It is well known that the generation of random vectors with non-independent components is difficult. Nevertheless, we propose a new and very simple generation algorithm for multivariate linear densities over point-symmetric domains. Among other applications it can be used to design a simple decomposition-rejection algorithm for multivariate concave distributions. / Series: Research Report Series / Department of Statistics and Mathematics

Many companies today are using some form of uniforms for employees. This research is an exploration of the role of uniforms in contributing to the embedding and transmitting of organizational culture. Culture is the experiences and common learning of the organization that results in shared values and beliefs. According to Schein (1985: 14) culture has three levels, namely: artifacts, values, and basic underlying assumptions. The first level of the culture consists of the physical constructs of the organization, and therefore includes the uniforms, which is the focus of this study. Schein (1985: 223) further proposes that culture can be embedded and transmitted through various mechanisms. The research was conducted in the constructivist paradigm, at a tertiary institution of higher learning in Eastern Cape, South Africa. To ensure triangulation, three sources of data were used, namely: documentation; observation; and both individual and focus group interviews. The researcher argues that uniforms played a role in the embedding of the sample organization’s three levels of culture, which were expressed in terms of Hofstede’s (1991: 07) culture dimensions. Firstly, the use of the different uniforms by different groups, as well as the ranking indicated by the uniforms, played a role in embedding the high power distance culture. Secondly, the symbolism of security portrayed by the uniform played a role in embedding the high uncertainty avoidance culture. Thirdly, it was found that the uniform created unity amongst groups, resulting in greater expression of collectivism. Fourthly, the use of sensible and practical uniforms plays a role in embedding the feminine culture where competitiveness is avoided and relationships are nurtured. Lastly, the uniform plays a possible role in transforming the culture from short-term to a long-term orientation that focuses on the future.

The relationship between the convergence of a sequence of self mappings of a metric space and their fixed points, known as the stability (or continuity) of fixed points has been of continuing interest and widely studied in fixed point theory. In this thesis we study the stability of common fixed points in a Hausdorff uniform space whose uniformity is generated by a family of pseudometrics, by using some general notations of convergence. These results are then extended to 2-metric spaces due to S. Gähler. In addition, a well-known theorem of T. Suzuki that generalized the Banach Contraction Principle is also extended to 2-metric spaces and applied to obtain a coincidence theorem for a pair of mappings on an arbitrary set with values in a 2-metric space. Further, we prove the existence of coincidence and fixed points of Ćirić type weakly generalized contractions in metric spaces. Subsequently, the above result is utilized to discuss applications to the convergence of modified Mann and Ishikawa iterations in a convex metric space. Finally, we obtain coincidence, fixed and stationary point results for multi-valued and hybrid pairs of mappings on a metric space.

Nous proposons un nouveau schéma d’échantillonnage non uniforme périodique appelé Système d’Échantillonnage Non Uniforme en Radio Intelligente (SENURI). Notre schéma détecte la localisation spectrale des bandes actives dans la bande totale échantillonnée afin de réduire la fréquence moyenne d’échantillonnage, le nombre d’échantillons prélevé et par conséquent la consommation d’énergie au niveau du traitement numérique. La fréquence moyenne d’échantillonnage du SENURI dépend uniquement du nombre de bandes contenues dans le signal d’entrée x(t). Il est nettement plus performant, en termes d’erreur quadratique, qu’une architecture classique d’échantillonnage non uniforme périodique constituée de p branches, lorsque le spectre de x(t) change dynamiquement. / In this work we consider the problem of designing an effective sampling scheme for sparse multi-band signals. Based on previous results on periodic non-uniform sampling (Multi-Coset) and using the well known Non-Uniform Fourier Transform through Bartlett’s method for Power Spectral Density estimation, we propose a new sampling scheme named the Dynamic Single Branch Non-uniform Sampler (DSB-NUS). The idea of the proposed scheme is to reduce the average sampling frequency, the number of samples collected, and consequently the power consumption of the Analog to Digital Converter (ADC). In addition to that our proposed method detects the location of the bands in order to adapt the sampling rate. In this thesis, we show through simulation results that compared to existing multi-coset based samplers, our proposed sampler provides superior performance, both in terms of sampling rate and energy consumption. It is notconstrained by the inflexibility of hardware circuitry and is easily reconfigurable. We also show the effect of the false detection of active bands on the average sampling rate of our new adaptive non-uniform sub-Nyquist sampler scheme.

In the first part of this thesis, we present the first non-trivial small value estimate that applies to an algebraic group of dimension 2 and which involves large sets of points. The algebraic group that we consider is the product ℂ× ℂ*, of the additive group ℂ by the multiplicative group ℂ*. Our main result assumes the existence of a sequence (PD)D ≥1 of non-zero polynomials in ℤ [X1, X2] taking small absolute values at many translates of a fixed point (ξ, η) in ℂ × ℂ* by consecutive multiples of a rational point (r, s) ∈ (ℚ*)2 with s = ±1. Under precise conditions on the size of the coefficients of the polynomials PD, the number of translates of (ξ, η) and the absolute values of the polynomials PD at these points, we conclude that both ξ and η are algebraic over ℚ. We also show that the conditions that we impose are close from being best possible upon comparing them with what can be achieved through an application of Dirichlet’s box principle. In the second part of the thesis, we consider points of the form θ = (1,θ1 , . . . ,θd-1 ,ξ) where {1,θ1 , . . . ,θd-1 } is a basis of a real number field K of degree d ≥ 2 over ℚ and where ξ is a real number not in K. Our main results provide sharp upper bounds for the uniform exponent of approximation to θ by rational points, denoted λ ̂(θ), and for its dual uniform exponent of approximation, denoted τ ̂(θ). For d = 2, these estimates are best possible thanks to recent work of Roy. We do not know if they are best possible for other values of d. However, in Chapter 2, we provide additional information about rational approximations to such a point θ assuming that its exponent λ ̂(θ) achieves our upper bound. In the course of the proofs, we introduce new constructions which are interesting by themselves and should be useful for future research.

This project will focus on finding formulas for E[N(t)] using one of the classical problems in the discipline first, and then extending the scope of the problem to include overall times greater than the time t in the original problem. The expected values in these cases will be found using the uniform and exponential distributions of random variables.

Le 10 septembre 2015, l'OHADA s'est dotée d'un nouveau droit des entreprises en difficulté, à la faveur d'une réforme de l 'Acte uniforme portant organisation des procédures collectives d'apurement du passif (AUPC). En effet, huit ans après les premiers travaux d'amendement, l'AUPC révisé a enfin été adopté lors de la 40ème réunion du Conseil des Ministres de l'OHADA tenue à Grand Bassam (Côte d'Ivoire). Le 24 décembre de la même année, conformément aux textes communautaires, ledit Acte est entré en vigueur dans l'ensemble de l'espace OHADA. L'évènement n'est pas sans importance dans la mesure où l'ancien texte avait clairement montré son incapacité à sauvegarder les entreprises viables et à liquider rapidement celles qui ne l'étaient plus. L'un des points marquants de cette réforme est sans doute la place de choix accordée à la prévention des difficultés des entreprises par le législateur. En effet, puisque prévenir vaut mieux que guérir, ce dernier a pris le soin, non seulement d'améliorer le dispositif préexistant à savoir le règlement préventif, mais a également introduit un nouveau procédé préventif inspiré du droit français à savoir la conciliation. Il n'a pas manqué d'organiser le statut des mandataires judiciaires qui interviennent tant en matière préventive, qu'en matière curative. Au soir de cette réforme, deux questions peuvent principalement susciter l'intérêt. Premièrement, on peut se demander ce .qui a concrètement changé dans le dispositif de prévention des difficultés des entreprises en droit OHADA, et, deuxièmement, on peut d'ores et déjà s'interroger sur les moyens d'améliorer la réception de ce nouveau droit par ses destinataires à savoir les acteurs économiques, les praticiens et les magistrats. Les pistes de réponse apportées à ces questions faciliteront on l'espère la mise en œuvre de cette nouvelle politique préventive de l'OHADA. / On September 10, 2015, OHADA adopted a new law for companies in difficulty through reform of Uniform Act organizing Bankruptcy Proceedings for the wiping off debts . Indeed, eight years after the first works of amendment, the revised law has finally been adopted at Grand Bassam (Ivory Coast), during the 40th meeting of OHADA's Council of Ministers. The event is not unimportant insofar as the old text clearly showed its inability to safeguard viable enterprises and to liquidate quickly those that were no longer viable. On 24 December of the same year, in accordance with the Community texts, the new law came into force in the entire OHADA's space. One of the striking points of this reform is doubtless the special place granted to the prevention of the difficulties of companies by the legislator. Indeed, since prevention is better than cure, the legislator improved the old procedure, but also introduce a new one named « conciliation ». He has not failed to organize the status of judicial officers who intervene in both preventive and curative matters. Following this reform, two questions can mainly arouse the interest. Firstly, one can wonder what really changed in the legal prevention of the difficulties of the companies in OHADA's space, and secondly, one can wonder right now about the means of improving the reception of this law by his recipients namely debtors, experts and magistrates. The answers to these questions will hopefully facilitate the implementation of this new OHADA preventive policy.

Fourier pseudo-spectral method on equispaced grid is one of the approaches in turbulence simulation, to compute derivative of discrete data, using fast Fourier Transform (FFT) and gives low dispersion and dissipation errors. In many turbulent flows the dynamically important scales of motion are concentrated in certain regions which requires a coarser grid for higher accuracy. A coarser grid in other regions minimizes the memory requirement. This requires the use of Non-equispaced Fast Fourier Transform (NFFT) to compute the Fourier transform, by solving a system of linear equations. To achieve similar accuracy, the NFFT needs to return more Fourier coefficients than the number of non-equispaced gridpoints, making it an under-determined system. The minimum L2 norm solution of the system is refined using an iterative reconstruction algorithm, FOCUSS. The NFFT and FOCUSS algorithms yield accurate results with smaller test case of a Direct Numerical Simulation on a grid of 64 gridpoints in each dimension, using Taylor green initial condition. The computational speed for this case was found to be unacceptably slow and few methods to improve the performance have been discussed. The approach of NFFT and FOCUSS was tested on a line extracted from 3-dimensional turbulent flow field. Fourier transform of the extracted line, sampled on 1024 non-equispaced gridpoints, computed for 2048 coefficients and the corresponding numerical derivative are found to be inaccurate. It can be observed that the NFFT and FOCUSS approach works for sparse Fourier transform, but not for turbulent fields having a wideband Fourier transform.

This thesis aims to highlight the smock-dress within the context of Soviet-Estonia during the post-war epoch, ca. 1950s until 1990s. Through Mauss’s socio-anthropological tripoint view, the concepts and identities of the smock-dress are studied from the angles of biology, sociology and psychology. The intention is to show its widespread use amongst Soviet- Estonian women and their remembrance of it, in accordance with the Soviet ideological structures. Using semi-structured interviews, I have assembled oral history from women who attain this historical retrospective, aiming to depict the smock-dress as both a concept and an object, thus functioning as an emblem of Soviet society rather than a historical artefact. Relying on the terms nostalgia, socio-cultural belonging and phenomenology, I seek to capture the smock-dress as both a vestiary phenomenon and representation of social structures. Thus, creating a dual identity, individual and collective, through its usage, showing that sartorial fashion encompasses more than just emotions and promoted stylistics.

This master's thesis emerges from the research in the field of uniform marker fields for augmented reality and broadens it by the possibility of generating colored marker fields based on arbitrary pictures. The thesis describes basics of augmented reality and explains the ideas from the Uniform Marker Fields paper. Presented is a program for generating colored marker fields as well as a tool for detecting markers and evaluating success rate of the detection. In addition, the work proposes a study of color constancy in the process of printing and recording. This study exceeds the scope of the requirements for this master's thesis; the knowledge can be used in arbitrary applications that use colors to code information. Finally, the integration of the knowledge into the marker field generating algorithm and resulting improvement of detection success rate are discussed.