Pub Date : 2006-04-10DOI: 10.1109/ISWPC.2006.1613607
S. Ali, A. Fakoorian, H. Taheri
With the increasing popularity of wireless communication systems, customers are expecting the same quality of service (QoS), availability and performance from the wireless communication networks as the traditional wire-line networks. Currently the research work on radio channel allocation in cellular mobile systems focuses mainly on two aspects, improving the user admission capability and protecting the connection continuity for handoff calls as a QoS constraint. However, given a QoS constraint, a wireless network has to sacrifice its capacity in order to support an increase in handoff rate. In this paper, we propose and analyze a different handoff scheme which not only gives priority to handoff calls, due to importance of them from QoS standpoint, but also protects originating calls to keep system capacity at an acceptable level. In channel reservation schemes, there are some periods that reserved channels are not actively utilized. In this paper, these periods are defined as dead time. Indeed, our scheme mathematically analyzes the mean dead time. We use a system model defined by a two dimensional Markov chain which computes mathematically the performance in terms of the mean dead time, blocking probability of originating calls, forced termination probability and call incompletion probability. Results are compared with conventional predictive channel reservation (PCR) and guard channel (GC) schemes.
{"title":"Protection of originating calls in handoff prioritization schemes","authors":"S. Ali, A. Fakoorian, H. Taheri","doi":"10.1109/ISWPC.2006.1613607","DOIUrl":"https://doi.org/10.1109/ISWPC.2006.1613607","url":null,"abstract":"With the increasing popularity of wireless communication systems, customers are expecting the same quality of service (QoS), availability and performance from the wireless communication networks as the traditional wire-line networks. Currently the research work on radio channel allocation in cellular mobile systems focuses mainly on two aspects, improving the user admission capability and protecting the connection continuity for handoff calls as a QoS constraint. However, given a QoS constraint, a wireless network has to sacrifice its capacity in order to support an increase in handoff rate. In this paper, we propose and analyze a different handoff scheme which not only gives priority to handoff calls, due to importance of them from QoS standpoint, but also protects originating calls to keep system capacity at an acceptable level. In channel reservation schemes, there are some periods that reserved channels are not actively utilized. In this paper, these periods are defined as dead time. Indeed, our scheme mathematically analyzes the mean dead time. We use a system model defined by a two dimensional Markov chain which computes mathematically the performance in terms of the mean dead time, blocking probability of originating calls, forced termination probability and call incompletion probability. Results are compared with conventional predictive channel reservation (PCR) and guard channel (GC) schemes.","PeriodicalId":145728,"journal":{"name":"2006 1st International Symposium on Wireless Pervasive Computing","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2006-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126156310","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 : 2006-04-10DOI: 10.1109/ISWPC.2006.1613635
L. Angrisani, A. Botta, A. Pescapé, M. Vadursi
Capacity of a link is a key metric for network design and management. Several tools for capacity measurement are present in the literature and they provide satisfying results when used over wired networks. Their performance over wireless links, however, is not as good, although the techniques they are based on should not suffer from changes at physical layer. This paper accounts for a performance assessment of four tools for capacity measurement, carried out over a wireless link located in a semi-anechoic chamber. The measurement station is designed to guarantee channel stationarity and interference-free measurement conditions, and the performance assessment takes advantage of a proper reference value for the measurand, which is obtained from physical layer measurements. The experimental analysis highlights that the performance of the tools is strongly dependent on the characteristics of the network interface cards that are used, whereas the reference value of capacity, measured at physical layer, does not actually change.
{"title":"Measuring wireless links capacity","authors":"L. Angrisani, A. Botta, A. Pescapé, M. Vadursi","doi":"10.1109/ISWPC.2006.1613635","DOIUrl":"https://doi.org/10.1109/ISWPC.2006.1613635","url":null,"abstract":"Capacity of a link is a key metric for network design and management. Several tools for capacity measurement are present in the literature and they provide satisfying results when used over wired networks. Their performance over wireless links, however, is not as good, although the techniques they are based on should not suffer from changes at physical layer. This paper accounts for a performance assessment of four tools for capacity measurement, carried out over a wireless link located in a semi-anechoic chamber. The measurement station is designed to guarantee channel stationarity and interference-free measurement conditions, and the performance assessment takes advantage of a proper reference value for the measurand, which is obtained from physical layer measurements. The experimental analysis highlights that the performance of the tools is strongly dependent on the characteristics of the network interface cards that are used, whereas the reference value of capacity, measured at physical layer, does not actually change.","PeriodicalId":145728,"journal":{"name":"2006 1st International Symposium on Wireless Pervasive Computing","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2006-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122755327","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 : 2006-04-10DOI: 10.1109/ISWPC.2006.1613574
J. Salo, H. El-Sallabi, P. Vainikainen
Double-Rayleigh amplitude distribution, induced by double scattering in the radio channel, occurs in a variety of propagation scenarios, including propagation via diffracting wedges. It is unknown, however, how double scattering affects communication link performance. In this paper, an expression for symbol error probability for some common communication schemes over double-Rayleigh fading wireless channels is derived. It is shown that double scattering results in severe degradation in symbol error probability. Interestingly, our analysis suggests that for the double-Rayleigh channel there exists no meaningful diversity order for the SNR values of practical interest.
{"title":"Impact of double-Rayleigh fading on system performance","authors":"J. Salo, H. El-Sallabi, P. Vainikainen","doi":"10.1109/ISWPC.2006.1613574","DOIUrl":"https://doi.org/10.1109/ISWPC.2006.1613574","url":null,"abstract":"Double-Rayleigh amplitude distribution, induced by double scattering in the radio channel, occurs in a variety of propagation scenarios, including propagation via diffracting wedges. It is unknown, however, how double scattering affects communication link performance. In this paper, an expression for symbol error probability for some common communication schemes over double-Rayleigh fading wireless channels is derived. It is shown that double scattering results in severe degradation in symbol error probability. Interestingly, our analysis suggests that for the double-Rayleigh channel there exists no meaningful diversity order for the SNR values of practical interest.","PeriodicalId":145728,"journal":{"name":"2006 1st International Symposium on Wireless Pervasive Computing","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2006-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128267285","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 : 2006-04-10DOI: 10.1109/ISWPC.2006.1613647
R. Alves, A. Gameiro
In this communication we consider the use of PPM based modulation methods, such as the hybrid modulation method called amplitude and pulse-position modulation (APPM) and overlapping pulse-position modulation (OPPM) to improve the performance of infrared WLAN's, by the use of trellis-coded modulation (TCM) codes. We describe the best code search and results, which demonstrate that, even with trellis codes of moderate complexity, non-negligible coding gains can be obtained without bandwidth expansion. Monte Carlo simulations have been done to compare uncoded PPM against APPM and OPPM TCM coded systems performances, on ceiling-bounce channel models for various values of delay spread. Although our codes were derived for the AWGN channel without inter-symbol interference (ISI) awareness, their behavior in multipath dispersion channels is quite effective.
{"title":"TCM coding of PPM based modulations for infrared WLAN's impaired by ISI","authors":"R. Alves, A. Gameiro","doi":"10.1109/ISWPC.2006.1613647","DOIUrl":"https://doi.org/10.1109/ISWPC.2006.1613647","url":null,"abstract":"In this communication we consider the use of PPM based modulation methods, such as the hybrid modulation method called amplitude and pulse-position modulation (APPM) and overlapping pulse-position modulation (OPPM) to improve the performance of infrared WLAN's, by the use of trellis-coded modulation (TCM) codes. We describe the best code search and results, which demonstrate that, even with trellis codes of moderate complexity, non-negligible coding gains can be obtained without bandwidth expansion. Monte Carlo simulations have been done to compare uncoded PPM against APPM and OPPM TCM coded systems performances, on ceiling-bounce channel models for various values of delay spread. Although our codes were derived for the AWGN channel without inter-symbol interference (ISI) awareness, their behavior in multipath dispersion channels is quite effective.","PeriodicalId":145728,"journal":{"name":"2006 1st International Symposium on Wireless Pervasive Computing","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2006-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124587689","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 : 2006-04-10DOI: 10.1109/ISWPC.2006.1613637
Meng-Lin Hsia, O. Chen
In this work, a multi-band CMOS Voltage Control Oscillator (VCO) using the LC tank technique is developed to meet phase noise requirements of GSM, DCS, DECT, WCDMA(CDMA2000) and Bluetooth. To accomplish the multi-band receiving architecture at a low hardware cost, the proposed VCO based on switched capacitors and cross-coupled transistors without tail transistors is designed to yield quadrature output signals. Our Quadrature VCO (QVCO) fabricated by the TSMC 0.18um 1P6M CMOS technology is operated at 1V with a die size of 0.95mm2. At 600-kHz offset, the phase noises of the proposed QVCO are -124dBc/Hz, -122dBc/Hz, -125dBc/Hz, -118dBc/Hz and -124dBc/Hz at 0.9GHz, 1.8GHz, 1.9GHz, 2.2GHz and 2.4GHz, respectively. Therefore, the proposed QVCO is demonstrated to have sufficiently good performance for these standard applications.
{"title":"A Multi-Band CMOS LC Quadrature VCO for GSM/DCS/DECT/WCDMA/Bluetooth Systems","authors":"Meng-Lin Hsia, O. Chen","doi":"10.1109/ISWPC.2006.1613637","DOIUrl":"https://doi.org/10.1109/ISWPC.2006.1613637","url":null,"abstract":"In this work, a multi-band CMOS Voltage Control Oscillator (VCO) using the LC tank technique is developed to meet phase noise requirements of GSM, DCS, DECT, WCDMA(CDMA2000) and Bluetooth. To accomplish the multi-band receiving architecture at a low hardware cost, the proposed VCO based on switched capacitors and cross-coupled transistors without tail transistors is designed to yield quadrature output signals. Our Quadrature VCO (QVCO) fabricated by the TSMC 0.18um 1P6M CMOS technology is operated at 1V with a die size of 0.95mm2. At 600-kHz offset, the phase noises of the proposed QVCO are -124dBc/Hz, -122dBc/Hz, -125dBc/Hz, -118dBc/Hz and -124dBc/Hz at 0.9GHz, 1.8GHz, 1.9GHz, 2.2GHz and 2.4GHz, respectively. Therefore, the proposed QVCO is demonstrated to have sufficiently good performance for these standard applications.","PeriodicalId":145728,"journal":{"name":"2006 1st International Symposium on Wireless Pervasive Computing","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2006-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127016770","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 : 2006-04-10DOI: 10.1109/ISWPC.2006.1613651
F. Rashid, A. Manikas
Orthogonal frequency division multiplexing (OFDM) is a multicarrier modulation scheme that achieves high spectral efficiency by using minimally densely spaced orthogonal subcarriers without increasing the transmitter and receiver complexities. Antenna arrays are a powerful means to exploit the spatial domain to provide an extra layer of co-channel interference cancellation and new ways of handling unwanted channel effects for more efficient utilization of spectrum and space at any time. An array-OFDM system integrates OFDM and antenna array technology to harness the spatial signatures of received signals. This provides space diversity in multipath channels, making it possible to realize high transmission rates envisioned for the next generation wireless communications. In this paper, a diversity reception algorithm is proposed for post-FFT OFDM systems employing an antenna array at the receiver. Simulation studies show that the proposed array-OFDM scheme outperforms the conventional multiple-element-OFDM receiver under various frequency-selective fading models.
{"title":"Diversity reception for OFDM systems using antenna arrays","authors":"F. Rashid, A. Manikas","doi":"10.1109/ISWPC.2006.1613651","DOIUrl":"https://doi.org/10.1109/ISWPC.2006.1613651","url":null,"abstract":"Orthogonal frequency division multiplexing (OFDM) is a multicarrier modulation scheme that achieves high spectral efficiency by using minimally densely spaced orthogonal subcarriers without increasing the transmitter and receiver complexities. Antenna arrays are a powerful means to exploit the spatial domain to provide an extra layer of co-channel interference cancellation and new ways of handling unwanted channel effects for more efficient utilization of spectrum and space at any time. An array-OFDM system integrates OFDM and antenna array technology to harness the spatial signatures of received signals. This provides space diversity in multipath channels, making it possible to realize high transmission rates envisioned for the next generation wireless communications. In this paper, a diversity reception algorithm is proposed for post-FFT OFDM systems employing an antenna array at the receiver. Simulation studies show that the proposed array-OFDM scheme outperforms the conventional multiple-element-OFDM receiver under various frequency-selective fading models.","PeriodicalId":145728,"journal":{"name":"2006 1st International Symposium on Wireless Pervasive Computing","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2006-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132029796","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 : 2006-04-10DOI: 10.1109/ISWPC.2006.1613611
S. Kawakubo, A. Chansavang, S. Tanaka, T. Iwasaki, K. Sasaki, T. Hirota, H. Hosaka, H. Ando
A local positioning system utilizing propagation loss of Bluetooth wireless technology is developed for indoor human positioning. The distance between a fixed station and a mobile station carried by a person is derived from the propagation loss. The position of the person is calculated from distance measurements on three different fixed stations. The positioning accuracy was 1.2 m at average fixed station installation density of one station in every 8.3 m/sup 2/. The system is intended for tracking worker's position in a work environment such as in shipyards.
{"title":"Wireless network system for indoor human positioning","authors":"S. Kawakubo, A. Chansavang, S. Tanaka, T. Iwasaki, K. Sasaki, T. Hirota, H. Hosaka, H. Ando","doi":"10.1109/ISWPC.2006.1613611","DOIUrl":"https://doi.org/10.1109/ISWPC.2006.1613611","url":null,"abstract":"A local positioning system utilizing propagation loss of Bluetooth wireless technology is developed for indoor human positioning. The distance between a fixed station and a mobile station carried by a person is derived from the propagation loss. The position of the person is calculated from distance measurements on three different fixed stations. The positioning accuracy was 1.2 m at average fixed station installation density of one station in every 8.3 m/sup 2/. The system is intended for tracking worker's position in a work environment such as in shipyards.","PeriodicalId":145728,"journal":{"name":"2006 1st International Symposium on Wireless Pervasive Computing","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2006-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131162255","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 : 2006-04-10DOI: 10.1109/ISWPC.2006.1613570
T. Ristaniemi, T. Huovinen
A recent idea is to use blind source separation (BSS) methods within successive interference cancellation (SIC) in DS-CDMA reception. This has been found to results in an interference cancellation solution, that is able to i) mitigate different kinds of interference sources (e.g. multi-access, multi-path and out-of-cell interferences) simultaneously, ii) tackle "more sources than observations"-problem and, consequently, operate in highly loaded systems and iii) deal with imperfect channel estimation better than conventional BSS receiver and conventional interference cancellation. Thus far however, a single path channel has been assumed in studies behind these findings. In this paper we extend our previous studies to multipath channels where inter-path interference hardens the joint delay tracking and interference cancellation problem even more.
{"title":"Joint Multipath Delay Tracking and Interference Cancellation in DS-CDMA Systems Using Successive ICA for Oversaturated Data","authors":"T. Ristaniemi, T. Huovinen","doi":"10.1109/ISWPC.2006.1613570","DOIUrl":"https://doi.org/10.1109/ISWPC.2006.1613570","url":null,"abstract":"A recent idea is to use blind source separation (BSS) methods within successive interference cancellation (SIC) in DS-CDMA reception. This has been found to results in an interference cancellation solution, that is able to i) mitigate different kinds of interference sources (e.g. multi-access, multi-path and out-of-cell interferences) simultaneously, ii) tackle \"more sources than observations\"-problem and, consequently, operate in highly loaded systems and iii) deal with imperfect channel estimation better than conventional BSS receiver and conventional interference cancellation. Thus far however, a single path channel has been assumed in studies behind these findings. In this paper we extend our previous studies to multipath channels where inter-path interference hardens the joint delay tracking and interference cancellation problem even more.","PeriodicalId":145728,"journal":{"name":"2006 1st International Symposium on Wireless Pervasive Computing","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2006-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132158327","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 : 2006-04-10DOI: 10.1109/ISWPC.2006.1613563
Shensheng Tang
An analytical traffic flow model is developed for cluster-based wireless sensor networks. The source-to-sink path is modeled by a number of single-server finite queues linked in tandem. During the process of modeling, both the blocking effect of tandem queuing networks and the impact of connection failure due to limited node power are taken into account. The tandem queuing network is analyzed by decomposing it into individual nodes with modified arrival and service processes and modified queue capacities. The steady-state queue-length distributions of individual nodes are determined iteratively by using the matrix-geometric procedure. A computational algorithm with a global loop from the last node to the first node and local loops in individual nodes is developed to determine the performance metrics, such as source-to-sink throughput (SST) and source-to-sink delay (SSD), of the tandem network.
{"title":"An analytical traffic flow model for cluster-based wireless sensor networks","authors":"Shensheng Tang","doi":"10.1109/ISWPC.2006.1613563","DOIUrl":"https://doi.org/10.1109/ISWPC.2006.1613563","url":null,"abstract":"An analytical traffic flow model is developed for cluster-based wireless sensor networks. The source-to-sink path is modeled by a number of single-server finite queues linked in tandem. During the process of modeling, both the blocking effect of tandem queuing networks and the impact of connection failure due to limited node power are taken into account. The tandem queuing network is analyzed by decomposing it into individual nodes with modified arrival and service processes and modified queue capacities. The steady-state queue-length distributions of individual nodes are determined iteratively by using the matrix-geometric procedure. A computational algorithm with a global loop from the last node to the first node and local loops in individual nodes is developed to determine the performance metrics, such as source-to-sink throughput (SST) and source-to-sink delay (SSD), of the tandem network.","PeriodicalId":145728,"journal":{"name":"2006 1st International Symposium on Wireless Pervasive Computing","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2006-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133141689","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 : 2006-04-10DOI: 10.1109/ISWPC.2006.1613634
Yihu Li, A. Safwat
Using directional antennas in wireless ad hoc networks can significantly improve network performance. However, serious problems, such as the deafness and hidden terminal problems, greatly limit the network performance. This paper proposes a new MAC scheme, namely DMAC-DACA, to address these problems. Simulation results show that DMAC-DACA alleviates the deafness problem and greatly improves the network throughput. This paper also reveals that the deafness problem has a much greater impact on the network performance compared to the hidden terminal problem.
{"title":"DMAC-DACA: enabling efficient medium access for wireless ad hoc networks with directional antennas","authors":"Yihu Li, A. Safwat","doi":"10.1109/ISWPC.2006.1613634","DOIUrl":"https://doi.org/10.1109/ISWPC.2006.1613634","url":null,"abstract":"Using directional antennas in wireless ad hoc networks can significantly improve network performance. However, serious problems, such as the deafness and hidden terminal problems, greatly limit the network performance. This paper proposes a new MAC scheme, namely DMAC-DACA, to address these problems. Simulation results show that DMAC-DACA alleviates the deafness problem and greatly improves the network throughput. This paper also reveals that the deafness problem has a much greater impact on the network performance compared to the hidden terminal problem.","PeriodicalId":145728,"journal":{"name":"2006 1st International Symposium on Wireless Pervasive Computing","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2006-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133238747","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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