Practical Block-wise Neural Network Architecture Generation

Convolutional neural networks have gained a remarkable success in computer vision. However, most usable network architectures are hand-crafted and usually require expertise and elaborate design. In this paper, we provide a block-wise network generation pipeline called BlockQNN which automatically builds high-performance networks using the Q-Learning paradigm with epsilon-greedy exploration strategy. The optimal network block is constructed by the learning agent which is trained sequentially to choose component layers. We stack the block to construct the whole auto-generated network. To accelerate the generation process, we also propose a distributed asynchronous framework and an early stop strategy. The block-wise generation brings unique advantages: (1) it performs competitive results in comparison to the hand-crafted state-of-the-art networks on image classification, additionally, the best network generated by BlockQNN achieves 3.54% top-1 error rate on CIFAR-10 which beats all existing auto-generate networks. (2) in the meanwhile, it offers tremendous reduction of the search space in designing networks which only spends 3 days with 32 GPUs, and (3) moreover, it has strong generalizability that the network built on CIFAR also performs well on a larger-scale ImageNet dataset.Comment: Accepted to CVPR 201

Triply heavy tetraquark states with the QQQˉqˉQQ\bar{Q}\bar{q} configuration

In the framework of the color-magnetic interaction, we systematically investigate the mass splittings of the $QQ\bar{Q}\bar{q}$ tetraquark states and estimated their rough masses in this work. These systems include the explicitly exotic states $cc\bar{b}\bar{q}$ and $bb\bar{c}\bar{q}$ and the hidden exotic states $cc\bar{c}\bar{q}$, $cb\bar{b}\bar{q}$, $bc\bar{c}\bar{q}$, and $bb\bar{b}\bar{q}$. If a state around the estimated mass region could be observed, its nature as a genuine tetraquark is favored. The strong decay patterns shown here will be helpful to the experimental search for these exotic states.Comment: 14 pages, 3 figures and 9 tables. Accepted by Eur. Phys. J.

Poly[tris­[μ2-2-(pyrazol-1-yl)pyrazine]hexa-μ1,3-thio­cyanato-tricadmium(II)]

The asymmetric unit of the title crystal structure, [Cd3(NCS)6(C7H6N4)2]n, contains two independent CdII ions, one of which is located on a crystallographic inversion center. Each independent CdII ion is in a slightly distorted octa­hedral coordination environment, but the disortion from ideally octa­hedral is greater in the environment of the CdII ion on a general position. Both thio­cyanate ligands act as bridges connecting independent CdII ions, and the 2-(pyrazol-1-yl)pyrazine ligands chelate one CdII ion in a bidentate mode while the remaining N atom of the pyrazine ring coordinates to a symmetry-related CdII ion, forming a two-dimensional structure parallel to (211)