효율적으로 사용하면서도 보다 높은 페어니스 인덱스 값을 갖는다는 점을 확인할 수 있다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.10a
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• pp.777-779
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• 2009

Study for VoIP in MANET is mainly focused on transmission performance or voice quality of VoIP traffic as single traffic. In this study, VoIP performance is analyzed of MANET which has several types of traffics. Diffserv scheme is used to process the traffics. It is showed that VoIP traffic performance is improved by differv scheme, as a result of analysis for VoIP and FTP traffic. Simulator, which is implemented with NS-2 package and VoIP patch, is used.

• Advances in concrete construction
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• v.10 no.5
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• pp.403-416
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• 2020

This study investigated the effect of alkaline activators - NaOH_aq (NH) (NH: 0-16 M) and Na₂SiO_3aq (NS) (NS/NH: 0-3.5) in the synthesis of silico-manganese fume (SMF) and ground blast furnace slag (BFS) blended alkali-activated mortar (AASB). The use of individual activator was ineffective in producing AASB of sufficient fresh and hardened properties, compared to the synergy of both activators. This may be attributed to incomplete dissolution and condensation of oligomers required for gelation of the binder. An inverse relationship was noted among the fresh properties and the NH concentration or NS/NH ratio. This was influenced by the dissolution and condensation of silicate monomers under polymerization process. The maximum 28-day strength of ~45 MPa, setting time of 60 min and flow of 182 mm was obtained with the use of combined activators (10M-NH and NS/NH=2.5). The combined activators at NS/10M-NH=2.5 constituted SiO₂/Na₂O, H₂O/Na₂O and H₂O/SiO₂ molar ratio of 1.61, 17.33 and 10.77, respectively. This facilitated the formation of C-S-H, C/K-A-S-H and C-Mn-S-H in the framework together with an increase in the crystallinity due to more silicate re-organization within the aluminosilicate chain. On comparison of the high concentrated with mild alkali synthesized product, it revealed that the concentration of OH^- and Si monomers together with alkali metals influenced the dissolution of precursors and embedment of the constituent elements in the polymeric matrix. These factors eventually contributed to the microstructural densification of the mortar prepared with NS/10M-NH=2.5 thereby enhancing the compressive strength.

• Journal of Sasang Constitutional Medicine
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• v.17 no.1
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• pp.130-141
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• 2005

1. Objectives The present study was carried out to investigate the effects of Chungpyesagan-tang on the $CCI_4-induced$ Liver Damage in Rats. 2. Methods Sprague-Dawley rats were devided into 5 experimental groups : Normal, $NS+CCI_4(Solid$ extract of $CCI_4$ injection group after Normal Saline feed), $CP+CCI_4(Solid$ extract of $CCI_4$ injection group after Chungpyesagantang feed), $CCI_4+NS(Nomal$ Saline feed group after $CCI_4$ injection), $CCI_4+CP(Solid$ extract of Chungpyesagantang feed group after $CCI_4$ injection). Biochemical assays for serum enzyme activities such as AST, ALT, ALP, BUN, Creatinine, Uric Acid, Total Protein, Albumin, Total Cholesterol, Triglyceride, Glucose, and mRNA Revelation of Cytochrome p450 and activities such as LPO(Lipid Peroxidation), GSH(Glutathione), GST(Glutathione-S- Transferase), Glutathione Reductase, Glutathione Peroxidase, SOD(Superoxide Dismutase), Catalase, Hydroxyproline, and ${\beta}-Glucuronidase$ were performed. 3. Results 1) $CP+CCI_4$ showed significantly lower relation of Cytochrome p450 than $NS+CCI_4$. 2) As to LPO Hydroxyproline, $CCI_4+CP$ showed significantly lower activity than $CCI_4+NS$. 3) As to GSH GST Glutathione Peroxidase Catalase, $CP+CCI_4$ showed higher activity than $NS+CCI_4$, $CCI_4+CP$ showed significantly higher activity than $CCI_4+NS$. 4) As to Glutathione Reductase SOD, $CCI_4+CP$ showed significantly higher activity than $CCI_4+NS$. 5) As to ${\beta}-Glucuronidase$, $CP+CCI_4$ showed signficantly lower activity than $NS+CCI_4$. 4. Conclusions Chungpyesagantang has the recovering effects on the $CCI_4-induced$ Liver Damage.

• BMB Reports
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• v.38 no.2
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• pp.151-160
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• 2005

By a cDNA array representing 2308 signal transduction related genes, we studied the expression profiles of HeLa cells stably transfected by Hepatitis C virus nonstructural protein 4B (HCV-NS4B). The alterations of the expression of four genes were confirmed by real-time quantitative RT-PCR; and the aldo-keto reductase family 1, member C1 (AKR1C1) enzyme activity was detected in HCV-NS4B transiently transfected HeLa cells and Huh-7, a human hepatoma cell line. Of the 2,308 genes we examined, 34 were up-regulated and 56 were down-regulated. These 90 genes involved oncogenes, tumor suppressors, cell receptors, complements, adhesions, transcription and translation, cytoskeletion and cellular stress. The expression profiling suggested that multiple regulatory pathways were affected by HCV-NS4B directly or indirectly. And since these genes are related to carcinogenesis, host defense system and cell homeostatic mechanism, we can conclude that HCV-NS4B could play some important roles in the pathogenesis mechanism of HCV.

• The Korean Journal of Pain
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• v.24 no.3
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• pp.131-136
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• 2011

Background: Pregabalin is an anticonvulsant and analgesic agent that interacts selectively with the voltage-sensitive-$Ca^{2+}$-channel alpha-2-delta subunit. The aim of this study was to evaluate whether the analgesic action of intrathecal (IT) pregabalin is associated with KATP channels in the rat formalin test. Methods: IT PE-10 catheters were implanted in male Sprague-Dawley rats (250.300 g) under inhalation anesthesia using enflurane. Nociceptive behavior was defined as the number of hind paw flinches during 60 min after formalin injection. Ten min before formalin injection, IT drug treatments were divided into 3 groups: normal saline (NS) $20\;{\mu}l$ (CON group); pregabalin 0.3, 1, 3 and $10\;{\mu}g$ in NS $10\;{\mu}l$ (PGB group); glibenclamide $100\;{\mu}g$ in DMSO $5\;{\mu}l$ with pregabalin 0.3, 1, 3 and $10\;{\mu}g$ in NS $5\;{\mu}l$ (GBC group). All the drugs were flushed with NS $10\;{\mu}l$. Immunohistochemistry for the $K_{ATP}$ channel was done with a different set of rats divided into naive, NS and PGB groups. Results: IT pregabalin dose-dependently decreased the flinching number only in phase 2 of formalin test. The log dose response curve of the GBC group shifted to the right with respect to that of the PGB group. Immunohistochemistry for the $K_{ATP}$ channel expression on the spinal cord dorsal horn showed no difference among the groups 1 hr after the formalin test. Conclusions: The antinociceptive effect of pregabalin in the rat formalin test was associated with the activation of the $K_{ATP}$ channel. However, pregabalin did not induce $K_{ATP}$ channel expression in the spinal cord dorsal horn.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.25 no.12
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• pp.1251-1257
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• 2014

In this paper, a 6~13 GHz ultra high speed frequency synthesizer having minimum 30 kHz step size and minimum 500 ns frequency settling time is proposed. In order to obtain fast settling time, fine resolution, and good phase noise performance, wideband output frequencies were synthesized based on DDS(Direct Digital Synthesizer) and analog direct frequency synthesis technology. The phase noise performance of wideband frequency synthesizer was estimated by the superposition theory and its results were compared with measured ones. The measured frequency settling time was below 500 ns, phase noise was below -106 dBc @ 10 kHz at 13 GHz, and frequency accuracy was measured below ${\pm}2kHz$.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.19 no.2
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• pp.174-180
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• 2008

The pulsed amplifier which switches the main supply voltage of RF amplifier according to input pulse signal has good efficiency and low noise level between pulses. And it has simple structure because it doesn't need a pulse modulator at input port. The pulsed amplifier using the conventional switching circuit has slow fall time compared to rise time. We proposed the novel switching circuit for improving the fall time of pulsed amplifier The proposed switching circuit is implemented by replacing FET of conventional circuit with BJT. As a result of appling this circuit to RF pulsed amplifier, the rise and fall time are 5.7 ns and 21.9 ns at 27 dBm output power, respectively.