• Journal of Korean Society of Transportation
• /
• v.9 no.1
• /
• pp.5-18
• /
• 1991

Two-Lane, two-way roads account for approximately 92% of total road length in Korea and accomplish the majority of regional transport activities. Nevertheless not too many research have been made on two-lane roads particularly efficiency related topics such as capacity and travel time studies. In this study a full scale data collection was conducted using video equippments on rural two-lane roads to determine capacity Passenger Car Equivalents(PCE) and Level of Service criterion. Various PC programs were utilized to reduce traffic data and Walker ME? and Headway Method were employed to determine PCE's for heavy vehicles. The reseach has shown that capacity and PCE's for two-land two-way roads in Korea are 3200 pcph and 1.1∼1.9 resectively. In addition percent time delay was used as the basis of developing Level of service criterion on two-lane roads in Korea.

• Journal of Korean Institute of Industrial Engineers
• /
• v.34 no.3
• /
• pp.296-307
• /
• 2008

A semiconductor production system has sophisticated manufacturing operations and needs high capital investment for its expensive equipment, which warrants efficient real-time flow control for wafers. In the bay, we consider material handling equipment that can handle multiple carriers of wafers. The dispatching logic first determines the transportation time of each carrier to its destination by each unit of transportation equipment and uses this information to determine the destination machine and target carrier. When there is no available buffer space at the machine tool, the logic allows carriers to stay at the buffer of a machine tool and determine the delay time, which is used to determine the destination of carriers in URL. A simulation study shows this dispatching logic performs better than the procedure currently in use to reduce the mean flow time and average WIP of wafers and increase efficiency of material handling equipment.

• Transportation Technology and Policy
• /
• v.6 no.1
• /
• pp.155-170
• /
• 2009

In an effort to increase the operational efficiency of highways, South Korea has been increasing its design speed recently. However, the use of higher design speed will also increase construction costs. Moreover, increasing the design speed is expected to have an impact on safety. Hence, there is a strong need to demonstrate that the benefits outweigh the cost of having a higher design speed. This study surveyed a sample of design engineers to determine their awareness of the consequences of increasing design speed and their assessment of the right design speed for an actual rural arterial. In addition to the survey, a case study of three recently upgraded highways was conducted to determine the changes in traffic volumes, speeds, travel times, and safety.

• The Transactions of the Korean Institute of Electrical Engineers P
• /
• v.55 no.4
• /
• pp.176-182
• /
• 2006

In this paper, we explore a novel transportation container in the marine terminals. The container includes Smart Tag embedded with radio frequency(RF) chips, which is used to access information about productions and possibly incorporated with GPS systems for integrated managements of them. The proposed mechanism is valuable for decreasing cost, increasing satisfaction of customers, and preventing economic loss due to production missing, thus increase of economic efficiency is highly anticipated. Consequently, accurate and proficient management is considerably accomplished in overall procedures of inventory and currency by means of the proposed systems.

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.20 no.4
• /
• pp.373-380
• /
• 2010

An interest is increased of environment and energy so, importance on railroad high energy efficiency is magnified. And after Gyeong-bu High speed rail is completed, share rate freight transportation of railroad is expected to be gradually increased due to expand investment for railroad and operate mainly freight transportation on convention line. Therefore a research on DMT freight cars is necessary under like this situation. In paper, we developed analysis model for DMT freight car and DMT freight was analyzed numerically using VI-Rail in each condition of railway having different curve and carried out vibration analysis on curving using developed analysis model. And we carried out test on driving stability follow changing curve radius then measure against UIC code 518.

• Proceedings of the KSR Conference
• /
• 2008.06a
• /
• pp.2195-2199
• /
• 2008

The concern on sustainable development is increased to solve the global warming which is environmental issue over nations. Sustainable development is the concept of minimizing the consumption of resource and environment burden. In transportation, there are some trials of shifting to green transportation mode through low energy consumption and high efficiency. Korea Tilting Train eXpress (TTX) can run higher speed than existing train and save energy through light weight. In this study, Tilting bogie, the core equipment of tilting train, was compared with that of existing train.

• Proceedings of the KSR Conference
• /
• 2009.05a
• /
• pp.966-971
• /
• 2009

The recent environmental protection trend requires more strict energy saving, therefore every transportation system should reduce energy consumption to the minimum value. High-efficiency operation system, energy saving and CO2 emissions shall be addressed as important issue in railway system. These issues are the most essential factors of railway, compared to major public transportation system. Recently, saving energy in the electric railway system has been studied. For such new energy saving, the Energy storage system is considered for saving energy. Energy saving is possible by efficient use of regenerated energy. Regenerated energy is recycled amongst vehicles by mean of charge and discharge corresponding to powering and braking of electric vehicle operations. This energy saving contributes to cut CO2 to reduce greenhouse gas emissions. Recycling regenerated energy demonstrate significant effect on peak cut of consumption energy in railway substation. Absorption of excess energy avoids regeneration failure due to high traction voltage. This paper presents effects by applying the energy storage system to SeoulMetro Line 2.

• Proceedings of the KSR Conference
• /
• 2004.10a
• /
• pp.1701-1706
• /
• 2004

FRT design aims at high-tech vehicles of high efficiency and cleanness, it must materialize the meaning and role as new added value by applying car design aesthetics of a new future-oriented concept. In addition, different from ordinary vehicle design, FRT involves invisible factors such as pleasantness, safety, accessibility, controllability, movability, conveniency, culture, identity, brand image and fashionableness. Because FRT vehicles are transportation means used by various groups of people, they must be approached with the barrier-free design concept. Therefore, in order to enhance the potential of future transportation culture emphasizing creativity based on diversity, it is important to establish core design factors that create new added values and to apply new concepts to their roles.

• Journal of the Korea Safety Management & Science
• /
• v.12 no.3
• /
• pp.163-168
• /
• 2010

Recently, there are many problems of service qualities such as regular-rapid-safe -comfortable transport, that was traditionally advantages in urban railway transportations. These problems cause train delays that affects consecutive schedule, capacity, operation plans, and it is hard to prevent the propagation of delay and find the recovery solution. Because the urban transport demands is continuously increased and the railway service is also expanded, the railway operation company makes efforts to improve operation performance and efficiency for passengers. In this paper, we analyse the issues and problems existing in the major operation line of high-density urban railways, and suggest the development direction of intelligent operation technology to improve the urban railway service by minimizing the occurrence and propagation of delay. And the result of numerical case study is also presented.

• Journal of the Semiconductor & Display Technology
• /
• v.15 no.3
• /
• pp.6-11
• /
• 2016

Silicon wafer is one of main materials in solar cell. Micro-cracks in silicon wafer are one of reasons to decrease efficiency of energy transformation. They couldn't be observed by human eye. Also, their shape is not only various but also complicated. Accordingly, their shape classification is absolutely needed for manufacturing process quality and its feedback. The performance of typical classification techniques which is principal component analysis(PCA), neural network, fusion model to integrate PCA with neural network, and support vector machine(SVM), are evaluated using pattern features of micro-cracks. As a result, it has been confirmed that the SVM gives good results in micro-crack classification.