698 research outputs found
Contextual Attention for Hand Detection in the Wild
We present Hand-CNN, a novel convolutional network architecture for detecting
hand masks and predicting hand orientations in unconstrained images. Hand-CNN
extends MaskRCNN with a novel attention mechanism to incorporate contextual
cues in the detection process. This attention mechanism can be implemented as
an efficient network module that captures non-local dependencies between
features. This network module can be inserted at different stages of an object
detection network, and the entire detector can be trained end-to-end.
We also introduce a large-scale annotated hand dataset containing hands in
unconstrained images for training and evaluation. We show that Hand-CNN
outperforms existing methods on several datasets, including our hand detection
benchmark and the publicly available PASCAL VOC human layout challenge. We also
conduct ablation studies on hand detection to show the effectiveness of the
proposed contextual attention module.Comment: 9 pages, 9 figure
Contextual Attention for Hand Detection in the Wild
We present Hand-CNN, a novel convolutional network architecture for detecting hand masks and predicting hand orientations in unconstrained images. Hand-CNN extends MaskRCNN with a novel attention mechanism to incorporate contextual cues in the detection process. This attention mechanism can be implemented as an efficient network module that captures non-local dependencies between features. This network module can be inserted at different stages of an object detection network, and the entire detector can be trained end-to-end. We also introduce large-scale annotated hand datasets containing hands in unconstrained images for training and evaluation. We show that Hand-CNN outperforms existing methods on the newly collected datasets and the publicly available PASCAL VOC human layout dataset. Data and code: https://www3.cs.stonybrook.edu/~cvl/projects/hand_det_attention
A super-Eddington wind scenario for the progenitors of type Ia supernovae: binary population synthesis calculations
The super-Eddington wind scenario has been proposed as an alternative way for
producing type Ia supernovae (SNe Ia). The super-Eddington wind can naturally
prevent the carbon--oxygen white dwarfs (CO WDs) with high mass-accretion rates
from becoming red-giant-like stars. Furthermore, it works in low-metallicity
environments, which may explain SNe Ia observed at high redshifts. In this
article, we systematically investigated the most prominent single-degenerate
WD+MS channel based on the super-Eddington wind scenario. We combined the
Eggleton stellar evolution code with a rapid binary population synthesis (BPS)
approach to predict SN Ia birthrates for the WD+MS channel by adopting the
super-Eddington wind scenario and detailed mass-accumulation efficiencies of
H-shell flashes on the WDs. Our BPS calculations found that the estimated SN Ia
birthrates for the WD+MS channel are ~0.009-0.315*10^{-3}{yr}^{-1} if we adopt
the Eddington accretion rate as the critical accretion rate, which are much
lower than that of the observations (<10% of the observed SN Ia birthrates).
This indicates that the WD+MS channel only contributes a small proportion of
all SNe Ia. The birthrates in this simulation are lower than previous studies,
the main reason of which is that new mass-accumulation efficiencies of H-shell
flashes are adopted. We also found that the critical mass-accretion rate has a
significant influence on the birthrates of SNe Ia. Meanwhile, the results of
our BPS calculations are sensitive to the values of the common-envelope
ejection efficiency.Comment: 14 pages, 9 figures, 1 table, accepted for publication in Astronomy
and Astrophysic
The Effectiveness of Combined Drug Delivery Systems
Treatment of tumors with nanoparticles and combined drugs tend to turn effective as it can sustain for a longer time in the recipient’s body and also improve the impact. The conjugates that have proven to have high cytotoxicity are suggested in this report. Pegylation is an advanced drug delivery system that maximizes the immunity of the patient and helps in the correct targeting of the affected cells.
Keywords: Tumors, Nanoparticles, Drug targetin
Forecast of lacustrine shale lithofacies types in continental rift basins based on machine learning: A case study from Dongying Sag, Jiyang Depression, Bohai Bay Basin, China
Lacustrine shale in continental rift basins is complex and features a variety of mineralogical compositions and microstructures. The lithofacies type of shale, mainly determined by mineralogical composition and microstructure, is the most critical factor controlling the quality of shale oil reservoirs. Conventional geophysical methods cannot accurately forecast lacustrine shale lithofacies types, thus restricting the progress of shale oil exploration and development. Considering the lacustrine shale in the upper Es4 member of the Dongying Sag in the Jiyang Depression, Bohai Bay Basin, China, as the research object, the lithofacies type was forecast based on two machine learning methods: support vector machine (SVM) and extreme gradient boosting (XGBoost). To improve the forecast accuracy, we applied the following approaches: first, using core and thin section analyses of consecutively cored wells, the lithofacies were finely reclassified into 22 types according to mineralogical composition and microstructure, and the vertical change of lithofacies types was obtained. Second, in addition to commonly used well logging data, paleoenvironment parameter data (Rb/Sr ratio, paleoclimate parameter; Sr %, paleosalinity parameter; Ti %, paleoprovenance parameter; Fe/Mn ratio, paleo-water depth parameter; P/Ti ratio, paleoproductivity parameter) were applied to the forecast. Third, two sample extraction modes, namely, curve shape-to-points and point-to-point, were used in the machine learning process. Finally, the lithofacies type forecast was carried out under six different conditions. In the condition of selecting the curved shape-to-point sample extraction mode and inputting both well logging and paleoenvironment parameter data, the SVM method achieved the highest average forecast accuracy for all lithofacies types, reaching 68%, as well as the highest average forecast accuracy for favorable lithofacies types at 98%. The forecast accuracy for all lithofacies types improved by 7%–28% by using both well logging and paleoenvironment parameter data rather than using one or the other, and was 7%–8% higher by using the curve shape-to-point sample extraction mode compared to the point-to-point sample extraction mode. In addition, the learning sample quantity and data value overlap of different lithofacies types affected the forecast accuracy. The results of our study confirm that machine learning is an effective solution to forecast lacustrine shale lithofacies. When adopting machine learning methods, increasing the learning sample quantity (>45 groups), selecting the curve shape-to-point sample extraction mode, and using both well logging and paleoenvironment parameter data are effective ways to improve the forecast accuracy of lacustrine shale lithofacies types. The method and results of this study provide guidance to accurately forecast the lacustrine shale lithofacies types in new shale oil wells and will promote the harvest of lacustrine shale oil globally
Multi-Component Drug Delivery of Paclitaxel
Co-delivery systems have been proved to be of much benefit to the anti-cancer drug field. In order to make these drugs successful, nano-particles usage has been promoted. The mini-review has brought forward some of the most prominent co-delivery developments in the field, especially with paclitaxel. The discussion here is never meant to be comprehensive, but to give some new trends and highlights within this area
Multiple-Level Power Allocation Strategy for Secondary Users in Cognitive Radio Networks
In this paper, we propose a multiple-level power allocation strategy for the
secondary user (SU) in cognitive radio (CR) networks. Different from the
conventional strategies, where SU either stays silent or transmit with a
constant/binary power depending on the busy/idle status of the primary user
(PU), the proposed strategy allows SU to choose different power levels
according to a carefully designed function of the receiving energy. The way of
the power level selection is optimized to maximize the achievable rate of SU
under the constraints of average transmit power at SU and average interference
power at PU. Simulation results demonstrate that the proposed strategy can
significantly improve the performance of SU compared to the conventional
strategies.Comment: 12 page
Long-tail Augmented Graph Contrastive Learning for Recommendation
Graph Convolutional Networks (GCNs) has demonstrated promising results for
recommender systems, as they can effectively leverage high-order relationship.
However, these methods usually encounter data sparsity issue in real-world
scenarios. To address this issue, GCN-based recommendation methods employ
contrastive learning to introduce self-supervised signals. Despite their
effectiveness, these methods lack consideration of the significant degree
disparity between head and tail nodes. This can lead to non-uniform
representation distribution, which is a crucial factor for the performance of
contrastive learning methods. To tackle the above issue, we propose a novel
Long-tail Augmented Graph Contrastive Learning (LAGCL) method for
recommendation. Specifically, we introduce a learnable long-tail augmentation
approach to enhance tail nodes by supplementing predicted neighbor information,
and generate contrastive views based on the resulting augmented graph. To make
the data augmentation schema learnable, we design an auto drop module to
generate pseudo-tail nodes from head nodes and a knowledge transfer module to
reconstruct the head nodes from pseudo-tail nodes. Additionally, we employ
generative adversarial networks to ensure that the distribution of the
generated tail/head nodes matches that of the original tail/head nodes.
Extensive experiments conducted on three benchmark datasets demonstrate the
significant improvement in performance of our model over the state-of-the-arts.
Further analyses demonstrate the uniformity of learned representations and the
superiority of LAGCL on long-tail performance. Code is publicly available at
https://github.com/im0qianqian/LAGCLComment: 17 pages, 6 figures, accepted by ECML/PKDD 2023 (European Conference
on Machine Learning and Principles and Practice of Knowledge Discovery in
Databases
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