in the research, six degrees of freedom hexapod parallel machine tool is studied and investigated. jacobian matrix is developed by cinematic relations differentiation and using weighted coefficient method, dimensional analysis operation is carried out on jacobian matrix. geometric parameters of cartesian robot workspace are optimized, considering a minimum allowable rotation about three axes, a...

the helicopter-borne electromagnetic (hem) frequency-domain exploration method is an airborne electromagnetic (aem) technique that is widely used for vast and rough areas for resistivity imaging. the vast amount of digitized data flowing from the hem method requires an efficient and accurate inversion algorithm. generally, the inverse modelling of hem data in the first step requires a precise a...

A parametric, continuous-time Markov model for digraph panel data is considered. The parameter is estimated by the method of moments. A convenient method for estimating the variance–covariance matrix of the moment estimator relies on the delta method, requiring the Jacobian matrix—that is, the matrix of partial derivatives—of the estimating function. The Jacobian matrix was estimated hitherto b...

Newton-Raphson State Estimation method using bus admittance matrix remains as an efficient and most popular method to estimate the state variables. Elements of Jacobian matrix are computed from standard expressions which lack physical significance. In this paper, elements of the state estimation Jacobian matrix are obtained considering the power flow measurements in the network elements. These ...

The helicopter-borne electromagnetic (HEM) frequency-domain exploration method is an airborne electromagnetic (AEM) technique that is widely used for vast and rough areas for resistivity imaging. The vast amount of digitized data flowing from the HEM method requires an efficient and accurate inversion algorithm. Generally, the inverse modelling of HEM data in the first step requires a precise a...

In this paper, we compare the effectiveness of three preconditioning strategies in simulations of variably saturated flow. Using Richards’ equation as our model, we solve the nonlinear system using a Newton-Krylov method. Since Krylov solvers can stagnate, resulting in slow convergence, we investigate different strategies of preconditioning the Jacobian system. Our work uses a multigrid method ...