Pub Date : 2013-03-28DOI: 10.1109/NCC.2013.6487953
Bhargav Joshi, A. Thangaraj
EXtrinsic Information Transfer (EXIT) chart is a graphical tool for analysis of low density parity check (LDPC) and other codes with iterative decoding. In this paper, we propose the design of LDPC codes for coded modulation schemes by application of linear programming with conditions derived from EXIT charts. Points on the EXIT curve for bit and check node operations are first computed either using analysis or by simulation. The entire EXIT curve is then obtained by linear interpolation. Finally, the EXIT curves are optimized to obtain the maximum possible rate for the code under a given threshold condition. To demonstrate the design procedure, we consider the cases of M-PAM and 8-PSK over the additive white Gaussian noise (AWGN) channel. The optimization method presented is versatile, and can be extended to other constellations and situations easily.
外部信息传递图(EXtrinsic Information Transfer, EXIT)是分析低密度奇偶校验码(LDPC)和其他迭代译码的图形工具。本文利用EXIT图导出的条件，应用线性规划方法设计编码调制方案的LDPC码。位和校验节点操作的EXIT曲线上的点首先通过分析或模拟来计算。然后通过线性插值得到整个EXIT曲线。最后，对EXIT曲线进行了优化，以获得给定阈值条件下代码的最大可能速率。为了演示设计过程，我们考虑了加性高斯白噪声(AWGN)信道上M-PAM和8-PSK的情况。所提出的优化方法通用性强，易于推广到其他星座和情况。
{"title":"EXIT chart based design of LDPC codes for higher order constellations","authors":"Bhargav Joshi, A. Thangaraj","doi":"10.1109/NCC.2013.6487953","DOIUrl":"https://doi.org/10.1109/NCC.2013.6487953","url":null,"abstract":"EXtrinsic Information Transfer (EXIT) chart is a graphical tool for analysis of low density parity check (LDPC) and other codes with iterative decoding. In this paper, we propose the design of LDPC codes for coded modulation schemes by application of linear programming with conditions derived from EXIT charts. Points on the EXIT curve for bit and check node operations are first computed either using analysis or by simulation. The entire EXIT curve is then obtained by linear interpolation. Finally, the EXIT curves are optimized to obtain the maximum possible rate for the code under a given threshold condition. To demonstrate the design procedure, we consider the cases of M-PAM and 8-PSK over the additive white Gaussian noise (AWGN) channel. The optimization method presented is versatile, and can be extended to other constellations and situations easily.","PeriodicalId":202526,"journal":{"name":"2013 National Conference on Communications (NCC)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115025398","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 : 2013-03-28DOI: 10.1109/NCC.2013.6487931
Karthik Ks, B. Ramamurthi
The user equipments (UEs) in fourth-generation cellular networks employ multiple receive antennas for improved performance and reliability. In this scenario, interference rejection combining (IRC) has become a receiver of choice for its desirable properties such as interference mitigation and reduced complexity. Interference covariance matrix (ICM) inversion is a key step in obtaining the combiner weights in such a receiver. In this work, we study the impact of reduced antenna spacing on the post-processing signal-to-interference-plus-noise ratio (SINR) that is achievable in a UE performing IRC. We also investigate the invertibility and condition number of the ICM and its effects on the post-processing SINR. Finally, we study the impact of reduced antenna spacing on the post-processing SINR when there are channel estimation errors.
{"title":"Impact of reduced antenna spacing on the post-processing SINR of interference rejection combining in cellular downlink receivers","authors":"Karthik Ks, B. Ramamurthi","doi":"10.1109/NCC.2013.6487931","DOIUrl":"https://doi.org/10.1109/NCC.2013.6487931","url":null,"abstract":"The user equipments (UEs) in fourth-generation cellular networks employ multiple receive antennas for improved performance and reliability. In this scenario, interference rejection combining (IRC) has become a receiver of choice for its desirable properties such as interference mitigation and reduced complexity. Interference covariance matrix (ICM) inversion is a key step in obtaining the combiner weights in such a receiver. In this work, we study the impact of reduced antenna spacing on the post-processing signal-to-interference-plus-noise ratio (SINR) that is achievable in a UE performing IRC. We also investigate the invertibility and condition number of the ICM and its effects on the post-processing SINR. Finally, we study the impact of reduced antenna spacing on the post-processing SINR when there are channel estimation errors.","PeriodicalId":202526,"journal":{"name":"2013 National Conference on Communications (NCC)","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124451973","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 : 2013-03-28DOI: 10.1109/NCC.2013.6487920
Jeongwoo Han, C. Nguyen
Ultra-wideband (UWB) transmitter and receiver were developed for UWB communication systems. The developed transmitter and receiver are simple, compact and can be realized using planar or uniplanar integrated circuits. Measurement results of the transmitter show multiple monocycle pulses with duration from 0.4–1.2 ns, corresponding approximately to 0.2–3.9 GHz operating frequency range, and 6.5–9 V of peak-to-peak voltage. The developed receiver achieves a conversion loss of 4.5–7.5 dB (without baseband amplifier) and conversion gain from 6.5–9.5 dB (with amplifier) over a 5.5-GHz RF bandwidth, a dynamic range of more than 50 dB and low harmonic distortion in the baseband output signal.
{"title":"Low-cost integrated-circuit transmitter and receiver for UWB communications","authors":"Jeongwoo Han, C. Nguyen","doi":"10.1109/NCC.2013.6487920","DOIUrl":"https://doi.org/10.1109/NCC.2013.6487920","url":null,"abstract":"Ultra-wideband (UWB) transmitter and receiver were developed for UWB communication systems. The developed transmitter and receiver are simple, compact and can be realized using planar or uniplanar integrated circuits. Measurement results of the transmitter show multiple monocycle pulses with duration from 0.4–1.2 ns, corresponding approximately to 0.2–3.9 GHz operating frequency range, and 6.5–9 V of peak-to-peak voltage. The developed receiver achieves a conversion loss of 4.5–7.5 dB (without baseband amplifier) and conversion gain from 6.5–9.5 dB (with amplifier) over a 5.5-GHz RF bandwidth, a dynamic range of more than 50 dB and low harmonic distortion in the baseband output signal.","PeriodicalId":202526,"journal":{"name":"2013 National Conference on Communications (NCC)","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124117844","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 : 2013-03-28DOI: 10.1109/NCC.2013.6487909
B. Biswas, D. R. Poddar, R. Ghatak, A. Karmakar
This paper presents the design of fractal ultra wide band antenna using 3rd iterative modified Sierpinski carpet pattern slots on a circular monopole. Better performance with respect to impedance bandwidth is achieved by truncating the ground plane in steps as well as using fractal slots on the monopole. Further incorporation of the U-shaped slot within ground plane make the structure band notched for the frequency range of 5–6 GHz which is commercially used for WLAN. The proposed antenna shows nearly 117% impedance BW along with stable group delay and radiation characteristics over the entire frequency band.
{"title":"Modified Sierpinski carpet fractal shaped slotted UWB monopole antenna with band notch characteristic","authors":"B. Biswas, D. R. Poddar, R. Ghatak, A. Karmakar","doi":"10.1109/NCC.2013.6487909","DOIUrl":"https://doi.org/10.1109/NCC.2013.6487909","url":null,"abstract":"This paper presents the design of fractal ultra wide band antenna using 3rd iterative modified Sierpinski carpet pattern slots on a circular monopole. Better performance with respect to impedance bandwidth is achieved by truncating the ground plane in steps as well as using fractal slots on the monopole. Further incorporation of the U-shaped slot within ground plane make the structure band notched for the frequency range of 5–6 GHz which is commercially used for WLAN. The proposed antenna shows nearly 117% impedance BW along with stable group delay and radiation characteristics over the entire frequency band.","PeriodicalId":202526,"journal":{"name":"2013 National Conference on Communications (NCC)","volume":"56 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128631318","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 : 2013-03-28DOI: 10.1109/NCC.2013.6488002
A. Kumar, R. Bahl, R. Gupta, H. Choudhary
The performance of Gaussian minimum shift keying (GMSK) modulation scheme for very-low frequency (VLF) communication is evaluated experimentally in terms of the bit error rate. The atmospheric noise in this channel, which is predominantly non-Gaussian, is simulated using the clustering-Poisson model. A data-adaptive scheme is proposed for the suppression of the noise impulses for signal enhancement. The effects of channel coding and signal enhancement are presented, when the channel noise is modeled either as additive white Gaussian noise or as impulsive atmospheric radio noise. It is observed that the coding technique and the signal enhancement improve the performance of the communication system in the presence of the atmospheric radio noise, making it comparable with its performance in the presence of additive white Gaussian noise.
{"title":"Performance enhancement of GMSK and LDPC based VLF communication in atmospheric radio noise","authors":"A. Kumar, R. Bahl, R. Gupta, H. Choudhary","doi":"10.1109/NCC.2013.6488002","DOIUrl":"https://doi.org/10.1109/NCC.2013.6488002","url":null,"abstract":"The performance of Gaussian minimum shift keying (GMSK) modulation scheme for very-low frequency (VLF) communication is evaluated experimentally in terms of the bit error rate. The atmospheric noise in this channel, which is predominantly non-Gaussian, is simulated using the clustering-Poisson model. A data-adaptive scheme is proposed for the suppression of the noise impulses for signal enhancement. The effects of channel coding and signal enhancement are presented, when the channel noise is modeled either as additive white Gaussian noise or as impulsive atmospheric radio noise. It is observed that the coding technique and the signal enhancement improve the performance of the communication system in the presence of the atmospheric radio noise, making it comparable with its performance in the presence of additive white Gaussian noise.","PeriodicalId":202526,"journal":{"name":"2013 National Conference on Communications (NCC)","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125687468","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 : 2013-03-28DOI: 10.1109/NCC.2013.6488026
A. Shankar, D. Bhamare, M. Krishnamoorthy, A. Gumaste
Virtual Machines (VMs) form the central processing entity in data-centers and are key to facilitating cloud computing environments. To make cloud computing a reality in service provider domains, applicability of VMs to metropolitan networks is important. The technology in the metro domain is progressively moving from circuit switched SONET/SDH to packet based Carrier Ethernet. An interesting question that we seek to answer is how does Carrier Ethernet perform for VM migration in data-center and cloud environments. To this end, we perform an extensive simulation study measuring performance of VM migration over both flavors of Carrier Ethernet - namely PBB-TE and MPLS-TP. Our study concludes in the feasibility of Carrier Ethernet as a transport technology in data-centers and clouds.
{"title":"Optimizing transport technology choices for Virtual Machines (VMs)in data-center and cloud environments","authors":"A. Shankar, D. Bhamare, M. Krishnamoorthy, A. Gumaste","doi":"10.1109/NCC.2013.6488026","DOIUrl":"https://doi.org/10.1109/NCC.2013.6488026","url":null,"abstract":"Virtual Machines (VMs) form the central processing entity in data-centers and are key to facilitating cloud computing environments. To make cloud computing a reality in service provider domains, applicability of VMs to metropolitan networks is important. The technology in the metro domain is progressively moving from circuit switched SONET/SDH to packet based Carrier Ethernet. An interesting question that we seek to answer is how does Carrier Ethernet perform for VM migration in data-center and cloud environments. To this end, we perform an extensive simulation study measuring performance of VM migration over both flavors of Carrier Ethernet - namely PBB-TE and MPLS-TP. Our study concludes in the feasibility of Carrier Ethernet as a transport technology in data-centers and clouds.","PeriodicalId":202526,"journal":{"name":"2013 National Conference on Communications (NCC)","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125711131","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 : 2013-03-28DOI: 10.1109/NCC.2013.6487976
R. Gupta, S. Agrawal, S. Behera
In this paper, a compact rectangular dielectric resonator antenna is proposed by using fractal geometries. The Minkowski fractal patch is used on DRA's top to reduce the resonant frequency of the antenna. Numerical results are computed and compared up to three iterations. The fractal iterations offer an additional 19% reduction in the resonant frequency compared to a full size metal top. Switches are proposed at suitable places to achieve frequency reconfigurability. A 43% reduction in the resonant frequency (3.312GHz) is shown when switches are in OFF state compared to a conventional RDRA (5.84GHz) without any increase in antenna size or volume.
{"title":"Design of a compact reconfigurable RDRA","authors":"R. Gupta, S. Agrawal, S. Behera","doi":"10.1109/NCC.2013.6487976","DOIUrl":"https://doi.org/10.1109/NCC.2013.6487976","url":null,"abstract":"In this paper, a compact rectangular dielectric resonator antenna is proposed by using fractal geometries. The Minkowski fractal patch is used on DRA's top to reduce the resonant frequency of the antenna. Numerical results are computed and compared up to three iterations. The fractal iterations offer an additional 19% reduction in the resonant frequency compared to a full size metal top. Switches are proposed at suitable places to achieve frequency reconfigurability. A 43% reduction in the resonant frequency (3.312GHz) is shown when switches are in OFF state compared to a conventional RDRA (5.84GHz) without any increase in antenna size or volume.","PeriodicalId":202526,"journal":{"name":"2013 National Conference on Communications (NCC)","volume":"80 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114941553","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 : 2013-03-28DOI: 10.1109/NCC.2013.6487956
Lava Bhargava, R. Bose, B. M
Binary Low Density Parity Check (LDPC) codes are known to have performance approaching capacity utilization for large block lengths. For short and medium term block lengths, the codes have lower capacity utilization and poorer BER performance due to cycles in the codes. The non-binary LDPC codes have started attracting attention for short and medium length code implementations, which is a requirement for standards like Wi-Fi applications. Current implementations of non-binary LDPC codes focus on serial or partly parallel implementation due to hardware complexity and chip size. We propose a fully parallel implementation for two algorithms. The algorithms are the SPA algorithm with max* function and a sub-optimal form of this called as max implementation. The max implementation has a lower hardware cost and a low performance penalty. The area of sub-optimal max implementation is almost 32% less than that of max implementation. The clock for max is faster by 33%, as a result it has low latency and high throughput as compared to max* algorithm.
{"title":"Novel hardware implementation of LLR-based non-binary LDPC decoders","authors":"Lava Bhargava, R. Bose, B. M","doi":"10.1109/NCC.2013.6487956","DOIUrl":"https://doi.org/10.1109/NCC.2013.6487956","url":null,"abstract":"Binary Low Density Parity Check (LDPC) codes are known to have performance approaching capacity utilization for large block lengths. For short and medium term block lengths, the codes have lower capacity utilization and poorer BER performance due to cycles in the codes. The non-binary LDPC codes have started attracting attention for short and medium length code implementations, which is a requirement for standards like Wi-Fi applications. Current implementations of non-binary LDPC codes focus on serial or partly parallel implementation due to hardware complexity and chip size. We propose a fully parallel implementation for two algorithms. The algorithms are the SPA algorithm with max* function and a sub-optimal form of this called as max implementation. The max implementation has a lower hardware cost and a low performance penalty. The area of sub-optimal max implementation is almost 32% less than that of max implementation. The clock for max is faster by 33%, as a result it has low latency and high throughput as compared to max* algorithm.","PeriodicalId":202526,"journal":{"name":"2013 National Conference on Communications (NCC)","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130407068","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 : 2013-03-28DOI: 10.1109/NCC.2013.6488010
Lalit Kumar Vashishtha, Tanima Dutta, A. Sur
Steganography is a science of hiding messages into multimedia documents. In steganography, there is a technique in which the least significant bit is modified to hide the secret message, known as the least significant bit (LSB) steganography. Several steganalyzers are developed to detect least significant bit (LSB) matching steganography. Least significant bit matching images are still not well detected, especially, at low embedding rate. In this paper, we have improved the least significant bit steganalyzers by analyzing and manipulating the features of some existing least significant bit matching steganalysis techniques. A comprehensive set of experiments is carried out to justify proposed method's applicability and evaluate its performance against the existing least significant bit matching steganalysis techniques.
{"title":"Least significant bit matching steganalysis based on feature analysis","authors":"Lalit Kumar Vashishtha, Tanima Dutta, A. Sur","doi":"10.1109/NCC.2013.6488010","DOIUrl":"https://doi.org/10.1109/NCC.2013.6488010","url":null,"abstract":"Steganography is a science of hiding messages into multimedia documents. In steganography, there is a technique in which the least significant bit is modified to hide the secret message, known as the least significant bit (LSB) steganography. Several steganalyzers are developed to detect least significant bit (LSB) matching steganography. Least significant bit matching images are still not well detected, especially, at low embedding rate. In this paper, we have improved the least significant bit steganalyzers by analyzing and manipulating the features of some existing least significant bit matching steganalysis techniques. A comprehensive set of experiments is carried out to justify proposed method's applicability and evaluate its performance against the existing least significant bit matching steganalysis techniques.","PeriodicalId":202526,"journal":{"name":"2013 National Conference on Communications (NCC)","volume":"81 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128606244","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 : 2013-03-28DOI: 10.1109/NCC.2013.6488022
G. Sekhar, A. Jagannatham
In this paper, we propose optimal power allocation schemes for quality maximization of the transmitted video streams in wireless multicast communication scenarios. For this purpose we employ parametric scalable video models, which model the rate and quality of the scalable streams as a function of the quantization parameter and frame rate. These are derived from the standard JSVM reference codec for the H.264 SVC/AVC and are hence readily applicable in practical scenarios. These models are subsequently employed to present a novel revenue maximization scheme in Orthogonal Frequency Division for Multiple Access (OFDMA) based wireless broadband 4G systems employing transmitted video steam quality based auction bidding models. The framework for optimal power allocation is formulated as a constrained convex optimization problem towards sum video utility maximization. We observe that as the demand for a video stream increases in broadcast/ multicast scenarios, higher power is allocated to the corresponding video stream leading to a gain in the overall revenue/ utility. Simulations illustrate that the proposed optimal power allocation schemes result in a significant performance improvement over the suboptimal equal power allocation schemes for scalable video transmission.
{"title":"Optimal power allocation auction for H.264/SVC coded wireless video transmission","authors":"G. Sekhar, A. Jagannatham","doi":"10.1109/NCC.2013.6488022","DOIUrl":"https://doi.org/10.1109/NCC.2013.6488022","url":null,"abstract":"In this paper, we propose optimal power allocation schemes for quality maximization of the transmitted video streams in wireless multicast communication scenarios. For this purpose we employ parametric scalable video models, which model the rate and quality of the scalable streams as a function of the quantization parameter and frame rate. These are derived from the standard JSVM reference codec for the H.264 SVC/AVC and are hence readily applicable in practical scenarios. These models are subsequently employed to present a novel revenue maximization scheme in Orthogonal Frequency Division for Multiple Access (OFDMA) based wireless broadband 4G systems employing transmitted video steam quality based auction bidding models. The framework for optimal power allocation is formulated as a constrained convex optimization problem towards sum video utility maximization. We observe that as the demand for a video stream increases in broadcast/ multicast scenarios, higher power is allocated to the corresponding video stream leading to a gain in the overall revenue/ utility. Simulations illustrate that the proposed optimal power allocation schemes result in a significant performance improvement over the suboptimal equal power allocation schemes for scalable video transmission.","PeriodicalId":202526,"journal":{"name":"2013 National Conference on Communications (NCC)","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134230479","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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