192 research outputs found
An Intelligent Social Learning-based Optimization Strategy for Black-box Robotic Control with Reinforcement Learning
Implementing intelligent control of robots is a difficult task, especially
when dealing with complex black-box systems, because of the lack of visibility
and understanding of how these robots work internally. This paper proposes an
Intelligent Social Learning (ISL) algorithm to enable intelligent control of
black-box robotic systems. Inspired by mutual learning among individuals in
human social groups, ISL includes learning, imitation, and self-study styles.
Individuals in the learning style use the Levy flight search strategy to learn
from the best performer and form the closest relationships. In the imitation
style, individuals mimic the best performer with a second-level rapport by
employing a random perturbation strategy. In the self-study style, individuals
learn independently using a normal distribution sampling method while
maintaining a distant relationship with the best performer. Individuals in the
population are regarded as autonomous intelligent agents in each style. Neural
networks perform strategic actions in three styles to interact with the
environment and the robot and iteratively optimize the network policy. Overall,
ISL builds on the principles of intelligent optimization, incorporating ideas
from reinforcement learning, and possesses strong search capabilities, fast
computation speed, fewer hyperparameters, and insensitivity to sparse rewards.
The proposed ISL algorithm is compared with four state-of-the-art methods on
six continuous control benchmark cases in MuJoCo to verify its effectiveness
and advantages. Furthermore, ISL is adopted in the simulation and experimental
grasping tasks of the UR3 robot for validations, and satisfactory solutions are
yielded
Continual Learning For On-Device Environmental Sound Classification
Continuously learning new classes without catastrophic forgetting is a
challenging problem for on-device environmental sound classification given the
restrictions on computation resources (e.g., model size, running memory). To
address this issue, we propose a simple and efficient continual learning
method. Our method selects the historical data for the training by measuring
the per-sample classification uncertainty. Specifically, we measure the
uncertainty by observing how the classification probability of data fluctuates
against the parallel perturbations added to the classifier embedding. In this
way, the computation cost can be significantly reduced compared with adding
perturbation to the raw data. Experimental results on the DCASE 2019 Task 1 and
ESC-50 dataset show that our proposed method outperforms baseline continual
learning methods on classification accuracy and computational efficiency,
indicating our method can efficiently and incrementally learn new classes
without the catastrophic forgetting problem for on-device environmental sound
classification.Comment: The first two authors contributed equally, 5 pages one figure,
submitted to DCASE2022 Worksho
Emotional Voice Puppetry
The paper presents emotional voice puppetry, an audio-based facial animation approach to portray characters with vivid emotional changes. The lips motion and the surrounding facial areas are controlled by the contents of the audio, and the facial dynamics are established by category of the emotion and the intensity. Our approach is exclusive because it takes account of perceptual validity and geometry instead of pure geometric processes. Another highlight of our approach is the generalizability to multiple characters. The findings showed that training new secondary characters when the rig parameters are categorized as eye, eyebrows, nose, mouth, and signature wrinkles is significant in achieving better generalization results compared to joint training. User studies demonstrate the effectiveness of our approach both qualitatively and quantitatively. Our approach can be applicable in AR/VR and 3DUI, namely, virtual reality avatars/self-avatars, teleconferencing and in-game dialogue
Maternal exposure to ambient air pollution and congenital heart defects in China
Background: Evidence of maternal exposure to ambient air pollution on congenital heart defects (CHD) has been mixed and are still relatively limited in developing countries. We aimed to investigate the association between maternal exposure to air pollution and CHD in China.Method: This longitudinal, population-based, case-control study consecutively recruited fetuses with CHD and healthy volunteers from 21 cities, Southern China, between January 2006 and December 2016. Residential address at delivery was linked to random forests models to estimate maternal exposure to particulate matter with an aerodynamic diameter of ≤1 µm (PM1), ≤2.5 µm, and ≤10 µm as well as nitrogen dioxides, in three trimesters. The CHD cases were evaluated by obstetrician, pediatrician, or cardiologist, and confirmed by cardia ultrasound. The CHD subtypes were coded using the International Classification Diseases. Adjusted logistic regression models were used to assess the associations between air pollutants and CHD and its subtypes.Results: A total of 7055 isolated CHD and 6423 controls were included in the current analysis. Maternal air pollution exposures were consistently higher among cases than those among controls. Logistic regression analyses showed that maternal exposure to all air pollutants during the first trimester was associated with an increased odds of CHD (e.g., an interquartile range [13.3 µg/m3] increase in PM1 was associated with 1.09-fold ([95% confidence interval, 1.01-1.18]) greater odds of CHD). No significant associations were observed for maternal air pollution exposures during the second trimester and the third trimester. The pattern of the associations between air pollutants and different CHD subtypes was mixed.Conclusions: Maternal exposure to greater levels of air pollutants during the pregnancy, especially the first trimester, is associated with higher odds of CHD in offspring. Further longitudinal well-designed studies are warranted to confirm our findings
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