Search results for "Regression analysi"
showing 10 items of 813 documents
Information content of data and variables and types of weighting in least-squares regression methods
1990
Abstract Algorithms are given for evaluating the relative amount of useful information related to a particular parameter which is carried by individual data points and intervals of the variables. The algorithms provide an efficient means of using the information contained in a set of data. Applications to the optimization of weighting in regression methods are described. Several informational and combined informational-statistical types of weighting are studied as a means of improving the accuracy and precision of the parameters obtained by non-linear regression.
Modeling solid waste decomposition.
2004
The hydrolysis rate coefficients of sorted municipal waste were evaluated from the biochemical methane potential tests using non-linear regression. A distributed mathematical model of anaerobic digestion of rich (food) and lean (non-food) solid wastes with greatly different rates of polymer hydrolysis/acidogenesis was developed to describe the balance between the rates of hydrolysis/acidogenesis and methanogenesis. The model was calibrated using previously published experimental data [Biores. Technol. 52 (1995) 245] obtained upon various initial food waste loadings. Simulations of one- and two-stage digestion systems were carried out. The results showed that initial spatial separation of fo…
Acoustic monitoring of the artificial airway — experimental results
1997
Non-invasive acoustic airway-monitoring was evaluated in an experimental study. Recording amplitude and travel time of acoustic pulse response, an acoustic pattern of airway's geometry was then calculated. Measurements on models and excised human cadaver lungs were performed to discover whether displacement or obstruction of the artificial airway could be detected by its acoustic equivalent. Regression analysis revealed a close correlation between displacement of tracheostomy tubes and the shifting of the acoustic area-distance function (corr. coeff.: 0.97-1) and an adequate correlation between acoustic and planimetrical determination of cross-sectional area within the tubes (corr. coeff.: …
Prediction of embryo survival and live birth rates after cryotransfers of vitrified blastocysts
2020
Which pre-vitrification parameters are the most predictive of survival and live birth in vitrified-warmed blastocyst transfer cycles?A retrospective study including 11,936 warmed blastocysts. Pre-vitrification morphological parameters analysed for blastocysts included day of vitrification; blastocyst expansion degree; trophoectoderm grade (A, B and C); and inner cell mass grade (A, B and C). Univariate and multivariate generalized estimating equations models were used to analyse survival, clinical pregnancy and live birth rate. A stepwise regression analysis was conducted to select and classify by order which outcomes were the most predictive.The odds of survival increased almost twice for …
Normal values of M mode echocardiographic measurements of more than 2000 healthy infants and children in central Europe
2000
OBJECTIVE—To obtain normal M mode (one dimensional) echocardiographic values in a substantial sample of normal infants and children. DESIGN—Data were obtained over three years from a single centre in central Europe. PATIENTS—2036 healthy infants and children aged one day to 18 years. METHODS—In line with recommendations for standardising measurements from M mode echocardiograms, and using digital echocardiographic equipment, measurements were obtained of the following: right ventricular anterior wall thickness at end diastole, right ventricular end diastolic dimension, thickness of interventricular septum at end diastole and end systole, thickness of posterior wall of the left ventricle at …
The use of control groups in artificial grammar learning.
2003
Experimenters assume that participants of an experimental group have learned an artificial grammar if they classify test items with significantly higher accuracy than does a control group without training. The validity of such a comparison, however, depends on an additivity assumption: Learning is superimposed on the action of non-specific variables—for example, repetitions of letters, which modulate the performance of the experimental group and the control group to the same extent. In two experiments we were able to show that this additivity assumption does not hold. Grammaticality classifications in control groups without training (Experiments 1 and 2) depended on non-specific features. T…
Hemostatic function in young subjects with central obesity: relationship with left ventricular function.
1995
This study was designed to evaluate coagulation and fibrinolysis activity and their relationship with left ventricular function in young obese subjects with central fat distribution. We assessed coagulation and fibrinolysis activity by evaluation of factor VII activity, fibrinogen and plasminogen, plasminogen activator inhibitor (PAI), and tissue plasminogen activator antigen basally (tPA1) and after venous occlusion (tPA2). These measures were evaluated in young (< 40 years) obese subjects with central fat distribution (n = 19) and in comparable lean subjects (n = 20). Blood glucose, triglycerides, total and high-density lipoprotein (HDL) cholesterol, apolipoprotein (apo) A1 and apo B, fas…
Ethnic differences in serum lipoproteins and their determinants in South African women.
2010
The objective of the study was to characterize ethnic differences in lipid levels and low-density lipoprotein (LDL) particle size and subclasses in black and white South African women and to explore the associations with insulin sensitivity (S(I)), body composition, and lifestyle factors. Fasting serum lipids and LDL size and subclasses, body composition (dual-energy x-ray absorptiometry), and S(I) (frequently sampled intravenous glucose tolerance test) were measured in normal-weight (body mass index25 kg/m(2)) black (n = 15) and white (n = 15), and obese (body mass index30 kg/m(2)) black (n = 13) and white (n = 13) women. Normal-weight and obese black women had lower triglycerides (0.59 +/…
Emotional intelligence and self-efficacy: effects on psychological well-being in college students.
2013
AbstractThe present paper examined the role of perceived emotional intelligence-EI- (measured by adaptations of the Trait Meta-Mood Scale - TMMS, Salovey, Mayer, Goldman, Turvey, & Palfai, 1995) as a predictor of life satisfaction and mental health. We explored the unique contribution of EI dimensions (Attention, Clarity and Repair) on individuals’ psychological well-being, after controlling for the influence of general self-efficacy and socio-demographic variables (age, gender and culture). Data was collected from a sample of 1078 Spanish, Mexican, Portuguese and Brazilian undergraduate students (Mage = 22.98; SD = 6.73) and analyzed using hierarchical multiple regressions. Results ind…
Childhood physical activity as a labor market investment
2020
This study examined the role of physical activity and changes in physical activity levels during childhood in long-term labor market outcomes. To address this important but under-researched theme, the study utilized data drawn from longitudinal research, the Cardiovascular Risk in Young Finns Study (YFS), and from registries compiled by Statistics Finland. The study consisted of children aged 9 (n = 1565) and 15 (n = 2445) at the time their physical activity was measured. Labor market outcomes, including employment status, average employment months, and average unemployment months, were calculated from 1997 to 2010, when the participants were aged 20 to 48 years. Regression models were used…