733 research outputs found
Automatic text summarization with Maximal Frequent Sequences
En las últimas dos décadas un aumento exponencial de la información electrónica
ha provocado una gran necesidad de entender rápidamente grandes
volúmenes de información. En este libro se desarrollan los métodos automáticos
para producir un resumen. Un resumen es un texto corto que transmite la información
más importante de un documento o de una colección de documentos. Los
resúmenes utilizados en este libro son extractivos: una selección de las oraciones
más importantes del texto. Otros retos consisten en generar resúmenes de manera
independiente de lenguaje y dominio.
Se describe la identificación de cuatro etapas para generación de resúmenes
extractivos. La primera etapa es la selección de términos, en la que uno tiene
que decidir qué unidades contarÃan como términos individuales. El proceso de
estimación de la utilidad de los términos individuales se llama etapa de pesado
de términos. El siguiente paso se denota como pesado de oraciones, donde todas
las secuencias reciben alguna medida numérica de acuerdo con la utilidad de
términos. Finalmente, el proceso de selección de las oraciones más importantes
se llama selección de oraciones. Los diferentes métodos para generación de resúmenes
extractivos pueden ser caracterizados como representan estas etapas.
En este libro se describe la etapa de selección de términos, en la que la detección
de descripciones multipalabra se realiza considerando Secuencias Frecuentes
Maximales (sfms), las cuales adquieren un significado importante, mientras
Secuencias Frecuentes (sf) no maximales, que son partes de otros sf, no deben
de ser consideradas. En la motivación se consideró costo vs. beneficio: existen
muchas sf no maximales, mientras que la probabilidad de adquirir un significado
importante es baja. De todos modos, las sfms representan todas las sfs en el
modo compacto: todas las sfs podrÃan ser obtenidas a partir de todas las sfms
explotando cada sfm al conjunto de todas sus subsecuencias. Se presentan los nuevos métodos basados en grafos, algoritmos de agrupamiento
y algoritmos genéticos, los cuales facilitan la tarea de generación de
resúmenes de textos. Se ha experimentado diferentes combinaciones de las opciones
de selección de términos, pesado de términos, pesado de oraciones y
selección de oraciones para generar los resúmenes extractivos de textos independientes
de lenguaje y dominio para una colección de noticias. Se ha analizado
algunas opciones basadas en descripciones multipalabra considerándolas en los
métodos de grafos, algoritmos de agrupamiento y algoritmos genéticos. Se han
obtenido los resultados superiores al de estado de arte.
Este libro está dirigido a los estudiantes y cientÃficos del área de LingüÃstica
Computacional, y también a quienes quieren saber sobre los recientes avances en
las investigaciones de generación automática de resúmenes de textos.In the last two decades, an exponential increase in the available electronic information
causes a big necessity to quickly understand large volumes of information.
It raises the importance of the development of automatic methods for
detecting the most relevant content of a document in order to produce a shorter
text. Automatic Text Summarization (ats) is an active research area dedicated to
generate abstractive and extractive summaries not only for a single document, but
also for a collection of documents. Other necessity consists in finding method for
ats in a language and domain independent way.
In this book we consider extractive text summarization for single document
task. We have identified that a typical extractive summarization method consists
in four steps. First step is a term selection where one should decide what units
will count as individual terms. The process of estimating the usefulness of the
individual terms is called term weighting step. The next step denotes as sentence
weighting where all the sentences receive some numerical measure according to
the usefulness of its terms. Finally, the process of selecting the most relevant sentences
calls sentence selection. Different extractive summarization methods can
be characterized how they perform these steps.
In this book, in the term selection step, we describe how to detect multiword
descriptions considering Maximal Frequent Sequences (mfss), which bearing important
meaning, while non-maximal frequent sequences (fss), those that are
parts of another fs, should not be considered. Our additional motivation was
cost vs. benefit considerations: there are too many non-maximal fss while their
probability to bear important meaning is lower. In any case, mfss represent all fss
in a compact way: all fss can be obtained from all mfss by bursting each mfs into
a set of all its subsequences.New methods based on graph algorithms, genetic algorithms, and clustering
algorithms which facilitate the text summarization task are presented. We
have tested different combinations of term selection, term weighting, sentence
weighting and sentence selection options for language-and domain-independent
extractive single-document text summarization on a news report collection. We
analyzed several options based on mfss, considering them with graph, genetic,
and clustering algorithms. We obtained results superior to the existing state-ofthe-
art methods.
This book is addressed for students and scientists of the area of Computational
Linguistics, and also who wants to know recent developments in the area of Automatic
Text Generation of Summaries
Summarizing Text for Indonesian Language by Using Latent Dirichlet Allocation and Genetic Algorithm
The number of documents progressively increases especially for the electronic one. This degrades effectivity and efficiency in managing them. Therefore, it is a must to manage the documents. Automatic text summarization is able to solve by producing text document summaries. The goal of the research is to produce a tool to summarize documents in Bahasa: Indonesian Language. It is aimed to satisfy the user's need of relevant and consistent summaries. The algorithm is based on sentence features scoring by using Latent Dirichlet Allocation and Genetic Algorithm for determining sentence feature weights. It is evaluated by calculating summarization speed, precision, recall, F-measure, and some subjective evaluations. Extractive summaries from the original text documents can represent important information from a single document in Bahasa with faster summarization speed compared to manual process. Best F-measure value is 0,556926 (with precision of 0.53448 and recall of 0.58134) and summary ratio of 30%
Aplikasi Automatic Text Summarizer
The background of this research is information overload which is an effect of ease of information manipulation, storage and distribution. Massive amount of text documents available causes a decline in effectivity and efficiency of an individual when using information. Automatic Text Summarization can solve information overload by producing text document summaries. Purpose of this research is to create an Automatic Text Summarization algorithm and its implementation to create summaries of important information from text documents faster and can satisfy users' needs of relevant and consistent summaries. The algorithm is based on sentence features scoring and Genetic Algorithm for determining sentence feature weights. Implementation consists of training phase (read text input, pre-summarization, summarization, and Genetic Algorithm to produce learned sentence feature weights) and testing phase (read text input, pre-summarization, summarization, and saving summary). The algorithm is evaluated by calculating summarization speed, precision, recall, F-measure, and subjective evaluation. The results are Automatic Text Summarization algorithm which is able to text documents by extracting important sentences which represent contents of original text documents. Conclusions of this research are Automatic Text Summarization algorithm can create extractive summaries which represent important information from a single document in Indonesian with faster summarization speed compared to manual process
Using lexical chains for keyword extraction
Cataloged from PDF version of article.Keywords can be considered as condensed versions of documents and short forms of their summaries. In this paper, the problem of automatic extraction of keywords from documents is treated as a supervised learning task. A lexical chain holds a set of semantically related words of a text and it can be said that a lexical chain represents the semantic content of a portion of the text. Although lexical chains have been extensively used in text summarization, their usage for keyword extraction problem has not been fully investigated. In this paper, a keyword extraction technique that uses lexical chains is described, and encouraging results are obtained. (C) 2007 Elsevier Ltd. All rights reserved
Summarizing Text for Indonesian Language by Using Latent Dirichlet Allocation and Genetic Algorithm
The number of documents progressively increases especially for the electronic one. This degrades effectivity and efficiency in managing them. Therefore, it is a must to manage the documents. Automatic text summarization is able to solve by producing text document summaries. The goal of the research is to produce a tool to summarize documents in Bahasa: Indonesian Language. It is aimed to satisfy the user’s need of relevant and consistent summaries. The algorithm is based on sentence features scoring by using Latent Dirichlet Allocation and Genetic Algorithm for determining sentence feature weights. It is evaluated by calculating summarization speed, precision, recall, F-measure, and some subjective evaluations. Extractive summaries from the original text documents can represent important information from a single document in Bahasa with faster summarization speed compared to manual process. Best F-measure value is 0,556926 (with precision of 0.53448 and recall of 0.58134) and summary ratio of 30%
Coherent Keyphrase Extraction via Web Mining
Keyphrases are useful for a variety of purposes, including summarizing,
indexing, labeling, categorizing, clustering, highlighting, browsing, and
searching. The task of automatic keyphrase extraction is to select keyphrases
from within the text of a given document. Automatic keyphrase extraction makes
it feasible to generate keyphrases for the huge number of documents that do not
have manually assigned keyphrases. A limitation of previous keyphrase
extraction algorithms is that the selected keyphrases are occasionally
incoherent. That is, the majority of the output keyphrases may fit together
well, but there may be a minority that appear to be outliers, with no clear
semantic relation to the majority or to each other. This paper presents
enhancements to the Kea keyphrase extraction algorithm that are designed to
increase the coherence of the extracted keyphrases. The approach is to use the
degree of statistical association among candidate keyphrases as evidence that
they may be semantically related. The statistical association is measured using
web mining. Experiments demonstrate that the enhancements improve the quality
of the extracted keyphrases. Furthermore, the enhancements are not
domain-specific: the algorithm generalizes well when it is trained on one
domain (computer science documents) and tested on another (physics documents).Comment: 6 pages, related work available at http://purl.org/peter.turney
Automatic Generation of Text Summaries - Challenges, proposals and experiments
Los estudiantes e investigadores en el área de procesamiento deenguaje natural, inteligencia artificial, ciencias computacionales y lingüÃstica computacional serán quizá los primeros interesados en este libro. No obstante, también se pretende introducir a público no especializado en esta prometedora área de investigación; por ello, hemos traducido al español algunos tecnicismos y anglicismos, propios de esta disciplina, pero sin dejar de mencionar, en todo momento, su término en inglés para evitar confusiones y lograr que aquellos lectores interesados puedan ampliar sus fuentes de conocimiento.Este libro presenta un método computacional novedoso, a nivel internacional, para la generación automática de resúmenes de texto, pues supera la calidad de los que actualmente se pueden crear. Es decir, es resultado de una investigación que buscó métodos y modelos computacionales lo menos dependientes del lenguaje y dominio
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