This paper proposes a quantitative reconfigurability evaluation method for control systems with actuator saturation and additive faults from the perspective of system stability.Placing the saturated feedback law in th...This paper proposes a quantitative reconfigurability evaluation method for control systems with actuator saturation and additive faults from the perspective of system stability.Placing the saturated feedback law in the convex hull of a group of auxiliary linear controls,the sufficient reconfigurability conditions for the system under additive faults are derived using invariant sets.These conditions are then expressed as linear matrix inequalities(LMIs)and applied to quantify the degree of reconfigurability for the fault system.The largest fault magnitude for which the system can be stabilized,the largest initial state domain from which all the trajectories are convergent,and the minimum final state domain to which the trajectories will converge are investigated.The effectiveness of the proposed method is illustrated through an application example.展开更多
The shape of a spacecraft is transitioning from monolithic,manual,and static to modular,autonomous,and dynamic.Modular Reconfigurable Spacecrafts(MRSs)offer better solutions than traditional monolithic spacecrafts in ...The shape of a spacecraft is transitioning from monolithic,manual,and static to modular,autonomous,and dynamic.Modular Reconfigurable Spacecrafts(MRSs)offer better solutions than traditional monolithic spacecrafts in several aspects,and may become the next generation of spacecraft systems with efficient design,fast deployment,flexible application,and convenient management.This paper reviews the development and technology of MRS from three aspects:Modularity,reconfigurability,and autonomy.Despite the progress of research on MRS,there is still a lack of unified standards and little understanding of related concepts.Based on the understanding of basic concepts,the studies conducted on MRS are reviewed to identify technical requirements and solutions.Aiming at the future development trend of MRS,a novel modular selfreconfigurable spacecraft,referred to as MagicSat,is proposed.Furthermore,the MagicSat system composition,advantages,and application prospects are studied.The enabling technologies and major challenges of MRS are further analyzed in terms of modularization,integrated management,and self-reconfiguration technologies.Finally,the future development trend of MRS technology is predicted,and corresponding suggestions are provided.展开更多
The photonic frequency-interleaving(PFI)technique has shown great potential for broadband signal acquisition,effectively overcoming the challenges of clock jitter and channel mismatch in the conventional time-interlea...The photonic frequency-interleaving(PFI)technique has shown great potential for broadband signal acquisition,effectively overcoming the challenges of clock jitter and channel mismatch in the conventional time-interleaving paradigm.However,current comb-based PFI schemes have complex system architectures and face challenges in achieving large bandwidth,dense channelization,and flexible reconfigurability simultaneously,which impedes practical applications.In this work,we propose and demonstrate a broadband PFI scheme with high reconfigurability and scalability by exploiting multiple free-running lasers for dense spectral slicing with high crosstalk suppression.A dedicated system model is developed through a comprehensive analysis of the system non-idealities,and a cross-channel signal reconstruction algorithm is developed for distortion-free signal reconstruction,based on precise calibrations of intra-and inter-channel impairments.The system performance is validated through the reception of multi-format broadband signals,both digital and analog,with a detailed evaluation of signal reconstruction quality,achieving inter-channel phase differences of less than 2°.The reconfigurability and scalability of the scheme are demonstrated through a dual-band radar imaging experiment and a three-channel interleaving implementation with a maximum acquisition bandwidth of 4 GHz.To the best of our knowledge,this is the first demonstration of a practical radio-frequency(RF)application enabled by PFI.Our work provides an innovative solution for next-generation software-defined broadband RF receivers.展开更多
Unmanned Aerial Vehicle(UAV)-aided communication,prized for its network reconfigurability,operational flexibility,and cost-effectiveness,is a key enabler of the low-altitude economy.However,the high possibilities of l...Unmanned Aerial Vehicle(UAV)-aided communication,prized for its network reconfigurability,operational flexibility,and cost-effectiveness,is a key enabler of the low-altitude economy.However,the high possibilities of line-of-sight links and the broadcast nature of air-ground UAV communications make it vulnerable and prone to eavesdropping by malicious nodes.展开更多
In recent years,physical unclonable function(PUF)has emerged as a lightweight solution in the Internet of Things security.However,conventional PUFs based on complementary metal oxide semiconductor(CMOS)present challen...In recent years,physical unclonable function(PUF)has emerged as a lightweight solution in the Internet of Things security.However,conventional PUFs based on complementary metal oxide semiconductor(CMOS)present challenges such as insufficient randomness,significant power and area overhead,and vulnerability to environmental factors,leading to reduced reliability.In this study,we realize a strong,highly reliable and reconfigurable PUF with resistance against machine-learning attacks in a 1 kb spinorbit torque magnetic random access memory fabricated using a 180 nm CMOS process.This strong PUF achieves a challenge-response pair capacity of 10^(9) through a computing-in-memory approach.The results demonstrate that the proposed PUF exhibits near-ideal performance metrics:50.07% uniformity,50% diffuseness,49.89% uniqueness,and a bit error rate of 0%,even in a 375 K environment.The reconfigurability of PUF is demonstrated by a reconfigurable Hamming distance of 49.31% and a correlation coefficient of less than 0.2,making it difficult to extract output keys through side-channel analysis.Furthermore,resistance to machine-learning modeling attacks is confirmed by achieving an ideal accuracy prediction of approximately 50% in the test set.展开更多
In this data explosion era,ensuring the secure storage,access,and transmission of information is imperative,encom-passing all aspects ranging from safeguarding personal devices to formulating national information secu...In this data explosion era,ensuring the secure storage,access,and transmission of information is imperative,encom-passing all aspects ranging from safeguarding personal devices to formulating national information security strategies.Leverag-ing the potential offered by dual-type carriers for transportation and employing optical modulation techniques to develop high reconfigurable ambipolar optoelectronic transistors enables effective implementation of information destruction after read-ing,thereby guaranteeing data security.In this study,a reconfigurable ambipolar optoelectronic synaptic transistor based on poly(3-hexylthiophene)(P3HT)and poly[[N,N-bis(2-octyldodecyl)-napthalene-1,4,5,8-bis(dicarboximide)-2,6-diyl]-alt-5,5′-(2,2′-bithiophene)](N2200)blend film was fabricated through solution-processed method.The resulting transistor exhib-ited a relatively large ON/OFF ratio of 10^(3) in both n-and p-type regions,and tunable photoconductivity after light illumination,particularly with green light.The photo-generated carriers could be effectively trapped under the gate bias,indicating its poten-tial application in mimicking synaptic behaviors.Furthermore,the synaptic plasticity,including volatile/non-volatile and excita-tory/inhibitory characteristics,could be finely modulated by electrical and optical stimuli.These optoelectronic reconfigurable properties enable the realization of information light assisted burn after reading.This study not only offers valuable insights for the advancement of high-performance ambipolar organic optoelectronic synaptic transistors but also presents innovative ideas for the future information security access systems.展开更多
The 6G smart Fog Radio Access Network(F-RAN)is an integration of 6G network intelligence technologies and the F-RAN architecture.Its aim is to provide low-latency and high-performance services for massive access devic...The 6G smart Fog Radio Access Network(F-RAN)is an integration of 6G network intelligence technologies and the F-RAN architecture.Its aim is to provide low-latency and high-performance services for massive access devices.However,the performance of current 6G network intelligence technologies and its level of integration with the architecture,along with the system-level requirements for the number of access devices and limitations on energy consumption,have impeded further improvements in the 6G smart F-RAN.To better analyze the root causes of the network problems and promote the practical development of the network,this study used structured methods such as segmentation to conduct a review of the topic.The research results reveal that there are still many problems in the current 6G smart F-RAN.Future research directions and difficulties are also discussed.展开更多
Interference significantly impacts the performance of the Global Navigation Satellite Systems(GNSS),highlighting the need for advanced interference localization technology to bolster anti-interference and defense capa...Interference significantly impacts the performance of the Global Navigation Satellite Systems(GNSS),highlighting the need for advanced interference localization technology to bolster anti-interference and defense capabilities.The Uniform Circular Array(UCA)enables concurrent estimation of the Direction of Arrival(DOA)in both azimuth and elevation.Given the paramount importance of stability and real-time performance in interference localization,this work proposes an innovative approach to reduce the complexity and increase the robustness of the DOA estimation.The proposed method reduces computational complexity by selecting a reduced number of array elements to reconstruct a non-uniform sparse array from a UCA.To ensure DOA estimation accuracy,minimizing the Cramér-Rao Bound(CRB)is the objective,and the Spatial Correlation Coefficient(SCC)is incorporated as a constraint to mitigate side-lobe.The optimization model is a quadratic fractional model,which is solved by Semi-Definite Relaxation(SDR).When the array has perturbations,the mathematical expressions for CRB and SCC are re-derived to enhance the robustness of the reconstructed array.Simulation and hardware experiments validate the effectiveness of the proposed method in estimating interference DOA,showing high robustness and reductions in hardware and computational costs associated with DOA estimation.展开更多
This work focuses on maximizing the minimum user’s security energy efficiency(SEE)in an unmanned aerial vehicle-mounted reconfigurable intelligent surface(UAV-RIS)enhanced short-packet communication(SPC)system.The ba...This work focuses on maximizing the minimum user’s security energy efficiency(SEE)in an unmanned aerial vehicle-mounted reconfigurable intelligent surface(UAV-RIS)enhanced short-packet communication(SPC)system.The base station(BS)provides short packet services to ground users using the non-orthogonal multiple access(NOMA)protocol through UAV-RIS,while preventing eavesdropper attacks.To optimize SEE,a joint optimization is performed concerning power allocation,UAV position,decoding order,and RIS phase shifts.An iterative algorithm based on block coordinate descent is proposed for mixed-integer non-convex SEE optimization problem.The original problem is decomposed into three sub-problems,solved alternately using successive convex approximation(SCA),quadratic transformation,penalty function,and semi-definite programming(SDP).Simulation results demonstrate the performance of the UAV-RIS-enhanced short-packet system under different parameters and verify the algorithm’s convergence.Compared to benchmark schemes such as orthogonal multiple access,long packet communication,and sum SEE,the proposed UAV-RIS-enhanced short-packet scheme achieves the higher minimum user’s SEE.展开更多
The simultaneous transmitting and reflecting reconfigurable intelligent surface(STAR-RIS)can independently adjust surface’s reflection and transmission coefficients so as to enhance space coverage.For a multiple-inpu...The simultaneous transmitting and reflecting reconfigurable intelligent surface(STAR-RIS)can independently adjust surface’s reflection and transmission coefficients so as to enhance space coverage.For a multiple-input multiple-output(MIMO)communication system with a STAR-RIS,a base station(BS),an eavesdropper,and multiple users,the system security rate is studied.A joint design of the power allocation at the transmitter and phase shift matrices for reflection and transmission at the STAR-RIS is conducted,in order to maximize the worst achievable security data rate(ASDR).Since the problem is nonconvex and hence challenging,a particle swarm optimization(PSO)based algorithm is developed to tackle the problem.Both the cases of continuous and discrete phase shift matrices at the STAR-RIS are considered.Simulation results demonstrate the effectiveness of the proposed algorithm and shows the benefits of using STAR-RIS in MIMO mutliuser systems.展开更多
With the rapid development of holographic technology,metasurface-based holographic communication schemes have demonstrated immense potential for electromagnetic(EM)multifunctionality.However,traditional passive metasu...With the rapid development of holographic technology,metasurface-based holographic communication schemes have demonstrated immense potential for electromagnetic(EM)multifunctionality.However,traditional passive metasurfaces are severely limited by their lack of reconfigurability,hindering the realization of versatile holographic applications.Origami,an art form that mechanically induces spatial deformations,serves as a platform for multifunctional devices and has garnered significant attention in optics,physics,and materials science.The Miura-ori folding paradigm,characterized by its continuous reconfigurability in folded states,remains unexplored in the context of holographic imaging.Herein,we integrate the principles of Rosenfeld with L-and D-metal chiral enantiomers on a Miura-ori surface to tailor the aperture distribution.Leveraging the continuously tunable nature of the Miura-ori's folded states,the chiral response of the metallic structures varies across different folding configurations,enabling distinct EM holographic imaging functionalities.In the planar state,holographic encryption is achieved.Under specific folding conditions and driven by spin circularly polarized(CP)waves at a particular frequency,multiplexed holographic images can be reconstructed on designated focal planes with CP selectivity.Notably,the fabricated origami metasurface exhibits a large negative Poisson ratio,facilitating portability and deployment and offering novel avenues for spin-selective systems,camouflage,and information encryption.展开更多
Cable-driven parallel robots(CDPRs)have advantages of larger workspace and load capacity than conventional parallel robots while existing interference problems among cables,workpieces and the end-effector.In order to ...Cable-driven parallel robots(CDPRs)have advantages of larger workspace and load capacity than conventional parallel robots while existing interference problems among cables,workpieces and the end-effector.In order to avoid collision and improve the flexibility of the robots,this study proposes a reconfigurable cable-driven parallel robot(RCDPR)having characteristics of large load-to-weight ratio,easy modularity and variable stiffness.Adjustable brackets are connected to the moving platform to adjust the position of the pull-out point with the movement of the end-effector.In addition,a variable stiffness actuator(VSA)accompanied by finite element analysis is designed to optimize the cable tension to adapt different task requirements.Firstly,a new idea of reconfiguration is given,and an inverse kinematic model is established using the vector closure principle to derive its inverse kinematic expressions focusing on one of the configurations.Second,the VSA is attached to each cable to achieve stiffness adjustment,and the system stiffness is derived in detail.Finally,the rationality and accuracy of the robot are verified through numerical analysis,providing a reference for subsequent trajectory planning with implications.展开更多
With the growing demand for compute-intensive applications such as artificial intelligence(AI)and video processing,traditional reconfigurable array processors fail to meet the requirements of high-performance computin...With the growing demand for compute-intensive applications such as artificial intelligence(AI)and video processing,traditional reconfigurable array processors fail to meet the requirements of high-performance computing and related domains,primarily due to their high power consumption and low energy efficiency.To address this limitation,this paper proposes an accuracy-adaptive approxi-mate reconfigurable array architecture featuring preset dual thresholds and support for four computa-tional accuracy levels,enabling flexible adaptation to diverse application needs.The architecture in-tegrates a self-adaptive mechanism that dynamically adjusts computational precision based on real-time error threshold feedback.To evaluate the proposed architecture,the you only look once version 5(YOLOv5)deep neural network algorithm is parallelized and deployed on the approximate recon-figurable array.Experimental results demonstrate that the architecture achieves an 18.93%reduc-tion in power consumption compared with conventional reconfigurable structures operating in full-pre-cision mode.Additionally,the design exhibits superior energy efficiency and reduced computational resource utilization,thereby significantly enhancing the overall performance and applicability of reconfigurable array processors in power-sensitive scenarios.展开更多
A polarization converter with broadband polarization characteristics and capable of dynamic reconfiguration is proposed.By introducing out-of-plane degrees of freedom,dynamically tunable broadband and high-efficiency ...A polarization converter with broadband polarization characteristics and capable of dynamic reconfiguration is proposed.By introducing out-of-plane degrees of freedom,dynamically tunable broadband and high-efficiency linear polarization conversion within the wavelength range of 2000-2800 nm is achieved.Research results indicate that when a two-dimensional(2D)split-ring resonator(SRR)is irradiated by a low-dose focused ion beam,it will deform upward and transform into a three-dimensional(3D)SRR,achieving a linear polarization conversion efficiency of over 90%.The 3D SRR can be driven by electrostatic force to return to the 2D SRR state,thereby realizing the dynamic reconfiguration of this polarization converter.By changing the applied voltage and adjusting the structural parameters,a tailored polarization converter that exhibits broadband performance and high polarization conversion efficiency is also achieved.The results may provide novel ideas and technical methodologies for various applications such as polarized optical imaging,emerging display technologies,polarized optical communication,and optical sensing.展开更多
Mechanical metamaterials are artificial materials that control their macroscopic properties using repetitive units rather than chemical constituents.Through rational design and spatial arrangement of the unit cells,me...Mechanical metamaterials are artificial materials that control their macroscopic properties using repetitive units rather than chemical constituents.Through rational design and spatial arrangement of the unit cells,mechanical metamaterials can realize a range of counterintuitive properties on a larger scale.In this work,a type of mechanical metamaterial unit cell is proposed,exhibiting both compression-twist coupling behavior and bistability that can be programmed.The design involves linking two cylindrical frames with topology-designed inclined beams.Under uniaxial loading,the structure undergoes a compression-twist deformation,along with buckling at two joints of the inclined beams.Through a rational design of the unit's geometric parameters,the structure can retain its deformed state once the applied displacement surpasses a specified threshold,showing a programmed bistable characteristic.We investigated the influence of the involved parameters on the mechanical response of the unit cells numerically,which agrees well with our experimental results.Since the inclined beams dominate the elastic deformation of unit cells,the two cylindrical frames are almost independent of the bistable response and can therefore be designed in any shape for various arrangements of unit cells in multi-dimensional space.展开更多
Progressing beyond the stowage and deployment of reflectors and designing for multiple deployed states result in reflector shape reconfiguration,thus allowing for new functions including radiation pattern reconfigurat...Progressing beyond the stowage and deployment of reflectors and designing for multiple deployed states result in reflector shape reconfiguration,thus allowing for new functions including radiation pattern reconfiguration,and is valuable for space applications such as satellite-based radar and communications.This paper introduces a concept for achieving the deployment and shape reconfiguration of a paraboloid reflector using a 7R-8R(revolute joint)truss network.By realizing reconfigurability mechanically,complex electronic systems such as phased arrays can be avoided,and adopting a single-degree-of-freedom(DOF)design further reduces the number of required actuators.The proposed reflector is axisymmetric and can be doubly curved.It comprises a flexible mesh surface supported by a rigid truss network constructed from 7R and 8R linkages.Approximation of multiple target surfaces is achieved by synthesizing the truss network dimensions using a multiobjective optimization approach.The non-dominated sorting genetic algorithm is used in conjunction with analytical dimension parameterization and forward kinematics computation to determine the optimal dimensions for the truss network.In the resulting designs,the reflector follows a single-DOF trajectory,on which it unfolds from a compact stowed bundle toward a deployed state approximating a doubly curved target surface,then onwards to additional deployed states approximating different target surfaces.Design studies are conducted to demonstrate the reflector’s ability to approximate different target surfaces and continuously transform between such surfaces.This study proposes a new method for reconfiguring reflector shape mechanically,thus uniquely reconfiguring the shape of a doubly curved surface and achieving both deployment and shape reconfiguration under a unified single-DOF motion.展开更多
In this study,the potential application of shaped charge jets as transient antennas for electromagnetic signal transmission was explored and an electromagnetic pulse radiation system with a shaped charge jet as a tran...In this study,the potential application of shaped charge jets as transient antennas for electromagnetic signal transmission was explored and an electromagnetic pulse radiation system with a shaped charge jet as a transient antenna was proposed.During the research,crucial characteristics of the transient antenna formed by a shaped charge with a 30 mm diameter,such as resonant frequency,radiation pattern,and radiation efficiency,were evaluated.The typical shaped charge jet morphology was obtained based on the simulations,in which it could insight the dynamic behavior of the shaped charge jet selected.An equivalent model experiment was employed to test the radiation efficiency,and it showed that a shorting pin loading method could increase the relative bandwidth of the jet antenna to 32.8%,and the experimental results correlate with the theoretical predictions for half-wave dipole antennas reasonably well.Additionally,variations in the diameter of the shaped charge jet were found to affect the input impedance and impedance bandwidth,while the length of the jet influenced the resonant frequency of the antenna.This suggests that altering these parameters can achieve reconfigurability of the jet antenna.展开更多
Reconfiguration,as well as optimal utilization of distributed generation sources and capacitor banks,are highly effective methods for reducing losses and improving the voltage profile,or in other words,the power quali...Reconfiguration,as well as optimal utilization of distributed generation sources and capacitor banks,are highly effective methods for reducing losses and improving the voltage profile,or in other words,the power quality in the power distribution system.Researchers have considered the use of distributed generation resources in recent years.There are numerous advantages to utilizing these resources,the most significant of which are the reduction of network losses and enhancement of voltage stability.Non-dominated Sorting Genetic Algorithm II(NSGA-II),Multi-Objective Particle Swarm Optimization(MOPSO),and Intersect Mutation Differential Evolution(IMDE)algorithms are used in this paper to perform optimal reconfiguration,simultaneous location,and capacity determination of distributed generation resources and capacitor banks.Three scenarios were used to replicate the studies.The reconfiguration of the switches,as well as the location and determination of the capacitor bank’s optimal capacity,were investigated in this scenario.However,in the third scenario,reconfiguration,and determining the location and capacity of the Distributed Generation(DG)resources and capacitor banks have been carried out simultaneously.Finally,the simulation results of these three algorithms are compared.The results indicate that the proposed NSGAII algorithm outperformed the other two multi-objective algorithms and was capable of maintaining smaller objective functions in all scenarios.Specifically,the energy losses were reduced from 211 to 51.35 kW(a 75.66%reduction),119.13 kW(a 43.54%reduction),and 23.13 kW(an 89.04%reduction),while the voltage stability index(VSI)decreased from 6.96 to 2.105,1.239,and 1.257,respectively,demonstrating significant improvement in the voltage profile.展开更多
The distribution networks sometimes suffer from excessive losses and voltage violations in densely populated areas. The aim of the present study is to improve the performance of a distribution network by successively ...The distribution networks sometimes suffer from excessive losses and voltage violations in densely populated areas. The aim of the present study is to improve the performance of a distribution network by successively applying mono-capacitor positioning, multiple positioning and reconfiguration processes using GA-based algorithms implemented in a Matlab environment. From the diagnostic study of this network, it was observed that a minimum voltage of 0.90 pu induces a voltage deviation of 5.26%, followed by active and reactive losses of 425.08 kW and 435.09 kVAR, respectively. Single placement with the NSGAII resulted in the placement of a 3000 kVAR capacitor at node 128, which proved to be the invariably neuralgic point. Multiple placements resulted in a 21.55% reduction in losses and a 0.74% regression in voltage profile performance. After topology optimization, the loss profile improved by 65.08% and the voltage profile improved by 1.05%. Genetic algorithms are efficient and effective tools for improving the performance of distribution networks, whose degradation is often dynamic due to the natural variability of loads.展开更多
This article presents a compact crab-shaped reconfigurable antenna(CSRA)designed for 5G sub-6 GHz wireless applications. The antenna achieves enhanced gain in a miniaturized form factor by incorporating a hexagonal sp...This article presents a compact crab-shaped reconfigurable antenna(CSRA)designed for 5G sub-6 GHz wireless applications. The antenna achieves enhanced gain in a miniaturized form factor by incorporating a hexagonal split-ring structure controlled via two radio frequency(RF) positive-intrinsicnegative(PIN) diodes(BAR64-02V). While the antenna is primarily designed to operate at 3.50 GHz for sub-6 GHz 5G applications, RF switching enables the CSRA to cover a broader frequency spectrum, including the S-band, X-band, and portions of the Ku-band. The proposed antenna offers several advantages: It is low-cost(fabricated on an FR-4 substrate), compact(achieving 64.07% size reduction compared to conventional designs), and features both frequency and gain reconfigurability through digitally controlled PIN diode switching. The reflection coefficients of the antenna, both without diodes and across all four switching states, were experimentally validated in the laboratory using a Keysight Field Fox microwave analyzer(N9916A, 14 GHz). The simulated radiation patterns and gain characteristics closely matched the measured values, demonstrating an excellent agreement. This study bridges the gap between traditional and next-generation antenna designs by offering a compact,cost-effective, and high-performance solution for multiband, reconfigurable wireless communication systems. The integration of double-split-ring resonators and dynamic reconfigurability makes the proposed antenna a strong candidate for various applications, including S-band and X-band systems, as well as the emerging lower 6G band(7.125 GHz–8.400 GHz).展开更多
基金This work was supported by the National Natural Science Funds for Distinguished Young Scholars of China(61525301)the National Natural Science Fund for Excellent Young Scholars of China(62022013)the National Natural Science Foundation of China(61690215).
文摘This paper proposes a quantitative reconfigurability evaluation method for control systems with actuator saturation and additive faults from the perspective of system stability.Placing the saturated feedback law in the convex hull of a group of auxiliary linear controls,the sufficient reconfigurability conditions for the system under additive faults are derived using invariant sets.These conditions are then expressed as linear matrix inequalities(LMIs)and applied to quantify the degree of reconfigurability for the fault system.The largest fault magnitude for which the system can be stabilized,the largest initial state domain from which all the trajectories are convergent,and the minimum final state domain to which the trajectories will converge are investigated.The effectiveness of the proposed method is illustrated through an application example.
基金supported by the National Defense Science and Technology Innovation Zone of China(No.00205501).
文摘The shape of a spacecraft is transitioning from monolithic,manual,and static to modular,autonomous,and dynamic.Modular Reconfigurable Spacecrafts(MRSs)offer better solutions than traditional monolithic spacecrafts in several aspects,and may become the next generation of spacecraft systems with efficient design,fast deployment,flexible application,and convenient management.This paper reviews the development and technology of MRS from three aspects:Modularity,reconfigurability,and autonomy.Despite the progress of research on MRS,there is still a lack of unified standards and little understanding of related concepts.Based on the understanding of basic concepts,the studies conducted on MRS are reviewed to identify technical requirements and solutions.Aiming at the future development trend of MRS,a novel modular selfreconfigurable spacecraft,referred to as MagicSat,is proposed.Furthermore,the MagicSat system composition,advantages,and application prospects are studied.The enabling technologies and major challenges of MRS are further analyzed in terms of modularization,integrated management,and self-reconfiguration technologies.Finally,the future development trend of MRS technology is predicted,and corresponding suggestions are provided.
基金National Key Research and Development Program of China(2021YFB2800800)National Key Laboratory Program(E13D01012F)+4 种基金National Natural Science Foundation of China(62104232,62327806,61988102)Key Research Program of Frontier Sciences,CAS(ZDBS-LYJSC016)Guangdong Province Key Field RD Program Project(2020B0101110002)Science and Technology Planning Project of Guangdong Province(2019B090909011)Program of GBA Branch of AIRCAS(E0Z2D10600)。
文摘The photonic frequency-interleaving(PFI)technique has shown great potential for broadband signal acquisition,effectively overcoming the challenges of clock jitter and channel mismatch in the conventional time-interleaving paradigm.However,current comb-based PFI schemes have complex system architectures and face challenges in achieving large bandwidth,dense channelization,and flexible reconfigurability simultaneously,which impedes practical applications.In this work,we propose and demonstrate a broadband PFI scheme with high reconfigurability and scalability by exploiting multiple free-running lasers for dense spectral slicing with high crosstalk suppression.A dedicated system model is developed through a comprehensive analysis of the system non-idealities,and a cross-channel signal reconstruction algorithm is developed for distortion-free signal reconstruction,based on precise calibrations of intra-and inter-channel impairments.The system performance is validated through the reception of multi-format broadband signals,both digital and analog,with a detailed evaluation of signal reconstruction quality,achieving inter-channel phase differences of less than 2°.The reconfigurability and scalability of the scheme are demonstrated through a dual-band radar imaging experiment and a three-channel interleaving implementation with a maximum acquisition bandwidth of 4 GHz.To the best of our knowledge,this is the first demonstration of a practical radio-frequency(RF)application enabled by PFI.Our work provides an innovative solution for next-generation software-defined broadband RF receivers.
文摘Unmanned Aerial Vehicle(UAV)-aided communication,prized for its network reconfigurability,operational flexibility,and cost-effectiveness,is a key enabler of the low-altitude economy.However,the high possibilities of line-of-sight links and the broadcast nature of air-ground UAV communications make it vulnerable and prone to eavesdropping by malicious nodes.
基金supported by the National Natural Science Foundation of China(92164206,52261145694,T2394474,T2394470,623B2015,62271026,62401026,and 62404013)the National Key Research and Development Program of China(2022YFB4400200)+1 种基金the New Cornerstone Science Foundation through the XPLORER PRIZE,the National Postdoctoral Program for Innovative Talents(BX20220374 and BX20240455)the China Postdoctoral Science Foundation Funded Project(2023M740177 and 2022M720345).
文摘In recent years,physical unclonable function(PUF)has emerged as a lightweight solution in the Internet of Things security.However,conventional PUFs based on complementary metal oxide semiconductor(CMOS)present challenges such as insufficient randomness,significant power and area overhead,and vulnerability to environmental factors,leading to reduced reliability.In this study,we realize a strong,highly reliable and reconfigurable PUF with resistance against machine-learning attacks in a 1 kb spinorbit torque magnetic random access memory fabricated using a 180 nm CMOS process.This strong PUF achieves a challenge-response pair capacity of 10^(9) through a computing-in-memory approach.The results demonstrate that the proposed PUF exhibits near-ideal performance metrics:50.07% uniformity,50% diffuseness,49.89% uniqueness,and a bit error rate of 0%,even in a 375 K environment.The reconfigurability of PUF is demonstrated by a reconfigurable Hamming distance of 49.31% and a correlation coefficient of less than 0.2,making it difficult to extract output keys through side-channel analysis.Furthermore,resistance to machine-learning modeling attacks is confirmed by achieving an ideal accuracy prediction of approximately 50% in the test set.
基金the National Natural-Science Foundation of China(Grant No.62304137)Guangdong Basic and Applied Basic Research Foundation(Grant Nos.2023A1515012479,2024A1515011737,and 2024A1515010006)+4 种基金the Science and Technology Innovation Commission of Shenzhen(Grant No.JCYJ20220818100206013)RSC Researcher Collaborations Grant(Grant No.C23-2422436283)State Key Laboratory of Radio Frequency Heterogeneous Integration(Independent Scientific Research Program No.2024010)the Project on Frontier and Interdisciplinary Research Assessment,Academic Divisions of the Chinese Academy of Sciences(Grant No.XK2023XXA002)NTUT-SZU Joint Research Program.
文摘In this data explosion era,ensuring the secure storage,access,and transmission of information is imperative,encom-passing all aspects ranging from safeguarding personal devices to formulating national information security strategies.Leverag-ing the potential offered by dual-type carriers for transportation and employing optical modulation techniques to develop high reconfigurable ambipolar optoelectronic transistors enables effective implementation of information destruction after read-ing,thereby guaranteeing data security.In this study,a reconfigurable ambipolar optoelectronic synaptic transistor based on poly(3-hexylthiophene)(P3HT)and poly[[N,N-bis(2-octyldodecyl)-napthalene-1,4,5,8-bis(dicarboximide)-2,6-diyl]-alt-5,5′-(2,2′-bithiophene)](N2200)blend film was fabricated through solution-processed method.The resulting transistor exhib-ited a relatively large ON/OFF ratio of 10^(3) in both n-and p-type regions,and tunable photoconductivity after light illumination,particularly with green light.The photo-generated carriers could be effectively trapped under the gate bias,indicating its poten-tial application in mimicking synaptic behaviors.Furthermore,the synaptic plasticity,including volatile/non-volatile and excita-tory/inhibitory characteristics,could be finely modulated by electrical and optical stimuli.These optoelectronic reconfigurable properties enable the realization of information light assisted burn after reading.This study not only offers valuable insights for the advancement of high-performance ambipolar organic optoelectronic synaptic transistors but also presents innovative ideas for the future information security access systems.
基金supported by the National Natural Science Foundation of China(62202215)Liaoning Province Applied Basic Research Program(Youth Special Project,2023JH2/101600038)+2 种基金Shenyang Youth Science and Technology Innovation Talent Support Program(RC220458)Guangxuan Program of Shenyang Ligong University(SYLUGXRC202216)Basic Research Special Funds for Undergraduate Universities in Liaoning Province(LJ212410144067).
文摘The 6G smart Fog Radio Access Network(F-RAN)is an integration of 6G network intelligence technologies and the F-RAN architecture.Its aim is to provide low-latency and high-performance services for massive access devices.However,the performance of current 6G network intelligence technologies and its level of integration with the architecture,along with the system-level requirements for the number of access devices and limitations on energy consumption,have impeded further improvements in the 6G smart F-RAN.To better analyze the root causes of the network problems and promote the practical development of the network,this study used structured methods such as segmentation to conduct a review of the topic.The research results reveal that there are still many problems in the current 6G smart F-RAN.Future research directions and difficulties are also discussed.
基金the financial support from the National Key Research and Development Program of China(No.2023YFB3907001)the National Natural Science Foundation of China(Nos.U2233217,62371029)the UK Engineering and Physical Sciences Research Council(EPSRC),China(Nos.EP/M026981/1,EP/T021063/1 and EP/T024917/)。
文摘Interference significantly impacts the performance of the Global Navigation Satellite Systems(GNSS),highlighting the need for advanced interference localization technology to bolster anti-interference and defense capabilities.The Uniform Circular Array(UCA)enables concurrent estimation of the Direction of Arrival(DOA)in both azimuth and elevation.Given the paramount importance of stability and real-time performance in interference localization,this work proposes an innovative approach to reduce the complexity and increase the robustness of the DOA estimation.The proposed method reduces computational complexity by selecting a reduced number of array elements to reconstruct a non-uniform sparse array from a UCA.To ensure DOA estimation accuracy,minimizing the Cramér-Rao Bound(CRB)is the objective,and the Spatial Correlation Coefficient(SCC)is incorporated as a constraint to mitigate side-lobe.The optimization model is a quadratic fractional model,which is solved by Semi-Definite Relaxation(SDR).When the array has perturbations,the mathematical expressions for CRB and SCC are re-derived to enhance the robustness of the reconstructed array.Simulation and hardware experiments validate the effectiveness of the proposed method in estimating interference DOA,showing high robustness and reductions in hardware and computational costs associated with DOA estimation.
基金co-supported by the National Natural Science Foundation of China(Nos.U23A20279,62271094)the National Key R&D Program of China(No.SQ2023YFB2500024)+2 种基金the Science Foundation for Youths of Natural Science Foundation of Sichuan Provincial,China(No.2022NSFSC0936)the China Postdoctoral Science Foundation(No.2022M720666)the Open Fund of Key Laboratory of Big Data Intelligent Computing,Chongqing University of Posts and Telecommunications,China(No.BDIC-2023-B-002).
文摘This work focuses on maximizing the minimum user’s security energy efficiency(SEE)in an unmanned aerial vehicle-mounted reconfigurable intelligent surface(UAV-RIS)enhanced short-packet communication(SPC)system.The base station(BS)provides short packet services to ground users using the non-orthogonal multiple access(NOMA)protocol through UAV-RIS,while preventing eavesdropper attacks.To optimize SEE,a joint optimization is performed concerning power allocation,UAV position,decoding order,and RIS phase shifts.An iterative algorithm based on block coordinate descent is proposed for mixed-integer non-convex SEE optimization problem.The original problem is decomposed into three sub-problems,solved alternately using successive convex approximation(SCA),quadratic transformation,penalty function,and semi-definite programming(SDP).Simulation results demonstrate the performance of the UAV-RIS-enhanced short-packet system under different parameters and verify the algorithm’s convergence.Compared to benchmark schemes such as orthogonal multiple access,long packet communication,and sum SEE,the proposed UAV-RIS-enhanced short-packet scheme achieves the higher minimum user’s SEE.
文摘The simultaneous transmitting and reflecting reconfigurable intelligent surface(STAR-RIS)can independently adjust surface’s reflection and transmission coefficients so as to enhance space coverage.For a multiple-input multiple-output(MIMO)communication system with a STAR-RIS,a base station(BS),an eavesdropper,and multiple users,the system security rate is studied.A joint design of the power allocation at the transmitter and phase shift matrices for reflection and transmission at the STAR-RIS is conducted,in order to maximize the worst achievable security data rate(ASDR).Since the problem is nonconvex and hence challenging,a particle swarm optimization(PSO)based algorithm is developed to tackle the problem.Both the cases of continuous and discrete phase shift matrices at the STAR-RIS are considered.Simulation results demonstrate the effectiveness of the proposed algorithm and shows the benefits of using STAR-RIS in MIMO mutliuser systems.
基金financial supports from National Key Research and Development Program of China(No.2022YFB3806200)。
文摘With the rapid development of holographic technology,metasurface-based holographic communication schemes have demonstrated immense potential for electromagnetic(EM)multifunctionality.However,traditional passive metasurfaces are severely limited by their lack of reconfigurability,hindering the realization of versatile holographic applications.Origami,an art form that mechanically induces spatial deformations,serves as a platform for multifunctional devices and has garnered significant attention in optics,physics,and materials science.The Miura-ori folding paradigm,characterized by its continuous reconfigurability in folded states,remains unexplored in the context of holographic imaging.Herein,we integrate the principles of Rosenfeld with L-and D-metal chiral enantiomers on a Miura-ori surface to tailor the aperture distribution.Leveraging the continuously tunable nature of the Miura-ori's folded states,the chiral response of the metallic structures varies across different folding configurations,enabling distinct EM holographic imaging functionalities.In the planar state,holographic encryption is achieved.Under specific folding conditions and driven by spin circularly polarized(CP)waves at a particular frequency,multiplexed holographic images can be reconstructed on designated focal planes with CP selectivity.Notably,the fabricated origami metasurface exhibits a large negative Poisson ratio,facilitating portability and deployment and offering novel avenues for spin-selective systems,camouflage,and information encryption.
基金Supported by National Natural Science Foundation of China(Grant Nos.52335002,52205014,52275033)the Fundamental Research Funds for the Central Universities(Grant No.JZ2024HGTB0245).
文摘Cable-driven parallel robots(CDPRs)have advantages of larger workspace and load capacity than conventional parallel robots while existing interference problems among cables,workpieces and the end-effector.In order to avoid collision and improve the flexibility of the robots,this study proposes a reconfigurable cable-driven parallel robot(RCDPR)having characteristics of large load-to-weight ratio,easy modularity and variable stiffness.Adjustable brackets are connected to the moving platform to adjust the position of the pull-out point with the movement of the end-effector.In addition,a variable stiffness actuator(VSA)accompanied by finite element analysis is designed to optimize the cable tension to adapt different task requirements.Firstly,a new idea of reconfiguration is given,and an inverse kinematic model is established using the vector closure principle to derive its inverse kinematic expressions focusing on one of the configurations.Second,the VSA is attached to each cable to achieve stiffness adjustment,and the system stiffness is derived in detail.Finally,the rationality and accuracy of the robot are verified through numerical analysis,providing a reference for subsequent trajectory planning with implications.
基金Supported by the National Science and Technology Major Project(No.2022ZD0119001)the National Natural Science Foundation of China(No.61834005,61802304)the Key R&D Program Projects in Shaanxi Province(No.2024GX-YBXM-100).
文摘With the growing demand for compute-intensive applications such as artificial intelligence(AI)and video processing,traditional reconfigurable array processors fail to meet the requirements of high-performance computing and related domains,primarily due to their high power consumption and low energy efficiency.To address this limitation,this paper proposes an accuracy-adaptive approxi-mate reconfigurable array architecture featuring preset dual thresholds and support for four computa-tional accuracy levels,enabling flexible adaptation to diverse application needs.The architecture in-tegrates a self-adaptive mechanism that dynamically adjusts computational precision based on real-time error threshold feedback.To evaluate the proposed architecture,the you only look once version 5(YOLOv5)deep neural network algorithm is parallelized and deployed on the approximate recon-figurable array.Experimental results demonstrate that the architecture achieves an 18.93%reduc-tion in power consumption compared with conventional reconfigurable structures operating in full-pre-cision mode.Additionally,the design exhibits superior energy efficiency and reduced computational resource utilization,thereby significantly enhancing the overall performance and applicability of reconfigurable array processors in power-sensitive scenarios.
基金supported by the National Natural Science Foundation of China(Nos.T2325005,62375016,62475250)the Science and Technology Project of Guangdong(No.2020B010190001)。
文摘A polarization converter with broadband polarization characteristics and capable of dynamic reconfiguration is proposed.By introducing out-of-plane degrees of freedom,dynamically tunable broadband and high-efficiency linear polarization conversion within the wavelength range of 2000-2800 nm is achieved.Research results indicate that when a two-dimensional(2D)split-ring resonator(SRR)is irradiated by a low-dose focused ion beam,it will deform upward and transform into a three-dimensional(3D)SRR,achieving a linear polarization conversion efficiency of over 90%.The 3D SRR can be driven by electrostatic force to return to the 2D SRR state,thereby realizing the dynamic reconfiguration of this polarization converter.By changing the applied voltage and adjusting the structural parameters,a tailored polarization converter that exhibits broadband performance and high polarization conversion efficiency is also achieved.The results may provide novel ideas and technical methodologies for various applications such as polarized optical imaging,emerging display technologies,polarized optical communication,and optical sensing.
基金supported by the National Natural Science Foundation of China(Grant Numbers:12125205,12321002,12072316,12132014)the Zhejiang Provincial Natural Science Foundation of China(LD22A020001).
文摘Mechanical metamaterials are artificial materials that control their macroscopic properties using repetitive units rather than chemical constituents.Through rational design and spatial arrangement of the unit cells,mechanical metamaterials can realize a range of counterintuitive properties on a larger scale.In this work,a type of mechanical metamaterial unit cell is proposed,exhibiting both compression-twist coupling behavior and bistability that can be programmed.The design involves linking two cylindrical frames with topology-designed inclined beams.Under uniaxial loading,the structure undergoes a compression-twist deformation,along with buckling at two joints of the inclined beams.Through a rational design of the unit's geometric parameters,the structure can retain its deformed state once the applied displacement surpasses a specified threshold,showing a programmed bistable characteristic.We investigated the influence of the involved parameters on the mechanical response of the unit cells numerically,which agrees well with our experimental results.Since the inclined beams dominate the elastic deformation of unit cells,the two cylindrical frames are almost independent of the bistable response and can therefore be designed in any shape for various arrangements of unit cells in multi-dimensional space.
基金Supported by National Natural Science Foundation of China(Grant Nos.52320105005,52035008)the New Cornerstone Science Foundation through the Xplorer Prize(Grant No.XPLORER-2020-1035).
文摘Progressing beyond the stowage and deployment of reflectors and designing for multiple deployed states result in reflector shape reconfiguration,thus allowing for new functions including radiation pattern reconfiguration,and is valuable for space applications such as satellite-based radar and communications.This paper introduces a concept for achieving the deployment and shape reconfiguration of a paraboloid reflector using a 7R-8R(revolute joint)truss network.By realizing reconfigurability mechanically,complex electronic systems such as phased arrays can be avoided,and adopting a single-degree-of-freedom(DOF)design further reduces the number of required actuators.The proposed reflector is axisymmetric and can be doubly curved.It comprises a flexible mesh surface supported by a rigid truss network constructed from 7R and 8R linkages.Approximation of multiple target surfaces is achieved by synthesizing the truss network dimensions using a multiobjective optimization approach.The non-dominated sorting genetic algorithm is used in conjunction with analytical dimension parameterization and forward kinematics computation to determine the optimal dimensions for the truss network.In the resulting designs,the reflector follows a single-DOF trajectory,on which it unfolds from a compact stowed bundle toward a deployed state approximating a doubly curved target surface,then onwards to additional deployed states approximating different target surfaces.Design studies are conducted to demonstrate the reflector’s ability to approximate different target surfaces and continuously transform between such surfaces.This study proposes a new method for reconfiguring reflector shape mechanically,thus uniquely reconfiguring the shape of a doubly curved surface and achieving both deployment and shape reconfiguration under a unified single-DOF motion.
基金supported by the"Fundamental Research Funds for the Central Universities"(Grant No.30924010801).
文摘In this study,the potential application of shaped charge jets as transient antennas for electromagnetic signal transmission was explored and an electromagnetic pulse radiation system with a shaped charge jet as a transient antenna was proposed.During the research,crucial characteristics of the transient antenna formed by a shaped charge with a 30 mm diameter,such as resonant frequency,radiation pattern,and radiation efficiency,were evaluated.The typical shaped charge jet morphology was obtained based on the simulations,in which it could insight the dynamic behavior of the shaped charge jet selected.An equivalent model experiment was employed to test the radiation efficiency,and it showed that a shorting pin loading method could increase the relative bandwidth of the jet antenna to 32.8%,and the experimental results correlate with the theoretical predictions for half-wave dipole antennas reasonably well.Additionally,variations in the diameter of the shaped charge jet were found to affect the input impedance and impedance bandwidth,while the length of the jet influenced the resonant frequency of the antenna.This suggests that altering these parameters can achieve reconfigurability of the jet antenna.
文摘Reconfiguration,as well as optimal utilization of distributed generation sources and capacitor banks,are highly effective methods for reducing losses and improving the voltage profile,or in other words,the power quality in the power distribution system.Researchers have considered the use of distributed generation resources in recent years.There are numerous advantages to utilizing these resources,the most significant of which are the reduction of network losses and enhancement of voltage stability.Non-dominated Sorting Genetic Algorithm II(NSGA-II),Multi-Objective Particle Swarm Optimization(MOPSO),and Intersect Mutation Differential Evolution(IMDE)algorithms are used in this paper to perform optimal reconfiguration,simultaneous location,and capacity determination of distributed generation resources and capacitor banks.Three scenarios were used to replicate the studies.The reconfiguration of the switches,as well as the location and determination of the capacitor bank’s optimal capacity,were investigated in this scenario.However,in the third scenario,reconfiguration,and determining the location and capacity of the Distributed Generation(DG)resources and capacitor banks have been carried out simultaneously.Finally,the simulation results of these three algorithms are compared.The results indicate that the proposed NSGAII algorithm outperformed the other two multi-objective algorithms and was capable of maintaining smaller objective functions in all scenarios.Specifically,the energy losses were reduced from 211 to 51.35 kW(a 75.66%reduction),119.13 kW(a 43.54%reduction),and 23.13 kW(an 89.04%reduction),while the voltage stability index(VSI)decreased from 6.96 to 2.105,1.239,and 1.257,respectively,demonstrating significant improvement in the voltage profile.
文摘The distribution networks sometimes suffer from excessive losses and voltage violations in densely populated areas. The aim of the present study is to improve the performance of a distribution network by successively applying mono-capacitor positioning, multiple positioning and reconfiguration processes using GA-based algorithms implemented in a Matlab environment. From the diagnostic study of this network, it was observed that a minimum voltage of 0.90 pu induces a voltage deviation of 5.26%, followed by active and reactive losses of 425.08 kW and 435.09 kVAR, respectively. Single placement with the NSGAII resulted in the placement of a 3000 kVAR capacitor at node 128, which proved to be the invariably neuralgic point. Multiple placements resulted in a 21.55% reduction in losses and a 0.74% regression in voltage profile performance. After topology optimization, the loss profile improved by 65.08% and the voltage profile improved by 1.05%. Genetic algorithms are efficient and effective tools for improving the performance of distribution networks, whose degradation is often dynamic due to the natural variability of loads.
文摘This article presents a compact crab-shaped reconfigurable antenna(CSRA)designed for 5G sub-6 GHz wireless applications. The antenna achieves enhanced gain in a miniaturized form factor by incorporating a hexagonal split-ring structure controlled via two radio frequency(RF) positive-intrinsicnegative(PIN) diodes(BAR64-02V). While the antenna is primarily designed to operate at 3.50 GHz for sub-6 GHz 5G applications, RF switching enables the CSRA to cover a broader frequency spectrum, including the S-band, X-band, and portions of the Ku-band. The proposed antenna offers several advantages: It is low-cost(fabricated on an FR-4 substrate), compact(achieving 64.07% size reduction compared to conventional designs), and features both frequency and gain reconfigurability through digitally controlled PIN diode switching. The reflection coefficients of the antenna, both without diodes and across all four switching states, were experimentally validated in the laboratory using a Keysight Field Fox microwave analyzer(N9916A, 14 GHz). The simulated radiation patterns and gain characteristics closely matched the measured values, demonstrating an excellent agreement. This study bridges the gap between traditional and next-generation antenna designs by offering a compact,cost-effective, and high-performance solution for multiband, reconfigurable wireless communication systems. The integration of double-split-ring resonators and dynamic reconfigurability makes the proposed antenna a strong candidate for various applications, including S-band and X-band systems, as well as the emerging lower 6G band(7.125 GHz–8.400 GHz).
