• Korean Journal of Culture and Social Issue
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• v.20 no.4
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• pp.281-305
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• 2014

This study investigated the relationship between older driver's safe driving behavior, driving mobility(amount of driving, assessment for driving-related physical ability, confidence for adaptation in driving situation, amount of social activity) and subjective well-being(life satisfaction, positive/negative affect). The data of these variables were collected by questionnaire method based on face-to-face interview. The results can be summarized as followings. First, the older driver who reported higher scores in the self-report safe driving behavior questionnaire tended to show higher level of subjective well-being and driving-based mobility. Second, all the sub-factors in the driving-based mobility questionnaire were positively related to life satisfaction, positive affect but negatively related to negative affect except amount of driving. Finally, it was found that both confidence for adaptation in driving situation and amount of social activity positively mediated the relationship between self-report safe driving behavior and life satisfaction and positive affect, but confidence for adaptation in driving situation negatively mediated the relationship between self-report safe driving behavior and negative affect, Implication and suggestion were discussed.

• Science of Emotion and Sensibility
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• v.19 no.2
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• pp.67-78
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• 2016

The purpose of this study was to investigate relationships among the older drivers' subjective evaluation and objective performances for driving ability, mobility and subjective well-being. Scores for mobility and subjective well-being were obtained using questionnaires. Diagram-based driving scenarios and driving simulation were used to measure subjective and objective driving abilities, respectively. The results can be summarized as followings. First, subjective evaluation scores of driving ability but not objective driving performance significantly correlated with mobility. Second, the higher level of mobility predicted higher life satisfaction, higher positive affectivity, and lower negative affectivity. Third, the older driver's higher scores of subjective driving ability induced higher level of mobility, which, in turn, increased life satisfaction and positive affectivity but lower negative affectivity. The results suggested that subjective rather than objective ability for driving is more important in determining the level of old driver's subjective well-being.

• Korean Journal of Culture and Social Issue
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• v.21 no.3
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• pp.457-479
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• 2015

This study investigated the differential effects of subjective evaluation for attention and situation adaptability, and motivation on driving mobility as a function of driver's age. The results can be summarized as followings. First, subjective capability evaluation tended to decrease as the drivers' age increased, and lower evaluation for situation adaptability seemed to be recognized earlier than attentional ability in middle-aged drivers. Second, although subjective evaluation for attentional ability predicted positively driving mobility of all age groups, but only subjective evaluation for situation adaptability predicted positively driving mobility of older drivers. Third, among motivational elements, BAS predicted positively driving mobility of young and middle-aged driviers, whereas BIS predicted positively driving mobility of older drivers. Finally, middle-aged drivers tended show increased driving mobility when their attentional ability score and BAS were high, whereas older drivers showed lowest level of driving mobility when their situation adaptability score and BIS were low. These results suggest importance of integrated consideration for drivers' subjective evaluation for attention and situation adaptability, and motivation to understand characteristics of driving mobility in different age groups.

• Korean Journal of Culture and Social Issue
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• v.15 no.2
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• pp.251-271
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• 2009

This research measured a concept of mobility which is included objective travel behavior as well as psychological and physical mechanism that influenced travel behavior. And then, this research examined the relation between mobility and the quality of life in elderly drivers. In research 1, to evaluate the reliability and validity of "Mobility Questionnaire(MQ)", we tested "MQ" to 207 drivers aged 20 years and older. In research 2, we examined the mobility level of elderly drivers. Also we investigated the influence that mobility of elderly drivers impacts on their quaility of life. we used "MQ", "Psychological Well-Being Questionnaire(PWBQ)" to 91 drivers aged 65 years and older. To factor analysis, MQ consisted of 'Safe Driving Ability(ADA)', 'Travel Increase(TI)', 'Travel Decrease(TD)', 'Social Activity(SA)', and 'Driving Situational Adaptability(DSA)'. The amount and speed of driving of elderly drivers reduced driving behavior than other drivers. Also, elderly drivers negatively assessed their physical abilities for safe driving and felt a low confidence in specific driving situation. On the other hand, elderly drivers take parts in social activity constructively. A review of the relation of mobility and quality of life showed that mobility of elderly drivers had positive correlation with PWB. Specially, 'ADA', 'SA', and 'DSA' had significant correlations with PWB of elderly drivers. The mobility of elderly drivers had an effect on 'Autonomy', 'Environmental mastery', 'Self-acceptance', and 'Positive relations with others'.

• Science of Emotion and Sensibility
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• v.17 no.4
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• pp.29-40
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• 2014

The positive relationship between older driver's mobility and life satisfaction is well established(e. g., Collins, 2008). The present study showed that this relationship can be changed by older drivers' motivation, aspects of mobility, and affectivity. Specifically, this study examined whether aspects of mobility(amount of driving measured by travel distance and time: 'AD' or amount of driving for social activity: 'DSA') can be differed as a function of approach/avoidance motivation(measured by BIS/BAS scale, Carver et al., 1994) and positive/negative affect(PA/NA; measured by SPANAS, Diener et al., 2009) mediate the relationship between the aspects of mobility and life satisfaction(measured by SWLS, Diener et al., 1985). Self-reported scores of the variables of 132 older drivers(ages of over 65) were analyzed using correlation analysis and path analysis. The results can be summarized as followings. First, the older driver's BAS was found to be positively related to DSA, but BIS was negatively to AD. In particular, DSA positively mediated the relationship between BAS and PA. Second, PA, in turn, positively mediated the relationship between DSA and life satisfaction. The results can provide useful insights to understand the relationship between older driver's driving property, motivation, affectivity and life satisfaction.

• Proceedings of the KIPE Conference
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• 2012.11a
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• pp.9-10
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• 2012

AFD(Active Frequency Drift), SMS(Slip-Mode frequency Shift)를 비롯한 주파수 이동 단독 운전 검출 방법은 단독 운전 발생 후, 계통의 주파수를 정상 운전 범위 밖으로 이동시켜 OUF(Over/Under Frequency) 릴레이를 동작하게 만들어 단독 운전을 검출한다. 이 방법들의 불검출 영역은 알고리즘에 의한 전류 위상각 변화율과 부하 역률 각 변화율 사이의 관계, 그리고 단독 운전 후 정상 상태(steady state) 운전 주파수에 의해 결정된다. 본 논문에서는 불검출 영역에 영향을 미치는 부하 역률 각 변화율을 분석하고 그를 바탕으로, 설계한 Q(Quality)-factor보다 낮은 Q-factor를 갖는 부하 조건에서는 항상 단독 운전을 검출할 수 있는 설계 방법을 제시한다. 제안된 방법의 유효성은 모의실험 및 실험으로 검증되었다.

• Journal of Korean Society of Transportation
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• v.19 no.6
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• pp.33-47
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• 2001

본 연구는 운전자가 음주 후 운전여부를 결정할 때 가장 중요하게 고려하는 음주운전결정요인에 대해 탐색하고, 이들 요인들에 대해 음주운전자와 비 음주운전자 간 차이를 보이는지를 알아보는 것을 목적으로 한다. 이를 위하여 본 연구에서는 집단심층면접과 기존 문헌 고찰을 통해 얻은 음주운전에 영향을 미치는 인지적·사회심리적 요인들을 종합하여 설문지를 작성하였다. 전체 조사대상자는 음주운전 경험이 있는 운전자 136(남자 122명, 여자 13명)명이었다. 연구결과를 살펴보면, 우선 운전자들은 음주 후 운전여부를 결정할 때 1) 음주정도, 2) 음주 후 경과시간 정도, 그리고 3) 다음날 이동시의 불편함, 4) 집과의 거리 정도를 가장 중요하게 고려하는 것으로 나타났다. 다음으로 음주 후 운전여부를 결정할 때 중요하게 고려하는 요인들에 대해 음주운전자와 비 음주운전자 간 차이를 검증해 본 결과, 크게 세 가지 차원에서 차이를 보이고 있다. 첫째, '잘못된 신념'에 해당하는 요인들로 음주운전자들이 비 음주운전자들에 비해 음주단속에 걸리지 않을 것이라는 신념을 가지고 있으며, 음주단속과 교통사고 발생가능성을 낮게 평가하고, 자신의 운전실력을 과신하는 경향이 있다. 둘째, '목전단기이익 추구 경향성'에 해당하는 요인들로 음주운전자들이 비 음주운전자들보다 음주 후 차를 두고 갈 경우 야기되는 비용부담, 다음날 이동시의 불편함 그리고 집과의 거리 정도에 더욱 민감한 것으로 나타났다. 마지막으로 음주운전자들이 비 음주운전자들보다 마신 술의 양(음주량)에 대해 더욱 과소평가하는 것으로 나타났다. 본 연구는 이와 같은 연구결과들을 바탕으로 향후 음주운전에 대한 개선 방안을 함께 제시하고자 한다.

• 한국신재생에너지학회:학술대회논문집
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• 2007.11a
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• pp.161-164
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• 2007

연료전지의 상용화 시점에 이르러 내구성에 대한 기술 확보가 점점 더 부각되고 있다. 현재 연료전지의 내구성을 감소시키는 1차적인 요인은 핵심부품인 촉매, 전해질막, MEA(Membrane & Electrode Assembly) 등에 의한 것이며 2차적인 요인은 운전 시스템 및 환경 등에 의해 결정되어진다. 특히, 연료전지자동차는 이동용, 가정용, 발전용에 비하여 부하변동이 극심한 조건에서 운전되기 때문에 연료전지 시스템의 내구성 확보에 많은 제어기술이 요구된다. 본 연구에서는 연료전지자동차 운전조건(Driving mode)을 부하변동 기준에 의한 고전류, 중전류, 저전류의 3가지 모드로 분류하였다. 각각의 운전조건에서 일정 cycle마다 성능곡선을 측정하여 10만 cycle 이상의 반복운전을 수행하였으며 측정된 성능곡선을 empirical equation에 적용하여 시간에 따른 overvoltage 인자에 대한 분석을 하였다. 운전시간이 증가함에 따라 고전류 모드의 경우 activation overvoltage 인자 중 current density loss가 증가하여 OCV가 급격히 감소하였으나 내구성은 저전류 모드에 비하여 높게 나타났다. 저전류 모드의 경우 고전류 모드와 상반된 결과를 보였으며 성능감소요인은 activation 및 ohmic overvoltage의 점차적인 증가에 의한 것으로 분석되었다.

• Journal of the Korean Society for Railway
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• v.14 no.6
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• pp.575-583
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• 2011

In order to minimize the maintenance cost at local lines, Information & Communication Technology based onboard train control system is being developed. Unlike the central traffic control based fixed block system, this system use a moving block method and railway driver direct control switch and railway crossing. The purpose of this paper is to analyze the concerned main operational issues are as follows: the preparation of train operation, drivability, the role of driver and controller, block system and cost. We defined the role of driver and driver's input data for train service, and we designed the business process of driver using UML tool. We considered the aspect of drivability, DMI is needed to support the braking moment for the driver and driver training simulator. We designed the driver business process for control of switch and railway crossing. We analyzed the fixed block system and moving block system to confirm the difference with the existing operational method. The cost analysis structure is also needed for the operation cost comparison.

• Korean Journal of Human Ecology
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• v.24 no.3
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• pp.341-358
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• 2015

This study aims to identify predictors of driving cessation among Korean elderly. Data from 2011 Elderly Survey conducted by Ministry of Health and Welfare and Korea Institute for Health and Social Affairs were used for the analysis. Based on Webber, Porter, Menec(2010)'s comprehensive theoretical framework for mobility, the model of this study tests five major determinants of driving cessation including financial, psychosocial, environmental, physical and cognitive factors. Results of logistic regression analysis showed that economic status, marital status, contacts with relatives and friends, residential location, taking medication, muscle strength, age, gender, and job were significant predictors of driving cessation of older drivers. Specifically, lower economic status, unmarried status, less contacts with relatives and friends, living in the city, taking medication, weaker muscle strength, older age, female, non-working status were significant risk factors for driving cessation. Practical implications in light of study findings were discussed.