Relating Latent Change Score and Continuous Time Models     

Manuel C. Voelkle  Johan H. L. Oud 《Structural equation modeling》2013,20(3):366-381

The primary goal of this article is to demonstrate the close relationship between 2 classes of dynamic models in psychological research: latent change score models and continuous time models. The secondary goal is to point out some differences. We begin with a brief review of both approaches, before demonstrating how the 2 methods are mathematically and conceptually related. It will be shown that most commonly used latent change score models are related to continuous time models by the difference equation approximation to the differential equation. One way in which the 2 approaches differ is the treatment of time. Whereas there are theoretical and practical restrictions regarding observation time points and intervals in latent change score models, no such limitations exist in continuous time models. We illustrate our arguments with three simulated data sets using a univariate and bivariate model with equal and unequal time intervals. As a by-product of this comparison, we discuss the use of phantom and definition variables to account for varying time intervals in latent change score models. We end with a reanalysis of the Bradway–McArdle longitudinal study on intellectual abilities (used before by McArdle & Hamagami, 2004) by means of the proportional change score model and the dual change score model in discrete and continuous time.  相似文献   

Carbon nanotubes for electronics manufacturing and packaging： from growth to integration     

Johan Liu  Di Jiang  Yifeng Fu  Teng Wang 《上海大学学报(英文版)》2013,(1):13-27

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Effect of substrates and underlayer on CNT synthesis by plasma enhanced CVD     

Liang Xu  Di Jiang  Yi-Feng Fu  Stephane Xavieras  Shailendra Bansropun  Afshin Ziaei  Shan-Tung Tu  Johan Liu 《上海大学学报(英文版)》2013,(3):236-240

Due to their unique thermal, electronic and mechanical properties, carbon nanotubes （CNTs） have aroused various attentions of many researchers. Among all the techniques to fabricate CNTs, plasma enhanced chemical vapor deposition （PECVD） has been extensively developed as one growth technique to produce verticallyaligned car bon nanotubes （VACNTs）. Though CNTs show a trend to be integrated into nanoelectromechanical system （NEMS）, CNT growth still remains a mysterious technology. This paper attempts to reveal the effects of substrates and un derlayers to CNT synthesis. We tried five different substrates by substituting intrinsic Si with high resistivity ones and byincreasing the thickness of SiO2 insulativity layer. And also, we demonstrated an innovative way of adjusting CNT den sity by changing the thickness of Cu underlayer.  相似文献   

School‐based ICT policy plans in primary education: Elements,typologies and underlying processes     

Ruben Vanderlinde  Sara Dexter  Johan van Braak 《British journal of educational technology : journal of the Council for Educational Technology》2012,43(3):505-519

Schools are more and more encouraged to write a school‐based information and communication technology (ICT) policy plan. In such a plan, a school describes its expectations, goals, content and actions related to the future role of ICT in teaching and learning. Although this is encouraged by researchers and policy makers, the literature on ICT policy plans and ICT policy planning is rather general and underdeveloped. In this study, the content of school‐based ICT policy plans and underlying policy processes is explored. Data were gathered in 31 primary schools in Flanders: the schools' ICT policy plan was submitted to a content analysis, and a semi‐structured interview was administered to the school leader or the ICT coordinator. Using a framework of ICT leadership practices to guide the analysis (setting direction, developing people and making the organization work), we identified three types of ICT policy plans: (1) an ICT policy plan as a vision blueprint, (2) a technical inventory and (3) a comprehensive ICT policy plan. Although the last type takes into account all ICT leadership practices, we found a variety of different approaches in the processes used to create and execute such plans, such as the support of ICT training activities, data‐driven decision‐making processes and monitoring activities.  相似文献   

The Role of Students’ Home Language in Science Achievement: A multilevel approach     

Evelien Van Laere  Koen Aesaert  Johan van Braak 《International Journal of Science Education》2013,35(16):2772-2794

The present study aimed to identify the role of both student- and school-level characteristics in primary school students’ achievement in the science curriculum. As societies become more culturally and linguistically diverse, many students enter the classroom with a home language that is different from the language of instruction used at school. This study takes into account both the home language and literacy in the language of instruction in relation to student achievement in science subjects. Questionnaires, reading performance tests, and science achievement tests were administered to 1,761 fourth-grade students from 67 schools across Flanders (Belgium). Multilevel hierarchical regression analyses show that the home language and literacy in the language of instruction play an important role in science achievement at the student level, next to gender and socioeconomic status. Students with a home language that is different from the language of instruction experience difficulties with science subjects. Moreover, the higher students’ performance on reading comprehension and self-assessed proficiency in the language of instruction, the higher their score on science achievement tests. At the school level, a school's teachability expectations are one of the key factors related to students’ science achievement. Limitations of this study and future directions for research are discussed.  相似文献   

Prisoners’ academic motivation,viewed from the perspective of self-determination theory: Evidence from a population of Norwegian prisoners     

Manger  Terje  Hetland  Jørn  Jones  Lise Øen  Eikeland  Ole Johan  Asbjørnsen  Arve E. 《International Review of Education/Internationale Zeitschrift für Erziehungswissenschaft/Revue internationale l'éducation》2020,66(4):551-574

International Review of Education - The study presented in this article explores prisoners’ academic motivation structure from the theoretical perspective of self-determination theory, using...  相似文献   

电子封装中各向异性导电胶的可靠性     

刘建影  路秀真  曹立强 《上海大学学报(英文版)》2007,11(1):1-1

Anisotropic conductive adhesive technology for electronics packaging and interconnect application has significantly been developed during the last few years. It is time to make a summary of what has been done in this field. The present paper reviews the technology development, especially from the reliability point of view. It is pointed out that anisotropic conductive adhesives are now widely used in many applications and the reliability data and models have been developed to a large extent for anisotropic conductive adhesives in various applications.  相似文献   

Explaining different types of computer use among primary school teachers   总被引：3，自引：0，他引：3  

Johan van Braak  Jo Tondeur  Martin Valcke 《European Journal of Psychology of Education - EJPE》2004,19(4):407-422

In order to identify differences in determinants of supportive and class use of computers, path modelling was applied in a sample of 468 primary school teachers. Independent variables were categorised in three levels: demographics (age and gender), computer experience (computer training, computer experience expressed over time, intensity of computer use), and attitude measures (general computer attitudes, attitudes toward computers in education, and technological innovativeness). Supportive and class use of computers are not related to the same set of variables. Supportive computer use was mainly predicted by computer experience variables and general computer attitudes. Strongest predictors of class use were technological innovativeness and gender. Yet, the degree of explained variance for class use of computer was considerably lower compared to supportive computer use. These results indicate the limitations of explaining complex forms of professional computer use on the basis of both individual determinants and quantitative models. The article concludes with some practical implications and recommendations for further research.  相似文献   

Higher education learning outcomes – Ambiguity and change in higher education          下载免费PDF全文

Joakim Caspersen  Nicoline Frølich  Johan Muller 《European Journal of Education》2017,52(1):8-19

The emerging interdependent world order poses new challenges for States and citizens alike. For States, interdependence has meant a new concern with integration, whilst for citizens and authorities alike, greater mobility has raised new concerns about recognition of competences, qualifications, quality and transparency. The introduction of learning outcomes is one of the principal instruments to achieve this in higher education. This article analyses how the implementation of higher education learning outcomes (HELOs) can be seen as ambiguous governance and management tools, manifested as parts of international policy development and policy trends. These ambiguous tools intertwine with different disciplinary and stakeholder networks. The desire to implement HELOs in a more or less uniform way across as diverse contexts (countries, disciplines, institutions) as possible has led to a design strategy that favours generic definitions of learning outcomes. In the implementation process, these generic HELOs are experienced as ambiguous, meaning that they are characterised by an openness to different interpretations. This opens up a space of discretionary and interpretational latitude, either because HELOs are assimilated to traditional path dependencies, or because they allow institutional agents (such as institutional leaders and others) the space to introduce change. The ambiguity of HELOs simultaneously provides the flexibility for contextually‐diverse implementation, ensures less comparability than initially envisaged, and opens up the possibility for change, although change is contingent on structures and processes that are external to the policy process itself. HELOs are thus a paradigm case of the centrality of context in policy implementation studies.  相似文献   

A graphical user interface for the learning of lateral vehicle dynamics     

Johan Wideberg 《European Journal of Engineering Education》2003,28(2):225-235

A graphical user interface for learning lateral vehicle dynamics has been developed. MATLAB has been used as a platform for the development of the interface. The model is based on the 'one-track' model with two degrees of freedom. With this tool the student can test different vehicle configurations in a faster and more effective way and thus enhance the understanding of vehicle dynamics.  相似文献