In this paper we apply computer visualization techniques such as computer (3D) graphics, animation, and photorealistic color rendering to the simulation of dynamical processes and control systems in limited-resource e...
详细信息
In this paper we present some enlightening results to show why and how stability assessment for Linear Time-Varying (LTV) systems based solely on the location of the "frozen-time eigenvalues (FTE)" fails to ...
详细信息
The application of higher-order spectral methods to certain multichannel inverse problems where the observed time signals are linear combinations of unknown sources is proposed. The transfer matrix is static and known...
详细信息
The application of higher-order spectral methods to certain multichannel inverse problems where the observed time signals are linear combinations of unknown sources is proposed. The transfer matrix is static and known beforehand but is highly ill-conditioned, leading to the failure of standard least squares regularization techniques or low rank approximation when there is additive noise. The noise suppression properties of third order cumulants are used, along with the ability to obtain multiple estimates by extracting individual signals from their third order cross-correlations via cross-bicepstrum operations. Variations of this approach are presented, and normalization issues are discussed.< >
The Miller effect is used to design resistively variable capacitors. The effect is formulated in voltage- and current-mode versions and, in both cases, implementation based on operational amplifiers and, eventually, c...
详细信息
The Miller effect is used to design resistively variable capacitors. The effect is formulated in voltage- and current-mode versions and, in both cases, implementation based on operational amplifiers and, eventually, current mirrors are suggested. Their dynamic range and frequency response are analyzed and compared introducing limitations of the active devices. The current-mode implementation seems to offer advantages in both parameters.< >
Priority service disciplines and congestion control schemes for voice and data multiplexing with bursty inputs in asynchronous transfer mode ATM/SONET broadband networks are presented. The authors consider dynamic map...
详细信息
Priority service disciplines and congestion control schemes for voice and data multiplexing with bursty inputs in asynchronous transfer mode ATM/SONET broadband networks are presented. The authors consider dynamic mapping of ATM cells in the SONET payload. They propose separate buffers for voice and data to efficiently control the throughput of each traffic type. Transmission bandwidth is dynamically shared between voice and data to guarantee grade of service (GOS) requirements for each traffic type. A selective voice cell discarding scheme is also considered for voice-data integration. The effects of voice cell discarding on network performance for integrated voice and data systems were analyzed by simulation. The results showed that the priority service disciplines, in combination with the voice cell discarding scheme, were very efficient methods to guarantee a GOS requirement for voice. The cell discarding scheme was shown to reduce cell losses as well as delays for data. It was found that the performance for data can be significantly improved by imposing the thresholds at both voice and data buffers.< >
An importance sampling (IS) methodology for Monte Carlo simulation of communication links characterized by time-varying channels and adaptive equalizers is presented. This methodology is denoted the twin system (TS). ...
详细信息
An importance sampling (IS) methodology for Monte Carlo simulation of communication links characterized by time-varying channels and adaptive equalizers is presented. This methodology is denoted the twin system (TS). A key feature of the TS is that biased noise samples are input to the adaptive equalizer, but the equalizer is only allowed to adapt to these samples for a time interval equal to the memory of the system. Experimental results are presented that show runtime speed-up factors of three to six orders of magnitude for a static linear channel with memory, and of four to nine orders of magnitude for a slowly varying, random linear channel with memory.< >
The authors develop an optimization scheme based on mean field theory (MFT) to solve the task scheduling problem. The algorithm combines characteristics of the simulated annealing (SA) algorithm and the Hopfield neura...
详细信息
The authors develop an optimization scheme based on mean field theory (MFT) to solve the task scheduling problem. The algorithm combines characteristics of the simulated annealing (SA) algorithm and the Hopfield neural network. The temperature behavior of MFT for the task scheduling problem is shown to possess a critical temperature below which an optimal solution may be achieved. The algorithm has been applied to various task graphs, and promising results have been obtained.< >
The authors extend the previously reported three structures of bootstrap blind adaptive separators to the multisignal channel case. They suggest a recursive weight updating algorithm for the three structures: power-po...
详细信息
The authors extend the previously reported three structures of bootstrap blind adaptive separators to the multisignal channel case. They suggest a recursive weight updating algorithm for the three structures: power-power, correlator-correlator, and power-correlator. The optimum weights for these separators were found analytically in the absence of noise. The signal separation process was shown via simulation by the output learning curve. It was shown that the different bootstrap separators converge to their steady states almost with the same speed for a two or three signal channel. The steady-state interference residues of the three separators are different, lowest for power-power and highest for correlator-correlator. The use of equalization (automatic gain control) at the output of these structures improves the depth of interference cancellation dramatically.< >
A generalized, parametric PR-QMF (perfect reconstruction quadrature mirror filter) design technique based on the Bernstein polynomial approximation is developed. The parametric nature of this solution provides very us...
详细信息
A generalized, parametric PR-QMF (perfect reconstruction quadrature mirror filter) design technique based on the Bernstein polynomial approximation is developed. The parametric nature of this solution provides very useful insights into the PR-QMF problem. Several well-known orthonormal wavelet filters, PR-QMFs, are shown to be the special cases of the proposed technique. The energy compaction performance of a few popular signal decomposition techniques is presented for AR(1) signal sources. It is shown that the QMF filter banks considered here outperform the block transforms, as expected.< >
暂无评论