• Title/Summary/Keyword: Flexible Wall

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The Effects of the Boundary Shapes on the Structural-acoustic Coupled System (다양한 경계 형상에 따른 구조-음향 연성계의 음향특성)

  • 김양한;서희선
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.14 no.8
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    • pp.718-725
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    • 2004
  • If a wall separates the bounded and unbounded spaces, then the wall’s role in transporting the acoustic characteristics of the two spaces is not well defined. In this paper, we attempted to see how the acoustic characteristics of two spaces are really affected by the spatial characteristics of the wall. In order to understand coupling mechanism, we choose a finite space and a semi-infinite space separated by the flexible or rigid wall and an opening. A volume interaction can be occurred in structure boundary and a pressure Interaction can be happened in the opening boundary. For its simplicity, without loosing generality, we use rather simplified rectangle model instead of generally shaped model. The source impedance is presented to the various types of boundaries. The distributions of pressure and active intensity are also presented at the cavity- and structure-dominated modes. The resulting modification, shifts of modal frequencies and changing of standing wave patterns to satisfy both coupled boundary conditions and governing equations, are presented.

CHEMICAL COMPATIBILITY OF SOIL-BENTONITE CUT-OFF WALL FOR IN-SITU GEOENVIRONMENTAL CONTAINMENT

  • Inui, Toru;Takai, Atsushi;Katsumi, Takeshi;Kamon, Masashi;Araki, Susumu
    • Proceedings of the Korean Geotechical Society Conference
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    • 2010.09c
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    • pp.135-139
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    • 2010
  • A construction technique to install the soil-bentonite (SB) cut-off wall for in-situ geoenvironmental containment by employing the trench cutting and re-mixing deep wall method is first presented in this paper. The laboratory test results on the hydraulic barrier performance of SB in relation to the chemical compatibility are then discussed. Hydraulic conductivity tests using flexible-wall permeameters as well as swell tests were conducted for SB specimens exposed to various types and concentrations of chemicals (calcium chloride, heavy fuel oil, ethanol, and/or seawater) in the permeant and/or in the pore water of original soil. For the SB specimens in which the pore water of original soil did not contain such chemicals and thus the sufficient bentonite hydration occurred, k values were not significantly increased even when permeated with the relatively aggressive chemical solutions such as 1.0 mol/L $CaCl_2$ or 50%-concentration ethanol solution. In contrast, the SB specimens containing $CaCl_2$ in the pore water had the higher k values. The excellent linear correlation between log k and swelling pressure implies that the swelling pressure can be a good indicator for the hydraulic barrier performance of the SB.

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Seismic Analysis of liquid Storage Structures Using 2-Dimensional Fluid Elements (이차원 유체요소를 이용한 유체 저장구조물의 지진해석)

  • 김영석;윤정방;김재민;김진웅
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1991.10a
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    • pp.49-56
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    • 1991
  • Seismic analysis of liquid storage structures is carried out by utilizing 2-dimensional fluid elements of a general purpose structural analysis computer program(ADINA), The present analysis focuses on the effects of the wall flexibility and the sloshing of the free water surface. Due considerations are given to the facts that the fluid has no shear resistance and the free surface motion is subjected to the gravity effect. To validate the present method using 2-dimensional fluid elements, the results of several example cases are compared with those by the Housner's approach for rigid wall case, and with those by the Eulerian formulation for flexible wall case.

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A Study on the Categorization of Interface for the Flexibility in the Wall System of Long Life Housing (장수명 공동주택의 가변성 확보를 위한 벽체 인터페이스 유형화 연구)

  • Bahc, Yo Han;Choi, Young Ho;Kim, Sung Wan
    • KIEAE Journal
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    • v.8 no.3
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    • pp.37-42
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    • 2008
  • The purpose of this study was to comprehend specific characteristic of interface and present the standardized interface of Long Life Housing, which could be obtained by the total and various approaches. With this in mind we analyzed related studies of interface through previous studies, and based on the analysis we created standardized factors of categorization in view of characteristic of interface. Using these factors, we can determine whether the interface could be used systematically in Long Life Housing. And as these were presented in the form of Key Map for expedite the synthetic understanding of interface, we could easily reconize types of interface. Especially, we only dealt the wall of flexible interface of Long Life Housing. Throughout systemizing and standardizing works, we can expedite the understanding of interface of Long Life Housing and finally, we want to make basic data used for date base of interface which can be available for Long Life Housing.

Analysis of Flexible Media Behavior by Dynamic Elastica (Dynamic Elastica에 의한 유연매체의 거동해석)

  • Hong, Sung-Kwon;Jee, Jung-Geun;Jang, Yong-Hoon;Park, No-Cheol;Park, Young-Pil
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.15 no.2 s.95
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    • pp.206-212
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    • 2005
  • In many machines handling lightweight and flexible media, such as magnetic tape drives, xerographic copiers and sewing machines, the media must transit an open space. It is important to predict the static and dynamic behavior of the sheets with a high degree of reliability. The nonlinear theory of the dynamic elastica has often been used to a nonlinear dynamic deflection model. In this paper, the governing equation is derived and simulated by the finite difference method. The parametric cubic curve is applied for defining the guide shape. The dynamic contact conditions suggested by Klarbring is used to predict the direction of the flexible media according to the initial velocity and the friction coefficient. The analysis is also compared to the conventional model, showing that after contacting a $45^{\circ}$ wall, the directions of flexible media of two models are different.

Evaluation of Residential Performance in Commercialization of Flexible Unit Infra Free Residential for Disaster (재난 시 대응을 위한 Flexible-Unit형 인프라 프리(임시)주거의 성능평가)

  • Park, Beungyong;Cho, Jinkyun;Jeong, Yongdae;Lee, Wonhak
    • Journal of the Korean Solar Energy Society
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    • v.38 no.6
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    • pp.37-49
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    • 2018
  • In this paper a new kind of unit-prefabricated building is shown. The unit-prefabricated buildings are made up living unit, energy unit, water unit. The design trend implemented the energy insulation, solar PV panels, energy storage system which are maintained for zero energy buildings. We made a prototype for zero energy flexible residential unit. The first step, we was evaluated the physical performance, insulation, airtightness. The second step, we was evaluated energy performance building to design heating and cooling system to combined PV system. As a results, the insulation performance wall was $0.18W/(m^2{\cdot}K)$. The results of air-tightness was 12.13 ACH@50 (1/h). The building energy demand ratings and solar energy generation has the possible to be ballanced.

A Study on Plan Structure Types and Characteristics of Wall Formation in Art Museum Exhibition Spaces

  • Lee, Jong-Sook
    • Architectural research
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    • v.13 no.3
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    • pp.3-10
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    • 2011
  • The Characteristics of space are determined by several factors; however, the element that determines the physical characteristic of floors, walls, and ceiling is the structure. This study constructs a wall to analyze the direct effect that the layout of an exhibition wall has on the element of the wall followed by the structural process and visibility of descriptive analysis and examples of art museums that the shift from a perceptional wall to an experiential wall affected circulation. For elements and formation methods of the wall, first, it is made up of open and closed type exhibition spaces, and it can give abundance in qualitative space rather than a quantitative aspect. Secondly, the directivity of space changes according to the development of the visible axis, thus, directly affects the change in visibility. Thirdly, the difference between spatial structure and visual structure is the difference between the visual axis and spatial structure. The wall formation type followed by the combination method, the simple visible structure, which is the type that possesses the simple combination (Room, Zone, Cluster), repeatedly uses the same size of units of space that is orderly and has few spatial axes and the classification of simple type and simple cluster type, which has few visible axes, also exists. Also, with the complex structure of the maze type it displays the reiterated form of the cluster, which is the space with disorderly combination and has much visible axes and spatial axes. Also, these can be divided into three types: 1) Maze Cluster Type, 2) Cross Road Type, and 3) Open Flexible Type. These wall types lead the various changes in circulation, and even each of the arrangement qualities of the exhibitions should be researched according to its exhibition place type.

Stability Evaluation of Green Wall System due to Facing Rigidity (전면벽체 강성에 따른 그린월 시스템의 안정성 평가)

  • Park, Si-Sam;Kim, Hong-Taek;Kim, Seung-Wook;Kim, Yong-Eon
    • Journal of the Korean Geosynthetics Society
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    • v.5 no.3
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    • pp.9-15
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    • 2006
  • The Green Wall system is one of segmental concrete crib type earth retaining wall. Green wall is constructed as procedures that lay the front stretchers, rear stretchers and headers then making a rigid body through harden filled soil of interior cell. Recently, Green Wall method is applied in variable cutting ground construction because of advantage which minimize to cut base ground. In case of Green Wall method is constructed with soil nail method, expect that total system stability will increase more than flexible facing because of facing stiffness is big. However, in this case of design, facing stiffness is not considered so that is poor economy. Hence, in this study, stability increasing effect of total system analyze about that soil nail method is constructed with rigidity facing like a Green Wall method. In present study, laboratory model tests was performed for analysis on stability increasing effect of total system about changing stiffness of facing. LEM analysis conducted for evaluation on safety factor of total system sliding that facing condition changed.

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Analysis of the Segmental Reinforced Retaining Wall Behavior by Field Monitoring (현장계측을 통한 블럭식 보강토 옹벽의 거동분석)

  • Shin, Eun Chul;Lee, Chang-Seup
    • Journal of the Korean Geosynthetics Society
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    • v.3 no.1
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    • pp.3-15
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    • 2004
  • Geogrid reinforced soil structures with segmental block facing have been increased since 1990's, because of the convenience of installation and the flexible appearance. In this paper, the behavior of the segmental reinforced retaining wall was analysed with the results of field monitoring. The height and length of reinforced wall are 12m and 25m, respectively. The field measurement equipments are horizontal and vertical earth pressure cells, settlement plate, strain gauge, inclinometer, and displacement pin. Based on the field monitoring, the horizontal earth pressure was approximately 0.3times higher than that of the theoretical method and the maximum tensile strength of reinforcement was 26.2kN/m. The displacement of facing wall was 23mm at the point of 7.1m height of the wall and toward the wall facing. The results of the study indicate that the segmental reinforced retaining wall is in a stable condition because of good compaction & reinforcement effects, and long period of construction time. Finally, the computer program of SRWall is very useful tool to design the segmental reinforced retaining wall.

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Highly Flexible Touch Screen Panel Fabricated with Silver Nanowire Crossing Electrodes and Transparent Bridges

  • Jeon, Youngeun;Jin, Han Byul;Jung, Sungchul;Go, Heungseok;Lee, Innam;Lee, Choonhyop;Joo, Young Kuil;Park, Kibog
    • Journal of the Optical Society of Korea
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    • v.19 no.5
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    • pp.508-513
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    • 2015
  • A capacitive-type touch screen panel (TSP) composed of silver nanowire (AgNW) crossing electrodes and transparent bridge structures was fabricated on a polycarbonate film. The transparent bridge structure was formed with a stack of Al-doped ZnO (AZO) electrodes and SU-8 insulator. The stable and robust continuity of the bridge electrode over the bridge insulator was achieved by making the side-wall slope of the bridge insulator low and depositing the conformal AZO film with atomic layer deposition. With an extended exposure time of photolithography, the lower part of the SU-8 layer around the region uncovered by the photomask can be exposed enough to the UV light scattered from the substrate. This leads to the low side-wall slope of the bridge insulator. The fabricated TSP sample showed a large capacitance change of 22.71% between with and without touching. Our work supplies the technological clue for ensuring long-term reliability to the highly flexible and transparent TSP made by using conventional fabrication processes.