Literature on change point analysis mostly requires a sudden change in the data distribution, either in a few parameters or the distribution as a whole. We are interested in the scenario that the variance of data may make a significant jump while the mean of data changes in a smooth fashion. It is motivated by a liver procurement experiment with organ surface temperature monitoring. Blindly applying the existing change point analysis methods to the example can yield erratic change point estimates since the smoothly-changing mean violates the sudden-change assumption. In my dissertation, we propose a penalized weighted least squares approach with an iterative estimation procedure that naturally integrates variance change point detection and smooth mean function estimation. Given the variance components, the mean function is estimated by smoothing splines as the minimizer of the penalized weighted least squares. Given the mean function, we propose a likelihood ratio test statistic for identifying the variance change point. The null distribution of the test statistic is derived together with the rates of convergence of all the parameter estimates. Simulations show excellent performance of the proposed method. Application analysis offers numerical support to the non-invasive organ viability assessment by surface temperature monitoring. The method above can only yield the variance change point of temperature at a single point on the surface of the organ at a time. In practice, an organ is often transplanted as a whole or in part. Therefore, it is generally of more interest to study the variance change point for a chunk of organ. With this motivation, we extend our method to study variance change point for a chunk of the organ surface. Now the variances become functions on a 2D space of locations (longitude and latitude) and the mean is a function on a 3D space of location and time. We model the variance functions by thin-plate splines and the mean function by the tensor product of thin-plate splines and cubic splines. However, the additional dimensions in these functions incur serious computational problems since the sample size, as a product of the number of locations and the number of sampling time points, becomes too large to run the standard multi-dimensional spline models. To overcome the computational hurdle, we introduce a multi-stages subsampling strategy into our modified iterative algorithm. The strategy involves several down-sampling or subsampling steps educated by preliminary statistical measures. We carry out extensive simulations to show that the new method can efficiently cut down the computational cost and make a practically unsolvable problem solvable with reasonable time and satisfactory parameter estimates. Application of the new method to the liver surface temperature monitoring data shows its effectiveness in providing accurate status change information for a portion of or the whole organ. / Ph. D. / The viability evaluation is the key issue in the organ transplant operation. The donated organ must be viable at the time of being transplanted to the recipient. Nowadays, viability evaluation can be assessed by analyzing the temperature data monitored on the organ surface. In my dissertation, I have developed two new statistical methods to evaluate the viability status of a prepared organ by studying the organ surface temperature. The first method I have developed can be used to detect the change of viability status at a spot on the organ surface. The second method I have developed can be used to detect the change of viability condition for the selected organ chunks. In practice, combining these two methods together can provide accurate viability status change information for a portion of or the whole organ effectively.

Les nucléotides et nucléosides sont des molécules essentielles à la vie. Outre leurs fonctions intracellulaires, ils jouent un rôle dans la communication intercellulaire. Les nucléotides et nucléosides sont libérés dans l’espace extracellulaire par différents mécanismes et ensuite rapidement métabolisés par des ecto-nucléotidases. Ils exercent leurs effets paracrines et/ou autocrines en activant des récepteurs présents à la surface membranaire des cellules. Les récepteurs P1, au nombre de quatre (A1, A2A, A2B et A3), sont activés par l’adénosine. Les récepteurs P2X1-7 ont une activité intrinsèque de canal ionique et sont essentiellement activés par l’ATP. Les récepteurs P2Y possèdent sept domaines transmembranaires et sont couplés à des protéines G. A ce jour huit sous-types ont été identifiés :P2Y1,2,4,6,11,12,13,14. Ces récepteurs sont activés par des nucléotides adényliques (ATP et ADP) et/ou uridyliques (UTP, UDP et UDP-glucose). Les récepteurs P1 et P2 modulent l’activité de multiples processus biologiques :système immunitaire (A2A, P2X7, P2Y11,…), agrégation plaquettaire (P2Y1, P2Y12, P2X1), tonus vasculaire, angiogenèse,…<p><p>Notre laboratoire a identifié et caractérisé plusieurs récepteurs P2Y :P2Y4, P2Y6, P2Y11 et P2Y13. Ce dernier est activé par l’ADP et est couplé à une protéine Gi. L’abondance du transcrit P2Y13 murin est caractérisée par l’ordre suivant :rate >> pancréas > foie = cerveau. Afin de déterminer son rôle physiologique, nous avons généré une lignée de souris invalidées pour le récepteur P2Y13. Après avoir validé l’inactivation du gène P2Y13 dans ces souris, nous avons analysé leur phénotype. Les souris P2Y13-/- ne présentent pas d’anomalie évidente :elles sont viables, fertiles et se développent normalement. Etant donné le profil d’expression de ce récepteur, nous avons analysé leur système immunitaire, en particulier les cellules dendritiques (DC). <p>In vivo, l’invalidation du récepteur P2Y13 ne semble pas avoir d’impact sur les réponses inflammatoires (choc septique, infiltration de neutrophiles, test à la formaline) et auto-immunes (uvéorétinite expérimentale). In vitro, nous avons montré que l’ADPβS induit une mobilisation de calcium cytoplasmique dans les DC spléniques et qu’il stimule l’endocytose d’antigènes par celles-ci. L’utilisation de DC transgéniques a permis d’exclure l’implication du récepteur P2Y13 et a montré que ces effets sont médiés par le récepteur P2Y12 qui est également activé par l’ADPβS. Ces observations suggèrent qu’il serait intéressant d’analyser le système immunitaire des souris P2Y12-/-, en particulier les réponses immunes dépendantes des DC. D’autre part, ce travail a débouché sur la mise en évidence d’un effet anti-inflammatoire médié par le récepteur de l’adénosine A2B dans les DC dérivées de la moelle osseuse. Enfin, nous avons récemment mis en évidence un rôle potentiel du récepteur P2Y13 dans le métabolisme des glucides et des lipides. Nous avons observé que les souris P2Y13-/- produisent plus d’insuline en réponse à une injection de glucose que les souris contrôles tandis que leur glycémie ne semble pas altérée. De plus, les souris P2Y13-/- sous régime riche en graisses reproduisent 3 caractéristiques du syndrome métabolique chez l'homme :surpoids, dyslipidémie (augmentation des triglycérides et du non HDL-cholestérol) et hyperinsulinémie.<p><p>Notre travail de thèse débouche donc sur deux conclusions et une perspective :<p>•\ / Doctorat en Sciences / info:eu-repo/semantics/nonPublished

The aim of this thesis is to define the essential syntactic-semantic properties of three types of objectless sentences in present-day Swedish. The three types of objectless sentences are labeled descriptively as follows: Implicit Object Read type (IOR) with pseudo-transitive verbs like läsa ‘read’; Implicit Object Open type (IOO), which involves various sets of transitive verbs like öppna ‘open’ and bära ‘carry’; and Implicit Object Kill type (IOK), which typically involves destruction verbs like döda ‘kill’. The study is framed within Ramchand’s (2008) syntactic model with a three-partite decomposed verb phrase, which distinguishes between two types of objects: RHEMES, which are inserted into a complement position in the verb phrase, and UNDERGOERS, which are inserted into a specifier position. In this work, IOR is argued to be an objectless version of pseudo-transitive verbs with optional RHEMES, whereas IOO and IOK are argued to involve ‘true’ transitive verbs with omitted UNDERGOER objects. As a consequence, the IOR verbs are analyzed as sharing their structure with some verbs usually regarded as intransitive, such as springa ‘run’ and arbeta ‘work’, which can also marginally take RHEME objects. This opens up for a discussion on the transitive- intransitive distinction and the object status of RHEMES, as well as a discussion of lexical knowledge versus encyclopedic knowledge. The distinction of optional RHEMES and syntactically obligatory UNDERGOER objects is argued to arise from event structural differences among sets of verbs, as well as from different verb-object relations that are made possible within the three-partite verb phrase. The structural verb-object relations are argued to be influenced further by encyclopedic associations of particular verbs and by knowledge about the world. In contrast to IOR, IOO and IOK are both argued to involve the omission of an UNDERGOER object of a true transitive verb. In the case of IOO, the object referent is salient and specific, whereas for IOK, the object referent is non-specific. Thus, the restriction on IOO as well as on IOK can be informally phrased in terms of the object only being omissible if it is interpretable, or somewhat more formally, if the free variable can be bound. However, the variable binding is assumed to occur in two distinct ways, further motivating the distinction of IOO and IOK. Whereas the free variable of an IOO object is pragmatically bound, the variable of an IOK object is instead bound by an existential operator above the VP.

This thesis considers the properties of MHS equilibria formed through non-resistive MHD relaxation of analytical non-potential magnetic field models, which contain two null points connected by a generic separator. Four types of analytical magnetic fields are formulated, with different forms of current. The magnetic field model which has a uniform current directed along the separator, is used through the rest of this thesis to form MHS equilibria and to study reconnection. This magnetic field, which is not force-free, embedded in a high-beta plasma, relaxes non-resistively using a 3D MHD code. The relaxation causes the field about the separator to collapse leading to a twisted current layer forming along the separator. The MHS equilibrium current layer slowly becomes stronger, longer, wider and thinner with time. Its properties, and the properties of the plasma, are found to depend on the initial parameters of the magnetic field, which control the geometry of the magnetic configuration. Such a MHS equilibria is used in a high plasma-beta reconnection experiment. An anomalous resistivity ensures that only the central strong current in the separator current layer is dissipated. The reconnection occurs in two phases characterised by fast and slow reconnection, respectively. Waves, launched from the diffusion site, communicate the loss of force balance at the current layer and set up flows in the system. The energy transport in this system is dominated by Ohmic dissipation. Several methods are presented which allow a low plasma-beta value to be approached in the single-separator model. One method is chosen and this model is relaxed non-resistively to form a MHS equilibrium. A twisted current layer grows along the separator, containing stronger current than in the high plasma-beta experiments, and has a local enhancement in pressure inside it. The growth rate of this current layer is similar to that found in the high plasma-beta experiments, however, the current layer becomes thinner and narrower over time.

Dans ce travail de thèse , je présente comment extraire les géométries discrètes de l'espace-temps de la formulation covariante de la gravitaté quantique à boucles, qui est appelé le formalisme de la mousse de spin. LQG est une théorie quantique de la gravité qui non-perturbativement quantifie la relativité générale indépendante d'un fond fixe. Il prédit que la géométrie de l'espace est quantifiée, dans lequel l'aire et le volume ne peuvent prendre que la valeur discrète. L'espace de Hilbert cinématique est engendré par les fonctions du réseau de spin. L'excitation de la géométrie peut être parfaitement visualisée comme des polyèdres floue qui collées à travers leurs facettes. La mousse de spin définit la dynamique de la LQG par une amplitude de la mousse de spin sur un complexe cellulaire avec un état du réseau de spin comme la frontiére. Cette thèse présente deux résultats principaux. Premièrement, la limite semi-classique de l'amplitude de la mousse de spin sur un complexe simplicial arbitraire avec une frontière est complètement étudiée. La géométrie discrète classique de l'espace-temps est reconstruite et classée par les configurations critiques de l'amplitude de la mousse de spin. Deuxièmement, la fonction de trois-point de LQG est calculé. Il coïncide avec le résultat de la gravité discrète. Troisièmement, la description des géométries discrètes de hypersurfaces nulles est explorée dans le cadre de la LQG. En particulier, la géométrie nulle est décrit par une structure singulière euclidienne sur la surface de type espace à deux dimensions définie par un feuilletage de l'espace-temps par hypersurfaces nulles. / In this thesis, I will present how to extract discrete geometries of space-time fromthe covariant formulation of loop quantum gravity (LQG), which is called the spinfoam formalism. LQG is a quantum theory of gravity that non-perturbative quantizesgeneral relativity independent from a fix background. It predicts that the geometryof space is quantized, in which area and volume can only take discrete value. Thekinematical Hilbert space is spanned by Penrose's spin network functions. The excita-tion of geometry can be neatly visualized as fuzzy polyhedra that glued through theirfacets. The spin foam defines the dynamics of LQG by a spin foam amplitude on acellular complex, bounded by the spin network states. There are three main results inthis thesis. First, the semiclassical limit of the spin foam amplitude on an arbitrarysimplicial cellular complex with boundary is studied completely. The classical discretegeometry of space-time is reconstructed and classified by the critical configurations ofthe spin foam amplitude. Second, the three-point function from LQG is calculated.It coincides with the results from discrete gravity. Third, the description of discretegeometries of null hypersurfaces is explored in the context of LQG. In particular, thenull geometry is described by a Euclidean singular structure on the two-dimensionalspacelike surface defined by a foliation of space-time by null hypersurfaces. Its quan-tization is U(1) spin network states which are embedded nontrivially in the unitaryirreducible representations of the Lorentz group.

Este trabalho analisa diacronicamente o parâmetro do sujeito nulo no português do Brasil, mediante a utilização de documentação jurídica - mais especificamente, os depoimentos prestados em processos e inquéritos policiais. Defendemos que esse tipo de documentação consiste em significativa representação da língua falada para épocas pretéritas. Após, verificamos o que os dados neles contidos poderiam informar a respeito do parâmetro do sujeito nulo no português do Brasil na época em que foram produzidos, ou seja, final do século XIX e meados do século XX. Limitamo-nos ao estudo do parâmetro em questão apenas em orações subordinadas, mais especificamente no que denominamos encadeamento de subordinadas, estrutura muito comum no tipo de documento por nós estudado até hoje. Tal estrutura consiste em um grande número de orações subordinadas ligadas a uma mesma oração principal por meio do conectivo que. Por exemplo, \"a testemunhai disse que não cvi sabe quanto a autora tinha no Banco Mauá, [...]; que o que ellai ouvio dizer pelo finado Cavalheiro [...]\" Inicialmente, comparamos tais dados com aqueles contidos em estudo diacrônico clássico sobre o assunto, da autoria de Duarte (1993). Também verificamos o que poderiam nos informar se submetidos às hipóteses formuladas por Barbosa, Duarte e Kato (2005). A análise dos dados permite concluir pela existência de um comportamento esperado para o período analisado, mas ao mesmo tempo contém nuances indicativas das transformações pelas quais viria a passar o estatuto do sujeito nulo no Brasil. / This work analyzes diachronically the pro-drop parameter in Brazilian Portuguese through statements given in a court of law or during police investigation. We believe that this kind of document shows past spoken language. After concluding that these statements can really be a source of spoken language, we extracted data to guide us through the situation of the pro -drop parameter in Brazilian Portuguese, at the time the statements were taken - end of 19th century/middle of 20th century. We only studied subordinate clauses, in a structure we call subordinate clause chain, which is very common in the type of document we chose until today. It consists in many subordinate clauses connected to the same matrix clause by que [that]. E. g., \"a testemunhai disse [the witness said] que não cvi sabe quanto a autora tinha no Banco Mauá, [...]; [that she doesn\'t know how much the complainant had in Mauá Bank,...] que o que ellai ouvio dizer pelo finado Cavalheiro [...]\" [that what she heard the dead Cavalheiro say...] We compared these data with those which supported a classical study in the subject by Duarte (1993). And we also checked what they could inform us if submitted to the hypotheses created by Barbosa, Duarte and Kato (2005). We concluded that the data extracted from the corpus behave just as it was expected for that period of time, but with slight indications of the changes that would occur ahead in time in Brazil.

Na presente pesquisa estudamos o comportamento do sujeito pronominal no português uruguaio (PU) falado na região de fronteira entre Brasil e Uruguai (Santana do Livramento-Rivera). Associando alguns pressupostos da Teoria de Princípios e Parâmetros (CHOMSKY, 1981), mais especificamente o Parâmetro do Sujeito Nulo (pro-drop), e da Sociolinguística Variacionista (WEINREICH, LABOV e HERZOG, 1968), analisamos uma amostra de língua oral composta de falas de 37 informantes, investigando as seguintes questões: (1) no português uruguaio teríamos uma mudança linguística em curso no que se refere ao Parâmetro do Sujeito Nulo, de modo que ele venha a se tornar um sujeito pronominal pleno?; (2) quais são os fatores linguísticos e sociais condicionantes dessa produção e em que direção vai essa tendência, português brasileiro (PB) ou espanhol (E)? A análise dos fatores sociais e linguísticos selecionados permitiu observar que o PU também passa por um processo de mudança paramétrica, ainda que mais lenta, devido ao fato de estar submetido à pressão simultânea de duas línguas, e se apresenta como uma língua em que, em alguns contextos, a realização do sujeito pronominal é plena e, em outros, ainda conserva as características das línguas pro-drop. Confirma-se, ainda, que essa disputa não está terminada, embora haja indícios nos dados da geração mais nova de que as regras do espanhol vêm ganhando alguma força, talvez pela pressão da escola e dos meios de comunicação. Tudo indica, então, que a base do PU é o PB, porém algumas características do E estão presentes nesse aspecto da gramática. A análise realizada confirma a maior parte das hipóteses iniciais e dá indícios de que o PU e o PB poderiam configurar-se como duas línguas distintas, da mesma forma que o PB e o PE, como aponta Galves (1998), isto é, tudo parece indicar que, mesmo quando os enunciados superficialmente se parecem, a língua interna (Língua-I) seria diferente e os enunciados dos falantes teriam estatutos diferentes, algo que, no entanto, será necessário demonstrar com um outro modelo de coleta de dados, de natureza mais introspectiva. / In this research we study the behavior of the pronominal subject in the Uruguayan Portuguese language (PU) spoken in the border region between Brazil and Uruguay (Santana do Livramento-Rivera). Associating some assumptions from the Theory of Principles and Parameters (CHOMSKY, 1981), specifically the Null Subject Parameter (pro-drop), and from the Variationist Sociolinguistics (WEINREICH, LABOV and HERZOG, 1968), we analyze a sample of spoken language consisting of 37 informants, in order to investigate the following questions: (1) would we have in the Uruguayan Portuguese language a language change in progress with regard to the Null Subject Parameter, so that it will become a full pronominal subject? (2) what are the linguistic factors and social conditions of production and in which direction will this trend, Brazilian Portuguese (BP) or Spanish (E)? The analysis of social factors and selected language programs suggests that the PU is also undergoing a process of parametric change, albeit slower, due to the fact of being subjected to the pressure of two languages simultaneously, and is presented as a language that, in some contexts, the performance of the pronominal subject is full, and in others it still retains the characteristics of pro-drop languages. It is also confirmed that this dispute is not over, although there are indications in the data of the younger generation that the rules of Spanish are gaining some strength, maybe due to the pressure of school and the media. The analysis confirms most of our initial hypothesis and provides evidence that the PU and CP could be framed as two distinct languages, in the same way as the PB and PE, as appointed by GALVES (1998), that is, everything seems to indicate that, even when the statements superficially resemble, the internal language (Language I) would be different and the production of the speakers would have different statutes, something which, however, would just be demonstrated by means of another more introspective model of data collection.

Neste trabalho discutimos os principais argumentos da inferência bayesiana subjetivista. Posteriormente, a partir de uma revisão da literatura dos testes de hipóteses, os principais testes são analisados sob a ótica da teoria da decisão, particularmente no que tange às hipóteses precisas. Adicionalmente, funções de perda para testes de significância, seguindo a proposta de Fisher e do FBST, são analisadas e comparadas. / This work discusses the main points of the bayesian subjectivist inference. Posteriorly, from a literature review of hypothesis testing, the main approaches are interpreting from a decision-theoretic viewpoint, particularly regarding the precise hypotheses. Additionally, loss functions for tests of significance, following the proposal of Fisher and FBST, are analyzed and compared.

Dans cette thèse, nous étudions un problème de contrôle et un problème inverse pour les équationsde la chaleur. Notre premier travail concerne la contrôlabilité à zéro pour une équation de la chaleur semi-linéaire. Il est à noter que sans contrôle, la solution est instable et il y aura en général explosion de la solution en un temps fini. Ici, nous proposons un résultat positif de contrôlabilité à zéro sous une hypothèse quantifiée de petitesse sur la donnée initiale. La nouveauté réside en la construction de ce contrôle pour amener la solution à l’état d’équilibre.Notre second travail aborde l’équation de la chaleur rétrograde dans un domaine borné et sous la condition de Dirichlet. Nous nous intéressons à la question suivante: peut-on reconstruire la donnée initiale à partir d’une observation de la solution restreinte à un sous-domaine et à un temps donné? Ce problème est connu pour être mal-posé. Ici, les deux principales méthodes proposées sont: une approche de filtrage des hautes fréquences et une minimisation à la Tikhonov. A chaque fois, nous reconstruisons de manière approchée la solution et quantifions l’erreur d’approximation / My thesis focuses on two main problems in studying the heat equation: Control problem and Inverseproblem.Our first concern is the null controllability of a semilinear heat equation which, if not controlled, can blow up infinite time. Roughly speaking, it consists in analyzing whether the solution of a semilinear heat equation, underthe Dirichlet boundary condition, can be driven to zero by means of a control applied on a subdomain in whichthe equation evolves. Under an assumption on the smallness of the initial data, such control function is builtup. The novelty of our method is computing the control function in a constructive way. Furthermore, anotherachievement of our method is providing a quantitative estimate for the smallness of the size of the initial datawith respect to the control time that ensures the null controllability property.Our second issue is the local backward problem for a linear heat equation. We study here the followingquestion: Can we recover the source of a linear heat equation, under the Dirichlet boundary condition, from theobservation on a subdomain at some time later? This inverse problem is well-known to be an ill-posed problem,i.e their solution (if exists) is unstable with respect to data perturbations. Here, we tackle this problem bytwo different regularization methods: The filtering method and The Tikhonov method. In both methods, thereconstruction formula of the approximate solution is explicitly given. Moreover, we also provide the errorestimate between the exact solution and the regularized one.

Le déferlement mondial des services de télécommunications, impose, aux réseaux qui les supportent, d’augmenter de plus en plus leurs capacités afin de subvenir aux besoins de ses utilisateurs dont le nombre ne cesse de croître. Le spectre radio, ressource de base pour les communications sans fils, ne suit malheureusement pas cette croissance. Même si des marges réutilisables sont disponibles, leur accès est limité par des politiques strictes de gestion du spectre radio-fréquentiel. Pour remédier à cette situation, les organismes régulateurs des télécommunications se dirigent vers un paradigme de gestion plus flexible, en autorisant de nouvelles méthodes basées sur l’accès dynamique au spectre (DSA - dynamic spectrum access) et les radio cognitives (CR - cognitive radio). Dans ce travail doctoral, est proposée une nouvelle technique pour traiter la problématique de la disponibilité du spectre radio-fréquentiel. Appelée multiplexage fréquentiel par sous-espace de Vandermonde (VFDM -Vandermonde-subspace frequency division multiplexing), elle permet à deux technologies d’accès radio (RATs - radio access technologies) de fonctionner côte-a-côte dans un environnement de petites cellules CR. Ceci se fait en partageant la bande radio tout en protégeant des interférences les systèmes pour lesquels le spectre radio avait été originellement réservé. VFDM transmet les données pré-codées dans le noyau du canal interférant entre l’émetteur opportuniste et le récepteur originel en utilisant la sélectivité en fréquence des canaux et duplexage temporel (TDD - time division duplexing). Le travail de cette thèse propose une approche exhaustive du développement de la technologie VFDM, en allant des bases théoriques jusqu’à la démonstration de faisabilité. Ainsi, les bases théoriques proposées ont été en premier lieu analysées. Puis, en partant de ces bases théoriques, VFDM a été graduellement développé vers une chaîne émetteur-récepteur complète. Des résultats significatifs sont apparus à mi-chemin dans la phase de développement, comme par exemple, l’établissement de stratégies de précodage optimales ou la mise en évidence d‘aspects critiques lors de l’implémentation. Sous certaines conditions, VFDM permet aux réseaux secondaires opportunistes d’être utilisés en même temps que le réseau originel, aux seules contraintes de la connaissance des canaux et de l’accroissement de la complexité du système. Au travers des résultats obtenus en simulation, il a été démontré que des taux de transfert de données significatifs peuvent être atteints, et ce, malgré que les capacités de VFDM soient toujours limitées par la taille du sous-espace de Vandermonde du canal interfèrent primaire-secondaire. Finalement, la chaîne émetteur-récepteur développée démontre la faisabilité de cette méthode. / The global deployment of PCS is pushing for more and more network capacity to accommodate an exponentially growing user base. Radio spectrum, the basic resource in radio communications, unfortunately does not follow this growth. Even though the current spectrum usage leaves margins for re-use, it is limited by the current fixed spectrum management policies. To remediate this issue, spectrum regulators are switching to a flexible management paradigm, leveraging new DSA schemes based on CR. In this PhD work, a novel CR-DSA technology is introduced to address spectrum scarcity problem. Called VFDM, it allows two RAT to operate side-by-side in a small-cell CR setting, sharing the band while protecting the legacy system from interference. VFDM transmits data pre-coded on the null-space of the interfering cross channel (channel from the opportunistic transmitter to the legacy receiver), assuming frequency selectivity and TDD communications. This PhD work proposes a rather exhaustive approach to the development of VFDM: to go from the theoretical basis up to a proof-of-concept development. Initially the theoretical background, basis of the technique itself was introduced and analyzed. Then, VFDM was gradually developed from a pure mathematical concept up to a full transceiver. During this development, several important mid-way results were developed, such as the multi-user strategy for pre-coding and critical implementation aspects. VFDM, under certain constraints, has been shown to allow a secondary opportunistic network to successfully be installed along with a legacy primary one at merely the cost of channel knowledge and added complexity. By means of numerical examples, it has been shown that significative rates can be attained, even though VFDM's performance is constrained by the size of the Vandermonde-subspace of the interfering channel between the secondary transmitter and primary receiver. Finally, a working VFDM transceiver implementation is shown, providing a proof-of-concept of the technique.