Modern robotic researches propose various machine vision methods for accomplishing robotic tasks. The recognition quality in these tasks is very important for successful performance. A large number of them use fiducia...
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ISBN:
(纸本)9781728169262
Modern robotic researches propose various machine vision methods for accomplishing robotic tasks. The recognition quality in these tasks is very important for successful performance. A large number of them use fiducial marker systems as a main element of algorithms. However, only a few researches are comparing standard marker systems. This paper is dedicated to the comparison of AprilTag and ArUco markers resistance to rotations in the presence of synthetic noise. Experiments were conducted in ROS/Gazebo virtual environment in order to provide a fair comparison of marker detection and recognition algorithms while eliminating external environment conditions that influence the algorithms' performance. The presented virtual environments allow collecting a significant amount of data by experiment process automation. Different levels of additive white Gaussian noise were applied to input sensory data in order to simulate the imperfection of real digital cameras. The main contribution of the paper is the systematic comparison of AprilTag and ArUco markers for rotation resistance in the presence of optical sensor noise.
A k-colouring of a graph G is an assignment of at most k colours to the vertices of G so that adjacent vertices are assigned different colours. The reconfiguration graph of the k-colourings, R k (G), is the graph whos...
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A k-colouring of a graph G is an assignment of at most k colours to the vertices of G so that adjacent vertices are assigned different colours. The reconfiguration graph of the k-colourings, R k (G), is the graph whose vertices are the k-colourings of G and two colourings are joined by an edge in R k (G) if they differ in colour on exactly one vertex. For a k-colourable graph G, we investigate the connectivity and diameter of R k+1 (G). It is known that not all weakly chordal graphs have the property that R k+1 (G) is connected. On the other hand, R k+1 (G) is connected and of diameter O(n 2 ) for several subclasses of weakly chordal graphs such as chordal, chordal bipartite, and P 4 -free graphs. We introduce a new class of graphs called OAT graphs that extends the latter classes and in fact extends outside the class of weakly chordal graphs. OAT graphs are built from four simple operations, disjoint union, join, and the addition of a clique or comparable vertex. We prove that if G is a k-colourable OAT graph, then R k+1 (G) is connected with diameter O(n 2 ). Furthermore, we give polynomial time algorithms to recognize OAT graphs and to find a path between any two colourings in R k+1 (G). Feghali and Fiala defined a subclass of weakly chordal graphs, called compact graphs, and proved that for every k-colourable compact graph G, R k+1 (G) is connected with diameter O(n 2 ). We prove that the class of OAT graphs properly contains the class of compact graphs. Feghali and Fiala also asked if for a k-colourable (P 5, co-P 5, C 5 )-free graph G, R k+1 (G) is connected with diameter O(n 2 ). We answer this question in the positive for the subclass of P 4 -sparse graphs, which are the (P 5, co-P 5, C 5, P, co-P, fork, co-fork)-free graphs.
A graph with n vertices is 1-planar if it can be drawn in the plane such that each edge is crossed at most once, and is optimal if it has the maximum of edges. We show that optimal 1-planar graphs can be recognized in...
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A graph with n vertices is 1-planar if it can be drawn in the plane such that each edge is crossed at most once, and is optimal if it has the maximum of edges. We show that optimal 1-planar graphs can be recognized in linear time. Our algorithm implements a graph reduction system with two rules, which can be used to reduce every optimal 1-planar graph to an irreducible extended wheel graph. The graph reduction system is non-deterministic, constraint, and non-confluent.
Let t be an involution in GL(n, q) whose fixed point space E+ has dimension k between n/3 and 2n/3. For each g is an element of GL(n, q) such that tt(9) has even order, contains a unique involution z(g) which commute...
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Let t be an involution in GL(n, q) whose fixed point space E+ has dimension k between n/3 and 2n/3. For each g is an element of GL(n, q) such that tt(9) has even order, < tt(g)> contains a unique involution z(g) which commutes with t. We prove that, with probability at least c/log n (for some c > 0), the restriction z(g)(vertical bar E+) is an involution on E+ with fixed point space of dimension between k/3 and 2k/3. This result has implications in the analysis of the complexity of recognition algorithms for finite classical groups in odd characteristic. We discuss how similar results for involutions in other finite classical groups would solve a major open problem in our understanding of the complexity of constructing involution centralisers in those groups. (C) 2017 Elsevier Inc. All rights reserved.
A plant identification system which is designed to integrate local edge algorithms with other classical recognition algorithms in a prototype system is mainly composed of the following two parts. One is the system int...
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ISBN:
(纸本)9781538684979
A plant identification system which is designed to integrate local edge algorithms with other classical recognition algorithms in a prototype system is mainly composed of the following two parts. One is the system interface and another is algorithm embedding. A convenient visual environment is provided for users by this system interface, and algorithm functions and other auxiliary functions are integrated. After selecting the system integration algorithms and setting the necessary parameters, the tested plant image is automatically recognized by this system and the corresponding plant images from the database with a brief description are displayed. The tested common green images can be accurately identified and good identification results are obtained by this system.
The measuring accuracy of the TDR cable length measurement system relies on the recognition of the reflected wave. The reflected wave is susceptible to be affected by noise and the reflected wave detecting error is co...
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ISBN:
(纸本)9783642293894
The measuring accuracy of the TDR cable length measurement system relies on the recognition of the reflected wave. The reflected wave is susceptible to be affected by noise and the reflected wave detecting error is comparatively large. In order to correctly identifying and detecting the reflected wave, this dissertation studies four reflected wave recognition algorithms, which are established according to the threshold method, centroid method, polynomial fitting method and the wavelet modulus maxima method respectively. The advantages and disadvantages of these algorithms are analyzed. The repeatability and accuracies of the reflected wave arrival time for these algorithms are compared through practical applications.
A graph G = (V, E) is a threshold tolerance graph if each vertex v is an element of V can be assigned a weight w(v) and a tolerance t(v), such that two vertices x, y is an element of V are adjacent if w(x) + w(y) >...
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A graph G = (V, E) is a threshold tolerance graph if each vertex v is an element of V can be assigned a weight w(v) and a tolerance t(v), such that two vertices x, y is an element of V are adjacent if w(x) + w(y) >= min(t(x), t(y)). Currently, the most efficient recognition algorithm for threshold tolerance graphs is the algorithm of Monma, Reed, and Trotter which has an O(n(4)) runtime. We give an O(n(2)) algorithm for recognizing threshold tolerance and their complements, the co-threshold tolerance (co-TT) graphs, resolving an open question of Golumbic, Weingarten, and Limouzy. (C) 2015 Elsevier B.V. All rights reserved.
The main role in the task of process remote sensing data of the Earth surface are played algorithms of forming and classification those data. From the statistical point of view the solution is based on the maximum-lik...
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ISBN:
(纸本)9781509054541
The main role in the task of process remote sensing data of the Earth surface are played algorithms of forming and classification those data. From the statistical point of view the solution is based on the maximum-likelihood method. The paper presents analytical equations for likelihood coefficients and the structural scheme of their forming in the solution of radar signal recognition. To analyze the efficiency of the proposed algorithms are found boundary equations for probability calculating of correct signals with the usage of Chernoff-Kailath ratios. This ratios evaluate the upper and lower probability boundaries of correct and incorrect decisions in the case of classification of optional class number from different type surfaces.
In the process of solving a wide range of tasks concerning the Earth surface remote sensing and its state monitoring, the main role is played by the algorithm of the surface image forming and the algorithm of images a...
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ISBN:
(纸本)9781467389792
In the process of solving a wide range of tasks concerning the Earth surface remote sensing and its state monitoring, the main role is played by the algorithm of the surface image forming and the algorithm of images and their fragments classification as well. From the statistical point of view the solution is based on the maximum-likelihood method. The paper presents analytical equations for likelihood coefficients and the structural scheme of their forming in the solution of radar signal recognition. To analyze the efficiency of the proposed algorithms are found boundary equations for probability calculating of correct signals with the usage of Chernoff-Kailath ratios. This ratios evaluate the upper and lower probability boundaries of correct and incorrect decisions in the case of classification of optional class number from different type surfaces.
In the process of solving a wide range of tasks concerning the Earth surface remote sensing and its state monitoring, the main role is played by the algorithm of the surface image forming and the algo
ISBN:
(纸本)9781467389808
In the process of solving a wide range of tasks concerning the Earth surface remote sensing and its state monitoring, the main role is played by the algorithm of the surface image forming and the algo
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