124 research outputs found

    Pair-wise Layer Attention with Spatial Masking for Video Prediction

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    Video prediction yields future frames by employing the historical frames and has exhibited its great potential in many applications, e.g., meteorological prediction, and autonomous driving. Previous works often decode the ultimate high-level semantic features to future frames without texture details, which deteriorates the prediction quality. Motivated by this, we develop a Pair-wise Layer Attention (PLA) module to enhance the layer-wise semantic dependency of the feature maps derived from the U-shape structure in Translator, by coupling low-level visual cues and high-level features. Hence, the texture details of predicted frames are enriched. Moreover, most existing methods capture the spatiotemporal dynamics by Translator, but fail to sufficiently utilize the spatial features of Encoder. This inspires us to design a Spatial Masking (SM) module to mask partial encoding features during pretraining, which adds the visibility of remaining feature pixels by Decoder. To this end, we present a Pair-wise Layer Attention with Spatial Masking (PLA-SM) framework for video prediction to capture the spatiotemporal dynamics, which reflect the motion trend. Extensive experiments and rigorous ablation studies on five benchmarks demonstrate the advantages of the proposed approach. The code is available at GitHub

    Triple-View Knowledge Distillation for Semi-Supervised Semantic Segmentation

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    To alleviate the expensive human labeling, semi-supervised semantic segmentation employs a few labeled images and an abundant of unlabeled images to predict the pixel-level label map with the same size. Previous methods often adopt co-training using two convolutional networks with the same architecture but different initialization, which fails to capture the sufficiently diverse features. This motivates us to use tri-training and develop the triple-view encoder to utilize the encoders with different architectures to derive diverse features, and exploit the knowledge distillation skill to learn the complementary semantics among these encoders. Moreover, existing methods simply concatenate the features from both encoder and decoder, resulting in redundant features that require large memory cost. This inspires us to devise a dual-frequency decoder that selects those important features by projecting the features from the spatial domain to the frequency domain, where the dual-frequency channel attention mechanism is introduced to model the feature importance. Therefore, we propose a Triple-view Knowledge Distillation framework, termed TriKD, for semi-supervised semantic segmentation, including the triple-view encoder and the dual-frequency decoder. Extensive experiments were conducted on two benchmarks, \ie, Pascal VOC 2012 and Cityscapes, whose results verify the superiority of the proposed method with a good tradeoff between precision and inference speed

    Microstructure and Mechanical Properties of a-CN x Films Prepared by Bias Voltage Assisted PLD with Carbon Nitride Target

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    International audienceAmorphous carbon nitride (a-CN x) films were deposited on silicon substrates using pulsed laser deposition technique (PLD) with a carbon nitride target and a negative bias voltage up to -120 V. The microstructure, chemical composition, bonding configuration and mechanical properties of the films were characterized by using scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, nanoindentation and ball-on-disc abrasion test. The results show that the negative bias voltage promotes the formation of sp 3 hybridization bonding and leads to a great improvement of nitrogen content (up to 38 at.%) in the films. With an increasing bias voltage from -40 V to -120 V, the nitrogen content and the fraction of sp 3 hybridization bonding Corresponding author

    The Prevalence of Immunologic Injury in Renal Allograft Recipients with De Novo Proteinuria

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    Post-transplant proteinuria is a common complication after renal transplantation; it is associated with reduced graft and recipient survival. However, the prevalence of histological causes has been reported with considerable variation. A clinico-pathological re-evaluation of post-transplant proteinuria is necessary, especially after dismissal of the term “chronic allograft nephropathy,” which had been considered to be an important cause of proteinuria. Moreover, urinary protein can promote interstitial inflammation in native kidney, whether this occurs in renal allograft remains unknown. Factors that affect the graft outcome in patients with proteinuria also remain unclear. Here we collected 98 cases of renal allograft recipients who developed proteinuria after transplant, histological features were characterized using Banff scoring system. Cox proportional hazard regression models were used for graft survival predictors. We found that transplant glomerulopathy was the leading (40.8%) cause of post-transplant proteinuria. Immunological causes, including transplant glomerulopathy, acute rejection, and chronic rejection accounted for the majority of all pathological causes of proteinuria. Nevertheless, almost all patients that developed proteinuria had immunological lesions in the graft, especially for interstitial inflammation. Intraglomerular C3 deposition was unexpectedly correlated with the severity of proteinuria. Moreover, the severity of interstitial inflammation was an independent risk factor for graft loss, while high level of hemoglobin was a protective factor for graft survival. This study revealed a predominance of immunological parameters in renal allografts with post-transplant proteinuria. These parameters not only correlate with the severity of proteinuria, but also with the outcome of the graft

    Experimental and theoretical study on minimum achievable foil thickness during asymmetric rolling

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    Parts produced by microforming are becoming ever smaller. Similarly, the foils required in micro-machines are becoming ever thinner. The asymmetric rolling technique is capable of producing foils that are thinner than those produced by the conventional rolling technique. The difference between asymmetric rolling and conventional rolling is the \u27cross-shear\u27 zone. However, the influence of the cross-shear zone on the minimum achievable foil thickness during asymmetric rolling is still uncertain. In this paper, we report experiments designed to understand this critical influencing factor on the minimum achievable thickness in asymmetric rolling. Results showed that the minimum achievable thickness of rolled foils produced by asymmetric rolling with a rolling speed ratio of 1.3 can be reduced to about 30% of that possible by conventional rolling technique. Furthermore, the minimum achievable thickness during asymmetric rolling could be correlated to the cross-shear ratio, which, in turn, could be related to the rolling speed ratio. From the experimental results, a formula to calculate the minimum achievable thickness was established, considering the parameters cross-shear ratio, friction coefficient, work roll radius, etc. in asymmetric rolling

    Size Effect on Mechanical Properties and Texture of Pure Copper Foil by Cold Rolling

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    To study the size effect on the properties of copper, tensile tests were performed with pure copper foil (thickness range from 25 μm to 300 μm) by cold rolling. A pronounced size effect was observed at a thickness of 76 μm. The results showed that ultimate strength increased as sample thickness decreased from 300 μm to 100 μm, however, this was decreased as the thickness changed from 76 μm to 25 μm with ultrahigh strain, with the same trend of dislocation density and micro stain. The rolling texture were consisted of copper {112}<111>, brass {011}<211>, and S {123}<634>. These features seemed to be linked to the increase of fraction of surface grain to volume, which led to lower districting on the dislocation slip

    Low-cost carbon nanospheres for efficient removal of organic dyes from aqueous solutions

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    Colloidal carbon nanospheres (CNS) with rich surface functional groups of −OH and −COO– were prepared from glucose solution via hydrothermal reaction and activated by NaOH solution. The nonporous CNS exhibited excellent adsorption performance toward basic dyes. High maximum adsorption capacities were obtained at 682 mg g–1 for Methylene blue, 395 mg g–1 for Methyl violet 2B, and 310 mg g–1 for Malachite green. Methylene blue with an initial concentration of 94 mg L–1 can be completely removed in 5 min at a dosage of 0.5 g L–1. This can be associated with the low mass transfer resistance due to the nonporous structure and the abundant surface active sites. The adsorption process is chemisorption in nature, while the kinetic data were well fitted to pseudosecond-order kinetic model. This material presented excellent adsorption capacities toward basic dyes with maximum adsorption capacity of 682 mg g–1 for Methylene blue B, 310 mg g–1 for Malachite green, and 395 mg g–1 for Methyl violet 2B. Furthermore, the dye saturated CNS was regenerated using an advanced oxidation method using Co2+ in aqueous solution as a homogeneous catalyst. After seven recycle runs, there was still 96% of adsorption capacity retained. The low-cost CNS nanomaterial has the potential to be applied as a new type of efficient adsorbent for water treatment

    Picking transplant glomerulopathy out of the CAN: evidence from a clinico-pathological evaluation

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    Abstract Background Since the term chronic allograft nephropathy (CAN) was removed from the Banff scheme in 2005, transplant glomerulopathy (TG) has been regarded as a clinicopathological entity that is one of the major causes of graft loss. To assess the distinction between CAN and TG, we performed a comprehensive evaluation comparing TG with traditional CAN. Methods We compared the clinicopathological features of 43 cases of TG with 43 matched cases of non-TG CAN (non-TG group) after renal transplantation. TG was diagnosed by light microscopy based on the double contours of the glomerular basement membranes, and the Banff 97 classification system was used to score TG severity (cg0-3). Results Compared to the control group, we found a significantly higher incidence of positivity for human leukocyte antigen class-I and II antibodies, a higher incidence of hepatitis C virus (HCV) infection, and poorer graft survival in TG patients. Clinically, TG was associated with a higher prevalence of proteinuria, hematuria, anaemia and hypoalbuminemia. Histologically, TG strongly correlated with antibody related microcirculatory injuries, including glomerulitis, peritubular capillaritis and peritubular capillary (PTC) C4d deposition. Interestingly, the TG patients showed a significantly higher incidence of IgA deposition than the control patients. C4d-positive TG was correlated with higher TG and PTC scores, and PTC C4d deposition was correlated with a more rapid progression to graft dysfunction. TG accompanied by HCV infection was associated with heavier proteinuria, higher TG and C4d scores, and poorer graft survival. Conclusions TG presents clinicopathological features that are distinct from non-TG cases and leads to poorer outcomes. PTC C4d deposition is related to a more rapid progression to graft loss, suggesting ongoing antibody reactivity. HCV-positive TG is a more severe sub-entity, that requires further investigation.</p

    A New Cross-Platform Instrument for Microstructure Turbulence Measurements

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    This study developed a new cross-platform instrument for microstructure turbulence measurement (CPMTM) and evaluated its performance. The CPMTM is designed as an “all-in-one” payload that can be easily integrated with a variety of marine instrumentation platforms. The sensors in the CPMTM include two shear probes, a fast-response temperature probe, and an accelerometer for monitoring vibrations. In addition, a custom-designed flexible connection vibration-damping device is used to isolate platform vibrations. To validate the CPMTM performance, a direct comparison was carried out with a reference acoustic Doppler velocimeter in a controlled flume for four background turbulence levels. The results of the comparison show that the velocity spectra measured by the CPMTM and ADV w components are in agreement, which demonstrates the ability of the CPMTM to acquire accurate turbulence data. Furthermore, the CPMTM was integrated into the long-range Sea-Whale 2000 AUV and tested in the northern South China Sea in September 2020. The data collected by the CPMTM show that the measured shear spectrum of the noise reduction agrees well with the empirical Nasmyth spectrum. Turbulent kinetic energy dissipation rates as low as 7 × 10−10 W kg−1 can be resolved. Laboratory and field experiments illustrate that the CPMTM has an extraordinarily low noise level and is validated for turbulence measurements
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