Color Enhancement in Multispectral Image Using the Karhunen-Loeve Transform

We propose a new method for the color enhancement of multispectral image in the visible wavelength region. The purpose of the proposed method is to explore the weak features contained in a specific wavelength by discounting the major color distribution. Such examination will be valuable in visual inspection applications, for example, a medical examination using color image to find a small spectral change of an abnormal part. In this method, Karhunen-Loeve (KL) transform is applied to multispectral data, and specific wavelength components of only high-order KL coefficients are amplified while low-order coefficients are not changed to retain the major color distribution. In the experiment, this method was applied to multispectral images: a printed test image and a human skin image of a bruised arm were captured by a 16-band multispectral camera. The resultant images were compared with the images obtained by saturation enhancement and that obtained by applying the proposed method to the 3-band image. The method successfully visualized the features, which are almost invisible in natural color images, with less change in background color than saturation enhancement.     

Interaction of DNA with hydroxyapatite. Studies on the effect of the phosphate concentration of the column equilibration and washing buffer

The ability of hydroxyapatite to bind DNA effectively in phosphate solutions used for column equilibration, sample loading and column washing has been examined. It was demonstrated that substantial amounts of DNA (up to 40%) were eluted in the washing buffer when the phosphate concentration in the lysing solution or urea-phosphate used for column equilibration, sample loading and column washing was 0.24 M. A reduction in the phosphate concentration from 0.24 to 0.15 M in urea-phosphate solution led to almost 100% binding, whereas a similar reduction in the lysing solution did not. A modified method for loading and eluting DNA from hydroxyapatite columns is presented.     

The fluorescence lifetimes of the methyl-substituted benzyl,triphenylmethyl and diphenylmethyl radicals

Time resolved fluorescence of some methyl-substituted benzyl, triphenylmethyl, and diphenylmethyl radicals trapped in rigid solvents at low temperature has been observed. These radicals were excited by pulsed N₂ laser at 337 nm. It is found that these radicals exhibit very long fluorescence lifetime. The long lifetimes of these radicals seem to indicate that the first doublet-doublet electronic transitions of the radicals have a forbidden character.     

Detection of Interval Changes from a Pair of Images: A Proposal of Pattern Histogram

A new method to detect interval changes from a pair of images is presented, especially when the precise image registration is not available. We extend a well-known image histogram to multi-dimensions with some modifications and make use of it to elucidate differences between the images. The framework herein introduced is based on a comparison of the images in their multi-dimensional histogram space rather than in a spatial domain. Due to its flexibility, this approach is preferred as an alternative image comparison technique. The performance of the method is confirmed on simulated and real medical images and compared with the results from related conventional counterparts.     

Long-Term Interval Change Detection from a Sequence of Personal Images

Temporal series of personal images may provide us valuable information regarding progression of a disease over time. A new method, which is based on a pattern histogram approach and time series analysis, is presented to detect long-term interval changes. Highly correlated and increasing pattern characteristics are considered as real interval changes, while background and noisy patterns exhibit more chaotic variations over time. The method has been tested on a sequence of chest radiographs using corresponding regions of interest, which include an increasing number of small opacities. The experimental results show that the method is promising and can be used in clinical applications over time. A key aspect of the proposed method is its independence of feature locations; therefore, it does not require any image registration technique to extract feature characteristics of the interval changes.     

Velocity–pressure correlation measurements in complex free shear flows

Simultaneous measurements of fluctuating velocity and pressure were performed in various turbulent free shear flows including a turbulent mixing layer and the wing-tip vortex trailing from a NACA0012 half-wing. Two different methods for fluctuating static pressure measurement were considered: a direct method using a miniature Pitot tube and an indirect method where static pressure was calculated from total pressure. The pressure obtained by either of these methods was correlated with the velocity measured by an X-type hot-wire probe. The results from these two techniques agreed with each other in the turbulent mixing layer. In the wing-tip vortex case, however, some discrepancies were found, although overall characteristics of the pressure-related statistics were adequately captured by both methods.     

Evaluation of Extended Weak-Equilibrium Conditions for Fully Developed Rotating Channel Flow

The weak-equilibrium condition, which is the basis in the development of algebraic Reynolds stress models is assessed in the prediction of fully developed turbulent channel flow under the influence of system rotation. The budget of the various terms of the exact transport equation for the anisotropy tensor is evaluated by using a DNS database. Two diffusive transport constraints are evaluated by using the DNS data. The results show that neither of them can hold for the near-wall region. An asymptotic analysis of the near-wall behavior is performed and an alternative form of the diffusive transport constraint is proposed. The analysis shows that the proposed alternative diffusive transport constraint has the potential to improve the predictive ability of the resultant ARSM.     

The reaction of S(3P) atoms with nitric oxide

The flash photolysis–vacuum ultraviolet kinetic absorption spectroscopy technique has been used to measure the absolute rate constant for the reaction of ground state S(³P) atoms withnitric oxide,\documentclass{article}\pagestyle{empty}\begin{document}${\rm S}\left({^{\rm 3} P} \right) + {\rm NO}\mathop {\longrightarrow}\limits^{\rm M} {\rm SNO}\left({{\rm M} = {\rm CO}_2} \right)$\end{document} as a function of nitric oxide concentration and total pressure. The rateconstant was determined to be 1.9±0.1 × 10¹¹ 1²/mol².sec at 298°K, with a high-pressure limit of 9.3 ± 2.1×10⁹ l/mol·sec^?1. The observed kinetics are consistent with a termolecular energy transfer mechanism.