557 research outputs found
A Real-time Method for Inserting Virtual Objects into Neural Radiance Fields
We present the first real-time method for inserting a rigid virtual object
into a neural radiance field, which produces realistic lighting and shadowing
effects, as well as allows interactive manipulation of the object. By
exploiting the rich information about lighting and geometry in a NeRF, our
method overcomes several challenges of object insertion in augmented reality.
For lighting estimation, we produce accurate, robust and 3D spatially-varying
incident lighting that combines the near-field lighting from NeRF and an
environment lighting to account for sources not covered by the NeRF. For
occlusion, we blend the rendered virtual object with the background scene using
an opacity map integrated from the NeRF. For shadows, with a precomputed field
of spherical signed distance field, we query the visibility term for any point
around the virtual object, and cast soft, detailed shadows onto 3D surfaces.
Compared with state-of-the-art techniques, our approach can insert virtual
object into scenes with superior fidelity, and has a great potential to be
further applied to augmented reality systems
Nonemptiness and Compactness of Solutions Set for Nondifferentiable Multiobjective Optimization Problems
A nondifferentiable multiobjective optimization problem with nonempty set constraints is considered, and the equivalence of weakly efficient solutions, the critical points for the nondifferentiable multiobjective optimization problems, and solutions for vector variational-like inequalities is established under some suitable conditions. Nonemptiness and compactness of the solutions set for the nondifferentiable multiobjective optimization problems are proved by using the FKKM theorem and a fixed-point theorem
Full-range Gate-controlled Terahertz Phase Modulations with Graphene Metasurfaces
Local phase control of electromagnetic wave, the basis of a diverse set of
applications such as hologram imaging, polarization and wave-front
manipulation, is of fundamental importance in photonic research. However, the
bulky, passive phase modulators currently available remain a hurdle for
photonic integration. Here we demonstrate full-range active phase modulations
in the Tera-Hertz (THz) regime, realized by gate-tuned ultra-thin reflective
metasurfaces based on graphene. A one-port resonator model, backed by our
full-wave simulations, reveals the underlying mechanism of our extreme phase
modulations, and points to general strategies for the design of tunable
photonic devices. As a particular example, we demonstrate a gate-tunable THz
polarization modulator based on our graphene metasurface. Our findings pave the
road towards exciting photonic applications based on active phase
manipulations
A System of Random Nonlinear Variational Inclusions Involving Random Fuzzy Mappings and -Monotone Set-Valued Mappings
GM-TCNet: Gated Multi-scale Temporal Convolutional Network using Emotion Causality for Speech Emotion Recognition
In human-computer interaction, Speech Emotion Recognition (SER) plays an
essential role in understanding the user's intent and improving the interactive
experience. While similar sentimental speeches own diverse speaker
characteristics but share common antecedents and consequences, an essential
challenge for SER is how to produce robust and discriminative representations
through causality between speech emotions. In this paper, we propose a Gated
Multi-scale Temporal Convolutional Network (GM-TCNet) to construct a novel
emotional causality representation learning component with a multi-scale
receptive field. GM-TCNet deploys a novel emotional causality representation
learning component to capture the dynamics of emotion across the time domain,
constructed with dilated causal convolution layer and gating mechanism.
Besides, it utilizes skip connection fusing high-level features from different
gated convolution blocks to capture abundant and subtle emotion changes in
human speech. GM-TCNet first uses a single type of feature, mel-frequency
cepstral coefficients, as inputs and then passes them through the gated
temporal convolutional module to generate the high-level features. Finally, the
features are fed to the emotion classifier to accomplish the SER task. The
experimental results show that our model maintains the highest performance in
most cases compared to state-of-the-art techniques.Comment: The source code is available at:
https://github.com/Jiaxin-Ye/GM-TCNe
Molluscicidal efficacies of different formulations of niclosamide: result of meta-analysis of Chinese literature
The control efforts on Oncomelania hupensis, the intermediate snail host of Schistosoma japonicum, cannot be easily excluded from the integrated approach of schistosomiasis control in China. Application of chemical compounds, molluscicides, in snail habitats is a common method for snail control in addition to environmental modification. We conducted a systematic review and meta-analysis to assess the molluscicidal effects of the currently recommended 50% niclosamide ethanolamine salt wettable powder and a new 4% niclosamide ethanolamine salt powder developed by Chinese researchers. Literature was searched from three Chinese databases, i.e. Chinese Biomedical Database, VIP Database and Wanfang Database, on field mollusciciding trials of niclosamide in China (from January 1, 1990 to April 1, 2010). Molluscicidal effects on reduction of snail population of the 50% or 4% niclosamide formulations in field trial were evaluated 3 days, 7 days or 15 days post-application. Out of 90 publications, 20 papers were eventually selected for analysis. Publication bias and heterogeneity tests indicated that no publication bias existed but heterogeneity between studies was present. Meta-analysis in a random effect model showed that the snail mortality of 3, 7 and 15 days after spraying the 50% niclosamide ethanolamine salt wettable powder were 77% [95%CI: 0.68-0.86], 83% [95%CI: 0.77-0.89], and 88% [95%CI: 0.82-0.92], respectively. For the 4% niclosamide ethanolamine salt powder, the snail mortality after 3, 7 and 15 days were 81% [95%CI: 0.65-0.93], 90% [95%CI: 0.83-0.95] and 94% [95%CI: 0.91-0.97], respectively. Both are good enough to be used as molluscicides integrated with a schistosomiasis control programme. The 4% niclosamide ethanolamine salt powder can be applied in the field without water supply as the surrogate of the current widely used 50% niclosamide ethanolamine salt wettable powder. However, to consolidate the schistosomiasis control achievement gained, it is necessary to continuously perform mollusciciding more than twice annually in the field
Elevated plasma pyruvate kinase M2 concentrations are associated with the clinical severity and prognosis of coronary artery disease
Graphical abstract
Highlights
Pyruvate kinase M2 is a predictor of clinical severity of coronary artery disease
Pyruvate kinase M2 predicts the incidence of major adverse cardiovascular events
Pyruvate kinase M2 showed additional prognostic value in coronary artery disease
IntroductionPyruvate kinase M2 (PKM2) was involved in the pathophysiology of atherosclerosis and coronary artery disease (CAD). We tested whether plasma PKM2 concentrations were correlated with clinical severity and major adverse cardiovascular events (MACEs) in CAD patients.
Materials and methodsA total of 2443 CAD patients and 238 controls were enrolled. The follow-up time was two years. Plasma PKM2 concentrations were detected by enzyme-linked immunosorbent assay (ELISA) kits (Cloud-Clone, Wuhan, China) using SpectraMax i3x Multi-Mode Microplate Reader (Molecular Devices, San Jose, USA). The predictors of acute coronary syndrome (ACS) were assessed by logistic regression analysis. The association between PKM2 concentration in different quartiles and MACEs was evaluated by Kaplan-Meier (KM) curves with log-rank test and Cox proportional hazard models. The predictive value of PKM2 and a cluster of conventional risk factors was determined by Receiver operating characteristic (ROC) curves. The net reclassification improvement (NRI) and the integrated discrimination improvement (IDI) were utilized to evaluate the enhancement in risk prediction when PKM2 was added to a predictive model containing a cluster of conventional risk factors.
ResultsIn CAD patients, PKM2 concentration was the independent predictor of ACS (P < 0.001). Kaplan-Meier cumulative survival curves and Cox proportional hazards analyses revealed that patients with a higher PKM2 concentration had higher incidence of MACEs compared to those with a lower PKM2 concentration (P < 0.001). The addition of PKM2 to a cluster of conventional risk factors significantly increased its prognostic value of MACEs.
ConclusionBaseline plasma PKM2 concentrations predict the clinical severity and prognosis of CAD
Spatio-temporal reconstruction for 3D motion recovery
—This paper addresses the challenge of 3D motion
recovery by exploiting the spatio-temporal correlations of corrupted 3D skeleton sequences. We propose a new 3D motion recovery method using spatio-temporal reconstruction, which uses
joint low-rank and sparse priors to exploit temporal correlation
and an isometric constraint for spatial correlation. The proposed
model is formulated as a constrained optimization problem,
which is efficiently solved by the augmented Lagrangian method
with a Gauss-Newton solver for the subproblem of isometric
optimization. Experimental results on the CMU motion capture
dataset, Edinburgh dataset and two Kinect datasets demonstrate
that the proposed approach achieves better motion recovery
than state-of-the-art methods. The proposed method is applicable
to Kinect-like skeleton tracking devices and pose estimation
methods that cannot provide accurate estimation of complex
motions, especially in the presence of occlusion
The topological differences between visitation and pollen transport networks: a comparison in species rich communities of the Himalaya–Hengduan Mountains
Pollination networks are usually constructed and assessed by direct field observations which commonly assume that all flower visitors are true pollinators. However, this assumption is often invalid and the use of data based on mere visitors to flowers may lead to a misunderstanding of intrinsic pollination networks. Here, using a large dataset by both sampling floral visitors and analyzing their pollen loads, we constructed 32 networks pairs (visitation versus pollen transport) across one flowering season at four elevation sites in the Himalaya–Hengduan Mountains region. Pollen analysis was conducted to determine which flower visitors acted as potential pollinators (pollen vectors) or as cheaters (those not carrying pollen of the visited plants). We tested whether there were topological differences between visitation and pollen transport networks and whether different taxonomic groups of insect visitors differed in their ability to carry pollen of the visited plants. Our results indicated that there was a significantly higher degree of specialization at both the network and species levels in the pollen transport networks in contrast to the visitation networks. Modularity was lower but nestedness was higher in the visitation networks compared to the pollen transport networks. All the cheaters were identified as peripheral species and most of them contributed positively to the nested structure. This may explain in part the differences in modularity and nestedness between the two network types. Bees carried the highest proportion of pollen of the visited plants. This was followed by Coleoptera, other Hymenoptera and Diptera. Lepidoptera carried the lowest proportion of pollen of the visited plants. Our study shows that the construction of pollen transport networks could provide a more in-depth understanding of plant–pollinator interactions. Moreover, it suggests that detecting and removing cheater interactions when studying the topology of other mutualistic networks might be also important.This study was supported by Strategic Priority Research Program of the Chinese Academy of Sciences (XDB31020000), National Key Basic Research Program of China (2014CB954100), Joint Fund of the National Natural Science Foundation of China-Yunnan Province (U1502261), Major International Joint Research Project of NSF China (31320103919), Applied Fundamental Research Foundation of Yunnan Province (2014GA003), National Natural Science Foundation of China (31700361), Yunlin Scholarship of Yunnan Province to H. Wang (YLXL20170001) and CAS ‘Light of West China’ Program to Y.H. Zhao. A. Lázaro was supported by a Ramóny Cajal contract financed by the Spanish Ministry of Economy and Competitiveness
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