Browsing by Author "Chao, Chih-Hsuan"

Now showing 1 - 2 of 2

Effects of intelligent feedback on online learners? engagement and cognitive load: the case of research ethics education
(2019-11-26)
Sun, Jerry Chih-Yuan
;
Yu, Shih-Jou
;
Chao, Chih-Hsuan
;
教育研究所
;
Institute of Education
The current study developed an intelligent learning environment for online education of research ethics and investigated how encouragement and warning intelligent feedback influenced learners? engagement (behavioural, emotional, and cognitive) and cognitive load (mental load and mental effort). Participants included 191 graduate students in Taiwan who were randomly assigned into four groups: a non-feedback group, a warning feedback group, an encouragement feedback group, and an encouragement plus warning feedback group. The intelligent feedback was established on the basis of learning analytics from a database of prior learners? online learning of off- or on-task behaviours. The system detected students? sequential behavioural patterns and provided instant intelligent feedback. The results showed that encouragement plus warning feedback caused higher emotional and cognitive engagement, whereas warning feedback led to higher mental load. The study suggests that when designing intelligent learning environments, encouragement, and warning intelligent feedback should be used jointly to enhance the appeal of the learning journey and to boost emotional engagement, thereby increasing students? willingness to learn. It is important to avoid using only warning feedback to reduce interference in learning.
Electrocatalytic performance of Pt nanoparticles sputter-deposited on indium tin oxide toward methanol oxidation reaction: The particle size effect
(2017-09-15)
Ting, Chao-Cheng
;
Chao, Chih-Hsuan
;
Tsai, Cheng Yu
;
Cheng, I-Kai
;
Pan, Fu-Ming
We sputter-deposited Pt nanoparticles with an average size ranging from 2.0 nm to 8.5 nm on the indium tin oxide (ITO) glass substrate, and studied the effect of the size of Pt nanoparticles on electrocatalytic activity of the Pt/ITO electrode toward methanol oxidation reaction (MOR) in acidic solution. X-ray photoelectron spectroscopy (XPS) reveals an interfacial oxidized Pt layer present between Pt nanoparticles and the ITO substrate, which may modify the surface electronic structure of Pt nanoparticles and thus influences the electrocatalytic properties of the Pt catalyst toward MOR. According to electrochemical analyses, smaller Pt nanoparticles exhibit slower kinetics for CO electrooxidation and MOR. However, a smaller particle size enables better CO tolerance because the bifunctional mechanism is more effective on smaller Pt nanoparticles. The electrocatalytic activity decays rapidly for Pt nanoparticles with a size smaller than 3 nm and larger than 8 nm. The rapid activity decay is attributed to Pt dissolution for smaller nanoparticles and to CO poisoning for larger ones. Pt nanoparticles of 5-6 nm in size loaded on ITO demonstrate a greatly improved electrocatalytic activity and stability compared with those deposited on different substrates in our previous studies. (C) 2017 Elsevier B.V. All rights reserved.