Publikationer från Linköpings universitet
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The Effect of COVID-19 on Subjective Financial Well-Being
No full textWe conducted two studies investigating how financial well-being was affected by the COVID-19 outbreak. Across both studies conducted in Sweden, we find that COVID-19 was associated with an overall improvement in subjective financial well-being. The positive effect was driven by a general decline in anxiety toward current financial matters, while financial security with regard to the future declined (Study 1) or was unaffected (Study 2). These results might seem paradoxical. But we propose two explanations: (a) People have a limited ability to worry about two things at the same time. Financial problems might therefore be less emotionally salient in the face of more urgent nonfinancial problems and (b) Some people likely experienced an initial slack in their household finances due to decreased spending opportunities at the onset of COVID-19, which to some extent could counteract increased worry about future financial security
Improving Event Aggregation in Automation of Software Development Workflows
No full textModern CI/CD systems produce vast streams of events that reflect the state and progression of software development processes. Aggregating these events is essential for enabling automation and traceability. In this context, aggregation refers to the process of detecting and grouping sequences of events into higher-level constructs based on predefined rules. This thesis investigates alternative mechanisms for event aggregation, with a focus on graph-based approaches within the Eiffel framework. By representing events and their relationships as a property graph, our proposed system enables declarative specification of patterns and supports incremental detection using trigger-based mechanisms in graph databases. The work implements and evaluates multiple aggregation systems, including graph databases and a complex event processing engine, and compares them based on throughput and resource efficiency under high workloads, using historical Eiffel data. The evaluation includes three different potential event aggregation systems: Neo4j, Memgraph, and Apache Flink. The results show that both Memgraph and Flink exhibit significant limitations in terms of performance and functionality for the use case, and are ultimately deemed unsuitable. Neo4j, on the other hand, provide a more promising foundation for implementing graph-based pattern matching. The findings show that Neo4j enables flexible event aggregation whilst simplifying rule definition. However, performance degrades significantly when the number of active triggers increase. Addressing this scalability limitation remains an open challenge
Oral cross-group presentations as a method for individual group work assessment : teachers’ and students’ actions that enable or hinder evidence of students’ individual knowledge
No full textGroup work assessment is described by teachers as challenging, especially assessing individual students’ knowledge developed in group work (i.e. individual group work assessment) since it entails a procedure of discerning each student’s knowledge from the group’s collective process. The aim of this study is to increase knowledge of how upper secondary teachers’ actions enable or hinder their collection of evidence for individual group work assessment of students. Particularly, the study investigates how individual oral cross-group presentations can be used to assess students’ individual knowledge developed in group work. Data consists of 23 video recordings from upper secondary teachers’ assessment of oral presentations in cross-groups followed by six interviews with the participating teachers. Data has been analysed using reflexive thematic analysis in which three themes were constructed: (a) Teachers’ frames that enable or hinder collection of evidence, (b) interactions that enable or hinder teachers’ collection of evidence, and (c) students’ behaviours that hinder collection of evidence. The results illustrate the importance of interaction by implementing the method of cross-group presentations by being active as a teacher, asking questions, and giving reflections. Interaction may enable reliable evidence that goes beyond students’ boundness to manuscripts. Potential hinders for teachers to collect evidence of students’ individual knowledge using cross-group presentations are aspects such as having enough time for presentations and interactions to enable sufficient evidence or students’ nervousness and silence that may hinder students from demonstrating their knowledge.Funding Agencies|Linkoping University; Swedish Research Council [VR 721 2012-5476]</p
The unfulfilled potential of dogs in studying behavioural ecology and evolution during the Anthropocene
No full textDogs have the potential to be an exceptional resource for studying ecological, behavioural and evolutionary processes. However, several widespread misconceptions limit our understanding of dog behaviour and inhibit the use of dogs as model systems in diverse areas of biological science. These include extensive anthropomorphization of dog behaviour, a profound bias towards almost exclusively studying pet dogs, a widespread belief that dog domestication was human-driven, and that the majority of dogs are not subjects of natural selection. Here we argue that dogs should be studied using species-general fundamental principles of ecology and evolution, and that the focus in dog research should shift towards free-ranging dogs, which comprise ca. 80% of the global dog population. By reviewing the available literature on free-ranging dog behavioural ecology we place the dog within an objective biological framework. We find that free-ranging dog populations express substantial variation in their behavioural ecology across their global range and propose that this variation is key to understanding dogs' great success in the rapidly developing anthropogenic niche. Since free-ranging dogs have a global distribution across various environmental gradients, including urbanization, climate and social structures, they provide an ideal opportunity to collect comparable, large-scale data across populations. Combined with in-depth knowledge of dog evolutionary history and the advanced genetic tools specifically developed using this species, dogs can be an outstanding model for the study of behavioural ecology and evolution
Optimization of resource-aware parallel and distributed computing: a review
No full textThis paper presents a review of state-of-the-art solutions concerning the optimization of computing in the field of parallel and distributed systems. Firstly, we contribute by identifying resources and quality metrics in this context including servers, network interconnects, storage systems, computational devices as well as execution time/performance, energy, security, and error vulnerability, respectively. We subsequently identify commonly used problem formulations and algorithms for integer linear programming, greedy algorithms, dynamic programming, genetic algorithms, particle swarm optimization, ant colony optimization, game theory, and reinforcement learning. Afterward, we characterize frequently considered optimization problems by stating these terms in domains such as data centers, cloud, fog, blockchain, high performance, and volunteer computing. Based on the extensive analysis, we identify how particular resources and corresponding quality metrics are considered in these domains and which problem formulations are used for which system types, either parallel or distributed environments. This allows us to formulate open research problems and challenges in this field and analyze research interest in problem formulations/domains in recent years.Funding Agencies|CERCIRAS COST Action - COST Association [CA19135]</p
Perovskite Solar Cells and Light Emitting Diodes: Materials Chemistry, Device Physics and Relationship
No full textSolution-processed perovskite solar cells (PSCs) and perovskite light emitting diodes (PeLEDs) represent promising next-generation optoelectronic technologies. This Review summarizes recent advancements in the application of metal halide perovskite materials for PSC and PeLED devices to address the efficiency, stability and scalability issues. Emphasis is placed on material chemistry strategies used to control and engineer the composition, deposition process, interface and micro-nanostructure in solution-processed perovskite films, leading to high-quality crystalline thin films for optimal device performance. Furthermore, we retrospectively compare the device physics of PSCs and PeLEDs, their working principles and their energy loss mechanisms, examining the similarities and differences between the two types of devices. The reciprocity relationship suggests that a great PSC should also be a great PeLED, motivating the search for interconverting photoelectric bifunctional devices with maximum radiative recombination and negligible non-radiative recombination. Specific requirements of PSCs and PeLEDs in terms of bandgap, thickness, band alignment and charge transport to achieve this target are discussed in detail. Further challenges and issues are also illustrated, together with prospects for future development. Understanding these fundamentals, embracing recent breakthroughs and exploring future prospects pave the way toward the rational design and development of high-performance PSC and PeLED devices.Funding Agencies|Nanchang Hangkong University [22379045, 22461142139]; National Natural Science Foundation of China [2019ZT08L075, 2019QN01L118, 2021A1515012545, 2024A1515011154]; Guangdong Science and Technology [20242BAB20026]; Jiangxi Provincial Natural Science Foundation [20244BCE52090]; Training Project for Early Career Youth Scientific and Technical Talent in Jiangxi Province; Nanchang Hangkong University; MacDiarmid Institute of Advanced Materials and Nanotechnology; Dodd-Walls Centre for Photonic and Quantum Technologies [2021B1515020028]; Guangdong Basic and Applied Basic Research Foundation for Distinguished Young Scholar [2023A0505020011]; Guangdong Basic and Applied Basic Research Foundation</p
"Vi lär inte för skolan utan för livet" : En kvalitativ intervjustudie av undervisning om pengars värde i anpassad grundskola
No full textUnder vår utbildning till speciallärare med inriktning mot intellektuell funktionsnedsättning har vi pratat om och diskuterat framtiden för eleverna. Möjligheterna efter anpassad utbildning är få och många tillbringar hela sitt vuxna liv i daglig verksamhet. Syftet med detta examensarbete är att undersöka och bidra med kunskap om lärares upplevelser av att undervisa om pengars värde i anpassad skola årskurs 7-9. Studien utgår från sociokulturellt lärandeperspektiv, vilket innebär att lärande ses som en social och kulturell process som sker genom interaktioner med andra, samt delaktighetsperspektiv där betoning ligger på att delaktighet sker i ett sammanhang, i aktivitet tillsammans med andra. Studien är kvalitativ, vi har genomfört semistrukturerade intervjuer med lärare från sju olika skolor. Vi har sedan analyserat det empiriska materialet enligt Braun och Clarks (2006) tematiska analys i kombination med interpretativt fenomenologiskt analysförfarande (IPA). Analysen av det empiriska materialet mynnar ut i tre överordnade teman som belyser lärares syn på möjligheter och svårigheter i undervisningen samt undervisningens påverkan på elevers framtid. I vår studie har vi kommit fram till att lärare upplever att det är viktigt och samtidigt frustrerande att undervisa elever om pengars värde. Medvetenheten om vikten av att kunna hantera sin ekonomi för eleverna i framtiden brottas med vissheten om att en stor del av elevernas framtid innebär att leva med väldigt små ekonomiska marginaler.
Calculation Methods and Supplier Selection under Increased Supply of Hardware through a Central Warehouse : A Study at Derome Bygg & Industri AB
No full textFöretag är i hög grad beroende av sina försörjningsflöden. Strukturen på dessa flöden har en betydande inverkan på företagens konkurrenskraft och lönsamhet, och kan skapa förutsättningar för både kostnadsreduktioner och förbättrad service. Ett företag som vill undersöka om förändringar i försörjningsflödet kan bidra med kostnadssänkningar är Derome Bygg & Industri AB, vars verksamhet består av bygg- och industrihandel för företagskunder. Företagets 47 bygghandelsbutiker försörjs idag genom två olika flöden: direkt leverans från leverantör, och leverans via företagets eget centrallager. Idag skickas de flesta artiklarna med direkt leverans, men en ökning av antalet artiklar som försörjs via centrallager kan ge fördelar som kortare ledtider, flexibla förpackningsstorlekar och stordriftsfördelar. Å andra sidan kan det resultera i en ökad hantering och fler interna transporter. Derome Bygg & Industri AB vill utreda hur kostnaderna förändras med ett större flöde av artiklar via centrallagret, och är även intresserad av potentiella förändringar i servicen i flödet. Företaget befinner sig dessutom i en period där många leverantörsavtal ska omförhandlas och vill därför utreda vilka leverantörer som medför kostnad och servicefördelar när deras artiklar försörjs via centrallagret. Studiens syfte formulerades enligt följande: Ta fram ett arbetssätt som Derome kan använda för att välja leverantörer för försörjning via centrallager. För att besvara studiens syfte genomfördes inledningsvis en kostnadsmodellering vid ett ökat flöde genom centrallagret. Detta gjordes med hjälp av de första stegen i en totalkostnadsanalys, vilka resulterade i en kartläggning av alla aktiviteter i företagets försörjningsflöde, urval av relevanta kostnadskategorier, förslag på beräkningsmetoder för dessa, nödvändig indata, samt urval av vilka serviceelement som bör tas hänsyn till tillsammans med totalkostnadsanalysen. Utöver att vägledas av metoden för totalkostnadsanalys genomfördes även intervjuer med medarbetare på Derome Bygg & Industri AB, med expertis inom olika delar av försörjningskedjan. För totalkostnadsmodellen valdes att inkludera administration-, transport- lagerföring- och materialkostnader. Vidare bedömdes ledtid, leveranssäkerhet och lagertillgänglighet som relevanta serviceelement att ta hänsyn till tillsammans med totalkostnadsanalysen. Vidare undersöktes vilka leverantörer som kan prioriteras för vidare beräkning av företaget. Detta gjordes genom att identifiera egenskaper hos leverantörerna respektive artiklarna, med hjälp av analys av intervjuer och totalkostnadsanalysen. Egenskaperna sammanställdes sedan i en lista där de prioriterades efter egenskapernas påverkan på totalkostnadsanalysen, samt Deromes möjlighet att bedöma respektive egenskap. På högsta prioritet placerades egenskaperna: långa ledtider, höga fraktavgifter, höga fraktgränser i förhållande till inköpt volym, samt hög andel lågrörliga artiklar i butik. En rekommendation skapades för hur Derome Bygg & Industri AB kan tillämpa arbetssättet i praktiken. Denna rekommendation beskrevs i tre steg: välj en leverantör, utför totalkostnadsanalysen samt undersök serviceelement. Vidare beskrivs en rekommendation för hur Derome & Industri AB kan utvärdera och vidareutveckla arbetssättet. Companies are highly dependent on their supply flows. The structure of these flows has a significant impact on their competitiveness and profitability, and can enable both cost reductions and improved service. One company that aims to investigate whether changes in the supply flow can contribute to cost savings is Derome Bygg & Industri AB, whose operations consist of construction and industrial trade for business customers. The company’s 47 hardware stores are currently supplied through two different flows: direct delivery from suppliers and delivery via the company’s central warehouse. Most articles are currently delivered directly from suppliers, but increasing the number of articles supplied via the central warehouse may offer advantages such as shorter lead times, flexible packaging sizes, and economies of scale. On the other hand, it may result in increased handling and more internal transportation. Derome Bygg & Industri AB seeks to assess how costs are affected by a larger flow of articles through the central warehouse and is also interested in potential changes in service within the flow. Furthermore, the company is entering a period during which many supplier contracts are to be renegotiated and therefore wants to identify which suppliers offer cost and service advantages when their articles are supplied through the central warehouse. The purpose of the study was formulated as follows: Develop a systematic approach that Derome can use to select suppliers for supply through the central warehouse. To answer the purpose of the study, a cost modelling was initially carried out for an increased flow through the central warehouse. This was done using the initial steps of a total cost analysis, which resulted in a mapping of all activities in the company's supply flow, a selection of relevant cost categories, proposed calculation methods for these, required input data, as well as the selection of service elements to be considered alongside the total cost analysis. In addition to being guided by the method for total cost analysis, interviews were conducted with employees at Derome Bygg & Industri AB who hold expertise in various parts of the supply chain. The total cost model included administrative, transportation, inventory carrying, and material costs. Furthermore, lead time, delivery reliability, and inventory availability were assessed as relevant service elements to consider alongside the total cost analysis. Additionally, the study examined which suppliers could be prioritized for further evaluation by the company. This was done by identifying characteristics of the suppliers and the articles, based on an analysis of interviews and the total cost analysis. The characteristics were compiled into a list and prioritized based on their impact on the total cost analysis and Derome’s ability to assess each characteristic. The highest priority was given to the following characteristics: long lead times, high freight charges, high freight thresholds relative to purchased volume, and a high proportion of slow-moving articles in stores. A recommendation was developed for how Derome Bygg & Industri AB can apply the proposed approach in practice. This recommendation was described in three steps: select a supplier, conduct the total cost analysis, and examine the service elements. Furthermore, a recommendation is provided for how Derome Bygg & Industri AB can evaluate and further develop the approach
Lower Surgical Volume Reduces the Odds of Performing Meniscus Repair for Tears During Primary Anterior Cruciate Ligament Reconstruction
No full textPurpose: To investigate the influence of surgical volume, and various patient-, injury-, and surgery-related factors, on meniscal treatment strategies in primary anterior cruciate ligament reconstruction (ACLR). Methods: This retrospective cohort study analyzed patients with concomitant meniscal injuries undergoing primary ACLR, from 2008 to 2022, using data from the Swedish National Knee Ligament Registry. Surgeons and clinics were stratified by total caseload (cutoff: 50 ACLRs/surgeon, 500 ACLRs/clinic) and annual volume (cutoff: 29 ACLRs/year/surgeon, 56 ACLRs/year/clinic). To assess factors influencing medial meniscus or lateral meniscus repair, adjusted multivariable logistic regression was conducted, with results presented as odds ratios (OR) and 95% confidence intervals (CI). Results: In total, 20,699 patients undergoing primary ACLR with concomitant meniscal injuries were included. Lower percentages of meniscus repair were seen among surgeons with low caseload and annual volume (LCLV) (13.3%-20.8%) compared with high caseload and annual volume (HCHV) surgeons (19.0%-29.8%), and at LCLV clinics (11.1%-18.3%) compared to HCHV clinics (21.5%-33.8%), all P < .001. Significantly decreased odds of medial meniscus repair were seen for patients operated on by LCLV surgeons (OR 0.82, 95% CI 0.70-0.96; P = .015) or at LCLV clinics (OR 0.56, 95% CI 0.50-0.64; P < .001. Similar results were seen for lateral meniscus repair with LCLV surgeons (OR 0.83, 95% CI 0.69-1.01; P = .067) and LCLV clinics (OR 0.62, 95% CI 0.53-0.72; P < .001). Additionally, younger age, female sex, shorter time from injury to surgery, and ACLRs performed more recently were associated with increased odds of repair. Conclusions: Lower surgical volume significantly decreased the rates and odds of performing meniscal repair during primary ACLR. In contrast, ACLRs performed during more recent years, younger age, female sex, shorter time from injury to surgery, absence of chondral injuries, and injuries sustained during nonpivoting activities, positively influenced meniscal preservation. Level of evidence: Level III, retrospective cohort study
AI-Driven Value Creation and Organizational Change : A Qualitative Study of the Swedish Retail Industry
No full textRelevance: The retail industry has undergone substantial transformations driven by technological advancements, with Artificial Intelligence (AI) emerging as vital for staying competitive. However, despite its growing influence, there is limited understanding of its effects on retail operations and value creation. Purpose: This study aims to explore AI's impact and disruptive potential within the Swedish retail industry. It examines the current state of AI within retail, as well as two main areas: 1) AI value creation, and 2) Organizational change driven by AI. Ultimately, this study aims to address the gap between theoretical and practical research, extend theory, and offer some practical insights. Methodology: A qualitative, exploratory design is adopted, using an abductive approach. Data is gathered through 21 semi-structured conducted online via Microsoft Teams. These interviews focused on the retailers' understanding of AI, its future potential, its transformative impact on value creation and organizational activities. Result: Findings show the industry's current approaches and perceptions towards AI, as well as futuristic speculations about AI and retail. It shows how, what, and for whom AI creates value, and confirms previous studies displaying a complex, dual nature of AI. While it offers great potential, it also entails inherent challenges. Evidence indicates that technology-driven organizational change initiated by AI forces compulsory change in other organizational dimensions. More specifically, in the tasks conducted, the people involved and the structures applied. Exploring Strategies for Value Creation in the Age of AI Transformation