Browsing by Author "Singh, Vimal"

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Citation - WoS: 5
Citation - Scopus: 5
2-D Digital Filter Realization Without Overflow Oscillations
(Pergamon-elsevier Science Ltd, 2013) Singh, Vimal; Department of Mechatronics Engineering
A novel criterion for the elimination of overflow oscillations in 2-D state-space digital filters described by the Roesser model employing two's complement overflow arithmetic is presented. The criterion takes the form of linear matrix inequality (LMI) and, hence, is computationally tractable. The criterion is a generalization and improvement over an earlier criterion. An example shows the effectiveness of the new criterion. (C) 2012 Elsevier Ltd. All rights reserved.
Citation - WoS: 4
Citation - Scopus: 4
Author's Reply To "comments on 'modified Criterion for Global Asymptotic Stability of Fixed-Point State-Space Digital Filters Using Two's Complement Arithmetic [automatica 46 (2010) 475-478]'"
(Pergamon-elsevier Science Ltd, 2010) Singh, Vimal; Department of Mechatronics Engineering
[No Abstract Available]
Comment On: "dynamical Analysis of Cohen-Grossberg Neural Networks With Distributed Delays" [phys. Lett. a 364 (2007) 38]
(Elsevier Science Bv, 2008) Singh, Vimal; Sıngh, Vımal; Sıngh, Vımal; Department of Mechatronics Engineering; Department of Mechatronics Engineering
It is pointed out that an unnatural assumption is made in the following Letter [Z. Mao, H. Zhao, Phys. Lett. A 364 (1) (2007) 38). Therefore, the results of the Letter are not relevant to the real Cohen-Grossberg neural network model. (C) 2008 Elsevier B.V. All rights reserved.
Citation - WoS: 33
Citation - Scopus: 36
Discussion on Barkhausen and Nyquist Stability Criteria
(Springer, 2010) Singh, Vimal; Department of Mechatronics Engineering
Most textbooks on analog circuits and signal processing describe the Barkhausen criterion pertaining to the determination of sinusoidal oscillations in a closed-loop system. On the other hand, the Nyquist stability criterion is well known, as discussed in most textbooks on control systems. Recently, some examples in which the Barkhausen criterion fails to produce the correct condition for startup of oscillations have been reported. In the present paper, an explanation of oscillation startup based on the Nyquist stability criterion is given and the close relationship between the Barkhausen and the Nyquist criteria highlighted. It is shown that the Nyquist criterion (which is a rigorous technique) is a more robust approach than the Barkhausen criterion concerning the determination of sinusoidal oscillations in a closed-loop system and that the Barkhausen criterion (whenever it yields the correct result) is subsumed by the Nyquist criterion as a special case. The textbooks usually describe the Barkhausen criterion as a separate topic, i.e., do not discuss the relationship of this criterion with the Nyquist criterion. It is, therefore, felt that the present discussion will go a long way to put the subject in a broader perspective.
Citation - WoS: 1
Citation - Scopus: 1
Elimination of Limit Cycles in a Class of Digital Filters Using Single Saturation Nonlinearity
(Taylor & Francis Ltd, 2008) Singh, Vimal; Department of Mechatronics Engineering
Using Lyapunov's direct method, a novel frequency-domain criterion for the elimination of limit cycles in a class of digital filters using single saturation nonlinearity is derived. The criterion turns out to be a generalization and improvement over an earlier criterion due to Kar and Singh. An example showing the effectiveness of the criterion is given. A graphical interpretation of a simplified version (involving one free parameter) of the criterion is discussed.
Citation - WoS: 16
Citation - Scopus: 16
Elimination of Overflow Oscillations in Direct Form Digital Filters Using Saturation Arithmetic
(Pergamon-elsevier Science Ltd, 2008) Singh, Vimal; Department of Mechatronics Engineering
A novel frequency-domain criterion for the elimination of limit cycles in a class of digital filters using saturation arithmetic is presented. An example showing the effectiveness of the present criterion is given. (C) 2008 Elsevier Ltd. All rights reserved.
Citation - WoS: 22
Citation - Scopus: 25
Failure of Barkhausen Oscillation Building Up Criterion: Further Evidence
(Springer, 2007) Singh, Vimal; Department of Mechatronics Engineering
It has been suggested in many textbooks that, given a closed-loop system, oscillation will commence and build up therein if the magnitude of loop gain is greater than unity at the frequency at which the angle of loop gain is zero degree. A novel ideal op-amp based counterexample to this suggestion is presented. The Letter serves to substantiate the findings in a recent Letter. A discussion relating to the finite gain of op-amp is included.
Citation - WoS: 14
Citation - Scopus: 15
Global asymptotic stability of 2-D state-space digital filters with saturation arithmetic: Modified approach
(Elsevier Science Bv, 2008) Singh, Vimal; Department of Mechatronics Engineering
A criterion for the global asymptotic stability of 2-D state-space digital filters described by the Roesser model employing state saturation arithmetic is presented. The criterion is a modified form of a recently reported criterion. An example shows the effectiveness of the modified criterion. (C) 2007 Elsevier B.V. All rights reserved.
Citation - WoS: 5
Citation - Scopus: 7
Global Asymptotic Stability of Neural Networks With Delay: Comparative Evaluation of Two Criteria
(Pergamon-elsevier Science Ltd, 2007) Singh, Vimal; Department of Mechatronics Engineering
In [IEEE Trans Cire Syst II 2005;52(4):181-4], a criterion for the global asymptotic stability of a class of delayed neural networks has been presented. The criterion is based on the factorization B = B(1)B(2), where B denotes the delayed connection weight matrix. In the present paper, this criterion is compared with the criterion reported in [Phys Lett A 2003;311(6):504-11]. It turns out that, as far as the case of a nonsingular matrix B, is concerned, these two criteria are one and the same. (c) 2006 Elsevier Ltd. All rights reserved.
Citation - WoS: 53
Citation - Scopus: 61
Global Robust Stability of Delayed Neural Networks: Estimating Upper Limit of Norm of Delayed Connection Weight Matrix
(Pergamon-elsevier Science Ltd, 2007) Singh, Vimal; Department of Mechatronics Engineering
The question of estimating the upper limit of parallel to B parallel to(2), which is a key step in some recently reported global robust stability criteria for delayed neural networks, is revisited (B denotes the delayed connection weight matrix). Recently, Cao, Huang, and Qu have given an estimate of the upper limit of parallel to B parallel to(2). In the present paper, an alternative estimate of the upper limit of parallel to B parallel to(2) is highlighted. It is shown that the alternative estimate may yield some new global robust stability results. (c) 2005 Elsevier Ltd. All rights reserved.
Citation - WoS: 3
Citation - Scopus: 3
Global Robust Stability of Interval Delayed Neural Networks: Modified Approach
(Wiley, 2009) Singh, Vimal; Department of Mechatronics Engineering
A criterion for the global robust stability of Hopfield-type delayed neural networks with the intervalized network parameters is presented. The criterion, which is derived by utilizing the idea of splitting the given interval into two intervals, is in the form of linear matrix inequality and, hence, computationally tractable. The criterion yields a less conservative condition compared with many recently reported criteria, as is demonstrated with an example. Copyright (C) 2008 John Wiley & Sons, Ltd.
Citation - WoS: 33
Citation - Scopus: 36
Improved Criterion for Global Asymptotic Stability of 2-D Discrete Systems With State Saturation
(Ieee-inst Electrical Electronics Engineers inc, 2007) Singh, Vimal; Department of Mechatronics Engineering
A criterion for the global asymptotic stability of 2-D discrete systems described by the Roesser model employing state saturation arithmetic is presented. A comparison of the present criterion with the previous criteria and an illustrative example showing the effectiveness of the present criterion are given.
Citation - WoS: 23
Citation - Scopus: 22
Improved Global Robust Stability Criterion for Delayed Neural Networks
(Pergamon-elsevier Science Ltd, 2007) Singh, Vimal; Department of Mechatronics Engineering
A criterion for the uniqueness and global robust stability of the equilibrium point of interval Hopfield-type delayed neural networks is presented. The criterion is a marked improvement over a recent criterion due to Cao, Huang and Qu. (c) 2005 Elsevier Ltd. All rights reserved.
Citation - WoS: 13
Citation - Scopus: 14
Improved Global Robust Stability for Interval-Delayed Hopfield Neural Networks
(Springer, 2008) Singh, Vimal; Department of Mechatronics Engineering
A modified form of a recent criterion for the global robust stability of interval-delayed Hopfield neural networks is presented. The effectiveness of the modified criterion is demonstrated with the help of an example.
Citation - WoS: 15
Citation - Scopus: 17
Improved Global Robust Stability of Interval Delayed Neural Networks Via Split Interval: Generalizations
(Elsevier Science inc, 2008) Singh, Vimal; Department of Mechatronics Engineering
dThe problem of global robust stability of Hop field-type delayed neural networks with the intervalized network parameters is revisited. Recently, a computationally tractable, i.e., linear matrix inequality (LMI) based global robust stability criterion derived from an earlier criterion based on dividing the given interval into more that two intervals has been presented. In the present paper, generalizations, i.e., division of the given interval into m intervals (where m is an integer greater than or equal to 2) is considered and some new LMI-based global robust stability criteria are derived. It is shown that, in some cases, m = 2 may not suffice, i.e., m > 2 may be needed to realize the improvement. An example showing the effectiveness of the proposed generalization is given. The paper also provides a complete and systematic explanation of the "split interval" idea. (c) 2008 Elsevier Inc. All rights reserved.
Citation - WoS: 19
Citation - Scopus: 22
Improved Lmi-Based Criterion for Global Asymptotic Stability of 2-D State-Space Digital Filters Described by Roesser Model Using Two's Complement Arithmetic
(Academic Press inc Elsevier Science, 2012) Singh, Vimal; Department of Mechatronics Engineering
An LMI-based criterion for the global asymptotic stability of 2-D state-space digital filters described by the Roesser model employing two's complement overflow arithmetic is presented. Under a certain assumption, the criterion turns out to be an improvement over a criterion due to El-Agizi and Fahmy pertaining to two's complement arithmetic and has a form similar to a criterion due to Xiao and Hill pertaining to saturation arithmetic. Examples show the effectiveness of the new criterion. (C) 2012 Elsevier Inc. All rights reserved.
Citation - WoS: 2
Citation - Scopus: 4
Improved State-Space Criteron for Global Asymptotic Stability of Fixed-Point State-Space Digital Filters With Saturation Arithmetic
(King Fahd Univ Petroleum Minerals, 2007) Singh, Vimal; Department of Mechatronics Engineering; Department of Mechatronics Engineering
A state-space criterion for the global asymptotic stability of fixed-point state-space digital filters using saturation overflow arithmetic is presented. The criterion is derived by exploiting a novel structural property of the system under consideration and, hence, is quite distinct from the previous criteria. In particular, a comparison of the present criterion with an earlier criterion due to Kar and Singh is made. The comparison reveals that the present criterion is less restrictive than Kar-Singh's criterion. Two examples showing the effectiveness of the present approach are given.
Citation - WoS: 5
Citation - Scopus: 7
Lmi Approach To Stability of a Class of Discrete-Time Systems Using Two's Complement Arithmetic
(Elsevier Science inc, 2010) Singh, Vimal; Department of Mechatronics Engineering
systematic and computationally tractable (i.e., linear matrix inequality based) approach to the global asymptotic stability of a class of discrete-time systems, implemented with fixed-point arithmetic, utilizing a very strong nonlinearity (which is produced by employing two's complement overflow arithmetic) is presented. Application of the approach to second-order digital filter is discussed. Two third-order examples illustrating the effectiveness of the approach are given. (C) 2010 Elsevier Inc. All rights reserved.
Citation - WoS: 24
Citation - Scopus: 25
Lmi Approach To Stability of Direct Form Digital Filters Utilizing Single Saturation Overflow Nonlinearity
(Ieee-inst Electrical Electronics Engineers inc, 2007) Singh, Vimal; Department of Mechatronics Engineering
A criterion for the elimination of limit cycles in direct form digital filters utilizing single saturation overflow nonlinearity is presented. The criterion takes the form of linear matrix inequality and, hence, is computationally tractable. An example showing the effectiveness of the present criterion is given.
Citation - WoS: 14
Citation - Scopus: 15
Lmi Approach To the Global Robust Stability of a Larger Class of Neural Networks With Delay
(Pergamon-elsevier Science Ltd, 2007) Singh, Vimal; Department of Mechatronics Engineering
Sufficient conditions in the form of linear matrix inequality for the uniqueness and global asymptotic stability of the equilibrium point of a large class of uncertain neural networks with delay are presented. The conditions are based on norm-bounded uncertainties. An example is given to show the effectiveness of the obtained results. A comparison is made between the present approach and an earlier approach due to Lu, Rong and Chen. An error is corrected in an earlier publication. (c) 2006 Elsevier Ltd. All rights reserved.