Tendencia futura de la instrumentación inteligente

Peer Reviewe

A novel sensor-bridge-to-microcontroller interface

Sensor bridges are usually interfaced to microcontrollers by supplying the bridge with a voltage or current and digitizing the resulting voltage or current after being amplified and low-pass filtered. This paper proposes an alternative method to interface a sensor bridge to a microcontroller that does not need any active component between the bridge and the microcontroller The bridge is considered a network with three inputs and one output. The resistance of each input to the output depends on the measurand. Using each input in turn to charge a capacitor connected to the bridge output yields three different time intervals. For a full bridge (a sensor at each arm), the ratio between the difference between two time intervals and the third time interval yields the fractional resistance change. Two-point calibration reduces zero and gain errors attributable to the electrical parameters of the ports of the microcontroller. The absolute error for a 15 psi (103.4 kPa) pressure sensor with 5000 Ω arms and a full-scale output of 125 mV is below 0.05% of full scale, which is better than 1 LSB for an 11 bit ADCPeer Reviewe

Error analysis and reduction for a simple sensor-microcontroller interface

Error analysis of a resistive sensor-to-microcontroller interface based on pulse-width modulation and time–ratio measurement shows that internal input and output resistances in microcontroller digital ports produce zero, gain and nonlinearity errors. The time–ratio measurement technique cancels these errors when the sensor resistance equals the reference resistor and reduces errors around that point. We propose two simple methods of reducing those errors for sensors with a wide dynamic range. Both methods use time–ratio measurements. The first method uses several reference resistors covering the sensor resistance range; the second method uses two-point calibration. The second method is more efficient and yields errors that can be smaller than 0.5 Ω for a sensor resistance from about 600 Ω to 3550 Ω.Peer Reviewe

Flipped Classroom to Improve University Student Centered Learning and Academic Performance

In recent years, educational research has focused on analyzing significant differences in the academic performance of university students according to the intervention model of the traditional methodology vs. the flipped classroom. This empirical-analytical research is based on a quasi-experimental design with non-equivalent groups. The results reveal significant differences on the average grades of university students; those participating in the flipped classroom obtained higher scores than students following a traditional methodology, regardless of the specialization. Moreover, this research concludes that the flipped classroom approach offers an opportunity to transform the traditional system by improving the classroom environment, the teaching-learning process and the student’s assessment

Validação do questionário sobre a utilização de Dispositivos Móveis Interativos no Ensino Superior

Objetivo: this study aims to design and validate a questionnaire to measure the students’ perception of the use of IRS as a technopedagogical resource in the classroom. Method: a 24 items questionnaire (Interactive Response System for the Improvement of the Teaching-Learning Process) was designed ad hoc for this research and applied to 142 university students. Results: both the exploratory and confirmatory factorial analysis yielded 3 dimensions: classroom environment, teaching-learning processes and learning assessment. The results obtained both in reliability (Cronbach’s alpha= 0.955) and in the Confirmatory Factor Analysis (χ2/df=1.944, CFI=0.97; GFI=0.78; RMR=0.077; RMSEA=0.08) reveal highly satisfactory indices. Conclusion: statistical analyses confirm that this instrument is a valid, reliable, and easy-to-apply tool for professors to evaluate the student perception of student-centred learning.Objetivo: el presente estudio tiene como objetivo diseñar y validar un cuestionario que permita medir la percepción de los estudiantes universitarios del uso de los MIR como recurso tecnopedagógico en el aula. Método: se aplicó el cuestionario Mandos Interactivos de Respuesta para la Mejora del Proceso de Enseñanza-Aprendizaje, creado ad hoc para esta investigación, que está formado por 24 ítems, aplicado a 142 estudiantes universitarios. Resultados: tanto el análisis factorial exploratorio como el confirmatorio arrojan tres dimensiones: ambiente de clase, los procesos de enseñanza-aprendizaje y la evaluación. Los resultados obtenidos tanto en la fiabilidad (alfa de Cronbach 0.955) como en el análisis factorial confirmatorio (χ2/gl=1.944, CFI=0.97; GFI=0.78; RMR=0.077; RMSEA=0.08) arrojan índices altamente satisfactorios. Conclusión: los análisis estadísticos muestran que este instrumento es una herramienta válida, fiable y de fácil aplicación para el docente que le permitirá evaluar la experiencia del alumnado sobre el aprendizaje centrado en el estudiante.Objetivo: o presente estudo visa conceber e validar um instrumento para medir a percepção dos estudantes universitários sobre a utilização dos Dispositivos Móveis Interativos (MIR) como recurso tecnológico-pedagógico na sala de aula. Método: foi aplicado o questionário “Mandos Interactivos de Respuesta para la Mejora del Proceso de Enseñanza-Aprendizaje”, criado ad hoc para esta investigação, composto por 24 itens e aplicado a 142 estudantes universitários. Resultados: tanto a análise fatorial exploratória quanto a confirmatória desembocam em 3 dimensões: ambiente de sala de aula, processos de ensino-aprendizagem e avaliação. Os resultados obtidos tanto na confiabilidade (alfa de Cronbach 0,955) como na análise fatorial confirmatória (χ2/gl=1,944, CFI=0,97; GFI=0,78; RMR=0,077; RMSEA=0,08) produzem índices altamente satisfatórios. Conclusão: análises estatísticas mostram que este instrumento é válido, confiável e fácil de aplicar para os professores avaliarem a experiência estudantil de aprendizagem centrada no aluno

Practice frequency and reasons for participation in physical activities in gender and age function of 13-14 years old schoolchildren from Melilla

El presente artículo expone los resultados de un estudio dirigido a conocer la influencia del género y el curso en la frecuencia semanal y diaria de práctica de actividad fsica (AF), así conio en los motivos de práctica de AF que manifiestan escolares de 13- 14 años de Melilla. Los participantes han sido 548 escolares (267 chicos y 381 chicas) de los cursos, 1º y 2º (13 - 14 años) de cuatro centros de Educación Secundaria Obligatoria de Melilla. Los datos se han recogido a través del cuestionario de "Hábitos de participación en Actividades Físicas". Los resultados muestran la existencia de diferencias significativas en función del genero tanto en los niveles de participación como en la importancia que conceden a los motivos que le llevan a participar en AF y en virtud de la variable curso, siendo los alumnas de 2º las que presentan niveles más bajos de participación y menor valoración de los motivos principales para la participación en AF, resultados similares a los hallados en estudios anteriores en otros contextos nacionales e internacionales.This paper presents the results of a study to determine the influence of gender and grade on weekly and daily physical activity, as well as the reasons for physical activity to show students 13-14 years of Melilla. Participants were 548 students (267 boys and 281 girls) in grade 1st and 2nd (13 - 14 years) from four secondary schools in Melilla. Data were collected through the questionnaire of "Habits of participation in Physical Activity". The results show the significant differences by gender in both participation levels and the importance of the reasons that made you take part in physical and sports activities. Also found significant differences under variable grade, with the 2nd grade students who have lower levels of participation and lower valuation of the main reasons for participation in physical activities, results similar to those found in previus studies other national and international contexts.Universidad de Granada. Facultad de Educación y Humanidades (Campus de Melilla

A novel sensor-bridge-to-microcontroller interface

Sensor bridges are usually interfaced to microcontrollers by supplying the bridge with a voltage or current and digitizing the resulting voltage or current after being amplified and low-pass filtered. This paper proposes an alternative method to interface a sensor bridge to a microcontroller that does not need any active component between the bridge and the microcontroller The bridge is considered a network with three inputs and one output. The resistance of each input to the output depends on the measurand. Using each input in turn to charge a capacitor connected to the bridge output yields three different time intervals. For a full bridge (a sensor at each arm), the ratio between the difference between two time intervals and the third time interval yields the fractional resistance change. Two-point calibration reduces zero and gain errors attributable to the electrical parameters of the ports of the microcontroller. The absolute error for a 15 psi (103.4 kPa) pressure sensor with 5000 Ω arms and a full-scale output of 125 mV is below 0.05% of full scale, which is better than 1 LSB for an 11 bit ADCPeer Reviewe

Error analysis and reduction for a simple sensor-microcontroller interface

Error analysis of a resistive sensor-to-microcontroller interface based on pulse-width modulation and time–ratio measurement shows that internal input and output resistances in microcontroller digital ports produce zero, gain and nonlinearity errors. The time–ratio measurement technique cancels these errors when the sensor resistance equals the reference resistor and reduces errors around that point. We propose two simple methods of reducing those errors for sensors with a wide dynamic range. Both methods use time–ratio measurements. The first method uses several reference resistors covering the sensor resistance range; the second method uses two-point calibration. The second method is more efficient and yields errors that can be smaller than 0.5 Ω for a sensor resistance from about 600 Ω to 3550 Ω.Peer Reviewe

A novel sensor-bridge-to-microcontroller interface

Sensor bridges are usually interfaced to microcontrollers by supplying the bridge with a voltage or current and digitizing the resulting voltage or current after being amplified and low-pass filtered. This paper proposes an alternative method to interface a sensor bridge to a microcontroller that does not need any active component between the bridge and the microcontroller The bridge is considered a network with three inputs and one output. The resistance of each input to the output depends on the measurand. Using each input in turn to charge a capacitor connected to the bridge output yields three different time intervals. For a full bridge (a sensor at each arm), the ratio between the difference between two time intervals and the third time interval yields the fractional resistance change. Two-point calibration reduces zero and gain errors attributable to the electrical parameters of the ports of the microcontroller. The absolute error for a 15 psi (103.4 kPa) pressure sensor with 5000 Ω arms and a full-scale output of 125 mV is below 0.05% of full scale, which is better than 1 LSB for an 11 bit ADCPeer Reviewe