| 1. |
- Björklund, Henrik, et al.
(author)
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Compression of finite-state automata through failure transitions
- 2014
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In: Theoretical Computer Science. - : Elsevier. - 0304-3975 .- 1879-2294. ; 557, s. 87-100
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Journal article (peer-reviewed)abstract
- Several linear-time algorithms for automata-based pattern matching rely on failure transitions for efficient back-tracking. Like epsilon transitions, failure transition do not consume input symbols, but unlike them, they may only be taken when no other transition is applicable. At a semantic level, this conveniently models catch-all clauses and allows for compact language representation.This work investigates the transition-reduction problem for deterministic finite-state automata (DFA). The input is a DFA A and an integer k. The question is whether k or more transitions can be saved by replacing regular transitions with failure transitions. We show that while the problem is NP-complete, there are approximation techniques and heuristics that mitigate the computational complexity. We conclude by demonstrating the computational difficulty of two related minimisation problems, thereby cancelling the ongoing search for efficient algorithms.
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| 2. |
- Westblad, Niklas, et al.
(author)
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The Effect of Autoregulated Flywheel and Traditional Strength Training on Training Load Progression and Motor Skill Performance in Youth Athletes.
- 2021
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In: International Journal of Environmental Research and Public Health. - : MDPI. - 1661-7827 .- 1660-4601. ; 18:7
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Journal article (peer-reviewed)abstract
- BACKGROUND: The effects of flywheel resistance training (FRT) on youth are relatively unknown. The aim of this study was to compare the effects of autoregulated FRT with traditional strength training (TST) on jumping, running performance and resistance training load progression in youth athletes. Thirty youth athletes (11.8 ± 0.9 yr) were matched for peak height velocity (PHV) status and block-randomised into two groups: FRT (n = 15, PHV -0.8 ± 1.6) and TST (n = 15, PHV -0.8 ± 1.5). Twelve resistance training sessions over a six-week intervention with flywheel or barbell squats were performed using autoregulated load prescription. Squat jump (SJ); countermovement jump (CMJ); and 10 m, 20 m and 30 m sprints were assessed pre- and post-intervention. The external load increased similarly for FRT and TST (z = 3.8, p = 0.06). SJ increased for both groups (p < 0.05) but running performance was unaffected (p > 0.05).CONCLUSIONS: FRT resulted in similar load progression and motor skill development in youth athletes as TST, but the perceived exertion was less. Autoregulation is a practical method for adjusting training load during FRT and should be considered as an alternative to autoregulated TST.
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| 3. |
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| 4. |
- Björklund, Camilla, 1977, et al.
(author)
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Pattern discernment and pseudo-conceptual development in early childhood mathematics education
- 2014
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In: International Journal of Early Years Education. - : Informa UK Limited. - 0966-9760 .- 1469-8463. ; 22:1, s. 89-104
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Journal article (peer-reviewed)abstract
- In this empirical study, we investigate an early childhood education activity in mathematics on the concept of ‘pattern’. The children participating in the study attend an intermediate form of schooling in Sweden called ‘the preschool class for six-year-olds’, intended to facilitate their transition from preschool to school. Following a prolonged activity over 45 minutes, we analyse for what the children are supported in discerning and what they give as evidence of having discerned in and about patterns. The theoretical point of departure is variation theory, conceptualising learning as increased discernment. The results show that in terms of the important Vygotskian distinction between ‘pseudo concepts’ and ‘concepts (proper)’, the children's discernment and what they are supported in discerning are of the former kind. Pseudo concepts are discussed as integral to the institutional form of the preschool class and premised to be important to the child's further conceptual development.
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| 5. |
- Björklund, Johanna, et al.
(author)
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An efficient best-trees algorithm for weighted tree automata over the tropical semiring
- 2015
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In: Proc. 9th International Conference on Language and Automata Theory and Applications. - Cham : Springer. ; , s. 97-108
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Conference paper (peer-reviewed)abstract
- We generalise a search algorithm by Mohri and Riley from strings to trees. The original algorithm takes as input a weighted automaton M over the tropical semiring, together with an integer N, and outputs N strings of minimal weight with respect to M. In our setting, M defines a weighted tree language, again over the tropical semiring, and the output is a set of N trees with minimal weight. We prove that the algorithm is correct, and that its time complexity is a low polynomial in N and the relevant size parameters of M.
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| 6. |
- Björklund, Johanna, et al.
(author)
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Efficient enumeration of weighted tree languages over the tropical semiring
- 2019
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In: Journal of computer and system sciences (Print). - : Elsevier BV. - 0022-0000 .- 1090-2724. ; 104, s. 119-130
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Journal article (peer-reviewed)abstract
- We generalise a search algorithm by Mohri and Riley from strings to trees. The original algorithm takes as input a nondeterministic weighted automaton M over the tropical semiring and an integer N, and outputs N strings of minimal weight with respect to M. In our setting, M is a weighted tree automaton, again over the tropical semiring, and the output is a set of N trees with minimal weight in this language. We prove that the algorithm is correct, and that its time complexity is a low polynomial in N and the relevant size parameters of M.
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| 7. |
- Björklund, Johanna, et al.
(author)
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Syntactic methods for topic-independent authorship attribution
- 2017
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In: Natural Language Engineering. - : CAMBRIDGE UNIV PRESS. - 1351-3249 .- 1469-8110. ; 23:5, s. 789-806
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Journal article (peer-reviewed)abstract
- The efficacy of syntactic features for topic-independent authorship attribution is evaluated, taking a feature set of frequencies of words and punctuation marks as baseline. The features are 'deep' in the sense that they are derived by parsing the subject texts, in contrast to 'shallow' syntactic features for which a part-of-speech analysis is enough. The experiments are made on two corpora of online texts and one corpus of novels written around the year 1900. The classification tasks include classical closed-world authorship attribution, identification of separate texts among the works of one author, and cross-topic authorship attribution. In the first tasks, the feature sets were fairly evenly matched, but for the last task, the syntax-based feature set outperformed the baseline feature set. These results suggest that, compared to lexical features, syntactic features are more robust to changes in topic.
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| 8. |
- Björklund, Mattias, 1971-
(author)
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Beyond Moral Teaching : Financial Literacy as Citizenship Education
- 2021
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Doctoral thesis (other academic/artistic)abstract
- This thesis explores what financial literacy is, what financial literacy becomes and what financial literacy could become within the context of a citizenship education such as the Swedish upper secondary subject of social studies. Financial literacy does not intuitively converge with social sciences which leaves social studies teachers to both teach and realise financial literacy. Thus, teachers become co-creators of financial literacy as a school subject. This thesis explores this process via two different studies resulting in four research articles. In the first study, semi-structured interviews – analysed through PCK – are used to explore the perceptions of Swedish social studies teachers in upper secondary school regarding financial literacy teaching and learning. The findings include differences between experienced and novice teachers regarding which content knowledge and pedagogical approaches they use. However, all teachers express difficulties fitting financial literacy into social studies, mainly due to a perception of financial literacy primarily being a private matter, along with the unclear relationship between financial and societal issues. The second study is designed as a financial literacy teaching intervention. Students’ views on a financial dilemma are analysed using citizenship conceptions and threshold concepts. The findings are used to discuss design principles for financial literacy teaching. Salient conclusions in the thesis include citizenship education being able to frame financial literacy and provide epistemic features which can make financial literacy more teachable and learnable. It is hoped that the results from this thesis can inform future financial literacy teaching design as well as policy discussion related to financial literacy teaching and learning contextualised with another subject, especially citizenship education.
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| 9. |
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| 10. |
- Björklund, Maria, et al.
(author)
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Kunskapsdelning för grönare logistik, erfarenheter från ett dyadiskt samarbete
- 2024
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In: Sammanställning av referat från Transportforum 2024. - Linköping : Statens väg- och transportforskningsinstitut. ; , s. 376-377
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Conference paper (other academic/artistic)abstract
- Kunskapsdelning mellan aktörer i försörjningskedjor är en viktig möjliggörare för grönare logistik. Flertalet studier framhäver vikten av kunskapsdelning vid exempelvis implementering av grön fordonsteknik, alternativa bränslen, transportslagsbyte och elektriska fordon utan att gå djupare in på vad kunskapsutbytet innebär. I studien har vi strävat efter att besvara frågor av karaktären: Vad är det för sorts kunskap som utbytes?Vilka (ex titlar) spelar centrala roller vid kunskapsutbytet?Hur sker kunskapsutbytandet? I en tvåårig observationsstudie har vi följt ett tjugotal 2-4h möten mellan ett logistikföretag och en transportköpare. Målet med mötena var att identifiera hur de tillsammans kan nå kundens mål, att bli fossilfria till 2023. Den longitudinella ansatsen har även möjliggjort att vi kunnat se förändringar över tid. Ett ramverk baserat på litteratur kring kunskapsutbyte skapades bestående av olika typer (ex. enklare eller komplexare kunskap) och former (ex. vem som ger och vem som får kunskap) av kunskapsutbyte. I empirin fann vi sedan ett starkt fokus på management-orienterad kunskap och utbyte av enklare information. Femton personer närvarade vid mötena vilket visar att samverkan krävde kunskap från individer med olika erfarenheter och ansvarsområden. Det longitudinella perspektivet visar att en del kunskap som var relativt komplex såsom sätt att definiera fossilfri blev enklare när en samsyn uppnåtts. Logistikföretaget hade mest kunskap att donera, samtidigt som det logistikköpande företaget styrde mötena och dialogen. Medan logistikköparen fick en fördjupad förståelse för potentialerna och konsekvenserna i olika potentiella åtgärder, erhöll logistikföretaget djupare insikter kring köparens prioriteringar och förändringsmöjligheter. Tre områden fokuserades i kunskapsutbytet: prestationsstyrning (för att tydliggöra utvecklingen och strävan mot satta mål), olika gröna satsningar (ex. elbilar, HVO1000 och gröna leveransfönster). En tredje aspekt blev med tiden allt tydligare: att de tillsammans blev alltmer beroende av andra aktörer för att erhålla nödvändiga kunskaper. Studien tydliggör den komplexitet som finns i kunskapsutbytet mellan dessa båda aktörer och hur kunskapsutbytet varierar över tid och hur det är beroende av de medverkande i mötet. Studien visar även på att båda aktörerna har kunskap som måste delas för att kunna identifiera de mest framgångsrika lösningarnai deras unika kontext.
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