Pub Date : 1993-10-11DOI: 10.1109/MILCOM.1993.408635
W. Ralston, J. Weitzen
The authors examine the application of direct-sequence random code-division multiple-access to large meteor-burst network. Narrowband meteor burst networks have succesfully supported networks of up to a few hundred nodes on a single channel by relying on the natural spatial multiplexing of the meteor channel to support communications. For large high-density meteor-burst networks, however, this spatial multiplexing can fail to provide adequate diversity to avoid collisions. A spread spectrum system can accommodate many thousands of nodes, and through a combination of channel propagation delay and the introduction of random time offsets operate with a single common spreading code. Throughput and waiting time predictions for such a system are illustrated as a function of the number of simultaneous users, network size, bandwidth, and signal level differences between users. It is shown that a spread spectrum system can accommodate very large networks and provide several orders of magnitude improvement over a conventional single channel system.<>
{"title":"Direct sequence CDMA for large meteor burst networks","authors":"W. Ralston, J. Weitzen","doi":"10.1109/MILCOM.1993.408635","DOIUrl":"https://doi.org/10.1109/MILCOM.1993.408635","url":null,"abstract":"The authors examine the application of direct-sequence random code-division multiple-access to large meteor-burst network. Narrowband meteor burst networks have succesfully supported networks of up to a few hundred nodes on a single channel by relying on the natural spatial multiplexing of the meteor channel to support communications. For large high-density meteor-burst networks, however, this spatial multiplexing can fail to provide adequate diversity to avoid collisions. A spread spectrum system can accommodate many thousands of nodes, and through a combination of channel propagation delay and the introduction of random time offsets operate with a single common spreading code. Throughput and waiting time predictions for such a system are illustrated as a function of the number of simultaneous users, network size, bandwidth, and signal level differences between users. It is shown that a spread spectrum system can accommodate very large networks and provide several orders of magnitude improvement over a conventional single channel system.<<ETX>>","PeriodicalId":323612,"journal":{"name":"Proceedings of MILCOM '93 - IEEE Military Communications Conference","volume":"192 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1993-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115727018","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 : 1993-10-11DOI: 10.1109/MILCOM.1993.408601
R. Mouldin, M. Rafter, P. Young
The current Post Cold War land combat doctrine is geared toward regional conflicts; is focused on power projection; and emphasizes mobility, sanctuary operations, smaller CPs, and C2OTM. Sustaining the intuitive commander and providing the ability to evaluate alternatives, issue orders, and execute within the enemy's decision cycle and beyond his contact range, requires the ability to digitize the battlefield and to own the spectrum. The authors describe a wireless radio based approach which provides for a robust, survivable, very low probability of detection, wide bandwidth LAN interconnect supporting C2OTM for echelons of Brigade and above. They discuss the design and system performance characteristics of an NDI approach based upon a single ASIC chip, fully digital, wideband, spread spectrum demodulator with typical performance parameters of: direct sequence PN spread at rates to 325 M chips/s; real time programmable variable data rates to 325 Mbps; spread spectrum processing gains up to 60 dB; continuous and burst (TDD/TDMA) operation; multiple waveform compatibility (BPSK, QPSK, OQPSK, Bi-BPSK, MSK, CCSK); combined with BER performance within 0.5 dB of theoretical.<>
{"title":"Low probability of detection tactical wireless LAN supporting command and control on the move","authors":"R. Mouldin, M. Rafter, P. Young","doi":"10.1109/MILCOM.1993.408601","DOIUrl":"https://doi.org/10.1109/MILCOM.1993.408601","url":null,"abstract":"The current Post Cold War land combat doctrine is geared toward regional conflicts; is focused on power projection; and emphasizes mobility, sanctuary operations, smaller CPs, and C2OTM. Sustaining the intuitive commander and providing the ability to evaluate alternatives, issue orders, and execute within the enemy's decision cycle and beyond his contact range, requires the ability to digitize the battlefield and to own the spectrum. The authors describe a wireless radio based approach which provides for a robust, survivable, very low probability of detection, wide bandwidth LAN interconnect supporting C2OTM for echelons of Brigade and above. They discuss the design and system performance characteristics of an NDI approach based upon a single ASIC chip, fully digital, wideband, spread spectrum demodulator with typical performance parameters of: direct sequence PN spread at rates to 325 M chips/s; real time programmable variable data rates to 325 Mbps; spread spectrum processing gains up to 60 dB; continuous and burst (TDD/TDMA) operation; multiple waveform compatibility (BPSK, QPSK, OQPSK, Bi-BPSK, MSK, CCSK); combined with BER performance within 0.5 dB of theoretical.<<ETX>>","PeriodicalId":323612,"journal":{"name":"Proceedings of MILCOM '93 - IEEE Military Communications Conference","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1993-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123744963","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 : 1993-10-11DOI: 10.1109/MILCOM.1993.408535
Y.A. Barsoum, D.H.L. Yin, T. Lee
Intentional and nonintentional interference causes performance degradation to satellite communication links. The authors examine the detection and identification of interference through the use of digital signal processing and the neural network. They determine the sensitivity of the communication waveform to the anomalies, develop a simulation to evaluate the detection and identification performance of the digital signal processing, and develop a neural network to automate the detection process. The authors describe the simulation model, present the results of the sensitivity analysis, and present the detection performance of the digital processing and neural network. Results indicate that the averaged periodogram is capable of identifying tone jammers and adjacent channel interference (ACI) that degrade the bit error rate (BER) performance; and although the detection performance of the neural network developed is promising, it is not at a stage to detect interference with high accuracy.<>
{"title":"Detection of anomalies on satellite channels using signal processing and neural network","authors":"Y.A. Barsoum, D.H.L. Yin, T. Lee","doi":"10.1109/MILCOM.1993.408535","DOIUrl":"https://doi.org/10.1109/MILCOM.1993.408535","url":null,"abstract":"Intentional and nonintentional interference causes performance degradation to satellite communication links. The authors examine the detection and identification of interference through the use of digital signal processing and the neural network. They determine the sensitivity of the communication waveform to the anomalies, develop a simulation to evaluate the detection and identification performance of the digital signal processing, and develop a neural network to automate the detection process. The authors describe the simulation model, present the results of the sensitivity analysis, and present the detection performance of the digital processing and neural network. Results indicate that the averaged periodogram is capable of identifying tone jammers and adjacent channel interference (ACI) that degrade the bit error rate (BER) performance; and although the detection performance of the neural network developed is promising, it is not at a stage to detect interference with high accuracy.<<ETX>>","PeriodicalId":323612,"journal":{"name":"Proceedings of MILCOM '93 - IEEE Military Communications Conference","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1993-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125330525","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 : 1993-10-11DOI: 10.1109/MILCOM.1993.408677
C.-J. Wang
The Walker (1984) delta satellite constellation appears to be practical to serve as a low Earth orbit satellite network to provide world-wide networking. The structural properties of the Walker delta network, including diameter, mean message traversal, traffic density, and network saturation conditions are investigated and presented. Three different traffic patterns are used in this study. It has been found that for a fixed number of satellites, the Walker delta network can provide minimum mean message traversal, minimum traffic density and maximum traffic injection rate provided that the number of orbital planes is equal to the number of satellites in each orbital plane. Regarding the injection of messages from ground stations to the satellite network, the network with a smaller size can accept more messages than a network with a larger size before the network saturates. Furthermore, an adaptive routing algorithm, which always routes the message to its destination through one of several available minimal paths, is also presented.<>
{"title":"Structural properties of a low Earth orbit satellite constellation - the Walker delta network","authors":"C.-J. Wang","doi":"10.1109/MILCOM.1993.408677","DOIUrl":"https://doi.org/10.1109/MILCOM.1993.408677","url":null,"abstract":"The Walker (1984) delta satellite constellation appears to be practical to serve as a low Earth orbit satellite network to provide world-wide networking. The structural properties of the Walker delta network, including diameter, mean message traversal, traffic density, and network saturation conditions are investigated and presented. Three different traffic patterns are used in this study. It has been found that for a fixed number of satellites, the Walker delta network can provide minimum mean message traversal, minimum traffic density and maximum traffic injection rate provided that the number of orbital planes is equal to the number of satellites in each orbital plane. Regarding the injection of messages from ground stations to the satellite network, the network with a smaller size can accept more messages than a network with a larger size before the network saturates. Furthermore, an adaptive routing algorithm, which always routes the message to its destination through one of several available minimal paths, is also presented.<<ETX>>","PeriodicalId":323612,"journal":{"name":"Proceedings of MILCOM '93 - IEEE Military Communications Conference","volume":"90 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1993-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115559191","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 : 1993-10-11DOI: 10.1109/MILCOM.1993.408604
K.H.A. Karkkainen
Two classes of nonlinear feedforward logic (NLFFL) pseudonoise (PN) sequences based on AND and majority logic (ML) gates are compared. Suggestions are made for sequence design. Correlation and direct-sequence (DS) spread-spectrum multiple-access (SSMA) properties of properly designed NLFFL sequences are found to be comparable with the properties of well-known linear PN sequences. It is determined that sequence design employing ML gates with an odd number of inputs is easier compared with the design with AND gates, especially when the number of gate inputs is large The severe nonbalance problem at the output of an AND or equivalent nonlinear gate can be avoided. ML-NLFFL type sequences are less vulnerable to correlation attack and jamming by the basic m-sequence. Instead, they possess smaller linear complexity values compared with AND-NLFFL sequences.<>
{"title":"Correlation, spread-spectrum multiple-access and linear complexity properties of nonlinear feedforward logic (NLFFL) pseudonoise sequences","authors":"K.H.A. Karkkainen","doi":"10.1109/MILCOM.1993.408604","DOIUrl":"https://doi.org/10.1109/MILCOM.1993.408604","url":null,"abstract":"Two classes of nonlinear feedforward logic (NLFFL) pseudonoise (PN) sequences based on AND and majority logic (ML) gates are compared. Suggestions are made for sequence design. Correlation and direct-sequence (DS) spread-spectrum multiple-access (SSMA) properties of properly designed NLFFL sequences are found to be comparable with the properties of well-known linear PN sequences. It is determined that sequence design employing ML gates with an odd number of inputs is easier compared with the design with AND gates, especially when the number of gate inputs is large The severe nonbalance problem at the output of an AND or equivalent nonlinear gate can be avoided. ML-NLFFL type sequences are less vulnerable to correlation attack and jamming by the basic m-sequence. Instead, they possess smaller linear complexity values compared with AND-NLFFL sequences.<<ETX>>","PeriodicalId":323612,"journal":{"name":"Proceedings of MILCOM '93 - IEEE Military Communications Conference","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1993-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116051428","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 : 1993-10-11DOI: 10.1109/MILCOM.1993.408707
J. Wang
The tracking performance of 2nd-order delay-locked loops (DLL) with high gain for PN code chip synchronization is theoretically analyzed and evaluated by means of a Fokker-Planck equation. The results show that the steady state probability density function of normalized delay error of 2nd-order DLL with high gain is similar to that of a lst-order DLL; for the same mean-squared tracking jitter, the former has 10 log (1 + 1/4/spl xi//sup 2/) (db) less signal-to-noise ratio than the latter. Also, some experimental results are presented. Though only DLL is analyzed, the analytical method is valid for other kinds of tracking loops.<>
{"title":"A second-order delay-locked loop of a spread spectrum receiver","authors":"J. Wang","doi":"10.1109/MILCOM.1993.408707","DOIUrl":"https://doi.org/10.1109/MILCOM.1993.408707","url":null,"abstract":"The tracking performance of 2nd-order delay-locked loops (DLL) with high gain for PN code chip synchronization is theoretically analyzed and evaluated by means of a Fokker-Planck equation. The results show that the steady state probability density function of normalized delay error of 2nd-order DLL with high gain is similar to that of a lst-order DLL; for the same mean-squared tracking jitter, the former has 10 log (1 + 1/4/spl xi//sup 2/) (db) less signal-to-noise ratio than the latter. Also, some experimental results are presented. Though only DLL is analyzed, the analytical method is valid for other kinds of tracking loops.<<ETX>>","PeriodicalId":323612,"journal":{"name":"Proceedings of MILCOM '93 - IEEE Military Communications Conference","volume":"158 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1993-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116115286","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 : 1993-10-11DOI: 10.1109/MILCOM.1993.408532
M. Busche, C. Lockhart, C. Olszewski, A. Rausch
The authors describe the architecture, algorithms, protocols, and possible uses of a high-speed, demand-assigned network incorporating distributed restoration. Network features include the use of an adaptive, distributed restoration and provisioning algorithm, distributed databases and fiber-associated signaling links which increase the survivability and robustness of the system. The benefit of such a network architecture to users requiring high-speed digital services are that connections (perhaps connecting video or sensor information to collection locations) can be established on-demand, in a manner that bypasses parts of the public switched network (PSN). The restoration aspect of the architecture improves the reliability and survivability of these services in an economic way.<>
{"title":"Network architecture for critical communications requirements","authors":"M. Busche, C. Lockhart, C. Olszewski, A. Rausch","doi":"10.1109/MILCOM.1993.408532","DOIUrl":"https://doi.org/10.1109/MILCOM.1993.408532","url":null,"abstract":"The authors describe the architecture, algorithms, protocols, and possible uses of a high-speed, demand-assigned network incorporating distributed restoration. Network features include the use of an adaptive, distributed restoration and provisioning algorithm, distributed databases and fiber-associated signaling links which increase the survivability and robustness of the system. The benefit of such a network architecture to users requiring high-speed digital services are that connections (perhaps connecting video or sensor information to collection locations) can be established on-demand, in a manner that bypasses parts of the public switched network (PSN). The restoration aspect of the architecture improves the reliability and survivability of these services in an economic way.<<ETX>>","PeriodicalId":323612,"journal":{"name":"Proceedings of MILCOM '93 - IEEE Military Communications Conference","volume":"140 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1993-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116409282","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 : 1993-10-11DOI: 10.1109/MILCOM.1993.408530
G. Knowles
B-ISDN and ATM are being designed to support a variety of voice, data, and video applications over a single network. National and international standards organizations are developing strategies for controlling the effects of traffic congestion conditions. An ATM network model was developed to simulate the performance of selected congestion control schemes. The simulation results support the position of the standards organizations.<>
{"title":"Performance of proposed ATM congestion control techniques","authors":"G. Knowles","doi":"10.1109/MILCOM.1993.408530","DOIUrl":"https://doi.org/10.1109/MILCOM.1993.408530","url":null,"abstract":"B-ISDN and ATM are being designed to support a variety of voice, data, and video applications over a single network. National and international standards organizations are developing strategies for controlling the effects of traffic congestion conditions. An ATM network model was developed to simulate the performance of selected congestion control schemes. The simulation results support the position of the standards organizations.<<ETX>>","PeriodicalId":323612,"journal":{"name":"Proceedings of MILCOM '93 - IEEE Military Communications Conference","volume":"196 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1993-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122378060","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 : 1993-10-11DOI: 10.1109/MILCOM.1993.408511
R. Doyle, A. Sastry
A configurable multiband radio (MBR) with the ability to generate multiple simultaneous waveforms from HF to SHF will play a significant role in future tactical military communications and in facilitating interoperability on the global grid communications infrastructure. The authors initiated work on processing strategies within an MBR with multiple processors. Traffic requirements and processing needs can be expected to vary widely for different channels from HF to SHF. Thus, rather than having dedicated processors, it will be advantageous to allocate processing power to each channel on demand. The authors describe a simulation model to understand the impact of shared processing in a MBR and related issues. They provide details on the simulation structure, the object comprising the simulation, and operation of the simulation. The simulation deals with sharing of MBR processing and RF assets among multiple simultaneous users within a network of such MBRs. A traffic model provides a variety of traffic scenarios including priority, point-to-point and multicast, voice or data media, and datagram, request/response and request/acknowledge protocols. Buffering on sending and receiving side is permitted. The authors conclude with some simulation results indicating tradeoffs between the number of processors and loss of messages due to processing demands, and the impact of task segmentation, buffering, and channel traffic levels.<>
{"title":"Dynamic allocation of processing capacity in a multiband radio","authors":"R. Doyle, A. Sastry","doi":"10.1109/MILCOM.1993.408511","DOIUrl":"https://doi.org/10.1109/MILCOM.1993.408511","url":null,"abstract":"A configurable multiband radio (MBR) with the ability to generate multiple simultaneous waveforms from HF to SHF will play a significant role in future tactical military communications and in facilitating interoperability on the global grid communications infrastructure. The authors initiated work on processing strategies within an MBR with multiple processors. Traffic requirements and processing needs can be expected to vary widely for different channels from HF to SHF. Thus, rather than having dedicated processors, it will be advantageous to allocate processing power to each channel on demand. The authors describe a simulation model to understand the impact of shared processing in a MBR and related issues. They provide details on the simulation structure, the object comprising the simulation, and operation of the simulation. The simulation deals with sharing of MBR processing and RF assets among multiple simultaneous users within a network of such MBRs. A traffic model provides a variety of traffic scenarios including priority, point-to-point and multicast, voice or data media, and datagram, request/response and request/acknowledge protocols. Buffering on sending and receiving side is permitted. The authors conclude with some simulation results indicating tradeoffs between the number of processors and loss of messages due to processing demands, and the impact of task segmentation, buffering, and channel traffic levels.<<ETX>>","PeriodicalId":323612,"journal":{"name":"Proceedings of MILCOM '93 - IEEE Military Communications Conference","volume":"114 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1993-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122705097","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 : 1993-10-11DOI: 10.1109/MILCOM.1993.408502
K. Bogineni, P. Dowd
The authors evaluate the impact of propagation delay on the performance of media access protocols for star-coupled wavelength-division multiplexed (WDM) photonic local area networks. The relative impact on preallocation and reservation based protocols is evaluated. I-SA and I-TDMA are designed for a network where channels are preallocated to the nodes for reception where each node has a home channel it uses for all data packet receptions. TDMA-C is control channel based, with one WDM channel allocated to reserve access for data packet transmission on the remaining data channels. Control channel access arbitration is achieved through time-division multiplexing, enabling all active nodes the opportunity to transmit once every control cycle. The performance of the protocols is evaluated through discrete-event simulation in terms of network throughput, packet delay, and data channel utilization.<>
{"title":"Impact of propagation delay on media access protocol performance for star-coupled WDM local area networks","authors":"K. Bogineni, P. Dowd","doi":"10.1109/MILCOM.1993.408502","DOIUrl":"https://doi.org/10.1109/MILCOM.1993.408502","url":null,"abstract":"The authors evaluate the impact of propagation delay on the performance of media access protocols for star-coupled wavelength-division multiplexed (WDM) photonic local area networks. The relative impact on preallocation and reservation based protocols is evaluated. I-SA and I-TDMA are designed for a network where channels are preallocated to the nodes for reception where each node has a home channel it uses for all data packet receptions. TDMA-C is control channel based, with one WDM channel allocated to reserve access for data packet transmission on the remaining data channels. Control channel access arbitration is achieved through time-division multiplexing, enabling all active nodes the opportunity to transmit once every control cycle. The performance of the protocols is evaluated through discrete-event simulation in terms of network throughput, packet delay, and data channel utilization.<<ETX>>","PeriodicalId":323612,"journal":{"name":"Proceedings of MILCOM '93 - IEEE Military Communications Conference","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1993-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129752160","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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