54,509 research outputs found

    Novice Ideas: Handwriting Comparisons Conducted by an Untrained Individual

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    Forensic analysis of questioned documents includes chemical analyses of paper and ink as well as handwriting comparisons. Several elements affect handwriting analyses, including the presence of discriminatory factors that can individualize a handwriting sample and whether the handwriting has been disguised. Five handwriting samples were gathered from six individuals comprising of one reference, three natural unknowns, and one disguised sample per person. A novice conducted analyses on every collected sample and conducted comparisons of the reference sample to the unknown and disguised samples in an attempt to correctly source the unknown and disguised samples. The novice showed a high level of accuracy in correctly sourcing the natural sample but made erroneous conclusions when analyzing the disguised samples

    Lacking Regulated Policy for DNA Evidence

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    Despite its strong presence in criminal justice, DNA analysis is still a minimally regulated area. This minimal regulation devalues DNA evidence through the inconsistencies in these areas. The analysis methods of low template DNA lack a uniform method resulting in varying levels of reliability. Utilizing familial searches to assist in criminal investigations can potentially violate citizen rights. Such violations can also be found in the collection of DNA samples before an arrestee is tried or convicted. There are, however, regulations that could be applied universally to combat the problems that were discussed

    Persistent Homology of Filtered Covers

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    We prove an extension to the simplicial Nerve Lemma which establishes isomorphism of persistent homology groups, in the case where the covering spaces are filtered. While persistent homology is now widely used in topological data analysis, the usual Nerve Lemma does not provide isomorphism of persistent homology groups. Our argument involves some homological algebra: the key point being that although the maps produced in the standard proof of the Nerve Lemma do not commute as maps of chain complexes, the maps they induce on homology do.Comment: 12 pages, no figure

    Quantum photon emission from a moving mirror in the nonperturbative regime

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    We consider the coupling of the electromagnetic vacuum field with an oscillating perfectly-reflecting mirror in the nonrelativistic approximation. As a consequence of the frequency modulation associated to the motion of the mirror, low frequency photons are generated. We calculate the photon emission rate by following a nonperturbative approach, in which the coupling between the field sidebands is taken into account. We show that the usual perturbation theory fails to account correctly for the contribution of TM-polarized vacuum fluctuations that propagate along directions nearly parallel to the plane surface of the mirror. As a result of the modification of the field eigenfunctions, the resonance frequency for photon emission is shifted from its unperturbed value.Comment: 11 pages, 3 figures. To be published in Optics Communication

    On the Stability of Black Holes at the LHC

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    The eventual production of mini black holes by proton-proton collisions at the LHC is predicted by theories with large extra dimensions resolvable at the Tev scale of energies. It is expected that these black holes evaporate shortly after its production as a consequence of the Hawking radiation. We show that for theories based on the ADS/CFT correspondence, the produced black holes may have an unstable horizon, which grows proportionally to the square of the distance to the collision point.Comment: 3 page
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