Objective: The purpose of this study was to investigate the changes in foot morphology and foot motion using a multi-segment foot model, and ground reaction forces during prolonged walking in healthy middle-aged females. Background: As people have experienced improved cardiovascular and muscularskeletal health, the popularity of prolonged walking has increased. However, only a few studies have suggested that prolonged walking may increase the risk of lower extremity joint injuries due to abnormal loading and decreased stability after muscle fatigue. Method: Forty-two healthy middle-aged females (mean age: $45.4{\pm}2.3years$, mean height: $160.7{\pm}4.8cm$, mean weight: $59.2{\pm}6.9kg$, mean foot size: $23.3{\pm}0.7cm$) participated in the study. The participants went through measurements of foot morphology and Q- angle before and after 40 minutes' walking. The participants were asked to walk at a speed of 1.1m/sec for 40 minutes. Foot motion and ground reaction forces were collected at three time intervals (0, 20 and 40 minutes). Changes in variables were compared at an alpha level of .05 using a paired t-test and repeated ANOVA, respectively. Results: Arch index was decreased and Q angle was increased after 40 minutes' walking (p < 0.05). Increased toe out angle and attack angle of the foot at initial contact were observed as walking time progressed (p < 0.05). Increased flexion angles of multi-segment foot were found with increased walking time (p < 0.05). Finally, the participants experience greater braking force after 40 minutes' walking compared with 0 minutes and after 20 minutes (p < 0.05). Conclusion: The participants experience kinematic and kinetic changes of the foot during a prolonged period of walking. Application: The current findings suggest important biomechanical considerations when applying a walking intervention in a clinical trial to improve fitness or in developing adequate walking shoes.

Objective: This study examines the variables related to eye-activity which could calculate and quantify a user's flow level in three types of smartphone games. Background: The issue of flow level or addiction related to digital media has mushroomed. Method: A total of 25 subjects participated in this experiment. Three different types of smartphone games, utilizing the different flow experiences as defined by user questionnaire, were used for the experiments in this study. We measured the pupil size, blink rate and blink duration of the experiments' participants using an eye-tracking device called FaceLab. Deeper flow experiences corresponded with bigger pupil sizes. Results: The results showed that pupil size and blink rate differed statistically by game type and game time. Puzzle game showed a higher pupil size than dot-to-dot and coloring games. Pupil size showed differed by game time (p<0.05) and large pupil size showed in the final period. Blink rate differed statistically by game time (p<0.01) except game type. Blink duration did not differ statistically by independent variables. Conclusion: A quantitative study of the flow experience could help solve the problem in a measure of media flow level. Despite the spread of digital-media flow level, there have not been many studies on the actual effects of these flow level. Application: To prevent this issue from getting too far out of hand, this study examines different types of mobile games addiction using variables of eye-activity: pupil size, blink rate, and blink duration.

Objective: This study proposed an IoT-based traffic safety management system appropriate for the environment as a whole and specifically roads in rural area. Background: A recent increase in agricultural machine-related traffic accidents resulting from a rapid rise in motorized agricultural machines has become an important issue in rural societies. The mortality rate of agricultural-related traffic accidents is very high and such accidents incur loss of labor force and a lot of costs, and therefore measures to reduce such accidents are required. Method: This study analyzed the types of agricultural machine-related traffic accidents aimed at designing an agricultural machine-related traffic safety system appropriate for topographic characteristics of rural areas, and presented an effective agricultural machine-related traffic accident prevention system using IoT technology. Results: This study proposed a traffic safety maintenance system utilizing IoT technology to connect between terminals installed on agricultural machines and terminals for providing traffic information, and designed the structure of the system, its communication method, hardware and software, and user interface. Besides, this study presented a real-time monitoring system that senses agricultural machine-related machine accidents and makes it possible to rapidly cope with them. Conclusion: The IoT-based traffic safety system for agricultural machines proposed by this study is expected to become an effective measure to prevent agricultural machine-related traffic accidents. Application: The results of this study will be able to be utilized to construct a system to keep traffic safety via IoT-based agricultural machines.

Objective: The purposes of this study were to validate the accuracy of AWBA (Agricultural Whole Body Assessment) by comparing with expert's evaluation and to suggest the improvements of AWBA based on the results of this study. Background: In the agriculture field, many tasks could have awkward postures such as back, neck, and knee flexion according to the crops and growing processes. Many risk assessment tools such as RULA (Rapid Upper Limb Assessment), REBA (Rapid Entire Body Assessment), OWAS (Ovako Working posture Analysis System) have been used to quantify these awkward working postures. However, existing posture assessment tools were developed focused on the manufacturing industry, not on the agricultural tasks which require different types of working postures with the industry sites. Thus there are many limitations for applying these assessment tools to evaluate agricultural working postures. To overcome these limitations, AWBA has been developed with focusing on the agricultural tasks. Method: The validation study of AWBA was conducted based on comparison with the expert's evaluation results. For validation study, a total of 80 working postures were selected from pepper and bean crops. At least one representative working posture was obtained from each unit work for each crop, and the experts were asked to evaluate subjective risk levels for all 80 working postures with 4 risk levels. To compare the agreements between AWBA analyses and experts' evaluations vs. between other existing assessment tools' analyses and experts' evaluations, percent of agreement and weighted kappa analysis were applied. Based on these results, improvements of AWBA were also suggested in this study. Results: The largest percent of agreement (44.4%) was obtained from AWBA and it is significantly larger than the percent of agreement of existing assessment tools [RULA (28.3%), REBA (37.6%), OWAS (28.6%)]. Kappa values of AWBA and REBA were 0.44 and 0.47, which means 'moderate consistency' also significantly larger than results of RULA and OWAS. Results also showed that there are some difference between AWBA and expert's evaluation at the back flexion posture (at $90^{\circ}$) and standing posture. Based on this, ABWA was revised and thus a revised Kappa value has been changed to 0.62 which means 'substantial to almost perfect'. Conclusion: The agreement between AWBA and expert's results was significantly higher than existing assessment tools. However some revisions were needed to improve the accuracy of AWBA. Thus, AWBA was revised based on the results of this study and the revised AWBA which was improved has been suggested. Application: The results of this study could be applied for evaluation of agricultural working postures and may lead to improve the accuracy of risk evaluation in agricultural field. Eventually, it could improve the work environment and reduce work-related musculoskeletal disorders.

Objective: The aim of this study is to investigate several factors that affect the drivers' turn signal light usage. Background: If drivers' use of the turn signals increases, the traffic accident rate can be significantly lowered. Many countries are making a variety of efforts to increase the driver's use of turn signals. However, studies on factors affecting the use of turn signal lights have not yet been conducted in various ways. Method: Observational study and questionnaire study were conducted together. In the observational study, we observed how the turn signal usage rate varied by six variables; four situations in which the driver should use the turn signal lights, the driving time, the driving location, the driver's use of the safety seat belt, the driver's sex and whether or not the vehicle in front of the observed vehicle uses turn signal lights. In the questionnaire study, participants were asked two questions; of the situations in which the driver must use the turn signal lights, the situation with the highest priority and why not using the turn signal lights. Results: As a result of observational study, the usage rate of turn signal light was 67.3%. According to the result of the Chi-square test, the usage rate of the turn signal light was different according to five factors among the six factors. There was no difference in the usage rate of turn signal light according to driver's sex. The results of the questionnaire study showed that the priority of using turn signal lights was lowest in the situation of lane change and that the most important reason why drivers do not use turn signal lights was that there is no rear vehicle. Conclusion: According to the observational study, drivers' turn signal light usage was variable due to various factors. This may be because many drivers do not use the turn signal lights unconsciously and tend to use the turn signal lights selectively depending on the circumstances. The tendency to use no turn signal in the absence of the following vehicle, as shown in the results of the survey, also mean that drivers do not unconsciously use turn signals. In order to improve the level of traffic safety, it is necessary to increase the factors that have a positive effect on the usage rate of the turn signal lights, and at the same time encourage drivers to use the turn signal lights habitually. Application: The results of this research can be useful in designing a plan to increase the driver's turn signal light usage rate.

Objective: We conducted an experiment about consumer preferences with chicken types and sauces to provide an implication for chicken menu development. Background: In the food service industry, chicken franchises have studied the consumer preferences for the menu development to enhance its competitiveness. It was necessary to investigate the preferences for the chicken types and the sauces sufficiently since cooking methods and sauces for chicken have been diversified. Method: We compared three types of chickens and four sauces. 30 Participants evaluated each combination of chicken types and sauces in terms of the flavor, texture, appearance and satisfaction. Results: The flavor of chickens with a spicy sauce and no sauces was preferred. The oven chicken with barbecue sauce showed a higher flavor than other chicken combinations, and the crispy chicken with chili sauce had a higher flavor than other chicken combinations. Participants also had higher appearance scores for red sauces. Overall satisfaction was affected by flavor, texture and appearance in order. Conclusion: In chicken menus, fried chicken and spicy chicken must be provided. Barbecue sauce matched well with oven chicken and chili sauce was good for crispy chicken only. When developing new chicken menus, we should focus on flavor and texture. Application: This results can contribute to chicken menu developments to enhance the competitiveness of chicken franchises.

Objective: The purpose of this paper is to define the type of car sharing service suitable for autonomous vehicles. Background: Ergonomics has a wide range of research areas. Diversity of research topic is one of the major strong points of this discipline especially in the era of fusion. Dominant areas among the diversity changed from time to time. It is interesting to study the attributing factors of the dominant areas. Method: Researched and analyzed cases of car sharing services at home and abroad, and then classified them from the perspective of service design (User, Provider, Tool, Service). Based on this researched, it was defined as a type of autonomous vehicle sharing service. Results: From a service design perspective, there are eight types that are derived, and they are divided into stages according to the degree of community activation. Conclusion: A shared model type based on a human and local community that can increase user confidence by activating the community of users using the service. Application: This study can be most meaningful in defining the autonomous car sharing model in the future.

Objective: This study is to investigate the long-term effect of ergonomic intervention in a manufacturing company after legal enforcement for preventing work-related musculoskeletal disorders (WMSD). Background: It is rare to measure and follow the risk level of process for twelve years after legal enforcement on WMSD. Method: This study measured and traced; (1) the risk score (frequency ${\times}$ intensity) of KOSHA GUIDE H-9-2016, (2) REBA score and (3) ANSI Z-365 score for 12 years, i.e., four consecutive risk assessment in a company. Results: The risk levels measured by KOSHA GUIDE H-9-2016 and ANSI Z-365 showed significant decrease over four consecutive risk assessment. Conclusion: The results shows that risk levels have decreased significantly since the legal enforcement for preventing WMSD began. Application: It would be useful as basic data to justify the ergonomic intervention in reducing WMSD in manufacturing industries.