فهرست مطالب

  • Volume:14 Issue: 2, 2020
  • تاریخ انتشار: 1399/04/25
  • تعداد عناوین: 14
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  • AliRahnamaei*, Azadeh KianiSarkaleh Pages 1-9

    In this article, the design procedure of a low latency Booth multiplier has been proposed. With the help of a novel 4-2 compressor, a high-performance16×16bitBoothmultiplier has been implemented,which depicts high operating frequency. To achieve this, the proposed 4-2 compressor has been utilized successively in the Partial Product Reduction Tree (PPRT) of the multiplier and by means of radix-4 Booth scheme,the multiplierhas been designed.The Partial Product (PP) generation circuitry is also based on the other work published by the authors which enables the designed structureto workat the frequency of 350MHz. The main advantage of the designed compressor is the elimination of the middle stage inverters between cascaded blocks of PPRT which considerably enhances the speed of whole system. Simulation results for TSMC 0.18μm CMOS technology and 1.8V power supply have been demonstrated to confirm thecorrect operationof proposed4-2 compressor.According to the results, the achieveddelay ofthe critical pathfor hard testand high capacitive load,equal to100fF,is936pswhileapower consumption of 255.15μWhas been achieved at the operating frequency of 100MHZ.

    Keywords: BoothMultiplier, Modified Booth Encoding Scheme, 4-2 Compressor, Radix-4, Low Latency
  • MohammadAskari Khanabadi*, Imaneh Dehghani, Shahrokh Shojaeian Pages 11-16

    Due to the high amounts of sugarcane residue or bagasse which was produced by sugarcane plants in Iran, this study was aimed to optimize power generation from bagasse biomass in sugarcane plants using Particle Swarm Optimization (PSO) algorithm by data obtained from several case studies which had been simulatedwith SQP (Sequential quadratic programming) algorithm. In these studies, bagasse containing 50% moisture content (MC) alone or with fossil fuels, as well asbagasse with a moisture content of 40% and 30% with fossil fuels wereused. Optimization values showed that 20% decrease in bagasse’s MC caused 55.6% increase in power generation efficiency, 36.3% reduction in gas emissions as well as 100% bagasse saving. PSO showed similar results to SQP and it seems that it is a proper algorithm than SQP. Therefore, if the bagasse is more dried by solar energy to lower MC, the greater efficiency of power generation is obtained.

    Keywords: Bagasse, Power Generation, PSO Algorithm, Optimization
  • HosseinLotfi*, AmirSafaei Nikooei, AliAsghar Shojaei, Reza Ghazi, Mohammad Bagher Naghibi Sistani Pages 17-23

    Penetration of distributed generation resources including wind power and solar photovoltaicunits in distribution system has been increased, and it is important to examine their impact on the distribution systems’ operationin term of reliability. In this paper, the multi-objective dynamicfeeder reconfiguration is introduced as an efficient approach for providing an energy management schedule in the distribution gridconsidering energy lossandenergy not supplied as the objective functions in the presence of renewable energy sourcesandcapacitor units.In addition, the effect of uncertaintyrelated to power demand is considered in the evaluations. Tothis end, anenhancedparticle swarm optimization algorithm is provided in this paper,the proposed approach is applied to the 33-node testing system.

    Keywords: Dynamic Distribution Feeder Reconfiguration (DDFR), Distributed Generators (DGs), Enhanced Particle Swarm Optimization Algorithm (EPSO), Multi-ObjectiveOptimization
  • Saviz Ebrahimi, FarbodSetoudeh*, Mohammad Bagher Tavakoli Pages 25-34

    Thispaper presents a modified model to calculate the fractal dimension of digital images. Theestimation of fractal dimensions is crucial to fractal analysis and is popularly carried out through methods based on box counting. The problem with these approaches is that, most of them do not remove the potential effects of noise on fractal dimensions properly. Accordingly, this study examines the effects of three different type of noises on fractal dimensions using different images taken from Background image database. The examination shows thatthe fractal dimensions change significantly, after noise adding,so we put forward a noise-robust and efficient fractal dimension calculation methodwhichis a combination of two methods,the gray-level co-matrix algorithm and improved box counting method. Theresults of experiments on the Background image dataset confirm the robustness and efficiency of the proposed method.

    Keywords: Box-CountingAlgorithm, Fractal Dimension, Gray-Level Co-Matrix, Image, Noise
  • Seyed Hamid Tabatabaei, Amir Hossein Zaeri*, Mohammad Vahedi Pages 35-42

    We proposea newimpedance control algorithmfordelayed linear bilateral teleoperation systems. In thepresented control strategy, with regard to a preferredimpedance model for the master and slave robots, aspecialdynamic featureat the human and the masterrobotalong withthe slaverobotand environment interface isproposed. In addition, external forces signalsincluding operator and remote environmental forcesare used in the controllerto attain desired impedance model.A force estimationschemeispresentedto removemeasurement of external forces. Then, thedesiredimpedance model is locatedintoanappropriatesliding-mode control schemeto compensatetheparametersuncertainties emerged by external force estimation errors. Then, the absolute stability criterionis usedto investigatethe stability of theclosed-loopteleoperationsystemalong withtransparency. Consequently, the control strategyis implemented on 1-DOF robotic systemas the master and slave robots. Simulation results verifythe effectivenessof the presentedimpedance controller by usingestimated external forces.

    Keywords: Teleoperation, Impedance ControlScheme, Time Delay, Force Estimation, Absolute Stability
  • Hamid Ghadiri* Pages 43-49

    Nowadays, power systems should be operated in the highest level of utilization and near their stability limits because of economic reasons. So stability assessment of the power system to determine the stability limits has been always considered. In SCADA/EMS systems a constant value called security margin and steady-state stability limit are used to determine transient stability limit instead of time-domain simulation. The security margin that is almost constant for power systems is determined experimentally. In this article this constant is computed using a probabilistic neural network and this method is implemented on IEEE 39 bus. As a result,the performance of this neural network is suitable for this application.

    Keywords: Power System Stability, Transient Stability Limit, Steady-State Stability Limit, Security Margin
  • ShabnamNasr Esfahani, Majid Delshad*, Mohammad Bagher Tavakoli Pages 51-59

    n this paper, a novellossless snubberis introduced that provides ZVS conditions forbothOn and Off instant of converter switches. On one hand, the energy of the snubberis optimally transmitted to the output so that no significant losses are imposed on the converter. Since the converter diodes are switched off as ZCS, the reverse recovery problem is reduced. Inthis paper, the proposed snubbercircuit is applied to a conventional boost converter and an 80W sample is constructed in the laboratory to prove the performance andtheoreticalanalysis. Furthermore, in order to confirm the effectiveness of the proposed snubberon the reduction of Electromagnetic Interference (EMI), the EMI value of the boost converter with the proposed snubberhas been compared with the conventional boost converter, which shows a decrease of 10dBμV.

    Keywords: LosslessPassive Snapper, Zero Current SwitchingCondition(ZCS), Zero Voltage SwitchingCondition(ZVS), Electromagnetic Interference (EMI)
  • Shahrokh Hatefi *, Khaled Abou-El-Hossein Pages 61-70

    Ultra-High precision Single-Point Diamond Turning (SPDT) is a widely used machining technology for generationcomponents withoptical grade surfaces. SPDT has been widely used in different industry sectors including aerospace, biomedical, military, defense, electronics, and entertainment. By using SPDT,manufacturing of optical surfaces with roughness down to one nanometer, evenless than one nanometer, is possible. Recently, the application of non-conventional SPDT techniquesduring SPDTfor improving the outcome of the process has been emerging. Non-conventional machining techniques have been developed and used during SPDT for assisting the process from different capacities. It hasbeenrevealed that by using a sole or a combination of non-conventional techniques during SPDT,superior results in terms of optical surface roughness and surface profile accuracy could be obtained. However, non-conventional SPDT technologies are novel solutions and more research need to be undertaken in terms of optimizingthese processes and improving their performance. In this study, a novel high-precision hybrid controller is designed and developed for using in non-conventional SPDT processes. The proposed hybrid controlled has the capability of automatically and precisely control different non-conventional machining techniques during the diamond turning process.This controller could be used in a hybrid SPDT platform for controlling implemented machining techniques and synchronizing them. In addition, this hybrid controller could connect to on-machine metrology devices for in-process data acquisition, analyzing process parameters, and determining machining conditions. Thus, in-process tuning of the working parameters is possible. Results of simulations and experimental study have shown the functionalityof the developed controller with sufficient precision to be used in such ultra-precision non-conventional SPDT processes.

    Keywords: Ultra-Precision Machining, Hybrid Machining, Non-Conventional Machining, Single-Point Diamond Turning, Control System, Hybrid Controller
  • Mohammadreza Asgarirad*, Mansour Nejati Jahromi Pages 71-80

    Hundreds of millions of homes worldwide already Have Fiber to The Home (FTTH)broadband connections since this technology holds many advantages over current technologies. The need for higher bandwidth by customers persiststhe network providers to upgrade their networks.TheFTTH is the use of fiber optic cords to deliver communications signals from an operator’s central network to individual houses, buildings,residences,andchanging old copper infrastructuresin order toprovide higher bandwidth to customers.Recently NG-PON capabilitieshas opened new approach in optical fiber networks creation,operators are trying to use a single infrastructure in access layer for fixed and mobile(4G/5G)services.However, the FTTH implementation is challenging for network operators in consideration of a large amount of investment,including Capital Expenditure (CAPEX) and Operational Expenditure (OPEX). The review and classification of the most relevant approachesaboutcost reduction of FTTH implementation is done in this paperbased on a novel taxonomy.

    Keywords: Fiber to the Home (FTTH), Cost Estimation, Capital Expenditures (CAPEX), Operating Expenditures (OPEX)
  • Naveen Kumar*, Jyoti Ohri Pages 81-92

    Recently,robotic manipulatorsare the key industry requirement. These have find the importance to enhance the productivity as well as accuracy. Furthermore, industries are also moving towards the use of Flexible Link Manipulator (FLM) owing to their unique characteristics i.e. light weight, high speed operations, and the larger workspace. The FLM system has flexibility of link that causes vibrations and oscillations which affect adversary to the performance of robotic arm. The performance of FLM system is measured w.r.t. minimum error and oscillations in trajectory tracking. In this research paper, an attempt has been made to overcome the complications of FLM system. A full state feedback Linear Quadratic Regulator (LQR), is designed for FLM. It is observed that the designed controller can enhancethe accuracy of the robotic arm,while reducingoscillations and vibrations. In addition, to enhance the performance of controller and to reduce the hassle in terms ofselecting the parameter of Q matrix in LQR, modified particle swarm optimization (m-PSO) is used. The effectiveness of designed controller is simulated in MATLAB. Further, the validation of designed controller is tested on hardware FLM device. The resultsobtainedfromthesimulation and hardware are compared.

    Keywords: PSO, FLM, LQR, Vibration, Tracking Error
  • Sundaram Bharatbhai Pandya*, Hitesh R. Jariwala Pages 93-110

    The recent state of electrical system comprises the conventional generating units along with the sources of renewable energy. The suggested article recommends a method for the solution of single and multi-objective optimal power flow, incorporating wind energy with traditional coal-based generating stations. In this article, the two thermal power plants are replaced with the wind power plants. The techno-economic analysis are done with this state of electrical system. In proposed work, Weibull probability distribution functions is used for calculating wind power output. A non-dominated sorting based multi-objective moth flame optimization technique is used for the optimization issue. The fuzzy decision-making approach is applied for extracting the best compromise solution. The results are authenticated though modified IEEE-30 bus test system, which is combined with wind and thermal generating plants.

    Keywords: Wind Units, Metaheuristics, Stochastic, Probability Density Function
  • Hooman Khamooshpoor, Mehdi Baharizadeh*, Mohammad Hossein Ershadi Pages 111-115

    DC microgrids have gained extensive attention in the recent years.In the islanded mode of operationpower sharing between sources is required. The power sharing usually is provided by employing P-V droop characteristicswhile the voltage local property results in power sharing error. In this paper two decentralized approaches for resolving power sharing error are studied and compared. Inthefirst approach, sources employ proper virtual resistance. In second approach, droop characteristics are realized in the Point of Common Coupling (PCC). It isshown that by using second approach,the voltage drop is reduced and equally the voltage quality is improved. It isdiscussed that the reason is bypassing the voltage drop associated with the sources output resistancein the second approach.Time domain simulations of a test DC microgrid are provided to verify the results.

    Keywords: DC Microgrids, Distributed Energy Resources, Droop Characteristics, Power Sharing
  • oktam Jafarpour, Farouk Smith* Pages 117-125

    One of the main focus areasin human body reconstruction is the regeneration of bone tissue in different body zones by using variousreconstruction applications. In the last two decades, different efforts have been undertaken for developing new bone reconstruction methods,andsupportingtechniques for stimulating bone healing mechanisms. It has been shown that during different Bone Reconstruction Applications(BRA), the presence of laser light could enhance the bone regeneration and healing mechanisms, while shortening the treatment time and improving the quality of newly formedbone tissue. The application of Low-Level Laser Therapy(LLLT)has recently been used for newbone reconstruction applicationsin different body parts,including the tibia, fibula, femur, humerus, radius, and mandible. It wasshown that by applying a low-power laser light during the bone healing procedure in different treatments, an improved quality of regenerated bone tissuewas evident,while accelerating bone healing mechanisms. However, only a few studies have been performedwith regard to the development of specific LLLT devices for such advanced bone reconstruction procedures. More research needs to be done towards developing anideal LLLT device to be used in different bone reconstruction techniques. The purpose of this research is to design a novel multi-wavelength LLLT device with controllablelaserlight intensity. In addition, by using such a mechanism,generating the laser light in single-and multi-wavelengthsin predetermined working sequences is possible. The design specifications and simulation results have shown that the proposed systemis functional while meeting all required specifications in terms of generating a single-or multi-wavelength laser light,with controllable power intensity. Therefore, in future developments, the proposed system could be used during BRAfor assisting the treatment.

    Keywords: Low-Level Laser Therapy, Bone Reconstruction, Light therapy, Laser-Assisted Treatment
  • Mina Yazdanbakhsh, Reihaneh Khorsand Motlagh Isfahani*, Mohammadreza Ramezanpour Pages 127-141

    Cloud computing is introduced as a high-performance computing environment that manages a variety ofvirtualized resources. One of the major aspects of cloud computing is its dynamic scheduling of great number of task requests that are submitted by users. Cloud data centers in addition to implementing these tasks, should meet the conflicting multiple requirements of different users. Minimizing makespan and deadline violation on a great number of tasks aredifficult while costs are reduced. Therefore, in this paper, a multi-objective strategy for dynamic task scheduling through elastic cloud resources (MODE) is proposed, where an algorithm is proposed to construct individual non-dominated sets of new received tasks. These non-dominated sets are sorted in different levels through a new crowding distance ofthe individuals. In addition, an elastic resource provisioning based on the maximum available VMs’ load is proposed to provide resources in a dynamic manner. The total cost, makespan,and the deadline violations are reduced by 85.84%, 58.03%, and47.77%,respectively, andthe utilization of virtual machinesis increasedup to 53.2% through this strategy when compared toits counterparts.

    Keywords: Cloud Computing, Dynamic Task Scheduling, Multi-Objective Scheduling, Elasticity, Quality of Service