Presentations -

Hierarchical Modeling for Diffusion Systems: Symmetrically-networked Systems with Rank One Interconnection

Daisuke Tsubakino, Shinji Hara

ICCAS-SICE 2009 

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Event date： 2009.8

Language：English   Presentation type：Oral presentation (general)  

Country：Japan  

In this paper, we propose a hierarchical modeling of the systems described by conservation laws. A conservation law on a hierarchically parted domain can be considered as a subsystem which interacts with neighbor elements through fluxes. Therefore, we regard the system as a networked system of each subsystem. The important idea is to weaken the interconnection in the sense of a rank. For detailed analysis of our method, we apply the proposed method to a diffusion equation. The hierarchical model is described by a non-circulant block Toeplitz matrix. Because the resulting system is symmetrically-networked system, we can show that the eigenvalues of the system consist of those of related uniform models. We also show that our method relaxes the stability condition of the fully discretized model. Finally we examine the performance of the hierarchical model by numerical simulations.

Effective Layout of Plasma Actuators for a Flow Separation Control on a Wing International conference

Daisuke Tsubakino, Yoshiteru Tanaka, Kozo Fujiii

45th AIAA Aerospace Sciences Meeting and Exhibit 

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Event date： 2007.1

Language：English   Presentation type：Oral presentation (general)  

Country：United States  

Numerical Analysis for Magnetic Control of Heat-transfer and Pressure in Hypersonic Shock Wave Interference Flows International conference

Daisuke Tsubakino, Yoshiteru Tanaka, Kozo Fujii

The Fourth International Conference on Computational Fluid Dynamics 

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Event date： 2006.7

Language：English   Presentation type：Oral presentation (general)  

Country：Belgium  

Weighted balanced realization and model reduction for nonlinear systems International conference

Daisuke Tsubakino, Kenji Fujimoto

17th International Symposium on Mathematical Theory of Networks and Systems 

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Event date： 2006.7

Language：English   Presentation type：Oral presentation (general)  

Country：Japan  

In this paper a weighted balanced realization and model reduction for nonlinear systems is proposed which is based on singular value analysis of nonlinear Hankel operators. In the proposed model reduction procedure, an important property, stability is preserved. A numerical ex- ample is also shown. This result is expected to be a basis for weighted model order reduction for nonlinear systems.

On computation of nonlinear balanced realization and model reduction International conference

Kenji Fujimoto, Daisuke Tsubakino

2006 American Control Conference 

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Event date： 2006.6

Language：English   Presentation type：Oral presentation (general)  

Country：United States  

In this paper a computational algorithm for nonlinear balanced realization and model reduction based on Taylor series expansion is proposed. This algorithm requires recursive computations with respect to the order of the Taylor series in which we need to solve linear equations with unknown parameters in each step. Furthermore, the proposed method is applied to a double pendulum system. Some numerical simulations demonstrate the effectiveness of the proposed algorithm.