Nivel de satisfacción sobre estrategias de enseñanza - aprendizaje de los alumnos del octavo ciclo de la escuela profesional de Estomatología de la universidad Señor de Sipán – Perú, 2014

Las estrategias didácticas facilitan el proceso de enseñanza - aprendizaje de los cursos, sin embargo utilizadas de manera inadecuada causan un bajo rendimiento académico que repercute en la calidad académica de los estudiantes. El objetivo fue determinar el nivel de satisfacción sobre estrategias de enseñanza - aprendizaje en los estudiantes del octavo ciclo en la Escuela Profesional de Estomatología de la Universidad Señor de Sipán durante el semestre académico, 2014-II. El tipo de investigación fue descriptiva, de corte transversal, la muestra estuvo conformada por 48 estudiantes quienes evaluaron cinco cursos en función a las estrategias didácticas que los docentes utilizaron en el proceso de enseñanza-aprendizaje. La evaluación consistió en la utilización de las siguientes estrategias didácticas: clases magistrales, aprendizaje autónomo, trabajo en equipo, exposición de temas asignados, práctica dirigida, revisión bibliográfica, método de casos y el aprendizaje basado en problemas. Para la medición del nivel de dichas estrategias se utilizó la Escala de Likert. Resultado de la investigación: El nivel de satisfacción sobre estrategias de enseñanza - aprendizaje según la escala de Likert, se obtuvo como resultado 3 que lo ubica en el nivel de ni satisfecho ni insatisfecho.Tesi

Protecting fiber-optic links from third party intrusion using distributed acoustic sensors

19th International Conference on Transparent Optical Networks, 02/07/2017-06/07/2017, Girona, España.European CommissionMinisterio de Economía y CompetitividadComunidad de Madri

> 10 dB SNR Enhancement in Distributed Acoustic Sensors through First Order Phase Noise Cancellation

The Optical Networking and Communication Conference & Exhibition, 11/03/2018-15/03/2018, San Diego, Estados Unidos.The performance of Rayleigh-based distributed acoustic sensors (DAS) is strongly dependent on the coherence of the laser source. We present a simple methodology to reduce the impact of the laser phase noise in chirped-pulse DAS.European CommissionMinisterio de Economía y Competitivida

Laser Phase-noise Cancellation in Chirped-pulse Distributed Acoustic Sensors

European CommissionMinisterio de Economía y CompetitividadComunidad de Madri

Chirped-pulse phase-sensitive reflectometry

X Reunión Española de Optoelectrónica (OPTOEL17), 12/07/2017-14/07/2017, Santiago de Compostela, España.In this work, a new distributed fiber sensor named chirped-pulse phase-sensitive OTDR is presented. It is based on a phase-sensitive OTDR using direct detection and linearly chirped pulses. The new sensor allows the dynamic and quantitative measurement of temperature/strain changes, with mK/nå resolution. The technique does not require a frequency sweep or coherent detection. It is presented the fundamentals of the sensor and measurements of temperature, vibrations and music.European CommissionMinisterio de Economía y CompetitividadComunidad de Madri

Chirped-pulse Phase-sensitive Reflectometer Assisted by First Order Raman Amplification

The use of linearly chirped probe pulses in phase sensitive-(Phi)OTDR technology has been recently demonstrated to allow for high-resolution, quantitative and dynamic temperature or strain variation measurements in a simple and very robust manner. This new sensing technology, known as chirped-pulse PhiOTDR, had a maximum reported sensing range of 11 km. In this paper, a 75 km sensing range with 10 m spatial resolution is demonstrated by using bidirectional first order Raman amplification. The system is capable of performing truly linear, single-shot measurements of strain perturbations with an update rate of 1 kHz and 1 nepsilon resolution. The time-domain trace of the sensor exhibits a signal to noise ratio (SNR) in the worst point of >3 dB, allowing to monitor vibrations up to 500 Hz with remarkable accuracy. To demonstrate the capabilities of the proposed system, we apply 20 dB (with only 300 ms analysis window and no post-processing) and no evidence of nonlinearity in the acoustic response. The optical nonlinear effects that the probe pulse could suffer along the sensing fiber are thoroughly studied, paying special attention to potential distortions of the pulse shape, particularly in its instantaneous frequency profile. Our analysis reveals that, for proper values of peak power, the pulse does not suffer any major distortion and therefore the system performance is not compromised.European CommissionMinisterio de Economía y CompetitividadComunidad de Madri

Chirped-pulse Phase-sensitive Optical Time Domain Reflectometry

Asia Communications and Photonics Conference, 02/11/2016-05/11/2016, Wuhan, China.European CommissionMinisterio de Economía y CompetitividadComunidad de Madri

Steady-Sensitivity Distributed Acoustic Sensors

Distributed acoustic sensors (DAS) based on phase-sensitive optical time-domain reflectometry (phiOTDR) have demonstrated interesting performance for many applications ranging from seismology to pipeline protection. However, the sensitivity of traditional DAS relying on coherent detection is strongly dependent on the system noise and trace fading points, offering poor reliability of the results in the spatial dimension. In this manuscript, we evaluate the statistical performance of a recently proposed DAS technique, namely, chirped-pulse phiOTDR, in terms of sensitivity and signal-to-noise ratio (SNR). Our results show behavioral trends that significantly differ from those of traditional DAS. In particular, the acoustic SNR distribution in chirped-pulse DAS is notably narrower than that in the traditional case, allowing to ensure a large system dynamic range across all the points of the optical trace. Hence, chirped-pulse phiOTDR offers localized perturbation detection with very high reliability, almost independent of trace fading points, along the complete reachable range of the sensor.European CommissionMinisterio de Economía y CompetitividadComunidad de Madri

Extending the Measurement of True Dynamic Strain via Chirped-Pulse Phase-Sensitive Optical Time Domain Reflectometry to 100's of Microstrains

26ª edición del congreso internacional Optical Fiber Sensors (OFS26), 24/09/2018-28/09/2018, Lausanne, Suiza.It is experimentally demonstrated that a chirped pulse phase-sensitive OTDR can measure large and fast dynamic strains (~100’s of µε, ~100’s of Hz) with SNR of ≥ 24dB. Signal smoothing and impact of error accumulation are also discussed.European Commissio

Time-expanded phase-sensitive optical time-domain reflectometry

Phase-sensitive optical time-domain reflectometry (ΦOTDR) is a well-established technique that provides spatio-temporal measurements of an environmental variable in real time. This unique capability is being leveraged in an ever-increasing number of applications, from energy transportation or civil security to seismology. To date, a wide number of different approaches have been implemented, providing a plethora of options in terms of performance (resolution, acquisition bandwidth, sensitivity or range). However, to achieve high spatial resolutions, detection bandwidths in the GHz range are typically required, substantially increasing the system cost and complexity. Here, we present a novel ΦOTDR approach that allows a customized time expansion of the received optical traces. Hence, the presented technique reaches cm-scale spatial resolutions over 1 km while requiring a remarkably low detection bandwidth in the MHz regime. This approach relies on the use of dual-comb spectrometry to interrogate the fibre and sample the backscattered light. Random phase-spectral coding is applied to the employed combs to maximize the signal-to-noise ratio of the sensing scheme. A comparison of the proposed method with alternative approaches aimed at similar operation features is provided, along with a thorough analysis of the new trade-offs. Our results demonstrate a radically novel high-resolution ΦOTDR scheme, which could promote new applications in metrology, borehole monitoring or aerospace