Jeong-woo Han, Se-Young Kim, Ki-Man Kim, Won-seok Choi, Min-jae Kim, Seung-Yong Chun, Kwon Son
Spread spectrum techniques are used in communication systems to provide low probability of intercept and jamming, to overcome the channel where the transmitted signal is distorted by multipath propagation. In this paper, we consider spread spectrum modulation and demodulation techniques to overcome the inter symbol interference (ISI) by multipath propagation in underwater acoustic communication channels. We consider the quadrature phase shift keying (QPSK) direct sequence spread spectrum (DSSS). We confirm the performance of underwater acoustic communication by the simulation with underwater channel impulse response and experiment in underwater. As a result, the QPSK-DSSS technique presented low bit error rate (BER) than QPSK.
{"title":"A Study on the Underwater Acoustic Communication with Direct Sequence Spread Spectrum","authors":"Jeong-woo Han, Se-Young Kim, Ki-Man Kim, Won-seok Choi, Min-jae Kim, Seung-Yong Chun, Kwon Son","doi":"10.1109/EUC.2010.56","DOIUrl":"https://doi.org/10.1109/EUC.2010.56","url":null,"abstract":"Spread spectrum techniques are used in communication systems to provide low probability of intercept and jamming, to overcome the channel where the transmitted signal is distorted by multipath propagation. In this paper, we consider spread spectrum modulation and demodulation techniques to overcome the inter symbol interference (ISI) by multipath propagation in underwater acoustic communication channels. We consider the quadrature phase shift keying (QPSK) direct sequence spread spectrum (DSSS). We confirm the performance of underwater acoustic communication by the simulation with underwater channel impulse response and experiment in underwater. As a result, the QPSK-DSSS technique presented low bit error rate (BER) than QPSK.","PeriodicalId":265175,"journal":{"name":"2010 IEEE/IFIP International Conference on Embedded and Ubiquitous Computing","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2010-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116863883","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}
Over the recent years, one of the most important problems in wireless sensor networks (WSNs) is to develope an energy-efficient and reliable routing protocol and provide network robustness. To achieve these objectives, we propose a new architecture for data dissemination called Two Tier Cluster Based Routing Protocol (TTCRP) for reliable data delivery in WSNs. TTCRP uses resource rich cluster heads with dual channels to form the clusters for efficient data delivery. While it provides power control algorithm to connect the isolated low power sensor nodes with minimum required power that achieves the network robustness. Simulation results reveal that TTCRP is efficient and provides reliability in both uniform as well as non-uniform sensor nodes deployment.
{"title":"Two-Tier Cluster Based Routing Protocol for Wireless Sensor Networks","authors":"Asif U. Khattak, G. Shah, M. Ahsan","doi":"10.1109/EUC.2010.68","DOIUrl":"https://doi.org/10.1109/EUC.2010.68","url":null,"abstract":"Over the recent years, one of the most important problems in wireless sensor networks (WSNs) is to develope an energy-efficient and reliable routing protocol and provide network robustness. To achieve these objectives, we propose a new architecture for data dissemination called Two Tier Cluster Based Routing Protocol (TTCRP) for reliable data delivery in WSNs. TTCRP uses resource rich cluster heads with dual channels to form the clusters for efficient data delivery. While it provides power control algorithm to connect the isolated low power sensor nodes with minimum required power that achieves the network robustness. Simulation results reveal that TTCRP is efficient and provides reliability in both uniform as well as non-uniform sensor nodes deployment.","PeriodicalId":265175,"journal":{"name":"2010 IEEE/IFIP International Conference on Embedded and Ubiquitous Computing","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2010-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127687469","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}
Dongxi Liu, Jack Lee, Julian Jang, S. Nepal, J. Zic
We propose and implement a cloud architecture of virtual TPMs. In this architecture, TPM instances can be obtained from the TPM cloud on demand. Hence, the TPM functionality is available for applications that do not have TPM chips in their local platforms. Moreover, users can access their keys and data in the same TPM instance even if they move to other platforms. The TPM functionality in cloud is easy to access for applications developed in different languages since cloud computing delivers services in standard protocols. The functionality of the TPM cloud is demonstrated by using it to implement the Needham-Schroeder public-key protocol for web authentication.
{"title":"A Cloud Architecture of Virtual Trusted Platform Modules","authors":"Dongxi Liu, Jack Lee, Julian Jang, S. Nepal, J. Zic","doi":"10.1109/EUC.2010.125","DOIUrl":"https://doi.org/10.1109/EUC.2010.125","url":null,"abstract":"We propose and implement a cloud architecture of virtual TPMs. In this architecture, TPM instances can be obtained from the TPM cloud on demand. Hence, the TPM functionality is available for applications that do not have TPM chips in their local platforms. Moreover, users can access their keys and data in the same TPM instance even if they move to other platforms. The TPM functionality in cloud is easy to access for applications developed in different languages since cloud computing delivers services in standard protocols. The functionality of the TPM cloud is demonstrated by using it to implement the Needham-Schroeder public-key protocol for web authentication.","PeriodicalId":265175,"journal":{"name":"2010 IEEE/IFIP International Conference on Embedded and Ubiquitous Computing","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2010-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124941248","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}
The rapid growth of emerging techniques for mobile resource sharing, content sharing, mobile social networks, and complex cyber-physical systems poses significant challenges for trust and security management. Several trust management schemes have been proposed recently to counter the security threat on Peer-to-Peer (P2P) systems. However, due to the difficulties caused by system mobility, wireless communications, pervasive devices and dynamic network topology, there is an increasing requirement of decentralized and distributed trust management schemes. In this paper, we first investigate and analyze various existing decentralized and distributed trust management schemes. Based on the analytical results, an efficient, accurate, robust and scalable light weight trust ratings aggregation scheme, referred to as M-trust, is proposed for mobile P2P networks. Extensive simulation results show that this proposed scheme can decrease the time required to compute the list of trust ratings and reduce the required storage space. The comparison to other schemes demonstrates that M-trust possesses the excellent overall performance in terms of accuracy, reliability, convergence speed, and detection rate under various constraints of mobility, trust threshold and network out-degree.
{"title":"M-Trust: A Trust Management Scheme for Mobile P2P Networks","authors":"B. Qureshi, G. Min, D. Kouvatsos","doi":"10.1109/EUC.2010.79","DOIUrl":"https://doi.org/10.1109/EUC.2010.79","url":null,"abstract":"The rapid growth of emerging techniques for mobile resource sharing, content sharing, mobile social networks, and complex cyber-physical systems poses significant challenges for trust and security management. Several trust management schemes have been proposed recently to counter the security threat on Peer-to-Peer (P2P) systems. However, due to the difficulties caused by system mobility, wireless communications, pervasive devices and dynamic network topology, there is an increasing requirement of decentralized and distributed trust management schemes. In this paper, we first investigate and analyze various existing decentralized and distributed trust management schemes. Based on the analytical results, an efficient, accurate, robust and scalable light weight trust ratings aggregation scheme, referred to as M-trust, is proposed for mobile P2P networks. Extensive simulation results show that this proposed scheme can decrease the time required to compute the list of trust ratings and reduce the required storage space. The comparison to other schemes demonstrates that M-trust possesses the excellent overall performance in terms of accuracy, reliability, convergence speed, and detection rate under various constraints of mobility, trust threshold and network out-degree.","PeriodicalId":265175,"journal":{"name":"2010 IEEE/IFIP International Conference on Embedded and Ubiquitous Computing","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2010-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115337590","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}
With the advancement of mobile devices' capabilities, it is possible to implement knowledge-based systems on the mobile devices. This development introduces a challenge of transferring knowledge between mobile devices and knowledge-based systems on the server side. This paper presents a novel representation, Entity Notation, to tackle this challenge. It can represent ontology knowledge in a straightforward fashion and allows incremental transfer of ontology. This unique feature makes Entity Notation an ideal solution for transferring knowledge in highly dynamic ubiquitous environments. Moreover, Entity Notation has a short format suitable for communication when resources are constrained. We address the design issues of the representation, demonstrate its usability by a small ontology, and evaluate it based on a set of ubiquitous ontologies.
{"title":"Transferring Ontologies between Mobile Devices and Knowledge-Based Systems","authors":"Xiang Su, J. Riekki","doi":"10.1109/EUC.2010.28","DOIUrl":"https://doi.org/10.1109/EUC.2010.28","url":null,"abstract":"With the advancement of mobile devices' capabilities, it is possible to implement knowledge-based systems on the mobile devices. This development introduces a challenge of transferring knowledge between mobile devices and knowledge-based systems on the server side. This paper presents a novel representation, Entity Notation, to tackle this challenge. It can represent ontology knowledge in a straightforward fashion and allows incremental transfer of ontology. This unique feature makes Entity Notation an ideal solution for transferring knowledge in highly dynamic ubiquitous environments. Moreover, Entity Notation has a short format suitable for communication when resources are constrained. We address the design issues of the representation, demonstrate its usability by a small ontology, and evaluate it based on a set of ubiquitous ontologies.","PeriodicalId":265175,"journal":{"name":"2010 IEEE/IFIP International Conference on Embedded and Ubiquitous Computing","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2010-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115470876","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}
Energy efficiency should be considered as a key design objective in wireless sensor networks (WSNs), since a sensor node can only be equipped with a limited energy supply. Clustering is one of the well-known design methods for managing the energy consumption in WSNs. Rotating role of cluster heads (CH) among nodes in these networks is an important issue in some of clustering methods. Directly collecting information about the energy level of nodes in each round increases the cost of CH role rotation, in the field of centralized hierarchical methods. In this paper, we proposed a centralized clustering algorithm that utilize hidden Markov model (HMM) optimized by particle swarm optimization (PSO) to predict the energy level of the network. In the next step, the appropriate CHs are selected by PSO algorithm. Our proposed method reduces the cost of clustering and in the mean time increases clustering performance. Evaluation results demonstrate by comparison with famous clustering algorithms, our scheme is energy efficient and increase network life time.
{"title":"An Efficient Clustering Algorithm Using Evolutionary HMM in Wireless Sensor Networks","authors":"Rouhollah Goudarzi, Behrouz Jedari, M. Sabaei","doi":"10.1109/EUC.2010.67","DOIUrl":"https://doi.org/10.1109/EUC.2010.67","url":null,"abstract":"Energy efficiency should be considered as a key design objective in wireless sensor networks (WSNs), since a sensor node can only be equipped with a limited energy supply. Clustering is one of the well-known design methods for managing the energy consumption in WSNs. Rotating role of cluster heads (CH) among nodes in these networks is an important issue in some of clustering methods. Directly collecting information about the energy level of nodes in each round increases the cost of CH role rotation, in the field of centralized hierarchical methods. In this paper, we proposed a centralized clustering algorithm that utilize hidden Markov model (HMM) optimized by particle swarm optimization (PSO) to predict the energy level of the network. In the next step, the appropriate CHs are selected by PSO algorithm. Our proposed method reduces the cost of clustering and in the mean time increases clustering performance. Evaluation results demonstrate by comparison with famous clustering algorithms, our scheme is energy efficient and increase network life time.","PeriodicalId":265175,"journal":{"name":"2010 IEEE/IFIP International Conference on Embedded and Ubiquitous Computing","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2010-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121726322","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}
The currently proposed anonymous routing mechanisms for Mobile Ad hoc Networks enable network entities to anonymously and securely communicate with each other. However, protocols that provide a high level of anonymity generally have poor scalability due to delays and overhead introduced by cryptographic operations, while other approaches sacrifice anonymity to achieve better performance. In this paper, we propose a novel anonymous routing protocol that provides improved anonymity and security while achieving similar or better performance, as compared to existing proposals. Our proposal achieves anonymity using a novel efficient solution for invisible implicit addressing based on keyed hash chain and security via a novel application of one-to-many Diffie-Hellman mechanism, used to exchange keys for symmetric encryption. The final contribution includes a mechanism to facilitate selection of a trusted route by verifying connections between intermediate nodes. We demonstrate the benefits of our proposal in comparison with previous approaches using analysis and simulation.
{"title":"TARo: Trusted Anonymous Routing for MANETs","authors":"Jiefeng Chen, R. Boreli, V. Sivaraman","doi":"10.1109/EUC.2010.119","DOIUrl":"https://doi.org/10.1109/EUC.2010.119","url":null,"abstract":"The currently proposed anonymous routing mechanisms for Mobile Ad hoc Networks enable network entities to anonymously and securely communicate with each other. However, protocols that provide a high level of anonymity generally have poor scalability due to delays and overhead introduced by cryptographic operations, while other approaches sacrifice anonymity to achieve better performance. In this paper, we propose a novel anonymous routing protocol that provides improved anonymity and security while achieving similar or better performance, as compared to existing proposals. Our proposal achieves anonymity using a novel efficient solution for invisible implicit addressing based on keyed hash chain and security via a novel application of one-to-many Diffie-Hellman mechanism, used to exchange keys for symmetric encryption. The final contribution includes a mechanism to facilitate selection of a trusted route by verifying connections between intermediate nodes. We demonstrate the benefits of our proposal in comparison with previous approaches using analysis and simulation.","PeriodicalId":265175,"journal":{"name":"2010 IEEE/IFIP International Conference on Embedded and Ubiquitous Computing","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2010-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115270116","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}
Many existing Wireless Sensor Network (WSN) synchronisation protocols have demonstrated microsecond-level accuracy is achievable. Furthermore, sub-microsecond-level accuracy has recently been reported, although rather sophisticated, relatively bulky and custom-designed hardware were needed. This paper addresses a fundamental problem in WSN synchronisation: is there a more elegant way to achieve precise synchronisation in WSN? What are the obstacles to pushing the limit in WSN synchronisation? This paper identified the drawbacks caused by the assumptions made in existing WSN synchronisation protocols, and presented and discussed a range of novel solutions to improve the accuracy, reliability and scalability of WSN synchronisation through fusing various types of information and a sensible selection of hardware.
{"title":"Towards Precise Synchronisation in Wireless Sensor Networks","authors":"L. Cheng, S. Hailes, Alan M. Wilson","doi":"10.1109/EUC.2010.38","DOIUrl":"https://doi.org/10.1109/EUC.2010.38","url":null,"abstract":"Many existing Wireless Sensor Network (WSN) synchronisation protocols have demonstrated microsecond-level accuracy is achievable. Furthermore, sub-microsecond-level accuracy has recently been reported, although rather sophisticated, relatively bulky and custom-designed hardware were needed. This paper addresses a fundamental problem in WSN synchronisation: is there a more elegant way to achieve precise synchronisation in WSN? What are the obstacles to pushing the limit in WSN synchronisation? This paper identified the drawbacks caused by the assumptions made in existing WSN synchronisation protocols, and presented and discussed a range of novel solutions to improve the accuracy, reliability and scalability of WSN synchronisation through fusing various types of information and a sensible selection of hardware.","PeriodicalId":265175,"journal":{"name":"2010 IEEE/IFIP International Conference on Embedded and Ubiquitous Computing","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2010-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127638157","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}
In our previous work, we proposed a novel approach to partition sensors on wireless sensor network, called node coverage grouping (NCG), where sensors in the connectivity group are within sensing range of each other, and their collected data are assumed to be similar. Power saving was achieved by alternatively turning on a sensor in a connectivity group for working. We also proved that partitioning n nodes by node coverage grouping into connectivity groups is a NP-hard problem, and proposed a heuristic algorithm of node coverage grouping with the time complexity of O(n3). In this paper, we present two approaches, called periodic probing and next-turn probing, to address the avoidance of blind period for the node coverage grouping. The experimental results showed that the NCG applying the avoidance of blind period would have shorter blind period than two other power saving approaches on wireless sensor network, the Lightweight Deployment-Aware Scheduling (LDAS) and the Probing Environment and Adaptive Sleeping (PEAS). In conclusion, the NCG-next-turn probing outperformed the LDAS and the PEAS with more number of living nodes, more coverage, and shorter blind period with respect to the proceeding of the system lifetime.
{"title":"Avoidance of Blind Period for Node Coverage Grouping on Wireless Sensor Networks","authors":"Chow-Sing Lin, Chih-Chung Chen","doi":"10.1109/EUC.2010.74","DOIUrl":"https://doi.org/10.1109/EUC.2010.74","url":null,"abstract":"In our previous work, we proposed a novel approach to partition sensors on wireless sensor network, called node coverage grouping (NCG), where sensors in the connectivity group are within sensing range of each other, and their collected data are assumed to be similar. Power saving was achieved by alternatively turning on a sensor in a connectivity group for working. We also proved that partitioning n nodes by node coverage grouping into connectivity groups is a NP-hard problem, and proposed a heuristic algorithm of node coverage grouping with the time complexity of O(n3). In this paper, we present two approaches, called periodic probing and next-turn probing, to address the avoidance of blind period for the node coverage grouping. The experimental results showed that the NCG applying the avoidance of blind period would have shorter blind period than two other power saving approaches on wireless sensor network, the Lightweight Deployment-Aware Scheduling (LDAS) and the Probing Environment and Adaptive Sleeping (PEAS). In conclusion, the NCG-next-turn probing outperformed the LDAS and the PEAS with more number of living nodes, more coverage, and shorter blind period with respect to the proceeding of the system lifetime.","PeriodicalId":265175,"journal":{"name":"2010 IEEE/IFIP International Conference on Embedded and Ubiquitous Computing","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2010-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126431136","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}
To handle the triple hidden terminal problems, this paper proposes OCO, an asynchronous multi-channel MAC protocol with opportunistic cooperation for wireless sensor networks. By adopting opportunistic cooperation, OCO effectively alleviates, if not eliminates, the triple hidden terminal problems. More importantly, OCO is fully distributed with no requirements of time synchronization or multi-radio scheme, so it is easy to be implemented on the real sensor nodes. Via the theoretical analysis, the opportunistic probability that a node cooperates with its neighbor is obtained. To validate the effectiveness of opportunistic cooperation, extensive simulations and real test bed experiments were con-ducted. The simulation and experimental results show that when the number of channels is large or the network loads are heavy, OCO improves energy efficiency and throughput significantly compared with other works in the literature.
{"title":"OCO: A Multi-channel MAC Protocol with Opportunistic Cooperation for Wireless Sensor Networks","authors":"Jinbao Li, Desheng Zhang, Longjiang Guo","doi":"10.1109/EUC.2010.45","DOIUrl":"https://doi.org/10.1109/EUC.2010.45","url":null,"abstract":"To handle the triple hidden terminal problems, this paper proposes OCO, an asynchronous multi-channel MAC protocol with opportunistic cooperation for wireless sensor networks. By adopting opportunistic cooperation, OCO effectively alleviates, if not eliminates, the triple hidden terminal problems. More importantly, OCO is fully distributed with no requirements of time synchronization or multi-radio scheme, so it is easy to be implemented on the real sensor nodes. Via the theoretical analysis, the opportunistic probability that a node cooperates with its neighbor is obtained. To validate the effectiveness of opportunistic cooperation, extensive simulations and real test bed experiments were con-ducted. The simulation and experimental results show that when the number of channels is large or the network loads are heavy, OCO improves energy efficiency and throughput significantly compared with other works in the literature.","PeriodicalId":265175,"journal":{"name":"2010 IEEE/IFIP International Conference on Embedded and Ubiquitous Computing","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2010-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124688639","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：