Ioan Grosu | Universitatea Alexandru Ioan Cuza Iasi (original) (raw)

Papers by Ioan Grosu

Physics Education, 2016

This driven top is quite a novelty and can, with some trials, be made using the principles outlin... more This driven top is quite a novelty and can, with some trials, be made using the principles outlined here. This new top has many applications in developing both understanding and skills and these are detailed in the article. Depending on reader's available time and motivation they may feel an urge to make one themselves, or simply invest a few pounds in the one that has been designed, tested and manufactured to a high standard. Either way the unique design of the driven top can provide several hours of interesting experimentation. Our aim here is simply to inform and inspire readers to further investigation and experimentation.

2001 Conference Proceedings of the 23rd Annual International Conference of the IEEE Engineering in Medicine and Biology Society, 2001

Considering the highly nonlinear and non stationary features of the ECG signal proven by latest r... more Considering the highly nonlinear and non stationary features of the ECG signal proven by latest researches, the most appropriate methods of analysis are based also on the nonlinear dynamics; we used a modified root mean square analysis of a random walk, named detrended fluctuations analysis (DFA), which proved efficacy as diagnostic tool and advantages on the existing related methods. Our studies were conducted on two groups of young and old subjects, totally 24 patients, and the different behavior being related to the underlying dynamics of the heartbeat. We compare the data results using the DFA method: first when a line segment is fitted and second, when a quadratic polynomial is fitted in the least-squares sense Applications of this analysis may lead to new and safe diagnosis for patients and to evaluation of the patient status in systemic diseases that may affect in time the cardiovascular system.

IFAC Proceedings Volumes, 2001

The OPCL method is applied to reproducing a recorded chaotic dynamics and for controlling a chaot... more The OPCL method is applied to reproducing a recorded chaotic dynamics and for controlling a chaotic dynamics. Copyright ~20011FAC

The main goal of this paper is to study the synchronization of two identical chemical chaotic sys... more The main goal of this paper is to study the synchronization of two identical chemical chaotic systems proposed by Peng and coworkers, which is based on six rections and three intermediary species, using an adaptive feedback method. The transient time until synchronization depends on initial conditions of two systems, the strength and the number of the controllers. To achieve the synchronization is absolutely necessary to use two controllers, for example in the second and in the third equation from the slave system; if the time of synchronization might be longer than the previous case we can use only one controller, applied in the second equation of the tridimensional system.

International Journal of Research in Tourism and Hospitality

Anytime and any where a rainbow brings wonder, better mood, enthusiasm and well-being and many sm... more Anytime and any where a rainbow brings wonder, better mood, enthusiasm and well-being and many smiles. We present a simple and cheap installation that allows to obtain an artificial rainbow that is very similar with the natural one.On any sunnyday, tourists can enjoy a rainbow. This can increase the attractiveness of touristic places by innovation and the tourists satisfaction.

Chaos: An Interdisciplinary Journal of Nonlinear Science, Mar 15, 2011

Synchrony is an amazing natural phenomenon ubiquitous in the living world and also verified in la... more Synchrony is an amazing natural phenomenon ubiquitous in the living world and also verified in laboratory scale systems: chemical reaction, laser, and electronic circuits. Over the last two decades, the theoretical framework of synchronization of nonlinear oscillators, limit cycle and chaotic, is mainly established under unidirectional or mutual interactions and with complex topology. However, most of the theories start with an approximation of identical oscillators to reduce the burden of mathematical complexity to develop an understanding ...

Mathematical Problems in Engineering, 2016

Using the usual phase in plane, we propose a general method to design coupling between systems th... more Using the usual phase in plane, we propose a general method to design coupling between systems that will exhibit phase synchronization. Numerical results are shown for Lorenz systems. Phase synchronization and antiphase synchronization are equally probable depending on initial conditions. A new network with Lorenz phase synchronized system is obtained.

International Journal of Bifurcation and Chaos, Oct 1, 2007

A general coupling between three arbitrary identical oscillators is proposed and the synchronizat... more A general coupling between three arbitrary identical oscillators is proposed and the synchronization is analytically proved. Numerical results are given for a system that needs the simplest coupling.

A computer experiment for a driven gravitational pendulum is presented. It is shown linear and no... more A computer experiment for a driven gravitational pendulum is presented. It is shown linear and nonlinear and chaotic behaviour.

Journal de Physique, 1975

2014 On étudie l'effet d'un champ magnétique extérieur, à symétrie axiale sur un plasma autocompr... more 2014 On étudie l'effet d'un champ magnétique extérieur, à symétrie axiale sur un plasma autocomprimé. A l'aide d'un modèle qui généralise celui indiqué en [8], nous avons obtenu un système d'équations qui décrit la situation physique considérée. Les calculs numériques ont été réalisés à l'aide d'un schéma Lax-Wendorff, à double pas spatial et à pas temporel variable. Nous avons également analysé l'effet du champ magnétique extérieur sur différents paramètres : la vitesse du plasma, la température ionique, la température électronique et la densité du plasma. Les résultats théoriques concordent de manière satisfaisante avec les résultats expérimentaux [1], surtout pour les phases finales de la compression. A un certain stade, le rayon de la couche de plasma est plus grand en présence du champ magnétique extérieur qu'en son absence. Afin d'obtenir nos résultats, nous avons utilisé un plasma deutérium. Abstract. 2014 The effect of an external axial magnetic field on a selfcompressed plasma has been studied. Firstly, a set of equations describing the actual physical situation is derived by means of the generalized model described in [8]. Secondly, the results of a numerical calculation using a double spacestep and varying timestep in the Lax-Wendroff scheme are analysed. The effect of the external magnetic field on plasma parameters such as : plasma velocity, ion temperature, electron temperature and plasma density is analysed. The experimental results [1] are compared with theory and are found to be in good agreement especially for the later times of the compression stage. At one stage, the plasma column radius is greater than the corresponding one for the case with no magnetic field. All the calculations are performed for a deuterium gas compression.

Physics Education, 1994

USA %Institute of Technical Physics, 13-6600 lasi, Romania Here is a simple home experiment that ... more USA %Institute of Technical Physics, 13-6600 lasi, Romania Here is a simple home experiment that is easy to do and reveals some misunderstandings in physics. We take a simple transparent glass bottle of, say, 0.5 litres and fill it with ordinary water (figure I@)). A dry wooden match is then broken

Beiträge aus der Plasmaphysik, 1982

The plasma sheath acceleration in a system of two coaxial electrodes is studied by means of a two... more The plasma sheath acceleration in a system of two coaxial electrodes is studied by means of a two-dimensional snow-plow model presented in [9]. An improved expression for the variable plaamn inductance is used. The calculated values for the final axial velocity and the current intensity are in favorable agreement with experimental values. A comparison between the results of these calculations and those of some recent analytical models is presented.

American Journal of Physics, 1982

The Open Cybernetics & Systemics Journal, 2009

Physics Education, 2016

This driven top is quite a novelty and can, with some trials, be made using the principles outlin... more This driven top is quite a novelty and can, with some trials, be made using the principles outlined here. This new top has many applications in developing both understanding and skills and these are detailed in the article. Depending on reader's available time and motivation they may feel an urge to make one themselves, or simply invest a few pounds in the one that has been designed, tested and manufactured to a high standard. Either way the unique design of the driven top can provide several hours of interesting experimentation. Our aim here is simply to inform and inspire readers to further investigation and experimentation.

2001 Conference Proceedings of the 23rd Annual International Conference of the IEEE Engineering in Medicine and Biology Society, 2001

Considering the highly nonlinear and non stationary features of the ECG signal proven by latest r... more Considering the highly nonlinear and non stationary features of the ECG signal proven by latest researches, the most appropriate methods of analysis are based also on the nonlinear dynamics; we used a modified root mean square analysis of a random walk, named detrended fluctuations analysis (DFA), which proved efficacy as diagnostic tool and advantages on the existing related methods. Our studies were conducted on two groups of young and old subjects, totally 24 patients, and the different behavior being related to the underlying dynamics of the heartbeat. We compare the data results using the DFA method: first when a line segment is fitted and second, when a quadratic polynomial is fitted in the least-squares sense Applications of this analysis may lead to new and safe diagnosis for patients and to evaluation of the patient status in systemic diseases that may affect in time the cardiovascular system.

IFAC Proceedings Volumes, 2001

The OPCL method is applied to reproducing a recorded chaotic dynamics and for controlling a chaot... more The OPCL method is applied to reproducing a recorded chaotic dynamics and for controlling a chaotic dynamics. Copyright ~20011FAC

The main goal of this paper is to study the synchronization of two identical chemical chaotic sys... more The main goal of this paper is to study the synchronization of two identical chemical chaotic systems proposed by Peng and coworkers, which is based on six rections and three intermediary species, using an adaptive feedback method. The transient time until synchronization depends on initial conditions of two systems, the strength and the number of the controllers. To achieve the synchronization is absolutely necessary to use two controllers, for example in the second and in the third equation from the slave system; if the time of synchronization might be longer than the previous case we can use only one controller, applied in the second equation of the tridimensional system.

International Journal of Research in Tourism and Hospitality

Anytime and any where a rainbow brings wonder, better mood, enthusiasm and well-being and many sm... more Anytime and any where a rainbow brings wonder, better mood, enthusiasm and well-being and many smiles. We present a simple and cheap installation that allows to obtain an artificial rainbow that is very similar with the natural one.On any sunnyday, tourists can enjoy a rainbow. This can increase the attractiveness of touristic places by innovation and the tourists satisfaction.

Chaos: An Interdisciplinary Journal of Nonlinear Science, Mar 15, 2011

Synchrony is an amazing natural phenomenon ubiquitous in the living world and also verified in la... more Synchrony is an amazing natural phenomenon ubiquitous in the living world and also verified in laboratory scale systems: chemical reaction, laser, and electronic circuits. Over the last two decades, the theoretical framework of synchronization of nonlinear oscillators, limit cycle and chaotic, is mainly established under unidirectional or mutual interactions and with complex topology. However, most of the theories start with an approximation of identical oscillators to reduce the burden of mathematical complexity to develop an understanding ...

Mathematical Problems in Engineering, 2016

Using the usual phase in plane, we propose a general method to design coupling between systems th... more Using the usual phase in plane, we propose a general method to design coupling between systems that will exhibit phase synchronization. Numerical results are shown for Lorenz systems. Phase synchronization and antiphase synchronization are equally probable depending on initial conditions. A new network with Lorenz phase synchronized system is obtained.

International Journal of Bifurcation and Chaos, Oct 1, 2007

A general coupling between three arbitrary identical oscillators is proposed and the synchronizat... more A general coupling between three arbitrary identical oscillators is proposed and the synchronization is analytically proved. Numerical results are given for a system that needs the simplest coupling.

A computer experiment for a driven gravitational pendulum is presented. It is shown linear and no... more A computer experiment for a driven gravitational pendulum is presented. It is shown linear and nonlinear and chaotic behaviour.

Journal de Physique, 1975

2014 On étudie l'effet d'un champ magnétique extérieur, à symétrie axiale sur un plasma autocompr... more 2014 On étudie l'effet d'un champ magnétique extérieur, à symétrie axiale sur un plasma autocomprimé. A l'aide d'un modèle qui généralise celui indiqué en [8], nous avons obtenu un système d'équations qui décrit la situation physique considérée. Les calculs numériques ont été réalisés à l'aide d'un schéma Lax-Wendorff, à double pas spatial et à pas temporel variable. Nous avons également analysé l'effet du champ magnétique extérieur sur différents paramètres : la vitesse du plasma, la température ionique, la température électronique et la densité du plasma. Les résultats théoriques concordent de manière satisfaisante avec les résultats expérimentaux [1], surtout pour les phases finales de la compression. A un certain stade, le rayon de la couche de plasma est plus grand en présence du champ magnétique extérieur qu'en son absence. Afin d'obtenir nos résultats, nous avons utilisé un plasma deutérium. Abstract. 2014 The effect of an external axial magnetic field on a selfcompressed plasma has been studied. Firstly, a set of equations describing the actual physical situation is derived by means of the generalized model described in [8]. Secondly, the results of a numerical calculation using a double spacestep and varying timestep in the Lax-Wendroff scheme are analysed. The effect of the external magnetic field on plasma parameters such as : plasma velocity, ion temperature, electron temperature and plasma density is analysed. The experimental results [1] are compared with theory and are found to be in good agreement especially for the later times of the compression stage. At one stage, the plasma column radius is greater than the corresponding one for the case with no magnetic field. All the calculations are performed for a deuterium gas compression.

Physics Education, 1994

USA %Institute of Technical Physics, 13-6600 lasi, Romania Here is a simple home experiment that ... more USA %Institute of Technical Physics, 13-6600 lasi, Romania Here is a simple home experiment that is easy to do and reveals some misunderstandings in physics. We take a simple transparent glass bottle of, say, 0.5 litres and fill it with ordinary water (figure I@)). A dry wooden match is then broken

Beiträge aus der Plasmaphysik, 1982

The plasma sheath acceleration in a system of two coaxial electrodes is studied by means of a two... more The plasma sheath acceleration in a system of two coaxial electrodes is studied by means of a two-dimensional snow-plow model presented in [9]. An improved expression for the variable plaamn inductance is used. The calculated values for the final axial velocity and the current intensity are in favorable agreement with experimental values. A comparison between the results of these calculations and those of some recent analytical models is presented.

American Journal of Physics, 1982

The Open Cybernetics & Systemics Journal, 2009