• Title/Summary/Keyword: Mesh processing

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Text Verification Based on Sub-Image Matching (부분 영상 매칭에 기반한 텍스트 검증)

  • Son Hwa Jeong;Jeong Seon Hwa;Kim Soo Hyung
    • The KIPS Transactions:PartB
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    • v.12B no.2 s.98
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    • pp.115-122
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    • 2005
  • The sub-mage matching problem in which one image contains some part of the other image, has been mostly investigated on natural images. In this paper, we propose two sub-image matching techniques: mesh-based method and correlation-based method, that are efficiently used to match text images. Mesh-based method consists of two stages, box alignment and similarity measurement by extracting the mesh feature from the two images. Correlation-based method determines the similarity using the correlation of the two images based on FFT function. We have applied the two methods to the text verification in a postal automation system and observed that the accuracy of correlation-based method is $92.7\%$ while that of mesh-based method is $90.1\%$.

Effect of Strain Rate Sensitivity and Mesh Size on Constitutive Equation Fitting Using Finite Element Analysis (유한요소해석을 사용한 구성 방정식 피팅 시 변형률 속도 민감도 및 요소 크기의 영향)

  • Gu, G.H.;Kim, Y.;Seo, M.H.;Kim, H.S.
    • Transactions of Materials Processing
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    • v.31 no.4
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    • pp.200-206
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    • 2022
  • The finite element analysis is one of the representative methods for predicting the materials behavior for experiments that are difficult to perform empirically. Constitutive equations are essential for reducing computation time and sharing data because they enable finite element analysis simulations through simple formulae. However, it is difficult to derive accurate flow curves for all materials as most constitutive equations are not formulated based on their physical meaning. Also, even if the constitutive equation is a good representation of the flow curve to the experimental results, some fundamental issues remain unresolved, such as the effect of mesh size on the calculation results. In this study, a new constitutive equation was proposed to predict various materials by modifying the combined Swift-Voce model, and the calculation results with various mesh sizes were compared to better simulate the experimental results.

Grain Size and Texture of Silver Minerals from Duk-Eum Ore Deposits (덕음광산(德音鑛山) 은광물(銀鑛物)의 입도(粒度)와 조직(組織))

  • Yang, Dong Yun;Chi, Jeong Mahn
    • Economic and Environmental Geology
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    • v.19 no.spc
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    • pp.227-237
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    • 1986
  • The Duk-Eum mine located in Kongsan-myeon, Naju-gun, Cheolanamdo is producing silver ore mainly, with rare gold association. The grade-up and recovery of the concentrates have been concerned to the main problem. And then, this study aimed at applying the basic data for ore processing. In the first half of the study, the attempts were made to identify the ore minerals, this followed by determination of the mineral texture, paragenesis, grain size, and size distribution by employing the microscopical method and the etching test. The results of the study are as follows: 1. The ore deposit is composed of the hydrothermal fissure linked veins, and filling cavities are mostly tensile fractures or joints, in rhyolitic rocks as a wall rock. 2. The principle ore minerals are native silver, acanthite, canfieldite, pyrargyrite, galena, tetrahedrite, sphalerite, pyrrhotite, chalcopyrite, chalcocite, covellite, zincite, and the gangue minerals are quartz and calcite. 3. The grain size of each ore minerals before grinding are; max. $2\frac{1}{2}$ mesh, medium 48-100 mesh(main size, contained over 80%), min. 3200mesh. And the grain size of each ore minerals after grinding is; max. 42mesh, medium 65-250mesh(main size, contained over 80%), min. 3200mesh. 4. The properties of the mineral texture effected on the ore dressing are follows; a) Inclusion texture; the fine grains of chalcopyrite is included in most acanthite, and rarely, that of galena included in acanthite. b) Exsolution texture; pyrargyrite is exsolved in acanthite. c) Replacement texture; native silver replaced pyrargyrite, and acanthite replaced galena. d) Interlocking paragenetic texture; the interlocking paragenetic minerals are pyrite, chalcopyrite, chalcocite, canfieldite. e) Fissure filling texture; chalcopyrite was filled along the cracks in acanthite. Among of the above texture, it is impossible to liberate the grains of a), and more difficult to liberate those of b) and c), while easy to liberate those of d) and e).

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Embedding Multiple Meshes into a Crossed Cube (다중 메쉬의 교차큐브에 대한 임베딩)

  • Kim, Sook-Yeon
    • Journal of KIISE:Computer Systems and Theory
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    • v.36 no.5
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    • pp.335-343
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    • 2009
  • The crossed cube has received great attention because it has equal or superior properties compared to the hypercube that is widely known as a versatile parallel processing system. It has been known that disjoint two copies of a mesh of size $4{\times}2^m$ or disjoint four copies of a mesh of size $8{\times}2^m$ can be embedded into a crossed cube with dilation 1 and expansion 1 [Dong, Yang, Zhao, and Tang, 2008]. However, it is not known that disjoint multiple copies of a mesh with more than eight rows and columns can be embedded into a crossed cube with dilation 1 and expansion 1. In this paper, we show that disjoint $2^{n-1}$ copies of a mesh of size $2^n{\times}2^m$ can be embedded into a crossed cube with dilation 1 and expansion 1 where $n{\geq}1$ and $m{\geq}3$. Our result is optimal in terms of dilation and expansion that are important measures of graph embedding. In addition, our result is practically usable in allocating multiple jobs of mesh structure on a parallel computer of crossed cube structure.

Embedding a Mesh of Size 2n ×2m Into a Twisted Cube (크기 2n ×2m인 메쉬의 꼬인 큐브에 대한 임베딩)

  • Kim, Sook-Yeon
    • The KIPS Transactions:PartA
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    • v.16A no.4
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    • pp.223-226
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    • 2009
  • The twisted cube has received great attention as an interconnection network of parallel systems because it has several superior properties, especially in diameter, to the hypercube. It was recently known that, for even m, a mesh of size $2{\times}2^m$ can be embedded into a twisted cube with dilation 1 and expansion 1 and a mesh of size $4{\times}2^m$ with dilation 1 and expansion 2 [Lai and Tsai, 2008]. However, as we know, it has been a conjecture that a mesh with more than eight rows and columns can be embedded into a twisted cube with dilation 1. In this paper, we show that a mesh of size $2^n{\times}2^m$ can be embedded into a twisted cube with dilation 1 and expansion $2^{n-1}$ for even m and with dilation 1 and expansion $2^n$ for odd m where $1{\leq}n{\leq}m$.

Embedding Mesh-Like Networks into Petersen-Torus(PT) Networks (메쉬 부류 네트워크를 피터슨-토러스(PT) 네트워크에 임베딩)

  • Seo, Jung-Hyun;Lee, Hyeong-Ok;Jang, Moon-Suk
    • The KIPS Transactions:PartA
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    • v.15A no.4
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    • pp.189-198
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    • 2008
  • In this paper, we prove mesh-like networks can be embedded into Petersen-Torus(PT) networks. Once interconnection network G is embedded in H, the parallel algorithm designed in Gcan be applied to interconnection network H. The torus is embedded into PT with dilation 5, link congestion 5 and expansion 1 using one-to-one embedding. The honeycomb mesh is embedded into PT with dilation 5, link congestion 2 and expansion 5/3 using one-to-one embedding. Additional, We derive average dilation. The embedding algorithm could be available in both wormhole routing system and store-and-forward routing system by embedding the generally known Torus and honeycomb mesh networks into PT at 5 or less of dilation and congestion, and the processor throughput could be minimized at simulation through one-to-one.

A Watermarking Algorithm of 3D Mesh Model Using Spherical Parameterization (구면 파라미터기법을 이용한 3차원 메쉬 모델의 워더마킹 알고리즘)

  • Cui, Ji-Zhe;Kim, Jong-Weon;Choi, Jong-Uk
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.18 no.1
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    • pp.149-159
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    • 2008
  • In this paper, we propose a blind watermarking algorithm of 3d mesh model using spherical parameterization. Spherical parameterization is a useful method which is applicable to 3D data processing. Especially, orthogonal coordinate can not analyse the feature of the vertex coordination of the 3D mesh model, but this is possible to analyse and process. In this paper, the centroid center of the 3D model was set to the origin of the spherical coordinate, the orthogonal coordinate system was transformed to the spherical coordinate system, and then the spherical parameterization was applied. The watermark was embedded via addition/modification of the vertex after the feature analysis of the geometrical information and topological information. This algorithm is robust against to the typical geometrical attacks such as translation, scaling and rotation. It is also robust to the mesh reordering, file format change, mesh simplification, and smoothing. In this case, the this algorithm can extract the watermark information about $90{\sim}98%$ from the attacked model. This means it can be applicable to the game, virtual reality and rapid prototyping fields.

Performance Improvement of Facial Gesture-based User Interface Using MediaPipe Face Mesh (MediaPipe Face Mesh를 이용한 얼굴 제스처 기반의 사용자 인터페이스의 성능 개선)

  • Jinwang Mok;Noyoon Kwak
    • Journal of Internet of Things and Convergence
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    • v.9 no.6
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    • pp.125-134
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    • 2023
  • The purpose of this paper is to propose a method to improve the performance of the previous research is characterized by recognizing facial gestures from the 3D coordinates of seven landmarks selected from the MediaPipe Face Mesh model, generating corresponding user events, and executing corresponding commands. The proposed method applied adaptive moving average processing to the cursor positions in the process to stabilize the cursor by alleviating microtremor, and improved performance by blocking temporary opening/closing discrepancies between both eyes when opening and closing both eyes simultaneously. As a result of the usability evaluation of the proposed facial gesture interface, it was confirmed that the average recognition rate of facial gestures was increased to 98.7% compared to 95.8% in the previous research.

AN EFFICIENT INCOMPRESSIBLE FREE SURFACE FLOW SIMULATION USING GPU (GPU를 이용한 효율적인 비압축성 자유표면유동 해석)

  • Hong, H.E.;Ahn, H.T.;Myung, H.J.
    • Journal of computational fluids engineering
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    • v.17 no.2
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    • pp.35-41
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    • 2012
  • This paper presents incompressible Navier-Stokes solution algorithm for 2D Free-surface flow problems on the Cartesian mesh, which was implemented to run on Graphics Processing Units(GPU). The INS solver utilizes the variable arrangement on the Cartesian mesh, Finite Volume discretization along Constrained Interpolation Profile-Conservative Semi-Lagrangian(CIP-CSL). Solution procedure of incompressible Navier-Stokes equations for free-surface flow takes considerable amount of computation time and memory space even in modern multi-core computing architecture based on Central Processing Units(CPUs). By the recent development of computer architecture technology, Graphics Processing Unit(GPU)'s scientific computing performance outperforms that of CPU's. This paper focus on the utilization of GPU's high performance computing capability, and presents an efficient solution algorithm for free surface flow simulation. The performance of the GPU implementations with double precision accuracy is compared to that of the CPU code using an representative free-surface flow problem, namely. dam-break problem.

A Stydy on the Preparation of Cu-Graphite Composite Powders (흑연-금속동 복합분말제조에 관한 연구)

  • Oh, Jong-Kee;Kim, Taek-Hoon;Lee, Hwa-Yeong
    • Korean Journal of Materials Research
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    • v.3 no.2
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    • pp.103-110
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    • 1993
  • Abstract It has been attempted to make the copper-graphite composites by deposition of copper on the surface of graphite through the hydrogen reduction of copper chlorides. Both KISH and natural graphites of less than 325 mesh were used as substrates and the hydrogen reduction also was conducted in the range of 350-50$0^{\circ}C$. The distribution of copper on the surface of graphite was found to increase with the decrease of reduction temperature. In addition. the partial pressure of hydrogen played an important role in the overall rate of reduction which was substantially dominated by the chemical reaction on the surface of each particle. It was concluded that the reduction temperature should be maintained as low as possible to accomplish the well distribution of copper in the composites.

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