scholarly journals Closed-form representation for equivalent electromagnetic parameters of irregular hexagonal honeycomb radar-absorbing materials

AIP Advances ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 095021
Author(s):  
Guanya Li ◽  
Haiyan Chen ◽  
Qingting He ◽  
Li Zhang ◽  
Xiaolong Weng ◽  
...  
Keyword(s):  
Closed Form ◽  
Electromagnetic Parameters ◽  
Form Representation ◽  
Absorbing Materials

Closed-form representation for equivalent electromagnetic parameters of biaxial anisotropic honeycomb absorbing materials

2019 ◽  
Vol 6 (8) ◽  
pp. 085804 ◽  
Author(s):  
Haiyan Chen ◽  
Rongbo Shen ◽  
Liandi Han ◽  
Yang Zhou ◽  
Fengxia Li ◽  
...  
Keyword(s):  
Closed Form ◽  
Electromagnetic Parameters ◽  
Form Representation ◽  
Absorbing Materials

scholarly journals Harmonic Numbers and Cubed Binomial Coefficients

2011 ◽  
Vol 2011 ◽  
pp. 1-14
Author(s):  
Anthony Sofo
Keyword(s):  
Closed Form ◽  
Binomial Coefficients ◽  
Harmonic Numbers ◽  
Polygamma Functions ◽  
Form Representation ◽  
The Given

Euler related results on the sum of the ratio of harmonic numbers and cubed binomial coefficients are investigated in this paper. Integral and closed-form representation of sums are developed in terms of zeta and polygamma functions. The given representations are new.

Characterization and Design of Honeycomb Absorbing Materials

2019 ◽  
Vol 294 ◽  
pp. 51-56
Author(s):  
Hui Min Sun ◽  
Le Chen ◽  
Zhao Zhan Gu
Keyword(s):  
Double Layer ◽  
Low Frequency ◽  
Single Layer ◽  
Electromagnetic Parameters ◽  
Honeycomb Sandwich ◽  
Absorbing Materials ◽  
Absorbing Material ◽  
The Difference ◽  
Free Space Method ◽  
Honeycomb Sandwich Structure

Honeycomb absorbing materials are anisotropic structural materials. Depending on the size of honeycomb lattices, the absorbent content of the impregnated layer is different, the thickness of the impregnated layer is different, and the absorbing function of the impregnated honeycomb absorbing materials is also different. For the characterization of electromagnetic parameters of honeycomb absorbing materials, this paper adopts free space method for testing, uses CST software for modeling, and inverts the electromagnetic parameters of honeycomb absorbing structures. The absorbing performance of single-layer and double-layer honeycomb sandwich structures was simulated by RAM Optimizer software. The research shows that the height of the single-layer honeycomb absorbing material is 22mm. When the absorber content is 65%, 75% and 85% respectively, the harmonic peak moves slightly to the low frequency electromagnetic wave with the increase of the absorber content, but the absorbing strength decreases with the increase of the absorber content. For the double-layer honeycomb sandwich structure, the difference of absorber content in the upper and lower honeycomb absorbing materials is smaller, and the absorbing performance is stronger. When the thickness of the wave-transparent panel is thinner, the harmonic peak of the absorbing curve moves slightly to the high frequency.

Closed-Form Representation of Beam Response to Moving Line Loads

2000 ◽  
Vol 68 (2) ◽  
pp. 348-350 ◽  
Author(s):  
Lu Sun
Keyword(s):  
Closed Form ◽  
Moving Load ◽  
Closed Form Solution ◽  
Form Solution ◽  
Winkler Foundation ◽  
Line Load ◽  
State Response ◽  
Form Representation ◽  
Mach Numbers ◽  
Moving Line

Fourier transform is used to solve the problem of steady-state response of a beam on an elastic Winkler foundation subject to a moving constant line load. Theorem of residue is employed to evaluate the convolution in terms of Green’s function. A closed-form solution is presented with respect to distinct Mach numbers. It is found that the response of the beam goes to unbounded as the load travels with the critical velocity. The maximal displacement response appears exactly under the moving load and travels at the same speed with the moving load in the case of Mach numbers being less than unity.

scholarly journals Optimal Investment of DC Pension Plan under Incentive Schemes and Loss Aversion

2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Yinghui Dong ◽  
Wenxin Lv ◽  
Siyuan Wei ◽  
Yeyang Gong
Keyword(s):  
Closed Form ◽  
Loss Aversion ◽  
Pension Plan ◽  
Optimal Investment ◽  
Numerical Results ◽  
Managerial Compensation ◽  
Incentive Schemes ◽  
Terminal Wealth ◽  
Portfolio Problem ◽  
Form Representation

We investigate the DC pension manager’s portfolio problem when the manager is remunerated through two schemes for DC pension managerial compensation under loss aversion and minimum guarantee. We apply the concavification technique and a static Lagrangian technique to solve the problem and derive the closed-form representation of the optimal wealth and portfolio processes. Theoretical and numerical results show that the incentive schemes can significantly impact the distribution of the optimal terminal wealth.

scholarly journals Identity-Type Functions and Polynomials

2007 ◽  
Vol 2007 ◽  
pp. 1-10
Author(s):  
M. Aslam Chaudhry ◽  
Asghar Qadir
Keyword(s):  
Differential Equation ◽  
Functional Equation ◽  
Boundary Conditions ◽  
Linear Differential Equation ◽  
Closed Form ◽  
Order Linear Differential Equation ◽  
Specific Function ◽  
Type Function ◽  
Form Representation ◽  
Linear Differential

For a noncommuting product of functions, similar to convolutions, an “identity-type function” leaving a specific function invariant is defined. It is evaluated for any choice of function on which it acts by solving a functional equation. A closed-form representation for the identity-type function of(1+t)−b(b>0)is obtained, which is a solution of a second-order linear differential equation with given boundary conditions. It yields orthogonal polynomials whose graphs are also given. The relevance for solution of boundary value problems by a series and convergence of the series are briefly discussed.

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