Pub Date : 2018-05-27DOI: 10.1109/ISCAS.2018.8351796
A. Massa, M. Bertolli, G. Gottardi, A. Hannan, D. Marcantonio, G. Oliveri, A. Polo, F. Robol, P. Rocca, F. Viani
Compressive sensing (CS) is currently one the most active research field in information engineering and science. The CS features/properties (e.g., its flexibility, robustness, accuracy, and effectiveness) and the strong theoretical background have motivated a great interest in developing and applying CS to many domains including antenna arrays. Indeed, several problems arising in such a framework can be directly formulated or suitably recast for an effective solution within the CS environment. This work is aimed at presenting a review of the current and most recent advances of CS formulations for antenna arrays developed at the ELEDIA research center. Towards this end, a set of representative applicative scenarios are illustrated ranging from the diagnosis and synthesis of antenna arrays up to antenna array processing including the estimation of directions-of-arrival. Current challenges and trends in the application of CS to the solution of traditional and/or innovative antenna array problems are discussed, as well.
{"title":"Compressive Sensing as Applied to Antenna Arrays: Synthesis, Diagnosis, and Processing","authors":"A. Massa, M. Bertolli, G. Gottardi, A. Hannan, D. Marcantonio, G. Oliveri, A. Polo, F. Robol, P. Rocca, F. Viani","doi":"10.1109/ISCAS.2018.8351796","DOIUrl":"https://doi.org/10.1109/ISCAS.2018.8351796","url":null,"abstract":"Compressive sensing (CS) is currently one the most active research field in information engineering and science. The CS features/properties (e.g., its flexibility, robustness, accuracy, and effectiveness) and the strong theoretical background have motivated a great interest in developing and applying CS to many domains including antenna arrays. Indeed, several problems arising in such a framework can be directly formulated or suitably recast for an effective solution within the CS environment. This work is aimed at presenting a review of the current and most recent advances of CS formulations for antenna arrays developed at the ELEDIA research center. Towards this end, a set of representative applicative scenarios are illustrated ranging from the diagnosis and synthesis of antenna arrays up to antenna array processing including the estimation of directions-of-arrival. Current challenges and trends in the application of CS to the solution of traditional and/or innovative antenna array problems are discussed, as well.","PeriodicalId":6569,"journal":{"name":"2018 IEEE International Symposium on Circuits and Systems (ISCAS)","volume":"7 1","pages":"1-5"},"PeriodicalIF":0.0,"publicationDate":"2018-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84123649","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 : 2018-05-27DOI: 10.1109/ISCAS.2018.8351219
Soon-Jae Kweon, Sung-Hun Jo, Ji-Hoon Suh, M. Je, Hyung-Joun Yoo
We propose a sinusoidal signal generator (SSG) using a constant gain finite impulse response (FIR) filter for measuring impedance spectrum from 1-kHz to 2.048-MHz range. A simple digital-to-analog converter (DAC) using eight unit resistors generates differential stepwise signals and the FIR filter attenuates close-in harmonics of the stepwise signals using its inherent nulls. A continuous-time (CT) low-pass filter (LPF) attenuates high-order harmonics of the FIR filter's output. The fabricated SSG achieved the total harmonic distortion less than 0.2% up to 10th harmonic using a simple DAC and low oversampling ratio of 8. Since our SSG adopts a passive type of CT LPF and a constant gain FIR filter which does not require any gain compensation circuit, the fabricated SSG consumed 5.1 mW which is about 30% of our previous SSG.
{"title":"A Sinusoidal Signal Generator Using a Constant Gain Finite Impulse Response (FIR) Filter for Electrical Bioimpedance Spectroscopy","authors":"Soon-Jae Kweon, Sung-Hun Jo, Ji-Hoon Suh, M. Je, Hyung-Joun Yoo","doi":"10.1109/ISCAS.2018.8351219","DOIUrl":"https://doi.org/10.1109/ISCAS.2018.8351219","url":null,"abstract":"We propose a sinusoidal signal generator (SSG) using a constant gain finite impulse response (FIR) filter for measuring impedance spectrum from 1-kHz to 2.048-MHz range. A simple digital-to-analog converter (DAC) using eight unit resistors generates differential stepwise signals and the FIR filter attenuates close-in harmonics of the stepwise signals using its inherent nulls. A continuous-time (CT) low-pass filter (LPF) attenuates high-order harmonics of the FIR filter's output. The fabricated SSG achieved the total harmonic distortion less than 0.2% up to 10th harmonic using a simple DAC and low oversampling ratio of 8. Since our SSG adopts a passive type of CT LPF and a constant gain FIR filter which does not require any gain compensation circuit, the fabricated SSG consumed 5.1 mW which is about 30% of our previous SSG.","PeriodicalId":6569,"journal":{"name":"2018 IEEE International Symposium on Circuits and Systems (ISCAS)","volume":"30 1","pages":"1-5"},"PeriodicalIF":0.0,"publicationDate":"2018-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84671425","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 : 2018-05-27DOI: 10.1109/ISCAS.2018.8351424
Tahmid Ahmed, K. B. Mirza, K. Nikolic
A necessary requirement for chemometric platforms is pre-processing of the acquired chemical signals to remove baseline drift in the signal. The drift could originate from sensor characteristics or from background chemical activity in the surrounding environment. A recent emerging field is neurochemical monitoring to detect and quantify neural activity. In this paper, a resource efficient pre-processing system is presented to remove drift from the acquired neurochemical signal. The drift removal technique is based on baseline manipulation without requiring window based processing. The target application, for demonstration purposes, is the recording of vagal pH signals to enable closed-loop Vagus Nerve Stimulation (VNS). The final design is multiplier-free and results in an Application Specific Integrated Circuit (ASIC) that is 640 μm by 625 μm in area.
{"title":"Resource Efficient Pre-processor for Drift Removal in Neurochemical Signals","authors":"Tahmid Ahmed, K. B. Mirza, K. Nikolic","doi":"10.1109/ISCAS.2018.8351424","DOIUrl":"https://doi.org/10.1109/ISCAS.2018.8351424","url":null,"abstract":"A necessary requirement for chemometric platforms is pre-processing of the acquired chemical signals to remove baseline drift in the signal. The drift could originate from sensor characteristics or from background chemical activity in the surrounding environment. A recent emerging field is neurochemical monitoring to detect and quantify neural activity. In this paper, a resource efficient pre-processing system is presented to remove drift from the acquired neurochemical signal. The drift removal technique is based on baseline manipulation without requiring window based processing. The target application, for demonstration purposes, is the recording of vagal pH signals to enable closed-loop Vagus Nerve Stimulation (VNS). The final design is multiplier-free and results in an Application Specific Integrated Circuit (ASIC) that is 640 μm by 625 μm in area.","PeriodicalId":6569,"journal":{"name":"2018 IEEE International Symposium on Circuits and Systems (ISCAS)","volume":"31 1","pages":"1-5"},"PeriodicalIF":0.0,"publicationDate":"2018-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84723781","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 : 2018-05-27DOI: 10.1109/ISCAS.2018.8351204
A. Bevilacqua, M. Mottola
Computed Tomography perfusion (CTp) is a promising technique for estimating perfusion parameters, by analysing Time Concentration Curves (TCCs) of the administered contrast agent. However, several artefacts can degrade the signal quality, jeopardizing quantitative measurements. Despite different methods exploit TCCs to compute perfusion parameters, none of them has investigated how TCC fitting errors may affect final perfusion values. The first goal of this work is to investigate residuals distributions in significant signal's portions, then relating them to Blood Flow (BF). The Gamma Variate (GV) function is addressed to fit TCCs. Voxel-based BF is computed with the two most spread methods in literature, Maximum Slope (MS) and Deconvolution (DV). Experimental results prove that residuals coming from a Gaussian distribution yield percent errors maps locally smooth, thus attaining residuals-independent BF values. Besides results, the methodological approach can be spent in future researches in order to encourage CTp reproducibility.
{"title":"Analysis of the effects of fitting errors of DCE-CT signals on perfusion parameters","authors":"A. Bevilacqua, M. Mottola","doi":"10.1109/ISCAS.2018.8351204","DOIUrl":"https://doi.org/10.1109/ISCAS.2018.8351204","url":null,"abstract":"Computed Tomography perfusion (CTp) is a promising technique for estimating perfusion parameters, by analysing Time Concentration Curves (TCCs) of the administered contrast agent. However, several artefacts can degrade the signal quality, jeopardizing quantitative measurements. Despite different methods exploit TCCs to compute perfusion parameters, none of them has investigated how TCC fitting errors may affect final perfusion values. The first goal of this work is to investigate residuals distributions in significant signal's portions, then relating them to Blood Flow (BF). The Gamma Variate (GV) function is addressed to fit TCCs. Voxel-based BF is computed with the two most spread methods in literature, Maximum Slope (MS) and Deconvolution (DV). Experimental results prove that residuals coming from a Gaussian distribution yield percent errors maps locally smooth, thus attaining residuals-independent BF values. Besides results, the methodological approach can be spent in future researches in order to encourage CTp reproducibility.","PeriodicalId":6569,"journal":{"name":"2018 IEEE International Symposium on Circuits and Systems (ISCAS)","volume":"4 1","pages":"1-5"},"PeriodicalIF":0.0,"publicationDate":"2018-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80490801","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 : 2018-05-27DOI: 10.1109/ISCAS.2018.8350954
Benoît Larras, Paul Chollet, C. Lahuec, F. Seguin, M. Arzel
Clique-based neural networks implement low-complexity functions working with a reduced connectivity between neurons. Thus, they address very specific applications operating with a very low energy budget. This paper proposes a flexible and iterative neural architecture able to implement multiple types of clique-based neural networks of up to 3968 neurons. The circuit has been integrated in a ST 65-nm CMOS ASIC and validated in the context of ECG classification. The network core reacts in 83ns to a stimulation and occupies a 0.21mm2 silicon area.
{"title":"A fully flexible circuit implementation of clique-based neural networks in 65-nm CMOS","authors":"Benoît Larras, Paul Chollet, C. Lahuec, F. Seguin, M. Arzel","doi":"10.1109/ISCAS.2018.8350954","DOIUrl":"https://doi.org/10.1109/ISCAS.2018.8350954","url":null,"abstract":"Clique-based neural networks implement low-complexity functions working with a reduced connectivity between neurons. Thus, they address very specific applications operating with a very low energy budget. This paper proposes a flexible and iterative neural architecture able to implement multiple types of clique-based neural networks of up to 3968 neurons. The circuit has been integrated in a ST 65-nm CMOS ASIC and validated in the context of ECG classification. The network core reacts in 83ns to a stimulation and occupies a 0.21mm2 silicon area.","PeriodicalId":6569,"journal":{"name":"2018 IEEE International Symposium on Circuits and Systems (ISCAS)","volume":"58 1","pages":"1-4"},"PeriodicalIF":0.0,"publicationDate":"2018-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80630911","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 : 2018-05-27DOI: 10.1109/ISCAS.2018.8351308
Insani Abdi Bangsa, Dieuwert P. N. Mul, W. Serdijn
Stochastic resonance (SR) is a phenomenon in which noise can be employed to increase the performance of a system. It can e.g. be used to improve the performance of comparator-based circuits. This paper presents the analytical derivation of input-output relation, harmonic distortion, and noise behaviour of a 1-bit ADC using SR. Furthermore, the design of a new signal multiplier based on SR-ADCs is presented. The predicted behaviours are demonstrated by means of simulations. The work presented in this paper shows the potential for analog to digital conversion and integrated signal processing fully based on stochastic resonance.
{"title":"Stochastic Resonance Mixed-Signal Processing: Analog-to-Digital Conversion and Signal Processing Employing Noise","authors":"Insani Abdi Bangsa, Dieuwert P. N. Mul, W. Serdijn","doi":"10.1109/ISCAS.2018.8351308","DOIUrl":"https://doi.org/10.1109/ISCAS.2018.8351308","url":null,"abstract":"Stochastic resonance (SR) is a phenomenon in which noise can be employed to increase the performance of a system. It can e.g. be used to improve the performance of comparator-based circuits. This paper presents the analytical derivation of input-output relation, harmonic distortion, and noise behaviour of a 1-bit ADC using SR. Furthermore, the design of a new signal multiplier based on SR-ADCs is presented. The predicted behaviours are demonstrated by means of simulations. The work presented in this paper shows the potential for analog to digital conversion and integrated signal processing fully based on stochastic resonance.","PeriodicalId":6569,"journal":{"name":"2018 IEEE International Symposium on Circuits and Systems (ISCAS)","volume":"65 1","pages":"1-5"},"PeriodicalIF":0.0,"publicationDate":"2018-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83123014","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 : 2018-05-27DOI: 10.1109/ISCAS.2018.8351445
Soumya Bose, M. Johnston
Energy harvesting from ambient sources, such as body temperature, is an attractive solution for powering battery-less wearable electronics used for healthcare diagnostics. While feasible from an energy standpoint, initial start-up of an energy harvesting circuit from a millivolt-level thermoelectric generator output poses a particular challenge. One approach to boosting such a low input voltage is to use a low-voltage oscillator to start up a higher voltage DC-DC converter. In this work, we demonstrate a modified ring-oscillator architecture using a stacked three-inverter delay element, which can generate self-sustained oscillation from an input supply voltage as low as 50 mV. Compared to inductor-based on-chip oscillators or those using native transistors, this architecture significantly reduces circuit area and expands process compatibility. The start-up oscillator is implemented in a standard 0.18 μm CMOS process and comprises 21 stages; it generates a clock of frequency 9.5 kHz with a 86% voltage swing from an input supply voltage of 50 mV, while occupying less than 0.003 mm2 and consuming 818 pW.
{"title":"A Stacked-Inverter Ring Oscillator for 50 mV Fully-Integrated Cold-Start of Energy Harvesters","authors":"Soumya Bose, M. Johnston","doi":"10.1109/ISCAS.2018.8351445","DOIUrl":"https://doi.org/10.1109/ISCAS.2018.8351445","url":null,"abstract":"Energy harvesting from ambient sources, such as body temperature, is an attractive solution for powering battery-less wearable electronics used for healthcare diagnostics. While feasible from an energy standpoint, initial start-up of an energy harvesting circuit from a millivolt-level thermoelectric generator output poses a particular challenge. One approach to boosting such a low input voltage is to use a low-voltage oscillator to start up a higher voltage DC-DC converter. In this work, we demonstrate a modified ring-oscillator architecture using a stacked three-inverter delay element, which can generate self-sustained oscillation from an input supply voltage as low as 50 mV. Compared to inductor-based on-chip oscillators or those using native transistors, this architecture significantly reduces circuit area and expands process compatibility. The start-up oscillator is implemented in a standard 0.18 μm CMOS process and comprises 21 stages; it generates a clock of frequency 9.5 kHz with a 86% voltage swing from an input supply voltage of 50 mV, while occupying less than 0.003 mm2 and consuming 818 pW.","PeriodicalId":6569,"journal":{"name":"2018 IEEE International Symposium on Circuits and Systems (ISCAS)","volume":"10 1","pages":"1-5"},"PeriodicalIF":0.0,"publicationDate":"2018-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82436167","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}
This paper proposes a novel auto loss compensation (ALC) system to enable non-contact operations for capacitive coupled body channel communication (CC-BCC). The system employs a time-division compensation mismatch indicator (CMI) to continuously monitor the compensation error, and dynamically adjust the compensation inductor through a PI controller. With the close-loop topology, the proposed ALC system has three advantages: First, the path loss induced by non-contact status and backward coupling effect can be compensated simultaneously; Second, this system can dynamically attenuate the path losses, even when the channel characteristics vary with time; Third, this system has high robustness, which is insusceptible to channel variations; The simulation results show that the loss reduction of the proposed ALC system is 18 dB higher than the conventional compensation technique in the worst case.
{"title":"An Auto Loss Compensation System for Non-contact Capacitive Coupled Body Channel Communication","authors":"Jian Zhao, Jingna Mao, Tong Zhou, Longqiang Lai, Huazhong Yang, Bo Zhao","doi":"10.1109/ISCAS.2018.8351340","DOIUrl":"https://doi.org/10.1109/ISCAS.2018.8351340","url":null,"abstract":"This paper proposes a novel auto loss compensation (ALC) system to enable non-contact operations for capacitive coupled body channel communication (CC-BCC). The system employs a time-division compensation mismatch indicator (CMI) to continuously monitor the compensation error, and dynamically adjust the compensation inductor through a PI controller. With the close-loop topology, the proposed ALC system has three advantages: First, the path loss induced by non-contact status and backward coupling effect can be compensated simultaneously; Second, this system can dynamically attenuate the path losses, even when the channel characteristics vary with time; Third, this system has high robustness, which is insusceptible to channel variations; The simulation results show that the loss reduction of the proposed ALC system is 18 dB higher than the conventional compensation technique in the worst case.","PeriodicalId":6569,"journal":{"name":"2018 IEEE International Symposium on Circuits and Systems (ISCAS)","volume":"30 1","pages":"1-5"},"PeriodicalIF":0.0,"publicationDate":"2018-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82441599","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 : 2018-05-27DOI: 10.1109/ISCAS.2018.8350921
Wu-Sheng Lu, T. Hinamoto
This paper presents an enhanced Steiglitz-McBride (SM) procedure for the design of stable minimax IIR digital filters. It is well known that minimax design of IIR filters is typically initiated with a nonconvex formulation, followed by a procedure to relax the original design problem to a sequence of convex sub-problems to be solved iteratively. We proposed an enhanced SM procedure that leads to improved convex relaxation relative to the conventional SM techniques, hence to improved designs. In addition, we make an observation that the state-of-the-art convex stability constraint based on strictly positive realness is equivalent to that deduced from an enhanced version of Rouché theorem from complex analysis. Design examples are presented to evaluate the new design algorithm.
{"title":"Enhanced Steiglitz-McBride Procedure for Minimax IIR Digital Filters","authors":"Wu-Sheng Lu, T. Hinamoto","doi":"10.1109/ISCAS.2018.8350921","DOIUrl":"https://doi.org/10.1109/ISCAS.2018.8350921","url":null,"abstract":"This paper presents an enhanced Steiglitz-McBride (SM) procedure for the design of stable minimax IIR digital filters. It is well known that minimax design of IIR filters is typically initiated with a nonconvex formulation, followed by a procedure to relax the original design problem to a sequence of convex sub-problems to be solved iteratively. We proposed an enhanced SM procedure that leads to improved convex relaxation relative to the conventional SM techniques, hence to improved designs. In addition, we make an observation that the state-of-the-art convex stability constraint based on strictly positive realness is equivalent to that deduced from an enhanced version of Rouché theorem from complex analysis. Design examples are presented to evaluate the new design algorithm.","PeriodicalId":6569,"journal":{"name":"2018 IEEE International Symposium on Circuits and Systems (ISCAS)","volume":"5 1","pages":"1-5"},"PeriodicalIF":0.0,"publicationDate":"2018-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80909150","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 : 2018-05-27DOI: 10.1109/ISCAS.2018.8351714
C. Strobl, Maximilian Schäfer, R. Rabenstein
Low end extra low voltage direct current grids require selective fault protection designed for the specific application and system voltage. System identification and machine learning methods are helpful to identify, to localize and to classify occurring fault events. A category of non-recursive large-signal methods in the time domain for system identification and for refined fault detection and analysis is introduced.
{"title":"Non-Recursive System Identification and Fault Detection in LVDC and ELVDC Grids","authors":"C. Strobl, Maximilian Schäfer, R. Rabenstein","doi":"10.1109/ISCAS.2018.8351714","DOIUrl":"https://doi.org/10.1109/ISCAS.2018.8351714","url":null,"abstract":"Low end extra low voltage direct current grids require selective fault protection designed for the specific application and system voltage. System identification and machine learning methods are helpful to identify, to localize and to classify occurring fault events. A category of non-recursive large-signal methods in the time domain for system identification and for refined fault detection and analysis is introduced.","PeriodicalId":6569,"journal":{"name":"2018 IEEE International Symposium on Circuits and Systems (ISCAS)","volume":"3 1","pages":"1-5"},"PeriodicalIF":0.0,"publicationDate":"2018-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89706074","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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