描述了大屏幕液晶电视图像画质的改善。在屏幕尺寸上已经超过C R T的液晶电视,即使屏幕尺寸达到60英寸,也可以实现全屏100%亮度的高水准。另一方面,高亮度和大尺寸屏幕使液晶电视在图像画质方面存在的问题变得更加明显,因此应当对它们...描述了大屏幕液晶电视图像画质的改善。在屏幕尺寸上已经超过C R T的液晶电视,即使屏幕尺寸达到60英寸,也可以实现全屏100%亮度的高水准。另一方面,高亮度和大尺寸屏幕使液晶电视在图像画质方面存在的问题变得更加明显,因此应当对它们加以解决。例如可见轮廓、动画模糊以及M PEG压缩引起的图像压缩失真及其补偿算法都将在本文中描述。展开更多
Damage mechanism identification has scientific and practical ramifications for the structural health monitoring,design,and application of composite systems.Recent advances in machine learning uncover pathways to ident...Damage mechanism identification has scientific and practical ramifications for the structural health monitoring,design,and application of composite systems.Recent advances in machine learning uncover pathways to identify the waveform-damage mechanism relationship in higher-dimensional spaces for a comprehensive understanding of damage evolution.This review evaluates the state of the field,beginning with a physics-based understanding of acoustic emission waveform feature extraction,followed by a detailed overview of waveform clustering,labeling,and error analysis strategies.Fundamental requirements for damage mechanism identification in any machine learning framework,including those currently in use,under development,and yet to be explored,are discussed.展开更多
In this work,we demonstrate that damage mechanism identification from acoustic emission(AE)signals generated in minicomposites with elastically similar constituents is possible.AE waveforms were generated by SiC/SiC c...In this work,we demonstrate that damage mechanism identification from acoustic emission(AE)signals generated in minicomposites with elastically similar constituents is possible.AE waveforms were generated by SiC/SiC ceramic matrix minicomposites(CMCs)loaded under uniaxial tension and recorded by four sensors(two models with each model placed at two ends).Signals were encoded with a modified partial power scheme and subsequently partitioned through spectral clustering.Matrix cracking and fiber failure were identified based on the frequency information contained in the AE event they produced,despite the similar constituent elastic properties of the matrix and fiber.Importantly,the resultant identification of AE events closely followed CMC damage chronology,wherein early matrix cracking is later followed by fiber breaks,even though the approach is fully domain-knowledge agnostic.Additionally,the partitions were highly precise across both the model and location of the sensors,and the partitioning was repeatable.The presented approach is promising for CMCs and other composite systems with elastically similar constituents.展开更多
文摘描述了大屏幕液晶电视图像画质的改善。在屏幕尺寸上已经超过C R T的液晶电视,即使屏幕尺寸达到60英寸,也可以实现全屏100%亮度的高水准。另一方面,高亮度和大尺寸屏幕使液晶电视在图像画质方面存在的问题变得更加明显,因此应当对它们加以解决。例如可见轮廓、动画模糊以及M PEG压缩引起的图像压缩失真及其补偿算法都将在本文中描述。
基金CM.and B.S.gratefully acknowledge financial support from the NASA Spce Tochnology Gaduate Research Opportunites Felowship(Grants:8ONSSC19K1164 and 8ONSSC17K0084,SD.and T.MP.gratefully acknowiedge fnanchl support from the Natonal Sclonce Found ation Uward 1984641)patt of the HDR IDEAS Insatute.The authors additonally thank Aaron Engel for the suggeston for this project and Dr Neal Brodnik for an Introduction to tSNE。
文摘Damage mechanism identification has scientific and practical ramifications for the structural health monitoring,design,and application of composite systems.Recent advances in machine learning uncover pathways to identify the waveform-damage mechanism relationship in higher-dimensional spaces for a comprehensive understanding of damage evolution.This review evaluates the state of the field,beginning with a physics-based understanding of acoustic emission waveform feature extraction,followed by a detailed overview of waveform clustering,labeling,and error analysis strategies.Fundamental requirements for damage mechanism identification in any machine learning framework,including those currently in use,under development,and yet to be explored,are discussed.
基金C.M.and B.S.gratefully acknowledge financial support from the NASA Space Technology Research Grant Program(Grants:80NSSC19K1164 and 80NSSC17K0084)S.D.and T.M.P.gratefully acknowledge financial support from the National Science Foundation(Award:1934641)as part of the HDR IDEAS2 Institute.The authors thank Abed Musaffar for creating the CAD schematic in Fig.1a and thank Dr.Neal Brodnik for a detailed introduction to t-SNE.
文摘In this work,we demonstrate that damage mechanism identification from acoustic emission(AE)signals generated in minicomposites with elastically similar constituents is possible.AE waveforms were generated by SiC/SiC ceramic matrix minicomposites(CMCs)loaded under uniaxial tension and recorded by four sensors(two models with each model placed at two ends).Signals were encoded with a modified partial power scheme and subsequently partitioned through spectral clustering.Matrix cracking and fiber failure were identified based on the frequency information contained in the AE event they produced,despite the similar constituent elastic properties of the matrix and fiber.Importantly,the resultant identification of AE events closely followed CMC damage chronology,wherein early matrix cracking is later followed by fiber breaks,even though the approach is fully domain-knowledge agnostic.Additionally,the partitions were highly precise across both the model and location of the sensors,and the partitioning was repeatable.The presented approach is promising for CMCs and other composite systems with elastically similar constituents.
