A plastic holographic waveguide combiner for light‐weight and highly‐transparent augmented reality glasses

There is a high demand for light‐weight, stylishly designed augmented reality (AR) glasses with natural see‐through capabilities for the wide‐spread distribution of novel wearable device to general consumers. We have successfully developed a unique production process of a holographic waveguide combiner that enables us to laminate holographic optical elements (HOEs) onto a plastic substrate with optical grade quality. The plastic substrate waveguide combiner has a number of advantages over conventional glass substrate combiners; the plastic substrate makes AR glasses lighter in weight and unbreakable. With the lamination process of HOEs, we can apply them to a various designs to satisfy general customers' wide range of preferences for the style. We also potentially made it possible for the holographic waveguide combiner to be produced in larger volumes at lower costs by using our novel roll‐to‐roll hologram recording and laminating process. In this paper, we present our approach of the plastic substrate HOE production process for AR glasses.     

WOZ experiments for understanding mutual adaptation

A robot that is easy to teach not only has to be able to adapt to humans but also has to be easily adaptable to. In order to develop a robot with mutual adaptation ability, we believe that it will be beneficial to first observe the mutual adaptation behaviors that occur in human–human communication. In this paper, we propose a human–human WOZ (Wizard-of-Oz) experiment setting that can help us to observe and understand how the mutual adaptation procedure occurs between human beings in nonverbal communication. By analyzing the experimental results, we obtained three important findings: alignment-based action, symbol-emergent learning, and environmental learning.     

Simulation study on refractometry by the rainbow method

To realize a high-precision refractive-index measurement by the rainbow method by use of multifringes, the characteristics of several orders of supernumerary bow fringes are made clear by a simulation based on the Huygens-Fresnel principle. The fringe intervals computed are precisely coincident with those obtained in experiments. As a result a suitable combination of the diameter of the cylinder containing the sample and the beam size of the laser has been determined. By use of the characteristic curve of the deviation angle versus the refractive index for each fringe and by the statistical treatment, measurement with high precision was demonstrated.     

Robotic surgery setup simulation with the integration of inverse-kinematics computation and medical imaging

At present, there are representative robot operation systems such as da Vinci and ZEUS which have realized minimally invasive surgery by the use of dexterous manipulators. In the operating room, medical staff must prepare and set up an environment in which the robot has optimal freedom of motion and its functions can be fully demonstrated for every case. The range of motion in which the robot can reach and be maneuvered is restricted by the fixed point of the trocar site. We have developed a preoperative planning system with the function of volume rendering of medical images and automatic positioning by applying an inverse-kinematics computation of surgical robot. The motion of a surgical robot can be simulated in advance with the intuitive interface and kinematics computation program running in the background of the system. If robotic surgery planning with volume rendering of DICOM images is possible, the discussion of a surgical plan can be directly made just after the diagnosis considering the patient-specific structure. This kind of setup platform would be essential for the future introduction of surgical robotics into an operating room.     

Effects of box weight, vertical location and symmetry on lifting capacities and ratings on category scale in Japanese female workers

The aim was to clarify the effects of box weight, vertical location and symmetry on the lifting capacities and subjective burden in Japanese female workers with manual material handling tasks. Sixteen healthy females were tested. They performed 12 different lifting tasks (three heights * two weights * two symmetries). It is difficult for Japanese women to exert dynamic force in lifting a 15-kg weight from the elbow to the shoulder level. A remarkable increase was observed in heart rate and category scale with ratio properties (CR-10) on large muscle group in lifting a 15-kg weight as compared with lifting a 10-kg one. Judging from calculation of the Recommended Weight Limit using the application manual by the National Institute for Occupational Safe and Health, it was also suggested that lifting the 15-kg weight from the elbow to the shoulder level was difficult for female workers. Not only peak force, but also the average upward acceleration and peak velocity were lower in asymmetric liftings than those in symmetric liftings. CR-10 for the left back and right thigh were also higher in 90 degrees right lateral plane lifting than in the mid-sagittal plane. Thus, asymmetric lifting was supposed to impose higher stress on the back contralaterally and thigh ipsilaterally to the location of the weight.     

A live video streaming system for intuitive human-system interaction

In this paper, we propose an intuitive live video streaming system based on virtual reality technologies among people who are far apart. This system is a kind of server-client system, and can provide remote users with virtual 3D audiovisual fields in real time via a very-high-speed network. The server captures audio and video data from its clients, compiles them into a 3D audiovisual scene at a virtual conference, and broadcasts it to the clients. At the present stage, our system captures 2 videos and creates one 3D video at a time. Our system can play 3D audiovisual contents on Windows XP systems as well as on CAVE systems. Currently, our system can play the 3D video contents at about 2.36 fps under a LAN environment. This work was presented in part at the 12th International Symposium on Artificial Life and Robotics, Oita, Japan, January 25–27, 2007     

Early structural change detection as an optimal stopping problem: solution theorem and its proof using reduction to absurdity

The change point detection (CPD) problem in a time series is when it is found that the structure of the data being generated has changed at some time and for some reason. We have formulated structural change detection in a time series as an optimal stopping problem using the concept of dynamic programming (DP), and we present the optimal solution and its correctness by numerical calculations. In this article, we present the solution theorem and its proof using reduction to absurdity.     

Resin micromachining by roller hot embossing

The roller hot embossing is an efficient process of manufacture in which patterns are continuously transcribed on film, etc. Recently, the application of the embossing roll to the manufacturing processes of micro parts is paid attention. In this paper, we examined the development of the embossing roll with patterns of micron level and we tried to make the embossing roll mold by using the LIGA process. In this study, instead of producing embossing patterns directly on the roll surface, we fabricated a flexible thin mold with micro-patterns, which was then wrapped onto a cylinder to form an embossing roll, and tested the soft-mold roller hot embossing method. First, by optimizing UV exposure conditions of UV lithography, we prepared a resist pattern of numerous dots with a diameter of 10 μm, a sag height of 8 μm and a pitch of 20 μm. By Ni-electroforming this pattern, a 50 μm-thick thin mold was successfully fabricated. The 50 μm-thick mold was then wrapped onto a cylinder to form an embossing roll. In the roller hot embossing process, the 10 μm-diameter dot shape was successfully replicated on PET sheets.     

Deposition and microhardness of SiC from the Si2Cl6-C3H8-H2-Ar system

We obtained SiC coating layers on a graphite substrate using hexachlorodisilane (Si₂Cl₆, boiling point 144° C) as a silicon source and propane as a carbon source. We examined the deposition conditions, contents of carbon, silicon and chlorine in the deposits, and the microhardness. Mirror-like amorphous silicon layers were deposited in the reaction temperature range 500 to 630° C. well-formed silicon carbide layers with good adherency to the substrate were obtained above 850° C. The lowest deposition temperature of SiC was estimated to be 750 to 800° C. The Vickers microhardness of the SiC layer was about 3800 kg mm^–2 at room temperature and 2150 kg mm^–2 at 1000° C.     

Investigation on the Microstructure and Mechanical Properties of Ti-1.0Fe Alloy with Equiaxed α + β Microstructures

Metallurgical and Materials Transactions A - In this study, the microstructural characteristics and mechanical properties of Ti-1.0Fe alloy with equiaxed α + β microstructures...