62 research outputs found
Rethink Cross-Modal Fusion in Weakly-Supervised Audio-Visual Video Parsing
Existing works on weakly-supervised audio-visual video parsing adopt hybrid
attention network (HAN) as the multi-modal embedding to capture the cross-modal
context. It embeds the audio and visual modalities with a shared network, where
the cross-attention is performed at the input. However, such an early fusion
method highly entangles the two non-fully correlated modalities and leads to
sub-optimal performance in detecting single-modality events. To deal with this
problem, we propose the messenger-guided mid-fusion transformer to reduce the
uncorrelated cross-modal context in the fusion. The messengers condense the
full cross-modal context into a compact representation to only preserve useful
cross-modal information. Furthermore, due to the fact that microphones capture
audio events from all directions, while cameras only record visual events
within a restricted field of view, there is a more frequent occurrence of
unaligned cross-modal context from audio for visual event predictions. We thus
propose cross-audio prediction consistency to suppress the impact of irrelevant
audio information on visual event prediction. Experiments consistently
illustrate the superior performance of our framework compared to existing
state-of-the-art methods.Comment: WACV 202
Generalized Few-Shot Point Cloud Segmentation Via Geometric Words
Existing fully-supervised point cloud segmentation methods suffer in the
dynamic testing environment with emerging new classes. Few-shot point cloud
segmentation algorithms address this problem by learning to adapt to new
classes at the sacrifice of segmentation accuracy for the base classes, which
severely impedes its practicality. This largely motivates us to present the
first attempt at a more practical paradigm of generalized few-shot point cloud
segmentation, which requires the model to generalize to new categories with
only a few support point clouds and simultaneously retain the capability to
segment base classes. We propose the geometric words to represent geometric
components shared between the base and novel classes, and incorporate them into
a novel geometric-aware semantic representation to facilitate better
generalization to the new classes without forgetting the old ones. Moreover, we
introduce geometric prototypes to guide the segmentation with geometric prior
knowledge. Extensive experiments on S3DIS and ScanNet consistently illustrate
the superior performance of our method over baseline methods. Our code is
available at: https://github.com/Pixie8888/GFS-3DSeg_GWs.Comment: Accepted by ICCV 202
ContraNeRF: Generalizable Neural Radiance Fields for Synthetic-to-real Novel View Synthesis via Contrastive Learning
Although many recent works have investigated generalizable NeRF-based novel
view synthesis for unseen scenes, they seldom consider the synthetic-to-real
generalization, which is desired in many practical applications. In this work,
we first investigate the effects of synthetic data in synthetic-to-real novel
view synthesis and surprisingly observe that models trained with synthetic data
tend to produce sharper but less accurate volume densities. For pixels where
the volume densities are correct, fine-grained details will be obtained.
Otherwise, severe artifacts will be produced. To maintain the advantages of
using synthetic data while avoiding its negative effects, we propose to
introduce geometry-aware contrastive learning to learn multi-view consistent
features with geometric constraints. Meanwhile, we adopt cross-view attention
to further enhance the geometry perception of features by querying features
across input views. Experiments demonstrate that under the synthetic-to-real
setting, our method can render images with higher quality and better
fine-grained details, outperforming existing generalizable novel view synthesis
methods in terms of PSNR, SSIM, and LPIPS. When trained on real data, our
method also achieves state-of-the-art results
Some conceptual difficulties regarding "net" multipliers
Multipliers are routinely used for impact evaluation of private projects and public policies at the national and subnational levels. Oosterhaven and Stelder (2002) correctly pointed out the misuse of standard 'gross' multipliers and proposed the concept of 'net' multiplier as a solution to this bad practice. We prove their proposal is not well founded. We do so by showing that supporting theorems are faulty in enunciation and demonstration. The proofs are flawed due to an analytical error but the theorems themselves cannot be salvaged as generic, non-curiosum counterexamples demonstrate. We also provide a general analytical framework for multipliers and, using it, we show that standard 'gross' multipliers are all that is needed within the interindustry model since they follow the causal logic of the economic model, are well defined and independent of exogenous shocks, and are interpretable as predictors for change
The use of hydrothermal carbonization to recycle nutrients in algal biofuel production
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/100324/1/ep11812.pd
Spintronics: Fundamentals and applications
Spintronics, or spin electronics, involves the study of active control and
manipulation of spin degrees of freedom in solid-state systems. This article
reviews the current status of this subject, including both recent advances and
well-established results. The primary focus is on the basic physical principles
underlying the generation of carrier spin polarization, spin dynamics, and
spin-polarized transport in semiconductors and metals. Spin transport differs
from charge transport in that spin is a nonconserved quantity in solids due to
spin-orbit and hyperfine coupling. The authors discuss in detail spin
decoherence mechanisms in metals and semiconductors. Various theories of spin
injection and spin-polarized transport are applied to hybrid structures
relevant to spin-based devices and fundamental studies of materials properties.
Experimental work is reviewed with the emphasis on projected applications, in
which external electric and magnetic fields and illumination by light will be
used to control spin and charge dynamics to create new functionalities not
feasible or ineffective with conventional electronics.Comment: invited review, 36 figures, 900+ references; minor stylistic changes
from the published versio
A prospective cohort study of dietary patterns of non-western migrants in the Netherlands in relation to risk factors for cardiovascular diseases: HELIUS-Dietary Patterns
<p>Abstract</p> <p>Background</p> <p>In Western countries the prevalence of cardiovascular disease (CVD) is often higher in non-Western migrants as compared to the host population. Diet is an important modifiable determinant of CVD. Increasingly, dietary patterns rather than single nutrients are the focus of research in an attempt to account for the complexity of nutrient interactions in foods. Research on dietary patterns in non-Western migrants is limited and may be hampered by a lack of validated instruments that can be used to assess the habitual diet of non-western migrants in large scale epidemiological studies. The ultimate aims of this study are to (1) understand whether differences in dietary patterns explain differences in CVD risk between ethnic groups, by developing and validating ethnic-specific Food Frequency Questionnaires (FFQs), and (2) to investigate the determinants of these dietary patterns. This paper outlines the design and methods used in the HELIUS-Dietary Patterns study and describes a systematic approach to overcome difficulties in the assessment and analysis of dietary intake data in ethnically diverse populations.</p> <p>Methods/Design</p> <p>The HELIUS-Dietary Patterns study is embedded in the HELIUS study, a Dutch multi-ethnic cohort study. After developing ethnic-specific FFQs, we will gather data on the habitual intake of 5000 participants (18-70 years old) of ethnic Dutch, Surinamese of African and of South Asian origin, Turkish or Moroccan origin. Dietary patterns will be derived using factor analysis, but we will also evaluate diet quality using hypothesis-driven approaches. The relation between dietary patterns and CVD risk factors will be analysed using multiple linear regression analysis. Potential underlying determinants of dietary patterns like migration history, acculturation, socio-economic factors and lifestyle, will be considered.</p> <p>Discussion</p> <p>This study will allow us to investigate the contribution of the dietary patterns on CVD risk factors in a multi-ethnic population. Inclusion of five ethnic groups residing in one setting makes this study highly innovative as confounding by local environment characteristics is limited. Heterogeneity in the study population will provide variance in dietary patterns which is a great advantage when studying the link between diet and disease.</p
ConsistentNeRF: Enhancing Neural Radiance Fields with 3D Consistency for Sparse View Synthesis
Neural Radiance Fields (NeRF) has demonstrated remarkable 3D reconstruction
capabilities with dense view images. However, its performance significantly
deteriorates under sparse view settings. We observe that learning the 3D
consistency of pixels among different views is crucial for improving
reconstruction quality in such cases. In this paper, we propose ConsistentNeRF,
a method that leverages depth information to regularize both multi-view and
single-view 3D consistency among pixels. Specifically, ConsistentNeRF employs
depth-derived geometry information and a depth-invariant loss to concentrate on
pixels that exhibit 3D correspondence and maintain consistent depth
relationships. Extensive experiments on recent representative works reveal that
our approach can considerably enhance model performance in sparse view
conditions, achieving improvements of up to 94% in PSNR, 76% in SSIM, and 31%
in LPIPS compared to the vanilla baselines across various benchmarks, including
DTU, NeRF Synthetic, and LLFF.Comment: https://github.com/skhu101/ConsistentNeR
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