Shin-yo Muto

Reliability and Validity of Gait Analysis by Android-Based Smartphone

Smartphones are very common devices in daily life that have a built-in tri-axial accelerometer. Similar to previously developed accelerometers, smartphones can be used to assess gait patterns. However, few gait analyses have been performed using smartphones, and their reliability and validity have not been evaluated yet. The purpose of this study was to evaluate the reliability and validity of a smartphone accelerometer. Thirty healthy young adults participated in this study. They walked 20 m at their preferred speeds, and their trunk accelerations were measured using a smartphone and a tri-axial accelerometer that was secured over the L3 spinous process. We developed a gait analysis application and installed it in the smartphone to measure the acceleration. After signal processing, we calculated the gait parameters of each measurement terminal: peak frequency (PF), root mean square (RMS), autocorrelation peak (AC), and coefficient of variance (CV) of the acceleration peak intervals. Remarkable consistency was observed in the test-retest reliability of all the gait parameter results obtained by the smartphone (p<0.001). All the gait parameter results obtained by the smartphone showed statistically significant and considerable correlations with the same parameter results obtained by the tri-axial accelerometer (PF r=0.99, RMS r=0.89, AC r=0.85, CV r=0.82; p<0.01). Our study indicates that the smartphone with gait analysis application used in this study has the capacity to quantify gait parameters with a degree of accuracy that is comparable to that of the tri-axial accelerometer.

A method for analyzing human assembly operations for use in automatically generating robot commands

A method for describing human movements in symbolic manner converts a human workers movements into sets of parameters (state, movement, rotation). These parameter sets are used to program a robot to perform several tasks. Dextrous movements (extra movements the worker uses to complete a specific task properly) are derived as the difference between the parameter set for the task and the set of parameters common to similar tasks. Experimental results demonstrate the usefulness of this method, and show that some dextrous movements can be automatically generated from human movements.<<ETX>>

Framework and service allocation for network robot platform and execution of interdependent services

This research introduces a framework for network robot platform (NWR-PF) and a service allocation method for heterogeneous distributed robots; they cooperate to perform services that include interdependent tasks. The proposed framework is composed of three layers: connection units, the area management gateway, and the robot-user interaction database. The area management gateway and robot-user interaction database treat the information of the users, robots, services, and service history in a uniform manner, because the connection units hide the differences, such as format and protocol, among the heterogeneous robots. The 4W1H matching method is also proposed for service allocation. The method selects the most suitable robots by comparing the elements of user, robot, and service information. Moreover, it generates robot commands in a common format, by combining the service scenario, and service history. A feature of the method is that both robotic functions to execute service and functions that robots possess are described as independent parameters. After the service trigger is received, both the robot and scenario needed to execute the service are decided by matching these parameters. Experiments show that robots controlled by NWR-PF can perform interdependent services by referring to the service history.

Teaching and control of robot contour-tracking using contact point detection

New methods for teaching and controlling contour-tracking tasks based on contact sensing are developed to improve robotic machining. Accurate contact point detection is introduced to estimating a work contour path with high reliability. These teaching methods reduce the effort for task teaching and improve adaptability to handle changes in task specifications without re-teaching. Real-time contour tracking control using this contact sensing to suppress work uncertainties in process is presented. Experimental results for practical grinding tasks using a 6 DOF manipulator validate our methods.<<ETX>>

Video content recommendation for group based on viewing history and viewer preference

This paper proposes an algorithm to estimate the useful content for known groups. The method makes it possible to recommend for the group such as friends, couple and family. As the first step, we focused on the preference between group members. Our algorithm estimates the preference using rating of individual for video genres and viewing history shared together. Then we judge that the content is useful for the group based on the preference. Evaluation tests show that our proposal algorithm is serendipitous.

A location predictor based on dependencies between multiple lifelog data

In this paper, we propose a method for predicting future locations of a person by exploiting the persons past lifelog data. To predict the future location of a person has many applications such as the delivery of information related to the predicted locations: information with limited lifetimes (sales in a supermarket), weather reports, and traffic reports. Most existing methods for prediction only use historical location data, thus they can only handle regular movements; irregular movements are not considered. Our method predicts future locations by using personal calendar entries in addition to GPS(Global positioning system) data. Using calendar entries makes it possible to predict the locations associated with the irregular events indicated by the entries. We make Dynamic Bayesian Networks models for integrating these different kinds of lifelog data so as to yield better predictions. In experiments on real data, our methods can predict irregular movements successfully even with long lead-times, while matching the accuracy of existing schemes in predicting usual movements.

Accurate contact point detecting using force and velocity information complementarily

A method for detecting the contact point accurately for robot manipulation tasks is presented. Applying motor algebra to unified processing of different types of sensory data effectively combines force, velocity and tool surface normal vectors for contact point detection. The concept of surface velocity condition function (SVF) composed of velocity motor and normal motor is introduced. A method that can improve the accuracy in detecting the surface normal and work contour as well as the contact point is developed, using force and velocity information complementarily. Experimental results for a grinding task show that the detection accuracy is significantly improved in comparison with the method using only force information. The method developed can be applied to a variety of manipulation tasks without learning of detailed trajectory information.<<ETX>>

PoliTel: mobile remote presence system that autonomously adjusts the interpersonal distance

Mobile Remote Presence (MRP) system that uses a smart device such as smartphone and tablet pc as video conferencing equipment is getting popular. There are varieties of smart devices, and the appearance of a smart device varies from one to another. We assumed that the appropriate interpersonal distance for an MRP system varies depending on the appearance of the smart device. To confirm our assumption, we conducted a preliminary experiment. The result of the experiment suggested that the value of the proper interpersonal distance increases as the video size increases. It is known that the task load of the remote operator of the MRP system increases if the operator is forced to manually control the MRP system to keep the interpersonal distance to the appropriate level, which adversely affects the quality of the communication through MRP. To resolve the problem, we propose PoliTel, a novel MRP system which autonomously adjusts the interpersonal distance according to the appearance of the smart device by controlling the position or video size of MRP, and allows the operator to concentrate more on the conversation with the person facing to the MRP system.

Office on Demand: New cloud service platform for carrier

We propose a novel cloud service platform “Office on Demand” (OOD) and its architecture. OOD functions as a cloud service marketplace targeted mainly for small and medium businesses (SMBs) with the needs to quickly prepare an ICT infrastructure for their business, to use network services without a complex configuration setup, and to use mobile terminal devices as fixed terminal devices. We also propose “Hybrid Office Gateway” (HOG), a user side device for OOD, which will give users accessibility to OOD without any complex network settings after subscribing to the fiber-optic network service onto which OOD is built. We have developed an architecture for OOD that can provide “Communication as a Service” (CaaS) + “Software as a Service” (SaaS)” based service for SMBs through cooperation with HOG, and implemented a prototype to examine and evaluate the architecture.

An ontological approach to lifelog representation for disclosure control

In services using lifelog collected continuously and over a long period of time, disclosure control is essential in order to deal with the privacy because this lifelog includes confidential information which users are unwilling to disclose freely. This paper proposes an ontology model for disclosure control needed to handle each users lifelog. The user is able to easily set disclosure rules on his/her diverse data collected from various data sources. Features of the proposed model are as follows: (1) Values can be differentiated by their context, (2) Various time expressions can be handled and (3) Disclosure attribute is set on each lifelog item (fine-grained control). We show an example of implementation and the result of experiments using an implemented system.