• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2011년도 춘계학술대회 논문집
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• pp.155-156
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• 2011

• 정보처리학회논문지B
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• 제12B권3호
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• pp.265-272
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• 2005

본 논문에서는 특징점 기반 영상 모자익을 위해 보로노이거리를 이용하여 두 영상의 대응점을 신속히 검색하는 영상정합 방법을 제안한다. 먼저 SUSAN 코너 검출기에 의해 정차하고자 하는 영상의 특징점을 추출한 후, 기준 영상의 특징점을 기반으로 우선 순위 기반 보로노이 거리 알고리즘을 이용하여 특징점 사이의 거리 정보를 가지는 보로노이 평면을 생성한다. 모델 영상에서 특징점 위치의 분산값이 가장 큰 곳을 모델 영역으로 선택하여, 모델 영역이 포개지는 기준 영상의 보로노이 평면에서 보로노이 거리의 합이 최소화되는 대응 영역을 큐를 이용한 분할 검색 알고리즘에 의해 찾아낸다. 이 방법의 장점은 새로운 보로노이 거리 계산 알고리즘과 보로노이 평면의 검색범위를 매번 최대 1/4씩 줄여 주는 큐를 이용한 분할 검색 알고리즘을 이용함으로써 보다 신속히 대응점을 찾을 수 있다는 것이다.

• ETRI Journal
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• 제10권3호
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• pp.125-140
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• 1988

Computational geometry has wide applications in pattern recognition, image processing, VLSI design, and computer graphics. Voronoi diagrams in computational geometry possess many important properites which are related to other geometric structures of a set of point. In this pater the design of systolic algorithms for the static and the dynamic Voronoi diagrams is considered. The major motivation for developing the systolic architecture is for VLSI implementation. A new systematic transform technique for designing systolic arrays, in particular, for the problem in computational geometry has been proposed. Following this procedure, a type T systolic array architecture and associated systolic algorithms have been designed for constructing Voronoi diagrams. The functions of the cells in the array are also specified. The resulting systolic array achieves the maximal throughput with O(n) computational complexity.

• 전기학회논문지
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• 제61권1호
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• pp.130-134
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• 2012

In this paper, we propose a space partitioning technique for swarm robots by using the Centroidal Voronoi Tessellation. The proposed method consists of two parts such as space partition and collision avoidance. The space partition for searching a given space is carried out by a density function which is generated by some accidents. The collision avoidance is implemented by the potential field method. Finally, the numerical experiments show the effectiveness and feasibility of the proposed method.

• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송공학회 1999년도 KOBA 방송기술 워크샵 KOBA Broadcasting Technology Workshop
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• pp.69-76
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• 1999

This paper proposes a new region-oriented coding scheme of still images. The scheme first segments an image into homogeneous regions by making use of Voronoi diagrams. Then luminance components in each Voronoi region are encoded using a transform coding technique which employs the Schmidt's orthogonalization method to produce orthonormal basis-functions for arbitrarily shaped regions. In this technique, coding efficiency depends on the properties of initial vectors to be orthogonalized. Therefore we adaptively select a set of initial vectors as well as the order in which these vectors are orthogonalized. Simulation results indicate that the proposed coding scheme achieves higher coding performance with much less computation than the KLT-based scheme which we reported formerly.

• 한국항공우주학회지
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• 제42권2호
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• pp.127-133
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• 2014

본 논문은 무인기의 생존성을 최대화하기 위한 경로점을 결정하는 기법을 제안한다. 본 논문에서 초기 경로점을 선정하기 위해 사용된 Voronoi diagram은 위협의 위치와 크기가 주어져 있을 때, 위협으로부터 최대한 멀리 피해서 가는 경로를 계획하는데 많이 이용되고 있는 기법이다. 하지만 위협의 크기가 서로 다르고, 비행경로가 직선경로로 계획되어야 한다면 실제 경로 계획 시 Voronoi diagram으로는 한계가 있다. 본 논문에서는 Voronoi diagram을 통해 선정한 초기 경로점을 위협의 형태에 맞춰 최적화를 수행하는 방식을 적용하였다. 각 경로점의 인접한 경로점들을 고정시킨 상태에서 경로점을 하나씩 최적화를 수행하는 방식으로 최적화를 수행하였다. 이 방식은 전체 경로점들이 수렴할 때 까지 국소최적화를 반복함으로써, 최적의 경로점을 찾기 위해 소요되는 연산시간을 크게 감소시켰다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2011년도 제42회 하계학술대회
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• pp.1892-1893
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• 2011

본 논문에서는 Centroidal Voronoi Tessellation을 이용하여 군집로봇의 협조탐색을 위한 공간분할기법을 제안한다. 탐색공간은 Centroidal Voronoi Tessellation을 이용하여 분할한다. 전역 경로 계획 및 군집 로봇 간의 충돌 회피는 포텐셜 필드를 이용한다. 탐색공간에 밀도 함수를 사용하여 공간분할의 유동성을 부여한다. 마지막으로, 군집로봇의 협조탐색의 가능성을 시뮬레이션을 통하여 확인한다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 추계학술대회
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• pp.1274-1279
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• 2003

In this paper, a new meshfree technique which improves the numerical integration accuracy is introduced. This new method called the Petrov-Galerkin natural element(PG-NE) is based on the Voronoi diagram and the Delaunay triangulation which is based on the same concept used for conventional natural element method called the Bubnov-Galerkin natural element(BG-NE). But, unlike BG-NE method, the test shape function is differently chosen from the trial shape function. The proposed technique ensures that the numerical integration error is remarkably reduced.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.174-179
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• 2003

Through the simultaneous localization and map building (SLAM) technique, a robot can create maps about its unknown environment while it continuously localizes its position. Grid maps and feature maps have been widely used for SLAM together with application of probability methods and POMDP (partially observed Markov decision process). But this approach based on grid maps suffers from enormous computational burden. Topological maps, however, have drawn more attention these days because they are compact, provide natural interfaces, and are easily applicable to path planning in comparison with grid maps. Some topological SLAM techniques like GVG (generalized Voronoi diagram) were introduced, but it enables the robot to decide only whether the current position is part of GVG branch or not in the GVG algorithm. In this paper, therefore, to overcome these problems, we present a method for updating a global topological map from the local topological maps. These local topological maps are created through a labeled Voronoi diagram algorithm from the local grid map built based on the sensor information at the current robot position. And the nodes of a local topological map can be utilized as the features of the environment because it is robust in light of visibility problem. The geometric information of the feature is applied to the extended Kalman filter and the SLAM in the indoor environment is accomplished. A series of simulations have been conducted using a two-wheeled mobile robot equipped with a laser scanner. It is shown that the proposed scheme can be applied relatively well.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• 제13권2호
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• pp.141-159
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• 2009

In this article, we consider a weighted CVT-based reduced-order modelling for Burgers equation. Brief review of the CVT (centroidal Voronoi tessellation) approaches to reduced-order bases are provided. In CVT-reduced order modelling, we start with a snapshot set just as is done in a POD (Proper Orthogonal Decomposition)-based setting. So far, the CVT was researched with uniform density ($\rho$(y) = 1) to determine the basis elements for the approximatin subspaces. Here, we shall investigate the technique of CVT with nonuniform density as a procedure to determine the basis elements for the approximating subspaces. Some numerical experiments including comparison of two CVT (CVT-uniform and CVT-nonuniform)-based algorithm with numerical results obtained from FEM(finite element method) and POD-based algorithm are reported.