Pub Date : 2008-12-01DOI: 10.1109/ATNAC.2008.4783354
S. Suthaharan, S. Kumar
Measuring available bandwidth over a network path is required by many applications including end-to-end admission control and server selection. In order to measure the available bandwidth, the end hosts need network information, such as packet delay, at intermediate systems. Several techniques have been proposed to address this problem. We have selected the most recently proposed algorithm called pathChirp and proposed an alternative approach. The main goal of pathChirp is to get the delay information at the intermediate systems by using the concept of self-induced congestion (which uses chirp train packets) in order to estimate the available bandwidth. However there are scenarios where pathChirp cannot provide accurate available bandwidth. We use the pathChirp mechanism as our underlying tool and modify its structure of chirp train. In the modified structure, the rate of the odd inter-chirp packet will be the same as the rate of previous even inter-chirp packet. Additionally, rate of inter-chirp packets will be increased exponentially with even power rather than both even and odd power as done in pathChirp scheme. Purpose of this new structure is to capture more network information using three different time-shifted chirp trains, and subsequently to find a better estimate for the available bandwidth. Our theory and simulation results support this claim.
{"title":"Measuring Available Bandwidth: pathChirp's Chirp Train Structure Remodeled","authors":"S. Suthaharan, S. Kumar","doi":"10.1109/ATNAC.2008.4783354","DOIUrl":"https://doi.org/10.1109/ATNAC.2008.4783354","url":null,"abstract":"Measuring available bandwidth over a network path is required by many applications including end-to-end admission control and server selection. In order to measure the available bandwidth, the end hosts need network information, such as packet delay, at intermediate systems. Several techniques have been proposed to address this problem. We have selected the most recently proposed algorithm called pathChirp and proposed an alternative approach. The main goal of pathChirp is to get the delay information at the intermediate systems by using the concept of self-induced congestion (which uses chirp train packets) in order to estimate the available bandwidth. However there are scenarios where pathChirp cannot provide accurate available bandwidth. We use the pathChirp mechanism as our underlying tool and modify its structure of chirp train. In the modified structure, the rate of the odd inter-chirp packet will be the same as the rate of previous even inter-chirp packet. Additionally, rate of inter-chirp packets will be increased exponentially with even power rather than both even and odd power as done in pathChirp scheme. Purpose of this new structure is to capture more network information using three different time-shifted chirp trains, and subsequently to find a better estimate for the available bandwidth. Our theory and simulation results support this claim.","PeriodicalId":143803,"journal":{"name":"2008 Australasian Telecommunication Networks and Applications Conference","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124329894","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2008-12-01DOI: 10.1109/ATNAC.2008.4783315
C. Kikkert, G. Reid
It is desirable to use existing single wire earth return (SWER) lines for data communication as well as transmitting power in remote areas. The radiation losses of the communication signal is a critical system design parameter. Existing radiation models are not adequate since they assume: firstly that the antenna is a small number of wavelengths long and secondly that the currents along the line are constant, so that no power lost in radiation. The model presented here overcomes these limitations. The model shows that bends in the SWER line significantly effect both the radiated power and the radiation patterns.
{"title":"Radiation Losses from a Single Wire Earth Return Power Line with Bends","authors":"C. Kikkert, G. Reid","doi":"10.1109/ATNAC.2008.4783315","DOIUrl":"https://doi.org/10.1109/ATNAC.2008.4783315","url":null,"abstract":"It is desirable to use existing single wire earth return (SWER) lines for data communication as well as transmitting power in remote areas. The radiation losses of the communication signal is a critical system design parameter. Existing radiation models are not adequate since they assume: firstly that the antenna is a small number of wavelengths long and secondly that the currents along the line are constant, so that no power lost in radiation. The model presented here overcomes these limitations. The model shows that bends in the SWER line significantly effect both the radiated power and the radiation patterns.","PeriodicalId":143803,"journal":{"name":"2008 Australasian Telecommunication Networks and Applications Conference","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129167095","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2008-12-01DOI: 10.1109/ATNAC.2008.4783345
S. Perera, Harsha Sirisena
IEEE 802.16 is a wireless metropolitan area broadband access technology which provides layer two service differentiation for many types of traffic flows. In this paper the transport of uplink best effort traffic from the subscriber to the base station is considered. The performance of best effort service class is analyzed and compared with non-real-time polling service class which can also be used for low priority flows such as file transfer and Web traffic. We propose performance enhancements and modifications to increase the efficiency of the nrtPS class. Namely using a dynamic polling period based on the activity on the connection, using dummy keep alive messages when inactive and releasing idle connections to conserve bandwidth.
{"title":"Servicing Best Effort Traffic Using nrtPS on Fixed WiMAX","authors":"S. Perera, Harsha Sirisena","doi":"10.1109/ATNAC.2008.4783345","DOIUrl":"https://doi.org/10.1109/ATNAC.2008.4783345","url":null,"abstract":"IEEE 802.16 is a wireless metropolitan area broadband access technology which provides layer two service differentiation for many types of traffic flows. In this paper the transport of uplink best effort traffic from the subscriber to the base station is considered. The performance of best effort service class is analyzed and compared with non-real-time polling service class which can also be used for low priority flows such as file transfer and Web traffic. We propose performance enhancements and modifications to increase the efficiency of the nrtPS class. Namely using a dynamic polling period based on the activity on the connection, using dummy keep alive messages when inactive and releasing idle connections to conserve bandwidth.","PeriodicalId":143803,"journal":{"name":"2008 Australasian Telecommunication Networks and Applications Conference","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130220259","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2008-12-01DOI: 10.1109/ATNAC.2008.4783358
M. Hasan, M. L. Kabir
A novel Discrete Fractional Cosine Transform implementation for pitch estimation of noisy speech using dominant harmonic is introduced in this paper. The basic idea is to preprocess the speech signal with discrete fractional cosine transform before using the rectified dominant harmonic for signal reshaping. The performance of the proposed method is tested and compared with the latest previous method using Keele pitch extraction reference database. Comparative results show that the proposed method can detect pitch with better accuracy in terms of gross and fine pitch error as compared to the latest technique.
{"title":"Minimization of Error in Pitch Detection algorithm using Discrete Fractional Cosine Transform","authors":"M. Hasan, M. L. Kabir","doi":"10.1109/ATNAC.2008.4783358","DOIUrl":"https://doi.org/10.1109/ATNAC.2008.4783358","url":null,"abstract":"A novel Discrete Fractional Cosine Transform implementation for pitch estimation of noisy speech using dominant harmonic is introduced in this paper. The basic idea is to preprocess the speech signal with discrete fractional cosine transform before using the rectified dominant harmonic for signal reshaping. The performance of the proposed method is tested and compared with the latest previous method using Keele pitch extraction reference database. Comparative results show that the proposed method can detect pitch with better accuracy in terms of gross and fine pitch error as compared to the latest technique.","PeriodicalId":143803,"journal":{"name":"2008 Australasian Telecommunication Networks and Applications Conference","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116481260","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2008-12-01DOI: 10.1109/ATNAC.2008.4783335
V. Rodriguez, R. Mathar, A. Schmeink
Macro-diversity - all base stations decode cooperatively each received signal - can mitigate shadow fading, and increase the capacity of a spread-spectrum communication network. Assuming that a terminal's transmission power contributes to its own interference, the literature determines whether a vector of quality-of-service targets is feasible through a simple formula, which is insensitive to the terminals' channel gains. Herein, through Banach' contraction-mapping principle - and without the self-interference approximation - a new low-complexity capacity formula is derived. Through its dependence on relative channel gains, the new formula adapts itself in a sensible manner to special conditions, such as when most terminals can only be heard by a subset of the receivers. Under such conditions, the original may significantly overestimate capacity.
{"title":"Capacity and power control in spread spectrum macro-diversity radio networks revisited","authors":"V. Rodriguez, R. Mathar, A. Schmeink","doi":"10.1109/ATNAC.2008.4783335","DOIUrl":"https://doi.org/10.1109/ATNAC.2008.4783335","url":null,"abstract":"Macro-diversity - all base stations decode cooperatively each received signal - can mitigate shadow fading, and increase the capacity of a spread-spectrum communication network. Assuming that a terminal's transmission power contributes to its own interference, the literature determines whether a vector of quality-of-service targets is feasible through a simple formula, which is insensitive to the terminals' channel gains. Herein, through Banach' contraction-mapping principle - and without the self-interference approximation - a new low-complexity capacity formula is derived. Through its dependence on relative channel gains, the new formula adapts itself in a sensible manner to special conditions, such as when most terminals can only be heard by a subset of the receivers. Under such conditions, the original may significantly overestimate capacity.","PeriodicalId":143803,"journal":{"name":"2008 Australasian Telecommunication Networks and Applications Conference","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121191426","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2008-12-01DOI: 10.1109/ATNAC.2008.4783340
A.K.-L. Yau, P. Komisarczuk, Paul D. Teal
Cognitive Radio (CR) exploits underutilized licensed spectrums to improve its bandwidth availability. Using CR technology, a node is able to adapt its transmission and reception radio parameters including channel frequency dynamically according to local spectrum availability. For channel access between wireless nodes, a cognitive Medium Access Control (MAC) protocol is necessary to coordinate the CRs. Multi-channel MAC protocol extensions have been proposed in IEEE802.11 to enable a node to operate in multiple channels in order to improve network-wide throughput. These multi-channel MAC protocols have several functions that can be leveraged by cognitive MAC protocols due to their similarities in certain aspects, though the CR has an additional requirement to cope with the existence of licensed users that have higher authority over the channels. Current research in cognitive MAC protocols assumes the availability of a common control channel at all times, which is an approach in the multi-channel MAC protocols. This approach has certain hardware requirements that may not be readily available at CR nodes. Hence, other approached may be necessary. In this paper, various types of multi-channel MAC protocols are reviewed, followed by discussion of their merits and demerits in multi-channel environments. The purpose is to show the additional functionalities and challenges that each multi-channel MAC protocol has to offer and address in order to operate in multihop CR networks. By providing discussion on possible technology leverage from multi-channel to cognitive MAC protocols, we aim to establish a foundation for further research and discussion.
{"title":"On Multi-Channel MAC Protocols in Cognitive Radio Networks","authors":"A.K.-L. Yau, P. Komisarczuk, Paul D. Teal","doi":"10.1109/ATNAC.2008.4783340","DOIUrl":"https://doi.org/10.1109/ATNAC.2008.4783340","url":null,"abstract":"Cognitive Radio (CR) exploits underutilized licensed spectrums to improve its bandwidth availability. Using CR technology, a node is able to adapt its transmission and reception radio parameters including channel frequency dynamically according to local spectrum availability. For channel access between wireless nodes, a cognitive Medium Access Control (MAC) protocol is necessary to coordinate the CRs. Multi-channel MAC protocol extensions have been proposed in IEEE802.11 to enable a node to operate in multiple channels in order to improve network-wide throughput. These multi-channel MAC protocols have several functions that can be leveraged by cognitive MAC protocols due to their similarities in certain aspects, though the CR has an additional requirement to cope with the existence of licensed users that have higher authority over the channels. Current research in cognitive MAC protocols assumes the availability of a common control channel at all times, which is an approach in the multi-channel MAC protocols. This approach has certain hardware requirements that may not be readily available at CR nodes. Hence, other approached may be necessary. In this paper, various types of multi-channel MAC protocols are reviewed, followed by discussion of their merits and demerits in multi-channel environments. The purpose is to show the additional functionalities and challenges that each multi-channel MAC protocol has to offer and address in order to operate in multihop CR networks. By providing discussion on possible technology leverage from multi-channel to cognitive MAC protocols, we aim to establish a foundation for further research and discussion.","PeriodicalId":143803,"journal":{"name":"2008 Australasian Telecommunication Networks and Applications Conference","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131515295","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2008-12-01DOI: 10.1109/ATNAC.2008.4783311
K. Al-Mawali, A. Sadik, Z. M. Hussain
Impulsive noise is one of the major challenges in power line communications and can cause serious problems in OFDM-based PLC systems. In this paper, we propose a combined Time-Domain/Frequency-domain technique for impulsive noise reduction in OFDM-based PLC systems. The performance of the proposed technique is studied against well known time-domain nonlinearities by means of computer simulations. The obtained simulation results show that the Combined TD/FD technique performs better than practically used nonlinearities and can reduce the adverse effect of impulsive noise significantly.
{"title":"Joint Time-domain/Frequency-domain Impulsive Noise Reduction in OFDM-based Power Line Communications","authors":"K. Al-Mawali, A. Sadik, Z. M. Hussain","doi":"10.1109/ATNAC.2008.4783311","DOIUrl":"https://doi.org/10.1109/ATNAC.2008.4783311","url":null,"abstract":"Impulsive noise is one of the major challenges in power line communications and can cause serious problems in OFDM-based PLC systems. In this paper, we propose a combined Time-Domain/Frequency-domain technique for impulsive noise reduction in OFDM-based PLC systems. The performance of the proposed technique is studied against well known time-domain nonlinearities by means of computer simulations. The obtained simulation results show that the Combined TD/FD technique performs better than practically used nonlinearities and can reduce the adverse effect of impulsive noise significantly.","PeriodicalId":143803,"journal":{"name":"2008 Australasian Telecommunication Networks and Applications Conference","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121474204","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2008-12-01DOI: 10.1109/ATNAC.2008.4783320
Hushairi Zen, D. Habibi, I. Ahmad
Admission control is an important mechanism for sustaining throughput and supporting quality of service (QoS) for real-time traffic in a wireless local area network (WLAN). In an adhoc WLAN scenario where no access point (AP) is available, admission control has to be self-managed by each node. We propose a self-restraining admission control mechanism that works by monitoring the congestion level of the network in the adhoc WLAN. Wireless nodes can listen to all nodes within their range and be aware of the collision rates. A node wishing to join the network measures the current collision rate, and predicts the post-admission collision rate, on the basis of which the self-restraining mechanism in the node decides if it can join the network. We analyse the impact of key parameters, such as the collision threshold level, on the performance of the self-restraining mechanism and show that this mechanism works effectively in sustaining traffic in an adhoc WLAN.
{"title":"Self-restraint Admission Control for adhoc WLANs","authors":"Hushairi Zen, D. Habibi, I. Ahmad","doi":"10.1109/ATNAC.2008.4783320","DOIUrl":"https://doi.org/10.1109/ATNAC.2008.4783320","url":null,"abstract":"Admission control is an important mechanism for sustaining throughput and supporting quality of service (QoS) for real-time traffic in a wireless local area network (WLAN). In an adhoc WLAN scenario where no access point (AP) is available, admission control has to be self-managed by each node. We propose a self-restraining admission control mechanism that works by monitoring the congestion level of the network in the adhoc WLAN. Wireless nodes can listen to all nodes within their range and be aware of the collision rates. A node wishing to join the network measures the current collision rate, and predicts the post-admission collision rate, on the basis of which the self-restraining mechanism in the node decides if it can join the network. We analyse the impact of key parameters, such as the collision threshold level, on the performance of the self-restraining mechanism and show that this mechanism works effectively in sustaining traffic in an adhoc WLAN.","PeriodicalId":143803,"journal":{"name":"2008 Australasian Telecommunication Networks and Applications Conference","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114999094","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2008-12-01DOI: 10.1109/ATNAC.2008.4783293
Xianping Wu, Huy Hoang Ngo, P. D. Le, B. Srinivasan
Protecting sensitive information systems from security threats such as unauthorised access, information eavesdropping and information interfering, is significant. Most of the natural approaches employ strong authentication and/or cryptography systems to protect critical data. But those approaches do not stress on the potential amount of risks associated with sensitive information, especially the vulnerability of long term cryptographic keys. Therefore, in this paper, a secure sensitive information system is proposed and implemented based on a dynamic key generation technique. It associates with elliptic curve key exchange protocol as a design solution for wireless mobile devices to achieve critical information data security and network security.
{"title":"Design & Implementation of a Secure Sensitive Information System for Wireless Mobile Devices","authors":"Xianping Wu, Huy Hoang Ngo, P. D. Le, B. Srinivasan","doi":"10.1109/ATNAC.2008.4783293","DOIUrl":"https://doi.org/10.1109/ATNAC.2008.4783293","url":null,"abstract":"Protecting sensitive information systems from security threats such as unauthorised access, information eavesdropping and information interfering, is significant. Most of the natural approaches employ strong authentication and/or cryptography systems to protect critical data. But those approaches do not stress on the potential amount of risks associated with sensitive information, especially the vulnerability of long term cryptographic keys. Therefore, in this paper, a secure sensitive information system is proposed and implemented based on a dynamic key generation technique. It associates with elliptic curve key exchange protocol as a design solution for wireless mobile devices to achieve critical information data security and network security.","PeriodicalId":143803,"journal":{"name":"2008 Australasian Telecommunication Networks and Applications Conference","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134288431","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2008-09-01DOI: 10.1109/ATNAC.2008.4783329
Mohammed Rahman, Edith Cowan, D. Habibi, I. Ahmad, M. Z. Rahman
Maximum likelihood (ML) is a popular and effective estimator for a wide range of diverse applications and currently affords the most accurate estimation for source localisation in wireless sensor networks (WSN). ML however has two major shortcomings namely, that it is a biased estimator and is also highly sensitive to parameter perturbations. An Optimisation to ML (OML) algorithm was introduced that minimises the sum-of-squares bias and exhibits superior performance to ML in statistical estimation, particularly with finite datasets. This paper proposes a new model for acoustic source localisation in WSN, based upon the OML estimation process. In addition to the performance analysis using real world field experimental data for the tracking of moving military vehicles, simulations have been performed upon the more complex source localisation and tracking problem, to verify the potential of the new OML-based model.
{"title":"Source Localisation in Wireless Sensor Networks Based on Optimised Maximum Likelihood","authors":"Mohammed Rahman, Edith Cowan, D. Habibi, I. Ahmad, M. Z. Rahman","doi":"10.1109/ATNAC.2008.4783329","DOIUrl":"https://doi.org/10.1109/ATNAC.2008.4783329","url":null,"abstract":"Maximum likelihood (ML) is a popular and effective estimator for a wide range of diverse applications and currently affords the most accurate estimation for source localisation in wireless sensor networks (WSN). ML however has two major shortcomings namely, that it is a biased estimator and is also highly sensitive to parameter perturbations. An Optimisation to ML (OML) algorithm was introduced that minimises the sum-of-squares bias and exhibits superior performance to ML in statistical estimation, particularly with finite datasets. This paper proposes a new model for acoustic source localisation in WSN, based upon the OML estimation process. In addition to the performance analysis using real world field experimental data for the tracking of moving military vehicles, simulations have been performed upon the more complex source localisation and tracking problem, to verify the potential of the new OML-based model.","PeriodicalId":143803,"journal":{"name":"2008 Australasian Telecommunication Networks and Applications Conference","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116969468","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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