75 research outputs found

    Ubic: Bridging the gap between digital cryptography and the physical world

    Full text link
    Advances in computing technology increasingly blur the boundary between the digital domain and the physical world. Although the research community has developed a large number of cryptographic primitives and has demonstrated their usability in all-digital communication, many of them have not yet made their way into the real world due to usability aspects. We aim to make another step towards a tighter integration of digital cryptography into real world interactions. We describe Ubic, a framework that allows users to bridge the gap between digital cryptography and the physical world. Ubic relies on head-mounted displays, like Google Glass, resource-friendly computer vision techniques as well as mathematically sound cryptographic primitives to provide users with better security and privacy guarantees. The framework covers key cryptographic primitives, such as secure identification, document verification using a novel secure physical document format, as well as content hiding. To make a contribution of practical value, we focused on making Ubic as simple, easily deployable, and user friendly as possible.Comment: In ESORICS 2014, volume 8712 of Lecture Notes in Computer Science, pp. 56-75, Wroclaw, Poland, September 7-11, 2014. Springer, Berlin, German

    El cambio global

    Get PDF
    En este artículo se analiza un subconjunto de los fenómenos conocidos como Cambio Global y en los que el autor ha realizado algunas investigaciones. Desde que se originó, hace unos cuatro mil seiscientos millones de años (4,6 Ga) hasta el presente, la Tierra ha sido un planeta cambiante. El cambio es producido por enormes fuerzas naturales que elevan montañas, quiebran la corteza terrestre, hacen emerger volcanes que cambian el paisaje geológico, crean islas y archipiélagos y otros fenómenos de similar magnitud que, a veces, cambian el clima. La acción humana es irrelevante ante los cambios producidos por estas fuerzas naturales. Sin embargo, en pequeña escala, acumulativa, la humanidad produce otros cambios que pueden controlarse, evitarse o modificarse. Estos cambios se operan principalmente en la atmósfera y tienen efectos sobre uno o más subsistemas de la Tierra.Universidad Nacional de La Plat

    El cambio global

    Get PDF
    En este artículo se analiza un subconjunto de los fenómenos conocidos como Cambio Global y en los que el autor ha realizado algunas investigaciones. Desde que se originó, hace unos cuatro mil seiscientos millones de años (4,6 Ga) hasta el presente, la Tierra ha sido un planeta cambiante. El cambio es producido por enormes fuerzas naturales que elevan montañas, quiebran la corteza terrestre, hacen emerger volcanes que cambian el paisaje geológico, crean islas y archipiélagos y otros fenómenos de similar magnitud que, a veces, cambian el clima. La acción humana es irrelevante ante los cambios producidos por estas fuerzas naturales. Sin embargo, en pequeña escala, acumulativa, la humanidad produce otros cambios que pueden controlarse, evitarse o modificarse. Estos cambios se operan principalmente en la atmósfera y tienen efectos sobre uno o más subsistemas de la Tierra.Universidad Nacional de La Plat

    El cambio global

    Get PDF
    En este artículo se analiza un subconjunto de los fenómenos conocidos como Cambio Global y en los que el autor ha realizado algunas investigaciones. Desde que se originó, hace unos cuatro mil seiscientos millones de años (4,6 Ga) hasta el presente, la Tierra ha sido un planeta cambiante. El cambio es producido por enormes fuerzas naturales que elevan montañas, quiebran la corteza terrestre, hacen emerger volcanes que cambian el paisaje geológico, crean islas y archipiélagos y otros fenómenos de similar magnitud que, a veces, cambian el clima. La acción humana es irrelevante ante los cambios producidos por estas fuerzas naturales. Sin embargo, en pequeña escala, acumulativa, la humanidad produce otros cambios que pueden controlarse, evitarse o modificarse. Estos cambios se operan principalmente en la atmósfera y tienen efectos sobre uno o más subsistemas de la Tierra.Universidad Nacional de La Plat

    Loop groups and noncommutative geometry

    Get PDF
    We describe the representation theory of loop groups in terms of K-theory and noncommutative geometry. This is done by constructing suitable spectral triples associated with the level l projective unitary positive-energy representations of any given loop group LGLG. The construction is based on certain supersymmetric conformal field theory models associated with LG in the setting of conformal nets. We then generalize the construction to many other rational chiral conformal field theory models including coset models and the moonshine conformal net.Comment: Revised versio

    The radial arrangement of the human chromosome 7 in the lymphocyte cell nucleus is associated with chromosomal band gene density

    Get PDF
    This is the author's accepted manuscript. The final published article is available from the link below. Copyright @ Springer-Verlag 2008.In the nuclei of human lymphocytes, chromosome territories are distributed according to the average gene density of each chromosome. However, chromosomes are very heterogeneous in size and base composition, and can contain both very gene-dense and very gene-poor regions. Thus, a precise analysis of chromosome organisation in the nuclei should consider also the distribution of DNA belonging to the chromosomal bands in each chromosome. To improve our understanding of the chromatin organisation, we localised chromosome 7 DNA regions, endowed with different gene densities, in the nuclei of human lymphocytes. Our results showed that this chromosome in cell nuclei is arranged radially with the gene-dense/GC-richest regions exposed towards the nuclear interior and the gene-poorest/GC-poorest ones located at the nuclear periphery. Moreover, we found that chromatin fibres from the 7p22.3 and the 7q22.1 bands are not confined to the territory of the bulk of this chromosome, protruding towards the inner part of the nucleus. Overall, our work demonstrates the radial arrangement of the territory of chromosome 7 in the lymphocyte nucleus and confirms that human genes occupy specific radial positions, presumably to enhance intra- and inter-chromosomal interaction among loci displaying a similar expression pattern, and/or similar replication timing

    Bohrification of operator algebras and quantum logic

    Get PDF
    Following Birkhoff and von Neumann, quantum logic has traditionally been based on the lattice of closed linear subspaces of some Hilbert space, or, more generally, on the lattice of projections in a von Neumann algebra A. Unfortunately, the logical interpretation of these lattices is impaired by their nondistributivity and by various other problems. We show that a possible resolution of these difficulties, suggested by the ideas of Bohr, emerges if instead of single projections one considers elementary propositions to be families of projections indexed by a partially ordered set C(A) of appropriate commutative subalgebras of A. In fact, to achieve both maximal generality and ease of use within topos theory, we assume that A is a so-called Rickart C*-algebra and that C(A) consists of all unital commutative Rickart C*-subalgebras of A. Such families of projections form a Heyting algebra in a natural way, so that the associated propositional logic is intuitionistic: distributivity is recovered at the expense of the law of the excluded middle. Subsequently, generalizing an earlier computation for n-by-n matrices, we prove that the Heyting algebra thus associated to A arises as a basis for the internal Gelfand spectrum (in the sense of Banaschewski-Mulvey) of the "Bohrification" of A, which is a commutative Rickart C*-algebra in the topos of functors from C(A) to the category of sets. We explain the relationship of this construction to partial Boolean algebras and Bruns-Lakser completions. Finally, we establish a connection between probability measure on the lattice of projections on a Hilbert space H and probability valuations on the internal Gelfand spectrum of A for A = B(H).Comment: 31 page

    Pinturas murales de la casa de Ariadna (Pompeya, Italia): un estudio multidisciplinar de su estado actual enfocado a una futura restauración y conservación preventiva

    Get PDF
    [EN] This paper deals with the development of a multidisciplinary study on the current state of conservation of Ariadne’s house (Pompeii, Italy), a domus of great archaeological value. The aim of this study is to undertake the preventive conservation actions required and increase the knowledge about its conservation and to generate discussions and points of view for a future restoration. Environmental studies, electromagnetic radiation measurements, study of materials and a photographical study were carried out. Those studies revealed that the rooftops covering the analyzed rooms resulting in adverse weather conditions causing grave damage to the conservation of the wall paintings. Thus, between 2009-2010 the rooftops were changed and new environmental studies were conducted. Studies of materials showed that the paintings match in execution and composition with those reported by other authors. The salts from modern mortars from previous restorations were affecting frescoes, also it is described a thin grayish surface layer from environmental contaminants.[ES] Este trabajo desarrolla un estudio multidisciplinar sobre el actual estado de conservación de la casa de Ariadna (Pompeya, Italia), domus de gran valor arqueológico. El objetivo es aumentar el conocimiento del estado actual de conservación de la casa para la discusión de una futura restauración. Para ello se realizaron estudios ambientales, mediciones de radiación electromagnética, estudio de materiales y un estudio fotográfico. Los estudios revelaron que los tejados que cubrían las salas analizadas estaban originando unas condiciones climatológicas adversas que se traducían en un grave daño para la conservación de las pinturas murales. Entre 2009-2010 se cambiaron las cubiertas y los estudios ambientales fueron repetidos. Los estudios de materiales demostraron que las pinturas coinciden en ejecución y composición con las señaladas por otros autores. Las sales procedentes de morteros modernos de anteriores restauraciones afectaban a las pinturas, también se describe una fina capa superficial de tonalidad grisácea procedente de contaminantes ambientales.This work was partially supported by the Spanish "Ministerio de Ciencia e Innovacion" under projects HAR2010-21944-C02-01 and HAR2010-21944-C02-02. The authors are grateful to J. Minguez for his English grammar corrections.Pérez García, MDC.; García Diego, FJ.; Merello Giménez, P.; D'antoni, P.; Fernández Navajas, A.; Ribera I Lacomba, A.; Ferrazza, L.... (2013). Ariadne's house (Pompeii, Italy) wall paintings: A multidisciplinary study of its present state focused on a future restoration and preventive conservation. Materiales de Construcción. 63(311):449-467. https://doi.org/10.3989/mc.2012.00812S4494676331
    • …
    corecore