Agency to Transform: How Did a Grade 5 Community Co-Configure Dynamic Knowledge Building Practices in a Yearlong Science Inquiry?

This study explores emergent reflective structuration as a new form of shared regulation. The purpose is to support students in taking on high-level epistemic agency as they co-configure dynamic inquiry pathways that unfold over long periods of time. With the teacher’s support, students not only regulate their inquiry and collaboration following pre-scripted structures, but they also co-construct shared inquiry pathways to frame and reframe their community practices in response to progress and needs that emerge over time. Our data analysis investigates the temporal and interactional processes by which members of a Grade 5 classroom co-configured their knowledge building pathways in a yearlong science inquiry focusing on the human body systems. As a co-constructed structure, students co-formulated an evolving chart of “big questions” that signified shared inquiry directions with the teacher’s support. The inquiry process was supported by Knowledge Form and Idea Thread Mapper, which visualizes the online knowledge building discourse based on temporal streams of inquiry focusing on the “big questions.” Qualitative analysis of classroom observation notes, videos, student artifacts, online discourse, and student interviews documented nine “big questions” co-formulated by the community over time. Further analysis revealed students’ agentic moves to expand, deepen, and reframe the knowledge building work of their community. Analyses of online discourse and a pre-and post-test showed productive idea contributions, interactions, and knowledge outcomes. Conceptual and practical implications are discussed

Epistemic agency for costructuring expansive knowledge-building practices

As a hallmark of authentic science practices, students need to enact epistemic agency to shape/reshape the key aspects of their inquiry work as a collaborative community. This study elaborates an emergent temporal mechanism for engaging students\u27 epistemic agency: “reflective structuration” by which members of a classroom community coconstruct ever-evolving inquiry directions and group structures as their collective inquiry work proceeds. Using an interactional ethnography method, we examined how students (n = 22) in a Grade 5 classroom coconstructed shared inquiry directions and flexible group structures to guide their sustained inquiry about human body systems over 7 months supported by a collaborative online environment. Rich data were collected to trace the work of the eye inquiry group as a telling case. With their teacher\u27s support, students took agentic moves to construct an evolving set of wondering areas as a way to frame what their whole class needed to investigate. Flexible groups, such as the eye inquiry group, emerged and evolved in the various areas, leading to progressively deepening inquiry and extensive idea exchanges among students. Implications for research and practice are discussed

Machining-path mapping from free-state to clamped-state for thin-walled parts

Thin-walled parts with curved surface are widely used in industrial applications and the high-quality machining is still a major problem because of the low stiffness. By using the machining-path obtained from the design model of thin-walled parts with curved surface, the machining accuracy requirement may easily not be met due to the springback of clamping deformation when the machining process is finished. It is a novel idea that when the machining-path mapping from free-state to clamped-state is realized based on the clamping deformation, the final machining-path of thin-walled parts can be re-designed to directly ensure the machining accuracy requirement after the fixture is released. Based on the concomitant thought of curved surface and the elastic deformation theory of thin shell in this study, the mathematical model for the machining-path mapping from free-state to clamped-state is established for the thin-walled parts with curved surface. Then, the corresponding relationship of cutter contact (CC) points is calculated by grid mapping. Finally, the machining-path for the thin-walled parts with curved surface is re-designed under the clamped-state. Taking a thin-walled cylinder workpiece as an example, the experiment results show that the proposed method can achieve the avoiding purpose for the machining error caused by clamping deformation. These research achievements are of vital importance for realizing high-quality machining of the thin-walled parts with curved surface

Microstructure measurement and microgeometric packing characterization of rigid polyurethane foam defects

Streak and blister cell defects pose extensive surface problems for rigid polyurethane foams. In this study, these morphological anomalies were visually inspected using 2D optical techniques, and the cell microstructural coefficients including degree of anisotropy, cell circumdiameter, and the volumetric isoperimetric quotient were calculated from the observations. A geometric regular polyhedron approximation method was developed based on relative density equations, in order to characterize the packing structures of both normal and anomalous cells. The reversely calculated cell volume constant, Cc, from polyhedron geometric voxels was compared with the empirical polyhedron cell volume value, Ch. The geometric relationship between actual cells and approximated polyhedrons was characterized by the defined volumetric isoperimetric quotient. Binary packing structures were derived from deviation comparisons between the two cell volume constants, and the assumed partial relative density ratios of the two individual packing polyhedrons. The modelling results show that normal cells have a similar packing to the Weaire-Phelan model, while anomalous cells have a dodecahedron/icosidodecahedron binary packing

Emerging Spatio-temporal Hot Spot Analysis of Beijing Subsidence Trend Detection Based on PS-InSAR

Scholars have done a lot of research on urban settlement, but it is difficult to give consideration to the temporal and spatial attributes of settlement at the same time in its display and analysis. Most of them focused on the analysis of regional settlement, single point settlement curve and settlement rate map at a certain time, but few combined time and space for collaborative analysis. Therefore, in this paper, 32 scenes Sentinel-1B SAR data are used to obtain settlement data of Beijing via PS-InSAR method. Secondly, combined with the temporal and spatial attributes of settlement results, the subsidence law revealed by using spatio-temporal cube slicing and attribute filtering. Finally, subsidence development trend and the detection of abnormal subsidence are explored by emerging hot spots (ESH) analysis. The experimental results show that the settlement funnel center in Beijing is mainly concentrated near the junction of Chaoyang district and Tongzhou district. The settlement range tends to expand. There are several local continuous subsidence areas in the settlement oscillating area. Spatio-temporal analysis makes the development trend of urban settlement more intuitive. Emerging hotspot analysis combined with Getis-Ord Gi* statistics and Mann-Kendall trend test could more effectively analyze the settlement trend of the study area and detect new potential settlement centers, so that to provide auxiliary decision-making for urban safety early warning and city development

Co-Organizing the Collective Journey of Inquiry with Idea Thread Mapper

This research integrates theory building, technology design, and design-based research to address a central challenge pertaining to collective inquiry and knowledge building: How can student-driven, ever-deepening inquiry processes become socially organized and pedagogically supported in a community? Different from supporting inquiry using predesigned structures, we propose reflective structuration as a social and temporal mechanism by which members of a community coconstruct/reconstruct shared inquiry structures to shape and guide their ongoing knowledge building processes. Idea Thread Mapper (ITM) was designed to help students and their teacher monitor emergent directions and co-organize the unfolding inquiry processes over time. A study was conducted in two upper primary school classrooms that investigated electricity with the support of ITM. Qualitative analyses of classroom videos and observational data documented the formation and elaboration of shared inquiry structures. Content analysis of the online discourse and student reflective summaries showed that in the classroom with reflective structuration, students made more active and connected contributions to their online discourse, leading to deeper and more coherent scientific understandings