• 한국CDE학회논문집
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• 제14권1호
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• pp.33-41
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• 2009

Triangular mesh models are widely used in reverse engineering, computer graphics, rapid prototyping and NC(numerical controller) tool-path generation. Triangular mesh models are generated from point clouds, surface models and solid models. A halfedge-based triangular mesh data structure is proposed and the development considerations are presented. In the presented data structure, halfedge is the key data structure. Halfedge stores its triangle index and the order in the triangle. Triangles do not store the halfedge lists explicitly. Halfedge is referred by value and defined when it is required. Proposed data structure supports four design requirements: efficient rendering, compact memory, supporting efficient algorithms and easy programming.

• 한국정밀공학회지
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• 제16권3호통권96호
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• pp.53-61
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• 1999

STL has several errors such as orientation error, hole error, and acute triangle error on being translated from CAD software. These errors should be corrected before using in Rapid Prototyping. So the software is necessary to correct errors. In this study, STL Editor which is a system for STL error correction and shape modification is developed and contains following characteristics. 1.Apply the triangle based data st겨cture. 2.Use the graphic user interface for easy work. 3.Use the Diet method to reduce data size. 4.Use the Delaunay triangulation method to enhance the quality of STL. 5.Modify the STL errors manually.

• 한국통신학회논문지
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• 제26권10B호
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• pp.1399-1408
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• 2001

본 논문에서는 삼각형 메쉬(triangular mesh)로 이루어진 3차원 모델의 연결 정보(connectivity data)와 형상 정보(geometry data)를 삼각형 팬(triangle fan) 구조에 기반하여 효율적으로 압축하는 부호화 기법을 제안한다. 첫째로, 연결 정보의 무손실 부호화로 꼭지점 차수 왜곡(vertex degree warping) 기법을 제안한다. 기존의 알고리듬이 연결 정보와 형상 정보를 분리하여 부호화하는데 반해 제안하는 알고리듬은 연결 정보를 부호화하는데 형상 정보를 이용하여 압축 효율을 높인다. 둘째로, 형상 정보를 압축하기 위해 이중 평행사변형 예측(dual parallelogram prediction) 기법을 제안한다. 삼각형 팬 구조를 이용함으로써 기존의 삼각형 스트립(triangle strip) 기반의 알고리듬보다 정확한 형상 예측이 가능하고, 예측 오차가 작아지게 된다. 다양한 3차원 메쉬 모델에 대한 모의 실험을 통하여 제안하는 알고리듬이 기존의 알고리듬보다 우수한 압축 성능을 나타냄을 확인하다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1997년도 추계학술대회 논문집
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• pp.647-650
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• 1997

A complete dome structure is based on a basic dome modeling, and the basic dome modeling affects safety of the dome structure. In other to save the manufacture expenses, an optimum shape modeling of a dome structure is necessary work of before manufacture of the dome. In this study, modeling of the triangle optimum shape in the surface of an aluminum dome is more focused to optimize shape of the dome and save manufacture expenses. After being made the systematic procedure of the basic modeling, the programming work of the procedure is performed. The program is made by C language, and the trust of the program is proved by comparison between output data of the program and basic modeling in PATRAN.

• 한국정보시스템학회지:정보시스템연구
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• 제31권2호
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• pp.19-43
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• 2022

Purpose Due to the COVID-19 pandemic, many companies are building virtual workplaces based on virtual reality technology. Through this study, we intend to identify the trend of convergence and convergence research between virtual reality technology and work space, and suggest future promising fields based on this. Design/methodology/approach For this purpose, 12,250 bibliographic data of research papers related to Virtual Reality (VR) and Workplace were collected from Scopus from 1982 to 2021. The bibliographic data of the collected papers were analyzed using Text Mining and Pathfinder Network, Parallel Neighbor Clustering, Nearest Neighbor Centrality, and Triangle Betweenness Centrality. Through this, the relationship between keywords by period was identified, and network analysis and visualization work were performed for virtual reality-based workplace research. Findings Through this study, it is expected that the main keyword knowledge structure flow of virtual reality-based workplace convergence research can be identified, and the relationship between keywords can be identified to provide a major measure for designing directions in subsequent studies.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 2000년도 추계학술대회 학술발표 논문집
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• pp.467-470
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• 2000

Vector quantization (VQ) is widely used in many high-quality and high-rate data compression applications such as speech coding, audio coding, image coding and video coding. When the size of a VQ codebook is large, the computational complexity for the full codeword search method is a significant problem for many applications. A number of complexity reduction algorithms have been proposed and investigated using such properties of the codebook as the triangle inequality. This paper proposes a new structured VQ search algorithm that is based on a multi-stage structure for searching for the best codeword. Even using only two stages, a significant complexity reduction can be obtained without any loss of quality.

• 한국멀티미디어학회논문지
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• 제22권8호
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• pp.913-922
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• 2019

The Internet of Things (IoT) envisions smart objects collecting and sharing data at a massive scale via the Internet. One challenging issue is how to disseminate data to relevant data consuming objects efficiently. In such a massive IoT network, Mission critical data dissemination imposes constraints on the message transfer delay between objects. Due to the low power and communication range of IoT objects, data is relayed over multi-hops before arriving at the destination. In this paper, we propose a quorum-based adaptive dissemination algorithm (QADA) for the critical data in the monitoring-based applications of massive IoTs. To design QADA, we first design a new stepped-triangular grid structures (sT-grid) that support data dissemination, then construct a triangular grid overlay in the fog layer on the lower IoT layer and propose the data dissemination algorithm of the publish/subscribe model that adaptively uses triangle grid (T-grid) and sT-grid quorums depending on the mission critical in the overlay constructed to disseminate the critical data, and evaluate its performance as an analytical model.

• Current Applied Physics
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• 제18권11호
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• pp.1327-1337
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• 2018

This paper investigates the vibration behavior of pristine and defected triangular graphene sheets; which has recently attracted the attention of researchers and compare these two types in natural frequencies and sensitivity. Here, the molecular dynamics method has been employed to establish a virtual laboratory for this purpose. After measuring the different parameters obtained by the molecular dynamics approach, these data have been analyzed by using the frequency domain decomposition (FDD) method, and the dominant frequencies and mode shapes of the system have been extracted. By analyzing the vibration behaviors of pristine triangular graphene sheets in four cases (right angle of 45-90-45 configuration, right angle of 60-90-30 configuration, equilateral triangle and isosceles triangle), it has been demonstrated that the natural frequencies of these sheets are higher than the natural frequency of a square sheet, with the same number of atoms, by a minimum of 7.6% and maximum of 26.6%. Therefore, for increasing the resonance range of sensors based on 2D materials, nonrectangular structures, and especially the triangular structure, can be considered as viable candidates. Although the pristine and defective equilateral triangular sheets have the highest values of resonance, the sensitivity of defective (45,90,45) triangular sheet is more than other configurations and then, defective (45,90,45) sheet is the worst choice for sensor applications.

• 정보처리학회논문지:소프트웨어 및 데이터공학
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• 제7권1호
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• pp.25-32
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• 2018

변형물체 시뮬레이션은 강체 시뮬레이션에 비해 많은 연산량을 요구하기 때문에 효과적인 충돌 검사 방법을 필요하다. 그러나 CPU 기반의 충돌 검사 알고리즘을 그대로 GPU 환경에 적용할 경우 GPU의 성능을 제대로 사용할 수 없기 때문에 GPU 환경에 최적화된 충돌 감지 알고리즘과 자료구조가 필요하다. 따라서 본 연구에서는 변형 물체 표현을 위해 널리 사용되고 있는 질량-스프링 시스템을 위한 GPU 기반의 병렬 충돌 감지 알고리즘을 제안한다. 제안하는 방법은 AABB-옥트리 구조를 이용한 GPU 기반의 컬링 알고리즘을 통해 충돌 감지 비용을 줄이는 병렬 알고리즘과 자료 구조를 사용하였다. 본 연구에서는 모든 삼각형 쌍의 충돌을 병렬로 검사하는 기존 방법과의 비교실험을 통하여 제안 알고리즘의 효율성을 입증하였다. 실험결과, 제안된 방법은 기존의 방법에 비해서 평균 약 24%의 성능 개선을 보였다. 따라서 제안하는 방법을 통해서 변형 물체에 대한 실시간 시뮬레이션의 성능 개선이 가능할 것으로 기대한다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 학술대회 논문집 정보 및 제어부문
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• pp.337-339
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• 2004

In this paper, we discuss optimal design of Fuzzy Polynomial Neural Networks by means of Genetic Algorithms(GAs). Proceeding the layer, this model creates the optimal network architecture through the selection and the elimination of nodes by itself. So, there is characteristic of flexibility. We use a triangle and a Gaussian-like membership function in premise part of rules and design the consequent structure by constant and regression polynomial (linear, quadratic and modified quadratic) function between input and output variables. GAs is applied to improve the performance with optimal input variables and number of input variables and order. To evaluate the performance of the GAs-based FPNNs, the models are experimented with the use of Medical Imaging System(MIS) data.