In conventional probability-based human reliability analysis, the basic human error rates are modified by experts to consider the influences of many factors that affect human reliability. However, these influences are not easily represented quantitatively, because the relation between human reliability and each of these factors in not clear. In this paper, the relation is expressed quantitatively. Furthermore, human reliability is represented by error possibilities proposed by Onisawa, which is a fuzzy set on the interval [0,1]. Fuzzy reasoning is used in this method in order to obtain error possibilities. And, it is supposed that many basic events affected by the above factors are connected to the top event through Fault Tree structure, and an estimate of the top event expressed by a member- ship function is obtained by using the fuzzy measure and fuzzy integral. Finally, a numerical example of human reliability analysis obtained by this method is given.

Brain potential is described using the mesocolumnar activity defined by averaged firings of excitatory and inhibitory neuron of neocortex. Lagrangian is constructed based on SMNI(Statistical Mechanics of Neocortical Interaction) and then Euler Lagrange equation is obtained. Excitatory neuron firing is assumed to be amplitude- modulated dominantly by the sum of two modes of frequency .omega. and 2 .omega. . Time series of this neuron firing is calculated numerically by Euler Lagrangian equation. I .omega. L related to low frequency distribution of power spectrum, I .omega. H hight frequency, and Sd(standard deviation) were introduced for the effective extraction of the dynamic property in the simulated brain potential. The relative behavior of I .omega. L, I .omega. H, and Sd was found by parameters .epsilon. and .gamma. related to nonlinearity and harmonics respectively. Experimental I .omega L, I .omega. H, and Sd were obtained from EEG of human in rest state and of canine in deep sleep state and were compared with theoretical ones.

The research on the factors which effect on legibility is mainly utilized as the basic data of selecting the standard guideline of VDT screen. But the research on Korean is scarcer than that of English. Furthermore, it is unreasonable to apply the results of the foreign language to Korean, beause of the difference between the typography of English and that of Korean. Therefore, more systematic and ergonomic research of the Korean typography on VDT screen is needed. In this paper, an experimental study on search speed and error rate is designed and performed according to different Korean letter size and font on search task with VDT. The experimental screen based on popular Ming and Gothic style is made up of total 12 artificial screens, each 6 different font size. As the criteria of the performance, searching speed(s.s.) and error rate (e) are selected, and CFF value is measured to evaluate user's visual fatigue. The results of experiment in font show that the Korean Gothic style is superior to the Korean Ming style in user's visual performance. The letter size that gives user the optimal performance ranges from the visual angle 39.8' to 55.5' in Ming style, from the visual angle 39.8' to 52.6' in Gothic systle. In visual fatigue experiment, the better performance of letter size is, the less tired user feels. And the smaller letter size is, the more tired user feels. There is no relationship between font and user's visual fatigue.

With a view to providing basic data for designing male's and female's clothes, healthy males and females(five each) were exposed to three different environmental temperature($20{\pm}1.0^{\circ}C$, $28{\pm}1.0^{\circ}C$, $32{\pm}1.0^{\circ}C$) in the nude. Their adaptation of skin temperature, physiological responses( rectal temperature, blood pressure, pulse rates) and psychological reactions(thermal, comfort and perceptive sweaty sensations) were analyzed as follows; The subjects's skin temperature had a similar look of adaptation, but the stability of skin temperature differed at tha $20{\pm}1.0^{\circ}C$ and at the $28{\pm}1.0^{\circ}C$ Males had higher skin temperature at three environmental temperatures, but females showed a higher temperature change at the $20{\pm}1.0^{\circ}C$ and $28{\pm}1.0^{\circ}C$ and males at the$32{\pm}1.0^{\circ}C$ Thus females were more resistant to the cold, while males were more resistant to the heat. As environmental temperature increased, rectal temperature and pulse rates also grew up. Females turned higher in rectal temperature and lower in blood pressure, but both sexes had a normal range of physiological reactions. Even though three environmental temperatures were same changes in thermal sensation at $28{\pm}1.0^{\circ}C$and in perceptive sweat sensation at $32{\pm}1.0^{\circ}C$, two sexes had the same response in comfort sensation at the three environmental temperatures.

In industrial designing of ready-to-wear shoes, one important factor to consider is that the population has diverse fooot shapes as well as foot length. The general shape of a foot could be represented by "foot ratio", i.e. the ratio of width to length. In this study, we measured several dey aspects of young Korean men's foot, and compared the results with their shoe sizes and general foot shapes. To this end, 172 male subjects were categorized according to their shoe size (small, medium, large) or foot ratio (wide, narrow, intermediate). The statistics of this survey indicated that the people with narrow foot shap have significantly greater foot length compared with the one having wide foot shape. Conversely, subjects having wide foot shape manifested significantly greater foot and ankle girth as well as significantly greater foot breadth. However, different foot shape groups showed no significant differences in heel width, heel ankle girth, instep height, and malleolus height. On the other hand, subjects wearing larger shoe size showed significantly larger foot measurements except instep and ankle heights, whereas subjects with shoe sizes 260 and below measured significantly more narrow heel and lateral metatarsal breadths. The deviation between foot length and dress shoe size(length) was greater in groups with wide foot shape and in groups wearing large shoe sizes. The results of this survey indicated that the subjects with wide foot shape apparently choose a size or two larger shoes for them as a compromise for a better breadth fit.eadth fit.

Daily exposure to constrained body postures and deviations from neutral postures over a long period may result in discomfort as well as pains and aches in the muscles, joints, tendons, and other soft tissues. Furthermore, it was known that poor body postures are a major cause of musculoskeletal disorders in industry. Therefore, in this study, comfort ranges of joint motions were obtained as a criterion for evaluating body postures and designing workplaces ergonomically, which were bases on subjects' perceived discomfort level estimated by magnitude estimation. Nineteen healthy male subjects participated in the laboratory study. They results showed that comfort ranges of joint motions occurred in the wrist, elbow, neck, and ankle were little less than their normal range of joint motions, but those in the back(L5/S1) and hip joint were much less than their normal ones. This fact implies that the back and jip movements are more stressful than the other joints movements. It is expected that comfort ranges of joint motions can be used as a valuable guideline when designing and evaluating workplaces.

The Human Sensory Feedback Laboratory, park of the Armstrong Laboratory at Wright-Patterson Air Force Base, Ohio, is involved in the development and evaluation of systems that provide sensory feedback to the human operator in telerobotic and virtual environment applications. Specific projects underway in the laboratory are primarily concerned with the information provided by force and vibrotactile feedback to the operator in dextrous manipulation tasks. Four specific research projects are described in the present report. These include : 1) experiments evaluating a 30-element fingertip display, which employs a titanium-nickel shape memory alloy actuator design to provide vibrotactile feedback about object shape and surface texture ; 2) of a fingertip force-feedback display for 3-dimensional information about object shape and suface texture ; 3) use of a force- feedback joystic to provide "force tunnel" information in pilot pursuit tracking tasks ; and 4) evaluations of a 7 degree-of-freedom exoskeleton used to control a robotic arm. Both basic and applied research questions are discussed.

Our recent work on virtual environments and virtual displays is reviewed, including our efforts to establish the Virtual Environment Research, Interactive Technology, And Simulation (VERITAS) facility and our research on spatial hearing. VERITAS is a state-of -the-art multisensory facility, built around the ${CAVE}^{TM}$ technology. High-quality 3D audio is included and haptic interfaces are planned. The facility will support technical and non-technical users working in a wide variety of application areas. Our own research emphasizes the importance of auditory stimulation in virtual environments and complex display systems. Experiments on auditory-aided visual target acquistion, sensory conflict, sound localization in noise, and loxalization of speech stimuli are discussed.