Planar nanostructures made of noble metal can efficiently control transmission of light, thanks to surface plasmon polaritons (SPPs) mediated through interaction between such a structure and incoming light. In this thesis, we numerically characterize, with a 3D finiteelement method, three types of plasmonic devices: plasmonic radial/azimuthal filter, plasmonic quarter-wave plate made of a periodic array of round holes in a thin metallic film, and a plasmonic quarter-wave plate with a periodic array of cross-shaped apertures. The plasmonic polarization filter is formed by a series of concentric equidistant gold rings, and it can transmit the radially polarized light and block the azimuthally polarized light. The quarter-wave plate with round holes has a different lattice constant along two Cartesiancoordinate directions that enable different phase retardations for two orthogonally polarized incident waves; hence, it can convert a linearly polarized light to a circularly polarized light. For the quarter-wave plate with an array of cross-shaped apertures, it utilizes the different lengths of horizontal/vertical arms to manipulate the phase retardations. All of these devices have sub-micron thicknesses, unlike their traditional counterparts that are bulky and inconvenient for integration purposes. Fabrication of the wave plate with cross-shaped apertures was attempted in collaboration with members in the Optics and Photonics unit at KTH.

Spel på internet är populärare än någonsin i dagens samhälle, det är en industri som omsätter stora summor pengar varje år. Fler och fler människor söker sig till dessa spelsajter. Hur kan du som spelare vara säker på att dina motståndare spelar på samma villkor? Arbetet som utförts på KTH undersöker hur programmet på användarens egen dator kan exploateras för att vinna fördelar i spelet. Endast minnesinjektion kommer att undersökas i detta syfte. Olika tekniker för minnesinjektion samt förslag på hur applikationer kan göras säkrare presenteras i denna rapport. PokerStat är ett program som utvecklats i ett demonstrativt syfte för att visa hur minnesinjektion kan användas för att exploatera en pokerklient. PokerStat räknar ut sannolikheten för att få olika pokerhänder under tiden en aktiv hand spelas. Det visar tydligt vikten av att tänka på informationen som lagras i minnet för applikationen. En undersöknings som genomförts parallellt med arbetet visade på att majoriteten av undersökningens deltagare inte klassificerade användning av PokerStat som fusk. Trots detta ville en klar majoritet inte att sådan funktionalitet skulle implementeras direkt i pokerklienten. Resultatet av undersökningen visar på att PokerStat ger en fördel som användare inte vill ska finnas lättillgängligt för alla spelare men fördelen är inte så pass stor att den bör klassificeras som fusk. / Online games are more popular today than ever, it is an industry that turns over large sums of money every year. More and more people join these online gaming sites. How can you as a player be certain that your opponents are playing fair? The project that was done at KTH investigates how programs on the user’s computer can be exploited to gain advantages in online games. Only memory injection will be examined in this purpose. Different techniques as well as suggestions on how application security can be improved will be presented in this report. PokerStat is a program developed to demonstrative purpose to show how memory injection can be used to exploit a poker client. PokerStat calculates the probability of receiving different poker hands whilst in the middle of an active hand. It shows the importance of deciding exactly what information should be stored in the memory of an application. A survey conducted during this project showed that the majority of subjects didn’t think that use of PokerStat should be classified as cheating. Despite that, the survey also shows that a majority of people does not want the functionality of PokerStat available to everyone in the poker client. The result of the survey shows that PokerStat gives an advantage to the user that people don’t want available to all users but the advantage is not big enough to be classified as cheating.

Företaget Burger Time Sweden AB gav uppdraget att utveckla en intern hemsida med ett program där man som anställd kan se ett arbetsschema och även på ett bekvämt sätt kunna meddela arbetsgivaren om arbetstiderna inte passar. Arbetsgivaren ville även ha en kundhemsida med möjlighet att kunna redigera såsom schemat, menyer och mycket mer utan tidigare kunskaper inom programmering. Kundhemsidan önskas visa olika menyer och kampanjer som restaurangen erbjuder. Alla krav som arbetsgivaren efterfrågade utfördes och utöver det framförde vi ytterligare några funktioner som sedan implementerades. Genom en inloggningsfunktion och användare med olika rättigheter kan man skilja på anställda och arbetsgivare. På så sätt varierar tillgången på funktioner beroende på vem som är inloggad. Exempelvis kan de anställda se schemat online medan arbetsgivaren även kan redigera det. Arbetsgivaren har tillgång till all funktionalitet på internhemsidan och har därmed möjlighet att redigera menyer och erbjudanden på kundhemsidan när han själv tänkt sig utan att behöva kontakta oss examensarbetare. Vi har alltså utvecklat en produkt som kan tänkas vara intressant för småföretagare i olika branscher eftersom funktionaliteten stödjer det. De flesta kan tänkas behöva en plattform online för schema till de anställda, kontaktuppgifter, priser och information om lediga jobb. / The company Burger Time Sweden AB gave us the assignment to develop an application where, as a employee, you can see the schedule and in a comfortable way notify the manager if a shift doesn't fit. The manager also wanted a customer website with editing possibilities that doesn't require any previous knowledge in programming. The costumer website should show different kinds of menus and campaigns that the restaurant has to offer. All the things that were assigned to do were completed. Some few extra functions were created that are now up and running. With a login function and the possibility to assign different rights to users the system can easily tell employees apart from managers. In that way the access to functions changes depending on who's logged in. For example the employees can see the schedule online whilst the manager also can edit it. The manager has access to all the functionalities on the internal webpage and therefore also has the possibility to edit the menus and offers on the costumer webpage whenever he wants to, without having to contact the creators of the program. In other words the developed product could be interesting for other small businesses in different types of trades, since the functionality supports it. Most of these businesses might need an online platform for employee schedules, contact information, prices and information about available jobs.

Nya moderna plattformar utvecklas med tiden, och redan existerande system flyttar till de nya plattformarna för att utnyttja deras fördelar. I den här studien har vi arbetat med att byta plattform för ett system beståendes av en webapplikation och en mobilapplikation med en gemensam databas av typen Microsoft SQL server 2012. Det som har undersökts är ifall webapplikationen skulle kunna flyttas till Microsofts molnplattform Windows Azure. Samtidigt har vi undersökt ifall det går att överföra design och funktionalitet ifrån mobilapplikationen utvecklad på iOS till plattformen Windows Phone 8. Arbetet med att flytta databasen löstes genom att hitta ett program som på ett strukturerat sätt kunde återskapa databasen på Windows Azure. Detta gjorde vi med programmet Microsoft SQL Server Management Studio. Arbetet med applikationen bestod av att studera designen och funktionaliteten i iOSapplikationen och försöka återskapa den på den nya plattformen. Det program som vi använde oss av var Windows Visual Studio 2012 och dess tilläggsprogram Windows Phone 8 Software Development Kit (SDK). Flytten av kundhanteringssystemet bestod av att lösa paketproblem på Windows Azure samt att publicera kundhanteringssystemet på Windows Azure. Till detta användes Visual Studio 2012 samt Microsoft Web Matrix. Resultatet har blivit en prototyp av den gamla applikationen på plattformen Windows Phone 8 samt en publicering av kundhanteringssystemet och databasen till Windows Azure. Det flyttade systemets olika delar kommer båda åt databasen, men på grund av tidsbrist har inget systemtest kunnat göras. Detta har lett till att vi inte har kunnat hitta och analysera de skillnader som existerade mellan det gamla systemet och det flyttade systemet. / New modern platforms are developed with time, and already existing systems migrate to the new latforms to use their advantages. In this project we have worked on changing the platform for a iven system consisting of a Customer Relationship Management system (CRM system) and a mobile application with a shared Microsoft SQL Server 2012 database. What has been evaluated s if it was possible to move the CRM system to the Microsoft cloud platform Windows Azure. Meanwhile, a study was done on the viability to transfer the iOS applications design and functionality to the Windows Phone 8 platform. The task of moving the database was solved by finding a program that, in a structured way, could recreate the database on Windows Azure. This was done with the program Microsoft SQL Server anagement Studio. The work involving the application consisted of studying the design and functionality of the iOSapplication and partially recreate it on the new platform. The program we used was Windows isual Studio 2012 and its extension Windows Phone 8 SDK. The transfer of the CRM system consisted of solving the package issues that created problems on indows Azure and publishing it on a Windows Azure website. For this we used Visual Studio 012 and Microsoft Web Matrix. The result was a prototype of the wanted application and the publishing of the CRM website and the database on Windows Azure. The new system worked together in a functional way, but due to lack of time a system test was not done to see if the new system had the same functionality as the original system.

In video streaming it is important that the video stream reaches the users in time, and without errors. To retransmit lost packets in a largescale multimedia video transmission is often unfeasible because of the retransmission delay. Because of that errors require either costly retransmissions or causes a downgrade of performance for the receiving user, an important goal is to minimize the number of errors that occurs when transmitting data during video streaming through a wireless channel. In this paper an adaptation-algorithm is proposed, which adapts itself in such away that the receivers of e.g. the broadcast will receive enough packets in order to be able to FEC-decode the received data in low- as well as high loss-scenarios. The algorithm adapts itself by changing the rate of FEC-encoded redundant packets based on the current packet-loss-rate of the channel, with the aim of optimizing the bandwidth-usage and providing the receiver with playable data meeting deadlines. It adds an additional self-adaptive amount of FEC-encoded redundant packets for each FEC-encoded-session in order to guarantee the ability of the receiver to FEC-decode the data and play the media, even under the conditions in which the inteference-level of the channel increases during the transmission of each such session. Simulations demonstrate that in a wireless channel with a packet loss rate of 10%, using 1000 source packets per FEC-encoded unit, 12.6% redundant packets are required in order to ensure a FEC-decoding-failure probability < 1/1000 . / När man streamar video är det viktigt att videostreamen når användarna i tid och utan fel. Att återsända förlorade paket i en storskalig överföring av video är ofta olämpligt p.g.a. den fördröjning som återsändning av paket orsakar. Eftersom att fel kräver antingen kostsamma återsändningar eller orsakar en försämring av prestandan för den mottagande användaren, är det ett viktigt mål att minimera antalet fel som uppstår när man överför data genom en trådlös nätverkskanal. I denna thesis presenteras en anpassningsalgoritm, som anpassar sig själv på sådant sätt att mottagarna av t.ex. broadcast kommer att motta tillräckligt många paket för att kunna utföra en FEC-dekodning av datan i scenarion med både små och stora paketförluster. Algoritmen anpassar sig själv genom att ändra andelen av FEC-kodade redundanta paket baserat på kanalens nuvarande andel av paketförluster, med målet att optimera användandet av bandbredd och att förse mottagaren med uppspelbar data inom deadlines. Andelen FEC-kodade redundanta paket är beräknade så att datan ska kunna dekodas och spelas upp även under de förhållanden där störningsnivån i kanalen ökar under överföringen av datan. Simuleringar, gjorda i en trådlös kanal i vilken 10% av paketen förloras, visar att det med 1000 paket av den ursprungliga datan krävs ytterligare 12.6% redundanta paket per FEC-kodad enhet för att uppnå en sannolikhet för ett misslyckande av FEC-dekodningen < 1/1000 .

In this work we explore the new DNA sensing and trapping possibilities offered by a plasmonic nanopore. This new device combines the sensing capability of solid state nanopores with the effects arising from the collective oscillation of electrons in gold nanoparticles (plasmons). The device consists in a nanopore drilled in a silicon nitride membrane and triangular gold nanoparticles in a bowtie configuration co-aligned with the pore. We exploit plasmonic heating to characterise the metallic nanostructures and we study its effect on pore stability. These observations allow us to optimise the sample characteristics and the experimental conditions for DNA translocation experiments. In this regard, we focus on how plasmonic excitation influences the depth of a current blockade, evaluating the contribution of the shift of the resonance spectrum due to the presence of a molecule in the surroundings of the particles. We also forwarded the hypothesis of a contribution of thermophoretic forces, due to high local heating induced by the plasmonic structures. Heating and thermophoretic forces could also influence the increase in translocation frequency, observed in our experiments upon plasmonic excitation. This increase is probably due to changes in the buffer viscosity which affects the magnitude of the pore’s capture radius of the DNA molecules. We also explore the possibility of controlling the motion of DNA inside the pore by means of optical trapping. This principle is based on utilising optical forces from the strong gradient of the evanescent electric field that is created, upon illumination, from the surface of the metallic nanoparticles to few nanometers away. From preliminary molecular dynamics simulations, we expect the optical force to be able to overcome the driving electric force at experimentally relevant excitation powers. Indeed, for plasmonic excitation around laser power 10 mW and above, we observed long (> 1s) and multilevel events, which indicate successful plasmonic trapping of DNA in nanopore. However we note that such long events were often present also after turning off the plasmonic excitation, likely due to permanent sticking of to the pore/bowtie. Although we need to solve some issues of sticking of molecules and to perform more systematic experiments before drawing any conclusion regarding trapping, the results are promising and indicate that plasmonic nanopores may enable light-controlled trapping of DNA in nanopores.

The attention for rural coverage was increasing in media. The need for faster mobile internet speeds was growing, not least for the forest industry. This industry was becoming more updated and sufficient wireless communication could make it more efficient. Additionally, rural coverage could be used by people living in remote areas, such as farmers, and tourist organizations as well. In order to enhance the rural coverage, firstly the existing coverage had to be determined. There were coverage maps done by the operators; however people were not satisfied with them since the stated coverage not always was available. Hence, one goal of this study was to verify how much coverage that was available for the forest industry. The other goals were to verify this coverage and suggest how to improve it. Coverage maps from operators were compared with harvesting locations for the forest industry. This would give an illustration of how the situation looked like, according to the available coverage maps. In addition a couple of methods that verified the coverage maps were done. These methods were then backed up by theoretical calculations. The results showed that the best coverage according to the operator coverage maps was given by Net1. Furthermore the best verification of coverage is given by Ascom Tems products, if several details are wanted. However, if a budget solution would be sought, less advanced applications could be enough.

Nowadays the traffic demand grows fast that requires careful chosen deployment strategy to increase capacity, but save investments. Another important subject is to save a power consumed mostly by base station itself and its backhaul network. So, what type of base stations must be chosen, what spectrum characteristics it has and what backhaul link is connected to it. All this aspects requires different approaches, as they have different capacity and cover characteristics. The motivation is to compare the solutions using different base station types and various backhaul solutions. The question if the spectral efficiency allows to increase the traffic throughput, it would decrease or increase power consumption and cost. The modern technologies propose several options, ones of them are macro cellar and femtocell network. The macro cell has a great ability to cover a big area, while the femtocell has a good capacity possibilities. Moreover, femtocell partially are paid and installed by end-users that decrease the installation and electricity cost for operators. However, operator can reuse existed sites which decrease investment cost of macrocellular network. So, the first milestone is to find the way how to fairly compare two different types of technologies. In this thesis the proposed scenario is composed in a very careful way to predict demand types, base stations possibilities and characteristics as well as the backhaul architecture. Then the more accurate model to deploy a femtocellular network has been described in detail. The more detailed cost strategy is introduced for backhaul solutions and described in detail. The power consumption calculations has been described in more clear way, to show the range of metrics, what value should it has: negative or positive. Some formulas is remade to reach more correct results. Another milestone is to bring all parameters to unique format that has been done to achieve right results. In the microwave backhaul solution, the topology case added and carefully described, because every topology case requires different formulas, in this thesis, the calculation steps for star and ring topologies presented. Steps how to calculate the base station radius depends on power characteristics of base station is provided. Since this thesis introduces improvements in several points, It is good guide to keep in track the received results and control the calculation process.

This report presents a method to recover from faults detected by hardware in numerical iterative solvers. By exploiting redundancy inherent to an iterative solver instead of adding redundancy, we can interpolate lost data and thus devise an exact recovery scheme, which does not compromise mathematical convergence properties of the solver as methods based on restart would do. We rely on a task-based programming model to overlap the furthering of normal computation and recovery. Results show a low overhead with no fault injection, that could be reduced even more with better lower-level support for application level resilience, and exceptional performance when faults are injected, even under with extremely high fault injection rates. This is a huge improvement on checkpoint-based recovery methods, and progress towards the goal of resilient and asynchronous HPC methods for exascale computing. / Den här rapporten presenterar en metod för återhämtning från fel detekterad av maskinvara, i numeriska iterativa lösare. Genom att utnyttja den redundans som finns i dessa lösare i stället för att lägga till redundans, kan vi interpolera förlorad data och därmed utforma ett exakt återvinningssystem utan checkpoints-kostnader. Exakta återvinningssystem äventyrar inte lösarnas matematiska konvergensegenskaper, vilket metoder baserade på återstart skulle göra. Vi användar en task-baserad programmeringsmodell för att överlappa framsteg av normala beräkninger och återhämtning. Resultaten uppvisar en låg kostnad utan förekomst av fel, vilka kan minskas ännu mer med bättre stöd från lägre nivåer för applikationsnivå-feltolerans, och exceptionell prestanda när fel injiceras, även under extremt höga felinjiceringsfrekvenser. Detta är en enorm förbättring jämförd med checkpoint-baserade återhämtningsmetoder, och ett framsteg mot målet för motståndskraftiga och asynkrona HPC metoder för exascale.

Examensarbetets mål är att ge ett förslag på en lämplig typ av batteri för explosionsfarlig miljö. Efter det skall en passande laddare dimensioneras och konstrueras. Ett passande energiöverföringssystem skall föreslås och i mån av tiden dimensioneras för att kunna försörja en robot med energi vid laddning i brandfarliga miljöer. För att uppnå målen behövde man gå igenom relevanta standarder för att reda ut vad som gäller batterier och energiöverföring i brandfarliga miljöer. Några tidigare studier har studerats igenom för att få inblick och förståelse i vad som gäller för både batterier och energiöverföring och vad som är lämpligt för användning i de miljöerna. En mikrokontrollerstyrd och anpassad laddare hade konstruerats till det valda batteriet. Kraftdelar av laddare hade körts på labbänken. Ett trådlöst energiöverföringssystem är föreslagen men inte dimensionerad i detta examensarbete. / The thesis aims to provide a proposal for a suitable type of battery for ATEX classified environment. After that, a compatible charger designed and constructed. A fitting power transmission system shall be proposed and the extent of the time dimensioned to be able to provide a robot with energy when charging in hazardous locations. To achieve the goals needed to go through the relevant ATEX standards to sort out what applies batteries and energy transfer in flammable environments. Some earlier studies had studied to gain insight and understanding of what applies to both batteries and energy transmission and what is suitable for use in these environments. A microcontroller controlled and customized charger had been constructed to the selected battery. Power Parts of the charger had been run on the lab bench. A wireless energy transfer system is proposed but not designed in this thesis.