Adaptation Method (adaptation + method)

Distribution by Scientific Domains


Selected Abstracts


A variationally consistent mesh adaptation method for triangular elements in explicit Lagrangian dynamics

INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING, Issue 9 2010
Sudeep K. Lahiri
Abstract In this paper a variational formulation for mesh adaptation procedures, involving local mesh changes for triangular meshes, is presented. Such local adaptive changes are very well suited for explicit methods as they do not involve significant computational expense. They also greatly simplify the projection of field variables from the old to the new meshes. Crucially, the variational nature of the formulation used to derive the equilibrium equations at steps where adaptation takes place ensures that conservation of linear and angular momentum is obtained (Int. J. Numer. Meth. Engng 2000; 49:1295,1325). Several examples in 2-D showing the application of the proposed adaptive algorithms are used to demonstrate the validity of the methodology proposed. Copyright 2009 John Wiley & Sons, Ltd. [source]


Adaptive transfer function-based control of nonlinear process.

INTERNATIONAL JOURNAL OF ADAPTIVE CONTROL AND SIGNAL PROCESSING, Issue 10 2007
Case study: Control of temperature in industrial methane tank
Abstract The state model-based transfer function models are applied for adaptation of linear controller and disturbance compensator in a feedback/feed-forward control system of nonlinear process. An advantage of the presented adaptation method is the avoidance of artificial disturbances or iterative identification procedures for on-line estimation of process dynamic parameters. The adaptation is based on linearization of the process model at each sampling time about the current state point, independent of the process being at steady-state or transient conditions. The linear time-varying dynamics model is updated on-line using measured values of process variables and reduced to the first-order plus time delay transfer function models in order to directly apply well-developed controller tuning rules. Computational aspects of the adaptation method are discussed and computation algorithms are presented. The adaptive feedback/feed-forward control system was applied for controlling temperature in industrial methane tank, dynamic parameters of which vary in a wide range due to variations of methane-tank process load and external conditions. The heat balance-based process state model is developed and validated using observation data of real plant. Computer simulation of the proposed control system performance under extreme operating conditions demonstrates fast adaptation of controller parameters, robust behaviour and significant improvement in the controllers' performance compared to that of fixed-gain controllers. Copyright 2007 John Wiley & Sons, Ltd. [source]


Color adaptation for anomalous trichromats

INTERNATIONAL JOURNAL OF IMAGING SYSTEMS AND TECHNOLOGY, Issue 1 2004
Yong Man Ro
Abstract In this article, we propose a content-based color adaptation method for color vision impairment, especially for anomalous trichromats, to improve color information accessibility. Color degradation caused by anomalous trichromacy is compensated in digital color content with a range of the visible spectrum corresponding to color deficiency characteristics. To verify the usefulness of the proposed method, we performed clinical experiments as well as computer simulations. The results of both the experiments and the simulations show that the proposed adaptation could convey better color information to anomalous trichromats. 2004 Wiley Periodicals, Inc. Int J Imaging Syst Technol 14, 16,20, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ima.20002 [source]