Semantic Sort: A Supervised Approach to Personalized Semantic Relatedness

We propose and study a novel supervised approach to learning statistical semantic relatedness models from subjectively annotated training examples. The proposed semantic model consists of parameterized co-occurrence statistics associated with textual units of a large background knowledge corpus. We present an efficient algorithm for learning such semantic models from a training sample of relatedness preferences. Our method is corpus independent and can essentially rely on any sufficiently large (unstructured) collection of coherent texts. Moreover, the approach facilitates the fitting of semantic models for specific users or groups of users. We present the results of extensive range of experiments from small to large scale, indicating that the proposed method is effective and competitive with the state-of-the-art.Comment: 37 pages, 8 figures A short version of this paper was already published at ECML/PKDD 201

Learning to Extract Keyphrases from Text

Many academic journals ask their authors to provide a list of about five to fifteen key words, to appear on the first page of each article. Since these key words are often phrases of two or more words, we prefer to call them keyphrases. There is a surprisingly wide variety of tasks for which keyphrases are useful, as we discuss in this paper. Recent commercial software, such as Microsoft?s Word 97 and Verity?s Search 97, includes algorithms that automatically extract keyphrases from documents. In this paper, we approach the problem of automatically extracting keyphrases from text as a supervised learning task. We treat a document as a set of phrases, which the learning algorithm must learn to classify as positive or negative examples of keyphrases. Our first set of experiments applies the C4.5 decision tree induction algorithm to this learning task. The second set of experiments applies the GenEx algorithm to the task. We developed the GenEx algorithm specifically for this task. The third set of experiments examines the performance of GenEx on the task of metadata generation, relative to the performance of Microsoft?s Word 97. The fourth and final set of experiments investigates the performance of GenEx on the task of highlighting, relative to Verity?s Search 97. The experimental results support the claim that a specialized learning algorithm (GenEx) can generate better keyphrases than a general-purpose learning algorithm (C4.5) and the non-learning algorithms that are used in commercial software (Word 97 and Search 97)

Text Summarization Technique for Punjabi Language Using Neural Networks

In the contemporary world, utilization of digital content has risen exponentially. For example, newspaper and web articles, status updates, advertisements etc. have become an integral part of our daily routine. Thus, there is a need to build an automated system to summarize such large documents of text in order to save time and effort. Although, there are summarizers for languages such as English since the work has started in the 1950s and at present has led it up to a matured stage but there are several languages that still need special attention such as Punjabi language. The Punjabi language is highly rich in morphological structure as compared to English and other foreign languages. In this work, we provide three phase extractive summarization methodology using neural networks. It induces compendious summary of Punjabi single text document. The methodology incorporates pre-processing phase that cleans the text; processing phase that extracts statistical and linguistic features; and classification phase. The classification based neural network applies an activation function- sigmoid and weighted error reduction-gradient descent optimization to generate the resultant output summary. The proposed summarization system is applied over monolingual Punjabi text corpus from Indian languages corpora initiative phase-II. The precision, recall and F-measure are achieved as 90.0%, 89.28% an 89.65% respectively which is reasonably good in comparison to the performance of other existing Indian languages" summarizers.This research is partially funded by the Ministry of Economy, Industry and Competitiveness, Spain (CSO2017-86747-R)

Unsupervised learning of Arabic non-concatenative morphology

Unsupervised approaches to learning the morphology of a language play an important role in computer processing of language from a practical and theoretical perspective, due their minimal reliance on manually produced linguistic resources and human annotation. Such approaches have been widely researched for the problem of concatenative affixation, but less attention has been paid to the intercalated (non-concatenative) morphology exhibited by Arabic and other Semitic languages. The aim of this research is to learn the root and pattern morphology of Arabic, with accuracy comparable to manually built morphological analysis systems. The approach is kept free from human supervision or manual parameter settings, assuming only that roots and patterns intertwine to form a word. Promising results were obtained by applying a technique adapted from previous work in concatenative morphology learning, which uses machine learning to determine relatedness between words. The output, with probabilistic relatedness values between words, was then used to rank all possible roots and patterns to form a lexicon. Analysis using trilateral roots resulted in correct root identification accuracy of approximately 86% for inflected words. Although the machine learning-based approach is effective, it is conceptually complex. So an alternative, simpler and computationally efficient approach was then devised to obtain morpheme scores based on comparative counts of roots and patterns. In this approach, root and pattern scores are defined in terms of each other in a mutually recursive relationship, converging to an optimized morpheme ranking. This technique gives slightly better accuracy while being conceptually simpler and more efficient. The approach, after further enhancements, was evaluated on a version of the Quranic Arabic Corpus, attaining a final accuracy of approximately 93%. A comparative evaluation shows this to be superior to two existing, well used manually built Arabic stemmers, thus demonstrating the practical feasibility of unsupervised learning of non-concatenative morphology

Kombinasi Metode Rule-Based dan N-Gram Stemming untuk Mengenali Stemmer Bahasa Bali

Proses untuk mengekstraksi kata dasar dari kata berafiks dikenal dengan istilah stemming yang bertujuan meningkatkan recall dengan mereduksi variasi kata berafiks ke dalam bentuk kata dasarnya. Penelitian terdahulu tentang stemming bahasa Bali pernah dilakukan menggunakan metode rule-based, tapi afiks yang diluluhkan hanya prefiks dan sufiks, sedangkan variasi afiks lain tidak diluluhkan, seperti infiks, konfiks, simulfiks, dan kombinasi afiks. Penelitian tentang stemming menggunakan pendekatan rule-based telah diterapkan di berbagai bahasa yang berbeda. Metode rule-based memiliki kelebihan jika diterapkan pada domain yang sederhana, maka rule-based mudah untuk diverifikasi dan divalidasi, tapi memiliki kelemahan saat diterapkan pada domain dengan level kompleksitas yang tinggi, apabila sistem tidak dapat mengenali rules, maka tidak ada hasil yang diperoleh. Untuk mengatasi kelemahan stemming menggunakan rule-based, kami menggunakan metode n-gram stemming, dimana kata berafiks dan kata dasar diubah ke bentuk n-gram, kemudian tingkat kemiripan antara n-gram kata berafiks dan n-gram kata dasar diukur menggunakan metode dice coefficient, apabila tingkat kemiripannya memenuhi nilai ambang batas yang ditentukan, maka kata dasar yang dibandingkan dengan kata berafiks ditampilkan. Pada penelitian ini, kami mengembangkan metode stemmer yang meluluhkan seluruh variasi afiks pada bahasa Bali dengan mengombinasikan pendekatan rule-based dan metode n-gram stemming. Berdasarkan pengujian yang telah dilakukan untuk kesepuluh query metode yang diusulkan memperoleh rerata akurasi stemming lebih baik 96,67% dari metode terdahulu 75%, sedangkan untuk kelima query metode n-gram stemming dapat mengenali beberapa kata berafiks diluar rules. Penelitian berikutnya, kami akan memperhatikan semantik setiap kata dan tahap validasi menggunakan aplikasi text mining.AbstractA process for extracting a stem word from the inflected word is known as stemming which aims to increase recall by reducing the variation of the inflected word into its stem word form. Previous research on stemming the Balinese language has been done using the rule-based method, but the affixes that are removed are only prefixes and suffixes, while other variations of affixes are not removed, such as infixes, confixes, simulfiks, and combinations of affixes. Research on stemming using the rule-based approach has been applied in a variety of different languages. The rule-based method has advantages when applied to a simple field, rule-based is easy to verify and validate, but has weaknesses when applied to domains with a high level of complexity, if the system cannot recognize rules, no results are obtained. To overcome the stemming weaknesses using rule-based, we use the n-gram stemming method, where the inflected word and stem word are converted to the n-gram form, then the level of similarity between the n-gram of the inflected word and the stem word is measured using the dice coefficient method, when the level of similarity meets the defined threshold value, then the stem word is displayed. In this study, we developed a stemmer method that removes all variations of affixes in the Balinese language by combining the rule-based approach and the n-gram stemming method. Based on the experiments for the ten queries the proposed method get 96,67% stemming accuracy than the previous method 75%, while for the five queries for the n-gram stemming method can recognize some inflected words outside the rules. The next study, we will pay attention to the semantics of each word and the validation stage using text mining application

Self-adaptive GA, quantitative semantic similarity measures and ontology-based text clustering

As the common clustering algorithms use vector space model (VSM) to represent document, the conceptual relationships between related terms which do not co-occur literally are ignored. A genetic algorithm-based clustering technique, named GA clustering, in conjunction with ontology is proposed in this article to overcome this problem. In general, the ontology measures can be partitioned into two categories: thesaurus-based methods and corpus-based methods. We take advantage of the hierarchical structure and the broad coverage taxonomy of Wordnet as the thesaurus-based ontology. However, the corpus-based method is rather complicated to handle in practical application. We propose a transformed latent semantic analysis (LSA) model as the corpus-based method in this paper. Moreover, two hybrid strategies, the combinations of the various similarity measures, are implemented in the clustering experiments. The results show that our GA clustering algorithm, in conjunction with the thesaurus-based and the LSA-based method, apparently outperforms that with other similarity measures. Moreover, the superiority of the GA clustering algorithm proposed over the commonly used k-means algorithm and the standard GA is demonstrated by the improvements of the clustering performance

Learning algorithms for keyphrase extraction

Many academic journals ask their authors to provide a list of about five to fifteen keywords, to appear on the first page of each article. Since these key words are often phrases of two or more words, we prefer to call them keyphrases. There is a wide variety of tasks for which keyphrases are useful, as we discuss in this paper. We approach the problem of automatically extracting keyphrases from text as a supervised learning task. We treat a document as a set of phrases, which the learning algorithm must learn to classify as positive or negative examples of keyphrases. Our first set of experiments applies the C4.5 decision tree induction algorithm to this learning task. We evaluate the performance of nine different configurations of C4.5. The second set of experiments applies the GenEx algorithm to the task. We developed the GenEx algorithm specifically for automatically extracting keyphrases from text. The experimental results support the claim that a custom-designed algorithm (GenEx), incorporating specialized procedural domain knowledge, can generate better keyphrases than a general-purpose algorithm (C4.5). Subjective human evaluation of the keyphrases generated by GenEx suggests that about 80% of the keyphrases are acceptable to human readers. This level of performance should be satisfactory for a wide variety of applications