Methods of EMG-based hand motion classification (EHMC) using classifiers have been developed to control multi-degree-of-freedom myoelectric hands. Though, for forearm amputees, effectiveness of the EHMC methods using classifiers have not been examined enough. This paper describes the effectiveness for seven forearm amputees who have no experience of training for the EHMC and have wide varieties of attributes. Their EMG signals were measured while they performed muscle contractions according to five kinds of motion examples presented in a predetermined order, and EHMC experiments were conducted with the EHMC methods using four different classifiers. As a result, all EHMC methods showed classification rate averaged across all subjects of more than 91%. In particular, the EHMC method using support vector machines showed the highest classification rate of 94.1%, and classification rate of each subject ranged from 98.0% to 90.9%. The results show that the EHMC methods have the effectiveness for amputees who have no experience of the training and have wide varieties of attributes.

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Conventionally, the restaurant industry considers that taste and cost cannot go together. This study conducts a series of experiments that aim to the optimization of cooking processes by balancing cost reduction and improvement of palatability. In the first experiment, it calculates the production cost of three kinds of simmered conger dishes that are cooked by different processes ; factory-made, restaurant-made, and a mixed process of them. 30 adult participants evaluate the tastes of those dishes. In the second experiment, the K value (an index of taste and freshness for ingredients) was measured to elucidate the relationships between taste and cookery procedures. The results suggest that 1) a mixed cookery method (combine factory-made process and chef's restaurant-made process) increases quality of taste and decreases the production cost rather than the restaurant-made method, 2) the quality of taste at the time of consumption in a restaurant can be improved by the control of transit time and ripening time of a material.

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Electromyography-assisted optimization (EAO) is limited in that all Electromyography (EMG) information of main model muscles is needed, although it can predict proper muscle forces. This report proposes how to use muscle forces predicted by classical optimization (OPT) which does not use EMG information as a substitute for EMG activity, and investigates validity of lower muscle forces predicted by this method during gait. Five male subjects walked freely five times. The model we used had three joints and eleven muscles of the lower leg in the sagittal plane. EMG electrodes were placed on eight muscles. Iliopsoas muscle force predicted by OPT was used to substitute for iliopsoas muscle activity. Pearson's correlation coefficients between predicted muscle forces and EMG were used as indices of validity. Results showed that muscle forces predicted by EAO correlated well with EMG (r = 0.74∼0.84). It seems that iliopsoas muscle force predicted by EAO was affected by force of other muscles which our musculoskeletal model did not include. This study suggests, however, that iliopsoas muscle force predicted by EAO was suitable, considering that the eleven muscle forces satisfied joint moment equation and that the muscle forces except iliopsoas muscle correlated with EMG well.

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In a factory, problems such as static muscle load occur when workers elevate their arm while assembling goods by hand or by using hand tools. This study quantitatively assesses the influence of the work-plane height during screw-tightening work using a manual screwdriver on musculoskeletal load. Ten healthy male subjects were asked to carry out screw-tightening work using a manual screwdriver for four work-plane heights in an experimental apparatus. An analysis of the results from the viewpoint of an electromyogram, maximum joint torque ratio, pushing force, degree of subjective fatigue, and subjective difficulty of manipulation suggests that for a work-plane at eye height, the musculoskeletal load and degree of subjective fatigue are the worst. Therefore, the work-plane height strongly influences the elevation of workers' arms, and in turn, the musculoskeletal load. Moreover, the cervical division of the spinal chord is subjected to considerable fatigue when workers have to bend their head back in cases where the work-plane is above their head.

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Physical exercise provides beneficial effects on health enhancement and prevention from care needs. However, it is difficult to continue physical exercise spontaneously. In this paper, we present the concept of the system to promote physical activity that can be used easily at home, and introduce the idea that the system should encourage users to ensure their continuous usage. As a first attempt, we developed a prototype robot to encourage users to start an exercise game. Impressions produced by the encouragement of the real robot compared to that of the 2-D moving image on a computer monitor was analyzed using the semantic differential method. Sixteen male undergraduate students in their 20 s who gave written informed consents participated in the experiment. As a result, more positive scores were obtained in the real robot for 6 of 28 adjective pairs, which suggested that the promotion by the real robot works more effectively.

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We conducted an experiment to investigate the relationship between dynamic changes in the angle and shadow of Noh mask and perceived emotions. We used koomote which is a type of female mask and is the most popular among Noh masks. A factor analysis extracted two factors of “positive emotions” and “negative emotions.” The results also revealed that dynamic changes in the angle and shadow should have strong effects on the perception of emotions in facial expressions for Noh mask and that the effects were stronger both when the face with positive emotions changed into the face with negative emotions and when the face with negative emotions changed into the face with positive emotions.

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