• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.6
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• pp.1108-1114
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• 2016

The cause of failure in the AT feeding system is divided into grounding, short-circuit of feeding circuit and internal faults of the railway substation. Since the fault current is very high, real-time current is detected and the failure must be immediately removed. In this paper, a new DC offset elimination filter that can remove component to decrease in the form of exponential function using low-pass filter was proposed in order to extract the fundamental wave from distorted fault current. In order to confirm the performance of the proposed filter method, AT feeder system was modelled by simulation tool and simulations were performed under various conditions such as fault location, fault resistance and fault voltage phase angle in case of trolley-rail short-circuit fault. When applying the proposed DC-offset removal method, it can be seen that the phase delay and gain error did not appear.

• Journal of the Society of Naval Architects of Korea
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• v.50 no.5
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• pp.298-306
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• 2013

Nowadays, a transporter manager plans the schedule of the block transportation by considering the experience of the manager, the production process of the blocks and the priority of the block transportation in shipyard. The schedule planning of the block transportation should be rearranged for the reflection of the path blocking cases occurred by unexpected obstacles or delays in transportation. In this paper, the optimal block transportation path planning system is developed for rearranging the schedule of the block transportation by considering the damaged path. $A^*$ algorithm is applied to calculate the new shortest path between the departure and arrival of the blocks transported through the damaged path. In this algorithm, the first node of the damaged path is considered as the starting position of the new shortest path, and then the shortest path calculation is completed if the new shortest path is connected to the one of nodes in the original path. In addition, the data structure for the algorithm is designed. This optimal block transportation path planning system is applied to the Philippine Subic shipyard and the ability of the rapid path modification is verified.

• Journal of Power System Engineering
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• v.12 no.6
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• pp.56-63
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• 2008

Many advanced nations have been developing the next generation logistic systems to effectively deal with gradually increased logistic flows over the world. Particularly, dual mode trailer(DMT) systems are significantly focused as a new alternative transportation which basically provides integrating of the land and railroad services. This paper presents new driving mechanism for DMT systems using the hydraulic pressure cylinder systems. Such is mechanically composed of supporting and rotating parts independently, which are mostly important for whole system performance. We analyze feasible operational problem occurred in driving mechanism from the conventional DMT systems and compare our proposed deign specification with the Modalohr DMT system to demonstrate its reliability and practicability.

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

• 한국신재생에너지학회:학술대회논문집
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• 2011.11a
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• pp.152.1-152.1
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• 2011

This study analyzes transitions to a green path in transportation system in South Korea. We develop transportation system model with four new technology options, green cars; Hybrid electric vehicle, plug-in hybrid vehicle, electric vehicle and fuel cell vehicle. Among those technologies fuel cell vehicle is the best option assuming no GHG emissions when driving. We use MESSAGE model to get an optimal solution of pathway for high deployment of fuel cell vehicles under the Korea BAU transportation model. Among hydrogen production sources, off gas hydrogen is most economic since it is hardly used to other chemical sources or emits in South Korea. According to off gas hydrogen projection it can run 1.8 million fuel cell vehicles in 2040 which corresponds to 10% of all passenger cars expected in Korea in 2040. However, there are concerns associated with technology maturity, cost uncertainty which has contradictions. But clean pathway with off gas and renewable sources may provide a strong driving force for energy transition in transportation in South Korea.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2010.05b
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• pp.17-20
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• 2010

Recent Construction and Transportation R&D projects are larger in size, investment scale has been increasing rapidly. However, the results of Construction and Transportation in R & D are papers, patents and other results. So, the application record of R&D in the construction field is very lacking. In particular, Construction New Technology's ratio in the midst of R&D's results are about 2.29%. Therefore, this study suggested program that R&D's results has been connected Construction New Technology. The introduction of the new system has greatly increased Construction New Technology and the results of excellent &D will be applied in construction field. So, Cost-reduction and technology's improvement are expected.

• Journal of the Korea Safety Management & Science
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• v.9 no.6
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• pp.137-146
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• 2007

The objective of this paper is to study the establishing system of truck collaboration and to reduce traffic cost for participating transportation enterprises. The system of truck collaboration can enhance the transport efficiency and to reduce traffic cost without new investment for trucks and equipments. The type of truck collaboration should be enumerated (1) the system of head and branch base (2) the system of central terminal (3) the system of separating collection and delivery for cargo (4) the system of cooperating cargo order and truck allocation. The efficiency of truck collaboration is possible to be realized for transportation enterprises, receiver and sender of cargo.

• Journal of Korean Society of Transportation
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• v.33 no.3
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• pp.247-255
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• 2015

When the new highway is opened, the new highway has alternative or linkage relationship with current highway networks. This change will lead to the different traffic patterns which can also lead to the change of toll revenue in other surrounding highways. This study investigates the change of revenue on the current highway networks caused by the new highway opening under the unified revenue system. Moreover, this study calculates the effectiveness of the revenue fluctuation when the highway system is under controlled by the public or private institution and proposes the meaning of the revenue fluctuation to those institutions. This study also proposes an index of revenue change that could be used to reflect the individual project evaluation and set the priority between multiple projects. Some limitations and future research agenda have also been discussed.

• International Journal of Railway
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• v.4 no.4
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• pp.93-96
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• 2011

The basic element of the EMS suspension is the electromagnet system, which suspends the vehicle without contact by attracting forces to the rails at the guideway. The suspension of a vehicle by attractive magnetic forces is inherently unstable and consequently it is continuously adjusted by the strength of the suspending electromagnet from rail irregularity and bending of the guideway. In order to improve reliable tracking, it needs to get feedback signals without measurement delay time. In this paper the concept of feedback control system with Kalman Filter in EMS is proposed. The input signals in the feedback control system are an air-gap and an acceleration signal. The air-gap signal with noise from the gap sensor is transformed to the filtered air-gap signal y without measurement delay time by using Kalman Filter. The filtered air-gap signal is transformed to a relative velocity and a relative acceleration signal. Then it multiplies these values by gain matrix in order to get the actuator's reference voltage value. The simulation results show that the dynamic responses of the suspension system can be improved by reducing the influence of measurement delay time of air-gap signals.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2009.06a
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• pp.471-474
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• 2009

A Hanbitho, which is a ship to measure maritime transportation system, observes and estimates the maritime transportation system and its signal to be able to receive in our closed sea New GNSS systems are constructed such as GLONASS, GALILEO, QZSS, however, our ships can use SBAS service such as MSAS of Japan. So, it is needed to reconstruct new measuring system to observe and estimate new GNSS and SBAS. In this paper, we propose the upgrade method of Hanbiho measuring system.