448 research outputs found
Federated Neural Architecture Search
To preserve user privacy while enabling mobile intelligence, techniques have
been proposed to train deep neural networks on decentralized data. However,
training over decentralized data makes the design of neural architecture quite
difficult as it already was. Such difficulty is further amplified when
designing and deploying different neural architectures for heterogeneous mobile
platforms. In this work, we propose an automatic neural architecture search
into the decentralized training, as a new DNN training paradigm called
Federated Neural Architecture Search, namely federated NAS. To deal with the
primary challenge of limited on-client computational and communication
resources, we present FedNAS, a highly optimized framework for efficient
federated NAS. FedNAS fully exploits the key opportunity of insufficient model
candidate re-training during the architecture search process, and incorporates
three key optimizations: parallel candidates training on partial clients, early
dropping candidates with inferior performance, and dynamic round numbers.
Tested on large-scale datasets and typical CNN architectures, FedNAS achieves
comparable model accuracy as state-of-the-art NAS algorithm that trains models
with centralized data, and also reduces the client cost by up to two orders of
magnitude compared to a straightforward design of federated NAS
D&D: Learning Human Dynamics from Dynamic Camera
3D human pose estimation from a monocular video has recently seen significant
improvements. However, most state-of-the-art methods are kinematics-based,
which are prone to physically implausible motions with pronounced artifacts.
Current dynamics-based methods can predict physically plausible motion but are
restricted to simple scenarios with static camera view. In this work, we
present D&D (Learning Human Dynamics from Dynamic Camera), which leverages the
laws of physics to reconstruct 3D human motion from the in-the-wild videos with
a moving camera. D&D introduces inertial force control (IFC) to explain the 3D
human motion in the non-inertial local frame by considering the inertial forces
of the dynamic camera. To learn the ground contact with limited annotations, we
develop probabilistic contact torque (PCT), which is computed by differentiable
sampling from contact probabilities and used to generate motions. The contact
state can be weakly supervised by encouraging the model to generate correct
motions. Furthermore, we propose an attentive PD controller that adjusts target
pose states using temporal information to obtain smooth and accurate pose
control. Our approach is entirely neural-based and runs without offline
optimization or simulation in physics engines. Experiments on large-scale 3D
human motion benchmarks demonstrate the effectiveness of D&D, where we exhibit
superior performance against both state-of-the-art kinematics-based and
dynamics-based methods. Code is available at https://github.com/Jeffsjtu/DnDComment: ECCV 2022 (Oral
Glycosphingolipid GM3 is Indispensable for Dengue Virus Genome Replication
Dengue virus (DENV) causes the most prevalent arthropod-borne viral disease of humans worldwide. Glycosphingolipids (GSLs) are involved in virus infection by regulating various steps of viral-host interaction. However, the distinct role of GSLs during DENV infection remains unclear. In this study, we used mouse melanoma B16 cells and their GSL-deficient mutant counterpart GM95 cells to study the influence of GSLs on DENV infection. Surprisingly, GM95 cells were highly resistant to DENV infection compared with B16 cells. Pretreatment of B16 cells with synthetase inhibitor of GM3, the most abundant GSLs in B16 cells, or silencing GM3 synthetase T3GAL5, significantly inhibited DENV infection. DENV attachment and endocytosis were not impaired in GM95 cells, but DENV genome replication was obviously inhibited in GM95 cells compared to B16 cells. Furthermore, GM3 was colocalized with DENV viral replication complex on endoplasmic reticulum (ER) inside the B16 cells. Finally, GM3 synthetase inhibitor significantly reduced the mortality rate of suckling mice that challenged with DENV by impairing the viral replication in mouse brain. Taken together, these data indicated that GM3 was not required for DENV attachment and endocytosis, however, essential for viral genome replication. Targeting GM3 could be a novel strategy to inhibit DENV infection
Research on the Design of Survery Lines in a Marine Magnetic Survey
The planning of a marine magnetic survey requires careful consideration in the design of the survey lines to ensure the results of the survey meet expected standards. This paper describes various evaluation methods to determine an optimal survey line layout for a marine magnetic survey that conforms to Chinese marine magnetic survey Standards. Various survey line layouts are tested using simulated data to evaluate the interpolation precision between neighbouring survey lines and the magnetic anomaly map. The test results provide a recommended process to determine the rationality and the optimal layout of the survey line pattern for undertaking marine magnetic surveys.La planificación de un levantamiento magnético marino requiere una cuidadosa consideración en el diseño de las trayectorias a seguir para garantizar que los resultados del levantamiento cumplan las normas esperadas. Este artÃculo describe los diversos métodos de evaluación para determinar una disposición óptima de las trayectorias para un levantamiento magnético marino que sea conforme a las normas chinas de levantamientos magnéticos marinos. Se han efectuado pruebas sobre varias disposiciones de trayectorias, utilizando datos simulados para evaluar la precisión de la interpolación entre trayectorias vecinas y el mapa de anomalÃas magnéticas. Los resultados de las pruebas proporcionan un proceso recomendado para determinar la racionalidad y la disposición óptima del patrón de trayectorias para llevar cabo levantamientos magnéticos marinos.La planification d’un levé magnétique marin requiert un examen minutieux de la conception des profils de sonde pour assurer que les résultats du levé répondent aux normes attendues. Cet article décrit différentes méthodes d’évaluation en vue de déterminer une présentation de profil de sonde optimale pour un levé magnétique marin qui soit conforme aux normes des levés magnétiques marins chinois. Diverses présentations de profils de sonde sont testées à l’aide de données simulées dans le but d’évaluer la précision de l’interpolation entre profils de sonde voisins et la carte des anomalies magnétiques Les résultats des tests permettent de recommander un processus pour déterminer la rationalité et la présentation optimale du schéma de profil de sonde afin d’entreprendre des levés magnétiques marins
Vibronic Fingerprint of Singlet Fission in Hexacene
Singlet fission has the great potential to overcome the Shockley–Queisser thermodynamic limit and thus promotes solar power conversion efficiency. However, the current limited understandings of detailed singlet fission mechanisms hinder a further improved design of versatile singlet fission materials. In the present study, we combined ultrafast transient infrared spectroscopy with ab initio calculations to elucidate the roles played by the vibrational normal modes in the process of singlet fission for hexacene. Our transient infrared experiments revealed three groups of vibrational modes that are prominent in vibronic coupling upon photoexcitation. Through our computational study, those normal modes with notable Franck-Condon shifts have been classified as ring-twisting modes near 1300.0 cm−1, ring-stretching modes near 1600.0 cm−1, and ring-scissoring modes near 1700.0 cm−1. Experimentally, a ring-stretching mode near 1620.0 cm−1 exhibits a significant blue-shift of 4.0 cm−1 during singlet fission, which reaction rate turns out to be 0.59 ± 0.07 ps. More interestingly, the blue-shifted mode was also identified by our functional mode singlet fission theory as the primary driving mode for singlet fission, suggesting the importance of vibronic coupling when a correlated triplet pair of hexacene is directly converted from its first excited state singlet exciton. Our findings indicate that the ultrafast transient infrared spectroscopy, in conjunction with the nonadiabatic transition theory, is a powerful tool to probe the vibronic fingerprint of singlet fission
A Novel Bio-based Sulfonic Zwitterionic Surfactant Derived from Transgenic Soybean Oil and its Performance in Surface and Interfacial Activities
Bio-based surfactants have attracted increasing attention due to their renewable resources and excellent surface properties. In this study, a novel bio-based sulfonic zwitterionic surfactant (BSZS) derived from transgenic soybean oil was prepared using a simple reaction route with two steps of the amidation and quaterisation. The bio-based sulfonic zwitterionic surfactant showed a critical micelle concentration (CMC) as low as 33.34 mg/L with a surface tension of 28.50 mN/m. In addition, it also showed good performance in foamability, emulsibility, and wettability. The excellent performances indicated the great potential applications of the bio-based sulfonic surfactant from vegetable oils in both daily life and industrial fields.Bio-based surfactants have attracted increasing attention due to their renewable resources and excellent surface properties. In this study a novel biobased sulfonic zwitterionic surfactant (BSZS) derived from genetically modified(GM) soybean oil was prepared using a simple reaction route with two steps of the amidation and quaterisation. The BSZS showed a critical micelle concentration (CMC) as low as 33.3 mg/L with a surface tension of 28.5 mN/m. In addition, it also showed good performance in foamability, emulsibility and wettability. The excellent performances indicated great potential applications of the bio-based sulfonic surfactant from vegetable oil in both daily life and industrial fields
New Self-Similar Solutions of Polytropic Gas Dynamics
We explore semi-complete self-similar solutions for the polytropic gas
dynamics involving self-gravity under spherical symmetry, examine behaviours of
the sonic critical curve, and present new asymptotic collapse solutions that
describe `quasi-static' asymptotic behaviours at small radii and large times.
These new `quasi-static' solutions with divergent mass density approaching the
core can have self-similar oscillations. Earlier known solutions are
summarized. Various semi-complete self-similar solutions involving such novel
asymptotic solutions are constructed, either with or without a shock. In
contexts of stellar core collapse and supernova explosion, a hydrodynamic model
of a rebound shock initiated around the stellar degenerate core of a massive
progenitor star is presented. With this dynamic model framework, we attempt to
relate progenitor stars and the corresponding remnant compact stars: neutron
stars, black holes, and white dwarfs.Comment: 17 pages, 11 figures, Accepted for publication in MNRA
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