Surface/underwater target classification is a key topic in marine information research.However,the complex underwater environment,coupled with the diversity of target types and their variable characteristics,presents ...Surface/underwater target classification is a key topic in marine information research.However,the complex underwater environment,coupled with the diversity of target types and their variable characteristics,presents significant challenges for classifier design.For shallow-water waveguides with a negative thermocline,a residual neural network(ResNet)model based on the sound field elevation structure is constructed.This model demonstrates robust classification performance even when facing low signal-to-noise ratios and environmental mismatches.Meanwhile,to address the reduced generalization ability caused by limited labeled acoustic data,an improved ResNet model based on unsupervised domain adaptation(“proposed UDA-ResNet”)is further constructed.This model incorporates data on simulated elevation structures of the sound field to augment the training process.Adversarial training is employed to extract domain-invariant features from simulated and trial data.These strategies help reduce the negative impact caused by domain differences.Experimental results demonstrate that the proposed method shows strong surface/underwater target classification ability under limited sample sizes,thus confirming its feasibility and effectiveness.展开更多
The vibrations and noises of elevated railway structures have been cause for concern due to their effects on the environment and the people living near elevated lines.In this paper,the main structural features of some...The vibrations and noises of elevated railway structures have been cause for concern due to their effects on the environment and the people living near elevated lines.In this paper,the main structural features of some new elevated bridges and station hall were introduced.The generation mechanism of vibrations and noise of elevated structures induced by trains were investigated.The noise induced by different types of elevated bridges,their influences on the environment and the theoretical method for the analysis of structure borne noise was analyzed.Finally,several field measurements on train induced noises at the platforms of elevated subway stations and bridges were presented.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.62471024 and 62301183)the Open Research Fund of Hanjiang Laboratory(KF2024001).
文摘Surface/underwater target classification is a key topic in marine information research.However,the complex underwater environment,coupled with the diversity of target types and their variable characteristics,presents significant challenges for classifier design.For shallow-water waveguides with a negative thermocline,a residual neural network(ResNet)model based on the sound field elevation structure is constructed.This model demonstrates robust classification performance even when facing low signal-to-noise ratios and environmental mismatches.Meanwhile,to address the reduced generalization ability caused by limited labeled acoustic data,an improved ResNet model based on unsupervised domain adaptation(“proposed UDA-ResNet”)is further constructed.This model incorporates data on simulated elevation structures of the sound field to augment the training process.Adversarial training is employed to extract domain-invariant features from simulated and trial data.These strategies help reduce the negative impact caused by domain differences.Experimental results demonstrate that the proposed method shows strong surface/underwater target classification ability under limited sample sizes,thus confirming its feasibility and effectiveness.
基金supported by the Key Project of the Natural Science Foundation of China(Grant No.50538010)the Natural Science Foundation of Beijing(Grant No.8082021)the Flander(Belgium)-China Bilateral Project(No.BIL07/07).
文摘The vibrations and noises of elevated railway structures have been cause for concern due to their effects on the environment and the people living near elevated lines.In this paper,the main structural features of some new elevated bridges and station hall were introduced.The generation mechanism of vibrations and noise of elevated structures induced by trains were investigated.The noise induced by different types of elevated bridges,their influences on the environment and the theoretical method for the analysis of structure borne noise was analyzed.Finally,several field measurements on train induced noises at the platforms of elevated subway stations and bridges were presented.
