The acoustic characteristics of acoustic tubes with protrusions at the radiation end are computed by FEM simulation. In the rst experiment, two di erent shapes of the protrusions, a symmetrical and an asymmetrical shape with respect to the vertical, are investigated. Frequency characteristics of the radiation impedance are computed from simulation results. The simulation results show that the r...

Numerical theory provides the basis for quantification of the accuracy and reliability of a FEM solution by error estimates on the FEM error vs. the mesh spacing of the FEM mesh. This paper presents techniques needed in COMSOL 5.1 to perform computational studies for elliptic test problems in two and three space dimensions that demonstrate this theory by computing the convergence order of the F...

The fast development of computer power and computational algorithms has made it possible to design complex transducers and arrays using computer simulation. Practical examples are given here for transducer modeling using 3-D finite element method (FEM) instead of the traditional 1-D equivalent circuit models. The merits and deficiencies of the frequency domain and time domain FEM formulations w...

Male sexual development in the nematode Caenorhabditis elegans requires the genes fem-1, fem-2, and fem-3. The current model of sex determination portrays the FEM proteins as components of a novel signal transduction pathway, but the mechanisms involved in signaling through the pathway are not understood. We report the isolation of fem-2 cDNAs in a yeast two-hybrid screen for clones encoding pr...

This paper presents a set of analytical and numerical results on the use of guided waves for structural health monitoring application. The aim of the work presented in this paper is to provide tools to extend modeling capacities and improve quality and reliability of guided wave propagation models using commercially available finite element (FE) packages. Predictive simulation of ultrasonic non...

The tra-2 gene of the nematode Caenorhabditis elegans encodes a predicted membrane protein, TRA-2A, that promotes XX hermaphrodite development. Genetic analysis suggests that tra-2 is a negative regulator of three genes that are required for male development: fem-1, fem-2, and fem-3. We report that the carboxy-terminal region of TRA-2A interacts specifically with FEM-3 in the yeast two-hybrid s...

This study presents a steel container crane movement analysis and assessment based on structural health monitoring (SHM). The accelerometers are used to monitor the dynamic crane behavior and a 3-D finite element model (FEM) was designed to express the static displacement of the crane under the different load cases. The multi-input single-output nonlinear autoregressive neural network with exte...