35 research outputs found

    Use of Data-Driven Approaches for Defect Classification in Stator Winding Insulation

    Get PDF
    Partial discharges (PD) in the high voltage insulation systems are both a symptom and cause of terminal and impending failures. The use of data-driven methods based on PD measurements will enable predictive strategies to replace traditional maintenance strategies. This paper employs machine learningbased classification models to identify and characterize PD signals originating from lab-made artificial defects in epoxy-mica material samples. Three different PD sources were studied: surface discharges in air, corona discharges, and discharges caused by internal cavities/delaminations. To generate high-quality datasets for the training, validation, and testing of classification models, Phase-Resolved PD (PRPD) data for each test object was obtained at room temperature under 50 Hz AC excitation at 10 % above the PD inception voltage (PDIV) of each sample. Relevant statistical and deterministic features were extracted for each observation and were labeled based on the defect type (supervised learning). Finally, the trained and validated ML models were used to identify PD sources in the service-aged stator winding insulation. Support vector machines (SVM), ensemble, and k-nearest neighbor (kNN) algorithms achieved significantly high accuracy (≥ 95 %) of defect identification.publishedVersio

    Motivational counselling and SMS-reminders for reduction of daily sitting time in patients with rheumatoid arthritis:a descriptive randomised controlled feasibility study

    Get PDF
    BACKGROUND: Patients with rheumatoid arthritis (RA) spend a high proportion of their waking time in sedentary behaviour (SB) and have an increased risk of cardiovascular disease. Reduction of SB and increase in light intensity physical activity has been suggested as a means of improvement of health in patients with mobility problems. Short-term intervention studies have demonstrated that SB can be reduced by behavioural interventions in sedentary populations. To evaluate descriptively the feasibility of recruitment, randomisation, outcome assessments, retention and the acceptability of an individually tailored, theory-based behavioural intervention targeting reduction in daily sitting time in patients with RA. METHODS: A randomised, controlled trial with two parallel groups. RA patients >18 years of age and Health Assessment Questionnaire (HAQ) score < 2.5 were consecutively invited and screened for daily leisure time sitting > 4 h. The 16-week intervention included 1) three individual motivational counselling sessions and 2) individual text message reminders aimed at reducing daily sitting time. The control group was encouraged to maintain their usual lifestyles. Outcomes were assessed at baseline and after the 16 week intervention. Daily sitting time was measured using an ActivPAL3(TM) activity monitor. The study was not powered to show superiority; rather the objective was to focus on acceptability among patients and clinical health professionals. RESULTS: In total, 107 patients were invited and screened before 20 met eligibility criteria and consented; reasons for declining study participation were mostly flares, lack of time and co-morbidities. One patient from the control group dropped out before end of intervention (due to a RA flare). Intervention participants completed all counselling sessions. All procedures regarding implementation of the trial protocol were feasible. The daily sitting time was reduced on average by 0.30 h in the intervention group unlike the control group that tended to increase it by 0.15 h after 16 weeks. CONCLUSIONS: This study shows that an individually tailored behavioural intervention targeting reduction of SB was feasible and acceptable to patients with RA. TRIAL REGISTRATION: The Danish Data Protection Agency (ref.nb. 711-1-08 - 20 March 2011), the Ethics Committee of the Capital Region of Denmark (ref.nb. H-2-2012-112- 17 October 2012), clinicaltrials.gov (NCT01969604 - October 17 2013, retrospectively registered)

    Adaptation strategies of horses with induced forelimb lameness walking on a treadmill

    Get PDF
    Background There is a paucity of research describing the gait pattern of lame horses at the walk. Objectives To describe the changes in motion pattern and vertical ground reaction forces (GRFz) in horses with induced forelimb lameness at the walk and compare those changes with the changes observed at the trot. Study design Experimental study. Methods In 10 clinically sound Warmblood horses, moderate forelimb lameness was induced using a sole pressure model followed by trot and walk on a treadmill. Kinematic data were collected using 3D optical motion capture (OMC), and GRFz by an instrumented treadmill. Mixed models were used to compare sound baseline versus forelimb lameness (significance was set atP < .05). Results Lameness induction significantly reduced peak GRFz on the second force peak, and vertical impulse in the lame limb. Stride and stance duration in all limbs were reduced. Lameness significantly affected the vertical movement symmetry of the head and withers. Maximum limb retraction angle, fetlock extension and protraction speed were reduced in the lame limb. Body centre of mass (COM) translation was reduced in the side-to-side direction and increased in the vertical and fore-aft directions. Several compensatory kinetic and kinematic changes were observed in the nonlame limbs. The observed changes in both kinetics and kinematics were generally smaller at walk with fewer variables being affected, compared to the trot. Main limitations Only one degree and type of orthopaedic pain (sole pressure) was studied. Conclusions Compensatory strategies of forelimb lameness at the walk include alteration of several kinetic and kinematic parameters and have some specific patterns and inter-individual differences that are not seen at the trot. However, much like at the trot, head movement and forelimb vertical force symmetry seem to be the most useful parameters to detect forelimb lameness at walk

    EU-wide exposure data of 11 chemical substance groups from the HBM4EU Aligned Studies (2014–2021)

    Get PDF
    Funding Information: The authors would like to thank everybody who contributed to the HBM4EU Aligned Studies: the participating children, teenagers, adults and their families, the fieldworkers that collected the samples and database managers that made the information available to HBM4EU, the HBM4EU project partners, especially those from WP7 for developing all materials supporting the fieldwork, WP9 for organizing the QA/QC scheme under HBM4EU and all laboratories who performed the analytical measurements. We would like to acknowledge Sun Kyoung Jung from the National Institute of Environmental Research of South-Korea for providing the KoNEHS Cycle III results (crt adjusted). HBM4EU is co-financed under Horizon 2020 (grant agreement No 733032). The authors thank all principal investigators of the contributing studies for their participation and contribution to the HBM4EU Aligned Studies and the national program owners for their financial support. Further details on funding for all the participating studies can be found in the Supplemental Material, Table S12.As one of the core elements of the European Human Biomonitoring Initiative (HBM4EU) a human biomonitoring (HBM) survey was conducted in 23 countries to generate EU-wide comparable HBM data. This survey has built on existing HBM capacity in Europe by aligning national or regional HBM studies, referred to as the HBM4EU Aligned Studies. The HBM4EU Aligned Studies included a total of 10,795 participants of three age groups: (i) 3,576 children aged 6–12 years, (ii) 3,117 teenagers aged 12–18 years and (iii) 4,102 young adults aged 20–39 years. The participants were recruited between 2014 and 2021 in 11–12 countries per age group, geographically distributed across Europe. Depending on the age group, internal exposure to phthalates and the substitute DINCH, halogenated and organophosphorus flame retardants, per- and polyfluoroalkyl substances (PFASs), cadmium, bisphenols, polycyclic aromatic hydrocarbons (PAHs), arsenic species, acrylamide, mycotoxins (deoxynivalenol (total DON)), benzophenones and selected pesticides was assessed by measuring substance specific biomarkers subjected to stringent quality control programs for chemical analysis. For substance groups analyzed in different age groups higher average exposure levels were observed in the youngest age group, i.e., phthalates/DINCH in children versus teenagers, acrylamide and pesticides in children versus adults, benzophenones in teenagers versus adults. Many biomarkers in teenagers and adults varied significantly according to educational attainment, with higher exposure levels of bisphenols, phthalates, benzophenones, PAHs and acrylamide in participants (from households) with lower educational attainment, while teenagers from households with higher educational attainment have higher exposure levels for PFASs and arsenic. In children, a social gradient was only observed for the non-specific pyrethroid metabolite 3-PBA and di-isodecyl phthalate (DiDP), with higher levels in children from households with higher educational attainment. Geographical variations were seen for all exposure biomarkers. For 15 biomarkers, the available health-based HBM guidance values were exceeded with highest exceedance rates for toxicologically relevant arsenic in teenagers (40%), 3-PBA in children (36%), and between 11 and 14% for total DON, Σ (PFOA + PFNA + PFHxS + PFOS), bisphenol S and cadmium. The infrastructure and harmonized approach succeeded in obtaining comparable European wide internal exposure data for a prioritized set of 11 chemical groups. These data serve as a reference for comparison at the global level, provide a baseline to compare the efficacy of the European Commission's chemical strategy for sustainability and will give leverage to national policy makers for the implementation of targeted measures.publishersversionpublishe

    Harmonized human biomonitoring in European children, teenagers and adults: EU-wide exposure data of 11 chemical substance groups from the HBM4EU Aligned Studies (2014–2021)

    Get PDF
    HBM4EU is co-financed under Horizon 2020 (grant agreement No 733032).As one of the core elements of the European Human Biomonitoring Initiative (HBM4EU) a human biomonitoring (HBM) survey was conducted in 23 countries to generate EU-wide comparable HBM data. This survey has built on existing HBM capacity in Europe by aligning national or regional HBM studies, referred to as the HBM4EU Aligned Studies. The HBM4EU Aligned Studies included a total of 10,795 participants from three age groups: (i) 3,576 children aged 6-12 years, (ii) 3,117 teenagers aged 12-18 years, and (iii) 4,102 young adults aged 20-39 years. The participants were recruited between 2014 and 2021 in 11-12 countries per age group, geographically distributed across Europe. Depending on the age group, internal exposure to phthalates and the substitute DINCH, halogenated and organophosphorus flame retardants, per- and polyfluoroalkyl substances (PFASs), cadmium, bisphenols, polycyclic aromatic hydrocarbons (PAHs), arsenic species, acrylamide, mycotoxins (deoxynivalenol (total DON)), benzophenones and selected pesticides was assessed by measuring substance specific biomarkers subjected to stringent quality control programs for chemical analysis. For substance groups analyzed in different age groups higher average exposure levels were observed in the youngest age group, i.e., phthalates/DINCH in children versus teenagers, acrylamide and pesticides in children versus adults, and benzophenones in teenagers versus adults. Many biomarkers in teenagers and adults varied significantly according to educational attainment, with higher exposure levels of bisphenols, phthalates, benzophenones, PAHs, and acrylamide in participants (from households) with lower educational attainment, while teenagers from households with higher educational attainment have higher exposure levels for PFASs and arsenic. In children, a social gradient was only observed for the non-specific pyrethroid metabolite 3-PBA and di-isodecyl phthalate (DiDP), with higher levels in children from households with higher educational attainment. Geographical variations were seen for all exposure biomarkers. For 15 biomarkers, the available health-based HBM guidance values were exceeded with the highest exceedance rates for toxicologically relevant arsenic in teenagers (40%), 3-PBA in children (36%), and between 11 and 14% for total DON, Σ (PFOA + PFNA + PFHxS + PFOS), bisphenol S and cadmium. The infrastructure and harmonized approach succeeded in obtaining comparable European-wide internal exposure data for a prioritized set of 11 chemical groups. These data serve as a reference for comparison at the global level, provide a baseline to compare the efficacy of the European Commission's chemical strategy for sustainability, and will give leverage to national policymakers for the implementation of targeted measures.info:eu-repo/semantics/publishedVersio
    corecore