Study for optical manipulation of a surfactant-covered droplet using lattice Boltzmann method

In this study, we simulated deformation and surfactant distribution on the interface of a surfactant-covered droplet using optical tweezers as an external source. Two optical forces attracted a single droplet from the center to both sides. This resulted in an elliptical shape deformation. The droplet deformation was characterized as the change of the magnitudes of surface tension and optical force. In this process, a non-linear relationship among deformation, surface tension, and optical forces was observed. The change in the local surfactant concentration resulting from the application of optical forces was also analyzed and compared with the concentration of surfactants subjected to an extensional flow. Under the optical force influence, the surfactant molecules were concentrated at the droplet equator, which is totally opposite to the surfactants behavior under extensional flow, where the molecules were concentrated at the poles. Lastly, the quasi-equilibrium surfactant distribution was obtained by combining the effects of the optical forces with the extensional flow. All simulations were executed by the lattice Boltzmann method which is a powerful tool for solving micro-scale problems.     

Using log variables in a learning management system to evaluate learning activity using the lens of activity theory

As the advance of learning technologies and analytics tools continues, learning management systems (LMSs) have been required to fulfil the growing expectations for smart learning. However, the reality regarding the level of technology integration in higher education differs considerably from such expectations or the speed of advances in educational technologies. This research aimed to evaluate the current activation levels and usage patterns of a LMS. A large data-set was analysed, which included the online activity information from 7940 courses. Through data pre-processing, general indicators reflecting login frequencies of the virtual campus and activity-based indicators presenting the activation patterns of diverse functions provided by Moodle were derived. Activity theory was applied to interpret the results of analysis, since it has been recognised as a powerful framework to understand phenomena encompassing interactive systems. Further, time-series investigation over three consecutive semesters allowed observation of historical changes. The results revealed considerably low use of the virtual campus with only slight changes, as well as significantly different activity patterns across course attributes and colleges. Contradictions among components in the activity system are discussed, along with the implications for improving teaching and learning with LMS in higher education.     

Opinion Versus Knowledge: The Influence of Testimony Format on Children’s Judgments in Morally Relevant Contexts

Research Findings: To test children’s use of testimony of others, 3 – 9 years (N = 227) made judgments about a potential peer transgression in which the intentions of the protagonist were ambiguous, after hearing two different forms of testimony. The 2 forms of testimony were (a) opposing opinion-based testimony from an adult authority versus a peer consensus group and (b) knowledge-based testimony (eyewitness testimony) that was counter to the participants’ initial judgments. Findings revealed that when testimony was presented in an opinion-based format, children were likely to side with the opinion that reflected their own interpretation of the peer encounter, regardless of whether the opinion came from a peer consensus or an adult authority. However, when knowledge-based testimony was introduced in support of the opposite of children’s initial interpretation of the ambiguous peer encounter, children most often changed their initial judgment to align with the new testimony. That is, children used knowledge-based testimony but not opinion-based testimony to evaluate a potential transgression. Practice or Policy: These findings demonstrate that the way in which testimony is delivered to children has a direct influence on their decision making about peer interactions and has relevance for teacher–student discourse in the classroom.     

Mothers’ Implicit and Explicit Attitudes and Attributions in Relation to Self-Reported Parenting Behavior

Objective. Parenting behavior is presumed to be related to the thoughts about child behavior that parents report in a controlled and explicit manner and to more implicit parent cognitions that occur outside of conscious awareness and are less accessible to verbal report. Design. We examined mothers’ attitudes toward their children as correlates of self-reported parenting behavior. We used a combination of a self-report questionnaire and a reaction-time method (the Implicit Association Test) to assess explicit and implicit attitudes, respectively. We also assessed mothers’ implicit and explicit attributions for child misbehavior in relation to parenting, using a questionnaire measure of attributions completed under high-cognitive load (implicit attributions) or under low-cognitive load (explicit attributions). Mothers of 124, 6- to 10-year-olds (52% male) participated. Results. Attitudes assessed by self-report questionnaire and the Implicit Association Test were uniquely associated with negative parenting. The cognitive load manipulation moderated associations between attributions and parenting, such that child-blaming attributions were inversely associated with positive parenting only under conditions of high-cognitive load. Conclusions. Compared to traditional self-report questionnaires, methods such as the Implicit Association Test or cognitive load manipulations may more effectively assess implicit parent cognitions.     

The trend of body donation for education based on Korean social and religious culture

Until a century ago, Korean medicine was based mainly on Oriental philosophies and ideas. From a religious perspective, Chinese Confucianism was prevalent in Korea at that time. Since Confucianists believe that it is against one's filial duty to harm his or her body, given to them by their parents, most Koreans did not donate their bodies or organs for education in the past. However, by the end of the 20th century, a unique fusion of Western and Oriental medicines were produced on the Korean Peninsula, revolutionizing traditional perspectives on the human body, mortality, and the relationship of medical science to society. Koreans began to think about others' lives as well as their own by realizing the importance of donating one's organs and bodies for scientific purposes. Since then, the number of people donating their bodies to Korean medical and dental schools for the purpose of improving academic learning has increased dramatically. In response, Korean medical schools have begun to hold various types of funeral ceremonies to honor body donors. We have compared such ceremonies performed in Korea with those performed in the United States of America and Taiwan. These ceremonies are viewed as a suitable way to pay proper respect to the dead and to promote knowledge about body donation programs in Korea. Overall, the transition of religions and social ethics in Korea has greatly facilitated body bequeathal programs, benefiting both medical education and the Korean public health administration.     

Stabilizability of complex complex-valued memristive neural networks using non-fragile sampled-data control

This paper investigates the stability and stabilizability of complex-valued memristive neural networks (CVMNNs) with random time-varying delays via non-fragile sampled-data control. Taking the influence of gain fluctuations into account, a non-fragile sampled-data controller is designed for CVMNNs. Compared with the existing control schemes, the one here is more applicable and can effectively save the communication resources. The assumption on activation functions of CVMNNs is relaxed by only needing the complex-valued activation functions satisfying the Lipschitz condition. By constructing a suitable Lyapunov–Krasovskii functional (LKF), new stability and stabilizability criteria are derived for CVMNNs. Different from the existing results with the maximum absolute values of memristive connection weights, our ones are based on the average values of the maximum and minimum of the memristive connection weights. Finally, numerical simulations are given to validate the effectiveness of the theoretical results.