• Journal of Korean Port Research
• /
• v.7 no.1
• /
• pp.43-58
• /
• 1993

There has been fast progress in economy in Korea derived by a consecutive five-year plan program for economic development started in the early 1960's. In the field of transportation, rapid changes in the technological environment of transportation and communication have brought a revolution of the transport system, of which inter-modal transportation through containerisation is typical. Because of the rapidly growing traffic volumes of cargo, especially container traffic, and lack of investment into transport infrastructure in the past, both road and railway are beyond their capacity. As a result, the public-road network has suffered a serious congestion problem. For instance, in relation to the corridor between Seoul and Pusan, today, it takes about 14 hours for the journey of container trailer through Kyongbu Expressway, for which it used to take only 7 hours in 1986. For the railway, though the congestion problem is not very serious compared with the road sector, a shortage of capacity on certain main lines has emerged as a problem as railway traffic has increased. Furthermore, the further expansion of the system in near future is difficult due to burden of higher construction the cost. Unlike these two modes, coastal shipping, which has been paid relatively less attention for commodity transport in Korea, shows no constraint in this respect. In addition, it is the most cost efficient mode of transport. This work therefore aims to make a proposal for the alternative inland transportation mode, which is to promote the coastal transport of container. Three obstructing factors for the promotion of the coastal transport are investigated and some solutions for those are suggested as follows : First, it appears to be essential to provide exclusive ports for the coastal shipping, that comply with simplification, specialization and rationalization. The optimum size of berths on the exclusive ports in Pusan port is estimated as 16-20. We found that it needs periodical study and publicity on the advantages from the adoption of the coastal mode. Inducing competition in the coastal shipping market is also necessary. For the supply of the fleet in the coastal shipping, chartering of the surplus ships in the oversea shipping is found to be more desirable than new shipbuilding. Second, to solve the fragmentation of the companies which wish to participate in the coastal transport, government has to implement the subsidy policy. The encouragement of participation of the shipping lines engaging in Korea-Japan run and Korea-East South Asia run, into coastal shipping also needs to be considered cautiously. Third, simplification of the document for entry in ports is needed for rational coastal shipping management. We can use B/L (Bill of Lading) for coastal shipping as a prerequisite to get the indemnity by P & I Club. The reduction of the government controls on entering and leaving the ports also needs.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.17 no.2
• /
• pp.1-7
• /
• 2016

Although the second driving device of KTX, which consists of the wheel and the axle reduction gears unit, is a mechanically integrated structure, its preventive maintenance (PM) requires two separate intervals due to the different technical requirements. In particular, these subsystems perform attaching and detaching work simultaneously according to the maintenance directive. Therefore, to reduce the unnecessary amount of PM and high logistic availability of the train, it is important to optimize PM with regard to reliability-centered maintenance toward a cost-effective solution. In this study, fault tree analysis and reliability of the subsystems, considering the criticality of the components, were performed using the data derived from field data in maintenance. The cost optimization of the PM was derived from a genetic algorithm considering the target reliability and improvement factor. The cost optimization was derived from a maximum of the fitness function of the individual in generation. The optimal TBO of them using the genetic algorithm was 2.85x106 km, which is reduced to approximately 21% compared to the conventional method.

• Journal of Korean Society of Transportation
• /
• v.28 no.2
• /
• pp.171-181
• /
• 2010

The integrated transit fare system of Seoul metropolitan area has given positively evaluated with reduction of user cost and activating the transfer behavior from its opening year, July 2007. However, there were only few research about railway demand forecasting methodology, especially mode share, has conducted under the integrated fare system. This study focuses on the utility estimation by each mode under the integrated fare system, and on the coefficient actualization relates on travel time and travel cost estimation with Household Travel Survey Data 2006. Also the railway demand analysis methodology under various fare systems is presented. The methodology from this study is expected to improve accuracy and usefulness in railway demand analysis.

• Proceedings of the KSR Conference
• /
• 2011.05a
• /
• pp.745-752
• /
• 2011

Light Rail Vehicle(LRT) is "New Transit System" that has transportation capacity as well as physical size of vehicle is in-between bus and subway. The demand of LRT system is increasing rapidly; both domestically and internationally. Reason being is that it is more economical and eco-friendly compare to existing heavy rail vehicle. Especially, Busan Subway Line 4 K-AGT (Rubber-tired LRT) being the first of its kind to start revenue service in Korea, it is very much likely that application of its demand will continue to increase. Considering its trend, study to reduce implementation cost of LRT is being pursued in many different aspects; reducing construction cost is one that aspect. In this study, on-site application of 'Up-Down Turnout System' implementation research has been carried out which can replace existing 'Left-Right Turnout System'. When safety of its type gets verified, application of this system to line which intends to use K-AGT, Shin-Lim Line and Dong-Book Line, expects to save its construction cost. This thesis paper reports ongoing research of AGT 'Up-Down Turnout System' development and main component design factors, fundamental principle, performance test result.

• Proceedings of the KSR Conference
• /
• 2007.11a
• /
• pp.792-800
• /
• 2007

The annual power cost for Seoul metro operations is about 65.5 billion won, of which rail motors account for 60% among total power consumptions. It is expected that the power consumption would increase because of global warming, future high electric equipments demands, etc. To reduce these consumptions, it is necessary to analyze the transportation demands of passengers, arrange the power-saving driving environments, respond flexible vehicles service, and improve how to drive vehicles. These method to reduce power consumption for rail motors can lead to improve the Seoul metro management. In this research, the improvement plan is derived by collecting and analyzing the data for total 33 power consumptions factors, screening top 10 factors by priority and impact, establishing each hypothesis to execute correlation and recursion analyses. As a result of 4 items research among top 10 affected factors, the power consumption for rail motors in 2006 is effectively reduced; the power usage is down with 13,870 kwh, from 531,539 kwh to 517,669 kwh, and the cost is down with 1,026 million won, from 39, 334 million won to 38,308 million won.

• International Journal of Highway Engineering
• /
• v.15 no.2
• /
• pp.169-181
• /
• 2013

PURPOSES : This study is to suggest the Influence of road capital to industry and productivity growth in South Korea. METHODS : Based on the literature review, The relevant policy questions addressed in this report are : cost reduction and Scale elasticities of road, effect of road capital stock on demand for labor, capital and materials, marginal effect of road, industry TFP growth decomposition. RESULTS : The marginal benefits of the road capital at the industry level were calculated using the estimated cost elasticities. Demand for the road capital services varies across industries as do the marginal effects. The marginal benefits are positive for the principal industries. This suggests that for these industries the existing stock of road capital may be under supplied. The contribution of road capital to TFP growth is positive in principal industries. The main contribution of road capital is in the manufacturing industries ; the magnitudes of contribution varies among industries. These results indicate that growth in exogenous demand is most important contributor to TFP growth. CONCLUSIONS : The road capital have a significant effect on employment, private capital and demand for materials inputs in all industries. At a given level of output, an increase in road capital lead to variety to demand for all inputs in all industries.

• Perspectives in Nursing Science
• /
• v.6 no.1
• /
• pp.55-65
• /
• 2009

The Korean government introduced Home Care Services System to cut medical cost and make efficient use of limited medical resources because of increasing chronic diseases and the growing population of the elderly. The Korean government established measures to control the use of insurance services by restricting the number of nurse's visits to patient's home and by asking the patients to shoulder the transportation fee of nurses during the visit. Factors such as oversupply of hospital facilities, low price of home care services, high insurance coverage for hospital services and increased nuclear family set up resulted in the limited use of home care nursing services. The introduction of long-term care insurance in 2007 brought the decrease in the number of home care agencies and these agencies are facing a crisis today. The increase in chronic diseases and growing population of the elderly recently resulted in the need to control the high medical cost. Home care services for early discharge patients and chronic-severe disease patients will contribute in the reduction of medical cost at the same time improves the quality of patient's life. To catch up with the demands of the nation, accessibility to home care services should be improved and policies such as the expansion of home care services insurance coverage and promotion of establishing home care agencies should be considered.

• Journal of Korean Society for Quality Management
• /
• v.46 no.4
• /
• pp.899-910
• /
• 2018

Purpose: Generally, since the population density is lower in suburban areas, the distance to school is inevitably long. Therefore, schools in suburban areas often operate school buses to improve student welfare. However, since school buses are usually used only during going to and from school, the utilization rates are relatively low. Therefore, this study aims to establish integrated operation plan of public school bus covering all schools. Methods: It is necessary to decide which school buses will serve the specific demand node which want to go to certain school in order to design an integrated operation plan for school buses. Therefore, a mathematical model is developed for minimizing the total number of vehicles and the distance of transportation by reflecting the characteristics of school buses and students as constraints. To solve the proposed mathematical model, CPLEX, a commercial solver, is applied. Results: To validate and to confirm the proposed process, numerical example is designed with the comparison between before and after integrated operations of school buses in terms of total operation cost. The result shows that the integrated operation can lead the reduction of the number of school buses as well as the decreasing of the fuel cost. Conclusion: This study provides the quantitative method to perform the integrated operation of school buses in suburban areas. The optimal operation strategy is required because there are more complex decision-making elements considering the integrated operation. It is expected to apply this research result at real situation to expand this services based on an optimal operation.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.8 no.11
• /
• pp.1675-1680
• /
• 2013

Recently, the permanent magnet linear synchronous motor as low noise, high speed and high thrust force transportation system has been proposed but this motor causes an increase of material cost because of its characteristic arranging the armature on the full length of transportation lines when this system is applied to the long distance transportation system. Therefore, we suggested discontinuous arrangement method of the armature to solve this problem. However, Detent force which causes thrust force ripple generating noise, vibration and decline of performance is generated when a mover pass between the armatures. Thus, in this paper, we examined characteristic of detent force to reduce the end edge effect according to the end edge teeth's height and auxiliary teeth and suggested the shape that can the most reduce the detent force.

• Journal of Welding and Joining
• /
• v.34 no.5
• /
• pp.19-25
• /
• 2016

Global warming is hot issue to keep the earth everlastingly. Despite the increase of the world population and the energy demand, the world oil supply and the oil price are hold the steady state. If we are not decrease the world population and the energy consumption, unforeseeable energy crisis will come in the immediate future. AMT acronym of Advanced Materials for Transportation is a non-profitable IEA-affiliated organization to mitigate the oil consumption and the environment contamination for the transportation. In recent, Annex X Multi-materials Joining was added to enhance the car body weight reduction cause the high fuel efficiency and the low emission of exhaust gas. Multi-materials are the advanced materials application technology to optimize the weight, the performance and the cost with the combination of different materials such as Al-alloy, Mg- alloy, AHSS and CFRP. In this study, the trends of AMT strategy and Al-alloy based multi-materials joining technology were review. Also several technologies for Al-alloy dissimilar joining were investigated.