Dissertations / Theses on the topic 'Symmetrisk relation'

In our independent work, the purpose for us is to gain an increased insight into the complex collaboration that exists between educators and guardians and to gain an increased insight into the relationship between educator and student. We believe that this is not a sufficiently explored topic in the after-school center and the challenge therefore lies in finding suitable literature that relates to our independent work. In this independent work, we start from our professional experiences in two difficult-to-assess dilemmas in school and leisure activities. Christopher's dilemma text is about his empathy for "his" student, and that Christopher chooses to tell a white lie to his student's mother to protect the student in question. Fredrik's dilemma text is similar to Christopher's, but the action differs from Christopher's text. Fredrik chooses to tell the truth to “his” student's mother in the belief of being able to see things in a larger perspective and thus create better conditions for the student's schooling. In our independent work, we have used methods such as: scientific essay writing and hermeneutic approach. The theories we have chosen to use are the relationship between educator and student, the relationship between school and home and ethical perspectives. We have then linked the theory part to our individual and joint reflections. Our study deals with the asymmetric versus the symmetrical relationships that exist between adults and children and the interpretive preference that adults have. We discuss the UN Convention on the Rights of the Child and how complex it is to decide what is in the best interests of the child and who can decide it. In the theory part that deals with the relationship between school and home, we highlight the problematic collaboration that exists between educators and guardians. We also highlight the collaboration with an intercultural perspective where cultures and traditions have a great impact. In the study, we write about how we can work to achieve a better collaboration with the homes. We also shed light on the concept of practical knowledge and how it can be expressed in our professional profession. Finally, in the theory part, we deal with ethics of duty, ethics of discourse, ethics of utility and ethics of proximity. At the end of our independent work, we write about our lessons from the study and concluding thoughts about what we learned during the work. Keywords: collaboration, communication, ethics, asymmetric / symmetrical relationship, leisure center, school, trust, dialogue, relationship competence, practical knowledge.
I vårt självständiga arbete är syftet för oss att få en ökad insikt i den komplexa samverkan somfinns mellan pedagoger och vårdnadshavare samt att få en ökad insikt i relationen mellan pedagog och elev. Vi anser att detta inte är ett tillräckligt utforskat ämne inom fritidshemmet och utmaningen ligger därför i att hitta lämplig litteratur som rör vårt självständiga arbete. I detta självständiga arbete utgår vi från våra yrkeserfarenheter i två svårbedömda dilemman inom skol- och fritidsverksamheten. Christophers dilemmatext handlar om hans empati för ”sin” elev, och att Christopher väljer att dra en vit lögn för sin elevs mamma för att skydda eleven ifråga. Fredriks dilemmatext är snarlik Christophers men handlandet skiljer sig från Christophers text. Fredrik väljer att berätta sanningen för ”sin” elevs mamma i tron om att kunna se saker i ett större perspektiv och således skapa bättre förutsättningar för elevens skolgång. I vårt självständiga arbete har vi använt oss av metoder som: vetenskapligt essäskrivande och hermeneutiskt förhållningssätt. De teorier som vi valt att använda oss av är relationen mellan pedagog och elev, relationen skola och hem samt etiska perspektiv. Teoridelen har vi sedan kopplat till våra individuella och gemensamma reflektioner. Vår studie behandlar de asymmetriska kontra de symmetriska relationerna som finns mellan vuxna och barn samt det tolkningsföreträde som vuxna har. Vi diskuterar kring FN:s barnkonvention och hur komplext det är att avgöra vad som är barnets bästa och vem som kan besluta det. I teoridelen som behandlar relationen skola och hem belyser vi det problematiska samarbetet som finns mellan pedagoger och vårdnadshavare. Vi belyser även samarbetet med ett interkulturellt perspektiv där kulturer och traditioner har en stor påverkan. I studien skriver vi om hur vi kan arbeta för att nå ett bättre samarbete med hemmen. Vi belyser även begreppet praktisk kunskap och hur det kan ta sig i uttryck i vår yrkesprofession. Avslutningsvis i teoridelen behandlar vi pliktetik, diskursetik, nyttoetik och närhetsetik. I slutet av vårt självständiga arbete skriver vi om våra lärdomar från studien samt avslutande tankar kring vad vi lärt oss under arbetets gång.

Abstract A progenitor developed by Robert T. Curtis is a type of infinite groups formed by the semi-direct product of a free group m∗n and a transitive permutation group of degree n. To produce finite homomorphic images we had to add relations to the progenitor of the form 2∗n : N. In this thesis we have investigated several permutations progenitors and monomials, 2∗12 : S4, 2∗12 : S4 × 2, 2∗13 : (13 : 4), 2∗30 : ((2• : 3) : 5), 2∗13 :13,2∗13 :(13:2),2∗13 :(13:S3),53∗2 :m (13:4),7∗8 :m (32 :8),and 53∗4 :m (13 : 4). We have discovered that the permutations progenitors produced the following finite homomorphic images, we have found P GL(2, 13), U3 (4) : 2, 2 × Sz (8), PSL(2,7), PGL(2,27), PSL(2,8), PSL(3,3), 4•S4(5), PSL2(53), and 13 : PGL2(53) as homomorphic images of this progenitors. We will construct double coset enumeration for the homomorphic images, 2 × Sz (8) over (13 : 4) Suzuki twisted group, P GL(2, 13) over S4,and PSL(2,7) over S4 and Maximal subgroups of 2×PGL(2,27) over 2•(13 : 2), P SL(2, 8) over (9 : 2), and P SL(3, 3) over (13 : 3). We will also give our techniques of finding finite homomorphic images and their isomorphism images.

This study intends to research SVT’s work with dialogical and symmetrical two-way communication with their audience on the social media site Facebook. Because of SVT’s position as the government’s public broadcasting service, they inheret a certain responsibility towards the population of Sweden. With this study we aim to observe and analyze SVT’s communication on Facebook based on theories, interviews and their own policy regarding communication online. To be able to reach our goals with this study we are going to analyze the policy document as well as articles regarding social media use from SVT, interview communicators at SVT and also perform an analysis on one of SVT’s Facebook pages based on online observations. When analysing the content of the Facebook page we are using a synthesized definition of the theoretical frameworks and models regarding dialogue, two-way communication and deliberative democracy. Our results show that SVT’s own definition of dialogue differs from an academic definition of the very specific and complicated concept of dialogue. In our research we notice that SVT aims to market themselves and perform dialogue simultaneously, which becomes problematic due to the strict academic definitions of the dialogue-notion. The interaction between SVT and their stakeholders on Facebook mostly contain simple questions regarding the organisation’s broadcasting and range which does not provide the right conditions for dialogue.

Governments often fund foreign nationals to live, work and study in their countries, creating specialist programmes tasked with promoting international mobility. In this thesis I establish that much of this funding is intended to serve a public diplomacy agenda, improving international relations to the benefit of the sponsor. Expectations about how offering funding to foreigners affects international relations have come to centre on what I label the ‘symmetric public diplomacy model’, which suggests that governments intend to influence other countries’ behaviour by influencing their citizens. I tested this model using a combination of panel surveys and interviews with students who took part in these programmes. Although mobility programmes do bring many educational and personal benefits to participants, my results do not support the expectation that they endow most visiting foreigners with more helpful attitudes than they would have developed had they not taken part in the programmes. While other studies have come to different conclusions on this issue, the research design employed in this thesis is better-suited to the task than most others. Mobility programmes may bring diplomatic benefits by other means. One possibility is that the act of creating, for example, scholarships for foreign nationals sends signals to foreign governments. The histories of major British scholarship programmes suggest that they were originally created to signal goodwill or distract attention from potentially-embarrassing policies. Despite this, administrators now present these programmes as tools of public diplomacy. The symmetric public diplomacy model has been applied to these programmes long after they were initially created, and I suggest that the model may have been adopted because it is useful for attracting funding to continue and expand mobility programmes.

This thesis is concerned with the utilization of object symmety as a cue for segmentation and object recognition. In particular it investigates the problem of detecting 3D bilaterally symmetric objects from affine views. The first part of the thesis investigates the problem of detecting 3D bilateral symmetry within a scene from known point correspondences across two or more affine views. We begin by extending the notion of skewed symmetry to three dimensions, and give a definition in terms of degenerate structure that applies equally to an affine 3D structure or to point correspondences across two or more affine views. We then consider the effects of measurement errors on symmetry detection, and derive an optimal statistical test of degenerate structure, and thereby of 3D-skewed symmetry. We then move on to the problem of searching for 3D skewed symmetric sets within a larger scene. We discuss two approaches to the problem, both of which we have implemented, and we demonstrate fully automatic detection of 3D skewed symmetry on images of uncluttered scenes. We conclude the first part by investing means of verifying the presence of bilateral rather than skewed symmetry in the Euclidean space, by enforcing mutual consistency between multiple skewed symmetric sets, and by drawing on partial knowledge about the camera calibration. The second part of the thesis is concerned with the problem of obtaining feature correspondences across multiple affine views, as required for the detection of symmetry. In particular we investigate the geometric matching constraints that exist between affine views. We start by specilizing the four projective multifocal tensors to the affine case, and use these to carry the bulk of all known projective multi-view matching relations to affine views, unearthing some new relations in the process. Having done that, we address the problem of estimating the affine tensors. We provide a minimal set of constraints on the affine trifocal tensor, and search for ways of estimating the affine tensors from point and line correspondences.

Web 2.0 har möjliggjort och öppnat upp för en ny typ av mellanmänsklig kommunikation. Numera kan vem som helst starta sin egen offentliga och lättillgängliga webbplattform där digitala dialoger frodas och med det skapas attraktiva marknadsplatser för företag. Enligt forskningsluckan vi har identifierat anser vi att det saknas insikter om hur företag på bästa sätt ska arbeta med bloggare utifrån bloggarnas perspektiv. Bloggar är inte bara en attraktiv marknadsplats för företag utan också för bloggarna själva som skapar sitt personliga varumärke genom att bygga upp den digitala identitet som presenteras i bloggen. Således är syftet med vår uppsats att bidra till ökad förståelse för bloggares preferenser i relationen med företag och varumärken, samt hur de väljer varumärken att beröra i sin blogg utifrån sin digitalt konstruerade identitet. För att genomföra vår studie har vi valt en kvalitativ metod med en abduktiv ansats där vi har genomfört semistrukturerade intervjuer med sju populära bloggare i Sverige. Den teoretiska referensramen som ligger till grund för vår studie är uppdelad i tre huvudkategorier; marketing public relations, word-of-mouth/word-of-blog samt personligt varumärke, där vi berör begreppen relationer, digitala dialoger, tvåvägs-symmetrisk kommunikation, digitalidentitet och källtrovärdighet. Resultatet i vår studie visar att bloggare önskar ett professionellt bemötande i relationen med PR-utövare men en personlig relation till varumärken. PR-utövare bör erbjuda bloggarna unikhet, involvering, nyhetsvärde och arvode för att skapa fördelaktiga tvåvägs-symmetriska bloggrelationer i syfte att gynna varumärket. Således förändras synen på traditionell PR vilket snarare innefattar relationer än finansiering. I vår studie presenterar vi därför en definition och modell av begreppet Blog Public Relations (BPR) vilket är vårt huvudsakliga bidrag till den vetenskapliga diskursen. Vidare visar vår undersökning att det finns tre faktorer som påverkar bloggare till att avvika från sin digitala identitet i samarbetet med företag. Förutom att de känner en press att uppdatera bloggen, och därmed ibland har valt att skriva om vissa produkter på grund av det, påverkar ett högt arvode eller ett riktigt bra och proffsigt bemötande från PR-utövarna den kommersiella avvägningen.
Web 2.0 has enabled and opened up for a new type of interpersonal communication. Nowadays, anyone can start their own public and accessible web platform where digital dialogues flourish and thus the creation of attractive markets for companies. According to the research gap we have identified, we believe that there is a lack of understanding of how companies’ best should practice blog relationships according to the bloggers. Blogs are notonly an attractive marketplace for companies but also for the bloggers themselves since they create their own personal brand by building up their digital identities that are presented in the blog. Thus, the purpose of this essay is to contribute to a better understanding of bloggers' preferences in their relationship with companies and brands and how they choose brands to mention in the blog from their digitally constructed identities. To carry out our study, we chose a qualitative method with an abductive nature where we have carried out semistructured interviews with seven popular bloggers in Sweden. The theoretical framework that forms the basis of our study is divided into three main categories; marketing public relations, word-of-mouth/word-of-blog, and personal brand, where we touch the concepts of relationships, digital dialogues, two-way symmetrical communication, digital identity and source credibility. The result of our study shows that bloggers wish for a professional approach in the relationships with PR practitioners and a personal relationship with the brands. PR practitioners should offer bloggers uniqueness, involvement, news-value and emolument to create beneficial two-way symmetric blog relationships in order to promote the brand. Moreover, this approach is changing the perception of traditional PR, which includes relationships, rather than financing. In our study, we therefore present a definition and model of the term Blog Public Relations (BPR) that is our main contribution to the scientific discourse. Furthermore, our study shows that there are three factors that influence bloggers to deviate from their digital identity in collaboration with companies. Besides that they feel pressured to update the blog, and thus sometimes chose to write about certain products because of it, a high emolument or a really good and professional behavior from PR practitioners affects the commercial balance.

For an affine Weyl group W, we explicitly determine the elements for which the Möbius function of the subposet of affine Grassmannians under the Bruhat order is non-zero by utilizing the quantum Bruhat graph of the classical Weyl group associated to W . Then we examine embedding stable and consistent statistics on the affine Weyl group of type A which permit the definition of an affine infinite symmetric group.
Doctor of Philosophy

Surveys show that consumers tend to avoid traditional marketing channels, leading the practitioners to use earned media channels through public relations (PR). This has also led to the use of covert PR. To understand the use of this communications method, the purpose of this thesis is to study campaigns, which have gained transmission in social media, by investigating how practitioners of three different campaigns motivate the choice to use covert PR. The study is based on a hermeneutic methodology and has an abductive approach. It is carried out by semi-structured elite interviews with six contributors of three different campaigns, using covert PR. The primary data consists of the empery of the interviews, while the secondary data consists of a theoretical framework of excellence in public relations, the PR practice and viral messages. The result of the study indicates the point of view that covert PR has given the campaigns a wider reach. Furthermore the campaigns are described as having gained an extensive viral transmission, which exceeded the expectations of the interviewees. Nevertheless none of the practitioners think they will do a similar campaign again, it seems that they are aware of the risk of covert PR reducing the organisation’s reputation. The analysis also show a contradiction between the interviewees’ position and the presented theory, which might be caused by a perspective on PR as a way of spreading information rather than creating relationships.
Undersökningar visar att konsumenter i allt större utsträckning undviker reklam, vilket har gjort att kommunikationspraktiker i större utsträckning väljer förtjänade kanaler, eller public relations (PR), för att nå sina målgrupper. En följd av det är PR-aktiviteter med dolda avsändare. Med utgångspunkt i den debatt som finns kring metoden är syftet med studien att undersöka PR som fått viral spridning med avseende på hur tre kampanjer utformats och hur praktikerna bakom dessa i efterhand motiverar och resonerar kring valet av dold viral PR. För att få förståelse för fenomenet och varför sådana kampanjer genomförs har studien ett hermeneutiskt förhållningssätt och en abduktiv ansats. Undersökningen har genomförts med en kvalitativ metod genom semistrukturerade elitintervjuer med sex stycken praktiker som jobbat med någon av tre valda kampanjer. Det empiriska materialet i form av intervjuerna utgör studiens primärdata, medan dess sekundärdata består av teorier och tidigare forskning om excellens i public relations, PR i praktiken och viral spridning i sociala medier. Resultatet visar att den dolda avsändaren och dess avslöjande anses bidra till viral spridning. Kampanjerna motiveras med att de nått stora målgrupper, väckt debatt och varit underhållande – och räckvidden har överträffat praktikernas förväntningar. Ändå nämner alla att det inte är önskvärt att förknippas med metoden. Respondenternas utsagor går till viss del emot teorins normativa resonemang, vilket möjligtvis skulle kunna förklaras av en syn på PR som informationsspridande snarare än relationsskapande.

Statistics
Ph.D.
This research work is focused on the balanced and partially balanced incomplete block designs when observations within blocks are correlated. The topic for this dissertation was motivated by a problem in pharmaceutical research, when several treatments are allocated to individuals, and repeated measurements are taken on each individual. In that case, there is correlation among the observations taken on the same individual. Typically, it is reasonable to assume that the observations within individual close to each other are highly correlated than observations that are far away from each other. It is also reasonable to assume that the correlation between any two observations within each individual is same. We have characterized balanced and partially balanced incomplete block designs when observations within blocks are autocorrelated. In Chapter 3, we have provided an explicit expression for the average variance of estimated elementary treatment contrasts for designs obtained by Type I and II series of orthogonal arrays, under autocorrelated errors, and compared them with the corresponding balanced incomplete block designs with uncorrelated errors. The relative efficiency of balanced incomplete block design compared to the corresponding balanced incomplete block design obtained by Types I and II series of orthogonal array under autocorrelated errors does not depend on the number of treatments (v) and is an increasing function of the block size (k). When orthogonal arrays of Type I or Type II do not exist for a given number of treatments, we provided alternative partially balanced designs with autocorrelated errors. In Chapter 4, we rearranged the treatments in each block of symmetric balanced incomplete block designs and used them with autocorrelated error structure of the plots in a block. The C-matrix of estimated treatment effects under autocorrelation was given and the relative efficiency of symmetric balanced incomplete block designs with independent errors compared to the autocorrelated designs is given. In Chapter 5, we discussed the compound symmetry correlation structure within blocks. An explicit expression of the average variance of designs obtained by Type I and II series of orthogonal arrays and symmetric balanced incomplete block designs under compound symmetric errors has been provided and compared them with the corresponding balanced incomplete block designs with uncorrelated errors. Finally, the relative efficiencies of these designs with autocorrelated errors vs. compound symmetric error structure are given
Temple University--Theses

Relação de dispersão é outro nome para a função Hamiltoniana, cujo conhecimento especica completamente a dinâmica de um sistema no formalismo da mecânica classica. Sua escolha está intimamente vinculada às simetrias do sistema e, no contexto cosmologico aqui apresentado, com as simetrias locais obedecidas pelas leis fsicas. Mais ainda, a contribuição da materia na dinâmica cosmologica reflete a escolha do grupo local de simetrias das leis fsicas. Por outro lado, o problema fundamental da cosmologia pode ser definido como a construção de um modelo de evolução temporal de estados que, sob as hipoteses mais simples sobre estados iniciais (digamos, que demande a menor quantidade de informação possível para serem enunciadas), prediga o estado atual observado. O paradigma inacionario é atualmente a ideia que melhor cumpre esta denição, uma vez que prediz que uma grande variedade de condições iniciais leva a aspectos fundamentais do universo observado. Contudo, os mecanismos usuais de realização da inflação sofrem de problemas conceituais. O ponto de vista deste trabalho e que a realização convencional da inflação, isto é, atraves dos campos escalares minimamente acoplados, é a formulação localmente relativisticamente invariante da inflação. A maneira de incluir quebras e deformações da estrutura de simetrias locais na cosmologia é não única e está associado ao chamado problema trans Planckiano da inflação. Analogamente, a motivação conceitual para incluir esse tipo de modicação tampouco é unica. Dependendo do esquema de realização, a versão localmente não relativstica da mesma pode apresentar graves diculdades de conciliação com observações atuais, ou apresentar vantagens conceituais em relacão ao modelo padrão de inflacão, enquanto em conformidade com observações cosmológicas. Da maneira como foi posto o problema fundamental da cosmologia, a escolha das simetrias locais influi na regra de evolução dos estados. O conceito de simetrias encontra sua formulação independente de teorias físicas no formalismo da teoria de grupos, mas consideraremos uma extensão da ideia, de aplicabilidade mais geral, a teoria das algebras de Hopf que, de certo modo, trata das simetrias de estruturas algebricas. Esta extensão é útil inclusive no trato de simetrias dos espacos não comutativos, uma das principais propostas fsicas que em última analise afeta a estrutura de simetrias locais do espaco-tempo. A expressão simetrias locais, por si só, não diz muito sem a consideração de regras de realização. Essas regras dependem da estrutura matematica das observaveis da teoria. Sob hipoteses muito gerais, que não especicam uma teoria em particular, é possível mostrar, não como um teorema matematico formal, mas como uma hipotese tecnicamente bem motivada, que existem apenas dois tipos de teorias fsicas: as classicas e as quânticas. Trabalharemos sob essas hipoteses, as quais se formulam algebricamente assumindo a estrutura de C*-álgebra para as observaveis físicas, outra motivação para o uso das álgebras de Hopf para descrição das simetrias da natureza.
Dispersion relation is another name for the Hamiltonian function whose knowledge completely specifies the dynamics in the formalism of classical mechanics. Its choice is intimately related to the symmetries of the system, and, in the cosmological context here exposed, with the local space-time symmetries obeyed by physical laws. For the other side, the fundamental problem of cosmology can be defined as a construction of a time evolution model of states which, under simplest possible hypothesis concerning initial conditions (say, which demands the minimal amount of information to be specified), predicts the present observed state. The inflationary paradigm is currently the idea which better accomplishes this definition, since it predicts that a great variety of initial conditions lead to essential aspects of observed universe. The usual mechanisms of inflation suffer, however, with conceptual problems. The point of view of this work is that the usual realization of inflation based on weakly coupled scalar fields is the local relativistic invariant realization. The way of including breaks and deformations of the local space-time symmetries is not unique and it is associated to the so called Trans-Planckian problem of inflation. Analogously, the motivation to include this kind of modification is neither unique. Depending of the scheme of realization, the locally non-relativistic version may lead to serious difficulties in conciliation with observations, or to conceptual advantages over standard formulations while in accordance with observational data. In the way that was proposed the fundamental problem of cosmology, the choice of local symmetries affects the rule of evolution of states. The concept of symmetry finds its formulation independently of physical theories in the group theory formalism, but we will consider an extension of the idea, with wider applicability, the theory of Hopf algebras, which is about symmetries of algebraic structures. That extension is also useful to deal with symmetries of non-commutative spaces, one of the main physical proposals that affects the structure of space-time symmetries. The expression, local symmetries, by itself, does not say too much without considering realization rules. Those rules depend on mathematical structure of observables in the theory. Under very general hypothesis that do not specify a particular theory, it is possible to show, not as a formal mathematical theorem, but as a technically well motivated hypothesis, that only two types of physical theories do exist: The classical ones and the quantum ones. We are going to work under those hypothesis, which can be algebraically formulated assuming a C*-algebra structure for physical observables, another motivation for the use of algebraic structures like Hopf algebras for the description of nature\'s symmetries

Cette thèse est consacrée à l’étude de l’équation des ondes sur les espaces symétriques et localement symétriques de type non compact. Un de nos principaux résultats est l’obtention des estimations ponctuelles du noyau pour l’équation des ondes sur les espaces symétriques non compacts de rang supérieur. Elles nous permettent de démontrer la propriété de dispersion et d’établir l’inégalité de Strichartz pour une grande famille de paires admissibles. Nous en déduisions que l’équation des ondes semi-linéaire correspondante est globalement bien posée pour les données initiales de régularité faible. Autrement dit, nous étendons les résultats obtenus sur les espaces hyperboliques réels aux espaces symétriques non compacts de rang général. L’autre partie de nos travaux concerne l'analyse sur les espaces localement symétriques. D’un côté, nous étudions les équations des ondes et de Klein-Gordon sur certains espaces localement symétriques de rang un. D’autre part, nous établissons une caractérisation pour le bas du spectre L2 du laplacien sur les espaces localement symétriques de rang général
This thesis is devoted to the study of the wave equation on symmetric and locally symmetric spaces of noncompact type. One of our main results is to obtain pointwise kernel estimates for the wave equation on noncompact symmetric spaces of higher rank. They allow us to prove the dispersive property and to establish the Strichartz inequality for a large family of admissible pairs. We deduce global well-posedness results for the corresponding semilinear wave equation with low regularity initial data. In other words, we extend the results obtained on real hyperbolic spaces to noncompact symmetric spaces of general rank. The other part of our work concerns analysis on locally symmetric spaces. On the one hand, we study the wave and Klein-Gordon equations on certain locally symmetric spaces of rank one. On the other hand, we establish a characterization for the bottom of L2 spectrum of Laplacian on locally symmetric spaces of general rank

La thèse de Marion Chommaux a pour cadre le « programme de Langlands local », un domaine particulièrement actif et exigeant de la théorie des représentations des groupes p-adiques. Une branche en plein développement en est le « programme de Langlands relatif' », dont une des figures majeures est Dipendra Prasad. Ce dernier a proposé avec Takloo-Bighash en 2011 une conjecture concernant la distinction des séries discrètes des formes intérieures d'un groupe linéaire général sur un corps p-adique par le centralisateur des inversibles d'une extension quadratique de ce corps: la conjecture s'énonce en termes d'invariants galoisiens subtils. Dans sa thèse Marion résout complétement cette conjecture pour les représentations de Steinberg, et elle la démontre pour les cuspidales de niveau zéro dans le cas non-déployé. Dans ce cas un résultat notable est qu'elle obtient même un contre-exemple à une forme plus générale de la conjecture en question. Les techniques utilisées sont diverses. Dans le premier chapitre sur les représentations de Steinberg, c'est le lemme géométrique de Bernstein-Zelevinsky qui joue un rôle prépondérant dans le résultat de classification, mais des invariants analytiques tels que les fonctions L font leur apparition. Dans le second chapitre il s'agit de la théorie des types de Bushnell-Kutzko (plus précisément celle des paires admissibles de Bushnell-Henniart) ainsi que la géométrie de l'immeuble de Bruhat-Tits qui sont les éléments essentiels en théorie des représentations. Une fois la classification des cuspidales de niveau zéro distinguées obtenue, Marion réduit habilement la vérification de la conjecture du côté galoisien à un résultat de Fröhlich et Queyrut
The framework of Marion Chommaux's PhD thesis is a very active and requiring area of representation theory of p-adic groups, called the "local Langlands program''. A highly investigated branch of this program is the ``relative Langlands program'', of which one of the key players is Dipendra Prasad. Together with Takloo-Bighash, he proposed in 2011 a conjecture concerning distinction of discrete series of inner forms of p-adic general linear groups, with respect to the centralizer of the invertibles of a quadratic extension of the base field: this conjecture is in terms of subtle Galois invariants. In her doctoral work, Marion completeley solves this conjecture in the case of Steinberg representations, and proves it for level zero cuspidal representations of split inner forms. In this latter case, it is remarkable that she obtains a counter-example to a more general version of the conjecture. The techniques employed are diverse. In the first chapter on Steinberg representations, the main tool is the Bernstein-Zelevinsky geometric lemma, but some analytical invariants such as L-functions also play a role. In the second chapter the essential ingredients are Bushnell-Kutzko's type theory (more precisely the admissible pairs of Bushnell-Henniart) and the geometry of the Bruhat-Tits building. Once the classification of level zero cuspidal representations is obtained, Marion skilfully reduces the verification of the conjecture to a result of Fröhlich and Queyrut on the Galois side

In this thesis, we analyze the electromagnetic wave propagation in waveguidestructuresexhibiting periodical geometry, including glide symmetry. The analysisis performed using a mode matching technique which correlates the different modecoefficients from separate but, connected regions in the structure. This technique isused to obtain the dispersion diagrams for two one-dimensional periodic structures:a glide-symmetric corrugated metasurface and a coaxial line loaded with periodicholes. The mode matching formulation is presented in Cartesian and cylindricalcoordinate system for the former and the later, respectively. The mode matchingresults are compared to simulated results obtained from the Eigenmode Solver inCST Microwave Studio and are found to agree very well.
I detta examensarbete, analyseras elektromagnetisk v°agutbredning i periodiskav°agledarstrukturer som uppvisar glid symmetri. Analysen genomf¨ordes genom enmod matchnings-teknik som korrelerar de olika mod-koefficienterna fr°an separeraderegioner i strukturen med varandra. Denna teknik anv¨ands f¨or att ta framdispersionsrelationen f¨or tv°a endimensionella periodiska strukturer: en glid symmetriskkorrugerad meta-yta och en koaxial ledare belagd med periodiskt urgr¨opdah°aligheter. Mod matchnings-formuleringen presenteras i Kartesiska och cylindriskakoordinatsystem respektive f¨or de ovan n¨amnda fallen. Mod matchnings-resultatenj¨amf¨ors med data-simulerade resultat erh°allna fr°an CST Microwave Studio och de¨overenst¨ammer v¨al med varandra.

Cette thèse porte sur l’analyse des protocoles cryptographiques. Ce sont des suites d’instructions permettant d’interagir à distance avec un interlocuteur tout en protégeant le contenu sensible de la communication d’une potentielle tierce partie malveillante. Des cas classiques où la confidentialité et l’intégrité de la communication sont critiques sont, parmi d’autres, les paiements et services de santé en ligne, ou le vote électronique. Nous étudions les notions de sécurité définies techniquement par des équivalences observationnelles (ce qui inclut, entre autres, la confidentialité, l’anonymat ou la non-traçabilité). Nous avons conçu un programme, DeepSec, qui, à partir de la description d’un protocole pour un nombre fixé de participants, vérifie de manière entièrement automatisée si le protocole offre une garantie de sécurité donnée de ce type. Nous démontrons ensuite la capacité de cet outil à analyser des scenarios d’attaques complexes à travers plusieurs exemples. Dans un deuxième temps, nous présentons une technique d’optimisation reposant sur l’exploitation de symétries dans les preuves de sécurité. Typiquement, les participants ayant des rôles similaires dans le protocole ont souvent les mêmes instructions à suivre, ce qui induit des tâches redondantes lors de l’analyse. Sur plusieurs exemples, l’utilisation de cette technique d’optimisation a permis de réduire le temps d’analyse de DeepSec de plusieurs ordres de magnitude. Enfin, nous avons également étudié l’aspect théorique du problème afin de déterminer dans quelle mesure l’algorithme de DeepSec pouvait être amélioré (peut-on rendre l’outil plus rapide ?) ou rendu plus expressif (peut-on rendre l’outil capable d’analyser plus de protocoles, i.e., nous débarrasser de certaines de ses limitations ?). Nous avons pour cela fait une analyse de complexité calculatoire complète de l’algorithme de DeepSec, et l’avons intégré à une revue détaillée de l’état de l’art des résultats de complexité dans des contextes similaires. Cette revue minutieuse nous a permis de mettre au jour des variations subtiles dans la formalisation du problème à travers la littérature — parfois ayant un impact sur sa complexité. Nous y incluons de nouveaux résultats et améliorons certains ce ceux passés en revue, offrant une compréhension plus claire du problème
This thesis studies the analysis of cryptographic protocols. They are sequences of instructions permitting to interact with a recipient remotely while protecting the sensitive content of the communication from a potential malicious third party. Classical cases where the confidentiality and the integrity of the communication are critical are, among others, online payments and medical-service booking, or electronic voting. We study notions of security defined technically by observational equivalences (which includes among others confidentiality, anonymity or non-traceability). We designed a program, DeepSec, which, from the description of a protocol for a fixed number of participants, verifies in a fully-automated way whether the protocol offers a security guarantee of this type. We demonstrate the ability of this tool to analyse complex attack scenarios through several examples. After that, we present an optimization technique exploiting symmetries in security proofs. Typically, participants with similar roles in the protocol often have similar instructions to follow, inducing redundant work during the analysis. On several examples, using this technique allowed to reduce the analysis time of DeepSec by several orders of magnitude. Finally, we also studied the theoretical aspect the problem in order to determine to which extent DeepSec’s algorithm could be improved (can we make the tool faster?) or made more expressive (can we get rid of some of the limitations of the tool?). For that we carried out a complete analysis of the computational complexity of DeepSec’s algorithm, and integrated it to a detailed survey of the state of the art regarding complexity results in similar contexts. This meticulous survey allowed us to expose subtle variations in how the problem is formalised across the literature—sometimes impacting its complexity. We also include new results and improve some of the surveyed ones, resulting in a clearer understanding of the problem

The variety of principal minors of nxn symmetric matrices, denoted Zn, can be described naturally as a projection from the Lagrangian Grassmannian. Moreover, Zn is invariant under the action of a group G C GL(2n) isomorphic to (SL(2)xn) x Sn. One may use this symmetry to study the defining ideal of Zn as a G-module via a coupling of classical representation theory and geometry. The need for the equations in the defining ideal comes from applications in matrix theory, probability theory, spectral graph theory and statistical physics. I describe an irreducible G-module of degree 4 polynomials called the hyperdeterminantal module (which is constructed as the span of the G-orbit of Cayley's hyperdeterminant of format 2 x 2 x 2) and show that it that cuts out Zn set theoretically. This result solves the set-theoretic version of a conjecture of Holtz and Sturmfels and gives a collection of necessary and sufficient conditions for when it is possible for a given vector of length 2n to be the principal minors of a symmetric n x n matrix. In addition to solving the Holtz and Sturmfels conjecture, I study Zn as a prototypical G-variety. As a result, I exhibit the use of and further develop techniques from classical representation theory and geometry for studying G-varieties.