Neural Steerer: Novel Steering Vector Synthesis with a Causal Neural Field over Frequency and Source Positions

Neural fields have successfully been used in many research fields for their native ability to estimate a continuous function from a finite number of observations. In audio processing, this technique has been applied to acoustic and head-related transfer function interpolation. However, most of the existing methods estimate the real-valued magnitude function over a predefined discrete set of frequencies. In this study, we propose a novel approach for steering vector interpolation that regards frequencies as continuous input variables. Moreover, we propose a novel unsupervised regularization term enforcing the estimated filters to be causal. The experiment using real steering vectors show that the proposed frequency resolution-free method outperformed the existing methods operating over discrete set of frequencies.Comment: Correction in the model (2

Contre la raison? : l'opposition au rationalisme dans le discours de l'écologisme fondamentaliste

Le but du présent mémoire se divise essentiellement en deux objectifs. Le premier de ceux-ci consiste à repérer, dans le discours de l'écologisme fondamentaliste, l'opposition au rationalisme moderne. Ce premier objectif est cependant secondaire puisque son utilité réside dans l'atteinte du second objectif. Ce dernier consiste effectivement, quant à lui, à établir une critique de cette opposition qui aura été rendue manifeste au lecteur avec l'atteinte du premier objectif. Nous nous limiterons, pour ce faire, à employer les grilles d'analyse du rationalisme fournies par des auteurs du courant écologiste fondamentaliste afin de les confronter à celles fournies par des auteurs qui se penchent plutôt directement sur la critique du rationalisme, c'est-à-dire qui n'ont pas l'écologisme comme point de départ. Le lecteur comprendra que le travail qui suit s'appuie sur une démarche analytique pour parvenir à son but. Quatre sujets généraux sont abordés par cette démarche : la critique du rationalisme, les impacts environnementaux du rationalisme selon le discours écologiste fondamentaliste, la légitimation rationnelle à l'intérieur du discours écologiste fondamentaliste et le recours à la pensée mythique dans le discours écologiste fondamentaliste. L'hypothèse principale de ce mémoire est que l'opposition au rationalisme dans l'écologisme fondamentaliste ne tient pas la route puisque ce discours s'appuie essentiellement sur une approche rationaliste de la réalité, même dans ses exemples les plus radicaux

Analyse de spectres dans l'ultraviolet lointain d'étoiles sous-naines chaudes à atmosphère riche en hydrogène

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal

Homogeneous asymmetric transfer hydrogenation of ketones using a ruthenium catalyst anchored on chitosan : natural chirality at work

A pivaloyl functionalized chitosan biopolymer was used as a polyligand for the [Ru(p-cymene)Cl2] moiety. The functionalized biopolymer containing a metal to saccharide ratio of 0.33 was used as a catalyst for the asymmetric transfer hydrogenation of ketones. The reactions gave yields up to 80% and enantiomeric excesses up to 72%, with the intrinsic chirality of chitosan being the only source of enantioselection

Geometric Modelling and Deformation for Shape Optimization of Ship Hulls and Appendages

International audienceThe precise control of geometric models plays an important role in many domains such as computer-aided geometric design and numerical simulation. For shape optimization in computational fluid dynamics (CFD), the choice of control parameters and the way to deform a shape are critical.In this article, we describe a skeleton-based representation of shapes adapted for CFD simulation and automatic shape optimization. Instead of using the control points of a classic B-spline representation, we control the geometry in terms of architectural parameters. We assure valid shapeswith a strong shape consistency control. Deformations of the geometry are performed by solving optimization problems on the skeleton. Finally, a surface reconstruction method is proposed to evaluate the shape's performances with CFD solvers. We illustrate the approach on two problems: thefoil of an AC45 racing sail boat and the bulbous bow of a fishing trawler. For each case, we obtained a set of shape deformations and then we evaluated and analyzed the performances of the different shapes with CFD computations

Forestry plantations as a pathway for invasive alien plants in the National Park at Réunion island

Identifying pathways of introduction remains a major priority to prevent future plant invasions into natural areas. In this study, we assessed whether forestry plantations favor alien plant dissemination into the National Park of Reunion. Results showed significant decrease in the percentage of alien plant biomass from the forestry plantations to the undisturbed areas. At one site, a significant difference was also found for the mean alien species number and the mean alien plant abundance. In both sites, numerous alien species were present in the understorey of Cryptomeria plantations only, with some already escaping and occurring at the entrance of the National Park. This study recommends strengthening early detection and rapid response of alien plants and suggests alternative management approaches in forestry plantations, including the use of community-based restoration programmes.Une des priorités pour contrôler les futures invasions floristiques est d’identifier les voies d’introduction aux abords des aires naturelles. Dans cette étude, nous avons testé si les forêts cultivées peuvent favoriser l’envahissement par les plantes exotiques à l’intérieur du Parc national de la Réunion. Les résultats montrent une diminution significative du pourcentage de la biomasse végétale des plantes exotiques des forêts cultivées vers le milieu naturel. Les différences sont également significatives au niveau d’un des deux sites étudiés concernant les moyennes du nombre de plantes exotiques et de la somme de l’abondance des plantes. Dans les deux cas, de nombreuses espèces sont présentes seulement en sous-bois de forêts cultivées ou également à l’entrée du Parc national. Cette étude préconise de renforcer les actions de détection précoce et de réponse rapide. Les auteurs proposent également la mise en place de méthodes de gestion alternatives de ces habitats incluant une approche participative de la population dans des programmes de restauration

Forestry plantations as a pathway for invasive alien plants in the National Park at Réunion island

Identifying pathways of introduction remains a major priority to prevent future plant invasions into natural areas. In this study, we assessed whether forestry plantations favor alien plant dissemination into the National Park of Reunion. Results showed significant decrease in the percentage of alien plant biomass from the forestry plantations to the undisturbed areas. At one site, a significant difference was also found for the mean alien species number and the mean alien plant abundance. In both sites, numerous alien species were present in the understorey of Cryptomeria plantations only, with some already escaping and occurring at the entrance of the National Park. This study recommends strengthening early detection and rapid response of alien plants and suggests alternative management approaches in forestry plantations, including the use of community-based restoration programmes.Une des priorités pour contrôler les futures invasions floristiques est d’identifier les voies d’introduction aux abords des aires naturelles. Dans cette étude, nous avons testé si les forêts cultivées peuvent favoriser l’envahissement par les plantes exotiques à l’intérieur du Parc national de la Réunion. Les résultats montrent une diminution significative du pourcentage de la biomasse végétale des plantes exotiques des forêts cultivées vers le milieu naturel. Les différences sont également significatives au niveau d’un des deux sites étudiés concernant les moyennes du nombre de plantes exotiques et de la somme de l’abondance des plantes. Dans les deux cas, de nombreuses espèces sont présentes seulement en sous-bois de forêts cultivées ou également à l’entrée du Parc national. Cette étude préconise de renforcer les actions de détection précoce et de réponse rapide. Les auteurs proposent également la mise en place de méthodes de gestion alternatives de ces habitats incluant une approche participative de la population dans des programmes de restauration

DNN-Free Low-Latency Adaptive Speech Enhancement Based on Frame-Online Beamforming Powered by Block-Online FastMNMF

This paper describes a practical dual-process speech enhancement system that adapts environment-sensitive frame-online beamforming (front-end) with help from environment-free block-online source separation (back-end). To use minimum variance distortionless response (MVDR) beamforming, one may train a deep neural network (DNN) that estimates time-frequency masks used for computing the covariance matrices of sources (speech and noise). Backpropagation-based run-time adaptation of the DNN was proposed for dealing with the mismatched training-test conditions. Instead, one may try to directly estimate the source covariance matrices with a state-of-the-art blind source separation method called fast multichannel non-negative matrix factorization (FastMNMF). In practice, however, neither the DNN nor the FastMNMF can be updated in a frame-online manner due to its computationally-expensive iterative nature. Our DNN-free system leverages the posteriors of the latest source spectrograms given by block-online FastMNMF to derive the current source covariance matrices for frame-online beamforming. The evaluation shows that our frame-online system can quickly respond to scene changes caused by interfering speaker movements and outperformed an existing block-online system with DNN-based beamforming by 5.0 points in terms of the word error rate.Comment: IWAENC 202

Direction-Aware Joint Adaptation of Neural Speech Enhancement and Recognition in Real Multiparty Conversational Environments

This paper describes noisy speech recognition for an augmented reality headset that helps verbal communication within real multiparty conversational environments. A major approach that has actively been studied in simulated environments is to sequentially perform speech enhancement and automatic speech recognition (ASR) based on deep neural networks (DNNs) trained in a supervised manner. In our task, however, such a pretrained system fails to work due to the mismatch between the training and test conditions and the head movements of the user. To enhance only the utterances of a target speaker, we use beamforming based on a DNN-based speech mask estimator that can adaptively extract the speech components corresponding to a head-relative particular direction. We propose a semi-supervised adaptation method that jointly updates the mask estimator and the ASR model at run-time using clean speech signals with ground-truth transcriptions and noisy speech signals with highly-confident estimated transcriptions. Comparative experiments using the state-of-the-art distant speech recognition system show that the proposed method significantly improves the ASR performance.Comment: INTERSPEECH 202