Assessment of the phase synchronization effect in modal testing during operation

The impact-synchronous modal analysis (ISMA), which uses impact-synchronous time averaging (ISTA), allows modal testing to be performed during operation. ISTA is effective in filtering out the non-synchronous cyclic load component, its harmonics, and noises. However, it was found that at operating speeds that coincide with the natural modes, ISMA would require a high number of impacts to determine the dynamic characteristics of the system. This finding has subsequently reduced the effectiveness and practicality of ISMA. Preservation of signatures during ISTA depends on the consistency of their phase angles on every time block but not necessarily on their frequencies. Thus, the effect of phase angles with respect to impact is seen to be a very important parameter when performing ISMA on structures with dominant periodic responses due to cyclic load and ambient excitation. The responses from unaccounted forces that contain even the same frequency as that contained in the response due to impact are diminished with the least number of impacts when the phase of the periodic responses is not consistent with the impact signature for every impact applied. The assessment showed that a small number of averages are sufficient to eliminate the non-synchronous components with 98.48% improvement on simulation and 95.22% improvement on experimental modal testing when the phase angles with respect to impact are not consistent for every impact applied.     

The effects of social supports on changes in students’ perceived instrumentality of schoolwork for future goal attainment

Research on perceived instrumentality of students’ academic work for attaining life goals has shown to have positive effects on academic achievement and motivation The purpose of the study was to examine the changes in perceived instrumentality over time and to identify how significant others such as parents, teachers and peers affect changes in perceived instrumentality. The variables of gender, prior achievement levels, academic pressure and socioeconomic status, which had significant influences on perceived instrumentality according to previous research, were used as control variables. Longitudinal data were collected for four years of 6908 students and analysed using the Growth Curve Modelling technique. Parents’ and teachers’ academic expectations and their career guidance, and social support from peers were used as predictors for changes in perceived instrumentality. Our results revealed that perceived instrumentality increased over time but in a decelerated pattern. In addition, parents and peers had significant influences on perceived instrumentality and its change, but teachers did not. The results suggest that support from parents and peers helps students to understand and internalise why they have to study hard in school to achieve their future long-term life goals.     

Korean Year 3 Children’s Environmental Literacy: A prerequisite for a Korean environmental education curriculum

The purpose of this study was to investigate Korean children’s environmental literacy levels and the variables that affect their environmental literacy. An instrument, the Environment Literacy Instrument for Korean Children (ELIKC), was developed that measures four different dimensions (knowledge, attitude, behaviour, and skills) using 69 items and 13 demographic variables. The ELIKC was administered to 969 Year 3 students from large cities, medium‐sized cities, and rural areas. The students were given 80 min to answer the questions. Statistical analysis was performed on each of the scales that make up the ELIKC and a multivariate analysis of variance was performed to identify the variables that affect environmental literacy. Results indicate that the correlation between attitude and behaviour is the strongest while that between knowledge and behaviour is the weakest. Also, it was found that gender, parents’ school background, and the source from where students obtain environmental information affect all categories of environmental literacy.     

Exploring latent class based on growth rates in number sense ability

The purpose of this study was to explore latent class based on growth rates in number sense ability by using latent growth class modeling (LGCM). LGCM is one of the noteworthy methods for identifying growth patterns of the progress monitoring within the response to intervention framework in that it enables us to analyze latent sub-groups based not on an arbitrary cut-point but on each group’s growth pattern. Progress monitoring data for number sense were administered in four times for age of 4(n = 58), 5(n = 95), and 6(n = 58) children, by the measure named basic academic skill assessment: number sense developed to assess students’ number sense and includes Number identification, Missing number, Quantity discrimination and estimation. To perform LGCM analysis, M plus 5.0 was used, and Bayesian information criteria and entropy values were used as criteria to determine the number of sub-groups. Results showed that there were 2, 4, and 4 sub-groups according to each age group based on the growth patterns. Each group’s growth patterns were classified differently based on their initial performance and growth level. Advantages and limitations of using LGCM method to analyze latent groups’ growth patterns for screening and identifying children at risk were discussed.     

Genetically encoded X-ray cellular imaging for nanoscale protein localization

Spatial resolution defines the physical limit of microscopes for probing biomolecular localization and interactions in cells. Whereas synchrotron-based X-ray microscopy (XRM) represents a unique approach for imaging a whole cell with nanoscale resolution due to its intrinsic nanoscale resolution and great penetration ability, existing approaches to label biomolecules rely on the use of exogenous tags that are multi-step and error-prone. Here, we repurpose engineered peroxidases as genetically encoded X-ray-sensitive tags (GXET) for site-specific labeling of protein-of-interest in mammalian cells. We find that 3,3^′-diaminobenzidine (DAB) polymers that are in-situ catalytically formed by fusion-expressed peroxidases are visible under XRM. Using this new tag, we imaged the protein location associated with the alteration of a DNA-methylation pathway with an ultra-high resolution of 30 nanometers. Importantly, the excellent energy resolution of XRM enables multicolor imaging using different peroxidase tags. The development of GXET enlightens the way to nanoscopic imaging for biological studies.     

Finding the optimal scaffoldings for learners’ epistemological beliefs during ill-structured problem solving

This study investigates how scaffolding type and learners’ epistemological beliefs influence ill-structured problem solving. The independent variables in this study include the type of scaffolding (task-supported, self-monitoring) and the student's epistemological belief level (more advanced, less advanced). The dependent variables include three components of problem-solving skill (problem representation, solution development, monitoring and evaluation). The two-way multivariate analysis of variance results reveal that students in the self-monitoring scaffolding group earned higher scores on problem representation and solution development than those in the task-supported scaffolding group. Students with more advanced epistemological beliefs also earned higher scores on solution development and monitoring and evaluation than did those with less advanced epistemological beliefs. In addition, a significant interaction was found between scaffolding type and epistemological belief level. These findings suggest that students can benefit from self-monitoring scaffolding in web-based problem solving and that different types of scaffolding should be provided according to the student's epistemological belief level.     

Neighborhood storytelling networks,Internet connectedness,and civic participation after the Great East Japan Earthquake

This study examines how the neighborhood storytelling network, which is conceptualized in communication infrastructure theory and includes interpersonal, organizational and community media connectedness, and an individual's Internet connectedness affected participation in civic activities in the aftermath of the Great East Japan Earthquake, which occurred on 11 March 2011. Responses from 544 randomly selected people residing in Tokyo reveal that connectedness to a neighborhood storytelling network and one's Internet connectedness have positive effects on participation in civic activities in response to the earthquake. However, the two independent factors (neighborhood storytelling and Internet connectedness) do not exhibit a significant relationship with each other. The result suggests the existence of two different conduits for civic engagement in disaster situations – neighborhood storytelling networks and Internet connectedness – mainly distinguished by age.     

The influence of unsupervised time on elementary school children at high risk for inattention and problem behaviors

In the last few decades, changing socioeconomic and family structures have increasingly left children alone without adult supervision. Carefully prepared and limited periods of unsupervised time are not harmful for children. However, long unsupervised periods have harmful effects, particularly for those children at high risk for inattention and problem behaviors. In this study, we examined the influence of unsupervised time on behavior problems by studying a sample of elementary school children at high risk for inattention and problem behaviors. The study analyzed data from the Children's Mental Health Promotion Project, which was conducted in collaboration with education, government, and mental health professionals. The child behavior checklist (CBCL) was administered to assess problem behaviors among first- and fourth-grade children. Multivariate logistic regression analysis was used to evaluate the influence of unsupervised time on children's behavior. A total of 3,270 elementary school children (1,340 first-graders and 1,930 fourth-graders) were available for this study; 1,876 of the 3,270 children (57.4%) reportedly spent a significant amount of time unsupervised during the day. Unsupervised time that exceeded more than 2 h per day increased the risk of delinquency, aggressive behaviors, and somatic complaints, as well as externalizing and internalizing problems. Carefully planned afterschool programming and care should be provided to children at high risk for inattention and problem behaviors. Also, a more comprehensive approach is needed to identify the possible mechanisms by which unsupervised time aggravates behavior problems in children predisposed for these behaviors.