Enabling robots to learn from interactions with users is essential to perform service tasks. However, as a robot categorizes objects from multimodal information obtained by its sensors during interactive onsite teaching, the inferred names of unknown objects do not always match the human user's expectation, especially when the robot is introduced to new environments. Confirming the learning results through natural speech interaction with the robot often puts an additional burden on the user who can only listen to the robot to validate the results. Therefore, we propose a human-robot interface to reduce the burden on the user by visualizing the inferred results in mixed reality (MR). In particular, we evaluate the proposed interface on the system usability scale (SUS) and the NASA task load index (NASA-TLX) with three experimental object categorization scenarios based on multimodal latent Dirichlet allocation (MLDA) in which the robot: 1) does not share the inferred results with the user at all, 2) shares the inferred results through speech interaction with the user (baseline), and 3) shares the inferred results with the user through an MR interface (proposed). We show that providing feedback through an MR interface significantly reduces the temporal, physical, and mental burden on the human user compared to speech interaction with the robot.

It is an urgent need to find an objective way to estimate the degree of fatigue of employees. In this study, we designed a monitoring and estimation system for the degree of fatigue. This paper explains a long-term pedaling experiment that we use it to explore the possibility to use only the time sequence data of head movement during pealing to estimate the fatigue. While we show the possibility for this through experimental data, it is clear that we need to collect more data to establish an estimation method.

In this paper, design of control system and power combination mechanism of a power assist system of the walking chair were discussed based on kinetostatic characteristics of human arm. The walking chair is a welfare walking machine which is an alternative vehicle of the wheelchair, and expected to be driven by user's cranking operation with assisting actuator. To efficiently utilize user's power as much as possible for long locomotion without giving much fatigue to the user while providing comfortable driving feeling to the user, the human arm characteristics were taken into consideration. Kinetostatic characteristics of human arm were experimentally investigated for its modeling. This model was applied to the design of mechanism and control system of the power assist system of the walking chair to provide a good driving feeling, and to reduce the fatigue and improve power efficiency

We have experimentally demonstrated two- dimensional (2-D) photonic crystal (PC) waveguides (WGs) such as straight, bent, Y-branch, directional coupler (DC), and quantum dots (QDs)-based nonlinear optical (NLO) WGs using a GaAs air-bridge membrane with triangular-lattice line-defect WGs. These WGs are necessary for a 2-D PC-based symmetric Mach-Zehnder (PC-SMZ) type ultrafast all-optical switch. Experimental results on the clear observation of the optical interference at the Y-junction DC, nonlinearity-induced phase shift at the NLO waveguide, and transmission spectra in the total PC-SMZ WG configuration will be addressed, as well as measured results on each WG element.

A novel single-mode-single-slip-structure S/sup 3/ optical switch using carrier-induced refractive index change is proposed as a unit cell for a small polarization-independent nonblocking N*N optical switch array. Sixteen S/sup 3/ optical switches have been integrated into a nonblocking 4*4 optical switch array on an InP substrate. The 8-mm-length InGaAsP/InP 4*4 optical array has shown satisfactory switching characteristics and is suitable for larger scale integration of optical switch arrays and also for integration with other active optical devices such as laser diodes.>