368 research outputs found

    Interpretation on Multi-modal Visual Fusion

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    In this paper, we present an analytical framework and a novel metric to shed light on the interpretation of the multimodal vision community. Our approach involves measuring the proposed semantic variance and feature similarity across modalities and levels, and conducting semantic and quantitative analyses through comprehensive experiments. Specifically, we investigate the consistency and speciality of representations across modalities, evolution rules within each modality, and the collaboration logic used when optimizing a multi-modality model. Our studies reveal several important findings, such as the discrepancy in cross-modal features and the hybrid multi-modal cooperation rule, which highlights consistency and speciality simultaneously for complementary inference. Through our dissection and findings on multi-modal fusion, we facilitate a rethinking of the reasonability and necessity of popular multi-modal vision fusion strategies. Furthermore, our work lays the foundation for designing a trustworthy and universal multi-modal fusion model for a variety of tasks in the future.Comment: This version was under review since 2023/3/

    Correlation-induced phase transitions and mobility edges in an interacting non-Hermitian quasicrystal

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    Non-Hermitian quasicrystal constitutes a unique class of disordered open system with PT-symmetry breaking, localization and topological triple phase transitions. In this work, we uncover the effect of quantum correlation on phase transitions and entanglement dynamics in non-Hermitian quasicrystals. Focusing on two interacting bosons in a Bose-Hubbard lattice with quasiperiodically modulated gain and loss, we find that the onsite interaction between bosons could drag the PT and localization transition thresholds towards weaker disorder regions compared with the noninteracting case. Moreover, the interaction facilitates the expansion of the critical point of a triple phase transition in the noninteracting system into a critical phase with mobility edges, whose domain could be flexibly controlled by tuning the interaction strength. Systematic analyses of the spectrum, inverse participation ratio, topological winding number, wavepacket dynamics and entanglement entropy lead to consistent predictions about the correlation-driven phases and transitions in our system. Our findings pave the way for further studies of the interplay between disorder and interaction in non-Hermitian quantum matter.Comment: 18 pages, 13 figures, revised versio

    SpatialRank: Urban Event Ranking with NDCG Optimization on Spatiotemporal Data

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    The problem of urban event ranking aims at predicting the top-k most risky locations of future events such as traffic accidents and crimes. This problem is of fundamental importance to public safety and urban administration especially when limited resources are available. The problem is, however, challenging due to complex and dynamic spatio-temporal correlations between locations, uneven distribution of urban events in space, and the difficulty to correctly rank nearby locations with similar features. Prior works on event forecasting mostly aim at accurately predicting the actual risk score or counts of events for all the locations. Rankings obtained as such usually have low quality due to prediction errors. Learning-to-rank methods directly optimize measures such as Normalized Discounted Cumulative Gain (NDCG), but cannot handle the spatiotemporal autocorrelation existing among locations. In this paper, we bridge the gap by proposing a novel spatial event ranking approach named SpatialRank. SpatialRank features adaptive graph convolution layers that dynamically learn the spatiotemporal dependencies across locations from data. In addition, the model optimizes through surrogates a hybrid NDCG loss with a spatial component to better rank neighboring spatial locations. We design an importance-sampling with a spatial filtering algorithm to effectively evaluate the loss during training. Comprehensive experiments on three real-world datasets demonstrate that SpatialRank can effectively identify the top riskiest locations of crimes and traffic accidents and outperform state-of-art methods in terms of NDCG by up to 12.7%.Comment: 37th Conference on Neural Information Processing Systems (NeurIPS 2023

    A New Species of Gracixalus (Anura: Rhacophoridae) from West Guangxi, China

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    We discovered a new species of the genus Gracixalus, Gracixalus tianlinensis sp. nov. which is morphologically almost similar to G. jinggangensis, G. jinxiuensis and G. sapaensis, but is distinguished from these species and all other rhacophorids in China and adjoining countries by a combination of the following characters: (1) SVL 30.3-35.9 mm in male, 35.6-38.7 mm in female, (2) head length less than head width, (3) vomerine teeth absent, (4) supratympanic fold distinct, (5) axilla and posterior surface of flanks pale yellow, (6) nuptial pads distinct on Finger I and slightly visible on Finger II, (7) dorsum brown to beige, with an inverse Y-shaped dark brown marking, (8) single subgular vocal sac. Our preliminary phylogenetic analyses implied G. tianlinensis sp. nov. is sister to G. sapaensis with well-supported values. Currently, this new species is known to be distributed in montane evergreen forests in association with montane bamboo in Cenwanglaoshan National Nature Reserve, Tianlin County, Guangxi, China

    Fusarium Graminearum Growth Inhibition Due to Glucose Starvation Caused by Osthol

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    The effects of osthol, a plant coumarin, on morphology, sugar uptake and cell wall components of Fusarium graminearum were examined in vitro by electron microscopy,14C-labelling and enzyme activity detection. The results revealed that osthol could inhibit the hypha growth of F. graminearum by decreasing hyphal absorption to reducing sugar. After treatment with 100 μg·mL−1 osthol for 24 h, many hyphal fragments of F. graminearum appeared. Microscopy observation showed that the cell walls of hyphal fragments blurred and the organelles of the cells degraded with the increasing vacuoles. The N-acetyl-D-glucosamine contents and chitinase activity both increased when hypha were treated with 100 μg·mL−1 osthol, whereas the activity of β-1,6-glucanase remained unchanged. When F. graminearum fed with 14C glucose was treated with 100 μg·mL−1osthol, glucose contents decreased to the lowest level, while the contents in non-osthol treated controls remained unchanged. These results suggested that chitinase activity might be related to glucose starvation under osthol treatment, and that the appearance of hyphae fragments maybe the results of the promoted chitinase activity which itself triggered chitin degradation

    Exact new mobility edges between critical and localized states

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    The disorder systems host three types of fundamental quantum states, known as the extended, localized, and critical states, of which the critical states remain being much less explored. Here we propose a class of exactly solvable models which host a novel type of exact mobility edges (MEs) separating localized states from robust critical states, and propose experimental realization. Here the robustness refers to the stability against both single-particle perturbation and interactions in the few-body regime. The exactly solvable one-dimensional models are featured by quasiperiodic mosaic type of both hopping terms and on-site potentials. The analytic results enable us to unambiguously obtain the critical states which otherwise require arduous numerical verification including the careful finite size scalings. The critical states and new MEs are shown to be robust, illustrating a generic mechanism unveiled here that the critical states are protected by zeros of quasiperiodic hopping terms in the thermodynamic limit. Further, we propose a novel experimental scheme to realize the exactly solvable model and the new MEs in an incommensurate Rydberg Raman superarray. This work may pave a way to precisely explore the critical states and new ME physics with experimental feasibility.Comment: 5+6 pages, 4+5 figures. Discussions are updated. Under second round of revie

    Complexity measures and uncertainty relations of the high-dimensional harmonic and hydrogenic systems

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    In this work we find that not only the Heisenberg-like uncertainty products and the R\'enyi-entropy-based uncertainty sum have the same first-order values for all the quantum states of the DD-dimensional hydrogenic and oscillator-like systems, respectively, in the pseudoclassical (D→∞D \to \infty) limit but a similar phenomenon also happens for both the Fisher-information-based uncertainty product and the Shannon-entropy-based uncertainty sum, as well as for the Cr\'amer-Rao and Fisher-Shannon complexities. Moreover, we show that the LMC (L\'opez-Ruiz-Mancini-Calvet) and LMC-R\'enyi complexity measures capture the hydrogenic-harmonic difference in the high dimensional limit already at first order
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