• Korean Journal of Environment and Ecology
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• v.28 no.1
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• pp.90-98
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• 2014

This study was carried out to provide basic data. his research conducted the survey using face to face survey and board survey during about 2 months from Oct. to Nov. in 2009 for users of Bongje Mt., a small-sized mountain at downtown, and Acha Mt., a big-sized mountain at outskirt so as to compare the differences of using behavior by forms and size of urban forest in living area of Seoul. Characteristics of urban forest users, using behavior, demands and satisfaction of facilities and management and pass pattern were set as research items. The thing in common for using behavior is that both genders of main users were in more than 40s~60s. They showed the highest using rate from 7 a.m. to 12 p.m. and high rate for using nearly everyday or visiting two or three times per a week. In addition, it's judged that the accessibility from dwelling area to entrance of urban forest in living area is good and satisfaction for the standard of facilities and their management in forest way was relatively low. For the complement and essential facilities, 'sanitary facilities' showed the highest rate. For the differences of using behavior, most of Bongje Mt. users were residents living within a 2km radius (under the standard of walking) and they moved by average 1.3km. And, they preferred short-time activities of about 24 minutes. On the other hand, main users of Acha Mt. were residents living within a 4km radius (under the standard of walking) and people of other regions. and 60% of them preferred the passage route taking 3hours half over 6km. Through the survey on using behavior of urban forest in living area of Seoul, with different using form and forest size, introduction of using program for main users or managing method of differentiations for introduced facility's management should be properly applied. Especially, urban forest should be systematically managed like park green as expected that residents's using of urban forest will be increased with the increase of leisure time.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.1
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• pp.297-304
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• 2013

Due to its excessive $CO_2$ emissions, road transport sector becomes a target for emission reduction strategies. Although precise and reliable emissions inventories are necessary for evaluating plans and strategies, developing the region-wide inventory is a difficult task mainly because of a lack of data including travel patterns and modal volumes in the reginonal context. Most existing inventory methodologies employ fuel sale data within the target region, which ignores actual regional traffic patterns and thus not suited to its geographical context. To overcome these problems, this study develops region-wide $CO_2$ emissions inventory methodology by utilizing the Korea Transport DB (KTDB). KTDB provides a number of useful information and data, such as road network with which one can identify in and out trips over the entire region, traffic volumes of various modes, distance of travel, travel speed and so on. A model of equations that allow the computation of volume of $CO_2$ emitting from the road transport activities within the target region is developed. Using the model, numerical analyses are performed for the case of Busan Metropolitan City to demonstrate the applicability of the developed model. This study is indeed exploratory in the sense that using the existing data, it develops the $CO_2$ emissions inventory methodology which can produce better results than those from conventional fuel sales methodology. This study also suggests further reresarch directions to develop more refined methodologies in region-wide basis.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.10 no.1
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• pp.112-123
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• 2011

This study focused on developing strategies of cyber-compact city, combining compact city with information and communications technologies(ICTs), in order to enhance sustainable transportation. The cyber-compact city development is defined as a development that is able to reduce travel by ICTs and encourage people to use transit or non-motorized vehicles such as bicycles for ICT-induced travel (especially, discretionary travel) by compact and mixed land use. It can be achieved with combining cyber and compact strategies with respect to network, node, and area. For example, ICT network may use transit network facility, a transfer station may be a hub of ICTs, and transit influenced zone may work with ICT service area. We proposed three cohesive strategies for the cyber-compact city based on literature review and case studies on cyber and compact cities. The first strategy is a cohesion between public transportation and telecommunication network by centering on the two for national and urban spatial linkage structure. That is, cities or urban centers and its peripheral areas can be connected by rail network, and extra space of railway network can be used for constructing telecommunication network infrastructure. The second strategy is a cohesion between public transportation node and telecommunication node by building up regional and urban telecommunication centers near to or at main railway stations. For this strategy, telework centers and communication service centers should be established mainly at transfer stations. The third strategy is a cohesion between public transportation impact zone and telecommunication impact zone as transit oriented development.

• Journal of Korean Society of Transportation
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• v.32 no.1
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• pp.1-12
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• 2014

The tier 3 methodology used in estimation of greenhouse gas emissions from road sectors is based on mileage data. However, such data can neither accurately represent the mileage of regional unit nor have sufficient integrated data reflecting the characteristics by region, vehicle type, fuel type and road type. Such estimation of greenhouse gas emissions is not reliable. Accordingly, the purpose of this study is, firstly to accumulate activity data based on distance traveled which enables us to accurately estimate the amount of green gas emitted by regional unit(emission point), and secondly, to develop a methodology for estimation of greenhouse gas emissions using these data. To do this, the study utilizes the mileage data of Korea Transportation Safety Authority(TS), statistics of registered motor vehicles, statistical yearbook of traffic volume from the Ministry of Land, Infrastructure and Transport(MLIT), the Korea Transport Database of the Korea Transport Institute(KOTI), and average road speed by local government. Methodology for estimation by local government level(emission point) is meaningful, because it reflects traffic pattern data including flow in and out and internal traffics. Finally, to verify the methodology presented in this study, it is applied to Seoul. Both greenhouse gas estimates, one by multiplying the average mileage and the number of registered vehicles and the other by multiplying traffic volume and road extension, are less than the amount estimated by the methodology presented in this study.

• The Korean Journal of Malacology
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• v.30 no.4
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• pp.421-428
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• 2014

Total 20 surface sediments were collected in Anjung bay to investigate the physicochemical environment and heavy metal contents. The physicochemical investigation ranged from 6.41% to 11.68% (average $9.52{\pm}1.28%$) for ignition loss (IL), from 17.99 mg/g to 43.84 mg/g (average $27.53{\pm}6.39mg/g$) for chemical oxygen demand (COD), and from 0.05 mg/g to 0.61 mg/g (average $0.17{\pm}0.14mg/g$) for acid volatile sulfide (AVS) with significant correlation between water content (W/C) and COD. A contour of spatial distribution indicated higher organic pollution at the bottom of ascidian, Stylea clava, cultural waters. Most of metals contents was not exceeded the NOAA's effect range-low (ERL). Estimated enrichment factor (EF) ranging 0.96-1.12 indicated that the sediment environment of the studied waters was relatively pristine from heavy metal pollution in spite of increased vessel traffics, so far.

• Journal of Korean Society of Transportation
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• v.32 no.2
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• pp.93-105
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• 2014

This study evaluated the relative efficiency of mobile emission reduction countermeasures through a Data Envelopment Analysis (DEA) approach and determined the priority of countermeasures based on the efficiency. Ten countermeasures currently applied for reducing greenhouse gases and air pollution materials were selected to make a scenario for evaluation. The reduction volumes of four air pollution materials(CO, HC, NOX, PM) and three greenhouse gases($CO_2$, $CH_4$, $N_2O$) for the year 2027, which is the last target year, were calculated by utilizing both a travel demand forecasting model and variable composite emission factors with respect to future travel patterns. To estimate the relative effectiveness of reduction countermeasures, this study performed a super-efficiency analysis among the Data Envelopment Analysis models. It was found that expanding the participation in self car-free day program was the most superior reduction measurement with 1.879 efficiency points, followed by expansion of exclusive bus lanes and promotion of CNG hybrid bus diffusion. The results of this study do not represent the absolute data for prioritizing reduction countermeasures for mobile greenhouse gases and air pollution materials. However, in terms of presenting the direction for establishing reduction countermeasures, this study may contribute to policy selection for mobile emission reduction measures and the establishment of systematic mid- and long-term reduction measures.

• Journal of Korean Society of Transportation
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• v.36 no.1
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• pp.38-50
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• 2018

Emerging automated driving environments will lead to a mixed traffic flow depending on the interaction between automated vehicles (AVs) and manually driven vehicles (MVs) because the market penetration rate (MPR) of AVs will gradually increase over time. Understanding the characteristics of mixed traffic conditions, and developing a method to control both AV and MV maneuverings smoothly is a backbone of the traffic management in the era of automated driving. To facilitate smooth vehicle interactions, the maneuvering of AVs should be properly determined by various traffic and road conditions, which motivates this study. This study investigated whether the aggressiveness of AV maneuvering, defined as automated driving aggressiveness (ADA), affect the performance of mixed traffic flow. VISSIM microscopic simulation experiments were conducted to derive proper ADAs for satisfying both the traffic safety and the operational efficiency. Traffic conflict rates and average travel speeds were used as indicators for the performance of safety and operations. While conducting simulations, level of service(LOS) and market penetration rate(MPR) of AVs were also taken into considerations. Results implies that an effective guideline to manage the ADA under various traffic and road conditions needs to be developed from the perspective of traffic operations to optimize traffic performances.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.19 no.4
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• pp.30-44
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• 2020

The application of PPLT is difficult to analyze and judge only from the effects of the delay time. In this study, the application of PPLT was proposed using not only the delay time of PLT and PPLT due to the change in traffic volume and the number of opposite straight lanes but also the traffic volume of passing a left turn and the number of conflict risks as indicators. According to the analysis, the more left-turn traffic than capacity and the less opposite-straight volume, the greater the PPLT effect. On the other hand, if the left-turn traffic is below capacity, the delay time will be reduced partially, but the overall passing left turn volume will not increase, and the conflict risk will increase. In addition, the conflict risk increases in the third lane or higher. Moreover, the difference of passing left-turn volume between PLT and PPLT showed a pattern similar to the delay time difference, and the PPLT coverage was wider than the difference in delay time and was associated more with the conflict risk numbers. Therefore, it would be reasonable to use passing left-turn traffic primarily, consider the delay time below the left-turn capacity, and consider the conflicting risk numbers simultaneously at or above the opposite straight three lanes.

• Korean Journal of Environment and Ecology
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• v.1 no.1
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• pp.66-82
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• 1987

The user's composition of socia-economic characteristics in Bukhan Mountain National Park showed that male. twenties and students were 65.4 percent. 62.7 percent and 37.4 percent respectively by sex, age and occupation. In visiting purpose, the nature-oriented motive was 67.1 percent of the total. hut the picnic patterns as of neighbourhood park and the recreation patterns as of recreation ground were appeared simultaneously. In preferable place of visitors. the well-known mountain hut, camp sites and summits were prefered. The level of scenic satisfaction was 7.8 and comparatively high on considering the maximum level of 10.0. The level of total satisfaction. however, was no more than 6.3 owing to lack of accomodation facilities along trails, 63.4 percent of visitors were opposed to construction cable-car and visitors were anxious seriously about the nature deterioration. In Jeongnung valley, the number of users was the lagest, so that the maximum number of passangers a day attained to 20.000. The peak seasons of visiting were Spring and Fall, and the peak hours during a day was 10-11 hours A.M. and 3-5 hours P.M. Therefore partitioned spatial management in consideration of hiking pattern of nature park. picnic pattern as of neighbourhood park and recreation pattern as of recreation ground shall be necessary to solve the conflicts among functions.

• Journal of Korean Society of Transportation
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• v.28 no.1
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• pp.39-49
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• 2010

Although many studies have been carried out on the pattern of behavior of drivers which result from the provision of traffic information, there have been few detailed studies on the composition of message, method for message expression, timing of provision, point of provision, media for provision, changes by traffic condition, etc. This study was intended to provide an insight into the changes in the characteristics related to the provision of information by analyzing how the patterns of information utilization change depending on the traffic condition and reclassifying such patterns according to the characteristics of media. Unlike the existing studies, this study adopted the traffic condition, using rate of information media, and the correlation coefficient label as the basis for information media classification, and categorized them into passive utilization media, active utilization media, and past experience in order to ensure the statistical reasonability. The categorized using rate of information media and traffic condition was found to have a positive(+) correlation with the travel speed in the case of passive utilization media during both consecutive holidays(Korea's traditional Thanksgiving day) and weekends, but had a negative(-) correlation with the positive utilization media and past experience. The rate of decision to take a detour based on the past experience was high at the condition of congestion or slow during both consecutive holidays and weekends, but the rate of decision to take a detour through passive utilization media was high in a smooth traffic. In other words, if the traffic condition worsens, using rate of passive utilization media would be low while the diversion rate would be high which uses the active utilization media and past experience. Therefore, it should be established to suit the traffic condition and media characteristics for strategies of traffic distribution through drivers' diversion behavior on weekends and consecutive holidays.