Pub Date : 2020-09-14DOI: 10.1109/AMC44022.2020.9244368
Maksim V. Faronov, I. Polushin
The problems of regulation of penetration rate and drilling power in rotary drilling systems are addressed. Regulation algorithms are proposed which do not require knowledge of majority of the parameters of the drilling systems and those of the rock-bit interaction. The algorithms are designed using a two-step process, where first the target angular velocity is generated using the speed-gradient control algorithms, and subsequently tracking of the target angular velocity is achieved using tracking and disturbance rejection scheme. Simulation results are presented which illustrate the efficiency of the proposed control design.
{"title":"Regulation of Penetration Rate and Drilling Power in Rotary Drilling Systems","authors":"Maksim V. Faronov, I. Polushin","doi":"10.1109/AMC44022.2020.9244368","DOIUrl":"https://doi.org/10.1109/AMC44022.2020.9244368","url":null,"abstract":"The problems of regulation of penetration rate and drilling power in rotary drilling systems are addressed. Regulation algorithms are proposed which do not require knowledge of majority of the parameters of the drilling systems and those of the rock-bit interaction. The algorithms are designed using a two-step process, where first the target angular velocity is generated using the speed-gradient control algorithms, and subsequently tracking of the target angular velocity is achieved using tracking and disturbance rejection scheme. Simulation results are presented which illustrate the efficiency of the proposed control design.","PeriodicalId":427681,"journal":{"name":"2020 IEEE 16th International Workshop on Advanced Motion Control (AMC)","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134624694","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 : 2020-09-14DOI: 10.1109/AMC44022.2020.9244314
D. Chugo, Masahiro Yokota, S. Muramatsu, S. Yokota, Jinhua She, H. Hashimoto, Takahiro Katayama, Yasuhide Mizuta, Atsushi Koujina
This paper proposes a novel standing assistance robot, which considers the posture tolerance of its user. In previous studies, conventional assistive robots did not require patients to use their own physical strength to stand, which leads to decreased strength in the elderly. Therefore, an assistive robot that allows patients to maximally use the physical strength they possess is required. To realize this objective, it is important that a robot assists patients according to their body movement and by their intentions. However, in previous studies, general assistive robots helped patients by using a fixed motion reference pathway in spite of their original intention, and as a result, these robots failed to use the physical strength of the patients. In our previous study, we investigated the posture tolerance during a standing motion. In this tolerance, patients could stand by own muscle strength with stable posture. Thus, as the next step, this paper proposes assistance force control scheme which considers the investigated posture tolerance. Our robot generated assistance force, which lead the voluntary movement with their remaining physical strength within investigated range, by combining position control and force control. A prototype assistive robot, based on the proposed idea was fabricated to help patients stand up safely using the maximum of their remaining physical strength.
{"title":"Standing Assistance Control based on Voluntary Body Movement within Safety Tolerance","authors":"D. Chugo, Masahiro Yokota, S. Muramatsu, S. Yokota, Jinhua She, H. Hashimoto, Takahiro Katayama, Yasuhide Mizuta, Atsushi Koujina","doi":"10.1109/AMC44022.2020.9244314","DOIUrl":"https://doi.org/10.1109/AMC44022.2020.9244314","url":null,"abstract":"This paper proposes a novel standing assistance robot, which considers the posture tolerance of its user. In previous studies, conventional assistive robots did not require patients to use their own physical strength to stand, which leads to decreased strength in the elderly. Therefore, an assistive robot that allows patients to maximally use the physical strength they possess is required. To realize this objective, it is important that a robot assists patients according to their body movement and by their intentions. However, in previous studies, general assistive robots helped patients by using a fixed motion reference pathway in spite of their original intention, and as a result, these robots failed to use the physical strength of the patients. In our previous study, we investigated the posture tolerance during a standing motion. In this tolerance, patients could stand by own muscle strength with stable posture. Thus, as the next step, this paper proposes assistance force control scheme which considers the investigated posture tolerance. Our robot generated assistance force, which lead the voluntary movement with their remaining physical strength within investigated range, by combining position control and force control. A prototype assistive robot, based on the proposed idea was fabricated to help patients stand up safely using the maximum of their remaining physical strength.","PeriodicalId":427681,"journal":{"name":"2020 IEEE 16th International Workshop on Advanced Motion Control (AMC)","volume":"49 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116287382","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 : 2020-09-14DOI: 10.1109/AMC44022.2020.9244442
Petter H. Gøytil, D. Padovani
Electrohydrostatic actuation is an emerging technology combining the advantages of hydraulic and electric actuation, resulting in energy efficient solutions that appear electric from the outside while hydraulic on the inside. Conventional solutions, however, significantly reduce the natural frequency of the system compared to traditional hydraulic actuators. This may result in considerable loss of performance under feedback control. In this paper, a simple modification for increasing the natural frequency of the system involving a high-pressure accumulator is proposed and investigated. Theoretical analysis demonstrates the potential for considerable improvements using the proposed solution, resulting in higher natural frequencies and improved performance. The results are verified by numerical simulation.
{"title":"Motion Control of Large Inertia Loads Using Electrohydrostatic Actuation","authors":"Petter H. Gøytil, D. Padovani","doi":"10.1109/AMC44022.2020.9244442","DOIUrl":"https://doi.org/10.1109/AMC44022.2020.9244442","url":null,"abstract":"Electrohydrostatic actuation is an emerging technology combining the advantages of hydraulic and electric actuation, resulting in energy efficient solutions that appear electric from the outside while hydraulic on the inside. Conventional solutions, however, significantly reduce the natural frequency of the system compared to traditional hydraulic actuators. This may result in considerable loss of performance under feedback control. In this paper, a simple modification for increasing the natural frequency of the system involving a high-pressure accumulator is proposed and investigated. Theoretical analysis demonstrates the potential for considerable improvements using the proposed solution, resulting in higher natural frequencies and improved performance. The results are verified by numerical simulation.","PeriodicalId":427681,"journal":{"name":"2020 IEEE 16th International Workshop on Advanced Motion Control (AMC)","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122227803","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 : 2020-09-14DOI: 10.1109/AMC44022.2020.9244428
Xiaobai Sun, T. Nozaki, T. Murakami, K. Ohnishi
This paper presents a novel method to identify a target object based on position and force data during motion demonstration. MCS is a system that copy and reproduce a skillful human motion through bilateral teleoperation. Even though, MSC can teach a robot how to move, a robot cannot recognize a target object because conventional MCS does not record environmental information. In proposed system, a camera is used to add environmental information. We use object detection algorithm to detect not a target object but a robot itself. The detected robot area is used to combine manipulator's information in image space and in robotic work space. By checking detected robot area and haptic information, we can obtain a region around a target object automatically. After automatic target image data collection, we train Convolutional Auto Encoder(CAE) so that CAE can extract target information. The proposed neural network can selectively detect the target object for MCS, which means a robot understand a target for MCS. The results of end effectors' detection and target object extraction are shown in images through experiments.
提出了一种基于运动演示过程中位置和力数据的目标物体识别方法。MCS是一种通过双侧遥操作复制和再现熟练的人体动作的系统。尽管MSC可以教机器人如何移动，但机器人无法识别目标物体，因为传统的MCS不记录环境信息。在该系统中，使用摄像机添加环境信息。我们使用目标检测算法来检测的不是目标物体，而是机器人本身。利用检测到的机器人区域将图像空间和机器人工作空间中的机械手信息结合起来。通过检测到的机器人区域和触觉信息，自动获得目标物体周围的区域。在自动采集目标图像数据后，对卷积自动编码器(Convolutional Auto Encoder, CAE)进行训练，使其能够提取目标信息。提出的神经网络可以选择性地检测MCS的目标物体，这意味着机器人可以理解MCS的目标。通过实验，将末端执行器检测和目标物体提取的结果以图像的形式显示出来。
{"title":"A Method to Make a Robot Understand What was a Target Object in Motion Copying System","authors":"Xiaobai Sun, T. Nozaki, T. Murakami, K. Ohnishi","doi":"10.1109/AMC44022.2020.9244428","DOIUrl":"https://doi.org/10.1109/AMC44022.2020.9244428","url":null,"abstract":"This paper presents a novel method to identify a target object based on position and force data during motion demonstration. MCS is a system that copy and reproduce a skillful human motion through bilateral teleoperation. Even though, MSC can teach a robot how to move, a robot cannot recognize a target object because conventional MCS does not record environmental information. In proposed system, a camera is used to add environmental information. We use object detection algorithm to detect not a target object but a robot itself. The detected robot area is used to combine manipulator's information in image space and in robotic work space. By checking detected robot area and haptic information, we can obtain a region around a target object automatically. After automatic target image data collection, we train Convolutional Auto Encoder(CAE) so that CAE can extract target information. The proposed neural network can selectively detect the target object for MCS, which means a robot understand a target for MCS. The results of end effectors' detection and target object extraction are shown in images through experiments.","PeriodicalId":427681,"journal":{"name":"2020 IEEE 16th International Workshop on Advanced Motion Control (AMC)","volume":"139 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124885967","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 : 2020-09-14DOI: 10.1109/AMC44022.2020.9244310
Kunal Iyer, Barys Shyrokau, V. Ivanov
This paper provides an analysis of methods used in automotive control applications for finding the tyre forces. An attention is given to three main classes of relevant methods: tyre-model-based, tyre-model-free, and sensor-based. After analysis of advantages and disadvantages of each class, an original application of the approach based on locally weighted projection regression (LWPR) is discussed. This approach can find combined use for both model-free and sensor-based tyre force reconstruction.
{"title":"Offline and Online Tyre Model Reconstruction by Locally Weighted Projection Regression","authors":"Kunal Iyer, Barys Shyrokau, V. Ivanov","doi":"10.1109/AMC44022.2020.9244310","DOIUrl":"https://doi.org/10.1109/AMC44022.2020.9244310","url":null,"abstract":"This paper provides an analysis of methods used in automotive control applications for finding the tyre forces. An attention is given to three main classes of relevant methods: tyre-model-based, tyre-model-free, and sensor-based. After analysis of advantages and disadvantages of each class, an original application of the approach based on locally weighted projection regression (LWPR) is discussed. This approach can find combined use for both model-free and sensor-based tyre force reconstruction.","PeriodicalId":427681,"journal":{"name":"2020 IEEE 16th International Workshop on Advanced Motion Control (AMC)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127127757","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 : 2020-09-14DOI: 10.1109/AMC44022.2020.9244427
Bastiaan Vandewal, Joris Gillis, Erwin Rademakers, G. Pipeleers, J. Swevers
This paper presents a motion planning approach, Local Spline Relaxation with Local Hyperplanes (LSR-LH), for autonomous vehicles to search for time-optimal collision-free motion trajectories through environments with stationary and dynamic convex obstacles. These trajectories are piecewisely parameterized as a fourth order polynomial based on Runge-Kutta's fourth order integration scheme. Collision-free trajectories are guaranteed by defining separating hyperplanes between obstacles and the continuous time trajectory of the vehicle. An optimal control problem is solved with a receding horizon to include the latest information of the environment and to take into account model mismatches. Extensive numerical simulations are performed to show the potential of the method.
{"title":"Obstacle Avoidance in Path Following using Local Spline Relaxation","authors":"Bastiaan Vandewal, Joris Gillis, Erwin Rademakers, G. Pipeleers, J. Swevers","doi":"10.1109/AMC44022.2020.9244427","DOIUrl":"https://doi.org/10.1109/AMC44022.2020.9244427","url":null,"abstract":"This paper presents a motion planning approach, Local Spline Relaxation with Local Hyperplanes (LSR-LH), for autonomous vehicles to search for time-optimal collision-free motion trajectories through environments with stationary and dynamic convex obstacles. These trajectories are piecewisely parameterized as a fourth order polynomial based on Runge-Kutta's fourth order integration scheme. Collision-free trajectories are guaranteed by defining separating hyperplanes between obstacles and the continuous time trajectory of the vehicle. An optimal control problem is solved with a receding horizon to include the latest information of the environment and to take into account model mismatches. Extensive numerical simulations are performed to show the potential of the method.","PeriodicalId":427681,"journal":{"name":"2020 IEEE 16th International Workshop on Advanced Motion Control (AMC)","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122825306","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 : 2020-09-14DOI: 10.1109/amc44022.2020.9244422
{"title":"Impedance and Force Control","authors":"","doi":"10.1109/amc44022.2020.9244422","DOIUrl":"https://doi.org/10.1109/amc44022.2020.9244422","url":null,"abstract":"","PeriodicalId":427681,"journal":{"name":"2020 IEEE 16th International Workshop on Advanced Motion Control (AMC)","volume":"86 4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123287505","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 : 2020-09-14DOI: 10.1109/AMC44022.2020.9244335
Sakahisa Nagai, A. Kawamura
This study aims to realize a tactile display which is constructed by arranging a lot of compact linear actuators on a plane and can represent 2D haptic information by controlling their position and force. In our previous works, a compact dual solenoid actuator (CDSA) was developed which can be controlled by sensorless position estimation technique. However, the frequency range of the accurate position control is narrow (less than 2.0 Hz). This paper proposes a compact linear actuator which is consists of a DC motor, planetary gear, and cylindrical cam. A rotary encoder which does not increase the horizontal cross section area is attached to obtain the position information. The lift angle of the cylindrical cam is designed as π/4 to achieve high backdrivability. Experiments of position control with a disturbance observer were conducted to confirm the control performance. As a result, when the frequency of the position command was less than 20 Hz, the accurate position control was achieved, whose gain was within plus or minus 1 dB. Therefore, the frequency range could be enhanced compared with the CDSA. This actuator is very useful because the actuator can be applied not only in haptic applications but also other applications such as human support in narrow space.
{"title":"Development of Compact Linear Actuator Combining DC motor and Cylindrical Cam for Tactile Display","authors":"Sakahisa Nagai, A. Kawamura","doi":"10.1109/AMC44022.2020.9244335","DOIUrl":"https://doi.org/10.1109/AMC44022.2020.9244335","url":null,"abstract":"This study aims to realize a tactile display which is constructed by arranging a lot of compact linear actuators on a plane and can represent 2D haptic information by controlling their position and force. In our previous works, a compact dual solenoid actuator (CDSA) was developed which can be controlled by sensorless position estimation technique. However, the frequency range of the accurate position control is narrow (less than 2.0 Hz). This paper proposes a compact linear actuator which is consists of a DC motor, planetary gear, and cylindrical cam. A rotary encoder which does not increase the horizontal cross section area is attached to obtain the position information. The lift angle of the cylindrical cam is designed as π/4 to achieve high backdrivability. Experiments of position control with a disturbance observer were conducted to confirm the control performance. As a result, when the frequency of the position command was less than 20 Hz, the accurate position control was achieved, whose gain was within plus or minus 1 dB. Therefore, the frequency range could be enhanced compared with the CDSA. This actuator is very useful because the actuator can be applied not only in haptic applications but also other applications such as human support in narrow space.","PeriodicalId":427681,"journal":{"name":"2020 IEEE 16th International Workshop on Advanced Motion Control (AMC)","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123120798","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 : 2020-09-14DOI: 10.1109/AMC44022.2020.9244329
Kentaro Yokota, H. Fujimoto, Y. Hori
Research and development have been very active in electric airplanes (EAs). EAs use electric motors as the power source; therefore, EAs are expected to achieve more secure, more efficient, and more eco-friendly aviation. The conventional airplanes use mechanic air brakes such as spoilers to adjust the descent angle; however, they are difficult to control even for a skilled pilot. Previous research showed that electric motors enable EAs to regenerate their potential energy while descending as the windmilling propeller produces negative torque and thrust. This negative thrust works as a substitute air brake, called regenerative air brake. This paper proposes the thrust control method of regenerative air brake for automatic descent. Furthermore, the observer-based thrust estimation method is also proposed since adding force sensors decreases the stiffness of the thrusters. The effectiveness of the proposed method is verified by simulations and experiments in the wind tunnel.
{"title":"Basic Study on Regenerative Air Brake Using Observer-based Thrust Control for Electric Airplane","authors":"Kentaro Yokota, H. Fujimoto, Y. Hori","doi":"10.1109/AMC44022.2020.9244329","DOIUrl":"https://doi.org/10.1109/AMC44022.2020.9244329","url":null,"abstract":"Research and development have been very active in electric airplanes (EAs). EAs use electric motors as the power source; therefore, EAs are expected to achieve more secure, more efficient, and more eco-friendly aviation. The conventional airplanes use mechanic air brakes such as spoilers to adjust the descent angle; however, they are difficult to control even for a skilled pilot. Previous research showed that electric motors enable EAs to regenerate their potential energy while descending as the windmilling propeller produces negative torque and thrust. This negative thrust works as a substitute air brake, called regenerative air brake. This paper proposes the thrust control method of regenerative air brake for automatic descent. Furthermore, the observer-based thrust estimation method is also proposed since adding force sensors decreases the stiffness of the thrusters. The effectiveness of the proposed method is verified by simulations and experiments in the wind tunnel.","PeriodicalId":427681,"journal":{"name":"2020 IEEE 16th International Workshop on Advanced Motion Control (AMC)","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132015835","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 : 2020-09-14DOI: 10.1109/AMC44022.2020.9244431
N. Motoi, Shoki Nakamura
This paper described the remote control method with the tactile sensation for the underwater robot. The remote control system for the underwater robot consists of the master system in the atmosphere and slave system in water. The wearable passive device which consists of the constant torque spring, and the powder brake is used as the master system. This device is designed based on the fingertip motion, and it is expected to improve the operability. On the other hand, the underwater manipulator with the module structure is used as the slave system. This manipulator has the water-proof property by using the magnetic coupling. The structure and driven system between the master and slave systems are different. In addition, the master device generates the only passive force like the braking force. Therefore, the only essential information for the realization of the remote control is extracted and used. In this paper, the position information is sent from the master system to the slave system, and the force information is transmitted from the slave system to the master system. From the experimental results, the validity of the proposed method was confirmed.
{"title":"Remote Control Method with Tactile Sensation for Underwater Robot with Magnetic Coupling","authors":"N. Motoi, Shoki Nakamura","doi":"10.1109/AMC44022.2020.9244431","DOIUrl":"https://doi.org/10.1109/AMC44022.2020.9244431","url":null,"abstract":"This paper described the remote control method with the tactile sensation for the underwater robot. The remote control system for the underwater robot consists of the master system in the atmosphere and slave system in water. The wearable passive device which consists of the constant torque spring, and the powder brake is used as the master system. This device is designed based on the fingertip motion, and it is expected to improve the operability. On the other hand, the underwater manipulator with the module structure is used as the slave system. This manipulator has the water-proof property by using the magnetic coupling. The structure and driven system between the master and slave systems are different. In addition, the master device generates the only passive force like the braking force. Therefore, the only essential information for the realization of the remote control is extracted and used. In this paper, the position information is sent from the master system to the slave system, and the force information is transmitted from the slave system to the master system. From the experimental results, the validity of the proposed method was confirmed.","PeriodicalId":427681,"journal":{"name":"2020 IEEE 16th International Workshop on Advanced Motion Control (AMC)","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128682914","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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