Pub Date : 2007-03-03DOI: 10.1109/AERO.2007.352721
J. Chambliss
NASA's exploration life support (ELS) project is providing technology development to address air, water and waste product handling for future exploration vehicles. Existing life support technology and processes need to improve to enable exploration vehicles to meet mission goals. The weight, volume, power and thermal control required, reliability, crew time and life cycle cost are the primary targets for ELS technology development improvements. An overview of the ELS technologies being developed leads into an evaluation of the benefits the ELS technology developments offer.
{"title":"Exploration Life Support Overview and Benefits","authors":"J. Chambliss","doi":"10.1109/AERO.2007.352721","DOIUrl":"https://doi.org/10.1109/AERO.2007.352721","url":null,"abstract":"NASA's exploration life support (ELS) project is providing technology development to address air, water and waste product handling for future exploration vehicles. Existing life support technology and processes need to improve to enable exploration vehicles to meet mission goals. The weight, volume, power and thermal control required, reliability, crew time and life cycle cost are the primary targets for ELS technology development improvements. An overview of the ELS technologies being developed leads into an evaluation of the benefits the ELS technology developments offer.","PeriodicalId":6295,"journal":{"name":"2007 IEEE Aerospace Conference","volume":"46 1","pages":"1-11"},"PeriodicalIF":0.0,"publicationDate":"2007-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90544945","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 : 2007-03-03DOI: 10.1109/AERO.2007.352660
S. Jerebets
As an important component in NASA's new frontiers program, the Jupiter polar orbiter (Juno) mission is designed to investigate in-depth physical properties of Jupiter. It will include the giant planet's ice-rock core and atmospheric studies as well as exploration of its polar magnetosphere. It will also provide the opportunity to understand the origin of the Jovian magnetic field. Due to severe radiation environment of the Jovian system, this mission inherently presents a significant technical challenge to attitude control system (ACS) design since the ACS sensors must survive and function properly to reliably maneuver the spacecraft throughout the mission. Different gyro technologies and their critical performance characteristics are discussed, compared and evaluated to facilitate a choice of appropriate gyro-based inertial measurement unit to operate in a harsh Jovian environment to assure mission success.
{"title":"Gyro Evaluation for the Mission to Jupiter","authors":"S. Jerebets","doi":"10.1109/AERO.2007.352660","DOIUrl":"https://doi.org/10.1109/AERO.2007.352660","url":null,"abstract":"As an important component in NASA's new frontiers program, the Jupiter polar orbiter (Juno) mission is designed to investigate in-depth physical properties of Jupiter. It will include the giant planet's ice-rock core and atmospheric studies as well as exploration of its polar magnetosphere. It will also provide the opportunity to understand the origin of the Jovian magnetic field. Due to severe radiation environment of the Jovian system, this mission inherently presents a significant technical challenge to attitude control system (ACS) design since the ACS sensors must survive and function properly to reliably maneuver the spacecraft throughout the mission. Different gyro technologies and their critical performance characteristics are discussed, compared and evaluated to facilitate a choice of appropriate gyro-based inertial measurement unit to operate in a harsh Jovian environment to assure mission success.","PeriodicalId":6295,"journal":{"name":"2007 IEEE Aerospace Conference","volume":"25 1","pages":"1-9"},"PeriodicalIF":0.0,"publicationDate":"2007-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73499885","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 : 2007-03-03DOI: 10.1109/AERO.2007.352810
M. Petersson
The embedded Fault Isolation functionality in the Saab JAS39 Gripen aircraft has been designed to accurately and reliably provide the technician with proposed maintenance procedures. A previously identified drawback and built in limitation has been the significant lead time for Fault Isolation functional changes based on aircraft operational statistics and line experience. With the Fault Isolation executing as compiled source code, changes and corrections require adaptation of the regular onboard systems computer software and careful planning of code and documentation releases, implying not only significant delays, but also high costs for necessary updates. The "Sandra" project aims at even further refine - and to introduce a state of the art - fault isolation maintenance concept for the Saab JAS39 Gripen aircraft. Based on an easy-to-use PC based graphical tool, Fault Isolation on dedicated aircraft monitoring and safety check result data is specified. Output in the form of design documentation artifacts, such as flowcharts and technical publications, is generated. The contained Fault Isolation object data is updated in parallel with the regular onboard computer software development process and the corresponding Loadable Data File will be delivered when convenient. The PC application constitutes the maintenance engineer's primary Fault Isolation design tool. The tool enables the maintenance engineer to select dedicated settings via a graphical user interface and use logical expressions to propose detailed and specific maintenance actions to be performed by the aircraft technician. The tool is capable of verifying a complete set of design documents towards the content of a generated loadable file. Thus, a generated output file with a minimum of additional verification can be delivered to be loaded into the aircraft. This new approach implies that the lead time for a Fault Isolation functional change can be reduced by as much as 80 %. The cost for the corresponding functional change will decrease by more than 50 %.
{"title":"Sandra - A New Concept for Management of Fault Isolation in Aircraft Systems","authors":"M. Petersson","doi":"10.1109/AERO.2007.352810","DOIUrl":"https://doi.org/10.1109/AERO.2007.352810","url":null,"abstract":"The embedded Fault Isolation functionality in the Saab JAS39 Gripen aircraft has been designed to accurately and reliably provide the technician with proposed maintenance procedures. A previously identified drawback and built in limitation has been the significant lead time for Fault Isolation functional changes based on aircraft operational statistics and line experience. With the Fault Isolation executing as compiled source code, changes and corrections require adaptation of the regular onboard systems computer software and careful planning of code and documentation releases, implying not only significant delays, but also high costs for necessary updates. The \"Sandra\" project aims at even further refine - and to introduce a state of the art - fault isolation maintenance concept for the Saab JAS39 Gripen aircraft. Based on an easy-to-use PC based graphical tool, Fault Isolation on dedicated aircraft monitoring and safety check result data is specified. Output in the form of design documentation artifacts, such as flowcharts and technical publications, is generated. The contained Fault Isolation object data is updated in parallel with the regular onboard computer software development process and the corresponding Loadable Data File will be delivered when convenient. The PC application constitutes the maintenance engineer's primary Fault Isolation design tool. The tool enables the maintenance engineer to select dedicated settings via a graphical user interface and use logical expressions to propose detailed and specific maintenance actions to be performed by the aircraft technician. The tool is capable of verifying a complete set of design documents towards the content of a generated loadable file. Thus, a generated output file with a minimum of additional verification can be delivered to be loaded into the aircraft. This new approach implies that the lead time for a Fault Isolation functional change can be reduced by as much as 80 %. The cost for the corresponding functional change will decrease by more than 50 %.","PeriodicalId":6295,"journal":{"name":"2007 IEEE Aerospace Conference","volume":"16 1","pages":"1-8"},"PeriodicalIF":0.0,"publicationDate":"2007-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78026613","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 : 2007-03-03DOI: 10.1109/AERO.2007.352989
B. Lewis, J. Lang, R. Jolly
Design groups have worked for many years to provide rapid development and modeling of conceptual space vehicles using Concurrent Engineering Models (CEMs). A large number of design tools have been crafted to meet different aims and goals within the systems engineering community.The challenges to build upon these previous models to generate a flexible CEM capable of using interchangeable modules that model the subsystems of a space vehicle are described in this paper. Rather than redeveloping entire CEMs to fit specific purposes, users and developers can focus their attention on crafting only the new modules they need while making use of other pre-existing modules. In this way, the Modular CEM can take advantage of many of the lessons learned in previous CEM development efforts. The new Modular CEM is designed to incorporate some error checking to help the systems engineer correctly use the model, to facilitate easy addition or extraction of data into or out of the model, and to incorporate improvements in ease of use and ease of development. This paper describes the relationship of this model to previously developed CEMs, the modeling approach taken by the design team, the current state of the Modular CEM, and describes applications where the Modular CEM has been applied.
{"title":"Modular Concurrent Engineering Models: Enabling Alternative Models in Conceptual Satellite Design","authors":"B. Lewis, J. Lang, R. Jolly","doi":"10.1109/AERO.2007.352989","DOIUrl":"https://doi.org/10.1109/AERO.2007.352989","url":null,"abstract":"Design groups have worked for many years to provide rapid development and modeling of conceptual space vehicles using Concurrent Engineering Models (CEMs). A large number of design tools have been crafted to meet different aims and goals within the systems engineering community.The challenges to build upon these previous models to generate a flexible CEM capable of using interchangeable modules that model the subsystems of a space vehicle are described in this paper. Rather than redeveloping entire CEMs to fit specific purposes, users and developers can focus their attention on crafting only the new modules they need while making use of other pre-existing modules. In this way, the Modular CEM can take advantage of many of the lessons learned in previous CEM development efforts. The new Modular CEM is designed to incorporate some error checking to help the systems engineer correctly use the model, to facilitate easy addition or extraction of data into or out of the model, and to incorporate improvements in ease of use and ease of development. This paper describes the relationship of this model to previously developed CEMs, the modeling approach taken by the design team, the current state of the Modular CEM, and describes applications where the Modular CEM has been applied.","PeriodicalId":6295,"journal":{"name":"2007 IEEE Aerospace Conference","volume":"30 1","pages":"1-8"},"PeriodicalIF":0.0,"publicationDate":"2007-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74970429","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 : 2007-03-03DOI: 10.1109/AERO.2007.352675
Sally A. McBrearty
{"title":"How Smart Were Early Humans?","authors":"Sally A. McBrearty","doi":"10.1109/AERO.2007.352675","DOIUrl":"https://doi.org/10.1109/AERO.2007.352675","url":null,"abstract":"","PeriodicalId":6295,"journal":{"name":"2007 IEEE Aerospace Conference","volume":"30 1","pages":"1-2"},"PeriodicalIF":0.0,"publicationDate":"2007-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75542469","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 : 2007-03-03DOI: 10.1109/AERO.2007.352647
B. Jackson
This paper presents a robust fault protection strategy for a low-cost single-string spacecraft that makes extensive use of COTS components. These components include commercial processors and microcontrollers that would traditionally be considered inappropriate for use in space. By crafting an avionics architecture that employs multiple distributed processors, and coupling this with an appropriate fault protection strategy, even a single-string COTS-based spacecraft can be made reasonably robust. The fault protection strategy is designed to trap faults at the highest possible level while preserving the maximum amount of spacecraft functionality, and can autonomously isolate and correct minor faults without ground intervention. For more serious faults, the vehicle is always placed in a safe configuration until the ground can diagnose the anomaly and recover the spacecraft. This paper will show how a multi-tiered fault protection strategy can be used to mitigate the risk of flying COTS components that were never intended for use in the space environment.
{"title":"A Robust Fault Protection Strategy for a COTS-Based Spacecraft","authors":"B. Jackson","doi":"10.1109/AERO.2007.352647","DOIUrl":"https://doi.org/10.1109/AERO.2007.352647","url":null,"abstract":"This paper presents a robust fault protection strategy for a low-cost single-string spacecraft that makes extensive use of COTS components. These components include commercial processors and microcontrollers that would traditionally be considered inappropriate for use in space. By crafting an avionics architecture that employs multiple distributed processors, and coupling this with an appropriate fault protection strategy, even a single-string COTS-based spacecraft can be made reasonably robust. The fault protection strategy is designed to trap faults at the highest possible level while preserving the maximum amount of spacecraft functionality, and can autonomously isolate and correct minor faults without ground intervention. For more serious faults, the vehicle is always placed in a safe configuration until the ground can diagnose the anomaly and recover the spacecraft. This paper will show how a multi-tiered fault protection strategy can be used to mitigate the risk of flying COTS components that were never intended for use in the space environment.","PeriodicalId":6295,"journal":{"name":"2007 IEEE Aerospace Conference","volume":"103 1","pages":"1-11"},"PeriodicalIF":0.0,"publicationDate":"2007-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74820541","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 : 2007-03-03DOI: 10.1109/AERO.2007.352829
D. He, Shenliang Wu, Eric Bechhoefer
Usage monitoring entails determining the actual usage of a component on the aircraft and requires accurate recognition of regimes. In this paper, a data mining approach is adopted for regime recognition. In particular, a regime recognition algorithm developed based on hidden Markov models is presented. The developed algorithm was validated using the flight card data of an Army UH-60L helicopter. The performance of this regime recognition algorithm was also compared with other data mining methods using the same dataset. Using the flight card information and regime definitions, a dataset of about 56,000 data points labeled with 50 regimes recorded in the flight card were mapped to the health and usage monitoring parameters. The validation and performance comparison results have showed that the hidden Markov model based regime recognition algorithm was able to accurately recognize the regimes recorded in the flight card data and outperformed other data mining methods.
{"title":"Development of Regime Recognition Tools for Usage Monitoring","authors":"D. He, Shenliang Wu, Eric Bechhoefer","doi":"10.1109/AERO.2007.352829","DOIUrl":"https://doi.org/10.1109/AERO.2007.352829","url":null,"abstract":"Usage monitoring entails determining the actual usage of a component on the aircraft and requires accurate recognition of regimes. In this paper, a data mining approach is adopted for regime recognition. In particular, a regime recognition algorithm developed based on hidden Markov models is presented. The developed algorithm was validated using the flight card data of an Army UH-60L helicopter. The performance of this regime recognition algorithm was also compared with other data mining methods using the same dataset. Using the flight card information and regime definitions, a dataset of about 56,000 data points labeled with 50 regimes recorded in the flight card were mapped to the health and usage monitoring parameters. The validation and performance comparison results have showed that the hidden Markov model based regime recognition algorithm was able to accurately recognize the regimes recorded in the flight card data and outperformed other data mining methods.","PeriodicalId":6295,"journal":{"name":"2007 IEEE Aerospace Conference","volume":"28 1","pages":"1-11"},"PeriodicalIF":0.0,"publicationDate":"2007-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73119215","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 : 2007-03-03DOI: 10.1109/AERO.2007.352881
A. Usynin, J. Hines, A. Urmanov
This paper proposes a methodology for formulating prognostics requirements for designers of electronic prognostics (EP)-enabled systems. A usefulness criterion is introduced that enables the specification of admissible uncertainty bounds on measurements of systems' health/degradation parameters. Keeping the uncertainty of health estimation below the admissible levels assures more accurate individual remaining useful life (RUL) estimations than those based on traditional population average time-to-failure. The proposed methodology is demonstrated using the well-known cumulative damage model that was extended to incorporate individual degradation data.
{"title":"Formulation of Prognostics Requirements","authors":"A. Usynin, J. Hines, A. Urmanov","doi":"10.1109/AERO.2007.352881","DOIUrl":"https://doi.org/10.1109/AERO.2007.352881","url":null,"abstract":"This paper proposes a methodology for formulating prognostics requirements for designers of electronic prognostics (EP)-enabled systems. A usefulness criterion is introduced that enables the specification of admissible uncertainty bounds on measurements of systems' health/degradation parameters. Keeping the uncertainty of health estimation below the admissible levels assures more accurate individual remaining useful life (RUL) estimations than those based on traditional population average time-to-failure. The proposed methodology is demonstrated using the well-known cumulative damage model that was extended to incorporate individual degradation data.","PeriodicalId":6295,"journal":{"name":"2007 IEEE Aerospace Conference","volume":"5 1","pages":"1-8"},"PeriodicalIF":0.0,"publicationDate":"2007-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72749791","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 : 2007-03-03DOI: 10.1109/AERO.2007.352948
M. Watson, S.B. Johnson
With the increasing capability of computers, engineers have designed vehicles to perform ever more complex tasks. Whether fully automated, as with robotic space probes, or partially automated in conjunction with a crew, vehicles have become both more complex and more capable. To manage this complexity, designers have developed increasingly sophisticated vehicle management systems (VMS) to manage vehicle internal states, and to operate in its external environment. While often effective, design of VMSs has often been on an ad hoc basis. Using insights from information theory, complexity theory, and artificial intelligence, this paper develops a theoretical framework in which to understand the nature of VMSs. The theory defines the interaction of VMS functions and provides a mathematical formulation to assess the complexity of different VMS configurations.
{"title":"A Theory of Vehicle Management Systems","authors":"M. Watson, S.B. Johnson","doi":"10.1109/AERO.2007.352948","DOIUrl":"https://doi.org/10.1109/AERO.2007.352948","url":null,"abstract":"With the increasing capability of computers, engineers have designed vehicles to perform ever more complex tasks. Whether fully automated, as with robotic space probes, or partially automated in conjunction with a crew, vehicles have become both more complex and more capable. To manage this complexity, designers have developed increasingly sophisticated vehicle management systems (VMS) to manage vehicle internal states, and to operate in its external environment. While often effective, design of VMSs has often been on an ad hoc basis. Using insights from information theory, complexity theory, and artificial intelligence, this paper develops a theoretical framework in which to understand the nature of VMSs. The theory defines the interaction of VMS functions and provides a mathematical formulation to assess the complexity of different VMS configurations.","PeriodicalId":6295,"journal":{"name":"2007 IEEE Aerospace Conference","volume":"5 1","pages":"1-8"},"PeriodicalIF":0.0,"publicationDate":"2007-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74620079","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 : 2007-03-03DOI: 10.1109/AERO.2007.352928
G. Weaver, B. Kantsiper
The future of both lunar and planetary missions will involve the use of an increasing number of orbiters, landers and robotic rovers with ever expanding objectives over greater land area range. The coordination of these individual assets into a system capable of supporting complex exploration activities will necessarily require a local timekeeping system able to directly assist navigation, event synchronization and trunk communication back to Earth. The Johns Hopkins University Applied Physics Laboratory (JHU/APL) has derived a method for disciplining quartz Ultra-stable Oscillators (USO) to extend its superior frequency stability from 10 seconds to nearly 30 days of operating time. This is accomplished through a Kalman estimator that optimally removes the drift of the free running USO. The accuracy of the estimator is improved by periodically comparing the frequency of the USO to an atomic reference, typically located on the Earth, and transferring its accuracy to the timekeeping system via periodic uplink sessions. This is a method most frequently known as 'disciplining an oscillator'. JHU/APL will report on the accuracy of a disciplined USO that maintains better than plusmn1.5 mu seconds over 30 days and describe our roadmap toward a robust, timekeeping system capable of providing both short-term and long-term frequency stability for lunar and planetary navigation infrastructure and timekeeping.
{"title":"Developments Toward a Disciplined Timekeeping System for Lunar and Planetary Navigation","authors":"G. Weaver, B. Kantsiper","doi":"10.1109/AERO.2007.352928","DOIUrl":"https://doi.org/10.1109/AERO.2007.352928","url":null,"abstract":"The future of both lunar and planetary missions will involve the use of an increasing number of orbiters, landers and robotic rovers with ever expanding objectives over greater land area range. The coordination of these individual assets into a system capable of supporting complex exploration activities will necessarily require a local timekeeping system able to directly assist navigation, event synchronization and trunk communication back to Earth. The Johns Hopkins University Applied Physics Laboratory (JHU/APL) has derived a method for disciplining quartz Ultra-stable Oscillators (USO) to extend its superior frequency stability from 10 seconds to nearly 30 days of operating time. This is accomplished through a Kalman estimator that optimally removes the drift of the free running USO. The accuracy of the estimator is improved by periodically comparing the frequency of the USO to an atomic reference, typically located on the Earth, and transferring its accuracy to the timekeeping system via periodic uplink sessions. This is a method most frequently known as 'disciplining an oscillator'. JHU/APL will report on the accuracy of a disciplined USO that maintains better than plusmn1.5 mu seconds over 30 days and describe our roadmap toward a robust, timekeeping system capable of providing both short-term and long-term frequency stability for lunar and planetary navigation infrastructure and timekeeping.","PeriodicalId":6295,"journal":{"name":"2007 IEEE Aerospace Conference","volume":"28 1","pages":"1-9"},"PeriodicalIF":0.0,"publicationDate":"2007-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73884593","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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