Pub Date : 2008-09-01DOI: 10.1109/ALLERTON.2008.4797566
L. Lai, Siu-Wai Ho, H. Poor
Biometric security systems are studied from an information theoretic perspective. A fundamental tradeoff between privacy, measured by the normalized equivocation rate of the biometric measurements, and security, measured by the rate of the key generated from the biometric measurements, is identified. The scenario in which a potential attacker does not have side information is considered first. The privacy-security region, which characterizes the above-noted tradeoff, is derived for this case. The close relationship between common information among random variables and the biometric security system is also revealed. The scenario in which the attacker has side information is then considered. Inner and outer bounds on the privacy-security region are derived in this case.
{"title":"Privacy-security tradeoffs in biometric security systems","authors":"L. Lai, Siu-Wai Ho, H. Poor","doi":"10.1109/ALLERTON.2008.4797566","DOIUrl":"https://doi.org/10.1109/ALLERTON.2008.4797566","url":null,"abstract":"Biometric security systems are studied from an information theoretic perspective. A fundamental tradeoff between privacy, measured by the normalized equivocation rate of the biometric measurements, and security, measured by the rate of the key generated from the biometric measurements, is identified. The scenario in which a potential attacker does not have side information is considered first. The privacy-security region, which characterizes the above-noted tradeoff, is derived for this case. The close relationship between common information among random variables and the biometric security system is also revealed. The scenario in which the attacker has side information is then considered. Inner and outer bounds on the privacy-security region are derived in this case.","PeriodicalId":120561,"journal":{"name":"2008 46th Annual Allerton Conference on Communication, Control, and Computing","volume":"50 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116244640","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/ALLERTON.2008.4797732
Aditya Mahajan, A. Nayyar, D. Teneketzis
Sequential decomposition of two general models of decentralized systems with non-classical information structures is presented. In model A, all agents have two observations at each step: a common observation that all agents observe and a private observation of their own. The control actions of each agent is based on all past common observations, the current private observation and the contents of its memory. At each step, each agent also updates the contents of its memory. A cost function, which depends on the state of the plant and the control actions of all agents, is given. The objective is to choose control and memory update functions for all agents to either minimize a total expected cost over a finite horizon or to minimize a discounted cost over an infinite horizon. In model B, the agents do not have any common observation, the rest is same as in model A. The key idea of our solution methodology is the following. From the point of view of a fictitious agent that observes all common observations, the system can be viewed as a centralized system with partial observations. This allows us to identify information states and obtain a sequential decomposition. When the system variables take values in finite sets, the optimality equations of the sequential decomposition are similar to those of partially observable Markov decision processes (POMDP) with finite state and action spaces. For such systems, we can use algorithms for POMDPs to compute optimal designs for models A and B.
{"title":"Identifying tractable decentralized control problems on the basis of information structure","authors":"Aditya Mahajan, A. Nayyar, D. Teneketzis","doi":"10.1109/ALLERTON.2008.4797732","DOIUrl":"https://doi.org/10.1109/ALLERTON.2008.4797732","url":null,"abstract":"Sequential decomposition of two general models of decentralized systems with non-classical information structures is presented. In model A, all agents have two observations at each step: a common observation that all agents observe and a private observation of their own. The control actions of each agent is based on all past common observations, the current private observation and the contents of its memory. At each step, each agent also updates the contents of its memory. A cost function, which depends on the state of the plant and the control actions of all agents, is given. The objective is to choose control and memory update functions for all agents to either minimize a total expected cost over a finite horizon or to minimize a discounted cost over an infinite horizon. In model B, the agents do not have any common observation, the rest is same as in model A. The key idea of our solution methodology is the following. From the point of view of a fictitious agent that observes all common observations, the system can be viewed as a centralized system with partial observations. This allows us to identify information states and obtain a sequential decomposition. When the system variables take values in finite sets, the optimality equations of the sequential decomposition are similar to those of partially observable Markov decision processes (POMDP) with finite state and action spaces. For such systems, we can use algorithms for POMDPs to compute optimal designs for models A and B.","PeriodicalId":120561,"journal":{"name":"2008 46th Annual Allerton Conference on Communication, Control, and Computing","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115295093","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/ALLERTON.2008.4797531
S. Pawar, A. Avestimehr, David Tse
We show that the diversity-multiplexing tradeoff of a half-duplex single-relay channel with identically distributed Rayleigh fading channel gains meets the 2 by 1 MISO bound. We generalize the result to the case when there are N non-interfering relays and show that the diversity-multiplexing tradeoff is equal to the N + 1 by 1 MISO bound.
{"title":"Diversity-multiplexing tradeoff of the half-duplex relay channel","authors":"S. Pawar, A. Avestimehr, David Tse","doi":"10.1109/ALLERTON.2008.4797531","DOIUrl":"https://doi.org/10.1109/ALLERTON.2008.4797531","url":null,"abstract":"We show that the diversity-multiplexing tradeoff of a half-duplex single-relay channel with identically distributed Rayleigh fading channel gains meets the 2 by 1 MISO bound. We generalize the result to the case when there are N non-interfering relays and show that the diversity-multiplexing tradeoff is equal to the N + 1 by 1 MISO bound.","PeriodicalId":120561,"journal":{"name":"2008 46th Annual Allerton Conference on Communication, Control, and Computing","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115456488","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/ALLERTON.2008.4797653
R. T. Krishnamachari, M. Varanasi
Volume estimates of geodesic balls in Riemannian manifolds find many applications in coding and information theory. This paper computes the precise power series expansion of volume of small geodesic balls in a complex Stiefel manifold of arbitrary dimension. The volume result is employed to bound the minimum distance of codes over the manifold. An asymptotically tight characterization of the rate-distortion tradeoff for sources uniformly distributed over the surface is also provided.
{"title":"Volume of geodesic balls in the complex Stiefel manifold","authors":"R. T. Krishnamachari, M. Varanasi","doi":"10.1109/ALLERTON.2008.4797653","DOIUrl":"https://doi.org/10.1109/ALLERTON.2008.4797653","url":null,"abstract":"Volume estimates of geodesic balls in Riemannian manifolds find many applications in coding and information theory. This paper computes the precise power series expansion of volume of small geodesic balls in a complex Stiefel manifold of arbitrary dimension. The volume result is employed to bound the minimum distance of codes over the manifold. An asymptotically tight characterization of the rate-distortion tradeoff for sources uniformly distributed over the surface is also provided.","PeriodicalId":120561,"journal":{"name":"2008 46th Annual Allerton Conference on Communication, Control, and Computing","volume":"103 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121429764","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/ALLERTON.2008.4797583
S. Sanghavi, D. Malioutov, A. Willsky
This paper investigates the performance of belief propagation (BP) as a distributed solution to two combinatorial resource allocation problems arising in sensor networks: network formation and fusion center location. We model these problems by max-weight b-matching and uncapacitated facility location, respectively. Each of these is a classical optimization problem. For both problems, we (a) show how BP can be simplified for implementation in distributed environments where transmissions are broadcast and can interfere, (b) derive a principled interpretation of estimates before convergence, and (c) compare the performance of BP to that of linear programming.
{"title":"Networking sensors using belief propagation","authors":"S. Sanghavi, D. Malioutov, A. Willsky","doi":"10.1109/ALLERTON.2008.4797583","DOIUrl":"https://doi.org/10.1109/ALLERTON.2008.4797583","url":null,"abstract":"This paper investigates the performance of belief propagation (BP) as a distributed solution to two combinatorial resource allocation problems arising in sensor networks: network formation and fusion center location. We model these problems by max-weight b-matching and uncapacitated facility location, respectively. Each of these is a classical optimization problem. For both problems, we (a) show how BP can be simplified for implementation in distributed environments where transmissions are broadcast and can interfere, (b) derive a principled interpretation of estimates before convergence, and (c) compare the performance of BP to that of linear programming.","PeriodicalId":120561,"journal":{"name":"2008 46th Annual Allerton Conference on Communication, Control, and Computing","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123518513","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/ALLERTON.2008.4797572
Jun Zhang, J. Andrews, R. Heath
This paper considers fundamental limits on adaptive multiple-input multiple-output (MIMO) transmission with imperfect channel state information at the transmitter (CSIT). First, the achievable ergodic rates are derived for both single-user and multi-user MIMO systems with different CSIT assumptions, which shows that single-user MIMO is robust to imperfect CSIT while multiuser MIMO loses spatial multiplexing gain in proportion to delay and inverse with channel quantization codebook size. A single-user/multiuser mode switching rule is then proposed based on the average SNR, the amount of delay, and the quantization codebook size. The operating regions for single-user and multiuser modes are determined, which can be used to select the preferred mode. It is shown that the multiuser mode should not be activated when the delay is large or the codebook size is small.
{"title":"Single-user MIMO vs. Multiuser MIMO in the broadcast channel with CSIT constraints","authors":"Jun Zhang, J. Andrews, R. Heath","doi":"10.1109/ALLERTON.2008.4797572","DOIUrl":"https://doi.org/10.1109/ALLERTON.2008.4797572","url":null,"abstract":"This paper considers fundamental limits on adaptive multiple-input multiple-output (MIMO) transmission with imperfect channel state information at the transmitter (CSIT). First, the achievable ergodic rates are derived for both single-user and multi-user MIMO systems with different CSIT assumptions, which shows that single-user MIMO is robust to imperfect CSIT while multiuser MIMO loses spatial multiplexing gain in proportion to delay and inverse with channel quantization codebook size. A single-user/multiuser mode switching rule is then proposed based on the average SNR, the amount of delay, and the quantization codebook size. The operating regions for single-user and multiuser modes are determined, which can be used to select the preferred mode. It is shown that the multiuser mode should not be activated when the delay is large or the codebook size is small.","PeriodicalId":120561,"journal":{"name":"2008 46th Annual Allerton Conference on Communication, Control, and Computing","volume":"7 3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123686047","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/ALLERTON.2008.4797601
K. Jagannathan, E. Modiano, Lizhong Zheng
In this paper, we consider a single-server queue with Poisson inputs and two distinct service rates. The service rate employed at any given instant is decided by a resource allocation policy, based on the queue occupancy. We deal with the question of how often control information needs to be sent to the rate scheduler so as to stay below a certain probability of congestion. We first consider some simple Markovian service rate allocation policies and derive the corresponding control rate vs. congestion probability tradeoffs in closed form. However, since a closed form solution is not possible for more general Markov policies, we resort to large deviation tools to characterize the congestion probabilities of various control policies. We also identify a simple dasiatwo-thresholdpsila policy which achieves the best possible tradeoff between rate of control and the decay exponent of the congestion probability. Finally, we also investigate the impact of control errors on the congestion probability of a resource allocation policy.
{"title":"Effective resource allocation in a queue: How much control is necessary?","authors":"K. Jagannathan, E. Modiano, Lizhong Zheng","doi":"10.1109/ALLERTON.2008.4797601","DOIUrl":"https://doi.org/10.1109/ALLERTON.2008.4797601","url":null,"abstract":"In this paper, we consider a single-server queue with Poisson inputs and two distinct service rates. The service rate employed at any given instant is decided by a resource allocation policy, based on the queue occupancy. We deal with the question of how often control information needs to be sent to the rate scheduler so as to stay below a certain probability of congestion. We first consider some simple Markovian service rate allocation policies and derive the corresponding control rate vs. congestion probability tradeoffs in closed form. However, since a closed form solution is not possible for more general Markov policies, we resort to large deviation tools to characterize the congestion probabilities of various control policies. We also identify a simple dasiatwo-thresholdpsila policy which achieves the best possible tradeoff between rate of control and the decay exponent of the congestion probability. Finally, we also investigate the impact of control errors on the congestion probability of a resource allocation policy.","PeriodicalId":120561,"journal":{"name":"2008 46th Annual Allerton Conference on Communication, Control, and Computing","volume":"52 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121770079","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/ALLERTON.2008.4797664
D.N. Liu, M. Fitz
Data detection of coded multiple-input multipleoutput (MIMO) orthogonal frequency division multiplexing (OFDM) in fast time-varying channels are considered. Maintaining high performance with manageable complexity relies on iterative soft-in soft-out equalization and decoding. This paper derives the optimum front-end demodulation structure by extending Ungerboeck equalizer formulation to a MIMO intercarrier interference (ICI) channel. Utilizing the fact that ICI energy is clustered in adjacent subcarriers, frequency domain equalization is made localized. This paper further proposes a computational efficient linear minimum mean square error (LMMSE) based equalization method: recursive sliding-window (SW) SIC-LMMSE equalizer. Simulation results are reported for the iterative receivers with application to the mobile worldwide interoperability for microwave access (WiMAX).
{"title":"Turbo MIMO equalization and decoding in fast fading mobile coded OFDM","authors":"D.N. Liu, M. Fitz","doi":"10.1109/ALLERTON.2008.4797664","DOIUrl":"https://doi.org/10.1109/ALLERTON.2008.4797664","url":null,"abstract":"Data detection of coded multiple-input multipleoutput (MIMO) orthogonal frequency division multiplexing (OFDM) in fast time-varying channels are considered. Maintaining high performance with manageable complexity relies on iterative soft-in soft-out equalization and decoding. This paper derives the optimum front-end demodulation structure by extending Ungerboeck equalizer formulation to a MIMO intercarrier interference (ICI) channel. Utilizing the fact that ICI energy is clustered in adjacent subcarriers, frequency domain equalization is made localized. This paper further proposes a computational efficient linear minimum mean square error (LMMSE) based equalization method: recursive sliding-window (SW) SIC-LMMSE equalizer. Simulation results are reported for the iterative receivers with application to the mobile worldwide interoperability for microwave access (WiMAX).","PeriodicalId":120561,"journal":{"name":"2008 46th Annual Allerton Conference on Communication, Control, and Computing","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128177383","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/ALLERTON.2008.4797628
I-Hsiang Wang, David Tse
Gaussian interference channels with multiple receive antennas are studied. First we investigate the two-user Gaussian interference channel with two receive antennas, and it turns out that the angles among channel vectors play a central role in how the additional antenna helps increase the capacity. We formulate the notion of generalized degrees of freedom and show that optimal g.d.o.f. is achieved by superposition Gaussian random coding. Remarkably, the operating regime for the best linear scheme (MMSE followed by treating interference as noise) achieves optimal g.d.o.f. is enlarged when angle is large. Second, a three-to-one Gaussian interference channel in which the interfered receiver has two receive antennas is studied. Unlike the single-antenna case, the idea of interference alignment on signal scales is not directly applicable, and a natural generalization of Han-Kobayashi-type scheme with Gaussian random codes can achieve the capacity region within a number of bits, which depends only on the angle between two interfering channel vectors. We use the notion of generalized degrees of freedom to analyze the problem, and it turns out the HK-type scheme is not g.d.o.f.-optimal. We propose a new scheme, partial interference alignment, which well exploits both the receiver joint processing gain and interference alignment structural gain, and it outperforms HK-type scheme and single-antenna interference alignment scheme.
{"title":"Gaussian interference channels with multiple receive antennas: Capacity and generalized degrees of freedom","authors":"I-Hsiang Wang, David Tse","doi":"10.1109/ALLERTON.2008.4797628","DOIUrl":"https://doi.org/10.1109/ALLERTON.2008.4797628","url":null,"abstract":"Gaussian interference channels with multiple receive antennas are studied. First we investigate the two-user Gaussian interference channel with two receive antennas, and it turns out that the angles among channel vectors play a central role in how the additional antenna helps increase the capacity. We formulate the notion of generalized degrees of freedom and show that optimal g.d.o.f. is achieved by superposition Gaussian random coding. Remarkably, the operating regime for the best linear scheme (MMSE followed by treating interference as noise) achieves optimal g.d.o.f. is enlarged when angle is large. Second, a three-to-one Gaussian interference channel in which the interfered receiver has two receive antennas is studied. Unlike the single-antenna case, the idea of interference alignment on signal scales is not directly applicable, and a natural generalization of Han-Kobayashi-type scheme with Gaussian random codes can achieve the capacity region within a number of bits, which depends only on the angle between two interfering channel vectors. We use the notion of generalized degrees of freedom to analyze the problem, and it turns out the HK-type scheme is not g.d.o.f.-optimal. We propose a new scheme, partial interference alignment, which well exploits both the receiver joint processing gain and interference alignment structural gain, and it outperforms HK-type scheme and single-antenna interference alignment scheme.","PeriodicalId":120561,"journal":{"name":"2008 46th Annual Allerton Conference on Communication, Control, and Computing","volume":"90 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128633229","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/ALLERTON.2008.4797683
Yuhong Guo, Dale Schuurmans
We present an efficient global optimization algorithm for exponential family principal component analysis (PCA) and associated low-rank matrix factorization problems. Exponential family PCA has been shown to improve the results of standard PCA on non-Gaussian data. Unfortunately, the widespread use of exponential family PCA has been hampered by the existence of only local optimization procedures. The prevailing assumption has been that the non-convexity of the problem prevents an efficient global optimization approach from being developed. Fortunately, this pessimism is unfounded. We present a reformulation of the underlying optimization problem that preserves the identity of the global solution while admitting an efficient optimization procedure. The algorithm we develop involves only a sub-gradient optimization of a convex objective plus associated eigenvector computations. (No general purpose semidefinite programming solver is required.) The low-rank constraint is exactly preserved, while the method can be kernelized through a consistent approximation to admit a fixed non-linearity. We demonstrate improved solution quality with the global solver, and also add to the evidence that exponential family PCA produces superior results to standard PCA on non-Gaussian data.
{"title":"Efficient global optimization for exponential family PCA and low-rank matrix factorization","authors":"Yuhong Guo, Dale Schuurmans","doi":"10.1109/ALLERTON.2008.4797683","DOIUrl":"https://doi.org/10.1109/ALLERTON.2008.4797683","url":null,"abstract":"We present an efficient global optimization algorithm for exponential family principal component analysis (PCA) and associated low-rank matrix factorization problems. Exponential family PCA has been shown to improve the results of standard PCA on non-Gaussian data. Unfortunately, the widespread use of exponential family PCA has been hampered by the existence of only local optimization procedures. The prevailing assumption has been that the non-convexity of the problem prevents an efficient global optimization approach from being developed. Fortunately, this pessimism is unfounded. We present a reformulation of the underlying optimization problem that preserves the identity of the global solution while admitting an efficient optimization procedure. The algorithm we develop involves only a sub-gradient optimization of a convex objective plus associated eigenvector computations. (No general purpose semidefinite programming solver is required.) The low-rank constraint is exactly preserved, while the method can be kernelized through a consistent approximation to admit a fixed non-linearity. We demonstrate improved solution quality with the global solver, and also add to the evidence that exponential family PCA produces superior results to standard PCA on non-Gaussian data.","PeriodicalId":120561,"journal":{"name":"2008 46th Annual Allerton Conference on Communication, Control, and Computing","volume":"134 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128559113","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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