Wyniki wyszukiwania - BazTech

1

On sentence membership problem in context sensitive languages

Ryszawa P. A.

Computer Science and Mathematical Modelling

|

2017

|

No. 5

29--44

EN

A new type of graph is introduced, the grammar graph. The possibility of assigning labels to each node in such a graph extends it to the grammar net. The grammar net should be considered as a new graphical tool that helps in an analysis of whether a particular sentence belongs to a given context-sensitive grammar. Another concept, the derivation net, closely related to the grammar graph and of a similar structure, will be used to show an algorithm that is able to decide that some sentences do not belong to a language generated by a context sensitive grammar, while leaving others as a candidate members of it.

PL

W artykule wprowadzony został nowy rodzaj grafu – graf gramatyczny. Możliwość przypisywania etykiet do węzłów daje rozszerzenie do tzw. sieci gramatycznej. Sieć gramatyczną należy traktować jako nowe narzędzie graficzne w analizie przynależności zdań do danego języka kontekstowego. Inna koncepcja, sieć wywodu, ściśle związana z grafem gramatycznym i o podobnej strukturze, została wykorzystana do pokazania algorytmu, który potrafi wstępnie wyselekcjonować niektóre zdania nienależące do danego języka generowanego przez gramatykę kontekstową, pozostawiając inne jako potencjalnie w nim zawarte.

2

On String Languages Generated by Sequential Numerical P Systems

Zhang Z., Wu T., Pan L.

Fundamenta Informaticae

|

2016

|

Vol. 145, nr 4

485--509

EN

Numerical P systems are a class of P systems inspired both from the structure of living cells and from economics. In this work, we further investigate the generative capacity of numerical P systems as language generators. The families of languages generated by non-enzymatic, by enzymatic, and by purely enzymatic (all programs are enzymatic) numerical P systems working in the sequential mode are compared with the language families in the Chomsky hierarchy. Especially, a characterization of recursively enumerable languages is obtained by using purely enzymatic numerical P systems working in the sequential mode.

3

High-level methodologies for grammar engineering. Introduction to the special issue

Duchier D., Parmentier Y.

Journal of Language Modelling

|

2015

|

Vol. 3, No. 1

5--19

EN

Grammar engineering is the task of designing and implementing linguistically motivated electronic descriptions of natural language (socalled grammars). These grammars are expressed within well-defined theoretical frameworks, and offer a fine-grained description of natural language. While grammars were first used to describe syntax, that is to say, the relations between constituents in a sentence, they often go beyond syntax and include semantic information. Grammar engineering provides precise descriptions which can be used for natural language understanding and generation, making these valuable resources for various natural language applications, including textual entailment, dialogue systems, or machine translation. The first attempts at designing large-scale resource grammars were costly because of the complexity of the task (Erbach 1990) and of the number of persons that were needed (see e.g. Doran et al. 1997). Advances in the field have led to the development of environments for semi-automatic grammar engineering, borrowing ideas from compilation (grammar engineering is compared with software development) and machine learning. This special issue reports on new trends in the field, where grammar engineering benefits from elaborate high-level methodologies and techniques, dealing with various issues (both theoretical and practical).

4

Dataspace architecture and manage its components class projection

Shakhovska N., Bolubash Y.

ECONTECHMOD : An International Quarterly Journal on Economics of Technology and Modelling Processes

|

2015

|

Vol. 4, No 1

87--95

EN

Big Data technology is described. Big data is a popular term used to describe the exponential growth and availability of data, both structured and unstructured. There is constructed dataspace architecture. Dataspace has focused solely – and passionately – on providing unparalleled expertise in business intelligence and data warehousing strategy and implementation. Dataspaces are an abstraction in data management that aims to overcome some of the problems encountered in data integration system. In our case it is block vector for heterogeneous data representation. Traditionally, data integration and data exchange systems have aimed to offer many of the purported services of dataspace systems. Dataspaces can be viewed as a next step in the evolution of data integration architectures, but are distinct from current data integration systems in the following way. Data integration systems require semantic integration before any services can be provided. Hence, although there is not a single schema to which all the data conforms and the data resides in a multitude of host systems, the data integration system knows the precise relationships between the terms used in each schema. As a result, significant up-front effort is required in order to set up a data integration system. For realization of data integration from different sources we used SQL Server Integration Services, SSIS. For developing the portal as an architectural pattern there is used pattern Model-View-Controller (MVC). There is specifics debug operation data space as a complex system. The query translator in Backus/Naur Form is give.

5

Filtrations of Formal Languages by Arithmetic Progressions

Mousavi H., Shallit J.

Fundamenta Informaticae

|

2013

|

Vol. 123, nr 2

135--142

EN

A filtration of a formal language L by a sequence s maps L to the set of words formed by taking the letters of words of L indexed only by s. We consider the languages resulting from filtering by all arithmetic progressions. If L is regular, it is easy to see that only finitely many distinct languages result; we give bounds on the number of distinct languages in terms of the state complexity of L. By contrast, there exist CFL’s that give infinitely many distinct languages as a result. We use our technique to show that two related operations, including diag (which extracts the diagonal of words of square length arranged in a square array), preserve regularity but do not preserve context-freeness.