Publikationer från Högskolan i Jönköping
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A Comparative Evaluation of Traditional Portfolio Optimization (Markowitz) and Deep Reinforcement Learning for Financial Portfolio Management : Predictability in Emerging vs. Developed Markets Amid Geopolitical Tensions
No full textPortfolio optimization solutions for developed and emerging financial markets during a period of increased geopolitical tension and economic fragmentation (2023-2024) are examined in this study. Specifically, the study compares the effectiveness of a model-free Deep Reinforcement Learning (DRL) strategy using the Twin-Delayed Deep Deterministic Policy Gradient (TD3) algorithm with that of Modern Portfolio Theory (MPT) - through Maximum Sharpe Ratio (MS) and Minimum Variance (MV) strategies. The top 30 large-cap equities in four sample markets - the United States and Sweden (developed) – China, and Vietnam (emerging) - were used to construct the portfolios. Models were trained on data prior to 2023 and evaluated on out-of-sample performance for 2023–2024 using historical data from 2013–2024. Evaluation indicators included the Sharpe and Sortino ratios, volatility, maximum drawdown, and annualized return. While DRL provides theoretical adaptability and creativity, further refinement is necessary to enhance its practical implementation in financial markets. This study adds to existing literature by critically evaluating the readiness of AI models for active portfolio management and emphasizing the importance of context-driven strategy selection
To motivate students to activities in school-age educare
No full textSyftet med denna studie är att beskriva hur lärare i fritidshem arbetar för att motivera eleverna att delta i aktiviteter som lärare erbjuder på fritidshemmet. Nio lärare i fritidshem deltog via semistrukturerade intervjuer. Tematisk analys användes för att analysera det transkriberade datamaterialet. Resultatet visade fem teman som centrala för motivation till aktiviteter: friheten att välja, goda relationer, att lyckas och våga vara med, lärarens roll, samt hinder till att motivera i fritidshemmet. Self determination theory användes för att diskutera resultatet. Studien visar många möjligheter att motivera elever till aktiviteter och att läraren har en central roll i att åstadkomma detta. Samtidigt existerar utmaningar och hinder i dels vilka resurser som finns till förfogande i relation till elevgruppens behov och intressen, dels att empirin, teorin och tidigare forskning poängterar att motivation likt ett korthus faller vid avsaknad av vissa pusselbitar som är i behov av att tillfredsställas.
Sustainable Last-Mile Delivery in Omni-Channel Retail in Sweden
No full textPurpose: To examine how omni-channel retailers in Sweden promote sustainable last-miledelivery options. The study is focusing on crucial challenges of balancing fast, costeffective, and environmental responsibility. Two research questions were developed toinvestigate the previously stated purpose in-depth: 1. What last-mile delivery do omnichannel retailers offer end-customers? 2. What common strategies are employed by omnichannel retailers in Sweden to promote sustainable last-mile deliveries? Method: A quantitative, descriptive and cross-sectional design was employed, alongside acombination of systematic sampling and analysis for the primary data. Secondary data isused as qualitative approach. The data was collected from 100 omni-channel retailers inSweden: 50 large-sized, 50 medium-sized. With primary focus on delivery speed, price, 3PLprovides and diversity of sustainable delivery certifications which underwent analyses andcomparison. Findings: The study found that omni-channel retailers offer various delivery methodsincorporating different labels promoting sustainable practices. However, sustainabledelivery options such as fossil-free, Swan or climate compensated are vaguely and unclearlycommunicated at the retailer’s check-out stage. Larger retailers offer more sustainableofferings compared to medium-sized retailers. Implications: The study highlights the need for improved communication and greatertransparency from retailers when promoting sustainable last-mile deliveries. The limitedinformation posed an implementation regarding the available data for collection. Publiclyavailable data on sustainable labels and certificates were limited when gathering necessarydata during the research. Limitations: The study is limited by large and medium retailer sample size exclusively in Sweden, reducing generalizability. Incorporating small-sized retailers, and a deeperunderstanding of 3PLs would elevate the study. Furthermore, including small-size retailerswould provide a more complete understanding of last-mile delivery practices
Steering Wheel Resistance Optimization in Steer-by-Wire: a Comparative Study
No full textThis thesis investigated two different approaches for determining steering wheel resistance in steer-by-wire systems: one based on a traditional algorithm and one using machine learning. The aim was to assess which method provided a more natural and user-preferred steering feel. Both methods used the same input parameters - steering angle, steering angle speed, and vehicle speed - and were developed, tested, and evaluated through multiple iterations. The traditional algorithm applied manually tuned coefficients, while the machine learning model was built using gradient boosting techniques. A simulator environment was used to apply and test the output from both methods. User feedback was collected after blind testing with ten drivers across three test rounds. Both qualitative and quantitative data were analyzed to evaluate realism, responsiveness, and overall satisfaction. The results showed that while both methods could be adjusted to produce acceptable outcomes, the machine learning model was generally preferred by users due to its smoother and more natural steering feel. This study contributed to a better understanding of how data-driven methods could be used to improve driver experience in emerging vehicle technologies
CASE STUDY OF MATERIAL REUSE PROJECT LUNA IN SÖDERTÄLJE
No full textIntroduktion - Utsläpp från byggbranschen är en stor del av Sveriges totalakoldioxidutsläpp. Sverige är i förändring att minska dessa utsläpp. Byggbranschen harmöjlighet att främja cirkulär ekonomi genom att återbruka större del av dagensbefintliga material från byggnader, både enskilda byggnadsdelar samt stommar. Måletmed uppsatsen är att studera förstudieprocessen inför ett ombyggnadsprojekt och vadsom krävs för att kunna återbruka en stomme. I detta fall kommer projekt Luna iSödertälje studeras, där stora delar av befintliga stommen avses att återbrukas vid enomfattande ombyggnadsprocess. Metod - Studien är till största del kvalitativ där intervjuer med inblandade aktörer inomprojektet har genomförts. Studien kommer även luta sig på konstruktionsdokument,byggnadskalkyler samt geoteknisk undersökning för att analysera det specifikaprojektet. Resultat - Projekt Luna är ett komplext ombyggnadsprojekt där Telge Fastigheter (TF)och Tyréns samarbetar för att undersöka möjligheterna att bevara och återanvändastommen i ett tidigare rivningsplanerat byggnadskomplex. Trots fuktskador och initialaplaner på total rivning visade det sig att stommen var i gott skick, vilket ledde till atthållbarhetsfrågor fick större utrymme i projektets inriktning. Tyréns analyseradekonstruktionens kapacitet med stöd av detaljerade relationshandlingar. Olika scenarierför om- och påbyggnad utvärderades utifrån både tekniska och ekonomiska aspekter,redovisade i en kalkyl och ett konstruktions-PM. Den befintliga, platsgjutnabetongstommen ansågs gynnsam för återbruk tack vare sin flexibilitet, men projektetstöter också på utmaningar som anpassning efter nya byggnadskrav och begränsadmarkbärighet. TF planerar även en återbrukshubb för att samla och återanvändabyggnadsdelar som tegel, fönster och möbler, även om konceptet ännu inte är fulltutvecklat. Slutligen betonas behovet av att väga hållbarhetsvinster mot tekniska ochekonomiska faktorer, inklusive beräkningar av koldioxidbesparing. Analys - Trots att vissa kostnader inte togs med i kalkylen, visar projektet att återbrukofta är billigare än nybyggnation. Flera faktorer är avgörande för att återbruk ska varamöjligt, däribland stommens skick, tekniska krav, logistik, miljöaspekter och tillgångtill korrekta ritningar. Projektet betonar att god planering och förstudie är avgörandeoch att återbruk bör övervägas även i framtida projekt. Även om varje projekt är unikt,kan modet att testa nya lösningar och tänka cirkulärt överföras. Luna är ett exempel påatt återbruk inte bara är möjligt utan också hållbart och framtidsinriktat. Diskussion - Studien lyckades besvara de centrala frågeställningarna genom intervjueroch analys av dokument från projekt Luna, även om vissa svar endast kunde antydas pågrund av projektets tidiga skede. Återbruk av stommen visade sig tekniskt möjligt ochekonomiskt fördelaktigt, enligt en intern kalkyl, men miljöaspekter kunde inteanalyseras fullt ut på grund av databrister. Intervjuerna gav mycket data men saknadeönskad struktur, vilket försvårade analysen. En mer kritisk granskning av kalkylen hadevarit möjlig med mer erfarenhet och tid. Trots vissa metodologiska brister anses studienge ett relevant och användbart resultat.Nyckelord - Cirkulär ekonomi, fallstudie, möjIntroduction - The construction industry is a significant contributor to Sweden's totalcarbon dioxide emissions. Sweden is undergoing changes to reduce these emissions.The construction sector can promote a circular economy by increasing the reuse ofexisting building components, both single components and structural elements. The aimof this thesis is to examine the preliminary study process for renovation projects andthe requirements for reusing a building structure. In this case, Project Luna in Södertäljewill be studied, where large parts of the existing structure will be reused in an extensiverenovation process. Method - The study is primarily qualitative, based on interviews with key stakeholdersinvolved in the project. It will also incorporate construction documents, building costestimates, and geotechnical investigations to analyze the specific project. Results - Project Luna is a reconstruction initiative where Telge Fastigheter and Tyrénsshifted from planned demolition to exploring reuse of the existing structural frame afterdiscovering it was in good condition. The project emphasizes sustainability, supportedby detailed assessments of structural capacity and cost. The cast-in-place concreteframe proved flexible and suitable for reuse, though challenges remain, includingcompliance with new regulations and limited soil capacity. Tyréns evaluated variousreconstruction scenarios, including adding floors, from both technical and financialperspectives. TF also plans a reuse hub for salvaging materials like bricks and windows,though the concept is still developing. Overall, the project highlights the importance ofbalancing environmental benefits with practical and economic considerations. Analysis - Project Luna shows that reusing an existing structural frame can be costeffective, particularly when the structure is in good condition and relocation isn’tneeded. Although not all costs were included, reuse proved cheaper than newconstruction. Success depends on factors like structural condition, technical andlogistical feasibility, environmental impact, and access to accurate documentation. Theproject underscores the need for careful planning and early analysis. While each projectis different, Luna illustrates the broader value of innovation and circular thinking. Itstands as a strong example of sustainable and forward-looking building practices. Discussion - The study successfully addressed the central research questions throughinterviews and analysis of documents from Project Luna, although some answers couldonly be suggested due to the project's early stage. The reuse of the structural frame wasfound to be technically feasible and economically beneficial, according to an internalcost estimate, but environmental aspects could not be fully analyzed due to datalimitations. The interviews provided a large amount of data but lacked the desiredstructure, which made analysis more challenging. A more critical review of the costestimate would have been possible with more experience and time. Despite certainmethodological shortcomings, the study is considered to provide relevant and usefulresults.
Digital Nudges for Reducing Social Media Screen Time
No full textThis study explores whether user experience (UX) nudges can help young adults reduce their screen time on social media, specifically on TikTok, and whether they find these nudges useful. Many social platforms are designed to be addictive, and traditional digital self-control tools are often ignored. In this study, 11 participants aged 18-25 tested two UX nudges over one week: a short breathing exercise and a self-imposed timer, both shown before using the app. Data was collected through screen time measurements and pre- and post-intervention interviews. The average screen time decreased by 193 minutes (35.8%), but the change was not statistically significant. However, most participants said the nudges made them more aware of their usage and helped them reflect before scrolling. The qualitative data was analyzed using inductive content analysis, showing themes like increased awareness, behavioral change, and irritation due to repetition. While some participants found the nudges helpful, others wanted more customization or found them annoying. The study suggests that nudges can support more mindful use of social media, even if they do not always lead to major behavior changes. It highlights the importance of designing interventions that balance helpfulness with user comfort. Further research with a larger group and longer duration is needed to better understand the long-term impact
Wood Recycling: Challenges and Opportunities for Sustainable Construction
No full textByggsektorn står inför stora miljöutmaningar, där ett ökat återbruk av byggmaterial lyfts fram som en central lösning för att minska resursanvändning och klimatpåverkan. Detta examensarbete syftar till att undersöka vilka möjligheter och hinder som finns för att återbruka trä i byggprojekt, samt att identifiera de mest kostnadseffektiva metoderna och materialen för detta ändamål. Studien fokuserar särskilt på hur återbruk av trä kan främjas genom samverkan, logistik och digitala lösningar, samt hur olika aktörer inom byggprocessen påverkar förutsättningarna för att skala upp återbruk.Arbetet har genomförts med en kvalitativ metod i form av en litteraturstudie kompletterad med en kvantitativ enkät riktad till aktörer verksamma i olika typer av byggprojekt i Sverige. Litteraturstudien behandlade bland annat cirkulär ekonomi, träets materialegenskaper vid återbruk, samt tidigare forskningsresultat om ekonomiska och praktiska barriärer. Enkäten samlade in synpunkter från ett brett spektrum av praktiker för att identifiera aktuella erfarenheter och behov i genomförda och planerade projekt.Resultaten visar att återbruk av trä upplevs som miljömässigt fördelaktigt och positivt laddat hos många aktörer, men att brist på information, standarder och kvalitetssäkring ofta hindrar praktiskt tillämpning. Många ser potential i digitala materialbanker och förbättrad spårbarhet, men efterlyser mer stöd i form av policy, utbildning och ekonomiska incitament. Samtidigt pekar både litteratur och enkätsvar på att demontering, lagring och logistik är kritiska faktorer som påverkar återbrukets lönsamhet i byggprojekt.Analysen visar att samverkan mellan aktörer, samt systematiskt stöd genom digitalisering och standardisering är avgörande för att överkomma dagens hinder. De mest framgångsrika lösningarna kombinerar teknisk kvalitetssäkring med affärsmodeller som fördelar kostnader och risker i kedjan. Återbrukets klimatnytta är stor, men för att realisera potentialen krävs ett helhetsgrepp över hela livscykeln för trä i byggprojekt.I diskussionen betonas att omställningen till ett cirkulärt byggande med återbruk av trä inte är en teknisk utan snarare en systemisk och organisatorisk utmaning. Arbetet rekommenderar vidare forskning om livscykelanalyser av återbrukat trä, affärsmodeller och digitala verktyg för spårbarhet, samt utvärdering av policyinstrument för att främja cirkulära materialflöden i byggprojekt.The Construction sector faces major environmental challenges, where increased reuse of building materials is highlighted as a key strategy to reduce resource consumption and climate impact. This thesis aims to explore the opportunities and obstacles related to the reuse of wood in construction projects, as well as to identify the most cost-effective methods and materials for such reuse. The study focuses in particular on how wood reuse can be promoted through collaboration, logistics and digital solutions and how different actors within the construction process influence the conditions for scaling up reuse.The work was conducted using a qualitative method in the form of a literature review, supplemented by a qualitative survey directed at stakeholders involved in various types of construction projects in Sweden. The literature review covered circular economy principles, the material properties of reused wood and previous research on economic and practical barriers. The survey gathered insights from a broad range of practitioners to identify current experiences and needs in both completed and planned projects.The results show that wood reuse is widely perceived as environmentally beneficial and positively received among actors, but that a lack of information, standards and quality assurance often hinders practical application. Many respondents see strong potential in digital material banks and improved traceability, yet call for more support through policies, education and financial incentives. Both the literature and survey responses point to deconstruction, storage and logistics as critical factors influencing the cost-efficiency of reuse in construction projects.The analysis highlights that collaboration between actors, along with systematic support through digitalization and standardization is essential for overcoming current barriers. The most effective solutions combine technical quality assurance with business models that distribute costs and risks across project phases. While the climate benefits of reuse are significant, realizing its full potential requires a life cycle perspective on wood use in construction projects.The discussion emphasizes that the transition to circular construction involving wood reuse is not primarily a technical challenge, but rather a systematic and organizational one. The study recommends further research into life cycle assessments of reused wood, business models and digital tools for traceability, as well as policy instruments that can promote circular material flows in construction projects
CNC Milling as an alternative to traditional craftmanship in the restoration of culturally historic buildings
No full textCulturally historic buildings carry stories, traditions, and cultural expressions that are crucial to preserve for future generations. The restoration of these buildings requires solutions that are carefully adapted to maintain the original architecture and historical value, often through the use of traditional craftmanship methods. However, knowledge of traditional craftmanship has declined, and it can be time-consuming, costly, and complex. At the same time, digitization is becoming increasingly prominent. The aim of the study is to investigate how CNC milling, a digital method based on computerization and automation, can be used to recreate details from culturally historic buildings during restoration. The purpose is to examine how the method can replace or complement traditional craftmanship without compromising the preservation of the architecture, with regard to time consumption, cost, visual expression, and authenticity. The study was conducted as a qualitative case study based on literature review and semi structured interviews. The interviews were held with professional building conservators, craftsmen, and CNC specialists to gather both theoretical and practical perspectives. The results show that the attitude toward CNC milling varies depending on professional role. Regarding time consumption, the milling process itself is fast, but the preparatory work is time-consuming. From a cost perspective, CNC milling is most efficient for larger volumes, and traditional craftmanship is often cheaper for single-piece production. In terms of visual expression, CNC-milled details tend to be perceived as too perfect, lacking the liveliness, variation, and character found in handcrafted objects, despite the possibility of post-processing. The discussion highlights that the impact on authenticity is the greatest concern, as mechanical methods risk distorting the buildings historical “readability”. The study concludes that CNC milling is approached with great caution from a preservation perspective, but can be seen as a logical option from a production standpoint in cases of repetitive manufacturing or limited resources
Analysis of password creation behavior using leaked credentials
No full textIn today’s rapidly evolving cyberspace, passwords remain the most commonly used form of authentication. Despitethe growing adoption of Multi-factor Authentication (MFA), they continue to play a vital role. Understanding howpasswords are created and the factors that influence their creation are crucial for improving password policies anduser training. This study analyzes a large-scale dataset of breached credentials to explore patterns in passwordcreation, focusing on cultural, linguistic and institutional factors. Specifically, the following research questionsare addressed: (1) What password patterns are found in public data breaches across different countries? (2) Howdo cultural factors influence password selection regarding estimated password strength and length? (3) Howdo linguistic factors influence password selection and security practices? and (4) Do affiliations to the securityapparatus, like police, military or intelligence services, lead to stronger password practices?To answer these questions, a subset of 380 million credentials from the Compilation of Many Breaches (COMB)dataset was imported into a database. Password strength scores were assessed using the zxcvbn algorithm, withlanguage-specific dictionaries incorporated to evaluate linguistic effects. The analysis reveals that while passwordcreation behavior differs across domains and regions, globally recurring patterns remain dominant. The averagelength of password varies between 9.26 and 8.24, with users of .de exhibiting the longest passwords on average.Although users affiliated with the security apparatus employed more unique passwords, their average strengthscores were only marginally different from the general dataset. These findings underscore subtle cultural andlinguistic influences on password creation behavior and support the need for tailored password policies and usertraining