Pierre Baldi

Pierre Baldi

orcid

Research Focus & Metrics

Academic Career Length

28Years (1999-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

View All Publications
1 May 2000 in Bioinformatics
Verified
Journal Article
Open access
PDF file
PBPierre Baldi
Pierre Baldi
SBSøren Brunak
Søren Brunak
YCYves Chauvin
Yves Chauvin
CAClaus A. F. Andersen
Claus A. F. Andersen
HNHenrik Nielsen
Henrik Nielsen
4 Also at the Department of Biological Sciences, University of California, Irvine, USA, to whom all correspondence should be addressed. We provide a unified overview of methods that currently are widely used to assess the accuracy of prediction algorithms, from raw percentages, quadratic error measures and other distances, and correlation coefficients, and to information theoretic measures such as relative entropy and mutual information. We briefly discuss the advantages and disadvantages of each approach. For classification tasks, we derive new learning algorithms for the design of prediction systems by directly optimising the correlation coefficient. We observe and prove several results relating sensitivity and specificity of optimal systems. While the principles are general, we illustrate the applicability on specific problems such as protein secondary structure and signal peptide prediction. Contact: pfbaldi@ics.uci.edu

10 August 2018 in IEEE Transactions on Industrial Informatics
Verified
Journal Article
Closed access
SSSiyu Shao
Siyu Shao
SMStephen McAleer
Stephen McAleer
RYRuqiang Yan
Ruqiang Yan
PBPierre Baldi
Pierre Baldi
We develop a novel deep learning framework to achieve highly-accurate machine fault diagnosis using transfer learning to enable and accelerate the training of deep neural network. Compared with existing methods, the proposed method is faster to train and more accurate. First, original sensor data are converted to images by conducting a Wavelet transformation to obtain time-frequency distributions. Next, a pre-trained network is used to extract lower level features. The labeled time-frequency images are then used to fine-tune the higher-levels of the neural network architecture. This paper creates a machine fault diagnosis pipeline and experiments are carried out to verify the effectiveness and generalization of the pipeline on three main mechanical datasets including induction motors, gearboxes, and bearings with sizes of 6,000, 9,000, and 5,000 time series samples, respectively. We achieve state-of-the-art results on each dataset, with most datasets showing test accuracy near 100%, and in the gearbox dataset, we achieve significant improvement from 94.8% to 99.64%. We created a repository including these datasets located at mlmechanics.ics.uci.edu.

1 June 2001 in Bioinformatics
Verified
Journal Article
Open access
PDF file
PBPierre Baldi
Pierre Baldi
ALAnthony D. Long
Anthony D. Long
Motivation: DNA microarrays are now capable of providing genome-wide patterns of gene expression across many different conditions. The first level of analysis of these patterns requires determining whether observed differences in expression are significant or not. Current methods are unsatisfactory due to the lack of a systematic framework that can accommodate noise, variability, and low replication often typical of microarray data. Results: We develop a Bayesian probabilistic framework for microarray data analysis. At the simplest level, we model log-expression values by independent normal distributions, parameterized by corresponding means and variances with hierarchical prior distributions. We derive point estimates for both parameters and hyperparameters, and regularized expressions for the variance of each gene by combining the empirical variance with a local background variance associated with neighboring genes. An additional hyperparameter, inversely related to the number of empirical observations, determines the strength of the background variance. Simulations show that these point estimates, combined with a t -test, provide a systematic inference approach that compares favorably with simple t -test or fold methods, and partly compensate for the lack of replication. Availability: The approach is implemented in software called Cyber-T accessible through a Web interface at www.genomics.uci.edu/software.html. The code is available as Open Source and is written in the freely available statistical language R. Contact: pfbaldi@ics.uci.edu; tdlong@uci.edu

1 June 2009 in Vision Research
Verified
Journal Article
Closed access
LILaurent Itti
Laurent Itti
PBPierre Baldi
Pierre Baldi

21 December 2005 in Proteins: Structure, Function, and Bioinformatics
Verified
Journal Article
Closed access
PDF file
Jianlin ChengJianlin Cheng
Jianlin Cheng
ARArlo Randall
Arlo Randall
PBPierre Baldi
Pierre Baldi

1 July 2005 in Nucleic Acids Research
Verified
Journal Article
Open access
JCJ. Cheng
J. Cheng
ARA. Z. Randall
A. Z. Randall
MSM. J. Sweredoski
M. J. Sweredoski
PBPierre Baldi
Pierre Baldi
SCRATCH is a server for predicting protein tertiary structure and structural features. The SCRATCH software suite includes predictors for secondary structure, relative solvent accessibility, disordered regions, domains, disulfide bridges, single mutation stability, residue contacts versus average, individual residue contacts and tertiary structure. The user simply provides an amino acid sequence and selects the desired predictions, then submits to the server. Results are emailed to the user. The server is available at http://www.igb.uci.edu/servers/psss.html.