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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.
51

A Distributed and Heuristic Policy-based Management Architecture for Large-Scale Grids

Magaña Perdomo, Edgar 30 May 2008 (has links)
The aim of this thesis is to design and implement a new Grid Resource Management methodology, where non-massive resources owners would be able to share their resources and integrate human collaboration across multiple domains regardless of network technology, operative platform or administrative domain.This thesis proposes a distributed and heuristic policy-based resource management architecture for large-scale Grids. The resource management architecture proposed herein is composed of four main building blocs: services management, resource discovery and monitoring, resource scheduling and jobs allocation and activation. The Grid Services Management (GSM) and Jobs Allocation and Activation (JAA) are supported by means of a Policy-based Grid Resource Management Architecture (PbGRMA). This architecture is able to identify service needs arising from diverse sources during the deployment and management of Grid Services, such as requirements demanded by customers, applications and network conditions. Afterwards, the PbGRMA merges these requirements into deployment policies for the corresponding Grid Services. The Grid Resource Discovery and Monitoring (GRDM) is supported by the introduction of the SNMP-based Balanced Load Monitoring Agents for Resource Scheduling (SBLOMARS), in which network and computational resources are monitored by distributed agents. This allows for a flexible, heterogeneous and scalable monitoring system. The Grid Resource Scheduling (GRS) is based on the Balanced Load Multi-Constrained Resource Scheduler (BLOMERS). This heuristic scheduler represents an alternate way of solving the inherent NP-hard problem for resource scheduling in large-scale distributed networks by means of the implementation of a Genetic Algorithm.Finally, based on the outcome of both the GRDM and GRS, the PbGRMA allocates the corresponding Grid Services by means of its interfaces with Globus ToolKit Middleware and Unix-based CLI commands along of any large-scale Grid Infrastructure. The synergy obtained by these components allows Grid administrators to exploit the available resources with predetermined levels of Quality of Service (QoS), reducing computational costs and makespan in resource scheduling while ensuring that the resource load is balanced throughout the Grid. The makespan of a schedule is the time required for all jobs to be processed when no one job could be interrupted during its execution and each node can perform at most one operation at any time.This new approach has been successfully tested in a real large-scale scenario such as Grid5000. The results presented along this Thesis show that our general solution is a reliable, flexible and scalable architecture to deploy and manage Grid Services in large-scale Grid Infrastructures. Moreover, the substitution of the heuristic algorithm approach used into the Grid Resource Scheduling (GRS) phase by other non-heuristics selection algorithms could make our solution useful in smaller Grid Infrastructures.
52

Border Gateway Protocol : Implementationer på stubnätverk

Karlsson, Jimmy January 2010 (has links)
<p>Arbetet tar upp BGP-multihoming för mindre organisationer. Den jämför ett kommersiell alternativ mot open source-alternativ. Detta är för att se vad som krävs en av open source-lösning för ge konkurrens på routermarknaden, samt besparingar för organisationer som ska använda denna lösning.Praktiska och teoretiska jämförelser görs där Cisco-lösningar jämförs med OpenBGPD. Datan utifrån dessa tester används för att svara på problemfrågan. Sammanfattningsvis har open source produkter en fördel hårdvarumässigt på grund av lägre kostnader medan kommersiella har stora fördelar då de förlitar sig på nyare standarder.</p>
53

Implementering av 802.1x i trådbundna datanätverk / Implementation of 802.1x in wired computer networks

Forsman, Gustaf, Hult, Daniel January 2008 (has links)
<p>I dagsläget ligger oftast fokus för datasäkerhet hos de flesta företag och organisationer på att skydda gränsen mellan det egna interna datanätverket och det yttre publika. Detta kan leda till att skyddet på insidan försummas och öppna upp möjligheter för olika typer av obehörig användning.</p><p>Företag X har ett stort datanätverk med behov av skydd på insidan. Detta beror på att fysisk tillgång till nätverket är svår att begränsa på grund av att det till största del är placerat i öppna miljöer. Detta examensarbete behandlar en implementation av standarden 802.1x hos detta företag. 802.1x gör det möjligt att begränsa användandet av datanätverket baserat på vilka premisser ändutrustningen verifierar sig med. Åtkomst till nätverket sätts redan på den fysiska porten i nätverket där utrustningen kopplas in.</p><p>Kraven och önskemålen från företaget har varit att ta fram och genomföra test av en lösning som innehåller verifieringsmetoder för olika typer av ändutrustning. Kraven har inkluderat metoder för att verifiera ordinarie användare, besökare och övrig utrustning. Dessutom fanns krav på att lösningen inte skulle påverka nuvarande produktionssystem nämnvärt samt vara redundant för att garantera kontinuerlig tillgänglighet.</p><p>För att ta fram denna lösning utfördes laborationer i en miljö som motsvarar företagets produktionsmiljö. Lösningen som togs fram bygger i månt och mycket på befintliga komponenter i företagets datasystem. En radiusserver tar emot inloggningsförfrågningar från ändutrustning och verifierar mot katalogtjänsten. För att passa in i nuvarande system har FreeRADIUS använts för detta ändamål då funktionalitet finns för samarbete gentemot företagets befintliga katalogtjänst som är Novell eDirectory. Olika sorters användare och ändutrustning får sedan tillgång till rätt resurser dynamiskt beroende på deras förutbestämda rättigheter.</p> / <p>In today’s computer networks, the companies and organisations concerns of security mostly are about protecting the border between the internal and external networks. This can lead to neglecting the inside protection which creates opportunities for unauthorized usage of the companies resources.</p><p>The company that this thesis discusses have a large computer network with protection needed on the inside as physical access to the network is hard to limit due to open environments. This thesis focuses on an implementation of the 802.1x standard at the above mentioned company. 802.1x make it possible to limit usage of the computer network based on the credentials delivered from the connected devices. The devices get validated on the physical port that they connect to the network through.</p><p>The company requested a solution which included methods for authentication of different kinds of users and equipment. This could be regular users, visitors and other devices. Part from that there were demands of a minimal influence on the existing environment and redundancy to guarantee highest possible availability.</p><p>To reach the solution, a test setup was implemented in an environment corresponding to the company’s production system. The final solution was mainly built on components already existing at company’s site. Authentication requests made by users or devices are passed to a radius server which in turn asks the directory service for authentication validation. FreeRADIUS have been the solution of choice for this as it fits the requirements to cooperate with the company’s already existing Novell eDirectory. The end users and devices then dynamically get access to appropriate resources based on their assigned rights.</p>
54

Netzentwicklung im CSN / Network development at CSN

Schade, Markus 10 September 2004 (has links) (PDF)
Das Chemnitzer StudentenNetz (CSN) verwaltet ein mittelgroßes Netzwerk in den Wohnheimen des Studentenwerkes Chemnitz-Zwickau. Mitarbeitern und Interessenten erhalten einen Überblick und Einblick in die vorhandene Netzstruktur und die Konfiguration der verwendeten Technik. Es wird auch auf mögliche Szenarien für zukünftige Entwicklungen eingegangen.
55

Klassenbasierter Anschluss im Chemnitzer Studenten Netz

Junge, Sebastian 10 December 2005 (has links) (PDF)
Im Rahmen dieser Studienarbeit soll die Bedeutung klassenbasierter Anschlüsse im Chemnitzer Studenten Netz untersucht und Tools bereitgestellt werden, welche eine weitgehend automatisierte Anlage/Verwaltung solcher Netzklassen ermöglichen.
56

Mobilaus duomenų perdavimo (GPRS) ir vietinių belaidžių tinklų (WLAN) integracijos ir sąveikos tyrimas / Analysis of integration and interoperability of GPRS and WLAN networks

Baubinas, Tomas 25 June 2005 (has links)
Nowadays the popularity of WLANs is growing very rapidly. The basic solution for the connection of WLAN users to the global internet network is using leased lines or the other standard data transmission networks. But there may occur situations, when the only network for the data transmission we can use for the connection to the internet, is GSM network. In such a case, we are proposing to connect the users of WAN/WLAN networks by using GSM network, which has complete coverage in the territory of Lithuania. To guarantee the sufficient data transfer rate, we use bonding of several parallel GPRS/EDGE/UMTS channels into one total channel. In such a way we increase the reliability and data transfer rate of the total mobile data transmission channel. The parallel channels are bonded into one total channel by using either the hardware (Cisco) routers, or the software routers, configured using network administration tools of Linux operating system. In this work we give all the tools and configuration settings necessary for the realization of such a system. The results of QoS characteristics measurements are given too. We measure packet delay and data transfer rate. The majority of measurements are made by using several parallel GPRS channels because of wide spread GPRS technologies. The key accent of the system is free selection of the physical layer (OSI model) of the parallel channel. So we can bond either several GPRS, or EDGE, or UMTS channels.
57

THE EFFECT OF THE INVASIVE MACROINVERTEBRATE, BYTHOTREPHES LONGIMANUS, ON THE GROWTH OF CISCO (COREGONUS ARTEDII) IN ONTARIO SHIELD LAKES

James, LEAH 20 July 2010 (has links)
Bythotrephes longimanus is an invasive, macroinvertebrate from Eurasia that was introduced into the Great Lakes region in the mid 1980s. Bythotrephes introductions into lake ecosystems have resulted in substantial changes in zooplankton communities, including declines in species richness, abundance, biomass and production. Changes in zooplankton communities may alter the quantity and quality of prey to other predators such as cisco (Coregonus artedii), a pelagic forage fish. Here, I conduct a current day comparison of cisco populations to determine if prey consumption by cisco differs in the presence of Bythotrephes, and whether changes in diet result in energetic consequences (changes in growth and condition) for cisco. Effects of Bythotrephes on native zooplankton communities have resulted in substantial changes in the variety and proportion biomass of zooplankton and macroinvertebrate prey types in cisco stomachs, which have in turn modified growth of cisco. Cisco taken from invaded lakes achieve greater total lengths but changes in condition were not detected. This effect may be driven by improved growth in the second and subsequent growing seasons, suggesting that growth consequences for young fish (that do not feed on Bythotrephes) are different than for older individuals. Length-at-structure age data indicate that by the end of the first growing season (age 1) cisco achieve comparable total body lengths in invaded and reference lakes, suggesting that food consumption by young cisco remains unchanged by Bythotrephes. Alternatively, young cisco forage may be reduced in the presence of Bythotrephes, resulting in decreased survival and similar growth among individuals that survive to age 1. In contrast, despite changes in the zooplankton community; growth of older fish (≥ age 2) was enhanced in lakes that have Bythotrephes. Improved growth among older cisco (≥ age 2) in invaded lakes may be related to the presence of a newly attainable, high energy prey source (Bythotrephes). Alternatively, enhanced growth may be explained by lower competition due to reduced recruitment of young cisco (≤ age 1) in invaded lakes. Increased knowledge regarding the effects of Bythotrephes on growth of cisco is important in furthering our understanding of its impact on lake ecosystems. / Thesis (Master, Biology) -- Queen's University, 2010-04-28 22:46:07.756
58

Effective Approaches to the Care of the Employees on Parental Leave

Maleček, Jiří January 2014 (has links)
This thesis deals with mapping and reengineering of existing wifi network. The goal is an analysis of the measured characteristics with the program Ekahau Site Survey. On its basis is designed new solution. Own work is also an financial assessment of the solution.
59

Performance evaluation of a network infrastructure monitored with SNMP polls and traps / Utvärdering av prestanda för en nätverksinfrastruktur övervakad med SNMP polls och traps

Ek, Christian, Norling, Edvin January 2011 (has links)
The result of this bachelor thesis is a comparison between three different network devices on how many resources that is used on them when utilizing SNMPv1 and SNMPv2c polls and traps. The devices tested are an old Cisco router, a modern Juniper gateway and a Linux server. The experiments conducted prove that SNMP does not utilize the network devices resources to a point that it becomes an issue for the performance. These tests are done to ensure that SNMP do not use up to many resources on the infrastructure which would decrease the functionality and performance of the network. This study shows whether or not SNMP monitoring is a problem for the enterprise network / Resultatet utav detta kandidatexamensarbete är en jämförelse mellan tre olika nätverksenheter och hur mycket prestanda som utnyttjas när SNMPv1 och SNMPv2c poll och trap används på enheterna. Enheterna som testerna utförs på är en gammal Cisco router, en modern Juniper gateway och en Linux server. Testerna visar att SNMP inte använder såpass mycket utav enheternas resurser att det påverkar prestandan på dessa enheter. Dessa tester görs för att försäkra oss om att SNMP inte tar upp så mycket prestanda på näverksenheterna att funktionaliteten och prestandan minskar. Detta kandidatexamensarbete visar huruvida SNMP övervakning är ett problem för nätverksenheter eller inte.
60

Border Gateway Protocol : Implementationer på stubnätverk

Karlsson, Jimmy January 2010 (has links)
Arbetet tar upp BGP-multihoming för mindre organisationer. Den jämför ett kommersiell alternativ mot open source-alternativ. Detta är för att se vad som krävs en av open source-lösning för ge konkurrens på routermarknaden, samt besparingar för organisationer som ska använda denna lösning.Praktiska och teoretiska jämförelser görs där Cisco-lösningar jämförs med OpenBGPD. Datan utifrån dessa tester används för att svara på problemfrågan. Sammanfattningsvis har open source produkter en fördel hårdvarumässigt på grund av lägre kostnader medan kommersiella har stora fördelar då de förlitar sig på nyare standarder.

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