We present a stabilized finite element method for Stokes equations with piecewise continuous bilinear approximations for both velocity and pressure variables. The velocity field is enriched with piecewise polynomial bubble functions with null average at element edges. These functions are statically condensed at the element level and therefore they can be viewed as a continuous Q1–Q1 stabilized ...

In this paper we present a path-following (homotopy) method for (locally) solving bilinear matrix inequality (BMI) problems in control. The method is to linearize the BMI using a first order perturbation approximation, and then iteratively compute a perturbation that “slightly” improves the controller performance by solving a semidefinite program (SDP). This process is repeated until the desire...

In this paper, hydroforming process of bent tubes in T-shaped die is studied for pulsating and linear pressure paths by the finite element method. Forming Limit Diagrams (FLDs) and thickness distribution curves are used to investigate the effect of pulsating pressure on hydroforming process. In addition, the obtained numerical results are compared with experimental results of hydroforming of st...

We consider saddle-point problems that typically arise from the mixed finite element discretization of second order elliptic problems. By proper equivalent algebraic operations the considered saddle-point problem is transformed to another saddle-point problem. The resulting problem can then be efficiently preconditioned by a block-diagonal matrix or by a factored block-matrix (the blocks corres...

Our method approximates exact texture filtering for arbitrary scales and translations of an image while taking into account the performance characteristics of modern GPUs. Our algorithm is fast because it accesses textures with a high degree of spatial locality. Using bilinear samples guarantees that the texels we read are in a regular pattern and that we use a hardware accelerated path. We con...

fiber metal laminates (fmls) are new composite materials consisting of thin metal layers and high strength composite layers. arall (aramid aluminum laminate) is a family of the fml that consists of thin aluminum sheets along with kevlar/epoxy composite layers. this material has many advantages such as light weight, excellent corrosion, fatigue and impact resistance. since, arall is a new materi...

Finite element formulations based on stabilized bilinear and linear equal-order-interpolation velocity-pressure elements are presented for computation of steady and unsteady incompressible flows. The stabilization procedure involves a slightly modified Galerkin/least-squares formulation of the steady-state equations. The pressure field is interpolated by continuous functions for both the quadri...

In this paper, a new stable nonconforming mixed finite element scheme is proposed for the stationary conduction-convection problem, in which a new low order Crouzeix-Raviart type nonconforming rectangular element is taken as approximation space for the velocity, the piecewise constant element for the pressure and the bilinear element for the temperature, respectively. The convergence analysis i...

We introduce a kind of bilinear differential equations by generalizing Hirota bilinear operators, and explore when the linear superposition principle can apply to the resulting generalized bilinear differential equations. Together with an algorithm using weights, two examples of generalized bilinear differential equations are computed to shed light on the presented general scheme for constructi...

The paper deals with the realization theory of linear and bilinear hybrid systems, i.e. hybrid systems with continuous dynamics determined by linear ( respectively bilinear ) control systems. We will formulate necessary and sufficient conditions for the existence of a linear (bilinear ) hybrid system realizing the specified input/output maps. We will also present a characterization of a minimal...