• Title/Summary/Keyword: TMAC

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A Multichannel TDMA MAC Protocol to Reduce End-to-End Delay in Wireless Mesh Networks

  • Trung, Tran Minh;Mo, Jeong-Hoon
    • ETRI Journal
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    • v.32 no.5
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    • pp.819-822
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    • 2010
  • Supporting QoS over multihop wireless mesh networks is difficult because end-to-end delay increases quickly with the increasing number of hops. This paper introduces a novel multichannel time-division multiple-access media access control (McTMAC) protocol that can help to efficiently reduce delay over multihop networks. Performance evaluation results demonstrate that McTMAC outperforms existing alternative protocols. The max-delay can be reduced by as much as 60% by using McTMAC.

Synthesis and Characterization of Very High Molecular Weight Nylon 4 and Nylon 4/6 Copolymers (매우 높은 분자량을 갖는 Nylon 4 및 Nylon 4/6 공중합체의 합성 및 그 특성 분석)

  • Kim, Nam Cheol;Kim, Ji-Heung;Nam, Sung Woo;Jeon, Boong Soo;Yoo, Young-Tai;Kim, Young Jun
    • Polymer(Korea)
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    • v.37 no.2
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    • pp.211-217
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    • 2013
  • Potassium tert-butoxide (t-BuOK) with $CO_2$ or benzoyl chloride (BzC) as a polymerization initiator system was used with crown ether or TMAC as catalyst to synthesize very high molecular weight nylon 4 homo- and copolymers by anionic ring opening polymerization. Effect of different amounts of catalyst, crown ether and TMAC on the polymerization was studied in terms of intrinsic viscosity, yield and thermal properties. By adding crown ether or TMAC, polymers with very higher intrinsic viscosity values were obtained in a high yield. It was possible to synthesize nylon 4 homopolymer with such a high intrinsic viscosity value of 6.36 dL/g. Crown ether was found to be more efficient in terms of intrinsic viscosity and polymer yields than TMAC. Thermal analysis confirmed that molecular weight effect on the thermal properties of both nylon 4 and nylon 4 copolymer was marginal.

A Security Analysis of PMAC and TMAC variant (PMAC과 TMAC 변이 알고리즘에 대한 안전성 고찰)

  • 이창훈;김종성;이상진
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.14 no.4
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    • pp.91-96
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    • 2004
  • In this paper, we introduce two forgery attacks on the PMAC. If it has no truncation then the attack requires about $2^{n}$ 2+1/ chosen texts, otherwise, the attack requires about $2^{n}$ 2+1/ chosen texts and $2^{n-}$$\tau$ MAC verifications where $\tau$ is the size of the MAC. We also give a forgery attack on the TMAC variant which requires about $2^{n}$ 2+1/ texts.

Effect of rearing system (free-range vs cage) on gut and muscle histomorphology and microbial loads of Italian White breed rabbits

  • Caterina Losacco;Antonella Tinelli;Angela Dambrosio;Nicoletta C. Quaglia;Letizia Passantino;Michele Schiavitto;Giuseppe Passantino;Vito Laudadio;Nicola Zizzo;Vincenzo Tufarelli
    • Animal Bioscience
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    • v.37 no.1
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    • pp.151-160
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    • 2024
  • Objective: The growing consumers' interest on animal welfare has raised the request of products obtained by alternative rearing systems. The present study was conducted to assess the influence of housing system on gut and muscle morphology and on microbial load in rabbits reared under free-range (FR) and cage system (CS). Methods: A total of forty weaned (35 days of age) male Italian White breed rabbits were allotted according to the rearing system, and at 91 days of age were randomly selected and slaughtered for the morphological evaluation of tissue from duodenum and longissimus lumborum. Morphometric analysis of the villus height, villus width, crypt depth, villus height/crypt depth ratio, and villus surface was performed. The microbial loads on hind muscle was determined by total mesophilic aerobic count (TMAC), Escherichia coli and Enterobacteriaceae; whereas, total anaerobic bacteria count (TABC) and TMAC, E. coli and Enterobacteriaceae was determined on caecal content. Results: Rearing system did not interfere with the duodenum and muscle histomorphology in both rabbit groups. Similarly, microbial load of caecal content showed no significant differences on the TABC and TMAC. Conversely, significant difference was found for E. coli strains in caecal content, with the lower counts in FR compared to CS rabbits (p<0.01). Microbiological assay of muscle revealed significant lower TMAC in FR vs CS rabbits (p< 0.05). All rabbit meat samples were negative for E. Coli and Enterobacteriaceae. Conclusion: Free-range could be considered a possible alternative and sustainable rearing system in rabbits to preserve gut environment and muscle quality.

Vulnerability Analysis in T-MAC Environment (T-MAC환경에서 취약성 분석)

  • Hong, Jin-Keun;Han, Kun-Hee
    • Proceedings of the KAIS Fall Conference
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    • 2010.05a
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    • pp.166-168
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    • 2010
  • 본 논문에서는 TMAC 환경에서 취약성 분석하였다. T-MAC의 보안 특성은 S-MAC 통신 프로토콜이 갖는 보안 취약성과 동일한 형태이다. T-MAC 통신은 TA가 도입된 것을 제외하면, S-MAC에서 강조하고 있는 동일한 보안 인증방안이 필요함을 확인할 수 있다.

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