Industry News--China Xiansu Wire Mesh Co., Ltd.

Mesh deformation based on radial basis function interpolation

A new mesh movement algorithm for unstructured grids is developed which is based on interpolating displacements of the boundary nodes to the whole mesh with radial basis functions (RBF’s). A small system of equations, only involving the boundary nodes, has to be solved and no grid-connectivity information is needed. The method can handle large mesh deformations caused by translations, rotations and deformations, both for 2D and 3D meshes. However, the performance depends on the used RBF. The best accuracy and robustness with the highest efficiency are obtained with a C2 continuous RBF with compact support, closely followed by the thin plate spline. The deformed meshes are suitable for flow computations as is shown by performing calculations around a NACA-0012 airfoil.

In this paper, we present a novel simple method, based on an implementation of space mapping technique, for improvement of the quality of tetrahedral and hexahedral meshes. The same approach is used for surface meshes where geometry of the initial surface mesh is preserved by a local mesh improvement such that new positions of the interior nodes of the mesh remain on the original discrete surface. The proposed method can be used in the pre-processing stage for subsequent studies (finite element analysis, computer graphics, etc.) by providing better input parameters for these processes. Experimental results are included to demonstrate the functionality of our method.
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Extension of a Mesh Quality Metric for Elements With a Curved Boundary Edge or Surface

The formulation of a local cell quality metric [Branets, L., and Carey, G. F., 2003, Proceedings of the 12th International Meshing Roundtable, Santa Fe, NM, pp. 371–378; Engineering with Computers (in press)] for standard elements defined by affine maps is extended here to the case of elements with quadratically curved boundaries. We show for two-dimensional and three-dimensional simplex elements with quadratically curved boundaries that all cases of map degeneracy can be identified by the metric. Moreover, we establish a "maximum principle" which allows estimating the bounds on the quality metric. The nondegeneracy conditions for biquadratic quadrilaterals with one curved edge are also determined. The metric is implemented in an untangling/smoothing algorithm for improving unstructured meshes including simplex elements that have curved boundary segments. The behavior and efficiency of this algorithm is illustrated for numerical test problems in two and three dimensions.
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Coaxial Assembly: Automation is the Key to Quality

Coaxial cable is used in a variety of products serving many different markets. It is used to carry higher frequency signals from point A to point B with minimal signal loss and degradation. Cables and interconnect systems are getting smaller, and overall volume is increasing. The most common applications include antenna cabling, cable TV equipment interconnects and automotive applications. In automobiles, for example, more and more systems (satellite radio, AM/FM radio, GPS, cell phones, etc.) are being packed into extremely tight spaces. This increased density of signal carrying cables makes coaxial cable an obvious choice to reduce or eliminate signal interference.

Cable Preparation
The first step in producing a coaxial cable assembly is to measure and cut the cable to length. Many cables are in the 3 to 12 feet length range and can be produced using an automatic cutting machine and then laid into an automatic stacker. Longer lengths must be coiled and tied for easy handling. A semi-automatic cutting machine (with an optional coiler) can make quick work of this step. The next step is to strip the cable ends to prepare them for termination. This step is best done using a semi-automatic programmable coaxial cable stripper (see photo below). These types of strippers can store parameters for a wide range of cable types and can typically perform a 2 or 3 level strip in approximately 6 seconds. An operator must feed each cable end into the machine and wait until the stripping operation is completed. Fully automatic cable preparation machines are available which eliminate the need for an operator to present each cable end. These machines can measure, cut and strip cables with a cycle time of approximately10 seconds, depending on cable length.
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Free trade deal will mesh FCC, IDA testing

SINGAPORE--Buyers of mobile phones and wireless LAN gear may soon find a greater range of products in the shops, thanks to the landmark Free Trade Agreement (FTA) just signed between the U.S. and the island republic. The bodies that approve radio gear in the U.S. and Singapore will recognize each other's stamp of approval as being good enough for their own countries, as well as mesh their testing procedures.

Both parties will have to try to become more like each other-- the newly-signed deal stipulates that the FCC will incorporate Singapore tests into their own, and vice versa, she added. "The FCC will test the equipment in the U.S., but to Singapore standards. Once that is done it won't need to be tested a second time in Singapore. Singapore will do the same for them," she explained. Industry observers say buyers in a small market like Singapore will benefit. Many brands and models don't appear on shop shelves in the Republic because the small market does not justify the trouble of sending them for type approval. With this roadblock removed, vendors will be more willing to sell a wider range of models and brands, as the larger size of the American market makes the type approval procedure worthwhile. However, major technical differences between the U.S. and Singapore markets will remain despite the agreements. The majority of handsets there use the CDMA cellular standard, while in Singapore and many parts of Asia, the GSM standard is the norm. Also, both countries differ in radio spectrum regulation.