Compensation algorithm for the phase-shift error of polarization-based parallel two-step phase-shifting digital holography

We propose an algorithm for compensating the phase-shift error of polarization-based parallel two-step phase-shifting digital holography, which is a technique for recording a spatial two-step phase-shifted hologram. Although a polarization-based system of the technique has been experimentally demonstrated, there had been the problem that the phase difference of two phase-shifted holograms had been changed by the extinction ratio of the micropolarizer array attached to the image sensor used in the system. To improve the performance of the system, we established and formulated an algorithm for compensating the phase-shift error. Accurate spatial phase-shifting interferometry in the system can be conducted by the algorithm regardless of phase-shift error due to the extinction ratio. By the numerical simulation, the proposed algorithm was capable of reducing the root mean square errors of the reconstructed image by 1/4 and 1/5 in amplitude and phase, respectively. Also, the algorithm was experimentally demonstrated, and the experimental results showed that the system employing the proposed algorithm suppressed the conjugate image, which slightly appeared in the image reconstructed by the system not employing the algorithm, even when the extinction ratio was 10:1. Thus, the effectiveness of the proposed algorithm was numerically and experimentally verified.     

Model Test and Consolidation Analysis of Failure of a Loose Sandy Embankment Dam During Seepage

Failures of earth dam embankments and river dikes, which are constructed of sandy soils with low dry densities, have been observed to occur during rising of water levels. In this paper, a large-scale physical model test was conducted in order to investigate the behavior of a small dam embankment as water levels rose. The test results were simulated by use of a consolidation analysis method coupled with an elastoplastic model for unsaturated soils. All parameters used in the simulation were obtained from element tests; oedometer, triaxial compression, soil water retention, and permeability tests. First, in order to verify the parameters identified, direct shear tests were simulated using the consolidation analysis method; results of the simulation and the tests were consistent. From the embankment model test it was found that the crest of the embankment moved upstream at the first stage of impounding and then moved back. After a seepage surface appeared on the downstream slope, tension cracks occurred on the downstream slope, and sliding occurred through the crack and the downstream toe. The results of the simulation were consistent with those of the model test. This consolidation analysis method could be used to simulate the complex deformations induced by saturation collapse and shear strains and even failure behavior. Old embankments constructed with loose densities might have histories in which cracks occurred on the downstream slopes when the reservoir water level rose, and their stabilities might have decreased.     

Solving fuzzy shortest path problems by neural networks

In this paper, we introduce the neural networks for solving fuzzy shortest path problems. The penalization of the neural networks is realized after transforming into crisp shortest path model. The procedure and efficiency of this approach are shown with numerical simulations.     

Evaluation of Tensile Strength and Fracture Toughness of Yttria-Stabilized Zirconia Polycrystals with Fracture Surface Analysis

The tensile strength of yttria-stabilized tetragonal zirconia polycrystals (Y-TZPs) was measured and the fracture surfaces were analyzed with the scanning electron microscope and X-ray microanalyzer. The fracture origins of the pressureless-sintered samples were voids or inclusions such as A1₂O₃, A1₂O₃ with SiO₂, and cubic-ZrO₂, while the fracture origins of the hot isostatically pressed samples were inclusions; no voids were detected at fracture origins. The higher strengths of the hot isostatically pressed samples versus those of the pressureless-sintered samples were consistent with the change in fracture origins. The fracture toughness of the samples calculated from the tensile strength and analysis of the fracture origins was 3.4 to 3.7 MPa √m. These values are lower than those measured with the SEPB method. These discrepancies might be caused by the difference in the state of the fracture origin and its neighborhood, such as the size of the fracture origin and interaction between two surfaces in the precrack.     

Realtime network management support systems at NTT

This paper describes realtime network management support systems which have been developed forntt’s telephone network. In particular, the advanced traffic observation and management information collecting system referred to as Atomics and the traffic congestion control system referred to astcs are presented. The purpose of the development, concept, functions and capabilities of each system are explained. Examples of powerful realtime network management supported by Atomics andTSC are also presented.     

Plastic deformation in diacetylene (PTS) monomer single crystals

The slip systems of diacetylene (PTS) monomer crystals which were deformed with a shear deformation and a micro indentation were determined. The (1 0 0) [0 0 1], (1 0 0) [0 1 0] and (1 0 2) [0 1 0] slip systems eventually were identified as the main slip systems from the stress-strain curves, slip lines and etch-pit arrangements.     

Right visual field superiority for letter recognition with partial report.

Experiments using partial report techniques have typically failed to find left-right visual field differences in the recognition of tachistoscopically presented letter rows. Such data represent a difficulty for theories that emphasize the relevance of cerebral hemispheric asymmetry. It is contended that the end items of a display are critical, and that a truly symmetric display should have both a left and a right end item in each visual field. In the present experiments with 36 righthanded university students, partial report procedures were employed, but a gap was placed between the left and right halves of the display. In the 1st experiment, a single-letter spatial probe procedure was used, and a clear right visual field superiority was found. In the 2nd experiment, a hemifield report procedure was used; the presence of a gap in the display enhanced the right visual field superiority, especially for shorter strings of letters. Results indicate that right visual field superiority can be obtained with partial report procedures under appropriate conditions. (French summary) (19 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Photoelectrochemical observations on chlorophyll- carotene interactions in a lipid bilayer film

Photoelectrochemical investigations were undertaken on energy transfer and other interactions between chlorophyll-a (Chl-a) and β-carotene (Car) in lipid monolayers. A heterobilayer composed of a Chl-a-lecithin monolayer and a Car- lecithin monolayer was prepared on an SnO₂ semiconductor electrode by Langmuir-Blodgett techniques. When the bilayer-coated electrode was irradiated in an aqueous electrolyte, anodic photocurrents due to the sensitizations by Chl-a and Car respectively were observed. The photocurrent efficiency (ratio of photons to electrons) was much for Car (about 10^-3) than for Chl-a (about 10^-1). This large difference permits a quantitative estimation of the energy transfer from Car to Chl-a, based on the concept that the energy transfer results in an increase in the Car- induced sensitized photocurrent. The effect of added Chl-a on the Car photocurrent was measured for heterobilayers with various Chl-a-to-Car molar ratios. The experimental results, as well as theoretical calculations, showed that the Car-to- Chl-a energy transfer is inefficient. The effect of Car on the Chl-a-sensitized photocurrent was also studied with the same bilayer system. The effect was shown to be complex depending on the Car content. A lowering of the Chl-a photocurrent occurred at high Car contents, which is considered to reflect the quenching of the Chl-a excited triplet by Car. The usefulness of the present photoelectrochemical approach for the study of energy transfer between the photosynthetic pigments is demonstrated.