Marcelo Gonçalves

Evaluation of the radiopacity of root canal sealers by digitization of radiographic images

The aim of this study was to evaluate the radiopacity of a zinc oxide and eugenol-based (Endofill), a calcium hydroxide-based (Sealapex), two resin-based (Sealer 26 and AH Plus), and a silicone-based root canal sealer (Roeko Seal). Specimens, measuring 10mm in diameter and 1mm in thickness, were radiographed simultaneously with an aluminum step wedge using occlusal films, according to ISO 6876/2001 standards. Radiographs were digitized, and the radiopacity of sealers was compared to the different thicknesses of the aluminum step wedge, using the VIXWIN 2000 software. Results demonstrated that AH Plus was the most radiopaque sealer, while Sealapex was the least radiopaque (p<0.05). Roeko Seal, Endofill and Sealer 26 presented intermediate radiopacity values. Sealapex presented less radiopacity than the other types of root canal sealers.

The state of the art and future perspectives in systems of systems software architectures

Currently, software systems have become increasingly large and complex, often resulted by the integration of several operationally independent systems, resulting in a new class of systems: the Systems of Systems (SoS). In another perspective, software architectures play a major role in determining system quality, since they form the backbone of any successful software-intensive system. Attention given to the software architectures of SoS is also certainly fundamental to the success of such systems. However, it is observed that there is a lack of works that present a wide and, at the same time, a detailed panorama about how SoS architectures have been treated. In this scenario, the main contribution of this paper is to present the state of the art on software architectures of SoS, mainly regarding their development, representation, evaluation, and evolution. This work also contributes with future research topics on SoS architectures that should be still investigated. Besides that, we intend this paper opens new perspectives of research in the software architecture area, intending to contribute to the success of SoS.

Towards a Conceptual Model for Software-Intensive System-of-Systems

Software systems have become increasingly large and complex, often resulting from the integration of several operationally independent systems, thus leading to a new class of systems called Systems-of-Systems (SoS). Moreover, SoS have currently become essentially software-dependent systems, thus arising the Software-intensive Systems-of-Systems (SiSoS). However, in spite of their relevance, there is a lack of a common understanding of what exactly SiSoS are, their characteristics and types, as well as other elements that surround them. In this context, the main contribution of this work is to provide a conceptual model that provides a comprehensive understanding about them. For this purpose, we have extended the ISO/IEC/IEEE 42010 International Standard by considering related studies and previous taxonomies about SoS. In order to illustrate the use of our model, two software-intensive systems were analyzed and discussed. By establishing a common understanding about SiSoS, results achieved until now have showed us that this model can provide an important support to the research on SiSoS and, as a consequence, it can contribute to the development of these systems.

Software architecture and reference architecture of software-intensive systems and systems-of-systems: contributions to the state of the art

Complex software-intensive systems are more and more required as a solution for diverse critical application domains; at the same time, software architecture and also reference architecture have attracted attention as means to more adequately produce and evolve such systems. The main goal of this paper is to summarize our principal contributions in software architecture and reference architecture of software-intensive systems, including Systems-of-Systems. We intend this work can also inspire the opening of other related research lines towards founding the sustainability of such software-intensive systems.

Comparing Agility Analysis Techniques: AgilAC Framework versus Ad Hoc Approach

Agile methods have gained ground in academia and industry since their inception. However, identifying whether a development method is in accordance with the agile philosophy has become a challenge because of the diversity and amount of their activities, artifacts and roles. Thus, we defined the AgilAC framework to support agility analysis of development methods. It supports software engineers to better understand the adherence of their methods to agile philosophy. In order to evaluate the applicability of this framework, an experiment was conducted to comparing the AgilAC and the ad hoc analysis, and it is presented in this paper. We adopted two criteria in the comparison: the time spent during the analysis and the correctness of the analysis result. We observed that although the AgilAC requires more time to be applied than the ad hoc analysis, the quality of the analysis results were better. Therefore, it was possible to verify the advantage of the AgilAC over an ad hoc analysis, when considering the correctness of the agility characterization.