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Sökning: WFRF:(Holmström David)

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1.
  • Iglesias, Maria Jesus, et al. (författare)
  • Elevated plasma complement factor H related 5 protein is associated with venous thromboembolism
  • 2023
  • Ingår i: Nature Communications. - : Springer Nature. - 2041-1723. ; 14:1
  • Tidskriftsartikel (refereegranskat)abstract
    • Venous thromboembolism (VTE) is a common, multi-causal disease with potentially serious short- and long-term complications. In clinical practice, there is a need for improved plasma biomarker-based tools for VTE diagnosis and risk prediction. Here we show, using proteomics profiling to screen plasma from patients with suspected acute VTE, and several case-control studies for VTE, how Complement Factor H Related 5 protein (CFHR5), a regulator of the alternative pathway of complement activation, is a VTE-associated plasma biomarker. In plasma, higher CFHR5 levels are associated with increased thrombin generation potential and recombinant CFHR5 enhanced platelet activation in vitro. GWAS analysis of ~52,000 participants identifies six loci associated with CFHR5 plasma levels, but Mendelian randomization do not demonstrate causality between CFHR5 and VTE. Our results indicate an important role for the regulation of the alternative pathway of complement activation in VTE and that CFHR5 represents a potential diagnostic and/or risk predictive plasma biomarker.
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2.
  • Bruzelius, Maria, et al. (författare)
  • PDGFB, a new candidate plasma biomarker for venous thromboembolism : results from the VEREMA affinity proteomics study
  • 2016
  • Ingår i: Blood. - : American Society of Hematology. - 0006-4971 .- 1528-0020. ; 128:23, s. E59-E66
  • Tidskriftsartikel (refereegranskat)abstract
    • There is a clear clinical need for high-specificity plasma biomarkers for predicting risk of venous thromboembolism (VTE), but thus far, such markers have remained elusive. Utilizing affinity reagents from the Human Protein Atlas project and multiplexed immuoassays, we extensively analyzed plasma samples from 2 individual studies to identify candidate protein markers associated with VTE risk. We screened plasma samples from 88 VTE cases and 85 matched controls, collected as part of the Swedish Venous Thromboembolism Biomarker Study, using suspension bead arrays composed of 755 antibodies targeting 408 candidate proteins. We identified significant associations between VTE occurrence and plasma levels of human immunodeficiency virus type I enhancer binding protein 1 (HIVEP1), von Willebrand factor (VWF), glutathione peroxidase 3 (GPX3), and platelet-derived growth factor beta (PDGFB). For replication, we profiled plasma samples of 580 cases and 589 controls from the French FARIVE study. These results confirmed the association of VWF and PDGFB with VTE after correction for multiple testing, whereas only weak trends were observed for HIVEP1 and GPX3. Although plasma levels of VWF and PDGFB correlated modestly (rho similar to 0.30) with each other, they were independently associated with VTE risk in a joint model in FARIVE (VWF P < .001; PDGFB P = .002). PDGF. was verified as the target of the capture antibody by immunocapture mass spectrometry and sandwich enzyme-linked immunosorbent assay. In conclusion, we demonstrate that high-throughput affinity plasma proteomic profiling is a valuable research strategy to identify potential candidate biomarkers for thrombosis-related disorders, and our study suggests a novel association of PDGFB plasma levels with VTE.
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3.
  • Ageberg, Eva, et al. (författare)
  • Balance in Single-limb Stance in Healthy Subjects - Reliability of Testing. Procedure and The Effect of Short-duration Sub-maximal Cycling
  • 2003
  • Ingår i: BMC Musculoskeletal Disorders. - : Springer Science and Business Media LLC. - 1471-2474. ; 4
  • Tidskriftsartikel (refereegranskat)abstract
    • Background: To assess balance in single-limb stance, center of pressure movements can be registered by stabilometry with force platforms. This can be used for evaluation of injuries to the lower extremities. It is important to ensure that the assessment tools we use in the clinical setting and in research have minimal measurement error. Previous studies have shown that the ability to maintain standing balance is decreased by fatiguing exercise. There is, however, a need for further studies regarding possible effects of general exercise on balance in single-limb stance. The aims of this study were: 1) to assess the test-retest reliability of balance variables measured in single-limb stance on a force platform, and 2) to study the effect of exercise on balance in single-limb stance, in healthy subjects. Methods: Forty-two individuals were examined for test-retest reliability, and 24 individuals were tested before (pre-exercise) and after (post-exercise) short-duration, sub-maximal cycling. Amplitude and average speed of center of pressure movements were registered in the frontal and sagittal planes. Mean difference between test and retest with 95% confidence interval, the intraclass correlation coefficient, and the Bland and Altman graphs with limits of agreement, were used as statistical methods for assessing test-retest reliability. The paired t-test was used for comparisons between pre- and post-exercise measurements. Results: No difference was found between test and retest. The intraclass correlation coefficients ranged from 0.79 to 0.95 in all stabilometric variables except one. The limits of agreement revealed that small changes in an individual's performance cannot be detected. Higher values were found after cycling in three of the eight stabilometric variables. Conclusions: The absence of systematic variation and the high ICC values, indicate that the test is reliable for distinguishing among groups of subjects. However, relatively large differences in an individual's balance performance would be required to confidently state that a change is real. The higher values found after cycling, indicate compensatory mechanisms intended to maintain balance, or a decreased ability to maintain balance. It is recommended that average speed and DEV 10; the variables showing the best reliability and effects of exercise, be used in future studies.
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4.
  • Ageberg, Eva, et al. (författare)
  • Balance in single-limb stance in patients with anterior cruciate ligament injury - Relation to knee laxity, proprioception, muscle strength, and subjective function
  • 2005
  • Ingår i: The American journal of sports medicine. - : SAGE Publications. - 1552-3365 .- 0363-5465. ; 33:10, s. 1527-1535
  • Tidskriftsartikel (refereegranskat)abstract
    • Background: It has been shown previously that an anterior cruciate ligament injury may affect postural control, measured by balance in single-limb stance. To our knowledge, no studies have reported the influence of measures of impairment on postural control after such an injury. Purpose: To assess the influence of knee laxity, proprioception, and muscle strength on balance in single-limb stance and to study the correlation between balance in single-limb stance and subjective estimation of extremity function. Study Design: Cross-sectional study; Level of evidence, 3. Methods: A total of 36 patients with a unilateral, nonoperated, nonacute anterior cruciate ligament injury were examined with regard to anterior knee laxity, proprioception, muscle strength, and stabilometry (amplitude and average speed of the center of pressure movements). Subjective estimation of extremity function was measured on a visual analog scale. Results: The multiple regression analysis showed that high knee laxity values were associated with high amplitude values and low average speed. Poor proprioception and high muscle strength values were associated with low average speed among the women only. Low amplitude values correlated with better subjective function. Conclusion: Anterior knee laxity, proprioception, and muscle strength seem to play a role in maintaining balance in single-limb stance. Patients with low amplitude values in stabilometry were those with better subjective function.
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8.
  • Ageberg, Eva, et al. (författare)
  • The effect of short-duration sub-maximal cycling on balance in single-limb stance in patients with anterior cruciate ligament injury: a cross-sectional study
  • 2004
  • Ingår i: BMC Musculoskeletal Disorders. - : Springer Science and Business Media LLC. - 1471-2474. ; 5
  • Tidskriftsartikel (refereegranskat)abstract
    • Background: It has previously been shown that an anterior cruciate ligament (ACL) injury may lead to impaired postural control, and that the ability to maintain postural control is decreased by fatigue in healthy subjects. To our knowledge, no studies have reported the effect of fatigue on postural control in subjects with ACL injury. This study was aimed at examining the effect of fatigue on balance in single-limb stance in subjects with ACL injury, and to compare the effects, and the ability to maintain balance, with that of a control group of uninjured subjects. Methods: Thirty-six patients with unilateral, non-operated, non-acute ACL injury, and 24 uninjured subjects were examined with stabilometry before (pre-exercise) and immediately after (post-exercise) short-duration, sub-maximal cycling. In addition, the post-exercise measurements were compared, to evaluate the instantaneous ability to maintain balance and any possible recovery. The amplitude and average speed of center of pressure movements were registered in the frontal and sagittal planes. The paired t-test was used for the intra-group comparisons, and the independent t-test for the inter-group comparisons, with Bonferroni correction for multiple comparisons. Results: No differences were found in the effects of exercise between the patients and the controls. Analysis of the post-exercise measurements revealed greater effects or a tendency towards greater effects on the injured leg than in the control group. The average speed was lower among the patients than in the control group. Conclusions: The results of the present study showed no differences in the effects of exercise between the patients and the controls. However, the patients seemed to react differently regarding ability to maintain balance in single-limb stance directly after exercise than the control group. The lower average speed among the patients may be an expression of different neuromuscular adaptive strategies than in uninjured subjects.
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9.
  • Ahlén Bergman, Emma, et al. (författare)
  • Increased CD4+ T cell lineage commitment determined by CpG methylation correlates with better prognosis in urinary bladder cancer patients
  • 2018
  • Ingår i: Clinical Epigenetics. - : BMC. - 1868-7083 .- 1868-7075. ; 10
  • Tidskriftsartikel (refereegranskat)abstract
    • BACKGROUND: Urinary bladder cancer is a common malignancy worldwide. Environmental factors and chronic inflammation are correlated with the disease risk. Diagnosis is performed by transurethral resection of the bladder, and patients with muscle invasive disease preferably proceed to radical cystectomy, with or without neoadjuvant chemotherapy. The anti-tumour immune responses, known to be initiated in the tumour and draining lymph nodes, may play a major role in future treatment strategies. Thus, increasing the knowledge of tumour-associated immunological processes is important. Activated CD4+ T cells differentiate into four main separate lineages: Th1, Th2, Th17 and Treg, and they are recognized by their effector molecules IFN-γ, IL-13, IL-17A, and the transcription factor Foxp3, respectively. We have previously demonstrated signature CpG sites predictive for lineage commitment of these four major CD4+ T cell lineages. Here, we investigate the lineage commitment specifically in tumour, lymph nodes and blood and relate them to the disease stage and response to neoadjuvant chemotherapy.RESULTS: Blood, tumour and regional lymph nodes were obtained from patients at time of transurethral resection of the bladder and at radical cystectomy. Tumour-infiltrating CD4+ lymphocytes were significantly hypomethylated in all four investigated lineage loci compared to CD4+ lymphocytes in lymph nodes and blood (lymph nodes vs tumour-infiltrating lymphocytes: IFNG -4229 bp p < 0.0001, IL13 -11 bp p < 0.05, IL17A -122 bp p < 0.01 and FOXP3 -77 bp p > 0.05). Examination of individual lymph nodes displayed different methylation signatures, suggesting possible correlation with future survival. More advanced post-cystectomy tumour stages correlated significantly with increased methylation at the IFNG -4229 bp locus. Patients with complete response to neoadjuvant chemotherapy displayed significant hypomethylation in CD4+ T cells for all four investigated loci, most prominently in IFNG p < 0.0001. Neoadjuvant chemotherapy seemed to result in a relocation of Th1-committed CD4+ T cells from blood, presumably to the tumour, indicated by shifts in the methylation patterns, whereas no such shifts were seen for lineages corresponding to IL13, IL17A and FOXP3.CONCLUSION: Increased lineage commitment in CD4+ T cells, as determined by demethylation in predictive CpG sites, is associated with lower post-cystectomy tumour stage, complete response to neoadjuvant chemotherapy and overall better outcome, suggesting epigenetic profiling of CD4+ T cell lineages as a useful readout for clinical staging.
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10.
  • Ahlgren, Karin, et al. (författare)
  • De stora restaureringarna : Från Uppsala domkyrka till Skokloster
  • 2004
  • Rapport (populärvet., debatt m.m.)abstract
    • De stora restaureringarna har varit årets tema. Genom att dokumentera och analysera teori och praktik i några av 1800- och 1900-talets största restaureringar - från genomgripande stilrestaureringar till ett mer återhållsamt och tekniskt skon­samt synsätt. Därmed får vi också ett bättre underlag även för dagens ställningsta­gande.Föremål för våra studier är Uppsala domkyrka, Gripsholms slott, Vreta kloster­kyrka, Gustav 11I:s paviljong i Haga, Kungapalatset i Vadstena och Skoklosters slott. Vi hoppas att denna utställning skall bidra till en kritisk hållning och en ökad kunskap om restaureringskonsten, som kvalificerad yrkesuppgift, tidsspegel för historiesyn och som gestaltningsideal.
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11.
  • Andrews, David J., et al. (författare)
  • Plasma observations during the Mars atmospheric "plume" event of March-April 2012
  • 2016
  • Ingår i: Journal of Geophysical Research - Space Physics. - 2169-9380 .- 2169-9402. ; 121:4, s. 3139-3154
  • Tidskriftsartikel (refereegranskat)abstract
    • We present initial analyses and conclusions from plasma observations made during the reported "Mars plume event" of March-April 2012. During this period, multiple independent amateur observers detected a localized, high-altitude "plume" over the Martian dawn terminator, the cause of which remains to be explained. The estimated brightness of the plume exceeds that expected for auroral emissions, and its projected altitude greatly exceeds that at which clouds are expected to form. We report on in situ measurements of ionospheric plasma density and solar wind parameters throughout this interval made by Mars Express, obtained over the same surface region but at the opposing terminator. Measurements in the ionosphere at the corresponding location frequently show a disturbed structure, though this is not atypical for such regions with intense crustal magnetic fields. We tentatively conclude that the formation and/or transport of this plume to the altitudes where it was observed could be due in part to the result of a large interplanetary coronal mass ejection (ICME) encountering the Martian system. Interestingly, we note that the only similar plume detection in May 1997 may also have been associated with a large ICME impact at Mars.
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12.
  • Berntorp, Erik, et al. (författare)
  • Treatment of haemophilia A and B and von Willebrand's disease : summary and conclusions of a systematic review as part of a Swedish health-technology assessment
  • 2012
  • Ingår i: Haemophilia. - : Wiley. - 1351-8216 .- 1365-2516. ; 18:2, s. 158-165
  • Forskningsöversikt (refereegranskat)abstract
    • In an ongoing health-technology assessment of haemophilia treatment in Sweden, performed by the governmental agency Dental and Pharmaceutical Benefits Agency (TLV; tandvårds-och läkemedelsförmånsverket), the Swedish Council on Health Technology Assessment (SBU; statens beredning för medicinsk utvärdering) was called upon to evaluate treatment of haemophilia A and B and von Willebrand's disease (VWD) with clotting factor concentrates. To evaluate the following questions: What are the short-term and long-term effects of different treatment strategies? What methods are available to treat haemophilia patients that have developed inhibitors against factor concentrates? Based on the questions addressed by the project, a systematic database search was conducted in PubMed, NHSEED, Cochrane Library, EMBASE and other relevant databases. The literature search covered all studies in the field published from 1985 up to the spring of 2010. In most instances, the scientific evidence is insufficient for the questions raised in the review. Concentrates of coagulation factors have good haemostatic effects on acute bleeding and surgical intervention in haemophilia A and B and VWD, but conclusions cannot be drawn about possible differences in the effects of different dosing strategies for acute bleeding and surgery. Prophylaxis initiated at a young age can prevent future joint damage in persons with haemophilia. The available treatment options for inhibitors have been insufficiently assessed. The economic consequences of various treatment regimens have been insufficiently analysed. Introduction of national and international registries is important.
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13.
  • Carlsson, My, et al. (författare)
  • Impact of physical pre-treatment of source-sorted organic fraction of municipal solid waste on greenhouse-gas emissions and the economy in a Swedish anaerobic digestion system
  • 2015
  • Ingår i: Waste Management. - : Elsevier BV. - 0956-053X .- 1879-2456. ; 38, s. 117-125
  • Tidskriftsartikel (refereegranskat)abstract
    • Several methods for physical pre-treatments of source sorted organic fraction of municipal solid waste (SSOFMSW) before for anaerobic digestion (AD) are available, with the common feature that they generate a homogeneous slurry for AD and a dry refuse fraction for incineration. The selection of efficient methods relies on improved understanding of how the pre-treatment impacts on the separation and on the slurry’s AD. The aim of this study was to evaluate the impact of the performance of physical pre-treatment of SSOFMSW on greenhouse-gas (GHG) emissions and on the economy of an AD system including a biogas plant with supplementary systems for heat and power production in Sweden. Based on the performance of selected Swedish facilities, as well as chemical analyses and BMP tests of slurry and refuse, the computer-based evaluation tool ORWARE was improved as to accurately describe mass flows through the physical pre-treatment and anaerobic degradation. The environmental and economic performance of the evaluated system was influenced by the TS concentration in the slurry, as well as the distribution of incoming solids between slurry and refuse. The focus to improve the efficiency of these systems should primarily be directed towards minimising the water addition in the pre-treatment provided that this slurry can still be efficiently digested. Second, the amount of refuse should be minimised, while keeping a good quality of the slurry. Electricity use/generation has high impact on GHG emissions and the results of the study are sensitive to assumptions of marginal electricity and of electricity use in the pre-treatment.
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14.
  • Chen, Antony, et al. (författare)
  • Heterologous T cells can help restore function in dysfunctional hepatitis C virus nonstructural 3/4A-specific T cells during therapeutic vaccination.
  • 2011
  • Ingår i: Journal of immunology. - : The American Association of Immunologists. - 1550-6606 .- 0022-1767. ; 186:9, s. 5107-18
  • Tidskriftsartikel (refereegranskat)abstract
    • The hepatitis C virus (HCV)-specific T cell response in patients with chronic HCV is dysfunctional. In this study, we aimed at restoring immunological function through therapeutic vaccination in a transgenic mouse model with impaired HCV-specific T cell responses due to a persistent presence of hepatic HCV nonstructural (NS)3/4A Ags. The HCV-specific T cells have an actively maintained dysfunction reflected in reduced frequency, impaired cytokine production, and impaired effector function in vivo, which can be partially restored by blocking regulatory T cells or programmed cell death ligand 1. We hypothesized that the impairment could be corrected by including sequences that created a normal priming environment by recruiting "healthy" heterologous T cells and by activating innate signaling. Endogenously expressed hepatitis B core Ag (HBcAg) can recruit heterologous T cells and activate TLR (TLR7) signaling. Hence, by combining HCV NS3/4A with different forms of HBcAg we found that heterologous sequences somewhat improved activation and expansion of NS3/4A-specific T cells in a wild-type host. Importantly, the signals provided by HBcAg effectively restored the activation of HCV-specific T cells in a tolerant NS3/4A-transgenic mouse model. The adjuvant effect could also be transferred to the priming of dysfunctional HLA-A2-restricted NS3-specific T cells in vivo. Thus, recruiting healthy heterologous T cells to the site of priming may also help restore HCV-specific responses present in a chronically infected host.
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15.
  • Chiang, Michael F., et al. (författare)
  • International Classification of Retinopathy of Prematurity, Third Edition
  • 2021
  • Ingår i: Ophthalmology. - : Elsevier. - 0161-6420 .- 1549-4713. ; 128:10, s. 51-68
  • Tidskriftsartikel (refereegranskat)abstract
    • Purpose: The International Classification of Retinopathy of Prematurity is a consensus statement that creates a standard nomenclature for classification of retinopathy of prematurity (ROP). It was initially published in 1984, expanded in 1987, and revisited in 2005. This article presents a third revision, the International Classification of Retinopathy of Prematurity, Third Edition (ICROP3), which is now required because of challenges such as: (1) concerns about subjectivity in critical elements of disease classification; (2) innovations in ophthalmic imaging; (3) novel pharmacologic therapies (e.g., antievascular endothelial growth factor agents) with unique regression and reactivation features after treatment compared with ablative therapies; and (4) recognition that patterns of ROP in some regions of the world do not fit neatly into the current classification system.Design: Review of evidence-based literature, along with expert consensus opinion. Participants: International ROP expert committee assembled in March 2019 representing 17 countries and comprising 14 pediatric ophthalmologists and 20 retinal specialists, as well as 12 women and 22 men.Methods: The committee was initially divided into 3 subcommittees-acute phase, regression or reactivation, and imaging-each of which used iterative videoconferences and an online message board to identify key challenges and approaches. Subsequently, the entire committee used iterative videoconferences, 2 in-person multiday meetings, and an online message board to develop consensus on classification.Main Outcome Measures: Consensus statement.Results: The ICROP3 retains current definitions such as zone (location of disease), stage (appearance of disease at the avascular-vascular junction), and circumferential extent of disease. Major updates in the ICROP3 include refined classification metrics (e.g., posterior zone II, notch, subcategorization of stage 5, and recognition that a continuous spectrum of vascular abnormality exists from normal to plus disease). Updates also include the definition of aggressive ROP to replace aggressive-posterior ROP because of increasing recognition that aggressive disease may occur in larger preterm infants and beyond the posterior retina, particularly in regions of the world with limited resources. ROP regression and reactivation are described in detail, with additional description of long-term sequelae.Conclusions: These principles may improve the quality and standardization of ROP care worldwide and may provide a foundation to improve research and clinical care.
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16.
  • Dakkak, Anas, et al. (författare)
  • Continuous deployment in software-intensive system-of-systems
  • 2023
  • Ingår i: Information and Software Technology. - : Elsevier BV. - 0950-5849 .- 1873-6025. ; 159
  • Tidskriftsartikel (refereegranskat)abstract
    • Context: While continuous deployment is popular among web-based software development organizations, adopting continuous deployment in software-intensive system-of-systems is more challenging. On top of the challenges arising from deploying software to a single software-intensive embedded system, software-intensive system-of-systems (SiSoS) add a layer of complexity as new software undergoes an extensive field validation applied to individual components of the SiSoS, as well as the overall SiSoS, to ensure that both legacy and new functionalities are working as desired. Objectives: This paper aims to study how SiSoS transitions to continuous deployment by exploring how continuous deployment impacts field testing and validation activities, how continuous deployment can be practiced in SiSoS, and to identify the success factors that companies need to consider when transitioning to continuous deployment. Method: We conducted a case study at Ericsson AB focusing on the embedded software of the Third Generation Radio Access Network (3G RAN). The 3G RAN consists of two large-scale software-intensive embedded systems, representing a simple SiSoS composed of two systems. 3G RAN software was the first to transition to continuous deployment and is used as a reference case for other products within Ericsson AB. Results: Software deployment, in addition to field testing and validation, have transitioned from being a discrete activity performed at the end of software development to a continuous process performed in parallel to software development. Further, our study reveals an orchestrating approach for software deployment, which allows pre/post validation of legacy behavior and new features in a shorter release and deployment cadence. Furthermore, we identified the essential success factors that organizations should consider when transitioning to continuous deployment. Conclusion: Transition to continuous deployment, in addition to field testing and validation, shall be considered and planned carefully. In this paper, we provide a set of success factors and orchestration technique that helps organization when transitioning to continuous deployment in the software-intensive embedded system-of-systems context.
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17.
  • Dakkak, Anas, et al. (författare)
  • Towards Continuous Data Collection from In-service Products : Exploring the Relation Between Data Dimensions and Collection Challenges
  • 2021
  • Ingår i: 2021 28th Asia-Pacific Software Engineering Conference (APSEC). - : IEEE. - 9781665437844 - 9781665437851
  • Konferensbidrag (refereegranskat)abstract
    • Data collected from in-service products play an important role in enabling software-intensive embedded systems suppliers to embrace data-driven practices. Data can be used in many different ways such as to continuously learn and improve the product, enhance post-deployment services, reduce operational cost or create a better user experience. While there is no shortage of possible use cases leveraging data from in-service products, software-intensive embedded systems companies struggle to continuously collect data from their in-service products. Often, data collection is done in an ad-hoc way and targeting specific use cases or needs. Besides, few studies have investigated data collection challenges in relation to the data dimensions, which are the minimum set of quantifiable data aspects that can define software-intensive embedded product data from a collection point of view. To help address data collection challenges, and to provide companies with guidance on how to improve this process, we conducted a case study at a large multinational telecommunications supplier focusing on data characteristics and collection challenges from the Radio Access Networks (RAN) products. We further investigated the relations of these challenges to the data dimensions to increase our understanding of how data dominions contribute to the challenges.
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18.
  • Dakkak, Anas, et al. (författare)
  • Towards Continuous Data Collection from In-service Products: Exploring the Relation between Data Dimensions and Collection Challenges
  • 2021
  • Ingår i: Proceedings - Asia-Pacific Software Engineering Conference, APSEC. - 1530-1362. ; 2021-December, s. 243-252
  • Konferensbidrag (refereegranskat)abstract
    • Data collected from in-service products play an important role in enabling software-intensive embedded systems suppliers to embrace data-driven practices. Data can be used in many different ways such as to continuously learn and improve the product, enhance post-deployment services, reduce operational cost or create a better user experience. While there is no shortage of possible use cases leveraging data from in-service products, software-intensive embedded systems companies struggle to continuously collect data from their in-service products. Often, data collection is done in an ad-hoc way and targeting specific use cases or needs. Besides, few studies have investigated data collection challenges in relation to the data dimensions, which are the minimum set of quantifiable data aspects that can define software-intensive embedded product data from a collection point of view. To help address data collection challenges, and to provide companies with guidance on how to improve this process, we conducted a case study at a large multinational telecommunications supplier focusing on data characteristics and collection challenges from the Radio Access Networks (RAN) products. We further investigated the relations of these challenges to the data dimensions to increase our understanding of how data dominions contribute to the challenges.
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19.
  • Elander, Maria, et al. (författare)
  • Indikatorer för en resurseffektiv avfallshantering
  • 2014
  • Rapport (övrigt vetenskapligt/konstnärligt)abstract
    • Det övergripande målet med projektet var att ta fram ett antal indikatorer för att kunna visa på hur resurseffektiv avfallshanteringen är och jämföra hur utvecklingen blir över tiden. Detta innebär att indikatorerna: ska åskådliggöra måluppfyllelsen för uppsatta mål samt göra det möjligt att följa upp utvecklingen för svensk avfallshantering på kommunal/regional och nationell nivå på ett enkelt sätt . Trots att informationen och kunskapen om avfallshanteringen ständigt har förbättrats i samhället så har ändå svårigheterna med att mäta och följa upp utvecklingen ökat. De mål som satts för avfallshanteringen har stadigt förstärkts vilket har skapat ett alltmer komplext avfallshanteringssystem. Det märks tydligt på dagens ambitioner att utveckla de övre delarna i avfallshierarkin, det vill säga avfallsprevention och materialåtervinning. Dessa delar är betydligt svårare att beskriva, mäta och följa upp jämfört med de nedre behandlingsstegen. Att utveckla indikatorer kring förebyggande och frikoppling har varit ett viktigt mål för indikatorprojektet. I projektet har indikatorerna analyserats och testats i fem olika fallstudier (tre på kommunal nivå och två på nationell nivå varav en för hushållsavfall enligt Avfall Sverige och en för nationellt totalt avfall kopplat till den officiella avfallsstatistiken). Följande kriterier har använts och uppfylls: Relevans Datatillgång Kvalitet Kommunicerbarhet och användbarhet Indikatorerna som har tagits fram: Är neutrala och användbara på den nivå de avser, det vill säga på kommunal/ regional och/eller nationell nivå. Är utformade för att kunna mäta förändring och/eller förändringstakten årsvis Täcker varje steg av avfallshierarkin (det vill säga ge en indikation på resurseffektiviteten för respektive steg samt totalt). Mäter förändringen i resurseffektivitet för hela systemet över tid (det vill säga beskriva en position i avfallshierarkin). Indikatorerna kan användas på kommunal nivå eller på nationell nivå. Indikatorerna avser att ge beslutsfattare, kommuner och kommunala avfallsbolag stöd i planeringen och uppföljningen av den kommunala avfallshanteringen. Tre typer av indikatorer är utvecklade: Förflyttningsindikatorer – speglar avfallshanteringssystemets nivå och utveckling i sin helhet. Trappstegsindikatorer – beskriver och mäter utvecklingen på varje enskilt trappsteg i avfallshierarkin (avfallstrappan) minus de rejektmängder som uppkommer      innan själva behandlingen (till exempel sorteringsrester från      materialåtervinning). Bakgrundsindikatorer – tar hänsyn till allt avfall som behandlas på respektive trappsteg även avfall som uppkommer vid annan behandling (till exempel askor från förbränning). Indikatorerna presenteras samlat i Bilaga A. Målsättningen är att de framtagna indikatorerna ska integreras med existerande avfallsrapportering i kommunerna (till exempel i Avfall Web) och i den nationella uppföljningen som Naturvårdsverket genomför. En användarvägledning har också producerats inom projektet med syfte att ge en lättöverskådlig bild över indikatorerna och vad de kan användas till.
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20.
  • Fang, Keyan, et al. (författare)
  • Time-varying relationships among oceanic and atmospheric modes: A turning point at around 1940
  • 2018
  • Ingår i: Quaternary International. - : Elsevier BV. - 1040-6182. ; 487:SI, s. 12-25
  • Tidskriftsartikel (refereegranskat)abstract
    • © 2017 Elsevier Ltd and INQUA. Oceanic and atmospheric modes play a key role in modulating climate variations, particularly on interannual and interdecadal scales, causing an indirect response of regional climate to external forcings. This study comprehensively investigated the time-varying linkages among dominant oceanic and atmospheric modes of the Pacific and Atlantic areas on different timescales using the scale space multiresolution correlation analysis. For the Pacific Ocean, the Interdecadal Pacific Oscillation (IPO) shows closer matches with the El Niño-Southern Oscillation (ENSO) than with the Pacific Decadal Oscillation (PDO). This indicates that the ENSO dominates climate variability of the whole Pacific Ocean not only on interannual but also on interdecadal scales. Interdecadal variations of the IPO appear to be more closely linked to southern Pacific Ocean climate before ∼1940, but become more closely linked to northern Pacific Ocean after ∼1940. The shifts on interdecadal connections among northern, tropical and southern parts of the Pacific Oceans seems to be related to the phase shifts of the IPO/PDO, which may contribute to the cooling trend from 1940s to 1970s. For the Atlantic Ocean, the Atlantic Multi-decadal Oscillation (AMO) is closely linked to the North Atlantic Oscillation (NAO) on the interdecadal scale before ∼1940.
  •  
21.
  • Farm, Maria, et al. (författare)
  • Diagnostic Accuracy in Acute Venous Thromboembolism: Comparing D-Dimer, Thrombin Generation, Overall Hemostatic Potential, and Fibrin Monomers
  • 2020
  • Ingår i: TH open : companion journal to thrombosis and haemostasis. - : Thieme. - 2512-9465. ; 4:3, s. e178-e188
  • Tidskriftsartikel (refereegranskat)abstract
    • Introduction For acute venous thromboembolism (VTE), a biomarker with higher specificity than D-dimer would be of great clinical use. Thrombin generation and overall hemostatic potential (OHP) reflect the hemostatic balance by globally assessing multiple coagulation factors and inhibitors. These tests discriminate between healthy controls and patients with a prothrombotic tendency but have yet to be established as clinical biomarkers of VTE. Objective This study compares endogenous thrombin potential (ETP) and OHP to D-dimer and fibrin monomers (FM) in outpatients with suspected VTE. Methods A cross-sectional diagnostic study where 954 patients with suspected pulmonary embolism or deep venous thrombosis were recruited consecutively from the medical emergency department at Karolinska University Hospital. D-dimer, FM, OHP, and ETP were analyzed in a subpopulation of 60 patients with VTE and 98 matched controls without VTE. VTE was verified either by ultrasonography or computed tomography and clinical data were collected from medical records. Results Compared with healthy controls, both VTE and non-VTE patients displayed prothrombotic profiles in OHP and ETP. D-dimer, FM, ETP area under the curve (AUC), and ETP T lag were significantly different between patients with VTE and non-VTE. The largest receiver-operating characteristic AUCs for discrimination between VTE and non-VTE, were found in D-dimer with 0.94, FM 0.77, and ETP AUC 0.65. No useful cutoff could be identified for the ETP or the OHP assay. Conclusion Compared with D-dimer, neither ETP nor OHP were clinically viable biomarkers of acute venous thrombosis. The data indicated that a large portion of the emergency patients with suspected VTE were in a prothrombotic state.
  •  
22.
  • Fredriksson, Teodor, 1992, et al. (författare)
  • An empirical evaluation of algorithms for data labeling
  • 2021
  • Ingår i: Proceedings - 2021 IEEE 45th Annual Computers, Software, and Applications Conference, COMPSAC 2021. - : IEEE. ; , s. 201-209
  • Konferensbidrag (refereegranskat)abstract
    • The lack of labeled data is a major problem in both research and industrial settings since obtaining labels is often an expensive and time-consuming activity. In the past years, several machine learning algorithms were developed to assist and perform automated labeling in partially labeled datasets. While many of these algorithms are available in open-source packages, there is a lack of research that investigates how these algorithms compare to each other for different types of datasets and with different percentages of available labels. To address this problem, this paper empirically evaluates and compares seven algorithms for automated labeling in terms of their accuracy. We investigate how these algorithms perform in twelve different and well-known datasets with three different types of data, images, texts, and numerical values. We evaluate these algorithms under two different experimental conditions, with 10% and 50% labels of available labels in the dataset. Each algorithm, in each dataset for each experimental condition, is evaluated independently ten times with different random seeds. The results are analyzed and the algorithms are compared utilizing a Bayesian Bradley-Terry model. The results indicate that the active learning algorithms using the query strategies uncertainty sampling, QBC and random sampling are always the best algorithms. However, this comes with the expense of increased manual labeling effort. These results help machine learning practitioners in choosing optimal machine learning algorithms to label their data.
  •  
23.
  • Fredriksson, Teodor, 1992, et al. (författare)
  • Assessing the Suitability of Semi-Supervised Learning Datasets using Item Response Theory
  • 2021
  • Ingår i: Proceedings - 2021 47th Euromicro Conference on Software Engineering and Advanced Applications, SEAA 2021. - : IEEE. - 9781665427050 ; , s. 326-333
  • Konferensbidrag (refereegranskat)abstract
    • In practice, supervised learning algorithms require fully labeled datasets to achieve the high accuracy demanded by current modern applications. However, in industrial settings supervised learning algorithms can perform poorly because of few labeled instances. Semi-supervised learning (SSL) is an automatic labeling approach that utilizes complete labels to infer missing labels in partially complete datasets. The high number of available SSL algorithms and the lack of systematic comparison between them leaves practitioners without guidelines to select the appropriate one for their application. Moreover, each SSL algorithm is often validated and evaluated in a small number of common datasets. However, there is no research that examines what datasets are suitable for comparing different SSL algorihtms. The purpose of this paper is to empirically evaluate the suitability of the datasets commonly used to evaluate and compare different SSL algorithms. We performed a simulation study using twelve datasets of three different datatypes (numerical, text, image) on thirteen different SSL algorithms. The contributions of this paper are two-fold. First, we propose the use of Bayesian congeneric item response theory model to assess the suitability of commonly used datasets. Second, we compare the different SSL algorithms using these datasets. The results show that with except of three datasets, the others have very low discrimination factors and are easily solved by the current algorithms. Additionally, the SSL algorithms have overlapping 90% credible intervals, indicating uncertainty in the difference between the accuracy of these SSL models. The paper concludes suggesting that researchers and practitioners should better consider the choice of datasets used for comparing SSL algorithms.
  •  
24.
  • Fredriksson, Teodor, 1992, et al. (författare)
  • Data Labeling: An Empirical Investigation into Industrial Challenges and Mitigation Strategies
  • 2020
  • Ingår i: Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics). - Cham : Springer International Publishing. - 1611-3349 .- 0302-9743. ; 12562 LNCS, s. 202-216, s. 202-216
  • Konferensbidrag (refereegranskat)abstract
    • Labeling is a cornerstone of supervised machine learning. However, in industrial applications, data is often not labeled, which complicates using this data for machine learning. Although there are well-established labeling techniques such as crowdsourcing, active learning, and semi-supervised learning, these still do not provide accurate and reliable labels for every machine learning use case in the industry. In this context, the industry still relies heavily on manually annotating and labeling their data. This study investigates the challenges that companies experience when annotating and labeling their data. We performed a case study using a semi-structured interview with data scientists at two companies to explore their problems when labeling and annotating their data. This paper provides two contributions. We identify industry challenges in the labeling process, and then we propose mitigation strategies for these challenges.
  •  
25.
  • Fredriksson, Teodor, et al. (författare)
  • Machine Learning Algorithms for Labeling : Where and How They are Used?
  • 2022
  • Ingår i: 2022 IEEE International Systems Conference (SysCon). - : IEEE. - 9781665439923 - 9781665439930
  • Konferensbidrag (refereegranskat)abstract
    • With the increased availability of new and better computer processing units (CPUs) as well as graphical processing units (GPUs), the interest in statistical learning and deep learning algorithms for classification tasks has grown exponentially. These classification algorithms often require the presence of fully labeled instances during the training period for maximum classification accuracy. However, in industrial applications, data is commonly not fully labeled, which both reduces the prediction accuracy of the learning algorithms as well as increases the project cost to label the missing instances. The purpose of this paper is to survey the current state-of-the-art literature on machine learning algorithms that are used for assisted or automatic labeling and to understand where these are used. We performed a systematic mapping study and identified 52 primary studies relevant to our research. This paper provides three main contributions. First, we identify the existing machine learning algorithms for labeling and we present a taxonomy of these algorithms. Second, we identify the datasets that are used to evaluate the algorithms and we provide a mapping of the datasets based on the type of data and the application area. Third, we provide a process to support people in industry to optimally label their dataset. The results presented in this paper can be used by both researchers and practitioners aiming to improve the missing labels with the aid of machine algorithms or to select appropriate datasets to compare new state-of-the art algorithms in their respective application area.
  •  
26.
  • Fredriksson, Teodor, 1992, et al. (författare)
  • Machine Learning Algorithms for Labeling: Where and How They are Used?
  • 2022
  • Ingår i: SysCon 2022 - 16th Annual IEEE International Systems Conference, Proceedings.
  • Konferensbidrag (refereegranskat)abstract
    • With the increased availability of new and better computer processing units (CPUs) as well as graphical processing units (GPUs), the interest in statistical learning and deep learning algorithms for classification tasks has grown exponentially. These classification algorithms often require the presence of fully labeled instances during the training period for maximum classification accuracy. However, in industrial applications, data is commonly not fully labeled, which both reduces the prediction accuracy of the learning algorithms as well as increases the project cost to label the missing instances. The purpose of this paper is to survey the current state-of-the-art literature on machine learning algorithms that are used for assisted or automatic labeling and to understand where these are used. We performed a systematic mapping study and identified 52 primary studies relevant to our research. This paper provides three main contributions. First, we identify the existing machine learning algorithms for labeling and we present a taxonomy of these algorithms. Second, we identify the datasets that are used to evaluate the algorithms and we provide a mapping of the datasets based on the type of data and the application area. Third, we provide a process to support people in industry to optimally label their dataset. The results presented in this paper can be used by both researchers and practitioners aiming to improve the missing labels with the aid of machine algorithms or to select appropriate datasets to compare new state-of-the art algorithms in their respective application area.
  •  
27.
  •  
28.
  • Grönvall, Ylva (författare)
  • The Purchase of Sex : Perceptions, Experiences, and Social Work Practices
  • 2024
  • Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
    • The aim of this study is to explore sex buyers’ perceptions and experiences of purchasing sex, and to study how the purchase of sex is constructed as a social problem in Swedish social work practice. The empirical material consists of interviews with 30 men with experiences of purchasing sex and with ten social workers conducting counselling or outreach work with men who purchase sex. The dissertation is a compilation thesis that consists of four papers, that have been published in international peer-review journals. The first paper focuses on how men who buy sex as one-time visitors navigate between commercialization and intimacy in a national context criminalizing their actions. The paper explores the construction of meaning and intimacy in commercial relationships for Swedish men buying sex, and how these men describe relational practices and strategies used when they purchased sex. The second paper explores the construction of intimacy among men engaged in longterm transactional relationships with women. The paper focuses on the meaning of transactions for intimacy in long-term paid sexual relationships. The third paper explores how men who purchase sex in a context in which their activities are criminalized understand and perceive risk. The paper focuses on individual assessments of risk in relation to experiences of crime, exploitation, and stigma. The fourth paper aims at exploring social workers’ understanding of the purchase of sex as a social problem. The study focuses on social workers’ approaches to the purchase of sex in relation to values, professional practices, and political goals, and how they navigate these aspects in their encounters with individuals who purchase sex. The four papers show how individual experiences are understood, navigated, and conceptualized in relation to social interaction and social norms. The participants in both sub-studies navigate between their own experiences and perceptions, moral values, and social norms in regard to the purchase of sex in Sweden. Both the sex buyers and the social workers conceptualize and make sense of the purchase of sex based on their individual experiences as sex buyers or as social workers meeting sex buyers, but they also relate to normative ideas about the purchase of sex and about ‘sex buyers’.
  •  
29.
  • Hall, B. E. S., et al. (författare)
  • Annual variations in the Martian bow shock location as observed by the Mars Express mission
  • 2016
  • Ingår i: Journal of Geophysical Research - Space Physics. - 2169-9380 .- 2169-9402. ; 121:11, s. 11474-11494
  • Tidskriftsartikel (refereegranskat)abstract
    • The Martian bow shock distance has previously been shown to be anticorrelated with solar wind dynamic pressure but correlated with solar extreme ultraviolet (EUV) irradiance. Since both of these solar parameters reduce with the square of the distance from the Sun, and Mars' orbit about the Sun increases by similar to 0.3 AU from perihelion to aphelion, it is not clear how the bow shock location will respond to variations in these solar parameters, if at all, throughout its orbit. In order to characterize such a response, we use more than 5 Martian years of Mars Express Analyser of Space Plasma and EneRgetic Atoms (ASPERA-3) Electron Spectrometer measurements to automatically identify 11,861 bow shock crossings. We have discovered that the bow shock distance as a function of solar longitude has a minimum of 2.39 R-M around aphelion and proceeds to a maximum of 2.65 R-M around perihelion, presenting an overall variation of similar to 11% throughout the Martian orbit. We have verified previous findings that the bow shock in southern hemisphere is on average located farther away from Mars than in the northern hemisphere. However, this hemispherical asymmetry is small (total distance variation of similar to 2.4%), and the same annual variations occur irrespective of the hemisphere. We have identified that the bow shock location is more sensitive to variations in the solar EUV irradiance than to solar wind dynamic pressure variations. We have proposed possible interaction mechanisms between the solar EUV flux and Martian plasma environment that could explain this annual variation in bow shock location.
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30.
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31.
  • Holmström, Jonny, et al. (författare)
  • Stalled data flows in digital innovation networks: Underlying mechanisms and the role of related variety
  • 2024
  • Ingår i: Industrial Marketing Management. - : Elsevier. - 0019-8501 .- 1873-2062. ; 121, s. 16-26
  • Tidskriftsartikel (refereegranskat)abstract
    • Data flows across organizational boundaries are vital for creating and capturing value from data-intensive digital technologies, such as Artificial Intelligence. To achieve this, organizations increasingly engage in digital innovation networks, i.e., constellations of relations among dispersed, loosely coupled actors, who seek to collaborate for combining heterogeneously distributed domain expertise to train and leverage emerging digital technologies that learn from data. Yet, data flows remain stalled within digital innovation networks, and organizations fail to achieve sought-after benefits from data-intensive digital technologies. To date, research has paid limited attention to what contributes to stalled data flows and what strategies are required to facilitate seamless data flows. Our in-depth qualitative study of a digital innovation network within the Swedish forestry identified four key mechanisms underlying stalled data flows and hampering firms in leveraging value from data-intensive digital technologies and revealed the key role of brokerage functions in digital innovation networks for establishing what we call related variety.
  •  
32.
  • Holmström, Tim H., et al. (författare)
  • c-Jun supports ribosomal RNA processing and nucleolar localization of RNA helicase DDX21
  • 2008
  • Ingår i: Journal of Biological Chemistry. - 0021-9258 .- 1083-351X. ; 283:11, s. 7046-7053
  • Tidskriftsartikel (refereegranskat)abstract
    • The molecular mechanisms by which the AP-1 transcription factor c-Jun exerts its biological functions are not clearly understood. In addition to its well established role in transcriptional regulation of gene expression, several reports have suggested that c-Jun may also regulate cell behavior by non-transcriptional mechanisms. Here, we report that small interfering RNA-mediated depletion of c-Jun from mammalian cells results in inhibition of 28 S and 18 S rRNA accumulation. Moreover, we show that c-Jun depletion results in partial translocation of RNA helicase DDX21, implicated in rRNA processing, from the nucleolus to the nucleoplasm. We demonstrate that DDX21 translocation is rescued by exogenous c-Jun expression and that c-Jun depletion inhibits rRNA binding of DDX21. Furthermore, the direct interaction between c-Jun and DDX21 regulates nucleolar localization of DDX21. These results demonstrate that in addition to its transcriptional effects, c-Jun regulates rRNA processing and nucleolar compartmentalization of the rRNA processing protein DDX21. Thus, our results demonstrate a nucleolar mechanism through which c-Jun can regulate cell behavior. Moreover, these results suggest that the phenotypes observed previously in c-Jun-depleted mouse models and cell lines could be partly due to the effects of c-Jun on rRNA processing.
  •  
33.
  • Hou, Ziyong, et al. (författare)
  • Effect of carbon content on the Curie temperature of WC-NiFe cemented carbides
  • 2019
  • Ingår i: International journal of refractory metals & hard materials. - : Elsevier. - 0263-4368. ; 78, s. 27-31
  • Tidskriftsartikel (refereegranskat)abstract
    • We have investigated the effect of the carbon content on the Curie temperature of a cemented carbide composite material with a Ni-Fe alloy as the binder phase and WC as the hard phase. In the carbon concentration range from 5.72 to 5.83 wt% carbon, which covers the interval where WC coexists with fcc Ni-Fe without other phases (the ‘carbon window’), the Curie temperature rises from 200 to 527 °C. This result indicates the possibility to use the Curie temperature to determine the carbon balance in the system. With thermodynamic calculations and kinetic simulations we can quantitatively establish the correlation between the carbon and tungsten content of the binder phase and the Curie temperature. This strong compositional effect on the Curie temperature is quantitatively very different from the conventional Co-based cemented carbides, with Curie temperatures of about 950–1050 °C.
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34.
  • Hou, Ziyong, 1986-, et al. (författare)
  • Evaluating magnetic properties of composites from model alloys – Application to alternative binder cemented carbides
  • 2019
  • Ingår i: Scripta Materialia. - : Acta Materialia Inc. - 1359-6462 .- 1872-8456. ; 168, s. 96-99
  • Tidskriftsartikel (refereegranskat)abstract
    • The magnetic properties of 85Ni-15Fe model alloys containing Co, W and C have been studied with the intent to isolate the influence of alloy chemistry on quality control measurements of alternative binder cemented carbides. The results show a strong influence of dissolved W on the Curie temperature and the saturation magnetization. The amount of dissolved C, and the presence of WC precipitates, on the other hand, is shown to have negligible effect. Furthermore, the magnetic coercivity is indicated to be entirely dominated by the microstructural features and quite insensitive to composition.
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35.
  • Issa Mattos, David, 1990, et al. (författare)
  • ACE: Easy deployment of field optimization experiments
  • 2019
  • Ingår i: Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics). - Cham : Springer International Publishing. - 1611-3349 .- 0302-9743. ; 11681 LNCS, s. 264-279, s. 264-279
  • Konferensbidrag (refereegranskat)abstract
    • Optimization of software parameters is a recurring activity in the life-cycle of many software products, from prototypes and simulations, test beds and hardware-in-the-loop scenarios, field calibrations to the evolution of continuous deployment cycles. To perform this activity, software companies require a combination of software developers and optimization experts with domain specific knowledge. Moreover, in each of life-cycle steps, companies utilize a plethora of different tools, tailored for specific domains or development stages. To most companies, this scenario leads to an excessive cost in the optimization of smaller features or in cases where it is not clear what the returned value will be. In this work we present a new optimization system based on field experiments, that is aimed to facilitate the adoption of optimization in all stages of development. We provide two main contributions. First, we present the architecture of a new optimization system that allows existing software systems to perform optimization procedures in different domains and in different development stages. This optimization system utilizes domain-agnostic interfaces to allow existing systems to perform optimization procedures with minimal invasiveness and optimization expertise. Second, we provide an overview of the deployments, discuss the advantages and limitations and evaluate the optimization system in three empirical scenarios: (1) offline optimization with simulations; (2) optimization of a communication system in a test bed in collaboration with Ericsson; (3) live optimization of a mobile application in collaboration with Sony Mobile. We aim to provide practitioners with a single optimization tool that can leverage their optimization activities from offline to live systems, with minimal invasiveness and optimization expertise.
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36.
  • Issa Mattos, David, 1990, et al. (författare)
  • An activity and metric model for online controlled experiments
  • 2018
  • Ingår i: Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics). - Cham : Springer International Publishing. - 1611-3349 .- 0302-9743. ; 11271 LNCS, s. 182-198, s. 182-198
  • Konferensbidrag (refereegranskat)abstract
    • Accurate prioritization of efforts in product and services development is critical to the success of every company. Online controlled experiments, also known as A/B tests, enable software companies to establish causal relationships between changes in their systems and the movements in the metrics. By experimenting, product development can be directed towards identifying and delivering value. Previous research stresses the need for data-driven development and experimentation. However, the level of granularity in which existing models explain the experimentation process is neither sufficient, in terms of details, nor scalable, in terms of how to increase number and run different types of experiments, in an online setting. Based on a case study of multiple products running online controlled experiments at Microsoft, we provide an experimentation framework composed of two detailed experimentation models focused on two main aspects; the experimentation activities and the experimentation metrics. This work intends to provide guidelines to companies and practitioners on how to set and organize experimentation activities for running trustworthy online controlled experiments.
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37.
  • Issa Mattos, David, 1990, et al. (författare)
  • Automated optimization of software parameters in a long term evolution radio base station
  • 2019
  • Ingår i: SysCon 2019 - 13th Annual IEEE International Systems Conference, Proceedings. - : Institute of Electrical and Electronics Engineers (IEEE).
  • Konferensbidrag (refereegranskat)abstract
    • Radio network optimization is concerned with the configuration of radio base station parameters in order to achieve the desired level of service quality in addition to many other differentiating technical factors. Mobile network operators have different physical locations, levels of traffic profiles, number of connected devices, and the desired quality of service. All of these conditions make the problem of optimizing the parameters of a radio base station specific to the operator's business goals. The high number of calibration parameters and the complex interaction between them make the system behave as a black-box model for any practical purpose. The computation of relevant operator metrics is often stochastic, and it can take several minutes to compute the effect of changing a single, making it impractical to optimize systems with approaches that require a large number of iterations. Operators want to optimize their already deployed system in online scenarios while minimizing the exposure of the system to a negative set of parameters during the optimization procedure. {This paper presents a novel approach to the optimization of a Long Term Evolution (LTE) radio base station in a large search space with an expensive stochastic objective and a limited regret bounds scenario. We show the feasibility of this approach by implementing it in an industrial testing bed radio base station connected to real User Equipment (UE) in collaboration with Ericsson. Two optimization processes in this experimental setup are executed to show the feasibility of the approach in real-world scenarios.
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38.
  • Issa Mattos, David, 1990, et al. (författare)
  • Automotive A/B testing : Challenges and Lessons Learned from Practice
  • 2020
  • Ingår i: 2020 46th Euromicro Conference on Software Engineering and Advanced Applications (SEAA). - : IEEE. - 9781728195322 - 9781728195339 ; , s. 101-109
  • Konferensbidrag (refereegranskat)abstract
    • Over the past 15 years, A/B testing has been a critical tool for accurate prioritization of development efforts in online and web-facing companies. As automotive companies progress on their digitalization process, A/B testing and other experimentation techniques start to be adopted. However, specific characteristics of the automotive software industry create additional challenges to the successful adoption of A/B testing. Recently, research has been conducted to investigate the challenges and opportunities for experimentation techniques in the automotive and more generally in the embedded systems domain. However, despite the collaboration with industry, previous research was based on either hypothesized or toy scenarios in companies seeking, but not yet running experimentation. Utilizing a case study method, we investigate the challenges of adopting A/B testing in two large-scale automotive companies that are currently running or preparing for their first A/B testing. The contribution of this paper is two-fold. First, we present our main findings in terms of the challenges of real A/B testing iterations in automotive vehicles. Second, we present the current, potential solutions and lessons learned from applying A/B testing in the automotive domain.
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39.
  • Issa Mattos, David, 1990, et al. (författare)
  • Challenges and strategies for undertaking continuous experimentation to embedded systems: Industry and research perspectives
  • 2018
  • Ingår i: Lecture Notes in Business Information Processing. - Cham : Springer International Publishing. - 1865-1356 .- 1865-1348. ; 314, s. 277-292, s. 277-292
  • Konferensbidrag (refereegranskat)abstract
    • Context: Continuous experimentation is frequently used in web-facing companies and it is starting to gain the attention of embedded systems companies. However, embedded systems companies have different challenges and requirements to run experiments in their systems. Objective: This paper explores the challenges during the adoption of continuous experimentation in embedded systems from both industry practice and academic research. It presents strategies, guidelines, and solutions to overcome each of the identified challenges. Method: This research was conducted in two parts. The first part is a literature review with the aim to analyze the challenges in adopting continuous experimentation from the research perspective. The second part is a multiple case study based on interviews and workshop sessions with five companies to understand the challenges from the industry perspective and how they are working to overcome them. Results: This study found a set of twelve challenges divided into three areas; technical, business, and organizational challenges and strategies grouped into three categories, architecture, data handling and development processes. Conclusions: The set of identified challenges are presented with a set of strategies, guidelines, and solutions. To the knowledge of the authors, this paper is the first to provide an extensive list of challenges and strategies for continuous experimentation in embedded systems. Moreover, this research points out open challenges and the need for new tools and novel solutions for the further development of experimentation in embedded systems.
  •  
40.
  • Issa Mattos, David, 1990, et al. (författare)
  • Experimentation for Business-to-Business Mission-Critical Systems: A Case Study
  • 2020
  • Ingår i: Proceedings - 2020 IEEE/ACM International Conference on Software and System Processes, ICSSP 2020. - New York, NY, USA : ACM. - 9781450375122 ; 26 June 2020, s. 95-104
  • Konferensbidrag (refereegranskat)abstract
    • Continuous experimentation (CE) refers to a group of practices used by software companies to rapidly assess the usage, value and performance of deployed software using data collected from customers and the deployed system. Despite its increasing popularity in the development of web-facing applications, CE has not been discussed in the development process of business-to-business (B2B) mission-critical systems. We investigated in a case study the use of CE practices within several products, teams and areas inside Ericsson. By observing the CE practices of different teams, we were able to identify the key activities in four main areas and inductively derive an experimentation process, the HURRIER process, that addresses the deployment of experiments with customers in the B2B and with mission-critical systems. We illustrate this process with a case study in the development of a large mission-critical functionality in the Long Term Evolution (4G) product. In this case study, the HURRIER process is not only used to validate the value delivered by the solution but to increase the quality and the confidence from both the customers and the R&D organization in the deployed solution. Additionally, we discuss the challenges, opportunities and lessons learned from applying CE and the HURRIER process in B2B mission-critical systems.
  •  
41.
  • Issa Mattos, David, 1990, et al. (författare)
  • Experimentation for business-to-business mission-critical systems: A case study
  • 2022
  • Ingår i: Accelerating Digital Transformation: 10 Years of Software Center. - 9783031108730 ; , s. 351-371
  • Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
    • Continuous experimentation (CE) refers to a group of practices used by software companies to rapidly assess the usage, value and performance of deployed software using data collected from customers and the deployed system. Despite its increasing popularity in the development of web-facing applications, CE has not been discussed in the development process of business-to-business (B2B) mission-critical systems. We investigated in a case study the use of CE practices within several products, teams and areas inside Ericsson. By observing the CE practices of different teams, we were able to identify the key activities in four main areas and inductively derive an experimentation process, the HURRIER process, that addresses the deployment of experiments with customers in the B2B and with mission-critical systems. We illustrate this process with a case study in the development of a large mission-critical functionality in the Long Term Evolution (4G) product. In this case study, the HURRIER process is not only used to validate the value delivered by the solution but to increase the quality and the confidence from both the customers and the R&D organization in the deployed solution. Additionally, we discuss the challenges, opportunities and lessons learned from applying CE and the HURRIER process in B2B mission-critical systems.
  •  
42.
  • Issa Mattos, David, 1990, et al. (författare)
  • Leveraging business transformation with machine learning experiments
  • 2019
  • Ingår i: Lecture Notes in Business Information Processing. - Cham : Springer International Publishing. - 1865-1356 .- 1865-1348. ; 370 LNBIP, s. 183-191
  • Konferensbidrag (refereegranskat)abstract
    • The deployment of production-quality ML solutions, even for simple applications, requires significant software engineering effort. Often, companies do not fully understand the consequences and the business impact of ML-based systems, prior to the development of these systems. To minimize investment risks while evaluating the potential business impact of an ML system, companies can utilize continuous experimentation techniques. Based on action research, we report on the experience of developing and deploying a business-oriented ML-based dynamic pricing system in collaboration with a home shopping e-commerce company using a continuous experimentation (CE) approach. We identified a set of generic challenges in ML development that we present together with tactics and opportunities.
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43.
  • Issa Mattos, David, 1990, et al. (författare)
  • Multi-armed bandits in the wild: Pitfalls and strategies in online experiments
  • 2019
  • Ingår i: Information and Software Technology. - : Elsevier BV. - 0950-5849 .- 1873-6025. ; 113:September, s. 68-81
  • Tidskriftsartikel (refereegranskat)abstract
    • © 2019 Context: Delivering faster value to customers with online experimentation is an emerging practice in industry. Multi-Armed Bandit (MAB) based experiments have the potential to deliver even faster results with a better allocation of resources over traditional A/B experiments. However, the incorrect use of MAB-based experiments can lead to incorrect conclusions that can potentially hurt the company's business. Objective: The objective of this study is to understand the pitfalls and restrictions of using MABs in online experiments, as well as the strategies that are used to overcome them. Method: This research uses a multiple case study method with eleven experts across five software companies and simulations to triangulate the data of some of the identified limitations. Results: This study analyzes some limitations faced by companies using MAB and discusses strategies used to overcome them. The results are summarized into practitioners’ guidelines with criteria to select an appropriated experimental design. Conclusion: MAB algorithms have the potential to deliver even faster results with a better allocation of resources over traditional A/B experiments. However, potential mistakes can occur and hinder the potential benefits of such approach. Together with the provided guidelines, we aim for this paper to be used as reference material for practitioners during the design of an online experiment.
  •  
44.
  • Issa Mattos, David, 1990, et al. (författare)
  • Optimization experiments in the continuous space: The limited growth optimistic optimization algorithm
  • 2018
  • Ingår i: Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics). - Cham : Springer International Publishing. - 1611-3349 .- 0302-9743. ; 11036 LNCS, s. 293-308, s. 293-308
  • Konferensbidrag (refereegranskat)abstract
    • Online controlled experiments are extensively used by web-facing companies to validate and optimize their systems, providing a competitive advantage in their business. As the number of experiments scale, companies aim to invest their experimentation resources in larger feature changes and leave the automated techniques to optimize smaller features. Optimization experiments in the continuous space are encompassed in the many-armed bandits class of problems. Although previous research provides algorithms for solving this class of problems, these algorithms were not implemented in real-world online experimentation problems and do not consider the application constraints, such as time to compute a solution, selection of a best arm and the estimation of the mean-reward function. This work discusses the online experiments in context of the many-armed bandits class of problems and provides three main contributions: (1) an algorithm modification to include online experiments constraints, (2) implementation of this algorithm in an industrial setting in collaboration with Sony Mobile, and (3) statistical evidence that supports the modification of the algorithm for online experiments scenarios. These contributions support the relevance of the LG-HOO algorithm in the context of optimization experiments and show how the algorithm can be used to support continuous optimization of online systems in stochastic scenarios.
  •  
45.
  • Issa Mattos, David, 1990, et al. (författare)
  • Statistical Models for the Analysis of Optimization Algorithms with Benchmark Functions
  • 2021
  • Ingår i: IEEE Transactions on Evolutionary Computation. - : IEEE. - 1089-778X .- 1941-0026. ; 25:6, s. 1163-1177
  • Tidskriftsartikel (refereegranskat)abstract
    • Frequentist statistical methods, such as hypothesis testing, are standard practices in studies that provide benchmark comparisons. Unfortunately, these methods have often been misused, e.g., without testing for their statistical test assumptions or without controlling for familywise errors in multiple group comparisons, among several other problems. Bayesian data analysis (BDA) addresses many of the previously mentioned shortcomings but its use is not widely spread in the analysis of empirical data in the evolutionary computing community. This article provides three main contributions. First, we motivate the need for utilizing BDA and provide an overview of this topic. Second, we discuss the practical aspects of BDA to ensure that our models are valid and the results are transparent. Finally, we provide five statistical models that can be used to answer multiple research questions. The online Appendix provides a step-by-step guide on how to perform the analysis of the models discussed in this article, including the code for the statistical models, the data transformations, and the discussed tables and figures. 
  •  
46.
  • Issa Mattos, David, 1990, et al. (författare)
  • The HURRIER process for experimentation in business-to-business mission-critical systems
  • 2023
  • Ingår i: Journal of Software: Evolution and Process. - : Wiley. - 2047-7481 .- 2047-7473. ; 35:5
  • Tidskriftsartikel (refereegranskat)abstract
    • Continuous experimentation (CE) refers to a set of practices used by software companies to rapidly assess the usage, value, and performance of deployed software using data collected from customers and systems in the field using an experimental methodology. However, despite its increasing popularity in developing web-facing applications, CE has not been studied in the development process of business-to-business (B2B) mission-critical systems. By observing the CE practices of different teams, with a case study methodology inside Ericsson, we were able to identify the different practices and techniques used in B2B mission-critical systems and a description and classification of the four possible types of experiments. We present and analyze each of the four types of experiments with examples in the context of the mission-critical long-term evolution (4G) product. These examples show the general experimentation process followed by the teams and the use of the different CE practices and techniques. Based on these examples and the empirical data, we derived the HURRIER process to deliver high-quality solutions that the customers value. Finally, we discuss the challenges, opportunities, and lessons learned from applying CE and the HURRIER process in B2B mission-critical systems.
  •  
47.
  • Issa Mattos, David, 1990, et al. (författare)
  • Your System Gets Better Every Day You Use It : Towards Automated Continuous Experimentation
  • 2017
  • Ingår i: 2017 43rd Euromicro Conference on Software Engineering and Advanced Applications (SEAA). - : IEEE. ; , s. 256-265
  • Konferensbidrag (refereegranskat)abstract
    • Innovation and optimization in software systems can occur from pre-development to post-deployment stages. Companies are increasingly reporting the use of experiments with customers in their systems in the post-deployment stage. Experiments with customers and users are can lead to a significant learning and return-on-investment. Experiments are used for both validation of manual hypothesis testing and feature optimization, linked to business goals. Automated experimentation refers to having the system controlling and running the experiments, opposed to having the R&D organization in control. Currently, there are no systematic approaches that combine manual hypothesis validation and optimization in automated experiments. This paper presents concepts related to automated experimentation, as controlled experiments, machine learning and software architectures for adaptation. However, this paper focuses on how architectural aspects that can contribute to support automated experimentation. A case study using an autonomous system is used to demonstrate the developed initial architecture framework. The contributions of this paper are threefold. First, it identifies software architecture qualities to support automated experimentation. Second, it develops an initial architecture framework that supports automated experiments and validates the framework with an autonomous mobile robot. Third, it identifies key research challenges that need to be addressed to support further development of automated experimentation.
  •  
48.
  • Krantz, David, et al. (författare)
  • Neoadjuvant Chemotherapy Reinforces Antitumour T cell Response in Urothelial Urinary Bladder Cancer
  • 2018
  • Ingår i: European Urology. - : Elsevier. - 0302-2838 .- 1873-7560. ; 74:6, s. 688-692
  • Tidskriftsartikel (refereegranskat)abstract
    • Evidence indicates that neoadjuvant chemotherapy (NAC) may promote antitumour immune responses by activating T cells. The tumour-draining sentinel node (SN) is a key site to study tumour-specific T cell activation, being the primary immunological barrier against the tumour. In this prospective study, we set out to elucidate the effects of NAC on T cell subsets in the SNs of patients with muscle-invasive urothelial bladder cancer. We found that CD8+ effector T (Teff) cell exhaustion was reduced after NAC treatment, while cytotoxicity was increased. Additionally, in complete responders (CR patients), these cells were functionally committed effectors, as displayed by epigenetic analysis. In CD4+ Teffs, NAC treatment was associated with increased clonal expansion of tumour-specific SN-derived cells, as demonstrated by a specific cell reactivity assay. In contrast, we observed an attenuating effect of NAC on regulatory T cells (Tregs) with a dose-dependent decrease in Treg frequency and reduced effector molecule expression in the remaining Tregs. In addition, multicolour flow cytometry analysis revealed that CR patients had higher Teff to activated Treg ratio, promoting antitumoural T cell activation. These results suggest that NAC reinforces the antitumour immune response by activating the effector arm of the T cell compartment and diminishing the influence of suppressive Tregs.PATIENT SUMMARY: In this report, we analysed the effect of chemotherapy on immune cell subsets of 40 patients with advanced bladder cancer. We found that chemotherapy has a positive effect on immune effector T cells, whereas an opposite, diminishing effect was observed for immune-suppressive regulatory T cells. We conclude that chemotherapy reinforces the antitumour immune response in bladder cancer patients.
  •  
49.
  • Linder, David, et al. (författare)
  • A comparative study of microstructure and magnetic properties of a Ni–Fe cemented carbide : Influence of carbon content
  • 2019
  • Ingår i: International journal of refractory metals & hard materials. - : Elsevier Ltd. - 0263-4368. ; 80, s. 181-187
  • Tidskriftsartikel (refereegranskat)abstract
    • Due to the renewed interest in alternative binders for cemented carbides it is important to understand how the binder composition influences not only mechanical properties but also the microstructure and related measurements for quality control. Microstructure and chemical composition of WC-Co is often evaluated by magnetic measurements. However, when the binder composition deviates significantly from conventional Co-based binders it should not be assumed that the standard measurements can be used to directly evaluate the same parameters. In this paper we investigate the influence of relative C-content on the microstructure and magnetic properties of an alternative binder cemented carbide. It is shown that the saturation magnetization is related to the relative C-content and the magnetic coercivity is related to the microstructure, more specifically to the binder phase distribution, but could not be directly linked to the carbide grain size in the same manner as for standard WC-Co. Furthermore, a direct correlation between Curie temperature and saturation magnetization is observed for this system which means that the Curie temperature potentially could be used for calibration of empirical relations or as a method to accurately determine the binder volume fraction.
  •  
50.
  • Linder, David, et al. (författare)
  • High entropy alloy binders in gradient sintered hardmetal
  • 2018
  • Ingår i: International journal of refractory metals & hard materials. - : Elsevier. - 0263-4368. ; 71, s. 217-220
  • Tidskriftsartikel (refereegranskat)abstract
    • High Entropy Alloys (HEAs) are a new group of multicomponent alloys showing great potential as bulk alloys in many fields, and their high temperature strength is especially of interest. In previous work (D. Linder, M.Sc Thesis "High Entropy Alloys - Alternative binders in cemented carbides", Linkoping University, Sweden (2015)) we have shown the possibility to produce cemented carbides with HEA-binders using standard powder metallurgical methods. The present work investigates the possibility to produce gradient sintered cemented carbides using HEA-binders. The materials are analyzed with regards to gradient depth, phases formed, phase composition and carbide grain size. The gradient formation is investigated with respect to C-content and sintering process and the results are showing the possibility to form industrially relevant gradient depths using standard methods. These results open up a whole new range of possible applications for these materials and show the potential for future design of a wide composition range of alternative binders.
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