• Title/Summary/Keyword: minimal surfaces

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Automatic Metallic Surface Defect Detection using ShuffleDefectNet

  • Anvar, Avlokulov;Cho, Young Im
    • Journal of the Korea Society of Computer and Information
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    • v.25 no.3
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    • pp.19-26
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    • 2020
  • Steel production requires high-quality surfaces with minimal defects. Therefore, the detection algorithms for the surface defects of steel strip should have good generalization performance. To meet the growing demand for high-quality products, the use of intelligent visual inspection systems is becoming essential in production lines. In this paper, we proposed a ShuffleDefectNet defect detection system based on deep learning. The proposed defect detection system exceeds state-of-the-art performance for defect detection on the Northeastern University (NEU) dataset obtaining a mean average accuracy of 99.75%. We train the best performing detection with different amounts of training data and observe the performance of detection. We notice that accuracy and speed improve significantly when use the overall architecture of ShuffleDefectNet.

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

  • Ha, Seung-Yeon;Park, Jae-Ok
    • Journal of the Korean Society of Clothing and Textiles
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    • v.33 no.8
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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.

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

  • Jo Sam K.
    • Journal of the Korean Vacuum Society
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    • v.15 no.1
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    • pp.73-80
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    • 2006
  • Thermally-driven effusion of inert gases out from Si(100), into which energetic $\~l keV\;He^+,\;Ne^+,\;A^r+,\;and\;Kr^+ ions$ had been implanted at a moderate substrate temperatures of $\~400 K$, was investigated by means of temperature-programmed desorption (TPD) mass spectrometry. While He effused out broadly over $500\~1,100 K$, Ne, Ar, and Kr effusion occurred sharply at 810, 860, and 875 K, respectively. Hydrogen adsorption/desorption analysis for the ion-treated Si(100) surfaces indicated minimal to severe damage by ions with increasing mass from He to Kr. Implications of these results in light of literature reports are discussed.

Effects of Temperature and Pressure on Quartz Dissolution

  • Choi, Jung-Hae;Chae, Byung-Gon;Kim, Hye-Jin
    • The Journal of Engineering Geology
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    • v.25 no.1
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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.

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

  • Kim, Kyung Min;Lee, Sang Ho;Oh, Sang Hoon
    • Journal of the Earthquake Engineering Society of Korea
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    • v.17 no.3
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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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    • v.17 no.4
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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.

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

  • 이재영
    • Computational Structural Engineering
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    • v.9 no.3
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    • pp.145-155
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    • 1996
  • This paper suggests a new algorithm of automatic mesh generation over planar domains with arbitrarily shaped boundaries and control curves. The algorithm is based on the method of recursively subdividing the domain by the path connecting, with minimum penalty value, two points on the super-loop, which consists of the boundaries and the control curves, The algorithm is not subject to any limitation on the shape of the domain, and its process can be fully automated. Therefore, this algorithm can be implemented into computer programs which require minimal user intervention while generating finite element meshes over complicated domains. This algorithm can also be easily extended for application to the generation of meshes over curved surfaces, or to the adaptive mesh generation.

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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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    • v.34 no.5
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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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    • v.26 no.4
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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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    • v.19 no.1
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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.