Browsing by Author "Wu, Wei"

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    An analysis of close seam interaction problems in the Appalachian coal fields
    Wu, Wei (Virginia Polytechnic Institute and State University, 1987)
    Mining into strata disturbed by previous mining operations either above or below may sometimes result in severe strata control problems. These interaction problems, associated with most multiple-seam mining operations, are very common in the Appalachian coal region and are the subject of this dissertation. On the basis of both theoretical and empirical analyses, using statistical analysis, numerical modeling, and photoelastic modeling methods in conjunction with the analysis of numerous case studies, a comprehensive, integrated model has been constructed and represented by a computer program called "MSEAM”. Using this comprehensive model, possible interaction problems under certain geological and mining conditions can be first predicted based on rules determined either empirically or statistically. Then, detailed analyses using different interaction mechanisms -- pillar load transfer, arching effect, upper seam subsidence, inner- burden bending, and innerburden shearing -- can further determine the area or degree of possible interaction in both under- and over-mining situations. Special geologic and mining factors controlling interaction are also summarized by indices for an independent interaction prediction. This integrated model has been validated by back·analysis of several case studies. Full descriptions of multivariate statistical analysis, photoelastic modeling technique, quantization of various interaction mechanisms, and development of the comprehensive model are included.
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    Student Approaches and Performance in Element Sequencing Tasks Using 2D and Augmented Reality Formats
    McCord, Kieren H.; Ayer, Steven K.; Perry, Logan A.; Patil, Karan R.; London, Jeremi S.; Khoury, Vanessa; Wu, Wei (MDPI, 2022-03-29)
    In civil and construction engineering education research, a focus has been on using 3D models to support students’ design comprehension. Despite this trend, the predominant mode of design communication in the industry relies on 2D plans and specifications, which typically supersede other modes of communication. Rather than focusing on the presentation of less common 3D content as an input to support students’ understanding of a design, this paper explores more common 2D inputs, but compares different visualization formats of student output in two educational interventions. In the first intervention, students document a construction sequence for wood-framed elements in a 2D worksheet format. In the second, students work with the same wood-framed design, but document their sequence through an augmented reality (AR) format where their physical interactions move full-scale virtual elements as if they were physically constructing the wood frame. Student approaches and performance were analyzed using qualitative attribute coding of video, audio, and written documentation of the student experience. Overall, results showed that the 2D worksheet format was simple to implement and was not mentally demanding to complete, but often corresponded with a lack of critical checks and a lack of mistake recognition from the students. The AR approach challenged students more in terms of cognitive load and completion rates but showed the potential for facilitating mistake recognition and self-remediation through visualization. These results suggest that when students are tasked with conceptualizing construction sequences from 2D documentation, the cognitive challenges associated with documenting a sequence in AR may support their recognition of their own mistakes in ways that may not be effectively supported through 2D documentation as an output for documenting and planning a construction sequence. The results presented in this paper provide insights on student tendencies, behaviors, and perceptions related to defining construction sequences from 2D documentation in order for educators to make informed decisions regarding the use of similar learning activities to prepare their students for understanding the 2D design documents used in industry.