634 research outputs found
Hop-Reservation Multiple Access with Variable Slots
AbstractHop-reservation multiple access control protocols in Ad Hoc networks are widely researched for its virtue in anti-jamming. Several typical such protocols are introduced and compared. Based on the analysis about their performance on anti-jamming and ability to serve upper protocols, a hop-reservation multiple access protocol with variable slot (HMAVS) is proposed. By the adaptation of variable length slots, the hop speed of control channel can be supported to the largest extent while diverse applications can be served without additional cost. Simulation results demonstrate the preference of HMAVS to other existing protocols
Threshold for the Outbreak of Cascading Failures in Degree-degree Uncorrelated Networks
In complex networks, the failure of one or very few nodes may cause cascading
failures. When this dynamical process stops in steady state, the size of the
giant component formed by remaining un-failed nodes can be used to measure the
severity of cascading failures, which is critically important for estimating
the robustness of networks. In this paper, we provide a cascade of overload
failure model with local load sharing mechanism, and then explore the threshold
of node capacity when the large-scale cascading failures happen and un-failed
nodes in steady state cannot connect to each other to form a large connected
sub-network. We get the theoretical derivation of this threshold in
degree-degree uncorrelated networks, and validate the effectiveness of this
method in simulation. This threshold provide us a guidance to improve the
network robustness under the premise of limited capacity resource when creating
a network and assigning load. Therefore, this threshold is useful and important
to analyze the robustness of networks.Comment: 11 pages, 4 figure
Hierarchical Disentanglement-Alignment Network for Robust SAR Vehicle Recognition
Vehicle recognition is a fundamental problem in SAR image interpretation.
However, robustly recognizing vehicle targets is a challenging task in SAR due
to the large intraclass variations and small interclass variations.
Additionally, the lack of large datasets further complicates the task. Inspired
by the analysis of target signature variations and deep learning
explainability, this paper proposes a novel domain alignment framework named
the Hierarchical Disentanglement-Alignment Network (HDANet) to achieve
robustness under various operating conditions. Concisely, HDANet integrates
feature disentanglement and alignment into a unified framework with three
modules: domain data generation, multitask-assisted mask disentanglement, and
domain alignment of target features. The first module generates diverse data
for alignment, and three simple but effective data augmentation methods are
designed to simulate target signature variations. The second module
disentangles the target features from background clutter using the
multitask-assisted mask to prevent clutter from interfering with subsequent
alignment. The third module employs a contrastive loss for domain alignment to
extract robust target features from generated diverse data and disentangled
features. Lastly, the proposed method demonstrates impressive robustness across
nine operating conditions in the MSTAR dataset, and extensive qualitative and
quantitative analyses validate the effectiveness of our framework
Discovering and Explaining the Non-Causality of Deep Learning in SAR ATR
In recent years, deep learning has been widely used in SAR ATR and achieved
excellent performance on the MSTAR dataset. However, due to constrained imaging
conditions, MSTAR has data biases such as background correlation, i.e.,
background clutter properties have a spurious correlation with target classes.
Deep learning can overfit clutter to reduce training errors. Therefore, the
degree of overfitting for clutter reflects the non-causality of deep learning
in SAR ATR. Existing methods only qualitatively analyze this phenomenon. In
this paper, we quantify the contributions of different regions to target
recognition based on the Shapley value. The Shapley value of clutter measures
the degree of overfitting. Moreover, we explain how data bias and model bias
contribute to non-causality. Concisely, data bias leads to comparable
signal-to-clutter ratios and clutter textures in training and test sets. And
various model structures have different degrees of overfitting for these
biases. The experimental results of various models under standard operating
conditions on the MSTAR dataset support our conclusions. Our code is available
at https://github.com/waterdisappear/Data-Bias-in-MSTAR
Water-saving and pollution-reducing effects of different irri-gation modes in paddy fields: A case study in Pinghu, Zhejiang province
Objective To study the water-saving and pollution reduction effects of rice under different irrigation modes, and to explore the water-saving irrigation mode suitable for the plain river network area. Methods Three modes of conventional irrigation, thin dew irrigation and suitable rain irrigation were set up in Pinghu irrigation experimental station in Zhejiang Province. The irrigation amount, TN, TP, , NO-N and COD in drainage and leakage water samples were measured. Result Compared with conventional irrigation and thin dew irrigation, the irrigation amount of suitable rain irrigation was reduced by 67.4% and 43.4%, respectively, and the water-saving effect was the best. Compared with conventional irrigation and thin dew irrigation, rain-appropriate irrigation has the least drainage. TN emissions,  emissions, COD emissions and TP and  emissions are reduced by 86.9% and 90.7%, 96.7% and 98.3%, 61.5% and 62.5%, respectively. Conclusion Under the condition of this study, the water-saving and pollution reduction effect of rain irrigation is better
CROLoss: Towards a Customizable Loss for Retrieval Models in Recommender Systems
In large-scale recommender systems, retrieving top N relevant candidates
accurately with resource constrain is crucial. To evaluate the performance of
such retrieval models, Recall@N, the frequency of positive samples being
retrieved in the top N ranking, is widely used. However, most of the
conventional loss functions for retrieval models such as softmax cross-entropy
and pairwise comparison methods do not directly optimize Recall@N. Moreover,
those conventional loss functions cannot be customized for the specific
retrieval size N required by each application and thus may lead to sub-optimal
performance. In this paper, we proposed the Customizable Recall@N Optimization
Loss (CROLoss), a loss function that can directly optimize the Recall@N metrics
and is customizable for different choices of N. This proposed CROLoss
formulation defines a more generalized loss function space, covering most of
the conventional loss functions as special cases. Furthermore, we develop the
Lambda method, a gradient-based method that invites more flexibility and can
further boost the system performance. We evaluate the proposed CROLoss on two
public benchmark datasets. The results show that CROLoss achieves SOTA results
over conventional loss functions for both datasets with various choices of
retrieval size N. CROLoss has been deployed onto our online E-commerce
advertising platform, where a fourteen-day online A/B test demonstrated that
CROLoss contributes to a significant business revenue growth of 4.75%.Comment: 9 pages, 5 figures. Accepted by by CIKM 202
Guizhi-jia-houpu-xingzi decoction attenuates ovalbumin-induced allergic asthma via regulation of Toll-like receptor signal pathway
Purpose: To study the effect of Guizhi-jia-houpu-xingzi (GHX) on ovalbumin-induced allergic asthma in rats.Methods: An animal model of allergic asthma (AA) in rats was established by intraperitoneal injection (ip) of ovalbumin (OVA). Thereafter, GHX (375 mg/kg) was administered orally for 7 days. Pulmonary function, inflammatory cells, immunoglobulin E (Ig) E, interleukin-4 (IL)-4 and interferon-Îģ (IFN)-Îģ in serum and bronchoalveolar lavage fluids (BALF) were determined. Furthermore, mRNA expressions of Toll-like receptors (TLRs) signal pathway was determined using real time polymerase chain reaction PCR (q-RT-PCR).Results: GHX (375 mg/kg) significantly decreased respiratory rate (p < 0.01) and Penh value (p < 0.05) when compared with AA rats. The inflammatory cells (p < 0.01) and levels of IL-4 (p < 0.01) and IgE (p < 0.01) were significantly decreased by GHX treatment when compared with AA rats; whereas IFN-Îģ (p < 0.05) was significantly increased. Furthermore, GHX significantly decreased the mRNA expressions of GATA binding protein (GATA)-3 (p < 0.01), TRL-2 (p < 0.01), TRL-4 (p < 0.01), myeloid differentiation factor 88 (MyD88) (p < 0.01), TNF receptor associated factor 6 (TRAF6) (p < 0.01) and Îē-arrestin (p < 0.01) in lung tissues, relative to AA rats. However, GHX treatment led to significant up-regulation of mRNA expression of T-bet (p < 0.01).Conclusion: These results demonstrate that GHX possesses a potential for treating allergic asthma via regulation of Toll-like receptor (TLR) signal pathway. They also provide a scientific basis for the probable use of GHX in clinical treatment of allergic diseases in future.Keywords: Guizhi-jia-houpu-xingzi decoction, Ovalbumin, Allergic asthma, Toll-like recepto
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