Taiki Ogata

Relationship between social interaction and mental health

In order to explore the relationship between human social interaction and mental health, we investigated the correlations between the amount of face-to-face contact time and quantified mental health. Social interaction data were obtained by wearable sensing system for two organizations in Japan. In this study, we regarded face-to-face contact between individuals as social interaction. The mental health of individuals was measured by psychological questionnaire. We found that the social behavioral property of individuals tended to reflect quantified stress in both organizations. The results suggest the possibility that people who experience large amounts of social interaction tend to have less stress.

Design and evaluation of robot patient for nursing skill training in patient transfer

We developed a robot patient for patient transfer training for simulating a patient’s performance during patient transfer and for enabling nurses to practice their nursing skills on it. To realize the robot patient, we focused on addressing the problems of designing its limb actions to enable it to respond to nurses’ operations. RC servos and electromagnetic brakes were installed in the joints to enable the robot to simulate a patient’s limb actions, such as embracing and remaining standing. To enable the robot to automatically respond to nurses’ operations, an identification method for these operations was developed that used voice commands and the features of the limbs’ posture measured by angle sensors installed in the robot’s joints. The robot patient’s performance was examined by a control test in which four experienced nursing teachers performed patient transfer with the robot patient and a human-simulated patient. The results revealed that the robot patient could successfully simulate the actions of a patient’s limbs according to the nursing teachers’ operations and that it is suitable for nursing skill training.

Temporal co-creation between self and others with multi-sensory inputs

This study uses cognitive psychological experiments to elucidate human temporal co-creation with environments or other people. Time series analyses of alternate tapping with constantly paced computer signals (Experiment 1) show some modality-specific features when the participants receive signals through visual or auditory means. Subliminally perturbed signals using sine-wave function (Experimental 2) were revealed as having effects on the participants’ tapping performance especially in visual perturbation. Results from interpersonal tapping tasks (Experiment 3) reveal the emergence of temporal co-creation, including entrainment and mutually complementary relationships depending on the sense modality. These findings can be the underlying basis of the design for natural temporal communication between human and artifacts. � 2006 Elsevier Ltd. All rights reserved.

Mobile Robot Exploration by Using Environmental Boundary Information

We present the method of exploration using environmental boundary information for an indoor map generation problem of a mobile robot. We introduce an exploration method by (i) integration of the exploration method with Reaction-Diffusion Equation on a Graph (RDEG) and connected components labeling and (ii) a replanning framework in updating exploration plan for the currently obtained sensor information. Our approach has been implemented in simulation environments and has been compared with two existing methods: frontier-based exploration method and zig-zag method. The results demonstrate the efficiency of our approach over others. Lastly, the approach was implemented and tested on an actual robot, demonstrating its efficiency in a real-world situation.

Modeling and designing aircraft taxiing patterns for a large airport

At large airports, aircraft takeoff and land simultaneously on multiple runways. As a result, taxiing is a complex and, at times, lengthy process. Planning for aircraft taxiing is an essential design element for the expansion of runways, taxiways, and terminals. Unnecessary taxiing should be reduced. In this study, we develop a taxiing model and calculate the taxiing time. We observed aircraft traffic patterns and listened to the communication of air traffic controllers (ATCs) in order to develop a taxiing model. The developed model was applied to Narita International Airport. We begin by estimating the time required for taxiing at Narita International for 2014. Next, we propose two strategies to reduce the taxiing time. The first strategy involves changes in departure times with controlled intervals between them. In this strategy, the average taxiing time is reduced by 16.5%. The other strategy requires adjustments in the time from the aircraft departure from the terminal to the start of taxiing. In this strategy, the maximum taxiing time is reduced by 11.5%, and the intervals between the terminal departures and taxiing were more uniform.

Fundamental deliberation on exploring mental health through social interaction pattern

In order to clarify the relationship between human social interaction and mental health, we measured face-to-face communication pattern for a few months and conducted a questionnaire on mental health in two organizations in real world. Face-to-face interaction data were measured using wearable sensing system in two organizations in Japan. We extracted some feature values from those two kind data and investigated correlation between them. In this study, we reconsidered social network centrality which means the connection strength between people. We classified the group size of simultaneous interaction and duration of interaction. As results, we found that these factors affected the correlation coefficients between face-to-face interaction and degree of stress.

The effect of voluntary movement on audio-haptic temporal order judgment

In this study, we investigated the effect of active/ passive motion on audio-haptic temporal order judgment. We used a psychophysical method to measure the differences in Point of Subjective Simultaneity (PSS) and Just Noticeable Difference (JND). PSS and JND were measured under “Voluntary” condition, “Involuntary” condition, and “No-movement” condition. Except Voluntary condition, when the haptic stimulus was presented before the auditory stimulus, the two stimuli were more likely to be perceived as simultaneous. PSS and JND of Voluntary condition were relatively smaller than those of Involuntary and No-movement conditions. Each PSS and JND under Involuntary condition was not significantly different from under No-movement condition. These results suggest that the proprioceptive information and the efference copy in voluntary motion accelerates haptic perception and improves the resolution of temporal order judgment for audio-haptic stimulus, while the proprioceptive information alone does not achieve significant effect on the judgment in involuntary motion.

Working Environment Design for Effective Palletizing with a 6-DOF Manipulator

Palletizing is an important and fundamental task for production. We propose a design method to improve the performance of a palletizing manipulator. The working environment must be optimized regarding the base position of the manipulator and the shape and position of the pallet. Designing a working environment is a lengthy process because of the many dimensions of the problem and the necessity of collision-free path planning. To reduce the computation time, the parameters of an environment are quickly evaluated with the proposed method, in which we set passing points to reduce the computation time of path planning. We verify the effectiveness of our method compared with conventional and state–time space methods. We show that the proposed method can obtain effective and convenient solutions when compared to the other methods.

The simultaneous perception of auditory–tactile stimuli in voluntary movement

The simultaneous perception of multimodal information in the environment during voluntary movement is very important for effective reactions to the environment. Previous studies have found that voluntary movement affects the simultaneous perception of auditory and tactile stimuli. However, the results of these experiments are not completely consistent, and the differences may be attributable to methodological differences in the previous studies. In this study, we investigated the effect of voluntary movement on the simultaneous perception of auditory and tactile stimuli using a temporal order judgment task with voluntary movement, involuntary movement, and no movement. To eliminate the potential effect of stimulus predictability and the effect of spatial information associated with large-scale movement in the previous studies, we randomized the interval between the start of movement and the first stimulus, and used small-scale movement. As a result, the point of subjective simultaneity (PSS) during voluntary movement shifted from the tactile stimulus being first during involuntary movement or no movement to the auditory stimulus being first. The just noticeable difference (JND), an indicator of temporal resolution, did not differ across the three conditions. These results indicate that voluntary movement itself affects the PSS in auditory–tactile simultaneous perception, but it does not influence the JND. In the discussion of these results, we suggest that simultaneous perception may be affected by the efference copy.

Robot Patient for Nursing Self-training in Transferring Patient from Bed to Wheel Chair

In this paper, we proposed a robot patient for the nursing training in patient transfer. The robot patient was developed to reproduce the performance of the patients who are suffering from mobility problems. We targeted on the reproduction of movement of the patient’s limbs (arms and legs) with the consideration of physical and voice interaction between the patient and nurse. The robot patient had 15 joints including 2 active joints installed with motors, 4 passive joints installed with electric brakes and 9 passive joints without any actuators. To realize the physical interaction, potentiometer type angle sensors was utilized to detect the rotation angle of the joints of shoulders, elbows and knees. In addition, follow-up control approach was applied to the shoulder joint. By this way the robot could react accordingly when the trainees moved its limbs. A voice recognition module was applied to enable the robot to interact with the trainee by voice. An experiment was performed by a nursing teacher for examine the robot’s performance. The robot patient successfully reproduced the patient’s movement with physical and voice interaction, including embracing, keeping embracing, standing up, keeping standing and sitting down.