Topology control and small-worlds in hybrid wireless networks

Doctoral thesis (2007)

Questions de typologie textuelle

Presentation (2007, December 04)

The Arabidopsis circadian clock incorporates a cADPR-based feedback loop

in SCIENCE (2007), 318(5857), 1789-1792

Transcriptional feedback loops are a feature of circadian clocks in both animals and plants. We show that the plant circadian clock also incorporates the cytosolic signaling molecule cyclic adenosine ... [more ▼]

Transcriptional feedback loops are a feature of circadian clocks in both animals and plants. We show that the plant circadian clock also incorporates the cytosolic signaling molecule cyclic adenosine diphosphate ribose (cADPR). cADPR modulates the circadian oscillator’s transcriptional feedback loops and drives circadian oscillations of Ca2+ release. The effects of antagonists of cADPR signaling, manipulation of cADPR synthesis, and mathematical simulation of the interaction of cADPR with the circadian clock indicate that cADPR forms a feedback loop within the plant circadian clock. [less ▲]

CONTEXTE DE TRAVAIL ET ANALYSE DE L’EXPÉRIENCE. Conception d’une méthode d’aide à l’analyse de l’expérience en contexte.

Doctoral thesis (2007)

Insertion et réinsertion dans l’emploi, employabilité, parcours professionnels sont devenus ces dernières années des thèmes prépondérants dans le domaine du travail. Les difficultés connues sur le marché ... [more ▼]

Insertion et réinsertion dans l’emploi, employabilité, parcours professionnels sont devenus ces dernières années des thèmes prépondérants dans le domaine du travail. Les difficultés connues sur le marché du travail, l’augmentation de la précarité, les exigences en termes de polyvalence et de flexibilité, amènent à réexaminer la situation de travail et à s’interroger sur des éléments de transversalité et transférabilité entre différents emplois. Un nombre considérable d’études menées dans différents champs de la psychologie ont permis de mettre en évidence le caractère contextualisé de l’action. Toutefois, la notion de contexte de travail, largement présente dans la littérature, demeure encore largement absente des pratiques d’insertion et d’orientation professionnelle. La présente recherche défend l’idée selon laquelle l’analyse et la prise en compte des contextes de travail peut améliorer l’efficacité des démarches d’aide à la construction de parcours et multiplier les hypothèses d’évolution professionnelle. La démarche qui a contribué à tester cette hypothèse s’est déroulée en trois étapes : la mise au point d’une typologie d’éléments caractéristiques du contexte des emplois-métiers de trois secteurs d’activité différents ; la conception d’une méthode d’analyse de l’expérience intégrant ces éléments de contexte ; la mise en œuvre de la méthode et le suivi de 137 travailleurs et de 22 conseillers emploi et orientation. Les résultats obtenus confirment l’intérêt qu’il y a à prendre en compte l’expérience du contexte pour la construction de parcours professionnels. Cette recherche permet aussi d’aborder la notion de contexte subjectif. Elle relève les différences perceptions individuelles du contexte et fournit des éléments d’explication à ce phénomène. [less ▲]

Haydn’s arrangements of Scottish folksongs

Scientific Conference (2007, November 30)

Operations on Finite Sets, Functional Composition, and Ordered Sets

Doctoral thesis (2007)

The unifying theme of this research work is functional composition. We study operations on a nonempty set A, an important particular case being that of Boolean functions when A = {0, 1}. A class of ... [more ▼]

The unifying theme of this research work is functional composition. We study operations on a nonempty set A, an important particular case being that of Boolean functions when A = {0, 1}. A class of operations is a subset of the set of all operations on A. A clone on A is a class of operations on A that contains all projection maps and is closed under functional composition. The first part of this thesis is a study of compositions of the clones of Boolean functions. The clone of all Boolean functions can be decomposed in various ways into minimal clones, and we observe that such decompositions correspond to different normal form systems: the disjunctive normal form (DNF), conjunctive normal form (CNF), Zhegalkin polynomial, dual Zhegalkin polynomial, and so-called median normal form. These normal form systems are compared in terms of efficiency, and we establish that the median normal form system provides in a certain sense more efficient representations than the other four normal form systems mentioned above. The second part of this thesis is a study of certain order relations on the set of all operations on A. For a fixed class C of operations on A, we say that f is a C-subfunction of g, if f can be obtained by composing g from inside with operations from C. We say that f and g are C-equivalent, if f and g are C-subfunctions of each other. The C-subfunction relation is a quasiorder (a reflexive and transitive relation) on the set of all operations on A if and only if the parametrizing class C is a clone. The simplest example of C-subfunction relations is obtained when C is the smallest clone I of projections on A. Forming I-subfunctions corresponds to simple manipulation of variables, namely addition and deletion of dummy variables, permutation of variables, and identification of variables. None of these operations increases the number of essential variables, and only variable identification may decrease this number. We study more carefully the effect of variable identification on the number of essential variables of operations on finite base sets. We then study certain order-theoretical properties of various C-subfunction partial orders defined by larger clones C on finite base sets A. We are mostly concerned about the descending chain condition and the existence of infinite antichains, and as it turns out, these properties on the defining clone C. Homomorphisms of labeled posets (or k-posets) are applied in our analysis of subfunction relations defined by clones of monotone functions. The third part of this thesis is a study of the homomorphicity order of finite k-posets on its own right. We establish that this order is a distributive lattice, and furthermore, it is universal in the sense that every countable poset can be embedded into it. This result implies universality of the subfunction partial orders defined by clones of monotone functions on finite sets of more than two elements. In this way, we also obtain a new proof for the well-known universality of the homomorphicity order of graphs. [less ▲]

Zur praktischen Ermittlung der Verformungen von Verbundträgern und Flachdeckensystemen unter Berücksichtigung der Nachgiebigkeit der Verbundfuge

in Stahlbau (2007), Jahrgang 76(Heft 11),

Simplified method for the determination of the influence of flexibility of shear connection on deflections of composite beams and Slim floor Systems For composite beams and Slim Floor Systems normally ... [more ▼]

Simplified method for the determination of the influence of flexibility of shear connection on deflections of composite beams and Slim floor Systems For composite beams and Slim Floor Systems normally ductile shear connection like headed studs is used. The flexibility of the shear connection influences the deformation behaviour of the structure especially where partial shear connection or ribbed concrete slabs with ribs transverse to the beam are used. For slim floor systems the special geometry of the cross section leads to a significant influence of the deformation behaviour of the shear connection on the deflections. Because the exact calculation of deformations under consideration of the flexibility needs quite complicate theoretical model, for practical applications a simplified model based on a modified modular ratio method is presented. [less ▲]

Aprendizaje cooperativo en educación física

Scientific Conference (2007, November)

Auto-aprendizaje en el deporte: ¿Que estrategias utilizan hombres y mujeres?

Scientific Conference (2007, November)

Auto aprendizaje en el deporte: Que estrategias utilizan hombres y mujeres?

in Arboleda Sierra, Rodrigo (Ed.) Aprendizaje motor: elementos para una teoría de la ensenanza de las habilidades motrices (2007)