| 1. |
- Aronsson, Julia, et al.
(författare)
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Tearing of post-consumer cotton T-shirts and jeans of varying degree of wear
- 2020
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Ingår i: Journal of Engineered Fibers and Fabrics. - : Sage Publications. - 1558-9250. ; 15, s. 1-9
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Tidskriftsartikel (refereegranskat)abstract
- The demand for textile fibres is growing quickly. However, global cotton production has stabilized around 25 Mton/year. This is a sound development since cotton cultivation causes major sustainable development issues. Even if regenerated cellulose fibre production steadily grows, it is still only from a sixth to a fifth of cotton volumes. Hence, it is essential to find resource-efficient routes to generate alternatives to virgin cotton. There are many promising research initiatives that discover the possibility to utilize waste streams of neat cotton and cotton in fibre blends as raw materials for dissolving pulp for regeneration into, for example, viscose or Lyocell. However, there is a much simpler and energy-efficient route at hand. If fabrics are disintegrated mechanically, the separated fibres can be turned into yarn again. However, since fibre length is a key parameter to accomplish strong and durable textiles, fibre length loss upon tearing should be minimized. This study evaluates how fibre length distribution alters upon tearing of post-consumer cotton waste of two different constructions: denim and single jersey; and different degrees of wear, rendering four different fractions: (1) barely worn denim, (2) rather worn denim, (3) barely worn single-jersey and (4) rather worn single-jersey. Before tearing, the garments were dissembled, their yarns were characterized, fibre length distributions were manually determined for (1)–(4). Length analysis of the recovered fibres after tearing revealed that the length drop was most severe for (a) the finer single-jersey and (b) the barely worn fractions. The findings suggest that significant wear does not exclude from mechanical recycling.
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| 2. |
- Aronsson, Mora, et al.
(författare)
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Sveriges arter och naturtyper i EU:s art- och habitatdirektiv : Resultat från rapportering 2019 till EU av bevarandestatus 2013-2018
- 2020
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Sverige har en variationsrik natur med storslagen fjällmiljö, myllrande våtmarker, vattendrag och sjöar, kust och hav, skogar och odlingslandskap, alla med ett rikt växt och djurliv. Den här fantastiska biologiska mångfalden tas ofta för given och ibland som en lyx, men oavsett vilket är det en förutsättning för vår överlevnad.2019 rapporterade Sverige statusen till EU för perioden 2013–2018 för de naturtyper och arter i Sverige som är listade i art- och habitatdirektivet. Den berättar att 20 procent av naturtyperna och 40 procent av arterna mår bra. Den biologiska mångfalden är hårt trängd i såväl Sverige som i andra EU-länder.Den här rapporten sammanfattar Sveriges rapportering och innehåller beskrivningar av status för naturtyper och arter, påverkan, hot och trender. Rapporten ger kunskap om tillståndet för den biologiska mångfalden i Sverige med hjälp av de arter och naturtyper som är listade i EU:s art- och habitatdirektiv.Rapporten visar hur naturmiljöerna i Sverige förändas, och sammanfattar den senaste kunskapen om vilka faktorer som driver dessa förändringar. Även exempel på hur vi genom restaurerings- och skötselåtgärder kan hejda förlusten av biologisk mångfald tas upp.
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| 3. |
- Aronsson, Pia, 1950-
(författare)
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Det professionella projektets framväxt inom ramen för en forskningscirkel : en manipulativ eller frigörande praktik?
- 2022
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The thesis looks back on an important transitional period for the municipal social services, a transition between different social models and ideals. During this transi-tional period, in the mid-90s, there was a process of change from the community ideal to market liberalism, the latter being characterized by the client-provider model as a form of governance for the municipal organization. Users of social services were becoming customers and professionals were moving towards increased specialization and centralization of social work. The process of change within the municipal organization is a recurrent theme giving this thesis present timeliness although the process of change presented in the thesis took place almost three decades ago.The overall aim of the thesis was to contribute with in-depth knowledge of the professionals' possibilities to exert influence over a process of change in a politically controlled organization using an empirical example as a starting point. The research approach was based on the action research tradition and primarily towards critical action research.The empirical example, the research circle, where professionals met with the prac-tice of social work and the practice of research for a mutual knowledge formation became a temporary action arena where the “professional project” was developed during the years 1994 to 1996.In the thesis politically adopted policy documents are analyzed, the content of which outlined the direction for the future organization and the content of social work, the "Political Project". The analysis reveals the power relations where the political and administrative domain worked to separate and centralize social work while the professionals worked to maintain a decentralized and integrated individual and family care using new working methods and approaches such as open social counseling, group-oriented social work and city district networks as a basis for social service.The thesis shows that the professionals' influence in the process of change was limited by politically adopted decisions in accordance with the conditions of representative democracy, and that only parts of the professional project, which did not challenge overall organizational structures, could be implemented.Before future reorganizations, it is recommended that those affected by the reorganization should be involved in the process early on in order to expand the decision makers knowledge base by including the professionals' opinions, knowledge and will.The development towards a market-liberal form of organization was a lengthy process but has today become the dominant form of organization within municipal administration.
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| 4. |
- Gestrelius, Sara, 1986-
(författare)
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Optimisation models for train timetabling and marshalling yard planning
- 2022
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Railways provide high capacity, safe and energy efficient transportation of goods and passengers. However, railway transportation also suffers from intrinsic restrictions and the effectiveness and efficiency of the transportation depend on the railway actors’ ability to solve a set of hard and interconnected planning problems. As the digitalisation of rail-way planning advance, compute-intensive decision support tools could be implemented to support the planners’ work. Two support functions that would be useful are automatic generation of new plans and optimisation of existing plans. In this thesis, mathematical models are developed and analysed for optimisation of (1) train timetables and (2) marshalling yard plans. The aim is to investigate the feasibility and potential of using mixed integer linear programming (MILP) models to solve these two planning problems. To this aim, requirements and planning goals are identified and modelled as mathematical constraints and objective functions. The resulting mathematical models are then tested on realistic problem instances, and the execution times and optimised plans are analysed to determine if the mathematical models could be useful in practice.The thesis contributes with an analysis of the definition of ”good” in a railway timetable setting from the perspective of an infrastructure manager, a novel mathematical model for timetable planning, an optimisation-based heuristic for decreasing execution times and last but not least an analysis of the potential of using optimisation to enable a new type of annual capacity allocation. For marshalling yard planning, the thesis contributes with an analysis of three different mathematical models for planning one of the sub-yards of a marshalling yard, and with an extended, more comprehensive, mathematical model that can be used to plan two sub-yards. Further, a heuristic is developed for the more comprehensive problem, and the effects of optimising two sub-yards rather than one are analysed.The overall conclusion is that MILP models can contribute to improved railway planning. By using MILP optimisation, more effective plans can be made faster. However, more research is needed to reach the full potential of mathematical optimisation for railway planning problems, in particular when it comes to user experience and user interaction, but also to further decrease the execution times and extend the problem scope that can be handled.This thesis consists of two parts. The first part introduces and summarises the research. It provides background knowledge on the two planning problems as well as on mathematical optimisation, and also present the research framework and some overall conclusions and suggestions for future work. The second part of the thesis consists of five appended papers, three on train timetabling and two on marshalling yard planning.
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| 5. |
- Gestrelius, Sara, 1986-, et al.
(författare)
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Tidtabellskvalitet (TTK) : Teknisk Slutrapport
- 2020
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- KAJT projektet TTK (Tidtabellskvalitet) var ett treårigt projekt som syftade till att ta fram ett ramverk som mäter en tidtabells kvalitet. Effektmålet är bättre balanserade och därmed mer kvalitativa tidtabeller.I den här slutrapporten presenteras de resultat som togs fram under projektet. Det är dels texter baserade på litteraturstudier (kapitel 5 och delar av kapitel 7), ochs dels rapportering av resultat från workshoppar, en intervjustudie (kapitel 6) och den första implementation av ramverket (kapitel 7).Projektet undersökte kvalitetsmått för fem kvalitetsaspekter: teoretisk körbarhet, robusthet och återställningsförmåga, konkurrenshantering, reservkapacitet och ansökningsuppfyllnad. Fyra slutsatser från projektet är att:I dagens process finns det skrivna regler för teoretisk körbarhet, robusthet och tvistlösning. Övriga kvalitetsaspekter saknas det tydliga regler för, och det saknas helt stöd för att kunna väga olika kvalitetsaspekter mot varandra.Det saknas forskning på kvalitetsmått för vissa kvalitetsaspekter. När det kommer till trafik så saknas specifikt publicerade mått för reservkapacitet och konkurrenshantering, trots att dessa aspekter lyfts fram i både svensk och europeisk lagstiftning. För att kunna designa ett fullvärdigt ramverk för flermålsoptimering krävs kvalitetsmått även för dessa aspekter.I dagens planeringsprocess bedöms aspekterna teoretisk körbarhet och robusthet som viktiga. Minst viktig bedöms reservkapacitet vara. Däremot upplevs reservkapacitet som absolut svårast att jobba med.Ramverket som projektet tog fram har testats på Värmlandsbanan. Kvalitetsmätningar genomfördes för andra torsdagen i oktober för 2014-2018. I dess mätningar syns en förbättring för ett flertal mått mellan 2016 och 2017 års tidtabeller, vilket är förväntat då nya konstruktionsregler infördes 2017. Ramverket med flermålsoptimering testades på andra torsdagen i oktober 2018. Tre styrpunkter användes för att ta fram tre olika tidtabeller, varav ingen dominerar de andra. Resultatet visar att det, i alla fall i enskilda trafikdagar, finns utrymme för att generera olika pareto-optimala tidtabeller. Det vill säga, givet att man inte i förväg kan bestämma sig för vilka kvalitetsmått som är viktigast, så kan man generera ett antal tidtabeller där ingen är absolut bättre än de andra.Viktiga framtida forskningsområden är (1) att identifiera och implementera mätvärden för banarbeten i kvalitetsramverket, (2) att ta fram kvalitetsmått för de aspekter där sådana saknas, (3) att ta fram metoder för att säkerställa att tåglägen som går över flera konstruktionsområden är av god kvalitet (4) att ta fram en metod för att hantera gapet mellan teori och praktik samt (5) att undersöka olika kvalitetsmåtts effektivitet.Vidare rekommenderar vi att Trafikverket undersöker möjligheterna för att ta fram riktlinjer även för de kvalitetsaspekter som inte är teoretisk körbarhet och robusthet, samt utvecklar processer och stödverktyg som hjälper tidtabellsplanerare väga olika kvalitetsaspekter mot varandra.
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| 6. |
- Gestrelius, Sara, et al.
(författare)
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Timetable quality from the perspective of a railway infrastructure manager in a deregulated market : An interview study with Swedish practitioners
- 2020
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Ingår i: Journal of Rail Transport Planning & Management. - : Elsevier B.V.. - 2210-9706 .- 2210-9714. ; 15
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Tidskriftsartikel (refereegranskat)abstract
- Railway capacity allocation in a deregulated market requires planners to solve a mathematically complex optimization problem while simultaneously arbitrating the wants and needs of different stakeholders. This paper analyses timetable quality from the perspective of timetable planners working for the Swedish infrastructure manager Trafikverket. Seven quality aspects are discussed: feasibility, disturbance resistance, competition management, capacity safeguarding, application fulfilment, attractiveness and compatibility with surrounding planning areas. Each aspect is introduced, including references to legal documents, development projects, and research literature. Further, an interview study with eight practitioners gives insight into the current state of practice in Sweden. The practitioners consider feasibility to be both most important and easiest to handle. Capacity safeguarding is considered least important, despite its prevalence in legal documents and envisioned process developments, and is also considered hardest to handle. In general, formal rules and guidelines seem important for emphasising the importance of a quality aspect in the planning process. To better support the planners in their arbitrating role, timetable planning tools based on mathematical optimization models could be implemented. For example, support tools could be used to analyse different solutions, and could unburden the planner from working with feasibility aspects by providing automatic conflict identification and resolution.
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| 7. |
- Hedlund, Malin, et al.
(författare)
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Type I IFN system activation in newborns exposed to Ro/SSA and La/SSB autoantibodies in utero
- 2020
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Ingår i: RMD Open. - : BMJ. - 2056-5933. ; 6:1
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: In utero exposure of the fetus to Ro/La autoantibodies may lead to congenital heart block (CHB). In the mother, these autoantibodies are associated with activation of the type I interferon (IFN)-system. As maternal autoantibodies are transferred to the fetus during pregnancy, we investigated whether the type I IFN-system is activated also in newborns of anti-Ro/La positive mothers, and whether fetal IFN activation is affected by maternal immunomodulatory treatment.METHODS: Blood drawn at birth from anti-Ro/La positive mothers, their newborns and healthy control pairs was separated into plasma and peripheral blood mononuclear cells (PBMC). PBMC were analysed directly or cultured. mRNA expression was analysed by microarrays, cell surface markers by flow cytometry, and IFNα levels by immunoassays.RESULTS: We observed increased expression of IFN-regulated genes and elevated plasma IFNα levels not only in anti-Ro/La positive women, but also in their newborns. CD14+ monocytes of both anti-Ro/La positive mothers and their neonates showed increased expression of Sialic acid-binding Ig-like lectin-1, indicating cellular activation. Notably, the IFN score of neonates born to mothers receiving immunomodulatory treatment was similar to that of controls, despite persistent IFN activation in the mothers. In both maternal and neonatal PBMC, IFNα production was induced when cells were cultured with anti-Ro/La positive plasma.CONCLUSIONS: Ro/La autoantibody-exposed neonates at risk of CHB have signs of an activated immune system with an IFN signature. This study further demonstrates that neonatal cells can produce IFNα when exposed to autoantibody-containing plasma, and that maternal immunomodulatory treatment may diminish the expression of IFN-regulated genes in the fetus.
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| 8. |
- Woltjer, Rogier, et al.
(författare)
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The Future of Fighter Pilot Training? Live Virtual Constructive in Large Force Exercises : Perceived and Expected Training Value
- 2024
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Ingår i: The International Journal of Aerospace Psychology. - 2472-1840 .- 2472-1832. ; 34:1, s. 20-41
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Tidskriftsartikel (refereegranskat)abstract
- Objective: This study investigates whether and how perceived training value varies among fighter pilots participating in a large force exercise (LFE), and whether they expect Live Virtual Constructive (LVC) training to enhance training value of future LFEs.Background: LVC technology is maturing but its expected training value is under-investigated, especially regarding future LVC in LFEs.Method: Fighter pilots at a Live-flying LFE answered questionnaires, 120 responses were analyzed statistically. The questions focused on whether the sortie they just flew provided training value, generally and for specific Desired Learning Objectives (DLOs), on whether the inclusion of Virtual and Constructive entities in future LFEs would contribute to training value generally and to the DLOs specifically, and on specific LVC implementation issues.Results: Ratings of experienced training value varied across DLOs, and DLO ratings varied across Mission types. Fighter pilots were positive toward including Virtual and Constructive entities in LFEs for certain DLOs, mostly for flying a complex mission. DLOs covaried around the factors of LVC-tradeoff advantages and Live advantages, as well as temporal dimensions of planning before a mission and stages of engagement. LVC implementation lessons were extracted.Conclusion: Fighter pilots are generally moderately positive about LVC in LFEs. The measurement of perceived training value per DLO seems a relevant instrument for investigating perceived training value of an LFE and expected training value of future LVC training.
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| 9. |
- Zhang, Hongyi, 1996, et al.
(författare)
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Autonomous Navigation and Configuration of Integrated Access Backhauling for UAV Base Station Using Reinforcement Learning
- 2022
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Ingår i: Proceedings - 2022 IEEE Future Networks World Forum, FNWF 2022. - : IEEE. ; , s. 184-189, s. 184-189
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Konferensbidrag (refereegranskat)abstract
- Fast and reliable connectivity is essential to enhance situational awareness and operational efficiency for public safety mission-critical (MC) users. In emergency or disaster circumstances, where existing cellular network coverage and capacity may not be available to meet MC communication demands, deployable-network-based solutions such as cells-on-wheels/wings can be utilized swiftly to ensure reliable connection for MC users. In this paper, we consider a scenario where a macro base station (BS) is destroyed due to a natural disaster and an unmanned aerial vehicle carrying BS (UAV-BS) is set up to provide temporary coverage for users in the disaster area. The UAV-BS is integrated into the mobile network using the 5G integrated access and backhaul (IAB) technology. We propose a framework and signalling procedure for applying machine learning to this use case. A deep reinforcement learning algorithm is designed to jointly optimize the access and backhaul antenna tilt as well as the three-dimensional location of the UAV-BS in order to best serve the on-ground MC users while maintaining a good backhaul connection. Our result shows that the proposed algorithm can autonomously navigate and configure the UAV-BS to improve the throughput and reduce the drop rate of MC users.
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| 10. |
- Zhang, Hongyi, 1996, et al.
(författare)
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Deep Reinforcement Learning for Multiple Agents in a Decentralized Architecture: A Case Study in the Telecommunication Domain
- 2023
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Ingår i: Proceedings - IEEE 20th International Conference on Software Architecture Companion, ICSA-C 2023. - : IEEE COMPUTER SOC. ; , s. 183-186
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Konferensbidrag (refereegranskat)abstract
- Deep reinforcement learning has made significant development in recent years, and it is currently applied not only in simulators and games but also in embedded systems. However, when implemented in a real-world context, reinforcement learning is frequently shown to be unstable and incapable of adapting to realistic situations, particularly when directing a large number of agents. In this paper, we develop a decentralized architecture for reinforcement learning to allow multiple agents to learn optimal control policies on their own devices of the same kind but in varied environments. For such multiple agents, the traditional centralized learning algorithm usually requires a costly or time-consuming effort to develop the best-regulating policy and is incapable of scaling to a large-scale system. To address this issue, we propose a decentralized reinforcement learning algorithm (DecRL) and information exchange scheme for each individual device, in which each agent shares the individual learning experience and information with other agents based on local model training. We incorporate the algorithm into each agent in the proposed collaborative architecture and validate it in the telecommunication domain under emergency conditions, in which a macro base station (BS) is broken due to a natural disaster, and three unmanned aerial vehicles carrying BSs (UAV-BSs) are deployed to provide temporary coverage for mission-critical (MC) users in the disaster area. Based on the findings, we show that the proposed decentralized reinforcement learning algorithm can successfully support multi-agent learning, while the learning speed and service quality can be further enhanced.
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