Showing papers in "Bulletin of Electrical Engineering and Informatics in 2015"
TL;DR: In this article, the authors introduce an approach to identify this type of journals that will be applicable by researchers in various academic disciplines, which will be used to enhance the academic standards of Universities, especially those that are indexed in websites such as Thomson Reuters.
Abstract: By developing research and academic centers, the number of performed research articles has also increased. On the other hand, publishing the results of these articles in scientific journals shall also grow. In the meantime, researchers are trying to publish the findings of their research in journals which have been approved by one or more international indices so that such findings can be seen. In order to enhance the academic standards of Universities, proper journal choice will be of interest to researchers, especially those that are indexed in websites such as Thomson Reuters. However, certain forgery frauds researchers by launching fake Web sites that have been named by academic journal titles. In this paper, we introduce an approach to identify this type of journals that will be applicable by researchers in various academic disciplines.
38 citations
TL;DR: In this article, different methods of MPPT and their advantages are investigated and the first step toward selecting a useful method is recognizing algorithms, methodology, and advantages of each method, and then, the nonlinear behavior of photovoltaic cells is demonstrated.
Abstract: One of the most important issues associated with photovoltaic systems is receiving maximum power and tracking maximum power point. Hence, researchers have proposed numerous methods in recent years. The first step toward selecting a useful method is recognizing algorithms, methodology and advantages of each method. In this study MPPT methods are deeply investigated. For this purpose, first off, equations governing photovoltaic systems are explicated. Then, nonlinear behavior of photovoltaic cells is demonstrated by simulation. Finally, different methods of MPPT and their advantages are mentioned.
13 citations
TL;DR: In this paper several new techniques are used to reduce the switches and DC sources, which overcome the disadvantages of cascaded multilevel inverter.
Abstract: Harmonics and increasing number of switches and DC sources for increasing level is the major issue in the cascaded multilevel inverter for the application of medium and high voltage power system applications. In this paper several new techniques are used to reduce the switches and DC sources, which overcome the disadvantages of cascaded multilevel inverter. The THD values for various levels (seven & nine) are compared with and without PWM technique.
12 citations
TL;DR: In this paper, a comparison of the intelligent and advanced speed control methods based on PWM technique and PI controller to achieve maximum torque and efficiency is presented for induction motor without any controller and with PI controller on full load condition.
Abstract: The induction motor is without doubt the most used electrical motor because of its unique characteristics. Most of its applications need fast and intelligent speed control system. This paper presents comparison of the intelligent and advanced speed control methods based on PWM technique and PI controller to achieve maximum torque and efficiency. Simulation is carried out in MATLAB environment and results are investigated for speed control of induction motor without any controller and with PI controller on full load condition.
12 citations
TL;DR: A fuzzy logic speed controller for DC motor is designed and it’s parameter calculated by Particle Sward Optimization (PSO), then for having better performance, the controller optimized with PSO.
Abstract: The Direct current motors are in different types and there are several methods for controlling of their speed. In this paper two ways for speed controlling suggested. First a fuzzy logic speed controller for DC motor is designed and it’s parameter calculated by Particle Sward Optimization (PSO). The speed controller designed according to fuzzy rules, then for having better performance, the controller optimized with PSO. Secondly a PID controller that it’s parameter find by PSO, is used for speed controlling of a DC motor. At the end the performance of fuzzy logic controller compared with PID controller. The results show that fuzzy-PSO controller has better performance.
11 citations
TL;DR: It was concluded that the temperature effect than radiation effect on photovoltaic system designing is overlooked, which means a low-effect power changes per temperature changes against radiation.
Abstract: One of the best ways to identify and design a system is simulating and to achieve this goal, we use simulation software such as MATLAB Simulink. In this study, the relations ruling photovoltaic is described. Then, on the relations basis, a photovoltaic system is simulated in MATLAB software. After photovoltaic system simulation, regardless the specific geographic area, radiation and temperature effect on photovoltaic system is generally simulated. Finally, with regard to radiation and temperature values effect on, it was concluded that we overlook the temperature effect than radiation effect on photovoltaic system designing. It certainly does not mean overlooking the temperature effect. It means a low-effect power changes per temperature changes against radiation.
10 citations
TL;DR: In this paper, a high efficiency RF power amplifier was proposed to cope with the problem of battery lifetime limitations in portable RFID code reader. But the performance of the proposed power amplifier at frequency of 2.4GHz was evaluated using 0.18 μm RFCMOS.
Abstract: Power amplifiers (PAs) are usually the largest consumer of power in the transmitter . Therefore , designing a high efficiency RF power amplifier might be the best solution to cope with the problem of battery lifetime limitations in portable RFID code reader . I n this paper, the designed circuit in Agilent ADS software is implemented using 0.18 μm RFCMOS technology at 3.3 v supply voltage . The measured results indicate that power added efficiency,out put power and power gain of the proposed class AB power amplifier at frequency of 2.4GHz are 35% , 30 dBm and 28dBm.
8 citations
TL;DR: The cloud-based LBS system proposed in this paper is able to achieve privacy protection from the confidentiality of outsourced data and integrity of service results, and can be used as a reference while developing LBS systems under mobile cloud computing environment.
Abstract: Location-based services can provide personalized services based on location information of moving objects and have already been widely used in public safety services, transportation, entertainment and many other areas. With the rapid development of mobile communication technology and popularization of intelligent terminals, there will be great commercial prospects to provide location-based services under mobile cloud computing environment. However, the high adhesion degree of mobile terminals to users not only brings facility but also results in the risk of privacy leak. The paper introduced the necessities and advantages to provide location-based services under mobile cloud computing environment, stressed the importance to protect location privacy in LBS services, pointed out new security risks brought by mobile cloud computing, and proposed a new framework and implementation method of LBS service. The cloud-based LBS system proposed in this paper is able to achieve privacy protection from the confidentiality of outsourced data and integrity of service results, and can be used as a reference while developing LBS system under mobile cloud computing environment.
7 citations
TL;DR: In this paper, a bidirectional DC-DC converter with high voltage conversion ratio was proposed, which uses the three windings coupled-inductive inductor to achieve high step-down voltage gain.
Abstract: A novel bidirectional DC-DC converter with high conversion ratio is proposed in this paper. The proposed converter uses the three windings coupled-inductor to achieved high voltage conversion ratio. The primary side consist of a winding and secondary side consist of two windings, which these two windings are series to achieved high voltage gain.In the boost mode, a capacitor is parallel charged and series discharged by the coupled inductor. Thus, high step-up voltage gain can be achieved with an appropriate duty ratio. In the buck mode, a capacitor is series charged and parallel discharged by the coupled inductor. The bidirectional converter can have high step-down voltage gain.The stress voltage of main switches can be reduced, and efficiency can be improved. The operating principle and the steady-state analyses of the voltage gain are discussed. Finally, in 24V for low voltage, and 400V for high voltage, and 200W for output power, this converter is simulated in MATLAB.
7 citations
TL;DR: In this article, a steel tube of 50 cm long having outside diameter of 60 mm and inside diameter of 30 mm with constant outside surface temperature of 1000, 1200 and 1400 K o is numerically analyzed.
Abstract: Turbulent forced convection of coolant air flow (10 m/s velocity) in a steel tube of 50 cm long having outside diameter of 60 mm and inside diameter of 30 mm with constant outside surface temperature of 1000, 1200 and 1400 K o is numerically analyzed. The renormalization group k-e model is used to simulate turbulence in ANSYS - FLUENT 14.5. An opened ring of rectangular cross section (5x7 mm) is fitted in the tube and separated by 8cm pitch. Results of temperature and velocity distribution along the tube center line for the case of tube with internal ribs were compared with that of plain tube , these results show that the use of internal ribs enhance the heat transfer rate and found to possess the highest performance factors for turbulent flow.
7 citations
TL;DR: In this paper, the operation of the boost dc-dc converter with high voltage gain is analyzed and the critical inductance between CCM and DCM in addition to CISM and IISM is calculated.
Abstract: In the high voltage dc-dc boost converters, the energy transmission modes are divided into continuous conduction mode (CCM) and discontinuous conduction mode (DCM). In addition, these modes are also divided into two different modes: complete inductor supply mode (CISM) and incomplete inductor supply mode (IISM). In this paper, the operation of the boost dc-dc converter with high voltage gain is analyzed. Firstly, the energy transmission process between CCM and DCM is analyzed. Then, this process is investigated between IISM and CISM. Moreover, the critical inductance between CCM and DCM in addition to CISM and IISM is calculated. Finally, in order to verify the presented theoretical issues, the simulation results in EMTDC/PSCAD software program are used.
TL;DR: In this paper, a meta heuristic Harmony Search Algorithm (HSA) is used to simultaneously reconfigure and identify the optimal locations for installation of DG units in a distribution network.
Abstract: Due to dynamic nature of loads, total system load is more than its generation capacity that makes relieving of load on the feeders not possible and hence voltage profile of the system will not be improved to the required level. In order to meet required level of load demand, Reconfiguration & DG units are integrated in distribution network to improve voltage profile, to provide reliable and uninterrupted power supply and also to achieve economic benefits such as minimum power loss, energy efficiency and load leveling. This work proposes minimization of real power losses and improvement of voltage profile using network reconfiguration in the presence of distributed generation. Generally distributed generations (DG) are preferred with objective of minimizing real power loss and improving voltage profile in distribution system. In this work A meta heuristic Harmony Search Algorithm (HSA) is used to simultaneously reconfigure and identify the optimal locations for installation of DG units in a distribution network. Sensitivity analysis is used to identify optimal locations for installation of DG units. The proposed method has tested in MATLAB for 33-bus and 69- Bus radial distribution systems at three different load levels and the analysis is presented for loss minimization.
TL;DR: Experimental results have shown that the proposed fuzzy scheduler saves more energy and creates feasible schedules for real time tasks, and considers tasks priorities which cause higher system utilization and lower deadline miss time.
Abstract: Reducing energy consumption is a critical issue in the design of battery-powered real time systems to prolong battery life. With dynamic voltage scaling (DVS) processors, energy consumption can be reduced efficiently by making appropriate decisions on the processor speed/voltage during the scheduling of real time tasks. Scheduling decision is usually based on parameters which are assumed to be crisp. However, in many circumstances the values of these parameters are vague. The vagueness of parameters suggests that to develop a fuzzy logic approach to reduce energy consumption by determining the appropriate supply-voltage/speed of the processor provided that timing constraints are guaranteed. Intensive simulated experiments and qualitative comparisons with the most related literature have been conducted in the context of dependent real-time tasks. Experimental results have shown that the proposed fuzzy scheduler saves more energy and creates feasible schedules for real time tasks. It also considers tasks priorities which cause higher system utilization and lower deadline miss time.
TL;DR: Adaptive robust control approach is used that it can to compensate Uncertainty parameters of the system and present a smooth system with maximum energy production.
Abstract: In this work we want to propose a control strategy to maximize the wind energy captured in a variable speed wind turbines, for this goal the speed of turbine should keep in optimum speed when the wind speed is changing. Many control approach has been suggested that is base on approximate models that it causes unsuitable behavior of system because of Uncertainty parameters of the system. Hence at this work we use adaptive robust control approach that it can to compensate Uncertain of the parameters and present a smooth system with maximum energy production. Numerical simulations are given to illustrate the effectiveness and validity of the proposed approach.
TL;DR: In this article, interleaving and switched-capacitor techniques are used to introduce a high step-up DC-DC converter for renewable energy systems application, which delivers high voltage gain without utilizing transformer or excessive duty cycle and features ripple-free input current which results in lower conduction losses and decreased electromagnetic interference.
Abstract: In this paper interleaving and switched-capacitor techniques are used to introduce a high step-up DC-DC converter for renewable energy systems application. The proposed converter delivers high voltage gain without utilizing transformer or excessive duty cycle and features ripple-free input current which results in lower conduction losses and decreased electromagnetic interference (EMI). Lower output capacitance is another advantage of proposed converter, leading to smaller size and lower cost. Furthermore lower voltage stress on switches allows the utilization of switches with low resistance. Simulation results verify the performance of suggested converter.
TL;DR: In this paper, a power amplifier was designed by Class F type at 1800 MHz with 60% efficiency and output powers of 30 dBm, based on 0.18 μm TSMC RF CMOS technology and supply voltage of 3.3V on transistor level.
Abstract: Based on the portable systems application, it is necessary to design blocks with high efficiency to increase battery lifetime. Power amplifier is the highest power consumption block in transmitter. The proposed circuit was simulated using ADS Agilent based on 0.18 μm TSMC RF CMOS technology and supply voltage of 3.3V on transistor level. The proposed power amplifier was designed by Class F type at 1800 MHz with 60% efficiency and output powers of 30 dBm.
TL;DR: The purpose of this paper is to design a transformation process that can transfer the entire discrete logarithm and integer factorization based cryptosystems into the ID-based systems rather than re-invent a new system.
Abstract: Shamir proposed the concept of the ID-based Encryption (IBE) in [1]. Instead of generating and publishing a public key for each user, the ID-based scheme permits each user to choose his name or network address as his public key. This is advantageous to public-key cryptosystems because the public-key verification is so easy and direct. In such a way, a large public key file is not required. Since new cryptographic schemes always face security challenges and many integer factorization and discrete logarithm based cryptographic systems have been deployed, therefore, the purpose of this paper is to design a transformation process that can transfer the entire discrete logarithm and integer factorization based cryptosystems into the ID-based systems rather than re-invent a new system. We consider the security against a conspiracy of some entities in the proposed system and show the possibility of establishing a more secure system.
TL;DR: There are several approaches to speed estimation of an induction motor, which can be classified into two types, namely, estimation based on the machine model and estimation based based on magnetic saliency and air gap space harmonics.
Abstract: Speed Estimation without speed sensors is a complex phenomenon and is overly dependent on the machine parameters. It is all the more significant during low speed or near zero speed operation. There are several approaches to speed estimation of an induction motor. Eventually, they can be classified into two types, namely, estimation based on the machine model and estimation based on magnetic saliency and air gap space harmonics. This paper, through a brief literature survey, attempts to give an overview of the fundamentals and the current trends in various machine model based speed estimation techniques which have occupied and continue to occupy a great amount of research space.
TL;DR: In this article, artificial neural network (ANN) controllers have been designed to control the front end temperature and back end temperature of a 2x2 lime kiln process with two manipulated variables namely the fuel gas flowrate, and the percent opening of the induced draft damper.
Abstract: The lime kiln is a very complex multivariable process with severe non linearities, high degree of coupling and frequent disturbances. In this paper a 2x2 lime kiln process with two manipulated variables namely the fuel gas flowrate, and the percent opening of the induced draft damper and two controlled variables namely front end temperature and back end temperature has been considered. After its decoupling, artificial neural network (ANN) controllers have been designed to control the front end temperature. The performance of ANN controllers have been compared with that of conventional controllers.
TL;DR: A new method of signal flow graph technique and Mason’s gain formula are applied for extracting the model and transfer functions from control to output and from input to output of a buck-boost converter.
Abstract: In this paper, a new method of signal flow graph technique and Mason’s gain formula are applied for extracting the model and transfer functions from control to output and from input to output of a buck-boost converter. In order to investigate necessity of a controller for the converter with assumed parameters, the frequency and time domain analysis is done and the open loop system characteristics are verified. In addition, the needed closed loop controlled system specifications are determined. Moreover, designing a controller for the mentioned converter system based on the extracted model is discussed. For this purpose, a proportional-integral-derivative (PID) controller is designed and the hybrid of genetic algorithm (GA) and particle swarm optimization (PSO), called H-GA-PSO method is used for tuning of the PID controller. Finally, the simulation results are used to show the performance of the proposed modeling and regulation methods.
TL;DR: The newly developed beta cryptosystem is efficient with respect to encryption and decryption and the validity of this algorithm is proven by applying to message that are text and returning the original message in numerical examples.
Abstract: This paper, we introduce mainly the concept of beta cryptosystem, whose security is based on generalized discrete logarithm problem and integer factorization problem in the multiplicative group of finite fields. We show that the proposed public key cryptosystem based on generalized discrete logarithm problem and integer factorization problem, provides more security because of double computation comparing with the generalized discrete logarithm problem and integer factorization problem. Hence the adversary has to solve distinct discrete logarithm problems and integer factorization problem simultaneously in the multiplicative group of finite fields in order to recover a corresponding plaintext from the received cipertext. Therefore, this scheme is expected to gain a higher level of security. We next show that, the newly developed scheme is efficient with respect to encryption and decryption and the validity of this algorithm is proven by applying to message that are text and returning the original message in numerical examples.
TL;DR: In this paper, a novel space vector modulation (SVM) method for an indirect matrix converter (IMC) is used to reduce the common mode voltage (CMV) in the output.
Abstract: A novel space vector modulation (SVM) method for an indirect matrix converter (IMC) is used to reduce the common -mode voltage (CMV) in the output. The process of selecting required active vectors and to describe the switching sequence in the inverter stage of the IMC is explained in this paper. This novel SVM method used to decrease the peak -to-peak amplitude voltage of CMV without using any external hardware. The other advantage of this SVM method is to reduce the total harmonic distortion of line-to-line output voltage. This new modulation technique is easily implemented through simulation and its results are used to demonstrate the improved performance of the input/output waveforms.
TL;DR: This paper presented fuzzy MCDM approach based on risk and confidence analysis that it is believed is effective in tackling complex, ill-defined and human-oriented decision problems.
Abstract: The multicriteria decision problems involve uncertainty, it is important to incorporate different types of uncertainty in any proposed solution. In this paper, we presented fuzzy MCDM approach based on risk and confidence analysis that we believe is effective in tackling complex, ill-defined and human-oriented decision problems.
TL;DR: In this article, the authors discuss various methods for testing the performance of MEMS capacitive comb-finger accelerometers manufactured by Sandia National Laboratories and compare their performance with those of other accelerometers.
Abstract: This paper discusses various methods for testing the performance of MEMS capacitive comb-finger accelerometers manufactured by Sandia National Laboratories. The use of Capacitive MEMS devices requires complex circuits for measurement of capacitance and the Sandia MEMS accelerometer’s capacitance changes in a very small femto-farad (fF) range. The performance of accelerometer is tested using Analog Devices AD7747 sigma-delta capacitance to digital converter. The response of a MEMS capacitive accelerometer to various tests is useful for testing and characterization and investigate it’s suitability for various applications.
TL;DR: The security against a conspiracy of some entities in the proposed system is considered, the possibility of establishing a more secure system is shown, and hybrid mode problems factoring and discrete logarithm are considered.
Abstract: Shamir proposed the concept of the ID-based cryptosystem (IBC) in 1984. Instead of generating and publishing a public key for each user, the ID-based scheme permits each user to choose his name or network address as his public key. This is advantageous to public-key cryptosystems because the public-key verification is so easy and direct. In such a way, a large public key file is not required. Since new cryptographic schemes always face security challenges and many integer factorization problem and discrete logarithm based cryptographic systems have been deployed, therefore, the purpose of this paper is to design practical IBC using hybrid mode problems factoring and discrete logarithm. We consider the security against a conspiracy of some entities in the proposed system and show the possibility of establishing a more secure system.
TL;DR: In this article, a combination of NMCTF and Fuzzy Logic is proposed to control the position of the cart and to balance the pendulum in a linear servo system, which achieves high performance.
Abstract: Pendulum Balancing of Linear Servo System consists of a cart driven by a DC motor, via a rack and pinion mechanism to ensure consistent and continuous traction. The cart is also equipped with a rotary joint to which a free turning rod (or pendulum) can be attached. This concept paper proposed a combination of Nominal Characteristic Trajectory Following (NCTF) and Fuzzy Logic (FL) to control the position of the cart and to balance the pendulum. The proposed controllers are expected to have a simple design method and achieved high performances.
TL;DR: The finding results showed that the Wu–Palmer approach determine the similarity of senses as the most accurate, followed by the Lin, and Jiang–Conrath, and the combination of these measurements achieves higher accuracy in comparison with the individual result of each measure before.
Abstract: The methods and background introduced in this article concern on the interpretation of the Quranic text in English translation using word sense disambiguation. Three measures of semantic similarity measures: Wu-palmer, Lin and Jiang-Conrath, and their combination were used to identify words sense on the English Quranic text, in which comparison and detailed evaluation was carried out. The finding results showed that the Wu–Palmer approach determine the similarity of senses as the most accurate, followed by the Lin, and Jiang–Conrath. However, the combination of these measurements (novel method) achieves higher accuracy in comparison with the individual result of each measure before.
TL;DR: The effect of interruptible loads on the power system reliability is investigated and a multi machine power system is considered as cases study.
Abstract: In electric power systems, the generated power should be equal with the demand and power of network is mainly controlled through generation system. In such operation, the demand is satisfied through changing the generated power and afterward, the safe operation of power system is reached. But during recent years, a new concept has been developed in electric power systems namely demand side management (DSM). DSM is the modification of consumer demand for energy through various methods such as financial incentives and education. Usually, the goal of demand side management is to encourage the consumer to use less energy during peak hours, or to move the time of energy use to off-peak times such as nighttime and weekends. One of the important models of DSM is interruptible loads. Interruptible loads are the right for an electricity utility to interrupt supply to a customer, typically during a system emergency, to relieve short term network constraints up to a couple of hours. Interruptible loads can be deployed in one of two ways. The network operator gives notice of an interruptible load event to the customer, then relies on the customer to reduce their electricity usage; or unilaterally interrupts supply to the customer. In this paper, the effect of interruptible loads on the power system reliability is investigated. A multi machine power system is considered as cases study. Simulation results show the great effects of interruptible loads on the power system reliability.
TL;DR: In this article, a combined methodology of fuzzy analytic hierarchy process (FAHP) and data envelopment analysis (DEA) is proposed to apply it to multivariate analysis and integrated evaluation.
Abstract: In this paper, we propose a combined methodology of fuzzy analytic hierarchy process (FAHP) and data envelopment analysis (DEA) in order to apply it to multivariate analysis and integrated evaluation. With FAHP method, the relative importance levels of different available indicators are determined. And the DEA model is used to obtain the efficiency performances of the use case of network measurement. Finally network performance is evaluated by means of integrating available indicator weights with efficiency performances. It is quite important that the integrated methodology considers both personal preferences and objective relative efficiency for assessment simultaneously to avoid the bias of single methodology.
TL;DR: Wang et al. as discussed by the authors analyzed the major factors that affect the distribution of outlets and put forward a distribution model of outlets based on complex network, and analyzed the model to distribute and integrate its banking outlets.
Abstract: The distribution of real banking outlets is based on the establishment of branches according to administrative division, which is obviously not rational in distribution. Against this phenomenon, this paper first analyzes the major factors that affect the distribution of outlets. Then, based on complex network, it puts forward the distribution model of outlets. Finally, it analyzes the model. At the same time, the paper takes the banking outlets of China Construction Bank of Wuxi City, Jiangsu Province for example. It employs the model to distribute and integrate its banking outlets. As a result, the distribution after integrating is more rational than the previous distribution, which verifies the rationality of the model and the distribution method of banking outlets.