• Proceedings of the Korean Institute of Building Construction Conference
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• 2009.11a
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• pp.225-229
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• 2009

International construction market has been open to other countries, and it derives the development of our overseas construction industry quantitatively as well as qualitatively. Until now, the major companies have an absolute majority in the overseas construction market, and the small and medium enterprises have had difficulty to get a leadership in the international construction market because of the lack of the technical expertise and the capital strength. Especially in the Middle East Asia, our construction companies has touched off a boom, so our market share also has grown, which derived from the up toward ratchet oil prices and a worldwide boom in real estate development. The small and medium enterprise minority have recognition that the overseas construction market is the major company's native territory. But Data from the existing researches and many statistics indicate the most companies tend to underestimate the capacity and international competitiveness of the small and medium enterprises. As a matter of fact, hundreds of small and medium enterprise cut a conspicuous figure in overseas market. Consequently, it is indispensable to overcome the international financial crisis by revitalizing our overseas construction industry which obtains excellent results in international market. this study suggested the ways to expand overseas bonding capacity of Korean financial institution. This study proposed the Korean government to allow Construction Guarantee (former Korea Construction Financial Cooperative) to deal with foreign exchange so that Construction Guarantee will underwrite the overseas construction bond.

• Journal of the Korea Construction Safety Engineering Association
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• s.48
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• pp.60-63
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• 2009

• 한국가스학회:학술대회논문집
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• 2000.09a
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• pp.101-109
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• 2000

• Journal of the korean Society of Automotive Engineers
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• v.4 no.2
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• pp.24-34
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• 1982

In order to improve the digging load capacity of a domestic excavator model. computer aided design(CAD) technique was applied to the optimum design of the excavator boom. From this study, the digging load capacity of both the bucket cylinder and the dipperstick cylinder could be made about same and the overall digging load capacity could be increased by about 50%, also, the computer program package developed in this study can be flexibly applied to the design of other construction machines by changing and/or adding a few subprograms and the input data.

• Steel and Composite Structures
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• v.16 no.2
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• pp.187-201
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• 2014

A new through-beam connection system for a concrete filled steel tube column to RC beam is proposed. In this connection, there are openings on the steel tube while the reinforced concrete beams are continuous in the joint zone. The moment and shear force at the beam ends can be transferred to column by continuous rebar and concrete. The weakening of the axial load and shear bearing capacity due to the opening of the steel tube can be compensated by strengthening steel tube at joint zone. Using this connection, construction of the joint can be made more convenient since welding and hole drilling in situ can be avoided. Axial compression and reversed cyclic loading tests on specimens were carried out to evaluate performance of the new beam-column connection. Load-deflection performance, typical failure modes, stress and strain distributions, and the energy dissipation capacity were obtained. The experimental results showed that the new connection have good bearing capacity, superior ductility and energy dissipation capacity by effectively strengthen the steel tube at joint zone. According to the test and analysis results, some suggestions were proposed to design method of this new connection.

• Journal of Korean Society of Steel Construction
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• v.9 no.1 s.30
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• pp.51-63
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• 1997

Highly curved steel-box bridges are usually constructed as ramp structures for the highway interchange and metropolitan elevated highway junction, but a number of these bridges are deteriorated and damaged to a significant degree due to heavy traffic. The main objective of the study is to develop a practical reliability-based assessment of safety and residual load carrying-capacity of existing curved steel-box ramp bridges. In the paper, for the realistic assessment of safety and residual load carrying-capacity of deteriorated and/or damaged curved steel-box bridges, an interactive non-linear limit state model is formulated based on the von Mises's combined stress yield criterion. It is demonstrated that the proposed model is effective for the assessment of reliability-based safety and the evaluation of residual load carrying-capacity of curved steel-box bridges. In addition, this study comparatively shows the applicability of various reliability analysis methods, and suggests a practical and effective one to be used in practice.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2010.05a
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• pp.25-27
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• 2010

Helical steel piles are being widely used in foundation for the buildings in urban areas because of their high compressive and tensile capacities. Helical steel piles have many advantages; ease installation, a vibration-free and low level of noise process, and so on. However, the most researches are about the capacity of helical steel piles under uplift condition. Therefore, this paper focuses on the capacity under compressive loading according to the soil condition. The bearing capacity of helical steel piles varies with the diameter of the helix and shaft and the bearing area of helical steel piles is not always identical with the sum of helix and shaft area due to the difference of each bearing mechanism. Therefore, the experiment with the parameters of the ratio of helix and shaft diameter and soil condition will be carried out to survey the effective helix area under a given soil condition for the bearing capacity of helical steel piles.

• Progress in Superconductivity and Cryogenics
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• v.7 no.1
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• pp.37-41
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• 2005

This paper describes the construction scheme of new distribution system using HTS(High Temperature Superconducting) power equipments such as cable, transformer and FCL(fault current limiter). At present, one of the most serious problems in distribution power system, especially for metropolitan complex city, is to obtain the ROW for cable line routes, space for downtown substations and satisfy the environmental protection caused by NIMBY phenomena. Unfortunately, it is expected that this situation will get more and more worse. As the HTS technology to apply in power system Is developed, HTS cable utilizing mass-capacity characteristic can be a useful countermeasure to overcome this problem. This paper describes the application methodology of 22.9kV HTS cable with low-voltage, mass-capacity characteristics replacing the 154kV conventional cable. By applying 22.9kV HTS cable, the HTS transformer with higher capacity for the reduction of space and transformer numbers of downtown substation is necessary. Also, if the leakage Impedance of HTS transformer is same as or lower than that of conventional transformer, the fault current of 22.9kV bus will increase because the HTS transformer capacity is larger than that of the conventional transformer. This means the parallel application of HTS-FCL to reduce the fault current in addition to the HTS cable and transformer can be necessary. With the basic construction scheme of new distribution system, this paper describes the future study points to realize this new distribution system using HTS equipments.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.25 no.7
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• pp.418-426
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• 2013

With advantages of open spaces and existing HVAC facilities, subway station, if unexpected disastrous situation happens on the ground, can be used as a temporary safe place for evacuees. The main objective of this study is to establish a guideline on estimating evacuation capacity of the subway station and evaluating levels of service of evacuation for officials to control the situation. This guideline includes available spaces of the station, capacity of sanitary fixtures, and total number of passengers, etc. In this paper, we first analyzed the number of passengers of SMRT (Line 5~Line 8) during AM peak hour and then evaluated the number of passengers using toilets at that time. In addition, we calculated the seating capacity of subway stations on SMRT using the difference between the actual number of toilets and the estimated number of ones from the occupancy time of each toilet.

• Journal of Korean Society of Steel Construction
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• v.12 no.2 s.45
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• pp.209-219
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• 2000

Concrete Filled steel Tube(CFT) Column has an excellent structural capacities in accordance with an interaction effect between the steel tube and concrete. Recently, CFT structure has been focussed on a structural system for a high-rise buildings. The purpose of this study is to evaluate a strength and deformation capacity of CFT square columns subjected to constant axial and cyclic lateral load. The test parameters are diameters to thickness ratio of steel tube, axial load ratios, concrete strengths, load applying types and whether or not filled concrete. Total sixteen specimens are fabricated to clarify the energy absorbtion capacity of CFT columns. Experimental results are summarized for maximum strength, initial stiffness and deformation capacity.