• Title/Summary/Keyword: LFC

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The Experimental Study on anti-inflammatory Effects of Kagamsunbanghwalmyungeum(KSBH) (가감선방활명음(加減仙方活命飮)의 항염작용(抗炎作用)에 대한 실험적(實驗的) 연구(硏究))

  • Shin, Sun-Mi;Kim, Soo-Min;Kim, Eui-Il;Lee, Jung-Eun;Yoo, Dong-Youl
    • The Journal of Korean Obstetrics and Gynecology
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    • v.20 no.1
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    • pp.125-143
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    • 2007
  • Purpose : This study was to investigate the anti-inflammatory effects of Kagamsunbanghwalmyungeum(KSBH) which has been medicated the patient such as breast abscess. Methods : In the study of anti-inflammatory effects, KSBH was investigated using cultured cells and a murine models. As for the parameters of inflammation, level of several inflammatory cytokines and chemical mediators which are known to be related to inflammation were determined in mouse lung fibroblast cell(mLFC) and RAW 264.7 cells. Results : The cytotoxicity on mouse lung fibroblast cells(mLFC) was not served at all concentration of KSBH. KSBH in RAW264.7 cell inhibited IL-l${\beta}$, IL-6, TNF-${\alpha}$, COX-2 and NOS-II mRNA genes expression in a concentration-dependent manner, and specially inhibited NOS-II production very significantly at 100${\mu}$g/ ml. KSBH inhibited NO production significantly in a concentration-dependent manner and ROS production in a concentration-dependent manner. KSBH inhibited IL-l${\beta}$, IL-6 and TNF-${\alpha}$ production significantly in serum of acute anti-inflammation-induced mice. KSBH increased the survival rate from the 3rd day on LPS-induced lethal endotoxemia. Conclusion : These results suggest that Kagamsunbanghwalmyungeum(KSBH) can be useful in treating a lot of women mammary diseases caused by inflammation such as breast abscess.

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Surface Characteristics of Fouling Resistant Low-Pressure RO Membranes (상업용 내오염성 저압 RO막의 표면 특성 분석)

  • Hong, Seungkwan;Taylor, James;Norberg, David;Lee, Jinwoo;Park, Chanhyuk;Kim, Hana
    • Journal of Korean Society on Water Environment
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    • v.22 no.1
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    • pp.1-6
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    • 2006
  • In this study, five commercially available fouling resistant low-pressure RO membranes were investigated for the treatment of seasonally brackish surface water with high organic content (${\approx}24mg/L$). The membranes investigated are LFC-1 (Hydranautics), X20 (Trisep), BW30FR1 (FilmTec), SG (Osmonics), and BE-FR (Saehan). The results of surface characterization revealed that each of these membranes has one or two unique surface characteristics to minimize the adherence of the fouling materials to the membrane. Specifically, the LFC1 membrane features a neutral or low negative surface to minimize electrostatic interactions with charged foulants. The X20, on the other hand, shows a highly negatively charged surface, and thus, is expected to perform well with feed waters containing negatively charged organics and colloids. The BW30FR1 exhibits a relatively neutral and hydrophilic surface, which could be beneficial for lessening organic and/or biofouling. The SG membrane has a smooth surface that makes it quite resistant to fouling, particularly for colloidal deposition. Lastly, BE-FR membrane demonstrated a medium surface charge and a slightly higher hydrophobicity. In the pilot study, all of the four membranes experienced a gradual increase in MTC (water mass transfer coefficient or specific flux) over time, indicating no fouling occurred during the pilot study. The deterioration of permeate water quality such as TDS was also observed over time, suggesting that the integrity of the membranes was compromised by the monochloramine used for biofouling control.

Anti-inflammatory Effect of Haingkyunghonghwatang in cultured RAW264.7 cells and murine models of inflammation (RAW264.7세포주와 염증생쥐모델에서 항염증(抗炎症) 작용(作用)에 대한 행경홍화탕(行經紅花湯)의 효과(效果))

  • Min, Byung-Ho;Yoo, Dong-Youl
    • The Journal of Korean Obstetrics and Gynecology
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    • v.18 no.4
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    • pp.36-53
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    • 2005
  • Purpose : The Purpose of this research was to investigate the effects of Haingkyunghonghwatang (HKHHT) on anti-inflammatory effects. Methods : As for the parameters of inflammation, levels of several inflammatory cytokines and chemical mediators were determined in mouse lung fibroblast cells(mLFC) and RAW264.7 cells. Also, changes in pathological features by drug treatment were investigated in the in vivo edema-induced rats by carrageenin/arachidonic acid or in the colitis-induced mice by DSS treatment. Results : The cytotoxicity of HKHHT on mLFC and RAW264.7 cells wasn't observed at 100, 50, 10, and $1{\mu}g/ml$ of The treatments. $IL-1{\beta}$, IL-6 and NOS-II mRNA expression of RAW264.7 cells was inhibited by The treatments in a dose-dependent manner. HKHHT treatment of RAW264.7cells(HtRc) inhibited $TNF-{\alpha}$ and COX-2 mRNA expression. HtRc significantly inhibited IL-6 and NO production. HtRc inhibited ROS production. HKHHT inhibited rat's paw edema induced by carrageenin or arachidonate treatment in all concentrations examined. The body weight and colon length of colitis-induced mice were recovered to a normal level by DSS treatment. Clinical disease levels were significantly improved compared to the control animals. HKHHT treatment of colitis-induced mice(HtCm) significantly increased hematological values such as WBC and RBC counts, Hgb and HCT levels, but decreased PLT values. HtCm decreased IL-6 and $TNF-{\alpha}$ production significantly HtCm significantly increased CD3+(T) cell counts. In contrast, HKHHT treatment decreased CD19+ B cell counts and CD3+/CD69+ significantly, and also decreased B/T ratio (%) though not significant. Conclusion : These results indicated that HKHHT could be used for treating diverse female diseases caused by the inflammation.

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Uniform Fractional Band CAC Scheme for QoS Provisioning in Wireless Networks

  • Rahman, Md. Asadur;Chowdhury, Mostafa Zaman;Jang, Yeong Min
    • Journal of Information Processing Systems
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    • v.11 no.4
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    • pp.583-600
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    • 2015
  • Generally, the wireless network provides priority to handover calls instead of new calls to maintain its quality of service (QoS). Because of this QoS provisioning, a call admission control (CAC) scheme is essential for the suitable management of limited radio resources of wireless networks to uphold different factors, such as new call blocking probability, handover call dropping probability, channel utilization, etc. Designing an optimal CAC scheme is still a challenging task due to having a number of considerable factors, such as new call blocking probability, handover call dropping probability, channel utilization, traffic rate, etc. Among existing CAC schemes such as, fixed guard band (FGB), fractional guard channel (FGC), limited fractional channel (LFC), and Uniform Fractional Channel (UFC), the LFC scheme is optimal considering the new call blocking and handover call dropping probability. However, this scheme does not consider channel utilization. In this paper, a CAC scheme, which is termed by a uniform fractional band (UFB) to overcome the limitations of existing schemes, is proposed. This scheme is oriented by priority and non-priority guard channels with a set of fractional channels instead of fractionizing the total channels like FGC and UFC schemes. These fractional channels in the UFB scheme accept new calls with a predefined uniform acceptance factor and assist the network in utilizing more channels. The mathematical models, operational benefits, and the limitations of existing CAC schemes are also discussed. Subsequently, we prepared a comparative study between the existing and proposed scheme in terms of the aforementioned QoS related factors. The numerical results we have obtained so far show that the proposed UFB scheme is an optimal CAC scheme in terms of QoS and resource utilization as compared to the existing schemes.

A Study on the Rhythm of Korean EFL Learners' English Pronunciation (한국인 영어학습자의 영어리듬구현 연구)

  • Chung, Hyun-Song
    • Phonetics and Speech Sciences
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    • v.1 no.2
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    • pp.141-149
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    • 2009
  • An emphasis on teaching suprasegmental features of English, specifically English rhythm, is essential in order to improve the 'intelligibility' of the pronunciation of Korean EFL learners among interlocutors who use English as a Lingua Franca(ELF). By redefining the ELF suggested by Jenkins (2000, 2002), this paper argues that Lingua Franca Core (LFC) must include suprasegmental features such as 'stress-based rhythm' and word stress. However, because 'isochrony' is difficult to measure in a foot, the rhythm unit must be expanded to an intonational phrase which has prominence in it and the rhythm of the unit can be measured by calculating the duration of each segment in context The rhythmic pattern of Korean learners of English and that of native speakers or other non-native English speakers can then be calculated and compared by using correlation coefficients of the segmental duration. In terms of sociolinguistic factors, improving the 'comprehensibility' and 'accentedness' of Korean EFL learners' pronunciation is also important in international communication, which calls for more emphasis on suprasegmental features.

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Introduction of Generator Unit Controller and Its Tuning for Automatic Generation Control in Korean Energy Management System (K-EMS)

  • Park, Min-Su;Chun, Yeong-Han
    • Journal of Electrical Engineering and Technology
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    • v.6 no.1
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    • pp.42-47
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    • 2011
  • Automatic generation control (AGC) is an important function for load frequency control, which is being implemented in Energy Management System (EMS). A key feature of AGC is to back up governors to enhance the performance of frequency control. The governor regulates system frequency in several to ten seconds, while the droop control concept results in steady-state control error. AGC is a supplementary tool for compensation of the steady-state error caused by the droop setting of the governors. As the AGC target is delivered to each generator as an open loop control target, the generator output is not guaranteed to follow the AGC target. In this paper, we introduce generating unit controller (GUC) control block, which has the purpose of enabling the generator output to track the AGC target while maintaining the governor performance. We also address the tuning methods of GUC for better performance of AGC in the Korea Energy Management System (K-EMS).

Design of Robust FPID Controller and Control Characteristics for Load Frequency Control in Power System (전력시스템의 부하주파수제어를 위한 강인한 FPID제어기의 설계와 제어특성)

  • Moon, Young-Moon;Kim, Hae-Jae;Ahn, In-Mo;Joo, Seok-Min
    • Proceedings of the KIEE Conference
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    • 1999.11a
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    • pp.28-30
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    • 1999
  • This paper proposes a robust FPID(Fuzzy Proportional Integral Derivative) controller for the LFC(load frequency control) of 2-area power system. The PID gain parameters of the proposed robust FPID controller are self-tuned by PSGM(Product Sum Gravity Method) which is very similiar to human's inference procedures. As the results of simulation, the proposed FPID controller against various load disturbances shows that it is superior to the conventional control techniques such as optimal, PID and fuzzy control in the response characteristics of frequency and tie line power flow.

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A study on load frequency control characteristics of power systems using IA-PID controller (IA-PID 제어기를 이용한 전력시스템의 부하주파수 제어 특성에 관한 연구)

  • Kim, C.H.;Lee, J.P.;Mun, M.K.;Chung, H.H.
    • Proceedings of the KIEE Conference
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    • 2001.05a
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    • pp.116-119
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    • 2001
  • In this paper. the robust PID controller using immune algorithm(IA) for load frequency control(LFC) is designed. In proposed method. objective function is represented as antigens. An affinity calculation is embedded within the algorithm for determining the promotion or suppression of antibody. Simulation results show that the proposed robust load frequency controller can achieve good performance even in the presence of generation rate constraints.

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Extended Integral based Governor Control for Power System Stabilization (확장된 PI 제어를 이용한 전력계통 안정도 향상에 관한 연구)

  • Kim, Hyun-Sung;Min, Kyoung-Il;Ryu, Heon-Su;Moon, Young-Hyun
    • Proceedings of the KIEE Conference
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    • 2002.11b
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    • pp.268-270
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    • 2002
  • 본 논문에서는 댐핑이 고려된 전력계통에서 동요시 안정도를 향상시킬 수 있는 확장된 PI제어를 이용한 조속기 제어기를 제안하였다. 전력계통에서의 동요는 대부분 고장기간 동안에 발전기에 저장된 과잉운동에너지에 의해 발생한다. 계통이 안정하도록 하기 위해서 과잉에너지를 효과적으로 다루려면 보통 직접법을 사용된다. 과잉에너지를 제어하기 위한 직접적인 방법으로는 LFC(Load Frequency Control)의 궤한이 활용된다. 확장된 PI제어 방식이 적용된 제어기는 지역내에서와 지역사이에서의 동요를 감쇄시키기 위한 조속기에 적용될 수 있다 또한 제안된 제어기는 조속기에 스팀밸브 제한 조건이나 발전율 제약조건(Generation Rate Constraint; GRC)과 같은 특이점이 존재할 때에도 우수한 성능을 보여주었다. 시뮬레이션은 두지역의 다기계통에서 부하를 변화시켜가며 실시하였다. 시뮬레이션 결과는 제안된 PI 제어기를 기존의 PI 제어기와 비교하여 매우 향상된 성능을 보여주었다.

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Cache Replacement Schemes for Data Driven Label Switching (데이터 기반 레이블 스위칭을 위한 캐쉬 대체 기법)

  • 김남기;진성기;박선영;윤현수
    • Proceedings of the Korean Information Science Society Conference
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    • 2000.04a
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    • pp.445-447
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    • 2000
  • 인터넷이 급속도로 발전되면서 트래픽이 폭발적으로 증가하여 현재 라우터에 많은 부담을 주고 있다. 반면 스위칭 기술은 라우팅보다 빠르게 데이터를 전송할 수 있다. 그 결과 라우터 병목 현상을 해결하고자 IP 라우팅에 스위칭 기술을 접목한 레이블 스위칭 네트웍이 출현하게 되었다. 레이블 스위칭 기술 중 데이터 기반 레이블 스위칭에서 매우 중요한 것은 캐쉬 테이블 관리이다. 캐쉬 테이블에는 흐름 분류를 위한 정보와 레이블 스위칭을 위한 정보를 저장하고 있는데 캐쉬테이블 크기는 라우터 자원에 의해 제약을 받으므로 캐쉬 대체 기법이 필요하게 된다. 따라서 효율적인 캐쉬 테이블 관리를 위해 인터넷 트래픽 특성을 고려한 캐쉬 대체 기법에 관한 연구가 필요하다. 본 논문에서는 인터넷 트래픽 특성을 고려해 기본적인 FIFO, LFC, LRU 기법을 실제 인터넷 트래픽을 사용해 성능 평가하고 새로운 가중치 우선순위 LRU 기법을 제안한다. 특히 가중치 우선순위 LRU 기법은 플로우 인앤아웃 현상이 없고 시간이 지나도 새로운 플로우를 적절히 생성해내는 일관성을 지니면서도 스위칭 비용을 줄이는 장점을 가지고 있다.

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