2013
Autores
Paulino, N; Ferreira, JC; Cardoso, JMP;
Publicação
RECONFIGURABLE COMPUTING: ARCHITECTURES, TOOLS AND APPLICATIONS
Abstract
This paper presents an extension to a hardware/software system architecture in which repetitive instruction traces, called Megablocks, are accelerated by a Reconfigurable Processing Unit (RPU). This scheme is supported by a custom toolchain able to automatically generate a RPU tailored for the execution of one or more Megablocks detected offline. Switching between hardware and software execution is done transparently, without modifications to source code or executable binaries. Our approach has been evaluated using an architecture with a MicroBlaze General Purpose Processor (GPP) softcore. By using a memory sharing mechanism, the RPU can access the GPP's data memory, allowing the acceleration of Megablocks with load/store operations. For a set of 21 embedded benchmarks, an average speedup of 1.43x is achieved, and a potential speedup of 2.09x is predicted for an implementation using a low overhead interface for communication between GPP and RPU.
2013
Autores
Barbosa, FS; Aguiar, A;
Publicação
Aspect-Oriented Software Development, AOSD '13, Fukuoka, Japan, March 24-29, 2013
Abstract
In object oriented languages the problem of crosscutting concerns, due to limitations in the composition mechanisms, is recurrent. In order to reduce this problem we propose to use roles as a way of composing classes that extends the Object Oriented approach and can be used to model crosscutting concerns. To support our approach we developed a role language that extends Java, while being compatible with existing virtual machines. As validation we conducted a case study using three open source systems. We identified crosscutting concerns in the systems and then modeled them using our role approach. Results show that roles are a viable option for modeling crosscutting concerns. Copyright © 2013 ACM.
2013
Autores
Domingues, MA; Soares, C; Jorge, AM;
Publicação
INFORMATION SYSTEMS AND E-BUSINESS MANAGEMENT
Abstract
The goal of many web portals is to select, organize and distribute content in order to satisfy its users/customers. This process is usually based on meta-data that represent and describe content. In this paper we describe a methodology and a system to monitor the quality of the meta-data used to describe content in web portals. The methodology is based on the analysis of the meta-data using statistics, visualization and data mining tools. The methodology enables the site's editor to detect and correct problems in the description of contents, thus improving the quality of the web portal and the satisfaction of its users. We also define a general architecture for a system to support the proposed methodology. We have implemented this system and tested it on a Portuguese portal for management executives. The results validate the methodology proposed.
2013
Autores
Schaller, J; Valente, JMS;
Publicação
JOURNAL OF THE OPERATIONAL RESEARCH SOCIETY
Abstract
This paper presents several procedures for developing non-delay schedules for a permutation flow shop with family setups when the objective is to minimize total earliness and tardiness. These procedures consist of heuristics that were found to be effective for minimizing total tardiness in flow shops without family setups, modified to consider family setups and the total earliness and tardiness objective. These procedures are tested on several problem sets with varying conditions. The results show that variable greedy algorithms are effective when solving small problems, but using a genetic algorithm that includes a neighbourhood defined by the sequence of batches of jobs belonging to the same set-up family is effective when solving medium- or large-sized problems. The results also show that if setup times can be reduced a significant reduction in total earliness and tardiness could result.
2013
Autores
Macedo, N; Guimaraes, T; Cunha, A;
Publicação
2013 28TH IEEE/ACM INTERNATIONAL CONFERENCE ON AUTOMATED SOFTWARE ENGINEERING (ASE)
Abstract
Models are paramount in model-driven engineering. In a software project many models may coexist, capturing different views of the system or different levels of abstraction. A key and arduous task in this development method is to keep all such models consistent, both with their meta-models (and the respective constraints) and among themselves. This paper describes Echo, a tool that aims at simplifying this task by automating inconsistency detection and repair using a solver based engine. Consistency between different models can be specified by bidirectional model transformations, and is guaranteed to be recovered by minimal updates on the inconsistent models. The tool is freely available as an Eclipse plugin, developed on top of the popular EMF framework, and supports constraints and transformations specified in the OMG standard languages OCL and QVT-R, respectively.
2013
Autores
Queiros, R; Leal, JP;
Publicação
SOFTWARE-PRACTICE & EXPERIENCE
Abstract
A repository of learning objects is a system that stores electronic resources in a technology-mediated learning process. The need for this kind of repository is growing as more educators become eager to use digital educational contents and more of it becomes available. The sharing and use of these resources relies on the use of content and communication standards as a means to describe and exchange educational resources, commonly known as learning objects. This paper presents the design and implementation of a service-oriented repository of learning objects called crimsonHex. This repository supports new definitions of learning objects for specialized domains and we illustrate this feature with the definition of programming exercises as learning objects and its validation by the repository. The repository is also fully compliant with existing communication standards and we propose extensions by adding new functions, formalizing message interchange and providing a REST interface. To validate the interoperability features of the repository, we developed a repository plug-in for Moodle that is expected to be included in the next release of this popular learning management system. Copyright (c) 2012 John Wiley & Sons, Ltd.
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