• Proceedings of the KSR Conference
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• 2008.06a
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• pp.1628-1636
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• 2008

Construction of concrete slab track is trending to increase gradually in national and international for reduction in track maintenance cost and secure of ride comfort. But elastic pad becomes superannuated due to repeated train operation. After all, it brings change of pad stiffness and it could directly act on track and bridge as load transmission and impact force. In this study, we carried out laboratory test changing pad stiffness after making a model of 15m bridge and laying concrete slab track. Also, we carried out static and dynamic behaviors test(stress, natural frequency, damping ratio, vibrational acceleration, deflection) of bridge and track and experimentally analyzed them by change of elastic pad stiffness on rail fastener.

• Proceedings of the KSR Conference
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• 2009.05a
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• pp.1047-1053
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• 2009

This paper examined an applicability of optimum algorithm to develope an electric railway pole foundation automated design system. Based on the optimization theory that considered subgrade and bearing capacity characteristics, decided an optimum section of electric railway pole foundation. In this research, Optimum algorithm used the feasible direction method in structural analysis and design efficiently. Design variables are considered geometric properties and anchor bolt area of the electric railway pole foundation as optimum construction cost. Constraints are considered settlement., overturning and activity of foundation. And, also composed flexural and shearing strength. According to optimum analysis result., optimization theory is available more economical design comparing with railway pole foundation that is constructed by current standard drawing, and applicability verified in automated design system development.

• Management & Information Systems Review
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• v.19
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• pp.199-221
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• 2006

The purpose of this study is to expand businesses' adoption of the Enterprise Resource Planning System (E.R.P.S.). In order to accomplish the objective, the following conditions need to be fulfilled. 1) Clearness of the goal and expected effect of E.R.P.S. adoption 2) Definiteness of the extent of E.R.P.S. construction 3) The management's will to E.R.P.S. adoption If the E.R.P.S is adopted, the following effects are expected. 1) Speedy quality decision-making is possible. 2) Time taken from the order of the product to its release can be curtailed (from 40days to 10days). 3) Time taken for the development of the product can be shortened (from 24 months to 10 months). 4) Cost reduction is possible by using necessary information in real time.

• Proceedings of the KSR Conference
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• 2004.10a
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• pp.1007-1013
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• 2004

A new type of girder named as Steel-Confined Prestressed Concrete Girder(SCP Girder) has been developed, which is composed of concrete, steel plate, and prestressing tendon. This girder may maximize structural advantages of these components, therefore it can be used to construct the middle or long span bridge with low-height girder. To verify the propriety of design, structural safety, and applicability of this girder, static load test was carried out. In this study, a design program was developed for practical design of railway bridge using SCP girder. And to verify the applicability of SCP girder to railway bridge, structural performance and economic efficiency based on the construction cost were compared with conventional railway bridges.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.05b
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• pp.441-444
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• 2005

Our country has experienced variations in temperature as belong to the area of the continental climate that shows four significant seasons. These occur immense difficulty on the period, cost, quality of construction. As the hydration of cement processes, the strength of concrete is developed. In order to improve the quality of concrete, various conditions including temperature and humidity should be maintained appropriately and concrete itself should be cured sufficiently. In the early age, the strength of concrete is developed remarkably. However, the hydration is accelerated too much in high temperature or delayed too much in low temperature, so the quality can be changed and It can fail to get the objective strength. This paper aims to offer the data, necessary to the quality control handbook.

• Proceedings of the Korean Geotechical Society Conference
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• 2009.09a
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• pp.564-569
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• 2009

Due to the uneasy controllable qualities of the substructures such as pile and foundation, which are laid on underground, geotechnical engineers have applied conservative criteria to them. Therefore, the specification criterion of cast-in-situ concrete pile, which allows only one fourth of the compressive strength of structural capacity, has forced geotechnical designers to consider the most uneconomical design regardless of satisfying the grade of quality-control, required performance, construction cost and so on. Thus, in this study, we proposed the less conservative criteria on the strength of concrete pile, based on the experimental testing results of cast-in-situ concrete piles.

• Proceedings of the Korean Geotechical Society Conference
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• 2008.10a
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• pp.754-759
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• 2008

Recently, the construction of buildings and large bridges has been increasing rapidly causing foundation structure growing larger then before, especially in the use of large size cast-in-place piles. Barrette Pile will usually be used at the site where diaphragm wall is the retaining wall to save time and cost in mobilization of equipments. This study uses bi-directional loading test data obtained from two different sites to observe the bearing capacity and displacement characteristics of barrette pile. Numerical analysis of the test is done by using commercial 3D computer program and the interface effect and capacity of the pile as well as displacement characteristics of the pile is verified.

• Journal of Hydrogen and New Energy
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• v.14 no.3
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• pp.195-206
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• 2003

Polymer electrolyte membrane fuel cells(PEMFC) are very interesting power source due to high power density, simple construction and operation at low temperature. But they have problems such as high cost, improvement of performance and effect of temperature. This problems can be approached using mathematical models which are useful tools for analysis and optimization of fuel cell performance and for heat and water management, in this paper, transient model consists of various energy terms associated with fuel cell operation using the mass and energy balance equation. And water transfer in the membrane is composed of back diffusion and electro-osmotic drag. The temperature calculated by transient model approximately agreed with the temperature measured by experiment in constant current condition.

• Proceedings of the KIEE Conference
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• 2000.07b
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• pp.1414-1416
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• 2000

In the future light rail vehicle is more attractive than subway, because of construction time and cost. For light rail vehicle are two types of traction motors. one is traditional rotating type and the other is linear motor. Linear motor is not better in consideration of efficiency and power factor than rotating type. But the motor needs no translation equipment for linear motion and with them can be constructed low floor vehicle. In this paper will be designed a linear induction motor with consideration of operational condition and analysed operating characteristics using FEM program and equivalent circuit.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2010.04a
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• pp.218-221
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• 2010

발주자는 건설 프로젝트의 주요 의사결정을 초기단계에 내리게 되므로 정확한 예산을 예측하는 것이 중요하다. 그러나 건설 프로젝트의 대형화, 복잡화 그리고 건설산업계의 새로운 패러다임인 BIM(Building Information Modeling)의 등장에도 불구하고, 초기단계에서 정확한 공사비를 예측할 수 있는 표준화된 산출방법이 없어 아직까지도 대부분의 설계사무소에서는 실시설계단계에서 확정된 설계안에 따른 견적을 이용하며 초과된 비용에 대해 통합품질을 저해하는 행위를 통해 조정하고 있다. 초기단계에서 보다 정확한 공사비를 예측하므로써 발주자는 의사결정을 함에 있어 올바른 판단을 내릴 수 있으며, 이 단계에서 발생한 정보를 활용하여 이후 단계에도 유용하게 쓰일 수 있을 것이다. 본 연구에서는 발주자 의사결정 지원시스템 상에서 BIM기반으로 개략공사비를 산출할 수 있는 프로세스를 제안한다.