368 research outputs found
Interpretation on Multi-modal Visual Fusion
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
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
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
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
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
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
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 -dimensional hydrogenic and
oscillator-like systems, respectively, in the pseudoclassical ()
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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