6,561 research outputs found
Spin-Cherenkov effect in a magnetic nanostrip with interfacial Dzyaloshinskii-Moriya interaction
Spin-Cherenkov effect enables strong excitations of spin waves (SWs) with
nonlinear wave dispersions. The Dzyaloshinskii-Moriya interaction (DMI) results
in anisotropy and nonreciprocity of SWs propagation. In this work, we study the
effect of the interfacial DMI on SW Cherenkov excitations in permalloy
thin-film strips within the framework of micromagnetism. By performing
micromagnetic simulations, it is shown that coherent SWs are excited when the
velocity of a moving magnetic source exceeds the propagation velocity of the
SWs. Moreover, the threshold velocity of the moving magnetic source with finite
DMI can be reduced compared to the case of zero DMI. It thereby provides a
promising route towards efficient SW generation and propagation, with potential
applications in spintronic and magnonic devices.Comment: 6 pages, 5 figures. To be published in Scientific Report
Experimental Effects and Individual Differences in Linear Mixed Models: Estimating the Relationship between Spatial, Object, and Attraction Effects in Visual Attention
Linear mixed models (LMMs) provide a still underused methodological perspective on combining experimental and individual-differences research. Here we illustrate this approach with two-rectangle cueing in visual attention (Egly et al., 1994). We replicated previous experimental cue-validity effects relating to a spatial shift of attention within an object (spatial effect), to attention switch between objects (object effect), and to the attraction of attention toward the display centroid (attraction effect), also taking into account the design-inherent imbalance of valid and other trials. We simultaneously estimated variance/covariance components of subject-related random effects for these spatial, object, and attraction effects in addition to their mean reaction times (RTs). The spatial effect showed a strong positive correlation with mean RT and a strong negative correlation with the attraction effect. The analysis of individual differences suggests that slow subjects engage attention more strongly at the cued location than fast subjects. We compare this joint LMM analysis of experimental effects and associated subject-related variances and correlations with two frequently used alternative statistical procedures
FRACTURE PARAMETERS EVALUATION FOR THE CRACKED NONHOMOGENEOUS ENAMEL BASED ON THE FINITE ELEMENT METHOD AND VIRTUAL CRACK CLOSURE TECHNIQUE
To accurately solve the fracture parameters of enamel, we have established computational nonhomogeneous enamel models and constructed the fracture element of enamel dumb nodes, based on the enamel mineral concentration, nonhomogeneous mechanical properties, and virtual crack closure technique. Through the commercial finite element software ABAQUS and the fracture element of the enamel dumb nodes, we have established the user subroutines UMAT and UEL, which enabled solving of the energy release rates of the nonhomogeneous enamel structure with cracks. The stress intensity factors of central cracks, three-point bend and compact stretched enamels, and double-edge notched stretched enamels are determined. By comparing them with analytical solutions, we have proved that the fracture element of the enamel dumb nodes is highly accurate, simple, and convenient. In addition, the cracks can be other elements rather than singular or special elements; they show versatility and other advantages. The stress intensity factor of the dental enamel can be solved more realistically. Thus, a new numerical method for prevention and treatment of dental diseases is provided
MDTv2: Masked Diffusion Transformer is a Strong Image Synthesizer
Despite its success in image synthesis, we observe that diffusion
probabilistic models (DPMs) often lack contextual reasoning ability to learn
the relations among object parts in an image, leading to a slow learning
process. To solve this issue, we propose a Masked Diffusion Transformer (MDT)
that introduces a mask latent modeling scheme to explicitly enhance the DPMs'
ability to contextual relation learning among object semantic parts in an
image. During training, MDT operates in the latent space to mask certain
tokens. Then, an asymmetric diffusion transformer is designed to predict masked
tokens from unmasked ones while maintaining the diffusion generation process.
Our MDT can reconstruct the full information of an image from its incomplete
contextual input, thus enabling it to learn the associated relations among
image tokens. We further improve MDT with a more efficient macro network
structure and training strategy, named MDTv2. Experimental results show that
MDTv2 achieves superior image synthesis performance, e.g., a new SOTA FID score
of 1.58 on the ImageNet dataset, and has more than 10x faster learning speed
than the previous SOTA DiT. The source code is released at
https://github.com/sail-sg/MDT.Comment: Extension of ICCV 2023 work, source code:
https://github.com/sail-sg/MD
Table-to-Text: Describing Table Region with Natural Language
In this paper, we present a generative model to generate a natural language
sentence describing a table region, e.g., a row. The model maps a row from a
table to a continuous vector and then generates a natural language sentence by
leveraging the semantics of a table. To deal with rare words appearing in a
table, we develop a flexible copying mechanism that selectively replicates
contents from the table in the output sequence. Extensive experiments
demonstrate the accuracy of the model and the power of the copying mechanism.
On two synthetic datasets, WIKIBIO and SIMPLEQUESTIONS, our model improves the
current state-of-the-art BLEU-4 score from 34.70 to 40.26 and from 33.32 to
39.12, respectively. Furthermore, we introduce an open-domain dataset
WIKITABLETEXT including 13,318 explanatory sentences for 4,962 tables. Our
model achieves a BLEU-4 score of 38.23, which outperforms template based and
language model based approaches.Comment: 9 pages, 4 figures. This paper has been published by AAAI201
Individual position diversity in dependence socioeconomic networks increases economic output
The availability of big data recorded from massively multiplayer online
role-playing games (MMORPGs) allows us to gain a deeper understanding of the
potential connection between individuals' network positions and their economic
outputs. We use a statistical filtering method to construct dependence networks
from weighted friendship networks of individuals. We investigate the 30
distinct motif positions in the 13 directed triadic motifs which represent
microscopic dependences among individuals. Based on the structural similarity
of motif positions, we further classify individuals into different groups. The
node position diversity of individuals is found to be positively correlated
with their economic outputs. We also find that the economic outputs of leaf
nodes are significantly lower than that of the other nodes in the same motif.
Our findings shed light on understanding the influence of network structure on
economic activities and outputs in socioeconomic system.Comment: 19 pages, 5 figure
- …