Liviu Florin Zoran, Carmen Ionescu Golovanov
This study focuses on the assessment of coastal zone land cover changes based on the fusion of satellite remote sensing data.The evaluation of coastal zone landscapes is based upon different sub- functions which refer to landscape features such as water, soil, land-use, buildings, groundwater, biotope types. Mixed pixels result when the sensor’s instantaneous field-of-view includes more than one land cover class on the ground. Based on different satellite data (Landsat MSS, TM, ETM, ERS, IKONOS, ASTER and MODIS) was performed object recognition for North-Western Black Sea coastal zone....
TC19 Symposium 2007
· TC19
· 2007
· Download
Slobodan Ðukanovic, Mauro D’Arco, Leopoldo Angrisani
The paper deals with signals that include nonstationary components. For these signals, the estimation of the instantaneous frequency of each component is especially difficult in time intervals where its trajectory interferes with another one, for example by crossing it. The attention is mainly paid to linear trajectories, seeing that any trajectory can be generally approximated as linear in the nearby of the crossing point. The authors propose a method based on the use of a two dimensional subspace of the chirplet transform, known as bowtie subspace, that allows accurate estimates of the...
TC4 Symposium 2007
· TC4
· 2007
· Download
Valeriy Martynyuk, Denis Makaryshkin, Juliy Boyko
In this paper we present the multi-channel measurement system based on potentiostatic, galvanostatic and potentiodynamic methods or combinations of the given measurement methods. The multi-channel measurement system is controlled with the special developed software. This system enables to perform the electrochemical supercapacitor time domain analysis more completely and with high accuracy.
TC4 Symposium 2007
· TC4
· 2007
· Download
Valeriy Martynyuk, Denis Makaryshkin, Juliy Boyko
The paper deals with the problem of creating a non-linear model of the electrochemical supercapacitors and measuring their electrical parameters in wide frequency range. Formalization of the model as a non-linear equivalent circuit enables to explain non-linear behavior of electrochemical supercapacitors such as dependence of their capacity and electrical series resistance (ESR) on the different voltage levels and frequencies. In order to determine the non-linear supercapacitor equivalent circuit parameters we carry out the impedance measurements and then perform fitting of obtained...
TC4 Symposium 2007
· TC4
· 2007
· Download
Gordan Štruklec, Vedran Bilas
Wireless automatic meter reading (AMR) system based on a fixed radio network brings many advantages when compared to other meter reading techniques. After an introduction to the state of the art of AMR systems in general, and particularly of water meter reading system, a wireless automatic water-meter reading system founded on ZigBee technology is presented. Set forth in the text are main characteristics of this low cost and low power system. The benefits of imlementing ZigBee protocol as the solution for the imposed requirements are rather thoroughly discussed, mainly in the aspect of...
TC4 Symposium 2007
· TC4
· 2007
· Download
Boris Šnajder, Darko Vasic, Vedran Bilas
A pulsed electromagnetic (PEM) technique is an effective method of nondestructive evaluation of steel tube inner diameter and wall thickness. Using time-spatial separation of direct-zone and remote-zone signals, it is possible to determine wall thickness and inner diameter with one receiving coil measuring voltage peak and zero-crossing time simultaneously. However, for fixed coil geometry the zero-crossing time can be recognized only for a limited range of wall thickness. In order to increase wall thickness range and shorten the probe, additional processing of the pulsed-eddy current signal...
TC4 Symposium 2007
· TC4
· 2007
· Download
Davor Živko, Vedran Bilas
Number of applications, power span and implementation areas for PEM (proton exchange membrane) fuel cells are increasing daily. All these applications require adequate measurement and control that will ensure optimal functionality of PEM fuel cell. Number of measuring quantities, especially in high – power systems, is numerous so pricing of measurement and control equipment is appreciable. In this paper we have implemented simple PEM fuel cell model and analyzed individual influences of fuel cell operating parameters, like temperature, partial pressures and membrane humidity. We have found...
TC4 Symposium 2007
· TC4
· 2007
· Download
Matei Mihaela Florentina, Mihai Petruta, Claudia Popescu, Mihai Octavian Popescu
The solar energy, like a permanent source of energy, is the optimal solution, and also a very important solution, for our investigations, because this source could solve a part of the problems related with inaccesibility and the high costs. A long series of projects are developing now, taking into consideration the importance of this problem. At University Politehnica of Bucharest, like a result of the PV Enlargement project exists a photovoltaic station. The actual system is analysed and a lot of conclusions are made, concerning the efficiency (as a result of these investigations we obtain...
TC4 Symposium 2007
· TC4
· 2007
· Download
Daniel Belega, Dominique Dallet
In this paper, a method to estimate the rms value of a noncoherent sampled sinewave by means of the formula used in an AC analog electronic voltmeter is presented. Adding some modifications on the algorithm, the accuracy obtained in this case was improved. This method is well suited for real-time applications in which the measurement of the sinewave rms value with relative high accuracy is sufficiently. The performances of the method proposed are proved by means of computer simulation as well as experimental results.
TC4 Symposium 2007
· TC4
· 2007
· Download
C. A. Nieto de Castro
The knowledge on the thermal conductivity of molten materials (salts, metals, semiconductors, polymers) is very scarce, both from the experimental and theoretical points of view. Knowing of the difficulty in obtaining accurate experimental data for most liquids, the task is uncouthly more difficult when the measurements are to be performed at medium and high temperatures with materials that are corrosive, easily reacting and good heat transfer media. Convective and radiative heat transfer effects affect in particular thermal conductivity measurements at high temperatures. These facts also...