نتایج جستجو برای: fractional polynomial

تعداد نتایج: 156298  

Journal: :international journal of preventive medicine 0
mohammad reza baneshi fatemeh nakhaee matthew law

background: identification of disease risk factors can help in the prevention of diseases. in assessing the predictive value of continuous variables, a routine procedure is to categorize the factors. this yield to inability to detect non‑linear relationship, if exist. multivariate fractional polynomial (mfp) modeling is a flexible method to reveal non‑linear associations. we aim to demonstrate ...

A. Ramezanpour, F. Soltanian J. Vahidi, P. Reihani

In this article, Ritz approximation have been employed to obtain the numerical solutions of a class of the fractional optimal control problems based on the Caputo fractional derivative. Using polynomial basis functions, we obtain a system of nonlinear algebraic equations. This nonlinear system of equation is solved and the coefficients of basis polynomial are derived. The convergence of the num...

باغستانی, احمد رضا, حاجی زاده, ابراهیم, نور کجوری, هدی, پورحسینقلی, محمد‌امین ,

Background & Objectives: Cox regression model is one of the statistical methods in survival analysis. The use of smoothing techniques in Cox model makes the more accurate estimates for the parameters. Fractional polynomial is one of these techniques in Cox model. The aim of this study was to assess the effects of prognostic factors on survival of patients with gastric cancer using the fractiona...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه رازی - دانشکده علوم 1392

در سال 1972 کاکس مدلی را برای بررسی تاثیر متغییرهای مستقل بر روی تابع نرخ خطر در داده طول عمر معرفی کرد، استنباط در مورد تابع نرخ خطر مبنا که در مدل کاکس نقش مهمی دارد مربوط است به تحقیقاتی که برسلو(1972و1974) و کالب فلیش و پرانتیس(1973) انجام دادند، لاولس(1982) در مورد تحقیقات برسلو و براوردگرهای معرفی شده توسط او تحقیق نموده آنها را تائید نمود، البته براوردهای برسلو به دلیل سادگی در عمل دارای...

In this paper, we integrate goal programming (GP), Taylor Series, Kuhn-Tucker conditions and Penalty Function approaches to solve linear fractional bi-level programming (LFBLP)problems. As we know, the Taylor Series is having the property of transforming fractional functions to a polynomial. In the present article by Taylor Series we obtain polynomial objective functions which are equivalent...

Journal: :computational methods for differential equations 0
hossein pourbashash department of mathematics, university of garmsar, garmsar-iran

in this paper, a numerical efficient method is proposed for the solution of time fractionalmobile/immobile equation. the fractional derivative of equation is described in the caputosense. the proposed method is based on a finite difference scheme in time and legendrespectral method in space. in this approach the time fractional derivative of mentioned equationis approximated by a scheme of order o...

Journal: :Open Journal of Statistics 2018

In this paper, we develop a numerical resolution of the space-time fractional advection-dispersion equation. We utilize spectral-collocation method combining with a product integration technique in order to discretize the terms involving spatial fractional order derivatives that leads to a simple evaluation of the related terms. By using Bernstein polynomial basis, the problem is transformed in...

Journal: :Journal of University of Babylon 2022

We propose a fractional spline method for solving differential equations subject to initial conditions. Using the Caputo integral and derivative have construct interpolation with polynomial coefficients. For given function, error bounds were studied stability analysis was completed. The numerical explanation provided considered using three examples. results show that function which interpolates...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید