Pub Date : 2019-01-01DOI: 10.11972/j.issn.1001-9014.2019.03.018
Wei Yang, Kun Hou, Yunsheng Zhao
{"title":"The study on polarized spectral identification of dry plants and bare soils based on histogram of oriented gradient","authors":"Wei Yang, Kun Hou, Yunsheng Zhao","doi":"10.11972/j.issn.1001-9014.2019.03.018","DOIUrl":"https://doi.org/10.11972/j.issn.1001-9014.2019.03.018","url":null,"abstract":"","PeriodicalId":50181,"journal":{"name":"红外与毫米波学报","volume":"38 1","pages":"03365"},"PeriodicalIF":0.7,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66393795","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-01-01DOI: 10.11972/J.ISSN.1001-9014.2019.01.006
Chong-Jian Wang, Xiaowei Sun, Kehu Yang
Active millimeter wave imaging ( AMWI) is an efficient way to detect dangerous objects concealed under clothes. However,because the images acquired by AMWI are often obscure and some of concealed objects are small in size,the automatic detection and localization of the objects remain as a challenging problem. Yao first employed convolutional neural networks( CNNs) and used a dense sliding window method to detect concealed objects. In this paper,the author presents two improvements over Yao 's work: 1) Using contextual information to suppress interference and improve detection probability; 2) Using a two-step search method instead of exhaustive search to reduce the computational complexity. To reduce the computational complexity,the author first uses a CNN in vertical direction to filter the interference and obtain the vertical position of the concealed object,then uses another CNN to determine the horizontal position of the concealed object. To make use of big window containing contextual information,the author uses IoG ( intersection-over-ground-truth) instead of IoU ( Intersection-over-Union) to define positive and negative samples in training and testing process. Experimental results show that the proposed method will make the length of computational time reduced to about 30% of that of the exhaustive search while achieving better detection performance.
{"title":"A low-complexity method for concealed object detection in active millimeter-wave images","authors":"Chong-Jian Wang, Xiaowei Sun, Kehu Yang","doi":"10.11972/J.ISSN.1001-9014.2019.01.006","DOIUrl":"https://doi.org/10.11972/J.ISSN.1001-9014.2019.01.006","url":null,"abstract":"Active millimeter wave imaging ( AMWI) is an efficient way to detect dangerous objects concealed under clothes. However,because the images acquired by AMWI are often obscure and some of concealed objects are small in size,the automatic detection and localization of the objects remain as a challenging problem. Yao first employed convolutional neural networks( CNNs) and used a dense sliding window method to detect concealed objects. In this paper,the author presents two improvements over Yao 's work: 1) Using contextual information to suppress interference and improve detection probability; 2) Using a two-step search method instead of exhaustive search to reduce the computational complexity. To reduce the computational complexity,the author first uses a CNN in vertical direction to filter the interference and obtain the vertical position of the concealed object,then uses another CNN to determine the horizontal position of the concealed object. To make use of big window containing contextual information,the author uses IoG ( intersection-over-ground-truth) instead of IoU ( Intersection-over-Union) to define positive and negative samples in training and testing process. Experimental results show that the proposed method will make the length of computational time reduced to about 30% of that of the exhaustive search while achieving better detection performance.","PeriodicalId":50181,"journal":{"name":"红外与毫米波学报","volume":"38 1","pages":"0132"},"PeriodicalIF":0.7,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66393422","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-01-01DOI: 10.11972/j.issn.1001-9014.2019.01.009
Xiaohang Pan, Hao Xu, Wei-Wei Yu, H. Shen, J. Hao, Yan Sun, Yue Shen, Xiangjian Meng, N. Dai
In recent years,Metamaterials,artificial electromagnetic materials that are constructed by subwavelength units,have demonstrated unusual abilities to manipulate electromagnetic waves and promised many potential applications. One of the most intriguing applications of metamaterials is to function as high performance absorbing medium. In this work,a new type of plasmonic flexible metasurfacebased super-absorber for Terahertz waves is designed,fabricated and characterized. Dependences of absorption on the optical properties of component materials and geometric parameters are optimized by full-wave numerical simulations,and then confirmed by experiments. Experimental results show that an absorption peak value of 99% is obtained at the frequency of 3 THz,which are in good agreement with numerical simulations.
{"title":"Flexible matesurface-based Terahertz super-absorber","authors":"Xiaohang Pan, Hao Xu, Wei-Wei Yu, H. Shen, J. Hao, Yan Sun, Yue Shen, Xiangjian Meng, N. Dai","doi":"10.11972/j.issn.1001-9014.2019.01.009","DOIUrl":"https://doi.org/10.11972/j.issn.1001-9014.2019.01.009","url":null,"abstract":"In recent years,Metamaterials,artificial electromagnetic materials that are constructed by subwavelength units,have demonstrated unusual abilities to manipulate electromagnetic waves and promised many potential applications. One of the most intriguing applications of metamaterials is to function as high performance absorbing medium. In this work,a new type of plasmonic flexible metasurfacebased super-absorber for Terahertz waves is designed,fabricated and characterized. Dependences of absorption on the optical properties of component materials and geometric parameters are optimized by full-wave numerical simulations,and then confirmed by experiments. Experimental results show that an absorption peak value of 99% is obtained at the frequency of 3 THz,which are in good agreement with numerical simulations.","PeriodicalId":50181,"journal":{"name":"红外与毫米波学报","volume":"38 1","pages":"0150"},"PeriodicalIF":0.7,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66393561","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-01-01DOI: 10.11972/J.ISSN.1001-9014.2019.01.012
Shuai Li, Zijie Dai, Xiang Gao, Tao Zhan, Zhao Delong, Cheng Gong, Weiwei Liu
High-performance terahertz functional devices have great significance in the generation,transmission and detection of terahertz waves. This paper reports a Kagome-type low-loss terahertz waveguide and its imaging applications. Firstly,anti-resonant waveguide theory was used to design a Kagome terahertz waveguide with low loss transmission at 0. 1 THz,which has a theoretical loss as low as 0. 012 cm -1 . Secondly,the waveguide was fabricated by 3D printing technology. The experimental loss is 0. 015 3 cm ,and the beam divergence angle at the end of the waveguide is about 6 ± 0. 5 degree. Finally,a reconfigurable terahertz imaging system was set up based on the waveguide,which realizes reflection and transmission imaging for a hidden blade and ore respectively. This technology has great application prospects in the underground long-distance exploration.
{"title":"Low-loss terahertz waveguide and its imaging application","authors":"Shuai Li, Zijie Dai, Xiang Gao, Tao Zhan, Zhao Delong, Cheng Gong, Weiwei Liu","doi":"10.11972/J.ISSN.1001-9014.2019.01.012","DOIUrl":"https://doi.org/10.11972/J.ISSN.1001-9014.2019.01.012","url":null,"abstract":"High-performance terahertz functional devices have great significance in the generation,transmission and detection of terahertz waves. This paper reports a Kagome-type low-loss terahertz waveguide and its imaging applications. Firstly,anti-resonant waveguide theory was used to design a Kagome terahertz waveguide with low loss transmission at 0. 1 THz,which has a theoretical loss as low as 0. 012 cm -1 . Secondly,the waveguide was fabricated by 3D printing technology. The experimental loss is 0. 015 3 cm ,and the beam divergence angle at the end of the waveguide is about 6 ± 0. 5 degree. Finally,a reconfigurable terahertz imaging system was set up based on the waveguide,which realizes reflection and transmission imaging for a hidden blade and ore respectively. This technology has great application prospects in the underground long-distance exploration.","PeriodicalId":50181,"journal":{"name":"红外与毫米波学报","volume":"38 1","pages":"0168"},"PeriodicalIF":0.7,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66393657","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-01-01DOI: 10.11972/j.issn.1001-9014.2019.01.019
Li Zhu, Jing Zhang, Yingxia Fu, Hui Shen, Shouming Zhang, Xianggong Hong
Infrared thermal image region of interest ( ROI) extraction has important significance for fault detection,target tracking and so on. In order to solve the problems of many infrared thermal image disturbances,artificial markers and low accuracy,a ROI of infrared thermal image extraction algorithm based on fusion of multi-modal feature map is proposed. Multi-modal feature maps are constructed by contrast,entropy,and gradient features,and region filling is performed to achieve ROI extraction. New algorithm is applied to actual collected photovoltaic solar panel image. Simulation results show that the proposed algorithm has high average precision ( 93. 0553% ) ,high average recall ( 90. 2841% ) , F1 index and J index are better than Grab Cut,less artificial marks,etc. . It can be effectively used for ROI extraction of infrared thermal images.
{"title":"Infrared thermal image ROI extraction algorithm based on fusion of multi-modal feature maps","authors":"Li Zhu, Jing Zhang, Yingxia Fu, Hui Shen, Shouming Zhang, Xianggong Hong","doi":"10.11972/j.issn.1001-9014.2019.01.019","DOIUrl":"https://doi.org/10.11972/j.issn.1001-9014.2019.01.019","url":null,"abstract":"Infrared thermal image region of interest ( ROI) extraction has important significance for fault detection,target tracking and so on. In order to solve the problems of many infrared thermal image disturbances,artificial markers and low accuracy,a ROI of infrared thermal image extraction algorithm based on fusion of multi-modal feature map is proposed. Multi-modal feature maps are constructed by contrast,entropy,and gradient features,and region filling is performed to achieve ROI extraction. New algorithm is applied to actual collected photovoltaic solar panel image. Simulation results show that the proposed algorithm has high average precision ( 93. 0553% ) ,high average recall ( 90. 2841% ) , F1 index and J index are better than Grab Cut,less artificial marks,etc. . It can be effectively used for ROI extraction of infrared thermal images.","PeriodicalId":50181,"journal":{"name":"红外与毫米波学报","volume":"38 1","pages":"01125"},"PeriodicalIF":0.7,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66393772","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-01-01DOI: 10.11972/J.ISSN.1001-9014.2019.06.007
Wang Long, Yin Zeng-shan, Kong Xin-Wei, Shin-Yu Shen
Inter-satellite laser links have the advantages of high data rate,long transmission distance and low probability of detection/intercept. It has become an important trend in satellite technology. The inter-satellite point-to-point laser links are high mobility,and have narrow beam width,which bring challenges to the PAT pro⁃ cesses. Due to their high computational complexity and large delay,the existing free space networks(FSO)topol⁃ ogy control strategies cannot be directly applied to satellite networks. In this article,an algebraic connectivity based network dynamic topology control scheme is proposed. With distributed construction and enhancement pro⁃ cess,the network dynamic reconfiguration is accomplished. A modified edge perturbation method is developed, and proved to have lower computational complexity than existing methods. The scheme is distributed,self-orga⁃ nized and near real-time,it which meets the requirements of dynamic topology control well and will contribute to building operationally responsive space(ORS)satellite networks.
{"title":"Robust dynamic topology control for ORS satellite laser communication networks","authors":"Wang Long, Yin Zeng-shan, Kong Xin-Wei, Shin-Yu Shen","doi":"10.11972/J.ISSN.1001-9014.2019.06.007","DOIUrl":"https://doi.org/10.11972/J.ISSN.1001-9014.2019.06.007","url":null,"abstract":"Inter-satellite laser links have the advantages of high data rate,long transmission distance and low probability of detection/intercept. It has become an important trend in satellite technology. The inter-satellite point-to-point laser links are high mobility,and have narrow beam width,which bring challenges to the PAT pro⁃ cesses. Due to their high computational complexity and large delay,the existing free space networks(FSO)topol⁃ ogy control strategies cannot be directly applied to satellite networks. In this article,an algebraic connectivity based network dynamic topology control scheme is proposed. With distributed construction and enhancement pro⁃ cess,the network dynamic reconfiguration is accomplished. A modified edge perturbation method is developed, and proved to have lower computational complexity than existing methods. The scheme is distributed,self-orga⁃ nized and near real-time,it which meets the requirements of dynamic topology control well and will contribute to building operationally responsive space(ORS)satellite networks.","PeriodicalId":50181,"journal":{"name":"红外与毫米波学报","volume":"38 1","pages":"706"},"PeriodicalIF":0.7,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66394256","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-01-01DOI: 10.11972/J.ISSN.1001-9014.2019.06.004
Cao Yi-chao, Chen Qiang, Zhang Chen, Song Tao, Huang Jie, Hu Qiao, Liu Diwei, Wang Wei, Hu Min, Zhong Renbin, Shen Hao
{"title":"Investigations on an improved transmission line for THz DNP-NMR spectroscopy","authors":"Cao Yi-chao, Chen Qiang, Zhang Chen, Song Tao, Huang Jie, Hu Qiao, Liu Diwei, Wang Wei, Hu Min, Zhong Renbin, Shen Hao","doi":"10.11972/J.ISSN.1001-9014.2019.06.004","DOIUrl":"https://doi.org/10.11972/J.ISSN.1001-9014.2019.06.004","url":null,"abstract":"","PeriodicalId":50181,"journal":{"name":"红外与毫米波学报","volume":"38 1","pages":"690-694"},"PeriodicalIF":0.7,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66394243","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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