Pub Date : 1994-10-02DOI: 10.1109/MILCOM.1994.473901
K. Goethals, M. Mieneclaey
Derives two maximum-likelihood (ML) oriented nondecision-aided (NDA) chip synchronization algorithms for bandlimited direct-sequence spread spectrum (DS/SS) M-PSK signals transmitted over a nonselective fading channel. The authors also investigate their tracking performance in the presence of multi-user interference in a code-division multiple access (CDMA) system where the users have unequal power levels. The performance of the non-channel aided (NCA) algorithm was found to be independent of the fading characteristics, whereas the channel aided (CA) algorithm is influenced by the carrier-to-multipath ratio C/M, but not by the fading bandwidth. For practical E/sub s//N/sub 0/, the NCA algorithm outperforms the CA algorithm, whose performance degrades with decreasing C/M. The performance of both algorithms is better for synchronous than for asynchronous CDMA. For large signal-to-noise ratio, the tracking error variances approach asymptotic values that are inversely proportional to the ratio of the reference user power to the total power of the multi-user interference.<>
{"title":"NDA chip synchronization for bandlimited DS/SS M-PSK signals using CDMA with unequal power levels on nonselective fading channels","authors":"K. Goethals, M. Mieneclaey","doi":"10.1109/MILCOM.1994.473901","DOIUrl":"https://doi.org/10.1109/MILCOM.1994.473901","url":null,"abstract":"Derives two maximum-likelihood (ML) oriented nondecision-aided (NDA) chip synchronization algorithms for bandlimited direct-sequence spread spectrum (DS/SS) M-PSK signals transmitted over a nonselective fading channel. The authors also investigate their tracking performance in the presence of multi-user interference in a code-division multiple access (CDMA) system where the users have unequal power levels. The performance of the non-channel aided (NCA) algorithm was found to be independent of the fading characteristics, whereas the channel aided (CA) algorithm is influenced by the carrier-to-multipath ratio C/M, but not by the fading bandwidth. For practical E/sub s//N/sub 0/, the NCA algorithm outperforms the CA algorithm, whose performance degrades with decreasing C/M. The performance of both algorithms is better for synchronous than for asynchronous CDMA. For large signal-to-noise ratio, the tracking error variances approach asymptotic values that are inversely proportional to the ratio of the reference user power to the total power of the multi-user interference.<<ETX>>","PeriodicalId":337873,"journal":{"name":"Proceedings of MILCOM '94","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1994-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132272443","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 : 1994-10-02DOI: 10.1109/MILCOM.1994.473974
P. Major, F. Bohn
The frequency-allotment function bridges the gap between the national and international frequency allocation tables and the actual frequency assignments for various radio networks. The tables of allocation define the permitted type of operation in various portions of the spectrum; assignments specify the specific frequency in use by a link or net. This paper discusses a scheme for determining the way to define the required frequency complement for a net/network and how the frequencies should be spread out to allow for optimum use of the spectrum by the radio system.<>
{"title":"Frequency allotment capability concept development study","authors":"P. Major, F. Bohn","doi":"10.1109/MILCOM.1994.473974","DOIUrl":"https://doi.org/10.1109/MILCOM.1994.473974","url":null,"abstract":"The frequency-allotment function bridges the gap between the national and international frequency allocation tables and the actual frequency assignments for various radio networks. The tables of allocation define the permitted type of operation in various portions of the spectrum; assignments specify the specific frequency in use by a link or net. This paper discusses a scheme for determining the way to define the required frequency complement for a net/network and how the frequencies should be spread out to allow for optimum use of the spectrum by the radio system.<<ETX>>","PeriodicalId":337873,"journal":{"name":"Proceedings of MILCOM '94","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1994-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123166635","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 : 1994-10-02DOI: 10.1109/MILCOM.1994.473854
L. Paoletti, J. Hyde, A. Hashizume
The Defense Information System Network (DISN) will be the telecommunications infrastructure for all defense information systems in the future. Its architecture consists of three major building blocks: the transport infrastructure segment; a network management segment; and a value-added services segment. The transport infrastructure will be a high-speed broadband integrated services digital network (BISDN) in a hierarchical arrangement. The network management segment will be integrated in a hierarchically-distributed structure of geographically oriented domains. The value-added services segment is yet to be defined. This paper reports on the first focused work to do that. A definition for value-added services (VAS) is established; distinctions are drawn with other network capabilities and characteristics; twenty (20) candidate VASs meeting the definition are examined, especially with respect to military application; and seventeen (17) are recommended for implementation in the Goal DISN, c.2005+.<>
{"title":"Value-added services in the Goal DISN","authors":"L. Paoletti, J. Hyde, A. Hashizume","doi":"10.1109/MILCOM.1994.473854","DOIUrl":"https://doi.org/10.1109/MILCOM.1994.473854","url":null,"abstract":"The Defense Information System Network (DISN) will be the telecommunications infrastructure for all defense information systems in the future. Its architecture consists of three major building blocks: the transport infrastructure segment; a network management segment; and a value-added services segment. The transport infrastructure will be a high-speed broadband integrated services digital network (BISDN) in a hierarchical arrangement. The network management segment will be integrated in a hierarchically-distributed structure of geographically oriented domains. The value-added services segment is yet to be defined. This paper reports on the first focused work to do that. A definition for value-added services (VAS) is established; distinctions are drawn with other network capabilities and characteristics; twenty (20) candidate VASs meeting the definition are examined, especially with respect to military application; and seventeen (17) are recommended for implementation in the Goal DISN, c.2005+.<<ETX>>","PeriodicalId":337873,"journal":{"name":"Proceedings of MILCOM '94","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1994-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134463566","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 : 1994-10-02DOI: 10.1109/MILCOM.1994.473821
K. Giridhar, A. Mathur, J. Shynk
This paper describes a blind adaptive algorithm for the recovery of cochannel data signals in the presence of intersymbol interference. Assuming unknown finite impulse response channel characteristics, the principle of maximum a posteriori symbol detection (MAPSD) is employed to jointly estimate the channels and the transmitted data. In order to reduce the complexity of this joint blind MAPSD algorithm, a cascaded multistage structure is proposed whereby each stage recovers one of the cochannel sources. This suboptimal approach is expected to perform well when the cochannel signals have sufficiently different power levels. Computer simulations for a primary signal and a single interferer illustrate the rapid convergence properties of the algorithm.<>
{"title":"A blind adaptive MAP algorithm for the recovery of cochannel signals","authors":"K. Giridhar, A. Mathur, J. Shynk","doi":"10.1109/MILCOM.1994.473821","DOIUrl":"https://doi.org/10.1109/MILCOM.1994.473821","url":null,"abstract":"This paper describes a blind adaptive algorithm for the recovery of cochannel data signals in the presence of intersymbol interference. Assuming unknown finite impulse response channel characteristics, the principle of maximum a posteriori symbol detection (MAPSD) is employed to jointly estimate the channels and the transmitted data. In order to reduce the complexity of this joint blind MAPSD algorithm, a cascaded multistage structure is proposed whereby each stage recovers one of the cochannel sources. This suboptimal approach is expected to perform well when the cochannel signals have sufficiently different power levels. Computer simulations for a primary signal and a single interferer illustrate the rapid convergence properties of the algorithm.<<ETX>>","PeriodicalId":337873,"journal":{"name":"Proceedings of MILCOM '94","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1994-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131898496","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 : 1994-10-02DOI: 10.1109/MILCOM.1994.473953
L. C. Yun, D. Messerschmitt
The scant bandwidth and high error rates of the wireless channel make joint source-channel coding desirable for optimizing resource usage. To this end, we propose a multiple substream abstraction for source traffic, with delay and loss characteristics negotiated between the application and network on a per-substream basis. This model affords flexibility while maintaining network efficiency by only appropriating more resources (e.g. Bandwidth and error protection) to more important user information. We describe an algorithm for supporting different quality of service (QOS) requirements for different traffic in an interference-limited cellular CDMA environment. The algorithm accepts QOS specifications for different substreams, accommodates them by assigning different power levels to each signal, and can be used to add or drop substream connections dynamically while ensuring that QOS specifications are not violated. Present-day power control schemes are used to combat the near-far effect; while the proposed algorithm also accomplishes this goal, it is in fact more general: via power modulation, it can provision different QOS levels for different substreams.<>
{"title":"Power control for variable QOS on a CDMA channel","authors":"L. C. Yun, D. Messerschmitt","doi":"10.1109/MILCOM.1994.473953","DOIUrl":"https://doi.org/10.1109/MILCOM.1994.473953","url":null,"abstract":"The scant bandwidth and high error rates of the wireless channel make joint source-channel coding desirable for optimizing resource usage. To this end, we propose a multiple substream abstraction for source traffic, with delay and loss characteristics negotiated between the application and network on a per-substream basis. This model affords flexibility while maintaining network efficiency by only appropriating more resources (e.g. Bandwidth and error protection) to more important user information. We describe an algorithm for supporting different quality of service (QOS) requirements for different traffic in an interference-limited cellular CDMA environment. The algorithm accepts QOS specifications for different substreams, accommodates them by assigning different power levels to each signal, and can be used to add or drop substream connections dynamically while ensuring that QOS specifications are not violated. Present-day power control schemes are used to combat the near-far effect; while the proposed algorithm also accomplishes this goal, it is in fact more general: via power modulation, it can provision different QOS levels for different substreams.<<ETX>>","PeriodicalId":337873,"journal":{"name":"Proceedings of MILCOM '94","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1994-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124142145","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 : 1994-10-02DOI: 10.1109/MILCOM.1994.473927
R. Axford, L. Milstein, J. Zeidler
This paper presents an investigation of the misconvergence of the constant modulus algorithm (CMA) for blind equalization in the reception of M-ary PSK or QAM signals that are derived from encoding binary PN sequences. Formulas for the period and probability density-function (p.d.f.) of the pseudo-random M-ary sequence as functions of M and the period of the underlying binary PN sequence are given. The distortion of the probabilistic symmetry of the transmitted constellation is also quantified. Simulation results are presented that illustrate the influence of these signal characteristics on the convergence behavior of CMA.<>
{"title":"On the misconvergence of CMA blind equalizers in the reception of PN sequences","authors":"R. Axford, L. Milstein, J. Zeidler","doi":"10.1109/MILCOM.1994.473927","DOIUrl":"https://doi.org/10.1109/MILCOM.1994.473927","url":null,"abstract":"This paper presents an investigation of the misconvergence of the constant modulus algorithm (CMA) for blind equalization in the reception of M-ary PSK or QAM signals that are derived from encoding binary PN sequences. Formulas for the period and probability density-function (p.d.f.) of the pseudo-random M-ary sequence as functions of M and the period of the underlying binary PN sequence are given. The distortion of the probabilistic symmetry of the transmitted constellation is also quantified. Simulation results are presented that illustrate the influence of these signal characteristics on the convergence behavior of CMA.<<ETX>>","PeriodicalId":337873,"journal":{"name":"Proceedings of MILCOM '94","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1994-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124592236","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 : 1994-10-02DOI: 10.1109/MILCOM.1994.474008
F. Dominique, P. Petrus
Different techniques have been proposed to excise narrow band interference from a direct sequence spread spectrum signal. One such technique is the frequency domain threshold exciser (THE). The THE estimates the spectrum of the received signal and weights the frequency bins appropriately. One disadvantage of this technique is that the power of the signal of interest (SOI) also gets reduced and thus the number of narrow-band interferers that can be excised is limited. This paper proposes a new technique which makes use of the spectral redundancy between the sidebands of the PN-BPSK signal to obtain a better estimate of the spectral energy of the SOI, by replacing corrupted spectral estimates with uncorrupted and correlated estimates. This spectral redundancy exploiting interference suppressor (SPREIS) provides improved performance over the THE with a small increase in the computational complexity. Simulation results are presented.<>
{"title":"Spectral redundancy exploitation in narrow band interference rejection for a PN-BPSK system","authors":"F. Dominique, P. Petrus","doi":"10.1109/MILCOM.1994.474008","DOIUrl":"https://doi.org/10.1109/MILCOM.1994.474008","url":null,"abstract":"Different techniques have been proposed to excise narrow band interference from a direct sequence spread spectrum signal. One such technique is the frequency domain threshold exciser (THE). The THE estimates the spectrum of the received signal and weights the frequency bins appropriately. One disadvantage of this technique is that the power of the signal of interest (SOI) also gets reduced and thus the number of narrow-band interferers that can be excised is limited. This paper proposes a new technique which makes use of the spectral redundancy between the sidebands of the PN-BPSK signal to obtain a better estimate of the spectral energy of the SOI, by replacing corrupted spectral estimates with uncorrupted and correlated estimates. This spectral redundancy exploiting interference suppressor (SPREIS) provides improved performance over the THE with a small increase in the computational complexity. Simulation results are presented.<<ETX>>","PeriodicalId":337873,"journal":{"name":"Proceedings of MILCOM '94","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1994-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122052431","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 : 1994-10-02DOI: 10.1109/MILCOM.1994.473890
J.R. Mostow, M. Harrigan, J. C. Powell, L. Kennedy, W. Barnett
The network planning terminal (NPT) is a newly fielded system designed to provide battlefield spectrum management, network planning and management, communications engineering, and threat modeling for mobile subscriber equipment (MSE). It provides its users with a quick-response planning tool in today's digitized battlefield environment. The first fielding of the NPT was completed in 1994. The NPT program is managed by the Project Manager, Joint Tactical Area Communications Systems. The development team included personnel from the Electromagnetic Compatibility Analysis Center and the US Army Communications-Electronics Command. The NPT enables soldier/users to automatically configure and dynamically reconfigure an MSE network. It allows signal officers to more proficiently perform the required duties, reducing planning from days to hours, and replanning from hours to minutes. No longer must the soldier go through the painstaking, manual process of assigning communication assets or redefining the force structure.<>
{"title":"NPT: the tool for planning MSE networks","authors":"J.R. Mostow, M. Harrigan, J. C. Powell, L. Kennedy, W. Barnett","doi":"10.1109/MILCOM.1994.473890","DOIUrl":"https://doi.org/10.1109/MILCOM.1994.473890","url":null,"abstract":"The network planning terminal (NPT) is a newly fielded system designed to provide battlefield spectrum management, network planning and management, communications engineering, and threat modeling for mobile subscriber equipment (MSE). It provides its users with a quick-response planning tool in today's digitized battlefield environment. The first fielding of the NPT was completed in 1994. The NPT program is managed by the Project Manager, Joint Tactical Area Communications Systems. The development team included personnel from the Electromagnetic Compatibility Analysis Center and the US Army Communications-Electronics Command. The NPT enables soldier/users to automatically configure and dynamically reconfigure an MSE network. It allows signal officers to more proficiently perform the required duties, reducing planning from days to hours, and replanning from hours to minutes. No longer must the soldier go through the painstaking, manual process of assigning communication assets or redefining the force structure.<<ETX>>","PeriodicalId":337873,"journal":{"name":"Proceedings of MILCOM '94","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1994-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122146925","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 : 1994-10-02DOI: 10.1109/MILCOM.1994.473985
G. Earle, R.I. Desourdis
This paper describes an advanced computer-based prediction capability for the design, upgrade, and technical management of HF radio and radar systems. A state-of-the-art HF propagation-prediction algorithm called IONORAY has been developed that employs accurate representations of the ionosphere, the Earth's magnetic field, atmospheric particle density, and particle collisions. The principal prediction and graphical user interface components of the proposed HF forecasting system have been developed. This paper describes the IONPLANNER program concept in general and the IONORAY high-fidelity HF channel model in particular. Analysis modules intended for specific HF applications such as network frequency planning and broadcast coverage are also discussed.<>
{"title":"Advanced modeling of HF radio propagation","authors":"G. Earle, R.I. Desourdis","doi":"10.1109/MILCOM.1994.473985","DOIUrl":"https://doi.org/10.1109/MILCOM.1994.473985","url":null,"abstract":"This paper describes an advanced computer-based prediction capability for the design, upgrade, and technical management of HF radio and radar systems. A state-of-the-art HF propagation-prediction algorithm called IONORAY has been developed that employs accurate representations of the ionosphere, the Earth's magnetic field, atmospheric particle density, and particle collisions. The principal prediction and graphical user interface components of the proposed HF forecasting system have been developed. This paper describes the IONPLANNER program concept in general and the IONORAY high-fidelity HF channel model in particular. Analysis modules intended for specific HF applications such as network frequency planning and broadcast coverage are also discussed.<<ETX>>","PeriodicalId":337873,"journal":{"name":"Proceedings of MILCOM '94","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1994-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123960800","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 : 1994-10-02DOI: 10.1109/MILCOM.1994.473997
M. Martone
Higher than second order statistics is a powerful signal processing tool and a lot of research effort has been made to find new and implementable cumulants based algorithms for system identification and deconvolution of non minimum phase systems for the application in cases of practical interest. In communications problems equalization in the presence of time dispersive channels (usually non minimum phase) is still discussed since traditional autocorrelation (i.e. second order statistics) based methods cannot be used. The authors propose, stemming from the idea of Shalvi and Weinstein (1993), a method for blind channel estimation and symbol detection which seems to be particularly interesting for its fast convergence and conceptual simplicity. The despreading operation is performed jointly with channel distorsion compensation using the algorithm described in Shalvi and Weinstein. The couple correlator/channel is in fact interpreted as a unique FIR (finite impulse response) system whose taps are given by the convolution of the spreading code and the impulse response of the channel. The problem is so reduced to an autoregressive (AR) model to be estimated. Then the receiver is simply constituted by a tapped delay line which is the inverse of the AR model. The channel model is frequency selective slowly fading typical of the L-band satellite channel. The method is faster than traditional methods also over minimum phase channels but there is an increased computational complexity.<>
{"title":"Blind deconvolution in spread spectrum communications over non minimum phase channels","authors":"M. Martone","doi":"10.1109/MILCOM.1994.473997","DOIUrl":"https://doi.org/10.1109/MILCOM.1994.473997","url":null,"abstract":"Higher than second order statistics is a powerful signal processing tool and a lot of research effort has been made to find new and implementable cumulants based algorithms for system identification and deconvolution of non minimum phase systems for the application in cases of practical interest. In communications problems equalization in the presence of time dispersive channels (usually non minimum phase) is still discussed since traditional autocorrelation (i.e. second order statistics) based methods cannot be used. The authors propose, stemming from the idea of Shalvi and Weinstein (1993), a method for blind channel estimation and symbol detection which seems to be particularly interesting for its fast convergence and conceptual simplicity. The despreading operation is performed jointly with channel distorsion compensation using the algorithm described in Shalvi and Weinstein. The couple correlator/channel is in fact interpreted as a unique FIR (finite impulse response) system whose taps are given by the convolution of the spreading code and the impulse response of the channel. The problem is so reduced to an autoregressive (AR) model to be estimated. Then the receiver is simply constituted by a tapped delay line which is the inverse of the AR model. The channel model is frequency selective slowly fading typical of the L-band satellite channel. The method is faster than traditional methods also over minimum phase channels but there is an increased computational complexity.<<ETX>>","PeriodicalId":337873,"journal":{"name":"Proceedings of MILCOM '94","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1994-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131750090","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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