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81
AirWater Flows down Stepped chutes : Turbulence and Flow Structure Observations." Intl Jl of Multiphase Flow
 ISSN 03019322). Page
, 2002
"... Abstract: Interactions between turbulent waters and atmosphere may lead to strong airwater mixing. This experimental study is focused on the flow down a staircase channel characterised by very strong flow aeration and turbulence. Interfacial aeration is characterised by strong airwater mixing exte ..."
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Cited by 37 (22 self)
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Abstract: Interactions between turbulent waters and atmosphere may lead to strong airwater mixing. This experimental study is focused on the flow down a staircase channel characterised by very strong flow aeration and turbulence. Interfacial aeration is characterised by strong airwater mixing extending down to the invert. The size of entrained bubbles and droplets extends over several orders of magnitude, and a significant number of bubble/droplet clusters was observed. Velocity and turbulence intensity measurements suggest high levels of turbulence across the entire airwater flow. The increase in turbulence levels, compared to singlephase flow situations, is proportional to the number of entrained particles.
Bayesian classification with correlation and inheritance
 In Proceedings of the 12th International Joint Conference on Artificial Intelligence
, 1991
"... The task of inferring a set of classes and class descriptions most likely to explain a given data set can be placed on a firm theoretical foundation using Bayesian statistics. Within this framework, and using various mathematical and algorithmic approximations, the AutoClass system searches for the ..."
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Cited by 34 (2 self)
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The task of inferring a set of classes and class descriptions most likely to explain a given data set can be placed on a firm theoretical foundation using Bayesian statistics. Within this framework, and using various mathematical and algorithmic approximations, the AutoClass system searches for the most probable classifications, automatically choosing the number of classes and complexity of class descriptions. Simpler versions of AutoClass have been applied to many large real data sets, have discovered new independentlyverified phenomena, and have been released as a robust software package. Recent extensions allow attributes to be selectively correlated within particular classes, and allow classes to inherit, or share, model parameters though a class hierarchy. 1
Analysis and Design of Oscillatory Control Systems
, 2003
"... This paper presents analysis and design results for control systems subject to oscillatory inputs, i.e., inputs of large amplitude and high frequency. The key analysis results are a series expansion characterizing the averaged system and various Liealgebraic conditions that guarantee the series can ..."
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Cited by 18 (5 self)
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This paper presents analysis and design results for control systems subject to oscillatory inputs, i.e., inputs of large amplitude and high frequency. The key analysis results are a series expansion characterizing the averaged system and various Liealgebraic conditions that guarantee the series can be summed. Various example systems provide insight into the results. With regards to design, we recover and extend a variety of point stabilization and trajectory tracking results using oscillatory controls. We present novel developments on stabilization of systems with positive trace and on tracking for second order underactuated systems.
Fast Numerical Integration of Relaxation Oscillator Networks Based on Singular Limit Solutions
 IEEE Transactions on Neural Networks
, 1998
"... Relaxation oscillations exhibiting more than one time scale arise naturally from many physical systems. This paper proposes a method to numerically integrate large systems of relaxation oscillators. The numerical technique, called the singular limit method, is derived from analysis of relaxation osc ..."
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Cited by 17 (9 self)
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Relaxation oscillations exhibiting more than one time scale arise naturally from many physical systems. This paper proposes a method to numerically integrate large systems of relaxation oscillators. The numerical technique, called the singular limit method, is derived from analysis of relaxation oscillations in the singular limit. In such limit, system evolution gives rise to time instants at which fast dynamics takes place and intervals between them during which slow dynamics takes place. A full description of the method is given for LEGION (locally excitatory globally inhibitory oscillator networks), where fast dynamics, characterized by jumping which leads to dramatic phase shifts, is captured in this method by iterative operation and slow dynamics is entirely solved. The singular limit method is evaluated by computer experiments, and it produces remarkable speedup compared to other methods of integrating these systems. The speedup makes it possible to simulate largescale oscillato...
SNR estimation in time varying fading channels
 IEEE Trans. Commun
, 2006
"... Abstract—Signaltonoise ratio (SNR) estimation is considered for phaseshift keying communication systems in timevarying fading channels. Both dataaided (DA) estimation and nondataaided (NDA) estimation are addressed. The timevarying fading channel is modeled as a polynomialintime. Inherent ..."
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Cited by 15 (0 self)
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Abstract—Signaltonoise ratio (SNR) estimation is considered for phaseshift keying communication systems in timevarying fading channels. Both dataaided (DA) estimation and nondataaided (NDA) estimation are addressed. The timevarying fading channel is modeled as a polynomialintime. Inherent estimation accuracy limitations are examined via the Cramer–Rao lower bound, where it is shown that the effect of the channel’s time variation on SNR estimation is negligible. A novel maximumlikelihood (ML) SNR estimator is derived for the timevarying channel model. In DA scenarios, where the estimator has a simple closedform solution, the exact performance is evaluated both with correct and incorrect (i.e., mismatched) polynomial order. In NDA estimation, the unknown data symbols are modeled as random, and the marginal likelihood is used. The expectationmaximization algorithm is proposed to iteratively maximize this likelihood function. Simulation results show that the resulting estimator offers statistical efficiency over a wider range of scenarios than previously published methods. Index Terms—Cramer–Rao bound (CRB), expectationmaximization (EM), maximumlikelihood (ML) estimation, signaltonoise ratio (SNR). I.
Disa: A robust scheduling algorithm for scalable crosspointbased switch fabrics
 IEEE Journal of Selected Areas in Communications
, 2003
"... Abstract—This paper presents and analyzes a highperformance, robust, and scalable scheduling algorithm for inputqueued switches called distributed sequential allocation (DISA). In contrast to pointerbased arbitration schemes, the proposed algorithm is based on a synchronized output reservation p ..."
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Cited by 9 (8 self)
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Abstract—This paper presents and analyzes a highperformance, robust, and scalable scheduling algorithm for inputqueued switches called distributed sequential allocation (DISA). In contrast to pointerbased arbitration schemes, the proposed algorithm is based on a synchronized output reservation process, whereby each input selects a designated output while taking into consideration both local transmission requests and the availability of global resources. The distinctiveness of the algorithm lies in its ability to offer high performance when multiple cells are transmitted within each switching interval. Relaxed switchingtime requirements allow for the incorporation of commercially available crosspoint switches. The result is a pragmatic and scalable solution for high portdensity switching platforms. The efficiency of the scheme and its robustness in the presence of admissible traffic, without the need for speedup, is established through analysis and computer simulations. Performance results are shown for various traffic scenarios including nonuniform destination distribution, correlated arrivals and multiple classes of service. Index Terms—Inputqueued switches, packet scheduling algorithms, qualityofservice (QoS), switch fabric, traffic modeling. I.
ON PHASE IMPORTANCE IN PARAMETER ESTIMATION IN SINGLECHANNEL SPEECH ENHANCEMENT
"... In this paper, we study the impact of exploiting the spectral phase information to further improve the speech quality of the singlechannel speech enhancement algorithms. In particular, we focus on the two required steps in a typical singlechannel speech enhancement system, namely: parameter estima ..."
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Cited by 7 (6 self)
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In this paper, we study the impact of exploiting the spectral phase information to further improve the speech quality of the singlechannel speech enhancement algorithms. In particular, we focus on the two required steps in a typical singlechannel speech enhancement system, namely: parameter estimation solved by a minimum mean square error (MMSE) estimator of the speech spectral amplitude, followed by signal reconstruction stage, where the observed noisy phase is often used. For the parameter estimation stage, in contrast to conventional Wiener filter, a new MMSE estimator is derived which takes into account the clean phase information as a prior information. In our experiments, we show that by including the phase information in the two steps, it is possible to improve the perceived signal quality of the enhanced signal significantly with respect to the methods that do not employ the phase information. Index Terms — Singlechannel speech enhancement, phase prior, Wiener filter. 1.
A new Calculation Procedure for Spatial Impulse Responses in Ultrasound
 J. ACOUST. SOC. AM
, 1999
"... A new procedure for the calculation of spatial impulse responses for linear sound fields is introduced. This calculation procedure uses the well known technique of calculating the spatial impulse response from the intersection of a circle emanating from the projected spherical wave with the bound ..."
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Cited by 7 (1 self)
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A new procedure for the calculation of spatial impulse responses for linear sound fields is introduced. This calculation procedure uses the well known technique of calculating the spatial impulse response from the intersection of a circle emanating from the projected spherical wave with the boundary of the emitting aperture. This general result holds for all aperture boundaries for a flat transducer surface, and this is used in the procedure to yield the response for all types of flat transducers. An arbitrary apodization function over the aperture can be incorporated through a simple onedimensional integration. The case of a soft baffle mounting of the aperture is also included. Specific solutions for transducer boundaries made from lines are given, so that any polygon transducer can be handled. Specific solutions for circles are also given. Finally, a solution for a general boundary is stated, and all these boundary elements can be combined to, e.g., handle annular arrays ...
Linearly Coupled Communication Games
, 2009
"... This paper discusses a special type of multiuser communication scenario, in which users’ utilities are linearly impacted by their competitors’ actions. First, we explicitly characterize the Nash equilibrium and Pareto boundary of the achievable utility region. Second, the price of anarchy incurred ..."
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Cited by 6 (2 self)
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This paper discusses a special type of multiuser communication scenario, in which users’ utilities are linearly impacted by their competitors’ actions. First, we explicitly characterize the Nash equilibrium and Pareto boundary of the achievable utility region. Second, the price of anarchy incurred by the noncollaborative Nash strategy is quantified. Third, to improve the performance in the noncooperative scenarios, we investigate the properties of an alternative solution concept named conjectural equilibrium, in which individual users compensate for their lack of information by forming internal beliefs about their competitors. The global convergence of the best response and Jacobi update dynamics that achieve various conjectural equilibria are analyzed. It is shown that the Pareto boundaries of the investigated linearly coupled games can be sustained as stable conjectural equilibria if the belief functions are properly initialized. The investigated models apply to a variety of realistic applications encountered in the multiple access design, including wireless random access and flow control.