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3TP: An application-layer protocol for streaming 3-D models

IEEE TRANSACTIONS ON MULTIMEDIA 2005年第6期7卷 1149-1156页

作者： Alregib, G Altunbasak, Y Georgia Inst Technol Sch Elect & Comp Engn Savannah GA 31407 USA Georgia Inst Technol Sch Elect & Comp Engn Atlanta GA 30332 USA

This paper addresses the problem of streaming progressively compressed three-dimensional (3-D) models over lossy networks. Out of all encoded packets that can be transmitted, we intelligently choose a subset of packets to be transmitted using transport control protocol in order to meet a distortion constraint, while transmitting the remaining packets using user datagram protocol to minimize the end-to-end delay. We call this new application-layer protocol 3-D models transport protocol. We show the effectiveness of this protocol both experimentally and theoretically. We compare the performance of the proposed protocol with systems that do not optimize transmission according to the content of the encoded bitstream. When the maximum distortion is 30, measured using the Hausdorff distance, we achieve savings in delay time ranging from 39% to 68% for packet-loss rates between 1% and 19%.

关键词： encoding media streaming transport protocols 3D model streaming Hausdorff distance application-layer protocol encoded bitstream end-to-end delay transport control protocol user datagram protocol Packet media streaming application layer user datagram protocol/internet protocol Transmission control protocol End-to-end delay coding transport protocols

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TCP-friendly transmission of voice over IP

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EUROPEAN TRANSACTIONS ON TELECOMMUNICATIONS 2003年第3期14卷 193-203页

作者： Beritelli, F Ruggeri, G Schembra, G Univ Catania Dipartimento Ingn Informat & Telecomun I-95125 Catania Italy

In the last few years an increasing amount of attention has been paid to technologies for the transmission of voice over IP (VoIP). At present, the UDP transport protocol is used to provide this service. However, when the same bottleneck link is shared with TCP flows, and in the presence of a high network load and congestion, UDP sources capture most of the bandwidth, strongly penalizing TCP sources. To solve this problem some congestion control should be introduced for UDP traffic as well, in such a way that this traffic becomes TCP-friendly. In this perspective, several TCP-friendly algorithms have been proposed in the literature. Among them, the most promising candidates for the immediate future are RAP and TFRC. However, although these algorithms were introduced to support real-time applications on the internet, up to now the only target in optimizing them has been that of achieving fairness with TCP flows in the network. No attention has been paid to the applications using them, and in particular, to the quality of service (QoS) perceived by their users. The target of this paper is to analyze the problem of transmitting voice over IP when voice sources use one of these TCP-friendly algorithms. With this aim, a VoIP system architecture is introduced and the characteristics of each its elements are discussed. To optimize the system, a multirate voice encoder is used so as to be feasible to work over a TCP layer, and a modification of both RAP and TFRC is proposed. Finally, in order to analyze the performance of the proposed system architecture and to compare the modified RAP and TFRC with the original algorithms, the sources have been modeled with an arrival process modulated by a Markov chain, and the model has been used to generate traffic in a simulation study performed with the ns-2 network simulator. Copyright (C) 2003 AEI.

关键词： transmission REMEDIAL ACTION PROGRAM Building systems EIS IMPLEMENTATION PLANS Voice over internet protocol tactical command post Uridine Diphosphate Traffic user datagram protocol/internet protocol algorithms Voice network simulator TFRC gene Tritolyl Phosphates Markov chain

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Towards the synthesis of glycosylated dihydrochalcone natural products using glycosyltransferase-catalysed cascade reactions

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GREEN CHEMISTRY 2014年第9期16卷 4417-4425页

作者： Gutmann, Alexander Bungaruang, Linda Weber, Hansjoerg Leypold, Mario Breinbauer, Rolf Nidetzky, Bernd Graz Univ Technol NAWI Graz Inst Biotechnol & Biochem Engn A-8010 Graz Austria Graz Univ Technol NAWI Graz Inst Organ Chem A-8010 Graz Austria Austrian Ctr Ind Biotechnol A-8010 Graz Austria

Regioselective O-beta-D-glucosylation of flavonoid core structures is used in plants to create diverse natural products. Their prospective application as functional food and pharmaceutical ingredients makes flavonoid glucosides interesting targets for chemical synthesis, but selective instalment of a glucosyl group requires elaborate synthetic procedures. We report glycosyltransferase-catalysed cascade reactions for single-step highly efficient O-beta-D-glucosylation of two major dihydrochalcones (phloretin, davidigenin) and demonstrate their use for the preparation of phiorizin (phloretin 2'-O-beta-D-glucoside) and two first-time synthesised natural products, davidioside and confusoside, obtained through selective 2'- and 4'-O-beta-D-glucosylation of the dihydroxyphenyl moiety in davidigenin, respectively. Parallel biocatalytic cascades were established by coupling uridine 5'-diphosphate (UDP)-glucose dependent synthetic glucosylations catalysed by herein identified dedicated O-glycosyltransferases (OGTs) to UDP dependent conversion of sucrose by sucrose synthase (SuSy;from soybean). The SuSy reaction served not only to regenerate the UDP-glucose donor substrate for OGT (up to 9 times), but also to overcome thermodynamic restrictions on dihydrochalcone beta-D-glucoside formation (up to 20% conversion and yield enhancement). Using conditions optimised for overall coupled enzyme activity, target 2'-O- or 4'-O-beta-D-glucoside was obtained in >= 88% yield from reactions consisting of 5 mM dihydrochalcone acceptor, 100 mM sucrose, and 0.5 mM UDP. Davidioside and confusoside were isolated and their proposed chemical structures confirmed by NMR. OGT-SuSy cascade transformations present a green chemistry approach for efficient glucosylation in natural products synthesis.

关键词： synthesis dihydrochalcone user datagram protocol/internet protocol cascades Phloretin Natural products core structure Functional foods OGT gene Saccharose chemical synthesis Uridine Diphosphate

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ENZYMATIC-SYNTHESIS OF POLYURIDYLIC ACID CONTAINING MODIFIED BASES

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NUCLEIC ACIDS RESEARCH 1980年第14期8卷 3175-3191页

作者： HO, YK ARADI, J BARDOS, TJ SUNY BUFFALO DEPT BIOCHEM PHARMACOLBUFFALONY 14214

5-Mercaptouridine-5′-diphosphate (hs5UDP) has been synthesized and investigated as a substrate of the polynucleotide phosphorylase ofMicrococcusluteus. While hs5UDP is not utilized alone, It can be copolymerized with UDP; however, unusually for this enzyme, the ratio of 5-mercaptouridylatevs. uridylate residues in the polynucleotlde product (MPU) is always lower than the ratio of hs5UDPvs. UDP in the substrate mixture. Furthermore, hs5UDP decreases the rate of the enzymic polymerization reaction. The MPU productforms two-stranded and three-stranded complexes with poly(A). The circular dichroic spectra of these complexes are similar to those formed between poly(U) and poly(A), but their melting profiles indicate somewhat lower stability. The physicochemical and biochemical properties of the enzymic product are qualitatively similar to those of MPU prepared by chemical modification; both are potent inhibitors of a DNA-dependent RNA polyrmeras

关键词： Microprocessor chips Uridine Monophosphate Base materials Enzymatic synthesis Alkali Polyribonucleotide Nucleotidyltransferase Uridine Diphosphate chemical modification polyadenylic acid polyuridylic acid complexes user datagram protocol/internet protocol Bases Substrates

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REGULATION OF C-4 PHOTOSYNTHESIS - INACTIVATION OF PYRUVATE, PI DIKINASE IN LEAF AND CHLOROPLAST EXTRACTS IN RELATION TO DARK-LIGHT REGULATION INVIVO

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PLANT AND CELL PHYSIOLOGY 1981年第1期22卷 115-126页

作者： SUGIYAMA, T HATCH, MD SHIZUOKA UNIV SCH AGR DEPT AGR CHEM OYA SHIZUOKA 422 JAPAN CSIRO DIV PLANT IND CANBERRA ACT 2601 AUSTRALIA

Active pyruvate Pi dikinase in leaf or chloroplast [from Zea mays cv. Dekalb 805A] extracts isolated from illuminated leaves was inactivated by incubating with ADP. With chloroplast extracts neither ATP nor AMP alone was effective. Half the maximum rate of inactivation was observed with about 55 .mu.M ADP. Apparently, ADP-mediated inactivation had a co-requirement for low concentrations of ATP [Buchanan];adding hexokinase and glucose prevented inactivation by ADP [Feldhaus et al.] and when GDP and UDP were added in place of ADP they mediated rapid inactivation only when ATP was also provided;GTP was not effective. ATP was apparently optimally effective at .apprx. 1 .mu.M or less. The rate of inactivation was approximately proportional to the square of extract concentration, suggesting dependency on a factor in the extracts in addition to active enzyme. The involvement of one or more heat-labile protein factors was confirmed by trypsin treatment of extracts. Pyruvate Pi dikinase inactivated by treatment with ADP was reactivated by incubating with Pi, a property common to the inactive enzyme extracted from darkened leaves. Thiol/disulfide interconversion was apparently not critical in the regulation of pyruvate Pi dikinase.

关键词： In vivo Standing Orders Extracts Uridine Diphosphate Adenosine Diphosphate Regulation (biology) pyruvates Regulation Guanosine 5'-(trihydrogen diphosphate) foliage Inactivation user datagram protocol/internet protocol Automatic data processing Adenosine Triphosphate chloroplasts

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UDP GALACTOSE-4-EPIMERASE DEFICIENCY IN A 5.5-YEAR-OLD GIRL WITH UNILATERAL CATARACT

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JOURNAL OF INHERITED METABOLIC DISEASE 1993年第5期16卷 903-904页

作者： SCHULPIS, KH PAPACONSTANTINOU, ED KOIDOU, A MICHELAKAKIS, H TZAMOURANIS, J PATSOURAS, A SHIN, Y UNIV MUNICH DR VONHAUNERSCHEN KINDERSPITALW-8000 MUNICHGERMANY

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Reliable Aeronautical Services protocol: Motivation, Design, and Performance

Reliable Aeronautical Services Protocol: Motivation, Design,...

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IEEE Global Communications Conference (GLOBECOM)

作者： Muhammad, Muhammad de Cola, Tomaso Kissling, Christian Berioli, Matteo Deutsch Zentrum Luft & Raumfahrt DLR Inst Commun & Nav D-82234 Wessling Oberpfaffenhofe Germany

ISBN: (纸本)9781479913534

The most widely used transport protocols (i.e, TCP and UDP) are not suitable for aeronautical services because of the reliability and strict transfer delay requirements that cannot be met by TCP and UDP in such environment. In this respect, the paper proposes a novel message-oriented transport protocol Reliable Aeronautical Services protocol (RASP) enabling reliable aeronautical services. Simulation campaigns carried out in ns-2 show the superiority of RASP with respect to TCP in terms of end-to-end message transfer delay and number of performed retransmissions.

关键词： Tritolyl Phosphates tactical command post transport protocols Rasps user datagram protocol/internet protocol Uridine Diphosphate Legal Services protocols message passing

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Performance evaluation of OpenFlow controllers for network virtualization 15

Performance evaluation of OpenFlow controllers for network v...

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15th IEEE International Conference on High Performance Switching and Routing (HPSR)

作者： Turull, Daniel Hidell, Markus Sjodin, Peter KTH Royal Inst Technol Sch ICT Kista Sweden

ISBN: (纸本)9781479916337

This paper investigates OpenFlow performance, focusing on how the delay between switch and OpenFlow controller can impact the performance of a network. We use open-source controllers that support network virtualization to evaluate how such delay impacts ICMP, TCP and UDP traffic. We compare the controllers' flow set-up strategies and we conduct several experiments to compare their TCP and UDP performance. In addition, we introduce a new metric to measure UDP packet losses at the beginning of the flow. The results of the measurements indicate that there are large differences in performance between controllers, and that performance depends on switch-controller delay and flow set-up strategy.

关键词： Delays Loss measurement Ports (Computers) Switches Virtualization Virtualization loss measurement Switches Controllers delay Performance Evaluation user datagram protocol/internet protocol Uridine Diphosphate Tritolyl Phosphates tactical command post open source measurement result

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End-to-end Service Assurance in IoT MQTT-SN 12

End-to-end Service Assurance in IoT MQTT-SN

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2015 12th Annual IEEE Consumer Communications and Networking Conference (CCNC)

作者： Govindan, Kannan Azad, Amar Prakash Samsung Adv Inst Technol Samsung R&D Inst Bangalore 560037 Karnataka India

ISBN: (纸本)9781479963904

MQTT-SN offers energy efficient data transportation under unreliable wireless environment with limited energy/bandwidth. However, MQTT-SN faces a new set of challenges for service guarantees when operated for a reliable or time-critical applications. The impact of various network parameters on the MQTT-SN service assurance requires an end-to-end system study, which are unexplored yet. In this paper we analyze in detail about the end-to-end service assurance parameters such as content delivery delay and probability of content delivery for a MQTT-SN to be used in health care internet of Things (IoT). To model the end-to-end delay, various entities of the MQTT-SN including handshake messages in MQTT-SN Pub/sub architecture over TCP, over UDP and then the queuing delay involved in server have been considered. We model the MOTT content and request server as a round-robin queue scheduler and also model a TOPIC ID based matching station that delivers the content on requested TOPIC ID. With this model we derive the end-to-end content delivery probability and content delivery delay estimate as functions of MQTT-SN system parameters such as content arrival rate, request arrival rate, possession time of content in server, possession time of request in server, number of content arrivals and number of requests arrivals. Both these service assurance parameters will give more insight into the number of content/request arrivals that can be supported for a given service assurance requirement. In addition these service assurance parameters will be of help to design the system more effectively. We carry out a detailed ns2 based simulation to show impacts of various system parameters on the network performances for various QoS services designed for MQTT-SN system.

关键词： Content distribution Servers system parameter end-to-end network parameters queueing delay arrivals user datagram protocol/internet protocol Uridine Diphosphate arrival rate

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Hardware Architecture of an internet protocol Version 6 Processor 27

Hardware Architecture of an Internet Protocol Version 6 Proc...

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27th IEEE International System-on-Chip Conference (IEEE SOCC)

作者： Traskov, Boris Langenbach, Ulrich Hofmann, Klaus Gregorius, Peter Tech Univ Darmstadt Integrated Elect Syst Lab Darmstadt Germany Heinrich Hertz Inst Nachrichtentech Berlin GmbH Fraunhofer Inst Telecommun Berlin Germany

ISBN: (纸本)9781479933785

This paper presents the architecture of an internet protocol Version 6 processor for FPGA-based data processing and acquisition applications. Design choices and limitations are discussed together with a thorough simulation and verification methodology. The processor is demonstrated to frame and parse UDP over IPv6 traffic at 1Gb/s line-speed on a Virtex 5 FPGA, outperforming a reference soft-processor solution for UDP over IPv4. RTL-simulations show that 10Gb/s operation is attainable with the same architecture.

关键词： Buffer storage Hip internet Microarchitecture Pipelines Random access memory Registers BUFFER STORAGE random access machine IPv6 Registers Microarchitecture pipeline hardware architecture Hip internets user datagram protocol/internet protocol Uridine Diphosphate PROCESSOR piping

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