• Journal of Korean Institute of Industrial Engineers
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• v.35 no.1
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• pp.1-14
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• 2009

The efficiency of transportation requests fulfillment can be increased through extending the problem of vehicle routing and scheduling by the possibility of subcontracting a part of the requests to external carriers. This problem extension transforms the usual vehicle routing and scheduling problems to the more general integrated operational transportation problems. In this contribution, we analyze the motivation, the chances, the realization, and the challenges of the integrated operational planning and report on experiments for extending the plain Vehicle Routing Problem to a corresponding problem combining vehicle routing and request forwarding by means of different sub-contraction types. The extended problem is formalized as a mixed integer linear programming model and solved by a commercial mathematical programming solver. The computational results show tremendous costs savings even for small problem instances by allowing subcontracting. Additionally, the performed experiments for the operational transportation planning are used for an analysis of the decision on the optimal fleet size for own vehicles and regularly hired vehicles.

• Journal of Korean Society of Transportation
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• v.14 no.2
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• pp.31-44
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• 1996

This study focuses on the evaluation of the streets on residential areas. For this purpose, pedestrain and vehicle occupancy indicators on residential areas are proposed, and vehicle, pedestrain flow and status of on-street parking on residential streets are analyzed. Also, according to the suggested occupancy indicator, occupancy status of pedestrain and vehicle are identified. At the end, evaluation of residential streets are conducted. The suggested occupancy indicator is a quantitative indicator which can represent the traffic situation on street. It can also be represente din the same dimension among pedestrain, vehicle flow, packed vehicle. Also, occupancy indicator can be utilized for the allocation and evaluation of transportation modes on residential street. Except on-street parking during the day time, moving vehicle occupancy rate contains the more than 80 precent when it is estimated based on the vehicle flow and pedestrain only. As the streets on residential area are occupied by the pedestrain approximately 20 percent during the day time, it is identified quantitatively that the necessity of space for pedestrain.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2011.06a
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• pp.417-418
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• 2011

Mongolia is an inland country contained between East and Central Asia. I t borders Russia to the north and China to the south, east and west. Mongolia uses as international port for transit Xindang/Qingdao by railway. For domestic transport, our options are varied, which include road, railway and air modes. Mongolia's government enacted some shipping ways to develop logistics around the world. ${\cdots}\;{\cdots}$ (omit).

• Proceedings of the KSR Conference
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• 2008.11b
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• pp.742-749
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• 2008

In 21th century, high oil price and environmental pollution appeared by serious social problem. It brought important change of logistics environment, and environmentally-friendliness and sustainability are emphasized. In spite of that railroad has high energy efficiency and environmental-friendliness to advantage traditionally, there is still transport division rate of railroad in declining tendency as investment policy that is concentrated on road and insufficiency of social realization about environmental problem. The construction of environment-friendly transport system and the reasonable role sharing between modes of transportation are important. Transportation policy of Korea is presented through plans to constructs efficiently and manages national transportation system. In this study, examine development process of national railroad logistics plan with logistics environment change, and proposes the following ways to development of railroad logistics policy.

• Journal of Korean Society for Geospatial Information Science
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• v.3 no.2 s.6
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• pp.199-211
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• 1995

Bus, Which is together with subway the main part of public transportation modes in the city, is reviewed for the development of an optimal feeder-bus service area. Based on the IDRISI of GIS package, and taking into account of the convenience of downtown-oriented public transportation users at peak time, a model for the development of feeder-bus service area and a solution and introduced. Major result in this study is as follows: Development is given to a model that is designed to overcome the shortage of the existing models, which has limits in simulating the real situation; Variables were used in combination so that bus and subway route, station spacing, and operating frequency can be determined simultaneously, which enables to elucidate the mutual relationship and the structure in public transportation system. A model for feeder-bus area development is also given applied to determination and opening of subway and urban express bus route and new transportation systems. The model developed in this paper is useful in the case of extension and opening of subway and urban express bus route and new transportation Systems.

• Transactions of the Korean Society of Automotive Engineers
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• v.15 no.2
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• pp.58-64
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• 2007

As the concerns regarding global worming were increased, the pressure of greenhouse gas(GHG) emission reduction on mobile source was also increased. Carbon dioxides contribute over 90% of total GHG emission and the mobile source occupies about 20% of this $CO_2$ emission. Therefore automotive exhaust is suspected to be one of the major reasons of the rapid increase in greenhouse effect gases in ambient air. In this study, in order to investigate $CO_2$ emission characteristics from gasoline passenger cars(PC), which is the most dominant vehicle type in Korea, 106 vehicles were tested on the chassis dynamometer. $CO_2$ emissions and fuel efficiency were measured. The emission characteristics by displacement, gross vehicle weight, vehicle speed and CVS-75/vehicle speed mode were discussed. Test modes were vehicle speed modes and CVS-75 mode that have been used to develop emission factors and to regulate for light-duty vehicle in Korea. It was found that $CO_2$ emissions showed higher large displacement, heavy gross vehicle weight, low vehicle speed and CVS-75 mode than small displacement, light gross vehicle weight, high vehicle speed and vehicle speed mode, respectively. From these results, correlation between $CO_2$ emission and fuel efficiency was also determined. The results of this study will contribute to domestic greenhouse gas emissions calculation and making the national policy for climate change.

• Journal of Korean Society for Atmospheric Environment
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• v.24 no.3
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• pp.275-283
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• 2008

Since mobile source is a major source of VOCs, quantifying emissions from motor vehicles is an important factor to control VOCs in atmosphere. In this study, in order to evaluate tailpipe VOCs emissions from motor vehicles, mass emissions of non-methane volatile organic compounds from 45 vehicles were determined. Measurements were made on a chassis dynamometer using CVS-75 mode and speed specific drive modes. Target VOCs are 53 compounds determined as the volatile ozone precursors. The individual VOCs composition of vehicle emission and emission rates were also determined. In case of gasoline vehicles, VOCs emission from over 80,000 km vehicles were about 46% larger than less 80,000 km vehicles. The difference in benzene and toluene according to driving mileage was 44% and 26% respectively. The composition of VOCs were different by fuel type. The order of VOCs composition was paraffins>aromatics>olefins in gasoline vehicle emissions, paraffins>olefins>aromatics in light duty diesel vehicle emissions. The VOCs emissions were decreased as vehicle speed increasing. These results will be used to calculate total VOCs emissions from automobiles in the future.

• Journal of Korean Society of Transportation
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• v.24 no.2 s.88
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• pp.53-63
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• 2006

The objective of this study is to estimate Korean transportation service index (KTSI), and to explore possible uses of the KTSI. The KTSI was monthly index to represent the level of passenger and freight services by road, railroad, air and maritime modes, which was developed from eight series. Four of these series measure the level of passenger services (passenger-kilometers) by road, railroad. air and maritime modes : monthly data from January 1995 to December 2004. Similarly. the remaining four series measure the level or freight activity (tonnage) by four modes during the same period. Given the weights of modal revenues, component series were aggregated into two indexes (passenger index and freight index) and a composite index using Chained Fisher Ideal index. which was a geometric mean of the Laspeyres index and the Passche index. The Fisher Ideal index is one of the 'superlative' indexes, which diminish 'substitution bias' as current-weighted indexes. As a result, the freight index and the composite index explain economic conditions better than the passenger index. Based on the composite index. the newly estimated KTSI shows an average lag time of one and a half years at peaks and three months at troughs in comparison with domestic business cycles. Nonetheless. the following efforts are needed for more credible and useful estimates; establishment of data collection scheme in time. credibility uplift of used data, development of various indexation methods.

• Journal of the Korean Society for Railway
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• v.16 no.5
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• pp.418-429
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• 2013

This study assesses the appropriate amounts and applicable ranges of travel time values for freight transport modes in Korea. The findings suggest that it is possible to determine appropriate sizes and applicable ranges of travel time values of goods set for road transport mode (i.e. truck), whereas those for railway, inland waterway, marine, and air transport modes are not as easily estimated. The adequate travel time value for trucks is 20,000won/vehicle hour, and the application range of travel time value of trucks is 17,000~23,000won/vehicle hour considering other variables. The most adequate estimation method of determining the travel time value for road transport is the wage rate method, whereas the marginal rate of substitution method is more rational for railway, inland waterway, marine, and air transport modes considering the application purpose and characteristics of the goods transported.

• Journal of Korea Port Economic Association
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• v.31 no.3
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• pp.121-140
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• 2015

The present study examines how to construct a transport system for tourism in the marine city area of Yeosu. An effective tourism transport system is needed in Yeosu to promote ocean tourism in Korea's southern coastal region. The problems in Yeosu's transport system for ocean tourism were identified by comparing it with the Bay Area in the United States; future improvement methods were deduced accordingly. The transport support system for ocean tourism in Yeosu area was insufficient in many aspects compared with the Bay Area, such as intercity transportation, urban transport systems, and transport information systems. Thus, this study suggests various approaches to building a new ocean tourism transport support system in Yeosu. Connecting transport modes and ocean tourism resources, such as linking intercity and urban transport modes with ocean tourism transport modes, is suggested. It is also recommended that a cooperative transport support system be established for ocean tourism in the neighboring regions of Yeosu. Furthermore, an integrated transport information system for ocean tourism needs to be provided to connect the system efficiently with ocean tourists. This integrated transport support system could lead to a decrease in the cost and time needed for travel.