融合大小数据分析的用户画像构建

[目的/意义]本文从融合大小数据分析的角度,深入用户偏好形成的内部机理,构建包含因果关系标签的用户画像,提高其在应用中的预测能力。[方法/过程]通过大数据分析获取用户偏好的关联关系,为量表式小数据分析提供理论假设素材并获取用户偏好的因果关系,通过语义集成形成完整的用户偏好标签体系。[结果/结论]以互联网股票投资领域进行数据实验,本文所提出的理论框架和方法能够深入用户偏好形成的心理,提高用户画像分类预测的能力。     

Digital Module 10: Rasch Measurement Theory https://ncme.elevate.commpartners.com

In this digital ITEMS module, Dr. Jue Wang and Dr. George Engelhard Jr. describe the Rasch measurement framework for the construction and evaluation of new measures and scales. From a theoretical perspective, they discuss the historical and philosophical perspectives on measurement with a focus on Rasch's concept of specific objectivity and invariant measurement. Specifically, they introduce the origins of Rasch measurement theory, the development of model‐data fit indices, as well as commonly used Rasch measurement models. From an applied perspective, they discuss best practices in constructing, estimating, evaluating, and interpreting a Rasch scale using empirical examples. They provide an overview of a specialized Rasch software program (Winsteps) and an R program embedded within Shiny (Shiny_ERMA) for conducting the Rasch model analyses. The module is designed to be relevant for students, researchers, and data scientists in various disciplines such as psychology, sociology, education, business, health, and other social sciences. It contains audio‐narrated slides, sample data, syntax files, access to Shiny_ERMA program, diagnostic quiz questions, data‐based activities, curated resources, and a glossary.     

Children's understanding of the commutativity and complement principles: A latent profile analysis

This study examined patterns of individual differences in the acquisition of the knowledge of the commutativity and complement principles in 115 five-to six-year-old children and explored the role of concrete materials in helping children understand the prinicples. On the basis of latent profile analysis, four groups of children were identified: The first group succeeded in commutativity tasks with concrete materials but in no other tasks; the second succeeded in commutativity tasks in both concrete and abstract conditions, but not in complement tasks; the third group succeeded in all commutativity tasks and in complement tasks with concrete materials, and the final group succeeded in all the tasks. The four groups of children suggest a developmental trend – (1) Knowledge of the commutativity and of the complement principles seems to develop from thinking in the context of specific quantities to thinking about more abstract symbols; (2) There may be an order of understanding of the principles – from the commutativity to the complement principle; (3) Children may acquire the knowledge of the commutativity principle in the more abstract tasks before they start to acquire the knowledge of the complement principle. This study contributes to the literature by showing that assessing additive reasoning in different ways and identifying profiles with classification analyses may be useful for educators to understand more about the developmental stage where each child is placed. It appears that a more fine-grained assessment of additive reasoning can be achieved by incorporating both concrete materials and relatively abstract symbols in the assessment.     

Using characteristics of serious leisure to classify rock climbers: a latent profile analysis

The growth of the climbing industry enables more people to use this sport to promote a healthy lifestyle. Given this trend, it is important to understand the heterogeneity of rock climbers and differences in their attributes, motivations and behaviors. In this study, the characteristics of serious leisure (SL) were used to classify rock climbers. Four hundred and eighty-six rock climbers recruited in this study were classified into three groups: low commitment (LC; N?=?82), high commitment (HC; N?=?355) and dedicated groups (N?=?49). A high mean on the financial return item distinguished the dedicated group (M?=?7.52) from the other two. Subsequently, the results of multinomial logistic regression, with the dedicated group as the baseline category, showed that with increases in experiences (i.e. days of climbing in the past year and years of climbing) and internalized motivations (i.e. intrinsic, identified and introjected motivations), a climber is less relatively likely of being in the LC group. Further, comparing the HC group with the dedicated group, with increases in experiences and introjected motivation, a climber is less likely of being in the HC group. The results of the classification complemented the results of previous qualitative SL studies regarding diverse participation in leisure commitment. The results with respect to motivation supported that internalization is associated with increases in commitment. Service providers should keep current regarding dynamic climbing culture and help clients fulfill diverse needs of commitment to rock climbing. The findings of this study enhance existing knowledge of recreationists’ development in the pursuit of adventure recreation.     

Associations of newly qualified teachers’ beliefs with classroom management practices and approaches to instruction over one school year

We focus on assessing whether newly qualified teachers’ professional outcome expectations and their beliefs about students’ intellectual potential are associated with teachers’ self-reported classroom management and instructional practices. One hundred and eighteen novice teachers participating in the induction year programme were studied during their first years as full-time teachers. Results attest to a salient association between teachers’ more optimistic views of the malleability of students’ intellectual potential and teachers’ confidence in themselves as positive change agents in student outcomes. Also, teachers’ belief-set in the beginning of their career was shown to be associated with significant differences in the level of using instructional practices promoting mastery goal orientation in the classroom as well as offering students emotional support during the learning process. In the light of the significant belief–behaviour links demonstrated, more explicit attention to the sophistication of teachers’ ability beliefs in teacher education programmes is recommended.     

Adaptive number knowledge and its relation to arithmetic and pre-algebra knowledge

Traditionally measured skills with arithmetic are not related to later algebra success at levels that would be expected given the close conceptual relation between arithmetic and algebra. However, adaptivity with arithmetic may be one aspect of arithmetic competences that can account for additional variation in algebra attainment. With this in mind, the present study aims to present evidence for the existence and relevance of a newly acknowledged component of adaptivity with arithmetic, namely, adaptive number knowledge. In particular, we aim to examine whether there are substantial individual differences in adaptive number knowledge and to what extent these differences are related to arithmetic and pre-algebra skills and knowledge. Adaptive number knowledge is defined as the well-connected knowledge of numerical characteristics and relations. A large sample of 1065 Finnish late primary school students completed measures of adaptive number knowledge, arithmetic conceptual knowledge, and arithmetic fluency. Three months later they completed a measure of pre-algebra skills. Substantial individual differences in adaptive number knowledge were identified using latent profile analysis. The identified profiles were related to concurrent arithmetic skills and knowledge. As well, adaptive number knowledge was found to predict later pre-algebra skills, even after taking into account arithmetic conceptual knowledge and arithmetic fluency. These results suggest that adaptive number knowledge is a relevant component of mathematical development, and may help account for disparities in algebra development.     

Application of cDNA array for studying the gene expression profile of mature appressoria of Magnaporthe grisea

Appressorium is an infection structure of the phytopathogenic fungus Magnaporthe grisea. Analysis of gene expression profiles ofappressorium development provides insight into the molecular basis of pathogenicity and control of this fungal plant disease. A cDNA array representing 2927 unique genes based on a large EST （expressed sequence tag） database ofM. grisea strain Y34 was constructed and used to profile the gene expression patterns at mycelium and appressorium maturation stages. Compared with mycelia, 55 up-regulated and 22 down-regulated genes were identified in mature appressoria. Among 77 genes, 16 genes showed no similarity to the genome sequences of M. grisea. A novel homologue of peptidyl-prolyl cis-trans isomerase was found to be expressed at low-level in mature appressoria of M. grisea. The results indicated that the genes such as pyruvate carboxylase, phospholipid metabolism-related protein and glyceraldehyde 3-phosphate dehydrogenase involved in gluconeogenesis, lipid metabolism and glycolysis, showed differential expression in mature appressoria. Furthermore, genes such as PTHll, beta subunit of G protein and SGTI involved in cell signalling, were expressed differentially in mature appressoria. Northern blot analysis was used to confirm the cDNA array results.     

Multicultural education, pragmatism, and the goals of science teaching

In this paper, we offer an intermediate position in the multiculturalism/universalism debate, drawing upon Cobern and Loving’s epistemological pluralism, pragmatist philosophies, Southerland’s defense of instructional multicultural science education, and the conceptual profile model. An important element in this position is the proposal that understanding is the proper goal of science education. Our commitment to this proposal is explained in terms of a defense of an ethics of coexistence for dealing with cultural differences, according to which social argumentative processes—including those in science education—should be marked by dialogue and confrontation of arguments in the search of possible solutions, and an effort to (co-)live with differences if a negotiated solution is not reached. To understand the discourses at stake is, in our view, a key requirement for the coexistence of arguments and discourses, and the science classroom is the privileged space for promoting an understanding of the scientific discourse in particular. We argue for “inclusion” of students’ culturally grounded ideas in science education, but in a sense that avoids curricular multicultural science education, and, thus, any attempt to broaden the definition of “science” so that ideas from other ways of knowing might be simply treated as science contents. Science teachers should always take in due account the diversity of students’ worldviews, giving them room in argumentative processes in science classrooms, but should never lose from sight the necessity of stimulating students to understand scientific ideas. This view is grounded on a distinction between the goals of science education and the nature of science instruction, and demands a discussion about how learning is to take place in culturally sensitive science education, and about communicative approaches that might be more productive in science classrooms organized as we propose here. We employ the conceptual profile model to address both issues. We expect this paper can contribute to the elaboration of an instructional multicultural science education approach that eliminates the forced choice between the goals of promoting students’ understanding of scientific ideas and of empowering students through education.

复合结构偏心的缓变截面波导开放式同轴谐振腔电磁特性仿真研究

利用三维电磁仿真软件CST Microwave Studio,数值模拟了复合结构偏心对缓变截面波导开放式同轴谐振腔电磁特性的影响。结果表明:当内外导体的轴线同时存在平行偏心和倾斜偏心时,改变了腔体的边界条件,从而导致开放式同轴谐振腔的谐振频率、品质因数和场振幅下降,使谐振腔的有效长度(即形成驻波的长度)变短,减小了开放式同轴谐振腔回旋管振荡器中电子束与电磁波的互作用强度,使得起振时所需要的电流增大,器件的输出功率减小。复合结构偏心产生的影响比平行偏心或者倾斜偏心单独存在时更为严重。因此,在开放式缓变截面波导同轴谐振腔的实际制作过程中,应尽力避免发生复合结构偏心。     

个性化服务中用户兴趣建模与更新研究

目的:为了使用户兴趣模型更好地被推荐系统理解,实现个性化服务.方法:引入领域本体,对特征项语义进行扩展,构建电影领域本体.根据信息论思想,改进相似度的计算方法,构建基于本体的用户四元组多兴趣细粒度表示模型和相应更新机制.结果:随着用户欣赏同类电影的数量的不断增加,用户兴趣模型能进行累加学习,推荐的准确性不断提高.当用户的兴趣爱好发生转移时,用户兴趣模型能随着用户兴趣的转移合理地"遗忘"掉用户过去的爱好,而积累用户新近感兴趣的电影主题.结论:实验表明该用户兴趣模型能够准确及时地跟踪用户多种兴趣及其变化,保证用户模型的可靠性.