In this work, a magneto inductive (MI) link design is studied to achieve high speed transmission applied to a high density underwater network. For a small loop antenna, a design procedure is described to define the optimal operating frequency constrained on the system bandwidth and range. A coherent link is established between two nodes in a controlled underwater environment. For a small coil with radius of 5 cm, simulation results indicate that a range above 10 meters can be achieved in the low frequency spectrum spanning 10 kHz to 1 MHz. The design procedure is validated through measurements in seawater: a very high output SNR equal to 31.4 dB is realized at the output of the equalizer, and in these conditions a perfectly reliable 8-kbps link is demonstrated at a center frequency of 22.5 kHz.
{"title":"A compact low-power underwater magneto-inductive modem","authors":"Yibin Wang, Andrew Dobbin, Jean-François Bousquet","doi":"10.1145/2999504.3001064","DOIUrl":"https://doi.org/10.1145/2999504.3001064","url":null,"abstract":"In this work, a magneto inductive (MI) link design is studied to achieve high speed transmission applied to a high density underwater network. For a small loop antenna, a design procedure is described to define the optimal operating frequency constrained on the system bandwidth and range. A coherent link is established between two nodes in a controlled underwater environment. For a small coil with radius of 5 cm, simulation results indicate that a range above 10 meters can be achieved in the low frequency spectrum spanning 10 kHz to 1 MHz. The design procedure is validated through measurements in seawater: a very high output SNR equal to 31.4 dB is realized at the output of the equalizer, and in these conditions a perfectly reliable 8-kbps link is demonstrated at a center frequency of 22.5 kHz.","PeriodicalId":378624,"journal":{"name":"Proceedings of the 11th International Conference on Underwater Networks & Systems","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123112967","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}
As a critical technique to support the multimedia services, the statistical quality-of-service (QoS) technique has been proved to be effective in statistically guaranteeing delay-bounded video transmissions over the time-varying wireless channels. On the other hand, since both the natural acoustic systems and artificial acoustic systems use the acoustic channels, the spectrum resource is severely limited in underwater wireless networks. Researchers have proposed the underwater cognitive acoustic network (UCAN) to achieve the environment-friendly and spectrum-efficient transmissions over acoustic channels. However, how to efficiently integrate the UCAN under the statistical QoS constraints is still an open problem. To overcome this difficulty, we propose the QoS-driven power allocation scheme over UCAN. In particular, we propose and analyze the underwater cognitive system models and develop the optimal power allocation scheme in cognitive acoustic scenario udder statistical QoS requirements. Also conducted is a set of simulations which evaluate the system performance over UCAN.
{"title":"Statistical QoS-driven power allocation over underwater cognitive acoustic networks","authors":"Jingqing Wang, Xi Zhang","doi":"10.1145/2999504.3001114","DOIUrl":"https://doi.org/10.1145/2999504.3001114","url":null,"abstract":"As a critical technique to support the multimedia services, the statistical quality-of-service (QoS) technique has been proved to be effective in statistically guaranteeing delay-bounded video transmissions over the time-varying wireless channels. On the other hand, since both the natural acoustic systems and artificial acoustic systems use the acoustic channels, the spectrum resource is severely limited in underwater wireless networks. Researchers have proposed the underwater cognitive acoustic network (UCAN) to achieve the environment-friendly and spectrum-efficient transmissions over acoustic channels. However, how to efficiently integrate the UCAN under the statistical QoS constraints is still an open problem. To overcome this difficulty, we propose the QoS-driven power allocation scheme over UCAN. In particular, we propose and analyze the underwater cognitive system models and develop the optimal power allocation scheme in cognitive acoustic scenario udder statistical QoS requirements. Also conducted is a set of simulations which evaluate the system performance over UCAN.","PeriodicalId":378624,"journal":{"name":"Proceedings of the 11th International Conference on Underwater Networks & Systems","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125079592","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}
Guannan Li, Jun Liu, Xue Wang, Hongli Xu, Jun-hong Cui
This paper presents a simulator for swarm operations designed to verify algorithms for a swarm of autonomous underwater robots (AUVs), specifically for constructing an underwater communication network with AUVs carrying acoustic communication devices. This simulator consists of three nodes: a virtual vehicle node (VV), a virtual environment node (VE), and a visual showing node (VS). The modular design treats AUV models as a combination of virtual equipment. An expert acoustic communication simulator is embedded in this simulator, to simulate scenarios with dynamic acoustic communication nodes. The several simulations we have performed demonstrate that this simulator is easy to use and can be further improved.
{"title":"A simulator for swarm AUVs acoustic communication networking","authors":"Guannan Li, Jun Liu, Xue Wang, Hongli Xu, Jun-hong Cui","doi":"10.1145/2999504.3001075","DOIUrl":"https://doi.org/10.1145/2999504.3001075","url":null,"abstract":"This paper presents a simulator for swarm operations designed to verify algorithms for a swarm of autonomous underwater robots (AUVs), specifically for constructing an underwater communication network with AUVs carrying acoustic communication devices. This simulator consists of three nodes: a virtual vehicle node (VV), a virtual environment node (VE), and a visual showing node (VS). The modular design treats AUV models as a combination of virtual equipment. An expert acoustic communication simulator is embedded in this simulator, to simulate scenarios with dynamic acoustic communication nodes. The several simulations we have performed demonstrate that this simulator is easy to use and can be further improved.","PeriodicalId":378624,"journal":{"name":"Proceedings of the 11th International Conference on Underwater Networks & Systems","volume":"28 9","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"113939345","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}
Direct sequence spread spectrum (DSSS) provides a robust solution for shallow water acoustic communications. DSSS uses a code sequence to spread the symbols at the transmitter; the coded sequence is then modulated using phase-shift-keying (DS/PSK) or differential phase-shift-keying (DS/DPSK),[1][2] where the information data is carried by the phase of the transmitted symbols or by the relative phase of two adjacent symbols, respectively. The DS/PSK system uses coherent receivers, while the DS/DPSK system uses differential receivers. Differential receivers have lower computation complexity and are insensitive to dynamic-channel-induced phase fluctuation and thus are well suited for applications where autonomy, adaptability, and longlife battery operation are desirable.
{"title":"A novel M-ary differential underwater acoustic direct sequence spread spectrum communication system","authors":"Gangqiang Zhang, Xudong He, Junkai Liu","doi":"10.1145/2999504.3001074","DOIUrl":"https://doi.org/10.1145/2999504.3001074","url":null,"abstract":"Direct sequence spread spectrum (DSSS) provides a robust solution for shallow water acoustic communications. DSSS uses a code sequence to spread the symbols at the transmitter; the coded sequence is then modulated using phase-shift-keying (DS/PSK) or differential phase-shift-keying (DS/DPSK),[1][2] where the information data is carried by the phase of the transmitted symbols or by the relative phase of two adjacent symbols, respectively. The DS/PSK system uses coherent receivers, while the DS/DPSK system uses differential receivers. Differential receivers have lower computation complexity and are insensitive to dynamic-channel-induced phase fluctuation and thus are well suited for applications where autonomy, adaptability, and longlife battery operation are desirable.","PeriodicalId":378624,"journal":{"name":"Proceedings of the 11th International Conference on Underwater Networks & Systems","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133137606","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}
The ability to obtain reliable, long-term visual data in marine habitats has the potential to transform biological surveys of marine species. However, the underwater environment poses several challenges to visual monitoring: turbidity and light attenuation impede the range of optical sensors, biofouling clouds lenses and underwater housings, and marine species typically range over a large area, far outside of the range of a single camera sensor. Due to these factors, a continuously-recording or time-lapse visual sensor will not be gathering useful data the majority of the time, wasting battery life and filling limited onboard storage with useless images. These limitations make visual monitoring difficult in marine environments, but visual data is invaluable to biologists studying the behaviors and interactions of a species. This paper describes an acoustic-based, autonomous triggering approach to counter the current limitations of underwater visual sensing, and motivates the need for a distributed sensor network for underwater visual monitoring.
{"title":"Autonomous acoustic trigger for distributed underwater visual monitoring systems","authors":"A. Wilby, E. Slattery, Andrew Hostler, R. Kastner","doi":"10.1145/2999504.3001080","DOIUrl":"https://doi.org/10.1145/2999504.3001080","url":null,"abstract":"The ability to obtain reliable, long-term visual data in marine habitats has the potential to transform biological surveys of marine species. However, the underwater environment poses several challenges to visual monitoring: turbidity and light attenuation impede the range of optical sensors, biofouling clouds lenses and underwater housings, and marine species typically range over a large area, far outside of the range of a single camera sensor. Due to these factors, a continuously-recording or time-lapse visual sensor will not be gathering useful data the majority of the time, wasting battery life and filling limited onboard storage with useless images. These limitations make visual monitoring difficult in marine environments, but visual data is invaluable to biologists studying the behaviors and interactions of a species. This paper describes an acoustic-based, autonomous triggering approach to counter the current limitations of underwater visual sensing, and motivates the need for a distributed sensor network for underwater visual monitoring.","PeriodicalId":378624,"journal":{"name":"Proceedings of the 11th International Conference on Underwater Networks & Systems","volume":"55 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133353413","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}
Most underwater acoustic communication systems incorporate well-recognized, easily detectable narrowband signals modulated over low-frequency carriers at high transmission powers, which ultimately limits LPD/LPI performance of the communication scheme. While there have been promising works concentrating on LPD/LPI performance, they are for the most part based on direct-sequence spread spectrum (DSSS) techniques, which have been shown to be blindly detectable in previous work at relatively low SINR values. As a result, there is likely significant room to improve the LPD/LPI performance of underwater acoustic communication schemes. To this end, in this paper, we propose the preliminary design of a novel communication scheme based on transmitting chirp signals that are further spread over a multidimensional domain spanning code, time, and frequency. We evaluated the performance of the proposed scheme both with simulation and experimental studies.
{"title":"Chirp-based LPD/LPI underwater acoustic communications with code-time-frequency multidimensional spreading","authors":"Emrecan Demirors, T. Melodia","doi":"10.1145/2999504.3001083","DOIUrl":"https://doi.org/10.1145/2999504.3001083","url":null,"abstract":"Most underwater acoustic communication systems incorporate well-recognized, easily detectable narrowband signals modulated over low-frequency carriers at high transmission powers, which ultimately limits LPD/LPI performance of the communication scheme. While there have been promising works concentrating on LPD/LPI performance, they are for the most part based on direct-sequence spread spectrum (DSSS) techniques, which have been shown to be blindly detectable in previous work at relatively low SINR values. As a result, there is likely significant room to improve the LPD/LPI performance of underwater acoustic communication schemes. To this end, in this paper, we propose the preliminary design of a novel communication scheme based on transmitting chirp signals that are further spread over a multidimensional domain spanning code, time, and frequency. We evaluated the performance of the proposed scheme both with simulation and experimental studies.","PeriodicalId":378624,"journal":{"name":"Proceedings of the 11th International Conference on Underwater Networks & Systems","volume":"71 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131877871","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}
Distributed detection with data fusion has gained great attention in recent years. Collaborative detection improves the performance, and the optimal sensor deployment may change with time. It has been shown that with data fusion less sensors are needed to get the same detection ability when abundant sensors are deployed randomly. However, because of limitations on equipment number and deployment methods, fixed sensor locations may be preferred underwater. In this paper, we try to establish a theoretical framework for finding sensor positions to maximize the detection probability with a distributed sensor network. With joint data processing, detection performance is related to all the sensor locations; as sensor number grows, the optimization problem would become more difficult. To simplify the demonstration, we choose a 1-dimensional line deployment model and present the relevant numerical results.
{"title":"Distributed sensor layout optimization for target detection with data fusion","authors":"Zhongyue Chen, Wenham Xu, Hui-fang Chen","doi":"10.1145/2999504.3001087","DOIUrl":"https://doi.org/10.1145/2999504.3001087","url":null,"abstract":"Distributed detection with data fusion has gained great attention in recent years. Collaborative detection improves the performance, and the optimal sensor deployment may change with time. It has been shown that with data fusion less sensors are needed to get the same detection ability when abundant sensors are deployed randomly. However, because of limitations on equipment number and deployment methods, fixed sensor locations may be preferred underwater. In this paper, we try to establish a theoretical framework for finding sensor positions to maximize the detection probability with a distributed sensor network. With joint data processing, detection performance is related to all the sensor locations; as sensor number grows, the optimization problem would become more difficult. To simplify the demonstration, we choose a 1-dimensional line deployment model and present the relevant numerical results.","PeriodicalId":378624,"journal":{"name":"Proceedings of the 11th International Conference on Underwater Networks & Systems","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132690917","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}
Underwater Acoustic Sensor Networks (UWASNs) have the wide of applications with the proliferation of the increasing underwater activities recently. Most of current studies are focused on designing protocols to improve the network performance of WASNs. However, the security of UWASNs is also an important concern since malicious nodes can easily wiretap the information transmitted in UWASNs due to the vulnerability of UWASNs. In this paper, we investigate one of security problems in UWASNs - eavesdropping behaviours. In particular, we propose a general model to quantitatively evaluate the probability of eavesdropping behaviour in UWASNs. Simulation results also validate the accuracy of our proposed model.
{"title":"On analyzing eavesdropping behaviours in underwater acoustic sensor networks","authors":"Hongning Dai, Hao Wang, Hong Xiao, Zibin Zheng, Qiu Wang, Xuran Li, Xu Zhuge","doi":"10.1145/2999504.3001100","DOIUrl":"https://doi.org/10.1145/2999504.3001100","url":null,"abstract":"Underwater Acoustic Sensor Networks (UWASNs) have the wide of applications with the proliferation of the increasing underwater activities recently. Most of current studies are focused on designing protocols to improve the network performance of WASNs. However, the security of UWASNs is also an important concern since malicious nodes can easily wiretap the information transmitted in UWASNs due to the vulnerability of UWASNs. In this paper, we investigate one of security problems in UWASNs - eavesdropping behaviours. In particular, we propose a general model to quantitatively evaluate the probability of eavesdropping behaviour in UWASNs. Simulation results also validate the accuracy of our proposed model.","PeriodicalId":378624,"journal":{"name":"Proceedings of the 11th International Conference on Underwater Networks & Systems","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128978157","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}
Orthogonal frequency-division multiplexing (OFDM) technique has become a popular choice for underwater acoustic (UA) networks recently. Impulsive noise is one of the factors that limit the performance of this technique, and the mitigation of impulsive noise receives increasing attention in the UA communication community. In this paper, a pilot-based algorithm is proposed to mitigate the impact of impulsive noise. The proposed algorithm introduces a special OFDM block as preamble during which impulsive noise mitigation is performed using the null subcarriers and then the channel response is estimated using pilot subcarriers. By assuming that the channel is quasi-stationary, the proposed algorithm adopts the channel estimation result of the previous block to estimate and mitigate the impulsive noise of the current block. We apply the proposed algorithm to process the data collected during the experiment conducted in December 2015, in the estuary of the Swan River, Western Australia. The results show that the proposed approach is able to mitigate the impulsive noise for UA OFDM systems.
{"title":"Pilot-subcarrier based impulsive noise mitigation for underwater acoustic OFDM systems","authors":"Peng Chen, Y. Rong, S. Nordholm","doi":"10.1145/2999504.3001106","DOIUrl":"https://doi.org/10.1145/2999504.3001106","url":null,"abstract":"Orthogonal frequency-division multiplexing (OFDM) technique has become a popular choice for underwater acoustic (UA) networks recently. Impulsive noise is one of the factors that limit the performance of this technique, and the mitigation of impulsive noise receives increasing attention in the UA communication community. In this paper, a pilot-based algorithm is proposed to mitigate the impact of impulsive noise. The proposed algorithm introduces a special OFDM block as preamble during which impulsive noise mitigation is performed using the null subcarriers and then the channel response is estimated using pilot subcarriers. By assuming that the channel is quasi-stationary, the proposed algorithm adopts the channel estimation result of the previous block to estimate and mitigate the impulsive noise of the current block. We apply the proposed algorithm to process the data collected during the experiment conducted in December 2015, in the estuary of the Swan River, Western Australia. The results show that the proposed approach is able to mitigate the impulsive noise for UA OFDM systems.","PeriodicalId":378624,"journal":{"name":"Proceedings of the 11th International Conference on Underwater Networks & Systems","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116858352","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}
Yanxin Xie, Jun Liu, Cheng-quan Hu, Jun-hong Cui, Hongli Xu
the accuracy of the Autonomous Underwater Vehicles (AUVs) navigation system determines whether they can safely operate and return. Traditional Dead-reckoning (DR) relies on the inertial sensors such as gyroscope and accelerometer. A major challenge for DR navigation is from measurement error of the inertial sensors (gyroscope, accelerometer, etc.), especially when the AUV is near or at the ocean surface. The AUV's motion is affected by ocean waves, and its pitch angle changes rapidly with the waves. This rapid change and the measurement errors will cause great noise to the direction measured by gyroscopes, and then lead to a large error to the DR navigation. To address this problem, a novel DR method based on neural network (DR-N) is proposed to explore the time-varying relationship between acceleration measurement and orientation measurement, which leverages acoustic localization and neural network estimate timely pitch angle through the explored time-varying relationship. This method enables AUV's DR navigation with a single acceleration, without relying on both acceleration and gyroscope. Most importantly, we can improve the accuracy of AUV navigation through avoiding DR errors caused by gyroscope noise at the sea surface. Simulations show DR-N significantly improves navigation accuracy.
{"title":"AUV dead-reckoning navigation based on neural network using a single accelerometer","authors":"Yanxin Xie, Jun Liu, Cheng-quan Hu, Jun-hong Cui, Hongli Xu","doi":"10.1145/2999504.3001081","DOIUrl":"https://doi.org/10.1145/2999504.3001081","url":null,"abstract":"the accuracy of the Autonomous Underwater Vehicles (AUVs) navigation system determines whether they can safely operate and return. Traditional Dead-reckoning (DR) relies on the inertial sensors such as gyroscope and accelerometer. A major challenge for DR navigation is from measurement error of the inertial sensors (gyroscope, accelerometer, etc.), especially when the AUV is near or at the ocean surface. The AUV's motion is affected by ocean waves, and its pitch angle changes rapidly with the waves. This rapid change and the measurement errors will cause great noise to the direction measured by gyroscopes, and then lead to a large error to the DR navigation. To address this problem, a novel DR method based on neural network (DR-N) is proposed to explore the time-varying relationship between acceleration measurement and orientation measurement, which leverages acoustic localization and neural network estimate timely pitch angle through the explored time-varying relationship. This method enables AUV's DR navigation with a single acceleration, without relying on both acceleration and gyroscope. Most importantly, we can improve the accuracy of AUV navigation through avoiding DR errors caused by gyroscope noise at the sea surface. Simulations show DR-N significantly improves navigation accuracy.","PeriodicalId":378624,"journal":{"name":"Proceedings of the 11th International Conference on Underwater Networks & Systems","volume":"93 3","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114111489","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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