• Title/Summary/Keyword: Mesh stability

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Mesh Stability Study for the Performance Assessment of a Deep Geological Repository Using APro

  • Hyun Ho Cho;Hong Jang;Dong Hyuk Lee;Jung-Woo Kim
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.21 no.2
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    • pp.283-294
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    • 2023
  • APro, developed in KAERI for the process-based total system performance assessment (TSPA) of deep geological disposal systems, performs finite element method (FEM)-based multiphysics analysis. In the FEM-based analysis, the mesh element quality influences the numerical solution accuracy, memory requirement, and computation time. Therefore, an appropriate mesh structure should be constructed before the mesh stability analysis to achieve an accurate and efficient process-based TSPA. A generic reference case of DECOVALEX-2023 Task F, which has been proposed for simulating stationary groundwater flow and time-dependent conservative transport of two tracers, was used in this study for mesh stability analysis. The relative differences in tracer concentration varying mesh structures were determined by comparing with the results for the finest mesh structure. For calculation efficiency, the memory requirements and computation time were compared. Based on the mesh stability analysis, an approach based on adaptive mesh refinement was developed to resolve the error in the early stage of the simulation time-period. It was observed that the relative difference in the tracer concentration significantly decreased with high calculation efficiency.

Comparative study on long-term stability in mandibular sagittal split ramus osteotomy: hydroxyapatite/poly-ʟ-lactide mesh versus titanium miniplate

  • Park, Young-Wook;Kang, Hyun-Sik;Lee, Jang-Ha
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.41
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    • pp.8.1-8.6
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    • 2019
  • Background: Resorbable devices have recently been adopted in the field of orthognathic surgery with controversies about their postoperative skeletal stability. Hence, we determined the long-term skeletal stability of unsintered hydroxyapatite/poly-ʟ-lactic acid (HA/PLLA) mesh for osteofixation of mandibular sagittal split ramus osteotomy (SSRO), and compared it with that of titanium miniplate. Methods: Patients were divided into resorbable mesh and titanium miniplate fixation groups. A comparative study of the change in the mandibular position was performed with preoperative, 1-day, 6-month, and 2-year postoperative lateral cephalograms. Results: At postoperative 6 months-compared with postoperative 1 day, point B (supra-mentale) was significantly displaced anteriorly in the titanium-fixation group. Moreover, at postoperative 2 years-compared with postoperative 6 months, point B was significantly displaced inferiorly in the titanium-fixation. However, the HA/PLLA mesh-fixation group did not show any significant change with respect to point B postoperatively. Conclusions: The HA/PLLA mesh-fixation group demonstrated superior long-term skeletal stability with respect to the position of mandible, when compared with the titanium-fixation group.

An Experimental Study on the Flame Stability of Natural Gas/Air Mixture on the Metal Mesh (금속매쉬에서 천연가스/공기 표면연소의 화염안정성에 관한 실험적 연구)

  • You, Hyun-Seok;Lee, Hyun-Chan;Lee, Joong-Sung
    • Proceedings of the KSME Conference
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    • 2001.06d
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    • pp.49-53
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    • 2001
  • A conventional flame type gas combustion major portion of heat is transferred to the body by convection due to small radiant ability of the gas flame. Increasing the radiation component of heat flux in the combustion zone allows to augment the efficiency of gas utilization. Such effect can be reached by using radiative gas burner applied to metal mesh combustion. Basically the gas radiant burner consists of metallic mesh of high heat resisting steels. In terms of this regards, we have made the burner consisted of metal mesh and measured the radiative flame stability of natural gas/air mixture on the metal mesh burner. The pressure loss through the metal mesh is defined by pressure-velocity slope. The more increased the pressure-velocity slope of the metal mesh is, the wider the stable zone of radiave flame on the metal mesh burner is. And the augmentation of mixture flowrate through the metal mesh make narrow the permissible range of equivalence ratio.

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Efficient routing in multicast mesh by using forwarding nodes and weighted cost function

  • Vyas, Kapila;Khuteta, Ajay;Chaturvedi, Amit
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.13 no.12
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    • pp.5928-5947
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    • 2019
  • Multicast Mesh based Mobile Ad-hoc NETworks (MANETs) provide efficient data transmission in energy restraint areas without a fixed infrastructure. In this paper, the authors present an improved version of protocol SLIMMER developed by them earlier, and name it SLIMMER-SN. Most mesh-based protocols suffer from redundancy; however, the proposed protocol controls redundancy through the concept of forwarding nodes. The proposed protocol uses remaining energy of a node to decide its energy efficiency. For measuring stability, a new metric called Stability of Node (SN) has been introduced which depends on transmission range, node density and node velocity. For data transfer, a weighted cost function selects the most energy efficient nodes / most stable nodes or a weighted combination of both. This makes the node selection criteria more dynamic. The protocol works in two steps: (1) calculating SN and (2) using SN value in the weighted cost function for selection of nodes. The study compared the proposed protocol, with other mesh-based protocols PUMA and SLIMMER, based on packet delivery ratio (PDR), throughput, end-to-end delay and average energy consumption under different simulation conditions. Results clearly demonstrate that SLIMMER-SN outperformed both PUMA and SLIMMER.

The Study of Structural Stability by Stacking Method of the Axial Blade (축류 블레이드의 스태킹 방식에 의한 구조 안정성 연구)

  • Jeong, Cheol-Young;Ko, Hee-Hwan;Park, Jun-Young
    • The KSFM Journal of Fluid Machinery
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    • v.15 no.1
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    • pp.46-51
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    • 2012
  • This study is to confirm the deformation of blade when the location of stacking is moving. Also, it desire to determine the most stable location of stacking from the analysis. In the previous study, it is Known that moving the location of stacking is not influence to the aerodynamic performance. In this study SolidWorks premium 2010 SP4 is used for structure analysis. In reference blade and other 3 model analysis, the two mesh type is used, one is standard mesh type in SolidWorks, the other is curvature-based mesh type. The result of curvature-based mesh type is more stable than one of the standard mesh type regardless of mesh size, the number of mesh. The deformation of blade tip is the smallest, when the location of stacking is identical to the center of gravity of the blade section profile. So, if possible is design, this study recommends that the location of stacking is identical to the center of gravity the blade.

Automatic Tetrahedral Mesh Generation using 3-D Operators (3-D 오퍼레이터를 이용한 사면체 요소망의 자동 생성)

  • 권기연;채수원;이병채
    • Korean Journal of Computational Design and Engineering
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    • v.9 no.1
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    • pp.27-34
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    • 2004
  • A tetrahedral mesh generation scheme using 3-D operators has been presented. The proposed scheme employs new 3-D operators such as rearranging and modified finishing operators in addition to the previous trimming, wedging, digging, splitting and finishing operators. These new operators have been introduced in order to increase the stability of mesh generation process. Check processings with surrounded element edges and faces have also been optimized by employing a searching algorithm. Sample meshes are constructed to demonstrate the mesh generating capability of the proposed algorithm.

Characterization of Nickel-coated Silver Nanowire Flexible Transparent Electrodes with a Random-mesh Structure Formed by Bubble Control (거품 제어에 의해 형성된 무정형 그물망 구조의 니켈이 코팅된 은나노와이어 유연 투명전극의 특성 분석)

  • Park, Jong Seol;Park, Tae Gon;Park, Jin Seok
    • Journal of the Semiconductor & Display Technology
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    • v.19 no.3
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    • pp.36-42
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    • 2020
  • Silver nanowire (AgNW) random-meshes with high transmittance, low sheet resistance, and high oxidation stability and flexibility were fabricated using solution-based processes. The random-mesh structure was obtained by forming bubbles whose sizes and densities were controlled using a corona treatment of polyethylene terephthalate (PET) substrates. To reduce the sheet resistance of the fabricated AgNW electrode, a washing process using ethanol solution was performed. In addition, nickel (Ni) was coated on AgNW to improve resistance to oxidation. The effects of corona treatment and Ni-coating on the transmittance, sheet resistance, oxidation stability, and flexibility of the AgNW electrodes were investigated.

An Efficient Mobility Support Scheme based Multi-hop ARP in Wireless Mesh Networks (무선메쉬 네트워크 환경에서 다중홉 ARP 기반의 효율적인 이동성 지원)

  • Jeon, Seung-Heub;Cho, Young-Bok;Lee, Sang-Ho
    • Journal of the Korea Society of Computer and Information
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    • v.14 no.11
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    • pp.91-96
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    • 2009
  • In this paper, interoperability in heterogeneous wireless mesh network, and mesh nodes for providing efficient IP mobility technique offers multi-hop ARP. Heterogeneous wireless mesh networks to MANETs based on a wireless mesh network backbone and non-MANET architecture is based on a client wireless mesh network and the two mobile networks, combined with a hybrid wireless mesh network are separate. In two different hybrid wireless mesh network routing protocols used to connect the two protocols in the protocol conversion at the gateway to parallel processing problems seriously overload occurs. All of the network reliability and stability are factors that reduce. Therefore, for efficient integration with L3 routing protocols, design techniques to build ARP multi-hop go through the experiment to increase the number of mesh nodes, the packet forwarding rate and an increased hop number of the node was to ensure reliability and stability.

Applicability Study of Geotextile Mesh Soil Nail on Slope Reinforcement Using Numerical Analysis (수치해석을 이용한 토목섬유망 네일의 사면보강에 대한 적용성 연구)

  • You, Kwang Ho;Jung, Yeun Hak;Ha, Ji Young
    • Tunnel and Underground Space
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    • v.25 no.3
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    • pp.264-274
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    • 2015
  • In this study, the applicability of geotextile mesh soil nails on slopes was evaluated by numerical analysis to reduce environmental problems which a general soil nailing might produce and to improve its economical efficiency and construction convenience. To this end, in situ pull-out tests were conducted for both general soil nail and geotextile mesh soil nail and their pull-out characteristics were analyzed. Also, finite difference method was used to verify the suitability of numerical simulation. Parameters for nail and ground conditions were selected and sensitivity analysis was performed for the evaluation of slope stability. In addition, analysis was performed by limit equilibrium method which is widely used for slope stability analysis in practice. As a result, if the nail diameter was same, there is no big difference between geotextile mesh soil nails and general soil nails in terms of slope stability. Therefore it can be expected that geotextile mesh soil nails could be effective for slope reinforcement since they could keep a slope as stable as general soil nails and give better economical efficiency and construction convenience than general soil nails.

Investigation on the Automatic Tool Mesh Generatio for Sheet Metal Stamping Analysis (박판성형해석을 위한 자동 툴 격자 생성에 관한 연구)

  • 유동진
    • Transactions of Materials Processing
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    • v.9 no.2
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    • pp.140-151
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    • 2000
  • The finite element mesh approach for tool surface description is applied effectively to analyze sheet metal stamping processes. To improve the mesh quality and the stability of the mesh generation process, a gybrid method based on the grid approach and the Delaunay triangulation is proposed in the present work. In the present study, a general method for the mathematical description of arbitrarily shaped tool surface is proposed by introducing the parametric surface approach. A polynomial function employed to describe the base parametric surface and the boundary curves are defined to describe arbitrary three-dimensional trimmed surfaces. To verify the validity of the proposed method, automatic mesh generation is carried out for some shosen complicated parts including actual automotive panel.

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