Germán Ros | Universidad de Alcala (original) (raw)
Papers by Germán Ros
Journal for the Study of Education and Development
ABSTRACT Curriculum integration from a STEAM transdisciplinary perspective represents a profound ... more ABSTRACT Curriculum integration from a STEAM transdisciplinary perspective represents a profound challenge. This study delves into a transdisciplinary approach to primary education and the role of the arts through two STEAM projects in a programme for gifted students in Madrid (Spain). Participants include 111 students from eight groups (11–12 years old), five teachers and four external professionals. The teachers fulfill the dual role of both teacher and researcher, using participant and non-participant observation, video recordings, interviews and classroom journals and questionnaires. All the findings have been triangulated and coded by means of Activity Theory, using Atlas.ti8 software and statistical analysis. The results show the significance of learning and the creation of meaningful experiences as being related to a high degree of motivation and satisfaction, and to the integration of diverse areas in a participatory process in which the arts play a disciplinary and integrating role. A transdisciplinary STEAM approach is presented that could be paradigmatic for the field of primary education.
Abstract: The normalization constant of the lateral distribution function (LDF) of an extensive a... more Abstract: The normalization constant of the lateral distribution function (LDF) of an extensive air shower is a monotonous (almost linear) increasing function of the energy of the primary. Therefore, the interpo-lated signal at some fixed distance from the core can be calibrated to estimate the energy of the shower. There is, somehow surprisingly, a reconstructed optimal distance, ropt, at which the effects on the inferred signal, S(ropt), of the uncertainties on true core location, LDF functional form and shower-to-shower fluctuations are minimized. We calculate the value of ropt as a function of surface detector separation, energy and zenith angle and we demonstrate the advantage of using the ropt value of each individual shower instead of a same fixed distance for every shower, specially in dealing with events with saturated stations. The effects on the determined spectrum are also shown.
Eurasia Journal of Mathematics, Science and Technology Education
In this study, the process of design, implementation, evaluation, and redesign of a Teaching-Lear... more In this study, the process of design, implementation, evaluation, and redesign of a Teaching-Learning Sequence (TLS) on simple machines for students of 9-12 years old is shown according to the principles of Design Based Research. The aim is to create a TLS that satisfactorily addresses the conceptual difficulties inherent to the object of study and that succeeds in fostering selfregulation skills and creativity. Both qualitative (focus group, semi-structured interviews, students' reports, and teacher's class notes) and quantitative instruments (a validated questionnaire and an ad hoc one with content validation by experts) are used. The statistical analysis of the questionnaires and the narrative analysis of the qualitative instruments have been triangulated. The results show that students manage to address the conceptual and procedural difficulties of the object of study while developing emotional (enjoyment and self-efficacy) and cognitive (metacognition) self-regulation skills, as well as creativity related to the scientific and artisan domains.
Este libro supone la recopilacion de los trabajos que presentaron en forma de conferencias los pa... more Este libro supone la recopilacion de los trabajos que presentaron en forma de conferencias los participantes en las 4as Jornadas de Jovenes Investigadores de la Universidad de Alcala, organizadas por el Departamento de Fisica con el apoyo del Vicerrectorado de Postgrado, y que se celebraron durante los dias 28 a 30 de Noviembre de 2012. La novedad respecto a las tres jornadas anteriores, en las que todos los contenidos se cineron a la Ciencia y Tecnologia, es la incorporacion a estas 4as Jornadas de las disciplinas de Humanidades, lo que permite dar una proyeccion a los trabajos de todos los estudiantes de doctorado de la Universidad de Alcala, porque una exigencia de las jornadas ha sido que todos los participantes estuvieran en el periodo de realizacion de sus tesis doctorales . La presente publicacion pretende ser un primer estimulo institucional a su actividad cientifica, en la que se ha cuidado el rigor de los contenidos de los trabajos mediante la labor de revision que han lle...
arXiv: Astrophysics, 2007
The normalization constant of the lateral distribution function (LDF) of an extensive air shower ... more The normalization constant of the lateral distribution function (LDF) of an extensive air shower is a monotonous (almost linear) increasing function of the energy of the primary. Therefore, the interpolated signal at some fixed distance from the core can be calibrated to estimate the energy of the shower. There is, somehow surprisingly, a reconstructed optimal distance, r_{opt}, at which the effects on the inferred signal, S(r_{opt}), of the uncertainties on true core location, LDF functional form and shower-to-shower fluctuations are minimized. We calculate the value of r_{opt} as a function of surface detector separation, energy and zenith angle and we demonstrate the advantage of using the r_{opt} value of each individual shower instead of a same fixed distance for every shower, specially in dealing with events with saturated stations. The effects on the determined spectrum are also shown.
Existe un consenso amplio en la comunidad cientifica sobre la necesidad de que los enormes y urge... more Existe un consenso amplio en la comunidad cientifica sobre la necesidad de que los enormes y urgentes desafios que afectan a las ciencias biologicas sean abordados pluridisciplinarmente y en que la actual revolucion de la Biologia es fruto de un cambio cualitativo en la manera de pensar los misterios de la vida, cambio en el que la Fisica esta jugando un papel fundamental. Entonces, por que las universidades espanolas siguen ofreciendo a los futuros graduados en Biologia una formacion compartimentalizada, en la que la F.sica es considerada como una simple herramienta? .Que se esta haciendo en otras universidades europeas y norteamericanas?
The current methods to determine the primary energy of ultra -high energy cosmic rays (UHECRs) ar... more The current methods to determine the primary energy of ultra -high energy cosmic rays (UHECRs) are di fferent when dealing with hadron or photon primaries. The current experiments co mbine two di fferent techniques, an array of surface detectors and fluorescence telescopes. The latter allow an almost calorim etric measurement of the primary energy. Thus, hadron-init iated showers detected by both type of detectors are used to calibrate the e nergy estimator from the surface array (usually the interpo lated signal at a certain distance from the shower core S(r0)) with the primary energy. On the other hand, this calibrati on is not feasible when searching for photon primaries since no high energy photon h as been unambiguously detected so far. Therefore, pure Mont e Carlo parametrizations are used instead. In this work, we present a new method to determine the primary energy of hadron-induced showers in a hybrid experiment bas ed on a technique previously developed for photon primarie...
Esta tesis se enmarca dentro del estudio de los rayos cosmicos de ultra-alta energia, aquellos a ... more Esta tesis se enmarca dentro del estudio de los rayos cosmicos de ultra-alta energia, aquellos a los que se dedica el Observatorio Pierre Auger. Tras una breve introduccion, en el segundo capitulo se resumen los aspectos basicos de la fisica de rayos cosmicos, desde su espectro de energia, composicion y su posible origen, hasta las cuestiones que aun permanecen desconocidas. En el siguiente capitulo se describen las caracteristicas singulares del Observatorio Pierre Auger y se muestran los resultados publicados mas importantes hasta este momento. En los capitulos siguientes se abordan los temas centrales de este trabajo: la determinacion de la energia y la composicion de los rayos cosmicos de ultra-alta energia a partir de su deteccion con detectores de superficie. Inicialmente se analiza la determinacion de la energia. Se ha propuesto una nueva tecnica, y se ha demostrado su aplicabilidad en los detectores de superficie. Ademas, se ha mostrado que es significativamente mejor que la...
Este libro supone la recopilacion de los trabajos que presentaron en forma de conferencias los pa... more Este libro supone la recopilacion de los trabajos que presentaron en forma de conferencias los participantes en las 3as. Jornadas de Jovenes Investigadores de la Universidad de Alcala, organizadas por el Departamento de Fisica, y que se celebraron durante los dias 1 a 3 de Diciembre de 2010. Todos los participantes estan en el periodo de realizacion de sus tesis doctorales y la presente publicacion representa un espaldarazo a su actividad cientifica. Se ha cuidado el rigor cientifico de los contenidos de los trabajos mediante la labor de revision que han llevado a cabo especialistas de cada una de las areas. Con este tercera edicion, podemos afirmar que estas jornadas han comenzado ya a formar parte de la actividad academica y cientifica de nuestra Universidad, que con caracter bianual, involucra a los doctorandos que se incorporan a la Universidad de Alcala, ofreciendoles la posibilidad de este apoyo institucional. La novedad en estas 3as. Jornadas es la edicion adicional de un DVD...
Revista de Investigación Educativa
La metodología de aula invertida tiene cada vez mayor difusión en el ámbito universitario pero su... more La metodología de aula invertida tiene cada vez mayor difusión en el ámbito universitario pero sus implicaciones no están plenamente analizadas aún. En este trabajo se destacan los aspectos clave para una implementación exitosa del aula invertida y se incluyen objetivos didáctico-disciplinares imprescindibles para el aprendizaje significativo de las Ciencias Experimentales. El estudio se ha realizado en el contexto de la asignatura de Ciencias de la Materia y la Energía en tres titulaciones vinculadas al Grado en Magisterio de Educación Primaria y abarca más de 200 estudiantes, tanto en el grupo experimental como en el grupo control. Este estudio se ha abordado a través de tres instrumentos: el rendimiento académico de las distintas partes de la asignatura; grupos de discusión del personal docente implicado; y cuestionario final cumplimentado por el alumnado. El análisis de los mismos evidencia una mejora significativa en los resultados académicos de forma mayoritaria, al igual que ...
Radiation Physics and Chemistry
Plastic scintillators are widely used as particle detectors in many fields, mainly, medicine, par... more Plastic scintillators are widely used as particle detectors in many fields, mainly, medicine, particle physics and astrophysics. Traditionally, they are coupled to a photo-multplier (PMT) but now silicon photo-multipliers (SiPM) are evolving as a promising robust alternative, specially in space born experiments since plastic scintillators may be a light option for low Earth orbit missions. Therefore it is timely to make a new analysis of the optimal design for experiments based on plastic scintillators in realistic conditions in such a configuration. We analyze here their response to an isotropic flux of electron and proton primaries in the energy range from 1 MeV to 1 GeV, a typical scenario for cosmic ray or space weather experiments, through detailed GEANT4 simulations. First, we focus on the effect of increasing the ratio between the plastic volume and the area of the photo-detector itself and, second, on the benefits of using a reflective coating around the plastic, the most common technique to increase light collection efficiency. In order to achieve a general approach, it is necessary to consider several detector setups. Therefore, we have performed a full set of simulations using the highly tested GEANT4 simulation tool: several parameters have been analyzed such as the energy lost in the coating, the deposited energy in the scintillator, the optical absorption, the fraction of scintillation photons that are not detected, the light collection at the photo-detector, the pulse shape and its time parameters and finally, other design parameters as the surface roughness, the coating reflectivity and the case of a scintillator with two decay components. This work could serve as a guide on the design of future experiments based on the use of plastic scintillators.
2015 IEEE Intelligent Vehicles Symposium (IV), 2015
Semantic labelling of urban images is a crucial component towards autonomous driving. The accurac... more Semantic labelling of urban images is a crucial component towards autonomous driving. The accuracy of current methods is highly dependent on the training set being used and drops drastically when the distribution in the test image does not match the expected distribution of the training set. This situation will inevitably occur, as for instance, when the illumination changes from daytime to dusk. To address this problem we propose a fast unsupervised image transformation approach following a global color transfer strategy. Our proposal generalizes classical one-to-one color transfer schemes to the more suitable one-to-many scheme. In addition, our approach can naturally deal with the temporal consistency of video streams to perform a coherent transformation. We demonstrate the benefits of our proposal in two publicly available datasets using different state-of-the-art semantic labelling frameworks.
Astroparticle Physics, 2015
The current methods to determine the primary energy of ultra-high energy cosmic rays (UHECRs) are... more The current methods to determine the primary energy of ultra-high energy cosmic rays (UHECRs) are different when dealing with hadron or photon primaries. The current experiments combine two different techniques, an array of surface detectors and fluorescence telescopes. The latter allow an almost calorimetric measurement of the primary energy. Thus, hadron-initiated showers detected by both type of detectors are used to calibrate the energy estimator from the surface array (usually the interpolated signal at a certain distance from the shower core S (r 0)) with the primary energy. On the other hand, this calibration is not feasible when searching for photon primaries since no high energy photon has been unambiguously detected so far. Therefore, pure Monte Carlo parametrizations are used instead. In this work, we present a new method to determine the primary energy of hadron-induced showers in a hybrid experiment based on a technique previously developed for photon primaries. It consists on a set of calibration curves that relate the surface energy estimator, S (r 0), and the depth of maximum development of the shower, X max , obtained from the fluorescence telescopes. Then, the primary energy can be determined from pure surface information since S (r 0) and the zenith angle of the incoming shower are only needed. Considering a mixed sample of ultra-high energy proton and iron primaries and taking into account the reconstruction uncertainties and shower to shower fluctuations, we demonstrate that the primary energy may be determined with a systematic uncertainty below 1% and resolution around 16% in the energy range from 10 18.5 to 10 19.6 eV. Several array geometries, the shape of the energy error distributions and the uncertainties due to the unknown composition of the primary flux have been analyzed as well.
A new family of parameters intended for composition studies is presented. They make exclusive use... more A new family of parameters intended for composition studies is presented. They make exclusive use of surface data combining the information from the total signal at each triggered detector and the array geometry. We perform an analytical study of these composition estimators in order to assess their reliability, stability and possible optimization. The influence of the different slopes of the
Journal for the Study of Education and Development
ABSTRACT Curriculum integration from a STEAM transdisciplinary perspective represents a profound ... more ABSTRACT Curriculum integration from a STEAM transdisciplinary perspective represents a profound challenge. This study delves into a transdisciplinary approach to primary education and the role of the arts through two STEAM projects in a programme for gifted students in Madrid (Spain). Participants include 111 students from eight groups (11–12 years old), five teachers and four external professionals. The teachers fulfill the dual role of both teacher and researcher, using participant and non-participant observation, video recordings, interviews and classroom journals and questionnaires. All the findings have been triangulated and coded by means of Activity Theory, using Atlas.ti8 software and statistical analysis. The results show the significance of learning and the creation of meaningful experiences as being related to a high degree of motivation and satisfaction, and to the integration of diverse areas in a participatory process in which the arts play a disciplinary and integrating role. A transdisciplinary STEAM approach is presented that could be paradigmatic for the field of primary education.
Abstract: The normalization constant of the lateral distribution function (LDF) of an extensive a... more Abstract: The normalization constant of the lateral distribution function (LDF) of an extensive air shower is a monotonous (almost linear) increasing function of the energy of the primary. Therefore, the interpo-lated signal at some fixed distance from the core can be calibrated to estimate the energy of the shower. There is, somehow surprisingly, a reconstructed optimal distance, ropt, at which the effects on the inferred signal, S(ropt), of the uncertainties on true core location, LDF functional form and shower-to-shower fluctuations are minimized. We calculate the value of ropt as a function of surface detector separation, energy and zenith angle and we demonstrate the advantage of using the ropt value of each individual shower instead of a same fixed distance for every shower, specially in dealing with events with saturated stations. The effects on the determined spectrum are also shown.
Eurasia Journal of Mathematics, Science and Technology Education
In this study, the process of design, implementation, evaluation, and redesign of a Teaching-Lear... more In this study, the process of design, implementation, evaluation, and redesign of a Teaching-Learning Sequence (TLS) on simple machines for students of 9-12 years old is shown according to the principles of Design Based Research. The aim is to create a TLS that satisfactorily addresses the conceptual difficulties inherent to the object of study and that succeeds in fostering selfregulation skills and creativity. Both qualitative (focus group, semi-structured interviews, students' reports, and teacher's class notes) and quantitative instruments (a validated questionnaire and an ad hoc one with content validation by experts) are used. The statistical analysis of the questionnaires and the narrative analysis of the qualitative instruments have been triangulated. The results show that students manage to address the conceptual and procedural difficulties of the object of study while developing emotional (enjoyment and self-efficacy) and cognitive (metacognition) self-regulation skills, as well as creativity related to the scientific and artisan domains.
Este libro supone la recopilacion de los trabajos que presentaron en forma de conferencias los pa... more Este libro supone la recopilacion de los trabajos que presentaron en forma de conferencias los participantes en las 4as Jornadas de Jovenes Investigadores de la Universidad de Alcala, organizadas por el Departamento de Fisica con el apoyo del Vicerrectorado de Postgrado, y que se celebraron durante los dias 28 a 30 de Noviembre de 2012. La novedad respecto a las tres jornadas anteriores, en las que todos los contenidos se cineron a la Ciencia y Tecnologia, es la incorporacion a estas 4as Jornadas de las disciplinas de Humanidades, lo que permite dar una proyeccion a los trabajos de todos los estudiantes de doctorado de la Universidad de Alcala, porque una exigencia de las jornadas ha sido que todos los participantes estuvieran en el periodo de realizacion de sus tesis doctorales . La presente publicacion pretende ser un primer estimulo institucional a su actividad cientifica, en la que se ha cuidado el rigor de los contenidos de los trabajos mediante la labor de revision que han lle...
arXiv: Astrophysics, 2007
The normalization constant of the lateral distribution function (LDF) of an extensive air shower ... more The normalization constant of the lateral distribution function (LDF) of an extensive air shower is a monotonous (almost linear) increasing function of the energy of the primary. Therefore, the interpolated signal at some fixed distance from the core can be calibrated to estimate the energy of the shower. There is, somehow surprisingly, a reconstructed optimal distance, r_{opt}, at which the effects on the inferred signal, S(r_{opt}), of the uncertainties on true core location, LDF functional form and shower-to-shower fluctuations are minimized. We calculate the value of r_{opt} as a function of surface detector separation, energy and zenith angle and we demonstrate the advantage of using the r_{opt} value of each individual shower instead of a same fixed distance for every shower, specially in dealing with events with saturated stations. The effects on the determined spectrum are also shown.
Existe un consenso amplio en la comunidad cientifica sobre la necesidad de que los enormes y urge... more Existe un consenso amplio en la comunidad cientifica sobre la necesidad de que los enormes y urgentes desafios que afectan a las ciencias biologicas sean abordados pluridisciplinarmente y en que la actual revolucion de la Biologia es fruto de un cambio cualitativo en la manera de pensar los misterios de la vida, cambio en el que la Fisica esta jugando un papel fundamental. Entonces, por que las universidades espanolas siguen ofreciendo a los futuros graduados en Biologia una formacion compartimentalizada, en la que la F.sica es considerada como una simple herramienta? .Que se esta haciendo en otras universidades europeas y norteamericanas?
The current methods to determine the primary energy of ultra -high energy cosmic rays (UHECRs) ar... more The current methods to determine the primary energy of ultra -high energy cosmic rays (UHECRs) are di fferent when dealing with hadron or photon primaries. The current experiments co mbine two di fferent techniques, an array of surface detectors and fluorescence telescopes. The latter allow an almost calorim etric measurement of the primary energy. Thus, hadron-init iated showers detected by both type of detectors are used to calibrate the e nergy estimator from the surface array (usually the interpo lated signal at a certain distance from the shower core S(r0)) with the primary energy. On the other hand, this calibrati on is not feasible when searching for photon primaries since no high energy photon h as been unambiguously detected so far. Therefore, pure Mont e Carlo parametrizations are used instead. In this work, we present a new method to determine the primary energy of hadron-induced showers in a hybrid experiment bas ed on a technique previously developed for photon primarie...
Esta tesis se enmarca dentro del estudio de los rayos cosmicos de ultra-alta energia, aquellos a ... more Esta tesis se enmarca dentro del estudio de los rayos cosmicos de ultra-alta energia, aquellos a los que se dedica el Observatorio Pierre Auger. Tras una breve introduccion, en el segundo capitulo se resumen los aspectos basicos de la fisica de rayos cosmicos, desde su espectro de energia, composicion y su posible origen, hasta las cuestiones que aun permanecen desconocidas. En el siguiente capitulo se describen las caracteristicas singulares del Observatorio Pierre Auger y se muestran los resultados publicados mas importantes hasta este momento. En los capitulos siguientes se abordan los temas centrales de este trabajo: la determinacion de la energia y la composicion de los rayos cosmicos de ultra-alta energia a partir de su deteccion con detectores de superficie. Inicialmente se analiza la determinacion de la energia. Se ha propuesto una nueva tecnica, y se ha demostrado su aplicabilidad en los detectores de superficie. Ademas, se ha mostrado que es significativamente mejor que la...
Este libro supone la recopilacion de los trabajos que presentaron en forma de conferencias los pa... more Este libro supone la recopilacion de los trabajos que presentaron en forma de conferencias los participantes en las 3as. Jornadas de Jovenes Investigadores de la Universidad de Alcala, organizadas por el Departamento de Fisica, y que se celebraron durante los dias 1 a 3 de Diciembre de 2010. Todos los participantes estan en el periodo de realizacion de sus tesis doctorales y la presente publicacion representa un espaldarazo a su actividad cientifica. Se ha cuidado el rigor cientifico de los contenidos de los trabajos mediante la labor de revision que han llevado a cabo especialistas de cada una de las areas. Con este tercera edicion, podemos afirmar que estas jornadas han comenzado ya a formar parte de la actividad academica y cientifica de nuestra Universidad, que con caracter bianual, involucra a los doctorandos que se incorporan a la Universidad de Alcala, ofreciendoles la posibilidad de este apoyo institucional. La novedad en estas 3as. Jornadas es la edicion adicional de un DVD...
Revista de Investigación Educativa
La metodología de aula invertida tiene cada vez mayor difusión en el ámbito universitario pero su... more La metodología de aula invertida tiene cada vez mayor difusión en el ámbito universitario pero sus implicaciones no están plenamente analizadas aún. En este trabajo se destacan los aspectos clave para una implementación exitosa del aula invertida y se incluyen objetivos didáctico-disciplinares imprescindibles para el aprendizaje significativo de las Ciencias Experimentales. El estudio se ha realizado en el contexto de la asignatura de Ciencias de la Materia y la Energía en tres titulaciones vinculadas al Grado en Magisterio de Educación Primaria y abarca más de 200 estudiantes, tanto en el grupo experimental como en el grupo control. Este estudio se ha abordado a través de tres instrumentos: el rendimiento académico de las distintas partes de la asignatura; grupos de discusión del personal docente implicado; y cuestionario final cumplimentado por el alumnado. El análisis de los mismos evidencia una mejora significativa en los resultados académicos de forma mayoritaria, al igual que ...
Radiation Physics and Chemistry
Plastic scintillators are widely used as particle detectors in many fields, mainly, medicine, par... more Plastic scintillators are widely used as particle detectors in many fields, mainly, medicine, particle physics and astrophysics. Traditionally, they are coupled to a photo-multplier (PMT) but now silicon photo-multipliers (SiPM) are evolving as a promising robust alternative, specially in space born experiments since plastic scintillators may be a light option for low Earth orbit missions. Therefore it is timely to make a new analysis of the optimal design for experiments based on plastic scintillators in realistic conditions in such a configuration. We analyze here their response to an isotropic flux of electron and proton primaries in the energy range from 1 MeV to 1 GeV, a typical scenario for cosmic ray or space weather experiments, through detailed GEANT4 simulations. First, we focus on the effect of increasing the ratio between the plastic volume and the area of the photo-detector itself and, second, on the benefits of using a reflective coating around the plastic, the most common technique to increase light collection efficiency. In order to achieve a general approach, it is necessary to consider several detector setups. Therefore, we have performed a full set of simulations using the highly tested GEANT4 simulation tool: several parameters have been analyzed such as the energy lost in the coating, the deposited energy in the scintillator, the optical absorption, the fraction of scintillation photons that are not detected, the light collection at the photo-detector, the pulse shape and its time parameters and finally, other design parameters as the surface roughness, the coating reflectivity and the case of a scintillator with two decay components. This work could serve as a guide on the design of future experiments based on the use of plastic scintillators.
2015 IEEE Intelligent Vehicles Symposium (IV), 2015
Semantic labelling of urban images is a crucial component towards autonomous driving. The accurac... more Semantic labelling of urban images is a crucial component towards autonomous driving. The accuracy of current methods is highly dependent on the training set being used and drops drastically when the distribution in the test image does not match the expected distribution of the training set. This situation will inevitably occur, as for instance, when the illumination changes from daytime to dusk. To address this problem we propose a fast unsupervised image transformation approach following a global color transfer strategy. Our proposal generalizes classical one-to-one color transfer schemes to the more suitable one-to-many scheme. In addition, our approach can naturally deal with the temporal consistency of video streams to perform a coherent transformation. We demonstrate the benefits of our proposal in two publicly available datasets using different state-of-the-art semantic labelling frameworks.
Astroparticle Physics, 2015
The current methods to determine the primary energy of ultra-high energy cosmic rays (UHECRs) are... more The current methods to determine the primary energy of ultra-high energy cosmic rays (UHECRs) are different when dealing with hadron or photon primaries. The current experiments combine two different techniques, an array of surface detectors and fluorescence telescopes. The latter allow an almost calorimetric measurement of the primary energy. Thus, hadron-initiated showers detected by both type of detectors are used to calibrate the energy estimator from the surface array (usually the interpolated signal at a certain distance from the shower core S (r 0)) with the primary energy. On the other hand, this calibration is not feasible when searching for photon primaries since no high energy photon has been unambiguously detected so far. Therefore, pure Monte Carlo parametrizations are used instead. In this work, we present a new method to determine the primary energy of hadron-induced showers in a hybrid experiment based on a technique previously developed for photon primaries. It consists on a set of calibration curves that relate the surface energy estimator, S (r 0), and the depth of maximum development of the shower, X max , obtained from the fluorescence telescopes. Then, the primary energy can be determined from pure surface information since S (r 0) and the zenith angle of the incoming shower are only needed. Considering a mixed sample of ultra-high energy proton and iron primaries and taking into account the reconstruction uncertainties and shower to shower fluctuations, we demonstrate that the primary energy may be determined with a systematic uncertainty below 1% and resolution around 16% in the energy range from 10 18.5 to 10 19.6 eV. Several array geometries, the shape of the energy error distributions and the uncertainties due to the unknown composition of the primary flux have been analyzed as well.
A new family of parameters intended for composition studies is presented. They make exclusive use... more A new family of parameters intended for composition studies is presented. They make exclusive use of surface data combining the information from the total signal at each triggered detector and the array geometry. We perform an analytical study of these composition estimators in order to assess their reliability, stability and possible optimization. The influence of the different slopes of the