Amirkabir University of Technology
AUT Journal of Electrical Engineering
2588-2910
2588-2929
42
1
2010
04
01
Adaptive Optimum Notch Filter for Periodic Noise Reduction in Digital Images
1
7
EN
Payman
Moallemi
Corresponding Author, P. Moallem is with the Department of Electrical Engineering, University of Isfahan, Isfahan, Iran (e-mail:
p_moalem@ui.ac.ir).
Majid
Behnampourii
M. Behnampour is with Iran Aircraft Manufacturing (HESA), Shain Shar, Isfahan, Iran (e-mail: majidbehnam20@gmail.com).
10.22060/eej.2010.94
Periodic noises are unwished and spurious signals that create repetitive pattern on images and decreased the visual quality. Firstly, this paper investigates various methods for reducing the effects of the periodic noise in digital images. Then an adaptive optimum notch filter is proposed. In the proposed method, the regions of noise frequencies are determined by analyzing the spectral of noisy image. Then, the repetitive pattern of the periodic noise is produced by applying the corresponding notch pass filter. Finally, an output image with reduced periodic noise is restored by an optimum notch filter method. The results of the proposed adaptive optimum notch filter are compared by the mean and the median filtering techniques in frequency domain. The results show that the proposed filter has higher performances, visually and statistically, and has lower computational cost. In spite of the other compared methods, the proposed filter does not need to tune any parameters.
Periodic Noise,Optimum Notch Filter,Detection of Noisy Frequencies,Region Growing
http://eej.aut.ac.ir/article_94.html
http://eej.aut.ac.ir/article_94_befd8a642325852c3a0d41ece10b3feb.pdf
Amirkabir University of Technology
AUT Journal of Electrical Engineering
2588-2910
2588-2929
42
1
2010
04
01
Geometric Modeling of Dubins Airplane Movement and its Metric
9
16
EN
B.
Bidabadi
Corresponding Author, B. Bidabad, Department of Mathematics and Computer Sciences, Amirkabir University of Technology, Tehran, Iran.
(e-mail:bidabad@aut.ac.ir
M.
Sedaghat
M. Sedaghat, Department of Mathematics and Computer Sciences, Amirkabir University of Technology, Tehran, Iran. (e-mail:
m.sedaghat@aut.ac.ir)
10.22060/eej.2010.96
The time-optimal trajectory for an airplane from some starting point to some final point is studied by many authors. Here, we consider the extension of robot planer motion of Dubins model in three dimensional spaces. In this model, the system has independent bounded control over both the altitude velocity and the turning rate of airplane movement in a non-obstacle space. Here, in this paper a geometrization of time-optimal trajectory of Dubins airplane is also obtained. More intuitively, the metric related to this phenomenon is described as a geometry in space. It is shown that the distance traveled in movement of an airplane obeys certain conditions of a well-known geometry called Finsler geometry. Moreover, it is proved that the geometry of movement of an airplane is a special Finsler metric known as Randers metric, and therefore, time-optimal paths are geodesics of Randers metric.
Dubins airplane,Finsler metric,Indicatrix,Randers Metric,Control,Time-Optimal trajectories
http://eej.aut.ac.ir/article_96.html
http://eej.aut.ac.ir/article_96_c8e4003e45e60e4ea75cdf68584b29f6.pdf
Amirkabir University of Technology
AUT Journal of Electrical Engineering
2588-2910
2588-2929
42
1
2010
04
01
Optimization of an HTS Induction/Synchronous Motor According to Changing of HTS Tapes Critical Current by Analytical Hierarchy Process
17
29
EN
F.
Kazemzadehi
Corresponding Author, F. Kazemzadeh is with the High Voltage and Magnetic Material Research Center, Electrical Engineering Department,
Iran University of Science and Technology (IUST), Tehran 1684613114, Iran (e-mail: fkazemzadeh@elec.iust.ac.ir).
H.
Heydariii
H. Heydari is with the Center of Excellence for Power System Automation and Operation, Iran University of Science and Technology (IUST),
Tehran 1684613114, Iran (e-mail: heydari@iust.ac.ir).
10.22060/eej.2010.99
This paper represents the performance of a squirrel-cage High Temperature Superconducting Induction/ Synchronous Motor (HTS-ISM) based on nonlinear electrical equivalent circuit. The structure of the HTS-ISM is the same as that of the squirrel-cage type induction machine, and the secondary windings are fabricated by the use of the HTS wires. It has already been shown that based on the experiments that even this simple replacement realizes the excellent improvement of the performances such as coexistence of slip and synchronous rotations, higher efficiency (due to the synchronous operation), and robustness against the overload. In this paper, the transient modeling of this motor is performed by Matlab Simulink. Also, it is shown by FEM that starting and synchronous torque is extremely dependent on input voltage and critical current of superconducting tapes of the rotor. So, the starting and synchronous torque of the HTS induction motor can be improved with adjustment of the input voltage and critical current of the rotor HTS tapes. Also, in order to optimize both the starting and synchronous torques simultaneously, the relationship between these torques and the critical current of the HTS tapes have been investigated. Finally, according to the variation of the critical current, we optimized the design of the motor by analytical hierarchy process with finding the appropriate critical current for HTS tapes of rotor. The equations obtained are nonlinear, and then the typical Newton–Raphson method is used for the calculation.
HTS induction motor optimization,superconducting rotor,HTS-ISM,Analytical Hierarchy Process
http://eej.aut.ac.ir/article_99.html
http://eej.aut.ac.ir/article_99_b27a2fe793a4d9565de8947129e5413c.pdf
Amirkabir University of Technology
AUT Journal of Electrical Engineering
2588-2910
2588-2929
42
1
2010
04
01
A New Minimum Order Lumped-Parameter Model of Circulatory System for Patients with Suffered Left and Right-Sided Heart Failure
31
36
EN
E.
Rouhanii
Corresponding Author, E. Rouhani is with the Department of Electrical Engineering, Naghshejahan Institue, Esfahan, Iran (e.rouhani@aut.ac.ir)
S.
Gharibzadehii
S. Gharibzadeh is with the Department of Biomedical Engineering, Amirkabir University of Technology, Tehran, Iran (s.gharibzadeh@aut.ac.ir)
A.
Abootalebiiii
A.Abootalebi is with the Department of Electrical Engineering, Naghshejahan Institue, Esfahan, Iran (abootalebi_a@alumni.iut.ac.ir)
A
.Karimianiv
A. Karimian is with the Department of Electrical Engineering, Naghshejahan Institue, Esfahan, Iran (ali.karimian@pel.iaun.ac.ir)
F.
Khalili Esfahaniv
F. Khalili Esfahani is with the Department of Electrical Engineering, Naghshejahan Institue, Esfahan, Iran (farzadkhalili2010@gmail.com)
10.22060/eej.2010.101
In this study a new minimum lumped electrical model of total circulatory system through numerical solutions to approximate the response of the human circulatory system was presented. Among five existent ventricular elastances as activity function of heart pumps, a more accurate model was chosen as well as the operation of baroreflex system to accommodate variations in heart rate and systemic vascular resistance of a native human circulatory system. The model with extracting the hemodynamic reaction of a patient with heart failure has the ability to study completely the influence of left heart failure on the right ventricle performance. The model can be used to analyze the variations of pressure-volume loop curve for normal hearts and dilated and hypertrophic heart failure patients at rest. The simulation results, in comparison with the clinical data, showed that the model could efficiently simulate the progressed states of heart failure with an acceptable accuracy and among all studied states of disease, hypertrophic LS and RSHF state caused to make critical conditions for the simulated patient.
Circulatory system model,lumped,heart failure (HF)
http://eej.aut.ac.ir/article_101.html
http://eej.aut.ac.ir/article_101_873703ad899cf400baa8e2c18108b626.pdf
Amirkabir University of Technology
AUT Journal of Electrical Engineering
2588-2910
2588-2929
42
1
2010
04
01
Assessment of Weighting Functions Used in Oppermann Codes in Polyphase Pulse Compression Radars
37
43
EN
B.
Zakerii
B. Zakeri is with Babol University of Technology, Babol, Iran, (zakeri@nit.ac.ir)
M.
Zahabiii
M. R. Zahabi Babol University of Technology, Babol, Iran, (zahabi@nit.ac.ir)
S.
Alighale
Corresponding Author, S. Alighale is with Babol University of Technology, Babol, Iran, (Saeed.alighale@gmail.com)
10.22060/eej.2010.103
Polyphase is a common class of pulse compression waveforms in the radar systems. Oppermann code is one of the used codes with polyphone pattern. After compression, this code has little tolerant against Doppler shift in addition to its high side lobe level. This indicates that the use of Oppermann code is an unsuitable scheme to radars applications. This paper shows that the use of amplitude weighting functions improves properties of code and makes it an appropriate technique. Noticeable reduction in sidelobe and false alarm as well as the increase of the target detection ability and Doppler tolerant are the signature of amplitude weighting functions investigated and simulated in this study.
Pulse compression,polyphase,sidelobe,Oppermann code,window weighting function,Hamming,Hanning,Nuttallwin,Resolution,Peak power,width pulse
http://eej.aut.ac.ir/article_103.html
http://eej.aut.ac.ir/article_103_80557ad5c350a2b7b92a015a9dbb92bd.pdf
Amirkabir University of Technology
AUT Journal of Electrical Engineering
2588-2910
2588-2929
42
1
2010
04
01
Biomechanical Analysis of CNS Gray Matter in Tension and Compression
45
50
EN
Sina
Mehdizadehi
S. Mehdizadeh is with the Faculty of Biomedical Engineering, Amirkabir University of Technology, Tehran, Iran (e-mail:
s.mehdizadeh@aut.ac.ir).
Siamak
Najarianii
Corresponding Author, S. Najarian is with the Faculty of Biomedical Engineering, Amirkabir University of Technology, Tehran, Iran (e-mail:
najarian@aut.ac.ir).
Farhad
Farmanzadiii
F. Farmanzad is with the Department of Mechanical Engineering, Iran University of Science and Technology, Tehran, Iran (e-mail:
f.farmanzad@sazeh.co.ir).
Mehdi
Khoshgoftariv
M. Khoshgoftar is with the Faculty of Biomedical Engineering, Amirkabir University of Technology, Tehran, Iran (e-mail:
p.khoshgoftar.eng@gmail.com).
10.22060/eej.2010.105
The purpose of this study is to survey cross section changes of the animal brain samples during the tension and compression tests and comparison of the experimental results for three animals: bovine, sheep, and rabbit. A linear elastic theory with considering the necking in tension and barreling in compression has been considered for brain tissue. Bridgman method for tension and cross section updating method (using a picture analyzing through a computer program to trace cross section changes during the test) for compression has been applied in order to consider necking and barreling. It is shown that the effect of cross section changes of the samples during the test is not negligible. Differences in the behavior of brain tissue of bovine, sheep, and rabbit in both compression and tension are discussed. Results are in good agreement with previous works in the literature.
Biomechanics,Brain Tissue,Mechanical Behavior,Tension,Compression
http://eej.aut.ac.ir/article_105.html
http://eej.aut.ac.ir/article_105_0f0ce7408f0c08b727f32dcc8f42819f.pdf
Amirkabir University of Technology
AUT Journal of Electrical Engineering
2588-2910
2588-2929
42
1
2010
04
01
Image Steganalysis Based on Co-Occurrences of Integer Wavelet Coefficients
51
59
EN
M.
Abolghasemii
Corresponding Author, M. Abolghasemi is with the Department of Electrical Engineering, Amirkabir University of Technology, Tehran, Iran
(e-mail: mo_abolghasemi@aut.ac.ir).
H.
Aghaeiniaii
H. Aghaeinia is with the Department of Electrical Engineering, Amirkabir University of Technology, Tehran, Iran (e-mail: aghaeini@aut.ac.ir).
K.
Faeziii
K. Faez is with the Department of Electrical Engineering, Amirkabir University of Technology, Tehran, Iran (e-mail: kfaez@aut.ac.ir).
10.22060/eej.2010.107
We present a steganalysis scheme for LSB matching steganography based on feature vectors extracted from integer wavelet transform (IWT). In integer wavelet decomposition of an image, the coefficients will be integer, so we can calculate co-occurrence matrix of them without rounding the coefficients. Before calculation of co-occurrence matrices, we clip some of the most significant bitplanes of the coefficients. By this preprocessing, in addition to reducing the dimension of feature vector the effects of the embedding are also preserved. We test our algorithm for different embedding rats using Fisher linear discrimination (FLD) classifier and by comparing it with the current state-of-the-art steganalyzers; it is shown that the proposed scheme outperforms them by significant margin.
Integer wavelet transform (IWT),LSB matching,Steganography,Steganalysis
http://eej.aut.ac.ir/article_107.html
http://eej.aut.ac.ir/article_107_fcbb4f445b31f50a825b65b335607740.pdf
Amirkabir University of Technology
AUT Journal of Electrical Engineering
2588-2910
2588-2929
42
1
2010
04
01
PD Controller Design with H¥ Performance for Linear Systems with Input Delay
57
64
EN
Ala
Shariati
Corresponding Author, The authors are with the Advanced Robotic and Automates Systems (ARAS), Faculty of Electrical and Computer
Engineering, K. N. Toosi University of Technology, Tehran, Iran, (e-mail: Shariati@eetd.kntu.ac.ir).
Hamid D.
Taghirad
Corresponding Author, The authors are with the Advanced Robotic and Automates Systems (ARAS), Faculty of Electrical and Computer
Engineering, K. N. Toosi University of Technology, Tehran, Iran, (e-mail: Shariati@eetd.kntu.ac.ir).
10.22060/eej.2010.111
This paper presents H∞ control problem for input-delayed systems. A neutral system approach is considered to the design of PD controller for input delay systems in presence of uncertain time-invariant delay. Using this approach, the resulting closed-loop system turns into a specific time-delay system of neutral type. The significant specification of this neutral system is that its delayed coefficient terms depend on the controller parameters. This condition provides challenging issues in theoretical research and provides new horizons in applications. In the present paper, new delay-dependent sufficient condition is derived for the existence of H∞ controller in terms of matrix inequalities. The resulting H∞ controller stabilizes the closed-loop neutral system and assures that the H∞ performance norm to be less than a prescribed level. An application example is presented to illustrate the effectiveness of the proposed method.
H¥ Control,Neutral Systems,Uncertain Time-Invariant Delay,PD Control,Linear matrix inequality
http://eej.aut.ac.ir/article_111.html
http://eej.aut.ac.ir/article_111_2462876c626286739c990b9e5212bc05.pdf