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See detailNumber and relative size of thenar motor units in ALS patients: application of the adapted multiple point stimulation method.
Wang, François-Charles ULg; Delwaide, Paul ULg

in Electroencephalography and Clinical Neurophysiology (1998), 109(1), 36-43

In the present study, the adapted multiple point stimulation (AMPS) method was first applied to median innervated thenar muscles in 22 amyotrophic lateral sclerosis (ALS) patients who did not received any ... [more ▼]

In the present study, the adapted multiple point stimulation (AMPS) method was first applied to median innervated thenar muscles in 22 amyotrophic lateral sclerosis (ALS) patients who did not received any treatment. In all patients, a motor unit number estimate (MUNE) and an average surface-recorded motor unit action potential (S-MUAP) size have been derived even if the denervation was severe; and the results were reproducible. The thenar MUNE was less than the normal lower limit for age in 17 patients, and the mean MUNE (67.1 +/- 90.6) was significantly different from that estimated in control subjects (263.3 +/- 116.8). The mean S-MUAP size in the 22 ALS patients was 352.9 +/- 328.4 microV x ms versus 94.1 +/- 30.3 microV x ms in healthy volunteers. A control AMPS was achieved in 8 patients after 2 and 6 months of a glutamate-release antagonist (riluzole) treatment. The mean loss of motor units, based on control thenar MUNEs realized after 6 months of treatment, was 53%. In conclusion, we propose AMPS as a manageable, reproducible and non-invasive procedure which permits one to quantify peripheral denervation and to appreciate the effectiveness of collateral reinnervation in ALS patients. [less ▲]

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See detailNumber of iterations when comparing MLEM/OSEM with FBP
Seret, Alain ULg

in Journal of Nuclear Medicine : Official Publication, Society of Nuclear Medicine (2004), 45(12), 2125-2125

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See detailThe number of structures compatible with any correlation function
Gommes, Cédric ULg

Conference (2013, July)

A two-point correlation function provides a crucial yet an incomplete characterization of a microstructure because distinctly different microstructures may have the same correlation function. We address ... [more ▼]

A two-point correlation function provides a crucial yet an incomplete characterization of a microstructure because distinctly different microstructures may have the same correlation function. We address here the microstructural degeneracy question: What is the number of microstructures compatible with a specified correlation function? We compute this degeneracy in the framework of reconstruction methods, which enables us to map the problem to the determination of ground-state degeneracies. Since the configuration space of a reconstruction problem is a hypercube on which a Hamming distance is defined, we can calculate analytically the energy profile of any reconstruction problem, corresponding to the average energy of all microstructures at a given Hamming distance from a ground state. The steepness of the energy profile is a measure of the roughness of the energy landscape associated with the reconstruction problem, which can be used as a proxy for the ground-state degeneracy. The relationship between this roughness metric and the ground-state degeneracy is calibrated using a Monte Carlo algorithm for determining the ground-state degeneracy of a variety of microstructures (e.g., realizations of hard disks and Poisson point processes at various densities), as well as with microstructures with a known degeneracy (e.g., single disks of various sizes and a particular crystalline microstructure). We show that our results can be expressed in terms of the information content of the two-point correlation functions. From this perspective, the a priori condition for a reconstruction to be accurate is that the information content, expressed in bits, should be comparable to the number of pixels in the unknown microstructure. We provide a formula to calculate the information content of any two-point correlation function, which makes our results directly applicable by other researchers in the field. [less ▲]

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See detailThe number of structures compatible with any given correlation function
Gommes, Cédric ULg

Scientific conference (2012)

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See detailThe Number of Structures Compatible with any Specified Correlation Function
Gommes, Cédric ULg

Conference (2015, September)

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See detailThe number of subsets required for OSEM reconstruction in nuclear cardiology
Seret, Alain ULg

in European Journal of Nuclear Medicine and Molecular Imaging (2006), 33(2), 231-231

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See detailNumber-Set Representations for Infinite-State Verification
Boigelot, Bernard ULg

in Proceedings of VISSAS 2005 (2006)

In order to compute the reachability set of infinite-state models, one needs a technique for exploring infinite sequences of transitions in finite time, as well as a symbolic representation for the finite ... [more ▼]

In order to compute the reachability set of infinite-state models, one needs a technique for exploring infinite sequences of transitions in finite time, as well as a symbolic representation for the finite and infinite sets of configurations that are to be handled. The representation problem can be solved by automata-based methods, which consist in representing a set by a finite-state machine recognizing its elements, suitably encoded as words over a finite alphabet. Automata-based set representations have many advantages: They are expressive, easy to manipulate, and admit a canonical form. In this survey, we describe two automata-based structures that have been developed for representing sets of numbers (or, more generally, of vectors): The Number Decision Diagram (NDD) for integer values, and the Real Vector Automaton (RVA) for real numbers. We discuss the expressiveness of these structures, present some construction algorithms, and give a brief introduction to some related acceleration techniques. [less ▲]

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See detailA numeration point of view on the HD0L periodicity problem
Charlier, Emilie ULg

Scientific conference (2011, January)

A HD0L system is a 5-tuple G = (∆, Γ, f, g, w) where • ∆ and Γ are alphabet; • f : ∆^∗ → ∆^∗ is a morphism; • g : ∆^∗ → Γ^∗ is a morphism; • w is a finite word over ∆. If w is a prefix of f(w) and if g(f ... [more ▼]

A HD0L system is a 5-tuple G = (∆, Γ, f, g, w) where • ∆ and Γ are alphabet; • f : ∆^∗ → ∆^∗ is a morphism; • g : ∆^∗ → Γ^∗ is a morphism; • w is a finite word over ∆. If w is a prefix of f(w) and if g(f^ω(w)) is an infinite word over Γ, where f^ω(w) denotes the limit lim_{n→+∞}f^n(w), then we define the infinite word generated by G to be ω(G) = g(f^ω(w)). The question is to decide whether the infinite word ω(G) is ultimately periodic. This open problem is called the HD0L periodicity problem. It is not hard to see that we may assume that w is a letter. Furthermore, it is well known that we can assume that f is a non-erasing morphism and g is a coding. Therefore we will always consider that all these additional hypotheses hold. On the one hand, if f is uniform of length b, then ω(G) is b-automatic. In that particular case the problem is known to be decidable. Various proofs of this result have been given by several authors. On the other hand, in the general case, when f is not necessarily uniform, ω(G) is S-automatic for some abstract numeration system S. Therefore the HD0L periodicity problem is equivalent to the following problem involving numeration systems. Given an abstract numeration system S, is it decidable whether an S-recognizable set X ⊆ N is ultimately periodic? The numeration language L and the set X are given through DFAs accepting L and rep_S(X) respectively. Thanks to this numeration point of view, we can give decision procedures for large classes of numeration systems. In this talk, I will discuss some techniques used to provide such decision procedures. [less ▲]

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See detailNumeration systems on a regular language : Arithmetic operations, Recognizability and Formal power series
Rigo, Michel ULg

in Theoretical Computer Science (2001), 269

Generalizations of numeration systems in which \(\N\) is recognizable by a finite automaton are obtained by describing a lexicographically ordered infinite regular language \(L\subset \Sigma^*\). For ... [more ▼]

Generalizations of numeration systems in which \(\N\) is recognizable by a finite automaton are obtained by describing a lexicographically ordered infinite regular language \(L\subset \Sigma^*\). For these systems, we obtain a characterization of recognizable sets of integers in terms of $\N$-rational formal series. After a study of the polynomial regular languages, we show that, if the complexity of \(L\) is \(\Theta (n^l)\) (resp. if \(L\) is the complement of a polynomial language), then multiplication by \(\lambda\in \N\) preserves recognizability only if \(\lambda=\beta^{l+1}\) (resp. if \(\lambda\neq (\#\Sigma)^\beta\)) for some \(\beta\in \N\). Finally, we obtain sufficient conditions for the notions of recognizability for abstract systems and some positional number systems to be equivalent. [less ▲]

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See detailNumeration systems: a link between number theory and formal language theory
Rigo, Michel ULg

Scientific conference (2012, November 28)

In this talk, we survey facts mostly emerging from the seminal results of Alan Cobham obtained in the late sixties and early seventies about sets of integers whose base k expansions are recognized by some ... [more ▼]

In this talk, we survey facts mostly emerging from the seminal results of Alan Cobham obtained in the late sixties and early seventies about sets of integers whose base k expansions are recognized by some finite automaton. We do not expect any background from the audience, so we will present the basic definitions and many examples. We will not attempt to be exhaustive but try instead to present some actual research directions about numeration systems, recognizable sets of integers and automatic sequences. If there is enough time, we will briefly sketch some results about transcendence related to the representation of real numbers. [less ▲]

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See detailNumeration Systems: a Link between Number Theory and Formal Language Theory
Rigo, Michel ULg

in Lecture Notes in Computer Science (2010), 6224

We survey facts mostly emerging from the seminal results of Alan Cobham obtained in the late sixties and early seventies. We do not attempt to be exhaustive but try instead to give some personal ... [more ▼]

We survey facts mostly emerging from the seminal results of Alan Cobham obtained in the late sixties and early seventies. We do not attempt to be exhaustive but try instead to give some personal interpretations and some research directions. We discuss the notion of numeration systems, recognizable sets of integers and automatic sequences. We brie y sketch some results about transcendence related to the representation of real numbers. We conclude with some applications to combinatorial game theory and veri cation of in nite-state systems and present a list of open problems. [less ▲]

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See detailNumerations systems on a regular language
Lecomte, Pierre ULg; Rigo, Michel ULg

in Theory of Computing Systems (2001), 34

Generalizations of positional number systems in which N is recognizable by finite automata are obtained by describing an arbitrary infinite regular language according to the lexicographic ordering. For ... [more ▼]

Generalizations of positional number systems in which N is recognizable by finite automata are obtained by describing an arbitrary infinite regular language according to the lexicographic ordering. For these systems of numeration, we show that ultimately periodic sets are recognizable. We also study translation and multiplication by constants as well as the order-dependence of the recognizability. [less ▲]

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See detailNumercial tools for the design of adhesively bonded composite assemblies
Laschet, Gotfriedt; Duysinx, Pierre ULg

in Actes des 8ièmes Journées Nationales sur les Matériaux Composites (JNC8) (1992, November)

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See detailNumerical - experimental interaction in hydrodynamics: an integrated approach for the optimal management of hydraulic structures and hydrographic basins
Pirotton, Michel ULg; Lejeune, André ULg; Archambeau, Pierre ULg et al

in Lu; Lamas; Li (Eds.) et al Computational Methods in Engineering and Science (2003)

The present paper presents studies and tools devoted to the reduction of uncertain-ties in the scientific knowledge of various unsteady flows, including solid transport effects, in the perspective of ... [more ▼]

The present paper presents studies and tools devoted to the reduction of uncertain-ties in the scientific knowledge of various unsteady flows, including solid transport effects, in the perspective of applications such as restoration, rehabilitation and enhancement of riverbeds, rivers and waterways. This global approach will be tested and fitted in a dynamic and integrated experimental model of reference flows in the laboratory. The relevance of using of physical experimental scale models will be highlighted for the identification of constitutive laws used in numerical modelling. Practical applications prove that the integration of powerful hydrodynamic software for water management is realistic and will lead to compute transient flooding, sedimentation and erosion events in natural compound channels, as well as to design and simulate the behaviour of hydraulic regulation works or locks. It will also help in working out new projects or reconstructions of hydraulic infrastructures, as well as ecological rehabilitations. Even if the sole quantitative plan will be taken into account, this opti-misation project will also lead to highlight favourable solutions, from a qualitative point of view. [less ▲]

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See detailNumerical analysis of coupled mechanical and hydraulic effects induced by a blood pressure meter
Paulus, Raphaël ULg; Dewals, Benjamin ULg; Erpicum, Sébastien ULg et al

in Proceedings of the 4th International Conference on Advanced Computational Methods in Engineering (2008)

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See detailNumerical analysis of partially fire protected composite slabs
Zaharia, Raul; Vulcu, Christian; Vassart, Olivier et al

in Steel and Composite Structures (2013), 14(1), 21-39

The paper presents a numerical investigation, done with the computer program SAFIR, in order to obtain simpler finite element models for representing the behaviour of the partially protected composite ... [more ▼]

The paper presents a numerical investigation, done with the computer program SAFIR, in order to obtain simpler finite element models for representing the behaviour of the partially protected composite steel concrete slabs in fire situation, considering the membrane action. Appropriate understanding and modelling of the particular behaviour of composite slabs allows a safe approach, but also substantial savings on the thermal insulation that has to be applied on the underlying steel structure. The influence of some critical parameters on the behaviour and fire resistance of composite slabs such as the amount of reinforcing steel, the thickness of the slab and the edge conditions is also highlighted. The numerical models are calibrated using the results of three full scale fire tests on composite slabs that have been performed in recent years. [less ▲]

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