资源类型

期刊论文 297

年份

2023 7

2022 9

2021 19

2020 14

2019 19

2018 18

2017 12

2016 11

2015 15

2014 18

2013 13

2012 18

2011 13

2010 11

2009 19

2008 18

2007 24

2006 6

2005 11

2004 3

展开 ︾

关键词

应力 3

应力状态 3

残余应力 3

DX桩 2

业主 2

委托代理 2

工程监理 2

应力波 2

强度理论 2

CP）；符号间干扰（inter symbol interference， ISI）；载波间干扰（inter carrier interference 1

D1 turnover / photoinhibition / photoprotection / photosynthesis / tomato / xanthophyll cycle 1

DPP）；分布式功率转换器；开关电容转换器 1

H2S应力腐蚀 1

ICI）；最大似然估计（maximum likelihood estimation 1

LED灯具；加速老化测试；中位寿命；滑动平均误差 1

MLE） 1

MPPT）；差分功率处理（Differential power processing 1

OFDM）；快速傅立叶变换（Fast Fourier transform， FFT）；循环前缀（cyclic prefix 1

SWOT分析 1

展开 ︾

检索范围：

排序： 展示方式：

Global sensitivity analysis of certain and uncertain factors for a circular tunnel under seismic action

Nazim Abdul NARIMAN, Raja Rizwan HUSSAIN, Ilham Ibrahim MOHAMMAD, Peyman KARAMPOUR

《结构与土木工程前沿（英文）》 2019年 第13卷 第6期   页码 1289-1300 doi: 10.1007/s11709-019-0548-0

摘要： There are many certain and uncertain design factors which have unrevealed rational effects on the generation of tensile damage and the stability of the circular tunnels during seismic actions. In this research paper, we have dedicated three certain and four uncertain design factors to quantify their rational effects using numerical simulations and the Sobol’s sensitivity indices. Main effects and interaction effects between the design factors have been determined supporting on variance-based global sensitivity analysis. The results detected that the concrete modulus of elasticity for the tunnel lining has the greatest effect on the tensile damage generation in the tunnel lining during the seismic action. In the other direction, the interactions between the concrete density and both of concrete modulus of elasticity and tunnel diameter have appreciable effects on the tensile damage. Furthermore, the tunnel diameter has the deciding effect on the stability of the tunnel structure. While the interaction between the tunnel diameter and concrete density has appreciable effect on the stability process. It is worthy to mention that Sobol’s sensitivity indices manifested strong efficiency in detecting the roles of each design factor in cooperation with the numerical simulations explaining the responses of the circular tunnel during seismic actions.

关键词： shear waves     Sobol’s sensitivity indices     maximum principal stress     maximum overall displacement     tensile damage    

HTML PDF 收藏

Application of coupled XFEM-BCQO in the structural optimization of a circular tunnel lining subjected to a ground motion

Nazim Abdul NARIMAN, Ayad Mohammad RAMADAN, Ilham Ibrahim MOHAMMAD

《结构与土木工程前沿（英文）》 2019年 第13卷 第6期   页码 1495-1509 doi: 10.1007/s11709-019-0574-y

摘要： A new structural optimization method of coupled extended finite element method and bound constrained quadratic optimization method (XFEM-BCQO) is adopted to quantify the optimum values of four design parameters for a circular tunnel lining when it is subjected to earthquakes. The parameters are: tunnel lining thickness, tunnel diameter, tunnel lining concrete modulus of elasticity and tunnel lining concrete density. Monte-Carlo sampling method is dedicated to construct the meta models so that to be used for the BCQO method using matlab codes. Numerical simulations of the tensile damage in the tunnel lining due to a real earthquake in the literature are created for three design cases. XFEM approach is used to show the cracks for the mentioned design cases. The results of the BCQO method for the maximum design case for the tunnel tensile damage was matching the results obtained from XFEM approach to a fair extent. The new coupled approach manifested a significant capability to predict the cracks and spalling of the tunnel lining concrete under the effects of dynamic earthquakes.

关键词： ovaling deformation     monte carlo sampling     XFEM-BCQO     maximum principal stress    

HTML PDF 收藏

Behavior of dam concrete under biaxial compression-tension and triaxial compression-compression-tension stresses

WANG Huailiang, SONG Yupu

《结构与土木工程前沿（英文）》 2008年 第2卷 第4期   页码 323-328 doi: 10.1007/s11709-008-0043-5

摘要： In order to meet the requirement for nonlinear analysis and design of mass concrete structures, the deformation behavior and strength of three-graded concrete specimens 250 mm × 250 mm × 400 mm with a maximum aggregate size of 80 mm and the corresponding wet-screened concrete specimens 150 mm × 150 mm × 300 mm with a maximum aggregate size of 40 mm were studied experimentally. Specimens subjected to biaxial compression-tension (C-T) and triaxial compression-compression-tension (C-C-T) stress states. Test data indicate that both the deformation and strength of the mass concrete specimens are lower than those of the corresponding wet-screened concrete small specimens, but the initial tangent modulus of the stress-strain curve of the former is greater than that of the latter. Test results show that the wet-screened effect and size effect of the specimens under complex stress states are obvious such that these should be considered in the design of mass concrete structures. In addition, respective failure criteria for mass concrete in principal stress space and octahedron stress space are proposed.

关键词： requirement     wet-screened concrete     compression-tension     maximum aggregate     principal    

HTML PDF 收藏

软夹芯夹层梁最大弯曲正应力的计算

郝景新,刘文金,吴新凤

《中国工程科学》 2014年 第16卷 第4期   页码 92-95

摘要：

最大弯曲正应力是衡量夹层梁弯曲性能的重要参数之一，本文推导出了将软夹芯夹层梁等效成等 截面均质单层梁计算最大弯曲正应力的方法，并在此基础上进行三点弯曲试验的算例研究。结果表明：修正单层梁理论与层合梁理论计算的结果是一致的。当破坏载荷与夹层梁横截面的尺寸一定时，随着芯层与总厚度比的增加，修正单层梁理论计算的最大正应力值逐渐增加，而单层梁理论计算的结果为一恒定值。最大弯曲正应力修正公式的建立为夹层梁的工程应用提供理论基础。

关键词： 夹层梁     弯曲正应力     单层梁理论     弯曲特性    

HTML PDF 收藏

Shaking-moment balancing of mechanisms with principal vectors and momentum

V. van der WIJK

《机械工程前沿（英文）》 2013年 第8卷 第1期   页码 10-16 doi: 10.1007/s11465-013-0359-2

摘要：

The design of shaking-moment-balanced linkages still is challenging. Considering moment balance in the very beginning of the design process of mechanisms is important for finding applicable solutions. For this purpose, the method of principal vectors is investigated, showing a compact notation of the angular momentum with respect to the center of mass. The moment balance conditions are derived for three elements in series from which balance solutions are synthesized and illustrated. From the application for moment balancing of a 4R four-bar linkage it is shown that the moment balancing of closed kinematic chains remains challenging.

关键词： shaking-moment balancing     principal vector linkage     angular momentum    

HTML PDF 收藏

Determination of the principal factors of river water quality through cluster analysis method and its

Liang GUO, Ying ZHAO, Peng WANG

《环境科学与工程前沿（英文）》 2012年 第6卷 第2期   页码 238-245 doi: 10.1007/s11783-011-0382-7

摘要： In this paper, an artificial neural network model was built to predict the Chemical Oxygen Demand (COD ) measured by permanganate index in Songhua River. To enhance the prediction accuracy, principal factors were determined through the analysis of the weight relation between influencing factors and forecasting object using cluster analysis method, which optimized the topological structure of the prediction model input items of the artificial neural network. It was shown that application of the principal factors in water quality prediction model can improve its forecasting skill significantly through the comparison between results of prediction by artificial neural network and the measurements of the COD . This methodology is also applicable to various water quality prediction targets of other water bodies and it is valuable for theoretical study and practical application.

关键词： water quality forecast     principal factor     cluster analysis method     artificial neural network    

HTML PDF 收藏

Non-negativematrix factorization based unmixing for principal component transformed hyperspectral data

Xiu-rui GENG,Lu-yan JI,Kang SUN

《信息与电子工程前沿（英文）》 2016年 第17卷 第5期   页码 403-412 doi: 10.1631/FITEE.1600028

摘要： Non-negative matrix factorization (NMF) has been widely used in mixture analysis for hyperspectral remote sensing. When used for spectral unmixing analysis, however, it has two main shortcomings: (1) since the dimensionality of hyperspectral data is usually very large, NMF tends to suffer from large computational complexity for the popular multiplicative iteration rule; (2) NMF is sensitive to noise (outliers), and thus the corrupted data will make the results of NMF meaningless. Although principal component analysis (PCA) can be used to mitigate these two problems, the transformed data will contain negative numbers, hindering the direct use of the multiplicative iteration rule of NMF. In this paper, we analyze the impact of PCA on NMF, and find that multiplicative NMF can also be applicable to data after principal component transformation. Based on this conclusion, we present a method to perform NMF in the principal component space, named ‘principal component NMF’ (PCNMF). Experimental results show that PCNMF is both accurate and time-saving.

关键词： Non-negative matrix factorization (NMF)     Principal component analysis (PCA)     Endmember     Hyperspectral    

HTML PDF 收藏

Principle of maximum entropy for reliability analysis in the design of machine components

Yimin ZHANG

《机械工程前沿（英文）》 2019年 第14卷 第1期   页码 21-32 doi: 10.1007/s11465-018-0512-z

摘要： We studied the reliability of machine components with parameters that follow an arbitrary statistical distribution using the principle of maximum entropy (PME). We used PME to select the statistical distribution that best fits the available information. We also established a probability density function (PDF) and a failure probability model for the parameters of mechanical components using the concept of entropy and the PME. We obtained the first four moments of the state function for reliability analysis and design. Furthermore, we attained an estimate of the PDF with the fewest human bias factors using the PME. This function was used to calculate the reliability of the machine components, including a connecting rod, a vehicle half-shaft, a front axle, a rear axle housing, and a leaf spring, which have parameters that typically follow a non-normal distribution. Simulations were conducted for comparison. This study provides a design methodology for the reliability of mechanical components for practical engineering projects.

关键词： machine components     reliability     arbitrary distribution parameter     principle of maximum entropy    

HTML PDF 收藏

optimization of cutting parameters in high-speed milling based on grey relational analysis coupled with principal

Tao FU, Jibin ZHAO, Weijun LIU

《机械工程前沿（英文）》 2012年 第7卷 第4期   页码 445-452 doi: 10.1007/s11465-012-0338-z

摘要：

This paper investigates optimization problem of the cutting parameters in high-speed milling on NAK80 mold steel. An experiment based on the technology of Taguchi is performed. The objective is to establish a correlation among spindle speed, feed per tooth and depth of cut to the three directions of cutting force in the milling process. In this study, the optimum cutting parameters are obtained by the grey relational analysis. Moreover, the principal component analysis is applied to evaluate the weights so that their relative significance can be described properly and objectively. The results of experiments show that grey relational analysis coupled with principal component analysis can effectively acquire the optimal combination of cutting parameters and the proposed approach can be a useful tool to reduce the cutting force.

关键词： high-speed milling     grey relational analysis     principal component analysis     parameters optimization    

HTML PDF 收藏

Fractional order extremum seeking approach for maximum power point tracking of photovoltaic panels

Ammar NEÇAIBIA,Samir LADACI,Abdelfatah CHAREF,Jean Jacques LOISEAU

《能源前沿（英文）》 2015年 第9卷 第1期   页码 43-53 doi: 10.1007/s11708-014-0343-5

摘要： Due to the high interest in renewable energy and diversity of research regarding photovoltaic (PV) array, a great research effort is focusing nowadays on solar power generation and its performance improvement under various weather conditions. In this paper, an integrated framework was proposed, which achieved both maximum power point tracking (MPPT) and minimum ripple signals. The proposed control scheme was based on extremum-seeking (ES) combined with fractional order systems (FOS). This auto-tuning strategy was developed to maximize the PV panel output power through the regulation of the voltage input to the DC/DC converter in order to lead the PV system steady-state to a stable oscillation behavior around the maximum power point (MPP). It is shown that fractional order operators can improve the plant dynamics with respect to time response and disturbance rejection. The effectiveness of the proposed controller scheme is illustrated with simulations using measured solar radiation data.

关键词： extremum seeking (ES)     fractional order control (FOC)     fractional calculus     photovoltaic (PV) panel     maximum power point tracking (MPPT)    

HTML PDF 收藏

The combined effects of biomass and temperature on maximum specific ammonia oxidation rate in domestic

《环境科学与工程前沿（英文）》 2021年 第15卷 第6期 doi: 10.1007/s11783-021-1411-9

摘要：

• Actual SAORs was determined using MLVSS and temperature.

关键词： Specific ammonia oxidation rate     Sequencing batch reactor     Biomass     Temperature coefficient     Model simulation    

HTML PDF 收藏

Topology optimization of transient problem with maximum dynamic response constraint using SOAR scheme

《机械工程前沿（英文）》 2021年 第16卷 第3期   页码 593-606 doi: 10.1007/s11465-021-0636-4

摘要： This paper proposes a novel method for the continuum topology optimization of transient vibration problem with maximum dynamic response constraint. An aggregated index in the form of an integral function is presented to cope with the maximum response constraint in the time domain. The density filter solid isotropic material with penalization method combined with threshold projection is developed. The sensitivities of the proposed index with respect to design variables are conducted. To reduce computational cost, the second-order Arnoldi reduction (SOAR) scheme is employed in transient analysis. Influences of aggregate parameter, duration of loading period, interval time, and number of basis vectors in the SOAR scheme on the final designs are discussed through typical examples while unambiguous configuration can be achieved. Through comparison with the corresponding static response from the final designs, the optimized results clearly demonstrate that the transient effects cannot be ignored in structural topology optimization.

关键词： topology optimization     solid isotropic material with penalization     transient response     aggregation function     second-order Arnoldi reduction    

HTML PDF 收藏

工程监理委托代理关系中激励约束与参与约束的研究

秦旋

《中国工程科学》 2007年 第9卷 第4期   页码 45-49

摘要：

基于委托－代理理论对工程监理委托－代理关系中的激励约束与参与约束进行若干拓展研究，与参 与约束（IR）相比，激励相容约束（IC）更为重要，一个机制不满足激励约束，那将是一个无效机制。业主想要 提高工程监理制度的运作效率，就必须通过相应的激励措施诱使工程师努力工作，使“道德风险”得以抑制， 为我国工程监理制度的健康发展提供了有益的启示。

关键词： 工程监理     业主     工程师     委托代理     激励相容约束     参与约束    

HTML PDF 收藏

Maximum entropy based finite element analysis of porous media

Emad NOROUZI, Hesam MOSLEMZADEH, Soheil MOHAMMADI

《结构与土木工程前沿（英文）》 2019年 第13卷 第2期   页码 364-379 doi: 10.1007/s11709-018-0470-x

摘要： The maximum entropy theory has been used in a wide variety of physical, mathematical and engineering applications in the past few years. However, its application in numerical methods, especially in developing new shape functions, has attracted much interest in recent years. These shape functions possess the potential for performing better than the conventional basis functions in problems with randomly generated coarse meshes. In this paper, the maximum entropy theory is adopted to spatially discretize the deformation variable of the governing coupled equations of porous media. This is in line with the well-known fact that higher-order shape functions can provide more stable solutions in porous problems. Some of the benchmark problems in deformable porous media are solved with the developed approach and the results are compared with available references.

关键词： maximum entropy FEM     fully coupled multi-phase system     porous media    

HTML PDF 收藏

一种基于主成分分析的企业并购目标遴选综合评价模型探讨

罗一新

《中国工程科学》 2009年 第11卷 第11期   页码 92-96

摘要：

在广泛调查研究的基础上，提出了并购目标企业的遴选综合评价指标体系，利用主成分法建立了综合评价模型，并结合实际案例进行了分析，结果证明了评价指标体系和遴选评价模型的可行性，并通过建模计算，对多个并购目标进行排序，为我国正处发展期的企业并购活动提供了一种可行的、便于辅助买方企业决策的并购目标遴选综合评价方法。

关键词： 主成分分析     企业并购     目标遴选     评价指标体系     评价模型    

HTML PDF 收藏

标题 作者 时间 类型 操作

Global sensitivity analysis of certain and uncertain factors for a circular tunnel under seismic action

Nazim Abdul NARIMAN, Raja Rizwan HUSSAIN, Ilham Ibrahim MOHAMMAD, Peyman KARAMPOUR

期刊论文

Application of coupled XFEM-BCQO in the structural optimization of a circular tunnel lining subjected to a ground motion

Nazim Abdul NARIMAN, Ayad Mohammad RAMADAN, Ilham Ibrahim MOHAMMAD

期刊论文

Behavior of dam concrete under biaxial compression-tension and triaxial compression-compression-tension stresses

WANG Huailiang, SONG Yupu

期刊论文

软夹芯夹层梁最大弯曲正应力的计算

郝景新,刘文金,吴新凤

期刊论文

Shaking-moment balancing of mechanisms with principal vectors and momentum

V. van der WIJK

期刊论文

Determination of the principal factors of river water quality through cluster analysis method and its

Liang GUO, Ying ZHAO, Peng WANG

期刊论文

Non-negativematrix factorization based unmixing for principal component transformed hyperspectral data

Xiu-rui GENG,Lu-yan JI,Kang SUN

期刊论文

Principle of maximum entropy for reliability analysis in the design of machine components

Yimin ZHANG

期刊论文

optimization of cutting parameters in high-speed milling based on grey relational analysis coupled with principal

Tao FU, Jibin ZHAO, Weijun LIU

期刊论文

Fractional order extremum seeking approach for maximum power point tracking of photovoltaic panels

Ammar NEÇAIBIA,Samir LADACI,Abdelfatah CHAREF,Jean Jacques LOISEAU

期刊论文

The combined effects of biomass and temperature on maximum specific ammonia oxidation rate in domestic

期刊论文

Topology optimization of transient problem with maximum dynamic response constraint using SOAR scheme

期刊论文

工程监理委托代理关系中激励约束与参与约束的研究

秦旋

期刊论文

Maximum entropy based finite element analysis of porous media

Emad NOROUZI, Hesam MOSLEMZADEH, Soheil MOHAMMADI

期刊论文

一种基于主成分分析的企业并购目标遴选综合评价模型探讨

罗一新

期刊论文