Minimum spanning tree-based random-valued impulse noise detection for a switching median filter

A switching median filter is effective for impulse noise elimination while preserving edges and details of an image. In the switching median filter an impulse noise detector is employed before filtering, and the detection result is used to control whether a pixel should be filtered or not. However, the conventional impulse detector tends to misjudge noise-free pixels constructing line structures to be the noises. We propose a new random-valued impulse noise detector based on the minimum spanning tree, and it is applied to the switching median filtering to eliminate the impulse noise effectively even for the image including line structures. Through the experiments, the effectiveness of the proposed random-valued impulse noise detector is illustrated.     

Split-aperture laser pulse compressor design tolerant to alignment and line-density differences

We introduce a four-pass laser pulse compressor design based on two grating apertures with two gratings per aperture that is tolerant to some alignment errors and, importantly, to grating-to-grating period variations. Each half-beam samples each grating in a diamond-shaped compressor that is symmetric about a central bisecting plane. For any given grating, the two half-beams impinge on opposite sides of its surface normal. It is shown that the two split beams have no pointing difference from paired gratings with different periods. Furthermore, no phase shift between half-beams is incurred as long as the planes containing a grating line and the surface normal for each grating of the pair are parallel. For grating pairs satisfying this condition, gratings surfaces need not be on the same plane, as changes in the gap between the two can compensate to bring the beams back in phase.     

Photo-conversion and evolution of one-dimensional Cu nanoparticles under femtosecond laser irradiation

Metal nanowires with electric conductive properties can be useful for optical polarization control medium and electro-conductive nanomaterial. We report on metallic Cu nanowires with a length of 1.0 μm and a diameter of 85 nm which were successfully photo-converted from commercial scale-like Cu particles, dispersed in a methanol solution, by using femtosecond laser irradiation. The growth mechanism of Cu nanowires under laser irradiation was suggested to be a nucleation growth process.     

A novel analysis method for noise of perpendicular recording media

An in-field magnetic force microscopy (MFM) observation technology was introduced to study media noise in perpendicular recording medium. Magnetization reversal field (H_R) distribution of the recording medium could be mapped by this technology. We have extracted media noise signal image from recording pattern. The noise signal image was converted to a contour image, in which peak areas represented high-noise areas. To clarify the relationship between H_R distribution and the media noise, we novelly combined the contour with the H_R-map. The results show that the media noise mostly gets generated in the lower-H_R areas, which indicates the lower-H_R area is one of the important origins of the media noise. For comparison, a simulation work was also performed by introducing a model based on experimental parameters. The simulation agreed with experimental results very well.     

Spectrophotometric determination of micro amounts of thiosulfate by liberation of thiocyanate from mercury(II) thiocyanate

The proposed determination of thiosulfate is based on the liberation of thiocyanate by the reaction of thiosulfate with mercury(II) thiocyanate and spectrophotometric determination of the thiocyanate with iron(III). The reaction of thiosulfate with mercury(II) thiocyanate is elucidated with reference to a system containing phosphate buffer; the phosphate is shown to participate directly in the reaction, and a balanced chemical equation is given. Optimum conditions are described for the stoichiometric formation of 3 mol of thiocyanate from 1 mol of thiosulfate. The method can be applied to the determination of thiosulfate in the range 3 × 10^?6–1.4 × 10^?4 M (1.7–78.5 μg thiosulfate in 5 ml).     

Two-loop double-pole counter lagrangian

On the basis of the background field method, extended one-loop counterterm formulae are derived, and a method to get the two-loop double-pole counter lagrangian is given. As an example, the double-pole divergences of ξ²X³ counterterms are obtained.     

Stable mode-locking operation in a Cr:forsterite laser with a five-mirror cavity

The experimental finding of more-stable mode-locking operation in a five-mirror cavity than in a conventional four-mirror cavity for a Cr:forsterite laser [IEEE J. Quantum Electron. 33, 1975 (1997)] was interpreted by ABCD-matrix formalism. Since the optimum cavity configuration operation for mode-locking operation was attainable in the middle of the stable cavity condition, we conclude that one can easily achieve KLM alignment and stable mode locking with a five-mirror cavity.