Emmanuel Gonzalez - Academia.edu (original) (raw)
Books by Emmanuel Gonzalez
dial dial dial dial, la lluvia es la precipitación de partículas líquidas de agua de diáme-, la l... more dial dial dial dial, la lluvia es la precipitación de partículas líquidas de agua de diáme-, la lluvia es la precipitación de partículas líquidas de agua de diáme-, la lluvia es la precipitación de partículas líquidas de agua de diáme-, la lluvia es la precipitación de partículas líquidas de agua de diámetro mayor de 0.5 mm o de gotas menores, pero muy dispersas. tro mayor de 0.5 mm o de gotas menores, pero muy dispersas. tro mayor de 0.5 mm o de gotas menores, pero muy dispersas. tro mayor de 0.5 mm o de gotas menores, pero muy dispersas.
Papers by Emmanuel Gonzalez
Journal of Electroanalytical Chemistry and Interfacial Electrochemistry, Sep 1, 1989
... and FC Anson J Electroanal Chem, 215 (1986) 11 14 34 SW Feldberg, J Electroanal Chem , 222 (1... more ... and FC Anson J Electroanal Chem, 215 (1986) 11 14 34 SW Feldberg, J Electroanal Chem , 222 (1987) 101 35 D Bntz, Anal Chim Acta, 122 (1980) 331 36 AC Ramamurthy and SK ... 1. V.Vemuri and WJ Karplus , Digital Computer Treatment of Partial Differential Equations. ...
In this short note, we present the analog realization of a fractional-order differentiator of ord... more In this short note, we present the analog realization of a fractional-order differentiator of order α = 1/2 in 0.35 µm CMOS technology.
J Phys Chem a, 2008
Trigonal-planar, middle transition metal diiminato-imido complexes do not exhibit high-spin state... more Trigonal-planar, middle transition metal diiminato-imido complexes do not exhibit high-spin states, as might be naively expected on the basis of their low coordination numbers. Instead, the known Fe(III), Co(III), and Ni(III) complexes exhibit S = 3/2, S = 0, and S = 1/2 ground states, respectively. Kohn-Sham DFT calculations have provided a basic molecular orbital picture of these compounds as well as a qualitative rationale for the observed spin states. Reported herein are ab initio multiconfiguration second-order perturbation theory (CASPT2) calculations, which provide a relatively detailed picture of the d-d excited-state manifolds of these complexes. Thus, for a C(2v) Fe(III)(diiminato)(NPh) model complex, two near-degenerate states ((4)B(2) and (4)B(1)) compete as contenders for the ground state. Moreover, the high-spin sextet, two additional quartets and even a low-spin doublet all occur at <0.5 eV, relative to the ground state. For the Co(III) system, although CASPT2 reproduces an S = 0 ground state, as observed experimentally for a related complex, the calculations also predict two exceedingly low-energy triplet states; there are, however, no other particularly low-energy d-d excited states. In contrast to the Fe(III) and Co(III) cases, the Ni(III) complex has a clearly nondegenerate (2)B(2) ground state. The CASPT2 energetics provide benchmarks against which we can evaluate the performance of several common DFT methods. Although none of the functionals examined perform entirely satisfactorily, the B3LYP hybrid functional provides the best overall spin-state energetics.
Inorganic Chemistry, Aug 1, 2009
X-ray crystallographic analyses of two sterically unhindered copper meso-triarylcorroles, Cu[5,15... more X-ray crystallographic analyses of two sterically unhindered copper meso-triarylcorroles, Cu[5,15-P 2 -10-(4-MeOP)C] and Cu[5,15-(4-CF 3 P) 2 -10-(4-MeOP)C] (P = phenyl and C = corrole), revealed substantially saddled corrole rings. These results are in marked contrast to those on highly sterically hindered cobalt(III) and iridium(III) corroles, which exhibit planar corrole macrocycles. The solution to this conundrum is that copper corroles are inherently saddled, as a result of a specific copper(d)-corrole(π) orbital interaction. This orbital interaction results in a noninnocent corrole ligand, and the overall electronic structure may thus be described as Cu II -corrole •2-. While many specific metal(d)macrocycle(π) orbital interactions are known for nonplanar metalloporphyrins, this work provides a rare example of such an orbital interaction providing the actual driving force for a significant nonplanar distortion. Our findings on copper corroles, along with those of others on cobalt and iridium corroles, thus constitute an intriguing and somewhat counterintuitive chapter in the structural chemistry of metallocorroles.
Journal of Materials Science, Jun 1, 2005
The electronic structure and bonding at a Fe(110)Pd(100) interface was theoretically analyzed in... more The electronic structure and bonding at a Fe(110)Pd(100) interface was theoretically analyzed in the framework of semi-empirical quantum chemical calculations. The FePd interface was modeled by a Fe74Pd74 cluster and a FePd six layer slab. The extended H ¨uckel tight ...
2012 14th International Conference on Advanced Communication Technology, 2012
ABSTRACT Due to the complexity of service resources and the dynamics of application requirements ... more ABSTRACT Due to the complexity of service resources and the dynamics of application requirements in cloud computing, the objects and subjects of access control model constantly change. Consequently, traditional access control models no longer meet the requirements of cloud security. In this paper, a multi-objective decision-making model based on stochastic programming is proposed. By introducing new variables such as risk and utility, we are able to quantify the current state of the cloud environment. Afterwards, we can use this information to select appropriate safety decision variables to compute the model, taking the minimization of risk and the maximization of utility as the goals. The results obtained by solving the model can be used to allow or deny the user's requests, while considering the dynamic structure of the cloud. In this way, the security of cloud resources can be assured at its core. The experimental results show that, depending on the user requirements and the current cloud environment, solving the model can effectively be used to grant the user the appropriate permissions to access different service resources.
A great deal of modern methods for investigation, monitoring and control of the processes in the ... more A great deal of modern methods for investigation, monitoring and control of the processes in the area of mining and processing of earth resources utilize approaches based upon modeling of these processes using the mathematical or physical models. As it results from the last research works, majority of the real processes in general are fractional-order dynamical processes (arbitrary real order including integer order), however in some types of processes the order is very close to an integer order. In these cases the application of fractional-order models is more adequate than integer-order models for the investigation of these dynamical processes. Comparison of the methods for solving fractional-order mathematical models we have described in our past paper on the 10 th International Multidisciplinary Scientific Geo-Conference -SGEM 2011. The solution of many practical problems can be simplified with the help of electronic analog models utilizing so called fractional-order elements or constant phase elements. This paper is devoted to the design and realization of the electronic fractional-order model of the fractional-order system whose mathematical model is fractional-order differential equation. Along with the mathematical description, circuit diagrams and design procedure presented are also simulation results.
SGEM2011 11th International Multidisciplinary Scientific GeoConference, 2011
"One of the most characteristic features of the processes in the area of... more "One of the most characteristic features of the processes in the area of mining and processing of earth resources is their complexity. The modern methods of investigation, monitoring and control of these processes utilize approaches based upon modeling of the processes. In this paper we will focus only on the dynamical processes, where the mathematical models are differential equations. As it results from the last research works, majority of the real objects in general are fractional-order systems. Fractional order models are more adequate for the description of dynamical systems than integer order models. But appropriate methods for the numerical calculations of fractional-order differential equations are needed in such cases and also methods for the identification of such systems. In this contribution we describe and compare some previous methods used for simulation purposes with the methods based on approximate formulas for numerical inversion of Laplace transforms. The verification and comparison will be based mainly on the accuracy and computing time. Also an experimental method of identification is given. The verification of identification method was performed on systems with known parameters."
1 5/2010 www.strojarstvo.sk Metódy na riešenie Metódy na riešenie Metódy na riešenie Metódy na ri... more 1 5/2010 www.strojarstvo.sk Metódy na riešenie Metódy na riešenie Metódy na riešenie Metódy na riešenie diferenciálnych rovníc neceločíselné-ho rádu pre simulačné účely TEXT: prof. pokro-ky v danej oblasti, je možné zohľadňovať reálny rád aj pri popise dynamických systémov použitím diferenciálnych rovníc neceločíselného rádu. V takých prípadoch sú potrebné vhodné metódy pre numerické riešenie diferenciálnych rovníc neceločíselného rádu. V prí-spevku sú porovnané niektoré doterajšie metódy používané na simulačné účely s metóda-mi založenými na približných metódach pre numerickú inverziu Laplaceových obrazov. oci je teória derivácií a integrá-lov neceločíselného rádu (frac-tional-order, FO) stará už viac ako 300 rokov, jej hlavný rozvoj nastal až v devätnástom storočí. Aj v posled-ných desaťročiach sa okrem teoretic-kého výskumu derivácií a integrálov FO [1, 2, 3, 8] dosiahli významné výsledky aj v rozličných oblastiach aplikovaného výskumu ako napríklad dlhé elektrické vedenia, elekt...
Coordination Chemistry Reviews, 2007
Absorption spectra of octahedral nickel (II) complexes are used to illustrate that the limitation... more Absorption spectra of octahedral nickel (II) complexes are used to illustrate that the limitation to only the initial and Born–Oppenheimer final states of an electronic transition is not adequate in order to rationalize the intensity and vibronic structure of the lowest-energy ...
International Journal of Pure and Apllied Mathematics, 2014
The purpose of this note is to give an idea for graph theorists to explore a connection between c... more The purpose of this note is to give an idea for graph theorists to explore a connection between communication channels and graph theory as indicated in our conjectures below.
International Journal of Intelligent Control and Systems
The introduction of fractional calculus has spurred a lot of possibilities in biomedical engineer... more The introduction of fractional calculus has spurred a lot of possibilities in biomedical engineering and bioengineering research and development, especially in the modeling, design, and analysis of bioelectrodes. With the advent of memristors and fractional calculus, it is seen that these concepts would have several advantages and applications in such fields. In this short note, we present various bioelectrode equivalent circuit models including their impulse and frequency responses. The equivalent models presented utilize the concepts of memristors and fractional calculus.
(Available Online: http://viXra.org/abs/1401.0016) In this short note, we present the analog real... more (Available Online: http://viXra.org/abs/1401.0016) In this short note, we present the analog realization of a fractional-order differentiator of order α = 1/2 in 0.35 µm CMOS technology.
2007 37th annual frontiers in education conference - global engineering: knowledge without borders, opportunities without passports, 2007
Control systems engineering has been part of every engineering field. Whether in electrical, elec... more Control systems engineering has been part of every engineering field. Whether in electrical, electronic, computer, mechanical, or chemical engineering, control systems play a relevant part both in the academe and in the industry. Thus, there is a big need to develop strategies which will help undergraduate and graduate students of engineering learn more and obtain hands-on training when it comes to linear systems theory and control systems engineering. Furthermore, learning must be both conceptual and practical. In this paper, we present an educational tool, which is currently being developed by the authors, that can be used in teaching linear systems theory and control systems engineering in the undergraduate and graduate levels. The educational tool is a hardwaresoftware package designed to be used by instructors and students as well. Moreover, the educational tool comes with a manual for guided instructions. This paper discusses the complete conceptual design of the project and the proposed learning and implementing strategies. An evaluation plan will be used in determining the effectiveness of the tool upon its integration in an Electronics and Communications Engineering (ECE) and Computer Engineering (CoE) curricula.
Fractional Calculus and Applied Analysis, 2014
In the past decade, researchers working on fractional-order systems modeling and control have bee... more In the past decade, researchers working on fractional-order systems modeling and control have been considering working on the design and development of analog and digital fractional-order differentiators, i.e. circuits that can perform non-integer-order differentiation. It has been one of the major research areas under such field due to proven advantages over its integer-order counterparts. In particular, traditional integer-order proportional-integral-derivative (PID) controllers seem to be outperformed by fractional-order PID (FOPID or PI λ D µ ) controllers. Many researches have emerged presenting the possibility of designing analog and digital fractional-order differentiators, but only restricted to a fixed order. In this paper, we present the conceptual design of a variable fractional-order differentiator in which the order can be selected from 0 to 1 with an increment of 0.05. The analog conceptual design utilizes operational amplifiers and resistor-capacitor ladders as main components, while a generic microcontroller is introduced for switching purposes. Simulation results through MATLAB and LTSpiceIV show that the designed resistor-capacitor ladders can perform as analog fractional-order differentiation.
Proceedings of IEEE International Conference on Teaching, Assessment, and Learning for Engineering (TALE) 2012, 2012
ABSTRACT Work capacity models are very important tool in profiling a person against a defined set... more ABSTRACT Work capacity models are very important tool in profiling a person against a defined set of competencies usually related to knowledge and skills, and the person's physical and behavioral characteristics and constraints. In the case of an engineering student, for example, these set of competencies may be defined by a mentor or adviser such as, but are not limited to: knowledge on certain theoretical and practical aspects, skills in analyzing and designing engineering systems, leadership skills, and team-work, for example. Physical and behavioral characteristics, on the other hand, would depend on the person being assessed and various methods are also available in literature. However, work capacity models available in literature suffer from various drawbacks such as: 1) they do not reflect the fact that work capacity vary with time and external conditions; and 2) work capacity models are usually used to describe a single agent and not on a group of agents. In order to be able to include these drawbacks and convert them as added features, a dynamic input-output model describing the work capacity of a group of agents is devised using simple linear algebra and system theory concepts. We show that such models could be utilized in the academe in assessing the net work capacity (NWC) of a group of student working on a thesis topic, or even in the industry in assessing the NWC of a certain group of employees in a department, for example.
Proceedings of the 13th International Carpathian Control Conference (ICCC), 2012
Real objects in general are fractional-order (FO) systems, although in some types of systems the ... more Real objects in general are fractional-order (FO) systems, although in some types of systems the order is very close to an integer order. Also application of FO models is more adequate for the description of dynamical systems than integerorder models. This paper is devoted to the analogue electronic realization of the FO systems, e.g. controlled objects and/or controllers whose mathematical models are FO differential equations. The electronic realization is based on FO differentiator and FO integrator where operational amplifiers are connected with appropriate impedance or in our realization with so called Fractional Order Element (FOE) or Constant Phase Element (CPE). Presented network model in spite of its simplicity approximates quite well the properties of the ideal FO system compared with e.g. domino ladder networks. Also presented, along with the mathematical description, are simulation and measurement results.
Central European Journal of Physics, 2013
The number of studies on the control of fractional-order processes-processes having dynamics desc... more The number of studies on the control of fractional-order processes-processes having dynamics described by differential equations of arbitrary order-has been increasing in the past two decades and it is now ubiquitous. Various methods have emerged and have been proven to effectively control such processesusually resulting in fractional-order controllers similar to their conventional integer-order counterparts, which include, but are not limited to fractional PID and fractional lead-lag controllers. However, such methods require a lot of computational effort and fractional-order controllers could challenges when it comes to their synthesis and implementation. In this paper, we propose a simple yet effective delay-based controller with the use of the Posicast control methodology in controlling the overshoot of a fractional-order process of the class P : {P (s) = 1/(as α + b)} having orders 1 < α < 2. Such controllers have proven to be easy to implement because they only require delays and summers. In this paper, the Posicast control methodology introduced in the past few years is modified to minimize the overshoot of the processes step response to a level that is acceptable in control engineering and automation practices. Furthermore, proof of the existence of overshoot for such class of processes, as well as the determination of the peak-time of the open-loop response of a fractional-order process of the class P is presented. Validation through numerical simulations for a class of fractional-order processes are presented in this paper.
dial dial dial dial, la lluvia es la precipitación de partículas líquidas de agua de diáme-, la l... more dial dial dial dial, la lluvia es la precipitación de partículas líquidas de agua de diáme-, la lluvia es la precipitación de partículas líquidas de agua de diáme-, la lluvia es la precipitación de partículas líquidas de agua de diáme-, la lluvia es la precipitación de partículas líquidas de agua de diámetro mayor de 0.5 mm o de gotas menores, pero muy dispersas. tro mayor de 0.5 mm o de gotas menores, pero muy dispersas. tro mayor de 0.5 mm o de gotas menores, pero muy dispersas. tro mayor de 0.5 mm o de gotas menores, pero muy dispersas.
Journal of Electroanalytical Chemistry and Interfacial Electrochemistry, Sep 1, 1989
... and FC Anson J Electroanal Chem, 215 (1986) 11 14 34 SW Feldberg, J Electroanal Chem , 222 (1... more ... and FC Anson J Electroanal Chem, 215 (1986) 11 14 34 SW Feldberg, J Electroanal Chem , 222 (1987) 101 35 D Bntz, Anal Chim Acta, 122 (1980) 331 36 AC Ramamurthy and SK ... 1. V.Vemuri and WJ Karplus , Digital Computer Treatment of Partial Differential Equations. ...
In this short note, we present the analog realization of a fractional-order differentiator of ord... more In this short note, we present the analog realization of a fractional-order differentiator of order α = 1/2 in 0.35 µm CMOS technology.
J Phys Chem a, 2008
Trigonal-planar, middle transition metal diiminato-imido complexes do not exhibit high-spin state... more Trigonal-planar, middle transition metal diiminato-imido complexes do not exhibit high-spin states, as might be naively expected on the basis of their low coordination numbers. Instead, the known Fe(III), Co(III), and Ni(III) complexes exhibit S = 3/2, S = 0, and S = 1/2 ground states, respectively. Kohn-Sham DFT calculations have provided a basic molecular orbital picture of these compounds as well as a qualitative rationale for the observed spin states. Reported herein are ab initio multiconfiguration second-order perturbation theory (CASPT2) calculations, which provide a relatively detailed picture of the d-d excited-state manifolds of these complexes. Thus, for a C(2v) Fe(III)(diiminato)(NPh) model complex, two near-degenerate states ((4)B(2) and (4)B(1)) compete as contenders for the ground state. Moreover, the high-spin sextet, two additional quartets and even a low-spin doublet all occur at &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.5 eV, relative to the ground state. For the Co(III) system, although CASPT2 reproduces an S = 0 ground state, as observed experimentally for a related complex, the calculations also predict two exceedingly low-energy triplet states; there are, however, no other particularly low-energy d-d excited states. In contrast to the Fe(III) and Co(III) cases, the Ni(III) complex has a clearly nondegenerate (2)B(2) ground state. The CASPT2 energetics provide benchmarks against which we can evaluate the performance of several common DFT methods. Although none of the functionals examined perform entirely satisfactorily, the B3LYP hybrid functional provides the best overall spin-state energetics.
Inorganic Chemistry, Aug 1, 2009
X-ray crystallographic analyses of two sterically unhindered copper meso-triarylcorroles, Cu[5,15... more X-ray crystallographic analyses of two sterically unhindered copper meso-triarylcorroles, Cu[5,15-P 2 -10-(4-MeOP)C] and Cu[5,15-(4-CF 3 P) 2 -10-(4-MeOP)C] (P = phenyl and C = corrole), revealed substantially saddled corrole rings. These results are in marked contrast to those on highly sterically hindered cobalt(III) and iridium(III) corroles, which exhibit planar corrole macrocycles. The solution to this conundrum is that copper corroles are inherently saddled, as a result of a specific copper(d)-corrole(π) orbital interaction. This orbital interaction results in a noninnocent corrole ligand, and the overall electronic structure may thus be described as Cu II -corrole •2-. While many specific metal(d)macrocycle(π) orbital interactions are known for nonplanar metalloporphyrins, this work provides a rare example of such an orbital interaction providing the actual driving force for a significant nonplanar distortion. Our findings on copper corroles, along with those of others on cobalt and iridium corroles, thus constitute an intriguing and somewhat counterintuitive chapter in the structural chemistry of metallocorroles.
Journal of Materials Science, Jun 1, 2005
The electronic structure and bonding at a Fe(110)Pd(100) interface was theoretically analyzed in... more The electronic structure and bonding at a Fe(110)Pd(100) interface was theoretically analyzed in the framework of semi-empirical quantum chemical calculations. The FePd interface was modeled by a Fe74Pd74 cluster and a FePd six layer slab. The extended H ¨uckel tight ...
2012 14th International Conference on Advanced Communication Technology, 2012
ABSTRACT Due to the complexity of service resources and the dynamics of application requirements ... more ABSTRACT Due to the complexity of service resources and the dynamics of application requirements in cloud computing, the objects and subjects of access control model constantly change. Consequently, traditional access control models no longer meet the requirements of cloud security. In this paper, a multi-objective decision-making model based on stochastic programming is proposed. By introducing new variables such as risk and utility, we are able to quantify the current state of the cloud environment. Afterwards, we can use this information to select appropriate safety decision variables to compute the model, taking the minimization of risk and the maximization of utility as the goals. The results obtained by solving the model can be used to allow or deny the user's requests, while considering the dynamic structure of the cloud. In this way, the security of cloud resources can be assured at its core. The experimental results show that, depending on the user requirements and the current cloud environment, solving the model can effectively be used to grant the user the appropriate permissions to access different service resources.
A great deal of modern methods for investigation, monitoring and control of the processes in the ... more A great deal of modern methods for investigation, monitoring and control of the processes in the area of mining and processing of earth resources utilize approaches based upon modeling of these processes using the mathematical or physical models. As it results from the last research works, majority of the real processes in general are fractional-order dynamical processes (arbitrary real order including integer order), however in some types of processes the order is very close to an integer order. In these cases the application of fractional-order models is more adequate than integer-order models for the investigation of these dynamical processes. Comparison of the methods for solving fractional-order mathematical models we have described in our past paper on the 10 th International Multidisciplinary Scientific Geo-Conference -SGEM 2011. The solution of many practical problems can be simplified with the help of electronic analog models utilizing so called fractional-order elements or constant phase elements. This paper is devoted to the design and realization of the electronic fractional-order model of the fractional-order system whose mathematical model is fractional-order differential equation. Along with the mathematical description, circuit diagrams and design procedure presented are also simulation results.
SGEM2011 11th International Multidisciplinary Scientific GeoConference, 2011
&amp;amp;amp;quot;One of the most characteristic features of the processes in the area of... more &amp;amp;amp;quot;One of the most characteristic features of the processes in the area of mining and processing of earth resources is their complexity. The modern methods of investigation, monitoring and control of these processes utilize approaches based upon modeling of the processes. In this paper we will focus only on the dynamical processes, where the mathematical models are differential equations. As it results from the last research works, majority of the real objects in general are fractional-order systems. Fractional order models are more adequate for the description of dynamical systems than integer order models. But appropriate methods for the numerical calculations of fractional-order differential equations are needed in such cases and also methods for the identification of such systems. In this contribution we describe and compare some previous methods used for simulation purposes with the methods based on approximate formulas for numerical inversion of Laplace transforms. The verification and comparison will be based mainly on the accuracy and computing time. Also an experimental method of identification is given. The verification of identification method was performed on systems with known parameters.&amp;amp;amp;quot;
1 5/2010 www.strojarstvo.sk Metódy na riešenie Metódy na riešenie Metódy na riešenie Metódy na ri... more 1 5/2010 www.strojarstvo.sk Metódy na riešenie Metódy na riešenie Metódy na riešenie Metódy na riešenie diferenciálnych rovníc neceločíselné-ho rádu pre simulačné účely TEXT: prof. pokro-ky v danej oblasti, je možné zohľadňovať reálny rád aj pri popise dynamických systémov použitím diferenciálnych rovníc neceločíselného rádu. V takých prípadoch sú potrebné vhodné metódy pre numerické riešenie diferenciálnych rovníc neceločíselného rádu. V prí-spevku sú porovnané niektoré doterajšie metódy používané na simulačné účely s metóda-mi založenými na približných metódach pre numerickú inverziu Laplaceových obrazov. oci je teória derivácií a integrá-lov neceločíselného rádu (frac-tional-order, FO) stará už viac ako 300 rokov, jej hlavný rozvoj nastal až v devätnástom storočí. Aj v posled-ných desaťročiach sa okrem teoretic-kého výskumu derivácií a integrálov FO [1, 2, 3, 8] dosiahli významné výsledky aj v rozličných oblastiach aplikovaného výskumu ako napríklad dlhé elektrické vedenia, elekt...
Coordination Chemistry Reviews, 2007
Absorption spectra of octahedral nickel (II) complexes are used to illustrate that the limitation... more Absorption spectra of octahedral nickel (II) complexes are used to illustrate that the limitation to only the initial and Born–Oppenheimer final states of an electronic transition is not adequate in order to rationalize the intensity and vibronic structure of the lowest-energy ...
International Journal of Pure and Apllied Mathematics, 2014
The purpose of this note is to give an idea for graph theorists to explore a connection between c... more The purpose of this note is to give an idea for graph theorists to explore a connection between communication channels and graph theory as indicated in our conjectures below.
International Journal of Intelligent Control and Systems
The introduction of fractional calculus has spurred a lot of possibilities in biomedical engineer... more The introduction of fractional calculus has spurred a lot of possibilities in biomedical engineering and bioengineering research and development, especially in the modeling, design, and analysis of bioelectrodes. With the advent of memristors and fractional calculus, it is seen that these concepts would have several advantages and applications in such fields. In this short note, we present various bioelectrode equivalent circuit models including their impulse and frequency responses. The equivalent models presented utilize the concepts of memristors and fractional calculus.
(Available Online: http://viXra.org/abs/1401.0016) In this short note, we present the analog real... more (Available Online: http://viXra.org/abs/1401.0016) In this short note, we present the analog realization of a fractional-order differentiator of order α = 1/2 in 0.35 µm CMOS technology.
2007 37th annual frontiers in education conference - global engineering: knowledge without borders, opportunities without passports, 2007
Control systems engineering has been part of every engineering field. Whether in electrical, elec... more Control systems engineering has been part of every engineering field. Whether in electrical, electronic, computer, mechanical, or chemical engineering, control systems play a relevant part both in the academe and in the industry. Thus, there is a big need to develop strategies which will help undergraduate and graduate students of engineering learn more and obtain hands-on training when it comes to linear systems theory and control systems engineering. Furthermore, learning must be both conceptual and practical. In this paper, we present an educational tool, which is currently being developed by the authors, that can be used in teaching linear systems theory and control systems engineering in the undergraduate and graduate levels. The educational tool is a hardwaresoftware package designed to be used by instructors and students as well. Moreover, the educational tool comes with a manual for guided instructions. This paper discusses the complete conceptual design of the project and the proposed learning and implementing strategies. An evaluation plan will be used in determining the effectiveness of the tool upon its integration in an Electronics and Communications Engineering (ECE) and Computer Engineering (CoE) curricula.
Fractional Calculus and Applied Analysis, 2014
In the past decade, researchers working on fractional-order systems modeling and control have bee... more In the past decade, researchers working on fractional-order systems modeling and control have been considering working on the design and development of analog and digital fractional-order differentiators, i.e. circuits that can perform non-integer-order differentiation. It has been one of the major research areas under such field due to proven advantages over its integer-order counterparts. In particular, traditional integer-order proportional-integral-derivative (PID) controllers seem to be outperformed by fractional-order PID (FOPID or PI λ D µ ) controllers. Many researches have emerged presenting the possibility of designing analog and digital fractional-order differentiators, but only restricted to a fixed order. In this paper, we present the conceptual design of a variable fractional-order differentiator in which the order can be selected from 0 to 1 with an increment of 0.05. The analog conceptual design utilizes operational amplifiers and resistor-capacitor ladders as main components, while a generic microcontroller is introduced for switching purposes. Simulation results through MATLAB and LTSpiceIV show that the designed resistor-capacitor ladders can perform as analog fractional-order differentiation.
Proceedings of IEEE International Conference on Teaching, Assessment, and Learning for Engineering (TALE) 2012, 2012
ABSTRACT Work capacity models are very important tool in profiling a person against a defined set... more ABSTRACT Work capacity models are very important tool in profiling a person against a defined set of competencies usually related to knowledge and skills, and the person's physical and behavioral characteristics and constraints. In the case of an engineering student, for example, these set of competencies may be defined by a mentor or adviser such as, but are not limited to: knowledge on certain theoretical and practical aspects, skills in analyzing and designing engineering systems, leadership skills, and team-work, for example. Physical and behavioral characteristics, on the other hand, would depend on the person being assessed and various methods are also available in literature. However, work capacity models available in literature suffer from various drawbacks such as: 1) they do not reflect the fact that work capacity vary with time and external conditions; and 2) work capacity models are usually used to describe a single agent and not on a group of agents. In order to be able to include these drawbacks and convert them as added features, a dynamic input-output model describing the work capacity of a group of agents is devised using simple linear algebra and system theory concepts. We show that such models could be utilized in the academe in assessing the net work capacity (NWC) of a group of student working on a thesis topic, or even in the industry in assessing the NWC of a certain group of employees in a department, for example.
Proceedings of the 13th International Carpathian Control Conference (ICCC), 2012
Real objects in general are fractional-order (FO) systems, although in some types of systems the ... more Real objects in general are fractional-order (FO) systems, although in some types of systems the order is very close to an integer order. Also application of FO models is more adequate for the description of dynamical systems than integerorder models. This paper is devoted to the analogue electronic realization of the FO systems, e.g. controlled objects and/or controllers whose mathematical models are FO differential equations. The electronic realization is based on FO differentiator and FO integrator where operational amplifiers are connected with appropriate impedance or in our realization with so called Fractional Order Element (FOE) or Constant Phase Element (CPE). Presented network model in spite of its simplicity approximates quite well the properties of the ideal FO system compared with e.g. domino ladder networks. Also presented, along with the mathematical description, are simulation and measurement results.
Central European Journal of Physics, 2013
The number of studies on the control of fractional-order processes-processes having dynamics desc... more The number of studies on the control of fractional-order processes-processes having dynamics described by differential equations of arbitrary order-has been increasing in the past two decades and it is now ubiquitous. Various methods have emerged and have been proven to effectively control such processesusually resulting in fractional-order controllers similar to their conventional integer-order counterparts, which include, but are not limited to fractional PID and fractional lead-lag controllers. However, such methods require a lot of computational effort and fractional-order controllers could challenges when it comes to their synthesis and implementation. In this paper, we propose a simple yet effective delay-based controller with the use of the Posicast control methodology in controlling the overshoot of a fractional-order process of the class P : {P (s) = 1/(as α + b)} having orders 1 < α < 2. Such controllers have proven to be easy to implement because they only require delays and summers. In this paper, the Posicast control methodology introduced in the past few years is modified to minimize the overshoot of the processes step response to a level that is acceptable in control engineering and automation practices. Furthermore, proof of the existence of overshoot for such class of processes, as well as the determination of the peak-time of the open-loop response of a fractional-order process of the class P is presented. Validation through numerical simulations for a class of fractional-order processes are presented in this paper.
Proceedings of the 14th International Carpathian Control Conference (ICCC), 2013
Linear passive and active electric circuits can be viewed as two-port networks-having two readily... more Linear passive and active electric circuits can be viewed as two-port networks-having two readily-accessible electrical terminals usually denoted as input and output ports. Two-port networks, also known as four-terminal networks, are usually represented using matrices which allow the network to be analyzed easily without getting through internal current and voltages. In this paper we present the mathematical properties of a generalized fractional-order two-port network represented as a symmetrical T-section through its hybrid parameters.