We consider the Volter-Salnikov model describing the dynamics of the flow chemical reactor. In the work, a study of deterministic model was performed, deterministic system attractors were defined, bifurcation diagram was constructed. For stochastic model, we analyzed a response of attractors (equilibria and cycles) on sensitivity to noise. With the help of confidence domains, a geometrical description of the dispersion of random states was given, noise-induced transitions were investigated, and of critical values of the noise intensity were estimated. We have constructed a feedback regulator that allows to provide the desired stochastic sensitivity of the system. / В работе рассматривается модель Вольтера-Сальникова, описывающая динамику проточного химического реактора. В работе было проведено исследование детерминированной модели, определены детерминированные аттракторы системы, построена бифуркационная диаграмма. Для стохастической модели проведен анализ аттракторов системы (равновесий и циклов) на чувствительность к шуму. С помощью доверительных областей было дано геометрическое описание областей рассеивания случайных состояний. С помощью доверительных областей исследованы индуцированные шумом переходы, проведена оценка критических значений интенсивности шума. В работе построен управляющий регулятор, позволяющий обеспечить в системе желаемую стохастическую чувствительность.

Работа содержит описание построения доверительной полосы стохастического хаоса и реализацию алгоритмов исследования n-мерных моделей. В работе рассматривается дискретная модель, представленная в виде нелинейной динамической системы разностных уравнений, которая описывает динамику взаимодействия потребителей. Выделяются две задачи, которые были поставлены и выполнены в рамках данной работы для расширения программного инструментария исследования динамических систем такого рода. Для двумерного случая осуществляется стохастический анализ чувствительности хаоса через построение доверительной области с использованием критических линий. Помимо этого, описывается разработанный и реализованный алгоритм построения внешней границы хаоса. Производится переход к n-мерному варианту модели (взаимодействие n потребителей). Выделяется 4 алгоритма для исследования n-мерной модели: 1. построение фазовой траектории, 2. построение бифуркационной диаграммы, 3. построение карты режимов, 4. построение показателей Ляпунова. Описывается реализация данных алгоритмов с уклоном в параллельные вычисления. Реализация алгоритмов выполнена на языке программирования C# (платформа .NET) в виде консольного приложения для запуска параллельных вычислений на вычислительном кластере УрФУ. / The work contains description of confidence band construction of a stochastic chaos and realization of algorithms for n-dimensional models studying. The thesis considers a discrete model presented in the form of a nonlinear dynamic system of difference equations, which describes the dynamic of consumer interaction. There are two task that were set and performed in this work to expand the software tools for research dynamic sys-tems of this kind. For the two-dimensional case, a stochastic analysis of the sensitivity of chaos is carried out through the construction of a confidence band using critical lines. In addition, there is description and implementation of algorithm, that can build outer boundary of chaos. A transition is made to the n-dimensional version of the model (interaction of n consumers). There are 4 algorithms for studying the n-dimensional model: 1. phase trajectory building, 2. bifurcation diagram building, 3. mode map building, 4. Lyapunov components building. Algorithm implementation is described with a bias in parallel computations. The algorithms are implemented with C# programming language (.NET platform) in the form of a console application for running parallel computations on the computing cluster of the Ural Federal University.

La prévalence et la persistance de la violence en contexte conjugal sont préoccupantes dans les communautés autochtones (Brassard et al., 2011, 2015). En effet, les hommes (54 %) et les femmes (61 %) autochtones sont plus susceptibles d’être victimes de violence en contexte conjugal que les allochtones (36 % et 44 %, respectivement) (Cotter, 2021). La présente étude vise à comprendre comment les hommes autochtones mettent fin à la violence en contexte conjugal. D’une part, l’objectif est d’explorer le sens donné à l’arrêt de la violence en contexte conjugal. D’autre part, l’étude s’intéresse aux récits et aux processus de bifurcation vers cet arrêt de la violence. Des entretiens qualitatifs ont été menés auprès de six hommes innus et innus-naskapis ayant vécu de la violence bidirectionnelle ou unidirectionnelle. Les résultats démontrent que la plupart des hommes identifient les contextes coloniaux, communautaires et familiaux comme des sources de la violence en contexte conjugal. L’intersection entre un contexte d’épuisement et de déstabilisation crée un environnement propice aux processus de bifurcation vers l’arrêt de la violence en contexte conjugal. Trois types de processus de bifurcation sont développés, mettant en évidence différentes conceptions de l’arrêt de la violence : 1) un processus « spontané, mais inachevé », 2) un processus « constant et efficient » et 3) un processus « mouvementé et abouti ». Ces processus impliquent des apprentissages sur le passé, la violence et la communauté pour développer une posture non-violente. Souvent accompagnés de diverses sources de soutien, les hommes résolvent les sources de la violence afin d’apaiser leurs souffrances et ainsi réagir différemment aux expériences éprouvantes. / The prevalence and persistence of violence within the conjugal context in Indigenous communities are concerning (Brassard et al., 2012, 2015). In fact, Indigenous men (54%) and women (61%) are more likely to be victims of violence within the conjugal context than non-Indigenous people (36% and 44%, respectively) (Cotter, 2021). This study aims to understand how Indigenous men end violence within the conjugal context. On the one hand, the objective is to explore the meaning given to ending violence within the conjugal context. On the other hand, the study focuses on the narratives and bifurcation processes towards ending violence. Qualitative interviews were conducted with six Innu and Innu-Naskapi men who had experienced bidirectional or unidirectional violence. Findings show that most men identify colonial, community, and family contexts as sources of violence within the conjugal context. The intersection between a context of exhaustion and destabilization creates an environment conducive to the bifurcation processes towards ending violence within the conjugal context. Three types of bifurcation processes are proposed, highlighting different conceptions of violence cessation: 1) a “spontaneous, but incomplete” process, 2) a “constant and efficient” process and 3) a “hectic and thorough” process. These processes involve learning about the past, violence and the community, in order to develop a non-violent posture. Often accompanied by various sources of support, men resolve the sources of violence to alleviate their suffering and thus react differently to distressing experiences.

No description available.

The static and dynamic response of lattice materials is investigated to disclose and control the connection between microstructure and effective behavior. The analytical methods developed in the thesis aim at providing a new understanding of material instabilities and strain localizations as well as effective tools for controlling wave propagation in lattice structures. The time-harmonic dynamics of arbitrary beam lattices, deforming flexurally and axially in a plane, is formulated analytically to analyze the influence of the mechanical parameters on the dispersion properties of the spectrum of Floquet-Bloch waves. Several forms of dynamic localizations are shown to occur for in-plane wave propagation of grid-like elastic lattices. It is demonstrated that lattices of rods, despite being `simple' structures, can exhibit a completely different channeled response depending on the characteristics of the forcing source (i.e. frequency and direction) as well as on the slenderness of the elastic links. It is also shown how the lattice parameters can be tuned to attain specific dispersion properties, such as flat bands and sharp Dirac cones. In the research field of material instabilities, a key result proposed in this thesis is the development of both static and dynamic homogenization methods capable of accounting for second-order effects in the macroscopic response of prestressed lattices. These methods, the former based on an incremental strain-energy equivalence and the latter based on the asymptotic analysis of lattice waves, allow the identification of the incremental constitutive operator capturing the macroscopic incremental response of arbitrary lattice configurations. The homogenization framework has allowed the systematic analysis of prestress-induced phenomena on the incremental response of both the lattice structure and its `effective' elastic solid, which in turn has enabled the identification of the complex interplay between microstructure, prestress, loss of ellipticity (shear band formation) and short-wavelength bifurcations. Potential new applications for the control of wave propagation are also shown to be possible by leveraging the inclusion of second-order terms in the incremental dynamics. In particular, the tunability of the prestress state in a square lattice structure has been exploited to obtain dynamic interfaces with designable transmission properties. The interface can be introduced in a material domain by selectively prestressing the desired set of ligaments and the prestress level can be tuned to achieve total reflection, negative refraction, and wave channeling. The obtained results open new possibilities for the realization of engineered materials endowed with a desired constitutive response, as well as to enable the identification of novel dynamic material instabilities.

Signalverarbeitung im Nervensystem hängt sowohl von der Netzwerkstruktur, als auch den zellulären Eigenschaften der Nervenzellen ab. In dieser Abhandlung werden zwei zelluläre Eigenschaften im Hinblick auf ihre funktionellen Anpassungsmöglichkeiten untersucht: Es wird gezeigt, dass neuronale Morphologie die Signalweiterleitung unter Berücksichtigung energetischer Beschränkungen verstärken kann, und dass selbst kleine Änderungen in biophysikalischen Parametern die Aktivierungsbifurkation in Nervenzellen, und damit deren Informationskodierung, wechseln können. Im ersten Teil dieser Abhandlung wird, unter Verwendung von mathematischen Modellen und Daten, die Hypothese aufgestellt, dass Energie-effiziente Signalweiterleitung als starker Evolutionsdruck für unterschiedliche Zellkörperlagen bei Nervenzellen wirkt. Um Energie zu sparen, kann die Signalweiterleitung vom Dendrit zum Axon verstärkt werden, indem relativ kleine Zellkörper zwischen Dendrit und Axon eingebaut werden, während relativ große Zellkörper besser ausgelagert werden. Im zweiten Teil wird gezeigt, dass biophysikalische Parameter, wie Temperatur, Membranwiderstand oder Kapazität, den Feuermechanismus des Neurons ändern, und damit gleichfalls Aktionspotential-basierte Informationsverarbeitung. Diese Arbeit identifiziert die sogenannte "saddle-node-loop" (Sattel-Knoten-Schlaufe) Bifurkation als den Übergang, der besonders drastische funktionale Auswirkungen hat. Neben der Änderung neuronaler Filtereigenschaften sowie der Ankopplung an Stimuli, führt die "saddle-node-loop" Bifurkation zu einer Erhöhung der Netzwerk-Synchronisation, was möglicherweise für das Auslösen von Anfällen durch Temperatur, wie bei Fieberkrämpfen, interessant sein könnte. / Signal processing in nervous systems is shaped by the connectome as well as the cellular properties of nerve cells. In this thesis, two cellular properties are investigated with respect to the functional adaptations they provide: It is shown that neuronal morphology can improve signal transmission under energetic constraints, and that even small changes in biophysical parameters can switch spike generation, and thus information encoding. In the first project of the thesis, mathematical modeling and data are deployed to suggest energy-efficient signaling as a major evolutionary pressure behind morphological adaptations of cell body location: In order to save energy, the electrical signal transmission from dendrite to axon can be enhanced if a relatively small cell body is located between dendrite and axon, while a relatively large cell body should be externalized. In the second project, it is shown that biophysical parameters, such as temperature, membrane leak or capacitance, can transform neuronal excitability (i.e., the spike onset bifurcation) and, with that, spike-based information processing. This thesis identifies the so-called saddle-node-loop bifurcation as the transition with particularly drastic functional implications. Besides altering neuronal filters and stimulus locking, the saddle-node-loop bifurcation leads to an increase in network synchronization, which may potentially be relevant for the initiation of seizures in response to increased temperature, such as during fever cramps.

The purpose of this study is to explore the nature of dynamic relationships within families, and indicating how the decision to divorce may result from a family's difficulty in adjusting to new changes and stressors. Thus, divorce results in the redefinition of a nuclear system. This study made use of social constructionism as its epistemological framework. By means of in-depth one-on-one interviews, the researcher was able to hear the narratives of all six participants. Hermeneutics was used to analyze the data. The participants' stories were reencountered through the researcher's own frame of reference in which common themes of the divorce process were co-constructed. These themes were later elaborated on and a comparative analysis was undertaken to link them to the available literature. The information gained from the study could contribute to existing research on the impact of divorce, family reorganization following a divorce, and offer a new perspective in understanding family systems. / Clinical Psychology / M.A. (Clinical Psychology)

The professional development of a career counselling intern on a satellite campus at a distance education institution was facilitated with the use of a heutagogic learning strategy. The heutagogic learning process was recorded by reflective writing based on Kolb's experiential learning model. This research is a disquisition of the reflective dataset. The research is an autoethnographic case study in the constructionist paradigm with a creative analysis process. During the research process features about the benefits of heutagogic learning in the professional development of the career counselling intern were critically constructed. The findings of the research are captured in memescapes showing mindset changes and mental transformations on patterns which describe the theory-praxis gap, diversity, wellness, the macro-ethic. The recommendations include the hope that these findings will feed through to inform future career counselling internships in the IOP field. / Industrial & Organisational Psychology / MCom (Industrial and Organisational Psychology)

The professional development of a career counselling intern on a satellite campus at a distance education institution was facilitated with the use of a heutagogic learning strategy. The heutagogic learning process was recorded by reflective writing based on Kolb's experiential learning model. This research is a disquisition of the reflective dataset. The research is an autoethnographic case study in the constructionist paradigm with a creative analysis process. During the research process features about the benefits of heutagogic learning in the professional development of the career counselling intern were critically constructed. The findings of the research are captured in memescapes showing mindset changes and mental transformations on patterns which describe the theory-praxis gap, diversity, wellness, the macro-ethic. The recommendations include the hope that these findings will feed through to inform future career counselling internships in the IOP field. / Industrial and Organisational Psychology / M. Com. (Industrial and Organisational Psychology)

Nesta dissertação, tratamos do estudo das bifurcações de um modelo bi-dimensional de presa-predador, que estende e aperfeiçoa o sistema de Lotka-Volterra. Tal modelo apresenta cinco parâmetros e uma função resposta não monotônica do tipo Holling IV: $$ \\left\\{\\begin \\dot=x(1-\\lambda x-\\frac{\\alpha x^2+\\beta x +1})\\\\ \\dot=y(-\\delta-\\mu y+\\frac{\\alpha x^2+\\beta x +1}) \\end ight. $$ Estudamos as bifurcações do tipo sela-nó, Hopf, transcrítica, Bogdanov-Takens e Bogdanov-Takens degenerada. O método dos centros organizadores é usado para estudar o comportamento qualitativo do diagrama de bifurcação. / In this work are studied the bifurcations of a bi-dimensional predator-prey model, which extends and improves the Volterra-Lotka system. This model has five parameters and a non-monotonic response function of Holling IV type: $$ \\left\\{\\begin \\dot=x(1-\\lambda x-\\frac{\\alpha x^2+\\beta x +1})\\\\ \\dot=y(-\\delta-\\mu y+\\frac{\\alpha x^2+\\beta x +1}) \\end ight. $$ They studied the sadle-node, Hopf, transcritic, Bogdanov-Takens and degenerate Bogdanov-Takens bifurcations. The method of organising centers is used to study the qualitative behavior of the bifurcation diagram.