Editor-in-Chief Lecture
Original Research Paper
M. Moradi; M.R. Sadeghi
Abstract
One of the serious issues in communication between people is hiding information from the others, and the best way for this, is to deceive them. Since nowadays face images are mostly used in three dimensional format, in this paper we are going to steganography 3-D face images and detecting which by curious ...
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One of the serious issues in communication between people is hiding information from the others, and the best way for this, is to deceive them. Since nowadays face images are mostly used in three dimensional format, in this paper we are going to steganography 3-D face images and detecting which by curious people will be impossible. As in detecting face only, its texture is important, we separate texture from shape matrices, for eliminating half of the extra information. Steganography is done only for face texture, and for reconstructing a 3-D face, we can use any other shape. Moreover, we will indicate that, by using two textures, how two 3-D faces can be combined. For a complete description of the process, first, 2-D faces are used as an input for building 3-D faces, and then 3-D face and texture matrices are extracted separately from the constructed 3-D face. Finally, 3-D textures are hidden within the other images.
Original Research Paper
M. Keshavarz; M.H. Shafiei
Abstract
In this paper, a novel approach for finite-time stabilization of uncertain affine systems is proposed. In the proposed approach, a fast terminal sliding mode (FTSM) controller is designed, based on the input-output feedback linearization of the nonlinear system with considering its internal dynamics. ...
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In this paper, a novel approach for finite-time stabilization of uncertain affine systems is proposed. In the proposed approach, a fast terminal sliding mode (FTSM) controller is designed, based on the input-output feedback linearization of the nonlinear system with considering its internal dynamics. One of the main advantages of the proposed approach is that only the outputs and external states of the system should be measured. Moreover, in order to realize finite-time convergence of the output variables, a set of switching manifolds with a recursive procedure is utilized. Finally, robust stability and efficacy of the proposed control law are shown through computer simulations.
Original Research Paper
A. Movahednasab; M. Rashidinejad; A. Abdollahi
Volume 5, Issue 2 , July 2017, Pages 109-120
Abstract
By increasing the extraction of natural gas, its role in the restructured power systems is being expanded, due to its lower pollution. Iran has the second largest reserves of natural gas in the world and exports it to different countries. This paper represents long run analysis of natural gas export ...
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By increasing the extraction of natural gas, its role in the restructured power systems is being expanded, due to its lower pollution. Iran has the second largest reserves of natural gas in the world and exports it to different countries. This paper represents long run analysis of natural gas export from Iran to Turkey as a case study, considering direct transfer and exporting via the power market. In this regard, a system dynamics model is approached for long run analysis of the considered scenarios. The uncertainty of natural gas price is modeled by Markov Chain Monte Carlo (MCMC) for a long run period and four generation technologies including coal-fired, combined cycle gas turbine (CCGT), gas turbine (GT) and wind participate in the power market with a uniform price structure. The published data by energy information administration (EIA) about natural gas charges, costs of electricity generation and export of natural gas and electricity are applied in the simulated models. The results show that exporting the natural gas at real time price is profitable, while its conversion into electricity and exporting at market price is disadvantageous, even by expanding the renewable resources.
Original Research Paper
S. Mahdavi
Abstract
A new high-resolution and high-speed fully differential Successive Approximation Register (SAR) Analog to Digital Converter (ADC) based on Capacitor Merged Technique is presented in this paper. The main purposes of the proposed idea are to achieve high-resolution and high-speed SAR ADC simultaneously ...
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A new high-resolution and high-speed fully differential Successive Approximation Register (SAR) Analog to Digital Converter (ADC) based on Capacitor Merged Technique is presented in this paper. The main purposes of the proposed idea are to achieve high-resolution and high-speed SAR ADC simultaneously as well. It is noteworthy that, exerting the suggested method the total capacitance and the ratio of the MSB and LSB capacitor are decreased, as a result, the speed and accuracy of the ADC are increased reliably. Therefore, applying the proposed idea, it is reliable that to attain a 12-bit resolution ADC at 76MS/s sampling rate. Furthermore, the power consumption of the proposed ADC is 694µW with the power supply of 1.8 volts correspondingly. The proposed post-layout SAR ADC structure is simulated in all process corner condition and different temperatures of -50℃ to +50℃, and performed using the HSPICE BSIM3 model of a 0.18µm CMOS technology.
Original Research Paper
S.A. Hossain; A. Mallik; Md. A. Arefin
Abstract
An inspection of signal processing approach in order to estimate underwater network cardinalities is conducted in this research. A matter of key prominence for underwater network is its cardinality estimation as the number of active cardinalities varies several times due to numerous natural and artificial ...
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An inspection of signal processing approach in order to estimate underwater network cardinalities is conducted in this research. A matter of key prominence for underwater network is its cardinality estimation as the number of active cardinalities varies several times due to numerous natural and artificial reasons due to harsh underwater circumstances. So, a proper estimation technique is mandatory to continue an underwater network properly. To solve the problem, we used a statistical tool called cross-correlation technique, which is a significant aspect in signal processing approach. We have considered the mean of cross-correlation function (CCF) of the cardinalities as the estimation parameter in order to reduce the complexity compared to the former techniques. We have used a suitable acoustic signal called CHIRP signal for the estimation purpose which can ensure better performance for harsh underwater practical conditions. The process is shown for both two and three sensors cases. Finally, we have verified this proposed theory by a simulation in MATLAB programming environment.
Original Research Paper
M.R. SHIRAVI; B. Ganji
Abstract
High-frequency coils are widely used in medical applications, such as Magnetic Resonance Imaging (MRI) systems. A typical medical MRI includes a local radio frequency transmit/receive coil. This coil is designed for maximum energy transfer or wave transfer through magnetic resonance. Mutual inductance ...
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High-frequency coils are widely used in medical applications, such as Magnetic Resonance Imaging (MRI) systems. A typical medical MRI includes a local radio frequency transmit/receive coil. This coil is designed for maximum energy transfer or wave transfer through magnetic resonance. Mutual inductance is a dynamic parameter that determines the energy quantity to be transferred wirelessly by electromagnetic coupling. Thus, it is essential to analyze the self and mutual inductances of this coil. Other parameters, including electromagnetic shielding, frequency, and distance, which influence voltage and power transfer are investigated here. Theoretical formulas and simulation models proposed in the present paper are implemented by using MATLAB and ANSYS MAXWELL and ANSYS SIMPLORER Finite Element (FE) packages for determining the performance and properties of the coil. So, the main goal is evaluating of software steps that simplify the design of RF resonance circuits. Also, experimental results are given for the validation of the proposed method. Consequently, Safety and efficiency are automatically maximized by following the best design considerations.
Original Research Paper
Y. Han; X. Cui; Y. Zhang; T. Xu
Abstract
In this paper, a color image watermarking algorithm based on Redundant Discrete Wavelet Transform (RDWT) and Singular Value Decomposition (SVD) is proposed. The new algorithm selects blue component of a color image to carry the watermark information since the Human Visual System (HVS) is least sensitive ...
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In this paper, a color image watermarking algorithm based on Redundant Discrete Wavelet Transform (RDWT) and Singular Value Decomposition (SVD) is proposed. The new algorithm selects blue component of a color image to carry the watermark information since the Human Visual System (HVS) is least sensitive to it. To increase the robustness especially towards affine attacks, RDWT is adopted for its excellent shift in-variance. In addition, the SVD technique can also ensure the robustness due to the eminent properties of singular values. It is worth mentioning that the watermark information is not processed by SVD in embedding procedure, which prevents the occurrence of false positive detection. Meanwhile, to acquire a balance between imperceptibility and robustness, various scaling factor values are used towards different sub-bands. Experimental results show that the proposed algorithm has outstanding security, imperceptibility and robustness.
Original Research Paper
S.M. Ahmadi; F. Parandin
Abstract
A solar cell is an electronic device which not only harvests photovoltaic effect but also transforms light energy into electricity. In photovoltaic phenomenon, a P-N junction is created to form an empty region. The presented paper aims at proposing a new highly efficient InGaN/Si double-junction ...
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A solar cell is an electronic device which not only harvests photovoltaic effect but also transforms light energy into electricity. In photovoltaic phenomenon, a P-N junction is created to form an empty region. The presented paper aims at proposing a new highly efficient InGaN/Si double-junction solar cell structure. This cell is designed to be used in a real environmental situation, so only structural parameters are optimized. In the present structure, a thin layer of Cd-S is used as the anti-reflector window layer. The cell is simulated using ATLAS-SILVACO software and its maximum efficiency is computed to be 37.23%. Considering the supposed structure, the findings show that the efficiency of this solar cell, which is 37.32%, is so far the highest reported efficiency amongst all solar cells.
Original Research Paper
H. Shayeghi; A. Ahmadpour; E. Mokaramian
Abstract
Power systems are subjected to small–signal oscillations that can be caused by sudden change in the value of large loads. To avoid the dangers of these oscillations, the Power System Stabilizers (PSSs) are used. When the PSSs can not be effective enough, installation of the Thyristor–based ...
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Power systems are subjected to small–signal oscillations that can be caused by sudden change in the value of large loads. To avoid the dangers of these oscillations, the Power System Stabilizers (PSSs) are used. When the PSSs can not be effective enough, installation of the Thyristor–based compensators to increase the oscillations damping is a suitable method. In this paper, a Static Synchronous Series Compensator (SSSC) is used in Single–Machine Infinite–Bus (SMIB). To control the signal of the output voltage of SSSC, a robust controller is used. Also, we proposed a hybrid control method to adjust the PSS voltage using Teaching–Learning Based Optimization (TLBO) algorithm and Fuzzy Inference System (FIS). Objective functions of designing parameters are based on Integral of Time multiplied by Absolute value of the Error (ITAE). The time–variations of angular speed deviations are investigated in different modes, including: with SSSC/PSS, without SSSC/PSS, different input mechanical power, and different system parameters.
Original Research Paper
M Basravi; Z.H. Firouzeh; M Maddahali
Abstract
A broadband Circuit Analogue (CA) absorber using double-circular-loop array is investigated in this paper. A simple equivalent circuit model is presented to accurately analyze this CA absorber. The circuit simulation of the proposed model agrees well with full-wave simulations. Optimization based the ...
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A broadband Circuit Analogue (CA) absorber using double-circular-loop array is investigated in this paper. A simple equivalent circuit model is presented to accurately analyze this CA absorber. The circuit simulation of the proposed model agrees well with full-wave simulations. Optimization based the equivalent circuit model, is applied to design a single-layer circuit analogue absorber using double-circular-loop array. Simple guidelines for designing the CA absorber are then formulated. It is demonstrated that the fractional bandwidth of 125.7% is realized for at least 10 dB reflectivity reduction with angular stability to 40˚ for both TM and TE modes. The total thickness of the absorber design is 0.093λL at the lowest operating frequency.
