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Publicações

Publicações por CRIIS

2010

Contextualized Ubiquity: A new opportunity for rendering business information and services

Autores
Cunha, CR; Peres, E; Morais, R; Bessa, M; Reis, MC;

Publicação
J. Theor. Appl. Electron. Commer. Res.

Abstract
Stating that information and services are ubiquitous, means that they are available anywhere, anytime. The development of mobile-devices with wireless network-access capabilities, together with the decrease in network-traffic costs and the proliferation of free wireless hotspots, makes the use of mobile-devices, as Internet access tools, increasingly common and attractive. With novel forms of presenting information and to provide new ways to interact with consumers, new business strategies can be boosted, in Customer Relationship Management (CRM) and m-commerce. This paper describes a different approach to the relationship between customers and business-providers, based on contextualization mechanisms located in commercial products, which in turn acts as a gateway to static tag-embedded information as well as web-based information and services. A wine integrated management system, called SIGPV, is presented as a proof-of-concept, enumerating some of possible major business and CRM benefits. © 2010 Universidad de Talca - Chile.

2010

A middleware to support dynamic reconfiguration of real-time networks

Autores
Marau, R; Almeida, L; Sousa, M; Pedreiras, P;

Publicação
2010 IEEE CONFERENCE ON EMERGING TECHNOLOGIES AND FACTORY AUTOMATION (ETFA)

Abstract
The middleware is an important software component when designing an application, facilitating the development and deployment of the applications. In the case of Distributed Embedded Systems (DES), the middleware should provide basic functionalities to abstract the complexity that results from network distribution, namely data consistency, events synchronization and resource management. Often DES applications exhibit real-time requirements and have to deal with dynamic environments that present evolving requirements. While some middleware architectures have been proposed to address resource provisioning and QoS management, none of those middle-wares supports dynamic resource reconfiguration while providing real-time guarantees. This paper proposes a middleware layer, based on the services provided by a flexible real-time communication protocol, addressing distribution abstraction, dynamic reconfiguration and dynamic QoS management under real-time constraints.

2010

Replication in Distributed Systems using IEC 61499 Standard

Autores
Santos, AA; de Sousa, M;

Publicação
2010 IEEE CONFERENCE ON EMERGING TECHNOLOGIES AND FACTORY AUTOMATION (ETFA)

Abstract
The international Electrotechnical Commission (IEC) 61499 architecture incorporated several function block with which distributed control application may be developed, and how these are interpreted and executed. However, due the distributed nature of the control applications, many issues also need to be taken into account. Most of these are due to the new error model and failure modes of the distributed hardware on which the distributed application is executed and also due the incomplete standards definition of the execution models. IEC 61499 frameworks does not clarify how to handle with replication of software and hardware components. In this paper we propose a replication model for IEC 61499 applications and which mechanisms and protocols may be used for their support.

2010

Analyzing the Compatibility Between ISA 88 and IEC 61499

Autores
de Sousa, M;

Publicação
2010 IEEE CONFERENCE ON EMERGING TECHNOLOGIES AND FACTORY AUTOMATION (ETFA)

Abstract
In the last years many standards have been created for the industrial control domain. Some have found wide adoption in the industiy, while others seem to never leave the stage of a promising technology. An example of the first type is ISA 88, that defines an architectural design for control applications for the batch process industiy. The author is of the opinion that IEC 61499 is an example of the latter. In this paper the author analyzes how the design architecture defined in ISA 88 may be implemented using the programming framework defined in IEC 61499. Even though ISA 88 and IEC 61499 both follow an event based and object-oriented approach, the author uncovers a fundamental constraint of the IEC 61499 related to the dynamic invocation of services from distinct object instances. Without tiying to extend the IEC 61499 standard, two approaches are presented to work around this constraint.

2010

Proposed corrections to the IEC 61131-3 standard

Autores
de Sousa, M;

Publicação
COMPUTER STANDARDS & INTERFACES

Abstract
The IEC (International Electrotechnical Commission) 61131-3 standard defines several programming languages which may be used to develop industrial control applications. These applications typically execute on industrial PLCs (Programmable Logic Controller). PLC vendors have embraced the first version of this standard [3], with each vendor adopting it at its own pace. As the standard is implemented, several deficiencies have been uncovered. In this paper deficiencies identified by the authors during the implementation of a compiler, compliant with the second version of the standard 141, are explained and analysed. Other deficiencies identified by other authors have also been aggregated and explained. For each deficiency, one or more suggestions (including changes to the formal syntax definition) are made as to how the standard could be changed in order to rectify the deficiency.

2010

PS-InSAR processing methodologies in the detection of field surface deformation Study of the Granada basin (Central Betic Cordilleras, southern Spain)

Autores
Sousa, JJ; Ruiz, AM; Hanssen, RF; Bastos, L; Gil, AJ; Galindo Zaldivar, J; de Galdeano, CS;

Publicação
JOURNAL OF GEODYNAMICS

Abstract
Differential SAR interferometry (DInSAR) is a very effective technique for measuring crustal deformation. However, almost all interferograms include large areas where the signals decorrelate and no measurements are possible. Persistent scatterer interferometry (PS-InSAR) overcomes the decorrelation problem by identifying resolution elements whose echo is dominated by a single scatterer in a series of interferograms. Two time series of 29 ERS-1/2 and 22 ENVISAT ASAR acquisitions of the Granada basin, located in the central sector of the Betic Cordillera (southern Spain), covering the period from 1992 to 2005, were analyzed. Rough topography of the study area associated to its moderate activity geodynamic setting, including faults and folds in an uplifting relief by the oblique Eurasian-African plate convergence, poses a challenge for the application of interferometric techniques. The expected tectonic deformation rates are in the order of similar to 1 mm/yr, which are at the feasibility limit of current InSAR techniques. In order to evaluate whether, under these conditions, InSAR techniques can still be used to monitor deformations we have applied and compared two PS-InSAR approaches: DePSI, the PS-InSAR package developed at Delft University of Technology (TU Delft) and StaMPS (Stanford Method for Persistent Scatterers) developed at Stanford University. Ground motion processes have been identified for the first time in the study area, the most significant process being a subsidence bowl located at the village of Otura. The idea behind this comparative study is to analyze which of the two PS-InSAR approaches considered might be more appropriate for the study of specific areas/environments and to attempt to evaluate the potentialities and benefits that could be derived for the integration of those methodologies.

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