49 research outputs found

    Functional renormalisation group in a finite volume

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    We study a Ď•4\phi^4-theory at finite temperature in a finite volume. Quantum, thermal and volume fluctuations are treated with the functional renormalisation group. Specifically, we focus on the interplay of temperature and length scales driving the system. We find that thermodynamical observables at finite volume such as the pressure approach the infinite volume limit similarly to that of the vanishing temperature limit. We also advance the functional renormalisation group method at finite volume. In particular, we identify requirements for suitable regulators that admit the exponential thermal and finite volume decay properties.Comment: 20 pages, 20 figure

    Device-independent randomness extraction for arbitrarily weak min-entropy source

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    Expansion and amplification of weak randomness plays a crucial role in many security protocols. Using quantum devices, such procedure is possible even without trusting the devices used, by utilizing correlations between outcomes of parts of the devices. We show here how to extract random bits with an arbitrarily low bias from a single arbitrarily weak min-entropy source in a device independent setting. To do this we use Mermin devices that exhibit super-classical correlations. Number of devices used scales polynomially in the length of the random sequence nn. Our protocol is robust, it can tolerate devices that malfunction with a probability dropping polynomially in nn at the cost of a minor increase of the number of devices used.Comment: 5 pages + 3 pages supplementary materia

    Dilaton Quantum Gravity

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    We propose a simple fixed point scenario in the renormalization flow of a scalar dilaton coupled to gravity. This would render gravity non-perturbatively renormalizable and thus constitute a viable theory of quantum gravity. On the fixed point dilatation symmetry is exact and the quantum effective action takes a very simple form. Realistic gravity with a nonzero Planck mass is obtained through a nonzero expectation value for the scalar field, constituting a spontaneous scale symmetry breaking. Furthermore, relevant couplings for the flow away from the fixed point can be associated with a 'dilatation anomaly' that is responsible for dynamical dark energy. For the proposed fixed point and flow away from it the cosmological 'constant' vanishes for asymptotic time.Comment: 6 pages, 2 figures, version to appear in PL

    Towards an Internationalization of the Information Systems Curriculum

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    Globalization has changed the requirements to professionals and students in all branches and sectors significantly in the past decade. However in the domain of Information Systems, these changes have not yet found their way into current study programs and curricula. We identify and validate core internationalization competences and their relation to IS specific competences based on an initial set of competence categories. This is the basis for designing learning services of the future. The presented study aims at validating both and identifying additional categories and competences. In this paper, we present the first results of this study focusing on the internationalization and knowledge management competences. The results can be used for different purposes exploring the human perspective on information systems development

    A novel approach towards skill-based search and services of Open Educational Resources

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    Ha, K.-H., Niemann, K., Schwertel, U., Holtkamp, P., Pirkkalainen, H., Börner, D. et al (2011). A novel approach towards skill-based search and services of Open Educational Resources. In E. Garcia-Barriocanal, A. Öztürk, & M. C. Okur (Eds.), Metadata and Semantics Research: 5th International Conference MTSR 2011 (pp. 312-323), Izmir, Turkey, October 12-14, 2011. Springer.Open educational resources (OER) have a high potential to address the growing need for training materials in management education and training. Today, a high number of OER in management are already available in a large number of repositories. However, users face barriers as they have to search repository by repository with different interfaces to retrieve the appropriate learning content. In addition, the use of search criteria related to skills, such as learning objectives and skill-levels is not generally supported. The European co-funded project OpenScout addresses these barriers by intelligently connecting leading European OER repositories and providing federated, skillbased search and retrieval web services. On top of this content federation the project supports users with easy-to-apply tools that will accelerate the (re-) use of open content

    D1.1 Analysis Report on Federated Infrastructure and Application Profile

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    Kawese, R., Fisichella, M., Deng, F., Friedrich, M., Niemann, K., Börner, D., Holtkamp, P., Hun-Ha, K., Maxwell, K., Parodi, E., Pawlowski, J., Pirkkalainen, H., Rodrigo, C., & Schwertel, U. (2010). D1.1 Analysis Report on Federated Infrastructure and Application Profile. OpenScout project deliverable.The present deliverable aims to report on functionalities of the first step of the described process. In other words, the deliverable describes how the consortium will gather the learning objects metadata, centralize the access to existing learning resources and form a suitable application profile which will contribute to a proper and suitable modeling, retrieval and presentation of the required information (regarding the learning objects) to the interested users. The described approach is the foundation for the federated, skill-based search and learning object retrieval. The deliverable focuses on reporting the analysis of the available repositories and the best infrastructure that can support OpenScout’s initiative. The deliverable explains the motivations behind the chosen infrastructure based on the study of available information and previous research and literature.The work on this publication has been sponsored by the OpenScout (Skill based scouting of open user-generated and community-improved content for management education and training) Targeted Project that is funded by the European Commission’s 7th Framework Programme. Contract ECP-2008-EDU-42801

    Manifesto for a Standard on Meaningful Representations of Knowledge in Social Knowledge Management Environments

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    Knowledge Management (KM) is a social activity. More and more organizations use social software as a tool to bridge the gap between technology- and human-oriented KM. In order to create interoperable, transferable solutions, it is necessary to utilize standards. In this paper, we analyze which standards can be applied and which gaps currently exist. We present the concept of knowledge bundles, capturing information on knowledge objects, activities and people as a prerequisite for social-focused KM. Based on our concept and examples, we derive the strong need for standardization in this domain. As a manifesto this paper tries to stimulate discussion and to enable a broad initiative working towards a common standard for the next generation of knowledge management systems. Our manifesto provides with eight recommendations how the KM community should act to address future challenges

    Cold atoms in space: community workshop summary and proposed road-map

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    We summarise the discussions at a virtual Community Workshop on Cold Atoms in Space concerning the status of cold atom technologies, the prospective scientific and societal opportunities offered by their deployment in space, and the developments needed before cold atoms could be operated in space. The cold atom technologies discussed include atomic clocks, quantum gravimeters and accelerometers, and atom interferometers. Prospective applications include metrology, geodesy and measurement of terrestrial mass change due to, e.g., climate change, and fundamental science experiments such as tests of the equivalence principle, searches for dark matter, measurements of gravitational waves and tests of quantum mechanics. We review the current status of cold atom technologies and outline the requirements for their space qualification, including the development paths and the corresponding technical milestones, and identifying possible pathfinder missions to pave the way for missions to exploit the full potential of cold atoms in space. Finally, we present a first draft of a possible road-map for achieving these goals, that we propose for discussion by the interested cold atom, Earth Observation, fundamental physics and other prospective scientific user communities, together with the European Space Agency (ESA) and national space and research funding agencies.publishedVersio
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