Sirindhorn International Institute of Technology

About: Sirindhorn International Institute of Technology is a based out in . It is known for research contribution in the topics: Supply chain & Combustion. The organization has 1048 authors who have published 1678 publications receiving 30067 citations.

Parallel tabu search algorithm for constrained economic dispatch

Abstract: A parallel tabu search (PTS) algorithm for solving ramp rate constrained economic dispatch (CED) problems for generating units with non-monotonically and monotonically increasing incremental cost (IC) functions is proposed. To parallelise tabu search (TS) algorithms efficiently, the neighbourhood decomposition is used to balance the computing load, whereas competitive selection is used to update the best solution reached among subneighbourhoods. The proposed PTS is implemented on a 32-processor Beowulf cluster with an Ethernet switching network on a generating unit system size in the range 10-80 units over the entire dispatch periods. With different subneighbourhood sizes, the proposed PTS compromises the experimental speedup and solution quality for the best performance. PTS is potentially viable for the online implementation of CED because of the substantial generator fuel cost savings and high speedup upper bounds.

A finite element study of stress distributions in normal and osteoarthritic knee joints.

Abstract: Objective: To study the stress distributions in normal and osteoarthritic knee joints using the finite element method (FEM). Material and Method: Three normal and three varus knee joints are included in the study. Computed tomography (CT) images of the lower extremities are used to create 3D geometric models consisting of bones, articular cartilages, menisci, and knee ligaments. Each of the lower extremities includes the femur, tibia, fibula, and talus. Each 3D geometric model is adjusted to the normal standing configuration with the help of its corresponding 2D radiographic image. After that, 3D finite element (FE) models are created from the adjusted 3D geometric models. FEM is then used to obtain stress distributions on the articular cartilages. In the analysis, the displacements on the posterior calcaneal articular surface of the talus are fully fixed. A vertical concentrated force equal to the body weight is applied at the femoral head. Results: In the normal knee joints, the maximum normal stresses on the articular cartilages in the lateral compartments are always higher than those in the medial compartments. In the varus knee joints, the opposite results are observed. However, in each normal knee joint, the stress distribution on the whole articular cartilage is moderately uniform. On the contrary, in each varus knee joint, comparatively high magnitudes of the normal stress are found on a large area of the articular cartilage in the medial compartment. Conclusion: Varus knee joints have higher stresses in the medial compartments while normal knee joints have higher stresses in the lateral compartments. This pilot study shows that FE studies are comparable to cadaveric studies. FEM can be used as an alternative method for studying and examining knee joints of patients. Keywords: Osteoarthritic knees, Stress distributions, Finite element method