Pub Date : 2011-03-29DOI: 10.1109/ICCITECHNOL.2011.5762694
S. Ghadrdan, S. Salari, M. Ahmadian
The problem of blind channel estimation in Multiple-Input-Multiple-Output (MIMO) Orthogonal Frequency-Division Multiplexing (OFDM) systems is investigated in this study, assuming that the transmitted symbols are independent and identically distributed. In particular, by utilizing a generalized linear non-redundant precoder, a simple blind channel estimation technique for MIMO-OFDM systems is developed. A novel contribution is that instead of using only one column of the signal covariance matrix, as done in previous works, proposed estimator jointly considers all the information contained in the signal covariance matrix. Comparisons show that the proposed approach outperforms the existing estimators. It is also noticed that the proposed algorithm is much more computationally efficient. Consequently, the proposed method is a promising blind channel estimation candidate for MIMO-OFDM systems.
{"title":"Joint blind channel estimation for MIMO OFDM systems via nonredundant linear precoding","authors":"S. Ghadrdan, S. Salari, M. Ahmadian","doi":"10.1109/ICCITECHNOL.2011.5762694","DOIUrl":"https://doi.org/10.1109/ICCITECHNOL.2011.5762694","url":null,"abstract":"The problem of blind channel estimation in Multiple-Input-Multiple-Output (MIMO) Orthogonal Frequency-Division Multiplexing (OFDM) systems is investigated in this study, assuming that the transmitted symbols are independent and identically distributed. In particular, by utilizing a generalized linear non-redundant precoder, a simple blind channel estimation technique for MIMO-OFDM systems is developed. A novel contribution is that instead of using only one column of the signal covariance matrix, as done in previous works, proposed estimator jointly considers all the information contained in the signal covariance matrix. Comparisons show that the proposed approach outperforms the existing estimators. It is also noticed that the proposed algorithm is much more computationally efficient. Consequently, the proposed method is a promising blind channel estimation candidate for MIMO-OFDM systems.","PeriodicalId":211631,"journal":{"name":"2011 International Conference on Communications and Information Technology (ICCIT)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2011-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125860625","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 : 2011-03-29DOI: 10.1109/ICCITECHNOL.2011.5762657
H. Mcheick, Y. Qi, H. Safa, M. Karam
Software connectors play an important role in distributed system. In recent years, software developers have been facing more challenges of connectors which are used to connect distributed components. Design of connectors in an existing system encounters many issues such as dependency of components, how can we choose the connectors between them based on scenario quality, match these connectors with design pattern, and implement them. In this paper, we propose a software model and use a developing tool to design connectors between components in distributed system. A case study is done to maintain high level of independency between components and to illustrate this independency. The solution makes use of Aspect-Oriented Programming (AOP) to communicate the components.
{"title":"Design and implement connectors in distributed system","authors":"H. Mcheick, Y. Qi, H. Safa, M. Karam","doi":"10.1109/ICCITECHNOL.2011.5762657","DOIUrl":"https://doi.org/10.1109/ICCITECHNOL.2011.5762657","url":null,"abstract":"Software connectors play an important role in distributed system. In recent years, software developers have been facing more challenges of connectors which are used to connect distributed components. Design of connectors in an existing system encounters many issues such as dependency of components, how can we choose the connectors between them based on scenario quality, match these connectors with design pattern, and implement them. In this paper, we propose a software model and use a developing tool to design connectors between components in distributed system. A case study is done to maintain high level of independency between components and to illustrate this independency. The solution makes use of Aspect-Oriented Programming (AOP) to communicate the components.","PeriodicalId":211631,"journal":{"name":"2011 International Conference on Communications and Information Technology (ICCIT)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2011-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123772660","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 : 2011-03-29DOI: 10.1109/ICCITECHNOL.2011.5762695
N. Suraweera, K. Wavegedara
In highly spatially correlated channels the diversity gain achieved by space-frequency (SF) coding is significantly low. Nevertheless, when full or partial channel state information is available at the transmitter, improved performance can be obtained by combining transmit beamforming with SF coding. In this paper we propose two novel transmit beamforming techniques based on the minimum pair-wise error probability (PEP) criterion for SF-coded MIMO-OFDM systems in frequency-selective Ricean fading channels. The proposed beamforming techniques (referred to as Technique 1 and Technique 2) require only the channel mean and spatial correlation statistics. Technique 1 optimally distributes the total transmit power among all the eigenmodes of the channel, whereas Technique 2 allocates the total transmit power only to the strongest eigenmodes of the channel. The simulation results demonstrate that Technique 1 and 2 offers considerable performance improvements over a system using only SF coding in low and highly spatially correlated channels, respectively. When compared with Technique 1, Technique 2 is more appealing due to the facts that it has less computational complexity, and that it offers better performance in highly correlated channels for all values of the Ricean-K factor.
{"title":"Transmit beamforming techniques for space-frequency coded MIMO-OFDM systems in a correlated Ricean fading channel","authors":"N. Suraweera, K. Wavegedara","doi":"10.1109/ICCITECHNOL.2011.5762695","DOIUrl":"https://doi.org/10.1109/ICCITECHNOL.2011.5762695","url":null,"abstract":"In highly spatially correlated channels the diversity gain achieved by space-frequency (SF) coding is significantly low. Nevertheless, when full or partial channel state information is available at the transmitter, improved performance can be obtained by combining transmit beamforming with SF coding. In this paper we propose two novel transmit beamforming techniques based on the minimum pair-wise error probability (PEP) criterion for SF-coded MIMO-OFDM systems in frequency-selective Ricean fading channels. The proposed beamforming techniques (referred to as Technique 1 and Technique 2) require only the channel mean and spatial correlation statistics. Technique 1 optimally distributes the total transmit power among all the eigenmodes of the channel, whereas Technique 2 allocates the total transmit power only to the strongest eigenmodes of the channel. The simulation results demonstrate that Technique 1 and 2 offers considerable performance improvements over a system using only SF coding in low and highly spatially correlated channels, respectively. When compared with Technique 1, Technique 2 is more appealing due to the facts that it has less computational complexity, and that it offers better performance in highly correlated channels for all values of the Ricean-K factor.","PeriodicalId":211631,"journal":{"name":"2011 International Conference on Communications and Information Technology (ICCIT)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2011-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127728484","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 : 2011-03-29DOI: 10.1109/ICCITECHNOL.2011.5762691
O. Shagdar, Kengo Sakai, H. Yomo, Akio Hasegawa, Tatsuo Shibata, R. Miura, S. Obana
Although IEEE 802.11e standard is approved for better QoS support, the bandwidth allocation to individual access categories (ACs) can unpredictably vary, preventing efficient QoS provisioning. In this paper, we propose a scheme that jointly maximizes channel capacity and provides network-wide service differentiation to provide fine grained proportional bandwidth allocation to ACs without depending on the number of nodes and channel condition. The proposed scheme is analytically grounded and extensively investigated through computer simulations.
{"title":"Throughput maximization and network-wide service differentiation for IEEE802.11e WLAN","authors":"O. Shagdar, Kengo Sakai, H. Yomo, Akio Hasegawa, Tatsuo Shibata, R. Miura, S. Obana","doi":"10.1109/ICCITECHNOL.2011.5762691","DOIUrl":"https://doi.org/10.1109/ICCITECHNOL.2011.5762691","url":null,"abstract":"Although IEEE 802.11e standard is approved for better QoS support, the bandwidth allocation to individual access categories (ACs) can unpredictably vary, preventing efficient QoS provisioning. In this paper, we propose a scheme that jointly maximizes channel capacity and provides network-wide service differentiation to provide fine grained proportional bandwidth allocation to ACs without depending on the number of nodes and channel condition. The proposed scheme is analytically grounded and extensively investigated through computer simulations.","PeriodicalId":211631,"journal":{"name":"2011 International Conference on Communications and Information Technology (ICCIT)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2011-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128440426","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 : 2011-03-29DOI: 10.1109/ICCITECHNOL.2011.5762678
M. Alayesh, N. Ghani
In cognitive radio networks, power control is considered to be a very important concern where secondary users, which are equipped with cognitive radios, try to access the unused spectrum of licensed primary users in an opportunistic way. Cognitive radios enable the secondary users to sense the presence of primary users and tune the channel (spectrum band) which is not in use at any time for its use. However, the interactions between secondary users are the only parameters which have been considered in most of the existing studies in this space, and the impact of primary user behaviors has been ignored. Hence, a novel realistic primary-secondary game-theoretic scheme is proposed in this study which rewards primary user for sharing its spectrum and allows secondary users to achieve energy-efficient transmissions. In general, the additive white Gaussian noise channel model is considered to be poor to describe the transmission channel and one must resort to more precise and realistic models such as fading channels. The proposed work here extends the fast flat fading models investigated in [1] and [2] to consider slow flat fading channels, where Rayleigh slow flat fading channel is analyzed and a closed-form expression is derived for the average utility functions. The existence and uniqueness of Nash equilibrium are also shown. Finally, detailed simulation results are presented to verify the performance of the scheme under realistic channel conditions compared to AWGN channel model.
{"title":"Cognitive radios power control game under Rayleigh slow fading channel","authors":"M. Alayesh, N. Ghani","doi":"10.1109/ICCITECHNOL.2011.5762678","DOIUrl":"https://doi.org/10.1109/ICCITECHNOL.2011.5762678","url":null,"abstract":"In cognitive radio networks, power control is considered to be a very important concern where secondary users, which are equipped with cognitive radios, try to access the unused spectrum of licensed primary users in an opportunistic way. Cognitive radios enable the secondary users to sense the presence of primary users and tune the channel (spectrum band) which is not in use at any time for its use. However, the interactions between secondary users are the only parameters which have been considered in most of the existing studies in this space, and the impact of primary user behaviors has been ignored. Hence, a novel realistic primary-secondary game-theoretic scheme is proposed in this study which rewards primary user for sharing its spectrum and allows secondary users to achieve energy-efficient transmissions. In general, the additive white Gaussian noise channel model is considered to be poor to describe the transmission channel and one must resort to more precise and realistic models such as fading channels. The proposed work here extends the fast flat fading models investigated in [1] and [2] to consider slow flat fading channels, where Rayleigh slow flat fading channel is analyzed and a closed-form expression is derived for the average utility functions. The existence and uniqueness of Nash equilibrium are also shown. Finally, detailed simulation results are presented to verify the performance of the scheme under realistic channel conditions compared to AWGN channel model.","PeriodicalId":211631,"journal":{"name":"2011 International Conference on Communications and Information Technology (ICCIT)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2011-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116831117","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 : 2011-03-29DOI: 10.1109/ICCITECHNOL.2011.5762658
A. Eleyan, Liping Zhao
This paper proposes a quality matchmaker which introduces four algorithms or filters: interface matching, quality criteria matchmaking, quality value constraints matching, and mathematical matchmaking. These four algorithms use the quality matchmaker sub-components to implement their roles. The quality matchmaker has three sub-components which are: interface matchmaking, quality criteria matchmaking and mathematical matchmaking. A quality matchmaking process (QMP) is introduced to demonstrate the above four algorithms and to select the best Web service. The mathematical matchmaking algorithm is the most important step that uses a mathematical model in order to select the best candidates Web service based on requester's quality requirements and preferences. Two techniques are used in a mathematical model: Analytical Hierarchy Process (AHP) and Euclidean distance.
{"title":"Service selection using quality matchmaking","authors":"A. Eleyan, Liping Zhao","doi":"10.1109/ICCITECHNOL.2011.5762658","DOIUrl":"https://doi.org/10.1109/ICCITECHNOL.2011.5762658","url":null,"abstract":"This paper proposes a quality matchmaker which introduces four algorithms or filters: interface matching, quality criteria matchmaking, quality value constraints matching, and mathematical matchmaking. These four algorithms use the quality matchmaker sub-components to implement their roles. The quality matchmaker has three sub-components which are: interface matchmaking, quality criteria matchmaking and mathematical matchmaking. A quality matchmaking process (QMP) is introduced to demonstrate the above four algorithms and to select the best Web service. The mathematical matchmaking algorithm is the most important step that uses a mathematical model in order to select the best candidates Web service based on requester's quality requirements and preferences. Two techniques are used in a mathematical model: Analytical Hierarchy Process (AHP) and Euclidean distance.","PeriodicalId":211631,"journal":{"name":"2011 International Conference on Communications and Information Technology (ICCIT)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2011-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115520097","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 : 2011-03-29DOI: 10.1109/ICCITECHNOL.2011.5762688
A. D. Hossain, H. Erkan, A. Shami
This work analyzes the downstream impediments of centralized local access networks with LAN capability and proposes an efficient downstream scheme over a distributed upstream control plane, where OLT is relieved from the burden of upstream control function and inter-ONU communication.
{"title":"Downstream bandwidth allocation scheme in local access over a distributed control plane","authors":"A. D. Hossain, H. Erkan, A. Shami","doi":"10.1109/ICCITECHNOL.2011.5762688","DOIUrl":"https://doi.org/10.1109/ICCITECHNOL.2011.5762688","url":null,"abstract":"This work analyzes the downstream impediments of centralized local access networks with LAN capability and proposes an efficient downstream scheme over a distributed upstream control plane, where OLT is relieved from the burden of upstream control function and inter-ONU communication.","PeriodicalId":211631,"journal":{"name":"2011 International Conference on Communications and Information Technology (ICCIT)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2011-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132230216","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 : 2011-03-29DOI: 10.1109/ICCITECHNOL.2011.5762667
M. I. Cheema, S. Khan
In this paper, two estimators are proposed for calculating fine timing and channel impulse response (CIR) of a CD-OFDM based communication system. The proposed low complexity algorithms are designed to operate with asynchronous nodes having independent timing and carrier frequency offsets. These algorithms fully exploit the specially designed structure of time domain preamble used for cooperative communications. For the sake of reducing complexity, both estimators use the correlation results of the same preamble. Moreover, CIR is estimated in time domain thus making multiple FFT operations redundant. Further, fine timing estimator is based on a simple but robust idea of first channel tap identification in cooperative communications scenario. The performance of these algorithms is evaluated in rayleigh fading environment using monte carlo simulations and performance is found better than other comparable algorithms.
{"title":"A low complexity fine timing offset and channel estimation algorithm for cooperative diversity OFDM system","authors":"M. I. Cheema, S. Khan","doi":"10.1109/ICCITECHNOL.2011.5762667","DOIUrl":"https://doi.org/10.1109/ICCITECHNOL.2011.5762667","url":null,"abstract":"In this paper, two estimators are proposed for calculating fine timing and channel impulse response (CIR) of a CD-OFDM based communication system. The proposed low complexity algorithms are designed to operate with asynchronous nodes having independent timing and carrier frequency offsets. These algorithms fully exploit the specially designed structure of time domain preamble used for cooperative communications. For the sake of reducing complexity, both estimators use the correlation results of the same preamble. Moreover, CIR is estimated in time domain thus making multiple FFT operations redundant. Further, fine timing estimator is based on a simple but robust idea of first channel tap identification in cooperative communications scenario. The performance of these algorithms is evaluated in rayleigh fading environment using monte carlo simulations and performance is found better than other comparable algorithms.","PeriodicalId":211631,"journal":{"name":"2011 International Conference on Communications and Information Technology (ICCIT)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2011-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114398754","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 : 2011-03-29DOI: 10.1109/ICCITECHNOL.2011.5762681
M. Merabti, Michael Kennedy, William Hurst
Over recent years the depth to which we have grown to rely on networked computer systems as part of the critical national infrastructure has become ever more apparent. Concern over difficulties caused by accidental failures has led to a realisation of the potential for damage that could be caused by targeted attacks and cyber warfare. Current approaches to addressing these problems have tended to focus on traditional security measures, and have not mobilised the full breadth of capabilities provided by digital technologies. In this paper we will explore some of the challenges associated with these developments. We also consider potential solutions, and in particular how a combination of networking, security, advanced gaming, visualisation techniques, and the increasingly blurred boundary between physical and digital entities, can be used to improve protection of critical infrastructure systems.
{"title":"Critical infrastructure protection: A 21st century challenge","authors":"M. Merabti, Michael Kennedy, William Hurst","doi":"10.1109/ICCITECHNOL.2011.5762681","DOIUrl":"https://doi.org/10.1109/ICCITECHNOL.2011.5762681","url":null,"abstract":"Over recent years the depth to which we have grown to rely on networked computer systems as part of the critical national infrastructure has become ever more apparent. Concern over difficulties caused by accidental failures has led to a realisation of the potential for damage that could be caused by targeted attacks and cyber warfare. Current approaches to addressing these problems have tended to focus on traditional security measures, and have not mobilised the full breadth of capabilities provided by digital technologies. In this paper we will explore some of the challenges associated with these developments. We also consider potential solutions, and in particular how a combination of networking, security, advanced gaming, visualisation techniques, and the increasingly blurred boundary between physical and digital entities, can be used to improve protection of critical infrastructure systems.","PeriodicalId":211631,"journal":{"name":"2011 International Conference on Communications and Information Technology (ICCIT)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2011-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114555907","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 : 2011-03-29DOI: 10.1109/ICCITECHNOL.2011.5762703
M. Alkhawlani, K. Alsalem, A. Hussein
In the next generation heterogeneous wireless networks, a user with a multi-interface terminal may have network access from different service providers using various technologies. Vertical Handover (VHO) is the capability to switch on-going connections from one Radio Access Network (RAN) to another. This switching is based on the discovered accesses, QoS constraints, operator policies, user preferences and available system capacity and utilization. Optimizing the VHO process is an important issue of research, which leads to reduction of network signalling and mobile device power loss and on the other hand improves network quality of service (QoS) and grade of service (GoS). In this paper, a decision support system is developed to address the VHO problem. This system combines fuzzy logic and TOPSIS, a MCDM algorithm, to the problem of VHO. This combination decreases the influence of the dissimilar, imprecise, and contradictory measurements for the VHO criteria coming from different sources. A performance analysis is done and results are compared with traditional algorithms for VHO. These results demonstrate a significant improvement with our developed algorithm.
{"title":"Multi-criteria Vertical Handover by TOPSIS and fuzzy logic","authors":"M. Alkhawlani, K. Alsalem, A. Hussein","doi":"10.1109/ICCITECHNOL.2011.5762703","DOIUrl":"https://doi.org/10.1109/ICCITECHNOL.2011.5762703","url":null,"abstract":"In the next generation heterogeneous wireless networks, a user with a multi-interface terminal may have network access from different service providers using various technologies. Vertical Handover (VHO) is the capability to switch on-going connections from one Radio Access Network (RAN) to another. This switching is based on the discovered accesses, QoS constraints, operator policies, user preferences and available system capacity and utilization. Optimizing the VHO process is an important issue of research, which leads to reduction of network signalling and mobile device power loss and on the other hand improves network quality of service (QoS) and grade of service (GoS). In this paper, a decision support system is developed to address the VHO problem. This system combines fuzzy logic and TOPSIS, a MCDM algorithm, to the problem of VHO. This combination decreases the influence of the dissimilar, imprecise, and contradictory measurements for the VHO criteria coming from different sources. A performance analysis is done and results are compared with traditional algorithms for VHO. These results demonstrate a significant improvement with our developed algorithm.","PeriodicalId":211631,"journal":{"name":"2011 International Conference on Communications and Information Technology (ICCIT)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2011-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133500485","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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