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Comparação entre os tratamentos adjuvantes no pterígio primário ressecado: uma network metanálise / Comparison among adjuvant treatments for primary pterygium: a network metanalysisFonseca, Ellen Carrara 07 April 2017 (has links)
O pterígio é uma degeneração benigna da conjuntiva, que se estende em direção à córnea e acomete principalmente adultos habitantes de regiões intertropicais. A prevalência mundial varia de 0,7 a 31%. A patogênese exata permanece incerta, mas evidências atuais sugerem a participação de fatores genéticos e ambientais, principalmente a exposição crônica à radiação ultravioleta. O tratamento pode ser clínico, com uso de colírios para melhora dos sintomas, ou cirúrgico. Até os anos de 1980, a técnica de ressecção do pterígio com manutenção de área de esclera nua era predominante, porém apresentava taxas muito elevadas de recidiva. Desde então, tem-se procurado técnicas adjuvantes a essa para obtenção de melhores resultados e redução do número de recorrência. O presente estudo busca, por meio de comparações diretas e indiretas da network metanálise, identificar qual, dentre as várias técnicas utilizadas, seria a melhor a ser empregada. Após pesquisa em bases de dados foram selecionados 24 ensaios clínicos randomizados, computando 1815 olhos em 1668 pacientes, sendo possível comparar os seguintes tratamentos adjuvantes à técnica de esclera nua: associação de 5-Fluorouracil (5-FU), Betaterapia, Mitomicina C (MMC) em diferentes concentrações e Ciclosporina, além de transplante de membrana amniótica (TMA) e enxerto conjuntival, também associado ao uso de Bevacizumab, MMC e Ciclosporina. Foi possível realizar comparações diretas entre os seguintes tipos de intervenções: esclera nua versus esclera nua + Ciclosporina gotas 0,05%, enxerto conjuntival versus esclera nua + MMC 0,02% intraoperatória, enxerto conjuntival versus transplante de membrana amniótica, esclera nua versus esclera nua + MMC 0,02% intraoperatória e esclera nua versus enxerto conjuntival, sendo considerados os melhores, respectivamente: esclera nua + Ciclosporina gotas 0,05%, enxerto conjuntival, enxerto conjuntival, esclera nua + MMC 0,02% e enxerto conjuntival. Em relação à network metanálise, o ranqueamento ordenado do melhor para o pior procedimento na redução de recidiva foi o seguinte: enxerto conjuntival + Ciclosporina gotas 0,05%, esclera nua associada à MMC < 0,02%, esclera nua + Betaterapia (dose única de 2500 cGy), enxerto conjuntival + Betaterapia (dose única de 1000 cGy), esclera nua + MMC gotas 0,02%, enxerto conjuntival, esclera nua + MMC > 0,02%, esclera nua + Ciclosporina gotas 0,05%, esclera nua + 5FU intraoperatório 5%, transplante de membrana amniótica, esclera nua + MMC 0,02%, enxerto conjuntival + Bevacizumab gotas 0,05%, esclera nua + Bevacizumab e esclera nua. Em conclusão, diante das inúmeras possibilidades de combinações de tratamento para o pterígio, foi possível se estabelecer, a partir das técnicas comparadas em estudos clínicos publicados e disponibilidade dos recursos em cada serviço, o tratamento com menor recidiva. / Pterygium is a benign conjunctival degeneration towards the cornea which affects mostly adults who live in the intertropical regions. World prevalence is between 0,7 and 31%. The exact pathogenesis remains unclear but it´s known that genetics and environmental factors may predispose to this condition, specially cronic exposure to ultraviolet radiation which can cause oxidative stress and increase growth factors production. Treatment can be simptomatic, with eye drops, or surgery can be performed. Until the 80´s pterygium ressection leaving an area of bare sclera was the main surgic procedure but it led to high rates of recurrency. Since then, adjuvants techniques have been studied in order to improve the results by decreasing recurrency rates. The aim of this paper is to try to identify, among several adjuvant procedures, which would be the best to avoid recurrency. To acomplish that we performed a network metanalisis. After critical search in data bases we selected 24 randomized clinical trials that included 1815 eyes of 1668 patients. We were able to compare the following adjuvant treatments to bare sclera technique: use of 5-Fluorouracil (5-FU), Bethaterapy, Mytomicyn C (MMC) in different concentrations, Cyclosporine, Amniotic Membrane Transplantation (AMT) and Conjunctival Autograft (CAG) alone or associated to Bevacizumab, MMC and Cyclosporine. The following direct comparisons were made: bar esclera versus bar esclera + Ciclosporyne eye drops 0.05%, conjunctival autograft versus bar esclera + intraoperative MMC 0.02%, conjunctival autograft versus amniotic membrane transplantation, bare sclera versus bar esclera + intraoperative MMC 0.02% and conjunctival autograft versus bare sclera with better results, respectivelly, in: bare sclera + Ciclosporyne 0.05% eye drops, conjunctival autograft, conjunctival autograft, bare sclera + MMC 0.02% and conjunctival autograft. Regarding the network metanalysis, the rank from best to worst treatment is: conjunctival autograft + Ciclosporyne eye drops 0.05%, bare sclera + MMC < 0.02%, bare sclera + Betatherapy (2500 cGy single dose), conjunctival autograft + Betatherapy (1000 cGy single dose), bare sclera + MMC 0.02% eye drops, conjunctival autograft, bare sclera + intraoperative MMC > 0.02%, bare sclera + Ciclosporyne eye drops 0.05%, bare sclera + intraoperative 5FU 5%, amniotic membrane transplantation, bare sclera + intraoperative MMC 0.02%, conjunctival autograft + Bevacizumab eye drops 0.05%, bare sclera + Bevacizumab eye drops 0.05% and bare sclera alone. In conclusion, given the numerous possible combinations of treatment for pterygium, it is possible to establish from the techniques compared in published clinical trials and availability of resources in each service, treatment with lower recurrence.
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Endocrine inspired control of wireless sensor networks : deployment and analysisBlanchard, Tom January 2016 (has links)
Many domains, such as geographical and biological sciences, can benefit from the ability of wireless sensor networks to provide long term, high temporal and spatial resolution sensing. Such networks must be able to trade off various requirements against each other to extend network lifetime while still providing useful, good quality data. The challenges faced by equipment in the field can very unpredictable and therefore a wireless sensor network should be able to cope with these challenges and return to a balanced state. Using readily available, low-cost components, this work was inspired by the human endocrine systems ability to maintain homeostasis, or balance, in a large number of parameters simultaneously. This work developed a number of endocrine inspired methods. These were aimed both at improving the power usage of nodes in a wireless sensor network and improving the quality of the data collected. Methods for improving power consumption and data quality were achieved. These methods were successfully deployed, for the purposes of environmental monitoring on a mesh network consisting of 20 nodes, for a period of almost 6 months. Analysis showed that the use of power by individual nodes was improved and that the endocrine inspired methods, aimed at improving data quality, were successful. Node lifetimes were extended, duplicate data reduced and the quality of data improved. The use of low-cost, readily available components was largely successful, and challenges and changes to these components were discussed.
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Network Coding in Multihop Wireless Networks: Throughput Analysis and Protocol DesignYang, Zhenyu 29 April 2011 (has links)
Multi-hop wireless networks have been widely considered as promising approaches to provide more convenient Internet access for their easy deployment, extended coverage, and low deployment cost. However, providing high-speed and reliable services in these networks is challenging due to the unreliable wireless links, broadcast nature of wireless transmissions, and frequent topology changes. On the other hand, network coding (NC) is a technique that could significantly improve the network throughput and the transmission reliability by allowing intermediate nodes to combine received packets. More recently proposed symbol level network coding (SLNC), which combines packets at smaller symbol scale, is a more powerful technique to mitigate the impact of lossy links and packet collisions in wireless networks. NC, especially SLNC, is thus a particular effective approach to providing higher data rate and better transmission reliability for applications such as mobile content distribution in multihop wireless networks. This dissertation focuses on exploiting NC in multihop wireless networks. We studied the unique features of NC and designed a suite of distributed and localized algorithms and protocols for content distribution networks using NC and SLNC. We also carried out a theoretical study on the network capacity and performance bounds achievable by SLNC in mobile wireless networks. We proposed CodeOn and CodePlay for popular content distribution and live multimedia streaming (LMS) in vehicular ad hoc networks (VANETs), respectively, where many important practical factors are taken into consideration, including vehicle distribution, mobility pattern, channel fading and packet collision. Specifically, CodeOn is a novel push based popular content distribution scheme based on SLNC, where contents are actively broadcast to vehicles from road side access points and further distributed among vehicles using a cooperative VANET. In order to fully enjoy the benefits of SLNC, we proposed a suite of techniques to maximize the downloading rate, including a prioritized and localized relay selection mechanism where the selection criteria is based on the usefulness of contents possessed by vehicles, and a lightweight medium access protocol that naturally exploits the abundant concurrent transmission opportunities. CodePlay is designed for LMS applicaitions in VANETs, which could fully take advantage of SLNC through a coordinated local push mechanism. Streaming contents are actively disseminated from dedicated sources to interested vehicles via local coordination of distributively selected relays, each of which will ensure smooth playback for vehicles nearby. CodeOn pursues a single objective of maximizing downloading rate, while CodePlay improves the performance of LMS service in terms of streaming rate, service delivery delay, and bandwidth efficiency simultaneously. CodeOn and CodePlay are among the first works that exploit the features of SLNC to simplify the protocol design whilst achieving better performance. We also developed an analytical framework to compute the expected achievable throughput of mobile content distribution in VANETs using SLNC. We presented a general analytical model for the expected achievable throughput of SLNC in a static wireless network based on flow network theory and queuing theory. Then we further developed the model to derive the expected achievable accumulated throughput of a vehicle driving through the area of interest under a mobility pattern. Our proposed framework captures the effects of multiple practical factors, including vehicle distribution and mobility pattern, channel fading and packet collision, and we characterized the impacts of those factors on the expected achievable throughput. The results from this research are not only of interest from theoretical perspective but also provide insights and guidelines on protocol design in SLNC-based networks.
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Using Network Application Behavior to Predict PerformanceMa, Chunling 16 April 2008 (has links)
Today`s continuously growing Internet requires users and network applications to have knowledge of network metrics. This knowledge is critical for decision making during the usage of network applications. This thesis studies application related network metrics. The major approach in this work is to examine the traffic between a simulated user and network applications. We use the historical data collected from previous usage of network applications to make predictions for future usage of those applications. We also use the historical data obtained from a given application to make predictions about another application. Prediction mechanisms require us to make parameter choices so that certain weights can be placed on historical data versus current data. We study these different choices and use the values from our best experimental results. From these studies we conclude that our data prediction is quite accurate and remains stable over a range of parameter choices. The use of shared routing paths between users and network applications are explored in the performance prediction of applications. Only some servers at the same locations show similar prediction results. The network applications studied are also varied, including web, streaming, DNS, etc. We see whether sharing information obtained from different applications can be used to make predictions of application performance. However, we observe limited success in predictions across applications.
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An analysis of emotion-exchange motifs in multiplex networks during emergency eventsKusen, Ema, Strembeck, Mark January 2019 (has links) (PDF)
In this paper, we present an analysis of the emotion-exchange patterns that arise from
Twitter messages sent during emergency events. To this end, we performed a
systematic structural analysis of the multiplex communication network that we derived
from a data-set including more than 1.9 million tweets that have been sent during five
recent shootings and terror events. In order to study the local communication
structures that emerge as Twitter users directly exchange emotional messages, we
propose the concept of emotion-exchangemotifs. Our findings suggest that
emotion-exchange motifs which contain reciprocal edges (indicating online
conversations) only emerge when users exchange messages that convey anger or fear,
either in isolation or in any combination with another emotion. In contrast, the
expression of sadness, disgust, surprise, as well as any positive emotion are rather
characteristic for emotion-exchange motifs representing one-way communication
patterns (instead of online conversations). Among other things, we also found that a
higher structural similarity exists between pairs of network layers consisting of one
high-arousal emotion and one low-arousal emotion, rather than pairs of network layers
belonging to the same arousal dimension.
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Uma rede Ethernet on chip parametrizável para aplicações DSP em FPGA / An Ethernet network on configurable DSP chip for applications in FPGACunha Junior, Hélio Fernandes da 03 June 2015 (has links)
Com o crescimento acelerado da complexidade das aplicações e softwares que exigem alto desempenho, o hardware e sua arquitetura passou por algumas mudanças para que pudesse atender essa necessidade. Uma das abordagens propostas e desenvolvidas para suportar essas aplicações, foi a integração de mais de um core de processamento em um único circuito integrado. Inicialmente, a comunicação utilizando barramento foi escolhida, pela sua vantagem de reuso comparado a ponto a ponto. No entanto, com o aumento acelerado da quantidade de cores nos Systems-on-Chip (SoC), essa abordagem passou a apresentar problemas para suportar a comunicação interna. Uma alternativa que vem sendo explorada é a Network-on-Chip (NoC), uma abordagem que propõe utilizar o conhecimento de redes comuns em projetos de comunicação interna de SoC. Esse trabalho fornece uma arquitetura de NoC completa, configurável, parametrizável e no padrão Ethernet. Os três módulos básicos da NoC, Network Adapter (NA), Link e Switch, são implementados e disponibilizados. Os resultados foram obtidos utilizando o FPGA Stratix IV da Altera. As métricas de desempenho utilizadas para validação da NoC são a área no FPGA e o atraso na comunicação. Os parâmetros disponibilizados são referentes as configurações dos módulos desenvolvidos, considerando características apresentadas de aplicações DSP (Digital Signal Processing). O experimento utilizando dois NAs, dois cores e um Switch precisou de 7310 ALUTs do FPGA EP4SGX230KF40C2ES o que corresponde a 4% dos seus recursos lógicos. O tempo gasto para a transmissão de um quadro ethernet de 64 Bytes foi de 422 ciclos de clock a uma frequência de 50MHz. / With the accelerated growth of the complexity of the software and applications that require high performance, hardware and its architecture has undergone a few changes so it could meet that need. One of the proposals and approaches developed to support these applications, was the integration of more than one core processing in a single integrated circuit. Initially, the bus communication architecture was chosen, using for its reuse benefit compared to point-to-point. However, with the cores number increase in Systems-on-Chip (SoC), this approach began to present problems to support internal communication. An alternative that has been explored is the Network-on-Chip (NoC), an approach that proposes to use knowledge of common networks on internal communication projects of SOC. This dissertation focuses is to provide a complete NoC architecture, configurable, customizable and on standard Ethernet. The three NoC basic modules, Network Adapter (NA), Link and Switch, are implemented. The results were obtained using the Stratix IV FPGA. The performance metrics used for NoC validation are silicon area and latency. The available parameters are related to developed modules settings, considering features presented of DSP applications. The experiment using two NA, two cores and one Switch needed 7310 FPGA ALUTs which corresponds to 4% of their logical resources. The time for the transmission of an ethernet frame of 64 Bytes was 422 clock cycles at 50 MHz.
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Towards Trouble-Free Networks for End UsersKim, Kyung Hwa January 2018 (has links)
Network applications and Internet services fail all too frequently. However, end users cannot effectively identify the root cause using traditional troubleshooting techniques due to the limited capability to distinguish failures caused by local network elements from failures caused by elements located outside the local area network.
To overcome these limitations, we propose a new approach, one that leverages collaboration of user machines to assist end users in diagnosing various failures related to Internet connectivity and poor network performance.
First, we present DYSWIS ("Do You See What I See?"), an automatic network fault detection and diagnosis system for end users. DYSWIS identifies the root cause(s) of network faults using diagnostic rules that consider diverse information from multiple nodes. In addition, the DYSWIS rule system is specially designed to support crowdsourced and distributed probes. We also describe the architecture of DYSWIS and compare its performance with other tools. Finally, we demonstrate that the system successfully detects and diagnoses network failures which are difficult to diagnose using a single-user probe.
Failures in lower layers of the protocol stack also have the potential to disrupt Internet access; for example, slow Internet connectivity is often caused by poor Wi-Fi performance. Channel contention and non-Wi-Fi interference are the primary reasons for this performance degradation. We investigate the characteristics of non-Wi-Fi interference that can severely degrade Wi-Fi performance and present WiSlow ("Why is my Wi-Fi slow?"), a software tool that diagnoses the root causes of poor Wi-Fi performance. WiSlow employs user-level network probes and leverages peer collaboration to identify the physical location of these causes. The software includes two principal methods: packet loss analysis and 802.11 ACK number analysis. When the issue is located near Wi-Fi devices, the accuracy of WiSlow exceeds 90%.
Finally, we expand our collaborative approach to the Internet of Things (IoT) and propose a platform for network-troubleshooting on home devices. This platform takes advantage of built-in technology common to modern devices --- multiple communication interfaces. For example, when a home device has a problem with an interface it sends a probe request to other devices using an alternative interface. The system then exploits cooperation of both internal devices and remote machines. We show that this approach is useful in home networks by demonstrating an application that contains actual diagnostic algorithms.
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Inter-domain routing: pricing policy and route selection using neural networks.January 1997 (has links)
by Wong Leung-Chung Chris. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1997. / Includes bibliographical references (leaves 86-[92]). / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Routing Overview --- p.2 / Chapter 1.2 --- Routing in the Internet --- p.5 / Chapter 1.2.1 --- Inter-Domain Routing --- p.6 / Chapter 1.2.2 --- Intra-Domain Routing --- p.7 / Chapter 1.2.3 --- The Future Trend --- p.7 / Chapter 2 --- Inter-Domain Routing --- p.9 / Chapter 2.1 --- Inter-Domain Routing Protocols --- p.9 / Chapter 2.1.1 --- Exterior Gateway Protocol (EGP) --- p.10 / Chapter 2.1.2 --- Border Gateway Protocol (BGP) --- p.11 / Chapter 2.1.3 --- Inter-Domain Policy Routing (IDPR) --- p.12 / Chapter 2.1.4 --- Other Protocols --- p.13 / Chapter 2.2 --- The Need for Pricing on Inter-Domain Routing Protocols --- p.13 / Chapter 2.3 --- Pricing Scheme on the Inter-Domain level --- p.15 / Chapter 2.4 --- Routing Protocols to Support Pricing on the Internet --- p.16 / Chapter 2.4.1 --- Routing Towards Multiple-Additive Metrics --- p.16 / Chapter 2.4.2 --- "Network Model, Notations and Assumptions" --- p.16 / Chapter 2.4.3 --- The Problem Statement --- p.18 / Chapter 3 --- Application of Neural Nets in Route Selection --- p.20 / Chapter 3.1 --- Neural Network (NN) Overview --- p.20 / Chapter 3.1.1 --- Brief History on Neural Network Research --- p.20 / Chapter 3.1.2 --- Definition of Neural Network --- p.21 / Chapter 3.1.3 --- Neural Network Architectures --- p.22 / Chapter 3.1.4 --- Transfer Fucntion of a Neuron --- p.24 / Chapter 3.1.5 --- Learning Methods --- p.25 / Chapter 3.1.6 --- Applications in Telecommunications --- p.26 / Chapter 3.2 --- Review on the Applications of Neural Networks in Packet Routing --- p.27 / Chapter 3.2.1 --- The JEB Branch --- p.27 / Chapter 3.2.2 --- The Hopfield/Energy Minimization Branch (HEM) --- p.29 / Chapter 3.2.3 --- Supervised Learning (SL) --- p.34 / Chapter 3.3 --- Discussions --- p.35 / Chapter 4 --- Route Selection as “Link-state´ح Classification --- p.36 / Chapter 4.1 --- Multi-Layer Feedforward Network (MLFN) --- p.37 / Chapter 4.1.1 --- Function Approximation Power of MLFN --- p.38 / Chapter 4.1.2 --- Choosing MLFN parameters..........´ب --- p.40 / Chapter 4.1.3 --- Trailing a MLFN --- p.41 / Chapter 4.2 --- The Utility Function --- p.43 / Chapter 4.3 --- The Neural Network Architecture --- p.46 / Chapter 4.3.1 --- Routing Graph Representation with Successor Sequence Table (SST) --- p.46 / Chapter 4.3.2 --- The Neural Network Layout --- p.52 / Chapter 4.3.3 --- How the Neural Network Controller Works --- p.55 / Chapter 4.3.4 --- Training --- p.56 / Chapter 4.4 --- Simulation --- p.56 / Chapter 4.4.1 --- Performance Parameters --- p.56 / Chapter 4.4.2 --- Simulation Results --- p.57 / Chapter 4.5 --- Conclusions and Discussions --- p.70 / Chapter 5 --- Route Selection as Energy Minimization - A Theoretical Study --- p.73 / Chapter 5.1 --- The Hopfield/Tank NN Model --- p.73 / Chapter 5.2 --- Boltzman's Machine --- p.76 / Chapter 5.3 --- Boltzman's Machine Model for Multiple-Metrices Routing --- p.79 / Chapter 5.4 --- Conclusions --- p.82 / Chapter 6 --- Conclusions --- p.84 / Bibliography --- p.86
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Advances in Deflection Routing based Network on Chips / Fortschritte bei Deflection Routing basierten Network on ChipsRunge, Armin January 2017 (has links) (PDF)
The progress which has been made in semiconductor chip production in recent years enables a multitude of cores on a single die. However, due to further decreasing structure sizes, fault tolerance and energy consumption will represent key challenges. Furthermore, an efficient communication infrastructure is indispensable due to the high parallelism at those systems. The predominant communication system at such highly parallel systems is a Network on Chip (NoC). The focus of this thesis is on NoCs which are based on deflection routing. In this context, contributions are made to two domains, fault tolerance and dimensioning of the optimal link width. Both aspects are essential for the application of reliable, energy efficient, and deflection routing based NoCs.
It is expected that future semiconductor systems have to cope with high fault probabilities. The inherently given high connectivity of most NoC topologies can be exploited to tolerate the breakdown of links and other components. In this thesis, a fault-tolerant router architecture has been developed, which stands out for the deployed interconnection architecture and the method to overcome complex fault situations. The presented simulation results show, all data packets arrive at their destination, even at high fault probabilities. In contrast to routing table based architectures, the hardware costs of the herein presented architecture are lower and, in particular, independent of the number of components in the network.
Besides fault tolerance, hardware costs and energy efficiency are of great importance. The utilized link width has a decisive influence on these aspects. In particular, at deflection routing based NoCs, over- and under-sizing of the link width leads to unnecessary high hardware costs and bad performance, respectively. In the second part of this thesis, the optimal link width at deflection routing based NoCs is investigated. Additionally, a method to reduce the link width is introduced. Simulation and synthesis results show, the herein presented method allows a significant reduction of hardware costs at comparable performance. / Die Fortschritte der letzten Jahre bei der Fertigung von Halbleiterchips ermöglichen eine Vielzahl an Rechenkernen auf einem einzelnen Chip. Die in diesem Zusammenhang immer weiter sinkenden Strukturgrößen führen jedoch dazu, dass Fehlertoleranz und Energieverbrauch zentrale Herausforderungen darstellen werden. Aufgrund der hohen Parallelität in solchen Systemen, ist außerdem eine leistungsfähige Kommunikationsinfrastruktur unabdingbar. Das in diesen hochgradig parallelen Systemen überwiegend eingesetzte System zur Datenübertragung ist ein Netzwerk auf einem Chip (engl. Network on Chip (NoC)). Der Fokus dieser Dissertation liegt auf NoCs, die auf dem Prinzip des sog. Deflection Routing basieren. In diesem Kontext wurden Beiträge zu zwei Bereichen geleistet, der Fehlertoleranz und der Dimensionierung der optimalen Breite von Verbindungen. Beide Aspekte sind für den Einsatz zuverlässiger, energieeffizienter, Deflection Routing basierter NoCs essentiell.
Es ist davon auszugehen, dass zukünftige Halbleiter-Systeme mit einer hohen Fehlerwahrscheinlichkeit zurecht kommen müssen. Die hohe Konnektivität, die in den meisten NoC Topologien inhärent gegeben ist, kann ausgenutzt werden, um den Ausfall von Verbindungen und anderen Komponenten zu tolerieren. Im Rahmen dieser Arbeit wurde vor diesem Hintergrund eine fehlertolerante Router-Architektur entwickelt, die sich durch das eingesetzte Verbindungsnetzwerk und das Verfahren zur Überwindung komplexer Fehlersituationen auszeichnet. Die präsentierten Simulations-Ergebnisse zeigen, dass selbst bei sehr hohen Fehlerwahrscheinlichkeiten alle Datenpakete ihr Ziel erreichen. Im Vergleich zu Router-Architekturen die auf Routing-Tabellen basieren, sind die Hardware-Kosten der hier vorgestellten Router-Architektur gering und insbesondere unabhängig von der Anzahl an Komponenten im Netzwerk, was den Einsatz in sehr großen Netzen ermöglicht.
Neben der Fehlertoleranz sind die Hardware-Kosten sowie die Energieeffizienz von NoCs von großer Bedeutung. Einen entscheidenden Einfluss auf diese Aspekte hat die verwendete Breite der Verbindungen des NoCs. Insbesondere bei Deflection Routing basierten NoCs führt eine Über- bzw. Unterdimensionierung der Breite der Verbindungen zu unnötig hohen Hardware-Kosten bzw. schlechter Performanz. Im zweiten Teil dieser Arbeit wird die optimale Breite der Verbindungen eines Deflection Routing basierten NoCs untersucht. Außerdem wird ein Verfahren zur Reduzierung der Breite dieser Verbindungen vorgestellt. Simulations- und Synthese-Ergebnisse zeigen, dass dieses Verfahren eine erhebliche Reduzierung der Hardware-Kosten bei ähnlicher Performanz ermöglicht.
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Role of social network properties on the impact of direct contact epidemicsBadham, Jennifer Marette, Information Technology & Electrical Engineering, Australian Defence Force Academy, UNSW January 2008 (has links)
Epidemiological models are used to inform health policy on issues such as target vaccination levels, comparing quarantine options and estimating the eventual size of an epidemic. Models that incorporate some elements of the social network structure are used for diseases where close contact is required for transmission. The motivation of this research is to extend epidemic models to include the relationship with a broader set of relevant real world network properties. The impact of degree distribution by itself is reasonably well understood, but studies with assortativity or clustering are limited and none examine their interaction. To evaluate the impact of these properties, I simulate epidemics on networks with a range of property values. However, a suitable algorithm to generate the networks is not available in the literature. There are thus two research aspects: generating networks with relevant properties, and estimating the impact of social network structure on epidemic behaviour. Firstly, I introduce a flexible network generation algorithm that can independently control degree distribution, clustering coefficient and degree assortativity. Results show that the algorithm is able to generate networks with properties that are close to those targeted. Secondly, I fit models that account for the relationship between network properties and epidemic behaviour. Using results from a large number of epidemic simulations over networks with a range of properties, regression models are fitted to estimate the separate and joint effect of the identified social network properties on the probability of an epidemic occurring and the basic reproduction ratio. The latter is a key epidemic parameter that represents the number of people infected by a typical initial infected person in a population. Results show that social network properties have a significant influence on epidemic behaviour within the property space investigated. Ignoring the differences between social networks can lead to substantial errors when estimating the basic reproduction ratio from an epidemic and then applying the estimate to a different social network. In turn, these errors could lead to failure in public health programs that rely on such estimates.
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