Tvoice :um sistema de manipulação de linguagens para auxiliar portadores de necessidades especiais através da web

This work presents the tVoice, software that manipulates tags languages, extracting information and, being integral part of the VoiceProxy system, it aids bearers of special needs in the access to the Web. This system is responsible for the search and treatment of the documents in the Web, extracting the textual information contained in those documents and preceding the capability of generating eventually through translation techniques, an audio script, used by the of interface subsystem of VoiceProxy, the iVoice, in the process of voice synthesis. In this stage the tVoice, besides the treatment of the tag language HTML, processes other two formats of documents, PDF and XHTML. Additionally to allow that, besides the iVoice, other interface subsystems can make use of the tVoice through remote access, we propose distribution systems techniques based in the model Client-Server providers operations of the fashion of a proxy server treatment of documents

Um serviço de certificação digital para plataformas de middleware

Nowadays due to the security vulnerability of distributed systems, it is needed mechanisms to guarantee the security requirements of distributed objects communications. Middleware Platforms component integration platforms provide security functions that typically offer services for auditing, for guarantee messages protection, authentication, and access control. In order to support these functions, middleware platforms use digital certificates that are provided and managed by external entities. However, most middleware platforms do not define requirements to get, to maintain, to validate and to delegate digital certificates. In addition, most digital certification systems use X.509 certificates that are complex and have a lot of attributes. In order to address these problems, this work proposes a digital certification generic service for middleware platforms. This service provides flexibility via the joint use of public key certificates, to implement the authentication function, and attributes certificates to the authorization function. It also supports delegation. Certificate based access control is transparent for objects. The proposed service defines the digital certificate format, the store and retrieval system, certificate validation and support for delegation. In order to validate the proposed architecture, this work presents the implementation of the digital certification service for the CORBA middleware platform and a case study that illustrates the service functionalities

Um algoritmo paralelo eficiente de migração reversa no tempo (rtm) 3d com granularidade fina

The reverse time migration algorithm (RTM) has been widely used in the seismic industry to generate images of the underground and thus reduce the risk of oil and gas exploration. Its widespread use is due to its high quality in underground imaging. The RTM is also known for its high computational cost. Therefore, parallel computing techniques have been used in their implementations. In general, parallel approaches for RTM use a coarse granularity by distributing the processing of a subset of seismic shots among nodes of distributed systems. Parallel approaches with coarse granularity for RTM have been shown to be very efficient since the processing of each seismic shot can be performed independently. For this reason, RTM algorithm performance can be considerably improved by using a parallel approach with finer granularity for the processing assigned to each node. This work presents an efficient parallel algorithm for 3D reverse time migration with fine granularity using OpenMP. The propagation algorithm of 3D acoustic wave makes up much of the RTM. Different load balancing were analyzed in order to minimize possible losses parallel performance at this stage. The results served as a basis for the implementation of other phases RTM: backpropagation and imaging condition. The proposed algorithm was tested with synthetic data representing some of the possible underground structures. Metrics such as speedup and efficiency were used to analyze its parallel performance. The migrated sections show that the algorithm obtained satisfactory performance in identifying subsurface structures. As for the parallel performance, the analysis clearly demonstrate the scalability of the algorithm achieving a speedup of 22.46 for the propagation of the wave and 16.95 for the RTM, both with 24 threads.

Uma abordagem na camada de middleware para troca dinâmica de componentes em sistemas multimídia distribuídos baseados no framework Cosmos

To manage the complexity associated with the management of multimedia distributed systems, a solution must incorporate concepts of middleware in order to hide specific hardware and operating systems aspects. Applications in these systems can be implemented in different types of platforms, and the components of these systems must interact each with the other. Because of the variability of the state of the platforms implementation, a flexible approach should allow dynamic substitution of components in order to ensure the level of QoS of the running application . In this context, this work presents an approach in the layer of middleware that we are proposing for supporting dynamic substitution of components in the context the Cosmos framework , starting with the choice of target component, rising taking the decision, which, among components candidates will be chosen and concluding with the process defined for the exchange. The approach was defined considering the Cosmos QoS model and how it deals with dynamic reconfiguration

Um framework baseado em modelos para desenvolvimento de sistemas multimídia distribuídos autoadaptativos

Distributed multimedia systems have highly variable characteristics, resulting in new requirements while new technologies become available or in the need for adequacy in accordance with the amount of available resources. So, these systems should provide support for dynamic adaptations in order to adjust their structures and behaviors at runtime. This paper presents an approach to adaptation model-based and proposes a reflective and component-based framework for construction and support of self-adaptive distributed multimedia systems, providing many facilities for the development and evolution of such systems, such as dynamic adaptation. The propose is to keep one or more models to represent the system at runtime, so some external entity can perform an analysis of these models by identifying problems and trying to solve them. These models integrate the reflective meta-level, acting as a system self-representation. The framework defines a meta-model for description of self-adaptive distributed multimedia applications, which can represent components and their relationships, policies for QoS specification and adaptation actions. Additionally, this paper proposes an ADL and architecture for model-based adaptation. As a case study, this paper presents some scenarios to demonstrate the application of the framework in practice, with and without the use of ADL, as well as check some characteristics related to dynamic adaptation

MoSAC: um módulo para seleção de configurações arquiteturais baseado em critérios de QoS no contexto de sistema distribuídos autoadaptativos

The process for choosing the best components to build systems has become increasingly complex. It becomes more critical if it was need to consider many combinations of components in the context of an architectural configuration. These circumstances occur, mainly, when we have to deal with systems involving critical requirements, such as the timing constraints in distributed multimedia systems, the network bandwidth in mobile applications or even the reliability in real-time systems. This work proposes a process of dynamic selection of architectural configurations based on non-functional requirements criteria of the system, which can be used during a dynamic adaptation. This proposal uses the MAUT theory (Multi-Attribute Utility Theory) for decision making from a finite set of possibilities, which involve multiple criteria to be analyzed. Additionally, it was proposed a metamodel which can be used to describe the application s requirements in terms of the non-functional requirements criteria and their expected values, to express them in order to make the selection of the desired configuration. As a proof of concept, it was implemented a module that performs the dynamic choice of configurations, the MoSAC. This module was implemented using a component-based development approach (CBD), performing a selection of architectural configurations based on the proposed selection process involving multiple criteria. This work also presents a case study where an application was developed in the context of Digital TV to evaluate the time spent on the module to return a valid configuration to be used in a middleware with autoadaptative features, the middleware AdaptTV

Um modelo de interconexão de componentes para ambientes mulitmídia distribuídos

Multimedia systems must incorporate middleware concepts in order to abstract hardware and operational systems issues. Applications in those systems may be executed in different kinds of platforms, and their components need to communicate with each other. In this context, it is needed the definition of specific communication mechanisms for the transmission of information flow. This work presents a interconnection component model for distributed multimedia environments, and its implementation details. The model offers specific communication mechanisms for transmission of information flow between software components considering the Cosmos framework requirements in order to support component dynamic reconfiguration

Um modelo de interconexão de componentes para ambientes mulitmídia distribuídos

Multimedia systems must incorporate middleware concepts in order to abstract hardware and operational systems issues. Applications in those systems may be executed in different kinds of platforms, and their components need to communicate with each other. In this context, it is needed the definition of specific communication mechanisms for the transmission of information flow. This work presents a interconnection component model for distributed multimedia environments, and its implementation details. The model offers specific communication mechanisms for transmission of information flow between software components considering the Cosmos framework requirements in order to support component dynamic reconfiguration

Proteção em sistemas elétricos com geração distribuída utilizando a transformada wavelet

A typical electrical power system is characterized by centr alization of power gene- ration. However, with the restructuring of the electric sys tem, this topology is changing with the insertion of generators in parallel with the distri bution system (distributed gene- ration) that provides several benefits to be located near to e nergy consumers. Therefore, the integration of distributed generators, especially fro m renewable sources in the Brazi- lian system has been common every year. However, this new sys tem topology may result in new challenges in the field of the power system control, ope ration, and protection. One of the main problems related to the distributed generati on is the islanding formation, witch can result in safety risk to the people and to the power g rid. Among the several islanding protection techniques, passive techniques have low implementation cost and simplicity, requiring only voltage and current measuremen ts to detect system problems. This paper proposes a protection system based on the wavelet transform with overcur- rent and under/overvoltage functions as well as infomation of fault-induced transients in order to provide a fast detection and identification of fault s in the system. The propo- sed protection scheme was evaluated through simulation and experimental studies, with performance similar to the overcurrent and under/overvolt age conventional methods, but with the additional detection of the exact moment of the fault.