225 research outputs found

    Integration of domain and resource-based reasoning for real-time control in dynamic environments

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    A real-time software controller that successfully integrates domain-based and resource-based control reasoning to perform task execution in a dynamically changing environment is described. The design of the controller is based on the concept of partitioning the process to be controlled into a set of tasks, each of which achieves some process goal. It is assumed that, in general, there are multiple ways (tasks) to achieve a goal. The controller dynamically determines current goals and their current criticality, choosing and scheduling tasks to achieve those goals in the time available. It incorporates rule-based goal reasoning, a TMS-based criticality propagation mechanism, and a real-time scheduler. The controller has been used to build a knowledge-based situation assessment system that formed a major component of a real-time, distributed, cooperative problem solving system built under DARPA contract. It is also being employed in other applications now in progress

    Angiotensin II Receptor Subtypes and Cardiac Function

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    All the components of the renin-angiotensin system have been identified in the heart including the angiotensin II receptor subtypes AT1 and AT2 In the normal human heart, there is a decreasing receptor density from the right atrium to the left ventricle. In right atrial membranes prepared from pathological hearts, the percentage of AT1 receptor decreases with the severity of cardiac dysfunction whereas that of AT2 receptor increases. Treatment of hypertrophic rats with AT1 receptor antagonists inhibits cardiac hypertrophy and reverses the increase receptor density, indicating involvement of this Ang II receptor subtype. The role of the AT2 receptor is still largely unknown but it may be involved in cell growth and proliferation. The cloning of both AT1 and AT2 receptors as well as the availability of potent and selective antagonists will help us to understand better the functional role of Angiotensin II in cardiovascular disorder

    Assessment for learning : a model for the development of a child’s self competence in the early years of education

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    In recent years policy documents, curricula and other educational initiatives have promoted a pedagogy founded on the concept of independent learning. This is broadly defined as ‘having the belief in yourself to think through learning activities, problems or challenges, make decisions about your learning and act upon those decisions (Blandford and Knowles, 2009:336). The central role of Assessment for Learning (AfL) in this process is often overlooked in practice. By considering the findings from a small scale research study this article addresses the central role of the teacher /practitioner in developing effective AfL in the early years classroom (3-5 years)

    Performance Analysis of Mobile Agents for Filtering Data Streams on Wireless Networks

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    Wireless networks are an ideal environment for mobile agents, since their mobility allows them to move across an unreliable link to reside on a wired host, next to or closer to the resources that they need to use. Furthermore, client-specific data transformations can be moved across the wireless link and run on a wired gateway server, reducing bandwidth demands. In this paper we examine the tradeoffs faced when deciding whether to use mobile agents in a data-filtering application where numerous wireless clients filter information from a large data stream arriving across the wired network. We develop an analytical model and use parameters from filtering experiments conducted during a U.S. Navy Fleet Battle Experiment (FBE) to explore the model\u27s implications

    A survey of across-target bioactivity results of small molecules in PubChem

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    This work provides an analysis of across-target bioactivity results in the screening data deposited in PubChem. Two alternative approaches for grouping-related targets are used to examine a compound's across-target bioactivity. This analysis identifies compounds that are selectively active against groups of protein targets that are identical or similar in sequence. This analysis also identifies compounds that are bioactive across unrelated targets. Statistical distributions of compound' across-target selectivity provide a survey to evaluate target specificity of compounds by deriving and analyzing bioactivity profile across a wide range of biological targets for tested small molecules in PubChem. This work enables one to select target specific inhibitors, identify promiscuous compounds and better understand the biological mechanisms of target-small molecule interactions

    Accessing the Inaccessible: Redefining Play as a Spectrum

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    Defining play has plagued researchers and philosophers for years. From describing play as an inaccessible concept due to its complexity, to providing checklists of features, the field has struggled with how to conceptualize and operationalize “play.” This theoretical piece reviews the literature about both play and learning and suggests that by viewing play as a spectrum – that ranges from free play (no guidance or support) to guided play and games (including purposeful adult support while maintaining playful elements), we better capture the true essence of play and explain its relationship to learning. Insights from the Science of Learning allow us to better understand why play supports learning across social and academic domains. By changing the lens through which we conceptualize play, we account for previous findings in a cohesive way while also proposing new avenues of exploration for the field to study the role of learning through play across age and context

    Accessing the Inaccessible: Redefining Play as a Spectrum.

    Get PDF
    Defining play has plagued researchers and philosophers for years. From describing play as an inaccessible concept due to its complexity, to providing checklists of features, the field has struggled with how to conceptualize and operationalize "play." This theoretical piece reviews the literature about both play and learning and suggests that by viewing play as a spectrum - that ranges from free play (no guidance or support) to guided play and games (including purposeful adult support while maintaining playful elements), we better capture the true essence of play and explain its relationship to learning. Insights from the Science of Learning allow us to better understand why play supports learning across social and academic domains. By changing the lens through which we conceptualize play, we account for previous findings in a cohesive way while also proposing new avenues of exploration for the field to study the role of learning through play across age and context
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