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.

An efficient isogeometric beam formulation for analysis of 2D non-prismatic beams

Abstract: This study presents an efficient beam formulation for static and vibration analysis of 2D non-prismatic beams with the kinematic assumptions of the Timoshenko beam theory. Beams having complex configurations can be straightforwardly constructed by using B-spline basis functions, which are used for descriptions of the beam axis and the sectional height. This feature enables analysis of free-form non-prismatic beams with strong curvatures to be performed conveniently and accurately, and is not virtually found in any existing formulations that are related to non-prismatic beams. The concept of isogeometric analysis is adopted by discretizing the kinematic unknowns, i.e., the translational displacements of the beam axis and the sectional rotation, using B-spline basis functions. A procedure for the recovery of stress components is also presented. The accuracy and performance of the developed approach are assessed through several numerical examples which cover several types of beam, e.g., sinusoidal beam, tapered beam and Tschirnhausen's beam representing free-form beams. Furthermore, convergence tests are also performed to demonstrate convergence properties of the proposed formulation.

Cluster analysis for primary feeder identification using metering data

Abstract: This paper presents a methodology to identify the connected feeder of high-usage customers in a primary distribution network. The proposed methodology considers voltage characteristics of radial distribution and actual measurements. Based on 15-minute intervals metering, cluster analysis is applied to categorize customer patterns on the basis of voltage correlation. Afterwards, support vector classification is also introduced for outlier assigning and cluster separation. The feasibility of this method is demonstrated on a practical distribution network of industrial estate area. The result indicates that all of the customers is correctly identified, and its correctness percentage is also better than the existent network representation. Additionally, wavelet reduction offers the same performance as the original time-domain feature but more efficient use of time.

Enhancement of Cr(VI) Ion Removal Using Nanochitosan Coated on Bituminous Activated Carbon.

Abstract: Bituminous activated carbon (AC) has been widely used as a sorbent for adsorption of non-polar species, but its performance for removal of ionic species such as heavy metals has not been as efficient. In this study, AC was modified with chitosan nanoparticles (CN) using facile methods of dip coating and wet impregnation. The CN-coated AC demonstrated an increase in Cr(VI) removal efficiency in both kinetics and adsorption capacity. The adsorption capacity of the CN-coated AC (mg/g) was more than twice that of the uncoated AC (36.36 mg/g), or pure chitosan (32.57 mg/g). The sizes of the synthesized CN (160-2,000 nm) can be controlled by varying the concentration of the chitosan/reagents used. The adsorption isotherms are better described using the Freundlich rather than the Langmuir model and are in agreement with the heterogeneity of the surfaces. Adsorption kinetics followed that of the pseudo-second-order kinetics, suggesting chemisorption as a rate limiting step.

A Fine-Grained and Lightweight Data Access Control Model for Mobile Cloud Computing

Abstract: With rapidly increasing adoption of cloud computing and the advancement of today mobile computing, it is inevitable that mobile devices are used to receive and send the data through the mobile cloud platform. This increases the convenience and flexibility of data access over the cloud computing since data users are able to access the shared data anytime, anywhere via mobile devices. However, using mobile devices in accessing shared data in a cloud where the sensitive data is encrypted is not practical because mobile devices have limited computing resources in dealing with heavy cryptographic operations. In this article, we propose a lightweight collaborative ciphertext policy attribute role-based encryption (LW-C-CP-ARBE) scheme to support a fine-grained and lightweight access control for mobile cloud environment. We apply CP-ABE approach as a core cryptographic access control and introduce a new proxy re-encryption (PRE) protocol to reduce data re-encryption and decryption cost for the mobile users. To this end, the overhead in running the cryptographic operation at the end-user device is small. In addition, we develop secure access policy sharing and re-encryption protocol to enable users having write privilege to update the data and request the proxy to perform data re-encryption. Finally, we present the evaluation and experiments to demonstrate the efficiency and practicality of our system.