scholarly journals A biometric for shark dorsal fins based on boundary descriptor matching

10.29007/bd51 ◽  
2019 ◽  
Author(s):  
Taina Coleman ◽  
Jucheol Moon
Keyword(s):  
Coordinate System ◽  
Bipartite Graph ◽  
Recent Progress ◽  
Perfect Matching ◽  
Minimum Weight ◽  
Cutting Edge ◽  
Experimental Results ◽  
Visual Data ◽  
Noninvasive Methods ◽  
Animal Biometrics

Recent progress in animal biometrics has revolutionized wildlife research. Cutting edge techniques allow researchers to track individuals through noninvasive methods of recognition that are not only more reliable, but also applicable to large, hard-to-find, and otherwise difficult to observe animals. In this research, we propose a metric for boundary descriptors based on bipartite perfect matching applied in shark dorsal fins. In order to identify a shark, we first take a fin contour and transform it to a normalized coordinate system so that we can analyze images of sharks regardless of orientation and scale. Finally, we propose a metric scheme that performs a minimum weight perfect matching in a bipartite graph. The experimental results show that our metric is applicable to identify and track individuals from visual data.

scholarly journals Quantitative Expression of the Burial Phenomenon of Deep Seafloor Manganese Nodules

Minerals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 227
Author(s):  
Akira Tsune
Keyword(s):  
Recent Progress ◽  
Mathematical Expression ◽  
Mineral Resources ◽  
Economic Potential ◽  
Visual Data ◽  
Manganese Nodules ◽  
Quantitative Expression ◽  
Size Number ◽  
Polymetallic Nodules ◽  
Geological Origin

Manganese (polymetallic) nodules on the deep seafloor in the open ocean have attracted great interest because of their economic potential. Visual data on nodules found on the deep seafloor such as photographs and videos have increased exponentially with the recent progress of related technologies. These data are expected to reflect useful information for estimating these mineral resources, as well as understanding their geological origin. Although the size, number, and coverage of manganese nodules have been measured in seafloor images, the burial of such nodules has not been sufficiently examined. This paper focuses on mathematical expression of the burial of the manganese nodules and attempts to quantitatively elucidate relations among burial degree and nodule geological parameters. The results, that is, a dataset obtained by calculations of relations among parameters, are also utilized for considerations of quantitative expression of burial. These considerations are expected to contribute to a better understanding of the geological origin of manganese nodules.

scholarly journals Face-Width of Pfaffian Braces and Polyhex Graphs on Surfaces

10.37236/3540 ◽  
2014 ◽  
Vol 21 (4) ◽  
Author(s):  
Dong Ye ◽  
Heping Zhang
Keyword(s):  
Bipartite Graph ◽  
Polynomial Time ◽  
Perfect Matching ◽  
Cartesian Product ◽  
Perfect Matchings ◽  
Face Width ◽  
Graphs On Surfaces ◽  
Positive Genus ◽  
Pfaffian Graph

A graph $G$ with a perfect matching is Pfaffian if it admits an orientation $D$ such that every central cycle $C$ (i.e. $C$ is of even size and $G-V(C)$ has a perfect matching) has an odd number of edges oriented in either direction of the cycle. It is known that the number of perfect matchings of a Pfaffian graph can be computed in polynomial time. In this paper, we show that every embedding of a Pfaffian brace (i.e. 2-extendable bipartite graph)  on a surface with a positive genus has face-width at most 3.  Further, we study Pfaffian cubic braces and obtain a characterization of Pfaffian polyhex graphs: a polyhex graph is Pfaffian if and only if it is either non-bipartite or isomorphic to the cube, or the Heawood graph, or the Cartesian product $C_k\times K_2$ for even integers $k\ge 6$.

Research on Pose Estimation for Electric Vehicle’s Fast-Swap Battery Box Based on Visual Information

2012 ◽  
Vol 253-255 ◽  
pp. 2252-2257
Author(s):  
Yu Ming Wu ◽  
Shuo Liu ◽  
Gao Yang Zhang ◽  
Xiao Yan Yin ◽  
Ming Yu Zhao ◽  
...  
Keyword(s):  
Coordinate System ◽  
Pose Estimation ◽  
Visual Information ◽  
Experimental Results ◽  
Noise Effects ◽  
Simulation Results ◽  
Camera Coordinate System

For the reason of difficult to get battery box pose information, we research the battery box pose measure method based on visual information. We get the coplanar four points at the lines constraints which extracted form image. We get the pose relationship between the battery box coordinate system and camera coordinate system, and then calculate the average of the measure results to reduce noise effects for measure precision. Simulation results show that the method through calculate average of the measure results can effectively reduce noise effects for measure accuracy. The actual experimental results show that the pose estimate accuracy is meet robot requirements for battery swap.

Rainbow Perfect Matchings in Complete Bipartite Graphs: Existence and Counting

2013 ◽  
Vol 22 (5) ◽  
pp. 783-799 ◽  
Author(s):  
GUILLEM PERARNAU ◽  
ORIOL SERRA
Keyword(s):  
Bipartite Graph ◽  
High Probability ◽  
Perfect Matching ◽  
Complete Bipartite Graph ◽  
Bipartite Graphs ◽  
Perfect Matchings ◽  
Asymptotic Enumeration ◽  
Complete Bipartite Graphs ◽  
Edge Colourings ◽  
Square Matrix

A perfect matchingMin an edge-coloured complete bipartite graphKn,nis rainbow if no pair of edges inMhave the same colour. We obtain asymptotic enumeration results for the number of rainbow perfect matchings in terms of the maximum number of occurrences of each colour. We also consider two natural models of random edge-colourings ofKn,nand show that if the number of colours is at leastn, then there is with high probability a rainbow perfect matching. This in particular shows that almost every square matrix of ordernin which every entry appearsntimes has a Latin transversal.

MICROWAVE FLUCTUATIONS IN ELECTRON GAS WITH PAIR COLLISIONS

2001 ◽  
Vol 01 (01) ◽  
pp. R81-R100 ◽  
Author(s):  
R. KATILIUS ◽  
A. MATULIONIS
Keyword(s):  
Monte Carlo ◽  
Electric Fields ◽  
Monte Carlo Methods ◽  
Recent Progress ◽  
Electron Gas ◽  
Experimental Results ◽  
Hot Electron ◽  
Electron Collisions ◽  
Noise Characteristics ◽  
Microwave Noise

The paper overviews recent progress in the field of hot-electron microwave noise and fluctuations with an emphasis on contribution due to inter-electron collisions that are inevitable in doped semi-conductors at a relatively high density of mobile electrons. A special attention is paid to the problem of hot-electron diffusion in the range of electric fields where inter-electron collisions are important and Price's relation connecting diffusion and noise characteristics is not necessarily valid. The basic and up-to-date information is presented on methods and advances in the field where combined analytic and Monte Carlo methods of investigation are indispensable while seeking coherent understanding of experimental results.

Research on Auto Matching of Measuring Points Data with CAD Model for Hull Blocks

2013 ◽  
Vol 683 ◽  
pp. 680-685
Author(s):  
Gang Ren ◽  
Pin Le Qin ◽  
Yan Lin
Keyword(s):  
Minimum Distance ◽  
Prior Information ◽  
Perfect Matching ◽  
Measurement Data ◽  
Experimental Results ◽  
Cad Model ◽  
A Algorithm ◽  
Total Station ◽  
Manufacturing Errors ◽  
Pca Algorithm

Precise matching of measurement data with CAD model for hull block is the key to accurately analysis manufacturing errors and rationally evaluate manufacturing precision. A algorithm to automatically match measurement data with CAD model is proposed. The measurement data is measured by total station, which is currently used in the shipyard. The algorithm is divided into two steps. One is rough matching and another is refined matching. Rough matching that adopts PCA algorithm can narrow the dislocation between measurement data and CAD model. The pair-wise points are matched by searching minimum distance. Initialized by the former result based on rough matching, refined matching that adopts Euler rotation theory leads to perfect matching by translating and rotating the measured points. Experimental results show that the proposed algorithm can automatically match measurement data with CAD model without prior information on transformation, and evaluates manufacturing precision of hull blocks accurately, and provides an instructive basis for subsequent assembly.

scholarly journals Matchings and Hamilton cycles in hypergraphs

2005 ◽  
Vol DMTCS Proceedings vol. AE,... (Proceedings) ◽  
Author(s):  
Daniela Kühn ◽  
Deryk Osthus
Keyword(s):  
Bipartite Graph ◽  
Perfect Matching ◽  
Minimum Degree ◽  
Hamilton Cycle ◽  
Uniform Hypergraph ◽  
Hamilton Cycles ◽  
Uniform Hypergraphs ◽  
International Audience

International audience It is well known that every bipartite graph with vertex classes of size $n$ whose minimum degree is at least $n/2$ contains a perfect matching. We prove an analogue of this result for uniform hypergraphs. We also provide an analogue of Dirac's theorem on Hamilton cycles for $3$-uniform hypergraphs: We say that a $3$-uniform hypergraph has a Hamilton cycle if there is a cyclic ordering of its vertices such that every pair of consecutive vertices lies in a hyperedge which consists of three consecutive vertices. We prove that for every $\varepsilon > 0$ there is an $n_0$ such that every $3$-uniform hypergraph of order $n \geq n_0$ whose minimum degree is at least $n/4+ \varepsilon n$ contains a Hamilton cycle. Our bounds on the minimum degree are essentially best possible.

scholarly journals Study on Comprehensive Calibration and Image Sieving for Coal-Gangue Separation Parallel Robot

2020 ◽  
Vol 10 (20) ◽  
pp. 7059
Author(s):  
Deyong Shang ◽  
Yuwei Wang ◽  
Zhiyuan Yang ◽  
Junjie Wang ◽  
Yue Liu
Keyword(s):  
Coordinate System ◽  
Image Recognition ◽  
Calculation Method ◽  
Calibration Method ◽  
Parallel Robot ◽  
Recognition System ◽  
Conveyor Belt ◽  
Coal Gangue ◽  
Experimental Results ◽  
Robot Calibration

Online sorting robots based on image recognition are key pieces of equipment for the intelligent washing of coal mines. In this paper, a Delta-type, coal gangue sorting, parallel robot is designed to automatically identify and sort scattered coal and gangue on conveyor belts by configuring the image recognition system. Robot calibration technology can reduce the influence of installation error on system accuracy and provides the basis for the robot to accurately track and grab gangue. Due to the fact that the angle deflection error between the conveyor belt coordinate system and the robot coordinate system is not considered in the traditional conveyor belt calibration method, an improved comprehensive calibration method is put forward in this paper. Firstly, the working principle and image recognition and positioning process of the Delta coal gangue sorting robot are introduced. The scale factor parameter Factorc of the conveyor encoder is adopted to characterize the relationship between the moving distance of the conveyor and the encoder. The conveyor belt calibration experiment is described in detail. The transformation matrix between the camera, the conveyor belt, and the robot are obtained after establishment of the three respective coordinate systems. The experimental results show that the maximum cumulative deviation of traditional calibration method is 13.841 mm and the comprehensive calibration method is 3.839 mm. The main innovation of the comprehensive calibration is such that the accurate position of each coordinate in the robot coordinate system can be determined. This comprehensive calibration method is simple and feasible, and can effectively improve system calibration accuracy and reduce robot installation error on the grasping accuracy. Moreover, a calculation method to eliminate duplicate images is put forward, with the frame rate of the vision system set at seven frames per second to avoid image repetition acquisition and missing images. The experimental results show that this calculation method effectively improves the processing efficiency of the recognition system, thereby meeting the demands of the grab precision of coal gangue separation engineering. The goal revolving around “safety with few people and safety with none” can therefore be achieved in coal gangue sorting using robots.

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