• Title/Summary/Keyword: Triangular method

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Development of an Incompressible Navier-Stokes Solver using SMAC Algorithm on Unstructured Triangular Meshes (비구조형 삼각형 격자에 대한 SMAC기법을 이용한 비압축성 나비어-스톡스 방정식 해법 개발)

  • Nam Hyeun S.;Moon Young J.
    • 한국전산유체공학회:학술대회논문집
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    • 1997.10a
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    • pp.55-60
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    • 1997
  • An unstructured finite volume method is presented for seeking steady and unsteady flow solutions of the two-dimensional incompressible viscous flows. In the present method, SMAC-type algorithm is implemented on unstructured triangular meshes, using second order upwind scheme for the convective fluxes. Validation tests are made for various steady and unsteady incompressible flows. Convergence characteristics are examined and accuracy comparisons are made with some benchmark solutions.

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Synthesis and Analysis of Optical Transfer Function of the Modified Triangular Interferometer by Two - pupil Synthesis Method

  • Kim, Soo-Gil
    • Journal of the Optical Society of Korea
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    • v.8 no.4
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    • pp.182-187
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    • 2004
  • We synthesized and analyzed the optical transfer function(OTF) of the modified triangular interferometer (MTI) using two-pupil synthesis method. Also, we presented the optimal MTI, which can obtain any bipolar function by combining two wave plates and a linear polarizer. By using the proposed MTI, we can obtain the complex hologram without bias and conjugate image.

Electromagnetic Field Uniformity Characteristics of a Triangular Reverberation Chamber with Schroeder Diffusers (Schroeder 확산기를 적용한 삼각형 전자파 잔향실의 필드 균일도 특성)

  • 김성철;이중근
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.13 no.4
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    • pp.373-378
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    • 2002
  • This paper presents the results of an electromagnetic field uniformity of a triangular reverberation chamber that can be used alternatively for analysis and measurement of electromagnetic interference and immunity test. Equilateral triangular reverberation chamber and Schroeder diffusers were designed and fabricated for this purpose. FDTD simulation method was applied to analyze the field distribution inside of two different types of reverberation chambers. As a result, the electromagnetic field uniformity was improved inside of triangular reverberation chambers, and the measured field uniformity was improved by 1 ∼4 ㏈ compared to the ones without diffusers.

A RENDERING ALGORITHM FOR HYBRID SCENE REPRESENTATION

  • Tien, Yen;Chou, Yun-Fung;Shih, Zen-Chung
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 2009.01a
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    • pp.17-22
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    • 2009
  • In this paper, we discuss two fundamental issues of hybrid scene representation: constructing and rendering. A hybrid scene consists of triangular meshes and point-set models. Consider the maturity of modeling techniques of triangular meshes, we suggest that generate a point-set model from a triangular mesh might be an easier and more economical way. We improve stratified sampling by introducing the concept of priority. Our method has the flexibility that one may easily change the importance criteria by substituting priority functions. While many works were devoted to blend rendering results of point and triangle, our work tries to render point-set models and triangular meshes as individuals. We propose a novel way to eliminate depth occlusion artifacts and to texture a point-set model. Finally, we implement our rendering algorithm with the new features of the shader model 4.0 and turns out to be easily integrated with existing rendering techniques for triangular meshes.

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Effective Lateral Canthal Lengthening with Triangular Rotation Flap

  • Kim, Min Soo
    • Archives of Plastic Surgery
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    • v.43 no.4
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    • pp.311-315
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    • 2016
  • In Korea, lateral canthoplasty, along with medial epicanthoplasty, has become popular over the past years to widen the horizontal length of the palpebral fissure. However, the effect of the surgery differs greatly depending on the shape and structure of the eyes. If over-widened, complications such as eversion, scarring, and conjunctival exposure may occur. Thus, the author of this study suggests a more effective and safe method for lateral canthal lengthening that causes minimal complications. A total of 236 patients underwent lateral canthoplasty between July 2007 and December 2015. For each patient, a triangular flap 4-5 mm away from the lateral canthus was elevated and rotated 45 degrees laterally while the continuity of the lower eyelid gray line was maintained. A new lateral canthus was created by fixating the rotation flap to the lateral orbital rim with minimal skin trimming and tension-free sutures, preventing relapse and maintaining a triangular shape. In more than 95% of cases, effective and satisfactory extension was achieved. On average, a 3 mm extension of the lateral canthus was achieved. There were minor complications such as wound dehiscence, webbing, and scarring, which were easily corrected. The author not only extended the lateral canthus 3-4 mm laterally but also maintained the continuity of the gray line on the lower lid as a more natural-looking triangular shape, while minimizing complications such as webbing and conjunctival exposure.

Correction of The Unilateral Cleft Lip Using Triangular Flap Technique - Report of cases - (삼각 피판법을 이용한 편측성 구순열의 교정 -증례보고-)

  • Lee, Ju-Hwan;Lee, In-Woo;Seo, Byoung-Moo
    • Korean Journal of Cleft Lip And Palate
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    • v.12 no.1
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    • pp.41-46
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    • 2009
  • Historically, various techniques to correct the deformity of lip and nose in functional and esthetic ways were developed and applied in dealing the patients with cleft lip. When treating the patients with unilateral cleft lip, many surgeons adopt the rotation-advancement method originally developed by Millard, or the triangular flap technique developed by Tennison, Randall or the modifications of these techniques. Among these, triangular flap technique has its advantage in designing the flap using the patient's anatomic landmarks. It enables less skillful operator to perform this technique relatively easily and produce reasonable results. In this report we present 8 cases of unilateral complete cleft lip and 3 casesof unilateral incomplete cleft lip. They all underwent primary cheiloplasty based on triangular flap technique, and functional, esthetic outcomes were favorable.

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VVC Intra Triangular Partitioning Prediction for Screen Contents (스크린 콘텐츠를 위한 VVC 화면내 삼각형 분할 예측 방법)

  • Choe, Jaeryun;Gwon, Daehyeok;Han, Heeji;Lee, Hahyun;Kang, Jungwon;Choi, Haechul
    • Journal of Broadcast Engineering
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    • v.25 no.3
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    • pp.325-337
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    • 2020
  • Versatile Video Coding (VVC) is a new video coding standard that is being developed by the Joint Video Experts Team of ISO/IEC/ITU-T and it has adopted various technologies including screen content coding tools. Screen contents have a feature that blocks are likely to have diagonal edges like character regions. If triangular partitioning coding is allowed for screen contents having such the feature, coding efficiency would increase. This paper proposes a intra prediction method using triangular partitioning prediction for screen content coding. Similar to the Triangular Prediction Mode of VVC that supports the triangular partitioning prediction, the proposed method derives two prediction blocks using Horizontal and Vertical modes and then it blends the predicted blocks applying masks with triangle shape to generate a final prediction block. The experimental results of the proposed method showed an average of 1.86%, 1.49%, and 1.55% coding efficiency in YUV, respectively, for VVC screen content test sequences.

A Study on the Generation of Initial Shape for the Initiation of Optimal Blank Design Sequence (최적블랭크 설계를 위한 초기형상 생성에 관한 연구)

  • 심현보;장상득;박종규
    • Transactions of Materials Processing
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    • v.13 no.1
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    • pp.90-101
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    • 2004
  • An inverse mosaic method has been proposed to generate an initial blank shape from the final product shape. Differently from the geometric mapping method, the method can handle triangular patches. However, the generated blank shape is strongly dependent on the order of determination of nodes. In order to compensate the dependency error smoothing technique has been also developed. Although the accuracy has been improved greatly compared with the geometrical mapping method, the method has limitation, due to the no incorporation of plasticity theory. Even though the accuracy of the radius vector method is already proved. the method requires initial guess to start the method. In order to compromise the limitation of the present method and the radius vector method, the method has been connected to the radius vector method. The efficiency of the present optimal blank design method has been verified with some chosen examples.

An Efficient Triangular Mesh Generation Algorithm using Domain-wise Hash Structure (영역기반 해쉬구조를 이용한 효율적 삼각형 자동 요소망 생성 알고리듬 개발)

  • Kim, Tae-Joo;Cho, Jin-Yeon
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.32 no.9
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    • pp.41-48
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    • 2004
  • In this work, a domain-wise hash structure is developed for efficient data handling, and by using the developed domain-wise hash structure, an automatic triangular mesh generation algorithm is proposed. To generate the optimal nodal points and triangles efficiently, the advancing layer method and Delaunay triangulation method are utilized. To investigate the performance of the proposed algorithm, benchmarking tests are carried out for various models including convex, concave and complicated shapes through the developed object oriented C++ mesh generation code.

I-V and C-V measurements or fabricated P+/N junction mode in Antimony doped (111) Silicon

  • Jung, Won-Chae
    • Transactions on Electrical and Electronic Materials
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    • v.3 no.2
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    • pp.10-15
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    • 2002
  • In this paper, the electrical characteristics of fabricated p+-n junction diode are demonstrated and interpreted with different theoretical calculations. Dopants distribution by boron ion implantation on silicon wafer were simulated with TRIM-code and ICECaEM simulator. In order to make electrical activation of implanted carriers, thermal annealing treatments are carried out by RTP method for 1min. at $1000^{circ}C$ under inert $N_2$ gas condition. In this case, profiles of dopants distribution before and after heat treatments in the substrate are observed from computer simulations. In the I-V characteristics of fabricated diodes, an analytical description method of a new triangular junction model is demonstrated and the results with calculated triangular junction are compared with measured data and theoretical calculated results of abrupt junction. Forward voltage drop with new triangular junction model is lower than the case of abrupt junction model. In the C-V characteristics of diode, the calculated data are compared with the measured data. Another I-V characteristics of diodes are measured after proton implantation in electrical isolation method instead of conventional etching method. From the measured data, the turn-on characteristics after proton implantation is more improved than before proton implantation. Also the C-V characteristics of diode are compared with the measured data before proton implantation. From the results of measured data, reasonable deviations are showed. But the C-V characteristics of diode after proton implantation are deviated greatly from the calculated data because of leakage currents in defect regions and layer shift of depletion by proton implantation.