Blind Source Separation with Optimal Transport Non-negative Matrix Factorization

Optimal transport as a loss for machine learning optimization problems has recently gained a lot of attention. Building upon recent advances in computational optimal transport, we develop an optimal transport non-negative matrix factorization (NMF) algorithm for supervised speech blind source separation (BSS). Optimal transport allows us to design and leverage a cost between short-time Fourier transform (STFT) spectrogram frequencies, which takes into account how humans perceive sound. We give empirical evidence that using our proposed optimal transport NMF leads to perceptually better results than Euclidean NMF, for both isolated voice reconstruction and BSS tasks. Finally, we demonstrate how to use optimal transport for cross domain sound processing tasks, where frequencies represented in the input spectrograms may be different from one spectrogram to another.Comment: 22 pages, 7 figures, 2 additional file

最適輸送辞書学習と非負値行列因子分解

京都大学新制・課程博士博士(情報学)甲第23314号情博第750号新制||情||128(附属図書館)京都大学大学院情報学研究科知能情報学専攻(主査)教授 山本 章博, 教授 鹿島 久嗣, 教授 河原 達也学位規則第4条第1項該当Doctor of InformaticsKyoto UniversityDFA

Bandit-based Estimation of Distribution Algorithms for Noisy Optimization: Rigorous Runtime Analysis

International audienceWe show complexity bounds for noisy optimization, in frame- works in which noise is stronger than in previously published papers[19]. We also propose an algorithm based on bandits (variants of [16]) that reaches the bound within logarithmic factors. We emphasize the differ- ences with empirical derived published algorithms

Tchekhov et son temps

Dans les dernières années de sa vie, Tchekhov a été l'objet d'un respect, d'une admiration unanimes en Russie.Cette reconnaissance allait même trop loin, au gré de certains de ses contemporains. Elle contenait une bonne dose d'hypocrisie. Ainsi, lors des funérailles de Tchekhov, un auteur tel que L. Andreïev avait été révolté par la tentative éhontée de récupération de la personne et de l'œuvre de Tchekhov par les représentants de l'esprit petit-bourgeois. Cette unanimité (entendons-nous, ell..

Handling Expensive Optimization with Large Noise

International audienceThis paper exhibits lower and upper bounds on runtimes for expensive noisy optimization problems. Runtimes are expressed in terms of number of fitness evaluations. Fitnesses considered are monotonic transformations of the {\em sphere} function. The analysis focuses on the common case of fitness functions quadratic in the distance to the optimum in the neighborhood of this optimum---it is nonetheless also valid for any monotonic polynomial of degree p>2. Upper bounds are derived via a bandit-based estimation of distribution algorithm that relies on Bernstein races called R-EDA. It is known that the algorithm is consistent even in non-differentiable cases. Here we show that: (i) if the variance of the noise decreases to 0 around the optimum, it can perform optimally for quadratic transformations of the norm to the optimum, (ii) otherwise, it provides a slower convergence rate than the one exhibited empirically by an algorithm called Quadratic Logistic Regression based on surrogate models---although QLR requires a probabilistic prior on the fitness class

Origin and evolutionary plasticity of the gastric caecum in sea urchins (Echinodermata: Echinoidea)

Background: The digestive tract of many metazoan invertebrates is characterized by the presence of caeca or diverticula that serve secretory and/or absorptive functions. With the development of various feeding habits, distinctive digestive organs may be present in certain taxa. This also holds true for sea urchins (Echinodermata: Echinoidea), in which a highly specialized gastric caecum can be found in members of a derived subgroup, the Irregularia (cake urchins, sea biscuits, sand dollars, heart urchins, and related forms). As such a specialized caecum has not been reported from "regular" sea urchin taxa, the aim of this study was to elucidate its evolutionary origin. Results: Using morphological data derived from dissection, magnetic resonance imaging, and extensive literature studies, we compare the digestive tract of 168 echinoid species belonging to 51 extant families. Based on a number of characters such as topography, general morphology, mesenterial suspension, and integration into the haemal system, we homologize the gastric caecum with the more or less pronounced dilation of the anterior stomach that is observed in most "regular" sea urchin taxa. In the Irregularia, a gastric caecum can be found in all taxa except in the Laganina and Scutellina. It is also undeveloped in certain spatangoid species. Conclusions: According to our findings, the sea urchin gastric caecum most likely constitutes a synapomorphy of the Euechinoidea. Its occurrence in "regular" euechinoids is linked to the presence of an additional festoon of the anterior stomach in ambulacrum III. Both structures, the additional festoon and the gastric caecum, are absent in the sister taxon to the Euechinoidea, the Cidaroida. Since the degree of specialization of the gastric caecum is most pronounced in the predominantly sediment-burrowing irregular taxa, we hypothesize that its evolution is closely linked to the development of more elaborate infaunal lifestyles. We provide a comprehensive study of the origin and evolutionary plasticity of a conspicuous digestive tract structure, the gastric caecum, in a major taxon of the extant invertebrate macrozoobenthos. © 2010 Ziegler et al; licensee BioMed Central Ltd.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Le Théâtre de Tchekhov

Dans l'itinéraire artistique de Tchekhov, les grandes pièces sont tardives : la première, La Mouette, est de 1896. J'appelle « grandes pièces » les quatre dernières œuvres théâtrales de notre auteur, c'est-à-dire La Mouette, Oncle Vania, Les Trois Sœurs, et La Cerisaie. Selon certains spécialistes russes, il est légitime de considérer que ces quatre pièces constituent à elles seules « le » théâtre de Tchekhov : les autres titres, Platonov ou Ivanov, les petites pièces en un acte ne représente..

Ben-Tovit de Leonid Andreev (1905) : un calvaire à la Nietzsche

Article Introduction Dans la culture russe des années 1890-1910, la référence, explicite ou non, à Friedrich Nietzsche est omniprésente. En Russie comme ailleurs en Europe à cette époque, les courants intellectuels, artistiques et littéraires les plus divers sont requis par la parole du philosophe. À la faveur de traductions précoces et de commentaires remarqués, sa pensée donne lieu en Russie à une floraison de thèmes (le renversement des valeurs), de figures (le surhomme), de postures (une ..

Pilot, Rollout and Monte Carlo Tree Search Methods for Job Shop Scheduling

Greedy heuristics may be attuned by looking ahead for each possible choice, in an approach called the rollout or Pilot method. These methods may be seen as meta-heuristics that can enhance (any) heuristic solution, by repetitively modifying a master solution: similarly to what is done in game tree search, better choices are identified using lookahead, based on solutions obtained by repeatedly using a greedy heuristic. This paper first illustrates how the Pilot method improves upon some simple well known dispatch heuristics for the job-shop scheduling problem. The Pilot method is then shown to be a special case of the more recent Monte Carlo Tree Search (MCTS) methods: Unlike the Pilot method, MCTS methods use random completion of partial solutions to identify promising branches of the tree. The Pilot method and a simple version of MCTS, using the $\varepsilon$-greedy exploration paradigms, are then compared within the same framework, consisting of 300 scheduling problems of varying sizes with fixed-budget of rollouts. Results demonstrate that MCTS reaches better or same results as the Pilot methods in this context.Comment: Learning and Intelligent OptimizatioN (LION'6) 7219 (2012