The new three-phase 5-level current-source inverter (CSI) proposed in this paper was developed by connecting three separate single-phase 5-level CSIs in series, and its operational principle was analyzed. There are tw...The new three-phase 5-level current-source inverter (CSI) proposed in this paper was developed by connecting three separate single-phase 5-level CSIs in series, and its operational principle was analyzed. There are two major problems existing in current-source multilevel inverters, one is the complex PWM control method (2-logic to 3-logic conversion), and the other is the problem of current-unbalance between different levels. A simple current-balance control method via DC current feedback is applied in each single-phase 5-level CSI cell to implement the current-balance control between different levels. And to reduce the output current harmonics, POD PWM control technique was used. Simulation and experimental results showed that this new three-phase 5-level CSI topology operates correctly.展开更多
The new 6-switch single-phase 5-level current-source inverter proposed in this paper was developed by properly simplifying the traditional 8-switch single-phase 5-level current-source inverter, and its operational pri...The new 6-switch single-phase 5-level current-source inverter proposed in this paper was developed by properly simplifying the traditional 8-switch single-phase 5-level current-source inverter, and its operational principle was analyzed. Just like the problem of voltage-unbalance between different levels existing in voltage-source multilevel inverters, a similar problem of current-unbalance between different levels whether for the 8-switch single-phase 5-level current-source inverter, or for the new 6-switch 5-level current-source inverter also exists. A simple current-balance control method via DC current feedback is presented here to implement the current-balance control between different levels. And to reduce the output current harmonics, PWM control technique was used. Simulation and experimental results showed that this new 6-switch topology operates correctly and that the balance-inductor can almost equally distribute the total DC current.展开更多
Under unbalanced source voltage supply, considerable output second harmonics and input low-order harmonics in 3-phase PWM current-source converters (PWM-CSC) are generated. This paper proposes a new deadbeat controlle...Under unbalanced source voltage supply, considerable output second harmonics and input low-order harmonics in 3-phase PWM current-source converters (PWM-CSC) are generated. This paper proposes a new deadbeat controller based on compensation for unbalanced source voltage and current. With the proposed scheme, the second harmonics of the output current are eliminated and low-order harmonics of the source current are reduced effectively. Simulation and experimental results con- firmed the feasibility of the proposed method.展开更多
A novel topology of the current-source grid-connected inverter is proposed based on the immittance converter theory. A control strategy of sine-sine pulse width modulation （PWM） is studied. Compared with the traditi...A novel topology of the current-source grid-connected inverter is proposed based on the immittance converter theory. A control strategy of sine-sine pulse width modulation （PWM） is studied. Compared with the traditional current-source inverter, the power frequency inductors and power frequency transformer are replaced with high frequency inductors and a high frequency transformer. Thus, the proposed inverter has advantages of small volume, low cost, low total harmonic distortion （THD）, low power losses, high power factor （PF） and simple control. Furthermore, grid voltage cannot influence output current of the grid-connected inverter and the current-source inverter with a high PF that approaches one has been realized. Finally, validity of the theory analysis and feasibility of the control scheme are shown by simulation and experimental results.展开更多
The effects of micro-ridge-furrow planting(MR)on yield and the efficiency of light,water,and thermal resource use in rapeseed were tested in a three-year field experiment comparing MR to conventional flat planting.MR ...The effects of micro-ridge-furrow planting(MR)on yield and the efficiency of light,water,and thermal resource use in rapeseed were tested in a three-year field experiment comparing MR to conventional flat planting.MR enhanced canopy heterogeneity by altering the leaf angle between plants on ridges and furrows.The heterogeneous canopy environment increased intercepted photosynthetic active radiation,alleviated canopy temperature stress,and optimized canopy humidity,leading to improvements in light-nitrogen matching and net photosynthetic rate.Consequently,dry matter and yield increased by 13.0%and 11.0%,respectively,while radiation,thermal,and precipitation utilization efficiency increased by 12.3%-16.2%.The corresponding improvements in yield and resource use efficiency were attributed to a heterogeneous canopy environment that improved microclimatic conditions.展开更多
The increased demand for personalized customization calls for new production modes to enhance collaborations among a wide range of manufacturing practitioners who unnecessarily trust each other.In this article,a block...The increased demand for personalized customization calls for new production modes to enhance collaborations among a wide range of manufacturing practitioners who unnecessarily trust each other.In this article,a blockchain-enabled manufacturing collaboration framework is proposed,with a focus on the production capacity matching problem for blockchainbased peer-to-peer(P2P)collaboration.First,a digital model of production capacity description is built for trustworthy and transparent sharing over the blockchain.Second,an optimization problem is formulated for P2P production capacity matching with objectives to maximize both social welfare and individual benefits of all participants.Third,a feasible solution based on an iterative double auction mechanism is designed to determine the optimal price and quantity for production capacity matching with a lack of personal information.It facilitates automation of the matching process while protecting users'privacy via blockchainbased smart contracts.Finally,simulation results from the Hyperledger Fabric-based prototype show that the proposed approach increases social welfare by 1.4%compared to the Bayesian game-based approach,makes all participants profitable,and achieves 90%fairness of enterprises.展开更多
This paper proposed an efficient method of image overlapping relationship analysis based on spatial index of KD tree fast search for disordered and large-scale asteroid images.In this study,the image data from asteroi...This paper proposed an efficient method of image overlapping relationship analysis based on spatial index of KD tree fast search for disordered and large-scale asteroid images.In this study,the image data from asteroid exploration missions such as Bennu,Vesta,and Ryugu were used for experiments,and the proposed image matching pairs determination algorithm was comprehensively compared with the corresponding modules of USGS ISIS in order to evaluate its performance in terms of efficiency and accuracy.The results show that when processing more than a thousand images,the proposed method greatly improves the efficiency of acquiring image matching pairs while ensuring the correctness of image overlapping relationships and accuracy of bundle adjustment.At the same time,according to the obtained image matching pairs,images that meet the requirements of Stereo Photoclinometry can be quickly selected,effectively improving the quality of 3D reconstruction models of asteroid images.展开更多
Ground source heat pump systems demonstrate significant potential for northern rural heating applications;however,the effectiveness of these systems is often limited by challenging geological conditions.For instance,i...Ground source heat pump systems demonstrate significant potential for northern rural heating applications;however,the effectiveness of these systems is often limited by challenging geological conditions.For instance,in certain regions,the installation of buried pipes for heat exchangers may be complicated,and these pipes may not always serve as efficient low-temperature heat sources for the heat pumps of the system.To address this issue,the current study explored the use of solar-energy-collecting equipment to supplement buried pipes.In this design,both solar energy and geothermal energy provide low-temperature heat to the heat pump.First,a simulation model of a solar‒ground source heat pump coupling system was established using TRNSYS.The accuracy of this model was validated through experiments and simulations on various system configurations,including varying numbers of buried pipes,different areas of solar collectors,and varying volumes of water tanks.The simulations examined the coupling characteristics of these components and their influence on system performance.The results revealed that the operating parameters of the system remained consistent across the following configurations:three buried pipes,burial depth of 20 m,collector area of 6 m^(2),and water tank volume of 0.5 m^(3);four buried pipes,burial depth of 20 m,collector area of 3 m^(2),and water tank volume of 0.5 m^(3);and five buried pipes with a burial depth of 20 m.Furthermore,the heat collection capacity of the solar collectors spanning an area of 3 m^(2)was found to be equivalent to that of one buried pipe.Moreover,the findings revealed that the solar‒ground source heat pump coupling system demonstrated a lower annual cumulative energy consumption compared to the ground source heat pump system,presenting a reduction of 5.31%compared to the energy consumption of the latter.展开更多
The concept of matching energy was proposed by Gutman and Wagner firstly in 2012. Let G be a simple graph of order n and λ1, λ2, . . . , λn be the zeros of its matching polynomial. The matching energy of a graph G ...The concept of matching energy was proposed by Gutman and Wagner firstly in 2012. Let G be a simple graph of order n and λ1, λ2, . . . , λn be the zeros of its matching polynomial. The matching energy of a graph G is defined as ME(G) = Pni=1 |λi|. By the famous Coulson’s formula, matching energies can also be calculated by an improper integral depending on a parameter. A k-claw attaching graph Gu(k) refers to the graph obtained by attaching k pendent edges to the graph G at the vertex u, where u is called the root of Gu(k). In this paper, we use some theories of mathematical analysis to obtain a new technique to compare the matching energies of two k-claw attaching graphs Gu(k) and Hv(k) with the same order, that is, limk→∞[ME(Gu(k)) − ME(Hv(k))] = ME(G − u) − ME(H − v). By the technique, we finally determine unicyclic graphs of order n with the 9th to 13th minimal matching energies for all n ≥ 58.展开更多
A dominating induced matching(DIM)of G is an induced matching that dominates every edge of G.In this note,we completely determine the number of DIMs in the generalized Petersen graph P(n,k).We prove that if P(n,k)is a...A dominating induced matching(DIM)of G is an induced matching that dominates every edge of G.In this note,we completely determine the number of DIMs in the generalized Petersen graph P(n,k).We prove that if P(n,k)is a generalized Petersen graph with n=0(mod 5)and k=2,3(mod 5),then E(P(n,k))can be partitioned into five DIMs.Meanwhile,in the left cases k=0,1,4(mod 5),we build some counterexamples to show that there exist some P(n,k)'s which are DIM-free.展开更多
High-resolution sub-meter satellite data play an increasingly crucial role in the 3D real-scene China construction initiative.Current research on 3D reconstruction using high-resolution satellite data primarily focuse...High-resolution sub-meter satellite data play an increasingly crucial role in the 3D real-scene China construction initiative.Current research on 3D reconstruction using high-resolution satellite data primarily focuses on two approaches:Multi-stereo fusion and multi-view matching.While algorithms based on these two methodologies for multi-view image 3D reconstruction have reached relative maturity,no systematic comparison has been conducted specifically on satellite data to evaluate the relative merits of multi-stereo fusion versus multi-view matching methods.This paper conducts a comparative analysis of the practical accuracy of both approaches using high-resolution satellite datasets from diverse geographical regions.To ensure fairness in accuracy comparison,both methodologies employ non-local dense matching for cost optimization.Results demonstrate that the multi-stereo fusion method outperforms multi-view matching in all evaluation metrics,exhibiting approximately 1.2%higher average matching accuracy and 10.7%superior elevation precision in the experimental datasets.Therefore,for 3D modeling applications using satellite data,we recommend adopting the multi-stereo fusion approach for digital surface model(DSM)product generation.展开更多
Most existing multi-pattern matching algorithms are designed for single English texts leading to issues such as missed matches and space expansion when applied to Chinese-English mixed-text environments.The Hash Trie-...Most existing multi-pattern matching algorithms are designed for single English texts leading to issues such as missed matches and space expansion when applied to Chinese-English mixed-text environments.The Hash Trie-based matching machine demonstrates strong compatibility with both Chinese and English,ensuring high accuracy in text processing and subtree positioning.In this study,a novel functional framework based on the HashTrie structure is proposed and mechanically verified using Isabelle/HOL.This framework is applied to design Functional Multi-Pattern Matching(FMPM),the first functional multi-pattern matching algorithm for Chinese-English mixed texts.FMPM constructs the HashTrie matching machine using character codes and threads the machine according to the associations between pattern strings.The experimental results show that as the stored string information increases,the proposed algorithm demonstrates more significant optimization in retrieval efficiency.FMPM simplifies the implementation of the Threaded Hash Trie(THT)for Chinese-English mixed texts,effectively reducing the uncertainties in the transition from the algorithm description to code implementation.FMPM addresses the problem of space explosion Chinese-English mixed texts and avoids issues such as bound variable iteration errors.The functional framework of the HashTrie structure serves as a reference for the formal verification of future HashTrie-based algorithms.展开更多
With the rapid development of online education,the impact of interface design on learning experience has become increasingly prominent.Reasonable color matching can effectively improve learning efficiency,enhance user...With the rapid development of online education,the impact of interface design on learning experience has become increasingly prominent.Reasonable color matching can effectively improve learning efficiency,enhance user engagement,and improve visual experience.This paper analyzes the application of color matching in interface design,discusses the principle of color matching in online course interfaces,and puts forward some design strategies.It provides a practical reference for the interface design of an online education platform.展开更多
This study systematically analyzes the influence mechanism of psychological factors on the competition performance of badminton athletes in capital universities through the recent actual participation of university te...This study systematically analyzes the influence mechanism of psychological factors on the competition performance of badminton athletes in capital universities through the recent actual participation of university teams in college badminton matches and combined with high-quality literature.The study finds that anxiety,self-efficacy,and factors from audiences and referees are the main influencing variables,and significant gender differences exist.Based on the empirical research results,a psychological intervention program combining mindfulness training,virtual reality technology,and biofeedback training is proposed to provide a scientific basis for psychological training of college badminton athletes.展开更多
Session-based recommendation systems(SBR)are pivotal in suggesting items by analyzing anonymized sequences of user interactions.Traditional methods,while competent,often fall short in two critical areas:they fail to a...Session-based recommendation systems(SBR)are pivotal in suggesting items by analyzing anonymized sequences of user interactions.Traditional methods,while competent,often fall short in two critical areas:they fail to address potential inter-session item transitions,which are behavioral dependencies that extend beyond individual session boundaries,and they rely on monolithic item aggregation to construct session representations.This approach does not capture the multi-scale and heterogeneous nature of user intent,leading to a decrease in modeling accuracy.To overcome these limitations,a novel approach called HMGS has been introduced.This system incorporates dual graph architectures to enhance the recommendation process.A global transition graph captures latent cross-session item dependencies,while a heterogeneous intra-session graph encodesmulti-scale item embeddings through localized feature propagation.Additionally,amulti-tier graphmatchingmechanism aligns user preference signals across different granularities,significantly improving interest localization accuracy.Empirical validation on benchmark datasets(Tmall and Diginetica)confirms HMGS’s efficacy against state-of-the-art baselines.Quantitative analysis reveals performance gains of 20.54%and 12.63%in Precision@10 on Tmall and Diginetica,respectively.Consistent improvements are observed across auxiliary metrics,with MRR@10,Precision@20,and MRR@20 exhibiting enhancements between 4.00%and 21.36%,underscoring the framework’s robustness in multi-faceted recommendation scenarios.展开更多
In this study,the wave motion in elastodynamics for unbounded media is modeled using an unsplit-field perfectly matched layer(PML)formulation that is solved by employing an isogeometric analysis(IGA).In the adopted co...In this study,the wave motion in elastodynamics for unbounded media is modeled using an unsplit-field perfectly matched layer(PML)formulation that is solved by employing an isogeometric analysis(IGA).In the adopted combination,the non-uniform rational B-spline(NURBS)functions are employed as basis functions.Moreover,the unbounded and artificial domains,defined in the PML method,are contained in a single patch domain.Based on the proposed scheme,the approximation of the geometry problem is set in a new scheme in which the PML’s absorbing and attenuation properties and the description of traveling waves can be represented.This includes a higher continuity and smoother approximation of the computed domain.As high-order NURBS basis functions are non-interpolatory,a penalty method is present to apply a time-dependent displacement load.The performance of the NURBS-based PML is analyzed through numerical examples for 1D and 2D domains,considering homogeneous and heterogeneous media.Further,we verify the long-time numerical stability of the present method.The developed method can be used to simulate hypothetical stratified domains commonly encountered in soil-structure interaction analyses.展开更多
After the design of aerospace products is completed,a manufacturability assessment needs to be conducted based on 3D model's features in terms of modeling quality and process design,otherwise the cost of design ch...After the design of aerospace products is completed,a manufacturability assessment needs to be conducted based on 3D model's features in terms of modeling quality and process design,otherwise the cost of design changes will increase.Due to the poor structure and low reusability of product manufacturing feature information and assessment knowledge in the current aerospace product manufacturability assessment process,it is difficult to realize automated manufacturability assessment.To address these issues,a domain ontology model is established for aerospace product manufacturability assessment in this paper.On this basis,a structured representation method of manufacturability assessment knowledge and a knowledge graph data layer construction method are proposed.Based on the semantic information and association information expressed by the knowledge graph,a rule matching method based on subgraph matching is proposed to improve the precision and recall.Finally,applications and experiments based on the software platform verify the effectiveness of the proposed knowledge graph construction and rule matching method.展开更多
Objective The objective of our study was to evaluate the vaccine effectiveness(VE)of the pentavalent rotavirus vaccine(RV5)among<5-year-old children in three provinces of China during 2020-2024 via a propensity sco...Objective The objective of our study was to evaluate the vaccine effectiveness(VE)of the pentavalent rotavirus vaccine(RV5)among<5-year-old children in three provinces of China during 2020-2024 via a propensity score-matched test-negative case-control study.Methods Electronic health records and immunization information systems were used to obtain data on acute gastroenteritis(AGE)cases tested for rotavirus(RV)infection.RV-positive cases were propensity score matched with RV-negative controls for age,visit month,and province.Results The study included 27,472 children with AGE aged 8 weeks to 4 years at the time of AGE diagnosis;7.98%(2,192)were RV-positive.The VE(95%confidence interval,CI)of 1-2 and 3 doses of RV5 against any medically attended RV infection(inpatient or outpatient)was 57.6%(39.8%,70.2%)and 67.2%(60.3%,72.9%),respectively.Among children who received the 3rd dose before turning 5 months of age,3-dose VE decreased from 70.4%(53.9%,81.1%)(<5 months since the 3rd dose)to 63.0%(49.1%,73.0%)(≥1 year since the 3rd dose).The three-dose VE rate was 69.4%(41.3%,84.0%)for RVGE hospitalization and 57.5%(38.9%,70.5%)for outpatient-only medically attended RVGE.Conclusion Three-dose RV5 VE against rotavirus gastroenteritis(RVGE)in children aged<5 years was higher than 1-2-dose VE.Three-dose VE decreased with time since the 3rd dose in children who received the 3rd dose before turning five months of age,but remained above 60%for at least one year.VE was higher for RVGE hospitalizations than for medically attended outpatient visits.展开更多
AIM:To compare analysis of the impact of high altitude on corneal endothelial cells,and the prognosis in patients with cataract surgeries.METHODS:Totally 265 plateau patients with cataract surgeries performed between ...AIM:To compare analysis of the impact of high altitude on corneal endothelial cells,and the prognosis in patients with cataract surgeries.METHODS:Totally 265 plateau patients with cataract surgeries performed between January 2019 and July 2022(average altitude=3000 m),and 524 plain patients with cataract surgeries performed between January 2020 and July 2022 were included.The propensity score matching(PSM)method was applied to match the basic information of patients in both regions on a 1:1 basis.Corneal endothelial cell density(ECD),coefficient of variation(CV),hexagonal cell ratio(HEX),duration of surgery,and pre-and postoperative visual acuity(VA)were compared retrospectively,and correlation tests were done.RESULTS:Totally 223 pairs have been matched successfully.The HEX in the plateau group was higher than that in the plain group(61.95%±6.191%vs 44.91%±6.829%,P<0.001).For ECD and CV,no significant differences were observed between both groups(P>0.1).The pre-and postoperative VA of patients with cataract surgeries in the plateau group were lower(1.40±0.610 vs 0.71±0.514,P<0.001&0.68±0.479 vs 0.18±0.259,P<0.001),and the duration of surgery was longer than those in the plain group(27.06±14.900 min vs 16.03±8.033 min,P<0.001).No significant associations were found between the post-operative VA and the corneal endothelial parameters(P>0.05),while the post-operative VA was significantly related to the pre-operative VA and the duration of surgery(P<0.05).CONCLUSION:The relative hypoxic environment of the plateau does not promote the apoptosis of corneal endothelial cells,but may lead to the compensatory increase of their functions.In plateau patients,no significant associations are found between the poor VA and the corneal endothelial functions early after cataract surgeries.展开更多
The cross-modal person re-identification task aims to match visible and infrared images of the same individual.The main challenges in this field arise from significant modality differences between individuals and the ...The cross-modal person re-identification task aims to match visible and infrared images of the same individual.The main challenges in this field arise from significant modality differences between individuals and the lack of high-quality cross-modal correspondence methods.Existing approaches often attempt to establish modality correspondence by extracting shared features across different modalities.However,these methods tend to focus on local information extraction and fail to fully leverage the global identity information in the cross-modal features,resulting in limited correspondence accuracy and suboptimal matching performance.To address this issue,we propose a quadratic graph matching method designed to overcome the challenges posed by modality differences through precise cross-modal relationship alignment.This method transforms the cross-modal correspondence problem into a graph matching task and minimizes the matching cost using a center search mechanism.Building on this approach,we further design a block reasoning module to uncover latent relationships between person identities and optimize the modality correspondence results.The block strategy not only improves the efficiency of updating gallery images but also enhances matching accuracy while reducing computational load.Experimental results demonstrate that our proposed method outperforms the state-of-the-art methods on the SYSU-MM01,RegDB,and RGBNT201 datasets,achieving excellent matching accuracy and robustness,thereby validating its effectiveness in cross-modal person re-identification.展开更多
基金Project (No. 50477033) supported by the National Natural Science Foundation of China
文摘The new three-phase 5-level current-source inverter (CSI) proposed in this paper was developed by connecting three separate single-phase 5-level CSIs in series, and its operational principle was analyzed. There are two major problems existing in current-source multilevel inverters, one is the complex PWM control method (2-logic to 3-logic conversion), and the other is the problem of current-unbalance between different levels. A simple current-balance control method via DC current feedback is applied in each single-phase 5-level CSI cell to implement the current-balance control between different levels. And to reduce the output current harmonics, POD PWM control technique was used. Simulation and experimental results showed that this new three-phase 5-level CSI topology operates correctly.
基金Project (No. 50477033) supported by the National Natural ScienceFoundation of China
文摘The new 6-switch single-phase 5-level current-source inverter proposed in this paper was developed by properly simplifying the traditional 8-switch single-phase 5-level current-source inverter, and its operational principle was analyzed. Just like the problem of voltage-unbalance between different levels existing in voltage-source multilevel inverters, a similar problem of current-unbalance between different levels whether for the 8-switch single-phase 5-level current-source inverter, or for the new 6-switch 5-level current-source inverter also exists. A simple current-balance control method via DC current feedback is presented here to implement the current-balance control between different levels. And to reduce the output current harmonics, PWM control technique was used. Simulation and experimental results showed that this new 6-switch topology operates correctly and that the balance-inductor can almost equally distribute the total DC current.
基金Project (No. 50477033) supported by the National Nature ScienceFoundation of China
文摘Under unbalanced source voltage supply, considerable output second harmonics and input low-order harmonics in 3-phase PWM current-source converters (PWM-CSC) are generated. This paper proposes a new deadbeat controller based on compensation for unbalanced source voltage and current. With the proposed scheme, the second harmonics of the output current are eliminated and low-order harmonics of the source current are reduced effectively. Simulation and experimental results con- firmed the feasibility of the proposed method.
基金supported by the Shanghai Leading Academic Discipline Project (Grant No.T0103)
文摘A novel topology of the current-source grid-connected inverter is proposed based on the immittance converter theory. A control strategy of sine-sine pulse width modulation （PWM） is studied. Compared with the traditional current-source inverter, the power frequency inductors and power frequency transformer are replaced with high frequency inductors and a high frequency transformer. Thus, the proposed inverter has advantages of small volume, low cost, low total harmonic distortion （THD）, low power losses, high power factor （PF） and simple control. Furthermore, grid voltage cannot influence output current of the grid-connected inverter and the current-source inverter with a high PF that approaches one has been realized. Finally, validity of the theory analysis and feasibility of the control scheme are shown by simulation and experimental results.
基金supported by the National Key Research and Development Program of China (2021YFD1901200)the Key Research and Development Program of Hubei Province of China (2023BBB028)+1 种基金the Earmarked Fund of Hubei province of Chinathe Fundamental Research Funds for the Central Universities (2662024ZKQD005)
文摘The effects of micro-ridge-furrow planting(MR)on yield and the efficiency of light,water,and thermal resource use in rapeseed were tested in a three-year field experiment comparing MR to conventional flat planting.MR enhanced canopy heterogeneity by altering the leaf angle between plants on ridges and furrows.The heterogeneous canopy environment increased intercepted photosynthetic active radiation,alleviated canopy temperature stress,and optimized canopy humidity,leading to improvements in light-nitrogen matching and net photosynthetic rate.Consequently,dry matter and yield increased by 13.0%and 11.0%,respectively,while radiation,thermal,and precipitation utilization efficiency increased by 12.3%-16.2%.The corresponding improvements in yield and resource use efficiency were attributed to a heterogeneous canopy environment that improved microclimatic conditions.
基金supported in part by the National Natural Science Foundation of China(62273310)the Natural Science Foundation of Zhejiang Province of China(LY22F030006,LZ24F030009)
文摘The increased demand for personalized customization calls for new production modes to enhance collaborations among a wide range of manufacturing practitioners who unnecessarily trust each other.In this article,a blockchain-enabled manufacturing collaboration framework is proposed,with a focus on the production capacity matching problem for blockchainbased peer-to-peer(P2P)collaboration.First,a digital model of production capacity description is built for trustworthy and transparent sharing over the blockchain.Second,an optimization problem is formulated for P2P production capacity matching with objectives to maximize both social welfare and individual benefits of all participants.Third,a feasible solution based on an iterative double auction mechanism is designed to determine the optimal price and quantity for production capacity matching with a lack of personal information.It facilitates automation of the matching process while protecting users'privacy via blockchainbased smart contracts.Finally,simulation results from the Hyperledger Fabric-based prototype show that the proposed approach increases social welfare by 1.4%compared to the Bayesian game-based approach,makes all participants profitable,and achieves 90%fairness of enterprises.
基金Space Optoelectronic Measurement and Perception Lab(LabSOMP-2023-07)the National Natural Science Foundation ofChina(42241147)+1 种基金the State Key Laboratory of Geo-Information Engineering(SKLGIE2021-Z-3-1)and the Open Program of Collaborativeinnovation Center of Geo-information(2023C002)。
文摘This paper proposed an efficient method of image overlapping relationship analysis based on spatial index of KD tree fast search for disordered and large-scale asteroid images.In this study,the image data from asteroid exploration missions such as Bennu,Vesta,and Ryugu were used for experiments,and the proposed image matching pairs determination algorithm was comprehensively compared with the corresponding modules of USGS ISIS in order to evaluate its performance in terms of efficiency and accuracy.The results show that when processing more than a thousand images,the proposed method greatly improves the efficiency of acquiring image matching pairs while ensuring the correctness of image overlapping relationships and accuracy of bundle adjustment.At the same time,according to the obtained image matching pairs,images that meet the requirements of Stereo Photoclinometry can be quickly selected,effectively improving the quality of 3D reconstruction models of asteroid images.
基金supported by 2024 Central Guidance Local Science and Technology Development Fund Project"Study on the mechanism and evaluation method of thermal pollution in water bodies,as well as research on thermal carrying capacity".(Grant 246Z4506G)Key Research and Development Project in Hebei Province:"Key Technologies and Equipment Research and Demonstration of Multiple Energy Complementary(Electricity,Heat,Cold System)for Solar Energy,Geothermal Energy,Phase Change Energy"(Grant 236Z4310G)the Hebei Academy of Sciences Key Research and Development Program"Research on Heat Transfer Mechanisms and Efficient Applications of Intermediate and Deep Geothermal Energy"(22702)。
文摘Ground source heat pump systems demonstrate significant potential for northern rural heating applications;however,the effectiveness of these systems is often limited by challenging geological conditions.For instance,in certain regions,the installation of buried pipes for heat exchangers may be complicated,and these pipes may not always serve as efficient low-temperature heat sources for the heat pumps of the system.To address this issue,the current study explored the use of solar-energy-collecting equipment to supplement buried pipes.In this design,both solar energy and geothermal energy provide low-temperature heat to the heat pump.First,a simulation model of a solar‒ground source heat pump coupling system was established using TRNSYS.The accuracy of this model was validated through experiments and simulations on various system configurations,including varying numbers of buried pipes,different areas of solar collectors,and varying volumes of water tanks.The simulations examined the coupling characteristics of these components and their influence on system performance.The results revealed that the operating parameters of the system remained consistent across the following configurations:three buried pipes,burial depth of 20 m,collector area of 6 m^(2),and water tank volume of 0.5 m^(3);four buried pipes,burial depth of 20 m,collector area of 3 m^(2),and water tank volume of 0.5 m^(3);and five buried pipes with a burial depth of 20 m.Furthermore,the heat collection capacity of the solar collectors spanning an area of 3 m^(2)was found to be equivalent to that of one buried pipe.Moreover,the findings revealed that the solar‒ground source heat pump coupling system demonstrated a lower annual cumulative energy consumption compared to the ground source heat pump system,presenting a reduction of 5.31%compared to the energy consumption of the latter.
基金Supported by the National Natural Science Foundation of China(Nos.12271439,11871398)the National College Students Innovation and Entrepreneurship Training Program(No.201910699173)。
文摘The concept of matching energy was proposed by Gutman and Wagner firstly in 2012. Let G be a simple graph of order n and λ1, λ2, . . . , λn be the zeros of its matching polynomial. The matching energy of a graph G is defined as ME(G) = Pni=1 |λi|. By the famous Coulson’s formula, matching energies can also be calculated by an improper integral depending on a parameter. A k-claw attaching graph Gu(k) refers to the graph obtained by attaching k pendent edges to the graph G at the vertex u, where u is called the root of Gu(k). In this paper, we use some theories of mathematical analysis to obtain a new technique to compare the matching energies of two k-claw attaching graphs Gu(k) and Hv(k) with the same order, that is, limk→∞[ME(Gu(k)) − ME(Hv(k))] = ME(G − u) − ME(H − v). By the technique, we finally determine unicyclic graphs of order n with the 9th to 13th minimal matching energies for all n ≥ 58.
基金Ming Chen was supported by National Key Research and Development Program of China(No.2024YFA1013900)。
文摘A dominating induced matching(DIM)of G is an induced matching that dominates every edge of G.In this note,we completely determine the number of DIMs in the generalized Petersen graph P(n,k).We prove that if P(n,k)is a generalized Petersen graph with n=0(mod 5)and k=2,3(mod 5),then E(P(n,k))can be partitioned into five DIMs.Meanwhile,in the left cases k=0,1,4(mod 5),we build some counterexamples to show that there exist some P(n,k)'s which are DIM-free.
文摘High-resolution sub-meter satellite data play an increasingly crucial role in the 3D real-scene China construction initiative.Current research on 3D reconstruction using high-resolution satellite data primarily focuses on two approaches:Multi-stereo fusion and multi-view matching.While algorithms based on these two methodologies for multi-view image 3D reconstruction have reached relative maturity,no systematic comparison has been conducted specifically on satellite data to evaluate the relative merits of multi-stereo fusion versus multi-view matching methods.This paper conducts a comparative analysis of the practical accuracy of both approaches using high-resolution satellite datasets from diverse geographical regions.To ensure fairness in accuracy comparison,both methodologies employ non-local dense matching for cost optimization.Results demonstrate that the multi-stereo fusion method outperforms multi-view matching in all evaluation metrics,exhibiting approximately 1.2%higher average matching accuracy and 10.7%superior elevation precision in the experimental datasets.Therefore,for 3D modeling applications using satellite data,we recommend adopting the multi-stereo fusion approach for digital surface model(DSM)product generation.
基金Supported by the National Natural Science Foundation of China(62462036,62462037)Jiangxi Provincial Natural Science Foundation(20242BAB26017,20232BAB202010)+1 种基金Cultivation Project for Academic and Technical Leader in Major Disciplines in Jiangxi Province(20232BCJ22013)the Jiangxi Province Graduate Innovation Found Project(YC2024-S214)。
文摘Most existing multi-pattern matching algorithms are designed for single English texts leading to issues such as missed matches and space expansion when applied to Chinese-English mixed-text environments.The Hash Trie-based matching machine demonstrates strong compatibility with both Chinese and English,ensuring high accuracy in text processing and subtree positioning.In this study,a novel functional framework based on the HashTrie structure is proposed and mechanically verified using Isabelle/HOL.This framework is applied to design Functional Multi-Pattern Matching(FMPM),the first functional multi-pattern matching algorithm for Chinese-English mixed texts.FMPM constructs the HashTrie matching machine using character codes and threads the machine according to the associations between pattern strings.The experimental results show that as the stored string information increases,the proposed algorithm demonstrates more significant optimization in retrieval efficiency.FMPM simplifies the implementation of the Threaded Hash Trie(THT)for Chinese-English mixed texts,effectively reducing the uncertainties in the transition from the algorithm description to code implementation.FMPM addresses the problem of space explosion Chinese-English mixed texts and avoids issues such as bound variable iteration errors.The functional framework of the HashTrie structure serves as a reference for the formal verification of future HashTrie-based algorithms.
文摘With the rapid development of online education,the impact of interface design on learning experience has become increasingly prominent.Reasonable color matching can effectively improve learning efficiency,enhance user engagement,and improve visual experience.This paper analyzes the application of color matching in interface design,discusses the principle of color matching in online course interfaces,and puts forward some design strategies.It provides a practical reference for the interface design of an online education platform.
文摘This study systematically analyzes the influence mechanism of psychological factors on the competition performance of badminton athletes in capital universities through the recent actual participation of university teams in college badminton matches and combined with high-quality literature.The study finds that anxiety,self-efficacy,and factors from audiences and referees are the main influencing variables,and significant gender differences exist.Based on the empirical research results,a psychological intervention program combining mindfulness training,virtual reality technology,and biofeedback training is proposed to provide a scientific basis for psychological training of college badminton athletes.
基金funded by the State Grid Hebei Electric Power Company(Project Number:KJ2023-093).
文摘Session-based recommendation systems(SBR)are pivotal in suggesting items by analyzing anonymized sequences of user interactions.Traditional methods,while competent,often fall short in two critical areas:they fail to address potential inter-session item transitions,which are behavioral dependencies that extend beyond individual session boundaries,and they rely on monolithic item aggregation to construct session representations.This approach does not capture the multi-scale and heterogeneous nature of user intent,leading to a decrease in modeling accuracy.To overcome these limitations,a novel approach called HMGS has been introduced.This system incorporates dual graph architectures to enhance the recommendation process.A global transition graph captures latent cross-session item dependencies,while a heterogeneous intra-session graph encodesmulti-scale item embeddings through localized feature propagation.Additionally,amulti-tier graphmatchingmechanism aligns user preference signals across different granularities,significantly improving interest localization accuracy.Empirical validation on benchmark datasets(Tmall and Diginetica)confirms HMGS’s efficacy against state-of-the-art baselines.Quantitative analysis reveals performance gains of 20.54%and 12.63%in Precision@10 on Tmall and Diginetica,respectively.Consistent improvements are observed across auxiliary metrics,with MRR@10,Precision@20,and MRR@20 exhibiting enhancements between 4.00%and 21.36%,underscoring the framework’s robustness in multi-faceted recommendation scenarios.
文摘In this study,the wave motion in elastodynamics for unbounded media is modeled using an unsplit-field perfectly matched layer(PML)formulation that is solved by employing an isogeometric analysis(IGA).In the adopted combination,the non-uniform rational B-spline(NURBS)functions are employed as basis functions.Moreover,the unbounded and artificial domains,defined in the PML method,are contained in a single patch domain.Based on the proposed scheme,the approximation of the geometry problem is set in a new scheme in which the PML’s absorbing and attenuation properties and the description of traveling waves can be represented.This includes a higher continuity and smoother approximation of the computed domain.As high-order NURBS basis functions are non-interpolatory,a penalty method is present to apply a time-dependent displacement load.The performance of the NURBS-based PML is analyzed through numerical examples for 1D and 2D domains,considering homogeneous and heterogeneous media.Further,we verify the long-time numerical stability of the present method.The developed method can be used to simulate hypothetical stratified domains commonly encountered in soil-structure interaction analyses.
基金Sponsored by the National Key Research and Development Program from Ministry of Science and Technology of the People's Republic of China (Grant No.2020YFB1711403)。
文摘After the design of aerospace products is completed,a manufacturability assessment needs to be conducted based on 3D model's features in terms of modeling quality and process design,otherwise the cost of design changes will increase.Due to the poor structure and low reusability of product manufacturing feature information and assessment knowledge in the current aerospace product manufacturability assessment process,it is difficult to realize automated manufacturability assessment.To address these issues,a domain ontology model is established for aerospace product manufacturability assessment in this paper.On this basis,a structured representation method of manufacturability assessment knowledge and a knowledge graph data layer construction method are proposed.Based on the semantic information and association information expressed by the knowledge graph,a rule matching method based on subgraph matching is proposed to improve the precision and recall.Finally,applications and experiments based on the software platform verify the effectiveness of the proposed knowledge graph construction and rule matching method.
基金the Study on Vaccine Application Evaluation Strategies and Capacity Building (INV-006373)the National Key R&D Program of China(2024YFC2310604)
文摘Objective The objective of our study was to evaluate the vaccine effectiveness(VE)of the pentavalent rotavirus vaccine(RV5)among<5-year-old children in three provinces of China during 2020-2024 via a propensity score-matched test-negative case-control study.Methods Electronic health records and immunization information systems were used to obtain data on acute gastroenteritis(AGE)cases tested for rotavirus(RV)infection.RV-positive cases were propensity score matched with RV-negative controls for age,visit month,and province.Results The study included 27,472 children with AGE aged 8 weeks to 4 years at the time of AGE diagnosis;7.98%(2,192)were RV-positive.The VE(95%confidence interval,CI)of 1-2 and 3 doses of RV5 against any medically attended RV infection(inpatient or outpatient)was 57.6%(39.8%,70.2%)and 67.2%(60.3%,72.9%),respectively.Among children who received the 3rd dose before turning 5 months of age,3-dose VE decreased from 70.4%(53.9%,81.1%)(<5 months since the 3rd dose)to 63.0%(49.1%,73.0%)(≥1 year since the 3rd dose).The three-dose VE rate was 69.4%(41.3%,84.0%)for RVGE hospitalization and 57.5%(38.9%,70.5%)for outpatient-only medically attended RVGE.Conclusion Three-dose RV5 VE against rotavirus gastroenteritis(RVGE)in children aged<5 years was higher than 1-2-dose VE.Three-dose VE decreased with time since the 3rd dose in children who received the 3rd dose before turning five months of age,but remained above 60%for at least one year.VE was higher for RVGE hospitalizations than for medically attended outpatient visits.
文摘AIM:To compare analysis of the impact of high altitude on corneal endothelial cells,and the prognosis in patients with cataract surgeries.METHODS:Totally 265 plateau patients with cataract surgeries performed between January 2019 and July 2022(average altitude=3000 m),and 524 plain patients with cataract surgeries performed between January 2020 and July 2022 were included.The propensity score matching(PSM)method was applied to match the basic information of patients in both regions on a 1:1 basis.Corneal endothelial cell density(ECD),coefficient of variation(CV),hexagonal cell ratio(HEX),duration of surgery,and pre-and postoperative visual acuity(VA)were compared retrospectively,and correlation tests were done.RESULTS:Totally 223 pairs have been matched successfully.The HEX in the plateau group was higher than that in the plain group(61.95%±6.191%vs 44.91%±6.829%,P<0.001).For ECD and CV,no significant differences were observed between both groups(P>0.1).The pre-and postoperative VA of patients with cataract surgeries in the plateau group were lower(1.40±0.610 vs 0.71±0.514,P<0.001&0.68±0.479 vs 0.18±0.259,P<0.001),and the duration of surgery was longer than those in the plain group(27.06±14.900 min vs 16.03±8.033 min,P<0.001).No significant associations were found between the post-operative VA and the corneal endothelial parameters(P>0.05),while the post-operative VA was significantly related to the pre-operative VA and the duration of surgery(P<0.05).CONCLUSION:The relative hypoxic environment of the plateau does not promote the apoptosis of corneal endothelial cells,but may lead to the compensatory increase of their functions.In plateau patients,no significant associations are found between the poor VA and the corneal endothelial functions early after cataract surgeries.
文摘The cross-modal person re-identification task aims to match visible and infrared images of the same individual.The main challenges in this field arise from significant modality differences between individuals and the lack of high-quality cross-modal correspondence methods.Existing approaches often attempt to establish modality correspondence by extracting shared features across different modalities.However,these methods tend to focus on local information extraction and fail to fully leverage the global identity information in the cross-modal features,resulting in limited correspondence accuracy and suboptimal matching performance.To address this issue,we propose a quadratic graph matching method designed to overcome the challenges posed by modality differences through precise cross-modal relationship alignment.This method transforms the cross-modal correspondence problem into a graph matching task and minimizes the matching cost using a center search mechanism.Building on this approach,we further design a block reasoning module to uncover latent relationships between person identities and optimize the modality correspondence results.The block strategy not only improves the efficiency of updating gallery images but also enhances matching accuracy while reducing computational load.Experimental results demonstrate that our proposed method outperforms the state-of-the-art methods on the SYSU-MM01,RegDB,and RGBNT201 datasets,achieving excellent matching accuracy and robustness,thereby validating its effectiveness in cross-modal person re-identification.
