Sirod Sirisup

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Low-dimensional flow dynamical systems may converge to erroneous states after long-time integration, even if they are initialized with the correct state. In this paper, we investigate the accuracy of such two-dimensional models constructed from Karhunen–Loeve expansions for flows past a circular cylinder. We first demonstrate that although the short-term(More)
Data recovery and reconstruction methods for unsteady flow fields with spatio-temporal missing data are studied based on proper orthogonal decomposition (POD) and on Kriging interpolation. It is found that for sufficient temporal resolution, POD-based methods outperform Kriging interpolation. However, for insufficient temporal resolution, large spatial(More)
The incorrect shape and location of initial contour in the level set image segmentation method could lead to unreliable results but the proper initial contour is hard to design in some images. This paper proposes a method that is more independent using four vector flows instead of using edge detector to insert new contour. The geodesic active contour (GAC)(More)
The global arrays toolkit is a library that allows programmers to write parallel programs that use large arrays distributed across processing nodes through the aggregate remote memory copy interface (ARMCI). In this study, we have further our investigation on the performance of a parallel application implemented with the global arrays toolkit on homogeneous(More)
The global arrays toolkit is a library that allows programmers to write parallel programs that use large arrays distributed across processing nodes. The toolkit provides advantage of one-sided communication operations through the aggregate remote memory copy interface (ARMCI). In this study, we investigate the performance of a parallel application(More)
The Global Arrays toolkit is a library that allows programmers to write parallel programs that use large arrays distributed across processing nodes through the Aggregate Remote Memory Copy Interface (ARMCI). OpenMP is an application programming interface that supports shared memory multiprocessing on many architectures and platforms. In the Symmetric-Multi(More)
This paper investigates a new approach for efficiently calculating nozzle thrust based on a reduced order model formed by the proper orthogonal decomposition (POD) technique. The investigation has been done on the nozzle of MK66 rocket motor as a prototype problem. Here, the focus is on the thrust response in or near the design condition. It was found that(More)
As technology advances, computing resources also gain benefits in many aspects: larger capacity, increased capability as well as rapidity. However, with heterogeneously distributed resources in Grid computing environment, the development an application to fully utilize the resources is a challenge. Especially, the computing resources themselves regularly(More)
We investigate a variational data assimilation technique for retrieval of surface currents in shallow seas. We use a physically based image model consisting of shallow-water equations, which include the effects and source terms obtained from the bathymetry. These terms are included because they can be important with respect to the characteristics of(More)