The test of homogeneity for intraclass correlation coefficients has been one of the active topics in statistical research. Several chi-square tests have been proposed to test the homogeneity of intraclass correlations in the past few decades. The big concern for them is that these methods are seriously biased when sample sizes are not large. In this thesis, data driven approaches are proposed t...

OBJECTIVE To investigate the cross-cultural validity of international Dutch-English comparisons when using the Dutch Rivermead Mobility Index (RMI), and the intra-test reliability and construct validity of the Dutch RMI. METHODS Cross-cultural validity was studied in a combined data-set of Dutch and English patients undergoing rehabilitation after stroke, who were assessed with the Dutch vers...

Introduction Superficial X-ray therapy is one of the most important treatment methods in radiotherapy especially in the treatment of superficial skin lesions (Up to 300 kVp). Quality of the X-ray beam that can be expressed by Half-Value Layer (HVL), are important indices for this type of treatment effective energy of photon and Homogeneity Coefficient (HC). Materials and Methods The HC of the s...

introduction: one of the major causes of image non-uniformity in mri is due to the existence of  non-homogeneity in rf receive and transmit. this can be the most effective source of error in  quantitative  studies  in  mri  imaging.  part  of  this  non-homogeneity  demonstrates  the  characteristics of rf coil and part of it is due to the interaction of rf field with the material being  imaged...

Introduction: One of the major causes of image non-uniformity in MRI is due to the existence of  non-homogeneity in RF receive and transmit. This can be the most effective source of error in  quantitative  studies  in  MRI  imaging.  Part  of  this  non-homogeneity  demonstrates  the  characteristics of RF coil and part of it is due to the interaction of RF field with the material being  imaged...

OBJECTIVE To compare the quality of fat suppression and image quality between multiecho Dixon technique (mDixon) and spectrally adiabatic iversion recovery (SPAIR) in dynamic contrast-enhanced magnetic resonance imaging of the prostate. METHODS This prospective study assigned thirty consecutive patients to scanning with SPAIR technique (SPAIR protocol) and another consecutive 30 patients to s...

BACKGROUND Nutritional screening instruments need to be evaluated in terms of reliability and validity and being able to demonstrate sensitivity and specificity for use in clinical practice and research. The aims of this study were to test the reliability and validity of the Norwegian version of the Nutritional Form For the Elderly (NUFFE-NO) in a sample of older home-dwelling people, and to us...

Random Coefficient Panel Data Models This paper provides a review of linear panel data models with slope heterogeneity, introduces various types of random coefficients models and suggest a common framework for dealing with them. It considers the fundamental issues of statistical inference of a random coefficients formulation using both the sampling and Bayesian approaches. The paper also provid...

The identification of alternatives to SF6 requires a study of the effective coefficient of electron attachment to electronegative gases and gas mixtures. One well established method for obtaining the attachment coefficient is the determination of swarm parameters using the pulsed Townsend discharge (PTD). From theoretical considerations and finite element calculations design guidelines for a PT...

OBJECTIVE To develop a hierarchical scale that measures activity limitations in walking in patients with lower-extremity disorders who live at home. DESIGN Cross-sectional study. SETTING Orthopedic workshops and outpatient clinics of secondary and tertiary care centers. PARTICIPANTS Patients (N=981; mean age +/- standard deviation, 58.6+/-15.4 y; 46% men) living at home, with different lo...