Publikationer från Linköpings universitet
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Temporär legalitet : Reglering av asyl genom bostad och utbildning i den svenska välfärdsstaten
No full textThis thesis examines the shift towards temporary protection for refugees in Sweden since 2016 and its implications for access to permanent residency and family reunification. Situated at the intersection of welfare law and critical border studies, the thesis conceptualises this shift and its implications in terms of ‘temporary legality’: a prevailing condition of asylum marked by legal conditionality and protracted deportability. Drawing on research on borders, racialisation, and neoliberal welfare reforms, it analyses how spatial, temporal, and racial dimensions converge in shaping this condition. The thesis examines residence-permit requirements tied to housing and education to show how such requirements function as internal borders that are negotiated across and within municipalities, revealing how migration law is enacted through welfare institutions. Methodologically, it adopts a socio-legal lens to trace migration law beyond the Migration Agency and the courts into welfare sites, foregrounding the municipality as a bordering space. The analysis draws on 31 interviews with welfare practitioners, local politicians, and civil society actors, complemented by policy documents, court cases, and press material. The analysis shows clearly that temporary legality produces a fluctuating space between legality and illegality, delegated to welfare practitioners to regulate. In such a space, municipal discretion, enacted through local policies and everyday practices, contests, cushions, or exacerbates migration law, generating locally differentiated status trajectories for individuals in need of protection. It is within such a condition, the thesis argues, that residence-permit requirements operate as internal borders, producing uneven and racialised access to welfare rights, family reunification, and permanent status. That is, by governing asylum through temporary legality, the Swedish state creates protracted forms of uncertainty and differentiates and dismantles the right to asylum
Governing Mobility Through Exemptions: Cross-National Dependencies, Immigration Policy, and Migrant Labour in South African Historical Perspective
No full textOver the last century, the South African state has periodically engaged in the practice of 'exempting' various migrants from their otherwise irregular immigration statuses. Always backed by official legislation, exemptions represent one way by which dominant capitalist interests have relied on the legitimacy of the state to meet their labour needs by sometimes employing undocumented migrants from the Southern African region. Through insights from sub-imperialism and bordering, this paper discusses historical case examples from policy articulations, parliamentary debates, secondary literature and archival materials. By exploring cross-national relationships of exploitation and differentiation, the paper argues that exemptions should be understood as attempts by which the contradictions of ubiquitous informal cross-border mobility and employment in a regime of unfree regional movement might be resolved. Exemptions also attest to the challenge of governing human mobility in a region invested with a historically vast infrastructure of producing, attracting as well as exploiting cheap migrant labour.Funding Agencies|Kungliga Vetenskapsakademien [LH2017-0028]; REMESO</p
Route Planning for UAVs : A Column Generation Approach
No full textWe study an integer optimization problem that describes the route planning for UAVs (unmanned aerial vehicles). The aim in the route planning problem is to minimize the number of UAVs that monitors the locations in a region within specific visiting times. The challenge is to find travelling salesman routes that satisfy the criteria for how often the locations should be monitored. The main purpose of this work is to apply column generation to this route planning problem, based on three strategies. The interest in this approach is to evaluate how effective each strategy is to solve the problem and then conclude its advantages and disadvantages. The strategies that are being presented in this work, are exact column generation, heuristic column generation and ad hoc column generation. We present algorithms for each strategy and study its behavior on different problem instances. The implementations have been performed in the programming language Python with the use of the optimization solver Gurobi.I denna rapport studerar vi ett heltalsproblem som beskriver ruttplanering av UAVs (unmanned aerial vehicles). Målet i ruttplaneringsproblemet är att minimera antal UAVs som bevakar platserna i ett område inom specifika besökstider. Utmaningen är att finna TSP-turer som uppfyller kriterierna för hur ofta dessa platser får bevakas. Huvudsyftet med detta arbete är att använda kolumngenerering på ruttplaneringsproblemet baserad på tre strategier. Intresset i detta angripningssätt är att utvärdera hur effektiv varje metod är för att lösa problemet och diskuteraderas för- och nackdelar. De strategier som presenteras i detta arbete, är exakt kolumngenerering, heuristisk kolumngenerering och ad hoc kolumngenerering. Vi presenterar algoritmerna för varje strategi och studerar deras beteenden på olika probleminstanser. Implementationerna har utförts i programmeringsspråket Python med användning av optimeringslösaren Gurobi.
Towards sustainable perovskite light-emitting diodes
No full textPerovskite light-emitting diodes (PeLEDs) are advancing to become the frontrunner candidates for the next generation of lighting and display technologies. However, despite rapid technical development, a thorough understanding of PeLEDs’ environmental and economic impacts—essential information for future commercialization—is currently lacking. Here we assess the environmental and economic performance of 18 representative PeLEDs, aiming to identify effective industrial techniques to develop sustainable PeLEDs from a life-cycle perspective. We find that, like mature organic LEDs, PeLEDs show excellent environmental performance. In addition, we demonstrate that lead is not a major source of toxicity from PeLEDs. We estimate that, to commercialize PeLEDs and improve their sustainability, their lifetime should reach the order of 10,000 hours to compensate for the relative environmental impacts. The techno-economic assessment indicates that the cost of future PeLEDs will probably be in the vicinity of US$100 m–2, comparable to that of commercial organic LED panels. Overall, this study shows the potential of PeLEDs as next-generation lighting technology from environmental, economic and technical perspectives, providing insights relevant to their future development.Funding Agencies|National Natural Science Foundation of China; Marianne and Marcus Wallenberg Foundation; Knut and Alice Wallenberg Foundation; Knut and Alice Wallenberg Foundation (Wallenberg Initiative Materials Science for Sustainability WISE); Swedish Research Council Vetenskapsradet; Swedish Energy Agency; Swedish Government Strategic Research Area in Materials Science on Functional Materials at Linkoeping University (faculty grant SFO-Mat-LiU) [2009-00971]; Olle Engkvists Stiftelse; Shandong Provincial Natural Science Foundation [ZR2021QG044]; Society of Vacuum Coaters Foundation (USA); Young Scholars Program of Shandong University (Weihai); Centre in Nano Science and Technology (CeNano) at Linkoping University; [NSFC 72222014]; [72348001]; [MMW 2023.0077]; [KAW 2019.0082]; [2021-06668]; [P2022-00394]</p
Extending partial edge colorings of Cartesian products of graphs
No full textWe consider the problem of extending partial edge colorings of Cartesian products of graphs. More specifically, we suggest the following Evans -type conjecture. If G is a graph where every precoloring of at most k precolored edges can be extended to a proper chi 0(G)-edge coloring, then every precoloring of at most k + 1 edges of G ?K2 is extendable to a proper (chi'(G) + 1)edge coloring of G ?K2. In this paper we verify that this conjecture holds for trees, complete and complete bipartite graphs, as well as for graphs with small maximum degree. We also prove versions of the conjecture for general regular graphs where the precolored edges are required to be independent.Funding Agencies|Swedish Research council VR [2017-05077]; International Science Program in Uppsala, Sweden</p
Fe-based Polarizing Multilayer Neutron Optics
No full textThis thesis explores innovative strategies to improve Fe-based polarizing multilayer neutron optics, a cornerstone technology for neutron scattering used to investigate materials at the atomic and molecular levels. Polarization analysis plays a crucial role in uncovering insights into magnetic domain structures, molecular orientations, and protein shapes, enabling breakthroughs in materials science, physics, biology, chemistry, and cultural heritage. However, the performance of conventional multilayer optics, such as Fe/Si systems, is hindered by challenges including low reflectivity due to rough interfaces, reduced polarization caused by scattering length density (SLD) mismatches, spin-flip scattering arising from magnetic inhomogeneities, and difficulties in achieving uniform magnetic behavior, to name a few. These challenges become increasingly critical at higher scattering angles or vectors, where thinner and smoother layers are essential for high performance. This work introduces isotope-enriched boron carbide (11B4C) as a key material to address these limitations, demonstrating its versatility through two main approaches: as interlayers and as a mixed component within Fe and/or the non-magnetic layers. Initial studies focused on Fe/11B4CTi multilayers, which outperformed traditional Fe/Si systems in both reflectivity and polarization. The incorporation of 11B4C reduced interface widths, as evidenced by sharper Bragg peaks in X-ray reflectivity measurements, and enabled polarization improvements from 61% to 78% for multilayers with 25 Å bilayer thicknesses and 20 periods. These enhancements were driven by better SLD tuning, through compositional variations, and smoother interfaces, showcasing the potential of 11B4C to optimize multilayer performance. Further studies explored the use of 11B4C as interlayers in Fe/Si multilayers, resulting in significant performance gains. Interface widths were reduced from 9.5 Å to 5.2 Å, leading to a 125% increase in reflectivity and 15% higher polarization for multilayers with a period thickness of 15 Å and 80 periods. Acting as a barrier between Fe and Si layers, the 11B4C interlayers improved interface smoothness, suppressed intermixing, and maintained the structural and magnetic integrity of the multilayers. The most significant advancements were achieved in multilayers where 11B4C was mixed into both Fe and Si layers. In these systems, the amorphization effect of 11B4C eliminated lateral structural correlations and magnetic coercivity, and at the same time drastically reducing spin-flip scattering. These modifications allowed the multilayers to operate at much lower external magnetic fields, making them more efficient, practical and enables possibilities of new experimental setups. Magnetic off-specular polarized neutron reflectometry (PNR) and muon spin spectroscopy measurements confirmed the uniform magnetic behavior of Fe/Si + 11B4C-containing multilayers, showing the suppression of magnetic domains even at low magnetic fields. The ability to stabilize magnetic properties and enhance polarization performance underscores the significant impact of this approach. Additionally, the tunability of 11B4C concentrations enabled precise control over magnetic properties such as coercivity and interlayer exchange coupling. Vibrating sample magnetometry and PNR measurements revealed the emergence of low-field antiferromagnetic coupling and demonstrated how multilayer properties could be tailored for specific applications. These findings highlight the versatility of 11B4C as both a structural and magnetic modifier in multilayer systems. This thesis establishes 11B4C as a highly effective material for Fe-based polarizing neutron optics, addressing critical challenges by improving reflectivity and polarization, reducing spin-flip scattering, and enabling better control of magnetic properties. By overcoming these limitations, 11B4C expands the capabilities of neutron scattering techniques, paving the way for advancements in materials science, magnetism, and beyond.Funding: VR, Hans Werthén grant, by the Royal Academy of Engineering Sciences 2022-D-03, the Royal Academy of Sciences Physics grant PH2022-0029, the Clark and Karen Bright Endowed Scholarship Honoring Angus Macleod from the Society of Vacuum Coaters grant, the Stiftelsen Lart Hiertas Minne grant (FO2022-0273), the Swedish Neutron Scattering Society grant and the Längmanska Kulturfonden grant (BA23-1664).</p
Navigating Stronger Evidence : Unobservable Processes and Causal Mechanisms in Social Trajectories
No full textThis dissertation explores the interplay between statistical causal inference and mechanism-based explanations in analytical sociology, focusing on the challenge of unobservable processes and their implications for robust causal explanations. Analytical sociology emphasizes the importance of mechanisms in understanding social phenomena but often grapples with the integration of statistical causal inference methods. By combining two prominent frameworks—the structural causal model (SCM) and the potential outcomes approach (PO)—this work bridges gaps in addressing unmeasured confounders and alternative mechanisms. It contributes to the advancement of theory-driven causal inference by emphasizing evidential pluralism and triangulation, integrating diverse forms of evidence to enhance the validity of causal claims. The dissertation comprises three empirical papers, each addressing a critical research question. Paper 1 investigates the mediating role of disadvantaged neighborhoods in social assistance dependency in Sweden. Using Swedish register data, it identifies pathways linking early social assistance usage, neighborhood disadvantage, and long-term dependency. Results indicate that disadvantaged neighborhoods play a central mediating role, especially for individuals at high risk of early social assistance, highlighting the interplay of contextual and individual-level mechanisms. Paper 2 examines the relationship between homeownership and unemployment, exploring temporal dynamics and effect heterogeneity across migration backgrounds, education levels, and neighborhood characteristics. Employing advanced causal inference methods, the study finds that homeownership provides protective effects against unemployment, with stronger effects observed for immigrant homeowners. These findings underscore the nuanced, context-specific mechanisms underlying the homeownership-unemployment nexus. Paper 3 addresses the role of unmeasured confounders in neighborhood selection and broader sociological research. Through a scoping review and an expanded sensitivity analysis framework, this paper demonstrates the importance of assessing potential biases and alternative explanations in causal studies. It provides methodological guidance for evaluating the impact of unobservable processes across different empirical settings. Together, these papers as main cases advance analytical sociology by integrating statistical causal inference and mechanistic reasoning to provide robust, theory-driven explanations of complex social phenomena. By addressing unobservable processes and emphasizing evidential pluralism, this dissertation contributes to the development of more comprehensive and context-sensitive sociological insights.Funding agency: The Swedish Research Council (VR): dnr. 2013-07681 and 2019-00245</p
From Product to Product-as-a-Service Designing: Challenges and Opportunities
No full textReview:Has not been peer-reviewedFunding:This research is in part supported by the RE:think (Rethink and improve product design and service cost for circular economy business models) project, a part of the RE:SOURCE innovation program, funded by Energimyndigheten (Swedish Energy Agency) (Project Number P2022-00342). The RE:SOURCE innovation program is financed by Vinnova, Energimyndigheten and Formas. The writing of this brief was financially supported by the RE:think project.</p
Navigating Digital Transformation: Managing Change in Complex Products and Systems : An Industry 4.0 Case Study in Aircraft Manufacturing
No full textThe CoPS industry is facing a major challenge: using Industry 4.0 (I4.0) technologies, such as smart automation and data-driven production, to transform manufacturing. However, the journey to digital integration is filled with obstacles, especially when it comes to managing the necessary human and organizational changes. This master’s thesis explores the complexities of implementing I4.0 in aircraft manufacturing, with a focus on change management. The study looks at two Saab projects: the T-7 greenfield project, a new facility in West Lafayette, for the T-7A Red Hawk, and the AS Digi brownfield project, which improves existing production systems in Sweden. The research uses semi-structured interviews with Saab employees and thematic analysis of the data. The study addresses three main questions: Why do CoPS firms adopt I4.0? What challenges arise during implementation? And how does I4.0 change the way organizations manage change? The findings show that Saab’s move toward I4.0 was driven by the need to improve efficiency, stay competitive, and become a digital leader in an industry with long product lifecycle and strict regulations. The T-7 project aimed to set a new standard for aerospace manufacturing, while the AS Digi project focused on updating older processes. However, they ran into several challenges, including building a new facility, setting up new IT systems, and training a largely new workforce. Additionally, cultural and competence gaps between Swedish and American teams, high employee turnover, and external disruptions like COVID-19 and geographical issues complicated progress. The projects faced resistance to new workflows and difficulties adapting old practices to digital systems. These challenges highlight the complex nature of implementing I4.0 in Complex Product Systems, where technical innovation needs to align with human and organizational changes. I4.0 significantly changes the way organizations manage change. It speeds up transformation, broadens the scope to include technology and infrastructure, and raises the skill requirements for the workforce. Traditional change management models, like Kotter’s eight-step process or Lewin’s unfreeze-change-refreeze framework, do not work well in the context of I4.0. In I4.0, change happens continuously, and coordination across disciplines is critical. This thesis proposes a new, refined change management model for I4.0 in CoPS. The thesis provides several recommendations for CoPS firms, including adopting the proposed model to guide I4.0 initiatives, stabilizing core operations before implementing advanced tools, fostering cultural awareness to address Swedish-American team differences, and standardizing I4.0 processes for consistency across projects. This study emphasize the understanding of I4.0 implementation in CoPS and emphasizes the need for adaptive, systemic change management strategies that integrate both technology and human factors. However, the study’s focus on a single company and reliance on qualitative data limit its generalizability. Future research could explore cultural influences, resilience to external disruptions, cross-site collaboration in global firms, and testing the proposed model in real-world settings. By offering a practical framework and actionable insights, this thesis aim to help CoPS firms navigate the challenges of digital transformation and drive innovation in a rapidly changing industry
My Kingdom for a Pony: Heritability of Withers Height in Connemara Ponies
No full textHeight at the withers is an important conformational aspect in horses, determining competition class and whether a purebred meets the breed standard. Knowing the narrow-sense heritability (h2) can support breeding for the desired height, as heritability varies between breeds. Connemaras are a large pony breed that sometimes exceed pony height (148 cm), affecting market value. This study estimates the heritability of height at the withers in Connemaras. A dataset comprising of 3030 height measurements as well as parent identity was used. Heritability was estimated for midparent-, dam- and sire-offspring using two models: a linear mixed model and a simple linear regression. Height distribution, sex differences and temporal trends from 1975-2015 were also analysed. The mixed model produced a moderate heritability estimate for midparent-offspring, with dam-offspring estimates notably higher and sireoffspring lower, both with smaller standard errors. Compared to this, the simple model gave higher estimates for midparent- and sire-offspring, but a slightly lower estimate for damoffspring, and had larger standard errors for single parent-offspring estimates. Greater maternal contribution is likely due to maternal effects and a shared environment. The inconsistency of sire-offspring estimates, and large standard error may be due to a smaller sample size as well as the simple model inflating heritability due to an inability to account for other sources of variation. The mixed model provided more internally consistent estimates, and the midparentoffspring result aligns with findings in other breeds with moderate heritability