scholarly journals Balancing Expressiveness and Inexpressiveness in View Design

2021 ◽  
Vol 46 (4) ◽  
pp. 1-40
Author(s):  
Michael Benedikt ◽  
Pierre Bourhis ◽  
Louis Jachiet ◽  
Efthymia Tsamoura
Keyword(s):  
Information Systems ◽  
Query Languages ◽  
Data Sources ◽  
Data Publishing ◽  
Common Mechanism ◽  
Distributed Data ◽  
Conjunctive Queries ◽  
Derived Data ◽  
Minimal Information

We study the design of data publishing mechanisms that allow a collection of autonomous distributed data sources to collaborate to support queries. A common mechanism for data publishing is via views : functions that expose derived data to users, usually specified as declarative queries. Our autonomy assumption is that the views must be on individual sources, but with the intention of supporting integrated queries. In deciding what data to expose to users, two considerations must be balanced. The views must be sufficiently expressive to support queries that users want to ask—the utility of the publishing mechanism. But there may also be some expressiveness restrictions. Here, we consider two restrictions, a minimal information requirement, saying that the views should reveal as little as possible while supporting the utility query, and a non-disclosure requirement, formalizing the need to prevent external users from computing information that data owners do not want revealed. We investigate the problem of designing views that satisfy both expressiveness and inexpressiveness requirements, for views in a restricted information systems - query languages (conjunctive queries), and for arbitrary views.

scholarly journals Balancing Expressiveness and Inexpressiveness in View Design

2020 ◽  
Author(s):  
Michael Benedikt ◽  
Pierre Bourhis ◽  
Louis Jachiet ◽  
Efthymia Tsamoura
Keyword(s):  
Data Publishing ◽  
Common Mechanism ◽  
Declarative Language ◽  
Conjunctive Queries ◽  
Information Requirement ◽  
Disclosure Requirement ◽  
Derived Data ◽  
Minimal Information

We study the design of data publishing mechanisms that allow a collection of autonomous distributed datasources to collaborate to support queries. A common mechanism for data publishing is via views: functions that expose derived data to users, usually specified as declarative queries. Our autonomy assumption is that the views must be on individual sources, but with the intention of supporting integrated queries. In deciding what data to expose to users, two considerations must be balanced. The views must be sufficiently expressive to support queries that users want to ask -- the utility of the publishing mechanism. But there may also be some expressiveness restriction. Here we consider two restrictions, a minimal information requirement, saying that the views should reveal as little as possible while supporting the utility query, and a non-disclosure requirement, formalizing the need to prevent external users from computing information that data owners do not want revealed. We investigate the problem of designing views that satisfy both an expressiveness and an inexpressiveness requirement, for views in a restricted declarative language (conjunctive queries), and for arbitrary views.

A Formal Framework for Complex Event Recognition

2021 ◽  
Vol 46 (4) ◽  
pp. 1-49
Author(s):  
Alejandro Grez ◽  
Cristian Riveros ◽  
Martín Ugarte ◽  
Stijn Vansummeren
Keyword(s):  
Query Languages ◽  
Event Recognition ◽  
Distributed Data ◽  
Performance Guarantees ◽  
Selection Strategies ◽  
Trade Offs ◽  
Formal Framework ◽  
Linear Delay ◽  
Complex Events ◽  
Complex Event Recognition

Complex event recognition (CER) has emerged as the unifying field for technologies that require processing and correlating distributed data sources in real time. CER finds applications in diverse domains, which has resulted in a large number of proposals for expressing and processing complex events. Existing CER languages lack a clear semantics, however, which makes them hard to understand and generalize. Moreover, there are no general techniques for evaluating CER query languages with clear performance guarantees. In this article, we embark on the task of giving a rigorous and efficient framework to CER. We propose a formal language for specifying complex events, called complex event logic (CEL), that contains the main features used in the literature and has a denotational and compositional semantics. We also formalize the so-called selection strategies, which had only been presented as by-design extensions to existing frameworks. We give insight into the language design trade-offs regarding the strict sequencing operators of CEL and selection strategies. With a well-defined semantics at hand, we discuss how to efficiently process complex events by evaluating CEL formulas with unary filters. We start by introducing a formal computational model for CER, called complex event automata (CEA), and study how to compile CEL formulas with unary filters into CEA. Furthermore, we provide efficient algorithms for evaluating CEA over event streams using constant time per event followed by output-linear delay enumeration of the results.

scholarly journals Using ontology merging for the integration of information systems and the production capacity planning system

2019 ◽  
pp. 401-408
Author(s):  
N Yarushkina ◽  
A Romanov ◽  
A Filippov ◽  
A Dolganovskaya ◽  
M Grigoricheva
Keyword(s):  
Information System ◽  
Information Systems ◽  
Relational Database ◽  
Data Model ◽  
Capacity Planning ◽  
Production Capacity ◽  
Semantic Integration ◽  
Data Sources ◽  
Planning System ◽  
Ontology Merging

This article describes the method of integrating information systems of an aircraft factory with the production capacity planning system based on the ontology merging. The ontological representation is formed for each relational database (RDB) of integrated information systems. The ontological representation is formed in the process of analyzing the structure of the relational database of the information system (IS). Based on the ontological representations merging the integrating data model is formed. The integrating data model is a mechanism for semantic integration of data sources.

An Ontology-based approach to enable data-driven research in the field of NDT in Civil Engineering

2021 ◽  
Author(s):  
Benjamin Moreno-Torres ◽  
Christoph Völker ◽  
Sabine Kruschwitz
Keyword(s):  
Knowledge Representation ◽  
Civil Engineering ◽  
Common Knowledge ◽  
Measurement Data ◽  
Data Access ◽  
Semantic Knowledge ◽  
Data Sources ◽  
Data Sets ◽  
Extensive Literature ◽  
Distributed Data

<div> <p>Non-destructive testing (NDT) data in civil engineering is regularly used for scientific analysis. However, there is no uniform representation of the data yet. An analysis of distributed data sets across different test objects is therefore too difficult in most cases.</p> <p>To overcome this, we present an approach for an integrated data management of distributed data sets based on Semantic Web technologies. The cornerstone of this approach is an ontology, a semantic knowledge representation of our domain. This NDT-CE ontology is later populated with the data sources. Using the properties and the relationships between concepts that the ontology contains, we make these data sets meaningful also for machines. Furthermore, the ontology can be used as a central interface for database access. Non-domain data sources can be integrated by linking them with the NDT ontology, making them directly available for generic use in terms of digitization. Based on an extensive literature research, we outline the possibilities that result for NDT in civil engineering, such as computer-aided sorting and analysis of measurement data, and the recognition and explanation of correlations.</p> <p>A common knowledge representation and data access allows the scientific exploitation of existing data sources with data-based methods (such as image recognition, measurement uncertainty calculations, factor analysis or material characterization) and simplifies bidirectional knowledge and data transfer between engineers and NDT specialists.</p> </div>

Informational Data Mining

2013 ◽  
pp. 58-65
Author(s):  
Feyza Gürbüz ◽  
Fatma Gökçe Önen
Keyword(s):  
Data Mining ◽  
Information Systems ◽  
Knowledge Discovery ◽  
Major Change ◽  
Research Community ◽  
Data Sources ◽  
Accurate Information ◽  
Rule Mining ◽  
Data Mining Techniques ◽  
Information Strategies

The previous decades have witnessed major change within the Information Systems (IS) environment with a corresponding emphasis on the importance of specifying timely and accurate information strategies. Currently, there is an increasing interest in data mining and information systems optimization. Therefore, it makes data mining for optimization of information systems a new and growing research community. This chapter surveys the application of data mining to optimization of information systems. These systems have different data sources and accordingly different objectives for knowledge discovery. After the preprocessing stage, data mining techniques can be applied on the suitable data for the objective of the information systems. These techniques are prediction, classification, association rule mining, statistics and visualization, clustering and outlier detection.

Urban Master Data Management

2017 ◽  
pp. 441-465
Author(s):  
Adolphe Ayissi Eteme ◽  
Justin Moskolai Ngossaha
Keyword(s):  
Information Technology ◽  
Information Systems ◽  
Data Management ◽  
Data Repository ◽  
Distributed Data ◽  
Data Systems ◽  
Policy Makers ◽  
Master Data ◽  
Master Data Management

The use of information technology in council management has resulted in the generation of a large amount of data through various autonomous urban bodies. The relevant bodies barely or never reuse such locally-generated data. This may be due particularly to managers', policy makers' and users' lack of awareness of existing information. The Platform for the Integration and Interoperability of the Yaounde Urban Information Systems (YUSIIP) project seeks to reduce this deficit by establishing a federated operational platform of heterogeneous and distributed data systems based on a distributed data repository. The position developed in this paper is that Master Data Management (MDM) will contribute to achieving this objective in a context marked by the dispersion and duplication of data and diversity of information systems.

Web Retrieval of XML Documents

2011 ◽  
pp. 170-199
Author(s):  
Barbara Catania ◽  
Elena Ferrari
Keyword(s):  
Expressive Power ◽  
Data Representation ◽  
Query Languages ◽  
Heterogeneous Data ◽  
Data Sources ◽  
Xml Data ◽  
Web Documents ◽  
Web Retrieval ◽  
Heterogeneous Data Sources ◽  
The Web

Web is characterized by a huge amount of very heterogeneous data sources, that differ both in media support and format representation. In this scenario, there is the need of an integrating approach for querying heterogeneous Web documents. To this purpose, XML can play an important role since it is becoming a standard for data representation and exchange over the Web. Due to its flexibility, XML is currently being used as an interface language over the Web, by which (part of) document sources are represented and exported. Under this assumption, the problem of querying heterogeneous sources can be reduced to the problem of querying XML data sources. In this chapter, we first survey the most relevant query languages for XML data proposed both by the scientific community and by standardization committees, e.g., W3C, mainly focusing on their expressive power. Then, we investigate how typical Information Retrieval concepts, such as ranking, similarity-based search, and profile-based search, can be applied to XML query languages. Commercial products based on the considered approaches are then briefly surveyed. Finally, we conclude the chapter by providing an overview of the most promising research trends in the fields.

Visual Query Languages, Representation Techniques, and Data Models

2011 ◽  
pp. 206-233
Author(s):  
Maria Chiara Caschera ◽  
Arianna D’Ulizia ◽  
Leonardo Tininini
Keyword(s):  
Information Systems ◽  
Relational Databases ◽  
Query Languages ◽  
Visual Query ◽  
Representation Technique ◽  
Key Issues ◽  
Visual Query Languages ◽  
Good Trade ◽  
Definition Of ◽  
Representation Techniques

An easy, efficient, and effective way to retrieve stored data is obviously one of the key issues of any information system. In the last few years, considerable effort has been devoted to the definition of more intuitive, visual-based querying paradigms, attempting to offer a good trade-off between expressiveness and intuitiveness. In this chapter, we analyze the main characteristics of visual languages specifically designed for querying information systems, concentrating on conventional relational databases, but also considering information systems with a less rigid structure such as Web resources storing XML documents. We consider two fundamental aspects of visual query languages: the adopted visual representation technique and the underlying data model, possibly specialized to specific application contexts.

A Framework for Information Systems Integration in Mobile Working Environments

2009 ◽  
pp. 729-755
Author(s):  
Javier García-Guzmán ◽  
María-Isabel Sánchez-Segura ◽  
Antonio de Amescua-Seco ◽  
Mariano Navarro
Keyword(s):  
Information Systems ◽  
Mobile Applications ◽  
Organizational Context ◽  
State Of The Art ◽  
Data Sources ◽  
Integration Framework ◽  
Information Systems Integration ◽  
Working Environments ◽  
Future Work ◽  
Mobile Working

This chapter introduces a framework for designing, distributing, and managing mobile applications that uses and updates information coming from different data sources (databases and systems from different organizations) for helping mobile workers to perform their job. A summary of the state of the art in relation to mobile applications integration is presented. Then, the authors describe the appropriate organizational context for applying the integration framework proposed. Next, the framework components and how the framework is use are explained. Finally, the trials performed for testing the mobile applications architecture are discussed, presenting the main conclusions and future work. Furthermore, the authors hope that understanding the concepts related to the integration of mobile applications through the presentation of an integration framework will not only inform researchers of a better design for mobile application architectures, but also assist in the understanding of intricate relationships between the types of functionality required by this kind of systems.

A Framework for Information Systems Integration in Mobile Working Environments

2007 ◽  
pp. 212-224
Author(s):  
J. García-Guzmán ◽  
M. Sánchez-Segura ◽  
A. Amescua-Seco ◽  
M. Navarro
Keyword(s):  
Information Systems ◽  
Mobile Applications ◽  
Organizational Context ◽  
State Of The Art ◽  
Data Sources ◽  
Integration Framework ◽  
Information Systems Integration ◽  
Working Environments ◽  
Future Work ◽  
Mobile Working

This chapter introduces a framework for designing; distributing; and managing mobile applications that uses and updates information coming from different data sources (databases and systems from different organizations) for helping mobile workers to perform their job. A summary of the state of the art in relation to mobile applications integration is presented. Then; the authors describe the appropriate organizational context for applying the integration framework proposed. Next; the framework components and how the framework is use are explained. Finally; the trials performed for testing the mobile applications architecture are discussed; presenting the main conclusions and future work. Furthermore; the authors hope that understanding the concepts related to the integration of mobile applications through the presentation of an integration framework will not only inform researchers of a better design for mobile application architectures; but also assist in the understanding of intricate relationships between the types of functionality required by this kind of systems.

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