文本作者身份识别研究综述

[目的/意义]鉴于传统的作者身份识别方法不适用于当前大量涌现的网络文本。综述近年文本作者身份识别的典型方法和关键问题,并进行客观分析和评价,以期为进一步研究提供新的思路。[方法/过程]分别从应用领域、文体特征选取、作者身份建模和性能评价指标等方面对国内外作者身份识别相关研究现状进行客观分析,梳理相关领域研究发展脉络和趋势。[结果/结论]作者身份识别需要适应短文本、不规范文本、海量、高维和多语种环境,需更具表现和刻画能力的多层面特征和相应的作者身份建模方法,并借助信息检索、机器学习和自然语言处理领域的最新研究成果提高效率和准确率。     

三维动画模型制作的混合建模流程探讨

要制作出一个优秀的三维动画模型需要具备艺术修养和软件技术,同时不能忽略制作方法及工作流程的总结和提炼。本文分析了各种制作方法,初步提出混合建模的工作流程,以探索三维动画模型的制作方法。     

高校《数学建模》课程教学模式的探讨

数学建模课程教学模式的研究已成为数学教学研究的新课题。根据数学建模课程与一般数学课程教学目标及任务的不同,作者提出一种新的数学建模课程教学模式,即以讨论为主的教学方法、以实验为辅的教学手段、以论文为果的教学评价等。     

Modeling Growth in Electronic Learning Environments Using a Longitudinal Random Item Response Model

In educational environments, monitoring persons' progress over time may help teachers to evaluate the effectiveness of their teaching procedures. Electronic learning environments are increasingly being used as part of formal education and resulting datasets can be used to understand and to improve the environment. This study presents longitudinal models based on the item response theory (IRT) for measuring persons' ability within and between study sessions in data from web-based learning environments. Two empirical examples are used to illustrate the presented models. Results show that by incorporating time spent within- and between-study sessions into an IRT model; one is able to track changes in ability of a population of persons or for groups of persons at any time of the learning process.     

Revisiting Zhang’s scale of transactional distance: refinement and validation using structural equation modeling

Transactional distance has been defined as barriers to students’ engagement with learning in the online environment. This research updates Zhang’s (2003) scale of transactional distance, which quantified the extent of the barriers, in light of the massive changes in today’s web-based learning environment. The resulting revised scale of transactional distance (RSTD) is a parsimonious version with 12 elements (compared to 31 original) that measure the transactional distance between student and teacher, student and student, and student and content. The RSTD has excellent factorial validity and reliability, yields better fit statistics, and is easier and less time-consuming to apply. The transactional distance values are unique predictors of student satisfaction, which is correlated to learning and persistence (a major concern with massive open online courses). This information can form the basis for a systematic approach to improving the design of today’s contemporary open, flexible, distance education courses and thus serve as a valuable tool for researchers and educators alike.     

基于任务驱动的数学建模教学方法研究

通过进行数学建模竞赛的教学及培训工作,可极大地拓展学生的知识面,提高学生自己动手解决实际问题的能力,提高学生创新能力,增强学生的综合素质。主要介绍和讨论了基于任务驱动的数学建模培训及教学方法。该方法主要通过教师布置任务,鼓励学生自主地讨论并解决问题,通过自我评价和教师指导,使学生能掌握和拓展自己的知识。然后给出了具体的案例,并以淮南师范学院的建模辅导为例进行了相关的总结。     

Digital body preservation: Technique and applications

High-fidelity anatomical models can be produced with three-dimensional (3D) scanning techniques and as such be digitally preserved, archived, and subsequently rendered through various media. Here, a novel methodology—digital body preservation—is presented for combining and matching scan geometry with radiographic imaging. The technique encompasses joining layers of 3D surface scans in an anatomical correct spatial relationship. To do so, a computed tomography (CT) volume is used as template to join and merge different surface scan geometries by means of nonrigid registration into a single environment. In addition, the use and applicability of the generated 3D models in digital learning modalities is presented. Finally, as computational expense is usually the main bottleneck in extended 3D applications, the influence of mesh simplification in combination with texture mapping on the quality of 3D models was investigated. The physical fidelity of the simplified meshes was evaluated in relation to their resolution and with respect to key anatomical features. Large- and medium-scale features were well preserved despite extensive 3D mesh simplification. Subtle fine-scale features, particular in curved areas demonstrated the major limitation to extensive mesh size reduction. Depending on the local topography, workable mesh sizes ranging from 10% to 3% of the original size could be obtained, making them usable in various learning applications and environments.     

Decomposing trait and state variability in general and specific subjective task value beliefs

Expectancy-value researchers have theorized about the extent to which subjective task value components are more trait-like or more state-like. Using a bifactor representation of subjective task value data, the current study aimed to examine the degree of trait-state variation in general subjective task value, specific attainment value, specific intrinsic value, and specific utility value. The relations of both between and within components of the subjective task value constructs with academic self-efficacy beliefs were also examined. Results indicate that, in an undergraduate life science learning context (n = 169), the general subjective task value factor was the most trait-like of the subjective task value constructs. With respect to specific value beliefs, attainment value was composed of nearly equal amounts of trait and state variation, intrinsic value was composed of the largest amount of trait variation, and utility value exhibited the most state-like variation. Additionally, findings suggest that trait-like and state-like general subjective task value, trait-like specific intrinsic value, and state-like attainment value were positively associated with self-efficacy. Finally, we propose a model of trait- state dynamics in subjective task value.     

The validity of student ratings of teaching quality: Factorial structure,comparability, and the relation to achievement

Student ratings are widely used to assess teaching quality in primary and secondary education. This necessitates a thorough examination their validity and reliability in such contexts. To this end, we present validity evidence for using student ratings of teaching quality based on their factorial structure, comparability across grades and subjects, and relation to achievement. Based on data from the 2019 Trends in Mathematics and Science Study (TIMSS) and its national extensions in Norway (N = 3951 5th graders and N = 4575 9th graders), we could confirm a theoretically assumed three-dimensional factor structure (i.e., classroom management, cognitive activation, and supportive climate). Moreover, classroom management and supportive climate were more comparable across grades and subjects then cognitive activation. Finally, classroom management was associated with achievement across all groups, whereas other dimensions showed mixed results, especially across grades. Overall, the findings indicate that students, especially in Grade 9, can provide a valid assessment of teaching quality.     

车辆振动磁流变阻尼器的受力过程参数建模

应用半主动控制悬架系统提高车辆的乘座舒适性和操纵稳定性的研究受到了学术界和工业界的广泛关注。在对磁流变液体和磁流变阻尼器的特征分析的基础上,传统的车辆振动磁流变阻尼器受力分析模型以单个分析目标为主,忽略了多目标分析的需求。为此,设计了一种新的对于磁流变阻尼器性能分析的数学模型,通过简化的平板结构,得出了剪切阀式磁流变阻尼器和阀式阻尼力之和的混合环境下阻尼力参数计算公式,揭示出了阻尼力与工作电流、活塞运动速度及结构参数之间的内在联系,并以此模型为依据,进行某车型的剪切阀式磁流变阻尼器的受力分析实验,经实验研究其性能良好。