Arbitrary-order fractance approximation circuits with high order-stability characteristic and wider approximation frequency bandwidth

Author(s):  
Qiu-Yan He ◽  
Yi-Fei Pu ◽  
Bo Yu ◽  
Xiao Yuan
2003 ◽  
Vol 208 ◽  
pp. 305-314 ◽  
Author(s):  
Atsushi Kawai ◽  
Junichiro Makino

We invented the pseudoparticle multipole method (P2M2), a method to express multipole expansion by a distribution of pseudoparticles. We can use this distribution of particles to calculate high order terms in both the Barnes-Hut treecode and FMM. The primary advantage of P2M2 is that it works on GRAPE. Although the treecode has been implemented on GRAPE, we could handle terms only up to dipole, since GRAPE can calculate forces from point-mass particles only. Thus the calculation cost grows quickly when high accuracy is required. With P2M2, the multipole expansion is expressed by particles, and thus GRAPE can calculate high order terms. Using P2M2, we realized arbitrary-order treecode on MDGRAPE-2. Timing result shows MDGRAPE-2 accelerates the calculation by a factor between 20 (for low accuracy) to 150 (for high accuracy). We parallelized the code so that it runs on MDGRAPE-2 cluster. The calculation speed of the code shows close-to-linear scaling up to 16 processors for N ≳ 106.


2004 ◽  
Vol 2004 (13) ◽  
pp. 647-678 ◽  
Author(s):  
Xifang Cao ◽  
Hongyou Wu

We consider some geometric aspects of regular eigenvalue problems of an arbitrary order. First, we clarify a natural geometric structure on the space of boundary conditions. This structure is the base for studying the dependence of eigenvalues on the boundary condition involved, and reveals new properties of these eigenvalues. Then, we solve the selfadjointness condition explicitly and obtain a manifold structure on the space of selfadjoint boundary conditions and several other consequences. Moreover, we give complete characterizations of several subsets of boundary conditions such as the set of all complex boundary conditions having a given complex number as an eigenvalue, and describe some of them topologically. The shapes of some of these subsets are shown to be independent of the quasidifferential equation in question.


2012 ◽  
Vol 11 (5) ◽  
pp. 1415-1438 ◽  
Author(s):  
Zhenning Cai ◽  
Ruo Li ◽  
Yanli Wang

AbstractThis paper is a continuation of our earlier work [SIAM J. Sci. Comput., 32(2010), pp. 2875-2907] in which a numerical moment method with arbitrary order of moments was presented. However, the computation may break down during the calculation of the structure of a shock wave with Mach number M0≥ 3. In this paper, we concentrate on the regularization of the moment systems. First, we apply the Maxwell iteration to the infinite moment system and determine the magnitude of each moment with respect to the Knudsen number. After that, we obtain the approximation of high order moments and close the moment systems by dropping some high-order terms. Linearization is then performed to obtain a very simple regularization term, thus it is very convenient for numerical implementation. To validate the new regularization, the shock structures of low order systems are computed with different shock Mach numbers.


2015 ◽  
Vol 12 (01) ◽  
pp. 1-35 ◽  
Author(s):  
David Hilditch ◽  
Ronny Richter

We study properties of evolution equations which are first order in time and arbitrary order in space (FTNS). Following Gundlach and Martín-García (2006) we define strong and symmetric hyperbolicity for FTNS systems and examine the relationship between these definitions, and the analogous concepts for first-order systems. We demonstrate equivalence of the FTNS definition of strong hyperbolicity with the existence of a strongly hyperbolic first-order reduction. We also demonstrate equivalence of the FTNS definition, up to N = 4, of symmetric hyperbolicity with the existence of a symmetric-hyperbolic first-order reduction.


2012 ◽  
Vol 3 (1) ◽  
pp. 11
Author(s):  
Ahmed Elaraby Ahmed ◽  
Hassan El-Owny

In this paper we present the new complex form for affine arithmetic (AA) which is a self-verifying computational approach that keeps track of first-order correlation between uncertainties in the data and intermediate and final results. In this paper we propose a higher-order extension satisfying the requirements of genericity, arbitrary-order and self-verification, comparing the resulting method with other wellknown high-order extensions of AA


Author(s):  
Ilan Rusnak ◽  
Gyo¨rgy Hexner

The problem of derivation of guidance laws based on the differential games formalism for high order and acceleration constrained missile and target is formulated. The objective used is the minimaximization of the square of the miss and of the energy expenditure of the players. Explicit formula of the guidance law based on differential game formulation for unconstrained arbitrary order minimum or non-minimum phase is derived. For constrained players with this approach numerous cases emerge. For constrained players only implicit formulas of the GL are derivable. Each case has different structure of the implicit formulas. The cases that are treated-classified are created for different player’s transfer functions, i.e. missile or target autopilot transfer functions are minimum or non-minimum phase, respectively. Relatively tractable case is when the missile and the target are both minimum phase (or belong to a wider class of autopilot transfer functions with monotonous ramp response). For the case of constrained missile and target, implicit formula of the guidance law are derived and numerically solved. For minimum phase players one would guess, from results of one sided optimization, that the GL for constrained players would be obtained by limiting the acceleration commands derived as if there were not acceleration limits. It is shown that although this may be considered a practical-pragmatic solution it is strictly suboptimal.


2015 ◽  
Vol 15 (2) ◽  
pp. 111-134 ◽  
Author(s):  
Joubine Aghili ◽  
Sébastien Boyaval ◽  
Daniele A. Di Pietro

AbstractThis paper presents two novel contributions on the recently introduced Mixed High-Order (MHO) methods [`Arbitrary order mixed methods for heterogeneous anisotropic diffusion on general meshes', preprint (2013)]. We first address the hybridization of the MHO method for a scalar diffusion problem and obtain the corresponding primal formulation. Based on the hybridized MHO method, we then design a novel, arbitrary order method for the Stokes problem on general meshes. A full convergence analysis is carried out showing that, when independent polynomials of degree k are used as unknowns (at elements for the pressure and at faces for each velocity component), the energy-norm of the velocity and the L2-norm of the pressure converge with order (k + 1), while the L2-norm of the velocity (super-)converges with order (k + 2). The latter property is not shared by other methods based on a similar choice of unknowns. The theoretical results are numerically validated in two space dimensions on both standard and polygonal meshes.


2015 ◽  
Vol 119 (1216) ◽  
pp. 765-779
Author(s):  
B. Kada

AbstractThe paper presents a new missile autopilot system design. The design is achieved through the pole-placement in quasi-continuous high-order sliding mode gains adjustment. Enhanced performance, strong robustness and smooth control are obtained through arbitrary increase of the number of non-oscillatory stable poles. The target application of this technique the two-channel pitch/yaw missile autopilot system is considered. Numerical simulations indicate that the arbitrary-order sliding modes based pole placement’s performance compares favourably against recently proposed high-order pole placement schemes.The proposed arbitrary-order pole placement scheme presents a promising design tool for finite-time stabilisation and control of uncertain multivariable systems.


2012 ◽  
Vol 15 (06) ◽  
pp. 1250044 ◽  
Author(s):  
AKIHIKO TAKAHASHI ◽  
KOHTA TAKEHARA ◽  
MASASHI TODA

This paper presents a new computational scheme for an asymptotic expansion method of an arbitrary order. The asymptotic expansion method in finance initiated by Kunitomo and Takahashi (1992), Yoshida (1992b) and Takahashi (1995, 1999) is a widely applicable methodology for an analytic approximation of expectation of a certain functional of diffusion processes. Hence, not only academic researchers but also many practitioners have used the methodology for a variety of financial issues such as pricing or hedging complex derivatives under high-dimensional underlying stochastic environments. In practical applications of the expansion, a crucial step is calculation of conditional expectations for a certain kind of Wiener functionals. Takahashi (1995, 1999) and Takahashi and Takehara (2007) provided explicit formulas for those conditional expectations necessary for the asymptotic expansion up to the third order. This paper presents the new method for computing an arbitrary-order expansion in a general diffusion-type stochastic environment, which is powerful especially for high-order expansions: We develops a new calculation algorithm for computing coefficients of the expansion through solving a system of ordinary differential equations that is equivalent to computing the conditional expectations directly. To demonstrate its effectiveness, the paper gives numerical examples of the approximation for a λ-SABR model up to the fifth order.


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