Publicações

AutoElastic: Automatic Resource Elasticity for High Performance Applications in the Cloud

Elasticity is undoubtedly one of the most striking characteristics of cloud computing. Especially in the area of high performance computing (HPC), elasticity can be used to execute irregular and CPU-intensive applications. However, the on- the-fly increase/decrease in resources is more widespread in Web systems, which have their own IaaS-level load balancer. Considering the HPC area, [...]

Using Computational Geometry to Improve Process Rescheduling on Round-Based Parallel Applications

Process rescheduling is a known technique to face with system heterogeneity and dynamism, being especially pertinent on Bulk Synchronous Parallel (BSP) programs. These programs are organized in a set of round-based supersteps, in which the slowest process determines the moment of synchronization. This approach motivated us to develop a first model called MigBSP, which combines [...]

Impact of Thresholds and Load Patterns when Executing HPC Applications with Cloud Elasticity

Elasticity is one of the most known capabilities related to cloud computing, being largely deployed reactively using thresholds. In this way, maximum and minimum limits are used to drive resource allocation and deallocation actions, leading to the following problem statements: How can cloud users set the threshold values to enable elasticity in their cloud applications? [...]

Exploiting Data-Parallelism on Multicore and SMT Systems for Implementing the Fractal Image Compressing Problem

This paper presents a parallel modeling of a lossy image compression method based on the fractal theory and its evaluation over two versions of dual-core processors: with and without simultaneous multithreading (SMT) support. The idea is to observe the speedup on both configurations when changing application parameters and the number of threads at operating system [...]

A model for learning objects adaptation in light of mobile and context-aware computing

The growth usage of mobile technologies and devices such as smartphones and tablets, and the almost ubiquitous wireless communication set the stage for the development of novel kinds of applications. One possibility is exploiting this scenario in the field of education, so creating more intelligent, flexible and customizable systems. Mobile devices can be used to [...]

Joint-analysis of performance and energy consumption when enabling cloud elasticity for synchronous HPC applications

A key characteristic of cloud computing is elasticity, automatically adjusting system resources to an application's workload. Both reactive and horizontal approaches represent traditional means to offer this capability, in which rule‐condition‐action statements and upper and lower thresholds occur to instantiate or consolidate compute nodes and virtual machines. Although elasticity can be beneficial for many HPC [...]

Towards Cloud-based Asynchronous Elasticity for Iterative HPC Applications

Elasticity is one of the key features of cloud computing. It allows applications to dynamically scale computing and storage resources, avoiding over- and under-provisioning. In high performance computing (HPC), initiatives are normally modeled to handle bag-of-tasks or key-value applications through a load balancer and a loosely-coupled set of virtual machine (VM) instances. In the joint-field [...]

A spontaneous social network based on mobile devices

Social networks provide a growing mean of communication that still preserves our human social interaction. Due to the widespread use of mobile devices, and the vast development of applications targeting these platforms, people tend to use their smartphone or tablet as the main way to make that interaction. Furthermore, applications developed to these devices are [...]

On the replacement of objects from round-based applications over heterogeneous environments

In recent years, there has been growing support for more tightly coupled applications regarding heterogeneous resources. A specific way of obtaining better performance in such applications is to consider the replacement of execution entities by newer resources during the application's lifetime. Therefore, this article describes the rationale for developing jMigBSP, which is a Java programming [...]

UbitourAR: A ubiquitous tourism model based on augmented reality.

Nowadays, Brazil has an expected growth in the tourism sector due to the FIFA World Cup (which had a huge success) and the Olympics in Rio de Janeiro. However, there is a lack of tourism applications for Brazil, such as Electronic Tourism Guides (ETGs) for mobile devices. The existence of ETGs that takes into account [...]

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