624 research outputs found

    Measuring the accuracy of page-reading systems

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    Given a bitmapped image of a page from any document, a page-reading system identifies the characters on the page and stores them in a text file. This OCR-generated text is represented by a string and compared with the correct string to determine the accuracy of this process. The string editing problem is applied to find an optimal correspondence of these strings using an appropriate cost function. The ISRI annual test of page-reading systems utilizes the following performance measures, which are defined in terms of this correspondence and the string edit distance: character accuracy, throughput, accuracy by character class, marked character efficiency, word accuracy, non-stopword accuracy, and phrase accuracy. It is shown that the universe of cost functions is divided into equivalence classes, and the cost functions related to the longest common subsequence (LCS) are identified. The computation of a LCS can be made faster by a linear-time preprocessing step

    Typo handling in searching of Quran verse based on phonetic similarities

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    The Quran search system is a search system that was built to make it easier for Indonesians to find a verse with text by Indonesian pronunciation, this is a solution for users who have difficulty writing or typing Arabic characters. Quran search system with phonetic similarity can make it easier for Indonesian Muslims to find a particular verse.  Lafzi was one of the systems that developed the search, then Lafzi was further developed under the name Lafzi+. The Lafzi+ system can handle searches with typo queries but there are still fewer variations regarding typing error types. In this research Lafzi++, an improvement from previous development to handle typographical error types was carried out by applying typo correction using the autocomplete method to correct incorrect queries and Damerau Levenshtein distance to calculate the edit distance, so that the system can provide query suggestions when a user mistypes a search, either in the form of substitution, insertion, deletion, or transposition. Users can also search easily because they use Latin characters according to pronunciation in Indonesian. Based on the evaluation results it is known that the system can be better developed, this can be seen from the accuracy value in each query that is tested can surpass the accuracy of the previous system, by getting the highest recall of 96.20% and the highest Mean Average Precision (MAP) reaching 90.69%. The Lafzi++ system can improve the previous system

    Automatic Article Commenting: the Task and Dataset

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    Comments of online articles provide extended views and improve user engagement. Automatically making comments thus become a valuable functionality for online forums, intelligent chatbots, etc. This paper proposes the new task of automatic article commenting, and introduces a large-scale Chinese dataset with millions of real comments and a human-annotated subset characterizing the comments' varying quality. Incorporating the human bias of comment quality, we further develop automatic metrics that generalize a broad set of popular reference-based metrics and exhibit greatly improved correlations with human evaluations.Comment: ACL2018; with supplements; Dataset link available in the pape

    Automatic construction of English/Chinese parallel corpus.

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    Li Kar Wing.Thesis (M.Phil.)--Chinese University of Hong Kong, 2001.Includes bibliographical references (leaves 88-96).Abstracts in English and Chinese.ABSTRACT --- p.iACKNOWLEDGEMENTS --- p.vLIST OF TABLES --- p.viiiLIST OF FIGURES --- p.ixCHAPTERSChapter 1. --- INTRODUCTION --- p.1Chapter 1.1 --- Application of corpus-based techniques --- p.2Chapter 1.1.1 --- Machine Translation (MT) --- p.2Chapter 1.1.1.1 --- Linguistic --- p.3Chapter 1.1.1.2 --- Statistical --- p.4Chapter 1.1.1.3 --- Lexicon construction --- p.4Chapter 1.1.2 --- Cross-lingual Information Retrieval (CLIR) --- p.6Chapter 1.1.2.1 --- Controlled vocabulary --- p.6Chapter 1.1.2.2 --- Free text --- p.7Chapter 1.1.2.3 --- Application corpus-based approach in CLIR --- p.9Chapter 1.2 --- Overview of linguistic resources --- p.10Chapter 1.3 --- Written language corpora --- p.12Chapter 1.3.1 --- Types of corpora --- p.13Chapter 1.3.2 --- Limitation of comparable corpora --- p.16Chapter 1.4 --- Outline of the dissertation --- p.17Chapter 2. --- LITERATURE REVIEW --- p.19Chapter 2.1 --- Research in automatic corpus construction --- p.20Chapter 2.2 --- Research in translation alignment --- p.25Chapter 2.2.1 --- Sentence alignment --- p.27Chapter 2.2.2 --- Word alignment --- p.28Chapter 2.3 --- Research in alignment of sequences --- p.33Chapter 3. --- ALIGNMENT AT WORD LEVEL AND CHARACTER LEVEL --- p.35Chapter 3.1 --- Title alignment --- p.35Chapter 3.1.1 --- Lexical features --- p.37Chapter 3.1.2 --- Grammatical features --- p.40Chapter 3.1.3 --- The English/Chinese alignment model --- p.41Chapter 3.2 --- Alignment at word level and character level --- p.42Chapter 3.2.1 --- Alignment at word level --- p.42Chapter 3.2.2 --- Alignment at character level: Longest matching --- p.44Chapter 3.2.3 --- Longest common subsequence(LCS) --- p.46Chapter 3.2.4 --- Applying LCS in the English/Chinese alignment model --- p.48Chapter 3.3 --- Reduce overlapping ambiguity --- p.52Chapter 3.3.1 --- Edit distance --- p.52Chapter 3.3.2 --- Overlapping in the algorithm model --- p.54Chapter 4. --- ALIGNMENT AT TITLE LEVEL --- p.59Chapter 4.1 --- Review of score functions --- p.59Chapter 4.2 --- The Score function --- p.60Chapter 4.2.1 --- (C matches E) and (E matches C) --- p.60Chapter 4.2.2 --- Length similarity --- p.63Chapter 5. --- EXPERIMENTAL RESULTS --- p.69Chapter 5.1 --- Hong Kong government press release articles --- p.69Chapter 5.2 --- Hang Seng Bank economic monthly reports --- p.76Chapter 5.3 --- Hang Seng Bank press release articles --- p.78Chapter 5.4 --- Hang Seng Bank speech articles --- p.81Chapter 5.5 --- Quality of the collections and future work --- p.84Chapter 6. --- CONCLUSION --- p.87Bibliograph

    Sequence queries on temporal graphs

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    Graphs that evolve over time are called temporal graphs. They can be used to describe and represent real-world networks, including transportation networks, social networks, and communication networks, with higher fidelity and accuracy. However, research is still limited on how to manage large scale temporal graphs and execute queries over these graphs efficiently and effectively. This thesis investigates the problems of temporal graph data management related to node and edge sequence queries. In temporal graphs, nodes and edges can evolve over time. Therefore, sequence queries on nodes and edges can be key components in managing temporal graphs. In this thesis, the node sequence query decomposes into two parts: graph node similarity and subsequence matching. For node similarity, this thesis proposes a modified tree edit distance that is metric and polynomially computable and has a natural, intuitive interpretation. Note that the proposed node similarity works even for inter-graph nodes and therefore can be used for graph de-anonymization, network transfer learning, and cross-network mining, among other tasks. The subsequence matching query proposed in this thesis is a framework that can be adopted to index generic sequence and time-series data, including trajectory data and even DNA sequences for subsequence retrieval. For edge sequence queries, this thesis proposes an efficient storage and optimized indexing technique that allows for efficient retrieval of temporal subgraphs that satisfy certain temporal predicates. For this problem, this thesis develops a lightweight data management engine prototype that can support time-sensitive temporal graph analytics efficiently even on a single PC

    Composing Measures for Computing Text Similarity

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    We present a comprehensive study of computing similarity between texts. We start from the observation that while the concept of similarity is well grounded in psychology, text similarity is much less well-defined in the natural language processing community. We thus define the notion of text similarity and distinguish it from related tasks such as textual entailment and near-duplicate detection. We then identify multiple text dimensions, i.e. characteristics inherent to texts that can be used to judge text similarity, for which we provide empirical evidence. We discuss state-of-the-art text similarity measures previously proposed in the literature, before continuing with a thorough discussion of common evaluation metrics and datasets. Based on the analysis, we devise an architecture which combines text similarity measures in a unified classification framework. We apply our system in two evaluation settings, for which it consistently outperforms prior work and competing systems: (a) an intrinsic evaluation in the context of the Semantic Textual Similarity Task as part of the Semantic Evaluation (SemEval) exercises, and (b) an extrinsic evaluation for the detection of text reuse. As a basis for future work, we introduce DKPro Similarity, an open source software package which streamlines the development of text similarity measures and complete experimental setups
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