With the rapid development of science and technology and the increasing popularity of the Internet,the number of network users is gradually expanding,and the behavior of network users is becoming more and more complex...With the rapid development of science and technology and the increasing popularity of the Internet,the number of network users is gradually expanding,and the behavior of network users is becoming more and more complex.Users’actual demand for resources on the network application platform is closely related to their historical behavior records.Therefore,it is very important to analyze the user behavior path conversion rate.Therefore,this paper analyses and studies user behavior path based on sales data.Through analyzing the user quality of the website as well as the user’s repurchase rate,repurchase rate and retention rate in the website,we can get some user habits and use the data to guide the website optimization.展开更多
Coarse aggregates are the major infrastructure materials of concrete-faced rock-fill dams and are consolidated to bear upper and lateral loads. With the increase of dam height, high confining pressure and complex stre...Coarse aggregates are the major infrastructure materials of concrete-faced rock-fill dams and are consolidated to bear upper and lateral loads. With the increase of dam height, high confining pressure and complex stress states complicate the shear behavfor of coarse aggregates, and thus impede the high dam's proper construction, operation and maintenance. An experimental program was conducted to study the shear behavior of dam coarse aggregates using a large-scale triaxial shear apparatus. Through triaxial shear tests, the strain-stress behaviors of aggregates were observed under constant confining pressures: 300 kPa, 600 kPa 900 kPa and 1200 kPa. Shear strengths and aggregate breakage characteristics associated with high pressure shear processes are discussed. Stress path tests were conducted to observe and analyze coarse aggregate response under complex stress states. In triaxial shear tests, it was found that peak deviator stresses increase along with confining pressures, whereas the peak principal stress ratios decrease as confining pressures increase With increasing confining pressures, the dilation decreases and the contraction eventually prevails. Initial strength parameters (Poisson's ratio and tangent modulus) show a nonlinear relationship with confining pressures when the pressures are relatively low. Shear strength parameters decrease with increasing confining pressures. The failure envelope lines are convex curves, with clear curvature under low confining pressures. Under moderate confining pressures, dilation is offset by particle breakage. Under high confining pressures, dilation disappears.展开更多
The magnetomechanical behavior of single-crystal Galfenol alloy was found to be strongly dependent on the loading paths. An energy-based anisotropic domain rotation model, assuming that the interaction between domains...The magnetomechanical behavior of single-crystal Galfenol alloy was found to be strongly dependent on the loading paths. An energy-based anisotropic domain rotation model, assuming that the interaction between domains can be ignored and the probability of the magnetic moment pointing along a particular direction is related to the free energy along this direction, is used to simulate the magnetostriction versus magnetic field and stress curve and to track the magnetic domain motion trail. The main reason for loading path dependent effect is the rotation/flipping of the magnetic domains under different loading paths. The effect of loading and unloading paths on 90° magnetic domain motion was studied by choosing different loading and unloading state and paths. The results show that prior loading magnetic field can make the 90° magnetic domains flip to the directions of 45°domains because the magnetic field is the driving force to make the domains rotate, and the final loading state and the loading path both have great influence on the motion of 90° magnetic domains.展开更多
The problem of the unmanned surface vessel (USV) path planning in static and dynamic obstacle environments is addressed in this paper. Multi-behavior fusion based potential field method is proposed, which contains thr...The problem of the unmanned surface vessel (USV) path planning in static and dynamic obstacle environments is addressed in this paper. Multi-behavior fusion based potential field method is proposed, which contains three behaviors: goal-seeking, boundary-memory following and dynamic-obstacle avoidance. Then, different activation conditions are designed to determine the current behavior. Meanwhile, information on the positions, velocities and the equation of motion for obstacles are detected and calculated by sensor data. Besides, memory information is introduced into the boundary following behavior to enhance cognition capability for the obstacles, and avoid local minima problem caused by the potential field method. Finally, the results of theoretical analysis and simulation show that the collision-free path can be generated for USV within different obstacle environments, and further validated the performance and effectiveness of the presented strategy.展开更多
We propose a scaling theory for single gate Al In Sb/In Sb high electron mobility transistors(HEMTs) by solving the two-dimensional(2D) Poisson equation. In our model, the effective conductive path effect(ECPE) ...We propose a scaling theory for single gate Al In Sb/In Sb high electron mobility transistors(HEMTs) by solving the two-dimensional(2D) Poisson equation. In our model, the effective conductive path effect(ECPE) is taken into account to overcome the problems arising from the device scaling. The potential in the effective conducting path is developed and a simple scaling equation is derived. This equation is solved to obtain the minimum channel potential Φdeff,minand the new scaling factor α to model the subthreshold behavior of the HEMTs. The developed model minimizes the leakage current and improves the subthreshold swing degradation of the HEMTs. The results of the analytical model are verified by numerical simulation with a Sentaurus TCAD device simulator.展开更多
Dynamic-Relaxation Method (DRM) is applied to studying the influence of compression-bending coupling on nonlinear behavior of cylindrically slightly curved panels of unsymmetric laminated composite materials subjected...Dynamic-Relaxation Method (DRM) is applied to studying the influence of compression-bending coupling on nonlinear behavior of cylindrically slightly curved panels of unsymmetric laminated composite materials subjected to uniform uniaxial Compression during loading and unloading. Numerical results are given for cross-ply plates and panels under S4S4 and S4S2 boundary conditions. The results show that the effects of absolute value and the sign of the coupling coefficient on the stability behavior of the panles are significant.展开更多
目的探讨儿童行为特点及其家庭管理方式对儿童哮喘控制水平影响路径。方法采用便利抽样法选取82例哮喘患儿,应用一般资料问卷、适应行为量表(AAMR)、家庭管理测量量表(FaMM)及儿童哮喘控制测试表(Childhood asthma control test,C-ACT)...目的探讨儿童行为特点及其家庭管理方式对儿童哮喘控制水平影响路径。方法采用便利抽样法选取82例哮喘患儿,应用一般资料问卷、适应行为量表(AAMR)、家庭管理测量量表(FaMM)及儿童哮喘控制测试表(Childhood asthma control test,C-ACT)进行问卷调查,分析其影响路径。结果患儿AAMR适应行为量表得分(84.87±9.16)分,FaMM量表得分(188.77±19.01)分,C-ACT得分(15.20±4.66)分。Pearson相关分析结果显示,适应性行为分别与家庭管理、哮喘控制呈正相关关系(r=0.580、0.219,P<0.05),家庭管理与哮喘控制呈正相关关系(r=0.401,P<0.05)。结构方程模型结果表明,家庭管理在哮喘患儿适应性行为和哮喘控制有部分中介调节作用,效应占比为45.95%。结论儿童行为特点能够通过家庭管理方式对患儿哮喘控制水平产生影响,临床护理人员应重视对患儿家属的健康教育管理,提升家属对疾病的认知度及家庭管理能力,以改善患儿的行为方式,达到有效控制患儿疾病的目的。展开更多
工作场所安全行为研究在过去50年已形成丰富的知识体系,分析该领域知识流动与演化过程,展望未来研究方向,对提升我国安全生产治理现代化水平具有重要指导意义。以Web of Science数据库收录的1086篇SCI和SSCI期刊文献为样本,综合使用Cite...工作场所安全行为研究在过去50年已形成丰富的知识体系,分析该领域知识流动与演化过程,展望未来研究方向,对提升我国安全生产治理现代化水平具有重要指导意义。以Web of Science数据库收录的1086篇SCI和SSCI期刊文献为样本,综合使用CiteSpace、Histcite以及Pajek等文献计量和大规模引文网络分析工具,明确1973—2021年间工作场所安全行为研究概貌特征,挖掘该领域研究热点及其关联性,以揭示知识扩散路径。研究发现:工作场所安全行为国际研究在2003,2013年经历2次快速发展,且形成以美国、中国和澳大利亚为核心的跨国合作研究网络;工作场所安全行为国际研究经历初始萌芽、初步发展和快速发展3个主要阶段,尽管安全氛围和安全领导力一直是该领域研究热点,但不同阶段的研究热点经历了从事故伤害到安全行为、从安全文化到安全氛围、从安全领导力到安全心理契约的多维转变,体现了时代特征和现实需求。最后,从研究场景、视角、范畴、内容、对象和方法等6个方面,提出工作场所安全行为领域未来研究方向。展开更多
基金funded by the Open Foundation for the University Innovation Platform in the Hunan Province,grant number 18K103Open project,Grant Number 20181901CRP03,20181901CRP04,20181901CRP05+1 种基金Hunan Provincial Education Science 13th Five-Year Plan(Grant No.XJK016BXX001),Social Science Foundation of Hunan Province(Grant No.17YBA049)supported by the project 18K103。
文摘With the rapid development of science and technology and the increasing popularity of the Internet,the number of network users is gradually expanding,and the behavior of network users is becoming more and more complex.Users’actual demand for resources on the network application platform is closely related to their historical behavior records.Therefore,it is very important to analyze the user behavior path conversion rate.Therefore,this paper analyses and studies user behavior path based on sales data.Through analyzing the user quality of the website as well as the user’s repurchase rate,repurchase rate and retention rate in the website,we can get some user habits and use the data to guide the website optimization.
基金supported by the National Natural Science Foundation of China (Grant No. 50639050)
文摘Coarse aggregates are the major infrastructure materials of concrete-faced rock-fill dams and are consolidated to bear upper and lateral loads. With the increase of dam height, high confining pressure and complex stress states complicate the shear behavfor of coarse aggregates, and thus impede the high dam's proper construction, operation and maintenance. An experimental program was conducted to study the shear behavior of dam coarse aggregates using a large-scale triaxial shear apparatus. Through triaxial shear tests, the strain-stress behaviors of aggregates were observed under constant confining pressures: 300 kPa, 600 kPa 900 kPa and 1200 kPa. Shear strengths and aggregate breakage characteristics associated with high pressure shear processes are discussed. Stress path tests were conducted to observe and analyze coarse aggregate response under complex stress states. In triaxial shear tests, it was found that peak deviator stresses increase along with confining pressures, whereas the peak principal stress ratios decrease as confining pressures increase With increasing confining pressures, the dilation decreases and the contraction eventually prevails. Initial strength parameters (Poisson's ratio and tangent modulus) show a nonlinear relationship with confining pressures when the pressures are relatively low. Shear strength parameters decrease with increasing confining pressures. The failure envelope lines are convex curves, with clear curvature under low confining pressures. Under moderate confining pressures, dilation is offset by particle breakage. Under high confining pressures, dilation disappears.
基金Project supported by the General Program of National Natural Science Foundation of China(Grant No.51371028)
文摘The magnetomechanical behavior of single-crystal Galfenol alloy was found to be strongly dependent on the loading paths. An energy-based anisotropic domain rotation model, assuming that the interaction between domains can be ignored and the probability of the magnetic moment pointing along a particular direction is related to the free energy along this direction, is used to simulate the magnetostriction versus magnetic field and stress curve and to track the magnetic domain motion trail. The main reason for loading path dependent effect is the rotation/flipping of the magnetic domains under different loading paths. The effect of loading and unloading paths on 90° magnetic domain motion was studied by choosing different loading and unloading state and paths. The results show that prior loading magnetic field can make the 90° magnetic domains flip to the directions of 45°domains because the magnetic field is the driving force to make the domains rotate, and the final loading state and the loading path both have great influence on the motion of 90° magnetic domains.
基金financially supported by the National Natural Science Foundation of China(Grant No.51879049)DK-I Dynamic Positioning System Console Project
文摘The problem of the unmanned surface vessel (USV) path planning in static and dynamic obstacle environments is addressed in this paper. Multi-behavior fusion based potential field method is proposed, which contains three behaviors: goal-seeking, boundary-memory following and dynamic-obstacle avoidance. Then, different activation conditions are designed to determine the current behavior. Meanwhile, information on the positions, velocities and the equation of motion for obstacles are detected and calculated by sensor data. Besides, memory information is introduced into the boundary following behavior to enhance cognition capability for the obstacles, and avoid local minima problem caused by the potential field method. Finally, the results of theoretical analysis and simulation show that the collision-free path can be generated for USV within different obstacle environments, and further validated the performance and effectiveness of the presented strategy.
基金Project supported by the Council of Scientific&Industrial Research(CSIR),Government of India under the SRF Scheme(Sanction Letter No:08/237(0005)/2012-EMR-I)
文摘We propose a scaling theory for single gate Al In Sb/In Sb high electron mobility transistors(HEMTs) by solving the two-dimensional(2D) Poisson equation. In our model, the effective conductive path effect(ECPE) is taken into account to overcome the problems arising from the device scaling. The potential in the effective conducting path is developed and a simple scaling equation is derived. This equation is solved to obtain the minimum channel potential Φdeff,minand the new scaling factor α to model the subthreshold behavior of the HEMTs. The developed model minimizes the leakage current and improves the subthreshold swing degradation of the HEMTs. The results of the analytical model are verified by numerical simulation with a Sentaurus TCAD device simulator.
文摘Dynamic-Relaxation Method (DRM) is applied to studying the influence of compression-bending coupling on nonlinear behavior of cylindrically slightly curved panels of unsymmetric laminated composite materials subjected to uniform uniaxial Compression during loading and unloading. Numerical results are given for cross-ply plates and panels under S4S4 and S4S2 boundary conditions. The results show that the effects of absolute value and the sign of the coupling coefficient on the stability behavior of the panles are significant.
文摘目的探讨儿童行为特点及其家庭管理方式对儿童哮喘控制水平影响路径。方法采用便利抽样法选取82例哮喘患儿,应用一般资料问卷、适应行为量表(AAMR)、家庭管理测量量表(FaMM)及儿童哮喘控制测试表(Childhood asthma control test,C-ACT)进行问卷调查,分析其影响路径。结果患儿AAMR适应行为量表得分(84.87±9.16)分,FaMM量表得分(188.77±19.01)分,C-ACT得分(15.20±4.66)分。Pearson相关分析结果显示,适应性行为分别与家庭管理、哮喘控制呈正相关关系(r=0.580、0.219,P<0.05),家庭管理与哮喘控制呈正相关关系(r=0.401,P<0.05)。结构方程模型结果表明,家庭管理在哮喘患儿适应性行为和哮喘控制有部分中介调节作用,效应占比为45.95%。结论儿童行为特点能够通过家庭管理方式对患儿哮喘控制水平产生影响,临床护理人员应重视对患儿家属的健康教育管理,提升家属对疾病的认知度及家庭管理能力,以改善患儿的行为方式,达到有效控制患儿疾病的目的。
文摘工作场所安全行为研究在过去50年已形成丰富的知识体系,分析该领域知识流动与演化过程,展望未来研究方向,对提升我国安全生产治理现代化水平具有重要指导意义。以Web of Science数据库收录的1086篇SCI和SSCI期刊文献为样本,综合使用CiteSpace、Histcite以及Pajek等文献计量和大规模引文网络分析工具,明确1973—2021年间工作场所安全行为研究概貌特征,挖掘该领域研究热点及其关联性,以揭示知识扩散路径。研究发现:工作场所安全行为国际研究在2003,2013年经历2次快速发展,且形成以美国、中国和澳大利亚为核心的跨国合作研究网络;工作场所安全行为国际研究经历初始萌芽、初步发展和快速发展3个主要阶段,尽管安全氛围和安全领导力一直是该领域研究热点,但不同阶段的研究热点经历了从事故伤害到安全行为、从安全文化到安全氛围、从安全领导力到安全心理契约的多维转变,体现了时代特征和现实需求。最后,从研究场景、视角、范畴、内容、对象和方法等6个方面,提出工作场所安全行为领域未来研究方向。