In this study, we developed a light source position estimation system for controlling the wireless-powered drone. An algorithm was designed to estimate the light source position by minimizing an error function consisting of the difference between the measured and estimated values of light-receiving intensity. The received light intensity distribution of a light source with a beam angle of 2.5° was modeled using Gaussian and inverse square functions based on actual measurements. A detection device was fabricated by a photodiode array substrate and a Raspberry Pi. The detection time of the developed system is 97 ms, real-time light source position estimation was confirmed.
{"title":"Development of a Light Source Position Estimation System for Accurate Drone Flight","authors":"Ryo Goto;Takayuki Matsumuro;Kazunobu Serizawa;Susumu Ano;Satoru Shimizu","doi":"10.23919/comex.2024COL0025","DOIUrl":"https://doi.org/10.23919/comex.2024COL0025","url":null,"abstract":"In this study, we developed a light source position estimation system for controlling the wireless-powered drone. An algorithm was designed to estimate the light source position by minimizing an error function consisting of the difference between the measured and estimated values of light-receiving intensity. The received light intensity distribution of a light source with a beam angle of 2.5° was modeled using Gaussian and inverse square functions based on actual measurements. A detection device was fabricated by a photodiode array substrate and a Raspberry Pi. The detection time of the developed system is 97 ms, real-time light source position estimation was confirmed.","PeriodicalId":54101,"journal":{"name":"IEICE Communications Express","volume":"13 12","pages":"483-486"},"PeriodicalIF":0.3,"publicationDate":"2024-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10633228","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142761406","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-09DOI: 10.23919/comex.2024COL0017
Masahiro Fujii
In this letter, I introduce Root Mean Squared Error (RMSE) based on the Fisher information matrix to evaluate the accuracy of distance-based location estimation. This qualitative index, which introduces the concept of the distribution of ranging measurement errors, allows a more precise evaluation of position estimation accuracy than the conventional Position Dilution Of Precision (PDOP). Visualizing PDOP and the proposed RMSE as a distribution over the evaluation space clarifies their respective characteristics. By computer simulations, I show usefulness of the propsoed index by comparing with Least-Squares estimation.
{"title":"An Analysis of Positioning Accuracy Based on Fisher Information Matrix for Distance-Based Positioning","authors":"Masahiro Fujii","doi":"10.23919/comex.2024COL0017","DOIUrl":"https://doi.org/10.23919/comex.2024COL0017","url":null,"abstract":"In this letter, I introduce Root Mean Squared Error (RMSE) based on the Fisher information matrix to evaluate the accuracy of distance-based location estimation. This qualitative index, which introduces the concept of the distribution of ranging measurement errors, allows a more precise evaluation of position estimation accuracy than the conventional Position Dilution Of Precision (PDOP). Visualizing PDOP and the proposed RMSE as a distribution over the evaluation space clarifies their respective characteristics. By computer simulations, I show usefulness of the propsoed index by comparing with Least-Squares estimation.","PeriodicalId":54101,"journal":{"name":"IEICE Communications Express","volume":"13 12","pages":"479-482"},"PeriodicalIF":0.3,"publicationDate":"2024-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10633231","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142761479","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-09DOI: 10.23919/comex.2024XBL0125
Muhammad Hamka Ibrahim;Subuh Pramono;Jing-Yuan Wang;Yu-Fan Cai;Feri Adriyanto;Josaphat Tetuko Sri Sumantyo
Polarimetric synthetic aperture radar (PolSAR) image exhibits a high degree of spatial information. However, the PolSAR image is subjected to speckle noise, which degrades the information quality. A speckle correction filter is proposed in this paper based on spatial polarimetric coherence. Evidence of polarimetric coherence between spatial neighboring pixels is presented. It shows that polarimetric coherence is highly correlated with neighboring pixels. Based on these characteristics, a speckle correction filter is proposed by calculating the polarimetric coherency level on a selected neighboring pixel. A correction is applied to the pixel which has a low polarimetric coherence level. A generalized three-step adaptive filter is proposed, including neighbor selection, coherency criterion, and incoherent correction. The influence of the filter on scattering mechanisms is compared by using eigenvalue-based decomposition. Qualitatively, the result shows the proposed correction filter removes the outliers in the low entropy region. Quantitively the filter can suppress the speckle noise and its variance up to 19.08%.
{"title":"Speckle Correction Filter Based on Spatial Polarimetric Coherence for Full Polarimetric Synthetic Aperture Radar Image","authors":"Muhammad Hamka Ibrahim;Subuh Pramono;Jing-Yuan Wang;Yu-Fan Cai;Feri Adriyanto;Josaphat Tetuko Sri Sumantyo","doi":"10.23919/comex.2024XBL0125","DOIUrl":"https://doi.org/10.23919/comex.2024XBL0125","url":null,"abstract":"Polarimetric synthetic aperture radar (PolSAR) image exhibits a high degree of spatial information. However, the PolSAR image is subjected to speckle noise, which degrades the information quality. A speckle correction filter is proposed in this paper based on spatial polarimetric coherence. Evidence of polarimetric coherence between spatial neighboring pixels is presented. It shows that polarimetric coherence is highly correlated with neighboring pixels. Based on these characteristics, a speckle correction filter is proposed by calculating the polarimetric coherency level on a selected neighboring pixel. A correction is applied to the pixel which has a low polarimetric coherence level. A generalized three-step adaptive filter is proposed, including neighbor selection, coherency criterion, and incoherent correction. The influence of the filter on scattering mechanisms is compared by using eigenvalue-based decomposition. Qualitatively, the result shows the proposed correction filter removes the outliers in the low entropy region. Quantitively the filter can suppress the speckle noise and its variance up to 19.08%.","PeriodicalId":54101,"journal":{"name":"IEICE Communications Express","volume":"13 10","pages":"413-416"},"PeriodicalIF":0.3,"publicationDate":"2024-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10633226","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142376979","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-09DOI: 10.23919/comex.2024XBL0115
Makoto Sano;Ryuji Kuse;Takeshi Fukusako
This paper presents a new concept of designing circularly polarized folded reflectarray (CPFRA) antennas. By applying the dual-reflector shaping technique to the CPFRA antennas, the reflection-phase distributions of the two reflecting surfaces comprising the CPFRA antennas are modified to realize low profile, high aperture efficiency, and arbitrary aperture-field distribution simultaneously. Numerical simulations based on the geometrical optics show that the aperture efficiency can be improved up to around 100% by realizing uniform aperture-field distribution and reducing the spillover. Designs of CPFRA antennas with low sidelobe levels are also presented.
{"title":"Reflection-Phase Calculation of Circularly Polarized Folded Reflectarray Antennas with Low Profile, High Efficiency, and Arbitrary Aperture Distribution","authors":"Makoto Sano;Ryuji Kuse;Takeshi Fukusako","doi":"10.23919/comex.2024XBL0115","DOIUrl":"https://doi.org/10.23919/comex.2024XBL0115","url":null,"abstract":"This paper presents a new concept of designing circularly polarized folded reflectarray (CPFRA) antennas. By applying the dual-reflector shaping technique to the CPFRA antennas, the reflection-phase distributions of the two reflecting surfaces comprising the CPFRA antennas are modified to realize low profile, high aperture efficiency, and arbitrary aperture-field distribution simultaneously. Numerical simulations based on the geometrical optics show that the aperture efficiency can be improved up to around 100% by realizing uniform aperture-field distribution and reducing the spillover. Designs of CPFRA antennas with low sidelobe levels are also presented.","PeriodicalId":54101,"journal":{"name":"IEICE Communications Express","volume":"13 10","pages":"409-412"},"PeriodicalIF":0.3,"publicationDate":"2024-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10633229","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142377146","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
To build a stable wireless communication system in an indoor environment, it is necessary to perform highly accurate simulations of radio wave propagation characteristics. The ITU-R Recommendation P series, especially ITU-R P.1238, lists estimation models for propagation loss in indoor environments under various conditions. However, there are a few cases in which propagation loss has been measured at various frequencies in the same building and under the same conditions. In these cases, necessary parameters may not be described, meaning that simulation cannot be easily performed. In this paper, we measure the radio wave propagation characteristics on the same floor and across floors for the 922 MHz to 28 GHz frequency band, which is often used in office spaces. We then apply a path loss model to each frequency and calculate the coefficient of office environment ( $N$ ) and inter-floor attenuation $(L_{f}(n))$ .
{"title":"Path Loss Model from 922 MHz to 28 GHz in Office Environment","authors":"Kensuke Sakamoto;Ayaka Sakaguchi;Yuki Yamakawa;Waka Mimura;Hirokazu Sawada;Azril Haniz;Fumihide Kojima;Takeshi Matsumura","doi":"10.23919/comex.2024XBL0120","DOIUrl":"https://doi.org/10.23919/comex.2024XBL0120","url":null,"abstract":"To build a stable wireless communication system in an indoor environment, it is necessary to perform highly accurate simulations of radio wave propagation characteristics. The ITU-R Recommendation P series, especially ITU-R P.1238, lists estimation models for propagation loss in indoor environments under various conditions. However, there are a few cases in which propagation loss has been measured at various frequencies in the same building and under the same conditions. In these cases, necessary parameters may not be described, meaning that simulation cannot be easily performed. In this paper, we measure the radio wave propagation characteristics on the same floor and across floors for the 922 MHz to 28 GHz frequency band, which is often used in office spaces. We then apply a path loss model to each frequency and calculate the coefficient of office environment (\u0000<tex>$N$</tex>\u0000) and inter-floor attenuation \u0000<tex>$(L_{f}(n))$</tex>\u0000.","PeriodicalId":54101,"journal":{"name":"IEICE Communications Express","volume":"13 10","pages":"417-420"},"PeriodicalIF":0.3,"publicationDate":"2024-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10633227","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142377144","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-09DOI: 10.23919/comex.2024COL0018
Yuma Sakurai;Yoshihiro Ito
In recent years, functions in automobiles are required to be processed in real time. This requirement can be realized with SDV (Software-Defined Vehicle), a technology that defines vehicle requirements in software. Although SDV requires automotive SDN (Software-Defined Networking), there has been little discussion on how to implement automotive SDN. This paper studies the feasibility of automotive SDN by realizing four functional requirements proposed as functions required for automotive SDN using P4 and evaluating these requirements through experiments. The feasibility of automotive SDN will be investigated by evaluating these requirements through experiments.
{"title":"A Study on Realization of Automotive SDN by P4","authors":"Yuma Sakurai;Yoshihiro Ito","doi":"10.23919/comex.2024COL0018","DOIUrl":"https://doi.org/10.23919/comex.2024COL0018","url":null,"abstract":"In recent years, functions in automobiles are required to be processed in real time. This requirement can be realized with SDV (Software-Defined Vehicle), a technology that defines vehicle requirements in software. Although SDV requires automotive SDN (Software-Defined Networking), there has been little discussion on how to implement automotive SDN. This paper studies the feasibility of automotive SDN by realizing four functional requirements proposed as functions required for automotive SDN using P4 and evaluating these requirements through experiments. The feasibility of automotive SDN will be investigated by evaluating these requirements through experiments.","PeriodicalId":54101,"journal":{"name":"IEICE Communications Express","volume":"13 12","pages":"475-478"},"PeriodicalIF":0.3,"publicationDate":"2024-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10633223","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142761552","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-09DOI: 10.23919/comex.2024XBL0100
Huanqian Xiong;Jiro Hirokawa;Takashi Tomura
This letter deals with the difference-beam operation in a centerfeed dual-polarized parallel-plate waveguide slot array antenna at 24.5GHz, which consists of two orthogonally arranged 20×19 arrays of radiating slot pairs. A center-feeding scheme is employed in this design. Each rectangular feeding waveguide, fed by a probe, can feed half of the radiating panel, enabling easy control of the phase difference. Experimental results show that the monopulse antenna array has a bandwidth of 12.8% for reflections below −10 dB while it produces the sum beams, and 13.3% to produce the difference beams. Port isolation between the sum mode and difference mode is above 15 dB within the working frequency band. The measured realized gain of the sum beam is 31.3 dBi at 24.5 GHz, and the measured null-depth is below −33.9 dB for both polarizations.
{"title":"Difference-Beam Operation in a Center-Fed Dual-Polarized Parallel-Plate Waveguide Slot Array Antenna","authors":"Huanqian Xiong;Jiro Hirokawa;Takashi Tomura","doi":"10.23919/comex.2024XBL0100","DOIUrl":"https://doi.org/10.23919/comex.2024XBL0100","url":null,"abstract":"This letter deals with the difference-beam operation in a centerfeed dual-polarized parallel-plate waveguide slot array antenna at 24.5GHz, which consists of two orthogonally arranged 20×19 arrays of radiating slot pairs. A center-feeding scheme is employed in this design. Each rectangular feeding waveguide, fed by a probe, can feed half of the radiating panel, enabling easy control of the phase difference. Experimental results show that the monopulse antenna array has a bandwidth of 12.8% for reflections below −10 dB while it produces the sum beams, and 13.3% to produce the difference beams. Port isolation between the sum mode and difference mode is above 15 dB within the working frequency band. The measured realized gain of the sum beam is 31.3 dBi at 24.5 GHz, and the measured null-depth is below −33.9 dB for both polarizations.","PeriodicalId":54101,"journal":{"name":"IEICE Communications Express","volume":"13 9","pages":"359-362"},"PeriodicalIF":0.3,"publicationDate":"2024-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10591717","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142091059","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A visible light communication (VLC) system offers notable advantages, and leveraging image sensors as VLC receivers holds promise. The rolling shutter image sensor stands out as a popular candidate among these sensors. However, challenges arise from signal loss from inter-frame gaps or background scans. This paper addresses these issues by introducing a low-density parity check (LDPC) code and a corresponding code synchronization method suitable for LDPC decoding. Our approach employs a parallel transmitting sequence to achieve synchronization. Notably, the synchronization sequence is transmitted by modulating the luminance of the LED transmitter. Through experimentation, we validate the efficacy of our proposed method in mitigating signal loss.
{"title":"Code Synchronization in Visible Light Communication System Using Dual Orthogonal Rolling Shutter Image Sensors","authors":"Ayumu Otsuka;Zhengqiang Tang;Shan Lu;Takaya Yamazato","doi":"10.23919/comex.2024COL0009","DOIUrl":"https://doi.org/10.23919/comex.2024COL0009","url":null,"abstract":"A visible light communication (VLC) system offers notable advantages, and leveraging image sensors as VLC receivers holds promise. The rolling shutter image sensor stands out as a popular candidate among these sensors. However, challenges arise from signal loss from inter-frame gaps or background scans. This paper addresses these issues by introducing a low-density parity check (LDPC) code and a corresponding code synchronization method suitable for LDPC decoding. Our approach employs a parallel transmitting sequence to achieve synchronization. Notably, the synchronization sequence is transmitted by modulating the luminance of the LED transmitter. Through experimentation, we validate the efficacy of our proposed method in mitigating signal loss.","PeriodicalId":54101,"journal":{"name":"IEICE Communications Express","volume":"13 12","pages":"450-453"},"PeriodicalIF":0.3,"publicationDate":"2024-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10591719","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142761566","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-09DOI: 10.23919/comex.2024XBL0106
Hideya So;Hayato Soya
Spectrum sharing, in which multiple wireless systems share the same radio resources, has been considered to improve frequency utilization efficiency. As a spectrum sharing without control signals, a technique that observes the usage of radio resources, called channel occupation ratio, used by other systems and selects a vacant channel has been considered. However, previous studies have simplified the model of the interfering system, which is different from the real environment. In wireless communications, fluctuations in received power occur due to shadowing caused by the location and the surrounding environment. Previous studies have not clarified the effect of received power fluctuation due to shadowing on observing the occupancy rate. This letter formulates the effects on the observation results of received power fluctuations due to the location of interfering stations and shadowing. Computer simulations with randomly placed interfering stations and shadowing environments show that the proposed formulation almost matches the observed results.
{"title":"Evaluation of Shadowing Effect on Channel Observation for Spectrum Sharing Access","authors":"Hideya So;Hayato Soya","doi":"10.23919/comex.2024XBL0106","DOIUrl":"https://doi.org/10.23919/comex.2024XBL0106","url":null,"abstract":"Spectrum sharing, in which multiple wireless systems share the same radio resources, has been considered to improve frequency utilization efficiency. As a spectrum sharing without control signals, a technique that observes the usage of radio resources, called channel occupation ratio, used by other systems and selects a vacant channel has been considered. However, previous studies have simplified the model of the interfering system, which is different from the real environment. In wireless communications, fluctuations in received power occur due to shadowing caused by the location and the surrounding environment. Previous studies have not clarified the effect of received power fluctuation due to shadowing on observing the occupancy rate. This letter formulates the effects on the observation results of received power fluctuations due to the location of interfering stations and shadowing. Computer simulations with randomly placed interfering stations and shadowing environments show that the proposed formulation almost matches the observed results.","PeriodicalId":54101,"journal":{"name":"IEICE Communications Express","volume":"13 9","pages":"379-383"},"PeriodicalIF":0.3,"publicationDate":"2024-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10591720","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142090747","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Unmanned aerial vehicles (UAVs) are expected to be used in various applications such as delivery services and sensing from airspaces in smart cities. In the future, UAV control systems must address a densely mixed environment comprising various services and users regardless of individuals or businesses. However, users cannot flexibly join or leave the system because of their centralized design. This letter proposes a distributed UAV management system inspired by packet-switched networks, to address dense UAV environments. The proposed system controls autonomous UAVs as packets in packet-switched networks. Each UAV flies along a path composed of links between ground beacon devices as routers. We analyzed the characteristics of the proposed system in dense situations using computer simulation. Simulation results indicate that the proposed system can handle numerous UAVs based on packet-switched networks.
{"title":"A Distributed UAV Management System Inspired by Packet-Switched Networks","authors":"Takahiko Haraguchi;Hiroshi Katada;Taku Yamazaki;Takumi Miyoshi;Ryo Yamamoto;Kiyoshi Ueda","doi":"10.23919/comex.2024XBL0101","DOIUrl":"https://doi.org/10.23919/comex.2024XBL0101","url":null,"abstract":"Unmanned aerial vehicles (UAVs) are expected to be used in various applications such as delivery services and sensing from airspaces in smart cities. In the future, UAV control systems must address a densely mixed environment comprising various services and users regardless of individuals or businesses. However, users cannot flexibly join or leave the system because of their centralized design. This letter proposes a distributed UAV management system inspired by packet-switched networks, to address dense UAV environments. The proposed system controls autonomous UAVs as packets in packet-switched networks. Each UAV flies along a path composed of links between ground beacon devices as routers. We analyzed the characteristics of the proposed system in dense situations using computer simulation. Simulation results indicate that the proposed system can handle numerous UAVs based on packet-switched networks.","PeriodicalId":54101,"journal":{"name":"IEICE Communications Express","volume":"13 9","pages":"389-392"},"PeriodicalIF":0.3,"publicationDate":"2024-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10591721","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142090889","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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