Solving the linear interval tolerance problem for weight initialization of neural networks

Determining good initial conditions for an algorithm used to train a neural network is considered a parameter estimation problem dealing with uncertainty about the initial weights. Interval Analysis approaches model uncertainty in parameter estimation problems using intervals and formulating tolerance problems. Solving a tolerance problem is defining lower and upper bounds of the intervals so that the system functionality is guaranteed within predefined limits. The aim of this paper is to show how the problem of determining the initial weight intervals of a neural network can be defined in terms of solving a linear interval tolerance problem. The proposed Linear Interval Tolerance Approach copes with uncertainty about the initial weights without any previous knowledge or specific assumptions on the input data as required by approaches such as fuzzy sets or rough sets. The proposed method is tested on a number of well known benchmarks for neural networks trained with the back-propagation family of algorithms. Its efficiency is evaluated with regards to standard performance measures and the results obtained are compared against results of a number of well known and established initialization methods. These results provide credible evidence that the proposed method outperforms classical weight initialization methods

Comparison of the Hansen-Sengupta and the Frommer-Lang-Schnurr Existence Tests

International audienc

Mitochondrial Transport Proteins

Mitochondrial transporters are membrane-inserted proteins which provide a link between metabolic reactions occurring within the mitochondrial matrix and outside the organelles by catalyzing the translocation of numerous solutes across the mitochondrial membrane. They include the mitochondrial carrier family members, the proteins involved in pyruvate transport, ABC transporters and channels, and are, therefore, essential for many biological processes and cell homeostasis. Identification and functional studies of many mitochondrial transporters have been performed over the years using both in vitro and in vivo systems. The few recently solved structures of these transporters have paved the way for further investigations. Furthermore, alterations in their function are responsible for several diseases