23,259 research outputs found

    Adversarial Deep Structured Nets for Mass Segmentation from Mammograms

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    Mass segmentation provides effective morphological features which are important for mass diagnosis. In this work, we propose a novel end-to-end network for mammographic mass segmentation which employs a fully convolutional network (FCN) to model a potential function, followed by a CRF to perform structured learning. Because the mass distribution varies greatly with pixel position, the FCN is combined with a position priori. Further, we employ adversarial training to eliminate over-fitting due to the small sizes of mammogram datasets. Multi-scale FCN is employed to improve the segmentation performance. Experimental results on two public datasets, INbreast and DDSM-BCRP, demonstrate that our end-to-end network achieves better performance than state-of-the-art approaches. \footnote{https://github.com/wentaozhu/adversarial-deep-structural-networks.git}Comment: Accepted by ISBI2018. arXiv admin note: substantial text overlap with arXiv:1612.0597

    Association schemes from the action of PGL(2,q)PGL(2,q) fixing a nonsingular conic in PG(2,q)

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    The group PGL(2,q)PGL(2,q) has an embedding into PGL(3,q)PGL(3,q) such that it acts as the group fixing a nonsingular conic in PG(2,q)PG(2,q). This action affords a coherent configuration R(q)R(q) on the set L(q)L(q) of non-tangent lines of the conic. We show that the relations can be described by using the cross-ratio. Our results imply that the restrictions R+(q)R_{+}(q) and Rβˆ’(q)R_{-}(q) to the sets L+(q)L_{+}(q) of secant lines and to the set Lβˆ’(q)L_{-}(q) of exterior lines, respectively, are both association schemes; moreover, we show that the elliptic scheme Rβˆ’(q)R_{-}(q) is pseudocyclic. We further show that the coherent configuration R(q2)R(q^2) with qq even allow certain fusions. These provide a 4-class fusion of the hyperbolic scheme R+(q2)R_{+}(q^2), and 3-class fusions and 2-class fusions (strongly regular graphs) of both schemes R+(q2)R_{+}(q^2) and $R_{-}(q^2). The fusion results for the hyperbolic case are known, but our approach here as well as our results in the elliptic case are new.Comment: 33 page

    Determination of a Type of Permutation Binomials over Finite Fields

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    Let f=a\x+\x^{3q-2}\in\Bbb F_{q^2}[\x], where a∈Fq2βˆ—a\in\Bbb F_{q^2}^*. We prove that ff is a permutation polynomial of Fq2\Bbb F_{q^2} if and only if one of the following occurs: (i) q=2eq=2^e, ee odd, and aq+13a^{\frac{q+1}3} is a primitive 33rd root of unity. (ii) (q,a)(q,a) belongs to a finite set which is determined in the paper

    Development and Verification of a Flight Stack for a High-Altitude Glider in Ada/SPARK 2014

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    SPARK 2014 is a modern programming language and a new state-of-the-art tool set for development and verification of high-integrity software. In this paper, we explore the capabilities and limitations of its latest version in the context of building a flight stack for a high-altitude unmanned glider. Towards that, we deliberately applied static analysis early and continuously during implementation, to give verification the possibility to steer the software design. In this process we have identified several limitations and pitfalls of software design and verification in SPARK, for which we give workarounds and protective actions to avoid them. Finally, we give design recommendations that have proven effective for verification, and summarize our experiences with this new language
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