Pub Date : 2018-06-01DOI: 10.1109/ICGPR.2018.8441542
V. Ruban, G. Pochanin, O. O. Shuba, O. Pochanin, O. Ya
The paper discusses the criteria of the optimal sample width for sampling (equivalent time) GPR receiver. The Pearson correlation coefficient is proposed as an optimum criterion. The influence of noise on the choice of the optimal sample width is analyzed. Suggested methodology is illustrated on sampling conversion of a Gaussian signal and a signal with reflection.
{"title":"Optimization of Sampling Converter for GPR Receiver","authors":"V. Ruban, G. Pochanin, O. O. Shuba, O. Pochanin, O. Ya","doi":"10.1109/ICGPR.2018.8441542","DOIUrl":"https://doi.org/10.1109/ICGPR.2018.8441542","url":null,"abstract":"The paper discusses the criteria of the optimal sample width for sampling (equivalent time) GPR receiver. The Pearson correlation coefficient is proposed as an optimum criterion. The influence of noise on the choice of the optimal sample width is analyzed. Suggested methodology is illustrated on sampling conversion of a Gaussian signal and a signal with reflection.","PeriodicalId":269482,"journal":{"name":"2018 17th International Conference on Ground Penetrating Radar (GPR)","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126142019","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 : 2018-06-01DOI: 10.1109/ICGPR.2018.8441665
Arvind Srivastav, D. Ariando, S. Mandal
Ground penetrating radar (GPR) has broad applications in non-destructive subsurface imaging. Most GPRs on the market are bistatic devices that illuminate the buried objects using analog pulses with simple Gaussian-like shapes. These GPRs suffer from drift in the scan results and have either a low-resolution or a low depth of scan, which limits their application. High resolution along with an increased depth of scan can be achieved by transmitting maximal length pseudorandom sequences (m-sequences) which enable pulse compression due to their near-ideal autocorrelation properties. In addition, improved object localization and reduced drift can be obtained with the spatial diversity offered by a MIMO transceiver. This paper discusses the design and implementation of a 8 × 8 MIMO-capable impulse-based GPR that transmits m-sequences generated on a low-cost FPGA platform, performs a quadrature transform on the received signal to reduce computation, and implements subsampling to sample the quadrature-converted signals using low-speed ADCs. Preliminary experimental results are also presented.
{"title":"An FPGA-based Flexible and MIMO-capable GPR System","authors":"Arvind Srivastav, D. Ariando, S. Mandal","doi":"10.1109/ICGPR.2018.8441665","DOIUrl":"https://doi.org/10.1109/ICGPR.2018.8441665","url":null,"abstract":"Ground penetrating radar (GPR) has broad applications in non-destructive subsurface imaging. Most GPRs on the market are bistatic devices that illuminate the buried objects using analog pulses with simple Gaussian-like shapes. These GPRs suffer from drift in the scan results and have either a low-resolution or a low depth of scan, which limits their application. High resolution along with an increased depth of scan can be achieved by transmitting maximal length pseudorandom sequences (m-sequences) which enable pulse compression due to their near-ideal autocorrelation properties. In addition, improved object localization and reduced drift can be obtained with the spatial diversity offered by a MIMO transceiver. This paper discusses the design and implementation of a 8 × 8 MIMO-capable impulse-based GPR that transmits m-sequences generated on a low-cost FPGA platform, performs a quadrature transform on the received signal to reduce computation, and implements subsampling to sample the quadrature-converted signals using low-speed ADCs. Preliminary experimental results are also presented.","PeriodicalId":269482,"journal":{"name":"2018 17th International Conference on Ground Penetrating Radar (GPR)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129348108","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 : 2018-06-01DOI: 10.1109/ICGPR.2018.8441657
H. Qin, Xiongyao Xie, Yu Tang, Zhengzheng Wang
In this paper we discuss the implementation of crosshole ground-penetrating radar (GPR) method in diaphragm wall defect detection. The construction process of a diaphragm wall panel is introduced and different types of defects including crack, void, sludge accumulation, joint leakage, and joint split are summarized. The zero-offset profiling (ZOP) survey is advised to be carried out to quickly locate anomalous zones in diaphragm walls, followed by a multi-offset gather (MOG) survey to characterize the exact position, size and shape of defects. Numerical simulations are performed to analyze ZOP and MOG data of each type of defects. Results show that the crosshole GPR is an effective tool for diaphragm wall defect detection.
{"title":"Detection of Diaphragm Wall Defects Using Crosshole GPR","authors":"H. Qin, Xiongyao Xie, Yu Tang, Zhengzheng Wang","doi":"10.1109/ICGPR.2018.8441657","DOIUrl":"https://doi.org/10.1109/ICGPR.2018.8441657","url":null,"abstract":"In this paper we discuss the implementation of crosshole ground-penetrating radar (GPR) method in diaphragm wall defect detection. The construction process of a diaphragm wall panel is introduced and different types of defects including crack, void, sludge accumulation, joint leakage, and joint split are summarized. The zero-offset profiling (ZOP) survey is advised to be carried out to quickly locate anomalous zones in diaphragm walls, followed by a multi-offset gather (MOG) survey to characterize the exact position, size and shape of defects. Numerical simulations are performed to analyze ZOP and MOG data of each type of defects. Results show that the crosshole GPR is an effective tool for diaphragm wall defect detection.","PeriodicalId":269482,"journal":{"name":"2018 17th International Conference on Ground Penetrating Radar (GPR)","volume":"51 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128556100","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 : 2018-06-01DOI: 10.1109/ICGPR.2018.8441643
Cheng-Hao Wang, Xian-Lin Liu
Ground Penetrating Radar has been widely used in nondestructive testing, but its interpretation is difficult. This text put forward to the algorithm of recognizing object based on short-time Fourier transform (STFT), the signal is analyzed in time-frequency domain to obtain the rolling spectrum, and then calculated threshold using Otsu arithmetic to convert to binary number, so that the object can be recognized using the algorithm of label connected components. The experiment expressed this algorithm can recognize the object of the GPR signal effectively, and indicated that STFT can improve object recognition greatly.
{"title":"Study of object recognition with GPR based on STFT","authors":"Cheng-Hao Wang, Xian-Lin Liu","doi":"10.1109/ICGPR.2018.8441643","DOIUrl":"https://doi.org/10.1109/ICGPR.2018.8441643","url":null,"abstract":"Ground Penetrating Radar has been widely used in nondestructive testing, but its interpretation is difficult. This text put forward to the algorithm of recognizing object based on short-time Fourier transform (STFT), the signal is analyzed in time-frequency domain to obtain the rolling spectrum, and then calculated threshold using Otsu arithmetic to convert to binary number, so that the object can be recognized using the algorithm of label connected components. The experiment expressed this algorithm can recognize the object of the GPR signal effectively, and indicated that STFT can improve object recognition greatly.","PeriodicalId":269482,"journal":{"name":"2018 17th International Conference on Ground Penetrating Radar (GPR)","volume":"89 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124536167","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 : 2018-06-01DOI: 10.1109/ICGPR.2018.8441596
G. K. Sharma, T. Kind
We investigated the possibility of surrounding waves along with perimeter of large diameter tendon ducts during ground penetrating radar (GPR) testing of concrete structures. The surrounding waves influence the primary reflection from tendon duct and alter the phase as well as amplitude of signal depending on the diameter of the tendon duct. This phenomenon was studied in detail by conducting several simulations using a commercial software Reflexw®. Finite Difference Time Domain method was adopted to analyze reflection patterns from objects of various diameters located at different depths in concrete media. The proposed methodology will be useful in qualitative assessment of size of metallic objects greater than a diameter of 6 cm. In general, the identification of large diameter tendon ducts in a civil structure is carried out by prior knowledge of the civil plan and its diagonal appearance to smaller diameter object mesh. The proposed methodology will enhance the confidence in identification of the larger diameter tendon ducts even if the civil plan is not known accurately.
{"title":"Distinction of tendon ducts and rebars by GPR reflection signal patterns","authors":"G. K. Sharma, T. Kind","doi":"10.1109/ICGPR.2018.8441596","DOIUrl":"https://doi.org/10.1109/ICGPR.2018.8441596","url":null,"abstract":"We investigated the possibility of surrounding waves along with perimeter of large diameter tendon ducts during ground penetrating radar (GPR) testing of concrete structures. The surrounding waves influence the primary reflection from tendon duct and alter the phase as well as amplitude of signal depending on the diameter of the tendon duct. This phenomenon was studied in detail by conducting several simulations using a commercial software Reflexw®. Finite Difference Time Domain method was adopted to analyze reflection patterns from objects of various diameters located at different depths in concrete media. The proposed methodology will be useful in qualitative assessment of size of metallic objects greater than a diameter of 6 cm. In general, the identification of large diameter tendon ducts in a civil structure is carried out by prior knowledge of the civil plan and its diagonal appearance to smaller diameter object mesh. The proposed methodology will enhance the confidence in identification of the larger diameter tendon ducts even if the civil plan is not known accurately.","PeriodicalId":269482,"journal":{"name":"2018 17th International Conference on Ground Penetrating Radar (GPR)","volume":"85 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124659451","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 : 2018-06-01DOI: 10.1109/ICGPR.2018.8441615
Sixin Liu, Xudong Wang, L. Fu, Bin Wei
A borehole radar investigation was performed at Sanzuodian reservoir, Chifeng, China to assess the existence of the deep rock-filled dam leakage. The key methodology used includes both single-hole reflection profile and cross-hole radar tomography, which allowed identification of the hydraulic connections between the upstream side and the downstream side in deep foundation. The leakage path is characterized by direct wave loss due to high attenuation in single-hole reflection profile, and horizontal banded low-velocity zone in cross-hole velocity tomography. Meanwhile, the core wall thickness change point, connection point of asphalt/concrete wall, and the water saturated interface can be identified by single-hole reflection clearly. The interpreted leakage path is proven by water flow measurement. Borehole radar is a high-resolution tool fitted for deep detection.
{"title":"Application of borehole radar for dam leakage detection","authors":"Sixin Liu, Xudong Wang, L. Fu, Bin Wei","doi":"10.1109/ICGPR.2018.8441615","DOIUrl":"https://doi.org/10.1109/ICGPR.2018.8441615","url":null,"abstract":"A borehole radar investigation was performed at Sanzuodian reservoir, Chifeng, China to assess the existence of the deep rock-filled dam leakage. The key methodology used includes both single-hole reflection profile and cross-hole radar tomography, which allowed identification of the hydraulic connections between the upstream side and the downstream side in deep foundation. The leakage path is characterized by direct wave loss due to high attenuation in single-hole reflection profile, and horizontal banded low-velocity zone in cross-hole velocity tomography. Meanwhile, the core wall thickness change point, connection point of asphalt/concrete wall, and the water saturated interface can be identified by single-hole reflection clearly. The interpreted leakage path is proven by water flow measurement. Borehole radar is a high-resolution tool fitted for deep detection.","PeriodicalId":269482,"journal":{"name":"2018 17th International Conference on Ground Penetrating Radar (GPR)","volume":"486 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122820816","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 : 2018-06-01DOI: 10.1109/ICGPR.2018.8441691
Linlin Lei, Chongmei Zhong, Li Zhang, Qingming Zhao, Huan Yan, L. Fu, Sixin Liu
Reverse-time migration (RTM) has been widely used for imaging subsurface structure in seismic surveys for hydrocarbon resource explorations. It has been adopted for migrating ground penetrating radar (GPR) data due to the kinematics and dynamics similarity between electromagnetic and seismic waves. Low-frequency migration artifacts happen when the conventional image condition is used, especially when the migration model is not smooth. In this abstract, we decompose the wavefield into left-and right-going wavefield based on the Hilbert transform, and then apply the image condition to generate migration image in which the low-frequency noise are largely eliminated. Synthetic results suggest more clear image can be obtained using the isolated wavefiled to construct RTM image.
{"title":"Reverse Time Migration of Crosswell GPR Data Based on Wavefield Decomposition","authors":"Linlin Lei, Chongmei Zhong, Li Zhang, Qingming Zhao, Huan Yan, L. Fu, Sixin Liu","doi":"10.1109/ICGPR.2018.8441691","DOIUrl":"https://doi.org/10.1109/ICGPR.2018.8441691","url":null,"abstract":"Reverse-time migration (RTM) has been widely used for imaging subsurface structure in seismic surveys for hydrocarbon resource explorations. It has been adopted for migrating ground penetrating radar (GPR) data due to the kinematics and dynamics similarity between electromagnetic and seismic waves. Low-frequency migration artifacts happen when the conventional image condition is used, especially when the migration model is not smooth. In this abstract, we decompose the wavefield into left-and right-going wavefield based on the Hilbert transform, and then apply the image condition to generate migration image in which the low-frequency noise are largely eliminated. Synthetic results suggest more clear image can be obtained using the isolated wavefiled to construct RTM image.","PeriodicalId":269482,"journal":{"name":"2018 17th International Conference on Ground Penetrating Radar (GPR)","volume":"62 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127211726","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 : 2018-06-01DOI: 10.1109/ICGPR.2018.8441570
A. Lejzerowicz
Ground penetrating radar (GPR) investigations were conducted to characterise internal architecture of Narew River point bar and the riverbed morphology. The study area is situated in north of Warsaw (Central Poland), close to place where Narew River is flowing into Vistula River. 32 GPR profiles were taken on the most accessible point bar using 300 and 125 MHz antennas. Also 5 GPR profiles from water have been made - the survey was conducted from a pontoon with installed 125 and 70 MHz antennas. All profiles were collected using Transient Technologies VIY3 GPR. In this paper characteristic ground penetrating radar profiles are presented, to show both internal architecture of fluvial deposits and the riverbed morphology. Interpretation of selected GPR profiles showed the presence of erosional surfaces and the diversity of the riverbed morphology of Narew River.
{"title":"Internal architecture of fluvial deposits and the morphology of the selected sections of Narew River valley in Warsaw area (central Poland) based on GPR investigations","authors":"A. Lejzerowicz","doi":"10.1109/ICGPR.2018.8441570","DOIUrl":"https://doi.org/10.1109/ICGPR.2018.8441570","url":null,"abstract":"Ground penetrating radar (GPR) investigations were conducted to characterise internal architecture of Narew River point bar and the riverbed morphology. The study area is situated in north of Warsaw (Central Poland), close to place where Narew River is flowing into Vistula River. 32 GPR profiles were taken on the most accessible point bar using 300 and 125 MHz antennas. Also 5 GPR profiles from water have been made - the survey was conducted from a pontoon with installed 125 and 70 MHz antennas. All profiles were collected using Transient Technologies VIY3 GPR. In this paper characteristic ground penetrating radar profiles are presented, to show both internal architecture of fluvial deposits and the riverbed morphology. Interpretation of selected GPR profiles showed the presence of erosional surfaces and the diversity of the riverbed morphology of Narew River.","PeriodicalId":269482,"journal":{"name":"2018 17th International Conference on Ground Penetrating Radar (GPR)","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125707114","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 : 2018-06-01DOI: 10.1109/ICGPR.2018.8441580
M. Pieraccini, L. Miccinesi
In this paper a no-contact ground penetrating radar for investigating painted walls is presented. It operates at 10 GHz central frequency with 4 GHz bandwidth. Its mechanical positioner is able to scan a surface 1.4 m wide and 1.9 m high. This equipment has been specifically designed for investigating the painted walls of the Tutankhamon tomb in the Kings' valley in Egypt. The aim of this radar survey is to gather information about the shallow layers (the plaster and the existence of possible plaster voids affecting the future stability of paintings) up to 0.5 m depth.
{"title":"No-contact GPR for investigating painted walls","authors":"M. Pieraccini, L. Miccinesi","doi":"10.1109/ICGPR.2018.8441580","DOIUrl":"https://doi.org/10.1109/ICGPR.2018.8441580","url":null,"abstract":"In this paper a no-contact ground penetrating radar for investigating painted walls is presented. It operates at 10 GHz central frequency with 4 GHz bandwidth. Its mechanical positioner is able to scan a surface 1.4 m wide and 1.9 m high. This equipment has been specifically designed for investigating the painted walls of the Tutankhamon tomb in the Kings' valley in Egypt. The aim of this radar survey is to gather information about the shallow layers (the plaster and the existence of possible plaster voids affecting the future stability of paintings) up to 0.5 m depth.","PeriodicalId":269482,"journal":{"name":"2018 17th International Conference on Ground Penetrating Radar (GPR)","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126111484","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 : 2018-06-01DOI: 10.1109/ICGPR.2018.8441521
Lanbo Liu, Guofeng Liu, R. Qian, Qinghua Huang, Zhanhui Li
This paper focuses on the study of the scattering of radar waves due to rugged topography relief. It is a helpful assistance to identify features in GPR reflection profile to separate true subsurface reflectors and artifacts caused by surface scatterers. Two examples are presented here to illustrate the approach. The first case is for a numerical simulation of the edge diffraction from rugged topographic relief on Earth. The other is one from the numerical model of the 60-MHz radar wave propagation to look into the edge diffraction caused by the impact crater depressions based on the real topography and stratigraphy of the lunar surface at the landing site of the 2014 Chinese lunar lander Chang'e-3. The purpose of this study is to explore the possibility to explain the featured events in the lunar penetration radar (LPR) profile recorded by the Yutu lunar rover, which were originally identified as subsurface reflectors from stratigraphic interfaces. It is noteworthy to point out that the 60-MHz radar system on the Yutu lunar rover uses the unshielded rod antennas. Substantial portion of the radiated energy is in the air above the lunar surface. The simulation of lunar radar wave propagation suggests that it is likely that the later time events in the 60-MHz LPR profile might be associated with the focused surface scattering waves from the edge of the impact craters near the Chang'e-3 landing site.
{"title":"High-Performance Numerical Simulation of Radar Wave Scattering due to Topographic Roughness","authors":"Lanbo Liu, Guofeng Liu, R. Qian, Qinghua Huang, Zhanhui Li","doi":"10.1109/ICGPR.2018.8441521","DOIUrl":"https://doi.org/10.1109/ICGPR.2018.8441521","url":null,"abstract":"This paper focuses on the study of the scattering of radar waves due to rugged topography relief. It is a helpful assistance to identify features in GPR reflection profile to separate true subsurface reflectors and artifacts caused by surface scatterers. Two examples are presented here to illustrate the approach. The first case is for a numerical simulation of the edge diffraction from rugged topographic relief on Earth. The other is one from the numerical model of the 60-MHz radar wave propagation to look into the edge diffraction caused by the impact crater depressions based on the real topography and stratigraphy of the lunar surface at the landing site of the 2014 Chinese lunar lander Chang'e-3. The purpose of this study is to explore the possibility to explain the featured events in the lunar penetration radar (LPR) profile recorded by the Yutu lunar rover, which were originally identified as subsurface reflectors from stratigraphic interfaces. It is noteworthy to point out that the 60-MHz radar system on the Yutu lunar rover uses the unshielded rod antennas. Substantial portion of the radiated energy is in the air above the lunar surface. The simulation of lunar radar wave propagation suggests that it is likely that the later time events in the 60-MHz LPR profile might be associated with the focused surface scattering waves from the edge of the impact craters near the Chang'e-3 landing site.","PeriodicalId":269482,"journal":{"name":"2018 17th International Conference on Ground Penetrating Radar (GPR)","volume":"219 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134027231","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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