Pub Date : 2012-03-25DOI: 10.1109/AMC.2012.6197025
Yoshiyuki Hatta, T. Shimono, N. Motoi
In recent years, haptic communication with teleoperation systems has been actively researched. One of the effective methods for haptic communication is bilateral motion control based on acceleration control. If the acceleration-based bilateral control is applied to a parallel multi-degrees-of-freedom (MDOF) system, complicated haptic human motion can be realized in the remote site. However it is difficult to understand whole motion of the system based only on information of each actuator. One of the effective methods for the motion recognition is modal decomposition based on Discrete Fourier series expansion (DFS). This modal decomposition is effective for the analysis of motion of parallel MDOF systems. However, in order to apply the modal decomposition, it is necessary that an arrangement of the parallel MDOF system is known. This paper proposes an arrangement identification method for parallel MDOF teleoperation systems based on Levenberg-Marquardt (LM) method. The method can estimate the arrangement, even if there is no visual information. Finally, the validity of the proposed method is confirmed by the experimental results.
{"title":"An arrangement identification method for parallel multi-degrees-of-freedom teleoperation systems based on Levenberg-Marquardt method","authors":"Yoshiyuki Hatta, T. Shimono, N. Motoi","doi":"10.1109/AMC.2012.6197025","DOIUrl":"https://doi.org/10.1109/AMC.2012.6197025","url":null,"abstract":"In recent years, haptic communication with teleoperation systems has been actively researched. One of the effective methods for haptic communication is bilateral motion control based on acceleration control. If the acceleration-based bilateral control is applied to a parallel multi-degrees-of-freedom (MDOF) system, complicated haptic human motion can be realized in the remote site. However it is difficult to understand whole motion of the system based only on information of each actuator. One of the effective methods for the motion recognition is modal decomposition based on Discrete Fourier series expansion (DFS). This modal decomposition is effective for the analysis of motion of parallel MDOF systems. However, in order to apply the modal decomposition, it is necessary that an arrangement of the parallel MDOF system is known. This paper proposes an arrangement identification method for parallel MDOF teleoperation systems based on Levenberg-Marquardt (LM) method. The method can estimate the arrangement, even if there is no visual information. Finally, the validity of the proposed method is confirmed by the experimental results.","PeriodicalId":6439,"journal":{"name":"2012 12th IEEE International Workshop on Advanced Motion Control (AMC)","volume":"1993 1","pages":"1-6"},"PeriodicalIF":0.0,"publicationDate":"2012-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82390294","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 : 2012-03-25DOI: 10.1109/AMC.2012.6197028
M. Mizuochi, K. Ohnishi
Precise bilateral teleoperation based on wide-band signals enables an operator to achieve complicated tasks. A short sampling period is required for acquisition and transmission of wide-band signals. The sampling period is limited, however, when controllers are connected through a network. In this paper, a coding and decoding scheme for wide-band bilateral teleoperation is proposed. The method uses a low pass filter and discrete Fourier transform for the coding and inverse discrete Fourier transform for the decoding. High frequency signals can be transmitted even under severe limitation on the packet transmission rate. The scheme was verified through experiment with bilateral teleoperation. The validity of the proposed method was confirmed in terms of the transmission of wide-band signals and the reproduction of wide-band haptic sensation.
{"title":"Coding and decoding scheme for wide-band bilateral teleoperation","authors":"M. Mizuochi, K. Ohnishi","doi":"10.1109/AMC.2012.6197028","DOIUrl":"https://doi.org/10.1109/AMC.2012.6197028","url":null,"abstract":"Precise bilateral teleoperation based on wide-band signals enables an operator to achieve complicated tasks. A short sampling period is required for acquisition and transmission of wide-band signals. The sampling period is limited, however, when controllers are connected through a network. In this paper, a coding and decoding scheme for wide-band bilateral teleoperation is proposed. The method uses a low pass filter and discrete Fourier transform for the coding and inverse discrete Fourier transform for the decoding. High frequency signals can be transmitted even under severe limitation on the packet transmission rate. The scheme was verified through experiment with bilateral teleoperation. The validity of the proposed method was confirmed in terms of the transmission of wide-band signals and the reproduction of wide-band haptic sensation.","PeriodicalId":6439,"journal":{"name":"2012 12th IEEE International Workshop on Advanced Motion Control (AMC)","volume":"51 1","pages":"1-6"},"PeriodicalIF":0.0,"publicationDate":"2012-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82777306","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 : 2012-03-25DOI: 10.1109/AMC.2012.6197027
E. D. Kunt, A. T. Naskali, A. Sabanoviç
In this paper, design and control issues for the development of miniaturized manipulators which are aimed to be used in high precision assembly and manipulation tasks are presented. The developed manipulators are size adapted devices, miniaturized versions of conventional robots based on well-known kinematic structures. 3 degrees of freedom (DOF) delta robot and a 2 DOF pantograph mechanism enhanced with a rotational axis at the tip and a Z axis actuating the whole mechanism are given as examples of study. These parallel mechanisms are designed and developed to be used in modular assembly systems for the realization of high precision assembly and manipulation tasks. In that sense, modularity is addressed as an important design consideration. The design procedures are given in details in order to provide solutions for miniaturization and experimental results are given to show the achieved performances.
{"title":"Miniaturized modular manipulator design for high precision assembly and manipulation tasks","authors":"E. D. Kunt, A. T. Naskali, A. Sabanoviç","doi":"10.1109/AMC.2012.6197027","DOIUrl":"https://doi.org/10.1109/AMC.2012.6197027","url":null,"abstract":"In this paper, design and control issues for the development of miniaturized manipulators which are aimed to be used in high precision assembly and manipulation tasks are presented. The developed manipulators are size adapted devices, miniaturized versions of conventional robots based on well-known kinematic structures. 3 degrees of freedom (DOF) delta robot and a 2 DOF pantograph mechanism enhanced with a rotational axis at the tip and a Z axis actuating the whole mechanism are given as examples of study. These parallel mechanisms are designed and developed to be used in modular assembly systems for the realization of high precision assembly and manipulation tasks. In that sense, modularity is addressed as an important design consideration. The design procedures are given in details in order to provide solutions for miniaturization and experimental results are given to show the achieved performances.","PeriodicalId":6439,"journal":{"name":"2012 12th IEEE International Workshop on Advanced Motion Control (AMC)","volume":"42 1","pages":"1-6"},"PeriodicalIF":0.0,"publicationDate":"2012-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88007657","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 : 2012-03-25DOI: 10.1109/AMC.2012.6197138
Elmir Babovic
This research is extension of previous research on method of Collaborative and Non-Collaborative Dynamic Path Prediction Algorithm for Mobile Agents Collision Detection with Dynamic Obstacles in 3D Space. In this research the extension of the algorithm for dynamic collaborative path prediction for mobile agents is proposed and two important issues Coefficient of agility and Minimal sampling frequency are analyzed. Those two terms are proposed in previous research for which background and introduction is explained in this paper. Solving Coefficient of agility and minimal sampling frequency issues allows system designers and developers to implement the method. This method allows full decentralization of collision detection which allows many advantages from minimizing of network traffic to simplifying of inclusion of additional agents in relevant space. Implementation of the algorithm will be low resource consuming allowing mobile agents to free resources for additional tasks.
{"title":"Coefficient of agility and sampling frequency issues in Mobile Agents Collision Detection with Dynamic Obstacles in 3D Space","authors":"Elmir Babovic","doi":"10.1109/AMC.2012.6197138","DOIUrl":"https://doi.org/10.1109/AMC.2012.6197138","url":null,"abstract":"This research is extension of previous research on method of Collaborative and Non-Collaborative Dynamic Path Prediction Algorithm for Mobile Agents Collision Detection with Dynamic Obstacles in 3D Space. In this research the extension of the algorithm for dynamic collaborative path prediction for mobile agents is proposed and two important issues Coefficient of agility and Minimal sampling frequency are analyzed. Those two terms are proposed in previous research for which background and introduction is explained in this paper. Solving Coefficient of agility and minimal sampling frequency issues allows system designers and developers to implement the method. This method allows full decentralization of collision detection which allows many advantages from minimizing of network traffic to simplifying of inclusion of additional agents in relevant space. Implementation of the algorithm will be low resource consuming allowing mobile agents to free resources for additional tasks.","PeriodicalId":6439,"journal":{"name":"2012 12th IEEE International Workshop on Advanced Motion Control (AMC)","volume":"69 1","pages":"1-6"},"PeriodicalIF":0.0,"publicationDate":"2012-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85855478","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 : 2012-03-25DOI: 10.1109/AMC.2012.6197042
M. Boegli, T. Laet, J. Schutter, J. Swevers
This paper presents a smoothed friction model that closely approximates the Generalized Maxwell-Slip (GMS) model, a multi-state friction model known to describe all essential friction characteristics in presliding and sliding motion. In contrast to the GMS model, which consists of a switching structure to accommodate for its hybrid nature, the Smoothed GMS (S-GMS) model consists of an analytic set of differential equations well suited for on-line state and parameter estimation, such as in Moving Horizon Estimation (MHE). Efficient on-line state and parameter estimation is essential for model-based friction compensation in order to track friction characteristics changes in time and space. Moreover, MHE is known to better handle model nonlinearities, disturbances and constraints than Extended Kalman Filter (EKF). This paper discusses the implementation of the EKF and MHE estimators for both the GMS and the S-GMS friction models. The benefit of the combination of MHE and S-GMS model is shown.
{"title":"A Smoothed GMS friction model for Moving Horizon friction state and parameter estimation","authors":"M. Boegli, T. Laet, J. Schutter, J. Swevers","doi":"10.1109/AMC.2012.6197042","DOIUrl":"https://doi.org/10.1109/AMC.2012.6197042","url":null,"abstract":"This paper presents a smoothed friction model that closely approximates the Generalized Maxwell-Slip (GMS) model, a multi-state friction model known to describe all essential friction characteristics in presliding and sliding motion. In contrast to the GMS model, which consists of a switching structure to accommodate for its hybrid nature, the Smoothed GMS (S-GMS) model consists of an analytic set of differential equations well suited for on-line state and parameter estimation, such as in Moving Horizon Estimation (MHE). Efficient on-line state and parameter estimation is essential for model-based friction compensation in order to track friction characteristics changes in time and space. Moreover, MHE is known to better handle model nonlinearities, disturbances and constraints than Extended Kalman Filter (EKF). This paper discusses the implementation of the EKF and MHE estimators for both the GMS and the S-GMS friction models. The benefit of the combination of MHE and S-GMS model is shown.","PeriodicalId":6439,"journal":{"name":"2012 12th IEEE International Workshop on Advanced Motion Control (AMC)","volume":"22 1","pages":"1-6"},"PeriodicalIF":0.0,"publicationDate":"2012-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89110142","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 : 2012-03-25DOI: 10.1109/AMC.2012.6197149
M. Huba
The paper represents first part of two contributions dealing with simplified modular design of constrained P and disturbance observer (DO) based PI control with different filtering properties illustrated by example of speed servo control. This first part is devoted to analysis of the core structure of the P controller tuned for different types of nonmodelled or filter dynamics. Openness of the approach means that for approximating additional dynamics of the P-controller structure different filters may be used without necessity to repeat in the nominal case analysis of the optimal and critical tuning. By simpler means, flexible approach enabling to fit requirements of particular loop and simultaneously offering reasonably better performance than the traditional controller design based on Luenberger disturbance observer for reconstruction of the velocity signal is proposed. Achieved performance is evaluated by newly introduced measures for deviations from monotonic and one-pulse shapes of transients typical for control of plants with dominant 1st order dynamics.
{"title":"Open flexible P-controller design","authors":"M. Huba","doi":"10.1109/AMC.2012.6197149","DOIUrl":"https://doi.org/10.1109/AMC.2012.6197149","url":null,"abstract":"The paper represents first part of two contributions dealing with simplified modular design of constrained P and disturbance observer (DO) based PI control with different filtering properties illustrated by example of speed servo control. This first part is devoted to analysis of the core structure of the P controller tuned for different types of nonmodelled or filter dynamics. Openness of the approach means that for approximating additional dynamics of the P-controller structure different filters may be used without necessity to repeat in the nominal case analysis of the optimal and critical tuning. By simpler means, flexible approach enabling to fit requirements of particular loop and simultaneously offering reasonably better performance than the traditional controller design based on Luenberger disturbance observer for reconstruction of the velocity signal is proposed. Achieved performance is evaluated by newly introduced measures for deviations from monotonic and one-pulse shapes of transients typical for control of plants with dominant 1st order dynamics.","PeriodicalId":6439,"journal":{"name":"2012 12th IEEE International Workshop on Advanced Motion Control (AMC)","volume":"131 1","pages":"1-6"},"PeriodicalIF":0.0,"publicationDate":"2012-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86188481","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 : 2012-03-25DOI: 10.1109/AMC.2012.6197040
Y. Seki, H. Fujimoto, K. Saiki
In general, Gantry-type precision stages have low resonance modes because the structure of the stages are large and complex. These resonance modes cause a pitch motion during the translation driving. In this paper, an optimal mechanical parameter design method is analyzed and explored via a two-inertia model. In these modes, primary resonance can be suppressed by Self Resonance Cancellation (SRC) and secondary resonance can be reduced by adjusting the mechanical parameters of the stage. Simulations and experiments with an experimental precision stage are performed to show the advantages of the proposed optimization design method.
{"title":"Optimal mechanical parameter design using Self Resonance Cancellation control for gantry-type high precision stage","authors":"Y. Seki, H. Fujimoto, K. Saiki","doi":"10.1109/AMC.2012.6197040","DOIUrl":"https://doi.org/10.1109/AMC.2012.6197040","url":null,"abstract":"In general, Gantry-type precision stages have low resonance modes because the structure of the stages are large and complex. These resonance modes cause a pitch motion during the translation driving. In this paper, an optimal mechanical parameter design method is analyzed and explored via a two-inertia model. In these modes, primary resonance can be suppressed by Self Resonance Cancellation (SRC) and secondary resonance can be reduced by adjusting the mechanical parameters of the stage. Simulations and experiments with an experimental precision stage are performed to show the advantages of the proposed optimization design method.","PeriodicalId":6439,"journal":{"name":"2012 12th IEEE International Workshop on Advanced Motion Control (AMC)","volume":"10 1","pages":"1-6"},"PeriodicalIF":0.0,"publicationDate":"2012-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86063017","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 : 2012-03-25DOI: 10.1109/AMC.2012.6197029
Y. Yokokura, K. Ohishi, S. Katsura
In this paper, Class-G power amplifiers for motion control are developed. General Class-B power amplifier cannot be used for driving high-power actuators because of power efficiency. On the other hand, due to PWM, typical Class-D power amplifier generates switching noise as well as desired current, though the power efficiency is very high. The switching noise cased by PWM inverter degrades the control performance of the motor. In short, typical Class-B and Class-D power amplifiers are not suitable for advanced motion control. By using Class-G amplifier, problem of both power efficiency and noise is able to be solved. Therefore, Class-G amplifier enhances the control performance of current controller for motion control. Driving test of Class-G power amplifiers is conducted. The current controller and force control system are implemented in FPGA. By the experiments, validity of the current control and force control with Class-G power amplifier is verified.
{"title":"Low-noise and fine-efficiency motor drive for motion control","authors":"Y. Yokokura, K. Ohishi, S. Katsura","doi":"10.1109/AMC.2012.6197029","DOIUrl":"https://doi.org/10.1109/AMC.2012.6197029","url":null,"abstract":"In this paper, Class-G power amplifiers for motion control are developed. General Class-B power amplifier cannot be used for driving high-power actuators because of power efficiency. On the other hand, due to PWM, typical Class-D power amplifier generates switching noise as well as desired current, though the power efficiency is very high. The switching noise cased by PWM inverter degrades the control performance of the motor. In short, typical Class-B and Class-D power amplifiers are not suitable for advanced motion control. By using Class-G amplifier, problem of both power efficiency and noise is able to be solved. Therefore, Class-G amplifier enhances the control performance of current controller for motion control. Driving test of Class-G power amplifiers is conducted. The current controller and force control system are implemented in FPGA. By the experiments, validity of the current control and force control with Class-G power amplifier is verified.","PeriodicalId":6439,"journal":{"name":"2012 12th IEEE International Workshop on Advanced Motion Control (AMC)","volume":"24 1","pages":"1-6"},"PeriodicalIF":0.0,"publicationDate":"2012-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73886588","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 : 2012-03-25DOI: 10.1109/AMC.2012.6197024
M. Nandayapa, C. Mitsantisuk, K. Ohishi
The bilateral control that is used in medical or industrial applications needs to offer rapid processing and precision. The Field Programmable Gate Array (FPGA) helps in this regard. The algorithms of velocity and acceleration estimation require a short processing time in implementation than do conventional estimation methods. Bilateral control is implemented in common and differential modes for force servoing and position regulator, respectively. Position, velocity and acceleration (PVA) feedback in the differential mode enhance position tracking in the bilateral control. The bilateral robot system is implemented using ball screw mechanisms.
{"title":"Improving bilateral control feedback by using novel velocity and acceleration estimation methods in FPGA","authors":"M. Nandayapa, C. Mitsantisuk, K. Ohishi","doi":"10.1109/AMC.2012.6197024","DOIUrl":"https://doi.org/10.1109/AMC.2012.6197024","url":null,"abstract":"The bilateral control that is used in medical or industrial applications needs to offer rapid processing and precision. The Field Programmable Gate Array (FPGA) helps in this regard. The algorithms of velocity and acceleration estimation require a short processing time in implementation than do conventional estimation methods. Bilateral control is implemented in common and differential modes for force servoing and position regulator, respectively. Position, velocity and acceleration (PVA) feedback in the differential mode enhance position tracking in the bilateral control. The bilateral robot system is implemented using ball screw mechanisms.","PeriodicalId":6439,"journal":{"name":"2012 12th IEEE International Workshop on Advanced Motion Control (AMC)","volume":"64 1","pages":"1-6"},"PeriodicalIF":0.0,"publicationDate":"2012-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80590806","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 : 2012-03-25DOI: 10.1109/AMC.2012.6197131
M. Spaner, A. Rojko, K. Jezernik
Hybrid electric vehicles are one of the most effective solutions to improve our environment, one of few such products that are available at the mass-market and also accepted by the customers. With the improved energy storage systems and control algorithms, hybrid vehicles can further gain on the applicability and consequently on the popularity. In this paper, a design and control of the elements of the hybrid vehicle propulsion system, with an emphasis on supercapacitor as the peak energy storage unit, is presented. The propulsion system is dimensioned for light delivery vehicle. In order to simplify design and testing, a laboratory test rig was built rather than using the complete vehicle. Trough simulations and experiments a significant improvement of the properties of energy storage system is confirmed after adding the supercapacitor to the battery. The experiments also confirm the advantages of energy flow management based on the stabilization of the common DC bus voltage.
{"title":"Design and realization of hybrid drive with supercapacitor and power flow control","authors":"M. Spaner, A. Rojko, K. Jezernik","doi":"10.1109/AMC.2012.6197131","DOIUrl":"https://doi.org/10.1109/AMC.2012.6197131","url":null,"abstract":"Hybrid electric vehicles are one of the most effective solutions to improve our environment, one of few such products that are available at the mass-market and also accepted by the customers. With the improved energy storage systems and control algorithms, hybrid vehicles can further gain on the applicability and consequently on the popularity. In this paper, a design and control of the elements of the hybrid vehicle propulsion system, with an emphasis on supercapacitor as the peak energy storage unit, is presented. The propulsion system is dimensioned for light delivery vehicle. In order to simplify design and testing, a laboratory test rig was built rather than using the complete vehicle. Trough simulations and experiments a significant improvement of the properties of energy storage system is confirmed after adding the supercapacitor to the battery. The experiments also confirm the advantages of energy flow management based on the stabilization of the common DC bus voltage.","PeriodicalId":6439,"journal":{"name":"2012 12th IEEE International Workshop on Advanced Motion Control (AMC)","volume":"59 1","pages":"1-6"},"PeriodicalIF":0.0,"publicationDate":"2012-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80534963","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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