Professor Milan Stork
Department of Applied Electronics and Telecommunications Faculty of Electrical Engineering, University of West Bohemia Univerzitni 26, 30614 Plzen
Czech Republic
e-mail: stork@kae.zcu.cz
OPPONENT REVIEW OF THE DISSERTATION
Name of the dissertation:
ANALOG IMPLEMENTATION OF FRACTIONAL-ORDER ELEMENTS AND THEIR APPLICATIONS
Graduate: Mgr.Aslihan Kartci
Study place: BRNO UNIVERSITY OF TECHNOLOGY, FACULTY OF
ELECTRICAL ENGINEERING AND COMMUNICATION, DEPARTMENT OF RADIO ELECTRONICS
The doctoral thesis is separated in 8 main chapters, bibliography and appendix and contain 143 pages.
Doctoral dissertation contains description concerning design of analog circuit design of fractional-order systems are covered: passive component optimization of resistive-capacitive and resistive-inductive type fractional-order elements, analog implementation of fractional- order integrators, robust fractional-order proportional integral control design, investigation of different materials for fractional-order capacitors fabrication having ultra-wide frequency band, low phase error, possible low and high-frequency realization of fractional-order oscillators in analog domain, mathematical and experimental study of solid-state fractional- order capacitors in series, parallel and interconnected circuit networks.
a) Topicality of the dissertation
The aim of work was design of fractional-order parts and dynamic systems e.g.: passive component optimization of resistive-capacitive and resistive-inductive type fractional order elements, active realization of fractional-order capacitors, analog integrated circuit design of fractional-order integrator, robust fractional-order proportional-integral control design, investigation of different materials for ultra-wide band, low phase error fractional-order capacitors, possible low and high - frequency realization of fractional order oscillators in analog circuit design, study of fractional order elements in series, parallel and interconnected networks.
b) Achievement of objectives
Objectives of dissertation were fulfilled. Mgr. Kartci analyzed problems of fractional order elements and system, designed and tested several new approach and introduced modern solution. The theoretical results was confirmed by system construction and measuring which is presented in chapters concerning fabrication of fractional-order capacitor, fractional orders networks and oscillators.
c) Chosen processing methods
It was chosen adequate modern methods for solving of task based on mathematic
solution which was confirmed by construction and measuring. It should also be noted that the results of Mgr. Kartci and coo workers were presented internationally in reviewed journals and conferences.
d) The results, original findings
Doctoral dissertation contains new findings and solutions of: optimization fractional- order elements using a genetic algorithm used for RC and RL networks, design of fractional- order controllers, fabrication of fractional-order capacitor, fractional-order connection of elements and fractional order oscillators.
e) Importance of the work for industry and development of science
The submitted dissertation is a important, interesting and brings original contribution in the field of fractional systems. Presented theory and results have not only a theoretical importance, but can be used in applications.
f) Final evaluation
The doctoral dissertation has been prepared on the high level. It is written in English. It has a good structure and I did not find any errors. I also appreciated author's 33 publications concerning fractional systems on international conferences and journals.
Mgr. Kartci has demonstrated that he can develop and apply new scientific methods and has contributed new findings in the field of fractional elements and systems.
I consider following points as greatest contribution:
Dissertation and also other scientific work of Mgr. Kartci brings a important results in the area of analog implementation of fractional order elements and applications such elements and systems.
The doctoral dissertation fulfils all conditions of the independent creative scientific research and contains the original results of the scientific research published by the author on adequate level, That is why
I recommend submitted doctoral dissertation for defense.
Reviewed in Pilsen on 6-th June 2019 by Prof. Ing. Milan Stork, CSc.
OPPONENT REVIEW OF THE DISSERTATION
Part: Questions
Name of the dissertation: ANALOG IMPLEMENTATION OF FRACTIONAL- ORDER ELEMENTS AND THEIR APPLICATIONS
Graduate: Mgr. Aslihan Kartci
Page 25, Fig. 2.1 It is: 1<α<2 should be -2<α<1 ?
Page 39, Tab. 3.1. Explain equations (is it continued fractions ?)
a)
b)
c)
d)
Page 40, in 3.2.1. explain “Pseudocapacitance”
Pages 43-53, I miss parts values of constructed networks Page 59, equation (14a,b) should be (4.14) ?
Page 61
“…λ = 0.89. As the Il is designed, the remaining design parameters can be recalculated using (4.14), which are the following: R = RP1 = RP3 = 10 kΩ, RP2 = 13.7 kΩ,
RPI1 = 27.4 kΩ, RPI2 = 1.3 kΩ, and RPI3 = 24.9 kΩ. An ideal…“
The RPI1, RPI2, and RPI3 should be RI1, RI2, and RI3 - which are used in eq. (14a,b) ? Page 62, bottom. Explain the X axis in figures 4.10
Page 106, 107
7.4 Fractional - Order Wien Oscillator
“…. Precision Impedance Analyzer with the 16048G model test fixture. Fig. 2(a) plots the phase of the impedance versus frequency and shows that it remains …”
“… which are extracted from impedance magnitude measurements, are shown in Fig. 2(b).”
Instead of Fig. 2(a) and Fig. 2(b) should be Fig. 7.19(a) and Fig. 7.19(b) ? Page 89, eq. (7.2) why is used |A| ?
Page 107, Wien oscillator, Fig. (7.20) – why the values of RFB and R3 are not shown ?
Page 108, “…This demonstrates that the fractional-order Wien oscillator has a significantly higher FO that its conventional counterpart.” Is it true only for fractional-order Wien oscillator?
Reviewed in Pilsen on 6-th June 2019 by Prof. Ing. Milan Stork, CSc.
