Michromatic scope for enhancement of color difference

A michromatic (microscope plus chromatic) scope is a device that enhances the color discrimination between two spectral color datasets. Three spectral filters are required, instead of the conventional red, green, and blue filters, for the implementation of a michromatic camera. In this study, we describe two approaches to the design of these filters: in the first case, the design is based on the direct optimization of the filter characteristics (transmittance), whereas in the second case, the design is based on the nonnegative tensor factorization (NTF) of the spectral datasets. A michromatic camera can be implemented using these filters along with compatible postprocessing in‐camera firmware. Here, we performed experiments with two color datasets: one comprising skin and vein colors, and one comprising skin and cosmetics colors. These were further divided into a training set and a test set. The filters were defined using the training set, and the operation of the filters was tested and magnified using the test set. Our experiments demonstrated that the proposed approaches are suitable for color discrimination. For the first color dataset, the enhancement produced using the optimized filters was up to 252% of the original value, and the average color difference ΔE was increased from 2.82 to 9.93. NTF and preprocessing further enhanced the ΔE up to 21.84. For the second color dataset, NTF and postprocessing enhanced the ΔE from 4.33 to 29.19. The proposed discrimination enhancement could be physically implemented in a designated digital charge‐coupled device camera with proper filter installation and compatible postprocessing. © 2010 Wiley Periodicals, Inc. Col Res Appl, 2010     

Usability of AMeDAS Sunshine Duration Data for Statistical Evaluation of Spatial Average Irradiance Fluctuation Characteristics

In order to mitigate the impacts of high‐penetration photovoltaic power generation systems (HP‐PVS) on the electric power system operation, the statistical evaluation of the aggregated power output fluctuation characteristics of HP‐PVS is important. By using the multipoint irradiance data observed for a year in the Chubu region of Japan, we have evaluated the fluctuation characteristics of spatial average irradiance. However, the study period is not enough for a statistical evaluation. Therefore, this study assessed the usability of the sunlight duration data of AMeDAS (Automated Meteorological Data Acquisition System) for the statistical evaluation of fluctuation characteristics in terms of the daily maximum fluctuation width in 120 min. The method of irradiance estimation from the sunlight duration data at single point proposed in the preceding study was modified to be suitable for the spatial average irradiance estimation by taking into account the smoothing effect of irradiance fluctuation among several points. The results suggest that the AMeDAS sunlight duration data would be useful for statistical evaluation of the fluctuation characteristics of the spatial average irradiance of an electric power system service area.     

X-ray diffraction studies on stress transfer of kenaf reinforced poly(l-lactic acid) composite

Mechanical reinforcement of environmentally friendly composite, composed of kenaf fibers as reinforcement and poly-l-lactic acid (PLLA) resin as matrix, was investigated. The stress on the incorporated fibers in the composite under transverse load was monitored in situ and non-destructively using X-ray diffraction. The outer applied stress was found to be well transferred to the incorporated kenaf fibers through the PLLA matrix, which suggests a strong interaction between the fiber and the matrix. In addition, it was also revealed that a silane-coupling treatment to the kenaf fiber was effective for the improvement of interfacial adhesion.     

Nontrivial quantum effect of defect-induced magnetic moments in spin chains

Low dimensional strongly correlated systems have great potential for new quantum devices. Among them, quantum wires are actively investigated with development of new methods based on self-organized formation. For magnetic wires (chains), impurity doping, which causes inhomogeneity of magnetic interaction, can bring new magnetic properties to the systems. In the present study, the effect of inhomogeneity (defect) on magnetic chains with bond alternation is focused on. Defects induce local moments in the magnetic chains at low temperatures. However, depending on the relation of the distance between the defects, the magnetic profile is found to be drastically changed.     

Fast electro‐optical response at low temperature for metal nanoparticle embedded STN‐LCDs (Invited Paper)

Abstract— STN‐LCDs embedded with special metal nanoparticles of Ag/Pd are shown to be useful for a direct‐multiplexed dot‐matrix STN‐LCD with 320 × 240 pixels and show a fast response time by 3–5 times compared to those without nanoparticles. This phenomenon is shown to be attributed to the reduction of rotational viscosity by 70% at room temperature and by 30% at a low temperature (?20°C). The alteration of elastic constants by doping nanoparticles could be also essential.     

Carbon nanotube scanning tunneling microscopy tips for chemically selective imaging

Carboxyl-terminated single-walled carbon nanotubes (SWNTs) were successfully immobilized from solution phases onto the apexes of gold tips for scanning tunneling microscopy (STM). Gold STM tips were first modified with self-assembled monolayers of 4-mercaptobenzoic acid, and its carboxyl groups were used to anchor carboxylated SWNTs through Zn2+ ion-bridged coordination. These SWNT tips gave high-resolution STM images of a diether monolayer formed on the graphite surface. In addition and more importantly, the ether oxygens of the sample molecules were selectively observed as bright spots with the SWNT tips with significantly high reproducibility, which is due to the facilitation of electron tunneling through hydrogen bond interactions between the ether oxygens and carboxyl groups at the end of the SWNT tips.     

Characterization of a β-FeSi2 p-n junction formed by the PECS method

We have fabricated semiconducting β-FeSi₂ bulks without doping and with Mn and Co doping by using a pulse electric current sintering (PECS) method, and explored the possibility of a direct bonding of n-type and p-type β-FeSi₂ bulks to form a p-n junction structure. P-type Mn-doped and n-type Co-doped β-FeSi₂ bulks were obtained by an annealing process at 800-850 °C for 100 h. The PECS was applied to bond the n-type and p-type bulks together for forming a p-n junction structure. We confirmed that the bonding was processed without any change in the β-FeSi₂ phase and was strongly joined with each other. Although we could not obtain the electrical characteristics of the p-n junction, Seebeck coefficients for n-type and p-type β-FeSi₂ in the bonded sample were determined to be −356 and 778 μV/K, respectively. We propose that these results should lead to an expanded use of the sintered β-FeSi₂ bulks in thermoelectric devices.     

Mixture of spherical distributions for single-view relighting

We present a method for simultaneously estimating the illumination of a scene and the reflectance property of an object from single view images - a single image or a small number of images taken from the same viewpoint. We assume that the illumination consists of multiple point light sources and the shape of the object is known. First, we represent the illumination on the surface of a unit sphere as a finite mixture of von Mises-Fisher distributions based on a novel spherical specular reflection model that well approximates the Torrance-Sparrow reflection model. Next, we estimate the parameters of this mixture model including the number of its component distributions and the standard deviation of them, which correspond to the number of light sources and the surface roughness, respectively. Finally, using these results as the initial estimates, we iteratively refine the estimates based on the original Torrance-Sparrow reflection model. The final estimates can be used to relight single-view images such as altering the intensities and directions of the individual light sources. The proposed method provides a unified framework based on directional statistics for simultaneously estimating the intensities and directions of an unknown number of light sources as well as the specular reflection parameter of the object in the scene.