2,522 research outputs found

    Superpixels: An Evaluation of the State-of-the-Art

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    Superpixels group perceptually similar pixels to create visually meaningful entities while heavily reducing the number of primitives for subsequent processing steps. As of these properties, superpixel algorithms have received much attention since their naming in 2003. By today, publicly available superpixel algorithms have turned into standard tools in low-level vision. As such, and due to their quick adoption in a wide range of applications, appropriate benchmarks are crucial for algorithm selection and comparison. Until now, the rapidly growing number of algorithms as well as varying experimental setups hindered the development of a unifying benchmark. We present a comprehensive evaluation of 28 state-of-the-art superpixel algorithms utilizing a benchmark focussing on fair comparison and designed to provide new insights relevant for applications. To this end, we explicitly discuss parameter optimization and the importance of strictly enforcing connectivity. Furthermore, by extending well-known metrics, we are able to summarize algorithm performance independent of the number of generated superpixels, thereby overcoming a major limitation of available benchmarks. Furthermore, we discuss runtime, robustness against noise, blur and affine transformations, implementation details as well as aspects of visual quality. Finally, we present an overall ranking of superpixel algorithms which redefines the state-of-the-art and enables researchers to easily select appropriate algorithms and the corresponding implementations which themselves are made publicly available as part of our benchmark at davidstutz.de/projects/superpixel-benchmark/

    The Interleukin-12 Family of Cytokines and Receptor Signaling in Graft-versus-Host Disease

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    Allogeneic hematopoietic stem cell transplantation (allo-HCT) is an effective means by which to treat a wide variety of diseases resulting from dysfunctional hematopoiesis due to a potent anti-tumor response known as the graft-versus-tumor (GVT) effect after chemotherapy and/or irradiation. The necessity of donor T cells to mediate GVT is offset by the consequential development of graft-versus-host disease (GVHD); a leading cause of mortality among allo- HCT recipients. The IL-12 family of cytokines signals through Janus Kinase 2 (JAK2) and is comprised of IL-12, IL-23, IL-27, IL-35 and IL-39. IL-12 (p35+p40) and IL-23 (p19+p40) have well documented proinflammatory functions responsible for Th1 differentiation and Th17 stabilization, respectively, and play critical roles in GVHD development. As such, we found that targeting p40 resulted in reduced GVHD. IL-12R and IL-23R also share a Ī²-chain, IL-12RĪ²1. While IL-23R is widely implicated in autoimmunity and GVHD, the role of IL-12RĪ²1 remains much less defined. We found that donor splenocytes deficient for IL-12RĪ²1 or IL-23R had an impaired ability to induce chronic GVHD (cGVHD). We also found a pathogenic role for IL-23R on donor T cells in acute GVHD (aGVHD); strikingly, a similar effect was not seen for IL-12RĪ²1. Our studies then focused on determining how pharmacologically targeting IL-12/23p40 can be efficacious in reducing GVHD severity in experimental and clinical settings, yet also to explain why IL-12RĪ²1 may be dispensable in aGVHD. The newest member of the IL-12 family, IL-39, is composed of IL-23p19 and EBI3. Given the cognate receptor for IL-39 includes IL-23R and gp130, we hypothesized that IL-39 may play a role in aGVHD. We detected significantly higher IL-39 in serum of mice with aGVHD compared to recipients of bone marrow alone (BMA) and cGVHD, providing a potential explanation for how IL-23R signaling could bypass IL-12Ī²1. We also evaluated how JAK2 impacted GVHD. We found that T cell deficiency of JAK2 or neutralization via pacritinib significantly reduced mortality from GVHD. In summary, targeting IL-12 family signaling is an effective strategy to reduce GVHD. Further, future studies should focus on whether targeting IL-23/IL-39p19 is as effective as targeting IL-12/IL-23p40 in the clinic due to IL-39

    Higgs-Yukawa model on the lattice

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    We present results from two projects on lattice calculations for the Higgs-Yukawa model. First we report progress on the search of first-order thermal phase transitions in the presence of a dimension-six operator, with the choices of bare couplings that lead to viable phenomenological predictions. In this project the simulations are performed using overlap fermions to implement the required chiral symmetry. Secondly, our study for applying finite-size scaling techniques near the Gaussian fixed point of the Higgs-Yukawa model is presented. We discuss the analytical formulae for the Higgs Yukawa model and show results for a first numerical study in the pure O(4)O(4) scalar sector of the theory.Comment: 8 pages, 4 figures; Contribution to the proceedings of the 35th International Symposium on Lattice Field Theory, 18 - 24 June 2017, Granada, Spai

    A lattice study of a chirally invariant Higgs-Yukawa model including a higher dimensional Ī¦6\Phi^6-term

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    We discuss the non-thermal phase structure of a chirally invariant Higgs-Yukawa model on the lattice in the presence of a higher dimensional Ī¦6\Phi^6-term. For the exploration of the phase diagram we use analytical, lattice perturbative calculations of the constraint effectice potential as well as numerical simulations. We also present first results of the effects of the Ī¦6\Phi^6-term on the lower Higgs boson mass bounds

    Towards a Unified Quark-Hadron Matter Equation of State for Applications in Astrophysics and Heavy-Ion Collisions

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    We outline an approach to a unified equation of state for quark-hadron matter on the basis of a Ī¦āˆ’\Phi-derivable approach to the generalized Beth-Uhlenbeck equation of state for a cluster decomposition of thermodynamic quantities like the density. To this end we summarize the cluster virial expansion for nuclear matter and demonstrate the equivalence of the Green's function approach and the Ī¦āˆ’\Phi-derivable formulation. For an example, the formation and dissociation of deuterons in nuclear matter is discussed. We formulate the cluster Ī¦āˆ’\Phi-derivable approach to quark-hadron matter which allows to take into account the specifics of chiral symmetry restoration and deconfinement in triggering the Mott-dissociation of hadrons. This approach unifies the description of a strongly coupled quark-gluon plasma with that of a medium-modified hadron resonance gas description which are contained as limiting cases. The developed formalism shall replace the common two-phase approach to the description of the deconfinement and chiral phase transition that requires a phase transition construction between separately developed equations of state for hadronic and quark matter phases. Applications to the phenomenology of heavy-ion collisions and astrophysics are outlined.Comment: 35 pages, 3 figures, Special Issue "Compact Stars in the QCD Phase Diagram

    Measuring Infringement of Intellectual Property Rights

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    Ā© Crown Copyright 2014. You may re-use this information (excluding logos) free of charge in any format or medium, under the terms of the Open Government Licence. To view this licence, visit http://www.nationalarchives.gov. uk/doc/open-government-licence/ Where we have identified any third party copyright information you will need to obtain permission from the copyright holders concernedThe review is wide-ranging in scope and overall our findings evidence a lack of appreciation among those producing research for the high-level principles of measurement and assessment of scale. To date, the approaches adopted by industry seem more designed for internal consumption and are usually contingent on particular technologies and/or sector perspectives. Typically, there is a lack of transparency in the methodologies and data used to form the basis of claims, making much of this an unreliable basis for policy formulation. The research approaches we found are characterised by a number of features that can be summarised as a preference for reactive approaches that look to establish snapshots of an important issue at the time of investigation. Most studies are ad hoc in nature and on the whole we found a lack of sustained longitudinal approaches that would develop the appreciation of change. Typically the studies are designed to address specific hypotheses that might serve to support the position of the particular commissioning body. To help bring some structure to this area, we propose a framework for the assessment of the volume of infringement in each different area. The underlying aim is to draw out a common approach wherever possible in each area, rather than being drawn initially to the differences in each field. We advocate on-going survey tracking of the attitudes, perceptions and, where practical, behaviours of both perpetrators and claimants in IP infringement. Clearly, the nature of perpetrators, claimants and enforcement differs within each IPR but in our view the assessment for each IPR should include all of these elements. It is important to clarify that the key element of the survey structure is the adoption of a survey sampling methodology and smaller volumes of representative participation. Once selection is given the appropriate priority, a traditional offline survey will have a part to play, but as the opportunity arises, new technological methodologies, particularly for the voluntary monitoring of online behaviour, can add additional detail to the overall assessment of the scale of activity. This framework can be applied within each of the IP right sectors: copyright, trademarks,patents, and design rights. It may well be that the costs involved with this common approach could be mitigated by a syndicated approach to the survey elements. Indeed, a syndicated approach has a number of advantages in addition to cost. It could be designed to reduce any tendency either to hide inappropriate/illegal activity or alternatively exaggerate its volume to fit with the theme of the survey. It also has the scope to allow for monthly assessments of attitudes rather than being vulnerable to unmeasured seasonal impacts

    Phase structure and Higgs boson mass in a Higgs-Yukawa model with a dimension-6 operator

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    We investigate the impact of a Ī»6Ļ†6\lambda_6 \varphi^6 term included in a chirally invariant lattice Higgs-Yukawa model. Such a term could emerge from BSM physics at some larger energy scale. We map out the phase structure of the Higgs-Yukawa model with positive Ī»6\lambda_6 and negative quartic self coupling of the scalar fields. To this end, we evaluate the constraint effective potential in lattice perturbation theory and also determine the magnetization of the model via numerical simulations which allow us to reach also non-perturbative values of the couplings. As a result, we find a complex phase structure with first and second order phase transitions identified through the magnetization. Further we analyze the effect of such a Ļ†6\varphi^6 term on the lower Higgs boson mass bound to see, whether the standard model lower mass bound can be altered.Comment: proceedings for The 32nd International Symposium on Lattice Field Theor

    Off-Road Vehicle Recreation in the West: Implications of a Wyoming Analysis

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    Community/Rural/Urban Development, Resource /Energy Economics and Policy,
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