Pub Date : 2002-07-01DOI: 10.1109/ISCC.2002.1021781
A. Boudani, Bernard A. Cousin
In this paper, we present a new approach to construct multicast trees in MPLS networks. This approach utilizes MPLS LSP between multicast tree branching node routers in order to reduce forwarding states and enhance scalability. In our approach only routers that are acting as multicast tree branching node for a group need to keep the forwarding state for that group. All other non-branching node routers simply forward data packets over traffic engineered unicast routes using MPLS LSP. We can deduce that our approach can be largely deployed because it uses for multicast traffic the same unicast MPLS forwarding scheme. In this paper we briefly discuss MPLS, the multicast scalability problem, merging the two technologies, related works and different techniques for forwarding state reduction. We evaluate the approach and present some related issues to conclude finally that it is feasible and promising.
{"title":"A new approach to construct multicast trees in MPLS networks","authors":"A. Boudani, Bernard A. Cousin","doi":"10.1109/ISCC.2002.1021781","DOIUrl":"https://doi.org/10.1109/ISCC.2002.1021781","url":null,"abstract":"In this paper, we present a new approach to construct multicast trees in MPLS networks. This approach utilizes MPLS LSP between multicast tree branching node routers in order to reduce forwarding states and enhance scalability. In our approach only routers that are acting as multicast tree branching node for a group need to keep the forwarding state for that group. All other non-branching node routers simply forward data packets over traffic engineered unicast routes using MPLS LSP. We can deduce that our approach can be largely deployed because it uses for multicast traffic the same unicast MPLS forwarding scheme. In this paper we briefly discuss MPLS, the multicast scalability problem, merging the two technologies, related works and different techniques for forwarding state reduction. We evaluate the approach and present some related issues to conclude finally that it is feasible and promising.","PeriodicalId":261743,"journal":{"name":"Proceedings ISCC 2002 Seventh International Symposium on Computers and Communications","volume":"49 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114667574","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 : 2002-07-01DOI: 10.1109/ISCC.2002.1021753
Hungjen Wang, E. Modiano, M. Médard
We propose a new protection scheme, which we term partial path protection (PPP), to select end-to-end backup paths using local information about network failures. PPP designates a different restoration path for every link failure on each primary path. PPP also allows reuse of operational segments of the original primary path in the protection path. A novel approach used in this paper is that of a dynamic call-by-call model with blocking probability as the performance metric, this model is in contrast with traditional capacity-efficiency measurement for batch call arrivals. Additionally, we show that a simple method based on shortest path routing for which primary paths are selected first is more effective than a greedy approach that minimizes, for each call arrival, the number of wavelengths used by the primary and backup path jointly.
{"title":"Partial path protection for WDM networks: end-to-end recovery using local failure information","authors":"Hungjen Wang, E. Modiano, M. Médard","doi":"10.1109/ISCC.2002.1021753","DOIUrl":"https://doi.org/10.1109/ISCC.2002.1021753","url":null,"abstract":"We propose a new protection scheme, which we term partial path protection (PPP), to select end-to-end backup paths using local information about network failures. PPP designates a different restoration path for every link failure on each primary path. PPP also allows reuse of operational segments of the original primary path in the protection path. A novel approach used in this paper is that of a dynamic call-by-call model with blocking probability as the performance metric, this model is in contrast with traditional capacity-efficiency measurement for batch call arrivals. Additionally, we show that a simple method based on shortest path routing for which primary paths are selected first is more effective than a greedy approach that minimizes, for each call arrival, the number of wavelengths used by the primary and backup path jointly.","PeriodicalId":261743,"journal":{"name":"Proceedings ISCC 2002 Seventh International Symposium on Computers and Communications","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114408291","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 : 2002-07-01DOI: 10.1109/ISCC.2002.1021760
M. Scarpa, M. Villari, A. Zaia, A. Puliafito
This paper provides an experimental and analytical evaluation of the client-server, remote evaluation and mobile agent communication paradigms. Our purpose is that of identifying the environmental situations in which such paradigms should be preferred or combined in order to optimize the performances of a distributed system. The scenario selected for the analysis is information retrieval on the WWW. An analytical evaluation throughout the solution of non-Markovian Petri net models is provided.
{"title":"From client/server to mobile agents: an in-depth analysis of the related performance aspects","authors":"M. Scarpa, M. Villari, A. Zaia, A. Puliafito","doi":"10.1109/ISCC.2002.1021760","DOIUrl":"https://doi.org/10.1109/ISCC.2002.1021760","url":null,"abstract":"This paper provides an experimental and analytical evaluation of the client-server, remote evaluation and mobile agent communication paradigms. Our purpose is that of identifying the environmental situations in which such paradigms should be preferred or combined in order to optimize the performances of a distributed system. The scenario selected for the analysis is information retrieval on the WWW. An analytical evaluation throughout the solution of non-Markovian Petri net models is provided.","PeriodicalId":261743,"journal":{"name":"Proceedings ISCC 2002 Seventh International Symposium on Computers and Communications","volume":"62 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116822324","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 : 2002-07-01DOI: 10.1109/ISCC.2002.1021711
M. Kazantzidis, M. Gerla
Higher layer protocols in wireless networks need to dynamically adapt to observed network response. The common approach is that each session employs end-to-end monitoring to estimate quantities of interest, like delay, delay jitter and available bandwidth. A less conventional approach is to employ lower layer explicit feedback mechanisms in place or in aid of end-to-end efforts. Available bandwidth measurements are known to follow multi-modal distributions and therefore are especially difficult to measure and filter, even in wired networks. In 802.11-based multi-hop networks obtaining usable end-to-end measurements is questionable. They are affected by a combination of a large number of transient variables due to the virtual carrier sense, head of line problems on each link and mobility. Motivated by this, we are developing a network explicit feedback mechanism. Our study of this accurate network feedback architecture aids in the cost/benefit analysis of an important trade-off: deployment of network support mechanisms for transports and QoS, versus the simple, scalable and easily deployable end-to-end solution. We test our solution in: (i) multimedia adaptation and (ii) measurement based call admission. Loss rates of end-to-end adaptive video and audio connections have been more than 4 times higher than in the network feedback case. A simple call admission strategy has also proved very effective using the feedback. In our experiments it led the network to a maximal performance and stable operating point.
{"title":"End-to-end versus explicit feedback measurement in 802.11 networks","authors":"M. Kazantzidis, M. Gerla","doi":"10.1109/ISCC.2002.1021711","DOIUrl":"https://doi.org/10.1109/ISCC.2002.1021711","url":null,"abstract":"Higher layer protocols in wireless networks need to dynamically adapt to observed network response. The common approach is that each session employs end-to-end monitoring to estimate quantities of interest, like delay, delay jitter and available bandwidth. A less conventional approach is to employ lower layer explicit feedback mechanisms in place or in aid of end-to-end efforts. Available bandwidth measurements are known to follow multi-modal distributions and therefore are especially difficult to measure and filter, even in wired networks. In 802.11-based multi-hop networks obtaining usable end-to-end measurements is questionable. They are affected by a combination of a large number of transient variables due to the virtual carrier sense, head of line problems on each link and mobility. Motivated by this, we are developing a network explicit feedback mechanism. Our study of this accurate network feedback architecture aids in the cost/benefit analysis of an important trade-off: deployment of network support mechanisms for transports and QoS, versus the simple, scalable and easily deployable end-to-end solution. We test our solution in: (i) multimedia adaptation and (ii) measurement based call admission. Loss rates of end-to-end adaptive video and audio connections have been more than 4 times higher than in the network feedback case. A simple call admission strategy has also proved very effective using the feedback. In our experiments it led the network to a maximal performance and stable operating point.","PeriodicalId":261743,"journal":{"name":"Proceedings ISCC 2002 Seventh International Symposium on Computers and Communications","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115368410","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 : 2002-07-01DOI: 10.1109/ISCC.2002.1021668
P. Bellavista, Antonio Corradi
The increasing diffusion of mobile computing and of portable devices with wireless connectivity identifies new challenging scenarios for service provisioning. The access from devices with limited heterogeneous capabilities to traditional and novel Internet services requires new infrastructures capable of integrating with the fixed network and of supporting service tailoring/adaptation. The paper presents a mobile agent-based middleware for the distribution of video on demand (VoD) to portable devices. Mobile agents can act as device proxies over the fixed network, can negotiate the proper QoS level and can dynamically tailor VoD flows depending on profiles of terminal characteristics and user preferences. The paper also describes the design and implementation of a motion picture-information service prototype, built on top of the proposed middleware. The prototype shows the feasibility of distributing motion picture trailers ubiquitously even to portable devices with strict constraints on computing power and visualization capabilities, e.g., Palm personal digital assistants hosting the Java KVM/CLDC/MIDP software suite.
{"title":"How to support Internet-based distribution of video on demand to portable devices","authors":"P. Bellavista, Antonio Corradi","doi":"10.1109/ISCC.2002.1021668","DOIUrl":"https://doi.org/10.1109/ISCC.2002.1021668","url":null,"abstract":"The increasing diffusion of mobile computing and of portable devices with wireless connectivity identifies new challenging scenarios for service provisioning. The access from devices with limited heterogeneous capabilities to traditional and novel Internet services requires new infrastructures capable of integrating with the fixed network and of supporting service tailoring/adaptation. The paper presents a mobile agent-based middleware for the distribution of video on demand (VoD) to portable devices. Mobile agents can act as device proxies over the fixed network, can negotiate the proper QoS level and can dynamically tailor VoD flows depending on profiles of terminal characteristics and user preferences. The paper also describes the design and implementation of a motion picture-information service prototype, built on top of the proposed middleware. The prototype shows the feasibility of distributing motion picture trailers ubiquitously even to portable devices with strict constraints on computing power and visualization capabilities, e.g., Palm personal digital assistants hosting the Java KVM/CLDC/MIDP software suite.","PeriodicalId":261743,"journal":{"name":"Proceedings ISCC 2002 Seventh International Symposium on Computers and Communications","volume":"54 4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124744057","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 : 2002-07-01DOI: 10.1109/ISCC.2002.1021699
O. Tomarchio, G. Modica, D. Vecchio, Dániel Hoványi, Erwin Postmann, Hans Portschy
The third-generation mobile networks will provide new and advanced services for mobile users: in this context, the virtual home environment (VHE), currently being widely investigated, is a concept which will enable users to access and personalize their subscribed services whatever the terminal they use and whatever the underlying network used. Adaptation is a key feature for these architectures: services should be designed and developed only once, independently of the actual user terminal and its capabilities. We show how an adaptation framework could benefit of code mobility, especially for services providing multimedia content. The base architecture is shown, and specific scenarios are discussed. The work in this paper has been done in the context of the European IST project VESPER.
{"title":"Code mobility for adaptation of multimedia services in a VHE environment","authors":"O. Tomarchio, G. Modica, D. Vecchio, Dániel Hoványi, Erwin Postmann, Hans Portschy","doi":"10.1109/ISCC.2002.1021699","DOIUrl":"https://doi.org/10.1109/ISCC.2002.1021699","url":null,"abstract":"The third-generation mobile networks will provide new and advanced services for mobile users: in this context, the virtual home environment (VHE), currently being widely investigated, is a concept which will enable users to access and personalize their subscribed services whatever the terminal they use and whatever the underlying network used. Adaptation is a key feature for these architectures: services should be designed and developed only once, independently of the actual user terminal and its capabilities. We show how an adaptation framework could benefit of code mobility, especially for services providing multimedia content. The base architecture is shown, and specific scenarios are discussed. The work in this paper has been done in the context of the European IST project VESPER.","PeriodicalId":261743,"journal":{"name":"Proceedings ISCC 2002 Seventh International Symposium on Computers and Communications","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130142888","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 : 2002-07-01DOI: 10.1109/ISCC.2002.1021725
M. Benaissa, V. Lecuire, F. Lepage
Mobility in an ad hoc network affects packet jitter and leads to handoff delays. We present a new playout delay adjustment algorithm of audio packets in mobile ad hoc networks for interactive audio applications. This algorithm has two modes of operation where playout delay is adapted differently, depending on whether or not a handoff has been detected. Interactivity constraints of audio applications are taken into account for the adjustments.
{"title":"An algorithm for playout delay adjustment for interactive audio applications in mobile ad hoc networks","authors":"M. Benaissa, V. Lecuire, F. Lepage","doi":"10.1109/ISCC.2002.1021725","DOIUrl":"https://doi.org/10.1109/ISCC.2002.1021725","url":null,"abstract":"Mobility in an ad hoc network affects packet jitter and leads to handoff delays. We present a new playout delay adjustment algorithm of audio packets in mobile ad hoc networks for interactive audio applications. This algorithm has two modes of operation where playout delay is adapted differently, depending on whether or not a handoff has been detected. Interactivity constraints of audio applications are taken into account for the adjustments.","PeriodicalId":261743,"journal":{"name":"Proceedings ISCC 2002 Seventh International Symposium on Computers and Communications","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128538835","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 : 2002-07-01DOI: 10.1109/ISCC.2002.1021721
Domenico Cotroneo, L. Peluso, S. Romano, G. Ventre
Denial of service (DoS) attacks represent, in today's Internet, one of the most complex issues to address. A session is under a DoS attack if it cannot achieve its intended throughput due to the misbehavior of other sessions. Many research studies dealt with DoS, proposing models and/or architectures mostly based on an attack prevention approach. Prevention techniques lead to different models, each suitable for a single type of misbehavior, but do not guarantee the protection of a system from a more general DoS attack. We analyze the fundamental requirements to be satisfied in order to protect hosts and routers from any form of distributed DoS (DDoS). Then we propose a network signaling protocol, named active security protocol(ASP), which satisfies most of the defined requirements. ASP provides an active protection from a DDoS attack, being able to adapt its defense strategies to the current type of violation. Protocol specification and design are performed using an object oriented methodology: we used Unified Modeling Language (UML) as a software description language.
{"title":"An active security protocol against DoS attacks","authors":"Domenico Cotroneo, L. Peluso, S. Romano, G. Ventre","doi":"10.1109/ISCC.2002.1021721","DOIUrl":"https://doi.org/10.1109/ISCC.2002.1021721","url":null,"abstract":"Denial of service (DoS) attacks represent, in today's Internet, one of the most complex issues to address. A session is under a DoS attack if it cannot achieve its intended throughput due to the misbehavior of other sessions. Many research studies dealt with DoS, proposing models and/or architectures mostly based on an attack prevention approach. Prevention techniques lead to different models, each suitable for a single type of misbehavior, but do not guarantee the protection of a system from a more general DoS attack. We analyze the fundamental requirements to be satisfied in order to protect hosts and routers from any form of distributed DoS (DDoS). Then we propose a network signaling protocol, named active security protocol(ASP), which satisfies most of the defined requirements. ASP provides an active protection from a DDoS attack, being able to adapt its defense strategies to the current type of violation. Protocol specification and design are performed using an object oriented methodology: we used Unified Modeling Language (UML) as a software description language.","PeriodicalId":261743,"journal":{"name":"Proceedings ISCC 2002 Seventh International Symposium on Computers and Communications","volume":"03 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127228083","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 : 2002-07-01DOI: 10.1109/ISCC.2002.1021693
Zhenghua Fu, Xiaoqiao Meng, Songwu Lu
Several recent studies have indicated that TCP performance degrades significantly in mobile ad hoc networks. This paper examines how badly TCP may perform in such networks and provides a quantitative characterization of this performance gap. Previous approaches typically made comparisons by ignoring the inherent dynamics such as mobility, channel error and shared-channel contention. Our work provides a realistic, achievable TCP throughput upper bound, and may serve as a benchmark for future TCP modifications in ad hoc networks. Our simulation findings indicate that node mobility, especially mobility-induced network disconnection and reconnection events, has the most significant impact on TCP performance. TCP NewReno merely achieves about 10% of a reference TCPs throughput in such cases. As mobility increases, the relative throughput drop ranges from almost 0% in the static case to 1000% in a highly mobile scenario (mobility speed is 20 m/sec). In contrast, congestion and mild channel error (say, 1%) have less visible effect on TCP (with less than 10% performance drop compared with the reference TCP).
{"title":"How bad TCP can perform in mobile ad hoc networks","authors":"Zhenghua Fu, Xiaoqiao Meng, Songwu Lu","doi":"10.1109/ISCC.2002.1021693","DOIUrl":"https://doi.org/10.1109/ISCC.2002.1021693","url":null,"abstract":"Several recent studies have indicated that TCP performance degrades significantly in mobile ad hoc networks. This paper examines how badly TCP may perform in such networks and provides a quantitative characterization of this performance gap. Previous approaches typically made comparisons by ignoring the inherent dynamics such as mobility, channel error and shared-channel contention. Our work provides a realistic, achievable TCP throughput upper bound, and may serve as a benchmark for future TCP modifications in ad hoc networks. Our simulation findings indicate that node mobility, especially mobility-induced network disconnection and reconnection events, has the most significant impact on TCP performance. TCP NewReno merely achieves about 10% of a reference TCPs throughput in such cases. As mobility increases, the relative throughput drop ranges from almost 0% in the static case to 1000% in a highly mobile scenario (mobility speed is 20 m/sec). In contrast, congestion and mild channel error (say, 1%) have less visible effect on TCP (with less than 10% performance drop compared with the reference TCP).","PeriodicalId":261743,"journal":{"name":"Proceedings ISCC 2002 Seventh International Symposium on Computers and Communications","volume":"727 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134174829","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 : 2002-07-01DOI: 10.1109/ISCC.2002.1021763
P. Barta, F. Németh, R. Szabó, J. Bíró
This paper proposes several call admission control (CAC) algorithms for tandem networks that employ the generalized processor sharing (GPS) scheduling discipline, and also points out important network issues that are crucial in the design of network level CAC algorithms for GPS. Sessions are considered to be leaky bucket constrained and are regulated by traffic shapers at each network node. The end-to-end service curve approach of Barta et al. (2001) is used to carry out the analytical framework of our algorithms. Different CAC algorithms are developed to support different session treatment strategies and diverse server capacities. The proposed algorithms follow different end-to-end delay provisioning strategies whose performance is compared through numerical examples.
{"title":"Call admission control algorithms for tandem generalized processor sharing networks","authors":"P. Barta, F. Németh, R. Szabó, J. Bíró","doi":"10.1109/ISCC.2002.1021763","DOIUrl":"https://doi.org/10.1109/ISCC.2002.1021763","url":null,"abstract":"This paper proposes several call admission control (CAC) algorithms for tandem networks that employ the generalized processor sharing (GPS) scheduling discipline, and also points out important network issues that are crucial in the design of network level CAC algorithms for GPS. Sessions are considered to be leaky bucket constrained and are regulated by traffic shapers at each network node. The end-to-end service curve approach of Barta et al. (2001) is used to carry out the analytical framework of our algorithms. Different CAC algorithms are developed to support different session treatment strategies and diverse server capacities. The proposed algorithms follow different end-to-end delay provisioning strategies whose performance is compared through numerical examples.","PeriodicalId":261743,"journal":{"name":"Proceedings ISCC 2002 Seventh International Symposium on Computers and Communications","volume":"47 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131671181","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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