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From Plan to Reality - Pathways to Affordable and Quality Housing in Addis Ababa
No full textDenna studie undersöker hur Addis Ababa, Etiopiens snabbt växande huvudstad, arbetar med att tillgodose behovet av bostäder som är både prisvärda och av god kvalitet för låginkomsttagare. Trots omfattande planer och bostadsprogram kvarstår en betydande bostadsbrist, särskilt för socioekonomiskt utsatta grupper. Studien fokuserar på två centrala bostads initiativ: det statliga hyressystemet Kebele housing och bostadsprogrammet Integrated Housing Development (IHDP). Genom kvalitativa metoder, inklusive dokumentanalys och intervjuer med nyckelaktörer inom offentlig, privat och akademisk sektor i Addis Ababa, analyseras både tekniska och sociala dimensioner av prisvärda bostäder samt frågan om implementering. Resultatet visar att även om de båda programmen delvis svarat mot målet om prisvärda bostäder, har de inte lyckats kombinera detta med långsiktig kvalitet och social hållbarhet. Studien identifierar bristande samordning mellan aktörer och brist på tydlig ansvarsfördelning som centrala hinder för genomförande. Som möjlig väg framåt föreslås ett förstärkt samarbete genom offentlig-privata partnerskap (public-private partnerships), där staten spelar en nyckelroll i att samordna, reglera och möjliggöra genomförandet. Studien belyser även vikten av att integrera invånarnas perspektiv i bostadsfrågan, social hållbarhet och tydlig ansvarsfördelning i utvecklingen av framtidens bostadsutveckling i Addis Ababa.This study examines how Addis Ababa, the fast-growing capital of Ethiopia, is addressing the need for affordable and quality housing for low-income households. Despite comprehensive plans and housing programmes, a significant housing shortage remains, particularly for socio-economically vulnerable groups. The study focuses on two key housing initiatives: the government rental scheme Kebele housing and the Integrated Housing Development Programme (IHDP). Through qualitative methods, including document review and interviews with key actors in the public, private and academic sectors in Addis Ababa, the study analyses both technical and social dimensions of housing affordability and the issue of implementation. The results show that although both programmes have partly met the objective of affordable housing, they have not succeeded in combining this with long-term quality and social sustainability. The study identifies a lack of coordination between actors and a lack of clear division of responsibilities as key barriers to implementation. As a possible way forward, the study suggests strengthening cooperation through public-private partnerships, with the government playing a key role in coordinating, regulating and enabling implementation. The study highlights the importance of integrating residents’ perspectives in housing, social sustainability and clear accountability in the development of future housing development in Addis Abab
Omvandlingen av Île-de-France för att möta ett varmare klimat
No full textUrban overheating exacerbates the impact of heatwaves, making cities significantly hotter than surrounding rural areas. The Ile-de-France region, Paris’ region, is particularly vulnerable to this phenomenon. As climate change drives more frequent and intense heatwaves, cities must urgently develop strategies to both mitigate and adapt to urban overheating. Using Ile-de-France as a case study, this research draws on interviews with municipal and intermunicipal staff and applies the framework of transformational adaptation to examine municipal and intermunicipal planning efforts, and related adaptation constraints. The study finds that while technical solutions are frequently considered, social, cultural and institutional dimensions are often overlooked, leading to incomplete and insufficient adaptation.Urban värmeö-effekten i städerna förstärker värmeböljor och leder till betydligt högre temperaturer i städer än i omgivande landsbygdsområden. Ile-de-France är särskilt sårbart för detta fenomen. Eftersom klimatförändringarna orsakar allt vanligare och intensivare värmeböljor måste städerna redan nu utveckla strategier för att begränsa och anpassa sig till konsekvenserna av värmeö-effekter i urbana miljöer. Den här studien tar Ile-de-France som fallstudie och undersöker lokala strategier för att möta urban värmeö-effekten genom intervjuer med representanter från kommunala och mellankommunala myndigheter. Studien använder begreppet transformativ anpassning för att analysera kommunala och mellankommunala planeringsinsatser i relation till klimatförändringarna och identifiera de tillhörande hinder. Analysen visar att tekniska lösningar ofta prioriteras, medan sociala, kulturella och institutionella aspekter ofta förbises, vilket leder till ofullständiga och otillräckliga klimatanpassningsåtgärder
Open Mikes for Music in Stockholm’s Municipality
No full textDetta examensarbete undersöker hur öppna musikscener kan fungera som tredje rum och bidra till social hållbarhet. Studien har samlat in data via platsbesök från tre öppna musikscener i Stockholms stad, samt 18 intervjuer med deltagare, arrangörer och en representant från stadens kulturförvaltning. Arrangörernas syfte och lokalens fysiska utformning påverkade hur scenerna uppfyllde kriterierna och funktionerna för tredje rum. Ju mer arrangörerna prioriterade gemenskapen, desto större utrymme gavs till konversation mellan deltagarna. Scenen med mest fokus på gemenskap upplevdes också som ett andra hem. Två av scenerna brast i tillgänglighet för rörelsehindrade, samt hade en mansdominans. Samtliga scener genomsyrades av lekfullhet, samt bidrog med funktionerna underhållning, vänskap, umgänge över generationsgränserna och att likasinnade träffades. Eftersom upptagningsområdet var från hela staden kunde scenerna ej bedömas gynna bostadsområdet specifikt, men däremot staden som helhet. En betydande merpart önskade att staden skulle stödja öppna musikscener, främst genom finansiering av utrustning och lokaler samt för att kunna anordna större event. I dagsläget ger staden inget kulturstöd till öppna musikscener. Denna studie belyser öppna musiksceners potential till att bidra till social hållbarhet, vilket är ett sedan tidigare outforskat fenomen. Resultaten visar att det är något som Stockholms stad bör kolla närmare på för att uppnå sin vision om en hållbar stad, samt att ämnet är värt vidare forskning.This degree project studies how open mikes dedicated to music can function as third places and contribute to social sustainability. The study has collected data through site-visits to three open mikes in Stockholm’s municipality, as well as 18 interviews with participants, organisers and a representative from the municipality. The organisers’ purpose and the physical design of the local affected to what degree the open mikes reached the criteria and functions of a third place. The more the organisers prioritised community, the more room was given to conversation. The open mike that most focused on community was also described as a second home. Two of the open mikes were inaccessible for people with disabilities, while being male-dominated. Playfulness was prevalent at all three open mikes. Moreover, they contributed with entertainment, friendship and a place for people with similar interests to meet each other. Since the attendees came from the whole city of Stockholm, the open mikes might not benefit the neighbourhood specifically, but rather the city as a whole. A vast majority of the participants and the organisers wished that the municipality would offer financial support to open mikes, primarily to pay for equipment, locals, and to organise larger events. At the moment, the municipality offers no cultural support to them. This study shines light on open mikes dedicated to music, and their potential to contribute to social sustainability, which is a phenomenon previously not researched upon. The phenomenon is worth further studies, as well as more attention from the municipality
Predicting opportunities for improvement in trauma care using machine learning : a retrospective registry-based study at a major trauma centre
No full textOBJECTIVE: To develop models to predict opportunities for improvement in trauma care and compare the performance of these models to the currently used audit filters. DESIGN: Retrospective registry-based study. SETTING: Single-centre, Scandinavian level one equivalent trauma centre. PARTICIPANTS: 8220 adult trauma patients screened for opportunities for improvement between 2013 and 2022. PRIMARY AND SECONDARY OUTCOME MEASURES: Two machine learning models (logistic regression and XGBoost) and the currently used audit filters were compared. Internal validation by an expanding window approach with annual updates was used for model evaluation. Performance measured by discrimination, calibration, sensitivity and false positive rate of opportunities for improvement prediction. RESULTS: A total of 8220 patients, with a mean age of 45 years, were analysed; 69% were men with a mean injury severity score of 12. Opportunities for improvement were identified in 496 (6%) patients. Both the logistic regression and XGBoost models were well-calibrated, with intercalibration indices of 0.02 and 0.02, respectively. The models demonstrated higher areas under the receiver operating characteristic curve (AUCs) (logistic regression: 0.71; XGBoost: 0.74). The XGBoost model had a lower false positive rate at a similar sensitivity (false positive rate: 0.63). The audit filters had an AUC of 0.62 and a false positive rate of 0.67. CONCLUSIONS: The logistic regression and XGBoost models outperformed audit filters in predicting opportunities for improvement among adult trauma patients and can potentially be used to improve systems for selecting patients for trauma peer review.QC 20250704</p
Do the receptive fields in the primary visual cortex span a variability over the degree of elongation of the receptive fields?
No full textThis paper presents the results of combining (i) theoretical analysis regarding connections between the orientation selectivity and the elongation of receptive fields for the affine Gaussian derivative model with (ii) biological measurements of orientation selectivity in the primary visual cortex to investigate if (iii) the receptive fields can be regarded as spanning a variability in the degree of elongation. From an in-depth theoretical analysis of idealized models for the receptive fields of simple and complex cells in the primary visual cortex, we established that the orientation selectivity becomes more narrow with increasing elongation of the receptive fields. Combined with previously established biological results, concerning broad vs. sharp orientation tuning of visual neurons in the primary visual cortex, as well as previous experimental results concerning distributions of the resultant of the orientation selectivity curves for simple and complex cells, we show that these results are consistent with the receptive fields spanning a variability over the degree of elongation of the receptive fields. We also show that our principled theoretical model for visual receptive fields leads to qualitatively similar types of deviations from a uniform histogram of the resultant descriptor of the orientation selectivity curves for simple cells, as can be observed in the results from biological experiments. To firmly investigate the validity of the underlying working hypothesis, we finally formulate a set of testable predictions for biological experiments, to characterize the predicted systematic variability in the elongation over the orientation maps in higher mammals, and its relations to the pinwheel structure.Covariant and invariant deep network
Förbättrad hållbarhetsrapportering i energidistributionssektor : i linje med CSRD:s krav på klimatförändringar, biologisk mångfald och cirkulär ekonomi
No full textThis study examines how large energy companies (LEC) in Sweden can better support their real estate and industrial customers in aligning with the Corporate Sustainability Reporting Directive (CSRD), by improving the provision of sustainability data related to climate change, biodiversity, and circular economy. Through a qualitative case-study approach combining the methods data analysis, and semi-structured interviews, the study focuses on the information needs of real estate customers using district heating and industrial customers using electricity distribution. The study was conducted in collaboration with the energy company E.ON. Findings indicate a clear imbalance in how companies report on the three environmental areas outlined in the European Sustainability Reporting Standards (ESRS). Climate change related disclosures (E1) are comparatively well developed and often supported by measurable indicators and internal targets. In contrast, biodiversity (E4) and circular economy (E5) receive less attention and are typically reported in broad, qualitative terms. This disparity appears to be linked to limited knowledge about the actual environmental impacts in these areas, as well as a lack of internal expertise, clear responsibilities, and standardized metrics. Companies also tend to prioritize topics that are easier to quantify and perceived more commonly expected by external stakeholders. Underreporting of areas like biodiversity and resource flows leads to incomplete information across the value chain, limiting customers’ ability to make informed decisions and weakening sustainability credibility. Since energy systems influence other sectors’ climate transitions, poor visibility of upstream impacts can hinder planning and reduce opportunities for innovation and long-term environmental improvements. Ultimately, the study highlights a need for a more proactive and collaborative approach to sustainability data sharing. To meet both regulatory expectations and broader environmental goals, large energy providers should invest in more integrated data systems, foster clearer communication channels, and work jointly with customers to identify relevant indicators. These improvements will be essential to ensure that sustainability reporting reflects what truly matters, environmentally, strategically, and societally. Denna studie undersöker hur stora energibolag i Sverige bättre kan stödja sina fastighets- och industrikunder i att uppfylla kraven enligt Corporate Sustainability Reporting Directive (CSRD), genom att förbättra tillgången till hållbarhetsdata relaterad till klimatförändringar, biologisk mångfald och cirkulär ekonomi. Genom en kvalitativ fallstudie ansats som kombinerar data analys av hållbarhetsrapporter och semistrukturerade intervjuer, fokuserar studien på informationsbehoven hos fastighetsbolag som använder fjärrvärme och industribolag som använder eldistribution, och har genomförts i samarbete med energibolaget E.ON. Resultaten visar en tydlig obalans i hur företag rapporterar inom de tre miljöområdena som definieras i European Sustainability Reporting Standards (ESRS). Klimatrelaterad rapportering (ESRS E1) är relativt välutvecklad och stöds ofta av mätbara indikatorer och interna mål. Däremot får biologisk mångfald (E4) och cirkulär ekonomi (E5) mindre uppmärksamhet och behandlas oftast i breda, kvalitativa termer. Denna skillnad verkar bero på begränsad kunskap om de faktiska miljöeffekterna inom dessa områden, samt brist på intern expertis, tydliga ansvarsområden och standardiserade metoder. Företag tenderar dessutom att prioritera ämnen som är enklare att mäta och upplevs mer efterfrågade av externa intressenter. Rapporteringsbristerna har samhälleliga konsekvenser. Underredovisning av områden som biologisk mångfald och resursflöden leder till ofullständig information längs värdekedjan, vilket begränsar kundernas möjligheter att fatta välgrundade beslut och försvagar trovärdigheten i hållbarhetsarbetet. Eftersom energisystem spelar en central roll i andra sektorers klimatomställning, kan låg synlighet av uppströms påverkan försämra planering och minska chanser till innovation och långsiktig miljöförbättring. Studien visar på behovet av ett mer proaktivt och samverkande arbetssätt kring hållbarhetsdata. För att möta både regulatoriska krav och bredare miljömål bör stora energibolag investera i mer integrerade datasystem, förbättra kommunikationsvägar och samarbeta med kunder för att definiera relevanta indikatorer. Sådana förbättringar är avgörande för att säkerställa att hållbarhetsrapporteringen speglar det som verkligen är viktigt, miljömässigt, strategiskt och socialt.
Bilfria somrar : en kritisk diskursanalys av gatuexperiment i Uppsala och Malmö
No full textIn recent years, the phenomenon of summer streets and summer squares has been a popular car-free street space intervention in Sweden. They are a good example of how municipalities plan and test new ideas in the transition from automobility to a sustainable city. In this thesis they are referred to as street experiments. Previous research has focused a lot on these types of interventions as embedded cases with the intention of reframing the system. Discourse analysis as a method in transport studies is not that common, and I perceive discourses about street experiments as a research gap. The aim of this thesis is to critically examine discourses about street experiments in the Swedish context, specifically in Uppsala and Malmö, and identify the resonance and dissonance between the municipalities that implement them and the public that uses them. There are three dominant discourses: the attractive and livable city, the green and sustainable city, and the politics of public space. Within these three discourses, different aspects nuance them, which shows the breadth and complexity of these experiments. The intentions of the Swedish street experiments differ slightly from the international academic debate; thus, they do not fully fit the definition. The municipalities’ discourse differs from the public as they are seen as embedded cases for their long-term goals, while the public sees them as a current change in their everyday lives. This finding shows the gap between the political and perception and opens up the need for self-evaluation by the municipalities and increased public participation and initiative in the public space
Imputation av Saknad Finansiell Fundamentaldata : Fallstudie om Imputering av Finansiell Fundamentaldata för Systematisk Kapitalförvaltning
No full textMissing data is a pervasive challenge across many data-driven domains, often included as one of multiple steps in pre-processing pipelines. In finance, the issue becomes particularly pronounced: domains like systematic investing rely heavily on Financial Fundamental Data (FFD) to extract predictive signals, but FFD is frequently incomplete, often in systematic and structurally complex ways. This thesis addresses the problem of handling missing FFD through imputation. A core contribution of this thesis lies in designing an evaluation strategy for imputation methods, a non-trivial task given the absence of labeled ground truth. To simulate realistic conditions, the thesis constructs a labeled dataset from fully observed entries and reintroduces missingness based on observed patterns. Two types of missing patterns are evaluated through the masking, enabling comparison of different evaluation design choices. This enables a consistent and realistic evaluation framework while avoiding look-ahead bias via strict time-based train-test splits. Five imputation techniques have been implemented and evaluated: Mean Imputation (MI), Last Observation Carried Forward Imputation (LOCFI), K-Nearest Neighbors Imputation (KNNI), Multiple Imputation by Chained Equations (MICE), and Miceforest (MF). Their performance was assessed using Mean Relative Error (MRE) across a multi-year, multi-sector dataset of over 13,000 publicly listed companies. Several modeling choices were examined, including whether to train imputation models globally or within sectors, and how the amount of historical data influences performance. Results show that LOCFI achieved the best overall performance, with MICE, MI, and KNNI performing well for specific variables. Sector-specialized models outperformed global models in several cases, highlighting the value of domain-informed modeling. Imputation accuracy improved with more historical data, though gains leveled off after a certain point. The implemented imputation methods yielded lower MREs when block masking had been applied compared to regular masking. These findings emphasize that both method selection and evaluation design choices are critical for effective imputation of missing financial fundamental data.Data som saknas är ett problem närvarande i många domäner, och är något som måste hanteras under förbehandling av data. Inom finans är denna problematik speciellt framträdande: områden som systematisk kapitalförvaltning är direkt beroende av Finansiell Fundamentaldata (FFD) för att extrahera prediktiva signaler. Samtidigt är FFD ofta icke-komplett, med mönster av data som saknas av systematisk och strukturellt komplex karaktär. Detta examensarbete adresserar just detta, imputation av FFD. En central aspekt av detta examensarbete återfinns i utformningen av en evalueringsstrategi för imputationsmetoder. Detta är en icke-trivial uppgift då ett komplett set av FFD inte finns tillgängligt för evaluering. För att simulera realistiska förutsättningar konstrueras ett komplett set av FFD genom urval av variabler och sektorer. Efter detta maskas det fulla datasetet baserat på två typer av mönster som identifierats. Genom att applicera två olika strategier för maskning av data fördjupas analysen av hur imputationsmetoder kan evalueras samt om och vilken inverkan som maskning av data har på resultaten. Fem imputationsmetoder har implementerats och evaluerats: medelimputation (MI), imputation med senaste observationen bevarad (LOCFI), imputation med k-närmsta grannar (KNNI), multipel imputation med kedjade ekvationer (MICE) samt Miceforest (MF). Respektive metods prestation evaluerades med relativt medelfel (MRE) för ett dataset bestående av över 13,000 publikt listade företag från olika sektorer med observationer från flera år. Flertalet modelleringsbeslut har analyserats, bland annat om modellerna skulle vara globala eller sektorspecifika samt hur tillgången på historiska data påverkade imputationen. Resultaten visar att LOCFI generellt presterar bäst, med stark prestation för metoderna MICE, MI och KNNI för specifika variabler. Vidare presterar sektorspecifika modeller bättre vilket antyder fördelar med domänspecifik modellering. Noggrannheten av imputationer tilltog initialt med tillgång till större volymer av historiska data varefter prestationen nådde en platå. Samtliga modeller presterade även bättre då block av maskade data introducerades i jämförelse med maskning av enstaka datapunkter. Resultaten betonar att både utformningen av evalueringsprocessen och val av imputationsmetoder är kritiska aspekter att ta i beaktning vid imputation av FFD
Termomekanisk FEA modell av stålskärning med gaslåga
No full textGas cutting of martensitic steel leads to thermomechanical behavior in the body which creates residual stresses in the material as well as phase transformations, but measuring these parameters are costly and time consuming. A computational model was created in LS DYNA which could simulate the process and model several thermomechanical parameters and phase transforms on the surface and inside of the body. The model was tested both for cutting a room temperature block of steel and a preheated block. The model performed well on simulating stresses overall and performed less well on modeling temperatures. The model can simulate phase transforms between martensite and austenite for room temperature bodies. Further work include verifying the stress fields, implementing further phases and iterating on the thermal aspect of the model.Gasskärning av martensitiskt stål leder till termomekaniska beteenden i kroppen vilket skapar restspänningar i materialet samt fastransformer, men att mäta dessa parametrar kostar och är tidskrävande. En datormodell skapades i LS DYNA som kan simulera processen och modellera flera termomekaniska parametrar och fastransformer på ytan och i kroppen. Modellen testades både för skärning av ett stålblock vid rumstemperatur samt ett uppvärmt block. Modellen gav bra resultat när det gällde att simulera spänningar och presterade sämre på att modellera temperaturer. Modellen kan simulera fastransformern mellan martensit och austenit för kroppar i rumstemperatur. Framtida arbete inkluderar att verifiera spänningsfälten, implementera flera faser och att iterera på den termiska aspekten av modellen
Self-compression of femtosecond pulses in second-order nonlinear media and precise characterisation of ultrashort pulses
No full textFemtosecond laser pulses are essential tools in modern science and technology, yet generating pulses that are both extremely short and experimentally accessible remains a persistent challenge. Conventional post-compression methods rely on the Kerr effect, a third-order nonlinear effect, but these approaches often require complex setups and a large laboratory footprint. This thesis explores a fundamentally different route to pulse compression by utilising the coherently driven transversal optical phonon-polariton modes in Potassium Titanyl Phosphate (KTP). Rather than relying on Kerr-based spectral broadening and subsequent dispersive compression, the method exploits strong second-order nonlinearities in KTP to generate polaritons by optical rectification so that their electric fields may be used for efficient Stokes sideband generation by electro-optic interaction. The resulting interplay with normal dispersion in the nonlinear crystal results in an order of magnitude shorter self-compressed pulses generated in a simple setup. Such pulses demand advanced characterisation methods. Building on insights from applied mathematics and optimisation theory, a new retrieval algorithm for Frequency-Resolved Optical Gating (FROG) measurements is introduced, which we call the Line-Search FROG (LSF) algorithm, that decouples the measurement data from the reconstruction process. This greatly improves the performance of the pulse retrieval fidelity in the presence of large amounts of noise. The LSF algorithm is highly versatile and applicable to all FROG geometries, including the so-called double-blind FROG, with which we managed to measure the phase of a mode-locked dark pulse for the first time. Other pulse measurement techniques such as dispersion scan could benefit as well as the underlying optimisation problem is similar. To further improve the performance of pulse characterisation techniques, we also present the Sigma Check, which is a general algorithmic step that aims to reduce the likelihood of stagnating at local minima. This is achieved by performing an image-recognition step that correctly identifies and counteracts local minimums.QC 2025-08-11</p