• 제목/요약/키워드: local compactness

검색결과 21건 처리시간 0.03초

Fuzzy Hyperpsaces : Fuzzy Compactness

  • K.Hur;C.J. Rhee;J. H. Ryou
    • 한국지능시스템학회:학술대회논문집
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    • 한국퍼지및지능시스템학회 2003년도 춘계 학술대회 학술발표 논문집
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    • pp.41-44
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    • 2003
  • First, we investigate some properties of fuzzy compactness. Second, we introduce the concept of fuzzy local compactness in fuzzy topological space and study some of its properties. Finally, we investigate some relations between F-compactness in fuzzy topological spaces and one in fuzzy hyperspaces.

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슈퍼픽셀의 밀집도 및 텍스처정보를 이용한 DBSCAN기반 칼라영상분할 (A Method of Color Image Segmentation Based on DBSCAN(Density Based Spatial Clustering of Applications with Noise) Using Compactness of Superpixels and Texture Information)

  • 이정환
    • 디지털산업정보학회논문지
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    • 제11권4호
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    • pp.89-97
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    • 2015
  • In this paper, a method of color image segmentation based on DBSCAN(Density Based Spatial Clustering of Applications with Noise) using compactness of superpixels and texture information is presented. The DBSCAN algorithm can generate clusters in large data sets by looking at the local density of data samples, using only two input parameters which called minimum number of data and distance of neighborhood data. Superpixel algorithms group pixels into perceptually meaningful atomic regions, which can be used to replace the rigid structure of the pixel grid. Each superpixel is consist of pixels with similar features such as luminance, color, textures etc. Superpixels are more efficient than pixels in case of large scale image processing. In this paper, superpixels are generated by SLIC(simple linear iterative clustering) as known popular. Superpixel characteristics are described by compactness, uniformity, boundary precision and recall. The compactness is important features to depict superpixel characteristics. Each superpixel is represented by Lab color spaces, compactness and texture information. DBSCAN clustering method applied to these feature spaces to segment a color image. To evaluate the performance of the proposed method, computer simulation is carried out to several outdoor images. The experimental results show that the proposed algorithm can provide good segmentation results on various images.

Salient Object Detection Based on Regional Contrast and Relative Spatial Compactness

  • Xu, Dan;Tang, Zhenmin;Xu, Wei
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제7권11호
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    • pp.2737-2753
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    • 2013
  • In this study, we propose a novel salient object detection strategy based on regional contrast and relative spatial compactness. Our algorithm consists of four basic steps. First, we learn color names offline using the probabilistic latent semantic analysis (PLSA) model to find the mapping between basic color names and pixel values. The color names can be used for image segmentation and region description. Second, image pixels are assigned to special color names according to their values, forming different color clusters. The saliency measure for every cluster is evaluated by its spatial compactness relative to other clusters rather than by the intra variance of the cluster alone. Third, every cluster is divided into local regions that are described with color name descriptors. The regional contrast is evaluated by computing the color distance between different regions in the entire image. Last, the final saliency map is constructed by incorporating the color cluster's spatial compactness measure and the corresponding regional contrast. Experiments show that our algorithm outperforms several existing salient object detection methods with higher precision and better recall rates when evaluated using public datasets.

공간구문론을 활용한 도시 압축지수 산정에 관한 연구: 소멸위험도시를 중심으로 (A Study on Calculation of Urban Compactness Index Considering Space Syntax: Focusing on the Declining Local Cities)

  • 하지혜;강정은
    • 한국지리정보학회지
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    • 제25권3호
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    • pp.29-58
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    • 2022
  • 최근 우리나라는 인구감소 문제를 겪으며 기존의 외연적 확산을 지향하는 개발방식은 주택, 기반시설의 공급과잉, 부동산 방치 등의 다양한 도시문제를 발생시키고 있다. 이를 최소화할 수 있는 해결책으로 도시기능을 주요 거점에 모으는 압축적이고 고밀의 공간구조로의 전환이 촉구되고 있다. 그러나 단순 물리적 압축이 아닌 오늘날의 인구구조 변화, 산업구조의 변화 등에 따른 기능적 연계성 및 연결성을 고려한 압축도시가 필요하다. 이러한 관점에서 본 연구는 저출산, 고령화, 인구감소 등으로 인하여 소멸위기를 겪고 있는 국내 소멸위험도시들의 압축성을 측정하고 공간구조적 특성을 살펴보았다. 기존 연구들에서 사용되었던 압축성 평가지표와 더불어 공간구문론을 활용한 연결성 지표를 포함하여 6개의 지표(인구, 토지이용, 생활서비스 접근성, 교통 접근성, 연결성, 집중성)의 압축성을 비교·분석하고, 종합적인 압축지수를 산정하였다. 분석결과, 종합 압축지수 기준 1등급 지역이 2.3%, 2등급 지역이 4.6%, 3등급 지역이 16.09%, 4등급 지역이 43.68%, 5등급 지역이 33.33%로 분류되어 전반적 압축도는 낮은 것으로 나타났다. 이때 압축지수에 영향을 미치는 도시특성이 지역에 따라 다르므로 각 지역의 압축지표별 영향력을 고려하여 소멸위험 대책과 공간정책을 수립할 필요가 있다. 본 연구는 공간구문론을 활용하여 연결성을 측정하였으며, 소멸위험도시들의 압축도를 정량적으로 비교·분석하였다는 점에서 의미가 크며, 소멸위험도시의 공간전략 수립에 중요한 자료로 활용되기를 기대한다.

LOCAL CONNECTEDNESS IN FELL TOPOLOGY

  • Hur, K.;Moon, J.R.;Rhee, C.J.
    • 대한수학회지
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    • 제36권6호
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    • pp.1047-1059
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    • 1999
  • Let $C(X)(C_{K}(X))$ denote the hyperspace of all nonempty closed connected subsets (subcontinua) of a locally compact Haus-dorff space X with the Fell topology. We prove that the following statements are equivalent: (1) X is locally connected. (2) C(X) is locally connected,. (3) C(X) is locally connected at each $E{\in}C_{k}(X).(4) C_{k}(X)$ is locally connected.

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교통 영상에서의 차량 검지를 위한 형상분해 국부영역 임계기법 (Shape-Resolving Local Thresholding for Vehicle Detection)

  • 최호진;박영태
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2000년도 하계종합학술대회 논문집(4)
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    • pp.159-162
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    • 2000
  • Selecting locally optimum thresholds, based on optimizing a criterion composed of the area variation rate and the compactness of the segmented shape, is presented. The method is shown to have the shape-resolving property in the subtraction image, so that overlapped objects may be resolved into bright and dark evidences characterizing each object. As an application a vehicle detection algorithm robust to the operating conditions could be realized by applying simple merging rules to the geometrically correlated bright and dark evidences obtained by this local thresholding.

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How Does the Bar Affect AGN-Driven Quenching within Late-type Galaxies

  • Jee, Woong-Bae;Yoon, Suk-Jin
    • 천문학회보
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    • 제41권2호
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    • pp.59.4-60
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    • 2016
  • Recent galaxy simulations suggest several scenarios in which the inner structure of late-type galaxies (LTGs) is linked to global quenching. Exactly what mechanism governs the bulge quenching is, however, still under debate due to the lack of observational clues. In this study, we utilize a sample of ~1,300 LTGs in the local universe (0.02 < z < 0.2) from SDSS 7, and classify them into star-forming, AGN-hosting, and composite types and into barred and unbarred galaxies. We also examine each subgroup's specific star forming rate (sSFR), stellar mass and compactness using a data set matched with the advanced sSFR catalog by Chang et al. (2015). We find that while star-forming and composite galaxies show no detectable difference between barred and unbarred galaxies, barred AGNs have much lower sSFR than unbarred AGNs at given stellar mass and compactness, Such tendency is stronger for more massive and/or more concentrated galaxies. The results indicate that most AGN-driven quenching is triggered by growth of the bar structure, consistent with the previous simulations of bars.

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