scholarly journals Constructive algorithms for the partial directed weighted improper coloring problem

2016 ◽  
Vol 20 (2) ◽  
pp. 159-188 ◽  
Author(s):  
Alain Hertz ◽  
Romain Montagné ◽  
François Gagnon
2010 ◽  
Vol 02 (03) ◽  
pp. 395-411 ◽  
Author(s):  
JEAN-CLAUDE BERMOND ◽  
FRÉDÉRIC HAVET ◽  
FLORIAN HUC ◽  
CLÁUDIA LINHARES SALES

We study a weighted improper coloring problem motivated by a frequency allocation problem. It consists of associating to each vertex a set of p(v) (weight) distinct colors (frequencies), such that the set of vertices having a given color induces a graph of degree at most k (the case k = 0 corresponds to proper coloring). The objective is to minimize the number of colors. We propose approximation algorithms to compute such a coloring for general graphs. We apply these to obtain good approximation ratio for grid and hexagonal graphs. Furthermore we give exact results for the 2-dimensional grid and the triangular lattice when the weights are all the same.


2006 ◽  
Vol 51 (20) ◽  
pp. 2541-2549 ◽  
Author(s):  
Jin Xu ◽  
Xiaoli Qiang ◽  
Fang Gang ◽  
Kang Zhou

2021 ◽  
pp. 1-11
Author(s):  
Zhaocai Wang ◽  
Dangwei Wang ◽  
Xiaoguang Bao ◽  
Tunhua Wu

The vertex coloring problem is a well-known combinatorial problem that requires each vertex to be assigned a corresponding color so that the colors on adjacent vertices are different, and the total number of colors used is minimized. It is a famous NP-hard problem in graph theory. As of now, there is no effective algorithm to solve it. As a kind of intelligent computing algorithm, DNA computing has the advantages of high parallelism and high storage density, so it is widely used in solving classical combinatorial optimization problems. In this paper, we propose a new DNA algorithm that uses DNA molecular operations to solve the vertex coloring problem. For a simple n-vertex graph and k different kinds of color, we appropriately use DNA strands to indicate edges and vertices. Through basic biochemical reaction operations, the solution to the problem is obtained in the O (kn2) time complexity. Our proposed DNA algorithm is a new attempt and application for solving Nondeterministic Polynomial (NP) problem, and it provides clear evidence for the ability of DNA calculations to perform such difficult computational problems in the future.


2009 ◽  
Vol 20 (4) ◽  
pp. 429-442 ◽  
Author(s):  
Giorgio Lucarelli ◽  
Ioannis Milis ◽  
Vangelis T. Paschos

1994 ◽  
Vol 05 (01) ◽  
pp. 59-66 ◽  
Author(s):  
NEIL BURGESS

A constructive algorithm is presented which combines the architecture of Cascade Correlation and the training of perceptron-like hidden units with the specific error-correcting roles of Upstart. Convergence to zero errors is proved for any consistent classification of real-valued pattern vectors. Addition of one extra element to each pattern allows hyper-spherical decision regions and enables convergence on real-valued inputs for existing constructive algorithms. Simulations demonstrate robust convergence and economical construction of hidden units in the benchmark “N-bit parity” and “twin spirals” problems.


2014 ◽  
Vol 11 (12) ◽  
pp. 2476-2480 ◽  
Author(s):  
Ansheng Ye ◽  
Zhiqiang Zhang ◽  
Xiaoqing Zhou ◽  
Fang Miao

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