Michel Habib

A simple paradigm for graph recognition: application to cographs and distance hereditary graphs

An easy way for graph recognition algorithms is to use a two-step process: first, compute a characteristic feature as if the graph belongs to that class; second, check whether the computed characteristic feature as if the graph belongs to that class; second, check whether the computed separating them may yield new and much more easily understood algorithms. In this paper we apply that paradigm to the cograph and distance hereditary graph recognition problems.

Behavioural and event-related potentials evidence for pitch discrimination deficits in dyslexic children : Improvement after intensive phonic intervention

Although it is commonly accepted that dyslexic children have auditory phonological deficits, the precise nature of these deficits remains unclear. This study examines potential pitch processing deficit in dyslexic children, and recovery after specific training, by measuring event-related brain potentials (ERPs) and behavioural responses to pitch manipulations within natural speech. In two experimental sessions, separated by 6 weeks of training, 10 dyslexic children, aged 9-12, were compared to reading age-matched controls, using sentences from childrens books. The pitch of the sentences final words was parametrically manipulated (either congruous, weakly or strongly incongruous). While dyslexics followed a training focused on phonological awareness and grapheme-to-phoneme conversion, controls followed a non-auditory training. Before training, controls outperformed dyslexic children in the detection of the strong pitch incongruity. Moreover, while strong pitch incongruities were associated with increased late positivity (P300 component) in controls, no such pattern was found in dyslexics. Most importantly, pitch discrimination performance was significantly improved, and the amplitude of the late positivity to the strong pitch incongruity enhanced, for dyslexics after a relatively brief period of training, so that their pattern of response more closely resemble those of controls.

A Simple Linear-Time Modular Decomposition Algorithm for Graphs, Using Order Extension

The first polynomial time algorithm ((mathcal{O}(n^4))) for modular decomposition appeared in 1972 [8] and since then there have been incremental improvements, eventually resulting in linear-time algorithms [22,7,23,9]. Although having optimal time complexity these algorithms are quite complicated and difficult to implement. In this paper we present an easily implementable linear-time algorithm for modular decomposition. This algorithm uses the notion of factorizing permutation and a new data-structure, the Ordered Chain Partitions.

Visual hypoemotionality and prosopagnosia associated with right temporal lobe isolation

Emotional hyporeactivity to visual stimuli (so-called visual hypoemotionality) was observed in a 71-yr-old woman following a cerebral infarction in the territory of the posterior cerebral arteries. Other visual disturbances included severe prosopagnosia, dense left hemianopia and mild left hemineglect. There was neither object agnosia nor any involvement of language, memory or intellectual functions. Hypoemotionality was found only for visual stimuli, since auditory and tactile modalities were totally spared, suggesting a visual-limbic disconnection mechanism. From CT data, and referring to previous evidence suggesting a right-hemisphere prevalence for emotional functions, it is postulated that the right occipital lesion, leading to a total right temporal lobe isolation, was mainly responsible for the patients emotional disturbances.

Polynomial Time Recognition of Clique-Width ≤ 3 Graphs

The Clique-width of a graph is an invariant which measures the complexity of the graph structures. A graph of bounded tree-width is also of bounded Clique-width (but not the converse). For graphs G of bounded , given the bounded width decomposition of G, every optimization, enumeration or evaluation problem that can be defined by a Monadic Second Order Logic formula using quantifiers on vertices but not on edges, can be solved in polynomial time.

An electrophysiological study of dyslexic and control adults in a sentence reading task.

Event-related potentials and cued-recall performance were used to compare dyslexic and control adult subjects. Sentences that ended either congruously or incongruously were presented visually, one word at a time, at fast (stimulus-onset-asynchrony (SOA)=100 ms) or slow (SOA=700 ms) rates of presentation. Results revealed (1) a large effect of presentation rate that started with the N1-P2 components and lasted for the entire recording period, (2) larger N400 components for dyslexic than control subjects, at slow presentation rates, to both congruous and incongruous endings and (3) a large ERPs difference related to memory (Dm effect) that did not differentiate controls from dyslexics but was larger at slow than at fast rates of presentation. These findings indicate that the reading impairment observed in the present group of adult dyslexics is more likely to result from difficulties integrating the meaning of words within a sentence context than from pure sensory processing deficits.

Encoding of Multiple Inheritance Hierarchies and Partial Orders

Efficient implementation of type inclusion is an important feature of object oriented programming languages with multiple inheritance. The idea is to associate to each type a subset of a set S={1,...,k} such that type inclusion coincides with subset inclusion. Such an embedding of types into 2S (the lattice of all subsets of S) is called a bit‐vector encoding of the type hierarchy. In this paper, we show that most known bit‐vector encoding methods can be inserted on a general theoretical framework using graph coloration, namely the notion of a simple encoding. We use the word simple because all these methods are heuristics for the general bit‐vector encoding problem, known as the 2‐dimension problem. First we provide a correct algorithm for partial orders based on simple encoding, improving the algorithm of Krall, Vitek, and Horspool (1997). Second we show that finding an optimal simple encoding is an NP‐hard problem. We end with a discussion on some practical issues.

Revisiting t. uno and m. yagiura's algorithm

In 2000, T. Uno and M. Yagiura published an algorithm that computes all the K common intervals of two given permutations of length n in

Deficit in the preattentive processing of syllabic duration and VOT in children with dyslexia

mathcal{O}(n+ K)

Music and Dyslexia: A New Musical Training Method to Improve Reading and Related Disorders

time. Our paper first presents a decomposition approach to obtain a compact encoding for common intervals of d permutations. Then, we revisit T. Uno and M. Yagiuras algorithm to yield a linear time algorithm for finding this encoding. Besides, we adapt the algorithm to obtain a linear time modular decomposition of an undirected graph, and thereby propose a formal invariant-based proof for all these algorithms.