595 research outputs found

    Recommendations for the representation of hierarchical objects in Europeana

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    The issue of handling hierarchical objects has been always an important topic for Europeana’s network of projects and Data Providers. The implementation of solutions in the Europeana portal has been delayed for a long time mainly due to the fact that complex objects required the development of new functionalities that could not be supported by the Europeana Semantic Elements (ESE) model. Indeed the simplicity and the flatness of this model prevented Data Providers from supplying complex objects

    Insecure SSL Remote Desktop Protocol Traffic: snooPDR Development

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    poster abstractAbstract: The goal of this project was to show how vulnerable SSL-secured Remote Desktop Protocol communication using RSA is. This project will develop a method to capture authentication packets of an RDP session and decrypt the SSL key used. A secondary goal is to develop a method to replay the authentication packets with the RDP server after the snooped session has ended. The motivation of this project is to demonstrate the insecurity of RSA-encrypted SSL encryption in Remote Desktop Protocol connections used by many network administrators. This project will build a Linux installation which can capture Remote Desktop Protocol packets and develop a method to decrypt the confidential communication between the client and the server. Database Security Techniques used in this project will include: access security in authentication to the operating system and encryption of data at rest because Linux hashes passwords in the users database of the operating system. This project will be exploiting access control to the RDP server. The secondary goal of this project will be to authorize an untrusted user to access confidential data assets. The expected result of this project is to successfully capture and monitor the packets associated with authentication to an RDP server and secondarily to be able to successfully masquerade as the previously authenticated user. Evaluations will include the ability to successfully capture 10 RDP sessions, decrypt them, and store the packet information into an SQL database. Results include the ability to insert packet data into a database, capture encrypted traffic and decrypt traffic if the private key is known

    Examining Factors Associated with the Use of Face Coverings during COVID-19: A Survey of Shoppers in Greater Grand Forks, Minnesota and North Dakota

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    Despite the availability of COVID-19 vaccines, the pandemic’s persistence and recent spikes in cases have heightened the need for the promotion of protective behaviors notably, the continued use of face coverings (or ‘masks’ in the common parlance for COVID-related face coverings). Effective messaging on mask use is essential to more fully resonate with individuals and their shared communities. Studies covering rural or mostly-urban regions in the U.S. are sparse. Accordingly, an interdisciplinary team of social work and public health researchers explored mask wearing behaviors in a small, urban metro community consisting of two cities spanning North Dakota and Minnesota that serves a mostly rural region. Chi-square tests for independence revealed nuanced gender and age-based differences in face covering usage. Significant factors in mask usage included satisfaction with available information and related public education efforts, and approval from people perceived to be important. Findings suggest the value of utilizing parasocial interactions to promote protective behaviors such as face covering use. This paper discusses additional implications

    Outside options: another reason to choose the first-price auction

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    Pre-print draft dated October 2005. Final version published by Elsevier; available online at http://www.sciencedirect.com/In this paper we study equilibrium and experimental bidding behaviour in first-price and second-price auctions with outside options. We find that bidders do respond to outside options and to variations of common knowledge about competitors’ outside options. However, overbidding in first-price auctions is significantly higher with outside options than without. First-price auctions yield more revenue than second-price auctions. This revenue-premium is significantly higher with outside options. In second-price auctions the introduction of outside options has only a small effect

    Strange Quark Matter and Compact Stars

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    Astrophysicists distinguish between three different types of compact stars. These are white dwarfs, neutron stars, and black holes. The former contain matter in one of the densest forms found in the Universe which, together with the unprecedented progress in observational astronomy, make such stars superb astrophysical laboratories for a broad range of most striking physical phenomena. These range from nuclear processes on the stellar surface to processes in electron degenerate matter at subnuclear densities to boson condensates and the existence of new states of baryonic matter--like color superconducting quark matter--at supernuclear densities. More than that, according to the strange matter hypothesis strange quark matter could be more stable than nuclear matter, in which case neutron stars should be largely composed of pure quark matter possibly enveloped in thin nuclear crusts. Another remarkable implication of the hypothesis is the possible existence of a new class of white dwarfs. This article aims at giving an overview of all these striking physical possibilities, with an emphasis on the astrophysical phenomenology of strange quark matter. Possible observational signatures associated with the theoretically proposed states of matter inside compact stars are discussed as well. They will provide most valuable information about the phase diagram of superdense nuclear matter at high baryon number density but low temperature, which is not accessible to relativistic heavy ion collision experiments.Comment: 58 figures, to appear in "Progress in Particle and Nuclear Physics"; References added for sections 1,2,3,5; Equation (116) corrected; Figs. 1 and 58 update

    Annihilation of structural defects in chalcogenide absorber films for high-efficiency solar cells

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    Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG geförderten) Allianz- bzw. Nationallizenz frei zugÀnglich.This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.In polycrystalline semiconductor absorbers for thin-film solar cells, structural defects may enhance electron-hole recombination and hence lower the resulting energy conversion efficiency. To be able to efficiently design and optimize fabrication processes that result in high-quality materials, knowledge of the nature of structural defects as well as their formation and annihilation during film growth is essential. Here we show that in co-evaporated Cu(In,Ga)Se-2 absorber films the density of defects is strongly influenced by the reaction path and substrate temperature during film growth. A combination of high-resolution electron microscopy, atomic force microscopy, scanning tunneling microscopy, and X-ray diffraction shows that Cu(In,Ga)Se-2 absorber films deposited at low temperature without a Cu-rich stage suffer from a high density of - partially electronically active - planar defects in the {112} planes. Real-time X-ray diffraction reveals that these faults are nearly completely annihilated during an intermediate Cu-rich process stage with [Cu]/([In] + [Ga]) > 1. Moreover, correlations between real-time diffraction and fluorescence analysis during Cu-Se deposition reveal that rapid defect annihilation starts shortly before the start of segregation of excess Cu-Se at the surface of the Cu(In,Ga)Se-2 film. The presented results hence provide direct insights into the dynamics of the film-quality-improving mechanism
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