Pub Date : 1994-10-30DOI: 10.1109/DASC.1994.369504
P.B. Hugge, J. Lang
A team of Air Force, McDonnell Douglas Aerospace (MDA), and Hughes Aerospace and Electronics Company personnel has developed and is implementing a new avionics design and development-process that satisfies demands due to reduced budgets and manpower. The process is called Advanced Design for Quality Avionic Systems (ADQAS). It includes well-defined steps and a guide or roadmap to direct the efforts of Integrated Product Development (IPD) teams in designing and manufacturing avionics products. The teams tailor their processes to the product and measure progress against predetermined exit criteria for each phase. Several characteristics distinguish ADQAS from current approaches to avionics development. A systematic approach to requirements definition maintains traceability to customer needs and emphasizes a customer-defined balance of performance, supportability, and cost specific issues, such as diagnostics and testability requirements and manufacturing process definition, are also emphasized. Competing requirements are continuously refined and balanced through documented trade studies, where the impact of design decisions on subsystem and system characteristics is continuously assessed. The focus on balance continues throughout the preliminary and detail design phases. Definition of the manufacturing process and a clear characterization of its margin and variability parameters is required. Equipment design simultaneously emphasizes the capability for long-term operation in the user's environment and the minimization of variability through the control of manufacturing processes. The product development, verification, and production phases continue the focus on careful verification of product and process attributes and on variability reduction. Implementation of the ADQAS process is underway on several F-15 development programs. Status and results achieved highlight the benefits which can be realized with this process.<>
{"title":"Advanced design for quality avionic systems: a new systems development guide","authors":"P.B. Hugge, J. Lang","doi":"10.1109/DASC.1994.369504","DOIUrl":"https://doi.org/10.1109/DASC.1994.369504","url":null,"abstract":"A team of Air Force, McDonnell Douglas Aerospace (MDA), and Hughes Aerospace and Electronics Company personnel has developed and is implementing a new avionics design and development-process that satisfies demands due to reduced budgets and manpower. The process is called Advanced Design for Quality Avionic Systems (ADQAS). It includes well-defined steps and a guide or roadmap to direct the efforts of Integrated Product Development (IPD) teams in designing and manufacturing avionics products. The teams tailor their processes to the product and measure progress against predetermined exit criteria for each phase. Several characteristics distinguish ADQAS from current approaches to avionics development. A systematic approach to requirements definition maintains traceability to customer needs and emphasizes a customer-defined balance of performance, supportability, and cost specific issues, such as diagnostics and testability requirements and manufacturing process definition, are also emphasized. Competing requirements are continuously refined and balanced through documented trade studies, where the impact of design decisions on subsystem and system characteristics is continuously assessed. The focus on balance continues throughout the preliminary and detail design phases. Definition of the manufacturing process and a clear characterization of its margin and variability parameters is required. Equipment design simultaneously emphasizes the capability for long-term operation in the user's environment and the minimization of variability through the control of manufacturing processes. The product development, verification, and production phases continue the focus on careful verification of product and process attributes and on variability reduction. Implementation of the ADQAS process is underway on several F-15 development programs. Status and results achieved highlight the benefits which can be realized with this process.<<ETX>>","PeriodicalId":246447,"journal":{"name":"AIAA/IEEE Digital Avionics Systems Conference. 13th DASC","volume":"189 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115270562","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 : 1994-10-30DOI: 10.1109/DASC.1994.369477
A. Helfrick
The possibility of interference due to electromagnetic radiation from portable consumer-type electronic devices has been known for some time. Until recently, there has not been significant problems with interference primarily due to the low frequency and low energy circuits typically found in battery-operated portable equipment. With the steadily increasing clock speeds of so-called "lap top" computers, the potential for interference is, also, steadily increasing. Determining the magnitude of the problem involves the generation of three data bases. First, is the radiation levels of personal electronic devices. Second, is the susceptibility of various avionics systems to degradation from electromagnetic radiation. Finally, the attenuation from within the aircraft cabin to the location of the affected navigation system ingress point must be known. There is virtually an infinite number of permutations of emitter, attenuation, and receptor. This paper outlines the interference problem and addresses the generation of the necessary statistics to fully study the problem. Some of the measurement techniques are discussed along with some of the typical data. This work is being performed in conjunction with RTCA special committee, SC-177.<>
{"title":"Interference to digital avionics due to electromagnetic radiation from personal electronic devices carried aboard aircraft","authors":"A. Helfrick","doi":"10.1109/DASC.1994.369477","DOIUrl":"https://doi.org/10.1109/DASC.1994.369477","url":null,"abstract":"The possibility of interference due to electromagnetic radiation from portable consumer-type electronic devices has been known for some time. Until recently, there has not been significant problems with interference primarily due to the low frequency and low energy circuits typically found in battery-operated portable equipment. With the steadily increasing clock speeds of so-called \"lap top\" computers, the potential for interference is, also, steadily increasing. Determining the magnitude of the problem involves the generation of three data bases. First, is the radiation levels of personal electronic devices. Second, is the susceptibility of various avionics systems to degradation from electromagnetic radiation. Finally, the attenuation from within the aircraft cabin to the location of the affected navigation system ingress point must be known. There is virtually an infinite number of permutations of emitter, attenuation, and receptor. This paper outlines the interference problem and addresses the generation of the necessary statistics to fully study the problem. Some of the measurement techniques are discussed along with some of the typical data. This work is being performed in conjunction with RTCA special committee, SC-177.<<ETX>>","PeriodicalId":246447,"journal":{"name":"AIAA/IEEE Digital Avionics Systems Conference. 13th DASC","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121699960","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 : 1994-10-30DOI: 10.1109/DASC.1994.369472
J. Eichenlaub, T. Touris
Studies have shown that pilot performance is improved by up to 44% in certain tasks when situational awareness information, on an electronic display, is presented in stereoscopic (3D) format. The United States Air Force has also indicated that LCDs are preferable to CRTs in the cockpit due to their smaller volume, power, and weight. With these efficiencies in mind, DTI has designed and built a prototype autostereoscopic cockpit situation awareness display that generates three dimensional images using an LCD. The pilot can see the 3D images without special glasses from anywhere within a wide viewing volume in front of the LCD. DTI's autostereoscopic displays are particularly well suited to presenting symbology in 3D space, and flight path information for low visibility, high speed, and low level flying.<>
{"title":"An in cockpit 'situation awareness' autostereoscopic avionics display","authors":"J. Eichenlaub, T. Touris","doi":"10.1109/DASC.1994.369472","DOIUrl":"https://doi.org/10.1109/DASC.1994.369472","url":null,"abstract":"Studies have shown that pilot performance is improved by up to 44% in certain tasks when situational awareness information, on an electronic display, is presented in stereoscopic (3D) format. The United States Air Force has also indicated that LCDs are preferable to CRTs in the cockpit due to their smaller volume, power, and weight. With these efficiencies in mind, DTI has designed and built a prototype autostereoscopic cockpit situation awareness display that generates three dimensional images using an LCD. The pilot can see the 3D images without special glasses from anywhere within a wide viewing volume in front of the LCD. DTI's autostereoscopic displays are particularly well suited to presenting symbology in 3D space, and flight path information for low visibility, high speed, and low level flying.<<ETX>>","PeriodicalId":246447,"journal":{"name":"AIAA/IEEE Digital Avionics Systems Conference. 13th DASC","volume":"310 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122732348","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 : 1994-10-30DOI: 10.1109/DASC.1994.369473
D. G. Hopper
There are no standards, commercial or military, for active matrix liquid crystal displays (AMLCDs). One is being developed to provide guidance to procurement programs for U.S. Military airborne cockpit applications. Other applications will have less severe requirements which would affect backlight and design, including mission and cabin displays. A draft standard comprising recommended best practices has been published. It is useful to procurement programs in drafting their performance specification, to integrators in determining if a commercial specification can meet that performance specification, and to industry in the establishment of common AMLCDs in military aircraft and common AMLCD design elements wherever possible across all civil and military avionic applications.<>
{"title":"Draft performance standard for color AMLCDs in U.S. military aircraft: recommended best practice","authors":"D. G. Hopper","doi":"10.1109/DASC.1994.369473","DOIUrl":"https://doi.org/10.1109/DASC.1994.369473","url":null,"abstract":"There are no standards, commercial or military, for active matrix liquid crystal displays (AMLCDs). One is being developed to provide guidance to procurement programs for U.S. Military airborne cockpit applications. Other applications will have less severe requirements which would affect backlight and design, including mission and cabin displays. A draft standard comprising recommended best practices has been published. It is useful to procurement programs in drafting their performance specification, to integrators in determining if a commercial specification can meet that performance specification, and to industry in the establishment of common AMLCDs in military aircraft and common AMLCD design elements wherever possible across all civil and military avionic applications.<<ETX>>","PeriodicalId":246447,"journal":{"name":"AIAA/IEEE Digital Avionics Systems Conference. 13th DASC","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131198612","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 : 1994-10-30DOI: 10.1109/DASC.1994.369513
T. Felke
This paper describes the application of model based diagnostic technology to the Central Maintenance Computer for the Boeing 777 Airplane. The paper presents an overview of model based diagnostic technology as applied to the 777 with an emphasis on the model generation process. It identifies the subtleties of developing a model with the appropriate level of resolution. A model that is too general will not provide the required accuracy while a model that is too detailed will be burdensome to develop and maintain. The fact that data entry activities for parts of the model needed to start before the model was completely specified was the source of additional difficulties that the process had to overcome. The paper presents how these problems were solved on the 777 and how this experience can be beneficial in future programs.<>
{"title":"Application of model-based diagnostic technology on the Boeing 777 Airplane","authors":"T. Felke","doi":"10.1109/DASC.1994.369513","DOIUrl":"https://doi.org/10.1109/DASC.1994.369513","url":null,"abstract":"This paper describes the application of model based diagnostic technology to the Central Maintenance Computer for the Boeing 777 Airplane. The paper presents an overview of model based diagnostic technology as applied to the 777 with an emphasis on the model generation process. It identifies the subtleties of developing a model with the appropriate level of resolution. A model that is too general will not provide the required accuracy while a model that is too detailed will be burdensome to develop and maintain. The fact that data entry activities for parts of the model needed to start before the model was completely specified was the source of additional difficulties that the process had to overcome. The paper presents how these problems were solved on the 777 and how this experience can be beneficial in future programs.<<ETX>>","PeriodicalId":246447,"journal":{"name":"AIAA/IEEE Digital Avionics Systems Conference. 13th DASC","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131515430","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 : 1994-10-30DOI: 10.1109/DASC.1994.369506
J. George, G. Kunstmann, S. Southard, E. Upchurch
In April 1991, Galileo's X-band high gain antenna failed to deploy. An alternate approach which utilizes the spacecraft's S-band low gain antenna was conceived and is in development. This approach will enable the accomplishment of at least 70 percent of Galileo's original scientific objectives. The short development period dictates that the spacecraft system design, the ground data system design, and the operational system scenarios and procedures necessary to conduct the mission be developed concurrently, and places a premium on validating the system designs as early as possible. This paper presents an overview of the Galileo mission, briefly describes the changes required to implement the orbital phase of the Galileo mission, and describes the functional model of the end to end system which was developed to support the systems design effort.<>
{"title":"Galileo system design for orbital operations","authors":"J. George, G. Kunstmann, S. Southard, E. Upchurch","doi":"10.1109/DASC.1994.369506","DOIUrl":"https://doi.org/10.1109/DASC.1994.369506","url":null,"abstract":"In April 1991, Galileo's X-band high gain antenna failed to deploy. An alternate approach which utilizes the spacecraft's S-band low gain antenna was conceived and is in development. This approach will enable the accomplishment of at least 70 percent of Galileo's original scientific objectives. The short development period dictates that the spacecraft system design, the ground data system design, and the operational system scenarios and procedures necessary to conduct the mission be developed concurrently, and places a premium on validating the system designs as early as possible. This paper presents an overview of the Galileo mission, briefly describes the changes required to implement the orbital phase of the Galileo mission, and describes the functional model of the end to end system which was developed to support the systems design effort.<<ETX>>","PeriodicalId":246447,"journal":{"name":"AIAA/IEEE Digital Avionics Systems Conference. 13th DASC","volume":"327 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133498245","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 : 1994-10-30DOI: 10.1109/DASC.1994.369502
L. Sherry
This paper describes a specification notation and specification methodology that use the operational procedure construct to formulate a complete description of a system. The specification that is generated captures the operation of the system, manages the evolution of the operation of the system, and facilitates the rapid formulation and adaptation of implementation models for software-based systems.<>
{"title":"A structured approach to requirements specification for software-based systems using operational procedures","authors":"L. Sherry","doi":"10.1109/DASC.1994.369502","DOIUrl":"https://doi.org/10.1109/DASC.1994.369502","url":null,"abstract":"This paper describes a specification notation and specification methodology that use the operational procedure construct to formulate a complete description of a system. The specification that is generated captures the operation of the system, manages the evolution of the operation of the system, and facilitates the rapid formulation and adaptation of implementation models for software-based systems.<<ETX>>","PeriodicalId":246447,"journal":{"name":"AIAA/IEEE Digital Avionics Systems Conference. 13th DASC","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133513518","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 : 1994-10-30DOI: 10.1109/DASC.1994.369437
M. Johnson, C. Rogers, W. Hancock, F. Rose, H. Spaanenburg, T. Carpenter, P. Dietrich, J. Ghrayeb
A key challenge to tomorrow's real-time 3D rendering engines has been the memory bandwidth barrier, which limits how fast an image can be painted onto image memory. Another has been the floating point throughput that limits how much world coordinate data can be mapped to the screen. Other traditional challenges remain. The 3D engine must be small, modular, and affordable so it can be integrated into tomorrow's vision systems easily. Ways to overcome these barriers are being developed by implementing novel 3D renderer prototypes on a new "software breadboard." The breadboard, implemented in C and VHDL, permits rapid evaluation of promising concepts using off-the-shelf models and high level structures. The breadboard, being developed under the auspices of Wright Laboratory, will help determine which functions should be implemented using ASICs. Breadboard benchmarks and associated analyses show that a single card, capable of rendering useful real-time "out-the-window" scenes, is feasible today. The "software breadboard" is being used to design tomorrow's real-time 3D renderers.<>
{"title":"Soft breadboard for real-time 3D rendering","authors":"M. Johnson, C. Rogers, W. Hancock, F. Rose, H. Spaanenburg, T. Carpenter, P. Dietrich, J. Ghrayeb","doi":"10.1109/DASC.1994.369437","DOIUrl":"https://doi.org/10.1109/DASC.1994.369437","url":null,"abstract":"A key challenge to tomorrow's real-time 3D rendering engines has been the memory bandwidth barrier, which limits how fast an image can be painted onto image memory. Another has been the floating point throughput that limits how much world coordinate data can be mapped to the screen. Other traditional challenges remain. The 3D engine must be small, modular, and affordable so it can be integrated into tomorrow's vision systems easily. Ways to overcome these barriers are being developed by implementing novel 3D renderer prototypes on a new \"software breadboard.\" The breadboard, implemented in C and VHDL, permits rapid evaluation of promising concepts using off-the-shelf models and high level structures. The breadboard, being developed under the auspices of Wright Laboratory, will help determine which functions should be implemented using ASICs. Breadboard benchmarks and associated analyses show that a single card, capable of rendering useful real-time \"out-the-window\" scenes, is feasible today. The \"software breadboard\" is being used to design tomorrow's real-time 3D renderers.<<ETX>>","PeriodicalId":246447,"journal":{"name":"AIAA/IEEE Digital Avionics Systems Conference. 13th DASC","volume":"86 3","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131873421","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 : 1994-10-30DOI: 10.1109/DASC.1994.369512
Stuart L Varner, T.D. Belle
A key ingredient to reduction of airline costs, and therefore increased profits, is to reduce the airline's fleet maintenance cost over the life of every airplane. This goal has become a challenge to meet because the rising complexity of avionics on commercial airplanes has led to an increased amount of information that must be readily accessible and understood by engineers, maintenance personnel, and flight crews in order to repair and maintain the fleet. To help the airlines streamline their airplane maintenance procedures, the Boeing Company, in conjunction with Honeywell Air Transport Systems, has developed the next generation Onboard Maintenance System (OMS) for the Boeing 777. Its graphical user interface, the Maintenance Terminal Function (MTF), provides much more capability and flexibility in the presentation of fault and performance monitoring data as compared to previous OMS systems that use a Control & Display Unit (CDU) to display information.<>
{"title":"Maintenance Terminal Function: the user interface for the Boeing 777 onboard maintenance system","authors":"Stuart L Varner, T.D. Belle","doi":"10.1109/DASC.1994.369512","DOIUrl":"https://doi.org/10.1109/DASC.1994.369512","url":null,"abstract":"A key ingredient to reduction of airline costs, and therefore increased profits, is to reduce the airline's fleet maintenance cost over the life of every airplane. This goal has become a challenge to meet because the rising complexity of avionics on commercial airplanes has led to an increased amount of information that must be readily accessible and understood by engineers, maintenance personnel, and flight crews in order to repair and maintain the fleet. To help the airlines streamline their airplane maintenance procedures, the Boeing Company, in conjunction with Honeywell Air Transport Systems, has developed the next generation Onboard Maintenance System (OMS) for the Boeing 777. Its graphical user interface, the Maintenance Terminal Function (MTF), provides much more capability and flexibility in the presentation of fault and performance monitoring data as compared to previous OMS systems that use a Control & Display Unit (CDU) to display information.<<ETX>>","PeriodicalId":246447,"journal":{"name":"AIAA/IEEE Digital Avionics Systems Conference. 13th DASC","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133274214","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 : 1994-10-30DOI: 10.1109/DASC.1994.369449
T. Brown, J. Donaldson
The Cassini orbital mission is to explore the Saturnian system are much greater depth than was possible by the Voyager flyby missions. To do this, the Cassini spacecraft is comprised of a Saturn orbiter and a Titan probe. The Command and Data Subsystem (CDS) on Cassini is responsible for uplink command processing, spacecraft intercommunications and control, and downlink telemetry formatting. The 10.7 year mission life, 160 minute round-trip light time, and extended periods of operation without continuous ground communications drive the CDS design in directions of redundancy, autonomy, and fault protection to assure the mission objectives.<>
{"title":"Fault protection design for the command and data subsystem on the Cassini spacecraft","authors":"T. Brown, J. Donaldson","doi":"10.1109/DASC.1994.369449","DOIUrl":"https://doi.org/10.1109/DASC.1994.369449","url":null,"abstract":"The Cassini orbital mission is to explore the Saturnian system are much greater depth than was possible by the Voyager flyby missions. To do this, the Cassini spacecraft is comprised of a Saturn orbiter and a Titan probe. The Command and Data Subsystem (CDS) on Cassini is responsible for uplink command processing, spacecraft intercommunications and control, and downlink telemetry formatting. The 10.7 year mission life, 160 minute round-trip light time, and extended periods of operation without continuous ground communications drive the CDS design in directions of redundancy, autonomy, and fault protection to assure the mission objectives.<<ETX>>","PeriodicalId":246447,"journal":{"name":"AIAA/IEEE Digital Avionics Systems Conference. 13th DASC","volume":"108 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117254203","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：