Minimally supervised induction of morphology through bitexts

textA knowledge of morphology can be useful for many natural language processing systems. Thus, much effort has been expended in developing accurate computational tools for morphology that lemmatize, segment and generate new forms. The most powerful and accurate of these have been manually encoded, such endeavors being without exception expensive and time-consuming. There have been consequently many attempts to reduce this cost in the development of morphological systems through the development of unsupervised or minimally supervised algorithms and learning methods for acquisition of morphology. These efforts have yet to produce a tool that approaches the performance of manually encoded systems. Here, I present a strategy for dealing with morphological clustering and segmentation in a minimally supervised manner but one that will be more linguistically informed than previous unsupervised approaches. That is, this study will attempt to induce clusters of words from an unannotated text that are inflectional variants of each other. Then a set of inflectional suffixes by part-of-speech will be induced from these clusters. This level of detail is made possible by a method known as alignment and transfer (AT), among other names, an approach that uses aligned bitexts to transfer linguistic resources developed for one language–the source language–to another language–the target. This approach has a further advantage in that it allows a reduction in the amount of training data without a significant degradation in performance making it useful in applications targeted at data collected from endangered languages. In the current study, however, I use English as the source and German as the target for ease of evaluation and for certain typlogical properties of German. The two main tasks, that of clustering and segmentation, are approached as sequential tasks with the clustering informing the segmentation to allow for greater accuracy in morphological analysis. While the performance of these methods does not exceed the current roster of unsupervised or minimally supervised approaches to morphology acquisition, it attempts to integrate more learning methods than previous studies. Furthermore, it attempts to learn inflectional morphology as opposed to derivational morphology, which is a crucial distinction in linguistics.Linguistic

Advanced Searching Algorithms and its Behavior on Text Structures

This research investigates the behavior of the Boyer-Moore-Horspool (BMH) and the Boyer-Moore-Raita (BMR) string-matching algorithms using multilingual texts. The performance is computed based on searching for patterns in master strings. Experiments are conducted using a number of pattern lengths with many experiments repetition. The experimental results show that on average the number of comparisons per character passed in the case of the BMR is less than the number encountered by the BMH variant. The improvement is due to properties of the text structures. These experiments may lead to more theoretical and practical studies to develop new variants of algorithms. Using multilingual text structures provide more insight into the theory and structure of algorithms as multilingual text structures have different set of characters and dependencies, and the character properties have different type of structures. Since many applications of today depend on searching algorithms, therefore researchers need to explore every possibility that lead to improving the efficiency of searching and matching mechanisms. The time performance of exact string pattern matching can be greatly improved if an efficient algorithm is used. Considering, for example, the growing amount of text handled in the electronic patient records, it is worth and essential, in these cases and others, to searching for an efficient algorithm to deal with such huge items of information. Keywords: Matching, Boyer-Moore, Raita algorithm, Searching, multilingua

An enhanced automatic speech recognition system for Arabic

International audienceAutomatic speech recognition for Arabic is a very challenging task. Despite all the classical techniques for Automatic Speech Recognition (ASR), which can be efficiently applied to Arabic speech recognition , it is essential to take into consideration the language specificities to improve the system performance. In this article, we focus on Modern Standard Arabic (MSA) speech recognition. We introduce the challenges related to Arabic language, namely the complex morphology nature of the language and the absence of the short vowels in written text, which leads to several potential vowelization for each graphemes, which is often conflicting. We develop an ASR system for MSA by using Kaldi toolkit. Several acoustic and language models are trained. We obtain a Word Error Rate (WER) of 14.42 for the baseline system and 12.2 relative improvement by rescoring the lattice and by rewriting the output with the right hamoza above or below Alif

Arabic Information Retrieval: A Relevancy Assessment Survey

The paper presents a research in Arabic Information Retrieval (IR). It surveys the impact of statistical and morphological analysis of Arabic text in improving Arabic IR relevancy. We investigated the contributions of Stemming, Indexing, Query Expansion, Text Summarization (TS), Text Translation, and Named Entity Recognition (NER) in enhancing the relevancy of Arabic IR. Our survey emphasizing on the quantitative relevancy measurements provided in the surveyed publications. The paper shows that the researchers achieved significant enhancements especially in building accurate stemmers, with accuracy reaches 97%, and in measuring the impact of different indexing strategies. Query expansion and Text Translation showed positive relevancy effect. However, other tasks such as NER and TS still need more research to realize their impact on Arabic IR

Arabic statistical language modeling

International audienceIn this study we propose to investigate statistical language models for Arabic. Several experiments using different smoothing techniques have been carried out on a small corpus extracted from a daily newspaper. The sparseness of the data leads us to investigate other solutions without increasing the size of the corpus. A word segmentation technique has been employed in order to increase the statistical viability of the corpus. This leads to a better performance in terms of normalized perplexity

An AI-inspired intelligent agent/student architecture to combine language resources research and teaching

This paper describes experimental use of the multi-agent architecture to integrate Natural Language and Information Systems research and teaching, by casting a group of students as intelligent agents to collect and analyse English language resources from around the world. Section 2 and section 3 describe the hybrid intelligent information systems experiments at the University of Leeds and the results generated, including several research papers accepted at international conferences, and a finalist entry in the British Computer Society Machine Intelligence contest. Our proposals for applying the multi-agent idea in other universities such as the Arab Open University are presented in section 4. The conclusion is presented in section 5: the success of hybrid intelligent information systems experiments in generating research papers within a limited time

An Intelligent Framework for Natural Language Stems Processing

This work describes an intelligent framework that enables the derivation of stems from inflected words. Word stemming is one of the most important factors affecting the performance of many language applications including parsing, syntactic analysis, speech recognition, retrieval systems, medical systems, tutoring systems, biological systems,…, and translation systems. Computational stemming is essential for dealing with some natural language processing such as Arabic Language, since Arabic is a highly inflected language. Computational stemming is an urgent necessity for dealing with Arabic natural language processing. The framework is based on logic programming that creates a program to enabling the computer to reason logically. This framework provides information on semantics of words and resolves ambiguity. It determines the position of each addition or bound morpheme and identifies whether the inflected word is a subject, object, or something else. Position identification (expression) is vital for enhancing understandability mechanisms. The proposed framework adapts bi-directional approaches. It can deduce morphemes from inflected words or it can build inflected words from stems. The proposed framework handles multi-word expressions and identification of names. The framework is based on definiteclause grammar where rules are built according to Arabic patterns (templates) using programming language prolog as predicates in first-order logic. This framework is based on using predicates in firstorder logic with object-oriented programming convention which can address problems of complexity. This complexity of natural language processing comes from the huge amount of storage required. This storage reduces the efficiency of the software system. In order to deal with this complexity, the research uses Prolog as it is based on efficient and simple proof routines. It has dynamic memory allocation of automatic garbage collection. This facility, in addition to relieve th