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期刊论文 36

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Gompertz分布 1

PID控制 1

SARS 1

上行非正交多址;Generalized Welch界等式;多级接收功率;序列分组 1

上限法 1

不确定性信息 1

不确定性数学(UM) 1

人脸识别 1

兆瓦级电力电子 1

关系 1

关联流动法则 1

关键因子;非线性计数系统;广义高斯过程回归;敏感性分析;钢铁轧制过程 1

卫星遥感—地基 1

四元数傅里叶变换;四元数线性正则变换;采样定理;部分和总体四元数希尔伯特变换;部分和总体广义四元数希尔伯特变换;截断误差 1

基本结构 1

塑性势 1

多机动目标跟踪;多模型;广义标签多伯努利滤波器;多目标混合系统 1

多目标跟踪;广义标签多伯努利;辐射源信号特征;模糊C-均值;动态聚类 1

多符号差分检测;广义似然比检验;半定松弛;双向中继传输 1

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Isogeometric analysis of coupled thermo-elastodynamic problems under cyclic thermal shock

Asghar AMANI DASHLEJEH

《结构与土木工程前沿(英文)》 2019年 第13卷 第2期   页码 397-405 doi: 10.1007/s11709-018-0473-7

摘要: The isogeometric analysis (IGA) method was extended for the solution of the coupled thermo-elastodynamic equations. The dimensionless formulation was accepted in discretization of the uncoupled and coupled thermoelasticity equations and the Generalized Newmark method was used in the time integration procedure. First, the performance of the proposed method was verified against a two-dimensional benchmark example subjected to constant thermal shock with available exact analytical solutions. Then a two-dimensional half-space benchmark example under thermal shock was solved. Finally, cyclic thermal shock (CTS) loading was applied on the half-space problem. The results dedicated that IGA can be used as a suitable approach in the analysis of the general thermomechanical problems.

关键词: isogeometric analysis     coupled thermo-elastodynamic     dynamic analysis     generalized newmark     cyclic thermal shock    

Isomorphism analysis on generalized modules oriented to the distributed parameterized intelligent product

Shasha ZENG, Weiping PENG, Tiaoyu LEI

《机械工程前沿(英文)》 2020年 第15卷 第1期   页码 12-23 doi: 10.1007/s11465-019-0555-9

摘要: The distributed parameterized intelligent product platform (DPIPP) contains many agents of a product minimum approximate autonomous subsystem (generalized module). These distributed agents communicate, coordinate, and cooperate using their knowledge and skills and eventually accomplish the design for mass customization in a loosely coupled environment. In this study, a new method of isomorphism analysis on generalized modules oriented to DPIPP is proposed. First, on the basis of the bill of material partition and generalized module mining, the parameters of the main characteristics are extracted to construct the main characteristic parameter matrix. Second, similarity calculation of generalized modules is realized by improving the clustering using representatives algorithm, and isomorphism model sets are obtained. Generalized modules with a similar structure are combined to complete the isomorphism analysis. The effectiveness of the proposed method is verified by taking high- and medium-pressure valve data as an example.

关键词: distributed parameterized intelligent product platform     generalized module     isomorphism analysis     product family    

Novel method of constructing generalized Hoberman sphere mechanisms based on deployment axes

Xuemin SUN, Yan-An YAO, Ruiming LI

《机械工程前沿(英文)》 2020年 第15卷 第1期   页码 89-99 doi: 10.1007/s11465-019-0567-5

摘要: This study proposes a method of constructing type II generalized angulated elements (GAEs II) Hoberman sphere mechanisms on the basis of deployment axes that intersect at one point. First, the constraint conditions for inserting GAEs II into deployment axes to form a loop are given. The angle constraint conditions of the deployment axes are obtained through a series of linear equations. Second, the connection conditions of two GAEs II loops that share a common deployable center are discussed. Third, a flowchart of constructing the generalized Hoberman sphere mechanism on the basis of deployment axes is provided. Finally, four generalized Hoberman sphere mechanisms based on a fully enclosed regular hexahedron, arithmetic sequence axes, orthonormal arithmetic sequence axes, and spiral-like axes are constructed in accordance with the given arrangement of deployment axes that satisfy the constraint conditions to verify the feasibility of the proposed method.

关键词: deployable mechanism     type II generalized angulated elements     Hoberman sphere mechanism     deployment axes     constraint conditions    

Multiscale RBF-based central high resolution schemes for simulation of generalized thermoelasticity problems

Hassan YOUSEFI, Alireza TAGHAVI KANI, Iradj MAHMOUDZADEH KANI

《结构与土木工程前沿(英文)》 2019年 第13卷 第2期   页码 429-455 doi: 10.1007/s11709-018-0483-5

摘要: In this study, average-interpolating radial basis functions (RBFs) are successfully integrated with central high-resolution schemes to achieve a higher-order central method. This proposed method is used for simulation of generalized coupled thermoelasticity problems including shock (singular) waves in their solutions. The thermoelasticity problems include the LS (systems with one relaxation parameter) and GN (systems without energy dissipation) theories with constant and variable coefficients. In the central high resolution formulation, RBFs lead to a reconstruction with the optimum recovery with minimized roughness on each cell: this is essential for oscillation-free reconstructions. To guarantee monotonic reconstructions at cell-edges, the nonlinear scaling limiters are used. Such reconstructions, finally, lead to the total variation bounded (TVB) feature. As RBFs work satisfactory on non-uniform cells/grids, the proposed central scheme can handle adapted cells/grids. To have cost effective and accurate simulations, the multiresolution–based grid adaptation approach is then integrated with the RBF-based central scheme. Effects of condition numbers of RBFs, computational complexity and cost of the proposed scheme are studied. Finally, different 1-D coupled thermoelasticity benchmarks are presented. There, performance of the adaptive RBF-based formulation is compared with that of the adaptive Kurganov-Tadmor (KT) second-order central high-resolution scheme with the total variation diminishing (TVD) property.

关键词: central high resolution schemes     RBFs     higher order accuracy     generalized thermoelasticity     multiresolution-based adaptation    

Design and analysis of the gripper mechanism based on generalized parallel mechanisms with configurable

《机械工程前沿(英文)》 2021年 第16卷 第4期   页码 765-781 doi: 10.1007/s11465-021-0655-1

摘要: Generalized parallel mechanisms with a configurable moving platform have become popular in the research field of parallel mechanism. This type of gripper mechanism can be applied to grasp large or heavy objects in different environments that are dangerous and complex for humans. This study proposes a family of novel (5 + 1) degrees of freedom (three translations and two rotations plus an additional grasping motion) gripper mechanisms based on the generalized parallel mechanisms with a configurable moving platform. First, the configurable moving platform, which is a closed loop, is designed for grasping manipulation. The hybrid topological arrangement is determined to improve the stiffness of the manipulator and realize high load-to-weight ratios. A sufficient rule based on Lie group theory is proposed to synthesize the mechanism. The hybrid limb structure is also enumerated. A family of novel gripper mechanisms can be assembled through the hybrid limbs by satisfying the rule. Two examples of the gripper mechanisms with and without parallelogram pairs are shown in this study. A kinematic analysis of the example mechanism is presented. The workspace shows that the mechanism possesses high rotational capability. In addition, a stiffness analysis is performed.

关键词: generalized parallel mechanism     configurable moving platform     gripper mechanism     type synthesis     kinematic analysis    

An approach for mechanical fault classification based on generalized discriminant analysis

LI Wei-hua, SHI Tie-lin, YANG Shu-zi

《机械工程前沿(英文)》 2006年 第1卷 第3期   页码 292-298 doi: 10.1007/s11465-006-0022-2

摘要: To deal with pattern classification of complicated mechanical faults, an approach to multi-faults classification based on generalized discriminant analysis is presented. Compared with linear discriminant analysis (LDA), generalized discriminant analysis (GDA), one of nonlinear discriminant analysis methods, is more suitable for classifying the linear non-separable problem. The connection and difference between KPCA (Kernel Principal Component Analysis) and GDA is discussed. KPCA is good at detection of machine abnormality while GDA performs well in multi-faults classification based on the collection of historical faults symptoms. When the proposed method is applied to air compressor condition classification and gear fault classification, an excellent performance in complicated multi-faults classification is presented.

关键词: generalized discriminant     non-separable     abnormality     classification     multi-faults classification    

The convexity about ultimate bearing hypersurfaces of structures

Chengxi GUO,Tingting GUO

《结构与土木工程前沿(英文)》 2016年 第10卷 第4期   页码 456-461 doi: 10.1007/s11709-016-0334-1

摘要: The relationship between the convexity on the ultimate bearing surface of a structure and the second-order effects of loads is discussed. All of generalized non-overload forces acted on a structure forms a convex set when ignoring the second-order effects (coupling effects between the generalized forces). It is true also when the Hessian matrix composed of the second-order partial derivatives on the hypersurface about the ultimate bearing of the structure is negative definite. The outward convexity is kept when the surface is expressed by certain dimensionless parameters. A series of properties based on the convexity are pointed out. Some applications in the analysis of bearing capacity of structures were illustrated with examples. The study shows that an evaluation about the bearing capacity state of a complex structure can be made on the basis of several points on the surface of the ultimate bearing of the structure.

关键词: service     limit load     ultimate bearing surface     convexity     generalized force     generalized displacement     frame structure    

Comparisons of bridges flutter derivatives and generalized ones

Fuyou XU , Zhe ZHANG , Cailiang HUANG , Airong CHEN ,

《结构与土木工程前沿(英文)》 2009年 第3卷 第3期   页码 272-278 doi: 10.1007/s11709-009-0042-1

摘要: The causes of the nonlinearity of self-excited aerodynamic force of bridge are interpreted from such two aspects as amplitude and wind velocity. The concept of “generalized flutter derivative” is proposed, and its physical meaning is illustrated. The graphs of the generalized flutter derivatives of plate and Sutong Bridge section model are plotted. The characteristics of all generalized flutter derivatives are compared and analyzed, and their superiorities are verified. The results indicate that the physical meaning of generalized flutter derivatives are more explicit compared to the traditional ones. It is more convenient to understand the nonlinearity properties of self-excited aerodynamic force of bridge according to the generalized flutter derivatives graphs with the wind velocity as the horizontal coordinate.

关键词: bridge     flutter derivative     generalized flutter derivative     self-excited aerodynamic force     Sutong Bridge    

广义塑性力学及其运用

郑颖人,孔亮

《中国工程科学》 2005年 第7卷 第11期   页码 21-36

摘要:

分析了经典塑性力学用于岩土类材料的问题,它采用了3个不符合岩土材料变形机制的假设。从固体力学原理直接导出广义塑性位势理论,将经典塑性力学改造为更一般的塑性力学——广义塑性力学。广义塑性力学采用了塑性力学中的分量理论,能反映应力路径转折的影响,并避免了采用正交流动法则所引起的过大剪胀等不合理现象,也不会产生当前非关联流动法则中任意假定塑性势面引起的误差。给出了广义塑性力学的屈服面理论、硬化定律和应力-应变关系,并建立了考虑应力主轴旋转的广义塑性位势理论。屈服条件是状态参数,也是试验参数,只能由试验给出。应用表明,广义塑性力学可作为岩土材料的建模理论,还可应用于诸如极限分析等土力学的诸多领域,具有广阔的应用前景。

关键词: 岩土塑性力学     广义塑性力学     塑性势     屈服面     本构模型    

广义不确定性系统理论的外延综论

王清印,吕瑞华

《中国工程科学》 2005年 第7卷 第10期   页码 16-22

摘要:

在概述广义不确定性系统内涵基础上,讨论了广义不确定性系统的外延类别及其相关理论的基本研究框架和基本原理,为深入研究广义不确定性系统理论奠定了基础。

关键词: 广义不确定性信息(GUI)     不确定性数学(UM)     广义不确定性系统理论(GUST)    

基于generalized-K信道的SIMO的物理层安全性能分析 Article

Hong-jiang LEI,Imran Shafique ANSARI,Chao GAO,Yong-cai GUO,Gao-feng PAN,Khalid A. QARAQE

《信息与电子工程前沿(英文)》 2016年 第17卷 第10期   页码 1074-1084 doi: 10.1631/FITEE.1601070

摘要: 概要:该文研究了基于generalized-K信道的单发多收系统的物理层安全性能。分别考虑源节点在有和没有窃听信道的信道状态信息的两种情况,将generalized-K分布近似为伽马分布和混合伽马分布,分别推导出系统的保密中断概率和平均保密容量的解析表达式。

关键词: 物理层安全;generalized-K衰落;平均保密容量;保密中断概率;混合伽马分布    

over coldstart operation in the presence of different random noises and uncertainty: Implementation of generalized

Nasser L. AZAD,Ahmad MOZAFFARI

《机械工程前沿(英文)》 2015年 第10卷 第4期   页码 405-412 doi: 10.1007/s11465-015-0354-x

摘要:

The main scope of the current study is to develop a systematic stochastic model to capture the undesired uncertainty and random noises on the key parameters affecting the catalyst temperature over the coldstart operation of automotive engine systems. In the recent years, a number of articles have been published which aim at the modeling and analysis of automotive engines’ behavior during coldstart operations by using regression modeling methods. Regarding highly nonlinear and uncertain nature of the coldstart operation, calibration of the engine system’s variables, for instance the catalyst temperature, is deemed to be an intricate task, and it is unlikely to develop an exact physics-based nonlinear model. This encourages automotive engineers to take advantage of knowledge-based modeling tools and regression approaches. However, there exist rare reports which propose an efficient tool for coping with the uncertainty associated with the collected database. Here, the authors introduce a random noise to experimentally derived data and simulate an uncertain database as a representative of the engine system’s behavior over coldstart operations. Then, by using a Gaussian process regression machine (GPRM), a reliable model is used for the sake of analysis of the engine’s behavior. The simulation results attest the efficacy of GPRM for the considered case study. The research outcomes confirm that it is possible to develop a practical calibration tool which can be reliably used for modeling the catalyst temperature.

关键词: automotive engine     calibration     coldstart operation     Gaussian process regression machine (GPRM)     uncertainty and random noises    

广义不确定性系统理论的基本构思

王清印,郭立田,谢建华,刘志勇

《中国工程科学》 2004年 第6卷 第3期   页码 25-29

摘要:

论述了不确定性系统理论的国内外发展概况,给出了不确定性信息定义及其广义不确定性系统理论(GUST)的定义,论述了广义不确定性系统理论的基本内涵、基本结构及其科学意义。

关键词: 不确定性信息     广义不确定性系统     基本结构    

Mechanism design of reverse auction on concession period and generalized quality for PPP projects

Xianjia WANG, Shiwei WU

《工程管理前沿(英文)》 2017年 第4卷 第2期   页码 156-170 doi: 10.15302/J-FEM-2017016

摘要: Reverse auctions of PPP projects usually require the bid to specify several characteristics of quality and the concession period to be fulfilled. This paper sets up a summary function of generalized quality, which contributes to reducing the dimensions of information. Thus, the multidimensional reverse auction model of a PPP project can be replaced by a two-dimensional direct mechanism based on the concession period and the generalized quality. Based on the theory of the revelation principle, the feasibility conditions, equilibrium solution and generalized quality requirements of such a mechanism, considering the influence of a variable investment structure are described. Moreover, two feasible multidimensional reverse auctions for implementing such a direct mechanism: Adjusting the scoring function and establishing a special reverse auction rule are built. The analysis shows that in these types of reverse auctions, optimal allocation can be achieved, the social benefit under the incomplete information will be maximized, and the private sector with the highest integrated management level wins the bid. In such a direct mechanism, the investment and financial pressure of the public sector can be reduced.

关键词: PPP project     reverse auction     mechanism design     multidimensional information     scoring function     two-stage bidding    

Investigation of Generalized SIFs of cracks in 3D piezoelectric media under various crack-face conditions

Jaroon RUNGAMORNRAT, Bounsana CHANSAVANG, Weeraporn PHONGTINNABOOT, Chung Nguyen VAN

《结构与土木工程前沿(英文)》 2020年 第14卷 第2期   页码 280-298 doi: 10.1007/s11709-019-0586-7

摘要: This paper investigates the influence of crack geometry, crack-face and loading conditions, and the permittivity of a medium inside the crack gap on intensity factors of planar and non-planar cracks in linear piezoelectric media. A weakly singular boundary integral equation method together with the near-front approximation is adopted to accurately determine the intensity factors. Obtained results indicate that the non-flat crack surface, the electric field, and the permittivity of a medium inside the crack gap play a crucial role on the behavior of intensity factors. The mode-I stress intensity factors ( ) for two representative non-planar cracks under different crack-face conditions are found significantly different and they possess both upper and lower bounds. In addition, for impermeable and semi-permeable non-planar cracks treated depends strongly on the electric field whereas those of impermeable, permeable, and semi-permeable penny-shaped cracks are identical and independent of the electric field. The stress/electric intensity factors predicted by permeable and energetically consistent models are, respectively, independent of and dependent on the electric field for the penny-shaped crack and the two representative non-planar cracks. Also, the permittivity of a medium inside the crack gap strongly affects the intensity factors for all crack configurations considered except for of the semi-permeable penny-shaped crack.

关键词: crack-face conditions     intensity factors     non-flat cracks     permittivity     piezoelectric media     SGBEM    

标题 作者 时间 类型 操作

Isogeometric analysis of coupled thermo-elastodynamic problems under cyclic thermal shock

Asghar AMANI DASHLEJEH

期刊论文

Isomorphism analysis on generalized modules oriented to the distributed parameterized intelligent product

Shasha ZENG, Weiping PENG, Tiaoyu LEI

期刊论文

Novel method of constructing generalized Hoberman sphere mechanisms based on deployment axes

Xuemin SUN, Yan-An YAO, Ruiming LI

期刊论文

Multiscale RBF-based central high resolution schemes for simulation of generalized thermoelasticity problems

Hassan YOUSEFI, Alireza TAGHAVI KANI, Iradj MAHMOUDZADEH KANI

期刊论文

Design and analysis of the gripper mechanism based on generalized parallel mechanisms with configurable

期刊论文

An approach for mechanical fault classification based on generalized discriminant analysis

LI Wei-hua, SHI Tie-lin, YANG Shu-zi

期刊论文

The convexity about ultimate bearing hypersurfaces of structures

Chengxi GUO,Tingting GUO

期刊论文

Comparisons of bridges flutter derivatives and generalized ones

Fuyou XU , Zhe ZHANG , Cailiang HUANG , Airong CHEN ,

期刊论文

广义塑性力学及其运用

郑颖人,孔亮

期刊论文

广义不确定性系统理论的外延综论

王清印,吕瑞华

期刊论文

基于generalized-K信道的SIMO的物理层安全性能分析

Hong-jiang LEI,Imran Shafique ANSARI,Chao GAO,Yong-cai GUO,Gao-feng PAN,Khalid A. QARAQE

期刊论文

over coldstart operation in the presence of different random noises and uncertainty: Implementation of generalized

Nasser L. AZAD,Ahmad MOZAFFARI

期刊论文

广义不确定性系统理论的基本构思

王清印,郭立田,谢建华,刘志勇

期刊论文

Mechanism design of reverse auction on concession period and generalized quality for PPP projects

Xianjia WANG, Shiwei WU

期刊论文

Investigation of Generalized SIFs of cracks in 3D piezoelectric media under various crack-face conditions

Jaroon RUNGAMORNRAT, Bounsana CHANSAVANG, Weeraporn PHONGTINNABOOT, Chung Nguyen VAN

期刊论文