105 research outputs found
A Stronger Stitching Algorithm for Fisheye Images based on Deblurring and Registration
Fisheye lens, which is suitable for panoramic imaging, has the prominent
advantage of a large field of view and low cost. However, the fisheye image has
a severe geometric distortion which may interfere with the stage of image
registration and stitching. Aiming to resolve this drawback, we devise a
stronger stitching algorithm for fisheye images by combining the traditional
image processing method with deep learning. In the stage of fisheye image
correction, we propose the Attention-based Nonlinear Activation Free Network
(ANAFNet) to deblur fisheye images corrected by Zhang calibration method.
Specifically, ANAFNet adopts the classical single-stage U-shaped architecture
based on convolutional neural networks with soft-attention technique and it can
restore a sharp image from a blurred image effectively. In the part of image
registration, we propose the ORB-FREAK-GMS (OFG), a comprehensive image
matching algorithm, to improve the accuracy of image registration. Experimental
results demonstrate that panoramic images of superior quality stitching by
fisheye images can be obtained through our method.Comment: 6 pages, 5 figure
Elastically-Constrained Meta-Learner for Federated Learning
Federated learning is an approach to collaboratively training machine
learning models for multiple parties that prohibit data sharing. One of the
challenges in federated learning is non-IID data between clients, as a single
model can not fit the data distribution for all clients. Meta-learning, such as
Per-FedAvg, is introduced to cope with the challenge. Meta-learning learns
shared initial parameters for all clients. Each client employs gradient descent
to adapt the initialization to local data distributions quickly to realize
model personalization. However, due to non-convex loss function and randomness
of sampling update, meta-learning approaches have unstable goals in local
adaptation for the same client. This fluctuation in different adaptation
directions hinders the convergence in meta-learning. To overcome this
challenge, we use the historical local adapted model to restrict the direction
of the inner loop and propose an elastic-constrained method. As a result, the
current round inner loop keeps historical goals and adapts to better solutions.
Experiments show our method boosts meta-learning convergence and improves
personalization without additional calculation and communication. Our method
achieved SOTA on all metrics in three public datasets.Comment: FL-IJCAI'2
CSPRD: A Financial Policy Retrieval Dataset for Chinese Stock Market
In recent years, great advances in pre-trained language models (PLMs) have
sparked considerable research focus and achieved promising performance on the
approach of dense passage retrieval, which aims at retrieving relative passages
from massive corpus with given questions. However, most of existing datasets
mainly benchmark the models with factoid queries of general commonsense, while
specialised fields such as finance and economics remain unexplored due to the
deficiency of large-scale and high-quality datasets with expert annotations. In
this work, we propose a new task, policy retrieval, by introducing the Chinese
Stock Policy Retrieval Dataset (CSPRD), which provides 700+ prospectus passages
labeled by experienced experts with relevant articles from 10k+ entries in our
collected Chinese policy corpus. Experiments on lexical, embedding and
fine-tuned bi-encoder models show the effectiveness of our proposed CSPRD yet
also suggests ample potential for improvement. Our best performing baseline
achieves 56.1% MRR@10, 28.5% NDCG@10, 37.5% Recall@10 and 80.6% Precision@10 on
dev set
Establishment of the Luoping Biota National Geopark in Yunnan, China
Geoparks in China have been a great success story, with 284 national geoparks and 41 of them accorded UNESCO international status, the highest number for any country in the world. We track the progress of one of the geoparks, Luoping Biota National Geopark in Yunnan Province, from initial plans after its discovery as a key site for the exceptional preservation of Middle Triassic marine fossils in 2007, to acceptance as a National Geopark in 2011. Geoparks combine great scientific importance with accessibility and attraction for tourists. The scientific importance of Luoping is in the fossils, thousands of specimens of marine invertebrates, fishes and reptiles, together with rare elements from land (e.g. insects, plants), representing an important phase in the Mesozoic Marine Revolution, when life was recovering from devastation at the end of the Permian, and 8 million years later, had developed stable ecosystems with a new structure, dominated by predatory fishes and reptiles. The touristic importance of the Luoping Biota Geopark has already been demonstrated by rapid development of facilities and high visitor numbers
A new millipede (Diplopoda, Helminthomorpha) from the Middle Triassic Luoping biota of Yunnan, Southwest China
AbstractA new helminthomorph millipede,Sinosoma luopingensenew genus new species, from the Triassic Luoping biota of China, has 39 body segments, metazonites with lateral swellings that bear a pair of posterolateral pits (?insertion pits for spine bases), and sternites that are unfused to the pleurotergites. This millipede shares a number of characters with nematophoran diplopods, but lacks the prominent dorsal suture characteristic of that order. Other “millipede” material from the biota is more problematic. Millipedes are a rare part of the Luoping biota, which is composed mainly of marine and near-shore organisms. Occurrences of fossil millipedes are exceedingly rare in Triassic rocks worldwide, comprising specimens from Europe, Asia, and Africa, and consisting of juliform millipedes and millipedes that are either nematophorans or forms very similar to nematophorans.</jats:p
Exceptional appendage and soft-tissue preservation in a Middle Triassic horseshoe crab from SW China
Abstract Horseshoe crabs are classic “living fossils”, supposedly slowly evolving, conservative taxa, with a long fossil record back to the Ordovician. The evolution of their exoskeleton is well documented by fossils, but appendage and soft-tissue preservation is extremely rare. Here we analyse details of appendage and soft-tissue preservation in Yunnanolimulus luopingensis, a Middle Triassic (ca. 244 million years old) horseshoe crab from Yunnan Province, SW China. The remarkable preservation of anatomical details including the chelicerae, five pairs of walking appendages, opisthosomal appendages with book gills, muscles, and fine setae permits comparison with extant horseshoe crabs. The close anatomical similarity between the Middle Triassic horseshoe crabs and their recent analogues documents anatomical conservatism for over 240 million years, suggesting persistence of lifestyle. The occurrence of Carcinoscorpius-type claspers on the first and second walking legs in male individuals of Y. luopingensis indicates that simple chelate claspers in males are plesiomorphic for horseshoe crabs, and the bulbous claspers in Tachypleus and Limulus are derived
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