• Journal of Korean Society of Transportation
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• v.23 no.2
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• pp.25-36
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• 2005

In this study, we suggested a new approach method forecasting distribution demand of urban rail transit usign fuzzy control, with intend to reflect irregularity and various functional relationship between trip length and distribution demand. To establish fuzzy control model and test this model, the actual trip volume(production, attraction and distribution volume) and trip length (space distance between a departure and arrival station) of Daegu subway line 1 were used. Firstly, usign these data we established a fuzzy control model, nd the estimation accuracy of the model was examined and compared with that of generalized gravity model. The results showed that the fuzzy control model was superior to gravity model in accuracy of estimation. Therefore, wwe found that fuzzy control was able to be applied as a effective method to predict the distribution demand of urban rail transit. Finally, to increase the estimation precision of the model, we expect studies that define membership functions and set up fuzzy rules organized with neural networks.

• Journal of Korean Society of Transportation
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• v.31 no.3
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• pp.33-44
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• 2013

Personal Rapid Transit(PRT) has emerged as a promising transportation mode for transit-oriented sustainable communities. In this study, an alternative design of questionnaire survey is proposed in order to capture traveler's perception of an unexperienced transportation mode. This study aims at predicting the mode choice diversion behavior of potential PRT users who do not have experience of using it previously, considering their willingness-to-pay. The proposed model was applied to predict an aggregate forecast of PRT patronage for the city of Songdo where PRT is considered to be constructed. For validation of the proposed model, the price elasticity of PRT demand was analyzed, compared with existing models. The analysis results suggest that the proposed design of questionnaire survey is able to capture respondents' attitude and perception to unexperienced transportation mode in an effective manner. Also, they show that the proposed diversion rate model is more realistic than existing models in explaining the effects of users' willingness-to-pay for predicting PRT patronage.

• Journal of Distribution Science
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• v.13 no.10
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• pp.123-133
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• 2015

Purpose - The Korean government has devised intermodal transportation policies and granted subsidies to shippers and logistics companies that made a conversion of transportation means through the policies. This provides support by expanding the complex uniform railroad transportation and overhauling the deteriorated railroad facilities. As for 2013, however, the freight transportation percentage of railroad was 4.5% in tons and 8.5% in ton kilometers. Meanwhile, since the 1990s, developed countries such as the U.S. and Europe have been trying to expand intermodal freight transport with a legal and institutional support to build a logistics system corresponding with social and economic environmental changes. In this study, I set out to examine the effects of the intermodal freight transport policies in the EU and the U.S., and to explore the direction of setting up a rail intermodal transport system in South Korea. Research design, data, and methodology - The paper used a qualitative research methodology through the literature review. First, was an overview of Intermodal transportation in the EU, U.S. and UN. Second, it describes the development of transport in Europe and the U.S. with particular emphasis on intermodal freight transport. Third, it explores the direction of setting up a intermodal freight transport in South Korea. The last section contains concluding remarks. Results - As for the EU, it has been promoting integration between transport and intermodal logistics network designs while utilizing ITS or ICT and supports for rail freight intermodal by giving reduction to a facilities fee or subsidizing for rail freight in order to minimize the cost of external due to freight transport. On the other hand, as for the U.S., it has been made up of an industrial-led operating project and has been promoting it to improve accessibility between intermodal hubs and cargo terminals through intermodal corridor program, and an intermodal cargo hub access corridor projects, etc. Moreover, it has tried to construct intermodal transport system using ITS or ICT and to remove Barrier. As a result, in these countries, the proportion of intermodal freight transport is going to be the second significant transport compared with rail and maritime transport. An Effective rail intermodal transport system is needed in South Korea, as seen in the case of these countries. In order to achieve this object, the following points are required to establish radical infrastructure policy; diversify investment financing measures taken under public-private partnerships, legal responsibilities, improvement of utilization of existing facilities to connect the railway terminal and truck terminal, and enhancement service competitiveness through providing cargo tracking and security information that combines the ITS and ICT. Conclusions - This study will be used as a basis for policy and support for intermodal freight transport in South Korea. In the future, it is also necessary to examine from the perspective of the shipper companies using the rail intermodal transport, ie, recognition of shipper, needed institutional supports, and transportation demand forecasting and cost-effective analysis of the railway infrastructure systems improvement.

• Journal of Korean Society of Transportation
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• v.32 no.5
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• pp.544-553
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• 2014

Activity-based models analyze individuals' various daily activities that are identified as a decision-making unit for transportation planning. In other words, it is the model that determines the types of activities according to the social, economic and situational characteristics of the groups with the same activity patterns and predicts individuals' activity time, distance, spatial movement and transportation mode. The activity-based model is a method of estimating more efficient and realistic demand in transportation forecasting because traffic is regarded as a complex decision-making process that an individual and other people participate in. In this paper, we grasp the factors affecting choice behavior of activity pattern and analyze choice behavior of activity pattern based on multi-dimensional characteristic of each person. First, we classify activity types of reviewing the trip chain and activity purpose. Next, we identified preferable activity types using complicated characteristics of main agent of activity. We concluded that choice behavior of activity pattern is dependent on complex characteristics of each agent, and further multi-dimensional characteristics of each person are affected over the whole decision process of activity schedule.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.6 no.2
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• pp.45-55
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• 1986

This study proposes the explanatory indices of urban traffic for the purpose of solving the ambiguity of selection of the explanatory variables, which always raises problems in case of the travel-demand forecasting in the urban transportation planning, and develops optimal urban traffic generation models. The multiple regression models for objective traffic generation are developed by using the proposed explanatory inidces. Objective variables that can be explained by one explanatory variable are modified into simple regression type (Y=bX) in order to ensure the nonnegativity of traffic generation. Similarities are noted in the generaton characteristics of generated traffic from homogeneous land-use activity. Objective variables that can not be explained by multiple variable, such as trip attraction of school and trip generation of social-recreation, are classified by the characteristics of each zone. And traffic generation forecasting models are built as homogeneous zone group, the validity of each model being tested by a statistical method. It is desired that the forecasting precision is in improved by easy and simple method. Accordingly, trip generation rates are calculated from each land-use activity, and trip generation rates for practical application are proposed by considering their stability.

• Journal of Korean Society of Transportation
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• v.31 no.5
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• pp.37-47
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• 2013

This Study analyzed the electric car effect on the Korea Expressway System in terms of year 2020 $CO_2$ emission. The analysis was based on the green car dissemination goal by the government and year 2010 emission statistics. Major contents performed in the study area were as follows. First, the greenhouse gases emitted from the highways were found to be approximately 17.3 million tons of $CO_2$ as of 2010. Analysis showed the emission would be 17.4 million tons in 2015 and 16.2 million tons in 2020. The results in the pattern reflect the effect of O/D on the KTBD and the trend of traffic increase from 2015 to 2020 followed by decrease in 2020. Second, in the case of greenhouse gas emission with the anticipated supply of electric cars, the amount of emission in 2015 will be 17.1 million tons, which is about 2.0% reduction compared to the lack of introduction of electric cars. The analysis also showed that in 2020, the amount of emission will be 14.2 million tons, which indicates the effect of reduction is 12.8% compared to non implementation of the program.

• Journal of Korean Society of Transportation
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• v.32 no.5
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• pp.531-543
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• 2014

Research on activity-based travel demand forecasting and activity-travel simulator has received an international attention for the last two decades. Ways to develop the activity-based simulator may be manifold. It is obvious that importing an existing simulator that has been proven internationally likely reduces the development cost and the risk of failure. By definition of the activity-based approach, however, the details of an activity-based simulator inevitably relies on particular social, economic and cultural characteristics of the society where the simulator is developed. When importing such a simulator from overseas, the researcher should be aware of the importance of tuning the system for the society to which the imported system is applied. There are many potential works on this, including for example the tuning of data structure that is likely different form of the original system. The authors are yet aware of certain research on those. The current paper aims to report the result of transforming the input data for applying the existing activity-travel simulator to Seoul. The paper first introduces FEATHERS that was developed in Belgium having Albatross which is the core of system. FEATHERS Seoul that is under development and modified version of the original FEATHERS is briefly described and the related problems are discussed. The paper then explored to resolve and to alleviate such problems.

• Journal of Navigation and Port Research
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• v.34 no.7
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• pp.587-594
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• 2010

The positive and negative opinion to cargo demand of Incheon's SAMT in the near future remains cloudy. Considering port and shipping environmental changes and the logistics situation of China which explains the lack of facilities in Chinese airports, the creating of SAMT cargoes of the Incheon region could catches a favorable opportunity to be a logistics hub in the North-East Asia. On the other hand, as open-sky policy and direct-call service has been carried out between China and N.A.(North America), Incheon could cause a loss of competitiveness in SAMT because the enhancement in the aspect of the connectivity of Chinese airlines and shipping lines makes customer sent to last destination their cargoes whenever they want. In the same context, this paper analyses on conditions of domestic and international SAMT and proposes in this uncertainty future forecasting of SAMT of Incheon by scenario planning according to changes in integrated SAMT, measuring the likelihood of final scenario. This study shows the Sea & Air multi-transport volume will have either slight increase or decrease from the current condition. Consequently, RFS expansion and system & service improvement through strong ties with major cities in China will be required in a short run aspect. Nonetheless, we also need to take domestic & international transportation environment into account in the long run.

• Journal of Navigation and Port Research
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• v.46 no.5
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• pp.449-457
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• 2022

The Port of Busan is currently ranked as the seventh largest container port worldwide in terms of cargo throughput. However, port competition in the Far-East region is fierce. The growth rate of container throughput handled by the port of Busan has recently slowed down. In this study, we analyzed how economic conditions and multiple external shocks could influence cargo throughput and identified potential implications for port business. The aim of this study was to build a model to accurately forecast port throughput using the ARIMA model, which could incorporate external socio-economic shocks, and the VEC model considering causal variables having long-term effects on transshipment cargo. Findings of this study suggest that there are three main areas affecting container throughput in the port of Busan, namely the Russia-Ukraine war, the increased competition for transshipment cargo of Chinese ports, and the weaker growth rate of the Korean economy. Based on the forecast, in order for the Port of the Port of Busan to continue to grow as a logistics hub in Northeast-Asia, policy intervention is necessary to diversify the demand for transshipment cargo and maximize benefits of planned infrastructural investments.

• Journal of Korean Society of Transportation
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• v.22 no.5
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• pp.89-97
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• 2004

The Korea Air Force(KAF) has operated freight flights based on the prefixed time and route schedule, which is adjusted once in a month. The major purpose of the operation of freight flights in the KAF is to distribute necessary supplies from the home air base to other air bases. The secondary purpose is to train the young pilots to get more experiences in navigation. Each freight flight starts from and returned to the home air base everyday except holidays, while it visits several other air bases to accomplish its missions. The study aims to forecast freight demand at each base by using time series analysis, and then it tried to optimize the cost of operating flights by solving vehicle routing problem. For more specifically, first, several constraints in operating cargos were defined by reviewing the Korea Air Force manuals and regulation. With such constraints, an integer programming problem was formulated for this specific routing problem allowing several visits in a tour with limitation of maximum number of visits. Then, an algorithm to solve the routing problem was developed. Second, the time series analysis method was applied to find out the freight demand at each air base from the mother air base in the next month. With the forecasted demands and the developed solution algorithm, the oprimum routes are calculated for each flight. Finally, the study compared the solved routing system by the developed algorithm with the existing routing system of the Korea Air Force. Through this comparison, the study proved that the proposed method can provide more (economically) efficient routing system than the existing system in terms of computing and monetary cost. In summary, the study suggested objective criteria for air routing plan in the KAF. It also developed the methods which could forecast properly the freight demands at each bases by using time series analysis and which could find the optimum routing which minimizes number of cargo needed. Finally, the study showed the economical savings with the optimized routing system by using real case example.