340 research outputs found

    Unsupervised discovery of character dictionaries in animation movies

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    Automatic content analysis of animation movies can enable an objective understanding of character (actor) representations and their portrayals. It can also help illuminate potential markers of unconscious biases and their impact. However, multimedia analysis of movie content has predominantly focused on live-action features. A dearth of multimedia research in this field is because of the complexity and heterogeneity in the design of animated characters-an extremely challenging problem to be generalized by a single method or model. In this paper, we address the problem of automatically discovering characters in animation movies as a first step toward automatic character labeling in these media. Movie-specific character dictionaries can act as a powerful first step for subsequent content analysis at scale. We propose an unsupervised approach which requires no prior information about the characters in a movie. We first use a deep neural network-based object detector that is trained on natural images to identify a set of initial character candidates. These candidates are further pruned using saliency constraints and visual object tracking. A character dictionary per movie is then generated from exemplars obtained by clustering these candidates. We are able to identify both anthropomorphic and nonanthropomorphic characters in a dataset of 46 animation movies with varying composition and character design. Our results indicate high precision and recall of the automatically detected characters compared to human-annotated ground truth, demonstrating the generalizability of our approach

    Domain adaptation in Natural Language Processing

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    Domain adaptation has received much attention in the past decade. It has been shown that domain knowledge is paramount for building successful Natural Language Processing (NLP) applications. To investigate the domain adaptation problem, we conduct several experiments from different perspectives. First, we automatically adapt sentiment dictionaries for predicting the financial outcomes “excess return” and “volatility”. In these experiments, we compare manual adaptation of the domain-general dictionary with automatic adaptation, and manual adaptation with a combination consisting of first manual, then automatic adaptation. We demonstrate that automatic adaptation performs better than manual adaptation, namely the automatically adapted sentiment dictionary outperforms the previous state of the art in predicting excess return and volatility. Furthermore, we perform qualitative and quantitative analyses finding that annotation based on an expert’s a priori belief about a word’s meaning is error-prone – the meaning of a word can only be recognized in the context that it appears in. Second, we develop the temporal transfer learning approach to account for the language change in social media. The language of social media is changing rapidly – new words appear in the vocabulary, and new trends are constantly emerging. Temporal transfer-learning allows us to model these temporal dynamics in the document collection. We show that this method significantly improves the prediction of movie sales from discussions on social media forums. In particular, we illustrate the success of parameter transfer, the importance of textual information for financial prediction, and show that temporal transfer learning can capture temporal trends in the data by focusing on those features that are relevant in a particular time step, i.e., we obtain more robust models preventing overfitting. Third, we compare the performance of various domain adaptation models in low-resource settings, i.e., when there is a lack of large amounts of high-quality training data. This is an important issue in computational linguistics since the success of NLP applications primarily depends on the availability of training data. In real-world scenarios, the data is often too restricted and specialized. In our experiments, we evaluate different domain adaptation methods under these assumptions and find the most appropriate techniques for such a low-data problem. Furthermore, we discuss the conditions under which one approach substantially outperforms the other. Finally, we summarize our work on domain adaptation in NLP and discuss possible future work topics.Die Domänenanpassung hat in den letzten zehn Jahren viel Aufmerksamkeit erhalten. Es hat sich gezeigt, dass das Domänenwissen für die Erstellung erfolgreicher NLP-Anwendungen (Natural Language Processing) von größter Bedeutung ist. Um das Problem der Domänenanpassung zu untersuchen, führen wir mehrere Experimente aus verschiedenen Perspektiven durch. Erstens passen wir Sentimentlexika automatisch an, um die Überschussrendite und die Volatilität der Finanzergebnisse besser vorherzusagen. In diesen Experimenten vergleichen wir die manuelle Anpassung des allgemeinen Lexikons mit der automatischen Anpassung und die manuelle Anpassung mit einer Kombination aus erst manueller und dann automatischer Anpassung. Wir zeigen, dass die automatische Anpassung eine bessere Leistung erbringt als die manuelle Anpassung: das automatisch angepasste Sentimentlexikon übertrifft den bisherigen Stand der Technik bei der Vorhersage der Überschussrendite und der Volatilität. Darüber hinaus führen wir eine qualitative und quantitative Analyse durch und stellen fest, dass Annotationen, die auf der a priori Überzeugung eines Experten über die Bedeutung eines Wortes basieren, fehlerhaft sein können. Die Bedeutung eines Wortes kann nur in dem Kontext erkannt werden, in dem es erscheint. Zweitens entwickeln wir den Ansatz, den wir Temporal Transfer Learning benennen, um den Sprachwechsel in sozialen Medien zu berücksichtigen. Die Sprache der sozialen Medien ändert sich rasant – neue Wörter erscheinen im Vokabular und es entstehen ständig neue Trends. Temporal Transfer Learning ermöglicht es, diese zeitliche Dynamik in der Dokumentensammlung zu modellieren. Wir zeigen, dass diese Methode die Vorhersage von Filmverkäufen aus Diskussionen in Social-Media-Foren erheblich verbessert. In unseren Experimenten zeigen wir (i) den Erfolg der Parameterübertragung, (ii) die Bedeutung von Textinformationen für die finanzielle Vorhersage und (iii) dass Temporal Transfer Learning zeitliche Trends in den Daten erfassen kann, indem es sich auf die Merkmale konzentriert, die in einem bestimmten Zeitschritt relevant sind, d. h. wir erhalten robustere Modelle, die eine Überanpassung verhindern. Drittens vergleichen wir die Leistung verschiedener Domänenanpassungsmodelle in ressourcenarmen Umgebungen, d. h. wenn große Mengen an hochwertigen Trainingsdaten fehlen. Das ist ein wichtiges Thema in der Computerlinguistik, da der Erfolg der NLP-Anwendungen stark von der Verfügbarkeit von Trainingsdaten abhängt. In realen Szenarien sind die Daten oft zu eingeschränkt und spezialisiert. In unseren Experimenten evaluieren wir verschiedene Domänenanpassungsmethoden unter diesen Annahmen und finden die am besten geeigneten Techniken dafür. Darüber hinaus diskutieren wir die Bedingungen, unter denen ein Ansatz den anderen deutlich übertrifft. Abschließend fassen wir unsere Arbeit zur Domänenanpassung in NLP zusammen und diskutieren mögliche zukünftige Arbeitsthemen

    Topic extraction in words networks

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    Conceptual Representations for Computational Concept Creation

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    Computational creativity seeks to understand computational mechanisms that can be characterized as creative. The creation of new concepts is a central challenge for any creative system. In this article, we outline different approaches to computational concept creation and then review conceptual representations relevant to concept creation, and therefore to computational creativity. The conceptual representations are organized in accordance with two important perspectives on the distinctions between them. One distinction is between symbolic, spatial and connectionist representations. The other is between descriptive and procedural representations. Additionally, conceptual representations used in particular creative domains, such as language, music, image and emotion, are reviewed separately. For every representation reviewed, we cover the inference it affords, the computational means of building it, and its application in concept creation.Peer reviewe

    Towards a science of human stories: using sentiment analysis and emotional arcs to understand the building blocks of complex social systems

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    We can leverage data and complex systems science to better understand society and human nature on a population scale through language --- utilizing tools that include sentiment analysis, machine learning, and data visualization. Data-driven science and the sociotechnical systems that we use every day are enabling a transformation from hypothesis-driven, reductionist methodology to complex systems sciences. Namely, the emergence and global adoption of social media has rendered possible the real-time estimation of population-scale sentiment, with profound implications for our understanding of human behavior. Advances in computing power, natural language processing, and digitization of text now make it possible to study a culture\u27s evolution through its texts using a big data lens. Given the growing assortment of sentiment measuring instruments, it is imperative to understand which aspects of sentiment dictionaries contribute to both their classification accuracy and their ability to provide richer understanding of texts. Here, we perform detailed, quantitative tests and qualitative assessments of 6 dictionary-based methods applied to 4 different corpora, and briefly examine a further 20 methods. We show that while inappropriate for sentences, dictionary-based methods are generally robust in their classification accuracy for longer texts. Most importantly they can aid understanding of texts with reliable and meaningful word shift graphs if (1) the dictionary covers a sufficiently large enough portion of a given text\u27s lexicon when weighted by word usage frequency; and (2) words are scored on a continuous scale. Our ability to communicate relies in part upon a shared emotional experience, with stories often following distinct emotional trajectories, forming patterns that are meaningful to us. By classifying the emotional arcs for a filtered subset of 4,803 stories from Project Gutenberg\u27s fiction collection, we find a set of six core trajectories which form the building blocks of complex narratives. We strengthen our findings by separately applying optimization, linear decomposition, supervised learning, and unsupervised learning. For each of these six core emotional arcs, we examine the closest characteristic stories in publication today and find that particular emotional arcs enjoy greater success, as measured by downloads. Within stories lie the core values of social behavior, rich with both strategies and proper protocol, which we can begin to study more broadly and systematically as a true reflection of culture. Of profound scientific interest will be the degree to which we can eventually understand the full landscape of human stories, and data driven approaches will play a crucial role. Finally, we utilize web-scale data from Twitter to study the limits of what social data can tell us about public health, mental illness, discourse around the protest movement of #BlackLivesMatter, discourse around climate change, and hidden networks. We conclude with a review of published works in complex systems that separately analyze charitable donations, the happiness of words in 10 languages, 100 years of daily temperature data across the United States, and Australian Rules Football games

    Motion capture data processing, retrieval and recognition.

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    Character animation plays an essential role in the area of featured film and computer games. Manually creating character animation by animators is both tedious and inefficient, where motion capture techniques (MoCap) have been developed and become the most popular method for creating realistic character animation products. Commercial MoCap systems are expensive and the capturing process itself usually requires an indoor studio environment. Procedural animation creation is often lacking extensive user control during the generation progress. Therefore, efficiently and effectively reusing MoCap data can brings significant benefits, which has motivated wider research in terms of machine learning based MoCap data processing. A typical work flow of MoCap data reusing can be divided into 3 stages: data capture, data management and data reusing. There are still many challenges at each stage. For instance, the data capture and management often suffer from data quality problems. The efficient and effective retrieval method is also demanding due to the large amount of data being used. In addition, classification and understanding of actions are the fundamental basis of data reusing. This thesis proposes to use machine learning on MoCap data for reusing purposes, where a frame work of motion capture data processing is designed. The modular design of this framework enables motion data refinement, retrieval and recognition. The first part of this thesis introduces various methods used in existing motion capture processing approaches in literature and a brief introduction of relevant machine learning methods used in this framework. In general, the frameworks related to refinement, retrieval, recognition are discussed. A motion refinement algorithm based on dictionary learning will then be presented, where kinematical structural and temporal information are exploited. The designed optimization method and data preprocessing technique can ensure a smooth property for the recovered result. After that, a motion refinement algorithm based on matrix completion is presented, where the low-rank property and spatio-temporal information is exploited. Such model does not require preparing data for training. The designed optimization method outperforms existing approaches in regard to both effectiveness and efficiency. A motion retrieval method based on multi-view feature selection is also proposed, where the intrinsic relations between visual words in each motion feature subspace are discovered as a means of improving the retrieval performance. A provisional trace-ratio objective function and an iterative optimization method are also included. A non-negative matrix factorization based motion data clustering method is proposed for recognition purposes, which aims to deal with large scale unsupervised/semi-supervised problems. In addition, deep learning models are used for motion data recognition, e.g. 2D gait recognition and 3D MoCap recognition. To sum up, the research on motion data refinement, retrieval and recognition are presented in this thesis with an aim to tackle the major challenges in motion reusing. The proposed motion refinement methods aim to provide high quality clean motion data for downstream applications. The designed multi-view feature selection algorithm aims to improve the motion retrieval performance. The proposed motion recognition methods are equally essential for motion understanding. A collection of publications by the author of this thesis are noted in publications section
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