1,721,038 research outputs found
Visually defining and querying consistent multi-granular clinical temporal abstractions
No full textThe main goal of this work is to propose a framework for the visual specification and query of consistent multi-granular clinical temporal abstractions. We focus on the issue of querying patient clinical information by visually defining and composing temporal abstractions, i.e., high level patterns derived from several time-stamped raw data. In particular, we focus on the visual specification of consistent temporal abstractions with different granularities and on the visual composition of different temporal abstractions for querying clinical databases
Querying XML documents by using association rules
No full textIn the last years XML is becoming a standardized means for representing semistructured data, i.e. data having a structure which is not regular and fixed in advance. In this context, documents may have "similar" content but different structure and thus in this work we propose an approximate way to query XML data by means of association rule
Schema Versioning in Databases: A Literature Review
No full textChanges involving the database schema are unavoidable events that sometimes occur in data-centric systems, due to many reasons like evolution of user requirements, corrective maintenance, improvement of the current schema with the addition of new integrity constraints, implementation of new business rules, or compliance to new regulations. In order to manage schema changes, researchers have proposed a technique named "schema versioning", in which all versions of the database schema are kept along with their underlying data, preventing loss of information and obsolescence of legacy applications. This technique has been widely studied in both conventional and emerging databases. Despite lot of interesting research efforts that have dealt with database schema versioning and the importance of this technique for database maintenance, current Database Management Systems (DBMSs) do not provide sufficient support for its implementation.This paper (i) gives an overview of state-of-the-art research approaches to schema versioning in databases, based on the study of more than 270 papers and providing a historical perspective on the development of the topic, (ii) illustrates the support of schema versioning in commercial DBMSs, and (iii) points out some possible future research directions in this area
Temporal Semistructured Data Models and Data Warehouses
No full textThis chapter describes a graph-based approach to represent information stored in a data warehouse, by means of a temporal semistructured data model. We consider issues related to the representation of semistructured data warehouses, and discuss the set of constraints needed to manage in a correct way the warehouse time, that is the time dimension considered storing data in the data warehouse itself. We use a temporal semistructured data model because a data warehouse can contain data coming from different and heterogeneous data sources. This means that data stored in a data warehouse are semistructured in nature; that is, in different documents the same information can be represented in different ways, and the document schemata can be available or not. Moreover, information stored in a data warehouse is often time varying, thus as for semistructured data, also in the data warehouse context, it could be useful to consider time
Complex Association Rules for XML Documents
No full textIn the XML data context, documents may have a "similar" content but a different structure, thus a flexible approach to identify recurrent situations is needed. In this work we show how it is possible to compose structural and value association rules (simple rules) in order to describe complex association rules on XML documents. Moreover, we propose an approach to quantify support and confidence both for simple and complex rules in the XML data context
Specifying temporal data models for semistructured data by a constraint-based approach
No full textIn the past few years some models for semistructured temporal data, which propose different strategies to deal with temporal dimensions, have been denned. In this paper we analyze these models by applying the recently proposed metamodel GSMM (General Semistructured Meta-Model) for semistructured information. GSMM allows us to represent semistructured temporal data models with a unifying formalism; constraints that are specified in these models are also represented and classified on the basis of their expressiveness
Integrated Exploration of Data-Intensive Business Processes
Full text linkModeling and reasoning over business processes require enterprises to manage and integrate large amounts of information. Despite process designers and engineers may benefit from a unified view of process and data models, integrating these two perspectives is challenging, especially when considering conceptual models. In this paper, we provide a uniform formal representation of a process model, the schema of a related database, and the data operations connecting them. Then, we show how we can use such a formal representation to identify interesting information during the integrated conceptual modeling and analysis of processes and related databases, from a process (re-)design and improvement perspective. Finally, we discuss the evaluation of the proposed approach through a controlled experiment and a proof-of-concept implementation that considers both relational and XML database technologies
A modular approach to the specification and management of time duration constraints in BPMN
Full text linkThe modeling and management of business processes deals with temporal aspects both in the inherent representation of activity coordination and in the specification of activity properties and constraints. In this paper, we address the modeling and specification of constraints related to the duration of process activities. In detail, we consider the Business Process Model and Notation (BPMN) standard and propose an approach to define re-usable duration-aware process models that make use of existing BPMN elements for representing different nuances of activity duration at design time. Moreover, we show how advanced event-handling techniques may be exploited for detecting the violation of duration constraints during the process run-time. The set of process models specified in this paper suitably captures duration constraints at different levels of abstraction, by allowing designers to specify the duration of atomic tasks and of selected process regions in a way that is conceptually and semantically BPMN-compliant. Without loss of generality, we refer to real-world clinical working environments to exemplify our approach, as their intrinsic complexity makes them a particularly challenging and rewarding application environment
A semistructured data model for multimedia and temporal clinical information
No full textIn this paper, we propose a semistructured data model for multimedia and temporal clinical information. Our Multimedia Temporal Graphical Model (MTGM) allows one to represent and store clinical information in a semistructured, temporal, and multimedia database. Moreover, the physician can define multimedia presentations based on the stored data. Multimedia presentations are then stored in the same MTGM database together with clinical information and are thus represented according to the same data model. We focus on the issue of providing physicians with the capability of representing in a seamless way both temporal aspects of multimedia data and their temporal presentation requirements. In this context, the valid time is associated both to semistructured information and to multimedia presentations. Furthermore, synchronization constraints can be specified for multimedia presentations. Motivations for our proposal are provided, taken from the domain of cardiac angiography. Taking into account the most recent web-related technologies, we deal also with the translation of MTGM presentations into XML and SMIL documents
Evaluating fuzzy association rules on XML documents
No full textIn this work we propose a flexible approach to evaluate association rules on XML documents. In particular we describe evaluation techniques in order to assign a satisfiability degree to structural association rules, which allow one to evaluate the similarity of the XML document with respect to a given structure, and to value association rules which allow one to capture the similarity between the information contained in the XML document and the required information
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