A stochastic multi-parameters divergence method for online auto-tuning of fractional order PID controllers

This paper presents a stochastic multi-parameters divergence method for online parameter optimization of fractional-order proportional–integral–derivative (PID) controllers. The method is used for auto-tuning without the need for exact mathematical plant model and it is applicable to diverse plant transfer functions. The proposed controller tuning algorithm is capable of adaptively responding to parameter fluctuations and model uncertainties in real systems. Adaptation skill enhances controller performance for real-time applications. Simulations and experimental observations are carried on a prototype helicopter model to confirm the performance improvements obtained by the online auto-tuning of fractional-order PID structure in laboratory conditions.     

Prior knowledge in mathematics and study success in engineering: informational value of learner data collected from a web-based pre-course

The article describes the development and evaluation of a web-based pre-course in mathematics, delivered to four cohorts of engineering students at a German university. Based on demographic, personal, and learning-related data relationships between students’ preconditions, their learning gains in the pre-course, and study success in the degree programme were analysed. The results support the existing literature in that domain-related prior knowledge and secondary school achievement play a dominant role regarding study success in engineering. The analyses also showed that the influence of cognitive predictors could only be compensated for by a strong learner engagement. At-risk students with high pre-course learning gains showed significantly better first-year performance. The number of self-tests a student attempted was positively related to pre-course learning gains and even to first-year performance, suggesting that this variable is a good indicator of student engagement.     

Understanding the Gaps Between Turkish Teachers’ Beliefs and Practices for Dealing With Preschoolers’ Peer Relationship Problems

Research Findings: This study explores the beliefs, self-reported practices, and observed practices of Turkish preschool teachers toward children’s peer relationship problems as well as the gap between their beliefs and practices. Five female teachers of 5-year-old children were selected as participants for this multiple case study. Approximately 79 hr of observation was conducted on the children’s daily routines and activities in a natural classroom environment, which specifically included the teachers’ problem-solving strategies while confronting peer relationship problems. The participants were also interviewed regarding their beliefs and strategies for solving peer relationship problems. The findings of this qualitative investigation indicated that the teachers’ beliefs and self-reported practices included both teacher- and child-related factors. However, the observed practices included several teacher-initiated strategies; child-initiated strategies appeared, albeit less than teacher-initiated ones. This affirms the teachers’ stress on children’s role in managing peer problems. Although some of the teacher practices and beliefs were consistent, certain inconsistencies may indicate the presence of external constraints. Practice or Policy: The results of this study highlight the importance of teacher education programs providing preservice and in-service teachers with the knowledge and skills required to understand children’s peer relationships, guide their interactions, and apply appropriate intervention strategies for various peer relationship problems.     

Vapor-liquid equilibrium simulation of binary and ternary mixtures of CH4, C2H4 and iso-C4H10

The vapor-liquid equilibrium（VLE） properties for the binary and ternary mixtures of CH4,C2H4 and isoC4H10 are of great importance in the recovery of ethylene from mixture containing CH4 and C2H4 with iso-C4H10 as solvent.Hence,Gibbs ensemble Monte Carlo（GEMC） simulations were used to estimate vapor-liquid equilibrium for the binary and ternary mixtures of CH4,C2H4 and iso-C4H10 with the united atom potential NERD model.The selected simulation conditions are based on the experiment in the literature.The results of this work were shown to be in satisfactory agreement with available experimental data and predictions of Peng-Robinson equation of state.The structure of simulated liquid phase is also characterized by radial distribution function（RDF）,which contributes to further understanding of the VLE curve of these systems.RDF is not sensitive to the pressure and temperature range.With the increase of pressure or the decrease of temperature,the molecules tend to gather together.     

发挥学会优势 服务科技创新

<正>创新是实现经济迅速发展的原动力,科协是国家推动科技事业发展的重要力量,在国家创新体系中具有独特的组织网络资源优势、特殊的主体地位和不可或缺的作用。近年来,在上级科协领导的指导和支持下,我会充分发挥学会优势,将推动科技创新摆在各项工作的首位,积极调整社会定位,充分发挥学会功能,为推进创新型城市建设做出了积极贡献。     

Stichwort: Professionelle Kompetenz von Lehrkräften

Ohne Zusammenfassung      

The Colorado Learning Attitudes about Science Survey (CLASS) for use in Biology

This paper describes a newly adapted instrument for measuring novice-to-expert-like perceptions about biology: the Colorado Learning Attitudes about Science Survey for Biology (CLASS-Bio). Consisting of 31 Likert-scale statements, CLASS-Bio probes a range of perceptions that vary between experts and novices, including enjoyment of the discipline, propensity to make connections to the real world, recognition of conceptual connections underlying knowledge, and problem-solving strategies. CLASS-Bio has been tested for response validity with both undergraduate students and experts (biology PhDs), allowing student responses to be directly compared with a consensus expert response. Use of CLASS-Bio to date suggests that introductory biology courses have the same challenges as introductory physics and chemistry courses: namely, students shift toward more novice-like perceptions following instruction. However, students in upper-division biology courses do not show the same novice-like shifts. CLASS-Bio can also be paired with other assessments to: 1) examine how student perceptions impact learning and conceptual understanding of biology, and 2) assess and evaluate how pedagogical techniques help students develop both expertise in problem solving and an expert-like appreciation of the nature of biology.     

Übereinstimmung,Variabilität und Reliabilität von Schülerurteilen zur Unterrichtsqualität auf Schulebene

Using student ratings to assess instructional quality of schools should fulfill three requirements: (1) an appropriate level of inter-rater agreement within schools, (2) systematic variance of student ratings between schools, (3) an adequate reliability level of aggregated student ratings. Using international PISA-data (2000–2012; 81 countries, over 55,300 schools, over 1.3 million 15-year olds) this study investigated how these requirements were met regarding indicators of instructional quality (classroom management, cognitive activation, individual learning support). We computed the interrater agreement index r_WG(J), as well as the intraclass correlations ICC(1) and ICC(2). Our results showed that (1) student ratings demonstrated a moderate or strong level of agreement for most indicators of instructional quality and (2) instructional quality assessed by students varied systematically between schools. Yet, (3) reliability of aggregated student ratings was not sufficient in many countries. We discuss these results regarding conventions to evaluate agreement, variability, and reliability of student ratings at the school level.     

数据新闻佳作的新闻价值与报道理念探析

随着大数据技术的不断发展,数据新闻越来越多地应用于新闻传播领域。全球数据新闻奖既是数据新闻业界“元老级”的奖项,也是权威象征。分析数据新闻奖历届获奖作品的新闻价值和报道理念,把握全球数据新闻的发展趋势,以期为我国数据新闻的发展提供参考与借鉴。