Pub Date : 2004-11-07DOI: 10.1109/GLOCOM.2005.1577965
Qi Ling, Tongtong Li, Jian Ren
As shown in T. Li et al., (2004) and M. Zhang et al., (2000), the physical layer built-in information privacy of the conventional CDMA system, provided by pseudorandom scrambling, is far from adequate and can be improved by applying cryptographic techniques in the scrambling process. Motivated by the fact that after scrambling, chips spread from one symbol still cluster together and could be fragile to strong burst errors and fading effects, in this paper, a chip-level secure interleaving procedure is proposed to improve the system performance while enhancing the security measure. More specifically, the AES algorithm is combined with block interleaving. It should be noted that interleaving is in fact a special case of scrambling. Security analysis is provided to demonstrate the effectiveness of the proposed secure interleaving scheme under exhaustive search attack. Simulation examples are presented to illustrate the robustness of chip-level interleaving over channels with severe fading or strong burst errors.
T. Li et al.(2004)和M. Zhang et al.(2000)表明，传统CDMA系统由伪随机置乱提供的物理层内置信息隐私远远不够，可以通过在置乱过程中应用加密技术来改进。针对置乱后从一个符号发散出来的芯片仍然会聚集在一起，容易受到强突发错误和衰落影响的问题，本文提出了一种芯片级安全交错处理方法，在提高系统性能的同时增强了安全措施。更具体地说，AES算法与块交错相结合。应该指出的是，交错实际上是置乱的一种特殊情况。安全性分析证明了所提出的安全交错方案在穷举搜索攻击下的有效性。仿真实例说明了芯片级交错在严重衰落或强突发错误信道上的鲁棒性。
{"title":"Physical layer built-in security enhancement of DS-CDMA systems using secure block interleaving","authors":"Qi Ling, Tongtong Li, Jian Ren","doi":"10.1109/GLOCOM.2005.1577965","DOIUrl":"https://doi.org/10.1109/GLOCOM.2005.1577965","url":null,"abstract":"As shown in T. Li et al., (2004) and M. Zhang et al., (2000), the physical layer built-in information privacy of the conventional CDMA system, provided by pseudorandom scrambling, is far from adequate and can be improved by applying cryptographic techniques in the scrambling process. Motivated by the fact that after scrambling, chips spread from one symbol still cluster together and could be fragile to strong burst errors and fading effects, in this paper, a chip-level secure interleaving procedure is proposed to improve the system performance while enhancing the security measure. More specifically, the AES algorithm is combined with block interleaving. It should be noted that interleaving is in fact a special case of scrambling. Security analysis is provided to demonstrate the effectiveness of the proposed secure interleaving scheme under exhaustive search attack. Simulation examples are presented to illustrate the robustness of chip-level interleaving over channels with severe fading or strong burst errors.","PeriodicalId":396779,"journal":{"name":"Conference Record of the Thirty-Eighth Asilomar Conference on Signals, Systems and Computers, 2004.","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123033389","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 : 2004-11-07DOI: 10.1109/ACSSC.2004.1399253
H. Zhang, X. Xia
Vector OFDM was proposed by one of the authors for single-antenna systems as a generalization of OFDM. It converts an ISI channel into multiple "ISI-free" vector channels while involving channel matrices instead of channel coefficients in one-tap equalization. Over multipath fading channels, it benefits from signal space diversity. It either reduces the cyclic prefix data rate overhead or the peak-to-average power ratio. This paper addresses the issue of guard band configuration and provides a solution.
{"title":"A guard band configuration scheme for single-antenna vector OFDM systems","authors":"H. Zhang, X. Xia","doi":"10.1109/ACSSC.2004.1399253","DOIUrl":"https://doi.org/10.1109/ACSSC.2004.1399253","url":null,"abstract":"Vector OFDM was proposed by one of the authors for single-antenna systems as a generalization of OFDM. It converts an ISI channel into multiple \"ISI-free\" vector channels while involving channel matrices instead of channel coefficients in one-tap equalization. Over multipath fading channels, it benefits from signal space diversity. It either reduces the cyclic prefix data rate overhead or the peak-to-average power ratio. This paper addresses the issue of guard band configuration and provides a solution.","PeriodicalId":396779,"journal":{"name":"Conference Record of the Thirty-Eighth Asilomar Conference on Signals, Systems and Computers, 2004.","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123087689","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 : 2004-11-07DOI: 10.1109/ACSSC.2004.1399373
R. Jackson, S. Talwar
Addition of two binary numbers is a fundamental operation in electronic circuits. Applications include arithmetic logic unit, floating-point operations and address generation. It is widely accepted that there is no single best adder implementation. Modern adder architectures utilize a hybrid scheme based on, among others, various parallel prefix, carry select and Ling architectures. The parallel prefix method implements logic functions which determine whether groups of bits will generate or propagate a carry. These functions are hierarchically combined to calculate the carry into any bit. Ling adders reduce delay by using a simplified version of the group generates. However, the method only reduces complexity at the first level; all subsequent combinations in the hierarchy have the same complexity as the parallel prefix method. In this article we present novel architectures, which have reduced complexity at all, levels.
{"title":"High speed binary addition","authors":"R. Jackson, S. Talwar","doi":"10.1109/ACSSC.2004.1399373","DOIUrl":"https://doi.org/10.1109/ACSSC.2004.1399373","url":null,"abstract":"Addition of two binary numbers is a fundamental operation in electronic circuits. Applications include arithmetic logic unit, floating-point operations and address generation. It is widely accepted that there is no single best adder implementation. Modern adder architectures utilize a hybrid scheme based on, among others, various parallel prefix, carry select and Ling architectures. The parallel prefix method implements logic functions which determine whether groups of bits will generate or propagate a carry. These functions are hierarchically combined to calculate the carry into any bit. Ling adders reduce delay by using a simplified version of the group generates. However, the method only reduces complexity at the first level; all subsequent combinations in the hierarchy have the same complexity as the parallel prefix method. In this article we present novel architectures, which have reduced complexity at all, levels.","PeriodicalId":396779,"journal":{"name":"Conference Record of the Thirty-Eighth Asilomar Conference on Signals, Systems and Computers, 2004.","volume":"47 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122336010","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 : 2004-11-07DOI: 10.1109/ACSSC.2004.1399150
Q. Ma, C. Tepedelenlioğlu
With no channel state information (CSI) at the receiver, the highest possible diversity order for multiantenna transmissions over frequency selective channels, is given by the product of the number of transmit and receive antennas and the multipath channel length, the same as the case with perfect CSI at the receiver. In this paper, we consider improved nondiagonal codes for differential space-time-frequency (DSTF) coded orthogonal frequency division multiplexing (OFDM), enabling the maximum spatial and multipath diversity without CSI at the receiver. While full diversity gain can be achieved by using existing differential unitary diagonal codes, we propose a systematic approach to designing nondiagonal codes for DSTF systems, which are block diagonal (BD) and have the necessary unitary and full diversity properties. We investigate not only the diversity product, but also other aspects of the distance spectrum, namely the so-called effective multiplicity in designing BD codes. Based on permutation techniques, we have devised new excellent-performing BD DSTF codes, which improve the coding gain up to 3 dB as compared to their diagonal counterparts.
{"title":"Improved codes for differential space-time-frequency coded OFDM","authors":"Q. Ma, C. Tepedelenlioğlu","doi":"10.1109/ACSSC.2004.1399150","DOIUrl":"https://doi.org/10.1109/ACSSC.2004.1399150","url":null,"abstract":"With no channel state information (CSI) at the receiver, the highest possible diversity order for multiantenna transmissions over frequency selective channels, is given by the product of the number of transmit and receive antennas and the multipath channel length, the same as the case with perfect CSI at the receiver. In this paper, we consider improved nondiagonal codes for differential space-time-frequency (DSTF) coded orthogonal frequency division multiplexing (OFDM), enabling the maximum spatial and multipath diversity without CSI at the receiver. While full diversity gain can be achieved by using existing differential unitary diagonal codes, we propose a systematic approach to designing nondiagonal codes for DSTF systems, which are block diagonal (BD) and have the necessary unitary and full diversity properties. We investigate not only the diversity product, but also other aspects of the distance spectrum, namely the so-called effective multiplicity in designing BD codes. Based on permutation techniques, we have devised new excellent-performing BD DSTF codes, which improve the coding gain up to 3 dB as compared to their diagonal counterparts.","PeriodicalId":396779,"journal":{"name":"Conference Record of the Thirty-Eighth Asilomar Conference on Signals, Systems and Computers, 2004.","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114193512","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 : 2004-11-07DOI: 10.1109/ACSSC.2004.1399204
K. Sivanesan, N. Beaulieu
The outage and BER analysis of maximal ratio combining for bandlimited BPSK systems in microcellular system with cochannel interference is considered. A Nakagami/Rayleigh fading model is assumed. Spectrum raised-cosine and Beaulieu-Tan-Damen pulse shapes are employed. Exact closed-form expressions for outage probability with equal and distinct interferers powers are derived. An average bit error rate expression is derived using Gaussian approximation of the cochannel interference. Monte-Carlo simulation is used to validate the Gaussian approximation. The results are valid for arbitrary diversity order and desired user fading parameter. Slow flat fading, asynchronous timing and independent fading gains are assumed.
{"title":"Precise performance analysis of MRC diversity in microcellular systems with cochannel interference","authors":"K. Sivanesan, N. Beaulieu","doi":"10.1109/ACSSC.2004.1399204","DOIUrl":"https://doi.org/10.1109/ACSSC.2004.1399204","url":null,"abstract":"The outage and BER analysis of maximal ratio combining for bandlimited BPSK systems in microcellular system with cochannel interference is considered. A Nakagami/Rayleigh fading model is assumed. Spectrum raised-cosine and Beaulieu-Tan-Damen pulse shapes are employed. Exact closed-form expressions for outage probability with equal and distinct interferers powers are derived. An average bit error rate expression is derived using Gaussian approximation of the cochannel interference. Monte-Carlo simulation is used to validate the Gaussian approximation. The results are valid for arbitrary diversity order and desired user fading parameter. Slow flat fading, asynchronous timing and independent fading gains are assumed.","PeriodicalId":396779,"journal":{"name":"Conference Record of the Thirty-Eighth Asilomar Conference on Signals, Systems and Computers, 2004.","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114205502","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 : 2004-11-07DOI: 10.1109/ACSSC.2004.1399368
Thibaut Ajdler, I. Kozintsev, R. Lienhart, M. Vetterli
This paper studies the problem of sound source localization in a distributed wireless sensor network formed by mobile general purpose computing and communication devices with audio I/O capabilities. In contrast to well understood localization methods based on dedicated microphone arrays, in our setting sound localization is performed using a sparse array of arbitrary placed sensors (in a typical scenario, localization is performed by several laptops/PDAs co-located in a room). Therefore any far-field assumptions are no longer valid in this situation. Additionally, localization algorithm's performance is affected by uncertainties in sensor position and errors in A/D synchronization. The proposed source localization algorithm consists of two steps. In the first step, time differences of arrivals (TDOAs) are estimated for the microphone pairs, and in the second step the maximum likelihood (ML) estimation for the source position is performed. We evaluate the Cramer-Rao bound (CRB) on the variance of the location estimation and compare it with simulations and experimental results. We also discuss the effects of distributed array geometry and errors in sensor positions on the performance of the localization algorithm. The performances of the system are likely to be limited by errors in sensor locations and increase when the microphones have a large aperture with respect to the source.
{"title":"Acoustic source localization in distributed sensor networks","authors":"Thibaut Ajdler, I. Kozintsev, R. Lienhart, M. Vetterli","doi":"10.1109/ACSSC.2004.1399368","DOIUrl":"https://doi.org/10.1109/ACSSC.2004.1399368","url":null,"abstract":"This paper studies the problem of sound source localization in a distributed wireless sensor network formed by mobile general purpose computing and communication devices with audio I/O capabilities. In contrast to well understood localization methods based on dedicated microphone arrays, in our setting sound localization is performed using a sparse array of arbitrary placed sensors (in a typical scenario, localization is performed by several laptops/PDAs co-located in a room). Therefore any far-field assumptions are no longer valid in this situation. Additionally, localization algorithm's performance is affected by uncertainties in sensor position and errors in A/D synchronization. The proposed source localization algorithm consists of two steps. In the first step, time differences of arrivals (TDOAs) are estimated for the microphone pairs, and in the second step the maximum likelihood (ML) estimation for the source position is performed. We evaluate the Cramer-Rao bound (CRB) on the variance of the location estimation and compare it with simulations and experimental results. We also discuss the effects of distributed array geometry and errors in sensor positions on the performance of the localization algorithm. The performances of the system are likely to be limited by errors in sensor locations and increase when the microphones have a large aperture with respect to the source.","PeriodicalId":396779,"journal":{"name":"Conference Record of the Thirty-Eighth Asilomar Conference on Signals, Systems and Computers, 2004.","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114240187","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 : 2004-11-07DOI: 10.1109/ACSSC.2004.1399565
Hussam Mustafa, Miloš Doroslova
We propose four features to classify amplitude shift keying with two levels and four levels, binary phase shift keying, quadrature phase keying, frequency shift keying with two carriers and four carriers. After that we present a new method of classification based on support vector machine (SVM) that uses the four proposed features. We study the performance of SVM classifier and compare it to the previous work done in the literature on the digital modulation classification problem.
{"title":"Digital modulation recognition using support vector machine classifier","authors":"Hussam Mustafa, Miloš Doroslova","doi":"10.1109/ACSSC.2004.1399565","DOIUrl":"https://doi.org/10.1109/ACSSC.2004.1399565","url":null,"abstract":"We propose four features to classify amplitude shift keying with two levels and four levels, binary phase shift keying, quadrature phase keying, frequency shift keying with two carriers and four carriers. After that we present a new method of classification based on support vector machine (SVM) that uses the four proposed features. We study the performance of SVM classifier and compare it to the previous work done in the literature on the digital modulation classification problem.","PeriodicalId":396779,"journal":{"name":"Conference Record of the Thirty-Eighth Asilomar Conference on Signals, Systems and Computers, 2004.","volume":"151 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116093140","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 : 2004-11-07DOI: 10.1109/ACSSC.2004.1399546
Zhanlue Zhao, X.R. Li
In parameter estimation and filtering, model approximation is quite common in engineering research and development. These approximations distort the original relation between the parameter of interest and the observation and cause the performance deterioration. It is crucial to have a measure to appraise these approximations. In this paper, we analyze the structure of the parameter inference and clarify its ingrained vagueness. Accordingly, we apprehend the commensuration between the model distortion and the difference between two probability density functions. We work out a distortion measure, and it turns out that the Kullback-Leibler (K-L) divergence can serve this purpose. We apply the K-L divergence as a distortion measure to model set design for multiple model estimation. We demonstrate that the K-L divergence is a measure of significance for estimation performance deterioration, and has high potential for the development of highly adaptive algorithms.
{"title":"Probabilistic model distortion measure and its application to model-set design of multiple model approach","authors":"Zhanlue Zhao, X.R. Li","doi":"10.1109/ACSSC.2004.1399546","DOIUrl":"https://doi.org/10.1109/ACSSC.2004.1399546","url":null,"abstract":"In parameter estimation and filtering, model approximation is quite common in engineering research and development. These approximations distort the original relation between the parameter of interest and the observation and cause the performance deterioration. It is crucial to have a measure to appraise these approximations. In this paper, we analyze the structure of the parameter inference and clarify its ingrained vagueness. Accordingly, we apprehend the commensuration between the model distortion and the difference between two probability density functions. We work out a distortion measure, and it turns out that the Kullback-Leibler (K-L) divergence can serve this purpose. We apply the K-L divergence as a distortion measure to model set design for multiple model estimation. We demonstrate that the K-L divergence is a measure of significance for estimation performance deterioration, and has high potential for the development of highly adaptive algorithms.","PeriodicalId":396779,"journal":{"name":"Conference Record of the Thirty-Eighth Asilomar Conference on Signals, Systems and Computers, 2004.","volume":"87 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121170774","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 : 2004-11-07DOI: 10.1109/ACSSC.2004.1399454
S. Kamath, J. Jackson
Motion JPEG (MJPEG) can be simply defined as a compression scheme in which each frame in a video sequence is JPEG compressed. This method though simple and intuitive has the disadvantages of high bandwidth requirements for transmission and low resilience to errors due to missing frames. In this paper, we present a modification to the MJPEG compression called MJPEG with differential pulse code modulation (MJPEG-DPCM) where differential encoding between coefficients of adjacent frames is carried out The modification provides higher compression, maintains perceptual visual quality and reduces video degradation due to missing frames or missing packets.
{"title":"Low-bit rate motion JPEG using differential encoding","authors":"S. Kamath, J. Jackson","doi":"10.1109/ACSSC.2004.1399454","DOIUrl":"https://doi.org/10.1109/ACSSC.2004.1399454","url":null,"abstract":"Motion JPEG (MJPEG) can be simply defined as a compression scheme in which each frame in a video sequence is JPEG compressed. This method though simple and intuitive has the disadvantages of high bandwidth requirements for transmission and low resilience to errors due to missing frames. In this paper, we present a modification to the MJPEG compression called MJPEG with differential pulse code modulation (MJPEG-DPCM) where differential encoding between coefficients of adjacent frames is carried out The modification provides higher compression, maintains perceptual visual quality and reduces video degradation due to missing frames or missing packets.","PeriodicalId":396779,"journal":{"name":"Conference Record of the Thirty-Eighth Asilomar Conference on Signals, Systems and Computers, 2004.","volume":"40 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116657523","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 : 2004-11-07DOI: 10.1109/ACSSC.2004.1399291
Y. Levinbook, T. Wong
In this paper, we construct the maximum likelihood (ML) estimator of diffusive source location based on binary observations. We utilize two different estimation approaches, ML estimation based on all the observations (i.e.. batch processing) and approximated ML estimation using only new observations and the previous estimate (i.e., real time processing). The performance of these estimators are compared with theoretical bounds and are shown to achieve excellent performance.
{"title":"Maximum likelihood diffusive source localization based on binary observations","authors":"Y. Levinbook, T. Wong","doi":"10.1109/ACSSC.2004.1399291","DOIUrl":"https://doi.org/10.1109/ACSSC.2004.1399291","url":null,"abstract":"In this paper, we construct the maximum likelihood (ML) estimator of diffusive source location based on binary observations. We utilize two different estimation approaches, ML estimation based on all the observations (i.e.. batch processing) and approximated ML estimation using only new observations and the previous estimate (i.e., real time processing). The performance of these estimators are compared with theoretical bounds and are shown to achieve excellent performance.","PeriodicalId":396779,"journal":{"name":"Conference Record of the Thirty-Eighth Asilomar Conference on Signals, Systems and Computers, 2004.","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125620592","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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