Suporte a grupos cooperativos em ambiente distribuido aberto

Orientador: Edmundo Roberto Mauro MadeiraDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Matematica, Estatistica e Ciencia da ComputaçãoResumo: O estilo de interação em grupo entre os usuários é característica básica de aplicações de trabalho cooperativo. Neste contexto, é fundamental a existência de suporte apropriado de sistemas distribuídos para a estruturação das aplicações em termos de grupos de objetos, permitindo a interação cooperativa entre eles. Este trabalho propõe um modelo para um serviço de suporte a grupos de objetos, a ser usado como ferramenta na construção de aplicações cooperativas. O modelo provê mecanismos para a manutenção consistente dos conjuntos de membros associados aos grupos, bem como para o suporte à coordenação e transparência da comunicação de grupo. A proposta fundamenta-se no Modelo de Referência para Processamento Distribuído Aberto da ISO (RM-ODP) e sua implementação utiliza os recursos da arquitetura CORBA (Common Object Request Broker Architecture), de forma a permitir o uso dos serviços em ambientes computacionais heterogêneos. O trabalho descreve a implementação de um protótipo, no ambiente da Plataforma Multiware, o qual provê os serviços básicos do modelo de suporte a grupos.Abstract: Computer supported cooperative work applications can be characterized by the style of group interactions among their users. In this context, it is essential the provision of mechanisms that offer suitable support to structure applications in terms of cooperating object groups. This work proposes a model of a group support service to be used as a tool for building cooperative applications. The model provides mechanisms to consistently maintain group membership, as well as to support the coordination and transparency of group communication. The work is based on the ISO Reference Model for Open Distributed Processing (RM-ODP) and its implementation uses resources from the Common Object Request Broker Architecture (CORBA), allowing the services to be used in a heterogeneous computing environment. It is also described the implementation of a prototype, in the Multiware Platform environment, which provides the basic services from the group support model.MestradoMestre em Ciência da Computaçã

Extended enterprise architecture with the FADEE.

Business-to-Business integration (B2Bi) is considered to be not merely an IT-issue, but also a business problem. This paper draws attention to the challenges companies within an Extended Enterprise are confronted with when integrating their systems. We primarily pay attention to coordination problems that may arise. To overcome these problems we propose the use of Enterprise Architecture descriptions. We discuss the powers of using Enterprise Architecture descriptions in integration exercises. It will become clear that doing Enterprise Architecture is no longer an option; it is mandatory. Furthermore, we present the FADEE, the Framework for the Architectural Description of the Extended Enterprise. This framework gives an overview of how companies can apply the Zachman framework to do Enterprise Architecture in the realm of the Extended Enterprise.Architecture; Business-to-Business integration; Companies; Coordination; Enterprise architecture; Extended enterprise; Extended enterprise architecture framework; FADEE; Framework; Integration; Problems; Research; Systems;

Management and architecture click: The FAD(E)E Framework.

Enterprises are living things. They constantly need to be (re-)architected in order to achieve the necessary agility, alignment and integration. This paper gives a high-level overview of how companies can go about doing 'enterprise architecture' in the context of both the classic (isolated) enterprise and the Extended Enterprise. By discussing the goals that are pursued in an enterprise architecture effort we reveal some basic requirements that can be put on the process of architecting the enterprise. The relationship between managing and architecting the enterprise is discussed and clarified in the FAD(E)E, the Framework for the Architectural Development of the (Extended) Enterprise.Management; Architecture; Framework;

The effect of the distributed test architecture on the power of testing

Copyright @ 2008 Oxford University PressThere has been much interest in testing from finite-state machines (FSMs). If the system under test can be modelled by the (minimal) FSM N then testing from an (minimal) FSM M is testing to check that N is isomorphic to M. In the distributed test architecture, there are multiple interfaces/ports and there is a tester at each port. This can introduce controllability/synchronization and observability problems. This paper shows that the restriction to test sequences that do not cause controllability problems and the inability to observe the global behaviour in the distributed test architecture, and thus relying only on the local behaviour at remote testers, introduces fundamental limitations into testing. There exist minimal FSMs that are not equivalent, and so are not isomorphic, and yet cannot be distinguished by testing in this architecture without introducing controllability problems. Similarly, an FSM may have non-equivalent states that cannot be distinguished in the distributed test architecture without causing controllability problems: these are said to be locally s-equivalent and otherwise they are locally s-distinguishable. This paper introduces the notion of two states or FSMs being locally s-equivalent and formalizes the power of testing in the distributed test architecture in terms of local s-equivalence. It introduces a polynomial time algorithm that, given an FSM M, determines which states of M are locally s-equivalent and produces minimal length input sequences that locally s-distinguish states that are not locally s-equivalent. An FSM is locally s-minimal if it has no pair of locally s-equivalent states. This paper gives an algorithm that takes an FSM M and returns a locally s-minimal FSM M′ that is locally s-equivalent to M.This work was supported in part by Leverhulme Trust grant number F/00275/D, Testing State Based Systems, Natural Sciences and Engineering Research Council (NSERC) of Canada grant number RGPIN 976, and Engineering and Physical Sciences Research Council grant number GR/R43150, Formal Methods and Testing (FORTEST)

Tracing the distribution concern: Bridging the Gap

Distribution is often presented as an example of a crosscutting concern that is difficult to modularize. This paper presents an approach for modeling distribution using a combination of AOSD and use cases. One of the aims of the paper is to bridge the gap between the handling of crosscutting concerns during the early and later phases of the lifecycle when developing distributed applications. With our approach the distribution concern is modularized in control objects in Analysis, in design control classes in Design and in distributed components in Implementation and Deployment. Use cases are used to establish a clear traceability among the analysis, design, deployment and implementation stages. In this sense, control objects of the analysis have a direct correspondence with distributed components in the implementation and deployment models

The stock-flow model of spatial data infrastructure development refined by fuzzy logic

The system dynamics technique has been demonstrated to be a proper method by which to model and simulate the development of spatial data infrastructures (SDI). An SDI is a collaborative effort to manage and share spatial data at different political and administrative levels. It is comprised of various dynamically interacting quantitative and qualitative (linguistic) variables. To incorporate linguistic variables and their joint effects in an SDI-development model more effectively, we suggest employing fuzzy logic. Not all fuzzy models are able to model the dynamic behavior of SDIs properly. Therefore, this paper aims to investigate different fuzzy models and their suitability for modeling SDIs. To that end, two inference and two defuzzification methods were used for the fuzzification of the joint effect of two variables in an existing SDI model. The results show that the Average–Average inference and Center of Area defuzzification can better model the dynamics of SDI development

Bridging the gap between modellers and model users, why does this gap exist and what can we do about it?

To access publisher´s full text version of this article. Please click on the hyperlink in Additional Links field.Streptococcus pneumoniae, also called the pneumococcus, is a major bacterial pathogen. Since its introduction in the 1940s, penicillin has been the primary treatment for pneumococcal diseases. Penicillin resistance rapidly increased among pneumococci over the past 30 years, and one particular multidrug-resistant clone, PMEN1, became highly prevalent globally. We studied a collection of 426 pneumococci isolated between 1937 and 2007 to better understand the evolution of penicillin resistance within this species. We discovered that one of the earliest known penicillin-nonsusceptible pneumococci, recovered in 1967 from Australia, was the likely ancestor of PMEN1, since approximately 95% of coding sequences identified within its genome were highly similar to those of PMEN1. The regions of the PMEN1 genome that differed from the ancestor contained genes associated with antibiotic resistance, transmission and virulence. We also revealed that PMEN1 was uniquely promiscuous with its DNA, donating penicillin-resistance genes and sometimes many other genes associated with antibiotic resistance, virulence and cell adherence to many genotypically diverse pneumococci. In particular, we describe two strains in which up to 10% of the PMEN1 genome was acquired in multiple fragments, some as long as 32 kb, distributed around the recipient genomes. This type of directional genetic promiscuity from a single clone to numerous unrelated clones has, to our knowledge, never before been described. These findings suggest that PMEN1 is a paradigm of genetic success both through its epidemiology and promiscuity. These findings also challenge the existing views about horizontal gene transfer among pneumococci