• Journal of the Korean Society of Physical Medicine
• /
• v.12 no.3
• /
• pp.111-117
• /
• 2017

PURPOSE: To determine the effect of weight ball throw training as a preparatory exercise before golf practice for 8 weeks on back muscle strength, weight shifting of lower body, head speed of club, and driving distance of amateur golfers. METHODS: A total of 18 subjects were randomly assigned to the experimental group (n=9) and the control group (n=9), respectively. For the experimental group, Weight ball throw training was provided to the height of waist and shoulder similar to golf swing with the following schedule: 3 kg weight ball throw training from the first week to the 4th week; 5 kg weight ball throw training from the 5th week to the 8th week. Before and after 8 weeks of training, back muscle strength, weight shifting of lower body, head speed of club, and driving distance of subjects in the two groups were measured. RESULTS: The experimental group showed significant differences in rotational back extension torque, weight shifting of lower body, head speed of club, and driving distance during golf swing (p<.05). However, the control group only showed significant difference in driving distance during golf swing (p<.05). Back extension torque, weight shifting of lower body, and head speed of club showed significant differences between the two groups during golf swing (p<.05). CONCLUSION: Weight ball throw training can positively change rotational back muscle strength, weight shifting of lower body, head speed of club, and driving distance of amateur golfers. Therefore, it might be used as an effective warming up exercise for amateur golfers.

• Korean Journal of Applied Biomechanics
• /
• v.25 no.2
• /
• pp.149-155
• /
• 2015

Purpose : Recently, many researchers and golf coachers demonstrated that X-factor and X-factor stretch had a co-relationship with driving distance. However, its relationship is still controversial and ambiguous. Thus, the aim of this study was to examine the relationship among X-factor, X-factor stretch and swing-related factors, including driving distance in elite golfers. Method : Seventeen male elite golfers (handicap: ${\leq}4$) with no history of musculo-skeletal injuries participated in the study. Thirty spherical retro-reflective markers were placed on including the middle point of PSIS, the right/left ASIS, the right/left lateral acromion of the scapula, driver head and shaft grip. All motion capture data was collected at 100Hz using 6 infrared cameras. Carry distance, club speed, ball speed, smash factor, launch angle, and spin rate were collected from radar-based device, TrackMan. Results : Pearson's correlation coefficient method was used to find the correlations among X-factor, X-factor stretch and swing-related factors. Positive correlations between driving distance and other swing-related factors which include club speed(r=.798, p<.001), and ball speed(r=.948, p<.001) were observed. In contrast to the swing-related factors, X-factor and X-factor stretch had no relationship to driving distance. Conclusion : These results indicate that X-factor and X-factor stretch are not key regulators in driving distance.

• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.16 no.3
• /
• pp.28-38
• /
• 2017

The study is to analyze the aggressive driving behavior in the protected/permissive left turn(PPLT) intersections in Gunsan City. As a result of the logistic regression model, increasing of driver's age and driving experience, non-peak time, no company, sedan and male have a tendency to behave aggressive driving to the opposite vehicles. When the vehicles try to turn the unprotected left in the PPLT intersection, the opposite vehicle drivers recognize them at the aggressive driving behavior if the distance to opposite vehicles is not enough. The relationship between driver characteristics and the distance to the opposite vehicles is analyzed under aggressive driving behavior. increasing of age and company, peak time tend to influence the short distance opposite vehicles while male and higher driving experience the middle and long distance. Sedan has the aggressive possibility to shorter distance opposite vehicles rather than others.

• Korean Journal of Applied Biomechanics
• /
• v.23 no.4
• /
• pp.387-393
• /
• 2013

The purpose of this study was to investigate the difference of kinematic factors acting in the body during a normal swing and a swing taken with an intention to increase driving distance by female pro golfers. Female pro golfers may increase driver clubhead speed and improve driving distance through maintaining a large X-factor angle during backswing and delaying the uncocking period by rapidly shifting the weight to the left foot during downswing.

• Asia-Pacific Journal of Business
• /
• v.14 no.4
• /
• pp.163-174
• /
• 2023

Purpose - This study examines the effect of consumers' motivations on the perception and purchase intentions of electric cars. Specifically, it empirically analyzes how moral motivations based on personal environmental values and norms in car usage and purchasing influence the perceived usefulness and purchase intentions of electric cars. Furthermore, it investigates whether the influence of moral motivations on perceived usefulness and purchase intentions varies according to the user's driving characteristics. Design/methodology/approach - An online survey was conducted with 234 respondents, by setting criteria for participants as car owners or primary car users within their households, ensuring the sample composition was not biased in terms of the presence or absence of experience with eco-friendly cars. Findings - The research findings indicate that perceived usefulness mediates the effect of consumers' moral motivations on their intention to purchase electric cars. The results of the moderating effect of driving distance on perceived usefulness revealed a significant interaction effect; however, there was no significant interaction effect on purchase intentions. Specifically, for individuals with shorter driving distances, as consumers' moral motivations increase, their perception of the usefulness of electric cars also increases. In contrast, for those with longer driving distances, the increase in perceived usefulness due to moral motivations shows a decreasing trend. Research implications or Originality - This study considered individual driving characteristics that previous research on electric vehicle adoption overlooked, and suggested that setting specific communicating points for electric cars according to driving distance levels might be effective. Lastly, it proposes directions for future research that motivations influencing eco-friendly vehicle purchases may differ based on driving characteristics

• The Journal of the Korea institute of electronic communication sciences
• /
• v.13 no.5
• /
• pp.1071-1078
• /
• 2018

In this paper, we implemented community driving system for auto-vehicles as a preceding research of drone's community flight. We used ultrasonic sensors in order to measure the distance between vehicles, and designed each vehicles to maintain specific distance to each other, by making the following vehicle to stop moving when the distance is closed to less than 20cm, to start moving when the distance increases to more than 30cm. We have also designed vehicle to accelerate until the distance is closed to 30cm when they are apart for more than 40cm due to contingencies during driving.

• Journal of the Ergonomics Society of Korea
• /
• v.30 no.3
• /
• pp.403-408
• /
• 2011

The purpose of this study was to investigate the effects of the secondary tasks such as sending text message(STM) and searching navigation(SN) on vehicle speed and distance during driving and brake response time during unexpected situation using a driving simulator. The participants included 19 college students; 9 males aged $25.2{\pm}1.0$ with $2.4{\pm}2.0years$ of driving experiences and 10 females aged $21.4{\pm}0.5$ with $1.3{\pm}0.5years$ of driving experiences. All subjects were instructed to keep a certain distance(30m) from the car ahead and a constant speed(100km/h). Average speed and average following distance were measured during 10 seconds before unexpected situation. Also, brake response time after unexpected situation was measured. Average speed was more decreased and average following distance was more increased during the driving with secondary tasks than driving only. Male maintained the assigned speed and distance better than female. The brake response time was faster during driving only than the driving with secondary tasks. And the brake response time of male was shorter than that of female.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.35 no.2
• /
• pp.9-15
• /
• 2012

The purpose of this study was to investigate the effects of the secondary tasks such as sending text message (STM) and searching navigation (SN) on skin conductance level (SCL) and driving performance of relatively aged and high-experienced drivers. The subjects included 26 taxi drivers; 12 males aged $56.3{\pm}4.4$ with $28.4{\pm}6.4$ years of driving experiences and 14 females aged $55.5{\pm}3.5$ with $19.4{\pm}5.0$ years of driving experiences. All subjects were instructed to keep a constant following distance (30m) from the car ahead and a given vehicle speed (80km/h or 100km/h) in a driving simulator. The relative change of SCL, vehicle velocity deviations, and average following distances were measured during driving only and driving with secondary tasks. The relative change of SCL, average following distance, and vehicle velocity deviation were more increased during the driving with secondary tasks than driving only. The relative change of SCL, vehicle velocity deviation, and average following distance were more affected by driving with 100km/hr than 80km/hr of a given vehicle speed. Secondary tasks increased a work load of drivers in term of SCL change, and decreased driving performance in terms of the vehicle velocity deviation and average following distance.

• Journal of the Korean Institute of Gas
• /
• v.12 no.2
• /
• pp.7-11
• /
• 2008

This paper presents the experimental results on the oil leakage characteristics of stem seals depending on the driving distance in LPG vehicle. The increased speeds of the camshaft and oil temperatures do not affect to the oil leakage of the seals because of the low level of driving distances less than 40,000 km. But the increased driving distance over 50,000 km to 100,000 km shows a rapid deteriorating the sealing performance, which may increase the oil leakage through the rubbing surfaces between the poppet valves and stem seals. In this result, the stem seal may be exchanged about the driving distance of 50,000 km to 60,000 km with a currently used stem seal in LPG car. Thus, the stem seal for a poppet valve should be resigned for the increased durability and long life.

• International Journal of Automotive Technology
• /
• v.7 no.5
• /
• pp.603-608
• /
• 2006

As an important and relatively easy to implement technology for realizing Intelligent Transportation Systems(ITS), Adaptive Cruise Control(ACC) automatically adjusts vehicle speed and distance to a preceding vehicle, thus enhancing driver comfort and safety. One of the key issues associated with ACC development is usability and user acceptance. Control parameters in ACC should be optimized in such a way that the system does not conflict with driving behavior of the driver and further that the driver feels comfortable with ACC. A driving simulator is a comprehensive research tool that can be applied to various human factor studies and vehicle system development in a safe and controlled environment. This study investigated driving behavior with ACC for drivers with different driving styles using the driving simulator. The ACC simulation system was implemented on the simulator and its performance was evaluated first. The Driving Style Questionnaire(DSQ) was used to classify the driving styles of the drivers in the simulator experiment. The experiment results show that, when driving with ACC, preferred headway-time was 1.5 seconds regardless of the driving styles, implying consistency in driving speed and safe distance. However, the lane keeping ability reduced, showing the larger deviation in vehicle lateral position and larger head and eye movement. It is suggested that integration of ACC and lateral control can enhance driver safety and comfort even further.