487 research outputs found

    Upgrade of the SPS extraction Kickers for LHC and CNGS Operation

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    The extraction kickers of the Super Proton Synchrotron (SPS) need to be upgraded to meet the Large Hadron Collider (LHC) and CERN Neutrino to Grand Sasso (CNGS) requirements. Commissioning of the extraction towards one of the LHC rings and the CNGS facility under construction is foreseen for 2003. The ferrites of the kicker magnets will be heated significantly by the circulating beam and need to be cooled to stay below the Curie temperature. A cost-effective solution to this problem is presented consisting of AlN water cooled plates on the top and bottom of the ferrites. Model predictions are compared with preliminary laboratory measurements and machine data from the SPS. Commissioning of the extraction towards the other LHC ring is planned for 2006. Beyond the heat load issues, this latter extraction needs a larger horizontal "kick" and thus a higher magnetic field and larger horizontal beam aperture. The rise and fall time requirements of these kickers are less strict, therefore a new system with lower impedance permitting a larger magnetic field can be used

    Tracheal cryopreservation: caspase-3 immunoreactivity in tracheal epithelium and in mixed glands

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    Cryopreservation has an immunomodulating effect on tracheal tissue as a result of class II antigen depletion due to epithelium exfoliation. However, not all epithelium is detached. We evaluated the role of apoptosis in the remaining epithelium of 30 cryopreserved tracheal grafts. Caspase-3 immunoreactivity of tracheal epithelium was studied in canine tracheal segments cryopreserved with F12K medium, with or without subsequent storage in liquid nitrogen at -196°C for 15 days. Loss of structural integrity of tracheal mixed glands was observed in all cryopreserved tracheal segments. Caspase-3 immunoreactivity in tracheal mucosa and in mixed glands was significantly decreased, in contrast to the control group and to cryopreserved tracheal segments in which it remained high, due to the effect of storage in liquid nitrogen (P < 0.05, ANOVA and Tukey test). We conclude that apoptosis can be triggered in epithelial cells during tracheal graft harvesting even prior to cryopreservation, and although the epithelial caspase-3 immunoreactivity is reduced in tracheal cryopreservation, this could be explained by increased cell death. Apoptosis cannot be stopped during tracheal cryopreservation

    Modelling the Interaction Levels in HCI Using an Intelligent Hybrid System with Interactive Agents: A Case Study of an Interactive Museum Exhibition Module in Mexico

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    Technology has become a necessity in our everyday lives and essential for completing activities we typically take for granted; technologies can assist us by completing set tasks or achieving desired goals with optimal affect and in the most efficient way, thereby improving our interactive experiences. This paper presents research that explores the representation of user interaction levels using an intelligent hybrid system approach with agents. We evaluate interaction levels of Human-Computer Interaction (HCI) with the aim of enhancing user experiences. We consider the description of interaction levels using an intelligent hybrid system to provide a decision-making system to an agent that evaluates interaction levels when using interactive modules of a museum exhibition. The agents represent a high-level abstraction of the system, where communication takes place between the user, the exhibition and the environment. In this paper, we provide a means to measure the interaction levels and natural behaviour of users, based on museum user-exhibition interaction. We consider that, by analysing user interaction in a museum, we can help to design better ways to interact with exhibition modules according to the properties and behaviour of the users. An interaction-evaluator agent is proposed to achieve the most suitable representation of the interaction levels with the aim of improving user interactions to offer the most appropriate directions, services, content and information, thereby improving the quality of interaction experienced between the user-agent and exhibition-agent

    Towards Team Formation Using Belbin Role Types and a Social Networks Analysis Approach

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    Problems relating to team formation is common across many industrial sectors, including education, sport and general business. For Team Leaders, team member selection can be a critical challenge due to the complexity in creating a well-balanced productive unit. It is beyond manual implementation to build near optimal teams as pools of employees grow. One of the essential skills of individuals is the ability to work in a team, and it takes on greater importance in engineering workgroups, where each member must know how to collaborate with their colleagues. In this paper, we use the combination of the Belbin roles and the social network analysis approach to find the possible members of a team. We present a case study based on an undergraduate course in computer engineering, we apply the Belbin test to each student, and each student expresses his preferences to work with his classmates. With this data, similarity patterns were searched within a social network using network analysis algorithms. We compare the results of the network analysis with the groups formed by a teacher. Finally, we discuss the advantages and disadvantages of project teams, from the proposed approach
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