A self-dual harmonic 2–form on a 4–dimensional Riemannian manifold is symplectic where it does not vanish. Furthermore, away from the form’s zero set, the metric and the 2–form give a compatible almost complex structure and thus pseudo-holomorphic subvarieties. Such a subvariety is said to have finite energy when the integral over the variety of the given self-dual 2–form is finite. This articl...

A self-dual harmonic 2{form on a 4{dimensional Riemannian manifold is symplectic where it does not vanish. Furthermore, away from the form’s zero set, the metric and the 2{form give a compatible almost complex structure and thus pseudo-holomorphic subvarieties. Such a subvariety is said to have nite energy when the integral over the variety of the given self-dual 2{form is nite. This article pr...

To blend be~ween simple implicit surfaces, such as the sphere, the cone, the cylinder and the torus, we propose La locally employ the zero set of a serendipitous trivariate box spline. This box spline is defined by seven directions that form a regular partition of space into tetrahedra. The resulting blend surface is curvature continuous. An approxlmateparametrization of the piecewise implicit ...

We study the strongly singular volume integral operator that describes the scattering of time-harmonic electromagnetic waves. For the case of piecewise constant material coefficients and smooth interfaces, we determine the essential spectrum. We show that it is a finite set and that the operator is Fredholm of index zero in H(curl) if and only if the relative permeability and permittivity are b...

Resonance tongues are mode-locking regions of parameter space in which stable periodic solutions occur; they commonly occur, for example, near Neimark-Sacker bifurcations. For piecewise-smooth, continuous maps these tongues typically have a distinctive lens-chain (or sausage) shape in two-parameter bifurcation diagrams. We give a symbolic description of a class of “rotational” periodic solution...

We provide lower bounds for the maximum number of limit cycles for the m–piecewise discontinuous polynomial differential equations ẋ = y + sgn(gm(x, y))F (x), ẏ = −x, where the zero set of the function sgn(gm(x, y)) with m = 2, 4, 6, . . . is the product of m/2 straight lines passing through the origin of coordinates dividing the plane in sectors of angle 2π/m, and sgn(z) denotes the sign funct...

abstract. let $l$ be a lattice with the least element $0$. an element $xin l$ is a zero divisor if $xwedge y=0$ for some $yin l^*=lsetminus left{0right}$. the set of all zero divisors is denoted by $z(l)$. we associate a simple graph $gamma(l)$ to $l$ with vertex set $z(l)^*=z(l)setminus left{0right}$, the set of non-zero zero divisors of $l$ and distinct $x,yin z(l)^*$ are adjacent if and only...

Syndesis n. (pl. ~ es). [mod, L, f. Gk SYNdesis} binding together (sundeo bind together)]. —The Concise Oxford Dictionary, Seventh Edition, 1986. User and system models are typically viewed as independent representations that provide complementary insights into aspects of human-computer interaction. Within system development it is usual to see the two activities as separate, or at best loosely ...

jahanshahloo has suggested a method for the solving linear programming problems with zero-one variables‎. ‎in this paper we formulate fully fuzzy linear programming problems with zero-one variables and a method for solving these problems is presented using the ranking function and also the branch and bound method along with an example is presented.