Abstract :
JECEI is devoted to the research in Electrical and Computer Engineering. The editors would like to welcome you to the Eighth issue (Vol. 4, No. 2), that contains ten papers focusing on research works in Clustering and classification of heart disease, Radial and Halbach array PMLSM, Persian CAPTCHA, Low power high reliability flip-flop, Geolocating radiation sources based on TDOA, Robust adaptive attitude stabilization of a fighter aircraft, Reliability analysis of IEC61850-based substation automation architecture, Impulsive noise cancellation from ECG signal, Optimal finite-time control of positive linear discrete-time systems, and LPV control for speed of PMSM.
The first article entitled “Diagnosis of Heart Disease Based on Meta Heuristic Algorithms and Clustering Methods,” by S. Roostaee and H. R. Ghaffary, deals with the method of feature selection with binary cuckoo optimization algorithm which is implemented to reduce property. The main purpose is feature reduction and providing a more precise diagnosis of the disease. The proposed method is evaluated using three measures, accuracy, sensitivity and specificity. Considering a data set of MLR database including information about 303 people with 14 features, the superiority of the proposed method is indicated in terms of performance, accuracy and run time.
The article “Comparison of Radial and Halbach Array PMLSM by Employing 2-D Electromagnetic Finite Element Analysis,” by H. Moradi Cheshmeh Beigi and A. Khanmohamadian, compares two PM mover with quasi-Halbach array and radial topologies for PMLSM application. A detailed analytical modeling based on Maxwell equations is presented for analysis and design of PMLSM with Halbach array. Moreover, 2-D nonlinear time-stepping transient FEM is employed to demonstrate the validity of the analysis and parametric search. Finally, a design optimization method is applied to PMLSM with Halbach array. The obtained results show the increase of thrust force and flux density distribution in the air gap.
In the third article, entitled “Introducing New Trends for Persian CAPTCHA,” by F. Yaghmaee and M. Kamyar, authors introduce three different types for Persian CAPTCHA in different domains. In the first type, based on the particular characteristics of Persian writing such as contiguous writing and image processing techniques, high strength CAPTCHA is provided. In the second type, the meaning of Persian words are used to creating CAPTCHA. Finally, in the third type, the combination of image processing techniques and the meaning of Persian words are used. Experimental results show that the proposed CAPTCHAs have high security against attacks while Persian people can easily recognize them.
The forth article “A New Low Power High Reliability Flip-Flop Robust Against Process Variations,” by S. Yousefian Langroudi and R. Niaraki Asli, proposes a new low power high reliability flip-flop (LP-HRFF) which operates over 1GHz clock frequency and is structured based on an appropriate combination of dual interlocked storage cell, level converting techniques and clock signal controlled gates. The extensive simulations exhibit LP-HRFF has 0% single event upset rate against single transient events occurred on inputs and internal nodes and show the improvement of power consumption up to 42.8% and power delay product up to 24.6% compared with its counterparts. Simulation results approve the robustness and efficacy of the proposed flip-flop against process variations.
In the fifth article, entitled “A New Method for Geolocating Radiation Sources Based on Evolutionary Computation of TDOA Equations,” by S. V. Shojaedini et al., a new method for geolocating signal emitters based on EC concept is proposed. In the proposed method, two well-known members of EC techniques including BA and GA, are utilized to estimate the positions of emitters by optimizing the hyperbola equations resulted from TDOA of their radiated signals. The obtained simulation results are compared with ML estimator. The results show better performance of the EC family compared to ML in such way that they estimate the position of emitters even up to 33% and 30% more accurate than ML in the presence of 5% and 10% noise, respectively. Furthermore, it is shown that the accuracy of BA is about 3% to 12% better than GA.
The Sixth article, “Robust Adaptive Attitude Stabilization of a Fighter Aircraft in the Presence of Input Constraints,” by M. Bahmani and T. Binazadeh, in order to design a robust autopilot in the presence of the actuator saturation, proposes the new robust controller, namely AISM-CNF, as a combination of CNF and AISM controllers. The CNF part of controller is used for stabilization of the nominal system and also improvement of the transient performance by considering the actuator saturation. The AISM part guarantees robustness against the model uncertainties and/or external disturbances. Herein, the upper bound of the uncertain terms is estimated and therefore there is no need to the prior knowledge of the upper bound of the model uncertainties. Simulation results show the performance of the proposed AISM-CNF controller.
In the Seventh article entitled “Comparative Reliability Analysis of Substation Automation Architecture Based on IEC 61850 Standard,” by A. Mokari-Bolhasan and N. Taghizadegan-Kalantari, the reliability of IEC61850-based substation automation system comparatively considering venderʹs different intelligent electrical devices is evaluated. The technique is based on fault tree analysis approach and the tie sets methodology is used to evaluate quantitatively. The proposed method is implemented on Mianeh Aydoghmush substation automation system in 5 different scenarios. Producers’ intelligent electrical devices, in 3 different ranges of MTBF, are tested in various scenarios and reliability of system are evaluated quantitatively. The proposed method provides rate of change of system MTTF index.
Eighth paper “Adaptive-Filtering-Based Algorithm for Impulsive Noise Cancellation from ECG Signal,” by A. Khalili et al., deals with modeling real-life muscle noise with ?-stable probability distribution and adaptive filtering noise cancellation assessment with MCC as adaptive technique. Based on test on some data of MIT-BIH arrhythmia and EMBC databases, an improved SNR in any ECG signal corrupted by impulsive noise is achieved. The worst achieved improvement based on setting the best parameter values using trial and error for both filter and utilized algorithm is 9.5 dB with correlation coefficient value of 0.93. The SNR improvement on the whole utilized database records is 11.03 dB on average.
In the next article entitled “Optimal Finite-time Control of Positive Linear Discrete-time Systems,” by G. R. Rezaei et al., an optimal controller is designed such that in addition to minimizing the cost function, the positivity property of the optimal state trajectory of the closed-loop system is also guaranteed. Furthermore, state variables of the closed-loop system converge to the origin in finite steps. The LQR+ problem for the linear discrete time systems is stated. Once, the cost function with finite-time horizon is considered and another time the cost function with infinite-time horizon is assumed. In this regard, two theorems are given and proved which consider the problem of building positive and optimize linear time-varying discrete time systems. Finally, computer simulations are given to illustrate effective performance of the designed controller and also verify the theoretical results.
Finally, the tenth research work entitled “LPV Control for speed of permanent magnet synchronous motor (PMSM) with PWM Inverter,” by M. R. Alizadeh Pahlavani and H. Damroodi, deals with the modeling, analysis, design and simulation of a robust control method for a PMSM supplied with a PWM inverter based on a LPV H_? standard controller. Under the influence of uncertainties and external disturbances, by a variation of ±150% of motor parameters from the nominal values, the robust performance control problem is formulated as a LPV H_? standard scheme and it is solved by a suboptimal LMI iterative H_? strategy. Moreover, a simulation study is carried out to illustrate the effectiveness of the proposed method.
The editors of JECEI wish to take this opportunity to thank the scientists and reviewers around the world who have contributed their time and expertise in the preparation of the Eighth issue of the journal.
