Pub Date : 2006-07-09DOI: 10.1109/ISIT.2006.261780
Kai Xie, Li Wang, G. Shamir, J. Boutros
Nonsystematic channel codes are superior to systematic codes in the presence of source redundancy. We study the performance of split-LDPC codes (we recently proposed), which are based on splitting redundant data bits into coded bits. We propose a novel method to build extrinsic information transfer (EXIT) chart to approximate the thresholds of such codes. EXIT charts provide a fast and close to accurate prediction of the thresholds of split-LDPC codes for nonuniform sources. The thresholds approximated by fast EXIT chart analysis are very close to those obtained by density evolution (DE) analysis that we recently proposed for split-LDPC codes. The EXIT chart analysis can thus be used to efficiently search for good split-LDPC codes. Simulations verify good performance close to the approximate thresholds predicted by the EXIT charts
{"title":"EXIT Chart Analysis for Split-LDPC Codes","authors":"Kai Xie, Li Wang, G. Shamir, J. Boutros","doi":"10.1109/ISIT.2006.261780","DOIUrl":"https://doi.org/10.1109/ISIT.2006.261780","url":null,"abstract":"Nonsystematic channel codes are superior to systematic codes in the presence of source redundancy. We study the performance of split-LDPC codes (we recently proposed), which are based on splitting redundant data bits into coded bits. We propose a novel method to build extrinsic information transfer (EXIT) chart to approximate the thresholds of such codes. EXIT charts provide a fast and close to accurate prediction of the thresholds of split-LDPC codes for nonuniform sources. The thresholds approximated by fast EXIT chart analysis are very close to those obtained by density evolution (DE) analysis that we recently proposed for split-LDPC codes. The EXIT chart analysis can thus be used to efficiently search for good split-LDPC codes. Simulations verify good performance close to the approximate thresholds predicted by the EXIT charts","PeriodicalId":115298,"journal":{"name":"2006 IEEE International Symposium on Information Theory","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132483976","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 : 2006-07-09DOI: 10.1109/ISIT.2006.261676
S. Draper, A. Sahai
We show how to exploit a noisy feedback link to implement high-reliability communication. We specify a variable-length coding strategy that achieves the error exponent (in delay) of erasure decoding using any noisy feedback channel which has a positive zero-rate random coding error exponent. Building on this result, we give a second approach that, depending only on the capacity of the feedback link, achieves an error exponent up to half of the Burnashev exponent - the maximum exponent that can be achieved with a noiseless feedback link. The resulting exponent can be far larger than the exponent of erasure decoding, particularly at rates close to capacity
{"title":"Noisy feedback improves communication reliability","authors":"S. Draper, A. Sahai","doi":"10.1109/ISIT.2006.261676","DOIUrl":"https://doi.org/10.1109/ISIT.2006.261676","url":null,"abstract":"We show how to exploit a noisy feedback link to implement high-reliability communication. We specify a variable-length coding strategy that achieves the error exponent (in delay) of erasure decoding using any noisy feedback channel which has a positive zero-rate random coding error exponent. Building on this result, we give a second approach that, depending only on the capacity of the feedback link, achieves an error exponent up to half of the Burnashev exponent - the maximum exponent that can be achieved with a noiseless feedback link. The resulting exponent can be far larger than the exponent of erasure decoding, particularly at rates close to capacity","PeriodicalId":115298,"journal":{"name":"2006 IEEE International Symposium on Information Theory","volume":"1999 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132520118","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 : 2006-07-09DOI: 10.1109/ISIT.2006.262062
Yufang Xi, E. Yeh
We present a unified analytical framework within which power control and routing for wireless networks can be optimized on a node-by-node basis. We consider a multicommodity flow model for an interference-limited wireless network in which power control and routing variables are chosen to minimize convex link costs. Distributed scaled gradient projection algorithms are developed to iteratively adjust power control and routing schemes at individual nodes. We specify appropriate scaling matrices with which the algorithms quickly converge to the global optimum from any initial point. These scaling matrices can be computed locally at each node with limited control message overhead
{"title":"Optimal Distributed Power Control and Routing in Wireless Networks","authors":"Yufang Xi, E. Yeh","doi":"10.1109/ISIT.2006.262062","DOIUrl":"https://doi.org/10.1109/ISIT.2006.262062","url":null,"abstract":"We present a unified analytical framework within which power control and routing for wireless networks can be optimized on a node-by-node basis. We consider a multicommodity flow model for an interference-limited wireless network in which power control and routing variables are chosen to minimize convex link costs. Distributed scaled gradient projection algorithms are developed to iteratively adjust power control and routing schemes at individual nodes. We specify appropriate scaling matrices with which the algorithms quickly converge to the global optimum from any initial point. These scaling matrices can be computed locally at each node with limited control message overhead","PeriodicalId":115298,"journal":{"name":"2006 IEEE International Symposium on Information Theory","volume":"79 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130812060","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 : 2006-07-09DOI: 10.1109/ISIT.2006.261696
Jinsong Wu, S. Blostein
This paper proposes a general coordinate-interleaving method for block-based space-time codes or linear dispersion codes, called space-time coordinate interleaving linear dispersion codes (ST-CILDC), which enables not only symbol-level diversity but also coordinate-level diversity for high rate block-based space-time code design. This paper analyzes the upper bound diversity order and provides the analysis results of the upper bound statistical diversity order and average diversity order for ST-CILDC systems. Compared with conventional ST-LDC systems, ST-CILDC systems may show either almost doubled average diversity order or extra coding advantage in time varying channels. With trivial extra complexity over ST-LDC systems, ST-CILDC systems maintain the diversity performance in quasi-static block fading channels, and significantly improve the diversity performance in rapid fading channels
{"title":"Space-time Linear Dispersion Using Coordinate Interleaving","authors":"Jinsong Wu, S. Blostein","doi":"10.1109/ISIT.2006.261696","DOIUrl":"https://doi.org/10.1109/ISIT.2006.261696","url":null,"abstract":"This paper proposes a general coordinate-interleaving method for block-based space-time codes or linear dispersion codes, called space-time coordinate interleaving linear dispersion codes (ST-CILDC), which enables not only symbol-level diversity but also coordinate-level diversity for high rate block-based space-time code design. This paper analyzes the upper bound diversity order and provides the analysis results of the upper bound statistical diversity order and average diversity order for ST-CILDC systems. Compared with conventional ST-LDC systems, ST-CILDC systems may show either almost doubled average diversity order or extra coding advantage in time varying channels. With trivial extra complexity over ST-LDC systems, ST-CILDC systems maintain the diversity performance in quasi-static block fading channels, and significantly improve the diversity performance in rapid fading channels","PeriodicalId":115298,"journal":{"name":"2006 IEEE International Symposium on Information Theory","volume":"273 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126835308","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 : 2006-07-09DOI: 10.1109/ISIT.2006.261892
C. Martínez, Miquel Moretó, R. Beivide, E. Gabidulin
In this paper we present perfect codes for two-dimensional constellations derived from generalized Gaussian graphs, a family of graphs built over quotient rings of Gaussian integers. Using the generalized Gaussian graphs distance, we solve the problem of finding t-dominating sets and, then, we build new perfect codes over these graphs. The well-known perfect Lee codes can be viewed as a particular subcase of the perfect Gaussian codes introduced in this work
{"title":"A Generalization of Perfect Lee Codes over Gaussian Integers","authors":"C. Martínez, Miquel Moretó, R. Beivide, E. Gabidulin","doi":"10.1109/ISIT.2006.261892","DOIUrl":"https://doi.org/10.1109/ISIT.2006.261892","url":null,"abstract":"In this paper we present perfect codes for two-dimensional constellations derived from generalized Gaussian graphs, a family of graphs built over quotient rings of Gaussian integers. Using the generalized Gaussian graphs distance, we solve the problem of finding t-dominating sets and, then, we build new perfect codes over these graphs. The well-known perfect Lee codes can be viewed as a particular subcase of the perfect Gaussian codes introduced in this work","PeriodicalId":115298,"journal":{"name":"2006 IEEE International Symposium on Information Theory","volume":"156 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123280135","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 : 2006-07-09DOI: 10.1109/ISIT.2006.261914
Wen J. Li, H. Dai
Distributed detection of a deterministic signal in correlated Gaussian noise in a one-dimensional sensor network is studied in this paper. In contrast to the traditional approach where a bank of dedicated parallel access channels (PAC) is used for transmitting the sensor observations to the fusion center, we explore the possibility of employing a shared multiple access channel (MAC), which significantly reduces the bandwidth requirement or detection delay. We assume that local observations are mapped according to a certain function subject to a power constraint and transmitted simultaneously to the fusion center. Using a large deviation approach, we demonstrate that with a specially-chosen mapping rule, MAC fusion achieves the same asymptotic performance as centralized detection under the average power constraint (APC), while there is always a loss in error exponents associated with PAC fusion. Under the total power constraint (TPC), MAC fusion still results in exponential decay in error exponents with the number of sensors, while PAC fusion does not. Finally, we derive an upper bound on the performance loss due to the lack of perfect synchronization over MAC, and show that the performance degradation is negligible when the phase mismatch among sensors is sufficiently small
{"title":"Distributed Detection of A Deterministic Signal in Correlated Gaussian Noise Over MAC","authors":"Wen J. Li, H. Dai","doi":"10.1109/ISIT.2006.261914","DOIUrl":"https://doi.org/10.1109/ISIT.2006.261914","url":null,"abstract":"Distributed detection of a deterministic signal in correlated Gaussian noise in a one-dimensional sensor network is studied in this paper. In contrast to the traditional approach where a bank of dedicated parallel access channels (PAC) is used for transmitting the sensor observations to the fusion center, we explore the possibility of employing a shared multiple access channel (MAC), which significantly reduces the bandwidth requirement or detection delay. We assume that local observations are mapped according to a certain function subject to a power constraint and transmitted simultaneously to the fusion center. Using a large deviation approach, we demonstrate that with a specially-chosen mapping rule, MAC fusion achieves the same asymptotic performance as centralized detection under the average power constraint (APC), while there is always a loss in error exponents associated with PAC fusion. Under the total power constraint (TPC), MAC fusion still results in exponential decay in error exponents with the number of sensors, while PAC fusion does not. Finally, we derive an upper bound on the performance loss due to the lack of perfect synchronization over MAC, and show that the performance degradation is negligible when the phase mismatch among sensors is sufficiently small","PeriodicalId":115298,"journal":{"name":"2006 IEEE International Symposium on Information Theory","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121299167","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 : 2006-07-09DOI: 10.1109/ISIT.2006.262039
Guy Bresler, B. Hajek
Bit-error probability and mutual information rate have both been used as performance criteria for space-time codes for wireless communication. We use mutual information as the performance criterion because it determines the possible rate of communication when using an outer code. In this context, linear dispersion codes, first proposed by Hassibi and Hochwald, are appealing because of the high mutual information they provide, as well as their simplicity. Because complexity increases with the number of symbols, it may be sensible in some settings to fix the number of symbols sent per data bit. In the dissertation of Y. Jiang, it was conjectured that among linear dispersion codes with independent, binary symbols, orthogonal space-time codes are optimal in the following sense: they maximize mutual information subject to an average power constraint on each symbol. We prove the conjecture for a fixed number of real symbols with arbitrary distributions
{"title":"Note On Mutual Information and Orthogonal Space-Time Codes","authors":"Guy Bresler, B. Hajek","doi":"10.1109/ISIT.2006.262039","DOIUrl":"https://doi.org/10.1109/ISIT.2006.262039","url":null,"abstract":"Bit-error probability and mutual information rate have both been used as performance criteria for space-time codes for wireless communication. We use mutual information as the performance criterion because it determines the possible rate of communication when using an outer code. In this context, linear dispersion codes, first proposed by Hassibi and Hochwald, are appealing because of the high mutual information they provide, as well as their simplicity. Because complexity increases with the number of symbols, it may be sensible in some settings to fix the number of symbols sent per data bit. In the dissertation of Y. Jiang, it was conjectured that among linear dispersion codes with independent, binary symbols, orthogonal space-time codes are optimal in the following sense: they maximize mutual information subject to an average power constraint on each symbol. We prove the conjecture for a fixed number of real symbols with arbitrary distributions","PeriodicalId":115298,"journal":{"name":"2006 IEEE International Symposium on Information Theory","volume":"58 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121402761","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 : 2006-07-09DOI: 10.1109/ISIT.2006.262059
Junsheng Han, P. Siegel
The stopping redundancy of a linear code is defined as the minimum number of rows in its parity-check matrix such that the smallest stopping sets have size equal to the minimum distance of the code. We derive new upper bounds on the stopping redundancy of maximum distance separable (MDS) codes, and show how they improve upon previously known results. The new bounds are found by upper bounding the stopping redundancy by a combinatorial quantity closely related to Turan numbers. (The Turan number, T(v, k, t), is the smallest number of t-subsets of a v-set, such that every k-subset of the v-set contains at least one of the t-subsets.) Asymptotically, we show that the stopping redundancy of MDS codes with length n and minimum distance d > 1 is T(n, d -1, d - 2)(1 + O(n-1)) for fixed d, and is at most T(n, d - 1, d - 2)(3 + O(n-1)) for fixed code dimension k = n - d + 1. For d = 2,3,4, we prove that the stopping redundancy is equal to T(n, d - 1, d - 2). For d = 5, we show that the stopping redundancy is either T(n, 4, 3) or T(n, 4, 3) + 1
线性码的停止冗余定义为其奇偶校验矩阵中使最小停止集的大小等于码的最小距离的最小行数。我们推导了最大距离可分离码的停止冗余的新上界，并展示了它们如何改进先前已知的结果。通过与图兰数密切相关的一个组合量的停止冗余的上界，找到了新的边界。(图兰数T(v, k, T)是v集的T子集的最小个数，使得v集的每个k子集至少包含一个T子集。)渐近地证明了长度n且最小距离d > 1的MDS码的停止冗余对于固定d为T(n, d -1, d - 2)(1 + O(n-1))，对于固定码维k = n- d + 1，最多为T(n, d -1, d - 2)(3 + O(n-1))。对于d = 2,3,4，我们证明了停止冗余等于T(n, d - 1, d - 2)。对于d = 5，我们证明了停止冗余等于T(n, 4, 3)或T(n, 4, 3) + 1
{"title":"On the Stopping Redundancy of MDS Codes","authors":"Junsheng Han, P. Siegel","doi":"10.1109/ISIT.2006.262059","DOIUrl":"https://doi.org/10.1109/ISIT.2006.262059","url":null,"abstract":"The stopping redundancy of a linear code is defined as the minimum number of rows in its parity-check matrix such that the smallest stopping sets have size equal to the minimum distance of the code. We derive new upper bounds on the stopping redundancy of maximum distance separable (MDS) codes, and show how they improve upon previously known results. The new bounds are found by upper bounding the stopping redundancy by a combinatorial quantity closely related to Turan numbers. (The Turan number, T(v, k, t), is the smallest number of t-subsets of a v-set, such that every k-subset of the v-set contains at least one of the t-subsets.) Asymptotically, we show that the stopping redundancy of MDS codes with length n and minimum distance d > 1 is T(n, d -1, d - 2)(1 + O(n-1)) for fixed d, and is at most T(n, d - 1, d - 2)(3 + O(n-1)) for fixed code dimension k = n - d + 1. For d = 2,3,4, we prove that the stopping redundancy is equal to T(n, d - 1, d - 2). For d = 5, we show that the stopping redundancy is either T(n, 4, 3) or T(n, 4, 3) + 1","PeriodicalId":115298,"journal":{"name":"2006 IEEE International Symposium on Information Theory","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126486173","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 : 2006-07-09DOI: 10.1109/ISIT.2006.261916
Sudhir Srinivasa, S. Jafar, N. Jindal
We explore the capacity of opportunistic secondary (cognitive) communication over a spectral pool of two independent channels. Due to the distributed nature of the primary user's spectral activity, the cognitive receiver does not have full knowledge of the channel used at the transmitter for secondary communication. Tracking the transmitter state at the receiver is therefore a primary issue in such channels. The problem is further complicated as the channel availability changes with time. The tracking uncertainty also makes decoding at the receiver non-trivial. Using genie based outer bounds and training based lower bounds, we estimate the capacity of the secondary link. The capacity analysis shows that the benefits of spectral pooling are lost in dynamic spectral environments
{"title":"On the Capacity of the Cognitive Tracking Channel","authors":"Sudhir Srinivasa, S. Jafar, N. Jindal","doi":"10.1109/ISIT.2006.261916","DOIUrl":"https://doi.org/10.1109/ISIT.2006.261916","url":null,"abstract":"We explore the capacity of opportunistic secondary (cognitive) communication over a spectral pool of two independent channels. Due to the distributed nature of the primary user's spectral activity, the cognitive receiver does not have full knowledge of the channel used at the transmitter for secondary communication. Tracking the transmitter state at the receiver is therefore a primary issue in such channels. The problem is further complicated as the channel availability changes with time. The tracking uncertainty also makes decoding at the receiver non-trivial. Using genie based outer bounds and training based lower bounds, we estimate the capacity of the secondary link. The capacity analysis shows that the benefits of spectral pooling are lost in dynamic spectral environments","PeriodicalId":115298,"journal":{"name":"2006 IEEE International Symposium on Information Theory","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122318453","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 : 2006-07-09DOI: 10.1109/ISIT.2006.262057
R. Ahlswede, C. Deppe, V. Lebedev
The two models described in this paper having as ingredients feedback resp. localized errors give possibilities for code constructions not available in the standard model of error correction and also for probabilistic channel models. For the feedback model we present here a coding scheme, which we call the rubber method, because it is based on erasing letters. It is the first scheme achieving the capacity curve for q ges 3. It could be discovered only in the g-ary case for q ges 3, because the letter zero is not used as an information symbol, but solely for error correction. However an extension of the method from using single zeros to blocks of zeros also gives Berlekamp's result - by a different scheme. In the model with feedback and localized errors the help of feedback is addressed. We give an optimal construction for one-error correcting codes with feedback and localized errors
{"title":"Non-binary error correcting codes with noiseless feedback, localized errors, or both","authors":"R. Ahlswede, C. Deppe, V. Lebedev","doi":"10.1109/ISIT.2006.262057","DOIUrl":"https://doi.org/10.1109/ISIT.2006.262057","url":null,"abstract":"The two models described in this paper having as ingredients feedback resp. localized errors give possibilities for code constructions not available in the standard model of error correction and also for probabilistic channel models. For the feedback model we present here a coding scheme, which we call the rubber method, because it is based on erasing letters. It is the first scheme achieving the capacity curve for q ges 3. It could be discovered only in the g-ary case for q ges 3, because the letter zero is not used as an information symbol, but solely for error correction. However an extension of the method from using single zeros to blocks of zeros also gives Berlekamp's result - by a different scheme. In the model with feedback and localized errors the help of feedback is addressed. We give an optimal construction for one-error correcting codes with feedback and localized errors","PeriodicalId":115298,"journal":{"name":"2006 IEEE International Symposium on Information Theory","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120955010","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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