In this article, we initiate a systematic study of graph resilience. The (local) resilience of a graph G with respect to a property P measures how much one has to change G (locally) to destroy P . Estimating the resilience leads to many new and challenging problems. Here we focus on random and pseudorandom graphs and prove several sharp results. © 2008 Wiley Periodicals, Inc. Random Struct. Alg...

Representations One aspect of frontal cortical function that has been given less attention than it is due, both in this review and in the literature in general, is the biological basis of the generation and manipulation of abstract frontal representations. Response properties of some PFC cells have been shown to correspond with abstract rules (Wallis et al, 2001), and models such as those of No...

. . . . . . . . . . .

New classes of quadratic time-frequency representations (QTFRs), such as the affine, hyperbolic, and power classes, are interesting alternatives to the conventional shift-covariant class (Cohen's class). This paper studies new QTFR classes that retain the inner structure of Cohen's class. These classes are based on a pair of "conjugate" unitary operators and satisfy covariance and marginal prop...

The number of objects that can be maintained in visual working memory without interference is limited. We present simulations of a model of visual working memory in ventral prefrontal cortex that has this constraint as well. One layer in ventral PFC represents all objects in memory. These representations are used to bind the features of the objects. If there are too many objects, their represen...

Let L be chosen uniformly at random from among the latin squares of order n ≥ 4 and let r, s be arbitrary distinct rows of L. We study the distribution of σr,s, the permutation of the symbols of L which maps r to s. We show that for any constant c > 0, the following events hold with probability 1− o(1) as n → ∞: (i) σr,s has more than (log n)1−c cycles, (ii) σr,s has fewer than 9√n cycles, (iii...

The number of objects that can be maintained in visual working memory without interference is limited. We present simulations of a model of visual working memory in ventral prefrontal cortex that has this constraint as well. One layer in ventral PFC constitutes a ’blackboard’ representation of all objects in memory. These representations are used to bind the features (shape, color, location) of...

In most current feature modelling systems, blends are modelled as a kind of features too. These systems use a boundary representation (Brep) to describe the shape of a product. It is shown that the practice of basing specification of blends on conventional Breps is ineffective. A solution to this problem is introduced in which blends are described at a higher level. Blends are defined in a feat...

In traditional text classification, a classifier is built using labeled training documents of every class. This paper studies a different problem. Given a set P of documents of a particular class (called positive class) and a set U of unlabeled documents that contains documents from class P and also other types of documents (called negative class documents), we want to build a classifier to cla...