• Journal of Educational Research in Mathematics
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• v.19 no.3
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• pp.425-441
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• 2009

The cube-accumulation is a new theme included in the 7th elementary mathematics curriculum for improving children's spatial ability. One activity of the cube-accumulation is to recognize the configuration of accumulated cube given three plane figures in the directions of the above, the front and the side, respectively. The approach to this activity presented in the mathematics textbook is more or less intuitive and constructive, and difficult to some children. So we suggest an alternative, more analytic method, 'elimination method', that is eliminating unnecessary parts from $n{\times}n{\times}n$ whole cubes. This method was adopted to the 32 sixth graders, in special five applicants among them. Their responses and activities were analyzed. We confirm that we can teach the cube-accumulation by the elimination method, and some children prefer this method. 13u1 this method requires more exercises to be executed skillfully.

• Wind and Structures
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• v.37 no.1
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• pp.25-38
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• 2023

Due to the complexity and difficulty in meeting the multiphase flow complexity, similarity, and multiscale characteristics, the mechanism of snow drift is so complicated that the snow deposition prediction is still inaccurate and needs to be far improved. Meanwhile, the validation of prediction methods is also limited due to a lack of field-measured data about snow deposition. To this end, a field measurement activity about snow deposition around a cube with time was carried out, and the snow accumulation process was measured under blowing snow conditions in northwest China. The maximum snow depth, snow profile, and variation in snow depth around the cube were discussed and analyzed. The measured results indicated three stages of snow accumulation around the cube. First, snow is deposited in windward, lateral and leeward regions, and then the snow depth in windward and lateral regions increases. Secondly, when the snow in the windward region reaches its maximum, the downwash flow erodes the snow against the front wall. Meanwhile, snow range and depth in lateral regions have a significant increase. Thirdly, a narrow road in the leeward region is formed with the increase in snow range and depth, which results in higher wind speed and reforming snow deposition there. The field measurement study in this paper not only furthers understanding of the snow accumulation process instead of final deposition under complex conditions but also provides an important benchmark for validating prediction methods.