Pub Date : 2019-09-26DOI: 10.1109/ISIT.2019.8849800
Cédric Bleuler, A. Lapidoth, Christoph Pfister
For gambling on horses, a one-parameter family of utility functions is proposed, which contains Kelly’s logarithmic criterion and the expected-return criterion as special cases. The strategies that maximize the utility function are derived, and the connection to the Rényi divergence is shown. Optimal strategies are also derived when the gambler has some side information; this setting leads to a novel conditional Rényi divergence.
{"title":"Gambling and Rényi Divergence","authors":"Cédric Bleuler, A. Lapidoth, Christoph Pfister","doi":"10.1109/ISIT.2019.8849800","DOIUrl":"https://doi.org/10.1109/ISIT.2019.8849800","url":null,"abstract":"For gambling on horses, a one-parameter family of utility functions is proposed, which contains Kelly’s logarithmic criterion and the expected-return criterion as special cases. The strategies that maximize the utility function are derived, and the connection to the Rényi divergence is shown. Optimal strategies are also derived when the gambler has some side information; this setting leads to a novel conditional Rényi divergence.","PeriodicalId":6708,"journal":{"name":"2019 IEEE International Symposium on Information Theory (ISIT)","volume":"18 1","pages":"2214-2218"},"PeriodicalIF":0.0,"publicationDate":"2019-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76015630","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 : 2019-07-11DOI: 10.1109/ISIT.2019.8849236
Hyegyeong Park, J. Moon
In this paper, we consider the straggler problem of the high-dimensional matrix multiplication over distributed workers. To tackle this problem, we propose an irregular-product-coded computation, which is a generalized scheme of the standard-product-coded computation proposed in [1]. Introducing the irregularity to the product-coded matrix multiplication, one can further speed up the matrix multiplication, enjoying the low decoding complexity of the product code. The idea behind the irregular product code introduced in [2] is allowing different code rates for the row and column constituent codes of the product code. We provide a latency analysis of the proposed irregular-product-coded computation. In terms of the total execution time, which is defined by a function of the computation time and decoding time, it is shown that the irregular-product-coded scheme outperforms other competing schemes including the replication, MDS-coded and standard-product-coded schemes in a specific regime.
{"title":"Irregular Product Coded Computation for High-Dimensional Matrix Multiplication","authors":"Hyegyeong Park, J. Moon","doi":"10.1109/ISIT.2019.8849236","DOIUrl":"https://doi.org/10.1109/ISIT.2019.8849236","url":null,"abstract":"In this paper, we consider the straggler problem of the high-dimensional matrix multiplication over distributed workers. To tackle this problem, we propose an irregular-product-coded computation, which is a generalized scheme of the standard-product-coded computation proposed in [1]. Introducing the irregularity to the product-coded matrix multiplication, one can further speed up the matrix multiplication, enjoying the low decoding complexity of the product code. The idea behind the irregular product code introduced in [2] is allowing different code rates for the row and column constituent codes of the product code. We provide a latency analysis of the proposed irregular-product-coded computation. In terms of the total execution time, which is defined by a function of the computation time and decoding time, it is shown that the irregular-product-coded scheme outperforms other competing schemes including the replication, MDS-coded and standard-product-coded schemes in a specific regime.","PeriodicalId":6708,"journal":{"name":"2019 IEEE International Symposium on Information Theory (ISIT)","volume":"2 1","pages":"1782-1786"},"PeriodicalIF":0.0,"publicationDate":"2019-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76059523","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 : 2019-07-07DOI: 10.1109/ISIT.2019.8849331
Xuan Guang, R. Yeung
In the paradigm of network coding, information-theoretic security is considered in the presence of wiretappers, who can access one arbitrary edge subset up to a certain size, referred to as the security level. Secure network coding is applied to prevent the leakage of the source information to the wiretappers. In this paper, we consider the problem of secure network coding for flexible pairs of information rate and security level with any fixed dimension (equal to the sum of rate and security level). We present a novel approach for designing a secure linear network code (SLNC) such that the same SLNC can be applied for all the rate and security-level pairs with the fixed dimension. We further develop a polynomial-time algorithm for efficient implementation and prove that there is no penalty on the required field size for the existence of SLNCs in terms of the best known lower bound by Guang and Yeung. Finally, by applying our approach as a crucial building block, we can construct a family of SLNCs that not only can be applied to all possible pairs of rate and security level but also share a common local encoding kernel at each intermediate node in the network.
{"title":"Local-Encoding-Preserving Secure Network Coding for Fixed Dimension","authors":"Xuan Guang, R. Yeung","doi":"10.1109/ISIT.2019.8849331","DOIUrl":"https://doi.org/10.1109/ISIT.2019.8849331","url":null,"abstract":"In the paradigm of network coding, information-theoretic security is considered in the presence of wiretappers, who can access one arbitrary edge subset up to a certain size, referred to as the security level. Secure network coding is applied to prevent the leakage of the source information to the wiretappers. In this paper, we consider the problem of secure network coding for flexible pairs of information rate and security level with any fixed dimension (equal to the sum of rate and security level). We present a novel approach for designing a secure linear network code (SLNC) such that the same SLNC can be applied for all the rate and security-level pairs with the fixed dimension. We further develop a polynomial-time algorithm for efficient implementation and prove that there is no penalty on the required field size for the existence of SLNCs in terms of the best known lower bound by Guang and Yeung. Finally, by applying our approach as a crucial building block, we can construct a family of SLNCs that not only can be applied to all possible pairs of rate and security level but also share a common local encoding kernel at each intermediate node in the network.","PeriodicalId":6708,"journal":{"name":"2019 IEEE International Symposium on Information Theory (ISIT)","volume":"21 1","pages":"201-205"},"PeriodicalIF":0.0,"publicationDate":"2019-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77514278","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 : 2019-07-07DOI: 10.1109/ISIT.2019.8849476
Yashas Malur Saidutta, A. Abdi, F. Fekri
In this paper, we study joint source-channel coding of gaussian sources over multiple AWGN channels where the source dimension is greater than the number of channels. We model our system as a Variational Autoencoder and show that its loss function takes up a form that is an upper bound on the optimization function got from rate-distortion theory. The constructed system employs two encoders that learn to split the source input space into almost half with no constraints. The system is jointly trained in a data-driven manner, end-to-end. We achieve state of the art results for certain configurations, some of which are 0.7dB better than previous works. We also showcase that the trained encoder/decoder is robust, i.e., even if the channel conditions change by +/-5dB, the performance of the system does not vary by more than 0.7dB w.r.t. a system trained at that channel condition. The trained system, to an extent, has the ability to generalize when a single input dimension is dropped and for some scenarios it is less than 1dB away from the system trained for that reduced dimension.
{"title":"Joint Source-Channel Coding for Gaussian Sources over AWGN Channels using Variational Autoencoders","authors":"Yashas Malur Saidutta, A. Abdi, F. Fekri","doi":"10.1109/ISIT.2019.8849476","DOIUrl":"https://doi.org/10.1109/ISIT.2019.8849476","url":null,"abstract":"In this paper, we study joint source-channel coding of gaussian sources over multiple AWGN channels where the source dimension is greater than the number of channels. We model our system as a Variational Autoencoder and show that its loss function takes up a form that is an upper bound on the optimization function got from rate-distortion theory. The constructed system employs two encoders that learn to split the source input space into almost half with no constraints. The system is jointly trained in a data-driven manner, end-to-end. We achieve state of the art results for certain configurations, some of which are 0.7dB better than previous works. We also showcase that the trained encoder/decoder is robust, i.e., even if the channel conditions change by +/-5dB, the performance of the system does not vary by more than 0.7dB w.r.t. a system trained at that channel condition. The trained system, to an extent, has the ability to generalize when a single input dimension is dropped and for some scenarios it is less than 1dB away from the system trained for that reduced dimension.","PeriodicalId":6708,"journal":{"name":"2019 IEEE International Symposium on Information Theory (ISIT)","volume":"1 1","pages":"1327-1331"},"PeriodicalIF":0.0,"publicationDate":"2019-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84298247","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 : 2019-07-07DOI: 10.1109/ISIT.2019.8849365
Ahmed A. Zewail, A. Yener
This work considers a network consisting of a server and a layer of relay nodes equipped with cache memories which aim to deliver content to end nodes that also have cache memories. The server and the end nodes consider the intermediate relay caches to be untrusted with the content. As a result, the server must design strategies to place content in relay caches not only to serve end users, but also to ensure that any a subset of them, even when colluding, cannot gain any information about the contents of the server database. The end users randomly connect to a subset of these untrusted caches at the beginning of the delivery phase via multicast links. For this network model, a coded caching scheme is developed by jointly optimizing the cache placement and delivery phases using secure regenerating codes. In addition, the scheme is extended to the setup of combination networks with untrusted relays, where the untrusted relays are connected to the end users via unicast links. The study highlights the benefits of cooperating with untrusted caches by designing the end users’ caches to provide multicast opportunities in order to minimize the delivery load.
{"title":"Untrusted Caches in Two-layer Networks","authors":"Ahmed A. Zewail, A. Yener","doi":"10.1109/ISIT.2019.8849365","DOIUrl":"https://doi.org/10.1109/ISIT.2019.8849365","url":null,"abstract":"This work considers a network consisting of a server and a layer of relay nodes equipped with cache memories which aim to deliver content to end nodes that also have cache memories. The server and the end nodes consider the intermediate relay caches to be untrusted with the content. As a result, the server must design strategies to place content in relay caches not only to serve end users, but also to ensure that any a subset of them, even when colluding, cannot gain any information about the contents of the server database. The end users randomly connect to a subset of these untrusted caches at the beginning of the delivery phase via multicast links. For this network model, a coded caching scheme is developed by jointly optimizing the cache placement and delivery phases using secure regenerating codes. In addition, the scheme is extended to the setup of combination networks with untrusted relays, where the untrusted relays are connected to the end users via unicast links. The study highlights the benefits of cooperating with untrusted caches by designing the end users’ caches to provide multicast opportunities in order to minimize the delivery load.","PeriodicalId":6708,"journal":{"name":"2019 IEEE International Symposium on Information Theory (ISIT)","volume":"65 1","pages":"1-5"},"PeriodicalIF":0.0,"publicationDate":"2019-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84581133","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 : 2019-07-07DOI: 10.1109/ISIT.2019.8849536
Tarik Benaddi, Arti D. Yardi, C. Poulliat, I. Andriyanova
We investigate the problem of estimating the maximum a posteriori (MAP) threshold for serially concatenated turbo codes. First, we provide a method to compute this MAP threshold using a numerical approximation of the EBP-GEXIT chart and the Maxwell construction. Second, we explore where the spatially coupled belief propagation (BP) threshold is located with respect to the previously computed MAP threshold and analyze the saturation phenomenon of such schemes. Simulation results indicate that the BP threshold of the spatially coupled turbo-codes saturates to the MAP threshold obtained using the EBP-GEXIT chart.
{"title":"Estimating the Maximum a Posteriori Threshold for Serially Concatenated Turbo Codes","authors":"Tarik Benaddi, Arti D. Yardi, C. Poulliat, I. Andriyanova","doi":"10.1109/ISIT.2019.8849536","DOIUrl":"https://doi.org/10.1109/ISIT.2019.8849536","url":null,"abstract":"We investigate the problem of estimating the maximum a posteriori (MAP) threshold for serially concatenated turbo codes. First, we provide a method to compute this MAP threshold using a numerical approximation of the EBP-GEXIT chart and the Maxwell construction. Second, we explore where the spatially coupled belief propagation (BP) threshold is located with respect to the previously computed MAP threshold and analyze the saturation phenomenon of such schemes. Simulation results indicate that the BP threshold of the spatially coupled turbo-codes saturates to the MAP threshold obtained using the EBP-GEXIT chart.","PeriodicalId":6708,"journal":{"name":"2019 IEEE International Symposium on Information Theory (ISIT)","volume":"5 1","pages":"1347-1351"},"PeriodicalIF":0.0,"publicationDate":"2019-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81740846","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 : 2019-07-07DOI: 10.1109/ISIT.2019.8849517
Yanina Y. Shkel, Rick S. Blum, H. Poor
The framework of secrecy by design is introduced and the fundamental limits of lossless data compression are characterized for this setting. The main idea behind secrecy by design is to begin with an operational secrecy constraint, which is modeled by a secrecy function fs, and then to derive fundamental limits for the performance of the resulting secrecy system. In the setting of lossless compression, it is shown that strong information-theoretic secrecy guarantees can be achieved using a reduced secret key size and a modular two-part coding strategy. Focusing on the non-asymptotic fundamental limits of lossless compression, variable-length lossless compression is studied. It is noted that completely lossless compression is not possible when perfect secrecy is required; however, it becomes meaningful under partial secrecy constraints. Moreover, although it is well known that the traditional fundamental limits of variable-length and almost lossless fixed-length compression are intimately related, this relationship collapses once the secrecy constraint is incorporated.
{"title":"Variable-length compression and secrecy by design","authors":"Yanina Y. Shkel, Rick S. Blum, H. Poor","doi":"10.1109/ISIT.2019.8849517","DOIUrl":"https://doi.org/10.1109/ISIT.2019.8849517","url":null,"abstract":"The framework of secrecy by design is introduced and the fundamental limits of lossless data compression are characterized for this setting. The main idea behind secrecy by design is to begin with an operational secrecy constraint, which is modeled by a secrecy function fs, and then to derive fundamental limits for the performance of the resulting secrecy system. In the setting of lossless compression, it is shown that strong information-theoretic secrecy guarantees can be achieved using a reduced secret key size and a modular two-part coding strategy. Focusing on the non-asymptotic fundamental limits of lossless compression, variable-length lossless compression is studied. It is noted that completely lossless compression is not possible when perfect secrecy is required; however, it becomes meaningful under partial secrecy constraints. Moreover, although it is well known that the traditional fundamental limits of variable-length and almost lossless fixed-length compression are intimately related, this relationship collapses once the secrecy constraint is incorporated.","PeriodicalId":6708,"journal":{"name":"2019 IEEE International Symposium on Information Theory (ISIT)","volume":"11 1","pages":"1532-1536"},"PeriodicalIF":0.0,"publicationDate":"2019-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76431054","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 : 2019-07-07DOI: 10.1109/ISIT.2019.8849697
Rajat Talak, S. Karaman, E. Modiano
Age-of-information (AoI) is a newly proposed performance metric of information freshness. It differs from the traditional delay metric, because it is destination centric and measures the time that elapsed since the last received fresh information update was generated at the source. We show that AoI and packet delay differ in a fundamental way in certain systems, i.e. minimizing one can imply maximizing the other.We consider two queueing systems, namely a single server last come first serve queue with preemptive service (LCFSp) and G/G/∞ queue, and show that a heavy tailed service distribution, that results in the worst case packet delay or variance in packet delay, respectively, minimizes AoI. For the specific case of M/G/1 LCFSp and G/G/∞ queue, we also prove that deterministic service, that minimizes packet delay and variance in packet delay, respectively, results in the worst case AoI.
{"title":"When a Heavy Tailed Service Minimizes Age of Information","authors":"Rajat Talak, S. Karaman, E. Modiano","doi":"10.1109/ISIT.2019.8849697","DOIUrl":"https://doi.org/10.1109/ISIT.2019.8849697","url":null,"abstract":"Age-of-information (AoI) is a newly proposed performance metric of information freshness. It differs from the traditional delay metric, because it is destination centric and measures the time that elapsed since the last received fresh information update was generated at the source. We show that AoI and packet delay differ in a fundamental way in certain systems, i.e. minimizing one can imply maximizing the other.We consider two queueing systems, namely a single server last come first serve queue with preemptive service (LCFSp) and G/G/∞ queue, and show that a heavy tailed service distribution, that results in the worst case packet delay or variance in packet delay, respectively, minimizes AoI. For the specific case of M/G/1 LCFSp and G/G/∞ queue, we also prove that deterministic service, that minimizes packet delay and variance in packet delay, respectively, results in the worst case AoI.","PeriodicalId":6708,"journal":{"name":"2019 IEEE International Symposium on Information Theory (ISIT)","volume":"75 1","pages":"345-349"},"PeriodicalIF":0.0,"publicationDate":"2019-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86372808","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 : 2019-07-07DOI: 10.1109/ISIT.2019.8849816
Serdar Şahin, A. Cipriano, C. Poulliat, M. Boucheret
This paper investigates the dynamic behaviour of doubly iterative bit-interleaved coded modulation (BICM) receivers based on expectation propagation (EP). When implemented in the frequency domain, for single-carrier (SC) systems, such receivers achieve attractive performance-complexity trade-offs in quasi-static wideband channels. With this category of receivers, conventional binary extrinsic information transfer (EXIT) functions are subject to a great number of parameters, including channel realizations, constellation and inner iteration parameters. Hence, this paper proposes a novel extrinsic information evolution analysis method which simplifies the receiver’s EXIT function into independent inner transfer functions. The core idea is to track state-evolution dynamics of EP through numerically stable extrinsic variance/information transfer (EXVIT) functions. Numerical results attest to the accuracy of this method for tracking the asymptotic receiver behaviour.
{"title":"Evolution Analysis of Iterative BICM Receivers with Expectation Propagation over ISI Channels","authors":"Serdar Şahin, A. Cipriano, C. Poulliat, M. Boucheret","doi":"10.1109/ISIT.2019.8849816","DOIUrl":"https://doi.org/10.1109/ISIT.2019.8849816","url":null,"abstract":"This paper investigates the dynamic behaviour of doubly iterative bit-interleaved coded modulation (BICM) receivers based on expectation propagation (EP). When implemented in the frequency domain, for single-carrier (SC) systems, such receivers achieve attractive performance-complexity trade-offs in quasi-static wideband channels. With this category of receivers, conventional binary extrinsic information transfer (EXIT) functions are subject to a great number of parameters, including channel realizations, constellation and inner iteration parameters. Hence, this paper proposes a novel extrinsic information evolution analysis method which simplifies the receiver’s EXIT function into independent inner transfer functions. The core idea is to track state-evolution dynamics of EP through numerically stable extrinsic variance/information transfer (EXVIT) functions. Numerical results attest to the accuracy of this method for tracking the asymptotic receiver behaviour.","PeriodicalId":6708,"journal":{"name":"2019 IEEE International Symposium on Information Theory (ISIT)","volume":"4 1","pages":"166-170"},"PeriodicalIF":0.0,"publicationDate":"2019-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86353145","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 : 2019-07-07DOI: 10.1109/ISIT.2019.8849439
Rémi A. Chou
We propose a model for biometric systems with a multiuser access structure, where after enrollment only predefined authorized sets of participants are allowed to access the system upon presenting their biometrics. Two types of system design are considered for the enrollment. In the first one, the participants must simultaneously present their biometrics to enroll in the system. In the second one, each participant can individually enroll in the system, which is more convenient for systems with a large number of participants. For these two types of enrollment and the presence of a multiuser access structure, the fundamental trade-off between security and privacy leakage is studied.
{"title":"Biometric Systems with Multiuser Access Structures","authors":"Rémi A. Chou","doi":"10.1109/ISIT.2019.8849439","DOIUrl":"https://doi.org/10.1109/ISIT.2019.8849439","url":null,"abstract":"We propose a model for biometric systems with a multiuser access structure, where after enrollment only predefined authorized sets of participants are allowed to access the system upon presenting their biometrics. Two types of system design are considered for the enrollment. In the first one, the participants must simultaneously present their biometrics to enroll in the system. In the second one, each participant can individually enroll in the system, which is more convenient for systems with a large number of participants. For these two types of enrollment and the presence of a multiuser access structure, the fundamental trade-off between security and privacy leakage is studied.","PeriodicalId":6708,"journal":{"name":"2019 IEEE International Symposium on Information Theory (ISIT)","volume":"24 1","pages":"807-811"},"PeriodicalIF":0.0,"publicationDate":"2019-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91545779","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：