An element a of a semigroup algebra F[S] over a field F is called a right annihilating element of F[S] if xa = 0 for every x ∈ F[S], where 0 denotes the zero of F[S]. The set of all right annihilating elements of F[S] is called the right annihilator of F[S]. In this paper we show that, for an arbitrary field F, if a finite semigroup S is a direct product or semilattice or right zero semigroup o...

A finite element-finite difference numerical model is developed for predicting non-uniform temperature development in hydrating concrete with respect to time and space. The results obtained from this model can be used by structural and construction engineers to predict critical thermal stresses induced due to differential temperatures between the core and the surface of the concrete at early ag...

Electrical capacitance tomography (ECT) is a non-invasive imaging technique that aims at visualization the permittivity distribution of dielectric materials based on the measured capacitances. In this paper, the 3D finite element models of a direct 3D ECT sensor with or without dielectric spheres inside the sensor are set up by using finite element modeling. The sensitivity analysis of the sens...

The Reissner-Mindlin model is frequently used by engineers for plates and shells of small to moderate thickness. This model is well known for its “locking” phenomenon so that many numerical approximations behave poorly when the thickness parameter tends to zero. Following the formulation derived by Brezzi and Fortin, we construct a new finite element scheme for the Reissner-Mindlin model using ...

where g±d 6= 0. The positive integer d is called the depth of this Z-grading, and of the nilpotent element e. This notion was previously studied e.g. in [P1]. An element of g of the form e+ F , where F is a non-zero element of g−d, is called a cyclic element, associated with e. In [K1] Kostant proved that any cyclic element, associated with a principal (= regular) nilpotent element e, is regula...

Even if a mesh is valid and all of the elements are approximately the same size, the quality, as measured by parameters such as aspect ratio, skew, and Jacobian quality metrics, may be poor. Theoretically, the FE solution should approach the exact solution as the size of the largest element approaches zero. It has been demonstrated, however, that if dihedral angles approach π as the element siz...

We analyze the complexity of verifying whether a given element is within " of the solution element. This may be contrasted with the complexity of computing an element that is within " of the solution element. For discrete problems with " = 0 veriication is no harder than computation in any setting. For IBC problems veriication can be easier or harder than computation. We will show that the wors...

In their monograph Direct decompositions of finite algebraic systems, Jónsson and Tarski have established the unique factorization theorem and several related results for a comprehensive class of finite abstract algebras. Every algebra SÏ of this class is constituted by a set A of arbitrary elements, by a binary operation + , and possibly by other operations 00, Oi, • • • ; the only conditions ...

High transportation demand has led to widening of existing roadways to improve traffic flow. In some cases, the space available on site is limited and the construction of earth retaining walls is done in front of previously stabilized walls. This can lead to retaining wall designs that are narrower than those addressed in current design guidelines. Narrow walls are Mechanically Stabilized Earth...