Teses / dissertações sobre o tema "Explorers and exploration"

My thesis describes the praxis of geographical exploration in the mid-nineteenth century through the activities of members of the Royal Geographical Society of London (RGS). I focus on the First East African Expedition (1856-1859), which was led by Richard F. Burton. Geographical exploration was intended to provide data that would allow geographers in Britain to construct an accurate description of East Africa, with emphasis on the rivers and lakes that may contribute to the waters of the Nile and ethnographic research. Earlier geographies of the East African interior had relied upon a variety of sources: ancient, Arab, Portuguese, and local informants. In order to replace these sources with precise observation, the RGS provided some prescriptive instructions to explorers based upon the techniques of celestial navigation and surveying available for field research in the 1850s. The instructions emphasized careful, daily recording of data, using instruments as much as possible. However, in the field explorers experienced a diminished ability to control the consistency of their observations due to insufficient finances, politics, disease, and climate. Where unable to directly observe, they relied upon local informants for descriptions of the regional geography. These informants had a great impact upon the geographies produced by the expedition. In order to complete a full description of the praxis of geographical exploration it therefore becomes necessary to consider the expedition in its wider context--as a remote sensing tool for a scientific society and as a contingent of foreigners visiting a region for which they have little information and entered only with local permission. I propose that five steps, or contexts, must be considered during the analysis of expeditions: contact, acquisition, appropriation, reporting, meta-analysis. These steps make lucid the epistemic transformations that must take place as explorers gather data in the field. At each stage the identity of the individuals involved are contingent upon their relationship with each other and the information they desire. The relationship between explorers and local informants was especially critical to the establishment of credibility. Even when fully trusted by explorers, the British geographers who analyzed expedition data and generated maps of the region debated the veracity of local informants. Explorers (and by extension, local informants) found that other researchers, through the meta-analysis of expedition reports, appropriated any ownership of the information produced by expeditions.
Master of Science

Over eighty polar-themed exhibitions were held in Britain between 1819 and the 1930s, a time of intense exploration of both the Arctic and Antarctic. These varied from panoramas and human exhibits to displays of ‘relics', equipment, photographs and artwork, waxworks and displays shown as part of a Great Exhibition. This period also saw the creation of the first dedicated polar museums. These displays were visited by thousands of people throughout the country, helping to mediate the subject of exploration for a public audience. Despite this, the role exhibitions played in forming popular views of the polar regions has not been fully assessed. This thesis addresses this gap. It is the first to consider all the polar exhibitions held during this period as a collective body, making it possible to study how they developed over time and in response to changing circumstances. The thesis uses a variety of archival sources to both reconstruct the displays and place them in their historical and museological contexts. The study shows that exhibitions evolved in response to changes both in the museum sector and in exploration culture. It demonstrates that, while they were originally identified with the shows of the entertainment industry, polar exhibitions began to take on more of the characteristics of museum displays. At the same time their dominant themes changed; the natural world was relegated in favour of ideas relating to the human experience of the regions such as heroism, adventure and everyday life in an exotic environment. While other media may have been more effective in disseminating ideas about exploration, visitors could find the experience of visiting an exhibition more compelling. This thesis contributes to our understanding of this distinct role that exhibitions played in presenting the polar regions to the British public.

Designing user-interfaces so that first-time or infrequent users can accomplish their goals by exploration has been an enduring challenge in Human-Computer Interaction. Iterative user-testing is an effective but costly method to develop user-interfaces that support use through exploration. A complementary method is to use modeling tools that can generate predictions of user exploration given a user-interface and a goal description. Recent computational models of goal-directed user exploration have focused on predicting user exploration of websites and demonstrated how predictions can inform user-interface design. These models employ the common concepts of label following and information scent: that the user's choice is partly determined by the semantic relevance between the user's goal and the options presented in the user-interface. However, in addition to information scent, other factors including the layout position and grouping of options in the user-interface also affect user exploration and the likelihood of success. This dissertation contributes a new model of goal-directed user exploration, called CogTool- Explorer, which considers the layout position and the grouping of options in the user-interface in concert with a serial evaluation visual search process and information scent. Tests show that predictions from CogTool-Explorer match participant data better than alternative models that do not consider layout position and grouping. This dissertation work has also integrated the CogTool- Explorer model into an existing modeling tool, called CogTool, making it easier for other researchers and practitioners to setup and generate predictions of likely user exploration paths and task performance using CogTool-Explorer.

Dans cette thèse, nous étudions les façons dont des techniques inspirées de la planification de mouvement peuvent accélérer la résolution de problèmes d'exploration difficile pour l'apprentissage par renforcement, sans sacrifier la généralisation ni les avantages de l'apprentissage sans modèle. Nous identifions une impasse qui peut advenir lors qu'on applique l'apprentissage par renforcement à des problèmes apparemment triviaux mais qui ont une récompense éparse. De plus, nous contribuons un algorithme d'exploration inspiré de la planification de mouvement mais conçu spécifiquement pour des environnements d'apprentissage, ainsi qu'un cadre pour utiliser les données collectées pour entraîner un algorithme d'apprentissage par renforcement dans des scénarios auparavant trop complexes
Motion planning is able to solve robotics problems much quicker than any reinforcement learning algorithm by efficiently searching for a viable trajectory. Indeed, while the main object of interest in the field of Reinforcement Learning is the behavior of an agent, Motion Planning is concerned with the geometry and properties of the state-space, and uses a different set of primitives to achieve more efficient exploration. Some of these primitives require a model of the system and are not studied in this work, others such as reset-anywhere are only available in simulated environments. In contrast, Motion Planning approaches do not benefit from the same generalization properties as the policies produced by reinforcement learning. In this thesis, we study the ways in which techniques inspired from motion planning can speed up the solving of hard exploration problems for reinforcement learning without sacrificing the advantages of model-free learning and generalization. We identify a deadlock that can occur when applying reinforcement learning to seemingly-trivial sparse-reward problems, and contribute an exploration algorithm inspired by motion planning but specifically designed for reinforcement learning environments, as well as a framework to use the collected data to train a reinforcement learning algorithm in previously-intractable scenarios

Les robots mobiles trouvent des applications dans des environnements domestiques, ainsi que dans l'agriculture, où ils permettent une agriculture de précision, et dans la logistique, garantissant le transport efficace de matériaux et de marchandises. De plus, ils jouent un rôle crucial dans l'exécution d'une large gamme de tâches difficiles ou dangereuses pour les humains, étant essentiels dans les missions de couverture de zone.L'objectif principal d'une mission de couverture de zone est de traverser et d'explorer systématiquement une zone définie, en ne laissant aucune région inexplorée. Ces missions sont souvent entreprises dans des environnements présentant des risques significatifs pour les opérateurs humains, tels que des champs minés ou des zones sinistrées. Dans ce contexte, les missions de déminage et les opérations de recherche et de sauvetage sont des exemples de missions de couverture de zone avec un caractère critique pour la sécurité.Une connaissance précise de la zone explorée par un robot mobile est cruciale pour évaluer l'achèvement de ces missions. Certaines applications peuvent également nécessiter que le robot revisite une zone d'intérêt. Dans ce cas, pour vérifier si la mission est complète, il est nécessaire de déterminer combien de fois chaque partie de l'espace a été dans la zone de détection du robot.Dans ce contexte, nous introduisons le concept de mesure de couverture, qui représente combien de fois une partie de l'environnement a été explorée par un robot mobile au cours d'une mission. En plus d'évaluer les missions où il faut revisiter des points d'intérêt, la mesure de couverture est également utile pour l'optimisation des trajets et pour améliorer l'efficacité des algorithmes de localisation dans des environnements homogènes, tels que l'environnement sous-marin.De plus, nous établissons une relation entre la mesure de couverture et le degré topologique. Cette relation nous permet de proposer une nouvelle approche pour estimer la zone explorée en se basant sur les propriétés topologiques de l'environnement qui a été observé. L'incertitude associée à la mission est prise en compte grâce à l'utilisation de l'analyse par intervalles dans la formalisation du problème.La théorie et les algorithmes développés dans cette thèse sont illustrés par des expériences en conditions réelles dans l'environnement marin
Mobile robots are increasingly being deployed across different domains. These robots find applications in domestic settings, as well as in agriculture, where they enable precision farming, and logistics, ensuring the efficient transportation of materials and goods. Moreover, they play crucial roles carrying out a wide range of challenging tasks that would be too dangerous or difficult for humans, being pivotal in area-covering missions.Area-covering missions refer to tasks where the primary objective is to systematically traverse and explore a defined area, leaving no region unexamined. Additionally, they are often undertaken in environments that pose significant risks to human operators, such as minefields or disaster-stricken areas. In this context, examples of safety-critical area-covering missions are Mine Countermeasure (MCM) missions and Search and Rescue (SAR) operations.Accurate knowledge of the area explored by a mobile robot is crucial for assessing the completeness of these missions. Some applications might also require the robot to revisit an area of interest, in this case, to verify the completion a mission, one has to be capable of determining how many times each part of the space has been in the robot's range of detection.In this context, we introduce the concept of coverage measure, that represents how many times a part of the environment was explored by a mobile robot during a mission. In adition to evaluating revisiting missions, the coverage measure is also useful for path optimization and it can be valuable for improving the efficiency of localization algorithms in homogeneous environments, such as the underwater environment.Furthermore, we establish a relation between the coverage measure and the topological degree. This relation allows us to propose a novel approach for estimating the explored area based on topological properties of the environment that has been observed. Uncertainty associated to the mission in noisy environments is taken into consideration through the use of interval analysis in the problem formalization.The theory and the algorithms developed in this thesis are illustreated through real world experiments in the marine environment

This dissertation consists of four articles and a summary. The main focus of the studies is students' explorations in upper secondary school mathematics. In the first study the central research question was to find out if the students could learn something difficult by using the graphing calculator. The students were working with questions connected to factorisation of quadratic polynomials, and the factor theorem. The results indicate that the students got a better understanding for the factor theorem, and for the connection between graphical and algebraical representations. The second study focused on a the last part of an investigation, the verification of an idea or a conjecture. Students were given three conjectures and asked to decide if they were true or false, and also to explain why the conjectures were true or false. In this study I found that the students wanted to use rather abstract mathematics in order to verify the conjectures. Since the results from the second study disagreed with other research in similar situations, I wanted to see what Swedish teachers had to say of the students' ways to verify the conjectures. The third study is an interview study where some teachers were asked what expectations they had on students who were supposed to verify the three conjectures from the second study. The teachers were also confronted with examples from my second study, and asked to comment on how the students performed. The results indicate that teachers tend to underestimate students' mathematical reasoning. A central focus to all my three studies is explorations in mathematics. My fourth study, a revised version of a pilot study performed 1998, concerns exactly that: how students in upper secondary school explore a mathematical concept. The results indicate that the students are able to perform explorations in mathematics, and that the graphing calculator has a potential as a pedagogical aid, it can be a support for the students' mathematical reasoning.

Thesis: Ph. D. in Engineering Systems, Massachusetts Institute of Technology, School of Engineering, Institute for Data, Systems, and Society, 2016.
Some pages printed landscape orientation. Cataloged from PDF version of thesis.
Includes bibliographical references (pages 342-351).
This work proposes a merger of Tradespace Exploration with System Dynamics modeling techniques in a complementary approach. It tests the value of this mixed method for modeling the multiplicity of inputs and complexity of feedback loops that affect the cost, schedule and performance of satellite constellations within the Department of Defense. The resulting simulation enables direct comparison of the effect of changing architectural design points and policy choices with respect to satellite acquisitions and fielding. A generation-over-generation examination of policy choices is made possible through the application of soft systems modeling of experience and learning effects. The resulting model enables examination of possible futures given variations in assumptions about both internal and external forces on a satellite production pipeline. This thesis performs a policy analysis examining the current path of the Global Positioning System acquisition and compares it to equivalent position navigation and timing capability delivered through a variety of disaggregated options while varying: design lives, production quantities, non-recurring engineering and time between generations. The extensibility of this technique is investigated by adapting the model to the mission area of Weather and Climate Sensing. This thesis then performs a policy analysis examining different disaggregated approaches for the Joint Polar Satellite, focusing on the impact of complexity. Discussion of factors such as design choices, context variables, tuning variables, model execution and construction is also included.
by Paul A. La Tour.
Ph. D. in Engineering Systems

Les travaux menés dans cette thèse ont porté sur l’exploration électrophysiologique de l’excitabilité neuromusculaire et de la fatigue à l’effort chez l’homme sain et malade. Des techniques d’exploration non-invasives ont été développées dans ce but, pour appréhender les mécanismes physiopathologiques impliqués au niveau cortical, médullaire, nerveux et musculaire. Après validation chez le sujet sain, ces tests ont été appliqués à l’étude de pathologies neurologiques affectant le système nerveux central (sclérose en plaques), nerveux périphérique (diverses neuropathies) ou musculaire (dystrophie myotonique). Les résultats obtenus dans ce travail ont été discutés avec l’objectif de préciser les mécanismes physiopathologiques potentiellement incriminés. La rapidité, le caractère non douloureux et la bonne répétabilité de ces tests font envisager leur future application en pratique neurophysiologique pour assurer le suivi longitudinal ou l’évaluation des effets d’un traitement
The present work focused on electrophysiological assessment of neuromuscular excitability and effort-related fatigability in healthy humans and patients. Non-invasive techniques have been developed in this goal, to appraise the pathophysiological mechanisms involved at cortical, spinal, neural or muscular level. Following validation in healthy subjects, these tests have been applied to patients who suffered from disease affecting the central or the peripheral nervous system (multiple sclerosis, neuropathies) or the skeletal muscle (myotonic dystrophy). The results have been interpreted to enlighten the potential pathophysiological causes of such diseases. These studies are not painful and can be rapidly performed with a good repetability, authorizing their future application to ensure long-term follow-up and assessment of therapy in neurophysiological practice

Sense-making of spatial data on an urban level and large-scale decisions on new infrastructure projects need teamwork from experts with varied backgrounds. Technology can facilitate this collaboration process and magnify the effect of collective intelligence. Therefore, this work explores new useful collaboration interactions and visualizations for map-exploration software with a strong focus on usability. Additionally, for same-time and same-place group work, interactive table-top displays serve as a natural platform. Thus, the second aim of this project is to develop a user-friendly concept for integrating table-top displays with collaborative map-exploration. To achieve these goals, we continuously adapted the user-interface of the map-exploration software RAISE. We adopted a user-centred design approach and a simple iterative interaction design lifecycle model. Alternating between quick prototyping and user-testing phases, new design concepts were assessed and consequently improved or rejected. The necessary data was gathered through continuous dialogue with users and experts, a participatory design workshop, and a final observational study. Adopting a cross-device concept, our final prototype supports sharing information between a user’s personal device and table-top display(s). We found that this allows for a comfortable and practical separation between private and shared workspaces. The tool empowers users to share the current camera-position, data queries, and active layers between devices and with other users. We generalized further findings into a set of recommendations for designing user-friendly tools for collaborative map-exploration. The set includes recommendations regarding the sharing behaviour, the user-interface design, and the idea of playfulness in collaboration.

Au cours de leur propagation, les ondes sismiques sont atténuées par deux phénomènes : l'absorption causée par les propriétés anélastiques des matériaux, d'une part, et la diffusion ou " scattering " causée par la présence d'hétérogénéités de petite échelle dans le milieu d'autre part. L'objectif de cette thèse est de cartographier les propriétés de diffusion et d'absorption des ondes sismiques dans deux contextes géophysiques extrêmes présentant des échelles spatiales très différentes. La première partie du manuscrit est consacrée à la stratification d'hétérogénéité dans la Lune. À l'aide d'un modèle original de diffusion en géométrie sphérique, nous avons inversé les mesures de temps d'arrivée du maximum d'énergie et de décroissance de la coda sismique réalisée sur les données des missions Apollo. Nos inversions mettent en évidence un très fort contraste des propriétés de scattering entre le mégarégolithe très atténuant et le manteau lunaire profond transparent. L'atténuation est très largement dominée par le scattering et suggère la présence de fracturation jusqu'à environ 100 km de profondeur, affectant ainsi le manteau. Une nouvelle méthode d'estimation de la profondeur des séismes superficiels fondée sur les signaux diffus a été développée et permet de confirmer l'existence de failles actives autour de 50 km de profondeur. La deuxième partie de la thèse est consacrée à la structure d'atténuation de Taïwan, une région qui présente des structures géologiques très variées dans un contexte tectonique de double subduction. On utilise la MLTWA (Multiple Lapse Time Window Analysis) -une méthode fondée sur le rapport entre énergie cohérente et incohérente du signal sismique- pour imager les variations latérales d'atténuation. Dans un premier temps nous avons travaillé dans l'hypothèse classique de diffusion isotrope dans un demi-espace. Nos résultats mettent en évidence un niveau d'atténuation globale très élevé ainsi que de forts contrastes des propriétés de scattering sur des échelles spatiales fines, de l'ordre de 10-20 km. La diffusion est particulièrement marquée dans les bassins de la côte ouest, le sud et la chaîne côtière associée à la collision avec l'arc volcanique de Luçon à l'est. L'absorption augmente graduellement vers l'est et atteint son maximum sous l'arc volcanique. L'examen de l'accord entre données et modèles a posteriori montre sans ambiguïté les limites de l'hypothèse de diffusion isotrope dans un demi-espace sur un ensemble de stations situées le long des côtes. Ceci nous conduit à explorer les effets de la diffusion anisotrope dans un guide d'onde modélisant la croûte. La prise en compte de l'anisotropie améliore significativement l'accord du modèle aux données. En particulier, à basse fréquence (1-2 Hz), notre étude démontre la prédominance de rétro-diffusion. Ce résultat est compatible avec la présence de forts contrastes d'impédance dans la croûte et suggère la présence massive de fluides dans les zones de failles et de volcans à Taïwan. La mesure de l'anisotropie de la diffusion ouvre des perspectives nouvelles de caractérisation des hétérogénéités géophysiques de petite échelle
During their propagation, seismic waves are attenuated by two phenomena: on one hand, absorption caused by the anelastic properties of the materials, and on the other hand, scattering caused by the presence of small-scale heterogeneities in the medium. The aim of this thesis is to map the properties of scattering and absorption of seismic waves in two extreme geophysical contexts with very different spatial scales. The first part of this memoir is devoted to the stratification of heterogeneities in the Moon. We use a new diffusion model in spherical geometry to invert measurements of the time of arrival of the maximum of energy and the seismic coda decay on data from the Apollo missions. Our inversions provide evidence of a very sharp contrast of scattering properties between the highly attenuating megaregolith and the transparent deep lunar mantle. Attenuation is largerly dominated by scattering and suggests the presence of fractures down to about 100 km depth, into the mantle. A new method for estimating the depth of shallow moonquakes based on diffusive signals was developped and confirms the existence of active faults around 50 km deep. The second part of this thesis is devoted to the attenuation structure of Taiwan, a region with a wide variety of geological structures in the context of two subduction zones. We use the MLTWA (Multiple Lapse Time Window Analysis) -a method based on the ratio between the coherent and incoherent energy of the seismic signal- to image the lateral variations of attenuation. We worked first with the classical hypothesis of isotropic scattering in a half-space. Our results provide evidence for a globally high level of attenuation with sharp contrasts of scattering properties across small spatial scales, of the order of 10-20 km. Scattering is particularly strong in the basins of the west coast, southern Taiwan and the eastern Coastal Range associated with the collision with the Luzon volcanic arc. Absorption increases gradually eastwards and reaches a maximum below the volcanic arc. A posteriori examination of the fit between data and model shows unambiguously the limits of the hypothesis of isotropic scattering in a half-space for a number of stations located along the coasts. This leads us to explore the effects of anisotropic scattering in a guide for seismic waves representing the crust. Taking anisotropy into account significantly improves the fitness of the model to the data. In particular, at low frequency (1-2 Hz), our study shows the prevalence of backscattering. This result is compatible with the presence of sharp contrasts of impedance in the crust and suggests the strong presence of fluids in fault zones and volcanoes in Taiwan. The measurement of scattering anisotropy opens new perspectives for characterizing small-scale geophysical heterogeneities

Avec environ 120 000 personnes atteintes chaque année, 12 000 décès suite à la première crise et 18 000 décès après une année, l'infarctus du myocarde est un enjeu majeur de santé publique. Cette pathologie nécessite une hospitalisation et une prise en charge dans une unité de soins intensifs de cardiologie. Pour étudier cette pathologie, nous nous sommes orientés vers les bases hospitalières du PMSI.La collecte des données hospitalières dans le cadre du PMSI génère sur le plan national des bases de données de l'ordre de 25 millions d'enregistrements par an.Ces données, qui sont initialement recueillies à des fins médico-économiques, contiennent des informations qui peuvent avoir d'autres finalités : amélioration de la prise en charge du patient, prédiction de l'évolution des soins, planification de leurs coûts, etc.Ainsi émerge un autre enjeu : celui de fournir des outils d'explorations des trajectoires hospitalières des patients à partir des données issues du PMSI. Par le biais de plusieurs objectifs, les travaux menés dans le cadre de cette thèse ont pour vocation de proposer des outils combinant des méthodes issues de trois disciplines : informatique médicale, fouille de données et biostatistique.Nous apportons quatre contributions.La première contribution concerne la constitution d'une base de données de qualité pour analyser les trajectoires de patients. La deuxième contribution est une méthode semi-automatique pour la revue systématique de la littérature. Cette partie des travaux délimite les contours du concept de trajectoire dans le domaine biomédical. La troisième contribution est l'identification des parcours à risque dans la prédiction du décès intra-hospitalier. Notre stratégie de recherche s'articule en deux phases : 1) Identification de trajectoires types de patients à l'aide d'outils issus de la fouille de données ; 2) Construction d'un modèle de prédiction à partir de ces trajectoires afin de prédire le décès. Enfin, la dernière contribution est la caractérisation des flux de patients à travers les différents évènements hospitaliers mais aussi en termes de délais d'occurrences et de coûts de ces évènements. Dans cette partie, nous proposons à nouveau une alliance entre une méthode de fouille de données et de classification de données longitudinales
With approximately 120,000 people affected each year, 12,000 deaths from the first crisis and 18,000 deaths after one year, myocardial infarction is a major public health issue. This pathology requires hospitalization and management in an intensive care cardiology unit. We study this pathology using the French national Prospective Paiement System (PPS) databases.The collection of national hospital data within the framework of the PPS generates about 25 million records per year.These data, which are initially collected for medico-economic purposes, contain information that may have other purposes: improving patient care, predicting the evolution of care, planning their costs, etc.Another emerging issue is that of providing tools for exploring patients' hospital trajectories using data from the PPS. Through several objectives, this thesis aims to suggest tools combining methods from three disciplines: medical computing, data mining and biostatistics.We make four contributions.The first contribution concerns the constitution of a quality database to analyze patient trajectories. The second contribution is a semi-automatic method for the systematic review of the literature. This part of the work delineates the contours of the trajectory concept in the biomedical field. The third contribution is the identification of care trajectories in the prediction of intra-hospital death. Our research strategy is divided into two phases: 1) Identification of typical patient trajectories using data mining tools; 2) Construction of a prediction model from these trajectories to predict death. Finally, the last contribution is the characterization of patient flows through the various hospital events, also considering of delays and costs. In this contribution, we propose a combined-data mining and a longitudinal data clustering technique

Le texte est l'une des sources d'informations les plus répandues et les plus persistantes. L'analyse de contenu du texte se réfère à des méthodes d'étude et de récupération d'informations à partir de documents. Aujourd'hui, avec une quantité de texte disponible en ligne toujours croissante l'analyse de contenu du texte revêt une grande importance parce qu' elle permet une variété d'applications. À cette fin, les méthodes d'apprentissage de la représentation sans supervision telles que les modèles thématiques et les word embeddings constituent des outils importants.L'objectif de cette dissertation est d'étudier et de relever des défis dans ce domaine.Dans la première partie de la thèse, nous nous concentrons sur les modèles thématiques et plus précisément sur la manière d'incorporer des informations antérieures sur la structure du texte à ces modèles.Les modèles de sujets sont basés sur le principe du sac-de-mots et, par conséquent, les mots sont échangeables. Bien que cette hypothèse profite les calculs des probabilités conditionnelles, cela entraîne une perte d'information.Pour éviter cette limitation, nous proposons deux mécanismes qui étendent les modèles de sujets en intégrant leur connaissance de la structure du texte. Nous supposons que les documents sont répartis dans des segments de texte cohérents. Le premier mécanisme attribue le même sujet aux mots d'un segment. La seconde, capitalise sur les propriétés de copulas, un outil principalement utilisé dans les domaines de l'économie et de la gestion des risques, qui sert à modéliser les distributions communes de densité de probabilité des variables aléatoires tout en n'accédant qu'à leurs marginaux.La deuxième partie de la thèse explore les modèles de sujets bilingues pour les collections comparables avec des alignements de documents explicites. En règle générale, une collection de documents pour ces modèles se présente sous la forme de paires de documents comparables. Les documents d'une paire sont écrits dans différentes langues et sont thématiquement similaires. À moins de traductions, les documents d'une paire sont semblables dans une certaine mesure seulement. Pendant ce temps, les modèles de sujets représentatifs supposent que les documents ont des distributions thématiques identiques, ce qui constitue une hypothèse forte et limitante. Pour le surmonter, nous proposons de nouveaux modèles thématiques bilingues qui intègrent la notion de similitude interlingue des documents qui constituent les paires dans leurs processus générateurs et d'inférence.La dernière partie de la thèse porte sur l'utilisation d'embeddings de mots et de réseaux de neurones pour trois applications d'exploration de texte. Tout d'abord, nous abordons la classification du document polylinguistique où nous soutenons que les traductions d'un document peuvent être utilisées pour enrichir sa représentation. À l'aide d'un codeur automatique pour obtenir ces représentations de documents robustes, nous démontrons des améliorations dans la tâche de classification de documents multi-classes. Deuxièmement, nous explorons la classification des tweets à plusieurs tâches en soutenant que, en formant conjointement des systèmes de classification utilisant des tâches corrélées, on peut améliorer la performance obtenue. À cette fin, nous montrons comment réaliser des performances de pointe sur une tâche de classification du sentiment en utilisant des réseaux neuronaux récurrents. La troisième application que nous explorons est la récupération d'informations entre langues. Compte tenu d'un document écrit dans une langue, la tâche consiste à récupérer les documents les plus similaires à partir d'un ensemble de documents écrits dans une autre langue. Dans cette ligne de recherche, nous montrons qu'en adaptant le problème du transport pour la tâche d'estimation des distances documentaires, on peut obtenir des améliorations importantes
Text is one of the most pervasive and persistent sources of information. Content analysis of text in its broad sense refers to methods for studying and retrieving information from documents. Nowadays, with the ever increasing amounts of text becoming available online is several languages and different styles, content analysis of text is of tremendous importance as it enables a variety of applications. To this end, unsupervised representation learning methods such as topic models and word embeddings constitute prominent tools.The goal of this dissertation is to study and address challengingproblems in this area, focusing on both the design of novel text miningalgorithms and tools, as well as on studying how these tools can be applied to text collections written in a single or several languages.In the first part of the thesis we focus on topic models and more precisely on how to incorporate prior information of text structure to such models.Topic models are built on the premise of bag-of-words, and therefore words are exchangeable. While this assumption benefits the calculations of the conditional probabilities it results in loss of information.To overcome this limitation we propose two mechanisms that extend topic models by integrating knowledge of text structure to them. We assume that the documents are partitioned in thematically coherent text segments. The first mechanism assigns the same topic to the words of a segment. The second, capitalizes on the properties of copulas, a tool mainly used in the fields of economics and risk management that is used to model the joint probability density distributions of random variables while having access only to their marginals.The second part of the thesis explores bilingual topic models for comparable corpora with explicit document alignments. Typically, a document collection for such models is in the form of comparable document pairs. The documents of a pair are written in different languages and are thematically similar. Unless translations, the documents of a pair are similar to some extent only. Meanwhile, representative topic models assume that the documents have identical topic distributions, which is a strong and limiting assumption. To overcome it we propose novel bilingual topic models that incorporate the notion of cross-lingual similarity of the documents that constitute the pairs in their generative and inference processes. Calculating this cross-lingual document similarity is a task on itself, which we propose to address using cross-lingual word embeddings.The last part of the thesis concerns the use of word embeddings and neural networks for three text mining applications. First, we discuss polylingual document classification where we argue that translations of a document can be used to enrich its representation. Using an auto-encoder to obtain these robust document representations we demonstrate improvements in the task of multi-class document classification. Second, we explore multi-task sentiment classification of tweets arguing that by jointly training classification systems using correlated tasks can improve the obtained performance. To this end we show how can achieve state-of-the-art performance on a sentiment classification task using recurrent neural networks. The third application we explore is cross-lingual information retrieval. Given a document written in one language, the task consists in retrieving the most similar documents from a pool of documents written in another language. In this line of research, we show that by adapting the transportation problem for the task of estimating document distances one can achieve important improvements

Contemporary knitting over the past decade has experienced a recent resurgence in cultural interest and technical exploration. This research project aims to identify, through personal practice, the implications of knitting as undefined, removed from the boundaries of product. It is the dissolving of the lines between design, art and craft and exploring the domestically machine knitted textile via the use of materials and the inherent qualities of the fabric which are the driving factors of this research. It is through this exploration that my personal and creative process is diversified. The traditional connotations of knitting are historical, social and cultural, in particular hand knitting. Childhood memories of mothers and grandmothers knitting out of necessity, for clothing, often evoke feelings of safety, warmth and comfort. This familiarity of the looped stitches and understanding of the knit as garment binds knitting to fashion. Industrial knitting process, as scale of stitch is reduced, begins to remove this familiarity and creates an anonymity of structure and process, for example jersey knits used for t-shirts. This instant recognition for knitting as clothing is part of the design process where-by knitted fabrics work in unison with product. It is this boundary that has defined my professional practice designing for knitwear. This research involves a more experimental and fluid approach to producing the textile, considering the qualities and potential of the structure as something to celebrate in its own form. Designers such as Issey Miyake, Hussein Chalayan and the artist Rosmarie Trockel have been influential in taking fashion concepts into the gallery, often knitted. This movement of making conceptual and political statements, especially in the case of the industrially knitted pieces by Trockel, was a step to question the traditional and feminist perceptions of knitting and using the process as a material to create art. While these exhibitions explored the knitted textile in the form of fashion garment, the importance of diversifying the knitted cloth and displaying conceptual pieces is a major influence on this research. Also the more recent exhibition 'Radical Lace and Subversive Knitting', (Museum of Arts & Design New York 2007), has allowed for a reinvigorated forum for constructed textiles to be viewed as object, new product or purely as spatial explorations of structure. The impact of these ideas has allowed for the consideration of the textile being stripped back further and to remove the instant connot ation of product application. Exploration of materials, knitted structures and the manipulation of fabric without the constraints of identified product is the impetus of this project. The evolution of the outcomes is instrumental to the reactions of fibres, stitch and interplays of positive and negative space, while suggestions of product are accidental and created by the knitted form as it is removed from the machine. A personal interest in exploiting the knitted structures potential to possess transparency and opacity, become sculptural and changeable by hand have influenced the choices of material and stitch combination. This experimentation has informed my personal practice and the involved process of making.

In 1966, American tour operator, Lindblad Travel, began small-scale tourist cruises to Antarctica. Over the course of the next 50 years, what began as an offbeat travel destination transformed into an iconic tourist attraction. Annual tourist visits to Antarctica grew from a few hundred to tens of thousands; modes of transport to the continent diversified to include yachts, cruise ships, icebreakers and aircraft; and the activities available to Antarctic tourists ranged from one-day scenic flights to multi-month mountaineering expeditions and ski tours to the South Pole. Antarctic tourism numbers trebled in the 1990s, with an influx of Russian ice ships into the tourism fleet. This thesis chronicles that 50-year history of Antarctic tourism growth and diversification. Its narrative centres on the efforts of enterprising tour operators to secure their footing on a physically and politically formidable continent. Government officials and a mounting environmental movement invariably resisted these efforts. And the safety, environmental integrity and self-sufficiency of the industry were challenged in the wake of a series of environmental emergencies. Even so, Antarctic tour operators were successful in forging a robust industry through technical ingenuity and political nous. By underscoring their environmental ethos, and their influential role in raising public awareness of Antarctica, tour operators presented themselves as the responsible stewards of an innocuous practice that was consistent with Antarctica’s governing principles. Each chapter in this 50-year tourism history also offers some insight into the Antarctic tourist imaginary, a theme that is explored further through a series of reflections. These reflections reveal that the Antarctic tourism industry draws strongly on the dominant image of Antarctica as a pristine wilderness, frozen in a perpetual age of heroic exploration. By suppressing its own history, the Antarctic tourism industry strives to maintain a perception of the continent as an enduring blank space available for perpetual discovery. According to this image, the heroic age explorers remain the touchstone of Antarctic experience even now, more than a century after the era’s conclusion. The explorers’ narratives of physical and moral struggle against a relentless environment continue to serve as the benchmark of authentic Antarctic experience. They also inspire the sustained imagining of Antarctica as a masculine sphere for ‘Boys’ Own’ adventure, a legacy most poignantly illuminated in the endeavours of Antarctica’s modern explorers. Such an imagining of Antarctica as pristine and untouched—as a continent apart—is challenged by more recent understandings of Antarctic ice. We have come to realise that the world’s sea level is principally controlled by the state of the Antarctic ice sheet and that we may be destabilising that ice sheet without ever leaving home. These emerging climate change narratives threaten to undermine dominant images of Antarctica as an untouched wilderness frozen in time. For now, tour operators continue to present climate change narratives in a manner which does not fundamentally challenge this wilderness ideal; an ideal which forms the imaginative foundation on which the Antarctic tourism industry has been built.

In 1802, a French scientific expedition under the command of Nicolas Baudin made an uscheduled visit to the British colony at Port Jackson, New South Wales. It was a pivotal episode in the course of Baudin's Australian voyage. The commander had already fulfilled most of his instructions, though imperfectly, and only the north coast of New Holland remained unexamined. He and his men stayed at anchor in Port Jackson for over five months. When they set sail once more, they embarked on what historians agree was a new phase of the expedition. Baudin and his men did not proceed directly to the north coast, but returned to the southern and western coasts, where they perfected and augmented the work in geography and natural history that they had carried out earlier. This thesis examines what occurred during the sojourn at Port Jackson, as well as the circumstances that led up to it, in order to determine in precise terms why and how this episode came to be a turning point in Baudin's voyage. It asks: was the second campaign just an extension of the first or was it an opportunity for Baudin to redefine the voyage? The Port Jackson sojourn thus serves as a site of interrogation regarding the nature of Nicolas Baudin's leadership and the construction, on British colonial territory, of a French scientific voyage. However, the opportunity to gain real insight into the sojourn of the voyagers at Port Jackson has been limited by a perceived scarcity of resources. The fact that Baudin's journal falls silent here has meant that there is no one privileged source of information on the commander's role or on the day-to-day activities of the expeditioners, and that scholars examining this episode have tended to focus on the details of the larger picture rather than on the larger picture itself. This is not to say that the presence of the Baudin expedition in Port Jackson has left no material traces. In fact, there is a diverse range of archival records – expense accounts, correspondence, inventories of specimens, journals kept by officers and savants and the logbooks of the Géographe – from which the day-to-day life of the commander and his men at Port Jackson can be reconstructed. Commencing with an analysis of the events that led up to the sojourn and influenced Baudin's approach to it, this study examines the relationships that Baudin built in the colony, his manner of command aboard the Géographe and the scientific results of the stay. After then analysing the way in which Baudin managed the sojourn and planned the second campaign, we conclude that Baudin did not simply seek to satisfy the expectations of his superiors but in fact he seized this opportunity to create the “perfect” scientific voyage.
Thesis (Ph.D.) -- University of Adelaide, School of Humanities, 2010

Research Doctorate - Doctor of Philosophy (PhD)
Ludwig Leichhardt is synonymous with Australian exploration, yet his achievements extend well beyond the success of his overland expeditions. Beyond exploration, Leichhardt was a passionate observer of Australian natural history, who left a significant legacy of collected and written material, especially in the field of botany. The recent translations of his diaries recorded between 1842 and 1844 have exposed a lesser known period of Leichhardt’s life and helped to evidence him as a capable and diligent scientist. The published materials combined with Leichhardt’s collected plant specimens establish the foundation for my research and have subsequently informed my outcomes. From my research I have painted a series of botanical illustrations depicting specimens that were observed, recorded and collected by Leichhardt more than 170 years ago. The documentation of this research and creative methodology from field observations through to the final illustrations visually depicts Leichhardt’s historical contribution to Australian botanical science while providing information on creative process to botanical illustrators.

In 1802, a French scientific expedition under the command of Nicolas Baudin made an uscheduled visit to the British colony at Port Jackson, New South Wales. It was a pivotal episode in the course of Baudin's Australian voyage. The commander had already fulfilled most of his instructions, though imperfectly, and only the north coast of New Holland remained unexamined. He and his men stayed at anchor in Port Jackson for over five months. When they set sail once more, they embarked on what historians agree was a new phase of the expedition. Baudin and his men did not proceed directly to the north coast, but returned to the southern and western coasts, where they perfected and augmented the work in geography and natural history that they had carried out earlier. This thesis examines what occurred during the sojourn at Port Jackson, as well as the circumstances that led up to it, in order to determine in precise terms why and how this episode came to be a turning point in Baudin's voyage. It asks: was the second campaign just an extension of the first or was it an opportunity for Baudin to redefine the voyage? The Port Jackson sojourn thus serves as a site of interrogation regarding the nature of Nicolas Baudin's leadership and the construction, on British colonial territory, of a French scientific voyage. However, the opportunity to gain real insight into the sojourn of the voyagers at Port Jackson has been limited by a perceived scarcity of resources. The fact that Baudin's journal falls silent here has meant that there is no one privileged source of information on the commander's role or on the day-to-day activities of the expeditioners, and that scholars examining this episode have tended to focus on the details of the larger picture rather than on the larger picture itself. This is not to say that the presence of the Baudin expedition in Port Jackson has left no material traces. In fact, there is a diverse range of archival records – expense accounts, correspondence, inventories of specimens, journals kept by officers and savants and the logbooks of the Géographe – from which the day-to-day life of the commander and his men at Port Jackson can be reconstructed. Commencing with an analysis of the events that led up to the sojourn and influenced Baudin's approach to it, this study examines the relationships that Baudin built in the colony, his manner of command aboard the Géographe and the scientific results of the stay. After then analysing the way in which Baudin managed the sojourn and planned the second campaign, we conclude that Baudin did not simply seek to satisfy the expectations of his superiors but in fact he seized this opportunity to create the “perfect” scientific voyage.
Thesis (Ph.D.) -- University of Adelaide, School of Humanities, 2010

碩士
國立交通大學
光電工程系所
95
We explore the mobilephone camera lens with typical VGA sensor format by global explorer (GE) optimization. Besides that use GE to design the two-element system, we first deduce the basic lens forms as the initial approach. Physically different merit functions have been set to explore how the best performance could be achieved. On the other hand ,we identify the improvement that can be achieved by GE.

Like other animals, humans explore to learn about the world, and exploit what we have learned in order to maximize reward. The trade-off between exploration and exploitation is a widely-studied topic that cuts across multiple domains, including animal ecology, economics, and computer science. This work approaches the explore-exploit dilemma from the perspective of cognitive neuroscience. In particular, how are our decisions to explore or exploit represented computationally? And how is that representation implemented in the brain? Experiment 1 examined neural signals following outcomes in a risk-taking task. Explorations – defined as slower responses – were preceded by an enhancement of the P300, a component of the human event-related brain potential thought to reflect a phasic release of norepinephrine from locus coeruleus. Experiment 2 revealed that the same neural signal precedes feedback in a learning task called a two-armed bandit. There, a reinforcement learning model was used to classify responses as either exploitations or explorations; exploitations were driven by previous rewards, and explorations were not. Experiments 3 and 4 extended these results in three important ways. First, evidence is presented that the neural signal observed in Experiments 1 and 2 was driven not only by the upcoming decision, but also by the preceding decision (perhaps even more so). Second, Experiments 3 and 4 involved increasingly larger action spaces. Experiment 3 involved choosing from among either 4, 9, or 16 options. Experiment 4 involved searching for rewards in continuous two-dimensional map. In both experiments, the feedback-locked P300 was enhanced following exploration. Third, exploitation was the more common strategy in Experiments 1 and 2. Thus, it was unclear whether the exploration-related P300 enhancement observed there was due to exploration per se, to exploration rate, or to the fact that exploration was rare compared to exploitation. Experiment 3 partially address this by eliciting different rates of exploration; the exploration-related P300 effect correlated with rate of exploration. In Experiment 4, exploration was more common than exploitation (in contrast to Experiments 1–3); even so, exploration was followed by a P300 enhancement. Together, Experiments 1–4 suggest the presence of a general neural system related to exploration that operates across multiple task types (discrete to continuous), regardless of whether exploration or exploitation is the more common task strategy. The proposed purpose of this neural signal is to interrupt one mode of decision-making (exploration) in favour of another (exploitation).
Graduate

Mémoire en recherche-création
Le dispositif connu du public sous l'appellation "réalité virtuelle" propose une expérience multisensorielle qui encourage à repenser nos habitudes de perception spectatorielle. Avec le volet recherche, j’élabore une réflexion sur la représentation du réel au cinéma pour mieux cerner le rapport qu’entretient le spectateur avec l’image. Menée dans un souci d’envisager conjointement « récit » et « dispositif », la perspective qui est la nôtre consiste à se pencher sur le processus de collaboration du spectateur et à examiner comment, avec la réalité virtuelle, le « pacte de représentation » et le « cognitivisme spectatoriel » se voient bouleversés. Pour cela, nous élargirons notre étude en nous appuyant sur les aspects techniques de la réalité virtuelle relatifs au photoréalisme et à l’immersion sensorimotrice. Le volet création — qui prend la forme d’un court-métrage en réalité-virtuelle — explore le thème de l’art de la mémoire à partir de l’étude de certains lieux réels qui l’abrite. L’histoire se déroule dix ans après qu’un événement d’origine inconnu ait décimé la population mondiale. Estéban, qui a survécu au mal mystérieux alors qu’il était enfant, entame une exploration des paysages architecturaux désormais en ruine, il parviendra à trouver une passion dans la photographie. Le procédé narratologique de « mise en abyme » utilisé dans ce court-métrage nous fournira une première clé pour ouvrir des pistes vers une réflexion sur la fictionnalisation dans son rapport avec d’autres phénomènes artistiques et représentationnels, notamment la pratique contemporaine appelé « urbex ».
The device known to the public as "virtual reality" offers a multisensory experience that encourages rethinking our habits of spectator perception. With the research component, I develop a reflection on the representation of reality in the cinema to better understand the relationship between the viewer and the image. Conducted with a view to jointly considering "narrative" and "device" our perspective is to look at the process of collaboration of the viewer, and to examine how with virtual reality, the "pact of representation" and the "spectatorial cognitivism" are upset. To do this, we will expand our study by relying on the technical aspects of virtual reality related to photorealism and sensorimotor immersion. The creation component, which takes the form of a short film in virtual reality, will explore the theme of the art of memory from the study of some real places that shelters it. The story takes place 10 years after an event of unknown origin decimated the world's population. Estéban, who survived the mysterious evil as a child, begins an exploration of architectural landscapes now in ruins, he will find a passion in photography. The narratological process of "mise en abyme" used in this short film will provide us with a first key to open avenues towards a reflection on fictionalization in its relationship with other artistic and representational phenomena, notably the contemporary practice called "urbex". .

Relatório de estágio de mestrado em Educação Pré-escolar
Este relatório apresenta o projeto de intervenção pedagógica desenvolvido nos contextos de creche e jardim de infância no âmbito da Unidade Curricular, Prática de Ensino Supervisionada, inserida no plano de estudos do Mestrado em Educação Pré-Escolar, da Universidade do Minho, que permitiu proporcionar às crianças um conjunto de atividades relacionadas com a abordagem ao conhecimento do mundo físico. O projeto de intervenção num e noutro contexto partiu da observação e interação com o grupo de crianças e reflexão com as educadoras cooperantes, estes processos permitiram conhecer e compreender o contexto educativo, identificar os interesses e necessidades das crianças e desenvolver uma intervenção pedagógica intencional, sustentada nos mesmos, assim como, promover um ambiente de aprendizagem ativa. O projeto desenvolvido em ambos os contextos foi resultado dos interesses das crianças, desta forma o projeto visou responder aos mesmos, ampliando a sua curiosidade e desejo de saber mais acerca do mundo físico, através da criação de oportunidades de exploração, experimentação e descoberta, desenvolvendo uma aprendizagem ativa. No jardim de infância as estratégias pedagógicas relacionaram-se com o desenvolvimento de atividades experimentais e a inclusão de uma área das ciências e experiências. As crianças tiveram oportunidade de explorar, manipular e experimentar diversos objetos e materiais e fazer novas descobertas acerca dos fenómenos naturais, favorecendo o interesse e gosto pelas ciências físicas. A intervenção contribuiu para as crianças desenvolverem novos conhecimentos acerca dos fenómenos físicos, assim como, promoveu o desenvolvimento de algumas competências e atitudes ligadas às ciências. Em creche as estratégias de intervenção relacionaram-se com o desenvolvimento de atividades de exploração de materiais e objetos. Às crianças foram proporcionadas atividades de exploração e manipulação que permitiram o contacto com novos e diferentes materiais e objetos, bem como, promoveram a observação atenta e a participação ativa em fenómenos do quotidiano, tornando possível a construção de novos conhecimentos acerca do mundo que as rodeia e apoiar a curiosidade e o desejo de saber acerca do mesmo.
This report presents a pedagogical intervention project developed in the day care and kindergarten context regarding the Practical Curricular, Unit of Supervised Teaching Practice, which is part of the Master’s study plan for Preschool Education in University of Minho. It provided the children with a set of activities related to the approach of physical world knowledge. The intervention project in one and other contexts came from the observation and interaction with the group of children and from the reflection with the cooperating teachers. These processes made it possible to know and understand the educational context, to identify the children´s interests and needs and to develop an intentional pedagogical intervention, based upon the children, and to promote an active learning environment. The project developed in both contexts resulted from the children’s interests, aiming to fulfill them, widening their curiosity and their desire to know more about the physical world, through the creation of exploration opportunities, experiments and discovery, developing an active learning. The pedagogical strategies in kindergarten had to do with the development of experimental activities and the introduction of a science and experiments topic area. The children had the opportunity to explore, manipulate and experiment several objects and materials and to make new discoveries about natural phenomena, increasing the interest and pleasure in physical sciences. The intervention allowed the children to develop new knowledge about physical phenomena, and promoted the development of certain skills and attitudes towards the science. In day care, the intervention strategies had to do with the development of activities related to the exploring of materials and objects. The children were provided with exploration and manipulation activities. These provided contact with new and different materials and objects. They also promoted the careful observation and the active participation in daily phenomena, making the construction of new knowledge of their surrounding world possible, and supporting the curiosity and desire to know more about it.