In this paper, the problem of robust stabilization for a class of uncertain switched linear systems with unknown-but-bounded uncertainty is studied. By using the condition of completeness, a sufficient condition of ro...
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In this paper, the problem of robust stabilization for a class of uncertain switched linear systems with unknown-but-bounded uncertainty is studied. By using the condition of completeness, a sufficient condition of robust stabilization for switched systems is obtained under the assumption that each subsystem can't be stabilized. Based on LMI (linear matrix inequality) method, robust state feedback controllers and a switching law are designed to make the closed-loop systems be asymptotically stable on the equilibrium point. The simulation result shows the validity of the designed controllers and the switching law.
Reliable control of pole placement was presented for linear systems with continuous gain actuator faults. When faults occur, the closed-loop poles of standard system are out of a specified sector region. However, the ...
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Reliable control of pole placement was presented for linear systems with continuous gain actuator faults. When faults occur, the closed-loop poles of standard system are out of a specified sector region. However, the closed-loop poles of reliable system are still in a specified sector region, not only when all actuators are operational, but also when some actuator faults occur. Based on LMIs, a sufficient condition for the existence of reliable control is given. The helicopter CH-47 simulation results show the effectiveness of the design method. Furthermore, the standard system and the reliable system were compared to show the necessity of reliable control.
Attribute reduction is one of the main issues in classification knowledge acquisition in information systems. Many types of attribute reduction have been proposed in the area of rough sets. In this paper the concept o...
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ISBN:
(纸本)0780384032
Attribute reduction is one of the main issues in classification knowledge acquisition in information systems. Many types of attribute reduction have been proposed in the area of rough sets. In this paper the concept of an R-information system is introduced and a general version of attribute reduction in R-information systems is proposed, then the judgment theorems concerning the reduction are presented.
This paper is concerned with the reliable H∞ control design problem for linear systems with actuator faults. A more practical model of actuator faults is considered. An LMI approach of designing reliable controller i...
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This paper is concerned with the reliable H∞ control design problem for linear systems with actuator faults. A more practical model of actuator faults is considered. An LMI approach of designing reliable controller is presented for the case of actuator faults that can be modeled by a scaling factor. The resulting control systems are reliable in that they provide guaranteed asymptotic stability and H∞ performance when some control component (actuator) faults occur. A numerical example is also given to illustrate the design procedure and their effectiveness. Furthermore, the optimal H∞ standard controller and the optimal H∞reliable controller were compared to show the necessity of reliable control.
We prove that all transition rates with respect to reversible cyclic Markov chains with continuous time are uniquely determined by the distributions of their hitting time and sojourn time at two neighboring states. As...
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We prove that all transition rates with respect to reversible cyclic Markov chains with continuous time are uniquely determined by the distributions of their hitting time and sojourn time at two neighboring states. As a result, we can estimate all the statistical characteristics based upon the statistics of the hitting time and sojourn time. As an example, we give its applications to modelling of ion channels in biology.
A methodology is shown for predicting the time-dependent reliability of ceramic components against catastrophic rupture when subjected to transient thermomechanical loads (including cyclic loads). The methodology take...
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A methodology is shown for predicting the time-dependent reliability of ceramic components against catastrophic rupture when subjected to transient thermomechanical loads (including cyclic loads). The methodology takes into account the changes in material response that can occur with temperature or time (i.e., changing fatigue and Weibull parameters with temperature or time). This capability has been added to the NASA CARES/Life (Ceramic Analysis and Reliability Evaluation of Structures/Life) code. The code has been modified to have the ability to interface with commercially available finite element analysis (FEA) codes executed for transient load histories. Examples are provided to demonstrate the features of the methodology as implemented in the CARES/Life program.
The University of Colorado teamed with Arapahoe and Red Rocks Community coll.ges to developed the foundations of Engineering, science and Technology (FEST) program. The program intends to increase capabilities for onl...
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The University of Colorado teamed with Arapahoe and Red Rocks Community coll.ges to developed the foundations of Engineering, science and Technology (FEST) program. The program intends to increase capabilities for online and blended delivery of the core math.matics, engineering science and information technology courses to enter 4-year engineering degree program. Implementing e-learning technology into FEST will bring real-world problems into classrooms and increase learning effectiveness through online tutors and teachers with blended courses. Integrating the present ad hoc FEST system into one content management system is expected to be the next stage to help FEST project achieve its objectives more efficiently and effectively.
Fuzzy variable is a function from a possibility space to the real line. In this paper, two classes of fuzzy programming problems with fuzzy variable coefficients are presented. The first one is called primal fuzzy pro...
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Fuzzy variable is a function from a possibility space to the real line. In this paper, two classes of fuzzy programming problems with fuzzy variable coefficients are presented. The first one is called primal fuzzy programming problem whose objective is a chance function defined by possibility measure, while the second one is called inverse fuzzy programming problem whose objective is a critical value function. Generally, the difficulties of solving the two fuzzy programming problems are different. Thus, to solve the problems effectively, we prove two main results which show solving one of the problems is equivalent to solving its counterpart.
Fuzzy random variable has been defined in several ways in literature. This paper presents a new definition of fuzzy random variable, and gives a novel definition of scalar expected value operator for fuzzy random vari...
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Fuzzy random variable has been defined in several ways in literature. This paper presents a new definition of fuzzy random variable, and gives a novel definition of scalar expected value operator for fuzzy random variables. Some properties concerning the measurability of fuzzy random variable are also discussed. In addition, the concept of independent and identically distributed fuzzy random variables is introduced. Finally, a type of law of large numbers is proved.
In this paper, two new concepts of lower approximation reduction and upper approximation reduction are introduced. Lower approximation reduction is the smallest attribute subset that preserves the lower approximations...
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ISBN:
(纸本)3540140409
In this paper, two new concepts of lower approximation reduction and upper approximation reduction are introduced. Lower approximation reduction is the smallest attribute subset that preserves the lower approximations of all decision classes, and upper approximation reduction is the smallest attribute subset that preserves the upper approximations of all decision classes. For an inconsistent DT, an upper approximation consistent set must be a lower approximation consistent set, but the converse is not true. For a consistent DT, they are equivalent. After giving their equivalence definitions, we examine the judgement theorem and discernibility matrices associated with the two reducts, from which we can obtain approaches to knowledge reduction in inconsistent decision tables.
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