the hot compression tests were carried on x45crniw189 valve steel (x45) in the temperature rangeof 1000– 1200 °c and the strain rate range of 0.004 – 0.5 s-1 in order to study the high temperaturesoftening behavior of this steel. for the exact prediction of flow stress, the effective stress-effectivestrain curves were obtained from experiments under various conditions. on the basis of experimen...

A 2.45 GHz pulse compression, channel impulse response (CIR) system is described. The motivation for its development and results verifying its performance are given. The system is shown to be an effective test and measurement tool for analysis of 2.4 GHz ISM band channels particularly for spread spectrum communication system deployment. The required signal processing is described and, because o...

The Burrows–Wheeler transform is a powerful tool for data compression and has been the focus of intense research in the last decade. Little attention, however, has been paid to the inverse transform, even though it is a bottleneck in decompression. We introduce three new inversion algorithms with improved performance in a wide range of the space-time spectrum, as confirmed by both theoretical a...

A new effect appears in femtosecond optical pulse compression, using single-mode fibers, that we describe as optical wave breaking. In the fiber, frequency-shifted light in the leading and trailing edges of a pulse overtakes unshifted light in the pulse tails. Mixing of these overlapping frequency components generates sidelobes on the pulse spectrum. The effect often leads to computational inst...

compressibility characteristics of fine-grained soils are often the most important parameters for settlement evaluation of the founded layers. the compression index which is the slope of virgin curve is usually for determination of settlement potential of fine grained soils. in this research, the effects of different physical and index properties of soil samples were investigated on compression...

paulownia is one of the fast-growing species that was attended to supply industrial requirement in recent years. the application of this species is limited because of low density, so wood modification via compression and densification is an effective method. for this purpose, the paulownia boles were prepared from shastkalateh forest and cut into blocks with 60×20×20 mm dimension. the variable ...

Within recent years the use of medical images for diagnosis purposes has become necessity. The limitation in transmission and storage space also growing size of medical images has necessitated the need for efficient method, then image Compression is required as an efficient way to reduces irrelevant and redundancy of the image data in order to be able to store or transmits data. It also reduces...