• Journal of the Ergonomics Society of Korea
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• v.25 no.2
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• pp.187-196
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• 2006

This study aims to develop luxuriousness models based on both users' subjective feelings and objective material characteristics of automobile crash pad using Kansei engineering approach. Based on the results of literature survey and FGI, 12 Kansei variables describing look-and-feel and touch feel and crash pad design variables were extracted for systematically developing both a conceptual model of luxuriousness and a questionnaire for Kansei evaluation. A total of 41 various crash pad samples and 60 participants(customers: 30, designers: 30) were employed to evaluate the crash pad samples using the questionnaire with 9-point semantic differential scale and 100-point modified magnitude estimate scale. Based on the survey results, luxuriousness models were developed by using regression and quantification I method. In addition, they were compared and contrasted with respect to the relative importance of Kansei variables. Consequently, the developed luxurious model could suggest the preferred combination of material properties of crash pad.

• Journal of the Ergonomics Society of Korea
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• v.25 no.2
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• pp.125-134
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• 2006

Most users learn new, complex systems through trial-and-error experience rather than referring to the manuals in a cognitive process that is called 'exploratory learning'. While exploring a system, people find prototypical rules for using the system based especially on frequent tasks. The rules are formed from consistent task procedures and well-expected interface elements on the designed system. These rules play the role of the basis of users' knowledge for performing tasks. The decision making to select and apply those rules interacting with an interface can be aided by properly provided hints on the interface. With appropriate hints, users can learn new systems easily and use them with reduced usability problems. This paper first reports an observation of user behavior performing tasks with prototypical interaction rules and finds a sound set of criteria to extract prototypical interaction rules systematically. Two types of hints are defined. Extending hints prompt users to apply prototypical interaction rules beyond well-known tasks. Preventive hints guide users out of possible capture errors by drawing attention to the variation of rules. A systematic and practical method is proposed to identify the opportunities for both types in designing interfaces. It is then verified through a usability test that the proposed method is effective in identifying the locations and types of appropriate hints to reduce or mitigate usability problems.

• Journal of the Ergonomics Society of Korea
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• v.31 no.1
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• pp.165-170
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• 2012

Objective: The aim of this study is to develop new K-OWAS on the basis of the anthropometry of Koreans considering works in shipbuilding and heavy industry for evaluation whole-body working postures. Background: Work Related Musculoskeletal Disorders(WMSDs) were a leading cause of sick leaves and injuries in the industries of our country. Especially, awkward working postures and handling of heavy weight are known as a main cause of WMSDs. OWAS, RULA and REBA are much used as the method for evaluating the awkward working postures. OWAS is the working postures evaluation method that can be used for the evaluation of whole-body working postures. OWAS was the method made based on the anthropometry of the foreigner, working postures and weight does not fit our work state. Method: This method was evaluated considering the anthropometry of the Koreans, working postures and weight in shipbuilding and heavy industry work state in Korea. Results: Correlation of action level of OWAS and subjective discomfort for each body parts were not statistically significant($p{\geq}0.1$). But correlation of action level of K-OWAS and subjective discomfort for torso and waist were statistically significant($p{\leq}0.1$). Conclusion: K-OWAS was suitable in the evaluation of upper body including torso and waist. Application: New method for whole-body working postures from this study prevent WMSDs and help improvement of working environment and design of working method.

• Journal of the Ergonomics Society of Korea
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• v.13 no.1
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• pp.47-58
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• 1994

The purpose of this study was to obtain the basic data for a design for comfort wear. The subjects of this study were 197 women's university stu- dents. The characteristics of their body types and the thickness of subcuta- neous fat at eight body sites were measured. The thickness of subcutaneous fat was measured by both Ultrasonics and with a Skinfold Caliper. The cor- relation between their values and the thickness of subcutaneous fat were compared. The relationship between Rohrer Index and the subject's self- conception of their body was also compared. The results were as follows: 1. The measurement of thickness of subcutaneous fat at triceps and scapula was a little lower, in using Skinfold Caliper method, than Ultrasonics method because of the pressure of the caliper. 2. Correlation between percentage of fat in body and body characteristics was high in order of chest girth > weight > abdomen girth. 3. The thickness of subcutaneous 8 body these sites was high in order of thigh > triceps > scapula > abdomen > suprailiac > chest > calf > forearm. Percentage of body fat has a positive correlation with both average thickness of subcutaneous fat and thickness of subcutaneous fat at triceps. 4. Rohrer Index shows a positive correlation between average thickness of subcutaneous fat and percentage of body fat. 5. About half of subjects of this study thought that they were obese although the data proved otherwise.

• Journal of the Ergonomics Society of Korea
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• v.18 no.2
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• pp.11-24
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• 1999

The purpose of this study was to obtain the basic data for sound wear design. The objects' of this study were 331 women's university students. The eight items were the shoulder length, shoulder slope, height, weight, chest girth, neck girth, back length, and back shoulder width. The shoulder length and slopes were measured, compared with the right, the left, and other items. The results were as follows; The difference between the right and left shoulder length did not nearly appear. The mean of the right shoulder slopes was $21.3^{\circ}$, and that of the left was $21.9^{\circ}$. According to increase of the age, the right and left shoulder slope tends to be higher. The maximum distribution was $20.7^{\circ}$. According to increase of the age, the maximum distribution tends to be higher. The left compared with the right shoulder length, the right shoulder length of 90.3% objects' was longer than that of the left. The right and left shoulder length of 4.2% objects' were same. The left shoulder length of 5.4% objects' was longer than that of the right. The left compared with the right shoulder slopes, the right shoulder slopes of 12.7% objects' were higher than those of the left. The both size of 20.5% objects' were equal. The left slopes of 66.8% objects' was higher than those of the right.

• Journal of the Ergonomics Society of Korea
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• v.19 no.2
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• pp.87-99
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• 2000

This study aims to examine a fuzzy logic-based human expert EMG prediction model (FLHEPM) for predicting electromyographic responses of trunk muscles due to manual lifting based on two task (control) variables. The FLHEPM utilizes two variables as inputs and ten muscle activities as outputs. As the results, the lifting task variables could be represented with the fuzzy membership functions. This provides flexibility to combine different scales of model variables in order to design the EMG prediction system. In model development, it was possible to generate the initial fuzzy rules using the neural network, but not all the rules were appropriate (87% correct ratio). With regard to the model precision, the EMG signals could be predicted with reasonable accuracy that the model shows mean absolute error of 8.43% ranging from 4.97% to 13.16% and mean absolute difference of 6.4% ranging from 2.88% to 11.59%. However, the model prediction accuracy is limited by use of only two task variables which were available for this study (out of five proposed task variables). Ultimately, the neuro-fuzzy approach utilizing all five variables to predict either the EMG activities or the spinal loading due to dynamic lifting tasks should be developed.

• Journal of the Ergonomics Society of Korea
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• v.24 no.3
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• pp.35-41
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• 2005

The KOSHA codes H-31 and H-30 provide general guidelines to establish a prevention program for work-related musculoskeletal disorders(WMSD). Understanding of the components and practitioner needs for a WMSD prevention program is necessary for effective revision and implementation of the KOSHA codes. The present study established a comprehensive structure for a WMSD prevention program and surveyed practitioner needs for the KOSHA codes. The comprehensive prevention program structure, consisting of 7 parts(organization, education, risk management, medical management, program evaluation, and record keeping) and 90 items, was constructed by analyzing WMSD prevention guidelines published by various government agencies such as KOSHA, OSHA and NIOSH. Next, 20 practitioners, from four industry sectors(auto manufacturing, auto part manufacturing, shipbuilding, and machinery), working in a safety and health department or labor union, were interviewed to collect opinions for the KOSHA codes in terms of relevance, government support, and additional information needed. Guidelines of the KOSHA codes requiring modifications and government supports were identified, which can be used to revise the KOSHA codes and to establish a government policy to promote the implementation of the KOSHA codes. Lastly, the survey revealed that integrated, customized, quantitative, and case information for WMSD prevention is additionally needed, which can be used as design guidelines for a WMSD prevention program manual for practitioners.

• Journal of the Ergonomics Society of Korea
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• v.30 no.2
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• pp.357-363
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• 2011

Objective: The aim of this study is to set the design direction of the lift chair's tilting seat for development. Background: Great attention has been shown to the development of senior friendly product, because of increasing elderly population rapidly in Korea. Therefore, we need to study on sit-to-stand(STS) motion of elderly systematically for developing lift chair that is one of senior friendly products. Method: In this study, we analyzed joint moment(knee, hip) and muscle activity (Erector spinae, Rectus femoris, Vastus lateralis) on STS motion of elderly(female, 60~70: 7) and young people(female, 20~30: 7) using 3 dimension motion capture camera, force plate, wireless EMG. Results: The results of muscle activity showed a similar trend but the results of joint moment were a lot of differences between the young and the elderly. Conclusion: The results of knee joint moment suggest the angle(10~30deg)-adjustable seat that can be better than to find the optimal seat's angle. Application: The method and results of this study are expected to develop senior friendly product and verification as well as be available to various application.

• Journal of the Ergonomics Society of Korea
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• v.30 no.2
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• pp.291-296
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• 2011

This study was designed to investigate the effects of an ankle foot orthosis(AFO) with variable ankle joint angles on balance performance in healthy adults. Eighteen healthy adults were recruited in this repeated measures design with subjects as their own controls. An AFO with four kinds of ankle joint angles(-5, 0, 5, and 10 degree) were used and balance performance was measured during single limb standing. Three trials were obtained and then averaged for data analysis. Foot pressure was measured using an F-scan system and muscle activity was measured using an MP150 system. There were significant differences in balance performance with ankle joint angles. An AFO with -5 degrees was associated with significant increases in postural sway(anterior-posterior), and in muscle activity for the medial gastrocnemius and tibialis anterior compared with other degrees of angle. Findings of this study show that angles of an AFO are related to balance performance and a joint angle of 10 degree is effective for promoting joint stability and postural control. This information can be used by clinicians to prescribe AFOs.

• Journal of the Ergonomics Society of Korea
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• v.31 no.2
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• pp.413-419
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• 2012

Objective: This study presents an observation and analysis on behavioral characteristics of old users in comparison to young users in the use of control on display interface. Background: Touch interface which allows users to control directly on display, is conceived as delight and easy way of human-computer interaction. Due to the advantage in stimulus-response ensemble, the old users, who typically experiencing difficulties in interacting with computer, would expected to have better experience in using computing machines. Method: Twenty nine participants who are over 50 years old and 14 participants who are in 20s years old were participated in this study. Three primary tasks in touch interface, which are tap, move, and flick, were delivered by the users. For the tap task, response time and point of touch response were collected and the response bias was calculated for each trial. For the move task, delivery time and the distance of finger movements were recorded for each trial. For the flick task, task completion time and flicking distance were recorded. Results: From the collected behavioral data, temporal and spatial differences between young and old users behavior were analyzed. The older users showed difficulty in completing move task requiring eye-hand coordination.