Pub Date : 2017-06-06DOI: 10.1109/GIOTS.2017.8016223
L. S. Vestergaard, João Fernandes, M. Presser
In this paper, we investigate how far IoT usability has come, and present a field trial on how Creative Coders — digital artists who are self-taught programmers — interact with the world of IoT through a simplified HTTP oriented publish/subscribe service. When elaborating our findings, we discuss the implications of reducing technological complexity in production oriented ecosystems like IoT platforms.
{"title":"Creative coding within the Internet of Things","authors":"L. S. Vestergaard, João Fernandes, M. Presser","doi":"10.1109/GIOTS.2017.8016223","DOIUrl":"https://doi.org/10.1109/GIOTS.2017.8016223","url":null,"abstract":"In this paper, we investigate how far IoT usability has come, and present a field trial on how Creative Coders — digital artists who are self-taught programmers — interact with the world of IoT through a simplified HTTP oriented publish/subscribe service. When elaborating our findings, we discuss the implications of reducing technological complexity in production oriented ecosystems like IoT platforms.","PeriodicalId":413939,"journal":{"name":"2017 Global Internet of Things Summit (GIoTS)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129333094","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 : 2017-06-01DOI: 10.1109/GIOTS.2017.8016219
G. Serugendo, N. Abdennadher, Houssem Ben Mahfoudh, F. D. Angelis, Roberto Tomaylla
Ubiquitous and context-aware sensors are increasing in number and aim at providing comfort and better life quality. They are spatially distributed and their computation capacity are still under-exploited. This article discusses spatial edge services, a new generation of services exploiting IoT and spatially distributed data. They result from collective and decentralized interactions of multiple computing entities. They rely on a logic and chemical-based coordination model. In this paper, we discuss several spatial edge services cases and present an actual deployment and a prototype example. We discuss evaluation results, in particular scalability and accuracy. Spatial edge services provide innovation capabilities for the software industry, connected objects manufacturers and edge computing industry. Future work tackles on-the-fly service composition with requested quality of service (QoS).
{"title":"Spatial edge services","authors":"G. Serugendo, N. Abdennadher, Houssem Ben Mahfoudh, F. D. Angelis, Roberto Tomaylla","doi":"10.1109/GIOTS.2017.8016219","DOIUrl":"https://doi.org/10.1109/GIOTS.2017.8016219","url":null,"abstract":"Ubiquitous and context-aware sensors are increasing in number and aim at providing comfort and better life quality. They are spatially distributed and their computation capacity are still under-exploited. This article discusses spatial edge services, a new generation of services exploiting IoT and spatially distributed data. They result from collective and decentralized interactions of multiple computing entities. They rely on a logic and chemical-based coordination model. In this paper, we discuss several spatial edge services cases and present an actual deployment and a prototype example. We discuss evaluation results, in particular scalability and accuracy. Spatial edge services provide innovation capabilities for the software industry, connected objects manufacturers and edge computing industry. Future work tackles on-the-fly service composition with requested quality of service (QoS).","PeriodicalId":413939,"journal":{"name":"2017 Global Internet of Things Summit (GIoTS)","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126847755","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 : 2017-06-01DOI: 10.1109/GIOTS.2017.8016216
Johannes Innerbichler, Suat Gönül, Violeta Damjanovic-Behrendt, B. Mandler, F. Strohmeier
This paper presents our architectural approach to building a collaborative Industry 4.0 platform that enables IoT-based real-time monitoring, optimization and negotiation in manufacturing supply chains. The platform is called NIMBLE and is currently being developed in a European research project. The presented approach utilizes microservice technology, and implements the core business functionality of the platform through a composition of decentralized, scalable services. The communication among services, and with platform users, manufacturers, suppliers, sensors and Web resources, is supported through simple protocols and lightweight mechanisms. Core business services of the implemented architecture are released as open source software, enabling multiple prospective platform-providers to establish B2B marketplaces for collaboration within their own industrial sector or region. To demonstrate microservices in practice, we present two scenarios, both related to manufacturing of wooden home buildings: one is IoT-based data sharing in a supply chain, and the other deals with product driven logistics planning. The further development of the platform will be driven by the requirements of at least four different use cases throughout Europe, and by incorporating advanced business models to support the growth of powerful network effects of the platform.
{"title":"NIMBLE collaborative platform: Microservice architectural approach to federated IoT","authors":"Johannes Innerbichler, Suat Gönül, Violeta Damjanovic-Behrendt, B. Mandler, F. Strohmeier","doi":"10.1109/GIOTS.2017.8016216","DOIUrl":"https://doi.org/10.1109/GIOTS.2017.8016216","url":null,"abstract":"This paper presents our architectural approach to building a collaborative Industry 4.0 platform that enables IoT-based real-time monitoring, optimization and negotiation in manufacturing supply chains. The platform is called NIMBLE and is currently being developed in a European research project. The presented approach utilizes microservice technology, and implements the core business functionality of the platform through a composition of decentralized, scalable services. The communication among services, and with platform users, manufacturers, suppliers, sensors and Web resources, is supported through simple protocols and lightweight mechanisms. Core business services of the implemented architecture are released as open source software, enabling multiple prospective platform-providers to establish B2B marketplaces for collaboration within their own industrial sector or region. To demonstrate microservices in practice, we present two scenarios, both related to manufacturing of wooden home buildings: one is IoT-based data sharing in a supply chain, and the other deals with product driven logistics planning. The further development of the platform will be driven by the requirements of at least four different use cases throughout Europe, and by incorporating advanced business models to support the growth of powerful network effects of the platform.","PeriodicalId":413939,"journal":{"name":"2017 Global Internet of Things Summit (GIoTS)","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116524370","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 : 2017-06-01DOI: 10.1109/GIOTS.2017.8016265
Stefan Forsström, Ulf Jennehag
The expected monetary costs and response time performance is important information to know before deploying an industrial Internet-of-Things system. The system investigated in this paper is built up by combining the Open Plant Communication Universal Architecture and the Microsoft Azure Internet-of-Things Hub. We consider a real life industrial scenario that remotely monitors a piece of industrial equipment consisting of 1500 sensors, of which 600 update their values every second. The measured results show that the response times for a fiber based Internet connection was on average 770 ms with a standard deviation of 330 ms and the same measurements on a mobile internet connection was on average 1150 ms with a standard deviation of 340 ms. Cost wise, the investigated scenario fits within the most expensive price plan for the IoT hub and ends in a total of just over $5000 per month for the whole cloud service.
{"title":"A performance and cost evaluation of combining OPC-UA and Microsoft Azure IoT Hub into an industrial Internet-of-Things system","authors":"Stefan Forsström, Ulf Jennehag","doi":"10.1109/GIOTS.2017.8016265","DOIUrl":"https://doi.org/10.1109/GIOTS.2017.8016265","url":null,"abstract":"The expected monetary costs and response time performance is important information to know before deploying an industrial Internet-of-Things system. The system investigated in this paper is built up by combining the Open Plant Communication Universal Architecture and the Microsoft Azure Internet-of-Things Hub. We consider a real life industrial scenario that remotely monitors a piece of industrial equipment consisting of 1500 sensors, of which 600 update their values every second. The measured results show that the response times for a fiber based Internet connection was on average 770 ms with a standard deviation of 330 ms and the same measurements on a mobile internet connection was on average 1150 ms with a standard deviation of 340 ms. Cost wise, the investigated scenario fits within the most expensive price plan for the IoT hub and ends in a total of just over $5000 per month for the whole cloud service.","PeriodicalId":413939,"journal":{"name":"2017 Global Internet of Things Summit (GIoTS)","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126486456","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 : 2017-06-01DOI: 10.1109/GIOTS.2017.8016249
A. Gerka, M. Eichelberg, Finn Bayer, M. Frenken, A. Hein
Dementia patients, like most older adults, prefer to live in their own home as long as possible. This requires, however, that they are able to perform activities of daily living (ADL). Therefore, many research projects install different sensor setups to identify ADLs. Though the water usage correlates with many ADLs (i.e.: bathing, cooking) only few of these systems use water usage sensors. The reason is that there is no water usage sensor available that is unobtrusive, ambient and precise. In this article, we propose a water usage sensor that is based on a piezoelectric element that fulfills these requirements. We describe the implementation of the sensor system in a living lab. Additionally, we discuss different features that were extracted from the sensor signal and different machine learning algorithms that were used to classify the data. Finally, we present the results to several tests we performed to determine the accuracy of our sensor system under different environmental conditions.
{"title":"Ambient water usage sensor for the identification of daily activities","authors":"A. Gerka, M. Eichelberg, Finn Bayer, M. Frenken, A. Hein","doi":"10.1109/GIOTS.2017.8016249","DOIUrl":"https://doi.org/10.1109/GIOTS.2017.8016249","url":null,"abstract":"Dementia patients, like most older adults, prefer to live in their own home as long as possible. This requires, however, that they are able to perform activities of daily living (ADL). Therefore, many research projects install different sensor setups to identify ADLs. Though the water usage correlates with many ADLs (i.e.: bathing, cooking) only few of these systems use water usage sensors. The reason is that there is no water usage sensor available that is unobtrusive, ambient and precise. In this article, we propose a water usage sensor that is based on a piezoelectric element that fulfills these requirements. We describe the implementation of the sensor system in a living lab. Additionally, we discuss different features that were extracted from the sensor signal and different machine learning algorithms that were used to classify the data. Finally, we present the results to several tests we performed to determine the accuracy of our sensor system under different environmental conditions.","PeriodicalId":413939,"journal":{"name":"2017 Global Internet of Things Summit (GIoTS)","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123520400","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 : 2017-06-01DOI: 10.1109/GIOTS.2017.8016278
A. E. Hajjar, George Roussos, Maura B. Paterson
In this paper, we propose a modification of the RPL routing protocol by introducing the SISLOF Objective Function ensuring that only motes that share a suitable key can join the RPL routing table. This will ensure that all IoT network motes connect in a secure method. SISLOF uses the concept of key pre-distribution proposed by Eschenauer and Gligor in the context of the Internet of Things. First, we discuss related work that provide evidence that the key pre-distribution scheme in the context of the IoT with default RPL metrics fails to achieve the full network connectivity using the same ring size, however full time connectivity can be achieved but with a great cost in term of the large rings sizes. We introduce the SISLOF Objective Function and explain the modification it does to the RPL messages (DIO and DAO). We finally show the performance of the key pre-distribution in the context of the Internet of Things when SISLOF is used as the Objective Function of the RPL routing protocol.
{"title":"Secure routing in IoT networks with SISLOF","authors":"A. E. Hajjar, George Roussos, Maura B. Paterson","doi":"10.1109/GIOTS.2017.8016278","DOIUrl":"https://doi.org/10.1109/GIOTS.2017.8016278","url":null,"abstract":"In this paper, we propose a modification of the RPL routing protocol by introducing the SISLOF Objective Function ensuring that only motes that share a suitable key can join the RPL routing table. This will ensure that all IoT network motes connect in a secure method. SISLOF uses the concept of key pre-distribution proposed by Eschenauer and Gligor in the context of the Internet of Things. First, we discuss related work that provide evidence that the key pre-distribution scheme in the context of the IoT with default RPL metrics fails to achieve the full network connectivity using the same ring size, however full time connectivity can be achieved but with a great cost in term of the large rings sizes. We introduce the SISLOF Objective Function and explain the modification it does to the RPL messages (DIO and DAO). We finally show the performance of the key pre-distribution in the context of the Internet of Things when SISLOF is used as the Objective Function of the RPL routing protocol.","PeriodicalId":413939,"journal":{"name":"2017 Global Internet of Things Summit (GIoTS)","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124077629","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 : 2017-06-01DOI: 10.1109/GIOTS.2017.8016244
J. Knapp, P. Flikkema
IoT devices will increasingly be placed in remote or inaccessible locations for long-term deployments. At the same time, power and energy-reserve demands will be heterogeneous and scale proportionately with capability and functionality. Moreover, demand for sophisticated behavior will increase, placing stringent requirements on their energy subsystems. Thus there is a need for an energy subsystem that can be integrated with IoT nodes to provide energy-neutral operation. We describe an architecture, design, and implementation of an energy-neutral battery-backed solar energy system for IoT devices. An emphasis is placed on capacity planning, enabling real-time analytics and control, and packaging for thermal management in extreme environments. We present test results on a prototype implementation that is now in production for use with sensor-actuator nodes in environmental and ecological monitoring and control applications.
{"title":"Design and implementation of an energy-neutral solar energy system for wireless sensor-actuator nodes","authors":"J. Knapp, P. Flikkema","doi":"10.1109/GIOTS.2017.8016244","DOIUrl":"https://doi.org/10.1109/GIOTS.2017.8016244","url":null,"abstract":"IoT devices will increasingly be placed in remote or inaccessible locations for long-term deployments. At the same time, power and energy-reserve demands will be heterogeneous and scale proportionately with capability and functionality. Moreover, demand for sophisticated behavior will increase, placing stringent requirements on their energy subsystems. Thus there is a need for an energy subsystem that can be integrated with IoT nodes to provide energy-neutral operation. We describe an architecture, design, and implementation of an energy-neutral battery-backed solar energy system for IoT devices. An emphasis is placed on capacity planning, enabling real-time analytics and control, and packaging for thermal management in extreme environments. We present test results on a prototype implementation that is now in production for use with sensor-actuator nodes in environmental and ecological monitoring and control applications.","PeriodicalId":413939,"journal":{"name":"2017 Global Internet of Things Summit (GIoTS)","volume":"81 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129194039","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 : 2017-06-01DOI: 10.1109/GIOTS.2017.8016242
Biruk B. Seyoum, M. Rossi, D. Brunelli
In this paper, we present the design of a smart bolt for high-end electro-mechanical systems. The bolt is equipped with temperature sensor, an RF chip and it is powered by a Thermoelectric generator (TEG). The work includes the design choices on the small size TEG, and characterizations of the TEGs and DC-DC converters suitable for ensuring reliability and energy neutral conditions. The characterization was done to determine the amount of power that can be generated from a TEG under different loads and at temperature gradients typical of mechanical environments. Performance demonstrate that the power generated at different temperature gradients extracted by means of a boost converter, is sufficient to guarantee continuous wireless monitoring service for high value critical fastener such as avionic, motorsport, and aerospace.
{"title":"A self-powered wireless bolt for smart critical fastener","authors":"Biruk B. Seyoum, M. Rossi, D. Brunelli","doi":"10.1109/GIOTS.2017.8016242","DOIUrl":"https://doi.org/10.1109/GIOTS.2017.8016242","url":null,"abstract":"In this paper, we present the design of a smart bolt for high-end electro-mechanical systems. The bolt is equipped with temperature sensor, an RF chip and it is powered by a Thermoelectric generator (TEG). The work includes the design choices on the small size TEG, and characterizations of the TEGs and DC-DC converters suitable for ensuring reliability and energy neutral conditions. The characterization was done to determine the amount of power that can be generated from a TEG under different loads and at temperature gradients typical of mechanical environments. Performance demonstrate that the power generated at different temperature gradients extracted by means of a boost converter, is sufficient to guarantee continuous wireless monitoring service for high value critical fastener such as avionic, motorsport, and aerospace.","PeriodicalId":413939,"journal":{"name":"2017 Global Internet of Things Summit (GIoTS)","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123033301","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 : 2017-06-01DOI: 10.1109/GIOTS.2017.8016234
Veronika Domova, A. Dagnino
In recent years, IIoT continues to gain traction introducing promising opportunities to build powerful systems and applications with new benefits to industry. However, as the industrial systems become more complex, the number of alarm calls in plants has exploded to a very large number. Having too many alarms to handle hinders operators from taking the right decisions at the right time which potentially can lead to safety, reliability, privacy, and security issues. The work presented in this paper is aimed at improving the safety of industrial operations by better managing alarms and also increasing the reliability of the industrial operation by ensuring the processes are reliable. A main outcome of the project is a set of alarm data mining algorithms and a high-fidelity prototype of a user interface for reviewing and analyzing the mined alarm data.
{"title":"Towards intelligent alarm management in the Age of IIoT","authors":"Veronika Domova, A. Dagnino","doi":"10.1109/GIOTS.2017.8016234","DOIUrl":"https://doi.org/10.1109/GIOTS.2017.8016234","url":null,"abstract":"In recent years, IIoT continues to gain traction introducing promising opportunities to build powerful systems and applications with new benefits to industry. However, as the industrial systems become more complex, the number of alarm calls in plants has exploded to a very large number. Having too many alarms to handle hinders operators from taking the right decisions at the right time which potentially can lead to safety, reliability, privacy, and security issues. The work presented in this paper is aimed at improving the safety of industrial operations by better managing alarms and also increasing the reliability of the industrial operation by ensuring the processes are reliable. A main outcome of the project is a set of alarm data mining algorithms and a high-fidelity prototype of a user interface for reviewing and analyzing the mined alarm data.","PeriodicalId":413939,"journal":{"name":"2017 Global Internet of Things Summit (GIoTS)","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121731486","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 : 2017-06-01DOI: 10.1109/GIOTS.2017.8016241
C. Pérez-Penichet, Frederik Hermans, T. Voigt
Backscatter communication reduces the energy consumption of resource-constrained sensors and actuators by several orders of magnitude as it avoids the resource-consuming need to generate a radio wave. Many backscatter systems and applications suffer from low communication range. By exploiting the collective power of several tags that transmit the same data simultaneously, constructive interference may help to remedy this problem and increase the communication range. When several tags backscatter the same signal simultaneously it is not necessarily true that constructive interference occurs. As our theoretical results and previous work indicate the interference might also be destructive. Our experimental results on real hardware suggest that exploiting constructive interference to increase the communication range requires careful coordination which is difficult in decentralized settings.
{"title":"On limits of constructive interference in backscatter systems","authors":"C. Pérez-Penichet, Frederik Hermans, T. Voigt","doi":"10.1109/GIOTS.2017.8016241","DOIUrl":"https://doi.org/10.1109/GIOTS.2017.8016241","url":null,"abstract":"Backscatter communication reduces the energy consumption of resource-constrained sensors and actuators by several orders of magnitude as it avoids the resource-consuming need to generate a radio wave. Many backscatter systems and applications suffer from low communication range. By exploiting the collective power of several tags that transmit the same data simultaneously, constructive interference may help to remedy this problem and increase the communication range. When several tags backscatter the same signal simultaneously it is not necessarily true that constructive interference occurs. As our theoretical results and previous work indicate the interference might also be destructive. Our experimental results on real hardware suggest that exploiting constructive interference to increase the communication range requires careful coordination which is difficult in decentralized settings.","PeriodicalId":413939,"journal":{"name":"2017 Global Internet of Things Summit (GIoTS)","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131192246","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：