Projector - a partially typed language for querying XML

We describe Projector, a language that can be used to perform a mixture of typed and untyped computation against data represented in XML. For some problems, notably when the data is unstructured or semistructured, the most desirable programming model is against the tree structure underlying the document. When this tree structure has been used to model regular data structures, then these regular structures themselves are a more desirable programming model. The language Projector, described here in outline, gives both models within a single partially typed algebra and is well suited for hybrid applications, for example when fragments of a known structure are embedded in a document whose overall structure is unknown. Projector is an extension of ECMA-262 (aka JavaScript), and therefore inherits an untyped DOM interface. To this has been added some static typing and a dynamic projection primitive, which can be used to assert the presence of a regular structure modelled within the XML. If this structure does exist, the data is extracted and presented as a typed value within the programming language

Online Integration of Semistructured Data

Data integration systems play an important role in the development of distributed multi-database systems. Data integration collects data from heterogeneous and distributed sources, and provides a global view of data to the users. Systems need to process user\u27s applications in the shortest possible time. The virtualization approach to data integration systems ensures that the answers to user requests are the most up-to-date ones. In contrast, the materialization approach reduces data transmission time at the expense of data consistency between the central and remote sites. The virtualization approach to data integration systems can be applied in either batch or online mode. Batch processing requires all data to be available at a central site before processing is started. Delays in transmission of data over a network contribute to a longer processing time. On the other hand, in an online processing mode data integration is performed piece-by-piece as soon as a unit of data is available at the central site. An online processing mode presents the partial results to the users earlier. Due to the heterogeneity of data models at the remote sites, a semistructured global view of data is required. The performance of data integration systems depends on an appropriate data model and the appropriate data integration algorithms used. This thesis presents a new algorithm for immediate processing of data collected from remote and autonomous database systems. The algorithm utilizes the idle processing states while the central site waits for completion of data transmission to produce instant partial results. A decomposition strategy included in the algorithm balances of the computations between the central and remote sites to force maximum resource utilization at both sites. The thesis chooses the XML data model for the representation of semistructured data, and presents a new formalization of the XML data model together with a set of algebraic operations. The XML data model is used to provide a virtual global view of semistructured data. The algebraic operators are consistent with operations of relational algebra, such that any existing syntax based query optimization technique developed for the relational model of data can be directly applied. The thesis shows how to optimize online processing by generating one online integration plan for several data increments. Further, the thesis shows how each independent increment expression can be processed in a parallel mode on a multi core processor system. The dynamic scheduling system proposed in the thesis is able to defer or terminate a plan such that materialization updates and unnecessary computations are minimized. The thesis shows that processing data chunks of fragmented XML documents allows for data integration in a shorter period of time. Finally, the thesis provides a clear formalization of the semistructured data model, a set of algorithms with high-level descriptions, and running examples. These formal backgrounds show that the proposed algorithms are implementable

Wrapping of Web Sources with restricted Query Interfaces by Query Tunneling

AbstractInformation sources in the World Wide Web usually offer two different schemes to their users, an Interface Schema which the user can query and a Result Schema which the user can browse. Often the Interface Schema is more restricted than the Result Schema, moreover many sources offer keyword-search interfaces only. Thus query capabilities of such sources are very small and a useful integration into a mediator-based information system using query capabilities is almost impossible. We propose the Query Tunnelling architecture for the wrapping of these restricted web sources. Wrapping of sources by Query Tunneling hides restrictive query interfaces and makes such sources fully queryable based on their result schema. The process of Query Tunneling is divided into two main steps, Query Relaxation to make a higher order query suitable to a restricted interface and Result Restriction in order to filter the results using the original query

TEI and LMF crosswalks

The present paper explores various arguments in favour of making the Text Encoding Initia-tive (TEI) guidelines an appropriate serialisation for ISO standard 24613:2008 (LMF, Lexi-cal Mark-up Framework) . It also identifies the issues that would have to be resolved in order to reach an appropriate implementation of these ideas, in particular in terms of infor-mational coverage. We show how the customisation facilities offered by the TEI guidelines can provide an adequate background, not only to cover missing components within the current Dictionary chapter of the TEI guidelines, but also to allow specific lexical projects to deal with local constraints. We expect this proposal to be a basis for a future ISO project in the context of the on going revision of LMF

Recovering Grammar Relationships for the Java Language Specification

Grammar convergence is a method that helps discovering relationships between different grammars of the same language or different language versions. The key element of the method is the operational, transformation-based representation of those relationships. Given input grammars for convergence, they are transformed until they are structurally equal. The transformations are composed from primitive operators; properties of these operators and the composed chains provide quantitative and qualitative insight into the relationships between the grammars at hand. We describe a refined method for grammar convergence, and we use it in a major study, where we recover the relationships between all the grammars that occur in the different versions of the Java Language Specification (JLS). The relationships are represented as grammar transformation chains that capture all accidental or intended differences between the JLS grammars. This method is mechanized and driven by nominal and structural differences between pairs of grammars that are subject to asymmetric, binary convergence steps. We present the underlying operator suite for grammar transformation in detail, and we illustrate the suite with many examples of transformations on the JLS grammars. We also describe the extraction effort, which was needed to make the JLS grammars amenable to automated processing. We include substantial metadata about the convergence process for the JLS so that the effort becomes reproducible and transparent

A framework to specify, extract and manage topic maps driven by ontology

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 the referred interoperability.(undefined

Integrating e-commerce standards and initiatives in a multi-layered ontology

The proliferation of different standards and joint initiatives for the classification of products and services (UNSPSC, e-cl@ss, RosettaNet, NAICS, SCTG, etc.) reveals that B2B markets have not reached a consensus on the coding systems, on the level of detail of their descriptions, on their granularity, etc. This paper shows how these standards and initiatives, which are built to cover different needs and functionalities, can be integrated in an ontology using a common multi-layered knowledge architecture. This multi-layered ontology will provide a shared understanding of the domain for applications of e-commerce, allowing the information sharing between heterogeneous systems. We will present a method for designing ontologies from these information sources by automatically transforming, integrating and enriching the existing vocabularies with the WebODE platform. As an illustration, we show an example on the computer domain, presenting the relationships between UNSPSC, e-cl@ss, RosettaNet and an electronic catalogue from an e-commerce platform

Metamorphosis: an environment to achieve semantic interoperability with topic maps

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 the referred interoperability