# Collocation methods

Xem 1-20 trên 29 kết quả Collocation methods
• ### Legendre spectral-collocation method for solving some types of fractional optimal control problems

In this paper, the Legendre spectral-collocation method was applied to obtain approximate solutions for some types of fractional optimal control problems (FOCPs). The fractional derivative was described in the Caputo sense. Two different approaches were presented, in the first approach, necessary optimality conditions in terms of the associated Hamiltonian were approximated. In the second approach, the state equation was discretized first using the trapezoidal rule for the numerical integration followed by the Rayleigh–Ritz method to evaluate both the state and control variables.

• ### Septic B-spline collocation method spline collocation method spline collocation method for numerical solution of the mGRLW equation

In this paper, numerical solution of a modified generalized regularized long wave (mGRLW) equation are obtained by a new method based on collocation of septic B – splines. Applying the von – Neumann stability analysis, the proposed method is shown to be unconditionally stable.

• ### Numerical approach for solving space fractional order diffusion equations using shifted Chebyshev polynomials of the fourth kind

In this paper, a new approach for solving space fractional order diffusion equations is proposed. The fractional derivative in this problem is in the Caputo sense. This approach is based on shifted Chebyshev polynomials of the fourth kind with the collocation method.

• ### An exponential method to solve linear Fredholm–Volterra integro-differential equations and residual improvement

In this paper, a collocation approach based on exponential polynomials is introduced to solve linear Fredholm–Volterra integro-differential equations under the initial boundary conditions. In addition, the results are compared with the results of other methods.

• ### Integral equation methods for pricing perpetual bermudan options

This paper develops integral equation methods to the pricing problems of perpetual Bermudan options. By mathematical derivation, the optimal exercise boundary of perpetual Bermudan options can be determined by an integral-form nonlinear equation which can be solved by a root-finding algorithm. With the computational value of optimal exercise, the price of perpetual Bermudan options is written by a Fredholm integral equation.

• ### Báo cáo khoa học: "Large Scale Collocation Data and Their Application to Japanese Word Processor Technology"

Word processors or computers used in Japan employ Japanese input method through keyboard stroke combined with Kana (phonetic) character to Kanji (ideographic, Chinese) character conversion technology. The key factor of Kana-to-Kanji conversion technology is how to raise the accuracy of the conversion through the homophone processing, since we have so many homophonic Kanjis. In this paper, we report the results of our Kana-to-Kanji conversion experiments which embody the homophone processing based on large scale collocation data. ...

• ### MA thesis in English language: An investigation into common errors related to collocations with “make” and “do” by EFL students at Van Lam high school in Hung Yen province

The thesis consists of five main parts: The first chapter gives reasons for choosing the thesis, scope and aims of the study as well as the research method and the structure of the study, this chapter both reviews some previous studies related to the research area of the thesis and provides theoretical background to the concerning matters, in the third chapter, the methodology of the thesis including research-governing principles and research methods are introduced,...

• ### Báo cáo khoa học: "An Extensive Empirical Study of Collocation Extraction Methods"

This paper presents a status quo of an ongoing research study of collocations – an essential linguistic phenomenon having a wide spectrum of applications in the ﬁeld of natural language processing. The core of the work is an empirical evaluation of a comprehensive list of automatic collocation extraction methods using precision-recall measures and a proposal of a new approach integrating multiple basic methods and statistical classiﬁcation.

• ### Báo cáo khoa học: "Synonymous Collocation Extraction Using Translation Information"

Automatically acquiring synonymous collocation pairs such as and from corpora is a challenging task. For this task, we can, in general, have a large monolingual corpus and/or a very limited bilingual corpus. Methods that use monolingual corpora alone or use bilingual corpora alone are apparently inadequate because of low precision or low coverage. In this paper, we propose a method that uses both these resources to get an optimal compromise of precision and coverage.

• ### Báo cáo khoa học: "Text Segmentation Using Reiteration and Collocation"

A method is presented for segmenting text into subtopic areas. The proportion of related pairwise words is calculated between adjacent windows of text to determine their lexical similarity. The lexical cohesion relations of reiteration and collocation are used to identify related words. These relations are automatically located using a combination of three linguistic features: word repetition, collocation and relation weights. This method is shown to successfully detect known subject changes in text and corresponds well to the segmentations placed by test subjects. ...

• ### Báo cáo khoa học: "Cohesion and Collocation: Using Context Vectors in Text Segmentation"

Collocational word similarity is considered a source of text cohesion that is hard to measure and quantify. The work presented here explores the use of information from a training corpus in measuring word similarity and evaluates the method in the text segmentation task. An implementation, the V e c T i l e system, produces similarity curves over texts using pre-compiled vector representations of the contextual behavior of words. The performance of this system is shown to improve over that of the purely string-based TextTiling algorithm (Hearst, 1997). 1 Background ...

• ### Báo cáo khoa học: "Retrieving Collocations by Co-occurrences and Word Order Constraints"

In this paper, we describe a method for automatically retrieving collocations from large text corpora. This method retrieve collocations in the following stages: 1) extracting strings of characters as units of collocations 2) extracting recurrent combinations of strings in accordance with their word order in a corpus as collocations. Through the method, various range of collocations, especially domain specific collocations, are retrieved.

• ### Báo cáo khoa học: "Improving Statistical Machine Translation with Monolingual Collocation"

This paper proposes to use monolingual collocations to improve Statistical Machine Translation (SMT). We make use of the collocation probabilities, which are estimated from monolingual corpora, in two aspects, namely improving word alignment for various kinds of SMT systems and improving phrase table for phrase-based SMT. The experimental results show that our method improves the performance of both word alignment and translation quality significantly.

• ### Báo cáo khoa học: "Accurate Collocation Extraction Using a Multilingual Parser"

This paper focuses on the use of advanced techniques of text analysis as support for collocation extraction. A hybrid system is presented that combines statistical methods and multilingual parsing for detecting accurate collocational information from English, French, Spanish and Italian corpora. The advantage of relying on full parsing over using a traditional window method (which ignores the syntactic information) is ﬁrst theoretically motivated, then empirically validated by a comparative evaluation experiment. ...

• ### Báo cáo khoa học: "Combining Association Measures for Collocation Extraction"

We introduce the possibility of combining lexical association measures and present empirical results of several methods employed in automatic collocation extraction. First, we present a comprehensive summary overview of association measures and their performance on manually annotated data evaluated by precision-recall graphs and mean average precision. Second, we describe several classiﬁcation methods for combining association measures, followed by their evaluation and comparison with individual measures. ...

• ### Báo cáo khoa học: "A Nonparametric Method for Extraction of Candidate Phrasal Terms"

This paper introduces a new method for identifying candidate phrasal terms (also known as multiword units) which applies a nonparametric, rank-based heuristic measure. Evaluation of this measure, the mutual rank ratio metric, shows that it produces better results than standard statistical measures when applied to this task. 1 Introduction The ordinary vocabulary of a language like English contains thousands of phrasal terms -multiword lexical units including compound nouns, technical terms, idioms, and fixed collocations. ...

• ### Báo cáo khoa học: "Collocation Translation Acquisition Using Monolingual Corpora"

Collocation translation is important for machine translation and many other NLP tasks. Unlike previous methods using bilingual parallel corpora, this paper presents a new method for acquiring collocation translations by making use of monolingual corpora and linguistic knowledge. First, dependency triples are extracted from Chinese and English corpora with dependency parsers.

• ### Báo cáo khoa học: "Automatic clustering of collocation for detecting practical sense boundary"

This paper talks about the deciding practical sense boundary of homonymous words. The important problem in dictionaries or thesauri is the confusion of the sense boundary by each resource. This also becomes a bottleneck in the practical language processing systems. This paper proposes the method about discovering sense boundary using the collocation from the large corpora and the clustering methods. In the experiments, the proposed methods show the similar results with the sense boundary from a corpus-based dictionary and sense-tagged corpus. ...

• ### Báo cáo khoa học: "FROM N-GRAMS TO COLLOCATIONS AN EVALUATION OF XTRACT"

In previous papers we presented methods for retrieving collocations from large samples of texts. We described a tool, X t r a c t , that implements these methods and able to retrieve a wide range of collocations in a two stage process. These methods a.s well as other related methods however have some limitations. Mainly, the produced collocations do not include any kind of functional information and many of them are invalid. In this paper we introduce methods that address these issues. These methods are implemented in an added third stage to X t r a c t...

• ### Báo cáo khoa học: "UNSUPERVISED WORD SENSE DISAMBIGUATION RIVALING SUPERVISED METHODS"

This paper presents an unsupervised learning algorithm for sense disambiguation that, when trained on unannotated English text, rivals the performance of supervised techniques that require time-consuming hand annotations. The algorithm is based on two powerful constraints - that words tend to have one sense per discourse and one sense per collocation - exploited in an iterative bootstrapping procedure. Tested accuracy exceeds 96%.