magnetotelluric (mt) method is an important passive surface geophysical method which uses the earth’s natural electromagnetic fields to investigate the electrical resistivity structure of the subsurface. the depth of investigation of mt is much higher than that of other electromagnetic (em) methods (vozoff, 1991). for a general conductivity distribution in the earth, the horizontal electric fie...

The problem of translating a frequency domain impedance boundary condition to time domain involves the Fourier transform of the impedance function. This requires extending the definition of the impedance not only to all real frequencies but to the whole complex frequency plane. Not any extension, however, is physically possible. The problem should remain causal, the variables real, and the wall...

Electrical Impedance Tomography (EIT) is a imaging technique that attempts to reconstruct the impedance distribution inside an object from the impedance between electrodes placed at the object’s surface. The EIT reconstruction problem can be approached as a non-linear non-convex optimization problem where one tries to maximize the matching between a simulated impedance problem and the observed ...

In the previous lecture, we leant about impedance spectroscopy. Electrochemical impedance spectroscopy is the technique where the cell or electrode impedance is platted versus frequency. Thus, the impedance is measured as a function of the frequency of the AC source. Electrochemical impedance spectroscopy is a useful method for investigating porous electrodes, which are extensively used in the ...

An assessment of time-domain reflectometry (TDR) for measuring the characteristic impedance ZTL of transmission lines is performed. The assessment includes the accuracy of measuring ZTL as a function of TDR electrical impedance Zo, the ability to measure impedance perturbations as a function of ZTL and Zo, and the ability to differentiate between transmission lines of similar ZTL. The informati...

This paper presents the Function Approximation Technique (FAT) based adaptive impedance control for a robotic finger. The force based impedance control is developed so that the robotic finger tracks the desired force while following the reference position trajectory, under unknown environment position and uncertainties in finger parameters. The control strategy is divided into two phases, which...

U is a Hilbert space. By a L(U)-valued positive analytic function on C + (= the open right half-plane) we mean an analytic function which satisfies the condition b D+ b D 0. This function need not be proper, i.e., it need not be bounded on any right half-plane. We give a complete answer to the question under what conditions such a function can be realized as the transfer function of an (impedan...

− Nowadays, there are lots of classic and alternative method that has been used to obtain and compute transfer function for a linear network. Although, problems still occur especially in the number of nodes, loops and simultaneous equations that need to be solved by this approaches. A proposed approach called NIRE (Network-Impedance Relationship Equation) will solve these problems by developing...

We consider the reconstruction of complex obstacles from few farfield acoustic measurements. The complex obstacle is characterized by its shape and an impedance function distributed along its boundary through Robin type boundary conditions. This is done by minimizing an objective functional, which is the L distance between the given far field information g∞ and the far field of the scattered wa...