2,748 research outputs found
Integrated fault estimation and accommodation design for discrete-time Takagi-Sugeno fuzzy systems with actuator faults
This paper addresses the problem of integrated robust
fault estimation (FE) and accommodation for discrete-time
Takagi–Sugeno (T–S) fuzzy systems. First, a multiconstrained
reduced-order FE observer (RFEO) is proposed to achieve FE for
discrete-time T–S fuzzy models with actuator faults. Based on the
RFEO, a new fault estimator is constructed. Then, using the information
of online FE, a new approach for fault accommodation
based on fuzzy-dynamic output feedback is designed to compensate
for the effect of faults by stabilizing the closed-loop systems. Moreover,
the RFEO and the dynamic output feedback fault-tolerant
controller are designed separately, such that their design parameters
can be calculated readily. Simulation results are presented to
illustrate our contributions
General Volume-Preserving Mechanical Systems
In this letter, we present the general form of equations that generate a
volume-preserving flow on a symplectic manifold (M, \omega). It is shown that
every volume-preserving flow has some 2-forms acting the role of the
Hamiltonian functions in the Hamiltonian mechanics and the ordinary Hamilton
equations are included as a special case with a 2-form \frac{1}{n-1} H \omega
where H is the corresponding Hamiltonian.Comment: Plain LaTeX, 13 pages, no figure
Brane worlds in gravity with auxiliary fields
Recently, Pani, Sotiriou, and Vernieri explored a new theory of gravity by
adding nondynamical fields, i.e., gravity with auxiliary fields [Phys. Rev. D
88, 121502(R) (2013)]. In this gravity theory, higher-order derivatives of
matter fields generically appear in the field equations. In this paper we
extend this theory to any dimensions and discuss the thick braneworld model in
five dimensions. Domain wall solutions are obtained numerically. The stability
of the brane system under the tensor perturbation is analyzed. We find that the
system is stable under the tensor perturbation and the gravity zero mode is
localized on the brane. Therefore, the four-dimensional Newtonian potential can
be realized on the brane.Comment: 7 pages, 4 figure
iTrace: An Implicit Trust Inference Method for Trust-aware Collaborative Filtering
The growth of Internet commerce has stimulated the use of collaborative
filtering (CF) algorithms as recommender systems. A collaborative filtering
(CF) algorithm recommends items of interest to the target user by leveraging
the votes given by other similar users. In a standard CF framework, it is
assumed that the credibility of every voting user is exactly the same with
respect to the target user. This assumption is not satisfied and thus may lead
to misleading recommendations in many practical applications. A natural
countermeasure is to design a trust-aware CF (TaCF) algorithm, which can take
account of the difference in the credibilities of the voting users when
performing CF. To this end, this paper presents a trust inference approach,
which can predict the implicit trust of the target user on every voting user
from a sparse explicit trust matrix. Then an improved CF algorithm termed
iTrace is proposed, which takes advantage of both the explicit and the
predicted implicit trust to provide recommendations with the CF framework. An
empirical evaluation on a public dataset demonstrates that the proposed
algorithm provides a significant improvement in recommendation quality in terms
of mean absolute error (MAE).Comment: 6 pages, 4 figures, 1 tabl
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