• Journal of the Korea Safety Management & Science
• /
• v.2 no.3
• /
• pp.61-79
• /
• 2000

It is very important to delivery timely and safely items in logistics. So, the home delivery service system is introduced by many enterprises. Also, the beginning in 1990's, the rapid increase of automobile increased logistics cost and led to road stagnation. So, the railway transportation use in logistics can be considered. The railway transportation in home delivery service system can overcome the limit of transportation by land. This study evaluate railway transportation in home delivery service system by economical efficiency and timeliness.

• Journal of the Korean association of regional geographers
• /
• v.2 no.2
• /
• pp.37-47
• /
• 1996

It is well agreed that transportation is not the end by itself, rather it is a means to achieve other goals to enhance the quality of life. Accordingly, various social impacts of transportation systems, such as destruction of community social life of urban residents, separation of community area, and accessibility restriction on the transportation handicapped, which can deteriorate the quality of life of the residents should be considered seriously in the process of urban transportation planning. The urban transportation planning process of Korea which emphasizes too much on the of efficiency objectives of transportation, however, have neglected greatly the social sides of urban transportation systems. This paper discusses major social impacts of urban transportation systems in Korea and proposes several research fields related to the social impacts of urban transportation.

• Journal of Korean Society of Transportation
• /
• v.25 no.3
• /
• pp.55-63
• /
• 2007

This paper analyzes the relative efficiency of Korea's logistics industry with the DEA-ANP model from 2003 to 2005. To measure the efficiency, this paper used the numbers of employees, fixed assets. total capital. and operating costs as input factors and sales amounts and net incomes as output factors. The average efficiency score of the entire logistics industry is 0.175, so most logistics companies in Korea should improve their current inefficiencies. The industry with the highest efficiency score is marine transportation. with an average three-year efficiency score of 0.3692. In terms of sales and high efficiency. most of the highest-ranked companies belong to the marine transportation industry, so marine transportation has the most influence on raising the efficiency score of Korea's logistics industry. To improve the inefficiency of inputs that exists overall in the logistics industry it is necessary to control excessive numbers of employees. To improve the amount of sales, it is necessary to make a policy of satisfying various logistics demands, continuous investments, and attracting foreign logistics demand: such things will help strengthen the international competitiveness of Korea's logistics industry.

• Proceedings of the KSR Conference
• /
• 2010.06a
• /
• pp.2297-2302
• /
• 2010

The status and effectiveness of Bi-modal Tram is analyzed through the comparison of the transport effectiveness and operation cost between the public transportation systems (bus, light rail transit) considering the vehicle and operation characteristic of new transit system Bi-modal Tram. The standard operation schedule is established in consideration of the vehicle specification and operation characteristic of main public transportation modes, and then the annual average operation cost is estimated depending on the volume, speed, analysis length for respective public transportation mode. Through analyzing the operation cost and distribution characteristic of public transportation modes depending on the transport volume and travel speed, the operational efficiency suitable for the city is derived. It is concluded that the operational efficiency of Bi-modal Tram is superior to that of the bus and light rail transit on the aspect of travel volume and operation speed.

• Journal of the Korean Society of Safety
• /
• v.24 no.6
• /
• pp.79-85
• /
• 2009

This study presents an algorithm to select the best alternative plane among various bridge superstructure types(Steel box girder, Rational girder, PSC-I girder) using Value Engineering(VE). Economical efficiency, landscape, constructability, maintenance, stability, function of bridge superstructure were taken into consideration in the designing of bridge. Economical efficiency was evaluated for each alternative plan with optimal design considering Life Cycle Cost(LCC). Repair and rehabilitation histories and some factors were set to get reasonable results. In the application of Analytic Hierarchy Process(AHP), consistency of Pairwise Comparisons Matrix was evaluated and the best plan was determined.

• Proceedings of the KSR Conference
• /
• 2008.11b
• /
• pp.112-116
• /
• 2008

Determining the investment priority of the railway project is essential to keep its object of railway investment. [National railway construction plan] provide 4 major evaluation indicators and their weighting range in determining the investment priority of railway construction. Which are investment efficiency, inter-regional balance of development, network effects, government supporting policy. However this present criteria has inconsistency in determining economical feasibility of the railway transportation when applying the same evaluation indicator, investment efficiency, with the road transportation. The railway transportation is superior to road transportation in terms of transportation capacity and distance, while offering less carbon emissions. In spite of the prominent position of the railway transportation, it can be failed to obtain its proper investment priority when being determined under economical feasibility based. Therefore, this study analyzed the inconsistency under present evaluation criteria and proposed new evaluation method for the investment priority of the railway construction using AHP(analytic hierarchy process), while differentiate from the road construction. This method is optimized for only determining the priority of the railway construction itself under object of railway investment respectively.

• Structural Monitoring and Maintenance
• /
• v.5 no.4
• /
• pp.489-506
• /
• 2018

This paper reported test of full-scale cables attached with four types of dampers: viscous damper, passive Magneto-Rheological (MR) damper, friction damper and High Damping Rubber (HDR) damper. The logarithmic decrements of the cable with attached dampers were calculated from free vibration time history. The efficiency ratios of the mean damping ratios of the tested four dampers to theoretical maximum damping ratio were derived, which was very important for practical damper design and parameter optimization. Non-ideal factors affecting damper performance were discussed based on the test results. The effects of concentrated mass and negative stiffness were discussed in detail and compared theoretically. Approximate formulations were derived and verified using numerical solutions. The critical values for non-dimensional concentrated mass coefficient and negative stiffness were identified. Efficiency ratios were approximately 0.6, 0.6, and 0.3 for the viscous damper, passive MR damper and HDR damper, respectively. The efficiency ratio for the friction damper was between 0-1.0. The effects of concentrated mass and negative stiffness on cable damping were positive as both could increase damping ratio; the concentrated mass was more effective than negative stiffness for higher vibration modes.

• Journal of Korean Society of Transportation
• /
• v.28 no.4
• /
• pp.157-166
• /
• 2010

The aim of this paper was to estimate efficiency using a directional distance function to compare performances of bus agencies to determine if they have made efforts to operate efficiently and reduce emissions and accidents since public transportation reforms 2004. Drivers, mechanics, staff, buses, and fuel were used as input data and vehicle-kilometers (a desirable output), accident costs, and emission costs (undesirable outputs) as output data during June 2005. As a result, the efficiency with undesirable outputs was lower than the efficiency without undesirable outputs. However, the number of efficient agencies was more in case of the consideration of undesirable outputs. The reason is that the number of agencies whose possibility to reduce undesirable outputs are less than the possibility to reduce inputs was increasing, while the efficiency deviation among agencies was larger in case of the consideration of undesirable outputs. Meanwhile, the increase of CNG buses and operating speed and the improvement of mechanical efficiency had positive influence on the efficiency.

• Proceedings of the KSR Conference
• /
• 2011.05a
• /
• pp.521-527
• /
• 2011

Korea announced GHG reduction goal, 30% reduction compare with 2020 BAU and reduction target for each industry sector is planning. Transportation sector also trying to make effective technical and political counterplan of allocated GHG reduction target such as material lightening, energy efficiency improvement and Modal shift technology and so on. Modal Shift is shifting low energy efficiency vehicle to high energy efficiency vehicle which is economically meaningful under current market conditions. We can get not only energy efficiency improvement but also GHG reduction effect through modal shift. Modal Shift is effectively applying and studied in logistics field in Europe and Japan and one of the Indian companies has been registered CDM project activity involving modal shift from roadways to railways for finished goods. In this study, the scenarios are developed with detail modal shift ratio and fuel type base on state of road and rail use and GHG emission factor for each fuel type from MLTM. This result can be used as basic information to improve policies and promote increasing use of train which is more environment friendly transportation vehicle.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.32 no.1
• /
• pp.44-51
• /
• 2009

A bonded warehouse is the warehouse located in bonded area. It functions not only as a general warehouse but also as a place for managing the work related to import and export bonded goods. As a general warehouse, it uses the rack system to store the goods and the folk lift truck to move the unitized goods. The operation of the storing system closely related to the efficiency of space uses in a warehouse and vehicle working. Thus, vehicle performance measured in distance units in the ware-house could be used as one of the key performance measure in warehouse system. This paper focuses on the operation efficiency of the bonded warehouse which uses rack system for the storing and the folk lift truck for moving goods. The method of load allocation for balancing the rack uses and vehicle operation for maximizing efficiency are the specific concerns in this paper. The simulation study is conducted to find a policy for efficient vehicle operation based on balanced rack utilization, and the favorable result for the system operation would lead the usable proposal in vehicle operation.