Threshold

Open Access Article

1 - A New Method for Detecting the Number of Coherent Sources in the Presence of Colored Noise
Shahriar Shirvani Moghaddam Somaye Jalaei

10.7508/jist.2013.03.007

In this paper, a new method for determining the number of coherent/correlated signals in the presence of colored noise is proposed which is based on the Eigen Increment Threshold (EIT) method. First, we present a new approach which combines EIT criterion and eigenvalue More

In this paper, a new method for determining the number of coherent/correlated signals in the presence of colored noise is proposed which is based on the Eigen Increment Threshold (EIT) method. First, we present a new approach which combines EIT criterion and eigenvalue correction. The simulation results show that the new method estimates the number of noncoherent signals in the presence of colored noise with higher detection probability respect to MDL, AIC, EGM and conventional EIT. In addition, to apply the proposed EIT algorithm to detect the number of sources in the case of coherent and/or correlated sources, a spatial smoothing preprocessing is added. In this case, simulation results show 100% detection probability for signal to noise ratios greater than -5dB. Final version of the proposed EIT-based method is a simple and efficient way to increase the detection probability of EIT method in the presence of colored noise considering either coherent/correlated or noncoherent sources. Manuscript profile

Open Access Article

2 - An Improved Method for TOA Estimation in TH-UWB System considering Multipath Effects and Interference
Mahdieh Ghasemlou Saeid Nader Esfahani Vahid Tabataba Vakili

10.7508/jist.2014.01.003

UWB ranging is usually based on the time-of-arrival (TOA) estimation of the first path. There are two major challenges in TOA estimation. One challenge is to deal with multipath channel, especially in indoor environments. The other challenge is the existence of interfer More

UWB ranging is usually based on the time-of-arrival (TOA) estimation of the first path. There are two major challenges in TOA estimation. One challenge is to deal with multipath channel, especially in indoor environments. The other challenge is the existence of interference from other sources. In this paper, we propose a new method of TOA estimation, which is very robust against the interference. In this method, during the phase of TOA estimation, the transmitter sends its pulses in random positions within the frame. This makes the position of the interference relative to the main pulse to be random. Consequently, the energy of interference would be distributed, almost uniformly, along the frame. In energy detection methodes, a constant interference along the frame does not affect the detection of arrival time and only needs the adjustment of the threshold. Simulation results in IEEE.802.15.4a channels show that, even in presence of very strong interference, TOA estimation error of less than 3 nanoseconds is feasible with the proposed method. Manuscript profile

Open Access Article

3 - Retinal Vessel Extraction Using Dynamic Threshold And Enhancement Image Filter From Retina Fundus
erwin erwin Tomi Kiyatmoko

10.7508/jist.2018.04.001

In the diagnosis of retinal disease, Retinal vessels become an important role in determining certain diseases. Retina vessels are an important element with a variety of shapes and sizes, each human blood vessel also can determine the disease with various types, but the More

In the diagnosis of retinal disease, Retinal vessels become an important role in determining certain diseases. Retina vessels are an important element with a variety of shapes and sizes, each human blood vessel also can determine the disease with various types, but the feasibility of the pattern of retinal blood vessels is very important for the advanced diagnosis process in medical retina such as detection, identification and classification. Improvement and improvement of image quality in this case is very important by focusing on extracting or segmenting the retinal veins so that parameters such as accuracy, specifications, and sensitivity can be obtained that are better and meet the advanced system. Therefore we conducted experiments in order to develop extraction of retinal images to obtain binary images of retinal vessels in the medical world using Dynamic Threshold and Butterworth Bandpass Filter. Using a database DRIVE Accuracy of 94.77%, sensitivity of 54.48% and specificity of 98.71%. Manuscript profile

Open Access Article

4 - An Automatic Thresholding Approach to Gravitation-Based Edge Detection in Grey-Scale Images
Hamed Agahi Kimia Rezaei

10.52547/jist.9.36.285

This paper presents an optimal auto-thresholding approach for the gravitational edge detection method in grey-scale images. The goal of this approach is to enhance the performance measures of the edge detector in clean and noisy conditions. To this aim, an optimal thres More

This paper presents an optimal auto-thresholding approach for the gravitational edge detection method in grey-scale images. The goal of this approach is to enhance the performance measures of the edge detector in clean and noisy conditions. To this aim, an optimal threshold is automatically found, according to which the proposed method dichotomizes the pixels to the edges and non-edges. First, some pre-processing operations are applied to the image. Then, the vector sum of the gravitational forces applied to each pixel by its neighbors is computed according to the universal law of gravitation. Afterwards, the force magnitude is mapped to a new characteristic called the force feature. Following this, the histogram representation of this feature is determined, for which an optimal threshold is aimed to be discovered. Three thresholding techniques are proposed, two of which contain iterative processes. The parameters of the formulation used in these techniques are adjusted by means of the metaheuristic grasshopper optimization algorithm. To evaluate the proposed system, two standard databases were used and multiple qualitative and quantitative measures were utilized. The results confirmed that the methodology of our work outperformed some conventional and recent detectors, achieving the average precision of 0.894 on the BSDS500 dataset. Moreover, the outputs had high similarity to the ideal edge maps. Manuscript profile

Open Access Article

5 - A Threshold-based Brain Tumour Segmentation from MR Images using Multi-Objective Particle Swarm Optimization
Katkoori Arun Kumar Ravi Boda

10.52547/jist.9.36.218

The Pareto optimal solution is unique in single objective Particle Swarm Optimization (SO-PSO) problems as the emphasis is on the variable space of the decision. A multi-objective-based optimization technique called Multi-Objective Particle Swarm Optimization (MO-PSO) i More

The Pareto optimal solution is unique in single objective Particle Swarm Optimization (SO-PSO) problems as the emphasis is on the variable space of the decision. A multi-objective-based optimization technique called Multi-Objective Particle Swarm Optimization (MO-PSO) is introduced in this paper for image segmentation. The multi-objective Particle Swarm Optimization (MO-PSO) technique extends the principle of optimization by facilitating simultaneous optimization of single objectives. It is used in solving various image processing problems like image segmentation, image enhancement, etc. This technique is used to detect the tumour of the human brain on MR images. To get the threshold, the suggested algorithm uses two fitness(objective) functions- Image entropy and Image variance. These two objective functions are distinct from each other and are simultaneously optimized to create a sequence of pareto-optimal solutions. The global best (Gbest) obtained from MO-PSO is treated as threshold. The MO-PSO technique tested on various MRI images provides its efficiency with experimental findings. In terms of “best, worst, mean, median, standard deviation” parameters, the MO-PSO technique is also contrasted with the existing Single-objective PSO (SO-PSO) technique. Experimental results show that Multi Objective-PSO is 28% advanced than SO-PSO for ‘best’ parameter with reference to image entropy function and 92% accuracy than Single Objective-PSO with reference to image variance function. Manuscript profile

Open Access Article

6 - Philosophy and Religious law in Spinoza’s Theologico-Political Treatise: Admist Averroism and Textualism
Reza Najafzadeh

Given the Multi-cultural nature of the development of philosophical systems, it can be claimed that Baruch Benedict de Spinoza formulated his view of the problem of the possibility or impossibility of concurrence of philosophy and religion in line with the tradition of More

Given the Multi-cultural nature of the development of philosophical systems, it can be claimed that Baruch Benedict de Spinoza formulated his view of the problem of the possibility or impossibility of concurrence of philosophy and religion in line with the tradition of Latin and Jewish Averroists. A major part of his Theologico-Political Treatise is devoted to responding to this problem. Spinoza’s philosophical thoughts were influenced by several philosophical and political traditions. Inspired by the naturalist philosophers of the Renaissance period, he advocated the radical republican tradition and played a significant role in developing the radical Enlightenment heritage. In unity with such trends and while being influenced by the Protestant religious reforms tradition and having a Jewish educational background, Spinoza was continually occupied with the important problem of the possibility or impossibility of reconciling theology and philosophy or religion and rationality. This radical philosopher of the Enlightenment Period encountered holy texts in the light of the Islamic and Jewish legacies of rational thoughts. In order to provide an answer to this problem, he openly dealt with the rationalist and textualist trends of Judaism. Given the huge contribution of Islamic rational thoughts to the rise of the Middle Age Jewish philosophy, his thoughts also dragged him to the domain of Islamic rational philosophy. In comparison to Muslim and Jewish textualists and rationalists of the Middle Ages, he chose the middle way and defended the reasons for his choice in the theological parts of his Theologico- Political Treatise: he argued that neither is philosophy at the service of religion, nor is religion at the service of philosophy. Based on this Spinozist idea, two hypotheses can be postulated: 1) the impossibility of the unity of philosophy and religion in Theologico-Political Treatise does not necessarily indicate providing some secular principles for the public domain; 2) following the historical hermeneutic approach to holy texts, this treatise provides a fideist theory which frees the vast field of living in the modern world from meaningless sterility and coldness. Manuscript profile

Open Access Article

7 - A New Approximate Analytical Method for Performance Analysis of Regular LDPC Codes Iterative Decoding on AWGN Channels
H. Samimi P. Azmi Mohammad hakak

In this paper we propose a new Gaussian-based analytical method for performance analysis of regular LDPC codes iterative decoding on AWGN channel. The proposed method has good accuracy and low complexity in comparison with current methods. Based on our developed analyti More

In this paper we propose a new Gaussian-based analytical method for performance analysis of regular LDPC codes iterative decoding on AWGN channel. The proposed method has good accuracy and low complexity in comparison with current methods. Based on our developed analytical equations, we present an error propagation model for the iterative decoder of LDPC codes which can be used as a simple tool for convergence analysis of LDPC codes on the AWGN channel. Manuscript profile

Open Access Article

8 - An Adaptive Wavelet-Based Signal Denoising Schem
M. nasri H. Nezamabadi-pour S. Saryazdi

In this paper, a new class of nonlinear thresholding functions with a tunable shape parameter for wavelet-based signal denoising is presented. In addition, a new learning technique for training of thresholding neural network is introduced. Unlike to existing methods, bo More

In this paper, a new class of nonlinear thresholding functions with a tunable shape parameter for wavelet-based signal denoising is presented. In addition, a new learning technique for training of thresholding neural network is introduced. Unlike to existing methods, both the shape and the threshold parameters are tuned simultaneously using LMS rule. This permits us to consider the effects of both the threshold and the shape parameters on denoising. The proposed functions are tested in both universal-threshold and subband-adaptive denoising and compared with conventional functions. In addition, to evaluate the proposed training method, several numerical examples are performed. The experimental results obtained from denoising of several standard benchmark signals confirm the efficiency and effectiveness of the proposed methods. Manuscript profile

Open Access Article

9 - Adaptive Wavelet Thresholding for Denoising Speech Signals
F. sheikhalishahi H. R. abutalebi M. R. Taban

This paper addresses the problem of speech enhancement in wavelet domain. After decomposition of noisy signal into wavelet sub-bands, an adaptive thresholding process is applied on wavelet coefficients. In the proposed technique, small threshold value and hard thrsholdi More

This paper addresses the problem of speech enhancement in wavelet domain. After decomposition of noisy signal into wavelet sub-bands, an adaptive thresholding process is applied on wavelet coefficients. In the proposed technique, small threshold value and hard thrsholding function are used in sub-bands with high speech energy; vice versa, in sub-bands with low speech energy, large threshold value and soft thresholding function are employed. For other sub-bands (between above two extreme cases for speech energy), we use an adaptive thresholding function that is actually between soft- and hard-thresholding functions. The threshold value and thresholding function are determined by a parameter related to the ratio of speech and noise powers in each sub-band. Our extensive experiments show the superiority of proposed method in removing the background noise and reduction of speech distortion. It was also shown that both wavelet tree structure and wavelet type affect on the performance of speech de-noising system. Manuscript profile

Open Access Article

10 - A Contrast Independent Algorithm for Binarization of Document Images
M. Valizadeh E. Kabir

In this paper, we present a contrast independent algorithm for binarization of degraded document images. The proposed algorithm does not require any parameter setting by user. Therefore, it can handle document images with variable foreground and background intensities a More

In this paper, we present a contrast independent algorithm for binarization of degraded document images. The proposed algorithm does not require any parameter setting by user. Therefore, it can handle document images with variable foreground and background intensities and low contrast documents. The proposed algorithm involves three consecutive stages. At the first stage, independent of contrast between foreground and background, sensible parts of each character are extracted using the modified water flow model, which is designed for the extraction of sensible part of each character and the drawbacks of water flow model are solved in this algorithm. In the second stage, the gray levels of foreground are estimated using the extracted text pixels and the gray levels of background are locally estimated by averaging the original image. At the third stage, for each pixel of image, the average of estimated foreground and background gray levels is defined as local threshold. After extensive experiments, the proposed binarization algorithm demonstrates superior performance against conventional binarization algorithms on a set of degraded document images captured with camera. Proposed algorithm efficiently extracts the low contrast texts. Manuscript profile

Open Access Article

11 - Detection of Shaded Areas Boundary in Intravascular Ultrasound Images Using Active Contour
M. Basij M. Yazdchi P. Moallem A. Taki

Intra vascular imaging is used for extracting more accurate information about the size and characteristics of plaques than coronary angiography. Sometimes shadows appear behind the calcification plaques that it makes some problem to process these images automatically. T More

Intra vascular imaging is used for extracting more accurate information about the size and characteristics of plaques than coronary angiography. Sometimes shadows appear behind the calcification plaques that it makes some problem to process these images automatically. This paper describes a new approach for shadows region and border detection in Intra Vascular Ultrasound images. In the proposed algorithm, Otsu thresholding is utilized for identification of shadows location and the Active contours without edge is used for shadows border detection. According to experiments conducted on 30 samples, this proposed algorithm can able to detect shadow regions correctly with sensitivity of 86%. Manuscript profile

Open Access Article

12 - Human Recognition via Finger Vein Images in Radon Space Using Common Spatial Patterns
H. Hassanpour A. Gholami

One of the most fitting biometric for identifying individuals is finger veins. In this paper, we study the human recognition via finger vein images that recognize persons at a high level of accuracy. First we use entropy based thresholding for segmentation and extractio More

One of the most fitting biometric for identifying individuals is finger veins. In this paper, we study the human recognition via finger vein images that recognize persons at a high level of accuracy. First we use entropy based thresholding for segmentation and extraction veins from finger vein images. The method extract veins as well, but the images are very noisy. That means in addition to the veins that appeared as dark lines, they have some Intersecting lines. Then we applied radon transformation to segmented images. The radon transform is not sensitive to the noise in the images due to its integral nature, so in comparison with other methods is more resistant to noise. This transform does not require the extraction of vein lines accurately, that can help to increase accuracy and speed. Then for extracting features from finger vein images, common spatial patterns are applied to the blocks of Radon Transform. In identification step two methods are used: Nearest Neighbor (1-NN) and Artificial Neural Network (MLP). Experiments conducted on sets of finger vein image database of Peking University show 99.6753 percent success rate in identifying individuals. Manuscript profile

Open Access Article

13 - Reducing OFF-State Current in Nano-Scale Double Gate Junctionless Field Effect Transistor (DGJL-FET) Using Doping Engineering of Channel Region
S. Kalantari M. Vadizadeh

Scaling the channel length leads to the increased leakage current of double gate junctionless field effect transistor (DGJL-FET) and, as a result, the increased power consumption in OFF-state. The present paper proposes a new structure for reducing the leakage current i More

Scaling the channel length leads to the increased leakage current of double gate junctionless field effect transistor (DGJL-FET) and, as a result, the increased power consumption in OFF-state. The present paper proposes a new structure for reducing the leakage current in DGJL-FET, which is called modified DGJL-FET. In this structure, the channel doping under the gate is the same as the drain and source doping but higher than the mid-channel doping. The simulation results indicated that reducing the thickness of the doped layer under the gate, D, resulted in the reduced OFF-state current. For the proposed device with 10 nm channel length, the OFF-state current is less than that in the regular DGJL-FET by two orders of magnitude. Performance of the regular DGJL-FET and modified DGL-FET for different channel lengths is compared based on the IOFF/ION ratio, sub-threshold slope (SS), and intrinsic gate delay. For modified DGJL-FET, the mid-channel doping and Dare considered as additional parameters for improving the device’s performance in nanometer regime. The simulation results indicated that in the proposed device with channel length of 15 nm, values of SS and IOFF/ION ratio are improved compared to the regular DGJL-FET by 14% and 106 orders of magnitude, respectively. Manuscript profile

Open Access Article

14 - Analysis and Design of a Low Power Analog to Digital Converter Using Carbon Nano-Tube Field Effect Transistors
Saeedeh Heidari D. Dideban

Nowadays, analog to digital (A/D) converters are indistinguishable parts of system on chip (soC) structures because they omit the distance between analog real data and digital logic world. Due to this fact and ever increasing trend for using portable instruments, the fi More

Nowadays, analog to digital (A/D) converters are indistinguishable parts of system on chip (soC) structures because they omit the distance between analog real data and digital logic world. Due to this fact and ever increasing trend for using portable instruments, the figures of merit for design of these converters such as speed, power and occupied area are improved. Different methods are proposed to improve the performance of these converters. In this paper, we design a fast and low power ADC using carbon nano-tube field effect transistor (CNTFET) and then its performance is comprehensively compared with a MOSFET based counterpart at the same technology node. The performance is studied two encoders: ROM and Fat tree. The obtained results are presented using HSPICE simulator at 0.9 V power supply. The simulated data from CNTFET based converter shows significant improvements in delay and power compared with its CMOS based counterpart. The power and delay obtained from CNTFET based converter using ROM encoder are improved by 92.5% and 54% with respect to the same parameters obtained from CMOS based design while the improvements using a Fat tree encoder in CNTFET converter reaches 93% and 72% in comparison with CMOS conventional design. Manuscript profile

Open Access Article

15 - Design and Simulation of a Lable-Free Nano Biosensor for Detecting Molecules via Nanotube Junctionless Field Effect Transistor
Zahra Ahangari

Biosensors have various applications especially in medical diagnosis. In this paper, nanotube junctionless transistor is employed for label-free detection of biomolecules. The proposed device works based on dielectric modulated principle. In this transistor, the gate vo More

Biosensors have various applications especially in medical diagnosis. In this paper, nanotube junctionless transistor is employed for label-free detection of biomolecules. The proposed device works based on dielectric modulated principle. In this transistor, the gate voltage is responsible for controlling the drain current and in case of gate capacitance variation, the drain current can be modulated. A nanogap is embedded in the gate insulator region for immobilization of biomolecules. Since each individual biomolecule has its specific dielectric constant, the accumulation of different biomolecule in the nanogap changes the dielectric constant of the nanogap, which eventually leads to the variation of gate capacitance and the drain current. Threshold voltage variation and drain current modulation are considered as two measures for detecting biomolecules and determining the biosensor’s sensitivity. The proposed device has two internal and external gates with low static power consumption as well as simpler low temperature fabrication process. One of the main advantages of the proposed device is its high selectivity and sensitivity, especially for biomolecules with low dielectric constant. Impact of critical physical and structural design parameters on the operation of the biosensor are thoroughly investigated. Gate workfunction and channel doping density are two critical parameters that affect the sensitivity of the biosensor and as a consequence, optimum values should be determined for them. Due to the low power consumption and high sensitivity, this sensor can be considered as a potential candidate for applications in nanoscale regime. Manuscript profile

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