In the present study, accelerated plethysmography (APG) obtained through a small near-infrared radiation sensor was used to measure pulse wave velocity (PWV). This study included 51 asymptomatic participants (aged 21–90 years), who were assigned to 3 groups : young (n=14), middle-aged (n=21), and older (n=17). Pulse transmission times (PTT) were determined using electrocardiography (ECG) and APG in the head, finger, and plantar. The measuring distances were estimated using tape measure over the body surface. PWV was calculated for each segment as the measuring distance divided by the corresponding PTT. To confirm the accuracy of the PTT obtained from ECG and APG, twelve of 51 participants had PTT measured by previous methods. The PTT obtained from ECG and APG was significantly correlated with the PTT obtained from previous methods (Pearson's correlation, P<0.001). The PWV including the abdominal aortic systems (heart-plantar PWV, head-plantar PWV, and finger-plantar PWV) significantly increased with age (analysis of variance, P<0.001 ; single liner regression, P<0.001). However, the PWV not including the abdominal aortic systems (heart-head PWV, heart-finger PWV, and head-finger PWV) were not affected by age. After the multiple regression analysis controlling for age, sex, height, BMI, R-R interval, systolic blood pressure and diastolic blood pressure, relationships between the PWV including the abdominal aortic systems and age were still significant (multiple regression analysis, P<0.001). These tendencies were similar to those observed in previous studies and agree with the elastic and muscular artery properties. Although the measurement of PWV using the methods employed in the present study is simple and rapid compared to the previous methods, the methods of present study compares favorably with the previous methods for the measurement of PWV.

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The present study aimed to identify potential indices of mental fatigue. The participants were 15 male university students. After providing written informed consent, the participants performed a 5-minute rest period, mental arithmetic tasks (five 20-minute trials), a 5-minute rest period, and also a 5-minute rest period after a 20-minute recovery period. After each period, subjective ratings of mental fatigue were collected and the participants' performance on a simple visual search test was measured. Physiological indices were measured during both the tasks and all the rest periods. In order to investigate the indices that show mental fatigue, a comparison was executed between the results during three rest periods; before and after tasks, and after the recovery period. Significant changes were detected in subjective evaluations of fatigue, search time in the visual search test, heart rate, nasal tissue blood flow, the coefficient of variation of R-R intervals on ECG, and the total power of heart rate variability and its low frequency component. These changes were considered to be caused by mental fatigue. The results suggested that these indices could be used to assess mental fatigue.

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The knowledge of skilled cooks at the Shimonoseki fish market was analyzed to develop a quality evaluation system for dressed Tiger puffer (Migaki). A total of 100 fish dressed by the cooks were graded into five classes to determine what aspects of the surface color, freshness and the texture of the fish the cooks use for evaluation. Analysis of the appearance evaluation by the cooks, combined with information on fish coloration and meat freshness, indicated that the cooks focused on the color at four points on the surface of the fish. It was also clarified that the evaluation by the cooks accurately corresponded to the freshness of the fish meat. A statistical model was then constructed and evaluated using the colors of these measuring points as four explanatory variables, and the results corresponded with the assessments by the cooks with more than 70% certainty. The results confirm the validity of the proposed method, which incorporates the knowledge of skilled cooks in the design of a dressed Tiger puffer quality evaluation system.

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Nurses working at hospitals, especially nurses of middle standing affect not only the quality of nursing activities but also nursing teamwork. Therefore, they stand at a cross road for their future career development. On the basis of data of 1273 nurses whose career ranged from 4 to 10 years, which were obtained from the questionnaire survey carried out at 256 hospitals spread across the country, the properties of skill acquisition process were identified. Using the ISM (Interpretive Structural Modeling) technique, the skill acquisition process was visually presented to clarify the relevance between nursing skills. As a result of the analysis, the procedure for skill acquisition was clarified using the identified ISM chart. This enables us to understand what kinds of skills are necessary for compensating for the lack in some skills, and to establish guidelines for enhancing the skill of nurses of middle standing.

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In this study, velocity adjustment of robots through the use of degree adverbs was investigated. First, the relative values that humans assign to degree adverbs were experimentally quantified, after which a method to convert these values to actual velocity adjustments of robots was proposed. As an evaluation of the proposed method, experiments in which participants attempted to adjust the velocity of a one-dimensional robot from an initial value to a target value by accelerating and decelerating the robot were conducted. The results indicated that the target velocity could be achieved for both the acceleration and deceleration using four or less adjustment steps, which demonstrates the effectiveness of the proposed method.

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This study employed auditory and visual stimuli to investigate the relationship between eye movement and mental stress. Ten participants were asked to perform complex (subtracting a two-digit value from a three-digit one) and simple (adding two single-digit values) calculation tasks presented on a computer display or recited by a computer voice. As a control condition, participants were asked to listen to a recitation along with the auditory presentation. During the visual presentation, significant differences in the ratio that the participants cast their eyes on the display were observed in three tasks. Moreover, in the complex calculation task, the ratio was significantly higher during the visual presentation than during the control condition. The active index of the parasympathetic nervous system (HF/(LF+HF)) during the calculation tasks tended to be lower than during the control task. From the analysis of eye movement data divided into periodic parts, in the visual presentation with the answering period of complex calculation task, where participants did not require to watch the display, eye movements outside the display were observed to be uniform. Moreover, eye movement in the lower side of display tended to be frequent than that in the upper side. These results suggest that eye movement was influenced by not only mental stress but also sensation modality.

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