The tunable propagation properties of 3D Dirac semimetal(DSM)-supported dielectric-loaded surface plasmons structures have been investigated in the THz regime,including the influences of the Fermi level of 3D DSM laye...The tunable propagation properties of 3D Dirac semimetal(DSM)-supported dielectric-loaded surface plasmons structures have been investigated in the THz regime,including the influences of the Fermi level of 3D DSM layer,the fiber shape and operation frequencies.The results indicate that the shape of dielectric fiber affects the hybrid mode significantly,on the condition that if ax(the semi-minor axis length of the dielectric semi-ellipse)is relatively small,the fiber shows good mode confinement and low loss simultaneously,and the figure of merit reaches more than 200.The propagation property can be manipulated in a wide range by changing the Fermi level of 3D DSM,e.g.if the Fermi level varies in the range of 0.05 eV–0.15 eV,the propagation length changes in the range of 9.073×10^(3)–2.715×10^(4)μm,and the corresponding modulation depth is 66.5%.These results are very helpful to understand the tunable mechanisms of the 3D DSM plasmonic devices,such as switchers,modulators,and sensors.展开更多
The more information obtained about the driving environment,the more ensures driving safety.Due to the complex driving environment of farmland roads,targets beside the road sometimes have an important impact on drivin...The more information obtained about the driving environment,the more ensures driving safety.Due to the complex driving environment of farmland roads,targets beside the road sometimes have an important impact on driving safety.To achieve this goal,a novel real-time detection and prediction algorithm of targets was proposed.The whole image was divided into four parts by RCM:driving region,crossroad region,roadside region,and the other region.In addition,a safety policy for every part was enforced by the algorithm,which was based mainly on the combination of the YOLACT and GPM.On this basis,a self-collected data set of 5000 test samples is used for testing.The detection accuracy of the algorithm in the data set could reach up to 90%,and the processing speed to 30.4 fps.In addition,experiments were carried out on actual farmland roads,and the results showed that the proposed algorithm was able to detect,track,and predict targets on the farmland road,and alarm to driver in time before the targets rush into the road.This study provides an important reference for the safe driving of agricultural vehicles.展开更多
基金the Natural Science Foundation of Shanghai under Grant Nos.21ZR1446500Shanghai Local College Capacity Building Project under Grant No.22010503300 and 21010503200+4 种基金the Research Funding of Shanghai Normal University under Grant No.SK202240National Natural Science Foundation of China under Grant Nos.61674106,12073018,U1931205the Funding of Shanghai Municipal Education Commission under Grant No 2019-01-07-00-02-E00032the Funding of Shanghai Municipality Science and Technology Commission under Grant No 19590746000,20070502400,YDZX20203100002498Student Research Project of Shanghai Normal University(undergraduate)under Grant No.22LKY022.
文摘The tunable propagation properties of 3D Dirac semimetal(DSM)-supported dielectric-loaded surface plasmons structures have been investigated in the THz regime,including the influences of the Fermi level of 3D DSM layer,the fiber shape and operation frequencies.The results indicate that the shape of dielectric fiber affects the hybrid mode significantly,on the condition that if ax(the semi-minor axis length of the dielectric semi-ellipse)is relatively small,the fiber shows good mode confinement and low loss simultaneously,and the figure of merit reaches more than 200.The propagation property can be manipulated in a wide range by changing the Fermi level of 3D DSM,e.g.if the Fermi level varies in the range of 0.05 eV–0.15 eV,the propagation length changes in the range of 9.073×10^(3)–2.715×10^(4)μm,and the corresponding modulation depth is 66.5%.These results are very helpful to understand the tunable mechanisms of the 3D DSM plasmonic devices,such as switchers,modulators,and sensors.
基金supported by Beijing Jiaotong University(C18A800090)China North Vehicle Research Institute.All the support from the above organizations is gratefully acknowledged.
文摘The more information obtained about the driving environment,the more ensures driving safety.Due to the complex driving environment of farmland roads,targets beside the road sometimes have an important impact on driving safety.To achieve this goal,a novel real-time detection and prediction algorithm of targets was proposed.The whole image was divided into four parts by RCM:driving region,crossroad region,roadside region,and the other region.In addition,a safety policy for every part was enforced by the algorithm,which was based mainly on the combination of the YOLACT and GPM.On this basis,a self-collected data set of 5000 test samples is used for testing.The detection accuracy of the algorithm in the data set could reach up to 90%,and the processing speed to 30.4 fps.In addition,experiments were carried out on actual farmland roads,and the results showed that the proposed algorithm was able to detect,track,and predict targets on the farmland road,and alarm to driver in time before the targets rush into the road.This study provides an important reference for the safe driving of agricultural vehicles.
