Paulo Roberto Freire Cunha

A framework for building non-functional software architectures

requirements ( NFRs ) are rarely taken in ac- count in most software development processes. There exist reasons that can help us to understand why these require- ments are not explicitly dealt with: their complexity,their usually informal statement,their high abstraction level,as well as the rare support of languages,methodologies and tools for them. In this paper,we introduce a framework for explicitly dealing with NFRs in the software development process. This framework addresses the description,integra- tion with functional requirements,refinement and mapping of NFRs into actual implementation elements.

An architectural application framework for evolving distributed systems

Abstract In this paper, we present an object-oriented application framework to support the development of evolving distributed systems. The framework combines concepts of the object-oriented paradigm with those of architectural design. The result is a framework which supports extensible and reusable configurations of distributed components. The framework addresses the problem of evolution by allowing the addition, replacement and extension of components of a configuration. Evolution is also possible at run time, where a configuration can change dynamically depending on a particular event. The paper outlines the fundamental aspects of our framework and presents a case study, which illustrates its application.

Energy consumption and execution time estimation of embedded system applications

Embedded systems often have conflicting constraints such as energy and time which considerably harden the design of those systems. In this context, this work proposes a mechanism for supporting design decisions on energy consumption and performance of embedded system applications. In order to depict the practical usability of the proposed methodology, a real case study as well as customized examples are presented. The estimates obtained through the conceived model are 93% close to the respective measures obtained from the real hardware platform.

Incorporating Non-functional Requirements into Software Architectures

The concept of softw are architecture has created a new scenario for incorporating non-functional and transactional requirements into the software design. Transactional and non-functional requirements can be included in an architecture-based software development through formal approaches in which first-order and temporal logic are utilised to deal with them. In this paper, we present an approach in which transactional and non-functional requirements are formally incorporated into a special class of software architectures, known as dynamic software architectures. In order to demonstrate how this proposal can be utilised in a real application, an appointment system is presented.

Implementing home care application in Brazilian Digital TV

GINGA, today an ITU-T Recommendation H.761, was developed to be the middleware of the Brazilian Digital TV model. The DIGA GINGA (Digital Automation Monitoring and Control using GINGA technology) is part of the GINGA CDN project (Code Development Network), a Brazilian research network that aims to add value to GINGA, producing components and applications. The main idea of DIGA GINGA is to share a computational structure of the digital TV set-top-box adding services to users, such as tracking the physical environment (home security), personal monitoring (vital signs) and other applications for home automation. The DIGA GINGA environment will test two of the components specified in the GINGA CDN project, data persistence and channel of return (interactivity channel), which are being implemented at the Group of Computer Networks - GREAT. This study will also present the implementation of a prototype, which provides monitoring and support for who are in a state of recovery or are carriers of diseases that require intensive medical supervision.

An ontological approach for personalized services

The adoption of service-oriented approach and the increasing of business-to-consumer applications have produced impacts over software development. Traditional tasks, such as discovery of appropriate Web services, are becoming more and more an individual experience. This paper presents an ontological approach for personalized services that is based on the perception concept. The proposed model considers user preferences, priorities and constraints, the natural starting point for service configuration.

A knowledge and collaboration-based CBR process to improve network performance-related support activities

Abstract In a context characterized by a growing demand for networked services, users of advanced applications sometimes face network performance troubles that may actually prevent them from completing their tasks. Therefore, providing assistance for user communities that have difficulties using the network has been identified as one of the major issues of performance-related support activities. Despite the advances network management has made over the last years, there is a lack of guidance services to provide users with information that goes beyond merely presenting network properties. In this light, the research community has been highlighting the importance of User-Perceived Quality (UPQ) scores during the evaluation of network services for network applications, such as Quality of Experience (QoE) and Mean Opinion Score (MOS). However, despite their potential to assist end-users to deal with network performance troubles, only few types of network applications have well established UPQ scores. Besides that, they are defined through experiments essentially conducted in laboratory, rather than actual usage. This paper thus presents a knowledge and Collaboration-based Network Users’ Support (CNUS) Case-Based Reasoning (CBR) Process that predicts UPQ scores to assist users by focusing on the collaboration among them through the sharing of their experiences in using network applications. It builds (i) a knowledge base that includes not only information about network performance problems, but also applications’ characteristics, (ii) a case base that contains users’ opinions, and (iii) a user database that stores users’ profiles. By processing them, CNUS benefits users through the indication of the degree of satisfaction they may achieve based on the general opinion from members of their communities in similar contexts. In order to evaluate the suitability of CNUS, a CBR system was built and validated through an experimental study conducted in laboratory with a multi-agent system that simulated scenarios where users request for assistance. The simulation was supported by an ontology of network services and applications and reputation scheme implemented through the PageRank algorithm. The results of the study pointed to the effectiveness of CNUS, and its resilience to users’ collusive and incoherent behaviors. Besides that, they showed the influence of the knowledge about network characteristics, users’ profiles and application features on computer-based support activities.

A Software Architecture-Based Approach for Formalising Middleware Behaviour

The number of open specifications of middleware systems and middleware services is increasing. Despite their complexity, they are traditionally described through APIs (the operation signatures) and informal prose (the behaviour). This fact often leads to ambiguities and makes difficult a better understanding of what is really described. In this paper, we adopt software architecture principles for structuring middleware together the LOTOS language for formalising their behaviour. The adoption of software architecture principles makes explicit structural aspects of the middleware. Meanwhile, the formalisation enables us to check behavioural properties of the middleware. In order to illustrate our approach, we present a LOTOS specification of the well-known object-oriented middleware CORBA and its transaction service.

Model-driven software synthesis for hard real-time applications with energy constraints

Model-driven methods have been quite effective for reducing the intricacies of embedded software development, since they provide effective means for property verification as well as automatic code generation. Nevertheless, regarding energy-constrained hard real-time systems, few model-driven methods are available and, usually, most methods (model-driven or not) consider simplified system specifications, such as absence of intertask relations. This paper presents a model-driven method for software synthesis of hard real-time embedded applications with energy constraints. A formal model based on time Petri nets is adopted in order to provide a basis for pre-runtime schedule generation and property analysis/verification.

SM- Sens: Security middleware for Wireless Sensor Networks

Wireless Sensor Networks (WSNs) are exposed to numerous security threats that can affect the execution of applications. Securing WSNs is challenging due to their unique nature as an application and a network, and due to their limited capabilities. Therefore we introduce SM-Sens, a secure middleware that helps bridge the gap between high-level application requirements and WSN managing complexity. Our middleware uses defense mechanisms like asymmetric cryptography and authentication. The middleware defenses are efficient against a number of attacks either preventing from them or minimizing the damage they may cause to the network. We evaluate our middleware through extensive analysis, implementation, simulations and measurements. We argue that SM-Sens is viable and attractive to applications with security requirements.