In recent years, the situations related to the use of various devices, human posture using a device, has greatly changed from static to dynamic one (e. g. walking), for the downsizing of devices and the developing of the network infrastructure. It has been demanded that the study on relation usability of downsizing devices between tactual perception, because most of the devices are operated with the fingertip under the dynamic situations of using devices. As there is the finger at the tip of the arm on the human skeleton, it considers that the fingertip direction by comparison with sagittal-horizontal axis changes under the range of motion of arm in response to situations of using device. For these reasons, it expects that the influence of the arm directions become an important factor in relation to usability of mobile device operated mainly with the fingertip. Therefore, the purpose of this study is improving usability of mobile device affected by the arm directions (combination of shoulder rotations and elbow flexions). Considering the effect of the relationship between arm directions and tactual peculiarity, the difficulty of human using tactual perception was investigated from each index (correctness, cognition time (the time touching a test piece by the fingertip), introspection and difficulty of a haptic perception). Moreover, graph of TaDAD, an innovative graph, was comprehendly showed the relationship between arm directions and tactual peculiarity.

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When we shorten speech by playing it back at a higher rate, discourse becomes more difficult to understand. This study proposes a method that facilitates listeners' discourse understanding while listening to speech recordings presented at a higher speed. Since the fluctuation in pause durations within speech is used as a cue to discourse structure, it was predicted that clarifying the differences in pause durations facilitates discourse understanding. In this light, the validity of two methods that clarify the fluctuations in the pause durations was investigated, using a speech-rate decision task. In Experiment 1, we tested a method that shifted the distribution of pause durations to a time range which provided higher discrimination ability, by lengthening the pause durations overall. The method was found not to be effective with respect to shortening speech playing time. In Experiment 2, a method that exaggerated the fluctuations in the pause durations was tested. The results indicated that this method allows the listeners to understand the speech contents even at a higher speech-rate and a shorter playing time.

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Braille-readers find it difficult to read transparent-resinous-ultraviolet-curing-type (TRUCT) Braille signs printed on base-materials on which their forefingers cannot slide easily. In previous study, to reduce this friction, we contrived a thin nylon finger cover and found that normal-vision-subjects' wearing its finger cover enhances the discriminability of TRUCT Braille. However, we had to review finger cover's material make the signals for identifying each dot easier to transmit through the interface material than nylon. We also did not confirm effectiveness of Braille readers' wearing finger cover. In this study, for the purpose of investigating the effect of wearing polyester non-woven fabric finger cover on TRUCT Braille readability, we compared their readability with and without its finger cover. The subjects were 12 Braille learners with acquired visual impairment, who were asked to read randomly selected characters with and without wearing the finger cover. The results show that most participants could read TRUCT Braille significantly faster and more correctly with the finger cover than without it. This result suggests that wearing polyester non-woven finger cover enables the Braille learners to read TRUCT Braille more efficiently.

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Many studies that address fatigue caused by computer use have been based on laboratory experiment using inexperienced students as subjects. The aim of this study is to obtain findings with which to develop a fatigue questionnaire appropriate for experienced, occupational computer users. Beforehand, the authors carried out preliminary investigation and let you describe a tendency of computation fatigue freely. A survey was conducted of heavy computer users, including clerks, salesmen, data entry specialists, and computer software programmers. Students were also surveyed for the sake of comparison. 45 people who work for computer manufacturing, software developing company, governmental office for documentation and student majoring in engineering were surveyed. They described without restriction what kind of condition, which part of body, and what kind of fatigue was appeared. The personal information such as an occupation, gender, years of occupational experience were asked. The authors conducted a detailed investigation for the purpose of finding concrete evidence that fatigue of computer operation is the cause in this investigation. From the detailed investigation of the questionnaire, 51 questions were selected. The type of job and the company which were investigated were almost with equivalence with preliminary investigation, the participants were a total of 106 people. Personal information was the same as the preliminary investigation and the entry method of subjective evaluation adopted a VAS method to evaluate a position. In analysis of the data adopted factor analysis method. The authors use principal factor method for method of factor extraction by factor analysis, number of factor use factor loading, eigenvalue, inside item of interpretable. From detailed investigation, It was seen progress to be necessary to achieve a demand, The tendency that the escape and a fret lead to fatigue and factor out of self-responsibility not to change as having thought a tendency to lead to fatigue. This tendency already shows the contents, and cannot pick up from a certain questionnaire. The aim of this study is getting basics document to make a fatigue questionnaire for a computer user. Although variation was found in the condition of the workers, the importance of the survey is that its subjects were occupational computer users in an actual working environment, as opposed to students in a laboratory setting and it seems that a concrete characteristic of fatigue in computer operation was examined.

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This paper proposes a method for evaluating and revising a hierarchical menu system by using results from a series of usability evaluation experiments. The method consists of two stages. The first stage is to understand the context in which the menu system in question is actually used in real situations by means of intensive interviews. This makes clear the situations in which the user should have difficulty in accomplishing his/her tasks using the menu system. The second stage is to elucidate user's knowledge about the terms used in the menu system which we assume provides the basis for the user to decide which to select when performing the task. This is done by a large scale user test in which a user answers the degree of similarity between the terms used in the menu system and the description of the task he/she has to do by using the menu system. A method for revising the menu system by taking into account the user's knowledge is proposed. We finally show the validity of the proposed method by conducting a user experiment whose results show that the similarity measures are a good predictor for user's menu item selection.

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This paper deals with the path planning of human digits in grasping a cylindrical object with the thumb and index finger. The digit of thumb approached to the cylindrical object along to a tangential line with respect to the lateral of the object. The trajectory of the thumb from initial position to the target could be divided into three patterns, a convex, double convexes, and non-convex type line. These distinctive patterns could be approximately expressed by the Three-order Bezier curve. In the grasping process, the contacted position of the two digits with the lateral of the cylindrical object changes according to the relative target position to the trunk. With reference to the hand posture, grasping motion was performed without bending the wrist region. Therefore, the grasped parts of the cylindrical object depended on the upper limb posture. Considering the obtained characteristics, the approximated model based on the upper limb posture was constructed. As a result, it was confirmed that the suggested model could adequately estimate the contacted position of the thumb with the lateral of the cylindrical object.

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This study examined the difference caused by relaxation resulting from a breathing exercise in healthy females during menstrual cycle as measured by power spectral analysis of heart rate variability (HRV). The subjects were 15 females. The effect of the breathing exercise was measured in terms of HRV before and after a mental task, in both follicular and luteal phases. The results showed that the high-frequency (HF) was increased significantly by the breathing exercise, and the LF/HF was not changed significantly in follicular phase. These results indicated that the parasympathetic tone was increased. On the other hand, HF was not changed significantly by the breathing exercise in luteal phase. Moreover, the LF/HF increased significantly. These results indicated that tension of the sympathetic nervous system was continuous. Therefore, the effect of the relaxation was exhibited in follicular phase, and not in luteal phases. It will be necessary to consider other effective methods including continuous breathing exercise for the relaxation in luteal phase.

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We conducted an experiment in order to examine the usability of three kinds of insulin self-injection devices and the diversity of their usability by age. Participants were 51 adult (19-30 years old) and 48 elderly (60-82 years old) people who have never touched any such devices. Measurements in this study included subjective evaluation through a checklist, required time during operating, and errors encountered in operating the devices. Participants assessed the subjective evaluation after operating these injections, followed by the experimenter measuring the operation time and its errors made. As a result, it found that the different usability between each device and between the two age groups. This result shows that adult group made a higher evaluation of its overall operation, compared to the elderly group which made poor evaluation in certain areas such as the visibility of display and the ease of remembering procedures. As a conclusion, our research indicated the importance of conducting a usability testing and its usefulness.

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The effect of ambient sound conditions on the performance of blindfolded pedestrians to judge direction while walking in a straight line was tested. Subjects were exposed to three different ambient sound conditions while walking in the first experiment. White noise was emitted from one of two loudspeakers placed on the walls of the laboratory half way down path the pedestrians were required to walk down in two out of three conditions. In the other experimental condition, no sound was emitted from the speakers. Twelve blindfolded male subjects aged 21 to 50 years old, were asked to determine the initial walking direction using one of three cues, a sound (white noise), tactile tiles or a wall, at the starting point before walking down the path. Subjects were then asked to walk in a straight line under each ambient sound condition. In experiment 2, the same sound and tactile tiles as were used in experiment 1 were employed as cues for indicating the initial walking direction. The ambient sound conditions were also the same as those used in experiment 1 except that they differed in intensity (high/low). Thirteen blindfolded male subjects aged 21 to 51 years old participated in the experiment.
Both experiments revealed that exposure to ambient sound had the effect of causing subjects to veer significantly from their paths in a direction that was opposite to the source of the sound. Veering from the path was directly proportional to intensity of the ambient sound. Cues for the initial walking direction had no significant effect on the subjects' paths, but the tendency to veer from paths was greater for the auditory cue compared to the tactile cues.

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