This study explored the perception of weight in virtual reality using the combination of limiting the velocity with which an object can be lifted and control/display ratio modification and what affordances and challenges the combination might bring. Both interaction methods have thus far been explored independently, but not together. A virtual reality environment was designed that allowed each interaction method to be tested independently and together. A between-subjects user study was conducted where participants did multiple weight discrimination tasks along with a task involving absolute weight estimation. Results indicated that the combination of the two interaction methods increased the accuracy of weight discrimination considerably while not allowing for absolute weight estimation. It also increased the likelihood of noticing the interaction method with some participants that tested only one interaction method struggling to distinguish between the weights. Future work is required to reduce the frustrations that dropping objects due to the velocity limit caused among participants. / Denna studie undersökte uppfattningen om vikt i virtuell verklighet genom att kombinera begränsning av lyftförmågan hos ett objekt med ä ndring av kontroll-/visningsförhållande och vilka möjligheter och utmaningar denna kombination kan medföra. Båda interaktionsmetoderna har hittills undersökts separat, men inte tillsammans. En virtuell verklighetsmiljö utformades som möjliggjorde testning av varje interaktionsmetod separat och tillsammans. En användarstudie med mellangruppsdesign genomfördes där deltagarna utförde flera uppgifter för viktdiskriminering samt en uppgift för att uppskatta absolut vikt. Resultaten indikerade att kombinationen av de två interaktionsmetoderna avsevärt ökade noggrannheten för viktdiskriminering samtidigt som den inte tillät uppskattning av absolut vikt. Det ökade också sannolikheten för att märka interaktionsmetoden hos vissa deltagare, där de som endast testade en interaktionsmetod hade svårt att skilja mellan vikterna. Framtida arbete krävs för att minska frustrationen då ett objekt tappas på grund av hastighetsbegränsningen vilket orsakades bland deltagarna.

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This thesis examines the requirement that a supplier must have been harmed or risked being harmed in the review procedures of public procurements. The requirement for harm is analysed using the Swedish legal dogmatic method in connection with EU law. The requirement for harm is part of the implementation of the Remedies Directive, which balances the interest of protecting suppliers from unlawful decisions against the interest of effective and rapid procurement and review procedures. A review is a non-financial remedy in which the purpose is to act against unlawful decisions, preferably at a stage when no actual harm has occurred. In the case of a review, harm means that the supplier's ability of being awarded the contract is impaired. The concept of harm is thus more abstract than the required harm within tort law to receive damages (skadestånd). There are two kinds of requirements for harm in the Swedish Public Procurement Act for the review procedure. The first is that a supplier according to Chapter 20. Section 4 must consider itself to have been harmed or risked being harmed to apply for a review. Thus, it is the supplier's own perception of harm that is relevant, and the requirement is of a subjective nature. However, according to a precedent from the Swedish Supreme Administrative Court in conformity with the Remedies Directive, the supplier is also required to have an interest in obtaining the particular contract that is up for review. The second requirement is in the court's review according to Chapter 20. Sections 6 or 13-13(b), depending on the type of case. It means that a supplier must show that it has been harmed or risked being harmed due to an infringement of the Swedish Public Procurement Act. The harm must have a causal link with the alleged infringement and the particular contract up for review. Thus, the supplier needs to describe in a clear and explicit manner how the infringement has resulted in harm or risk of harm and the requirement is of a more objective nature. According to another precedent from the Swedish Supreme Administrative Court, the second requirement is not fulfilled unless the supplier has done enough to limit the harm which it is subject to. For example, by asking questions regarding an infringement in the contract documents before submitting a tender. The European Court of Justice has ruled that the objectives of the Remedies Directive are not fully implemented if a supplier is allowed to apply for a review at any stage, as has long been the case in Swedish law. However, there is no limitation period or general obligation for suppliers to limit harm in the event of a review according to EU law or previous Swedish law. Thus, there is an uncertainty regarding the exact scope of the second requirement of harm. / https://urt.cc/reportage/skada-vid-overprovning/

Lasers are increasingly used for a wide range of different applications for both civil and military purposes. Due to the distinct properties of laser light, use of lasers often comes with a risk of damage to the human eye and other optical sensors. Therefore, an effective laser protection is needed. 2D-materials is a relatively new class of materials, which have shown to possess many unique properties compared to its bulk counterparts. Some 2D-materials exhibit nonlinear optical (NLO) properties, and specifically optical power limiting (OPL) effects, and have therefore been researched for laser protection applications. In this work, two different 2D-materials, MXene Ti3C2 and graphene oxide (GO), have been combined with a hybrid organic-inorganic polymer, a so called melting gel (MG), to synthesise nanocomposites possessing OPL effects for laser protection applications. Different methods of incorporating the 2D-materials in the polymer matrix as well as the effect on optical properties of different concentrations of 2D-materials were investigated. The prepared nanocomposites were characterised using optical microscopy, spectroscopy and OPL measurements in order to investigate and quantify their linear and nonlinear optical properties. The MG was optically clear, mechanically stable and easy to synthesise, which makes it a suitable candidate as a matrix for a laser protection nanocomposite. Additionally, it was possible to dope the MG with the two different 2D-materials to create nanocomposites showing desirable optical properties in the visible spectrum. However, many samples showed signs of clustered 2D-particles indicating that the dispersion could be improved. Finally, OPL measurements, performed at 532 nm, showed that the MG itself exhibited OPL effects, both 2D-materials showed a stronger OPL effect than the non-doped MG and that GO-doped samples gave a better protection than the MXene samples.

This thesis investigates some problems related to the form and shape of statistical distributions with the main focus on goodness of fit and bump hunting. A bump is a distinctive characteristic of distributional shape. A search for bumps, or bump hunting, in a probability density function (PDF) has long been an important topic in statistical research. We introduce a new definition of a bump which relies on the notion of the curvature of a planar curve. We then propose a new method for bump hunting which is based on a kernel density estimator of the unknown PDF. The method gives not only the number of bumps but also the location of their centers and base points. In quantitative risk applications, the selection of distributions that properly capture upper tail behavior is essential for accurate modeling. We study tests of distributional form, or goodness-of-fit (GoF) tests, that assess simple hypotheses, i.e., when the parameters of the hypothesized distribution are completely specified. From theoretical and practical perspectives, we analyze the limiting properties of a family of weighted Cramér-von Mises GoF statistics W2 with weight function psi(t)=1/(1-t)^beta (for beta<=2) which focus on the upper tail. We demonstrate that W2 has no limiting distribution. For this reason, we provide a normalization of W2 that leads to a non-degenerate limiting distribution. Further, we study W2 for composite hypotheses, i.e., when distributional parameters must be estimated from a sample at hand. When the hypothesized distribution is heavy-tailed, we examine the finite sample properties of W2 under the Chen-Balakrishnan transformation that reduces the original GoF test (the direct test) to a test for normality (the indirect test). In particular, we compare the statistical level and power of the pairs of direct and indirect tests. We observe that decisions made by the direct and indirect tests agree well, and in many cases they become independent as sample size grows. / Thesis / Doctor of Philosophy (PhD)

The advent of wide band-gap semiconductors in power electronics has led to the scope of efficient power conversion being pushed further than ever before. This development has allowed for systems to operate at higher and higher voltages than previously achieved. One area of consideration during this high voltage transition is the synchronous rectifier, which is traditionally designed as an afterthought. Prior research in synchronous rectifiers have been limited to low voltage, high current converters. There is practically no research in high voltage synchronous rectification. Therefore, this dissertation focuses on discovering the unknown nuances behind high voltage synchronous rectifier design, and ultimately developing a practical, scalable solution. There are three main issues that must be addressed when designing a high voltage synchronous rectifier: (1) high voltage sensing; (2) light load effects; (3) accuracy. The first hurdle to designing a high voltage SR system is the high voltage itself. Traditional methods of synchronous rectification (SR) attempt to directly sense voltage or current, which is not possible with high voltage. Therefore, a solution must be designed to limit the voltage seen by the sensing mechanism without sacrificing accuracy. In this dissertation, a novel blocking solution is proposed, analyzed, and tested to over 1-kV. The solution is practical enough to be implemented on practically any commercial drain-source SR controller. The second hurdle is the light load effect of the SR system on the converter. A large amount of high voltage systems utilize a LLC-based DC transformers (DCX) to provide an efficient means of energy conversion. The LLC-DCX's attractive attributes of soft-switching and high efficiency allure many architects to combine it with an SR system. However, direct implementation of SR on a LLC-DCX will result in a variety of light load oscillation issues, since the rectifier circuitry can excite the resonant tank through a false load transient phenomena. A universal limiting solution is proposed and analyzed, and is validated with a commercial SR controller. The final hurdle is in optimizing the SR system itself. There is an inherent flaw with drain-source sensing, namely parasitic inductance in the drain-source sense loop. This parasitic inductance causes an error in the sensed voltage, resulting in early SR turn-off and increased losses through the parallel diode. The parasitic will always be present in the circuit, and current solutions are too complex to be implemented. Two solutions are proposed depending on the rectifier architecture: (1) multilevel gate driving for single switch rectifiers; (2) sequential parallel switching for parallel switch rectifiers. In summary, this dissertation focuses on developing a practical and reliable high voltage SR solution for LLC-DCX converters. Three main issues are addressed: (1) high voltage sensing; (2) light load effects; (3) accuracy. Novel solutions are proposed for all three issues, and validated with commercial controllers. / Doctor of Philosophy / High voltage power electronics are becoming increasing popular in the electronics industry with the help of wide band-gap semiconductors. While high voltage power electronics research is prevalent, a key component of high voltage power converters, the synchronous rectifier, remains unexplored. Conventional synchronous rectifiers are implemented on high current circuits where diode losses are high. However, high voltage power electronics operate at much lower current levels, necessitating changes in current synchronous rectifier methods. This research aims to identify and tackle issues that will be faced by both systems and IC designers when attempting to implement high voltage synchronous rectifiers on LLC-DCXs. While development takes planes on a LLC-DCX, the research is applicable to most resonant converters and applications utilizing drain-source synchronous rectifier technology. This dissertation focuses primarily on three areas of synchronous rectifier developments: (1) high voltage compatibility; (2) light load effects; (3) accuracy. The first issue opens the gate to high voltage synchronous rectifier research, by allowing high voltage sensing. The second issue explores issues that high voltage synchronous rectifiers can inadvertently influence on the LLC-DCX itself - a light load oscillation issue. The third issue explores novel methods of improving the sensing accuracy to further reduce losses for a single and parallel switch rectifier. In each of these areas, the underlying problem is root-caused, analyzed, and a solution proposed. The overarching goal of this dissertation is to develop a practical, low-cost, universal synchronous rectifier system that can be scaled for commercial use.

Bakgrund: Den palliativa vården ska se till hela familjens behov av stöd. Lagen är tydlig vad gäller barns rättigheter när en förälder är sjuk, men syskon som grupp blir ofta förbisedda. Syskon som mist en närstående har ökad risk för ångest och depression, men löper även högre risk för missbruk, och detta kan relateras till hur syskonen upplevde situationen när deras bror eller syster var sjuk. Barn och unga är en särskilt sårbar grupp som behöver extra omsorg i och med en högre risk för komplicerad och långvarig sorg, och sjukvården har ett ansvar i att stötta dessa individer. Genom ökad kunskap om syskons erfarenheter av att leva med en svårt sjuk bror eller syster kan vi konstruera adekvat stöd baserat på deras behov. Syfte: Att beskriva syskons erfarenheter av att leva med en svårt sjuk bror eller syster. Metod: En litteraturöversikt baserad på 13 originalartiklar, insamlade från två databaser, publicerade mellan 2013–2023. En tematisk analys gjordes utifrån Braun och Clarkes analysmodell. Resultat: Tre huvudteman framkom vid sammanställning av resultat: Att hantera sig själv och sina känslor beskriver syskonens utsatthet och känsla av isolering - en känsla av att hamna i skuggan av sin bror eller systers sjukdom, där en stark önskan om att bli sedd, men en ovilja att ta plats framkom, och stöd från omgivningen var uppskattat. Känslan av förståelse beskriver att information och inkludering uppskattas - att de oftast vet om när saker går osagda och att de själva tvingas läsa mellan raderna kring vad de ser och vad som sägs. Det nya normala beskriver förändring i situation och vardag - där familjen blev allt viktigare, men att rollerna inom familjen förändrades, och det ständigt fanns en närvaro av oro kring den sjuka brodern eller systern. Slutsats: Sjuksköterskor och annan vårdpersonal bör känna till och beakta syskons känsloliv och önskningar för att på bästa sätt kunna stötta och hjälpa syskonet genom den svåra tiden. För att nå upp till barnkonventionen, som numera är lag, gäller detta även för sjukvårdspersonal inom vuxenvården, då barn som har palliativa vårdbehov många gånger vårdas inom vuxenkliniker. / Background: Palliative care must take care of the entire family's need for support. The law is clear regarding children's rights when a parent is ill, but siblings as a group are often overlooked. Siblings who have lost a loved one have an increased risk of anxiety and depression, but are also at higher risk of substance abuse, and this can be related to how the sibling experienced the situation when their brother or sister was ill. Children and young people are a particularly vulnerable group that needs extra care due to a higher risk of complicated and prolonged grief, and the healthcare system has a responsibility to support these individuals. Through increased knowledge of siblings' experiences of living with a seriously ill brother or sister, we can construct adequate support for these children based on their needs.  Aim: To describe the siblings' experiences of living with a seriously ill brother or sister. Method: A literature review based on 13 original articles, collected from two databases, published between 2013-2023. A thematic analysis was made based on Braun and Clarke's analysis model. Results: Three main themes emerged when compiling results: Dealing with oneself and one's feelings - describes the sibling's vulnerability and sense of isolation, a feeling of being overshadowed by their brother or sister's illness, where a strong desire to be seen, but an unwillingness to take place emerged, and support from the environment was appreciated. The feeling of understanding - describes that information and inclusion are appreciated, that they usually know when things are left unsaid and that they themselves are forced to read between the lines regarding what they see and what is said. The new normal - describes a change in situation and everyday life, where the family became increasingly important, but the roles within the family changed, and there was a constant presence of concern around the sick brother or sister. Conclusion: Nurses and other healthcare personnel should know and consider the sibling's emotional life and wishes in order to best support and help the sibling through the difficult time. In order to meet the Convention on the Rights of the Child, which is now law, this also applies to healthcare staff in adult care, as children who have palliative care needs are often cared for in adult clinics.

Bakgrund: Den palliativa vården ska se till hela familjens behov av stöd. Lagen är tydlig vad gäller barns rättigheter när en förälder är sjuk, men syskon som grupp blir ofta förbisedda. Syskon som mist en närstående har ökad risk för ångest och depression, men löper även högre risk för missbruk, och detta kan relateras till hur syskonen upplevde situationen när deras bror eller syster var sjuk. Barn och unga är en särskilt sårbar grupp som behöver extra omsorg i och med en högre risk för komplicerad och långvarig sorg, och sjukvården har ett ansvar i att stötta dessa individer. Genom ökad kunskap om syskons erfarenheter av att leva med en svårt sjuk bror eller syster kan vi konstruera adekvat stöd baserat på deras behov. Syfte: Att beskriva syskons erfarenheter av att leva med en svårt sjuk bror eller syster. Metod: En litteraturöversikt baserad på 13 originalartiklar, insamlade från två databaser, publicerade mellan 2013–2023. En tematisk analys gjordes utifrån Braun och Clarkes analysmodell. Resultat: Tre huvudteman framkom vid sammanställning av resultat: Att hantera sig själv och sina känslor beskriver syskonens utsatthet och känsla av isolering - en känsla av att hamna i skuggan av sin bror eller systers sjukdom, där en stark önskan om att bli sedd, men en ovilja att ta plats framkom, och stöd från omgivningen var uppskattat. Känslan av förståelse beskriver att information och inkludering uppskattas - att de oftast vet om när saker går osagda och att de själva tvingas läsa mellan raderna kring vad de ser och vad som sägs. Det nya normala beskriver förändring i situation och vardag - där familjen blev allt viktigare, men att rollerna inom familjen förändrades, och det ständigt fanns en närvaro av oro kring den sjuka brodern eller systern. Slutsats: Sjuksköterskor och annan vårdpersonal bör känna till och beakta syskons känsloliv och önskningar för att på bästa sätt kunna stötta och hjälpa syskonet genom den svåra tiden. För att nå upp till barnkonventionen, som numera är lag, gäller detta även för sjukvårdspersonal inom vuxenvården, då barn som har palliativa vårdbehov många gånger vårdas inom vuxenkliniker. / Background: Palliative care must take care of the entire family's need for support. The law is clear regarding children's rights when a parent is ill, but siblings as a group are often overlooked. Siblings who have lost a loved one have an increased risk of anxiety and depression, but are also at higher risk of substance abuse, and this can be related to how the sibling experienced the situation when their brother or sister was ill. Children and young people are a particularly vulnerable group that needs extra care due to a higher risk of complicated and prolonged grief, and the healthcare system has a responsibility to support these individuals. Through increased knowledge of siblings' experiences of living with a seriously ill brother or sister, we can construct adequate support for these children based on their needs. Aim: To describe the siblings' experiences of living with a seriously ill brother or sister. Method: A literature review based on 13 original articles, collected from two databases, published between 2013-2023. A thematic analysis was made based on Braun and Clarke's analysis model. Results:Three main themes emerged when compiling results: Dealing with oneself and one's feelings - describes the sibling's vulnerability and sense of isolation, a feeling of being overshadowed by their brother or sister's illness, where a strong desire to be seen, but an unwillingness to take place emerged, and support from the environment was appreciated. The feeling of understanding - describes that information and inclusion are appreciated, that they usually know when things are left unsaid and that they themselves are forced to read between the lines regarding what they see and what is said. The new normal - describes a change in situation and everyday life, where the family became increasingly important, but the roles within the family changed, and there was a constant presence of concern around the sick brother or sister. Conclusion: Nurses and other healthcare personnel should know and consider the sibling's emotional life and wishes in order to best support and help the sibling through the difficult time. In order to meet the Convention on the Rights of the Child, which is now law, this also applies to healthcare staff in adult care, as children who have palliative care needs are often cared for in adult clinics.

<p>Computer programs keep finding their ways into new safety-critical applications, while at the same time growing more complex. This calls for new and better methods to verify the correctness of software. We focus on one approach to verifying systems, namely that of <i>model checking</i>. At first, we investigate two categories of problems related to model checking: <i>games</i> and <i>stochastic infinite-state systems</i>. In the end, we join these two lines of research, by studying <i>stochastic infinite-state games</i>.</p><p>Game theory has been used in verification for a long time. We focus on finite-state 2-player parity and limit-average (mean payoff) games. These problems have applications in model checking for the <i>μ</i>-calculus, one of the most expressive logics for programs. We give a simplified proof of memoryless determinacy. The proof applies <i>both</i> to parity and limit-average games. Moreover, we suggest a strategy improvement algorithm for limit-average games. The algorithm is discrete and strongly subexponential.</p><p>We also consider probabilistic infinite-state systems (Markov chains) induced by three types of models. <i>Lossy channel systems (LCS)</i> have been used to model processes that communicate over an unreliable medium. <i>Petri nets</i> model systems with unboundedly many parallel processes. <i>Noisy Turing machines</i> can model computers where the memory may be corrupted in a stochastic manner. We introduce the notion of <i>eagerness</i> and prove that all these systems are eager. We give a scheme to approximate the value of a reward function defined on paths. Eagerness allows us to prove that the scheme terminates. For probabilistic LCS, we also give an algorithm that approximates the limit-average reward. This quantity describes the long-run behavior of the system.</p><p>Finally, we investigate Büchi games on probabilistic LCS. Such games can be used to model a malicious cracker trying to break a network protocol. We give an algorithm to solve these games.</p>

Computer programs keep finding their ways into new safety-critical applications, while at the same time growing more complex. This calls for new and better methods to verify the correctness of software. We focus on one approach to verifying systems, namely that of model checking. At first, we investigate two categories of problems related to model checking: games and stochastic infinite-state systems. In the end, we join these two lines of research, by studying stochastic infinite-state games. Game theory has been used in verification for a long time. We focus on finite-state 2-player parity and limit-average (mean payoff) games. These problems have applications in model checking for the μ-calculus, one of the most expressive logics for programs. We give a simplified proof of memoryless determinacy. The proof applies both to parity and limit-average games. Moreover, we suggest a strategy improvement algorithm for limit-average games. The algorithm is discrete and strongly subexponential. We also consider probabilistic infinite-state systems (Markov chains) induced by three types of models. Lossy channel systems (LCS) have been used to model processes that communicate over an unreliable medium. Petri nets model systems with unboundedly many parallel processes. Noisy Turing machines can model computers where the memory may be corrupted in a stochastic manner. We introduce the notion of eagerness and prove that all these systems are eager. We give a scheme to approximate the value of a reward function defined on paths. Eagerness allows us to prove that the scheme terminates. For probabilistic LCS, we also give an algorithm that approximates the limit-average reward. This quantity describes the long-run behavior of the system. Finally, we investigate Büchi games on probabilistic LCS. Such games can be used to model a malicious cracker trying to break a network protocol. We give an algorithm to solve these games.