79 research outputs found
Distributed Graph Neural Network Training: A Survey
Graph neural networks (GNNs) are a type of deep learning models that are
trained on graphs and have been successfully applied in various domains.
Despite the effectiveness of GNNs, it is still challenging for GNNs to
efficiently scale to large graphs. As a remedy, distributed computing becomes a
promising solution of training large-scale GNNs, since it is able to provide
abundant computing resources. However, the dependency of graph structure
increases the difficulty of achieving high-efficiency distributed GNN training,
which suffers from the massive communication and workload imbalance. In recent
years, many efforts have been made on distributed GNN training, and an array of
training algorithms and systems have been proposed. Yet, there is a lack of
systematic review on the optimization techniques for the distributed execution
of GNN training. In this survey, we analyze three major challenges in
distributed GNN training that are massive feature communication, the loss of
model accuracy and workload imbalance. Then we introduce a new taxonomy for the
optimization techniques in distributed GNN training that address the above
challenges. The new taxonomy classifies existing techniques into four
categories that are GNN data partition, GNN batch generation, GNN execution
model, and GNN communication protocol. We carefully discuss the techniques in
each category. In the end, we summarize existing distributed GNN systems for
multi-GPUs, GPU-clusters and CPU-clusters, respectively, and give a discussion
about the future direction on distributed GNN training
Analysis of the Electrical and Thermal Properties for Magnetic Fe3O4-Coated SiC-Filled Epoxy Composites.
Orderly arranged Silicon carbide (SiC)/epoxy (EP) composites were fabricated. SiC was made magnetically responsive by decorating the surface with iron oxide (Fe3O4) nanoparticles. Three treatment methods, including without magnetization, pre-magnetization and curing magnetization, were used to prepare SiC/EP composites with different filler distributions. Compared with unmodified SiC, magnetic SiC with core-shell structure was conducive to improve the breakdown strength of SiC/EP composites and the maximum enhancement rate was 20.86%. Among the three treatment methods, SiC/EP composites prepared in the curing-magnetization case had better comprehensive properties. Under the action of magnetic field, magnetic SiC were orderly oriented along the direction of an external field, thereby forming SiC chains. The magnetic alignment of SiC restricted the movement of EP macromolecules or polar groups to some extent, resulting in the decrease in the dielectric constant and dielectric loss. The SiC chains are equivalent to heat flow channels, which can improve the heat transfer efficiency, and the maximum improvement rate was 23.6%. The results prove that the orderly arrangement of SiC had a favorable effect on dielectric properties and thermal conductivity of SiC/EP composites. For future applications, the orderly arranged SiC/EP composites have potential for fabricating insulation materials in the power electronic device packaging field
Regulation of the Optical Properties of Cellulose Nanocrystal Films by Sealed Deposition Treatment
Cellulose nanocrystal (CNC) can self-assemble and arrange at specific concentrations, imparting unique optical properties to the system. This paper investigated the effects of sealed deposition time and CNC concentration on the formation and alignment of cholesteric liquid crystals within the naturally dried films by analyzing the changes of CNC films in macroscopic color, UV-vis spectra, polarization optics, microscopic morphology, and crystal structure to elucidate the mechanism of CNC self-assembly behavior during the formation of CNC films. The results showed that when the sealed deposition time was extended to 48 h, the structural color development range and the long-range ordering of the cholesteric phase structure of CNC films were considerably enhanced. As the concentration increased, the CNC particle spacing decreased, the torsion angle between neighboring particles increased, and the pitch was compressed, decreasing from 480 nm to 344 nm. The results of polarized light microscopy analysis demonstrated that the sealed deposition treatment had a significant advantage in the formation of long-range ordered cholesteric phase structure in high-concentration CNC suspensions. The results of this research indicated that prolonging the sealed deposition time and increasing the CNC concentration could enhance the improvement of long-range orderliness in the films and promote the formation of cholesteric phase structural domains. This further improved the scientific basis for the preparation of CNC-based smart packaging materials and had a positive effect on the development of new visual food packaging and inspection materials
Model-enhanced Vector Index
Embedding-based retrieval methods construct vector indices to search for
document representations that are most similar to the query representations.
They are widely used in document retrieval due to low latency and decent recall
performance. Recent research indicates that deep retrieval solutions offer
better model quality, but are hindered by unacceptable serving latency and the
inability to support document updates. In this paper, we aim to enhance the
vector index with end-to-end deep generative models, leveraging the
differentiable advantages of deep retrieval models while maintaining desirable
serving efficiency. We propose Model-enhanced Vector Index (MEVI), a
differentiable model-enhanced index empowered by a twin-tower representation
model. MEVI leverages a Residual Quantization (RQ) codebook to bridge the
sequence-to-sequence deep retrieval and embedding-based models. To
substantially reduce the inference time, instead of decoding the unique
document ids in long sequential steps, we first generate some semantic virtual
cluster ids of candidate documents in a small number of steps, and then
leverage the well-adapted embedding vectors to further perform a fine-grained
search for the relevant documents in the candidate virtual clusters. We
empirically show that our model achieves better performance on the commonly
used academic benchmarks MSMARCO Passage and Natural Questions, with comparable
serving latency to dense retrieval solutions
Multiple influence of immune cells in the bone metastatic cancer microenvironment on tumors
Bone is a common organ for solid tumor metastasis. Malignant bone tumor becomes insensitive to systemic therapy after colonization, followed by poor prognosis and high relapse rate. Immune and bone cells in situ constitute a unique immune microenvironment, which plays a crucial role in the context of bone metastasis. This review firstly focuses on lymphatic cells in bone metastatic cancer, including their function in tumor dissemination, invasion, growth and possible cytotoxicity-induced eradication. Subsequently, we examine myeloid cells, namely macrophages, myeloid-derived suppressor cells, dendritic cells, and megakaryocytes, evaluating their interaction with cytotoxic T lymphocytes and contribution to bone metastasis. As important components of skeletal tissue, osteoclasts and osteoblasts derived from bone marrow stromal cells, engaging in ‘vicious cycle’ accelerate osteolytic bone metastasis. We also explain the concept tumor dormancy and investigate underlying role of immune microenvironment on it. Additionally, a thorough review of emerging treatments for bone metastatic malignancy in clinical research, especially immunotherapy, is presented, indicating current challenges and opportunities in research and development of bone metastasis therapies
Measuring and Valuing Health-Related Quality of Life among Children and Adolescents in Mainland China - A Pilot Study
Background: The Child Health Utility 9D (CHU9D), a new generic preference-based health-related quality of life (HRQoL)
instrument, has been validated for use in young people in both the UK and Australia. The main objectives of this study were
to examine the feasibility of using a Chinese version of the CHU9D (CHU9D-CHN) to assess HRQoL and to investigate the
association of physical activity, homework hours and sleep duration with HRQoL in children and adolescents in Mainland
China.
Methods: Data were collected using a multi-stage sampling method from grades 4–12 students in May 2013 in Nanjing,
China. Consenting participants (N = 815) completed a self-administered questionnaire including the CHU9D-CHN instrument
and information on physical activity, homework and sleep duration, self-reported health status, and socio-demographic
characteristics. Descriptive and multivariate linear regression analyses were undertaken. CHU9D-CHN utility scores were
generated by employing two scoring algorithms currently available for the instrument, the first derived from UK adults
utilising the standard gamble (SG) valuation method and the second derived from Australian adolescents utilising the bestworst
scaling (BWS) method.
Results: It was found that CHU9D utility scores discriminated well in relation to self-reported health status and that better
health status was significantly associated with higher utility scores regardless of which scoring algorithm was employed
(both p,0.001). The adjusted mean utilities were significantly higher for physically active than inactive students (0.023 by
SG, 0.029 by BWS scoring methods, p,0.05). An additional hour of doing homework and sleep duration were, separately,
associated with mean utilities of 20.019 and 0.032 based on SG, and 20.021 and 0.040 according to BWS scoring algorithms
(p,0.01).
Conclusion: The CHU9D-CHN shows promise for measuring and valuing the HRQoL of children and adolescents in China.
Levels of self-reported physical activity, homework and sleep time were important influencers of utility scores
Phylogenomic analyses provide insights into primate evolution
Comparative analysis of primate genomes within a phylogenetic context is essential for understanding the evolution of human genetic architecture and primate diversity. We present such a study of 50 primate species spanning 38 genera and 14 families, including 27 genomes first reported here, with many from previously less well represented groups, the New World monkeys and the Strepsirrhini. Our analyses reveal heterogeneous rates of genomic rearrangement and gene evolution across primate lineages. Thousands of genes under positive selection in different lineages play roles in the nervous, skeletal, and digestive systems and may have contributed to primate innovations and adaptations. Our study reveals that many key genomic innovations occurred in the Simiiformes ancestral node and may have had an impact on the adaptive radiation of the Simiiformes and human evolution
Target Identification via Multi-View Multi-Task Joint Sparse Representation
Recently, the monitoring efficiency and accuracy of visible and infrared video have been relatively low. In this paper, we propose an automatic target identification method using surveillance video, which provides an effective solution for the surveillance video data. Specifically, a target identification method via multi-view and multi-task sparse learning is proposed, where multi-view includes various types of visual features such as textures, edges, and invariant features. Each view of a candidate is regarded as a template, and the potential relationship between different tasks and different views is considered. These multiple views are integrated into the multi-task spare learning framework. The proposed MVMT method can be applied to solve the ship’s identification. Extensive experiments are conducted on public datasets, and custom sequence frames (i.e., six sequence frames from ship videos). The experimental results show that the proposed method is superior to other classical methods, qualitatively and quantitatively
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