Pub Date : 2024-03-12DOI: 10.23919/comex.2024TCL0002
Yusuke Shida;Satoru Aikawa;Shinichiro Yamamoto
This study explores an advanced method for indoor location estimation leveraging a wireless local area network (WLAN). The integration of round-trip time (RTT), as established by IEEE 802.11mc, has marked a significant advancement in WLANs. This enhancement is pivotal in refining indoor location estimations through multilateration (MLAT) techniques. The RTT, by providing more precise distance measurements between WLAN access points (APs) and users compared to the traditional received signal strength indicator, holds promise for improved accuracy. Nonetheless, in environments with numerous rooms, such as a multi-room floor, the efficacy of MLAT, even with RTT implementation, is not optimal. Addressing this challenge, our paper introduces and validates a novel approach for correcting RTT inaccuracies and a strategic method for selecting APs in MLAT scenarios.
{"title":"Correction of Round-Trip Time and Selection of Access Points for Estimating Wireless LAN Locations by Multilateration","authors":"Yusuke Shida;Satoru Aikawa;Shinichiro Yamamoto","doi":"10.23919/comex.2024TCL0002","DOIUrl":"https://doi.org/10.23919/comex.2024TCL0002","url":null,"abstract":"This study explores an advanced method for indoor location estimation leveraging a wireless local area network (WLAN). The integration of round-trip time (RTT), as established by IEEE 802.11mc, has marked a significant advancement in WLANs. This enhancement is pivotal in refining indoor location estimations through multilateration (MLAT) techniques. The RTT, by providing more precise distance measurements between WLAN access points (APs) and users compared to the traditional received signal strength indicator, holds promise for improved accuracy. Nonetheless, in environments with numerous rooms, such as a multi-room floor, the efficacy of MLAT, even with RTT implementation, is not optimal. Addressing this challenge, our paper introduces and validates a novel approach for correcting RTT inaccuracies and a strategic method for selecting APs in MLAT scenarios.","PeriodicalId":54101,"journal":{"name":"IEICE Communications Express","volume":"13 8","pages":"290-294"},"PeriodicalIF":0.3,"publicationDate":"2024-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10471243","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141973492","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 : 2024-03-12DOI: 10.23919/comex.2024SPL0013
Mangseang Hor;Takashi Hikage
This paper introduces a newly designed X-shaped slot antenna with high gain and wideband characteristics for use in mm-wave frequency band. The X-shaped slot antenna serves as radiating elements of planar array configuration for high gain. The 4×4 configuration is investigated in this paper. According to simulation results, the 4×4 planar array exhibits a −9.7 dB impedance bandwidth within the range of 26.1-31 GHz and a maximum gain of 18.2 dBi. Furthermore, gain and bandwidth enhancement of the array antenna is studied. As the results, the antenna shows an impedance bandwidth within the range of 25.35–25.95 GHz, and 26.8–30.2 GHz. Within this band the antenna realized gain is ranging from 17.5–20 dBi.
{"title":"A Study on Gain and Bandwidth Enhancement of 4×4 Planar Array of X-Shaped Slot Antenna within Millimeter Wave Frequency Band","authors":"Mangseang Hor;Takashi Hikage","doi":"10.23919/comex.2024SPL0013","DOIUrl":"https://doi.org/10.23919/comex.2024SPL0013","url":null,"abstract":"This paper introduces a newly designed X-shaped slot antenna with high gain and wideband characteristics for use in mm-wave frequency band. The X-shaped slot antenna serves as radiating elements of planar array configuration for high gain. The 4×4 configuration is investigated in this paper. According to simulation results, the 4×4 planar array exhibits a −9.7 dB impedance bandwidth within the range of 26.1-31 GHz and a maximum gain of 18.2 dBi. Furthermore, gain and bandwidth enhancement of the array antenna is studied. As the results, the antenna shows an impedance bandwidth within the range of 25.35–25.95 GHz, and 26.8–30.2 GHz. Within this band the antenna realized gain is ranging from 17.5–20 dBi.","PeriodicalId":54101,"journal":{"name":"IEICE Communications Express","volume":"13 6","pages":"176-180"},"PeriodicalIF":0.3,"publicationDate":"2024-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10471241","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141245284","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 : 2024-03-12DOI: 10.23919/comex.2024XBL0018
Yasutaka Kimura;Naotaka Shibata;Shin Kaneko;Jun-Ichi Kani;Tomoaki Yoshida
We demonstrate an extended ROADM architecture with remote TRx control and a turn-back function that enables end-to-end direct optical connections covering access. The acceptable access loss of the turn-back path is within 3–19 dB, thus meeting the requirements of the class-S optical access infrastructure.
我们展示了一种具有远程 TRx 控制和回转功能的扩展 ROADM 架构，该架构可实现覆盖接入的端到端直接光连接。回转路径的可接受接入损耗在 3-19 dB 范围内，从而满足了 S 类光接入基础设施的要求。
{"title":"Demonstration of Extended ROADM Architecture to Enable End-to-End Optical Connections with Covering Class-S Access Infrastructure","authors":"Yasutaka Kimura;Naotaka Shibata;Shin Kaneko;Jun-Ichi Kani;Tomoaki Yoshida","doi":"10.23919/comex.2024XBL0018","DOIUrl":"https://doi.org/10.23919/comex.2024XBL0018","url":null,"abstract":"We demonstrate an extended ROADM architecture with remote TRx control and a turn-back function that enables end-to-end direct optical connections covering access. The acceptable access loss of the turn-back path is within 3–19 dB, thus meeting the requirements of the class-S optical access infrastructure.","PeriodicalId":54101,"journal":{"name":"IEICE Communications Express","volume":"13 5","pages":"156-158"},"PeriodicalIF":0.3,"publicationDate":"2024-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10471270","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140647910","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}
High-altitude platform stations (HAPSs) have the potential to expand the coverage of sixth-generation mobile communication systems, and several international mobile telecommunications (IMT) bands below 2.7 GHz have already been identified for HAPS service links. Because of the limited frequency resources, spectrum sharing techniques are needed to ensure that HAPSs can coexist with terrestrial base stations (BSs), but this means that a HAPS may interfere with the connection of terrestrial BS users within its line of sight. This letter proposes a scheme that combines an interference canceler and enhanced inter-cell interference coordination to reduce interference in an integrated HAPS-terrestrial system. Numerical simulations demonstrated that the integrated system greatly improved the signal-to-interference-plus-noise ratio of terrestrial BSs and improved the system capacity by 26% compared to a conventional system with no interference reduction.
{"title":"Spectrum Sharing in Integrated HAPS and Terrestrial Systems Using an Interference Canceler and Coordination","authors":"Tsutomu Ishikawa;Koji Tashiro;Mitsukuni Konishi;Kenji Hoshino","doi":"10.23919/comex.2024SPL0019","DOIUrl":"https://doi.org/10.23919/comex.2024SPL0019","url":null,"abstract":"High-altitude platform stations (HAPSs) have the potential to expand the coverage of sixth-generation mobile communication systems, and several international mobile telecommunications (IMT) bands below 2.7 GHz have already been identified for HAPS service links. Because of the limited frequency resources, spectrum sharing techniques are needed to ensure that HAPSs can coexist with terrestrial base stations (BSs), but this means that a HAPS may interfere with the connection of terrestrial BS users within its line of sight. This letter proposes a scheme that combines an interference canceler and enhanced inter-cell interference coordination to reduce interference in an integrated HAPS-terrestrial system. Numerical simulations demonstrated that the integrated system greatly improved the signal-to-interference-plus-noise ratio of terrestrial BSs and improved the system capacity by 26% compared to a conventional system with no interference reduction.","PeriodicalId":54101,"journal":{"name":"IEICE Communications Express","volume":"13 6","pages":"185-189"},"PeriodicalIF":0.3,"publicationDate":"2024-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10471240","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141245283","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}
This study evaluates an extended Berkeley Packet Filter (eBPF)-based network failure prediction method using Autogluon-Tabular to process the fine-grained network information extracted by eBPF. The extracted information is considered as input features of the proposed model, which aims to predict the subsequent packet loss and determine a network failure event before it causes a huge impact. Supervised learning and semi-supervised learning are both adopted in Autogluon. The accuracy and detection time are evaluated as the main criteria. Simulation results show that F1 scores exceed 0.9 for our proposed method, and the proposed method can achieve prediction for potential failure events within 30 and 40 seconds when symptoms such as packet loss occur.
{"title":"Evaluation on eBPF-Based Network Failure Prediction Using AutoGluon","authors":"Tianhao Zhu;Jiwon Lee;Bojian Du;Ryoma Kondo;Kentaro Matsuura;Hiroyuki Morikawa;Yoshiaki Narusue","doi":"10.23919/comex.2023XBL0183","DOIUrl":"https://doi.org/10.23919/comex.2023XBL0183","url":null,"abstract":"This study evaluates an extended Berkeley Packet Filter (eBPF)-based network failure prediction method using Autogluon-Tabular to process the fine-grained network information extracted by eBPF. The extracted information is considered as input features of the proposed model, which aims to predict the subsequent packet loss and determine a network failure event before it causes a huge impact. Supervised learning and semi-supervised learning are both adopted in Autogluon. The accuracy and detection time are evaluated as the main criteria. Simulation results show that F1 scores exceed 0.9 for our proposed method, and the proposed method can achieve prediction for potential failure events within 30 and 40 seconds when symptoms such as packet loss occur.","PeriodicalId":54101,"journal":{"name":"IEICE Communications Express","volume":"13 5","pages":"159-162"},"PeriodicalIF":0.3,"publicationDate":"2024-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10471268","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140647939","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 : 2024-03-12DOI: 10.23919/comex.2024TCL0010
Togo Shinomiya;Satoru Aikawa;Shinichiro Yamamoto
This study discusses an indoor localization method using the radio signal strength indicator (RSSI) of a wireless local area network (LAN). An indoor localization method that adapts a convolutional neural network (CNN) to the fingerprint method is used. In this method, the CNN learns the access point (AP) information for each coordinate using the RSSI and media access control (MAC) addresses obtained from the wireless LAN APs and compares them with the AP information received from the user to estimate the user location. However, data collection for learning is costly when using CNNs. In addition, there is a problem of missing data owing to various factors when collecting AP information. Therefore, data augmentation is proposed as a method to reduce the cost of data collection while maintaining accuracy and is performed after correcting for missing values. However, data augmentation can produce unrealistic data. This paper proposes a method for correcting missing values in measurement data as a solution to this problem.
{"title":"Fingerprint Localization Scheme with Correction for Missing Values in Training Data and Data Augmentation","authors":"Togo Shinomiya;Satoru Aikawa;Shinichiro Yamamoto","doi":"10.23919/comex.2024TCL0010","DOIUrl":"https://doi.org/10.23919/comex.2024TCL0010","url":null,"abstract":"This study discusses an indoor localization method using the radio signal strength indicator (RSSI) of a wireless local area network (LAN). An indoor localization method that adapts a convolutional neural network (CNN) to the fingerprint method is used. In this method, the CNN learns the access point (AP) information for each coordinate using the RSSI and media access control (MAC) addresses obtained from the wireless LAN APs and compares them with the AP information received from the user to estimate the user location. However, data collection for learning is costly when using CNNs. In addition, there is a problem of missing data owing to various factors when collecting AP information. Therefore, data augmentation is proposed as a method to reduce the cost of data collection while maintaining accuracy and is performed after correcting for missing values. However, data augmentation can produce unrealistic data. This paper proposes a method for correcting missing values in measurement data as a solution to this problem.","PeriodicalId":54101,"journal":{"name":"IEICE Communications Express","volume":"13 8","pages":"295-298"},"PeriodicalIF":0.3,"publicationDate":"2024-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10471267","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141973487","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 : 2024-03-12DOI: 10.23919/comex.2024XBL0003
Yuma Nishimura;Wataru Chujo;Kentaro Kobayashi
Research on high-throughput optical wireless communication (OWC) has been progressing toward sixth generation. As half-power beam width of near-infrared 600 Mbps light emitting diode backhaul (LEDBH) consisting of LED and photodiode is narrow, high-precision optical axis alignment of LEDBH is important. So far, the optical axis was manually aligned using a scope. In this study, object detection using deep learning, YOLOv7, is adapted to automatically align the optical axis. Average precisions of LEDBH detection are evaluated in lighting surroundings while changing the camera exposure time. The optical axis is finely adjusted with object detection and mechanical angle adjustment.
{"title":"High-Precision Automatic Optical Axis Alignment of LED Backhaul in Lighting Surroundings Based on Object Detection","authors":"Yuma Nishimura;Wataru Chujo;Kentaro Kobayashi","doi":"10.23919/comex.2024XBL0003","DOIUrl":"https://doi.org/10.23919/comex.2024XBL0003","url":null,"abstract":"Research on high-throughput optical wireless communication (OWC) has been progressing toward sixth generation. As half-power beam width of near-infrared 600 Mbps light emitting diode backhaul (LEDBH) consisting of LED and photodiode is narrow, high-precision optical axis alignment of LEDBH is important. So far, the optical axis was manually aligned using a scope. In this study, object detection using deep learning, YOLOv7, is adapted to automatically align the optical axis. Average precisions of LEDBH detection are evaluated in lighting surroundings while changing the camera exposure time. The optical axis is finely adjusted with object detection and mechanical angle adjustment.","PeriodicalId":54101,"journal":{"name":"IEICE Communications Express","volume":"13 5","pages":"151-155"},"PeriodicalIF":0.3,"publicationDate":"2024-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10471269","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140647940","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 : 2024-03-12DOI: 10.23919/comex.2024XBL0025
Kazumitsu Sakamoto;Yosuke Fujino
In a 920-MHz band Internet-of-Things (IoT) platform via a low Earth orbit satellite, signal collisions frequently occur between the desired satellite IoT (S-IoT) terminals and interference from terrestrial IoT (T-IoT) terminals accommodated in the T-IoT platform. In this letter, computer simulation is used to evaluate the capacity for S-IoT terminals per satellite that can be achieved by applying minimum mean squared error receiver beamforming in each case of using low power wide area terminals of LoRa, Sigfox, and ELTRES. The results show that a satellite can accommodate 1 million-order terminals by using multiple channels in the 920-MHz band.
{"title":"Channel Capacity Evaluation of 920-MHz Band IoT Platform via LEO Satellite","authors":"Kazumitsu Sakamoto;Yosuke Fujino","doi":"10.23919/comex.2024XBL0025","DOIUrl":"https://doi.org/10.23919/comex.2024XBL0025","url":null,"abstract":"In a 920-MHz band Internet-of-Things (IoT) platform via a low Earth orbit satellite, signal collisions frequently occur between the desired satellite IoT (S-IoT) terminals and interference from terrestrial IoT (T-IoT) terminals accommodated in the T-IoT platform. In this letter, computer simulation is used to evaluate the capacity for S-IoT terminals per satellite that can be achieved by applying minimum mean squared error receiver beamforming in each case of using low power wide area terminals of LoRa, Sigfox, and ELTRES. The results show that a satellite can accommodate 1 million-order terminals by using multiple channels in the 920-MHz band.","PeriodicalId":54101,"journal":{"name":"IEICE Communications Express","volume":"13 5","pages":"163-166"},"PeriodicalIF":0.3,"publicationDate":"2024-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10471245","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140647872","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}
This article proposes a millimeter-wave fast beam tracking algorithm for moving vehicles, considering a geometry of road environment. Focusing on the fact that vehicle movement is constrained on roads, horizontal and vertical beam directions are determined based on obtainable driving direction and road shape. In addition, we perform a two-pattern beam selection for the vehicle's forward and rearward directions to estimate the beam tracking speed. By conducting simulations using SUMO, which emulates vehicle movement on various roads, we verified the effective operation of the proposed scheme and confirmed its superiority over the existing beam sweeping approach.
{"title":"Location-Aided Fast Beam Tracking Algorithm for Millimeter-Wave V2I","authors":"Sojin Ozawa;Tokio Ikuta;Yuki Sasaki;Ryo Iwaki;Jin Nakazato;Manabu Tsukada;Hideya So;Kazuki Maruta","doi":"10.23919/comex.2024XBL0001","DOIUrl":"https://doi.org/10.23919/comex.2024XBL0001","url":null,"abstract":"This article proposes a millimeter-wave fast beam tracking algorithm for moving vehicles, considering a geometry of road environment. Focusing on the fact that vehicle movement is constrained on roads, horizontal and vertical beam directions are determined based on obtainable driving direction and road shape. In addition, we perform a two-pattern beam selection for the vehicle's forward and rearward directions to estimate the beam tracking speed. By conducting simulations using SUMO, which emulates vehicle movement on various roads, we verified the effective operation of the proposed scheme and confirmed its superiority over the existing beam sweeping approach.","PeriodicalId":54101,"journal":{"name":"IEICE Communications Express","volume":"13 5","pages":"146-150"},"PeriodicalIF":0.3,"publicationDate":"2024-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10471239","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140647941","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 : 2024-03-09DOI: 10.23919/comex.2024XBL0061
Tatsunori Saito;Yaokun Hu;Takeshi Toda
We proposed a phase accumulation to improve the SNR and accuracy on remote heartrate measurement based on multiple chirps mm-wave FMCW radar. However, specification of radar module has continued to be upgraded and it has become clear that increasing number of the accumulative phases may actually worsen the heartrate estimation accuracy, depending on subject and time of experiment. Therefore, this article proposes adaptive adjusting accumulative number of phases, for remote heartrate measurement based on mm-wave multiple chirps FMCW radar. The method adaptively adjusts accumulative number of phases of the received multiple chirps in each observation window according to a SNR criterion. Experimental result shows effect of the proposed method compared with single chirp and 32-phase accumulated cases, for eight subjects.
{"title":"A Study on Adaptively Adjusting Phases Accumulative Number for Remote Heart-Rate Sensing with mm-wave Multi-Chirp FMCW Radar","authors":"Tatsunori Saito;Yaokun Hu;Takeshi Toda","doi":"10.23919/comex.2024XBL0061","DOIUrl":"https://doi.org/10.23919/comex.2024XBL0061","url":null,"abstract":"We proposed a phase accumulation to improve the SNR and accuracy on remote heartrate measurement based on multiple chirps mm-wave FMCW radar. However, specification of radar module has continued to be upgraded and it has become clear that increasing number of the accumulative phases may actually worsen the heartrate estimation accuracy, depending on subject and time of experiment. Therefore, this article proposes adaptive adjusting accumulative number of phases, for remote heartrate measurement based on mm-wave multiple chirps FMCW radar. The method adaptively adjusts accumulative number of phases of the received multiple chirps in each observation window according to a SNR criterion. Experimental result shows effect of the proposed method compared with single chirp and 32-phase accumulated cases, for eight subjects.","PeriodicalId":54101,"journal":{"name":"IEICE Communications Express","volume":"13 7","pages":"248-251"},"PeriodicalIF":0.3,"publicationDate":"2024-03-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10528237","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141583514","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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