Mining direct antagonistic communities in signed social networks

Social networks provide a wealth of data to study relationship dynamics among people. Most social networks such as Epinions and Facebook allow users to declare trusts or friendships with other users. Some of them also allow users to declare distrusts or negative relationships. When both positive and negative links co-exist in a network, some interesting community structures can be studied. In this work, we mine Direct Antagonistic Communities (DACs) within such signed networks. Each DAC consists of two sub-communities with positive relationships among members of each sub-community, and negative relationships among members of the other sub-community. Identifying direct antagonistic communities is an important step to understand the nature of the formation, dissolution, and evolution of such communities. Knowledge about antagonistic communities allows us to better understand and explain behaviors of users in the communities.     

Meritocracy,elitism, and egalitarianism: a preliminary and provisional assessment of Singapore's primary education review

Meritocracy functions in Singapore as the key principle of governance and educational distribution. However, the concept of meritocracy itself contains a number of inherent contradictions, most evidently witnessed in the tension between its egalitarian and elitist strands. This tension is documented in the recommendations of Singapore's recent primary education review, already accepted by the Ministry of Education and to be implemented in the coming years. This article considers these recommendations against the backdrop of a tentative movement towards egalitarianism in educational distribution. Specifically, it provides a preliminary and provisional assessment of how far they would go towards providing for greater educational equity and, therefore, in recovering the ideology of meritocracy in the nation-state.     

Gender,toys and learning

In spite of continuing patterning of curriculum subject preference and choice by gender, there has been little recent attention to the argument developed in the 1970s that children play with different toys according to their gender, and that these provide girls and boys with (different) curriculum‐related skills. The article describes a small‐scale empirical study that asked parents of 3–5 year old children to identify their child’s favourite toys and viewing material, and analysed responses according to children’s gender. The most frequently identified toys and viewing materials were subjected to content and discourse analysis, with the intention of identifying both educative aspects of content, and the gender discourses reflected. The article explores conceptual issues around categorisations of ‘education’ within toys and entertainment resources, positing the notion of ‘didactic information’ to delineate between overtly educational content and other social discourses. Analysis reveals toy preferences to be highly gendered, with boys’ toys and resources concentrated on technology and action, and girls’ on care and stereotypically feminine interests. Didactic information, and aspects developing construction and literacy skills, were identified in the selected toys and resources for boys, and were lacking in those for girls. All the toys and resources could be read as implicated in ‘gendering’: the various gender discourses, and other discourses around aspects of social identity reflected in the toys and resources are identified and analysed. The analysis presented suggests the value of reinvigorated attention to children’s toys and entertainment resources in terms both of the education they afford, and their role in the production of social identities.     

Preparing Elementary Pre-Service Teachers from a Non-Traditional Student Population to Teach with Technology

This article documents the development of a two-stage curriculum intended to improve elementary teacher candidates’ understanding of technology integration. Most students in the program came from low-income districts and lacked technology experience. The first stage of the curriculum consisted of a prerequisite basic technology skills course offered by the Computer Science Department. This was then followed by an online educational technology course offered by the College of Education. The objectives of the authors in this article are twofold. The first is to describe the rationale, procedures, and design of a two-stage curriculum, as a pedagogical model for teaching elementary teacher candidates to teach with technology, with the goal of preparing a new generation of teachers who are capable and comfortable applying a broad range of advanced technologies to meet the learning needs of their students. The second objective is to share the authors' findings from the evaluation, which employed mixed methodologies, after the students completed the online educational technology course. The results showed that an online educational technology course contributed to the candidates’ development of Technological Pedagogical Content Knowledge and improved their attitudes and beliefs on their technology integration practices.     

Automated impact device with non-synchronous impacts: a practical solution for modal testing during operation

Previous study has shown that synchronization of phases between impacts and the cyclic load component should be avoided to improve the effectiveness of operational modal testing, i.e. impact-synchronous modal analysis in obtaining a cleaner frequency response function (FRF) estimation with fewer number of averages. However, avoiding the phase synchronization effect is rarely achievable with the current manual impact hammer because of the lack of control of the impact timing. We investigate how to improve FRF estimation in the presence of harmonic disturbances, such as those present in operating rotating machines. An auto impact device is therefore introduced to replace the manual impact hammer. This device ensures that impact intervals can be applied at non-synchronous instances with respect to the harmonic disturbance. We demonstrate that this new device is a viable option for operational modal testing. It allows significant improvement in FRF estimation and shows good correlation of modal extraction data with benchmark experimental modal analysis results.     

Robust mixed H2/H∞ model predictive control for Markov jump systems with partially uncertain transition probabilities

This paper addresses the control problem for a class of discrete-time Markov jump linear systems with partially unknown transition probabilities using model predictive controller subject to external disturbances and input constraints. Our focus is on the design of a model predictive controller to stabilize the system with a given mixed H₂/H_∞ performance index. Sufficient conditions are derived in terms of a set of linear matrix inequalities. Examples are presented to demonstrate the effectiveness of the proposed controller design method.     

Pre-movement and during-movement visual search behaviours vary depending on expertise and anxiety levels in ten-pin bowling

This study investigated the pre-movement and during-movement visual search behaviour (VSB) and quiet eye (QE) of 11 elite versus 10 sub-elite ten-pin bowlers, performing under high-anxiety and low-anxiety conditions. Pre-movement and independent of expertise, bowlers had more fixations and directed them to more locations when performing under high-anxiety compared with low-anxiety. Elite bowlers fixated at more locations closer to the pins in pre-movement than during-movement, with pre-movement QE occurring mostly at the breakpoint and middle arrows. During movement however, bowlers fixated closer to the foul-line at the middle and right dots and arrows, with during-movement-QE occurring at the middle dots and right arrows. Elite bowlers recorded longer QE durations during-movement rather than pre-movement, albeit a later onset during the longish five-step approach prior to ball release compared with sub-elite bowlers. Our results suggest that QE during-movement instead of pre-movement could be more pertinent in differentiating expertise during sporting tasks with a long movement phase and far-aiming target. The relevance of pre-movement or movement-QE in characterising expertise and performance could therefore be sport-dependent. This should be considered when investigating skilled action and developing training programs for skill acquisition.     

Unpacking the hidden efficacies of learning in productive failure

This paper describes a framework for learning where learners undergo experimentations with the phenomena at hand according to progressive and staged goals. Bowling is used as a case study in this paper. The premise for experimentations is that learners can experience hidden efficacies, including the formation of “bad habits.” A distinction is made between productivity in learning and performance in terms of learning outcomes. In other words, productivity in learning may not necessarily manifest in successful performance, hence the term productive failure. To emphasize the need for self-regulation during problem-solving process, we discuss the movements within the productive–unproductive and success–failure dimensions through three-staged self-regulatory processes and draw implications to learning and instruction.     

A “Chameleonic” Identity: Foreign-Born Doctoral Students in U.S. Counselor Education

This study explored the interplay between a multidimensional model of acculturation and professional identity development among eight foreign-born doctoral students in U.S. counselor education. Themes generated through an interpretive phenomenological analysis revealed that the participants, while trying to adapt to the Euro-American cultural context of their counselor programs, experienced a sense of conflict, loss, and grief, resulting in what they called a “chameleonic” professional identity. Findings illustrated that for international counseling students, professional identity development is an arduous and complex process deeply intertwined with their acculturation experiences. Implications for counselor programs and future research are further discussed.     

Students’ understanding of voltage in simple parallel electric circuits

This paper reports an investigation of the performance of school students at age 15 on written diagnostic questions involving the prediction of meter readings in simple electric circuits with parallel branches. Results show that these students tend to perceive such questions in resistance‐current terms, with a primary focus on resistor addition, rather than in voltage terms, with two loads being driven from the same source. Common errors in predicting voltages across parallel branches suggest that few students use a mental model of voltage in approaching parallel circuit problems but instead attempt to solve problems by mechanical use of the V=IR equation. Implications for the teaching of electric circuits at this level are identified.