Training Deep Learning Algorithms on Synthetic Forest Images for Tree Detection

Vision-based segmentation in forested environments is a key functionality for autonomous forestry operations such as tree felling and forwarding. Deep learning algorithms demonstrate promising results to perform visual tasks such as object detection. However, the supervised learning process of these algorithms requires annotations from a large diversity of images. In this work, we propose to use simulated forest environments to automatically generate 43 k realistic synthetic images with pixel-level annotations, and use it to train deep learning algorithms for tree detection. This allows us to address the following questions: i) what kind of performance should we expect from deep learning in harsh synthetic forest environments, ii) which annotations are the most important for training, and iii) what modality should be used between RGB and depth. We also report the promising transfer learning capability of features learned on our synthetic dataset by directly predicting bounding box, segmentation masks and keypoints on real images. Code available on GitHub (https://github.com/norlab-ulaval/PercepTreeV1).Comment: Work presented at ICRA 2022 Workshop in Innovation in Forestry Robotics: Research and Industry Adoptio

De la volonté de connaître au maintien de soi : la caractérisation husserlienne de l'être de l'intentionnel dans Expérience et jugement

Mémoire numérisé par la Division de la gestion de documents et des archives de l'Université de Montréal

La réflexion phénoménologique au crible de la grammaire : la question de l’expression de la vie intérieure de la conscience chez Husserl et Wittgenstein

Cotutelle avec l'Université Panthéon Sorbonne - Paris IBien que Wittgenstein ait toujours douté de l’intérêt philosophique de ce genre de constat historique, il est généralement admis que l’auteur des Recherches philosophiques est l’inventeur d’une critique dévastatrice du «mythe de l’intériorité », qui représente l’une des tentations les plus constantes de la philosophie moderne. À l’encontre des pensées de la réflexion qui assignent pour tâche à la philosophie de clarifier la signification des concepts obscurs de notre langage (vérité, signification, pensée, etc.) en portant une attention réflexive à nos états mentaux (Locke et James sont de bons exemples de ce paradigme), Wittgenstein a montré qu’une telle entreprise philosophique repose sur une profonde incompréhension du fonctionnement du langage ordinaire et de sa grammaire. Wittgenstein n’est pas le premier à se lancer dans une initiative du genre, mais les moyens utilisés pour s’en acquitter expliquent la place qu’il a occupée dans les débats que n’a cessé de susciter la question de l’intériorité tout au long du vingtième siècle : on ne peut croire à la valeur d’un recours à l’introspection en philosophie qu’en se méprenant profondément sur la nature et le fonctionnement du langage nous permettant d’exprimer notre vie mentale. Étant donné que la phénoménologie husserlienne se propose de résoudre les problèmes philosophiques en adoptant pour méthode la réflexion et la description de l’expérience vécue, il est très tentant de voir en Husserl un héritier de cette tradition philosophique qui se trouve ruinée par les arguments de Wittgenstein. En partant du présupposé que la déconstruction du «mythe de l’intériorité» enclenchée par Wittgenstein est juste en son principe, il s’agira de montrer que l’on ne peut trouver chez Wittgenstein une réfutation implicite de la conception phénoménologique de l’intériorité qu’en faisant une lecture superficielle des Recherches logiques et des Idées directrices. En effet, si l’on sait porter attention aux détails des textes pertinents, on peut déceler chez Husserl une réflexion très fine sur la nature du langage qui débouche éventuellement sur une critique de la conception moderne et empiriste de l’intériorité du sujet très similaire à celle mise en chantier par les i Recherches philosophiques, critique qui, de surcroît, a l’avantage de désamorcer certaines difficultés rencontrées par Wittgenstein. Une telle étude comparative et polémique permettra de tirer deux grandes conclusions à l’égard de la méthode devant être employée en philosophie. Premièrement, il sera démontré que la réflexivité exigée par le discours philosophique se reflète dans l’usage que Husserl et Wittgenstein font des guillemets. Cette observation en apparence triviale permettra d’établir que le discours philosophique repose sur l’usage d’un dispositif typographique banal appartenant à la grammaire de notre langage ordinaire. Ensuite, la supériorité de la méthode « généalogique » de la phénoménologie génétique de Husserl sera mise en relief. Cette dernière a le mérite d’éviter les apories du conventionnalisme de Wittgenstein tout en désamorçant les difficultés soulevées par l’essentialisme de la phénoménologie statique des Idées directrices.Wittgenstein is typically thought to have put forth a devastating critique of one of the most constant temptations of modern philosophy: the so-called "myth of interiority". Against philosophies of reflexion, which attempt to clarify the meaning of obscure philosophical concepts (e.g. truth, significance, thought, etc.) by reflecting upon our mental states (Locke and James come to mind as examples of this paradigm), Wittgenstein showed that such a philosophical project is premised on a profound misunderstanding of how ordinary language and its grammar function. Although Wittgenstein might not have been the first to propose this kind of criticism, his central role in the last century's debates over the problem of interiority is due to the distinctive means through which he carried out this criticism: believing in the value of introspection within philosophical inquiry requires a profound misunderstanding of the nature and operation of the language through which we express our mental life. Since Husserl's phenomenology purports to solve philosophical problems through description and reflection upon lived experience, it is extremely tempting to see him as an inheritor of the philosophical tradition that Wittgenstein's arguments demolished. Taking as its starting point the assumption that the deconstruction of the "myth of interiority" instigated by Wittgenstein is well founded, this project will attempt to show that Wittgenstein's arguments can only appear to refute Husserl's conception of interiority on the basis of a superficial reading of the Logical Investigations and of the Ideas I. Indeed, upon a close examination of the relevant texts, Husserl's reflexions on the nature of language can be shown to lead him to a critique of the modern and empiricist conception of interiority very similar to Wittgenstein's, a critique that turns out to have the resources to avoid some of the major difficulties that the latter faces. This comparative and polemical study will defend two more general theses about the method that philosophical inquiry ought to rely upon. First, it will be argued that the reflexiveness required for philosophical discourse is illustrated in both Husserl and Wittgenstein's use of quotation marks. This seemingly trivial observation will support the claim that philosophical discourse relies on the use of a banal i typographical devise belonging to the grammar of ordinary language. Second, a case will be made for the the superiority of the "genealogical" method of Husserl's genetic phenomenology, for it manages to avoid the pitfalls of Wittgenstein's conventionalism while also steering clear of the problems incurred by the essentialism of the Ideas I static phenomenology

L’usage phénoménologique du langage indexical

Selon une représentation pratique et commode que l’on se fait généralement de la phénoménologie husserlienne, cette dernière se caractériserait par la thèse selon laquelle le langage n’épuise pas le régime du sens. En effet, bien qu’il protestait à l’époque des Recherches logiques contre le caractère « artificiel » de la distinction frégéenne du Sinn et de la Bedeutung, Husserl n’hésitera pas dès le premier tome des Idées directrices à employer la notion de Sinn pour désigner le « sens » pré-..

Sex effect in the temporal perception of faces expressing anger and shame

The aim of the present study was to investigate sex-related variations in the perception of the duration of emotional stimuli (human faces). Twenty male and 20 female participants estimated the duration of angry, ashamed and neutral faces marking 0.4 to 1.6 s intervals. Female faces were used in one session, and male faces in the other. Compared to the angry faces condition, intervals were underestimated when ashamed faces were shown. However, the intervals in neither conditions were significantly overestimated or underestimated compared to the neutral condition. Even more critical is the fact that there was an underestimation by male participants of the duration of male faces compared to female faces; and female participants overestimated the duration in the anger condition, compared with the shame condition, only when male faces were presented. Moreover, the emotional effects on the participants’ performance were correlated to inter-individual differences in empathic abilities. The findings are discussed in terms of sex differences, of social context, and of how attention is solicited and arousal generated by emotions. Keywords: Psychological time, emotions, sex differenc

Closed Crack Detection in Concrete with Coda Wave Non-Linear Modulation

International audienceConcrete is a widely used construction material by virtue of its cost and mechanical properties. Due to its low tensile strength however, concrete is very sensitive to crack formation. Cracks in concrete are responsible for significant inspection, maintenance and repair costs. In order to optimize structural health management, Non-Destructive Testing (NDT) has been extensively studied. Among all NDT techniques, ultrasonic methods are considered advantageous by providing information on mechanical properties in areas not directly accessible from the surface. Recent studies have led to developing nonlinear ultrasonic methods to increase the sensitivity to damage making possible the detection of large cracks/notches and the monitoring of crack evolution. However, the detection of small cracks in concrete remains a great challenge for NDT techniques. In this study, an ultrasonic method, based on nonlinear acoustic mixing of coda waves by lower-frequency swept pump waves, providing for an efficient global detection of small cracks in concrete is presented. By simultaneous comparison, for uncracked and cracked mortars, of ultrasonic velocity variations and decorrelation coefficient between the unperturbed and the perturbed signals for different pump amplitude, the method allows to accurately detect very small cracks with widths of around 20 mm correlated with velocity variations of approximately 0.01%. This method is reproducible and able to provide a simple means for differentiating damaged and sound concrete. Attention must be paid however to the material evolution during the time span of both a single experiment and the entire experimental campaign as a consequence of the presumed high sensitivity of the observables. Several applications of this technique could be developed in the field of civil engineering, although the power of the pump source would constitute a limitation. For example, the detection of small cracks causing leakage could be performed without any need for percolating fluid

ODAS: Open embeddeD Audition System

Artificial audition aims at providing hearing capabilities to machines, computers and robots. Existing frameworks in robot audition offer interesting sound source localization, tracking and separation performance, but involve a significant amount of computations that limit their use on robots with embedded computing capabilities. This paper presents ODAS, the Open embeddeD Audition System framework, which includes strategies to reduce the computational load and perform robot audition tasks on low-cost embedded computing systems. It presents key features of ODAS, along with cases illustrating its uses in different robots and artificial audition applications