نتایج جستجو برای ' transformation '

In this paper two nonlinear heat transfer problems were solved by considering variable specific heat coefficient. The calculations are carried out by using differential transformation method (DTM) which is a semi-numerical–analytical solution technique. By using DTM, the nonlinear constrained governing equations are reduced to recurrence relations and related initial conditions are transformed into a set of algebraic equations. The principle of differential transformation is briefly introd...

A numerical investigation is performed into the entropy generated within a mixed convection flow with viscous dissipation effects in a parallel-plate vertical channel. In performing the analysis, it is assumed that the flow within the channel is steady, laminar and fully developed. The governing equations for the velocity and temperature fields in the channel are solved using the differential transformation method. The numerical results for the velocity and temperature fields are found to be in ...

In this paper, we examine the convective flow and heat transfer of an incompressible viscous nanofluid past a semi-infinite vertical stretching sheet in the presence of a magnetic field. The governing partial differential equations with the auxiliary conditions are reduced to ordinary differential equations with the appropriate corresponding conditions via scaling transformations. The analytical solutions of the resulting ODEs are obtained, and from which the analytical solutions of the original...

This paper deals with the steady flow and heat transfer of a viscous incompressible power-law fluid over a rotating infinite disk. Assumed the thermal conductivity follows the same function as the viscosity, the governing equations in the boundary layer are transformed into a set of ordinary differential equations by generalized Karman similarity transformation. The corresponding nonlinear two-point boundary value problem was solved by multi-shooting method. Numerical results indicated that the ...

Process capability indices (PCIs) are used to measure process potential and performance. This study constructs an uniformly minimum variance unbiased estimator (UMVUE) of the lifetime performance index based on the upper record values for Weibull lifetime model. Then the UMVUE of the lifetime performance index is utilized to develop the new hypothesis testing procedure in the condition of known lower specification limit. Finally, two examples are presented to assess the behavior of this test sta...

Pathological processes cause abnormal regional motions of the heart. Regional wall motion analyses are important to evaluate the success of therapy, especially of cell therapy, since the recovery of the heart in cell therapy proceeds slowly and results in only small changes of ventricular wall motility. The usual ultrasound imaging of heart motion is too inaccurate to be considered as an appropriate method. MRI studies are more accurate, but insufficient to reliably detect small changes in regio...

It is well known in the literature that obtaining the parameter estimates for the Smooth Transition Autoregressive-Generalized Autoregressive Conditional Heteroskedasticity (STAR-GARCH) can be problematic due to computational difficulties. Conventional optimization algorithms do not seem to perform well in locating the global optimum of the associated likelihood function. This makes Quasi-Maximum Likelihood Estimator (QMLE) difficult to obtain for STAR-GARCH models in practice. Curiously, there ...

This study statistically examines an availability system with reboot delay, standby switching failures and an unreliable repair facility, which consists of two active components and one warm standby. The time-to-failure and the reboot time are assumed to be exponentially distributed. The repair time of the service station and the time-to-repair of component are assumed to be generally distributed. A consistent and asymptotically normal estimator of availability of such a repairable system is dev...

Second-order derivatives are crucial ingredients to a variety of numerical methods. Often, they are difficult to get with numerical differentiation by divided differencing. Automatic differentiation provides an alternative by a program transformation capable of evaluating Jacobians, Hessians, or higher-order derivatives of functions given in the form of computer programs. SEPRAN is a general-purpose finite element package written in Fortran 77 used in various scientific areas ranging from fluid ...