M. Doering, Tobias Pögel, Wolf-Bastian Pöttner, L. Wolf
Realistic scenarios are essential for the simulation-based evaluation of opportunistic routing protocols in vehicular networks. Synthetically generated scenarios are easy to obtain but fail to reproduce the complexity of the real world. Therefore, the generally accepted procedure is to use traces recorded in experiments. Unfortunately, this is almost impractical for large-scale scenarios. The advancing pervasion of ICT in transportation systems results in new opportunities for the research community to collect mobility traces from real systems. Using the example of one of the world's largest public transportation network, we demonstrate our approach to acquire realistic traces which are more extensive than existing traces. Moreover, we demonstrate how this data can easily be integrated into the established delay tolerant network (DTN) simulation tool 'The ONE'.
{"title":"A new mobility trace for realistic large-scale simulation of bus-based DTNs","authors":"M. Doering, Tobias Pögel, Wolf-Bastian Pöttner, L. Wolf","doi":"10.1145/1859934.1859950","DOIUrl":"https://doi.org/10.1145/1859934.1859950","url":null,"abstract":"Realistic scenarios are essential for the simulation-based evaluation of opportunistic routing protocols in vehicular networks. Synthetically generated scenarios are easy to obtain but fail to reproduce the complexity of the real world. Therefore, the generally accepted procedure is to use traces recorded in experiments. Unfortunately, this is almost impractical for large-scale scenarios. The advancing pervasion of ICT in transportation systems results in new opportunities for the research community to collect mobility traces from real systems. Using the example of one of the world's largest public transportation network, we demonstrate our approach to acquire realistic traces which are more extensive than existing traces. Moreover, we demonstrate how this data can easily be integrated into the established delay tolerant network (DTN) simulation tool 'The ONE'.","PeriodicalId":404958,"journal":{"name":"CHANTS '10","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123604884","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}
Many DTN environments, such as emergency response networks and pocket-switched networks, are based on human mobility and communication patterns, which naturally lead to groups. In these scenarios, group-based communication is central, and hence a natural and useful routing paradigm is anycast, where a node attempts to communicate with at least one member of a particular group. Unfortunately, most existing anycast solutions assume connectivity, and the few specifically for DTNs are single-copy in nature and have only been evaluated in highly limited mobility models. In this paper, we propose a protocol-independent method of enhancing a large number of existing DTN unicast protocols, giving them the ability to perform anycast communication. This method requires no change to the unicast protocols themselves and instead changes their world view by adding a thin layer beneath the routing layer. Through a thorough set of simulations, we also evaluate how different parameters and network conditions affect the performance of these newly transformed anycast protocols.
{"title":"Achieving anycast in DTNs by enhancing existing unicast protocols","authors":"S. Nelson, R. Kravets","doi":"10.1145/1859934.1859948","DOIUrl":"https://doi.org/10.1145/1859934.1859948","url":null,"abstract":"Many DTN environments, such as emergency response networks and pocket-switched networks, are based on human mobility and communication patterns, which naturally lead to groups. In these scenarios, group-based communication is central, and hence a natural and useful routing paradigm is anycast, where a node attempts to communicate with at least one member of a particular group. Unfortunately, most existing anycast solutions assume connectivity, and the few specifically for DTNs are single-copy in nature and have only been evaluated in highly limited mobility models. In this paper, we propose a protocol-independent method of enhancing a large number of existing DTN unicast protocols, giving them the ability to perform anycast communication. This method requires no change to the unicast protocols themselves and instead changes their world view by adding a thin layer beneath the routing layer. Through a thorough set of simulations, we also evaluate how different parameters and network conditions affect the performance of these newly transformed anycast protocols.","PeriodicalId":404958,"journal":{"name":"CHANTS '10","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114560821","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}
Embedded sensors in mobile devices such as cars and smart phones present new opportunities to collect location-specific data about an environment. This data can be used to enable new real-time location-based applications. A major challenge is efficiently collecting, storing and sharing the data. This paper proposes Locus, a location-based data overlay for DTNs. Locus keeps objects at specific physical locations in the network using whatever devices currently are nearby. Nodes copy objects between themselves to maintain the locality of data. Location utility functions prioritize objects for replication and enable location-based forwarding of data look-ups. As a first-of-its-kind application, Locus is compared against other possible replication policies and shown to achieve query success rates nearly 4 times higher than other approaches.
{"title":"Locus: a location-based data overlay for disruption-tolerant networks","authors":"N. Thompson, R. Crepaldi, R. Kravets","doi":"10.1145/1859934.1859945","DOIUrl":"https://doi.org/10.1145/1859934.1859945","url":null,"abstract":"Embedded sensors in mobile devices such as cars and smart phones present new opportunities to collect location-specific data about an environment. This data can be used to enable new real-time location-based applications. A major challenge is efficiently collecting, storing and sharing the data. This paper proposes Locus, a location-based data overlay for DTNs. Locus keeps objects at specific physical locations in the network using whatever devices currently are nearby. Nodes copy objects between themselves to maintain the locality of data. Location utility functions prioritize objects for replication and enable location-based forwarding of data look-ups. As a first-of-its-kind application, Locus is compared against other possible replication policies and shown to achieve query success rates nearly 4 times higher than other approaches.","PeriodicalId":404958,"journal":{"name":"CHANTS '10","volume":"70 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123462882","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}
Secure, low-overhead key establishment is crucial to maintaining the high level of trust and security that are required many types of Delay Tolerant Networks. Existing schemes for key negotiation and exchange that are currently in use on the Internet often cannot scale to meet the environmental and technical constraints of many Delay Tolerant Networks. The few works presenting solutions to DTN key establishment have largely focused on targeted networking environments. This paper proposes a dynamic, and non-interactive scheme to facilitate secure communication in infrastructureless networks, supporting various levels of trust. Specifically, the solution presented in this paper provides a key management solution to opportunistic overlay networks using the Bundle Protocol.
{"title":"Dynamic, non-interactive key management for the bundle protocol","authors":"W. V. Besien","doi":"10.1145/1859934.1859951","DOIUrl":"https://doi.org/10.1145/1859934.1859951","url":null,"abstract":"Secure, low-overhead key establishment is crucial to maintaining the high level of trust and security that are required many types of Delay Tolerant Networks. Existing schemes for key negotiation and exchange that are currently in use on the Internet often cannot scale to meet the environmental and technical constraints of many Delay Tolerant Networks. The few works presenting solutions to DTN key establishment have largely focused on targeted networking environments. This paper proposes a dynamic, and non-interactive scheme to facilitate secure communication in infrastructureless networks, supporting various levels of trust. Specifically, the solution presented in this paper provides a key management solution to opportunistic overlay networks using the Bundle Protocol.","PeriodicalId":404958,"journal":{"name":"CHANTS '10","volume":"48 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115662669","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}
Communication is crucial to the coordination and efficient operation of public transport systems. However, deployment of infrastructure based communication systems is very expensive. Delay tolerant vehicular networks are a promising alternative since only very few infrastructure elements are required. This paper presents a DTN routing algorithm for urban public transport systems. Beginning with an analysis of node mobility, system characteristics are derived and exploited to improve routing performance. To increase realism in the performance evaluation and comparison a new approach is taken for the generation of mobility traces. A map based on real cartographic data is combined with line definitions, stops and timetables of real public transport systems. A micromobility simulator then produces large scale mobility traces which are fed into a DTN simulator. We compare various DTN routing schemes with our algorithm. Moreover, the impact of disturbances in the public transport system on the routing performance is examined. The results show that our routing algorithm can outperform previously proposed algorithms even if 20% of all vehicles are behind schedule.
{"title":"DTN routing in urban public transport systems","authors":"M. Doering, Tobias Pögel, L. Wolf","doi":"10.1145/1859934.1859947","DOIUrl":"https://doi.org/10.1145/1859934.1859947","url":null,"abstract":"Communication is crucial to the coordination and efficient operation of public transport systems. However, deployment of infrastructure based communication systems is very expensive. Delay tolerant vehicular networks are a promising alternative since only very few infrastructure elements are required. This paper presents a DTN routing algorithm for urban public transport systems. Beginning with an analysis of node mobility, system characteristics are derived and exploited to improve routing performance. To increase realism in the performance evaluation and comparison a new approach is taken for the generation of mobility traces. A map based on real cartographic data is combined with line definitions, stops and timetables of real public transport systems. A micromobility simulator then produces large scale mobility traces which are fed into a DTN simulator. We compare various DTN routing schemes with our algorithm. Moreover, the impact of disturbances in the public transport system on the routing performance is examined. The results show that our routing algorithm can outperform previously proposed algorithms even if 20% of all vehicles are behind schedule.","PeriodicalId":404958,"journal":{"name":"CHANTS '10","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121897343","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}
Modern mobile phones have become tools for the creation and consumption of digital media. There exist cases where the people producing such media content, and those interested in receiving it, tend to be living in the same geographical area. Delay Tolerant Networking (DTN) protocols have started to be investigated as an effective means to distribute content in these dynamically changing settings. The main challenge addressed by researchers so far has been the maximisation of delivery probability, while also minimising the overall network overhead (e.g., number of replicas in the system, messages' path length). Another important challenge that has received little attention so far is how to understand what content users are interested in receiving. The assumption often made is that users have a well defined and up-to-date profile describing their interests, and that content has been classified by means of a shared taxonomy. However, experience with the Web 2.0 demonstrates that, in most cases, neither assumptions hold. We thus propose a light-weight mechanism that dynamically learns what users are interested in based on the tags they use when they create and/or consume content. To maximise the chances of bringing relevant content to interested users, we apply a tag-expansion technique to enrich content descriptions beyond the folksonomy used by a single user to those spoken by the local community. We integrate this approach within a source-based DTN protocol we have previously developed, and evaluate its performance via simulation using real datasets.
{"title":"Folksonomy-based reasoning for content dissemination in mobile settings","authors":"Giacomo Lo Giusto, A. Mashhadi, L. Capra","doi":"10.1145/1859934.1859944","DOIUrl":"https://doi.org/10.1145/1859934.1859944","url":null,"abstract":"Modern mobile phones have become tools for the creation and consumption of digital media. There exist cases where the people producing such media content, and those interested in receiving it, tend to be living in the same geographical area. Delay Tolerant Networking (DTN) protocols have started to be investigated as an effective means to distribute content in these dynamically changing settings. The main challenge addressed by researchers so far has been the maximisation of delivery probability, while also minimising the overall network overhead (e.g., number of replicas in the system, messages' path length). Another important challenge that has received little attention so far is how to understand what content users are interested in receiving. The assumption often made is that users have a well defined and up-to-date profile describing their interests, and that content has been classified by means of a shared taxonomy. However, experience with the Web 2.0 demonstrates that, in most cases, neither assumptions hold. We thus propose a light-weight mechanism that dynamically learns what users are interested in based on the tags they use when they create and/or consume content. To maximise the chances of bringing relevant content to interested users, we apply a tag-expansion technique to enrich content descriptions beyond the folksonomy used by a single user to those spoken by the local community. We integrate this approach within a source-based DTN protocol we have previously developed, and evaluate its performance via simulation using real datasets.","PeriodicalId":404958,"journal":{"name":"CHANTS '10","volume":"46 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134487367","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}
Opportunistic Networking allows wireless nodes to exchange data and information of interest with peers in communication range. These nodes form a large, dynamic, multi-hop network on the fly. Challenging optimization problems arise, such as end-to-end routing, resource allocation (e.g., for buffer space and bandwidth), content placement etc., exacerbated by the lack of end-to-end connectivity. While globally optimal solutions are normally sought in network optimization, node actions and decisions in this context are inherently local. As a result, most solutions proposed rely on local heuristics without any guarantees about their convergence properties towards a desired global outcome. In this paper, we argue that the framework of Markov Chain Monte Carlo (MCMC) optimization can be applied to many problems in Opportunistic Networking, providing efficient local algorithms that provably converge to a globally optimal solution. As a case study, we use the problem of optimal relay selection for group communication (e.g., multicast), based on node contact patterns.
{"title":"Distributed stochastic optimization in opportunistic networks: the case of optimal relay selection","authors":"Andreea Hossmann-Picu, T. Spyropoulos","doi":"10.1145/1859934.1859939","DOIUrl":"https://doi.org/10.1145/1859934.1859939","url":null,"abstract":"Opportunistic Networking allows wireless nodes to exchange data and information of interest with peers in communication range. These nodes form a large, dynamic, multi-hop network on the fly. Challenging optimization problems arise, such as end-to-end routing, resource allocation (e.g., for buffer space and bandwidth), content placement etc., exacerbated by the lack of end-to-end connectivity. While globally optimal solutions are normally sought in network optimization, node actions and decisions in this context are inherently local. As a result, most solutions proposed rely on local heuristics without any guarantees about their convergence properties towards a desired global outcome. In this paper, we argue that the framework of Markov Chain Monte Carlo (MCMC) optimization can be applied to many problems in Opportunistic Networking, providing efficient local algorithms that provably converge to a globally optimal solution. As a case study, we use the problem of optimal relay selection for group communication (e.g., multicast), based on node contact patterns.","PeriodicalId":404958,"journal":{"name":"CHANTS '10","volume":"197 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132281391","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}
B. Han, Pan Hui, V. S. A. Kumar, M. Marathe, Guanhong Pei, A. Srinivasan
Due to the increasing popularity of various applications for smartphones, 3G networks are currently overloaded by mobile data traffic. Offloading cellular traffic through opportunistic communications is a promising solution to partially solve this problem, because there is no monetary cost for it. As a case study, we investigate the target-set selection problem for information delivery in the emerging Mobile Social Networks (MoSoNets). We propose to exploit opportunistic communications to facilitate the information dissemination and thus reduce the amount of cellular traffic. In particular, we study how to select the target set with only k users, such that we can minimize the cellular data traffic. In this scenario, initially the content service providers deliver information over cellular networks to only users in the target set. Then through opportunistic communications, target-users will further propagate the information among all the subscribed users. Finally, service providers will send the information to users who fail to receive it before the delivery deadline (i.e., delay-tolerance threshold). We propose three algorithms, called Greedy, Heuristic, and Random, for this problem and evaluate their performance through an extensive trace-driven simulation study. The simulation results verify the efficiency of these algorithms for both synthetic and real-world mobility traces. For example, the Heuristic algorithm can offload cellular traffic by up to 73.66% for a real-world mobility trace.
{"title":"Cellular traffic offloading through opportunistic communications: a case study","authors":"B. Han, Pan Hui, V. S. A. Kumar, M. Marathe, Guanhong Pei, A. Srinivasan","doi":"10.1145/1859934.1859943","DOIUrl":"https://doi.org/10.1145/1859934.1859943","url":null,"abstract":"Due to the increasing popularity of various applications for smartphones, 3G networks are currently overloaded by mobile data traffic. Offloading cellular traffic through opportunistic communications is a promising solution to partially solve this problem, because there is no monetary cost for it. As a case study, we investigate the target-set selection problem for information delivery in the emerging Mobile Social Networks (MoSoNets). We propose to exploit opportunistic communications to facilitate the information dissemination and thus reduce the amount of cellular traffic. In particular, we study how to select the target set with only k users, such that we can minimize the cellular data traffic.\u0000 In this scenario, initially the content service providers deliver information over cellular networks to only users in the target set. Then through opportunistic communications, target-users will further propagate the information among all the subscribed users. Finally, service providers will send the information to users who fail to receive it before the delivery deadline (i.e., delay-tolerance threshold). We propose three algorithms, called Greedy, Heuristic, and Random, for this problem and evaluate their performance through an extensive trace-driven simulation study. The simulation results verify the efficiency of these algorithms for both synthetic and real-world mobility traces. For example, the Heuristic algorithm can offload cellular traffic by up to 73.66% for a real-world mobility trace.","PeriodicalId":404958,"journal":{"name":"CHANTS '10","volume":"58 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126542304","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}
This demo shows a relative time implementation for the delay-tolerant networking architecture. In this system, bundle age is used to track expiration in situations where ac curate real world time is not available. The relative time functionality is implemented on top of the DTN2 reference implementation and the Bytewalla Android implementation which allows for its use on commercial mobile devices. Our demo, using multiple smartphones and netbooks, shows that devices are still able to communicate despite unsynchronized or incorrect clocks.
{"title":"A relative time implementation for delay-tolerant networks","authors":"D. V. Bruggen, Calvin Ardi","doi":"10.1145/1859934.1859954","DOIUrl":"https://doi.org/10.1145/1859934.1859954","url":null,"abstract":"This demo shows a relative time implementation for the delay-tolerant networking architecture. In this system, bundle age is used to track expiration in situations where ac curate real world time is not available. The relative time functionality is implemented on top of the DTN2 reference implementation and the Bytewalla Android implementation which allows for its use on commercial mobile devices. Our demo, using multiple smartphones and netbooks, shows that devices are still able to communicate despite unsynchronized or incorrect clocks.","PeriodicalId":404958,"journal":{"name":"CHANTS '10","volume":"791 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123003527","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}
Over the last ten years interest in the field of delay and disruption-tolerant, challenged, and opportunistic networks has grown dramatically. Communication protocols originally designed to accommodate communication in the intermittent and high-delay environment of deep space have been applied to sensor networks, battlefield networks, and more recently, peer-to-peer content sharing and social networking. However despite a flurry of creative proposals for ways this new technology could be used, and the diaspora of mobile phone apps whose sole novelty is to mimic the behavior of an opportunistic network, the technology has not found its way into common use, even among the researchers who specialize in the field. We are developing competitive challenges, or games, in which participants would use BP in order to accomplish some nominal goal. By making the activity competitive and offering some reward to the best performers, we hope to get large numbers of conference attendees communicating with BP on a daily basis. In the process people will begin to discover how DTN technology and associated applications can be used to meet their own communication needs. Though these games do provide some entertainment value, the point of the activity is to get people using DTNs to communicate in a real environment, to stress test the available DTN software, and to spur the development of DTN-capable applications.
{"title":"Making bundle protocol into a game","authors":"B. Walker","doi":"10.1145/1859934.1859953","DOIUrl":"https://doi.org/10.1145/1859934.1859953","url":null,"abstract":"Over the last ten years interest in the field of delay and disruption-tolerant, challenged, and opportunistic networks has grown dramatically. Communication protocols originally designed to accommodate communication in the intermittent and high-delay environment of deep space have been applied to sensor networks, battlefield networks, and more recently, peer-to-peer content sharing and social networking. However despite a flurry of creative proposals for ways this new technology could be used, and the diaspora of mobile phone apps whose sole novelty is to mimic the behavior of an opportunistic network, the technology has not found its way into common use, even among the researchers who specialize in the field.\u0000 We are developing competitive challenges, or games, in which participants would use BP in order to accomplish some nominal goal. By making the activity competitive and offering some reward to the best performers, we hope to get large numbers of conference attendees communicating with BP on a daily basis. In the process people will begin to discover how DTN technology and associated applications can be used to meet their own communication needs.\u0000 Though these games do provide some entertainment value, the point of the activity is to get people using DTNs to communicate in a real environment, to stress test the available DTN software, and to spur the development of DTN-capable applications.","PeriodicalId":404958,"journal":{"name":"CHANTS '10","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115735045","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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