Let I be the set of all infinitely divisible random variables with finite second moments,I_(0)={X∈I;Var(X)>0},P_(I)=inf_(x∈I)P{|X-E[X]|≤√Var(X)}and P_(I_(0))=inf P{|X-E[X]|<√Var(X)}.Firstly,we prove that P_...Let I be the set of all infinitely divisible random variables with finite second moments,I_(0)={X∈I;Var(X)>0},P_(I)=inf_(x∈I)P{|X-E[X]|≤√Var(X)}and P_(I_(0))=inf P{|X-E[X]|<√Var(X)}.Firstly,we prove that P_(I)≥P_(I_(0))>0.Secondly,we find_(x∈I_(0))the exact values of inf P{|X-E[X]|≤√Var(X)}and inf P{|X-E[X]|<√Var(X)}for the cases that J is the set of all geometric random variables,symmetric geometric random variables,Poisson random variables and symmetric Poisson random variables,respectively.As a consequence,we obtain that P_(I)≤e^(-1)^(∞)∑_(k=0)1/2^(2k)(k!)^(2)≈0.46576 and P_(I_(0))≤e^(-1)≈0.36788.展开更多
In this paper, we describe all the divisible semiring congruences on a distributive semiring S and also establish a one_to_one, inclusion_preserving mapping from the set of full, closed, self_conjagate, ideal subsemir...In this paper, we describe all the divisible semiring congruences on a distributive semiring S and also establish a one_to_one, inclusion_preserving mapping from the set of full, closed, self_conjagate, ideal subsemirings of S to the set of all divisible semiring congruences on S.展开更多
In this paper, we investigate the existence of incomplete group divisible designs （IGDDs） with block size four, group-type （g, h） u and general index λ. The necessary conditions for the existence of such a design...In this paper, we investigate the existence of incomplete group divisible designs （IGDDs） with block size four, group-type （g, h） u and general index λ. The necessary conditions for the existence of such a design are that u ≥ 4, g ≥ 3h, λg（u 1） ≡ 0 （mod 3）, λ（g h）（u 1） ≡ 0 （mod 3）, and λu（u 1）（g 2 h 2 ） ≡ 0 （mod 12）. These necessary conditions are shown to be sufficient for all λ≥ 2. The known existence result for λ = 1 is also improved.展开更多
Over 200 health journals call on the United Nations(UN),political leaders and health professionals to recognise that climate change and biodiversity loss are one indivisible crisis and must be tackled together to pres...Over 200 health journals call on the United Nations(UN),political leaders and health professionals to recognise that climate change and biodiversity loss are one indivisible crisis and must be tackled together to preserve health and avoid catastrophe.This overall environmental crisis is now so severe as to be a global health emergency.展开更多
Over 200 health journals call on the United Nations(UN),political leaders and health professionals to recognise that climate change and biodiversity loss are one indivisible crisis and must be tackled together to pres...Over 200 health journals call on the United Nations(UN),political leaders and health professionals to recognise that climate change and biodiversity loss are one indivisible crisis and must be tackled together to preserve health and avoid catastrophe.This overall environmental crisis is now so severe as to be a global health emergency.展开更多
The Electrical Power System(EPS)is one of the spacecraft’s key subsystems,and its operational status directly affects the lifespan and performance of the entire spacecraft.The corresponding fault diagnosis has always...The Electrical Power System(EPS)is one of the spacecraft’s key subsystems,and its operational status directly affects the lifespan and performance of the entire spacecraft.The corresponding fault diagnosis has always been the discussion focus to ensure spacecraft reliability.In this paper,a few-shot unsupervised fault diagnosis method based on the improved Newman community division algorithm is proposed,to approach the scarcity of fault data samples and the inconspicuous characteristics of abnormal data.Firstly,aiming to capture the overall relevance of the fault dataset,a complex network model is built by adopting the K-Dynamic time warping distance Adjacent Nodes(KDAN)method.Based on the complex network model,the Newman community divisions algorithm is improved by using the Quantum-behaved Particle Swarm Optimization(QPSO).Subsequently,in order to evaluate the feasibility of the proposed method,experimental validation was conducted using an open-source dataset.The results indicate that the average accuracy can reach 96.43% for fault data diagnosis,and an F1_score of 97.76%with only 17.65%of the dataset used for training.The proposed method can accurately classify abnormal data by identifying the community structure in the data network,significantly improve the efficiency of the community divisions algorithm and reduce its complexity,and provide a new solution for fault diagnosis in large-scale complex systems.展开更多
Engineering optimization problems are often characterized by high dimensionality,constraints,and complex,multimodal landscapes.Traditional deterministic methods frequently struggle under such conditions,prompting incr...Engineering optimization problems are often characterized by high dimensionality,constraints,and complex,multimodal landscapes.Traditional deterministic methods frequently struggle under such conditions,prompting increased interest in swarm intelligence algorithms.Among these,the Cuckoo Search(CS)algorithm stands out for its promising global search capabilities.However,it often suffers from premature convergence when tackling complex problems.To address this limitation,this paper proposes a Grouped Dynamic Adaptive CS(GDACS)algorithm.Theenhancements incorporated intoGDACS can be summarized into two key aspects.Firstly,a chaotic map is employed to generate initial solutions,leveraging the inherent randomness of chaotic sequences to ensure a more uniform distribution across the search space and enhance population diversity from the outset.Secondly,Cauchy and Levy strategies replace the standard CS population update.This strategy involves evaluating the fitness of candidate solutions to dynamically group the population based on performance.Different step-size adaptation strategies are then applied to distinct groups,enabling an adaptive search mechanism that balances exploration and exploitation.Experiments were conducted on six benchmark functions and four constrained engineering design problems,and the results indicate that the proposed GDACS achieves good search efficiency and produces more accurate optimization results compared with other state-of-the-art algorithms.展开更多
Understanding the acid resistance mechanism of S.mutans is crucial for preventing dental caries.FtsZ is the core protein for cell division in bacteria that can polymerize into Z-rings and drive cytokinesis.Our previou...Understanding the acid resistance mechanism of S.mutans is crucial for preventing dental caries.FtsZ is the core protein for cell division in bacteria that can polymerize into Z-rings and drive cytokinesis.Our previous study revealed that the FtsZ in S.mutans(SmFtsZ) has higher self-assembly and GTPase activity under acidic stress,which may be responsible for acid resistance and ca riogenesis of S.mutans.However,the functional structure mechanism of SmFtsZ under low pH conditions is still unclear.Here,we further reported the crystal structure of S.mutans FtsZ,revealing a unique lateral interface.Through protein polymerization and GTPase activity assay,we experimentally demonstrated that the mutation of Arg68 on this lateral interface significantly reduced the functional activity of FtsZ in an acidic environment.The phenotype assay and rat caries model further showed that the mutation of Arg68 effectively inhibited the acid resistance of S.mutans and the occurrence and progress of dental caries in vivo.By employing a molecular dynamics simulation analysis,we conclude that the mutation of Arg68 disrupts the conformation change necessary for SmFtsZ polymerization under acidic conditions.Our study proposes a novel mechanism to maintain FtsZ function in bacteria and could be a potential target for antimicrobial drugs to inhibit the growth of S.mutans in acidic environments.展开更多
Orthogonal Frequency Division Multiplexing(OFDM)enables efficient Dynamic Spectrum Access(DSA)but suffers from high sidelobe that causes excessive out-of-band(OOB)emissions and expose the system to spectrum-layer cybe...Orthogonal Frequency Division Multiplexing(OFDM)enables efficient Dynamic Spectrum Access(DSA)but suffers from high sidelobe that causes excessive out-of-band(OOB)emissions and expose the system to spectrum-layer cyberattacks such as man-in-the-middle(MITM),eavesdropping,and primary user emulation(PUE)attacks.To address both spectral leakage and its security implications,this paper introduces a secure and intelligent hybrid optimization strategy that combinesan Eigenspace-based Generalized Sidelobe Canceller(ES-GSC)with a Genetic Algorithm(GA),to derive optimally weighted cancellation carriers.The proposed method jointly suppresses sidelobes and reinforces resistance to leakage-based attacks.MATLAB Simulation demonstrate considerable reductions in OOB emissions and higher resilience against spectrum-layer threats compared with existing techniques.展开更多
In the context of the coordinated pursuit of"carbon peak and neutrality"objectives,alongside the strategy to establish a robust agricultural nation,the economic and social development of rural areas is under...In the context of the coordinated pursuit of"carbon peak and neutrality"objectives,alongside the strategy to establish a robust agricultural nation,the economic and social development of rural areas is undergoing a profound paradigm shift.The traditional rural division of labor pattern,which depends on tangible factors such as land,labor,and capital,has increasingly encountered developmental challenges characterized by diminishing marginal returns and a detrimental cycle of internal competition.The new quality productive force,centered on data,algorithms,green technologies,bioengineering,and clean energy,offers a potential pathway for the rural division of labor system to overcome the"low-level equilibrium".This force is characterized by attributes such as non-exclusivity,replicability,network collaboration,and ecological compatibility.This paper develops a three-dimensional collaborative analytical framework encompassing"technology,institution,and culture".It systematically elucidates the internal logic by which new quality productive forces drive the transformation of the rural division of labor from"quantitative factor matching"to"qualitative structural reorganization"through three principal mechanisms:technology embedding,institutional reconstruction,and cultural coupling.Furthermore,the study proposes corresponding policy recommendations,thereby offering theoretical insights to support the modernization of China s agriculture and rural areas,as well as the development of a strong agricultural country.展开更多
At the World Economic Forum Annual Meeting 2026 in Davos,China emerged as a steadfast advocate for multilateral cooperation and constructive dialogue,presenting a clear alternative to divisive rhetoric.CHINA’S role a...At the World Economic Forum Annual Meeting 2026 in Davos,China emerged as a steadfast advocate for multilateral cooperation and constructive dialogue,presenting a clear alternative to divisive rhetoric.CHINA’S role as a key player in shaping global development and trends stood out at the World Economic Forum(WEF)annual meeting 2026 in Davos,Switzerland.展开更多
In the past few decades,China's foreign trade,leveraging its comprehensive industrial system,resilient supply chain,and factor cost advantages,has steadily constructed a global division of labor pattern as the“wo...In the past few decades,China's foreign trade,leveraging its comprehensive industrial system,resilient supply chain,and factor cost advantages,has steadily constructed a global division of labor pattern as the“world's factory”.展开更多
Neuroscience (also known as neurobiology) is a science that studies the structure, function, development, pharmacology and pathology of the nervous system. In recent years, C. Cotardo has introduced coding theory into...Neuroscience (also known as neurobiology) is a science that studies the structure, function, development, pharmacology and pathology of the nervous system. In recent years, C. Cotardo has introduced coding theory into neuroscience, proposing the concept of combinatorial neural codes. And it was further studied in depth using algebraic methods by C. Curto. In this paper, we construct a class of combinatorial neural codes with special properties based on classical combinatorial structures such as orthogonal Latin rectangle, disjoint Steiner systems, groupable designs and transversal designs. These neural codes have significant weight distribution properties and large minimum distances, and are thus valuable for potential applications in information representation and neuroscience. This study provides new ideas for the construction method and property analysis of combinatorial neural codes, and enriches the study of algebraic coding theory.展开更多
Affected by the pandemic coronavirus-19(COVID-19),significant changes have taken place in all aspects of social production and residents’lives,as well as in the energy supply and consumption characteristics of the po...Affected by the pandemic coronavirus-19(COVID-19),significant changes have taken place in all aspects of social production and residents’lives,as well as in the energy supply and consumption characteristics of the power system.COVID-19 has brought unpredictable uncertainties to the power grid.These changes and uncertainties pose a challenge to conventional electric load forecasting.Therefore,aiming to load forecasting under the background of the pandemic,this paper proposes a power load segmented forecasting method based on the pandemic stage division method,attention mechanism,and bi-directional long and short-term memory artificial neural network quantile regression model(ESD-ABiLSTMQR).According to the development degree of the pandemic,considering characteristics of different development stages of the pandemic,the pandemic is divided into four stages by using the analytic hierarchy process method(AHP):initial stage,outbreak stage,control stage,and recovery stage.A segmented load forecasting model based on LSTM and attention mechanism is established to forecast load in different time series.Cases used data from the pandemic in Wuhan,China,for verification.Results show the segmented forecasting method can analyze load characteristics of each stage and can effectively improve the accuracy of load forecasting.展开更多
Fast and accurate transient stability analysis is crucial to power system operation.With high penetration level of wind power resources,practical dynamic security region(PDSR)with hyper plane expression has outstandin...Fast and accurate transient stability analysis is crucial to power system operation.With high penetration level of wind power resources,practical dynamic security region(PDSR)with hyper plane expression has outstanding advantages in situational awareness and series of optimization problems.The precondition of obtaining accurate PDSR boundary is to locate sufficient points around the boundary(critical points).Therefore,this paper proposes a space division and Wasserstein generative adversarial network with gra-dient penalty(WGAN-GP)based fast generation method of PDSR boundary.First,the typical differential topological characterizations of dynamic security region(DSR)provide strong theoretical foundation that the interior of DSR is hole-free and the boundaries of DSR are tight and knot-free.Then,the space division method is proposed to calculate critical operation area where the PDSR boundary is located,tremen-dously compressing the search space to locate critical points and improving the confidence level of boundary fitting result.Furthermore,the WGAN-GP model is utilized to fast obtain large number of criti-cal points based on learning the data distribution of the small training set aforementioned.Finally,the PDSR boundary with hyperplanes is fitted by the least square method.The case study is tested on the Institute of Electrical and Electronics Engineers(IEEE)39-bus system and the results verify the accuracy and efficiency of the proposed method.展开更多
Sixth Generation(6G)mobile communication networks will involve sensing as a new function,with the overwhelming trend of Integrated Sensing And Communications(ISAC).Although expanding the serving range of the networks,...Sixth Generation(6G)mobile communication networks will involve sensing as a new function,with the overwhelming trend of Integrated Sensing And Communications(ISAC).Although expanding the serving range of the networks,there exists performance trade-offbetween communication and sensing,in that they have competitions on the physical resources.Different resource allocation schemes will result in different sensing and communication performance,thus influencing the system’s overall performance.Therefore,how to model the system’s overall performance,and how to optimize it are key issues for ISAC.Relying on the large-scale deployment of the networks,cooperative ISAC has the advantages of wider coverage,more robust performance and good compatibility of multiple monostatic and multistatic sensing,compared to the non-cooperative ISAC.How to capture the performance gain of cooperation is a key issue for cooperative ISAC.To address the aforementioned vital problems,in this paper,we analyze the sensing accuracy gain,propose a unified ISAC performance evaluation framework and design several optimization methods in cooperative ISAC systems.The cooperative sensing accuracy gain is theoretically analyzed via Cramér Rao lower bound.The unified ISAC performance evaluation model is established by converting the communication mutual information to the effective minimum mean squared error.To optimize the unified ISAC performance,we design the optimization algorithms considering three factors:base stations’working modes,power allocation schemes and waveform design.Through simulations,we show the performance gain of the cooperative ISAC system and the effectiveness of the proposed optimization methods.展开更多
In this paper,we prove that Euclid's algorithm,Bezout's equation and Divi-sion algorithm are equivalent to each other.Our result shows that Euclid has preliminarily established the theory of divisibility and t...In this paper,we prove that Euclid's algorithm,Bezout's equation and Divi-sion algorithm are equivalent to each other.Our result shows that Euclid has preliminarily established the theory of divisibility and the greatest common divisor.We further provided several suggestions for teaching.展开更多
In order to accurately forecast the main engine fuel consumption and reduce the Energy Efficiency Operational Indicator(EEOI)of merchant ships in polar ice areas,the energy transfer relationship between ship-machine-p...In order to accurately forecast the main engine fuel consumption and reduce the Energy Efficiency Operational Indicator(EEOI)of merchant ships in polar ice areas,the energy transfer relationship between ship-machine-propeller is studied by analyzing the complex force situation during ship navigation and building a MATLAB/Simulink simulation platform based on multi-environmental resistance,propeller efficiency,main engine power,fuel consumption,fuel consumption rate and EEOI calculation module.Considering the environmental factors of wind,wave and ice,the route is divided into sections,the calculation of main engine power,main engine fuel consumption and EEOI for each section is completed,and the speed design is optimized based on the simulation model for each section.Under the requirements of the voyage plan,the optimization results show that the energy efficiency operation index of the whole route is reduced by 3.114%and the fuel consumption is reduced by 9.17 t.展开更多
A 16-channel arrayed waveguide grating(AWG)with an 800 GHz channel spacing in the O-band has been developed and fabricated based on silica planar lightwave circuit(PLC)technology.By extending the wave⁃length allocatio...A 16-channel arrayed waveguide grating(AWG)with an 800 GHz channel spacing in the O-band has been developed and fabricated based on silica planar lightwave circuit(PLC)technology.By extending the wave⁃length allocation from 8 channels to 16 channels as specified in IEEE 802.3bs,we increased the number of chan⁃nels and boosted transmission capacity to meet the 1.6 Tbps and higher-speed signal transmission requirements for future data centers.Through optimizing the AWG structure,it has achieved insertion loss(IL)better than-1.61 dB,loss uniformity below 0.35 dB,polarization-dependent loss(PDL)below 0.35 dB,adjacent channel cross⁃talk under-20.05 dB,ripple less than 0.75 dB,center wavelength offset under 0.22 nm and 1 dB bandwidth ex⁃ceeding 2.88 nm.The AWG has been successfully measured to transmit 53 Gbaud 4-level pulse amplitude modu⁃lation(PAM4)signal per channel and the total transmission speed can reach over 1.6 Tbps.展开更多
2024 is a“super election year”with the biggest influence in the world since World War II.About 80 countries covering about 60%of the world's population hold national elections.The number and scale of elections a...2024 is a“super election year”with the biggest influence in the world since World War II.About 80 countries covering about 60%of the world's population hold national elections.The number and scale of elections are rare in history.The processes and results of many countries'elections are so dramatic,with a series of exchanges,offenses and defenses,which further highlights the trend of intensified political confrontation and social division around the world.展开更多
基金supported by the National Natural Science Foundation of China(12161029,12171335)the National Natural Science Foundation of Hainan Province(121RC149)+1 种基金the Science Development Project of Sichuan University(2020SCUNL201)the Natural Sciences and Engineering Research Council of Canada(4394-2018).
文摘Let I be the set of all infinitely divisible random variables with finite second moments,I_(0)={X∈I;Var(X)>0},P_(I)=inf_(x∈I)P{|X-E[X]|≤√Var(X)}and P_(I_(0))=inf P{|X-E[X]|<√Var(X)}.Firstly,we prove that P_(I)≥P_(I_(0))>0.Secondly,we find_(x∈I_(0))the exact values of inf P{|X-E[X]|≤√Var(X)}and inf P{|X-E[X]|<√Var(X)}for the cases that J is the set of all geometric random variables,symmetric geometric random variables,Poisson random variables and symmetric Poisson random variables,respectively.As a consequence,we obtain that P_(I)≤e^(-1)^(∞)∑_(k=0)1/2^(2k)(k!)^(2)≈0.46576 and P_(I_(0))≤e^(-1)≈0.36788.
文摘In this paper, we describe all the divisible semiring congruences on a distributive semiring S and also establish a one_to_one, inclusion_preserving mapping from the set of full, closed, self_conjagate, ideal subsemirings of S to the set of all divisible semiring congruences on S.
基金Supported by the National Natural Science Foundation of China (No. 10571043, 10771051, 11001182, 10901051)
文摘In this paper, we investigate the existence of incomplete group divisible designs （IGDDs） with block size four, group-type （g, h） u and general index λ. The necessary conditions for the existence of such a design are that u ≥ 4, g ≥ 3h, λg（u 1） ≡ 0 （mod 3）, λ（g h）（u 1） ≡ 0 （mod 3）, and λu（u 1）（g 2 h 2 ） ≡ 0 （mod 12）. These necessary conditions are shown to be sufficient for all λ≥ 2. The known existence result for λ = 1 is also improved.
文摘Over 200 health journals call on the United Nations(UN),political leaders and health professionals to recognise that climate change and biodiversity loss are one indivisible crisis and must be tackled together to preserve health and avoid catastrophe.This overall environmental crisis is now so severe as to be a global health emergency.
文摘Over 200 health journals call on the United Nations(UN),political leaders and health professionals to recognise that climate change and biodiversity loss are one indivisible crisis and must be tackled together to preserve health and avoid catastrophe.This overall environmental crisis is now so severe as to be a global health emergency.
基金supported in part by the Natural Science Foundation of Shanghai,China(No.23ZR1432400)the Shanghai Pilot Program for Basic Research-Chinese Academy of Science(No.JCYJ-SHFY-2022-015).
文摘The Electrical Power System(EPS)is one of the spacecraft’s key subsystems,and its operational status directly affects the lifespan and performance of the entire spacecraft.The corresponding fault diagnosis has always been the discussion focus to ensure spacecraft reliability.In this paper,a few-shot unsupervised fault diagnosis method based on the improved Newman community division algorithm is proposed,to approach the scarcity of fault data samples and the inconspicuous characteristics of abnormal data.Firstly,aiming to capture the overall relevance of the fault dataset,a complex network model is built by adopting the K-Dynamic time warping distance Adjacent Nodes(KDAN)method.Based on the complex network model,the Newman community divisions algorithm is improved by using the Quantum-behaved Particle Swarm Optimization(QPSO).Subsequently,in order to evaluate the feasibility of the proposed method,experimental validation was conducted using an open-source dataset.The results indicate that the average accuracy can reach 96.43% for fault data diagnosis,and an F1_score of 97.76%with only 17.65%of the dataset used for training.The proposed method can accurately classify abnormal data by identifying the community structure in the data network,significantly improve the efficiency of the community divisions algorithm and reduce its complexity,and provide a new solution for fault diagnosis in large-scale complex systems.
基金supported in part by the Ministry of Higher Education Malaysia(MOHE)through Fundamental Research Grant Scheme(FRGS)Ref:FRGS/1/2024/ICT02/UTM/02/10,Vot.No:R.J130000.7828.5F748the Scientific Research Project of Education Department of Hunan Province(Nos.22B1046 and 24A0771).
文摘Engineering optimization problems are often characterized by high dimensionality,constraints,and complex,multimodal landscapes.Traditional deterministic methods frequently struggle under such conditions,prompting increased interest in swarm intelligence algorithms.Among these,the Cuckoo Search(CS)algorithm stands out for its promising global search capabilities.However,it often suffers from premature convergence when tackling complex problems.To address this limitation,this paper proposes a Grouped Dynamic Adaptive CS(GDACS)algorithm.Theenhancements incorporated intoGDACS can be summarized into two key aspects.Firstly,a chaotic map is employed to generate initial solutions,leveraging the inherent randomness of chaotic sequences to ensure a more uniform distribution across the search space and enhance population diversity from the outset.Secondly,Cauchy and Levy strategies replace the standard CS population update.This strategy involves evaluating the fitness of candidate solutions to dynamically group the population based on performance.Different step-size adaptation strategies are then applied to distinct groups,enabling an adaptive search mechanism that balances exploration and exploitation.Experiments were conducted on six benchmark functions and four constrained engineering design problems,and the results indicate that the proposed GDACS achieves good search efficiency and produces more accurate optimization results compared with other state-of-the-art algorithms.
基金supported by the Beijing Natural Science Foundation:7222220National Natural Science Foundation of China (82001039)+2 种基金Research Foundation of Peking University School and Hospital of Stomatology:PKUSS20230117The Fundamental Research Funds for the Central UniversitiesYoung Elite Scientist Sponsorship Program by CAST (No.2019QNRC001 to Y.L.L)。
文摘Understanding the acid resistance mechanism of S.mutans is crucial for preventing dental caries.FtsZ is the core protein for cell division in bacteria that can polymerize into Z-rings and drive cytokinesis.Our previous study revealed that the FtsZ in S.mutans(SmFtsZ) has higher self-assembly and GTPase activity under acidic stress,which may be responsible for acid resistance and ca riogenesis of S.mutans.However,the functional structure mechanism of SmFtsZ under low pH conditions is still unclear.Here,we further reported the crystal structure of S.mutans FtsZ,revealing a unique lateral interface.Through protein polymerization and GTPase activity assay,we experimentally demonstrated that the mutation of Arg68 on this lateral interface significantly reduced the functional activity of FtsZ in an acidic environment.The phenotype assay and rat caries model further showed that the mutation of Arg68 effectively inhibited the acid resistance of S.mutans and the occurrence and progress of dental caries in vivo.By employing a molecular dynamics simulation analysis,we conclude that the mutation of Arg68 disrupts the conformation change necessary for SmFtsZ polymerization under acidic conditions.Our study proposes a novel mechanism to maintain FtsZ function in bacteria and could be a potential target for antimicrobial drugs to inhibit the growth of S.mutans in acidic environments.
文摘Orthogonal Frequency Division Multiplexing(OFDM)enables efficient Dynamic Spectrum Access(DSA)but suffers from high sidelobe that causes excessive out-of-band(OOB)emissions and expose the system to spectrum-layer cyberattacks such as man-in-the-middle(MITM),eavesdropping,and primary user emulation(PUE)attacks.To address both spectral leakage and its security implications,this paper introduces a secure and intelligent hybrid optimization strategy that combinesan Eigenspace-based Generalized Sidelobe Canceller(ES-GSC)with a Genetic Algorithm(GA),to derive optimally weighted cancellation carriers.The proposed method jointly suppresses sidelobes and reinforces resistance to leakage-based attacks.MATLAB Simulation demonstrate considerable reductions in OOB emissions and higher resilience against spectrum-layer threats compared with existing techniques.
基金Supported by Key Project of Jiangsu Education Science Planning"Research on the Structural Adjustment of Higher Education in Jiangsu in the Context of High-Quality Economic Development"(B/2021/01/67).
文摘In the context of the coordinated pursuit of"carbon peak and neutrality"objectives,alongside the strategy to establish a robust agricultural nation,the economic and social development of rural areas is undergoing a profound paradigm shift.The traditional rural division of labor pattern,which depends on tangible factors such as land,labor,and capital,has increasingly encountered developmental challenges characterized by diminishing marginal returns and a detrimental cycle of internal competition.The new quality productive force,centered on data,algorithms,green technologies,bioengineering,and clean energy,offers a potential pathway for the rural division of labor system to overcome the"low-level equilibrium".This force is characterized by attributes such as non-exclusivity,replicability,network collaboration,and ecological compatibility.This paper develops a three-dimensional collaborative analytical framework encompassing"technology,institution,and culture".It systematically elucidates the internal logic by which new quality productive forces drive the transformation of the rural division of labor from"quantitative factor matching"to"qualitative structural reorganization"through three principal mechanisms:technology embedding,institutional reconstruction,and cultural coupling.Furthermore,the study proposes corresponding policy recommendations,thereby offering theoretical insights to support the modernization of China s agriculture and rural areas,as well as the development of a strong agricultural country.
文摘At the World Economic Forum Annual Meeting 2026 in Davos,China emerged as a steadfast advocate for multilateral cooperation and constructive dialogue,presenting a clear alternative to divisive rhetoric.CHINA’S role as a key player in shaping global development and trends stood out at the World Economic Forum(WEF)annual meeting 2026 in Davos,Switzerland.
文摘In the past few decades,China's foreign trade,leveraging its comprehensive industrial system,resilient supply chain,and factor cost advantages,has steadily constructed a global division of labor pattern as the“world's factory”.
文摘Neuroscience (also known as neurobiology) is a science that studies the structure, function, development, pharmacology and pathology of the nervous system. In recent years, C. Cotardo has introduced coding theory into neuroscience, proposing the concept of combinatorial neural codes. And it was further studied in depth using algebraic methods by C. Curto. In this paper, we construct a class of combinatorial neural codes with special properties based on classical combinatorial structures such as orthogonal Latin rectangle, disjoint Steiner systems, groupable designs and transversal designs. These neural codes have significant weight distribution properties and large minimum distances, and are thus valuable for potential applications in information representation and neuroscience. This study provides new ideas for the construction method and property analysis of combinatorial neural codes, and enriches the study of algebraic coding theory.
基金supported by National Natural Science Foundation of China(No.52407074)Anhui Provincial Natural Science Foundation Youth Project,China(2308085QE177)Key Research Projects in Natural Sciences of Universities funded by the Department of Education in Anhui Province,China(2023AH050092).
文摘Affected by the pandemic coronavirus-19(COVID-19),significant changes have taken place in all aspects of social production and residents’lives,as well as in the energy supply and consumption characteristics of the power system.COVID-19 has brought unpredictable uncertainties to the power grid.These changes and uncertainties pose a challenge to conventional electric load forecasting.Therefore,aiming to load forecasting under the background of the pandemic,this paper proposes a power load segmented forecasting method based on the pandemic stage division method,attention mechanism,and bi-directional long and short-term memory artificial neural network quantile regression model(ESD-ABiLSTMQR).According to the development degree of the pandemic,considering characteristics of different development stages of the pandemic,the pandemic is divided into four stages by using the analytic hierarchy process method(AHP):initial stage,outbreak stage,control stage,and recovery stage.A segmented load forecasting model based on LSTM and attention mechanism is established to forecast load in different time series.Cases used data from the pandemic in Wuhan,China,for verification.Results show the segmented forecasting method can analyze load characteristics of each stage and can effectively improve the accuracy of load forecasting.
基金funded in part by the National Key Research and Development Program of China(2020YFB0905900)in part by Science and Technology Project of State Grid Corporation of China(SGCC)The Key Technologies for Electric Internet of Things(SGTJDK00DWJS2100223).
文摘Fast and accurate transient stability analysis is crucial to power system operation.With high penetration level of wind power resources,practical dynamic security region(PDSR)with hyper plane expression has outstanding advantages in situational awareness and series of optimization problems.The precondition of obtaining accurate PDSR boundary is to locate sufficient points around the boundary(critical points).Therefore,this paper proposes a space division and Wasserstein generative adversarial network with gra-dient penalty(WGAN-GP)based fast generation method of PDSR boundary.First,the typical differential topological characterizations of dynamic security region(DSR)provide strong theoretical foundation that the interior of DSR is hole-free and the boundaries of DSR are tight and knot-free.Then,the space division method is proposed to calculate critical operation area where the PDSR boundary is located,tremen-dously compressing the search space to locate critical points and improving the confidence level of boundary fitting result.Furthermore,the WGAN-GP model is utilized to fast obtain large number of criti-cal points based on learning the data distribution of the small training set aforementioned.Finally,the PDSR boundary with hyperplanes is fitted by the least square method.The case study is tested on the Institute of Electrical and Electronics Engineers(IEEE)39-bus system and the results verify the accuracy and efficiency of the proposed method.
文摘Sixth Generation(6G)mobile communication networks will involve sensing as a new function,with the overwhelming trend of Integrated Sensing And Communications(ISAC).Although expanding the serving range of the networks,there exists performance trade-offbetween communication and sensing,in that they have competitions on the physical resources.Different resource allocation schemes will result in different sensing and communication performance,thus influencing the system’s overall performance.Therefore,how to model the system’s overall performance,and how to optimize it are key issues for ISAC.Relying on the large-scale deployment of the networks,cooperative ISAC has the advantages of wider coverage,more robust performance and good compatibility of multiple monostatic and multistatic sensing,compared to the non-cooperative ISAC.How to capture the performance gain of cooperation is a key issue for cooperative ISAC.To address the aforementioned vital problems,in this paper,we analyze the sensing accuracy gain,propose a unified ISAC performance evaluation framework and design several optimization methods in cooperative ISAC systems.The cooperative sensing accuracy gain is theoretically analyzed via Cramér Rao lower bound.The unified ISAC performance evaluation model is established by converting the communication mutual information to the effective minimum mean squared error.To optimize the unified ISAC performance,we design the optimization algorithms considering three factors:base stations’working modes,power allocation schemes and waveform design.Through simulations,we show the performance gain of the cooperative ISAC system and the effectiveness of the proposed optimization methods.
基金Supported by the Natural Science Foundation of Chongqing(General Program,NO.CSTB2022NSCQ-MSX0884)Discipline Teaching Special Project of Yangtze Normal University(csxkjx14)。
文摘In this paper,we prove that Euclid's algorithm,Bezout's equation and Divi-sion algorithm are equivalent to each other.Our result shows that Euclid has preliminarily established the theory of divisibility and the greatest common divisor.We further provided several suggestions for teaching.
文摘In order to accurately forecast the main engine fuel consumption and reduce the Energy Efficiency Operational Indicator(EEOI)of merchant ships in polar ice areas,the energy transfer relationship between ship-machine-propeller is studied by analyzing the complex force situation during ship navigation and building a MATLAB/Simulink simulation platform based on multi-environmental resistance,propeller efficiency,main engine power,fuel consumption,fuel consumption rate and EEOI calculation module.Considering the environmental factors of wind,wave and ice,the route is divided into sections,the calculation of main engine power,main engine fuel consumption and EEOI for each section is completed,and the speed design is optimized based on the simulation model for each section.Under the requirements of the voyage plan,the optimization results show that the energy efficiency operation index of the whole route is reduced by 3.114%and the fuel consumption is reduced by 9.17 t.
基金Supported by the National Key Research and Development Program of China(2021YFB2800201)the Strategic Priority Research Program of Chinese Academy of Sciences(XDB43000000)。
文摘A 16-channel arrayed waveguide grating(AWG)with an 800 GHz channel spacing in the O-band has been developed and fabricated based on silica planar lightwave circuit(PLC)technology.By extending the wave⁃length allocation from 8 channels to 16 channels as specified in IEEE 802.3bs,we increased the number of chan⁃nels and boosted transmission capacity to meet the 1.6 Tbps and higher-speed signal transmission requirements for future data centers.Through optimizing the AWG structure,it has achieved insertion loss(IL)better than-1.61 dB,loss uniformity below 0.35 dB,polarization-dependent loss(PDL)below 0.35 dB,adjacent channel cross⁃talk under-20.05 dB,ripple less than 0.75 dB,center wavelength offset under 0.22 nm and 1 dB bandwidth ex⁃ceeding 2.88 nm.The AWG has been successfully measured to transmit 53 Gbaud 4-level pulse amplitude modu⁃lation(PAM4)signal per channel and the total transmission speed can reach over 1.6 Tbps.
文摘2024 is a“super election year”with the biggest influence in the world since World War II.About 80 countries covering about 60%of the world's population hold national elections.The number and scale of elections are rare in history.The processes and results of many countries'elections are so dramatic,with a series of exchanges,offenses and defenses,which further highlights the trend of intensified political confrontation and social division around the world.
