Victor Sreeram - Academia.edu (original) (raw)
Papers by Victor Sreeram
In sensor networks, linear regression has been applied over a set of sending-receiving timestamps... more In sensor networks, linear regression has been applied over a set of sending-receiving timestamps to estimate the clock-skew, assuming a time-invariant propagation delay of the beacons exchanged between the nodes. Due to ocean currents and dispersion, propagation delay between underwater nodes is time-varying. In this paper, we first analyze the effect of time-varying propagation on synchronization performance, demonstrating that the
2011 8th International Conference on Information, Communications & Signal Processing, 2011
In sensor networks, linear regression has been applied over a set of sending-receiving timestamps... more In sensor networks, linear regression has been applied over a set of sending-receiving timestamps to estimate the clock-skew, assuming a time-invariant propagation delay of the beacons exchanged between the nodes. Due to ocean currents and dispersion, propagation delay between underwater nodes is time-varying. In this paper, we first analyze the effect of time-varying propagation on synchronization performance, demonstrating that the
2012 International Symposium on Communications and Information Technologies (ISCIT), 2012
ABSTRACT To achieve time synchronization in underwater networks, a linear regression is often app... more ABSTRACT To achieve time synchronization in underwater networks, a linear regression is often applied over a set of sending-receiving timestamps, assuming the participating timestamps are consistent. In this paper, we show that collisions, which are not uncommon during signal exchange in underwater environment, would lead to inconsistent timestamps. These inconsistent timestamps are outliers. However, existing synchronization approaches ignore the presence of outliers. To obtain a reliable synchronization, we propose a robust algorithm that identifies and eliminates the outliers by employing Cook's distance before applying linear regression. We justify the proposed algorithm in a mobile underwater environment through extensive simulations.
IEEE Transactions on Communications, 1998
Abstract Clock-rate adaptation circuits of network synchronizers work by controlling the output d... more Abstract Clock-rate adaptation circuits of network synchronizers work by controlling the output data rate by pulse stuffing. The technique of stuff threshold modulation (ST-Mod) is one method used to reduce the waiting time jitter produced by pulse stuffing. An ...
IEEE Transactions on Communications, 1998
Abstract Clock-rate adaptation circuits of network synchronizers work by controlling the output d... more Abstract Clock-rate adaptation circuits of network synchronizers work by controlling the output data rate by pulse stuffing. The technique of stuff threshold modulation (ST-Mod) is one method used to reduce the waiting time jitter produced by pulse stuffing. An ...
International Journal of Electrical Power & Energy Systems
In this paper, a computationally efficient frequencylimited model reduction algorithm is presente... more In this paper, a computationally efficient frequencylimited model reduction algorithm is presented for large-scale interconnected power systems. The algorithm generates a reduced order model which not only preserves the electromechanical modes of the original power system but also satisfies a subset of the first-order optimality conditions for H2,ω model reduction problem within the desired frequency interval. The reduced order model accurately captures the oscillatory behavior of the original power system and provides a good time-and frequency-domain accuracy. The proposed algorithm enables fast simulation, analysis, and damping controller design for the original large-scale power system. The efficacy of the proposed algorithm is validated on benchmark power system examples.
Abstract We consider digital signal processor (DSP) based inphase/quadrature (IQ) modulators gene... more Abstract We consider digital signal processor (DSP) based inphase/quadrature (IQ) modulators generating continuous phase frequency shift keying (CPFSK) signals. Departures from a flat-magnitude, linear phase frequency response in the pass bands of ...
This paper considers mean-square exponential stability and H ∞ control problems for Markovian jum... more This paper considers mean-square exponential stability and H ∞ control problems for Markovian jump systems (MJSs) with time delays which are time-varying in an interval and depend on system mode. By exploiting a novel Lyapunov-Krasovskii functional which takes into account the range of delay, and by making use of some techniques, new delay-range-dependent stability result and bounded real lemma for MJSs are obtained, where the introduction of the lower bound of delay is shown to be advantageous for reducing conservatism. Moreover, a sufficient condition for the solvability of the H ∞ control problem is derived in terms of linear matrix inequalities. Finally, illustrative examples are presented to show the advantage and effectiveness of the proposed approaches.
Consider a continuous-time filter the structure of which is comprised of an A/D converter, an FIR... more Consider a continuous-time filter the structure of which is comprised of an A/D converter, an FIR filter, a D/A converter and an analog post-filter. The envelope constrained (EC) filtering problem for this filter structure is to design the digital component so as to minimize the effect of the input noise whilst satisfying the constraint that the noiseless response of the filter to a specified excitation fits into a prescribed envelope.
IEEE Transactions on Communications, 1998
Abstract Clock-rate adaptation circuits of network synchronizers work by controlling the output d... more Abstract Clock-rate adaptation circuits of network synchronizers work by controlling the output data rate by pulse stuffing. The technique of stuff threshold modulation (ST-Mod) is one method used to reduce the waiting time jitter produced by pulse stuffing. An ...
In sensor networks, linear regression has been applied over a set of sending-receiving timestamps... more In sensor networks, linear regression has been applied over a set of sending-receiving timestamps to estimate the clock-skew, assuming a time-invariant propagation delay of the beacons exchanged between the nodes. Due to ocean currents and dispersion, propagation delay between underwater nodes is time-varying. In this paper, we first analyze the effect of time-varying propagation on synchronization performance, demonstrating that the
2011 8th International Conference on Information, Communications & Signal Processing, 2011
In sensor networks, linear regression has been applied over a set of sending-receiving timestamps... more In sensor networks, linear regression has been applied over a set of sending-receiving timestamps to estimate the clock-skew, assuming a time-invariant propagation delay of the beacons exchanged between the nodes. Due to ocean currents and dispersion, propagation delay between underwater nodes is time-varying. In this paper, we first analyze the effect of time-varying propagation on synchronization performance, demonstrating that the
2012 International Symposium on Communications and Information Technologies (ISCIT), 2012
ABSTRACT To achieve time synchronization in underwater networks, a linear regression is often app... more ABSTRACT To achieve time synchronization in underwater networks, a linear regression is often applied over a set of sending-receiving timestamps, assuming the participating timestamps are consistent. In this paper, we show that collisions, which are not uncommon during signal exchange in underwater environment, would lead to inconsistent timestamps. These inconsistent timestamps are outliers. However, existing synchronization approaches ignore the presence of outliers. To obtain a reliable synchronization, we propose a robust algorithm that identifies and eliminates the outliers by employing Cook's distance before applying linear regression. We justify the proposed algorithm in a mobile underwater environment through extensive simulations.
IEEE Transactions on Communications, 1998
Abstract Clock-rate adaptation circuits of network synchronizers work by controlling the output d... more Abstract Clock-rate adaptation circuits of network synchronizers work by controlling the output data rate by pulse stuffing. The technique of stuff threshold modulation (ST-Mod) is one method used to reduce the waiting time jitter produced by pulse stuffing. An ...
IEEE Transactions on Communications, 1998
Abstract Clock-rate adaptation circuits of network synchronizers work by controlling the output d... more Abstract Clock-rate adaptation circuits of network synchronizers work by controlling the output data rate by pulse stuffing. The technique of stuff threshold modulation (ST-Mod) is one method used to reduce the waiting time jitter produced by pulse stuffing. An ...
International Journal of Electrical Power & Energy Systems
In this paper, a computationally efficient frequencylimited model reduction algorithm is presente... more In this paper, a computationally efficient frequencylimited model reduction algorithm is presented for large-scale interconnected power systems. The algorithm generates a reduced order model which not only preserves the electromechanical modes of the original power system but also satisfies a subset of the first-order optimality conditions for H2,ω model reduction problem within the desired frequency interval. The reduced order model accurately captures the oscillatory behavior of the original power system and provides a good time-and frequency-domain accuracy. The proposed algorithm enables fast simulation, analysis, and damping controller design for the original large-scale power system. The efficacy of the proposed algorithm is validated on benchmark power system examples.
Abstract We consider digital signal processor (DSP) based inphase/quadrature (IQ) modulators gene... more Abstract We consider digital signal processor (DSP) based inphase/quadrature (IQ) modulators generating continuous phase frequency shift keying (CPFSK) signals. Departures from a flat-magnitude, linear phase frequency response in the pass bands of ...
This paper considers mean-square exponential stability and H ∞ control problems for Markovian jum... more This paper considers mean-square exponential stability and H ∞ control problems for Markovian jump systems (MJSs) with time delays which are time-varying in an interval and depend on system mode. By exploiting a novel Lyapunov-Krasovskii functional which takes into account the range of delay, and by making use of some techniques, new delay-range-dependent stability result and bounded real lemma for MJSs are obtained, where the introduction of the lower bound of delay is shown to be advantageous for reducing conservatism. Moreover, a sufficient condition for the solvability of the H ∞ control problem is derived in terms of linear matrix inequalities. Finally, illustrative examples are presented to show the advantage and effectiveness of the proposed approaches.
Consider a continuous-time filter the structure of which is comprised of an A/D converter, an FIR... more Consider a continuous-time filter the structure of which is comprised of an A/D converter, an FIR filter, a D/A converter and an analog post-filter. The envelope constrained (EC) filtering problem for this filter structure is to design the digital component so as to minimize the effect of the input noise whilst satisfying the constraint that the noiseless response of the filter to a specified excitation fits into a prescribed envelope.
IEEE Transactions on Communications, 1998
Abstract Clock-rate adaptation circuits of network synchronizers work by controlling the output d... more Abstract Clock-rate adaptation circuits of network synchronizers work by controlling the output data rate by pulse stuffing. The technique of stuff threshold modulation (ST-Mod) is one method used to reduce the waiting time jitter produced by pulse stuffing. An ...