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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.
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Showing 401 to 410 of 492 (0.224 seconds)| 401 |
Low Overhead Ethernet Communication for Open MPI on Linux ClustersHoefler, Torsten, Reinhardt, Mirko, Mietke, Frank, Mehlan, Torsten, Rehm, Wolfgang 20 July 2006 (has links)
This paper describes the basic concepts of our solution to
improve the performance of Ethernet Communication on a Linux Cluster
environment by introducing Reliable Low Latency Ethernet Sockets. We
show that about 25% of the socket latency can be saved by using our
simplified protocol. Especially, we put emphasis on demonstrating that
this performance benefit is able to speed up the MPI level
communication. Therefore we have developed a new BTL component for Open
MPI, an open source MPI-2 implementation which offers with its Modular
Component Architecture a nearly ideal environment to implement our
changes. Microbenchmarks of MPI collective and Point-to-Point operations
were performed. We see a performance improvement of 8% to 16% for LU and
SP implementations of the NAS parallel benchmark suite which spends a
significant amount of time in the MPI. Practical application tests with
Abinit, an electronic structure calculation program, show that the
runtime of be nearly halved on a 4 node system. Thus we show evidence
that our new Ethernet communication protocol is able to increase the
speedup of parallel applications considerably.
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Consistent Automation Solutions for Electrohydraulic Drives in Times of Industry 4.0Köckemann, Albert, Birke, Benno January 2016 (has links)
Electrohydraulic drives are primarily used whenever a low power/weight ratio, a compact build and/or large forces are required for individual applications. These drives are often used together with electric drive technology in machines. However, in terms of automation, unlike electric drives, electrohydraulic drives are still largely connected via analog interfaces and centralized closed control loops today. To compensate for this competitive disadvantage of hydraulic drive technology and, at the same time, significantly enhance its performance and diagnostics capability, a consistent automation solution has been developed that can be configured for both centralized and decentralized solutions. This contribution firstly gives an overview over this complete solution already available and its classification in the automation world. In a second step, the subset of decentralized drive solutions contained therein is presented in more detail and their benefits are explained on the basis of some exemplary applications.
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Migration to P4-Programmable Switches and Implementation of the Rapid Spanning Tree Protocol / Övergång till P4-Programmerbara Switchar och Implementation av Rapid Spanning Tree ProtocolLindström, Henrik January 2020 (has links)
P4 is a high-level language for programming the data plane of a network switch. These P4-programmable switches come with no pre-defined behavior or protocols, so it is entirely up to the loaded P4 program to define these. This allows the user to exclude any unwanted functionality and to create custom protocols. It also removes the dependence on the switch vendor in terms of both trust and addition of new features. This thesis looks at migration from traditional switches to P4-programmable ones. Since no behavior is included out-of-the-box in the P4 switches, a search is made for open-source P4 projects and the functionality they provide is evaluated. It is found that most link layer functionality can be achieved with them, with the exception being loop prevention by spanning tree protocols. Therefore, one of the projects is extended with an implementation of the Rapid Spanning Tree Protocol based on the IEEE 802.1D-2004 standard. Finally, partial migration of networks to P4 switches and to the Software Defined Networking (SDN) paradigm is studied based on a literature review. Four general approaches and specific architectures for these are found, and it is concluded that such a hybrid network can still benefit from P4 and having a centralized SDN controller.
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Evaluación y diagnóstico en la red de comunicación de datos de un hospital de nivel III-2 para dar la propuesta de una nueva redAlarcón Vega, Adolfo Martín 13 August 2021 (has links)
Este trabajo de tesis se realizó como parte del convenio de colaboración, Intercambio y
unión de capacidades entre el Hospital Cayetano Heredia/HNCH-MINSA y la Pontificia
Universidad Católica del Perú, con el objetivo de mejorar la infraestructura de la red de
comunicaciones en el Hospital Cayetano Heredia, para lograrlo se hizo un estudio del flujo
de información existente entre las oficinas y también se hizo un estudio de la
infraestructura del cableado de comunicaciones y los equipos instalados, determinándose
luego que se debería diseñar una nueva red, para tal efecto luego de un estudio de las
distintas soluciones de cableado par trenzado UTP existentes en el mercado, se eligió la
tecnología Gigabit Ethernet para propuesta del diseño final.
Se realizaron inspecciones a las distintas oficinas, consultorios y ambientes donde se ha
tendido el cableado estructurado por dentro y por fuera del Hospital Cayetano Heredia,
para documentar el estado de sus instalaciones. Con el objetivo de realizar mediciones del
uso del ancho de banda, se procedió a instalar el equipo LANMETER 860 de la marca
Fluke y el software Network Inspector, ambas herramientas permitieron obtener valores
estadísticos de parámetros tales como: la difusión (broadcast), colisiones, tasa de errores,
etc. de los principales conmutadores instalados de 10/100 Mbps, estos resultados fueron
útiles para saber como era la tasa de uso de la red y elaborar los requerimientos reales
para el diseño de la red de datos.
Además de dimensionar el sistema de red, se escogió una solución para el despliegue del
cableado UTP de manera flexible, práctica y adecuada a la infraestructura del edificio.
También se brindan los criterios y cálculos necesarios para la realización de un enlace
inalámbrico con línea de vista, entre aquellos edificios que requieren comunicación que por
su lejanía, no se encuentran integrados a la red. Los equipos y el cableado a ser
considerados para el diseño, se eligieron después de hacer una comparación de marcas
ofrecidas en el mercado de las telecomunicaciones, basándose en el análisis comparativo
del desempeño, como también observando el aspecto económico.
Finalmente se ha realizado una descripción económica de costos para su implementación,
añadiendo a éste un cronograma de actividades que contemplaría los tiempos y los
recursos que demandaría la futura red.
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Diseño de una red de transporte de datos multidepartamental carrier ethernet con protección en anillo G.8032Velásquez Centeno, Leslie Rossana 13 March 2017 (has links)
El presente proyecto de tesis consiste en el diseño de una red de transporte de datos
multidepartamental en el Perú, con el objetivo de ofrecer servicios Carrier Ethernet con
protección a nivel de capa 2 según el modelo OSI. El mecanismo de protección
propuesto es G.8032 y la red permitirá otorgar perfiles de QoS a los servicios de los
clientes.
El primer capítulo ofrece una visión general de la evolución de las redes de transmisión
de datos del Perú, así como una breve presentación del actual despliegue del proyecto
de Red Dorsal Nacional de Fibra Óptica. Además se muestra un enfoque de la
importancia de la tecnología Ethernet en la actualidad.
El segundo capítulo presenta el marco teórico de la arquitectura de una red Carrier
Ethernet, así como el mecanismo de protección para topologías en anillo G.8032, con
sus principales características y funcionalidades.
El tercer capítulo analiza la evolución de la demanda de tráfico datos hasta la
actualidad y realiza una proyección a 6 años de dicha demanda.
El cuarto capítulo describe el diseño de los anillos lógicos correspondientes al
mecanismo de protección G.8032, el diseño global de la red y una breve descripción de
los equipos a usar y sus funcionalidades.
El quinto capítulo detalla el cálculo del OPEX y el CAPEX de la red, así como los
ingresos recurrentes por los servicios dedicados prestados a las empresas u
operadoras de telecomunicaciones.
Por último, se presentan las conclusiones y recomendaciones del presente trabajo, que
permitirán consolidar y/o mejorar la solución desarrollada en la presente tesis.
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Low-Latency Hard Real-Time Communication over Switched Ethernet / Effiziente Echtzeitkommunikation über Switched EthernetLöser, Jork 01 January 2006 (has links) (PDF)
With the upsurge in the demand for high-bandwidth networked real-time applications in cost-sensitive environments, a key issue is to take advantage of developments of commodity components that offer a multiple of the throughput of classical real-time solutions. It was the starting hypothesis of this dissertation that with fine grained traffic shaping as the only means of node cooperation, it should be possible to achieve lower guaranteed delays and higher bandwidth utilization than with traditional approaches, even though Switched Ethernet does not support policing in the switches as other network architectures do. This thesis presents the application of traffic shaping to Switched Ethernet and validates the hypothesis. It shows, both theoretically and practically, how commodity Switched Ethernet technology can be used for low-latency hard real-time communication, and what operating-system support is needed for an efficient implementation.
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Low-Latency Hard Real-Time Communication over Switched EthernetLöser, Jork 31 January 2006 (has links)
With the upsurge in the demand for high-bandwidth networked real-time applications in cost-sensitive environments, a key issue is to take advantage of developments of commodity components that offer a multiple of the throughput of classical real-time solutions. It was the starting hypothesis of this dissertation that with fine grained traffic shaping as the only means of node cooperation, it should be possible to achieve lower guaranteed delays and higher bandwidth utilization than with traditional approaches, even though Switched Ethernet does not support policing in the switches as other network architectures do. This thesis presents the application of traffic shaping to Switched Ethernet and validates the hypothesis. It shows, both theoretically and practically, how commodity Switched Ethernet technology can be used for low-latency hard real-time communication, and what operating-system support is needed for an efficient implementation.
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Web server pro vestavěné aplikace / Web Server for Embedded ApplicationsPirkl, Tomáš January 2007 (has links)
This work discuses Embedded Ethernet systems. Embedded Webserver Platform is designed. This design embrace microkontroler, Ethernet driver, and external SRAM. It includes implementation on PCB with MMC interface and software implementation of MMC driver and FAT file system. Reference model ISO/OSI, reference model TCP/IP, Ethernet and UDP, TCP, IP, HTTP protocol is presented.
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Entwicklung des Kommunikationsteilsystems für ein objektorientiertes, verteiltes Betriebssystem09 November 1998 (has links)
Thema dieser Arbeit ist die Entwicklung eines Kommunikationsteilsystems fuer
das Experimentiersystem CHEOPS zur Ermoeglichung einer Interobjektkommunika-
tion zwischen Objekten auf dem gleichen bzw. verschiedenen Systemen.
Ausgangspunkte stellen dabei eine verfuegbare Implementation eines Ethernet-
Treibers der Kartenfamilie WD80x3 fuer MS-DOS, eine geforderte Kommunikations-
moeglichkeit mit UNIX-Prozessen sowie die dort benutzbaren Protokoll-Familien
dar.
Die Arbeit beschaeftigt sich mit der Analyse und Konzipierung des Ethernet-
Treibers sowie der Internet-Protokoll-Familie fuer CHEOPS als auch deren
Implementation resultierend in einem minimalen Grundsystem. Weiterhin wird
ein erster Entwurf fuer ein spaeter weiterzuentwickelndes bzw. zu vervoll-
staendigendes Netz-Interface vorgeschlagen und durch eine Beispiel-Implemen-
tierung belegt.
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LONG TERM VEHICLE HEALTH MONITORINGCridland, Doug, Dehmelt, Chris 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 / While any vehicle that is typically part of a flight test campaign is heavily instrumented to validate its performance, long term vehicle health monitoring is performed by a significantly reduced number of sensors due to a number of issues including cost, weight and maintainability. The development and deployment of smart sensor buses has reached a time in which they can be integrated into a larger data acquisition system environment. The benefits of these types of buses include a significant reduction in the amount of wiring and overall system complexity by placing the appropriate signal conditioners close to their respective sensors and providing data back over a common bus, that also provides a single power source. The use of a smart-sensor data collection bus, such as IntelliBus™1 or IEEE-1451, along with the continued miniaturization of signal conditioning devices, leads to the interesting possibility of permanently embedding data collection capabilities within a vehicle after the initial flight test effort has completed, providing long-term health-monitoring and diagnostic functionality that is not available today. This paper will discuss the system considerations and the benefits of a smart sensor based system and how pieces can be transitioned from flight qualification to long-term vehicle health monitoring in production vehicles.
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