During the period 1978-1987, 255 patients with pathologically proven hepatocellular carcinoma (HCC) were determined by laparotomy to be un-resectable, 155 (60.8%) out of them had their tumor mainly confined in right o...During the period 1978-1987, 255 patients with pathologically proven hepatocellular carcinoma (HCC) were determined by laparotomy to be un-resectable, 155 (60.8%) out of them had their tumor mainly confined in right or left lobe and considered to be potentially resectable if remarkable tumor shrinkage appears after treatment. Second look operation was performed in 26 (16.8%) out of the 155 patients after marked reduction of tumor size, resection was done in all of these 26 patients. Triple or quadruple combination treatment with hepatic artery ligation (HAL), hepatic artery infusion (HAI) with chemotherapy, radiotherapy using linear accelerator, and radioimmunotherapy using 131-I antihu-man HCC ferritin antibody yielded the highest conversion rate (29.8%, 14/47) as compared to double combination treatment with HAL+HAI, or cryosur-gery+HAL (16.9%, 12/71) and single treatment with HAL or HAI or HAE (embolization) (0%, 0/37). The median tumor size of these 26 patients was reduced from 9.5 cm to 5.0 cm after combination treatment. The median interval between the first laparotomy and the subsequent resection was 5.0 (2-16) months. The survival rates calculated by life table method were: 1-year 86.5%, 2-year 74.3% and 3-year 74.3%. Nine cases have survival more than 3 years. Thus, multimodality combination treatment with subsequent resection might prolong survival significantly for some patients with unresectable HCC particularly confined in right lobe of a cirrhotic liver.展开更多
At Kuwana illegal dumping site in Japan, where hazardous waste was illegally dumped, groundwater was severely contaminated by Volatile Organic Compounds (VOCs). Groundwater was already remedied by conducting Pump-and-...At Kuwana illegal dumping site in Japan, where hazardous waste was illegally dumped, groundwater was severely contaminated by Volatile Organic Compounds (VOCs). Groundwater was already remedied by conducting Pump-and-Treat (P&T) after containment of all the waste by vertical slurry walls from 2002 to 2007. However, 1,4-dioxane was detected in both waste and groundwater outside of slurry walls after it was newly added into Japan environmental standards in late 2009, which suggested that the walls did not contain 1,4-dioxane completely. Our previous study developed a model to predict the 1,4-dioxane distribution in groundwater after the previous remediation at the site. In this study, numerical simulation was applied for remediation planning at the site based on the concept of Verified Follow Up (VF-UP) that had been proposed as a new approach to complete remediation effectively with consideration of future risks. The amount of waste to be removed and pumping plans were discussed by numerical simulation to achieve the remedial objective in which 1,4-dioxane in groundwater outside of walls is remedied within 10 years and 1,4-dioxane spreading throughout the walls is prevented in the case where a portion of waste is remained. Firstly, the amount of waste to be removed considering pumping plans for P&T was determined by scenario analysis. As a result, at least two-third of waste should be removed by combining with P&T. However, if the waste is remained, future risks of 1,4-dioxane spreading through the slurry walls may occur. Our simulation suggested that groundwater within the remaining waste must be pumped up at least 20 m3/d for containment of 1,4-dioxane within the remaining waste. In conclusion, our numerical simulation determined the amount of waste to be removed and the pumping plans for P&T to achieve the remedial objective effectively considering future risks based on the concept of VF-UP.展开更多
Consider an optimization problem arising from the generalized eigenvalue problem Ax=λBx,where A,B∈Cm×n and m>n.Ito et al.showed that the optimization problem can be solved by utilizing right singular vectors...Consider an optimization problem arising from the generalized eigenvalue problem Ax=λBx,where A,B∈Cm×n and m>n.Ito et al.showed that the optimization problem can be solved by utilizing right singular vectors of C:=[B,A].In this paper,we focus on computing intervals containing the solution.When some singular values of C are multiple or nearly multiple,we can enclose bases of corresponding invariant subspaces of CHC,where CH denotes the conjugate transpose of C,but cannot enclose the corresponding right singular vectors.The purpose of this paper is to prove that the solution can be obtained even when we utilize the bases instead of the right singular vectors.Based on the proved result,we propose an algorithm for computing the intervals.Numerical results show property of the algorithm.展开更多
Began from early 1992, Chongqing Power Supply Bureau had spent 3 and half years to build up a power load management system consisting of I master station, 6 relay stations, 1280 terminals and the distributed monitorin...Began from early 1992, Chongqing Power Supply Bureau had spent 3 and half years to build up a power load management system consisting of I master station, 6 relay stations, 1280 terminals and the distributed monitoring device. This system distributes in the hilly and mountainous areas where geographically complicated and the load widely scatters, it can supervise about 72% load and curtail more than 15% load展开更多
SIGNAL belongs to the synchronous languages family which are widely used in the design of safety-critical real-time systems such as avionics, space systems, and nu- clear power plants. This paper reports a compiler pr...SIGNAL belongs to the synchronous languages family which are widely used in the design of safety-critical real-time systems such as avionics, space systems, and nu- clear power plants. This paper reports a compiler prototype for SIGNAL. Compared with the existing SIGNAL com- piler, we propose a new intermediate representation （named S-CGA, a variant of clocked guarded actions）, to integrate more synchronous programs into our compiler prototype in the future. The front-end of the compiler, i.e., the transla- tion from SIGNAL to S-CGA, is presented. As well, the proof of semantics preservation is mechanized in the theo- rem prover Coq. Moreover, we present the back-end of the compiler, including sequential code generation and multi- threaded code generation with time-predictable properties. With the rising importance of multi-core processors in safety- critical embedded systems or cyber-physical systems （CPS）, there is a growing need for model-driven generation of multi- threaded code and thus mapping on multi-core. We propose a time-predictable multi-core architecture model in archi- tecture analysis and design language （AADL）, and map the multi-threaded code to this model.展开更多
Theproliferation of Internet of Things(IoT)devices introduces substantial security challenges.Currently,privacy constitutes a significant concern for individuals.While maintaining privacy within these systems is an es...Theproliferation of Internet of Things(IoT)devices introduces substantial security challenges.Currently,privacy constitutes a significant concern for individuals.While maintaining privacy within these systems is an essential characteristic,it often necessitates certain compromises,such as complexity and scalability,thereby complicating management efforts.The principal challenge lies in ensuring confidentiality while simultaneously preserving individuals’anonymity within the system.To address this,we present our proposed architecture for managing IoT devices using blockchain technology.Our proposed architecture works on and off blockchain and is integrated with dashcams and closed-circuit television(CCTV)security cameras.In this work,the videos recorded by the dashcams and CCTV security cameras are hashed through the InterPlanetary File System(IPFS)and this hash is stored in the blockchain.When the accessors want to access the video,they must pass through multiple authentications which include web token authentication and verifiable credentials,to mitigate the risk of malicious users.Our contributions include the proposition of the framework,which works on the single key for every new video,and a novel chaincode algorithm that incorporates verifiable credentials.Analyses are made to show the system’s throughput and latency through stress testing.Significant advantages of the proposed architecture are shown by comparing them to existing schemes.The proposed architecture features a robust design that significantly enhances the security of blockchain-enabled Internet of Things(IoT)deviceswhile effectively mitigating the risk of a single point of failure,which provides a reliable solution for security concerns in the IoT landscape.Our future endeavors will focus on scaling the system by integrating innovative methods to enhance security measures further.展开更多
The wide application of smart contracts allows industry companies to implement some complex distributed collaborative businesses,which involve the calculation of complex functions,such as matrix operations.However,com...The wide application of smart contracts allows industry companies to implement some complex distributed collaborative businesses,which involve the calculation of complex functions,such as matrix operations.However,complex functions such as matrix operations are difficult to implement on Ethereum Virtual Machine(EVM)-based smart contract platforms due to their distributed security environment limitations.Existing off-chain methods often result in a significant reduction in contract execution efficiency,thus a platform software development kit interface implementation method has become a feasible way to reduce overheads,but this method cannot verify operation correctness and may leak sensitive user data.To solve the above problems,we propose a verifiable EVM-based smart contract cross-language implementation scheme for complex operations,especially matrix operations,which can guarantee operation correctness and user privacy while ensuring computational efficiency.In this scheme,a verifiable interaction process is designed to verify the computation process and results,and a matrix blinding technology is introduced to protect sensitive user data in the calculation process.The security analysis and performance tests show that the proposed scheme can satisfy the correctness and privacy of the cross-language implementation of smart contracts at a small additional efficiency cost.展开更多
Distributed data fusion is essential for numerous applications,yet faces significant privacy security challenges.Federated learning(FL),as a distributed machine learning paradigm,offers enhanced data privacy protectio...Distributed data fusion is essential for numerous applications,yet faces significant privacy security challenges.Federated learning(FL),as a distributed machine learning paradigm,offers enhanced data privacy protection and has attracted widespread attention.Consequently,research increasingly focuses on developing more secure FL techniques.However,in real-world scenarios involving malicious entities,the accuracy of FL results is often compromised,particularly due to the threat of collusion between two servers.To address this challenge,this paper proposes an efficient and verifiable data aggregation protocol with enhanced privacy protection.After analyzing attack methods against prior schemes,we implement key improvements.Specifically,by incorporating cascaded random numbers and perturbation terms into gradients,we strengthen the privacy protection afforded by polynomial masking,effectively preventing information leakage.Furthermore,our protocol features an enhanced verification mechanism capable of detecting collusive behaviors between two servers.Accuracy testing on the MNIST and CIFAR-10 datasets demonstrates that our protocol maintains accuracy comparable to the Federated Averaging Algorithm.In scheme efficiency comparisons,while incurring only a marginal increase in verification overhead relative to the baseline scheme,our protocol achieves an average improvement of 93.13% in privacy protection and verification overhead compared to the state-of-the-art scheme.This result highlights its optimal balance between overall overhead and functionality.A current limitation is that the verificationmechanismcannot precisely pinpoint the source of anomalies within aggregated results when server-side malicious behavior occurs.Addressing this limitation will be a focus of future research.展开更多
Ciphertext-Policy Attribute-Based Encryption(CP-ABE)enables fine-grained access control on ciphertexts,making it a promising approach for managing data stored in the cloud-enabled Internet of Things.But existing schem...Ciphertext-Policy Attribute-Based Encryption(CP-ABE)enables fine-grained access control on ciphertexts,making it a promising approach for managing data stored in the cloud-enabled Internet of Things.But existing schemes often suffer from privacy breaches due to explicit attachment of access policies or partial hiding of critical attribute content.Additionally,resource-constrained IoT devices,especially those adopting wireless communication,frequently encounter affordability issues regarding decryption costs.In this paper,we propose an efficient and fine-grained access control scheme with fully hidden policies(named FHAC).FHAC conceals all attributes in the policy and utilizes bloom filters to efficiently locate them.A test phase before decryption is applied to assist authorized users in finding matches between their attributes and the access policy.Dictionary attacks are thwarted by providing unauthorized users with invalid values.The heavy computational overhead of both the test phase and most of the decryption phase is outsourced to two cloud servers.Additionally,users can verify the correctness of multiple outsourced decryption results simultaneously.Security analysis and performance comparisons demonstrate FHAC's effectiveness in protecting policy privacy and achieving efficient decryption.展开更多
This paper presents 3RVAV(Three-Round Voting with Advanced Validation),a novel Byzantine Fault Tolerant consensus protocol combining Proof-of-Stake with a multi-phase voting mechanism.The protocol introduces three lay...This paper presents 3RVAV(Three-Round Voting with Advanced Validation),a novel Byzantine Fault Tolerant consensus protocol combining Proof-of-Stake with a multi-phase voting mechanism.The protocol introduces three layers of randomized committee voting with distinct participant roles(Validators,Delegators,and Users),achieving(4/5)-threshold approval per round through a verifiable random function(VRF)-based selection process.Our security analysis demonstrates 3RVAV provides 1−(1−s/n)^(3k) resistance to Sybil attacks with n participants and stake s,while maintaining O(kn log n)communication complexity.Experimental simulations show 3247 TPS throughput with 4-s finality,representing a 5.8×improvement over Algorand’s committee-based approach.The proposed protocol achieves approximately 4.2-s finality,demonstrating low latency while maintaining strong consistency and resilience.The protocol introduces a novel punishment matrix incorporating both stake slashing and probabilistic blacklisting,proving a Nash equilibrium for honest participation under rational actor assumptions.展开更多
Federated Learning(FL)has emerged as a promising distributed machine learning paradigm that enables multi-party collaborative training while eliminating the need for raw data sharing.However,its reliance on a server i...Federated Learning(FL)has emerged as a promising distributed machine learning paradigm that enables multi-party collaborative training while eliminating the need for raw data sharing.However,its reliance on a server introduces critical security vulnerabilities:malicious servers can infer private information from received local model updates or deliberately manipulate aggregation results.Consequently,achieving verifiable aggregation without compromising client privacy remains a critical challenge.To address these problem,we propose a reversible data hiding in encrypted domains(RDHED)scheme,which designs joint secret message embedding and extraction mechanism.This approach enables clients to embed secret messages into ciphertext redundancy spaces generated during model encryption.During the server aggregation process,the embedded messages from all clients fuse within the ciphertext space to form a joint embedding message.Subsequently,clients can decrypt the aggregated results and extract this joint embedding message for verification purposes.Building upon this foundation,we integrate the proposed RDHED scheme with linear homomorphic hash and digital signatures to design a verifiable privacy-preserving aggregation protocol for single-server architectures(VPAFL).Theoretical proofs and experimental analyses show that VPAFL can effectively protect user privacy,achieve lightweight computational and communication overhead of users for verification,and present significant advantages with increasing model dimension.展开更多
To enable efficient sharing of unbounded streaming data,this paper introduces blockchain technology into traditional cloud data,proposing a hybrid on-chain/off-chain storage model.We design a real-time verifiable data...To enable efficient sharing of unbounded streaming data,this paper introduces blockchain technology into traditional cloud data,proposing a hybrid on-chain/off-chain storage model.We design a real-time verifiable data structure that is more suitable for streaming data to achieve efficient real-time verifiability for streaming data.Based on the notch gate hash function and vector commitment,an adaptive notch gate hash tree structure is constructed,and an efficient real-time verifiable data structure for on-chain and off-chain stream data is proposed.The structure binds dynamic root nodes sequentially to ordered leaf nodes in its child nodes.Only the vector commitment of the dynamic root node is stored on the chain,and the complete data structure is stored off-chain.This structure ensures tamperproofing against malicious off-chain cloud servers of off-chain cloud servers.Preserves storage scalability space,realizes the immediate verification of stream data upon arrival,and the computational overhead of on-chain and off-chain hybrid storage verification is only related to the current data volume,which is more practical when dealing with stream data with unpredictable data volume.We formalize this as an efficient real-time verification scheme for stream data in on-chain and off-chain hybrid storage.Finally,the technology’s security and performance were empirically validated through rigorous analysis.展开更多
Dear Editor,We present a modified surgical technique to verify the chorion layer of the human amniotic membrane(hAM)in treating retinal detachment(RD)with vitrectomy.RD patients with pathological myopia where the tear...Dear Editor,We present a modified surgical technique to verify the chorion layer of the human amniotic membrane(hAM)in treating retinal detachment(RD)with vitrectomy.RD patients with pathological myopia where the tear is located within the posterior pole choroidal atrophy area are difficult to treat.Surgical procedures such as laser treatments,diathermy,cryopexy applications or long-term silicone oil endotamponade may not only be ineffective but also harmful in these cases^([1]).Amniotic membrane transplantation(AMT)is an effective technique in case of RD recurrences to seal retinal holes over high myopic chorioretinal atrophy^([2]).展开更多
To prevent server compromise attack and password guessing attacks,an improved and efficient verifier-based key exchange protocol for three-party is proposed,which enables two clients to agree on a common session key w...To prevent server compromise attack and password guessing attacks,an improved and efficient verifier-based key exchange protocol for three-party is proposed,which enables two clients to agree on a common session key with the help of the server.In this protocol,the client stores a plaintext version of the password,while the server stores a verifier for the password.And the protocol uses verifiers to authenticate between clients and the server.The security analysis and performance comparison of the proposed protocol shows that the protocol can resist many familiar attacks including password guessing attacks,server compromise attacks,man-in-the-middle attacks and Denning-Sacco attacks,and it is more efficient.展开更多
With the rapid development of space technology, orbital spacecraft formation has received great attention from international and domestic academics and industry. Compared with a single monolithic, the orbital spacecra...With the rapid development of space technology, orbital spacecraft formation has received great attention from international and domestic academics and industry. Compared with a single monolithic, the orbital spacecraft formation system has many advantages. This paper presents an improved pigeon-inspired optimization（PIO） algorithm for solving the optimal formation reconfiguration problems of multiple orbital spacecraft. Considering that the uniform distribution random searching system in PIO has its own weakness, a modified PIO model adopting Gaussian strategy is presented and the detailed process is also given. Comparative experiments with basic PIO and particle swarm optimization（PSO） are conducted, and the results have verified the feasibility and effectiveness of the proposed Gaussian PIO（GPIO） in solving orbital spacecraft formation reconfiguration problems.展开更多
In the harsh environment where n ode density is sparse, the slow-moving nodes cannot effectively utilize the encountering opportunities to realize the self-organized identity authentications, and do not have the chanc...In the harsh environment where n ode density is sparse, the slow-moving nodes cannot effectively utilize the encountering opportunities to realize the self-organized identity authentications, and do not have the chance to join the network routing. However, considering m ost of the communications in opportunistic networks are caused by forwarding operations, there is no need to establish the complete mutual authentications for each conversation. Accordingly, a novel trust management scheme is presented based on the information of behavior feedback, in order to complement the insufficiency of identity authentications. By utilizing the certificate chains based on social attributes, the mobile nodes build the local certificate graphs gradually to realize the web of "Identity Trust" relationship. Meanwhile, the successors generate Verified Feedback Packets for each positive behavior, and consequently the "Behavior Trust" relationship is formed for slow-moving nodes. Simulation result shows that, by implementing our trust scheme, the d elivery probability and trust reconstruction ratio can be effectively improved when there are large numbers of compromised nodes, and it means that our trust management scheme can efficiently explore and filter the trust nodes for secure forwarding in opportunistic networks.展开更多
Owing to the increasing demand for harvesting energy from environmental vibration for use in self-powered electronic applications, cantilever-based vibration energy harvesting has attracted considerable interest from ...Owing to the increasing demand for harvesting energy from environmental vibration for use in self-powered electronic applications, cantilever-based vibration energy harvesting has attracted considerable interest from various parties and has become one of the most common approaches to converting redundant mechanical energy into electrical energy. As the output voltage produced from a piezoelectric material depends largely on the geometric shape and the size of the beam, there is a need to model and compare the performance of cantilever beams of differing geometries.This paper presents the study of strain distribution in various shapes of cantilever beams, including a convex and concave edge profile elliptical beam that have not yet been discussed in any prior literature. Both analytical and finite-element models are derived and the resultant strain distributions in the beam are computed based on a MATLAB solver and ANSYS finite-element analysis tools. An optimum geometry for a vibration-based energy harvesting system is verified.Finally, experimental results comparing the power density for triangular and rectangular piezoelectric beams are also presented to validate the findings of the study, and the claim, as suggested in the literature, is verified.展开更多
The strain dependent characteristics of hard coatings make the vibration analysis of hard-coated composite structure become a challenging task. In this study, the modeling and the analysis method of a hard-coated comp...The strain dependent characteristics of hard coatings make the vibration analysis of hard-coated composite structure become a challenging task. In this study, the modeling and the analysis method of a hard-coated composite beam was developed considering the strain dependent characteristics of coating material. Firstly, based on analyzing the properties of hard-coating material, a high order polynomial was adopted to characterize the strain dependent characteristics of coating materials. Then, the analytical model of a hard-coated composite beam was created by the energy method. Next, using the numerical method to solve the vibration response and the resonance frequencies of the composite beam, a specific calculation flow was also proposed. Finally,a cantilever beam coated with Mg O ＋ Al2_O_3 hard coating was chosen as the study case; under different excitation levels, the resonance region responses and the resonance frequencies of the composite beam were calculated using the proposed method. The calculation results were compared with the experiment and the linear calculation, and the correctness of the created model was verified. The study shows that compared with the general linear calculation, the proposed method can still maintain an acceptable precision when the excitation level is larger.展开更多
Neutral beam injection is recognized as one of the most effective means for plasma heating.The preliminary data of ion beam extraction is obtained on the EAST neutral beam injector test-stand.Beam extraction from the ...Neutral beam injection is recognized as one of the most effective means for plasma heating.The preliminary data of ion beam extraction is obtained on the EAST neutral beam injector test-stand.Beam extraction from the ion source of EAST-NBI is verified by measuring the beam current with a Faraday cup and by analyzing the results obtained by means of water calorimetric measurement on the temperature rises of water cooling the accelerator electrodes.展开更多
文摘During the period 1978-1987, 255 patients with pathologically proven hepatocellular carcinoma (HCC) were determined by laparotomy to be un-resectable, 155 (60.8%) out of them had their tumor mainly confined in right or left lobe and considered to be potentially resectable if remarkable tumor shrinkage appears after treatment. Second look operation was performed in 26 (16.8%) out of the 155 patients after marked reduction of tumor size, resection was done in all of these 26 patients. Triple or quadruple combination treatment with hepatic artery ligation (HAL), hepatic artery infusion (HAI) with chemotherapy, radiotherapy using linear accelerator, and radioimmunotherapy using 131-I antihu-man HCC ferritin antibody yielded the highest conversion rate (29.8%, 14/47) as compared to double combination treatment with HAL+HAI, or cryosur-gery+HAL (16.9%, 12/71) and single treatment with HAL or HAI or HAE (embolization) (0%, 0/37). The median tumor size of these 26 patients was reduced from 9.5 cm to 5.0 cm after combination treatment. The median interval between the first laparotomy and the subsequent resection was 5.0 (2-16) months. The survival rates calculated by life table method were: 1-year 86.5%, 2-year 74.3% and 3-year 74.3%. Nine cases have survival more than 3 years. Thus, multimodality combination treatment with subsequent resection might prolong survival significantly for some patients with unresectable HCC particularly confined in right lobe of a cirrhotic liver.
文摘At Kuwana illegal dumping site in Japan, where hazardous waste was illegally dumped, groundwater was severely contaminated by Volatile Organic Compounds (VOCs). Groundwater was already remedied by conducting Pump-and-Treat (P&T) after containment of all the waste by vertical slurry walls from 2002 to 2007. However, 1,4-dioxane was detected in both waste and groundwater outside of slurry walls after it was newly added into Japan environmental standards in late 2009, which suggested that the walls did not contain 1,4-dioxane completely. Our previous study developed a model to predict the 1,4-dioxane distribution in groundwater after the previous remediation at the site. In this study, numerical simulation was applied for remediation planning at the site based on the concept of Verified Follow Up (VF-UP) that had been proposed as a new approach to complete remediation effectively with consideration of future risks. The amount of waste to be removed and pumping plans were discussed by numerical simulation to achieve the remedial objective in which 1,4-dioxane in groundwater outside of walls is remedied within 10 years and 1,4-dioxane spreading throughout the walls is prevented in the case where a portion of waste is remained. Firstly, the amount of waste to be removed considering pumping plans for P&T was determined by scenario analysis. As a result, at least two-third of waste should be removed by combining with P&T. However, if the waste is remained, future risks of 1,4-dioxane spreading through the slurry walls may occur. Our simulation suggested that groundwater within the remaining waste must be pumped up at least 20 m3/d for containment of 1,4-dioxane within the remaining waste. In conclusion, our numerical simulation determined the amount of waste to be removed and the pumping plans for P&T to achieve the remedial objective effectively considering future risks based on the concept of VF-UP.
基金Partially Supported by JSPS KAKENHI(Grant No.JP16K05270)the Research Institute for Mathematical Sciences,a Joint Usage/Research Center located in Kyoto University
文摘Consider an optimization problem arising from the generalized eigenvalue problem Ax=λBx,where A,B∈Cm×n and m>n.Ito et al.showed that the optimization problem can be solved by utilizing right singular vectors of C:=[B,A].In this paper,we focus on computing intervals containing the solution.When some singular values of C are multiple or nearly multiple,we can enclose bases of corresponding invariant subspaces of CHC,where CH denotes the conjugate transpose of C,but cannot enclose the corresponding right singular vectors.The purpose of this paper is to prove that the solution can be obtained even when we utilize the bases instead of the right singular vectors.Based on the proved result,we propose an algorithm for computing the intervals.Numerical results show property of the algorithm.
文摘Began from early 1992, Chongqing Power Supply Bureau had spent 3 and half years to build up a power load management system consisting of I master station, 6 relay stations, 1280 terminals and the distributed monitoring device. This system distributes in the hilly and mountainous areas where geographically complicated and the load widely scatters, it can supervise about 72% load and curtail more than 15% load
文摘SIGNAL belongs to the synchronous languages family which are widely used in the design of safety-critical real-time systems such as avionics, space systems, and nu- clear power plants. This paper reports a compiler prototype for SIGNAL. Compared with the existing SIGNAL com- piler, we propose a new intermediate representation （named S-CGA, a variant of clocked guarded actions）, to integrate more synchronous programs into our compiler prototype in the future. The front-end of the compiler, i.e., the transla- tion from SIGNAL to S-CGA, is presented. As well, the proof of semantics preservation is mechanized in the theo- rem prover Coq. Moreover, we present the back-end of the compiler, including sequential code generation and multi- threaded code generation with time-predictable properties. With the rising importance of multi-core processors in safety- critical embedded systems or cyber-physical systems （CPS）, there is a growing need for model-driven generation of multi- threaded code and thus mapping on multi-core. We propose a time-predictable multi-core architecture model in archi- tecture analysis and design language （AADL）, and map the multi-threaded code to this model.
基金supported by the Institute of Information&Communications Technology Planning&Evaluation(IITP)(Project Nos.RS-2024-00438551,30%,2022-11220701,30%,2021-0-01816,30%)the National Research Foundation of Korea(NRF)grant funded by the Korean Government(Project No.RS-2023-00208460,10%).
文摘Theproliferation of Internet of Things(IoT)devices introduces substantial security challenges.Currently,privacy constitutes a significant concern for individuals.While maintaining privacy within these systems is an essential characteristic,it often necessitates certain compromises,such as complexity and scalability,thereby complicating management efforts.The principal challenge lies in ensuring confidentiality while simultaneously preserving individuals’anonymity within the system.To address this,we present our proposed architecture for managing IoT devices using blockchain technology.Our proposed architecture works on and off blockchain and is integrated with dashcams and closed-circuit television(CCTV)security cameras.In this work,the videos recorded by the dashcams and CCTV security cameras are hashed through the InterPlanetary File System(IPFS)and this hash is stored in the blockchain.When the accessors want to access the video,they must pass through multiple authentications which include web token authentication and verifiable credentials,to mitigate the risk of malicious users.Our contributions include the proposition of the framework,which works on the single key for every new video,and a novel chaincode algorithm that incorporates verifiable credentials.Analyses are made to show the system’s throughput and latency through stress testing.Significant advantages of the proposed architecture are shown by comparing them to existing schemes.The proposed architecture features a robust design that significantly enhances the security of blockchain-enabled Internet of Things(IoT)deviceswhile effectively mitigating the risk of a single point of failure,which provides a reliable solution for security concerns in the IoT landscape.Our future endeavors will focus on scaling the system by integrating innovative methods to enhance security measures further.
基金supported in part by the National Natural Science Foundation of China under Grant 62272007,U23B2002in part by the Excellent Young Talents Project of the Beijing Municipal University Teacher Team Construction Support Plan under Grant BPHR202203031+1 种基金in part by the Yunnan Key Laboratory of Blockchain Application Technology under Grant 2021105AG070005(YNB202102)in part by the Open Topics of Key Laboratory of Blockchain Technology and Data Security,The Ministry of Industry and Information Technology of the People’s Republic of China under Grant 20243222。
文摘The wide application of smart contracts allows industry companies to implement some complex distributed collaborative businesses,which involve the calculation of complex functions,such as matrix operations.However,complex functions such as matrix operations are difficult to implement on Ethereum Virtual Machine(EVM)-based smart contract platforms due to their distributed security environment limitations.Existing off-chain methods often result in a significant reduction in contract execution efficiency,thus a platform software development kit interface implementation method has become a feasible way to reduce overheads,but this method cannot verify operation correctness and may leak sensitive user data.To solve the above problems,we propose a verifiable EVM-based smart contract cross-language implementation scheme for complex operations,especially matrix operations,which can guarantee operation correctness and user privacy while ensuring computational efficiency.In this scheme,a verifiable interaction process is designed to verify the computation process and results,and a matrix blinding technology is introduced to protect sensitive user data in the calculation process.The security analysis and performance tests show that the proposed scheme can satisfy the correctness and privacy of the cross-language implementation of smart contracts at a small additional efficiency cost.
基金supported by National Key R&D Program of China(2023YFB3106100)National Natural Science Foundation of China(62102452,62172436)Natural Science Foundation of Shaanxi Province(2023-JCYB-584).
文摘Distributed data fusion is essential for numerous applications,yet faces significant privacy security challenges.Federated learning(FL),as a distributed machine learning paradigm,offers enhanced data privacy protection and has attracted widespread attention.Consequently,research increasingly focuses on developing more secure FL techniques.However,in real-world scenarios involving malicious entities,the accuracy of FL results is often compromised,particularly due to the threat of collusion between two servers.To address this challenge,this paper proposes an efficient and verifiable data aggregation protocol with enhanced privacy protection.After analyzing attack methods against prior schemes,we implement key improvements.Specifically,by incorporating cascaded random numbers and perturbation terms into gradients,we strengthen the privacy protection afforded by polynomial masking,effectively preventing information leakage.Furthermore,our protocol features an enhanced verification mechanism capable of detecting collusive behaviors between two servers.Accuracy testing on the MNIST and CIFAR-10 datasets demonstrates that our protocol maintains accuracy comparable to the Federated Averaging Algorithm.In scheme efficiency comparisons,while incurring only a marginal increase in verification overhead relative to the baseline scheme,our protocol achieves an average improvement of 93.13% in privacy protection and verification overhead compared to the state-of-the-art scheme.This result highlights its optimal balance between overall overhead and functionality.A current limitation is that the verificationmechanismcannot precisely pinpoint the source of anomalies within aggregated results when server-side malicious behavior occurs.Addressing this limitation will be a focus of future research.
基金supported in part by the National Key R&D Program of China(Grant No.2019YFB2101700)the National Natural Science Foundation of China(Grant No.62272102,No.62172320,No.U21A20466)+4 种基金the Open Research Fund of Key Laboratory of Cryptography of Zhejiang Province(Grant No.ZCL21015)the Qinghai Key R&D and Transformation Projects(Grant No.2021-GX-112)the Natural Science Foundation of Nanjing University of Posts and Telecommunications(Grant No.NY222141)the Natural Science Foundation of Jiangsu Higher Education Institutions of China under Grant(No.22KJB520029)Henan Key Laboratory of Network Cryptography Technology(No.LNCT2022-A10)。
文摘Ciphertext-Policy Attribute-Based Encryption(CP-ABE)enables fine-grained access control on ciphertexts,making it a promising approach for managing data stored in the cloud-enabled Internet of Things.But existing schemes often suffer from privacy breaches due to explicit attachment of access policies or partial hiding of critical attribute content.Additionally,resource-constrained IoT devices,especially those adopting wireless communication,frequently encounter affordability issues regarding decryption costs.In this paper,we propose an efficient and fine-grained access control scheme with fully hidden policies(named FHAC).FHAC conceals all attributes in the policy and utilizes bloom filters to efficiently locate them.A test phase before decryption is applied to assist authorized users in finding matches between their attributes and the access policy.Dictionary attacks are thwarted by providing unauthorized users with invalid values.The heavy computational overhead of both the test phase and most of the decryption phase is outsourced to two cloud servers.Additionally,users can verify the correctness of multiple outsourced decryption results simultaneously.Security analysis and performance comparisons demonstrate FHAC's effectiveness in protecting policy privacy and achieving efficient decryption.
文摘This paper presents 3RVAV(Three-Round Voting with Advanced Validation),a novel Byzantine Fault Tolerant consensus protocol combining Proof-of-Stake with a multi-phase voting mechanism.The protocol introduces three layers of randomized committee voting with distinct participant roles(Validators,Delegators,and Users),achieving(4/5)-threshold approval per round through a verifiable random function(VRF)-based selection process.Our security analysis demonstrates 3RVAV provides 1−(1−s/n)^(3k) resistance to Sybil attacks with n participants and stake s,while maintaining O(kn log n)communication complexity.Experimental simulations show 3247 TPS throughput with 4-s finality,representing a 5.8×improvement over Algorand’s committee-based approach.The proposed protocol achieves approximately 4.2-s finality,demonstrating low latency while maintaining strong consistency and resilience.The protocol introduces a novel punishment matrix incorporating both stake slashing and probabilistic blacklisting,proving a Nash equilibrium for honest participation under rational actor assumptions.
基金supported in part by the National Natural Science Foundation of China under Grants 62102450,62272478the Independent Research Project of a Certain Unit under Grant ZZKY20243127.
文摘Federated Learning(FL)has emerged as a promising distributed machine learning paradigm that enables multi-party collaborative training while eliminating the need for raw data sharing.However,its reliance on a server introduces critical security vulnerabilities:malicious servers can infer private information from received local model updates or deliberately manipulate aggregation results.Consequently,achieving verifiable aggregation without compromising client privacy remains a critical challenge.To address these problem,we propose a reversible data hiding in encrypted domains(RDHED)scheme,which designs joint secret message embedding and extraction mechanism.This approach enables clients to embed secret messages into ciphertext redundancy spaces generated during model encryption.During the server aggregation process,the embedded messages from all clients fuse within the ciphertext space to form a joint embedding message.Subsequently,clients can decrypt the aggregated results and extract this joint embedding message for verification purposes.Building upon this foundation,we integrate the proposed RDHED scheme with linear homomorphic hash and digital signatures to design a verifiable privacy-preserving aggregation protocol for single-server architectures(VPAFL).Theoretical proofs and experimental analyses show that VPAFL can effectively protect user privacy,achieve lightweight computational and communication overhead of users for verification,and present significant advantages with increasing model dimension.
基金supported by the National Cryptologic Science Fund of China(Grant No.2025NCSF02020)awarded to Yi Sunsupported by the Natural Science Foundation of Henan Province(Grant No.242300420297)awarded to Yi Sun。
文摘To enable efficient sharing of unbounded streaming data,this paper introduces blockchain technology into traditional cloud data,proposing a hybrid on-chain/off-chain storage model.We design a real-time verifiable data structure that is more suitable for streaming data to achieve efficient real-time verifiability for streaming data.Based on the notch gate hash function and vector commitment,an adaptive notch gate hash tree structure is constructed,and an efficient real-time verifiable data structure for on-chain and off-chain stream data is proposed.The structure binds dynamic root nodes sequentially to ordered leaf nodes in its child nodes.Only the vector commitment of the dynamic root node is stored on the chain,and the complete data structure is stored off-chain.This structure ensures tamperproofing against malicious off-chain cloud servers of off-chain cloud servers.Preserves storage scalability space,realizes the immediate verification of stream data upon arrival,and the computational overhead of on-chain and off-chain hybrid storage verification is only related to the current data volume,which is more practical when dealing with stream data with unpredictable data volume.We formalize this as an efficient real-time verification scheme for stream data in on-chain and off-chain hybrid storage.Finally,the technology’s security and performance were empirically validated through rigorous analysis.
文摘Dear Editor,We present a modified surgical technique to verify the chorion layer of the human amniotic membrane(hAM)in treating retinal detachment(RD)with vitrectomy.RD patients with pathological myopia where the tear is located within the posterior pole choroidal atrophy area are difficult to treat.Surgical procedures such as laser treatments,diathermy,cryopexy applications or long-term silicone oil endotamponade may not only be ineffective but also harmful in these cases^([1]).Amniotic membrane transplantation(AMT)is an effective technique in case of RD recurrences to seal retinal holes over high myopic chorioretinal atrophy^([2]).
基金The National High Technology Research and Development Program of China(863Program)(No.2001AA115300)the Natural Science Foundation of Liaoning Province(No.20031018,20062023)
文摘To prevent server compromise attack and password guessing attacks,an improved and efficient verifier-based key exchange protocol for three-party is proposed,which enables two clients to agree on a common session key with the help of the server.In this protocol,the client stores a plaintext version of the password,while the server stores a verifier for the password.And the protocol uses verifiers to authenticate between clients and the server.The security analysis and performance comparison of the proposed protocol shows that the protocol can resist many familiar attacks including password guessing attacks,server compromise attacks,man-in-the-middle attacks and Denning-Sacco attacks,and it is more efficient.
基金supported by the National Natural Science Foundation of China(Nos.61425008,61333004,61273054)the Top-Notch Young Talents Program of Chinathe Aeronautical Science Foundation of China(No.20135851042)
文摘With the rapid development of space technology, orbital spacecraft formation has received great attention from international and domestic academics and industry. Compared with a single monolithic, the orbital spacecraft formation system has many advantages. This paper presents an improved pigeon-inspired optimization（PIO） algorithm for solving the optimal formation reconfiguration problems of multiple orbital spacecraft. Considering that the uniform distribution random searching system in PIO has its own weakness, a modified PIO model adopting Gaussian strategy is presented and the detailed process is also given. Comparative experiments with basic PIO and particle swarm optimization（PSO） are conducted, and the results have verified the feasibility and effectiveness of the proposed Gaussian PIO（GPIO） in solving orbital spacecraft formation reconfiguration problems.
基金supported by the Program for Changjiang Scholars and Innovative Research Team in University (IRT1078)the Key Program of NSFC-Guangdong Union Foundation (U1135002)+3 种基金the Major national S&T program(2012ZX03002003)the Fundamental Research Funds for the Central Universities(JY10000903001)the National Natural Sci ence Foundation of China (Grant No. 61363068, 61100233)the Natural Science Foundation of Shaanxi Province (Grant No. 2012JM8030, 2011JQ8003)
文摘In the harsh environment where n ode density is sparse, the slow-moving nodes cannot effectively utilize the encountering opportunities to realize the self-organized identity authentications, and do not have the chance to join the network routing. However, considering m ost of the communications in opportunistic networks are caused by forwarding operations, there is no need to establish the complete mutual authentications for each conversation. Accordingly, a novel trust management scheme is presented based on the information of behavior feedback, in order to complement the insufficiency of identity authentications. By utilizing the certificate chains based on social attributes, the mobile nodes build the local certificate graphs gradually to realize the web of "Identity Trust" relationship. Meanwhile, the successors generate Verified Feedback Packets for each positive behavior, and consequently the "Behavior Trust" relationship is formed for slow-moving nodes. Simulation result shows that, by implementing our trust scheme, the d elivery probability and trust reconstruction ratio can be effectively improved when there are large numbers of compromised nodes, and it means that our trust management scheme can efficiently explore and filter the trust nodes for secure forwarding in opportunistic networks.
基金supported by the Fundamental Research Grant Scheme FRGS/1/2014/TK03/QUEST/03/1 from the Ministry of Education(MoE)Malaysia
文摘Owing to the increasing demand for harvesting energy from environmental vibration for use in self-powered electronic applications, cantilever-based vibration energy harvesting has attracted considerable interest from various parties and has become one of the most common approaches to converting redundant mechanical energy into electrical energy. As the output voltage produced from a piezoelectric material depends largely on the geometric shape and the size of the beam, there is a need to model and compare the performance of cantilever beams of differing geometries.This paper presents the study of strain distribution in various shapes of cantilever beams, including a convex and concave edge profile elliptical beam that have not yet been discussed in any prior literature. Both analytical and finite-element models are derived and the resultant strain distributions in the beam are computed based on a MATLAB solver and ANSYS finite-element analysis tools. An optimum geometry for a vibration-based energy harvesting system is verified.Finally, experimental results comparing the power density for triangular and rectangular piezoelectric beams are also presented to validate the findings of the study, and the claim, as suggested in the literature, is verified.
基金supported by the National Natural Science Foundation of China(Grant 51375079)the Fundamental Research Funds for the Central Universities of China(Grant N140301001)
文摘The strain dependent characteristics of hard coatings make the vibration analysis of hard-coated composite structure become a challenging task. In this study, the modeling and the analysis method of a hard-coated composite beam was developed considering the strain dependent characteristics of coating material. Firstly, based on analyzing the properties of hard-coating material, a high order polynomial was adopted to characterize the strain dependent characteristics of coating materials. Then, the analytical model of a hard-coated composite beam was created by the energy method. Next, using the numerical method to solve the vibration response and the resonance frequencies of the composite beam, a specific calculation flow was also proposed. Finally,a cantilever beam coated with Mg O ＋ Al2_O_3 hard coating was chosen as the study case; under different excitation levels, the resonance region responses and the resonance frequencies of the composite beam were calculated using the proposed method. The calculation results were compared with the experiment and the linear calculation, and the correctness of the created model was verified. The study shows that compared with the general linear calculation, the proposed method can still maintain an acceptable precision when the excitation level is larger.
基金Supported by the National Natural Science Foundation of China under Grants No 11075183.
文摘Neutral beam injection is recognized as one of the most effective means for plasma heating.The preliminary data of ion beam extraction is obtained on the EAST neutral beam injector test-stand.Beam extraction from the ion source of EAST-NBI is verified by measuring the beam current with a Faraday cup and by analyzing the results obtained by means of water calorimetric measurement on the temperature rises of water cooling the accelerator electrodes.
