Off line simulation system of machining processes

The primary objective for modeling of machining processes is to develop a predictive capability of machining performance in order to facilitate effective planning of machining operations. This capability leads to faster implementation, higher performance, quality at a lower cost. This comes about due to improved selection of machining parameters, optimal fixture design and the avoidance of tool failure. The simulation system presented simultaneously considers the effect of cutter geometry, the cutter's initial position errors, workpiece geometry, machine tool dynamics, and workpiece/fixture system dynamics on the machining process.The integration of all of the above in one model provides an off-line tool to simulate and optimize the machining parameters and the fixture configuration cutting both lead and production time. The modular nature of the simulation system presented allows for the study of many different machining processes. The cutting forces in this system are modeled using a mechanistic approach. NURBS curves and surfaces are utilized for the geometric modeling and simulation of the machining process. While a finite element method is used to model and analyze the workpiece/fixture dynamics. Two case studies are presented to demonstrate the practical application of the presented simulation. The first case presents the optimization of the fixture configuration of a generic automotive component. While the second case presents the results of simulations performed on a novel mill/grind machining process. This process is a combination of face milling and grinding in one operation. Some simulated results are presented along with experimental validation.     

The effect of use and access on citations

It has been shown (Lawrence, S. (2001). Online or invisible? Nature, 411, 521) that journal articles which have been posted without charge on the internet are more heavily cited than those which have not been. Using data from the NASA Astrophysics Data System (ads.harvard.edu) and from the ArXiv e-print archive at Cornell University (arXiv.org) we examine the causes of this effect.     

Socio-cultural variation in reading comprehension development among fifth graders in Peru

In this study, the socio-cultural variation in reading comprehension development was examined in 331 fifth graders from schools in Lima, Peru. Reading comprehension was measured using an adaptation of the PIRLS Reading Literacy test. The fifth graders?? reading comprehension results, measured over the course of fifth grade, were related to the development of word decoding, vocabulary, and motivation for reading. Children??s development in these domains was related to their gender, intellectual maturity, home literacy climate, and socio-economic status. Structural Equation Modelling showed that the development of reading comprehension was influenced by the children??s ability to decode words, their vocabulary, and reading motivation. Furthermore, gender and intellectual maturity as well as children??s home literacy climate and socio-economic status appeared to substantially predict reading comprehension development, directly or indirectly. More than half of the variance in reading comprehension by the end of the fifth grade could be explained based on these predictor variables.     

Patterns of contingent teaching in teacher-student interaction

The present study aimed at investigating the process of scaffolding in a naturalistic setting with focus on a key aspect of scaffolding, namely contingency. Three Social Studies teachers in innovative prevocational schools were observed and interviewed. A coding scheme for the measurement of scaffolding was developed which revealed different patterns of contingent and non-contingent teaching amongst the teachers. In general these teachers of innovative schools showed little contingent teaching. Not adapting the support to students' current understanding and barely diagnosing the students' understanding appeared to be characteristic of this scarcity of non-contingent teaching.     

SimPharm: How pharmacy students made meaning of a clinical case differently in paper‐ and simulation‐based workshops

Several scholars contend that learning with computer games and simulations results in students thinking more like professionals. Bearing this goal in mind, we investigated how a group of pharmacy students learnt with an in‐house developed computer simulation, SimPharm. Adopting situated cognition as our theoretical lens, we conducted a case study involving 20 undergraduate students to tease out how they made meaning of a clinical case differently in two different contexts: a typical paper‐based workshop and one enabled by SimPharm. The data collected included audio recordings of classroom discourse, focus group interviews and class observations. The findings identified differences in four areas: framing of the problem; problem‐solving steps and tools used; sources and meaning of feedback; and conceptualisation of the patient. These four areas can serve as axes along which future evaluations of educational simulations can be carried out based on their affordances.     

Cultural diversity in science education through Novelization: Against the Epicization of science and cultural centralization

Science educators are confronted with the challenge to accommodate in their classes an increasing cultural and linguistic diversity that results from globalization. Challenged by the call to work towards valuing and keeping this diversity in the face of the canonical nature of school science discourse, we propose a new way of thinking about and investigating these problems. Drawing on the work of Mikhail Bakhtin, we articulate epicization and novelization as concepts that allow us to understand, respectively, the processes of (a) centralizing and homogenizing culture and language and (b) pluralizing culture and language. We present and analyze three examples that exhibit how existing mundane science education practices tend, by means of epicization, towards a unitary language and to cultural centralization. We then propose novelization as a way for thinking the opening up of science education by interacting with and incorporating alternative forms of knowing that arise from cultural diversity. © 2011 Wiley Periodicals, Inc. J Res Sci Teach 48: 824–847, 2011     

II. DEVELOPMENT OF ADOPTED CHILDREN WITH HISTORIES OF EARLY ADVERSITY

This chapter first presents a review of research on the development of adopted children, focusing on meta‐analytic evidence and highlighting comparisons between adopted children with and without histories of early adversity. Some methodological issues arising from this literature are considered as well. Second, 7 longitudinal studies of adopted children's development are described, and the convergence of findings across the longitudinal studies and with the cross‐sectionally based meta‐analytic evidence is discussed. Third, the role of the adoptive family in supporting adopted children's development is explored.     

Teachers' Voices in the Context of Higher Education Reforms in Armenia

In this article, teachers' sense-making and reasoning about higher education reforms in a post Soviet country, namely Armenia, are examined using an analytical framework with six sensitising concepts: beliefs, emotions, attitudes, change knowledge, attributions and organisational culture. The results of semi-structured interviews with 12 Armenian higher education teachers showed that they mainly felt distrust towards reforms and that the implementation initiatives caused dissatisfaction, frustration and therefore distortion. At a deeper level, the teachers mostly felt excluded from the reform process and that their role was depreciated. One striking feature was the predominant causal attribution of teachers to external, unstable and uncontrollable factors which question the success of the reforms.