63 resultados para forced execution of obligations
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It bet on the next generation of computers as architecture with multiple processors and/or multicore processors. In this sense there are challenges related to features interconnection, operating frequency, the area on chip, power dissipation, performance and programmability. The mechanism of interconnection and communication it was considered ideal for this type of architecture are the networks-on-chip, due its scalability, reusability and intrinsic parallelism. The networks-on-chip communication is accomplished by transmitting packets that carry data and instructions that represent requests and responses between the processing elements interconnected by the network. The transmission of packets is accomplished as in a pipeline between the routers in the network, from source to destination of the communication, even allowing simultaneous communications between pairs of different sources and destinations. From this fact, it is proposed to transform the entire infrastructure communication of network-on-chip, using the routing mechanisms, arbitration and storage, in a parallel processing system for high performance. In this proposal, the packages are formed by instructions and data that represent the applications, which are executed on routers as well as they are transmitted, using the pipeline and parallel communication transmissions. In contrast, traditional processors are not used, but only single cores that control the access to memory. An implementation of this idea is called IPNoSys (Integrated Processing NoC System), which has an own programming model and a routing algorithm that guarantees the execution of all instructions in the packets, preventing situations of deadlock, livelock and starvation. This architecture provides mechanisms for input and output, interruption and operating system support. As proof of concept was developed a programming environment and a simulator for this architecture in SystemC, which allows configuration of various parameters and to obtain several results to evaluate it
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Nowadays, the importance of using software processes is already consolidated and is considered fundamental to the success of software development projects. Large and medium software projects demand the definition and continuous improvement of software processes in order to promote the productive development of high-quality software. Customizing and evolving existing software processes to address the variety of scenarios, technologies, culture and scale is a recurrent challenge required by the software industry. It involves the adaptation of software process models for the reality of their projects. Besides, it must also promote the reuse of past experiences in the definition and development of software processes for the new projects. The adequate management and execution of software processes can bring a better quality and productivity to the produced software systems. This work aimed to explore the use and adaptation of consolidated software product lines techniques to promote the management of the variabilities of software process families. In order to achieve this aim: (i) a systematic literature review is conducted to identify and characterize variability management approaches for software processes; (ii) an annotative approach for the variability management of software process lines is proposed and developed; and finally (iii) empirical studies and a controlled experiment assess and compare the proposed annotative approach against a compositional one. One study a comparative qualitative study analyzed the annotative and compositional approaches from different perspectives, such as: modularity, traceability, error detection, granularity, uniformity, adoption, and systematic variability management. Another study a comparative quantitative study has considered internal attributes of the specification of software process lines, such as modularity, size and complexity. Finally, the last study a controlled experiment evaluated the effort to use and the understandability of the investigated approaches when modeling and evolving specifications of software process lines. The studies bring evidences of several benefits of the annotative approach, and the potential of integration with the compositional approach, to assist the variability management of software process lines
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Java Card technology allows the development and execution of small applications embedded in smart cards. A Java Card application is composed of an external card client and of an application in the card that implements the services available to the client by means of an Application Programming Interface (API). Usually, these applications manipulate and store important information, such as cash and confidential data of their owners. Thus, it is necessary to adopt rigor on developing a smart card application to improve its quality and trustworthiness. The use of formal methods on the development of these applications is a way to reach these quality requirements. The B method is one of the many formal methods for system specification. The development in B starts with the functional specification of the system, continues with the application of some optional refinements to the specification and, from the last level of refinement, it is possible to generate code for some programming language. The B formalism has a good tool support and its application to Java Card is adequate since the specification and development of APIs is one of the major applications of B. The BSmart method proposed here aims to promote the rigorous development of Java Card applications up to the generation of its code, based on the refinement of its formal specification described in the B notation. This development is supported by the BSmart tool, that is composed of some programs that automate each stage of the method; and by a library of B modules and Java Card classes that model primitive types, essential Java Card API classes and reusable data structures
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The increase of applications complexity has demanded hardware even more flexible and able to achieve higher performance. Traditional hardware solutions have not been successful in providing these applications constraints. General purpose processors have inherent flexibility, since they perform several tasks, however, they can not reach high performance when compared to application-specific devices. Moreover, since application-specific devices perform only few tasks, they achieve high performance, although they have less flexibility. Reconfigurable architectures emerged as an alternative to traditional approaches and have become an area of rising interest over the last decades. The purpose of this new paradigm is to modify the device s behavior according to the application. Thus, it is possible to balance flexibility and performance and also to attend the applications constraints. This work presents the design and implementation of a coarse grained hybrid reconfigurable architecture to stream-based applications. The architecture, named RoSA, consists of a reconfigurable logic attached to a processor. Its goal is to exploit the instruction level parallelism from intensive data-flow applications to accelerate the application s execution on the reconfigurable logic. The instruction level parallelism extraction is done at compile time, thus, this work also presents an optimization phase to the RoSA architecture to be included in the GCC compiler. To design the architecture, this work also presents a methodology based on hardware reuse of datapaths, named RoSE. RoSE aims to visualize the reconfigurable units through reusability levels, which provides area saving and datapath simplification. The architecture presented was implemented in hardware description language (VHDL). It was validated through simulations and prototyping. To characterize performance analysis some benchmarks were used and they demonstrated a speedup of 11x on the execution of some applications
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This paper proposes a systematic approach to management of variability modelsdriven and aspects using the mechanisms of approaches Aspect-Oriented Software Development (AOSD) and Model-Driven Development (MDD). The main goal of the approach, named CrossMDA-SPL, is to improve the management(gerência), modularization and isolation ou separation of the variability of the LPSs of architecture in a high level of abstraction (model) at the design and implementing phases of development Software Product Lines (SPLs), exploiting the synergy between AOSD and MDD. The CrossMDA-SPL approach defines some artifacts basis for advance the separation clear in between the mandatory (bounden) and optional features in the architecture of SPL. The artifacts are represented by two models named: (i) core model (base domain) - responsible for specify the common features the all members of the SPL, and (ii) variability model - responsible for represent the variables features of SPL. In addition, the CrossMDA-SPL approach is composed of: (i) guidelines for modeling and representation of variability, (ii) CrossMDA-SPL services and process, and (iii) models of the architecture of SPL or product instance of SPL. The guidelines use the advantages of AOSD and MDD to promote a better modularization of the variable features of the architecture of SPL during the creation of core and variability models of the approach. The services and sub-processes are responsible for combination automatically, through of process of transformation between the core and variability models, and the generation of new models that represent the implementation of the architecture of SPL or a instance model of SPL. Mechanisms for effective modularization of variability for architectures of SPL at model level. The concepts are described and measured with the execution of a case study of an SPL for management systems of transport electronic tickets
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With the increasing complexity of software systems, there is also an increased concern about its faults. These faults can cause financial losses and even loss of life. Therefore, we propose in this paper the minimization of faults in software by using formally specified tests. The combination of testing and formal specifications is gaining strength in searches mainly through the MBT (Model-Based Testing). The development of software from formal specifications, when the whole process of refinement is done rigorously, ensures that what is specified in the application will be implemented. Thus, the implementation generated from these specifications would accurately depict what was specified. But not always the specification is refined to the level of implementation and code generation, and in these cases the tests generated from the specification tend to find fault. Additionally, the generation of so-called "invalid tests", ie tests that exercise the application scenarios that were not addressed in the specification, complements more significantly the formal development process. Therefore, this paper proposes a method for generating tests from B formal specifications. This method was structured in pseudo-code. The method is based on the systematization of the techniques of black box testing of boundary value analysis, equivalence partitioning, as well as the technique of orthogonal pairs. The method was applied to a B specification and B test machines that generate test cases independent of implementation language were generated. Aiming to validate the method, test cases were transformed manually in JUnit test cases and the application, created from the B specification and developed in Java, was tested. Faults were found with the execution of the JUnit test cases
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This dissertation presents a model-driven and integrated approach to variability management, customization and execution of software processes. Our approach is founded on the principles and techniques of software product lines and model-driven engineering. Model-driven engineering provides support to the specification of software processes and their transformation to workflow specifications. Software product lines techniques allows the automatic variability management of process elements and fragments. Additionally, in our approach, workflow technologies enable the process execution in workflow engines. In order to evaluate the approach feasibility, we have implemented it using existing model-driven engineering technologies. The software processes are specified using Eclipse Process Framework (EPF). The automatic variability management of software processes has been implemented as an extension of an existing product derivation tool. Finally, ATL and Acceleo transformation languages are adopted to transform EPF process to jPDL workflow language specifications in order to enable the deployment and execution of software processes in the JBoss BPM workflow engine. The approach is evaluated through the modeling and modularization of the project management discipline of the Open Unified Process (OpenUP)
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Automation has become increasingly necessary during the software test process due to the high cost and time associated with such activity. Some tools have been proposed to automate the execution of Acceptance Tests in Web applications. However, many of them have important limitations such as the strong dependence on the structure of the HTML pages and the need of manual valuing of the test cases. In this work, we present a language for specifying acceptance test scenarios for Web applications called IFL4TCG and a tool that allows the generation of test cases from these scenarios. The proposed language supports the criterion of Equivalence Classes Partition and the tool allows the generation of test cases that meet different combination strategies (i.e., Each-Choice, Base-Choice and All Combinations). In order to evaluate the effectiveness of the proposed solution, we used the language and the associated tool for designing and executing Acceptance Tests on a module of Sistema Unificado de Administração Pública (SUAP) of Instituto Federal Rio Grande do Norte (IFRN). Four Systems Analysts and one Computer Technician, which work as developers of the that system, participated in the evaluation. Preliminary results showed that IFL4TCG can actually help to detect defects in Web applications
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With the advance of the Cloud Computing paradigm, a single service offered by a cloud platform may not be enough to meet all the application requirements. To fulfill such requirements, it may be necessary, instead of a single service, a composition of services that aggregates services provided by different cloud platforms. In order to generate aggregated value for the user, this composition of services provided by several Cloud Computing platforms requires a solution in terms of platforms integration, which encompasses the manipulation of a wide number of noninteroperable APIs and protocols from different platform vendors. In this scenario, this work presents Cloud Integrator, a middleware platform for composing services provided by different Cloud Computing platforms. Besides providing an environment that facilitates the development and execution of applications that use such services, Cloud Integrator works as a mediator by providing mechanisms for building applications through composition and selection of semantic Web services that take into account metadata about the services, such as QoS (Quality of Service), prices, etc. Moreover, the proposed middleware platform provides an adaptation mechanism that can be triggered in case of failure or quality degradation of one or more services used by the running application in order to ensure its quality and availability. In this work, through a case study that consists of an application that use services provided by different cloud platforms, Cloud Integrator is evaluated in terms of the efficiency of the performed service composition, selection and adaptation processes, as well as the potential of using this middleware in heterogeneous computational clouds scenarios
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The increasing complexity of integrated circuits has boosted the development of communications architectures like Networks-on-Chip (NoCs), as an architecture; alternative for interconnection of Systems-on-Chip (SoC). Networks-on-Chip complain for component reuse, parallelism and scalability, enhancing reusability in projects of dedicated applications. In the literature, lots of proposals have been made, suggesting different configurations for networks-on-chip architectures. Among all networks-on-chip considered, the architecture of IPNoSys is a non conventional one, since it allows the execution of operations, while the communication process is performed. This study aims to evaluate the execution of data-flow based applications on IPNoSys, focusing on their adaptation against the design constraints. Data-flow based applications are characterized by the flowing of continuous stream of data, on which operations are executed. We expect that these type of applications can be improved when running on IPNoSys, because they have a programming model similar to the execution model of this network. By observing the behavior of these applications when running on IPNoSys, were performed changes in the execution model of the network IPNoSys, allowing the implementation of an instruction level parallelism. For these purposes, analysis of the implementations of dataflow applications were performed and compared
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Alongside the advances of technologies, embedded systems are increasingly present in our everyday. Due to increasing demand for functionalities, many tasks are split among processors, requiring more efficient communication architectures, such as networks on chip (NoC). The NoCs are structures that have routers with channel point-to-point interconnect the cores of system on chip (SoC), providing communication. There are several networks on chip in the literature, each with its specific characteristics. Among these, for this work was chosen the Integrated Processing System NoC (IPNoSyS) as a network on chip with different characteristics compared to general NoCs, because their routing components also accumulate processing function, ie, units have functional able to execute instructions. With this new model, packets are processed and routed by the router architecture. This work aims at improving the performance of applications that have repetition, since these applications spend more time in their execution, which occurs through repeated execution of his instructions. Thus, this work proposes to optimize the runtime of these structures by employing a technique of instruction-level parallelism, in order to optimize the resources offered by the architecture. The applications are tested on a dedicated simulator and the results compared with the original version of the architecture, which in turn, implements only packet level parallelism
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Web services are software units that allow access to one or more resources, supporting the deployment of business processes in the Web. They use well-defined interfaces, using web standard protocols, making possible the communication between entities implemented on different platforms. Due to these features, Web services can be integrated as services compositions to form more robust loose coupling applications. Web services are subject to failures, unwanted situations that may compromise the business process partially or completely. Failures can occur both in the design of compositions as in the execution of compositions. As a result, it is essential to create mechanisms to make the implementation of service compositions more robust and to treat failures. Specifically, we propose the support for fault recovery in service compositions described in PEWS language and executed on PEWS-AM, an graph reduction machine. To support recovery failure on PEWS-AM, we extend the PEWS language specification and adapted the rules of translation and reduction of graphs for this machine. These contributions were made both in the model of abstract machine as at the implementation level
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
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Important issues involving the awakening to the need for conservation of biodiversity and the importance of establishing protected areas as a strategy in pursuit of environmental protection, are increasingly being developed in biological and social investigative fields. In this sense, this research aimed to emphasize the use of environmental perception of social agents are significant elements for the understanding of the man / nature, and develop educational activities aimed at raising awareness and changing attitudes towards environmental issues thus promoting reflections on Environmental Education (EE) as a critical and transformative tool for conservation of rich biological diversity. This research covers as a place of study, schools located in the Environmental Protection Area Jenipabu (APAJ), Rio Grande do Norte. Methodology in general, we highlight the use of questionnaires and mind maps as generators of the contents of empirical research, and execution of content analysis for the treatment of data collected. This dissertation has two chapters in the form of scientific articles, where the first is entitled: "Study of the perceptions and evaluation of interactions concerning environmental education in schools in a conservation area of Rio Grande do Norte - Brazil", obtaining thus a primary diagnosis for analysis about the visions that students and teachers from two schools located in APAJ have on the environment. The second article, entitled: "Effective and analysis of educational activities that promote biodiversity in a coastal area of Environmental Protection Northeast - Brazil" provides an analysis of the educational use of biodiversity as a way to raise awareness of the need for environmental conservation. It appears from research that there is a lack of training in EA by teachers, but there is a need for greater involvement of students in conservation areas, however, from the analysis of educational activities, we observed that the effectiveness of such actions acts to promote awareness and change in actors involved. Thus, environmental education needs to take into account the different perceptions found in each individual, and it can not be based solely on transmission of knowledge, so that we reach a model of conservation.
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The lower course of Piranhas-Assu river, located in the north coast of Rio Grande do Norte, Brazil, arouses a keen interest as a study field, once it concentrates, besides petroleum and gas exploration, activities related to shrimp culture, salt and horticulture, factors that also deserve special attention. Thus, the awareness of the study field environmental stage demands studies from researchers and discernment from society, as a way of understanding the inter-relation between environment and men. Therefore, this work attempts at understanding and studying the dynamics of land use in the lower course of Piranhas-Assu river, through a multitemporal analysis of present and past, accomplishing future projections through simulation models. The work is divided in stages that include the research, analysis, interpretation of results, and the generation of simulation models, to analyze the landscape tendencies, making possible to identify indicators which cause such changes in the lower course of the river. From Geographical Database, the necessary exploratory analyses were accomplished to the following items: land use evolution, natural and environmental vulnerability, multiple geodiversity indexes, and preparation of the data to be used in the simulation model. Later, the construction of the landscape simulation model was conducted. Sequentially, simulations of future sceneries were accomplished through the execution of the model in a specific software environment. Last, the analyses of landscape tendencies in the study field were carried out. The lower course of Piranhas-Assu River didn't show any intense dynamics in landscape changing, once in the period taken into account (from 1988 to 2004) class stability proved to be superior to its transformations. Activities related to agriculture and livestock are the ones that influence, mostly, the landscape dynamics. The production of sea shrimp and petroleum also infers in the landscape, although in smaller proportion. INCRA s public policies excessively determined the dynamics of the landscape in the lower course of Piranhas-Assu River, RN. In respect to its natural vulnerability, the lower course of Piranhas-Assu River, RN, features more vulnerable than stable areas. The landscape simulation, in the first taken period (2004-2009), indicated considerable increases and decreases of antropic activities, if compared to its sequent periods (2009-2014, 2014-2019 and 2019-2024). The simulation, in a wider analysis, showed that the determining factors for the space mobility of antropic activities, in the focused area, are related to the pre-existence of communities with agricultural capability and to the existence of access routes and drainage. Considering the area that features fixed and mobile dunes, located in Porto do Mangue district, we recommend its conversion into a conservation area