RFID location systems for indoor and outdoor positioning are a promise for the future, even the p... more RFID location systems for indoor and outdoor positioning are a promise for the future, even the performances of these systems are affected by many factors. We identified here that for a system working in the RF band near 900 MHz, the objects interposed between the antenna system and the tags to be located may have a great influence in terms of accuracy of the measurement results. In closed areas multiple reflection paths may disturb the measurement systems, a percent of only 40 to 60 of total measurements are enough accurate to locate an object. In such conditions, there are small chances for this kind of systems to be used for high precision indoor applications requiring more than several tens of centimetres accuracy. The results obtained from the measurements we made in open area test sites are more promising, more than 93 percent of total result were not affected by notable errors. For speed measurement of mobile objects by using RFID systems, we may conclude there are many aspec...
A novel design for a mechanical-electrical transducer is presented in this article along with the... more A novel design for a mechanical-electrical transducer is presented in this article along with the preliminary testing of the transducer prototype. By using a Polaroid optocoupler as the motion sensor, this device combines the transducer feature to convert mechanical signals to electrical ones with the optoisolator feature of galvanic separation between two voltage modules. Signal conditioning circuit is a current-to-frequency converter, while the obtained signals are logically compatible and can be processed by a microprocessor. The device is aimed for application in the areas of automation and mechatronics.
ABSTRACT In spin crossover (SCO) systems, the shape of the hysteresis curves are closely related ... more ABSTRACT In spin crossover (SCO) systems, the shape of the hysteresis curves are closely related to the interactions between the molecules, which these play an important role in the response of the system to an external parameter. The effects of short-range interactions on the different shape of the spin transition phenomena were investigated. In this contribution we solve the corresponding Hamiltonian for a three-dimensional SCO system taking into account short-range and long-range interaction using a biased Monte Carlo entropic sampling technique and a semi-analytical method. We discuss the competition between the two interactions which governs the low spin (LS) - high spin (HS) process for a three-dimensional network and the cooperative effects. We demonstrate a strong correlation between the shape of the transition and the strength of short-range interaction between molecules and we identified the role of the size for SCO systems.
Mechanical-electrical optoisolator transducers are position transducers which use as a sensor, a ... more Mechanical-electrical optoisolator transducers are position transducers which use as a sensor, a Polaroid optocoupler specialized in converting rotation and/or translation movements into electrical signals. The used sensor is an analog device whose transfer characteristic is non-linear. In this article is presented a method of linearizing this new type sensors’s characteristic. The method is based on the analysis of the physical processes which take place within the Polaroid optocoupler. The mechanical-electrical optoisolator transducer allows the extraction of the signals out of the areas with intense electromagnetic field. Being an analog linear transducer, the signal generated by it doesn’t impose the use of a microprocessor. This thing permits to obtain some systems of checking the position of a machine-tool’s components at a low cost price.
This article presents a theoretical prediction of stochastic resonance in spin-crossover material... more This article presents a theoretical prediction of stochastic resonance in spin-crossover materials. The analysis of stochastic resonance phenomenon in a spin-crossover system is performed in the framework of the phenomenological kinetic model with light-induced transition described by dynamical potential in terms of the Lyapunov functions. By using numerical simulation of stochastic trajectories with white- and colored-noise action, the evaluation of stochastic resonance is carried out by signal-to-noise ratio of the system output. The corresponding signal-to-noise ratio features a two-peak behavior which is related to the asymmetric shape of the dynamic potential. For the case of the Ornstein-Uhlenbeck process, the variations of resonance condition with respect to different autocorrelation times are additionally studied.
This paper presents the framework of cyberinfrastructure and the state of the art in this area of... more This paper presents the framework of cyberinfrastructure and the state of the art in this area of research, as well as a preliminary analysis of a our university network capabilities for remote visualization and high performance computing. References are made to the cyber-tools and methods, such as high-performance computing, communication technologies, and simulation models, enabling progress in cyberinfrastructure development. The
ABSTRACT In the current study we report on the unusual results obtained in the framework of the a... more ABSTRACT In the current study we report on the unusual results obtained in the framework of the atom-phonon coupling model: two metastables states at low temperatures. These results can explain the experimental results reported by Ould Moussa et al. [9] and Matsumoto et al. [10] . This type of SCO behavior is due to the competition between the Light-Induced Excited Spin State Trapping (LIESST) effect, the elastic inter- action between the molecules and the thermal activation. In order to determine the stability of the states founded at low temperature, the free energy F is presented for the case of the two step spin transition of a SCO compound
Advances in Electrical and Computer Engineering, 2010
ABSTRACT This paper presents the results of the analysis of Polaroid optocoupler mechanical-elect... more ABSTRACT This paper presents the results of the analysis of Polaroid optocoupler mechanical-electrical sensor static characteristics. Our paper achieves analysis on distance adjustment Polaroid optocouplers of LED-photoresistor and LED-phototransistor types. These optocouplers analysis was performed in two distinct cases by using 0.2 mm and 0.7 mm thick Polaroid filters. At present, this Polaroid optocoupler mechanical-electrical sensor is only a prototype.
2010 12th International Conference on Optimization of Electrical and Electronic Equipment, 2010
ABSTRACT Mechanical-electrical Optoisolator Transducers are Polaroid optocouplers whose main func... more ABSTRACT Mechanical-electrical Optoisolator Transducers are Polaroid optocouplers whose main function is to convert a rotational and/or a translation movement into electrical signal. These devices combine transducers feature to connect two physical systems operating with signals of different nature, with optocouplers feature of galvanic separation of two different voltage modules. This is achieved by introducing a mechanically controlled system of Polaroid filters on the light beam path performing the optical coupling. These transducers are generally suitable for automation and mecatronics applications.
ISSCS 2011 - International Symposium on Signals, Circuits and Systems, 2011
... Octavian Modest MANU1, Mihai DIMIAN1, Ioan DUMITRU2, Adrian GRAUR1 1 Dept. of Electrical En... more ... Octavian Modest MANU1, Mihai DIMIAN1, Ioan DUMITRU2, Adrian GRAUR1 1 Dept. of Electrical Engineering and Computer Science, Stefan cel Mare University of Suceava, Romania octavianm@eed.usv.ro 2 Dept. of Physics, Alexandru Ioan Cuza University of Iasi ...
2012 13th International Conference on Optimization of Electrical and Electronic Equipment (OPTIM), 2012
ABSTRACT This paper presents a novel approach to studying electronics disciplines in technical ed... more ABSTRACT This paper presents a novel approach to studying electronics disciplines in technical educational programs based on a Mobile Studio Laboratory paradigm developed at the Rensselaer Polytechnic Institute. Several implementations are discussed and a comparative analysis between the Mobile Studio laboratories and the current standard ones is presented. This new educational approach provides an interactive technology - enhanced learning environment as well as a high level of individual experimentation both inside and outside the classrooms. As a result, theoretical concepts can be explain in an easy-to-grasp manner during the lecture by using the studio format while simultaneous individual experiments also allow the students to better understand the experimental deviations and the practical implications of the discussed theory. Although this solution lacks some of the characteristics and quality of modern laboratory measuring equipments it comes with a much lower cost and space needs and a much higher degree of mobility, being accessible to almost any student, anytime and anywhere.
ABSTRACT A study of thermal behavior for two-dimensional spin-crossover compounds is performed by... more ABSTRACT A study of thermal behavior for two-dimensional spin-crossover compounds is performed by using an Ising-like model including both short-range and long-range interactions and a Monte Carlo entropic sampling technique for determining the associated density of states. The effects of various factors, such as external pressure, internal interaction strength or system size, on the thermal transition are analyzed and compared to several experimental findings in this area. The study is focused on two-step transitions and the conditions for hysteresis behavior at each step which are especially important for the potential applications of spin-crossover materials in data storage devices or smart sensors.
ABSTRACT The spin – crossover compounds (SCO) have become of great interest recently due to their... more ABSTRACT The spin – crossover compounds (SCO) have become of great interest recently due to their potential applications in memories, sensors, switches, and display devices. These materials are particularly interesting because upon application of heat, light, pressure or other physical stimulus, they feature a phase transition between a low-spin (LS) diamagnetic ground state and a high-spin (HS) paramagnetic state, accompanied in some cases by color change. The phase transition can be discontinuous (with hysteresis), in two steps or gradual. Our analysis is performed by using the atom – phonon coupling (APC) model which considers that neighboring molecules are connected through a spring characterized by an elastic constant depending on molecules electronic state. By associating a fictitious spin to each molecule that has -1 and +1 eigenvalues corresponding to LS and HS levels respectively, an Ising type model can be developed for the analysis of metastable states and phase transitions in spin-crossover compounds. This contribution is aimed at providing a review of our recent results in this area, as well as novel aspects related to SCO compounds behavior at low temperature. In the framework of the APC model, we will discuss a bout the existence of metastable and unstable states, phase transitions and hysteresis phenomena, as well as their dependence on sample size.
ABSTRACT This article presents a theoretical and experimental study of designing a mechano-electr... more ABSTRACT This article presents a theoretical and experimental study of designing a mechano-electric optoisolator transducer with hysteresis. Our research is centred upon designing transducers on the basis of optical sensors, as photoelectric conversions eliminate the influence of electromagnetic disturbances. Conversion of the rotation/translation motions into electric signals is performed with the help of a LED-photoresistor Polaroid optocoupler. The driver of the optocoupler's transmitter module is an independent current source. The signal conditioning circuit is a Schmitt trigger circuit. The device is designed to be applied in the field of automation and mechatronics.
ABSTRACT The mixed hysteresis behavior of counter-clockwise and clockwise loops has recently attr... more ABSTRACT The mixed hysteresis behavior of counter-clockwise and clockwise loops has recently attracted the attention of the magnetics community, due to several experimental findings in inhomogeneous and hetero-structure magnetic systems. Various hybrid models are proposed here to address this behavior based on the superposition of standard hysteresis models and their newly developed clockwise variants. A special attention is also devoted to Bouc-Wen model, a typical clockwise often used by applied mechanics community, and to its relevance for mixed hysteresis. These clockwise and hybrid models have been implemented in an open-access academic software and their performance is illustrated by examples of hysteretic loops, first order reversal curves and diagrams simulated in this framework.
RFID location systems for indoor and outdoor positioning are a promise for the future, even the p... more RFID location systems for indoor and outdoor positioning are a promise for the future, even the performances of these systems are affected by many factors. We identified here that for a system working in the RF band near 900 MHz, the objects interposed between the antenna system and the tags to be located may have a great influence in terms of accuracy of the measurement results. In closed areas multiple reflection paths may disturb the measurement systems, a percent of only 40 to 60 of total measurements are enough accurate to locate an object. In such conditions, there are small chances for this kind of systems to be used for high precision indoor applications requiring more than several tens of centimetres accuracy. The results obtained from the measurements we made in open area test sites are more promising, more than 93 percent of total result were not affected by notable errors. For speed measurement of mobile objects by using RFID systems, we may conclude there are many aspec...
A novel design for a mechanical-electrical transducer is presented in this article along with the... more A novel design for a mechanical-electrical transducer is presented in this article along with the preliminary testing of the transducer prototype. By using a Polaroid optocoupler as the motion sensor, this device combines the transducer feature to convert mechanical signals to electrical ones with the optoisolator feature of galvanic separation between two voltage modules. Signal conditioning circuit is a current-to-frequency converter, while the obtained signals are logically compatible and can be processed by a microprocessor. The device is aimed for application in the areas of automation and mechatronics.
ABSTRACT In spin crossover (SCO) systems, the shape of the hysteresis curves are closely related ... more ABSTRACT In spin crossover (SCO) systems, the shape of the hysteresis curves are closely related to the interactions between the molecules, which these play an important role in the response of the system to an external parameter. The effects of short-range interactions on the different shape of the spin transition phenomena were investigated. In this contribution we solve the corresponding Hamiltonian for a three-dimensional SCO system taking into account short-range and long-range interaction using a biased Monte Carlo entropic sampling technique and a semi-analytical method. We discuss the competition between the two interactions which governs the low spin (LS) - high spin (HS) process for a three-dimensional network and the cooperative effects. We demonstrate a strong correlation between the shape of the transition and the strength of short-range interaction between molecules and we identified the role of the size for SCO systems.
Mechanical-electrical optoisolator transducers are position transducers which use as a sensor, a ... more Mechanical-electrical optoisolator transducers are position transducers which use as a sensor, a Polaroid optocoupler specialized in converting rotation and/or translation movements into electrical signals. The used sensor is an analog device whose transfer characteristic is non-linear. In this article is presented a method of linearizing this new type sensors’s characteristic. The method is based on the analysis of the physical processes which take place within the Polaroid optocoupler. The mechanical-electrical optoisolator transducer allows the extraction of the signals out of the areas with intense electromagnetic field. Being an analog linear transducer, the signal generated by it doesn’t impose the use of a microprocessor. This thing permits to obtain some systems of checking the position of a machine-tool’s components at a low cost price.
This article presents a theoretical prediction of stochastic resonance in spin-crossover material... more This article presents a theoretical prediction of stochastic resonance in spin-crossover materials. The analysis of stochastic resonance phenomenon in a spin-crossover system is performed in the framework of the phenomenological kinetic model with light-induced transition described by dynamical potential in terms of the Lyapunov functions. By using numerical simulation of stochastic trajectories with white- and colored-noise action, the evaluation of stochastic resonance is carried out by signal-to-noise ratio of the system output. The corresponding signal-to-noise ratio features a two-peak behavior which is related to the asymmetric shape of the dynamic potential. For the case of the Ornstein-Uhlenbeck process, the variations of resonance condition with respect to different autocorrelation times are additionally studied.
This paper presents the framework of cyberinfrastructure and the state of the art in this area of... more This paper presents the framework of cyberinfrastructure and the state of the art in this area of research, as well as a preliminary analysis of a our university network capabilities for remote visualization and high performance computing. References are made to the cyber-tools and methods, such as high-performance computing, communication technologies, and simulation models, enabling progress in cyberinfrastructure development. The
ABSTRACT In the current study we report on the unusual results obtained in the framework of the a... more ABSTRACT In the current study we report on the unusual results obtained in the framework of the atom-phonon coupling model: two metastables states at low temperatures. These results can explain the experimental results reported by Ould Moussa et al. [9] and Matsumoto et al. [10] . This type of SCO behavior is due to the competition between the Light-Induced Excited Spin State Trapping (LIESST) effect, the elastic inter- action between the molecules and the thermal activation. In order to determine the stability of the states founded at low temperature, the free energy F is presented for the case of the two step spin transition of a SCO compound
Advances in Electrical and Computer Engineering, 2010
ABSTRACT This paper presents the results of the analysis of Polaroid optocoupler mechanical-elect... more ABSTRACT This paper presents the results of the analysis of Polaroid optocoupler mechanical-electrical sensor static characteristics. Our paper achieves analysis on distance adjustment Polaroid optocouplers of LED-photoresistor and LED-phototransistor types. These optocouplers analysis was performed in two distinct cases by using 0.2 mm and 0.7 mm thick Polaroid filters. At present, this Polaroid optocoupler mechanical-electrical sensor is only a prototype.
2010 12th International Conference on Optimization of Electrical and Electronic Equipment, 2010
ABSTRACT Mechanical-electrical Optoisolator Transducers are Polaroid optocouplers whose main func... more ABSTRACT Mechanical-electrical Optoisolator Transducers are Polaroid optocouplers whose main function is to convert a rotational and/or a translation movement into electrical signal. These devices combine transducers feature to connect two physical systems operating with signals of different nature, with optocouplers feature of galvanic separation of two different voltage modules. This is achieved by introducing a mechanically controlled system of Polaroid filters on the light beam path performing the optical coupling. These transducers are generally suitable for automation and mecatronics applications.
ISSCS 2011 - International Symposium on Signals, Circuits and Systems, 2011
... Octavian Modest MANU1, Mihai DIMIAN1, Ioan DUMITRU2, Adrian GRAUR1 1 Dept. of Electrical En... more ... Octavian Modest MANU1, Mihai DIMIAN1, Ioan DUMITRU2, Adrian GRAUR1 1 Dept. of Electrical Engineering and Computer Science, Stefan cel Mare University of Suceava, Romania octavianm@eed.usv.ro 2 Dept. of Physics, Alexandru Ioan Cuza University of Iasi ...
2012 13th International Conference on Optimization of Electrical and Electronic Equipment (OPTIM), 2012
ABSTRACT This paper presents a novel approach to studying electronics disciplines in technical ed... more ABSTRACT This paper presents a novel approach to studying electronics disciplines in technical educational programs based on a Mobile Studio Laboratory paradigm developed at the Rensselaer Polytechnic Institute. Several implementations are discussed and a comparative analysis between the Mobile Studio laboratories and the current standard ones is presented. This new educational approach provides an interactive technology - enhanced learning environment as well as a high level of individual experimentation both inside and outside the classrooms. As a result, theoretical concepts can be explain in an easy-to-grasp manner during the lecture by using the studio format while simultaneous individual experiments also allow the students to better understand the experimental deviations and the practical implications of the discussed theory. Although this solution lacks some of the characteristics and quality of modern laboratory measuring equipments it comes with a much lower cost and space needs and a much higher degree of mobility, being accessible to almost any student, anytime and anywhere.
ABSTRACT A study of thermal behavior for two-dimensional spin-crossover compounds is performed by... more ABSTRACT A study of thermal behavior for two-dimensional spin-crossover compounds is performed by using an Ising-like model including both short-range and long-range interactions and a Monte Carlo entropic sampling technique for determining the associated density of states. The effects of various factors, such as external pressure, internal interaction strength or system size, on the thermal transition are analyzed and compared to several experimental findings in this area. The study is focused on two-step transitions and the conditions for hysteresis behavior at each step which are especially important for the potential applications of spin-crossover materials in data storage devices or smart sensors.
ABSTRACT The spin – crossover compounds (SCO) have become of great interest recently due to their... more ABSTRACT The spin – crossover compounds (SCO) have become of great interest recently due to their potential applications in memories, sensors, switches, and display devices. These materials are particularly interesting because upon application of heat, light, pressure or other physical stimulus, they feature a phase transition between a low-spin (LS) diamagnetic ground state and a high-spin (HS) paramagnetic state, accompanied in some cases by color change. The phase transition can be discontinuous (with hysteresis), in two steps or gradual. Our analysis is performed by using the atom – phonon coupling (APC) model which considers that neighboring molecules are connected through a spring characterized by an elastic constant depending on molecules electronic state. By associating a fictitious spin to each molecule that has -1 and +1 eigenvalues corresponding to LS and HS levels respectively, an Ising type model can be developed for the analysis of metastable states and phase transitions in spin-crossover compounds. This contribution is aimed at providing a review of our recent results in this area, as well as novel aspects related to SCO compounds behavior at low temperature. In the framework of the APC model, we will discuss a bout the existence of metastable and unstable states, phase transitions and hysteresis phenomena, as well as their dependence on sample size.
ABSTRACT This article presents a theoretical and experimental study of designing a mechano-electr... more ABSTRACT This article presents a theoretical and experimental study of designing a mechano-electric optoisolator transducer with hysteresis. Our research is centred upon designing transducers on the basis of optical sensors, as photoelectric conversions eliminate the influence of electromagnetic disturbances. Conversion of the rotation/translation motions into electric signals is performed with the help of a LED-photoresistor Polaroid optocoupler. The driver of the optocoupler's transmitter module is an independent current source. The signal conditioning circuit is a Schmitt trigger circuit. The device is designed to be applied in the field of automation and mechatronics.
ABSTRACT The mixed hysteresis behavior of counter-clockwise and clockwise loops has recently attr... more ABSTRACT The mixed hysteresis behavior of counter-clockwise and clockwise loops has recently attracted the attention of the magnetics community, due to several experimental findings in inhomogeneous and hetero-structure magnetic systems. Various hybrid models are proposed here to address this behavior based on the superposition of standard hysteresis models and their newly developed clockwise variants. A special attention is also devoted to Bouc-Wen model, a typical clockwise often used by applied mechanics community, and to its relevance for mixed hysteresis. These clockwise and hybrid models have been implemented in an open-access academic software and their performance is illustrated by examples of hysteretic loops, first order reversal curves and diagrams simulated in this framework.
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