Pub Date : 2009-03-30DOI: 10.1109/SARNOF.2009.4850335
Y. Wen
As a consequence of providing Internet access to many clients over a multi-hop topology network with multiple backhauls, performance is affected by the number of hops that a client is from its backhaul. This spatial bias problem is formulated as a mixed-integer nonlinear programming problem that takes into consideration the end-to-end delay, both in terms of least-hop and load-balanced routing, and in terms of link capacity constraints in mesh structures in this paper. Accordingly, we proposed a sender-based load-balanced routing algorithm that minimizes the maximum end-to-end delay at the network layer, algorithms that achieve load-balanced on each backhaul, each branch of the backhaul, and each flow in multi-hop networks with orthogonal channels. Our experiment results demonstrate that this approach reduced end-to-end delay and outperforms other general routing algorithms.
{"title":"Sender-based resource allocation for multi-hop routing networks","authors":"Y. Wen","doi":"10.1109/SARNOF.2009.4850335","DOIUrl":"https://doi.org/10.1109/SARNOF.2009.4850335","url":null,"abstract":"As a consequence of providing Internet access to many clients over a multi-hop topology network with multiple backhauls, performance is affected by the number of hops that a client is from its backhaul. This spatial bias problem is formulated as a mixed-integer nonlinear programming problem that takes into consideration the end-to-end delay, both in terms of least-hop and load-balanced routing, and in terms of link capacity constraints in mesh structures in this paper. Accordingly, we proposed a sender-based load-balanced routing algorithm that minimizes the maximum end-to-end delay at the network layer, algorithms that achieve load-balanced on each backhaul, each branch of the backhaul, and each flow in multi-hop networks with orthogonal channels. Our experiment results demonstrate that this approach reduced end-to-end delay and outperforms other general routing algorithms.","PeriodicalId":230233,"journal":{"name":"2009 IEEE Sarnoff Symposium","volume":"114 3-4","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120910856","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 : 2009-03-30DOI: 10.1109/SARNOF.2009.4850347
O. Darvishi, B. Abolhassani, H. S. Rad
It is conventionally believed that directional antennas are not as efficient as omnidirectional antennas in MIMO communications since they limit the effective angular spread of the scattering environment. However, it is often neglected that the power gain provided by directional antennas can compensate for the deleterious effect of their limited beamwidth. In this paper, we analyze the efficiency of directional antennas to investigate whether these antennas can improve the capacity of MIMO communication systems versus commonly used omnidirectional antennas. Employing a realistic MIMO channel model, we show that the performance of directional antennas depends on the scattering environment, the signal to noise ratio and the array configuration. Our simulation results suggest that in certain conditions directional antennas can indeed improve the capacity of MIMO systems compared to the capacity achieved by using omnidirectional antennas.
{"title":"On the efficiency of directional antennas in MIMO communication systems","authors":"O. Darvishi, B. Abolhassani, H. S. Rad","doi":"10.1109/SARNOF.2009.4850347","DOIUrl":"https://doi.org/10.1109/SARNOF.2009.4850347","url":null,"abstract":"It is conventionally believed that directional antennas are not as efficient as omnidirectional antennas in MIMO communications since they limit the effective angular spread of the scattering environment. However, it is often neglected that the power gain provided by directional antennas can compensate for the deleterious effect of their limited beamwidth. In this paper, we analyze the efficiency of directional antennas to investigate whether these antennas can improve the capacity of MIMO communication systems versus commonly used omnidirectional antennas. Employing a realistic MIMO channel model, we show that the performance of directional antennas depends on the scattering environment, the signal to noise ratio and the array configuration. Our simulation results suggest that in certain conditions directional antennas can indeed improve the capacity of MIMO systems compared to the capacity achieved by using omnidirectional antennas.","PeriodicalId":230233,"journal":{"name":"2009 IEEE Sarnoff Symposium","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115494299","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 : 2009-03-30DOI: 10.1109/SARNOF.2009.4850367
L. Cai, R. Rojas-Cessa
Peer-to-peer (P2P) networking is used by users with similar interests to exchange, contribute, or obtain files. This network model has been proven popular to exchange music, pictures, or software applications that are saved, and most likely executed at the downloading host. At the expense of this mechanism, worms, viruses, and intruding files find an open front door to the downloading host and giving them place to a very convenient environment for successful proliferation throughout the network. Although virus detection software are currently available, this countermeasure works in a reactive approach and most times isolated manner. In this paper, we consider a trust management scheme to contain the proliferation of viruses in P2P networks. Specifically, we propose a trust management system based on a two-layer approach to bound the proliferation of viruses. The new scheme is called Double-layer Dynamic Trust (DDT) management scheme. Our results show the proposed scheme bounds virus proliferation. With this approach, the number of infected hosts and proliferation rate are limited to small values. We compare our results to other existing approaches.
{"title":"Mitigation of malware proliferation in P2P networks using Double-layer Dynamic Trust (DDT) management scheme","authors":"L. Cai, R. Rojas-Cessa","doi":"10.1109/SARNOF.2009.4850367","DOIUrl":"https://doi.org/10.1109/SARNOF.2009.4850367","url":null,"abstract":"Peer-to-peer (P2P) networking is used by users with similar interests to exchange, contribute, or obtain files. This network model has been proven popular to exchange music, pictures, or software applications that are saved, and most likely executed at the downloading host. At the expense of this mechanism, worms, viruses, and intruding files find an open front door to the downloading host and giving them place to a very convenient environment for successful proliferation throughout the network. Although virus detection software are currently available, this countermeasure works in a reactive approach and most times isolated manner. In this paper, we consider a trust management scheme to contain the proliferation of viruses in P2P networks. Specifically, we propose a trust management system based on a two-layer approach to bound the proliferation of viruses. The new scheme is called Double-layer Dynamic Trust (DDT) management scheme. Our results show the proposed scheme bounds virus proliferation. With this approach, the number of infected hosts and proliferation rate are limited to small values. We compare our results to other existing approaches.","PeriodicalId":230233,"journal":{"name":"2009 IEEE Sarnoff Symposium","volume":"90 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124404681","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 : 2009-03-30DOI: 10.1109/SARNOF.2009.4850292
Sung-Ho Park, Jong-Yeop Lee, Eonpyo Hong, Seungwook Min, D. Har
Merged selected mapping (SLM) scheme is presented for reducing peak-to-average power ratio (PAPR) of an orthogonal frequency division multiplexing (OFDM). The concept of the proposed SLM scheme is based on a combination of advantages of the conventional low complexity SLM schemes by dividing inverse fast Fourier transform (IFFT) into k stage and remaining n-k stage and, then generating additional OFDM signal sequences without performing IFFT to the conventional SLM scheme. This scheme dramatically reduces computational complexity comparing with the conventional SLM schemes under the similar PAPR reduction performance.
{"title":"Merged SLM scheme for PAPR reduction of OFDM system with low complexity","authors":"Sung-Ho Park, Jong-Yeop Lee, Eonpyo Hong, Seungwook Min, D. Har","doi":"10.1109/SARNOF.2009.4850292","DOIUrl":"https://doi.org/10.1109/SARNOF.2009.4850292","url":null,"abstract":"Merged selected mapping (SLM) scheme is presented for reducing peak-to-average power ratio (PAPR) of an orthogonal frequency division multiplexing (OFDM). The concept of the proposed SLM scheme is based on a combination of advantages of the conventional low complexity SLM schemes by dividing inverse fast Fourier transform (IFFT) into k stage and remaining n-k stage and, then generating additional OFDM signal sequences without performing IFFT to the conventional SLM scheme. This scheme dramatically reduces computational complexity comparing with the conventional SLM schemes under the similar PAPR reduction performance.","PeriodicalId":230233,"journal":{"name":"2009 IEEE Sarnoff Symposium","volume":"167 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123435371","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 : 2009-03-30DOI: 10.1109/SARNOF.2009.4850303
M. H. El-Shafey
ESPRIT is known of high resolution in the general problem of signal parameter estimation. It can be applied to a wide variety of problems including accurate detection and estimation of sinusoids in noise, and estimation of signal direction-of-arrival. ESPRIT comprises the solution of two eigenvalue problems. The first is to obtain the eigen-decomposition of the signal correlation matrix. Based on the rotational invariance property of the eigenvectors of the matrix obtained in the first step, the second eigen-problem is formed from different rows of these eigenvectors. In this paper it is shown that the second eigen-problem is a generalized eigen-problem and the accuracy of ESPRIT estimates depends mainly on the condition of this generalized eigen-problem. It is shown that the problem condition depends on the sampling time of the correlation matrix. Numerical results illustrates the impact of the sampling time on the problem condition and consequently on the estimates accuracy.
{"title":"ESPRIT condition in signal parameter estimation","authors":"M. H. El-Shafey","doi":"10.1109/SARNOF.2009.4850303","DOIUrl":"https://doi.org/10.1109/SARNOF.2009.4850303","url":null,"abstract":"ESPRIT is known of high resolution in the general problem of signal parameter estimation. It can be applied to a wide variety of problems including accurate detection and estimation of sinusoids in noise, and estimation of signal direction-of-arrival. ESPRIT comprises the solution of two eigenvalue problems. The first is to obtain the eigen-decomposition of the signal correlation matrix. Based on the rotational invariance property of the eigenvectors of the matrix obtained in the first step, the second eigen-problem is formed from different rows of these eigenvectors. In this paper it is shown that the second eigen-problem is a generalized eigen-problem and the accuracy of ESPRIT estimates depends mainly on the condition of this generalized eigen-problem. It is shown that the problem condition depends on the sampling time of the correlation matrix. Numerical results illustrates the impact of the sampling time on the problem condition and consequently on the estimates accuracy.","PeriodicalId":230233,"journal":{"name":"2009 IEEE Sarnoff Symposium","volume":"51 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128879030","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 : 2009-03-30DOI: 10.1109/SARNOF.2009.4850290
Saeed Daneshmand, H. Aghaeinia, M. Tohidian, Ali Jafarnia Jahromi
This paper discusses blind estimation of periodic long-code (PLC) direct sequence spread spectrum (DSSS) signal. We model a PLC DSSS signal as equivalent to a multiuser short-code DSSS system. This enables us to exploit second-order statistics (SOS) to estimate users' spreading codes up to an inherent ambiguity matrix. Using the structure of the spreading codes of these virtual users and without further restricting assumptions, we will show that the ambiguity matrix can be estimated which would lead us to the extraction of spreading codes. Exploiting similar ideas, we will extend the proposed algorithm to blind estimation of the PLC DSSS signal in multipath environment. Finally, simulations are presented to demonstrate the superior performance of the proposed algorithm.
{"title":"Blind estimation of signal in periodic long-code DSSS communications","authors":"Saeed Daneshmand, H. Aghaeinia, M. Tohidian, Ali Jafarnia Jahromi","doi":"10.1109/SARNOF.2009.4850290","DOIUrl":"https://doi.org/10.1109/SARNOF.2009.4850290","url":null,"abstract":"This paper discusses blind estimation of periodic long-code (PLC) direct sequence spread spectrum (DSSS) signal. We model a PLC DSSS signal as equivalent to a multiuser short-code DSSS system. This enables us to exploit second-order statistics (SOS) to estimate users' spreading codes up to an inherent ambiguity matrix. Using the structure of the spreading codes of these virtual users and without further restricting assumptions, we will show that the ambiguity matrix can be estimated which would lead us to the extraction of spreading codes. Exploiting similar ideas, we will extend the proposed algorithm to blind estimation of the PLC DSSS signal in multipath environment. Finally, simulations are presented to demonstrate the superior performance of the proposed algorithm.","PeriodicalId":230233,"journal":{"name":"2009 IEEE Sarnoff Symposium","volume":"59 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129181390","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 : 2009-03-30DOI: 10.1109/SARNOF.2009.4850289
Jinsuk Baek, Sun Kyong An, P. Fisher, E. Jones
The unbalanced energy consumption among self-powered sensor nodes negatively impacts network lifetime. In order to overcome this limitation, we propose a new cluster header selection and cluster formation scheme. With our scheme, sensor nodes within a cluster autonomously decide in which time frame they will act as a cluster header based on the amount of energy consumption in the current round. In addition, they are conditionally allowed to switch their cluster header depending on signal strength of their current cluster header. Our simulation results show the proposed scheme increases the network lifetime and provides a well-balanced energy consumption pattern among the nodes in a cluster compared to previously proposed schemes.
{"title":"Dynamic cluster header selection with self-incentive for wireless sensor networks","authors":"Jinsuk Baek, Sun Kyong An, P. Fisher, E. Jones","doi":"10.1109/SARNOF.2009.4850289","DOIUrl":"https://doi.org/10.1109/SARNOF.2009.4850289","url":null,"abstract":"The unbalanced energy consumption among self-powered sensor nodes negatively impacts network lifetime. In order to overcome this limitation, we propose a new cluster header selection and cluster formation scheme. With our scheme, sensor nodes within a cluster autonomously decide in which time frame they will act as a cluster header based on the amount of energy consumption in the current round. In addition, they are conditionally allowed to switch their cluster header depending on signal strength of their current cluster header. Our simulation results show the proposed scheme increases the network lifetime and provides a well-balanced energy consumption pattern among the nodes in a cluster compared to previously proposed schemes.","PeriodicalId":230233,"journal":{"name":"2009 IEEE Sarnoff Symposium","volume":"205 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124612529","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 : 2009-03-30DOI: 10.1109/SARNOF.2009.4850354
S. Kassim, N. Eltayeb, J. Chambers
In this work we propose a power control algorithm for a multi-input multi-output orthogonal frequency division multiplexing (MIMO-OFDM) multi-hop collaborative relaying network. Using orthogonal and quasi-orthogonal block codes with three stage processing our algorithm optimally distributes available transmission power based on the architecture and the channel condition at each stage so as to minimize the end-to-end bit error rate (BER) of the entire relay network. For high data rate applications with maximum throughput (as expected for future OFDM systems), we employ a regenerative relaying process, where the relays at each stage decode and through collaborative processing, re-encode the received data before onward transmission to the next stage and then to the destination. We provide simulation results 1 that confirm the performance improvement in the end-to-end bit error rate (BER) of the network using our explicit power allocation algorithm as compared with equal power distribution technique.
{"title":"Resource allocation and block coding within a three-stage collaborative broadband relay network","authors":"S. Kassim, N. Eltayeb, J. Chambers","doi":"10.1109/SARNOF.2009.4850354","DOIUrl":"https://doi.org/10.1109/SARNOF.2009.4850354","url":null,"abstract":"In this work we propose a power control algorithm for a multi-input multi-output orthogonal frequency division multiplexing (MIMO-OFDM) multi-hop collaborative relaying network. Using orthogonal and quasi-orthogonal block codes with three stage processing our algorithm optimally distributes available transmission power based on the architecture and the channel condition at each stage so as to minimize the end-to-end bit error rate (BER) of the entire relay network. For high data rate applications with maximum throughput (as expected for future OFDM systems), we employ a regenerative relaying process, where the relays at each stage decode and through collaborative processing, re-encode the received data before onward transmission to the next stage and then to the destination. We provide simulation results 1 that confirm the performance improvement in the end-to-end bit error rate (BER) of the network using our explicit power allocation algorithm as compared with equal power distribution technique.","PeriodicalId":230233,"journal":{"name":"2009 IEEE Sarnoff Symposium","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121206507","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 : 2009-03-30DOI: 10.1109/SARNOF.2009.4850322
S. Buzzi, H. Poor, A. Zappone
The issue of cross-layer spreading code optimization, widely-linear receiver choice and transmit power control for non-cooperative energy-efficiency maximization in CDMA-based wireless data networks is considered in this paper. While previous work in this area has focused on a simple real signal model, in this paper a baseband complex representation of the data is used, so as to properly take into account the I and Q components of the received signal. For the case in which the received signal is improper, a widely-linear reception structure, processing separately the data and their complex conjugates, is considered. Several non-cooperative games are considered, all of which are shown to admit Nash equilibria. Interestingly, it is found that spreading code optimization coupled with widely-linear filtering permits supporting, with no multiuser interference, a number of users that is twice the processing gain. Numerical results corroborate the validity of the theoretical analysis, and show that widely-linear filtering in the presence of improper data brings remarkable performance improvements with respect to conventional linear receivers.
{"title":"Transmitter optimization, widely-linear detection, and power control for energy-efficient networks: A game-theoretic approach","authors":"S. Buzzi, H. Poor, A. Zappone","doi":"10.1109/SARNOF.2009.4850322","DOIUrl":"https://doi.org/10.1109/SARNOF.2009.4850322","url":null,"abstract":"The issue of cross-layer spreading code optimization, widely-linear receiver choice and transmit power control for non-cooperative energy-efficiency maximization in CDMA-based wireless data networks is considered in this paper. While previous work in this area has focused on a simple real signal model, in this paper a baseband complex representation of the data is used, so as to properly take into account the I and Q components of the received signal. For the case in which the received signal is improper, a widely-linear reception structure, processing separately the data and their complex conjugates, is considered. Several non-cooperative games are considered, all of which are shown to admit Nash equilibria. Interestingly, it is found that spreading code optimization coupled with widely-linear filtering permits supporting, with no multiuser interference, a number of users that is twice the processing gain. Numerical results corroborate the validity of the theoretical analysis, and show that widely-linear filtering in the presence of improper data brings remarkable performance improvements with respect to conventional linear receivers.","PeriodicalId":230233,"journal":{"name":"2009 IEEE Sarnoff Symposium","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130395251","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 : 2009-03-30DOI: 10.1109/SARNOF.2009.4850368
Amey Shevtekar, N. Ansari, R. Karrer
This paper proposes a novel model for instigating the “perfect” DDoS attack. Our model uses a combination of network feedback and coordination of attack rates and protocols to achieve a high level of service deniability and low detectability. We demonstrate via extensive simulations that our attack model achieves a higher impact as compared to the Shrew and the RoQ (Reduction of Quality) attacks while the detectability is low. The model adopts botnets in executing/realizing the perfect storm/attack in a real network. We show that executing the attack is not difficult at all. We then briefly describe failures of recent and most relevant detection approaches in mitigating these attacks. The failures of these schemes demonstrate low detectability of our proposed “perfect storm”.
{"title":"Towards the perfect DDoS aTTACK: The perfect storm","authors":"Amey Shevtekar, N. Ansari, R. Karrer","doi":"10.1109/SARNOF.2009.4850368","DOIUrl":"https://doi.org/10.1109/SARNOF.2009.4850368","url":null,"abstract":"This paper proposes a novel model for instigating the “perfect” DDoS attack. Our model uses a combination of network feedback and coordination of attack rates and protocols to achieve a high level of service deniability and low detectability. We demonstrate via extensive simulations that our attack model achieves a higher impact as compared to the Shrew and the RoQ (Reduction of Quality) attacks while the detectability is low. The model adopts botnets in executing/realizing the perfect storm/attack in a real network. We show that executing the attack is not difficult at all. We then briefly describe failures of recent and most relevant detection approaches in mitigating these attacks. The failures of these schemes demonstrate low detectability of our proposed “perfect storm”.","PeriodicalId":230233,"journal":{"name":"2009 IEEE Sarnoff Symposium","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133539231","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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