4,473 research outputs found

    An autonomous satellite architecture integrating deliberative reasoning and behavioural intelligence

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    This paper describes a method for the design of autonomous spacecraft, based upon behavioral approaches to intelligent robotics. First, a number of previous spacecraft automation projects are reviewed. A methodology for the design of autonomous spacecraft is then presented, drawing upon both the European Space Agency technological center (ESTEC) automation and robotics methodology and the subsumption architecture for autonomous robots. A layered competency model for autonomous orbital spacecraft is proposed. A simple example of low level competencies and their interaction is presented in order to illustrate the methodology. Finally, the general principles adopted for the control hardware design of the AUSTRALIS-1 spacecraft are described. This system will provide an orbital experimental platform for spacecraft autonomy studies, supporting the exploration of different logical control models, different computational metaphors within the behavioral control framework, and different mappings from the logical control model to its physical implementation

    Early aerospaceplane propulsion research: Marquardt Corporation: ca 1956-1963

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    A brief summary is presented of the very early days of aerospaceplane propulsion and concept research, from a viewpoint based in the Astro Division of Marquardt Aircraft Co. in the years listed, with some view into later times that were on Bill Escher's watch and others. Other groups who were pursuing the same goals by various routes are discussed by some following speakers. The chief purpose is to bring out background information that may be of value to members of the workshop and future workers in the field. The state of engine and airframe technology at those times must be understood to make sense of the effort. Operational kerosene fueled ramjets were routinely flying Mach 2 to 3 in the Bomarc and Talos interceptors. One Marquardt ramjet had accelerated a Lockheed X-7 test vehicle to about Mach 4.7 in an all-out test, holding it at nearly 1 'G' until the fuel ran out. Development of further research at Marquardt is outlined

    Gameplay experience in a gaze interaction game

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    Assessing gameplay experience for gaze interaction games is a challenging task. For this study, a gaze interaction Half-Life 2 game modification was created that allowed eye tracking control. The mod was deployed during an experiment at Dreamhack 2007, where participants had to play with gaze navigation and afterwards rate their gameplay experience. The results show low tension and negative affects scores on the gameplay experience questionnaire as well as high positive challenge, immersion and flow ratings. The correlation between spatial presence and immersion for gaze interaction was high and yields further investigation. It is concluded that gameplay experience can be correctly assessed with the methodology presented in this paper.Comment: pages 49-54, The 5th Conference on Communication by Gaze Interaction - COGAIN 2009: Gaze Interaction For Those Who Want It Most, ISBN: 978-87-643-0475-

    ATP-sensitive K⁺ transport in rat pancreatic zymogen granule membranes and activation by protein kinase A.

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    Includes bibliographical references.Pancreatic secretory granules contain electrolyte transport pathways for Cl⁻ and K⁺ that may contribute to exocyto- tic membrane fusion or net fluid secretion following membrane fusion. Recently the granule K⁺ transport pathway was shown to exhibit characteristics of the ATP-sensitive K⁺ channels which include inhibition by ATP. K⁺ transport by the zymogen granule membrane was measured indirectly following K+ dependent osmotic swelling and ionophore-induced lysis of the granule while incubated in KC1 and sucrose solutions, pH 7.0, at 37°C. This lysis rate was K⁺ dependent and ATP inhibited. The results also show that this granule K⁺ transport pathway can be activated by cAMP- dependent protein kinase phosphorylation. ATP reduced the K⁺ dependent rate in a dose dependent manner. Subsequent incubation of apical plasma membranes with 15 units/ml of the catalytic subunit of protein kinase A restored K⁺ transport in fusion experiments. Although protein kinase C induced K⁺ transport was not elevated over control levels, the results of protein kinase A stimulated K⁺ transport support the assertion of ATP-sensitive K⁺ transport by secretory granules. This suggests a mechanism for the regulation of secretory granules consistent with the known signaling mechanisms controlling stimulus-secretion coupling in pancreatic acinar cells.B.S. (Bachelor of Science

    Trends and Techniques in Visual Gaze Analysis

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    Visualizing gaze data is an effective way for the quick interpretation of eye tracking results. This paper presents a study investigation benefits and limitations of visual gaze analysis among eye tracking professionals and researchers. The results were used to create a tool for visual gaze analysis within a Master's project.Comment: pages 89-93, The 5th Conference on Communication by Gaze Interaction - COGAIN 2009: Gaze Interaction For Those Who Want It Most, ISBN: 978-87-643-0475-

    Cosmology in a supersymmetric model with gauged BLB-L

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    We consider salient cosmological features of a supersymmetric model which is Left-Right symmetric and therefore possessing gauged BLB-L symmetry. The requirement of breaking parity and also obtaining charge preserving vacua introduces some unique features to this model (MSLRM), resulting in a preference for non-thermal Leptogenesis. Assuming that the model preserves TeV scale supersymmetry, we show that the vacuum structure generically possesses domain walls, which can serve two important purposes. They can signal a secondary inflation required to remove unwanted relics such as gravitino and moduli and also generate lepton asymmetry by a mechanism similar to electroweak baryogenesis. The requirement of disappearance of domain walls imposes constraints on the soft parameters of the theory, testable at the TeV scale. We also propose an alternative model with spontaneous parity violation (MSLR\rlap/P). Incorporating the same cosmological considerations in this case entails constraints on a different set of soft parameters.Comment: 18 pages. Minor changes in text, but conclusion remains same. Published in Phys. Rev.

    The Constitutionality of Solitary Confinement: Insights from Maslow’s Hierarchy of Needs

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    The article examines the Eighth Amendment and solitary confinement in the United States, in particular, the tenth circuit court decision in Silverstein v. Federal Bureau of Prisons, and possible solutions

    The Constitutionality of Solitary Confinement: Insights from Maslow’s Hierarchy of Needs

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    The article examines the Eighth Amendment and solitary confinement in the United States, in particular, the tenth circuit court decision in Silverstein v. Federal Bureau of Prisons, and possible solutions

    Analytic and constructive processes in the comprehension of text

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    This thesis explores the process of comprehension as a purposeful interaction between a reader and the information in a text. The review begins by discussing the difference between educational and psychological perspectives on comprehension. Approaches to the analysis of text structure are then described and models and theories of the representation of knowledge are evaluated. It is argued that these are limited in that they tend to focus either on the text or the reader: they either examine those procedures that are necessary for text analysis or the knowledge structures required for comprehension, storage and retrieval. Those that come nearest to examining the interaction between text and knowledge structures tend to be limited in terms of the texts they can deal with and they do not deal adequately with the predictive aspects of comprehension.Experiments are reported which look at the ongoing predictions made by readers, and how these are affected by factors such as text structure and ‘interestingness’. The experiments provided the opportunity for examining the potential of alternative methodologies (such as the content analysis of open-ended questions). It is felt that it is necessary to examine comprehension using methods which are direct but not intrusive. The studies reported demonstrate that it is possible to obtain reliable measures of a reader's predictions and that these are systematically affected by the structure and content of the text
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