The importance of litter decomposition to carbon and nutrient cycling has motivated substantial research. Commonly, researchers fit a single-pool negative exponential model to data to estimate a decomposition rate (k). We review recent decomposition research, use data simulations, and analyze real data to show that this practice has several potential pitfalls. Specifically, two common decisions...

This paper is concerned with the existence of solutions for a new boundary value problem nonlinear coupled (k,?)–Hilfer fractional differential equations subject to (k,?)–Riemann–Liouville integral conditions. We prove two results by applying Leray–Schauder alternative, and Krasnosel’ski?’s fixed-point theorem under different criteria, while third result, concerning uniqueness given problem, re...

By usingMorse theory, the critical point theory, and the character ofK1/2, we consider the existence and multiplicity results of solutions to the following discrete nonlinear two-point boundary value problem −Δ2x k − 1 f k, x k , k ∈ Z 1, T subject to x 0 0 Δx T , where T is a positive integer, Z 1, T {1, 2, . . . , T},Δ is the forward difference operator defined by Δx k x k 1 − x k , and f : Z...

Least-Squares Support Vector Machines (LS-SVM’s), originating from Stochastic Learning theory, represent a promising approach to identify nonlinear systems via nonparametric estimation of nonlinearities in a computationally and stochastically attractive way. However, application of LS-SVM’s in the identification context is formulated as a linear regression aiming at the minimization of the l2 l...

GRAPPA linearly combines the undersampled k-space signals to estimate the missing k-space signals where the coefficients are obtained by fitting to some auto-calibration signals (ACS) sampled with Nyquist rate based on the shift-invariant property. At high acceleration factors, GRAPPA reconstruction can suffer from a high level of noise even with a large number of auto-calibration signals. In t...

In this article the problem of solving a system of singular nonlinear equations will be discussed. New the iterative 2-order method for this problem is presented. The article includes the numerical results for the method. 1. Problem Let : n n F D R R ⊂ → be a nonlinear operator, D is an open set. The point 0 x D ∈ is given. The problem of solving a system of nonlinear equations consists in find...

In this paper, we present new definitions of stability of singular systems with delay based on the works of B.Baji'c and M.Mili'c, and establish theorem on stability. Then the sufficient conditions for uniform stability of a class of special nonlinear singular systems with delay are suggested. Keywords: Nonlinear singular systems, singular systems with delay, stability, uniform stability. 1. IN...

Let q(x, t) satisfy the Dirichlet initial-boundary value problem for the nonlinear Schrödinger equation on the finite interval, 0 < x < L, with q 0 (x) = q(x, 0), g 0 (t) = q(0, t), f 0 (t) = q(L, t). Let g 1 (t) and f 1 (t) denote the unknown boundary values q x (0, t) and q x (L, t), respectively. We first show that these unknown functions can be expressed in terms of the given initial and bo...

The paper deals with continuous-time nonlinear adaptive control of a continuous stirred tank reactor. The control strategy is based on an application of the controller consisting of a linear and nonlinear part. The static nonlinear part is derived in the way of an inversion and exponential approximation of measured or simulated input-output data. The design of the two degrees of freedom (2DOF) ...