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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Laboratorní úlohy v prostředí OPNET pro předmět Pokročilé komunikační techniky / Laboratory exercises in OPNET environment for Advanced communication techniques course

Mikulecký, Miloš January 2012 (has links)
The Master´s Thesis describes laboratory exercises for Advanced communication technology subject. Exercises are created in Opnet IT Guru aplication. Each exercise has detailed instructions according to which can be realized whole exercise. Each exercise also contains individual task, where are checked knowledge gained from studies of example exercise. Exercises are based on issues of routing in autonomous systems, protocol BGP, protocols TCP and UDP and issues of QoS in IP networks.
12

Profiling Glycosyltransferase Peptide Substrate Specificities: Studies on ppGalNAc T1, T2, T10, and T-synthase That Initiate Mucin-Type O-Glycosylation

Perrine, Cynthia L. 29 December 2009 (has links)
No description available.
13

Modelos de trafego para fluxos gerados pelo protocolo UDP / Traffic models for UDP streams

Ostrowsky, Larissa Oliveira 12 December 2005 (has links)
Orientador: Nelson Luis Sadanha da Fonseca / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Computação / Made available in DSpace on 2018-08-06T04:44:40Z (GMT). No. of bitstreams: 1 Ostrowsky_LarissaOliveira_M.pdf: 1550430 bytes, checksum: 823c0f45a69f06a55a90d4abbffa7e24 (MD5) Previous issue date: 2005 / Resumo: Uma característica importante do tráfego gerado pelo protocolo Internet Protocol (IP) é a existência de padrões scaling, que impactam significantemente o desempenho dos mecanismos de controle de tráfego e que, por isto vem sendo foco de atenção de diversas pesquisas. A natureza scaling do tráfego IP tem sido alvo de bastante polêmica. Em pequenas escalas de tempo o tráfego IP é altamente variável e a variabilidade difere da natureza fractal encontrada em grandes escalas de tempo, não existindo ainda um consenso em relação a natureza do tráfego IP nestas pequenas escalas de tempo. No presente estudo, foram revisadas as evidências da multifractalidade nas pequenas escalas de tempo, através da análise experimental de diversos traços de tráfego real. Constatou-se que não se pode generalizar a natureza dos fluxos do protocolo IP e do protocolo Transmission Control Protocol (TCP) como monofractal ou como multifractal, enquanto que a natureza do fluxo do protocolo User Datagram Protocol (UDP) é sempre multifractal. O crescente uso do protocolo UDP pelas emergentes aplicações que necessitam requisitos de tempo real altera consideravelmente a natureza scaling do tráfego IP, dado que este tipo de tráfego n¿ao reage a situações de congestionamento. Apesar de existirem diversos modelos para tráfego TCP, pouca atenção tem sido dada a modelagem de tráfego UDP. Outra contribuição desta dissertação é a proposta de um modelo de tráfego para fluxos UDP, desenvolvido a partir da caracterização das distribuições estatísticas de traços reais. Este modelo consegue reproduzir com precisão várias características do tráfego UDP real, inclusive a natureza scaling. O modelo foi validado via simulação e a precisão dos resultados do modelo para avaliar um sistema de filas foi comparada às precisões do Modelo Wavelet Multifractal (MWM) e do Modelo MAP Multifractal. Resultados indicam que o modelo proposto reproduz melhor a ocupação em uma fila para diferentes capacidades de armazenamento e taxas de serviço do que os outros modelos avaliados. A geração de traços sintéticos a partir do modelo adotado pode ser realizada em pequenos intervalos de tempo. Assim, o modelo proposto é adequado para o dimensionamento de recursos da rede e provisionamento de Qualidade de serviço / Abstract: An important characteristic of the traffic generated by IP protocol is the existence of scaling, since it has great impact on the performance of traffic control mechanism. Therefore, it has been the focus of attention in many researches. The scaling nature of IP traffic has generated lots of controversy. At small time scales the traffic is very irregular and the variability is different from that found in fractal nature at larges scales. There is no general agreement in relation to the nature of the traffic at these small time scales. In the present study, the evidences of multifractality at small time scales were revised via experimental analyses of several real traffic traces. It was concluded that is not possible to generalize that the nature of IP and TCP flows is either monofractal or multifractal, while the nature of the UDP flows is always multifractal. The increasing use of the UDP protocol by real time applications is changing substantially the scaling nature of IP traffic, since this type of traffic does not react to congestion situations. Although there are models for TCP traffic, not much attention has been given to the modeling of UDP flows. Another contribution of this dissertation is a proposition of UDP traffic model, developed from the characterization of the statistics distributions of real traces. This model can reproduce with precision several characteristics of UDP real traffic, including the scaling nature. The model was validated via simulation and the precision of results of the model was compared with the precisions of the MWM and MAP models. Results indicate that the proposed model better reproduces the queue occupation for different storage capacities and service rates then the others evaluated models. The generation of synthetic traces using the adopted model can be realized with low execution times. Thus, the proposed model is acceptable to the dimension of network resources measurement and to provide Quality of Service / Mestrado / Redes e Multimidia / Mestre em Ciência da Computação
14

Synthons of UDP-<i>N</i>-acetyl-L-Fucosamine (UDP-L-FucNAc) as potential inhibitors of <i>Staphylococcus aureus</i> Capsular Polysaccharide Biosynthesis

Ngoje, Philemon O. 10 September 2015 (has links)
No description available.
15

Gene regulation of UDP-glucose synthesis and metabolism in plants

Johansson, Henrik January 2003 (has links)
<p>Photosynthesis captures light from the sun and converts it into carbohydrates, which are utilised by almost all living organisms. The conversion between the different forms of carbohydrates is the basis to form almost all biological molecules.</p><p>The main intention of this thesis has been to study the role of UDP-glucose in carbohydrate synthesis and metabolism, and in particular the genes that encode UDP-glucose pyrophosphorylase (UGPase) and UDP-glucose dehydrogenase (UGDH) in plants and their regulation. UGPase converts glucose-1-phosphate to UDP-glucose, which can be utilised for sucrose synthesis, or cell wall polysaccharides among others. UGDH converts UDP-glucose to UDP-glucuronate, which is a precursor for hemicellulose and pectin. As model species I have been working with both Arabidopsis thaliana and poplar.</p><p>Sequences for two full-length EST clones of Ugp were obtained from both Arabidopsis and poplar, the cDNAs in Arabidopsis correlate with two genes in the Arabidopsis genomic database.</p><p>The derived protein sequences are 90-93% identical within each plants species and 80-83% identical between the two species.</p><p>Studies on Ugp showed that the expression is up-regulated by Pi-deficiency, sucrose-feeding and by light exposure in Arabidopsis. Studies with Arabidopsis plants with mutations in sugar/ starch- and Pi-content suggested that the Ugp expression is modulated by an interaction of signals derived from Pi-deficiency, sugar content and light/ dark conditions, where the signals act independently or inhibiting each other, depending on conditions. Okadaic acid, a known inhibitor of certain classes of protein phosphatases, prevented the up-regulation of Ugp by Pi-deficiency and sucrose-feeding. In poplar, sucrose also up-regulated the expression of Ugp. When poplar and Arabidopsis were exposed to cold, an increase of Ugp transcript content was detected as well as an increase in UGPase protein and activity. In poplar, Ugp was found to be expressed in all tissues that were examined (differentiating xylem, phloem, apical leaves and young and mature leaves).</p><p>By using antisense strategy, Arabidopsis plants that had a decrease in UGPase activity of up to 30% were obtained. In the antisense plants, the soluble carbohydrate content was reduced in the leaves by at least 50%; in addition the starch content decreased. Despite the changes in carbohydrate content, the growth rate of the antisense plants was not changed compared to wild type plants under normal growth conditions. However, in the antisense lines the UGPase activity and protein content in sliliques and roots increased, perhaps reflecting compensatory up-regulation of second Ugp gene. This correlates with a slightly larger molecular mass of UGPase protein in roots and siliques when compared to that in leaves. Maximal photosynthesis rates were similar for both wild type and antisense plants, but the latter had up to 40% lower dark respiration and slightly lower quantum yield than wild type plants.</p><p>Two Ugdh cDNAs from poplar and one from Arabidopsis were sequenced. The highest Ugdh expression was found in xylem and younger leaves. Expression data from sugar and osmoticum feeding experiment in poplar suggested that the Ugdh expression is regulated via an osmoticumdependent pathway.</p>
16

Gene regulation of UDP-glucose synthesis and metabolism in plants

Johansson, Henrik January 2003 (has links)
Photosynthesis captures light from the sun and converts it into carbohydrates, which are utilised by almost all living organisms. The conversion between the different forms of carbohydrates is the basis to form almost all biological molecules. The main intention of this thesis has been to study the role of UDP-glucose in carbohydrate synthesis and metabolism, and in particular the genes that encode UDP-glucose pyrophosphorylase (UGPase) and UDP-glucose dehydrogenase (UGDH) in plants and their regulation. UGPase converts glucose-1-phosphate to UDP-glucose, which can be utilised for sucrose synthesis, or cell wall polysaccharides among others. UGDH converts UDP-glucose to UDP-glucuronate, which is a precursor for hemicellulose and pectin. As model species I have been working with both Arabidopsis thaliana and poplar. Sequences for two full-length EST clones of Ugp were obtained from both Arabidopsis and poplar, the cDNAs in Arabidopsis correlate with two genes in the Arabidopsis genomic database. The derived protein sequences are 90-93% identical within each plants species and 80-83% identical between the two species. Studies on Ugp showed that the expression is up-regulated by Pi-deficiency, sucrose-feeding and by light exposure in Arabidopsis. Studies with Arabidopsis plants with mutations in sugar/ starch- and Pi-content suggested that the Ugp expression is modulated by an interaction of signals derived from Pi-deficiency, sugar content and light/ dark conditions, where the signals act independently or inhibiting each other, depending on conditions. Okadaic acid, a known inhibitor of certain classes of protein phosphatases, prevented the up-regulation of Ugp by Pi-deficiency and sucrose-feeding. In poplar, sucrose also up-regulated the expression of Ugp. When poplar and Arabidopsis were exposed to cold, an increase of Ugp transcript content was detected as well as an increase in UGPase protein and activity. In poplar, Ugp was found to be expressed in all tissues that were examined (differentiating xylem, phloem, apical leaves and young and mature leaves). By using antisense strategy, Arabidopsis plants that had a decrease in UGPase activity of up to 30% were obtained. In the antisense plants, the soluble carbohydrate content was reduced in the leaves by at least 50%; in addition the starch content decreased. Despite the changes in carbohydrate content, the growth rate of the antisense plants was not changed compared to wild type plants under normal growth conditions. However, in the antisense lines the UGPase activity and protein content in sliliques and roots increased, perhaps reflecting compensatory up-regulation of second Ugp gene. This correlates with a slightly larger molecular mass of UGPase protein in roots and siliques when compared to that in leaves. Maximal photosynthesis rates were similar for both wild type and antisense plants, but the latter had up to 40% lower dark respiration and slightly lower quantum yield than wild type plants. Two Ugdh cDNAs from poplar and one from Arabidopsis were sequenced. The highest Ugdh expression was found in xylem and younger leaves. Expression data from sugar and osmoticum feeding experiment in poplar suggested that the Ugdh expression is regulated via an osmoticumdependent pathway.
17

IP Protocols in Telemetry Systems

Weaver, Robert Jr., Snyder, Ed 10 1900 (has links)
ITC/USA 2006 Conference Proceedings / The Forty-Second Annual International Telemetering Conference and Technical Exhibition / October 23-26, 2006 / Town and Country Resort & Convention Center, San Diego, California / This paper is intended to provide background into networking and IP protocols for non-IT personnel. It is not a study of networking and related protocols, as each of these topics would require a much longer period of time to explain. Addressed are considerations that should be required prior to locking a network design into a specific architecture. The systems available today, for the same cost as a good home PC, are becoming capable of performing critical tasks. It is highly recommended that the personnel who know the most about the data and how it will be used communicate with the personnel that know the network. Failing to explain or understand the networking nomenclature causes considerable wasted time and money. This paper is intended to encourage communications between the data creators and the data movers. We also want to demonstrate how new systems, hardware and software, designed to work with existing network devices used in non–telemetry applications, can make implementing IP in telemetry networks easier.
18

Network Design Considerations in Telemetry Systems

Grebe, Andy, Klein, Wayne 10 1900 (has links)
ITC/USA 2007 Conference Proceedings / The Forty-Third Annual International Telemetering Conference and Technical Exhibition / October 22-25, 2007 / Riviera Hotel & Convention Center, Las Vegas, Nevada / In today’s world, computer networking has become common place both in industry as well as home, however all networks are not the same! The Telemetry world, like with many industries, has critical design considerations that need to be evaluated when you begin a new system or just adding on to a current infrastructure. This paper is intended to outline needed considerations when planning or implementing a network design in Telemetry Systems. These applications can range from sensor data transport through High Definition/High Speed Video applications.
19

PACKET-BASED TELEMETRY NETWORKS OVER LEGACY SYSTEMS

O’Connell, Tim 10 1900 (has links)
ITC/USA 2005 Conference Proceedings / The Forty-First Annual International Telemetering Conference and Technical Exhibition / October 24-27, 2005 / Riviera Hotel & Convention Center, Las Vegas, Nevada / The telemetry industry anticipates the tremendous potential value of adding full networking capability to telemetry systems. However, much of this potential can be realized while working with legacy equipment. By adding modules that interface transparently to existing equipment, continuous telemetry data can be encapsulated in discrete packets for over the air transmission. Packet fields can include header, sequence number and bytes for error detection and correction. The RF packet is transmitted without gaps through a standard serial interface and rate adjusted for the packet overhead – effectively making packetization transparent to a legacy system. The receiver unit performs packet synchronization, error correction, extraction of stream quality metrics and re-encapsulation of the payload data into an internet protocol (IP) packet. These standard packets can then be sent over the existing network transport system to the range control center. At the range control center, the extracted stream quality metrics are used to select the best telemetry source in real-time. This paper provides a general discussion of the path to a fully realized, packet-based telemetry network and a brief but comprehensive overview of the Hypernet system architecture as a case study.
20

Standardize Your IP Traffic with TMOIP

Grebe, Andy 10 1900 (has links)
ITC/USA 2009 Conference Proceedings / The Forty-Fifth Annual International Telemetering Conference and Technical Exhibition / October 26-29, 2009 / Riviera Hotel & Convention Center, Las Vegas, Nevada / With the emergence of higher bandwidth Ethernet networks on ranges, many ranges are converting their data transport from ATM(Asynchronous Transfer Mode) networks to Ethernet networks. Both networks have their respective advantages and disadvantages, however one reoccurring issue is product interoperability. The RCC (Range Commanders Council) TTG (Telecommunications and Timing Group) created the Telemetry over IP (TMoIP 218-07) solution with input from various ranges and vendors to solve this issue. This specification allows ranges to use different vendors together for Telemetry over Ethernet, based on specific needs at each site. This paper targets those who are thinking about converting from ATM to Ethernet networks.

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