• 제목/요약/키워드: Minimal Surfaces

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친환경패션에 나타난 디자인적 요소의 특성 -선행연구의 내용분석을 중심으로- (Characteristics of Design Elements in Environment-Friendly Fashion -Focus on the Content Analysis of Previous Literature-)

  • 하승연;박재옥
    • 한국의류학회지
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    • 제33권8호
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    • pp.1280-1292
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    • 2009
  • In the current fashion design, the 'environmental friendliness' affects the practically and conceptuality in all industry and culture sectors. This study seeks to examine specific design elements as the content of design factors in environment oriented fashion. The subjects of this paper are studied through scholarly journals that are confined to those from 1990 (when naturalism and ecology trends started to be in fashion) to February 2009. This study used 'Naturalism', 'Green', 'Environment-friendly', 'Eco', 'Sustainable', 'Well-being' and 'Lohas' as key words for the literature search. The analysis is performed through a content analysis and the unit of analysis is based upon the adjectives, nouns, and phrases related to the content of the design elements such as line, color, and textiles. In the results, more expression is natural, minimal, transformable, and sportive style in line, YR, white, soft, pale, and dull tone in color. The prominent textiles and texture were natural fabrics, environment-friendly fabrics, recycled fabrics, natural dyeing, functional finishes, rustic surfaces, flexibility, and extensibility. The results of this paper will help in future fashion design product development for environment-friendly fashion brands.

Si(100)에 주입된 불활성 기체 이온들의 방출 특성 (Thermal Effusion of Implanted Inert Gas Ions from Si(100))

  • 조삼근
    • 한국진공학회지
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    • 제15권1호
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    • pp.73-80
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    • 2006
  • Si(100)에 주입된 불활성 기체 이온들의 열적 방출 특성을 열탈착(temperature-programmed desorption; TPD) 질량분석법으로 고찰하였다. 약 400K의 표면 온도 조건에서 1keV 비온빔에 시료를 노출시켜 주었을 때, He은 $500\~1100 K$의 넓은 온도 범위에서 Si(100)결정 밖으로 분출되어 나온 반면, Ne, Ar, 및 Kr은 각각 810, 860, 875 K 근처에서 매우 좁은 온도 범위에서 TPD 피크를 나타내며 급격하게 방출되었다. He+ 이온으로 처리된 Si(100)은 표면 원자 구조의 손상이 상대적으로 최소한으로 일어났지만, $Ne^+,\;Ar^+,\;Kr^+$ 등의 이온들로 처리된 경우는 질량이 클수록 표면이 원자 스케일로 더 심하게 손상되었음이 수소 흡탈착 분석 결과로 밝혀졌다. 이온빔에 의한 결정 내부의 결함 생성과 관련하여 이러한 실험적 결과가 시사하는 점들을 논의하였다

Effects of Temperature and Pressure on Quartz Dissolution

  • Choi, Jung-Hae;Chae, Byung-Gon;Kim, Hye-Jin
    • 지질공학
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    • 제25권1호
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    • pp.1-8
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    • 2015
  • Deep geological disposal is the preferred storage method for high-level radioactive waste, because it ensures stable long-term storage with minimal potential for human disruption. Because of the risk of groundwater contamination, a buffer of steel and bentonite layers has been proposed to prevent the leaching of radionuclides into groundwater. Quartz is one of the most common minerals in earth's crust. To understand how deformation and dissolution phenomena affect waste disposal, here we study quartz samples at pressure, temperature, and pH conditions typical of deep geological disposal sites. We perform a dissolution experiment for single quartz crystals under different pressure and temperature conditions. Solution samples are collected and the dissolution rate is calculated by analyzing Si concentrations in a solution excited by inductively coupled plasma-atomic emission spectroscopy (ICP-AES). After completing the dissolution experiment, deformation of the quartz sample surfaces is investigated with a confocal laser scanning microscope (CLSM). An empirical formula is introduced that describes the relationship between dissolution rate, pressure, and temperature. These results suggest that bentonite layers in engineering barrier systems may be vulnerable to thermal deformation, even when exposed to higher temperatures on relatively short timescales.

비내진상세를 가지는 기존 저층 철근콘크리트 골조의 내진거동평가 (Seismic Performance Evaluation of Existing Low-rise RC Frames with Non-seismic Detail)

  • 김경민;이상호;오상훈
    • 한국지진공학회논문집
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    • 제17권3호
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    • pp.97-105
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    • 2013
  • In this paper, the a static experiment of on two reinforced concrete (RC) frame sub-assemblages was conducted to evaluate the seismic behaviors of existing RC frames that were not designed to support a seismic load. The specimens were a one span and actual-sized. One of them had two columns with the same stiffness, but the other had two columns with different stiffness values. As Regarding the test results, lots of many cracks occurred on the surfaces of the columns and beam-column joints for the two specimens, but the cover concrete splitting hardly occurred was minimal until the test ends. In the case of the specimen with the same stiffness offor the two columns, the flexural collapse of the left-side column occurred. However, in the case of the specimen with different stiffness values for of the two columns, the beam-column joint finally collapsed, even though the shear strength of the joint was designed to be strong enough to support the lateral collapse load. The nonlinear Nonlinear static analysis of the two specimens was also conducted using the uniaxial spring model, and the analytical results successfully simulated the nonlinear behaviour of the specimens in accordance with the test results.

Self-adaptive sampling for sequential surrogate modeling of time-consuming finite element analysis

  • Jin, Seung-Seop;Jung, Hyung-Jo
    • Smart Structures and Systems
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    • 제17권4호
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    • pp.611-629
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    • 2016
  • This study presents a new approach of surrogate modeling for time-consuming finite element analysis. A surrogate model is widely used to reduce the computational cost under an iterative computational analysis. Although a variety of the methods have been widely investigated, there are still difficulties in surrogate modeling from a practical point of view: (1) How to derive optimal design of experiments (i.e., the number of training samples and their locations); and (2) diagnostics of the surrogate model. To overcome these difficulties, we propose a sequential surrogate modeling based on Gaussian process model (GPM) with self-adaptive sampling. The proposed approach not only enables further sampling to make GPM more accurate, but also evaluates the model adequacy within a sequential framework. The applicability of the proposed approach is first demonstrated by using mathematical test functions. Then, it is applied as a substitute of the iterative finite element analysis to Monte Carlo simulation for a response uncertainty analysis under correlated input uncertainties. In all numerical studies, it is successful to build GPM automatically with the minimal user intervention. The proposed approach can be customized for the various response surfaces and help a less experienced user save his/her efforts.

순환적 분할에 의한 유한 요소망 자동 생성 알고리즘 (An Algorithm of Automatic Mesh Generation by Recursive Subdivisions)

  • 이재영
    • 전산구조공학
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    • 제9권3호
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    • pp.145-155
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    • 1996
  • 이 논문은 평면 상의 영역 경계와 조절선(control curve)에 맞추어서 요소망을 자동 생성하는 알고리즘을 제시하는데 목적이 있다. 여기서 제안하는 알고리즘은 요소망 생성 영역의 경계와 조절선들을 하나의 수퍼 루프(super loop)로 연결하고, 루프(loop)위에 있는 두 절점을 연결하는 최소벌점(minimum penalty)의 경로를 따라서 순환적으로 분할하여 요소를 생성하는 기법에 바탕을 두고 있다. 이 방법은 요소망 생성영역의 형상에 제한이 없으며, 모든 과정을 쉽게 자동화 할 수 있기 때문에 복잡한 영역의 요소망을 최소한의 사용자 개입을 통해서 간편하게 처리할 수 있는 프로그램으로 쉽게 이행할 수 있다. 이 알고리즘은 곡면 요소망 생성이나, 적응적 요소망 생성등에 쉽게 확장하여 적용할 수 있다.

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Synthesis of Composite Particles with Fe3O4 core and Ag Shell for the Development of Fingerprints

  • Zhang, Ling-Yan;Chu, Ting
    • Bulletin of the Korean Chemical Society
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    • 제34권5호
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    • pp.1457-1461
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    • 2013
  • The $Fe_3O_4$-core and Ag-shell ($Fe_3O_4@Ag$ nanoeggs) were prepared through the encapsulation of 3-aminopropyltriethoxysilane-coated magnetite nanoparticle in nano-Ag shell by a simple chemically controlled procedure. The $Fe_3O_4@Ag$ nanoeggs were characterized by scanning electron microscopy, transmission electron microscopy, UV-vis spectrum and superconducting quantum interference device magnetometer, respectively. A detailed analysis is provided of how the hydrolysis and condensation of 3-aminopropyltriethoxysilane and the pH value are vital in fabricating the $Fe_3O_4@Ag$ nanoeggs. The prepared $Fe_3O_4@Ag$ nanoeggs possessed uniform size, improved monodispersity, stability against aggregation and high magnetization, which were utilized for the detection of latent fingerprints deposited onto different surfaces. The experimental results showed that the latent fingerprints developed with the $Fe_3O_4@Ag$ nanoeggs powders exhibited excellent ridge details with minimal background staining.

A study of Physically Implanted Surface Islands by direct Nd:YAG Laser Beam Irradiation

  • Oh, Chang-Heon;Cheon, Suyoung;Lim, Changjin;Lee, Jeongjun;Jeon, Jihyun;Kim, Kyoung-Kook;Chung, Chan-Moon;Cho, Soohaeng
    • Applied Science and Convergence Technology
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    • 제26권4호
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    • pp.66-69
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    • 2017
  • Physically implanted surface islands of Nano Carbon Tube (NCT) and ${\alpha}-F_2O_3$ particles have been produced on Al-doped ZnO (AZO)/glass surfaces by simple and direct ND:YAG laser beam irradiation. Sheet resistance of the reconstructed surface increased by about 3.6% of over AZO. Minimal surface damage can be repaired by ND:YAG laser beam irradiation in conjunction with proper impurities. Implanted islands of NCT, which are considered to be a good conductive impurity, on AZO increased the sheet resistance by about 1.8%, while implanted islands of ${\alpha}-F_2O_3$, an insulating impurity, on AZO increased sheet resistance by about 129% compared with a laser beam treated AZO. This study provides insight regarding surface implantations of nanowires and micro-circuits, doping effects for semiconductors and optical devices, surface area and impurity effects for catalysis.

An IE-FFT Algorithm to Analyze PEC Objects for MFIE Formulation

  • Seo, Seung Mo
    • Journal of electromagnetic engineering and science
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    • 제19권1호
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    • pp.6-12
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    • 2019
  • An IE-FFT algorithm is implemented and applied to the electromagnetic (EM) solution of perfect electric conducting (PEC) scattering problems. The solution of the method of moments (MoM), based on the magnetic field integral equation (MFIE), is obtained for PEC objects with closed surfaces. The IE-FFT algorithm uses a uniform Cartesian grid to apply a global fast Fourier transform (FFT), which leads to significantly reduce memory requirement and speed up CPU with an iterative solver. The IE-FFT algorithm utilizes two discretizations, one for the unknown induced surface current on the planar triangular patches of 3D arbitrary geometries and the other on a uniform Cartesian grid for interpolating the free-space Green's function. The uniform interpolation of the Green's functions allows for a global FFT for far-field interaction terms, and the near-field interaction terms should be adequately corrected. A 3D block-Toeplitz structure for the Lagrangian interpolation of the Green's function is proposed. The MFIE formulation with the IE-FFT algorithm, without the help of a preconditioner, is converged in certain iterations with a generalized minimal residual (GMRES) method. The complexity of the IE-FFT is found to be approximately $O(N^{1.5})$and $O(N^{1.5}logN)$ for memory requirements and CPU time, respectively.

Improvement of the osteogenic potential of ErhBMP-2-/EGCG-coated biphasic calcium phosphate bone substitute: in vitro and in vivo activity

  • Hwang, Jae-ho;Oh, Seunghan;Kim, Sungtae
    • Journal of Periodontal and Implant Science
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    • 제49권2호
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    • pp.114-126
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    • 2019
  • Purpose: The aim of this study was to evaluate the enhancement of osteogenic potential of biphasic calcium phosphate (BCP) bone substitute coated with Escherichia coli-derived recombinant human bone morphogenetic protein-2 (ErhBMP-2) and epigallocatechin-3-gallate (EGCG). Methods: The cell viability, differentiation, and mineralization of osteoblasts was tested with ErhBMP-2-/EGCG solution. Coated BCP surfaces were also investigated. Standardized, 6-mm diameter defects were created bilaterally on the maxillary sinus of 10 male New Zealand white rabbits. After removal of the bony windows and elevation of sinus membranes, ErhBMP-2-/EGCG-coated BCP was applied on one defect in the test group. BCP was applied on the other defect to form the control group. The animals were sacrificed at 4 or 8 weeks after surgery. Histologic and histometric analyses of the augmented graft and surrounding tissue were performed. Results: The 4-week and 8-week test groups showed more new bone (%) than the corresponding control groups (P<0.05). The 8-week test group showed more new bone (%) than the 4-week test group (P<0.05). Conclusions: ErhBMP-2-/EGCG-coated BCP was effective as a bone graft material, showing enhanced osteogenic potential and minimal side effects in a rabbit sinus augmentation model.