A Bayesian Approach to Asymmetric Multidimensional Scaling

Behaviormetrika - We propose a Bayesian approach to asymmetric multidimensional scaling (MDS), which incorporates an asymmetric data structure. The asymmetry is represented by the hill-climbing...     

Recovery and immobilization of lead in cathode ray tube funnel glass by a combination of reductive and oxidative melting processes

Reductive melting treatment has been reported to be an effective method to recover lead from funnel glass in used cathode ray tubes, but a small amount of lead, a potential contaminant, remains in the treated glass. This paper applied a combination process of reductive and oxidative melting to the funnel glass to recover and immobilize lead in the glass. The funnel glass was melted in a lab‐scale reactor changing the atmosphere, and the effects of the temperature and the Na₂CO₃ dosage on the efficiencies of the lead recovery and immobilization were investigated. In the reductive melting, the lead recovery was promoted by increasing the Na₂CO₃ dosage, however the lead extraction from the glass into water and hydrochloric acid was increased. Although the content of lead in the glass after the reductive melting was low, the lead extraction into water and the acid was larger than 0.01 mg‐Pb/L‐water and 150 mg‐Pb/kg‐glass, respectively (Japanese environmental criteria). The lead extraction was decreased by the oxidative melting with SiO₂, Al₂O₃, MgO, and NaNO₃. In the proposed method, metallic lead was recovered from the funnel glass with high lead recovery, and the lead remaining in the glass was immobilized to meet the Japanese environmental criteria.     

Active adaptation in human-agent collaborative interaction

When a human user interacts with an adaptive agent to achieve human-agent collaboration, active adaptation is considered to be one of the critical characteristics of the agent. In order to investigate the principal features of active adaptation, we developed a human-agent collaborative experimental environment called WAITER (waiter agent interactive training experimental restaurant) and conducted two types of experiments, a Wizard of OZ (WOZ) agent experiment and an autonomous agent experiment. The objective of these experiments is to observe how human users perceive the agents and change their instructions when interacting with adaptive agents. The results indicate that humans can recognize changes in the agent’s actions and change their instruction methods accordingly. This implies that active adaptation of the agents may encourage the adaptation of the human users and help to build an adaptation loop between them. The experimental results also suggest that active adaptation may play an important role in a human-agent collaborative task.     

Pulse ejection presentation system synchronized with breathing

Trials on the transmission of olfactory information together with audio and visual information are currently being conducted in the multimedia field. However, continuous emission of scents in high concentrations creates problems of human adaptation and remnant odors in the air. To overcome such problems we developed an olfactory display in conjunction with Canon Inc. This display has high emission control in the inkjet so that it can provide stable pulse emission of scents. Humans catch a scent when they breathe in and inhale small molecules in air. Therefore, it is important that the timing of scent presentation be synchronized with human breathing. We also developed a breath sensor which detects human breathing‐in (inspiration). In this study, we combined the olfactory display with the breath sensor to make a pulse ejection presentation system synchronized with the breath. The experimental evaluation showed that the system had a detection rate above 90%. Another evaluation was held at Keio Techno‐Mall 2007. From questionnaire results of the participants, we found that the system made the user feel a continuous sense of smell, without the occurrence of adaptation. It is expected that our system will allow olfactory information to be synchronized with audio and visual information for an arbitrary duration and at any time. © 2010 Wiley Periodicals, Inc. Electr Eng Jpn, 174(2): 72–78, 2011; Published online in Wiley Online Library ( wileyonlinelibrary.com ). DOI 10.1002/eej.21086     

Photoemission study on natural oxidation of Cu3Au with synchrotron radiation

We report the results of a study of the natural oxidation of Cu₃Au(110) with high‐resolution X‐ray photoemission spectroscopy in conjunction with synchrotron radiation. The clean surface of Cu₃Au(110) is terminated with 50% Au and 50% Cu atoms. After natural oxidation in the air, Cu atoms segregate on the surface and produce Cu‐oxide. As a result, Au atoms move into the bulk. Au atoms below the oxide reduce the diffusion of O atoms farther into bulk and limit the oxide thickness. The face dependence of natural oxidation indicates that the diffusion of Cu atoms also contributes to oxide formation. © 2011 Wiley Periodicals, Inc. Electr Eng Jpn, 175(4): 43–47, 2011; Published online in Wiley Online Library ( wileyonlinelibrary.com ). DOI 10.1002/eej.21149     

Wall-loss distribution of charge breeding ions in an electron cyclotron resonance ion source

We investigated the ion-loss distribution on the sidewall of an electron cyclotron resonance (ECR) plasma chamber using the 18-GHz ECR charge breeder at the Tokai Radioactive Ion Accelerator Complex (TRIAC). Similarities and differences between the ion-loss distributions (longitudinal and azimuthal) of different ion species (i.e., radioactive (111)In(1+) and (140)Xe(1+) ions that are typical volatile and nonvolatile elements) was qualitatively discussed to understand the element dependence of the charge breeding efficiency. Especially, the similarities represent universal ion loss characteristics in an ECR charge breeder, which are different from the loss patterns of electrons on the ECRIS wall.     

Evaluation of crack nucleation site and mechanical properties for friction stir welded butt joint in 2024-T3 aluminum alloy

In this paper, metallographic observations, hardness measurement, and static and fatigue tests were conducted to investigate the discontinuity states which become crack nucleation sites in friction stir welded butt joints in 2-mm-thick 2024-T3 aluminum alloy and static and fatigue properties of the joint. Because different types of surface finish can be used depending on the application of the joint, several types of surface conditions were tested to evaluate their effect on crack nucleation sites and static and fatigue life. Indentation hardness tests revealed that typical hardness reduction is not necessarily observed on the section of the welding line. Based on fatigue test results, it was confirmed that there are several types of crack nucleation sites for friction stir welding (FSW) joints depending on the surface finish, and the features of the fracture surface also differ depending on the site. Furthermore, the type of discontinuity state affects the fatigue life of the FSW joint.     

Design of a new high repetition rate Nd:YAG Thomson scattering system for Heliotron J

A new high repetition rate Nd:YAG Thomson scattering system has been designed for the Heliotron J helical device. The main purpose of installing the new Thomson scattering system is an investigation of an improved confinement physics such as the edge transport barrier (H-mode) or the internal transport barrier of the helical plasma. The system has 25 spatial points with ～10?mm resolution. Two high repetition Nd:YAG lasers (>550?mJ?at?50?Hz) realize the measurement of the time evolution of the plasma profile with 10 ms time interval. Scattered light is collected with a large concave mirror (D=800?mm,?f/2.25) with a solid angle of ～100?msr. The laser beam is injected from obliquely downward to upward, and obliquely backscattered light is detected (scattering angle is 20°). Model simulation of the polychromator shows the measurable electron temperature and density range are from 10 eV to 10 keV, >5×10(18)?m(-3) within 3% error for the temperature measurement, respectively.     

Multichannel Langmuir probe for turbulence study in Heliotron J

New multichannel Langmuir probe system was developed and installed to Heliotron J. The objective of the new probe is to characterize basic turbulence property and the resulting transport in advanced helical configuration. The probe developed here consists of four sets of triple probe and one pin for floating potential measurement. Initial experiments in neutral beam heating plasma were conducted and fluctuation profile of radial and poloidal electric fields and Reynolds stress were estimated. For precise evaluation of the electric fields and Reynolds stress, a technique to compensate radial change of tilt angle between probe array and magnetic surface was proposed and applied to the initial results obtained in edge region of Heliotron J where the complicated magnetic structure exists.