We study a one-phase Stefan problem for a semi-infinite material with temperaturedependent thermal conductivity and a convective term with a constant temperature boundary condition or a heat flux boundary condition of the type −q0/ √ t (q0 > 0) at the fixed face x = 0. We obtain in both cases sufficient conditions for data in order to have a parametric representation of the solution of the simi...

Evaluation methodologies for rare events from meteorology, psychology and medical diagnosis are used to examine the value of probability forecasts of real GDP declines during the current (Q0) and each of the next four quarters (Q1-Q4) using data from the Survey of Professional Forecasters. We study the quality of these probability forecasts in terms of calibration, resolution, odds ratio, the r...

In this paper we consider the one-dimensional compressible Navier–Stokes system linearized about a constant steady state (Q0, 0) with Q0 > 0. We study the controllability and stabilizability of this linearized system. We establish that the linearized system is null controllable for regular initial data by an interior control acting everywhere in the velocity equation. We prove that this result ...

Our goal is to determine for which p is the maximal operator M bounded on L. Note that by subadditivity of maximal operators of the form (1.1), one can prove L boundedness of the nonlocalized analogue of (1.1) over a compact surface by doing a partition of unity and reducing to (1.1). If L is an invertible linear transformation and ML denotes the maximal operator corresponding to the surface L(...

We use the Gu-Huang model for a special case when the universe is seven dimensional. In the core of the extra dimension we place a modified Gidding-Strominger wormhole. This wormhole is separated by a thin wall from the extra dimensional space. The wormhole content is assumed to satisfy the adiabatic gas law. The wormhole pressure penetrates into the extra dimension. We then solve the Einstein ...

Let M be a C∞ Riemannian manifold, dimM = n. A distribution on M is a smooth linear subbundle of the tangent bundle TM . We denote by q the fiber of at q ∈M ; q ⊂ TqM . The number k = dim q is the rank of the distribution. We assume that 1 < k < n. The restriction of the Riemannian structure to is a sub-Riemannian structure. Lipschitz integral curves of the distribution are called admissible pa...

Hydrodynamical simulations of semi-detached, polytropic binary stars are presented in an effort to study the onset and stability of dynamical mass transfer events. Initial, synchronously rotating equilibrium models are constructed using a self-consistentfield technique and then evolved with an Eulerian hydrodynamics code in a fully selfconsistent manner. We describe code improvements introduced...

[1] The frequency dependence of Q in Earth’s upper mantle is investigated using the continuous P wave spectra over 0.08 < f < 8.0 Hz. Regional waveform data from 23 events in the Pacific slab recorded on broadband stations in western Japan were used to create spectral ratio estimates of P waves which sample a subducting slab and mantle wedge. We assumed the power-law model Q( f ) = Q0( f/f0) a ...

Polyampholytes (PAs) are polymers composed of (quenched) random sequences of positive and negatively charged monomeric groups. We show that the radius of gyration, Rg, of a PA strongly depends on its overall excess chargeQ, and is very weakly influenced by other aspects of the sequence. For Q < Qc ≈ q0 √ N , where N is the number of monomers of charge ±q0, the PA is compact, while for Q > Qc it...

200 NOTICES OF THE AMS VOLUME 52, NUMBER 2 Introduction A quiver is just a directed graph.1 Formally, a quiver is a pair Q = (Q0,Q1) where Q0 is a finite set of vertices and Q1 is a finite set of arrows between them. If a ∈ Q1 is an arrow, then ta and ha denote its tail and its head, respectively. Let us fix a quiver Q and a base field K. Attach a finite dimensional vector space to each vertex ...