Pub Date : 2011-11-01DOI: 10.1109/ISWCS.2011.6125381
J. Ramis, G. Femenias, L. Carrasco
State-of-the-art wireless communications standards combine (hybrid) automatic repeat request (HARQ) protocols at the data link control (DLC) layer with adaptive modulation and coding (AMC) strategies at the physical layer. Most previous work on cross-layer modeling of these networks assumes the availability of ideal channel state information (CSI). However, in practical systems the CSI used to perform link adaptation may be outdated. This paper presents a generalized cross-layer multidimensional discrete-time Markov chain (DTMC)-based queuing model that jointly exploits the capabilities of ARQ and AMC, by explicitly accounting for imperfections in the AMC scheme caused by the delay in the CSI feedback channel. Based on the stationary state probability distribution of the proposed multidimensional DTMC, closed-form analytical expressions for performance metrics such as average throughput, queue length, packet delay and packet loss rate are derived, and an analysis of the impact of using outdated CSI on these performance parameters is presented.
{"title":"Cross-layer modeling of AMC/ARQ-based wireless networks with outdated CSI","authors":"J. Ramis, G. Femenias, L. Carrasco","doi":"10.1109/ISWCS.2011.6125381","DOIUrl":"https://doi.org/10.1109/ISWCS.2011.6125381","url":null,"abstract":"State-of-the-art wireless communications standards combine (hybrid) automatic repeat request (HARQ) protocols at the data link control (DLC) layer with adaptive modulation and coding (AMC) strategies at the physical layer. Most previous work on cross-layer modeling of these networks assumes the availability of ideal channel state information (CSI). However, in practical systems the CSI used to perform link adaptation may be outdated. This paper presents a generalized cross-layer multidimensional discrete-time Markov chain (DTMC)-based queuing model that jointly exploits the capabilities of ARQ and AMC, by explicitly accounting for imperfections in the AMC scheme caused by the delay in the CSI feedback channel. Based on the stationary state probability distribution of the proposed multidimensional DTMC, closed-form analytical expressions for performance metrics such as average throughput, queue length, packet delay and packet loss rate are derived, and an analysis of the impact of using outdated CSI on these performance parameters is presented.","PeriodicalId":414065,"journal":{"name":"2011 8th International Symposium on Wireless Communication Systems","volume":"46 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128013262","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-11-01DOI: 10.1109/ISWCS.2011.6125345
Iqbal Shahid, P. Yahampath
In this paper, we present a distributed joint source-channel (DJSC) coding approach for a pair of correlated binary sources transmitted over independent binary symmetric channels. This problem is of interest in wireless sensor network applications, where encoders with low complexity and delay may be required. In the proposed method, a judiciously chosen fraction of information bits and a fraction of parity bits obtained by puncturing the output of a systematic channel code are transmitted for each source. We obtain the achievable rate region for the proposed coding scheme and show that it coincides with the Slepian-Wolf lower bound as the channel error probability approaches zero. Experimental results obtained with a practical implementation based on LDPC codes are also presented which demonstrate that for short coding block lengths (or low delay coding), the proposed DJSC coding method outperforms separate distributed source coding and channel coding.
{"title":"Distributed joint source-channel coding of correlated binary sources in wireless sensor networks","authors":"Iqbal Shahid, P. Yahampath","doi":"10.1109/ISWCS.2011.6125345","DOIUrl":"https://doi.org/10.1109/ISWCS.2011.6125345","url":null,"abstract":"In this paper, we present a distributed joint source-channel (DJSC) coding approach for a pair of correlated binary sources transmitted over independent binary symmetric channels. This problem is of interest in wireless sensor network applications, where encoders with low complexity and delay may be required. In the proposed method, a judiciously chosen fraction of information bits and a fraction of parity bits obtained by puncturing the output of a systematic channel code are transmitted for each source. We obtain the achievable rate region for the proposed coding scheme and show that it coincides with the Slepian-Wolf lower bound as the channel error probability approaches zero. Experimental results obtained with a practical implementation based on LDPC codes are also presented which demonstrate that for short coding block lengths (or low delay coding), the proposed DJSC coding method outperforms separate distributed source coding and channel coding.","PeriodicalId":414065,"journal":{"name":"2011 8th International Symposium on Wireless Communication Systems","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128088721","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-11-01DOI: 10.1109/ISWCS.2011.6125396
Katerina Smiljkovic, Z. Hadzi-Velkov
We derive simple asymptotic expressions for the outage probability (OP) and the average error probability (AEP) of dual-hop fixed-gain amplify-and-forward relaying system with or without direct path in a Rayleigh fading environment and high signal-to-noise ration (SNR). We show that, when direct path is not utilized, both OP and EP decay as log(SNR)/SNR, whereas, when the direct path is utilized, OP and EP decay as log(SNR)/SNR2 at high SNRs.
{"title":"Asymptotic performance of dual-hop non-regenerative cooperative systems with or without direct path","authors":"Katerina Smiljkovic, Z. Hadzi-Velkov","doi":"10.1109/ISWCS.2011.6125396","DOIUrl":"https://doi.org/10.1109/ISWCS.2011.6125396","url":null,"abstract":"We derive simple asymptotic expressions for the outage probability (OP) and the average error probability (AEP) of dual-hop fixed-gain amplify-and-forward relaying system with or without direct path in a Rayleigh fading environment and high signal-to-noise ration (SNR). We show that, when direct path is not utilized, both OP and EP decay as log(SNR)/SNR, whereas, when the direct path is utilized, OP and EP decay as log(SNR)/SNR2 at high SNRs.","PeriodicalId":414065,"journal":{"name":"2011 8th International Symposium on Wireless Communication Systems","volume":"11 2","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114010672","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-11-01DOI: 10.1109/ISWCS.2011.6125367
K. Tateishi, K. Higuchi
This paper presents an adaptive amplify-and-forward (AF)-type relaying method appropriate for the cellular downlink. The proposed method adaptively selects active relay stations (RSs) based on the path loss between each set of user equipment (UE) and the base station (BS) and that between each RS in order to avoid unnecessary enhancement of inter-cell interference and bandwidth reduction due to transmission relay. Furthermore, to enhance the spectrum efficiency when relaying, the frequency used for the relay transmission from the RS to the cell-edge user is reused for the direct transmission from the BS to the cell-center user. Based on computer simulation, the system-level average throughput and cell-edge user throughput of the proposed method are compared to those for a case using no relaying and a conventional repeater. The simulation results show the effectiveness of the proposed method.
{"title":"Adaptive amplify-and-forward relaying for cellular downlink","authors":"K. Tateishi, K. Higuchi","doi":"10.1109/ISWCS.2011.6125367","DOIUrl":"https://doi.org/10.1109/ISWCS.2011.6125367","url":null,"abstract":"This paper presents an adaptive amplify-and-forward (AF)-type relaying method appropriate for the cellular downlink. The proposed method adaptively selects active relay stations (RSs) based on the path loss between each set of user equipment (UE) and the base station (BS) and that between each RS in order to avoid unnecessary enhancement of inter-cell interference and bandwidth reduction due to transmission relay. Furthermore, to enhance the spectrum efficiency when relaying, the frequency used for the relay transmission from the RS to the cell-edge user is reused for the direct transmission from the BS to the cell-center user. Based on computer simulation, the system-level average throughput and cell-edge user throughput of the proposed method are compared to those for a case using no relaying and a conventional repeater. The simulation results show the effectiveness of the proposed method.","PeriodicalId":414065,"journal":{"name":"2011 8th International Symposium on Wireless Communication Systems","volume":"53 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114595747","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-11-01DOI: 10.1109/ISWCS.2011.6125349
D. Schmidt, W. Utschick
The “max-SINR” algorithm and a number of related algorithms have been shown to be very useful for determining good strategies in MIMO interference networks and achieving spatial interference alignment at high SNR. These algorithms, however, rely on being initialized with a “proper” configuration of streams per user, as they do not have the capability of reducing a user's power or deactivating users completely. Alternatively, algorithms for MIMO interference networks can be designed to perform power control, so that interference alignment can be achieved even from an improper initialization. In this paper, we examine one particularly promising such design. We discuss in detail an update procedure based on maximizing the own rate minus a linearized cost of causing interference to other users, a technique known as "interference pricing" for simplicity, we restrict our attention to the case of one stream per user. As previously proposed, we combine the pricing updates with a gradual increase of the transmit power or SNR, which greatly improves the numerical properties. We show with numerical experiments that in an improper system our proposed pricing algorithm with incremental SNR achieves better performance than other algorithms with power control; the fixed-power algorithms, such as the max-SINR algorithm, perform poorly at high SNR.
{"title":"Algorithms for improper single-stream MIMO interference networks","authors":"D. Schmidt, W. Utschick","doi":"10.1109/ISWCS.2011.6125349","DOIUrl":"https://doi.org/10.1109/ISWCS.2011.6125349","url":null,"abstract":"The “max-SINR” algorithm and a number of related algorithms have been shown to be very useful for determining good strategies in MIMO interference networks and achieving spatial interference alignment at high SNR. These algorithms, however, rely on being initialized with a “proper” configuration of streams per user, as they do not have the capability of reducing a user's power or deactivating users completely. Alternatively, algorithms for MIMO interference networks can be designed to perform power control, so that interference alignment can be achieved even from an improper initialization. In this paper, we examine one particularly promising such design. We discuss in detail an update procedure based on maximizing the own rate minus a linearized cost of causing interference to other users, a technique known as \"interference pricing\" for simplicity, we restrict our attention to the case of one stream per user. As previously proposed, we combine the pricing updates with a gradual increase of the transmit power or SNR, which greatly improves the numerical properties. We show with numerical experiments that in an improper system our proposed pricing algorithm with incremental SNR achieves better performance than other algorithms with power control; the fixed-power algorithms, such as the max-SINR algorithm, perform poorly at high SNR.","PeriodicalId":414065,"journal":{"name":"2011 8th International Symposium on Wireless Communication Systems","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117062292","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-11-01DOI: 10.1109/ISWCS.2011.6125427
A. Rao, Mohamed-Slim Alouini
In this paper, we analyze the performance of adaptive modulation with single-cell multiuser scheduling over independent but not identical distributed (i.n.i.d.) Nakagami fading channels. Closed-form expressions are derived for the average channel capacity, spectral efficiency, and bit-error-rate (BER) for both constant-power variable-rate and variable-power variable-rate uncoded M-ary quadrature amplitude modulation (M-QAM) schemes. We also study the impact of time delay on the average BER of adaptive M-QAM. Selected numerical results show that the multiuser diversity brings a considerably better performance even over i.n.i.d. fading environments.
{"title":"Adaptive modulation with best user selection over non-identical Nakagami fading channels","authors":"A. Rao, Mohamed-Slim Alouini","doi":"10.1109/ISWCS.2011.6125427","DOIUrl":"https://doi.org/10.1109/ISWCS.2011.6125427","url":null,"abstract":"In this paper, we analyze the performance of adaptive modulation with single-cell multiuser scheduling over independent but not identical distributed (i.n.i.d.) Nakagami fading channels. Closed-form expressions are derived for the average channel capacity, spectral efficiency, and bit-error-rate (BER) for both constant-power variable-rate and variable-power variable-rate uncoded M-ary quadrature amplitude modulation (M-QAM) schemes. We also study the impact of time delay on the average BER of adaptive M-QAM. Selected numerical results show that the multiuser diversity brings a considerably better performance even over i.n.i.d. fading environments.","PeriodicalId":414065,"journal":{"name":"2011 8th International Symposium on Wireless Communication Systems","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117245575","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-11-01DOI: 10.1109/ISWCS.2011.6125417
T. Murakami, R. Kudo, Y. Asai, T. Kumagai, M. Mizoguchi
Inter-cell interference (ICI) from nearby cells can substantially degrade the sum-rate in WLAN systems. To improve the sum-rate in actual WLAN systems, some papers have investigated distributed multi-cell beamforming to mitigate ICI by zero forcing beamforming. All most of these approaches consider single-user multiple input multiple output (SU-MIMO) systems. In this paper, we present three techniques for distributed multi-cell beamforming for multi-user MIMO (MU-MIMO) systems with the same total number of transmit and receive antennas. The first technique is distributed multi-cell beamforming using receiver selection. The second one is antenna selection at the receiver. The last one is an iterative technique in which transmitter weight is updated at the transmitter to correspond to receiver weight. The sum-rate of these techniques with imperfect channel state information at transmitter (CSIT) is evaluated. We clarify the effectiveness of these techniques for MU-MIMO systems.
{"title":"Performance evaluation of distributed multi-cell beamforming for MU-MIMO systems","authors":"T. Murakami, R. Kudo, Y. Asai, T. Kumagai, M. Mizoguchi","doi":"10.1109/ISWCS.2011.6125417","DOIUrl":"https://doi.org/10.1109/ISWCS.2011.6125417","url":null,"abstract":"Inter-cell interference (ICI) from nearby cells can substantially degrade the sum-rate in WLAN systems. To improve the sum-rate in actual WLAN systems, some papers have investigated distributed multi-cell beamforming to mitigate ICI by zero forcing beamforming. All most of these approaches consider single-user multiple input multiple output (SU-MIMO) systems. In this paper, we present three techniques for distributed multi-cell beamforming for multi-user MIMO (MU-MIMO) systems with the same total number of transmit and receive antennas. The first technique is distributed multi-cell beamforming using receiver selection. The second one is antenna selection at the receiver. The last one is an iterative technique in which transmitter weight is updated at the transmitter to correspond to receiver weight. The sum-rate of these techniques with imperfect channel state information at transmitter (CSIT) is evaluated. We clarify the effectiveness of these techniques for MU-MIMO systems.","PeriodicalId":414065,"journal":{"name":"2011 8th International Symposium on Wireless Communication Systems","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116273376","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-11-01DOI: 10.1109/ISWCS.2011.6125291
Poelzl Christiane
Factors influencing the public' risk perception have already been investigated since the 70s of the last century. With the increased use of mobile telecommunication and the increased public attention to potential health risks from electromagnetic fields, the risk perception and society's dealing with the topic “mobile telecommunication” came into focus. From 2002 to 2008, the German Mobile Telecommunication Research Programme was carried out under the leadership of the Federal Office for Radiation Protection (BfS). Aim of the research programme was to investigate the adequacy of the current limit values regarding the protection against adverse health effects caused by electromagnetic fields. Within the research program also studies on risk perception were conducted. They had the objective to highlight society's perception of the subject “electromagnetic fields of mobile telecommunication in Germany" as a whole and in specific groups, e.g. electromagnetic hypersensitive persons. The paper describes central findings.
{"title":"Mobile telecommunication: Current knowledge on risk perception and risk communication: Results gained within the German Mobile Telecommunication Research Programme","authors":"Poelzl Christiane","doi":"10.1109/ISWCS.2011.6125291","DOIUrl":"https://doi.org/10.1109/ISWCS.2011.6125291","url":null,"abstract":"Factors influencing the public' risk perception have already been investigated since the 70s of the last century. With the increased use of mobile telecommunication and the increased public attention to potential health risks from electromagnetic fields, the risk perception and society's dealing with the topic “mobile telecommunication” came into focus. From 2002 to 2008, the German Mobile Telecommunication Research Programme was carried out under the leadership of the Federal Office for Radiation Protection (BfS). Aim of the research programme was to investigate the adequacy of the current limit values regarding the protection against adverse health effects caused by electromagnetic fields. Within the research program also studies on risk perception were conducted. They had the objective to highlight society's perception of the subject “electromagnetic fields of mobile telecommunication in Germany\" as a whole and in specific groups, e.g. electromagnetic hypersensitive persons. The paper describes central findings.","PeriodicalId":414065,"journal":{"name":"2011 8th International Symposium on Wireless Communication Systems","volume":"284 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115291177","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-11-01DOI: 10.1109/ISWCS.2011.6125372
Henning Zörlein, Dejan E. Lazich, M. Bossert
In this paper, the real-valued Compressed Sensing (CS)-based error correction scheme which was proposed by Candes and Tao is evaluated against the background of channel coding theory. Substantial differences to conventional linear block codes over Galois fields are reviewed and interpreted. A unified channel model is introduced. It enables performance evaluation of more realistic almost sparse channels, which are of interest for communication applications. It is shown by simulations that certain variations of the CS based error correction scheme are suitable for special channels. Additionally, explanations for the noise sensitivity of CS based error correction schemes are given.
{"title":"Performance of error correction based on Compressed Sensing","authors":"Henning Zörlein, Dejan E. Lazich, M. Bossert","doi":"10.1109/ISWCS.2011.6125372","DOIUrl":"https://doi.org/10.1109/ISWCS.2011.6125372","url":null,"abstract":"In this paper, the real-valued Compressed Sensing (CS)-based error correction scheme which was proposed by Candes and Tao is evaluated against the background of channel coding theory. Substantial differences to conventional linear block codes over Galois fields are reviewed and interpreted. A unified channel model is introduced. It enables performance evaluation of more realistic almost sparse channels, which are of interest for communication applications. It is shown by simulations that certain variations of the CS based error correction scheme are suitable for special channels. Additionally, explanations for the noise sensitivity of CS based error correction schemes are given.","PeriodicalId":414065,"journal":{"name":"2011 8th International Symposium on Wireless Communication Systems","volume":"57 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123396736","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-11-01DOI: 10.1109/ISWCS.2011.6125285
Meng Wu, Wenyao Xue, D. Wübben, A. Dekorsy, S. Paul
We consider distributed relaying networks using space-time block codes (STBC) to exploit cooperative diversity. In order to mitigate the impact of error propagation for Decode-Forward (DF), an inter-relay cooperation (IRC) scheme is proposed that allows message exchanges between the relays based on punctured channel codes. Specifically, one of the error-free relays broadcasts punctured bits as side information to help failed relays to re-decode. Consequently, only relays capable of successful decoding transmit to the destination using STBC. Furthermore, an energy model for relays is introduced, so that the proposed IRC scheme can be evaluated with respect to throughput and energy consumptions for transmission, baseband and RF circuit at all relays. Simulation results show the superior performance using IRC, which should be properly designed under the influence of energy considerations.
{"title":"Energy-aware design of inter-relay cooperation for distributed relaying networks","authors":"Meng Wu, Wenyao Xue, D. Wübben, A. Dekorsy, S. Paul","doi":"10.1109/ISWCS.2011.6125285","DOIUrl":"https://doi.org/10.1109/ISWCS.2011.6125285","url":null,"abstract":"We consider distributed relaying networks using space-time block codes (STBC) to exploit cooperative diversity. In order to mitigate the impact of error propagation for Decode-Forward (DF), an inter-relay cooperation (IRC) scheme is proposed that allows message exchanges between the relays based on punctured channel codes. Specifically, one of the error-free relays broadcasts punctured bits as side information to help failed relays to re-decode. Consequently, only relays capable of successful decoding transmit to the destination using STBC. Furthermore, an energy model for relays is introduced, so that the proposed IRC scheme can be evaluated with respect to throughput and energy consumptions for transmission, baseband and RF circuit at all relays. Simulation results show the superior performance using IRC, which should be properly designed under the influence of energy considerations.","PeriodicalId":414065,"journal":{"name":"2011 8th International Symposium on Wireless Communication Systems","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124927742","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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