Pub Date : 2001-08-15DOI: 10.1109/MASCOT.2001.948858
Kui Wu, J. Harms
A Mobile Ad hoc NETwork (MANET) is a collection of wireless mobile computers forming a temporary network without any existing wire line infrastructure. Due to the dynamic nature of the network topology and the resource constraints, routing in MANETs is a challenging task. Multipath routing can increase end-to-end throughput and provide load balancing in wired networks. However, its advantage is not obvious in MANETs because the traffic along the multiple paths may interfere with each other . In addition, without accurate knowledge of topology, finding multiple disjoint paths is difficult. We propose an on-demand method to efficiently search for multiple node-disjoint paths and present the criteria for selecting the multiple paths. We also perform a simulation study on the proposed method. The purpose of this paper is to present the advantages as well as some difficulties of deploying multipath routing in MANETs.
{"title":"Performance study of a multipath routing method for wireless mobile ad hoc networks","authors":"Kui Wu, J. Harms","doi":"10.1109/MASCOT.2001.948858","DOIUrl":"https://doi.org/10.1109/MASCOT.2001.948858","url":null,"abstract":"A Mobile Ad hoc NETwork (MANET) is a collection of wireless mobile computers forming a temporary network without any existing wire line infrastructure. Due to the dynamic nature of the network topology and the resource constraints, routing in MANETs is a challenging task. Multipath routing can increase end-to-end throughput and provide load balancing in wired networks. However, its advantage is not obvious in MANETs because the traffic along the multiple paths may interfere with each other . In addition, without accurate knowledge of topology, finding multiple disjoint paths is difficult. We propose an on-demand method to efficiently search for multiple node-disjoint paths and present the criteria for selecting the multiple paths. We also perform a simulation study on the proposed method. The purpose of this paper is to present the advantages as well as some difficulties of deploying multipath routing in MANETs.","PeriodicalId":375127,"journal":{"name":"MASCOTS 2001, Proceedings Ninth International Symposium on Modeling, Analysis and Simulation of Computer and Telecommunication Systems","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115395684","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 : 2001-08-15DOI: 10.1109/MASCOT.2001.948891
Brian D. Davison
Simulation is a common technique used by Web researchers and provides many benefits. Verification and validation of a simulator are essential if the results of those simulations are to be believed. Unfortunately, even limited validation of simulators has been uncommon in the Web caching community. In contrast, this paper argues for the validity of a new network and caching simulator by extensively comparing simulated results to both small- and large-scale realworld HTTP traffic. In addition, we describe some of the preparation needed to use a large, well-known trace of Web usage.
{"title":"HTTP simulator validation using real measurements: a case study","authors":"Brian D. Davison","doi":"10.1109/MASCOT.2001.948891","DOIUrl":"https://doi.org/10.1109/MASCOT.2001.948891","url":null,"abstract":"Simulation is a common technique used by Web researchers and provides many benefits. Verification and validation of a simulator are essential if the results of those simulations are to be believed. Unfortunately, even limited validation of simulators has been uncommon in the Web caching community. In contrast, this paper argues for the validity of a new network and caching simulator by extensively comparing simulated results to both small- and large-scale realworld HTTP traffic. In addition, we describe some of the preparation needed to use a large, well-known trace of Web usage.","PeriodicalId":375127,"journal":{"name":"MASCOTS 2001, Proceedings Ninth International Symposium on Modeling, Analysis and Simulation of Computer and Telecommunication Systems","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124394372","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 : 2001-08-15DOI: 10.1109/MASCOT.2001.948871
Liang Guo, M. Crovella, I. Matta
Long-range dependence has been observed in many recent Internet traffic measurements. In addition, some recent studies have shown that under certain network conditions, TCP itself can produce traffic that exhibits dependence over limited timescales, even in the absence of higher-level variability. In this paper, we use a simple Markovian model to argue that when the loss rate is relatively high, TCP's adaptive congestion control mechanism indeed generates traffic with OFF periods exhibiting power-law shape over several timescales and thus introduces pseudo-long-range dependence into the overall traffic. Moreover, we observe that more variable initial retransmission timeout values for different packets introduces more variable packet inter-arrival times, which increases the burstiness of the overall traffic. We can thus explain why a single TCP connection can produce a time-series that can be misidentified as self-similar using standard tests.
{"title":"How does TCP generate pseudo-self-similarity?","authors":"Liang Guo, M. Crovella, I. Matta","doi":"10.1109/MASCOT.2001.948871","DOIUrl":"https://doi.org/10.1109/MASCOT.2001.948871","url":null,"abstract":"Long-range dependence has been observed in many recent Internet traffic measurements. In addition, some recent studies have shown that under certain network conditions, TCP itself can produce traffic that exhibits dependence over limited timescales, even in the absence of higher-level variability. In this paper, we use a simple Markovian model to argue that when the loss rate is relatively high, TCP's adaptive congestion control mechanism indeed generates traffic with OFF periods exhibiting power-law shape over several timescales and thus introduces pseudo-long-range dependence into the overall traffic. Moreover, we observe that more variable initial retransmission timeout values for different packets introduces more variable packet inter-arrival times, which increases the burstiness of the overall traffic. We can thus explain why a single TCP connection can produce a time-series that can be misidentified as self-similar using standard tests.","PeriodicalId":375127,"journal":{"name":"MASCOTS 2001, Proceedings Ninth International Symposium on Modeling, Analysis and Simulation of Computer and Telecommunication Systems","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123298344","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 : 2001-08-15DOI: 10.1109/MASCOT.2001.948881
R. Burns, W. Hineman
File systems that allocate data contiguously often use bitmaps to represent and manage free space. Increases in the size of storage to be managed creates a need for efficient algorithms for searching these bitmaps. We present an algorithm that exploits bit-parallelism, examining all bits within a processor word at the same time, to improve search performance. Measurements of our implementation show that these techniques lead to a 14 times increase in the rate at which bitmap pages can be searched on a 64-bit processor. Trace-driven experiments indicate that overall allocation performance increases by a factor of 3 to 6 on a 32-bit processor. As processors mature, registers become wider and the degree of bit-level parallelism increases, which makes the performance improvements of our search algorithm more substantial.
{"title":"A bit-parallel search algorithm for allocating free space","authors":"R. Burns, W. Hineman","doi":"10.1109/MASCOT.2001.948881","DOIUrl":"https://doi.org/10.1109/MASCOT.2001.948881","url":null,"abstract":"File systems that allocate data contiguously often use bitmaps to represent and manage free space. Increases in the size of storage to be managed creates a need for efficient algorithms for searching these bitmaps. We present an algorithm that exploits bit-parallelism, examining all bits within a processor word at the same time, to improve search performance. Measurements of our implementation show that these techniques lead to a 14 times increase in the rate at which bitmap pages can be searched on a 64-bit processor. Trace-driven experiments indicate that overall allocation performance increases by a factor of 3 to 6 on a 32-bit processor. As processors mature, registers become wider and the degree of bit-level parallelism increases, which makes the performance improvements of our search algorithm more substantial.","PeriodicalId":375127,"journal":{"name":"MASCOTS 2001, Proceedings Ninth International Symposium on Modeling, Analysis and Simulation of Computer and Telecommunication Systems","volume":"102 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114497678","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 : 2001-08-15DOI: 10.1109/MASCOT.2001.948859
Polly Huang, J. Heidemann
We introduce a routing mechanism, referred to as algorithmic routing. It is a viable routing alternative for network simulations with minimal space complexity-O(N). In theory and for simulations the size of the Internet, algorithmic routing has the potential of reducing memory requirements by several orders of magnitude. In practice and through ns-2 simulations on random topologies, we find memory consumption of algorithmic routing exhibits a similar scaling property. However, routes computed by algorithmic routing are not all the shortest. Although we find the relative difference is below 10% for more than 80% of the routes, we are cautious about its applicability to general network simulations. With further discussion on the impacts of the distortion, we derive a set of guidelines and recommend users to apply this technique only when suitable.
{"title":"Minimizing routing state for light-weight network simulation","authors":"Polly Huang, J. Heidemann","doi":"10.1109/MASCOT.2001.948859","DOIUrl":"https://doi.org/10.1109/MASCOT.2001.948859","url":null,"abstract":"We introduce a routing mechanism, referred to as algorithmic routing. It is a viable routing alternative for network simulations with minimal space complexity-O(N). In theory and for simulations the size of the Internet, algorithmic routing has the potential of reducing memory requirements by several orders of magnitude. In practice and through ns-2 simulations on random topologies, we find memory consumption of algorithmic routing exhibits a similar scaling property. However, routes computed by algorithmic routing are not all the shortest. Although we find the relative difference is below 10% for more than 80% of the routes, we are cautious about its applicability to general network simulations. With further discussion on the impacts of the distortion, we derive a set of guidelines and recommend users to apply this technique only when suitable.","PeriodicalId":375127,"journal":{"name":"MASCOTS 2001, Proceedings Ninth International Symposium on Modeling, Analysis and Simulation of Computer and Telecommunication Systems","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130517388","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 : 2001-08-15DOI: 10.1109/MASCOT.2001.948884
Yixin Zhao, Xia Yin, B. Han, Jianping Wu
Based on the analysis and the perception of routing protocols, this paper presents an online test method applicable for the routing protocol test. This method tests the protocol implementation through online observation. It can be performed in the production field without interfering with the network and possesses quite a lot of other beneficial features. With the key techniques worked out, the target and the framework of an online test system (OLTS) are put forward. The OLTS exploits the state synchronization algorithm to test the protocol state machine, and tests the exchange and the manipulation of the routing information through topology analysis and internal process simulation. OLTS provides an intuitionistic and friendly graphical user interface and good flexibility. The prototype of the OLTS has been implemented and the test activity about BGP, OSPF and RIP has been performed.
{"title":"Online test system applied in routing protocol test","authors":"Yixin Zhao, Xia Yin, B. Han, Jianping Wu","doi":"10.1109/MASCOT.2001.948884","DOIUrl":"https://doi.org/10.1109/MASCOT.2001.948884","url":null,"abstract":"Based on the analysis and the perception of routing protocols, this paper presents an online test method applicable for the routing protocol test. This method tests the protocol implementation through online observation. It can be performed in the production field without interfering with the network and possesses quite a lot of other beneficial features. With the key techniques worked out, the target and the framework of an online test system (OLTS) are put forward. The OLTS exploits the state synchronization algorithm to test the protocol state machine, and tests the exchange and the manipulation of the routing information through topology analysis and internal process simulation. OLTS provides an intuitionistic and friendly graphical user interface and good flexibility. The prototype of the OLTS has been implemented and the test activity about BGP, OSPF and RIP has been performed.","PeriodicalId":375127,"journal":{"name":"MASCOTS 2001, Proceedings Ninth International Symposium on Modeling, Analysis and Simulation of Computer and Telecommunication Systems","volume":"112 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128095382","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 : 2001-08-15DOI: 10.1109/MASCOT.2001.948872
Xiang Yu, I. Thng, Yuming Jiang
We develop an upper bound on the individual session queue length of long range dependent (LRD) traffic under the generalized processor sharing (GPS) scheduling discipline. This work is based on the analysis of the arrival process of LRD traffic, which is demonstrated to be a Weibull bounded burstiness (WBB) process. Decomposing the GPS system into isolated queues and servers, we are able to obtain the bound on the individual session queue length from their arrival processes. Our work proves that, in different scenarios, different parameters of the upper bound of an individual session queue, such as the index, the asymptotic constant and the decay rate can be affected by other flows existing in the GPS system. Under certain conditions, by carefully choosing the weight parameters, an individual session with LRD traffic input can be well isolated from other flows in a GPS system.
{"title":"Generalized processor sharing with long-range dependent traffic input","authors":"Xiang Yu, I. Thng, Yuming Jiang","doi":"10.1109/MASCOT.2001.948872","DOIUrl":"https://doi.org/10.1109/MASCOT.2001.948872","url":null,"abstract":"We develop an upper bound on the individual session queue length of long range dependent (LRD) traffic under the generalized processor sharing (GPS) scheduling discipline. This work is based on the analysis of the arrival process of LRD traffic, which is demonstrated to be a Weibull bounded burstiness (WBB) process. Decomposing the GPS system into isolated queues and servers, we are able to obtain the bound on the individual session queue length from their arrival processes. Our work proves that, in different scenarios, different parameters of the upper bound of an individual session queue, such as the index, the asymptotic constant and the decay rate can be affected by other flows existing in the GPS system. Under certain conditions, by carefully choosing the weight parameters, an individual session with LRD traffic input can be well isolated from other flows in a GPS system.","PeriodicalId":375127,"journal":{"name":"MASCOTS 2001, Proceedings Ninth International Symposium on Modeling, Analysis and Simulation of Computer and Telecommunication Systems","volume":"53 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132483711","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 : 2001-08-15DOI: 10.1109/MASCOT.2001.948866
J. Hines
Summary form only given, as follows. The design process is discussed as it is done today and the author shows through examples why we do not do it correctly. The place for simulation in the design process is emphasized and how it is not applied very well, consistently, or enough throughout the design process is highlighted.
{"title":"Design-why we don't do it right","authors":"J. Hines","doi":"10.1109/MASCOT.2001.948866","DOIUrl":"https://doi.org/10.1109/MASCOT.2001.948866","url":null,"abstract":"Summary form only given, as follows. The design process is discussed as it is done today and the author shows through examples why we do not do it correctly. The place for simulation in the design process is emphasized and how it is not applied very well, consistently, or enough throughout the design process is highlighted.","PeriodicalId":375127,"journal":{"name":"MASCOTS 2001, Proceedings Ninth International Symposium on Modeling, Analysis and Simulation of Computer and Telecommunication Systems","volume":"47 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126579160","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 : 2001-08-15DOI: 10.1109/MASCOT.2001.948874
F. Quaglia, Andrea Santoro, B. Ciciani
Recently a Checkpointing and Communication Library (CCL) for optimistic simulation on Myrinet based network of workstations (NOWs) has been presented. CCL offloads checkpoint operations from the CPU by charging them to a programmable DMA engine on the Myrinet network card. CCL includes also functionalities for freezing the simulation application on demand, which can be used for data consistency maintenance (for example when a state buffer needs to be accessed for further modifications while a DMA based checkpoint operation involving it is still in progress). Programming the DMA to perform a checkpoint operation by transferring large data blocks in a single burst allows the latency of any checkpoint operation to be kept low. This reduces the probability for application freezing to really occur On the other hand, transferring large data blocks in a single burst might cause negative interference on communication since that DMA (and other circuitry) cannot be used for communication functionalities until the currently executed data transfer is not yet completed. In this paper we present a detailed identification of the effects of the burst length, from which we outline a set of relevant phenomena to take into account in order to determine a compile time suited value for the burst length itself. We also report measures quantifying these phenomena for the case of a PC cluster. Actually, the data indicate that communication functionalities do not suffer from the use of non-minimal burst lengths for checkpoint operations, thus pointing out how, if well tuned, CCL provides highly effective, CPU off-loaded, checkpointing functionalities.
{"title":"Tuning of the Checkpointing and Communication Library for optimistic simulation on Myrinet based NOWs","authors":"F. Quaglia, Andrea Santoro, B. Ciciani","doi":"10.1109/MASCOT.2001.948874","DOIUrl":"https://doi.org/10.1109/MASCOT.2001.948874","url":null,"abstract":"Recently a Checkpointing and Communication Library (CCL) for optimistic simulation on Myrinet based network of workstations (NOWs) has been presented. CCL offloads checkpoint operations from the CPU by charging them to a programmable DMA engine on the Myrinet network card. CCL includes also functionalities for freezing the simulation application on demand, which can be used for data consistency maintenance (for example when a state buffer needs to be accessed for further modifications while a DMA based checkpoint operation involving it is still in progress). Programming the DMA to perform a checkpoint operation by transferring large data blocks in a single burst allows the latency of any checkpoint operation to be kept low. This reduces the probability for application freezing to really occur On the other hand, transferring large data blocks in a single burst might cause negative interference on communication since that DMA (and other circuitry) cannot be used for communication functionalities until the currently executed data transfer is not yet completed. In this paper we present a detailed identification of the effects of the burst length, from which we outline a set of relevant phenomena to take into account in order to determine a compile time suited value for the burst length itself. We also report measures quantifying these phenomena for the case of a PC cluster. Actually, the data indicate that communication functionalities do not suffer from the use of non-minimal burst lengths for checkpoint operations, thus pointing out how, if well tuned, CCL provides highly effective, CPU off-loaded, checkpointing functionalities.","PeriodicalId":375127,"journal":{"name":"MASCOTS 2001, Proceedings Ninth International Symposium on Modeling, Analysis and Simulation of Computer and Telecommunication Systems","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124753226","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 : 2001-08-15DOI: 10.1109/MASCOT.2001.948886
A. Medina, Anukool Lakhina, I. Matta, J. Byers
Effective engineering of the Internet is predicated upon a detailed understanding of issues such as the large-scale structure of its underlying physical topology, the manner in which it evolves over time, and the way in which its constituent components contribute to its overall function. Unfortunately, developing a deep understanding of these issues has proven to be a challenging task, since it in turn involves solving difficult problems such as mapping the actual topology, characterizing it, and developing models that capture its emergent behavior. Consequently, even though there are a number of topology models, it is an open question as to how representative the generated topologies they generate are of the actual Internet. Our goal is to produce a topology generation framework which improves the state of the art and is based on the design principles of representativeness, inclusiveness, and interoperability. Representativeness leads to synthetic topologies that accurately reflect many aspects of the actual Internet topology (e.g. hierarchical structure, node degree distribution, etc.). Inclusiveness combines the strengths of as many generation models as possible in a single generation tool. Interoperability provides interfaces to widely-used simulation applications such as ns and SSF and visualization tools like otter. We call such a tool a universal topology generator.
{"title":"BRITE: an approach to universal topology generation","authors":"A. Medina, Anukool Lakhina, I. Matta, J. Byers","doi":"10.1109/MASCOT.2001.948886","DOIUrl":"https://doi.org/10.1109/MASCOT.2001.948886","url":null,"abstract":"Effective engineering of the Internet is predicated upon a detailed understanding of issues such as the large-scale structure of its underlying physical topology, the manner in which it evolves over time, and the way in which its constituent components contribute to its overall function. Unfortunately, developing a deep understanding of these issues has proven to be a challenging task, since it in turn involves solving difficult problems such as mapping the actual topology, characterizing it, and developing models that capture its emergent behavior. Consequently, even though there are a number of topology models, it is an open question as to how representative the generated topologies they generate are of the actual Internet. Our goal is to produce a topology generation framework which improves the state of the art and is based on the design principles of representativeness, inclusiveness, and interoperability. Representativeness leads to synthetic topologies that accurately reflect many aspects of the actual Internet topology (e.g. hierarchical structure, node degree distribution, etc.). Inclusiveness combines the strengths of as many generation models as possible in a single generation tool. Interoperability provides interfaces to widely-used simulation applications such as ns and SSF and visualization tools like otter. We call such a tool a universal topology generator.","PeriodicalId":375127,"journal":{"name":"MASCOTS 2001, Proceedings Ninth International Symposium on Modeling, Analysis and Simulation of Computer and Telecommunication Systems","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114646189","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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