Browsing by Author "Silveira, Rodrigo Ignacio"
Now showing items 1-20 of 76
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A comparative analysis of trajectory similarity measures
(2021-06-23)
Article
Open AccessComputing trajectory similarity is a fundamental operation in movement analytics, required in search, clustering, and classification of trajectories, for example. Yet the range of different but interrelated trajectory ... -
A faster algorithm to compute the visibility map of a 1.5D terrain
(2014)
Conference report
Open AccessGiven a 1.5D terrain, i.e., an x -monotone polygonal line in R 2 with n vertices, and 1 m n viewpoints placed on some of the terrain vertices, we study the problem of computing the parts of the terrain that are visible ... -
A new lower bound on the maximum number of plane graphs using production matrices
(2018)
Conference lecture
Restricted access - publisher's policyWe use the concept of production matrices to show that there exist sets of n points in the plane that admit ¿(41.77n) crossing-free geometric graphs. This improves the previously best known bound of ¿(41.18n) by Aichholzer ... -
A new lower bound on the maximum number of plane graphs using production matrices
(2019-11-01)
Article
Open AccessWe use the concept of production matrices to show that there exist sets of n points in the plane that admit ¿(42.11n ) crossing-free geometric graphs. This improves the previously best known bound of ¿(41.18n ) by Aichholzer ... -
A new meta-module design for efficient reconfiguration of modular robots
(Springer Nature, 2021-05-01)
Article
Open AccessWe propose a new meta-module design for two important classes of modular robots. The new metamodule is three-dimensional, robust and compact, improving on the previously proposed one. It applies to socalled “edge-hinged” ... -
A new meta-module for efficient reconfiguration of hinged-units modular robots
(Institute of Electrical and Electronics Engineers (IEEE), 2016)
Conference report
Open AccessWe present a robust and compact meta-module for edge-hinged modular robot units such as M-TRAN, SuperBot, SMORES, UBot, PolyBot and CKBot, as well as for central-point-hinged ones such as Molecubes and Roombots. Thanks ... -
A note on flips in diagonal rectangulations
(Chapman & Hall/CRC, 2018-11-09)
Article
Open AccessRectangulations are partitions of a square into axis-aligned rectangles. A number of results provide bijections between combinatorial equivalence classes of rectangulations and families of pattern-avoiding permutations. ... -
A scalable method to construct compact road networks from GPS trajectories
(2021)
Article
Open AccessThe automatic generation of road networks from GPS tracks is a challenging problem that has been receiving considerable attention in the last years. Although dozens of methods have been proposed, current techniques suffer ... -
Adjacency-preserving spatial treemaps
(2016)
Article
Open AccessRectangular layouts, subdivisions of an outer rectangle into smaller rectangles, have many applications in visualizing spatial information, for instance in rectangular cartograms in which the rectangles represent geographic ... -
Affine invariant triangulations
(2019)
Conference report
Restricted access - publisher's policyWe study affine invariant 2D triangulation methods. That is, methods that produce the same triangulation for a point set S for any (unknown) affine transformation of S. Our work is based on a method by Nielson [A ... -
Affine invariant triangulations
(2021-11-01)
Article
Open AccessWe study affine invariant 2D triangulation methods. That is, methods that produce the same triangulation for a point set S for any (unknown) affine transformation of S. Our work is based on a method by Nielson (1993) that ... -
Balanced partitions of 3-colored geometric sets in the plane
(2015)
Article
Open AccessLet SS be a finite set of geometric objects partitioned into classes or colors . A subset S'¿SS'¿S is said to be balanced if S'S' contains the same amount of elements of SS from each of the colors. We study several ... -
Cell-paths in mono- and bichromatic line arrangements in the plane
(2014)
Conference report
Open AccessWe show that in every arrangement of n red and blue lines | in general position and not all of the same color | there is a path through a linear number of cells where red and blue lines are crossed alternatingly (and no ... -
Characteristic polynomials of production matrices for geometric graphs
(2017-08-01)
Article
Open AccessAn n×n production matrix for a class of geometric graphs has the property that the numbers of these geometric graphs on up to n vertices can be read off from the powers of the matrix. Recently, we obtained such production ... -
Colored Ray configurations
(2014)
Conference report
Open AccessWe study the cyclic sequences induced at in nity by pairwise-disjoint colored rays with apices on a given bal- anced bichromatic point set, where the color of a ray is inherited from the color of its apex. We derive a lower ... -
Colored ray configurations
(2018-05)
Article
Open AccessWe study the cyclic color sequences induced at infinity by colored rays with apices being a given balanced finite bichromatic point set. We first study the case in which the rays are required to be pairwise disjoint. We ... -
Colored spanning graphs for set visualization
(2018-03)
Article
Open AccessWe study an algorithmic problem that is motivated by ink minimization for sparse set visualizations. Our input is a set of points in the plane which are either blue, red, or purple. Blue points belong exclusively to the ... -
Colored spanning graphs for set visualization
(Springer, 2013)
Conference report
Open AccessWe study an algorithmic problem that is motivated by ink minimization for sparse set visualizations. Our input is a set of points in the plane which are either blue, red, or purple. Blue points belong exclusively to the ... -
Computing a visibility polygon using few variables
(2014-10-01)
Article
Restricted access - publisher's policyWe present several algorithms for computing the visibility polygon of a simple polygon P of n vertices (out of which r are reflex) from a viewpoint inside P, when P resides in read-only memory and only few working variables ... -
Computing correlation between piecewise-linear functions
(2013)
Article
Restricted access - publisher's policyWe study the problem of computing correlation between two piecewise-linear bivariate functions defined over a common domain, where the surfaces they define in three dimensions---polyhedral terrains---can be transformed ...
