Det finns en stor efterfrågan på ökad mobilitet och effektivitet för höghastighetståg i världen. Resenärer vill så snabbt och smidigt som möjligt anlända till sina destinationer. För att uppfylla dessa krav krävs en förbättring av restiderna mellan järnvägsstationer. Detta kan åtgärdas genom en ökning av hastigheter på höghastighetslinjer och mer specifikt behöver medelhastigheten mellan stationer ökas. Det är därför intressant att utforska hur denna utveckling av högre hastigheter har utvecklats ur ett historiskt perspektiv. Målsättningen är även att öka förståelsen för ett antal tekniska områden och innovationer som har inverkan på ett tågs medelhastighet. Rent konkret behandlas korglutning, aerodynamik och virvelströmsbroms, som alla har en viktig inverkan på medelhastigheten. Arbetet grundar sig främst på litteraturstudier av redan kända kunskaper ur ett teknikhänseende. Information om historisk utveckling i olika länder har erhållits främst från internetkällor och där förståelse för tekniska lösningar till höghastighetståg behövts har forskningsrapporter, artiklar och doktorsavhandlingar studerats. Användning av korglutningssystem är lämpligt för tåg som trafikerar äldre järnvägslinjer där många horisontalkurvor finns. Passiv korglutningsteknik fungerar effektivt vad gäller att reducera sidoaccelerationer. Dock försämras säkerheten eftersom tyngdpunkten för tåget förskjuts i sidled. Den aktiva korglutningstekniken kompenserar för sidoaccelerationen och tyngdpunkten förskjuts marginellt. En hastighetsökning på cirka 15% och en restidsvinst på cirka 10% erhålls för ett tåg med aktiv korglutningsteknik. Underliggande komponenter hos ett tåg har stor inverkan på det aerodynamiska motståndet om vagnskorgens motståndsarea är relativt stor. Tågets ytbeskaffenheter har stor inverkan på det aerodynamiska motståndet då vagnskorgens motståndsarea är relativt liten. Längden på en tågnos har liten inverkan på det aerodynamiska motståndet om ett längd/bredd-förhållande på minst 1,0 används. En lång och spetsig akter är optimal för att reducera motståndet. Virvelströmsbromsen är effektiv i höga hastigheter men bör kompletteras med andra bromssystem vid låg- och medelhöga hastigheter. Bromsen är slitagefri och oberoende av väderlek. På grund av stor värmeutveckling kan dock solkurvor uppkomma i spåren vid använding av bromsen. / There is a large demand on increasing the mobility and efficiency for high speed rail in the world. Travellers request flexible train journeys and want to be able to get to their destinations as fast as possible. An improvement of the travelling times between stations is a must to be able to meet these claims. This can be achieved if speeds on high speed rail networks increase but more specifically if the average speed between stations increases. It is therefore of interest to explore the development of higher speeds and how it has proceeded over the years. The goal is to increase the understanding of a number of technical fields and innovations that have an impact on the average speed of a train. Specifically, the technical areas that will be treated because of their impact on average speed is tilting technology of trains, aerodynamics and eddy current brake. The work is primarily a literature survey of already known knowledge. Information about the historic development in certain countries has been obtained mainly from internet sources. Research material and doctoral theses have been studied where technical knowledge has been needed. Tilting technologies are suited for trains that run on older railway lines where a significant amount of horizontal curves are common. Passive tilting technology works effectively by reducing lateral accelerations. The safety is however impaired since the centre of gravity of the train shifts sideways. The active tilting technology compensates for the lateral acceleration and the centre of gravity shifts marginally. A running speed benefit of around 15% and a running time benefit of around 10% are achievable for a train with active tilting technology. The underneath components for a train have a big impact on the aerodynamic drag if the resistance area of the car body is relatively large. The surface roughness of the train has a big impact on the aerodynamic drag if the resistance area of the car body is relatively small. The length of the nose shape has a small impact on the aerodynamic drag if a length/width-ratio of at least 1.0 is used. The optimal shape for the purpose of reducing the drag for a train-tail should be long and pointed. The eddy current brake is effective when applied at high speeds but should be supplemented with other braking systems at low to medium speeds. The brake is wear-free and independent of the weather. A large amount of heat is however dissipated onto the rail when the brake is applied which can lead to track buckling.

Detta är ett kandidatexamensarbete om hur självkörande bilar kan se ut i framtiden. Utgående från dagens bilar och nuvarande autonoma hjälpsystem, samt system som är under utveckling och prototypbilar som företag har, dras slutsatser om hur konstruktionen hos framtida bilar kan skilja sig från idag. För att underlätta detta togs olika krav fram, som kan ställas på självkörande bilar. Dessa krav rör bland annat manövrering, uppsikt runt fordonet, oskyddade trafikanter, olika väderförhållanden och cybersäkerhet. Systemen under utveckling som undersöktes var motorvägspilot, kolonnkörning och Safe Intelligent Mobility. De prototypbilar som undersöktes var Googles självkörande bil och Mercedes F 015 Luxury in Motion. Med införandet av de nuvarande systemen har inga större konstruktionsförändringar kunnat skönjas. Framöver kan fordonen tänkas få en rundare form, sakna ytterbackspeglar och få en interiör anpassad för annat än bilkörning. Sensorer kan komma att få en mer skyddad placering, vilket kan kräva konstruktionsförändringar. / This is a Bachelor thesis about self-driving cars and their design in the future. Conclusions about the future design are drawn by analyzing today’s cars and their driver assistant systems, along with analyses of developing systems and prototype cars that companies develop. To do this, certain demands on self-driving cars were listed. They concern among others maneuverability, oversight around the car, pedestrians, different weather conditions and cyber security. The developing systems examined were highway pilot, platooning and Safe Intelligent Mobility. The prototype cars studied were Google’s self-driving car and Mercedes F 015 Luxury in Motion. With the implementation of the existing systems, no main changes in design have been made. Looking forward, vehicles could get a rounder shape, lack side mirrors and have an interior designed for other purposes than driving. Sensors could also be moved to more protected positions, which might lead to a different design.

Approximately 60 000 tonnes of tyres are produced annually in Sweden to meet thedemand in the market. It is believed that 10 000 tonnes of rubber particles contaminatesthe Swedish roads every year. Some of the elements in the emitted particles cannegatively impact the environment. These elements can lead to leaching in water thatcan cause serious problems to aquatic organisms. Furthermore worn out tyres negativelyinfluence the driving dynamics. It increases the risk of aquaplaning which can have fatalconsequences. Innovative ways of recycling tyres are constantly being developed butstill faces major challenges. It is therefore important to understand tyre wear, whatinfluences it and how to reduce it. The aim of the project is to acquire knowledge related to tyre wear, its environmentalimpacts, use a mathematical model to simulate tyre wear and study how the differentparameters influences wear. First a literature survey was performed to acquire knowledge related to tyre wear. It wasfound that tyre wear is mainly due to adhesive and hysteresis wear. Several factors werefound to affect tyre wear for example velocity, slip angle and the type of road surface.The environment impact was also studied and the results show the composition of theparticles emitted to the environment. Some of the emitted particles negatively affect theaquatic organism and human beings. In the second part of the project a mathematical model based on the well-known brushtyre model was used to simulate how wear changes with different parameters. Themodel created at KTH Vehicle Dynamics is named the expanded brush tyre model(EBM). The wear model chosen for this evaluation was the Archards wear law. Thismodel was used to be able to quantify wear and study how it is influenced by differentfactors. The result of the mathematical models shows clearly an exponential increase in thevolume of wear with increases in velocity, slip angle and vertical load. The analysis wasdone using zero camber angle. For future work it is recommended to investigate camber angle as it is also one of themajor factors that affects wear. Temperature is also another factor that was not taken into account in the study. It can also be studied in future work.

In this thesis, the concept of steering feel, as experienced by the driver, is explored. First a literature review is conducted to highlight previous work on this topic. From this review, the Norman on-centre test and steering wheel torque are identified as important concepts, and are chosen to form the base of this thesis. Following this, steering system and tyre construction are described, and a single-track mathematical model of a car and its tyres is illustrated. Those models are then implemented in Simulink and are used to simulate the Norman on-centre test and explore the effects of vehicle mass, steering ratio and power-steering servo curves on steering wheel torque. Without power steering, vehicle mass and steering ratio are identified as having the largest effect on the steering torque. With power steering added to the model, it becomes the dominating factor in shaping the steering wheel torque, and it is concluded that future research in this area is likely to focus on power-steering and steer-by-wire effects. / I denna studie kommer begreppet styrkänsla att utvärderas. Styrkänsla är samlingsnamnet för relationerna mellan rattvinkel, rattmoment och bilens dynamiska egenskaper. Tillsammans ger de föraren information om hur bilen reagerar. Litteraturstudie görs för att belysa tidigare arbete i detta område. Utifrån litteraturstudien kan Norman ”on-centre” test och rattmoment identifieras som viktiga begrepp och fokus i denna studie kommer därför att ligga på dem. En matematisk beskrivning av styrsystemet, däckegenskaper och bilens dynamik ges. En Simulinkmodel byggs upp för att simulera effekten av bilens massa, tröghetsmoment, styrutväxling och servostyrning på rattmomentet. Det visar sig att med servostyrning frånkopplad är bilens massa och styrutväxlingen mest betydelsefulla för styrkänslan. När servostyrningen adderas har servokurvan störst effekt på bilens rattmomentsuppbyggnad. Eftersom alla bilar som säljs idag har servostyrning så kommer framtida diskussioner av styrkänsla troligtvis fokusera på servostyrning och ”steer-by-wire”-system och deras effekt på styrkänslan.

The pharmaceutical industry has long been regarded as one of the most innovative industries, with ingenious products that have saved millions of lives. However, after the 1980s boom, innovation has stagnated, resulting in a high level of pressure being placed on companies. The people who work with the actual innovative aspect of discovery in these companies are the researchers. The purpose of this study is to examine how these scientists individually perceive innovation as well as setbacks in their work and what is required of them to perform innovatively. In order to find the answer to this, literature studies have been compiled together with interviews with scientists at pharmaceutical companies in the Stockholm and Uppsala region. In the course of the interviews, the main objective was to receive a broad view on how their working conditions from an innovation standpoint. During the interviews, the discussions were based on the researchers’ perspective of innovation, motivation, how they view setbacks as well as their ultimate research dream. From the interviews, I have extrapolated factors which are fundamental considerations for innovative work, both generally and in setback situations. Moreover, how setback situations are perceived, and what is considered to be success. The result from the interviews regarding innovation parameters is consistent with the theory of innovation success. All interviewees reported a significant absence of several of these factors. Above all, the importance of time, the possibility of lateral thinking through spontaneous meetings with colleagues and obstacles created by huge bureaucracy and control. The research staff did not perceive setback situations as actual setbacks but instead they deemed it as an associated factor in their profession. Half of those interviewed expressed no faith in the fact that pursuit of their work would result in a commercialized product that would help people in need.

Verksamheter utför ofta någon form av utvärdering för att utveckla sig själva och för att få in värdefulla värderingar från sina deltagare. Detta görs ibland helt utan tanke på vad det ställer för krav på utvärderingskonstruktörerna för att respondenterna ska kunna återge sin version så enkelt och verklighetsåterspeglande som möjligt. Istället utförs dem utan tanke på målgruppen och kan därför komma att generera rent av oanvändbar data. Med utgångspunkt i detta har föreningen Hello World! efterfrågat en utvärderingsmetod till sitt programmeringsläger. Syftet med denna studie är att undersöka hur en utvärderingsmetod kan utformas för att erhålla data från ungdomar på ett programmeringsläger som är enkel att fatta beslut efter, så kallad angripbar data. Hello World! är alltså en utbildningsrelaterad verksamhet med deltagande ungdomar i åldrarna 12-16 år. Målet för studien är även att anpassa utvärderingsmetoden till förutsättningarna verksamheten för med sig, varav den största är att denna utbildningsrelaterade verksamhet sker helt utanför skolan. Detta har gjorts genom att först arbeta fram ett förslag på en utvärderingsmetod med hjälp av en fokusgrupp och med stöd i tidigare forskning inom ämnet. Därefter har metoden testats iterativt fyra gånger på en högstadieskola i Stockholms kommun. Varje testtillfälle har analyserats var för sig och nästkommande iteration bygger på de tidigare. Studiens resultat tyder på att utvärderingar på ungdomar bör maskeras så att de inte upplever att de utför en utvärdering. De bör även få utföra utvärderingar i grupp, då motivation är en viktig faktor och ungdomarnas motivation ökar om de ingår i en social gemenskap. Även lägerledarna bör integreras i utvärderingen eftersom ungdomar i åldrarna 12-16 år besitter en icke fullt utvecklad kognitiv förmåga och har således en benägenhet att lämna otillräckliga svar. / Businesses are often using some sort of evaluation to get useful insight from their members and to develop themselves, but many evaluations are carried out on routine and may generate useless data or data that require an extensive analysis. The association Hello World! has on this basis asked for an evaluation method to be used on their programming camp. Hello World! is an education related business, whose participants are adolescents (12-16 years old), with the goal to motivate young individuals to the subject of programming. The purpose of this report is to examine how an evaluation method could be designed to generate actionable data from adolescents who are participating at a programming camp, called Hello World!. The purpose is also to adapt the evaluation method to the conditions that apply on a programming camp, where the most unique condition is that the camp is an education related business taking place outside the school environment. The evaluation method has been tested using an iterative approach and it was tested four times during programming sessions taking place at a lower secondary school in Stockholm Municipality. Each session has been analyzed separately and the next-coming iteration is based on the previous. The result implies that evaluations where adolescents participate should be disguised so the participants do not feel like they are evaluated. When gathering feedback from adolescents we found that evaluation done in pairs works well, because motivation is an important factor and the motivation of the adolescents increases if they are part of a social community. The camp leaders play an important part of the evaluation as well since adolescents have limited cognitive skills.

A new device gets developed almost bi-weekly, some offering a unique take on resolution or aspect ratio. For a web developer, this means that they have to constantly adapt and respond to how modern devices interact with the web, and create solutions that work for the visitors. This puts a lot of pressure on the developer to create a good, responsive webpage that is not expecting a certain device, but rather works fluently no matter the exact size of device.In this study this development is researched and discussed, from the viewpoint of what the differences are between established and future devices, what developments that might arise tomorrow and how to react to these as a developer. The goal is also to research what methods of responsive web development works best with these devices, and what might become an issue when newer devices are released and becoming widely used.The research is split up into two parts, one part comparing three popular frame- works and their responsiveness-related functions and the second part reviewing earlier work regarding responsiveness for modern devices.Modern, well developed frameworks offer a lineup of functions for responsive web development, most which integrate well when met with non-standard resolutions or devices with the tradeoff of being more heavyweight and less customizable. Research concluded that modern frameworks are covering most aspects of responsive web de- velopment, and offers a good base to implement responsive web development for future devices.Developing from having two different webpages, one mobile and one for a home PC, now almost every large webpage implements a responsive and adaptable interface which fits many more devices without slotting them into a specific niche. After this became standard, more and more unique devices could reliably browse the web. What is left is a discussion regarding what the future might hold in the case of other input devices such as voice input, small displays such as smart watch displays, and how this technique can be adapted to handle these devices as well.

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The ability to predict the mechanical properties of cells should be seen in the light of the close connection between abnormal cell states and a change in the cell response to stimuli. For example, it has been found that the stiffness of cancer cells is much lower than their healthy counterparts, influencing metastasis and cell migration. On the contrary, malaria cells have been found to exhibit a significant increase in stiffness. The major structural entity of the cell is called the cytoskeleton, an interior network consisting of three types of protein filaments - actin filaments, intermediate filaments and microtubules. The remodelling ability of the cytoskeleton through polymerisation provides the cell with the ability to adapt its response to external forces accordingly. The properties of interfilament cross-links in terms of stiffness and ability to detach can be expected to influence the mechanical response. The work presented herein focuses on the mechanical response of cross-linked actin networks. The results indicate a strong dependence of the mechanical properties on cross-link dynamics and characteristics. In Paper A, a constitutive model for the response of transiently cross-linked networks is developed using a continuum framework. The deformation is split into viscous (representing sliding of filaments) and elastic deformation. A strain energy function is proposed in the form of a neo-Hookean model, modified in terms of chemically activated cross-links. The disassociation rate constant is modified in terms of an exponential function taking into account the amount of strain energy available to break bonds. The constitutive model was compared with experimental relaxation tests and it was found that the initial region of fast stress relaxation can be attributed to breaking of bonds, and the subsequent slow relaxation to sliding of filaments. In Paper B, a finite element framework was used to assess the influence of numerous geometrical and material parameters on the response of cross-linked actin networks. It was shown that considering the presence of a statistical dispersion in filament lengths has a significant effect on the mechanical properties of the network. Further, the compliance of the crosslinks was shown to influence the stress-strain curve and shift the region of strain hardening. The influence of boundary conditions and the effect of network parameters on experiments in terms of local and global effects were also addressed. Finally, a micromechanically motivated constitutive model in a continuum framework was presented, capturing some essential characteristic features of cross-linked actin networks. / <p>QC 20131009</p>