Pub Date : 2021-10-06DOI: 10.1109/RFID-TA53372.2021.9617235
G. Casula
This paper summarizes the activities on RFID done during the last 2 years at the University of Cagliari, describing the advancements in the field and the collaborations established with other institutions. In particular, our main recent activities dealing with RFIDs are the following: study and exploit the advantages of SIW technology in the design of wearable RFID tags operating in the European UHF band, aiming for high isolation from the human body and high robustness with respect to the antenna-body distance variation, while maintaining a reasonably small size; overcome the very limited performance of epidermal antennas, due to the presence of the lossy body, which is cause of strong electromagnetic interactions, by using an appropriate configuration to obtain a platform tolerant epidermal antenna; investigate the possibility of designing fully 3D Printable RFID tags effectively using conductive filaments and polylactic acid substrates.
{"title":"Recent Developments in RFID activities at UniCa","authors":"G. Casula","doi":"10.1109/RFID-TA53372.2021.9617235","DOIUrl":"https://doi.org/10.1109/RFID-TA53372.2021.9617235","url":null,"abstract":"This paper summarizes the activities on RFID done during the last 2 years at the University of Cagliari, describing the advancements in the field and the collaborations established with other institutions. In particular, our main recent activities dealing with RFIDs are the following: study and exploit the advantages of SIW technology in the design of wearable RFID tags operating in the European UHF band, aiming for high isolation from the human body and high robustness with respect to the antenna-body distance variation, while maintaining a reasonably small size; overcome the very limited performance of epidermal antennas, due to the presence of the lossy body, which is cause of strong electromagnetic interactions, by using an appropriate configuration to obtain a platform tolerant epidermal antenna; investigate the possibility of designing fully 3D Printable RFID tags effectively using conductive filaments and polylactic acid substrates.","PeriodicalId":212607,"journal":{"name":"2021 IEEE International Conference on RFID Technology and Applications (RFID-TA)","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126563795","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 : 2021-10-06DOI: 10.1109/RFID-TA53372.2021.9617406
Charles A. Lynch, Ajibayo O. Adeyeye, A. Eid, J. Hester, M. Tentzeris
With the promise of the massive deployment of 5G/mm-Wave technologies, low-maintenance and highly scalable wireless systems are desirable to meet the needs of the next generation IoT systems. Mm-Wave backscattering devices present great potential for IoT systems with their compact form factors, minimalist design, and available spectrum. This paper provides a review of the current state-of-the-art in semi-passive RFID/mmID tag technology, non-line-of-sight (NLOS) repeater architecture, and 5G/mm-Wave energy harvesting enabling low-latency wireless communication, precise localization, long-range capabilities, dense wireless sensor networks, and powering these next generation ultra-low-power RFID systems through the 5G wireless power-grid.
{"title":"5G/mm-Wave Next Generation RFID Systems for Future IoT Applications","authors":"Charles A. Lynch, Ajibayo O. Adeyeye, A. Eid, J. Hester, M. Tentzeris","doi":"10.1109/RFID-TA53372.2021.9617406","DOIUrl":"https://doi.org/10.1109/RFID-TA53372.2021.9617406","url":null,"abstract":"With the promise of the massive deployment of 5G/mm-Wave technologies, low-maintenance and highly scalable wireless systems are desirable to meet the needs of the next generation IoT systems. Mm-Wave backscattering devices present great potential for IoT systems with their compact form factors, minimalist design, and available spectrum. This paper provides a review of the current state-of-the-art in semi-passive RFID/mmID tag technology, non-line-of-sight (NLOS) repeater architecture, and 5G/mm-Wave energy harvesting enabling low-latency wireless communication, precise localization, long-range capabilities, dense wireless sensor networks, and powering these next generation ultra-low-power RFID systems through the 5G wireless power-grid.","PeriodicalId":212607,"journal":{"name":"2021 IEEE International Conference on RFID Technology and Applications (RFID-TA)","volume":"58 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130642632","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 : 2021-10-06DOI: 10.1109/RFID-TA53372.2021.9617271
Ishita Aggarwal, M. Tripathy, S. Pandey, A. Mittal
A miniaturized microstrip fed folded dipole antenna for RFID applications has been proposed. Two RFID resonance frequencies of 2.4 and 5.8 GHz are accommodated by the antenna. The simulated reflection coefficients are −13.4 dB at 2.4 GHz (2.28 to 2.49 GHz) and −38.5 dB at 5.8 GHz (5.4 to 6.6 GHz). The antenna design is simple, and it provides better impedance matching, and constant omnidirectional radiation pattern. The proposed antennas dimensions are optimized to get the best results at the desired band.
{"title":"A Dual band Monopole Antenna For RFID Applications","authors":"Ishita Aggarwal, M. Tripathy, S. Pandey, A. Mittal","doi":"10.1109/RFID-TA53372.2021.9617271","DOIUrl":"https://doi.org/10.1109/RFID-TA53372.2021.9617271","url":null,"abstract":"A miniaturized microstrip fed folded dipole antenna for RFID applications has been proposed. Two RFID resonance frequencies of 2.4 and 5.8 GHz are accommodated by the antenna. The simulated reflection coefficients are −13.4 dB at 2.4 GHz (2.28 to 2.49 GHz) and −38.5 dB at 5.8 GHz (5.4 to 6.6 GHz). The antenna design is simple, and it provides better impedance matching, and constant omnidirectional radiation pattern. The proposed antennas dimensions are optimized to get the best results at the desired band.","PeriodicalId":212607,"journal":{"name":"2021 IEEE International Conference on RFID Technology and Applications (RFID-TA)","volume":"95 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132250005","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 : 2021-10-06DOI: 10.1109/RFID-TA53372.2021.9617275
G. Paolini, F. Benassi, D. Masotti, A. Costanzo
This paper presents the latest works that have been carried on at the University of Bologna, Italy, in the last years related to radiofrequency identification (RFID) and wireless power transfer (WPT) topics. The main themes that have been touched are related to custom systems having practical applications in the biomedical and the industrial sectors. In particular, the focus has been put on an RFID indoor localization system exploiting the monopulse radar technique, a microfluidic sensor for biological fluids detection, and a WPT system for predictive maintenance in industrial applications, in particular in the automotive field.
{"title":"Recent Developments of RFID and WPT Technologies for Biomedical and Industrial Applications at the University of Bologna","authors":"G. Paolini, F. Benassi, D. Masotti, A. Costanzo","doi":"10.1109/RFID-TA53372.2021.9617275","DOIUrl":"https://doi.org/10.1109/RFID-TA53372.2021.9617275","url":null,"abstract":"This paper presents the latest works that have been carried on at the University of Bologna, Italy, in the last years related to radiofrequency identification (RFID) and wireless power transfer (WPT) topics. The main themes that have been touched are related to custom systems having practical applications in the biomedical and the industrial sectors. In particular, the focus has been put on an RFID indoor localization system exploiting the monopulse radar technique, a microfluidic sensor for biological fluids detection, and a WPT system for predictive maintenance in industrial applications, in particular in the automotive field.","PeriodicalId":212607,"journal":{"name":"2021 IEEE International Conference on RFID Technology and Applications (RFID-TA)","volume":"133 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132329964","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 : 2021-10-06DOI: 10.1109/RFID-TA53372.2021.9617398
N. Barbot, E. Perret
This paper presents a fair comparison between the read range of chipless RFID in co-polarization and cross-polarization in real environments. This comparison is a direct consequence of the bound on the read range for the chipless technology presented in [1]. The approach is based on an analytical model and validated by simulations and measurements. Results are mainly function of the considered residual environment. In static environments (such as anechoic chambers), co-polarization offers the highest read range due to the higher Radar Cross-Section (RCS) of the resonators with identical residual environments. However in dynamic environments (which include all real environments), cross-polarization is more robust since, even if resonators RCS is 6 dB lower than co-polarized tags, the associated residual environment is 10 dB lower. Thus read range in cross-polarization outperforms by a factor of 26% the one obtained in co-polarization in almost all real applications.
{"title":"Impact of the Polarization over the Read Range in Chipless RFID","authors":"N. Barbot, E. Perret","doi":"10.1109/RFID-TA53372.2021.9617398","DOIUrl":"https://doi.org/10.1109/RFID-TA53372.2021.9617398","url":null,"abstract":"This paper presents a fair comparison between the read range of chipless RFID in co-polarization and cross-polarization in real environments. This comparison is a direct consequence of the bound on the read range for the chipless technology presented in [1]. The approach is based on an analytical model and validated by simulations and measurements. Results are mainly function of the considered residual environment. In static environments (such as anechoic chambers), co-polarization offers the highest read range due to the higher Radar Cross-Section (RCS) of the resonators with identical residual environments. However in dynamic environments (which include all real environments), cross-polarization is more robust since, even if resonators RCS is 6 dB lower than co-polarized tags, the associated residual environment is 10 dB lower. Thus read range in cross-polarization outperforms by a factor of 26% the one obtained in co-polarization in almost all real applications.","PeriodicalId":212607,"journal":{"name":"2021 IEEE International Conference on RFID Technology and Applications (RFID-TA)","volume":"43 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131090053","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 : 2021-10-06DOI: 10.1109/RFID-TA53372.2021.9617297
Konstantinos Skyvalakis, Evangelos Giannelos, Emmanouil Andrianakis, A. Bletsas
This work puts forth elliptical direction of arrival (DoA) estimation and localization, using phase-based, narrowband measurements. The method exploits a multistatic architecture, where illuminating and receiving antennas are placed in the same line, perhaps in sharp contrast to conventional wisdom. Ambiguities inherent in phase measurements are analytically addressed. Experimental results with Gen2 UHF RFID tags show similar performance in terms of DoA estimation compared to the MUSIC algorithm. In terms of localization accuracy, the proposed method outperformed state-of-the-art algorithms in all cases, offering mean absolute localization error as small as 9 cm, at the expense of additional effort for calibration.
{"title":"Elliptical DoA Estimation & Localization","authors":"Konstantinos Skyvalakis, Evangelos Giannelos, Emmanouil Andrianakis, A. Bletsas","doi":"10.1109/RFID-TA53372.2021.9617297","DOIUrl":"https://doi.org/10.1109/RFID-TA53372.2021.9617297","url":null,"abstract":"This work puts forth elliptical direction of arrival (DoA) estimation and localization, using phase-based, narrowband measurements. The method exploits a multistatic architecture, where illuminating and receiving antennas are placed in the same line, perhaps in sharp contrast to conventional wisdom. Ambiguities inherent in phase measurements are analytically addressed. Experimental results with Gen2 UHF RFID tags show similar performance in terms of DoA estimation compared to the MUSIC algorithm. In terms of localization accuracy, the proposed method outperformed state-of-the-art algorithms in all cases, offering mean absolute localization error as small as 9 cm, at the expense of additional effort for calibration.","PeriodicalId":212607,"journal":{"name":"2021 IEEE International Conference on RFID Technology and Applications (RFID-TA)","volume":"40 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121532018","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 : 2021-10-06DOI: 10.1109/RFID-TA53372.2021.9617308
R. Colella, L. Spedicato, C. Leo, S. Sabina, V. Čongradac, Ognjen Bagatin, L. Catarinucci
In this paper a Battery-Assisted Passive (BAP) RFID based-on sensing system is proposed with the goal of backscattering sensor data to a reader in human monitoring activities. A suitable Printed Circuit Board (PCB) has been designed to integrate the sensors, the tag and the antenna. The sensors consist in two accurate units able to return the body temperature and the systolic pulse signals, from which the heart rate has been estimated. For the sake of transmitting the gathered sensor information, a data packet has been arranged and returned to the interrogating reader. The device size has been minimized by adopting an 866 MHz ceramic antenna. A very appreciable working distance between the tag and the reader has been obtained both in case of device worn or not. In addition to the electromagnetic properties, design aspects of sensors, microcontroller, and RFID chip and have been taken into consideration to realize a comfortable device.
{"title":"Design and Technology Transfer of RFID-Based Medical Sensing Devices","authors":"R. Colella, L. Spedicato, C. Leo, S. Sabina, V. Čongradac, Ognjen Bagatin, L. Catarinucci","doi":"10.1109/RFID-TA53372.2021.9617308","DOIUrl":"https://doi.org/10.1109/RFID-TA53372.2021.9617308","url":null,"abstract":"In this paper a Battery-Assisted Passive (BAP) RFID based-on sensing system is proposed with the goal of backscattering sensor data to a reader in human monitoring activities. A suitable Printed Circuit Board (PCB) has been designed to integrate the sensors, the tag and the antenna. The sensors consist in two accurate units able to return the body temperature and the systolic pulse signals, from which the heart rate has been estimated. For the sake of transmitting the gathered sensor information, a data packet has been arranged and returned to the interrogating reader. The device size has been minimized by adopting an 866 MHz ceramic antenna. A very appreciable working distance between the tag and the reader has been obtained both in case of device worn or not. In addition to the electromagnetic properties, design aspects of sensors, microcontroller, and RFID chip and have been taken into consideration to realize a comfortable device.","PeriodicalId":212607,"journal":{"name":"2021 IEEE International Conference on RFID Technology and Applications (RFID-TA)","volume":"59 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116427675","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 : 2021-10-06DOI: 10.1109/RFID-TA53372.2021.9617413
Vipul Kaushal, A. Birwal, S. M. Patel, Kamlesh Patel
In this paper, two-port circular-ring slot resonator antennas are proposed as RFID tag and reader. The scattering parameters are measured by keeping these antennas in two orientations i.e. same orientation and orthogonal in the complete sub-6 GHz band. Formulas are presented for the forward link and backward link to obtain the path loss. In the forward path, the path loss is found from 24.45 dB to 72.64 dB in frequency range 3.5 to 3.75 GHz while for the backward link, it is 21.70 dB to 66.96 dB range in the same frequency band. Orientation sensitivity confirms the reported antennas can be useful up to 30 cm distance in RFID systems for the 5G frequency band.
{"title":"Path Loss of Two-Port Circular-Ring Slot Antenna For RFID Applications","authors":"Vipul Kaushal, A. Birwal, S. M. Patel, Kamlesh Patel","doi":"10.1109/RFID-TA53372.2021.9617413","DOIUrl":"https://doi.org/10.1109/RFID-TA53372.2021.9617413","url":null,"abstract":"In this paper, two-port circular-ring slot resonator antennas are proposed as RFID tag and reader. The scattering parameters are measured by keeping these antennas in two orientations i.e. same orientation and orthogonal in the complete sub-6 GHz band. Formulas are presented for the forward link and backward link to obtain the path loss. In the forward path, the path loss is found from 24.45 dB to 72.64 dB in frequency range 3.5 to 3.75 GHz while for the backward link, it is 21.70 dB to 66.96 dB range in the same frequency band. Orientation sensitivity confirms the reported antennas can be useful up to 30 cm distance in RFID systems for the 5G frequency band.","PeriodicalId":212607,"journal":{"name":"2021 IEEE International Conference on RFID Technology and Applications (RFID-TA)","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115072797","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 : 2021-10-06DOI: 10.1109/RFID-TA53372.2021.9617361
Mohammad Abdul Shukoor, Shah Sparsh Mukeshbhai, Sukomal Dey
A fully passive 12-Bit multi-resonator based printable chipless RFID system is presented in this work. It focuses on the difficulties of achieving low-cost chip RFID systems. The emergence of chipless RFID systems would be a cheaper solution in the present scenario for low-cost item tracking. The proposed multi-resonator based chipless RFID tag and reader, along with their requirements, and specifications, are specified. By considering the 12-bit encoder, the working and design of the RFID system and its components, such as resonators and antennas, are detailed.
{"title":"12-Bit Multiresonator Based Chipless RFID System for Low-Cost Item Tracking","authors":"Mohammad Abdul Shukoor, Shah Sparsh Mukeshbhai, Sukomal Dey","doi":"10.1109/RFID-TA53372.2021.9617361","DOIUrl":"https://doi.org/10.1109/RFID-TA53372.2021.9617361","url":null,"abstract":"A fully passive 12-Bit multi-resonator based printable chipless RFID system is presented in this work. It focuses on the difficulties of achieving low-cost chip RFID systems. The emergence of chipless RFID systems would be a cheaper solution in the present scenario for low-cost item tracking. The proposed multi-resonator based chipless RFID tag and reader, along with their requirements, and specifications, are specified. By considering the 12-bit encoder, the working and design of the RFID system and its components, such as resonators and antennas, are detailed.","PeriodicalId":212607,"journal":{"name":"2021 IEEE International Conference on RFID Technology and Applications (RFID-TA)","volume":"118 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121253127","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 : 2021-10-06DOI: 10.1109/RFID-TA53372.2021.9617441
Vibhor Binzlekar, Saurabh Singh, S. Agarwal
A miniature Vivaldi antenna with high gain and ultrawideband (UWB) characteristics is presented in this paper by etching grooves coupled with meandered unit cells. Further, slots at the aperture and the Artificial Material Lens (AML) at the CVA's flank are used to boost the gain over the wider frequency band. The designed antenna has almost endfire radiation patterns, a peak realized gain of 10 dBi and an average gain of more than 4.8 dBi over the complete range. This gives a gain improvement of up to 2.5 dB over the conventional Vivaldi antenna in the operating range of 4.7 to 12.3 GHz with return loss $(vert mathrm{S}11vert)$ below -10 dB. The antenna has been designed over a low-price FR4 substrate with a thickness of 0.8 mm (65 mm x 40 mm) which makes it an interesting candidate for different imaging / RFID applications.
{"title":"A High Gain, UWB Vivaldi Antenna Loaded With Unit Cells for Imaging /RFID Applications","authors":"Vibhor Binzlekar, Saurabh Singh, S. Agarwal","doi":"10.1109/RFID-TA53372.2021.9617441","DOIUrl":"https://doi.org/10.1109/RFID-TA53372.2021.9617441","url":null,"abstract":"A miniature Vivaldi antenna with high gain and ultrawideband (UWB) characteristics is presented in this paper by etching grooves coupled with meandered unit cells. Further, slots at the aperture and the Artificial Material Lens (AML) at the CVA's flank are used to boost the gain over the wider frequency band. The designed antenna has almost endfire radiation patterns, a peak realized gain of 10 dBi and an average gain of more than 4.8 dBi over the complete range. This gives a gain improvement of up to 2.5 dB over the conventional Vivaldi antenna in the operating range of 4.7 to 12.3 GHz with return loss $(vert mathrm{S}11vert)$ below -10 dB. The antenna has been designed over a low-price FR4 substrate with a thickness of 0.8 mm (65 mm x 40 mm) which makes it an interesting candidate for different imaging / RFID applications.","PeriodicalId":212607,"journal":{"name":"2021 IEEE International Conference on RFID Technology and Applications (RFID-TA)","volume":"163 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133538489","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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