We consider binary pairwise graphical models and provide an exact characterization (necessary and sufficient conditions observing signs of potentials) of tightness for the LP relaxation on the triplet-consistent polytope of the MAP inference problem, by forbidding an odd-K5 (complete graph on 5 variables with all edges repulsive) as a signed minor in the signed suspension graph. This captures s...

This publication reports the derivation and the implementation of a simulation model that describes non-resonant photoacoustic gas sensors. The photoacoustic effect is modelled in detail for the successive steps of radiation emission, stimulation of molecules, collisional relaxation processes and finally the pressure formation in a closed gas cell. The photoacoustic effect offers great potentia...

The SOR iteration for solving linear systems of equations depends upon an overrelaxation factor co. We show that, for the standard model problem of Poisson's equation on a rectangle, the optimal co and corresponding convergence rate can be obtained rigorously by Fourier analysis. The trick is to tilt the space-time grid so that the SOR stencil becomes symmetrical. The tilted grid also gives new...

We consider convex approximations of the expected value function of a two-stage integer recourse problem. The convex approximations are obtained by perturbing the distribution of the random right-hand side vector. It is shown that the approximation is optimal for the class of problems with totally unimodular recourse matrices. For problems not in this class, the result is a convex lower bound t...

A lateral boundary treatment using summation-by-parts operators and simultaneous approximation terms is introduced. The method, that we refer to as the multiple penalty technique, is similar to Davies relaxation and have similar areas of application. The method is proven, by energy methods, to be stable. We show how to apply this technique on the linearized Euler equations in two space dimensio...

We report molecular dynamics simulation results for the single particle and collective orientational correlations for Gay–Berne fluid of anisotropy parameters k53 and k855. The following significant results are reported. ~i! The decay of collective orientational relaxation of rank two is found to slow down appreciably while approaching the isotropic–nematic ~I–N! transition. It eventually becom...

Internal friction peaks measured as a function of temperature or frequency have been associated to non-linear processes only after studying how the amplitude of the applied stress affects the relaxation process. Here it is demonstrated that the partial derivative of the internal bidion with respect to the frequency at constant temperature is a useful tool to determine that non-linear effects ar...

Successive Over-Relaxation (SOR) is a method used extensively for solving partial diierential equations by nite diierence. Compared with the Jacobi method for the same class of problems, SOR (of which the Gauss-Seidel method is a special case) ooers faster convergence. All of the schemes of parallelizing SOR proposed require two-way communication between neighbor processors. The number of the m...

We study the unweighted Tree Augmentation Problem (TAP) via the Lasserre (Sum of Squares) system. We prove an approximation guarantee of (1.8 + ) relative to an SDP relaxation, which matches the combinatorial approximation guarantee of Even, Feldman, Kortsarz and Nutov in ACM TALG (2009), where > 0 is a constant. We generalize the combinatorial analysis of integral solutions of Even, et al., to...

We study an equivalent optimization problem with an inequality constraint and boundary conditions, whose necessary condition for the optimality is the variational inequality presentation of American options. To solve the problem, we use the gradient projection method, with discretizations both in time and space. We tested the algorithm and compared with the projective successive over-relaxation...