Ancient Coin Classification Using Graph Transduction Games

Recognizing the type of an ancient coin requires theoretical expertise and years of experience in the field of numismatics. Our goal in this work is automatizing this time consuming and demanding task by a visual classification framework. Specifically, we propose to model ancient coin image classification using Graph Transduction Games (GTG). GTG casts the classification problem as a non-cooperative game where the players (the coin images) decide their strategies (class labels) according to the choices made by the others, which results with a global consensus at the final labeling. Experiments are conducted on the only publicly available dataset which is composed of 180 images of 60 types of Roman coins. We demonstrate that our approach outperforms the literature work on the same dataset with the classification accuracy of 73.6% and 87.3% when there are one and two images per class in the training set, respectively

Unsupervised Domain Adaptation using Graph Transduction Games

Unsupervised domain adaptation (UDA) amounts to assigning class labels to the unlabeled instances of a dataset from a target domain, using labeled instances of a dataset from a related source domain. In this paper, we propose to cast this problem in a game-theoretic setting as a non-cooperative game and introduce a fully automatized iterative algorithm for UDA based on graph transduction games (GTG). The main advantages of this approach are its principled foundation, guaranteed termination of the iterative algorithms to a Nash equilibrium (which corresponds to a consistent labeling condition) and soft labels quantifying the uncertainty of the label assignment process. We also investigate the beneficial effect of using pseudo-labels from linear classifiers to initialize the iterative process. The performance of the resulting methods is assessed on publicly available object recognition benchmark datasets involving both shallow and deep features. Results of experiments demonstrate the suitability of the proposed game-theoretic approach for solving UDA tasks.Comment: Oral IJCNN 201

Studio di fenomeni dinamici di rilevanza in catalisi attraverso l'utilizzo del sistema modello FE/TiOx/Pt(111)

This thesis is about the study of the SMSI effect on model catalysts such as Fe/TiOx/Pt (111). The study has involved the use of techniques such as TPD (Thermal Programmed Desorption), XPS (Xray Photoelectron Spectroscopy), LEED (Low Energy Electron Diffraction) and STM (Scanning Tunnelling Microscopy).openTESI.3644La copia a stampa della tesi e' disponibile presso la biblioteca con la collocazione indicat

L'AMBIENTE NELLA COSTITUZIONE ITALIANA: DALLE DISPOSIZIONI ALLE NORME, SECONDO LA GIURISPRUDENZA COSTITUZIONALE

openT.DOR.15/16.5C

A stable graph-based representation for object recognition through high-order matching

Many Object recognition techniques perform some flavour of point pattern matching between a model and a scene. Such points are usually selected through a feature detection algorithm that is robust to a class of image transformations and a suitable descriptor is computed over them in order to get a reliable matching. Moreover, some approaches take an additional step by casting the correspondence problem into a matching between graphs defined over feature points. The motivation is that the relational model would add more discriminative power, however the overall effectiveness strongly depends on the ability to build a graph that is stable with respect to both changes in the object appearance and spatial distribution of interest points. In fact, widely used graph-based representations, have shown to suffer some limitations, especially with respect to changes in the Euclidean organization of the feature points. In this paper we introduce a technique to build relational structures over corner points that does not depend on the spatial distribution of the features

Transductive Visual Verb Sense Disambiguation

Verb Sense Disambiguation is a well-known task in NLP, the aim is to find the correct sense of a verb in a sentence. Recently, this problem has been extended in a multimodal scenario, by exploiting both textual and visual features of ambiguous verbs leading to a new problem, the Visual Verb Sense Disambiguation (VVSD). Here, the sense of a verb is assigned considering the content of an image paired with it rather than a sentence in which the verb appears. Annotating a dataset for this task is more complex than textual disambiguation, because assigning the correct sense to a pair of requires both non-trivial linguistic and visual skills. In this work, differently from the literature, the VVSD task will be performed in a transductive semi-supervised learning (SSL) setting, in which only a small amount of labeled information is required, reducing tremendously the need for annotated data. The disambiguation process is based on a graph-based label propagation method which takes into account mono or multimodal representations for pairs. Experiments have been carried out on the recently published dataset VerSe, the only available dataset for this task. The achieved results outperform the current state-of-the-art by a large margin while using only a small fraction of labeled samples per sens

A educação do corpo na formação do actor conectar-se com o corpo

Projecto de Intervenção apresentado à Escola Superior de Educação de Lisboa para obtenção de grau de mestre em Educação Artística, na especialização de Teatro na EducaçãoExiste a necessidade de uma rigorosa e constante exploração das técnicas e saberes necessários para a aprendizagem da arte dramática, assim como a de desenvolver competências artísticas e profissionais nos alunos, de forma a prepará-los para as suas carreiras. Este estudo pretende responder a essas necessidades, trazendo à superfície, a partir do projecto realizado na disciplina de Movimento, outras carências emergentes, pessoais, físicas e emocionais de adolescentes em fase de crescimento. O conhecimento do corpo e das suas potencialidades como instrumento de expressão pessoal e cénica e a sua utilização de uma forma consciente e criativa norteou este projecto. Utilizando uma metodologia de Investigação-Acção e apoiando-nos nos conceitos e exigências de mestres formadores da arte dramática, encontrámos em Laban um intermediário capaz de fornecer os instrumentos adequados para empreender esta complexa tarefa de colocar o corpo do actor ao serviço do personagem, indicando-nos caminhos viáveis para a superação de limitações, com estratégias e linhas reguladoras explícitas e claramente identificáveis em todas as fases do processo exploratório. - Abstract There is a need for a rigorous and constant search for the techniques and knowledge required for the apprenticeship of dramatic arts, and also to develop artistic and professional skills in students, in order to fit them for their careers. The present work aims to respond to this need, bringing to the surface other emerging issues, such as personal, physical and emotional ones, concerning adolescents on a growing up process; educating the body, knowing it, enabling the student to use it as his own instrument of personal and scenic expression, in a sentient and creative way, through a project developed in Movement Class. Based upon concepts and demands from master educators in dramatic arts, we found Laban to be one intermediary, capable of providing the adequate tools to enable the accomplishment of this complex task, placing the actor inside the character’s body, showing us viable ways to overcome limitations, with explicit strategies and regulatory lines, clearly identifiable throughout all stages of the process. Keywords

Evidence for moving breathers in a layered crystal insulator at 300K

We report the ejection of atoms at a crystal surface caused by energetic breathers which have travelled more than 10^7 unit cells in atomic chain directions. The breathers were created by bombardment of a crystal face with heavy ions. This effect was observed at 300K in the layered crystal muscovite, which has linear chains of atoms for which the surrounding lattice has C_2 symmetry. The experimental techniques described could be used to study breathers in other materials and configurations.Comment: 7 pages, 3 figure

Ice Core Science Meets Computer Vision: Challenges and Perspectives

Polar ice cores play a central role in studies of the earth's climate system through natural archives. A pressing issue is the analysis of the oldest, highly thinned ice core sections, where the identification of paleoclimate signals is particularly challenging. For this, state-of-the-art imaging by laser-ablation inductively-coupled plasma mass spectrometry (LA-ICP-MS) has the potential to be revolutionary due to its combination of micron-scale 2D chemical information with visual features. However, the quantitative study of record preservation in chemical images raises new questions that call for the expertise of the computer vision community. To illustrate this new inter-disciplinary frontier, we describe a selected set of key questions. One critical task is to assess the paleoclimate significance of single line profiles along the main core axis, which we show is a scale-dependent problem for which advanced image analysis methods are critical. Another important issue is the evaluation of post-depositional layer changes, for which the chemical images provide rich information. Accordingly, the time is ripe to begin an intensified exchange between the two scientific communities of computer vision and ice core science. The collaborative building of a new framework for investigating high-resolution chemical images with automated image analysis techniques will also benefit the already wide-spread application of laser-ablation inductively-coupled plasma mass spectrometry chemical imaging in the geosciences