Global weak sharp minima for convex (semi-)infinite optimization problems

AbstractWe mainly consider global weak sharp minima for convex infinite and semi-infinite optimization problems (CIP). In terms of the normal cone, subdifferential and directional derivative, we provide several characterizations for (CIP) to have global weak sharp minimum property

Exploring explicit coarse-grained structure in artificial neural networks

We propose to employ the hierarchical coarse-grained structure in the artificial neural networks explicitly to improve the interpretability without degrading performance. The idea has been applied in two situations. One is a neural network called TaylorNet, which aims to approximate the general mapping from input data to output result in terms of Taylor series directly, without resorting to any magic nonlinear activations. The other is a new setup for data distillation, which can perform multi-level abstraction of the input dataset and generate new data that possesses the relevant features of the original dataset and can be used as references for classification. In both cases, the coarse-grained structure plays an important role in simplifying the network and improving both the interpretability and efficiency. The validity has been demonstrated on MNIST and CIFAR-10 datasets. Further improvement and some open questions related are also discussed

Tentative evidence of spatially extended GeV emission from SS433/W50

We analyze 10 years of Fermi-LAT data towards the SS433/W50 region. With the latest source catalog and diffuse background models, the gamma-ray excess from SS433/W50 is detected with a significance of 6{\sigma} in the photon energy range of 500 MeV - 10 GeV. Our analysis indicates that an extended flat disk morphology is preferred over a point-source description, suggesting that the GeV emission region is much larger than that of the TeV emission detected by HAWC. The size of the GeV emission is instead consistent with the extent of the radio nebula W50, a supernova remnant being distorted by the jets, so we suggest that the GeV emission may originate from this supernova remnant. The spectral result of the GeV emission is also consistent with an supernova remnant origin. We also derive the GeV flux upper limits on the TeV emission region, which put moderate constrains on the leptonic models to explain the multiwavelength data.Comment: 7 pages, 4 figures, accepted for publication in A&

Bis(μ-biphenyl-2,2′-dicarboxyl­ato)bis­[aqua­(4,4′-dimethyl-2,2′-bipyridine-κ2 N,N′)copper(II)]

The mol­ecule of the title binuclear copper(II) complex, [Cu2(C14H8O4)2(C12H12N2)2(H2O)2], is bis­ected by a crystallographic twofold axis. Each CuII atom is coordinated in a distorted octa­hedral geometry by three O atoms from two biphen­yl-2,2′-dicarboxyl­ate anions, one aqua O atom and two N atoms of a 4,4′-dimethyl-2,2′-bipyridine ligand. Intramolecular O—H⋯O hydrogen bonds between the coordinated water molecules and the carboxylate O atoms are also present