During the critical transformation period of landscape architecture major after the adjustment of disciplinary structure and the changes in market demand,private colleges and universities,as important places for culti...During the critical transformation period of landscape architecture major after the adjustment of disciplinary structure and the changes in market demand,private colleges and universities,as important places for cultivating local talents,have pain points such as uneven quality of teachers and students and weak innovation and practice.The practice system with“multi-dimensional Integration”integrates four dimensions:interdisciplinary integration,spatial and temporal intersection,historical inheritance,and behavioral activity,deepens the disciplinary connotation,and integrates the three elements of nature,humanity,and technology,aiming to provide a new path for private colleges and universities to cultivate application-oriented and compound talents with innovative capabilities.In terms of optimizing talent cultivation and adapting to industry changes,this system provides thinking and reference for landscape architecture major,helping the major reshape its core competitiveness and promoting educational innovation and industry development.展开更多
Particulate-reinforced metal matrix composites(PRMMCs)are difficult to machine due to the inclusion of hard,brittle reinforcing particles.Existing experimental investigations rarely reveal the complex material removal...Particulate-reinforced metal matrix composites(PRMMCs)are difficult to machine due to the inclusion of hard,brittle reinforcing particles.Existing experimental investigations rarely reveal the complex material removal mechanisms(MRMs)involved in the machining of PRMMCs.This paper develops a three-dimensional(3D)microstructure-based model for investigating the MRM and surface integrity of machined PRMMCs.To accurately mimic the actual microstructure of a PRMMC,polyhedrons were randomly distributed inside the matrix to represent irregular SiC particles.Particle fracture and matrix deformation and failure were taken into account.For the model’s capability comparison,a two-dimensional(2D)analysis was also conducted.Relevant cutting experiments showed that the established 3D model accurately predicted the material removal,chip morphology,machined surface finish,and cutting forces.It was found that the matrix-particle-tool interactions led to particle fractures,mainly in the primary shear and secondary deformation zones along the cutting path and beneath the machined surface.Particle fracture and dilodegment greatly influences the quality of a machined surface.It was also found that although a 2D model can reflect certain material removal features,its ability to predict microstructural variation is limited.展开更多
Given a set of requirements structured as design problems, we can apply design patterns to solve each problem individually. Much of the published literature on design patterns addresses this problem—pattern associati...Given a set of requirements structured as design problems, we can apply design patterns to solve each problem individually. Much of the published literature on design patterns addresses this problem—pattern association;however, there is no systematic and practical way that shows how to integrate those individual solutions together. We propose a compositional model based on design patterns by abstracting their behavioral model using role modeling constructs. This approach describes how to transform a design pattern into a role model that can be used to assemble a software application. The role model captures the behavioral relationship between participant components in the design pattern. Our approach offers a complete practical design and implementation strategies, adapted from DCI (Data, Context, and Interaction) architecture. We demonstrate our technique by presenting a simple case study complete with design and implementation code. We also present a simple to follow process that provides guidelines of what to do and how to do it.展开更多
This research extends ongoing efforts to develop methods for reinforcing damaged main gas pipelines to prevent catastrophic failure.This study establishes the use of scaled-down experimental models for assessing the d...This research extends ongoing efforts to develop methods for reinforcing damaged main gas pipelines to prevent catastrophic failure.This study establishes the use of scaled-down experimental models for assessing the dynamic strength of damaged pipeline sections reinforced with wire wrapping or composite sleeves.A generalized dynamic model is introduced for numerical simulation to evaluate the effectiveness of reinforcement techniques.The model incorporates the elastoplastic behavior of pipe and wire materials,the influence of temperature on mechanical properties,the contact interaction between the pipe and the reinforcement components(including pretensioning),and local material failure under transient internal pressure.Based on these parameters,a finite element model was developed using ANSYS 19.2 to enable parametric studies.The accuracy of the proposed model was verified by comparing the simulation results with the experimental findings.Pipeline section samples containing non-penetrating longitudinal crackswere subjected to comparative analyses and transient pressure until critical failure.The unreinforced and steel wire-wrapped sections were investigated.The results confirm the feasibility of applying the computational model to study the dynamic strength of reinforced damaged pipe sections.Furthermore,pipelines with longitudinal cracks reinforced using circular composite overlays with orthotropic mechanical properties were examined,and recommendations are provided for selecting the geometric parameters of such overlays.展开更多
近年来,复合材料层合板结构被广泛地应用于航空航天、军工、建筑工程等领域。但是,由于其几何尺寸的不准确性、材料参数的分散性、载荷环境的波动性等不确定性因素的影响,可能会对复合材料层合板结构的可靠性和安全性,以及系统的输出响...近年来,复合材料层合板结构被广泛地应用于航空航天、军工、建筑工程等领域。但是,由于其几何尺寸的不准确性、材料参数的分散性、载荷环境的波动性等不确定性因素的影响,可能会对复合材料层合板结构的可靠性和安全性,以及系统的输出响应产生重大影响。由于复合材料层合板的层间黏结不良、外部应力集中等因素,当复合材料层合板结构的能量释放速率达到层间断裂韧性时,就会发生分层。因此对复合材料层合板结构的分层可靠性进行分析具有重要的意义。目前,对于复合材料层合板结构的可靠性分析主要是采用一阶可靠性方法(first order reliability method,FORM)、二阶可靠性方法(second order reliability method,SORM)和重要性抽样方法(importance sampling,IS)等传统可靠性分析方法,并将其和蒙特卡罗模拟(Monte Carlo simulation,MCS)对比。但是,当复合材料结构不确定性维度高且复杂时,这些方法不仅计算效率太低,而且不能保证其计算精度。相比于传统的可靠性分析方法,可以利用基于自适应Kriging模型集成策略和主动学习函数结合蒙特卡罗模拟(adaptive Kriging-based Monte Carlo simulation,AK-MCS)的方法,对复合材料层合板结构进行可靠性分析。而直接概率积分方法(direct probability integral method,DPIM)具有更高的计算效率和精度,特别是对于高维度和复杂的可靠性分析问题。所以,本文采用AK-MCS方法和DPIM对模式Ⅰ、模式Ⅱ和混合Ⅰ/Ⅱ模式下的复合材料层合板结构分层的可靠度进行了研究。结果表明:DPIM和AK-MCS与传统可靠性分析方法相比具有更高的计算精度和计算效率,但是DPIM以其高效的计算效率脱颖而出,尽管其精度略低于AK-MCS,但在处理随机变量更多、非线性程度更高的混合Ⅰ/Ⅱ模式下的层合板结构分层的可靠性时展现出明显优势。综合考虑精度与时效性的平衡,DPIM能够准确地评估复合材料结构的可靠度,保障其在航天航空装备等领域的安全运行。展开更多
对于电力电子变换器、电机等控制对象模型明确的系统,提出1个由全状态反馈FSF(full state feedback)控制器和广义积分GI(generalized integrator)相结合的基于系统模型的复合控制策略。相较于比例-积分-微分PID(proportional-integral-d...对于电力电子变换器、电机等控制对象模型明确的系统,提出1个由全状态反馈FSF(full state feedback)控制器和广义积分GI(generalized integrator)相结合的基于系统模型的复合控制策略。相较于比例-积分-微分PID(proportional-integral-derivative)和比例-谐振PR(proportional-resonant)控制器,此控制策略能够充分利用系统模型的知识与信息,简化控制器的设计并提高系统的控制性能。基于系统的控制对象模型,参考干扰信号模型和FSF闭环系统模型为复合控制提供了1种无需反复试错、简单通用的设计方法。最后将控制策略应用于1台3 kVA的三相PWM逆变器,验证了复合控制策略的有效性。展开更多
Within the new model of integrated medical and elderly care services,elderly-related data manifest a composite rights structure that integrates both public and private law dimensions.The granular and multi-dimensional...Within the new model of integrated medical and elderly care services,elderly-related data manifest a composite rights structure that integrates both public and private law dimensions.The granular and multi-dimensional nature and heightened sensitivity of such data,combined with the inherent vulnerability and dependency of elderly-related data subjects,render the regulatory landscape particularly complex.Existing mechanisms for data circulation reveal deficiencies,including fragmented legal norms,indeterminate allocation of data ownership,and supervisory inadequacy.This paper conducts a doctrinal inquiry into the legal relationships among multiple stakeholders across three principal dimensions:data service authorisation,data transmission and operation,and data supervision and safeguard.It proposes a regulatory framework based on a dual-track mechanism-combining top-down harmonisation of existing legal provisions with bottom-up implementation of data trusts-supported by a comprehensive oversight architecture involving government agencies,public interest organisations,and industry associations.This framework is intended to ensure the effective protection of the rights and interests of digitally vulnerable elderly individuals.展开更多
The multi-frequency and multi-dimensional adapted Runge-Kutta^NystrSm （ARKN） integrators, and multi-frequency and multi-dimensional extended Runge-Kutta-NystrSm （ERKN） integrators have been developed to efficientl...The multi-frequency and multi-dimensional adapted Runge-Kutta^NystrSm （ARKN） integrators, and multi-frequency and multi-dimensional extended Runge-Kutta-NystrSm （ERKN） integrators have been developed to efficiently solve multi-frequency oscillatory Hamiltonian systems. The aim of this paper is to analyze and derive high-order sym- plectic and symmetric composition methods based on the ARKN integrators and ERKN integrators. We first consider the symplecticity conditions for the multi-frequency and multi-dimensional ARKN integrators. We then analyze the symplecticity of the adjoint in- tegrators of the multi-frequency and multi^dimensional symplectic ARKN integrators and ERKN integrators, respectively. On the basis of the theoretical analysis and by using the idea of composition methods, we derive and propose four new high-order symplectic and symmetric methods for the multi-frequency oscillatory Hamiltonian systems. The numer- ical results accompanied in this paper quantitatively show the advantage and efficiency of the proposed high-order symplectic and symmetric methods.展开更多
基金Sponsored by the Quality Engineering Project of Education Department of Anhui Province(2022jyxm671)Research Team Project of Anhui Xinhua University(kytd202202)+1 种基金Key Project of Scientific Research(Natural Science)of Higher Education Institutions in Anhui Province(2022AH051861)Teaching Reform Research and Practice Quality Engineering Project of Anhui Xinhua University(2024jy035).
文摘During the critical transformation period of landscape architecture major after the adjustment of disciplinary structure and the changes in market demand,private colleges and universities,as important places for cultivating local talents,have pain points such as uneven quality of teachers and students and weak innovation and practice.The practice system with“multi-dimensional Integration”integrates four dimensions:interdisciplinary integration,spatial and temporal intersection,historical inheritance,and behavioral activity,deepens the disciplinary connotation,and integrates the three elements of nature,humanity,and technology,aiming to provide a new path for private colleges and universities to cultivate application-oriented and compound talents with innovative capabilities.In terms of optimizing talent cultivation and adapting to industry changes,this system provides thinking and reference for landscape architecture major,helping the major reshape its core competitiveness and promoting educational innovation and industry development.
文摘Particulate-reinforced metal matrix composites(PRMMCs)are difficult to machine due to the inclusion of hard,brittle reinforcing particles.Existing experimental investigations rarely reveal the complex material removal mechanisms(MRMs)involved in the machining of PRMMCs.This paper develops a three-dimensional(3D)microstructure-based model for investigating the MRM and surface integrity of machined PRMMCs.To accurately mimic the actual microstructure of a PRMMC,polyhedrons were randomly distributed inside the matrix to represent irregular SiC particles.Particle fracture and matrix deformation and failure were taken into account.For the model’s capability comparison,a two-dimensional(2D)analysis was also conducted.Relevant cutting experiments showed that the established 3D model accurately predicted the material removal,chip morphology,machined surface finish,and cutting forces.It was found that the matrix-particle-tool interactions led to particle fractures,mainly in the primary shear and secondary deformation zones along the cutting path and beneath the machined surface.Particle fracture and dilodegment greatly influences the quality of a machined surface.It was also found that although a 2D model can reflect certain material removal features,its ability to predict microstructural variation is limited.
文摘Given a set of requirements structured as design problems, we can apply design patterns to solve each problem individually. Much of the published literature on design patterns addresses this problem—pattern association;however, there is no systematic and practical way that shows how to integrate those individual solutions together. We propose a compositional model based on design patterns by abstracting their behavioral model using role modeling constructs. This approach describes how to transform a design pattern into a role model that can be used to assemble a software application. The role model captures the behavioral relationship between participant components in the design pattern. Our approach offers a complete practical design and implementation strategies, adapted from DCI (Data, Context, and Interaction) architecture. We demonstrate our technique by presenting a simple case study complete with design and implementation code. We also present a simple to follow process that provides guidelines of what to do and how to do it.
基金funded by the Science Committee of the Ministry of Science and Higher Education of the Republic of Kazakhstan(Grant No.AP19680589).
文摘This research extends ongoing efforts to develop methods for reinforcing damaged main gas pipelines to prevent catastrophic failure.This study establishes the use of scaled-down experimental models for assessing the dynamic strength of damaged pipeline sections reinforced with wire wrapping or composite sleeves.A generalized dynamic model is introduced for numerical simulation to evaluate the effectiveness of reinforcement techniques.The model incorporates the elastoplastic behavior of pipe and wire materials,the influence of temperature on mechanical properties,the contact interaction between the pipe and the reinforcement components(including pretensioning),and local material failure under transient internal pressure.Based on these parameters,a finite element model was developed using ANSYS 19.2 to enable parametric studies.The accuracy of the proposed model was verified by comparing the simulation results with the experimental findings.Pipeline section samples containing non-penetrating longitudinal crackswere subjected to comparative analyses and transient pressure until critical failure.The unreinforced and steel wire-wrapped sections were investigated.The results confirm the feasibility of applying the computational model to study the dynamic strength of reinforced damaged pipe sections.Furthermore,pipelines with longitudinal cracks reinforced using circular composite overlays with orthotropic mechanical properties were examined,and recommendations are provided for selecting the geometric parameters of such overlays.
文摘近年来,复合材料层合板结构被广泛地应用于航空航天、军工、建筑工程等领域。但是,由于其几何尺寸的不准确性、材料参数的分散性、载荷环境的波动性等不确定性因素的影响,可能会对复合材料层合板结构的可靠性和安全性,以及系统的输出响应产生重大影响。由于复合材料层合板的层间黏结不良、外部应力集中等因素,当复合材料层合板结构的能量释放速率达到层间断裂韧性时,就会发生分层。因此对复合材料层合板结构的分层可靠性进行分析具有重要的意义。目前,对于复合材料层合板结构的可靠性分析主要是采用一阶可靠性方法(first order reliability method,FORM)、二阶可靠性方法(second order reliability method,SORM)和重要性抽样方法(importance sampling,IS)等传统可靠性分析方法,并将其和蒙特卡罗模拟(Monte Carlo simulation,MCS)对比。但是,当复合材料结构不确定性维度高且复杂时,这些方法不仅计算效率太低,而且不能保证其计算精度。相比于传统的可靠性分析方法,可以利用基于自适应Kriging模型集成策略和主动学习函数结合蒙特卡罗模拟(adaptive Kriging-based Monte Carlo simulation,AK-MCS)的方法,对复合材料层合板结构进行可靠性分析。而直接概率积分方法(direct probability integral method,DPIM)具有更高的计算效率和精度,特别是对于高维度和复杂的可靠性分析问题。所以,本文采用AK-MCS方法和DPIM对模式Ⅰ、模式Ⅱ和混合Ⅰ/Ⅱ模式下的复合材料层合板结构分层的可靠度进行了研究。结果表明:DPIM和AK-MCS与传统可靠性分析方法相比具有更高的计算精度和计算效率,但是DPIM以其高效的计算效率脱颖而出,尽管其精度略低于AK-MCS,但在处理随机变量更多、非线性程度更高的混合Ⅰ/Ⅱ模式下的层合板结构分层的可靠性时展现出明显优势。综合考虑精度与时效性的平衡,DPIM能够准确地评估复合材料结构的可靠度,保障其在航天航空装备等领域的安全运行。
文摘对于电力电子变换器、电机等控制对象模型明确的系统,提出1个由全状态反馈FSF(full state feedback)控制器和广义积分GI(generalized integrator)相结合的基于系统模型的复合控制策略。相较于比例-积分-微分PID(proportional-integral-derivative)和比例-谐振PR(proportional-resonant)控制器,此控制策略能够充分利用系统模型的知识与信息,简化控制器的设计并提高系统的控制性能。基于系统的控制对象模型,参考干扰信号模型和FSF闭环系统模型为复合控制提供了1种无需反复试错、简单通用的设计方法。最后将控制策略应用于1台3 kVA的三相PWM逆变器,验证了复合控制策略的有效性。
文摘Within the new model of integrated medical and elderly care services,elderly-related data manifest a composite rights structure that integrates both public and private law dimensions.The granular and multi-dimensional nature and heightened sensitivity of such data,combined with the inherent vulnerability and dependency of elderly-related data subjects,render the regulatory landscape particularly complex.Existing mechanisms for data circulation reveal deficiencies,including fragmented legal norms,indeterminate allocation of data ownership,and supervisory inadequacy.This paper conducts a doctrinal inquiry into the legal relationships among multiple stakeholders across three principal dimensions:data service authorisation,data transmission and operation,and data supervision and safeguard.It proposes a regulatory framework based on a dual-track mechanism-combining top-down harmonisation of existing legal provisions with bottom-up implementation of data trusts-supported by a comprehensive oversight architecture involving government agencies,public interest organisations,and industry associations.This framework is intended to ensure the effective protection of the rights and interests of digitally vulnerable elderly individuals.
文摘The multi-frequency and multi-dimensional adapted Runge-Kutta^NystrSm （ARKN） integrators, and multi-frequency and multi-dimensional extended Runge-Kutta-NystrSm （ERKN） integrators have been developed to efficiently solve multi-frequency oscillatory Hamiltonian systems. The aim of this paper is to analyze and derive high-order sym- plectic and symmetric composition methods based on the ARKN integrators and ERKN integrators. We first consider the symplecticity conditions for the multi-frequency and multi-dimensional ARKN integrators. We then analyze the symplecticity of the adjoint in- tegrators of the multi-frequency and multi^dimensional symplectic ARKN integrators and ERKN integrators, respectively. On the basis of the theoretical analysis and by using the idea of composition methods, we derive and propose four new high-order symplectic and symmetric methods for the multi-frequency oscillatory Hamiltonian systems. The numer- ical results accompanied in this paper quantitatively show the advantage and efficiency of the proposed high-order symplectic and symmetric methods.
