• Proceedings of the Korean Institute of Building Construction Conference
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• 2004.05a
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• pp.97-100
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• 2004

In-place curing box for specimens is used to cure the compressive strength specimens for control in place concrete. The box if composed of insulating chamber maintaining 20$\pm$3$^{\circ}C$ of temperature, in this paper, strength and temperature history of specimens cured at in plate curing box are investigated to verify field applicability. According to test results, air temperature at measured time shows large temperature variation and below zero, whereas, inside temperature of in place curing box maintains within 20$\pm$3$^{\circ}C$ due to temperature control function. For curing condition. temperature of specimens cured at outside shows large temperature deviation. specimens lured at in-place curing box is not affected by outer temperature.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.412-419
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• 2011

With an increase in rail traffic, developing activities around structures of railway have been expanded. Inevitably, the changes to cross though sub-structures of railway have been getting increased. However, this situation affects on the safe operation of trains. Generated wheel load makes on the result in settlement on roadbed and damages on track materials. Therefore, via the numerical analysis were carried out for the box structure and subground using FEM analysis program called. Visual FEA/Geo 4.19. Parametric studies were performed by changing soil depth above box structure constructed in railway embankment. A standard live load was applied to simulate loads from train. Through this study, a minimum required soil depth above subground box structure was recommended based on deformation and stresses in concrete railway system.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.10
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• pp.2352-2358
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• 2013

In this paper, we designed and implemented black box terminal with wireless communication function and cloud server for more efficient usage of black box video. Our system can store and manage all vehicle black box videos so public institutions can select videos with various conditions such as object, time-based and location based like integrated CCTV management system.

• Proceedings of the Korea Concrete Institute Conference
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• 2002.10a
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• pp.625-630
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• 2002

PSC box girder is widely used in a domestic bridge and overpass, etc., therefore, the design and construction technique for the PSC box girder is developing day by day. Even if it were so, however, the design for anchorage zone in PSC box girder has depended on common sense and empirical results. And it is the current situation that the designer has difficulty due to inadequacy of provisions in the domestic design code and lack of understanding for behavior of anchorage zone. Besides, the design based on Leonhardt's method is being done in general, but the design may be various even for the same structure because of the difference in a way of applying. In this paper, therefore, anchorage zone in PSC box girder bridge is analyzed and designed by using strut-tie model. Adequacy for the application of strut-tie model is verified by comparison with the way used in current design practice, and this study presents that strut-tie model can be a rational and an economical design than current design methods.

• Korean Journal of Computational Design and Engineering
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• v.21 no.4
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• pp.443-452
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• 2016

This paper proposes a method for expensive black box optimization using radial basis functions (RBFs). The proposed algorithm is a computational strategy that uses a RBF model approximating the expensive black box function to predict an optimum. First, a RBF-based approximation technique is introduced and a sampling plan for estimation of the black box function is described. Then the proposed algorithm is explained, which presents the pseudo-codes for implementation and the detailed description of each step performed in the optimization process. In addition, numerical experiments will be given to analyze the performance of the proposed algorithm, by investigating computation accuracy, number of function evaluations, and convergence history. Finally, geometric distance problem as application example will be also presented for showing the algorithm applicability to different engineering problems.

• Steel and Composite Structures
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• v.23 no.5
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• pp.611-621
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• 2017

This paper presents an investigation on the fire resistance of high strength fiber reinforced concrete filled box columns (CFBCs) under combined temperature and loading. Two groups of full-size specimens were fabricated. The control group was a steel box filled with high-strength concrete (HSC), while the experimental group consisted of a steel box filled with high strength fiber concrete (HFC) and two steel boxes filled with fiber reinforced concrete. Prior to fire test, a constant compressive load (i.e., load level for fire design) was applied to the column specimens. Thermal load was then applied on the column specimens in form of ISO 834 standard fire curve in a large-scale laboratory furnace until the set experiment termination condition was reached. The test results show that filling fiber concrete can improve the fire resistance of CFBC. Moreover, the configuration of longitudinal reinforcements and transverse stirrups can significantly improve the fire resistance of CFBCs.

• 제어로봇시스템학회:학술대회논문집
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• 1993.10b
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• pp.185-190
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• 1993

The POSTECH Hand adopting coupled tendon driven technique with planar two fingers is developed. The hand is designed to emulate principal motions of the human hand which has two and three joints respectively. Its kinematic parameters are determined through a parameter optimizing technique to aim at improving the isotropy of fingertip motions with new criterion functions of design. For the control of the hand, tension and torque control algorithms are developed. Based on the virtual stiffness concept, we develop the stiffness control method of a grasped object with redundant finger mechnism and investigate experimentally.

• Proceedings of the Korea Concrete Institute Conference
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• 2001.05a
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• pp.521-526
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• 2001

Box-culvert is very important structure used almost every road construction. However this is treated very simple structure in design and construction. So many crack such as nonstructural crack has been occurred. This crack is very harmful on durability of concrete. In this study, thermal crack, one of the nonstructural crack, of box-culvert controled by using rapid-strength belite cement concrete. In this process, not only heat of hydration and thermal stress but also material mechanics properties and characteristics of durability were tested. and same model box-culvert using OPC concrete is constructed in same condition for comparison.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.41 no.5
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• pp.38-43
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• 2009

A conservation corrugated box for storing document archives was developed. The specifications of the double-walled E-flute corrugated conservation box were modified from those of the Library of Congress, USA. The Photographic activity test (PAT) of ISO 18916 was used to ensure protection of the archival contents from adverse effects of the container itself. Accelerated aging was conducted to evaluate the conservative properties of the box components. Atomic force microscopy was also used to evaluate changes in the cellulose surface due to accelerated aging.

• Proceedings of the Korea Concrete Institute Conference
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• 2001.11a
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• pp.591-596
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• 2001

In case of continuous steel box-girder bridges, the magnitude of the longitudinal tensile stress on concrete in internal support is larger than the tensile strength of concrete. In this paper, the parametric study was performed to present the effective magnitude of the longitudinal prestress for reducing the longitudinal tensile stress to decrease under the tensile strength of concrete. The parametric study is conducted with changing the steel box-girder section and the span length of bridge. Three dimensional finite element analyses are conducted with ABAQUS program. The behavior of the steel box-girder bridge with prestress is investigated through experimental works on a analogous steel box-girder bridge model, and their results are compared with those of analytical studies.