Self-repairing radix-2 signed-digit adder with multiple error detection, correction, and fault localization

Moradian, H.,Lee, J.A.,Hashmi, A. Pergamon Press 2016 Microelectronics and reliability Vol.63 No.-

<P>The advent of advanced microelectronic technologies and scale downing into nanometer dimensions has made current digital systems more susceptible to faults and increases the demand for reliable and high-performance computing. Current solutions have so far used the parity prediction scheme to increase reliability and detect fault in adder modules, but they add perceptible area overhead to the circuit. In this paper, we present two new efficient methods for fault detection and localization, in addition to the full error-correction, targeting stack-at and multi-cycle transient (MCT) faults in radix-2 signed-digit adders through a combination of time and hardware redundancy. In this study, we use the self-checking full adder that can identify a fault based on internal functionality to detect any, fault in the adder modules. The detection of a fault is followed by input inversion, recomputation, and appropriate output inversion to correct the error and localize the fault. The error correction method employs fault masking by utilizing the self-dual concept, which is based on the fact that in the presence of a fault, the designed technique results in a fault-free complement of the expected output when fed by the complement of its input operands. In addition, the existence of any fault in the input lines of the adder modules can be identified by low-cost parity checking error-detection approach, and a faulty module can be localized by comparing the faulty output from the first computation with the fault-free output from the recomputation. Based on the experimental results, the area occupied by our designs is approximately 50% that of the area used by previous designs that employ the parity prediction scheme. In addition to the area reduction, our design approaches result in a higher reliability with less power consumption and low time delay. (C) 2016 Elsevier Ltd. All rights reserved.</P>

Detection of Broken Bars in Induction Motors Using a Neural Network

Moradian M.,Ebrahimi M.,Danesh M.,Bayat M. The Korean Institute of Power Electronics 2006 JOURNAL OF POWER ELECTRONICS Vol.6 No.3

This paper presents a method based on neural networks to detect the broken rotor bars and end rings of squirrel cage induction motors. At first, detection methods are studied, and then traditional methods of fault detection and dynamic models of induction motors by using winding function model are introduced. In this method, all of the stator slots and rotor bars are considered, thus the performance of the motor in healthy situations or breakage in each part can be checked. The frequency spectrum of current signals is derived by using Fourier transformation and is analyzed in different conditions. In continuation, an analytical discussion and a simple algorithm are presented to detect the fault. This algorithm is based on neural networks. The neural network has been trained by using information of a 1.1 KW induction motor. This system has been tested with a different amount of load torque, and it is capable of working on-line and of recognizing all normal and ill conditions.

Sliding Mode Control of a New Wind-Based Isolated Three-Phase Induction Generator System with Constant Frequency and Adjustable Output Voltage

Moradian, Mohammadreza,Soltani, Jafar The Korean Institute of Power Electronics 2016 JOURNAL OF POWER ELECTRONICS Vol.16 No.2

This paper presents a new stand-alone wind-based induction generator system with constant frequency and adjustable output voltage. The proposed generator consists of a six-phase cage-rotor induction machine with two separate three-phase balanced stator windings and a three-phase space vector pulse width modulation inverter that operates as a static synchronous compensator (STATCOM). The first stator winding is fed by the STATCOM and used to excite the machine while the second stator winding is connected to the generator external load. The main frequency of the STATCOM is determined to be constant and equal to the load-requested frequency. The generator output frequency is independent of the load power demand and its prime mover speed because the frequency of the induced emf in the second stator winding is the same as this constant frequency. A sliding mode control (SMC) is developed to regulate the generator output voltage. A second SMC is used to force the zero active power exchanged between the machine and the STATCOM. Some simulation and experimental results are presented to prove the validity and effectiveness of the proposed generator system.

Advancing drag crisis of a sphere via the manipulation of integral length scale

Moradian, Niloofar,Ting, David S.K.,Cheng, Shaohong Techno-Press 2011 Wind and Structures, An International Journal (WAS Vol.14 No.1

Spherical object in wind is a common scenario in daily life and engineering practice. The main challenge in understanding the aerodynamics in turbulent wind lies in the multi-aspect of turbulence. This paper presents a wind tunnel study, which focuses on the role of turbulence integral length scale ${\Lambda}$ on the drag of a sphere. Particular turbulent flow conditions were achieved via the proper combination of wind speed, orifice perforated plate, sphere diameter (D) and distance downstream from the plate. The drag was measured in turbulent flow with $2.2{\times}10^4{\leq}Re{\leq}8{\times}10^4$, $0.043{\leq}{\Lambda}/D{\leq}3.24$, and turbulence intensity Tu up to 6.3%. Our results confirmed the general trends of decreasing drag coefficient and critical Reynolds number with increasing turbulence intensity. More interestingly, the unique role of the relative integral length scale has been revealed. Over the range of conditions studied, an integral length of approximately 65% the sphere diameter is most effective in reducing the drag.

Advancing drag crisis of a sphere via the manipulation of integral length scale

Niloofar Moradian,David S-K. Ting,Shaohong Cheng 한국풍공학회 2011 Wind and Structures, An International Journal (WAS Vol.14 No.1

Spherical object in wind is a common scenario in daily life and engineering practice. The main challenge in understanding the aerodynamics in turbulent wind lies in the multi aspect of turbulence. This paper presents a wind tunnel study, which focuses on the role of turbulence integral length scale Λ on the drag of a sphere. Particular turbulent flow conditions were achieved via the proper combination of wind speed, orifice perforated plate, sphere diameter (D) and distance downstream from the plate. The drag was measured in turbulent flow with 2.2 × 10^4 ≤ Re ≤ 8 × 10^4, 0.043 ≤ ∧/D ≤ 3.24, and turbulence intensity Tu up to 6.3%. Our results confirmed the general trends of decreasing drag coefficient and critical Reynolds number with increasing turbulence intensity. More interestingly, the unique role of the relative integral length scale has been revealed. Over the range of conditions studied, an integral length of approximately 65% the sphere diameter is most effective in reducing the drag.

Whole genome detection of recent selection signatures in Sarabi cattle: a unique Iranian taurine breed

Hasan Moradian,Ali Esmailizadeh Koshkoiyeh,Mohammadreza Mohammadabadi,Masood Asadi Fozi 한국유전학회 2020 Genes & Genomics Vol.42 No.2

Background The identification of genomic regions under selection can potentially permit a better understanding of the biology of the specific phenotypes which are useful for the development of tools designed to increase selection efficiency. Objective The aim of this study was to detect any traces of recent selection signatures as well as to identify corresponding genes and QTLs underlying these selection signatures in Sarabi cattle. Methods Samples from 20 animals were genotyped for 777,962 SNPs across the genome using the Illumina BovineHD BeadChip. Selection signatures analysis was performed using the integrated haplotype score (iHS) methodology. Results A total of eight significant regions (P < 0.0001) of possible recent selection signatures were detected on BTA14 and BTA17. In addition, nine genes were identified in regions harboring selection signatures, such as KCNQ3, HHLA1, OC90, EFR3A, ADCY8, ASAP1, TMEM132B, and TMEM132C. Study of the reported QTLs in these regions of the bovine genome has showed that they are associated with important traits such as milk, reproduction and production traits. Conclusion The results revealed multiple genomic regions as well as multiple new genes under positive selection on BTA14 and BTA17. Moreover, candidate selected regions that overlap with QTL reported in the cattle QTL database provided additional evidence for the significance of the detected regions under selection. This study provides a foundation for detailed analysis of the identified putative selection signatures in the cattle genome particularly of the indigenous and locally-developed cattle breeds and provides an avenue for a well-structured breed improvement.

Detection of Broken Bars in Induction Motors Using a Neural Network

M. Moradian,M. Ebrahimi,M. Danesh,M. bayat 전력전자학회 2006 JOURNAL OF POWER ELECTRONICS Vol.6 No.3

This paper presents a method based on neural networks to detect the broken rotor bars and end rings of squirrel cage induction motors. At first, detection methods are studied, and then traditional methods of fault detection and dynamic models of induction motors by using winding function model are introduced. In this method, all of the stator slots and rotor bars are considered, thus the performance of the motor in healthy situations or breakage in each part can be checked. The frequency spectrum of current signals is derived by using Fourier transformation and is analyzed in different conditions. In continuation, an analytical discussion and a simple algorithm are presented to detect the fault. This algorithm is based on neural networks. The neural network has been trained by using information of a 1.1 ㎾ induction motor. This system has been tested with a different amount of load torque, and it is capable of working on-line and of recognizing all normal and ill conditions.

SYNTHESIS AND CONTROL SIZE OF SnS2 NANOPARTICLES ON THE SURFACE MULTI-WALLED CARBON NANOTUBES

ROSTAM MORADIAN,BANDAR ASTINCHAP 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2010 NANO Vol.5 No.3

Multi-walled carbon nanotubes have been decorated by SnS2 nanoparticles with different sizes using a simple chemical method. In this work, first multi-walled carbon nanotubes (MWCNTs) functionalized by using acid mixture, then this system coated by tin disulfide (SnS2) nanoparticles with nanoparticle sizes controlling. The samples have been characterized by X-Ray diffraction and transmission electron microscopy (TEM). We found size and uniformity of the SnS2 nanoparticles influenced by increasing reaction temperature and time. By increasing reaction temperature and time, size of the SnS2 nanoparticles became larger and nonuniform. Also we found that ultrasound waves could be used instead of organic compounds for avoiding agglomeration of the SnS2 nanoparticles on the surface of MWCNTs.

Sliding Mode Control of a New Wind-Based Isolated Three-Phase Induction Generator System with Constant Frequency and Adjustable Output Voltage

Mohammadreza Moradian,Jafar Soltani 전력전자학회 2016 JOURNAL OF POWER ELECTRONICS Vol.16 No.2

This paper presents a new stand-alone wind-based induction generator system with constant frequency and adjustable output voltage. The proposed generator consists of a six-phase cage-rotor induction machine with two separate three-phase balanced stator windings and a three-phase space vector pulse width modulation inverter that operates as a static synchronous compensator (STATCOM). The first stator winding is fed by the STATCOM and used to excite the machine while the second stator winding is connected to the generator external load. The main frequency of the STATCOM is determined to be constant and equal to the load-requested frequency. The generator output frequency is independent of the load power demand and its prime mover speed because the frequency of the induced emf in the second stator winding is the same as this constant frequency. A sliding mode control (SMC) is developed to regulate the generator output voltage. A second SMC is used to force the zero active power exchanged between the machine and the STATCOM. Some simulation and experimental results are presented to prove the validity and effectiveness of the proposed generator system.

Efficient Low-Cost Fault-Localization and Self-Repairing Radix-2 Signed-Digit Adders Applying the Self-Dual Concept

Springer Science + Business Media 2017 Journal of signal processing systems Vol.88 No.3

<P>Signed-digit adder, which eliminates carry propagation chain, can execute addition operation independent of the length of operands, in constant time. The confined carry propagation implies remarkable advantage in terms of error detection, localization, and correction. We developed a new low-cost technique, for fault-localization and error-correction, which utilizes the self-dual concept in binary signed-digit adders. The foundational idea of our technique is that the designed method, when fed by the complement of its functional input under the existence of a stuck-at fault, yields a fault-free inverse of the expected output. In this method, after detection of a fault, the method continues with input inversion, recomputation, and desired output inversion. The faulty component will localize by comparison of the faulty and fault-free outputs. Higher reliability with less computational time and reduced hardware-area overhead are the distinct features of this new design. In this method, all of the single stuck-at faults can be localized and corrected, whereas previous approaches were unable to localize and correct with 100 % reliability even with longer time durations and greater hardware cost. The experimental results prove that our design requires 20 %-90 % less time and 20 %-40 % smaller area overhead compared with a previous related work.</P>