Automatic registration of unordered point clouds is the prerequisite forurban reconstruction. However, most of the existing technologies stillsuffer from some limitations. On one hand, most of them are sensitive tonoi...
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Automatic registration of unordered point clouds is the prerequisite forurban reconstruction. However, most of the existing technologies stillsuffer from some limitations. On one hand, most of them are sensitive tonoise and repetitive structures, which makes them infeasible for theregistration of large-scale point clouds. On the other hand, most of themdealing with point clouds with limited overlaps and unpredictablelocation. All these problems make it difficult for registration technology toobtain qualified results in outdoor point cloud. To overcome theselimitations, this paper presents a grid graph-based point cloud registration(GGR) algorithm to align pairwise scans. First, point cloud is divided into aset of 3D grids. We propose a voting strategy to measure the similaritybetween two grids based on feature descriptor, transforming thesuperficial correspondence into 3D grid expression. Next, a graphmatching is proposed to capture the spatial consistency from putativecorrespondences, and graph matching hierarchically refines thecorresponding grids until obtaining point-to-point *** experiments demonstrated that the proposed algorithmobtains good performance in terms of successful registration rate, rotationerror, translation error, and outperformed the state-of-the-art approaches.
Modeling by constraints enables users to describe shapes by specifying relationships between geometric elements. These relationships are called constraints. A constraint solver derives then automatically the design in...
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Modeling by constraints enables users to describe shapes by specifying relationships between geometric elements. These relationships are called constraints. A constraint solver derives then automatically the design intended by exploiting these constraints. The constraints solvers can be classified in four categories: symbolic, numerical, rule-oriented and graph-constructive solvers. The graph constructive approach is widely used in recent Computer Aided Design (CAD) systems. in this paper, we present a decomposition-recombination (DR) planning algorithm, called S-DR, that uses a graph reduction method to solve systems of 2D geometric constraints. Based on the key concept of skeletons, S-DR planner figures out a plan for decomposing a well constrained system into small sub-systems and recombines the solutions of these sub-systems to derive the solution of the entire system. (C) 2010 Elsevier Ltd. All rights reserved.
A new heuristic algorithm, PROBE_BA, which is based on the recently introduced metaheuristic paradigm Population-Reinforced Optimization-Based Exploration (PROBE), is proposed for solving the graph Partitioning Proble...
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A new heuristic algorithm, PROBE_BA, which is based on the recently introduced metaheuristic paradigm Population-Reinforced Optimization-Based Exploration (PROBE), is proposed for solving the graph Partitioning Problem. The "exploration" part of PROBE_BA is implemented by using the Differential-Greedy algorithm of Battiti and Bertossi and a modification of the Kernighan-Lin algorithm at the heart of Bui and Moon's Genetic Algorithm BFS_GBA. Experiments are used to investigate properties of PROBE and show that PROBE_BA compares favorably with other solution methods based on Genetic algorithms, Randomized Reactive Tabu Search, or more specialized multilevel partitioning techniques. In addition, PROBE_BA finds new best cut values for 10 of the 34 instances in Walshaw's graph Partitioning Archive.
In this paper, we derive, by presenting some suitable notations, three typical graph algorithms and corresponding programs using a unified approach, partition-and-recur. We putemphasis on the derivation rather than th...
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In this paper, we derive, by presenting some suitable notations, three typical graph algorithms and corresponding programs using a unified approach, partition-and-recur. We putemphasis on the derivation rather than the algorithms themselves. The main ideas and lugesnutty of these algorithms are revealed by formula deduction. Success in these examples givesus more evidence that partition-and-recur is a simple and practical approach and developingenough suitable notations is the key in designing and deriving efficient and correct algorithmicprograms.
We serve a number of important and interesting problems from graph theory on a linear array with a reconfigurable pipelined optical bus system. Our algorithms are based on fast matrix multiplication and extreme value ...
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We serve a number of important and interesting problems from graph theory on a linear array with a reconfigurable pipelined optical bus system. Our algorithms are based on fast matrix multiplication and extreme value finding algorithms, and are currently the fastest algorithms. We also distinguish the two cases where weights have bounded/unbounded magnitude and precision. (C) 2000 Published by Elsevier Science B.V. All rights reserved.
The ability to transfer knowledge learned in one environment in order to improve performance in a different environment is one of the hallmarks of human intelligence. Insights into human transfer learning help us to d...
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The ability to transfer knowledge learned in one environment in order to improve performance in a different environment is one of the hallmarks of human intelligence. Insights into human transfer learning help us to design computer-based agents that can better adapt to new environments without the need for substantial reprogramming. In this paper, we study the transfer of knowledge by humans playing various scenarios in a graphically realistic urban setting that are specifically designed to test various levels of transfer. We determine the amount and type of transfer that is being performed based on the performance of trained and untrained human players. In addition, we use a graph-based relational learning algorithm to extract patterns from player graphs. These analyses reveal that indeed humans are transferring knowledge from one set of games to another and the amount and type of transfer varies according to player experience and scenario complexity. The results of this analysis help us understand the nature of human transfer in such environments and shed light on how we might endow computer-based agents with similar capabilities. The game simulator and human data collection also represent a significant testbed in which other AI capabilities can be tested and compared to human performance.
Luttamguzi et al. [(2005) Integer Programming Methods for Several Optimization Problems in graph Theory. Proc. Int. Conf. Computers and Their Applications, CATA 2005, New Orleans, LA, USA, March 16-18, pp. 50-55. ISCA...
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Luttamguzi et al. [(2005) Integer Programming Methods for Several Optimization Problems in graph Theory. Proc. Int. Conf. Computers and Their Applications, CATA 2005, New Orleans, LA, USA, March 16-18, pp. 50-55. ISCA] have introduced a useful framework for the formulation of graph layout parameters measuring number of edges, which is applied to give linear programming formulations for computing the cut-width, minimum linear arrangement and band-width of a graph. We extend the framework of Luttamguzi et al. by the efficient formulation of sets of vertices of the same neighborhood-so-called groups-using binary linear programming (BIP) conditions. We apply our methods in order to find first BIP formulations for computing the important graph layout para-me-ters path-width, neighborhood-width, linear NLC-width, and linear clique-width. Our formulations give useful and new characterizations of the problems as well as easy-to-understand algorithms for their solution. The size of our formulations is polynomial in the size of the input graph.
A cycle C passing through two specific vertices s and t of a biconnected graph is said to be an st-ambitus if its bridges do not interlace in some special way. We present algorithms for st-ambitus for planar biconnect...
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A cycle C passing through two specific vertices s and t of a biconnected graph is said to be an st-ambitus if its bridges do not interlace in some special way. We present algorithms for st-ambitus for planar biconnected graphs, which are much simpler than the one known for general graphs [MT]. Our algorithm runs in O(n) time on a sequential machine and (log n) parallel time using O(n/log n) processors on an EREW PRAM.
Let integers r >= 2 and d >= 3 be fixed. Let g(d) be the set of graphs with no induced path on d vertices. We study the problem of packing k vertex-disjoint copies of K-1,K-r, (k >= 2) into a graph G from par...
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Let integers r >= 2 and d >= 3 be fixed. Let g(d) be the set of graphs with no induced path on d vertices. We study the problem of packing k vertex-disjoint copies of K-1,K-r, (k >= 2) into a graph G from parameterized preprocessing, i.e., kernelization, point of view. We show that every graph G epsilon g(d) can be reduced, in polynomial time, to a graph G' epsilon g(d) with 0 (k) vertices such that G has at least k vertex-disjoint copies of K-1,K-r if and only if G' has. Such a result is known for arbitrary graphs G when r = 2 and we conjecture that it holds for every r >= 2. 2016 Elsevier B.V. All rights reserved.
In this paper we study how graph searching on a cocomparability graph G can be used to produce cocomp orderings (i.e., orderings that are linear extensions of some transitive orientation of G) that yield simple algori...
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In this paper we study how graph searching on a cocomparability graph G can be used to produce cocomp orderings (i.e., orderings that are linear extensions of some transitive orientation of G) that yield simple algorithms for various intractable problems in general. Such techniques have been used to find a simple certifying algorithm for the minimum path cover problem. In particular we present a characterization of the searches that preserve cocomp orderings when used as a "+" sweep. This allows us to present a toolbox of different graph searches and a framework to solve various problems on cocomparability graphs. We illustrate these techniques by describing a very simple certifying algorithm for the maximum independent set problem as well as a simple permutation graph recognition algorithm.
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