The integration of digital twin(DT)and 6G edge intelligence provides accurate forecasting for distributed resources control in smart park.However,the adverse impact of model poisoning attacks on DT model training cann...The integration of digital twin(DT)and 6G edge intelligence provides accurate forecasting for distributed resources control in smart park.However,the adverse impact of model poisoning attacks on DT model training cannot be ignored.To address this issue,we firstly construct the models of DT model training and model poisoning attacks.An optimization problem is formulated to minimize the weighted sum of the DT loss function and DT model training delay.Then,the problem is transformed and solved by the proposed Multi-timescAle endogenouS securiTy-aware DQN-based rEsouRce management algorithm(MASTER)based on DT-assisted state information evaluation and attack detection.MASTER adopts multi-timescale deep Q-learning(DQN)networks to jointly schedule local training epochs and devices.It actively adjusts resource management strategies based on estimated attack probability to achieve endogenous security awareness.Simulation results demonstrate that MASTER has excellent performances in DT model training accuracy and delay.展开更多
The thermoelectric properties of layered Mo_(2)AB_(2)(A=S,Se,Te;B=Cl,Br,I)materials are systematically investigated by first-principles approach.Soft transverse acoustic modes and direct Mo d–Mo d couplings give rise...The thermoelectric properties of layered Mo_(2)AB_(2)(A=S,Se,Te;B=Cl,Br,I)materials are systematically investigated by first-principles approach.Soft transverse acoustic modes and direct Mo d–Mo d couplings give rise to strong anharmonicities and low lattice thermal conductivities.The double anions with distinctly different electronegativities of Mo_(2)AB_(2)monolayers can reduce the correlation between electron transport and phonon scattering,and further benefit much to their good thermoelectric properties.Thermoelectric properties of these Mo_(2)AB_(2)monolayers exhibit obvious anisotropies due to the direction-dependent chemical bondings and transport properties.Furthermore,their thermoelectric properties strongly depend on carrier type(n-type or p-type),carrier concentration and temperature.It is found that n-type Mo_(2)AB_(2)monolayers can be excellent thermoelectric materials with high electric conductivity,σ,and figures of merit,ZT.Choosing the types of A and B anions of Mo_(2)AB_(2)is an effective strategy to optimize their thermoelectric performance.These results provide rigorous understanding on thermoelectric properties of double-anions compounds and important guidance for achieving high thermoelectric performance in multi-anion compounds.展开更多
Multi-mode power internet of things(PIoT)combines various communication media to provide spatio-temporal coverage for low-carbon operation in smart park.Edge-end collaboration is feasible to achieve the full utilizati...Multi-mode power internet of things(PIoT)combines various communication media to provide spatio-temporal coverage for low-carbon operation in smart park.Edge-end collaboration is feasible to achieve the full utilization of heterogeneous resources and anti-eavesdropping.However,edge-end collaboration-based multi-mode PIoT faces challenges of mutual contradiction in communication and security quality of service(QoS)guarantee,inadaptability of resource management,and multi-mode access conflict.We propose an Adaptive learning based delAysensitive and seCure Edge-End Collaboration algorithm(ACE_(2))to optimize multi-mode channel selection and split device power into artificial noise(AN)transmission and data transmission for secure data delivery.ACE_(2) can achieve multi-attribute QoS guarantee,adaptive resource management and security enhancement,and access conflict elimination with the combined power of deep actor-critic(DAC),“win or learn fast(WoLF)”mechanism,and edge-end collaboration.Simulations demonstrate its superior performance in queuing delay,energy consumption,secrecy capacity,and adaptability to differentiated low-carbon services.展开更多
We demonstrate a single-chip silicon optical single sideband (OSSB) modulator composed of a radio frequenc(RF) branch line coupler (BLC) and a silicon dual-parallel Mach–Zehnder modulator (DP-MZM).A co-design between...We demonstrate a single-chip silicon optical single sideband (OSSB) modulator composed of a radio frequenc(RF) branch line coupler (BLC) and a silicon dual-parallel Mach–Zehnder modulator (DP-MZM).A co-design between the BLC and the DP-MZM is implemented to improve the sideband suppression ratio (SSR).The modu lator has a modulation efficiency of V_(π)L_(π)~1.75 V·cm and a 3 dB electro-optical (EO) bandwidth of 48.7 GHz The BLC can generate a pair of RF signals with equal amplitudes and orthogonal phases at the optimal frequenc of 21 GHz.We prove through theoretical calculation and experiment that,although the BLC’s performance in terms of power balance and phase orthogonality deteriorates in a wider frequency range,high SSRs can be realized by adjusting relevant bias phases of the DP-MZM.With this technique,the undesired sidebands are completel suppressed below the noise floor in the frequency range from 15 GHz to 30 GHz when the chip operates in the ful carrier OSSB (FC-OSSB) mode.In addition,an SSR>35 dB and an carrier suppression ratio (CSR)>42 dB ar demonstrated at 21 GHz in the suppressed carrier OSSB (SC-OSSB) mode.展开更多
基金supported by the Science and Technology Project of State Grid Corporation of China under Grant Number 52094021N010 (5400-202199534A-05-ZN)。
文摘The integration of digital twin(DT)and 6G edge intelligence provides accurate forecasting for distributed resources control in smart park.However,the adverse impact of model poisoning attacks on DT model training cannot be ignored.To address this issue,we firstly construct the models of DT model training and model poisoning attacks.An optimization problem is formulated to minimize the weighted sum of the DT loss function and DT model training delay.Then,the problem is transformed and solved by the proposed Multi-timescAle endogenouS securiTy-aware DQN-based rEsouRce management algorithm(MASTER)based on DT-assisted state information evaluation and attack detection.MASTER adopts multi-timescale deep Q-learning(DQN)networks to jointly schedule local training epochs and devices.It actively adjusts resource management strategies based on estimated attack probability to achieve endogenous security awareness.Simulation results demonstrate that MASTER has excellent performances in DT model training accuracy and delay.
基金Project supported by the Science and Technology Program of Guangzhou City(Grant Nos.202102020389 and 202103030001)the Fund of Guangdong Provincial Key Laboratory of Information Photonics Technology(Grant No.2020B121201011)the National Natural Science Foundation of China(Grant Nos.11804058 and 12064027)。
文摘The thermoelectric properties of layered Mo_(2)AB_(2)(A=S,Se,Te;B=Cl,Br,I)materials are systematically investigated by first-principles approach.Soft transverse acoustic modes and direct Mo d–Mo d couplings give rise to strong anharmonicities and low lattice thermal conductivities.The double anions with distinctly different electronegativities of Mo_(2)AB_(2)monolayers can reduce the correlation between electron transport and phonon scattering,and further benefit much to their good thermoelectric properties.Thermoelectric properties of these Mo_(2)AB_(2)monolayers exhibit obvious anisotropies due to the direction-dependent chemical bondings and transport properties.Furthermore,their thermoelectric properties strongly depend on carrier type(n-type or p-type),carrier concentration and temperature.It is found that n-type Mo_(2)AB_(2)monolayers can be excellent thermoelectric materials with high electric conductivity,σ,and figures of merit,ZT.Choosing the types of A and B anions of Mo_(2)AB_(2)is an effective strategy to optimize their thermoelectric performance.These results provide rigorous understanding on thermoelectric properties of double-anions compounds and important guidance for achieving high thermoelectric performance in multi-anion compounds.
基金supported by the Science and Technology Project of State Grid Corporation of China under Grant Number 52094021N010 (5400202199534A-0-5-ZN)
文摘Multi-mode power internet of things(PIoT)combines various communication media to provide spatio-temporal coverage for low-carbon operation in smart park.Edge-end collaboration is feasible to achieve the full utilization of heterogeneous resources and anti-eavesdropping.However,edge-end collaboration-based multi-mode PIoT faces challenges of mutual contradiction in communication and security quality of service(QoS)guarantee,inadaptability of resource management,and multi-mode access conflict.We propose an Adaptive learning based delAysensitive and seCure Edge-End Collaboration algorithm(ACE_(2))to optimize multi-mode channel selection and split device power into artificial noise(AN)transmission and data transmission for secure data delivery.ACE_(2) can achieve multi-attribute QoS guarantee,adaptive resource management and security enhancement,and access conflict elimination with the combined power of deep actor-critic(DAC),“win or learn fast(WoLF)”mechanism,and edge-end collaboration.Simulations demonstrate its superior performance in queuing delay,energy consumption,secrecy capacity,and adaptability to differentiated low-carbon services.
基金National Key Research and Development Program of China(2021YFB2800500)Scientific Project of Zhejiang Laboratory(2020LC0AD02)+1 种基金Science and Technology Program of Zhejiang Province(2022C01108)Science and Technology Innovation 2025 Major Project of Ningbo(2020Z021)
文摘We demonstrate a single-chip silicon optical single sideband (OSSB) modulator composed of a radio frequenc(RF) branch line coupler (BLC) and a silicon dual-parallel Mach–Zehnder modulator (DP-MZM).A co-design between the BLC and the DP-MZM is implemented to improve the sideband suppression ratio (SSR).The modu lator has a modulation efficiency of V_(π)L_(π)~1.75 V·cm and a 3 dB electro-optical (EO) bandwidth of 48.7 GHz The BLC can generate a pair of RF signals with equal amplitudes and orthogonal phases at the optimal frequenc of 21 GHz.We prove through theoretical calculation and experiment that,although the BLC’s performance in terms of power balance and phase orthogonality deteriorates in a wider frequency range,high SSRs can be realized by adjusting relevant bias phases of the DP-MZM.With this technique,the undesired sidebands are completel suppressed below the noise floor in the frequency range from 15 GHz to 30 GHz when the chip operates in the ful carrier OSSB (FC-OSSB) mode.In addition,an SSR>35 dB and an carrier suppression ratio (CSR)>42 dB ar demonstrated at 21 GHz in the suppressed carrier OSSB (SC-OSSB) mode.