Aiming at training the feed-forward threshold neural network consisting of nondifferentiable activation functions, the approach of noise injection forms a stochastic resonance based threshold network that can be optim...Aiming at training the feed-forward threshold neural network consisting of nondifferentiable activation functions, the approach of noise injection forms a stochastic resonance based threshold network that can be optimized by various gradientbased optimizers. The introduction of injected noise extends the noise level into the parameter space of the designed threshold network, but leads to a highly non-convex optimization landscape of the loss function. Thus, the hyperparameter on-line learning procedure with respective to network weights and noise levels becomes of challenge. It is shown that the Adam optimizer, as an adaptive variant of stochastic gradient descent, manifests its superior learning ability in training the stochastic resonance based threshold network effectively. Experimental results demonstrate the significant improvement of performance of the designed threshold network trained by the Adam optimizer for function approximation and image classification.展开更多
The biosynthetic potential of actinobacteria to produce novel natural products is still regarded as immense.In this paper,we correlated a cryptic biosynthetic gene cluster to chemical molecules by genome mining and ch...The biosynthetic potential of actinobacteria to produce novel natural products is still regarded as immense.In this paper,we correlated a cryptic biosynthetic gene cluster to chemical molecules by genome mining and chemical analyses,leading to the discovery of a new group of catecholate-hydroxamate siderophores,nobachelins,from Nocardiopsis baichengensis DSM 44845.Nobachelin biosynthesis genes are conserved in several bacteria from the family Nocardiopsidaceae.Structurally,nobachelins feature fatty-acylated hydroxy-ornithine and a rare chlorinated catecholate group.Intriguingly,nobachelins rescued Caenorhabditis elegans from Pseudomonas aeruginosa-mediated killing.展开更多
The World Health Organization has projected that by 2030,chronic obstructive pulmonary disease(COPD)will be the third-leading cause of mortality and the seventh-leading cause of morbidity worldwide.[1]Acute exacerbati...The World Health Organization has projected that by 2030,chronic obstructive pulmonary disease(COPD)will be the third-leading cause of mortality and the seventh-leading cause of morbidity worldwide.[1]Acute exacerbations of chronic obstructive pulmonary disease(AECOPD)are associated with an accelerated decline in lung function,diminished quality of life,and higher mortality.[2]Accurate early detection of AECOPD contributes to better management and mortality reduction,and in the recent past there has been great progress in the development and application of machine learning(ML),which is an important part of predictive analytics incorporating predictive models that improve with increasing numbers of cases,in seeking ways to better tackle COPD.展开更多
Asymmetric microcavities supporting Whispering-gallery modes(WGMs)are of great significance for on-chip optical information processing.We establish asymmetric microcavities on topologically curved surfaces,where the g...Asymmetric microcavities supporting Whispering-gallery modes(WGMs)are of great significance for on-chip optical information processing.We establish asymmetric microcavities on topologically curved surfaces,where the geodesic light trajectories completely reconstruct the cavity mode features.The curvature-mediated photon-lifetime engineering enables the enhancement of the quality factors of periodic island modes by up to 200 times.Strong and weak coupling between modes of very different origins occurs when the space curvature brings them into resonance,leading to fine tailoring of the cavity photon energy and lifetime and the observation of non-Hermitian exceptional point(EP).At large space curvatures,the role of the WGMs is replaced by high-Q periodic modes protected by the high stability of island-like light trajectory.Our work demonstrates interesting physical mechanisms at the crosspoint of optical chaotic dynamics,non-Hermitian physics,and geodesic optical devices,and would initiate the novel area of geodesic microcavity photonics.展开更多
基金Project supported by the Natural Science Foundation of Shandong Province,China(Grant No.ZR2021MF051)。
文摘Aiming at training the feed-forward threshold neural network consisting of nondifferentiable activation functions, the approach of noise injection forms a stochastic resonance based threshold network that can be optimized by various gradientbased optimizers. The introduction of injected noise extends the noise level into the parameter space of the designed threshold network, but leads to a highly non-convex optimization landscape of the loss function. Thus, the hyperparameter on-line learning procedure with respective to network weights and noise levels becomes of challenge. It is shown that the Adam optimizer, as an adaptive variant of stochastic gradient descent, manifests its superior learning ability in training the stochastic resonance based threshold network effectively. Experimental results demonstrate the significant improvement of performance of the designed threshold network trained by the Adam optimizer for function approximation and image classification.
基金support from the Helmholtz International Lab(InterLabs0007)Yuhao Ren acknowledges the support from the International Postdoctoral Exchange Fellowship Program(ZD202125)between Helmholtz AssociationGermany and the Office of China Postdoc Council(OCPC),China.
文摘The biosynthetic potential of actinobacteria to produce novel natural products is still regarded as immense.In this paper,we correlated a cryptic biosynthetic gene cluster to chemical molecules by genome mining and chemical analyses,leading to the discovery of a new group of catecholate-hydroxamate siderophores,nobachelins,from Nocardiopsis baichengensis DSM 44845.Nobachelin biosynthesis genes are conserved in several bacteria from the family Nocardiopsidaceae.Structurally,nobachelins feature fatty-acylated hydroxy-ornithine and a rare chlorinated catecholate group.Intriguingly,nobachelins rescued Caenorhabditis elegans from Pseudomonas aeruginosa-mediated killing.
基金Suzhou Special Technical Project for Diagnosis and Treatment of Key Clinical Diseases(No.LCZX201931)
文摘The World Health Organization has projected that by 2030,chronic obstructive pulmonary disease(COPD)will be the third-leading cause of mortality and the seventh-leading cause of morbidity worldwide.[1]Acute exacerbations of chronic obstructive pulmonary disease(AECOPD)are associated with an accelerated decline in lung function,diminished quality of life,and higher mortality.[2]Accurate early detection of AECOPD contributes to better management and mortality reduction,and in the recent past there has been great progress in the development and application of machine learning(ML),which is an important part of predictive analytics incorporating predictive models that improve with increasing numbers of cases,in seeking ways to better tackle COPD.
基金the National Key R&D Program of China(2018YFA0306101 and 2021YFA1400800)the National Natural Science Foundation of China(12074303,11804267,11904279,62035017,11874437,12074442 and 91836303)+4 种基金Shaanxi Key Science and Technology Innovation Team Project(2021TD-56)Key-Area Research and Development Program of Guangdong Province(20188030329001)the Guangdong Special Support Program(2019JC05X397)the Local Innovative and Research Teams Project of the Guangdong Pearl River Talents Program(2017BT01X121)the National Super-Computer Center in Guangzhou.
文摘Asymmetric microcavities supporting Whispering-gallery modes(WGMs)are of great significance for on-chip optical information processing.We establish asymmetric microcavities on topologically curved surfaces,where the geodesic light trajectories completely reconstruct the cavity mode features.The curvature-mediated photon-lifetime engineering enables the enhancement of the quality factors of periodic island modes by up to 200 times.Strong and weak coupling between modes of very different origins occurs when the space curvature brings them into resonance,leading to fine tailoring of the cavity photon energy and lifetime and the observation of non-Hermitian exceptional point(EP).At large space curvatures,the role of the WGMs is replaced by high-Q periodic modes protected by the high stability of island-like light trajectory.Our work demonstrates interesting physical mechanisms at the crosspoint of optical chaotic dynamics,non-Hermitian physics,and geodesic optical devices,and would initiate the novel area of geodesic microcavity photonics.
