Antoni Pérez-navarro - Academia.edu (original) (raw)
Papers by Antoni Pérez-navarro
Multimedia Tools and Applications, Sep 5, 2020
Perez-Navarro, A., Conesa, J. Students perception of videos in introductory physics courses of en... more Perez-Navarro, A., Conesa, J. Students perception of videos in introductory physics courses of engineering in face-to-face and online environments. Multimed Tools Appl (2020).
IEEE Access, 2020
IPIN 2019 Competition, sixth in a series of IPIN competitions, was held at the CNR Research Area ... more IPIN 2019 Competition, sixth in a series of IPIN competitions, was held at the CNR Research Area of Pisa (IT), integrated into the program of the IPIN 2019 Conference. It included two on-site real-time Tracks and three off-site Tracks. The four Tracks presented in this paper were set in the same environment, made of two buildings close together for a total usable area of 1000 m 2 outdoors and and 6000 m 2 indoors over three floors, with a total path length exceeding 500 m. IPIN competitions, based on the EvAAL framework, have aimed at comparing the accuracy performance of personal positioning systems in fair and realistic conditions: past editions of the competition were carried in big conference settings, university campuses and a shopping mall. Positioning accuracy is computed while the person carrying the system under test walks at normal walking speed, uses lifts and goes up and down stairs or briefly stops at given points. Results presented here are a showcase of state-of-the-art systems tested side by side in real-world settings as part of the on-site real-time competition Tracks. Results for off-site Tracks allow a detailed and reproducible comparison of the most recent positioning and tracking algorithms in the same environment as the on-site Tracks.
Prevention of sexually transmitted infections using mobile devices and ubiquitous computing
International Journal of Technology Assessment in Health Care, 2019
IntroductioneHealth is a new approach for managing several health conditions, but up to now not s... more IntroductioneHealth is a new approach for managing several health conditions, but up to now not so many interventions have shown their efficacy/effectiveness. The AUTAPP Project tries to add knowledge in eHealth interventions targeted to Mental Health disorders, specifically Autism Spectrum Disorder (ASD) management that requires complex interventions that integrate different psychosocial interventions. AUTAPP aims to develop an evidence based Clinical Decision Support System (CDSS) using mobile technology for improving the decision process on psychosocial therapies in ASD. This study aimed to identify recommendations on which the algorithm of the CDSS will be developed.MethodsA systematic review (November 2009-November 2018) was carried out to identify the existing scientific evidence published in relation to the effectiveness of: (i) early detection protocols; (ii) assessment tools; (iii) existing non-pharmacological therapies. Main databases were consulted (PubMed, Cochrane Libra...
EDULEARN16 Proceedings, 2016
Phys. Rev. B, 2000
The electronic structure of mathrmSr2mathrmRuO4{\mathrm{Sr}}_{2}{\mathrm{RuO}}_{4}mathrmSr2mathrmRuO4 according to experimental spect... more The electronic structure of mathrmSr2mathrmRuO4{\mathrm{Sr}}_{2}{\mathrm{RuO}}_{4}mathrmSr2mathrmRuO4 according to experimental spectroscopic data presents strong correlation in the electrons at energies close to EF.{E}_{F}.EF. We investigate this point by analyzing the electronic structure calculated from several complementary procedures. The first of these is performed by means of the local density approximation (LDA). In a second calculation we develop an mathrmLDA+U\mathrm{LDA}+UmathrmLDA+U calculation and finally, we include the self-energy effects obtained from a multiband Hubbard model. Our results for the first calculation are similar to those previously performed within the LDA, and these results are used for obtaining the self-energy effects included in the second calculation. The inclusion of these effects yields an electronic structure that seems to be in reasonable agreement with spectroscopic experimental data.
Physica B: Condensed Matter, 2000
With regard the Hubbard Hamiltonian, we use a Bogolyubov transformation and within a spin density... more With regard the Hubbard Hamiltonian, we use a Bogolyubov transformation and within a spin density wave mean "eld, where the antiferromagnetic correlations of wave vector Q"(/a, /a) are included. This gives a new energy spectrum that is calculated starting from the band structure of La CuO determined in the local density formalism. We calculate the self-energy in this new ground state using the random phase approximation and a double Lorentzian as a non-interacting density of states. With this self-energy, Dyson's equation is solved by diagonalizing the Green's function in k-space. The density of states is obtained by considering the renormalization factor and the lifetimes of the quasiparticle states in each pole. This leads to the splitting of the input density of states that is calculated in the local density formalism.
Proceedings of the 2012 4th International Conference on Intelligent Networking and Collaborative Systems, INCoS 2012, 2012
With the advent of GPS and the spread of smart phones (iPhone, Android, etc.) have proliferated a... more With the advent of GPS and the spread of smart phones (iPhone, Android, etc.) have proliferated applications dealing with geographic information. Many of these applications are beginning to provide semantic information through: 1) the classification of tourist attractions in categories (thesauri tourism categories Open Street Map, etc.), and 2) the representation of metadata (Linked Geo Data, Crossing, etc.). However, mobile devices do not still uses all this potential. This paper presents a comprehensive study on the main formalisms to include Semantic and Geographic Data within a mobile device, and how to get them work efficiently just in the mobile, without internet connection. The article presents several options to implement these technologies and, for every option shows the limitations of such implementation. Therefore provides a glimpse into the various options available to implement semantic geographic applications on mobile devices. To mark the goal, the study shows a case study where ontologies have been used to provide semantics to a travel assistant that runs on mobile devices. The goal is an application able to offer personalized touristic routes different for every single user, that take into account, for example, the user interests and time available, and all the processes must be run within the mobile device. The main contribution of the paper is to manage and combine semantic data and geographic information within a mobile device, and doing it without internet connection, and for an end-user application.
Proceedings of the 2012 4th International Conference on Intelligent Networking and Collaborative Systems, INCoS 2012, 2012
At the end of their technical studies, students have to present a final project in order to finis... more At the end of their technical studies, students have to present a final project in order to finish their degree. With this project, students prove that they have got all of the competences they should have acquired. Some competencies, such as the ability to communicate orally or the ability to argue may be evaluated during a face-to-face dissertation defense, but how to translate this evaluation scenario to a virtual environment is a challenge. This paper faces the problem of presenting dissertations in a virtual environment, to evaluate the aforementioned competences. The solution proposed, called Present@, is focused in teaching and technical dimensions, and is complemented with some materials and tutorials that help students to acquire those competences. Therefore, the paper shows Present@ as a solution to the problems that virtual universities have to face when dealing with the evaluation of final degree projects and particularly in their defense. Present@ has been tested over 131 students during six semesters and the results show that it actually helps students to acquire the desired competences in virtual environments. In addition, the analysis about the use of the tool has denoted that videos are an efficient mechanism to evaluate the ability to communicate of students and to work on transversal competencies. Some students also commented that the use of videos make the dissertation defense more natural and closer to face-to-face environments.
Physica B: Condensed Matter, 1999
The non-copper layered perovskite, Sr RuO , is expected to be a very useful reference material fo... more The non-copper layered perovskite, Sr RuO , is expected to be a very useful reference material for interpreting experiments on the high ¹ cuprate superconductors. A band structure calculation for Sr RuO is performed. Starting from the electronic structure determined in the local density formalism, the Dyson's equation with self-energies arising from the Hubbard hamiltonian is solved by diagonalizing the Green's function in k-space. The density of states is obtained by considering the renormalization factor and the lifetimes of the quasiparticle states in each pole of the interacting system. This leads to modification of the density of states calculated in the local density formalism, and the results fit experimental data not only in the position of peaks, but also in their intensity and in the number of states at Fermi level.
2012 Fourth International Conference on Intelligent Networking and Collaborative Systems, 2012
Several applications that support users when doing tourism have appeared during the last years. T... more Several applications that support users when doing tourism have appeared during the last years. These applications, though popular, have not become a reliable and dependable tourist assistant because they offer little personalization, which eventually may overwhelm users with too much information. An effective mobile application should store tourist information in a way that facilitates the identification of relevant points of interest to the user and the relevant information about them. The relevance of information depends also on the context. This paper presents an ontology that can store information about points of interest (POI), preferences and habits of users and time information. The presented ontology is aligned with the ontology Linked Geo Data to facilitate the importation of data to and from it. The ontology has been integrated into a mobile application called Itiner@ to create custom routes for each user based on his/her preferences, personal situation, means of transport, area to visit, date and duration of the visit. The main contribution of this work is to identify the relevant information to mobile touristic applications and to show how to use an ontology to improve the functionalities of geographic information system through the use of semantic information.
2009 EAEEIE Annual Conference, 2009
In the context of engineering studies, Virtual Laboratories (VL) are one of the most mentioned le... more In the context of engineering studies, Virtual Laboratories (VL) are one of the most mentioned learning tools. However, opinions on what different authors consider a virtual laboratory lead us to very disparate interpretations, with the consequent lack of consensus. In this work we focus on VL applied to e-learning in technical studies. The state-of-the-art concerning these laboratories is reviewed in
physica status solidi (b), 2000
We are interested in the description of the Mott-Hubbard transition from a perturbation theory ar... more We are interested in the description of the Mott-Hubbard transition from a perturbation theory arising from a two-dimensional Hubbard model. The self-energy within the random phase approximation presents some inconsistencies; one of them is that its imaginary part presents more than one zero, which is a violation of the Luttinger theorem. We use a Bogolyubov transformation and within a spin density wave mean field, we recalculate the self-energy in the new ground state, and it is able to describe the Mott-Hubbard transition, satisfying the Luttinger condition. 1999 Elsevier Science B.V. All rights reserved.
physica status solidi (b), 2002
In this paper we present a method for obtaining the quasiband structure and the renormalized dens... more In this paper we present a method for obtaining the quasiband structure and the renormalized density of quasistates of strongly correlated systems with antiferromagnetic ordering. We calculate the electronic structure of La 2 CuO 4 in order to test this method. The first step required is to calculate the electronic structure from the local density approximation (LDA) in order to obtain the initial non-interacting ground state. The LDA density of states in strongly correlated systems usually presents serious discrepancies with experimental results. As is well known, these discrepancies, fundamentally concerning photoemission, are due to the fact that the dynamic correlation effects are not taken into account within the LDA. In order to include these effects, we obtain a self-energy potential which allows the initial LDA electronic structure to connect with that of the antiferromagnetic ground state arising from a Bogolyubov-like transformation. Within this new ground state, we determine an antiferromagnetic self-energy by means of a spin density wave procedure, and the interacting Green function yields a density of states which is in reasonable agreement with the experimental photoemission result.
Physica B: Condensed Matter, 1997
... 1). Therefore, the new chosen fundamental state yields again a selfenergy which satisfies the... more ... 1). Therefore, the new chosen fundamental state yields again a selfenergy which satisfies the Luttinger theo rem with values of the band parameters closer to those for which superconductivity is found. (a) I@ 0.05 . ! i ' 0.00 .... . ...
Physica B: Condensed Matter, 2000
A quasiparticle structure calculation for Sr RuO is performed. Starting from the band structure d... more A quasiparticle structure calculation for Sr RuO is performed. Starting from the band structure determined in the local density formalism, the Dyson's equation with self-energies arising from the Hubbard Hamiltonian, is solved by diagonalizing the Green's function in k-space. The density of states is obtained by considering the renormalization factor and the lifetimes of the quasiparticle states. We also obtain the Fermi surface without and with the inclusion of the strong correlations e!ects.
Physica B: Condensed Matter, 1999
An approximated diagonalization of the Kondo lattice Hamiltonian is obtained considering an ansat... more An approximated diagonalization of the Kondo lattice Hamiltonian is obtained considering an ansatz based on strongly correlated many body states which are combinations of charged fermionic excitations coupled to a kind of spin wave. For determined values of the density of states of the non-interacting system and Kondo Hamiltonian parameter, there is an interval of the J parameter in which a new and interesting ground state appears.
Multimedia Tools and Applications, Sep 5, 2020
Perez-Navarro, A., Conesa, J. Students perception of videos in introductory physics courses of en... more Perez-Navarro, A., Conesa, J. Students perception of videos in introductory physics courses of engineering in face-to-face and online environments. Multimed Tools Appl (2020).
IEEE Access, 2020
IPIN 2019 Competition, sixth in a series of IPIN competitions, was held at the CNR Research Area ... more IPIN 2019 Competition, sixth in a series of IPIN competitions, was held at the CNR Research Area of Pisa (IT), integrated into the program of the IPIN 2019 Conference. It included two on-site real-time Tracks and three off-site Tracks. The four Tracks presented in this paper were set in the same environment, made of two buildings close together for a total usable area of 1000 m 2 outdoors and and 6000 m 2 indoors over three floors, with a total path length exceeding 500 m. IPIN competitions, based on the EvAAL framework, have aimed at comparing the accuracy performance of personal positioning systems in fair and realistic conditions: past editions of the competition were carried in big conference settings, university campuses and a shopping mall. Positioning accuracy is computed while the person carrying the system under test walks at normal walking speed, uses lifts and goes up and down stairs or briefly stops at given points. Results presented here are a showcase of state-of-the-art systems tested side by side in real-world settings as part of the on-site real-time competition Tracks. Results for off-site Tracks allow a detailed and reproducible comparison of the most recent positioning and tracking algorithms in the same environment as the on-site Tracks.
Prevention of sexually transmitted infections using mobile devices and ubiquitous computing
International Journal of Technology Assessment in Health Care, 2019
IntroductioneHealth is a new approach for managing several health conditions, but up to now not s... more IntroductioneHealth is a new approach for managing several health conditions, but up to now not so many interventions have shown their efficacy/effectiveness. The AUTAPP Project tries to add knowledge in eHealth interventions targeted to Mental Health disorders, specifically Autism Spectrum Disorder (ASD) management that requires complex interventions that integrate different psychosocial interventions. AUTAPP aims to develop an evidence based Clinical Decision Support System (CDSS) using mobile technology for improving the decision process on psychosocial therapies in ASD. This study aimed to identify recommendations on which the algorithm of the CDSS will be developed.MethodsA systematic review (November 2009-November 2018) was carried out to identify the existing scientific evidence published in relation to the effectiveness of: (i) early detection protocols; (ii) assessment tools; (iii) existing non-pharmacological therapies. Main databases were consulted (PubMed, Cochrane Libra...
EDULEARN16 Proceedings, 2016
Phys. Rev. B, 2000
The electronic structure of mathrmSr2mathrmRuO4{\mathrm{Sr}}_{2}{\mathrm{RuO}}_{4}mathrmSr2mathrmRuO4 according to experimental spect... more The electronic structure of mathrmSr2mathrmRuO4{\mathrm{Sr}}_{2}{\mathrm{RuO}}_{4}mathrmSr2mathrmRuO4 according to experimental spectroscopic data presents strong correlation in the electrons at energies close to EF.{E}_{F}.EF. We investigate this point by analyzing the electronic structure calculated from several complementary procedures. The first of these is performed by means of the local density approximation (LDA). In a second calculation we develop an mathrmLDA+U\mathrm{LDA}+UmathrmLDA+U calculation and finally, we include the self-energy effects obtained from a multiband Hubbard model. Our results for the first calculation are similar to those previously performed within the LDA, and these results are used for obtaining the self-energy effects included in the second calculation. The inclusion of these effects yields an electronic structure that seems to be in reasonable agreement with spectroscopic experimental data.
Physica B: Condensed Matter, 2000
With regard the Hubbard Hamiltonian, we use a Bogolyubov transformation and within a spin density... more With regard the Hubbard Hamiltonian, we use a Bogolyubov transformation and within a spin density wave mean "eld, where the antiferromagnetic correlations of wave vector Q"(/a, /a) are included. This gives a new energy spectrum that is calculated starting from the band structure of La CuO determined in the local density formalism. We calculate the self-energy in this new ground state using the random phase approximation and a double Lorentzian as a non-interacting density of states. With this self-energy, Dyson's equation is solved by diagonalizing the Green's function in k-space. The density of states is obtained by considering the renormalization factor and the lifetimes of the quasiparticle states in each pole. This leads to the splitting of the input density of states that is calculated in the local density formalism.
Proceedings of the 2012 4th International Conference on Intelligent Networking and Collaborative Systems, INCoS 2012, 2012
With the advent of GPS and the spread of smart phones (iPhone, Android, etc.) have proliferated a... more With the advent of GPS and the spread of smart phones (iPhone, Android, etc.) have proliferated applications dealing with geographic information. Many of these applications are beginning to provide semantic information through: 1) the classification of tourist attractions in categories (thesauri tourism categories Open Street Map, etc.), and 2) the representation of metadata (Linked Geo Data, Crossing, etc.). However, mobile devices do not still uses all this potential. This paper presents a comprehensive study on the main formalisms to include Semantic and Geographic Data within a mobile device, and how to get them work efficiently just in the mobile, without internet connection. The article presents several options to implement these technologies and, for every option shows the limitations of such implementation. Therefore provides a glimpse into the various options available to implement semantic geographic applications on mobile devices. To mark the goal, the study shows a case study where ontologies have been used to provide semantics to a travel assistant that runs on mobile devices. The goal is an application able to offer personalized touristic routes different for every single user, that take into account, for example, the user interests and time available, and all the processes must be run within the mobile device. The main contribution of the paper is to manage and combine semantic data and geographic information within a mobile device, and doing it without internet connection, and for an end-user application.
Proceedings of the 2012 4th International Conference on Intelligent Networking and Collaborative Systems, INCoS 2012, 2012
At the end of their technical studies, students have to present a final project in order to finis... more At the end of their technical studies, students have to present a final project in order to finish their degree. With this project, students prove that they have got all of the competences they should have acquired. Some competencies, such as the ability to communicate orally or the ability to argue may be evaluated during a face-to-face dissertation defense, but how to translate this evaluation scenario to a virtual environment is a challenge. This paper faces the problem of presenting dissertations in a virtual environment, to evaluate the aforementioned competences. The solution proposed, called Present@, is focused in teaching and technical dimensions, and is complemented with some materials and tutorials that help students to acquire those competences. Therefore, the paper shows Present@ as a solution to the problems that virtual universities have to face when dealing with the evaluation of final degree projects and particularly in their defense. Present@ has been tested over 131 students during six semesters and the results show that it actually helps students to acquire the desired competences in virtual environments. In addition, the analysis about the use of the tool has denoted that videos are an efficient mechanism to evaluate the ability to communicate of students and to work on transversal competencies. Some students also commented that the use of videos make the dissertation defense more natural and closer to face-to-face environments.
Physica B: Condensed Matter, 1999
The non-copper layered perovskite, Sr RuO , is expected to be a very useful reference material fo... more The non-copper layered perovskite, Sr RuO , is expected to be a very useful reference material for interpreting experiments on the high ¹ cuprate superconductors. A band structure calculation for Sr RuO is performed. Starting from the electronic structure determined in the local density formalism, the Dyson's equation with self-energies arising from the Hubbard hamiltonian is solved by diagonalizing the Green's function in k-space. The density of states is obtained by considering the renormalization factor and the lifetimes of the quasiparticle states in each pole of the interacting system. This leads to modification of the density of states calculated in the local density formalism, and the results fit experimental data not only in the position of peaks, but also in their intensity and in the number of states at Fermi level.
2012 Fourth International Conference on Intelligent Networking and Collaborative Systems, 2012
Several applications that support users when doing tourism have appeared during the last years. T... more Several applications that support users when doing tourism have appeared during the last years. These applications, though popular, have not become a reliable and dependable tourist assistant because they offer little personalization, which eventually may overwhelm users with too much information. An effective mobile application should store tourist information in a way that facilitates the identification of relevant points of interest to the user and the relevant information about them. The relevance of information depends also on the context. This paper presents an ontology that can store information about points of interest (POI), preferences and habits of users and time information. The presented ontology is aligned with the ontology Linked Geo Data to facilitate the importation of data to and from it. The ontology has been integrated into a mobile application called Itiner@ to create custom routes for each user based on his/her preferences, personal situation, means of transport, area to visit, date and duration of the visit. The main contribution of this work is to identify the relevant information to mobile touristic applications and to show how to use an ontology to improve the functionalities of geographic information system through the use of semantic information.
2009 EAEEIE Annual Conference, 2009
In the context of engineering studies, Virtual Laboratories (VL) are one of the most mentioned le... more In the context of engineering studies, Virtual Laboratories (VL) are one of the most mentioned learning tools. However, opinions on what different authors consider a virtual laboratory lead us to very disparate interpretations, with the consequent lack of consensus. In this work we focus on VL applied to e-learning in technical studies. The state-of-the-art concerning these laboratories is reviewed in
physica status solidi (b), 2000
We are interested in the description of the Mott-Hubbard transition from a perturbation theory ar... more We are interested in the description of the Mott-Hubbard transition from a perturbation theory arising from a two-dimensional Hubbard model. The self-energy within the random phase approximation presents some inconsistencies; one of them is that its imaginary part presents more than one zero, which is a violation of the Luttinger theorem. We use a Bogolyubov transformation and within a spin density wave mean field, we recalculate the self-energy in the new ground state, and it is able to describe the Mott-Hubbard transition, satisfying the Luttinger condition. 1999 Elsevier Science B.V. All rights reserved.
physica status solidi (b), 2002
In this paper we present a method for obtaining the quasiband structure and the renormalized dens... more In this paper we present a method for obtaining the quasiband structure and the renormalized density of quasistates of strongly correlated systems with antiferromagnetic ordering. We calculate the electronic structure of La 2 CuO 4 in order to test this method. The first step required is to calculate the electronic structure from the local density approximation (LDA) in order to obtain the initial non-interacting ground state. The LDA density of states in strongly correlated systems usually presents serious discrepancies with experimental results. As is well known, these discrepancies, fundamentally concerning photoemission, are due to the fact that the dynamic correlation effects are not taken into account within the LDA. In order to include these effects, we obtain a self-energy potential which allows the initial LDA electronic structure to connect with that of the antiferromagnetic ground state arising from a Bogolyubov-like transformation. Within this new ground state, we determine an antiferromagnetic self-energy by means of a spin density wave procedure, and the interacting Green function yields a density of states which is in reasonable agreement with the experimental photoemission result.
Physica B: Condensed Matter, 1997
... 1). Therefore, the new chosen fundamental state yields again a selfenergy which satisfies the... more ... 1). Therefore, the new chosen fundamental state yields again a selfenergy which satisfies the Luttinger theo rem with values of the band parameters closer to those for which superconductivity is found. (a) I@ 0.05 . ! i ' 0.00 .... . ...
Physica B: Condensed Matter, 2000
A quasiparticle structure calculation for Sr RuO is performed. Starting from the band structure d... more A quasiparticle structure calculation for Sr RuO is performed. Starting from the band structure determined in the local density formalism, the Dyson's equation with self-energies arising from the Hubbard Hamiltonian, is solved by diagonalizing the Green's function in k-space. The density of states is obtained by considering the renormalization factor and the lifetimes of the quasiparticle states. We also obtain the Fermi surface without and with the inclusion of the strong correlations e!ects.
Physica B: Condensed Matter, 1999
An approximated diagonalization of the Kondo lattice Hamiltonian is obtained considering an ansat... more An approximated diagonalization of the Kondo lattice Hamiltonian is obtained considering an ansatz based on strongly correlated many body states which are combinations of charged fermionic excitations coupled to a kind of spin wave. For determined values of the density of states of the non-interacting system and Kondo Hamiltonian parameter, there is an interval of the J parameter in which a new and interesting ground state appears.