Exploring the Influencing Factors and Validity of Formative Assessment in Online Learning

Online learning is increasingly popular as the pandemic spreads around the globe. This shift in learning preferences presents opportunities and difficulties for the assessment of learning. As a method of assessment used throughout the learning process, formative assessment can encourage students' interest in learning, enhance learning outcomes, support teachers' strategic planning and maximize teaching results. However, the effectiveness of online formative assessment has been questioned. This study uses a qualitative research methodology based on Grounded Theory to analyze the validity of formative assessment in online learning by examining the factors unique to online learning that affect it. After reviewing previous studies and interviewing 45 online learners, this paper three-level-coded the sources and analyzed them. Findings show that the validity is influenced by the lack of functional alienation caused by the effects of the subject's emotional game and adaptability, objective environment and technology and poor interaction. To help implement formative assessment in real classroom practices, two models were established based on the findings, namely the Formative Assessment Model (FAM) and Online Formative Assessment Validity Model (OFAV). This study asks about the influence factors and explores how much the validity of formative assessment shows in online practice, and provides new feasible ideas and suggestions for the future development of the field of educational assessment

Geometrical effects of a subducted seamount on stopping megathrust ruptures

Author Posting. © American Geophysical Union, 2013. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geophysical Research Letters 40 (2013): 2011–2016, doi:10.1002/grl.50509.We have numerically simulated dynamic ruptures along a “slip-weakening” megathrust fault with a subducted seamount of realistic geometry, demonstrating that seamounts can act as a barrier to earthquake ruptures. Such barrier effect is calculated to be stronger for increased seamount normal stress relative to the ambient level, for larger seamount height-to-width ratio, and for shorter seamount-to-nucleation distance. As the seamount height increases from 0 to 40% of its basal width, the required increase in the effective normal stress on the seamount to stop ruptures drops by as much as ~20%. We further demonstrate that when a seamount is subducted adjacent to the earthquake nucleation zone, coseismic ruptures can be stopped even if the seamount has a lower effective normal stress than the ambient level. These results indicate that subducted seamounts may stop earthquake ruptures for a wide range of seamount normal stress conditions, including the case of the thrust fault being lubricated by seamount-top fluid-rich sediments, as suggested from observations in the Japan and Sunda Trenches.This work was supported by NSF grant EAR-1015221 and WHOI Deep Ocean Exploration Institute awards 27071150 and 25051162

Study on the influence mechanism and level measurement of agricultural green development—A case study of China

Taking China as an example, this paper analyzes the impact mechanism of agricultural green development and constructs a measurement system of agricultural green development level. The system includes seven subsystems (ensuring food security, optimizing agricultural structure, improving market mechanism, innovation-driven development, building ecological civilization, inheriting traditional culture, and benefiting the people) and 55 measurement indicators. Empirical research was carried out using entropy method and gray correlation to measure the level of green development of China's agriculture, analyze its spatial distribution law, and divide it into three levels according to the development level, then analyze the regional characteristics of each grade. The research shows that the overall level of agricultural green development in China is relatively low, and the constraints are obvious. It is easy to ignore the value of agricultural green development, and the phenomenon of non-green development still exists. Therefore, we must attach great importance to the green development of agriculture, change agricultural production from the pursuit of quantity to the pursuit of quality in the past, formulate an effective path to promote the comprehensive level of agricultural green development in the whole ecological chain, and build a collaborative research institution and information monitoring platform for agricultural green development

An Information-Theoretic Framework for Evaluating Edge Bundling Visualization

Edge bundling is a promising graph visualization approach to simplifying the visual result of a graph drawing. Plenty of edge bundling methods have been developed to generate diverse graph layouts. However, it is difficult to defend an edge bundling method with its resulting layout against other edge bundling methods as a clear theoretic evaluation framework is absent in the literature. In this paper, we propose an information-theoretic framework to evaluate the visual results of edge bundling techniques. We first illustrate the advantage of edge bundling visualizations for large graphs, and pinpoint the ambiguity resulting from drawing results. Second, we define and quantify the amount of information delivered by edge bundling visualization from the underlying network using information theory. Third, we propose a new algorithm to evaluate the resulting layouts of edge bundling using the amount of the mutual information between a raw network dataset and its edge bundling visualization. Comparison examples based on the proposed framework between different edge bundling techniques are presented

Performance Analysis of Friction Stir Welded Lightweight Aluminum Alloy Sheet

The present research envisaged the performance analysis of a 1-mm thick 6061-T6 aluminum alloy sheet welded by the friction stir welding technique, using optical microscopy, micro-hardness measurement, a tensile test, a friction and wear test, and a salt spray corrosion test. It was found that the grain in the welded zone obtained was refined under each parameter. When the rotating speed of the tool was 15,000 rpm and the traveling speed of the tool was 300 mm·min-1, the tensile strength of the welded zone was highest, i.e. 74.8% of the base metal. Furthermore, the hardness distribution curve of the welded zone was of the 'W' type under each parameter, but the hardness value was lower than that of the base metal. The friction coefficient of the welded zone was lower than that of the base metal under each parameter, and the wear form was found to be mainly adhesive wear accompanied by abrasive wear. The welded zone and the base metal were subjected to salt spray corrosion after 12 hours under each parameter, which had a negative effect on the quality. However, after 12 hours of subsequent corrosion, the quality of each sample and the base material was not obvious

Application of Fibonacci Sequence and Lucas Sequence on the Design of the Toilet Siphon Pipe Shape

The purpose of this study was to explore the method for designing the toilet siphon pipe shape to improve flushing performance. The Fibonacci sequence and the Lucas sequence were used to design the structural parameters of the siphon pipe. The flushing processes of the toilet were simulated using the computational fluid dynamics (CFD) method to analyze the flushing performance under different siphon pipe shapes. Experimental studies were conducted to verify the reliability of the simulation results. The results indicated that when the Lucas numbers and the Fibonacci numbers were utilized to regulate the curvature of the siphon pipe in the Xi direction and the Yj direction respectively, the flushing performance of the toilet was optimal. In order to obtain better flushing performance, the curvature of the siphon pipe should be smooth and have obvious transitions at the connections of different sections. When the overall size of the siphon pipe is kept constant, a short siphon pipe length is helpful for the improvement of toilet flushing performance

Output Information Based Fault-Tolerant Iterative Learning Control for Dual-Rate Sampling Process with Disturbances and Output Delay

For a class of single-input single-output (SISO) dual-rate sampling processes with disturbances and output delay, this paper presents a robust fault-tolerant iterative learning control algorithm based on output information. Firstly, the dual-rate sampling process with output delay is transformed into discrete system in state-space model form with slow sampling rate without time delay by using lifting technology; then output information based fault-tolerant iterative learning control scheme is designed and the control process is turned into an equivalent two-dimensional (2D) repetitive process. Moreover, based on the repetitive process stability theory, the sufficient conditions for the stability of system and the design method of robust controller are given in terms of linear matrix inequalities (LMIs) technique. Finally, the flow control simulations of two flow tanks in series demonstrate the feasibility and effectiveness of the proposed method