• Title/Summary/Keyword: Bridge light

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A Case Study of Stability of Bridge Abutment Using the Light Banking Material(EPS) (경량성토재(EPS)를 이용한 교량 교대의 안정성 검토)

  • Chang, Yong-Chai
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.40 no.5
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    • pp.80-90
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    • 1998
  • The EPS construction method-one kind of the load reducing methods-utilizes the EPS blocks, ultra-light materials whose unit weight is about 1/100 of soils and has been applied to many soft ground sites. It needed 3,000 days to get the 90% degree of the consolidation for the case of 12m high soil embankments on the 30m thick soft clayey foundations. The N value of SPT at this deposit was less than 5. The pack drain was installed to promote the radial consolidations. Although staged embankments were planned, designers failed to get a sufficient stability of the foundation ground. Therefore, the EPS fill method was selected to reduce the load and the construction period. EPS blocks(D-20 model) replaced the upper part of the soil embankments. These complex embankments reduced the ground settlement and the construction period. The possibility of lateral movements of the bridge abutments was checked and the design scheme was reviewed.

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Static Behavio in Weak Axis of FRP Bridge Deck Filled With a Foam (폼 충전 FRP 바닥판의 약축방향 정적거동 특성)

  • Zi Goang-Seup;Kim Byeong-Min;Hwang Yoon-Koog;Lee Young-Ho
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2006.04a
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    • pp.906-913
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    • 2006
  • The failure mechanism of a hollow bridge deck which is made of glass fiber reinforced polymer(GFRP) is investigated using both experiments and analysis. While the load-displacement behavior of the deck in the transverse direction shows a strong nonlinearity even in its initial response with relatively small magnitude of loads. In order to imporve the structural behavior of the deck in the transverse direction, we suggested that the empty space of the bridge deck is filled with a foam and investigated experimentally the static behavior of the orthotropic bridge deck which is made from GFRP and polyurethane foam. It is found that although the elastic modulus of the foam compared to that of the GFRP is about the order of $10^{-3}$, the structural behaviors in the weak axis such as nominal strength, stiffness, etc. are greatly improved. Owing to the low mass density of the foam used in this study, the bridge deck is still light enough with the improved structural properties.

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Experiments on Local Behavior of GFRP Composite Deck for Pedestrian Bridges (보도교용 복합소재 바닥판의 국부거동시험)

  • Na, Doo-Hoon;Hong, Kee-Jeung;Lee, Sung-Woo
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2008.04a
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    • pp.84-89
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    • 2008
  • Glass fiber reinforced composite decks have high-strength, light-weight and high durability. The composite decks having vertical snap-fit connections are designed for pedestrian bridges and their structural behavior are studied. Especially in this paper, local behavior of the developed composite deck for pedestrian bridge is verified by both analysis and experiment.

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DPWM Control of Triple Active Bridge Converter for loss reduction at light load (경부하 손실 저감을 위한 트리플 액티브 브리지 컨버터의 DPWM 제어)

  • Lee, Sungmin;Cho, Younghoon
    • Proceedings of the KIPE Conference
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    • 2020.08a
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    • pp.298-299
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    • 2020
  • Triple Active Bridge 컨버터의 경부하 조건에서의 효율 개선을 위해 브리지의 듀티와 위상을 동시에 변경하는 Dual Pulse Width Modulation(DPWM)기법을 적용하였다. 기존의 위상천이기법은 제어가 단순한 장점이 있으나 경부하 조건에서 효율이 급격히 감소하는 단점이 존재한다. 따라서 본 논문에서는 DPWM 방식을 통해 경부하 조건의 효율 개선을 위한 각 브리지 듀티, 위상각을 분석하였고, 시뮬레이션을 통해 이를 검증하였다.

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A Study of the High Voltage Power Supply using a Sixfold Voltage-Multiplying Rectifier (6배압 정류기를 이용한 고전압 전원장치에 관한 연구)

  • Ahn, Tae-Young;Gil, Yongl-Man
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.29 no.2
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    • pp.19-26
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    • 2015
  • This paper presents design, fabrication, and performance evaluation of a high voltage power supply for Carbon Nano Tube-based planar light sources. The proposed power supply employs an LLC resonant half-bridge converter and a sixfold voltage-multiplying rectifier. Steady-state characteristics of the voltage-multiplying rectifier are analyzed and used to derive the input-to-output voltage conversion ratio of the power supply. The input-to-output frequency response characteristics of the LLC tank circuit are analyzed and utilized in designing a proto-type power supply which produces a 15 KV output using a 400 V input source. The high-voltage transformer is fabricated using a sectional bobbin structure with an epoxy impregnation, in order to provide sufficient insulation for high voltage operations. The performance of the proposed power supply is confirmed with stable and reliable operations at the 15 KV output from no load to nominal load conditions. The proposed power supply is well suited as an electric ballast required stable operations of Carbon Nano Tube-based planar light sources.

Seismic performance of a fiber-reinforced plastic cable-stayed bridge

  • Hodhod, Osama A.;Khalifa, Magdi A.
    • Structural Engineering and Mechanics
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    • v.5 no.4
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    • pp.399-414
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    • 1997
  • This paper presents an investigation into the seismic response characteristics of a proposed ligh-weight pedestrian cable-stayed bridge made entirely from Glass Fiber Reinforced Plastics(GFRP). The study employs three dimensional finite element models to study and compare the dynamic characteristics and the seismic response of the GFRP bridge to a conventional Steel-Concrete (SC) cable-stayed bridge alternative. The two bridges were subjected to three synthetic earthquakes that differ in the frequency content characteristics. The performance of the GFRP bridge was compared to that of the SC bridge by normalizing the live load and the seismic internal forces with respect to the dead load internal forces. The normalized seismically induced internal forces were compared to the normalized live load internal forces for each design alternative. The study shows that the design alternatives have different dynamic characteristics. The light GFRP alternative has more flexible deck motion in the lateral direction than the heavier SC alternative. While the SC alternative has more vertical deck modes than the GFRP alternative, it has less lateral deck modes than the GFRP alternative in the studied frequency range. The GFRP towers are more flexible in the lateral direction than the SC towers. The GFRP bridge tower attracted less normalized base shear force than the SC bridge towers. However, earthquakes, with peak acceleration of only 0.1 g, and with a variety of frequency content could induce high enough seismic internal forces at the tower bases of the GFRP cable-stayed bridge to govern the structural design of such bridge. Careful seismic analysis, design, and detailing of the tower connections are required to achieve satisfactory seismic performance of GFRP long span bridges.

Fiber Reinforced Inlay Adhesion Bridge

  • Cho, Lee-Ra;Yi, Yang-Jin;Song, Ho-Yong
    • The Journal of Korean Academy of Prosthodontics
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    • v.38 no.3
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    • pp.366-374
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    • 2000
  • FRC/ceromer system provides the clinician with a durable, flexible, and esthetic alternative to conventional porcelain fused to metal crowns. FRC is the matrix which is silica-coated and embedded in a resin matrix. The ceromer material which is a second generation indirect composite resin contains silanized, microhybrid inorganic fillers embedded in a light-curing organic matrix. FRC/ceromer restoration has a several advantages: better shock absorption, less wear of occluding teeth, translucency, color stability, bonding ability to dental hard tissues, and resiliency. It has versatility of use including inlay, onlay, single crown, and esthetic veneers. With adhesive technique, it can be used for single tooth replacement in forms of inlay adhesion bridge. In single tooth missing case, conventional PFM bridge has been used for esthetic restoration. However, this restoration has several disadvantages such as high cost, potential framework distortion during fabrication, and difficulty in repairing fractures. Inlay adhesion bridge with FRC/ceromer would be a good alternative treatment plan. This article describes a cases restored with Targis/Vectris inlay adhesion bridge. Tooth preparation guide, fabrication procedure, and cementation procedure of this system will be dealt. The strength/weakness of this restoration will be mentioned, also. If it has been used appropriately in carefully selected case, it can satisfy not only dentist's demand of sparing dental hard tissue but also patient's desire of seeking a esthetic restorations with a natural appearance.

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Luminous Characteristics of Bridge's Nightscape across the Han River (조명물리량 측면에서 본 교량의 야간경관 평가)

  • Hwang, Tae-Yon;Kim, Jeong-Tai
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.20 no.1
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    • pp.7-18
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    • 2006
  • This study aims to analyze the illumination effects of bridges across the Han River. For the purpose, 8 bridges were selected. Field survey and measurements were performed, and the physical values such as luminance, color temperature and chromaticity were measured by Radiant Imaging Prometric 1400 Color. The results of the study are as follows; (1) Metal halide lamp, sodium lamp and LED(Light Emitting Diode) of various colors, are used in illuminating the bridges and create color contrasts and color changing by color filters. (2) Luminance contrast of the illuminated bridges affects 'modeling' and 'spare sense' of bridges, and it might improve people's preference and impression. (3) Color temperature of the illuminated bridges is influenced by 'color of bridge', 'material of bridge' and, 'color temperature and color of light sources'. (4) 'Structure of bridges' and 'luminaires' influence on the physical feature of the bridges. Especially, illumination of the bridges shows resemblant patterns by 'structure of bridges'.

The Effects of Corpus Use on Learning L2 Collocations of Light Verbs and Nouns

  • Yoshiho Satake
    • Asia Pacific Journal of Corpus Research
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    • v.4 no.2
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    • pp.41-55
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    • 2023
  • In data-driven learning (DDL), learners explore a corpus to understand vocabulary and grammar. Although many studies have emphasized the role of DDL in second language (L2) acquisition, L2 light verbs have been largely under-explored. To bridge this gap, this study focused on the learning outcomes of L2 light verbs among 29 intermediate-level Japanese university students. The research zeroed in on six prevalent light verbs in English: "make," "do," "take," "have," "give," and "get." Over nine weeks, the participants engaged with verb-noun collocations using worksheets that juxtaposed Japanese translations of the target collocations with their English equivalents, with the verbs omitted. With the aid of Wordbanks Online, they filled in the blanks and constructed accurate sentences. Before this activity, a 20-minute tutorial was given to the participants on how to interpret the concordance lines. The effectiveness of the DDL method was evaluated using pre-tests, immediate post-tests, and delayed post-tests. The results showed that DDL significantly improved the participants' knowledge of the target collocations of light verbs and nouns; the post-test and delayed post-test scores were significantly higher than the pre-test scores. The results showed that, overall, DDL contributed to memorizing the collocations of light verbs and nouns; however, DDL had different effects on the memorization of collocations across different light verbs. The extent of work on the worksheet is not the only factor in its retention, and observing concordance lines may promote learners' memorization of light-verb collocations.

A study on the solution suggesting and the problem investigating of spatial designing through the axis of circulation in the extension of general hospital - A case study : medical college's hospital of Hanyang University - (종합병원의 증축과정에서 동선 중심축 형성을 통한 공간디자인의 문제점 도출과 해결안 제시에 관한 연구 -한양대학교 의과대학 부속병원의 사례-)

  • Kim, Kyu Sung;Lee, Jung Man
    • Journal of The Korea Institute of Healthcare Architecture
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    • v.9 no.1
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    • pp.7-15
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    • 2003
  • Contemporary hospital has more and more extension because the growth and change of hospital has to respond the various needs. For expanding, the sky bridge(sky walk) becomes one of the method to interconnect two or more buildings on the air. Sometimes the designers don't know exactly how the sky bridge works after construction. Beyond the role of interconnecting two buildings, the role of sky bridge is transformed the main axis of pedestrian in the whole hospital organization. This scope of analysis is about the sky bridge of Hanyang University hospital. The first method is the investigation of the utilization in this time. The second is the analysis of design drawings got form the designing of the past(1994-1998). From this analysis, the conclusions are followings.;The designer who wants to apply the sky bridge should more consider about, 1) how the sky bridge impacts the whole spatial system such as the pedestrian, patients, physicians, service's facilities etc. 2) what the inside of sky bridge has something such as natural light, ventilation, and the height, depth, width of aisle, the sign for seeking orientation. etc. In future the research relating sky bridge should be studied some hospital as well as one hospital for comparing the characteristics of the concepts and organizations

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