Optimizing routing and resource allocation in decentralized unmanned aerial vehicle(UAV)networks remains challenging due to interference and rapidly changing topologies.The authors introduce a novel framework combinin...Optimizing routing and resource allocation in decentralized unmanned aerial vehicle(UAV)networks remains challenging due to interference and rapidly changing topologies.The authors introduce a novel framework combining double deep Q-networks(DDQNs)and graph neural networks(GNNs)for joint routing and resource allocation.The framework uses GNNs to model the network topology and DDQNs to adaptively control routing and resource allocation,addressing interference and improving network performance.Simulation results show that the proposed approach outperforms traditional methods such as Closest-to-Destination(c2Dst),Max-SINR(mSINR),and Multi-Layer Perceptron(MLP)-based models,achieving approximately 23.5% improvement in throughput,50% increase in connection probability,and 17.6% reduction in number of hops,demonstrating its effectiveness in dynamic UAV networks.展开更多
Intensely using online social networks(OSNs)makes users concerned about privacy of data.Given the centralized nature of these platforms,and since each platform has a particular storage mechanism,authentication,and acc...Intensely using online social networks(OSNs)makes users concerned about privacy of data.Given the centralized nature of these platforms,and since each platform has a particular storage mechanism,authentication,and access control,their users do not have the control and the right over their data.Therefore,users cannot easily switch between similar platforms or transfer data from one platform to another.These issues imply,among other things,a threat to privacy since such users depend on the interests of the service provider responsible for administering OSNs.As a strategy for the decentralization of the OSNs and,consequently,as a solution to the privacy problems in these environments,the so-called decentralized online social networks(DOSNs)have emerged.Unlike OSNs,DOSNs are decentralized content management platforms because they do not use centralized service providers.Although DOSNs address some of the privacy issues encountered in OSNs,DOSNs also pose significant challenges to consider,for example,access control to user profile information with high granularity.This work proposes developing an ontological model and a service to support privacy in DOSNs.The model describes the main concepts of privacy access control in DOSNs and their relationships.In addition,the service will consume the model to apply access control according to the policies represented in the model.Our model was evaluated in two phases to verify its compliance with the proposed domain.Finally,we evaluated our service with a performance evaluation,and the results were satisfactory concerning the response time of access control requests.展开更多
Abstract--This paper provides a survey on modeling and theories of networked control systems （NCS）. In the first part, modeling of the different types of imperfections that affect NCS is discussed. These imperfectio...Abstract--This paper provides a survey on modeling and theories of networked control systems （NCS）. In the first part, modeling of the different types of imperfections that affect NCS is discussed. These imperfections are quantization errors, packet dropouts, variable sampling/transmission intervals, vari- able transmission delays, and communication constraints. Then follows in the second part a presentation of several theories that have been applied for controlling networked systems. These theories include： input delay system approach, Markovian system approach, switched system approach, stochastic system approach, impulsive system approach, and predictive control approach. In the last part, some advanced issues in NCS including decentral- ized and distributed NCS, cloud control system, and co-design of NCS are reviewed. Index Terms--Decentralized networked control systems （NCS）, distributed networked control systems, network constraints, net- worked control system, quantization, time delays.展开更多
This paper introduces federated services as a smart service ecology with federated security to align distributed data supply with diversified service demands spanning digital and societal contexts.It presents the comp...This paper introduces federated services as a smart service ecology with federated security to align distributed data supply with diversified service demands spanning digital and societal contexts.It presents the comprehensive researches on the theoretical foundation and technical system of federated services,aiming at advancing our understanding and implementation of this novel service paradigm.First,a thorough examination of the characteristics of federated security within federated services is conducted.Then,a five-layer technical framework is formulated under a decentralized intelligent architecture,ensuring secure,agile,and adaptable service provision.On this basis,the operational mechanisms underlying data federation and service confederation is analyzed,with emphasis on the smart supply-demand matching model.Furthermore,a scenario-oriented taxonomy of federated services accompanied by illustrative examples is proposed.Our work offers actionable insights and roadmap for realizing and advancing federated services,contributing to the refinement and wider adoption of this transformative service paradigm in the digital era.展开更多
The traditionally centralized approach of electricity networks is progressively undergoing a shift towards a decentralized, distributed structure. The local and crowd-based principle is transforming the existing suppl...The traditionally centralized approach of electricity networks is progressively undergoing a shift towards a decentralized, distributed structure. The local and crowd-based principle is transforming the existing supply chain and related activities into a value network （VN）. Previous researches on crowd value network concepts focus on the activities of infrastructure and load management and neglect activities that generate collaboration. Collaboration with and within crowds particularly demands a different mindset and management of sharing values, information, benefit, and risks. Furthermore, these concepts must integrate technical, processual, and social aspects. Thus, this article proposes a holistic framework of electricity VN management for crowd energy. It redefines VN activities for infrastructure and load management while appending VN activities for social electricity handling. Additionally, the framework illustrates the interactions among these three elements and concludes with an adaption cycle for the crowd value network.展开更多
The advent of blockchain technology has transformed traditional methods of information exchange,shifting reliance from centralized data centers to decentralized frameworks.While blockchain’s decentralization and secu...The advent of blockchain technology has transformed traditional methods of information exchange,shifting reliance from centralized data centers to decentralized frameworks.While blockchain’s decentralization and security are strengths,traditional consensus mechanisms like Proof of Work(PoW)and Proof of Stake(PoS)face limitations in scalability.PoW achieves decentralization and security but struggles with scalability as transaction volumes grow,while PoS enhances scalability,but risks centralization due to monopolization by high-stake participants.Sharding,a recent advancement in blockchain technology,addresses scalability by partitioning the network into shards that process transactions independently,thereby improving throughput and reducing latency.However,cross-shard communication,essential for transactions involving multiple shards,introduces challenges in coordination and fault tolerance.This research introduces a shard-based hybrid consensus model,PoSW,which combines PoW and PoS to mitigate the limitations of both mechanisms.By integrating PoW’s fairness with PoS’s scalability in a shard-based blockchain,the proposed model addresses key issues of scalability and monopolization.We evaluate the model against state-of-the-art consensus algorithms,including Monoxide and Practical Byzantine Fault Tolerance(PBFT).The results show that the proposed PoSW model reduces communication overhead compared to PBFT and improves resource utilization over Monoxide.In addition to performance gains,the security analysis demonstrates that the PoSW model provides robust defense against common blockchain attacks such as the 51%and Sybil attacks,etc.The proposed approach is particularly suited for applications like decentralized finance(DeFi)and supply chain management,which require both high scalability and robust security.The contributions of this research include the development of the PoSW hybrid consensus mechanism,its comparative evaluation with leading algorithms,and a thorough security analysis.These contributions represent a significant step forward in addressing blockchain’s scalability,fairness,and security challenges.展开更多
Decentralized Storage Networks(DSNs)represent a paradigm shift in data storage methodology,distributing and housing data across multiple network nodes rather than relying on a centralized server or data center archite...Decentralized Storage Networks(DSNs)represent a paradigm shift in data storage methodology,distributing and housing data across multiple network nodes rather than relying on a centralized server or data center architecture.The fundamental objective of DSNs is to enhance security,reinforce reliability,and mitigate censorship risks by eliminating a single point of failure.Leveraging blockchain technology for functions such as access control,ownership validation,and transaction facilitation,DSN initiatives aim to provide users with a robust and secure alternative to traditional centralized storage solutions.This paper conducts a comprehensive analysis of the developmental trajectory of DSNs,focusing on key components such as Proof of Storage protocols,consensus algorithms,and incentive mechanisms.Additionally,the study explores recent optimization tactics,encountered challenges,and potential avenues for future research,thereby offering insights into the ongoing evolution and advancement within the DSN domain.展开更多
The early concept of knowledge graph originates from the idea of the semantic Web,which aims at using structured graphs to model the knowledge of the world and record the relationships that exist between things.Curren...The early concept of knowledge graph originates from the idea of the semantic Web,which aims at using structured graphs to model the knowledge of the world and record the relationships that exist between things.Currently publishing knowledge bases as open data on the Web has gained significant attention.In China,Chinese Information Processing Society of China(CIPS)launched the OpenKG in 2015 to foster the development of Chinese Open Knowledge Graphs.Unlike existing open knowledge-based programs,OpenKG chain is envisioned as a blockchain-based open knowledge infrastructure.This article introduces the first attempt at the implementation of sharing knowledge graphs on OpenKG chain,a blockchain-based trust network.We have completed the test of the underlying blockchain platform,and the on-chain test of OpenKG’s data set and tool set sharing as well as fine-grained knowledge crowdsourcing at the triple level.We have also proposed novel definitions:K-Point and OpenKG Token,which can be considered to be a measurement of knowledge value and user value.1,033 knowledge contributors have been involved in two months of testing on the blockchain,and the cumulative number of on-chain recordings triggered by real knowledge consumers has reached 550,000 with an average daily peak value of more than 10,000.For the first time,we have tested and realized on-chain sharing of knowledge at entity/triple granularity level.At present,all operations on the data sets and tool sets at OpenKG.CN,as well as the triplets at OpenBase,are recorded on the chain,and corresponding value will also be generated and assigned in a trusted mode.Via this effort,OpenKG chain looks forward to providing a more credible and traceable knowledge-sharing platform for the knowledge graph community.展开更多
文摘Optimizing routing and resource allocation in decentralized unmanned aerial vehicle(UAV)networks remains challenging due to interference and rapidly changing topologies.The authors introduce a novel framework combining double deep Q-networks(DDQNs)and graph neural networks(GNNs)for joint routing and resource allocation.The framework uses GNNs to model the network topology and DDQNs to adaptively control routing and resource allocation,addressing interference and improving network performance.Simulation results show that the proposed approach outperforms traditional methods such as Closest-to-Destination(c2Dst),Max-SINR(mSINR),and Multi-Layer Perceptron(MLP)-based models,achieving approximately 23.5% improvement in throughput,50% increase in connection probability,and 17.6% reduction in number of hops,demonstrating its effectiveness in dynamic UAV networks.
基金Fundação de AmparoàPesquisa do Estado da Bahia(FAPESB),Coordenação de Aperfeiçoamento de Pessoal de Nível Superior(CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico(CNPq)organizations for supporting the Graduate Program in Computer Science at the Federal University of Bahia.
文摘Intensely using online social networks(OSNs)makes users concerned about privacy of data.Given the centralized nature of these platforms,and since each platform has a particular storage mechanism,authentication,and access control,their users do not have the control and the right over their data.Therefore,users cannot easily switch between similar platforms or transfer data from one platform to another.These issues imply,among other things,a threat to privacy since such users depend on the interests of the service provider responsible for administering OSNs.As a strategy for the decentralization of the OSNs and,consequently,as a solution to the privacy problems in these environments,the so-called decentralized online social networks(DOSNs)have emerged.Unlike OSNs,DOSNs are decentralized content management platforms because they do not use centralized service providers.Although DOSNs address some of the privacy issues encountered in OSNs,DOSNs also pose significant challenges to consider,for example,access control to user profile information with high granularity.This work proposes developing an ontological model and a service to support privacy in DOSNs.The model describes the main concepts of privacy access control in DOSNs and their relationships.In addition,the service will consume the model to apply access control according to the policies represented in the model.Our model was evaluated in two phases to verify its compliance with the proposed domain.Finally,we evaluated our service with a performance evaluation,and the results were satisfactory concerning the response time of access control requests.
基金supported by the Deanship of Scientific Research(DSR) at KFUPM through Research Project(IN141048)
文摘Abstract--This paper provides a survey on modeling and theories of networked control systems （NCS）. In the first part, modeling of the different types of imperfections that affect NCS is discussed. These imperfections are quantization errors, packet dropouts, variable sampling/transmission intervals, vari- able transmission delays, and communication constraints. Then follows in the second part a presentation of several theories that have been applied for controlling networked systems. These theories include： input delay system approach, Markovian system approach, switched system approach, stochastic system approach, impulsive system approach, and predictive control approach. In the last part, some advanced issues in NCS including decentral- ized and distributed NCS, cloud control system, and co-design of NCS are reviewed. Index Terms--Decentralized networked control systems （NCS）, distributed networked control systems, network constraints, net- worked control system, quantization, time delays.
基金supported by the National Key Research and Development Program of China(2021YFB2104800)the National Natural Science Foundation of China(62103411,62436010,72171230)the Science and Technology Development Fund of Macao SAR(0093/2023/RIA2,0050/2020/A1).
文摘This paper introduces federated services as a smart service ecology with federated security to align distributed data supply with diversified service demands spanning digital and societal contexts.It presents the comprehensive researches on the theoretical foundation and technical system of federated services,aiming at advancing our understanding and implementation of this novel service paradigm.First,a thorough examination of the characteristics of federated security within federated services is conducted.Then,a five-layer technical framework is formulated under a decentralized intelligent architecture,ensuring secure,agile,and adaptable service provision.On this basis,the operational mechanisms underlying data federation and service confederation is analyzed,with emphasis on the smart supply-demand matching model.Furthermore,a scenario-oriented taxonomy of federated services accompanied by illustrative examples is proposed.Our work offers actionable insights and roadmap for realizing and advancing federated services,contributing to the refinement and wider adoption of this transformative service paradigm in the digital era.
文摘The traditionally centralized approach of electricity networks is progressively undergoing a shift towards a decentralized, distributed structure. The local and crowd-based principle is transforming the existing supply chain and related activities into a value network （VN）. Previous researches on crowd value network concepts focus on the activities of infrastructure and load management and neglect activities that generate collaboration. Collaboration with and within crowds particularly demands a different mindset and management of sharing values, information, benefit, and risks. Furthermore, these concepts must integrate technical, processual, and social aspects. Thus, this article proposes a holistic framework of electricity VN management for crowd energy. It redefines VN activities for infrastructure and load management while appending VN activities for social electricity handling. Additionally, the framework illustrates the interactions among these three elements and concludes with an adaption cycle for the crowd value network.
文摘The advent of blockchain technology has transformed traditional methods of information exchange,shifting reliance from centralized data centers to decentralized frameworks.While blockchain’s decentralization and security are strengths,traditional consensus mechanisms like Proof of Work(PoW)and Proof of Stake(PoS)face limitations in scalability.PoW achieves decentralization and security but struggles with scalability as transaction volumes grow,while PoS enhances scalability,but risks centralization due to monopolization by high-stake participants.Sharding,a recent advancement in blockchain technology,addresses scalability by partitioning the network into shards that process transactions independently,thereby improving throughput and reducing latency.However,cross-shard communication,essential for transactions involving multiple shards,introduces challenges in coordination and fault tolerance.This research introduces a shard-based hybrid consensus model,PoSW,which combines PoW and PoS to mitigate the limitations of both mechanisms.By integrating PoW’s fairness with PoS’s scalability in a shard-based blockchain,the proposed model addresses key issues of scalability and monopolization.We evaluate the model against state-of-the-art consensus algorithms,including Monoxide and Practical Byzantine Fault Tolerance(PBFT).The results show that the proposed PoSW model reduces communication overhead compared to PBFT and improves resource utilization over Monoxide.In addition to performance gains,the security analysis demonstrates that the PoSW model provides robust defense against common blockchain attacks such as the 51%and Sybil attacks,etc.The proposed approach is particularly suited for applications like decentralized finance(DeFi)and supply chain management,which require both high scalability and robust security.The contributions of this research include the development of the PoSW hybrid consensus mechanism,its comparative evaluation with leading algorithms,and a thorough security analysis.These contributions represent a significant step forward in addressing blockchain’s scalability,fairness,and security challenges.
基金supported by the National Key R&D Program of China(2022YFB4501000)the National Natural Science Foundation of China(62232010,62302266,and U23A20302)+1 种基金Shandong Science Fund for Excellent Young Scholars(2023HWYQ-008)Shandong Science Fund for Key Fundamental Research Project(ZR2022ZD02)。
文摘Decentralized Storage Networks(DSNs)represent a paradigm shift in data storage methodology,distributing and housing data across multiple network nodes rather than relying on a centralized server or data center architecture.The fundamental objective of DSNs is to enhance security,reinforce reliability,and mitigate censorship risks by eliminating a single point of failure.Leveraging blockchain technology for functions such as access control,ownership validation,and transaction facilitation,DSN initiatives aim to provide users with a robust and secure alternative to traditional centralized storage solutions.This paper conducts a comprehensive analysis of the developmental trajectory of DSNs,focusing on key components such as Proof of Storage protocols,consensus algorithms,and incentive mechanisms.Additionally,the study explores recent optimization tactics,encountered challenges,and potential avenues for future research,thereby offering insights into the ongoing evolution and advancement within the DSN domain.
文摘The early concept of knowledge graph originates from the idea of the semantic Web,which aims at using structured graphs to model the knowledge of the world and record the relationships that exist between things.Currently publishing knowledge bases as open data on the Web has gained significant attention.In China,Chinese Information Processing Society of China(CIPS)launched the OpenKG in 2015 to foster the development of Chinese Open Knowledge Graphs.Unlike existing open knowledge-based programs,OpenKG chain is envisioned as a blockchain-based open knowledge infrastructure.This article introduces the first attempt at the implementation of sharing knowledge graphs on OpenKG chain,a blockchain-based trust network.We have completed the test of the underlying blockchain platform,and the on-chain test of OpenKG’s data set and tool set sharing as well as fine-grained knowledge crowdsourcing at the triple level.We have also proposed novel definitions:K-Point and OpenKG Token,which can be considered to be a measurement of knowledge value and user value.1,033 knowledge contributors have been involved in two months of testing on the blockchain,and the cumulative number of on-chain recordings triggered by real knowledge consumers has reached 550,000 with an average daily peak value of more than 10,000.For the first time,we have tested and realized on-chain sharing of knowledge at entity/triple granularity level.At present,all operations on the data sets and tool sets at OpenKG.CN,as well as the triplets at OpenBase,are recorded on the chain,and corresponding value will also be generated and assigned in a trusted mode.Via this effort,OpenKG chain looks forward to providing a more credible and traceable knowledge-sharing platform for the knowledge graph community.
