<p>WLANs are become popular due to their different advantages. Beside all these advantages WLANs are also facing the major problem of the security, so that why lots of people are doing research on WLAN to improve the security because many companies want to transfer their sensible data over WLAN.</p><p>This report discusses the security issues of WLAN based on IEEE 802.11 standard, such type of networks are referred to as wifi network. WLAN is deployed as an extension of already existed wired LAN. Therefore it is necessary to provide the security of WLAN equals to Wired LAN.</p><p>We worked in a lab environment in order to configure the three different security solutions (WEP, WPA & WPA2 using IEEE 802.1X and RADIUS Server) on infrastructure mode for personnel and enterprise architecture of WLAN. For each security solution we used the backtrack as a security cracking tool, in order to break the WEP (64 and 128 bit long) security key of WLAN, make comparison between 64 and 128 bit long WEP key and also analyzed the different kind of attacks  and some drawbacks of using WEP security in WLAN. In the same way configure the WPA and WPA2 (using IEEE 802.1X and RADIUS Server) security solution in infrastructure mode of WLAN and use the same security cracking tool backtrack in order to break the security of the WLAN and analyze the different attacks on the network in these architecture and drawbacks of using WPA and WPA2 Security solutions. By using IEEE 802.1X and RADIUS Server we can improve the security of the enterprise network.</p><p>In the end we come with many conclusions and suggestions that will help in order to provide better security while deploying Wireless LAN.</p> / Opponents: Ali Murtaza & Mansoor Ahmed

With the presence of smartphones and tablets people are getting used to control their technicaldevices at home with custom applications. This thesis explores the possibility of controlling an IPSet-Top-Box from an external device.The focus of this report and thesis is finding a way for external devices to control IP-Set-Top-Boxesrunning the KreaTV platform. To open up for this possibility a service running in the KreaTVplatform was designed and implemented to handle communication from external devices. Aprotocol for communication was structured and defined to allow devices to communicate with theplatform.The protocol includes a base structure defined for general use when communicating withapplications and services in the platform. The base structure was extended and defined forcommunication with the Set-Top-Box application running the graphical user interface.An Android application was used to demonstrate that the design solution presented in this reportopens up for the possibility of external devices to control the IP-Set-Top-Box beyond the limitationsof a normal infrared remote control. The Android applications main focus is controlling the Spotifyservice of the IP-Set-Top-Box.

No description available.

<p>As an interface between radio receiver front-ends and digital signal processing blocks, sampling devices play a dominant role in digital radio communications. As an interface between radio receiver front-ends and digital signal processing blocks, sampling devices play a dominant role in digital radio communications. Based on different sampling theorems (e.g., classic Shannon’s sampling theorem, Papoulis’ Generalized sampling theorem, bandpass sampling theory), signals are processed by the sampling devices and then undergo additional processing. It is a natural goal to obtain the signals at the output of the sampling devices without loss of information. In conventional radio receivers, all the down-conversion and channel selection are realized in analog hardware. The associated sampling devices in A/D converters are based on the classic Shannon’s sampling theorem. Driven by the increased speed of microprocessors, there is a tendency to use mixed-signal/digital hardware and software to realize more functions (e.g., down-conversion, channel selection, demodulation and detection) in a radio communication system. The new evolution of radio receiver architecture is Software Defined Radio (SDR). One design goal of SDR is to put the A/D converter as close as possible to the antenna. BandPass Sampling (BPS) enables one to have an interface between the higher IF and the A/D converter by a sampling rate of 2B or more (B is the information bandwidth), and it might be a solution to SDR. A signal can be uniquely determined from the samples by NonUniform Sampling (NUS) such that NUS has the potential to suppress harmful signal spectrum aliasing. BPS makes use of the signal spectrum aliasing to represent the signal uniquely at any band position. A harmful aliasing of signal spectrum will cause a performance degradation. It is of great benefit to use NUS scheme in BPS system. However, a signal cannot be recovered from its nonuniform samples by using only an ideal lowpass filter (or the classic Shannon’s reconstruction function). The reconstruction of the samples by NUS is crucial for the implementation of NUS. Besides the harmful signal spectrum aliasing, noise aliasing and timing jitter are other two sources of performance degradation in a BPS system. Noise aliasing is the direct consequence of lower sampling rate of subsampling. With the increase of input frequency by directly sampling a signal at higher IF, the timing error of the sampling clock causes large jitter effects on the sampled-data signal. In this thesis work, first, a filter generalized by a certain Reconstruction Algorithm (RA) is proposed to reconstruct the signal from its nonuniform samples. A Based on different sampling theorems (e.g., classic Shannon’s sampling theorem, Papoulis’ Generalized sampling theorem, bandpass sampling theory), signals are processed by the sampling devices and then undergo additional processing. It is a natural goal to obtain the signals at the output of the sampling devices without loss of information. In conventional radio receivers, all the down-conversion and channel selection are realized in analog hardware. The associated sampling devices in A/D converters are based on the classic Shannon’s sampling theorem. Driven by the increased speed of microprocessors, there is a tendency to use mixed-signal/digital hardware and software to realize more functions (e.g., down-conversion, channel selection, demodulation and detection) in a radio communication system. The new evolution of radio receiver architecture is Software Defined Radio (SDR). One design goal of SDR is to put the A/D converter as close as possible to the antenna. BandPass Sampling (BPS) enables one to have an interface between the higher IF and the A/D converter by a sampling rate of 2B or more (B is the information bandwidth), and it might be a solution to SDR. A signal can be uniquely determined from the samples by NonUniform Sampling (NUS) such that NUS has the potential to suppress harmful signal spectrum aliasing. BPS makes use of the signal spectrum aliasing to represent the signal uniquely at any band position. A harmful aliasing of signal spectrum will cause a performance degradation. It is of great benefit to use NUS scheme in BPS system. However, a signal cannot be recovered from its nonuniform samples by using only an ideal lowpass filter (or the classic Shannon’s reconstruction function). The reconstruction of the samples by NUS is crucial for the implementation of NUS. Besides the harmful signal spectrum aliasing, noise aliasing and timing jitter are other two sources of performance degradation in a BPS system. Noise aliasing is the direct consequence of lower sampling rate of subsampling. With the increase of input frequency by directly sampling a signal at higher IF, the timing error of the sampling clock causes large jitter effects on the sampled-data signal. In this thesis work, first, a filter generalized by a certain Reconstruction Algorithm (RA) is proposed to reconstruct the signal from its nonuniform samples. A</p>

<p>This thesis describes the function and construction of a modular event detector system. Event detectors are used for solder joint reliability testing using electronic monitoring for short duration resistance changes during accelerated ageing and temperature cycling. Collected data is mainly used to study solder joints long-term properties. The system has three different monitoring functions: transient resistance detection, statistics process monitoring and periodic monitoring. In its present performance a total number of 384 channels can be monitored continuously. However the system can be expanded in steps of 96 channels, limited only by the capacity of the computers PCI-bus. The system is built around a PC equipped with the LabVIEW 6.1 programming environment and data acquisition cards from National Instruments. The circuit boards to be monitored are connected via adapter electronics. In the case of the superior electronic-kits project, four groups of 24 circuit boards are connected to the adapter electronics. To minimise the influence of environmental noise shielded and, where possible, twined cables are used.</p>

Estimations of the Worst-Case Execution Time (WCET) are required in providing guarantees for timing of programs used in computer controlled products and other real-time computer systems. To derive program WCET estimates, both the properties of the software and the hardware must be considered. The traditional method to obtain WCET estimates is to test the system and measure the execution time. This is labour-intensive and error-prone work, which unfortunately cannot guarantee that the worst case is actually found. Static WCET analyses, on the other hand, are capable of generating safe WCET estimates without actually running the program. Such analyses use models of program flow and hardware timing to generate WCET estimates. This thesis includes several contributions to the state-of-the-art in static WCET analysis: (1) A tool architecture for static WCET analysis, which divides the WCET analysis into several steps, each with well-defined interfaces. This allows independent replacement of the modules implementing the different steps, which makes it easy to customize a WCET tool for particular target hardware and analysis needs. (2) A representation for the possible executions of a program. Compared to previous approaches, our representation extends the type of program flow information possible to express and handle in WCET analysis. (3) A calculation method which explicitly extracts a longest program execution path. The method is more efficient than previously presented path-based methods, with a computational complexity close to linear in the size of the program. (4) A calculation method using integer linear programming or constraint programming techniques for calculating the WCET estimate. The method extends the power of such calculation methods to handle new types of flow and timing information. (5) A calculation method that first uses flow information to divide the program into smaller parts, then calculates individual WCET estimates for these parts, and finally combines these into an overall program WCET. This novel approach avoids potential complexity problems, while still providing high precision WCET estimates. We have additionally implemented a prototype WCET analysis tool based on the proposed architecture. This tool is used for extensive evaluation of the precision and performance of our proposed methods. The results indicate that it is possible to perform WCET analysis in a modular fashion, and that this analysis produces high quality WCET estimates.

A way to create well-functioning computer systems is to automate error detection in the systems. Automated techniques for finding errors, such as testing and formal verification, requires a model of the system. The technique for constructing deterministic finite automata (DFA) models, without access to the source code, is called regular inference. The technique provides sequences of input, so called membership queries, to a system, observes the responses, and infers a model from the input and responses. This thesis presents work to adapt regular inference to a certain kind of systems: communication protocol entities. Such entities interact by sending and receiving messages consisting of a message type and a number of parameters, each of which potentially can take on a large number of values. This may cause a model of a communication protocol entity inferred by regular inference, to be very large and take a long time to infer. Since regular inference creates a model from the observed behavior of a communication protocol entity, the model may be very different from a designer's model of the system's source code. This thesis presents adaptations of regular inference to infer more compact models and use less membership queries. The first contribution is a survey over three algorithms for regular inference. We present their similarities and their differences in terms of the required number of membership queries. The second contribution is an investigation on how many membership queries a common regular inference algorithm, the L* algorithm by Angluin, requires for randomly generated DFAs and randomly generated DFAs with a structure common for communication protocol entities. In comparison, the DFAs with a structure common for communication protocol entities require more membership queries. The third contribution is an adaptation of regular inference to communication protocol entities which behavior foremost are affected by the message types. The adapted algorithm avoids asking membership queries containing messages with parameter values that results in already observed responses. The fourth contribution is an approach for regular inference of communication protocol entities which communicate with messages containing parameter values from very large ranges. The approach infers compact models, and uses parameter values taken from a small portion of their ranges in membership queries. The fifth contribution is an approach to infer compact models of communication protocol entities which have a similar partitioning of an entity's behavior into control states as in a designer's model of the protocol.

Rapporten undersöker huruvida en användning av ljud kan minska tiden för att nå ett objekt. Fitts’s lag är en välkänd lag som beskriver hur lång tid det tar för en användare att nå ett objekt. Genom en studie utvärderas till vilken grad olika sorters ljudtillägg kan förbättra de förväntade resultaten utifrån Fitts’s lag i ett 2-dimensionellt gränssnitt. Användarna presterade generellt mer tidseffektivt då ljud användes för att vägleda deras rörelse mot objekten. Vilken effekt ljudtilläggen hade på tiden att utföra rörelsen varierade mellan olika ljudmönster och objektens storlek. Resultaten indikerar på att en användning av ljud mycket väl kan vara ett värdefullt verktyg inom interaktionsdesign.

<p>Rapporten syftar till att titta på lösningar som kan ge minskade energikostnader i datacenters, med fokus på bladservrar, virtualisering och kylning. Vi undersöker hur man skulle kunna spara in på energin genom användandet av de olika teknikerna. Resultaten pekar på att bladservrar minskar strömförbrukningen jämfört med en motsvarande rackserver, samtidigt som virtualisering radikalt kan minska strömförbrukningen då man får ner antalet fysiska servrar. Även kylningen spelar stor roll när man ser till vad som förbrukar mest energi i datacentret. En hel del åtgärder finns att vidta för att effektivisera kylningen för att både få ner strömförbrukningen men även för att bättre kunna kyla alla servrar. Genomförda tester både vad gäller bladservrar och virtualisering visar på att det finns fördelar att vinna med användandet av dessa båda tekniker.</p>

This study has investigated the development of a web application in the form of a digital marketplace for IT services. The problem statement addresses how a web application of this kind can be designed to achieve three criteria; high usability, good user experience and high credibility. These factors are important to attract users to the web application, and in this way connect contractors and outsourcers for IT services. The web application has been tested iteratively during the development process to corroborate whether the implementation achieves the three criteria. This process has led to a final result of a web application that, according to performed tests, meets these criteria. A high navigability on the web application has been achieved through implementing a layout based on the four primary objectives of navigability and on a distinct connection between all pages. Furthermore, the web application’s readability has been developed with a distinct vocabulary and a font adapted to the operating system and unit the web application is run on. An appealing design has been formed through implementing a layout with color selection based on theory, that strengthens the user’s impression of the application. A responsive design has been implemented by having both a well-adapted layout and appropriate content. The web application’s high credibility has been formed by forging the application based on the seven guidelines for credibility. The conclusion drawn is that the method that has been presented is applicable to achieve the three criteria; usability, user experience and credibility. This conclusion does not only apply to web applications in the form of digital marketplaces, but also to web applications in general. / Studien har undersökt utvecklingen av en webbapplikation i form av en digital annonseringsplats för IT-tjänster. Frågeställningen behandlar hur en webbapplikation av denna karaktär kan utformas för att uppnå tre kriterier; hög användbarhet, god användarupplevelse samt hög trovärdighet. Dessa faktorer är viktiga för att locka användare till webbapplikationen, och på så sätt sammankoppla uppdragstagare och uppdragsgivare för IT-tjänster. Webbapplikationen har iterativt testats under utvecklingens gång för att generera förbättringsområden som säkerställer att webbapplikationen uppnår de tre kriterierna. Denna process har lett till ett slutgiltigt resultat i form av en webbapplikation som, baserat på utförda tester, uppnår dessa kriterier. En hög navigerbarhet på webbapplikationens har uppnåtts genom att implementera en layout grundad i navigerbarhetens fyra huvudmål samt en tydlig koppling mellan applikationens samtliga sidor. Webbapplikationens läsbarhet har utvecklats genom att använda en tydlig vokabulär samt typsnitt anpassade efter det operativsystem och den enhet webbapplikationen körs på. Tilltalande design uppnås genom att implementera en layout med färgval grundade i teorin, som stärker användarens intryck av webbapplikationen. Vidare har webbapplikationens responsivitet formats genom en välanpassad layout med lämpligt innehåll. Webbapplikationens höga trovärdighet grundar sig i att applikationen utformats efter trovärdighetens sju riktlinjer. Den slutsats som dragits är att metoden som presenterats är tillämpningsbar för att en webbapplikation ska inneha navigerbarhet, läsbarhet, tilltalande och responsiv design samt tillförlitlig utformning och betalning som således leder till hög användbarhet, god användarupplevelse samt hög trovärdighet. Denna slutsats gäller inte enbart för webbapplikationer i form av digitala annonseringsplatser, utan även för webbapplikationer i allmänhet.