Galileo är ett Global Navigation Satellite System (GNSS) som används för positionering. Förutom Galileo finns även Global Positioning System (GPS) och Globalnaya Navigatsionnaya Sputnikovaya Sistema (GLONASS) vilka är de idag enda fullt operativa systemen. Galileo som är under utveckling har i april år 2020 26 satelliter i bruk och förväntas vara fullt operativt under 2020 med en konstellation av 30 satelliter. Vid statisk mätning används GNSS-teknik där minst två mottagare samlar observationer samtidigt under långa sessioner där positionen erhålls med efterberäkning. Syftet med denna studie var att undersöka huruvida Galileo genom statisk mätning kan tillföra lägre mätosäkerhet i olika GNSS-konstellationer tillsammans med GPS och GLONASS. Tvångscentrering utfördes över två kända positioner med mätning över två dagar på totalt 12 timmar. I efterberäkningen delades sessionerna in i 45 minuters observationer över fyra sessioner. Fem olika konstellationer av GNSS jämfördes: GPS, GPS och Galileo, GPS och GLONASS, Galileo och till sist där alla tre system användes ihop. Resultatet visade på en god precision med en lägesosäkerhet något större än förväntat. Session 1 fick högst värde på 4,7 cm från stompunkten. Lägst värde fick session 4 på 1,1 cm. Standardosäkerheten var däremot låg för alla konstellationer i sessionerna. Slutsatsen är att Galileo och GPS fick som enskilda konstellationer ett likvärdigt resultat för standardosäkerheten med statisk mätning. I gemensamma GNSS-konstellationer förbättras mätosäkerheter och indikerar även att användning av Galileo ger en förbättring i kombination med GPS och GLONASS. / Galileo is a new Global Navigation Satellite System (GNSS) which is still under development and is expected to be fully operational in 2020. Besides Galileo there are also the Global Positioning System (GPS) and the Globalnaya Navigatsionnaya Sputnikovaya Sistema (GLONASS) which are the only fully operational systems as of April 2020. The purpose of this study was to evaluate whether Galileo can provide better measurement accuracy in different GNSS constellations together with GPS and GLONASS through static surveying. Many scientific studies of Galileo GNSS have been done recently, and since additional satellites have become available the accuracy of the system has been increasing. This study uses static surveying method in order to evaluate Galileo’s positioning accuracy. Measurements over two known positions was done with post calculations to remove sources of error. The study shows that Galileo and GPS obtained as individual constellations an equivalent result, and in joint GNSS constellations Galileo shows improvements in combination with GPS and GLONASS.

In lighting design, several different variables are measured, such as illuminance. Measuring these values requires different types of measuring instruments, either static measuring instruments or portable measuring instruments. Depending on the make, the same type of measurement can be measured in different ways. A static measuring instrument is usually measured one time at a specific location, while a portable measuring instrument can, for example, measure every minute or every ten minutes for an extended period. With constant research and technological development, the measurement of lighting variables has become more relevant. It is problematic to conduct experiments with a lack of consistent and accurate methods when measuring light. It is important to have the right conditions for a measurement in order for the results to be of good quality. The purpose of this study is to investigate differences between different static and portable measuring instruments used to describe the exposed illuminance and the physical activity. This is done through a pilot study. The pilot study was conducted using an experimental quantitative method with two participants during one day in four different measurement occasions with six different measuring instruments, the measuring instruments being measured in vertical, horizontal and flexible positions. The analysis showed that the results largely depended on whether a static or portable measuring instrument was used. The results also showed that depending on what position the measuring instruments measure from, the results vary. Based on the results, the conclusion is that the closer to eye level one can get, the more relevant the results are. For further research, all the measuring instruments used in the study should be calibrated prior to implementation. For example, it is important to examine the sensitivity of the measuring instruments when measuring indoors and outdoors. More participants, more measurements and more contexts would have been preferable for further research.

This Master Thesis, written in collaboration with CorPower Ocean, serves as the finalization of the author’s master degree education at KTH (Royal Institute of Technology) Stockholm. The purpose has been to characterize the Cascade gearbox which is used to convert vertical motion induced by waves to rotational motion which powers generators in the company’s future wave energy power plant. The purpose was also to suggest future improvements and shed light on any problems discovered. The method for characterizing the Cascade gearbox was to conduct physical measurements of the load sharing in the inherently overdetermined geometrical design. These data were then used to calibrate a static as well as a dynamic model also developed for this thesis. Focus has been on determining that the novel load sharing method is sufficient and that no gear takes more than the 2,5% overload during max load the gearbox is dimensioned for at any time. Also included in the thesis is an analysis of the tolerances effect on the performance of the Cascade gearbox. Results showed that the current design perform within the expected dimensioning limits. However some unexpected characteristics were discovered after analysis of the results. Because of deliberate geometric decisions half of the gears trail behind initially in one direction causing uneven load sharing and unwanted lateral forces on the rack. Also discovered was the importance of equal stiffness of the flex units, used to divide the load evenly between the gears, since the load sharing factor converges towards values directly proportional to the stiffness ratios in between them. As a conclusion it can be said that although the current design is sufficient, there is still room for improvements which could enhance life expectancy as well as load sharing performance of the Cascade gearbox. / Detta examensarbete utfört i samarbete med CorPower Ocean, är det slutgiltiga steget i författarens utbildning på masternivå på KTH (Kungliga Tekniska Högskolan) Stockholm. Syftet med arbetet är att karakterisera en kaskadväxellåda som används för att omvandla vertikal rörelse från vågor till rotation som driver generatorer i företagets framtida vågkraftverk samt att utifrån resultat föreslå möjliga förbättringar och belysa eventuella problem. Den metod som använts för att karakterisera kaskadväxellådan var att via fysiska mätningar, på den testrigg placerad på KTH (Kungliga Tekniska Högskolan) i Stockholm, erhålla data för lastfördelningen i den geometriskt överbestämda konstruktionen. Dessa data användes sedan för att kalibrera en statisk och en dynamisk modell som också utvecklades för det här projektet. Huvudfokus för arbetet har legat i att ta reda på om den konstruktion som används för att fördela lasten mellan kugghjulen fungerar tillfredställande samt att säkerställa att inget kugghjul tar mer än de 2,5% överlast vid fullast växellådan är dimensionerad för vid något tillfälle. Examensarbetet inkluderar även feltoleransers inverkan på lastfördelningen i kaskadväxeln. Resultaten visade att den nuvarande konstruktionen presterar inom de specificerade dimensioneringsintervallen. Några oväntade karaktärsdrag upptäckdes dock vid analys av resultaten. På grund av en avsiktlig geometrisk oregelbundenhet släpade hälften av kugghjulen efter åt ena hållet vilket i sin tur resulterade i en ojämn lastfördelning och oönskade sidokrafter på kuggracken. Flexenheterna som används för att fördela lasten likvärdigt mellan kugghjulen skilde sig åt i styvhet. Den inverkan spridningen av dessa har på lastfördelningen belystes också eftersom lastfördelningen konvergerar mot värden direkt proportionella mot styvhetsförhållandet mellan dem. Slutsatsen från examensarbetet är att den nuvarande konstruktionen, även om den fungerar tillfredställande, lämnar utrymme för förbättringar som potentiellt kan förbättra både livslängd och lastfördelningsprestanda.

Control flow graphs (CFGs) are abstract program models that preserve the control flow information. They have been widely utilized for many static analyses in the past decades. Unfortunately, previous studies about the CFG construction from modern languages, such as Java, have either neglected advanced features that influence the control flow, or do not provide a correctness argument. This is a bearable issue for some program analyses, but not for formal methods, where the soundness of CFGs is a mandatory condition for the verification of safety-critical properties. Moreover, when developing open systems, i.e., systems in which at least one component is missing, one may want to extract CFGs to verify the available components. Soundness is even harder to achieve in this scenario, because of the unknown inter-dependencies involving missing components. In this work we present two variants of a CFG extraction algorithm from Java bytecode considering precise exceptional flow, which are sound w.r.t to the JVM behavior. The first algorithm extracts CFGs from fully-provided (closed) programs only. It proceeds in two phases. Initially the Java bytecode is translated into a stack-less intermediate representation named BIR, which provides explicit representation of exceptions, and is more compact than the original bytecode. Next, we define the transformation from BIR to CFGs, which, among other features, considers the propagation of uncaught exceptions within method calls. We then establish its correctness: the behavior of the extracted CFGs is shown to be a sound over-approximation of the behavior of the original programs. Thus, temporal safety properties that hold for the CFGs also hold for the program. We prove this by suitably combining the properties of the two transformations with those of a previous idealized CFG extraction algorithm, whose correctness has been proven directly. The second variant of the algorithm is defined for open systems. We generalize the extraction algorithm for closed systems for a modular set-up, and resolve inter-dependencies involving missing components by using user-provided interfaces. We establish its correctness by defining a refinement relation between open systems, which constrains the instantiation of missing components. We prove that if the relation holds, then the CFGs extracted from the components of the original open system are sound over-approximations of the CFGs for the same components in the refined system. Thus, temporal safety properties that hold for an open system also hold for closed systems that refine it. We have implemented both algorithms as the ConFlEx tool. It uses Sawja, an external library for the static analysis of Java bytecode, to transform bytecode into BIR, and to resolve virtual method calls. We have extended Sawja to support open systems, and improved its exception type analysis. Experimental results have shown that the algorithm for closed systems generates more precise CFGs than the modular algorithm. This was expected, due to the heavy over-approximations the latter has to perform to be sound. Also, both algorithms are linear in the number of bytecode instructions. Therefore, ConFlEx is efficient for the extraction of CFGs from either open, or closed Java bytecode programs. / <p>QC 20121122</p>

Surfactants self-assemble into aggregates above a certain concentration. In this work mixtures of the cationic surfactant cetyltrimetylammonium bromide (CTAB) and the anionic surfactant sodium octyl sulfate (SOS) were investigated systematically. The measurements were accomplished by combining the two complimentary techniques static light scattering (SLS) and cryo-transmission electron microscopy (CRYO-TEM). It was found that CTAB-rich samples contain large threadlike micelles rather close to mole fractions where vesicles start to form. The mole fraction x of the surfactant in excess in the aggregates was calculated and it was found that it differs a lot from the mole fraction in the bulk, and the transition from micelles to vesicles occurs when x is about 0.7. In the SOS-rich samples small globular micelles were observed that transform into vesicles upon dilution. Some of the samples rich in SOS were found to contain open vesicles with CRYO-TEM and the reasons for this behavior have been discussed. One question that needs to be further investigated is whether or not these structures are the result of some kind of distortion of the equilibrium process during sample preparation in connection with CRYO-TEM measurements. In most cases the two methods showed consistent results and trends, but for some samples differences could be observed.

Although high strength steels represent yield strength up to 1300 MPa, welded structures reveal lowerstrength values. The strongest commercially available electrode provides the yield strength of about900 MPa. Therefore, in welded steels with strength above this type of filler metal, achieving anacceptable global strength is a crucial issue. In this master thesis, affects of different welding procedures on static strength of welded jointsof Weldox 960 and Weldox 1100 steels, were studied. These steels are produced by SSAB inOxelösund. Meanwhile, finite element method analyses were applied in order to investigatethe static strength behavior of such weldments under uniaxial tension. The welding parameters which were selected as variables are:  Heat input Weld joint geometry Filler metal When weld metal is undermatching in strength levels than the base material, by applyingtension the soft weld metal begins to deform before parent metal. At that point thedeformation of resulted soft zone, including the weld metal and the heat affected zone, ishindered by high strength parent metal. Thus, uniaxial stress caused by uniaxial load isconverted to multiaxial stress. This conversion in tension results in increase in the staticstrength of weldment. The increase in strength is emphasized by increase in the width of thewelded joint while the thickness of the plate is kept as constant. After experiments and performing FEM studies, it was revealed that the static strength ofWeldox 960 welded joints approaches towards the tensile strength of parent metal by increasein the width of the weldment. In Weldox 1100 joints; a slight increase in tensile properties ofthe weldments, when the width of the sample increases, was observed.

Sandwich plates and layered composites are common in many structural applications because of their combination of high stiffness and low weight. These plates combine top and bottom layers of high Young's modulus with intermediate layers of material carrying predominantly shear loads. Finite elements developed for the analysis of sandwich plates need to accurately model transverse shear stresses through the plate thickness. This study was inspired by an Office of Naval Research project to investigate the suitability of steel sandwich plates as ship hulls. A finite element implementation based on a third-order shear deformation element was used in a standard finite element program to model transverse shear stresses in a simply supported plate. Four elements based on third-order theory are developed and tested. Using static condensation to reduce the number of degrees of freedom required by a third-order plate element does not preserve the element's accuracy in either displacements or stresses, and stresses do not converge with refinement of the mesh. For the thin isotropic plate case, some condensed elements give reasonable displacement and stress results, but only for certain choices of mesh and the element is less versatile than one based on first order plate theory. None of the condensed elements give good results for composite plates of any thickness. / Master of Science

Embedded systems are a crucial part of modern vehicles today and are used widely by the automotive industry to control safety-critical functions. To verify that the software will work correctly, formal verification can be used to prove that the code will always behave correctly according to some specification. This report will look into how to formulate the specification in such a way that it is easy to use, consistent and can be used efficiently for code verification. Two different models are looked into in the report, and applied to real automotive embedded code. From this, conclusions are made about the different models. / Inbäddade system är en viktig del av moderna motorfordon idag,  och används av stora delar av fordonsindustrin för att kontrollera säkerhetskritiska funktioner. För att verifiera att mjukvaran fungerar korrent, kan man använda formell verifiering för att bevisa att koden alltid fungerar korrekt enligt en specifikation. Den här rapporten kommer att studera hur man bäst formulerar en sådan specifikation så att den är lätt att använda, konsekvent och kan användas effektivt för kodverifiering. Två olika modeller används i rapporten, och appliceras till en riktig kodmodul från fordonsindustrin. Från detta görs sedan slutsatser om de olika modellerna.

Technical debt is a well known term within software development, but has not yet been implemented outside of software development. Because of this, there is no knowledge whether that is possible or not. This thesis investigates how technical debt can be extended to and be identified within a software system for handling Product Lifecycle Management. The purpose of the thesis is to present a prototype, called the ITS-prototype, which shows that it is possible to identify technical debt within Product Lifecycle Management. The thesis has qualitative characteristics and were conducted as a case study. In order to verify that the implementation is correct, two evaluation criterias were established. The first criteria, measuring the degree of coverage, saying that the ITS-prototype should be able to identify 100% of the technical debt defined by each rule. The second criteria consists of an interview with a technical expert on Product Lifecycle Management where the prototype's underlying method is evaluated. The ITS-prototype together with the results of the evaluation shows that technical debt is possible to be implemented and identified in a software system for handling Product Lifecycle Management. The rule-driven implementation that is used, has shown effective and the authors suggests that the development of the ITS-prototype continues in order to better use conveniences that exist within a Product Lifecycle Management-system. / Teknisk skuld är ett vedertaget begrepp inom mjukvaruutveckling men har ännu inte implementerats utanför mjukvara. Således finns det ingen kunskap om huruvida det är praktiskt möjligt att göra detta eller inte. I detta arbete undersöktes om konceptet teknisk skuld kan implementeras i ett mjukvarusystem för hantering av Product Lifecycle Management. Syftet med arbetet är att visa att teknisk skuld kan implementeras inom Product Lifecycle Management genom att presentera en prototyp för identifiering av teknisk skuld inom Product Lifecycle Management, kallad ITS-prototypen. Arbetet är av kvalitativ karaktär och genomfördes som en fallstudie. För att verifiera att implementationen är korrekt upprättades två utvärderingskriterier. Det första mäter prototypens täckningsgrad och säger att ITS-prototypen ska kunna identifiera 100% teknisk skuld definierad av varje regel. Det andra kriteriet består av en utvärderingsintervju med en teknisk expert på Product Lifecycle Management, där prototypens underliggande metod utvärderas. ITS-prototypen tillsammans med resultaten av utvärderingen visar att teknisk skuld är möjlig att implementera i ett mjukvarusystem för hantering av Product Lifecycle Management. Den regeldrivna implementation som använts i ITS-prototypen är effektiv och författarna föreslår att utvecklandet av prototypen fortsätter för att bättre kunna nyttja fördelar i ett PLM-system.

Security testing is a widely applied measure to evaluate and improve software security by identifying vulnerabilities and ensuring security requirements related to properties like confidentiality, integrity, and availability. A confidentiality policy guarantees that attackers will not be able to expose secret information. In the context of software programs, the output that attackers observe will not carry any information about the confidential input information. Integrity is the dual of confidentiality, i.e., unauthorized and untrusted data provided to the system will not affect or modify the system’s data. Availability means that systems must be available at a reasonable time. Information flow control is a mechanism to enforce confidentiality and integrity. An accurate security assessment is critical in an age when the open nature of modern software-based systems makes them vulnerable to exploitation. Security testing that verifies and validates software systems is prone to false positives, false negatives, and other such errors, requiring more resilient tools to provide an efficient way to evaluate the threats and vulnerabilities of a given system. Therefore, the newly developed tool Reax controls information flow in Java programs by synthesizing conditions under which a method or an application is secure. Reax is a command-line application, and it is hard to be used by developers. This project has its primary goal to integrate Reax by introducing a plugin for Java IDEs to perform an advanced analysis of security flaws. Specifically, by design, a graphical plugin performs advanced security analysis that detects and reacts directly to security flaws within the graphical widget toolkit environment (SWT). The project proposed a new algorithm to find the root cause of security violations through a graphical interface as a second important goal. As a result, developers will be able to detect security violations and fix their code during the implementation phase, reducing costs.