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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.
81

A Sensor-based System for Detecting and Registering Dump Truck Flatbed Tilts

Nguyen, Henrik, Lundborg, Mattias January 2018 (has links)
Improving the productivity in construction sites is an ongoing priority within the construction industry due to the benefits that comes with increased efficiency in construction projects where sensor technology has become a more common tool used for the pursuit of increased productivity. This project set out to implement a sensor-based system that is used on a construction site to register when a dump truck tilts its flatbed, acting as a confirmation of delivery. The work was done for a Swedish company active in the construction industry. Since construction sites provide a rough environment to operate in, a requirements specification was developed from interviews and observations done on the construction site. From the requirement specification, two prototypes were developed for testing, one with an ultrasonic sensor and one with an accelerometer. The prototypes both used an Arduino board as a controller, the Bluetooth protocol for communication between the controller and the gateway. An Android smartphone was used as the gateway. These prototypes were then tested in two phases, first in office and later mounted on a truck on the construction site. While the results from the test on the construction site were inconclusive, the results from the first test phase showed a slight advantage to the prototype implemented with the accelerometer. / Förbättrad produktivitet på byggarbetsplatser är en pågående prioritet inom byggbranschen på grund av fördelarna med ökad effektivitet i byggprojekt. Sensorbaserad teknik har blivit ett vanligare verktyg som används i sträva efter ökad produktivitet. Det här projektet hade som mål att implementera ett sensorbaserat system som skulle kunna registrera när en bygglastbil tippar sitt flak och då agera som bekräftelse på en leverans. Arbetet gjordes för ett företag som är aktivt inom byggindustrin. Eftersom att byggarbetsplatser har en tuff miljö att verka inom, så togs en kravspecifikation fram från intervjuer och observationer som utfördes på byggarbetsplatsen. Från kravspecifikationen utvecklades två prototyper för testning, en med en ultraljudssensor och en med en accelerometer. Båda prototyperna använder vardera sig av ett Arduino kort som controller, Bluetooth protokoll för kommunikation mellan controller och gateway. En Android smart telefon användes som gateway. Prototyperna testades sedan i två faser, först kontorstester, sedan monterade på en lastbil på byggarbetsplatsen. Trots att testresultaten från byggarbetsplatsen var ofullständiga, så visade testresultaten från den första testfasen en fördel för prototypen som implementerats med en accelerometer.
82

Securing BGP using blockchain technology

Tsumak, Dmitri January 2018 (has links)
The Border Gateway Protocol (BGP) is an important routing protocol used to exchangerouting information among autonomous systems on the Internet. The BGP version 4 doesnot include specific protection mechanisms against attacks or deliberate errors that couldcause disruptions of routing behavior. There were several securing solutions developedto mitigate security issues of BGP. In this thesis, current secure solutions are reviewedand evaluated against a list of security and deployment requirements. Furthermore, a newBGP securing solution is proposed which uses blockchain technology and smart contractsto exchange information required for messages validation among peers. This allows todecouple security-related data from the protocol itself and fix the problems introduced inother BGP solutions. / Border Gateway Protocol (BGP) är ett viktigt routing protokoll som används för att utbytarouting-information mellan autonoma system på Internet. BGP version 4 inkluderaringa specifika skydd mot attacker eller avsiktliga fel som kan skapa störningar i routingbeteendet. Ett flertal säkerhetslösningar har utvecklas för att förebygga säkerhetsproblemför BGP. I denna avhandling granskas nuvarande befintliga säkerhetslösningar och utvärderasmot en lista av säkerhets- och deployment-krav. Vidare presenteras en ny säkerhetslösningför BGP som använder blockchain-teknologi och smarta kontrakt för att utbytainformation som krävs för verifiering av meddelanden mellan grannar. Detta möjliggöratt frånkoppla säkerhetsrelaterad data från själva protokollet och åtgärda problemen introduceradei andra BGP lösningar.
83

Connectivity, Security and Integrationfor Cloud Manufacturing

Wang, Chen January 2017 (has links)
Det här mastersprojektet syftar till att ansluta industriroboten till moln plattformen och utvärdera anslutning och säkerhet. För att uppnå bättre anslutning, säkerhet och integration, föreslås en modifierad Moln Tillverkningssystem- (CRS) arkitektur, som kännetecknas av hög modularitet, standardisering och komposibilitet. Arkitekturens specifika applikationer iprivata, offentliga och hybridmoln diskuteras också. Sedan är en  systemarkitektur med detaljerad mjukvarukomposition designad för Molnrobotik. Enligt den föreslagna systemarkitekturen presenteras möjliga säkerhetshotskällor och motsvarande lösningar.Under projektet används Universell Robot 5 (UR5) som en praktisk robotinstans för att utveckla en kommunikationsrutin mellan KTH Moln och robotar. Ett applikationsprogramgränssnitt (API) skrivet i Python for Universell Robot och servern är etablerad. API: n består av två modulära delar, Gateway Agenten och Applikationsmjukvaran.Gateway Agenten realiserar kopplingen mellan Universell Robot 5 (UR5) och molnet, medan applikationsmjukvaran kan anpassas till specifika tillämpningar och krav. I detta projekt utvecklas tre huvudfunktioner i applikationsmjukvaran, inklusive datainsamling, datavisualisering och fjärrkontroll. Förutom att utvärdera anslutning och stabilitet simulerasdet privata robotik molnsystemet och det offentliga robotik molnsystemet med KTH Moln.Hybrid robotik moln systemet diskuteras också. Genom resultaten av fallstudier verifieras anslutningen och integrationen av Moln Tillverkningssystem. / This master thesis project aims to connect the industrial robot to the Cloud platform, and evaluate the connectivity and security. To realize better connectivity, security and integration, a modified Cloud Manufacturing System (CRS) architecture is proposed, which is characterized by high modularity, standardization and composability. The architecture’s specific applications in private, public and hybrid cloud are discussed as well. Then, one system architecture with detailed software composition is designed for Cloud Robotics.According to the proposed system architecture, possible security threat sources and corresponding solutions are presented.During the project, Universal Robot 5 (UR5) is utilized as a practical robot instance to develop a communication routine between KTH Cloud and robots. An Application Program Interface (API) written by Python for Universal Robots and the server is established. The API consists of two modularized part, Gateway Agent and Application Package. The Gateway Agent realizes the connection between the Universal Robot 5 (UR5) and the cloud, while theApplication Package can be customized according to specific application and requirements. In this project, three main functions are developed in the Application Package, including data acquisition, data visualization and remote control. Besides, to evaluate connectivity and stability, private robotics cloud system and public robotics cloud system are simulated with KTH Cloud. The hybrid robotics cloud system is discussed as well. Through the results of case studies, the connectivity and integration of Cloud Manufacturing System are verified.
84

BGPcredit : A Blockchain-based System for Securing BGP

Yang Liu, Yu January 2022 (has links)
Due to the absence of appropriate security mechanisms, even the latest version of Board Gateway Protocol (BGP) is still highly vulnerable to malicious routing hijacking. The original problem is that BGP allows router to accept any BGP update message without any extra validation process. Resource Public Key Infrastructure (RPKI) issues a series of digital signature certificates to provide binding relationship between the IP prefix in the route advertisement and the Autonomous System (AS) number on the propagation path to protect BGP routing. However, RPKI is a centralized architecture in which Certification Authority (CA) can launch power abuses attacks, such as unilaterally certificate revocation or publication repository tampering. In this thesis, we propose a blockchain-based BGP security infrastructure, named BGPcredit. The BGPcredit system synchronizes RPKI certificates by consensus process. It can maintain identical RPKI certificates repository across the whole system through blockchain, providing necessary security protection for BGP routing. In order to provide such features, we customize a proper consensus algorithm for BGPcredit which a reasonable credence management mechanism, credit computing function, block forger election process, Verifiable Random Function (VRF) are introduced. Also, the blockchain is customized to meet the system requirements. Moreover, BGPcredit advocates to make fully use of the trust of certification authorities to build a partially decentralized system. Some trusted nodes with higher authority are set to enhance the system’s security and robustness. Finally, I implement the BGPcredit prototype and conduct some validation experiments to test its performance. / På grund av avsaknaden av lämpliga säkerhetsmekanismer är även den senaste versionen av BGP fortfarande mycket sårbar för skadlig routerkappning. Det ursprungliga problemet är att BGP tillåter routern att acceptera alla BGP uppdateringsmeddelande utan någon extra valideringsprocess. RPKI utfärdar en serie digitala signaturcertifikat för att ge bindande relation mellan IP-adressprefixet i ruttannonsen och AS-numret på spridningsvägen för att skydda BGP-routningssäkerheten. Men RPKI är för centraliserad och CA kan starta strömmissbruk, till exempel ensidigt återkallande av certifikat och skadlig modifiering av publikationsregistret. I detta projekt föreslår vi en blockkedjebaserad BGP-säkerhetsinfrastruktur, kallad BGPcredit. Detta system synkroniserar RPKI-certifikat genom konsensusprocessen och kan upprätthålla identiska RPKI-certifikat arkiv över hela systemet genom blockchain, vilket ger nödvändigt säkerhetsskydd för BGP-routing. För att tillhandahålla sådana funktioner skräddarsyr vi en lämplig konsensusalgoritm baserad på nodkredit för BGPcredit som inkluderar en rimlig kredithanteringsmekanism, kreditberäkningsfunktion, blockförfalskningsprocess, VRF, etc. Dessutom har vissa anpassade ändringar i blockchain gjorts för att uppfylla systemkraven. Dessutom förespråkar BGPcredit att fullt ut utnyttja certifieringsmyndigheternas förtroende för att bygga upp ett delvis decentraliserat system. Vissa tillförlitliga noder med högre auktoritet är inställda för att förbättra systemets säkerhet och robusthet. Slutligen implementerar vi BGPcredit prototypen och genomför några valideringsexperiment. Resultaten visar att BGPcredit kan fungera bra och är kompatibel med BGP routing nätverk.
85

Spårning av inkommande trafik till anycastnoder / Tracking incoming traffic to anycast nodes

Petersson, Alexander January 2022 (has links)
Att en hemsida tar extra lång tid att ladda är inte ovanligt och kan bero på att trafiken från en klient tar en helt annan väg till hemsidans server än den som är geografiskt närmast. Orsaken bakom problemet är att DNS-förfrågningarna färdas onödigt långa sträckor. NetNod är ett företag som tillhandahåller dessa internettjänster, bland annat rotservrar runt om i världen. De vill ta reda på varför trafik från olika klienter inte alltid går den geografiskt närmaste vägen till deras anycastnoder Problemställningen för examensarbetet är att analysera varifrån trafik till företagets anycastnod i Miami kommer. Realiseringen av detta gjordes genom att utveckla en programkod som markerade geografisk placering av olika klienter utifrån deras IP-adress. Förinspelade trafikdata från NetNod analyserades. Detta gjordes för att visa på vilka problem som observeras i peering och anycastrouting mellan internetprotokoll. Resultatet redovisades med en karta med markeringar av de IP-adresser där deras trafik analyserades för att se hur det transporterades till anycastnoden. Utifrån detta har resultatet visat på vilka avvikelser och mönster som uppstått inom BGP-routing när trafiken färdas till anycastnoden. De avvikelser som hittats är hur olika routingregler manipulerat trafikens transport till anycastnoden och gör att trafiken från klienterna inte tar den geografiskt närmaste vägen till anycastnoden. / The fact that a website takes an unusually long time to load is not uncommon. This can be due to a client taking a different path to the websites server than one that is geographically closer. One reason behind this problem is that DNS-queries travel unnecessarily long distances. NetNod is a company that provides internet services and maintains one of the few root-servers around the world. The company wants to know why traffic from different clients do not always go via the geographically closest route to anycast nodes. The objective of the thesis is to analyze where traffic to NetNods anycast node in Miami geographically originates from. In order to do this, a computer program was developed in which plots the geographical location of different clients from their IP-address. Pre-recorded data from the company was used as a data source for the program. This was done to show different challenges in peering and anycast routing between internet protocols. The result is presented via a map with plots of where the IP-addresses are geographically coming from to the anycast node in Miami, it was generated by the developed program. The generated map showed anomalies and patterns of how the traffic is transported in large junctions as well as how routing rules are applied, this is one reason to why the traffic does not always go the geographically closest route.
86

Geo-distributed application deployment assistance based on past routing information / Utplacering av geografiskt distribuerade applikationer baserat på tidigare routing information

Falgert, Marcus January 2017 (has links)
Cloud computing platforms allow users to deploy geographically distributed applications on servers around the world. Applications may be simple to deploy on these platforms, but it is up to the user and the application to decide which regions and servers to use for application placement. Furthermore, network conditions and routing between the geo-distributed servers change over time, which can lead to sub-optimal performance of applications deployed on such servers. A user could either employ a static deployment configuration of servers, or attempt to use a more dynamic configuration. However, both have inherent limitations. A static configuration will be sub-optimal, as it will be unable to adapt to changing network conditions. A more dynamic approach where an application could switch over or transition to a more suitable server could be beneficial, but this can be very complex in practice. Furthermore, such a solution is more about adapting to change as it happens, and not beforehand. This thesis will investigate the possibility of forecasting impending routing changes between servers, by leveraging messages generated by the Border Gateway Protocol (BGP) and past knowledge about routing changes. BGP routers can delay BGP updates due to factors such as the minimum route advertisement interval (MRAI). Thus, out proposed solution involves forwarding BGP updates downstream in the network, before BGP routers process them. As routing between servers changes, so does the latency, meaning that the latency then could be predicted to some degree. This observation could be applied to realize when the latency to a server increases or decreases past another server. This in turn facilitates the decision process of selecting the most optimal servers in terms of latency for application deployment. The solution presented in this thesis can successfully predict routing changes between end-points in an enclosed environment, and inform users ahead of time that the latency is about to change. The time gained by such predictions depend on factors such as the number of ASs between the end-points, the MRAI, and the update processing delay imposed on BGP routers. Time gains between tens of milliseconds to over 2 minutes has been observed.
87

An online environmental approach to service interaction management in home automation

Wilson, Michael E. J. January 2005 (has links)
Home automation is maturing with the increased deployment of networks and intelligent devices in the home. Along with new protocols and devices, new software services will emerge and work together releasing the full potential of networked consumer devices. Services may include home security, climate control or entertainment. With such extensive interworking the phenomenon known as service interaction, or feature interaction, appears. The problem occurs when services interfere with one another causing unexpected or undesirable outcomes. The main goal of this work is to detect undesired interactions between devices and services while allowing positive interactions between services and devices. If the interaction is negative, the approach should be able to handle it in an appropriate way. Being able to carry out interaction detection in the home poses certain challenges. Firstly, the devices and services are provided by a number of vendors and will be using a variety of protocols. Secondly, the configuration will not be fixed, the network will change as devices join and leave. Services may also change and adapt to user needs and to devices available at runtime. The developed approach is able to work with such challenges. Since the goal of the automated home is to make life simpler for the occupant, the approach should require minimal user intervention. With the above goals, an approach was developed which tackles the problem. Whereas previous approaches solving service interaction have focused on the service, the technique presented here concentrates on the devices and their surrounds, as some interactions occur through conflicting effects on the environment. The approach introduces the concept of environmental variables. A variable may be room temperature, movement or perhaps light. Drawing inspiration from the Operating Systems domain, locks are used to control access to the devices and environmental variables. Using this technique, undesirable interactions are avoided. The inclusion of the environment is a key element of this approach as many interactions can happen indirectly, through the environment. Since the configuration of a home’s devices and services is continually changing, developing an off-line solution is not practical. Therefore, an on-line approach in the form of an interaction manager has been developed. It is the manager’s role to detect interactions. The approach was shown to work successfuly. The manager was able to successfully detect interactions and prevent negative interactions from occurring. Interactions were detected at both device and service level. The approach is flexible: it is protocol independent, services are unaware of the manager, and the manager can cope with new devices and services joining the network. Further, there is little user intervention required for the approach to operate.
88

Ger?ncia de redes sensores sem fio com SNMP: uma abordagem com proxy gateway / Using SNMP for wireless sensor network management: an approach with a proxy gateway

Madeira, John Franklin Loiola 21 June 2013 (has links)
Made available in DSpace on 2016-04-04T18:31:42Z (GMT). No. of bitstreams: 1 John F L Madeira.pdf: 1208031 bytes, checksum: cacbe507cfeea663dc6feac02f58faa7 (MD5) Previous issue date: 2013-06-21 / This paper presents an approach to management of wireless sensor network (WSN) with the use of the Simple Network Management Protocol (SNMP). In this proposal, was implemented a new element called SNMP Proxy Gateway (SPG) that has aimed to make the interconnection of management without the need for modification or adaptation of the stack TCP/IP protocols. Thus, a new implementation based in hardware and software were deployed to make the transition of SNMP PDUs for WSN. A set of experiments were made in laboratory to test and validate the proposed results. / Este trabalho apresenta uma abordagem para ger?ncia de rede sensores sem fio (RSSF) com utiliza??o do Simple Network Management Protocol (SNMP). Nesta proposta, foi introduzido elemento chamado SNMP Proxy Gateway (SPG) que tem objetivo de fazer a interconex?o das arquiteturas de rede para ger?ncia sem a necessidade de altera??o ou adapta??o da pilha de protocolos TCP/IP. Para isso, foi implementado prot?tipo de ger?ncia da rede atrav?s de um conjunto hardware e software com fun??o de fazer a transcri??o dos PDUs do SNMP para a RSSF. Um conjunto de experimentos foram executados em laborat?rio com objetivo de testar a proposta e validar os resultados obtidos.
89

Entrepreneurship in Pietermaritzburg, South Africa - A four year follow-up.

Karlsson, Karl January 2006 (has links)
<p>The study is based on the need for economic development and higher employment in South Africa. Political measures encourage organisations, like the Christian, non-governmental organisation, Project Gateway to educate disadvantaged groups in entrepreneurship. Through interviews, I have studied a group of 23 entrepreneurs, who participated in the program four years ago. I was able to find 15 people, of who two fulfilled Project Gateways goal of the program. I do find this to be low and recommend that the organisation work on networking, changes in the mentorship program, education in Zulu and encouraging lending awareness among the students.</p> / <p>Denna studie grundar sig i behovet av arbeten och ekonomisk utveckling i Syd Afrika. Politiska åtgärder uppmuntrar organisationer som den kristna frivillige organisationen Project Gateway att utbilda utsatta grupper i entreprenörskap. Genom intervjuer har jag undersökt en grupp på 23 entreprenörer, fyra år efter det att de deltog i programmet. Av dessa hittade jag 15 personer varav 2 uppfyllde Projects Gateways mål med utbildningen. Detta anser jag vara lågt och rekommenderar organisationen att prioritera nätverks byggande, förändringar i mentorskaps programmet, utbildning i Zulu och kunskap i hur man lånar pengar för att starta företag.</p>
90

Prototyp av en VoIP/PSTN-gateway / Prototype of a VoIP/PSTN gateway

Broström, Anders, Kihlstadius, Niclas January 2007 (has links)
<p>Under de senaste åren har Internettelefonin varit på frammarsch, och i takt med att tekniken mognat har fler och fler börjat se den som ett alternativ till att ringa via telefonnätet. Förutom att det är billigare att ringa över det förstnämnda, så erbjuder Internettelefonin också en rad revolutionerande tjänster. Det är dock troligt att telefonnätet kommer att få tjänstgöra i många år till, och det erbjuder fortfarande överlägset bäst stabilitet och har stor acceptans. Om de två telefoninätverken ska existera sida vid sida, med varsina användarbaser är det lämpligt om de kan fås att samverka, så att användare av det ena kan ringa användare av det andra, och vice versa. Detta kan göras med en VoIP/PSTN-gateway, som översätter kontrollinformation och rösttrafik mellan de två nätverken.</p><p>Uppsatsen handlar om det arbete vi har utfört år TietoEnator i Karlstad. Uppgiften bestod i att utveckla en prototyp av en VoIP/PSTN-gateway. Från början var det avsett att systemet skulle klara uppringning från endera en ”vanlig” telefon, eller en så kallad IP-telefon. Därtill skulle rösttrafiken överföras genom ändamålsenlig hårdvara. För att utföra arbetet behövde vi först studera relevanta kommunikationsprotokoll både för telefonnätet och för Internet, för att se hur dessa kunde fås att samverka. Vi behövde också lära oss tillgängliga system, bibliotek och verktyg för att förstå hur vi skulle skapa vårt eget system i den efterkommande implementeringsfasen. På grund av en lång inläsningsperiod och inledande tekniska problem, samt att nödvändig hårdvara för översättning av rösttrafiken inte anlände i tid begränsades arbetet till att innefatta samtal initierade från den vanliga telefonen till ip-telefonen, utan röstöverföring. Likväl har ett resultatgivande arbete utförts, och det beskrivs i detalj i rapporten.</p> / <p>During the past few years Internet telephony has advanced rapidly, and as the technology has evolved, more and more have come to consider it an alternative to making phone calls through the telephone network. Besides being cheaper, Internet telephony also provides several revolutionary services. It is likely though that the telephone network will remain in use for several years to come, and it still offers by far the best stability and is accepted by most people. If the two networks are to coexist, with their respective users, it would be useful if they could be made to interact, so that users of one network can call users of the other, and vice versa. This can be done with a VoIP/PSTN gateway, which translates control information and voice traffic between the two networks.</p><p>Our dissertation is about the work we have performed for TietoEnator in Karlstad. The assignment was to develop a prototype of a VoIP/PSTN gateway. Initially the system was meant to support phone calls initiated either from an “ordinary” phone or from an IP telephone. Also the voice traffic was supposed to be translated with the use of appropriate hardware. To manage this we first needed to study all the relevant protocols for communication used in the telephone network and on the Internet, to get an idea of how these could be made to interact. We also had to learn existing systems, libraries and tools in order to see how we could create our own system. Due to a long learning period and technical problems in the beginning, and because the necessary hardware equipment for translation of voice traffic did not arrive in time, the assignment was limited to include only calls initiated from the ordinary phone to the IP telephone, without voice transmission. Never the less, the efforts have produced results, and our work is explained in detail in this dissertation.</p>

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