84,830 research outputs found
d+id' Chiral Superconductivity in Bilayer Silicene
We investigate the structure and physical properties of the undoped bilayer
silicene through first-principles calculations and find the system is
intrinsically metallic with sizable pocket Fermi surfaces. When realistic
electron-electron interaction turns on, the system is identified as a chiral
d+id' topological superconductor mediated by the strong spin fluctuation on the
border of the antiferromagnetic spin density wave order. Moreover, the tunable
Fermi pocket area via strain makes it possible to adjust the spin density wave
critical interaction strength near the real one and enables a high
superconducting critical temperature
Managing the noisy glaucomatous test data by self organising maps
One of the main difficulties in obtaining reliable data from patients in glaucomatous tests is the measurement noise caused by the learning effect, inattention, failure of fixation, fatigue, etc. Using Kohonen's self-organising feature maps, we have developed a computational method to distinguish between the noise and true measurement. This method has been shown to provide a satisfactory way of locating and rejecting noise in the test data, an improvement over conventional statistical method
From Node-Line Semimetals to Large Gap QSH States in New Family of Pentagonal Group-IVA Chalcogenide
Two-dimensional (2D) topological insulators (TIs) have attracted tremendous
research interest from both theoretical and experimental fields in recent
years. However, it is much less investigated in realizing node line (NL)
semimetals in 2D materials.Combining first-principles calculations and model, we find that NL phases emerge in p-CS and p-SiS, as well as
other pentagonal IVX films, i.e. p-IVX (IV= C, Si, Ge, Sn, Pb; X=S, Se,
Te) in the absence of spin-orbital coupling (SOC). The NLs in p-IVX form
symbolic Fermi loops centered around the point and are protected by
mirror reflection symmetry. As the atomic number is downward shifted, the NL
semimetals are driven into 2D TIs with the large bulk gap up to 0.715 eV
induced by the remarkable SOC effect.The nontrivial bulk gap can be tunable
under external biaxial and uniaxial strain. Moreover, we also propose a quantum
well by sandwiching p-PbTe crystal between two NaI sheets, in which
p-PbTe still keeps its nontrivial topology with a sizable band gap (
0.5 eV). These findings provide a new 2D materials family for future design and
fabrication of NL semimetals and TIs.Comment: 6 pages, 5 figures,2 table
AI for public health: Self-screening for eye diseases
A software-based visual-field testing (perimetry) system is described which incorporates several AI components, including machine learning, an intelligent user interface and pattern discovery. This system has been successfully used for self-screening in several different public environment
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
- …
