Intelligent tracking control of a DC motor driver using self-organizing TSK type fuzzy neural networks

[[abstract]]In this paper, a self-organizing Takagi–Sugeno–Kang (TSK) type fuzzy neural network (STFNN) is proposed. The self-organizing approach demonstrates the property of automatically generating and pruning the fuzzy rules of STFNN without the preliminary knowledge. The learning algorithms not only extract the fuzzy rule of STFNN but also adjust the parameters of STFNN. Then, an adaptive self-organizing TSK-type fuzzy network controller (ASTFNC) system which is composed of a neural controller and a robust compensator is proposed. The neural controller uses an STFNN to approximate an ideal controller, and the robust compensator is designed to eliminate the approximation error in the Lyapunov stability sense without occurring chattering phenomena. Moreover, a proportional-integral (PI) type parameter tuning mechanism is derived to speed up the convergence rates of the tracking error. Finally, the proposed ASTFNC system is applied to a DC motor driver on a field-programmable gate array chip for low-cost and high-performance industrial applications. The experimental results verify the system stabilization and favorable tracking performance, and no chattering phenomena can be achieved by the proposed ASTFNC scheme.[[notice]]補正完畢[[incitationindex]]SCI[[booktype]]紙本[[booktype]]電子

Learning through 'prosuming': Insights from media literacy programmes in Asia

10.1177/097172180801300205Science, Technology and Society132259-27

Why is mathematics valuable?: a comparison of Turkish and German mathematics teachers

This study was based on the data obtained from "Values in Mathematics Teaching in Turkey and Germany [VMTG]" project which lasted two years. The VMTG project compares German and Turkish mathematics teachers' and their students' values. The purpose of the study is to investigate Turkish and German mathematics teachers' views on why math is valuable, and explore the mathematical values behind their views. The study was undertaken with 9 Turkish and 13 German mathematics teachers. Even though several data collection instruments (i.e. observation sheets, Likert type (multiple choice) questionnaire, and questionnaire consisting of open-ended questions) were used in the project, only the data gathered from semi-structured interviews were the basis for the analysis of the study. Collected data were subjected to constant comparative method. Results revealed that two different major categories emerged: (1) isolated thinking and (2) connected thinking. Discussion, recommendation and further educational implications were provided at the end based on the data

In-Situ Thermographic Inspection for Laser Powder Bed Fusion

Laser powder bed fusion is strongly influenced by the quality of the powder layer including the powder properties as well as the layer thickness. In particular, thermal stresses can produce sufficient part deformation to the point that a part interferes with the wiper. This paper investigates the use of long-wave infrared thermography to monitor the surface temperature of the build. When cold powder is spread by the wiper, heat diffuses from the underlying part through the powder. The surface temperature history is a strong function of the thermal transport properties of the powder as well as the thickness. This correlation is explored and measured experimentally. It is then used to estimate the powder layer thickness above overhanging parts. This approach is shown to capture the part distortion and predicts wiper state prior to catastrophic interaction with the part.Mechanical Engineerin