Publikationer från Umeå universitet
Not a member yet
55455 research outputs found
Sort by
Semantic Retrieval of Swedish Support Cases - Adapting a pre-trained language model for Domain-Specific Text Reuse
No full textThis thesis was conducted in collaboration with WSP and addresses the challenge of improving knowledge reuse in large-scale support operations through enhanced retrieval of historical support cases. Support case data often consists of unstructured free-text entries, making it difficult to find relevant past cases using traditional keyword-based search methods. The project focuses on the DeDU support system used by WSP in Sweden, which contains over 25,000 support cases described in Swedish. The core aim is to develop a semantic search solution that can identify previous cases similar in meaning, even if they are described using different words or phrases. To achieve this, a transformer-based language model (KB-BERT), pretrained on general Swedish text, was adapted to the domain of support cases using masked language modeling. The model was then further fine-tuned in a Siamese network with contrastive learning, allowing it to distinguish between semantically similar and dissimilar case descriptions. The evaluation was based on both quantitative and qualitative analyses, using unsupervised clustering and manual inspection, since labeled data was not available. Results show that the domain-adapted and contrastively fine-tuned model produces more coherent groupings of support cases and achieves higher accuracy in retrieving relevant cases compared to the base model. The solution demonstrates the practical value of modern semantic modeling techniques for industrial support operations, enabling support staff to find similar historical cases more efficiently and reducing repeated problem solving. It is recommended that future work considers the integration of user feedback and further domain-specific tuning to continually improve retrieval accuracy
Socialt entreprenörskap för långsiktig näringslivutveckling i Norrlands inland
No full text Ofta talas om Norrland i stort, men skillnaderna är stora mellan Norrland i sin helhet och dess inland när det kommer till resurser, avstånd och befolkningsmängd. I Norrlands inland finns 10 kommuner som gemensamt gått ihop för att samverka och tillsammans stärka utvecklingen. Sedan år 2000 har befolkningen minskat i dessa kommuner, vilket orsakat stora utmaningar. Hittills har inte några åtgärder lyckats vända den negativa utvecklingen och framtiden präglas av osäkerhet. År 2018 infördes ett statligt bidrag med mål att stärka dessa kommuners förutsättningar att utveckla näringsliv och företagsklimat. I budgetpropositionen för år 2025 fastställdes dock att regeringen upphör med utbetalningen av detta bidrag. Det har skapat en debatt där det ifrågasattes huruvida regeringen verkligen har insikt i utmaningarna som finns för glesbygdskommuner med begränsade resurser. Förståelsen för förhållanden på landsbygden och deras effekt på sociala företag är bristande, och det behövs mer kunskap om hur landsbygdens förutsättningar påverkar för att kunna förstå socialt entreprenörskap i den kontexten. Många modeller inom entreprenörskap utgår från storstadsregioner och går inte enkelt att applicera på en glesbygd. Tidigare forskning utgår från de sociala entreprenörernas perspektiv och det finns därmed begränsad förståelse kring om och hur kommuner arbetar med främjandet av socialt entreprenörskap. Syftet med denna uppsats är att analysera hur kommuner i Norrlands inland ser på socialt entreprenörskap, hur de främjar det för att utveckla sina näringsliv. En djupare förståelse för socialt entreprenörskap på landsbygden kan fås genom att identifiera betydelsen av begreppet, vilka insatser som vidtas för att främja socialt entreprenörskap och vilka utmaningar som finns. Forskningsfrågan lyder således; “Hur arbetar kommunerna i Norrlands inland med främjandet av socialt entreprenörskap för att skapa en långsiktig näringslivsutveckling?” Uppsatsen utgår från en kvalitativ forskningsmetod och bygger på semi-strukturerade intervjuer med respondenter som har insyn i entreprenörskap och näringslivsutveckling i sex kommuner med anknytning till Region 10. Den empiriska datan insamlades, transkriberades och analyserades därefter genom tematisk analys. Uppsatsen har identifierat hur begreppet socialt entreprenörskap används och tolkas, vilka främjandeinsatser som vidtas i kommunerna, vilka bakomliggande utmaningar som kan begränsa arbetet samt vilken framtidstro som finns i dessa kommuner. Resultaten kan inspirera och ge kunskap till andra glesbygdskommuner med liknande förutsättningar arbetet med främjande av socialt entreprenörskap för en hållbar näringslivsutveckling. Uppsatsen ger även en djupare förståelse av socialt entreprenörskap i en ny kontext, Norrlands inland
Ligand-limited oxidation of ciprofloxacin by Mn(III)
No full textMn(III) species play critical roles in determining the environmental fate of antibiotics released into natural systems. However, their reactivity is strongly influenced by complexation reactions with (in)organic ligands. This study investigates the impact of Mn(III) complexation with pyrophosphate (PP), a model environmental ligand, on the redox-driven degradation of ciprofloxacin (CIP), a widely used antibiotic and environmental contaminant. Spectroscopic analysis and thermodynamic modeling revealed that Mn(III)-PP complexes initially dissociate into MnOH2+ species, which can then disproportionate and form MnO2 colloids. Both dissociation and disproportionation reactions had comparable trends at pH 4 and 7, with reactivities that were strongly dependent on Mn(III):PP ratios. The progress of CIP oxidation following direct coordination with Mn compounds over time was sigmoidal, with an initial lag phase attributed to Mn(III)-PP complex dissociation and disproportionation. CIP degradation was predominantly governed by pH, with maximal rate constants decreasing from k = 0.390 h−1 at pH 3 to k = 0.065 h−1 at pH 5, and no CIP removal under circumneutral to alkaline conditions. Cyclic voltammetry also confirmed that the strongly pH-dependent redox potential of the Mn(III)/Mn(II) couple aligned with facile CIP oxidation under acidic conditions. These collective findings indicated that ligand complexation, such as with PP, enhanced Mn(III) stability and mitigated dissociation and disproportionation reactions. The new insight provided by this work on the speciation and redox activity of Mn(III) should thereby be considered for understanding ciprofloxacin degradation in contaminated water systems
A multi-strategy antimicrobial discovery approach reveals new ways to treat Chlamydia
No full textWhile the excessive use of broad-spectrum antibiotics is a major driver of the global antibiotic resistance crisis, more selective therapies remain unavailable for the majority of bacterial pathogens. This includes the obligate intracellular bacterial pathogens of the genus Chlamydia, which cause millions of urogenital, ocular, and respiratory infections each year. Conducting a comprehensive search of the chemical space for novel antichlamydial activities, we identified over 60 compounds that are chemically diverse, structurally distinct from known antibiotics, non-toxic to human cells, and highly potent in preventing the growth of Chlamydia trachomatis in cell cultures. Some blocked C. trachomatis development reversibly, while others eradicated both established and persistent infections in a bactericidal manner. The top molecules displayed compelling selectivity, yet broad activity against diverse Chlamydia strains and species, including both urogenital and ocular serovars of C. trachomatis, as well as Chlamydia muridarum and Chlamydia caviae. Some compounds also displayed synergies with clinically used antibiotics. Critically, we found the most potent antichlamydial compound to inhibit fatty acid biosynthesis via covalent binding to the active site of Chlamydia FabH, identifying a new mechanism of FabH inhibition and highlighting a possible way to selectively treat Chlamydia infections
Samband mellan spatial distribution av död ved i vattendrag och geomorfisk habitat diversitetsindex efter vattendrags restaurering : GIS studier på vattendraget Vargån i norra Sverige.
No full textIn Sweden, historical timber floating led to channelization and biodiversity loss when natural obstructions such as instream wood (IW) and boulders were removed from rivers. IW requirements are ≥ 1m long and a mid-diameter of ≥ 10cm. IW enhances stream complexity by increasing flow resistance, creating hydraulic heterogeneity, and forming geomorphic landforms i.e., geomorphic units, that support habitat diversity and biodiversity. The aim of restoration is to reverse channelization, improving ecological conditions and climate change resilience, but many projects fail to achieve that and long-term sustainability. This study uses GIS analysis of uncrewed-aerial-vehicle collected images from the Vargån tributary, northern Sweden, to investigate changes in IW over time and their relationship to geomorphic habitat complexity. Results show an increase in the number of IW pieces and clustering post-restoration. A temporary decline one year post-restoration was likely due to spring flooding and natural recruitment the following year. Immobile wood remained stable probably because of how it was placed whereas mobile wood was found in the channel, either flushed away or stabilized in cluster over the years. The main results show an increase of IW with temporal variabilities in IW metrics during the extended process of river rehabilitation following river restoration. Geomorphic unit diversity showed statistically significant correlations with IW number and average IW complexity. IW clusters which were expected to have the strongest correlation showed no correlation with geomorphic unit diversity index. Geomorphic unit diversity index, initially high in 2022, declined in 2023, and increased again two years post-restoration in 2024, may reflect both anthropogenic restoration impacts and the river´s natural self-healing processes such as eroding banks naturally, and recruiting instream wood. This study shows that over time when IW stabilizes, forming less porous and hydraulically complex structures, natural recruitment of IW will increase, and a continued increase in channel heterogeneity and i.e., in geomorphic diversity can be expected. However, a higher diversity index does not necessarily indicate the optimal ecological or sustainable state for that specific river.
Replace heating of industrial buildings with waste heat instead of steam
No full textA heating system for industrial buildings at Domsjö Fabriker has been investigated in this work. The current system is a heat exchanger system that heats a circulation circuit of water with 3.5 bar steam. The purpose of the project is to find technical solutions to reduce the use of steam and investigate whether it is possible to heat the facilities with waste heat from the pulp- and paper industry. To find what kind of system is suitable for the building, the availability of waste heat and the current heating have been analyzed. Proposals for technical solutions were then made and discussed with suppliers. Today, Domsjö both produces its own steam and buys 15% of the total usage from an external supplier. A total of 1080 GWh/year of steam is used in the mill area both in processes and for heating buildings. The analyzed system uses 18 GWh/year of steam to heat the buildings. Waste heat is available in a collection tank. Here, water from different parts of the process is collected and the water temperature is around 36℃. The supply temperature of the circulation circuit for heating should reach 90℃ during the coldest winter days. Therefore, a new heat exchanger system will not be sufficient if waste heat is to be the new heat source for heating. Different solutions with heat pumps were investigated. It resulted in four different proposals for solutions with the goal of saving the current circulation circuit. Investment costs, payback periods and annuities of the different proposals are calculated. The steam used for heating, which currently costs the factory just over XX million SEK/year, can be replaced with a heat pump system that has an annuity of 6 million SEK/year with a total investment cost of 20 million SEK. The savings of using a heat pump system instead of steam heating via heat exchangers will be X million SEK/year for the proposal with the largest savings. The conclusion for the project is therefore that all proposals for technical solutions developed can cover the maximum heating demand. The different proposals mainly differ in terms of investment cost, payback period and size of the system. This means that several different factors need to be considered to conclude an optimal proposal for Domsjö Fabriker. Some numbers in the report are replaced with X. This is because the numbers are confidential.
Wireless bridge for FCT-fixtures
No full textThis thesis presents the development of a wireless bridge for Functional Circuit Test(FCT) fixtures used in testing PCBAs. Traditional wired connections in FCT setupsintroduce challenges such as limited flexibility, cable clutter, and space constraints. Toaddress these issues, a prototype wireless communication system was created using acombination of a Single Board Computer (SBC), DAQ, and a custom software stack builtin Python. The solution utilizes TCP-based data transmission, CRC for integrity checking,and AES encryption to ensure data security. Performance evaluations indicate that thewireless system can handle measurement instructions and data return at a competitivespeed, although not yet fully on par with wired alternatives. The results show promisefor replacing wired communication in test fixtures with wireless solutions, enabling moreflexible and efficient test setups in industrial environments.Detta examensarbete behandlar utvecklingen av en trådlös brygga för FCT-fixturer (Fun-ctional Circuit Test) som används vid testning av kretskort (PCBA). Traditionella tråd-bundna lösningar innebär problem såsom begränsad flexibilitet, kabeltrassel och platsbristi testfixturer. För att lösa dessa problem har en prototyp för trådlös kommunikation ut-vecklats med hjälp av en Single Board Computer (SBC), DAQ och egenutvecklad mjukvarai Python. Lösningen använder TCP för dataöverföring, CRC för att verifiera dataintegri-tet och AES för kryptering. Prestandatester visar att den trådlösa lösningen klarar avatt hantera mätinstruktioner och överföra data med god hastighet, även om det ännuinte helt matchar en trådbunden lösning. Resultaten visar att den trådlösa bryggan harpotential att ersätta kablar i testfixturer och därmed möjliggöra mer flexibla och effektivatestuppställningar i industriella miljöer
Design and development of an automated test fixture for testing a pinch valve unit
No full textDetta examensarbete har genomförts i samarbete med Cytiva Sweden AB i Umeå, och syftar till att designa och utveckla ett automatiserat testfixtur för en klämventilsenhet. Ventilenheten ingår i ett större medicintekniskt instrument som kan användas inom forskning och utveckling av biologiska läkemedel. Målet med projektet är att ska en testfixtur som kan säkerställa kvalitén av monterade ventilenheter genom att automatiskt identifiera felmonteringar eller defekta komponenter innan de integreras i slutinstrumentet. Testfixturen som skapades i detta projekt är en proof-of-concept på hur en testfixtur kan fungera. Den skapade testfixturen kan genomföra tester, samt rapportera testresultat till både databas och ett grafiskt gränssnitt. Projektet omfattar både hårdvaru- och mjukvarudesign, samt ett inbyggt system baserat på en Raspberry Pi Pico, kommunikation via UART och Doris-protokollet, samt implementation av testlogik i Python. Arbetet inkluderar även ett inledande arbete för att CE-märka testfixturen, med en fokus på säkerhet, ergonomin och riskhantering. Resultatet visar att testfixturen kan tillförlitligt identifiera vanliga monteringsfel, såsom felkopplade sensorer och lufttrycksslangar.This thesis has been carried out in collaboration with Cytiva Sweden AB in Umeå and aims to design and develop an automated test fixture for a pinch valve unit. This unit is part of a larger system that can be used in research and development of biological drugs. The thesis aims to create a test fixture that can ensure the quality of an assembled valve unit by automatically detecting misassembled or defective components before they are integrated into the final device. The test fixture that has been created after this thesis is proof-of-concept of how a test fixture can work in a production setting. The created test fixture can perform test, and report test results to both a graphical user interface and a database. This project includes both hardware and software design, as well as an embedded system based on a Raspberry Pi Pico, communication with UART and Doris, and implementation of test logic in Python. This work also includes the initial work to CE-mark the test fixture, with a focus on safety, ergonomics and risk management. The results show that the test fixture can reliably identify common assembly errors, such as incorrectly connected sensors and air pressure hoses.
Extend & Pretend : En analys av kommersiella fastighetslån inom den svenska banksektorn
No full textThis study investigates how Swedish banks recognized and managed credit risk in the commercial real estate (CRE) sector during a period of market and financial stress from 2022 to 2023. We focus on three key areas: (i) to what extent banks recognized increased credit risk in distressed loans, (ii) whether loan maturity extensions became more frequent during stressed periods and were targeted toward distressed borrowers, and (iii) how banks’ capital buffers influenced the timeliness of credit risk recognition. Using loanlevel data from some of Sweden’s major banks, we analyse Probability of Default (PD) assessments, IFRS 9 stage distribution, and loan extension decisions. The descriptive analysis reveals rising financial stress in 2022–2023, evidenced by increased PDs, a growing share of Stage 2 and Stage 3 loans, and a higher proportion of distressed loan extensions, particularly among loans originated before 2020. Our empirical results show that banks with thinner capital buffers were systematically less responsive to deteriorating credit conditions: they assigned lower PDs to distressed loans, were less likely to assign loans to Stage 2 or 3, and more frequently extended loan maturity. These findings point to capitaldriven incentives to delay loss recognition, especially under stress. While Swedish banks remained well-capitalized overall, our results highlight how bank-specific capital positions can influence credit risk recognition practices in ways that may affect financial stability.Denna studie undersöker hur svenska banker identifierar och hanterar kreditrisk inom sektorn för kommersiella fastigheter (CRE) under en period av marknads- och finansiell stress från 2022 till 2023. Vi fokuserar på tre centrala områden: (i) i vilken utsträckning bankerna erkände ökad kreditrisk i nödlidande lån, (ii) huruvida färlängningar av lånets löptid blev vanligare under perioder av stress och riktades mot nödlidande låntagare, samt (iii) hur bankernas kapitalbuffertar påverkade sannolikheten att kreditrisk erkändes. Med hjälp av lånedata på mikronivå från några av Sveriges största banker analyserar vi bedömningar av sannolikhet för fallissemang (PD), IFRS 9-stadiefördelning samt beslut om läneförlängning. Den deskriptiva analysen visar på ökande finansiell stress under 2022–2023, vilket återspeglas i stigande PD-värden, en växande andel lån i stadier 2 och 3, samt en högre andel förlängningar av nödlidande lån– särskilt bland lån som beviljades före 2020. Våra empiriska resultat visar att banker med lägre kapitalbuffertar systematiskt var mindre responsiva mot försämrade kreditvillkor: de tilldelade lägre PD-värden till nödlidande lån, var mindre benägna att klassificera lån i stadier 2 eller 3, och förlängde löptiden oftare. Dessa resultat tyder på kapitalkänsliga incitament att fördröja förlustredovisning, särskilt under perioder av stress. Även om svenska banker överlag var välkapitaliserade, belyser våra resultat hur bankernas individuella kapitalpositioner kan påverka praxis för erkännande av kreditrisk pö ett sätt som kan ha betydelse för den finansiella stabiliteten
Swedish local free churches’ use of instagram : a negotiated approach to social media engagement
No full textThis study examines how local Swedish Free Churches use the social media platform Instagram. It builds on data from nine local churches’ Instagram accounts gathered between February and April 2024, encompassing 952 individual posts (including stories) and accompanying captions. Drawing on Adrienne Shaw’s (2017) work, the study not only investigates the technical affordances these congregations employ but observes what these platforms afford religious institutions. It thus challenges the technological determinism often prevalent in previous research, which tends to equate successful social media use with two-way communication and views its absence as a failure. The findings show that, rather than conforming to dominant platform norms, these churches take a negotiated approach, adapting their use of Instagram to serve their values and goals. The analysis highlights how these religious institutions translate their core values onto the platform by emphasizing congregational commitment, personal piety, and biblical authority in their posts, thus bridging their offline and online identities. The local churches included in the study belong to the Uniting Church in Sweden, the Pentecostal Alliance of Independent Churches, and the Evangelical Free Churc