Magnesium materials have attracted the attention of many researchers,and the related research is expanding.This article summarizes the advance in the research and development of magnesium materials globally in 2023 fr...Magnesium materials have attracted the attention of many researchers,and the related research is expanding.This article summarizes the advance in the research and development of magnesium materials globally in 2023 from bibliometric and scientific perspectives.More than 4680 articles on Mg and its alloys were published and indexed in the Web of Science(WoS)Core Collection database last year.The bibliometric analyses show that the traditional structural Mg alloys,functional Mg materials,and corrosion and protection of Mg alloys are still the main research focus.Therefore,this review paper mainly focuses on the research progress of Mg cast alloys,Mg wrought alloys,bio-magnesium alloys,Mg-based energy storage materials,corrosion and protection of Mg alloys in 2023.In addition,future research directions are proposed based on the challenges and obstacles identified throughout this review.展开更多
Feature matching plays a key role in computer vision. However, due to the limitations of the descriptors, the putative matches are inevitably contaminated by massive outliers.This paper attempts to tackle the outlier ...Feature matching plays a key role in computer vision. However, due to the limitations of the descriptors, the putative matches are inevitably contaminated by massive outliers.This paper attempts to tackle the outlier filtering problem from two aspects. First, a robust and efficient graph interaction model,is proposed, with the assumption that matches are correlated with each other rather than independently distributed. To this end, we construct a graph based on the local relationships of matches and formulate the outlier filtering task as a binary labeling energy minimization problem, where the pairwise term encodes the interaction between matches. We further show that this formulation can be solved globally by graph cut algorithm. Our new formulation always improves the performance of previous localitybased method without noticeable deterioration in processing time,adding a few milliseconds. Second, to construct a better graph structure, a robust and geometrically meaningful topology-aware relationship is developed to capture the topology relationship between matches. The two components in sum lead to topology interaction matching(TIM), an effective and efficient method for outlier filtering. Extensive experiments on several large and diverse datasets for multiple vision tasks including general feature matching, as well as relative pose estimation, homography and fundamental matrix estimation, loop-closure detection, and multi-modal image matching, demonstrate that our TIM is more competitive than current state-of-the-art methods, in terms of generality, efficiency, and effectiveness. The source code is publicly available at http://github.com/YifanLu2000/TIM.展开更多
More than 4600 papers in the field of Mg and Mg alloys were published and indexed in the Web of Science(WoS)Core Collection database in 2022.The bibliometric analyses indicate that the microstructure,mechanical proper...More than 4600 papers in the field of Mg and Mg alloys were published and indexed in the Web of Science(WoS)Core Collection database in 2022.The bibliometric analyses indicate that the microstructure,mechanical properties,and corrosion of Mg alloys are still the main research focus.Bio-Mg materials,Mg ion batteries and hydrogen storage Mg materials have attracted much attention.Notable contributions to the research and development of magnesium alloys were made by Chongqing University(>200 papers),Chinese Academy of Sciences,Shanghai Jiao Tong University,and Northeastern University(>100 papers)in China,Helmholtz Zentrum Hereon in Germany,Ohio State University in the USA,the University of Queensland in Australia,Kumanto University in Japan,and Seoul National University in Korea,University of Tehran in Iran,and National University of Singapore in Singapore,etc.This review is aimed to summarize the progress in the development of structural and functional Mg and Mg alloys in 2022.Based on the issues and challenges identified here,some future research directions are suggested.展开更多
The fundamental research on thermo-mechanical conditions provides an experimental basis for high-performance Mg-Al-Ca-Mn alloys.However, there is a lack of systematical investigation for this series alloys on the hot-...The fundamental research on thermo-mechanical conditions provides an experimental basis for high-performance Mg-Al-Ca-Mn alloys.However, there is a lack of systematical investigation for this series alloys on the hot-deformation kinetics and extrusion parameter optimization. Here, the flow behavior, constitutive model, dynamic recrystallization(DRX) kinetic model and processing map of a dilute rare-earth free Mg-1.3Al-0.4Ca-0.4Mn(AXM100, wt.%) alloy were studied under different hot-compressive conditions. In addition, the extrusion parameter optimization of this alloy was performed based on the hot-processing map. The results showed that the conventional Arrhenius-type strain-related constitutive model only worked well for the flow curves at high temperatures and low strain rates. In comparison, using the machine learning assisted model(support vector regression, SVR) could effectively improve the accuracy between the predicted and experimental values. The DRX kinetic model was established, and a typical necklace-shaped structure preferentially occurred at the original grain boundaries and the second phases. The DRX nucleation weakened the texture intensity, and the further growth caused the more scattered basal texture. The hot-processing maps at different strains were also measured and the optimal hot-processing range could be confirmed at the deformation temperatures of 600~723 K and the strain rates of 0.018~0.563 s^(-1). Based on the optimum hot-processing range, a suitable extrusion parameter was considered as 603 K and 0.1 mm/s and the as-extruded alloy in this parameter exhibited a good strength-ductility synergy(yield strength of ~ 232.1 MPa, ultimate strength of ~ 278.2 MPa and elongation-to-failure of ~ 20.1%). Finally, the strengthening-plasticizing mechanisms and the relationships between the DRXed grain size, yield strength and extrusion parameters were analyzed.展开更多
Nowadays Surveying and Mapping(S&M)production and services are facing some serious challenges such as real-timization of data acquisition,automation of information processing,and intellectualization of service app...Nowadays Surveying and Mapping(S&M)production and services are facing some serious challenges such as real-timization of data acquisition,automation of information processing,and intellectualization of service applications.The main reason is that current digitalized S&M technologies,which involve complex algorithms and models as the core,are incapable of completely describing and representing the diverse,multi-dimensional and dynamic real world,as well as addressing high-dimensional and nonlinear spatial problems using simple algorithms and models.In order to address these challenges,it is necessary to explore the use of natural intelligence in S&M,and to develop intelligentized S&M technologies,which are knowledge-guided and algorithm-based.This paper first discusses the basic concepts and ideas of intelligentized S&M,and then analyzes and defines its fundamental issues in the analysis and modeling of natural intelligence in S&M,the construction and realization of hybrid intelligent computing paradigm,and the mechanism and path of empowering production.Further research directions are then proposed in the four areas,including knowledge systems,technologies and methodologies,application systems,and instruments and equipments of intelligentized S&M.Finally,some institutional issues related to promoting scientific research and engineering applications in this area are discussed.展开更多
The effects of the base material(BM)location on the mechanical properties and the exfoliation corrosion performance of friction-stir-welded(FSWed)dissimilar 2024-to-5083 aluminum alloy joints were investigated.Scannin...The effects of the base material(BM)location on the mechanical properties and the exfoliation corrosion performance of friction-stir-welded(FSWed)dissimilar 2024-to-5083 aluminum alloy joints were investigated.Scanning electron microscopy(SEM),electron backscatter diffraction(EBSD),transmission electron microscopy(TEM),tensile tests and electrochemical experiments were conducted.The results revealed that the BM location had little effect on the tensile properties of the joints.The grain orientation spread(GOS)value of 2024 alloy side was lower than that of 5083 alloy side.Intergranular corrosion occurred mainly on the 2024 alloy side,while the grain interior of the 5083 alloy side was corroded due to the higher GOS value and dislocation density.The FSWed dissimilar joints with a superior exfoliation corrosion resistance could be achieved when the 5083 aluminum alloy with better corrosion performance was positioned on the retreating side.展开更多
This article asks whether a regional security community has emerged in Asia with the potential to grow mature and seeks to make a contribution to the ongoing debate on this controversial topic.It advances the argument...This article asks whether a regional security community has emerged in Asia with the potential to grow mature and seeks to make a contribution to the ongoing debate on this controversial topic.It advances the argument that states in this broad region are far from being able to develop a security community for reasons different from those provided by political realists,developmental statists,liberals,and constructivists(social,discursive,and emancipationist).The role of Association of Southeast Asia(ASEAN)and that of China provide excellent test cases for the theoretical proposition that the building of a successful regional security community requires at least two necessary conditions:liberal democracy and regional democratic leadership,which remain absent in Asia.展开更多
This research paper presents a comprehensive discrete element method(DEM)examination of the mixing behaviors exhibited by cohesive particles within a twin-paddle blender.A comparative analysis between the simulation a...This research paper presents a comprehensive discrete element method(DEM)examination of the mixing behaviors exhibited by cohesive particles within a twin-paddle blender.A comparative analysis between the simulation and experimental results revealed a relative error of 3.47%,demonstrating a strong agreement between the results from the experimental tests and the DEM simulation.The main focus centers on systematically exploring how operational parameters,such as impeller rotational speed,blender's fill level,and particle mass ratio,influence the process.The investigation also illustrates the significant influence of the mixing time on the mixing quality.To gain a deeper understanding of the DEM simulation findings,an analytical tool called multivariate polynomial regression in machine learning is employed.This method uncovers significant connections between the DEM results and the operational parameters,providing a more comprehensive insight into their interrelationships.The multivariate polynomial regression model exhibited robust predictive performance,with a mean absolute percentage error of less than 3%for both the training and validation sets,indicating a slight deviation from actual values.The model's precision was confirmed by low mean absolute error values of 0.0144(80%of the dataset in the training set)and 0.0183(20%of the dataset in the validation set).The study offers valuable insights into granular mixing behaviors,with implications for enhancing the efficiency and predictability of the mixing processes in various industrial applications.展开更多
The study considers issues of elaborating and validating a technique of autonomous vehicle motion planning based on sequential trajectory and speed optimization.This method includes components such as representing sou...The study considers issues of elaborating and validating a technique of autonomous vehicle motion planning based on sequential trajectory and speed optimization.This method includes components such as representing sought-for functions by finite elements(FE),vehicle kinematic model,sequential quadratic programming for nonlinear constrained optimization,and Gaussian N-point quadrature integration.The primary novelty consists of using the inverse approach for obtaining vehicle trajectory and speed.The curvature and speed are represented by integrated polynomials to reduce the number of unknowns.For this,piecewise functions with two and three degrees of freedom(DOF)are implemented through FE nodal parameters.The technique ensures higher differentiability compared to the needed in the geometric and kinematic equations.Thus,the generated reference curves are characterized by simple and unambiguous forms.The latter fits best the control accuracy and efficiency during the motion tracking phase.Another advantage is replacing the nodal linear equality constraints with integral nonlinear ones.This ensures the non-violation of boundary limits within each FE and not only in nodes.The optimization technique implies that the spatial and time variables must be found separately and staged.The trajectory search is accomplished in the restricted allowable zone composed by superposing an area inside the external and internal boundaries,based on keeping safe distances,excluding areas for moving obstacles.Thus,this study compares two models that use two and three nodal DOF on optimization quality,stability,and rapidity in real-time applications.The simulation example shows numerous graph results of geometric and kinematic parameters with smoothed curves up to the highest derivatives.Finally,the conclusions are made on the efficiency and quality of prognosis,outlining the similarities and differences between the two applied models.展开更多
The rapid evolution of Large Language Models(LLMs) highlights the necessity for ethical considerations and data integrity in AI development, particularly emphasizing the role of FAIR(Findable, Accessible, Interoperabl...The rapid evolution of Large Language Models(LLMs) highlights the necessity for ethical considerations and data integrity in AI development, particularly emphasizing the role of FAIR(Findable, Accessible, Interoperable, Reusable) data principles. While these principles are crucial for ethical data stewardship, their specific application in the context of LLM training data remains an under-explored area. This research gap is the focus of our study, which begins with an examination of existing literature to underline the importance of FAIR principles in managing data for LLM training. Building upon this, we propose a novel frame-work designed to integrate FAIR principles into the LLM development lifecycle. A contribution of our work is the development of a comprehensive checklist intended to guide researchers and developers in applying FAIR data principles consistently across the model development process. The utility and effectiveness of our frame-work are validated through a case study on creating a FAIR-compliant dataset aimed at detecting and mitigating biases in LLMs. We present this framework to the community as a tool to foster the creation of technologically advanced, ethically grounded, and socially responsible AI models.展开更多
The digital transformation process of power systems towards smart grids is resulting in improved reliability, efficiency and situational awareness at the expense of increased cybersecurity vulnerabilities. Given the a...The digital transformation process of power systems towards smart grids is resulting in improved reliability, efficiency and situational awareness at the expense of increased cybersecurity vulnerabilities. Given the availability of large volumes of smart grid data, machine learning-based methods are considered an effective way to improve cybersecurity posture. Despite the unquestionable merits of machine learning approaches for cybersecurity enhancement, they represent a component of the cyberattack surface that is vulnerable, in particular, to adversarial attacks. In this paper, we examine the robustness of autoencoder-based cyberattack detection systems in smart grids to adversarial attacks. A novel iterative-based method is first proposed to craft adversarial attack samples. Then, it is demonstrated that an attacker with white-box access to the autoencoder-based cyberattack detection systems can successfully craft evasive samples using the proposed method. The results indicate that naive initial adversarial seeds cannot be employed to craft successful adversarial attacks shedding insight on the complexity of designing adversarial attacks against autoencoder-based cyberattack detection systems in smart grids.展开更多
Increasingly harsh service conditions place higher requirements for the high strain-rate performance of titanium alloys.Adiabatic shear band(ASB),a phenomenon prone to dynamic loading,is often accom-panied by catastro...Increasingly harsh service conditions place higher requirements for the high strain-rate performance of titanium alloys.Adiabatic shear band(ASB),a phenomenon prone to dynamic loading,is often accom-panied by catastrophic damage.Yet,it is unclear how the internal nanostructures are related to shear instability.Here we report detailed microstructural evolution in the ASB of a titanium alloy via in-depth focused ion beam(FIB),transmission Kikuchi diffraction(TKD),and high-resolution transmission electron microscope(HRTEM)analyses,with the deformation instability phenomenon discussed from the energy perspective.The ASB interior undergoes multifaceted changes,namely deformation-induced beta-to-alpha transformation and deformation-induced martensitic transformation to form substantially refined and heterogeneous structures.Meanwhile,two types of extremely fine twins are identified to occur within both nano-sized martensite and alpha phase.The critical plastic work representing the onset of adiabatic shear instability and dynamic equilibrium is observed to be constant for a specific structure in the same deformation mode.The energy analysis could be extended to other materials subjected to high strain-rate dynamic deformation.展开更多
A low-alloyed Mg-1.2Zn-0.1Ca(wt.%)alloy was fabricated via low-temperature extrusion and annealing at 250℃for different times(10,30,and 90 min)to attain heterostructures with different fine-grained fractions,focusing...A low-alloyed Mg-1.2Zn-0.1Ca(wt.%)alloy was fabricated via low-temperature extrusion and annealing at 250℃for different times(10,30,and 90 min)to attain heterostructures with different fine-grained fractions,focusing on the effect of heterostructure on the mechanical properties.Partial dynamic recrystallization(RX)occurred during extrusion at 150℃,and a lamellar structure consisting of fine RX grains and coarse unRX grains was obtained.The subsequent annealing promoted static RX in the as-extruded alloy,leading to an increased fine-grained fraction from 67%to 95%.Meanwhile,the co-segregation of Zn and Ca atoms impeded the migration of grain boundaries,thus achieving a fine grain size of 0.8–1.6μm.The sample annealed for 10 min with a fine-grained fraction of 73%and an average RX grain size of 0.9μm exhibited a superior combination of high yield strength(305 MPa)and good ductility(20%).In comparison,an excellent elongation of 30%was achieved in the alloy with a nearly fully-RXed microstructure and an average grain size of 1.6μm after 90 min annealing,despite a lower yield strength of 228 MPa.In unRX grains,the hard orientation with(01–10)parallel to the extrusion direction and high-density dislocations made it more difficult to deform compared with the RX grains,thus producing hetero-deformation induced(HDI)strengthening.Besides fine grains and high-density dislocations,HDI strengthening is the key to achieving the superior mechanical properties of the low-alloyed Mg alloy.展开更多
Starting with a critique of so-called intercultural communication,the present paper contests and challenges the prevalent and dominant essentialist views of "culture".It is exposed that these views have a de...Starting with a critique of so-called intercultural communication,the present paper contests and challenges the prevalent and dominant essentialist views of "culture".It is exposed that these views have a detrimental underlying logic that is both destructive and self-destructive.Instead,the paper proposes a radically new idea of culture,a minimalist approach supported by insights gleaned from contemporary semiotic inquiry.In this approach,culture is defined as a biological instinct to acquire information through modeling,that is,learning by models.This instinct is at work,or is realized,in specific acts of such modeling,resulting in cultural practices and cultural artifacts.In the case of humanity,a cultural practice is anything a human does that can be modeled by another human and a cultural artifact is any object that humans make and can model.The paper argues it is imperative to keep in mind that when we deal with the "intercultural",we are only dealing with concrete yet different cultural practices or cultural artifacts.This is an effective way to completely refute essentialism.In a sense,the paper is meant to be a wake-up call,instead of a fighting talk.Its main objective is not to negate or obliterate the field of"intercultural communication",among others,but rather to save them from them-selvesa true and worthy field of"intercultural communication"is a field against essentialism,instead of an accessory to essentialism,whether the commission is"before the fact"or "after the fact".展开更多
The Ethereum blockchain’s smart contract is a programmable transaction that performs general-purpose computations and can be executed automatically on the blockchain.Leveraging this component,blockchain technology(BT...The Ethereum blockchain’s smart contract is a programmable transaction that performs general-purpose computations and can be executed automatically on the blockchain.Leveraging this component,blockchain technology(BT)has grown beyond the scope of cryptocurrencies and can now be applicable in various industries other than finance.In this paper,we investigated the current trends in Ethereum-based decentralized applications(DApps)to be able to categorize and analyze the DApps to measure the complexity of smart contracts behind them,their level of security and their correlation to the maintainability of the DApps.We leveraged the source code analysis,security analysis,and the developmental metadata of the DApps to infer this correlation.Based on our findings,we concluded that the maintainability of Ethereum DApps is proportional to the code size,number of functions,and,most importantly,the number of outgoing invocations and statements in the smart contracts.展开更多
Territory risk analysis has played an important role in the decision-making of auto insurance rate regulation.Due to the optimality of insurance loss data groupings,clustering methods become the natural choice for suc...Territory risk analysis has played an important role in the decision-making of auto insurance rate regulation.Due to the optimality of insurance loss data groupings,clustering methods become the natural choice for such territory risk classification.In this work,spatially constrained clustering is first applied to insurance loss data to form rating territories.The generalized linear model(GLM)and generalized linear mixed model(GLMM)are then proposed to derive the risk relativities of obtained clusters.Each basic rating unit within the same cluster,namely Forward Sortation Area(FSA),takes the same risk relativity value as its cluster.The obtained risk relativities from GLM or GLMM are used to calculate the performance metrics,including RMSE,MAD,and Gini coefficients.The spatially constrained clustering and the risk relativity estimate help obtain a set of territory risk benchmarks used in rate filings to guide the rate regulation process.展开更多
基金supported by the National Natural Science Foundation of China(Nos.52171104,52371093,52471117 and 52225101)the National Key Research and Development Program of China(No.2021YFB3701100).
文摘Magnesium materials have attracted the attention of many researchers,and the related research is expanding.This article summarizes the advance in the research and development of magnesium materials globally in 2023 from bibliometric and scientific perspectives.More than 4680 articles on Mg and its alloys were published and indexed in the Web of Science(WoS)Core Collection database last year.The bibliometric analyses show that the traditional structural Mg alloys,functional Mg materials,and corrosion and protection of Mg alloys are still the main research focus.Therefore,this review paper mainly focuses on the research progress of Mg cast alloys,Mg wrought alloys,bio-magnesium alloys,Mg-based energy storage materials,corrosion and protection of Mg alloys in 2023.In addition,future research directions are proposed based on the challenges and obstacles identified throughout this review.
基金supported by the National Natural Science Foundation of China (62276192)。
文摘Feature matching plays a key role in computer vision. However, due to the limitations of the descriptors, the putative matches are inevitably contaminated by massive outliers.This paper attempts to tackle the outlier filtering problem from two aspects. First, a robust and efficient graph interaction model,is proposed, with the assumption that matches are correlated with each other rather than independently distributed. To this end, we construct a graph based on the local relationships of matches and formulate the outlier filtering task as a binary labeling energy minimization problem, where the pairwise term encodes the interaction between matches. We further show that this formulation can be solved globally by graph cut algorithm. Our new formulation always improves the performance of previous localitybased method without noticeable deterioration in processing time,adding a few milliseconds. Second, to construct a better graph structure, a robust and geometrically meaningful topology-aware relationship is developed to capture the topology relationship between matches. The two components in sum lead to topology interaction matching(TIM), an effective and efficient method for outlier filtering. Extensive experiments on several large and diverse datasets for multiple vision tasks including general feature matching, as well as relative pose estimation, homography and fundamental matrix estimation, loop-closure detection, and multi-modal image matching, demonstrate that our TIM is more competitive than current state-of-the-art methods, in terms of generality, efficiency, and effectiveness. The source code is publicly available at http://github.com/YifanLu2000/TIM.
基金This work was financially supported by the National Key Research and Development Program of China(No.2021YFB3701100)the National Natural Science Foundation of China(Nos.52171104 and U20A20234)+1 种基金the Chongqing Research Program of Basic Research and Frontier Technology,China(Nos.cstc2021ycjh-bgzxm0086 and 2019jcyj-msxmX0306)the fundamental Research funds for Central Universities,China(Nos.SKLMT-ZZKT-2022R04,2021CDJJMRH-001,and SKLMT-ZZKT-2022M12).
文摘More than 4600 papers in the field of Mg and Mg alloys were published and indexed in the Web of Science(WoS)Core Collection database in 2022.The bibliometric analyses indicate that the microstructure,mechanical properties,and corrosion of Mg alloys are still the main research focus.Bio-Mg materials,Mg ion batteries and hydrogen storage Mg materials have attracted much attention.Notable contributions to the research and development of magnesium alloys were made by Chongqing University(>200 papers),Chinese Academy of Sciences,Shanghai Jiao Tong University,and Northeastern University(>100 papers)in China,Helmholtz Zentrum Hereon in Germany,Ohio State University in the USA,the University of Queensland in Australia,Kumanto University in Japan,and Seoul National University in Korea,University of Tehran in Iran,and National University of Singapore in Singapore,etc.This review is aimed to summarize the progress in the development of structural and functional Mg and Mg alloys in 2022.Based on the issues and challenges identified here,some future research directions are suggested.
基金funded by the Postgraduate Research & Practice Innovation Program of Jiangsu Province (No.SJCX22_1720)the National Natural Science Foundation of China (No.51901204)+1 种基金the Chongqing Science and Technology Commission (Nos.cstc2020jcyj-msxmX0184 and cstc2019jscx-mbdxX0031)the University Innovation Research Group of Chongqing (No.CXQT20023)。
文摘The fundamental research on thermo-mechanical conditions provides an experimental basis for high-performance Mg-Al-Ca-Mn alloys.However, there is a lack of systematical investigation for this series alloys on the hot-deformation kinetics and extrusion parameter optimization. Here, the flow behavior, constitutive model, dynamic recrystallization(DRX) kinetic model and processing map of a dilute rare-earth free Mg-1.3Al-0.4Ca-0.4Mn(AXM100, wt.%) alloy were studied under different hot-compressive conditions. In addition, the extrusion parameter optimization of this alloy was performed based on the hot-processing map. The results showed that the conventional Arrhenius-type strain-related constitutive model only worked well for the flow curves at high temperatures and low strain rates. In comparison, using the machine learning assisted model(support vector regression, SVR) could effectively improve the accuracy between the predicted and experimental values. The DRX kinetic model was established, and a typical necklace-shaped structure preferentially occurred at the original grain boundaries and the second phases. The DRX nucleation weakened the texture intensity, and the further growth caused the more scattered basal texture. The hot-processing maps at different strains were also measured and the optimal hot-processing range could be confirmed at the deformation temperatures of 600~723 K and the strain rates of 0.018~0.563 s^(-1). Based on the optimum hot-processing range, a suitable extrusion parameter was considered as 603 K and 0.1 mm/s and the as-extruded alloy in this parameter exhibited a good strength-ductility synergy(yield strength of ~ 232.1 MPa, ultimate strength of ~ 278.2 MPa and elongation-to-failure of ~ 20.1%). Finally, the strengthening-plasticizing mechanisms and the relationships between the DRXed grain size, yield strength and extrusion parameters were analyzed.
基金The Key Program of the National Natural Science Foundation of China(No.41930650)The Strategic Consulting Project of Chinese Academy of Engineering(No.2019-ZD-16)。
文摘Nowadays Surveying and Mapping(S&M)production and services are facing some serious challenges such as real-timization of data acquisition,automation of information processing,and intellectualization of service applications.The main reason is that current digitalized S&M technologies,which involve complex algorithms and models as the core,are incapable of completely describing and representing the diverse,multi-dimensional and dynamic real world,as well as addressing high-dimensional and nonlinear spatial problems using simple algorithms and models.In order to address these challenges,it is necessary to explore the use of natural intelligence in S&M,and to develop intelligentized S&M technologies,which are knowledge-guided and algorithm-based.This paper first discusses the basic concepts and ideas of intelligentized S&M,and then analyzes and defines its fundamental issues in the analysis and modeling of natural intelligence in S&M,the construction and realization of hybrid intelligent computing paradigm,and the mechanism and path of empowering production.Further research directions are then proposed in the four areas,including knowledge systems,technologies and methodologies,application systems,and instruments and equipments of intelligentized S&M.Finally,some institutional issues related to promoting scientific research and engineering applications in this area are discussed.
基金financial supports from the National Natural Science Foundation of China (No.52105357)the Natural Sciences and Engineering Research Council of Canada (NSERC) in the form of international research collaboration,the Natural Science Foundation for Youth of Jiangxi Education Department,China (No.DA202003181)+1 种基金the Foundation of National Defense Key Disciplines Laboratory of Light Alloy Processing Science and Technology of China (No.EG202103420)the Doctor Starting Foundation of Nanchang Hangkong University,China (No.EA202003208)。
文摘The effects of the base material(BM)location on the mechanical properties and the exfoliation corrosion performance of friction-stir-welded(FSWed)dissimilar 2024-to-5083 aluminum alloy joints were investigated.Scanning electron microscopy(SEM),electron backscatter diffraction(EBSD),transmission electron microscopy(TEM),tensile tests and electrochemical experiments were conducted.The results revealed that the BM location had little effect on the tensile properties of the joints.The grain orientation spread(GOS)value of 2024 alloy side was lower than that of 5083 alloy side.Intergranular corrosion occurred mainly on the 2024 alloy side,while the grain interior of the 5083 alloy side was corroded due to the higher GOS value and dislocation density.The FSWed dissimilar joints with a superior exfoliation corrosion resistance could be achieved when the 5083 aluminum alloy with better corrosion performance was positioned on the retreating side.
文摘This article asks whether a regional security community has emerged in Asia with the potential to grow mature and seeks to make a contribution to the ongoing debate on this controversial topic.It advances the argument that states in this broad region are far from being able to develop a security community for reasons different from those provided by political realists,developmental statists,liberals,and constructivists(social,discursive,and emancipationist).The role of Association of Southeast Asia(ASEAN)and that of China provide excellent test cases for the theoretical proposition that the building of a successful regional security community requires at least two necessary conditions:liberal democracy and regional democratic leadership,which remain absent in Asia.
基金the Natural Sciences and Engineering Research Council of Canada(grant No.RGPIN-2019-04644)is gratefully acknowledged.
文摘This research paper presents a comprehensive discrete element method(DEM)examination of the mixing behaviors exhibited by cohesive particles within a twin-paddle blender.A comparative analysis between the simulation and experimental results revealed a relative error of 3.47%,demonstrating a strong agreement between the results from the experimental tests and the DEM simulation.The main focus centers on systematically exploring how operational parameters,such as impeller rotational speed,blender's fill level,and particle mass ratio,influence the process.The investigation also illustrates the significant influence of the mixing time on the mixing quality.To gain a deeper understanding of the DEM simulation findings,an analytical tool called multivariate polynomial regression in machine learning is employed.This method uncovers significant connections between the DEM results and the operational parameters,providing a more comprehensive insight into their interrelationships.The multivariate polynomial regression model exhibited robust predictive performance,with a mean absolute percentage error of less than 3%for both the training and validation sets,indicating a slight deviation from actual values.The model's precision was confirmed by low mean absolute error values of 0.0144(80%of the dataset in the training set)and 0.0183(20%of the dataset in the validation set).The study offers valuable insights into granular mixing behaviors,with implications for enhancing the efficiency and predictability of the mixing processes in various industrial applications.
基金supported by the Natural Sciences and Engineering Research Council of Canada(RGPIN-2020-04667).
文摘The study considers issues of elaborating and validating a technique of autonomous vehicle motion planning based on sequential trajectory and speed optimization.This method includes components such as representing sought-for functions by finite elements(FE),vehicle kinematic model,sequential quadratic programming for nonlinear constrained optimization,and Gaussian N-point quadrature integration.The primary novelty consists of using the inverse approach for obtaining vehicle trajectory and speed.The curvature and speed are represented by integrated polynomials to reduce the number of unknowns.For this,piecewise functions with two and three degrees of freedom(DOF)are implemented through FE nodal parameters.The technique ensures higher differentiability compared to the needed in the geometric and kinematic equations.Thus,the generated reference curves are characterized by simple and unambiguous forms.The latter fits best the control accuracy and efficiency during the motion tracking phase.Another advantage is replacing the nodal linear equality constraints with integral nonlinear ones.This ensures the non-violation of boundary limits within each FE and not only in nodes.The optimization technique implies that the spatial and time variables must be found separately and staged.The trajectory search is accomplished in the restricted allowable zone composed by superposing an area inside the external and internal boundaries,based on keeping safe distances,excluding areas for moving obstacles.Thus,this study compares two models that use two and three nodal DOF on optimization quality,stability,and rapidity in real-time applications.The simulation example shows numerous graph results of geometric and kinematic parameters with smoothed curves up to the highest derivatives.Finally,the conclusions are made on the efficiency and quality of prognosis,outlining the similarities and differences between the two applied models.
文摘The rapid evolution of Large Language Models(LLMs) highlights the necessity for ethical considerations and data integrity in AI development, particularly emphasizing the role of FAIR(Findable, Accessible, Interoperable, Reusable) data principles. While these principles are crucial for ethical data stewardship, their specific application in the context of LLM training data remains an under-explored area. This research gap is the focus of our study, which begins with an examination of existing literature to underline the importance of FAIR principles in managing data for LLM training. Building upon this, we propose a novel frame-work designed to integrate FAIR principles into the LLM development lifecycle. A contribution of our work is the development of a comprehensive checklist intended to guide researchers and developers in applying FAIR data principles consistently across the model development process. The utility and effectiveness of our frame-work are validated through a case study on creating a FAIR-compliant dataset aimed at detecting and mitigating biases in LLMs. We present this framework to the community as a tool to foster the creation of technologically advanced, ethically grounded, and socially responsible AI models.
文摘The digital transformation process of power systems towards smart grids is resulting in improved reliability, efficiency and situational awareness at the expense of increased cybersecurity vulnerabilities. Given the availability of large volumes of smart grid data, machine learning-based methods are considered an effective way to improve cybersecurity posture. Despite the unquestionable merits of machine learning approaches for cybersecurity enhancement, they represent a component of the cyberattack surface that is vulnerable, in particular, to adversarial attacks. In this paper, we examine the robustness of autoencoder-based cyberattack detection systems in smart grids to adversarial attacks. A novel iterative-based method is first proposed to craft adversarial attack samples. Then, it is demonstrated that an attacker with white-box access to the autoencoder-based cyberattack detection systems can successfully craft evasive samples using the proposed method. The results indicate that naive initial adversarial seeds cannot be employed to craft successful adversarial attacks shedding insight on the complexity of designing adversarial attacks against autoencoder-based cyberattack detection systems in smart grids.
基金supported by the National Natural Science Foundation of China (NSFC) (Nos.51871168,52271012)the Natural Sciences and Engineering Research Council of Canada (NSERC)in the form of international research collaboration.Q.C.,A.H.F.,and S.J.Q.are grateful to the Southwest Institute of Technology and Engineering Cooperation Fund (No.HDHDW5902020102)H.W.acknowledges the financial support of the National Key Laboratory Foundation of Science and Technology on Materials under Shock and Impact (No.6142902220301).
文摘Increasingly harsh service conditions place higher requirements for the high strain-rate performance of titanium alloys.Adiabatic shear band(ASB),a phenomenon prone to dynamic loading,is often accom-panied by catastrophic damage.Yet,it is unclear how the internal nanostructures are related to shear instability.Here we report detailed microstructural evolution in the ASB of a titanium alloy via in-depth focused ion beam(FIB),transmission Kikuchi diffraction(TKD),and high-resolution transmission electron microscope(HRTEM)analyses,with the deformation instability phenomenon discussed from the energy perspective.The ASB interior undergoes multifaceted changes,namely deformation-induced beta-to-alpha transformation and deformation-induced martensitic transformation to form substantially refined and heterogeneous structures.Meanwhile,two types of extremely fine twins are identified to occur within both nano-sized martensite and alpha phase.The critical plastic work representing the onset of adiabatic shear instability and dynamic equilibrium is observed to be constant for a specific structure in the same deformation mode.The energy analysis could be extended to other materials subjected to high strain-rate dynamic deformation.
基金the Key-Area Research and Development Program of Guangdong Province(No.2020B010186002)the Natural Science Foundation of Guangdong for Research Team(No.2015A030312003)。
文摘A low-alloyed Mg-1.2Zn-0.1Ca(wt.%)alloy was fabricated via low-temperature extrusion and annealing at 250℃for different times(10,30,and 90 min)to attain heterostructures with different fine-grained fractions,focusing on the effect of heterostructure on the mechanical properties.Partial dynamic recrystallization(RX)occurred during extrusion at 150℃,and a lamellar structure consisting of fine RX grains and coarse unRX grains was obtained.The subsequent annealing promoted static RX in the as-extruded alloy,leading to an increased fine-grained fraction from 67%to 95%.Meanwhile,the co-segregation of Zn and Ca atoms impeded the migration of grain boundaries,thus achieving a fine grain size of 0.8–1.6μm.The sample annealed for 10 min with a fine-grained fraction of 73%and an average RX grain size of 0.9μm exhibited a superior combination of high yield strength(305 MPa)and good ductility(20%).In comparison,an excellent elongation of 30%was achieved in the alloy with a nearly fully-RXed microstructure and an average grain size of 1.6μm after 90 min annealing,despite a lower yield strength of 228 MPa.In unRX grains,the hard orientation with(01–10)parallel to the extrusion direction and high-density dislocations made it more difficult to deform compared with the RX grains,thus producing hetero-deformation induced(HDI)strengthening.Besides fine grains and high-density dislocations,HDI strengthening is the key to achieving the superior mechanical properties of the low-alloyed Mg alloy.
文摘Starting with a critique of so-called intercultural communication,the present paper contests and challenges the prevalent and dominant essentialist views of "culture".It is exposed that these views have a detrimental underlying logic that is both destructive and self-destructive.Instead,the paper proposes a radically new idea of culture,a minimalist approach supported by insights gleaned from contemporary semiotic inquiry.In this approach,culture is defined as a biological instinct to acquire information through modeling,that is,learning by models.This instinct is at work,or is realized,in specific acts of such modeling,resulting in cultural practices and cultural artifacts.In the case of humanity,a cultural practice is anything a human does that can be modeled by another human and a cultural artifact is any object that humans make and can model.The paper argues it is imperative to keep in mind that when we deal with the "intercultural",we are only dealing with concrete yet different cultural practices or cultural artifacts.This is an effective way to completely refute essentialism.In a sense,the paper is meant to be a wake-up call,instead of a fighting talk.Its main objective is not to negate or obliterate the field of"intercultural communication",among others,but rather to save them from them-selvesa true and worthy field of"intercultural communication"is a field against essentialism,instead of an accessory to essentialism,whether the commission is"before the fact"or "after the fact".
文摘The Ethereum blockchain’s smart contract is a programmable transaction that performs general-purpose computations and can be executed automatically on the blockchain.Leveraging this component,blockchain technology(BT)has grown beyond the scope of cryptocurrencies and can now be applicable in various industries other than finance.In this paper,we investigated the current trends in Ethereum-based decentralized applications(DApps)to be able to categorize and analyze the DApps to measure the complexity of smart contracts behind them,their level of security and their correlation to the maintainability of the DApps.We leveraged the source code analysis,security analysis,and the developmental metadata of the DApps to infer this correlation.Based on our findings,we concluded that the maintainability of Ethereum DApps is proportional to the code size,number of functions,and,most importantly,the number of outgoing invocations and statements in the smart contracts.
文摘Territory risk analysis has played an important role in the decision-making of auto insurance rate regulation.Due to the optimality of insurance loss data groupings,clustering methods become the natural choice for such territory risk classification.In this work,spatially constrained clustering is first applied to insurance loss data to form rating territories.The generalized linear model(GLM)and generalized linear mixed model(GLMM)are then proposed to derive the risk relativities of obtained clusters.Each basic rating unit within the same cluster,namely Forward Sortation Area(FSA),takes the same risk relativity value as its cluster.The obtained risk relativities from GLM or GLMM are used to calculate the performance metrics,including RMSE,MAD,and Gini coefficients.The spatially constrained clustering and the risk relativity estimate help obtain a set of territory risk benchmarks used in rate filings to guide the rate regulation process.
