• Title/Summary/Keyword: Spliced

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Confined Effect of Concrete Compressive Members Strengthened with Carbon Fiber Laminate (탄소섬유판으로 횡보강된 콘크리트 압축부재의 보강성능)

  • Chung, Lan;Lee, Hee-Kyoung;Kim, Sung-Chul;Yoo, Seong-Hoon;Kim, Joong-Koo
    • Magazine of the Korea Concrete Institute
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    • v.10 no.6
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    • pp.345-352
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    • 1998
  • Compressive strength of concrete compression members strengthend with carbon fiber laminate(CFL) were studied from the test results. Test parameters are spacing, thickness, width, ply and spliced length of carbon fiber laminates. Specimens strength with sheets failed with sudden tensile rupture of the laminate, which indicate very brittle failure mode. Test result shows that closer spacing and to increas thickness of CFL is more effective. But strengthening ratio with 1-ply CFL is more effective than that of specimen with 2-ply CFL. Compressive strength capacity of specimen splied 24cm shows almost similar strength to that of non-spliced specimen. The ultimate load carrying of specimen strengthened with CFL ranges 1.11~1.86 times of that of non-strengthened specimen.

Seismic Performance of HyFo Beam with High Depth-to-SRC Column Connections (춤이 큰 하이브리드 합성보와 SRC기둥 접합부의 내진성능에 관한 연구)

  • Kim, Sung Bae;Jeon, Yong Han;Cho, Seong Hyun;Choi, Young Han;Kim, Sang Seup
    • Journal of Korean Society of Steel Construction
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    • v.29 no.2
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    • pp.135-145
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    • 2017
  • This study is a secondary study that is a cyclic seismic test of High depth hybrid composite beam and column connection after the primary bending strength test of a high depth Hybrid composite beam. Total of 3 seismic test specimens were prepared to cyclic test. The bracket and beam web spliced by high strength bolt and the bracket and beam upper flange was spliced by welding. Test results showed that the seismic strength was higher than the plastic moment($M_p$) in the positive negative moment section, the requirement of composite intermediate moment frame wes satisfied. Therefore, the requirement of intermediate moment frame can be secured by applying the details of connection of this study results.

An Experimental Study on the Precast Segmented PSC Girder with I-Shape and Box-Shape Cross-Section (I형 단면과 BOX형 단면을 갖는 프리캐스트 분절 PSC 거더의 실험적 연구)

  • Kim, Sun-Hee;Lee, Seng-Hoo;Park, Joon-Seok;Cheon, Jinuk;Yoon, Soon-Jong
    • Journal of the Korean Society for Advanced Composite Structures
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    • v.6 no.2
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    • pp.8-16
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    • 2015
  • Prestressed concrete (PSC) is a method in which prestressed tendon is placed inside and/or outside the reinforced concrete member and the compressive force applied to the concrete in advance to enhance the engineering properties of concrete member which is weak under tension. In this paper we suggested the precast PSC girder assembled with segments of portable size and weight at the factory. The segments of precast PSC girder will be delivered and assembled as a unit of PSC girder at the site. Consequently, we suggested new-type of precast segmented PSC girder with different shapes of segment cross-section (i.e., I-shape, Box-shape). To mitigate the problems associated with the field splice between the segments of precast PSC girder anchor system is attached near the neutral axis of the girder and relatively uniform compression throughout the girder cross-section is applied. Prior to the experimental investigation, analytical investigation on the structural behavior of precast PSC girder was performed and the serviceability (deflection) and safety (strength) of the girder were confirmed. In addition, 4-point bending test on the girder was conducted to investigate the structural performance under bending. From the experimental investigation, it was found that the precast PSC girder spliced with 3 and 5 segments has sufficient in serviceability and safety conditions and it was also observed that the point where the segments spliced has no defects and the girder behaves as a unit.

Displacement Ductility Ratio of Reinforced Concrete Bridge Piers with Lap-splices (주철근 겹침이음 비율에 따른 RC교각의 연성능력 평가)

  • Park, Kwang-Soon;Ju, Hyeong-Seok;Shin, Hyun-Mock;Kim, Moon-Kyum
    • Journal of the Earthquake Engineering Society of Korea
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    • v.12 no.6
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    • pp.1-12
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    • 2008
  • As internal and external seismic experiment results, the seismic performance of RC bridge piers is largely dependent on the ratio of lap-spliced bars to all longitudinal reinforcing bars in plastic hinge regions, and confining effects of transverse reinforcements. Capacity and displacement ductility of non-seismically designed existing RC piers are reduced by lap splices in plastic hinge regions. The provision for the lap splice of longitudinal reinforcing bars was not specified in KBDS (Korean Bridge Design Specifications) before the implementation of 1992 seismic design code, but the ratio of lap-spliced bars to all longitudinal reinforcing bars in plastic hinge regions is restricted to 50% in the 2005 version of KBDS. This paper presents a seismic assessment of RC piers at lap-splicing ratios of 0%, 50%, and 100%. Through a comparison of experimental and analytic results of RC piers, we introduce an appropriate ultimate strain of confined concrete in plastic hinge regions with lap-splices, and propose a method for estimating displacement ductility ratios of non-seismically designed existing RC piers using fiber element analysis.

Detection of Spliced Image Using Run-length of Wavelet Coefficients and Statistical Moments (웨이블릿 계수의 런-길이와 통계적 모멘트를 이용한 접합 영상 검출)

  • Kim, Tae-Hyung;Han, Jong-Goo;Park, Tae-Hee;Eom, Il-Kyu
    • Journal of the Institute of Electronics and Information Engineers
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    • v.51 no.5
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    • pp.152-159
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    • 2014
  • In this paper, we introduce a run-length for wavelet coefficients and present a image splicing detection method using the statistical moments for the wavelet run-length. Various pre-processings for the suspicious image are performed to emphasize the discontinuous edges caused by the image splicing. The proposed scheme has the merit that can exploit the various statistical characteristics of the wavelet transform. We extracted up to 72 features, and performed training and testing using SVM(support vector machine). Experimental results showed that the proposed method generates similar detection results compared to the existing methods. In addition, we showed the wavelet domain run-length is useful to detect the spliced image.

Identification of Novel Alternatively Spliced Transcripts of RBMS3 in Skeletal Muscle with Correlations to Insulin Action in vivo

  • Lee, Yong-Ho;Tokraks, Stephen;Nair, Saraswathy;Bogardus, Clifton;Permana, Paska A.
    • Biomedical Science Letters
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    • v.15 no.4
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    • pp.301-307
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    • 2009
  • Whole-body insulin resistance results largely from impaired insulin-stimulated glucose disposal in skeletal muscle. Our previous studies using differential display and quantitative real-time RT-PCR have shown that a novel cDNA band (DD23) had a higher level of expression in insulin resistant skeletal muscle and it was correlated with whole-body insulin action, independent of age, sex, and percent body fat. In this study, we cloned and characterized DD23. The DD23 sequence is part of the 3'UTR region of the RNA binding motif, single stranded interacting protein (RBMS3). We have cloned the full length cDNA for RBMS3 and identified two splice variants. These variants named DD23-L and DD23-S have 15 and 14 exons respectively and differ from RBMS3 in the 3'UTR significantly. Northern blot analyses showed that an ~8.8 kb mRNA transcript of DD23 was predominantly expressed in skeletal muscle and to a lesser extent in placenta, but not in heart, brain, lung, liver, or kidney, unlike RBMS3. Elevated expression levels of these novel alternatively spliced variants of RBMS3 in skeletal muscle may play a role in whole body insulin resistance.

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Displacement Ductility Evaluation of Earthquake Experienced RC Bridge Piers with 2.5 Aspect Ratio (지진을 경험한 형상비 2.5 RC 교각의 내진 변위 연성도 평가)

  • 정영수;박창규;이은희
    • Journal of the Earthquake Engineering Society of Korea
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    • v.7 no.3
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    • pp.79-88
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    • 2003
  • For the construction of PC bridge piers the implementation of 1992 seismic provisions, longitudinal steels were practically lap-spliced in the plastic hinge region. Experimental investigation was conducted ductility of evaluate the seismic earthquake-experienced reinforced concrete columns with 2,5 aspect ratio. Six test specimens were mode with test parameters: confinement ratios, lap splices, and retrofitting FRP materials. They were damaged under series of artificial earthquakes that could be compatible in Korean peninsula. Directly after the pseudo-dynamic test, damaged columns were retested under inelastic reversal cyclic loading simultaneously under a constant axial load, P=0.1f$\_$ck/A$\_$g/. Residual seismic performance of damaged columns was evaluated and compared to that of the corresponding original columns. Test results show that PC bridge piers with lap-spliced longitudinal steels appeared to fail at low ductility. This was due to the debonding of the lap splice, which resulted from insufficient development of the longitudinal steels. The specimens externally wrapped with composite FRP straps in the potential plastic hinge region indicated significant improvement both in flexural strength and displacement ductility.

Experimental Behavior of Reinforced Concrete Column-Bent Piers under Bidirectional Repeated Loading (이축반복하중을 받는 2주형 철근콘크리트 교각의 실험거동)

  • Park, Chang-Kyu;Lee, Beom-Gi;Song, Hee-Won;Chung, Young-Soo
    • Journal of the Earthquake Engineering Society of Korea
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    • v.9 no.1 s.41
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    • pp.17-24
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    • 2005
  • Response of reinforced concrete (RC) column-bent piers subjected to bidirectional seismic loadings was experimentally investigated. RC column-bent piers represent one of the most popular shapes of piers used in Korea highway bridges. Four column-bent piers were constructed in 400 mm diameter and 2,000 mm height. Each pier has two circular supporting columns. These piers were tested under bidirectional lateral load reversals with an axial load of $0.1f_{ck}A_g$. The test parameters included : different transverse reinforcement contents and lap-spliced longitudinal reinforcing steels. Test results indicate that the lap splice of longitudinal reinforcing steels have significantly influenced on hysteretic response of column-bent piers similar to previous test results for single columns with corresponding test parameters. Column capacity was changed with the level of transverse confinement. From the comparison of test result for single column under unidirectional loading, the damage of single column was concentrated on lower plastic hinge region but the damage of column-bent piers was scattered to upper and lower plastic hinge region.

Characterization of Phosphatidylinositol Glycan, Class K (PIGK) Gene and Analysis of Association with Quantitative Traits in Pigs (돼지 Phosphatidylinositol Glycan, Class K (PIGK) 유전자의 동정과 양적형질과의 연관성 분석)

  • Lim, H.T.;Kim, J.H.;Choi, B.H.;Lee, S.H.;Park, E.W.;Kim, T.H.;Cho, I.C.;Oh, S.J.;Lee, J.G.;Jeon, J.T.
    • Journal of Animal Science and Technology
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    • v.47 no.2
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    • pp.167-176
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    • 2005
  • PIGK(phosphatidylinositol glycan, class K) is a subunit of GPI transamidase that cleaves the signal peptide in proproteins and replaces it with GPI. In addition, the structure and synthesis of GPI are critically involved in some of the cellular actions of insulin. Therefore, PIGK would be essential for mammalian development and many specific cellular functions as well as for metabolic activity of insulin associated with GPI. Two types of" full-length cDNAs of porcine PIGK were cloned through RT-PCR and RACE experiments. One is thought to be a normal form(consist of 395 amino acids) and the other is considered as an alternative spliced form(consist of 371 amino acids) which contains additional 63 bps in intron 7. Since a stop codon was contained within the insertion, the spliced form has a shorter coding sequence than that of normal form. A missense mutation (T314I) in exon 6 was detected and used for genotyping to estimate association with the growth and fat deposition traits for 545 $F_2$ animals(Korean native boars ${\times}$ Landrace). From the PCR-RFLP analysis using HpyCH4III, CT genotype showed highly significant relationship(P< 0.01) with carcass fat contents.

Evaluation of the Effect of Coupler on the Ductility of Rebar by Uniaxial Tensile Test (1축 인장시험을 통한 커플러가 철근 연성도에 미치는 영향 평가)

  • Woo, Tae-Ryeon;Lee, Jong-Han;Cheung, Jin-Hwan;Jung, Chi-Young
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.22 no.1
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    • pp.90-98
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    • 2018
  • Recently, various reinforced concrete joints have been used in reinforced concrete structures. Therefore, it is important to grasp the tensile properties of the spliced rebar. In this study, uniaxial tensile tests were conducted on Grade 60 D22(#7), D29(#9), and two kinds of couplers manufactured according to ASTM A615 standard for evaluating ductility of coupler joints. The strain was measured using an image processing method more accurate and capable of measuring at various points freely. As the result of uniaxial tensile test, it was possible to calculate the stress-strain relationship and the longitudinal strain distribution according to the stress stages and it was founded that the average strain becomes lower as more occupying the coupler joint portions in the same gauge length. In addition, the empirical equations are proposed to account for the effect of the length of the coupler on the ultimate strain and the rupture strain.