فهرست مطالب

Advances in Computer Research - Volume:10 Issue:1, 2018
  • Volume:10 Issue:1, 2018
  • تاریخ انتشار: 1397/08/28
  • تعداد عناوین: 7
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  • High Performance Implementation of Fuzzy C-Means and Watershed Algorithms for MRI Segmentation
    Farnaz Hoseini *, Ghader Mortezaie Dekahi Pages 1-10
    Image segmentation is one of the most common steps in digital image processing. The area many image segmentation algorithms (e.g., thresholding, edge detection, and region growing) employed for classifying a digital image into different segments. In this connection, finding a suitable algorithm for medical image segmentation is a challenging task due to mainly the noise, low contrast, and steep light variations of medical images. Due to the inherently parallel nature of image segmentation algorithms, they suit well for implementation on a Graphics Processing Unit (GPU). The main goal of this paper is to improve the performance of fuzzy c-means clustering through the parallel implementation of this algorithm. Although fuzzy c-means clustering is an important iterative clustering algorithm, it is computationally intensive and uses the same data between the iterations. The center of the clusters changes in each iteration, which requires a considerable amount of time for large data sets. The parallel fuzzy c-means clustering is implemented by applying pipeline parallelism on GPU. The experimental results show that the performance is improved up to 23.35x. Next, the watershed algorithm is applied to the final segmentation. In this paper using parallel fuzzy c-means clustering and computations we have attained competing results with other papers. The implementation results on the BRATS2015 show that the accuracy of diagnosis in Dice Similarity Coefficient metric 97/33% is obtained. This improvement is achieved using enhancing edges and reducing noises in images.
    Keywords: Parallel Fuzzy C-Means Clustering, Watershed Algorithm, FCM, CUDA, GPU
  • Solving Data Clustering Problems using Chaos Embedded Cat Swarm Optimization
    Farhad Ramezani * Page 2
    In this paper, a new method is proposed for solving the data clustering problem using Cat Swarm Optimization (CSO) algorithm based on chaotic behavior. The problem of data clustering is an important section in the field of the data mining, which has always been noted by researchers and experts in data mining for its numerous applications in solving real-world problems. The CSO algorithm is one of the latest meta-heuristic algorithms, which has a simple structure and it is easy to implement. The purpose of Chaos embedded Cat Swarm Optimization (CCSO) algorithm is to replace random values by chaotic ones to offer a stable algorithm that can allow for reaching the global optima to a large extent and improve the algorithm’s convergence speed. The proposed algorithm has been compared to other heuristic algorithms on standard data sets from UCI repository, and the experimental results demonstrate that the proposed algorithm yields high performance for solving the data clustering problem.
    Keywords: Data clustering, K-means, Cat Swarm Optimization, Chaos theory.
  • Determination of a new model to study ultra-saturation phenomenon during the loaded power transformer energization and its effect on differential protection
    Bahram Noshad * Page 3
    One of transient phenomenon that causes the mal-operation of the power transformer differential protection during the energization of a loaded power transformer is the ultra-saturation phenomenon. In this paper, a new model for investigating the ultra-saturation phenomenon during the energization of a loaded power transformer is presented and its effect on the differential protection of the power transformer is considered. In this model, the nonlinear characteristic of the power transformer core, the effect of current transformers, and the core losses of the power transformer are taken into account. It is assumed that the load of the power transformer is a resistive and inductive load. Also, the effect of the residual flux and inception angle on the ultra-saturation phenomenon are investigated. In this paper, simulation is done by MATLAB software. The differential protection of the power transformer must be accurate and fast, so the description of the ultra-saturation phenomena is the first level for preventing of the mal-operation of the differential protection. The outcomes of this research can further be used as hints for substation operation personnel as well as for the development of new protection stabilization criteria, which is not discussed further in this paper.
    Keywords: power transformer, differential protection, inrush current, ultra-saturation phenomenon, false trip
  • Accessibility Evaluation in Biometric Hybrid Architecture for Protecting Social Networks Using Colored Petri Nets
    Navid Rafizadeh Shotorbani Fard, Hasan Hosseinzadeh*, Masoud Bekravi Page 4
    In the last few decades, technological progress has been made important information systems that require high security, Use safe and efficient methods for protecting their privacy. It is a major challenge to Protecting vital data and the ability to threaten attackers. And this has made it important and necessary to be sensitive to the authentication and identify of individuals in confidential network systems. In this paper, a method is presented for protecting privacy in social networks with a hybrid biometric architecture. In the proposed method, was used to the combination of biometric indexes of fingerprints and iris effect to maintain confidentiality in user access and authentication. Also, to demonstrate the availability of the method, an accurate evaluation is made by creating a model that is implemented with the help of integrated modeling language and colored petri nets with strong mathematical backing. The results indicate improved access and privacy with high confidentiality
    Keywords: Authenticated, Availability, Biometric component, Colored petri nets, Integrated modeling language
  • Non-Blocking Routers Design Based on West First Routing Algorithm & MZI Switches for Photonic NoC
    Masoume Seifolahi, Elham Yaghoubi * Page 5
    For the first time, the 4- and 5-port optical routers are designed by using the West First routing algorithm for use in optical network on chip. The use of the WF algorithm has made the designed routers to provide non-blocking routing in photonic network on chip. These routers not only are based on high speed Mach-Zehnder switches(Which have a higher bandwidth and more thermal tolerance than microring resonator switches), but also are more flexible than the XY algorithm based routers. these routers are capable of routing with the speed of 20 Gb/s. In the design of the routers, the least number of switching elements and waveguide crossings has improved the optical network on chip evaluation parameters. The results of the simulation show that all of the evaluation parameters such as: insertion loss, bit error ratio(BER), power budget, quality factor and eye diagrams are in an acceptable range, and the proposed routers are appropriate for use in optical network on chip.
    Keywords: Mach-Zehnder interferometer, optical router, photonic network on chip, West First routing algorithm
  • Fast Intra Mode Decision for Depth Map coding in 3D-HEVC Standard
    Behrouz Rafi, Mohammadreza Ramezanpour * Page 6
    three dimensional- high efficiency video coding (3D-HEVC) is the expanded version of the latest video compression standard, namely high efficiency video coding (HEVC), which is used to compress 3D videos. 3D videos include texture video and depth map. Since the statistical characteristics of depth maps are different from those of texture videos, new tools have been added to the HEVC standard for intra coding. Thirty-five intra prediction modes with the recursive block partitioning structure in HEVC and the depth modeling modes improve the intra coding efficiency while increase the computational complexity. This Standard achieves the highest possible coding efficiency compared with predecessor standards, while increases the computational complexity that makes the 3D-HEVC cannot be suitable for real-time applications. In this paper, a fast intra prediction mode decision method is proposed to code depth map for 3D videos. Since the texture of video and the corresponding depth map represent the same scene, there is a high correlation between the prediction mode of texture video and its depth map. Thus, we can skip some depth map intra prediction modes rarely used in the related texture coding unit. The simulation results show that the proposed method reduces computational complexity by 23.66% compared to 3D-HEVC standard with an increase of 0.09% bit rate
    Keywords: video compression, intra-prediction, depth-map
  • A New Design for Two-input XOR Gate in Quantum-dot Cellular Automata
    Hossein Khademolhosseini* , Yaser Nemati Page 7
    Quantum-dot Cellular Automata (QCA) technology is attractive due to its low power consumption, fast speed and small dimension, therefore, it is a promising alternative to CMOS technology. In QCA, configuration of charges plays the role which is played by current in CMOS. This replacement provides the significant advantages. Additionally, exclusive-or (XOR) gate is a useful building block in many important circuits such as full adder (FA). In this paper we propose a novel design for two-input XOR gate in QCA. Two-input XORs could be utilized in constructing three-input ones which are widely used. The proposed XOR gate is the smallest design among the two-input XORs and it achieves significant improvements in terms of complexity and latency in comparison to the only existing similarly designed gate. Contrary to the common designing method which uses the logic function of XOR, the gate is constructed based on explicit interactions between QCA cells. The simulation results have been verified using the QCADesigner.
    Keywords: Quantum-Dot Cellular Automata (QCA), Nanotechnology, Circuit Design, XOR gate, Circuit Simulation