• Title/Summary/Keyword: inner structure

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A Study on the Compressive Characteristics of Inner Structure Bonded Sheet in the Thickness Direction (접합판재의 두께 방향 압축 특성에 대한 실험 및 연구해석)

  • Cho, K.C.;Kim, J.Y.;Chung, W.J.;Kim, J.H.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2006.05a
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    • pp.300-303
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    • 2006
  • Sandwich panel with inner structure is expected to find many applications because of high stiffness to mass ratio. However, low resistance to the pressure in the thickness direction may become a weak point in the forming process. Two pyramid type designs for inner structure are considered. For the resistance characteristics in the thickness direction, finite element simulations are carried out. For one design, experimental results are provided. It is shown that simulation can give a reasonable agreement with experiment. The reasons for the discrepancy are discussed mainly in the geometrical viewpoint. It is observed that most of deformation depends on bending mode. Two designs are compared using simulation.

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Temporal and Spatial Variation of Zooplankton Community Structure Post Construction of Saemangeum Dyke (새만금 해역에서 방조제 건설에 따른 동물플랑크톤 군집의 변화)

  • Lee, Chang-Rae;Kang, Hyung-Ku;Noh, Jae-Hoon
    • Ocean and Polar Research
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    • v.31 no.4
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    • pp.327-338
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    • 2009
  • Zooplankton community structure was investigated in the Saemangeum region in March, May, July and October of 2007 and 2008 in order to understand the potential effect of post construction of Saemangeum dyke on their temporal and spatial distribution. Mean abundance of zooplankton in the inner and outer area of the dyke, except for dinoflagellate Noctiluca scintillans, ranged from 173 to 15,830 ind.m$^{-3}$, showing higher variability in the inner area compared to the outer area. Zooplankton abundance was higher in the outer area than the inner area in 2007, and vice versa in 2008. In the inner area of the dyke, zooplankton abundance was the highest in May 2007 and March 2008. In the outer area of the dyke, abundance was the highest in October 2007 and July 2008. Brackish species such as Tortanus derjugini and Pseudodiaptomus inopinus were dominant prior to construction of the dyke, and appeared less frequently in the inner area. Marine zooplankton taxa such as juvenile hydromedusa, and calanoid copepods Acartiahongi and Paracalanus parvus s.l. dominated both areas of the dyke. In CCA analysis, zooplankton community structure in the inner and outer area was similar in March and May, but different in July and October. Temperature, salinity and COD were important environmental factors affecting zooplankton community structure. These results suggest that zooplankton community structure in the inner and outer area of Saemangeum dyke are significantly affected by whether the sluice gates are closed or open.

Topology Optimization of Shell Structures Using Adaptive Inner-Front(AIF) Level Set Method (적응적 내부 경계를 갖는 레벨셋 방법을 이용한 쉘 구조물의 위상최적설계)

  • Park, Kang-Soo;Youn, Sung-Kie
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2007.04a
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    • pp.157-162
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    • 2007
  • A new level set based topology optimization employing inner-front creation algorithm is presented. In the conventional level set based topology optimization, the optimum topology strongly depends on the initial level set distribution due to the incapability of inner-front creation during optimization process. In the present work, in this regard, an inner-front creation algorithm is proposed. in which the sizes. shapes. positions, and number of new inner-fronts during the optimization process can be globally and consistently identified by considering both the value of a given criterion for inner-front creation and the occupied volume (area) of material domain. To facilitate the inner-front creation process, the inner-front creation map which corresponds to the discrete valued criterion of inner-front creation is applied to the level set function. In order to regularize the design domain during the optimization process, the edge smoothing is carried out by solving the edge smoothing partial differential equation (PDE). Updating the level set function during the optimization process, in the present work, the least-squares finite element method (LSFEM) is employed. As demonstrative examples for the flexibility and usefulness of the proposed method. the level set based topology optimization considering lightweight design of 3D shell structure is carried out.

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Inner disk properties of a Class I young stellar object revealed by IGRINS

  • Lyo, A-Ran;Kim, Jongsoo;Byun, Do-Young;Kang, Jihyun
    • The Bulletin of The Korean Astronomical Society
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    • v.40 no.2
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    • pp.35.4-36
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    • 2015
  • Gaseous inner disks are the main controller of the final structure of planetary systems as well as the building place of planets, especially of terrestrial planets. However, the inner disk of <5AU is still difficult to be spatially resolved even at the closest star forming regions. Resolving velocity structure in the disk with high resolution infrared spectroscopic study is the best approach to study the inner disk at this moment. Here, we present the IGRINS (Immersion GRating INfrared Spectrometer) result of the Class I young stellar object, ESO Ha 279a, in the Serpens molecular cloud region. IGRINS has a resolving power of R=40,000, corresponding to the velocity resolution of 7 km/s at K-band, which is perfect to study the hot inner disk structure. We report that NaI and CO overtone emission lines are indeed good tracers of the rotating inner warm disk tracing from ~0.04 to ~7AU of this source. We also report the disk properties using other emission lines.

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Design Safety Analysis of $9\%$ Nickel Steel Structure in Inner Tank Storage System (내부탱크 저장 시스템에서 $9\%$ 니켈강재 구조물의 설계 안전성에 관한 연구)

  • Kim Chung Kyun;Choi Dong Yul
    • Journal of the Korean Institute of Gas
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    • v.5 no.4 s.16
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    • pp.49-55
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    • 2001
  • This paper presents the design safety analysis of the inner tank structure, which is manufactured by 9 percent nickel steel sheets in the full containment type LNG storage tank. The FEM computed results indicate that top girder and several stiffener rings of the inner tank play an important role for controlling the deformation and stress intensity of the inner tank structure. The hydrostatic pressure due to cryogenic fluids gave more influential to the deformation of the inner tank wall compared with that of a cryogenic temperature of $-162^{\circ}C$. But, the deformation and stress of the inner tank. which is produced by the buckling loads, are very small because the external load is not applied to the top of the inner tank. This indicates the role of top girder and stiffener rings of the inner tank model is not important in full containment LNG storage tank.

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Cochlin-cleaved LCCL is a dual-armed regulator of the innate immune response in the cochlea during inflammation

  • Rhyu, Hyeong-Jun;Bae, Seong Hoon;Jung, Jinsei;Hyun, Young-Min
    • BMB Reports
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    • v.53 no.9
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    • pp.449-452
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    • 2020
  • The inner ear is a complex and delicate structure composed of the cochlea and the vestibular system. To maintain normal auditory function, strict homeostasis of the inner ear is needed. A proper immune response against infection, thus, is crucial. Also, since excessive immune reaction can easily damage the normal architecture within the inner ear, the immune response should be fine regulated. The exact mechanism how the inner ear's immune response, specifically the innate immunity, is regulated was unknown. Recently, we reported a protein selectively localized in the inner ear during bacterial infection, named cochlin, as a possible mediator of such regulation. In this review, the immunological function of cochlin and the mechanism behind its role within inner ear immunity is summarized. Cochlin regulates innate immunity by physically entrapping pathogens within scala tympani and recruiting innate immune cells. Such mechanism enables efficient removal of pathogen while preserving the normal inner ear structure from inflammatory damage.

Fabrication and Static Bending Test in Ultra Light Inner Structured and Bonded(ISB) Panel Containing Repeated Inner Pyramidal Structure (피라미드 형상의 내부구조를 가지는 초경량 금속 내부구조 접합판재의 제작 및 정적 굽힘실험)

  • Jung Chang Gyun;Yoon Seok-Joon;Lee Sang Min;Na Suck-Joo;Lee Sang-hoon;Ahn Dong-Gyu;Yang Dong-Yol
    • Journal of the Korean Society for Precision Engineering
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    • v.22 no.6 s.171
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    • pp.175-182
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    • 2005
  • Inner structured and bonded panel, or ISB Panel, as a kind of sandwich type panel, has metallic inner structures which have low relative density, because of their dimensional shape of metal between a pare of metal skin sheets or face sheets. In this work, ISB panels and inner structures formed as repeated pyramidal shapes are introduced. Pyramidal structures are formed easily with expanded metal sheet by the crimping process. Three kinds of pyramidal structures are made and used to fabricate test specimen. Through the multi-point electrical resistance welding, inner structures are bonded with skin sheet. 3-point bending tests are carried out to measure the bending stiffness of ISB panel and experimental results are discussed.

A Study on the Improvement of Formability of Embossing Structure (엠보싱 구조재의 성형성 향상에 관한 연구)

  • Kim H.J.;Jung D.W.;Choi D.S.;Jae T.J.;Park J.H.
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2005.06a
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    • pp.1269-1272
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    • 2005
  • Sandwich structures, which are composed of thick core between two thin faces, are commonly used in many engineering applications because they combine high stiffness and strength with low weight. In this research, we have investigated the embossing configuration at the sheet metal shape through research with regard to the construction that the hardness and stiffness are excellent, and formability is advantage as inner structure. Through the FLD analysis according to the pattern changes, we have confirmed the forming possibility and variation of the aspect thickness. Also, we have fabricated the embossing press mold according to the pattern changes, and obtained the embossing inner structure the forming experiments.

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NUMERICAL STUDY ON THE CHARACTERISTICS OF VORTEX FREQUENCY AND LAMINAR MIXING OF A PASSIVE SCALAR IN COAXIAL JET FLOWS (동축제트의 와류주파수 및 혼합특성에 대한 수치해석 연구)

  • Kim, Won-Hyun;Park, Tae-Seon
    • 한국전산유체공학회:학술대회논문집
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    • 2007.10a
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    • pp.21-26
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    • 2007
  • This study focuses on the near-field vortical structure and dynamics of coaxial jets. The characteristics of laminar flow and mixing in coaxial jets are investigated using a unsteady flow simulation. In order to analyze the geometic effects on the vortical structure, several cases of different configurations are selected for various values of the velocity ratio of inner jet to outer jet. From the result, it is confirmed that mixing is promoted by the development of vortical structure and the interaction between inner jet and outer jet. This feature is strongly related to the vortex frequency in the shear-layers. The vortex frequency depends on the velocity ratio and the lip thickness of inner nozzle, but the outer pipe length has no effect on the frequency variation.

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NUMERICAL STUDY ON THE CHARACTERISTICS OF VORTEX FREQUENCY AND LAMINAR MIXING OF A PASSIVE SCALAR IN COAXIAL JET FLOWS (동축제트의 와류주파수 및 혼합특성에 대한 수치해석)

  • Kim, Won-Hyun;Park, Tae-Seon
    • Journal of computational fluids engineering
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    • v.14 no.3
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    • pp.49-55
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    • 2009
  • This study focuses on the near-field vortical structure and dynamics of coaxial jets. The characteristics of laminar flow and mixing in coaxial jets are investigated using a unsteady flow simulation. In order to analyze the geometric effects on the vortical structure, several cases of different configurations are selected for various values of the velocity ratio of inner jet to outer jet. From the result, it is confirmed that the flow mixing is promoted by the development of vortical structure and the interaction between inner jet and outer jet. This feature is strongly related to the vortex frequency in the shear-layers. The vortex frequency depends on the velocity ratio and the lip thickness of inner nozzle, but the outer pipe length has no effect on the frequency variation.