The objective of this study is to investigate hwnan operator's perceptual and psychophysical responses to vibrotactile stimulation on various parts of the hand. Using a small vibrotactile display, five different loci of the hand along with two other mechanical parameters consisting vibrotactile stimulations, which are vibration frequency and number of active contactors, were examined for the effects on absolute thresholds. All test variables were found to have significant effects on thresholds. It was observed that absolute threshold is a function of vibration frequency and number of active contactors. Tactile sensitivity was the greatest at the vibration frequency of 240 Hz, and the fingertip was found to be the most sensitive locus on the hand. The area of stimulation on the hand was also found to be significant in that the sensitivity increased with the number of active contactors. The results of the study generally supported those of other previous studies. It should also be noted, however, that the conclusions from the study should be limited to the absolute sensitivity, not to the suprathreshold intensities of normal everyday contact with the hands.

Dynamic motion difference between normal subjects and low-back pain (LBP) patients has been investigated in terms of kinematic variables such as range of motion, velocity and acceleration of the back and hip. Ten healthy subjects and ten LBP patients were recruited in this study. Electro-goniometer such as Lumbar Motion Monitor and Hip Monitor have been used for quantitative measurement of the trunk motion during repetitive flexion and extension for ten seconds. Results indicated that the velocity and acceleration of the back and hip were important parameters to quantitatively identify LBP patients. The consistency of cyclic trunk motion and the relationship between the back and hip were measured in terms of Variance Ratio and Phase Angle in order to accurately assess the motion characteristics of LBP patients. In particular, the hip motion has been proven to be a very important factor in describing the kinematics of damaged lower back. The functional evaluation technique suggested in this study will be a tool to assist physicians for an accurate diagnosis and timely rehabilitation along with current image diagnosis techniques.

A combined PC and TV monitor has been developed in several companies. The characteristics of physical user interface in this monitor are likely to vary from existing monitors. Therefore, two experiments to investigate the physical interface characteristics of this monitor were conducted. The first experiment was to investigate the characteristics of color perception with monitor coating (coating vs. non-coating) and screen brightness (30fL vs. 35fL) in the PC mode. The second experiment was to investigate the characteristics of luminance contrast with monitor coating and image movement (static vs. dynamic) in the TV mode. Twenty-three subjects (male 12, female 11) were participated in this experiment. In the first experiment, average color temperatures were obtained in all experimental conditions. There was a significant difference between coating and non-coating screen at 0.1 level. In the second experiment, average luminance contrasts were obtained in all experimental conditions. There was a significant difference between coating and non-coating screen at 0.05 level. In addition, there was a significant difference between static picture and dynamic picture at 0.1 level.

This paper illustrates the application of Fuzzy Theory and Analytic Hierarchy Process(AHP) for developing Occupational Stress Index(OSI). The purpose of the OSI development is for future prediction and problem solving of prevailing occupational stress. In developing OSI, the concept of fuzzy set theory was introduced to determine the existence and level of perceived occupational stress instead of actually measuring the strain parameters. The AHP is adopted to collect different weighting factors, since there exist various perceptions and responses to the occupational stress by different individuals. The validation study revealed that the OSI is a reliable predictor of work-related accident and illness and the physiological health of employees. Creating preventive measures, such as early detection of stress, proper placement and promotion of employees, and job enlargement will be possible by using this OSI effectively.

The purpose of this study is to study real body size and ideal body shape by considering the degree of satisfaction of body part and understanding body size by the degree of leanness/obesity. The subjects in this study were 420 males from 18 to 25 years old. Body measurements and surveys were taken and analyzed by mean, standard variation, correlation analysis, regression analysis, crosstabulation analysis, cluster analysis, one-way ANOVA, and Duncan's Test. The results of analyses indicate that the subjects tended to be satisfied with thick chest and upper limbs, wide shoulder width, and preferred to be tall and have big hands and feet. By cluster analysis of 19 variables, the subjects were divided into 4 groups, each consisting 41, 138, 134, and 47 males. Because the 19 variables were body measurements transformed to eliminate the body size factor, this classification was considered to express how lean or how obese a human body appears. The results of one way ANOVA and Duncan's Test indicate that, according to the degree of leanness/obesity from Group I (lean tendency) to Group IV(obese tendency), characteristics of the body shape changed as follows; height became lower, limbs became shorter, trunk and limbs became thicker and weight became heavier. Also it showed that Group IV were most satisfied with chest girth, upper limb girth and shoulder width and Group I with height, hip girth and waist girth.

To investigate the difference of sweating reaction by the somato types, we measured total sweat rate, local sweat rate, skin temperature, physiological reaction and psychological reaction at $25{\pm}1^{\circ}C$ and $29{\pm}1^{\circ}C$ under laboratory conditons. Nine healthy adult females were divided into three somato types : slender (3), normal (3) and obese (3). The results were as follows ; Total sweat rate was highest in the obese type, followed by the normal and slender types in order. Local sweat rate was highest in the infrascapular area, and then came breast, the back of the hand, upper ann, anterior leg, and anterior thigh in all somato types. Mean skin temperature was highest in the slender type, and followed the normal and obese types. Rectal temperature, blood pressure and pulse rate were highest in the obese type. Psychological reaction appeared 'hot', 'humid', 'sweaty' as ambient temperature went up. Somato types made little difference in psychological reaction.

This paper suggests a data modeling scheme of human interface elements and their properties for consumer electronic products. The human interface elements were classified into three categories: individual, interaction and integration interface. The representative properties of each interface element were identified, and modeled by using the object-oriented technique. The results of this study are expected to be used for expressing the user interface of consumer electronic products. They are also expected to help understand the relationship between the usability and the user interface elements of a product.

This study reviews usability of PC communication softwares with different dialogue types of user interface. Usability test was conducted to evaluate usability of 3 PC communition softwares which are currently utilized in Korea. Learnability was adopted as an index of usability evaluation, so learning time, testing time and scores were measured as dependent variables. It is suggested that softwares with mixing dialogue type(menu, icon, command) which were implemented in window systems environment were not superior to that with command dialogue type.