We report a study that investigated the neuroanatomical correlates of executive functions in dual-task performance with functional magnetic resonance imaging. Participants performed an auditory and a visual three-choice reaction task either separately as single tasks or concurrently as dual tasks. In the dual-task condition, two stimuli were presented in rapid succession to ensure interference ...

Mikhail A. Bragin • Peter B. Luh • Joseph H. Yan • Nanpeng Yu • Gary A. Stern Communicated by Fabián Flores-Bazàn Abstract Studies have shown that the surrogate subgradient method, to optimize non-smooth dual functions within the Lagrangian relaxation framework, can lead to significant computational improvements as compared to the subgradient method. The key idea is to obtain surrogate subgradi...

After a short introduction of a new nonconforming linear finite element on quadrilaterals recently developed by Park, we derive a dual weighted residual-based a posteriori error estimator (in the sense of Becker and Rannacher) for this finite element. By computing a corresponding dual solution we estimate the error with respect to a given target error functional. The reliability and efficiency ...

We studied selection by predators for cryptic prey coloration in a visually heterogeneous habitat that consists of two microhabitats. It has been suggested that the probability of escaping detection in such habitats might be optimized by maximizing crypsis in one of the microhabitats. However, a recent model indicates that a coloration that compromises the requirements of different microhabitat...

We analyze a posteriori error estimators for finite element discretizations of convec-tion-dominated stationary convection-diffusion equations using locally refined, isotropic meshes. The estimators are based on either the evaluation of local residuals or the solution of discrete local problems with Dirichlet or Neumann boundary conditions. All estimators yield global upper and lower bounds for...

Perturbiner, that is, the solution of field equations which is a generating function for tree form-factors in N = 3 (N = 4) supersymmetric Yang-Mills theory, is studied in the framework of twistor formulation of the N = 3 superfield equations. In the case, when all one-particle asymptotic states belong to the same N = 3 supermul-tiplet (without any restriction on kinematics), the solution is de...

The fuzzy primal simplex method [15] and the fuzzy dual simplex method [17] have been proposed to solve a kind of fuzzy linear programming (FLP) problems involving symmetric trapezoidal fuzzy numbers. The fuzzy simplex method starts with a primal fuzzy basic feasible solution (FBFS) for FLP problem and moves to an optimal basis by walking truth sequence of exception of the optimal basis obtaine...

We study in this paper a posteriori error estimates for H-conforming numerical approximations of diffusion problems with a diffusion coefficient piecewise constant on the mesh cells but arbitrarily discontinuous across the interfaces between the cells. Our estimates give a global upper bound on the error measured either as the energy norm of the difference between the exact and approximate solu...