An image-based approach to interactive crease extraction and rendering

AbstractRidge and valley manifolds are receiving a growing attention in visualization research due to their ability to reveal the shapes of salient structures in numerical datasets across scientific, engineering, and medical applications. However, the methods proposed to date for their extraction in the visualization and image analysis literature are computationally expensive and typically applied in an offline setting. This setup does not properly support a userdriven exploration, which often requires control over various parameters tuned to filter false positives and spurious artifacts and highlight the most significant structures. This paper presents a GPU-based adaptive technique for crease extraction and visualization across scales. Our method combines a scale-space analysis of the data in pre-processing with a ray casting approach supporting a robust and efficient one-dimensional numerical search, and an image-based rendering strategy. This general framework achieves high-quality crease surface representations at interactive frame rates. Results are proposed for analytical, medical, and computational datasets

Sentient: An Investigation of the Sensuous Self

I choreograph with the goal of filling the space with palpably sensuous experiences. As living bodies (dancer or not), we construct our own reality based on experience. The medium for experiencing the outside world is the body, more specifically the sensing body. Through sense memory, we attach ourselves to the world around us, drawing conclusions and connections according to what we see, hear, smell, touch, and taste. Sense memory is a rich and compelling tool I’ve had dancers utilize in making movement that I eventually compile and organize. Although dance performance is a dominantly visual art form, I aim to engage the whole physical self, the sensing self, to communicate with my work when an audience experiences it. Personally, dance choreography is an outlet for investigating the nuances in human connections, both on and offstage. Dance has the potential to reflect the person we don’t share with the larger community on a daily basis. I’m influenced by the strength in vulnerability, the sincerity in dancing with another person, and the generosity in sharing secrets with strangers in the abyss-like setting of a darkened theater. Dance choreography can act as a magnifying lens to the human condition or abstract elemental aspects of how we’re individually wired. The body can potentially transform into something novel or ordinary. Nevertheless revelations are made. How beautiful is the dancing body that it can rewrite history like this. I act on sensitive intuition and an architectural eye for shapes and figures. The empty space is a blank sheet of paper and my dancers become the blueprint on the page. I’m literally building my work with muscles and bones, directing how they carve through space, how they lie still, or how they weave together to create instantaneous snapshots of human interaction. And just as an edifice has its own unique creaks, echoes, and resonance, each dancer has an internal rhythm that converses with another to make a unique phrase or relationship. The music and architecture of the human body amalgamate to create movement. This semester I choreographed two separate pieces: Imprints of Wounded Marble, Lodestone. These pieces serve as a physical commentary on my artistic perspective—within the dance-making process, performance, and being a regular Jane looking for connections, however varied in nature

Visualization of intricate flow structures for vortex breakdown analysis

Journal ArticleVortex breakdowns and flow recirculation are essential phenomena in aeronautics where they appear as a limiting factor in the design of modern aircrafts. Because of the inherent intricacy of these features, standard flow visualization techniques typically yield cluttered depictions. The paper addresses the challenges raised by the visual exploration and validation of two CFD simulations involving vortex breakdown. To permit accurate and insightful visualization we propose a new approach that unfolds the geometry of the breakdown region by letting a plane travel through the structure along a curve. We track the continuous evolution of the associated projected vector field using the theoretical framework of parametric topology. To improve the understanding of the spatial relationship between the resulting curves and lines we use direct volume rendering and multi-dimensional transfer functions for the display of flow-derived scalar quantities. This enriches the visualization and provides an intuitive context for the extracted topological information. Our results offer clear, synthetic depictions that permit new insight into the structural properties of vortex breakdowns

On the role of domain-specific knowledge in the visualization of technical flows

In this paper, we present an overview of a number of existing flow visualization methods, developed by the authors in the recent past, that are specifically aimed at integrating and leveraging domain-specific knowledge into the visualization process. These methods transcend the traditional divide between interactive exploration and featurebased schemes and allow a visualization user to benefit from the abstraction properties of feature extraction and topological methods while retaining intuitive and interactive control over the visual analysis process, as we demonstrate on a number of examples

Les libertins érudits ou la morale des corrompus

Les libertins sont regardés par les dévots comme des malades, susceptibles de contaminer le corps social avec leurs raisonnements pervertis. Pour leurs adversaires, leur liberté de pensée n’a aucune valeur philosophique. Elle sert seulement de justification à leur goût pour la débauche. Sous le masque, par prudence face aux pouvoirs, ils défendent en effet l’importance des désirs, y compris sexuels. Mais sont-ils pour autant corrompus ? Ils n’hésitent pas à se réapproprier la notion de corruption, pour accuser les jésuites d’immoralité. Ils savent prendre la posture du moraliste. Pour eux, seule la recherche du juste milieu garantit la liberté et la tranquillité du sage. Leur morale n’est toutefois pas celle de la faute, qui fait de tout homme un pécheur. Le libertinage tente de réconcilier l’homme avec sa nature, qui est corruptible, soumise à la maladie et aux ravages du temps. Ils invitent ainsi à considérer la corruption, libérée de tout discours moralisateur, comme indissociable de l’existence, à laquelle elle vient même donner une partie de sa valeur

Influence of local and remote white matter conductivity anisotropy for a thalamic source on EEG/MEG field and return current computation

nverse methods are used to reconstruct current sources in the human brain by means of Electroencephalogra- phy (EEG) and Magnetoencephalography (MEG) measure- ments of event related fields or epileptic seizures. There exists a persistent uncertainty regarding the influence of anisotropy of the white matter compartment on neural source reconstruc- tion. In this paper, we study the sensitivity to anisotropy of the EEG/MEG forward problem for a thalamic source in a high resolution finite element volume conductor. The influence of anisotropy on computed fields will be presented by both high resolution visualization of fields and return current flow and topography and magnitude error measures. We pay particular attention to the influence of local conductivity changes in the neighborhood of the source. The combination of simulation and visualization provides deep insight into the effect of white matter conductivity anisotropy. We found that for both EEG and MEG formulations, the local presence of electrical anisotropy in the tissue surroun- ding the source substantially compromised the forward field computation, and correspondingly, the inverse source recons- truction. The degree of error resulting from the uncompen- sated presence of tissue anisotropy depended strongly on the proximity of the anisotropy to the source; remote anisotropy had a much weaker influence than anisotropic tissue that included the source

Acteurs et activités en humanités numériques à l'École normale supérieure: Enquête

A survey on actors and activities in digital humanities existing at ENS-Ulm was conducted from July 2017 to June 2018 within the Digit_Hum initiative. 67 actors were identified and 76 projects identified (projects, scientific events and training). We provide here the results of this survey, as well as a list of the activities identified (which will be enriched over time), and an interactive institutional network showing the collaborations between the ENS and its partner institutions in the framework of its activities in digital humanities. This survey was set up by Marie-Laure Massot (CAPHÉS) and Agnès Tricoche (labex TransferS), with the help of the ENS Digital Humanities Coordination Mission. Graphic design by A. Picandet.For any questions, please contact digit_hum[at]ens.fr.Une enquête sur les acteurs et les activités en humanités numériques existant à l’ENS-Ulm a été menée de juillet 2017 à juin 2018 au sein de l'initiative Digit_Hum. 67 acteurs ont été identifiés et 76 projets recensés (projets, manifestations scientifiques et formations). Nous mettons ici à disposition les résultats de cette enquête, ainsi qu'une liste des activités recensées (amenée à s'enrichir au fil de l’eau), et un réseau institutionnel interactif montrant les collaborations entre l'ENS et ses institutions partenaires dans le cadre de ses activités en humanités numériques. Cette enquête a été mise en place par Marie-Laure Massot (CAPHÉS) et Agnès Tricoche (labex TransferS), avec l'aide de la Mission de coordination des humanités numériques de l’ENS. Conception graphique par A. Picandet.Pour toute question, contacter digit_hum[at]ens.fr