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Orlando Loques - IEEE Xplore Author Profile

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This work presents a model for managing Virtual Application Servers (VAS) on cluster-based web servers. In addition to providing energy savings, our model has linear scalability and defines a default processing virtual web server, known as Quantum Virtual Machine (QVM). A set of QVM performs a Logical Web Server (LWS), which operates in a flexible manner, changing its performance and power consump...Show More
Many patients use the Internet to find information that can improve their health conditions. In this context, Health Social Networks are acquiring greater force in people's lives by offering them opportunities for social networking to expose questions, experiences, besides new treatments and seek to form relationships giving or receiving emotional support. We developed a Healthcare Social Network ...Show More
This paper presents the Quantum Mapper (QMapper), a model for managing Virtual Application Servers (VAS) on cluster-based web servers. In addition to providing energy savings and maintenance of the QoS of the cluster applications, the QMapper has linear scalability and defines a small-capacity processing virtual web server, known as Quantum VAS (QVAS). A QVAS operates in a flexible manner, changin...Show More
A homecare system should adapt to changes regarding the patient needs and to variations in the residential environment. This requires a software architecture designed to support customizations before the deployment (static variability) and changes during the system operation (dynamic variability). We present a comprehensive approach in which both kinds of variabilities are seamless described by me...Show More
The current trend to move from homogeneous to heterogeneous multi-core systems promises further performance and energy-efficiency benefits. A typical future heterogeneous multi-core system includes two distinct types of cores, such as high performance sophisticated ("large'') cores and simple low-power ("small'') cores. In those heterogeneous platforms, execution phases of application threads that...Show More
In service discovery protocols for mobile ad hoc networks (Manets) assisting emergency search and rescue missions, a key problem is to keep the system operating despite the existence of faults. In this paper, we propose a fault-tolerant service discovery mechanism based on localization that considers the requesting node's localization, the request response time and the maximum node speed to guaran...Show More
This paper proposes and evaluates an approach for power and performance management in virtualized server clusters. The major goal of our approach is to reduce power consumption in the cluster while meeting performance requirements. The contributions of this paper are: (1) a simple but effective way of modeling power consumption and capacity of servers even under heterogeneous and changing workload...Show More
Software product lines capture commonalities and variabilities of products in order to facilitate the process development of new products. However, variability management is traditionally done just in development time and deployment time, not attending classes of applications that require a high degree of adaptability such as ubiquitous/pervasive and context-aware applications. This paper presents...Show More
Ubiquitous and pervasive applications are aware of the context of the used resources. This class of application can benefit from mechanisms to discover resources (devices and sensors) that meet their requirements and mechanisms to monitor the state and provide access to the functionalities of these resources. We present an architecture that includes two essential services to compose the supporting...Show More
Fault tolerance is a constant concern in data centers where servers have to run with a minimal level of failures. Changes on the operating conditions or on server demands, and variations of the systems own failure rate have to be handled in such a way that SLAs are honored and services are not interrupted. We present an approach to handle fault tolerance requirements, based on component replicatio...Show More
We present a decision-level data fusion technique for monitoring and reporting critical health conditions of a hypertensive patient at home. Variables associated to the patient (physiological and behavioral) and to the living environment are considered in the solution, contributing to improve the confidence on the system outputs. In the paper, we model the problem variables as fuzzy, aiming to cap...Show More
Service selection in service discovery protocols has an important effect on wireless multi-hop ad hoc networks (MANETs) performance. This work proposes a service selection mechanism based on localization to reduce the redundant replies in these protocols. The mechanism dynamically selects the best resource providers during the reply transmissions taking into account geographic distance, speed and ...Show More
The authors discuss the development of their Parallel Reconfigurable Interconnectable Object (P-RIO) environment, which offers a graphical programming tool, modular construction, high portability, a separate configuration language, and runtime support mechanisms for parallel programs. P-RIO provides a middleware-based environment for parallel and distributed programming. Its object-based, software...Show More
This paper presents P-RIO, a parallel programming environment that supports an object based software configuration methodology. It promotes a clear separation of the individual sequential computation components from the interconnection structure used for the interaction between these components. This makes the data and control interactions explicit, simplifying program visualization and understand...Show More
Distributed application systems are built to meet functional and non-functional requirements (such as availability, reliability, security, real-time). This can be obtained constructing an application specific operating system to support the non-functional requirements. Nowadays, an attractive approach is to extend a standard support environment in order to include the extra mechanisms required. Th...Show More
A protocol based on an extension of the CSMA/CD (carrier sense multiple access with collision detection) access control technique, which provides guaranteed message transport time, is presented. Measured performance data and analytical studies based on a maximum traffic load model of the network were used to demonstrate the bounded message transport time features of the protocol. An analytical mod...Show More