present work shows the numerical determination of fatigue crack opening and closure stress intensity factors of a C(T) specimen under variable amplitude loading using a finite element method. A half compact tension C(T) specimen, assuming plane stress constraint was used by finite element method covering the effects in two-dimensional (2D) small scale yielding models of fatigue crack growth und...

A polarization-selective holographic optical element with compact dimensions of 2.4mm X 1mm X 1mm (width X length X thickness) is proposed. The element includes three modules: a holographic polarizing beam-splitter, a holographic input coupler, and a dove-prism coupler so that a simple and dense optical pick-up head can be achieved. Polarization properties of holographic volume gratings are bri...

We apply finite element methods to elliptic problems on compact Riemannian manifolds. The elliptic equation on manifolds is reduced to coupled equations on Euclidean spaces by coordinate charts. The advantage of this strategy is to avoid global triangulations on curved manifolds in the finite element method. The resulting finite element problem can be solved globally, or locally by nonoverlappi...

An internal compact printed loop antenna with matching element is presented for laptop applications. Bending to the printed loop structure is employed to reduce the size of antenna. A matching element is used at backside of the substrate to enhance the bandwidth of the antenna. The matching element is of rectangular shape with inverted U shape slot in it. The proposed antenna with wideband char...

We demonstrate high-resolution x-ray differential interference contrast DIC in a compact soft x-ray microscope. Phase contrast imaging is enabled by the use of a diffractive optical element objective which is matched to the coherence conditions in the microscope setup. The performance of the diffractive optical element objective is evaluated in comparison with a normal zone plate by imaging of ...

Unless we say otherwise, every vector space we talk about is taken to be over C. A Banach algebra is a Banach space A that is also an algebra satisfying ‖AB‖ ≤ ‖A‖ ‖B‖ for A,B ∈ A. We say that A is unital if there is a nonzero element I ∈ A such that AI = A and IA = A for all A ∈ A, called a identity element. If X is a Banach space, let B(X) denote the set of bounded linear operators X → X, and...

The ability of a single acoustic element to produce a compact time domain signal from a multi-mode solid cylindrical waveguide using a time-reversal mirror (TRM) is considered. Two single element longitudinal contact transducers were used to excite and receive multiple longitudinal modes in a fused quartz waveguide in a TRM experiment. The TRM is demonstrated to be effective with the limited in...

Measurements of cosmic microwave background (CMB) anisotropy are ideal experiments for discovering the non-trivial global topology of the universe. To evaluate the CMB anisotropy in multiply-connected compact cosmological models, one needs to compute the eigenmodes of the Laplace-Beltrami operator. Using the direct boundary element method, we numerically obtain the low-lying eigenmodes on a com...

In this paper, we give a fourth-order compact finite difference scheme for the general forms of two point boundary value problems and two dimensional elliptic partial differential equations (PDE’s). By decomposing the coefficient matrix into a sum of several matrixes after we discretize the original problem, we can obtain a lower bound for the smallest eigenvalue of the coefficient matrix. Thus...

The F-Onion-tree is a robust access method that slices the metric space into disjoint subspaces to provide quick indexing of complex data in the main memory. However, the F-Onion-tree only performs element-by-element insertions into its structure, i.e. it does not introduce a technique to build the index considering all elements of the dataset at once. In this article, we fill this gap. We prop...