ISSN:0044-2267    

DOI:10.1002/zamm.19970770202

出版商:WILEY‐VCH Verlag    

年代:1997

数据来源: WILEY

摘要:

AbstractA simple bifurcation point y* of the nonlinear equation F(y) = 0 with a function F : ℝn + 1→ ℝncan be characterized by a so‐called minimally extended system G(z) = 0 where G : ℝn + 2→ ℝn + 2is chosen such that z* = (y*, 0) is a regular solution of this system in the sense that the Jacobian ∂zG(z*) is nonsingular. Hence, y* can be computed by applying superlinearly convergent Newton type methods. A general principle for obtaining such minimally extended systems is described which, as special cases, yields the systems proposed in the literature byGriewankandReddien[5],Pönisch[9], andJanovský[7]. Moreover, an improvement of Pönisch's method is given, and some numerical aspects of implementing the methods and optimally choosing free parame

ISSN:0044-2267    

DOI:10.1002/zamm.19970770203

出版商:WILEY‐VCH Verlag    

年代:1997

数据来源: WILEY

ISSN:0044-2267    

DOI:10.1002/zamm.19970770204

出版商:WILEY‐VCH Verlag    

年代:1997

数据来源: WILEY

摘要:

AbstractThe Dutch gas company “Gasunie” has as one of its main policies, always meeting fluctuating demands, even in case of sudden changes of temperature. Gas originates roughly from three locations which have different gas qualities. A fast and flexible algorithm is needed to determine the quantities of gasses to be mixed and transported. In this paper the advantages of piecewise linear and network programming are combined to a simplex‐like algorithm, that speeds up the recently used algorithms with at least a fact

ISSN:0044-2267    

DOI:10.1002/zamm.19970770207

出版商:WILEY‐VCH Verlag    

年代:1997

数据来源: WILEY

摘要:

AbstractThe paper presents a method of estimating the exit time of vibratory signals in monitoring systems into areas assigned to emergency states. It refers to the methods of the analysis of dynamic systems' stochastic trajectories, including the method of “functionals supporting the availability areas”. A simple model of a system “rotorbearing” was accepted as the basis for the derivation of the estimation dependencies of the time of the disturbance occurrences in a monitored bearing nod. The system is given by a model of an elastic, symmetrical rotor with the mass concentrated in the centre, and supported by two identical slide b

ISSN:0044-2267    

DOI:10.1002/zamm.19970770208

出版商:WILEY‐VCH Verlag    

年代:1997

数据来源: WILEY

摘要:

AbstractThe paper is concerned with the problem of the conductivity of double‐periodic composite materials with circular inclusions. Rayleigh's sum S2has been calculated for each double‐periodic structure. An exact formula for the tensor of effective conductivity is gi

ISSN:0044-2267    

DOI:10.1002/zamm.19970770209

出版商:WILEY‐VCH Verlag    

年代:1997

数据来源: WILEY

摘要:

AbstractA system of differential equations is derived from Biot's constitutive and motion equations for a poroelastic material and a model for a one‐layer seabed is constructed. A normal modes representation for pressure in the far field is found in the case of constant parameters. The model's prediction for transmission loss is examined for five different types of sediments and compared to the predictions of a solid elastic halfspace mode

ISSN:0044-2267    

DOI:10.1002/zamm.19970770210

出版商:WILEY‐VCH Verlag    

年代:1997

数据来源: WILEY

ISSN:0044-2267    

DOI:10.1002/zamm.19970770206

出版商:WILEY‐VCH Verlag    

年代:1997

数据来源: WILEY

摘要:

AbstractIn this work we use a frame‐independent version of the co‐rotational derivative of a motion, and study the geometry defined by this derivative on classical space‐time. This is done in the general framework of derivatives, called Spins, which define a rigid parallel translation of space‐like vectors. We express the Spin itself in terms of this translation, and show that for a non‐uniform Spin this translation depends on the path. Since the co‐rotational derivative is a Spin, its geometry is studied in this context. After showing that the relative vorticity of two motions is the difference of their co‐rotational derivatives, we prove that the translation defined by the co‐rotational derivative of a motion is path‐independent, if and only if the moti

ISSN:0044-2267    

DOI:10.1002/zamm.19970770211

出版商:WILEY‐VCH Verlag    

年代:1997

数据来源: WILEY

摘要:

AbstractThe stability of a two state process periodically driven inverted double pendulum is considered by Floquet's theory. A stability criterion is derived and numerically analysed. For some values of the excitation a stabilization is indeed possible. The corresponding parameter region is inside of the parameter region where a single pendulum is stabilized.

ISSN:0044-2267    

DOI:10.1002/zamm.19970770212

出版商:WILEY‐VCH Verlag    

年代:1997

数据来源: WILEY