1,720,976 research outputs found
A compiler for distributed RS language
No full textA Linguagem RS é destinada a programação de núcleos reativos centralizados. Tais núcleos são responsáveis por toda a lógica de um sistema reativo, manipulando os sinais de entrada, realizando as reações e gerando os sinais de saída. Sendo sua idéia inicial tratar apenas processos centralizados, não houve a preocupação com a distribuição. Este trabalho tem como principal objetivo apresentar os aspectos introduzidos de uma nova versão para a Linguagem e para o Compilador RS, que possibilitam a execução de programas distribuídos. Além da possibilidade de execução de sistemas reativos distribuídos, foi acrescentado à Linguagem RS extensões já previstas na sua criação, como sinais inibidores, regras de exclusão mútua e concomitância, a possibilidade de disparo de mais de uma regra em um mesmo instante e a limpeza léxica do código fonte RS. As modificações incorporadas nesta nova versão da linguagem, foram efetivadas através de um novo compilador, chamado de Compilador RS 5.0. O protótipo implementado oferece a geração de três formatos de código: o formato padrão da linguagem RS (os autômatos e as regras correspondentes), códigos na linguagem C para a simulação dos autômatos (tanto para programas distribuídos quanto não-distribuídos) e arquivos no formato portável OC, que é um formato de código objeto padrão para as linguagens reativas. Para a distribuição e implementação da Linguagem RS foi necessária a criação de um novo núcleo de comunicação do MDX, que é responsável pela comunicação dos autômatos RSD. Este núcleo é dividido em três partes. A primeira trata da definição de um modelo formal com as mudanças necessárias para que a linguagem RS consiga trabalhar de forma distribuída, a segunda mostra o projeto do novo núcleo MDX e a terceira apresenta a implementação em C e MDX dos autômatos gerados pelo Compilador RS 5.0. Por fim, exemplos de aplicação desta nova linguagem são apresentados, onde podem ser vistos a importância e o acréscimo proporcionado por este trabalho tanto à linguagem RS quanto à programação de sistemas reativos síncronos.The RS language is intended to the programming of centralized reactive kernels. Such kernels are responsible for the logic of a reactive system, manipulating the input signals, carrying through the reactions and generating the output signals. Being its initial idea to treat only centered processes, it did not have the concern with the distribution. The main objective of this work is to describe the process of creation of a new version for the Language and Compiler RS, that make possible the execution of distributed programs. Beyond the possibility of execution distributed reactive systems, it was added to RS language foreseen extensions already in its creation, as inhibiting signals, rules of manual exclusion and concurrence, the possibility of detonation of more than a rule in one exactly instant and the lexical cleanness of the RS code source. The modifications incorporated in this new version of the language, had been accomplished through a new compiler, called Compiler RS 5.0. The implemented archetype offers the generation of three formats of code: the standard format of RS language (the corresponding automatons and rules), codes in the language C for the simulation of the automatons and archives in OC portable format, that is a object format code standard for the reactive languages. For the distribution and implementation of Language RS was necessary the creation of a new kernel of communication of the MDX, that is responsible for the communication of RSD automatons. It is divided in three parts. The first one deals with the definition of a formal model that defines the necessary changes so that RS language obtains to work of distributed form, the second shows the design of new MDX kernel and third presents the implementation in C and MDX of the automatons generated for Compiler RS 5.0. Finally, examples of application of this new language are presented, where the importance and the proportionate upgrade for this work to RS language how to the programming of synchronous reactive systems can in such a way be seen
Metamorphosis – a Topic Maps based Environment to Handle Heterogeneous Information Resources
No full textAbstract. Nowadays, data handled by an institution or company is spread out by more than one database and lots of documents of different types. To extract the information implicit in that data, it is necessary to pick parts from those various archives. To obtain a general overview, those information slices should be gather. Different approaches can be followed to achieve that integration, ranging from the merge of resources till the fusion of the extracted parts. In this paper, we introduce Metamorphosis – a Topic Maps oriented environment to generate conceptual navigators for heterogenous information systems – and we argue that Metamorphosis can be used to achieve, via Topic Maps, the referred interoperability.
and
No full textEveryday a huge number of new information resources are linked to the web. This way the web is growing very fast, making search tasks more and more difficult with worse results. To solve the problem several initiatives were undertaken and a new area of research and development emerged: the one called Semantic Web. When we refer to the semantic web we are thinking about a network of concepts. Each concept has a group of related resources and can be related to other concepts; we can then use this concept network to navigate among web resources or simply among information resources. From the undertaken initiatives one became an ISO standard: Topic Maps ISO 13250. The aim of this paper is to introduce a Topic Map (TM) Builder, that is a processor that extracts topics and relations from instances of a family of XML documents. A TM-Builder is strongly dependent on the resources structure. So, to extract a topic map for different collections of information resources (sets of documents with different structures) we have to implement several TM-Builders, one for each collection. This is not very easy! To overcome this inconvenient we have created an XML abstraction layer for TM-Builders that enables us to specify the topic map we want to build from a concrete family of resources, in order to generate automatically the intended extractor. To describe that process, i.e. the extraction of knowledge from XML documents to produce a TM, we present a language to specify topic maps for a class of XML documents, that we call XSTM (XML Specification for Topic Maps). We also discuss a XSL processor that automatically generates the Extractor from its formal specification written in XSTM, the XSTM-P
Achieving Semantic Interoperability in Heterogeneous Information Systems with Topic Maps
No full textAbstract. Nowadays, data handled by an institution or company is spread out by more than one database and lots of documents of different types. To extract the information implicit in that data, it is necessary to pick parts from those various archives. To obtain a general overview, those information slices should be gather. Different approaches can be followed to achieve that integration, ranging from the merge of resources till the fusion of the extracted parts. In this paper, we introduce Metamorphosis — a Topic Maps oriented environment to generate conceptual navigators for heterogenous information systems — and we argue that Metamorphosis can be used to achieve, via Topic Maps, the referred interoperability. 1
Obtendo Interoperabilidade Semântica em Sistemas Heterogéneos de Informação com Metamorphosis
No full textAbstract. Hoje em dia, os dados manipulados pelas instituições estão dispersos nos mais variados recursos de informação, tais como bases de dados e documentos de diferentes tipos. Com isso, a integração da informação contida nessas fontes é uma tarefa árdua. Diferentes abordagens podem ser seguidas para conseguir a integração, porém o problema principal será conquistar a interoperabilidade semântica entre as fontes de informação, garantindo a manipulação do conjunto sem forçar a conversão das partes em um formato único. Ontologias surgem como uma solução para este problema e Topic Maps, como uma forma de representação de ontologias, afirmam-se como um caminho para alcançar esta solução. Neste contexto, este artigo apresenta o Metamorphosis – um ambiente orientado a Topic Maps composto por módulos capazes de extrair dados de recursos heterogéneos de informação, construir uma ontologia a partir dos mesmos (baseado em uma especificação), validá-la e gerar um sistem
TM-Builder: An Ontology Builder based on XML Topic Maps
No full textEveryday a huge number of new information resources are linked to the web. This way the web is growing very fast, making search tasks more and more difficult with worse results. To solve the problem several initiatives were undertaken and a new area of research and development emerged: the one called Semantic Web.
When we refer to the semantic web we are thinking about a network of concepts. Each concept has a group of related resources and can be related to other concepts; we can then use this concept network to navigate among web resources or simply among information resources. From the undertaken initiatives one became an ISO standard: Topic Maps ISO 13250.
The aim of this paper is to introduce a Topic Map (TM) Builder, that is a processor that extracts topics and relations from instances of a family of XML documents.
A TM-Builder is strongly dependent on the resources structure. So, to extract a topic map for different collections of information resources (sets of documents with different structures) we have to implement several TM-Builders, one for each collection. This is not very easy! To overcome this inconvenient we have created an XML abstraction layer for TM-Builders that enables us to specify the topic map we want to build from a concrete family of resources, in order to generate automatically the intended extractor.
To describe that process, i.e. the extraction of knowledge from XML documents to produce a TM, we present a language to specify topic maps for a class of XML documents, that we call XSTM (XML Specification for Topic Maps). We also discuss a XSL processor that automatically generates the Extractor from its formal specification written in XSTM, the XSTM-P
Constraining XML Topic Maps with XTche
No full textAbstract. This paper presents a process for specifying constraints on topic maps with a constraint language. This language allows to express contextual conditions on classes of Topic Maps. With XTche, a topic map designer defines a set of restrictions that enables to verify if a particular topic map is semantically valid. As the manual checking of large topic maps (frequent in real cases) is impossible, it is mandatory to provide an automatic validator. The constraining process presented in this paper is composed by a language and a processor. The language is based on XML Schema syntax. The processor is developed in XSLT language. The XTche processor takes a XTche specification and it generates a particular XSLT stylesheet. This stylesheet can validate a specific topic map (or a set of them) according to the constraints in the XTche specification. In this paper we will show, in abstract terms and with concrete examples, how to specify Topic Maps schemas and constraints with XTche.
- …
