204 research outputs found

    Constructing Sample-to-Class Graph for Few-Shot Class-Incremental Learning

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    Few-shot class-incremental learning (FSCIL) aims to build machine learning model that can continually learn new concepts from a few data samples, without forgetting knowledge of old classes. The challenges of FSCIL lies in the limited data of new classes, which not only lead to significant overfitting issues but also exacerbates the notorious catastrophic forgetting problems. As proved in early studies, building sample relationships is beneficial for learning from few-shot samples. In this paper, we promote the idea to the incremental scenario, and propose a Sample-to-Class (S2C) graph learning method for FSCIL. Specifically, we propose a Sample-level Graph Network (SGN) that focuses on analyzing sample relationships within a single session. This network helps aggregate similar samples, ultimately leading to the extraction of more refined class-level features. Then, we present a Class-level Graph Network (CGN) that establishes connections across class-level features of both new and old classes. This network plays a crucial role in linking the knowledge between different sessions and helps improve overall learning in the FSCIL scenario. Moreover, we design a multi-stage strategy for training S2C model, which mitigates the training challenges posed by limited data in the incremental process. The multi-stage training strategy is designed to build S2C graph from base to few-shot stages, and improve the capacity via an extra pseudo-incremental stage. Experiments on three popular benchmark datasets show that our method clearly outperforms the baselines and sets new state-of-the-art results in FSCIL

    pH Sensitive Dextran Coated Fluorescent Nanodiamonds as a Biomarker for HeLa Cells Endocytic Pathway and Increased Cellular Uptake

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    Fluorescent nanodiamonds are a useful for biosensing of intracellular signaling networks or environmental changes (such as temperature, pH or free radical generation). HeLa cells are interesting to study with these nanodiamonds since they are a model cell system that is widely used to study cancer-related diseases. However, they only internalize low numbers of nanodiamond particles very slowly via the endocytosis pathway. In this work, we show that pH-sensitive, dextran-coated fluorescent nanodiamonds can be used to visualise this pathway. Additionally, this coating improved diamond uptake in HeLa cells by 5.3 times (*** p < 0.0001) and decreased the required time for uptake to only 30 min. We demonstrated further that nanodiamonds enter HeLa cells via endolysosomes and are eventually expelled by cells

    A Discussion on the Detachment Structural Deformation and Its Influence on Pore Structure Evolution in Shale on the Western of the Xuefeng Mountain, South China

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    Detachment structures occur widely in the crust, and it is the commonest and most important deformation type developed in the region between orogenic belts and basins. Organic-rich shale, as the weak layers, usually acts as slippery layers in detachment structural deformation systems. The “comb-like” and “tough-like” fold belts on the western side of the Xuefeng Mountain result from the multilayer detachment, and their formation is different from the typical Jura type structures. The reason is that there are several detachment layers and detachment systems in the stratigraphic column from the Neoproterozoic upwards to the Mesozoic in the study area. As the stress decoupling role, the shale slippery layers tend to undergo strong deformation in the detachment systems and impacted on pore structure evolution in the shale. In order to obtain the detachment structural deformation and its influence on pore structure evolution in shale on the Middle and Upper Yangtze, the structural and textural, geochemical and mineralogical properties analysis, porosity and pore structure feature investigations are performed using shale samples collected from the same shale bed of the Longmaxi Formations (Lower Silurian) of Western of the Xuefeng Mountain, South China

    Revisiting the globalisation-welfare state Nexus: what about the quality of the social welfare?

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    A large amount of literature examines the effects of globalisation on the size of the welfare state. Unlike previous papers, this article studies globalisation’s effects on the quality of social welfare. For this purpose, we use the annual panel dataset of 169 countries from 1970 to 2018. The findings indicate that a higher level of globalisation leads to a higher quality of the welfare state. This evidence is valid when the countries are divided according to their income levels, such as low-income, middle-income, and high-income economies. In addition, these results remain robust when various sensitivity analyses are implemented, such as using different indicators of globalisation, utilising different estimation techniques, including various controls, and excluding outliers

    Dual-Polarized On-Chip Antenna for 300 GHz Full-Duplex Communication System

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    This paper presents a novel design of compact orthogonally polarized on-chip antenna to realize 300 GHz full-duplex communication system with high isolation. It consists of a dipole antenna for horizontal polarization and a disk-loaded monopole antenna for vertical polarization. They are in good cross-polarization state with more than 90 dB of self-interference suppression and then can be used to achieve good isolation between transmitting and receiving antennas. In addition, two dual-polarized antennas have been adopted in two separated transceivers to study their isolation performance. Furthermore, this compact antenna only occupies an active area of 390 μm × 300 μm × 78 μm and can be used for multiple-input multiple-output application as well

    Photometric and Spectroscopic Studies of V582 Lyr and V1016 Oph

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    We present new CCD photometric light curves about two eclipsing binaries of V582 Lyr and V1016 Oph. Our observations were carried out by the SARA 91.4 cm telescope of America in 2016 and the 60 cm telescope of Chile in 2018. V582 Lyr’s spectra type was classified as K5, and its radial velocity was determined using the LAMOST spectral survey. There are absorptions in the observed Hα line and excess emissions in the subtracted Hα line, which show weak chromospheric activity. We obtained the updated ephemeris information for V582 Lr and V1016 Oph, and found that their orbital periods are both decreasing.We concluded that the decreased rate is −0.474 (±0.011)Å~10−7 days yr−1 for V582 Lyr and 3.460 (±0.014)Å~10−7 days yr−1 for V1016 Oph. For V582 Lyr, the period variation was interpreted as a mass transfer from the secondary component to the primary one, and the corresponding rate is dM2/dt=−1.10 (±0.03)Å~10−7 Me yr−1. For V1016 Oph, we explain it by transferring from the primary component to the secondary one, and the corresponding rate is dM1/dt=−2.69 (±0.04)Å~10−7 Me yr−1. The photometric solution of V1016 Oph was obtained by analyzing the CCD photometry with the Wilson–Devinney program. We also obtained the orbital parameters of V1016 Oph by simultaneously analyzing our BVRI light curves and radial-velocity curve from the LAMOST low-resolution spectral survey. Finally, our orbital solution shows that they are contact eclipsing binaries with contact factors of 3.35 (±0.08)% for V582 Lyr and 41.0 (±0.1)% for V1016 Oph

    VoxelFormer: Bird's-Eye-View Feature Generation based on Dual-view Attention for Multi-view 3D Object Detection

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    In recent years, transformer-based detectors have demonstrated remarkable performance in 2D visual perception tasks. However, their performance in multi-view 3D object detection remains inferior to the state-of-the-art (SOTA) of convolutional neural network based detectors. In this work, we investigate this issue from the perspective of bird's-eye-view (BEV) feature generation. Specifically, we examine the BEV feature generation method employed by the transformer-based SOTA, BEVFormer, and identify its two limitations: (i) it only generates attention weights from BEV, which precludes the use of lidar points for supervision, and (ii) it aggregates camera view features to the BEV through deformable sampling, which only selects a small subset of features and fails to exploit all information. To overcome these limitations, we propose a novel BEV feature generation method, dual-view attention, which generates attention weights from both the BEV and camera view. This method encodes all camera features into the BEV feature. By combining dual-view attention with the BEVFormer architecture, we build a new detector named VoxelFormer. Extensive experiments are conducted on the nuScenes benchmark to verify the superiority of dual-view attention and VoxelForer. We observe that even only adopting 3 encoders and 1 historical frame during training, VoxelFormer still outperforms BEVFormer significantly. When trained in the same setting, VoxelFormer can surpass BEVFormer by 4.9% NDS point. Code is available at: https://github.com/Lizhuoling/VoxelFormer-public.git

    Relaxometry for detecting free radical generation during Bacteria's response to antibiotics

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    Free radical generation plays a key role in killing bacteria by antibiotics. However, radicals are short-lived and reactive, and thus difficult to detect for the state of the art. Here we use a technique which allows optical nanoscale magnetic resonance imaging (MRI) to detect radical generation on the scale of single bacteria. We demonstrate that the radical generation in Staphylococcus aureus increases in the presence of UV irradiation as well as vancomycin and is dependent on the antibiotic's dose. With a method based on ensembles of nitrogen vacancy (NV) centers in diamond, we were able to follow the radical formation near individual bacteria over the whole duration of the experiment to reveal the dynamics of radical generation. Using this new approach, we observed free radical concentrations within nanoscale voxels around the diamond particles and determined its exact timing depending on the antibiotic dose. Since changes in the response to antibiotics emerge in only a few bacteria of the entire population, such a single-cell approach can prove highly valuable for research into drug resistance
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