• Structural Engineering and Mechanics
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• v.69 no.5
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• pp.527-536
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• 2019

This paper will compare $T3{\gamma}_s$ and MITC3 elements, both these two elements are three-node triangular plate bending elements with three degrees of freedom per node. The formulation of the $T3{\gamma}_s$ and MITC3 elements is rather simple and has already been widely used. This paper will prove that the shear strain formulation of these two elements is identical even though they are obtained from two different methods. A single element is used to test the formulation of shear strain matrices. Numerical tests for circular plate cases compared with the exact solutions and with DKMT element will complete this review to verify the performances and show the convergence of these two elements.

• Journal of Korea Game Society
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• v.2 no.1
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• pp.62-68
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• 2002

This paper presents a method for tessellating trimmed NURBS surface with preserving sharp shape Although several existing approaches need a large number of triangular meshes to represent sharp shape of surface, resulting triangular meshes may not reflect sharp edges properly. In this study, we flit detect the sharp shape of NURBS surface automatically using C1 continuous condition and then use constraint Delaunay triangulation method to present exact sharp shape with the minimum triangular meshes. And we also use approximated developed surface domain as triangulation domain of rimmed NURBS surface. In this way, the shape of triangular elements on the triangular domains is approximately preserved and can avoid distortion when mapped into three-dimensional space. finally, we show examples that demonstrate the effectiveness of the proposed scheme in terms of reducing the number of triangular meshes and preserving sharp shape of surface more exactly.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.22 no.6
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• pp.1244-1250
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• 1997

An arbitrary shaped iris in rectangular waveguideis investigated using FEM-CDMA with triangularprism elements in this paper. The volume of irisis subdivided into a relatively small number of triangular prism elements and FEM is used to formulate the field distribution. On the other hand, the fields in the waveguide region are represented by BIM derived from the waveguide Green's function and boundary conditions. The proposed method is verified through the design and experiment for the circular iris filter using WR-90 waveguide.

• Structural Engineering and Mechanics
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• v.76 no.3
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• pp.379-393
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• 2020

In this paper, we propose an automatic procedure to improve the accuracy of finite element solutions using enriched 2D solid finite elements (4-node quadrilateral and 3-node triangular elements). The enriched elements can improve solution accuracy without mesh refinement by adding cover functions to the displacement interpolation of the standard elements. The enrichment scheme is more effective when used adaptively for areas with insufficient accuracy rather than the entire model. For given meshes, an error for each node is estimated, and then proper degrees of cover functions are applied to the selected nodes. A new error estimation method and cover function selection scheme are devised for the proposed adaptive enrichment scheme. Herein, we demonstrate the proposed enrichment scheme through several 2D problems.

• Structural Engineering and Mechanics
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• v.68 no.4
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• pp.385-398
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• 2018

In the present paper, we offer a new flat shell finite element. It is the result of the combination of a membrane element and a bending element, both based on the strain-based formulation. It is known that $C^{\circ}$ plane membrane elements provide poor deflection and stress for problems where bending is dominant. In addition, they encounter continuity and compliance problems when they connect to C1 class plate elements. The reach of the present work is to surmount these problems when a membrane element is coupled with a thin plate element in order to construct a shell element. The membrane element used is a triangular element with four nodes, three nodes at the vertices of the triangle and the fourth one at its barycenter. Each node has three degrees of freedom, two translations and one rotation around the normal. The coefficients related to the degrees of freedom at the internal node are subsequently removed from the element stiffness matrix by using the static condensation technique. The interpolation functions of strain, displacements and stresses fields are developed from equilibrium conditions. The plate element used for the construction of the present shell element is a triangular four-node thin plate element based on Kirchhoff plate theory, the strain approach, the four fictitious node, the static condensation and the analytic integration. The shell element result of this combination is robust, competitive and efficient.

• Journal of the Korean Society for Marine Environment & Energy
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• v.16 no.2
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• pp.130-137
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• 2013

The more accurate numerical analysis is needed, The more important to arrange nodes and elements properly on the structures wanted to be analyzed. In this study, automatic mesh generation method is developed for triangular mesh modeling in wind tower and substructure formed in circular sections especially, which have structural and economical benefits in shallow water area. It can consider variety conditions by inputting the detail data such as height and types. Also, this study includes the comparison and verification with the mesh generation by Delaunay triangular technique on 3 dimensional space and the examples of mesh generation for proposed tower and substructure. The result of this study will be widely applied to analyze the existing and proposed models for wind turbines.

• Structural Engineering and Mechanics
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• v.39 no.6
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• pp.767-793
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• 2011

An efficient edge-based smoothed finite element method (ES-FEM) has been recently developed for solving solid mechanics problems. The ES-FEM uses triangular elements that can be generated easily for complicated domains. In this paper, the complexity study of the ES-FEM based on triangular elements is conducted in detail, which confirms the ES-FEM produces higher computational efficiency compared to the FEM. Therefore, the ES-FEM offers an excellent platform for adaptive analysis, and this paper presents an efficient adaptive procedure based on the ES-FEM. A smoothing domain based energy (SDE) error estimate is first devised making use of the features of the ES-FEM. The present error estimate differs from the conventional approaches and evaluates error based on smoothing domains used in the ES-FEM. A local refinement technique based on the Delaunay algorithm is then implemented to achieve high efficiency in the mesh refinement. In this refinement technique, each node is assigned a scaling factor to control the local nodal density, and refinement of the neighborhood of a node is accomplished simply by adjusting its scaling factor. Intensive numerical studies, including an actual engineering problem of an automobile part, show that the proposed adaptive procedure is effective and efficient in producing solutions of desired accuracy.

• Educational Technology International
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• v.21 no.1
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• pp.31-67
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• 2020

The purpose of this study was to propose an education cooperation model for Human Resources Development (HRD) in Asia-Pacific region in response to environmental changes in business and industry. In order to carry out the model, this study reviewed the key features of human resources in the APEC which is a symbolic regional integration entity in Asia-Pacific region, shaped critical issues related with HRD in this region and then analyzed the trends of education cooperation projects conducted by the APEC in terms of topics, implementation methods and proposing economies of the projects. In result, this study proposed a triangular education cooperation model for HRD consisting of three elements: Voluntary Partnership, Information on Needs and Support for Cooperation. These interconnected and interdependent elements were designed to encourage actors to participate in education cooperative activities with their own willingness, produce and manage research-based information required for sustainable cooperation and support communication and connectivity among actors for effective activities. Also, this study expected that this model would make a commitment to narrowing educational divides, enhancing global-standard skills development, facilitating public and private partnership and organizing the foundation of future education for cultivating creative talents in the era of innovation for APEC members.

• Journal of applied mathematics & informatics
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• v.42 no.1
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• pp.1-14
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• 2024

Let G = (V, E) be a (p, q) graph. Define $$\begin{cases}\frac{p}{2},\:if\:p\:is\:even\\\frac{p-1}{2},\:if\:p\:is\:odd\end{cases}$$ and L = {±1, ±2, ±3, ···, ±ρ} called the set of labels. Consider a mapping f : V → L by assigning different labels in L to the different elements of V when p is even and different labels in L to p - 1 elements of V and repeating a label for the remaining one vertex when p is odd.The labeling as defined above is said to be a pair difference cordial labeling if for each edge uv of G there exists a labeling |f(u) - f(v)| such that |Δ_f1 - Δ_f^c1| ≤ 1, where Δ_f1 and Δ_f^c1 respectively denote the number of edges labeled with 1 and number of edges not labeled with 1. A graph G for which there exists a pair difference cordial labeling is called a pair difference cordial graph. In this paper we investigate the pair difference cordial labeling behavior of subdivision of some graphs.

• Korean Journal of Computational Design and Engineering
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• v.10 no.1
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• pp.70-75
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• 2005

A 3D solid element mesh generation algorithm was newly developed. 3D surface points of global rectangular coordinates were supplied by a 3D laser scanner. The algorithm is strait forward and simple but it generates mixed solid elements such as hexagonal, pyramid and prism types. Then, the surface triangular or rectangular elements were generated from the solid elements. The key of the algorithm is elimination of elements and 3D adaptive surface smoothing using given 3D surface point data.