• XML

    isc pubmed crossref medra doaj doaj
  • List of Articles


      • Open Access Article

        1 - A Machine Learning Approach to No-Reference Objective Video Quality Assessment for High Definition Resources
        ناصر فرج زاده ملیحه مظلومی
        The video quality assessment must be adapted to the human visual system, which is why researchers have performed subjective viewing experiments in order to obtain the conditions of encoding of video systems to provide the best quality to the user. The objective of this More
        The video quality assessment must be adapted to the human visual system, which is why researchers have performed subjective viewing experiments in order to obtain the conditions of encoding of video systems to provide the best quality to the user. The objective of this study is to assess the video quality using image features extraction without using reference video. RMSE values and processing time of SVR for BMP and JPEG formats in quality assessment were 0.78×10-2, 0.81×10-2, 6.0s and 4.8s, respectively. In this study, a metric system for no-reference assessing the video quality is presented using wavelet transform and generalized Gaussian distribution parameters. Results of ITU-BT tests for each video were used to train SVR and its performance for video frames is evaluated Manuscript profile
      • Open Access Article

        2 - Analysis of Multi-Robots Transportation with Multi-objective PSO Algorithm in an Artificial Capital Market
        داود آشیانی سعید حسین سعادتی عبدالرضا صدیق منش
        In this paper, to analyze the transport of autonomous robots, an artificial Capital market is used. Capital market is considered as a pier which loading and unloading of cargo is done. Autonomous robots load and unload from the ship to the warehouse wharf or vice versa. More
        In this paper, to analyze the transport of autonomous robots, an artificial Capital market is used. Capital market is considered as a pier which loading and unloading of cargo is done. Autonomous robots load and unload from the ship to the warehouse wharf or vice versa. All the robots have the ability of transporting the loads, but depending on loads and the location of unloading (or loading) and position of robots, robots have different role in unloading tasks. The role of robots and their number is decided, planned, and managed by the partial swarm optimization (PSO) algorithm. The main goal of the paper is to optimize a multi-object function (MOF) which is a combination of total work time and fuel cost functions. In this paper, a new method of transporting from ships to warehouses and vice versa was developed and presented considering the cost of fuel and the shortest possible time. Manuscript profile
      • Open Access Article

        3 - Application of Non-Linear Functions at Distribution of Output SINR Gaussian Interference Channels
        توحید صاذقی شاهین شافعی
        We have examined the convergence behavior of the LSCMA in some simple environments. Algorithms such as Multi¬ Target CMA, Multistage CMA, and Iterative Least Squares with Projection can be used for this purpose. The results presented here can form a basis for analys More
        We have examined the convergence behavior of the LSCMA in some simple environments. Algorithms such as Multi¬ Target CMA, Multistage CMA, and Iterative Least Squares with Projection can be used for this purpose. The results presented here can form a basis for analysis of these multi-signal extraction techniques. Clearly, the variance and distribution of output SINR obtained with the LSCMA is also an important area for investigation. We finally comment on the hard-limit non-linearity. For high SIR, the hard-limiter is the optimal non-linearity when the desired signal has a constant envelope. However, at low SIR other non-linearities can yield greater SIR gain. Thus, it is possible that non-linear functions other than the hard-limit can be used to develop blind adaptive algorithms, which converge faster for low initial SINR. Manuscript profile
      • Open Access Article

        4 - Using Program Slicing Technique to Reduce the Cost of Software Testing
        اصغر محمدیان بهمن آراسته
        Systems of computers and their application in the lives of modern human beings are vastly expanding. In any kind of computer application, failure in computer systems can lead to a range of financial and mortal losses. Indeed, the major origin of software failure can be More
        Systems of computers and their application in the lives of modern human beings are vastly expanding. In any kind of computer application, failure in computer systems can lead to a range of financial and mortal losses. Indeed, the major origin of software failure can be located in designing or implementing software. With regard to these statistics, 30% of the software projects have been prosperous and successful. The proposed method is intended to reduce the cost and time of testing and it focuses on enhancing the efficiency of software testing methods. In this paper, we investigated the effect of slicing techniques on the reduction rate of testing cost and time. The results of experiments show that we can cover a large number of program instructions, branches and paths by a small number of test cases in the sliced program Manuscript profile
      • Open Access Article

        5 - Electronical and Mechanical System Modeling of Robot Dynamics Using a Mass/Pulley Model
        عطالله رجب پور امیر زارعی آرزو رجب پور فاطمه احمدی
        The well-known electro-mechanical analogy that equates current, voltage, resistance, inductance and capacitance to force, velocity, damping, spring constant and mass has a shortcoming in that mass can only be used to simulate a capacitor which has one terminal connected More
        The well-known electro-mechanical analogy that equates current, voltage, resistance, inductance and capacitance to force, velocity, damping, spring constant and mass has a shortcoming in that mass can only be used to simulate a capacitor which has one terminal connected to ground. A new model that was previously proposed by the authors that combines a mass with a pulley (MP) is shown to simulate a capacitor in the general case. This new MP model is used to model the off-diagonal elements of a mass matrix so that devices whose effective mass is coupled between more than one actuator can be represented by a mechanical system diagram that is topographically parallel to its equivalent electric circuit model. Specific examples of this technique are presented to demonstrate how a mechanical model can be derived for both a serial and a parallel robot with both two and three degrees of freedom. The technique, however, is extensible to any number of degrees of freedom Manuscript profile
      • Open Access Article

        6 - The New Design and Simulation of an Optical Add Drop Filter Based On Hexagonal Photonic Crystal Single Ring Race Track Resonator
        ابولفضل عباسپور حامد علیپور بنایی علیرضا عندلیب
        In this paper, using annular resonator we have designed an adding and dropping filter light based ontwo-dimensional photonic crystals. The shape of ring resonator filter adding and dropping that wehave proposed is Race Track. This filter has a hexagonal lattice structur More
        In this paper, using annular resonator we have designed an adding and dropping filter light based ontwo-dimensional photonic crystals. The shape of ring resonator filter adding and dropping that wehave proposed is Race Track. This filter has a hexagonal lattice structure of silicon bars withrefractive index 3/46 that is located in the context of air with refractive index 1. Transmissionefficiency and quality coefficient of our proposed filter are respectively 94% and 310. Finite differencemethod in two-dimensional time domain (2-D FDTD) used for normalized transmission spectra ofphotonic crystal ring resonator and to calculate the photonic band, plane wave expansion method(PWE) has been used. Manuscript profile
      • Open Access Article

        7 - Optical Filter Based On Point Defects in 2D Photonic Crystal Structur
        آرزو مالکی
        In this paper, we proposed a novel structure for designing all optical filter based on photonic crystal structure. In designing the proposed filter, we simply employed a point defect localized between input and output waveguides as wavelength selecting part of the filte More
        In this paper, we proposed a novel structure for designing all optical filter based on photonic crystal structure. In designing the proposed filter, we simply employed a point defect localized between input and output waveguides as wavelength selecting part of the filter. The initial form of this filter is capable of selecting optical waves at =1560 nm, the transmission efficiency of the filter is 100%. In designing and studying the optical properties of the filter, we used plane wave expansion and finite difference time domain methods. After designing the filter, we studied the impact of different parameters on the filtering behavior of the structure. The total footprint of the filter is less than 100 100 m2. Simplicity of design and ultra-compact dimensions are the most significant characteristics of our filter. Manuscript profile
      • Open Access Article

        8 - A New Robust Control Design Based on Feedback Compensator for Sssc
        علی عجمی احد چهاندیده شندی
        In this paper, the modified linearized Phillips-Heffron model is utilized to theoretically analyze asingle-machine infinite-bus (SMIB) installed with SSSC. Then, the results of this analysis are used forassessing the potential of an SSSC supplementary controller to impr More
        In this paper, the modified linearized Phillips-Heffron model is utilized to theoretically analyze asingle-machine infinite-bus (SMIB) installed with SSSC. Then, the results of this analysis are used forassessing the potential of an SSSC supplementary controller to improve the dynamic stability of apower system. This is carried out by measuring the electromechanical controllability through singularvalue decomposition (SVD) analysis. This controller is tuned for simultaneously shifting theundamped electromechanical modes to a prespecifed area in the s-plane. The issue of designing arobustly SSSC- based controller is considered and formulated as an optimization problem accordingto the eigenvalue-based multi-objective function consisting of the damping ratio of the undampedelectromechanical modes and the damping factor. Next, considering its high capability to find themost optimistic results, the Gravitational Search Algorithm (GSA) is used to solve this optimizationproblem. Wide ranges of operating conditions are considered in design process of the proposeddamping controller in order to guarantee its robustness. The effectiveness of the proposed controlleris demonstrated through eigenvalue analysis, controllability measure, nonlinear time-domainsimulation and some performance indices studies. The results show that the tuned GSA based SSSCcontroller which is designed by using the proposed multi-objective function has an outstandingcapability in damping power system low frequency oscillations, also it significantly improves thepower systems dynamic stability. Manuscript profile