نتایج جستجو برای: polyvenile alchol sample

تعداد نتایج: 407479  

Journal: : 2022

Aim: The research was carried out to evaluate the confidence levels of women who exercise compared do not exercise.
 Method: This descriptive, cross-sectional and online study conducted with 311 aged 18 years older met criteria through social media groups between April 30 August 30, 2021. data were gathered using an introductory information form created by researchers which included questi...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه رازی - دانشکده علوم 1391

in this work, a novel and fast method for direct analysis of volatile compounds (davc) of medicinal plants has been developed by holding a filament from different parts of a plant in the gc injection port. the extraction and analysis of volatile components of a small amount of plant were carried out in one-step without any sample preparation. after optimization of temperature, extraction time a...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه رازی - دانشکده علوم 1388

چکیده: فرض کنید که تابعی از اپسیلون یک مجموع نامتناهی از احتمالات موزون مربوط به مجموع های جزئی براساس یک دنباله از متغیرهای تصادفی مستقل و همتوزیع باشد، و همچنین فرض کنید توابعی مانند g و h وجود دارند که هرگاه امید ریاضی توان دوم x متناهی و امیدریاضی x صفر باشد، در این صورت می توان حد حاصلضرب این توابع را بصورت تابعی از امید ریاضی توان دوم x نوشت. حالت عکس نیز برقرار است. همچنین ما با استفاده...

2015
Jonathan A Cook Jenni Hislop Douglas G Altman Peter Fayers Andrew H Briggs Craig R Ramsay John D Norrie Ian M Harvey Brian Buckley Dean Fergusson Ian Ford Luke D Vale

BACKGROUND Central to the design of a randomised controlled trial is the calculation of the number of participants needed. This is typically achieved by specifying a target difference and calculating the corresponding sample size, which provides reassurance that the trial will have the required statistical power (at the planned statistical significance level) to identify whether a difference of...

Journal: :Statistics in medicine 1998
F Y Hsieh D A Bloch M D Larsen

A sample size calculation for logistic regression involves complicated formulae. This paper suggests use of sample size formulae for comparing means or for comparing proportions in order to calculate the required sample size for a simple logistic regression model. One can then adjust the required sample size for a multiple logistic regression model by a variance inflation factor. This method re...

Journal: :Controlled clinical trials 2003
Roger P Qu Hongjie Zheng

Exact power and sample size calculation for bioequivalence studies with high order crossover designs using statistical software nQuery are presented. Such calculation can be very easily performed, and thus provides a convenient tool for practical usage.

Journal: :Journal of biopharmaceutical statistics 2005
Hansheng Wang Shein-Chung Chow Murphy Chen

In clinical research, parameters required for sample size calculation are usually unknown. A typical approach is to use estimates from some pilot studies as the true parameters in the calculation. This approach, however, does not take into consideration sampling error. Thus, the resulting sample size could be misleading if the sampling error is substantial. As an alternative, we suggest a Bayes...

Journal: :Journal of Surface Analysis 2019

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