• Title/Summary/Keyword: 3-D Surface Effects

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Free surface effects on 2-D airfoils and 3-D wings moving over water

  • Bal, Sakir
    • Ocean Systems Engineering
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    • v.6 no.3
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    • pp.245-264
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    • 2016
  • The iterative boundary element method (IBEM) developed originally before for cavitating two-dimensional (2-D) and three-dimensional (3-D) hydrofoils moving under free surface is modified and applied to the case of 2-D (two-dimensional) airfoils and 3-D (three-dimensional) wings over water. The calculation of the steady-state flow characteristics of an inviscid, incompressible fluid past 2-D airfoils and 3-D wings above free water surface is of practical importance for air-assisted marine vehicles such as some racing boats including catamarans with hydrofoils and WIG (Wing-In-Ground) effect crafts. In the present paper, the effects of free surface both on 2-D airfoils and 3-D wings moving steadily over free water surface are investigated in detail. The iterative numerical method (IBEM) based on the Green's theorem allows separating the airfoil or wing problems and the free surface problem. Both the 2-D airfoil surface (or 3-D wing surface) and the free surface are modeled with constant strength dipole and constant strength source panels. While the kinematic boundary condition is applied on the airfoil surface or on the wing surface, the linearized kinematic-dynamic combined condition is applied on the free surface. The source strengths on the free surface are expressed in terms of perturbation potential by applying the linearized free surface conditions. No radiation condition is enforced for downstream boundary in 2-D airfoil and 3-D wing cases and transverse boundaries in only 3-D wing case. The method is first applied to 2-D NACA0004 airfoil with angle of attack of four degrees to validate the method. The effects of height of 2-D airfoil from free surface and Froude number on lift and drag coefficients are investigated. The method is also applied to NACA0015 airfoil for another validation with experiments in case of ground effect. The lift coefficient with different clearance values are compared with those of experiments. The numerical method is then applied to NACA0012 airfoil with the angle of attack of five degrees and the effects of Froude number and clearance on the lift and drag coefficients are discussed. The method is lastly applied to a rectangular 3-D wing and the effects of Froude number on wing performance have been investigated. The numerical results for wing moving under free surface have also been compared with those of the same wing moving above free surface. It has been found that the free surface can affect the wing performance significantly.

Functional Regulation of Dopamine D3 Receptor through Interaction with PICK1

  • Zheng, Mei;Zhang, Xiaohan;Min, Chengchun;Choi, Bo-Gil;Oh, In-Joon;Kim, Kyeong-Man
    • Biomolecules & Therapeutics
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    • v.24 no.5
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    • pp.475-481
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    • 2016
  • PICK1, a PDZ domain-containing protein, is known to increase the reuptake activities of dopamine transporters by increasing their expressions on the cell surface. Here, we report a direct and functional interaction between PICK1 and dopamine $D_3$ receptors ($D_3R$), which act as autoreceptors to negatively regulate dopaminergic neurons. PICK1 colocalized with both dopamine $D_2$ receptor ($D_2R$) and $D_3R$ in clusters but exerted different functional influences on them. The cell surface expression, agonist affinity, endocytosis, and signaling of $D_2R$ were unaffected by the coexpression of PICK1. On the other hand, the surface expression and tolerance of $D_3R$ were inhibited by the coexpression of PICK1. These findings show that PICK1 exerts multiple effects on $D_3R$ functions.

Error analysis of 3-D surface parameters from space encoding range imaging (공간 부호화 레인지 센서를 이용한 3차원 표면 파라미터의 에러분석에 관한 연구)

  • 정흥상;권인소;조태훈
    • 제어로봇시스템학회:학술대회논문집
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    • 1997.10a
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    • pp.375-378
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    • 1997
  • This research deals with a problem of reconstructing 3D surface structures from their 2D projections, which is an important research topic in computer vision. In order to provide robust reconstruction algorithm, that is reliable even in the presence of uncertainty in the range images, we first present a detailed model and analysis of several error sources and their effects on measuring three-dimensional surface properties using the space encoded range imaging technique. Our approach has two key elements. The first is the error modeling for the space encoding range sensor and its propagation to the 3D surface reconstruction problem. The second key element in our approach is the algorithm for removing outliers in the range image. Such analyses, to our knowledge, have never attempted before. Experimental results show that our approach is significantly reliable.

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Fabrication of Plasma Electrolytic Oxidation Coatings on Magnesium AZ91D Casting Alloys

  • Lee, Sung-Hyung;Yashiro, Hitoshi;Kure-Chu, Song-Zhu
    • Journal of the Korean institute of surface engineering
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    • v.50 no.6
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    • pp.432-438
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    • 2017
  • AZ91D casting alloy requires an advanced plasma anodizing processing because large amount of defects are liable to generate during anodization. In this study, plasma electrolytic oxidation (PEO) of AZ91D Mg alloy was conducted by the application of either constant voltage or current using a pulse mode and its effects on pore formation, surface roughness and corrosion resistance were investigated. The PEO films showed a three-layer structure. The PEO film thickness was found to increase linearly with voltage. The surface roughness, Ra, ranged between $0.2{\mu}m$ and $0.3{\mu}m$. The corrosion resistance increased from RN 3.5 to 9.5 by the PEO treatment when evaluated according to the 72 hour salt spray test. The PEO-treated surface exhibited higher pitting potential than the raw material.

A Study on the 3-D Surface Effects of Fashion Design (패션디자인의 입체적(立體的) 표면효과(表面效果)에 관(關)한 연구(硏究))

  • Kim, Ji-Young;Cho, Kyu-Hwa
    • Journal of Fashion Business
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    • v.9 no.1
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    • pp.1-20
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    • 2005
  • This study is purposed to provide new idea for developing high value added fashion goods by studying relief effects of fashion design. Based on prior researches, various ways to give relief effects were searched and then modern fashion design cases were looked for which were referred to fashion-related magazines and collection-related internet sites since the late 1990s. The ways for relief effects are weaving, industrial finishing, sewing technique. Weaving techniques are about fancy yarns, variation of weaving structure, pile weave. Industrial finishing techniques which can make relief effects are embossing, heat-setting, shearing, pliss, burn out, flocking. Sewing techniques are quilting, pleats, embroidery, slash, attachment in accordance with the way to produce relief effects. The forms of relief effects are tactile pattern that cannot be seen in the distance, subtle relief pattern which is more three-dimensional than tactile pattern, rhythmical relief pattern, sculptural pattern, and deep-volumed pattern. The present research can provide practical data for design by studying techniques of relief effects and collecting and arranging design cases that have been sporadically carried out. The study on relief and unique surface effects can be a way to effectively stimulate and express emotions of modern people with various taste and individuality.

Direct numerical simulations of the turbulent boundary layers over the rough walls (표면조도가 있는 난류경계층의 직접수치모사)

  • Lee, Jae-Hwa;Sung, Hyung-Jin
    • 한국전산유체공학회:학술대회논문집
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    • 2011.05a
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    • pp.379-381
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    • 2011
  • Direct numerical simulations (DNSs) of spatially developing turbulent boundary layers (TBLs) over two-dimensional (2-D) and rod and three-dimensional (3-D) cube rough walls were performed to investigate the effects of streamwise spacing on the properties of the TBL The 2-D and 3-D roughness were periodically arranged in the downstream direction with pitches of px/k=2, 3, 4, 6, 8 and 10 and for the cube, the spanwise spacing is fixed to pz/k=2 with staggered array, where px and pz are the streamwise and spanwise spacings of the roughness and k is the roughness height. Inspection of the Reynolds stresses showed that except for px/k=2 and 3 over the 2-D rough walls, the effects of the surface roughness extend to the outer layer over the 2-D and 3-D rough walls and the magnitude of the Reynolds shear stress in the outer layer is increased with proportion to px/k. However, such results are contrary to the trends of form drag, roughness junction and roughness length against px/k, which showed the maximum values at px/k=8 and 4 over the 2-D and 3-D rough walls respectively.

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Analysis of Dynamic Interaction between Rigid Surface Foundations by 3-D Homogeneous Strip Hyperelement (3차원 Homogeneous Strip Hyperelement를 이용한 표면 강체 기초간 상호 작용 해석)

  • 김재관
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 1997.10a
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    • pp.109-116
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    • 1997
  • The contiguous or adjacent foundations are always coupled through the soil. Hence their behavior is quite different due to the interaction effects between or among the foundations. The interaction effects can be very pronounced if the distance between them is very close. An 3-D homogeneous strip hyperelement is developed to analyze the dynamic interaction between rectangular or irregular shape found ations. The effects of interaction on the dynamic behaviors of the adjacent rigid rectangular foundations. The effects of interaction on the dynamic behaviors of the adjacent rigid rectangular foundations. The effects of interaction on the dynamic behaviors of the adjacent rigid rectangular foundations resting on the surface of a stratum are stratum are studied using the newly developed method.

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Anticancer Effects of Vitamin D3 Analog on Human Leukemic Cell Line(U937) and Role of Vitamin $D_3$ Analog on Immune Function of Human Peripheral Blood Lymphocytes (Human 백혈병 세포에 대한 비타민 $D_3$ 유도체의 항암효과 및 Human 임파구의 면역기능에 대한 비타민 $D_3$ 유도체의 역할)

  • 정수자
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.27 no.1
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    • pp.141-148
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    • 1998
  • This study describes the effects of 1,25-dihydroxyvitamin D3[1,25(OH)2D3, calcitriol] analog, 1,25(OH)2-16ene-23yne-D3 on proliferatin and differentiatin of the human histiocytic lymphoma cell line U937. This paper also describes the effects of 1,25(OH)2-16ene-23yne-D3 on ${\gamma}$-interferon(IFN-${\gamma}$) synthesis by phytohemagglutinin-activated peripheral blood lymphocytes(PBLs). In the present investigation, 1,25(OH2)-16ene-23yne-D3 was compared to the natural metablite of vitamin D3, 1,25(OH)2D3. 1,25(OH)2-16ene-23yne-D3 was more potent than 1,25(OH)2D3 for inhibition of proliferation and induction of differentiation of U937 cells, Its effects on inhibition of proliferation was about 30-fold more potent than 1,25(OH)2D3. On induction of differentiation as measured by nonspecific esterase (NSE) activity and morphologic change, this analog morphologically and functionally differentiated U937 cells to monocyte-macrophage phenotype showing a decrease of N/C ration in Giemsa staining and the increase of adherence ability of surface. After 3 days in culture, a more significant supression of IFN-${\gamma}$ synthesis analog on supression of IFN-${\gamma}$ synthesis was a dose-dependent manner, with peak activity at 10-7M. The strong direct effects of 1,25(OH)2-16ene-23yne-D3 on cell proliferation and cell differentiation, make this compound an interesting candidate for clinical studies for several types of malignancies, and the effects on supression of IFN-${\gamma}$ synthesis provide the further evidence for a role of 1,25(OH)2-16ene-23yne-D3 in immunoregulation.

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Unsteady Aerodynimic Analysis of an Aircraft Using a Frequency Domain 3-D Panel Method (주파수영역 3차원 패널법을 이용한 항공기의 비정상 공력해석)

  • 김창희;조진수;염찬홍
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.18 no.7
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    • pp.1808-1817
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    • 1994
  • Unsteady aerodynamic analysis of an aircraft is done using a frequency domian 3-D panel method. The method is based on an unsteady linear compressible lifting surface theory. The lifting surface is placed in a flight patch, and angle of attack and camber effects are implemented in upwash. Fuselage effects are not considered. The unsteady solutions of the code are validated by comparing with the solutions of a hybrid doublet lattice-doublet point method and a doublet point method for various wing configurations at subsonic and supersonic flow conditions. The calculated results of dynamic stability derivatives for aircraft are shown without comparision due to lack of available measured data or calculated results.