Pub Date : 2011-10-13DOI: 10.1109/CCA.2011.6044447
R. Su, J. H. Schuppen, J. Rooda
In many practical applications we need to compute a nonblocking supervisor that not only complies with pre-specified safety requirements but also achieves a certain time optimal performance such as maximum throughput. In this paper we first present a minimum-makespan supervisor synthesis problem. Then we show that the problem can be solved by a terminable algorithm, where the execution time of each string is computable by the theory of heaps-of-pieces.
{"title":"Using heaps-of-pieces in synthesis of time optimal supervisors","authors":"R. Su, J. H. Schuppen, J. Rooda","doi":"10.1109/CCA.2011.6044447","DOIUrl":"https://doi.org/10.1109/CCA.2011.6044447","url":null,"abstract":"In many practical applications we need to compute a nonblocking supervisor that not only complies with pre-specified safety requirements but also achieves a certain time optimal performance such as maximum throughput. In this paper we first present a minimum-makespan supervisor synthesis problem. Then we show that the problem can be solved by a terminable algorithm, where the execution time of each string is computable by the theory of heaps-of-pieces.","PeriodicalId":208713,"journal":{"name":"2011 IEEE International Conference on Control Applications (CCA)","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130189896","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 : 2011-10-13DOI: 10.1109/CCA.2011.6044431
M. Boyer, E. Schuster
The control of plasma density and temperature are among the most fundamental problems in fusion reactors and will be critical to the success of burning plasma experiments like ITER. While stable burn conditions exist, it is possible that economic and technological constraints will require future commercial reactors to operate with low temperature, high density plasma, a burn condition that may be unstable. The instability is due to the fact that for low temperatures, the fusion heating increases as the plasma temperature rises. An active control system will be essential for stabilizing such operating points. In this work a spatially averaged (zero-dimensional) nonlinear transport model for the energy and the densities of deuterium and tritium fuel ions, as well as the alpha-particles, is used to synthesize a nonlinear feedback controller for stabilizing the burn condition of a fusion reactor. Whereas previous efforts assume an optimal 50:50 mix of deuterium and tritium fuel, this controller makes use of ITER's planned isotopic fueling capability and controls the densities of these ions separately. Also, unlike previous work which used impurity injection to mitigate thermal excursions, this design exploits the ability to modulate the DT fuel mix to control the plasma heating. By moving the isotopic mix in the plasma away from the optimal 50:50 mix, the reaction rate is slowed and the alpha-particle heating is reduced to desired levels. A zero-dimensional simulation study is presented to show the ability of the controller to bring the system back to the desired equilibrium from a given set of perturbations.
{"title":"Zero-dimensional nonlinear burn control using isotopic fuel tailoring for thermal excursions","authors":"M. Boyer, E. Schuster","doi":"10.1109/CCA.2011.6044431","DOIUrl":"https://doi.org/10.1109/CCA.2011.6044431","url":null,"abstract":"The control of plasma density and temperature are among the most fundamental problems in fusion reactors and will be critical to the success of burning plasma experiments like ITER. While stable burn conditions exist, it is possible that economic and technological constraints will require future commercial reactors to operate with low temperature, high density plasma, a burn condition that may be unstable. The instability is due to the fact that for low temperatures, the fusion heating increases as the plasma temperature rises. An active control system will be essential for stabilizing such operating points. In this work a spatially averaged (zero-dimensional) nonlinear transport model for the energy and the densities of deuterium and tritium fuel ions, as well as the alpha-particles, is used to synthesize a nonlinear feedback controller for stabilizing the burn condition of a fusion reactor. Whereas previous efforts assume an optimal 50:50 mix of deuterium and tritium fuel, this controller makes use of ITER's planned isotopic fueling capability and controls the densities of these ions separately. Also, unlike previous work which used impurity injection to mitigate thermal excursions, this design exploits the ability to modulate the DT fuel mix to control the plasma heating. By moving the isotopic mix in the plasma away from the optimal 50:50 mix, the reaction rate is slowed and the alpha-particle heating is reduced to desired levels. A zero-dimensional simulation study is presented to show the ability of the controller to bring the system back to the desired equilibrium from a given set of perturbations.","PeriodicalId":208713,"journal":{"name":"2011 IEEE International Conference on Control Applications (CCA)","volume":"59 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114891879","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 : 2011-10-13DOI: 10.1109/CCA.2011.6044477
Kazuya Sato, M. Yanagi, K. Tsuruta
This paper considers the design of an adaptive trajectory tracking control strategy of nonholonomic wheeled mobile robots which is based on H∞ control method. Kinematics control laws of mobile robots is well known, therefore, developing the dynamics control is focused. It is shown that the resulting dynamics control strategy can compensate not only the physical parameters of mobile robot, but also the input torque uncertainty and the input torque disturbance based on adaptive H∞ method. Numerical simulations are given to show the effectiveness of the proposed method.
{"title":"Adaptive H∞ trajectory control of nonholonomic mobile robot with compensation of input uncertainty","authors":"Kazuya Sato, M. Yanagi, K. Tsuruta","doi":"10.1109/CCA.2011.6044477","DOIUrl":"https://doi.org/10.1109/CCA.2011.6044477","url":null,"abstract":"This paper considers the design of an adaptive trajectory tracking control strategy of nonholonomic wheeled mobile robots which is based on H∞ control method. Kinematics control laws of mobile robots is well known, therefore, developing the dynamics control is focused. It is shown that the resulting dynamics control strategy can compensate not only the physical parameters of mobile robot, but also the input torque uncertainty and the input torque disturbance based on adaptive H∞ method. Numerical simulations are given to show the effectiveness of the proposed method.","PeriodicalId":208713,"journal":{"name":"2011 IEEE International Conference on Control Applications (CCA)","volume":"10 1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116444300","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 : 2011-10-13DOI: 10.1109/CCA.2011.6044498
Ganga P. Jayaraman, Stephen V. Lunzman
This paper presents an observer design that may be used to improve the response and stability characteristics of a solenoid operated pressure-reducing valve. Most pressure-reducing valves have very little inherent damping, and can potentially exhibit unstable behavior due to fluid velocity effects during the opening of the poppet. One solution is to improve the dynamic characteristics of the valve by using a closed-loop control strategy. Here, the solenoid current, poppet position, the poppet velocity and the control pressure are feedback signals, used to increase the stability margin and the response time. The cost of the sensors and problems associated with taking derivatives make direct measurement infeasible. We propose to obtain estimates of the poppet position and poppet velocity from only measurements of the valve control pressure and the solenoid current. This is done using a state observer that estimates the poppet position and the poppet velocity without calculating derivatives. These estimates may then be used in a feedback controller that is designed to meet the valve transient response specifications.
{"title":"An observer design for a poppet type pressure reducing valve","authors":"Ganga P. Jayaraman, Stephen V. Lunzman","doi":"10.1109/CCA.2011.6044498","DOIUrl":"https://doi.org/10.1109/CCA.2011.6044498","url":null,"abstract":"This paper presents an observer design that may be used to improve the response and stability characteristics of a solenoid operated pressure-reducing valve. Most pressure-reducing valves have very little inherent damping, and can potentially exhibit unstable behavior due to fluid velocity effects during the opening of the poppet. One solution is to improve the dynamic characteristics of the valve by using a closed-loop control strategy. Here, the solenoid current, poppet position, the poppet velocity and the control pressure are feedback signals, used to increase the stability margin and the response time. The cost of the sensors and problems associated with taking derivatives make direct measurement infeasible. We propose to obtain estimates of the poppet position and poppet velocity from only measurements of the valve control pressure and the solenoid current. This is done using a state observer that estimates the poppet position and the poppet velocity without calculating derivatives. These estimates may then be used in a feedback controller that is designed to meet the valve transient response specifications.","PeriodicalId":208713,"journal":{"name":"2011 IEEE International Conference on Control Applications (CCA)","volume":"52 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114785431","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 : 2011-10-13DOI: 10.1109/CCA.2011.6044415
Sungil Kwon, L. Castellano, M. Prokop, P. Torrez, A. Scheinker
The current LANSCE LLRF system is an analog PI Feedback control system which achieves amplitude and phase error of 1% and 1 degree respectively. The feedback system receives cavity amplitude and phase, crosstalk between the amplitude and phase paths is significant. We propose an In-phase (I) and Quadrature (Q) based feedback control system which easily decouples the crosstalk of the I and Q channels. A PI feedback controller is implemented with an Altera Stratix III FPGA. The control system is modeled with DSP Builder which automatically generates HDL. Altera SOPC Builder is used for the hardware integration of the DSP Builder model, memories, peripherals, and 32 bit NIOS II embedded processor. The NIOS II processor communicates with the host computer via Ethernet, uploads data, computes parameters, and downloads parameters. The network support of the design makes it possible to set and tune the control system parameters on-line and to conduct the calibration of the whole RF system easily. The proposed control system is successfully tested with a LANSCE sided-coupled linear accelerator at 720kw.
{"title":"FPGA implementation of a prototype PI Feedback control system for the LANSCE accelerator","authors":"Sungil Kwon, L. Castellano, M. Prokop, P. Torrez, A. Scheinker","doi":"10.1109/CCA.2011.6044415","DOIUrl":"https://doi.org/10.1109/CCA.2011.6044415","url":null,"abstract":"The current LANSCE LLRF system is an analog PI Feedback control system which achieves amplitude and phase error of 1% and 1 degree respectively. The feedback system receives cavity amplitude and phase, crosstalk between the amplitude and phase paths is significant. We propose an In-phase (I) and Quadrature (Q) based feedback control system which easily decouples the crosstalk of the I and Q channels. A PI feedback controller is implemented with an Altera Stratix III FPGA. The control system is modeled with DSP Builder which automatically generates HDL. Altera SOPC Builder is used for the hardware integration of the DSP Builder model, memories, peripherals, and 32 bit NIOS II embedded processor. The NIOS II processor communicates with the host computer via Ethernet, uploads data, computes parameters, and downloads parameters. The network support of the design makes it possible to set and tune the control system parameters on-line and to conduct the calibration of the whole RF system easily. The proposed control system is successfully tested with a LANSCE sided-coupled linear accelerator at 720kw.","PeriodicalId":208713,"journal":{"name":"2011 IEEE International Conference on Control Applications (CCA)","volume":"211 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132873685","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 : 2011-10-13DOI: 10.1109/CCA.2011.6044512
Kyarash Shahriari, F. Ding
In this paper, the correlation between process variability attenuation and efficiency enhancement in industrial processes is studied. The starting hypothesis of this work states that process variability attenuation brings about efficiency enhancements in both energy and productivity aspects. To test the hypothesis, a multi-variable statistical approach requiring no process model is proposed. The approach is applied to two case studies in pulp and paper industry. The results approve the starting hypothesis while they can further be used to justify any capital investment in advanced control systems to attenuate process variability.
{"title":"Process variability and inherent efficiency enhancement in industrial processes: Two case studies in pulp and paper industry","authors":"Kyarash Shahriari, F. Ding","doi":"10.1109/CCA.2011.6044512","DOIUrl":"https://doi.org/10.1109/CCA.2011.6044512","url":null,"abstract":"In this paper, the correlation between process variability attenuation and efficiency enhancement in industrial processes is studied. The starting hypothesis of this work states that process variability attenuation brings about efficiency enhancements in both energy and productivity aspects. To test the hypothesis, a multi-variable statistical approach requiring no process model is proposed. The approach is applied to two case studies in pulp and paper industry. The results approve the starting hypothesis while they can further be used to justify any capital investment in advanced control systems to attenuate process variability.","PeriodicalId":208713,"journal":{"name":"2011 IEEE International Conference on Control Applications (CCA)","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126966732","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 : 2011-10-13DOI: 10.1109/CCA.2011.6044454
G. Downton, M. Ignova
A directionally controlled drilling mechanism has a lateral borehole propagation equation of state composed of spatially delayed feedback terms determined by the distribution of contact points between the borehole and drilling mechanism. A lateral borehole propagation equation is developed for a generic class of steering system. After simplification the resulting linear delay differential equation is partially validated against a Finite Element Model (FEM) of borehole propagation. The linear delay differential equations are then incorporated into various closed loop steering configurations to further demonstrate the efficacy of the approach.
{"title":"Stability and response of closed loop directional drilling system using linear delay differential equations","authors":"G. Downton, M. Ignova","doi":"10.1109/CCA.2011.6044454","DOIUrl":"https://doi.org/10.1109/CCA.2011.6044454","url":null,"abstract":"A directionally controlled drilling mechanism has a lateral borehole propagation equation of state composed of spatially delayed feedback terms determined by the distribution of contact points between the borehole and drilling mechanism. A lateral borehole propagation equation is developed for a generic class of steering system. After simplification the resulting linear delay differential equation is partially validated against a Finite Element Model (FEM) of borehole propagation. The linear delay differential equations are then incorporated into various closed loop steering configurations to further demonstrate the efficacy of the approach.","PeriodicalId":208713,"journal":{"name":"2011 IEEE International Conference on Control Applications (CCA)","volume":"455 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125792198","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 : 2011-10-13DOI: 10.1109/CCA.2011.6044363
Allistair Moses, M. Rutherford, K. Valavanis
It is claimed that Unmanned Aerial Vehicles (UAVs) used for civilian/public domain applications will be dominant in the near future. Compared to UAVs used by the military, civilian UAVs are often operated by pilots without formal training, and hence they require increased levels of autonomy and intelligence, especially with regard to reducing threats to public safety. UAV integration into the National Air Space will require that the UAVs support multiple, complementary sense-and-avoid mechanisms, including detection and identification of other UAV-sized targets. Currently, the majority of available sensors are based on infrared detectors, focal plane arrays, optical and ultrasonic rangefinders. These sensors are generally not able to detect or identify other UAV-sized targets and, when detection is possible, considerable computational power may be required for successful identification. By contrast, this paper describes the design of a light weight, X-Band (10.5GHz) radar system for use on a small-scale (< 25 kg) rotorcraft. The prototype radar implementation is small enough to be carried by any miniature UAV, and it is capable of differentiating other miniature rotorcraft by their doppler signature. In addition to the overall hardware and software design of the prototype system, a performance analysis of various signature matching algorithms is presented demonstrating the capabilities of the system in a laboratory setting.
{"title":"Radar-based detection and identification for miniature air vehicles","authors":"Allistair Moses, M. Rutherford, K. Valavanis","doi":"10.1109/CCA.2011.6044363","DOIUrl":"https://doi.org/10.1109/CCA.2011.6044363","url":null,"abstract":"It is claimed that Unmanned Aerial Vehicles (UAVs) used for civilian/public domain applications will be dominant in the near future. Compared to UAVs used by the military, civilian UAVs are often operated by pilots without formal training, and hence they require increased levels of autonomy and intelligence, especially with regard to reducing threats to public safety. UAV integration into the National Air Space will require that the UAVs support multiple, complementary sense-and-avoid mechanisms, including detection and identification of other UAV-sized targets. Currently, the majority of available sensors are based on infrared detectors, focal plane arrays, optical and ultrasonic rangefinders. These sensors are generally not able to detect or identify other UAV-sized targets and, when detection is possible, considerable computational power may be required for successful identification. By contrast, this paper describes the design of a light weight, X-Band (10.5GHz) radar system for use on a small-scale (< 25 kg) rotorcraft. The prototype radar implementation is small enough to be carried by any miniature UAV, and it is capable of differentiating other miniature rotorcraft by their doppler signature. In addition to the overall hardware and software design of the prototype system, a performance analysis of various signature matching algorithms is presented demonstrating the capabilities of the system in a laboratory setting.","PeriodicalId":208713,"journal":{"name":"2011 IEEE International Conference on Control Applications (CCA)","volume":"91 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124660208","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 : 2011-10-13DOI: 10.1109/CCA.2011.6044412
Kam W. Lui, J. Hunt
This paper describes the development of Slider automated directional drilling technology and addresses the benefits, automation strategy, the challenges encountered, and the solutions developed over the last 8 years. The paper will examine the following topics: • Challenges a directional driller faces controlling a drilling rig while directionally drilling a well • How automation and control can simplify the execution of repetitive actions and enable the directional drillers to perform their job at a higher level • Benefits of automated drilling • Using automation to protect rotating equipment from damage that may be caused by manual operation, thereby decreasing equipment downtime • Developing automation system architecture that will enable the adaptation of various types of pipe rotating equipment • Field examples and a description of the widely accepted Slider technology in today's directional drilling world
{"title":"Rotating equipment automation for directional drilling: Brain over brawn","authors":"Kam W. Lui, J. Hunt","doi":"10.1109/CCA.2011.6044412","DOIUrl":"https://doi.org/10.1109/CCA.2011.6044412","url":null,"abstract":"This paper describes the development of Slider automated directional drilling technology and addresses the benefits, automation strategy, the challenges encountered, and the solutions developed over the last 8 years. The paper will examine the following topics: • Challenges a directional driller faces controlling a drilling rig while directionally drilling a well • How automation and control can simplify the execution of repetitive actions and enable the directional drillers to perform their job at a higher level • Benefits of automated drilling • Using automation to protect rotating equipment from damage that may be caused by manual operation, thereby decreasing equipment downtime • Developing automation system architecture that will enable the adaptation of various types of pipe rotating equipment • Field examples and a description of the widely accepted Slider technology in today's directional drilling world","PeriodicalId":208713,"journal":{"name":"2011 IEEE International Conference on Control Applications (CCA)","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126025997","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 : 2011-10-13DOI: 10.1109/CCA.2011.6044472
M. Ringdorfer, M. Horn
A new vehicle stability control approach for electric vehicles is introduced. The proposed wheel slip controller extends the functionality of state-of-the-art electric vehicle operation strategies and closes the gap to driver assistance systems and conventional vehicle dynamics control systems. Maximum energy efficiency and driving safety can be guaranteed by coordinated control of the electrical propulsion system and the mechanical braking system. During safe vehicle operation, the controller monitors the vehicle operation unit and in case of a blocking or spinning wheel, it assures anti blocking and anti slip functionalities by coordinating mechanical brake interventions and single wheel traction motor control. The proposed controller structure is outlined and first simulation results are presented.
{"title":"Development of a wheel slip actuator controller for electric vehicles using energy recuperation and hydraulic brake control","authors":"M. Ringdorfer, M. Horn","doi":"10.1109/CCA.2011.6044472","DOIUrl":"https://doi.org/10.1109/CCA.2011.6044472","url":null,"abstract":"A new vehicle stability control approach for electric vehicles is introduced. The proposed wheel slip controller extends the functionality of state-of-the-art electric vehicle operation strategies and closes the gap to driver assistance systems and conventional vehicle dynamics control systems. Maximum energy efficiency and driving safety can be guaranteed by coordinated control of the electrical propulsion system and the mechanical braking system. During safe vehicle operation, the controller monitors the vehicle operation unit and in case of a blocking or spinning wheel, it assures anti blocking and anti slip functionalities by coordinating mechanical brake interventions and single wheel traction motor control. The proposed controller structure is outlined and first simulation results are presented.","PeriodicalId":208713,"journal":{"name":"2011 IEEE International Conference on Control Applications (CCA)","volume":"58 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130043319","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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