130 research outputs found
Study on the Coniferous Characters of Pinus yunnanensis and Its Clustering Analysis
Pine is a relatively easy genus for intermediate hybridization. It has been widely believed that there should be anatural hybrid population in the distribution of Pinus massoniona Lamb. and Pinus hangshuanensis Hsia, that is, theexcessive type of external form between Pinus massoniana and Pinus taiwanensis exist. This paper mainly discussesthe traits and clustering analysis of coniferous lozeng in Huangshan scenic area. This study will provide a theoreticalbasis for the classification of long and outstanding Huangshan Song and so on. At the same time, it will providereference for the phenomenon of gene seepage between the two species
UNet++: A Nested U-Net Architecture for Medical Image Segmentation
In this paper, we present UNet++, a new, more powerful architecture for
medical image segmentation. Our architecture is essentially a deeply-supervised
encoder-decoder network where the encoder and decoder sub-networks are
connected through a series of nested, dense skip pathways. The re-designed skip
pathways aim at reducing the semantic gap between the feature maps of the
encoder and decoder sub-networks. We argue that the optimizer would deal with
an easier learning task when the feature maps from the decoder and encoder
networks are semantically similar. We have evaluated UNet++ in comparison with
U-Net and wide U-Net architectures across multiple medical image segmentation
tasks: nodule segmentation in the low-dose CT scans of chest, nuclei
segmentation in the microscopy images, liver segmentation in abdominal CT
scans, and polyp segmentation in colonoscopy videos. Our experiments
demonstrate that UNet++ with deep supervision achieves an average IoU gain of
3.9 and 3.4 points over U-Net and wide U-Net, respectively.Comment: 8 pages, 3 figures, 3 tables, accepted by 4th Deep Learning in
Medical Image Analysis (DLMIA) Worksho
Synthetic Data as Validation
This study leverages synthetic data as a validation set to reduce overfitting
and ease the selection of the best model in AI development. While synthetic
data have been used for augmenting the training set, we find that synthetic
data can also significantly diversify the validation set, offering marked
advantages in domains like healthcare, where data are typically limited,
sensitive, and from out-domain sources (i.e., hospitals). In this study, we
illustrate the effectiveness of synthetic data for early cancer detection in
computed tomography (CT) volumes, where synthetic tumors are generated and
superimposed onto healthy organs, thereby creating an extensive dataset for
rigorous validation. Using synthetic data as validation can improve AI
robustness in both in-domain and out-domain test sets. Furthermore, we
establish a new continual learning framework that continuously trains AI models
on a stream of out-domain data with synthetic tumors. The AI model trained and
validated in dynamically expanding synthetic data can consistently outperform
models trained and validated exclusively on real-world data. Specifically, the
DSC score for liver tumor segmentation improves from 26.7% (95% CI:
22.6%-30.9%) to 34.5% (30.8%-38.2%) when evaluated on an in-domain dataset and
from 31.1% (26.0%-36.2%) to 35.4% (32.1%-38.7%) on an out-domain dataset.
Importantly, the performance gain is particularly significant in identifying
very tiny liver tumors (radius < 5mm) in CT volumes, with Sensitivity improving
from 33.1% to 55.4% on an in-domain dataset and 33.9% to 52.3% on an out-domain
dataset, justifying the efficacy in early detection of cancer. The application
of synthetic data, from both training and validation perspectives, underlines a
promising avenue to enhance AI robustness when dealing with data from varying
domains
Label-Assemble: Leveraging Multiple Datasets with Partial Labels
The success of deep learning relies heavily on large and diverse datasets
with extensive labels, but we often only have access to several small datasets
associated with partial labels. In this paper, we start a new initiative,
"Label-Assemble", that aims to unleash the full potential of partially labeled
data from an assembly of public datasets. Specifically, we introduce a new
dynamic adapter to encode different visual tasks, which addresses the
challenges of incomparable, heterogeneous, or even conflicting labeling
protocols. We also employ pseudo-labeling and consistency constraints to
harness data with missing labels and to mitigate the domain gap across
datasets. From rigorous evaluations on three natural imaging and six medical
imaging tasks, we discover that learning from "negative examples" facilitates
both classification and segmentation of classes of interest. This sheds new
light on the computer-aided diagnosis of rare diseases and emerging pandemics,
wherein "positive examples" are hard to collect, yet "negative examples" are
relatively easier to assemble. Apart from exceeding prior arts in the ChestXray
benchmark, our model is particularly strong in identifying diseases of minority
classes, yielding over 3-point improvement on average. Remarkably, when using
existing partial labels, our model performance is on-par with that using full
labels, eliminating the need for an additional 40% of annotation costs. Code
will be made available at https://github.com/MrGiovanni/LabelAssemble
The Progenitor of Supernova 2004dj in a Star Cluster
The progenitor of type II-plateau supernova (SN) 2004dj is identified with a
supergiant in a compact star cluster known as "Sandage Star 96" (S96) in the
nearby spiral galaxy NGC 2403, which was fortuitously imaged as part of the
Beijing-Arizona-Taiwan-Connecticut (BATC) Multicolor Sky Survey from Feb 1995
to Dec 2003 prior to SN 2004dj. The superior photometry of BATC images for S96,
taken with 14 intermediate-band filters covering 3000-10000\AA, unambiguously
establishes the star cluster nature of S96 with an age of Myr, a
reddening of mag and a total mass of M. The compact star cluster nature of S96 is also consistent
with the lack of light variations in the past decade. The SN progenitor is
estimated to have a main-sequence mass of 12M. The comparison
of our intermediate-band data of S96 with the post-outburst photometry obtained
as the SN has significantly dimmed, may hopefully conclusively establish the
nature of the progenitor.Comment: 4 pages; 3 figures. To accept for Publications in ApJ Letters, but
slightly longer in this perprin
- …