• Journal of Korean Society for Atmospheric Environment
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• v.21 no.6
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• pp.649-655
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• 2005

Automotive exhaust is suspected to be one of the main reasons of the rapid increase in greenhouse effect gases in ambient air. Although methane emissions are generally orders of magnitude lower than emissions of $CO_{2}$, the global warming potential (GWP) of methane is greater than that of $CO_{2}$. The environmental impact of methane emissions from vehicles is negligible and is likely to remain so for the foreseeable future. In this study, in order to investigate greenhouse gas emission characteristics from gasoline passenger cars, 20 vehicles were tested on the chassis dynamometer and methane emissions were measured. The emission characteristics by model year, mileage, vehicle speed were discussed. Test mode is CVS-15 mode that have been used to regulate for light-duty vehicle in Korea. It was found that $CH_{4}$ emissions showed higher for cold start, old model year and long mileage than hot start, new model year and short mileage, respectively. These results were compared with IPCC emission factors and the overall our results were anticipated to contribute for domestic greenhouse gas emissions calculation.

• Proceedings of the KSR Conference
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• 2008.06a
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• pp.2448-2454
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• 2008

Urban areas face congestion problems that diminish personal mobility and freight-transportation productivity. An increasing number of experts suggest that separating freight traffic from passenger traffic makes sense in terms of economics, the environment, and safety. Some experts suggest that underground freight transportation are the solution. The objective of this paper is to review the potential benefits and limitations of freight pipelines as a viable mode of cargo transport that can alleviate congestion on urban highways.

• Journal of Korean Society of Transportation
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• v.7 no.2
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• pp.45-52
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• 1989

The network equilibrium theory is to estimate the travel choices on a transportation network when the resulting travel times and costs are one basis for the choices. Increasing use of this principle on travel assignment problem lead to develop the combined choice models including not only travel options such as mode and route, but location options like trip distribution problems. This paper, first, reviews earlier developments of variable demand network equilibrium models, combined modeles of trip distribution and assignment, and entropy constrained combined models. Then various model structures of combining travel choice models based on network equilibrium theory and entropy constraints are discussed.

• Journal of Korean Society of Transportation
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• v.32 no.3
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• pp.187-197
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• 2014

The objective of this study is to analyze the travel behaviors of customers accessing to three different types of shopping facilities - traditional markets(TM), hyper markets(HM), and super supermarkets(SSM) - and also to find out the most desirable location for each type of shopping facilities that encourage sustainable transportation and smart urban growth. It also demonstrates what mode has the highest percentage of modal split and what is the access distance for public transport mode by each shopping facilities (SSM: 84.5% walking and 667m, TM: 20.1% bus and 1.6km, HM : 46.2% private car and 4.2km). Among TM, HM, and SSM, statistically significant differences are found in terms of mode choices and other associated travel behaviors. The research findings are expected to contribute to finding future urban planning and transportation solutions that promote walking and public transit uses for shopping trips and thus help support green transportation and sustainable urban growth.

• Journal of Korean Society of Transportation
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• v.22 no.2 s.73
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• pp.77-86
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• 2004

In this study, we applied the Bayesian Network for the case of the mode choice models using the Seoul metropolitan area's house trip survey Data. Sex and age were used lot the independent variables for the explanation or the mode choice, and the relationships between the mode choice and the travellers' social characteristics were identified by the Bayesian Network. Furthermore, trip and mode's characteristics such as time and fare were also used for independent variables and the mode choice models were developed. It was found that the Bayesian Network were useful tool to overcome the problems which were in the traditional mode choice models. In particular, the various transport policies could be evaluated in the very short time by the established relation-ships. It is expected that the Bayesian Network will be utilized as the important tools for the transport analysis.

• Journal of Korean Society of Transportation
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• v.28 no.4
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• pp.119-128
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• 2010

Mode choice behavior is associated with travelers' latent behavior that is an unobservable preference to travel behavior or mode characteristics. This paper specifically addresses the problem of unobservable factors, that is latent behavior, in mode choice models. Consideration of latent behavior in mode choice models reduces the errors that come from unobservable factors. In this study, the authors defined the latent variables that mean a quantitative latent behavior factors, and developed the combined RP/SP model with latent variables using the mode choice behavior survey data. The data has traveler's revealed preference of existent modes along the Han River and stated preference of new water transit on the Han River. Also, The data has travelers' latent behavior. Latent variables were defined by factor analysis using the latent behaviour data. In conclusion, it is significant that the relationship between traveler's latent behavior and mode choice behavior. In addition, the goodness-of-fit of the mode choice models with latent variables are better than the model without latent variables.

• Korean Management Science Review
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• v.16 no.1
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• pp.51-61
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• 1999

Pipeline is an important transportation mode for ail products. The popeline transportation and storage rates affect the popeline usage, and the popeline usage also affects the transportation revenue and operating costs of the popeline. The purpose of our study is to develop a decision support system simulating popeline transportation and storage rates for maximizing the utilization and profitability of the oil pipeline and apply it to the real situation. To do this, a simulation model to help the decision maker decide the rates of the oil pipeline is first proposed. Second, a simulation program is developed, which enables the user to evaluate the various scenarios of oil transportation and storage rates. Finally, this program is applied to the case study of oil industry in korea.

• Journal of Industrial Technology
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• v.29 no.A
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• pp.183-190
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• 2009

This study deals with the single-product production and transportation model with dynamic demand over finite time horizon, in which the optimal production(order) quantities, transportation modes and the number of each vehicles are determined simultaneously. The finite number of identical vehicles with capacity constraint is given to each mode. Production and transportation costs are assumed to be concave function for generality. For a relevant mathematical model formulated, the theorems and properties are discussed to present the efficient algorithm. A numerical example is solved to illustrate the algorithm developed.

• Journal of Institute of Control, Robotics and Systems
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• v.14 no.1
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• pp.7-12
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• 2008

A GNSS(Global Navigation Satellite System) using GPS provides us with very useful information concerning the positioning of users in many sectors such as transportation, social services, the justice system and customs services, public works, search and rescue systems and leisure. A GNSS using the Galileo satellite is due to work in 2008 and expected to be used in various fields such as aviation, marine transportation, land surveying, resources development precise agriculture, telemetics, and so on. In this paper, we discuss the implementation and testing of a combined GPS/Galileo receiver which we named KSTAR V1.0. Each tracking module of GPS/Galileo dual mode correlator has the five track arms which consist of Very Early code, Early code, Prompt code, late code, and Very late code. Each of 24 tracking modules can be assigned to GPS and/or Galileo signal by changing mode selection register. The basic correlator integration dump period is set to 1ms for GPS C/A code and fast Galileo signal tracking. The performance of the developed combined GPS/Galileo receiver was tested and evaluated using the IF (Intermediated Frequency)-level GPS/Galileo signal generator.

• Proceedings of the Korea Port Economic Association Conference
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• 2006.08a
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• pp.103-124
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• 2006

This paper is concerned with a comparative study on the economic effects upon the Korean economy by transport mode, ie road, rail, air, and coastal and inland water transportation between 1990 and 2000, using input-output analysis. The economic effects consist of backward and forward linkage effects, production inducing and import-inducing effects. The data employed for this study come from the Bank of Korea database for Input-Output structure of the Korean economy. The major findings in this study are, among others:(1) the power of dispersion(=backward linkage effect) of coastal and inland water transportation sector is the highest among the four transport sectors, while road cargo transport mode showed the highest the degree of sensitivity (=forward linkage effect); (2) rail cargo transport recorded the highest production inducing effects; and (3) air transport mode achieved the highest ranking in the import-inducing effects.