This paper investigates the problem of semiglobal L2 disturbance attenuation for a class of nonlinear systems. By [4], our purpose of designing controllers is just to attenuate all disturbances in a given bounded subs...
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This paper investigates the problem of semiglobal L2 disturbance attenuation for a class of nonlinear systems. By [4], our purpose of designing controllers is just to attenuate all disturbances in a given bounded subset of L2[0, ∞). We prove that for any such a given bounded subset there exist partial state feedbacks and dynamic output feedbacks respectively which attenuate each disturbance in the given bounded subset in the 1/2 gain sense and attain asymptotic stability without disturbance.
Given a set T of tasks, each of unit length and having an individual deadline d(t) ∈ Z+, a set of precedence constraints on T, and a positive integer k &le |T|, we can ask "Is there a one-processor sch.dule ...
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There exist many compartmental lines in Chinese newspapers, which make layout analysis very inconvenient. This paper proposes an approach based on compartmental lines, which extracts compartmental lines first, then se...
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ISBN:
(纸本)0780378652
There exist many compartmental lines in Chinese newspapers, which make layout analysis very inconvenient. This paper proposes an approach based on compartmental lines, which extracts compartmental lines first, then segments the whole page with these lines, finally analyzes the interior area further using rectangle extension model. This method makes efficient use of the coordinate of the compartmental lines and avoids setting so many parameters in the components merging procedure, so it is more flexible. This method can locate compartmental lines accurately. Experiment shows that it is a page layout analysis algorithm with more universality.
The confluence of new technologies and the increasing adoption of standards are pushing eLearning to the forefront of web-based initiatives. Agent technology is seen as a critical factor in knowledge acquisition in se...
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ISBN:
(纸本)0889863806
The confluence of new technologies and the increasing adoption of standards are pushing eLearning to the forefront of web-based initiatives. Agent technology is seen as a critical factor in knowledge acquisition in semantically rich environments, as exemplified by the Semantic Web. In addition the development and delivery of learning content is facilitated by the adoption of eLearning standards. In this paper we consider an eLearning framework where the learning process is mediated by software agents and supported by a knowledge base on learner profiles and skill maps. The roles of the agents are closely associated with the different stages of the learning process. The proposed approach is put into perspective through a brief discussion of some of the challenges that eLearning development is facing.
Let H be a fixed directed graph on h vertices, let G be a directed graph on n vertices and suppose that at least Εn2 edges have to be deleted from it to make it H-free. We show that in this case G contains at least f...
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ISBN:
(纸本)9781581136746
Let H be a fixed directed graph on h vertices, let G be a directed graph on n vertices and suppose that at least Εn2 edges have to be deleted from it to make it H-free. We show that in this case G contains at least f(Ε, H)nh copies of H. This is proved by establishing a directed version of Szemerédi's regularity lemma, and implies that for every H there is a one-sided error property tester whose query complexity is bounded by a function of Ε only for testing the property PH of being H-free. As is common with applications of the undirected regularity lemma, here too the function 1/f(Ε, H) is an extremely fast growing function in Ε. We therefore further prove the following precise characterization of all the digraphs H, for which f(Ε, H) has a polynomial dependency on Ε: a homomorphism φ: V(H) → V(K), from a digraph H to K, is a function that satisfies (u, v) ∈ E(H) ⇒ (φ(u), φ(v)) ∈ E(K). The core of a digraph H is the smallest subgraph K of H, for which there is a homomorphism from H to K. We show that for a connected H, f(Ε, H) has a polynomial dependency on 1/Ε, if and only if the core of H is either an oriented tree or a directed cycle of length 2. This implies that there is a one sided error property tester for testing H-freeness, whose query complexity is polynomial in 1/Ε if and only if H is of the above two types. We further show that the same characterization applies for two-sided error property testers as well. A special case of this result settles an open problem raised by the first author in [1]. It turns out that if PH has a polynomial query complexity, then there is a two-sided Ε-tester for PH that samples only O(1/Ε) vertices, whereas any one-sided tester for PH makes at least (1/Ε)Ω(d) queries, where d is the average degree of H. We show that the complexity of deciding if for a given directed graph H, PH has a polynomial query complexity, is NP-complete, marking an interesting distinction from the case of undirected graphs. For some special cases of di
Ladner (J. Assoc. Comput. Mach. 22 (1975) 155) showed that there are no minimal recursive sets under polynomial-time reductions. Given any recursive set A, Ladner constructs a set B such that B strictly reduces to A b...
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An equistable chordal graphs were discussed. It was shown that a chordal graph was equistable if and only if every two adjacent non-simplicial vertices have a common simplicial neighbor. The threshold graphs were also...
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An equistable chordal graphs were discussed. It was shown that a chordal graph was equistable if and only if every two adjacent non-simplicial vertices have a common simplicial neighbor. The threshold graphs were also discussed.
Human perception is a complex nonlinear dynamics. On the one hand it is periodic dynamics and on the other hand it is chaotic. Thus, we wish to propose a hybrid - the spatial chaotic dynamics for the associative recal...
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Human perception is a complex nonlinear dynamics. On the one hand it is periodic dynamics and on the other hand it is chaotic. Thus, we wish to propose a hybrid - the spatial chaotic dynamics for the associative recall to retrieve patterns, similar to Walter Freeman's discovery, and the fixed point dynamics for memory storage, similar to Hopfield and Grossberg's discoveries. In this model, each neuron in the network could be a chaotic map, whose phase space is divided into two states: one is periodic dynamic state with period-V, which is used to represent a V-value retrieved pattern;another is chaotic dynamic state. Firstly, patterns are stored in the memory by fixed point learning algorithm. In the retrieving process, all neurons are initially set in the chaotic region. Due to the ergodicity property of chaos, each neuron will approximate the periodic points covered by the chaotic attractor at same instants. When this occurs, the control is activated to drive the dynamic of each neuron to their corresponding stable periodic point. Computer simulations confirm the theoretical prediction.
In this paper we propose a case base reduction technique which uses a metric defined on the solution space. The technique utilises the Generalised Shepard Nearest Neighbour (GSNN) algorithm to estimate nominal or real...
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ISBN:
(数字)9783540450061
ISBN:
(纸本)9783540404330
In this paper we propose a case base reduction technique which uses a metric defined on the solution space. The technique utilises the Generalised Shepard Nearest Neighbour (GSNN) algorithm to estimate nominal or real valued solutions in case bases with solution space metrics. An overview of GSNN and a generalised reduction technique, which subsumes some existing decremental methods, such as the Shrink algorithm, are presented. The reduction technique is given for case bases in terms of a measure of the importance of each case to the predictive power of the case base. A trial test is performed on two case bases of different kinds, with several metrics proposed in the solution space. The tests show that GSNN can out-perform standard nearest neighbour methods on this set. Further test results show that a case-removal order proposed based on a GSNN error function can produce a sparse case base with good predictive power.
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