6,040 research outputs found

    Ambient Isotopic Meshing of Implicit Algebraic Surface with Singularities

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    A complete method is proposed to compute a certified, or ambient isotopic, meshing for an implicit algebraic surface with singularities. By certified, we mean a meshing with correct topology and any given geometric precision. We propose a symbolic-numeric method to compute a certified meshing for the surface inside a box containing singularities and use a modified Plantinga-Vegter marching cube method to compute a certified meshing for the surface inside a box without singularities. Nontrivial examples are given to show the effectiveness of the algorithm. To our knowledge, this is the first method to compute a certified meshing for surfaces with singularities.Comment: 34 pages, 17 Postscript figure

    Bipartite Bell Inequality and Maximal Violation

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    We present new bell inequalities for arbitrary dimensional bipartite quantum systems. The maximal violation of the inequalities is computed. The Bell inequality is capable of detecting quantum entanglement of both pure and mixed quantum states more effectively.Comment: 6 pages,no figure

    Computing the kk-coverage of a wireless network

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    Coverage is one of the main quality of service of a wirelessnetwork. kk-coverage, that is to be covered simultaneously by kknetwork nodes, is synonym of reliability and numerous applicationssuch as multiple site MIMO features, or handovers. We introduce here anew algorithm for computing the kk-coverage of a wirelessnetwork. Our method is based on the observation that kk-coverage canbe interpreted as kk layers of 11-coverage, or simply coverage. Weuse simplicial homology to compute the network's topology and areduction algorithm to indentify the layers of 11-coverage. Weprovide figures and simulation results to illustrate our algorithm.Comment: Valuetools 2019, Mar 2019, Palma de Mallorca, Spain. 2019. arXiv admin note: text overlap with arXiv:1802.0844

    Avalanche noise characteristics of thin GaAs structures with distributed carrier generation

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    It is known that both pure electron and pure hole injection into thin GaAs multiplication regions gives rise to avalanche multiplication with noise lower than predicted by the local noise model. In this paper, it is shown that the noise from multiplication initiated by carriers generated throughout a 0.1 μm avalanche region is also lower than predicted by the local model but higher than that obtained with pure injection of either carrier type. This behavior is due to the effects of nonlocal ionization brought about by the dead space; the minimum distance a carrier has to travel in the electric field to initiate an ionization even

    Improved hole-injection contact for top-emitting polymeric diodes

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    In this letter, an efficient hole-injection contact was achieved for the top-emitting polymeric light-emitting diodes (PLEDs). The anode has a structure of metal/molybdenum oxide/poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate) (PEDOT:PSS). It has been found that hole injection was significantly improved by inserting a thin layer of MoO3 between aluminum and PEDOT:PSS. An ultraviolet photoelectron spectroscopy (UPS) was used to investigate the change of work function, and photovoltaic measurement confirmed that the improved hole injection is due to the reduction of barrier height, resulted from the addition of transition metal oxide. PEDOT:PSS layer was found necessary in anode structure to further enhance the hole injection and electroluminance efficiency. A peak power efficiency of 11.42lm∕W was achieved at current density of 1.2mA/cm2 for the white emission top-emitting PLEDs

    Single image example-based super-resolution using cross-scale patch matching and Markov random field modelling

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    Example-based super-resolution has become increasingly popular over the last few years for its ability to overcome the limitations of classical multi-frame approach. In this paper we present a new example-based method that uses the input low-resolution image itself as a search space for high-resolution patches by exploiting self-similarity across different resolution scales. Found examples are combined in a high-resolution image by the means of Markov Random Field modelling that forces their global agreement. Additionally, we apply back-projection and steering kernel regression as post-processing techniques. In this way, we are able to produce sharp and artefact-free results that are comparable or better than standard interpolation and state-of-the-art super-resolution techniques

    A simple circuit realization of the tent map

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    We present a very simple electronic implementation of the tent map, one of the best-known discrete dynamical systems. This is achieved by using integrated circuits and passive elements only. The experimental behavior of the tent map electronic circuit is compared with its numerical simulation counterpart. We find that the electronic circuit presents fixed points, periodicity, period doubling, chaos and intermittency that match with high accuracy the corresponding theoretical valuesComment: 6 pages, 6 figures, 10 references, published versio

    JAK2V617F promotes replication fork stalling with disease-restricted impairment of the intra-S checkpoint response

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    Cancers result from the accumulation of genetic lesions, but the cellular consequences of driver mutations remain unclear, especially during the earliest stages of malignancy. The V617F mutation in the JAK2 non-receptor tyrosine kinase (JAK2V617F) is present as an early somatic event in most patients with myeloproliferative neoplasms (MPNs), and the study of these chronic myeloid malignancies provides an experimentally tractable approach to understanding early tumorigenesis. Introduction of exogenous JAK2V617F impairs replication fork progression and is associated with activation of the intra-S checkpoint, with both effects mediated by phosphatidylinositide 3-kinase (PI3K) signaling. Analysis of clonally derived JAK2V617F-positive erythroblasts from MPN patients also demonstrated impaired replication fork progression accompanied by increased levels of replication protein A (RPA)-containing foci. However, the associated intra-S checkpoint response was impaired in erythroblasts from polycythemia vera (PV) patients, but not in those from essential thrombocythemia (ET) patients. Moreover, inhibition of p53 in PV erythroblasts resulted in more gamma-H2Ax (γ-H2Ax)–marked double-stranded breaks compared with in like-treated ET erythroblasts, suggesting the defective intra-S checkpoint function seen in PV increases DNA damage in the context of attenuated p53 signaling. These results demonstrate oncogene-induced impairment of replication fork progression in primary cells from MPN patients, reveal unexpected disease-restricted differences in activation of the intra-S checkpoint, and have potential implications for the clonal evolution of malignancies

    The Extended Coupled Cluster Treatment of Correlations in Quantum Magnets

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    The spin-half XXZ model on the linear chain and the square lattice are examined with the extended coupled cluster method (ECCM) of quantum many-body theory. We are able to describe both the Ising-Heisenberg phase and the XY-Heisenberg phase, starting from known wave functions in the Ising limit and at the phase transition point between the XY-Heisenberg and ferromagnetic phases, respectively, and by systematically incorporating correlations on top of them. The ECCM yields good numerical results via a diagrammatic approach, which makes the numerical implementation of higher-order truncation schemes feasible. In particular, the best non-extrapolated coupled cluster result for the sublattice magnetization is obtained, which indicates the employment of an improved wave function. Furthermore, the ECCM finds the expected qualitatively different behaviours of the linear chain and the square lattice cases.Comment: 22 pages, 3 tables, and 15 figure

    Fast Algorithm for Partial Covers in Words

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    A factor uu of a word ww is a cover of ww if every position in ww lies within some occurrence of uu in ww. A word ww covered by uu thus generalizes the idea of a repetition, that is, a word composed of exact concatenations of uu. In this article we introduce a new notion of α\alpha-partial cover, which can be viewed as a relaxed variant of cover, that is, a factor covering at least α\alpha positions in ww. We develop a data structure of O(n)O(n) size (where n=wn=|w|) that can be constructed in O(nlogn)O(n\log n) time which we apply to compute all shortest α\alpha-partial covers for a given α\alpha. We also employ it for an O(nlogn)O(n\log n)-time algorithm computing a shortest α\alpha-partial cover for each α=1,2,,n\alpha=1,2,\ldots,n
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