Pub Date : 2014-12-01DOI: 10.1109/MECHATRONIKA.2014.7018251
T. Kosan, Martin Jara, D. Janik, Z. Peroutka
This paper describes the modular development control platform including dedicated supporting tools. The platform was specially designed for the multi-level converters control therefore it provides up to 48 (plus 24 optional) of PWM outputs thanks to additional FPGA utilization. The combination of DSP enabled microcontroller and the FPGA allowed us to split the computational tasks between these parts which significantly helps with highly complex algorithms implementation. Fast application development is supported thanks to the software drivers covering broad range of elemental functions including communication, DMA transfers, AD service routines and basic user interface. Also an enhanced set of FPGA entities featuring various modulator functionalities are provided. Dedicated tools involves fully insulated JTAG interface with developed software allowing the platform to be programmed by a single JTAG emulator. An application example based on four level FLC converter is presented.
{"title":"Complete development platform for multi-level converters and complex control algorithms","authors":"T. Kosan, Martin Jara, D. Janik, Z. Peroutka","doi":"10.1109/MECHATRONIKA.2014.7018251","DOIUrl":"https://doi.org/10.1109/MECHATRONIKA.2014.7018251","url":null,"abstract":"This paper describes the modular development control platform including dedicated supporting tools. The platform was specially designed for the multi-level converters control therefore it provides up to 48 (plus 24 optional) of PWM outputs thanks to additional FPGA utilization. The combination of DSP enabled microcontroller and the FPGA allowed us to split the computational tasks between these parts which significantly helps with highly complex algorithms implementation. Fast application development is supported thanks to the software drivers covering broad range of elemental functions including communication, DMA transfers, AD service routines and basic user interface. Also an enhanced set of FPGA entities featuring various modulator functionalities are provided. Dedicated tools involves fully insulated JTAG interface with developed software allowing the platform to be programmed by a single JTAG emulator. An application example based on four level FLC converter is presented.","PeriodicalId":430829,"journal":{"name":"Proceedings of the 16th International Conference on Mechatronics - Mechatronika 2014","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114830528","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 : 2014-12-01DOI: 10.1109/MECHATRONIKA.2014.7018234
Bartlomiej Wicher, Krzysztof Siembab
The paper presents mathematical model of absolute optical encoder with parallel gray output where various parameters of the transducer can be modified (ex. number of bits, asymmetry in output waveforms, lack of signals from selected bits). The model of the non - ideal encoder substitutes the model of ideal position sensor implemented in Matlab/Simulink model of three phase PMSM (Permanent Magnet Synchronous Motor) drive with SVPWM (Space Vector Pulse Width Modulation) control algorithm. The author examines the impact of: asymmetry in output signals from the encoder and absence of signals from selected bits (simulation of damage of the transducer) to the static and dynamic properties of the drive in current and speed control loop mode. Selected methods of signal improvement were implemented in order reproduce the degradated position signal. The simulation results are verified by experiment. Quality indicators are proposed in order to determine the rate of damage of the encoder/drive. Conclusions and proposes of further research are presented.
{"title":"The impact of deterioration of the absolute position transducer on the electric drive with Permanent Magnet Synchronous Motor","authors":"Bartlomiej Wicher, Krzysztof Siembab","doi":"10.1109/MECHATRONIKA.2014.7018234","DOIUrl":"https://doi.org/10.1109/MECHATRONIKA.2014.7018234","url":null,"abstract":"The paper presents mathematical model of absolute optical encoder with parallel gray output where various parameters of the transducer can be modified (ex. number of bits, asymmetry in output waveforms, lack of signals from selected bits). The model of the non - ideal encoder substitutes the model of ideal position sensor implemented in Matlab/Simulink model of three phase PMSM (Permanent Magnet Synchronous Motor) drive with SVPWM (Space Vector Pulse Width Modulation) control algorithm. The author examines the impact of: asymmetry in output signals from the encoder and absence of signals from selected bits (simulation of damage of the transducer) to the static and dynamic properties of the drive in current and speed control loop mode. Selected methods of signal improvement were implemented in order reproduce the degradated position signal. The simulation results are verified by experiment. Quality indicators are proposed in order to determine the rate of damage of the encoder/drive. Conclusions and proposes of further research are presented.","PeriodicalId":430829,"journal":{"name":"Proceedings of the 16th International Conference on Mechatronics - Mechatronika 2014","volume":"98 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116277551","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 : 2014-12-01DOI: 10.1109/MECHATRONIKA.2014.7018324
Bohuslav Bušov, Radek Knoflicek, M. Bartlová
The best technical products are evaluated and awarded with different prices in the fairgrounds around the world. Evaluation Committees (Jury) have to solve difficult tasks: How to evaluate, in limited time, dozens of various technical objects which enter in the competition, how to objectify the subjective opinions of numerous individual experts. This paper presents only part of the evaluation procedure, namely definition of criteria for evaluation. The definition of these criteria is TRIZ based and should make the evaluation process of various exhibits more measurable and objective.
{"title":"Improvement the evaluation of innovation","authors":"Bohuslav Bušov, Radek Knoflicek, M. Bartlová","doi":"10.1109/MECHATRONIKA.2014.7018324","DOIUrl":"https://doi.org/10.1109/MECHATRONIKA.2014.7018324","url":null,"abstract":"The best technical products are evaluated and awarded with different prices in the fairgrounds around the world. Evaluation Committees (Jury) have to solve difficult tasks: How to evaluate, in limited time, dozens of various technical objects which enter in the competition, how to objectify the subjective opinions of numerous individual experts. This paper presents only part of the evaluation procedure, namely definition of criteria for evaluation. The definition of these criteria is TRIZ based and should make the evaluation process of various exhibits more measurable and objective.","PeriodicalId":430829,"journal":{"name":"Proceedings of the 16th International Conference on Mechatronics - Mechatronika 2014","volume":"204 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116068099","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 : 2014-12-01DOI: 10.1109/MECHATRONIKA.2014.7018277
R. Votrubec
This paper deals with the control system of pneumatic actuator in the seat with variable stiffness. The pressure in the element is measured by the pressure sensor. Input and output flow of air is controlled by two proportional valves and two discontinuous valves. Next it is operated accessories - compressor with pressure control in the attached reservoir. All components are implemented in the seat of the car. The control algorithm is designed in LabVIEW with a measuring card. It is planned to replace it by a microcontroller. Set the desired pressure is carried out in several modes. The simplest is a manual control using buttons. Next it is solved absolute or relative change of pressure. Another possibility is to regulate either at constant pressure or constant volume of air within element. We are currently working on semi-active control based on an online analysis of the frequency of the excitation signal.
{"title":"Control system of the seat with variable stiffness","authors":"R. Votrubec","doi":"10.1109/MECHATRONIKA.2014.7018277","DOIUrl":"https://doi.org/10.1109/MECHATRONIKA.2014.7018277","url":null,"abstract":"This paper deals with the control system of pneumatic actuator in the seat with variable stiffness. The pressure in the element is measured by the pressure sensor. Input and output flow of air is controlled by two proportional valves and two discontinuous valves. Next it is operated accessories - compressor with pressure control in the attached reservoir. All components are implemented in the seat of the car. The control algorithm is designed in LabVIEW with a measuring card. It is planned to replace it by a microcontroller. Set the desired pressure is carried out in several modes. The simplest is a manual control using buttons. Next it is solved absolute or relative change of pressure. Another possibility is to regulate either at constant pressure or constant volume of air within element. We are currently working on semi-active control based on an online analysis of the frequency of the excitation signal.","PeriodicalId":430829,"journal":{"name":"Proceedings of the 16th International Conference on Mechatronics - Mechatronika 2014","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124764776","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 : 2014-12-01DOI: 10.1109/MECHATRONIKA.2014.7018280
V. Čech, J. Jevicky, M. Jus
The Gun (Elevation) Stabilization Bump Course (GSBC) of the Aberdeen Proving Ground (APG) is a special road test track which is used for quality testing of the line-of-sight (LOS) stabilized devices which are mounted into military vehicles. There are optical devices, antennas and guns which are components of the fire control systems for example. The methodology for the quality testing of the LOS stabilized devices using the design of the GSBC is the basic standard for appropriate devices testing in all NATO countries. We present a simulation model of the vehicle passing the GSBC in our contribution. The Matlab model generates vibrations of suspended parts of the vehicle. These vibrations can be used as the inputs in simulators of the suspended parts movement or as the input in simulation models of the servos of the LOS stabilized devices. The spectral parameters of these vibrations are estimated, too.
{"title":"Simulation of the vehicle passing the Gun Stabilization Bump Course of the Aberdeen Proving Ground","authors":"V. Čech, J. Jevicky, M. Jus","doi":"10.1109/MECHATRONIKA.2014.7018280","DOIUrl":"https://doi.org/10.1109/MECHATRONIKA.2014.7018280","url":null,"abstract":"The Gun (Elevation) Stabilization Bump Course (GSBC) of the Aberdeen Proving Ground (APG) is a special road test track which is used for quality testing of the line-of-sight (LOS) stabilized devices which are mounted into military vehicles. There are optical devices, antennas and guns which are components of the fire control systems for example. The methodology for the quality testing of the LOS stabilized devices using the design of the GSBC is the basic standard for appropriate devices testing in all NATO countries. We present a simulation model of the vehicle passing the GSBC in our contribution. The Matlab model generates vibrations of suspended parts of the vehicle. These vibrations can be used as the inputs in simulators of the suspended parts movement or as the input in simulation models of the servos of the LOS stabilized devices. The spectral parameters of these vibrations are estimated, too.","PeriodicalId":430829,"journal":{"name":"Proceedings of the 16th International Conference on Mechatronics - Mechatronika 2014","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126109041","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 : 2014-12-01DOI: 10.1109/MECHATRONIKA.2014.7018348
M. Iskandirova, P. Blecha, Michal Holub, I. Dudarev
The ever-increasing power consumption and the associated consumption of non-renewable natural resources lead to an overall environmental degradation. Efforts to increase the energy efficiency, to reduce greenhouse gas emissions and the sustainable use of natural resources have a significant potential for improving the environment and its preservation for future generations. To realize this potential, it is however necessary to manage the assessment of the environmental impact of product design on the environment. Mechatronic systems (e.g. machinery, manipulators, actuators, and manufacturing machines ...) form significant industrial facilities and at the same time they also represent major appliances consuming the electrical energy, and during their entire life cycle they have a considerable impact on the environment. The most demanding industry sectors are: production of iron and steel, which are materials that are often used in the construction of mechatronic systems. The present article is devoted to the methodology of assessment of the effects of general mechatronic system on the environment. The environmental burden is presented in the form of carbon dioxide emissions caused by the production of selected construction materials.
{"title":"Assessing the impact of mechatronic systems on the environment","authors":"M. Iskandirova, P. Blecha, Michal Holub, I. Dudarev","doi":"10.1109/MECHATRONIKA.2014.7018348","DOIUrl":"https://doi.org/10.1109/MECHATRONIKA.2014.7018348","url":null,"abstract":"The ever-increasing power consumption and the associated consumption of non-renewable natural resources lead to an overall environmental degradation. Efforts to increase the energy efficiency, to reduce greenhouse gas emissions and the sustainable use of natural resources have a significant potential for improving the environment and its preservation for future generations. To realize this potential, it is however necessary to manage the assessment of the environmental impact of product design on the environment. Mechatronic systems (e.g. machinery, manipulators, actuators, and manufacturing machines ...) form significant industrial facilities and at the same time they also represent major appliances consuming the electrical energy, and during their entire life cycle they have a considerable impact on the environment. The most demanding industry sectors are: production of iron and steel, which are materials that are often used in the construction of mechatronic systems. The present article is devoted to the methodology of assessment of the effects of general mechatronic system on the environment. The environmental burden is presented in the form of carbon dioxide emissions caused by the production of selected construction materials.","PeriodicalId":430829,"journal":{"name":"Proceedings of the 16th International Conference on Mechatronics - Mechatronika 2014","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130396791","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 : 2014-12-01DOI: 10.1109/MECHATRONIKA.2014.7018266
J. Tuma, P. Blecha, Jiří Zahálka, Zdeněk Tůma
Machine tools are one of the most significant energy appliances in industry. Within their life cycle, the largest energy consumption occurs in the usage stage, when they serve their purpose. A possibility to estimate the power consumption in this phase of life will allow developers to reduce energy costs. A method of calculating the energy consumed during the usage phase of life shown in this article is based on the simulation of the machining cycle of the characteristic workpiece by multi-body system. The machine is presented as a system of rigid bodies that are connected to each other by mechanical constrains. Each moving part of the machine is defined by its mass, volume and moment of inertia; each constrain is defined by its efficiency. Using the NC code is defined by the tool path. The output of the simulation is the consumed mechanical energy. This approach allows the calculation of the total mechanical work which the machine must carry out to produce one characteristic workpiece. It is possible to obtain data for the calculation of total energy costs consumed during the usage phase of the machine life. Energy optimization is the next step in the development of the machine; this is created on the basis of the data obtained from this simulation.
{"title":"Prediction method for electrical energy consumption of the machine tool in the usage stage","authors":"J. Tuma, P. Blecha, Jiří Zahálka, Zdeněk Tůma","doi":"10.1109/MECHATRONIKA.2014.7018266","DOIUrl":"https://doi.org/10.1109/MECHATRONIKA.2014.7018266","url":null,"abstract":"Machine tools are one of the most significant energy appliances in industry. Within their life cycle, the largest energy consumption occurs in the usage stage, when they serve their purpose. A possibility to estimate the power consumption in this phase of life will allow developers to reduce energy costs. A method of calculating the energy consumed during the usage phase of life shown in this article is based on the simulation of the machining cycle of the characteristic workpiece by multi-body system. The machine is presented as a system of rigid bodies that are connected to each other by mechanical constrains. Each moving part of the machine is defined by its mass, volume and moment of inertia; each constrain is defined by its efficiency. Using the NC code is defined by the tool path. The output of the simulation is the consumed mechanical energy. This approach allows the calculation of the total mechanical work which the machine must carry out to produce one characteristic workpiece. It is possible to obtain data for the calculation of total energy costs consumed during the usage phase of the machine life. Energy optimization is the next step in the development of the machine; this is created on the basis of the data obtained from this simulation.","PeriodicalId":430829,"journal":{"name":"Proceedings of the 16th International Conference on Mechatronics - Mechatronika 2014","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122511251","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 : 2014-12-01DOI: 10.1109/MECHATRONIKA.2014.7018293
Kang Zhang, Pengxing Yi, Yahui Li, Xuming Zhang, Zailin Guan
The EMAT is a non-contact transducer, but it is sensitive to the lift off. To study the lift off effect on the feature cut off frequency in the Rayleigh wave, a finite element method (FEM) is used. Based on different hypotheses of the source current density, three formulations are realized with the simulation software COMSOL. Ignoring the skin and proximity effects will yield enormous errors. The results obtained with the complete formulation are relatively accurate. A two dimensions (2D) EMAT transmitting model is built upon the complete formulation. On the basis of the 2D model, the lift off effect on the feature cut off frequency is investigated in detail.
{"title":"Numerical investigation of the lift-off effect on the cut-off frequency in the Rayleigh wave","authors":"Kang Zhang, Pengxing Yi, Yahui Li, Xuming Zhang, Zailin Guan","doi":"10.1109/MECHATRONIKA.2014.7018293","DOIUrl":"https://doi.org/10.1109/MECHATRONIKA.2014.7018293","url":null,"abstract":"The EMAT is a non-contact transducer, but it is sensitive to the lift off. To study the lift off effect on the feature cut off frequency in the Rayleigh wave, a finite element method (FEM) is used. Based on different hypotheses of the source current density, three formulations are realized with the simulation software COMSOL. Ignoring the skin and proximity effects will yield enormous errors. The results obtained with the complete formulation are relatively accurate. A two dimensions (2D) EMAT transmitting model is built upon the complete formulation. On the basis of the 2D model, the lift off effect on the feature cut off frequency is investigated in detail.","PeriodicalId":430829,"journal":{"name":"Proceedings of the 16th International Conference on Mechatronics - Mechatronika 2014","volume":"395 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123366159","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 : 2014-12-01DOI: 10.1109/MECHATRONIKA.2014.7018244
A. Zabasta, Kaspars Kondratijevs, N. Kunicina, L. Ribickis
Over the last decades, WSN systems enabled quality monitoring of power, heat production and water supply process. Empirical and practical evidence shows that the development of new services, which require new business models, is necessary. To address this issue, a framework for evaluating service prototypes and associated business models is proposed. A pilot conducted by Riga Technical University and VATS Ltd, Power distribution infrastructure services provider, enables a real life experience, how to transfer legacy power grid into a “state of art” grid by using WSN and creating a framework for new services. During the next three years, the framework will be tested by evaluating a new smart services concept and WSN approach development. The case study is done in a liberalized power supply market conditions.
{"title":"Wireless sensor networks and SOA development for optimal control of legacy power grid","authors":"A. Zabasta, Kaspars Kondratijevs, N. Kunicina, L. Ribickis","doi":"10.1109/MECHATRONIKA.2014.7018244","DOIUrl":"https://doi.org/10.1109/MECHATRONIKA.2014.7018244","url":null,"abstract":"Over the last decades, WSN systems enabled quality monitoring of power, heat production and water supply process. Empirical and practical evidence shows that the development of new services, which require new business models, is necessary. To address this issue, a framework for evaluating service prototypes and associated business models is proposed. A pilot conducted by Riga Technical University and VATS Ltd, Power distribution infrastructure services provider, enables a real life experience, how to transfer legacy power grid into a “state of art” grid by using WSN and creating a framework for new services. During the next three years, the framework will be tested by evaluating a new smart services concept and WSN approach development. The case study is done in a liberalized power supply market conditions.","PeriodicalId":430829,"journal":{"name":"Proceedings of the 16th International Conference on Mechatronics - Mechatronika 2014","volume":"72 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115445910","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 : 2014-12-01DOI: 10.1109/MECHATRONIKA.2014.7018264
D. Kraus, J. Němeček
The project is focused on the development of both simulated and real UAV platform for testing of flight control algorithms. The aim of this paper was to develop a platform that allows initial design of controllers using non-linear and linearized model of UAV in Matlab/Simulink environment. Once the controllers are designed, tuned and verified in simulation, it can then be loaded into low cost UAV platform using automated code generation. The approach was verified on real plane in real environment.
{"title":"Low cost fixed wing UAV for development of control laws","authors":"D. Kraus, J. Němeček","doi":"10.1109/MECHATRONIKA.2014.7018264","DOIUrl":"https://doi.org/10.1109/MECHATRONIKA.2014.7018264","url":null,"abstract":"The project is focused on the development of both simulated and real UAV platform for testing of flight control algorithms. The aim of this paper was to develop a platform that allows initial design of controllers using non-linear and linearized model of UAV in Matlab/Simulink environment. Once the controllers are designed, tuned and verified in simulation, it can then be loaded into low cost UAV platform using automated code generation. The approach was verified on real plane in real environment.","PeriodicalId":430829,"journal":{"name":"Proceedings of the 16th International Conference on Mechatronics - Mechatronika 2014","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114367280","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：