285 research outputs found
An educational ontology-based M-learning system
Smart devices applications can assist young children in improving their learning capabilities and comprehension skills. However most of learning applications are built without taking into consideration the effective needs and background of Arab users. They are somehow incompatible with their local environment and culture. We propose in this paper a mobile-based educational system that displays illustrations automatically to characterize the content of children' stories on animal domain, and we use some intelligent technique to answer users' questions using an educational ontology. The generation of illustrations passes through different phases which include text processing, extraction of word-to-word relationships, building and accessing an ontology, and using Internet search engines for retrieval of complimentary information. The system can be used also by instructors to teach the children in a nonconventional manner. They can customize semantically the structure of the questions and determine how the answers will be displayed. In order to customize questions and answers, we have defined a semantic infrastructure to define the logic of terms, and the workflow of answers. The aim of our system is to improve the children educational skills to grasp vocabulary and grammar using multimedia with a portable smart device which includes observation, comprehension, realization, and deduction. Children will then be able to continue learning outside the limited time of their schools and from any location.Scopu
AR2SPARQL: An Arabic Natural Language Interface for the Semantic Web
With the growing interest in supporting the Arabic language on the Semantic Web (SW), there is an emerging need to enable Arab users to query ontologies and RDF stores without being challenged with the formal logic of the SW. In the domain of English language, several efforts provided Natural Language (NL) interfaces to enable ordinary users to query ontologies using NL queries. However, none of these efforts were designed to support the Arabic language which has different morphological and semantic structures.
As a step towards supporting Arabic Question Answering (QA) on the SW, this work presents AR2SPARQL, a NL interface that takes questions expressed in Arabic and returns answers drawn from an ontology-based knowledge base. The core of AR2SPARQL is the approach we propose to translate Arabic questions into triples which are matched against RDF data to retrieve an answer. The system uses both linguistic and semantic features to resolve ambiguity when matching words to the ontology content. To overcome the limited support for Arabic Natural Language Processing (NLP), the system does not make intensive use of sophisticated linguistic methods. Instead, it relies more on the knowledge defined in the ontology and the grammar rules we define to capture the structures of Arabic questions and to construct an adequate RDF representations. AR2SPARQL has been tested with two different datasets and results have shown that it achieves a good retrieval performance in terms of precision and recall
An Ontology based Text-to-Picture Multimedia m-Learning System
Multimedia Text-to-Picture is the process of building mental representation from words associated with images. From the research aspect, multimedia instructional message items are illustrations of material using words and pictures that are designed to promote user realization. Illustrations can be presented in a static form such as images, symbols, icons, figures, tables, charts, and maps; or in a dynamic form such as animation, or video clips. Due to the intuitiveness and vividness of visual illustration, many text to picture systems have been proposed in the literature like, Word2Image, Chat with Illustrations, and many others as discussed in the literature review chapter of this thesis. However, we found that some common limitations exist in these systems, especially for the presented images. In fact, the retrieved materials are not fully suitable for educational purposes. Many of them are not context-based and didn’t take into consideration the need of learners (i.e., general purpose images). Manually finding the required pedagogic images to illustrate educational content for learners is inefficient and requires huge efforts, which is a very challenging task. In addition, the available learning systems that mine text based on keywords or sentences selection provide incomplete pedagogic illustrations. This is because words and their semantically related terms are not considered during the process of finding illustrations. In this dissertation, we propose new approaches based on the semantic conceptual graph and semantically distributed weights to mine optimal illustrations that match Arabic text in the children’s story domain. We combine these approaches with best keywords and sentences selection algorithms, in order to improve the retrieval of images matching the Arabic text. Our findings show significant improvements in modelling Arabic vocabulary with the most meaningful images and best coverage of the domain in discourse. We also develop a mobile Text-to-Picture System that has two novel features, which are (1) a conceptual graph visualization (CGV) and (2) a visual illustrative assessment. The CGV shows the relationship between terms associated with a picture. It enables the learners to discover the semantic links between Arabic terms and improve their understanding of Arabic vocabulary. The assessment component allows the instructor to automatically follow up the performance of learners. Our experiments demonstrate the efficiency of our multimedia text-to-picture system in enhancing the learners’ knowledge and boost their comprehension of Arabic vocabulary
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Leveraging Text-to-Scene Generation for Language Elicitation and Documentation
Text-to-scene generation systems take input in the form of a natural language text and output a 3D scene illustrating the meaning of that text. A major benefit of text-to-scene generation is that it allows users to create custom 3D scenes without requiring them to have a background in 3D graphics or knowledge of specialized software packages. This contributes to making text-to-scene useful in scenarios from creative applications to education. The primary goal of this thesis is to explore how we can use text-to-scene generation in a new way: as a tool to facilitate the elicitation and formal documentation of language. In particular, we use text-to-scene generation (a) to assist field linguists studying endangered languages; (b) to provide a cross-linguistic framework for formally modeling spatial language; and (c) to collect language data using crowdsourcing. As a side effect of these goals, we also explore the problem of multilingual text-to-scene generation, that is, systems for generating 3D scenes from languages other than English.
The contributions of this thesis are the following. First, we develop a novel tool suite (the WordsEye Linguistics Tools, or WELT) that uses the WordsEye text-to-scene system to assist field linguists with eliciting and documenting endangered languages. WELT allows linguists to create custom elicitation materials and to document semantics in a formal way. We test WELT with two endangered languages, Nahuatl and Arrernte. Second, we explore the question of how to learn a syntactic parser for WELT. We show that an incremental learning method using a small number of annotated dependency structures can produce reasonably accurate results. We demonstrate that using a parser trained in this way can significantly decrease the time it takes an annotator to label a new sentence with dependency information. Third, we develop a framework that generates 3D scenes from spatial and graphical semantic primitives. We incorporate this system into the WELT tools for creating custom elicitation materials, allowing users to directly manipulate the underlying semantics of a generated scene. Fourth, we introduce a deep semantic representation of spatial relations and use this to create a new resource, SpatialNet, which formally declares the lexical semantics of spatial relations for a language. We demonstrate how SpatialNet can be used to support multilingual text-to-scene generation. Finally, we show how WordsEye and the semantic resources it provides can be used to facilitate elicitation of language using crowdsourcing
Current trends
Deep parsing is the fundamental process aiming at the representation of the syntactic
structure of phrases and sentences. In the traditional methodology this process is
based on lexicons and grammars representing roughly properties of words and interactions
of words and structures in sentences. Several linguistic frameworks, such as Headdriven
Phrase Structure Grammar (HPSG), Lexical Functional Grammar (LFG), Tree Adjoining
Grammar (TAG), Combinatory Categorial Grammar (CCG), etc., offer different
structures and combining operations for building grammar rules. These already contain
mechanisms for expressing properties of Multiword Expressions (MWE), which, however,
need improvement in how they account for idiosyncrasies of MWEs on the one
hand and their similarities to regular structures on the other hand. This collaborative
book constitutes a survey on various attempts at representing and parsing MWEs in the
context of linguistic theories and applications
Representation and parsing of multiword expressions
This book consists of contributions related to the definition, representation and parsing of MWEs. These reflect current trends in the representation and processing of MWEs. They cover various categories of MWEs such as verbal, adverbial and nominal MWEs, various linguistic frameworks (e.g. tree-based and unification-based grammars), various languages including English, French, Modern Greek, Hebrew, Norwegian), and various applications (namely MWE detection, parsing, automatic translation) using both symbolic and statistical approaches
Can humain association norm evaluate latent semantic analysis?
This paper presents the comparison of word association norm created by a psycholinguistic experiment to association lists generated by algorithms operating on text corpora. We compare lists generated by Church and Hanks algorithm and lists generated by LSA algorithm. An argument is presented on how those automatically generated lists reflect real semantic relations
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A hybrid NLP & semantic knowledgebase approach for the intelligent exploration of Arabic documents
In the contemporary era, a colossal amount of information is published daily on the Web in the form of articles, documents, reviews, blogs and social media posts. As most of this data is available in the form of unstructured documents, it makes it challenging and timeconsuming to extract non-trivial, previously unknown, and potentially useful knowledge from the published documents. Hence, extracting useful knowledge from unstructured text, i.e., Information Extraction, is becoming an increasingly significant aspect of knowledge discovery.
This work focuses on Information Extraction form Arabic unstructured text, which is an especially challenging task as Arabic is a highly inflectional and derivational language. The problem is compounded by the lack of mature tools and advanced research in Arabic Natural Language Processing (NLP) in comparison to European languages for instance.
The principal objective of this research work is presenting a comprehensive methodology for integrating domain knowledge with Natural Language Processing techniques that were proven effective in solving most classification problems in order to improve the Information extraction process form online unstructured data. The importance of NLP tools lies in that they play a key role in allowing semantic concept tagging of unstructured text, and so realize the Semantic Web. This work presents a novel rule-based approach that uses linguistic grammar-based techniques to extract Arabic composite names from Arabic text. Our approach uniquely exploits the genitive Arabic grammar rules; in particular, the rules regarding the identification of definite nouns (معرفة) and indefinite nouns (نكرة) to support the process of extracting composite names. Furthermore, this approach does not place any constraints on the length of the Arabic composite name. The results of our experiments show that there are improvement in recognizing Arabic composite names entity in the Arabic language text.
Our research also contributes a novel, knowledge-based approach to relation extraction from unstructured Arabic text, which is based on the principles of Functional Discourse Grammar (FDG). We further improve the approach by integrating it with Machine Learning relation classification, resulting in a hybrid relation extraction algorithm that can handle especially complex Arabic sentence structures. The accuracy of our relation classification efforts was extensively evaluated by means of experimental evaluation that evidenced the accuracy of the FDG relation extraction approach and the improvement gained by the Machine Learning integration.
The essential NLP algorithms of entity recognition and relation extraction were deployed in a Semantic Knowledge-base that was built from the outset to model the knowledge of the problem domain. The semantic modelling of the knowledgebase aided improving the accuracy of the NLP algorithms by leveraging relevant domain knowledge published in Open Linked Datasets. Moreover, the extracted information was semantically tagged and inserted into the Semantic Knowledge-base, which facilitated building advanced rules to infer new interesting information from the extracted knowledge as well as utilising advanced query mechanisms for intelligently exploring the mined problem domain knowledge
A graph-based framework for data retrieved from criminal-related documents
A digitalização das empresas e dos serviços tem potenciado o tratamento e análise de um crescente volume
de dados provenientes de fontes heterogeneas, com desafios emergentes, nomeadamente ao nível da representação
do conhecimento. Também os Órgãos de Polícia Criminal (OPC) enfrentam o mesmo desafio,
tendo em conta o volume de dados não estruturados, provenientes de relatórios policiais, sendo analisados
manualmente pelo investigadores criminais, consumindo tempo e recursos.
Assim, a necessidade de extrair e representar os dados não estruturados existentes em documentos relacionados
com o crime, de uma forma automática, permitindo a redução da análise manual efetuada pelos
investigadores criminais. Apresenta-se como um desafio para a ciência dos computadores, dando a possibilidade
de propor uma alternativa computacional que permita extrair e representar os dados, adaptando
ou propondo métodos computacionais novos.
Actualmente existem vários métodos computacionais aplicados ao domínio criminal, nomeadamente a identificação
e classificação de entidades nomeadas, por exemplo narcóticos, ou a extracção de relações entre
entidades relevantes para a investigação criminal. Estes métodos são maioritariamente aplicadas à lingua
inglesa, e em Portugal não há muita atenção à investigação nesta área, inviabilizando a sua aplicação no
contexto da investigação criminal.
Esta tese propõe uma solução integrada para a representação dos dados não estruturados existentes em
documentos, usando um conjunto de métodos computacionais: Preprocessamento de Documentos, que
agrupa uma tarefa de Extracção, Transformação e Carregamento adaptado aos documentos relacionados
com o crime, seguido por um pipeline de Processamento de Linguagem Natural aplicado à lingua portuguesa,
para uma análise sintática e semântica dos dados textuais; Método de Extracção de Informação 5W1H
que agrupa métodos de Reconhecimento de Entidades Nomeadas, a detecção da função semântica e a
extracção de termos criminais; Preenchimento da Base de Dados de Grafos e Enriquecimento, permitindo
a representação dos dados obtidos numa base de dados de grafos Neo4j. Globalmente a solução integrada apresenta resultados promissores, cujos resultados foram validados usando
protótipos desemvolvidos para o efeito. Demonstrou-se ainda a viabilidade da extracção dos dados não
estruturados, a sua interpretação sintática e semântica, bem como a representação na base de dados de
grafos; Abstract:
The digitalization of companies processes has enhanced the treatment and analysis of a growing volume
of data from heterogeneous sources, with emerging challenges, namely those related to knowledge representation.
The Criminal Police has similar challenges, considering the amount of unstructured data from
police reports manually analyzed by criminal investigators, with the corresponding time and resources.
There is a need to automatically extract and represent the unstructured data existing in criminal-related
documents and reduce the manual analysis by criminal investigators. Computer science faces a challenge
to apply emergent computational models that can be an alternative to extract and represent the data using
new or existing methods.
A broad set of computational methods have been applied to the criminal domain, such as the identification
and classification named-entities (NEs) or extraction of relations between the entities that are relevant for
the criminal investigation, like narcotics. However, these methods have mainly been used in the English
language. In Portugal, the research on this domain, applying computational methods, lacks related works,
making its application in criminal investigation unfeasible.
This thesis proposes an integrated solution for the representation of unstructured data retrieved from
documents, using a set of computational methods, such as Preprocessing Criminal-Related Documents
module. This module is supported by Extraction, Transformation, and Loading tasks. Followed by a
Natural Language Processing pipeline applied to the Portuguese language, for syntactic and semantic
analysis of textual data. Next, the 5W1H Information Extraction Method combines the Named-Entity
Recognition, Semantic Role Labelling, and Criminal Terms Extraction tasks. Finally, the Graph Database
Population and Enrichment allows us the representation of data retrieved into a Neo4j graph database.
Globally, the framework presents promising results that were validated using prototypes developed for this
purpose. In addition, the feasibility of extracting unstructured data, its syntactic and semantic interpretation,
and the graph database representation has also been demonstrated
Proceedings
Proceedings of the Ninth International Workshop
on Treebanks and Linguistic Theories.
Editors: Markus Dickinson, Kaili Müürisep and Marco Passarotti.
NEALT Proceedings Series, Vol. 9 (2010), 268 pages.
© 2010 The editors and contributors.
Published by
Northern European Association for Language
Technology (NEALT)
http://omilia.uio.no/nealt .
Electronically published at
Tartu University Library (Estonia)
http://hdl.handle.net/10062/15891
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