言語学的特徴を用いた述部の正規化と同義性判定

京都大学0048新制・課程博士博士(情報学)甲第17991号情博第513号新制||情||91(附属図書館)80835京都大学大学院情報学研究科知能情報学専攻(主査)教授 黒橋 禎夫, 教授 石田 亨, 教授 河原 達也学位規則第4条第1項該当Doctor of InformaticsKyoto UniversityDFA

Extracting Synonyms from Bilingual Dictionaries

We present our progress in developing a novel algorithm to extract synonyms from bilingual dictionaries. Identification and usage of synonyms play a significant role in improving the performance of information access applications. The idea is to construct a translation graph from translation pairs, then to extract and consolidate cyclic paths to form bilingual sets of synonyms. The initial evaluation of this algorithm illustrates promising results in extracting Arabic-English bilingual synonyms. In the evaluation, we first converted the synsets in the Arabic WordNet into translation pairs (i.e., losing word-sense memberships). Next, we applied our algorithm to rebuild these synsets. We compared the original and extracted synsets obtaining an F-Measure of 82.3% and 82.1% for Arabic and English synsets extraction, respectively.Comment: In Proceedings - 11th International Global Wordnet Conference (GWC2021). Global Wordnet Association (2021

Automatic Concept Extraction in Semantic Summarization Process

The Semantic Web offers a generic infrastructure for interchange, integration and creative reuse of structured data, which can help to cross some of the boundaries that Web 2.0 is facing. Currently, Web 2.0 offers poor query possibilities apart from searching by keywords or tags. There has been a great deal of interest in the development of semantic-based systems to facilitate knowledge representation and extraction and content integration [1], [2]. Semantic-based approach to retrieving relevant material can be useful to address issues like trying to determine the type or the quality of the information suggested from a personalized environment. In this context, standard keyword search has a very limited effectiveness. For example, it cannot filter for the type of information, the level of information or the quality of information. Potentially, one of the biggest application areas of content-based exploration might be personalized searching framework (e.g., [3],[4]). Whereas search engines provide nowadays largely anonymous information, new framework might highlight or recommend web pages related to key concepts. We can consider semantic information representation as an important step towards a wide efficient manipulation and retrieval of information [5], [6], [7]. In the digital library community a flat list of attribute/value pairs is often assumed to be available. In the Semantic Web community, annotations are often assumed to be an instance of an ontology. Through the ontologies the system will express key entities and relationships describing resources in a formal machine-processable representation. An ontology-based knowledge representation could be used for content analysis and object recognition, for reasoning processes and for enabling user-friendly and intelligent multimedia content search and retrieval. Text summarization has been an interesting and active research area since the 60’s. The definition and assumption are that a small portion or several keywords of the original long document can represent the whole informatively and/or indicatively. Reading or processing this shorter version of the document would save time and other resources [8]. This property is especially true and urgently needed at present due to the vast availability of information. Concept-based approach to represent dynamic and unstructured information can be useful to address issues like trying to determine the key concepts and to summarize the information exchanged within a personalized environment. In this context, a concept is represented with a Wikipedia article. With millions of articles and thousands of contributors, this online repository of knowledge is the largest and fastest growing encyclopedia in existence. The problem described above can then be divided into three steps: • Mapping of a series of terms with the most appropriate Wikipedia article (disambiguation). • Assigning a score for each item identified on the basis of its importance in the given context. • Extraction of n items with the highest score. Text summarization can be applied to many fields: from information retrieval to text mining processes and text display. Also in personalized searching framework text summarization could be very useful. The chapter is organized as follows: the next Section introduces personalized searching framework as one of the possible application areas of automatic concept extraction systems. Section three describes the summarization process, providing details on system architecture, used methodology and tools. Section four provides an overview about document summarization approaches that have been recently developed. Section five summarizes a number of real-world applications which might benefit from WSD. Section six introduces Wikipedia and WordNet as used in our project. Section seven describes the logical structure of the project, describing software components and databases. Finally, Section eight provides some consideration..

Detection of Slang Words in e-Data using semi- Supervised Learning

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Question Paraphrase Generation for Question Answering System

The queries to a practical Question Answering (QA) system range from keywords, phrases, badly written questions, and occasionally grammatically perfect questions. Among different kinds of question analysis approaches, the pattern matching works well in analyzing such queries. It is costly to build this pattern matching module because tremendous manual labor is needed to expand its coverage to so many variations in natural language questions. This thesis proposes that the costly manual labor should be saved by the technique of paraphrase generation which can automatically generate semantically similar paraphrases of a natural language question. Previous approaches of paraphrase generation either require large scale of corpus and the dependency parser, or only deal with the relation-entity type of simple question queries. By introducing a method of inferring transformation operations between paraphrases, and a description of sentence structure, this thesis develops a paraphrase generation method and its implementation in Chinese with very limited amount of corpus. The evaluation results of this implementation show its ability to aid humans to efficiently create a pattern matching module for QA systems as it greatly outperforms the human editors in the coverage of natural language questions, with an acceptable precision in generated paraphrases

Context Aware Textual Entailment

In conversations, stories, news reporting, and other forms of natural language, understanding requires participants to make assumptions (hypothesis) based on background knowledge, a process called entailment. These assumptions may then be supported, contradicted, or refined as a conversation or story progresses and additional facts become known and context changes. It is often the case that we do not know an aspect of the story with certainty but rather believe it to be the case; i.e., what we know is associated with uncertainty or ambiguity. In this research a method has been developed to identify different contexts of the input raw text along with specific features of the contexts such as time, location, and objects. The method includes a two-phase SVM classifier along with a voting mechanism in the second phase to identify the contexts. Rule-based algorithms were utilized to extract the context elements. This research also develops a new context˗aware text representation. This representation maintains semantic aspects of sentences, as well as textual contexts and context elements. The method can offer both graph representation and First-Order-Logic representation of the text. This research also extracts a First-Order Logic (FOL) and XML representation of a text or series of texts. The method includes entailment using background knowledge from sources (VerbOcean and WordNet), with resolution of conflicts between extracted clauses, and handling the role of context in resolving uncertain truth

Event structures in knowledge, pictures and text

This thesis proposes new techniques for mining scripts. Scripts are essential pieces of common sense knowledge that contain information about everyday scenarios (like going to a restaurant), namely the events that usually happen in a scenario (entering, sitting down, reading the menu...), their typical order (ordering happens before eating), and the participants of these events (customer, waiter, food...). Because many conventionalized scenarios are shared common sense knowledge and thus are usually not described in standard texts, we propose to elicit sequential descriptions of typical scenario instances via crowdsourcing over the internet. This approach overcomes the implicitness problem and, at the same time, is scalable to large data collections. To generalize over the input data, we need to mine event and participant paraphrases from the textual sequences. For this task we make use of the structural commonalities in the collected sequential descriptions, which yields much more accurate paraphrases than approaches that do not take structural constraints into account. We further apply the algorithm we developed for event paraphrasing to parallel standard texts for extracting sentential paraphrases and paraphrase fragments. In this case we consider the discourse structure in a text as a sequential event structure. As for event paraphrasing, the structure-aware paraphrasing approach clearly outperforms systems that do not consider discourse structure. As a multimodal application, we develop a new resource in which textual event descriptions are grounded in videos, which enables new investigations on action description semantics and a more accurate modeling of event description similarities. This grounding approach also opens up new possibilities for applying the computed script knowledge for automated event recognition in videos.Die vorliegende Dissertation schlägt neue Techniken zur Berechnung von Skripten vor. Skripte sind essentielle Teile des Allgemeinwissens, die Informationen über alltägliche Szenarien (wie im Restaurant essen) enthalten, nämlich die Ereignisse, die typischerweise in einem Szenario vorkommen (eintreten, sich setzen, die Karte lesen...), deren typische zeitliche Abfolge (man bestellt bevor man isst), und die Teilnehmer der Ereignisse (ein Gast, der Kellner, das Essen,...). Da viele konventionalisierte Szenarien implizit geteiltes Allgemeinwissen sind und üblicherweise nicht detailliert in Texten beschrieben werden, schlagen wir vor, Beschreibungen von typischen Szenario-Instanzen durch sog. “Crowdsourcing” über das Internet zu sammeln. Dieser Ansatz löst das Implizitheits-Problem und lässt sich gleichzeitig zu großen Daten-Sammlungen hochskalieren. Um über die Eingabe-Daten zu generalisieren, müssen wir in den Text-Sequenzen Paraphrasen für Ereignisse und Teilnehmer finden. Hierfür nutzen wir die strukturellen Gemeinsamkeiten dieser Sequenzen, was viel präzisere Paraphrasen-Information ergibt als Standard-Ansätze, die strukturelle Einschränkungen nicht beachten. Die Techniken, die wir für die Ereignis-Paraphrasierung entwickelt haben, wenden wir auch auf parallele Standard-Texte an, um Paraphrasen auf Satz-Ebene sowie Paraphrasen-Fragmente zu extrahieren. Hier betrachten wir die Diskurs-Struktur eines Textes als sequentielle Ereignis-Struktur. Auch hier liefert der strukturell informierte Ansatz klar bessere Ergebnisse als herkömmliche Systeme, die Diskurs-Struktur nicht in die Berechnung mit einbeziehen. Als multimodale Anwendung entwickeln wir eine neue Ressource, in der Text-Beschreibungen von Ereignissen mittels zeitlicher Synchronisierung in Videos verankert sind. Dies ermöglicht neue Ansätze für die Erforschung der Semantik von Ereignisbeschreibungen, und erlaubt außerdem die Modellierung treffenderer Ereignis-Ähnlichkeiten. Dieser Schritt der visuellen Verankerung von Text in Videos eröffnet auch neue Möglichkeiten für die Anwendung des berechneten Skript-Wissen bei der automatischen Ereigniserkennung in Videos