Search for: computational-linguistics
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    Preposition semantic analysis via Persian text corpus

    , Article Journal of Language and Literature ; Volume 6, Issue 2 , 2015 , Pages 26-33 ; 20780303 (ISSN) Khosravizadeh, P ; Kowsarifard, Z ; Eslami, M ; Sharif University of Technology
    Progress IPS LLC  2015
    Prepositions are considered as frequent linguistic units, whose role in computational linguistics cannot be neglected. These units are often thought to have functional meaning. On the other hand, in some cases, the substitution of one particular preposition with another onewould changethe meaning ofa sentence. This paper argues that prepositions are not meaningless units, which are only used for the purpose of sentence cohesion. The central goal of the research is to show that prepositions are meaning distinguishing elements. In order to achieve this goal, five Persian prepositions are examined in a Persian text corpus. Firstly, 1000 sentences consisting of these prepositions are extracted... 

    Modeling of network security-related behaviours using NVML

    , Article 8th International Multitopic Conference, INMIC 2004, 24 December 2004 through 26 December 2004 ; 2004 , Pages 506-511 ; 0780386809 (ISBN); 9780780386808 (ISBN) Shahriari, H. R ; Jalili, R ; Sharif University of Technology
    Institute of Electrical and Electronics Engineers Inc  2004
    Nowadays, security has become an important issue for organizations especially in e-commerce applications. The spreading of networks and increasing of their complexity has complicated the task of security analysis, therefore automatic approaches have received more attention recently. This paper proposes a model-based approach to analyze the overall security of a network, based on the interaction of hosts within the network. A simple language is introduced far modeling securityrelated behaviours of networks and systems. Using the language, a case study is described and its formal model and security properties are presented. © 2004 IEEE  

    Preposition Semantic Analysis Via Persian Text Corpus

    , M.Sc. Thesis Sharif University of Technology Kowsarifard, Zahra (Author) ; Khosravizadeh, Parvaneh (Supervisor) ; Eslami, Moharram (Co-Advisor)
    Prepositions are considered as frequent linguistic units whose role in computational linguistics cannot be neglected. These units are often thought to have no lexical meaning; moreover, it is a widely held belief that prepositions are solely used for sentence cohesion. On the other hand, in some cases the substitution of one particular preposition with another one would change the meaning of sentences.
    The main question which is concerned in this thesis is “Whether prepositions should be regarded as meaningful units or semantically empty units?” In order to achieve this goal, the present study is conducted as a library research and a field research. In the library research, 1000... 

    Semi-supervised dependency parsing using lexical affinities

    , Article 50th Annual Meeting of the Association for Computational Linguistics, ACL 2012 - Proceedings of the Conference ; Volume 1 , 2012 , Pages 777-785 ; 9781937284244 (ISBN) Mirroshandel, S. A ; Nasr, A ; Le Roux, J ; Baidu; Google; Elsevier; Microsoft Research; Korea Advanced Institute of Science and Technology (KAIST) ; Sharif University of Technology
    Treebanks are not large enough to reliably model precise lexical phenomena. This deficiency provokes attachment errors in the parsers trained on such data. We propose in this paper to compute lexical affinities, on large corpora, for specific lexico-syntactic configurations that are hard to disambiguate and introduce the new information in a parser. Experiments on the French Treebank showed a relative decrease of the error rate of 7.1% Labeled Accuracy Score yielding the best parsing results on this treebank  

    The effect of employing humanoid robots for teaching English on students' anxiety and attitude

    , Article 2014 2nd RSI/ISM International Conference on Robotics and Mechatronics, ICRoM 2014 ; Oct , 2014 , p. 754-759 Alemi, M ; Meghdari, A ; Ghazisaedy, M ; Sharif University of Technology
    This study aims at examining the effect of Robot Assisted language learning (RALL) on the anxiety level and attitude in the English language learning classroom. Forty-six female students who were beginners at the age of 12 participated in this study and were randomly assigned into two groups of RALL (30 students) and non-RALL (16 students). The treatment was given by a teacher accompanied by a humanoid robot assistant for the RALL group. Two questionnaires of anxiety [15] and attitude [19] were utilized to measure the students' anxiety and attitude. The results of descriptive and t-tests indicated that there was lower anxiety and positive attitude towards English learning in the RALL group... 

    A novel fuzzy approach to recognition of online persian handwriting

    , Article 5th International Conference on Intelligent Systems Design and Applications, ISDA '05, Wroclaw, 8 September 2005 through 10 September 2005 ; Volume 2005 , 2005 , Pages 268-273 ; 0769522866 (ISBN); 9780769522869 (ISBN) Baghshah, M. S ; Shouraki, S. B ; Kasaei, S ; Sharif University of Technology
    Fuzzy logic has proved to be a powerful tool to represent imprecise and irregular patterns. This paper presents a novel fuzzy approach for recognizing online Persian (Farsi) handwriting which is also useful for multi-writer environments. In this approach, the representation of handwriting parameters is accomplished by fuzzy linguistic modeling. The representative features are selected to describe the shape of tokens. Fuzzy linguistic terms provide robustness against handwriting variations. The purposed method was run on a database of Persian isolated handwritten characters and achieved a relatively high recognition rate. © 2005 IEEE  

    Pattern Based Relation Extraction on Presian News Articles

    , M.Sc. Thesis Sharif University of Technology Cholmaghani Qaheh, Ali (Author) ; Bahrani, Mohammad (Supervisor) ; Sameti, Hossein (Co-Advisor)
    Relation extraction is known as a main task in information extraction. There are two main approach in this field, rule based and statistical approaches. This thesis applied a rule based relation extraction approach. In this research we tried to recognize Persian syntactic and morphological patterns to extract relation between named entities. At first we annotated a news dataset by person,organization and location named entity tags which is included more than 100 thousand tokens. After that we found there are 1037 relations 2197 candidate relations. Candidate and labled relations extracted between two entities which is located in a clause. These relations are "PERS_PERS-COMMENTING",... 

    Semantic Role Labeling Using Dependency Trees of Persian Sentences

    , M.Sc. Thesis Sharif University of Technology Rezaei Sharifabadi, Morteza (Author) ; Khosravizadeh, Parvaneh (Supervisor)
    A semantic role labeler is a software that takes sentences as inputs and identifies the words or groups which have semantic roles such as Agent, Theme, Source, Instrument etc. The correct identification of semantic rols using computers can improve the quality of many natural language processing tasks such as information extraction, question and answering, text summarization and machine translation.Therefore a considerable amount of research has been carried out on this topic. Semantic role labelers normally use features extracted from the syntactic structure of the input sentences. That is why the syntactic representation used has a prominent role in the system's outcome. The research... 

    Formal verification of temporal questions in the context of query-answering text summarization

    , Article Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics), 28 May 2012 through 30 May 2012 ; Volume 7310 LNAI , May , 2012 , Pages 350-355 ; 03029743 (ISSN) ; 9783642303524 (ISBN) Mostafazadeh, N ; Bakhshandeh Babarsad, O ; Ghassem Sani, G ; Sharif University of Technology
    This paper presents a novel method for answering complex temporal ordering questions in the context of an event and query-based text summarization. This task is accomplished by precisely mapping the problem of "query-based summarization of temporal ordering questions" in the field of Natural Language Processing to "verifying a finite state model against a temporal formula" in the realm of Model Checking. This mapping requires specific definitions, structures, and procedures. The output of this new approach is promisingly a readable and informative summary satisfying the user's needs  

    The Impact of Social Robotics on L2 Learners’ Anxiety and Attitude in English Vocabulary Acquisition

    , Article International Journal of Social Robotics ; Volume 7, Issue 4 , 2015 , Pages 523-535 ; 18754791 (ISSN) Alemi, M ; Meghdari, A ; Ghazisaedy, M ; Sharif University of Technology
    This study aimed to examine the effect of robot assisted language learning (RALL) on the anxiety level and attitude in English vocabulary acquisition amongst Iranian EFL junior high school students. Forty-six female students, who were beginners at the age of 12, participated in this study and were randomly assigned into two groups of RALL (30 students) and non-RALL (16 students). The textbook, the materials, as well as the teacher were the same in the two groups. However in the RALL group, the treatment was given by a teacher accompanied by a humanoid robot assistant. Two questionnaires of anxiety and attitude were utilized to measure the students’ anxiety and attitude (Horwitz et al. 1986;... 

    Deterministic randomness extraction from generalized and distributed santha-vazirani sources

    , Article Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics), 6 July 2015 through 10 July 2015 ; Volume 9134 , 2015 , Pages 143-154 ; 03029743 (ISSN) ; 9783662476710 (ISBN) Beigi, S ; Etesami, O ; Gohari, A ; Sharif University of Technology
    Springer Verlag  2015
    A Santha-Vazirani (SV) source is a sequence of random bits where the conditional distribution of each bit, given the previous bits, can be partially controlled by an adversary. Santha and Vazirani show that deterministic randomness extraction from these sources is impossible. In this paper, we study the generalization of SV sources for nonbinary sequences. We show that unlike the binary case, deterministic randomness extraction in the generalized case is sometimes possible. We present a necessary condition and a sufficient condition for the possibility of deterministic randomness extraction. These two conditions coincide in “non-degenerate” cases. Next, we turn to a distributed setting. In... 

    Nevisa, a Persian continuous speech recognition system

    , Article 13th International Computer Society of Iran Computer Conference on Advances in Computer Science and Engineering, CSICC 2008, Kish Island, 9 March 2008 through 11 March 2008 ; Volume 6 CCIS , 2008 , Pages 485-492 ; 18650929 (ISSN); 3540899847 (ISBN); 9783540899846 (ISBN) Sameti, H ; Veisi, H ; Bahrani, M ; Babaali, B ; Hosseinzadeh, K ; Sharif University of Technology
    In this paper we have reviewed Nevisa Persian speech recognition engine. Nevisa is an HMM-based, large vocabulary speaker-independent continuous speech recognition system. Like most successful recognition systems, MFCC with some modification has been used as speech signal features. It also utilizes a VAD based on signal energy and zero-crossing rate. Maximum likelihood estimation criterion the core of which are the classical segmental k-means and Baum-Welsh algorithms is used for training the acoustic models. The system is based on phoneme modeling and utilizes synchronous beam search based on lexicon tree for decoding the acoustic utterances. Language modeling for Persian has been... 

    Robust parsing for word lattices in continuous speech recognition systems

    , Article 2007 9th International Symposium on Signal Processing and its Applications, ISSPA 2007, Sharjah, 12 February 2007 through 15 February 2007 ; 2007 ; 1424407796 (ISBN); 9781424407798 (ISBN) Momtazi, S ; Sameti, H ; Fazel Zarandi, M ; Bahrani, M ; Sharif University of Technology
    One of the roles of a Natural Language Processing (NLP) model in Continuous Speech Recognition (CSR) systems is to find the best sentence hypothesis by ranking all n-best sentences according to the grammar. This paper describes a robust parsing algorithm for Spoken Language Recognition (SLR) which utilizes a technique that improves the efficiency of parsing. This technique integrates grammatical and statistical approaches, and by using a best-first parsing strategy improves the accuracy of recognition. Preliminary experimental results using a Persian continuous speech recognition system show effective improvements in accuracy with little change in recognition time. The word error rate was... 

    Introduction to the world of Quantum Computers

    , Article 5th IEEE International Conference on Cognitive Informatics, ICCI 2006, Beijing, 17 July 2006 through 19 July 2006 ; Volume 2 , 2006 , Pages 760-764 Jafarpour, S ; Sharif University of Technology
    The world is changing very fast, and so are the ways of communication and computation. This article is about a new communication and information technology based on the principles of the quantum physics. At first we discuss about some fundamental paradigms of Quantum Computers World, and then introducing the basis of quantum computation: "QBit". Afterthat we will explain some magic properties of this atomic QBit including Quantum Measurement, Superposition, Entanglement, etc. Then we introduce Quantum Gates the basic modules of the next generation computers. Their relation with the ordinary logical gates and the properties of some of the most useful quantum gates. And finally, we will have a... 

    A robust voice activity detection based on wavelet transform

    , Article 2nd International Conference on Electrical Engineering, ICEE, Lahore, 25 March 2008 through 26 March 2008 ; 2008 ; 9781424422937 (ISBN) Aghajani, K ; Manzuri, M. T ; Karami, M ; Tayebi, H ; Sharif University of Technology
    Voice activity detection is an important step in some speech processing systems, such as speech recognition, speech enhancement, noise estimation, speech compression ... etc. In this paper a new voice activity detection algorithm based on wavelet transform is proposed. In this algorithm we use the energy in each sub band, and by two methods we extract feature vector from these values. Experimental results demonstrate advantage over different VAD methods. ©2008 IEEE  

    Advanced Pregroup Analysis of Persian Grammar

    , M.Sc. Thesis Sharif University of Technology Ghanbarpour, Reza (Author) ; Ardeshir, Mohammad (Supervisor)
    Pregroups as a mathematical structure, are replacement for Lambek's type caregorial grammar which much used in Computational Linguistics. Because of computational and logical properties of pregroups, we can use them as strong tool to analyse the sentence structure of many natural languages. This kind of analysis has been done for English, French, German, Polish, Italian, Arabic and Japanese. In case of Persian language, analysis of simple and compound sentences structure with simple tense verbs and explicit subjects and objects has been studied. In this M.Sc. thesis, we will extent analysis of Persian sentence structure to sentences with compound tense verbs and implicit subjects and objects... 

    Rule-Based Conversion of Colloquial Texts into Official Texts in Persian

    , M.Sc. Thesis Sharif University of Technology Rajabpur, Mohammad (Author) ; Bahrani, Mohammad (Supervisor)
    In this study, first a set of data was colleted which consisted of colloquial sentences in Persian. Each of these sentences was rendered into standard Persian by native speakers. As a result, a corpus of parallel data including 1698 pairs of sentences was created. Then each colloquial sentence and its formal equivalent were converted into term-frequency vectors and the cosine distance similarity between the two vectors was calculated. Besides the mean and the standard deviation of all cosine distances were obtained. Afterwards the whole set of data was divided into two halves through Stratified randomization so that the two halves resembled each other in terms of cosine distance similarity.... 

    Computational Textual Criticism of Manuscripts' Texts

    , M.Sc. Thesis Sharif University of Technology Ranjbar Chaghakabudi, Vahid (Author) ; Bahrani, Mohammad (Supervisor)
    In this thesis, I try to use methods and algorithms of computational linguistics and natural language processing for textual criticism of Persian manuscripts' texts and design and develop a software based on that. Suggested method in this thesis is comparing all manuscripts' texts with base manuscript's text by Dynamic Time Warping (DTW) algorithm, after definition of base manuscript. Then the same sentences are extracted in different manuscripts and POS tagged as body of corpus of author's style and learned as language model by Hidden Markov Model (HMM). At next stage, due to the textual criticism's rules and using of author stylistics algorithms choose the case which is most similar to the... 

    Corpus-based Analysis of "The Little Prince" and its Translations based on Computational Linguistics

    , M.Sc. Thesis Sharif University of Technology Habibi Kaseb, Sara (Author) ; Rezaei, Saeed (Supervisor) ; Mahmoodi Bakhtiari, Behrooz ($item.subfieldsMap.e)
    Concepts and ideas of a society, formed by its discourse and ideology, are mainly manifested through language. Therefore, language has always been the subject of studies and research of many scholars such as linguists. As the languages of different countries are different, in order to transfer the thoughts of a writer, a deep examination of the source text as well as the translation of the work itself seems to be of much importance. Since translation is not an independent phenomenon and depends on the interpreter's perception, it is in relation with ideological concepts and power like the work itself. In order to be able to examine the structural effects of a work on the foundation of the... 

    A new linguistic steganography scheme based on lexical substitution

    , Article 2014 11th International ISC Conference on Information Security and Cryptology, ISCISC 2014 ; 2014 , pp. 155-160 ; ISBN: 9781479953837 Yajam, H. A ; Mousavi, A. S ; Amirmazlaghani, M ; Sharif University of Technology
    Recent studies in the field of text-steganography shows a promising future for linguistic driven stegosystems. One of the most common techniques in this field is known as lexical substitution which provides the requirements for security and payload capacity. However, the existing lexical substitution schemes need an enormous amount of shared data between sender and receiver which acts as the stego key. In this paper, we propose a novel encoding method to overcome this problem. Our proposed approach preserves the good properties of lexical substitution schemes while it provides short length stego keys and significant robustness against active adversary attacks. We demonstrate high efficiency...