2,484 research outputs found

    Composite Correlation Quantization for Efficient Multimodal Retrieval

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    Efficient similarity retrieval from large-scale multimodal database is pervasive in modern search engines and social networks. To support queries across content modalities, the system should enable cross-modal correlation and computation-efficient indexing. While hashing methods have shown great potential in achieving this goal, current attempts generally fail to learn isomorphic hash codes in a seamless scheme, that is, they embed multiple modalities in a continuous isomorphic space and separately threshold embeddings into binary codes, which incurs substantial loss of retrieval accuracy. In this paper, we approach seamless multimodal hashing by proposing a novel Composite Correlation Quantization (CCQ) model. Specifically, CCQ jointly finds correlation-maximal mappings that transform different modalities into isomorphic latent space, and learns composite quantizers that convert the isomorphic latent features into compact binary codes. An optimization framework is devised to preserve both intra-modal similarity and inter-modal correlation through minimizing both reconstruction and quantization errors, which can be trained from both paired and partially paired data in linear time. A comprehensive set of experiments clearly show the superior effectiveness and efficiency of CCQ against the state of the art hashing methods for both unimodal and cross-modal retrieval

    Tidal capture of an asteroid by a magnetar: FRB-like bursts, glitch and anti-glitch

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    Recently, remarkable anti-glitch and glitch accompanied by bright radio bursts of the Galactic magnetar SGR J1935+2154 were discovered. These two infrequent temporal coincidences between the glitch/anti-glitch and the fast radio burst (FRB)-like bursts reveal their physical connection of them. Here we propose that the anti-glitch/glitch and FRB-like bursts can be well understood by an asteroid tidally captured by a magnetar. In this model, an asteroid is tidally captured and disrupted by a magnetar. Then, the disrupted asteroid will transfer the angular momentum to the magnetar producing a sudden change in the magnetar rotational frequency at the magnetosphere radius. If the orbital angular momentum of the asteroid is parallel (or anti-parallel) to that of the spinning magnetar, a glitch (or anti-glitch) will occur. Subsequently, the bound asteroid materials fall back to the pericenter and eventually are accreted to the surface of the magnetar. Massive fragments of the asteroid cross magnetic field lines and produce bright radio bursts through coherent curvature radiation. Our model can explain the sudden magnetar spin changes and FRB-like bursts in a unified way.Comment: 6 pages, 1 figure, published by MNRAS https://doi.org/10.1093/mnras/stad158

    Anti-tumor activity of triterpenoid-rich extract from bamboo shavings (Caulis bamfusae in Taeniam)

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    Bamboo shavings are a kind of Chinese traditional medicine, which have been certificated as a material of functional food by the Ministry of Health in China. The anti-tumor activities of a triterpenoid-rich extract of bamboo shavings (EBS) and its main component, friedelin were evaluated in the present study. It was proved that EBS could inhibit the growth of P388 and A549 cancer cell lines effectively by SRB and MTT assay. Meanwhile, EBS had notable inhibitory effect on the sarcoma-loaded mice S180 model, which led to a depressed trend of tumor weight, compared to cyclophosphamide. Furthermore, the anti-tumor activity of friedelin monomer, a main triterpenoid separated from EBS, was tested by MTT assay and results showed that friedelin displayed rather strong anti-tumor activities on the proliferation of four cancer lines, A375, L929, Hela and THP-1, with a time-dose relationship compared to de-methylcantharidin, respectively. Therefore, it is suggested that EBS has a great potential to be applied in functional food for its anti-tumor activity, in which friedelin was one of the most important active factors.Key words: Extract of bamboo shavings, anti-tumor, friedelin, triterpenoid (Caulis bamfusae in Taeniam)

    The separability of tripartite Gaussian state with amplification and amplitude damping

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    Tripartite three mode Gaussian state undergoes parametric amplification and amplitude damping as well as thermal noise is studied. In the case of a state totally symmetrically interacting with the environment, the time dependent correlation matrix of the state in evolution is given. The conditions for fully separability and fully entanglement of the final tripartite three mode Gaussian state are worked out.Comment: 9 pages, 3 figure

    Experimental Decoy Quantum Key Distribution Up To 130KM Fiber

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    Decoy State Quantum Key Distribution (QKD), being capable of beating PNS attack and uncon- ditionally secure, have become an attractive one recently. But, in many QKD systems, disturbances of transmission channel make quantum bit error rate (QBER) increase which limits both security distance and key bit rate of real-life decoy state QKD systems. We demonstrate the two-intensity decoy QKD with one-way Faraday-Michelson phase modulation system, which is free of channel dis- turbance and keeps interference fringe visibility (99%) long period, near 130KM single mode optical fiber in telecom (1550 nm) wavelength. This is longest distance fiber decoy state QKD system based on two intensity protocol.Comment: 4 pages, 2figure

    The Effects of the interfacial Pseudo-spin Coupling Fluctuation on the Dielectric Property of a Ferroelectric Superlattice

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    Using effective-field theory with correlations, we investigate the effects of interfacial pseudo-spin coupling fluctuations on the susceptibility and polarization of ferroelectric superlattices within the framework of transverse Ising model. It is found that the interfacial coupling fluctuations increase the susceptibility in the low temperature region. For a strong interfacial coupling, the phase transition temperature decreases with the strength of fluctuations of the interfacial coupling. The dependence of the susceptibility on the superlattice period of BaTiO3/SrTiO3BaTiO_{3}/SrTiO_{3} are plotted for different interfacial coupling fluctuations strength. At room temperature, when the interfacial coupling fluctuation increases, the peak position of the susceptibility will shift to a large superlattice period.Comment: 14 pages, 5 figures, RevTex

    Redactable Signatures for Signed CDA Documents

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    [[abstract]]The Clinical Document Architecture, introduced by Health Level Seven, is a XML-based standard intending to specify the encoding, structure, and semantics of clinical documents for exchange. Since the clinical document is in XML form, its authenticity and integrity could be guaranteed by the use of the XML signature published by W3C. While a clinical document wants to conceal some personal or private information, the document needs to be redacted. It makes the signed signature of the original clinical document not be verified. The redactable signature is thus proposed to enable verification for the redacted document. Only a little research does the implementation of the redactable signature, and there still not exists an appropriate scheme for the clinical document. This paper will investigate the existing web-technologies and find a compact and applicable model to implement a suitable redactable signature for the clinical document viewer.[[notice]]補正完畢[[incitationindex]]SC
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