150 research outputs found

    Form removal aspects on the waviness parameters for steel sheet in automotive applications : fourier filtering versus polynomial regression

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    Premium car makers attach great importance to the visual appearance of the painted car skin as an indication of product quality. The “orange peel” phenomenon constitutes a major problem here. It is not only depending on the paint’s chemical composition and application method, but also on possible waviness components in the sheet substrate. Therefore one is searching hard for a valuable waviness parameter to quantify the substrate’s fitness for purpose. A technically emerging problem is how to remove the form from the measured signal, which is indeed not significant to the orange peel phenomenon. This paper will compare two commonly used approaches: i.e. Fourier filtering versus polynomial regression and will reveal and quantify some common aspects in terms of wavelengths

    Valuing Healthcare Goods and Services: A Systematic Review and Meta-Analysis on the WTA-WTP Disparity

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    Objective: The objective of this systematic review was to review the available evidence on the disparity between willingness to accept (WTA) and willingness to pay (WTP) for healthcare goods and services. Methods: A tiered approach consisting of (1) a systematic review, (2) an aggregate data meta-analysis, and (3) an individual participant data meta-analysis was used. MEDLINE, EMBASE, Scopus, Scisearch, and Econlit were searched for articles reporting both WTA and WTP for healthcare goods and services. Individual participant data were requested from the authors of the included studies. Results: Thirteen papers, reporting WTA and WTP from 19 experiments/subgroups, were included in the review. The WTA/WTP ratios reported in these papers, varied from 0.60 to 4.01, with means of 1.73 (median 1.31) for 15 estimates of the mean and 1.58 (median 1.00) for nine estimates of the median. Individual data obtained from six papers, covering 71.2% of the subjects included in the review, yielded an unadjusted WTA/WTP ratio of 1.86 (95% confidence interval 1.52–2.28) and a WTA/WTP ratio adjusted for age, sex, and income of 1.70 (95% confidence interval 1.42–2.02). Income category and age had a statistically significant effect on the WTA/WTP ratio. The approach to handling zero WTA and WTP values has a considerable impact on the WTA/WTP ratio found. Conclusions and Implications: The results of this study imply that losses in healthcare goods and services are valued differently from gains (ratio > 1), but that the degree of disparity found depends on the method used to obtain the WTA/WTP ratio, including the approach to zero responses. Irrespective of the method used, the ratios found in our meta-analysis are smaller than the ratios found in previous meta-analyses

    Effectiveness of analgesic ear drops as add-on treatment to oral analgesics in children with acute otitis media: study protocol of the OPTIMA pragmatic randomised controlled trial

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    INTRODUCTION: Ear pain is the most prominent symptom of childhood acute otitis media (AOM). To control the pain and reduce reliance on antibiotics, evidence of effectiveness for alternative interventions is urgently needed. This trial aims to investigate whether analgesic ear drops added to usual care provide superior ear pain relief over usual care alone in children presenting to primary care with AOM. METHODS AND ANALYSIS: This is a pragmatic, two-arm, individually randomised, open, superiority trial with cost-effectiveness analysis and nested mixed-methods process evaluation in general practices in the Netherlands. We aim to recruit 300 children aged 1–6 years with a general practitioner (GP) diagnosis of AOM and ear pain. Children will be randomly allocated (ratio 1:1) to either (1) lidocaine hydrochloride 5 mg/g ear drops (Otalgan) one to two drops up to six times daily for a maximum of 7 days in addition to usual care (oral analgesics, with/without antibiotics); or (2) usual care. Parents will complete a symptom diary for 4 weeks as well as generic and disease-specific quality of life questionnaires at baseline and 4 weeks. The primary outcome is the parent-reported ear pain score (0–10) over the first 3 days. Secondary outcomes include proportion of children consuming antibiotics, oral analgesic use and overall symptom burden in the first 7 days; number of days with ear pain, number of GP reconsultations and subsequent antibiotic prescribing, adverse events, complications of AOM and cost-effectiveness during 4-week follow-up; generic and disease-specific quality of life at 4 weeks; parents’ and GPs’ views and experiences with treatment acceptability, usability and satisfaction. ETHICS AND DISSEMINATION: The Medical Research Ethics Committee Utrecht, the Netherlands, has approved the protocol (21-447/G-D). All parents/guardians of participants will provide written informed consent. Study results will be submitted for publication in peer-reviewed medical journals and presented at relevant (inter)national scientific meetings. TRIAL REGISTRATION: The Netherlands Trial Register: NL9500; date of registration: 28 May 2021. At the time of publication of the study protocol paper, we were unable to make any amendments to the trial registration record in the Netherlands Trial Register. The addition of a data sharing plan was required to adhere to the International Committee of Medical Journal Editors guidelines. The trial was therefore reregistered in ClinicalTrials.gov (NCT05651633; date of registration: 15 December 2022). This second registration is for modification purposes only and the Netherlands Trial Register record (NL9500) should be regarded as the primary trial registration

    The importance of cardiovascular disease for mortality in patients with COPD: a prognostic cohort study

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    Background. Cardiovascular diseases are the major cause of mortality in patients with chronic obstructive pulmonary disease (COPD), however, are rarely considered in prediction models in patients with COPD. Objective. To quantify the effect of cardiovascular determinants on mortality in patients with a GP's diagnosis of COPD. Methods. Four hundred and five patients aged >65 years with a diagnosis of COPD (244 with COPD by spirometry) were followed up for an average period of 4.2 (SD 1.4) years. Cox proportional hazard regression analyses with bootstrapping techniques were performed to identify independent predictors of all-cause mortality. Results. In multivariable analysis, all-cause mortality was best predicted by age [hazard ratio Conclusions. Physicians should consider ischaemic heart disease in the clinical evaluation of any patient with a GP's diagnosis of COPD. Angina pectoris on history taking is a strong predictor of all-cause mortality in these patients and should be treated adequately to improve prognosis

    Определение интервалов квазистационарности экономических систем

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    В работе рассмотрен вопрос определения оптимального интервала адаптации алгоритма динамического управления капиталом для нестационарного случая методами расчета показателя Херста и построения автокорреляционной функции для анализа временных рядов. Проведен анализ влияния выбора интервала адаптации на эффективность алгоритма. Из анализа полученных результатов следует, что метод расчета показателя Херста позволяет более эффективно, чем метод построения автокорреляционной функции, определить интервал стационарности модели функционирования экономической системы.Робота присвячена питанню визначення оптимального інтервалу адаптації алгоритму динамічного керування капіталом для нестаціонарного випадку за допомогою методів розрахунку показника Херста і побудови автокореляційної функції задля аналізу часових рядів. Проведено аналіз впливу вибору інтервалу адаптації на ефективність алгоритму. Порівняння результатів проведеного аналізу дозволяє стверджувати, що метод розрахунку показника Херста дозволяє більш ефективно, ніж метод побудови автокореляційної функції, визначити інтервал стаціонарності моделі функціонування економічної системи
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