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Publications

Publications by HumanISE

2009

Propagating Fine-Grained Topic Labels in News Snippets

Authors
Sarmento, L; Nunes, S; Teixeira, J; Oliveira, E;

Publication
2009 IEEE/WIC/ACM INTERNATIONAL JOINT CONFERENCES ON WEB INTELLIGENCE (WI) AND INTELLIGENT AGENT TECHNOLOGIES (IAT), VOL 3

Abstract
We propose an unsupervised method for propagating automatically extracted fine-grained topic labels among news items to improve their topic description for subsequent text classification procedure. This method compares vector representations of news items and assigns to each news item the label of its closest neighbour with a different topic label. Results obtained show that high precision can be achieved in propagating the top ranked topic label, and that 2-gram and 3-gram feature representations optimize the precision.

2009

Unbalanced FIFO sorting for FPGA-based systems

Authors
Marcelino, R; Neto, HC; Cardoso, JMP;

Publication
16th IEEE International Conference on Electronics, Circuits, and Systems, ICECS 2009, Yasmine Hammamet, Tunesia, 13-19 December, 2009

Abstract
Sorting is an important operation in a myriad of applications. It can contribute substantially to the overall execution time of an application. Dedicated sorting architectures can be used to accelerate applications and/or to reduce energy consumption. In this paper, we propose an efficient sorting unit aiming at acceleratin. The sort operation in FPGA-based embedded systems. The proposed sorting unit, named Unbalanced FIFO Merge Sorting Unit, is based on a FIFO merger implementation and is easily scalable to handle different data-set sizes. We show results oy the proposed sorting unit when isolated and when integrated in a software/hardware solution. When using a Xilinx Virtex-5 SX50T FPGA device. The logic resources for a 32 Kword machine is lower than 1%, an. The block RAM usage is about 22%. When compared to a quicksort pure software implementation, our Sorting Unit provides speed-ups from 1.2× to 50× and about 20× when isolated and when integrated in a software/hardware solution, respectively. © 2009 IEEE.

2009

LALP: A Novel Language to Program Custom FPGA-based Architectures

Authors
Menotti, R; Cardoso, JMP; Fernandes, MM; Marques, E;

Publication
PROCEEDINGS OF THE 21ST INTERNATIONAL SYMPOSIUM ON COMPUTER ARCHITECTURE AND HIGH PERFORMANCE COMPUTING

Abstract
Field-Programmable Gate Arrays (FPGAs) are becoming increasingly important in embedded and high-performance computing systems. They allow performance levels close to the ones obtained from Application-Specific Integrated Circuits (ASICs), while still keeping design and implementation flexibility. However to efficiently program FPGAs, one needs the expertise of hardware developers and to master hardware description languages (HDLs) such as VHDL or Verilog. The attempts to furnish a high-level compilation flow (e.g., front C programs) still have open issues before efficient and consistent results can be obtained. Bearing in mind the FPGA resources, we have developed LALP, a novel language to program FPGAs. A compilation framework including mapping capabilities supports the language. The main ideas behind LALP is to provide a higher abstraction level than HDLs, to exploit the intrinsic parallelism of hardware resources, and to permit the programmer to control execution stages whenever the compiler techniques are unable to generate efficient implementations. In this paper we describe LALP, and show how it can be used to achieve high-performance computing solutions.

2009

AUTOMATIC GENERATION OF FPGA HARDWARE ACCELERATORS USING A DOMAIN SPECIFIC LANGUAGE

Authors
Menotti, R; Cardoso, JMP; Fernandes, MM; Marques, E;

Publication
FPL: 2009 INTERNATIONAL CONFERENCE ON FIELD PROGRAMMABLE LOGIC AND APPLICATIONS

Abstract
This paper describes an alternative approach to direct mapping loops described in high-level languages onto FPGAs. Different from other approaches, this technique does not inherit from software pipelining techniques. The control is distributed over operations, thus a finite state machine is not necessary to control the order of operations, allowing efficient hardware implementations. The specification of a hardware block is done by means of LALP, a domain specific language specially designed to help the application of the techniques. While the language syntax resembles C, it contains certain constructs that allow programmer interventions to enforce or relax data dependences as needed, and so optimize the performance of the generated hardware blocks.

2009

A Comparison of Three Representative Hardware Sorting Units

Authors
Marcelino, R; Neto, HC; Cardoso, JMP;

Publication
IECON: 2009 35TH ANNUAL CONFERENCE OF IEEE INDUSTRIAL ELECTRONICS, VOLS 1-6

Abstract
Sorting is an important operation for many embedded computing systems. Since sorting large datasets may slowdown the overall execution, schemes to speedup sorting operations are needed. Bearing in mind the hardware acceleration of sorting, we show in this paper an analysis and comparison among three hardware sorting units: Sorting Network, Insertion Sorting, and FIFO-based Merge Sorting. We focus on embedded computing systems implemented with FPGAs, which give us the flexibility to accommodate customized hardware sorting units. We also present a hardware/software solution for sorting data sets with size larger than the size of the sorting unit. This hardware/software solution achieves 20x overall speedup over a pure software implementation of the well-known quicksort algorithm.

2009

Compilation Techniques for Reconfigurable Architectures

Authors
Cardoso, JM; Diniz, PC;

Publication

Abstract

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