51 research outputs found
Automatic Image Captioning with Style
This thesis connects two core topics in machine learning, vision
and language. The problem of choice is image caption generation:
automatically constructing natural language descriptions of image
content. Previous research into image caption generation has
focused on generating purely descriptive captions; I focus on
generating visually relevant captions with a distinct linguistic
style. Captions with style have the potential to ease
communication and add a new layer of personalisation.
First, I consider naming variations in image captions, and
propose a method for predicting context-dependent names that
takes into account visual and linguistic information. This method
makes use of a large-scale image caption dataset, which I also
use to explore naming conventions and report naming conventions
for hundreds of animal classes. Next I propose the SentiCap
model, which relies on recent advances in artificial neural
networks to generate visually relevant image captions with
positive or negative sentiment. To balance descriptiveness and
sentiment, the SentiCap model dynamically switches between two
recurrent neural networks, one tuned for descriptive words and
one for sentiment words. As the first published model for
generating captions with sentiment, SentiCap has influenced a
number of subsequent works. I then investigate the sub-task of
modelling styled sentences without images. The specific task
chosen is sentence simplification: rewriting news article
sentences to make them easier to understand.
For this task I design a neural sequence-to-sequence model that
can work with
limited training data, using novel adaptations for word copying
and sharing
word embeddings. Finally, I present SemStyle, a system for
generating visually
relevant image captions in the style of an arbitrary text corpus.
A shared term
space allows a neural network for vision and content planning to
communicate
with a network for styled language generation. SemStyle achieves
competitive
results in human and automatic evaluations of descriptiveness and
style.
As a whole, this thesis presents two complete systems for styled
caption generation that are first of their kind and demonstrate,
for the first time, that automatic style transfer for image
captions is achievable. Contributions also include novel ideas
for object naming and sentence simplification. This thesis opens
up inquiries into highly personalised image captions; large scale
visually grounded concept naming; and more generally, styled text
generation with content control
Tracking the Temporal-Evolution of Supernova Bubbles in Numerical Simulations
The study of low-dimensional, noisy manifolds embedded in a higher dimensional space has been extremely useful in many applications, from the chemical analysis of multi-phase flows to simulations of galactic mergers. Building a probabilistic model of the manifolds has helped in describing their essential properties and how they vary in space. However, when the manifold is evolving through time, a joint spatio-temporal modelling is needed, in order to fully comprehend its nature. We propose a first-order Markovian process that propagates the spatial probabilistic model of a manifold at fixed time, to its adjacent temporal stages. The proposed methodology is demonstrated using a particle simulation of an interacting dwarf galaxy to describe the evolution of a cavity generated by a Supernov
Human Resource Management in Emergency Situations
The dissertation examines the issues related to the human resource management in emergency situations and introduces the measures helping to solve these issues. The prime aim is to analyse complexly a human resource management, built environment resilience management life cycle and its stages for the purpose of creating an effective Human Resource Management in Emergency Situations Model and Intelligent System. This would help in accelerating resilience in every stage, managing personal stress and reducing disaster-related losses.
The dissertation consists of an Introduction, three Chapters, the Conclusions, References, List of Author’s Publications and nine Appendices.
The introduction discusses the research problem and the research relevance, outlines the research object, states the research aim and objectives, overviews the research methodology and the original contribution of the research, presents the practical value of the research results, and lists the defended propositions. The introduction concludes with an overview of the author’s publications and conference presentations on the topic of this dissertation.
Chapter 1 introduces best practice in the field of disaster and resilience management in the built environment. It also analyses disaster and resilience management life cycle ant its stages, reviews different intelligent decision support systems, and investigates researches on application of physiological parameters and their dependence on stress. The chapter ends with conclusions and the explicit objectives of the dissertation.
Chapter 2 of the dissertation introduces the conceptual model of human resource management in emergency situations. To implement multiple criteria analysis of the research object the methods of multiple criteria analysis and mahematics are proposed. They should be integrated with intelligent technologies.
In Chapter 3 the model developed by the author and the methods of multiple criteria analysis are adopted by developing the Intelligent Decision Support System for a Human Resource Management in Emergency Situations consisting of four subsystems: Physiological Advisory Subsystem to Analyse a User’s Post-Disaster Stress Management; Text Analytics Subsystem; Recommender Thermometer for Measuring the Preparedness for Resilience and Subsystem of Integrated Virtual and Intelligent Technologies.
The main statements of the thesis were published in eleven scientific articles: two in journals listed in the Thomson Reuters ISI Web of Science, one in a peer-reviewed scientific journal, four in peer-reviewed conference proceedings referenced in the Thomson Reuters ISI database, and three in peer-reviewed conference proceedings in Lithuania. Five presentations were given on the topic of the dissertation at conferences in Lithuania and other countries
Uticaj klasifikacije teksta na primene u obradi prirodnih jezika
The main goal of this dissertation is to put different text classification tasks in
the same frame, by mapping the input data into the common vector space of linguistic
attributes. Subsequently, several classification problems of great importance for natural
language processing are solved by applying the appropriate classification algorithms.
The dissertation deals with the problem of validation of bilingual translation pairs, so
that the final goal is to construct a classifier which provides a substitute for human evaluation
and which decides whether the pair is a proper translation between the appropriate
languages by means of applying a variety of linguistic information and methods.
In dictionaries it is useful to have a sentence that demonstrates use for a particular dictionary
entry. This task is called the classification of good dictionary examples. In this thesis,
a method is developed which automatically estimates whether an example is good or bad
for a specific dictionary entry.
Two cases of short message classification are also discussed in this dissertation. In the
first case, classes are the authors of the messages, and the task is to assign each message
to its author from that fixed set. This task is called authorship identification. The other
observed classification of short messages is called opinion mining, or sentiment analysis.
Starting from the assumption that a short message carries a positive or negative attitude
about a thing, or is purely informative, classes can be: positive, negative and neutral.
These tasks are of great importance in the field of natural language processing and the
proposed solutions are language-independent, based on machine learning methods: support
vector machines, decision trees and gradient boosting. For all of these tasks, a
demonstration of the effectiveness of the proposed methods is shown on for the Serbian
language.Osnovni cilj disertacije je stavljanje različitih zadataka klasifikacije teksta u
isti okvir, preslikavanjem ulaznih podataka u isti vektorski prostor lingvističkih atributa..
On Clustering and Evaluation of Narrow Domain Short-Test Corpora
En este trabajo de tesis doctoral se investiga el problema del agrupamiento de conjuntos especiales de documentos llamados textos cortos de dominios restringidos.
Para llevar a cabo esta tarea, se han analizados diversos corpora y métodos de agrupamiento. Mas aún, se han introducido algunas medidas de evaluación de corpus, técnicas de selección de términos y medidas para la validez de agrupamiento con la finalidad de estudiar los siguientes problemas:
-Determinar la relativa dificultad de un corpus para ser agrupado y estudiar algunas de sus características como longitud de los textos, amplitud del dominio, estilometría, desequilibrio de clases y estructura.
-Contribuir en el estado del arte sobre el agrupamiento de corpora compuesto de textos cortos de dominios restringidos
El trabajo de investigación que se ha llevado a cabo se encuentra parcialmente enfocado en el "agrupamiento de textos cortos". Este tema se considera relevante dado el modo actual y futuro en que las personas tienden a usar un "lenguaje reducido" constituidos por textos cortos (por ejemplo, blogs, snippets, noticias y generación de mensajes de textos como el correo electrónico y el chat).
Adicionalmente, se estudia la amplitud del dominio de corpora. En este sentido, un corpus puede ser considerado como restringido o amplio si el grado de traslape de vocabulario es alto o bajo, respectivamente. En la tarea de categorización, es bastante complejo lidiar con corpora de dominio restringido tales como artículos científicos, reportes técnicos, patentes, etc.
El objetivo principal de este trabajo consiste en estudiar las posibles estrategias para tratar con los siguientes dos problemas:
a) las bajas frecuencias de los términos del vocabulario en textos cortos, y
b) el alto traslape de vocabulario asociado a dominios restringidos.
Si bien, cada uno de los problemas anteriores es un reto suficientemente alto, cuando se trata con textos cortos de dominios restringidos, la complejidad del problema se incrPinto Avendaño, DE. (2008). On Clustering and Evaluation of Narrow Domain Short-Test Corpora [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/2641Palanci
Application of Common Sense Computing for the Development of a Novel Knowledge-Based Opinion Mining Engine
The ways people express their opinions and sentiments have radically changed in the past few years thanks to the advent of social networks, web communities, blogs, wikis and other online collaborative media. The distillation of knowledge from this huge amount of unstructured information can be a key factor for marketers who want to create an image or identity in the minds of their customers for their product, brand, or organisation. These online social data, however, remain hardly accessible to computers, as they are specifically meant for human consumption. The automatic analysis of online opinions, in fact, involves a deep understanding of natural language text by machines, from which we are still very far.
Hitherto, online information retrieval has been mainly based on algorithms relying on the textual representation of web-pages. Such algorithms are very good at retrieving texts, splitting them into parts, checking the spelling and counting their words. But when it comes to interpreting sentences and extracting meaningful information, their capabilities are known to be very limited. Existing approaches to opinion mining and sentiment analysis, in particular, can be grouped into three main categories: keyword spotting, in which text is classified into categories based on the presence of fairly unambiguous affect words; lexical affinity, which assigns arbitrary words a probabilistic affinity for a particular emotion; statistical methods, which calculate the valence of affective keywords and word co-occurrence frequencies on the base of a large training corpus. Early works aimed to classify entire documents as containing overall positive or negative polarity, or rating scores of reviews.
Such systems were mainly based on supervised approaches relying on manually labelled samples, such as movie or product reviews where the opinionist’s overall positive or negative attitude was explicitly indicated. However, opinions and sentiments do not occur only at document level, nor they are limited to a single valence or target. Contrary or complementary attitudes toward the same topic or multiple topics can be present across the span of a document. In more recent works, text analysis granularity has been taken down to segment and sentence level, e.g., by using presence of opinion-bearing lexical items (single words or n-grams) to detect subjective sentences, or by exploiting association rule mining for a feature-based analysis of product reviews. These approaches, however, are still far from being able to infer the cognitive and affective information associated with natural language as they mainly rely on knowledge bases that are still too limited to efficiently process text at sentence level.
In this thesis, common sense computing techniques are further developed and applied to bridge the semantic gap between word-level natural language data and the concept-level opinions conveyed by these. In particular, the ensemble application of graph mining and multi-dimensionality reduction techniques on two common sense knowledge bases was exploited to develop a novel intelligent engine for open-domain opinion mining and sentiment analysis. The proposed approach, termed sentic computing, performs a clause-level semantic analysis of text, which allows the inference of both the conceptual and emotional information associated with natural language opinions and, hence, a more efficient passage from (unstructured) textual information to (structured) machine-processable data.
The engine was tested on three different resources, namely a Twitter hashtag repository, a LiveJournal database and a PatientOpinion dataset, and its performance compared both with results obtained using standard sentiment analysis techniques and using different state-of-the-art knowledge bases such as Princeton’s WordNet, MIT’s ConceptNet and Microsoft’s Probase. Differently from most currently available opinion mining services, the developed engine does not base its analysis on a limited set of affect words and their co-occurrence frequencies, but rather on common sense concepts and the cognitive and affective valence conveyed by these. This allows the engine to be domain-independent and, hence, to be embedded in any opinion mining system for the development of intelligent applications in multiple fields such as Social Web, HCI and e-health. Looking ahead, the combined novel use of different knowledge bases and of common sense reasoning techniques for opinion mining proposed in this work, will, eventually, pave the way for development of more bio-inspired approaches to the design of natural language processing systems capable of handling knowledge, retrieving it when necessary, making analogies and learning from experience
Application of Common Sense Computing for the Development of a Novel Knowledge-Based Opinion Mining Engine
The ways people express their opinions and sentiments have radically changed in the past few years thanks to the advent of social networks, web communities, blogs, wikis and other online collaborative media. The distillation of knowledge from this huge amount of unstructured information can be a key factor for marketers who want to create an image or identity in the minds of their customers for their product, brand, or organisation. These online social data, however, remain hardly accessible to computers, as they are specifically meant for human consumption. The automatic analysis of online opinions, in fact, involves a deep understanding of natural language text by machines, from which we are still very far.
Hitherto, online information retrieval has been mainly based on algorithms relying on the textual representation of web-pages. Such algorithms are very good at retrieving texts, splitting them into parts, checking the spelling and counting their words. But when it comes to interpreting sentences and extracting meaningful information, their capabilities are known to be very limited. Existing approaches to opinion mining and sentiment analysis, in particular, can be grouped into three main categories: keyword spotting, in which text is classified into categories based on the presence of fairly unambiguous affect words; lexical affinity, which assigns arbitrary words a probabilistic affinity for a particular emotion; statistical methods, which calculate the valence of affective keywords and word co-occurrence frequencies on the base of a large training corpus. Early works aimed to classify entire documents as containing overall positive or negative polarity, or rating scores of reviews.
Such systems were mainly based on supervised approaches relying on manually labelled samples, such as movie or product reviews where the opinionist’s overall positive or negative attitude was explicitly indicated. However, opinions and sentiments do not occur only at document level, nor they are limited to a single valence or target. Contrary or complementary attitudes toward the same topic or multiple topics can be present across the span of a document. In more recent works, text analysis granularity has been taken down to segment and sentence level, e.g., by using presence of opinion-bearing lexical items (single words or n-grams) to detect subjective sentences, or by exploiting association rule mining for a feature-based analysis of product reviews. These approaches, however, are still far from being able to infer the cognitive and affective information associated with natural language as they mainly rely on knowledge bases that are still too limited to efficiently process text at sentence level.
In this thesis, common sense computing techniques are further developed and applied to bridge the semantic gap between word-level natural language data and the concept-level opinions conveyed by these. In particular, the ensemble application of graph mining and multi-dimensionality reduction techniques on two common sense knowledge bases was exploited to develop a novel intelligent engine for open-domain opinion mining and sentiment analysis. The proposed approach, termed sentic computing, performs a clause-level semantic analysis of text, which allows the inference of both the conceptual and emotional information associated with natural language opinions and, hence, a more efficient passage from (unstructured) textual information to (structured) machine-processable data.
The engine was tested on three different resources, namely a Twitter hashtag repository, a LiveJournal database and a PatientOpinion dataset, and its performance compared both with results obtained using standard sentiment analysis techniques and using different state-of-the-art knowledge bases such as Princeton’s WordNet, MIT’s ConceptNet and Microsoft’s Probase. Differently from most currently available opinion mining services, the developed engine does not base its analysis on a limited set of affect words and their co-occurrence frequencies, but rather on common sense concepts and the cognitive and affective valence conveyed by these. This allows the engine to be domain-independent and, hence, to be embedded in any opinion mining system for the development of intelligent applications in multiple fields such as Social Web, HCI and e-health. Looking ahead, the combined novel use of different knowledge bases and of common sense reasoning techniques for opinion mining proposed in this work, will, eventually, pave the way for development of more bio-inspired approaches to the design of natural language processing systems capable of handling knowledge, retrieving it when necessary, making analogies and learning from experience
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