• Journal of the Korea institute for structural maintenance and inspection
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• v.23 no.1
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• pp.85-93
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• 2019

Structural performance and serviceability of precast deck system are mostly determined by connection details between precast decks. Particularly, since the bridge deck is under repeated loads such as traffic loads, fatigue behavior and performance of joints should be investigated. In this study, a two-girder continuous composite bridge specimen was fabricated using the asymmetric ribbed loop joints, and static and fatigue load tests were conducted to evaluate the structural behavior and the crack pattern of the bridge deck. From the test results, the proposed precast deck system resulted in sufficient fatigue performance and failure strength. Therefore, the proposed precast deck system can be applied to the connection part of precast decks effectively.

• Magazine of the Korea Institute for Structural Maintenance and Inspection
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• v.19 no.3
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• pp.43-49
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• 2015

• 한국방재학회:학술대회논문집
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• 2009.02b
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• pp.80.1-80.1
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• 2009

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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• v.30 no.5
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• pp.51-55
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• 2001

일본의 도시바는 세계 최초로 독자적인 나선형 압축기구의 채용으로 밸브 없이 연속적인 압축이 가능한 헬리컬 압축기를 개발하였다. 이 압축기는 저소음, 저진동, 우수한 에너지 절약성, 콤펙트한 구조가 특징이다. 여기서는 상품개발 배경과 헬리컬 압축기의 구조, 특징등을 소개하고자 한다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.07a
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• pp.93-96
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• 2004

다층의 산화물 박막 구조를 갖는 coated conductor의 장선 제조를 위해서는 연속 증착 공정이 필요하다. 본 연구에서는 RABiTs와 IBAD 공정을 사용한 texture template을 사용하였으며, 금속 테잎을 연속적으로 이동하면서 증착할 수 있는 박막증착 장치(PLD, sputtering, evaporation)를 구축하여 PVD 방법으로 coated conductor를 제조하였다. $CeO_2/YSZ/Y_2O_3$의 완충층을 sputtering 과 evaporation을 이용하여 2축배향성을 가지는 NiW 위에 연속적으로 증착하였다. YBCO 초전도층은 연속 PLD 방법으로 증착하고, Tc, Ic, XRD, SEM을 통해 그 특성을 분석하였다. 그 결과 RABiTS template을 사용하여 Ic가 34A/cm(@77K)인 0.4m 길이의 coated conductor를 제조하였다. IBAD template를 사용하여 Ic가 34A/cm(@77K)인 0.5m길이의 coated conductor를 제조하였고, Jc는 $1.2MA/cm^2$ 이였다.

• Journal of the Korea institute for structural maintenance and inspection
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• v.10 no.4
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• pp.145-154
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• 2006

This paper presents a method to enhance the load carrying capacity for a two-span continuous steel-concrete composite beam strengthened with external tendons. The tendon is placed at the bottom of steel beam where the positive bending moment occurs. This results in the reduction of the negative bending moment as well as the positive bending moment. This paper describes the procedure to determine the number of tendon and the initial tendon force for the target rating factor in the rating factor equation. An example beam is given to demonstrate the proposed procedure, and it validity is confirmed.

• Transactions of the Korean Society of Mechanical Engineers
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• v.16 no.6
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• pp.1021-1029
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• 1992

A rational and straightforward method is introduced for developing continuum models of large platelike periodic lattice structures based on energy equivalence. The procedure for developing continuum plate models involves the use of existing well-defined finite element matrices for the easy calculation of strain and kinetic energies of a repeating cell, from which the reduced stiffness and mass matrices are obtained in terms of continuum degrees- of-freedom defined in this paper. The equivalent continuum plate properties are obtained from the direct comparison of the reduced matrices for continuum plate with those for lattice plate. The advantages of the present continuum method are that it may be applied to arbitrary lattice configurations and may give most diverse equivalent continuum plate properties including all kinds of coupling, while other methods may give only limited structural properties. To evaluate the continuum method developed in this paper, free vibration analyses for both of continuum and lattice plates are conducted. Numerical results show that the present continuum method gives very reliable structural and dynamic properties compared to other well-recognized methods.

• Journal of the Korea institute for structural maintenance and inspection
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• v.15 no.1
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• pp.77-84
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• 2011

This study is to develop nonlinear analysis algorithm for transfer matrix method, which can be applied to continuous beam analysis. Gauss-Lobatto integral rule is adopted and the transfer matrix is derived from stiffness matrix. In the transfer matrix method, the system equation has a constant number of unknowns regardless of number of D.O.F. Therefore, the transfer matrix method has computational efficiencies not only in linear elastic analysis but also in nonlinear analysis. To verify the developed method, the analysis results of several examples are compared with commercial code in moment-curvature, moment-displacement and load-displacement relation.

• Journal of IKEEE
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• v.23 no.2
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• pp.461-468
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• 2019

A continuous-time Delta-Sigma ADC has various benefits; it does not require an explicit anti-aliasing filter, and it is able to handle wider-band signals with less power consumption in comparison with a discrete-time Delta-Sigma ADC. However, it inherently needs to sample the signal with a high-speed clock, necessitating a complex decimation filter that operates at high speed in order to convert the modulator output to a low-rate high-resolution digital signals without causing aliasing. This paper proposes a continuous-time Delta-Sigma ADC architecture that employs pulse-width modulation and shows that the proposed architecture lends itself to a simpler implementation of the decimation filter using a lookup table.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2011.06a
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• pp.291-291
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• 2011

소나의 특성상 취득되는 데이터는 1차원 배열의 연속으로 구성된다. 2차원의 경우는 순차적인 방향으로 연속배열로 간단히 구성되지만 3차원의 경우는 특정한 방향성을 가지기 어렵다. 실제로 소프트웨어를 구현하며 작성된 데이터구조와 획득된 데이터와 실제 공간상에서 발견되는 목표물에 대해서 소개한다.