• KDI Journal of Economic Policy
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• v.16 no.3
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• pp.125-146
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• 1994

본(本) 논문(論文)에서는 1993년에 퇴직한 공무원(公務員)들에 대한 자료(資料)를 사용하여 이들의 시간할인율(時間割引率)을 측정하였다. 시간할인율(時間割引率)은 여러 경제학 모형에서 개인(個人)의 소비(消費)와 저축행태(貯蓄行態)를 결정짓는 중요한 요소로 등장한다. 시간할인율(時間割引率)을 추정한 기존의 실증분석(實證分析)들은 1% 내외의 매우 낮은 추정치(推定値)를 보고하고 있으며, 심지어 음(-)인 경우도 있다. 이러한 낮은 추정치는 시간할인율(時間割引率)이 실질적으로 거의 아무런 역할을 하지 않음을 의미한다. 그러나 기존의 실증분석(實證分析)은 대부분 거시(巨視) 시계열자료(時系列資料)를 사용하여 경제내의 대표적(代表的) 개인(個人)(representative individual)이라는 가상적 존재의 시간할인율(時間割引率)을 추정하였다는 단점을 갖는다. 본(本) 논문(論文)에서는 우리나라의 퇴직공무원들에 대한 미시(微視) 횡단면자료(橫斷面資料)를 사용하여 실존하는 각 개인(個人)의 시간할인율(時間割引率)을 추정하였고, 그 결과 기존의 연구(硏究)에서와는 달리 시간할인율(時間割引率)이 평균적으로 14~15% 정도의 매우 높은 값을 가짐을 발견하였다. 이러한 결과는 개인(個人)의 노후생활(老後生活) 안정(安定)을 위한 저축(貯蓄)을 각 개인(個人)의 자발적인 의사에 일임하기보다는 공적(公的), 사적연금제도(私的年金制度)를 통하여 강제하는 것이 합리적일 수 있음을 보여준다.

• Journal of Korean Society of Transportation
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• v.31 no.1
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• pp.57-64
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• 2013

Recently, bicycle accidents have increased with the ever-increasing number of cyclists. Bicycle accidents occurred frequently in intersections, and the perpendicular collision between a right-turning car and a crossing bicycle was the most prevalent accident type. In particular, the collision was caused by motorists' carelessness. In other words, the accident-involved motorists did not pay sufficient attention to a bicycle crossing behind them. Another cause was a cyclist's higher speed than pedestrians. This paper evaluated the potential risk of the collision between right-turning cars and crossing bicycles based on simulation experiments, with motorists' speed and carelessness focused on. Consequently, it was found that to reduce the potential risk of the collisions a motorist should slow down and pay more attention to the rear sight by turning his/her head.

• 한국노년학
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• v.30 no.3
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• pp.843-853
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• 2010

The purpose of this study is to find out the characteristics of elderly pedestrian accidents and to suggest policy implications to enhance the level of elderly pedestrian safety. Although much efforts has made to enhance traffic safety environment, pedestrian traffic accidents among elderly population are not significantly decreased. This is mainly because current traffic safety measures do not much consider the characteristics of elderly pedestrians in the aspects of physical and psychological conditions. Main findings from vehicle-pedestrian traffic accident data and survey are as follows. First elderly pedestrians have high probability of traffic accident near crosswalks or cross streets rather than on crosswalk or cross streets. Second they need more green light time for crossing the streets. Third, they feel motor cycles running on the side walk and parked vehicles on the side walk are the most dangerous factors. Forth, general drivers do not have reasonable understanding for the walking behaviors of elderly pedestrians. Fifth, elderly pedestrians frequently need to rest while walking. Sixth, elderly people do not see clearly or understand traffic signs. Finally, many elderly pedestrians experience accidents or inconvenience while walking on the sidewalk.

• Journal of the Korean Geographical Society
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• v.44 no.2
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• pp.176-186
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• 2009

Transportation policy to facilitate the public mode use is of the foremost importance to the local governments of Metropolitan Seoul, regarding the economic and environmental consequences of the increasing use of car. Understanding the travel behaviour is essential to the establishment of proper policy to guide more people to the use of public modes instead of private. The paper reports a result of sequential analysis of individual travel behaviour in Metropolitan Seoul, using a multi-dimensional motif search technique applied to Smart Card data that integrates individuals' different public mode uses. Groups of travel patterns with similar sequential information identified distinctive travel behaviour between Seoul north and south and between metro and bus uses. Travel patterns are more bounded within north Seoul and south Seoul respectively than crossing Han River between north and south. Within north and south, travel patterns visiting northern CBD and southern CBD, respectively, as well as their local neighbour in north and south, often use metro and metro-local bus combination, while travel patterns visiting only the north and south locals without CBDs more use only the local bus line and even only the areal bus line.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.4D
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• pp.369-376
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• 2010

At present, many problems in traffic operation and safety occurs since there is no clear design criteria on designating the not-permitted entrance/exit section at curb areas within complex areas. Even, there is no specific and detailed researches on the not-permitted entrance/exit section by now. This research calculated the proper length of the entrance/exit section at curb areas by dividing the access not-permitted section into the two sections. First, the calculation of the entrance section was done by considering the location of crosswalks, stop line clearance, the queue length of vehicles approaching to second lanes, and marginal distance for safety have been considered. Second, the calculation of the exit section was done by comparing and analyzing the distance between cars of the entrance section according to the investigation point and the distance considering the location of crosswalks, the behavior of exit vehicles and the length of vehicles. In conclusion, by presenting the proper length in consideration of the traffic operation and safety on the access not-permitted section within complex areas, it can be used as a traffic safety improvement alternative and will be contributed in establishing and operating the proper installation criteria for the access not-permitted section within complex areas.

• Journal of Energy Engineering
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• v.22 no.1
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• pp.1-7
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• 2013

This paper attempts to estimate the residential electricity demand function, using survey data of 521 households in Korea. As the residential electricity demand function provides us information on the pattern of consumer's electricity consumption, it can be usefully utilized in predicting the impact of policy variables such as electricity price and forecasting electricity demands. We apply least absolute deviation(LAD) estimation as a robust approach to estimating parameters. The results showed that price and income elasticities are -0.68 and 0.14 respectively, and statistically significant at the 10% levels. The price and income elasticities portray that residential electricity is price- and income-inelastic. This implies that the residential electricity is indispensable goods to human-being's life, thus the residential electricity demand would not be promptly adjusted to responding to price and/or income change.

• The Journal of the Korea institute of electronic communication sciences
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• v.12 no.2
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• pp.255-260
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• 2017

In Korea, traffic accidents between pedestrians and vehicles in 2015 account for 38.8% of all accidents. This study proposes a system design that can measure the risk of conflict between a vehicle and a pedestrian. Firstly the systemdetect and estimate the position, speed, and directional data of the vehicle and the pedestrian. And then it estimate the conflict point between a vehicle and a pedestrian. The risk of conflict is quantified by estimating the pedestrian safety margin (PSM), which is the time difference between the arrival of the pedestrian at the crossing point to the point of conflict and the vehicle approaching the point. In this system each data is acquired through an external monitoring based evaluation module and an individual wearing module. In the future, such a system can be used for decision making such as the design of road hazard improvement facilities and the designation of the elderly protection area.

• Journal of Digital Convergence
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• v.11 no.10
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• pp.557-569
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• 2013

This study was conducted to identify factors related to subjective happiness Index and by analyzing students, health behavior, smart phone addiction, suicidal Ideation, and in order to develop appropriate measure tp prevent suicide among university students. Methods: From November 19, 2012 until December 14, 2012, 300 college students from one of the iniversities located at K city were surveyed. Data were analyzed using with SPSS window 18.0. Results: The mean score for college students' subjective happiness Index was 4.58 on a scale of 7. There were significant differences on the Subjective happiness Index for the following areas: sex, parental survival & living and household monthly income. There was a negative correlation among the subjective happiness Index, smart phone addiction, suicidal Ideation. Conclusion: Results indicate that factors influencing Subjective happiness are smart phone addiction, suicidal ideation. We suggest that need to establish policies providing family support, smartphone addiction prevention program suicide prevention program to improve a level of happiness.

• Journal of Korean Society of Transportation
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• v.30 no.1
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• pp.103-112
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• 2012

This research introduces a trip generation model reflecting time-series effects derived from a panel analysis with the data collected from the national household trip surveys conducted in 1996, 2002 and 2006. The existing methods are unable to reflect time-series effects from the change of socioeconomic conditions because the parameters applied to the model were basically from the base year of study - the parameter values were unchanged. This study proposes a new trip generation model developed through a panel analysis performed with the data collected from the last three national household trip surveys. From the results, it was found that the number of school trips increases and that the number of shopping trips decreases as time passes. The results showed that there are time-series effects affecting in trip generation.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.7 no.2
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• pp.26-36
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• 2008

Currently, the pedestrian signal timing model has no consideration on the characteristics of different land use patterns and pedestrian behaviors during pedestrian signal timing calculation. This study intended to propose pedestrian signal timing models that could reflect the inherent characteristics of pedestrian and land use patterns. For this study, three major variables affecting the length of signal timing were identified: walking speed, perception-reaction time, and density-delay time. Then, the representative values of each variable were estimated through the field studies. By combining this information, several pedestrian signal timing models were developed. The data in this paper can be used for future references, and the walking environments for pedestrians could be improved by applying the models suggested in this paper.