where G(u) is a bounded, nondecreasing function with G(— °o)=0 and where 7 is a real-valued constant. Below it is shown that for certain processes of this type the measure of the Hilbert neighborhood of the origin is related to the solution of a certain differential system. In fact, (A) if {x(t), 0fkt< °° } is a separable stochastic process with symmetric, stationary, and independent increments...

We prove L1{contraction principle and uniqueness of solutions for quasilinear elliptic{parabolic equations of the form @t[b(u)] div[a(ru; b(u))] + f(b(u)) = 0 in (0; T ) ; where b is monotone nondecreasing and continuous. We only assume that u is a weak solution of nite energy (see [1]). In particular, we do not suppose that the distributional derivative @t[b(u)] is a bounded Borel measure or a...

In this paper we address a general Goal Programming problem with linear objectives, convex constraints, and an arbitrary componentwise nondecreasing norm to aggregate deviations with respect to targets. In particular, classical Linear Goal Programming problems, as well as several models in Location and Regression Analysis are modeled within this framework. In spite of its generality, this probl...

We study here the discretisation of the nonlinear hyperbolic equation ut + div(vf(u)) = 0 in IR 2 IR+, with given initial condition u(:; 0) = u0(:) in IR 2 , where v is a function from IR 2 IR+ to IR 2 such that divv = 0 and f is a given nondecreasing function from IR to IR. An explicit Euler scheme is used for the time discretisation of the equation, and a triangular mesh for the spatial discr...

Let h : [0,∞) 7→ [0,∞) be continuous and nondecreasing, h(t) > 0 if t > 0, and m,q be positive real numbers. We investigate the behavior when k → ∞ of the fundamental solutions u = uk of ∂tu − ∆u m + h(t)u = 0 in Ω × (0, T ) satisfying uk(x, 0) = kδ0. The main question is wether the limit is still a solution of the above equation with an isolated singularity at (0, 0), or a solution of the asso...

Let h : [0,∞) 7→ [0,∞) be continuous and nondecreasing, h(t) > 0 if t > 0, and m,q be positive real numbers. We investigate the behavior when k → ∞ of the fundamental solutions u = uk of ∂tu − ∆u m + h(t)u = 0 in Ω × (0, T ) satisfying uk(x, 0) = kδ0. The main question is wether the limit is still a solution of the above equation with an isolated singularity at (0, 0), or a solution of the asso...

One of the major tools introduced by Perelman is his reduced volume ̃ V [21, Sect. 7]. This is a certain geometric quantity which is monotonically nondecreasing in time when one has a Ricci flow solution. Perelman’s main use of the reduced volume was to rule out local collapsing in a Ricci flow. Before giving his rigorous proof that ̃ V is monotonic, Perelman gave a heuristic argument [21, Sect. ...

In the spotlight of this study is a particular type of first order dynamic initial value problem of the form u = f(t, u) + g(t, u), u(t0) = u0, where f, g ∈ Crd [T × R,R] are nondecreasing and nonincreasing in u, respectively. A quasilinearization technique utilizing the nature of natural lower and upper solutions as well as coupled lower and upper solutions is developed for this problem. Begin...