We present a methodology for designing a dynamic controller with delayed output feedback for achieving non-collocated vibration suppression with a focus on the multi-frequency case. To synthesize the delay-based contr...
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We present a methodology for designing a dynamic controller with delayed output feedback for achieving non-collocated vibration suppression with a focus on the multi-frequency case. To synthesize the delay-based controller, we first remodel the system of equations as a delay-differential algebraic equation (DDAE) in such a way that existing tools for design of a static output feedback controller can be easily adapted. The problem of achieving non-collocated vibration suppression with sufficient damping is formulated as a constrained optimization problem of minimizing the spectral abscissa in the presence of zero-location constraints, with the constraints exhibiting polynomial dependence on its parameters. We transform the problem into an unconstrained one using elimination, following which we solve the resulting non-convex, non-smooth optimization problem.
Heterogeneous networks (HetNets) are considered a promising cellular network architecture to provide services to the massive number of subscribers. However, in heterogeneous networks, as cell size becomes smaller, the...
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ISBN:
(纸本)9781538605295
Heterogeneous networks (HetNets) are considered a promising cellular network architecture to provide services to the massive number of subscribers. However, in heterogeneous networks, as cell size becomes smaller, the number of handovers and handover failure increase significantly. Therefore, mobility management becomes an important issue in HetNets. In this research, we analyzed the handover parameters, and proposed a novel handover method for heterogeneous cellular networks to minimize the number of handovers and handover failure. In the proposed method, we considered dual connectivity with control and data plane split and Coordinated Multipoint (CoMP) transmission to optimize the handover parameters. The reduction of handover improves the network performance and the handover failure reduction improves the user experience. The simulation results show that the proposed handover process significantly reduces the number of handovers in heterogeneous cellular networks.
The analysis of a combined multicarrier modulation/direct-sequence spread-spectrum (DSSS) modem carried out by Kondo and Milstein (see IEEE Trans. on Commun., 1995) in delay spread multipath is extended to include the...
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The analysis of a combined multicarrier modulation/direct-sequence spread-spectrum (DSSS) modem carried out by Kondo and Milstein (see IEEE Trans. on Commun., 1995) in delay spread multipath is extended to include the effect of correlation between the DSSS subcarriers due to an exponential power delay profile. Analytical and simulation results show that additional diversity gain can be achieved with more subcarriers, but at the expense of multiple access capability. Eventually, an irreducible bit error probability (BEP) is approached as more subcarriers are used.
In this paper, we propose a Markov Chain Monte Carlo (MCMC) algorithm to handle fog nodes coalition formation problem. The need to construct coalitions emanates from the fact that some nodes could not be able to handl...
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In this paper, we propose a Markov Chain Monte Carlo (MCMC) algorithm to handle fog nodes coalition formation problem. The need to construct coalitions emanates from the fact that some nodes could not be able to handle the required computation on its own due to their limited computational capabilities. Also, we introduce a set of constraints on the formed coalitions. Specifically, nodes could have preferences with whom to coalesce. Even more the formed coalitions have to be of semi-equal computational powers.
Structure extraction is important for human perception. However, for various textured images, computers can hardly achieve this goal. Despite a plethora of studies to address the challenge, results from most previous ...
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Structure extraction is important for human perception. However, for various textured images, computers can hardly achieve this goal. Despite a plethora of studies to address the challenge, results from most previous methods contain unwanted artifacts and over-smoothed structures. Therefore, to address the weaknesses, we have proposed a variational model with end-to-end contour learning capability. Our formulation dwells in two observations: likelihood for representation of residual textures may be well abstracted using super Gaussian distribution, and edge metrics with semantic meaning may benefit structure preservation. The augmented Lagrangian method is adopted for optimal computation. Compared with classical approaches, our method offers a higher performance in structure extraction, including situations where the images have significant non-uniformity of the scale features.
We present an analysis of the effect of FEC on energy consumption of VCSEL based transmitters for short-range optical links. We show that a low-complexity FEC can reduce the overall energy consumption of the transmitter.
We present an analysis of the effect of FEC on energy consumption of VCSEL based transmitters for short-range optical links. We show that a low-complexity FEC can reduce the overall energy consumption of the transmitter.
We investigate non-parametric identification of the frequency dependent complex modulus of a viscoelastic material, using a non-equilibrium split Hopkinson pressure bar technique. Three different procedures for estima...
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We investigate non-parametric identification of the frequency dependent complex modulus of a viscoelastic material, using a non-equilibrium split Hopkinson pressure bar technique. Three different procedures for estimating the complex modulus from experimental data are considered, and an analysis of the quality of the estimates is carried out. The validity of the theoretical results are confirmed by numerical studies and experimental tests.
Repetitive processes are a distinct class of 2D systems of both theoretical and applications interest. They are characterized by a series of sweeps through a set of dynamics with explicit interaction between the outpu...
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Repetitive processes are a distinct class of 2D systems of both theoretical and applications interest. They are characterized by a series of sweeps through a set of dynamics with explicit interaction between the outputs, or pass profiles, produced on successive passes. Their essential unique features are that (i) information propagation is over a finite duration in one of the two separate directions of information propagation; and (ii) the explicit interaction between successive pass profiles can lead to oscillations in the sequence of pass profiles that increase in amplitude in the pass to pass direction. In the case of processes with linear dynamics (either differential or discrete) a reasonably rich systems theory is available for models which are standard (or nonsingular). In this paper, we provide the first substantial results on discrete linear repetitive processes described by a singular state space model.
A generally applicable design of non-collocated vibration absorption by a delayed resonator is proposed. It is grounded in the direct assignment of imaginary axis zeros of the transfer function between the periodic di...
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A generally applicable design of non-collocated vibration absorption by a delayed resonator is proposed. It is grounded in the direct assignment of imaginary axis zeros of the transfer function between the periodic disturbance force and the target. We show that these transmission zeros are characterized as eigenvalues of a delay differential-algebraic system. Furthermore, a stabilizing local controller is added to the setup in order to widen the range of admissible vibration frequencies. These design requirements are translated into an optimization problem of the spectral abscissa function subjected to zero location constraints. The presented approach and algorithm are validated by a simulation on a three body lumped mass-spring system.
DC-link decoupling capacitors are generally placed near the power switches in the converter to minimize the parasitic ringing and voltage overshoot on the devices. In this paper, the influence of decoupling capacitors...
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ISBN:
(纸本)9781479903375
DC-link decoupling capacitors are generally placed near the power switches in the converter to minimize the parasitic ringing and voltage overshoot on the devices. In this paper, the influence of decoupling capacitors on the turn-off parasitic ringing of power MOSFETs is studied in the frequency domain based on a small-signal modeling approach. This new angle helps explain the effect of these capacitors in a simpler and more straightforward way compared to the traditional time-domain analysis, and provides a deeper insight into the problem. A rule of thumb about the selection of effective decoupling capacitance value can also be derived from this study.
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