960 resultados para Standard error
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Background and Purpose. Arm lymphedema following breast cancer In this study, we assessed the surgery is a continuing problem. reliability and validity of circumferential measurements and water displacement for measuring upper-limb volume. Subjects. Participants included subjects who had had breast cancer surgery, including axillary dissection-19 with and 22 without a diagnosis of arm lymphedema-and 25 control subjects. Methods. Two raters measured each subject by using circumferential tape measurements at specified distances from the fingertips and in relation to anatornic landmarks and by using water displacement. Interrater reliability was calculated by analysis of variance and multilevel modeling. Volumes from circumferential measurements were compared with those from water displacement by use of means and correlation coefficients, respectively. The standard error of measurement, minimum detectable change (MDC), and limits of agreement (LOA) for volumes also were calculated. Results. Arm volumes obtained with these methods had high reliability. Compared with volumes from water displacement, volumes from circumferential measurements had high validity, although these volumes were slightly larger. Expected differences between subjects with and without clinical lymphedema following breast cancer were found. The MDC of volumes or the error associated with a single measure for data based oil anatomic landmarks was lower than that based oil distance from fingertips. The mean LOA with water displacement were lower for data based on anatomic landmarks than for data based on distance from fingertips. Discussion and Conclusion. Volumes calculated from anatomic landmarks are reliable, valid, and more accurate than those obtained from circumferential measurements based on distance from fingertips.
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Studies suggest that enjoyment, perceived benefits and perceived barriers may be important mediators of physical activity. However, the psychometric properties of these scales have not been assessed using Rasch modeling. The purpose of this study was to use Rasch modeling to evaluate the properties of three scales commonly used in physical activity studies: the Physical Activity Enjoyment Scale, the Benefits of Physical Activity Scale and the Barriers to Physical Activity Scale. The scales were administered to 378 healthy adults, aged 25–75 years (50% women, 62% Whites), at the baseline assessment for a lifestyle physical activity intervention trial. The ConQuest software was used to assess model fit, item difficulty, item functioning and standard error of measurement. For all scales, the partial credit model fit the data. Item content of one scale did not adequately cover all respondents. Response options of each scale were not targeting respondents appropriately, and standard error of measurement varied across the total score continuum of each scale. These findings indicate that each scale's effectiveness at detecting differences among individuals may be limited unless changes in scale content and response format are made.
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Genetic parameters for performance traits in a pig population were estimated using a multi-trait derivative-free REML algorithm. The 2590 total data included 922 restrictively fed male and 1668 ad libitum fed female records. Estimates of heritability (standard error in parentheses) were 0.25 (0.03), 0.15 (0.03), and 0.30 (0.05) for lifetime daily gain, test daily gain, and P2-fat depth in males, respectively; and 0.27 (0.04) and 0.38 (0.05) for average daily gain and P2-fat depth in females, respectively. The genetic correlation between P2-fat depth and test daily gain in males was -0.17 (0.06) and between P2-fat and lifetime average daily gain in females 0.44 (0.09). Genetic correlations between sexes were 0.71 (0.11) for average daily gain and -0.30 (0.10) for P2-fat depth. Genetic response per standard deviation of selection on an index combining all traits was predicted at $AU120 per sow per year. Responses in daily gain and backfat were expected to be higher when using only male selection than when using only female selection. Selection for growth rate in males will improve growth rate and carcass leanness simultaneously.
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The paper examines howfar foreign manufacturing investment in UK industries, together with the spatial agglomeration of those industries, affect technical efficiency. The paper links research on the estimation of technical efficiency,with those literatures demonstrating the economies associated with foreign direct investment and spatial agglomeration. The methodology involves estimation of a stochastic production frontier with random components associated with industry technical inefficiency, and a standard error. The paper also explores whether the degree of foreign involvement has a greater impact on technical efficiency where the domestic industry sector is characterized by comparatively high productivity and spatial agglomeration. The policy implications of the analysis are discussed.
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Fifteen Miscanthus genotypes grown in five locations across Europe were analysed to investigate the influence of genetic and environmental factors on cell wall composition. Chemometric techniques combining near infrared reflectance spectroscopy (NIRS) and conventional chemical analyses were used to construct calibration models for determination of acid detergent lignin (ADL), acid detergent fibre (ADF), and neutral detergent fibre (NDF) from sample spectra. Results generated were subsequently converted to lignin, cellulose and hemicellulose content and used to assess the genetic and environmental variation in cell wall composition of Miscanthus and to identify genotypes which display quality traits suitable for exploitation in a range of energy conversion systems. The NIRS calibration models developed were found to predict concentrations with a good degree of accuracy based on the coefficient of determination (R2), standard error of calibration (SEC), and standard error of cross-validation (SECV) values. Across all sites mean lignin, cellulose and hemicellulose values in the winter harvest ranged from 76–115 g kg-1, 412–529 g kg-1, and 235–338 g kg-1 respectively. Overall, of the 15 genotypes Miscanthus x giganteus and Miscanthus sacchariflorus contained higher lignin and cellulose concentrations in the winter harvest. The degree of observed genotypic variation in cell wall composition indicates good potential for plant breeding and matching feedstocks to be optimised to different energy conversion processes.
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Background - The objective of this study was to investigate the association between ethnicity and health related quality of life (HRQoL) in patients with type 2 diabetes. Methods - The EuroQol EQ-5D measure was administered to 1,978 patients with type 2 diabetes in the UK Asian Diabetes Study (UKADS): 1,486 of south Asian origin (Indian, Pakistani, Bangladeshi or other south Asian) and 492 of white European origin. Multivariate regression using ordinary least square (OLS), Tobit, fractional logit and Censored Least Absolutes Deviations estimators was used to estimate the impact of ethnicity on both visual analogue scale (VAS) and utility scores for the EuroQol EQ-5D. Results - Mean EQ-5D VAS and utility scores were lower among south Asians with diabetes compared to the white European population; the unadjusted effect on the mean EQ-5D VAS score was −7.82 (Standard error [SE] = 1.06, p < 0.01) and on the EQ-5D utility score was −0.06 (SE = 0.02, p < 0.01) (OLS estimator). After controlling for socio-demographic and clinical confounders, the adjusted effect on the EQ-5D VAS score was −9.35 (SE = 2.46, p < 0.01) and on the EQ-5D utility score was 0.06 (SE = 0.04), although the latter was not statistically significant. Conclusions - There was a large and statistically significant association between south Asian ethnicity and lower EQ-5D VAS scores. In contrast, there was no significant difference in EQ-5D utility scores between the south Asian and white European sub-groups. Further research is needed to explain the differences in effects on subjective EQ-5D VAS scores and population-weighted EQ-5D utility scores in this context.
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Стефанка Чукова, Хър Гуан Тео - В това изследване разглеждаме и разширяваме предишната ни работа по цензуриране, типично за авто гаранционни данни. За да разрешим проблема с непълната информация за километража, използваме линеен подход в непараметрични рамки. Оценяваме средните кумулативни гаранционни разходи (за превозно средство) и стандартната им грешка като функция на възрастта, на километража и на реалното (календарно) време.
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This study is focused on the comparison and modification of different estimates arising in the branching processes. Simulations of models with or without migration are put through. Due to the complexity of the computations the algorithms are designed with the language of technical computing MATLAB. Using the simulations, estimates of the o spring mean of the generated processes are calculated. It is well known in the literature that under certain conditions the asymptotic distribution of the estimates is proved to be normal. Using the asymptotic normality a modified method of maximum likelihood is proposed. The aim is to obtain trimmed maximum likelihood estimates based on several sample paths with the same number of generations. Thus in a natural way the observations, inconsistent with the aprior information about the asymptotic normality are excluded from the model. The computation of the standard error allows the comparison of different types of estimates.
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2010 Mathematics Subject Classification: 62J99.
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This dissertation introduces a new system for handwritten text recognition based on an improved neural network design. Most of the existing neural networks treat mean square error function as the standard error function. The system as proposed in this dissertation utilizes the mean quartic error function, where the third and fourth derivatives are non-zero. Consequently, many improvements on the training methods were achieved. The training results are carefully assessed before and after the update. To evaluate the performance of a training system, there are three essential factors to be considered, and they are from high to low importance priority: (1) error rate on testing set, (2) processing time needed to recognize a segmented character and (3) the total training time and subsequently the total testing time. It is observed that bounded training methods accelerate the training process, while semi-third order training methods, next-minimal training methods, and preprocessing operations reduce the error rate on the testing set. Empirical observations suggest that two combinations of training methods are needed for different case character recognition. Since character segmentation is required for word and sentence recognition, this dissertation provides also an effective rule-based segmentation method, which is different from the conventional adaptive segmentation methods. Dictionary-based correction is utilized to correct mistakes resulting from the recognition and segmentation phases. The integration of the segmentation methods with the handwritten character recognition algorithm yielded an accuracy of 92% for lower case characters and 97% for upper case characters. In the testing phase, the database consists of 20,000 handwritten characters, with 10,000 for each case. The testing phase on the recognition 10,000 handwritten characters required 8.5 seconds in processing time.
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Objective: Establish intra- and inter-examiner reliability of glenohumeral range of motion (ROM) measures taken by a single-clinician using a mechanical inclinometer. Design: A single-session, repeated-measure, randomized, counterbalanced design. Setting: Athletic Training laboratory. Participants: Ten college-aged volunteers (9 right-hand dominant; 4 males, 6 females; age=23.2±2.4y, mass=73±16kg, height=170±8cm) without shoulder or neck injuries within one year. Interventions: Two Certified Athletic Trainers separately assessed passive glenohumeral (GH) internal (IR) and external (ER) rotation bilaterally. Each clinician secured the inclinometer to each subject’s distal forearm using elastic straps. Clinicians followed standard procedures for assessing ROM, with the participants supine on a standard treatment table with 90° of elbow flexion. A second investigator recorded the angle. Clinicians measured all shoulders once to assess inter-clinician reliability and eight shoulders twice to assess intra-clinician reliability. We used SPSS 14.0 (SPSS Inc., Chicago, IL) to calculate standard error of measure (SEM) and Intraclass Correlation Coefficients (ICC) to evaluate intra- and inter-clinician reliability. Main Outcome Measures: Dependent variables were degrees of IR, ER, glenohumeral internal rotation deficit (GIRD) and total arc of rotation. We calculated GIRD as the bilateral difference in IR (nondominant–dominant) and total arc for each shoulder (IR+ER). Results: Intra-clinician reliability for each examiner was excellent (ICC[1,1] range=0.90-0.96; SEM=2.2°-2.5°) for all measures. Examiners displayed excellent inter-clinician reliability (ICC[2,1] range=0.79-0.97; SEM=1.7°-3.0°) for all measures except nondominant IR which had good reliability(0.72). Conclusions: Results suggest that clinicians can achieve reliable measures of GH rotation and GIRD using a single-clinician technique and an inexpensive, readily available mechanical inclinometer.