Pub Date : 2008-12-08DOI: 10.1109/PIMRC.2008.4699459
Lijuan Geng, F. Lu, Ying-Chang Liang, F. Chin
In this paper, we investigate the advantages of applying random network coding in sensor networks for security purpose. In particular, the problem of constructing a secure multi-path in wireless sensor networks is considered. However, unlike previous wiretapping scenarios, where the threat is posed by external wiretappers, we approach the security from an internal angle: all nodes comply with the communication protocols yet are potential eavesdroppers. By exploiting the advantages provided by random network coding, dense deployment of sensor nodes, and directed diffusion, a novel secure multi-path construction protocol is proposed. Mathematical analysis and computer simulations show that the proposed protocol can attain the maximum achievable transmission rate, at the same time, it prevents intermediate nodes from acquiring any information transmitted from the source to destination.
{"title":"Secure multi-path construction in wireless sensor networks using network coding","authors":"Lijuan Geng, F. Lu, Ying-Chang Liang, F. Chin","doi":"10.1109/PIMRC.2008.4699459","DOIUrl":"https://doi.org/10.1109/PIMRC.2008.4699459","url":null,"abstract":"In this paper, we investigate the advantages of applying random network coding in sensor networks for security purpose. In particular, the problem of constructing a secure multi-path in wireless sensor networks is considered. However, unlike previous wiretapping scenarios, where the threat is posed by external wiretappers, we approach the security from an internal angle: all nodes comply with the communication protocols yet are potential eavesdroppers. By exploiting the advantages provided by random network coding, dense deployment of sensor nodes, and directed diffusion, a novel secure multi-path construction protocol is proposed. Mathematical analysis and computer simulations show that the proposed protocol can attain the maximum achievable transmission rate, at the same time, it prevents intermediate nodes from acquiring any information transmitted from the source to destination.","PeriodicalId":125554,"journal":{"name":"2008 IEEE 19th International Symposium on Personal, Indoor and Mobile Radio Communications","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130928853","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 : 2008-12-08DOI: 10.1109/PIMRC.2008.4699700
Mai Tran, A. Doufexi, A. Nix
Demand for broadband services continues to grow. Conventional high-speed broadband solutions are based on wired-access technologies, such as digital subscriber line (DSL). This type of solution is difficult to deploy in remote areas, and furthermore it lacks support for terminal mobility. Broadband wireless access (BWA) offers a flexible and cost-effective solution to these problems. The WiMAX standard has emerged to harmonize the wide variety of different BWA technologies. The most recent WiMAX standard (802.16e) supports broadband applications to mobile terminals and laptops. This paper analyses the performance of a mobile WiMAX system operating in an urban microcell. As an extension to the basic SISO mode, a number of 2 times 2 MIMO extensions are analysed. Simulated packet error rate and throughput results are presented for each link-speed. The paper highlights the trade-off between peak error-free throughput and robust operation at low SNR.
{"title":"Mobile WiMAX MIMO performance analysis: Downlink and uplink","authors":"Mai Tran, A. Doufexi, A. Nix","doi":"10.1109/PIMRC.2008.4699700","DOIUrl":"https://doi.org/10.1109/PIMRC.2008.4699700","url":null,"abstract":"Demand for broadband services continues to grow. Conventional high-speed broadband solutions are based on wired-access technologies, such as digital subscriber line (DSL). This type of solution is difficult to deploy in remote areas, and furthermore it lacks support for terminal mobility. Broadband wireless access (BWA) offers a flexible and cost-effective solution to these problems. The WiMAX standard has emerged to harmonize the wide variety of different BWA technologies. The most recent WiMAX standard (802.16e) supports broadband applications to mobile terminals and laptops. This paper analyses the performance of a mobile WiMAX system operating in an urban microcell. As an extension to the basic SISO mode, a number of 2 times 2 MIMO extensions are analysed. Simulated packet error rate and throughput results are presented for each link-speed. The paper highlights the trade-off between peak error-free throughput and robust operation at low SNR.","PeriodicalId":125554,"journal":{"name":"2008 IEEE 19th International Symposium on Personal, Indoor and Mobile Radio Communications","volume":"94 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133688052","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 : 2008-12-08DOI: 10.1109/PIMRC.2008.4699786
Abdelouahab Bentrcia, A. Zerguine
In this paper, the recently proposed linear group-wise parallel interference cancellation (LGPIC) detector is identified as a preconditioned block Richardson iterative method. This facilitates considerably the analysis of the convergence behavior of different group-detection schemes. Moreover, by using this approach, the effect of grouping is easily studied as well. Finally, simulation results conducted are in excellent agreement with the theory.
{"title":"A new approach to the analysis of the linear group-wise parallel interference cancellation detector","authors":"Abdelouahab Bentrcia, A. Zerguine","doi":"10.1109/PIMRC.2008.4699786","DOIUrl":"https://doi.org/10.1109/PIMRC.2008.4699786","url":null,"abstract":"In this paper, the recently proposed linear group-wise parallel interference cancellation (LGPIC) detector is identified as a preconditioned block Richardson iterative method. This facilitates considerably the analysis of the convergence behavior of different group-detection schemes. Moreover, by using this approach, the effect of grouping is easily studied as well. Finally, simulation results conducted are in excellent agreement with the theory.","PeriodicalId":125554,"journal":{"name":"2008 IEEE 19th International Symposium on Personal, Indoor and Mobile Radio Communications","volume":"13 6-7","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132287130","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 : 2008-12-08DOI: 10.1109/PIMRC.2008.4699685
Fu-Te Hsu, Hsuan-Jung Su
We explicitly construct space-time codes for a multiple access system composed of K users transmitting simultaneously to the base station in block-fading channels. Each user encodes its own data independently without cooperation between users. Our codes design uses the idea of linear dispersion encoding together with circulant matrices assigned to each user that allow low-complexity linear minimum mean square error (MMSE) decoding when the channel realization is known to the base station. Moreover, the ergodic sum rate of the proposed design is studied and compared with the sum capacity.
{"title":"Linear dispersion space-time codes for multiuser systems with low decoding complexity","authors":"Fu-Te Hsu, Hsuan-Jung Su","doi":"10.1109/PIMRC.2008.4699685","DOIUrl":"https://doi.org/10.1109/PIMRC.2008.4699685","url":null,"abstract":"We explicitly construct space-time codes for a multiple access system composed of K users transmitting simultaneously to the base station in block-fading channels. Each user encodes its own data independently without cooperation between users. Our codes design uses the idea of linear dispersion encoding together with circulant matrices assigned to each user that allow low-complexity linear minimum mean square error (MMSE) decoding when the channel realization is known to the base station. Moreover, the ergodic sum rate of the proposed design is studied and compared with the sum capacity.","PeriodicalId":125554,"journal":{"name":"2008 IEEE 19th International Symposium on Personal, Indoor and Mobile Radio Communications","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132658779","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 : 2008-12-08DOI: 10.1109/PIMRC.2008.4699784
M. Chouayakh, A. Knopp, B. Lankl
We propose a fixed-effort MIMO decoder for frequency selective indoor channels that are characterized by strong line-of-sight (LOS) components. Contrarily to the maximum likelihood (ML) approach, where all possible hypotheses are investigated by the metrics calculation, the proposed MIMO detector performs the search over a reduced set of candidates. This search set contains a reduced but representative set of hypotheses around the linear solution obtained at the first detection stage. The candidates are selected according to pre-computed search probabilities. A decision feedback equalizer (DFE) is applied in order to remove the effect of the inter symbol interferences (ISI) caused by the channel dispersion. The method provides a near ML performance using a fixed computational effort determined by the hardware resources. The proposed detector also shows a significant complexity reduction compared to popular MIMO detectors such as the V-BLAST and the sphere decoder. Moreover, the proposed detector provides a soft output information for each transmitted bit, using the pre-selected candidates from the reduced search set which presents a promising aspect for the coded transmission.
{"title":"Fixed effort MIMO decoders for wireless indoor channels: Theory and practical field trials","authors":"M. Chouayakh, A. Knopp, B. Lankl","doi":"10.1109/PIMRC.2008.4699784","DOIUrl":"https://doi.org/10.1109/PIMRC.2008.4699784","url":null,"abstract":"We propose a fixed-effort MIMO decoder for frequency selective indoor channels that are characterized by strong line-of-sight (LOS) components. Contrarily to the maximum likelihood (ML) approach, where all possible hypotheses are investigated by the metrics calculation, the proposed MIMO detector performs the search over a reduced set of candidates. This search set contains a reduced but representative set of hypotheses around the linear solution obtained at the first detection stage. The candidates are selected according to pre-computed search probabilities. A decision feedback equalizer (DFE) is applied in order to remove the effect of the inter symbol interferences (ISI) caused by the channel dispersion. The method provides a near ML performance using a fixed computational effort determined by the hardware resources. The proposed detector also shows a significant complexity reduction compared to popular MIMO detectors such as the V-BLAST and the sphere decoder. Moreover, the proposed detector provides a soft output information for each transmitted bit, using the pre-selected candidates from the reduced search set which presents a promising aspect for the coded transmission.","PeriodicalId":125554,"journal":{"name":"2008 IEEE 19th International Symposium on Personal, Indoor and Mobile Radio Communications","volume":"211 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132664005","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 : 2008-12-08DOI: 10.1109/PIMRC.2008.4699698
S. Fikar, R. Bogenberger, A. Scholtz
A fast-growing percentage of vehicles are connected by mobile data service technologies. Up to now most of these connections are based on cellular phone standards. The drawbacks of this method to connect the vehicles are: The limited availability of the underlying data networks and the amount of parallel point to point connections needed to cover all users with extensively similar data. A novel approach to overcome these issues is using a ubiquitously available broadcast medium for general downlink data. For this medium the Ku-Band satellite link has been chosen, as it is well developed, ubiquitously available and cheap compared to other satellite broadcast services. The general advantage of broadcasts is that spectrum has to be bought only once, even for thousands of receiving vehicles. Up to now the receiving antenna for the vehicle hindered integration in commercial cars. The problem resulted from a lack of gain, reliability or from inappropriately large manufacturing expenses. This document proposes an array that overcomes these issues and lists the simulation results for a rectangular array of thirty-six elements.
{"title":"Analysis of a novel antenna array for vehicular reception of Ku-Band satellite signals","authors":"S. Fikar, R. Bogenberger, A. Scholtz","doi":"10.1109/PIMRC.2008.4699698","DOIUrl":"https://doi.org/10.1109/PIMRC.2008.4699698","url":null,"abstract":"A fast-growing percentage of vehicles are connected by mobile data service technologies. Up to now most of these connections are based on cellular phone standards. The drawbacks of this method to connect the vehicles are: The limited availability of the underlying data networks and the amount of parallel point to point connections needed to cover all users with extensively similar data. A novel approach to overcome these issues is using a ubiquitously available broadcast medium for general downlink data. For this medium the Ku-Band satellite link has been chosen, as it is well developed, ubiquitously available and cheap compared to other satellite broadcast services. The general advantage of broadcasts is that spectrum has to be bought only once, even for thousands of receiving vehicles. Up to now the receiving antenna for the vehicle hindered integration in commercial cars. The problem resulted from a lack of gain, reliability or from inappropriately large manufacturing expenses. This document proposes an array that overcomes these issues and lists the simulation results for a rectangular array of thirty-six elements.","PeriodicalId":125554,"journal":{"name":"2008 IEEE 19th International Symposium on Personal, Indoor and Mobile Radio Communications","volume":"70 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131458316","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 : 2008-12-08DOI: 10.1109/PIMRC.2008.4699790
Matthias Röckl, K. Frank, T. Strang, M. Kranz, J. Gačnik, J. Schomerus
Current driver assistance systems such as Adaptive Cruise Control (ACC) and in particular future assistance systems such as Collision Warning make high demands on reliability of detection and ranging methods for vehicles within the local vicinity. Autonomous systems such as Radar which are already integrated into a multitude of vehicles meet these requirements to only a limited extent. As an alternative, cooperative systems for detection and ranging will be enabled by future Vehicle-2-Vehicle communication. But cooperative detection and ranging also has drawbacks regarding reliability due to positioning and transmission errors if it is applied in a standalone way. Thus, the solution presented in this paper is a hybrid approach combining autonomous and cooperative methods for detection and ranging within a common architecture. A particle filter is used for state estimation. The results are a higher detection effectiveness and a lower position error compared to using standalone autonomous or cooperative detection and ranging methods.
{"title":"Hybrid fusion approach combining autonomous and cooperative detection and ranging methods for situation-aware driver assistance systems","authors":"Matthias Röckl, K. Frank, T. Strang, M. Kranz, J. Gačnik, J. Schomerus","doi":"10.1109/PIMRC.2008.4699790","DOIUrl":"https://doi.org/10.1109/PIMRC.2008.4699790","url":null,"abstract":"Current driver assistance systems such as Adaptive Cruise Control (ACC) and in particular future assistance systems such as Collision Warning make high demands on reliability of detection and ranging methods for vehicles within the local vicinity. Autonomous systems such as Radar which are already integrated into a multitude of vehicles meet these requirements to only a limited extent. As an alternative, cooperative systems for detection and ranging will be enabled by future Vehicle-2-Vehicle communication. But cooperative detection and ranging also has drawbacks regarding reliability due to positioning and transmission errors if it is applied in a standalone way. Thus, the solution presented in this paper is a hybrid approach combining autonomous and cooperative methods for detection and ranging within a common architecture. A particle filter is used for state estimation. The results are a higher detection effectiveness and a lower position error compared to using standalone autonomous or cooperative detection and ranging methods.","PeriodicalId":125554,"journal":{"name":"2008 IEEE 19th International Symposium on Personal, Indoor and Mobile Radio Communications","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131298992","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 : 2008-12-08DOI: 10.1109/PIMRC.2008.4699655
E. Conte, S. Tomasin, N. Benvenuto
In a cellular system with partial channel state information, i.e. with limited feedback, and multiple antennas, we consider scheduling of downlink transmissions at the base station using beamforming and orthogonal frequency division multiplexing. As the complexity of optimal scheduling for throughput maximization under quality of service constraints grows exponentially with the number of subcarriers, in this paper we propose two low complexity suboptimal techniques. The first is a greedy iterative strategy that at each step selects one user with the aim of maximizing the weighted sum rate (WSR), without the need of recomputing the beamformer. We next propose a pre-selection strategy that removes from the selection process users that do not provide an increase in the WSR, thus speeding the search. Both complexity and performance of the proposed techniques are evaluated and compared with existing solutions in a long-term evolution 3GPP scenario.
{"title":"Scheduling strategies for multiuser MIMO OFDM systems with limited feedback","authors":"E. Conte, S. Tomasin, N. Benvenuto","doi":"10.1109/PIMRC.2008.4699655","DOIUrl":"https://doi.org/10.1109/PIMRC.2008.4699655","url":null,"abstract":"In a cellular system with partial channel state information, i.e. with limited feedback, and multiple antennas, we consider scheduling of downlink transmissions at the base station using beamforming and orthogonal frequency division multiplexing. As the complexity of optimal scheduling for throughput maximization under quality of service constraints grows exponentially with the number of subcarriers, in this paper we propose two low complexity suboptimal techniques. The first is a greedy iterative strategy that at each step selects one user with the aim of maximizing the weighted sum rate (WSR), without the need of recomputing the beamformer. We next propose a pre-selection strategy that removes from the selection process users that do not provide an increase in the WSR, thus speeding the search. Both complexity and performance of the proposed techniques are evaluated and compared with existing solutions in a long-term evolution 3GPP scenario.","PeriodicalId":125554,"journal":{"name":"2008 IEEE 19th International Symposium on Personal, Indoor and Mobile Radio Communications","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127051349","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 : 2008-12-08DOI: 10.1109/PIMRC.2008.4699410
F. Héliot, Xiaoli Chu, R. Hoshyar, R. Tafazolli
The log-normal probability distribution is commonly used in wireless communications to model the shadowing and, more recently, the small-scale fading for indoor ultra-wideband communications. In this paper, an accurate closed-form approximation of the ergodic capacity over log-normal fading channels is derived. This expression can be easily used to evaluate and compare the ergodic capacity of communication systems operating over log-normal fading channels.
{"title":"An accurate closed-form approximation of the ergodic capacity over log-normal fading channels","authors":"F. Héliot, Xiaoli Chu, R. Hoshyar, R. Tafazolli","doi":"10.1109/PIMRC.2008.4699410","DOIUrl":"https://doi.org/10.1109/PIMRC.2008.4699410","url":null,"abstract":"The log-normal probability distribution is commonly used in wireless communications to model the shadowing and, more recently, the small-scale fading for indoor ultra-wideband communications. In this paper, an accurate closed-form approximation of the ergodic capacity over log-normal fading channels is derived. This expression can be easily used to evaluate and compare the ergodic capacity of communication systems operating over log-normal fading channels.","PeriodicalId":125554,"journal":{"name":"2008 IEEE 19th International Symposium on Personal, Indoor and Mobile Radio Communications","volume":"101 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133733210","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 : 2008-12-08DOI: 10.1109/PIMRC.2008.4699912
Janne Riihijärvi, P. Mähönen, M. Wellens, Martin Gordziel
There is need to develop better models and characterization methods for spectrum usage and radio environments of cognitive radios. Currently different theoretical and simulation based approaches towards enabling dynamic spectrum access would greatly benefit from the possibility to generate synthetic data for testing purposes. Such Radio Environment Maps must statistically exhibit the characteristics of realistic environments. Previous and on-going spectrum measurement campaigns are generating a vast amount of such data. In this paper we provide a partial answer to the spectrum modelling problem by showing how one can characterize and model spectrum maps with spatial statistics and random fields. We present the basic mathematical premises for building models and also through examples outline how one can generate useful statistics from real measurement data.
{"title":"Characterization and modelling of spectrum for dynamic spectrum access with spatial statistics and random fields","authors":"Janne Riihijärvi, P. Mähönen, M. Wellens, Martin Gordziel","doi":"10.1109/PIMRC.2008.4699912","DOIUrl":"https://doi.org/10.1109/PIMRC.2008.4699912","url":null,"abstract":"There is need to develop better models and characterization methods for spectrum usage and radio environments of cognitive radios. Currently different theoretical and simulation based approaches towards enabling dynamic spectrum access would greatly benefit from the possibility to generate synthetic data for testing purposes. Such Radio Environment Maps must statistically exhibit the characteristics of realistic environments. Previous and on-going spectrum measurement campaigns are generating a vast amount of such data. In this paper we provide a partial answer to the spectrum modelling problem by showing how one can characterize and model spectrum maps with spatial statistics and random fields. We present the basic mathematical premises for building models and also through examples outline how one can generate useful statistics from real measurement data.","PeriodicalId":125554,"journal":{"name":"2008 IEEE 19th International Symposium on Personal, Indoor and Mobile Radio Communications","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115445223","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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