INTERPOLASI DATA BERDIMENSI d>1 DENGAN FUNGSI BASIS RADIAL (RADIAL BASIS FUNCTION)

Radial Basis Function (RBF) is a method typically used to aproximate a function based on information data. A radial function is a real valued function whose depends only on the distance the data input and some fixed point ,called a centre point. Distance between some fixed point/centre and data input is usually Euclidean metric so that . Commonly types of Radial Basis Function using a to indicate a shape parameter to scale the input data of the radial centre. Since this method has been proven effective and flexsibel so that it has been widely used in engineering and science, so in this paper we will discuss how to use Radial basis Function to interpolate 2 dimension data. From the result of discussion it was found that this method was accurate to aproximate actual data or observation.

Validation of a new 2.5D radiographic index evaluating acetabular coverage using ACX software

Background: Several radiographic signs have been described to assess acetabular coverage. However, plain radiographs only have 2 dimensions (2D) and cannot accurately show acetabular coverage. Questions/purposes: We developed the ACX Dynamics software to calculate the radial centre-edge angle (RCEA), which represents the acetabular coverage of the femoral head at each acetabular edge point on the radial plane. This study validated the accuracy of the RCEA, as calculated by ACX Dynamics, as a quantitative parameter for acetabular coverage. Patients and methods: We reviewed the anteroposterior (AP) pelvic radiographs and computed tomography (CT) of 650 hips from 325 patients who presented with chief complaint of symptoms at the hip joint. Of 109 hip radiographs (68 patients) that satisfied the criteria, 50 randomised, blinded AP pelvic radiographs were chosen. We determined the absolute RCEA difference (°) [= RCEA ACX (°) – RCEA CT (°)], determined the correlation between RCEA ACX (°) and RCEA CT (°), and examined the RCEA’s intra-observer and inter-observer reliability in 50 hips. Results: The absolute RCEA difference from A45° to P75° was 1.9–3.1°. The correlation between the RCEA ACX (°) and RCEA CT (°) was > 0.7 in all lesions ( p < 0.001). Using the intraclass correlation coefficient, the intra-observer reliability of the RCEA was 0.83–0.97 in the whole range, which is a highly reproducible and reasonable parameter, and the inter-observer reliability was > 0.80 in A45°–P0°. Conclusions: The RCEA ACX (°) can be used as a simple quantitative parameter for assessing acetabular coverage using AP pelvic radiograph.

Strength of Cylinders Containing Radial or Offset Cross-Bores

The introduction of a small transverse opening or cross-bore into the wall of a cylindrical pressure vessel is sometimes necessary. Under static conditions such a cross-bore may have little effect on the bursting pressure of a plain cylinder, but under cyclic stress conditions, the fatigue life of the vessel is severely reduced. If the cross-bore axis is offset from the radial centre-line of the cylinder, then the fatigue life of such a vessel is shown to be substantially greater than that of a similar vessel containing a radial cross-bore.