In this dissertation we employ stack and queue layouts of graphs to explore the relative power of stacks and queues. Stack layout and queue layouts of graphs can be examined from several points of view. A stack or a queue layout of a graph can be thought of as an embedding of the graph in a plane satisfying certain constraints, or as a graph linearization that optimizes certain cost measures, or as a scheme to process the edges of the graph using the fewest number of stacks or queues. All three points of view permeate this research, though the third point of view dominates. Specific problems in stack and queue layouts of graphs have their origin in the areas of VLSI, fault-tolerant computing, scheduling parallel processes, sorting with a network of stacks and queues, and matrix computations. We first present two tools that are useful in the combinatorial and algorithmic analysis of stack and queue layouts as well as in determining bounds on the stacknumber and the queuenumber for a variety of graphs. The first tool is a formulation of a queue layout of a graph as a covering of its adjacent matrix with staircases. Not only does this formulation serve as a tool for analyzing stack and queue layouts, it also leads to efficient algorithms for several problems related to sequences, graph theory, and computational geometry. The connection between queue layouts and matrix covers also forms the basis of a new scheme for performing matrix computations on a data driven network. Our analysis reveals that this scheme uses less hardware and is faster than existing schemes. The second tool is obtained by considering separated and mingled layouts of graphs. This tool allows us to obtain lower bounds on the stacknumber and the queuenumber of a graph by partitioning the graph into subgraphs and simply concentrating on the interaction of the subgraphs. These tools are used to obtain results in three areas. The first area is stack and queue layouts of directed acyclic graphs (dags). This area is motivated by problems of scheduling parallel processes. We establish the stacknumber and the queuenumber of classes of dags such as trees, unicylic graphs, outerplanar graphs, and planar graphs. We then present linear time algorithms to recognize 1-stack dags and leveled-planar dags. In contrast, we show that the problem of recognizing 9-stack dags and the problem of recognizing 4-queue dags are both NP-complete. The second area is stack and queue layouts of partially ordered sets (posets). We establish upper bounds on the queuenumber of a poset in terms of other measures such as length, width, and jumpnumber. We also present lower bounds on the stacknumber and on the queuenumber of certain classes of posets. We conclude by showing that the problem of recognizing a 4-queue poset is NP-complete. The third area is queue layouts of planar graphs. While it has been shown that the stacknumber of the family of planar graphs is 4, the queuenumber of planar graphs is unknown. We conjecture that a family of planar graphs—the stellated triangles—has unbounded queuenumber; using separated and mingled layouts, we demonstrate significant progress towards that result. / Ph. D.

Yes / The Self-Regulation Model (SRM) identifies that the beliefs people hold about an illness can influence their responses to that illness. Although there are generic measures of illness representations, there is a need for a brief tailored measure to use with people with dementia. The aim of this study was to develop and validate a brief measure called the Representations and Adjustment to Dementia Index (RADIX). The RADIX contains questions on the SRM elements: Identity, Cause, Timeline, Control, and Consequences. The RADIX validation was conducted with a sample of 385 community-dwelling people with mild to moderate dementia who were taking part in the IDEAL cohort study. Test-retest reliability was conducted over a 4-week period with a separate sample of 20 people with dementia. The validation process resulted in a reduction in the number of items in the Timeline, Control, and Consequences items. The resulting RADIX demonstrated good acceptability, internal reliability, and test-retest reliability. All the RADIX items had low missing data, indicating good acceptability. The factor analysis confirmed that the Consequences items formed two subscales (practical and emotional consequences) that had Cronbach's α of 8 and 0.91 respectively. Test-retest reliability indicated that the Identity, Timeline, and Control items had moderate reliability and the practical and emotional consequences scales had good reliability. The RADIX demonstrates acceptable psychometric properties, proves to be a useful measure for exploring people's beliefs about dementia, and could aid the provision of tailored information and support to people with dementia.

Ce travail se situe dans le champ des Sciences de l’Education. Il s’intéresse au processus de professionnalisation des étudiants sages-femmes grâce à l’étude d’un système de représentations de trois objets professionnels que sont la profession de sage-femme, la profession de médecin et l’accompagnement.Nous avons réalisé une étude longitudinale de 3 ans auprès des étudiants sages-femmes de France à l’aide d’un questionnaire en ligne. Au final, les réponses de 429 sujets ont pu être appariées. Cette étude sur trois ans a permis de couvrir les différents temps de l’entrée en formation aux deux premières années professionnelles.Nous avons pu observer la stabilité des noyaux centraux des représentations de la profession de sage-femme et de la profession de médecin. Nous notons toutefois des variations significatives dans le contenu lexical des représentations des trois objets. L’étude de ce système de représentations permet de rendre saillant les liens qui se font et se défont entre chacun de ces trois objets. L’évolution de ce système est interprétée comme une conséquence du processus de professionnalisation.L’étude d’un système de représentation nous a permis de mettre en avant une dimension praxéologique pour notre profession de sage-femme enseignante (organisation de séances d’analyse des pratiques, de tables rondes, de jeux de rôle, de groupe de parole…). D’un point de vue théorique, cette étude permet de faire l’hypothèse que l’évolution dynamique des représentations présenterait une stabilité du noyau central mais des variations dans la ou les signification(s) attribuée(s) aux objets. / This work is in the field of Science Education. He is interested in the process of professionalisation of midwifery students through the study of a system of representations of three professional objects are the profession of midwife, the medical profession and accompaniment. We conducted a longitudinal study of 3 years with midwifery students from France with an online questionnaire. In the end, the answers of 429 subjects have been matched. This three-year study has covered different time in training entry to the first two professional years. We observed the stability of central nuclei of representations of the profession of midwifery and the medical profession. We note, however, significant variations in the lexical content of the representations of the three objects. The study of this representation system helps make highlight the links that form and dissolve between each of these three items. The evolution of this system is interpreted as a consequence of the professionalization process. The study of a system of representation allowed us to put forward a praxeological dimension to our teaching midwifery profession (organization of practical analysis sessions, panel discussions, role plays, group speech…). From a theoretical point of view, this study allows for the assumption that the dynamic evolution of representations present a stable core but variations in or meaning(s) rating(s) to objects.

Title: Algebraic, Structural and Complexity Aspects of Geometric Representations of Graphs Author: Peter Zeman Department: Computer Science Institute Supervisor: RNDr. Pavel Klavík Supervisor's e-mail: klavik@iuuk.mff.cuni.cz Keywords: automorphism groups, interval graphs, circle graphs, comparability graphs, H-graphs, recognition, dominating set, graph isomorphism, maximum clique, coloring Abstract: We study symmetries of geometrically represented graphs. We describe a tech- nique to determine the automorphism group of a geometrically represented graph, by understanding the structure of the induced action on all geometric representations. We prove that interval graphs have the same automorphism groups as trees, and for a given interval graph, we construct a tree with the same automorphism group which answers a question of Hanlon [Trans. Amer. Math. Soc 272(2), 1982]. For permutation and circle graphs, we give an inductive characterization by semidirect and wreath prod- ucts. We also prove that every abstract group can be realized by the automorphism group of a comparability graph/poset of the dimension at most four. We also study H-graphs, introduced by Biró, Hujter, and Tuza in 1992. Those are intersection graphs of connected subgraphs of a subdivision of a graph H. This thesis is the first comprehensive...

Planifier, exécuter un mouvement fait appel à des représentations mentales de l'action. Ces dernières ont été formalisées par les sciences computationnelles sous le terme de modèles internes du contrôle moteur. Outre l'environnement, les informations concernant la posture, les dimensions de l'effecteur sont également cruciales et doivent être mises à jour fréquemment. Etonnamment, les modèles actuels de l‘action n'attribuent pas aux représentations du corps un rôle majeur. La mise à jour de ces représentations de l'action et du corps doit intervenir dès l'enfance, néanmoins leur développement reste méconnu. En premier lieu, je me suis attachée au développement des représentations de l'action chez les enfants de 5 à 10 ans, au développement typique d'une part et lors de Troubles des Acquisitions et de la Coordination (TAC) d'autre part. A travers la cinématique, j'ai cherché à comprendre comment les enfants développent leur capacité à anticiper et adapter leurs mouvements. Dans un deuxième temps, l'utilisation d'un outil qui allonge fonctionnellement le bras m'a permis d'examiner les inputs sensoriels (vision, proprioception) nécessaires à la plasticité des représentations du corps chez l'adulte. Enfin, j'ai interrogé ces mécanismes de plasticité des représentations de l'effecteur au cours de la croissance de l'individu alors que les dimensions corporelles changent progressivement. Dans ce but, j'ai étudié la plasticité induite par l'outil chez des enfants et adolescents au développement typique. Finalement, je discuterai des liens entre représentations du corps et contrôle moteur, deux notions indispensables à la cognition motrice / To prepare and perform movements efficiently, accurate action representations are necessary, formalized by computational science as “internal models”. Actions representations do not require exclusively the representation of object properties, information about the body and particularly the effector such as its posture and dimension are also crucial. Thus, effector representations need to be updated to account for postural changes, yet, they do not play a prominent role in the actual models of motor control. In addition, updates settings of both action and body representation are presumably established ontogenetically, but little is known on their developmental path. First, I investigated the maturation of action representation in children from 5 to 10 years of age, as well as the potential differences in children with Developmental Coordination Disorder (DCD). Through kinematics analyses, I sought to understand how children develop their ability to control their movements. Second, using a tool functionally extending arm length, I questioned the sensory inputs for body representation plasticity in adults, such as proprioception and vision. Third, I probed rapid body representations plasticity during the slowly changing dimensions of the body during growth. To this aim I investigated in typically developing children and adolescents tool-induced plasticity of the upper-limb representation. Finally, I discuss the relationship between body representations and motor control in adults and children, as despite being both related they have often times walked parallel ways

Ce travail de recherche met à l'épreuve l'hypothèse de la mystification entendue comme stratégie communicationnelle manifestée par des tendances spécifiques où la dialectique entre obscurcissant et révélant jouent un rôle fondamental dans la production des formes symboliques. Dans ce cadre, le concept de mystification comme paradigme de sens est en rapport avec un modèle de communication qui se manifeste partout où s'impose la médiation entre le sacré et le profane ainsi que le maintien de l'ordre symbolique. Les médias non seulement qu'ils utilisent la mystification comme une stratégie, mais ils fonctionnent dans le paradigme de la mystification notamment quand il s'agit d'intervenir pour préserver l'ordre social par une production des formes symboliques spécifiques. Pour identifier les thèmes récurrents qui apparaissent dans les représentations médiatiques internationaux, des thèmes qui fournissent des indications sur les tendances qui sont spécifiques pour le paradigme de la mystification, l'analyse empirique aborde la production et la transmission des formes symboliques concernant les représentations médiatiques dans le contexte de l'attaque terroriste contre journal Charlie Hebdo du 7 Janvier 2015. / The present research work advances the following hypothesis – mystification is acommunicational strategy manifested through specific trends where the dialectic between obscuring and revealing plays a fundamental role in the production of the symbolic forms. It is therefore proposed that the concept of the mystification paradigm requires a communication model that manifests itself wherever the mediation between sacred and profane and maintaining the symbolic order are required. Media not only use this model as a strategy but function in the mystification paradigm especially when it is supposed to intervene for preserving the social order through a specific production of symbolic forms. To identify recurring themes that arise in the media representations generated by the international press, themes that provides indicators of particular trends that are specific in the mystification paradigm, an empirical analysis of this production and transmision of the symbolic forms has been employed in the special context of the terrorist attack against the journal Charlie Hebdo on January 7, 2015.

Depuis les années 70, l’introduction de l’informatique et d’Internet dans la formation des enseignants et dans les programmes du Primaire n’a eu de cesse de générer des questionnements, des craintes et des espoirs. Parallèlement, le recrutement et la formation des enseignants du Primaire n’ont aussi cessé d’être débattus.Dans le cadre de cette recherche, nous avons voulu comprendre la professionnalisation du métier d’enseignant en comparant les représentations de l’informatique et du métier d’enseignant au Primaire d’un groupe en formation (futurs professeurs des écoles, PE) et d’un groupe professionnel (enseignants en poste). Nous avons aussi opérationnalisé l’hypothèse de polyphasie cognitive (Moscovici, 1961) en étudiant, pour un même groupe, la représentation de l’informatique dans le contexte de la vie privée et dans le contexte de la vie professionnelle. Les résultats obtenus par questionnaire montrent, tant au niveau structural qu’au niveau du champ structuré, des différences entre les réponses de 175 futurs PE et celles de 245 enseignants sur l’informatique à l’école. Dans le cadre de leur vie privée, il y a beaucoup moins de différences notables entre leurs réponses. Concernant la représentation du métier, les quelques différences repérées sont expliquées à travers l’expérience et le professionnalisme.Cette recherche participe donc à la compréhension des processus de professionnalisation sous la composante représentationnelle. Elle confirme, par ailleurs, la nécessité de préciser le contexte d’évocation dans des recherches sur les représentations sociales. / Since the 70s, introduction of ICT and Internet in the teachers if training and on curriculum of Primary school has continued to generate questions, fears and hope. In parallel, recruitment and training of Primary school teachers have also been permanently debated.Within the context of this research, we wanted to understand professionalization of teacher profession by comparing ICT representations and teacher profession representations in a training group (future teachers) and in a professional one (teachers in post). We also operationalized the hypothesis of cognitive polyphasia (Moscovici, 1961) by studying, for same group, ICT’ representation in the context of private life and in the context of professional life.The questionnaire results show, both at structural level and at structured field, differences between answers of 175 future teachers and of 245 teachers on ICT at school. As part of their private life, there are far fewer strong differences between their answers. Concerning the representation of profession, some spotted differences are explained through experience and professionalism. This research participates therefore in the understanding of professionalization processes under representational component. It confirms, moreover, the necessity to specify context of evocation in researches on social representations.

The purpose of this thesis was to present the technique of double coset enumeration and apply it to construct finite homomorphic images of infinite semidirect products. Several important homomorphic images include the classical groups, the Projective Special Linear group and the Derived Chevalley group were constructed.

This thesis constructs several groups entirely by hand via their symmetric presentations. In particular, the technique of double coset enumeration is used to manually construct J₃ : 2, the automorphism group of the Janko group J₃, and represent every element of the group as a permutation of PSL₂ (16) : 4, on 120 letters, followed by a word of length at most 3.

During the so-called ‘migration crisis’ of 2015, 51,338 Syrians applied for asylum in Sweden. First, Swedish politicians called for Swedes to ‘open their hearts’, public support was strong, and media coverage was full of possibilities and humanizing images. As the crisis developed, Sweden’s generous asylum legislation switched to the EU minimum, the political climate toughened and media’s positive frames soon shifted to discussing negative consequences. This degree project focuses on those least visible in the media’s representation of the migration crisis – refugee women. By using Chouliaraki and Zaborowski’s (2017) model ‘voice by narrative’, it answers the research question; How are refugee women from Syria represented in national and local Swedish newspapers?, as well as the following sub-questions: What news frames are used in texts where Syrian women are featured? In what ways are refugee women given visibility and space to speak? What types of representations, wording, and stereotypes are used? What differences can be found between 2015 and 2020, national and local newspapers? The project examines news frames, gendered representations, typical stereotypes, visibility, and space given to Syrian women in Swedish newspapers. It does so by content analysis of newspaper articles from three newspapers published in 2015 and 2020. The project uses theories of othering, intersectionality, and post-colonial power structures as well as literature on representations in European media during the migration crisis to understand representations, voice, and news frames in Swedish newspapers. The results indicated that refugee women are often silenced and spoken of instead of given space to speak. The most commonly used news frames among the analyzed texts were negative geopolitical and women were often decontextualized. Victimization and normalization were the most commonly used stereotypes assigned to refugee women. The majority of representations of refugee women were collective and the women were in many ways othered. Refugee women are othered, decontextualized, silenced, and collectivized, which will have its consequences as they are methods that limit refugee women’s status and position in society – maintaining their position as ‘others’ in Swedish society.