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11.
For a knotted surface in -space, its generic projection into -space has branch points as its singularities, and its successive projection into -space has fold points and cusps as its singularities. In this paper, we show that for non-orientable knotted surfaces, the numbers of branch points and cusps can be minimized by isotopy.
12.
Tim Haslett Simon Moss Charles Osborne Paul Ramm 《Nonlinear dynamics, psychology, and life sciences》2000,4(1):67-86
This paper examines the imposition of local rules in five mail delivery centres of Australia Post. Local rules are patterns of behaviour used by subunits of an organization to optimise their payoff. These local rules may ultimately benefit the total organization. Fitness landscapes are used to examine the emergence of local rules in this workplace. This research examined the relationship between the time taken to sort the mail and the volume of this mail. Work rates show a clear catastrophe shift; that is, work rates suddenly drop when the volume of mail exceeds a certain level, as Postal Delivery Officers apply local rules to maximise gains inherent in the pay structures. Such behaviour is close to that predicted by Kauffman (1995) in computer simulations of lattices and may be indicative of the application of local rules in organizations. The implications of the use of local rules are that behaviour in social systems may be dictated by systemic and emergent processes which are outside immediate management control. A further implication is that organizations may be structured to a significant extent by such local rules. 相似文献
13.
本文对形体旋转对称,重心位于对称轴上,并充满粘性均匀液体的对称陀螺在光滑水平面上的运动,给出其定态转动(特别着重斜转态)在各种参数条件下的数目,取向角及Румянцев-Movchan意义下的稳定性。将角动量竖直分量的平方M~2取为控制参数,对定态转动得到三种分叉类型和相应的突变方式。考虑到不可避免地存在微弱摩擦力矩会导致M~2的极缓慢衰减,本文根据分叉突变分析,避开了繁琐的动力学论证,对于初始处于零章动角的稳定准竖立正转定态的陀螺,证明只存在两种不同的倾倒方式。这是突变理论在充液腔体旋转运动问题上的有理论和实际意义的应用。此外,得到的q_4支对陀螺的稳定性控制具有实际意义。 相似文献
14.
We show that every finite volume hyperbolic manifold of dimension greater than or equal to 3 is stable under rescaled Ricci flow, i.e. that every small perturbation of the hyperbolic metric flows back to the hyperbolic metric again. Note that we do not need to make any decay assumptions on this perturbation. 相似文献
15.
This paper is concerned with nonlinear issues in economic development. We suggest a model of dynamic interdependence of economic development, openness and human capital accumulation. The model provides some insights into complex of modernization of mainland China. We show conditions under which the dynamic system exhibits multiple equilibria, limit cycles or catastrophes. 相似文献
16.
The effect of the type of springs on the equilibrium states of an inverted pendulum is examined. The angular and linear eccentricities
of the follower force are taken into account
__________
Translated from Prikladnaya Mekhanika, Vol. 43, No. 6, pp. 126–137, June 2007. 相似文献
17.
The cavitated bifurcation problem in a solid sphere composed of two compressible hyper-elastic materials is examined. The
bifurcation solution for the composed sphere under a uniform radial tensile boundary dead-load is obtained. The bifurcation
curves and the stress contributions subsequent to the cavitation are given. The right and left bifurcation as well as the
catastrophe and concentration of stresses are analyzed. The stability of solutions is discussed through an energy comparison.
Project supported by the National Natural Science Foundation of China (No. 19802012). 相似文献
18.
弹性圆柱壳冲击扭转屈曲的突变模型 总被引:2,自引:0,他引:2
本文将突变理论用于处理冲击载荷下弹性结构的屈曲问题,文中建立了结构冲击屈曲的突变准则,认为临界阶跃载荷位于所提出突变系统的分叉集之中,并由此对两端固支的弹性圆柱壳扭转屈曲进行了分析,给出了不同初缺陷时的临界阶跃扭矩计算公式,通过对临界静态扭矩的计算,表明临界阶跃扭矩小于临界静态扭矩. 相似文献
19.
Motivated by optimization problems in structural engineering, we study the critical points of symmetric, ‘reflected', one-parameter
family of potentials U(p, x) = max (f(p,x), f(p, −x)), yielding modest generalizations of classical bifurcations, predicted by elementary catastrophe theory. One such generalization
is the ‘five-branch pitchfork’, where the symmetric optimum persists beyond the critical parameter value. Our theory may help
to explain why symmetrical structures are often optimal. 相似文献
20.
基于尖点突变的性质,对修改后的Logistic模型进行变换,并将其化为具有尖点突变的标准模型.利用微分方程定性理论,对模型进行分析,并根据突变理论,给出突变发生的条件.最后利用仿真验证结论的正确性. 相似文献