Pub Date : 2021-03-10DOI: 10.1109/ICIT46573.2021.9453506
E. Shehata, Jean Thomas
In this paper, a simple model predictive controller with constant switching frequency is designed to determine switching states of machine and grid NPCs. The proposed controller is designed based on modulated model predictive control principle to reduce computational burden of the algorithm. Time delay and weight factors in cost functions of the conventional model predictive control are eliminated to simplify the controller design. Also, space vector modulation algorithm is introduced to fix switching frequency of the converter. Machine side NPC is controlled to regulate the electromagnetic torque, stator flux and capacitors voltage of NPC while grid side NPC is controlled to regulate the active power, reactive power injected to the grid and DC-link voltage. The performance of the proposed controller is evaluated using 3MW/3kV generation system model. Simulation results of the proposed algorithm are good in spite of using low switching frequency.
{"title":"Simple Model Predictive Control of High Power Direct-Driven PMSG Wind Energy Systems","authors":"E. Shehata, Jean Thomas","doi":"10.1109/ICIT46573.2021.9453506","DOIUrl":"https://doi.org/10.1109/ICIT46573.2021.9453506","url":null,"abstract":"In this paper, a simple model predictive controller with constant switching frequency is designed to determine switching states of machine and grid NPCs. The proposed controller is designed based on modulated model predictive control principle to reduce computational burden of the algorithm. Time delay and weight factors in cost functions of the conventional model predictive control are eliminated to simplify the controller design. Also, space vector modulation algorithm is introduced to fix switching frequency of the converter. Machine side NPC is controlled to regulate the electromagnetic torque, stator flux and capacitors voltage of NPC while grid side NPC is controlled to regulate the active power, reactive power injected to the grid and DC-link voltage. The performance of the proposed controller is evaluated using 3MW/3kV generation system model. Simulation results of the proposed algorithm are good in spite of using low switching frequency.","PeriodicalId":193338,"journal":{"name":"2021 22nd IEEE International Conference on Industrial Technology (ICIT)","volume":"52 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114972867","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 : 2021-03-10DOI: 10.1109/ICIT46573.2021.9453553
William Tarneberg, P. Skarin, C. Gehrmann, M. Kihl
Digital twins are poised to play a vital role in the industry 4.0 era. A cloud-based digital twin can augment the entity that it represents. To that effect, we envision that digital twins can have embedded control systems when paired with a cyber physical system, yielding significant performance and configurability advantages. However, relegating controllers to a cloud-based digital twin exposes them to a new set of attack surfaces. Given the intricacy of such systems and the plethora of mitigating actions they can take, intrusion detection is integral to maintaining the integrity of such system. In this paper, we propose and prototype a cloud-native digital twin proof of concept for evaluating the viability of the concept. The resulting platform is evaluated for its ability to host a cyber-physical system and its potential to incorporate an intrusion detection system.
{"title":"Prototyping intrusion detection in an industrial cloud-native digital twin","authors":"William Tarneberg, P. Skarin, C. Gehrmann, M. Kihl","doi":"10.1109/ICIT46573.2021.9453553","DOIUrl":"https://doi.org/10.1109/ICIT46573.2021.9453553","url":null,"abstract":"Digital twins are poised to play a vital role in the industry 4.0 era. A cloud-based digital twin can augment the entity that it represents. To that effect, we envision that digital twins can have embedded control systems when paired with a cyber physical system, yielding significant performance and configurability advantages. However, relegating controllers to a cloud-based digital twin exposes them to a new set of attack surfaces. Given the intricacy of such systems and the plethora of mitigating actions they can take, intrusion detection is integral to maintaining the integrity of such system. In this paper, we propose and prototype a cloud-native digital twin proof of concept for evaluating the viability of the concept. The resulting platform is evaluated for its ability to host a cyber-physical system and its potential to incorporate an intrusion detection system.","PeriodicalId":193338,"journal":{"name":"2021 22nd IEEE International Conference on Industrial Technology (ICIT)","volume":"92 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114975558","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 : 2021-03-10DOI: 10.1109/ICIT46573.2021.9453505
M. Dlapa
The application of the Robust Control Design Toolbox for General Time Delay Systems via Structured Singular Value: Unstable Systems for the Matlab system to the unstable plant with time delay in numerator and denominator is described in this paper. The uncertain time delays are treated using multiplicative and quotient uncertainty. The algebraic approach part implements evolutionary algorithm Differential Migration and pole placement for general 3rd order system with evaluation via structured singular value. Both, D-K iteration and algebraic approach, implements two-degree-of-freedom feedback loop controller with factoriz ation fixing internal instability. Both procedures are compared in simulations for maximum and half time delay and simple and two-degree-of-freedom feedback loop.
{"title":"Robust Control Design Toolbox for General Time Delay Systems via Structured Singular Value: Unstable Systems with Factorization for Two-Degree-of-Freedom Controller","authors":"M. Dlapa","doi":"10.1109/ICIT46573.2021.9453505","DOIUrl":"https://doi.org/10.1109/ICIT46573.2021.9453505","url":null,"abstract":"The application of the Robust Control Design Toolbox for General Time Delay Systems via Structured Singular Value: Unstable Systems for the Matlab system to the unstable plant with time delay in numerator and denominator is described in this paper. The uncertain time delays are treated using multiplicative and quotient uncertainty. The algebraic approach part implements evolutionary algorithm Differential Migration and pole placement for general 3rd order system with evaluation via structured singular value. Both, D-K iteration and algebraic approach, implements two-degree-of-freedom feedback loop controller with factoriz ation fixing internal instability. Both procedures are compared in simulations for maximum and half time delay and simple and two-degree-of-freedom feedback loop.","PeriodicalId":193338,"journal":{"name":"2021 22nd IEEE International Conference on Industrial Technology (ICIT)","volume":"118 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127324571","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 : 2021-03-10DOI: 10.1109/ICIT46573.2021.9453602
Davinson Castano Cano, M. Grossard, A. Hubert
This paper presents the design and characterization of a new multi-axis force/torque sensor based on resonant technology. This sensor is capable of simultaneously estimating the three force components as well as the three torque components. It is designed for use in collaborative robotics applications and can be integrated into handles or grippers of robotic manipulators to estimate interactions between robots and humans. Compared to the technologies currently in use and based on strain gauges, this system offers many advantages, particularly in terms of both safety and redundancy. This paper describes the design of this sensor and then compares the prototype to a state-of-the-art commercial sensor. Comparisons show that the proposed technology is at least as efficient as the industrial system, although its dimensions remain slightly larger.
{"title":"Design and Validation of a Resonant Multi-Axis Force Sensor for Collaborative Robotics","authors":"Davinson Castano Cano, M. Grossard, A. Hubert","doi":"10.1109/ICIT46573.2021.9453602","DOIUrl":"https://doi.org/10.1109/ICIT46573.2021.9453602","url":null,"abstract":"This paper presents the design and characterization of a new multi-axis force/torque sensor based on resonant technology. This sensor is capable of simultaneously estimating the three force components as well as the three torque components. It is designed for use in collaborative robotics applications and can be integrated into handles or grippers of robotic manipulators to estimate interactions between robots and humans. Compared to the technologies currently in use and based on strain gauges, this system offers many advantages, particularly in terms of both safety and redundancy. This paper describes the design of this sensor and then compares the prototype to a state-of-the-art commercial sensor. Comparisons show that the proposed technology is at least as efficient as the industrial system, although its dimensions remain slightly larger.","PeriodicalId":193338,"journal":{"name":"2021 22nd IEEE International Conference on Industrial Technology (ICIT)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127325737","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 : 2021-03-10DOI: 10.1109/ICIT46573.2021.9453680
Alessio Bucaioni, Vlatko Dimic, Mattias Gålnander, Henrik Lönn, John Lundbäck
This paper reports on our experience in transferring an academic model-based methodology for the development of automotive software systems into an industrial integrated development environment. The transferred methodology makes use of two industrial modelling languages and provides for the development and architectural exploration of automotive system and software designs with temporal awareness. We demonstrate the usage of the transferred methodology using the brake-by-wire automotive functionality. Eventually, we describe the challenges we have faced and the lessons we have learned in performing this technology transfer.
{"title":"Transferring a model-based development methodology to the automotive industry","authors":"Alessio Bucaioni, Vlatko Dimic, Mattias Gålnander, Henrik Lönn, John Lundbäck","doi":"10.1109/ICIT46573.2021.9453680","DOIUrl":"https://doi.org/10.1109/ICIT46573.2021.9453680","url":null,"abstract":"This paper reports on our experience in transferring an academic model-based methodology for the development of automotive software systems into an industrial integrated development environment. The transferred methodology makes use of two industrial modelling languages and provides for the development and architectural exploration of automotive system and software designs with temporal awareness. We demonstrate the usage of the transferred methodology using the brake-by-wire automotive functionality. Eventually, we describe the challenges we have faced and the lessons we have learned in performing this technology transfer.","PeriodicalId":193338,"journal":{"name":"2021 22nd IEEE International Conference on Industrial Technology (ICIT)","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123285379","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 : 2021-03-10DOI: 10.1109/ICIT46573.2021.9453511
P. Leitão, T. Strasser, S. Karnouskos, L. Ribeiro, J. Barbosa, V. Huang
Cyber-Physical Systems (CPS) is a key concept in Industry 4.0, acting as a backbone to develop smart processes, machines and products. Multi-Agent Systems (MAS) is a suitable paradigm for the realization of such industrial CPS systems, supporting the distribution of intelligence and decision-making capabilities among a network of autonomous and cooperative agents. Standardization is a key factor for the acceptance of industrial CPS and agent-based systems, assuming a critical role in establishing specifications for the hardware integration, which is an important requirement for industrial agents. This paper focuses on the recently established IEEE 2660.1-2020 standard that defines a recommended practice to solve the interface problem when applying industrial agents, namely integrating intelligent software agents with low-level automation devices in the CPS context. The paper illustrates the applicability of the standard in three different application scenarios related to power and energy systems, factory automation and building automation, and discusses future directions in terms of standardization in the field of industrial agents, that are required for its wider adoption in the realization of industrial CPS solutions.
{"title":"Recommendation of Best Practices for Industrial Agent Systems based on the IEEE 2660.1 Standard","authors":"P. Leitão, T. Strasser, S. Karnouskos, L. Ribeiro, J. Barbosa, V. Huang","doi":"10.1109/ICIT46573.2021.9453511","DOIUrl":"https://doi.org/10.1109/ICIT46573.2021.9453511","url":null,"abstract":"Cyber-Physical Systems (CPS) is a key concept in Industry 4.0, acting as a backbone to develop smart processes, machines and products. Multi-Agent Systems (MAS) is a suitable paradigm for the realization of such industrial CPS systems, supporting the distribution of intelligence and decision-making capabilities among a network of autonomous and cooperative agents. Standardization is a key factor for the acceptance of industrial CPS and agent-based systems, assuming a critical role in establishing specifications for the hardware integration, which is an important requirement for industrial agents. This paper focuses on the recently established IEEE 2660.1-2020 standard that defines a recommended practice to solve the interface problem when applying industrial agents, namely integrating intelligent software agents with low-level automation devices in the CPS context. The paper illustrates the applicability of the standard in three different application scenarios related to power and energy systems, factory automation and building automation, and discusses future directions in terms of standardization in the field of industrial agents, that are required for its wider adoption in the realization of industrial CPS solutions.","PeriodicalId":193338,"journal":{"name":"2021 22nd IEEE International Conference on Industrial Technology (ICIT)","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123437720","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 : 2021-03-10DOI: 10.1109/ICIT46573.2021.9453496
Haris Isakovic, S. Dangl, Zlatan Tucakovic, R. Grosu
The rapid increase in number of devices in Internet-of-Things generates astronomic amounts of data. Dealing with noisy and low quality data uses more effort than the data analysis itself. Dealing with noisy data at the source would significantly reduce the effort of pre-processing during analysis, as well as the storage and bandwidth overhead. In this paper we introduce an Adaptive Signal Processing Platform (ASPF) for CPS/IoT Ecosystems. It provides ability to dynamically detect noise variation in a signal and successfully filter these components out of the signal leaving only clean and useful data. The paper shows two approaches with different requirements on effort and scalability.
{"title":"Adaptive Signal Filtering Platform for a CPS/IoT Ecosystem","authors":"Haris Isakovic, S. Dangl, Zlatan Tucakovic, R. Grosu","doi":"10.1109/ICIT46573.2021.9453496","DOIUrl":"https://doi.org/10.1109/ICIT46573.2021.9453496","url":null,"abstract":"The rapid increase in number of devices in Internet-of-Things generates astronomic amounts of data. Dealing with noisy and low quality data uses more effort than the data analysis itself. Dealing with noisy data at the source would significantly reduce the effort of pre-processing during analysis, as well as the storage and bandwidth overhead. In this paper we introduce an Adaptive Signal Processing Platform (ASPF) for CPS/IoT Ecosystems. It provides ability to dynamically detect noise variation in a signal and successfully filter these components out of the signal leaving only clean and useful data. The paper shows two approaches with different requirements on effort and scalability.","PeriodicalId":193338,"journal":{"name":"2021 22nd IEEE International Conference on Industrial Technology (ICIT)","volume":"45 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123584838","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 : 2021-03-10DOI: 10.1109/ICIT46573.2021.9453529
Felix Gehlhoff, Lukas Wiegandt, A. Fay
The increasing dynamics of manufacturing systems promote the utilization of decentral system architectures, such as Multi-agent Systems (MAS). These are especially applicable for dynamic systems that exhibit structural and behavioural changes during runtime. This paper develops a MAS that is capable of decentralised process planning that does not require any a priori definition of compatibility or interfaces between machines. Furthermore, the paper outlines how the producibility graph that is derived by the agents during process planning is updated and shared between the agents to keep the knowledge bases of the agents updated at all times.
{"title":"Agent-Based Decentralised Process Planning and Evolutionary Change Propagation","authors":"Felix Gehlhoff, Lukas Wiegandt, A. Fay","doi":"10.1109/ICIT46573.2021.9453529","DOIUrl":"https://doi.org/10.1109/ICIT46573.2021.9453529","url":null,"abstract":"The increasing dynamics of manufacturing systems promote the utilization of decentral system architectures, such as Multi-agent Systems (MAS). These are especially applicable for dynamic systems that exhibit structural and behavioural changes during runtime. This paper develops a MAS that is capable of decentralised process planning that does not require any a priori definition of compatibility or interfaces between machines. Furthermore, the paper outlines how the producibility graph that is derived by the agents during process planning is updated and shared between the agents to keep the knowledge bases of the agents updated at all times.","PeriodicalId":193338,"journal":{"name":"2021 22nd IEEE International Conference on Industrial Technology (ICIT)","volume":"65 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122457681","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 : 2021-03-10DOI: 10.1109/ICIT46573.2021.9453554
Riccardo Mandrioli, M. Ricco, M. Hammami, A. Viatkin, G. Grandi
In this paper, a ripple-free output current interleaved DC/DC converter has been analyzed for Electric vehicle charging stations. Firstly, a ripple-free control strategy able to ensure a theoretically flat output current profile and input voltage ripple minimization at any working conditions is discussed. This strategy drives the active front-end to regulate the DC-link voltage and, at the same time, the interleaved back-end converter to operate in zero ripple working points. Secondarily, a generalized designing algorithm able to consider constraints like AC grid voltage and battery voltage is proposed. Finally, simulations support ripple mitigation capabilities in steady-state and transient conditions for a 12-leg scheme.
{"title":"A Ripple-Free Output Current Interleaved DC/DC Converter Design Algorithm for EV Charging","authors":"Riccardo Mandrioli, M. Ricco, M. Hammami, A. Viatkin, G. Grandi","doi":"10.1109/ICIT46573.2021.9453554","DOIUrl":"https://doi.org/10.1109/ICIT46573.2021.9453554","url":null,"abstract":"In this paper, a ripple-free output current interleaved DC/DC converter has been analyzed for Electric vehicle charging stations. Firstly, a ripple-free control strategy able to ensure a theoretically flat output current profile and input voltage ripple minimization at any working conditions is discussed. This strategy drives the active front-end to regulate the DC-link voltage and, at the same time, the interleaved back-end converter to operate in zero ripple working points. Secondarily, a generalized designing algorithm able to consider constraints like AC grid voltage and battery voltage is proposed. Finally, simulations support ripple mitigation capabilities in steady-state and transient conditions for a 12-leg scheme.","PeriodicalId":193338,"journal":{"name":"2021 22nd IEEE International Conference on Industrial Technology (ICIT)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129337711","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 : 2021-03-10DOI: 10.1109/ICIT46573.2021.9453688
Jaeho Ryu, I. Hahn
In general, magnetic excitation of eddy current density is calculated in a 3-dimensional system to gain the most accurate results leading to long computational times. However, the long computational time might be problematic due to needs for high computational effort. In order to improve this disadvantageous point, this paper deals with a finite-difference approximation considering the curl and divergence operator of eddy current density. In particular, by using this numerical modeling calculation, the proposed method in this paper can quickly implement the eddy current calculation in the 3-dimensional system and build the eddy currents modeling of a specific part of interest. Lastly, the comparative analysis with a commercial tool for 3-D FEM is carried out, and the accuracy of the 3 dimensional finite difference method (3-D FDM) is verified.
一般来说，为了获得最精确的结果，在三维系统中计算涡流密度的磁激励，导致计算时间长。然而，由于需要高计算量，较长的计算时间可能会成为问题。为了改善这一缺点，本文讨论了考虑涡流密度旋度和散度算子的有限差分近似。特别是，通过这种数值模拟计算，本文提出的方法可以快速实现三维系统中的涡流计算，并建立感兴趣的特定部分的涡流模型。最后，与商用三维有限元分析工具进行了对比分析，验证了三维有限差分法(3- d FDM)的精度。
{"title":"Numerical modeling for 3D eddy current calculation in magneto-quasistatic approximation","authors":"Jaeho Ryu, I. Hahn","doi":"10.1109/ICIT46573.2021.9453688","DOIUrl":"https://doi.org/10.1109/ICIT46573.2021.9453688","url":null,"abstract":"In general, magnetic excitation of eddy current density is calculated in a 3-dimensional system to gain the most accurate results leading to long computational times. However, the long computational time might be problematic due to needs for high computational effort. In order to improve this disadvantageous point, this paper deals with a finite-difference approximation considering the curl and divergence operator of eddy current density. In particular, by using this numerical modeling calculation, the proposed method in this paper can quickly implement the eddy current calculation in the 3-dimensional system and build the eddy currents modeling of a specific part of interest. Lastly, the comparative analysis with a commercial tool for 3-D FEM is carried out, and the accuracy of the 3 dimensional finite difference method (3-D FDM) is verified.","PeriodicalId":193338,"journal":{"name":"2021 22nd IEEE International Conference on Industrial Technology (ICIT)","volume":"83 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114624830","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：