1,004 research outputs found

    Unsupervised Multi-Criteria Adversarial Detection in Deep Image Retrieval

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    The vulnerability in the algorithm supply chain of deep learning has imposed new challenges to image retrieval systems in the downstream. Among a variety of techniques, deep hashing is gaining popularity. As it inherits the algorithmic backend from deep learning, a handful of attacks are recently proposed to disrupt normal image retrieval. Unfortunately, the defense strategies in softmax classification are not readily available to be applied in the image retrieval domain. In this paper, we propose an efficient and unsupervised scheme to identify unique adversarial behaviors in the hamming space. In particular, we design three criteria from the perspectives of hamming distance, quantization loss and denoising to defend against both untargeted and targeted attacks, which collectively limit the adversarial space. The extensive experiments on four datasets demonstrate 2-23% improvements of detection rates with minimum computational overhead for real-time image queries

    SBVLC:Secure Barcode-based Visible Light Communication for Smartphones

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    2D barcodes have enjoyed a significant penetration rate in mobile applications. This is largely due to the extremely low barrier to adoption – almost every camera-enabled smartphone can scan 2D barcodes. As an alternative to NFC technology, 2D barcodes have been increasingly used for security-sensitive mobile applications including mobile payments and personal identification. However, the security of barcode-based communication in mobile applications has not been systematically studied. Due to the visual nature, 2D barcodes are subject to eavesdropping when they are displayed on the smartphone screens. On the other hand, the fundamental design principles of 2D barcodes make it difficult to add security features. In this paper, we propose SBVLC - a secure system for barcode-based visible light communication (VLC) between smartphones. We formally analyze the security of SBVLC based on geometric models and propose physical security enhancement mechanisms for barcode communication by manipulating screen view angles and leveraging user-induced motions. We then develop three secure data exchange schemes that encode information in barcode streams. These schemes are useful in many security-sensitive mobile applications including private information sharing, secure device pairing, and contactless payment. SBVLC is evaluated through extensive experiments on both Android and iOS smartphones

    (E)-2-(4-Diethyl­amino-2-hydroxy­benzyl­idene­amino)benzonitrile

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    The mol­ecule of the title compound, C18H19N3O, displays a trans configuration with respect to the C=N double bond. The dihedral angle between the planes of the two benzene rings is 2.62 (11)°. A strong intra­molecular O—H⋯N hydrogen bond stabilizes the mol­ecular conformation

    Comparison of serum apolipoprotein A-I between Chinese multiple sclerosis and other related autoimmune disease

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    <p>Abstract</p> <p>Background</p> <p>Serum apolipoprotein (apo) A-I was considered to be an immune regulator and could suppress pro-inflammatory cytokines generated by activated T cell in some autoimmune diseases. However, the change of serum apoA-I levels in multiple sclerosis (MS) patients is unknown.</p> <p>Methods</p> <p>In the presentation we performed a study on serum apoA-I levels in the patients with MS. We enrolled some age and gender matched patients with MS, autoimmune demyelinating diseases (Guillain-Barre Syndrome and Clinically Isolated Syndrome), neuroinflammatory diseases (viral encephalitis), autoimmune connective diseases (rheumatoid arthritis and systemic lupus erythematosus) and healthy control groups, and tested their serum lipids levels: total cholesterol (TC), triglyceride (TG), high-density lipoproteins (HDL), apolipoproteinB100 (apoB100), apolipoproteinA-I (apoA-I).</p> <p>Results</p> <p>For all patients, age had no effect on serum apoA-I levels (<it>P </it>> 0.05). Meanwhile, we proved the highest serum apoA-I levels in MS patients and the lowest serum apoA-I levels in SLE patients. Serum apoA-I levels was significantly elevated in female MS patients (P = 0.033; P < 0.05).</p> <p>Conclusion</p> <p>In short we believed that patients with MS and other autoimmune demyelination had significantly decreased serum levels of apo A-I.</p

    Gap Anisotropy in Iron-Based Superconductors: A Point-Contact Andreev Reflection Study of BaFe2−x_{2-x}Nix_{x}As2_2 Single Crystals

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    We report a systematic investigation on c-axis point-contact Andreev reflection (PCAR) in BaFe2−x_{2-x}Nix_xAs2_2 superconducting single crystals from underdoped to overdoped regions (0.075 ≤x≤0.15\leq x\leq 0.15). At optimal doping (x=0.1x=0.1) the PCAR spectrum feature the structures of two superconducting gap and electron-boson coupling mode. In the s±s\pm scenario, quantitative analysis using a generalized Blonder-Tinkham-Klapwijk (BTK) formalism with two gaps: one isotropic and another angle dependent, suggest a nodeless state in strong-coupling limit with gap minima on the Fermi surfaces. Upon crossing above the optimal doping (x>0.1x > 0.1), the PCAR spectrum show an in-gap sharp narrow peak at low bias, in contrast to the case of underdoped samples (x<0.1x < 0.1), signaling the onset of deepened gap minima or nodes in the superconducting gap. This result provides evidence of the modulation of the gap amplitude with doping concentration, consistent with the calculations for the orbital dependent pair interaction mediated by the antiferromagnetic spin fluctuations.Comment: 5 pages, 4 figure

    Safety and clinical outcomes of regional anaesthesia in Chinese patients with non-small cell lung cancer undergoing non-intubated lobectomy

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    Purpose: To determine the safety and clinical outcomes of epidural anaesthesia (EA) relative to internal intercostal nerve block (INB) in Chinese patients with non-small cell lung cancer (NSCLC) who were undergoing non-intubated thoracoscopic lobectomy.Methods: Chinese patients with NSCLC (stage I or II) with no evidence of metastasis were given either EA or INB, with equal number of patients in both groups. The peri-operative outcomes determined were duration of anaesthesia /duration of surgery, SpO2/PaCO2 levels, cases of hypotension, and blood loss. The post-operative outcome indices measured were pain score (determined using visual analogue scale (VAS), post-operative complications, chest drainage, duration of hospital stay, and deaths/mortality.Multiple regression analysis was used to confirm the results obtained in this study by adjusting potential covariates. Peri-operative and post-operative complications were compared between the two groups. The results obtained from 220 patients were subjected to statistical analysis.Results: Peri-operative results showed that patients who underwent INB had shorter duration of anaesthesia (12.3 vs 31.4 min, p &lt; 0.05) and shorter duration of surgery (164.4 vs 197.2 min, p &lt; 0.05) than patients who underwent EA for non-intubated lobectomy. Post-operative results showed that patients who underwent INB had significantly lower number of post-operative complications than those who received EA (29 vs 44 %, p &lt; 0.05). The most common post-operative complications among patients in both treatment groups were nausea, vomiting, emphysema and pulmonary complications. Patients who underwent INB had shorter hospital stay than those who underwent EA (5.1 vs 7.5 days, p &lt; 0.05). These results were confirmed through multiple regression analysis.Conclusion: These findings favour the use of INB for regional anaesthesia in NSCLC patients undergoing non-intubated lobectomy
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