Reliable H∞ output control of nonlinear systems with dynamic event-triggered scheme

This paper is concerned with the reliable event-triggered H_∞ output control of nonlinear systems with actuator faults. A dynamic triggering scheme depending on system outputs is implemented to reduce the amount of communication transmissions, which is different from existing constant triggering thresholds. The parameters of actuator faults are estimated via observer state. To compensate for the fault effects on systems, the reliable controller parameters are adjusted along with the obtained estimations. By using some technical lemmas, new sufficient conditions for the closed-loop system to be asymptotically stable with prescribed H_∞ performance are formed in linear matrix inequalities. Lastly, simulations are implemented to demonstrate the validity of the proposed method.     

Modelling pre-service teachers’ perceived usefulness of an ICT-based student-centred learning (SCL) curriculum: a Singapore study

The purpose of this study is to examine the factors that influence pre-service teachers’ perceived usefulness of an Information and Communication Technology (ICT) course that was conducted using the student-centred learning (SCL) approach. In this study, perceived usefulness was used as the dependent variable and perceived competence, course delivery, facilitating conditions and learning environment as independent variables. The results of this study showed that perceived competence and course delivery have direct effects on pre-service teachers’ perceived usefulness of the course, while learning environment and facilitating conditions affect perceived usefulness indirectly. Overall, the results support the hypothesis that the four selected variables in this study affect perceived usefulness and that the resulting model is an adequate fit to the observed relationships among the factors that influenced pre-service teachers’ perceived usefulness of an ICT course.     

Examining practicing teachers’ perceptions of technological pedagogical content knowledge (TPACK) pathways: a structural equation modeling approach

The seven constructs of the technological pedagogical content knowledge (TPACK) framework has been widely adopted as a theoretical basis for understanding the scope of teachers’ information and communication technology (ICT) expertise. Despite this, very little is understood about the inter-relationships between these constructs, especially how these relationships are related to teachers’ TPACK. As a result, the theory–practice nexus of this framework remains weak. In this study, a structural equation model based on Mishra and Koehler’s TPACK framework was developed to describe the TPACK perceptions of 455 practicing teachers in Singapore. The study shows that teachers, perceived TPACK to be formulated from the direct effects of technological knowledge and pedagogical knowledge. They also perceived these knowledge sources to contribute to the development of technological pedagogical knowledge and technological content knowledge, which also contributed to their TPACK. In these teachers’ conceptions of TPACK, however, the effects of content knowledge and pedagogical content knowledge were not evident. The implications of these relationships to the design of teacher professional development in ICT are discussed.     

Identifying Science Teachers’ Perceptions of Technological Pedagogical and Content Knowledge (TPACK)

The application of information and communication technology in instruction is highly emphasized in the contemporary education of science teachers. This paper hence aims to explore science teachers’ perceptions of technological pedagogical content knowledge (TPACK) addressing teachers’ perceptions of the affordances of technology application in instruction. A total of 222 pre- and in-service science teachers in Singapore were surveyed. Structural equation models analysis was utilized to examine the model of TPACK involving the seven factors of technological knowledge (TK), pedagogical knowledge (PK), content knowledge (CK), technological content knowledge (TCK), technological pedagogical knowledge (TPK), pedagogical content knowledge (PCK), as well as synthesized knowledge of technology, pedagogy, and content (TPC). The results confirm the seven-factor model and indicate that the science teachers’ perceived TPC significantly and positively correlated with all the other TPACK factors. This paper further reveals the relationships between the science teachers’ perceptions of TPACK and their demographic characteristics such as teaching experience, gender, and age. The findings indicate that female science teachers perceive higher self-confidence in pedagogical knowledge but lower self-confidence in technological knowledge than males. Further, female in-service science teachers’ perceptions of TK, TPK, TCK, and TPC significantly and negatively correlate with their age.     

Widening Our Global View: The Development of Career Counseling Services for International Students

The increased number of international students in United States universities and colleges have created the need for the development of services that appropriately reflect their needs and characteristics. The Career Center at the University of Missouri, Columbia reacted to this phenomenon by developing career services exclusively for international students. Career services are provided as individual services and online services, and consist of information on graduate schools and entrance examination practices, information on available employment opportunities and work permit policies, career assessments, and information about specific skills for obtaining a job in the United States. Several marketing strategies were used to ensure international students' use of services. Important points in developing career services for international students are presented.     

Urinary N-acetyl beta glucosaminidase and gamma glutamyl transferase as early markers of diabetic nephropathy.

Albumin and enzymes-N-acetyl-beta-glucosaminidase (NAG) and gamma glutamyl transferase (GGT) were estimated in the morning random urine samples of 196 albustix negative diabetic patients to evaluate the clinical utility of these urinary enzymes as early markers of diabetic nephropathy. Albumin was estimated by immunoturbidimetric method and enzymes by linetic essay within six hours of voiding of urine. The urinary albumin and urinary enzyme concentration was calculated in terms of ratio with respect to urinary creatinine. Correlation coefficient (r) bewween urinary albumin and urinary enzymes in normoalbuminuric, microalbuminuric and overall diabetic cases was 0.23, 0.32 and 0.40 respectively for NAG, and 0.08, 0.06 and 0.18 respectively for GGT. NAG excretion was found increased in 34%, 63.7% and 49.5% of normoalbuminuric, microalbuminuric and overall diabetic cases respectively while GGT in 6.4%, 24.5% and 15.8%. The correlation coefficient between urinary albumin and NAG in normoalbuminuric, microalbuminuric, and overall diabetic patients with increased NAG excretion was found only 0.31, 0.27 and 0.35 respectively. No correlation was found between duration of diabetes and enzyme excretion. The study suggests that urinary NAG or GGT or both together do not have any clinical significance as an early marker of diabetic nephropathy.     

Teachers' pedagogical beliefs and their planning and conduct of computer-mediated classroom lessons

In this study, we observed and interviewed six teachers from two Singapore primary school classrooms. The schools were reportedly achieving high levels of computer integration as reflected in a nationwide questionnaire survey. Out of the 18 lessons that we observed, 14 lessons have incorporated some elements of constructivist teaching. However, closer examination revealed that the underlying orientation of the lessons was inclined towards information acquisition and regurgitation. Five out of the six teachers we interviewed were reportedly inclined towards constructivist notion of teaching. The teachers accounted for the inconsistency between their espoused beliefs and the teacher-centric teaching practice as due to contextual constraints. The teachers expressed that the need to complete the syllabi according to stipulated schedules so as to get the students ready for examination was the main barriers that prevented them from engaging in more constructivist teaching. This case study therefore highlights that although it is necessary for teachers to hold pedagogical beliefs that are compatible with the constructivist notion of teaching and learning, this is an insufficient condition to shift traditional teaching practice. Changes in assessment systems and substantial professional development are further conditions that have to be addressed.     

The mediating effects of needs satisfaction on the relationships between prior knowledge and self-regulated learning through artificial intelligence chatbot

The anthropomorphic characteristics of artificial intelligence (AI) can provide a positive environment for self-regulated learning (SRL). The factors affecting adolescents' SRL through AI technologies remain unclear. Limited AI and disciplinary knowledge may affect the students' motivations, as explained by self-determination theory (SDT). In this study, we examine the mediating effects of needs satisfaction in SDT on the relationship between students' previous technical (AI) and disciplinary (English) knowledge and SRL, using an AI conversational chatbot. Data were collected from 323 9th Grade students through a questionnaire and a test. The students completed an AI basic unit and then learned English with a conversational chatbot for 5 days. Confidence intervals were calculated to investigate the mediating effects. We found that students' previous knowledge of English but not their AI knowledge directly affected their SRL with the chatbot, and that satisfying the need for autonomy and competence mediated the relationships between both knowledge (AI and English) and SRL, but relatedness did not. The self-directed nature of SRL requires heavy cognitive learning and satisfying the need for autonomy and competence may more effectively engage young children in this type of learning. The findings also revealed that current chatbot technologies may not benefit students with relatively lower levels of English proficiency. We suggest that teachers can use conversational chatbots for knowledge consolidation purposes, but not in SRL explorations.

Practitioner notes

What is already known about this topic

• Artificial intelligence (AI) technologies can potentially support students' self-regulated learning (SRL) of disciplinary knowledge through chatbots.
• Needs satisfaction in Self-determination theory (SDT) can explain the directive process required for SRL.
• Technical and disciplinary knowledge would affect SRL with technologies.

What this paper adds

• This study examines the mediating effects of needs satisfaction in SDT on the relationship between students' previous AI (technical) and English (disciplinary) knowledge and SRL, using an AI conversational chatbot.
• Students' previous knowledge of English but not their AI knowledge directly affected their SRL with the chatbot.
• Autonomy and competence were mediators, but relatedness was not.

Implications for practice and/or policy

• Teachers should use chatbots for knowledge consolidation rather than exploration.
• Teachers should support students' competence and autonomy, as these were found to be the factors that directly predicted SRL.
• School leaders and teacher educators should include the mediating effects of needs satisfaction in professional development programmes for digital education.