• Journal of Auto-vehicle Safety Association
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• v.7 no.1
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• pp.13-19
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• 2015

Recently, Child safety has become one of the issue with Q10 dummy representing large child. The objective of this paper was to evaluate performance of three child restraints system (backless booster, high-back booster and without booster) by changing D-ring location in the rear seat. Sled tests were carried out with a Q 10 in 64km/h frontal impact. Before the dynamic sled tests, we assessed dummy positioning with difference in CRS types and height adjustment positions. Dynamic sled test results indicated that there is different performance of CRS types and belt routing. These test results will use as base line data for development CRS safety performance for Q 10.

• Proceedings of the Korean Nuclear Society Conference
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• 1995.05a
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• pp.771-776
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• 1995

Tensile and J-R tests were carried out to estimate the effects of dynamic strain aging(DSA) on SA106Gr.C piping steel. Tensile tests were performed under temperature range RT to $400^{\circ}C$ md strain rates from $1.39{\times}10^{-4}\;to\;6.95{\times}10^{-2}/s$. Fracture toughness was tested in the temperature range RT to $350^{\circ}C$ and load-line displacement rates 0.4 and 4mm/min. The effects of DSA on the tensile properties were clearly observed for phenomena such serrated flow, variation of ultimate and yield stress, and negative stram rate sensitivity. However, the magnitude of serration and strength increase by DSA was relatively small. this may be due to high ratio of Mn to C. In addition, crack initiation resistance, Ji and crack growth resistance, dJ/da were reduced in the range of $200-300^{\circ}C$, where DSA appeared as serrated flow and UTS hardening. The temperature corresponding to minimum fracture resistance was shifted to higher temperature with increasing loading rate.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2002.10a
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• pp.169-176
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• 2002

This paper is concerned with development of an enhanced quadratic Mindlin plate bending element. The behavior of the proposed plate element is further improved by the coupled use of non-conforming displacement modes, the selectively reduced integration scheme, and the assumed shear strain fields. The improvement may be attributable to the fact that the merits of these improvement techniques are merged in the formation of the new element in a complementary manner. The proposed quadratic finite element passes the patch tests, does not show spurious mechanism, and does not produce shear locking phenomena even with distorted meshes. It is shown that the element produces reliable solutions through numerical tests for standard benchmark problems. It is also noted that the element is applicable to transient dynamic analysis of Mindlin plates.

• Journal of Ocean Engineering and Technology
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• v.2 no.1
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• pp.59-70
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• 1988

This paper presents the results of motion tests of a moored semi-submersible platform in regular waves. To investigate the effects of mooring system on the motion characteristics, the tests were performed under the various mooring conditions in regular head and beam waves. Two types of mooring system were employed: one is composed of soft springs and the other is of chains. In the case of chains the pretensions were varied to investigate the dynamic effects of mooring forces as well as the motion responses of the semi-submersible. The motion responses and mooring tensions were measured and analyzed by the double amplitude method. The measured motion responses were also compared with the results of calculation from three-dimensional potential theory. Finally, the dynamic behaviors of mooring chains were studied.

• Journal of the Korea Institute of Military Science and Technology
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• v.16 no.1
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• pp.81-88
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• 2013

This paper describes the fundamentals, design, realization and test results of a BPSK(Bi Phase Shift Keying) transceiver for the direction finding proximity fuze sensor for anti-aircrafts or air missiles. The BPSK transceiver for the direction finding fuze sensor has been designed to detect a moving target by Doppler signal processing with the code correlation method and to distinguish direction by comparing received powers of each Doppler signal from adjacent three receiving antennas. The electrical and ESS(Environmental Stress Screening) tests of the BPSK transceiver showed satisfactory results and target detection and direction finding performances proved to be successful through dynamic operation tests by 155 mm gun firing.

• Structural Engineering and Mechanics
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• v.52 no.3
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• pp.541-558
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• 2014

A 1/4-scale two-bay eight-storey reinforced concrete frame was tested on shaking table. Initial shaking table tests were carried out through a set of real seismic excitations to investigate the seismic behavior of the RC frame. Subsequently, the damaged frame was repaired using epoxy injection technique, and then subjected to the tests with the same records. The purpose of this study was to investigate experimentally the dynamic characteristics, cracking pattern and lateral inter-story stiffness of RC frames using epoxy injection technique. The test results indicate that epoxy-injection technique appears to be a satisfactory method for repairing earthquake-damaged structure.

• Journal of Korean Association for Spatial Structures
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• v.9 no.1
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• pp.47-52
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• 2009

In this study, it is demonstrated by a pseudo dynamic earthquake response tests that combination of semi-rigid partial-strength using the high performance-high strength bolts and inter-story hysteretic damper system creates a fairly good structural system that satisfies not only the serviceability requirement under moderate earthquakes but unexpected failure of damper system.

• Journal of Welding and Joining
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• v.24 no.3
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• pp.55-59
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• 2006

This paper is concerned with a study on cyclic bending load of bus folding door pillar including adhesive bonding and spot welding. Three specimen types were used such as spot welding, I-type adhesive bonding and M-type adhesive bonding in this study. The tensile-shear tests were carried out to evaluate the tensile-shear strength of these three specimen types. Also four-point bending tests were carried out to evaluate the static and dynamic bending load. From the results, using adhesive bonding has a better effect on the static and dynamic bending load than using spot welding. Therefore, manufacturing better structural products can be expected by applying hybrid welding using adhesive and spot welding to those.

• Steel and Composite Structures
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• v.19 no.2
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• pp.385-403
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• 2015

This paper presents the status improvement of an old damaged deck type rural road steel truss bridge through the modal parametric study after partial retrofitting. The dynamic and static tests on bridge were carried out as in damaged state and after partial retrofitting. The dynamic testing on the steel bridge was carried out using accelerometers under similar environmental conditions with same speed of the moving vehicle. The comparison of the modal parameters i.e., frequency, mode shape mode shape curvature, modal strain energy, along with the deflection parameter are studied with respect to structural analytical model parameters. The status up gradation for the upper and downstream truss obtained was different due to differential level of damage in the bridge. Also after retrofitting the structural elemental behavior obtained was not same as desired. The damage level obtained through static tests carried out using total station indicated further retrofitting requirement.

• Earthquakes and Structures
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• v.16 no.6
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• pp.691-704
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• 2019

This study simulates the responses of large-scale bridge piers under pseudo-dynamic tests to investigate the performance of four types of numerical models that consider the nonlinear behavior of the pier and the rocking behavior of the footing. In the models, beam-column elements with plastic hinges are used for the pier, two types of foundation models (rotational spring and distributed spring models) are adopted for the footing behavior, and two types of viscous damping models (Rayleigh and dashpot models) are applied for energy dissipation. Results show that the nonlinear pier model combined with the distributed spring-dashpot foundation model can reasonably capture the behavior of the piers in the tests. Although the commonly used rotational spring foundation model adopts a nonlinear moment-rotation property that reflects the effect of footing uplift, it cannot suitably simulate the hysteretic moment-rotation response of the footing in the dynamic analysis once the footing uplifts. In addition, the piers are susceptible to cracking damage under strong seismic loading and the induced plastic response can provide contribution to earthquake energy dissipation.