| 1. |
- Ahmed, Hesham, et al.
(författare)
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Effect of the Ash from H2‐Rich Carbonaceous Materials on the Physicochemical Properties of Raceway Slag and Coke Reactivity
- 2020
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Ingår i: Steel Research International. - : John Wiley & Sons. - 1611-3683 .- 1869-344X. ; 91:11
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Tidskriftsartikel (refereegranskat)abstract
- The iron and steel industry is one of the most important sectors worldwide, and it has a great impact on the global economy; however, this sector is still highly dependent on fossil carbon. To decrease this dependency, approaches to partially replace the injected pulverized coal with secondary, highly reactive, renewable (biomass) and H2‐rich materials have been studied. The injection of such materials is expected to significantly decrease the emitted CO2 from blast furnaces. However, due to the different ash composition of these alternative materials (especially alkali and alkaline earth metals) compared to that of ordinary injected coal, these materials are expected to alter the raceway slag properties and affect the coke reactivity. In the present article, the effect of the ash from different hydrogen‐rich carbonaceous materials on the raceway slag physicochemical properties as well as coke reactivity is reported. The melting characteristics of the ash briquettes in contact with the coke and wettability of the melted ash on the coke surface are determined visually using an optical heating microscope. The effect of the ash on the coke reactivity is studied by means of thermogravimetry under a continuous flow of CO2.
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| 2. |
- Hellmer, Erica, 1980-
(författare)
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Att bevara för att använda? : Om användares och användninges betydelse i arkivet
- 2023
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In times of increasing demands of access and use of records and archives, among the current political and private initiatives of both efficiency and innovation, and among developments of e-services and digitalization, new participatory initiatives are created. In the current times, as both users and potential users are gaining bigger roles as co-creators of records, it sets new demands on how these participatory perspectives could be contextualized in the archival practice.The aim of the thesis was to extend the knowledge of users, use of archives and archival records. Presented in the thesis, several studies have been conducted with the purpose of exploring how users and use are described in the literature of archival science, how use have been considered by different professions when analogue processes turn digital, and exploring what dictates the need of use. The studies have had a qualitative stance where the methods of data collection have consisted of interviews and a group interview, a focus group, a systematic literature review, and a participatory observation.The results show that the development of e-services is based on the need of the end-users/customers and that there is a risk that the role of the archival profession may disappear behind political incentives. Results also show that ‘user’ is a concept that is utterly bound to the heterogeneous contexts in which they are conceptualized, and that the user studies conducted within the archival domain elucidates the importance of gaining knowledge of the users’ perception and behavior. The thesis also shows that the concept of societal embeddedness as an analytical tool can be used to visualize the need of use of records. This can be used as a way to describe and contextualize the user perspective in a broader societal context.
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| 3. |
- Ingberg, Edvin, 1988-, et al.
(författare)
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RT-PCR cycle threshold value in combination with visual scoring of chest computed tomography at hospital admission predicts outcome in COVID-19
- 2022
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Ingår i: Infectious Diseases. - : Taylor & Francis. - 2374-4235 .- 2374-4243. ; 54:6, s. 431-440
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: COVID-19 has a most variable prognosis. Several risk factors for an unfavourable outcome have been identified including extensive lung involvement on chest CT and high viral load estimated by RT-PCR cycle threshold (Ct) values. We investigated Ct value for outcome prediction, relation between Ct value and extent of lung involvement on chest CT and the combination of Ct value and chest CT lung involvement to predict outcome in COVID-19.METHODS: Population-based retrospective study on all patients (n = 286) hospitalised for COVID-19 in Örebro Region, Sweden, between 1 March and 31 August 2020. Nasopharyngeal samples and chest CT at hospital admission were evaluated in relation to outcome of COVID-19.RESULTS: Both Ct value and chest CT lung involvement were independently associated with risk for ICU admission or death. Lung involvement was superior as a single parameter, but addition of Ct value increased the prediction performance. Ct value was especially useful to identify patients with high risk for severe disease despite limited lung involvement.CONCLUSIONS: The addition of RT-PCR Ct value to the assessment of lung involvement on chest CT adds valuable prognostic information in COVID-19. We believe that this information can be used to support clinical decision-making when managing COVID-19 patients.
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| 4. |
- Klint, Erik, 1989, et al.
(författare)
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Återinför tvättstugan - för klimatets skull
- 2022
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Ingår i: Dagens samhälle. - 1652-6511. ; 2 mars
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Nya lägenheter byggs nästan uteslutande med privata tvättmaskiner i badrummet – trots att de ger betydligt större klimatpåverkande utsläpp per tvätt än tvättstugor. Allmännyttan borde göra gemensamma tvättutrymmen till standard.
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| 5. |
- Lindborg, Jenny, et al.
(författare)
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Systemperspektiv för effektiv produktion och användning av vätgas viakoppling till fjärrvärme
- 2023
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Detta projekt har analyserat sektorkopplingars möjligheter att ta vara på restflöden som genereras vid produktion av vätgas genom elektrolys samt hur dessa flöden kan generera ekonomiska och systemmässiga fördelar. Förutsättningen har varit att all el köps in externt för spotpris. Projektet har redovisat i detalj hur restvärmen, som uppstår i elektrolysen, kan tillgodogöras som fjärrvärme och därigenom öka processens verkningsgrad från cirka 66 till 95 %. EU:s mål om produktion av 10 miljoner ton vätgas per år till 2030 innebär att det bildas 230 TWh restvärme, motsvarande fyra gånger Sveriges totala fjärrvärmeenergi. Det visar potentialen och vikten av att värmeöverskottet nyttjas i framtida investeringar. För varje kilo vätgas som produceras bildas åtta kilo syrgas, som kan användas i för att förbättra förbränningen i en avfallspanna. Alternativt kan syrgasen transporteras till ett närliggande vattenreningsverk, vilket minskar elanvändningen för de pumpar som idag cirkulerar luft i de biologiska reningsstegen. Svenska kraftnät har skapat flera olika marknader för systemtjänster. Vätgasproduktion har goda förutsättningar att delta, särskilt med FCR-D. Analyserna visar att intäkterna från dessa tjänster kan vara större än både restvärmen och syrgasen, förutsatt att restvärmen inte ersätter bränslen som har en högre kostnadsprofil, som exempelvis bio-olja eller pellets. I dessa fall får restvärmen ett betydligt högre värde. Sektorkopplingen mot fjärrvärme skapar ett resurseffektivt energisystem där alla restflöden kan komma till nytta. Vätgaslager kan också bidra till ett mer robust och resilient energisystem, med möjligheter att förse kritiska verksamheter med reservkraft eller för att starta lokala elnät i ö-drift. För bästa lönsamhet, utifrån befintliga data om elpriser och vätgasens värde, bör vätgasen säljas vidare som bränsle till tunga transport eller som råvara till industrier istället för att lagras för senare omvandling tillbaka till el. I en framtid, där behov av elgenerering för balanskraft kan öka och samtidigt krävas vara koldioxidneutral, kan dock situationen bli annorlunda. Baserat på indata och förutsättningar från omvärldsanalyserna visar att kostnaden för att producera vätgas (kr/kg) minimeras när elektrolysen är i drift cirka 80 % av årets timmar eftersom avskrivningskostnaderna annars blir högre i relation till producerad mängd vätgas. Förutsatt avsättning för vätgasen bör produktionen dras ner enbart vid de allra högsta elpriserna. Scenariot ”gas-to-power” har inte visat sig lönsamt, baserat på de förutsättningar som använts. Historiska elpriser har inte varit tillräckligt höga, tillräckligt ofta för att en extra investering i en gasturbin eller bränslecell ska betala sig. Samtidigt kan det vara missvisande att jämföra priser där dagens fossila bränslen ingår eftersom dessa bränslen på sikt inte är något alternativ. Även om sektorkopplingen till fjärrvärme ökar intäktsmöjligheterna för vätgasproduktion så finns fortfarande ett antal osäkra parametrar som påverkar lönsamheten och investeringsviljan. Dessa specificeras och diskuteras i denna och dess underliggande rapporter.
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| 6. |
- Moberg, Louise, et al.
(författare)
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Vulvar cancer incidence and net survival in Sweden 1960 to 2019: A population-based national study
- 2024
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Ingår i: Acta Obstetricia et Gynecologica Scandinavica. - 0001-6349 .- 1600-0412. ; 103:3, s. 561-571
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: Vulvar cancer is a rare gynecological cancer affecting mostly older women. The aim of this population-based study was to investigate the incidence and net survival of vulvar cancer in Swedish women from 1960 to 2019. Material and methods: Data were retrieved from the mandatory Swedish Cancer Registry consisting of all women diagnosed with vulvar cancer between 1960 and 2019. Only women with a morphologically verified diagnosis of vulvar cancer were included. The individuals were then further matched with the Swedish Death Registry up until May 31, 2020. Results: In total, 8499 women were included with the following morphologies: squamous cell carcinoma 7250 (85.8%), malignant melanoma 539 (6.4%), adenocarcinoma 401 (4.8%) and other: 259 (3.1%). More than 50% of vulvar cancer cases occurred in women aged between 65 and 84 years of age. The 5-year age-standardized net survival increased from 53.0% (95% confidence interval [CI] 48.9–57.5) in 1960 to 72.1% (95% CI 68.8–75.5) in 2019. The proportion of adenocarcinoma among all cases increased from 2.0% to 8.7% between the 1960s and 2010s and an increase in age-standardized 5-year net survival was found for adenocarcinoma. Conclusions: The age-standardized incidence of vulvar cancer cases in Sweden was stable between 1960 and 2019. During the study period, an increase in adenocarcinoma and a decrease in malignant melanoma cases was found. Five-year net survival increased by 20 percent units during the study period. For squamous cell carcinoma, an increased age-specific 5-year net survival was observed for all age groups, apart for women aged ≥85.
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| 7. |
- Sandberg, Karin, et al.
(författare)
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IPOS - Innovations in wood-based building materials and products
- 2021
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- IPOS Swedish wood- Innovation POtential for the biobased Society, is a coordination project within Bioinnovation Construction & Design. The coordination project IPOS has been led by Karin Sandberg RISE Research Institutes of Sweden. This report consists of results from four subprojects (SP) within IPOS compiled by the project leaders. Innovations and development of new wood-based products to increase the value of the raw material have been in focus in the four subprojects. Common for the subprojects are the effort for developing new materials, processes, products and manufacturing methods as well as market and product development DeProtion -Design, Product development & Communication (SP1) The purpose has been to collaboratively develop a general innovative product development model that supports the wood industry's development of products with value-adding design and/or with the support of design automation. Compiled by Fredrik Henriksson, Linköping University in chapter 2. Demand driven finishing of Swedish wood (SP2) The purpose has been to ensure efficient processes that can deliver the right wood material for continued processing within the value chains for industrial wood construction, as well as exterior and interior carpentry products. Compiled by Bror Sundqvist Luleå University of Technology in chapter 3. The Facade of the city Swift, Stylish, Smart (SP3) The purpose has been to increase the market for wooden facades and therefore develop a concept for an attractive functional facade system of pine adapted for urban environment with regards to design, fire, competitive cost and environmental profile. Compiled by Karin Sandberg Research Institutes of Sweden in chapter 4. Outdoor load-bearing timber structures (SP4) The purpose has been to extend the scope of chemically modified wood (acetylation) for load-bearing outdoor structures and Scandinavian wood species, pine and birch. Compiled by Erik Serrano, Lund University in chapter 5. In all sub-projects work has aimed at developing new materials, processes and products and at the same time taking into account market- and communication aspects. The sub-projects have in various ways developed and improved products made from Swedish wood species, primarily Scots pine and spruce, but also birch. Through collaboration, via IPOS, the sharing of knowledge between the projects has contributed to strengthening the wood value chain more than the individual projects could have done. The main conclusions are below summarized under the three headings “Renewal for the pine market”, Development of innovative products” and “New businesses and markets”.
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| 8. |
- Sundqvist, Tobias, et al.
(författare)
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Boosted Ensemble Learning for Anomaly Detection in 5G RAN
- 2020
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Ingår i: Artificial Intelligence Applications and Innovations, AIAI 2020. - Cham : Springer. - 9783030491604 - 9783030491611 ; , s. 15-30
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Konferensbidrag (refereegranskat)abstract
- The emerging 5G networks promises more throughput, faster, and more reliable services, but as the network complexity and dynamics increases, it becomes more difficult to troubleshoot the systems. Vendors are spending a lot of time and effort on early anomaly detection in their development cycle and majority of the time is spent on manually analyzing system logs. While main research in anomaly detection uses performance metrics, anomaly detection using functional behaviour is still lacking in depth analysis. In this paper we show how a boosted ensemble of Long Short Term Memory classifiers can detect anomalies in the 5G Radio Access Network system logs. Acquiring system logs from a live 5G network is difficult due to confidentiality issues, live network disturbance, and problems to repeat scenarios. Therefore, we perform our evaluation on logs from a 5G test bed that simulate realistic traffic in a city. Our ensemble learns the functional behaviour of an application by training on logs from normal execution time. It can then detect deviations from normal behaviour and also be retrained on false positive cases found during validation. Anomaly detection in RAN shows that our ensemble called BoostLog, outperforms a single LSTM classifier and further testing on HDFS logs confirms that BoostLog also can be used in other domains. Instead of using domain experts to manually analyse system logs, BoostLog can be used by less experienced trouble shooters to automatically detect anomalies faster and more reliable.
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| 9. |
- Sundqvist, Tobias, 1976-, et al.
(författare)
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Bottleneck identification and failure prevention with procedural learning in 5G RAN
- 2023
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Ingår i: 2023 IEEE/ACM 23rd International Symposium on Cluster, Cloud and Internet Computing (CCGrid). - : IEEE. - 9798350301199 - 9798350301205 ; , s. 426-436
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Konferensbidrag (refereegranskat)abstract
- To meet the low latency requirements of 5G Radio Access Networks (RAN), it is essential to learn where performance bottlenecks occur. As parts are distributed and virtualized, it becomes troublesome to identify where unwanted delays occur. Today, vendors spend huge manual effort analyzing key performance indicators (KPIs) and system logs to detect these bottlenecks. The 5G architecture allows a flexible scaling of microservices to handle the variation in traffic. But knowing how, when, and where to scale is difficult without a detailed latency analysis. In this article, we propose a novel method that combines procedural learning with latency analysis of system log events. The method, which we call LogGenie, learns the latency pattern of the system at different load scenarios and automatically identifies the parts with the most significant increase in latency. Our evaluation in an advanced 5G testbed shows that LogGenie can provide a more detailed analysis than previous research has achieved and help troubleshooters locate bottlenecks faster. Finally, through experiments, we show how a latency prediction model can dynamically fine-tune the behavior where bottlenecks occur. This lowers resource utilization, makes the architecture more flexible, and allows the system to fulfill its latency requirements.
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| 10. |
- Sundqvist, Tobias, 1976-
(författare)
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Machine learning-based diagnostics and observability in mobile networks
- 2023
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- To meet the high-performance and reliability demands of 5G, the Radio Access Network (RAN) is moving to a cloud-native architecture. The new microservice architecture promises increased operational efficiency and a shorter time-to-market, but it also comes with a price. The new distributed and virtualized architecture is far more complex than ever before, and with the increasing number of features it brings, troubleshooting becomes more difficult. So far, RAN troubleshooters have relied on their expertise to analyze systems manually, but the ever-growing data and increased complexity make it challenging to grasp system behavior.This thesis contributes threefold, where the proposed machine learning and statistical methods help RAN troubleshooters find deviations in system logs, identify the root cause of these deviations, and improve the system's observability. These methods learn the application's behavior from the system logs events and can identify behavior deviations from many different aspects. The thesis also demonstrates how observability can be improved by using a new software instrumentation guideline. The guideline enables the tracking of systemized procedures and enhances system understanding. The purpose of the guideline is to make RAN developers aware that machine learning can utilize debug information and help their troubleshooting process. To familiarize the reader with the research area, the challenges, and methods that can be used to detect anomalies, perform root cause analysis and observe RAN system behavior. The proposed research methods are integrated and tested in an advanced 5G test bed to evaluate the methods' accuracy, speed, system impact, and implementation cost.The results demonstrate the advantage of using machine learning and statistical methods when troubleshooting the behavior of RAN. Machine learning methods, similar to those presented in this thesis, may help those who troubleshoot RAN and accelerate the development of 5G. The thesis ends with presenting potential research areas where this research could be further developed and applied, both in RAN and other systems.
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