List of Articles
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Open Access Article
1 - Defect Detection in Textile Fabrics Using Modified Local Binary Patterns
F. Tajeripour E. Kabir a. sheikhiOne of the methods which can produce powerful features for texture classification is Local Binary Patterns, LBP. In this paper we propose a method for defect detection in textile fabrics using these features. In the training stage, at first step LBP operator is applied MoreOne of the methods which can produce powerful features for texture classification is Local Binary Patterns, LBP. In this paper we propose a method for defect detection in textile fabrics using these features. In the training stage, at first step LBP operator is applied to an image of defect free fabric, pixel by pixel, and the reference feature vector is computed. Then this image is divided into windows and LBP operator is applied on each of these windows. Based on comparison to the reference feature vector a suitable threshold for defect free windows is found. In the detection stage, a test image is divided into windows and using the threshold, defective windows can be detected. The proposed method is gray scale and shift invariant and can be used for defect detection in patterned and plain fabrics. Due to its simplicity online implementation is possible. Manuscript profile -
Open Access Article
2 - Design and Implementation of a 125 kV/1000 kVA High-Voltage Test System Using Series-Resonance Technique
A. A. Lotfi-Neyestanak H. R. Sadegh MohammadiThis paper presents the design, analysis, simulation, and implementation of a high-power resonance generator for testing high-voltage capacitive loads. The resonance generator includes a variable reactor which is the most important part of the system, a shielded isolat MoreThis paper presents the design, analysis, simulation, and implementation of a high-power resonance generator for testing high-voltage capacitive loads. The resonance generator includes a variable reactor which is the most important part of the system, a shielded isolation transformer, a voltage regulator (auto-transformer), an exciter transformer, a capacitive divider, a control cubicle, a digital voltmeter, a computer based partial discharge measurement system, a high-voltage filter, and a low-voltage filter. The paper describes the analysis and simulation of different parts of the system. It also presents the results of tests were performed using the implemented system on different capacitive loads, including the measurements of harmonic distortions and partial discharge. The inductance measurement of the implemented variable reactor matches with the simulation results. The partial discharge measurement of the implemented high-voltage series-resonance test system shows that the system is PD free up to 70 kV. Manuscript profile -
Open Access Article
3 - Analysis and Simulation of the Microwave Heating Process in Crude Oils using FDTD Technique
A. MohammadiA new method to simulate the microwave heating process in crude oils has been presented. Using convolution ( or differential) relation between E and H fields, (FD)2TD method is extracted by modifying the conventional FDTD technique for depressive materials. It is shown MoreA new method to simulate the microwave heating process in crude oils has been presented. Using convolution ( or differential) relation between E and H fields, (FD)2TD method is extracted by modifying the conventional FDTD technique for depressive materials. It is shown that the computer time and memory requirements to analyze and simulate the microwave heating process are extensively reduced. Eventually, the advantages of the technique to simulate the microwave heating process in crude oils are presented. Manuscript profile -
Open Access Article
4 - Letter to Sound Conversion for Persian Language Using Multi Layer Perceptrons
M. Namnabat M. M. HomayounpourConstruction of letter to sound (LTS) conversion systems in Persian is a difficult task. Because of the omission of some vowels in Farsi orthography, these systems in general have low efficiencies. In this paper, the structure of a letter to sound system, having three-l MoreConstruction of letter to sound (LTS) conversion systems in Persian is a difficult task. Because of the omission of some vowels in Farsi orthography, these systems in general have low efficiencies. In this paper, the structure of a letter to sound system, having three-layer architecture, was presented. The first layer is rule-based, and the second layer consists of five multi layer perceptron (MLP) neural networks and a controller section for pronunciations determination. The third layer has a MLP network for detection of geminated letters by using results obtained from the previous steps. The proposed system is designed to produce rational pronunciations for every word, where the rational pronunciation means a phonetic transcription, which follows the correct Farsi syllabification structure and the obvious rules of phonetics. The authors have achieved 88% and 61% correct letters and words performance respectively, which is quite satisfactory for a Farsi language LTS system. The correct letter criterion is the percentage of letters for which the pronunciations have been determined correctly and the correct word criterion is the percentage of words for which the pronunciations of the constituting letters have been determined correctly. Manuscript profile -
Open Access Article
5 - Performance Analysis of DFT block code in the Presence of Quantization Noise over Fading Channel
P. AzmiError control codes are among the most useful methods for mitigating the effect of fading and channel noise. Most of researches on error control codes are focused on the codes defined over finite (Galois) fields. In this paper, we consider DFT code defined over infinite MoreError control codes are among the most useful methods for mitigating the effect of fading and channel noise. Most of researches on error control codes are focused on the codes defined over finite (Galois) fields. In this paper, we consider DFT code defined over infinite Real field. We will analysis the performance of DFT code in the presence of quantization noise over fading channel. Our simulation results show that this code can efficiently suppress the effect of fading and channel noise. It will be shown that DFT code outperforms the well-known Reed Solomon code in low signal to noise ratio ranges. Manuscript profile -
Open Access Article
6 - An Exact Analytical Method for Performance Analysis of Maximal-Ratio and Equal-Gain Combining Diversity Schemes over Rayleigh Fading Channels in the Presence of Gaussian Channel Estimation Error
H. Samimi P. AzmiIn this paper, the probability of error of maximal-ratio combining (MRC) and equal-gain combining (EGC) diversity schemes with coherent binary phase shift keying (BPSK) is analyzed over Rayleigh fading channels in the presence of channel estimation error. The channel es MoreIn this paper, the probability of error of maximal-ratio combining (MRC) and equal-gain combining (EGC) diversity schemes with coherent binary phase shift keying (BPSK) is analyzed over Rayleigh fading channels in the presence of channel estimation error. The channel estimation errors cause errors in the required weighting coefficients of the diversity receivers. Such errors are generally modeled as complex Gaussian random variables. Based on this assumption, we develop novel exact analytical equations for the calculation of the probability of error in the presence of Gaussian errors in the weighting coefficients. Results show that the exact probability of error can be derived using the existing equations under the assumption of perfect channel estimation and by replacing the SNR with an effective SNR, which is due to the weighting coefficients errors. Manuscript profile -
Open Access Article
7 - Design and Implementation of a Circularly Polarized Microstrip Patch Antenna for GPS Application with Input VSWR Tuning Capability
A. A. HeidariIn this paper theoretical and experimental investigation of a right hand circularly polarized microstrip rectangular patch antenna have been presented. The antenna has a coaxial feed and designed for operating at L1 frequency (1575 MHz) of global positioning systems (GP MoreIn this paper theoretical and experimental investigation of a right hand circularly polarized microstrip rectangular patch antenna have been presented. The antenna has a coaxial feed and designed for operating at L1 frequency (1575 MHz) of global positioning systems (GPS). The antenna have been simulated and optimized using the HP-HFSS software in combination with Empipe3D. The inherently narrow bandwidth of the antenna was increased to 70 MHz using an air layer. A useful practical method was proposed in order to minimizing the input VSWR of the antenna. Theoretical and measured results have been presented and compared. Manuscript profile -
Open Access Article
8 - Investigation of New Structures for Carbon Nanotube FETs
R. Faez S. E. HosseiniA carbon nanotube field effect transistor (CNTFET) with Schottky contacts for the drain and the source has been investigated. It is shown that the saturation region of the transistor output characteristics is small. This limits the application of the transistor. To impr MoreA carbon nanotube field effect transistor (CNTFET) with Schottky contacts for the drain and the source has been investigated. It is shown that the saturation region of the transistor output characteristics is small. This limits the application of the transistor. To improve the saturation range in the output characteristics, new structures are proposed, and the simulation results are compared. The proposed structures have supperior output characteristics. Manuscript profile -
Open Access Article
9 - Design of a Low-Pass Switched Capacitor Fourth Order Chebyshev Filter Using an Improved Auto Zero Integrator
Mohammad Rashtian O. Hashemipour K. NaviIn this work the low-voltage high-speed auto zeroed integrator characteristics is improved by utilizing the non-linear properties of switches. Based on this improvement a newly designed structure for a low-pass filter is presented. The designed filter is a fourth order MoreIn this work the low-voltage high-speed auto zeroed integrator characteristics is improved by utilizing the non-linear properties of switches. Based on this improvement a newly designed structure for a low-pass filter is presented. The designed filter is a fourth order Chebyshev with pass band frequency of 500 KHz and sampling frequency of 5 MHz. Based on this method a fast and accurate sample and hold structure is introduced. The designed work is simulated using 0.25µm CMOS technology at 1.2 V supply voltage. Manuscript profile