• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2004년도 ICCAS
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• pp.2017-2022
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• 2004

Data association is a process that matches a recent observation with known data set, which is used for the localization of mobile robots. Edges in topological maps have rich information which can be used for the data association. However, no systematic approach on using the edge data for data association has been reported. This paper proposes a systematic way of utilizing the edge data for data association. First, we explain a Local Generalized Voronoi Angle(LGA) to represent the edge data in 1-dimension. Second, we suggest a key factor extraction procedure from the LGA to reduce the number by $2^7-2^8$ times, for computational efficiency using the wavelet transformation. Finally we propose a way of data association using the key factors of the LGA. Simulations show that the proposed data association algorithm yields higher probability for similar edges in computationally efficient manner.

• 대한수학회지
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• 제55권5호
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• pp.1157-1175
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• 2018

For a switched system with constraint on switching sequences, which is also called a subshift action, on a metric space not necessarily compact, two kinds of topological entropies, average topological entropy and maximal topological entropy, are introduced. Then we give some properties of those topological entropies and estimate the bounds of them for some special systems, such as subshift actions generated by finite smooth maps on p-dimensional Riemannian manifold and by a family of surjective endomorphisms on a compact metrizable group. In particular, for linear switched systems on ${\mathbb{R}}^p$, we obtain a better upper bound, by joint spectral radius, which is sharper than that by Wang et al. in [42,43].

• Kyungpook Mathematical Journal
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• 제45권1호
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• pp.13-19
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• 2005

In this paper we introduce the notions of g-regularity and g-normality in fuzzy topological spaces. We obtain some characterizations and several preservation theorems of such spaces.

• 대한수학회보
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• 제37권1호
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• pp.21-36
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• 2000

In this article we study the relation between subinvariant submean and normal structure in a locally convex topological vector space. This extends in a natural way a result obtained recently by Lau and Takahashi. Our approach also follows closely theirs.

• 한국정보과학회논문지:데이타베이스
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• 제29권5호
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• pp.358-366
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• 2002

특징정보를 기반으로 한 유사 이미지 검색은 이미지 데이타베이스에 있어서 중요한 과제의 하나이다. 이미지 데이타의 특징정보는 각 이미지를 식별하는데 유용한 정보이다. 본 논문에서는 자기 조직화 맵 기반의 고속 k-NN 탐색 알고리즘을 제안한다. 자기 조직화 맵은 고차원 특징벡터를 2차원 공간에 맵핑하여 위상특징 맵을 생성한다. 위상특징 맵은 입력 데이타의 특징공간과 상호관계(유사성)를 가지고 있으며, 인접노드에 서로 유사한 특징벡터가 클러스터링된다. 그러므로 위상특징 맵상의 각 노드에는 노드 벡터와 각 노드벡터에 가장 가까운 유사 이미지가 분류된다. 이러한 자기 조직화 맵에 의한 유사 이미지 분류결과에 대하여 k-NV 탐색을 구현하기 위하여, (1) 위상특징 맵에 대한 접근방법, (2) 고속탐색을 위한 pruning strategy의 적용을 실현하였다. 본 연구에서는 실험을 통하여 실제 이미지로부터 추출한 색상 특징을 사용하여 제안한 알고리즘의 성능을 평가함으로써 유사 이미지 검색에 유효한 견과를 얻을 수 있었다.

• 대한수학회보
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• 제12권1호
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• pp.5-6
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• 1975

• 대한수학회지
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• 제24권1호
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• pp.59-63
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• 1987

• 제어로봇시스템학회논문지
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• 제8권6호
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• pp.492-497
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• 2002

Map building is the process of modeling the robot's environment. The map is usually built based on a grid-based or topological approach, which has its own merits and demerits. These two methods, therefore, can be integrated to provide a better way of map building, which compensates for each other's drawbacks. In this paper, a method of building the topological map based on the occupancy grid map through a Voronoi diagram is presented and verified by various simulations. This Voronoi diagram is made by using a labeled Voronoi diagram scheme which is suitable for the occupancy grid maps. It is shown that the Proposed method is efficient and simple fur building a topological map. The simple path-planning problem is simulated and experimented verify validity of the proposed approach.

• 로봇학회논문지
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• 제6권3호
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• pp.247-254
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• 2011

This paper presents a method of sonar grid map matching for topological place recognition. The proposed method provides an effective rotation invariant grid map matching method. A template grid map is firstly extracted for reliable grid map matching by filtering noisy data in local grid map. Using the template grid map, the rotation invariant grid map matching is performed by Ring Projection Transformation. The rotation invariant grid map matching selects candidate locations which are regarded as representative point for each node. Then, the topological place recognition is achieved by calculating matching probability based on the candidate location. The matching probability is acquired by using both rotation invariant grid map matching and the matching of distance and angle vectors. The proposed method can provide a successful matching even under rotation changes between grid maps. Moreover, the matching probability gives a reliable result for topological place recognition. The performance of the proposed method is verified by experimental results in a real home environment.

• 대한수학회보
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• 제60권3호
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• pp.659-675
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• 2023

Let K be an algebraically closed field of characteristic 0 and let f be a non-fibered planar quadratic polynomial map of topological degree 2 defined over K. We assume further that the meromorphic extension of f on the projective plane has the unique indeterminacy point. We define the critical pod of f where f sends a critical point to another critical point. By observing the behavior of f at the critical pod, we can determine a good conjugate of f which shows its statue in GIT sense.