235 research outputs found

    An evaluation resource for geographic information retrieval

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    In this paper we present an evaluation resource for geographic information retrieval developed within the Cross Language Evaluation Forum (CLEF). The GeoCLEF track is dedicated to the evaluation of geographic information retrieval systems. The resource encompasses more than 600,000 documents, 75 topics so far, and more than 100,000 relevance judgments for these topics. Geographic information retrieval requires an evaluation resource which represents realistic information needs and which is geographically challenging. Some experimental results and analysis are reported

    Towards the Semantic Text Retrieval for Indonesian

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    Indonesia is the fourth most populous country in the world and the Asosiasi Penyelenggara Jasa Internet Indonesia (Indonesian Internet Service Providers Association) recorded that Indonesian Internet subscribers and users has been growing rapidly every year. These facts should encourage research such as computer linguistic and information retrieval for Indonesian language which in fact has not been extensively investigated. The research aims to investigate the tolerance rough sets model (TRSM) in order to propose a framework for a semantic text retrieval system. The proposed framework is intended for Indonesian language specifically hence we are working with Indonesian corpora and applying tools for Indonesian, e.g. Indonesian stemmer, in all of the studies. Cognitive approach is employed particularly during data preparation and analysis. An extensive collaboration with human experts is significant on creating a new Indonesian corpus suitable for our research. The performance of an ad hoc retrieval system becomes the starting point for further analysis in order to learn and understand more about the process and characteristic of TRSM, despite comparing TRSM with other methods and determining the best solution. The results of this process function as the guidance for computational modeling of some TRSM's tasks and finally the framework of a semantic information retrieval system with TRSM as its heart. In addition to the proposed framework, this thesis proposes three methods based on TRSM, which are the automatic tolerance value generator, thesaurus optimization, and lexicon-based document representation. All methods were developed by the use of our own corpus, namely ICL-corpus, and evaluated by employing an available Indonesian corpus, called Kompas-corpus. The evaluation on the methods achieved satisfactory results, except for the compact document representation method; this last method seems to work only in limited domain

    Overview of the 2005 cross-language image retrieval track (ImageCLEF)

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    The purpose of this paper is to outline efforts from the 2005 CLEF crosslanguage image retrieval campaign (ImageCLEF). The aim of this CLEF track is to explore the use of both text and content-based retrieval methods for cross-language image retrieval. Four tasks were offered in the ImageCLEF track: a ad-hoc retrieval from an historic photographic collection, ad-hoc retrieval from a medical collection, an automatic image annotation task, and a user-centered (interactive) evaluation task that is explained in the iCLEF summary. 24 research groups from a variety of backgrounds and nationalities (14 countries) participated in ImageCLEF. In this paper we describe the ImageCLEF tasks, submissions from participating groups and summarise the main fndings

    A Performance Evaluation of Classifiers Employ Language Dependent Tools for Indonesian Text

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    This paper evaluates the performance of Maximum Entropy (MaxEnt), Support Vector Machine (SVM) and Na¨ıve Bayes (NB) techniques for Indonesian text classification. Performance of MaxEnt and SVM techniques are compared against baseline NB technique. We also investigate the effect of language dependent tools such as Indonesian stemming and stop words removal can have on these techniques for text classification performances. Up to now, there is no experimental report about the effect of Indonesian stemmer on the text classification accuracy. From our experiments, we conclude that maximum entropy performs better than other classifiers in general. Language dependent tools such as stemming and stop words removal have only little effect on the accuracy of text classification. However stemmed approach scored highest average accuracy and due to the dimension reduction of feature vectors used in classification, make this approach is viable step in pre-processing stage

    Current Implementation and Future Prospects of Santi-Morf V.1.0

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    SANTI-Morf (Prihantoro, 2021) is a new morphological analyser for Indonesian. In SANTI-Morf annotation scheme (Prihantoro, 2019), morpheme tokens are linked to their annotations. The tokens are presented in their orthographic and citation forms to allow (allo)morph or morpheme-based searches. Users can also perform retrievals on the basis of formal and functional morphological criteria as SANTI-Morf tagset encodes the analyses of morphemes’ forms (e.g. roots, clitics, affix type) and functions (e.g. passive voice, active voice, adjective degrees, etc.). Currently, the scheme is implemented in Nooj (Silberztein, 2003), a linguistic development environment. It enables users to index and annotate Indonesian texts in their local PC, and later perform searches based on morphological criteria and or tokens defined by the SANTI-Morf scheme. AbstrakSANTI-Morf (Prihantoro, 2021) adalah sebuah program analisis morfologi terbaru untuk bahasa Indonesia. Dalam skema anotasi SANTI-morf (Prihantoro, A new tagset for morphological analysis of Indonesian, 2019), setiap token morfem terhubung dengan anotasinya. Token-token ini direpresentasikan dalam bentuk ortografis dan bentuk sitasi sehingga memungkinkan pengguna untuk melakukan penelusuran berbasis (alo)morf atau morfem. Selain itu, pengguna juga bisa melakukan penelusuran berbasiskan bentuk atau fungsi morfem. Ini karena tagset analitik yang digunakan di SANTI-morf mencakup bentuk (di antaranya: akar, klitik, jenis afiksasi) dan fungsi (di antaranya: aktif, pasif, derajat ajektiva). Saat ini, SANTI-morf diimplementasikan menggunakan NooJ (Silberztein, 2003), sebuah program pengembangan aplikasi linguistik. Pengguna dapat mengindeks dan menganotasi teks berbahasa Indonesia di komputer mereka, dan selanjutnya melakukan penelusuran menggunakan kriteria morfologi dan skema tokenisasi yang digunakan di skema anotasi SANTI-morf

    Effective techniques for Indonesian text retrieval

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    The Web is a vast repository of data, and information on almost any subject can be found with the aid of search engines. Although the Web is international, the majority of research on finding of information has a focus on languages such as English and Chinese. In this thesis, we investigate information retrieval techniques for Indonesian. Although Indonesia is the fourth most populous country in the world, little attention has been given to search of Indonesian documents. Stemming is the process of reducing morphological variants of a word to a common stem form. Previous research has shown that stemming is language-dependent. Although several stemming algorithms have been proposed for Indonesian, there is no consensus on which gives better performance. We empirically explore these algorithms, showing that even the best algorithm still has scope for improvement. We propose novel extensions to this algorithm and develop a new Indonesian stemmer, and show that these can improve stemming correctness by up to three percentage points; our approach makes less than one error in thirty-eight words. We propose a range of techniques to enhance the performance of Indonesian information retrieval. These techniques include: stopping; sub-word tokenisation; and identification of proper nouns; and modifications to existing similarity functions. Our experiments show that many of these techniques can increase retrieval performance, with the highest increase achieved when we use grams of size five to tokenise words. We also present an effective method for identifying the language of a document; this allows various information retrieval techniques to be applied selectively depending on the language of target documents. We also address the problem of automatic creation of parallel corpora --- collections of documents that are the direct translations of each other --- which are essential for cross-lingual information retrieval tasks. Well-curated parallel corpora are rare, and for many languages, such as Indonesian, do not exist at all. We describe algorithms that we have developed to automatically identify parallel documents for Indonesian and English. Unlike most current approaches, which consider only the context and structure of the documents, our approach is based on the document content itself. Our algorithms do not make any prior assumptions about the documents, and are based on the Needleman-Wunsch algorithm for global alignment of protein sequences. Our approach works well in identifying Indonesian-English parallel documents, especially when no translation is performed. It can increase the separation value, a measure to discriminate good matches of parallel documents from bad matches, by approximately ten percentage points. We also investigate the applicability of our identification algorithms for other languages that use the Latin alphabet. Our experiments show that, with minor modifications, our alignment methods are effective for English-French, English-German, and French-German corpora, especially when the documents are not translated. Our technique can increase the separation value for the European corpus by up to twenty-eight percentage points. Together, these results provide a substantial advance in understanding techniques that can be applied for effective Indonesian text retrieval

    Crowdsourcing in developing repository of phrase definition in Bahasa Indonesia

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    Language repository is valuable as a reference in using the language, its preservation, and in developing and implementation of natural language processing algorithms. Bahasa Indonesia is one of natural languages that hardly has repository despite its large number of speakers and previous attempts to build ones. We devised a way to develop repository of phrase definition in Bahasa using a kind of crowdsourcing and investigated its implementation. An application add-on was inserted to an information system that manages final year projects of undergraduate students. The add-on invites students to participate in writing keyword definition and validating definition. Investigation in a period of six months reveals that about 25% of application users take parts into the voluntary activities either as definition writers and/or validators. During the period, about 1200 phrase definitions were added into the repository and in average each definition is validated by two participants. The activity is supported by users that are well aware of the tasks, and have positive perception about the work, despite different reasons that motivate their contribution

    An evaluation resource for Geographical Information Retrieval

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    In this paper we present an evaluation resource for geographic information retrieval developed within the Cross Language Evaluation Forum (CLEF). The GeoCLEF track is dedicated to the evaluation of geographic information retrieval systems. The resource encompasses more than 600,000 documents, 75 topics so far, and more than 100,000 relevance judgments for these topics. Geographic information retrieval requires an evaluation resource which represents realistic information needs and which is geographically challenging. Some experimental results and analysis are reported

    An automatic morphological analysis system for Indonesian

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    This thesis reports the creation of SANTI-morf (Sistem Analisis Teks Indonesia – morfologi), a rule-based system that performs morphological annotation for Indonesian. The system has been built across three stages, namely preliminaries, annotation scheme creation (the linguistic aspect of the project), and system implementation (the computational aspect of the project). The preliminary matters covered include the necessary key concepts in morphology and Natural Language Processing (NLP), as well as a concise description of Indonesian morphology (largely based on the two primary reference grammars of Indonesian, Alwi et al. 1998 and Sneddon et al. 2010, together with work in the linguistic literature on Indonesian morphology (e.g. Kridalaksana 1989; Chaer 2008). As part of this preliminary stage, I created a testbed corpus for evaluation purposes. The design of the testbed is justified by considering the design of existing evaluation corpora, such as the testbed used by the English Constraint Grammar or EngCG system (Voutilanen 1992), the British National Corpus (BNC) 1994 evaluation data , and the training data used by MorphInd (Larasati et al. 2011), a morphological analyser (MA) for Indonesian. The dataset for this testbed was created by narrowing down an existing very large bit unbalanced collection of texts (drawn from the Leipzig corpora; see Goldhahn et al. 2012). The initial collection was reduced to a corpus composed of nine domains following the domain categorisation of the BNC) . A set of texts from each domain, proportional in size, was extracted and combined to form a testbed that complies with the design cited informed by the prior literature. The second stage, scheme creation, involved the creation of a new Morphological Annotation Scheme (MAS) for Indonesian, for use in the SANTI-morf system. First, a review of MASs in different languages (Finnish, Turkish, Arabic, Indonesian) as well as the Universal Dependencies MAS identifies the best practices in the field. From these, 15 design principles for the novel MAS were devised. This MAS consists of a morphological tagset, together with comprehensive justification of the morphological analyses used in the system. It achieves full morpheme-level annotation, presenting each morpheme’s orthographic and citation forms in the defined output, accompanied by robust morphological analyses, both formal and functional; to my knowledge, this is the first MAS of its kind for Indonesian. The MAS’s design is based not only on reference grammars of Indonesian and other linguistic sources, but also on the anticipated needs of researchers and other users of texts and corpora annotated using this scheme of analysis. The new MAS aims at The third stage of the project, implementation, consisted of three parts: a benchmarking evaluation exercise, a survey of frameworks and tools, leading ultimately to the actual implementation and evaluation of SANTI-morf. MorphInd (Larasati et al. 2012) is the prior state-of-the-art MA for Indonesian. That being the case, I evaluated MorphInd’s performance against the aforementioned testbed, both as just5ification of the need for an improved system, and to serve as a benchmark for SANTI-morf. MorphInd scored 93% on lexical coverage and 89% on tagging accuracy. Next, I surveyed existing MAs frameworks and tools. This survey justifies my choice for the rule-based approach (inspired by Koskenniemi’s 1983 Two Level Morphology, and NooJ (Silberztein 2S003) as respectively the framework and the software tool for SANTI-morf. After selection of this approach and tool, the language resources that constitute the SANTI-morf system were created. These are, primarily, a number of lexicons and sets of analysis rules, as well as necessary NooJ system configuration files. SANTI-morf’s 3 lexicon files (in total 86,590 entries) and 15 rule files (in total 659 rules) are organised into four modules, namely the Annotator, the Guesser, the Improver and the Disambiguator. These modules are applied one after another in a pipeline. The Annotator provides initial morpheme-level annotation for Indonesian words by identifying their having been built according to various morphological processes (affixation, reduplication, compounding, and cliticisation). The Guesser ensures that words not covered by the Annotator, because they are not covered by its lexicons, receive best guesses as to the correct analysis from the application of a set of probable but not exceptionless rules. The Improver improves the existing annotation, by adding probable analyses that the Annotator might have missed. Finally, the Disambiguator resolves ambiguities, that is, words for which the earlier elements of the pipeline have generated two or more possible analyses in terms of the morphemes identified or their annotation. NooJ annotations are saved in a binary file, but for evaluation purposes, plain-text output is required. I thus developed a system for data export using an in-NooJ mapping to and from a modified, exportable expression of the MAS, and wrote a small program to enable re-conversion of the output in plain-text format. For purposes of the evaluation, I created a 10,000 -word gold-standard SANTI-morf manually-annotated dataset. The outcome of the evaluation is that SANTI-morf has 100% coverage (because a best-guess analysis is always provided for unrecognised word forms), and 99% precision and recall for the morphological annotations, with a 1% rate of remaining ambiguity in the final output. SANTI-morf is thus shown to present a number of advancements over MorphInd, the state-of-the-art MA for Indonesian, exhibiting more robust annotation and better coverage. Other performance indicators, namely the high precision and recall, make SANTI-morf a concrete advance in the field of automated morphological annotation for Indonesian, and in consequence a substantive contribution to the field of Indonesian linguistics overall

    Smart tourist information points by combining agents, semantics and AI techniques

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    The tourism sector in the province of Teruel (Aragon, Spain) is increasing rapidly. Although the number of domestic and foreign tourists is continuously growing, there are some tourist attractions spread over a wide geographical area, which are only visited by a few people at specific times of the year. Additionally, having human tourist guides everywhere and speaking different languages is unfeasible. An integrated solution based on smart and interactive Embodied Conversational Agents (ECAs) tourist guides combined with ontologies would overcome this problem. This paper presents a smart tourist information points approach which gathers tourism information about Teruel, structured according to a novel lightweight ontology built on OWL (Ontology Web Language), known as TITERIA (Touristic Information of TEruel for Intelligent Agents). Our proposal, which combines TITERIA with the Maxine platform, is capable of responding appropriately to the users thanks to its Artificial Intelligence Modeling Language (AIML) database and the AI techniques added to Maxine. Preliminary results indicate that our prototype is able to inform users about interesting topics, as well as to propose other related information, allowing them to acquire a complete information about any issue. Furthermore, users can directly talk with an artificial actor making communication much more natural and closer
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