Pub Date : 2010-06-21DOI: 10.1109/WIMESH.2010.5507899
T. Kim, J. Ni, N. Vaidya
This paper addresses a distributed throughput- optimal CSMA for wireless networks, which is called the preemptive CSMA. Distinguished from other throughput-optimal CSMAs in the literature, it achieves the optimality even with the throughput loss caused by discrete backoff time, non-zero carrier sense delay and data packet collisions. Moreover, the analysis on the preemptive CSMA provides the understanding on the relationship among the throughput-optimal CSMAs.
{"title":"A Distributed Throughput-Optimal CSMA with Data Packet Collisions","authors":"T. Kim, J. Ni, N. Vaidya","doi":"10.1109/WIMESH.2010.5507899","DOIUrl":"https://doi.org/10.1109/WIMESH.2010.5507899","url":null,"abstract":"This paper addresses a distributed throughput- optimal CSMA for wireless networks, which is called the preemptive CSMA. Distinguished from other throughput-optimal CSMAs in the literature, it achieves the optimality even with the throughput loss caused by discrete backoff time, non-zero carrier sense delay and data packet collisions. Moreover, the analysis on the preemptive CSMA provides the understanding on the relationship among the throughput-optimal CSMAs.","PeriodicalId":368847,"journal":{"name":"2010 Fifth IEEE Workshop on Wireless Mesh Networks","volume":"78 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128398915","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 : 2010-06-21DOI: 10.1109/WIMESH.2010.5507902
Chuan Qin, N. Santhapuri, Souvik Sen, Srihari Nelakuditi
Reception of duplicate packets by a node in a wireless network is a common occurrence. Reasons for repeated transmissions range from broadcast flooding to multicast streaming to unicast forwarding. These repeated transmissions may also get involved in collisions like other original transmissions. We argue that when one of the colliding packets is previously overheard, its interference can be cancelled to decode the other packet. In other words, when a receiver overhears a packet, it becomes effectively immune to the interference caused by the packet's subsequent transmission. We refer to this as known interference cancellation (KIC). In this paper, we identify the scenarios in which KIC is applicable. We then implement KIC on USRP/GnuRadio testbed to demonstrate its feasibility and conduct QualNet simulations to illustrate its potential performance gain.
{"title":"Known Interference Cancellation: Resolving Collisions Due to Repeated Transmissions","authors":"Chuan Qin, N. Santhapuri, Souvik Sen, Srihari Nelakuditi","doi":"10.1109/WIMESH.2010.5507902","DOIUrl":"https://doi.org/10.1109/WIMESH.2010.5507902","url":null,"abstract":"Reception of duplicate packets by a node in a wireless network is a common occurrence. Reasons for repeated transmissions range from broadcast flooding to multicast streaming to unicast forwarding. These repeated transmissions may also get involved in collisions like other original transmissions. We argue that when one of the colliding packets is previously overheard, its interference can be cancelled to decode the other packet. In other words, when a receiver overhears a packet, it becomes effectively immune to the interference caused by the packet's subsequent transmission. We refer to this as known interference cancellation (KIC). In this paper, we identify the scenarios in which KIC is applicable. We then implement KIC on USRP/GnuRadio testbed to demonstrate its feasibility and conduct QualNet simulations to illustrate its potential performance gain.","PeriodicalId":368847,"journal":{"name":"2010 Fifth IEEE Workshop on Wireless Mesh Networks","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124212523","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 : 2010-06-21DOI: 10.1109/WIMESH.2010.5507907
E. Baccelli, Juan Antonio Cordero, P. Jacquet
Achieving reliable communication of critical data on mobile ad hoc networks is a must before MANETs can be considered practical for standard mobile and vehicular communications. This paper thus focuses on schemes that complement existing ad hoc broadcast mechanisms (inherently unreliable), which can guarantee the full diffusion of critical messages, when necessary. An interesting approach in this domain is the use of an overlay network, over which critical messages are acknowledged peer to peer, in order to verify the actual dissemination. This paper elaborates on the problem of performance, related to the discovery and the maintenance of such an overlay network, in a mobile ad hoc context. We present an analysis of a novel algorithm, SLOT (Synchronized Link Overlay - Triangular), an overlay selected based on a Relative Neighborhood Graph (RNG) scheme, and we compare its performance with that of other existing algorithms, in the context of the industry-standard IP routing protocol OSPF, which uses alternative overlay algorithms to synchronize link state databases of routers. The results presented in this paper show that SLOT outperforms other existing overlays by necessitating drastically less control traffic in order to function, enabling OSPF to scale to larger mobile ad hoc topologies.
{"title":"Using Relative Neighborhood Graphs for Reliable Database Synchronization in MANETs","authors":"E. Baccelli, Juan Antonio Cordero, P. Jacquet","doi":"10.1109/WIMESH.2010.5507907","DOIUrl":"https://doi.org/10.1109/WIMESH.2010.5507907","url":null,"abstract":"Achieving reliable communication of critical data on mobile ad hoc networks is a must before MANETs can be considered practical for standard mobile and vehicular communications. This paper thus focuses on schemes that complement existing ad hoc broadcast mechanisms (inherently unreliable), which can guarantee the full diffusion of critical messages, when necessary. An interesting approach in this domain is the use of an overlay network, over which critical messages are acknowledged peer to peer, in order to verify the actual dissemination. This paper elaborates on the problem of performance, related to the discovery and the maintenance of such an overlay network, in a mobile ad hoc context. We present an analysis of a novel algorithm, SLOT (Synchronized Link Overlay - Triangular), an overlay selected based on a Relative Neighborhood Graph (RNG) scheme, and we compare its performance with that of other existing algorithms, in the context of the industry-standard IP routing protocol OSPF, which uses alternative overlay algorithms to synchronize link state databases of routers. The results presented in this paper show that SLOT outperforms other existing overlays by necessitating drastically less control traffic in order to function, enabling OSPF to scale to larger mobile ad hoc topologies.","PeriodicalId":368847,"journal":{"name":"2010 Fifth IEEE Workshop on Wireless Mesh Networks","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114479317","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 : 2010-06-21DOI: 10.1109/WIMESH.2010.5507909
Sookhyun Yang, Sudarshan Vasudevan, J. Kurose
We consider the problem of identifying a node that incorrectly forwards packets in a static wireless ad hoc network. We propose a detection scheme that identifies a misbehaving node based on observations made by neighboring nodes (witnesses) near the forwarding node. Without longterm or cumulative observation, the proposed scheme makes an instantaneous decision about whether a node is correctly forwarding a packet. Through extensive analysis under various threat scenarios, we show that our scheme can unambiguously identify a misbehaving node when there is no collusion. We analyze our scheme's detection accuracy accounting for the lossy nature of wireless links, finding that our scheme can achieve high detection accuracy while incurring low communication overhead.
{"title":"Witness-Based Detection of Forwarding Misbehaviors in Wireless Networks","authors":"Sookhyun Yang, Sudarshan Vasudevan, J. Kurose","doi":"10.1109/WIMESH.2010.5507909","DOIUrl":"https://doi.org/10.1109/WIMESH.2010.5507909","url":null,"abstract":"We consider the problem of identifying a node that incorrectly forwards packets in a static wireless ad hoc network. We propose a detection scheme that identifies a misbehaving node based on observations made by neighboring nodes (witnesses) near the forwarding node. Without longterm or cumulative observation, the proposed scheme makes an instantaneous decision about whether a node is correctly forwarding a packet. Through extensive analysis under various threat scenarios, we show that our scheme can unambiguously identify a misbehaving node when there is no collusion. We analyze our scheme's detection accuracy accounting for the lossy nature of wireless links, finding that our scheme can achieve high detection accuracy while incurring low communication overhead.","PeriodicalId":368847,"journal":{"name":"2010 Fifth IEEE Workshop on Wireless Mesh Networks","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134323438","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 : 2010-06-21DOI: 10.1109/WIMESH.2010.5507900
Gary V. Yee, D. Grunwald, D. Sicker
Mesh networks are always challenged for bandwidth since they use wireless connections for both access links and backhaul. This paper presents a methodology for studying wireless networking optimizations from the perspective of a network administrator: given a set of wireless optimization algorithms, how do we determine the best configuration of these algorithms? We not only attempt to find the best combination of channel assignment, association control, transmit power control, bit-rate adaptation and beam-form selection algorithms, but we are also the first to consider the order in which those distinct algorithms should be applied as a primary property. This paper addresses a centralized, measurement-driven optimization system used in simulation and a field deployment to administer these optimization configurations in an outdoor 802.11b WLAN featuring multiple, beam forming access points. The results should be applicable to either the backhaul, access or combined wireless links in a mesh. Aggregate throughput results are processed by a decision tree to classify optimization configurations into top and bottom tiers using pairwise ordering and algorithm selection attributes. The results demonstrate that: (1) the relative ranking of an algorithm from an optimization domain is dependent upon the combination and ordering in which it is applied and (2) the ordering of a set of algorithms is as significant to final performance as the combination selected.
{"title":"The Effect of Ordering on Wireless Optimization Algorithms","authors":"Gary V. Yee, D. Grunwald, D. Sicker","doi":"10.1109/WIMESH.2010.5507900","DOIUrl":"https://doi.org/10.1109/WIMESH.2010.5507900","url":null,"abstract":"Mesh networks are always challenged for bandwidth since they use wireless connections for both access links and backhaul. This paper presents a methodology for studying wireless networking optimizations from the perspective of a network administrator: given a set of wireless optimization algorithms, how do we determine the best configuration of these algorithms? We not only attempt to find the best combination of channel assignment, association control, transmit power control, bit-rate adaptation and beam-form selection algorithms, but we are also the first to consider the order in which those distinct algorithms should be applied as a primary property. This paper addresses a centralized, measurement-driven optimization system used in simulation and a field deployment to administer these optimization configurations in an outdoor 802.11b WLAN featuring multiple, beam forming access points. The results should be applicable to either the backhaul, access or combined wireless links in a mesh. Aggregate throughput results are processed by a decision tree to classify optimization configurations into top and bottom tiers using pairwise ordering and algorithm selection attributes. The results demonstrate that: (1) the relative ranking of an algorithm from an optimization domain is dependent upon the combination and ordering in which it is applied and (2) the ordering of a set of algorithms is as significant to final performance as the combination selected.","PeriodicalId":368847,"journal":{"name":"2010 Fifth IEEE Workshop on Wireless Mesh Networks","volume":"46 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115772951","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 : 2010-06-21DOI: 10.1109/WIMESH.2010.5507903
Farhana Ashraf, R. Crepaldi, R. Kravets
Synchronization and signaling are two common approaches used for coordination in duty-cycling wireless sensor networks. In this paper we analyze the trade off between these two approaches used for energy-efficient communication. Finally, we present Neighborhood-based Power Management (NPM), a hybrid MAC protocol that minimizes signaling overhead through opportunistically gained knowledge about neighbor wakeup schedules. Unlike the synchronization-based MAC protocols, NPM does not require a priori knowledge of the wakeup schedules. Using only a minimal exchange of schedule information, NPM reduces the signaling overhead by combining adaptive preambling with its neighborhood wakeup mechanism. Our simulations show that NPM outperforms popular B-MAC [1], X-MAC [2] and SCP [3] protocols under all network conditions.
{"title":"Synchronization vs. Signaling: Energy-Efficient Coordination in WSN","authors":"Farhana Ashraf, R. Crepaldi, R. Kravets","doi":"10.1109/WIMESH.2010.5507903","DOIUrl":"https://doi.org/10.1109/WIMESH.2010.5507903","url":null,"abstract":"Synchronization and signaling are two common approaches used for coordination in duty-cycling wireless sensor networks. In this paper we analyze the trade off between these two approaches used for energy-efficient communication. Finally, we present Neighborhood-based Power Management (NPM), a hybrid MAC protocol that minimizes signaling overhead through opportunistically gained knowledge about neighbor wakeup schedules. Unlike the synchronization-based MAC protocols, NPM does not require a priori knowledge of the wakeup schedules. Using only a minimal exchange of schedule information, NPM reduces the signaling overhead by combining adaptive preambling with its neighborhood wakeup mechanism. Our simulations show that NPM outperforms popular B-MAC [1], X-MAC [2] and SCP [3] protocols under all network conditions.","PeriodicalId":368847,"journal":{"name":"2010 Fifth IEEE Workshop on Wireless Mesh Networks","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125263389","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 : 2010-06-21DOI: 10.1109/WIMESH.2010.5507904
M. Di Felice, K. Chowdhury, W. Meleis, L. Bononi
Wireless mesh networks, composed of interconnected clusters of mesh router (MR) and multiple associated mesh clients (MCs), may use cognitive radio equipped transceivers, allowing them to choose licensed frequencies for high bandwidth communication. However, the protection of the licensed users in these bands is a key constraint. In this paper, we propose a reinforcement learning based approach that allows each mesh cluster to independently decide the operative channel, the durations for spectrum sensing, the time of switching, and the duration for which the data transmission happens. The contributions made in this paper are threefold. First, based on accumulated rewards for a channel mapped to the link transmission delays, and the estimated licensed user activity, the MRs assign a weight to each of the channels, thereby selecting the channel with highest performance for MCs operations. Second, our algorithm allows dynamic selection of the sensing time interval that optimizes the link throughput. Third, by cooperative sharing, we allow the MRs to share their channel table information, thus allowing a more accurate learning model. Simulations results reveal significant improvement over classical schemes which have pre-set sensing and transmission durations in the absence of learning.
{"title":"To Sense or to Transmit: A Learning-Based Spectrum Management Scheme for Cognitive Radiomesh Networks","authors":"M. Di Felice, K. Chowdhury, W. Meleis, L. Bononi","doi":"10.1109/WIMESH.2010.5507904","DOIUrl":"https://doi.org/10.1109/WIMESH.2010.5507904","url":null,"abstract":"Wireless mesh networks, composed of interconnected clusters of mesh router (MR) and multiple associated mesh clients (MCs), may use cognitive radio equipped transceivers, allowing them to choose licensed frequencies for high bandwidth communication. However, the protection of the licensed users in these bands is a key constraint. In this paper, we propose a reinforcement learning based approach that allows each mesh cluster to independently decide the operative channel, the durations for spectrum sensing, the time of switching, and the duration for which the data transmission happens. The contributions made in this paper are threefold. First, based on accumulated rewards for a channel mapped to the link transmission delays, and the estimated licensed user activity, the MRs assign a weight to each of the channels, thereby selecting the channel with highest performance for MCs operations. Second, our algorithm allows dynamic selection of the sensing time interval that optimizes the link throughput. Third, by cooperative sharing, we allow the MRs to share their channel table information, thus allowing a more accurate learning model. Simulations results reveal significant improvement over classical schemes which have pre-set sensing and transmission durations in the absence of learning.","PeriodicalId":368847,"journal":{"name":"2010 Fifth IEEE Workshop on Wireless Mesh Networks","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131178441","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 : 2010-06-21DOI: 10.1109/WIMESH.2010.5507901
Thomas Huehn, R. Merz, C. Sengul
A substantial variety of control algorithms to adjust carrier sensing, transmission power, and transmission rate have been proposed for IEEE 802.11 wireless networks in the recent literature. Their objectives range from maximizing throughput, spatial reuse, and fairness to minimizing interference and congestion within the network. However, only a few of these have been implemented and analysed in practice, often because accessing and changing the necessary parameters in the wireless hardware is too difficult. Essentially, there is little understanding about the interactions of jointly adjusted transmission rate, power and carrier sense thresholds, and their impact on the aforementioned objectives. Therefore, in this paper, we focus on transmission rate, power and carrier sensing settings. We provide a detailed description of the common IEEE 802.11 radio hardware, especially in terms of carrier-sensing circuitry. We then present our results from our validation and initial measurement study, which demonstrate interactions between transmit power and rate under different carrier-sensing settings in a two link scenario. Our initial findings indicate there exists a limited number of rate-power combinations that achieve high performance in terms of either throughput and fairness both with and without carrier sensing. Furthermore, in the case of both strong and weak links exist in the network, turning carrier sensing off significantly improves performance.
{"title":"Joint Transmission Rate, Power, and Carrier Sense Settings: An Initial Measurement Study","authors":"Thomas Huehn, R. Merz, C. Sengul","doi":"10.1109/WIMESH.2010.5507901","DOIUrl":"https://doi.org/10.1109/WIMESH.2010.5507901","url":null,"abstract":"A substantial variety of control algorithms to adjust carrier sensing, transmission power, and transmission rate have been proposed for IEEE 802.11 wireless networks in the recent literature. Their objectives range from maximizing throughput, spatial reuse, and fairness to minimizing interference and congestion within the network. However, only a few of these have been implemented and analysed in practice, often because accessing and changing the necessary parameters in the wireless hardware is too difficult. Essentially, there is little understanding about the interactions of jointly adjusted transmission rate, power and carrier sense thresholds, and their impact on the aforementioned objectives. Therefore, in this paper, we focus on transmission rate, power and carrier sensing settings. We provide a detailed description of the common IEEE 802.11 radio hardware, especially in terms of carrier-sensing circuitry. We then present our results from our validation and initial measurement study, which demonstrate interactions between transmit power and rate under different carrier-sensing settings in a two link scenario. Our initial findings indicate there exists a limited number of rate-power combinations that achieve high performance in terms of either throughput and fairness both with and without carrier sensing. Furthermore, in the case of both strong and weak links exist in the network, turning carrier sensing off significantly improves performance.","PeriodicalId":368847,"journal":{"name":"2010 Fifth IEEE Workshop on Wireless Mesh Networks","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124638335","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 : 2010-06-21DOI: 10.1109/WIMESH.2010.5507905
B. Radunovic, Dinan Gunawardena, P. Key, A. Proutière, Nikhil Singh, Vlad Balan, G. DeJean
Existing indoor WiFi networks in the 2.5GHz and 5 GHz use too much transmit power, needed because the high carrier frequency limits signal penetration and connectivity. Instead, we propose a novel indoor wireless mesh design paradigm, based on Low Frequency, using the newly freed white spaces previously used as analogue TV bands, and Low Power - 100 times less power than currently used. Preliminary experiments show that this maintains a similar level of connectivity and performance to existing networks. It also yields more uniform connectivity, thus simplifies MAC and routing protocol design. We also advocate full-duplex networking in a single band, which becomes possible in this setting (because we operate at low frequencies). It potentially doubles the throughput of each link and eliminates hidden terminals.
{"title":"Rethinking Indoor Wireless Mesh Design: Low Power, Low Frequency, Full-Duplex","authors":"B. Radunovic, Dinan Gunawardena, P. Key, A. Proutière, Nikhil Singh, Vlad Balan, G. DeJean","doi":"10.1109/WIMESH.2010.5507905","DOIUrl":"https://doi.org/10.1109/WIMESH.2010.5507905","url":null,"abstract":"Existing indoor WiFi networks in the 2.5GHz and 5 GHz use too much transmit power, needed because the high carrier frequency limits signal penetration and connectivity. Instead, we propose a novel indoor wireless mesh design paradigm, based on Low Frequency, using the newly freed white spaces previously used as analogue TV bands, and Low Power - 100 times less power than currently used. Preliminary experiments show that this maintains a similar level of connectivity and performance to existing networks. It also yields more uniform connectivity, thus simplifies MAC and routing protocol design. We also advocate full-duplex networking in a single band, which becomes possible in this setting (because we operate at low frequencies). It potentially doubles the throughput of each link and eliminates hidden terminals.","PeriodicalId":368847,"journal":{"name":"2010 Fifth IEEE Workshop on Wireless Mesh Networks","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128809813","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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