Pub Date : 2015-10-29DOI: 10.1109/APSAR.2015.7306207
Venkata Kishore Kothapudi, Vijay Kumar
In this letter the design and simulation of an 0.43GHz P/UHF band microstrip patch antenna as single element, 2, 4, 8 & 16-element linear array using RT/duroid 6002 substrate was proposed. An inter-element spacing of 0.73λ for limited scan angle coverage. Wind profiling radar operating in Doppler beam swinging mode and spaced antenna drift technique mode needs to have a large aperture antenna array in order to get the narrow pencil beam is required for wind speed and direction accuracy. To meet the above requirements a microstrip patch antenna single element is used to design a 2, 4, 8 & 16-element linear antenna array for Tropospheric Wind Profiling Radar Operating at 0.43GHz. Conception details and simulation results are also given for the both single element & 16-element linear antenna array. The designed and simulated results are presented. A full wave electromagnetic simulator zeland IE3D V12.02 is used to validate the design approach. The simulated results below present are valid over the 0.43GHz band and the simulated parameters contains the VSWR, Return loss, impedance, gain, directivity, efficiency and elevation gain patterns.
{"title":"Design of 0.73λ inter-element spacing linear array for 0.43GHz P/UHF-band tropospheric radar wind profiler","authors":"Venkata Kishore Kothapudi, Vijay Kumar","doi":"10.1109/APSAR.2015.7306207","DOIUrl":"https://doi.org/10.1109/APSAR.2015.7306207","url":null,"abstract":"In this letter the design and simulation of an 0.43GHz P/UHF band microstrip patch antenna as single element, 2, 4, 8 & 16-element linear array using RT/duroid 6002 substrate was proposed. An inter-element spacing of 0.73λ for limited scan angle coverage. Wind profiling radar operating in Doppler beam swinging mode and spaced antenna drift technique mode needs to have a large aperture antenna array in order to get the narrow pencil beam is required for wind speed and direction accuracy. To meet the above requirements a microstrip patch antenna single element is used to design a 2, 4, 8 & 16-element linear antenna array for Tropospheric Wind Profiling Radar Operating at 0.43GHz. Conception details and simulation results are also given for the both single element & 16-element linear antenna array. The designed and simulated results are presented. A full wave electromagnetic simulator zeland IE3D V12.02 is used to validate the design approach. The simulated results below present are valid over the 0.43GHz band and the simulated parameters contains the VSWR, Return loss, impedance, gain, directivity, efficiency and elevation gain patterns.","PeriodicalId":350698,"journal":{"name":"2015 IEEE 5th Asia-Pacific Conference on Synthetic Aperture Radar (APSAR)","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134066026","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2015-10-29DOI: 10.1109/APSAR.2015.7306168
C. Kee, F. Hu, Chao‐Fu Wang, T. Chia
Generating high resolution SAR image of an object typically requires its scattered field data over a large number of aspect angles and frequencies, which is very time consuming to obtain. This paper discusses the implementation of the PO-SBR method on GPU to efficiently compute the massive scattered field data required for SAR application.
{"title":"Accelerating PO-SBR for SAR application","authors":"C. Kee, F. Hu, Chao‐Fu Wang, T. Chia","doi":"10.1109/APSAR.2015.7306168","DOIUrl":"https://doi.org/10.1109/APSAR.2015.7306168","url":null,"abstract":"Generating high resolution SAR image of an object typically requires its scattered field data over a large number of aspect angles and frequencies, which is very time consuming to obtain. This paper discusses the implementation of the PO-SBR method on GPU to efficiently compute the massive scattered field data required for SAR application.","PeriodicalId":350698,"journal":{"name":"2015 IEEE 5th Asia-Pacific Conference on Synthetic Aperture Radar (APSAR)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130944069","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2015-10-29DOI: 10.1109/APSAR.2015.7306283
M. Santoro, U. Wegmuller, A. Wiesmann, C. Lamarche, S. Bontemps, P. Defourny, O. Arino
C-band observations of the SAR backscatter from the Envisat ASAR (2005-2012) and Sentinel-1 (2014-ongoing) instruments are reviewed to understand their suitability to detect of open water bodies. The temporal variability (TV) and the minimum backscatter (MB) of ASAR backscatter were fed to a simple algorithm based on thresholds to obtain an indicator of water bodies globally with a spatial resolution of 150 m. Confusion occurred either in the case of irregular acquisitions of ASAR images or in cold and arid regions where the multi-temporal metrics based on the multi-year ASAR dataset were often similar to values obtained over open water bodies. With Sentinel-1, there are clear chances to improve the mapping of water bodies considering the dual-polarization capability, the higher spatial resolution and the more consistent observation strategy. First examples from a test site in Sweden show that average and minimum cross-polarized backscatter are suited for water body mapping.
{"title":"Assessing Envisat ASAR and Sentinel-1 multi-temporal observations to map open water bodies","authors":"M. Santoro, U. Wegmuller, A. Wiesmann, C. Lamarche, S. Bontemps, P. Defourny, O. Arino","doi":"10.1109/APSAR.2015.7306283","DOIUrl":"https://doi.org/10.1109/APSAR.2015.7306283","url":null,"abstract":"C-band observations of the SAR backscatter from the Envisat ASAR (2005-2012) and Sentinel-1 (2014-ongoing) instruments are reviewed to understand their suitability to detect of open water bodies. The temporal variability (TV) and the minimum backscatter (MB) of ASAR backscatter were fed to a simple algorithm based on thresholds to obtain an indicator of water bodies globally with a spatial resolution of 150 m. Confusion occurred either in the case of irregular acquisitions of ASAR images or in cold and arid regions where the multi-temporal metrics based on the multi-year ASAR dataset were often similar to values obtained over open water bodies. With Sentinel-1, there are clear chances to improve the mapping of water bodies considering the dual-polarization capability, the higher spatial resolution and the more consistent observation strategy. First examples from a test site in Sweden show that average and minimum cross-polarized backscatter are suited for water body mapping.","PeriodicalId":350698,"journal":{"name":"2015 IEEE 5th Asia-Pacific Conference on Synthetic Aperture Radar (APSAR)","volume":"72 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130967645","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2015-10-29DOI: 10.1109/APSAR.2015.7306156
Shunjun Wei, Xiaoling Zhang, Jun Shi, H. Kebin, Zhang Bojun
Due to platform uncertain motion, the trajectory of airborne millimeter-wave interferometric synthetic aperture radar (MMW-InSAR) usually demonstrates highly non-linear associated with position errors. Hence, motion compensation must be considered for airborne MMW-InSAR high resolution imaging. In this paper, a back projection (BP) autofocusing algorithm via maximum sharpness is presented for MMW-InSAR interferometry in the case of complex trajectory with motion errors. In the scheme, the MMW-INSAR data is focusing by BP along the complex trajectory, and the azimuth phase errors is estimated from the dominant scatterering area using an iterative procedure, which aims to maximizing the InSAR image sharpness. The effectiveness of the proposed method is testified by the experiment data, the results demonstrate that it can improve MMW-InSAR imaging quality compared with conventional BP algorithm in the case of complex trajectory.
{"title":"Complex trajectory millimeter-wave InSAR interferometry using maximum sharpness BP autofocusing algorithm","authors":"Shunjun Wei, Xiaoling Zhang, Jun Shi, H. Kebin, Zhang Bojun","doi":"10.1109/APSAR.2015.7306156","DOIUrl":"https://doi.org/10.1109/APSAR.2015.7306156","url":null,"abstract":"Due to platform uncertain motion, the trajectory of airborne millimeter-wave interferometric synthetic aperture radar (MMW-InSAR) usually demonstrates highly non-linear associated with position errors. Hence, motion compensation must be considered for airborne MMW-InSAR high resolution imaging. In this paper, a back projection (BP) autofocusing algorithm via maximum sharpness is presented for MMW-InSAR interferometry in the case of complex trajectory with motion errors. In the scheme, the MMW-INSAR data is focusing by BP along the complex trajectory, and the azimuth phase errors is estimated from the dominant scatterering area using an iterative procedure, which aims to maximizing the InSAR image sharpness. The effectiveness of the proposed method is testified by the experiment data, the results demonstrate that it can improve MMW-InSAR imaging quality compared with conventional BP algorithm in the case of complex trajectory.","PeriodicalId":350698,"journal":{"name":"2015 IEEE 5th Asia-Pacific Conference on Synthetic Aperture Radar (APSAR)","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130979464","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2015-10-29DOI: 10.1109/APSAR.2015.7306157
Seok Kim, Jiwoong Yu, M. Ka
In this paper, we describe a simple method for SAR image synthesis of a realistic target model using the general purpose EM simulator like FEKO and demonstrate the steps by processing the simulated SAR raw data with chirp-scaling algorithm (CSA), which is one of the most widely used SAR image formation algorithms. This method can benefit us many advantages like performance evaluation for target detection, estimation and target recognition with realistic target model in a cost-and-time effective way.
{"title":"SAR image synthesis with chirp scaling algorithm of 3D CAD model using EM simulator","authors":"Seok Kim, Jiwoong Yu, M. Ka","doi":"10.1109/APSAR.2015.7306157","DOIUrl":"https://doi.org/10.1109/APSAR.2015.7306157","url":null,"abstract":"In this paper, we describe a simple method for SAR image synthesis of a realistic target model using the general purpose EM simulator like FEKO and demonstrate the steps by processing the simulated SAR raw data with chirp-scaling algorithm (CSA), which is one of the most widely used SAR image formation algorithms. This method can benefit us many advantages like performance evaluation for target detection, estimation and target recognition with realistic target model in a cost-and-time effective way.","PeriodicalId":350698,"journal":{"name":"2015 IEEE 5th Asia-Pacific Conference on Synthetic Aperture Radar (APSAR)","volume":"37 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114183696","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2015-10-29DOI: 10.1109/APSAR.2015.7306219
Mingzhe Zhang, Chao Wang, Hong Zhang, Meng Liu, Lei Xie
Traditional pixel-based change detection methods are undertaken using the pixel as the research unit. These methods may give high false alarm rate and broken areas, because they don't use semantic information. In order to solve this problem, we present a novel change detection method which is based on radon transform and super-pixel segmentation. First, radon transform is used to achieve a stable difference map, and the Otsu algorithm is used to gain the initial change mask. Second, in order to reduce false alarm rate and preserve edges between changed class and unchanged class, the simple linear iterative clustering(SLIC) super-pixel segmentation is introduced into SAR image segmentation. Then, the spatial-based change detection scheme is utilized for the fusion of initial change mask and segmentation result. Two radarsat-2 images of Suzhou, China, acquired on April 9,2009 and June 15, 2010 are used for our experiment. Experiment results show that the proposed method is effective for SAR image change detection in terms of edge preservation and change detection rate.
{"title":"A novel SAR change detection based on radon transform and super-pixel segmentation","authors":"Mingzhe Zhang, Chao Wang, Hong Zhang, Meng Liu, Lei Xie","doi":"10.1109/APSAR.2015.7306219","DOIUrl":"https://doi.org/10.1109/APSAR.2015.7306219","url":null,"abstract":"Traditional pixel-based change detection methods are undertaken using the pixel as the research unit. These methods may give high false alarm rate and broken areas, because they don't use semantic information. In order to solve this problem, we present a novel change detection method which is based on radon transform and super-pixel segmentation. First, radon transform is used to achieve a stable difference map, and the Otsu algorithm is used to gain the initial change mask. Second, in order to reduce false alarm rate and preserve edges between changed class and unchanged class, the simple linear iterative clustering(SLIC) super-pixel segmentation is introduced into SAR image segmentation. Then, the spatial-based change detection scheme is utilized for the fusion of initial change mask and segmentation result. Two radarsat-2 images of Suzhou, China, acquired on April 9,2009 and June 15, 2010 are used for our experiment. Experiment results show that the proposed method is effective for SAR image change detection in terms of edge preservation and change detection rate.","PeriodicalId":350698,"journal":{"name":"2015 IEEE 5th Asia-Pacific Conference on Synthetic Aperture Radar (APSAR)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123659557","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2015-10-29DOI: 10.1109/APSAR.2015.7306270
Xiongjun Fu, Chengyan Zhang, Guangjun Cheng, M. Xie
Inverse Synthetic Aperture Radar (ISAR) has the function of remote imaging with non-cooperative targets. It has important value in application of the space target surveillance, recognition and cataloging, and satellite fault diagnosis. This paper describes multi-dimensional ISAR imaging technology in detail. Research results of real-time ISAR imaging with mono-static and multi-polarization, and bi-static ISAR imaging are presented. This paper also shows the development trends of ISAR imaging technology.
{"title":"ISAR imaging applications for orbital objects","authors":"Xiongjun Fu, Chengyan Zhang, Guangjun Cheng, M. Xie","doi":"10.1109/APSAR.2015.7306270","DOIUrl":"https://doi.org/10.1109/APSAR.2015.7306270","url":null,"abstract":"Inverse Synthetic Aperture Radar (ISAR) has the function of remote imaging with non-cooperative targets. It has important value in application of the space target surveillance, recognition and cataloging, and satellite fault diagnosis. This paper describes multi-dimensional ISAR imaging technology in detail. Research results of real-time ISAR imaging with mono-static and multi-polarization, and bi-static ISAR imaging are presented. This paper also shows the development trends of ISAR imaging technology.","PeriodicalId":350698,"journal":{"name":"2015 IEEE 5th Asia-Pacific Conference on Synthetic Aperture Radar (APSAR)","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123728231","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2015-10-29DOI: 10.1109/APSAR.2015.7306191
U. Khati, Gulab Singh
The research work presents the initial results from bistatic dual-PolInSAR TerraSAR-X/TanDEM-X data. These results are the first reported observations of forest height derived using TerraSAR-X/TanDEM-X bistatic data over Indian tropical forests. The minimization approach with three stage inversion technique is applied on the data for forest height estimation. The results show potential of X-band SAR data for forest parameter estimation. Underestimation of height in forests due to low penetration capability of X-band and overestimation of height in agricultural areas are presented in the study.
{"title":"Bistatic PolInSAR for forest height estimation: Results from TanDEM-X","authors":"U. Khati, Gulab Singh","doi":"10.1109/APSAR.2015.7306191","DOIUrl":"https://doi.org/10.1109/APSAR.2015.7306191","url":null,"abstract":"The research work presents the initial results from bistatic dual-PolInSAR TerraSAR-X/TanDEM-X data. These results are the first reported observations of forest height derived using TerraSAR-X/TanDEM-X bistatic data over Indian tropical forests. The minimization approach with three stage inversion technique is applied on the data for forest height estimation. The results show potential of X-band SAR data for forest parameter estimation. Underestimation of height in forests due to low penetration capability of X-band and overestimation of height in agricultural areas are presented in the study.","PeriodicalId":350698,"journal":{"name":"2015 IEEE 5th Asia-Pacific Conference on Synthetic Aperture Radar (APSAR)","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127245842","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2015-10-29DOI: 10.1109/APSAR.2015.7306144
Lu Junqi, Guo Yongxin
A novel aperiodic phased array for space-borne synthetic aperture Radar (SAR) is presented which has fewer active chains than a corresponding periodic phased array while maintains comparable radiation performance. The design of proposed aperiodic phased array is based on equal amplitude sparse array. Compare to other aperiodic sparse phased array antennas for space-borne SAR which have been reported before, in the design of proposed sparse array a novel `active-passive array' technology is utilized to modify the equivalent aperture current distribution, therefore the radiation performance can be improved significantly in terms of gain and sidelobe level. Simulation results show that the proposed phased array possess similar radiation performance to a periodic array while reduces the active chains number to 75%. Simplified evaluation of SAR Ambiguity-to-Signal Ratio also show that the proposed array exhibits similar performance of traditional periodic array, which is obviously better than that of conventional aperiodic sparse array. The design principle of `active-passive array' as well as associated array synthesis method are also discussed.
{"title":"Novel aperiodic phased array with reduced number of active chains for space-borne SAR","authors":"Lu Junqi, Guo Yongxin","doi":"10.1109/APSAR.2015.7306144","DOIUrl":"https://doi.org/10.1109/APSAR.2015.7306144","url":null,"abstract":"A novel aperiodic phased array for space-borne synthetic aperture Radar (SAR) is presented which has fewer active chains than a corresponding periodic phased array while maintains comparable radiation performance. The design of proposed aperiodic phased array is based on equal amplitude sparse array. Compare to other aperiodic sparse phased array antennas for space-borne SAR which have been reported before, in the design of proposed sparse array a novel `active-passive array' technology is utilized to modify the equivalent aperture current distribution, therefore the radiation performance can be improved significantly in terms of gain and sidelobe level. Simulation results show that the proposed phased array possess similar radiation performance to a periodic array while reduces the active chains number to 75%. Simplified evaluation of SAR Ambiguity-to-Signal Ratio also show that the proposed array exhibits similar performance of traditional periodic array, which is obviously better than that of conventional aperiodic sparse array. The design principle of `active-passive array' as well as associated array synthesis method are also discussed.","PeriodicalId":350698,"journal":{"name":"2015 IEEE 5th Asia-Pacific Conference on Synthetic Aperture Radar (APSAR)","volume":"195 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116697711","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2015-10-29DOI: 10.1109/APSAR.2015.7306192
Zhang Zhengjia, Chao Wang, Yixian Tang, Hong Zhang
Climate change and anthropogenic activity are changing the dynamics balance of the Qinghai-Tibet Plateau (QTP) environmental balance, which would impact the safety and stability of the infrastructure. The Qinghai-Tibet Railway (QTR) is the longest structure in the QTP, and some section of the QTR's embankment has been damaged due to the freezing and thawing of the QTP. With the high resolution SAR image, the structure of the QTR can be recognized and analyzed. In this paper, the freezing displacement and thermal dilation of the QTR has been analyzed. It is found that seasonal displacement over a range of 70mm, which may correlated with the water contend of the active layer. And the thermal dilation of the QTR has been founded and analyzed.
{"title":"Qinghai-Tibet railway thermal dilation monitoring using SAR interferometry","authors":"Zhang Zhengjia, Chao Wang, Yixian Tang, Hong Zhang","doi":"10.1109/APSAR.2015.7306192","DOIUrl":"https://doi.org/10.1109/APSAR.2015.7306192","url":null,"abstract":"Climate change and anthropogenic activity are changing the dynamics balance of the Qinghai-Tibet Plateau (QTP) environmental balance, which would impact the safety and stability of the infrastructure. The Qinghai-Tibet Railway (QTR) is the longest structure in the QTP, and some section of the QTR's embankment has been damaged due to the freezing and thawing of the QTP. With the high resolution SAR image, the structure of the QTR can be recognized and analyzed. In this paper, the freezing displacement and thermal dilation of the QTR has been analyzed. It is found that seasonal displacement over a range of 70mm, which may correlated with the water contend of the active layer. And the thermal dilation of the QTR has been founded and analyzed.","PeriodicalId":350698,"journal":{"name":"2015 IEEE 5th Asia-Pacific Conference on Synthetic Aperture Radar (APSAR)","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114728336","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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