Publikationer från Uppsala Universitet
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Measurement of cross sections of e+ e- → KS0 KS0ψ(3686) from √s=4.682 to 4.951 GeV
No full textThe process e(+) e(-) -> K-S(0) K-S(0)psi(3686) is studied by analyzing e(+) e(-) collision data samples collected at eight center-of-mass energies ranging from 4.682 to 4.951 GeV with the BESIII detector operating at the BEPCII collider, corresponding to an integrated luminosity of 4.1 fb(-1). Observation of the e(+) e(-) -> K-S(0) K-S(0)(3686) process is found for the first time with a statistical significance of 6.3 sigma, and the cross sections at each center-ofmass energy are measured. The ratio of cross sections of e(+) e(-) -> K-S(0) K-S(0)psi(3686) relative to e(+) e(-) -> K+ K-psi(3686) is determined to be sigma(e(+) e(-) -> K-S(0) K-S(0)psi(3686))/sigma(e(+)e(-) -> K+ K- psi(3686)) = 0.45 +/- 0.25, which is consistent with the prediction based on isospin symmetry. The uncertainty includes both statistical and systematic contributions. Additionally, the K-S(0)psi(3686) invariant mass distribution is found to be consistent with three-body phase space. The significance of a contribution beyond three-body phase space is only 0.8 sigma.For complete list of authors see http://dx.doi.org/10.1007/JHEP02(2025)120</p
AI as a tool for more efficient construction processes
No full textThe construction industry has long struggled with low productivity and a slow pace of digital transformation. Artificial intelligence (AI) holds significant potential to address these inefficiencies, particularly within the tendering process, a resource-intensive and repetitive phase. This study explores how AI-based tools can enhance efficiency in the tendering process at Sh Bygg, a mid-sized Swedish construction company. Six AI use cases were identified through interviews with internal stakeholders at Sh Bygg and subsequently evaluated using the Design Thinking framework DVF: Desirability, Viability, and Feasibility. The evaluation was based on insights from internal and external stakeholders, supported by relevant literature. The analysis shows that the use case sorting of tender documents received the highest overall score, reflecting strong desirability, technical and organizational feasibility, and clear business value. In contrast, use cases such as boundary lists and concept work and system selection scored lower, mainly due to high organizational and technical complexity. The study concludes that targeted AI adoption in low-risk, high-impact areas can deliver substantial value while aligning with Sh Bygg’s strategic goals, such as improved knowledge transfer and reduced dependence on individual expertise. These findings may support other mid-sized construction firms in identifying and prioritizing viable AI initiatives.
Dual-Path Attention Fusion with Enhanced Depthmap for Face Frontalization
No full textPose variations and non-ideal shooting conditions significantly hinder the adoption and widespread use of facial recognition technology. When the captured image is a profile view, the loss or distortion of key facial features drastically reduces recognition accuracy. To address this issue, this paper proposes a face frontalization approach based on a dual-path feature extraction and attention fusion mechanism, emphasizing the natural advantages of depth maps in depicting facial geometry and occlusion relationships. Specifically, a dual-branch architecture is designed to separately extract features from the depth map and the RGB image of the original profile, and an attention mechanism is leveraged to explicitly guide and complement the RGB features with depth information, thereby achieving efficient multi-modal fusion. This fusion method not only preserves the texture details from the RGB image but also fully exploits the geometric cues in the depth map, effectively enhancing the clarity, realism, and identity retention of the generated images. Experimental results show that the proposed method outperforms existing approaches in both visual fidelity and cross-pose recognition accuracy, demonstrating robust performance and significant potential for real-world applications
Artificiell intelligens i rekryteringsprocesser : En studie av rekryterares upplevelser, arbetsmetoder och etiska överväganden
No full textThe aim of this study was to explore how recruiters perceive the use of artificial intelligence (AI) in recruitment processes. To address this, ten semi-structured interviews were conducted with recruiters from various companies. The interviews were held digitally and lasted approximately 15 minutes. A thematic analysis was then carried out on the collected data. The Technology Acceptance Model (TAM) and the theory of expansive learning formed the theoretical framework of the study and were used to analyze the findings. The results showed that recruiters largely perceive AI as a time-efficient and useful tool, but its use requires them to develop technical skills. The study also revealed divided opinions on whether AI reinforces or reduces biases, as well as its limitations in assessing soft qualities such as empathy and social competence. The conclusions of the study indicated that AI tools should be seen as a complement to, rather than a replacement for, the human factor in the recruitment process. Furthermore, the findings suggest that AI tends to function better in active recruitment than in passive recruitment. As technology continues to advance, it may become possible in the future for certain parts of the process to fully replace human involvement.Syftet med studien var att undersöka hur rekryterare upplever användningen av artificiell intelligens (AI) i rekryteringsprocesser. För att belysa detta genomfördes tio semistrukturerade intervjuer med rekryterare från olika företag. Intervjuerna skedde digitalt och pågick i ungefär 15 minuter. Därefter genomfördes en tematisk analys av den insamlade empirin. Technology Acceptance Model (TAM) och teorin om expansivt lärande utgjorde studiens teoretiska ramverk och användes för att analysera empirin. Resultatet visade att rekryterare i hög utsträckning upplever AI som ett tidseffektivt och användbart verktyg, men användningen kräver att rekryterare utvecklar tekniska färdigheter. Det framkom också delade åsikter om att AI antingen förstärker eller minskar fördomar, samt AI:s begränsningar i att bedöma mjuka värden som empati eller social kompetens. Slutsatserna av studien visade att AI-verktyg bör ses som ett komplement i rekryteringsprocessen och inte som en ersättning för den mänskliga faktorn, och det framgår fungera bättre vid aktiv rekrytering än vid passiv rekrytering. I takt med att tekniken utvecklas kan det i framtiden bli möjligt att vissa delar av processen helt ersätter den mänskliga faktorn.
Correlation between crud and element concentrations in boilingwater reactors
No full textCrud is a collective term for deposits of various elements on fuel rods in a reactor. These deposits can affect heat transfer within the reactor, which in turn can lead to increased mechanical stress on the fuel rods. Through regular inspections and analytical campaigns, Westinghouse has compiled extensive data on crud in the Nordic reactors. Using sensors that measure flow rates and concentrations of elements in piping systems connected to the reactors, data is available on how much has theoretically been deposited in the reactor systems. The purpose of this study has been to investigate the relationship between the theoretical deposition levels and the measured amounts of crud from various campaigns for the Nordic boiling water reactors. The study has focused solely on the elements iron, nickel, and chromium. The work was carried out as a document and literature study, including regression analysis of data from Westinghouse crud scraping campaigns and mass balance calculations for Nordic boiling water reactors. The focus was on fuel assemblies with a burnup greater than 30 MWd/kgU, as these are considered to have developed a stable crud layer. Based on the results and the analysis, it is evident that the study’s objective has been partially achieved. The results show a clear correlation for iron, while no correlation was found for nickel and chromium. The analysis shows that iron plays a clearly dominant role in crud formation and that the data quality for iron is better compared to nickel and chromium
Spatial Variability in Carbon Burial in the Littoral Zone of a Boreal Lake
No full textBoreal lakes have a significant role in carbon burial and are global carbon sinks. The spatial variability of organic carbon burial in the littoral zone of Lake Lumpen, a vegetation-rich boreal-brown water lake in Uppland County, Sweden, was investigated. This project specifically addresses the influence of water depth within the littoral zone for sediment carbon content and accumulation, as well as its predominant source. Sediment cores were collected along the littoral zone’s gradient using a Livingstone corer and an additional pelagic zone core for comparative analysis. The collected sediment samples were analysed for carbon and nitrogen content, water content, and C:N ratio to quantify burial rates and infer organic matter sources and degradation states. The results showed minimal variability in carbon burial rates (2.3–2.8 gC/m²/ yr) across the littoral transects, with no significant gradient along the core depth profile and no significant relationship between water depth and burial rate. The lack of spatial trends suggests that the hydrodynamic redistribution homogenises burial rates within the littoral zone. While direct comparison within the pelagic zone was limited due to insufficient sample size and core depth, carbon concentrations in the littoral sediment were consistently higher than in the pelagic core, which is consistent with greater organic matter accumulation in vegetated areas. Similarly, C:N ratios in the littoral zone were higher than in the pelagic zone, and intra-littoral variability was low. This indicates that the consistently higher C:N in all littoral cores compared to the pelagic core indicates a higher contribution of OM from terrestrial plants and emergent macrophytes. These findings suggest that the sediment redistribution process may mask the expected gradient in sediment carbon content and burial within the littoral. The organic carbon content and C:N ratio were very homogeneous across the littoral zone. The study underscores the need to account for littoral burial when assessing lake carbon sinks and provides new insights into carbon cycling in boreal lake ecosystems. Key words: Boreal lakes, Burial rate, Carbon sequestration, C:N ratio, Lake Lumpen, Littoral zone, Macrophytes, Organic matter, Sediment cores, Spatial variability.
Strategic Leadership in Complex Organizations : A Case Study of the Management Structure in Compulsory Education within Region Gotland
No full textStudien undersöker hur det strategiska ledarskapet inom Region Gotlands ledningsorganisation för grundskolan kan utvecklas. I ett komplext organisatoriskt landskap där operativa krav ofta dominerar, blir det strategiska utrymmet begränsat. Syftet med arbetet är att analysera nuläget och identifiera förbättringsåtgärder som främjar en mer hållbar och långsiktig styrning. Studien genomfördes som en kvalitativ fallstudie med metodtriangulering, där semistrukturerade intervjuer, enkät, e-postdialoger och dokumentanalys kombinerades. Det teoretiska ramverket bygger på modeller av bland annat Mintzberg, Yukl och Kotter och belyser organisationsstruktur, ledarskapsbeteenden och förändringsarbete. Resultatet visar att bristen på tydlig ansvarsfördelning, otillräckliga stödfunktioner och högt operativt tryck hämmar strategiskt arbete. Rektorer och avdelningschefer efterfrågar bättre struktur, legitimitet och resurser för att kunna verka strategiskt. Studien föreslår konkreta åtgärder, bland annat tydligare styrdokument, förbättrade ledningssystem och kompetensstärkande insatser. Slutsatsen är att strategiskt ledarskap inte enbart handlar om personligt engagemang utan om att skapa organisatoriska förutsättningar. Ett levande ledningssystem kan ge riktning och stabilitet åt förändringsarbetet och möjliggöra ett mer professionellt och långsiktigt ledarskap i offentlig sektor.This study examines how strategic leadership within the management organization of compulsory schools in Region Gotland can be developed. In a complex organizational context where operational demands often dominate, strategic capacity is limited. The purpose of the study is to analyze the current situation and identify improvement measures that support more sustainable and long-term governance. The study was conducted as a qualitative case study using method triangulation, combining semi-structured interviews, a survey, email correspondence, and document analysis. The theoretical framework is based, among others, on models by Mintzberg, Yukl, and Kotter, highlighting organizational structure, leadership behaviors, and change management. The results show that unclear responsibilities, inadequate support functions, and high operational pressure hinder strategic work. Principals and department heads call for clearer structures, legitimacy, and resources to enable strategic leadership. The study proposes concrete measures, including improved governance documents, enhanced management systems, and competence development initiatives. The conclusion is that strategic leadership is not only a matter of individual commitment but also about establishing organizational conditions. A living management system can provide direction and stability for change efforts and enable a more professional and long-term leadership in the public sector
Carbon fiber reinforcement compared to steel as areinforcement method
No full textThis study analyzes how the choice between steel and carbon fiber reinforcement affects climate impact, use of space and the cost of strengthening existing concrete structures. A constructed case study is evaluated, in which columns and slabs have reduced load-bearing capacity and require reinforcement. The investigation is based on carbon fiber products from the company Sika and the steel reinforcement is from an anonymous manufacturer. The analysis is based on approximate bearing capacity calculations to acquire the required amount of reinforcement materials, which is translated to weight, volume and carbon dioxide equivalents for each material. A sensitivity analysis was conducted to account for uncertainties by varying the degree of structural damage and the climate impact of carbon fiber. Results show that in the studied case carbon fiber reinforcement reduces material weight by 97% and volume by 87% compared to steel. Despite having higher emissions per kilogram the low weight of carbon fiber leads to a 70% reduction in climate impact. The purchase cost increases by approximately 128%. The study concludes that carbon fiber is a suitable alternative in confined projects with strict environmental goals. It also aims to raise awareness within the construction industry that carbon fiber exists as a practical and sustainable alternative for structural reinforcement.
Student experiences and perspectives on decolonising global health education : a qualitative study across five Nordic countries
No full textBackground Decolonisation has become a global health priority, addressing inequities rooted in colonial histories that continue to shape power dynamics and knowledge systems. Nordic global health programmes bring together students and faculty from diverse backgrounds in a region defined by inclusive ideals but shaped by underexamined colonial legacies. This context offers a valuable setting to examine how decolonial perspectives are integrated or overlooked in global health education. Objective To explore students’ perspectives on decolonisation in global health education, focusing on their understanding, experiences, and views on potential pedagogical change. Methods A qualitative study involving 72 students from Nordic countries and other world regions, enrolled in global health programmes at 11 academic institutions across five Nordic countries. Fourteen focus group discussions were conducted, and the data were analysed using qualitative content analysis principles. Results Students shared nuanced understandings of systemic power imbalances in global health practice and education and expressed the need for structural changes. They identified gaps in curricula and pedagogy, including limited integration of decolonial perspectives and inequities in knowledge production. Students called for more inclusive and culturally relevant curricula that reflect diverse contexts. They emphasised student agency in shaping education while acknowledging barriers such as institutional biases and inconsistent faculty engagement. Conclusions Decolonising Nordic global health education is a long-term process requiring sustained institutional commitment. Student-informed strategies include embedding reflexivity into curricula, engaging with Nordic colonial histories, and designing reciprocal international learning arrangements. While context-specific, these findings may inform broader efforts to decolonise global health educational practices
Effect of preoperative exercise on postoperative complications after colorectal cancer surgery in older people with low physical fitness : The CANOPTIPHYS randomised controlled trial
No full textIntroduction: Preoperative exercise may decrease the risk of complications after major abdominal cancer surgery but the amount of time available for such interventions is limited. Our objective was to evaluate the effect of a short-term preoperative exercise program on postoperative outcomes in older patients with low physical fitness scheduled to undergo colorectal cancer surgery. Materials and Methods: This was a randomised controlled, multicentre trial where patients scheduled for colorectal cancer surgery were considered for inclusion if they were >= 65 years of age and had low maximal walking speed. The intervention took place in participants' home environments and included inspiratory muscle training, aerobic training, and strength exercises for two to three weeks before surgery. Exercise was of high intensity and frequency, with at least six sessions supervised by a physiotherapist. Additionally, participants were instructed to perform unsupervised exercises, aiming for a total frequency of inspiratory muscle training twice daily, and aerobic and strength exercises five to six times per week. A control group underwent surgery without preoperative exercise. The primary endpoint was occurrence of any complications within 30 days after surgery. Secondary outcomes were postoperative length of hospital stay and discharge destination. Binary logistic regression and Mann-Whitney U test were used to analyse outcomes. Results: A total of 51 patients were included in the intention-to-treat analysis and allocated to preoperative exercise (n = 27) or usual care (n = 24). The proportion of participants with at least one postoperative complication was 48.1 % in the intervention group and 62.5 % in the control group. There was no effect of preoperative exercise on the odds of developing postoperative complications (OR: 0.56, 95 % CI: 0.18-1.71) nor on discharge to another care facility instead of home (OR: 0.98, 95 % CI: 0.29-3.27). The median length of stay in nights was 5 (IQR: 4-6) for the intervention group and 5.5 (IQR: 4-7.8) for the control group (p = 0.55). Discussion: In this study of older patients with low physical fitness awaiting colorectal cancer surgery, we could not demonstrate an influence of preoperative exercise on postoperative complications, discharge destination or length of hospital stay. These results should be interpreted with caution due to a small sample size