12306777
A single spike model of predictive coding
22666885
A single-spike model of predictive coding
Abstract The standard cortical model assumes that the meaning of a neuron's signal is contained in its firing rate. While that model has been used to interpret a voluminous amount of experimental data, it does not address the question of timing, or how recipient neurons can decode this signal in time to predict behavioral results. We propose a model based on coincident firing of large groups of neurons. We show using an example of predictive coding, how the cortex can support vast amounts of non-interfering parallel computation.
205118346
Coding for Write-Efficient Memory
We introduce write-efficient memories (WEM) as a new model for storing and updating information on a rewritable medium. There is a cost ϕ: X × X → R∞ assigned to changes of letters. A collection of subsets C = {Ci: 1 ≤ i ≤ M} of Xn is an (n, M, D) WEM code, if Ci ∩ Cj = ⊘ for all i ≠ j and if 
Dmax= maxl⩽i,j⩽MxnϵCjYnϵC1 max min ∑j=1nϕ(xt, yt)⩽D 
. Dmax is called the maximal correction cost with respect to the given cost function. The performance of a code C can also be measured by two parameters, namely, the maximal cost per letter dC = n−1Dmax and the rate of the size rC = n−1 log M. The rate achievable with a maximal per letter cost d is thus 
R(d)=supc:dc⩽drc 
. This is the most basic quantity (the storage capacity) of a WEM (Xn, ϕn)n = 1∞. We give a characterization of this and related quantities.
6686875
Comparison between geometry-based and Gabor-wavelets-based facial expression recognition using multi-layer perceptron
The authors investigate the use of two types of features extracted from face images for recognizing facial expressions. The first type is the geometric positions of a set of fiducial points on a face. The second type is a set of multi-scale and multi-orientation Gabor wavelet coefficients extracted from the face image at the fiducial points. They can be used either independently or jointly. The architecture developed is based on a two-layer perceptron. The recognition performance with different types of features has been compared, which shows that Gabor wavelet coefficients are much more powerful than geometric positions. Furthermore, since the first layer of the perceptron actually performs a nonlinear reduction of the dimensionality of the feature space, they have also studied the desired number of hidden units, i.e., the appropriate dimension to represent a facial expression in order to achieve a good recognition rate. It turns out that five to seven hidden units are probably enough to represent the space of feature expressions.
1727845
Estimating the Fundamental Matrix by Transforming Image Points in Projective Space
This paper proposes a novel technique for estimating the fundamental matrix by transforming the image points in projective space. We therefore only need to perform nonlinear optimization with one parameterization of the fundamental matrix, rather than considering 36 distinct parameterizations as in previous work. We also show how to preserve the characteristics of the data noise model from the original image space.
383050
A Domain Decomposition Method for Fast Manifold Learning
We propose a fast manifold learning algorithm based on the methodology of domain decomposition. Starting with the set of sample points partitioned into two subdomains, we develop the solution of the interface problem that can glue the embeddings on the two subdomains into an embedding on the whole domain. We provide a detailed analysis to assess the errors produced by the gluing process using matrix perturbation theory. Numerical examples are given to illustrate the efficiency and effectiveness of the proposed methods.
43618975
The relation of matching with inverse degree of a graph
In this paper, we give out a counterexample of the Graffiti's conjecture (583), and get the best bounds of I(T)+@a^'(T), where T denotes a tree, I(T) denotes the inverse degree of T and @a^'(T) matching of T.