5,999 research outputs found

    Mixed Variational Formulation for the Wellposedness and Numerical Approximation of a PDE Model Arising in a 3-D Fluid-Structure Interaction

    Get PDF
    We present qualitative and numerical results on a partial differential equation (PDE) system which models a certain fluid-structure dynamics. Wellposedness is established by constructing for it a nonstandard semigroup generator representation; this representation is accomplished by an appropriate elimination of the pressure. This coupled PDE model involves the Stokes system which evolves on a three dimensional domain O coupled to a fourth order plate equation, possibly with rotational inertia parameter ρ\u3e0. This plate PDE evolves on a flat portion Ω of the boundary of O. The coupling on Ω is implemented via the Dirichlet trace of the Stokes system fluid variable - and so the no-slip condition is necessarily not in play - and via the Dirichlet boundary trace of the pressure, which essentially acts as a forcing term on Ω. We note that as the Stokes fluid velocity does not vanish on Ω, the pressure variable cannot be eliminated by the classic Leray projector; instead, it is identified as the solution of an elliptic boundary value problem. Eventually, wellposedness of the system is attained through a nonstandard variational (``inf-sup ) formulation. Subsequently we show how our constructive proof of wellposedness naturally gives rise to a mixed finite element method for numerically approximating solutions of this fluid-structure dynamics

    Pseudorabies in Cattle

    Get PDF
    Pseudorabies (PR), or Aujeszky\u27s Disease is a disease caused by a Herpesvirus causing both apparent and inapparent infections in swine and causing disease in other species

    Evaluation of the Air Force’s Determination of the Military Value of the W.K. Kellogg Air Guard Station and the Potential Cost Savings Generated by its Closing

    Get PDF
    This is an evaluation of the methodology used by the Air Force in determining the military value of the W.K. Kellogg Air Guard Station and in estimating the potential costs savings generated by its proposed closing

    A 2D Parallel Triangle Counting Algorithm for Distributed-Memory Architectures

    Full text link
    Triangle counting is a fundamental graph analytic operation that is used extensively in network science and graph mining. As the size of the graphs that needs to be analyzed continues to grow, there is a requirement in developing scalable algorithms for distributed-memory parallel systems. To this end, we present a distributed-memory triangle counting algorithm, which uses a 2D cyclic decomposition to balance the computations and reduce the communication overheads. The algorithm structures its communication and computational steps such that it reduces its memory overhead and includes key optimizations that leverage the sparsity of the graph and the way the computations are structured. Experiments on synthetic and real-world graphs show that our algorithm obtains an average relative speedup that range between 3.24 and 7.22 out of 10.56 across the datasets using 169 MPI ranks over the performance achieved by 16 MPI ranks. Moreover, we obtain an average speedup of 10.2 times on comparison with previously developed distributed-memory parallel algorithms.Comment: 10 pages, 3 figures, 48th International Conference on Parallel Processin

    What Is Important In Reading In Middle Level Classrooms: A Survey of Classroom Teachers\u27 Perceptions

    Get PDF
    Should reading instruction in middle level schools be aimed at helping youngsters to acquire more specific, isolated skills of how to read? Or should the focus of reading in middle level schools be on assisting learners to become readers? An answer to both of these critical questions might be — yes. Middle level learners (10 to 14 years old) should grow both in their skillfulness as readers and in the process of becoming readers. Research data and current instructional practices can be found to support both of these positions
    corecore