Lu Wang, Sardar Ansari, Yingjie Cai, Kevin Ward, K. Najarian, K. Oldham
The state of the peripheral arteries is known to be a key physiological indicator of the body’s response to both acute and chronic medical conditions. In this paper, changes in peripheral artery behavior are tracked by combining a photo plethysmograph (PPG) sensor and a piezoelectric (PVDF) sensor with an outside pressure-varying cuff. In a swine subject, a simple mechanical model for the local artery and tissue captures broad features present in the PPG and PVDF signals, with respect to varying cuff pressure. These behaviors may provide insight into robustness of cardiovascular property identification by non-invasive wearable sensing.
{"title":"Modeling Peripheral Artery Behavior Beneath a Non-Invasive Wearable Sensor Subject to Varying Outside Pressure","authors":"Lu Wang, Sardar Ansari, Yingjie Cai, Kevin Ward, K. Najarian, K. Oldham","doi":"10.1115/dscc2019-9221","DOIUrl":"https://doi.org/10.1115/dscc2019-9221","url":null,"abstract":"\u0000 The state of the peripheral arteries is known to be a key physiological indicator of the body’s response to both acute and chronic medical conditions. In this paper, changes in peripheral artery behavior are tracked by combining a photo plethysmograph (PPG) sensor and a piezoelectric (PVDF) sensor with an outside pressure-varying cuff. In a swine subject, a simple mechanical model for the local artery and tissue captures broad features present in the PPG and PVDF signals, with respect to varying cuff pressure. These behaviors may provide insight into robustness of cardiovascular property identification by non-invasive wearable sensing.","PeriodicalId":41412,"journal":{"name":"Mechatronic Systems and Control","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2019-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72577675","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}
This paper identifies how the topology of a microgrid, particularly with respect to localized power injections, can affect the overall stability of the system. Microgrids are smaller-scale power networks that can disconnect from, and operate independently to, the main grid if necessary; accordingly, distributed and local generation is much more common in these systems. Of these local power sources, a significant proportion interface with the microgrid via inverters, and therefore lack physical inertia. This absence of physical inertia exacerbates the control challenge in a microgrid. These issues motivate the question of how to best control distributed generators to realize grid-wide improvements to power quality. We outline how the placement of controlled distributed generators can result in varying degrees of improved transient behavior, following disturbances to a microgrid. In this resulting simulations and analysis, we find that when the power sources in a microgrid are of varying capacity or rating, then the network topology can have a significant effect on transient performance deterioration. Notably, we find that if even a single a lower rated power source is ‘near’ or adjacent to a grid disturbance, then the microgrid may experience severe harmonic disturbances. In addition, we show that if such sources are controlled with a decentralized optimal controller, rather than a typical droop mechanism, then the overall microgrid performance is significantly improved.
{"title":"Understanding the Role of Microgrid Topology for Decentralized Model-Based Control","authors":"Matthew K. Chu Cheong, Dongmei Chen, P. Du","doi":"10.1115/dscc2019-9103","DOIUrl":"https://doi.org/10.1115/dscc2019-9103","url":null,"abstract":"\u0000 This paper identifies how the topology of a microgrid, particularly with respect to localized power injections, can affect the overall stability of the system. Microgrids are smaller-scale power networks that can disconnect from, and operate independently to, the main grid if necessary; accordingly, distributed and local generation is much more common in these systems. Of these local power sources, a significant proportion interface with the microgrid via inverters, and therefore lack physical inertia. This absence of physical inertia exacerbates the control challenge in a microgrid. These issues motivate the question of how to best control distributed generators to realize grid-wide improvements to power quality. We outline how the placement of controlled distributed generators can result in varying degrees of improved transient behavior, following disturbances to a microgrid. In this resulting simulations and analysis, we find that when the power sources in a microgrid are of varying capacity or rating, then the network topology can have a significant effect on transient performance deterioration. Notably, we find that if even a single a lower rated power source is ‘near’ or adjacent to a grid disturbance, then the microgrid may experience severe harmonic disturbances. In addition, we show that if such sources are controlled with a decentralized optimal controller, rather than a typical droop mechanism, then the overall microgrid performance is significantly improved.","PeriodicalId":41412,"journal":{"name":"Mechatronic Systems and Control","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2019-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77027832","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}
In this paper, the authors derive backstepping control laws for tracking a time-based reference trajectory for a 3D model of an autonomous vehicle with two degrees of underactuation. Tracking all six degrees of freedom is made possible by a transformation that reduces the order of the error dynamics. Stability of the resulting error dynamics is proven and demonstrated in simulations.
{"title":"Trajectory Tracking of 3D Autonomous Vehicles Using Backstepping Control","authors":"K. L. Fetzer, S. Nersesov, H. Ashrafiuon","doi":"10.1115/dscc2019-8954","DOIUrl":"https://doi.org/10.1115/dscc2019-8954","url":null,"abstract":"\u0000 In this paper, the authors derive backstepping control laws for tracking a time-based reference trajectory for a 3D model of an autonomous vehicle with two degrees of underactuation. Tracking all six degrees of freedom is made possible by a transformation that reduces the order of the error dynamics. Stability of the resulting error dynamics is proven and demonstrated in simulations.","PeriodicalId":41412,"journal":{"name":"Mechatronic Systems and Control","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2019-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79800068","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}
Predicting the diffusion of real-world contagion processes requires a simplified description of human-to-human interactions. Temporal networks offer a powerful means to develop such a mathematically-transparent description. Through temporal networks, one may analytically study the co-evolution of the contagion process and the network topology, as well as incorporate realistic feedback-loop mechanisms related to individual behavioral changes to the contagion. Despite considerable progress, the state-of-the-art does not allow for studying general time-varying networks, where links between individuals dynamically switch to reflect the complexity of social behavior. Here, we tackle this problem by considering a temporal network, in which reducible, associated with node-specific properties, and irreducible links, describing dyadic social ties, simultaneously vary over time. We develop a general mean field theory for the Susceptible-Infected-Susceptible model and conduct an extensive numerical campaign to elucidate the role of network parameters on the average degree of the temporal network and the epidemic threshold. Specifically, we describe how the interplay between reducible and irreducible links influences the disease dynamics, offering insights towards the analysis of complex dynamical networks across science and engineering.
{"title":"Contagion Processes Over Temporal Networks With Time-Varying Backbones","authors":"Matthieu Nadini, A. Rizzo, M. Porfiri","doi":"10.1115/dscc2019-9054","DOIUrl":"https://doi.org/10.1115/dscc2019-9054","url":null,"abstract":"\u0000 Predicting the diffusion of real-world contagion processes requires a simplified description of human-to-human interactions. Temporal networks offer a powerful means to develop such a mathematically-transparent description. Through temporal networks, one may analytically study the co-evolution of the contagion process and the network topology, as well as incorporate realistic feedback-loop mechanisms related to individual behavioral changes to the contagion. Despite considerable progress, the state-of-the-art does not allow for studying general time-varying networks, where links between individuals dynamically switch to reflect the complexity of social behavior. Here, we tackle this problem by considering a temporal network, in which reducible, associated with node-specific properties, and irreducible links, describing dyadic social ties, simultaneously vary over time. We develop a general mean field theory for the Susceptible-Infected-Susceptible model and conduct an extensive numerical campaign to elucidate the role of network parameters on the average degree of the temporal network and the epidemic threshold. Specifically, we describe how the interplay between reducible and irreducible links influences the disease dynamics, offering insights towards the analysis of complex dynamical networks across science and engineering.","PeriodicalId":41412,"journal":{"name":"Mechatronic Systems and Control","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2019-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80416769","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}
Various studies in hand-arm vibrations have shown that isolators in the form of anti-vibration (AV) gloves are effective to reduce unwanted vibrations, transmitted to the human hand, from machines and hand tools. However, most of these studies are based on experimental or numerical analysis and hence, the level of effectiveness and optimum values of the glove’s properties remain unclear. In this work, we analytically study the dynamics of hand-arm vibrations with and without a glove using the harmonic balance method. The considered analytical models for the hand-arm vibration comprise of lumped multi-degree of freedom system. The hand-tool interactions are modeled as linear spring and damper system for simplicity and accordingly, we obtain the equations governing the dynamics of the human-hand system. We perform parametric analysis using this bio-mechanical model of the hand-arm vibrations with and without a glove. The parametric analysis on the relative transmissibility (i.e., the ratio of transmissibilities with glove to without glove) shows the dependence of the transmissibility on the glove parameters. We observe that the effect of glove parameters on the relative transmissibility is not monotonous for the studied frequency range. This observation further motivates us to perform optimization of the glove parameters to minimize the overall transmissibility.
{"title":"On the Modeling and Optimization of Anti-Vibration Gloves for Hand-Arm Vibration Control","authors":"S. K. Gupta, Oreoluwa Alabi, Paul Kakou, O. Barry","doi":"10.1115/dscc2019-9094","DOIUrl":"https://doi.org/10.1115/dscc2019-9094","url":null,"abstract":"\u0000 Various studies in hand-arm vibrations have shown that isolators in the form of anti-vibration (AV) gloves are effective to reduce unwanted vibrations, transmitted to the human hand, from machines and hand tools. However, most of these studies are based on experimental or numerical analysis and hence, the level of effectiveness and optimum values of the glove’s properties remain unclear. In this work, we analytically study the dynamics of hand-arm vibrations with and without a glove using the harmonic balance method. The considered analytical models for the hand-arm vibration comprise of lumped multi-degree of freedom system. The hand-tool interactions are modeled as linear spring and damper system for simplicity and accordingly, we obtain the equations governing the dynamics of the human-hand system. We perform parametric analysis using this bio-mechanical model of the hand-arm vibrations with and without a glove. The parametric analysis on the relative transmissibility (i.e., the ratio of transmissibilities with glove to without glove) shows the dependence of the transmissibility on the glove parameters. We observe that the effect of glove parameters on the relative transmissibility is not monotonous for the studied frequency range. This observation further motivates us to perform optimization of the glove parameters to minimize the overall transmissibility.","PeriodicalId":41412,"journal":{"name":"Mechatronic Systems and Control","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2019-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90669957","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}
Jingqiang Zha, Junmin Wang, Min Li, Xin Zhang, Xiao Yu
Non-smooth structured robust controller design has drawn a lot of attention recently due to its ability to deal with uncertainty and its convenience for implementation. In this paper, the method is extended to design the structured robust linear parameter-varying (LPV) estimator by pulling out scheduling variables from estimator using linear fractional transformation (LFT). The structured robust LPV estimator is then applied to vehicle sideslip angle estimation. Both the measured vehicle speed and estimated tire cornering stiffness are treated as scheduling variables to further reduce sideslip angle estimation error. The effects of estimator order and number of repetitiveness of scheduling variables are studied using a MATLAB/Simulink bicycle model. The developed approach is later verified in Hardware-in-the-Loop (HIL) simulation environment using dSPACE SCALEXIO and MicroAutoBox. A comprehensive high-fidelity dSPACE automotive simulation models (ASM) vehicle model is used for the real-time HIL simulation. Double-lane change and sine steer maneuvers have been implemented to verify the effectiveness of the structured robust LPV sideslip angle estimation method.
{"title":"Structured Robust Linear Parameter-Varying Vehicle Sideslip Angle Estimation","authors":"Jingqiang Zha, Junmin Wang, Min Li, Xin Zhang, Xiao Yu","doi":"10.1115/dscc2019-9021","DOIUrl":"https://doi.org/10.1115/dscc2019-9021","url":null,"abstract":"\u0000 Non-smooth structured robust controller design has drawn a lot of attention recently due to its ability to deal with uncertainty and its convenience for implementation. In this paper, the method is extended to design the structured robust linear parameter-varying (LPV) estimator by pulling out scheduling variables from estimator using linear fractional transformation (LFT). The structured robust LPV estimator is then applied to vehicle sideslip angle estimation. Both the measured vehicle speed and estimated tire cornering stiffness are treated as scheduling variables to further reduce sideslip angle estimation error. The effects of estimator order and number of repetitiveness of scheduling variables are studied using a MATLAB/Simulink bicycle model. The developed approach is later verified in Hardware-in-the-Loop (HIL) simulation environment using dSPACE SCALEXIO and MicroAutoBox. A comprehensive high-fidelity dSPACE automotive simulation models (ASM) vehicle model is used for the real-time HIL simulation. Double-lane change and sine steer maneuvers have been implemented to verify the effectiveness of the structured robust LPV sideslip angle estimation method.","PeriodicalId":41412,"journal":{"name":"Mechatronic Systems and Control","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2019-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90269888","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}
This paper focuses on the problem of multiple slow moving and less maneuverable evaders against an agile pursuer, addressing the optimal strategy for multiple evaders. This is the so-called wolf-sheep game. Two scenarios are examined: 1) both pursuer and evaders have perfect knowledge about opponents, and 2) the pursuer has limited detection capability. Since the wolf-sheep game involves the Boolean value state, the game is hard to solve using traditional methods. This paper adopts a hierarchical approach. The two player game is solved first. Then the solution of the multiplayer game is based on the two-player game and the pursuer chasing order. The optimal strategy is calculated based on Nash equilibrium. The game with limited detection capability is solved by maximizing the Close Point of Approach (CPA). The optimal solution will be found theoretically and numerically.
{"title":"Optimal Strategy for Multiple Evaders Against an Agile Pursuer","authors":"Chunsheng Liu, M. Trevorrow","doi":"10.1115/dscc2019-8924","DOIUrl":"https://doi.org/10.1115/dscc2019-8924","url":null,"abstract":"\u0000 This paper focuses on the problem of multiple slow moving and less maneuverable evaders against an agile pursuer, addressing the optimal strategy for multiple evaders. This is the so-called wolf-sheep game. Two scenarios are examined: 1) both pursuer and evaders have perfect knowledge about opponents, and 2) the pursuer has limited detection capability. Since the wolf-sheep game involves the Boolean value state, the game is hard to solve using traditional methods. This paper adopts a hierarchical approach. The two player game is solved first. Then the solution of the multiplayer game is based on the two-player game and the pursuer chasing order. The optimal strategy is calculated based on Nash equilibrium. The game with limited detection capability is solved by maximizing the Close Point of Approach (CPA). The optimal solution will be found theoretically and numerically.","PeriodicalId":41412,"journal":{"name":"Mechatronic Systems and Control","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2019-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80635015","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}
M. Krieger, Dylan Stecklair, S. Peluso, S. Stockar
The ability to combine energy sources with intermittent performance with more consistent form of power is crucial for increasing the penetration of renewable energy sources in the electricity and heat generation sector. In this scenario, district heating networks are a promising solution but, to benefit the most from this technology, control tools must be developed with the objective of optimizing the heating load to each of the buildings in the network, while rejecting external disturbances. One of the main challenges for control design and verification is the limited access to data and experimental platforms. In addition, real systems are subjected to a large number of exogenous inputs and tests repeatability for benchmarking is a challenge. To overcome this limitation, a scaled experimental set up has been developed. This paper discusses the design of the experimental setup of a simple heat distribution network as well as the derivation, calibration and validation of a simulation model. Simulation results show that the model error in predicting temperature is always below 1 %.
{"title":"Design and Verification of a Small-Scale District Heating Network Experiment","authors":"M. Krieger, Dylan Stecklair, S. Peluso, S. Stockar","doi":"10.1115/dscc2019-9101","DOIUrl":"https://doi.org/10.1115/dscc2019-9101","url":null,"abstract":"\u0000 The ability to combine energy sources with intermittent performance with more consistent form of power is crucial for increasing the penetration of renewable energy sources in the electricity and heat generation sector. In this scenario, district heating networks are a promising solution but, to benefit the most from this technology, control tools must be developed with the objective of optimizing the heating load to each of the buildings in the network, while rejecting external disturbances. One of the main challenges for control design and verification is the limited access to data and experimental platforms. In addition, real systems are subjected to a large number of exogenous inputs and tests repeatability for benchmarking is a challenge. To overcome this limitation, a scaled experimental set up has been developed. This paper discusses the design of the experimental setup of a simple heat distribution network as well as the derivation, calibration and validation of a simulation model. Simulation results show that the model error in predicting temperature is always below 1 %.","PeriodicalId":41412,"journal":{"name":"Mechatronic Systems and Control","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2019-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86093320","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}
Cooperative transportation by multiple Unmanned Aerial Vehicles (UAVs) has been a topic of interest amongst robotics researchers since a decade. Researchers have developed different control schemes to address some of the issues related to cooperative transport. However, most of the existing control strategies assume a stationary center of gravity (CG) coinciding with the geometric center of the payload. In real world applications such as package delivery or human transport, position of CG, in general, would not be at geometric center, or would not be even known a – priori. This paper proposes a Proportional, Integral and Derivative (PID) controller to address the issue of control when the CG is offset during transportation of a common payload using multiple UAVs. The proposed PID scheme is centralized in nature in that it provides the same control action to all UAVs. Using extensive numerical simulations, the paper shows that such a scheme is shown to work effectively irrespective of the location of CG on the payload. The control scheme is also independent of the payload geometry and number of UAVs employed for cooperative transport. The work presented in this paper provides the groundwork to develop better control strategies to solve the problem of multi-UAV cooperative transport with a – priori unknown CG.
{"title":"Cooperative Transport of a Payload With Offset CG Using Multiple UAVs","authors":"Shraddha Barawkar, Manish Kumar","doi":"10.1115/dscc2019-9131","DOIUrl":"https://doi.org/10.1115/dscc2019-9131","url":null,"abstract":"\u0000 Cooperative transportation by multiple Unmanned Aerial Vehicles (UAVs) has been a topic of interest amongst robotics researchers since a decade. Researchers have developed different control schemes to address some of the issues related to cooperative transport. However, most of the existing control strategies assume a stationary center of gravity (CG) coinciding with the geometric center of the payload. In real world applications such as package delivery or human transport, position of CG, in general, would not be at geometric center, or would not be even known a – priori. This paper proposes a Proportional, Integral and Derivative (PID) controller to address the issue of control when the CG is offset during transportation of a common payload using multiple UAVs. The proposed PID scheme is centralized in nature in that it provides the same control action to all UAVs. Using extensive numerical simulations, the paper shows that such a scheme is shown to work effectively irrespective of the location of CG on the payload. The control scheme is also independent of the payload geometry and number of UAVs employed for cooperative transport. The work presented in this paper provides the groundwork to develop better control strategies to solve the problem of multi-UAV cooperative transport with a – priori unknown CG.","PeriodicalId":41412,"journal":{"name":"Mechatronic Systems and Control","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2019-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87750280","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}
Publisher’s Note: This paper was selected for publication in ASME Letters in Dynamic Systems and Control. https://www.asmedigitalcollection.asme.org/lettersdynsys/article/doi/10.1115/1.4046778/1082076/Modeling-and-Simulation-of-Perching-With-a
{"title":"Modelling and Simulation of Perching With a Quadrotor Aerial Robot With Passive Bio-Inspired Legs and Feet","authors":"David J. Dunlop, M. Minor","doi":"10.1115/dscc2019-9241","DOIUrl":"https://doi.org/10.1115/dscc2019-9241","url":null,"abstract":"\u0000 Publisher’s Note:\u0000 This paper was selected for publication in ASME Letters in Dynamic Systems and Control.\u0000 https://www.asmedigitalcollection.asme.org/lettersdynsys/article/doi/10.1115/1.4046778/1082076/Modeling-and-Simulation-of-Perching-With-a","PeriodicalId":41412,"journal":{"name":"Mechatronic Systems and Control","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2019-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75387217","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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