Abstract

Abstract
This article presents an approach to enrich the MATLAB(1) language with aspect-oriented modularity features, enabling developers to experiment different implementation characteristics and to acquire runtime data and traces without polluting their base MATLAB code. We propose a language through which programmers configure the low-level data representation of variables and expressions. Examples include specifically-tailored fixed-point data representations leading to more efficient support for the underlying hardware, e.g., digital signal processors and application-specific architectures, without built-in floating point units. This approach assists developers in adding handlers and monitoring features in a non-invasive way as well as configuring MATLAB functions with optimized implementations. Different aspect modules can be used to retarget common MATLAB code bases for different purposes and implementations. We validate the proposed approach with a set of representative examples where we attain a simple way to explore a number of properties. Experiment results and collected aspect-oriented software metrics lend support to the claims on its usefulness.

Abstract
IEEE 802.11-based Stub Wireless Mesh Networks (WMNs) are a cost-effective and flexible solution to extend wired network infrastructures. Yet, they suffer from two major problems: inefficiency and unfairness. A number of approaches have been proposed to tackle these problems, but they are too restrictive, highly complex, or require time synchronization and modifications to the IEEE 802.11 MAC. PACE is a simple multi-hop scheduling mechanism for Stub WMNs overlaid on the IEEE 802.11 MAC that jointly addresses the inefficiency and unfairness problems. It limits transmissions to a single mesh node at each time and ensures that each node has the opportunity to transmit a packet in each network-wide transmission round. Simulation results demonstrate that PACE can achieve optimal network capacity utilization and greatly outperforms state of the art CSMA/CA-based solutions as far as goodput, delay, and fairness are concerned.

Abstract
Metadata production for research datasets is not a trivial problem. Standardized descriptors are convenient for interoperability, but each area requires specific descriptors in order to guarantee metadata comprehensiveness and accuracy. In this paper, we report on an ongoing research data management experience at the University of Porto (U. Porto), which led to the proposal of a domain-specific application profile. We presented two curation tools to a group of researchers from mechanical engineering, to help them manage and describe their datasets. After monitoring their interactions with the solutions and analyzing the needs of the group, we were able to select a subset of qualified Dublin Core (DC), as well as a set of complementary descriptors, to capture the main aspects of their experiments. The resulting application profile combines generic, standardized DC descriptors with descriptors from a different experimental standard, and introduces extra domain-specific ones. The profile has been validated by the researchers and is now being used in the description of their datasets. © DCMI 2013.

Abstract

Abstract