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functional derivatives

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Rendiconti del Circolo Matematico di Palermo 1965年第3期14卷 267-277页

作者： Allgower, Eugene Sacramento U.S.A.

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The research of SOL treated cantilever beam based on analytical methods and ANSYS

The research of SOL treated cantilever beam based on analyti...

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2nd International Conference on Multi-functional Materials and Structures

作者： Cao Yin-ping Shi Xiu-hua NW Polytech Univ Xian 710072 Shanxi Peoples R China

ISBN: (纸本)9780878493043

SOL (stand-off layer) damping treatment is the most effective method to improve the damping characteristics of the base structure compared with unconstrained and constrained layer damping treatment. In this case, the viscoelastic layer is sandwiched between the SOL and the constraining layer. During vibration, the SOL acts as a strain magnifier which magnifies the shear strain in the viscoelastic layer by increasing the distance between the viscoelastic layer and the neutral axis of the base structure thus dissipates more vibration energy. The equations of motion root in kinematic equations, constitutive equations and equilibrium equations of force and moment, and constitute one variable (lateral deflection) with 4(th) order differential equation and two variables (axial deflections of the base beam and the constraining layer) with 2(nd) order differential equation of motion. Together with the boundary conditions, the transfer function method and the finite element method are adopted to analyze the damping characteristics of the composite structure. In distributed function method, the equations are transferred to state space form. In finite element method, the lateral deflection is interpolated by Hermite interpolation function and the axial deflections of the base layer and the constraining layer are interpolated by Lagrange interpolation function. At last, the predictions of the two analytical methods are validated against the commercial software ANSYS. Close agreements are found among the three methods. To achieve the expected effect, the SOL must have high shear stiffness and low bending stiffness so it does not significantly influence the flexural rigidity of the base structure but does not absorb the shear stress desired to be passed on to the viscoelastic layer. This paper is focus the application of SOL damping treatment on cantilever beam model, but it is essential to note that the model can be extended to complex structures such as plates and shells. We ca

关键词： SOL transfer function method Finite element method interpolation function ANSYS

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Estimation of the Postmortem Interval by Measuring Blood Oxidation‑reduction Potential Values

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Journal of Forensic Science and Medicine 2016年第1期2卷 8-11页

作者： Zhuqing Jiang Meng You Xu Wang Di Lu Haidong Zhang Shengli Di Fengqin Zhang Zhaoming Guo Xiaofei E Lin Chang Jian Xiang Rufeng Bai Tiantong Yang Center of Cooperative Innovation for Judicial Civilization China University of Political Science and Law&Jilin University&Wuhan University China University of Political Science and Law Key Laboratory of Evidence ScienceMinistry of EducationBeijing 100040China

Accurate estimation of the postmortem interval(PMI)is an important task in forensic *** the last half-century,the use of postmortem biochemistry has become an important ancillary method in determining the time of *** present study was carried out to determine the correlation between blood oxidation-reduction potential(ORP)values and PMIs,and to develop a three-dimensional surface equation to estimate the PMI under various temperature conditions.A total of 48 rabbits were placed into six groups and sacrificed by air *** was obtained from the right ventricle of each rabbit,and specimens were stored at 10℃,15℃,20℃,25℃,30℃,and 35℃.At different PMIs(once every 4 h),the blood ORP values were measured using a PB-21 electrochemical *** analysis and curve fitting of the data yielded cubic polynomial regression equations and a surface equation at different ***:The results showed that there was a strong positive correlation between the blood ORP values at different temperatures and the *** study provides another example of using a three-dimensional surface equation as a tool to estimate the PMI at various temperature conditions.

关键词： Forensic science interpolation function oxidation‑reduction potential postmortem interval three‑dimensional surface equation

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Research on Crowd Behavior Based on the Velocity Field

Research on Crowd Behavior Based on the Velocity Field

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2015 4th National Conference on Electrical,Electronics and Computer Engineering(NCEECE 2015)

作者： Yuan Fang Ma Ke Liang Jia-hong Chao Yong-jing College of Information Systems and Management National University of Defense Technology Aviation University of Air Force

ISBN: (纸本)9781510819085

Data-driven modeling method has become an ideal research method in crowd behavior simulation fields. The basic idea of data-driven modeling method is that velocity field generated by the crowd behavior characteristic information. Because of the video data acquisition, the velocity field has its limitation, namely virtual crowd simulation scenario should be consistent with the crowd scene of video data. So we present an optimization strategy: first, it eliminates velocity of scene from the generated velocity field;And second, it constructs velocity field by interpolation again. Experiments show that the presented optimization strategy can design the velocity field without scene information, and it is helpful to improve the universality of the velocity field.

关键词： crowd behavior velocity field Gaussian filter Horn-Schunck algorithm interpolation function

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A nonlinear least-squares graphical tool ('Gaussfit') for educational purposes

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INTERNATIONAL JOURNAL OF ELECTRICAL ENGINEERING EDUCATION 2010年第1期47卷 11-22页

作者： Malaric, Kresimir Malaric, Roman Hegedus, Hrvoje Univ Zagreb Fac Elect Engn & Comp Zagreb 41000 Croatia

This paper describes a computer program that finds a function which closely approximates experimental data using the least-squares method. The program finds parameters of the function as well as their corresponding uncertainties. It also has a subroutine for graphical presentation of the input data and the function. The program is used for educational purposes at undergraduate level for students who are learning least-squares fitting, how to solve systems of linear equations and about computer calculation errors.

关键词： computer errors interpolation function least-squares method polynomials

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A new approach to RF small-signal modeling of MOSFETs

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SEMICONDUCTOR SCIENCE AND TECHNOLOGY 2019年第11期34卷 115024-115024页

作者： Jawa, Himani Dutta, Aloke K. IIT Kanpur Dept Elect Engn Kanpur 208016 UP India

In this paper, we present a new approach to obtain the RF small-signal parameters of MOSFETs, by developing region-wise (strong- and weak-inversion) physics-based small-signal models for the intrinsic part of the device, and eventually coupling them over the moderate inversion region through the use of an interpolation function. The basic premise of this approach is the fact that there is a large difference between the magnitudes of the depletion and inversion charge densities in strong- and weak-inversion regions. The expressions for the Y-parameters are obtained in a power series form, truncated up to the second-order, which is enough to retain sufficient accuracy. Since only the intrinsic parameters are not sufficient to predict the high frequency behavior of short-channel devices, hence, extrinsic parameters are coupled with their intrinsic counterparts in order to obtain the total values of the Y-parameters for the complete device. The results of our model show a sufficiently good match with the TCAD simulations. Also, the continuity of the various device capacitances at a frequency of 50 GHz over the entire range of gate bias validates our model.

关键词： interpolation function intrinsic model linearization technique MOSFETs RF Y-parameters

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Electromechanical coupling enriched finite element method for dynamic characteristic of piezoelectric materials structures

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MECHANICS OF ADVANCED MATERIALS AND STRUCTURES 2024年第25期31卷 6803-6816页

作者： Sha, Lirong Sun, Hongfei Wang, Yajin Zhou, Liming Jilin Jianzhu Univ Sch Civil Engn Changchun Peoples R China Jilin Univ Sch Mech & Aerosp Engn Renmin St 5988 Changchun 130025 Jilin Peoples R China

To improve the application depth and breadth of intelligent unit devices made from piezoelectric structures, their kinetic properties shall be urgently studied. Herein, based on the basic equations and boundary conditions of piezoelectric materials, an interpolation coverage function of node displacement was introduced into the displacement shape function and potential shape function of coupling electromechanical finite element method (FEM), forming an electromechanical coupling enriched FEM generalized shape function. Together with the variation principle, an electromechanical coupling enriched FEM was put forward, and its motion equations were deduced. Next, the free vibration and transient response of the piezoelectric structure were analyzed, and the accuracy and validity of the new method were validated with numerical cases. Results show this method has high application prospects for analyzing the dynamic properties of piezoelectric material structures.

关键词： Enriched finite element method coupling electromechanical dynamic characteristic piezoelectric structures interpolation function

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Conditions for avoiding the checkerboard distortion in continuous-time domain

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ELECTRONICS AND COMMUNICATIONS IN JAPAN PART III-FUNDAMENTAL ELECTRONIC SCIENCE 2001年第12期84卷 59-68页

作者： Murakami, M Kiya, H Tokyo Metropolitan Univ Grad Sch Engn Dept Elect Engn Hachioji Tokyo 1920397 Japan

Checkerboard distortion is the kind generated in the sampling rate converter using a digital filter. In this paper, such distortion is studied in the continuous-time domain. The distortion is newly defined in the problem of interpolation by a continuous interpolation function and conditions for avoiding the checkerboard distortion are derived. Further, it is shown that a digital filter that does not generate checkerboard distortion can be created by an appropriate sampling to the continuous interpolation function satisfying the conditions in this paper. The relationship between the continuous interpolation function with time scale transform and the checkerboard distortion is studied. (C) 2001 Scripta Technica, Electron Comm Jpn Pt 3, 84(12): 59-68, 2001.

关键词： interpolation function checkerboard distortion sampling rate transform filter

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A point interpolation method for two-dimensional solids

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INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING 2001年第4期50卷 937-951页

作者： Liu, GR Gu, YT Natl Univ Singapore Dept Mech & Prod Engn Singapore 119260 Singapore

A point interpolation method (PIM) is presented for stress analysis for two-dimensional solids. In the PIM, the problem domain is represented by properly scattered paints. A technique is proposed to construct polynomial interpolants with delta function property based only on a group of arbitrarily distributed points. The PIM equations are then derived using variational principles. In the PIM, the essential boundary conditions can be implemented with ease as in the conventional finite element methods. The present PIM has been coded in FORTRAN. The validity and efficiency of the present PIM formulation are demonstrated through example problems. It is found that the present PIM is very easy to implement, and very flexible for obtained displacements and stresses of desired accuracy in solids. As the elements are not used for meshing the problem domain, the present PIM opens new avenues to develop adaptive analysis codes for stress analysis in solids and structures. Copyright (C) 2001 John Wiley & Sons, Ltd.

关键词： meshless method element-free method interpolation function stress analysis

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Dynamic thermo-elastic response of a discrete multi-layered cylindrical shell subjected to transient thermal loading

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PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART C-JOURNAL OF MECHANICAL ENGINEERING SCIENCE 2008年第4期222卷 549-561页

作者： Zheng, J. Y. Wu, X. D. Chen, Y. J. Deng, G. D. Li, Q. M. Sun, G. Y. Zhejiang Univ Inst Chem Machinery & Proc Equipment Hangzhou 310027 Peoples R China Univ Manchester Sch Mech Aerosp & Civil Engn Manchester Lancs England

Explosion containment vessels (ECVs) are used to fully contain the effects of explosion events. A discrete multi-layered cylindrical shell (DMC) consisting of a thin inner cylindrical shell and helically cross-winding flat steel ribbons has been proposed, which has obvious advantages of fabrication convenience and low costs. The applications of ECVs are closely associated with blast and thermal loads, and thus, it is important to understand the response of a DMC under transient thermal load in order to develop a design code and operation procedures for the use of DMC as ECV. In this paper, a mathematical model for the elastic response of a DMC subjected to thermal loading due to rapid heating is proposed. Based on the axisymmetric plane strain assumption, the displacement solution of the dynamic equilibrium equations of both inner shell and outer ribbon layer are decomposed into two parts, i.e. a thermo-elastic part satisfying inhomogeneous stress boundary conditions and a dynamic part for homogeneous stress boundary conditions. The thermo-elastic part is solved by a linear method and the dynamic part is determined by means of finite Hankel transform and Laplace transform. The thermo-elastic solution of a DMC is compared with the solution of a monobloc cylindrical shell, and numerical results are presented and discussed in terms of winding angle and material parameters.

关键词： explosion mechanics explosion containment vessels discrete multi-layered cylindrical shells integral transformation dynamic thermo-elastic response interpolation function

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