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  1 - A Review of Sensorless Control Methods for Induction Motor Drives
  Abdolreza Sadighmanesh Mohammad Rahimzadeh
  Induction motors have become popular in the home appliance and industry due to their ‎advantages over other motors . ‎ These motors require drives for control . ‎ The use of sensorless ‎drive for induction motors is expanding due to its advantages. The a More

  Induction motors have become popular in the home appliance and industry due to their ‎advantages over other motors . ‎ These motors require drives for control . ‎ The use of sensorless ‎drive for induction motors is expanding due to its advantages. The advantages of sensorless ‎motor drives include increased reliability, reduced hardware complexity, lower cost ,better ‎noise immunity, and less maintenance requirements. With the advancement of industry and the ‎development of modern industry, more efficient and advanced methods are required for ‎sensorless control of induction motors. In this paper, sensorless control methods for induction ‎motors are introduced and their operation and performance in different modes are investigated. ‎The advantages and superiority of each method over other methods are examined and the ‎simulation forms of the new model reference adaptive system (MRAS)‎ and Classical rotor flux ‎MRAS speed observer methods are given and these two methods are compared with other ‎methods.‎ Manuscript profile
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  2 - Modelling of relation between large earthquakes and ionosphere electron density using GPS data
  Tohid malekzadeh Dilmaghani
  The ionosphere is a part of the earth's atmosphere, laying at the heights between 50 km and 2000 km above the earth's surface, and consisting of several layers identified by differences in the level of ionization. In the customary two dimensional modeling techniques, io More

  The ionosphere is a part of the earth's atmosphere, laying at the heights between 50 km and 2000 km above the earth's surface, and consisting of several layers identified by differences in the level of ionization. In the customary two dimensional modeling techniques, ionosphere is approximated by a thin spherical shell of free electrons, located; 250 to 450 Km from the surface of the earth. The existing two dimensional methods of modeling the electron density can be classified to non-grid based and grid based techniques. The former modeling techniques are based on the least squares estimation of a functional model for certain types of observables derived from the GPS carrier phase and code measurements. The network consists of two parts: a) base network that covers the entire country of Iran, consisting of 41 GPS stations and b) three local networks in the most populated and active zones. The local networks are established in Tehran, Azerbaijan, and Khorasan with critical tectonic activities. GPS measurements of 12 successive days in August 2012 (DOY#219, 220, 221, 222, 223, 224, 225, 226, 227, 228, 229 and 230) have been used for modeling and processing. VTEC values at a temporal resolution of 15 min were derived from the dual frequency GPS receivers. According to results, it can be easily deduced that there are temporal variations in the electron content of the ionosphere. The characteristics which are the constituents of the ionosphere morphology are also reported elsewhere and confirmed by the analysis of the direct measurement techniques. The diurnal pattern of TEC exhibited a steady decrease from DOY#220. This decline has occurred at all hours. Also using these results can be clearly seen that the maximum value of TEC observed in daytime (8 UT), while the lowest occurred at nighttime (4 UT). Manuscript profile
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  3 - An overview of mainframe operating systems and their applications in blockchain e-commerce
  mosa hajipoor
  AbstractIn spite of the fact that E-commerce networks are new to networks, it very well may be contended that there are valid justifications for them to grow. The financial business knows about the force and ability of online media and empowers banks to arrive at more c More

  AbstractIn spite of the fact that E-commerce networks are new to networks, it very well may be contended that there are valid justifications for them to grow. The financial business knows about the force and ability of online media and empowers banks to arrive at more clients through conventional channels, yet as of now, web-based media banking is restricted to item showcasing, client commitment and backing up. As channels and administration conveyance components create in banks, bank supervisors absolutely reserve an option to be worried about observing the exchanges of such organizations and to turn into their fundamental concern. Manuscript profile
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  4 - Friction System Simulation on Electro-Mechanic Systems
  Mohammad Esmaeil akbari Sajjad Atazadeh alireza mangouri sahand akbari
  In the present study identified friction using a single test were examined. Identify friction Using GMS, which includes four diagrams are friction regime and the stimulation signal has an important role to identify the individual tests. The simulation results showed tha More

  In the present study identified friction using a single test were examined. Identify friction Using GMS, which includes four diagrams are friction regime and the stimulation signal has an important role to identify the individual tests. The simulation results showed that electromechanical systems using MATLAB software can be used to reduce friction and damage caused by the friction is somewhat less. Manuscript profile
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  5 - Power system stability control and voltage stabilization for a wind farm based on adaptive dynamic programming
  ali khodadadi Mohammad Esmaeil akbari Hosein Nasir Aghdam
  In this research, control system based on adaptive dynamic programming (GrHDP), presented for Wind farm Double-Fed Induction Generator (DFIG) in order to improve transient stability system under error conditions. Suggersted controller, implemented according to the inter More

  In this research, control system based on adaptive dynamic programming (GrHDP), presented for Wind farm Double-Fed Induction Generator (DFIG) in order to improve transient stability system under error conditions. Suggersted controller, implemented according to the interaction between the controller and plant as a based- adaptive dynamic programming (ADP) and based on pproximation of optimal control mode. The programming and simulation provided in MATLAB soft ware and the effectiveness of the proposed approach corroborated via two cases: The first case investigates a revised four-machine two-area system with high wind penetration and a static synchronous compensator. The second case is a practical size power system with wind farm based on actual data. In addition, detailed simulation analysis and comparative studies with traditional ADP approaches presented to demonstrate the superior performance of our method. Manuscript profile
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  6 - The effect of inner ring radius on frequency and insertion loss of optical filters with ring resonator structure
  yagoob hasanzade Abdollah Alizadeh
  In this paper an optical filter having ring resonator structure with micro rings inside it, has been investigated. By variation the radius of main and inner rings, the variation of central frequency and insertion loss of filter in communication spectrum (1.5 µm to More

  In this paper an optical filter having ring resonator structure with micro rings inside it, has been investigated. By variation the radius of main and inner rings, the variation of central frequency and insertion loss of filter in communication spectrum (1.5 µm to 1.6 µm) have been studied. By increasing the radius of main ring, the central frequency of filter move toward the lower frequencies, then central frequency of filter can be adjusted by the radius of main ring. Radius variation of main ring has not considerable effect in filter loss. Also, variation of inner ring’s radius, affects the filter insertion loss, and have a little displacement on the central frequency of filter. The maintained filter will have the minimum loss, when the inner rings radius have been selected equally 0.2 micrometer. By proper selection of radius sizes one can tune the filter precisely for desired resonance frequency and loss. Manuscript profile