accedaCRIShttps://accedacris.ulpgc.es/jspuiThe accedaCRIS digital repository system captures, stores, indexes, preserves, and distributes digital research material.Wed, 08 Feb 2023 04:51:05 GMT2023-02-08T04:51:05Z5091- The meccano method for automatic volume parametrization of solidshttp://hdl.handle.net/10553/45231Title: The meccano method for automatic volume parametrization of solids
Authors: Montenegro, R.; Cascón, J. M.; Escobar, J. M.; Rodríguez, E.; Montero, G.
Abstract: In this paper, we present significant advances of the novel meccano technique for simultaneously constructing adaptive tetrahedral meshes of 3-D complex solids and their volume parametrization. Specifically, we will consider a solid whose boundary is a surface of genus zero. In this particular case, the automatic procedure is defined by a surface triangulation of the solid, a simple meccano composed by one cube and a tolerance that fixes the desired approximation of the solid surface. The main idea is based on an automatic mapping from the cube faces to the solid surface, a 3-D local refinement algorithm and a simultaneous mesh untangling and smoothing procedure. Although the initial surface triangulation can be a poor quality mesh, the meccano technique constructs high quality surface and volume adaptive meshes. Several examples show the efficiency of the proposed technique. Future possibilities of the meccano method for meshing a complex solid, whose boundary is a surface of genus greater than zero, are commented.
Fri, 01 Jan 2010 00:00:00 GMThttp://hdl.handle.net/10553/452312010-01-01T00:00:00Z
- Convergence speed of generalized longest-edge-based refinementhttp://hdl.handle.net/10553/54676Title: Convergence speed of generalized longest-edge-based refinement
Authors: Suárez, José P.; Moreno, Tania; Abad, Pilar; Plaza, Ángel
Abstract: In the refinement of meshes, one wishes to iteratively subdivide a domain following geometrical partition rules. The aim is to obtain a new discretized domain with adapted regions. We prove that the Longest Edge n -section of triangles for n⩾4 produces a finite sequence of triangle meshes with guaranteed convergence of diameters and review previous result when n equals 2 and 3. We give upper and lower bounds for the convergence speed in terms of diameter reduction. Then we fill the gap in the analysis of the diameters convergence for generalized Longest Edge based refinement. In addition, we give a numerical study for the case of n=4 , the so-called LE quatersection, evidencing its utility in adaptive mesh refinement.
Tue, 01 Jan 2013 00:00:00 GMThttp://hdl.handle.net/10553/546762013-01-01T00:00:00Z
- Duality in complex stochastic boolean systemshttp://hdl.handle.net/10553/16393Title: Duality in complex stochastic boolean systems
Authors: González Sánchez, Luis
Abstract: Many different complex systems depend on a large number n of mutually independent random Boolean variables. The most useful representation for these systems –usually called complex stochastic Boolean systems (CSBSs)– is the intrinsic order graph. This is a directed graph on 2n vertices, corresponding to the 2n binary n-tuples (u1, . . . , un) _ {0, 1} n of 0s and 1s. In this paper, different duality properties of the intrinsic order graph are rigorously analyzed in detail. The results can be applied to many CSBSs arising from any scientific, technical or social area…
Sun, 01 Jan 2012 00:00:00 GMThttp://hdl.handle.net/10553/163932012-01-01T00:00:00Z
- Labeling the nodes in the intrinsic order graph with their weightshttp://hdl.handle.net/10553/16412Title: Labeling the nodes in the intrinsic order graph with their weights
Authors: González, Luis
Abstract: This paper deals with the study of some new properties of the intrinsic order graph. The intrinsic order graph is the natural graphical representation of a complex stochastic Boolean system (CSBS). A CSBS is a system depending on an arbitrarily large number n of mutually independent random Boolean variables. The intrinsic order graph displays its 2n vertices (associated to the CSBS) from top to bottom, in decreasing order of their occurrence probabilities. New relations between the intrinsic ordering and the Hamming weight (i.e., the number of 1-bits in a binary n-tuple) are derived. Further, the distribution of the weights of the 2n nodes in the intrinsic order graph is analyzed…
Tue, 01 Jan 2013 00:00:00 GMThttp://hdl.handle.net/10553/164122013-01-01T00:00:00Z
- Ranking intervals in complex stochastic Boolean systems using intrinsic orderinghttp://hdl.handle.net/10553/44518Title: Ranking intervals in complex stochastic Boolean systems using intrinsic ordering
Authors: González, Luis
Abstract: Many different phenomena, arising from scientific, technical or social areas, can be modeled by a system depending on a certain number n of random Boolean variables. The so-called complex stochastic Boolean systems (CSBSs) are characterized by the ordering between the occurrence probabilities Pr{u} of the 2 n associated binary strings of length n, i.e., u=(u 1,…,u n ) ∈ {0,1} n . The intrinsic order defined on {0,1} n provides us with a simple positional criterion for ordering the binary n-tuple probabilities without computing them, simply looking at the relative positions of their 0s and 1s. For every given binary n-tuple u, this paper presents two simple formulas – based on the positions of the 1-bits (0-bits, respectively) in u – for counting (and also for rapidly generating, if desired) all the binary n-tuples v whose occurrence probabilities Pr{v} are always less than or equal to (greater than or equal to, respectively) Pr{u}. Then, from these formulas, we determine the closed interval covering all possible values of the rank (position) of u in the list of all binary n-tuples arranged by decreasing order of their occurrence probabilities. Further, the length of this so-called ranking interval for u, also provides the number of binary n-tuples v incomparable by intrinsic order with u. Results are illustrated with the intrinsic order graph, i.e., the Hasse diagram of the partial intrinsic order.
Fri, 01 Jan 2010 00:00:00 GMThttp://hdl.handle.net/10553/445182010-01-01T00:00:00Z
- Prefacehttp://hdl.handle.net/10553/117419Title: Preface
Authors: Sanyal, Goutam; Travieso-González, Carlos M.; Awasthi, Shashank; Pinto, Carla M.A.; Purushothama, B. R.
Sat, 01 Jan 2022 00:00:00 GMThttp://hdl.handle.net/10553/1174192022-01-01T00:00:00Z
- Prefacehttp://hdl.handle.net/10553/117420Title: Preface
Authors: Sanyal, Goutam; Travieso-González, Carlos M.; Awasthi, Shashank; Pinto, Carla M.A.; Purushothama, B. R.
Sat, 01 Jan 2022 00:00:00 GMThttp://hdl.handle.net/10553/1174202022-01-01T00:00:00Z
- Sleep quality differences according to a statistical continuous sleep modelhttp://hdl.handle.net/10553/52455Title: Sleep quality differences according to a statistical continuous sleep model
Authors: Ravelo-García, A. G.; Lorenzo-García, F. D.; Navarro-Mesa, J. L.
Abstract: This paper presents sleep quality differences between good and bad sleepers measured with a statistical continuous sleep model according to the Self-Rating Questionnaire for Sleep and Awakening Quality (SSA). Our main goal is to describe sleep continuous traces that take into account the sleep stage probability with a temporal resolution of 3 s, instead of the Rechtschaffen and Kales (R and K) resolution, which is 30 s. We adopt in our study the probability of being in stages W, S1, S2, S3, S4, and REM. The system uses only one electroencephalographic (EEG) channel. In order to achieve this goal we start by applying a hidden Markov model, in which the hidden states are associated with the sleep stages. These are probabilistic models that constitute the basis for the estimation of the sleep stage probabilities. The features that feed our model are based on the application of a discrete cosine transform to a vector of logarithmic energies at the output of a set of linearly spaced filters. In order to find differences between groups of sleepers, we define some measures based on the probabilistic traces. The experiments are performed over 24 recordings from the SIESTA database. The results show that our system performs well in finding differences in the presence of the Wake and S4 sleep stages for each group. © 2009 Springer Science+Business Media, LLC.
Thu, 01 Jan 2009 00:00:00 GMThttp://hdl.handle.net/10553/524552009-01-01T00:00:00Z
- Handwriting knowledge based on parameterization for writer identificationhttp://hdl.handle.net/10553/44073Title: Handwriting knowledge based on parameterization for writer identification
Authors: Romero, Carlos F.; Travieso, Carlos M.; Ferrer, Miguel A.; Alonso, Jesús B.
Abstract: This present paper has worked out and implemented a set of geometrical characteristics from observation of handwriting. In particular, this work has developed a proportionality index together with other parameters applied to handwritten words, and they have been used for writer identification. That set of characteristics has been tested with our offline handwriting database, which consists of 40 writers with 10 samples per writer. We have got a success rate of 97%, applying a neural network as classifier.
Thu, 01 Jan 2009 00:00:00 GMThttp://hdl.handle.net/10553/440732009-01-01T00:00:00Z