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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.
731

A Move Towards Practicability : Context Information and User Profile Management for the SensibleThings Platform

Chukala, Sileshi January 2016 (has links)
Achievements in academia and industry indicate a move towards the creation of a giant smart system including objects of different sizes, shapes, and purposes where the Internet will be so diverse and more resourceful with the incorporation of different smart devices. Mid Swe-den University took a first step towards providing an appropriate plat-form for Internet of Things applications known as SensibleThings for the emerging intercommunication of “objects”, called Internet of Things. The SensibleThings platform has produced components for sharing sensor-based context information on the Internet, in order to enable Internet of Things applications. In this thesis the plan was to contribute to filling the gap between the IoT and developers in academia as well as in the industries. The aim of the project was to create basic functionality to enable users to find new interesting users on the IoT and prioritize existing users. To this end context information and user profile man-agement is proposed and presented. Furthermore, a comparison be-tween the platform with the proposed extension as well as without was compared and examined.
732

Evaluation of Cryptographic Packages

Raheem, Muhammad January 2009 (has links)
The widespread use of computer technology for information handling resulted in the need for higher data protection.The usage of high profile cryptographic protocols and algorithms do not always necessarily guarantee high security. They are needed to be used according to the needs of the organization depending upon certain characteristics and available resources.The communication system in a cryptographic environment may become vulnerable to attacks if the cryptographic packages don’t meet their intended goals. This master’s thesis is targeted towards the goal of evaluating contemporary cryptographic algorithms and protocols collectively named as cryptographic packages as per security needs of the organization with the available resources. The results have shown that there certainly is a need for careful evaluations of cryptographic packages given with available resources otherwise it could turn into creating more severe problems such as network bottlenecks, information and identity loss, non trustable environment and computational infeasibilities resulting in huge response times. In contrast, choosing the right package with right security parameters can lead to a secure and best performance communication environment.
733

Replacing OSE with Real Time capable Linux

Boman, Simon, Rutgersson, Olof January 2009 (has links)
For many years OSE has been a common used operating system, with real time extensions enhancements, in embed-ded systems. But in the last decades, Linux has grown and became a competitor to common operating systems and, in recent years, even as an operating system with real time extensions. With this in mind, ÅF was interested in replacing the quite expensive OSE with some distribution of the open source based Linux on a PowerPC MPC8360. Therefore, our purpose with thesis is to implement Linux on the named platform and make some tests to see if it is possible to replace OSE with Linux. Using Linux has several advantages, for example it is free of charge to use and over the years the popularity of Linux within the developer community has resulted in numerous tools and utilities available for free. As a result, this study shows that Linux with real time extensions on the MPC8360 PowerPC platform is a viable alternative to OSE regarding cost efficiency, flexibility, adaptability and competence available on the market. Further studies can be done towards benchmarking for I/O systems and implementing support for more hardware on the MPC8360 AF platform.
734

Implementation of a Gigabit IP router on an FPGA platform

Borslehag, Tobias January 2005 (has links)
The computer engineering group at Linköping University has parts of their research dedicated to networks-on-chip and components used in network components and terminals. This research has among others resulted in the SoCBUS NOC and a flow based network protocol processor. The main objective of this project was to integrate these components into an IP router with two or more Gigabit Ethernet interfaces. A working system has been designed and found working. It consists of three main components, the input module, the output module and a packet buffer. Due to the time constraint and the size of the project the packet buffer could not be designed to be as efficient as possible, thus reducing the overall performance. The SoCBUS also has negative impact on performance, although this could probably be reduced with a revised system design. If such a project is carried out it could use the input and output modules from this project, which connect to SoCBUS and can easily be integrated with other packet buffers and system designs.
735

Design and implementation of a hardware unit for complex division

Alfredsson, Erik January 2005 (has links)
The purpose of the thesis was to investigate and evaluate existing algorithms for division of complex numbers. The investigation should include implementation of a few suitable algorithms in VHDL. The main application for the divider is compensation for fading in a baseband processor. Since not much public research is done within the area of complex division in hardware, a divider based on real valued division was designed. The design only implements inversion of complex numbers instead of complete division because it is simpler and the application does not need full division, thus the required chip size is reduced. An examination of the different kinds of algorithms that exists for real valued division was done and two of the methods were found suitable for implementation, digit recurrence and functional iteration. From each of the two classes of algorithms one algorithm was chosen and implemented in VHDL. Two different versions of the inverter were designed for each method, one with full throughput and one with half throughput. The implementations show very similar results in terms of speed, size and performance. For most cases however, the digit recurrence implementation has a slight advantage.
736

Fully Integrated and Switched Test Environment and Automated Testing (FIST@)

Yan, Jing January 2006 (has links)
This thesis examines the possibility of designing a fully integrated and switched testing environment for a test laboratory which conducts automated testing. Execution of tests in this environment will make it possible to manage all test objects without requiring any manual intervention resulting in efficient utilization of machine hours and test objects. The thesis explores the concepts and requirements for designing such an environment. It also describes the methods to implement the environment. The result of the thesis work shows that it is possible to design and implement a fully integrated and switched testing environment which can reduce the lead time for delivery by a substantial amount along with a more efficient utilization of machine hours and resources. The exact information related to the instruments, devices under testing and tools are removed by the author according to NDA.
737

Design of a Gigabit Router Packet Buffer using DDR SDRAM Memory / Design av en Packetbuffer för en Gigabit Router användandes DDR Minne

Ferm, Daniel January 2006 (has links)
The computer engineering department at Linköping University has a research project which investigates the use of an on-chip network in a router. There has been an implementation of it in a FPGA and for this router there is a need for buffer memory. This thesis extends the router design with a DDR memory controller which uses the features provided by the Virtex-II FPGA family. The thesis shows that by carefully scheduling the DDR SDRAM memory high volume transfers are possible and the memory can be used quite effciently despite its rather complex interface. The DDR memory controller developed is part of a packet buffer module which is integrated and tested with a previous, slightly modifed, FPGA based router design. The performance of this router is investigated using real network interfaces and due to the poor network performance of desktop computers special hardware is developed for this purpose.
738

Testverktyg för programvara skriven i Ada

Lindh, Hanna January 2005 (has links)
Syftet med den här rapporten är att undersöka om det finns något testverktyg som uppfyller kraven från Saab Underwater Systems. I rapporten presenteras även en sammanfattning av testningens grunder och metoder för att välja ut och utvärdera datorprogram. Arbetet med att välja ut och utvärdera testverktyg kan ses som en process. Först ska kraven sammanställas och sedan ska några verktyg väljas ut för utvärdering. Två av de tre verktyg som valdes ut utvärderades mer ingående. De två testverktyg som utvärderades var LDRA Testbed och AdaTEST 95. LDRA Testbed har väldigt många olika statiska analyser vilket i många fall troligen inte kommer att utnyttjas. Enhetstestningen sker med hjälp av TBrun som är en del av verktygsserien som LDRA marknadsför. AdaTEST 95 har inte lika många funktioner som LDRA Testbed men har de nödvändiga statiska analyserna och enhetstestning presenterade i ett enklare gränssnitt. Båda verktygen uppfyller de viktigaste kraven från Saab Underwater Systems, men inget av dem uppfyller alla krav. Båda verktygen skulle kunna underlätta testningen men AdaTEST 95 rekommenderas. AdaTEST 95 är framtaget för att underlätta för i första hand utvecklare och det är utvecklare som ska använda verktyget på Saab Underwater Systems.
739

Datoriserat beslutsstöd vid mätning av dornprofil

Hedman, Erik January 2006 (has links)
Behovet att mäta kvalitet hos olika produkter ledde till framställningen av ett antal mätningsmetoder. Redan vid olika stadier av tillverkning kan man avgöra om produkten motsvarar en viss förutbestämd standard. Den här rapporten kommer att undersöka vilka eventuella problem mätning av kvalitet med laser har i industrimiljö. En konceptuell modell över hur mätning av dornprofiler kan genomföras kommer att presenteras med fokus på att väga tidsåtgång mot exakthet för att skapa en balans som är acceptabel för företagets krav. En beslutsfattande algoritm kommer även att presenteras där ett avgörande ska ske om mätresultaten är rimliga eller beror på fel i mätutrustningen. Om mätresultaten är rimliga jämförs de mot referensvärden för att avgöra om produkten klarar kvalitetskraven. Resultatet presenteras i form av ett program som styr hela mätproceduren samt även fattar ett beslut om den aktuella mätningen ska förkastas eller behållas.
740

Workflow management systems, their security and access control mechanisms

Chehrazi, Golriz January 2007 (has links)
This paper gives an overview of workflow management systems (WfMSs) and their security requirements with focus on access mechanisms. It is a descriptive paper in which we examine the state of the art of workflow systems, describe what security risks affect WfMSs in particular, and how these can be diminiuished. WfMSs manage, illustrate and support business processes. They contribute to the performance, automation and optimization of processes, which is important in the global economy today. The security of process flows is important, since the sensitive business data need to be protected to inhibit illegal activities, such as blackmailing, imitation and fraud and to provide for good customer service. This paper focuses on access mechanisms, because they are basic security mechanisms used by WfMSs assuring that only authorized users are provided access to data and resources. Also because of the unsecurity of the Internet, which is commonly used as infrastructure of Workflow systems, additional security mechanisms, such as PKIs, digital signatures and SSL have to be used to provide secure workflows. Depending on the particular requirements in workflow systems, different extensional access control (AC) mechanisms have been developed to maintain security. But when it comes to commercially used WfMSs, the availability of the system is of utmost importance. It is the prerequisite for the system to be employed by companies. The problem is that there is always a trade-off between availability of the system and security. Because this trade off is generally solved in favor of availability, a major part of the developed AC mechanisms are not used in commercially used WfMS. After the first part of this paper which is rather theoretical, we examine a commercial WfMS, namely IBM's MQ Workflow , and its security mechanisms. We show vulnerabilities of the system that could be abused by attackers. Afterwards, we show which security mechanisms, in particular, AC mechanisms are provided to secure against threats. We conclude with a summary, which highlights the difference between security concepts developed in the research area and those really implemented by the commercially used WfMS.

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