Pub Date : 2002-11-17DOI: 10.1109/GLOCOM.2002.1189090
Yu Cheng, W. Zhuang
We investigate the statistical multiplexing and admission control for a partitioned buffer, where the traffic is generated by multiclass Markov-modulated fluid sources. Each of the sources has J (> 1) QoS classes at each state. The QoS is described by the packet loss probability for each class. The buffer is partitioned with J - 1 thresholds to provide the J loss priorities. In the asymptotic regime of large buffers and small loss probabilities, the effective bandwidth is defined and derived based on fluid model analysis and buffer partitioning optimization, which is the minimal channel capacity required to serve a multiclass Markovian source while guaranteeing the QoS requirements of all the classes. For heterogeneous multiclass Markovian sources, numerical studies demonstrate that the proposed effective bandwidth can be used for admission control in an additive way.
{"title":"Effective bandwidth of multiclass Markovian traffic sources and admission control with dynamic buffer partitioning","authors":"Yu Cheng, W. Zhuang","doi":"10.1109/GLOCOM.2002.1189090","DOIUrl":"https://doi.org/10.1109/GLOCOM.2002.1189090","url":null,"abstract":"We investigate the statistical multiplexing and admission control for a partitioned buffer, where the traffic is generated by multiclass Markov-modulated fluid sources. Each of the sources has J (> 1) QoS classes at each state. The QoS is described by the packet loss probability for each class. The buffer is partitioned with J - 1 thresholds to provide the J loss priorities. In the asymptotic regime of large buffers and small loss probabilities, the effective bandwidth is defined and derived based on fluid model analysis and buffer partitioning optimization, which is the minimal channel capacity required to serve a multiclass Markovian source while guaranteeing the QoS requirements of all the classes. For heterogeneous multiclass Markovian sources, numerical studies demonstrate that the proposed effective bandwidth can be used for admission control in an additive way.","PeriodicalId":415837,"journal":{"name":"Global Telecommunications Conference, 2002. GLOBECOM '02. IEEE","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116857420","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 : 2002-11-17DOI: 10.1109/GLOCOM.2002.1188141
Wajih A. Abu-Al-Saud, Gordon L. Stüber
A new sample rate conversion (SRC) method for software radio (SWR) systems is proposed. The method, which uses the window filter design and Lagrange functions, requires fewer computations than other SRC methods over a range of SRC factors for the wideband and high dynamic range signals that are typical of SWR systems. The computational requirements of the proposed SRC method and other SRC methods are compared and simulation results of the proposed method are discussed.
{"title":"Efficient sample rate conversion for software radio systems","authors":"Wajih A. Abu-Al-Saud, Gordon L. Stüber","doi":"10.1109/GLOCOM.2002.1188141","DOIUrl":"https://doi.org/10.1109/GLOCOM.2002.1188141","url":null,"abstract":"A new sample rate conversion (SRC) method for software radio (SWR) systems is proposed. The method, which uses the window filter design and Lagrange functions, requires fewer computations than other SRC methods over a range of SRC factors for the wideband and high dynamic range signals that are typical of SWR systems. The computational requirements of the proposed SRC method and other SRC methods are compared and simulation results of the proposed method are discussed.","PeriodicalId":415837,"journal":{"name":"Global Telecommunications Conference, 2002. GLOBECOM '02. IEEE","volume":"02 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129958274","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 : 2002-11-17DOI: 10.1109/GLOCOM.2002.1188357
Xiaojing Huang, Yunxin Li
A family of complete complementary sets of sequences with closed-form expression is presented in this paper. Firstly, by introducing the notion of Golay (1961)-paired matrix and providing its synthesis algorithms, an orthogonal Golay-paired matrix called Golay-paired Hadamard matrix is derived. Then, general procedures for constructing mutually orthogonal Golay-paired matrices are proposed. Finally, the complete complementary sets of sequences represented by Golay-paired Hadamard matrices are generated and their scalability is illustrated. The unique properties of this new family of scalable complete complementary sets of sequences make it an ideal candidate for applications in future advanced signal processing and communications systems.
{"title":"Scalable complete complementary sets of sequences","authors":"Xiaojing Huang, Yunxin Li","doi":"10.1109/GLOCOM.2002.1188357","DOIUrl":"https://doi.org/10.1109/GLOCOM.2002.1188357","url":null,"abstract":"A family of complete complementary sets of sequences with closed-form expression is presented in this paper. Firstly, by introducing the notion of Golay (1961)-paired matrix and providing its synthesis algorithms, an orthogonal Golay-paired matrix called Golay-paired Hadamard matrix is derived. Then, general procedures for constructing mutually orthogonal Golay-paired matrices are proposed. Finally, the complete complementary sets of sequences represented by Golay-paired Hadamard matrices are generated and their scalability is illustrated. The unique properties of this new family of scalable complete complementary sets of sequences make it an ideal candidate for applications in future advanced signal processing and communications systems.","PeriodicalId":415837,"journal":{"name":"Global Telecommunications Conference, 2002. GLOBECOM '02. IEEE","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128315351","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 : 2002-11-17DOI: 10.1109/GLOCOM.2002.1188369
A. Medles, D. Slock
The use of multiple transmit and receive antennas allows to transmit multiple signal streams in parallel and hence to increase communication capacity. Apart from capacity, the MIMO channel also offers potentially a large number of diversity sources. To exploit these diversity degrees, and hence enhance outage capacity, bit interleaved coded modulation is now a classical solution. In this paper we propose to exploit the diversity sources by linear precoding, to turn the fading channel into a non-fading one. Additional channel coding then only serves to enhance robustness against noise. To streamline the processing and analysis, the linear precoding considered here is convolutional instead or blockwise. We particularly focus in this paper on two non-iterative receiver strategies. Performance improvements are shown over conventional VBLAST.
{"title":"Spatial multiplexing by spatiotemporal spreading: receiver considerations","authors":"A. Medles, D. Slock","doi":"10.1109/GLOCOM.2002.1188369","DOIUrl":"https://doi.org/10.1109/GLOCOM.2002.1188369","url":null,"abstract":"The use of multiple transmit and receive antennas allows to transmit multiple signal streams in parallel and hence to increase communication capacity. Apart from capacity, the MIMO channel also offers potentially a large number of diversity sources. To exploit these diversity degrees, and hence enhance outage capacity, bit interleaved coded modulation is now a classical solution. In this paper we propose to exploit the diversity sources by linear precoding, to turn the fading channel into a non-fading one. Additional channel coding then only serves to enhance robustness against noise. To streamline the processing and analysis, the linear precoding considered here is convolutional instead or blockwise. We particularly focus in this paper on two non-iterative receiver strategies. Performance improvements are shown over conventional VBLAST.","PeriodicalId":415837,"journal":{"name":"Global Telecommunications Conference, 2002. GLOBECOM '02. IEEE","volume":"140 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128610552","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 : 2002-11-17DOI: 10.1109/GLOCOM.2002.1189140
J. Kuri, N. Puech, M. Gagnaire, E. Dotaro
We investigate the problem of routing a set of lightpath demands for which the start and end dates may be planned. We call this type of requests foreseeable lightpath demands or FLDs. In a transport network, FLDs correspond, for example, to clients' requests for pre-provisioned bandwidth capacity such as fixed-bandwidth pipes for bulk data transfers during the night, extra VPN bandwidth used during peak office working time, etc. Since in some cases the FLDs are not all simultaneous in time, it is possible to reuse physical resources to realize time-disjoint demands. We propose a routing algorithm that takes into account this property to minimize the number of required WDM channels in the physical links of the network. The gain (in term of saved resources) provided by the algorithm, when compared to a shortest path routing strategy, depends both on the spatial and temporal structure of the set of traffic demands and on the structure of the physical network. The routing problem is formulated as a combinatorial optimization problem. A tabu search meta-heuristic algorithm is developed to solve this problem.
{"title":"Routing foreseeable lightpath demands using a tabu search meta-heuristic","authors":"J. Kuri, N. Puech, M. Gagnaire, E. Dotaro","doi":"10.1109/GLOCOM.2002.1189140","DOIUrl":"https://doi.org/10.1109/GLOCOM.2002.1189140","url":null,"abstract":"We investigate the problem of routing a set of lightpath demands for which the start and end dates may be planned. We call this type of requests foreseeable lightpath demands or FLDs. In a transport network, FLDs correspond, for example, to clients' requests for pre-provisioned bandwidth capacity such as fixed-bandwidth pipes for bulk data transfers during the night, extra VPN bandwidth used during peak office working time, etc. Since in some cases the FLDs are not all simultaneous in time, it is possible to reuse physical resources to realize time-disjoint demands. We propose a routing algorithm that takes into account this property to minimize the number of required WDM channels in the physical links of the network. The gain (in term of saved resources) provided by the algorithm, when compared to a shortest path routing strategy, depends both on the spatial and temporal structure of the set of traffic demands and on the structure of the physical network. The routing problem is formulated as a combinatorial optimization problem. A tabu search meta-heuristic algorithm is developed to solve this problem.","PeriodicalId":415837,"journal":{"name":"Global Telecommunications Conference, 2002. GLOBECOM '02. IEEE","volume":"119 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124615022","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 : 2002-11-17DOI: 10.1109/GLOCOM.2002.1188488
P. Fitzpatrick, M. Ivanovich, J. Yin
Cellular radio networks supporting both circuit switched voice and packet switched data services aim to maximise the resource utilisation through efficient sharing of the resource. These sharing algorithms can use pre-emption to give voice service priority over data, thus preserving the grade of service for voice at the expense of delaying data calls. This paper develops models for a pre-emptive voice and data system, with a particular focus on GPRS. The model is based on an assumption of independence between the voice and data traffic. These models allow estimates of (i) the probability that a voice call causes pre-emption of a data call, as well as (ii) the probability that a data call will be delayed due to either being pre-empted by a voice call while in progress or due to not finding free resources at its initial attempt. The results show that a Poisson model for data traffic gives the best results for pre-emption probability when compared with measurements taken from a GSM/GPRS network.
{"title":"Models for pre-emption of packet data by voice in slotted cellular radio networks","authors":"P. Fitzpatrick, M. Ivanovich, J. Yin","doi":"10.1109/GLOCOM.2002.1188488","DOIUrl":"https://doi.org/10.1109/GLOCOM.2002.1188488","url":null,"abstract":"Cellular radio networks supporting both circuit switched voice and packet switched data services aim to maximise the resource utilisation through efficient sharing of the resource. These sharing algorithms can use pre-emption to give voice service priority over data, thus preserving the grade of service for voice at the expense of delaying data calls. This paper develops models for a pre-emptive voice and data system, with a particular focus on GPRS. The model is based on an assumption of independence between the voice and data traffic. These models allow estimates of (i) the probability that a voice call causes pre-emption of a data call, as well as (ii) the probability that a data call will be delayed due to either being pre-empted by a voice call while in progress or due to not finding free resources at its initial attempt. The results show that a Poisson model for data traffic gives the best results for pre-emption probability when compared with measurements taken from a GSM/GPRS network.","PeriodicalId":415837,"journal":{"name":"Global Telecommunications Conference, 2002. GLOBECOM '02. IEEE","volume":"90 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129082182","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 : 2002-11-17DOI: 10.1109/GLOCOM.2002.1189167
Jian Fang, I. Akyildiz
A multicast transport protocol, called TCP Peachtree, is proposed for satellite IP networks. In addition to the acknowledgment implosion and scalability problems appearing in terrestrial wirelined networks, satellite multicasting has additional problems, i.e., low bandwidth feedback link, different multicast topology and congestion control. In TCP Peachtree, the modified B+ tree hierarchical structure is used to form dynamic multicast groups. Local error recovery and ACK aggregations are performed within each subgroup and also via logical subgroups. Two new algorithms, jump start and quick recovery, which are based on a type of low priority segments, called NIL segments, are proposed for congestion control. NIL segments are used to probe the availability of network resources and also for error recovery. Moreover, an ACK filter is also introduced to aggregate ACKs. The simulation results show that the congestion control algorithms in TCP Peachtree outperform TCP NewReno when combined with our hierarchical groups and ACK filter. It is also shown that TCP Peachtree can have very good scalability.
{"title":"A reliable multicast transport protocol for satellite IP networks","authors":"Jian Fang, I. Akyildiz","doi":"10.1109/GLOCOM.2002.1189167","DOIUrl":"https://doi.org/10.1109/GLOCOM.2002.1189167","url":null,"abstract":"A multicast transport protocol, called TCP Peachtree, is proposed for satellite IP networks. In addition to the acknowledgment implosion and scalability problems appearing in terrestrial wirelined networks, satellite multicasting has additional problems, i.e., low bandwidth feedback link, different multicast topology and congestion control. In TCP Peachtree, the modified B+ tree hierarchical structure is used to form dynamic multicast groups. Local error recovery and ACK aggregations are performed within each subgroup and also via logical subgroups. Two new algorithms, jump start and quick recovery, which are based on a type of low priority segments, called NIL segments, are proposed for congestion control. NIL segments are used to probe the availability of network resources and also for error recovery. Moreover, an ACK filter is also introduced to aggregate ACKs. The simulation results show that the congestion control algorithms in TCP Peachtree outperform TCP NewReno when combined with our hierarchical groups and ACK filter. It is also shown that TCP Peachtree can have very good scalability.","PeriodicalId":415837,"journal":{"name":"Global Telecommunications Conference, 2002. GLOBECOM '02. IEEE","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129124189","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 : 2002-11-17DOI: 10.1109/GLOCOM.2002.1188101
Jyri Hämäläinen, R. Wichman
Transmit diversity techniques have received a lot of attention recently, and open-loop and closed-loop downlink transmit diversity modes for two transmit antennas have been included in the 3GPP WCDMA Release 5. System capacity can be increased from that of open-loop modes if the transmitter can be provided additional side information of the downlink channel. In a frequency division duplex (FDD) system this requires a separate feedback channel. Quantization of the feedback messages in closed-loop transmit diversity schemes reduces the performance of the system. However, this effect has not been usually taken into account in the analysis. In this paper we analyze the effect of quantization and deduce an analytic formula for the asymptotic bit error probability of the closed-loop transmit diversity schemes defined in 3GPP WCDMA specification.
{"title":"Asymptotic bit error probabilities of some closed-loop transmit diversity schemes","authors":"Jyri Hämäläinen, R. Wichman","doi":"10.1109/GLOCOM.2002.1188101","DOIUrl":"https://doi.org/10.1109/GLOCOM.2002.1188101","url":null,"abstract":"Transmit diversity techniques have received a lot of attention recently, and open-loop and closed-loop downlink transmit diversity modes for two transmit antennas have been included in the 3GPP WCDMA Release 5. System capacity can be increased from that of open-loop modes if the transmitter can be provided additional side information of the downlink channel. In a frequency division duplex (FDD) system this requires a separate feedback channel. Quantization of the feedback messages in closed-loop transmit diversity schemes reduces the performance of the system. However, this effect has not been usually taken into account in the analysis. In this paper we analyze the effect of quantization and deduce an analytic formula for the asymptotic bit error probability of the closed-loop transmit diversity schemes defined in 3GPP WCDMA specification.","PeriodicalId":415837,"journal":{"name":"Global Telecommunications Conference, 2002. GLOBECOM '02. IEEE","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129239419","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 : 2002-11-17DOI: 10.1109/GLOCOM.2002.1188451
Ashraf Awad, M. W. McKinnon, Raghupathy Sivakumar
In this work, we present an algorithm to analytically estimate the queueing performance of MPEG-2 video using goodput as the metric; where we define goodput as the ratio between the number of cells in uncorrupted and correctly displayable frames to the total number of cells that arrive at the queue. The estimation algorithm is used to evaluate three buffer management schemes. The effect of congestion at the output link is also investigated. The algorithm produces a good approximation of the frame goodput metric and closely agrees with the corresponding simulation results.
{"title":"Estimation of video queueing performance using Markov chains","authors":"Ashraf Awad, M. W. McKinnon, Raghupathy Sivakumar","doi":"10.1109/GLOCOM.2002.1188451","DOIUrl":"https://doi.org/10.1109/GLOCOM.2002.1188451","url":null,"abstract":"In this work, we present an algorithm to analytically estimate the queueing performance of MPEG-2 video using goodput as the metric; where we define goodput as the ratio between the number of cells in uncorrupted and correctly displayable frames to the total number of cells that arrive at the queue. The estimation algorithm is used to evaluate three buffer management schemes. The effect of congestion at the output link is also investigated. The algorithm produces a good approximation of the frame goodput metric and closely agrees with the corresponding simulation results.","PeriodicalId":415837,"journal":{"name":"Global Telecommunications Conference, 2002. GLOBECOM '02. IEEE","volume":"56 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130593848","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 : 2002-11-17DOI: 10.1109/GLOCOM.2002.1188472
N. Malouch, Zhen Liu
We present an approach to analyzing the performance characteristics of TCP sessions in the presence of network routers which deploy the random early detection (RED) mechanism with two in-and-out drop probability functions (RIO). We consider the case with a large number of TCP sessions which use token buckets for marking in and out packets at the entrance of the network. Under some simplifying assumptions, we derive a set of equations that govern the evolution of these TCP sessions and the routers under consideration. The equations are solved numerically using a fixed point method. Our analysis can capture characteristics of both RED and tail drop (TD) mechanisms in the RIO router. Our model is validated through simulations which show that less than 5% error is achieved in most cases. Various performance analyses are carried out using this approach to study the impact of the RIO parameters on the performance characteristics of TCP sessions. The results show that the loss probability threshold of out packets has a significant effect on the TCP throughput and on the average queue length. Setting this parameter consists of trading off between network utilization and fairness among TCP connections. The results also show that the tail drop mechanism is particularly suitable for use in packets to satisfy various QoS constraints.
{"title":"Performance analysis of TCP with RIO routers","authors":"N. Malouch, Zhen Liu","doi":"10.1109/GLOCOM.2002.1188472","DOIUrl":"https://doi.org/10.1109/GLOCOM.2002.1188472","url":null,"abstract":"We present an approach to analyzing the performance characteristics of TCP sessions in the presence of network routers which deploy the random early detection (RED) mechanism with two in-and-out drop probability functions (RIO). We consider the case with a large number of TCP sessions which use token buckets for marking in and out packets at the entrance of the network. Under some simplifying assumptions, we derive a set of equations that govern the evolution of these TCP sessions and the routers under consideration. The equations are solved numerically using a fixed point method. Our analysis can capture characteristics of both RED and tail drop (TD) mechanisms in the RIO router. Our model is validated through simulations which show that less than 5% error is achieved in most cases. Various performance analyses are carried out using this approach to study the impact of the RIO parameters on the performance characteristics of TCP sessions. The results show that the loss probability threshold of out packets has a significant effect on the TCP throughput and on the average queue length. Setting this parameter consists of trading off between network utilization and fairness among TCP connections. The results also show that the tail drop mechanism is particularly suitable for use in packets to satisfy various QoS constraints.","PeriodicalId":415837,"journal":{"name":"Global Telecommunications Conference, 2002. GLOBECOM '02. IEEE","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123798398","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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