Curse of dimensionality
The curse of dimensionality refers to various phenomena that arise when analyzing and organizing data in high-dimensional spaces (often with hundreds or thousands of dimensions) that do not occur in low-dimensional settings such as the three-dimensional physical space of everyday experience. The term curse of dimensionality was coined by Richard E. Bellman when considering problems in dynamic optimization.[1][2] The "curse of dimensionality" depends on the algorithm[edit] The "curse of dimensionality" is not a problem of high-dimensional data, but a joint problem of the data and the algorithm being applied. It arises when the algorithm does not scale well to high-dimensional data, typically due to needing an amount of time or memory that is exponential in the number of dimensions of the data. When facing the curse of dimensionality, a good solution can often be found by changing the algorithm, or by pre-processing the data into a lower-dimensional form. Combinatorics[edit] Sampling[edit] .
The quilted universe
Eternal return
Eternal return (also known as "eternal recurrence") is a concept that the universe has been recurring, and will continue to recur, in a self-similar form an infinite number of times across infinite time or space. The concept is found in Indian philosophy and in ancient Egypt and was subsequently taken up by the Pythagoreans and Stoics. With the decline of antiquity and the spread of Christianity, the concept fell into disuse in the Western world, with the exception of Friedrich Nietzsche, who connected the thought to many of his other concepts, including amor fati. In addition, the philosophical concept of eternal recurrence was addressed by Arthur Schopenhauer. It is a purely physical concept, involving no supernatural reincarnation, but the return of beings in the same bodies. Premise[edit] The basic premise proceeds from the assumption that the probability of a world coming into existence exactly like our own is greater than zero (we know this because our world exists). Judaism[edit]
Créer sa réalité augmentée avec l’application Aurasma
La réalité augmentée (ou RA) est la technologie qui permet d’ajouter des éléments virtuels (texte, image, vidéo, animation, son, sensation tactile…) à notre environnement proche. Aurasma, c’est tout d’abord une application mobile permettant de « lire » la réalité augmentée réalisée spécifiquement pour cette application. Elle permet également de créer sa propre réalité augmentée. En effet, on peut facilement, depuis son smartphone ou de sa tablette, incruster une image ou une vidéo sur un élément du réel. Liens de téléchargement d’Aurasma Un peu de vocabulaire : Avec l’application Aurasma, on peut créer, partager et lire des Auras. L’élément déclencheur ou Trigger image c’est ce qui est reconnu par Aurasma pour déclencher l’incrustation de l’élément virtuel ou Overlay [1]. Il est possible de créer des canaux ou channels dans lesquels seront ajoutées les Auras. Pour bien commencer : Pour créer une Aura il n’est pas utile d’autoriser l’accès de l’application au service de géolocalisation.
Level IV: Ultimate ensemble
Closed timelike curve
In mathematical physics, a closed timelike curve (CTC) is a world line in a Lorentzian manifold, of a material particle in spacetime that is "closed", returning to its starting point. This possibility was first raised[citation needed] by Kurt Gödel in 1949, who discovered a solution to the equations of general relativity (GR) allowing CTCs known as the Gödel metric; and since then other GR solutions containing CTCs have been found, such as the Tipler cylinder and traversable wormholes. If CTCs exist, their existence would seem to imply at least the theoretical possibility of time travel backwards in time, raising the spectre of the grandfather paradox, although the Novikov self-consistency principle seems to show that such paradoxes could be avoided. Some physicists speculate that the CTCs which appear in certain GR solutions might be ruled out by a future theory of quantum gravity which would replace GR, an idea which Stephen Hawking has labeled the chronology protection conjecture.
De la carte heuristique à l'ordonnancement des tâches
A. La carte heuristique dans le cadre d’un projet 1. La cartographie mentale d’idées Nous baserons notre exemple sur l’organisation d’une course d’orientation. Projet confié à un groupe d’élèves, avec un cahier des charges qui n’est pas présenté dans cet article. Lorsque l’on débute un projet il y a un échange d’idées qui se fait sur tous les points à aborder durant le projet. Lancement de MindView Dès le lancement vous pouvez immédiatement démarrer un projet, partir d’un modèle ou utiliser un fichier existant. Depuis le menu FICHIER ces mêmes éléments sont accessibles et permettent également de choisir les différents mode de présentation de votre carte heuristique : Comme tous les logiciels de mind mapping la présentation débute par un sujet central : Il faut noter que votre choix initial de présentation est réversible à tout moment et que vous pouvez passer d’un mode de présentation à un autre suivant le type de sujet traité ou pour avoir un autre visuel. 2. Élaboration de la carte mentale.
Level II: Universes with different physical constants
Hylomorphism
Hylomorphism is a philosophical theory developed by Aristotle, which conceives being (ousia) as a compound of matter and form. The word "hylomorphism" is a 19th-century term formed from the Greek words ὕλη hyle, "wood, matter" and μορφή, morphē, "form." Matter and form[edit] Aristotle defines X's matter as "that out of which" X is made.[1] For example, letters are the matter of syllables.[2] Thus, "matter" is a relative term:[3] an object counts as matter relative to something else. Change is analyzed as a material transformation: matter is what undergoes a change of form.[4] For example, consider a lump of bronze that's shaped into a statue. According to Aristotle's theory of perception, we perceive an object by receiving its form with our sense organs.[7] Thus, forms include complex qualia such as colors, textures, and flavors, not just shapes.[8] Substantial form, accidental form, and prime matter[edit] In some cases, a substance's matter will itself be a substance. Basic theory[edit]
