Marius A. Silaghi

Control of flow rate with fuzzy logic for ball mill

This paper presents a ball mill model. Starting with this mathematic model it is possible to achieve simulation results based on Matlab Simulink scheme. In this study, a fuzzy controller was designed for control flow rate inside the mill to avoid overfilling or emptying the mill. Finally, some simulation results are shown.

Evaluation of hilbert space techniques and lagrange's method for the analysis of dissipated power in DC circuits

The basic circuit laws of DC circuits are interpreted in this paper by defining suitable functionals in terms of dissipated power. It is then shown that the minimum of dissipated power determined by taking the derivative of these functionals verifies the first Kirchhoffs law. This allows interpreting the circuit equations by using the second Kirchhoffs law and the minimum power principles. In order to estimate the extreme values of dissipated power for DC circuits with modifiable parameters, and the relation between the variation in one or all the resistances of the networks and the variation of dissipated power we use the Lagranges method. Numerical examples obtained with Mathematica are provided to show the practical applications and comparison between of two proposed principles of DC circuits.

Front-end receiver: Recent and emerging trend

This paper describes the recent trend of front-end receiver systems for the application in radio monitoring. The receiver implementation is optimized for applications such as hunting and detecting unknown signals, identifying interference, spectrum monitoring and clearance, and signal search over wide frequency ranges, producing signal content and direction finding of identified signals.

Frequency signal source's PN (phase noise) measurements: Challenges and uncertainty

This paper describes oscillator noise measurement techniques, challenges and associated measurement uncertainty. The cross-correlation method used in modern PN measurement equipments, can present erroneous result, depending upon phase-inversion, harmonics, o/p load mismatch, and cable length. This discussion is imperative for low phase noise signal sources, validated with 2.4 GHz SAW oscillator, and discussed steps for mitigating these issues by using filtering/phase-matching N/W.

2D periodic structure featuring negative group velocity of bloch waves

A 2D, volumetric (i.e., non-planar), structure consisting of two dielectric layers, loaded by various metal inclusions on multiple-periodic grids and closed by two confining metal planes is introduced in view of advanced dispersion engineering related applications. Full-wave simulation has been used to demonstrate that, for axial propagation, the structure presents (i) a large electromagnetic band-gap and (ii) two modes that have anti-parallel phase and group velocities in different frequency bands where they do not interact with other modes.