binarization of synchronous context free grammars

... Trang 1Simplification of Context-Free Grammars Quan Thanh Tho qttho@cse.hcmut.edu.vn Trang 2Simplification of Context-Free Grammars • Some useful substitution rules. • ... Normal FormA context-free grammar G = (V, T, S, P) is in Chomsky normal form iff all productions are of the form: A  BC or A  a where A, B, C  V and a  T. Trang 30Theorem 6.5Any context-free grammar ... Normal FormA context-free grammar G = (V, T, S, P) is in Greibach normal form iff all productions are of the form: A  ax where a  T and x  V*. Trang 35Theorem 6.6Any context-free grammar G

Ngày tải lên: 13/05/2014, 10:21

... (V∗, T∗, S, P∗) Chapter 6: Simplification of Context-Free Grammars Trang 16Proof of theorem 6.1 - Linz ’s bookChapter 6: Simplification of Context-Free Grammars Trang 17Theorem 6.2 - Linz ’s bookTheorem ... unit-productions Chapter 6: Simplification of Context-Free Grammars Trang 3Some Useful Substitution RulesTrang 4A → a | aaA | abbAc | abbcChapter 6: Simplification of Context-Free Grammars Trang 7Removing Useless ... Trang 1Chapter 6: Simplification of Context-FreeGrammars November 13, 2009 Trang 2Simplification of Context-Free GrammarsSome useful substitution rules Removing useless

Ngày tải lên: 23/10/2014, 17:47

... lan-guage classes of each CCG We prove that a wide range of CCGs are strongly context-free, including the CCG of CCG-bank and of the parser of Clark and Cur-ran (2007) In light of these new results, ... class (B) 2.2 Strongly Context-Free CCGs Proposition 1 The set of atoms in any derivation of any CCG consisting of a subset of the schema classes (1-8) and (10-11) is finite. Proof A finite lexicon ... Then, we prove that for a wide range of CCGs there is a context-free grammar (CFG) that has exactly the same derivations Included in this class of strongly context-free CCGs are a grammar including

Ngày tải lên: 20/02/2014, 04:20

... superset of the language we want to parse, but with a fanout of More concretely, a context-free grammar can be read off from discontinuous trees that have been transformed to context-free trees ... tuple of discontinuous strings instead of a single, contiguous sequence of terminals The number of components in such a tuple is called the fan-out of a rule, which is equal to the number of gaps ... one; the fan-out of the grammar is the maximum fan-out of its production A context-free grammar is a LCFRS with a fan-out of For convenience we will will use the rule notation of simple RCG (Boullier,

Ngày tải lên: 08/03/2014, 21:20

... characterization of the expressive power of synchronous tree-adjoining grammars (STAGs) in terms of tree transducers (or equivalently, synchronous tree substitution grammars) is developed Essentially, ... translation has seen a multitude of for-mal translation models Here we focus on syntax-based (or tree-syntax-based) models One of the old-est models is the synchronous context-free gram-mar (Aho and Ullman, ... mechanism, synchronous tree-adjoining grammars (STAGs) as introduced by Shieber and Schabes (1990), that can capture certain (mildly) context-sensitive features of natu-ral language In the tradition of

Ngày tải lên: 17/03/2014, 00:20

... pronunciation of a word does not always consists of the concatenation of the pronunciation of the morphemes, because the pronunciation of mor- phemes can be modified in certain contexts, the ... probabilistic context-free grammar (PCFG), i.e. it combines a "conventional" context- free morphological grammar to filter out ungram- 'police sergeant' 'roof of foliage' ... to the augmentation of the context-free grammar to a PCFG 14. As mentioned above, the accuracy of a PCFG de- pends heavily on the accuracy of the empirical es- timate of the probability function.

Ngày tải lên: 18/03/2014, 02:20

... state-of-the-art grammar can require over a minute of processing for a sin-gle sentence of 25 words, an unacceptable amount of time for real-time applications or when process-ing millions of sentences ... Linear complexity Context-Free parsing pipelines via chart constraints In Proceedings of Human Language Tech-nologies: The 2009 Annual Conference of the North American Chapter of the Association ... ap-proaches of comparing edges of radically differ-ent span lengths and characteristics; and 2) Since the agendas are very small, the overhead of agenda maintenance — a large component of agenda-based

Ngày tải lên: 23/03/2014, 16:20

... formalism which subsumes context- free grammars (CFGs) and tree adjoining grammars (TAGs), as well as the synchronous context-free grammars (SCFGs) and synchronous tree adjoin- ing grammars (STAGs) used ... Binarization of synchronous context-free grammars. Computational Linguistics, 35(4):559–595. Laura Kallmeyer and Wolfgang Maier. 2010. Data- driven parsing with probabilistic linear context-free rewriting ... arrangement h π of M by letting h π (v π(i) ) = i, for each v i ∈ V . As in the proof of Theorem 1, the fan-out of D π i is then related to the cutwidth of the linear arrange- 457 ment h π of M at position

Ngày tải lên: 23/03/2014, 16:20

... assessment of the state of the art across the free-electron laser community in order to evaluate the feasibility Free-of achieving power and other technical parameters specified by the Office Free-of ... open literature The addition of the fourth task was discussed with the Office of Naval Research free-electron-in the free-electron-initial plannfree-electron-ing phase of the study, and it was generally ... The characteristics of different types of free-electron lasers are discussed and compared in detail throughout the report.Following a description of the state of the art of free-electron laser

Ngày tải lên: 28/03/2014, 11:20

... timing, type of book, degree of author involvement, method of free distribution and the nature of free content (protected or not) • What works also depends on the characteristics of the content ... of digitalcontent is increasingly a fact of life Improving ourunderstanding of the value or cost of freely availa-ble content can help steer publishers toward theright answers as the amount of ... use of freely distributed content • Addresses data quality as an underlying issue in the ongoing debate about the impact of free content • Analyzes, documents and shares the results of a set of

Ngày tải lên: 24/04/2014, 15:21

... S, P) be a context-free grammar.  wL(G) iff there exists a derivation tree of G whose yield is w  If tG is a partial derivation tree of G whose root label is S, then the yield of tG is a sentential ... Trang 15Yield of a TreeThe string of symbols obtained by reading the leaves of a tree from left to right (omitting any 's encountered) is called the s encountered) is called the yield of the tree ... linear time parsing algorithm (proportional to the length of a string) Trang 25Simple Grammars (S-Grammars)G = (V, T, S, P) Productions are of the form: A  ax A  V, a  T, and x  V*, and any pair

Ngày tải lên: 13/05/2014, 10:21

... It also has a high curie temperature of 420°C, piezoelectric constant (d33) of 80 pC/N, and coupling factor coefficient (kp) of 0.35 The crystal structure of KNN is dependent on the temperature ... Pengpat*1,2 1 Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai, 50200, Thailand 2 Materials Science Research Center, Faculty of Science, Chiang Mai ... yellow to brownish yellow of the corresponding glass ceramics The low transmittance of the glass-ceramic samples may be attributed to the light scattering due to the occurrence of crystals in the sample

Ngày tải lên: 22/06/2014, 00:20

... results for the pdf of MAI for dif-ferent values ofm are plotted using (8) Different values of m represent MAI in different types of fading environment Re-sults show that as the value ofm decreases, ... variance of MAI in flat Rayleigh fading envi-ronment Experimental Kurtosis of MAI 5.75 5.83 Experimental Variance of MAI 0.0959 0.6204 Analytical Variance of MAI 0.0968 0.6129 for cdf of MAI-plus ... A number of simulation experiments are performed to investigate the behavior of the random variableU i.Figure 3shows the com-parison of experimental and analytical results for the pdf of U ifor

Ngày tải lên: 22/06/2014, 19:20

... consequences for the free energy and entropy of ternary square-free words The interest in the combinatorics of pattern-avoiding [3, 2, 8], in particular of power-free words, goes back to work of Axel Thue ... arise; in other words, all squares of square-free words of length 5 already contain a square of a word of smaller length The radius of convergence x (`) c ≤ x c of the series defining the generating ... for the set of all ternary square free words of any given length, or indeed for the set of all ternary square free words We now want to show that there exist ternary square-free words of infinite

Ngày tải lên: 07/08/2014, 08:20

... maximum degree ∆ of G satisfies ∆ < nk−1−1/ρ Let us now delete the edges of a maximal collection of edge disjoint copies of members of F from Gp The resulting k-graph Gp is clearly F -free Moreover, ... hypothesis Indeed, the condition of simplicity is the same as saying that the 3-graph is F -free, where F is the 3-graph of two edges sharing two vertices The proof of the lower bound in Theorem ... coloring of a k-graph is a coloring of its vertices such that no edge is monochromatic, and the chromatic number is the minimum number of colors in a proper coloring An easy consequence of the

Ngày tải lên: 07/08/2014, 21:20

... the re-agent we used for free radi-cals detection has an acting-time limitation of 75 minutes As the positive results of the effectiveness of Amifostine as scavenger of free radicals in spinal ... ischemia-reperfusion consists of progressive loss of motor neurons accompanied with a steady decline of motor function [3] The complexity of this mechanism is focused to the alteration of the ratio between ... properties of the molecule Having taken into consideration the pharmacokinetic parameters of Amifostine, we managed to achieve the highest concen-tration of its active metabolite during the time of free

Ngày tải lên: 10/08/2014, 10:20

... 1The role of RNA folding free energy in the evolution of the polymerase genes of the influenza A virus Addresses: * Department of Computational Biology, School of Medicine, University of Pittsburgh, ... energies of segments 1 and 2 of NC/99 are at the Predicted folding free energy of the human influenza A strains (polymerase genes) versus year isolated Figure 3 Predicted folding free energy of the ... (PB2, PB1, PA) of the 1918 A/ H1N1 virus were of avian origin, since they are outside of the spectrum of the A/H1N1 folding energies and in the lower spectrum of folding energies of all human viruses

Ngày tải lên: 14/08/2014, 21:20

... length of a string) Chapter 5: Context-Free Grammar Trang 25Simple Grammars (S-Grammars)Trang 26Parsing in Simple Grammars (S-Grammars)w = a1a2 an S ⇒ a1A1A2 Am ⇒a1a2B1B2 BkA1A2 Am ⇒ Chapter 5: Context-Free ... a context-free grammar which L(G) or not Chapter 5: Context-Free Grammar Trang 24Theorem 5.1For every context-free grammar G, there exists an algorithmthat parses any w ∈ L(G) in a number of ... properties of programming languages are not regular Chapter 5: Context-Free Grammar Trang 4CFG and Regular LanguageA regular language is also a context-free language Why the name? Chapter 5: Context-Free

Ngày tải lên: 23/10/2014, 17:47

... UNIVERSITY OF SINGAPORE 2010 Trang 3Name: Selven Virasawmy Degree: Master of Engineering Department: Department of Mechanical Engineering Thesis title: Fabrication of three-dimensional free-standing ... a magnification of 10X (b) Example of misalignment on right hand side of a wafer Alignment marks of the electroplated underneath layer do not coincide with the alignment marks of the upper layer ... 1FABRICATION OF THREE-DIMENSIONAL FREE-STANDING ELECTROMAGNETIC METAMATERIAL STRUCTURES FOR TERAHERTZ FREQUENCIES SELVEN VIRASAWMY NATIONAL UNIVERSITY OF SINGAPORE 2010 Trang 2FABRICATION OF THREE-DIMENSIONAL

Ngày tải lên: 06/10/2015, 20:42

... studies of GIsaround the world, namely, Argan oil of Morocco, Cashmere of Mongolia, Café deColombia and coffee of Costa Rica, Habanos of Cuba, Rooibos tea of South Africa,and Tequila of Mexico ... future Trang 3TABLE OF CONTENTACKNOWLEDGEMENTS ii TABLE OF CONTENT iii LIST OF ABBREVIATIONS v LIST OF TABLES vi LIST OF FIGURES vii LIST OF DIAGRAM viii INTRODUCTION 1 1 Rationale of the study 1 ... projects The protection ofbiodiversity in the coffee grow in regions is also one aim of the FNC Then, coffee of Costa Rica is considered Prices paid for Costa Ricans coffeeare in general higher

Ngày tải lên: 10/08/2016, 16:48