• The KIPS Transactions:PartD
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• v.18D no.5
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• pp.371-384
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• 2011

This paper considers logistics decision support system which deals with transportation mode selection considering transportation and carbon emission cost. Transportation and carbon emission costs vary with the choice of transportation modes and to become competitive companies need to find proper transportation modes for their logistics services. However, due to the restricted capacity of transportation modes, it is difficult to balance transportation and carbon emission costs when designing logistics network including transportation mode choice for each service. Therefore this paper aims to analyze the trade-off relationship between transportation and carbon emission cost in mode selection of intermodal transportation and to provide optimal green logistics strategy. In this paper, the logistics decision support system is designed based on mixed integer programming model. To understand the trade-off relationship of transportation and carbon emission cost, the system is tested with various scenarios including transportation of containers between Seoul and Busan. The analysis results show that, even though sea transportation combined with trucking is competitive in carbon emission per unit distance travelled, the total cost of carbon emission and transportation for the sea transportation may not have competitive advantage over other transportation modes including rail and truck transportation modes. The sea-based intermodal logistics service may induce detours which have negative impacts on the overall carbon emission. The proposed logistics decision support system is expected to play key role in green logistics and supply chain management.

• Journal of Korean Institute of Industrial Engineers
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• v.32 no.3
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• pp.163-171
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• 2006

This paper considers a scheduling problem to minimize the sum of the associated scheduling (production/delivery times) cost and the delivery cost for an integrated system of a single production machine and various transportation vehicles with transportation mode selection allowed. Each transportation mode is provided with a fixed number of vehicles at the associated delivery time and cost. The proposed problem is characterized as being NP-hard. Some solution properties are also characterized. Therewith, three heuristic algorithms (called SPT-based, LWF-based and WSPT-based heuristic) and a branch-and-bound algorithm are derived. In order to evaluate the effectiveness and efficiency of the proposed algorithms, computational experiments are made with some numerical instances.

• Journal of Korea Port Economic Association
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• v.34 no.2
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• pp.83-96
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• 2018

The improvement in logistics competitiveness is the key element of corporate competitiveness in the era of severe competition among companies and high oil prices due to globalization. For this reason, this study analyzed the effect of transportation mode selection factors of Indonesian export companies on the logistic performance in accordance with the logistics environment. The results of the analysis show that only the cargo characteristics, which are the transportation mode selection factor of export companies, had a significant effect on logistics; the services, time, and expenses, on the other hand, had no effect on logistics performances. This result reflects the poor logistic infrastructure of Indonesia. While the export company considers service, time, and expenses when choosing transportation mode, it had no effect on logistic performances due to poor logistic infrastructure. The poor logistic infrastructure of Indonesia has caused a rise in the overall logistic expenses of companies due to excessive transportation time over the transportation distance, unavailability of on-time acceptance and delivery, and increase in the transportation expenses and subsidiary expenses. These are also the factors that decrease the competitiveness of export companies and affect the promotion of the manufacturing industry and foreign investment for the purpose of job creation and industrialization by the Indonesian government. Therefore, the logistics infrastructure must be improved initially. This study determines various points in terms of the logistics infrastructure environment of Indonesia, a developing country, using previous studies and provides their implications.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.12
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• pp.5347-5360
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• 2016

In decode and forward relay systems, choosing the duplex mode is an important factor to the performance. To satisfy the performance requirement, self-interference must be mitigated for the full-duplex relay (FDR), and the resource efficiency must be increased for the half-duplex ratio (HDR). Therefore, if a wise scheme to consider these two factors exists, decode and forward relay systems are used more effectively. This study proposes a new duplex selection scheme for decode and forward relay systems. The proposed duplex selection scheme chooses the better duplex mode according to the channel statistical conditions with optimal power allocation. The simulation results show that the proposed duplex scheme with optimal power allocation has lower outage probability than the FDR and the HDR.

• Korean Journal of Geomatics
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• v.3 no.2
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• pp.123-128
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• 2004

As the applied fields of GIS are expanded to the transportation, developing internet-based applications for transportation information is getting attention increasingly. Most applications developed so far are primarily focused on guidance systems for owner-driven cars. Although some recent ones are devoted to public transportation systems, they show limitations in dealing with the following aspects: (i) people may change transportation means not only within the same type but also among different modes such as between buses and subways, and (ii) the system should take into account the time taken in transfer from one mode to the other. This study suggest the framework for developing a public transportation guidance system that generates optimized paths in the transportation network of mixed means including buses, subways and other modes. For this study, the Genetic Algorithms are used to find the best routes that take into account transfer time and other service-time constraints.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2004.02a
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• pp.59-63
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• 2004

As the applied fields of GIS are expanded to the transportation, developing internet-based applications for transportation information is getting attention increasingly. Most applications developed so far are primarily focused on guidance systems for owner-driven cars. Although some recent ones are devoted to public transportation systems, they show limitations in dealing with the following aspects: (i) people may change transportation means not only within the same type but also among different modes such as between buses and subways, and (ii) the system should take into account the time taken in transfer from one mode to the other. This study suggest the framework for developing a public transportation guidance system that generates optimized paths in the transportation network of mixed means including buses, subways and other modes. For this study, the Genetic Algorithms are used to find the best routes that take into account transfer time and other service-time constraints.

• Proceedings of the Korea Society for Simulation Conference
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• 1998.10a
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• pp.46-50
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• 1998

본 연구는 최근에 국내기업의 물류비용절감을 위한 노력의 일환으로 추진되고 있는 적정 물류장비의 선정을 위한 시뮬레이션 모델의 개발이다. 본 연구에서는 제조공장에서 소비자들에게 공급되는 2단계 물류시스템에서 물류재고와 운송수단을 고려하여 최소 물류비용의 운송대안선정을 위한 의사결정을 할 수 있도록 개발하였다. 이를 위하여 2가지의 시뮬레이션모델의 전산프로그램을 개발하고 응용사례를 통하여 출력을 예시하였다.

• Journal of Korea Port Economic Association
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• v.29 no.3
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• pp.113-133
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• 2013

Since 1995, Korean enterprises have been rapidly expanding their business, especially to Eastern European countries such as Poland, Slovakia, Czech Republic, Hungary and so on. After the establishment of Korea-EU FTA in 2011, close relationship between the two through economic cooperation has been maintained. To efficiently connect the seaport regions to inland factories located in Eastern European countries, researches on mode choice in the intermodal sector are needed to perform. However, there is a scant of research for mode choice factors on intermodal transportation service in Europe. Therefore, the aim of this research is to understand the current situation of intermodal transportation sector in Europe, identify key factors of mode choice, and weigh the importance among factors influencing intermodal selection in the perspective of Korean exporters or forwarders with overseas cargo to Europe. A survey and in-depth interviews to CEOs and executives who have more than 20 to 30 years of career in logistics sector were carried out from April 01 to May 01, 2013. Using the fuzzy theory as the methodology, 'Reliability of arrival time', 'Transit time', and 'Freight Rate' are equally ranked as the most important factor in the selection of intermodal transportation.

• Journal of Korean Society of Transportation
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• v.19 no.4
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• pp.97-108
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• 2001

A dynamic transportation management should be applied specially in AM peak because AM peak is more critical than PM peak in traffic volume and demand. AM peak trip can be characterized by commuting and schooling. which have the high level of usage on public transportation, and constraint on arrival time. So transportation management applied in AM peak could deal with a mode choice and an arrival time constrain. Researchers were involved in the dynamic transportation assignment models for management of congested traffic network. But, there were no models which considered a mode choice and an arrival time constrain should be included in management of AM peak. So there are limits to use exist models to control and analyze AM peak traffic. In this study, it is proposed the combined dynamic transportation model, considering a mode choice and the start time selection with arrival time constrains, based on Ran and Boyce's model. The proposed model is verified the compatibility by applying to the newly designed time space expanded network. The result shows that proposed model consistent with dynamic user optimal travel pattern. From this we certificate the applicability of the proposed model to control and analyze AM peak traffic.

• 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.