Abstract
In this paper, we describe a set of compiler analyses and an implementation that automatically map a sequential and un-annotated C program into a pipelined implementation, targeted for an FPGA with multiple external memories. For this purpose, we extend array data-flow analysis techniques from parallelizing compilers to identify pipeline stages, required inter-pipeline stage communication, and opportunities to find a minimal program execution time by trading communication overhead with the amount of computation overlap in different stages. Using the results of this analysis, we automatically generate application-specific pipelined FPGA hardware designs. We use a sample image processing kernel to illustrate these concepts. Our algorithm finds a solution in which transmitting a row of an array between pipeline stages per communication instance leads to a speedup of 1.76 over an implementation that communicates the entire array at once.

Abstract
This paper considers the role of performance and area estimates from behavioral synthesis in design space exploration. We have developed a compilation system that automatically maps high-level algorithms written in C to application-specific designs for Field Programmable Gate Arrays (FPGAs), through a collaboration between parallelizing compiler technology and high-level synthesis tools. Using several code transformations, the compiler optimizes a design to increase parallelism and utilization of external memory band-width, and selects the best design among a set of candidates. Performance and area estimates from behavioral synthesis provide feedback to the compiler to guide this selection. Estimates can be derived far more quickly (up to several orders of magnitude faster) than full synthesis and place-and-route, thus allowing the compiler to consider many more designs than would otherwise be practical. In this paper, we examine the accuracy of the estimates from behavioral synthesis as compared to the fully synthesized designs for a collection of 209 designs for five multimedia kernels. Though the estimates are not completely accurate, our results show that the same design would be selected by the design space exploration algorithm, whether we use estimates or actual results from place-and-route, because it favors smaller designs and only increases complexity when the benefit is significant.

Abstract
Fiber Bragg grating (FBG) written in normal and reduced diameter high birefringence (HiBi) optical fibers have been studied. Chemical etching is used to reduce the fiber diameter while the optical properties of the FBG spectrum are measured. The obtained results agree qualitatively with the stress enhanced chemical etching. They also permit to determine the birefringence of the fiber as a function of the diameter. Optical characterization of the FBG under transversal strain and temperature is performed. The obtained results permit the simultaneous measurement of those parameters with a HiBi FBG sensor.

Abstract
The information contained in companies' financial statements is valuable to several users. Much of the relevant information in such documents is contained in tables and is currently mainly extracted by hand. We propose a method that accomplishes a prior step of the task of automatically extracting information from tables in documents: selecting the lines that are likely to belong to tables. Our method has been developed by empirically analyzing a set of Portuguese companies' financial statements using statistical and data mining techniques. Empirical evaluation indicates that more than 99% of table lines are selected after discarding at least 50% of all lines. The method can cope with the complexity of styles used in assembling information on paper and adapt its performance accordingly, thus maximizing its results.

Abstract
The use of formal probabilistic modelling together with advanced statistical inference in communications engineering, has the potential of providing a powerful workbench for deriving conclusions about the behaviour of systems and sources of data and therefore developing innovative and efficient control and management strategies of communication systems. Targeting the efficient dimensioning of systems and resources in order to make possible the provision of high-quality and larger-choice services to the end-users, this paper proposes the use of a Bayesian framework in video broadband communications. In the context of the combined transmission of several good-quality video sources, such as a digital television broadcast service, using VBR video encoding algorithms and based on prior beliefs and statistical models, an intelligent multiplexer is capable of predicting the probable amount of free space and fill it with extra services or increase the quality of the transmitted channels. © 2003 IEEE.

Abstract
The need of fast algorithms for radial distribution networks that take advantage of their particular structure has been increasing, namely due to the use of genetic algorithms and meta-heuristics for optimization in planning and operation. In this paper, a new method for power flow calculation in radial networks is presented. It uses an iterative process along the branches, in a way similar to other methods, but the main idea is very different from previous approaches, since it is based on the exact power flow solution for a single branch and also because it provides a complete solution (not only voltage magnitudes). The method is fast and robust for different types of networks and loads, including heavy loads. The paper includes the theoretical derivation of the method, an illustration example and tests with benchmarking networks. © 2003 IEEE.