京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第18227号 / 工博第3819号 / 新制||工||1585(附属図書館) / 31085 / 京都大学大学院工学研究科電気工学専攻 / (主査)教授 小林 哲生, 教授 引原 隆士, 教授 小山田 耕二 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM

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The concept of cloud computing describes a business model in which multiple service providers pool their resources to serve customers online. The ability to pool and assign resources as needed, to deliver services based on accurate usage metrics, to rapidly scale up or down, to deliver services on demand, and to give customers access from any location are just a few of the many benefits of cloud computing. Many organizations and people are interested in cloud computing, but they are also apprehensive of it because of concerns about data security, data availability, and other issues. In this thesis, the topic of vendor lock-in in cloud computing is investigated, as is the role that proprietary technology, contract terms, and network effects play in maintaining this issue in Swedish organizations. The research investigates the various ways in which these characteristics restrict businesses' ability to be flexible and independent by creating barriers that prevent them from switching cloud providers. The thesis addresses these concerns by presenting three potential solutions to the problem of vendor lock-in. These solutions include the utilization of open-source technology, the implementation of a multi-cloud, and an exit strategy. This thesis intends to assist organizations in controlling the risks that relate to cloud computing and vendor lock-in by giving guidance on the subject and providing solutions to the issues that have been identified.

IoT devices have become more common in our everyday lives as they provide more useful features than traditional devices. One such device is the smart door lock, which enables homeowners to grant access on a user-specified level through digital keys and remote operation. However, as smart locks are meant to protect everything we own, they become an attractive target for attackers. This thesis evaluates the Yale Linus and Gimdow smart lock systems through a comprehensive security examination. In order to provide insight into the IT security of common smart locks on the market today and whether or not the companies behind the locks researched have implemented mitigations towards common attacks on smart locks found in earlier research. In doing so, Gimdow proved to lack basic security measures as an attacker could easily get unauthorized access. The Yale Linus system was deemed to have sufficient IT security as no immediate vulnerabilities were found. / IoT-enheter har blivit vanligare i vår vardag eftersom de tillhandahåller fler funktioner än traditionella enheter. En av dessa enheter är det smarta dörrlåset. Låset gör det möjligt för husägare att, på en användarspecificerad nivå, ge åtkomst till hushållet genom digitala nycklar och fjärrstyrning. Men eftersom smarta lås är avsedda att skydda allt vi äger, blir de ett attraktivt mål för angripare. Denna avhandling utvärderade två smarta låssystem av Yale Linus och Gimdow genom en omfattande säkerhetsundersökning. Målet var att ge insikt i IT-säkerheten för smarta lås på marknaden idag, samt kolla ifall låsföretagena bakom de valda låsen har tagit tidigare forskning angående attacker på smart lås i åtanke. I den här studien visade det sig att Gimdow saknar grundläggande säkerhetsåtgärder vilket tillåter en angripare att lätt få obehörig åtkomst. Yale Linus-systemet ansågs ha tillräcklig IT-säkerhet eftersom inga omedelbara sårbarheter kunde hittas.

I characterize the behavior of microcantilever arrays which utilize the in-plane photonic transduction that I've previously developed and evaluate the performance of the microcantilever arrays in simple sensing scenarios with integrated microfluidics. First the thermal responses of microcantilevers with a variety of patterns of deposited gold films are compared. Using a scanning electron microscope, I observe the deflection thermal sensitivities of 300 µm long microcantilevers to be -170.82 nm/K for a full gold coating and -1.93 nm/K for no gold coating. Using the photonic transduction method I measure a thermal sensitivity of -1.46 nm/K for a microcantilever array with no gold. A microcantilever array integrated with microfluidics is exposed to a solution of bovine serum albumin (BSA) followed by solutions of various pH's. In all cases I observe a previously unreported transient deflection response. We find that the transient response is due to temporary nonuniform concentration distributions. In response to nonspecific binding of BSA, I observe a transient surface stress of -0.23 mN/m that agrees well with the -0.225 mN/m predicted by simulations. We hypothesize that the deflection response to pH changes is due to stress generated by conformational changes of bound BSA.The deflection response of an integrated microcantilever array to different types of flow and different flow rates is observed. Simulations of the deflection response match well with experimental results but disagree at higher flow rates. For flow rates greater than 200 µL/min, the limitation of the differential signal's dynamic range becomes apparent. We then investigate flow driven by an on-chip reciprocating reservoir pump. We demonstrate that it is possible to use the reciprocating pump to achieve high flow rates while making deflection measurements in-between reservoir actuations. Investigations of the microcantilever array noise show that flicker noise dominates below 10 Hz, while above 10 Hz, readout noise dominates. A minimum deflection noise density of 15 pW/√Hz is achieved. To improve the signal-to-noise ratio I develop algorithms for a digital lock-in amplifier with a digital phase-lock loop. In simulation the lock-in amplifier is able to improve the SNR by up to a factor of 6000, and self-lock to a noisy carrier signal without an external reference signal.

Automotive development has always been need-based and the product of today is an evolutionover several decades and a diversied technology application to deliver better products to theend users. Steady increase in the deployment of on-board electronics and software is characterizedby the demand and stringent regulations. Today, almost every function on-board a modernvehicle is either monitored or controlled electronically.One such specic demand for AB Volvo arose out of construction trucks in the US market. Usersseldom have/had a view of the operational boundaries of the drivetrain components, resultingin inappropriate use causing damage, poor traction and steering performance. Also, AB Volvo'sstand-alone traction assistance functions were not suciently capable to handle the vehicle useconditions. Hence, the goal was set to automate and synchronize the traction assistance devicesand software functions to improve the traction and steerability under a variety of road conditions.The rst steps in this thesis involved understanding the drivetrain components from design andoperational boundary perspective. The function descriptions of the various traction softwarefunctions were reviewed and a development/integration plan drafted. A literature survey wascarried out seeking potential improvement in traction from dierential locking and also its eectson steerability. A benchmarking exercise was carried out to identify competitor and suppliertechnologies available for the traction device automation task.The focus was then shifted to developing and validating the traction controller in a simulationenvironment. Importance was given to modeling of drivetrain components and renement ofvehicle behavior to study and understand the eects of dierential locking and develop a differentiallock control strategy. The modeling also included creating dierent road segments toreplicate use environment and simulating vehicle performance in the same, to reduce test timeand costs. With well-correlated vehicle performance results, a dierential lock control strategywas developed and simulated to observe traction improvement. It was then implemented onan all-wheel drive construction truck using dSPACE Autobox to test, validate and rene thecontroller.Periodic test sessions carried out at Hallered proving ground, Sweden were important to re-ne the control strategy. Feedback from test drivers and inputs from cross-functional teamswere essential to develop a robust controller and the same was tested for vehicle suitability andrepeatability of results. When comparing with the existing traction software functions, the integrateddierential lock and transfer case lock controller showed signicantly better performanceunder most test conditions. Repeatable results proved the reliability of developed controller.The correlation between vehicle test scenarios and simulation environment results indicated theaccuracy of software models and control strategy, bi-directionally.Finally, the new traction assistance device controller function was demonstrated within ABVolvo to showcase the traction improvement and uncompromising steerability.

Concurrent programming is a form of computing, where several computations are executed in overlapping time periods. This can improve a system’s capability of handling growing amounts of work and execute faster on multicore processors. Lock is a usual tool used to ensure shared data is handled correctly. However, using locks could also have some performance disadvantages caused by its overhead and waiting time during high contention.The company FIS believes a lock-free implementation using atomic operations could improve ability to handle growing amount of work and speed of a component in their trading system. Hence, the aim of this study is to provide insight of how impactful lock-free programming could be. This was achieved by developing a new version of the component and comparing its performance with the original lock-based implementation. The new implementation was developed by eliminating locks in the component and replacing them with lockfree data structures. However, a lock was still needed in one of the data structures, making the new implementation only partially lock-free. Results from tests performed directly on the component showed that the partially lockfree version performed better in some areas and worse in other. Furthermore, the partially lock-free implementation performed better in isolated tests which were used to measure parts of the component where direct tests could not be performed. This gives a sign of that a general performance improvement was achieved by using lock-free programming in the provided component. / Concurrent programming är en form av programmering, där flera beräkningar exekveras i överlappande tidsperioder. Detta kan förbättra ett systems förmåga att hantera växande mängder av arbete, och dessutom kunna exekveras snabbare på flerkärniga processorer. Lås är ett vanligt verktyg som används för att säkerställa att data i delat minne hanteras korrekt. Användningen av lås kan dock påverka prestandan negativt. Detta är på grund av minimalkostnad som tillkommer vid användning av lås samt väntetid på låset som kan uppstå vid hög konkurrens.FIS anser att en låsfri implementation baserat på atomiska operationer skulle kunna förbättra förmågan att hantera växande mängd arbete och hastigheten på en komponent i sitt tradingsystem. Syftet med denna studie är därför att ge insikt om hur effektiva låsfria program kan vara. Detta uppnåddes genom att utveckla en ny version av komponenten och jämföra dess prestanda med den ursprungliga, låsbaserade, implementation. Den nya implementationen utvecklades genom att eliminera lås med hjälp av låsfria datastrukturer. Dock behövdes ett lås i en av datastrukturerna, vilket innebar att komponenten endast var delvis låsfri. Resultat från tester utförda direkt på komponenten visade att den delvis låsfria versionen presterade bättre på vissa områden och sämre i andra. I de isolerade testerna dock, som användes för att mäta delar av komponenten där direkta tester inte kunde utföras, presterade den delvis låsfria versionen bättre. Detta ger en indikation på att en generell prestandaförbättring för den tillhandahållna komponenten uppnåddes med hjälp av låsfri programmering.

This thesis contains the design and simulation test results for the implementation of a new all-wheel drive (AWD) torque vectoring (TV) control system. A separate algorithm using standard control methods is included in this study for a comparison. The proposed controller was designed to be applied to an AWD independent drive electric vehicle, however the main concepts can be re-purposed for other vehicle drive train configurations. The purpose of the control system is to assist the driver in achieving a desired vehicle trajectory whilst also maintaining stability and control of the vehicle. This is accomplished by measuring various real time parameters of the vehicle and using this information as feedback for the control system to act on. The focus of this thesis resides on the controller. Hence, this study assumes perfect observation of feedback parameters, therefore some uncertainties are not accounted for. Using feedback parameters, the control system will manage wheel slip whilst simultaneously generating a torque around the center of gravity of the vehicle by applying a torque differential between the left and right wheels. The proposed TV algorithm is simulated in MATLAB/Simulink along with another separate TV algorithm for comparison. Both algorithms are comprised of two main parts: a slip ratio controller applied to each wheel individually and stability controller that manages yaw rate and side slip of the vehicle. The new algorithm leverages the super twisting algorithm for the slip ratio controller and uses a fusion of a linear quadratic regulator with the integral term of a super twisting algorithm to implement the yaw rate and side slip controller. The other algorithm used for comparison derives its implementation for the slip ratio controller and yaw rate and side slip controllers from simple and standard first order sliding mode control methods. Both control algorithms were tested in three different main tests: anti-lock braking, sine dwell (SD) steering, and constant steering angle (CSA) tests. To increase the comprehensive nature of the study, the SD and CSA tests were simulated at 3 speeds (30,50, and 80 mph) and the steering angle parameter was varied from 2 to 24 degrees in increments of 2. The result of this study proves that the proposed controller is a feasible option for use in theory. Simulated results show advantages and disadvantages of the new controller with respect to the standard comparison controller. Both controllers are also shown to provide positive impacts on the vehicle response under most test conditions.

Smart home appliances and IoT devices in general are a fast growing market. Smart door locks are one type of device which is included in these categories. The smart door lock replaces a common deadbolt lock. In this study a smart door lock was penetration tested. The project started with a literature study, followed by a reconnaissance phase for gathering information about the smart door lock system. A threat model was created based on the findings during the reconnaissance phase and with the help of the STRIDE and DREAD frameworks. Penetration tests were chosen and conducted based on the threat model. The results of the penetration tests showed no major vulnerabilities, but a weakness in the communications between the mobile app and the server. / Smarta apparater och generellt enheter på sakernas internet är en snabbt växande marknad. Smarta dörrlås är en slags enhet som inkluderas i dessa kategorier. I den här studien penetrationstestades ett smart dörrlås. Projektet började med en litteraturstudie, följt av en spaningsfas för att samla in information om det smarta låssystemet. En hotmodell skapades baserad på fynden från spaningsfasen och med hjälp av ramverken STRIDE och DREAD. Penetrationstester valdes och genomfördes baserat på hotmodellen. Resultaten från penetrationstesterna visade inga större sårbarheter, men en svaghet i kommunikationen mellan mobilappen och värddatorn.