1,721,006 research outputs found
Supporting Structural Evolution of Data in Web-Based Systems via Schema Versioning in the tauXSchema Framework
No full texttauXSchema is a framework for creating and validating temporal XML documents, while using a temporal schema that consists of three components: a conventional XML Schema document annotated with a set of temporal logical and physical annotations. Each one of these components can evolve over time to reflect changes in the real-world. Besides, schema versioning has been long advocated to be the most efficient way to keep track of both data and schema evolution. Hence, in this chapter the authors complete tauXSchema, which is predisposed from the origin to support schema versioning, by defining the operations that are necessary to exploit such a feature and make schema versioning functionalities available to end users. Precisely, the authors’ approach provides a complete and sound set of change primitives and a set of high-level change operations, for the maintenance of each component of a tauXSchema schema, and defines their operational semantics. Furthermore, they propose a new technique for schema versioning in tauXSchema, allowing a complete, integrated and safe management of schema changes
Customizing BPMN Diagrams Using Timelines
Full text linkBPMN (Business Process Model and Notation) is widely used standard modeling technique for representing Business Processes by using diagrams, but lacks in some aspects. Representing execution-dependent and time-dependent decisions in BPMN Diagrams may be a daunting challenge [Carlo Combi et al., 2017]. In many cases such constraints are omitted in order to preserve the simplicity and the readability of the process model. However, for purposes such as compliance checking, process mining, and verification, formalizing such constraints could be very useful. In this paper, we propose a novel approach for annotating BPMN Diagrams with Temporal Synchronization Rules borrowed from the timeline-based planning field. We discuss the expressivity of the proposed approach and show that it is able to capture a lot of complex temporally-related constraints without affecting the structure of BPMN diagrams. Finally, we provide a mapping from annotated BPMN diagrams to timeline-based planning problems that allows one to take advantage of the last twenty years of theoretical and practical developments in the field
Schema Change Operations for Full Support of Schema Versioning in the τXSchema Framework
No full textτXSchema is a framework (a language and a suite of tools) for the creation and validation of time-varying XML documents. A τXSchema schema is composed of a conventional XML Schema annotated with physical and logical annotations. All components of a τXSchema schema can evolve over time to reflect changes in the real-world. Since many applications need to keep track of both data and schema evolution, schema versioning has been long advocated to be the best solution to do this. In this paper, we complete the τXSchema framework, which is predisposed from the origin to support schema versioning, with the definition of the operations which are necessary to exploit such feature and make schema versioning functionalities available to final users. Moreover, we propose a new technique for schema versioning in τXSchema, allowing a complete and safe management of schema changes. It supports both versioning of conventional schema and versioning of annotations, in an integrated manner. For each component of a τXSchema schema, our approach provides a complete and sound set of change primitives and a set of high-level change operations, for the maintenance of such a component and defines their operational semantics
Schema Evolution
No full textThe main goal of this chapter is (i) to present the different research proposals that deal with schema evolution, and (ii) to discuss the support of schema evolution in mainstream DBMSs. The rest of this chapter is organized as follows. The next section gives some background on our subject. In “Current Research in Schema Evolution”, we present the different research proposals on schema evolution. “DBMS Support for Schema Evolution” surveys the support of schema evolution in the state of the art of database technology. Finally, future work directions and conclusion are provided
Schema Versioning
No full textThe main goal of this chapter is (i) to present the different research proposals dealing with schema versioning, and (ii) to discuss the support provided by available DBMSs to manage schema versioning. In particular, the next section gives some basic definitions related to the considered subject. In “Current Research in Schema Versioning”, we present the different research proposals on schema versioning. “DBMS Support for Schema Versioning” surveys the support of schema versioning in existing DBMSs. Finally, future work directions and conclusion are provided
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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