A new stability analysis technique for systems composed of a differential equation coupled with a continuous time difference equation is proposed. It is based on the explicit construction of Lyapunov functionals from ...
详细信息
ISBN:
(纸本)9781467357159
A new stability analysis technique for systems composed of a differential equation coupled with a continuous time difference equation is proposed. It is based on the explicit construction of Lyapunov functionals from the knowledge of Lyapunov functions for subsystems. Robustness results of iISS type are inferred from these functionals.
Cloud computing has emerged as a new paradigm where IT resources are offered by cloud providers in a flexible and elastic way. However, the use and development of cloud services has not been standardized, thereby deri...
详细信息
ISBN:
(纸本)9781450315661
Cloud computing has emerged as a new paradigm where IT resources are offered by cloud providers in a flexible and elastic way. However, the use and development of cloud services has not been standardized, thereby deriving in migratability and interoperability difficulties. Different standardization initiatives exist seeking to normalize this situation, however none has predominated and a generalized consensus has not been reached. Consequently, several alternatives have been proposed based on the use of intermediate layers or middlewares seeking to isolate developers from the variability of specific cloud vendor services. These approaches provide a valid solution at the risk of shifting the lock-in effect from vendors to middlewares. In this paper, we explore an alternative solution based on the use of software adaptation (SA) techniques. Different guidelines are presented as the basis of an approach that will favor cloud application interoperability and migratability thereby avoiding vendor lock-in.
This paper deals with the identification of multi–input multi–output errors–in–variables (EIV) models in the Frisch scheme context. The extension of the Frisch scheme to MIMO models introduces some problems not pr...
详细信息
This paper deals with the identification of multi–input multi–output errors–in–variables (EIV) models in the Frisch scheme context. The extension of the Frisch scheme to MIMO models introduces some problems not present in the SISO case. The approach proposed in this paper relies on the association of EIV models to directions in the noise space and on the statistical properties of the residual of the EIV model. In particular, a selection criterion based on the comparison of the theoretical statistical properties of the residual with those computed from the data is introduced. The performance of the proposed identification algorithm is evaluated by means of numerical simulations.
This paper deals with the identification of errors–in–variables models where the additive input and output noises are mutually correlated white processes. The proposed solution is based on the extension of the dynam...
详细信息
This paper deals with the identification of errors–in–variables models where the additive input and output noises are mutually correlated white processes. The proposed solution is based on the extension of the dynamic Frisch scheme introduced in (Beghelli et al., 1990). First, a geometric characterization of the whole set of admissible solutions in the noise space is described. Then, a criterion that allows to select the solution of the identification problem inside the locus is proposed. This criterion relies on the properties of a set of high–order Yule–Walker equations. The effectiveness of this identification approach is tested by means of Monte Carlo simulations.
This paper deals with the stabilization via Casimir generation and energy shaping of linear, lossless, distributed port-Hamiltonian systems. Once inputs and outputs of the distributed port-Hamiltonian system have been...
详细信息
This paper deals with the stabilization via Casimir generation and energy shaping of linear, lossless, distributed port-Hamiltonian systems. Once inputs and outputs of the distributed port-Hamiltonian system have been chosen to obtain a well-defined boundary control systems, conditions for the existence of Casimir functions in closed-loop and of the associated semigroup are given, together with a criterion to be used to check asymptotic stability. Casimir functions suggest how to select the controller Hamiltonian to introduce a minimum at the desired equilibrium, while stability is ensured if proper “pervasive” boundary damping is present. The methodology is illustrated with the help of a Timoshenko beam with full-actuation on one side.
Abstract Errors-in-Variables (EIV) models consider the presence of additive errors on the measures of all measurable attributes of a process. Traditional identification procedures for these processes rely on the prope...
详细信息
Abstract Errors-in-Variables (EIV) models consider the presence of additive errors on the measures of all measurable attributes of a process. Traditional identification procedures for these processes rely on the properties of the covariance matrix of the observations and on its decomposition into the sum of a matrix associated with the (unknown) noiseless sequences and of the observation noise covariance matrix. This paper makes reference, in a behavioural framework, to the observed noisy trajectories and performs a decomposition of these trajectories into a regular part, defininig the associated behaviour of the process, and a noise part. The Monte Carlo simulations that have been performed show that the proposed approach leads to accurate estimates of both the system parameters and the noise variances.
This paper gives a novel delay-dependent admissibility condition of discrete-time singular systems with time-varying delays. For convenience, the time-varying delay is assumed to be the sum of delay lower bound and th...
详细信息
This paper gives a novel delay-dependent admissibility condition of discrete-time singular systems with time-varying delays. For convenience, the time-varying delay is assumed to be the sum of delay lower bound and the integral multiples of a constant delay. Specially, if the constant delay is of unit length, the delay is an interval-like time-varying delay. The proposed admissibility condition is presented and expressed in terms of linear matrix inequality (LMI) by Lyapunov approach. Generally, the uncertainty of time-varying delay would lead to conservatism. In this paper, this critical issue is tackled by accurately estimating the time-varying delay. Consequently, the proposed admissibility condition is less conservative than the existing results, which is demonstrated by a numerical example.
Over the last few years, mobile applications demonstrating Augmented Reality (AR) - such as Layar, Junaio and Google Goggles - have been introduced to consumers. We conducted an online survey to explore the user exper...
详细信息
ISBN:
(纸本)9781450310154
Over the last few years, mobile applications demonstrating Augmented Reality (AR) - such as Layar, Junaio and Google Goggles - have been introduced to consumers. We conducted an online survey to explore the user experience (UX) of early stage mobile AR applications available in the market in spring 2011, covering both location-based AR browsers and image recognition AR applications for objectbased interaction. We identify various types of experiences such applications have evoked by qualitatively analyzing 84 users' narratives of their most satisfying and unsatisfying experiences. The results highlight, for example, experiences of awareness of surroundings, empowerment, positive surprise, amazement and fascination from the novelty value, as well as some examples of immersion and social connectivity. The analysis indicates that the applications have not yet reached their potential in evoking a multifaceted user experience that is characteristic especially to AR. This work helps in understanding the experiential design potential in mobile AR and points out UX issues to further focus on in design. Copyright 2012 ACM.
We propose an approach for dependence tree structure learning via copula. A nonparametric algorithm for copula estimation is presented. Then a Chow-Liu like method based on dependence measure via copula is proposed to...
详细信息
We propose an approach for dependence tree structure learning via copula. A nonparametric algorithm for copula estimation is presented. Then a Chow-Liu like method based on dependence measure via copula is proposed to estimate maximum spanning bivariate copula associated with bivariate dependence relations. The main advantage of the approach is that learning with empirical copula focuses on dependence relations among random variables, without the need to know the properties of individual variables as well as without the requirement to specify parametric family of entire underlying distribution for individual variables. Experiments on two real-application data sets show the effectiveness of the proposed method.
In many scientific fields, from biology to sociology, community detection in complex networks has become increasingly important. This paper, for the first time, introduces Cooperative Co-evolution framework for detect...
详细信息
暂无评论