Bioluminescence is widespread in the deep sea. In this study, the density of bioluminescent zooplankton (BL) in the deep Mediterranean Sea (MS) and at the Mid- Atlantic Ridge (MAR) was measured using low light video cameras, including a novel Image intensified Charge coupled device for Deep-sea research (ICDeep). Sampling across the MS was undertaken to assess the potential optical interference from bioluminescent zooplankton at sites under consideration for the construction of a large volume deep-sea neutrino telescope. This revealed a general decrease in deep pelagic BL densities from the western to the eastern MS. Deep mesopelagic (500- 1000 m depth) BL density was significantly correlated (p<O.Ol) to Chlorophyll a concentrations in overlying surface waters. Investigation of temporal variation across the Ionian Sea revealed a deep (500-2400 m depth) peak in BL density on the western side, present in the autumn (mean BL density: 14.92 m-3) and absent the following spring (4.52 rrr"). Deep water of Adriatic origin flows into this region and may seasonally affect the supply of organic material, increasing deep zooplankton populations. Near-bed (0-400 m above bed, mab) BL density in the MS was found to decrease exponentially with seafloor depth; by a factor of 4.2 every 1000 m. BL densities were consistently lower in the MS than at the MAR. On the MAR, at ca. 2500 m depth, an investigation of altitude effects within the near seafloor region revealed a weak increase (0.016 m-3 mab': p<O.OOl) in BL and inacroparticle (>430 urn] densities from 100 to 5 mab attwo sites south of the Charlie-Gibbs Fracture Zone. At 2500 m depth on the MAR, a rate of naturally occurring bioluminescent events was observed to be 155 times higher (3.1 min+) than literature based predictions, prompting a reappraisal of the visual environment in relation to complex topography of the deep-sea floor.

Notre recherche concerne les nouvelles approches qui améliorent l’exploration 3D dans des environnements virtuels pour les utilisateurs. De ce fait, nous nous focalisons sur la conception de nouvelles techniques d’interaction 3D transversales, qui sont simples, efficaces et bénéficient de la nouvelle périphérique d’entrée, comme les interfaces tactiles. Notre approche permet aux utilisateurs d’effectuer une interaction 3D complexes à l’aide d’entrée touche simple et multiples. Les utilisateurs effectuer des gestes en utilisent des touches simple et des esquisses pour interagir avec le contenu. Pour faire des conclusions sur la facilité d’utilisation de nos interfaces nous évaluons les techniques d’interaction en menant des études utilisateurs. Ensuite, nous adoptons des techniques traditionnelles et d’illustration de visualisation pour mettre en avant des caractéristiques différentes de l’objet en cible tout en préservant les informations de contexte. En outre, nous proposons de nouvelles méthodes de collaboration entre les utilisateurs qui interagissent avec les données 3D en utilisant la technologie divers, comme des périphériques mobiles de petite taille et des environnements virtuels immersifs. / Our research concerns the investigation of new approaches that enhance 3D exploration in virtual environments for users. Thereby, we concentrate on design of novel transversal 3D interaction techniques that are simple, efficient and benefit from new input technology, like tactile interfaces. Our approach allows users to perform complex 3D interaction using single and multiple 2D touch input. Users carry out simple touch, stroke or sketch-based gestures to interact with content. To draw conclusions about the usability of our interfaces we evaluate the interaction techniques by conducting users studies. In addition, we adopt different traditional and illustrative visualization techniques to highlight object characteristics in focus while preserving context information. Furthermore, we propose new methods for collaboration between users, who interact together with 3D data using varying technology, from small mobile devices to immersive virtual environments.

The usefulness of electromagnetic (EM) methods for mineral exploration is severely restricted by the presence of a conductive overburden. Approximately 80% of the Australian continent is covered by regolith that contains some of the most conductive clays on Earth. As a result, frequency-domain methods are only effective for near surface investigations and time-domain methods, that are capable of deeper exploration, require the measurement of very small, late-time signals. Both methods suffer from the fact that the currents in the conductive Earth layers contribute a large portion of the total measured signal that may mask the signal from a conductive target. In the search for non-layered structures, this form of geological noise is the greatest impediment to the success of EM surveys in conductive terrains. Over the years a range of data acquisition and processing techniques have been used in an effort to enhance the response of the non-layered target and thereby increase the likelihood of its detection.The combined use of a variety of survey configurations to assist exploration and interpretation is not new and is practiced regularly. The active nature of EM exploration means that the measured response is determined to a large degree by the way in which the Earth is energised. Geological structures produce different responses to different stimuli. In this work, two new methods of data combination are used to transform the measured data into a residual quantity that enhances the signature of non-layered geological structures. Based on the concept of data redundancy and tested using the results of numerical modelling, the new combinations greatly increase the signal to noise ratio for targets located in a conductive environment by reducing the layered Earth contribution. The data combinations have application to frequency-domain and time-domain EM surveys and simple ++ / interpretive rules can be applied to the residuals to extract geological parameters useful in exploration. The new methods make use of inductive loop sources and can therefore also be applied to airborne surveys.Airborne surveys present special difficulties due to the data acquisition procedures commonly used. Flight-line related artefacts such as herringbones detract from the appearance of maps and make boundary definition more difficult. A new procedure, based on the Radon transform, is used to remove herringbones from airborne EM maps and locate the conductive boundaries correctly, making interpretation more reliable and easier. In addition, selective filtering of the Radon transform data enables the enhancement or attenuation of specific linear features shown in the map to emphasise features of interest. Comparison of the Radon transform procedures with the more conventional Fourier transform methods shaves the Radon transform processing to be more versatile and less prone to distortion of the features in a map.The procedures developed in this work are applied to field data with good results.

Master of Engineering (Research) / This thesis deals with the problem of cooperative explorations of a group of autonomous vehicles in unknown environments in the context of decentralized behaviour. The main contribution of this thesis is the development of a comprehensive decentralized cooperative exploration frame work in which each individual vehicle has the ability to explore an unknown environment by itself and also by cooperative behaviour in a team of several vehicles. To simulate the whole system, each individual vehicle will have the ability to explore an unknown environment by dynamically path-planning (with obstacle and collision avoidance), high-level con- trolling, updating the environment map, proposing potential destinations (frontiers), and solving online task assignment. In this thesis, the framework simulates an unknown environment as an occupancy grid map and uses a frontier-base exploration strategy, in which a cell will be marked as a frontier if it is adjacent at least one open cell, as the core architecture. In dealing with the uncertainties in process transition and observation models of autonomous vehicles, the well-known discrete extended Kalman filter (EKF) algorithm is investigated and implemented. When exploring the environment, a vehicle will update its surrounding information, then propose its potential destinations and evaluate the utility (benefit) to travel to each of those destinations. The benefit to go to each destination is derived from the subtraction of the utility (value) of that cell to the sum of the cost to travel to that cell and the steering cost. The key to cooperative exploration in the team of vehicles lies in each vehicle's ability to communicate the updates of the world to the whole team and to contribute to the global list of potential destinations. And each vehicle has the capability of solving the task assignment problem for the team by calling its own online-task-assignment solving engine. This algorithm results each vehicle in having a destination to visit, which benefits the whole team the most and reduces the total exploration time of the team.

According to attachment theory a key moderator in the enjoyment of exploration is the strength of a person's secure base. To study exploration we placed participants in a situation in which they confronted a novel stimulus. We also gathered self-reported data on their mood immediately before and after this encounter with a novel stimulus as well as their attitudes about the novel stimulus activity. The effect of a ?secure base? on this encounter was examined in two ways: first through chronic attachment, and second through priming participants with either a secure attachment prime, an insecure attachment prime or a neutral prime. Thus, this study makes two categories of predictions: the first regarding the effect of chronic attachment, and the second regarding the effect of primed attachment. Regarding the effect of chronic attachment, we predicted that there would be an interaction between the novelty of the stimulus and chronic attachment. Specifically, we found that both chronic attachment avoidance and chronic attachment anxiety predicted greater tense mood following the activity and greater anxiety about the activity. In addition, we found that chronic avoidant attachment was related to greater anger following the activity and less happiness following the activity. These results remained significant even when mood immediately before the activity was controlled. Regarding primed attachment, we found that there was an interaction between primed attachment and novelty condition. (During the study, participants in the low novelty condition interacted more extensively with the novelty stimulus than did participants in the high novelty condition.) Specifically, we found that participants in the low novelty condition reacted more strongly to the attachment prime than participants in the high novelty condition. Further, the attachment prime predicted the direction of the change in mood. Thus, for the low novelty conditions, participants primed with secure attachment reported significantly more happiness and higher positive affect on a composite mood scale, compared with participants primed with insecure attachment. In the same way, again for the low novelty conditions, participants primed with secure attachment reported significantly lower levels of anger, compared with participants primed with insecure attachment.

Thèse doctorat : Informatique : Villeurbanne, INSA : 2004. / Titre provenant de l'écran-titre. Bibliogr. p. 129-136.

reproduction de : Thèse de doctorat : Informatique : Lyon 2 : 2004. / Titre provenant de l'écran-titre. Bibliogr.

Thèse doctorat : Informatique : Villeurbanne, INSA : 2007. / Titre provenant de l'écran-titre. Bibliogr. p. 123-134.

Reproduction de : Thèse doctorat : Informatique : Metz : 2003. / Titre provenant de l'écran-titre. Notes bibliographiques.

Thèse de doctorat : Informatique : Lyon 2 : 2001. / Titre provenant de l'écran-titre. Bibliogr.