Concurrent data structures have found increasingly widespread use in both multicore and distributed computing environments, thereby escalating the priority for verifying their correctness. The thread safe behavior of these concurrent objects is often described using formal semantics known as linearizability, which requires that  every operation in a concurrent object appears to take effect between its invocation and response. Quasi linearizability is a quantitative relaxation of linearizability to allow more implementation freedom for performance optimization.  However, ensuring the quantitative aspects of this new correctness condition is an arduous task. We propose the first method for formally verifying quasi linearizability of the implementation model of a concurrent data structure. The method is based on checking the refinement relation between the implementation model and a specification model via explicit state model checking. It can directly handle multi-threaded programs where each thread can make infinitely many method calls, without requiring the user to manually annotate for the linearization points. We have implemented and evaluated our method in the PAT model checking toolkit.  Our experiments show that the method is effective in verifying quasi linearizability and in detecting its violations. / Master of Science

Under weak turbulence theory, we will use the random thin phase screen model and the Kolmogorov power-law spectrum to derive approximate models for the scintillation index, covariance function of irradiance fluctuations, and temporal spectrum of irradiance fluctuations for collimated beams. In addition, we will provide an expression for the quasi-frequency of a collimated beam and investigate the relationship between the quasi-frequency and the maximum width of the normalized temporal spectrum of irradiance for a collimated beam.

In recent years, the RNA-sequencing (RNA-seq) method, which measures the transcriptome by counting short sequencing reads obtained by high-throughput sequencing, is replacing the microarray technology as the major platform in gene expression studies. The large amount of discrete data in RNA-seq experiments calls for effective analysis methods. In this dissertation, a new method to detect differentially expressed genes based on quasi-likelihood theory is developed in experiments with a completely randomized design with two experimental conditions. The proposed method estimates the variance function empirically and consequently it has similar sensitivities and FDRs across distributions with different variance functions. In a simulation study, the method is shown to have similar sensitivities and FDRs across the data with three different types of variance functions compared with some other popular methods. This method is applied to a real dataset with two experimental conditions along with some competing methods. The new method is then extended to more complex designs such as an experiment with multiple experimental conditions, an experiment with block design and an experiment with factorial design. The same advantages for the new method have been found in simulation studies. This method and some competing methods are applied to three real datasets with complex designs. The new method is also applied to analyze reads per kilobase per million mapped reads (RPKM) data. In the simulation, the method is compared with the Linear Models for Microarray Data (LIMMA) originally developed for microarray analysis (Smyth, 2004) and the question of normalization is also examined. It is shown that the new method and the LIMMA method have similar performance. Further normalization is required for the proper analysis of the RPKM data and the best such normalization is the scaling method. Analyzing raw count data properly has better performance than analyzing the RPKM data. Different normalization and statistical methods are applied to a real dataset with varied gene length across samples. / Thesis / Doctor of Philosophy (PhD)

La plupart des matériaux étudiés en physique de la matière condensée sont à base de fermions massifs vérifiant les relations de dispersion paraboliques usuelles. Récemment, sont apparus un certain nombre de matériaux dotés de relations de dispersion linéaires : le graphène, système purement bidimensionnel et les isolants topologiques, composés tridimensionnels à base de Bismuth où les fermions de Dirac surfaciques coexistent avec les fermions massifs volumiques. À côté de ces deux grandes familles de matériaux de Dirac, on trouve le composé organique α-(BEDT-TTF)2I3, un système quasi-bidimensionnel du point de vue du transport électronique en raison de sa structure cristalline lamellaire et qui présente une phase de Dirac sous forte pression hydrostatique (P>1,5 GPa). Cette phase de Dirac est singulière puisque ses cônes de Dirac sont inclinés, et donc fortement anisotropes, et qu'ils émergent aux côtés d'une bande de porteurs de charge massifs. Ce travail de thèse porte ainsi sur l'étude, à la fois expérimentale et théorique, des effets des spécificités de la phase de Dirac du α-(BEDT-TTF)2I3 sur son transport électronique en régime quantique. Il examine notamment plusieurs modèles théoriques pour tenter d'interpréter les oscillations quantiques apériodiques mesurées dans le composé organique, ainsi que l'impact de l'inclinaison des cônes de Dirac. Les effets de dopage, surfacique et volumique, sur le α-(BEDT-TTF)2I3 sont également discutés. / The physics of most of the materials studied within condensed matter are based on massive fermions which verify the usual parabolic dispersion relations. Recently, a certain number of materials with linear dispersion relation have appeared: graphene, purely bidimensional and topological insulators, tridimensional compounds based on Bismuth where the surfacic Dirac fermions coexist with bulk massive fermions. Alongside these two families of Dirac materials, there is the organic α-(BEDT-TTF)2I3 compound, a quasi-bidimensional system from an electronic transport point of view because of its lamellar crystalline structure and which exhibits a Dirac phase under high hydrostatic pressure (P>1,5 GPa). This Dirac phase is singular: the Dirac cones are tilted, and highly anisotropic, and they emerge with a massive band. This work is then focus on the study, experimentally and theoretically, of the effects of the α-(BEDT-TTF)2I3 Dirac phase specificities on its electronical transport in quantum regime. It examines particularly several theoretical models to understand the aperiodic quantum oscillations measured in the organic compound, and the impact of Dirac cones tilting. Doping effects, surfacic and in the bulk, on the α-(BEDT-TTF)2I3 are also discussed.

Dans cette thèse, nous considérons les chemins possibles pour donner une mesure quantitative du fait que deux espaces ne sont pas quasi-isométriques. De ce point de vue quantitatif, on reprend la définition de quasi-isométrie et on propose une notion de “croissance de distorsion quasi-isométrique” entre deux espaces métriques. Nous révisons notre article [32] où une borne supérieure optimale pour le lemme de Morse est donnée, avec la variante duale que nous appelons Anti-Morse Lemma, et leurs applications.Ensuite, nous nous concentrons sur des bornes inférieures sur la croissance de distorsion quasi-isométrique pour des espaces métriques hyperboliques. Dans cette classe, les espaces de $L^p$-cohomologie fournissent des invariants de quasi-isométrie utiles et les constantes de Poincaré des boules sont leur incarnation quantitative. Nous étudions comment les constantes de Poincaré sont transportées par quasi-isométries. Dans ce but, nous introduisons la notion de transnoyau. Nous calculons les constantes de Poincaré pour les métriques localement homogènes de la forme $dt^2+\sum_ie^{2\mu_it}dx_i^2$, et donnons une borne inférieure sur la croissance de distorsion quasi-isométrique entre ces espaces.Cela nous permet de donner des exemples présentant différents type de croissance de distorsion quasi-isométrique, y compris un exemple sous-linéaire (logarithmique). / In this thesis we discuss possible ways to give quantitative measurement for two spaces not being quasi-isometric. From this quantitative point of view, we reconsider the definition of quasi-isometries and propose a notion of ``quasi-isometric distortion growth'' between two metric spaces. We revise our article [32] where an optimal upper-bound for Morse Lemma is given, together with the dual variant which we call Anti-Morse Lemma, and their applications.Next, we focus on lower bounds on quasi-isometric distortion growth for hyperbolic metric spaces. In this class, $L^p$-cohomology spaces provides useful quasi-isometry invariants and Poincar\'e constants of balls are their quantitative incarnation. We study how Poincar\'e constants are transported by quasi-isometries. For this, we introduce the notion of a cross-kernel. We calculate Poincar\'e constants for locally homogeneous metrics of the form $dt^2+\sum_ie^dx_i^2$, and give a lower bound on quasi-isometric distortion growth among such spaces.This allows us to give examples of different quasi-isometric distortion growths, including a sublinear one (logarithmic).

abstract: In this work, we focused on the stability and reducibility of quasi-periodic systems. We examined the quasi-periodic linear Mathieu equation of the form x ̈+(ä+ϵ[cost+cosùt])x=0 The stability of solutions of Mathieu's equation as a function of parameter values (ä,ϵ) had been analyzed in this work. We used the Floquet type theory to generate stability diagrams which were used to determine the bounded regions of stability in the ä-ù plane for fixed ϵ. In the case of reducibility, we first applied the Lyapunov- Floquet (LF) transformation and modal transformation, which converted the linear part of the system into the Jordan form. Very importantly, quasi-periodic near-identity transformation was applied to reduce the system equations to a constant coefficient system by solving homological equations via harmonic balance. In this process we obtained the reducibility/resonance conditions that needed to be satisfied to convert a quasi-periodic system to a constant one. / Dissertation/Thesis / M.S.Tech Engineering 2012

Robertson and Seymour proved that graphs are well-quasi-ordered by the minor relation. In other words, given infinitely many graphs, one graph contains another as a minor. An application of this theorem is that every property that is closed under deleting vertices, edges, and contracting edges can be characterized by finitely many graphs, and hence can be decided in polynomial time. In this thesis we are concerned with the topological minor relation. We say that a graph G contains another graph H as a topological minor if H can be obtained from a subgraph of G by repeatedly deleting a vertex of degree two and adding an edge incident with the neighbors of the deleted vertex. Unlike the relation of minor, the topological minor relation does not well-quasi-order graphs in general. However, Robertson conjectured in the late 1980's that for every positive integer k, the topological minor relation well-quasi-orders graphs that do not contain a topological minor isomorphic to the path of length k with each edge duplicated. This thesis consists of two main results. The first one is a structure theorem for excluding a fixed graph as a topological minor, which is analogous to a cornerstone result of Robertson and Seymour, who gave such a structure for graphs that exclude a fixed minor. Results for topological minors were previously obtained by Grohe and Marx and by Dvorak, but we push one of the bounds in their theorems to the optimal value. This improvement is needed for the next theorem. The second main result is a proof of Robertson's conjecture. As a corollary, properties on certain graphs closed under deleting vertices, edges, and "suppressing" vertices of degree two can be characterized by finitely many graphs, and hence can be decided in polynomial time.

Since its inception, international aid has been premised on the existence of stable and sovereign recipient states. Official aid relies upon such states for its legitimacy and implementation, and aims to consolidate statehood. In the 1990s, this organising pillar of the international aid system was shaken. The ability of governments to fulfil the basic functions of a sovereign power is now widely questioned. The principle of sovereignty is no longer absolute; rather, it is increasingly contingent upon states' adherence to international, largely Western-defined, norms of behaviour. Where these norms are violated systematically, as in conflict-affected countries, sanctions including trade, political and military measures are deployed. In these 'quasi-states', where sovereignty is contested or weak empirically and juridically, development aid relations are usually suspended and relief the only form of aid available. However, the ability of relief aid to respond to these chronic political emergencies is increasingly questioned. There are increasing demands to make relief more developmental, and for aid to be used to address the cause of crisis - conflict. This thesis examines how aid has worked in a particular type of 'quasi-state': situations of 'post'-conflict transition, and asks whether the new demands on aid in these environments can be met. Examining the cases of rehabilitation assistance to the health sector in Cambodia, Ethiopia and Uganda, it draws three primary conclusions. First, the political meaning, objectives and instruments of relief and development aid are categorically distinct; linking them is ethically and technically problematic. Ethically it implies compromising principles of impartiality and neutrality. Technically, political conditions prevent the transition to more developmental aid instruments. Second, the empirical weakness and juridical ambiguity of statehood in these environments mean that there is no clearly accepted and competent authority to make public policy - no one and everyone owns it. This leads to highly fragmented aid investments that do not provide a basis for the development of public health systems. Third, the absolute scarcity of public resources means that the developmental goal of sustainability is not compatible with that of maximising coverage of health services, level of coverage summary, it suggests that conceptually and operationally the international aid system remains fundamentally ill-equipped to respond to the challenges of chronic political emergencies and their aftermath. 4

This exploratory study was designed to examine counseling skill acquisition for Rehabilitation Counseling education students enrolled in a distance education Practicum I course. The course utilized interactive television (ITV), Desire 2 Learn (D2L), a course management system, and some formalized group meetings for curriculum delivery. Students were asked to provide two audio recordings that served as pre-test and post-test measures of counseling skills. Recordings were analyzed by two evaluators. In addition to the recordings, students completed two survey instruments, an initial demographic questionnaire and a survey of attitudes towards the use of technology in the course that was completed along with the post-test recording. A comparison of pre-test and post-test means on the audio recordings revealed no significant change in counseling skills for students enrolled in this course. There was an increase in the number of empathetic responses, clarifying statements, paraphrasing, questions and closing statements on the post-test recordings but a decrease in attending responses and opening statements. Survey findings indicated that students perceived distance education to be an effective use of their time and improved the quality of course interactions. Students also reported that technology made interacting with their peers difficult and somewhat impersonal. Approximately half of the students agreed that they were comfortable with the course technology. A majority to students indicated they would have preferred a traditional approach to learning counseling skills. These findings have implications for counseling programs currently utilizing ITV or webconferencing to deliver clinical skills courses. It may have broader implications for other clinical skills training programs delivering training via other distance education modalities.

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