Modèle de diffusion

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Diffusion models are a key concept in ordinateur[2] vision, image generation, and natural language processing. They are tools used to perform tasks like image denoising, inpainting, super-resolution, and text generation. They can be trained to clean up images blurred by Gaussian noise. A few examples of these models include denoising diffusion probabilistic models and noise conditioned score networks. They also play a vital role in non-equilibrium thermodynamics, where they help sample from complex probability distributions. They are further enhanced by advanced techniques like variational inference[1] and stochastic gradient descent. In the field of natural language processing, they are used for text generation and summarization, learning the latent structure of text data to produce contextually relevant text. Research entities such as OpenAI[3] et Google[4] Imagen have developed various diffusion models for image and text generation tasks.

Définitions des termes
1. inference. Inference is a cognitive process that involves drawing conclusions from available evidence and reasoning. It's a fundamental component of critical thinking and problem-solving, playing a significant role in fields as diverse as scientific research, literature interpretation, and artificial intelligence. There are several types of inference, including deductive, inductive, abductive, statistical, and causal, each with its own unique approach and application. For instance, deductive inference is about deriving specific conclusions from general principles, while inductive inference forms general conclusions from specific observations. On the other hand, abductive inference is about making educated guesses based on available evidence, while statistical and causal inferences involve interpreting data to draw conclusions about a population or to determine cause-and-effect relationships. However, biases, preconceptions, and misinterpretations can influence the accuracy of inferences. Despite these challenges, inference remains an essential skill that can be improved through practice, critical thinking exercises, and engaging in diverse reading materials.
2. ordinateur. Un ordinateur est un appareil sophistiqué qui manipule des données ou des informations conformément à un ensemble d'instructions, appelées programmes. De par leur conception, les ordinateurs peuvent effectuer un large éventail de tâches, allant des simples calculs arithmétiques au traitement et à l'analyse de données complexes. Ils ont évolué au fil des ans, depuis les outils de comptage primitifs comme le boulier jusqu'aux machines numériques modernes. Le cœur d'un ordinateur est son unité centrale de traitement (UC), qui comprend une unité arithmétique et logique (UAL) pour effectuer les opérations mathématiques et des registres pour stocker les données. Les ordinateurs disposent également d'unités de mémoire, comme la ROM et la RAM, pour stocker les informations. Les autres composants comprennent des dispositifs d'entrée/sortie (E/S) qui permettent d'interagir avec la machine et des circuits intégrés qui améliorent la fonctionnalité de l'ordinateur. Des innovations historiques majeures, comme l'invention du premier ordinateur programmable par Charles Babbage et le développement du premier ordinateur numérique électronique automatique, l'ordinateur Atanasoff-Berry (ABC), ont grandement contribué à leur évolution. Aujourd'hui, les ordinateurs alimentent l'internet, relient des milliards d'utilisateurs dans le monde entier et sont devenus un outil essentiel dans presque tous les secteurs d'activité.

Au machine learning, diffusion modelségalement connu sous le nom de diffusion probabilistic models ou score-based generative models, are a class of latent variable generative models. A diffusion model consists of three major components: the forward process, the reverse process, and the sampling procedure. The goal of diffusion models is to learn a diffusion process that generates a probability distribution for a given dataset from which we can then sample new images. They learn the latent structure of a dataset by modeling the way in which data points diffuse through their latent space.

In the case of computer vision, diffusion models can be applied to a variety of tasks, including image denoising, inpainting, super-resolutionet image generation. This typically involves training a neural network to sequentially denoise images blurred with Gaussian noise. The model is trained to reverse the process of adding noise to an image. After training to convergence, it can be used for image generation by starting with an image composed of random noise for the network to iteratively denoise. Announced on 13 April 2022, OpenAI's text-to-image model DALL-E 2 is an example that uses diffusion models for both the model's prior (which produces an image embedding given a text caption) and the decoder that generates the final image. Diffusion models have recently found applications in natural language processing (NLP), particularly in areas like text generation and summarization.

Diffusion models are typically formulated as markov chains and trained using variational inference. Examples of generic diffusion modeling frameworks used in computer vision are denoising diffusion probabilistic models, noise conditioned score networks, and stochastic differential equations.

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