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A words-of-interest model of sketch representation for image retrieval
In this paper we propose a method for sketch-based image retrieval. Sketch is a magical medium which is capable of conveying semantic messages for user. It’s in accordance with user’s cognitive psychology to retrieve images with sketch. In order to narrow down the semantic gap between the user and the images in database, we preprocess all the images into sketches by the coherent line drawing algorithm. During the process of sketches extraction, saliency maps are used to filter out the redundant background information, while preserve the important semantic information. We use a variant of Words-of-Interest model to retrieve relevant images for the user according to the query. Words-of-Interest (WoI) model is based on Bag-ofvisual Words (BoW) model, which has been proven successfully for information retrieval. Bag-of-Words ignores the spatial relationships among visual words, which are important for sketch representation. Our method takes advantage of the spatial information of the query to select words of interest. Experimental results demonstrate that our sketch-based retrieval method achieves a good tradeoff between retrieval accuracy and semantic representation of users’ query
NLO QCD + NLO EW corrections to productions with leptonic decays at the LHC
Precision tests of the Standard Model (SM) require not only accurate
experiments, but also precise and reliable theoretical predictions. Triple
vector boson production provides a unique opportunity to investigate the
quartic gauge couplings and check the validity of the gauge principle in the
SM. Since the tree-level predictions alone are inadequate to meet this demand,
the next-to-leading order (NLO) calculation becomes compulsory. In this paper,
we calculate the NLO QCD + NLO electroweak (EW) corrections to the
productions with subsequent leptonic decays at the LHC by
adopting an improved narrow width approximation which takes into account the
off-shell contributions and spin correlations from the - and -boson
leptonic decays. The NLO QCD+EW corrected integrated cross sections for the
productions and some kinematic distributions of final products are
provided. The results show that both the NLO QCD and NLO EW corrections are
significant. In the jet-veto event selection scheme with , the NLO QCD+EW relative corrections to the integrated cross section
are and , while the genuine NLO EW relative corrections are
and , for the and productions, respectively.
We also investigate the theoretical dependence of the integrated cross section
on the factorization/renormalization scale, and find that the scale uncertainty
is underestimated at the LO due to the fact that the strong coupling
is not involved in the LO matrix elements.Comment: 19 pages, 8 figure
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