Ministry of Economy, Trade and Industry

An artificial crystal structure has been fabricated exhibiting a full three-dimensional photonic bandgap effect at optical communication wavelengths. The photonic crystal was constructed by stacking 0.7-micrometer period semiconductor stripes with the accuracy of 30 nanometers by advanced wafer-fusion technique. A bandgap effect of more than 40 decibels (which corresponds to 99.99% reflection) was successfully achieved. The result encourages us to create an ultra-small optical integrated circuit including a three-dimensional photonic crystal waveguide with a sharp bend.

The orientation of patches on the surface of an object can be determined from multiple images taken with different illumination, but from the same viewing position. The method, referred to as photometric stereo, can be implemented using table lookup based on numerical inversion of reflectance maps. Here we concentrate on objects with specularly reflecting surfaces, since these are of importance in industrial applications. Previous methods, intended for diffusely reflecting surfaces, employed point source illumination, which is quite unsuitable in this case. Instead, we use a distributed light source obtained by uneven illumination of a diffusely reflecting planar surface. Experimental results are shown to verify analytic expressions obtained for a method employing three light source distributions.

A dexterous micro-manipulation system has been developed for applications in assembling micro-machines, manipulating biological cells, and performing micro-surgery. We have proposed a micro-hand having two fingers, a prototype of which has been designed and built using parallel mechanisms. We discuss the structure of our micro-hand and its operation system. The structure of the two-fingered micro-hand is strongly related to its effective workspace. The design of the micro-hand has been influenced by consideration of the usage of chopsticks. A calibration method based on least-square error is proposed for three degrees of freedom (DOF) translational motion in task coordinates fixed under a microscope. Development of a useful operational device to control the micro-hand is important for achieving dexterous micro-manipulation. A force feedback system would be ideal for such manipulation. In the case of micro-manipulation, though, a sensor with high resolution and multiple sensing axes is needed. There is no sensor meeting this demand currently. In order to achieve micro-manipulation without the force feedback system, an operational system which can be controlled with natural operational feeling like manipulation of actual human hand, is important. We have developed an operational device which is controlled by one hand. The forefinger and thumb are used to manipulate microscopic objects in tele-operation. However, due to kinematic dissimilarity between the master and the micro-hand, the motion of the fingers cannot be directly used as operational signals to move the micro-hand. We have therefore developed an operational strategy which compensates for this dissimilarity, thus providing for easy manipulation.

In the presence of nonnormally distributed asset returns, optimal portfolio selection techniques require estimates for variance-covariance parameters, along with estimates for higher-order moments and comoments of the return distribution. This is a formidable challenge that severely exacerbates the dimensionality problem already present with mean-variance analysis. This article extends the existing literature, which has mostly focused on the covariance matrix, by introducing improved estimators for the coskewness and cokurtosis parameters. We find that the use of these enhanced estimates generates a significant improvement in investors' welfare. We also find that it is only when improved estimators are used that portfolio selection with higher-order moments dominates mean-variance analysis from an out-of-sample perspective. The Author 2009. Published by Oxford University Press on behalf of The Society for Financial Studies. All rights reserved. For Permissions, please email: journals.permissions@oxfordjournals.org, Oxford University Press.

Using Ar beam etching in vacuum, strong bonding of Si wafers is attained at room temperature. With appropriate etching time, the bonding occurs spontaneously without any load to force two wafers together. However, surface roughness of the wafers increases during Ar beam etching. Because surface roughness has a strong influence on wafer bonding, long etching time degrades the bonding strength. Using atomic force microscope, we measured surface roughness enhancement caused by Ar beam etching, and investigated the relationship between surface roughness and bonding properties such as strength and interfacial voids. The results agree well with theoretical predictions using elastic theory and energy gain by bond formation. A guideline for successful room-temperature bonding is proposed from these results.

In almost all of the literature, the diffusion coefficient derived from a conventional transport equation changes with the absorption coefficient when there is a dissipation in the medium. The situation is also the same for the time-independent diffusion equation. In recent numerical simulations made for a biological-mechanical purpose, it happened that the absorption coefficient was increased up to one tenth of the total scattering cross section per unit volume; thereby it was strongly suggested that the diffusion coefficient should preferably be independent of the absorption coefficient. The purpose of this paper is to show theoretically that this is definitely the case. Moreover, several basic equations for applications to optical tomography and photon migration are given.

This paper describes a method for recognizing partially occluded objects for bin-picking tasks using eigenspace analysis, referred to as the "eigen window" method, that stores multiple partial appearances of an object in an eigenspace. Such partial appearances require a large amount of memory space. Three measurements, detectability, uniqueness, and reliability, on windows are developed to eliminate redundant windows and thereby reduce memory requirements. Using a pose clustering technique, the method determines the pose of an object and the object type itself. We have implemented the method and verified its validity.

A time-resolved optical imaging system using near-infrared light has been developed. The system had three pulsed light sources and total 64 channels of detection, working simultaneously for acquisition of the time-resolved data of the pulsed light transmitted through scattering media like biological tissues. The light sources were provided by high power picosecond pulsed diode lasers, and optical switches directed one of the light sources to the object through an optical fiber. The light signals reemitted from the surface of the object were collected by optical fibers, and transmitted to a time-resolved detecting system. Each of the detecting channels consisted of an optical attenuator, a fast photomultiplier, and a time-correlated single photon counting circuit which contained a miniaturized constant fraction discriminator/time-to-amplitude converter module, and a signal acquisition unit with an A/D converter. The performance and potentiality of the imaging system have been examined by the image reconstruction from the measured data using solid phantoms.

Feedforward control of sound and vibration using a neural network-based control system is considered, with the aim being to derive an architecture/algorithm combination which is capable of supplanting the commonly used finite impulse response filter/filtered-x least mean square (LMS) linear arrangement for certain nonlinear problems. An adaptive algorithm is derived which enables stable adaptation of the neural controller for this purpose, while providing the capacity to maintain causality within the control scheme. The algorithm is shown to be simply a generalization of the linear filtered-x LMS algorithm. Experiments are undertaken which demonstrate the utility of the proposed arrangement, showing that it performs as well as a linear control system for a linear control problem and better for a nonlinear control problem. The experiments also lead to the conclusion that more work is required to improve the predictability and consistency of the performance before the neural network controller becomes a practical alternative to the current linear feedforward systems.

The use of simulation is gaining momentum in nurse education across the UK. The Nursing and Midwifery Council is currently investigating the use of simulation in pre-registration nursing. This article gives a brief history of simulation, discusses competence issues and why simulation is best placed to teach nurses in today's health service. An innovative approach to implementing simulation into the nursing curriculum is introduced.

The effect of Ti, V and Al ions on the relative growth rate of L929 cells and MC3T3-E1 cells was investigated by a cell culture method with metallic powders. These powders were sterilized under a U.V. lamp for 6 h, suspended in the medium and extracted for 48 h, 72 h and 96 h in the incubator. After filtering with a 0.2 microns filter, 3.0 x 10(4) L929 cells and 5 x 10(4) MC3T3-E1 cells were seeded in these filtrates of the medium with and without (control) the presence of the metallic powder. The number of cells was counted using a coulter counter from 1 to 7 days. The number of L929 cells after 4 days of incubation was almost similar for Ti and the control, whereas in the case of A1 and V extraction the number of cells was too low as compared to that of the control. The relative growth rate of L929 cells for Ti, A1 and V after 4 days of incubation was about 1, 0.2 and 0.02, respectively. A similar trend was also observed for MC3T3-E1 cells. The effect of the relative growth rate of L929 cells at different extraction times of 48 h, 72 h and 96 h was examined. It was found that the relative growth rate of L929 cells for Ti, A1 and V extraction was almost the same at all three extraction times. A number of 2.0-5.0 x 10(4) cells was seeded in the medium of A1 extraction. The effect of this initial number of cells on the relative growth rate of L929 cells was investigated. The relative growth rate of L929 cells decreased as the initial number of L929 cells increased. Moreover, dilutions from 1 to 10 times in the case of A1 and from 1 to 4000 times in the case of V were made. The relative growth rate became equal to 1 at 5 times dilution for A1 and at 4000 times dilution for V, for both L929 and MC3T3-E1 cells. From the measures of the concentration of the released A1 and V ions on the relative growth rate of L929 cells, it could be seen that there was a marked decrease in the concentrations of A1 and V ions from 0.3 ppm to 0.1 ppm.

Abstract. Bottom‐simulating reflectors suggestive of the presence of methane hydrates are widely distributed below the ocean floor around Japan. In late 1999, drilling of the MITI Nankai Trough wells was conducted to explore this potential methane hydrate resource and a Tertiary conventional structure. The wells are located in the Northwest Pacific Ocean off Central Japan at a water depth of 945 m. A total of six wells were drilled, including the main well, two pilot wells, and three post survey wells at intervals of 10–100 m. All wells except the first confirmed the occurrence of hydrates based on logging‐while‐drilling, wire‐line logging and/or coring using a pressure and temperature coring system in addition to conventional methods. Based on the various well profiles, four methane hydrate‐bearing sand‐rich intervals in turbidite fan deposits were recognized. Methane hydrates fill the pore spaces in these deposits, reaching saturation of up to 80 % in some layers. The methane hydrate‐bearing turbiditic sand layers are less than 1 m thick, with a total thickness of 12–14 m. The bottom depth of high hydrate concentration correlates well with the depth of the bottom‐simulating reflector. Based on these exploration results, the Japanese government inaugurated a 16‐year methane hydrate exploitation program in 2001.

Two main problems to be solved in designing truly effective mobility aids for the blind are: 1) to determine what kinds and how many pieces of information are necessary and/or sufficient to mobilize humans, and 2) to establish the optimal coding and display method of the acquired information.

To analyze the fundamental characteristics of light transmitted through living tissues, we used the Monte Carlo method to trace the paths of the rays incident upon slabs of particles. The slabs contained either (i) two types of scattering particles in a solution or (ii) one type of particle with pigment added to the solution. Temporal analyses of the transmittance have illustrated that the differences in the optical density among the slabs having different absorption coefficients with the same scattering coefficient vary linearly with time. Also, their gradients have been shown to be proportional to the differences in the absorption coefficients, thus verifying the microscopic Beer-Lambert law in highly scattering media when temporally resolved measurement is used.

RATIONALE: Fast-transient outward K(+) (I(to,f)) and ultrarapid delayed rectifier K(+) currents (I(K,slow), also known as I(Kur)) contribute to mouse cardiac repolarization. Gender studies on these currents have reported conflicting results. OBJECTIVE: Key missing information in these studies is the estral stage of the animals. We revisited gender-related differences in K(+) currents, taking into consideration the females' estral stage. We hypothesized that changes in estrogen levels during the estral cycle could play a role in determining the densities of K(+) currents underlying ventricular repolarization. METHODS AND RESULTS: Peak total K(+) current (I(K,total)) densities (pA/pF, at +40 mV) were much higher in males (48.6+/-3.0) versus females at estrus (27.2+/-2.3) but not at diestrus-2 (39.1+/-3.4). Underlying this change, I(to,f) and I(K,slow) were lower in females at estrus versus males and diestrus-2 (I(K,slow): male 21.9+/-1.8, estrus 14.6+/-0.6, diestrus-2 20.3+/-1.4; I(to,f): male 26.8+/-1.9, estrus 14.9+/-1.6, diestrus-2 22.1+/-2.1). Lower I(K,slow) in estrus was attributable to only I(K,slow)(1) reduction, without changes in I(K,slow)(2). Estrogen treatment of ovariectomized mice decreased I(K,total) (46.4+/-3.0 to 28.4+/-1.6), I(to,f) (26.6+/-1.6 to 12.8+/-1.0) and I(K,slow) (22.2+/-1.6 to 17.2+/-1.4). Transcript levels of Kv4.3 and Kv1.5 (underlying I(to,f) and I(K,slow), respectively) were lower in estrus versus diestrus-2 and male. In ovariectomized mice, estrogen treatment resulted in downregulation of Kv4.3 and Kv1.5 but not Kv4.2, KChIP2, or Kv2.1 transcripts. K(+) current reduction in high estrogenic conditions were associated with prolongation of the action potential duration and corrected QT interval. CONCLUSION: Downregulation of Kv4.3 and Kv1.5 transcripts by estrogen are one mechanism defining gender-related differences in mouse ventricular repolarization.

Magnetic-field and temperature dependence of the critical current density ${\mathit{J}}_{\mathit{c}}$ is investigated in epitaxial ${\mathrm{Bi}}_{2}$${\mathrm{Sr}}_{2}$${\mathrm{Ca}}_{2}$${\mathrm{Cu}}_{3}$${\mathrm{O}}_{\mathit{x}}$ thin films. For the magnetic field H applied parallel to the c axis, the flux pinning force density ${\mathit{E}}_{\mathit{p}}$ (=${\mathit{J}}_{\mathit{c}}$B) exhibits clear scaling behavior when H is normalized by the irreversibility field ${\mathit{H}}^{\mathrm{*}}$. The maximum pinning force density scales linearly with ${\mathit{H}}^{\mathrm{*}}$. This is the first observed scaling of ${\mathit{E}}_{\mathit{p}}$ in high-quality thin films of Bi oxides, which we can reasonably explain with flux-creep theory by assuming that the activation energy is proportional to the flux line spacing.

Oral candidiasis is often accompanied by severe inflammation, resulting in a decline in the quality of life of immunosuppressed individuals and elderly people. To develop a new oral therapeutic option for candidiasis, a nonpathogenic commensal oral probiotic microorganism, Streptococcus salivarius K12, was evaluated for its ability to modulate Candida albicans growth in vitro, and its therapeutic activity in an experimental oral candidiasis model was tested. In vitro inhibition of mycelial growth of C. albicans was determined by plate assay and fluorescence microscopy. Addition of S. salivarius K12 to modified RPMI 1640 culture medium inhibited the adherence of C. albicans to the plastic petri dish in a dose-dependent manner. Preculture of S. salivarius K12 potentiated its inhibitory activity for adherence of C. albicans. Interestingly, S. salivarius K12 was not directly fungicidal but appeared to inhibit Candida adhesion to the substratum by preferentially binding to hyphae rather than yeast. To determine the potentially anti-infective attributes of S. salivarius K12 in oral candidiasis, the probiotic was administered to mice with orally induced candidiasis. Oral treatment with S. salivarius K12 significantly protected the mice from severe candidiasis. These findings suggest that S. salivarius K12 may inhibit the process of invasion of C. albicans into mucous surfaces or its adhesion to denture acrylic resins by mechanisms not associated with the antimicrobial activity of the bacteriocin. S. salivarius K12 may be useful as a probiotic as a protective tool for oral care, especially with regard to candidiasis.

Recent advances in robotics have been applied to automation in industrial manufacturing, with the primary purpose of optimizing practical systems in terms of such objective measures as accuracy, speed, and cost. This paper introduces the artificial emotional creature project that seeks to explore a different direction that is not so rigidly dependent an such objective measures. The goal of this project is to explore a new area in robotics, with an emphasis on human-robot interaction. There is a large body of evidence that shows the importance of the interaction between humans and animals such as pets. We have been building a pet robot. As an implementation of an artificial emotional creature, with the subjective appearance of "behaviors" that ape dependent on internal states, or "emotions", as well as external stimuli from both the physical environment and human beings. Human-robot interaction plays a large role, with mutual benefits. The pet robot has visual, audio, and tactile sensors. Olfactory sensors will also be available. The paper describes an algorithm implementing a focus of attention through the integration of those sensors. In particular, simple sound localization will be developed by the robot through the integration of vision and audition, using the interaction of a human being with the robot as the training reference.

The rising speed and dissolution rate of a carbon dioxide bubble in slightly contaminated water were investigated experimentally and numerically. We developed an experimental system that uses a charged-coupled device (CCD) camera coupled with a microscope to track the rising bubble. By precisely measuring the bubble size and rising speed, we were able to accurately estimate the drag coefficient and the Sherwood number for the dissolution rate of gas bubbles at Reynolds numbers below 100 in the transient regime, where the bubble changes from behaving as a fluid sphere to behaving as a solid particle. We also numerically estimated the drag coefficient and Sherwood number of the ‘stagnant cap model’ by directly solving the coupled Navier–Stokes and convection–diffusion equations. We compared our experimental results with our numerical results and proposed equations for estimating the drag coefficient and Sherwood number of the bubble affected by contamination and clarified that the gas–liquid interface of the carbon dioxide bubble in water is immobile. We also show that the experimental and numerical results are in good agreement and the stagnant cap model can explain the mechanism of the transient process where the bubble behaviour changes from that of a fluid sphere to that of a solid particle.

Many different phantoms have been proposed as human head models for experimental estimation of the electromagnetic energy field induced in the human head caused by the use of an RF device. Here, a biotic tissue-equivalent solid phantom is introduced as the human head model realizing the same relative dielectric constant and conductivity as brain tissue and skull layer. This brain-equivalent solid phantom and skull-equivalent phantom make it possible to accomplish highly reliable and precise estimation of specific absorption rate (SAR) in the human head. The phantom models of cube, sphere, and realistic human heads are fabricated. Measurements are performed to estimate the SAR in the human head models exposed to microwave sources by using the thermographic method.