nonlinear lumped-parameter model of a piezoelectric stack A, ctuator has been developed to describe actuator behavior for purposes of control system analysis and design, and, in particular, for microrobotic applications requiring accurate position andor force control. In formulating this model, the authors propose a generalized Maxwell resistive capacitor as a lumped-parameter causal representa...

We consider the initial-boundary value problem for an inhomogeneous time-fractional diffusion equation with a homogeneous Dirichlet boundary condition, a vanishing initial data and a nonsmooth right-hand side in a bounded convex polyhedral domain. We analyse two semidiscrete schemes based on the standard Galerkin and lumped mass finite element methods. Almost optimal error estimates are obtaine...

Computation of the broadband matching potential of a microstrip antenna requires the wideband lumped equivalent circuit of the antenna. The general topology of the equivalent circuit of rectangular microstrip patch antennas has been used to model the feedpoint impedance of microstrip antennas over a wide frequency band and equivalent circuit parameters are determined using optimization techniqu...

The technique presented in this paper allows the automatic construction of a lumped Markov chain for almost symmetrical Stochastic Well-formed Net (SWN) models. The starting point is the Extended Symbolic Reachability Graph (ESRG), which is a reduced representation of a SWN model reachability graph (RG), based on the aggregation of states into classes. These classes may be used as aggregates fo...

This survey is devoted to some fractional extensions of the incomplete lumped formulation, the lumped formulation and the formulation of Lauwerier of the temperature field problem in oil strata. The method of integral transforms is used to solve the corresponding boundary value problems for the fractional heat equation. By using Caputo’s differintegration operator and the Laplace transform, new...

A practical approach to determining the distributed capacitance and inductance of individual metamaterial resonators is demonstrated. By loading a set of lumped capacitors onto the resonator, the resonance frequency can be measured as a function of the load capacitance. The capacitance and inductance values of the resonator are then determined by relating the equivalent circuit model to the mea...

Coupling phenomena between artificial left-handed ~LH! transmission lines are explored on the basis of a transmission line approach of LH materials. A LH forward coupler in the form of an ideal lumped-element ladder network is presented and is shown to exhibit strong forward coupling that increases with decreasing of frequency. A quasi-lumped element microstrip implementation of a LH coupler is...

A frequency tunable planar inverted F antenna (PIFA) is presented for use in the following bands: DCS, PCS, and UMTS. Initially, the tuning was achieved by placing a lumped capacitor, with values in the range of 1.5 to 4 pF, along the slot of the radiator. The final tuning circuit uses a varactor diode, and discrete lumped elements are fully integrated with the antenna. The antenna prototype is...

In this paper, three disturbance compensation algorithms are experimentally evaluated considering the control problem of a rodless pneumatic cylinder. Despite its highly nonlinear dynamics, the pneumatic cylinder is modeled as a linear system including an unknown lumped disturbance. Three disturbance estimation algorithms are then employed to compensate for this lumped disturbance: the traditio...

A waveform adaptive physical model of the glottal source is proposed. The model relies on a lumped mechano aerodynamic schema loosely inspired to the oneand two-mass lumped models. The vocal folds are represented by a single mechanical resonator and a propagation line which takes into account the vertical phase differences. The vocal folds displacement is coupled to the glottal flow by means of...