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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.
1

A network aware adaptable application using a novel content scheduling and delivery scheme

Abdul Rahman, Abdul Muin January 2006 (has links)
The aim of this research is to investigate techniques or methodologies that will allow networked applications to adapt to network conditions between end nodes in order to maintain a reasonable Quality of Service and to design, develop and test techniques for achieving such adaptability through the use of a novel content scheduling and delivery scheme. In order to achieve this adaptation, information regarding network conditions, both static and dynamic, has to be first gathered. Since various parties have already conducted substantial research in this area, the task was to review those network measurement techniques and adopt a suitable one for use in the subsequent research. Hence the research is concerned more on how to realize these techniques in practical terms and make those network parameters accessible to applications that are going to adapt based on them. A network measurement service utilizing a standard measurement tool was proposed, developed, tested and subsequently used throughout the project. In this way the research project implementation has help in trying to understand the impact of network measurement on the overall performance of the system and what network metrics are essential in order to help the application make better adaptation decision. The project proceeded further to develop and show case an adaptable network application using a novel scheme in which content was restructured and its delivery rescheduled taking account of the available bandwidth, the content structure, size and order of importance and user specified deadlines, which made use of the network measurement service. In so doing, the project sought to show how and when adaptation can be applied and its potential benefits or otherwise as compared to conventional applications based on best effort systems. The project has proved that by adapting according to the abovementioned scheme in the event of poor network performance, user specified deadlines can be satisfied by reducing the load with contents of high importance being delivered first while contents of less importance being delivered during idle time or user's reading time or ignored if the deadline could not be met. In most cases content of high importance are delivered faster in the adaptable system as compared to the conventional best effort system.
2

Network Applications and the Utah Homeless Network

Snyder, Michael A. 01 May 2014 (has links)
Graph theory is the foundation on which social network analysis (SNA) is built. With the flood of "big data," graph theoretical concepts and their linear algebraic counterparts are essential tools for analysis in the burgeoning field of network data analysis, in which SNA is a subset. Here we begin with an overview of SNA. We then discuss the common descriptive measures taken on network data as well as proposing new measures specific to homeless networks. We also define a new data structure which we call the location sequence matrix. This data structure makes certain computational network analyses particularly easy. Finally we apply Pulse Processes in a new way to the homeless network in Utah. We believe the new data structure and pulse processes, when used for analysis of the Utah homeless services. In particular, pulse processes, first introduced by Brown, Roberts, and Spencer, to analyze energy demand, form a dynamic population model that can provide a measure of the stability in a network and the patterns of action of individuals experiencing homelessness.
3

Peer-to-Peer File Transfer in Wireless Mesh Networks

ElRakabawy, Sherif M., Lindemann, Christoph 17 December 2018 (has links)
In this paper, we consider the peer-to-peer transfer of popular files between devices in a wireless mesh network. We address the problem that occurs when multiple nodes try to access the same file simultaneously, resulting in increased contention on the shared wireless channel. To counteract this problem, we propose a cooperative file transfer protocol which splits a file into fixed-sized pieces and allows simultaneous downloads of such pieces from multiple peers. Opposed to previous approaches, the proposed protocol selects the potential download peers such that the corresponding download paths possess minimum interference among each other. In a performance study where we compare our approach with other download schemes proposed in the literature, we show that our cooperative protocol roughly halves the time required for downloading a file.
4

AETOS: An Architecture for Offloading Core LTE Traffic Using Software Defined Networking Concepts

Nasim, Kamraan January 2016 (has links)
It goes without saying that cellular users of today have an insatiable appetite for bandwidth and data. Data-intensive applications, such as video on demand, online gaming and video conferencing, have gained prominence. This, coupled with recent innovations in the mobile network such as LTE/4G, poses a unique challenge to network operators in how to extract the most value from their deployments all the while reducing their Total Cost of Operations(TCO). To this end, a number of enhancements have been proposed to the ”conventional” LTE mobile network. Most of these recognize the monolithic and non-elastic nature of the mobile backend and propose complimenting core functionality with concepts borrowed from Software Defined Networking (SDN). In this thesis we shall attempt to explore some existing options within the LTE standard to mitigate large traffic churns. We will then review some SDN-enabled alternatives, and attempt to derive a proof based critique on their merits and drawbacks.
5

Saving Energy in Network Hosts With an Application Layer Proxy: Design and Evaluation of New Methods That Utilize Improved Bloom Filters

Jimeno, Miguel 11 December 2009 (has links)
One of the most urgent challenges of the 21st century is to investigate new technologies that can enable a transition towards a society with a reduced CO2 footprint. Information Technology generates about 2% of the global CO2, which is comparable to the aviation industry. Being connected to the Internet requires active participation in responding to protocol messages. Billions of dollars worth of electricity every year are used to keep network hosts fully powered-on at all times only for the purpose of maintaining network presence. Most network hosts are idle most of the time, thus presenting a huge opportunity for energy savings and reduced CO2 emissions. Proxying has been previously explored as a means for allowing idle hosts to sleep yet still maintain network presence. This dissertation develops general requirements for proxying and is the first exploration of application-level proxying. Proxying for TCP connections, SIP, and Gnutella P2P was investigated. The TCP proxy keeps TCP connections open (when a host is sleeping) and buffers and/or discards packets as appropriate. The SIP proxy handles all communication with the SIP server and wakes up a sleeping SIP phone on an incoming call. The P2P proxy enables a Gnutella leaf node to sleep when not actively uploading or downloading files by handling all query messages and keyword lookups in a list of shared files. All proxies were prototyped and experimentally evaluated. Proxying for P2P lead to the exploration of space and time efficient data structures to reduce the computational requirements of keyword search in the proxy. The use of pre-computation and hierarchical structures for reducing the false positive rate of a Bloom filter was explored. A Best-of-N Bloom filter was developed, which was shown to have a lower false positive rate than a standard Bloom filter and the Power-of-2 Bloom filter. An analysis of the Best-of-N Bloom Filter was completed using Order Statistics to predict the false positive rate. Potential energy savings are shown to be in the hundreds of millions of dollars per year assuming a modest adoption rate of the methods investigated in this dissertation. Future directions could lead to greater savings.
6

Platforma pro rychlý vývoj síťových zařízení / Platform for Rapid Development of Network Devices

Tobola, Jiří January 2007 (has links)
This thesis deals with the design and implementation of an FPGA-based platform for rapid development of network applications for the COMBO cards family. The proposed platform includes a generic data transfer protocol - FrameLink, a set of tools for FrameLink manipulation, network interface blocks for 1 Gigabit Ethernet, high-speed connection to the software layer via PCI, PCI-X or PCI Express bus and a set of IP cores for network traffic analysis and processing. The benefits of the proposed platform are demonstrated on design and implementation of a network interface card, hardware firewall and exporter of unified packet headers.
7

A Sensor Network System for Monitoring Short-Term Construction Work Zones

Bathula, Manohar January 2008 (has links)
No description available.
8

Small area, low power, mixed-mode circuits for hybrid neural network applications

Fang, Xuefeng January 1994 (has links)
No description available.
9

Approche générative conjointe logicielle-matérielle au développement du support protocolaire d’applications réseaux / A generative codesign software-hardware based approach for building efficient network protocol parsers for embedded systems

Solanki, Jigar 27 November 2014 (has links)
Les communications entre les applications réseaux sont régies par un ensemble de règles regroupées sous forme de protocoles. Les messages protocolaires sont gérés par une couche de l’application réseau connue comme étant la couche de support protocolaire. Cette couche peut être de nature logicielle, matérielle ou conjointe. Cette couche se trouve à la frontière entre le coeur de l’application et le monde extérieur. A ce titre, elle représente un composant névralgique de l’application. Les performances globales de l’application sont ainsi directement liées aux performances de la couche de support protocolaire associée.Le processus de développement de ces couches consiste à traduire une spécification du protocole, écrite dans un langage de haut niveau tel que ABNF dans un langage bas niveau, logiciel ou matériel. Avec l’avènement des systèmes embarqués, de plus en plus de systèmes sur puce proposent l’utilisation de ressources matérielles afin d’accroître les performances des applicatifs. Néanmoins, peu de processus de développement de couches de support protocolaire tirent parti de ces ressources, en raison notamment de l’expertise nécessaire dans ce domaine.Cette thèse propose une approche générative conjointe logicielle-matérielle au développement du support protocolaire d’applications réseaux, pour améliorer leur performance tout en restant ergonomique pour le développeur de l’application. Notre approche est basée sur l’exploitation d’un langage dédié, appellé Zebra pour générer les différents composants logiciels et matériels formant la couche de support. L’expertise nécessaire est déportée dans l’utilisation du langage Zebra et les composants matériels générés permettent d’accroître les performances de l’application.Les contributions de cette thèse sont les suivantes : Nous avons effectué une analyse des protocoles et applications réseaux. Cette analyse nous a permis d’identifier les composants pour lesquels il est possible d’obtenir des gains de performances.Nous avons conçu et exploité un langage dédié, Zebra, permettant de décrire les différentes entités de la couche de support protocolaire et générant les éléments logiciels et matériels la composant. Nous avons construit un système sur puce exécutant un système d’exploitation Linux afin d’étayer notre approche. Nous avons conçu des accélérateurs matériels déployables pour différents protocoles réseaux sur ce système et pilotables par les applicatifs. Afin de rendre l’accès aux accélérateurs matériels transparent pour les applications réseaux, nous avons développé un intergiciel gérant l’ensemble de ces accès. Cet intergiciel permet à plusieurs applications et/ou à plusieurs clients d’une même application d’utiliser les accélérateurs pour le traitement des messages protocolaires. Nous avons évalué les performances de notre approche dans des conditions réelles. Nous avons comparé ces performances à celles de couches de supports faisant référence dans le domaine. Nous avons constaté un gain de performance conséquent pour l’approche que nous proposons. / Communications between network applications is achieved by using rulesets known as protocols. Protocol messages are managed by the application layer known as the protocol parsing layer or protocol handling layer. Protocol parsers are coded in software, in hardware or based on a co-design approach. They represent the interface between the application logic and the outside world. Thus, they are critical components of network applications. Global performances of network applications are directly linked to the performances of their protocol parser layers.Developping protocol parsers consists of translating protocol specifications, written in a high level language such as ABNF towards low level software or hardware code. As the use of embedded systems is growing, hardware ressources become more and more available to applications on systems on chip (SoC). Nonetheless, developping a network application that uses hardware ressources is challenging, requiring not only expertise in hardware design, but also a knowledge of the protocols involved and an understanding of low-level network programming.This thesis proposes a generative hardware-software co-design based approach to the developpement of network protocol message parsers, to improve their performances without increasing the expertise the developper may need. Our approach is based on a dedicated language, called Zebra, that generates both hardware and software elements that compose protocol parsers. The necessary expertise is deported in the use of the Zebra language and the generated hardware components permit to improve global performances.The contributions of this thesis are as follows : We provide an analysis of network protocols and applications. This analysis allows us to detect the elements which performances can be improved using hardware ressources. We present the domain specific language Zebra to describe protocol handling layers. Software and hardware components are then generated according to Zebra specifications. We have built a SoC running a Linux operating system to assess our approach.We have designed hardware accelerators for different network protocols that are deployed and driven by applications. To increase sharing of parsing units between several tasks, we have developped a middleware that seamlessly manages all the accesses to the hardware components. The Zebra middleware allows several clients to access the ressources of a hardware accelerator. We have conducted several set of experiments in real conditions. We have compared the performances of our approach with the performances of well-knownprotocol handling layers. We observe that protocol handling layers baded on our approach are more efficient that existing approaches.
10

Návrh síťových aplikací na platformě NetCOPE / Design of Network Applications for a NetCOPE Platform

Hank, Andrej January 2009 (has links)
Monitoring and security in multigigabit networks with speeds 1 - 100 Gb/s needs hardware acceleration. NetCOPE platform for rapid development of network applications uses hardware acceleration card with FPGA technology by means of hardware/software codesign. Increas in performance of platform's software part is dependent of parallel processing in applications to take advantage of utilising more processor cores. This thesis analyses NetCOPE platform architecture and possibilities of parallelising classic network applications and creates models of concurrent access to data in NetCOPE platform to utilize more processor cores. These models are subsequently implemented as extensions to platform's Linux system drivers. Userspace libraries are created to provide simple interface for applications to use these new features. To achieve high throughput of this solution several optimizations are performed. Results are measured by created testing tools.

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