• Title/Summary/Keyword: 11E

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Analysis on the Performance Unfairness Problem of the Heterogeneous Environment with IEEE 802.11b and 802.11e (IEEE 802.11e와 802.11b 표준이 혼재하는 이종환경에서의 불공평 문제 성능 분석)

  • Lim Yujin
    • The KIPS Transactions:PartC
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    • v.12C no.2 s.98
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    • pp.217-222
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    • 2005
  • The IEEE 802.11 based wireless local area networks are candidates to lead the broadband connectivity in the home and office scenarios. Recently IEEE proposed the 802.11e as a new standard to provide appropriate Quality of Services to a plethora of emerging real-time multimedia and high demanding applications such as high definition movie and audio distribution, video-conference and voice over IP. This paper studies the IEEE 802.11e/IEEE 802.11b interactions focusing on potential unfairness problems that might appear in networks with heterogeneous wireless LAN technologies as well as in the IEEE 802.11e deployment phase.

Studies on Esterase of Pieris rapae L. II. Biochemical Properties and Immunological Studies (배추흰나비(Pieris rapae L.)의 esterase에 관한 연구 II. 생화학적 특성 및 면역학적 연구)

  • 박철호;김학열;여성문
    • The Korean Journal of Zoology
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    • v.33 no.3
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    • pp.337-345
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    • 1990
  • The properties of three esterases (E2, E6 and E11) which were previously purified from Pieris rapae L. were determined and physiological role of E6 was inferred using immunological methods. Based on inhibitor study, all of the purified esterases were found to be carboxylesterases (EC 3.1.1.1). The Km values for E2, E6 and E11 were determined to be 6.89 X 10-$^4$M. 3.19 $\times$ l0-$^4$M and 3.69 X 10-$^4$M, respectively. The molecular weights of E2, E6 and E11 were estimated to be 42 KD, 81 KD and 174 KD, respectively. The isoelectric points of E2, E6 and E11 were estimated to be pH 5.54, pH 5.89 and pH 6.50, respectively. The concentration of E6 during development was highest at the late 5th instar larval stage and that according to organs at the same stage was highest in midgut. These results suggest that E6 might be a hydrolase involved in the digestion of dietary lipids.

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Performance Evaluation of EDCA Channel Access Scheme at IEEE 802.11e WLANs (IEEE 802.11e 무선 LAN에서 EDCA 기법의 성능 분석)

  • Jeon, Hyeong-Ik;Jang, Jae-Shin
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • v.9 no.1
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    • pp.528-532
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    • 2005
  • As the current IEEE 802.11 wireless LAN standard provides the unified channel access procedure for each traffic service without considering its own traffic characteristics, it is difficult to get its differentiated service qualities at IEEE 802.11 wireless LAN system. To solve this limit, IEEE 802.11e standard that can provide differentiated service to each traffic is under preparation. In this study, we implemented IEEE 802.11e EDCA channel access scheme with NS-2 simulator, and showed its numerical results in various system environments with using average delay and throughput as performance measures.

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Isomer specificity of conjugated linoleic acid (CLA): 9E,11E-CLA

  • Lee, Yun-Kyoung
    • Nutrition Research and Practice
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    • v.2 no.4
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    • pp.326-330
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    • 2008
  • Conjugated linoleic acids (CLA) were identified in 1980's, since then it has been intensively studied due to its various beneficial health effects such as anti-inflammatory, anti-atherogenic, anti-carcinogenic and anti-diabetic/obesity effects. Isomer specificity of a number of CLA isomers, especially predominant isomer 9Z,11E- and 10E,12Z-CLA, is now recognized. However, the less prevalent CLA isomers have not been well characterized. Recently, studies have reported the distinctively different effects of 9E, 11E-CLA in colon cancer cells, endothelial cells, and macrophage cells compared to the rest of CLA isomers. In this review, various effects of CLAs, especially anti-inflammatory and anti-atherogenic effects, will be discussed with focusing on the isomer-specific effects and potential mechanism of action of CLA. At last, recent studies about 9E,11E-CLA in in vitro and animal models will be discussed.

Access delay and packet delay of EDCA in IEEE 802.11e wireless network (IEEE 802.11e EDCA 무선랜의 매체 접속 지연 시간 및 정상 상태에서의 패킷 지연 분석)

  • Lee, Yu-Tae;Jang, Jong-Min;Lee, Key-Sang;Kim, Dong-Il;Kim, Chang-Kyu
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.12 no.8
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    • pp.1420-1426
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    • 2008
  • This paper derives medium access delay of each AC(Access Category) in a stationary station using inter-departure time of IEEE 802.11e WLAN(Wireless LAN). Inter-departure time of IEEE 802.11e WLAN is obtained using saturation throughput of IEEE 802.11e WLAN which was the topic of our prior work. By using a simple queueing model, we evaluate mean queue length and mean delay for each AC on stationary condition. We calculate performance of each AC using this simple model and validate results using simulation.

Experimental Effectiveness Analysis of IEEE 802.11e by using Wireless Mesh Network Testbed (무선메쉬네트워크 테스트베드를 통한 IEEE 802.11e의 실험적 성능분석)

  • Yoo, Jae-Yong;Kim, Jong-Won
    • Proceedings of the Korean Information Science Society Conference
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    • 2007.10d
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    • pp.585-588
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    • 2007
  • WMNs(Wireless Mesh Networks)은 기존 유 무선망 구축 시 발생하는 고가의 비용 및 이동성 제약 등의 단점을 극복하기 위해 제안된 네트워크 구조로써 네트워크 구축비용에 비해 광범위한 인터넷 접근영역을 제공하는 장점을 가진다. 특히, IEEE 802.11e를 MAC 계층으로 사용하는 WMN은 기존 IEEE802.11에서 보다 강화된 QoS(Quality of Service)기능을 가지므로, 안정적 멀티미디어 관련 응용 계층을 지원하는 WMN 구축을 위해 주목받고 있는 기술 중 하나이다. 본 논문은 광주과학기술원에 설치된 MIMC(Multi-Interface Multi-Channel) WMN 테스트베드를 QoS 기능 지원을 위해 IEEE 802.11e 기반으로 확장한다. 특히, 확장에 필요한 소프트웨어 요소 및 하드웨어 요소에 대해 논한다. 또한, 확장된 IEEE 802.11e WMN 테스트베드를 사용하여 현재 주목받고 있는 IEEE 802.11e기반 WMN의 기본 쓰루풋 성능, 쓰루풋 차별화 성능등을 실험적으로 분석한다.

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QoS Support to Design for IEEE802.11e based in Wireless Mesh Networks (IEEE802.11e를 기반으로 한 Wireless Mesh Networks에서 QoS 향상 방법 설계)

  • Seo, Hyung-Yoon;Kim, Dong-Hyun;Kim, Jong-Deok
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2010.05a
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    • pp.702-704
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    • 2010
  • Wireless LAN(Local Area Network) environment to support QoS in IEEE802.11 Working Group has standardized on the IEEE 802.11e. IEEE 802.11e EDCA channel access of the high priority traffic as by raising the probability of a chance to support QoS. This is a high priority traffic than low priority traffic, channel access is not necessarily the first. Therefore, as all traffic channels, if you have the same routing path, lower priority traffic on the performance of high priority traffic, sustainable impact. As a result, EDCA, such as voice or video to guarantee QoS for multimedia applications, follow the crowd. In this paper, to solve these problems by using Multi-Interface Multi-Path Routing Algorithm is proposed. Interface for each use in IEEE 802.11e EDCA Access Category much differently by each of the Routing Path for high priority traffic and guarantee QoS.

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Induction of Rice Allergen-Specific IgE Synthesis by KU8l2 Cells (KU812세포에 의한 쌀 알레르겐 특이적 IgE항체 합성의 유도)

  • Shim, Sun-Yup;Katakura, Yoshinori;Shirahata, Sanetaka
    • Journal of Life Science
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    • v.17 no.11
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    • pp.1492-1496
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    • 2007
  • In vitro IgE class switching could be induced through co-culture of CD40L-expressing KU812 cells and CD40-expressing B cells in the presence of IL-4 or IL-13. It has been generated several B cell lines, which produce rice allergen (RA)-specific IgM antibody by in witγo immunization (IVI) using peripheral blood lymphocyte (PBL). In this study, induction of RA-specific IgE antibody by KU812 cells was attempted. Before co-culture, we determined the CD40 expression in RA-specific B cell lines, RA9G11 and the CD40 ligand (CD40L) expression in activated KU812 cells by treatments with phorbol myristate acetate (PMA) and ionomycin for 6 hrs. Flow cytometric analysis shown that RA9G11 and activated KU812 cells expressed high level of CD40 and CD40L, respectively. RA9G11 cells were cultured with activated KU812 cells for 12 days in the presence of IL-4 for IgE class switching. Mature $C{\varepsilon}$ mRNA level and RA-specific IgE spot forming cells (SFC) were observed in all culture condition, and especially, high level of RA-specific IgE synthesis was determined the same ratio of RA9G11 and activated KU812 cells in the presence of 50U IL-4. Therefore, induction of RA-specific IgE synthesis by activated KU812 cells can be contributed in the application for allergic therapy and prevention.

Adaptive EDCF for IEEE802.11e MAC Protocol (IEEE 802.11e MAC의 성능향상을 위한 적응형 EDCF)

  • Kim Kunsu;Kim Beomjoon;Park Jungshin;Lee Jaiyong
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.30 no.1A
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    • pp.62-69
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    • 2005
  • Efforts for standardization of medium access control (MAC) protocol in IEEE802.11e have been made to support quality of service (QoS) in IEEE802.11e MAC protocol. Enhanced disoibuted coordination function (EDCF) of 802.11e MAC protocol is modified to support QoS for packets that have differentiated priority. However, EDCF still has the problem of throughput optimization and priority support. Therefore, we have proposed a scheme called adaptive EDCF for both supporting priority of packets and throughput optimization. We have derived the relation between the number of nodes and contention window size for throughput optimization. Based on the analytic results, we have evaluated the performance of the proposed scheme using OPNET simulations. The simulation results show that using the proposed scheme can improve the overall throughput regardless of the number of nodes and the decrement of the throughput with increasing the number of nodes can be alleviated. Additionally, we have shown that the adaptive EDCF can support priority of packets more effectively than existing EDCF.