Post-pandemic reflections: lessons from Chinese mathematics teachers about online mathematics instruction

CAO, Yiming,Shu Zhang,Man Ching Esther Chan,Yueyuan Kang 서울대학교 교육연구소 2021 Asia Pacific Education Review Vol.22 No.2

This study investigated how teachers in China perceived the effects of online instruction on mathematics learning and examined the challenges they encountered when the country shifted to online instruction during the COVID-19 pandemic. We interviewed 152 mathematics teachers from 20 cities (municipalities) or provinces in China and adopted the four-component didactic tetrahedron model (teacher, technology, student, and mathematics) to identify their struggles with technology, teacher–student interactions, and delivery of mathematics instruction. Results showed that the teachers believed that the effectiveness of online teaching largely depends on student self-discipline. Analysis suggested a need to expand technology use during instruction, reshape the way teachers interact with students, and reorganize teaching methods in face-to-face classroom instruction. This research provided insights into integrating technology with instructional practice, the critical role of teachers in online learning, and other factors that may determine the effectiveness of online teaching.

Comparative study on two finite element models for multi-clamp pipeline system

Yiming Cao,Qingdong Chai,Xumin Guo,Hui Ma,Pengfei Wang 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.3

Due to the limitations of space and environment, a considerable number pipelines supported by multiple clamps are used in the external pipeline system of aero engines, which lead to the modeling difficulties and low efficiency. In this paper, taking U-shaped and Zshaped pipelines as examples, two methods of whole modeling and section modeling are used based on the finite element, and the piecewise linear models of clamps are introduced to compare the vibration characteristics under different boundary conditions. In addition, the simulation results are compared and verified by experiments. In the modal analysis, the coupled modes refer to the dependent modes which can influence each other through energy transfer while independent modes without energy transfer are called un-coupled modes. The results show that, for uncoupled modes of U-shaped and Z-shaped pipeline systems, the section model has smaller error and higher efficiency, which is suitable for the primary design stage of complex multi-clamp pipeline system. For the order of coupled mode, the accuracy of the whole model is high, and it is suitable for the check and vibration analysis of pipeline system. Moreover, the errors of both models decrease with the increase of tightening torque.

The Changes of Teachers` Verbal Feedback in Mathematics Classroom within Chinese Context during Ten Years

( Na Li ),( Yiming Cao ) 한국수학교육학회 2015 수학교육연구 Vol.19 No.1

In the present study, the changes of mathematics teachers`` verbal feedback between ten years ago and later were examined using a coding scheme on the types of teacher verbal feedback. Based on the analysis, it is found that teachers intend to use encouraging strategies to make responses to students ten years later. In addition, the duration used in communication between the teacher and individual student is being longer while the frequency of communication becomes less compared ten years ago. Meanwhile, the difference between good lesson ten years ago and common lesson ten years later is not so apparent. It can be inferred that the quality of teaching has being developed.

Student talk in large-size mathematics classrooms: a case study of a sequence of ten consecutive lessons in China

Lianchun Dong,Wee Tiong Seah,Yiming Cao,David Clarke 서울대학교 교육연구소 2019 Asia Pacific Education Review Vol.20 No.3

This study aims to reveal features of student talk over a sequence of consecutive mathematics lessons in a large-size class in mainland China. By examining the time allocation for student talk and the number of Chinese characters spoken by the students, this study finds that, in some of the lessons observed, student talk added up to a longer duration and included a larger number of Chinese characters than teacher talk. But individual students were observed to have unequal opportunities to participate in public talk and there is a large gap regarding the number of Chinese characters that an individual student could speak in public. Each individual student’s accountability to talk was recorded to be less diverse in public presentation than in non-presentation contexts (e.g., answering teacher questions). This study suggests that a unit of consecutive lessons can help a clearer and more comprehensive observation and analysis of student talk.

Gut-derived lipopolysaccharide promotes alcoholic hepatosteatosis and subsequent hepatocellular carcinoma by stimulating neutrophil extracellular traps through toll-like receptor 4

Yang Liu,Xin Zhang,Shuo Chen,Jiazhong Wang,Shuo Yu,Yiming Li,Meng Xu,Harouna Aboubacar,Junhui Li,Tao Shan,Jixin Wang,Gang Cao 대한간학회 2022 Clinical and Molecular Hepatology(대한간학회지) Vol.28 No.3

Background/Aims: Binge drinking leads to many disorders, including alcoholic hepatosteatosis, which is characterized by intrahepatic neutrophil infiltration and increases the risk of hepatocellular carcinoma (HCC). Molecular mechanisms may involve the migration of bacterial metabolites from the gut to the liver and the activation of neutrophil extracellular traps (NETs). Methods: Serum samples from both binge drinking and alcohol-avoiding patients were analyzed. Mouse models of chronic plus binge alcohol-induced hepatosteatosis and HCC models were used. Results: A marker of NETs formation, lipopolysaccharide (LPS), was significantly higher in alcoholic hepatosteatosis and HCC patients and mice than in controls. Intrahepatic inflammation markers and HCC-related cytokines were decreased in mice with reduced NET formation due to neutrophil elastase (NE) deletion, and liver-related symptoms of alcohol were also alleviated in NE knockout mice. Removal of intestinal bacteria with antibiotics led to decreases in markers of NETs formation and inflammatory cytokines upon chronic alcohol consumption, and development of alcoholic hepatosteatosis and HCC was also attenuated. These functions were restored upon supplementation with the bacterial product LPS. When mice lacking toll-like receptor 4 (TLR4) received chronic alcohol feeding, intrahepatic markers of NETs formation decreased, and hepatosteatosis and HCC were alleviated. Conclusions: Formation of NETs following LPS stimulation of TLR4 upon chronic alcohol use leads to increased alcoholic steatosis and subsequent HCC.

An Investigation of Student Participation in Collaborative Problem Solving in Mathematics: Positioning and Negotiation among Four Chinese Students

Shu Zhang,Man Ching Esther Chan,David Clarke,Yiming Cao 대한수학교육학회 2021 수학교육학연구 Vol.31 No.3

In this paper we report on a case study involving four Chinese students; the aim of the study was to develop a conceptual framework for investigating student participation in a collaborative task in mathematics. Building on previous research on student participation, we defined student participation in a collaborative task in mathematics as the process of taking part in student interactions and task completions. A video recording and transcript of students involved with collaborative task in mathematics were analyzed. Four categories (initiation, response, evaluation, and non-interactive) were created for analyzing the students’ interactions. The four students showed different approaches to communicating with other group members. The content of the group’s discussion was examined in terms of the negotiation process. By looking at the content of the group’s discussion, the process how the group work on the task could be revealed. We identified that students showed involvement in the group discussion by proposing and revisiting topics. It was found that through forming an interactive pair, students might be able to take up the leading role in working on the task and controlling the conversation of the group.

Influence of FeSe doping on superconducting properties of MgB2 by hybrid microwave method

Cheng Cheng,Zhenjie Feng,Qing Li,Xu Wang,Chuan Yu,Hao Chu,Ya Yang,Changqin Liu,Yiming Cao,Zhe Li,Jingzhe Chen,Chao Jing,Shixun Cao,Jincang Zhang 한국물리학회 2017 Current Applied Physics Vol.17 No.11

The effect of FeSe doping on the physical properties of MgB2 is studied. Bulk samples of the FeSe doped MgB2 with weight ratio x ðFeSe : MgB2Þ ¼ 0%; 3%; 7% and 10% were prepared by hybrid microwave method. It is proved that FeSe is not stable together with MgB2. Fe2þ enters into MgB2 lattice, some Mg2þ and Se2『 are combined into the new impurity compound MgSe. The superconducting transition temperature (Tc) slightly decreased with increasing doping content of FeSe from R-T and M-T curves, which results from the substitution of Mg2þ by Fe2þ in the MgB2 lattice. The Jc increase slightly with the FeSe doping content increasing from 3 wt % to 10 wt %, which results from the increasing MgSe impurity pinning centers.