1,551 research outputs found

    Number of Repetitions in Re-randomization Tests

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    In covariate-adaptive or response-adaptive randomization, the treatment assignment and outcome can be correlated. Under this situation, re-randomization tests are a straightforward and attractive method to provide valid statistical inference. In this paper, we investigate the number of repetitions in the re-randomization tests. This is motivated by the group sequential design in clinical trials, where the nominal significance bound can be very small at an interim analysis. Accordingly, re-randomization tests lead to a very large number of required repetitions, which may be computationally intractable. To reduce the number of repetitions, we propose an adaptive procedure and compare it with multiple approaches under pre-defined criteria. Monte Carlo simulations are conducted to show the performance of different approaches in a limited sample size. We also suggest strategies to reduce total computation time and provide practical guidance in preparing, executing and reporting before and after data are unblinded at an interim analysis, so one can complete the computation within a reasonable time frame

    Deep Structured Feature Networks for Table Detection and Tabular Data Extraction from Scanned Financial Document Images

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    Automatic table detection in PDF documents has achieved a great success but tabular data extraction are still challenging due to the integrity and noise issues in detected table areas. The accurate data extraction is extremely crucial in finance area. Inspired by this, the aim of this research is proposing an automated table detection and tabular data extraction from financial PDF documents. We proposed a method that consists of three main processes, which are detecting table areas with a Faster R-CNN (Region-based Convolutional Neural Network) model with Feature Pyramid Network (FPN) on each page image, extracting contents and structures by a compounded layout segmentation technique based on optical character recognition (OCR) and formulating regular expression rules for table header separation. The tabular data extraction feature is embedded with rule-based filtering and restructuring functions that are highly scalable. We annotate a new Financial Documents dataset with table regions for the experiment. The excellent table detection performance of the detection model is obtained from our customized dataset. The main contributions of this paper are proposing the Financial Documents dataset with table-area annotations, the superior detection model and the rule-based layout segmentation technique for the tabular data extraction from PDF files

    FasterX: Real-Time Object Detection Based on Edge GPUs for UAV Applications

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    Real-time object detection on Unmanned Aerial Vehicles (UAVs) is a challenging issue due to the limited computing resources of edge GPU devices as Internet of Things (IoT) nodes. To solve this problem, in this paper, we propose a novel lightweight deep learning architectures named FasterX based on YOLOX model for real-time object detection on edge GPU. First, we design an effective and lightweight PixSF head to replace the original head of YOLOX to better detect small objects, which can be further embedded in the depthwise separable convolution (DS Conv) to achieve a lighter head. Then, a slimmer structure in the Neck layer termed as SlimFPN is developed to reduce parameters of the network, which is a trade-off between accuracy and speed. Furthermore, we embed attention module in the Head layer to improve the feature extraction effect of the prediction head. Meanwhile, we also improve the label assignment strategy and loss function to alleviate category imbalance and box optimization problems of the UAV dataset. Finally, auxiliary heads are presented for online distillation to improve the ability of position embedding and feature extraction in PixSF head. The performance of our lightweight models are validated experimentally on the NVIDIA Jetson NX and Jetson Nano GPU embedded platforms.Extensive experiments show that FasterX models achieve better trade-off between accuracy and latency on VisDrone2021 dataset compared to state-of-the-art models.Comment: 12 pages, 7 figure

    Multiband superconductivity and a deep gap minimum evidenced by specific heat in KCa2_2(Fe1βˆ’x_{1-x}Nix_x)4_4As4_4F2_2

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    Specific heat can explore low-energy quasiparticle excitations of superconductors, so it is a powerful tool for bulk measurement on the superconducting gap structure and pairing symmetry. Here, we report an in-depth investigation on the specific heat of the multiband superconductors KCa2_2(Fe1βˆ’x_{1-x}Nix_x)4_4As4_4F2_2 (xx = 0, 0.05, 0.13) single crystals and the overdoped non-superconducting one with xx = 0.17. For the samples with xx = 0 and xx = 0.05, the magnetic field induced specific heat coefficient Δγ(H)\Delta\gamma(H) in the low temperature limit increases rapidly below 2 T, then it rises slowly above 2 T. Using the non-superconducting sample with xx = 0.17 as a reference, and applying a mixed model that combines Debye and Einstein modes, the specific heat of phonon background for various superconducting samples can be fitted and the detailed information of the electronic specific heat is obtained. Through comparative analyses, it is found that the energy gap structure including two ss-wave gaps and an extended ss-wave gap with large anisotropy can reasonably describe the electronic specific heat data. According to these results, we suggest that at least one anisotropic superconducting gap with a deep gap minimum should exist in this multiband system. With the doping of Ni, the TcT_c of the sample decreases along with the decrease of the large ss-wave gap, but the extended ss-wave gap increases due to the enlarged electron pockets via adding more electrons. Despite these changes, the general properties of the gap structure remain unchanged versus doping Ni. In addition, the calculation of condensation energy of the parent and doped samples shows the rough consistency with the correlation of U0∝TcnU_0 \propto {T_c}^n with nn = 3-4, which is beyond the understanding of the BCS theory

    Research on low frequency ripple suppression technology of inverter based on model prediction

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    The low frequency ripple of the input side current of the single-phase inverter will reduce the efficiency of the power generation system and affect the overall performance of the system. Aiming at this problem, this paper proposes a two-modal modulation method and its MPC multi-loop composite control strategy on the circuit topology of a single-stage boost inverter with a buffer unit. The control strategy achieves the balance of active power on both sides of AC and DC by controlling the stable average value of the buffer capacitor voltage, and provides a current reference for inductance current of the DC input side. At the same time, the MPC controller uses the minimum inductor current error as the cost function to control inductor current to track its reference to achieve low frequency ripple suppression of the input current. In principle, it is expounded that the inverter using the proposed control strategy has better low frequency ripple suppression effect than the multi-loop PI control strategy, and the conclusion is proved by the simulation data. Finally, an experimental device of a single-stage boost inverter using MPC multi-loop composite control strategy is designed and fabricated, and the experimental results show that the proposed research scheme has good low frequency ripple suppression effect and strong adaptability to different types of loads

    How is Vaping Framed on Online Knowledge Dissemination Platforms?

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    We analyze 1,888 articles and 1,119,453 vaping posts to study how vaping is framed across multiple knowledge dissemination platforms (Wikipedia, Quora, Medium, Reddit, Stack Exchange, wikiHow). We use various NLP techniques to understand these differences. For example, n-grams, emotion recognition, and question answering results indicate that Medium, Quora, and Stack Exchange are appropriate venues for those looking to transition from smoking to vaping. Other platforms (Reddit, wikiHow) are more for vaping hobbyists and may not sufficiently dissuade youth vaping. Conversely, Wikipedia may exaggerate vaping harms, dissuading smokers from transitioning. A strength of our work is how the different techniques we have applied validate each other. Based on our results, we provide several recommendations. Stakeholders may utilize our findings to design informational tools to reinforce or mitigate vaping (mis)perceptions online.Comment: arXiv admin note: text overlap with arXiv:2206.07765, arXiv:2206.0902

    CNTF Induces Regeneration of Cone Outer Segments in a Rat Model of Retinal Degeneration

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    Cone photoreceptors are responsible for color and central vision. In the late stage of retinitis pigmentosa and in geographic atrophy associated with age-related macular degeneration, cone degeneration eventually causes loss of central vision. In the present work, we investigated cone degeneration secondary to rod loss in the S334ter-3 transgenic rats carrying the rhodopsin mutation S334ter.Recombinant human ciliary neurotrophic factor (CNTF) was delivered by intravitreal injection to the left eye of an animal, and vehicle to the right eye. Eyes were harvested 10 days after injection. Cone outer segments (COS), and cell bodies were identified by staining with peanut agglutinin and cone arrestin antibodies in whole-mount retinas. For long-term treatment with CNTF, CNTF secreting microdevices were implanted into the left eyes at postnatal day (PD) 20 and control devices into the right eyes. Cone ERG was recorded at PD 160 from implanted animals. Our results demonstrate that an early sign of cone degeneration is the loss of COS, which concentrated in many small areas throughout the retina and is progressive with age. Treatment with CNTF induces regeneration of COS and thus reverses the degeneration process in early stages of cone degeneration. Sustained delivery of CNTF prevents cones from degeneration and helps them to maintain COS and light-sensing function.Loss of COS is an early sign of secondary cone degeneration whereas cell death occurs much later. At early stages, degenerating cones are capable of regenerating outer segments, indicating the reversal of the degenerative process. Sustained delivery of CNTF preserves cone cells and their function. Long-term treatment with CNTF starting at early stages of degeneration could be a viable strategy for preservation of central vision for patients with retinal degenerations

    Effect of retrograde intrarenal surgery on the inflammatory reaction, renal function indicators and clinical efficacy in male patients with kidney stones

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    To investigate the effect of retrograde intrarenal surgery (RIRS) and percutaneous nephrolithotripsy on the inflammatory reaction, renal function indicators and clinical efficacy in male patients with kidney stones. 122 male patients with kidney stones were separated into the study group (n = 61) and the control group (n = 61) in terms of distinct clinical treatment regimens. The study group was treated with retrograde intrarenal surgery, while the control group was treated with percutaneous nephrolithotripsy. Inflammatory reaction indicators (Interleukin-6 (IL-6), Interleukin-10 (IL-10), serum tumor necrosis factor-Ξ± (TNF-Ξ±)), renal function indicators (blood urea nitrogen (BUN), serum creatinine (Scr), blood uric acid (BUA), serum Ξ²2 microglobulin (BMG)) and other clinical indicators (operative time, hospital stay, intraoperative blood loss, Visual analogue scale (VAS) pain score, complications) were observed and compared. Upon the treatment, significantly lowered inflammatory factors including IL-6, IL-10, TNF-Ξ± and renal function indicators including BUN, Scr, BUA, BMG were shown in study group. Notably shortened operative time and hospital stay were presented in study group with lowered intraoperative blood loss and pain score. The total incidence of complications in study group was 3.28%, significantly lower than 14.75% in control group. Compared with percutaneous nephrolithotripsy, retrograde intrarenal surgery for the treatment of male kidney stones with a diameter of less than 3 cm can improve the inflammatory reaction of male patients, maximize the preservation of renal function indicators, and eminently promote the clinical comprehensive efficacy
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