316 research outputs found
ZerNet: Convolutional Neural Networks on Arbitrary Surfaces via Zernike Local Tangent Space Estimation
In this paper, we propose a novel formulation to extend CNNs to
two-dimensional (2D) manifolds using orthogonal basis functions, called Zernike
polynomials. In many areas, geometric features play a key role in understanding
scientific phenomena. Thus, an ability to codify geometric features into a
mathematical quantity can be critical. Recently, convolutional neural networks
(CNNs) have demonstrated the promising capability of extracting and codifying
features from visual information. However, the progress has been concentrated
in computer vision applications where there exists an inherent grid-like
structure. In contrast, many geometry processing problems are defined on curved
surfaces, and the generalization of CNNs is not quite trivial. The difficulties
are rooted in the lack of key ingredients such as the canonical grid-like
representation, the notion of consistent orientation, and a compatible local
topology across the domain. In this paper, we prove that the convolution of two
functions can be represented as a simple dot product between Zernike polynomial
coefficients; and the rotation of a convolution kernel is essentially a set of
2-by-2 rotation matrices applied to the coefficients. As such, the key
contribution of this work resides in a concise but rigorous mathematical
generalization of the CNN building blocks
A peculiar lens-shaped structure observed in the South China Sea
Lens-shaped structures within thermocline potentially play a significant role in subsurface transport of mass, heat, and salt in the global ocean. Whilst such structures have been documented in many oceanic regions, none has been observed in the China Seas. This study reports on observations of a lens-shaped structure within thermocline in the southwestern South China Sea in September 2007. This structure had a maximum thickness of approximately 60 m and a horizontal extent exceeding 220 km. This lens was peculiar in that its size is larger than most similar structures documented in the literature. The lens core was characterized by well-mixed water with higher temperature (~28.8 °C), lower salinity (~33.3) and lower potential vorticity (PV) compared to the surrounding waters. Based on an ocean reanalysis, possible generation mechanism of the lens is explored by examining the evolution of surface and subsurface thermohaline properties, and an analysis of vertical PV flux. The lens was likely generated by a mixture of the local mixed-layer water and the water from the coastal jet separation site
Complete mitochondrial genome sequences of Physogyra lichtensteini (Milne Edwards & Haime, 1851) and Plerogyra sinuosa (Dana, 1846) (Scleractinia, Plerogyridae): characterisation and phylogenetic analysis
In this study, the whole mitochondrial genomes of Physogyra lichtensteini and Plerogyra sinuosa have been sequenced for the first time. The length of their assembled mitogenome sequences were 17,286 bp and 17,586 bp, respectively, both including 13 protein-coding genes, two tRNAs, and two rRNAs. Their mitogenomes offered no distinct structure and their gene order were the same as other typical scleractinians. Based on 13 protein-coding genes, a maximum likelihood phylogenetic analysis showed that Physogyra lichtensteini and Plerogyra sinuosa are clustered in the family Plerogyridae, which belongs to the “Robust” clade. The 13 tandem mitogenome PCG sequences used in this research can provide important molecular information to clarify the evolutionary relationships amongst stony corals, especially at the family level. On the other hand, more advanced markers and more species need to be used in the future to confirm the evolutionary relationships of all the scleractinians
Using association rules mining to explore pattern of Chinese medicinal formulae (prescription) in treating and preventing breast cancer recurrence and metastasis.
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Towards a high-intensity muon source at CiADS
The proposal of a high-intensity muon source driven by the CiADS linac, which
has the potential to be one of the state-of-the-art facilities, is presented in
this paper. We briefly introduce the development progress of the
superconducting linac of CiADS. Then the consideration of challenges related to
the high-power muon production target is given and the liquid lithium jet muon
production target concept is proposed, for the first time. The exploration of
the optimal target geometry for surface muon production efficiency and the
investigation into the performance of liquid lithium jet target in muon rate
are given. Based on the comparison between the liquid lithium jet target and
the rotation graphite target, from perspectives of surface muon production
efficiency, heat processing ability and target geometry compactness, the
advantages of the new target concept are demonstrated and described
comprehensively. The technical challenges and the feasibility of the
free-surface liquid lithium target are discussed
The Anzhen Risk Scoring System for Acute Type A Aortic Dissection: A Prospective Observational Study Protocol
Introduction: Acute type A aortic dissection (ATAAD) is a catastrophic disease with fatal outcomes. Malperfusion syndrome (MPS) is a serious complication of ATAAD, with an incidence of 20–40%. Many studies have shown that MPS is the main risk factor for poor ATAAD prognosis. However, a risk scoring system for ATAAD based on MPS is lacking. Here, we designed a risk scoring system for ATAAD to assess mortality through quantitative assessment of relevant organ malperfusion and subsequently develop rational treatment strategies.Methods and analysis: This was a prospective observational study. Patients’ perioperative clinical data were collected to establish a database of ATAAD (N≥3000) and determine whether these patients had malperfusion complications. The Anzhen risk scoring system was established on the basis of organ malperfusion by using a random forest survival model and a logistics model. The better method was then chosen to establish a revised risk scoring system.Ethics and dissemination: This study received ethical approval from the Ethics Committees of Beijing Anzhen Hospital, Capital Medical University (KS2019034-1). Patient consent was waived because biological samples were not collected, and no patient rights were violated. Findings will be disseminated at scientific conferences and in peer-reviewed publications
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