51 research outputs found

    Traitor Tracing with N^(1/3)-size Ciphertexts and O(1)-size Keys from k-Lin

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    We present a pairing-based traitor tracing scheme for NN users with∣pk∣=∣ct∣=O(N1/3),∣sk∣=O(1). |\mathsf{pk}| = |\mathsf{ct}| = O(N^{1/3}), \quad |\mathsf{sk}| = O(1). This is the first pairing-based scheme to achieve ∣pk∣⋅∣sk∣⋅∣ct∣=o(N){|\mathsf{pk}|\cdot|\mathsf{sk}|\cdot|\mathsf{ct}|=o(N)}. Our construction relies on the (bilateral) kk-Lin assumption, and achieves private tracing and full collusion resistance. Our result simultaneously improves upon the sizes of pk,ct\mathsf{pk},\mathsf{ct} in Boneh–Sahai–Waters [Eurocrypt \u2706] and the size of sk\mathsf{sk} in Zhandry [Crypto \u2720], while further eliminating the reliance on the generic group model in the latter work

    MAST: Video Polyp Segmentation with a Mixture-Attention Siamese Transformer

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    Accurate segmentation of polyps from colonoscopy videos is of great significance to polyp treatment and early prevention of colorectal cancer. However, it is challenging due to the difficulties associated with modelling long-range spatio-temporal relationships within a colonoscopy video. In this paper, we address this challenging task with a novel Mixture-Attention Siamese Transformer (MAST), which explicitly models the long-range spatio-temporal relationships with a mixture-attention mechanism for accurate polyp segmentation. Specifically, we first construct a Siamese transformer architecture to jointly encode paired video frames for their feature representations. We then design a mixture-attention module to exploit the intra-frame and inter-frame correlations, enhancing the features with rich spatio-temporal relationships. Finally, the enhanced features are fed to two parallel decoders for predicting the segmentation maps. To the best of our knowledge, our MAST is the first transformer model dedicated to video polyp segmentation. Extensive experiments on the large-scale SUN-SEG benchmark demonstrate the superior performance of MAST in comparison with the cutting-edge competitors. Our code is publicly available at https://github.com/Junqing-Yang/MAST

    Optically induced charge-transfer in donor-acceptor-substituted p- and m- C2B10H12 carboranes

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    Icosahedral carboranes, C2B10H12, have long been considered to be aromatic but the extent of conjugation between these clusters and their substituents is still being debated. m- and p-Carboranes are compared with m- and p-phenylenes as conjugated bridges in optical functional chromophores with a donor and an acceptor as substituents here. The absorption and fluorescence data for both carboranes from experimental techniques (including femtosecond transient absorption, time-resolved fluorescence and broadband fluorescence upconversion) show that the absorption and emission processes involve strong intramolecular charge transfer between the donor and acceptor substituents via the carborane cluster. From quantum chemical calculations on these carborane systems, the charge transfer process depends on the relative torsional angles of the donor and acceptor groups where an overlap between the two frontier orbitals exists in the bridging carborane cluster

    Agarose-Alumina Composite Supported Palladium Catalyst for Suzuki Coupling Reactions

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    The palladium catalyst supported on agarose-alumina composite and its utilization in the Suzuki reaction have been investigated. The agarose-alumina composite was prepared and modified with organofunctional groups by reacting with the coupling reagent 3-aminopropyltriethoxysilane (APTES) through Al−O−Si bonds. Palladium was efficiently loaded on the composite by the amino groups. The Suzuki coupling reaction can proceed successfully at room temperature under air. High yields of various aryl-aryl products have been obtained. Recycling studies have shown that the catalyst can be easily recovered and reused several times. The yields decreased from 95% to 85% in five cycles

    Bearing Fault Diagnosis in the Mixed Domain Based on Crossover-Mutation Chaotic Particle Swarm

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    The classification frameworks for fault diagnosis of rolling element bearings in rotating machinery are mostly based on analysis in a single time-frequency domain, where sensitive features are not completely extracted. To solve this problem, a new fault diagnosis technique is proposed in the mixed domain, based on the crossover-mutation chaotic particle swarm optimization support vector machine. Firstly, fault features are generated using techniques in the time domain, the frequency domain, and the time-frequency domain. Secondly, the weighted maximum relevance minimum redundancy (WMRMR) algorithm is adopted to reduce the dimension of the feature set and to establish the representative feature set. Thirdly, a new crossover-mutation strategy is suggested to reduce the local minima in optimization, and an optimization disturbance is added. Finally, the support vector machine is optimized using the improved chaotic particle swarm to improve fault classification diagnosis. The effectiveness of the proposed new bearing fault diagnostic technique is verified by experimental tests under different bearing conditions. Test results showed that the bearing fault classification accuracy of CMCPSO-SVM in the mixed domain was much higher than those in a single feature domain

    Gender Difference in the Association of Early- vs. Late-Onset Type 2 Diabetes with Non-Fatal Microvascular Disease in China: A Cross-sectional Study

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    BackgroundThis study aimed to test whether early-onset (defined as <40 years of age) type 2 diabetes mellitus (T2DM) imparted different risks of microvascular disease to Chinese men and women.Methods222,537 Chinese patients with T2DM were recruited in 630 hospitals from 106 cities in 30 provinces of China in 2012 using a cross-sectional design. Logistic regression analysis was performed to obtain odds ratios (ORs) of male vs. female for diabetic retinopathy (DR) and diabetic nephropathy (DN). Additive interaction was used to test whether male gender and early-onset T2DM had interactive effects for DR and DN.ResultsMore men than women with T2DM had DN (4.5 vs. 3.0%, P < 0.0001), DR (5.3 vs. 5.1%, P < 0.0001), and microvascular disease (either DN or DR) (8.4 vs. 7.1%, P < 0.0001). After adjustment for age and levels of hospitals, the effect sizes of early-onset T2DM for microvascular disease were higher in men than in women, with a 2.67 [95% confidence intervals (CI): 2.51–2.85] fold risk in men and a 2.53 (95% CI: 2.35–2.72) fold risk in women. The risk effect sizes were greatly attenuated by further adjusting for diabetes durations and other traditional risk factors, with a 1.28 (95% CI: 1.19–1.37) fold risk in men and a 1.07 (95% CI: 0.99–1.16) fold risk in women. After adjustment for diabetes durations and other traditional risk factors, using women with late-onset T2DM as the reference, co-presence of early-onset and male gender significantly enhanced the ORs of either early-onset alone (1.10, 95% CI: 1.03–1.19) or male gender alone (0.96, 95% CI: 0.93–0.99) to 1.32 (95% CI: 1.24–1.41), with significant additive interaction. Kaplan–Meier analysis showed that in early-onset T2DM, DN developed 5 years earlier in men than in women.ConclusionEarly-onset T2DM increased more risk of microvascular complications in Chinese men than in women, most of increased risks being attributable to longer diabetes durations
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