• Journal of the Ergonomics Society of Korea
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• v.24 no.4
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• pp.55-62
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• 2005

This study examined the effect of ergonomic heel rest that was designed for drivers who have physical handicap in the low leg muscles or have to drive prolonged hours with frequent foot pedaling. An experiment was designed to test the ergonomic heel rest with traditional foot pedal. Forty subjects participated in the experiment. Electromyography(EMG) was used to monitor the muscle activity and fatigue of right leg, and Electro-goniometer was used to measure the ranges of motions of the knee and ankle. A simulator of driver's seat was built for the experiment and the heel rest was installed on it. In order to examine the low muscle activity and range of motion, subjects used the foot pedal for 15 minutes repetitively for each experimental condition. Another 15 minutes test without the heel rest was also performed for comparison. The Root Mean Square(RMS) and Mean Power Frequency(MPF) Shift were used to quantify the level of muscle activity and local muscle fatigue. In results, statistically significant decreases of muscle activity and fatigue were found in all the low leg muscles. The range of motion of the knee and ankle joint also decreased when the heel rest was used. The mechanism of the heel rest effect was discussed in this study. This type of heel rest can be applied to real driving situation after ensuring the safety, or overcoming the psychological discomfort possibly due to unfamiliarity.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2012.04a
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• pp.455-460
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• 2012

Thirteen taxi drivers as the subject in the experiment were exposed to vertical vibration which is controlled on a rigid seat reflecting vibration on passenger vehicle. They were employed not only to get human response of objective measurement but also to make subjective evaluation of the vibration. The subjective evaluation was estimated using the absolute discomfort threshold of the controlled vibration, which was achieved with the three-down one-up method that is widely used in the field of psychophysics. As the result, apparent mass and apparent eccentric mass as objective human response tend to gradually decrease when frequency of the vibration increases. The absolute discomfort threshold was increased in case of increasing the frequency. Concludingly, the subjective discomfort evaluation is highly correlated with the objective human responses at the range of idle vibration on passenger vehicle.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.22 no.5
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• pp.422-428
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• 2012

Thirteen taxi drivers as the subject in the experiment were exposed to vertical vibration which is controlled on a rigid seat reflecting vibration on passenger vehicle. They were employed not only to get human response of objective measurement but also to make subjective evaluation of the vibration. The subjective evaluation was estimated using the absolute discomfort threshold of the controlled vibration, which was achieved with the three-down one-up method that is widely used in the field of psychophysics. As the result, apparent mass and apparent eccentric mass as objective human response tend to gradually decrease when frequency of the vibration increases. The absolute discomfort threshold was increased in case of increasing the frequency. Concludingly, the subjective discomfort evaluation is highly correlated with the objective human responses at the range of idle vibration on passenger vehicle.

• International Journal of Automotive Technology
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• v.8 no.5
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• pp.629-636
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• 2007

This paper describes the process of analyzing vehicle stiffness in terms of frequency band in order to improve vehicle handling. Vehicle handling and ride comfort are highly related to the systems such as suspension, seat, steering, and the car body design. In existing analytical processes, the resonance frequency of a car body is designed to be greater than 25 Hz in order to increase the stiffness of the body against idle vibration. This paper introduces a method for using a band with a frequency lower than 20 Hz to analyze how stiffness affects vehicle handling. Accordingly, static stiffness analysis of a 1g cornering force was conducted to minimize the deformation of vehicle components derived from a load on parts attached to the suspension. In addition, this technology is capable of achieving better performance than older technology. Analysis of how body attachment stiffness affects the dynamic stiffness of a bushing in the attachment parts of the suspension is expected to lead to improvements with respect to vehicle handling and road noise. The process of developing a car body with a high degree of stiffness, which was accomplished in the preliminary stage of this study, confirms the possibility of improving the stability performance and of designing a lightweight prototype car. These improvements can reduce the time needed to develop better vehicles.

• Journal of Korean Institute of Industrial Engineers
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• v.39 no.3
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• pp.192-197
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• 2013

In this study, it is investigated the relationship between sitting discomfort and major design variables of lumber support, such as prominence, height and width through volunteer tests. Korean $50^{th}$ percentile males and American $50^{th}$ percentile males are recruited among 36 to 45 years old peoples who have driving experiences and have no back pain during the past 12 months. Subject ratings are asked by changing design variables randomly. Body pressure and lumber position changes are also measured as object measures. And correlation among subject ratings, object measures and three design variables are analyzed using statistical analysis. As a result, it is revealed that prominence is the most dominant factor that correlates to the discomfort strongly for both-Koreans and Americans and contribution of other two variables are very low.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.16 no.6 s.111
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• pp.658-664
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• 2006

Shock vibrations are usually experienced in vehicles excited by impulsive input, such as bumps. The frequency weighting functions of the current standards in ISO 2631 and BS 6841 are to help objectively predict the amount of discomfort of stationary vibration. This experimental study was designed to develop frequency weighting shape for shock vibration having various fundamental frequencies from 0.5 to 16Hz. The specks were produced from the response of single. degree-of-freedom model to a half-sine force input. Fifteen subjects used the magnitude estimation method to judge the discomfort of vertical shock vibration generated on the rigid seat mounted on the simulator. The magnitudes of the shocks, expressed in terms of both peak-to-peak value and un-weighted vibration dose values (VDVs) , were correlated with magnitude estimates of the discomfort. The frequency weighting shapes from the correlation were developed and investigated having nonlinearity due to the magnitude of the shock.

• Journal of Biosystems Engineering
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• v.35 no.5
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• pp.294-301
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• 2010

This study was performed to improve the utilization of the ROPS and seatbelt of tractors in Korea. We surveyed the ROPS and seatbelt use and the tractor related accidents through the personal interviews for 141 farmers. And comfort test for tractor seatbelts is done for 4 different subjects by measuring the body pressure distribution. The survey showed that 79.3% of the tractor accidents was overturning accidents. And, in case the tractor has ROPS and seatbelt, there was no serious injuries. With this results, we could confirm that ROPS and seatbelt is very effective devices for protecting drivers in overturning accidents. But, in case farmers didn't wear seatbelt, there was some fatal injuries. This shows the importance of the seatbelt use in working and driving tractors. Therefore, we tested the comfort of the tractor seatbelt for 4 different subjects operating the pedal in tractor seat simulator and in the tractor running on various roads. From the results of the static test in the Lab, it was shown that more the seatbelt anchorage point is far form SIP point, more the body pressure of the belly became higher, and more the subjects feel uncomfortable. Not only in the static test in the simulator, but also in the dynamic test in riding tractors, it was shown that non retractable seatbelt was more uncomfortable than retractable seatbelt. According to this study, we concluded that we need to promote the utilization of the ROPS and seatbelt use. And, the non retractable seatbelt need to be replaced by retractable seatbelt. Also, we recommend that the seatbelt anchorage position should to be in the seatbelt anchorage area of the ISO 3776 standard.

• Korean Journal of Occupational Health Nursing
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• v.23 no.1
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• pp.20-27
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• 2014

Purpose: This study was conducted to identify the association between emotional labor and job stress in bus drivers, as well as to propose management strategies for job stress. Methods: The study was conducted in February 2013 and involved 182 bus drivers working in the Gyeonggi area. Results: emotional labor was $9.5{\pm}2.34$ on average, and job stress was higher than the median of the same indicator among Korea's workers in the areas of physical environment, job autonomy, and relationship conflicts. Factors that affected job stress was lower if the subjects' Higher values for emotional labor indicated a higher level of job stress. Conclusion: To reduce among drivers, the following measures are necessary: increase the comfort of the driver's seat within the vehicle, provide adequate rest between bus headways, provide comfortable in-house rest facilities, and establish physical training spaces to reduce musculoskeletal disorders as well as programs for reducing back pain. In addition, relationship conflicts may be relieved by increasing job autonomy as much as possible, by granting autonomous control of working hours and bus headways, as well as by banning long work hours. Moreover, various club activities, exercise programs, and counseling programs that workers can be involved in together may be beneficial. This study is significant in that it identified the relationship of the bus drivers' emotional labor and job stress, which has previously been ignored as a research topic. Through its results, this study provides baseline data for the preparation of management strategies that can address the job stress of bus drivers.

• The Journal of the Korea Contents Association
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• v.8 no.2
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• pp.164-172
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• 2008

This paper investigates passengers' perceptions of the importance and satisfaction of airline service quality for improving the quality level of airline service. Importance-performance analysis(IPA) was utilized to analyze the gap between importance and performance of airline service qualify The result showed that passengers' perceptions of the importance and performance of airline service quality differed for Korean international air passengers. In particular, IPA analysis revealed that four attributes 'meal service', 'seating comfort', 'seat space and legroom', 'check-in service' were identified in the Concentrate Here quadrant-perceived to be important, yet perceived as being performed poorly. The airlines operating from/to the Republic of Korea should concentrate on the attributes included in this quadrant to improve the quality of airline service. On the basis of the IPA analysis, airlines should identify their strengths and weaknesses and draw up a plan to maximize their profits.

• Journal of Sport and Applied Science
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• v.5 no.2
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• pp.63-71
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• 2021

Purpose: The purpose of this study, we will evaluate and analyze the importance and performance of Seongnam Football Club visitors using IPA analysis to present new marketing strategies and improvement plans based on the basis of the audience's perception of the team's priority, low priority, and excessive effort. Research design, data, and methodology: In order to achieve the purpose of the study, the survey was conducted on 120 home spectators of Seongnam Football Club, and the analysis of the data was conducted using SPSS Window Version 21.0. Data were analyzed via frequency analysis, exploratory factor analysis, corresponding sample t-test, and IPA analysis. Findings are as follows. Results: First, the first quadrant showed 'The convenience of access to the stadium', 'Parking lot convenience', 'Tournament schedule guidance', 'Providing information about player', 'Providing information about the team', 'Ticket reservation method'. Second, the second quadrant showed 'Players' fan service', 'Cleanliness of toilets', 'A player's level of performance', 'Team's level of play', 'A match against a rival team'. Third, the third quadrant showed 'Indication of facility guidance', 'Seat comfort', 'Team's Star Player Possession', 'Various participation events', 'Gift recommendation'. Fourth, the fourth quadrant showed 'Player-related promotion through media', 'Promote match schedules through media', 'Entrance convenience', 'Ticket Price'. Conclusions: Based on these findings, Factor in first quadrant, fourth quadrant should be kept. On the other hand, factors in second quadrant should be improved as soon as possible while factors in third quadrant can be improved through new marketing strategies in the future. Future implications were discussed.