This study concerns with a trust-region-based method for solving unconstrained optimization problems. The approach takes the advantages of the compact limited memory BFGS updating formula together with an appropriate adaptive radius strategy. In our approach, the adaptive technique leads us to decrease the number of subproblems solving, while utilizing the structure of limited memory quasi-Newt...

It was shown in a previous work that some blind methods can be made robust to channel order overmodeling by using the l1 or lp quasi-norms. However, no theoretical argument has been provided to support this statement. In this work, we study the robustness of subspace blind based methods using l1 or lp quasi-norms. For the l1 norm, we provide the sufficient and necessary condition that the chann...

In this paper, a set of Root mean square derivative based closed Newton Cotes quadrature formula (RMSDCNC) is introduced in which the derivative value is included in addition to the existing closed Newton Cotes quadrature (CNC) formula for the calculation of a definite integral in the inetrval [a, b]. These derivative value is measured by using the root mean square value. The proposed formula y...

the spline collocation method  is employed to solve a system of linear and nonlinear fredholm and volterra integro-differential equations. the solutions are collocated by cubic b-spline and the integrand is approximated by the newton-cotes formula. we obtain the unique solution for linear and nonlinear system $(nn+3n)times(nn+3n)$ of integro-differential equations. this approximation reduces th...

A field experiment was performed from 2003 to 2008 to evaluate the effects of tillage system and nitrogen management regimes on crop yields and nitrate leaching from the fluvo-aquic soil with a winter wheat (Triticum aestivum L.)-maize (Zea mays L.) double-cropping system. The tillage systems consisted of conventional tillage (CT) and no-tillage (NT). Three nitrogen management regimes were incl...

Quasi-Newton methods based on least change secant updating formulas that solve linear equations Ax = b in n = dim(x) = dim(b) steps can be expected to solve corresponding smooth nonlinear systems n-step quadratically, i.e. with an r-order of ρ = 2 = 1 + 1/n+O(1/n). The best rate one can possibly expect on general problems is given by the positive root ρn of ρ (ρ− 1) = 1, for which ρn − 1 = ln(n...

While allowing for higher accuracy and more realistic results, multi-physics simulations induce challenges such as multi-scale effects, instabilities, and moving geometries. By breaking up multiphysics simulations into single-physics problems, we gain full flexibility in adding or exchanging model parts and reusing existing solvers. preCICE is a library for flexible numerical coupling of single...

Some global convergence properties of a variable metric algorithm for minimization without exact line searches, in R. 23 superlinear convergent algorithm for minimizing the Moreau-Yosida regularization F. However, this algorithm makes use of the generalized Jacobian of F, instead of matrices B k generated by a quasi-Newton formula. Moreover, the line search is performed on the function F , rath...