• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.20 no.1
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• pp.41-47
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• 2006

This paper presents harmonic evaluation of an IAT(Intra Airport Transit) system in Incheon International Airport. It will be used for electric vehicles with 80[kW] per car produced by Mitsubishi Heavy Industries Ltd, and which is constructed with SIV(Static Inverter), VVVF controller and two induction motor. The vehicles operated in the IAT system can be treated as rapidly changing DC loat and at a feeding substation, 3-phase electric power is transferred to DC 750[V] by rectifier. Since vehicles are changing continuously, the voltages for the load fluctuate in the IAT system, and moreover, the voltage fluctuation generates high-order harmonics. It results the difficulty in maintaining power quality in KEPCO systems' side. The power quality of the IAT system in Incheon International Airport is evaluated using PSCAD/EMTDC simulator in the paper. The THD(Total Harmonic Distortion) of voltages and TDD(Total Demand Distortion) of currents, indices are calculated for the IAT system using the results of PSCAD/EMTDC dynamic simulation.

• Journal of the Korean Operations Research and Management Science Society
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• v.38 no.3
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• pp.37-50
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• 2013

The purpose of this study is to determine the indicators and the criteria to classify types of train delays of high-speed rail in South Korea. Types of train delays have divided into the chronic delays and the knock-on delays. The Indicators based on relevance, reliability, and comparability were selected with arrival delay rate of over five minutes, median of arrival delays of preceding train and following train, knock-on delay rate of over five minutes, correlation of delay between preceding train and following train on intermediate and last stations, average train headway, average number of passengers per train, and average seat usages. Types of train delays were separated using the Ward's hierarchical cluster analysis. The criteria for classification of train delay were presented by the Fisher's linear discriminant. The analysis on the situational characteristics of train delays is as follows. If the train headway in last station is short, the probability of chronic delay is high. If the planned running times of train is short, the seriousness of chronic delay is high. The important causes of train delays are short headway of train, shortly planned running times, delays of preceding train, and the excessive number of passengers per train.

• Journal of Korean Tunnelling and Underground Space Association
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• v.15 no.6
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• pp.625-635
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• 2013

Although the TBM method is mainly adopted in overseas market including the Europe, etc, the method scarcely adopted in domestic market. For highly enhancing applications of the TBM method for railway, It is needed to select the optimal cross-section considering design elements of civil engineering and aerodynamic effects. Also, it is needed to establish plan of proper section as well as reviewing aerodynamic effects and consideration about civil engineering elements such as length of tunnel, speed of railway, height of whole lines and size of utility tunnel, etc. Even though it should be recently considered high-speed railway tunnels and required to be standard establishments in aerodynamic reviews, it is being applied to be criteria of inconsistent pneumatic analysis owing to be not related with domestic standards. In this study, therefore, we are willing to establishment of domestic and foreign aerodynamic standards and investigate correlation between optimal cross-section and aerodynamic effects of TBM railway tunnels.

• Journal of the Korean Society of Systems Engineering
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• v.7 no.2
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• pp.7-11
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• 2011

A high-speed railway system represents a typical example of large-scale multi-disciplinary system, consisting of subsystems such as rolling-stock, electrical hardware, electronics, control, information, communication, civil technology etc. The system design and acquisition data of the large-scale system must be the subject under strict configuration control and management. Systems engineering technology development project for Korea next generation High-speed Electric Multiple Unit (HEMU) system in progress is a national large system development project that is not only a large-size and complex but also multi-disciplinary in nature. Therefore, all stakeholders must understand and share the functional and performance requirements of HEMU throughout its life-cycle phases. Also in the test and evaluation phase, all systems requirements must be verified. In 2011, the prototype train manufacturing will be completed. It will do test run on the commercial line and all systems requirements are verified until 2012. For the system verification, the test and evaluation process have to be established before the test trial run. Using a systems engineering tool, the system design database(SDD) with requirements traceability and development process management in the course of the development have to be established. This paper represents the test and evaluation process development based on the SEMP(Systems Engineering Management Plan) developed in the design stage. The test and evaluation process is refined and updated in comparison to the design stage one. The test and evaluation process consists of procedure, test and evaluation method and schedule. So through this process, it is defined that each systems requirements is verified on which test and about what time.

• Journal of the Korean Society for Railway
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• v.12 no.6
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• pp.983-988
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• 2009

When the railway vehicle passing through curves & transitions, the running speed must improve by proposing the practical standard about maximum running possibility speed of each section on existing line considering running safety. In this paper, when the railway vehicle passing through curves of actual track conditions (Namsunghyun-Chungdo up & down lines), the effect that has influence on running safety is examined to devise the high speed of vehicle which passing through curves which risk of derailment is high. The running safety analysis is performed that running speed by curve radius improves 5-20% compared with existing speed under actual track conditions. In result of the running safety analysis, in case the speed condition is fewer than 15% compared with existing speed, the derailment coefficient and unloading ratio are within acceptable level. so we could confirm possibility of speed improvement on the whole Namsunghyun-Chungdo up & down lines.

• Journal of the Korean Geotechnical Society
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• v.19 no.1
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• pp.103-110
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• 2003

The development of reinforced-roadbed material in substitute for existing roadbed is necessary to protect its failure from the dynamic stress and vibration caused by the traveling of the high-speed and heavy trains. The water quenched blast furnace slag having potential hydraulic reactivity is one of the materials in substitute for soil reinforced-roadbed. We carried out the study of basic properties of roadbed material using Portland cement and CSA(calcium sulphoaluminate) as the activator for the evaluation of its application. As the result of the strength test, this material satisfied design criterion for reinforced-roadbed. Optimum mixing ratio of this reinforced-roadbed material was 15 ~ 17.5 percent of cement and 2.5 percent of CSA by weight of the blast furnace slag. Especially, as permeability is above $10^{-3}$cm/sec, this material proved to have functions of both reinforced roadbed and drainage layer.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2004.11a
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• pp.20-25
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• 2004

On July $18^{th}$, 2003, Incheon International Airport Corporation(lIAC) signed the Construction Management Service Contract with KIDS consortium (composed of Kun-Won Eng., ITM Corp, Do-Hwa Eng, Space Croup) for the $2^{nd}$ phase construction protect consists of landfill, $\#3$ runway, remote Concourse, IAT, BHS, cargo terminal, etc scheduled to be finished by the end of 2008. KIDS dispatched qualified engineers to the Construction Management Division of IIAC for providing technical assistance to IIAC members to pursue project goals in tulle. within budget with appropriate quality level to build one of leading hul] airports for the Northeast Asia legion in the $21^{st}$ century. The work scope covers upgrading various project procedures and related computer programs, cost and schedule control, design supervision for building design including support systerns such as HVAC, fire protection, elevators and escalators, boarding bridges, electrical and communication systems, and technical support for IAT/BHS, QA/QC, field test and inspection, start-up and commissioning, etc. The purpose of this paper is to introduce the major activities of the Construction Management Services performing at the IIA project for your reference.

• Journal of computational fluids engineering
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• v.17 no.1
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• pp.36-43
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• 2012

When a high-speed train passes an underground station, large pressure waves are generated due to the piston effect. These pressure waves can cause the problems of vibration and noise as well as the ear discomfort of passengers at the underground station. This work numerically analyzed the pressure wave generation and propagation in an high-speed railway underground station, and the optimal location for vent shafts was studied to improve the passenger comfort by reducing the magnitude of the pressure wave and its rate of change. The evolution of pressure field in the underground station was calculated using a CFD(Computational Fluid Dynamics) software(Fluent), where the axis-symmetric two-dimensional model verified by Wu was used. And this study is applied to modelling of the underground station and the tunnel from Daegok station A-line of GTX(Great Train Express). From the result, we can have a conclusion that the role of vent shafts respectively were different according to the position in and out the underground station. Also Vent shaft in the underground station widely reduced pressure magnitude. And vent shaft out underground station reduced initial pressure peak value. Double vent shafts installed at tunnel toward station entrance and inside of the tunnel are the most efficient to reduce pressure. and pressure reduction increases according to the number of vent shaft.

• Journal of the Korean Society for Railway
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• v.13 no.5
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• pp.500-503
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• 2010

Until now, the track circuit with railroad which is a part of an electrical circuit wad used only for the detection of the train location, but as train speed is up to be higher, in order to overcome the limits of ground signal system the railway signal system has changed from the ground signal system to a cab signal system. The power source of the track circuit has also changed from a direct current or a high voltage impulse to an alternating current with high frequency which is a part of the audio frequency. To improve the maintenanability and according to the environment condition, the railway roadbed is rapidly changed to the ferroconcrete roadbed. In case of a track circuit to use an alternating current with high frequency as power source at a ferroconcrete roadbed, the characteristic of the track circuit is brought on a change from a loss of the magnetic combination instead of a leakage current from electric insulation which was caused by the reinforcing iron pod with lattice shape for durability. This paper is shown the influence and the loss of the signal current at AF track circuit on a ferroconcrete in the simulation sheets and presented a proposal for the preventive method from reduction of signal current.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.35 no.8
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• pp.941-949
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• 2011

When a railway vehicle passes through curves & transitions, the running speed must be improved by setting limits on the maximum running speed in each section of the conventional line(Dongdaegoo-Namsunghyun) considering derailment safety. Our goal is to improve the maximum running speed of railway vehicle that passes through curves & transitions where there is a high risk of derailment. We examined the influence on the derailment safety when the railway vehicle passes through curves of actual track conditions (Dongdaegoo-Namsunghyun up and down lines). We performed the derailment safety analysis by increasing the running speed on curve radius by 5%.20% compared to existing speed under actual track conditions.