Research on detection and location of weak edge signals

AbstractIn this paper we consider two natural notions of connectivity for hypergraphs: weak and strong. We prove that the strong vertex connectivity of a connected hypergraph is bounded by its weak edge connectivity, thereby extending a theorem of Whitney from graphs to hypergraphs. We find that, while determining a minimum weak vertex cut can be done in polynomial time and is equivalent to finding a minimum vertex cut in the 2-section of the hypergraph in question, determining a minimum strong vertex cut is NP-hard for general hypergraphs. Moreover, the problem of finding minimum strong vertex cuts remains NP-hard when restricted to hypergraphs with maximum edge size at most 3. We also discuss the relationship between strong vertex connectivity and the minimum transversal problem for hypergraphs, showing that there are classes of hypergraphs for which one of the problems is NP-hard, while the other can be solved in polynomial time.

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Algorithm for the Detection of Feeble Edge of Complex Image

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.487.915 ◽

2012 ◽

Vol 487 ◽

pp. 915-919

Author(s):

Xi Yun Wang

Keyword(s):

Edge Detection ◽

Ant Colony Algorithm ◽

Detection Algorithm ◽

Information Value ◽

Ant Colony ◽

Position Detection ◽

Canny Edge ◽

Key Steps ◽

Improved Ant Colony Algorithm ◽

Weak Edge

Image weak edge detection has a wide application. An improved ant colony algorithm is used for image edge detection . When image background is very complex ,the weak edge detection is more difficult. Around the key steps in the existing ant colony algorithm , we propose two improved methods. First, the expression of pheromone has been improved, and second, to improve the heuristic information value is calculated. Finally, the improved ant colony algorithm with the traditional Canny edge detection algorithm are compared.The improved edge detection experiments show that the new algorithm is position detection accurate, continuity, and the advantages of less interference.

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Fast Medical Image Segmentation Using Energy-Based Method

Pattern and Data Analysis in Healthcare Settings - Advances in Medical Technologies and Clinical Practice ◽

10.4018/978-1-5225-0536-5.ch003 ◽

2017 ◽

pp. 35-60 ◽

Cited By ~ 7

Author(s):

Ramgopal Kashyap ◽

Pratima Gautam

Keyword(s):

Level Set ◽

Active Contours ◽

Medical Images ◽

Correct Diagnosis ◽

Medical Image Segmentation ◽

Geodesic Active Contour ◽

The Will ◽

Contour Models ◽

Level Set Model ◽

Weak Edge

Medical applications became a boon to the healthcare industry. It needs correct and fast segmentation associated with medical images for correct diagnosis. This assures high quality segmentation of medical images victimization. The Level Set Method (LSM) is a capable technique, however the quick process using correct segments remains difficult. The region based models like Active Contours, Globally Optimal Geodesic Active Contours (GOGAC) performs inadequately for intensity irregularity images. During this cardstock, we have a new tendency to propose an improved region based level set model motivated by the geodesic active contour models as well as the Mumford-Shah model. So that you can eliminate the re-initialization process of ancient level set model and removes the will need of computationally high priced re-initialization. Compared using ancient models, our model are sturdier against images using weak edge and intensity irregularity.

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Weak edge enhancement based on contextual modulation of non-classical receptive field

10.1117/12.2205463 ◽

2015 ◽

Author(s):

Jie Xiao ◽

Chao Cai

Keyword(s):

Receptive Field ◽

Edge Enhancement ◽

Contextual Modulation ◽

Classical Receptive Field ◽

Weak Edge

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Crystal Structures and Thermal Behavior of Isostructural Bis(dibenzyldimethylammonium) Tetrachlorometallate [M = Mn(II), Co(II), Ni(II) and Zn(II)] Solvates Crystallized from Acetonitrile and/or Methanol Solutions

Zeitschrift für Naturforschung B ◽

10.1515/znb-2007-0105 ◽

2007 ◽

Vol 62 (1) ◽

pp. 28-34 ◽

Cited By ~ 2

Author(s):

Sara Busi ◽

Roland Fröhlich ◽

Manu Lahtinen ◽

Jussi Valkonen ◽

Kari Rissanen

Keyword(s):

Crystal Structures ◽

Solvent Molecule ◽

Monoclinic Space Group ◽

Asymmetric Unit ◽

Π Interactions ◽

Copper Compounds ◽

Methanol Solutions ◽

Cell Dimensions ◽

Unit Cell Dimensions ◽

Weak Edge

Five isostructural bis(dibenzyldimethylammonium) tetrachlorometallate solvate complexes [M = Mn(II), Co(II), Ni(II) or Zn(II)] were crystallized from acetonitrile and/or methanol solutions. The crystal structures are compared to those of the analogous, isostructural copper compounds (X = Cl or Br) reported earlier. The complexes crystallize in the monoclinic space group P21/n with Z = 4, and unit cell dimensions of a ≈ 14.1, b ≈ 16.1, c ≈ 15.7 °A and β ≈ 108 - 109°. The asymmetric unit of these compounds contains one MCl42− anion, two Bz2Me2N+ cations in theW-conformation and one half of a disordered solvent molecule (acetonitrile or methanol). The geometry of the MCl42− anion is close to tetrahedral, whereas the analogous copper anions appeared in distorted tetrahedral geometries with trans angles of 124.4° for X = Cl and 123.6° for X = Br. In addition to the ionic interactions between the cations and the anions, the components are connected by weak C-H· · · Cl− bonds. As a distinction between the two crystallographically independent cations in the asymmetric unit, one type of independent cations form long chains via weak edge to face π-π interactions along the crystallographic b axis, whereas the other type of cations are not tied together by such weak π-π interactions. The coordination around the N atoms is also nearly tetrahedral, and neither static nor dynamic disorder of the Bz2Me2N+ cations can be observed. The complexes are thermally stable and melt close to the decomposition temperatures in the range 170 - 205 °C.

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