246 research outputs found

    Few-shot Text Classification with Dual Contrastive Consistency

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    In this paper, we explore how to utilize pre-trained language model to perform few-shot text classification where only a few annotated examples are given for each class. Since using traditional cross-entropy loss to fine-tune language model under this scenario causes serious overfitting and leads to sub-optimal generalization of model, we adopt supervised contrastive learning on few labeled data and consistency-regularization on vast unlabeled data. Moreover, we propose a novel contrastive consistency to further boost model performance and refine sentence representation. After conducting extensive experiments on four datasets, we demonstrate that our model (FTCC) can outperform state-of-the-art methods and has better robustness.Comment: 8 pages, 2 figures, under revie

    Risk Assessment of Nautical Navigational Environment Based on Grey Fixed Weight Cluster

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    In order to set up a mathematical model suitable for nautical navigational environment risk evaluation and systematically master the navigational environment risk characteristics of the Qiongzhou Strait in a quantitative way, a risk assessment model with approach steps is set up based on the grey fixed weight cluster (GFWC). The evaluation index system is structured scientifically through both literature review and expert investigation. The relative weight of each index is designed to be obtained via fuzzy analytic hierarchy process (FAHP); Index membership degree of every grey class is proposed to be achieved by fuzzy statistics (FS) to avoid the difficulty of building whiten weight functions. By using the model, nautical navigational environment risk of the Qiongzhou Strait is determined at a “moderate” level according to the principle of maximum membership degree. The comprehensive risk evaluation of the Qiongzhou Strait nautical navigational environment can provide theoretical reference for implementing targeted risk control measures. It shows that the constructed GFWC risk assessment model as well as the presented steps are workable in case of incomplete information. The proposed strategy can excavate the collected experts’ knowledge mathematically, quantify the weight of each index and risk level, and finally lead to a comprehensive risk evaluation result. Besides, the adoptions of probability and statistic theory, fuzzy theory, aiming at solving the bottlenecks in case of uncertainty, will give the model a better adaptability and executability.</p

    Energy Efficient Indirect Evaporative Air Cooling

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    An energy-saving and environmentally friendly air-conditioning method has been proposed. The key component is a novel indirect evaporative heat exchanger (IEHX) based on the M-cycle. In this design, the compact IEHX is able to produce sub-wet-bulb cooling and reduce the air temperature approaching dew-point temperature. This chapter aims to achieve a fundamental understanding of the novel IEHX. A numerical model has been developed and validated by comparing the simulated outlet air conditions against experimental data. The model showed a good agreement with the experimental findings. Employing the validated numerical model, we have theoretically investigated the heat and mass transfer behavior occurred in the IEHX. The detailed cooling process has been analyzed on the psychrometric chart. In addition, the effects of varying inlet conditions and airflow passage dimensions on the cooling efficiency have been studied. By analyzing the thermal performance of the IEHX, we have provided possible suggestions to improve the performance of the dew-point cooler and enable it to attain higher cooling effectiveness

    circRNA-SMO upregulates CEP85 to promote proliferation and migration of glioblastoma via sponging miR-326

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    Circular RNAs (circRNAs) play an important role in cancer development by sponging microRNAs (miRNAs) to regulate the signaling axis. However, more comprehensive mechanisms of circRNAs in glioblastoma need to be elucidated. RT-qPCR was used to detect the expression levels of circRNA-SMO and miR-326. Dual-luciferase reporter assays were conducted to verify the interaction among circRNA-SMO, miR-326, and CEP85. Flow cytometric analysis was performed to detect apoptosis. Western blotting was used to determine the protein levels of the different molecules. Animal xenograft experiments were performed to evaluate the role of circRNA-SMO in vivo. CircRNA-SMO was upregulated in glioblastoma tissues and glioblastoma cells. CircRNA-SMO downregulation inhibited the viability and colonyforming ability of the glioblastoma cells. In addition, miR-326 was downregulated in glioblastoma cells, which was verified to sponge circRNA-SMO and interact with CEP85. Moreover, circRNA-SMO inhibition induced the elevation of miR-326 and apoptosis, accompanied by a decrease in CEP85. CircRNA-SMO knockdown-mediated tumor inhibition was prevented by an miR-326 inhibitor. Furthermore, circRNA-SMO inhibition inhibited tumor growth in vivo, accompanied by an increase in miR-326 and a decline in CEP85 in tumor tissues. Conclusions. CircRNA-SMO sponges miR-326 to promote glioblastoma proliferation and migration by upregulating CEP85 expression. This study clarified the role of circRNA-SMO in the development of glioblastoma, providing novel insights for its treatment

    Nonlinear flow in low permeability reservoirs: Modelling and experimental verification

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    The low-permeability reservoirs are of heavy heterogeneity, low permeability, fine oil-water passages, strong resistance during flow, and the significant interaction between solid and liquid interfaces causes the flow of fluid in reservoir deviating from the Darcy’s law. There is no agreement on the interaction between the various factors in seepage process and the influence of seepage law. The boundary layer exists when liquid flow in micro-tubes and nano-tubes, and the boundary layer decreases with the increase of driving force, and the maximum value of boundary layer ratio is equal to 1. Based on the capillary boundal model and the boundary layer theory, a new exponential seepage model for low permeability reservoirs was proposed. Some experiments of water flow with different pressure gradient were carried out in low permeability cores with permeability of 4 to 8 milidarcy in natural rock cores from an oilfield in China, and the nonlinear model is of good agreement with the single-phase water flooding experiments of these cores. The results demonstrate that the physical meaning of each parameter of the new model is clear and it can be applied to describe the nonlinear characteristics of low permeability reservoirs. The large driving force can overcome disadvantages in the developments of low permeability reservoirs.Cited as: Song, F., Bo, L., Zhang, S., Sun, Y. Nonlinear flow in low permeability reservoirs: Modelling and experimental verification. Advances in Geo-Energy Research, 2019, 3(1): 76-81, doi: 10.26804/ager.2019.01.0

    The preparation and photocatalytic activities of Z-scheme pillared composites composed of Zr-EDTA and 2D titanate nanosheets

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    Abstract(#br)To fabricate mesoporous photocatalysts with delaminated structures, the exfoliated and layered titanate in an aqueous solution was reassembled in the presence of a Zr-EDTA complex suspension by using an exfoliation-restacking route. Powder X-ray diffraction and HR-TEM clearly revealed that the Zr-EDTA complexes were intercalated into the interlayer of titanate sheets, and the present nanocomposite possessed an enhanced specific surface area (~ 193 m 2 g −1 ) with a diameter of 4.32 nm. The XPS and UV–Vis spectra showed interaction between the titanate nanosheets and the guest complex in the pillared system, where in the guest accepted and transported photo-generated carriers, and titanate nanosheets provided active reactive sites. The result nanohybrids exhibited excellent..

    Qd-tree: Learning Data Layouts for Big Data Analytics

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    Corporations today collect data at an unprecedented and accelerating scale, making the need to run queries on large datasets increasingly important. Technologies such as columnar block-based data organization and compression have become standard practice in most commercial database systems. However, the problem of best assigning records to data blocks on storage is still open. For example, today's systems usually partition data by arrival time into row groups, or range/hash partition the data based on selected fields. For a given workload, however, such techniques are unable to optimize for the important metric of the number of blocks accessed by a query. This metric directly relates to the I/O cost, and therefore performance, of most analytical queries. Further, they are unable to exploit additional available storage to drive this metric down further. In this paper, we propose a new framework called a query-data routing tree, or qd-tree, to address this problem, and propose two algorithms for their construction based on greedy and deep reinforcement learning techniques. Experiments over benchmark and real workloads show that a qd-tree can provide physical speedups of more than an order of magnitude compared to current blocking schemes, and can reach within 2X of the lower bound for data skipping based on selectivity, while providing complete semantic descriptions of created blocks.Comment: ACM SIGMOD 202

    Interocular Shift of Visual Attention Enhances Stereopsis and Visual Acuities of Anisometropic Amblyopes beyond the Critical Period of Visual Development: A Novel Approach

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    Aims. Increasing evidence shows that imbalanced suppressive drive prior to binocular combination may be the key factor in amblyopia. We described a novel binocular approach, interocular shift of visual attention (ISVA), for treatment of amblyopia in adult patients. Methods. Visual stimuli were presented anaglyphically on a computer screen. A square target resembling Landolt C had 2 openings, one in red and one in cyan color. Through blue-red goggles, each eye could only see one of the two openings. The patient was required to report the location of the opening presented to the amblyopic eye. It started at an opening size of 800 sec of arc, went up and down in 160 sec of arc step, and stopped when reaching the 5th reversals. Ten patients with anisometropic amblyopia older than age 14 (average age: 26.7) were recruited and received ISVA treatment for 6 weeks, with 2 training sessions per day. Results. Both Titmus stereopsis (z = −2.809, P = 0.005) and Random-dot stereopsis (z = −2.317, P = 0.018) were significantly improved. Average improvement in best corrected visual acuity (BCVA) was 0.74 line (t = 5.842, P < 0.001). Conclusions. The ISVA treatment may be effective in treating amblyopia and restoring stereoscopic function

    Identification of Dominant Spoilage Bacteria in Chicken Feet with Pickled Peppers and Analysis of Their Spoilage Capacity

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    The dominant spoilage bacteria in chicken feet with pickled peppers were analyzed by high-throughput sequencing technology and isolated by the traditional culture method to evaluate their spoilage capacity by back inoculation. The results showed that the dominant genus identified was Bacillus, and four dominant strains were identified including B. methylotrophicus, B. velezensis, B. subtilis and B. safensis. All these strains were able to produce protease and lipase activity. Among them, B. safensis showed the strongest protease activity (51.19 U/mL), while B. methylotrophicus showed the strongest lipase activity (3.75 U/mL). The pH, total volatile basic nitrogen (TVB-N) content and thiobarbituric acid reactive substances (TBARS) value of the samples inoculated with each of the four Bacillus strains were higher than those of the uninoculated control group, indicating that all four Bacillus strains had spoilage capacity. This study will provided a theoretical basis for preventing and controlling the spoilage of chicken feet with pickled peppers and extending its shelf life
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