• Title/Summary/Keyword: Distributed Control Protocol

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Mutual Authentication Method between Wireless Mesh Enabled MSAPs in the Next-generation TICN (차세대 전술정보통신체계에서의 무선 메쉬 MSAP 노드 간 상호 인증 기법)

  • Son, Yu-Jin;Bae, Byoung-Gu;Shon, Tae-Shik;Ko, Young-Bae;Lim, Kwang-Jae;Yun, Mi-Young
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.37 no.5B
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    • pp.385-394
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    • 2012
  • The tactical mobile communication network, which comprises a part of the next-generation Tactical Information and Communication Network (TICN), provides means of communication and control for Tactical Multi-Functional Terminals (TMFT) belonging to a Mobile Subscriber Access Point (MSAP). The next-generation of MSAP is capable of constructing a backbone network via LCTR and HCTR directional antennas. At the same time, WMN modules are used to create and manage a wireless mesh backbone. When directional antennas are used in mobile environments, seamless services cannot be efficiently supported as the movement of the node prevents the angle of the antenna to constantly match. Therefore, data communication through the wireless mesh networks is required to provide direct communication between mobile MSAPs. Accordingly, mutual authentication and data encryption mechanisms are required to provide reliable data transmission in this environment. To provide efficient mutual authentication between MSAP devices, the process of verifying a certificate of the other MSAP device through its own authentication server is required. This paper proposes mutual authentication mechanisms where the MSAP requiring authentication and the MSAP that permits it initiates low-cost and efficient authentication in a distributed way. More specifically, we propose a method of applying EAP-ELS (Extensible Authentication Protocol-Transport Layer Security) in the next-generation TICN.

Changes in Glucosinolate Component Content in Urine After Ingestion of Fresh and Cooked Broccoli (신선한 브로콜리와 조리된 브로콜리 섭취 후 소변으로 배설되는 Glucosinolates 대사물질의 함량 변화)

  • Hwang, Eun-Sun
    • Korean journal of food and cookery science
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    • v.26 no.6
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    • pp.804-810
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    • 2010
  • Sulforphane (SF) is a family of biologically active compound that is distributed widely in broccoli. Although studies in rodents have shown that these compounds are effective and versatile inhibitors of tumorigenesis, the role of dietary SF in protection against human cancers remains to be established. The objective of this study was to explore the quantitative relationship between the dietary intake of cruciferous vegetables and urinary excretion of SF. The effects of dietary broccoli on the body's ability to detoxify were studied in six male subjects between the ages of 22~30 years. Study included administering a glucosinolate-free diet for 8 days (control period). The broccoli diet was further subdivided into two periods; 250 g broccoli was fed per day during the first three days and 500 g broccoli was fed per day during the latter three days. After an 8-day washout period, a second experiment was conducted. The same protocol was used with the exception that uncooked broccoli was consumed. Urinary SF mercapturate was measured to determine the bioavailability of broccoli. The linear trend for mercapturate excretion was dose-dependent, resulting in 3.8- and 1.9-fold increase by the third and six days, respectively, compared to the control. Lower amount of SF-NAC conjugate was detected in cooked broccoli compared to fresh broccoli suggesting cooking may have caused a significant loss in glucosinolates in cruciferous vegetables. Therefore, SF can be used as a biomarker for intake of cruciferous vegetables.

A DCF Throughput Analysis of the Ideal and Fading Channel in the Wireless LAN (무선 LAN에서 이상 및 페이딩 채널 환경의 DCF 처리율 비교 분석)

  • Lee, Yong-Sik;Lee, Ha-Cheol;Lee, Byung-Ho
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.19 no.7
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    • pp.741-753
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    • 2008
  • This paper explores the throughput performance of CSMA/CA-based DCF protocol over both ideal channels and fading channels with payload size at the MAC layer in the 802.11a wireless LAN. In the ideal channel, there are no errors and at the transmission cycle there is one and only one active station which always has a packet to send and other stations can only accept packets and provide acknowledgements. In the fading channel, bit errors appear in the channel randomly and the number of stations is assumed to be fixed. And each station always has packets for transmission. In other words, we operate in saturation conditions. Up to now conventional research work about DCF throughput analysis of IEEE 802.11 a wireless LAN has been done over the ideal channel, but this paper is done over the Rayleigh/Ricean fading channel. So, the ratio of received average energy per bit-to-noise power spectral density $E_b/N_o$ is set to 25 dB and the ratio of direct-to-diffuse signal power in each sub-channel $\xi$ is set to 6 for combined Rayleigh/Ricean fading channel. In conclusion, it is shown that the saturation throughput is always less than the maximum throughput at all the payload size and the higher the transmission rate be, the higher the decreasing rate of saturation throughput compared to the maximum throughput be.

A Study on Activation of Oriental Medicine in Public Health Sector : The role of Oriental Public Health Physicians (한방 공공의료의 활성화에 관한 연구 - 공중보건 한의사의 활동을 중심으로 -)

  • Yi Sang-Gu;Moon Ok-Ryun;Piao Song-Lin;Lee Shin-Jae;Yoon Tae-Ho;Jeong Baek-Geun;Wen Yong
    • Journal of Society of Preventive Korean Medicine
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    • v.4 no.1
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    • pp.1-16
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    • 2000
  • From 1998, Oriental Medical Physicians(OMP) is distributed in Public Health Sector. but long term plan for Oriental Medicine in Public Health is not existed. So, this study is designed for the activation of OMP Subjects in this study were comprised 3 groups of oriental medicine related persons, the group of which are Students of 11 Oriental Medical Schools, Oriental Medical Physicians in Public Health Sector, Specialist Croup of Oriental medicine Policy(total 1,458 persons). Data were collected from July 1st to November 30, 1999. Direct interview with key persons, systematic interview by using of interview protocol, e-mail and facsimile have been conducted. The results of survey were coded by Excel 5.0, and analysed with SAS 6.12 statistical package. Inter-group difference determined by T-test, and descriptive statistics have been examined. Major findings can be epitomized as follows. 1) OMP disposition to multifarious organizations and institutes such as Public Health Centers, Public Health Sub-centers, Public Hospitals, Private Hospitals in Remote-Vulnerable Area, Community Social Welfare Centers, Institutes for Heath Policy Research, etc, will promise an effective use of Oriental Medical Physician. 2) Average number of patients treated by OMP was 22.8, average budget for oriental medical department, in which OMP were affiliated, was 39.6 million Won per year. Direct cost per every patient visit was 7,210.9 Won, which is considered expensive for public health service. Therefore, development and transformation for Oriental Medical Service in Public Health Sector is desirable in economic and political aspects. 3) It is recommended that ${\ulcorner}Advisory\;Committee{\lrcorner},{\ulcorner}Planning\;Commission\;for\; Public\;Health\;in\;Oriental\;Medicine{\lrcorner}$ should be established for the activation and for the support of Oriental Medical Physician in Public Health Sector, 4) Most effective programmes for oriental public health doctor are health service programmes for the elderly, Home health visit, chronic degenerative disease control services(p<0.001). 5) Standard guideline for facilities and equipments of Oriental Medicine Department in Public Health Center is needed for optimal supply of resources and activation of public health activity.

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Fast Join Mechanism that considers the switching of the tree in Overlay Multicast (오버레이 멀티캐스팅에서 트리의 스위칭을 고려한 빠른 멤버 가입 방안에 관한 연구)

  • Cho, Sung-Yean;Rho, Kyung-Taeg;Park, Myong-Soon
    • The KIPS Transactions:PartC
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    • v.10C no.5
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    • pp.625-634
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    • 2003
  • More than a decade after its initial proposal, deployment of IP Multicast has been limited due to the problem of traffic control in multicast routing, multicast address allocation in global internet, reliable multicast transport techniques etc. Lately, according to increase of multicast application service such as internet broadcast, real time security information service etc., overlay multicast is developed as a new internet multicast technology. In this paper, we describe an overlay multicast protocol and propose fast join mechanism that considers switching of the tree. To find a potential parent, an existing search algorithm descends the tree from the root by one level at a time, and it causes long joining latency. Also, it is try to select the nearest node as a potential parent. However, it can't select the nearest node by the degree limit of the node. As a result, the generated tree has low efficiency. To reduce long joining latency and improve the efficiency of the tree, we propose searching two levels of the tree at a time. This method forwards joining request message to own children node. So, at ordinary times, there is no overhead to keep the tree. But the joining request came, the increasing number of searching messages will reduce a long joining latency. Also searching more nodes will be helpful to construct more efficient trees. In order to evaluate the performance of our fast join mechanism, we measure the metrics such as the search latency and the number of searched node and the number of switching by the number of members and degree limit. The simulation results show that the performance of our mechanism is superior to that of the existing mechanism.