Departament de Matemàtiques
http://hdl.handle.net/2117/3917
2017-05-23T12:52:01ZInfluence of admission marks on the academic performance of technical architecture students
http://hdl.handle.net/2117/104739
Influence of admission marks on the academic performance of technical architecture students
Gaspar Fàbregas, Kàtia; Núñez Andrés, María Amparo; Rodríguez Jordana, Juan; Jordana Riba, Francisco de Paula
Traditionally, students from higher training cycle and upper secondary school education access higher technical education
with a wide range of access marks in each group. The purpose of this article is to analyse how students’ backgrounds and
access marks really influence their success in the first academic year and further evolution to obtain the degree of Technical
Architecture.
To achieve this aim, the progress of students from different backgrounds was analysed for three academic years from
2002/2003 to 2004/2005 prior to the implementation of a curriculum adapted to the European Higher Education Area
(EHEA), so that the curriculum change does not introduce noise in the data. That involves 983 students in this study.
Moreover, most students in the new curriculum have not completed all the courses.
It was found that, once students had completed the first semester, a selection stage in the studies that were analysed, their
background did not influence their performance. However, it was also found that the access mark influenced both the mark
for the selection stage and academic performance until completion of the degree.
2017-05-23T08:51:38ZGaspar Fàbregas, KàtiaNúñez Andrés, María AmparoRodríguez Jordana, JuanJordana Riba, Francisco de PaulaTraditionally, students from higher training cycle and upper secondary school education access higher technical education
with a wide range of access marks in each group. The purpose of this article is to analyse how students’ backgrounds and
access marks really influence their success in the first academic year and further evolution to obtain the degree of Technical
Architecture.
To achieve this aim, the progress of students from different backgrounds was analysed for three academic years from
2002/2003 to 2004/2005 prior to the implementation of a curriculum adapted to the European Higher Education Area
(EHEA), so that the curriculum change does not introduce noise in the data. That involves 983 students in this study.
Moreover, most students in the new curriculum have not completed all the courses.
It was found that, once students had completed the first semester, a selection stage in the studies that were analysed, their
background did not influence their performance. However, it was also found that the access mark influenced both the mark
for the selection stage and academic performance until completion of the degree.A Classroom activity to work with real data and diverse strategies in order to build models with the help of the computer
http://hdl.handle.net/2117/104633
A Classroom activity to work with real data and diverse strategies in order to build models with the help of the computer
Ginovart Gisbert, Marta
Dealing with pseudo-mechanistic models, which are continuous and
empirical models where the parameters involved have a meaning according to the context where they are applied, has an added value. The aim of this study was to design a set of tasks to be performed with the help of the computer and implement them in the classroom in order to investigate a real data set with empirical models
and pseudo-mechanistic models. A framework showing different strategies to tackle these data, and how they generate a variety of plausible responses to the problem, was configured. The sequence and structure of these tasks jointly with the help of appropriate computer resources, according to the students ’perceptions, enhanced the understanding of the construction and use of these models
2017-05-19T08:04:24ZGinovart Gisbert, MartaDealing with pseudo-mechanistic models, which are continuous and
empirical models where the parameters involved have a meaning according to the context where they are applied, has an added value. The aim of this study was to design a set of tasks to be performed with the help of the computer and implement them in the classroom in order to investigate a real data set with empirical models
and pseudo-mechanistic models. A framework showing different strategies to tackle these data, and how they generate a variety of plausible responses to the problem, was configured. The sequence and structure of these tasks jointly with the help of appropriate computer resources, according to the students ’perceptions, enhanced the understanding of the construction and use of these modelsA new labeling construction from the -product
http://hdl.handle.net/2117/104632
A new labeling construction from the -product
López Masip, Susana Clara; Muntaner Batle, Francesc Antoni; Prabu, M.
The ¿h-product that is referred in the title was introduced in 2008 as a generalization of the Kronecker product of digraphs. Many relations among labelings have been obtained since then, always using as a second factor a family of super edge-magic graphs with equal order and size. In this paper, we introduce a new labeling construction by changing the role of the factors. Using this new construction the range of applications grows up considerably. In particular, we can increase the information about magic sums of cycles and crowns.
2017-05-19T07:50:07ZLópez Masip, Susana ClaraMuntaner Batle, Francesc AntoniPrabu, M.The ¿h-product that is referred in the title was introduced in 2008 as a generalization of the Kronecker product of digraphs. Many relations among labelings have been obtained since then, always using as a second factor a family of super edge-magic graphs with equal order and size. In this paper, we introduce a new labeling construction by changing the role of the factors. Using this new construction the range of applications grows up considerably. In particular, we can increase the information about magic sums of cycles and crowns.Using the multilinear extension to study some probabilistic power indices
http://hdl.handle.net/2117/104580
Using the multilinear extension to study some probabilistic power indices
Freixas Bosch, Josep; Pons Vallès, Montserrat
We consider binary voting systems modeled by a simple game, in which voters vote independently of each other, and the probability distribution over coalitions is known. The Owen’s multilinear extension of the simple game is used to improve the use and the computation of three indices defined in this model: the decisiveness index, which is an extension of the Banzhaf index, the success index, which is an extension of the Rae index, and the luckiness index. This approach leads us to prove new properties and inter-relations between these indices. In particular it is proved that the ordinal equivalence between success and decisiveness indices is achieved in any game if and only if the probability distribution is anonymous. In the anonymous case, the egalitarianism of the three indices is compared, and it is also proved that, for these distributions, decisiveness and success indices respect the strength of the seats, whereas luckiness reverses this order.
The final publication is available at Springer via http://dx.doi.org/10.1007/s10726-016-9514-6
2017-05-17T14:32:45ZFreixas Bosch, JosepPons Vallès, MontserratWe consider binary voting systems modeled by a simple game, in which voters vote independently of each other, and the probability distribution over coalitions is known. The Owen’s multilinear extension of the simple game is used to improve the use and the computation of three indices defined in this model: the decisiveness index, which is an extension of the Banzhaf index, the success index, which is an extension of the Rae index, and the luckiness index. This approach leads us to prove new properties and inter-relations between these indices. In particular it is proved that the ordinal equivalence between success and decisiveness indices is achieved in any game if and only if the probability distribution is anonymous. In the anonymous case, the egalitarianism of the three indices is compared, and it is also proved that, for these distributions, decisiveness and success indices respect the strength of the seats, whereas luckiness reverses this order.Arnold diffusion for a complete family of perturbations
http://hdl.handle.net/2117/104532
Arnold diffusion for a complete family of perturbations
Delshams Valdés, Amadeu; Gonçalves Schaefer, Rodrigo
In this work we illustrate the Arnold diffusion in a concrete example — the a priori unstable Hamiltonian system of 2 + 1/2 degrees of freedom H(p, q, I, f, s) = p2/2+ cos q - 1 + I2/2 + h(q, f, s; e) — proving that for any small periodic perturbation of the form h(q, f, s; e) = e cos q (a00 + a10 cosf + a01 cos s) (a10a01 ¿ 0) there is global instability for the action. For the proof we apply a geometrical mechanism based on the so-called scattering map. This work has the following structure: In the first stage, for a more restricted case (I* ~ p/2µ, µ = a10/a01), we use only one scattering map, with a special property: the existence of simple paths of diffusion called highways. Later, in the general case we combine a scattering map with the inner map (inner dynamics) to prove the more general result (the existence of instability for any µ). The bifurcations of the scattering map are also studied as a function of µ. Finally, we give an estimate for the time of diffusion, and we show that this time is primarily the time spent under the scattering map.
2017-05-17T07:57:57ZDelshams Valdés, AmadeuGonçalves Schaefer, RodrigoIn this work we illustrate the Arnold diffusion in a concrete example — the a priori unstable Hamiltonian system of 2 + 1/2 degrees of freedom H(p, q, I, f, s) = p2/2+ cos q - 1 + I2/2 + h(q, f, s; e) — proving that for any small periodic perturbation of the form h(q, f, s; e) = e cos q (a00 + a10 cosf + a01 cos s) (a10a01 ¿ 0) there is global instability for the action. For the proof we apply a geometrical mechanism based on the so-called scattering map. This work has the following structure: In the first stage, for a more restricted case (I* ~ p/2µ, µ = a10/a01), we use only one scattering map, with a special property: the existence of simple paths of diffusion called highways. Later, in the general case we combine a scattering map with the inner map (inner dynamics) to prove the more general result (the existence of instability for any µ). The bifurcations of the scattering map are also studied as a function of µ. Finally, we give an estimate for the time of diffusion, and we show that this time is primarily the time spent under the scattering map.A well-posed problem for the three-dual-phase-lag heat conduction
http://hdl.handle.net/2117/104492
A well-posed problem for the three-dual-phase-lag heat conduction
Quintanilla de Latorre, Ramón
2017-05-16T10:32:21ZQuintanilla de Latorre, RamónReal time global ionospheric maps: a low latency alternative to traditional GIMs
http://hdl.handle.net/2117/104472
Real time global ionospheric maps: a low latency alternative to traditional GIMs
Roma Dollase, David; Hernández Pajares, Manuel; García Rigo, Alberto; Laurichesse, Denis; Schmidt, Michael; Erdogan, Eren; Yuan, Yunbin; Li, Zishen; Gómez-Cama, José Ma.; Krankowski, Andrzej
Since the late nineties different entities have been generating and distributing Global Ionospheric Maps (GIMs). In this time, multiple new application have arisen from the determination of electron content distribution and time evolution at global scale: from the more direct correction used by GNSS users up to measurement of solar EUV flux rate during solar flares, at global scale (Singh et al 2015). Moreover specific applications requiring precise real-time positioning and potential detection of tsunamis at regional and continental scales (Galvan et al 2011) are also active fields of work. However, the latency to access the GNSS data and the computational time was too high to make real time GIMs. Nowadays thanks to the internet, which allows having real time access to permanent GNSS receiver’s raw data, the maturity of
the ionospheric modelling techniques and the computational power of modern computers we are able to compute different real-time ionospheric products. In this poster we compare six different products: three real-time from CAS (aoeg), CNES (cnsg) and UPC (urtg); one near real time from TUM (dgfi) and two traditional GIMs for reference, from UPC (uqrg) and IGS (igs).
2017-05-16T08:11:54ZRoma Dollase, DavidHernández Pajares, ManuelGarcía Rigo, AlbertoLaurichesse, DenisSchmidt, MichaelErdogan, ErenYuan, YunbinLi, ZishenGómez-Cama, José Ma.Krankowski, AndrzejSince the late nineties different entities have been generating and distributing Global Ionospheric Maps (GIMs). In this time, multiple new application have arisen from the determination of electron content distribution and time evolution at global scale: from the more direct correction used by GNSS users up to measurement of solar EUV flux rate during solar flares, at global scale (Singh et al 2015). Moreover specific applications requiring precise real-time positioning and potential detection of tsunamis at regional and continental scales (Galvan et al 2011) are also active fields of work. However, the latency to access the GNSS data and the computational time was too high to make real time GIMs. Nowadays thanks to the internet, which allows having real time access to permanent GNSS receiver’s raw data, the maturity of
the ionospheric modelling techniques and the computational power of modern computers we are able to compute different real-time ionospheric products. In this poster we compare six different products: three real-time from CAS (aoeg), CNES (cnsg) and UPC (urtg); one near real time from TUM (dgfi) and two traditional GIMs for reference, from UPC (uqrg) and IGS (igs).Locating-dominating partitions in graphs
http://hdl.handle.net/2117/104422
Locating-dominating partitions in graphs
Pelayo Melero, Ignacio Manuel; Hernando Martín, María del Carmen; Mora Giné, Mercè
Let G = (V, E) be a connected graph of order n. Let ¿ = {S1, . . . , Sk} be
a partition of V . Let r(u|¿) denote the vector of distances between a vertex
v ¿ V and the elements of ¿, that is, r(v, ¿) = (d(v, S1), . . . , d(v, Sk)). The
partition ¿ is called a locating partition of G if, for every pair of distinct
vertices u, v ¿ V , r(u, ¿) 6= r(v, ¿). A locating partition ¿ is called metriclocating-dominating partition (an MLD-partition for short) of G if it is also dominating,
2017-05-15T12:02:03ZPelayo Melero, Ignacio ManuelHernando Martín, María del CarmenMora Giné, MercèLet G = (V, E) be a connected graph of order n. Let ¿ = {S1, . . . , Sk} be
a partition of V . Let r(u|¿) denote the vector of distances between a vertex
v ¿ V and the elements of ¿, that is, r(v, ¿) = (d(v, S1), . . . , d(v, Sk)). The
partition ¿ is called a locating partition of G if, for every pair of distinct
vertices u, v ¿ V , r(u, ¿) 6= r(v, ¿). A locating partition ¿ is called metriclocating-dominating partition (an MLD-partition for short) of G if it is also dominating,On the spectra of Markov matrices for weighted Sierpinski graphs
http://hdl.handle.net/2117/104412
On the spectra of Markov matrices for weighted Sierpinski graphs
Comellas Padró, Francesc de Paula; Xie, Pinchen; Zhang, Zhongzhi
Relevant information from networked systems can be obtained by analyzing the spectra of matrices associated to their graph representations. In particular, the eigenvalues and eigenvectors of the Markov matrix and related Laplacian and normalized Laplacian matrices allow the study of structural and dynamical aspects of a network, like its synchronizability and random walks properties. In this study we obtain, in a recursive way, the spectra of Markov matrices of a family of rotationally invariant weighted Sierpinski graphs. From them we find analytic expressions for the weighted count of spanning trees and the random target access time for random walks on this family of weighted graphs.
2017-05-15T10:27:27ZComellas Padró, Francesc de PaulaXie, PinchenZhang, ZhongzhiRelevant information from networked systems can be obtained by analyzing the spectra of matrices associated to their graph representations. In particular, the eigenvalues and eigenvectors of the Markov matrix and related Laplacian and normalized Laplacian matrices allow the study of structural and dynamical aspects of a network, like its synchronizability and random walks properties. In this study we obtain, in a recursive way, the spectra of Markov matrices of a family of rotationally invariant weighted Sierpinski graphs. From them we find analytic expressions for the weighted count of spanning trees and the random target access time for random walks on this family of weighted graphs.A lower bound for the size of a Minkowski sum of dilates
http://hdl.handle.net/2117/104404
A lower bound for the size of a Minkowski sum of dilates
Hamidoune, Yayha Old; Rué Perna, Juan José
Let A be a finite non-empty set of integers. An asymptotic estimate of the size of the sum of several dilates was obtained by Bukh. The unique known exact bound concerns the sum |A + k·A|, where k is a prime and |A| is large. In its full generality, this bound is due to Cilleruelo, Serra and the first author.
Let k be an odd prime and assume that |A| > 8kk. A corollary to our main result states that |2·A + k·A|=(k+2)|A|-k2-k+2. Notice that |2·P+k·P|=(k+2)|P|-2k, if P is an arithmetic progression.
2017-05-15T09:11:57ZHamidoune, Yayha OldRué Perna, Juan JoséLet A be a finite non-empty set of integers. An asymptotic estimate of the size of the sum of several dilates was obtained by Bukh. The unique known exact bound concerns the sum |A + k·A|, where k is a prime and |A| is large. In its full generality, this bound is due to Cilleruelo, Serra and the first author.
Let k be an odd prime and assume that |A| > 8kk. A corollary to our main result states that |2·A + k·A|=(k+2)|A|-k2-k+2. Notice that |2·P+k·P|=(k+2)|P|-2k, if P is an arithmetic progression.