共查询到20条相似文献，搜索用时 15 毫秒
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Let X=x1,x2,…,xn be a sequence of non-decreasing integer values. Storing a compressed representation of X that supports access and search is a problem that occurs in many domains. The most common solution to this problem uses a linear list and encodes the differences between consecutive values with encodings that favor small numbers. This solution includes additional information (i.e. samples) to support efficient searching on the encoded values. We introduce a completely different alternative that achieves compression by encoding the differences in a search tree. Our proposal has many applications, such as the representation of posting lists, geographic data, sparse bitmaps, and compressed suffix arrays, to name just a few. The structure is practical and we provide an experimental evaluation to show that it is competitive with the existing techniques. 相似文献
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This paper presents a study on the problem of designing non-fragile H∞ filters with sparse structure for linear discrete-time systems. The filters to be designed with sparse structure are assumed to be with additive gain variations, which are resulted from filter implementations. Firstly, a class of sparse structures is specified from a given fully parameterized H∞ filter. Then, an LMI-based procedure for designing non-fragile H∞ filters with the sparse structure is provided. The resulting design guarantees the augmented system asymptotically stable and the H∞ attenuation level less than a prescribed level. A numerical example is given to illustrate the proposed method. 相似文献
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This paper is concerned with the ?2−?∞ filtering problem for discrete-time Markovian jump repeated scalar nonlinear systems. Our attention is focused on the design of full- and reduced-order filters that guarantee the filtering error system to be stochastically stable with a prescribed weighted ?2−?∞ performance. By employing both the mode dependent Lyapunov function approach and the positive definite diagonally dominant Lyapunov function technique, a sufficient condition is firstly established, which guarantees the Markovian jump repeated scalar nonlinear system to be stochastically stable with an induced ?2−?∞ disturbance attenuation performance. The corresponding full-order filter design is cast into a convex optimization problem, which can be efficiently handled by using standard numerical algorithms. Finally, a numerical example is presented to show the effectiveness of the proposed methods. 相似文献
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We consider robust optimization equilibrium for the bimatrix game based on robust optimization method. In this paper, each player may neither exactly estimate his opponent's strategies nor evaluate his own cost matrix accurately while may estimate a bounded uncertain set. We obtain that the robust optimization equilibrium problem can be formulated as a mixed complementarity problem (MCP) under l1∩l∞-norm. Some numerical examples are presented to illustrate the behavior of robust optimization equilibrium. 相似文献
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In this paper, a new type of switched parallel distributed compensation (PDC) controller is presented, in which a novel switching scheme, namely, membership function ranking (MFR) scheme is proposed. The MFR scheme can be viewed as an improvement and extension of previous results named largest membership function (LMF) scheme concerned with piece-wise quadratic Lyapunov function (PQLF) approach, since it provides a denser subdivision of normalized membership function space and therefore essentially yields less conservative results. Moreover, it shows that MFR scheme covers LMF scheme as a particular case. Based on MFR scheme, a family of ?∞ controllers and a switching scheme is designed to ensure the closed-loop system asymptotically stable and has a required ?∞ performance. A design example is presented to illustrate the advantages of MFR scheme. 相似文献
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Mathematical models are an approximate of physical systems and design procedures are only complete when modeling errors have been quantified. Uncertainties are incorporated in design procedure to compensate such discrepancies and to add robustness. This paper investigates the design problem of parameter-dependent switched observers for polytopic uncertain switched systems. State-space model is considered subject to time-varying uncertainties, and designated observer gains ensuring stability of overall system are also parameter-dependent. Synthesis procedure is demonstrated by employing ?∞ performance criteria which has become a standard for robust system design against external disturbances. This investigation is carried out in the framework of finite-time stability (FTS) and finite-time boundedness (FTB) which is the focus of researchers recently because of its apparent practical significance, especially after the emergent utilization of linear matrix inequalities. 相似文献
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This paper is concerned with finite-time H∞ control problem for a class of switched linear systems by using a mode-dependent average dwell time (MDADT) method. The switching signal used in this paper is more general than the average dwell time (ADT), in which each mode has its own ADT. By combining the MDADT and Multiple Lyapunov Functions (MLFs) technologies, some sufficient conditions, which can guarantee that the corresponding closed-loop system is finite-time bounded with a prescribed H∞ performance, are derived for the switched systems. Moreover, a set of mode-dependent dynamic state feedback controllers are designed. Finally, two examples are given to verify the validity of the proposed approaches. 相似文献
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The sampled-data H∞ filtering for a continuous-time Takagi–Sugeno fuzzy system with an interval time-varying state delay is investigated, where the measurement outputs from the plant to the filter are assumed to be sampled at discrete instants with a variable period. Firstly, by means of a newly proposed inequality bounding technique and a new Lyapunov–Krasovskii functional, the fuzzy sampled-data H∞ filtering performance analysis is carried out such that the resultant filter error system is asymptotically stable with a prescribed H∞ attenuation performance index. Secondly, sufficient conditions on the existence of fuzzy sampled-data H∞ filters are derived in the simultaneous presence of the time-varying state delay and the variable sampling period. The proposed bounding inequality lies in its more tightness and alleviates the enlargement of some inverse “coefficients” resulting from the utilization of the well-known Jensen integral inequality . Compared with some existing Lyapunov–Krasovskii functionals, more information about the relationship among the current state and its delayed state is considered. The upper bound of the derivative of the time-varying state delay is not required to be less than one. Different from some existing results in the literature, by applying the proposed results, each different value of such an upper bound (greater than one) leads to a different H∞ disturbance attenuation level. Finally, a numerical example and a modified continuous stirred tank reactor system are given to show the effectiveness of the proposed results. 相似文献
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This paper is concerned with the H∞ output-feedback control problem for a class of discrete-time systems with randomly occurring nonlinearities (RONs) as well as randomly occurring distributed delays (RODDs). Both RONs and RODDs are governed by random variables obeying the Bernoulli distributions. The measurement output is subject to the sensor saturations described by sector-nonlinearities as well as the channel fadings caused typically in wireless communication. The aim of the addressed problem is to design a full-order dynamic output-feedback controller such that, in the simultaneous presence of RONs, RODDs, sensor saturations and channel fadings, the closed-loop system is exponentially mean-square stable and satisfies the prescribed H∞ performance constraint. By using a combination of the stochastic analysis and Lyapunov functional approaches, sufficient conditions are derived for the existence of the desired controllers and then the characterization of such controllers is given via the semi-definite programme method. Finally, the numerical simulation result is exploited to illustrate the usefulness and effectiveness of the proposed design technique. 相似文献
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This paper investigates the robust H∞ dynamic output feedback control problem for networked control systems (NCSs) with quantized measurements. The measurement losses of the communicated information are considered in an unreliable communication channel. The robust H∞ dynamic output feedback controllers are designed to handle the measurement losses and mitigate the quantization effects such that the resultant closed-loop NCS is mean-square stochastically stable with a prescribed H∞ disturbance attenuation performance. The controller existence conditions can be derived in terms of linear matrix inequalities (LMIs). Finally, an example is provided to illustrate the effectiveness of the proposed approach. 相似文献
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This paper investigates the problem of H∞ filtering for Markovian jump linear systems with time-varying delay. The aim of this problem is to design an H∞ filter that ensures stochastic stability of the filtering error system and a prescribed L2-induced gain from the noise signals to the estimation error, for all admissible uncertainties. For solving the problem, we transform the system under consideration into an interconnection system. Based on the system transformation and the stochastic scaled small gain theorem, stochastic stability of the original system is examined via the stochastic stability version of the bounded realness of the transformed forward system. The merit of the proposed approach lies in its reduced conservatism, which is made possible by a precise approximation of the time-varying delay and the stochastic scaled small gain theorem. The proposed H∞ filtering condition is demonstrated to be less conservative than most existing results. Moreover, the H∞ filter design condition is further presented via convex optimizations, whose effectiveness are also illustrated via numerical examples. 相似文献
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This paper studies the problem of H∞ filtering problem for a class of nonlinear time-varying delay systems with unideal communication links. Two defectives are concerned including measurement quantization and packet dropouts. The quantized measurements are transmitted to the filter via network, where the phenomena of packet loss are taken into account. By using Lyapunov–Krasovskii functional, a less conservative delay-dependent stability condition for the closed-loop NCSs is derived. The H∞ fuzzy controller, which is designed in terms of linear matrix inequalities (LMIs), is developed for the asymptotic stabilization of the closed-loop NCSs. Numerical examples are given to illustrate the effectiveness of the proposed method. 相似文献
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This paper focuses on the problem of H∞ filter design for continuous-time Takagi and Sugeno (T–S) fuzzy systems with time-varying delays. The partitioning time delay technique is used to construct the Lyapunov–Krasovskii functional, furthermore, a novel delay-dependent H∞ filter design approach is proposed based on the matrix decoupling approach, and the filter parameters can be obtained by solving a set of linear matrix inequalities (LMIs). The numerical examples show that the proposed method is of less conservativeness than the existing methods. 相似文献
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This paper studies the problem of robust H∞ controller design for a class of uncertain Markov jump systems with time-varying transition probabilities, which follows nonhomogeneous jump processes. The time varying transition probability matrix is described as a polytope set. By Lyapunov function approach, under the designed controller, a sufficient condition is presented to ensure that the resulting closed-loop system is stochastically stable and that a prescribed H∞ performance index is satisfied. Finally, an application of a DC motor device is addressed to demonstrate the effectiveness of developed techniques. 相似文献