Three dimensional couette flow and heat transfer through a porous medium with variable permeability

This paper reports research on the effects of variations in injection velocity and permeability on the heat transfer and flow through a highly porous medium between two horizontal parallel plates situated at constant distance with constant suction by the upper plate. Due to this type of variation in injection velocity and in permeability the flow becomes three dimensional. The governing equations are solved by adopting complex variable notations to obtain the expressions for the velocity and temperature field. The skin-friction along the main flow direction and rate of heat transfer are discussed with the help of graphs.     

集群式计算机系统在生物信息学中的应用

1　Introduction　SMP (symmetricmulti processing)andMPP (mas sivelyparallelprocessing)arethetwotypesofstruc tureofparallelcomputing .　Symmetricmulti processingsystemshavemultipleCPUsattachedtothesamebusandsharingRAM .Massivelyparallelprocessingisthecooperated pro cessingofaprogrambymultipleprocessorsthatworkondifferentpartsoftheprogram ,witheachprocessorusingitsownoperatingsystemandmemory .ThechoicebetweenSMPandMPPdependsonthenatureoftheproblembeingsolved .Iftheproblemcanbeeasilypartit…     

Expertise Differences in the Comprehension of Visualizations: a Meta-Analysis of Eye-Tracking Research in Professional Domains

This meta-analysis integrates 296 effect sizes reported in eye-tracking research on expertise differences in the comprehension of visualizations. Three theories were evaluated: Ericsson and Kintsch’s (Psychol Rev 102:211–245, 1995) theory of long-term working memory, Haider and Frensch’s (J Exp Psychol Learn Mem Cognit 25:172–190, 1999) information-reduction hypothesis, and the holistic model of image perception of Kundel et al. (Radiology 242:396–402, 2007). Eye movement and performance data were cumulated from 819 experts, 187 intermediates, and 893 novices. In support of the evaluated theories, experts, when compared with non-experts, had shorter fixation durations, more fixations on task-relevant areas, and fewer fixations on task-redundant areas; experts also had longer saccades and shorter times to first fixate relevant information, owing to superiority in parafoveal processing and selective attention allocation. Eye movements, reaction time, and performance accuracy were moderated by characteristics of visualization (dynamics, realism, dimensionality, modality, and text annotation), task (complexity, time-on-task, and task control), and domain (sports, medicine, transportation, other). These findings are discussed in terms of their implications for theories of visual expertise in professional domains and their significance for the design of learning environments.     

Facilitating Understanding of Movements in Dynamic Visualizations: an Embodied Perspective

Learners studying mechanical or technical processes via dynamic visualizations often fail to build an accurate mental representation of the system’s movements. Based on embodied theories of cognition assuming that action, perception, and cognition are closely intertwined, this paper proposes that the learning effectiveness of dynamic visualizations could be enhanced by grounding the movements of the presentation in people’s own bodily experiences during learning. We discuss recent research on embodied cognition and provide specific strategies for how the body can be used to ground movements during the learning process: (1) making or observing gestures, (2) manipulating and interacting with objects, (3) using body metaphors, and (4) using eye movements as retrieval cues. Implications for the design of dynamic visualizations as well as directions for future research are presented.     

Theory to reality: a few issues in implementing problem-based learning

The success of an intervention depends not only upon its theoretical soundness, but also on proper implementation that reflects the guidelines derived from its theoretical conception. Debates surrounding the effectiveness of problem-based learning (PBL) have focused on its theoretical conception and students’ learning outcomes, but implementation is seemingly absent from the picture. This paper attempts to describe what research evidence is needed to fill in this missing information and provide a clearer picture of PBL. The author examines current PBL implementation practices and identifies potentially confounding variables that may play a role in inconsistent or conflicting research results in PBL. For example, various models of PBL have been developed and implemented to afford the specific instructional needs of the institution or learner population. These PBL models are in fact quite different in terms of the nature of problem solving and the degrees of self-directed learning, which theoretically, should result in different types of learning outcomes. Without distinguishing the models used, the results of comparative PBL research could have been confounded. Furthermore, human factors are another set of confounding variables that could influence the students’ learning processes and consequently affect PBL implementations and research results. To remedy these problems and reach PBL’s full potential, as well as obtain a more accurate picture of PBL as an instructional method and its effects on students’ learning, some fundamental changes are needed.     

The Challenges Facing Early Childhood Care,Development and Education (ECCDE) in an Era of Universal Basic Education in Nigeria

Early childhood is a critical period of rapid physical, cognitive, and psycho-social development of a child. The quality of care and education which a child receives at this crucial age will determine to a great extent the level of his/her physical and cognitive development in the future. In Nigeria, Early Childhood Care, Development and Education (ECCDE) is an aspect of Universal Basic Education which was introduced in 1999 to increase the access of children to basic education and improve the state of education in the country. While all hands are on deck to ensure successful implementation and achievement of the objectives of the scheme, it is unfortunate that ECCDE is facing some challenges thus making it unrecognized in Nigeria. This paper examines the challenges of early childhood education in Nigeria. To improve the situation, the following measures are recommended: establishment of more public crèche, kindergarten, and nursery schools by the government; enforcement of the use of mother tongue in the teaching of children; training more personnel in the field of early childhood education in tertiary institutions; and introducing unified curriculum as well as providing more infrastructures.     

Young Voices on Climate Change: The Paul F-Brandwein 2010 NSTA Lecture

Lynne Cherry Brandwein Lecture March 2010 National Science Teachers Association (NSTA) Conference, Philadelphia, PA. Young Voices on Climate Change: Inspired and Empowered Youth Tackle Climate Science and Find Climate Solutions. As a child, Lynne Cherry was profoundly connected to the natural world and a special place. She watched the destruction of her world. Now, through her Young Voices on Climate Change project, she is trying to give teachers and young people the tools to prevent planetary meltdown on a greater scale. Global climate change is upon us and the need for education and action is immediate. Outreach, visual storytelling, and scientific understanding are especially necessary in light of the recent polls that show that the public is becoming more confused and less concerned about climate change. Cherry’s climate book, co-authored with photojournalist Gary Braasch, and her Young Voices on Climate Change films feature climate solutions. They’re about win–win—save the environment, protect human health, reduce global warming gases, demonstrate youth making a difference with practical tools, motivate engagement in climate science, take pride in increased science literacy, reach young people through their hearts as well as their minds, and save money. Although young people can help their parents, peers and communities understand climate science, they can also show them that reducing CO₂ is in their economic interest, and spur them to take action. School carbon reduction initiatives are spilling over into communities yielding measurable results in both global warming gas reductions and significant monetary savings.     

Reclaiming Kindergarten: Part II: Questions About Policy

Part II of “Reclaiming Kindergarten” continues the discussion related to responding to the crisis in today’s kindergarten. In Part II, two policy questions are posed, the answers to which seek to respond to this continuing crisis. The questions center on issues related to engaging families in kindergarten and the need to consider a new early childhood paradigm where kindergarten is part of a continuous and seamless educational experience spanning prekindergarten through third grade. As in Part I, examples of classroom practice are used to illustrate the effective implementation of these principles in a kindergarten classroom.     

Facing multiculturalism’s challenges in Korean education and society

Multicultural policy in South Korea faces variants of challenges endemic to multiculturalism. These challenges are “dilemmas of difference,” “variable terms of inclusion,” and “legitimacy.” In Korea, these challenges arise in a setting in which ethnic diversity is of relatively recent origin, an ideology of ethnic homogeneity is prevalent, and official multicultural policy is limited in its reach to those who are designated as “multicultural families,” that is families in which one spouse is Korean and the other an immigrant, usually the wife, and their offspring. The exclusion of migrant workers and their families from Korea’s multicultural framework poses a core contradiction in Korean multicultural policies. This contradiction must be resolved if multiculturalism in education and other spheres is to promote equality and provide a foundation for national integration on terms that are equitable to the diverse constituents of Korean society. Inevitably, this will require a redefinition of what it means to “be Korean.” Even if multicultural policies fall short in their immediate effects on those toward whom they are directed, multiculturalism represents a significant shift in the discourse of Korean identity and will be terrain on which the status of diverse groups in Korea will be contested.