Climate change impacts assessment on railway infrastructure in urban environments

Climate change impacts can escalate the deteriorating rate of infrastructures and impact the infrastructure’s functionality, safety, operation and maintenance (O&amp;M). This research explores climate change’s influence on urban railway infrastructure. Given the geographical diversity of Sweden, the railway network is divided into different climate zones utilizing the K-means algorithm. Reliability analysis using the Cox Proportional Hazard Model is proposed to integrate meteorological parameters and operational factors to predict the degree of impacts of different climatic parameters on railway infrastructure assets. The proposed methodology is validated by selecting a number of switches and crossings (S&amp;Cs), which are critical components in railways for changing the route, located in different urban railway stations across various climate zones in Sweden. The study explores various databases and proposes a climatic feature to identify climate-related risks of S&amp;C assets. Furthermore, different meteorological covariates are analyzed to understand better the dependency between asset health and meteorological parameters. Infrastructure asset managers can tailor suitable climate adaptation measures based on geographical location, asset age, and other life cycle parameters by identifying vulnerable assets and determining significant covariates. Sensitivity analysis of significant covariates at one of the urban railway stations shows precipitation increment reveal considerable variation in the asset reliability.Validerad;2023;Nivå 2;2023-12-04 (joosat);License full text: CC BY 4.0</p

Spectral properties of a class of operator functions with applications to the Moore-Gibson-Thompson equation with memory

In this study, we present spectral enclosures and accumulation of eigenvalues of a class of operator functions with several unbounded operator coefficients. Our findings have direct relevance to the third-order Moore-Gibson-Thompson equation with memory and additional damping. The new results include sufficient conditions for the accumulation of branches of eigenvalues to the essential spectrum and new spectral enclosures for operator functions with several unbounded operator coefficients. To illustrate the analytical results, we apply the abstract findings to concrete equations of the Moore-Gibson-Thompson type. Additionally, we employ numerical computations to further elucidate the analytical results

What did you expect? : A human-centered approach to investigating and reducing the social robot expectation gap

We live in a complex world where we proactively plan and execute various behaviors by forming expectations in real time. Expectations are beliefs regarding the future state of affairs and they play an integral part of our perception, attention, and behavior. Over time, our expectations become more accurate as we interact with the world and others around us. People interact socially with other people by inferring others' purposes, intentions, preferences, beliefs, emotions, thoughts, and goals. Similar inferences may occur when we interact with social robots. With anthropomorphic design, these robots are designed to mimic people physically and behaviorally. As a result, users predominantly infer agency in social robots, often leading to mismatched expectations of the robots' capabilities, which ultimately influences the user experience.  In this thesis, the role and relevance of users' expectations in first-hand social human-robot interaction (sHRI) was investigated. There are two major findings. First, in order to study expectations in sHRI, the social robot expectation gap evaluation framework was developed. This framework supports the systematic study and evaluation of expectations over time, considering the unique context where the interaction is unfolding. Use of the framework can inform sHRI researchers and designers on how to manage users’ expectations, not only in the design, but also during evaluation and presentation of social robots. Expectations can be managed by identifying what kinds of expectations users have and aligning these through design and dissemination which ultimately creates more transparent and successful interactions and collaborations. The framework is a tool for achieving this goal. Second, results show that previous experience has a strong impact on users’ expectations. People have different expectations of social robots and view social robots as both human-like and as machines. Expectations of social robots can vary according to the source of the expectation, with those who had previous direct experiences of robots having different expectations than those who relied on indirect experiences to generate expectations.     One consequence of these results is that expectations can be a confounding variable in sHRI research. Previous experience with social robots can prime users in future interactions with social robots. These findings highlight the unique experiences users have, even when faced with the same robot. Users' expectations and how they change over time shapes the users’ individual needs and preferences and should therefore be considered in the interpretation of sHRI. In doing so, the social robot expectation gap can be reduced.Vi lever i en komplex värld och för att kunna hantera denna komplexitet formar vi förväntningar. Förväntningar är antaganden om framtida tillstånd och är en vital del av vår perception, uppmärksamhet och beteende. Genom att interagera med omvärlden och andra människor blir våra förväntningar mer precisa och korrekta över tid. I en social interaktion behöver vi förstå den andra personens syften, avsikter, preferenser, övertygelser, känslor, tankar och mål. Sociala robotar är utformade för att skapa liknande inferenser när användare interagerar med dem. Detta kan leda till missbedömningar mellan vad vi förväntar oss av sociala robotar och vad dessa artefakter är kapabla till, vilket påverkar användarupplevelsen av sociala robotar. I den här avhandlingen presenteras den forskning som har utförts för att studera rollen och relevansen av människors förväntningar i social människa-robotinteraktion (sMRI). Resultaten kan delas in i två större fynd. Det första fyndet är ett utvärderingsramverk som ämnar att systematiskt studera användares förväntningar av sociala robotar i en interaktion, med fokus på hur förväntningar ändras över tid i en interaktion, med interaktionens unika kontext i åtanke. Ramverket är menat för designers av sociala robotar och forskare inom sMRI-fältet för att bättre studera, hantera, och förstå förväntningar, både i robotarnas design och i robotarnas agerande. Det andra fyndet består av de empiriska resultat som visar hur tidigare erfarenheter påverkar användares förväntningar. Förväntningarna baseras till stor del på vilka typer av tidigare erfarenheter användare har, där de med direkta erfarenheter av robotar har andra förväntningar än de med indirekta erfarenheter. Vidare visar resultaten att användare ser sociala robotar både som människolika och som maskiner samtidigt. Förväntningar kan också ses som en bakomliggande variabel inom sMRI-forskning eftersom tidigare erfarenheter kan påverka deltagare i kommande interaktioner med sociala robotar. Resultaten visar även att användarupplevelsen är unik för varje an[1]vändare, även om roboten är densamma, vilket bör tas i åtanke när resultat tolkas i en sMRI-kontext. Genom att ha förväntningar i åtanke kan vi minska det gap som uppstår mellan människors förväntningar av sociala robotar och robotarnas faktiska förmågor. På så sätt kan vi främja positiva användarupplevelser och förbättra interaktionen mellan människa och robot.Två av sju delarbeten (övriga se rubriken Delarbeten/List of papers):VI Rosén, Julia, Lindblom, Jessica, Lamb, Maurice, and Billing, Erik (Under review). “Previous Experience Matters: An In-Person Investigation of Expectations in Human-Robot Interaction”. In: Under review for scientific journal, pp. 1–19.VII Lindblom, Jessica, Rosén, Julia, Lamb, Maurice, and Billing, Erik (Manuscript). “Disentangling People’s Experiences and Expectations when Interacting with the Social Robot Pepper: A Qualitative Analysis”. In: Manuscript for scientific journal, pp. 1–41.</p

The Tension Between Division and Fair Share

This study focuses on sharing, both in equal parts (groups) or unequal parts. Children at age five attending preschool, are faced with two different tasks working in pairs. The analysis focus on the mathematical properties in the reasoning, or when mathematical arguments were replaced with an ethical reasoning. When performing division, different strategies were used, and the norm of fair share was often expressed. It was easier for the children to allocate resources when the dividend was larger than the divisor, and when dealing with a fraction, the cardinality of the number of parts appeared to be a prominent property compared to property ‘equal size’ of the parts. There were also indications of ethical reasoning where the child used different claims to convince their peer. There was a tension between the norm of equal sharing and solutions with unequal parts. One implication is that if wanting to challenge children’s mathematical reasoning in a division task, it could be fruitful to look at fractions instead of repeating tasks where the dividend is larger than the divisor

Simulator-based driving test prescreening as a complement to driver testing : Toward safer and more risk-aware drivers

Young people represent a high-risk group of drivers and the prevalence of road traffic crashes among young drivers is high. Thus, to increase traffic safety, it is essential to ensure that new drivers are both sufficiently educated in and assessed for risk awareness. The aim of this study was to examine the possibility and potential benefit of using a driving simulator screening test as a complement to the existing on-road driving test. The main idea is to detect drivers who are not ready to proceed to the driving test. A comparative study was performed with participants who passed and failed a simulator test and an on-road driving test, respectively. A comparison between subjective and objective measures of performance and risk was also included. A driving simulator was placed at a traffic school and customers were recruited as participants. In total, 70 participants took part in the study and the simulated drive consisted of rural roads, urban traffic, and motorways with 16 different scenarios, constructed from the second level of the GDE matrix, to examine driving behavior, attention, and risk perception. The results show that with a screening test in a driving simulator, it is possible to detect drivers who consider themselves ready to take a driving test, but who have not yet reached the level of risk awareness required to be a safe driver. Test scenarios should be suited to detect deficiencies in risk awareness, test different levels of the GDE matrix and, to complement the driving test, be difficult to assess in an on-road driving test. Deficiencies in self-evaluation that are well-known among young drivers are again confirmed. To practice self-evaluation, the driving simulator is suggested as a pedagogical tool, linked to the GDE matrix

Lean, mean sleep machine? : Effects and experiences of a sleep robot intervention for adults with insomnia

Many adults suffer from insomnia disorder, struggling to fall asleep, stay asleep, or with early morning awakenings. Hyperarousal is an important predisposing, precipitating and perpetuating factor to insomnia. Anxiety, depression and ADHD are common comorbid disorders, with shared cognitive, behavioral, genetic, and neurological features. Cognitive Behavioral Therapy for insomnia (CBT-I) is the gold-standard treatment, more effective and economical than pharmacological treatments, though not suitable or available for everyone. Unfortunately, sleeping pills are still more common than CBT-I, despite known risks. One potential treatment avenue is consumer sleep technology, including interventional sleep robots.  This thesis aimed to assess the safety, acceptability, effects, and experiences of a commercial sleep robot for insomnia in adults. Overall, the thesis does not strongly support the sleep robot as an effective insomnia treatment. The intervention might not have addressed important precipitating factors of the participants’ insomnia, and the robot’s impact on stress reactivity and other potentially important factors remain uncertain. Until more robust research studies are conducted, the current sleep robot intervention should not be considered an evidence-based treatment for adults with insomnia.Many adults suffer from insomnia disorder, which entails a difficulty initiating sleep and maintaining sleep, or undesired early morning awakenings coupled with trouble going back to sleep. Hyperarousal is an important causal and maintaining factor in insomnia. Furthermore, comorbid conditions such as anxiety, depression, and ADHD are common. The first line treatment of insomnia is Cognitive Behavioral Therapy, which has been found to be more effective and economical than pharmaceuticals, albeit not suitable or available for all. Sleeping pills are still the most common treatments of insomnia, which is unfortunate due to established risks. Thus, research on credible treatment options is warranted. One potential type of treatment is consumer sleep technology. The current thesis aimed to assess the safety, acceptability, effects, and experiences of the Somnox sleep robot in adults with insomnia. Overall, the findings from the studies included in the thesis were not strongly in support of the Somnox sleep robot effectively alleviating symptoms of insomnia in adults. To further improve the understanding of the efficiency of technological devices in reducing arousal, future studies could investigate their impact on stress reactivity levels in participants (as opposed to a generalized hyperarousal), with or without prior stress inducement. There is a lack of empirical evidence on whether relaxation techniques actually improve participants’ sleep. It is also possible that the robot could improve sleep through means other than reducing arousal (e.g., stimulus control). Additionally, without measuring participants’ breathing, it is unclear if potentially reduced arousal is due to more adaptive breathing. Nonetheless, it is important to assess first whether the intervention has any effects at all. Until there is substantial evidence from more studies that demonstrate its efficacy, the Somnox sleep robot should not be considered an evidence-based treatment of insomnia

Intralymphatic Immunotherapy : A Novel Route to Ameliorate Allergic Rhinitis Due to Pollen

Allergy to pollen and animal dander is a major public health problem. Close to 30% of the population have symptoms from the upper and/or lower respiratory tract when they meet fur animals or pollen. Whereas symptom-relieving medications have a good to sufficient effect on about 80% of those affected, a large group of 10–20% have severe symptoms, despite medication, with an impact on well-being and ability to work. In Sweden, the annual cost of allergy was calculated at €1.3 billion in 2014. Immunotherapy is effective in treating and preventing pollen allergy and allergic asthma, but is expensive, complicated, requiring 40 injections, and takes more than three years to complete if subcutaneous injections are used. Tablets placed under the tongue are another method, with one tablet taken every day for three years. Only 1.5‰ receive such treatment, yet just over 3% would need it. With intralymphatic immunotherapy, a small dose of allergen is given in a lymph node in the groin on 3 occasions, one month apart. As this method takes only eight weeks, it is a much faster and less costly treatment. However, although several studies have shown that the treatment is safe, its efficacy remains the subject of doubt. Our pilot study in 2012, with a 3-year follow-up to 2015, showed encouraging results, and was followed by a double-blind randomised study with 72 participants from 2014 to 2018. The research subjects then received treatment with birch and grass pollen extract or one extract and a placebo. Regardless of treatment, symptoms, quality of life and medication consumption improved during the birch and grass pollen seasons in the 3 years after treatment. Increased frequencies of T-regulatory lymphocytes may explain the non-specific effects. In 2017 to 2018, we conducted a double-blind study with 38 participants, half of whom received placebo and half, active treatment. In this study, we saw no difference between the treatment groups in the first year after treatment. However, after discontinuation and unblinding in 2019, i.e., two years after treatment, the actively treated group improved in terms of symptoms, and quality of life was improved compared with the placebo group despite less need for medication. T-regulatory lymphocytes increased one year after treatment only in the actively treated group. A long-term follow-up of the research subjects from our two larger studies in 2022, i.e., five to eight years after treatment, showed in the double-blind study without a pure placebo that the scores for symptoms, medication use, and quality of life remained as low as after the first three years. In the placebo-controlled study, a statistically significant improvement in symptoms remained during the grass pollen season. Analysing the two studies together, symptom improvement was significant even during the birch pollen season. Thus, although the effect does not seem to diminish, those who did not receive birch, but only grass, needed to use more medication during the birch pollen season in 2022, seven to eight years after treatment. Moreover, those who did not receive grass but only birch needed more medication during the grass pollen season. This may suggest that the non-specific effect begins to wane after seven to eight years. Allergy to pollen is a major problem for individuals and society, where symptom-relieving treatment with drugs is not enough for many. They can be helped with immunotherapy, which takes at least three years, is expensive and fraught with side effects. In contrast, intralymphatic immunotherapy involves three injections over eight weeks. Our three studies show that the treatment is safe and indicate that it has a clinical effect up to eight years after treatment. T-regulatory cells appear to be important to the immunological mechanism, leading to tolerance to pollen.Funding agencies: Region Östergötland, the Allergy Center in Linköping, the Medical Research Council of Southeast Sweden (FORSS), the Th Bergh Foundation and the Asthma and Allergy Association</p

How much is just maths? : Investigating problem solving in chemical kinetics at the interface of chemistry and mathematics through the development of an extended mathematical modelling cycle

Problem solving in chemical kinetics poses substantial challenges for university students since it often involves significant use of mathematics as a tool and language, with challenging translations and transitions between chemical phenomena and mathematical representations. In this paper, we present key findings from a study investigating chemistry students solving tasks centred around the steady-state approximation. Building upon the mathematical modelling cycle (MMC), qualitative analysis of the data collected using a think-aloud protocol led to the development of the extended MMC. This empirically derived extended MMC offers a more detailed account of the processes involved in mathematical modelling of chemical phenomena, highlighting aspects such as the occurrence of deliberation and evaluation throughout the modelling cycle, as well as the varying characteristics, points of activation and roles of extra-mathematical resources during problem solving. We further introduce and use problem-solving trajectories as a tool for visualising and analysing the complex and diverse approaches used by students in their attempts at reaching a solution. Overall, the extended MMC provides a finer-grained model of the cognitive and metacognitive activities that students engage in, offering further insights for research and practice

Constructing Poly(Ionic Liquid)s-Based Composite Solid State Electrolytes and Application in Lithium Metal Batteries

The pursuit of reliable and high-performance batteries has fueled extensive research into new battery chemistries and materials, aiming to enhance the current lithium-ion battery technologies in terms of energy density and safety. Among the potential advancements, solid-state batteries (SSBs) have captured significant attention as the next-generation energy storage technology. One key factor contributing to their appeal is the utilization of solid-state electrolytes (SSEs) with a wide electrochemical stability window (ESW), making SSBs compatible with high-voltage cathodes. The energy density of SSBs can be further improved by employing the “holy-grail” anode, Li-metal, which boasts the lowest working voltage (-3.04 V vs. Li+/Li) and an ultrahigh theoretical capacity (3860 mAh g−1). Consequently, these batteries are referred to as lithium metal batteries (LMBs). However, realizing the full potential of LMBs presents formidable challenge, including the low ionic conductivity of current SSEs, large interfacial resistance between SSE and electrodes, uncontrollable interfacial reactions, and the growth of Li dendrites.  Typically, SSEs can be categorized into three types. Among these, solid composite electrolytes (SCEs) are considered the most promising choice for solid-state LMBs due to their combination of high ionic conductivity and excellent mechanical strength from inorganic solid electrolytes (ISEs) and the flexibility and good interface compatibility provided by solid polymer electrolytes (SPEs). Polymeric ionic liquids (PolyILs), which contain both ionic liquid-like moieties and polymer frameworks, have emerged as highly attractive alternatives to traditional polymers in SCEs.  The overall objective of this thesis was to develop PolyIL-based SCEs with enhanced ionic conductivity, wide ESW, high Li+ transference number, and reduced electrodes/electrolyte interface resistance. The main progress achieved in this thesis is as follows: 1. We selected three F-based Li-salts to prepare SPEs using poly(ethylene oxide) and polyimide. The investigation focused on assessing the impact of molecular size, F content, and chemical structures (F-connecting bonds) of these Li-salts. Additionally, we aimed to uncover the formation process of LiF in the solid electrolyte interphase (SEI). The result revealed that the F-connecting bond plays a more significant role than the molecular size and F element content, resulting in slightly better cell performance using LiPFSI compared to LiTFSI and substantially better performance compared to LiFSI. The preferential breakage of bonds in LiPFSI was found to be related to its position to Li anode. Consequently, we proposed the LiPFSI reduction mechanism based on these findings. 2. Using the template method, we synthesized a monolayer SCE with enhanced Li+ transference number and high ionic conductivity. In this study, boron nitride (BN) nanosheets with a high specific surface area and richly porous structure were employed as inert inorganic filler. These BN nanosheets played a crucial role in homogenizing the Li+ flux and facilitating the Li+ transmission to suppress Li dendrite growth. When integrated into a LiFePO4//Li cell with the optimized SCE, the assembled battery demonstrated remarkable cycling performance.  3. A monolayer GSCE with multifunctionality was synthesized via a natural sedimentation and subsequent UV-curing polymerization technique. This innovative method capitalizes on intrinsic gravity, allowing for the integration of multiple functions within a single layer, thereby eliminating the additional interlayer resistance. The developed GSCE provides an optimum Li+ transportation path and enhanced Li+ transference number, leading to an enhanced ionic conductivity and a long cycle life of Li//Li cells and SSLMBs. Compared with the monolayer uniform SCEs, the gradient structure also alleviates the uncoordinated thermal expansion between fillers and PolyIL, avoiding increased stress during the cycle and battery capacity fade

Optical frequency comb Fourier transform spectroscopy of formaldehyde in the 1250 to 1390 cm−1 range : experimental line list and improved MARVEL analysis

We use optical frequency comb Fourier transform spectroscopy to record high-resolution, low-pressure, room-temperature spectra of formaldehyde (H212C16O) in the range of 1250 to 1390 cm−1. Through line-by-line fitting, we retrieve line positions and intensities of 747 rovibrational transitions: 558 from the ν6 band, 129 from the ν4 band, and 14 from the ν3 band, as well as 46 from four different hot bands. We incorporate the accurate and precise line positions (0.4 MHz median uncertainty) into the MARVEL (measured active vibration-rotation energy levels) analysis of the H2CO spectrum. This increases the number of MARVEL-predicted energy levels by 82 and of rovibrational transitions by 5382, and substantially reduces uncertainties of MARVEL-derived H2CO energy levels over a large range: from pure rotational levels below 200 cm−1 up to multiply excited vibrational levels at 6000 cm−1. This work is an important step toward filling the gaps in formaldehyde data in the HITRAN database