Hopf bifurcation and synchronization of a five-dimensional self-exciting homopolar disc dynamo using a new fuzzy disturbance-observer-based terminal sliding mode control

Having found hidden hyperchaos in a 5D self-exciting homopolar disc dynamo, we study the existence of a Hopf bifurcation, which leads to unstable limit cycles bifurcating from a stable equilibrium. Hidden chaos with only stable equilibria can be observed from the Hopf bifurcation: a typical way to enable hidden attractors to be located. We then provide a new fuzzy controller, and a fast fuzzy disturbance observer, based on terminal sliding mode control for synchronization of the hyperchaotic system. Fuzzy inference is considered to weaken the chattering phenomena. Using Lyapunov stability theory, the stability of the closed-loop system is proved. Finally, simulations of synchronization are illustrated to show the efficient performance of the designed control method via external disturbances and dynamic uncertainties.     

Evaluating Instrument Quality in Science Education: Rasch‐based analyses of a Nature of Science test

Given the central importance of the Nature of Science (NOS) and Scientific Inquiry (SI) in national and international science standards and science learning, empirical support for the theoretical delineation of these constructs is of considerable significance. Furthermore, tests of the effects of varying magnitudes of NOS knowledge on domain‐specific science understanding and belief require the application of instruments validated in accordance with AERA, APA, and NCME assessment standards. Our study explores three interrelated aspects of a recently developed NOS instrument: (1) validity and reliability; (2) instrument dimensionality; and (3) item scales, properties, and qualities within the context of Classical Test Theory and Item Response Theory (Rasch modeling). A construct analysis revealed that the instrument did not match published operationalizations of NOS concepts. Rasch analysis of the original instrument—as well as a reduced item set—indicated that a two‐dimensional Rasch model fit significantly better than a one‐dimensional model in both cases. Thus, our study revealed that NOS and SI are supported as two separate dimensions, corroborating theoretical distinctions in the literature. To identify items with unacceptable fit values, item quality analyses were used. A Wright Map revealed that few items sufficiently distinguished high performers in the sample and excessive numbers of items were present at the low end of the performance scale. Overall, our study outlines an approach for how Rasch modeling may be used to evaluate and improve Likert‐type instruments in science education.     

Instructional guidelines based on conceptions of students and scientists about economic and population growth within planetary boundaries

International Journal of Science and Mathematics Education - The burden placed by human activities on Earth is ever-increasing. Global environmental changes have profoundly affected the...     

Newborns' face recognition: role of inner and outer facial features

Existing data indicate that newborns are able to recognize individual faces, but little is known about what perceptual cues drive this ability. The current study showed that either the inner or outer features of the face can act as sufficient cues for newborns' face recognition (Experiment 1), but the outer part of the face enjoys an advantage over the inner part (Experiment 2). Inversion of the face stimuli disrupted recognition when only the inner portion of the face was shown, but not when the whole face was fully visible or only the outer features were presented (Experiment 3). The results enhance our picture of what information newborns actually process and encode when they discriminate, learn, and recognize faces.     

Feelings and Failing in Professional Training: the assessor's dilemma

Assessing individuals as failures in education and training is rarely something that is done lightly or without misgivings. Related to this, the challenges of setting clear threshold or passing standards, are considerable. Assessors’ affective responses during fail scenarios in professional training were explored during focused interviews with 30 academic and practice staff. The pattern of feelings reported at each stage of the decision‐making process, factors which influence judgements and the reactions of others are described. The strength and spread of feelings stand out as an important sources of evidence. Understanding more about these affective responses may assist assessors as they make critical judgements at the margins of professional competence.     

Immigrant Chinese Mothers’ Socialization of Achievement in Children: A Strategic Adaptation to the Host Society

Academic socialization by low‐income immigrant mothers from Mainland China was investigated in two studies. Immigrant Chinese mothers of first graders (n = 52; M_age = 38.69) in the United States (Study 1) and kindergartners (n = 86; M_age = 36.81) in Hong Kong (Study 2) tell stories that emphasized achieving the best grade through effort more than did African American (n = 39; M_age = 31.44) and native Hong Kong (n = 76; M_age = 36.64) mothers, respectively. The emphasis on achievement was associated with mothers' heightened discussion on discrimination (Study 1) and beliefs that education promotes upward mobility (Study 2), as well as children's expectations that a story protagonist would receive maternal criticism for being nonpersistent in learning (Study 2).     

The Dutch motor skills assessment as tool for talent development in table tennis: a reproducibility and validity study

A motor skills assessment could be helpful in talent development by estimating essential perceptuo-motor skills of young players, which are considered requisite to develop excellent technical and tactical qualities. The Netherlands Table Tennis Association uses a motor skills assessment in their talent development programme consisting of eight items measuring perceptuo-motor skills specific to table tennis under varying conditions. This study aimed to investigate this assessment regarding its reproducibility, internal consistency, underlying dimensions and concurrent validity in 113 young table tennis players (6–10 years). Intraclass correlation coefficients of six test items met the criteria of 0.7 with coefficients of variation between 3% and 8%. Cronbach’s alpha valued 0.853 for internal consistency. The principal components analysis distinguished two conceptually meaningful factors: “ball control” and “gross motor function.” Concurrent validity analyses demonstrated moderate associations between the motor skills assessment’s results and national ranking; boys r = ?0.53 (P < 0.001) and girls r = ?0.45 (P = 0.015). In conclusion, this evaluation demonstrated six test items with acceptable reproducibility, good internal consistency and good prospects for validity. Two test items need revision to upgrade reproducibility. Since the motor skills assessment seems to be a reproducible, objective part of a talent development programme, more longitudinal studies are required to investigate its predictive validity.     

Exploring Online and Blended Course Delivery in Social Group Work

Agency group work has increased, but opportunities for social work group practice in educational settings have not kept pace. One option in response is technology-based learning, and students appear to have positive perceptions of online group project work. Online courses appear to have outcomes comparable to those that occur with in-person groups but require careful monitoring of group processes and group-based technologies. The authors discuss the factors involved in developing and implementing online and blended course delivery in teaching group work.     

Correlates of psychosocial adjustment in deaf adolescents with and without cochlear implants: a preliminary investigation

The number of children who have received cochlear implants (CIs) has increased dramatically in the past two decades. In view of potential concerns about their psychosocial adjustment, our aim was to assess the effect of implants on the adolescents' psychosocial functioning among a group of 57 deaf adolescents with and without CIs, using published and validated measures completed by the adolescents themselves, their parents, and teachers. Adolescents with CI tended to be more hearing acculturated, whereas those without CI tended to be more Deaf acculturated. Despite some differences in background characteristics between the two groups, there were no differences between them on the psychosocial variables assessed in this study, regardless of the reporting sources. Rather than having a direct effect on the psychosocial outcomes assessed in this study, it is through the mediating effect of acculturation and school setting that CI status exerts an influence over many of this study's outcomes. Recommendations for future research are made in light of our findings.