• 대한물리의학회지
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• 제12권3호
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• pp.111-117
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• 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.

• 한국운동역학회지
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• 제25권2호
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• pp.149-155
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• 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.

• 한국ITS학회 논문지
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• 제16권3호
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• pp.28-38
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• 2017

연구는 보호/비보호좌회전(PPLT) 교차로에서 공격적 운전행태의 영향요인에 대한 분석을 군산시를 대상으로 한다. 로지스틱 회귀모형 결과 운전자의 나이와 운전경력이 증가할수록 비첨두시간대, 동승자가 없는 경우, 운전경력이 많은 경우, 승용차, 남성 등이 대향차량에 영향을 주는 공격적 운전행태를 보인 것으로 분석되었다. PPLT 교차로상에서 비보호 좌회전시 대향차량까지 충분한 거리가 확보되지 않을 경우 공격적 운전행태를 보이게 되는데 공격적 행태를 보인 운전자 속성과 대향차량까지 거리의 관계성을 분석하였다. 나이와 동행자수의 증가, 첨두시간대는 근거리에 위치해 있는 대향차량에 대해 영향을 주는 반면에, 남성 및 운전경력이 높을수록 중거리 및 장거리 대향차량에 영향을 주는 것으로 나타났다. 승용차 보다는 RV 및 대형차량이 거리가 먼 대향차량에 영향을 줄 가능성이 컸다.

• 한국운동역학회지
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• 제23권4호
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• pp.387-393
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• 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.

• 아태비즈니스연구
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• 제14권4호
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• pp.163-174
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• 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

• 한국전자통신학회논문지
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• 제13권5호
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• pp.1071-1078
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• 2018

본 논문에서는 드론의 군집 비행을 위한 선행 연구를 위하여 차량 군집 시스템을 구현하였다. 초음파 센서를 이용하여 거리를 측정하였으며, 차량 간의 거리가 20cm 이하일 경우에는 정지, 30cm 이상일 경우에는 팔로우 차량이 출발함으로써 차량 간의 거리를 유지하도록 설계하였다. 주행 중, 돌발 상황으로 인하여 차량 간 거리가 40cm 이상이 될 경우에는 차량거리가 30cm 이하가 되기 전까지 팔로우 차량의 속도를 높여 거리를 줄이게 되며 30cm라는 거리를 유지하며 군집 주행을 하도록 설계하였다.

• 대한인간공학회지
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• 제30권3호
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• pp.403-408
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• 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.

• 산업경영시스템학회지
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• 제35권2호
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• pp.9-15
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• 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.

• 한국가스학회지
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• 제12권2호
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• pp.7-11
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• 2008

본 논문은 LPG 차량의 주행거리에 따른 스템시일의 오일누설 특성에 대한 실험적 연구결과를 제공하고자 한다. 캠축의 속도와 오일의 온도가 증가하여도 40,000 km 이하의 주행거리를 갖는 스템시일에서는 엔진오일의 누설에 큰 영향을 미치지 못하는 것으로 나타났다. 반면에 주행거리가 50,000 km 이상 100,000 km 정도에서 사용한 스템시일의 경우는 스템시일의 밀봉성에 영향을 미쳐 누설이 급격하게 증가하는 것으로 나타났다. 이것은 포핏밸브와 스템시일 사이의 미끄럼마찰 접촉면을 따라서 오일이 누설되기 때문에 발생한 것이다. 실험결과에 의하면, 현재 LP차량에서 사용하고 있는 스템시일은 주행거리가 $50,000{\sim}60,000\;km$ 정도에서 교환하는 것이 누유특성을 고려하면 바람직하다. 따라서 포핏밸브의 누유를 차단하기 위해 사용하고 있는 스템시일은 보다 향상된 내구성과 수명연장을 위해 재설계되어야 한다.

• International Journal of Automotive Technology
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• 제7권5호
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• pp.603-608
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• 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.