• Journal of Environmental Impact Assessment
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• v.16 no.6
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• pp.485-494
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• 2007

Air pollution and traffic noise from roads distributed near residential area has been a major social problem. In this study, an environmental pollution map for a residential area of Shihung-city was made by an expectation model based on hourly traffic volume change. Using the result from the model, a plan to reduce population in the residential area was established. The result of the modelling is summarized as follows: 1. At peak traffic hours (18 o'clock), 301-500 degree in hazardous and $d_{25}$ degree (25% of the residents are suffering extremely from the noise) in noise pollution were predicted in Jeongwang Main Road in Shihung city. 2. The calculated critical pollutant standard index, PSI showed the air pollution level, especially PM-10 high enough to require re-entrainment. 3. It was expected air pollution would extensively extend over the area distribution of each degree. However, noise pollution problem was limited to the area near roads.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.23 no.2
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• pp.119-131
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• 2024

Understanding accurate traffic performance is crucial for ensuring efficient highway operation and providing a sustainable mobility environment. On the other hand, an immediate and precise estimation of highway traffic performance faces challenges because of infrastructure and technological constraints, data processing complexities, and limitations in using integrated big data. This paper introduces a framework for estimating traffic performance by analyzing real-time data sourced from toll collection systems and dedicated short-range communications used on highways. In particular, this study addresses the data errors arising from segmented information in data, influencing the individual travel trajectories of vehicles and establishing a more reliable Origin-Destination (OD) framework. The study revealed the necessity of trip linkage for accurate estimations when consecutive segments of individual vehicle travel within the OD occur within a 20-minute window. By linking these trip ODs, the daily average highway traffic performance for South Korea was estimated to be248,624 thousand vehicle kilometers per day. This value shows an increase of approximately 458 thousand vehicle kilometers per day compared to the 248,166 thousand vehicle kilometers per day reported in the highway operations manual. This outcome highlights the potential for supplementing previously omitted traffic performance data through the methodology proposed in this study.

• Journal of the Korean association of regional geographers
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• v.21 no.1
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• pp.62-78
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• 2015

This paper aims to consider regional linkages in the Province of Young-nam mainly through a social network analysis of sociocultural activities such as leisure, friendly relations and visiting relatives. Passenger O-D data as of 2012 provided by National Transportation DB Center are analyzed using the NetMiner 4.0. The analytical results show that the sociocultural relationship between Daegu-Kyoungbuk and Busan-Ulsan-Kyioungnam is not so close. In particular, some north regions of Kyoungbuk are relatively isolated in the Province of Young-nam. This implicates that regions in the Province of Young-nam are not closely united at least in terms of sociocultural linkages although they are in the homogeneous natural environment of the basin of the Nakdong-river and share a same historical background for a long time. Consequentially this work suggests the Province of Young-nam may not be an united single region on the contrary to a notion of it so far.

• Journal of Korean Society of Transportation
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• v.32 no.4
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• pp.347-356
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• 2014

Passenger cars occupy about 74% among registered vehicles in Korea and the ratio of transportation mode sharing is approximately 60% in the passenger transport part. However, there is no statistics related to travel characteristics of passenger cars, and official statistics are estimated from O/D travel data. Thus, National Transportation DataBase Center in KOTI has attempted to construct various statistical data through Korea Vehicle Use Survey. Based on these data, Analysis of Variance (ANOVA) was conducted to investigate the differences in travel characteristics of each analysis group. As a result, all of the explanatory variables(weekday vs. weekend, metropolitan area vs. non-metropolitan area, male vs. female, commute time vs. other time, routine purpose vs. non-routine purpose) were found to be different across households. In addition, travel distances per trip of weekday, metropolitan area, male, commute time, and non-routine purpose are longer than the opposite variables. Also, the trip distances of small size(1 to 2 persons) households are shorter compared to large size(more than 5 persons) households.

• Journal of Korean Society of Transportation
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• v.31 no.2
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• pp.60-68
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• 2013

This study developed plural gravity models and their application method in order to increase the accuracy of trip distribution estimation. The developed method initially involves utilizing the coefficient of determination ($R^2$) to set the target level. Afterwards, the gravity model is created, and if the gravity model's coefficient of determination is satisfactory in regards to the target level, the model creation is complete and future trip distribution estimation is calculated. If the coefficient of determination is not on par with the target level, the zone pair with the largest standardized residual is removed from the model until the target level is obtained. In respect to the model, the removed zone pairs are divided into positive(+) and negative(-) sides. In each of these sides, gravity models are made until the target level is reached. If there are no more zone pairs to remove, the model making process concludes, and future trip distribution estimation is calculated. The newly developed plural gravity model and application method was adopted for 42 zone pairs as a case study. The existing method of utilizing only one gravity model exhibited a coefficient of determination value ($R^2$) of 51.3%, however, the newly developed method produced three gravity models, and exhibited a coefficient of determination value ($R^2$) of over 90%. Also, the accuracy of the future trip distribution estimation was found to be higher than the existing method.

• Journal of Korean Society of Transportation
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• v.33 no.4
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• pp.393-404
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• 2015

Gravity model has had the major problem that the model explains the characteristics of travel behavior with only deterrence factors such as travel time or cost. In modern society, travel behavior can be affected not only deterrence factors but also zonal characteristics or transportation service. Therefore, those features have to be considered to estimate the future travel demand accurately. In this regard, there are two primary aims of this study: 1. to identify the characteristics of inter-zonal travel, 2. to develop the new type of calibration method. By employing accessibility variable which can explain the manifold pattern of trip, we define the zonal travel behavior newly. Furthermore, we suggest 2-phase calibration method, since existing calibration method cannot find the optimum solution when organizing the deterrence function with the new variables. The new method proceeds with 2 steps; step 1.estimating deterrence parameter, step 2. finding balancing factors. The validation results with RMSE, E-norm, C.R show that this study model explains the inter-zonal travel pattern adequately and estimate the O/D pairs precisely than existing gravity model. Especially, the problem with estimation of short distance trip is overcomed. In conclusion, it is possible to draw the conclusion that this study suggests the possibility of improvement for trip distribution model.

• Journal of the korean Society of Automotive Engineers
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• v.5 no.3
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• pp.8-15
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• 1983

1960년초 이래 우리나라는 고도의 경제성장을 이룩하게 되었으며 이러한 경제성장에 따른 산업화 사회의 특징인 공업화 도시화 인구집중 현상은 우리나라에도 심각한 환경오염 문제를 야기시켜 왔다. 또한 같은 기간동안 자동차의 보유대수 역시 급격한 증가를 보여왔던바, 1962년 30,000 대에서 1982년도 자동차 등록대수는 약 640,000대로 증가하게 되었으며 대부분의 자동차가 대 도시에 집중되어 있다. 특히 전체 차량의 40%가 집중되어 있는 서울시의 경우에는 자동차 배 출가스로 인한 대기오염문제가 도시민의 건강과 재산에 많은 피해를 일으키게 되었다. 우리나 라는 선진 외국의 대도시에 비해 자동차의 1일 주행거리가 3배 내지 5배를 더 주행하고 있고 자동차 배출가스 기준의 완화, 노후차량의 증가, 도로율의 불황 및 도로조건의 불비 등은 도시 중심천의 자동차 집중현상과 함께 자동차 배출가스로 인한 대기오염 문제가 보다 더 심각하게 우려되었고, 따라서 자동차 배출가스규제 강화의 필연성이 계속해서 주장되어 왔다. 자동차로 인한 공해문제는 1940년도 후반 미국 남부 California 지방에서 광화학스모그의 발생과 함께 거 론되기 시작하였으나 본격적으로 문제가 제기된 것은 급격한 자동차 증가로 인한 도시민의 건 강피해가 발생하기 시작한 것은 1960년대이다. 처음으로 규제되기 시작한 것은 1965년 미국에서 "자동차 오염방지법"의 제정부터이며 1968년부터 자동차 배출가스에 대한 규제가 시작되었다. 한편 일본은 1973년, 유럽에서는 1975년부터 일산화탄소, 탄화수소, 질소산화물 및 매연에 대한 규제를 시작하게 되었다. 우리나라에서는 "도로운송차량법"에서 도로교통의 안전과 질서유지라는 측면에서 일부 규제하여 오다가 1977년말 "환경보전법"이 제정 공포되면서 1980년 1월 환경정의 발족과 함께 실제로 자동차 배출가스를 규제하게 되었다.발족과 함께 실제로 자동차 배출가스를 규제하게 되었다.을 SUP7H종으로 더욱 향상된 것이 실용 화되고 있다. 아래에서 이에 대한 기계적 특성을 중심으로 검토키로 한다.9%내인 0.07cm 정도였으나 1973년과 1974년의 방축년에는 조차 3개 처리구(3.4-5.18cm)에 필적되는 연평균 4.16cm로 나타났다. 5. 전체 시험구로부터으 연평균 토양유실량은 Sharpsburg 점질양토에 대한 S.C.S 한계허용치 10ton/ha/year 이내로 나타났다. 비처리구에서의 토양유실량은 평균 2.56ton/ha/year로 높게 나타난 반면 3개의 서로 다른 추리구인 비수구, 초생수로구 및 Bromegrass구에서는 각각 0.152, 0.192 및 0.290ton/ha/year로 낮은 결과를 가져왔다. 6. 평균 침전량에 대한 L.S.D. 검정 걸과 전시험구중 비처리구가 고도의 유의차를 나타낸 반면 비수구, 초생수로구 및 Bromegrass 목초구 간에는 아무런 유의차가 인정되지 않았다. 7. 농지보전 처리구인 배수구와 초생수로구는 비처리구에 비해 낮은 침두 유출량과 낮은 토양유실량을 나타내었다.구보다 14% 절감되는 것으로 나타났다.작용하는 것으로 사료된다.된다.정량 분석한 결과이다. 시편의 조성은 33.6 at% U, 66.4 at% O의 결과를 얻었다. 산화물 핵연료의 표면 관찰 및 정량 분석 시험시 시편 표면을 전도성 물질로 증착시키지 않고, Silver Paint 에 시편을 접착하는 방법으로도 만족한 시험 결과를 얻을 수 있었다.째, 회복기 중에 일어나는 입자들의 유입은 자기폭풍의 지속시간을 연장시키는 경향을 보이며 큰 자기폭풍일수록 현저했다. 주상에서 관측된 이러한 특성은 서브스톰 확장기 활동이 자기폭풍의 발달과 밀접한 관계가 있음을 시사한다.se that were all low in two aspects, named "the Nonsignificant group". And the issues were high risk perception in

• Journal of Korean Society of Transportation
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• v.23 no.2
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• pp.117-130
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• 2005

In both deteministic user Optimal Traffic Assignment Model (UOTAM) and stochastic UOTAM, travel time, which is a major ccriterion for traffic loading over transportation network, is defined by the sum of link travel time and turn delay at intersections. In this assignment method, drivers actual route perception processes and choice behaviors, which can become main explanatory factors, are not sufficiently considered: therefore may result in biased traffic loading. Even though there have been some efforts in Stochastic UOTAM for reflecting drivers' route perception cost by assuming cumulative distribution function of link travel time, it has not been fundamental fruitions, but some trials based on the unreasonable assumptions of Probit model of truncated travel time distribution function and Logit model of independency of inter-link congestion. The critical reason why deterministic UOTAM have not been able to reflect route perception cost is that the route perception cost has each different value according to each origin, destination, and path connection the origin and destination. Therefore in order to find the optimum route between OD pair, route enumeration problem that all routes connecting an OD pair must be compared is encountered, and it is the critical reason causing computational failure because uncountable number of path may be enumerated as the scale of transportation network become bigger. The purpose of this study is to propose a method to enable UOTAM to reflect route perception cost without route enumeration between an O-D pair. For this purpose, this study defines a link as a least definition of path. Thus since each link can be treated as a path, in two links searching process of the link label based optimum path algorithm, the route enumeration between OD pair can be reduced the scale of finding optimum path to all links. The computational burden of this method is no more than link label based optimum path algorithm. Each different perception cost is embedded as a quantitative value generated by comparing the sub-path from the origin to the searching link and the searched link.