Pub Date : 2015-12-01DOI: 10.1109/ICSENST.2015.7438419
M. P. Chang, P. Prucnal, Yanhua Deng
We propose and experimentally demonstrate an optical self-interference cancellation system to realize full-duplex spectrum sensing in cognitive radios. The optical system is an analog radio-frequency front-end module, which cancels in-band self-interference, enabling a radio to simultaneously transmit and receive signals. The system achieves 83 dB of narrowband interference cancellation, and 60 dB of cancellation of a 50 MHz frequency-modulated signal. The center frequency of the optical canceler is freely tunable across the radio frequency spectrum, limited only by the bandwidth of the photodetector and the electro-optic modulators to 10 GHz. The system is modulation-format independent and requires only one piece of hardware to operate across a wide radio-frequency bandwidth. By reducing self-interference to acceptably low powers, a cognitive radio can continuously sense its radio-frequency environment to detect the presence of a licensed user or scan for spectrum white spaces even while transmitting simultaneously.
{"title":"Full-duplex spectrum sensing in cognitive radios using optical self-interference cancellation","authors":"M. P. Chang, P. Prucnal, Yanhua Deng","doi":"10.1109/ICSENST.2015.7438419","DOIUrl":"https://doi.org/10.1109/ICSENST.2015.7438419","url":null,"abstract":"We propose and experimentally demonstrate an optical self-interference cancellation system to realize full-duplex spectrum sensing in cognitive radios. The optical system is an analog radio-frequency front-end module, which cancels in-band self-interference, enabling a radio to simultaneously transmit and receive signals. The system achieves 83 dB of narrowband interference cancellation, and 60 dB of cancellation of a 50 MHz frequency-modulated signal. The center frequency of the optical canceler is freely tunable across the radio frequency spectrum, limited only by the bandwidth of the photodetector and the electro-optic modulators to 10 GHz. The system is modulation-format independent and requires only one piece of hardware to operate across a wide radio-frequency bandwidth. By reducing self-interference to acceptably low powers, a cognitive radio can continuously sense its radio-frequency environment to detect the presence of a licensed user or scan for spectrum white spaces even while transmitting simultaneously.","PeriodicalId":375376,"journal":{"name":"2015 9th International Conference on Sensing Technology (ICST)","volume":"103 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133484939","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 : 2015-12-01DOI: 10.1109/ICSENST.2015.7438479
V. Mohammadi, R. Kruijs, P. R. Rao, J. M. Sturm, S. Nihtianov
This paper presents our latest results from the investigation of the surface oxide content in boron capped layers used as the entrance window in ultraviolet silicon (UV-Si) photodetectors. These photodetectors have been studied electrically and optically to define the correlation between oxide content and performance, i.e. the direct relationship between the amount of undesired surface oxide in the active region where the boron layer is deposited, and the detector stability to high UV exposure levels. The boron capping layers were deposited by either chemical or physical vapor based deposition techniques (CVD or PVD). Although these techniques provide photodetectors that are highly sensitive to UV radiation [1], the formation of surface oxide during deposition is a major concern, especially for stability. To analyze the oxide content, an XPS (X-ray photoelectron spectroscopy) analysis was performed on high-temperature (HT-CVD: 700 °C), low-temperature (LT-CVD: 400 °C), and room-temperature (RT-CVD: 25 °C) based pure boron (PureB) photodetectors. An inverse relationship between deposition temperature and oxide content was noticed. While the HT-CVD based photodetectors were found to contain 30% of oxide in its active region, this amount drops to less than 10% for LT-CVD, and to a few percent for RT-PVD based process.
{"title":"Influence of the surface oxide content of a boron capping layer on UV photodetector performance","authors":"V. Mohammadi, R. Kruijs, P. R. Rao, J. M. Sturm, S. Nihtianov","doi":"10.1109/ICSENST.2015.7438479","DOIUrl":"https://doi.org/10.1109/ICSENST.2015.7438479","url":null,"abstract":"This paper presents our latest results from the investigation of the surface oxide content in boron capped layers used as the entrance window in ultraviolet silicon (UV-Si) photodetectors. These photodetectors have been studied electrically and optically to define the correlation between oxide content and performance, i.e. the direct relationship between the amount of undesired surface oxide in the active region where the boron layer is deposited, and the detector stability to high UV exposure levels. The boron capping layers were deposited by either chemical or physical vapor based deposition techniques (CVD or PVD). Although these techniques provide photodetectors that are highly sensitive to UV radiation [1], the formation of surface oxide during deposition is a major concern, especially for stability. To analyze the oxide content, an XPS (X-ray photoelectron spectroscopy) analysis was performed on high-temperature (HT-CVD: 700 °C), low-temperature (LT-CVD: 400 °C), and room-temperature (RT-CVD: 25 °C) based pure boron (PureB) photodetectors. An inverse relationship between deposition temperature and oxide content was noticed. While the HT-CVD based photodetectors were found to contain 30% of oxide in its active region, this amount drops to less than 10% for LT-CVD, and to a few percent for RT-PVD based process.","PeriodicalId":375376,"journal":{"name":"2015 9th International Conference on Sensing Technology (ICST)","volume":"77 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132051423","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 : 2015-12-01DOI: 10.1109/ICSENST.2015.7438417
Qingquan Sun
This paper presents a novel context-aware wireless sensor array system for scene analysis in multiple human monitoring. The goal of the research is to achieve real-time scene recognition and human identification through low-cost, low-data-throughput wireless pyroelectric sensor arrays. In the sensing information space, the scenes can be regarded as the combination of a bunch of basis in subspace. Such bases are extracted by using matrix factorization techniques. Geometry-regularized contextual pattern extraction and region of interest (RoI) identification schemes are developed and utilized. Experiment results demonstrate the capabilities of our context-aware sensing system on scene analysis and system adaption. The proposed context-aware wireless sensor system is not limited to pyroelectric sensors, it can be extended to various sensing modalities.
{"title":"Adaptive context-aware sensor array system for scene analysis in multiple human monitoring","authors":"Qingquan Sun","doi":"10.1109/ICSENST.2015.7438417","DOIUrl":"https://doi.org/10.1109/ICSENST.2015.7438417","url":null,"abstract":"This paper presents a novel context-aware wireless sensor array system for scene analysis in multiple human monitoring. The goal of the research is to achieve real-time scene recognition and human identification through low-cost, low-data-throughput wireless pyroelectric sensor arrays. In the sensing information space, the scenes can be regarded as the combination of a bunch of basis in subspace. Such bases are extracted by using matrix factorization techniques. Geometry-regularized contextual pattern extraction and region of interest (RoI) identification schemes are developed and utilized. Experiment results demonstrate the capabilities of our context-aware sensing system on scene analysis and system adaption. The proposed context-aware wireless sensor system is not limited to pyroelectric sensors, it can be extended to various sensing modalities.","PeriodicalId":375376,"journal":{"name":"2015 9th International Conference on Sensing Technology (ICST)","volume":"100 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132339687","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 : 2015-12-01DOI: 10.1109/ICSENST.2015.7438389
Dongwoo Suh, Lin Chen, W. Lu
Schottky photodiode fabricated with Ge/Si core/shell nanowires grown on Si (111) was quantitatively analyzed in terms of electrical properties as well as microstructure. The present device comprised of single nanowire grown by VLS process is quite sensitive enough to detect less than 1 pA at the mid infrared of 3 μm. The barrier of the present nanowire Schottky photodiode isj 1.5 volts. We scrutinized the electrical characteristics of the nanoscale Schottky junction both at forward and reverse bias ranges with thermionic model.
{"title":"Photoelectric characteristics of Schottky diode based on a Ge/Si core/shell nanowire","authors":"Dongwoo Suh, Lin Chen, W. Lu","doi":"10.1109/ICSENST.2015.7438389","DOIUrl":"https://doi.org/10.1109/ICSENST.2015.7438389","url":null,"abstract":"Schottky photodiode fabricated with Ge/Si core/shell nanowires grown on Si (111) was quantitatively analyzed in terms of electrical properties as well as microstructure. The present device comprised of single nanowire grown by VLS process is quite sensitive enough to detect less than 1 pA at the mid infrared of 3 μm. The barrier of the present nanowire Schottky photodiode isj 1.5 volts. We scrutinized the electrical characteristics of the nanoscale Schottky junction both at forward and reverse bias ranges with thermionic model.","PeriodicalId":375376,"journal":{"name":"2015 9th International Conference on Sensing Technology (ICST)","volume":"65 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133827450","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 : 2015-12-01DOI: 10.1109/ICSENST.2015.7438364
Avijit Mathur, T. Newe
The requirements of a Medical Wireless Sensor Networks (MWSN) may vary compared to other networks. The variations could be at different levels i.e. network level, clustering level or security level. This paper looks at the necessary requirements, with particular focus on clustering and routing. It includes an implementation of a MWSN in Contiki operating system using Tmote Sky and openmote technologies. This implementation incorporates a mechanism for the election of a cluster head, and the case of a modified secure routing algorithm. The results are provided with simulation-based, and real world measurements. The paper presents single and collaborative selective forwarding detection and correction with an accuracy check. Additionally, a solution to the problem of malicious nodes dropping control messages has been provided. The uniqueness of the paper resides in the system's capability in detecting and correcting both single and collaborative selective forwarding attacks with 93% and 86% accuracy respectively.
{"title":"Medical WSN: Defense for selective forwarding attack","authors":"Avijit Mathur, T. Newe","doi":"10.1109/ICSENST.2015.7438364","DOIUrl":"https://doi.org/10.1109/ICSENST.2015.7438364","url":null,"abstract":"The requirements of a Medical Wireless Sensor Networks (MWSN) may vary compared to other networks. The variations could be at different levels i.e. network level, clustering level or security level. This paper looks at the necessary requirements, with particular focus on clustering and routing. It includes an implementation of a MWSN in Contiki operating system using Tmote Sky and openmote technologies. This implementation incorporates a mechanism for the election of a cluster head, and the case of a modified secure routing algorithm. The results are provided with simulation-based, and real world measurements. The paper presents single and collaborative selective forwarding detection and correction with an accuracy check. Additionally, a solution to the problem of malicious nodes dropping control messages has been provided. The uniqueness of the paper resides in the system's capability in detecting and correcting both single and collaborative selective forwarding attacks with 93% and 86% accuracy respectively.","PeriodicalId":375376,"journal":{"name":"2015 9th International Conference on Sensing Technology (ICST)","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127809072","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 : 2015-12-01DOI: 10.1109/ICSENST.2015.7438462
Stephan Mühlbacher-Karrer, H. Zangl
In this paper we present a novel approach for Electrical Capacitance Tomography (ECT) with a variable electrode topology of the sensor front end. The topology of the ECT can be continuously varied while the reconstruction takes place. The unique combination of light weight signal processing chain with a variable dual plate planar sensor front end meets the usability and performance requirements of robotic and mobile applications. The experimental results show the feasibility of this approach achieving reconstruction results with low artefacts even with a low number of electrodes not only in the vicinity of the electrodes but also in the center of the Region of Interest (ROI). Moreover, this sensor topology can be miniaturized which eases the integration, e.g., on a robot's end effector.
{"title":"Electrical Capacitance Tomography with a variable topology","authors":"Stephan Mühlbacher-Karrer, H. Zangl","doi":"10.1109/ICSENST.2015.7438462","DOIUrl":"https://doi.org/10.1109/ICSENST.2015.7438462","url":null,"abstract":"In this paper we present a novel approach for Electrical Capacitance Tomography (ECT) with a variable electrode topology of the sensor front end. The topology of the ECT can be continuously varied while the reconstruction takes place. The unique combination of light weight signal processing chain with a variable dual plate planar sensor front end meets the usability and performance requirements of robotic and mobile applications. The experimental results show the feasibility of this approach achieving reconstruction results with low artefacts even with a low number of electrodes not only in the vicinity of the electrodes but also in the center of the Region of Interest (ROI). Moreover, this sensor topology can be miniaturized which eases the integration, e.g., on a robot's end effector.","PeriodicalId":375376,"journal":{"name":"2015 9th International Conference on Sensing Technology (ICST)","volume":"122 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121469012","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 : 2015-12-01DOI: 10.1109/ICSENST.2015.7438432
Noman Shabbir, R. Nawaz, M. N. Iqbal, Juniad Zafar
This paper focuses on the comparative analysis of routing protocols such as Ad-hoc On-demand Distance Vector Routing System (AODV), Dynamic Source Routing (DSR) and Optimized Link State Routing (OLSR). The analysis is been made against different network parameters like network load, end to end delay and throughput in a small scale Wireless Local Area (WLAN) based Wireless Sensor Network (WSN) scenarios to identify the best performing protocol. Simulation results indicate that OLSR gives minimum network load while AODV gives best throughput and in terms of delay, OLSR is more efficient.
{"title":"Routing protocols for small scale WLAN based Wireless Sensor Networks (WSNs)","authors":"Noman Shabbir, R. Nawaz, M. N. Iqbal, Juniad Zafar","doi":"10.1109/ICSENST.2015.7438432","DOIUrl":"https://doi.org/10.1109/ICSENST.2015.7438432","url":null,"abstract":"This paper focuses on the comparative analysis of routing protocols such as Ad-hoc On-demand Distance Vector Routing System (AODV), Dynamic Source Routing (DSR) and Optimized Link State Routing (OLSR). The analysis is been made against different network parameters like network load, end to end delay and throughput in a small scale Wireless Local Area (WLAN) based Wireless Sensor Network (WSN) scenarios to identify the best performing protocol. Simulation results indicate that OLSR gives minimum network load while AODV gives best throughput and in terms of delay, OLSR is more efficient.","PeriodicalId":375376,"journal":{"name":"2015 9th International Conference on Sensing Technology (ICST)","volume":"43 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128572410","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 : 2015-12-01DOI: 10.1109/ICSENST.2015.7438380
J. Ascorbe, C. Sanz, J. Corres, F. Arregui, I. Matías, S. Mukhopadhyay
In this work we present a high sensitivity optical fiber humidity sensor. The configuration chosen for this purpose is a Fabry-Pérot interferometer. The device has been fabricated by means of sputtering. A semiconductor material was used to build the nano-cavity which produces the interferometry. Then the device was introduced into a climatic chamber in order to change relative humidity. Changes of 88 nm have been obtained for relative humidity varying from 20% to 90%, which implies a sensitivity of 1.27 nm/%RH.
{"title":"High sensitivity extrinsic Fabry-Pèrot interferometer for humidity sensing","authors":"J. Ascorbe, C. Sanz, J. Corres, F. Arregui, I. Matías, S. Mukhopadhyay","doi":"10.1109/ICSENST.2015.7438380","DOIUrl":"https://doi.org/10.1109/ICSENST.2015.7438380","url":null,"abstract":"In this work we present a high sensitivity optical fiber humidity sensor. The configuration chosen for this purpose is a Fabry-Pérot interferometer. The device has been fabricated by means of sputtering. A semiconductor material was used to build the nano-cavity which produces the interferometry. Then the device was introduced into a climatic chamber in order to change relative humidity. Changes of 88 nm have been obtained for relative humidity varying from 20% to 90%, which implies a sensitivity of 1.27 nm/%RH.","PeriodicalId":375376,"journal":{"name":"2015 9th International Conference on Sensing Technology (ICST)","volume":"605 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116377678","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 : 2015-12-01DOI: 10.1109/ICSENST.2015.7438443
Kun-Chan Lan, Wen-Yuah Shih
Diagnosing Parkinson's disease (PD) is often difficult, especially in its early stages. It has been estimated that nearly 40% of people with the disease may not be diagnosed. Traditionally, the diagnosis of Parkinson's disease often requires a doctor to observe the patient over time to recognize signs of rigidity. In this work, we propose a PDR-based method to continuously monitor and record the patient's gait characteristics using a smart-phone. Our tool could be useful in providing an early warning to the PD patient to seek medical assistance and help the doctor diagnose the disease earlier.
{"title":"Early detection of neurological disease using a smartphone: A case study","authors":"Kun-Chan Lan, Wen-Yuah Shih","doi":"10.1109/ICSENST.2015.7438443","DOIUrl":"https://doi.org/10.1109/ICSENST.2015.7438443","url":null,"abstract":"Diagnosing Parkinson's disease (PD) is often difficult, especially in its early stages. It has been estimated that nearly 40% of people with the disease may not be diagnosed. Traditionally, the diagnosis of Parkinson's disease often requires a doctor to observe the patient over time to recognize signs of rigidity. In this work, we propose a PDR-based method to continuously monitor and record the patient's gait characteristics using a smart-phone. Our tool could be useful in providing an early warning to the PD patient to seek medical assistance and help the doctor diagnose the disease earlier.","PeriodicalId":375376,"journal":{"name":"2015 9th International Conference on Sensing Technology (ICST)","volume":"2002 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125752257","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 : 2015-12-01DOI: 10.1109/ICSENST.2015.7438405
M. Zan, A. Bakar, T. Horiguchi
We report in this paper the simultaneous employment of two different coding techniques called Walsh code and Golay code for modulating the pump light of Brillouin optical time domain analysis (BOTDA) fiber optic sensor. In this technique, the elements of Walsh code are nested within each element of Golay code and vice versa. The technique also modulates the pump with the non-return-to-zero (NRZ) and return-to-zero (RZ) formats for the inner and outer codes, respectively. Experimental findings have revealed that the proposed coding technique contributed to higher signal-to-noise improvement ratio (SNIR), compared to that of using only one kind of code; we obtained the maximum optical SNIR of about 6 dB. We have also successfully demonstrated 10 cm of high spatial resolution measurement with the use of 1 ns of coded pulse duration.
{"title":"Improvement of signal-to-noise-ratio by combining Walsh and Golay codes in modulating the pump light of phase-shift pulse BOTDA fiber sensor","authors":"M. Zan, A. Bakar, T. Horiguchi","doi":"10.1109/ICSENST.2015.7438405","DOIUrl":"https://doi.org/10.1109/ICSENST.2015.7438405","url":null,"abstract":"We report in this paper the simultaneous employment of two different coding techniques called Walsh code and Golay code for modulating the pump light of Brillouin optical time domain analysis (BOTDA) fiber optic sensor. In this technique, the elements of Walsh code are nested within each element of Golay code and vice versa. The technique also modulates the pump with the non-return-to-zero (NRZ) and return-to-zero (RZ) formats for the inner and outer codes, respectively. Experimental findings have revealed that the proposed coding technique contributed to higher signal-to-noise improvement ratio (SNIR), compared to that of using only one kind of code; we obtained the maximum optical SNIR of about 6 dB. We have also successfully demonstrated 10 cm of high spatial resolution measurement with the use of 1 ns of coded pulse duration.","PeriodicalId":375376,"journal":{"name":"2015 9th International Conference on Sensing Technology (ICST)","volume":"176 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122787352","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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