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
Reconfigurable intelligent surface(RIS)is a novel meta-material which can form a smart radio environment by dynamically altering reflection directions of the impinging electromagnetic waves.In the prior literature,the...Reconfigurable intelligent surface(RIS)is a novel meta-material which can form a smart radio environment by dynamically altering reflection directions of the impinging electromagnetic waves.In the prior literature,the inter-RIS links which also contribute to the performance of the whole system are usually neglected when multiple RISs are deployed.In this paper we investigate a general double-RIS assisted multiple-input multiple-output(MIMO)wireless communication system under spatially correlated non line-of-sight propagation channels,where the cooperation of the double RISs is also considered.The design objective is to maximize the achievable ergodic rate based on full statistical channel state information(CSI).Specifically,we firstly present a closedform asymptotic expression for the achievable ergodic rate by utilizing replica method from statistical physics.Then a full statistical CSI-enabled optimal design is proposed which avoids high pilot training overhead compared to instantaneous CSI-enabled design.To further reduce the signal processing overhead and lower the complexity for practical realization,a common-phase scheme is proposed to design the double RISs.Simulation results show that the derived asymptotic ergodic rate is quite accurate even for small-sized antenna arrays.And the proposed optimization algorithm can achieve substantial gain at the expense of a low overhead and complexity.Furthermore,the cooperative double-RIS assisted MIMO framework is proven to achieve superior ergodic rate performance and high communication reliability under harsh propagation environment.展开更多
Ultralow frequency(ULF)pulsed-gradient magnetic field(with the maximum intensity of 0.6–2.0 T,gradient of 10–100 T·m^(-1),pulse width of 20–200 ms and frequency of 0.16–1.34 Hz)treatment of mice can inhibit m...Ultralow frequency(ULF)pulsed-gradient magnetic field(with the maximum intensity of 0.6–2.0 T,gradient of 10–100 T·m^(-1),pulse width of 20–200 ms and frequency of 0.16–1.34 Hz)treatment of mice can inhibit murine malignant tumour growth and can induce apoptosis of cancer cell.The apoptotic cancer cell contracted,became rounder and divorced from adjacent cells;the heterochromatin condensed and coagulated together along the inner side of the nuclear membrane;the endoplasmic reticulums expanded and fused with the cellular membrane;many apoptotic bodies which were packed by the cellular membrane appeared and were devoured by some lymphocytes and plasma.By Lorentz force the magnetic field keeps the moving ions within bounds of Larmor radius.Thus,penetrating capability of the positive and negative ions through the cell membrane was affected,even the role on the cell membrane formed.展开更多
EVs （electric vehicles） have been widely accepted as a promising solution for reducing oil consumption, air pollution and greenhouse gas emission. The number of EVs is growing very fast over the years. However, the ...EVs （electric vehicles） have been widely accepted as a promising solution for reducing oil consumption, air pollution and greenhouse gas emission. The number of EVs is growing very fast over the years. However, the high adoption of EVs will impose a burden on the power system, especially for neighborhood level network. In this paper, we propose a mixed control framework for EV charging scheduling to mitigate its impact on the power network. A metric for modeling customer＇s satisfaction is also proposed to compare the user satisfaction for different algorithms. The impacts of the proposed algorithms on EV charging cost, EV penetration and peak power reduction are evaluated with real data for a neighborhood level network. The simulation results demonstrate the effectiveness of the proposed algorithms.展开更多
To celebrate the scientific legacy and spirit of the late Dr.Brtton Chance(1913-2010)and his 100thbir thday,t he Brit ton Chance International Symposium on Metabolic Imaging and Spectroscopy was heldat the Perelman Sc...To celebrate the scientific legacy and spirit of the late Dr.Brtton Chance(1913-2010)and his 100thbir thday,t he Brit ton Chance International Symposium on Metabolic Imaging and Spectroscopy was heldat the Perelman School of Medicine,University of Pennsylvania on June 18-19th,2013.The symposium brought toget her over 200 physicists,engineers,biologists and clinicians from all over the world includingEurope,Asia and North America.The latest research innovations and clinical progresses by optical,nuclear magnetic resonance(NMR)and nuclear medicine methods were presented and discussed extensively.展开更多
In this paper,a coordinated control scheme for wind turbine generator(WTG)and supercapacitor energy storage system(ESS)is proposed for temporary frequency supports.Inertial control is designed by using generator torqu...In this paper,a coordinated control scheme for wind turbine generator(WTG)and supercapacitor energy storage system(ESS)is proposed for temporary frequency supports.Inertial control is designed by using generator torque limit considering the security of WTG system,while ESS releases its energy to compensate the sudden active power deficit during the recovery process of turbine rotor.WTG is modeled using the fatigue,aerodynamic,structure,turbulence(FAST)code,which identifies the mechanical loadings of the turbine and addresses electro-mechanical interactions in the wind energy system.A damping controller is augmented to the inertial control to suppress severe mechanical oscillations in the shaft and tower of the turbine during frequency supports.Furthermore,the result of small-signal stability analysis shows that the WTGESS tends to improve the stability of the whole multi-energy power grid.The major contributions of this paper will be validated by utilizing the proposed control method that combines the grid support capability and maintaining the integrity of structural design of the turbine for normal operations.展开更多
We introduce a novel method to accurately extract the optical parameters in terahertz reflection imaging. Our method builds on standard self-referencing methods using the reflected signal from the bottom of the imagin...We introduce a novel method to accurately extract the optical parameters in terahertz reflection imaging. Our method builds on standard self-referencing methods using the reflected signal from the bottom of the imaging window material to further compensate for time-dependent system fluctuations and position-dependent variation in the window thickness. Our proposed method not only improves the accuracy, but also simplifies the imaging procedure and reduces measurement times.展开更多
The mismatch between the AM1.5G spectrum and the photovoltaic (PV) cells absorption is one of the most limiting factors for PV performance.To overcome this constraint through the enhancement of solar energy harvesting...The mismatch between the AM1.5G spectrum and the photovoltaic (PV) cells absorption is one of the most limiting factors for PV performance.To overcome this constraint through the enhancement of solar energy harvesting,luminescent downshifting (LDS) layers are very promising to shape the incident sunlight and,thus,we report here the use of Tb^3+- and Eu^3+-doped organic-inorganic hybrid materials as LDS layers on Si PV cells.Electrical measurements on the PV cell,done before and after the deposition of the LDS layers,confirm the positive effect of the coatings on the cell’s performance in the UV spectral region.The maximum delivered power and the maximum absolute external quantum efficiency increased 14% and 27%,respectively.Moreover,a solar powered car race was organized in which the small vehicle containing the coated PV cells presented a relative increase of 9% in the velocity,when compared to that with the uncoated one.展开更多
In this study, a full-color emission red–green–blue(RGB) quantum-dot(QD)-based micro-light-emitting-diode(micro-LED) array with the reduced optical cross-talk effect by a photoresist mold has been demonstrated. The ...In this study, a full-color emission red–green–blue(RGB) quantum-dot(QD)-based micro-light-emitting-diode(micro-LED) array with the reduced optical cross-talk effect by a photoresist mold has been demonstrated. The UV micro-LED array is used as an efficient excitation source for the QDs. The aerosol jet technique provides a narrow linewidth on the micrometer scale for a precise jet of QDs on the micro-LEDs. To reduce the optical cross-talk effect,a simple lithography method and photoresist are used to fabricate the mold, which consists of a window for QD jetting and a blocking wall for cross-talk reduction. The cross-talk effect of the well-confined QDs in the window is confirmed by a fluorescence microscope, which shows clear separation between QD pixels. A distributed Bragg reflector is covered on the micro-LED array and the QDs' jetted mold to further increase the reuse of UV light.The enhanced light emission of the QDs is 5%, 32%, and 23% for blue, green, and red QDs, respectively.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supported in part by the Xi’an Jiaotong-Liverpool University(XJTLU)Research Development Fund(2024–2027)under Grant RDF-23-02-010supported in part by the Guangdong Basic and Applied Basic Research Foundation under Grant 2023A1515110732+5 种基金supported in part by the National Natural Science Foundation of China(NSFC)under Grant 62071247supported in part by the Science and Technology Development Fund,Macao,China SAR under Grants 0087/2022/AFJ and 001/2024/SKLin part by the National Natural Science Foundation of China under Grant 62261160650in part by the Research Committee of University of Macao,Macao SAR,China under Grants MYRG-GRG2023-00116-FST-UMDF and MYRG2020-00095-FSTsupported in part by the NSFC under Grant 62261160576 and 62301148in part by the Fundamental Research Funds for the Central Universities under Grant 2242023K5003.
文摘Reconfigurable intelligent surface(RIS)is a novel meta-material which can form a smart radio environment by dynamically altering reflection directions of the impinging electromagnetic waves.In the prior literature,the inter-RIS links which also contribute to the performance of the whole system are usually neglected when multiple RISs are deployed.In this paper we investigate a general double-RIS assisted multiple-input multiple-output(MIMO)wireless communication system under spatially correlated non line-of-sight propagation channels,where the cooperation of the double RISs is also considered.The design objective is to maximize the achievable ergodic rate based on full statistical channel state information(CSI).Specifically,we firstly present a closedform asymptotic expression for the achievable ergodic rate by utilizing replica method from statistical physics.Then a full statistical CSI-enabled optimal design is proposed which avoids high pilot training overhead compared to instantaneous CSI-enabled design.To further reduce the signal processing overhead and lower the complexity for practical realization,a common-phase scheme is proposed to design the double RISs.Simulation results show that the derived asymptotic ergodic rate is quite accurate even for small-sized antenna arrays.And the proposed optimization algorithm can achieve substantial gain at the expense of a low overhead and complexity.Furthermore,the cooperative double-RIS assisted MIMO framework is proven to achieve superior ergodic rate performance and high communication reliability under harsh propagation environment.
基金the National Natural Science Foundation of China(39870823)the Ministry of Science and Technology of China
文摘Ultralow frequency(ULF)pulsed-gradient magnetic field(with the maximum intensity of 0.6–2.0 T,gradient of 10–100 T·m^(-1),pulse width of 20–200 ms and frequency of 0.16–1.34 Hz)treatment of mice can inhibit murine malignant tumour growth and can induce apoptosis of cancer cell.The apoptotic cancer cell contracted,became rounder and divorced from adjacent cells;the heterochromatin condensed and coagulated together along the inner side of the nuclear membrane;the endoplasmic reticulums expanded and fused with the cellular membrane;many apoptotic bodies which were packed by the cellular membrane appeared and were devoured by some lymphocytes and plasma.By Lorentz force the magnetic field keeps the moving ions within bounds of Larmor radius.Thus,penetrating capability of the positive and negative ions through the cell membrane was affected,even the role on the cell membrane formed.
文摘EVs （electric vehicles） have been widely accepted as a promising solution for reducing oil consumption, air pollution and greenhouse gas emission. The number of EVs is growing very fast over the years. However, the high adoption of EVs will impose a burden on the power system, especially for neighborhood level network. In this paper, we propose a mixed control framework for EV charging scheduling to mitigate its impact on the power network. A metric for modeling customer＇s satisfaction is also proposed to compare the user satisfaction for different algorithms. The impacts of the proposed algorithms on EV charging cost, EV penetration and peak power reduction are evaluated with real data for a neighborhood level network. The simulation results demonstrate the effectiveness of the proposed algorithms.
文摘To celebrate the scientific legacy and spirit of the late Dr.Brtton Chance(1913-2010)and his 100thbir thday,t he Brit ton Chance International Symposium on Metabolic Imaging and Spectroscopy was heldat the Perelman School of Medicine,University of Pennsylvania on June 18-19th,2013.The symposium brought toget her over 200 physicists,engineers,biologists and clinicians from all over the world includingEurope,Asia and North America.The latest research innovations and clinical progresses by optical,nuclear magnetic resonance(NMR)and nuclear medicine methods were presented and discussed extensively.
基金supported by the U.S.National science foundation(No.1711951)
文摘In this paper,a coordinated control scheme for wind turbine generator(WTG)and supercapacitor energy storage system(ESS)is proposed for temporary frequency supports.Inertial control is designed by using generator torque limit considering the security of WTG system,while ESS releases its energy to compensate the sudden active power deficit during the recovery process of turbine rotor.WTG is modeled using the fatigue,aerodynamic,structure,turbulence(FAST)code,which identifies the mechanical loadings of the turbine and addresses electro-mechanical interactions in the wind energy system.A damping controller is augmented to the inertial control to suppress severe mechanical oscillations in the shaft and tower of the turbine during frequency supports.Furthermore,the result of small-signal stability analysis shows that the WTGESS tends to improve the stability of the whole multi-energy power grid.The major contributions of this paper will be validated by utilizing the proposed control method that combines the grid support capability and maintaining the integrity of structural design of the turbine for normal operations.
基金Research Grants Council of Hong Kong(415313,14205514)Direct Grant,Chinese University of Hong Kong
文摘We introduce a novel method to accurately extract the optical parameters in terahertz reflection imaging. Our method builds on standard self-referencing methods using the reflected signal from the bottom of the imaging window material to further compensate for time-dependent system fluctuations and position-dependent variation in the window thickness. Our proposed method not only improves the accuracy, but also simplifies the imaging procedure and reduces measurement times.
文摘The mismatch between the AM1.5G spectrum and the photovoltaic (PV) cells absorption is one of the most limiting factors for PV performance.To overcome this constraint through the enhancement of solar energy harvesting,luminescent downshifting (LDS) layers are very promising to shape the incident sunlight and,thus,we report here the use of Tb^3+- and Eu^3+-doped organic-inorganic hybrid materials as LDS layers on Si PV cells.Electrical measurements on the PV cell,done before and after the deposition of the LDS layers,confirm the positive effect of the coatings on the cell’s performance in the UV spectral region.The maximum delivered power and the maximum absolute external quantum efficiency increased 14% and 27%,respectively.Moreover,a solar powered car race was organized in which the small vehicle containing the coated PV cells presented a relative increase of 9% in the velocity,when compared to that with the uncoated one.
基金Ministry of Science and Technology,Taiwan,China(MOST)(MOST104-3113-E-009-002-CC2,MOST105-2622-E-009-023-CC2)
文摘In this study, a full-color emission red–green–blue(RGB) quantum-dot(QD)-based micro-light-emitting-diode(micro-LED) array with the reduced optical cross-talk effect by a photoresist mold has been demonstrated. The UV micro-LED array is used as an efficient excitation source for the QDs. The aerosol jet technique provides a narrow linewidth on the micrometer scale for a precise jet of QDs on the micro-LEDs. To reduce the optical cross-talk effect,a simple lithography method and photoresist are used to fabricate the mold, which consists of a window for QD jetting and a blocking wall for cross-talk reduction. The cross-talk effect of the well-confined QDs in the window is confirmed by a fluorescence microscope, which shows clear separation between QD pixels. A distributed Bragg reflector is covered on the micro-LED array and the QDs' jetted mold to further increase the reuse of UV light.The enhanced light emission of the QDs is 5%, 32%, and 23% for blue, green, and red QDs, respectively.
