RTR - uma abordagem reflexiva para programação de aplicações tempo real

Tese (Doutorado) - Universidade Federal de Santa Catarina, Centro Tecnologico. Programa de Pós-Graduação em Engenharia ElétricaEsta tese propõe um modelo e uma linguagem de programação que exploram a potencialidade dos paradigmas de orientação a objetos e reflexão computacional, visando contribuir para a solução de vários problemas encontrados atualmente na programação de sistemas tempo real. O modelo proposto, denominado Modelo RTR, permite a definição e o uso de restrições temporais e algoritmos de escalonamento de acordo com as especificidades da aplicação e de forma independente do suporte de execução subjacente, provendo flexibilidade e independência de ambiente operacional. Além disso, a separação entre questões funcionais e de controle, resultante do uso de reflexão computacional, facilita o gerenciamento da complexidade e incrementa a possibilidade de reutilização e a capacidade de manutenção dos sistemas desenvolvidos. A linguagem proposta, denominada Java/RTR, é uma extensão da linguagem Java que implementa explicitamente o modelo RTR, integrando a capacidade temporal do modelo RTR com as facilidades convencionais de Java. A potencialidade e a expressividade da abordagem proposta são demonstradas através de diversos exemplos envolvendo diferentes situações típicas de tempo real, incluindo a representação da sincronização ern aplicaçes multimídia. Além disso, uma extensão do modelo RTR para ambientes distribuídos abertos é descrita e exemplificada. Adicionalmcnte, esta tese também apresenta um estudo abrangente sobre modelos e linguagens tempo real baseados em objetos e/ou reflexão computacional existentes

An Early Real-Time Checker for Retargetable Compile-Time Analysis

ABSTRACT With the demand for energy-efficient embedded computing and the rise of heterogeneous architectures, automatically retargetable techniques are likely to grow in importance. On the one hand, retargetable compilers do not handle realtime constraints properly. On the other hand, conventional worst-case execution time (WCET) approaches are not automatically retargetable: measurement-based methods require time-consuming dynamic characterization of target processors, whereas static program analysis and abstract interpretation are performed in a post-compiling phase, being therefore restricted to the set of supported targets. This paper proposes a retargetable technique to grant early realtime checking (ERTC) capabilities for design space exploration. The technique provides a general (minimum, maximum and exact-delay) timing analysis at compile time. It allows the early detection of inconsistent time-constraint combinations prior to the generation of binary executables, thereby promising higher design productivity. ERTC is a complement to state-of-the-art design flows, which could benefit from early infeasiblity detection and exploration of alternative target processors, before the binary executables are submitted to tight-bound BCET and WCET analyses for the selected target processor

CERTIFICAÇÃO DE QUALIFICAÇÃO PROFISSIONAL DOS PESCADORES NO LITORAL DE SANTA CATARINA, BRASIL

Esse artigo analisou o perfil profissional de 68 pescadores envolvidos na política pública Rede Nacional de Certificação Profissional - Certific, na região do Porto pesqueiro de Itajaí, Santa Catarina, entre 2014/2016, a partir de um estudo de caso sobre a experiência de qualificação profissional pelo Instituto Federal de Santa Catarina - IFSC, campus Itajaí. Pode-se concluir que o perfil dos pescadores do curso corresponde ao Certific, sendo que a maioria (70%) certifica seus saberes, pois trabalhava cerca de 30 anos, sem a documentação exigida, usando subterfúgios para se esquivar da fiscalização, por conta do tempo indisponível para qualificação, tanto que 13% não puderam concluir o curso, impactando assim a vida dos pescadores e, consequentemente, a pesca, que inclui o Certific como política pública ao setor. A metodologia teve uma abordagem quantitativa, exploratória e descritiva, utilizando o método indutivo-dedutivo, tendo como fonte documentos norteadores do Certific, atas das reuniões de acreditação e normas da Marinha, grupos de trabalhos, plano de desenvolvimento do IFSC, bem como projeto pedagógico e formulário de entrevista profissional semiestruturada do curso

A Reflective Model For Real-Time Applications In Open Distributed Systems

: This paper presents a model for distributed applications with real-time constraints in open systems. The RTR model uses the reflective paradigm, providing realtime scheduling, control of time and synchronization constraints, and exception handling. The model adopts the CORBA standard for open systems to provide remote method calls, and handles timing constraints by using timeouts and deadlines. Therefore, the model ensures an efficient treatment of best-effort policies. Also, a prototype implemented using RTR model is described and a multimedia application is used in the prototype to express the model potentialities for real-time programming. Finally, the main characteristics of the RTR model are compared with other approaches adopted to real-time distributed applications. Keywords: Real-time systems, open systems, reflective paradigm, CORBA. 1. INTRODUCTION Advances in research and development of computer hardware and communication networks are allowing the simultaneous processing o..

A Programming Model for Real-Time Applications in Open Distributed Systems

This paper presents a model for distributed applications with real-time constraints in an heterogeneous context. The proposed model is based on CORBA standard architecture, and uses the reflective object paradigm which provides the separation of concerns : functionality and management. Consequently, the model has two levels : a base level which deals with system functionality and a meta level with scheduling, time and synchronization constraints, as well as exception handling. These features are merged in the client/server architecture as defined in the CORBA standard. A timeout value is specified for each client object and a deadline for the server object. These time constraints allow to treat according to a "best-effort" policy the satisfaction of time specifications. After the presentation of the main features of the proposed model, a short example based on the display of a multimedia document is described. 1 Introduction The programming of distributed applications in a heterogeneo..

Regional zoos in Brazil and their specific role for environmental education

This paper evaluates the specific role that regional zoos might play in promoting general biodiversity education. The perceptions of visitors of four zoos in Santa Catarina State, Brazil were obtained through the application of 400 questionnaires at each zoo. Almost half the visitors sought 'leisure in nature' with their families, while in one zoo, the majority of visitors aimed to learn about the fauna through the educational project at this institution. In response to this research, we propose that the primary role of regional zoos should be focused on the promotion of educational programs for environmental conservation of biodiversity

A Model-Driven Automatically-Retargetable Debug Tool for Embedded Systems

Abstract. Contemporary SoC designs ask for system-level debugging tools suitable to heterogeneous platforms. Such tools will have to rely on some low-level model-driven debugging engine that must be retargetable, since embedded code may run on distinct processors within the same platform. This paper describes a technique for automatically retargeting debugging tools for embedded code inspection. The technique relies on two key ideas: automatic extraction of machinedependent information from a formal model of the processor and reuse of a conventional binary utility package as implementation infrastructure. The retargetability of the technique was experimentally validated for targets MIPS, SPARC, PowerPC and i8051.