Difficulty Estimation With Action Scores for Computer Vision Tasks

As more machine learning models are now being applied in real world scenarios it has become crucial to evaluate their difficulties and biases. In this paper we present an unsupervised method for calculating a difficulty score based on the accumulated loss per epoch. Our proposed method does not require any modification to the model, neither any external supervision, and it can be easily applied to a wide range of machine learning tasks. We provide results for the tasks of image classification, image segmentation, and object detection. We compare our score against similar metrics and provide theoretical and empirical evidence of their difference. Furthermore, we show applications of our proposed score for detecting incorrect labels, and test for possible biases

Difficulty Estimation With Action Scores for Computer Vision Tasks

As more machine learning models are now being applied in real world scenarios it has become crucial to evaluate their difficulties and biases. In this paper we present an unsupervised method for calculating a difficulty score based on the accumulated loss per epoch. Our proposed method does not require any modification to the model, neither any external supervision, and it can be easily applied to a wide range of machine learning tasks. We provide results for the tasks of image classification, image segmentation, and object detection. We compare our score against similar metrics and provide theoretical and empirical evidence of their difference. Furthermore, we show applications of our proposed score for detecting incorrect labels, and test for possible biases

¿Por qué el acto del matar no cesa en su repetición? Un abordaje del asesinato como sostén de la cultura

El presente trabajo se inscribe en lo que concierne a la tendencia del humano hacia la repetición de un acto que se muestra como atroz, pero al tiempo imposible de eludir o eliminar en toda organización social: el asesinato. Acto que logramos reconocer desde los inicios siempre míticos de la cultura. De esta forma, y de la mano de las elaboraciones psicoanalíticas inauguradas por Freud y repensadas por Lacan, se trabaja en torno al asesinato con la intención de darle algo de sentido y, tal vez, poder ubicar su lugar en el drama humano.Abstract. The present work is about the tendency of the human been to repeat an outrageous, but impossible to eliminate act, in all social organization: the murder. With the psychoanalytic work, inaugurated by Freud and rethought by Lacan, this thesis work around the murder with the intention to give it some sense and, perhaps, to be able to locate its place in the human drama.Maestrí

Nonlinear optics Pulse propagation in fiber optics filled with gases, liquids, and organic dyes.

The characterization of nonlinear optical material properties, such as nonlinear refractive index and nonlinear absorption coefficient, is one of the most important subjects in nonlinear optics due to its application in many fields such as spectroscopy, material processing, biophysics, atmospheric sensing and metrology, among others. Besides the possibility of creating new technology. In this thesis, the Z-scan technique was implemented and calibrated. It remains one of the most widely used techniques to obtain both nonlinear refractive index and the absorption coefficient of a material. Moreover, nonlinear phenomena inside optical fiber is well known due to their applications and advantages like the low input energy required to generate supercontinuum, four wave mixing, dispersive wave, among others. In this work, several simulations were performed with new fiber geometries, material responses and different noble gases infiltrated in fiber. Different simulation regimes were considered as well by varying input power, pulse width and pressure. Nonlinear parameters for organic dyes, multi-walled carbon nanotubes, and CS2 were reported, pointing out the main reasons behind each result and addressing possible new phenomena involved. The nonlinear output response in both time and frequency domains was reported for several simulations, obtaining the nonlinear pulse output for the new CS2 response function. A novel consideration was proposed in which the final pulse depends on the propagation distance for non-instantaneous materials and the nonlinear constant (γ) must be recalculated at each step. It was demonstrated how the output pulse can be controlled by changing the fiber length. Among the most important results, it was found there exists a possibility to change between modulation instability and four wave mixing by only varying the propagation distance. Finally, it was also found that a special type of fiber, namely negative curvature hollow core fiber, can be used to obtain a broad band spectrum when it is filled with noble gases and they can be tuned with pressure from linear behavior up to a super critical zone.Resumen: a caracterización de propiedades ´ópticas no lineales, como lo son el ´índice de refracción y el coeficiente de absorción no lineal, es uno de los temas más importantes en ´óptica no lineal debido a su aplicación en muchos campos como la espectroscopia, procesamiento de materiales, biofísica, sensado atmosférico, metrología, entre otros. Además de la posibilidad de creación de nueva tecnología. En esta tesis se implemento y calibro la técnica Z-Scan, una de las técnicas más utilizadas para obtener tanto el ´índice de refracción no lineal como el coeficiente de absorción de un material. Asimismo, los fenómenos no lineales dentro de la fibra ´óptica son bien conocidos debido a sus aplicaciones y ventajas tales como la baja energía de entrada requerida para generar fenómenos de supercontinuo, mezclado de cuatro ondas y ondas dispersivas. En este trabajo se realizaron varias simulaciones con nuevas geometrías de fibras, respuestas de material y gases nobles dentro de la fibra. Se consideraron diferentes regímenes de potencia de entrada, ancho de pulso y presión. Se reportaron los parámetros no lineales para las sustancias orgánicas usadas, nanotubos de carbono de paredes múltiples y CS2, indicando la razón principal detrás de cada resultado y abordando los posibles nuevos fenómenos involucrados. La respuesta de salida no lineal tanto en el dominio del tiempo como en el de frecuencia se reportó en varias simulaciones, obteniendo el pulso no lineal de salida para la nueva función de respuesta del CS2, se propuso una nueva consideración donde el pulso final depende de la distancia de propagación para materiales no instantáneos y la constante no lineal (γ) se deben recalcular en cada paso. Se demostró como se puede controlar el pulso de salida cambiando la longitud de la fibra; entre los resultados más importantes se encontró la posibilidad de cambiar entre la inestabilidad de la modulación y el mezclado de cuatro ondas solo variando la distancia de propagación. Finalmente, se encontró que un tipo especial de fibra, a saber, la fibra de núcleo hueco de curvatura negativa, se puede usar para obtener un amplio espectro de banda cuando se llena con gases nobles y se sintoniza con la presión, desde el comportamiento lineal hasta la zona supercríticaMaestrí

Waving Goodbye to Low-Res: A Diffusion-Wavelet Approach for Image Super-Resolution

This paper presents a novel Diffusion-Wavelet (DiWa) approach for Single-Image Super-Resolution (SISR). It leverages the strengths of Denoising Diffusion Probabilistic Models (DDPMs) and Discrete Wavelet Transformation (DWT). By enabling DDPMs to operate in the DWT domain, our DDPM models effectively hallucinate high-frequency information for super-resolved images on the wavelet spectrum, resulting in high-quality and detailed reconstructions in image space. Quantitatively, we outperform state-of-the-art diffusion-based SISR methods, namely SR3 and SRDiff, regarding PSNR, SSIM, and LPIPS on both face (8x scaling) and general (4x scaling) SR benchmarks. Meanwhile, using DWT enabled us to use fewer parameters than the compared models: 92M parameters instead of 550M compared to SR3 and 9.3M instead of 12M compared to SRDiff. Additionally, our method outperforms other state-of-the-art generative methods on classical general SR datasets while saving inference time. Finally, our work highlights its potential for various applications