Osvaldo N. Oliveira Jr.


Associate Professor at the Instituto de Física de São Carlos, USP - Brazil.
Associated Researcher of NILC
Birth: 13 August, 1960 - Barretos, SP, Brazil.
Married to Maria Cristina F. de Oliveira.
Address:
Instituto de Física de São Carlos, USP
C.P. 369 - 13.560-970 - São Carlos, S.P. - Brazil
Tel. +55 16 2715365 - FAX: +55 16 2713616
e-mail: chu@ifsc.sc.usp.br
BSc. in Physics, Instituto de Física e Química de São Carlos, USP, Brazil, 1982.
MSc in Applied Physics, Instituto de Física e Química de São Carlos, USP - 1984.
Supervisor: Dr. Guilherme F. Leal Ferreira.
PhD at School of Electronic Engineering Science, University of Wales, Bangor, United Kingdom.
Thesis: Electrical Properties of Langmuir Monolayers and Langmuir-Blodgett Deposited Films, 1990.
Supervisor: Prof. D. Martin Taylor.


Research Interests


Langmuir and Langmuir-Blodgett (LB) films and Self-assembled films

The Langmuir-Blodgett (LB) technology was introduced into the Institute of Physics and Chemistry of São Carlos, USP, in 1990 and since then a variety of materials have been used in fundamental studies and in the identification of novel, promising materials for technological applications. With regard to basic properties of Langmuir monolayers, lipids have been used in the investigation of monolayer surface potentials and lateral conductance. LB films have been fabricated from different types of lignin which show a three-dimensional arrangement even within a single monolayer. As for conducting polymers films have been produced from polyaniline and its derivatives using not only the LB technique but also the self-assembly (SA) method. Films produced by either of the techniques show electroactive and optical properties similar to conventional films of PAni. They can be doped and dedoped in a reversible fashion which brings color as well as conductivity changes to the films.

Writing tools (Computational Linguistics)

Case-based reasoning (CBR) is proposed as an appropriate cognitive model for building tutorial systems to help non-native English users in drafting technical papers. We build upon previous experience in developing writing tools for these target users in which reutilization of linguistic material was employed. A case-based support tool, which takes as input a set of rhetorical features and returns some representative texts that satisfy many of the goals according to a metric selected by the user, was tested by Brazilian PhD students in writing Introductory sections of a paper. The results indicated that, at least for this type of user, the CBR model needs to be supplemented with some sort of critiquing system for developing effective learning environments. A proposal is then put forward for a tutorial system which is expected to alleviate many of the non-native speakers' difficulties, especially those arising from mother tongue interference. It is hoped that the process of characterizing rhetorical goals for ne paper may improve the user's ability to identify rhetorical goals in subsequent papers, and also that working with examples of texts that satisfy multiple rhetorical goals may provide understanding of techniques for satisfying multiple goals.

Grammar and style checkers for Brazilian Portuguese

Writing tools dedicated to Brazilian Portuguese texts have so far been limited to spelling checkers and online dictionaries and Thesauri. A grammar checker has been developed using rules based on lexical and semantic markers. The rules were implemented in an iterative way, for their performance was assessed in a corpus of authentic texts with over 30 million words. The tool performance in terms of computational time may be considered as excellent since it equals the performance of commercial tools that have been available for English for a long time. As an example, a PhD thesis with an average size of 130 pages can be checked within only five minutes. The tool already detects a large number of errors, including those related to genre and number of adjectives and nouns, and verb agreement in sentences with canonical order. It cannot cope, however, with some cases of verb agreement in long sentences for which an automatic syntactic analysis is extremely difficult. These difficulties arise mainly from the fact hat the sentence components in Portuguese may appear in different orders, in particular the adjectives. It is also possible for the subject to be absent in a clause. Errors arising from inadequate choice of semantic items are being treated only in very specific, stereotypical cases. Using the tool one can also detect typing errors that are not usually detected in a spelling checker such as unbalanced parentheses. The style and/or the adequacy of a piece of text for a given audience is checked using readability scores, from an adaptation to Brazilian Portuguese of the well-known Flesch scale. The need to adapt the Flesch scale was caused by the large number of latin roots.

List of Publications

Research Team