Ett av nyckelbegreppen i Henri Bergson filosofi är Nuflödet. Bergson använder nuflödet för att beskriva hur varat i tiden är konstituerat som rörligt. I denna uppsats undersöker jag vad som är frihetens plats i nuflödet genom att studera hur Bergsons tankar om de mänskliga villkoren, intuitionen, livet och evolutionen utvecklas i Tiden och den fria viljan - En studie i omedelbara medvetandefakta (1889), Intuition och intelligens – Introduktion till metafysiken (1903) samt Creative Evolution (1907). För att se intuitionens roll för friheten i Bergsons filosofi har jag gått i dialog med Gilles Deleuzes ”Intuition as a method” (Bergsonism, 1988) samt "Lecture Course on Chapter Three of Bergson's "Creative Evolution"(1960). Deleuze klargör vikten av Bergsons intuitiva metod för att nå frihet i nuflödet. För att göra en kritisk jämförelse vänder jag mig sedan till Daniela Vallega-Neus artikel "Disseminating Time: Durations, Configurations, and Chance." (2017). Denna jämförelse öppnar upp för en vidare förståelse av vad frihet inifrån nuflödet skulle kunna vara. Den möjliggör även en argumentation om dans som en alternativ metod för att uppnå frihet i nuflödet. / One of the key concepts of Henri Bergson’s philosophy is Duration. Bergson uses duration to describe how being in time is constituted as moving. In this thesis I am searching for what room there is for freedom within duration by studying how Bergson’s thoughts about human conditions, intuition, life and evolution evolve in Time and Free Will (1889), An Introduction to Metaphysics (1903) and Creative Evolution (1907). I do this in dialogue with Gilles Deleuze´s ”Intuition as a method” (Bergsonism, 1966) and “Lecture Course on Chapter Three of Bergson's "Creative Evolution"”(1960). Deleuze clarifies the importance of Bergson’s intuitive method to reach freedom in duration. To make a critical comparison I use the article "Disseminating Time: Durations, Configurations, and Chance." (2017) written by Daniela Vallega-Neu. This comparison opens up to a broader sense of how freedom within duration could be conceived. It also makes an argument for dancing as an alternative method in order to reach freedom in duration possible.

abstract: Breeding seeds to include desirable traits (increased yield, drought/temperature resistance, etc.) is a growing and important method of establishing food security. However, besides breeder intuition, few decision-making tools exist that can provide the breeders with credible evidence to make decisions on which seeds to progress to further stages of development. This thesis attempts to create a chance-constrained knapsack optimization model, which the breeder can use to make better decisions about seed progression and help reduce the levels of risk in their selections. The model’s objective is to select seed varieties out of a larger pool of varieties and maximize the average yield of the “knapsack” based on meeting some risk criteria. Two models are created for different cases. First is the risk reduction model which seeks to reduce the risk of getting a bad yield but still maximize the total yield. The second model considers the possibility of adverse environmental effects and seeks to mitigate the negative effects it could have on the total yield. In practice, breeders can use these models to better quantify uncertainty in selecting seed varieties / Dissertation/Thesis / Masters Thesis Industrial Engineering 2019

Le problème généralisé des moments (PGM) est un problème d'optimisation linéaire sur des espaces de mesures. Il permet de modéliser simplement un grand nombre d'applications. En toute généralité il est impossible à résoudre mais si ses données sont des polynômes et des ensembles semi-algébriques alors on peut définir une hiérarchie de relaxations semidéfinies (SDP) - la hiérarchie moments-sommes-de-carrés (moments-SOS) - qui permet en principe d'approcher la valeur optimale avec une précision arbitraire. Le travail contenu dans cette thèse adresse deux facettes concernants le PGM et la hiérarchie moments-SOS: Une première facette concerne l'évolution des relaxations SDP pour le PGM. Le degré des poids SOS dans la hiérarchie moments-SOS augmente avec l'ordre de relaxation. Lorsque le nombre de variables n'est pas modeste, on obtient rapidement des programmes SDP de taille trop grande pour les logiciels de programmation SDP actuels, sauf si l'on peut utiliser des symétries ou une parcimonie structurée souvent présente dans beaucoup d'applications de grande taille. On présente donc un nouveau certificat de positivité sur un compact semi-algébrique qui (i) exploite la parcimonie présente dans sa description, et (ii) dont les polynômes SOS ont un degré borné à l'avance. Grâce à ce nouveau certificat on peut définir une nouvelle hiérarchie de relaxations SDP pour le PGM qui exploite la parcimonie et évite l'explosion de la taille des matrices semidéfinies positives liée au degré des poids SOS dans la hiérarchie standard. Une deuxième facette concerne (i) la modélisation de nouvelles applications comme une instance particulière du PGM, et (ii) l'application de la méthodologie moments-SOS pour leur résolution. En particulier on propose des approximations déterministes de contraintes probabilistes, un problème difficile car le domaine des solutions admissibles associées est souvent non-convexe et même parfois non connecté. Dans notre approche moments-SOS le domaine admissible est remplacé par un ensemble plus petit qui est le sous-niveau d'un polynôme dont le vecteur des coefficients est une solution optimale d'un certain SDP. La qualité de l'approximation (interne) croît avec le degré du polynôme et la taille du SDP. On illustre cette approche dans le problème du calcul du flux de puissance optimal dans les réseaux d'énergie, une application stratégique où la prise en compte des contraintes probabilistes devient de plus en plus cruciale (e.g., pour modéliser l'incertitude liée á l'énergie éolienne et solaire). En outre on propose une extension des cette procedure qui est robuste à l'incertitude sur la distribution sous-jacente. Des garanties de convergence sont fournies. Une deuxième contribution concerne l'application de la méthodologie moments-SOS pour l'approximation de solutions généralisés en commande optimale. Elle permet de capturer le comportement limite d'une suite minimisante de commandes et de la suite de trajectoires associée. On peut traiter ainsi le cas de phénomènes simultanés de concentrations de la commande et de discontinuités de la trajectoire. Une troisième contribution concerne le calcul de solutions mesures pour les lois de conservation hyperboliques scalaires dont l'exemple typique est l'équation de Burgers. Cette classe d'EDP non linéaire peut avoir des solutions discontinues difficiles à approximer numériquement avec précision. Sous certaines hypothèses, la solution mesurepeut être identifiée avec la solution classique (faible) à la loi de conservation. Notre approche moment-SOS fournit alors une méthode alternative pour approcher des solutions qui contrairement aux méthodes existantes évite une discrétisation du domaine. / The generalized moment problem (GMP) is a linear optimization problem over spaces of measures. It allows to model many challenging mathematical problems. While in general it is impossible to solve the GMP, in the case where all data are polynomial and semialgebraic sets, one can define a hierarchy of semidefinite relaxations - the moment-sums-of-squares (moment-SOS) hierachy - which in principle allows to approximate the optimal value of the GMP to arbitrary precision. The work presented in this thesis addresses two facets concerning the GMP and the moment-SOS hierarchy: One facet is concerned with the scalability of relaxations for the GMP. The degree of the SOS weights in the moment-SOS hierarchy grows when augmenting the relaxation order. When the number of variables is not small, this leads quickly to semidefinite programs (SDPs) that are out of range for state of the art SDP solvers, unless one can use symmetries or some structured sparsity which is typically present in large scale applications. We provide a new certificate of positivity which (i) is able to exploit the structured sparsity and (ii) only involves SOS polynomials of fixed degree. From this, one can define a new hierarchy of SDP relaxations for the GMP which can take into account sparsity and at the same time prevents from explosion of the size of SDP variables related to the increasing degree of the SOS weights in the standard hierarchy. The second facet focusses on (i) modelling challenging problems as a particular instance of the GMP and (ii) solving these problems by applying the moment-SOS hierarchy. In particular we propose deterministic approximations of chance constraints a difficult problem as the associated set of feasible solutions is typically non-convex and sometimes not even connected. In our approach we replace this set by a (smaller) sub-level-set of a polynomial whose vector of coefficients is a by-product of the moment-SOS hierarchy when modeling the problem as an instance of the GMP. The quality of this inner approximation improves when increasing the degree of the SDP relaxation and asymptotic convergence is guaranteed. The procedure is illustrated by approximating the feasible set of an instance of the chance-constrained AC Optimal Power Flow problem (a nonlinear problem in the management of energy networks) which nowadays becomes more and more important as we rely increasingly on uncertain energy sources such as wind and solar power. Furthermore, we propose an extension of this framework to the case where the underlying distribution itself is uncertain and provide guarantees of convergence. Another application of the moment-SOS methodology discussed in this thesis consider measure valued solutions to optimal control problems. We show how this procedure can capture the limit behavior of an optimizing sequence of control and its corresponding sequence of trajectories. In particular we address the case of concentrations of control and discontinuities of the trajectory may occur simultaneously. In a final contribution, we compute measure valued solutions to scalar hyperbolic conservation laws, such as Burgers equation. It is known that this class of nonlinear partial differential equations has potentially discontinuous solutions which are difficult to approximate numerically with accuracy. Under some conditions the measure valued solution can be identified with the classical (weak) solution to the conservation law. In this case our moment-SOS approach provides an alternative numerical scheme to compute solutions which in contrast to existing methods, does not rely on discretization of the domain.

Mediernas snabba utveckling skapar en oförutsägbar arbetsmarknad och den höga konkurrens som råder på området kan bidra till ohälsa och kostnader för samhället. Den ställer också krav på att utbildningar i hög grad måste hålla sig uppdaterade för att matcha den föränderliga omvärlden. Syftet med studien är att undersöka medie- och kommunikationsvetares karriärskapande inför, under och efter examen mot de kulturella näringarna. Utifrån The Chaos Theory of Careers används begreppen strange attractor, point attractor, locus of control och phase shift som analysverktyg. Vidare används begreppen Yrkesidentitet och Socialt Kapital. Studien utgår från intervjuer med sju medie- och kommunikationsvetare.Resultatet visar att det krävs särskilda färdigheter för att konstruktivt förhålla sig till en osäker och rörlig framtid. Flera sådana används redan i olika grad omedvetet i studenternas karriärskapande. Vid sidan av att lära sig nya färdigheter behöver medvetenhet om de färdigheter som redan används utvecklas. Undersökningen visar att studenter är beredda att genom ideellt arbete ”köpa” socialt kapital för att göra sig anställningsbara. Det sociala kapitalet riskerar att gå förlorat vid en flytt, vilket talar för att fler globala samarbeten behövs. Ett större fokus på mentorskap och handledning från näringslivet är gynnsamt för både utbildning och näringsliv. Två sammanvävda faktorer är avgörande i karriärskapandet; yrkesidentitet och socialt kapital. Samarbeten mellan studievägledarstudenter och studenter inom medie- och kommunikation kan bidra till båda gruppernas utveckling. Berättande i sig kan också användas för att få syn på karriärskapande färdigheter som redan används. / Media's rapid development creates an unpredictable labour market for media and communication scientists. The competition within the work area can lead to stress and illness, which in turn leads to high costs for society. The aim of this survey is to investigate media- and communication scientists’ creation of a career before, during and after graduation. The survey is based on the following question: How have media and communication scientists created their career before, during and after a general bachelor of media and communication studies? The concepts of strange attractor, point attractor, locus of control and phase shift (from The Chaos Theory of Careers) have been used as analytic tools. Along with this, the concepts of career identity and social capital have been used. The survey is based on interviews with seven media and communication scientists.The result shows that it requires special skills to respond constructively to an uncertain future. Some of these skills are apparent, however, without the students being aware of the influence the skills have in their career building. Besides learning new skills, awareness of the skills individuals already have, is needed. The survey also shows that students work for free to gain social capital. Therefore, a greater focus from the labour market on mentoring and coaching is desirable. The social capital, connected to the original region of education, is likely to be lost for students who move to a different location. Consequently, the development of a more global cooperation between education and labour market is needed. Two interacting factors are decisive in the career creation. These are career identity and social capital. Collaborations between career counsellor students and media and communication students, may also contribute to the development of both groups. The survey has also revealed that students describing their process of creating a career can be used as a tool to help students discover career creation skills that they already use.

<div>Stochastic programs are standard models for decision-making under uncertainty and have been extensively studied in the operations research literature. In general, stochastic programming involves minimizing an expected cost function, where the expectation is with respect to fully specified stochastic models that quantify the aleatoric or `inherent' uncertainty in the decision-making problem. In practice, however, the stochastic models are unknown but can be estimated from data, introducing an additional epistemic uncertainty into the decision-making problem. The Bayesian framework provides a coherent way to quantify the epistemic uncertainty through the posterior distribution by combining prior beliefs of the decision-makers with the observed data. Bayesian methods have been used for data-driven decision-making in various applications such as inventory management, portfolio design, machine learning, optimal scheduling, and staffing, etc.</div><div> </div><div>Bayesian methods are challenging to implement, mainly due to the fact that the posterior is computationally intractable, necessitating the computation of approximate posteriors. Broadly speaking, there are two methods in the literature implementing approximate posterior inference. First are sampling-based methods such as Markov Chain Monte Carlo. Sampling-based methods are theoretically well understood, but they suffer from various issues like high variance, poor scalability to high-dimensional problems, and have complex diagnostics. Consequently, we propose to use optimization-based methods collectively known as variational inference (VI) that use information projections to compute an approximation to the posterior. Empirical studies have shown that VI methods are computationally faster and easily scalable to higher-dimensional problems and large datasets. However, the theoretical guarantees of these methods are not well understood. Moreover, VI methods are empirically and theoretically less explored in the decision-theoretic setting.</div><div><br></div><div> In this thesis, we first propose a novel VI framework for risk-sensitive data-driven decision-making, which we call risk-sensitive variational Bayes (RSVB). In RSVB, we jointly compute a risk-sensitive approximation to the `true' posterior and the optimal decision by solving a minimax optimization problem. The RSVB framework includes the naive approach of first computing a VI approximation to the true posterior and then using it in place of the true posterior for decision-making. We show that the RSVB approximate posterior and the corresponding optimal value and decision rules are asymptotically consistent, and we also compute their rate of convergence. We illustrate our theoretical findings in both parametric as well as nonparametric setting with the help of three examples: the single and multi-product newsvendor model and Gaussian process classification. Second, we present the Bayesian joint chance-constrained stochastic program (BJCCP) for modeling decision-making problems with epistemically uncertain constraints. We discover that using VI methods for posterior approximation can ensure the convexity of the feasible set in (BJCCP) unlike any sampling-based methods and thus propose a VI approximation for (BJCCP). We also show that the optimal value computed using the VI approximation of (BJCCP) are statistically consistent. Moreover, we derive the rate of convergence of the optimal value and compute the rate at which a VI approximate solution of (BJCCP) is feasible under the true constraints. We demonstrate the utility of our approach on an optimal staffing problem for an M/M/c queue. Finally, this thesis also contributes to the growing literature in understanding statistical performance of VI methods. In particular, we establish the frequentist consistency of an approximate posterior computed using a well known VI method that computes an approximation to the posterior distribution by minimizing the Renyi divergence from the ‘true’ posterior.</div>

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Thèse numérisée par la Direction des bibliothèques de l'Université de Montréal.

Spontaneous interactions and chance encounters are important for establishing a sense of connection and shared identity for colleagues since they are a natural possibility for informal conversations, but when work is moved from the physical shared offices to digital workplaces it is no longer as easy to run into a colleague by the coffee machine and just chat for a couple of minutes. This thesis examines what factors are needed in order to create a structure where digital spontaneous interactions could happen. To do this, ten interviews were conducted with people who had been working from home during the pandemic of Covid19, examining what structures for communication and socialisation already existed and that were used. The study showed that the social aspects of work had been missing when the work was done from home and not from the office. It also showed that organized social activities was common among the interviewees, but not always successful nor popular. The study found few workplaces that had created structures that could be the start of establishing possibilities for spontaneous interactions and chance encounters. By taking inspiration from those cases, and looking at previous research, the study found three main factors for creating spontaneous interactions. Creating passive awareness of colleagues; finding ways to present availability; and establishing digital communal areas were all important factors for creating spontaneous interactions. / Spontana interaktioner är viktiga för att skapa en sammanhållning och delad identitet mellan kollegor eftersom de ger en naturlig möjlighet för informella konversationer, men när arbetet flyttas från de fysiska kontoren till digitala arbetsplatser är det inte längre lika enkelt att träffa på en kollega i fikarummet och prata en liten stund. Den här uppsatsen undersöker vilka faktorer som krävs för att skapa kommunikationsstrukturer där spontana interaktioner skulle kunna ske. Tio intervjuer genomfördes med personer som hade arbetat hemifrån under Covid19 pandemin, för att undersöka vilka strukturer för kommunikation och socialisering som redan existerade och utnyttjades. Studien visade att de sociala aspekterna av arbetet hade saknats under hemarbetsperioden, samt att organiserade sociala aktiviteter var vanliga men inte nödvändigtvis lyckade eller populära att delta i. Ett tydligt gap mellan behov och tillgång, där några arbetsplatser gjort försök att minska klyfta. Med inspiration från de fallen, i kombination med resultat från tidigare forskning, lyckades studien hitta tre huvudfaktorer som behöver tas i åtanke för att kunna skapa digitala spontana interaktioner. Att skapa passiv medvetenhet för kollegor; hur man presenterar om en kollega är tillgänglig för kommunikation; och att skapa gemensamma utrymmen är viktigt för att ge möjlighet till spontana interaktioner.

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