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Search Results: 1 - 10 of 11397 matches for " Rafael Torrubia "
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La difícil objetividad de las pruebas de ensayo en la evaluación del rendimiento académico
Torrubia,Rafael; Pérez,Jorge;
Educación Médica , 2005, DOI: 10.4321/S1575-18132005000100006
Abstract: introduction: we explain two empirical experiences about the low objectivity of the essay exams and the possibilities of increasing this objectivity. method: participants in the study (92 university lecturers and 460 medical students) graded an essay exam on student assessment in three different situations: without criteria, with common criteria and with precise common criteria. results: the more precise the criteria, the more concordance there was among evaluators. in the two first situations, without precise criteria, lecturers assigned higher scores than students. in spite of precise common criteria, in the third situation there also appeared some discrepancies between evaluators. conclusions: the results show the necessity to use precise criteria to grade essay exams and to use objective testing methods to assess the students’ academic achievement.
Fiabilidad y validez de la versión espa ola de la Escala de Búsqueda de Sensaciones (Forma V)
Jorge Pérez,Rafael Torrubia
Revista Latinoamericana de Psicología , 1986,
Abstract: Por necesidades de investigación habíamos traducido al espa ol y utilizado la Sensation Seeking Scale-Eorm: V (SSS) desarrollada por Zuckerman y cols., (1978). El presente trabajo muestra fiabilidades alfa y test-reteseasí corno datos sobre validez estructural (construct validity) de la versión espa ola de la SSS. Utilizando diversas muestras de estudiantes catalanes, la citada escala aparece con acepo table fiabilidad y validez
La difícil objetividad de las pruebas de ensayo en la evaluación del rendimiento académico The hard objectivity of the essay exams in academic achievement assessment
Rafael Torrubia,Jorge Pérez
Educación Médica , 2005,
Abstract: Introducción: El objetivo del presente escrito es informar de dos experiencias empíricas donde se pone de manifiesto la poca objetividad de las pruebas de ensayo y de las posibilidades de reducir dicha deficiencia. Material y Métodos: Los participantes en el estudio (92 profesores de diversas universidades asistentes a un taller de formación y 460 estudiantes de segundo de Medicina ) puntuaron en tres situaciones diferentes la respuesta a una pregunta de ensayo sobre el tema de la evaluación del rendimiento académico de los estudiantes. En la primera situación cada evaluador usó sus propios criterios, en la segunda todos los evaluadores tuvieron unos criterios comunes y en la tercera se precisaban las puntuaciones concretas para dichos criterios. Resultados: Se evidenció la gran disparidad en las puntuaciones. Pero a medida que los criterios de evaluación fueron más precisos las puntuaciones fueron menos dispersas. Cuando la precisión en los criterios no fue máxima, los profesores asignaron mejores puntuaciones al examen que los estudiantes. A pesar de la reducción de la dispersión de las calificaciones cuando la precisión fue máxima, todavía existió una discrepancia considerable entre evaluadores. Conclusiones: Los resultados del estudio avalanla necesidad de usar criterios de corrección lo más precisos posibles a la hora de evaluar cualquier prueba de ensayo así como la oportunidad de usar pruebas más objetivas. Introduction: We explain two empirical experiences about the low objectivity of the essay exams and the possibilities of increasing this objectivity. Method: Participants in the study (92 university lecturers and 460 medical students) graded an essay exam on student assessment in three different situations: without criteria, with common criteria and with precise common criteria. Results: The more precise the criteria, the more concordance there was among evaluators. In the two first situations, without precise criteria, lecturers assigned higher scores than students. In spite of precise common criteria, in the third situation there also appeared some discrepancies between evaluators. Conclusions: The results show the necessity to use precise criteria to grade essay exams and to use objective testing methods to assess the students’ academic achievement.
Cued aversive classical conditioning in humans: The role of trait-anxiety  [PDF]
óscar Andión, Xavier Caseras, Miquel àngel Fullana, Alberto Fernandez-Teruel, Marc Ferrer, Miquel Casas, Rafael Torrubia
Open Journal of Psychiatry (OJPsych) , 2013, DOI: 10.4236/ojpsych.2013.32021
Abstract:

No study so far has specifically addressed the influence of individual differences in trait-anxiety on aversive classical conditioning as indexed by the startle reflex response. We compared the startle reflex responses between participants classified as high (n = 25) and low (n = 26) in trait-anxiety while undergoing a single-cue aversive classical conditioning procedure. High trait-anxiety group showed a greater startle response to the CS relative to the ITI at the post-acquisition compared with the pre-acquisition phase. Low trait-anxiety group did not show such a clear pattern of conditioning, and results from this group seem to be concealed by differences in the startle responses to the CS and the ITI during the pre-acquisition phase. However, a post-hoc analysis in which such differences at pre-conditioning were removed showed no conditioning effects in low trait-anxiety participants. Taking together, these results suggest differences between high and low trait-anxiety groups in the acquisition of the CS-US association. However, further research should clarify the unexpected pattern of responses shown by low trait-anxiety group.

Reconstrucción vésico-ureteral completa con íleon en un caso de tuberculosis genitourinaria
González Resina,Raquel; Congregado Ruiz,Belén; Medina López,Rafael A.; Torrubia Romero,Francisco J.;
Actas Urológicas Espa?olas , 2009, DOI: 10.4321/S0210-48062009000600017
Abstract: introduction:genitourinary tuberculosis represent 3,2% of the possible sites of the disease. the lack of treatment or an inadecuate one may lead to severe complications. we report a case and review thoroughly the literature of genitourinary tuberculosis which needed a complete vesico-ureteral reconstruction. clinical case: a 39 year old female patient with history of pulmonary tuberculosis who had lumbar pain and left ureterohydronephosis. she required a percutaneous urinary derivation and was diagnosed of tuberculosis by means of the urine culture. 18 months afterwards she had a right renal annulation and a left distal ureteral stenosis. a right nephectomy was performed and the left proximal ureter was desinserted accidentally, 1 cm below the pielo-ureteral junction, which required a permanent nephostomy. then her bladder became gradually retractile. because she was a young patient and had bad quality of life a complete reconstruction of her left urinary way was performed with an ileum made neobladder and neoureter. discussion and conclussions: bladder and ureter reconstruction with ileum is a good option in difficult cases of lack or irreversible damage of the urinary way. vesico-ureteral reconstruction letting urethral miction improves quality of life.
Factores pronósticos del carcinoma de células renales
Medina López,Rafael A.; Conde Sánchez,José M.; Congregado Ruiz,Carmen B.; González Resina,Raquel; Mármol Navarro,Salvador; Torrubia Romero,Francisco J.;
Actas Urológicas Espa?olas , 2009, DOI: 10.4321/S0210-48062009000500016
Abstract: renal cancer has been increasingly diagnosed in recent decades. in addition, morphological diversity of renal neoplasms has led to consider that the concept of renal cell (rc) carcinoma encompasses a wide variety of conditions. the recently publshed erocare-4 study showed a 5-year overall survival rate of 59.2%. in this and any other neoplastic disease, determination of adequate prognostic factors would help decide the most appropriate therapeutic strategy in each case, guide future treatments, and develop specific follow-up schemes for our patients. the diferent prognostic factors for rc may currently be classified into four groups: anatomical, clinical, histological and molecular. this paper analyzes these prognostic factors and reviews the nomograms most commonly used.
Reflujo vesicoureteral tras trasplante renal en la edad pediátrica
Barrero Candau,Rafael; Fernández Hurtado,Miguel; García Merino,Francisco; Fijo López-Viota,Julia; León Due?as,Eduardo; Torrubia Romero,Francisco;
Archivos Espa?oles de Urología (Ed. impresa) , 2008, DOI: 10.4321/S0004-06142008000200035
Abstract: objectives: we analyze the frequency of vesicoureteral reflux and the factors that favor its appearance after kidney transplantation in pediatric patients. methods: this retrospective analysis examined the prevalence of posttransplant vesicoureteral reflux in a total of 201 kidney transplants performed in children at our centre between 1978 and 2006. in patients who required corrective surgery for this problem, we analyzed pretransplant residual diuresis, pretransplant pathology and posttransplant problems related to vesicoureteral reflux. we also analyzed the form of presentation, whether reflux was to the graft or to the native kidney, degree of reflux, and surgical technique used to correct reflux. results: twelve patients (5.9%) needed surgery to correct reflux to the graft (10 children) or to the native kidney (2 children). reflux presented as urinary tract infection in 11 children and progressive graft failure in 1. urethrovesical disorders that favoured vesicoureteral reflux were present in 10 patients (noncompliant bladder, detrusor overactivity, posterior urethral valves, urethral stenosis). lengthening the submucosal tunnel stopped urinary tract infections in all 12 patients, whereas 6-month voiding cystourethrograms showed resolution in 10 patients and reduction in the degree of reflux in 2. conclusion: the high percentage of posttransplant vesicoureteral reflux in pediatric patients was related with higher frequency of vesicourethral pathology in children who received the transplant. in children with pretransplant urethrovesical anomalies we recommend an initial technique which utilizes a longer submucosal tunnel during implantation, such as the lich-gregoir.
Step Size Bound of the Sequential Partial Update LMS Algorithm with Periodic Input Signals
Ramos Pedro,Torrubia Roberto,López Ana,Salinas Ana
EURASIP Journal on Audio, Speech, and Music Processing , 2007,
Abstract: This paper derives an upper bound for the step size of the sequential partial update (PU) LMS adaptive algorithm when the input signal is a periodic reference consisting of several harmonics. The maximum step size is expressed in terms of the gain in step size of the PU algorithm, defined as the ratio between the upper bounds that ensure convergence in the following two cases: firstly, when only a subset of the weights of the filter is updated during every iteration; and secondly, when the whole filter is updated at every cycle. Thus, this gain in step-size determines the factor by which the step size parameter can be increased in order to compensate the inherently slower convergence rate of the sequential PU adaptive algorithm. The theoretical analysis of the strategy developed in this paper excludes the use of certain frequencies corresponding to notches that appear in the gain in step size. This strategy has been successfully applied in the active control of periodic disturbances consisting of several harmonics, so as to reduce the computational complexity of the control system without either slowing down the convergence rate or increasing the residual error. Simulated and experimental results confirm the expected behavior.
Step Size Bound of the Sequential Partial Update LMS Algorithm with Periodic Input Signals
Pedro Ramos,Roberto Torrubia,Ana López,Ana Salinas
EURASIP Journal on Audio, Speech, and Music Processing , 2006, DOI: 10.1155/2007/10231
Abstract: This paper derives an upper bound for the step size of the sequential partial update (PU) LMS adaptive algorithm when the input signal is a periodic reference consisting of several harmonics. The maximum step size is expressed in terms of the gain in step size of the PU algorithm, defined as the ratio between the upper bounds that ensure convergence in the following two cases: firstly, when only a subset of the weights of the filter is updated during every iteration; and secondly, when the whole filter is updated at every cycle. Thus, this gain in step-size determines the factor by which the step size parameter can be increased in order to compensate the inherently slower convergence rate of the sequential PU adaptive algorithm. The theoretical analysis of the strategy developed in this paper excludes the use of certain frequencies corresponding to notches that appear in the gain in step size. This strategy has been successfully applied in the active control of periodic disturbances consisting of several harmonics, so as to reduce the computational complexity of the control system without either slowing down the convergence rate or increasing the residual error. Simulated and experimental results confirm the expected behavior.
Sustainable and Economic Alternative for the Electric Supply of Isolated Communities in the Brazilian Off-Grid Systems  [PDF]
Rebeca Doctors, Rafael Kelman
Journal of Power and Energy Engineering (JPEE) , 2017, DOI: 10.4236/jpee.2017.59012
Abstract: Roughly 99% of the demand for electricity in Brazil is supplied by a national interconnected grid. The remaining 1% is spread in several “isolated systems” of the Amazon region—mini-grids that rely on expensive diesel gensets due to high commodity and transportation costs. The isolated systems also have remote communities disconnected altogether from the mini-grids with inadequate health, education and leisure services. These communities are precariously supplied by small inefficient diesel gensets that run for a few hours per day. In this article, we propose a sustainable and economic alternative for the electric supply of the remote communities of isolated systems through a combination of photovoltaic solar generation and storage. The objective is to improve access to electricity with savings for the communities. The present paper outlines a public policy to meet this objective.
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