Báo cáo khoa học: "An Empirical Evaluation of Probabilistic Lexicalized Tree Insertion Grammars*" potx

... LTIGs) are tree- rewriting sys- tems, consisting of a set of elementary trees combined by tree operations. We distinguish two types of trees in the set of elementary trees: the initial trees and ... An Empirical Evaluation of Probabilistic Lexicalized Tree Insertion Grammars * Rebecca Hwa Harvard University Cambridge, MA 02138 USA rebecca~eecs.harvard.edu A...

Ngày tải lên: 23/03/2014, 19:20

... resources. Despite all of the attention, there have been very few direct empirical evaluations comparing the merits of the different approaches. This paper empiri- cally examines the tradeoffs between ... weaknesses of each type of approach. The evaluation also brings to light additional proper- ties, including the number of redundant paraphrases generated, that future approache...

Ngày tải lên: 30/03/2014, 21:20

... k train (w) denote the number of occurrences of w in the training corpus, and k test (w) denote the number of occurrences of w in the test corpus. We define the empirical discount of w to be d(w) = k train (w) ... per- vasive phenomenon of growing empirical discounts, except in the case of extremely similar corpora. Growing discounts of this sort were previously sug- gested...

Ngày tải lên: 20/02/2014, 04:20

... summaries consist of a) picking the first n sentences out of a set of selected documents (with different val- ues for n and different sets of documents) and b) taking the full content of a few doc- uments. ... estab- lished as a function of their vocabulary (unigrams) and how this vocabulary is used (n-grams). From this point of view, some of the measures used in the evaluatio...

Ngày tải lên: 20/02/2014, 15:20

... exist to the set of constraint equations, each varl in the set of equations must have a solution. For exam- ple, if 5 instances of sofas are known for varsola, but every assignment of a value to ... de- grees of strength) to some future course of action. The only distinction is whether the commitment is conditional on H's agreement (Offer) or not (Com- mit). With an O...

Ngày tải lên: 20/02/2014, 18:20

... UPENN Chinese Treebank-4(CTB4). We presented an empirical study of Chinese chunk- ing on this corpus. First, we made an evaluation on the corpus to clarify the performance of state- of- the-art models ... in this study. Training Test Num of Files 728 110 Num of Sentences 9,878 5,290 Num of Words 238,906 165,862 Num of Phrases 141,426 101,449 Table 2: Information of the CTB4...

Ngày tải lên: 08/03/2014, 02:21

... value tree in the real estate domain). The arcs of the tree are weighted to represent the importance of the value of an objective in contributing to the value of its parent in the tree (e.g., ... the context of the selection task, by going through the architecture of the evaluation framework. 3.1 The evaluation framework architecture Figure 4 shows the architecture...

Ngày tải lên: 08/03/2014, 05:20

... smaller one because the final accuracy of the former is higher than that of the latter. 6 The variance of a set of selected examples is defined Table 1: Variances of Selected Examples Iteration 234567891011 1,250 ... here four characters to decide a word boundary. A set of the attributes of , and is used to predict the label of the . The set consists of twenty attributes: ten...

Ngày tải lên: 17/03/2014, 08:20

... Abstract We refine and extend prior views of the descrip- tion, purposes, and contexts -of- use of acknowledg- ment acts through empirical examination of the use of acknowledgments in task-based conversa- ... seek to refine and extend prior views of the description, purposes, and contexts -of- use of acknowledgment acts through empirical examina- tion of the use of...

Ngày tải lên: 17/03/2014, 09:20

... categories are stripped off (Figure 2). While most of the state -of- the-art parsers are based on probabilistic CFGs, the parameteriza- tion of the probabilistic model of each parser varies. In ... advantage of dependency parsing is that dependency trees are a reasonable approxima- tion of the semantics of sentences, and are readily usable in NLP applications. Furthermore, the...

Ngày tải lên: 08/03/2014, 01:20