A stochastic realization algorithm via block LQ decomposition in Hilbert space

A stochastic realization problem of a stationary stochastic process is re-visited, and a new stochastically balanced realization algorithm is derived in a Hilbert space generated by second-order stationary processes. The present algorithm computes a stochastically balanced realization by means of the singular value decomposition of a weighted block Hankel matrix derived by a “block LQ decomposition”. Extension to a stochastic subspace identification method explains how the proposed abstract algorithm is implemented in system identification.     

Transcutaneous measurement and spectrum analysis of heart wallvibrations

For the noninvasive diagnosis of heart disease based on the acoustic and elastic characteristics of the heart muscle, it is necessary to transcutaneously measure small vibration signals, including components with an amplitude of less than 100 μm, from various parts of the heart wall continuously for periods of more than several heartbeats in a wide frequency range up to 1 kHz. Such measurement, however, has not been realized by any ultrasonic diagnostic methods or systems to date. By introducing the constraint least-square approach, this paper proposes a new method for accurately tracking the movement of the heart wall based on both the phase and magnitude of the demodulated signal to determine the instantaneous position of the object so that the vibration velocity of the moving object can be accurately estimated. By this method, small vibrations of the heart wall with small amplitudes less than 100 μm on the motion resulting from a heartbeat with large amplitude of 10 mm can be successfully detected with sufficient reproducibility in the frequency range up to several hundred Hertz continuously for periods of about 10 heartbeats. The resultant small vibration is analyzed not only in the time domain, but also in the frequency domain. As confirmed by the preliminary experiments herein reported, the new method offers potential for research in acoustical diagnosis of heart disease     

Stabilization of bioethanol recovery with silicone rubber‐coated ethanol‐permselective silicalite membranes by controlling the pH of acidic feed solution

In order to produce highly concentrated bioethanol by pervaporation using an ethanol‐permselective silicalite membrane, techniques to suppress adsorption of succinic acid, which is a chief by‐product of ethanol fermentation and causes the deterioration in pervaporation performance, onto the silicalite crystals was investigated. The amount adsorbed increased as the pH of the aqueous succinic acid solution decreased. The pervaporation performance also decreased with decreasing pH when the ternary mixtures of ethanol/water/succinic acid were separated. Using silicalite membranes individually coated with two types of silicone rubber, pervaporation performance was significantly improved in the pH range of 5 to 7, when compared with that of non‐coated silicalite membranes in ternary mixtures of ethanol/water/succinic acid. Moreover, when using a silicalite membrane double‐coated with the two types of silicone rubber, pervaporation performance was stabilized at lower pH values. In the separation of bioethanol by pervaporation using the double‐coated silicalite membrane, removal of accumulated substances having an ultraviolet absorption maximum at approximately 260 nm from the fermentation broth proved to be vital for efficient pervaporation. Copyright © 2005 Society of Chemical Industry     

Analysis of XANES for identification of highly dispersed transition metal oxides on supports

XANES of vanadium and niobium oxide on silica or alumina have been analyzed quantitatively by a deconvolution technique. Based on the results for reference compounds, local structures of supported vanadium and niobium species were identified. The composition was estimated from difference spectra for the samples which consisted of two kinds of species.     

A high resolution negative working resist,LMR-UV,for g- and i-line lithography

LMR-UV (“low molecular weight resist for uv lithography”), a naphthoquinone-diazide sulfonic acid ester of a novolak resin, is a negative working resist. The mechanism of insolubilization of LMR-UV is based on the facts that the naphthoquinone-diazide moiety is decomposed to indenecarboxylic acid (polar compound) by photolysis upon UV irradiation and that the irradiated resist film insolubilizes in a non-polar developer. LMR-UV reliably forms 0.6 μm lines and spaces over a reflective substrate with steps by using a g-line stepper having a 0.35 NA lens. 0.6 μm-wide aluminum patterns over topography are obtained by use of g-line exposure and reactive ion etching. By use of an i-line aligner (NA = 0.42), LMR-UV resolves 0.25 μm space patterns with overhang profiles. The profiles are due to the large absorption coefficient of 3.8 μm^?1. 0.3 μm wide aluminum patterns are formed by i-line exposure and lift-off metallization.     

Rates for intramolecular excimer formation of poly(α-methylstyrene) measured by using picosecond pulse radiolysis

Summary The rate constants for intramolecular excimer formation, k_DM, of poly(α-methylstyrene) with different molecular weight were determined by using picosecond pulse radiolysis. Values of k_DM for poly(α-methylstyrene) are a little smaller than those for polystyrene with nearly same molecular weight. It appears to be mainly due to steric hindrance by methyl substituent of main chain.     

High-frequency ultrasonic cleaning tank utilizing oblique incidence

Transmission characteristics of a double-structured tank, used for high-frequency (1 MHz range) ultrasonic cleaning of semiconductor wafers and substrates, were improved by utilizing oblique incidence of ultrasonic waves. As the sound transmittivity through a plate in water varies with the angle of incidence, the bottom of the Pyrex glass inner container was slanted at the angle where strong transmission occurred. In the slant-bottom container, an intensive and uniform sound pressure distribution was measured with a polyvinylidene fluoride (PVDF) hydrophone probe. In comparison with the conventional horizontal-bottom container, it was shown that the distributions as well as amplitude of sound pressure were remarkably improved by slanting the bottom of the inner container at the proper angle     

Athletes as health testing examinees

AIMS AND BACKGROUND: The usefulness of monoclonal antibodies that recognize markers of neoplastic lesions in complementing conventional cytology was evaluated by the avidin-biotin-peroxidase complex, indirect immunoperoxidase technique. METHODS: In order to enhance the sensitivity of the traditional method, a pool of seven combined monoclonal antibodies (Pool C7), which reacts specifically with cells of epithelial origin and is able to distinguish between mesothelial and malignant cells, was tested on cytologic smears of 262 serous effusions. The effusions were benign or neoplastic, mainly from breast, ovary and lung cancers. RESULTS: Immunocytochemical method showed an 100% specificity and 100% of predictivity whereas the sensitivity was 98%, 96% and 95% for breast ovarian and lung carcinomas, respectively. CONCLUSIONS: The results demonstrated that the pool when used together with conventional methods, is useful in analysis of serous effusions in diagnostic investigations.