INESC-ID

About: INESC-ID is a nonprofit organization based out in Lisbon, Portugal. It is known for research contribution in the topics: Computer science & Context (language use). The organization has 932 authors who have published 2618 publications receiving 37658 citations.

TAU 2013 variation aware timing analysis contest

Abstract: Timing analysis is a key component of any integrated circuit (IC) chip design-closure flow, and is employed at various stages of the flow including pre/post-route timing optimization and timing signoff. While accurate timing analysis is important, the run-time of the analysis is equally critical with growing chip design sizes and complexity (for example, increasing number of clocks domains, voltage islands, etc.). In addition, the increasing significance of variability in the chip manufacturing process as well as environmental variability necessitates use of variation aware techniques (e.g. statistical, multi-corner) for chip timing analysis which significantly impacts the analysis run-time.The aim of the TAU 2013 variation aware timing contest is to seek novel ideas for fast variation aware timing analysis, by means of the following: (a) increase awareness of variation aware timing analysis and provide insight into some challenging aspects of the analysis, (b) encourage novel parallelization techniques (including multi-threading) for timing analysis, and (c) facilitate creation of a publicly available variation aware timing analysis framework and benchmarks to further advance research in this area.

Cross-layer caching based optimization for wireless multimedia sensor networks

Abstract: Traditional transport layer protocols have been designed to perform end-to-end error control transparently to the intermediate nodes (e.g., TCP). However, the resource constraints featured by Wireless Sensor Network (WSN) require a different paradigm where intermediate nodes are able to cache packets and if possible retransmit them on-demand to avoid incurring costly end-to-end retransmissions. Lately, wireless multimedia sensor network (WMSN) is being considered as a new research area wherebyWSNs are targeted for the delivery of multimedia traffic. In this paper, we propose a NACK-based repair mechanism coupled with an adaptive MAC layer retransmission scheme in order to improve the performance of the transport protocols. Specifically, our goal is to be able to reduce real-time end-to-end delay while maintaining reliability and energy efficiency in the presence of high channel error rates. Our simulation results show that the ensemble of both mechanisms provides better good-put performance while simultaneously improving energy efficiency. Furthermore, the improved protocol also achieves lower deadline miss ratios which makes it suitable for multimedia transport. While we demonstrate the effectiveness of the mechanisms by incorporating them into the basic Distributed Transport for Sensor Networks (DTSN) protocol, they are generic enough to be applicable to other WSN transport protocols.

EpiLog: A software for the logical modelling of epithelial dynamics.

Abstract: Cellular responses are governed by regulatory networks subject to external signals from surrounding cells and to other micro-environmental cues. The logical (Boolean or multi-valued) framework proved well suited to study such processes at the cellular level, by specifying qualitative models of involved signalling pathways and gene regulatory networks. Here, we describe and illustrate the main features of EpiLog, a computational tool that implements an extension of the logical framework to the tissue level. EpiLog defines a collection of hexagonal cells over a 2D grid, which embodies a mono-layer epithelium. Basically, it defines a cellular automaton in which cell behaviours are driven by associated logical models subject to external signals. EpiLog is freely available on the web at http://epilog-tool.org . It is implemented in Java (version ≥1.7 required) and the source code is provided at https://github.com/epilog-tool/epilog under a GNU General Public License v3.0.

Fast and reliable passivity assessment and enforcement with extended Hamiltonian pencil

Abstract: Passivity is an important property for a macro-model generated from measured or simulated data. Existence of purely imaginary eigenvalues of a Hamiltonian matrix provides useful information in assessing and correcting the passivity of a system. Since direct computation of eigenvalues is very expensive for large-scale systems, several authors have proposed to solve iteratively for a subset of the eigenvalues based on heuristic sampling along the imaginary axis. However, completeness is not guaranteed in such methods and thus potential risk of missing important eigenvalues is difficult to avoid. In this paper we are aiming at finding all eigenvalues efficiently to avoid both the high cost and the potential risk of missing important eigenvalues. The idea of the proposed method is to convert the Hamiltonian matrix to an equivalent sparse form, termed the "extended Hamiltonian pencil", and solve for its eigenvalues efficiently using a special eigensolver. Experiments on several realistic systems demonstrate an 80X speed-up compared with standard direct eigensolvers.