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Souza, Daniele Goncalves de. "Metodologia de mapeamento para gestão de processos." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2014. http://hdl.handle.net/10183/139426.
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Com o aumento da competição, provocado pela globalização da economia, as organizações estão em uma luta contínua pela sua sobrevivência no mercado. Essa sobrevivência passa obrigatoriamente pela organização de sua gestão, em busca de tornar-se mais competitiva. Um dos pontos principais que fazem as empresas mais competitivas é a gestão de seus processos e o alinhamento deles com seus objetivos estratégicos. A eficiência das empresas está ligada diretamente à eficiência de seus processos, de forma que seu aperfeiçoamento é um dos objetivos fundamentais para qualquer empresa, sendo o tema central deste trabalho. Inicialmente é apresentada uma série de conceitos que demonstram a importância da gestão de processos, detalhando algumas das ferramentas de desenho e notações utilizadas. A seguir, são apresentadas algumas das principais metodologias utilizadas atualmente para o mapeamento de processos, e um quadro comparativo dessas metodologias é elaborado e analisado, verificando-se as principais etapas de cada metodologia e seu principal objetivo. Posteriormente, é feita a proposição de uma nova metodologia de mapeamento de processos, que tem como princípio a implantação de melhorias na medida em que elas são detectadas durante o mapeamento, fazendo com que as empresas obtenham resultados mais rápidos. A metodologia proposta difere fundamentalmente das metodologias usuais pelo fato destas só implementarem as melhorias depois de realizado todo o processo de mapeamento, o que torna a obtenção de resultados muito demorada.With the increase of competition, caused by the economy globalization, the organizations are in a continuous struggle for their survival in the market. This survival necessarily passes by the organization of its management, aiming to become more competitive. One of the main points that make the companies more competitive is the management of their processes and their alignment with their strategic goals. The efficiency of the companies is directly connected to the efficiency of their processes, so that its improvement is one of the fundamental goals for any company, that being the central theme of this paper. Initially, a series of concepts that show the importance of the process management is introduced, detailing some of the drawing tools and used notations. Following, some of the main methodologies currently used for the process mapping are presented, and a comparative table of theses methodologies is elaborated and analyzed, verifying the main steps of each one and their main goal. Subsequently, the proposition of a new methodology for process mapping is made, whose principle is the implantation of improvement as they are detected during the mapping, leading the companies to obtain faster results. The proposed methodology essentially differs from the usual methodologies because these ones just implement the improvements after all the mapping process is made, which takes a long time for the achievement of results.
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Furloni, Walter. "Controle em horizonte finito com restriçoes de sistemas lineares discretos com saltos markovianos." [s.n.], 2009. http://repositorio.unicamp.br/jspui/handle/REPOSIP/259271.
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Orientador: João Bosco Ribeiro do ValDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e de Computação
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Resumo: O objetivo deste trabalho é propor e resolver o problema de controle em horizonte finito com restrições de Sistemas Lineares Discretos com Saltos Markovianos (SLDSM) na presença de ruído. As restrições dos vetores de estado e de controle não são rígidas e são estabelecidas por valores limites dos seus respectivos primeiro e segundo momentos. O controlador baseia-se numa estrutura de realimentação linear de estados, devendo minimizar uma função custo quadrática. Consideram-se duas situações com respeito à informação disponível da cadeia de Markov associada: num primeiro caso o estado da cadeia de Markov é conhecido em cada instante e num segundo caso dispõe-se apenas de sua distribuição probabilística inicial. Uma formulação determinística do problema estocástico é desenvolvida de modo que as condições necessárias de otimalidade propostas e as restrições possam ser facilmente incluídas utilizando-se desigualdades matriciais lineares (do inglês, Linear Matrix Inequalities - LMI). A inclusão de restrições constitui a principal contribuição, uma vez que elas são pertinentes a vários campos de aplicação tais como indústria química, transporte de massa, economia, etc. Para ilustração do método são apresentadas duas aplicações: uma referente à regulação de tráfego em linhas metroviárias e outra referente ao problema de seleção de ativos de portfólios em aplicações financeiras
Abstract: The purpose of this work is to propose and solve the constrained control problem within a finite horizon of Markovian Jump Discrete Linear Systems (MJDLS) driven by noise. The constraints of the state and control vectors are not rigid and limits are established respectively to their first and second moments. The controller is based on a linear state feedback structure and shall minimize a quadratic cost function. Two cases regarding the available information of the Markovian chain states are considered: firstly the Markov chain states are known at each step and secondly only its initial probability distribution is available. A deterministic formulation to the stochastic problem is developped in order that the proposed necessary optimality conditions and the constraints are easily included by using Linear Matrix Inequalities (LMI). The constraints consideration constitutes the main contribution, since they are pertinent to several application fields as for example chemical industry, mass transportation, economy etc. Two applications are presented for ilustration: one refers to metro lines traffic regulation and another refers to the financial investment income control
Mestrado
Automação
Mestre em Engenharia Elétrica
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Catalão, André Borges [UNESP]. "Modelagem estocástica de opções de câmbio no Brasil: aplicação de transformada rápida de Fourier e expansão assintótica ao modelo de Heston." Universidade Estadual Paulista (UNESP), 2010. http://hdl.handle.net/11449/88592.
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catalao_ab_me_ift.pdf: 811288 bytes, checksum: d4e34c59801bd92233bc9f26884a19ab (MD5)Neste trabalho estudamos a calibração de opções de câmbio no mercado brasileiro utilizando o processo estocástico proposto por Heston [Heston, 1993], como uma alternativa ao modelo de apreçamento de Black e Scholes [Black e Scholes,1973], onde as volatilidades implícitas de opções para diferentes preços de exercícios e prazos são incorporadas ad hoc. Comparamos dois métodos de apreçamento: o método de Carr e Madan [Carr e Madan, 1999], que emprega transfomada rápida de Fourier e função característica, e expansão assintótica para baixos valores de volatilidade da variância. Com a nalidade de analisar o domínio de aplicabilidade deste método, selecionamos períodos de alta volatilidade no mercado, correspondente à crise subprime de 2008, e baixa volatilidade, correspondente ao período subsequente. Adicionalmente, estudamos a incorporação de swaps de variância para melhorar a calibração do modelo
In this work we study the calibration of forex call options in the Brazilian market using the stochastic process proposed by Heston [Heston, 1993], as an alternative to the Black and Scholes [Black e Scholes,1973] pricing model, in which the implied option volatilities related to di erent strikes and maturities are incorporated in an ad hoc manner. We compare two pricing methods: one from Carr and Madan [Carr e Madan, 1999], which uses fast Fourier transform and characteristic function, and asymptotic expantion for low values of the volatility of variance. To analyze the applicability of this method, we select periods of high volatility in the market, related to the subprime crisis of 2008, and of low volatility, correspondent to the following period. In addition, we study the use of variance swaps to improve the calibration of the model
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Bartholme, Carine. "Self-similarity and exponential functionals of Lévy processes." Doctoral thesis, Universite Libre de Bruxelles, 2014. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/209256.
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La présente thèse couvre deux principaux thèmes de recherche qui seront présentés dans deux parties et précédés par un prolegomenon commun. Dans ce dernier nous introduisons les concepts essentiels et nous exploitons aussi le lien entre les deux parties.Dans la première partie, le principal objet d’intérêt est la soi-disant fonctionnelle exponentielle de processus de Lévy. La loi de cette variable aléatoire joue un rôle primordial dans de nombreux domaines divers tant sur le plan théorique que dans des domaines appliqués. Doney dérive une factorisation de la loi arc-sinus en termes de suprema de processus stables indépendants et de même index. Une factorisation similaire de la loi arc-sinus en termes de derniers temps de passage au niveau 1 de processus de Bessel peut aussi être établie en utilisant un résultat dû à Getoor. Des factorisations semblables d’une variable de Pareto en termes des mêmes objets peut également être obtenue. Le but de cette partie est de donner une preuve unifiée et une généralisation de ces factorisations qui semblent n’avoir aucun lien à première vue. Même s’il semble n’y avoir aucune connexion entre le supremum d’un processus stable et le dernier temps de passage d’un processus de Bessel, il peut être montré que ces variables aleatoires sont liées à des fonctionnelles exponentielles de processus de Lévy spécifiques. Notre contribution principale dans cette partie et aussi au niveau de caractérisations de la loi de la fonctionnelle exponentielle sont des factorisations de la loi arc-sinus et de variables de Pareto généralisées. Notre preuve s’appuie sur une factorisation de Wiener-Hopf récente de Patie et Savov.
Dans la deuxième partie, motivée par le fait que la dérivée fractionnaire de Caputo et d’autres opérateurs fractionnaires classiques coïncident avec le générateur de processus de Markov auto-similaires positifs particuliers, nous introduisons des opérateurs généralisés de Caputo et nous étudions certaines propriétés. Nous nous intéressons particulièrement aux conditions sous lesquelles ces opérateurs coïncident avec les générateurs infinitésimaux de processus de Markov auto-similaires positifs généraux. Dans ce cas, nous étudions les fonctions invariantes de ces opérateurs qui admettent une représentation en termes de séries entières. Nous précisons que cette classe de fonctions contient les fonctions de Bessel modifiées, les fonctions de Mittag-Leffler ainsi que plusieurs fonctions hypergéométriques. Nous proposons une étude unifiant et en profondeur de cette classe de fonctions.
Doctorat en Sciences
info:eu-repo/semantics/nonPublished
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Crommentuijn, Léon Emanuel Maria. "Regional household differentials structures and processes = Regionale huishoudensverschillen : structuren en processen /." Amsterdam : Thesis Publishers, 1997. http://catalog.hathitrust.org/api/volumes/oclc/37633887.html.
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Hill, Emma. "Interfacial processes." Thesis, University of Oxford, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.300056.
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Aixill, W. Joanne. "Electrode processes." Thesis, University of Oxford, 1998. http://ora.ox.ac.uk/objects/uuid:9578fd22-42fe-41cc-9d92-96f8272956d8.
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The work presented in this thesis first characterises a high speed channel flow cell and then applies the system to the electro-reduction of nitromethane in aqueous solution. Potential step transient measurements are carried out with the current-time transients simulated using a model based on the absence of axial diffusion. The excellent agreement between theory and experiment confirms the proposed mass transport model and further demonstrates that the combination of current-time transients recorded using the high speed channel flow cell and numerical simulations provide a powerful tool to access homogeneous rate constants of the order 1 x 106s̄¹. The high speed channel flow cell is then used in combination with a range of complementary electrochemical techniques, numerical modelling, in-situ ESR, single crystal experiments and kinetic isotope measurements to infer a mechanistic scheme for the complex electro-reduction pathway of nitromethane in aqueous solution. Platinum, gold, mercury/copper and mercury/gold electrodes are investigated enabling the most conclusive description of the reduction mechanism to date. The reaction pathway is shown to follow an ECEEE type process with the chemical step proceeding at the electrode surface. The heterogeneous rate constant, khet, describing the chemical step is calculated for each electrode surface. For platinum in the pH range 7.0 - 9.0 this value is 0.3 ± 0.06 cm s̄¹. For mercury/copper it is 0.18 cm s̄¹, for gold/mercury it is 0.06 cm s̄¹ and for Au it is 0.095 cm s̄¹. Consideration of these values shows a surprising independence of the heterogeneous rate constant on the chemical identity of the surface with all of the values being similar to within less than an order of magnitude. The reason for the apparent paradox of the observed surface indifference of the chemical reaction step is explained by a homogeneous H transfer from the carbon to the oxygen of the nitromethane radical anion, formed form the initial electron transfer step, occurring in the layer of solution immediately adjacent to the electrode solution as shown in the scheme below. The resulting species, •CH2 N(OH))ˉ then undergoes a rapid irreversible adsorption to the electrode surface and subsequent transformation to the final product the hydroxylamine, CH3NHOH. It is proposed that if the energy barrier to the adsorption of •CH2 N(OH))ˉ is less than that required for the H atom transfer then the reaction rate will be insensitive to the adsorption step and hence the chemical identity of the electrode. This introduces the concept of a whole new electrochemical process: the surface indifferent electrocatalytic reaction.
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De, Oliveira Salazar Ribeiro Pedro Fernando. "Angelic processes." Thesis, University of York, 2014. http://etheses.whiterose.ac.uk/9020/.
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In the formal modelling of systems, demonic and angelic nondeterminism play fundamental roles as abstraction mechanisms. The angelic nature of a choice pertains to the property of avoiding failure whenever possible. As a concept, angelic choice first appeared in automata theory and Turing machines, where it can be implemented via backtracking. It has traditionally been studied in the refinement calculus, and has proved to be useful in a variety of applications and refinement techniques. Recently it has been studied within relational, multirelational and higher-order models. It has been employed for modelling user interactions, game-like scenarios, theorem proving tactics, constraint satisfaction problems and control systems. When the formal modelling of state-rich reactive systems is considered, it only seems natural that both types of nondeterministic choice should be considered. However, despite several treatments of angelic nondeterminism in the context of process algebras, namely Communicating Sequential Processes, the counterpart to the angelic choice of the refinement calculus has been elusive. In this thesis, we develop a semantics in the relational setting of Hoare and He's Unifying Theories of Programming that enables the characterisation of angelic nondeterminism in CSP. Since CSP processes are given semantics in the UTP via designs, that is, pre and postcondition pairs, we first introduce a theory of angelic designs, and an isomorphic multirelational model, that is suitable for characterising processes. We then develop a theory of reactive angelic designs by enforcing the healthiness conditions of CSP. Finally, by introducing a notion of divergence that can undo the history of events, we obtain a model where angelic choice avoids divergence. This lays the foundation for a process algebra with both nondeterministic constructs, where existing and novel abstract modelling approaches can be considered. The UTP basis of our work makes it applicable in the wider context of reactive systems.
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Jalili, Lemar. "Creative Processes." Thesis, Luleå tekniska universitet, Institutionen för konst, kommunikation och lärande, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-75298.
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Pinheiro, Maicon Aparecido. "Processos pontuais no modelo de Guiol-Machado-Schinazi de sobrevivência de espécies." Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/45/45133/tde-01062016-191528/.
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Recentemente, Guiol, Machado e Schinazi propuseram um modelo estocástico para a evolução de espécies. Nesse modelo, as intensidades de nascimentos de novas espécies e de ocorrências de extinções são invariantes ao longo do tempo. Ademais, no instante de nascimento de uma nova espécie, a mesma é rotulada com um número aleatório gerado de uma distribuição absolutamente contínua. Toda vez que ocorre uma extinção, apenas uma espécie morre - a com o menor número vinculado. Quando a intensidade com que surgem novas espécies é maior que a com que ocorrem extinções, existe um valor crítico f_c tal que todas as espécies rotuladas com números menores que f_c morrerão quase certamente depois de um tempo aleatório finito, e as rotuladas com números maiores que f_c terão probabilidades positivas de se tornarem perpétuas. No entanto, espécies menos aptas continuam a aparecer durante o processo evolutivo e não há a garantia do surgimento de uma espécie imortal. Consideramos um caso particular do modelo de Guiol, Machado e Schinazi e abordamos estes dois últimos pontos. Caracterizamos o processo pontual limite vinculado às espécies na fase subcrítica do modelo e discorremos sobre a existência de espécies imortais.Recently, Guiol, Machado and Schinazi proposed a stochastic model for species evolution. In this model, births and deaths of species occur with intensities invariant over time. Moreover, at the time of birth of a new species, it is labeled with a random number sampled from an absolutely continuous distribution. Each time there is an extinction event, exactly one existing species disappears: that with the smallest number. When the birth rate is greater than the extinction rate, there is a critical value f_c such that all species that come with number less than f_c will almost certainly die after a finite random time, and those with numbers higher than f_c survive forever with positive probability. However, less suitable species continue to appear during the evolutionary process and there is no guarantee the emergence of an immortal species. We consider a particular case of Guiol, Machado and Schinazi model and approach these last two points. We characterize the limit point process linked to species in the subcritical phase of the model and discuss the existence of immortal species.
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Kvarnström, Björn. "Traceability in continuous processes : applied to ore refinement processes." Doctoral thesis, Luleå, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-26677.
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Introduction and purpose: Traceability is central for the identification of the root cause(s) behind a product deviation and thus to achieve a product and process quality that is both high and even. Continuous processes contain several characteristics complicating traceability which are not usually discussed in the scientific literature. The overall purpose of this thesis is to provide a theoretical framework for traceability and to test and develop methods for traceability in continuous processes. Design/methodology/approach: A literature review and interviews with engineers in continuous processes were performed in order to identify existing traceability theories and applications as well as characteristics complicating traceability in continuous processes. In addition, experiments evaluating traceability applications in three continuous processes were conducted at the Swedish iron ore refinement company Loussavaara Kiirunavaara AB (LKAB). Radio Frequency Identification (RFID), chemical tracer, and ideal flow simulations were, for example, used within the studied applications.Findings: A theoretical framework for traceability in continuous processes is outlined based on existing scientific literature. Several traceability methods suitable for continuous processes are described and illustrated within the framework. Furthermore, the complicating characteristics in continuous processes that each method may deal with are described. This thesis also presents and illustrates how traceability may be achieved in three continuous processes operating within ore refinement industries.Research limitations/implications: The presented research gives an insight into traceability theory and more specifically into traceability problems in continuous processes. However, the empirical results from the experiments are based on three specific processes, and research in other processes should be performed to validate the results.Practical implications: The presented results illustrate how to increase the ability to trace, track, and predict the product location in processes where traceability previously has been difficult.Originality/value: Prior research has primarily focused on discontinuous processes. By contrast, this thesis presents traceability from a continuous process perspective as well as the design and development of traceability applications for three of these processes.Introduktion och syfte: Spårbarhet är centralt för identifiering av rotorsaken(erna) bakom en produktavvikelse och därmed förmågan att uppnå en hög och jämn produkt- och processkvalitet. Kontinuerliga processer inrymmer ett flertal egenskaper som försvårar spårbarhet och som vanligtvis inte diskuteras i den vetenskapliga litteraturen. Det övergripande syftet med denna avhandling är att utveckla en teoretisk referensram för spårbarhet och att testa samt utveckla metoder för spårbarhet i kontinuerliga processer. Design/metod/forskningsansats: En litteraturstudie samt intervjuer med ingenjörer i kontinuerliga processer genomfördes i syfte att kartlägga befintliga spårbarhetsteorier och tillämpningar samt egenskaper som komplicerar spårbarhet i kontinuerliga processer. Dessutom utfördes experiment för att utvärdera spårbarhetsapplikationer i tre kontinuerliga processer inom det svenska järnmalmsförädlingsföretaget Loussavaara Kiirunavaara AB (LKAB). Radio Frequency Identification (RFID), kemiska spårämne och ideal flödessimuleringar är exempel på metoder som användas inom de studerade applikationerna.Resultat: En teoretisk referensram för spårbarhet i kontinuerliga processer baserad på befintlig forskningslitteratur har utvecklats. Flera spårbarhetsmetoder lämpliga för kontinuerliga processer beskrivs och illustreras inom den framtagna referensramen. Vidare beskrivs vilka komplicerande egenskaper i kontinuerliga processer som varje metod kan hantera. Denna avhandling presenterar och visar också hur spårbarhet kan uppnås i tre kontinuerliga processer som återfinns inom malmförädlingsindustrier.Forskningsbegränsningar/konsekvenser: Den presenterade forskning ger en inblick i spårbarhetsteorier och mer specifikt den spårbarhetsproblematik som återfinns i kontinuerliga processer. De empiriska resultaten från experimenten bygger dock på tre specifika processer, och fortsatt forskning kan med fördel utföras i andra processer för att validera resultaten.Praktiska konsekvenser: De presenterade resultaten visar hur man kan öka möjligheten att spåra, följa och prediktera en produkts position i processer där spårbarhet tidigare varit komplicerat.Originalitet/forskningsvärde: Tidigare forskning har främst fokuserat på diskontinuerliga processer. Denna avhandling presenterar dock spårbarhet utifrån ett kontinuerligt processperspektiv samt utvecklar och skapar spårbarhetsapplikationer för tre kontinuerliga processer.
Godkänd; 2010; 20101020 (bjokva); DISPUTATION Ämnesområde: Kvalitetsteknik/Quality Technology & Management Opponent: Professor Josse De Baerdemaeker, Katholieke Universiteit Leuven, Belgium Ordförande: Professor Bjarne Bergquist, Luleå tekniska universitet Tid: Onsdag den 24 november 2010, kl 13.00 Plats: D770, Luleå tekniska universitet
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Vaillancourt, Jean Carleton University Dissertation Mathematics. "Interacting Fleming-Viot processes and related measure-valued processes." Ottawa, 1987.
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Peixoto, Gabriel Ribeiro da Cruz. "O processo K em uma árvore de profundidade infinita." Universidade de São Paulo, 2014. http://www.teses.usp.br/teses/disponiveis/45/45133/tde-28012015-010059/.
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Nesse trabalho introduzimos o Processo K em árvores de profundidade infinita. Estes são processos estocásticos em tempo contínuo que têm $\\widebar{\\sN}_*^{\\sN_*}$ como espaço de estados. O principal resultado desse trabalho consiste em mostrar que, sob condições adequadas, o processo título pode ser obtido como limite de Processos K em árvores de profundidade finita, estudados em Fontes et at. (2014), quando a profundidade delas cresce para o infinito.We introduce the K-Process on trees with infinite depth. These are stochastic processes in continuous time, having state space $\\widebar{\\sN}_*^{\\sN_*}$. As the main result from this thesis, we prove that, under adequate assumptions, the title process can be obtained as the limit of K-Process on trees with finite depth, studied in Fontes et al. (2014), as the depth of the tree grows to infinity.
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Lai, Sau Man. "Feasibility and flexibility in chemical process design /." View abstract or full-text, 2009. http://library.ust.hk/cgi/db/thesis.pl?CBME%202009%20LAI.
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Veillette, Mark S. "Study of Gaussian processes, Lévy processes and infinitely divisible distributions." Thesis, Boston University, 2011. https://hdl.handle.net/2144/38109.
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Thesis (Ph.D.)--Boston UniversityPLEASE NOTE: Boston University Libraries did not receive an Authorization To Manage form for this thesis or dissertation. It is therefore not openly accessible, though it may be available by request. If you are the author or principal advisor of this work and would like to request open access for it, please contact us at open-help@bu.edu. Thank you.
In this thesis, we study distribution functions and distributional-related quantities for various stochastic processes and probability distributions, including Gaussian processes, inverse Levy subordinators, Poisson stochastic integrals, non-negative infinitely divisible distributions and the Rosenblatt distribution. We obtain analytical results for each case, and in instances where no closed form exists for the distribution, we provide numerical solutions. We mainly use two methods to analyze such distributions. In some cases, we characterize distribution functions by viewing them as solutions to differential equations. These are used to obtain moments and distributions functions of the underlying random variables. In other cases, we obtain results using inversion of Laplace or Fourier transforms. These methods include the Post-Widder inversion formula for Laplace transforms, and Edgeworth approximations. In Chapter 1, we consider differential equations related to Gaussian processes. It is well known that the heat equation together with appropriate initial conditions characterize the marginal distribution of Brownian motion. We generalize this connection to finite dimensional distributions of arbitrary Gaussian processes. In Chapter 2, we study the inverses of Levy subordinators. These processes are non-Markovian and their finite-dimensional distributions are not known in closed form. We derive a differential equation related to these processes and use it to find an expression for joint moments. We compute numerically these joint moments in Chapter 3 and include several examples. Chapter 4 considers Poisson stochastic integrals. We show that the distribution function of these random variables satisfies a Kolmogorov-Feller equation, and we describe the regularity of solutions and numerically solve this equation. Chapter 5 presents a technique for computing the density function or distribution function of any non-negative infinitely divisible distribution based on the Post-Widder method. In Chapter 6, we consider a distribution given by an infinite sum of weighted gamma distributions. We derive the Levy-Khintchine representation and show when the tail of this sum is asymptotically normal. We derive a Berry-Essen bound and Edgeworth expansions for its distribution function. Finally, in Chapter 7 we look at the Rosenblatt distribution, which can be expressed as a infinite sum of weighted chi-squared distributions. We apply the expansions in Chapter 6 to compute its distribution function.
2031-01-01
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Haugomat, Tristan. "Localisation en espace de la propriété de Feller avec application aux processus de type Lévy." Thesis, Rennes 1, 2018. http://www.theses.fr/2018REN1S046/document.
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Dans cette thèse, nous donnons une localisation en espace de la théorie des processus de Feller. Un premier objectif est d’obtenir des résultats simples et précis sur la convergence de processus de Markov. Un second objectif est d’étudier le lien entre les notions de propriété de Feller, problème de martingales et topologie de Skorokhod. Dans un premier temps nous donnons une version localisée de la topologie de Skorokhod. Nous en étudions les notions de compacité et tension. Nous faisons le lien entre les topologies de Skorokhod localisée et non localisée, grâce à la notion de changement de temps. Dans un second temps, à l’aide de la topologie de Skorokhod localisée et du changement de temps, nous étudions les problèmes de martingales. Nous montrons pour des processus l’équivalence entre, d’une part, être solution d’un problème de martingales bien posé, d’autre part, vérifier une version localisée de la propriété de Feller, et enfin, être markovien et continu en loi par rapport à sa condition initiale. Nous caractérisons la convergence en loi pour les solutions de problèmes de martingale en terme de convergence des opérateurs associés et donnons un résultat similaire pour les approximations à temps discret. Pour finir, nous appliquons la théorie des processus localement fellerien à deux exemples. Nous l’appliquons d’abord au processus de type Lévy et obtenons des résultats de convergence pour des processus à temps discret et continu, notamment des méthodes de simulation et schémas d’Euler. Nous appliquons ensuite cette même théorie aux diffusions unidimensionnelles dans des potentiels, nous obtenons des résultats de convergence de diffusions ou marches aléatoires vers des diffusions singulières. Comme conséquences, nous déduisons la convergence de marches aléatoires en milieux aléatoires vers des diffusions en potentiels aléatoiresIn this PhD thesis, we give a space localisation for the theory of Feller processes. A first objective is to obtain simple and precise results on the convergence of Markov processes. A second objective is to study the link between the notions of Feller property, martingale problem and Skorokhod topology. First we give a localised version of the Skorokhod topology. We study the notions of compactness and tightness for this topology. We make the connexion between localised and unlocalised Skorokhod topologies, by using the notion of time change. In a second step, using the localised Skorokhod topology and the time change, we study martingale problems. We show the equivalence between, on the one hand, to be solution of a well-posed martingale problem, on the other hand, to satisfy a localised version of the Feller property, and finally, to be a Markov process weakly continuous with respect to the initial condition. We characterise the weak convergence for solutions of martingale problems in terms of convergence of associated operators and give a similar result for discrete time approximations. Finally, we apply the theory of locally Feller process to some examples. We first apply it to the Lévy-type processes and obtain convergence results for discrete and continuous time processes, including simulation methods and Euler’s schemes. We then apply the same theory to one-dimensional diffusions in a potential and we obtain convergence results of diffusions or random walks towards singular diffusions. As a consequences, we deduce the convergence of random walks in random environment towards diffusions in random potential
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Tessaro, Elias Paulo. "Avaliação de processos oxidativos para o tratamento ambientalmente adequado de fluidos de corte." Universidade de São Paulo, 2008. http://www.teses.usp.br/teses/disponiveis/75/75132/tde-20062008-165020/.
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Durante o processo metalúrgico de usinagem de uma peça ocorre a geração de calor proveniente do atrito ferramenta/peça e cavaco/ferramenta. Para que ocorra uma menor geração de calor possibilitando o manuseio, bem como a minimização na deformação da peça, utilizam-se fluidos, que são soluções lubrificantes à base de óleos, água ou polímeros, podendo ser sintéticos ou não, diminuindo, assim, o coeficiente de atrito reduzindo-se a quantidade de calor gerado no processo. Há uma grande variedade de fluidos de corte disponíveis no mercado que são constituídos por diversos compostos como: aminas, compostos clorados e/ou aromáticos, glicóis, nitrosaminas além da presença de metais provenientes do processo de manufatura, portanto, sem tratamento, não podem ser lançados na rede de esgoto convencional. Atualmente não há um método de tratamento para os fluidos de corte nas indústrias. Nesse contexto, propõe-se um estudo sobre a viabilidade dos tipos de tratamento dos fluidos de corte para uma disposição adequada. Os processos de tratamento propostos neste trabalho compreendem hidrolise ácida e Processo Oxidativo Avançado (POA), mais especificamente, Sistema Fenton, além de propor um tratamento baseado na fotodegradação. A caracterização do fluido antes e após seu tratamento foi realizada por técnicas analíticas e espectrométricas. Os processos oxidativos mostraram-se satisfatórios para o tratamento dos efluentes, reduzindo os níveis de contaminantes aos permitidos pela legislação. O processo foto-Fenton mostrou-se mais eficiente que o processo Fenton na degradação de todos os parâmetros avaliados, incluindo BTEX e HPAs. Os processos de hidrólise ácida não apresentaram resultados satisfatórios, reduzindo apenas os metais aos níveis permitidos para descarte.During the cutting process, part of the heat generation results from tool-part and chip-tool friction. So that it happens a smaller generation of heat making possible the handling, as well as minimization in the tool deformation, cutting fluids are used, that are the oils base, water or polymeric lubricating solutions, could be synthetic or no, decreasing the attrition coefficient being reduced the amount of heat generated in the process. There is a great variety of cutting fluids that are constituted for several composed as: amines, chlorinated and/or aromatic composed, glycols and nitrosamines besides the presence of metals proceeding of manufacture process, therefore, without a treatment, they cannot be discarded in the conventional sewerage system. At the moment there isn\'t a treatment method for the cut fluids in the industries. In that context, intends a study about the viability types of cutting fluids treatment for appropriate disposition. Treatment processes proposed in this work understand acid hydrolysis and Advanced Oxidative Process (AOP), more specifically, Fenton System, in addition proposing a treatment based on the photodegradation (photo-Fenton process). The characterization of fluid before and after treatment it was accomplished by analytical and spectrometry techniques. Oxidative processes were exposed satisfactory for cutting fluids treatment, reducing the levels of pollutants to the allowed by the legislation. Photo-Fenton process was shown more efficient than Fenton process in the oxidation of BTEX and PAHs. Acid hydrolysis processes didn\'t present satisfactory results, just reducing the metals at the levels allowed for discard.
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Brignoni, Jimmy. "Modelling transfer processes /." [S.l.] : [s.n.], 2009. http://www.ub.unibe.ch/content/bibliotheken_sammlungen/sondersammlungen/dissen_bestellformular/index_ger.html.
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Desharnais, Josée. "Labelled Markov processes." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape3/PQDD_0031/NQ64546.pdf.
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Balan, Raluca M. "Set-Markov processes." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/NQ66119.pdf.
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Gohm, Rolf. "Noncommutative stationary processes /." Berlin [u.a.] : Springer, 2004. http://www.loc.gov/catdir/enhancements/fy0813/2004103932-d.html.
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Eltannir, Akram A. "Markov interactive processes." Diss., Georgia Institute of Technology, 1993. http://hdl.handle.net/1853/30745.
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Seidel, Karen. "Probabilistic communicating processes." Thesis, University of Oxford, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.306194.
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Makai, Tamas. "Random graph processes." Thesis, Royal Holloway, University of London, 2012. http://repository.royalholloway.ac.uk/items/b24b89af-3fc1-4d2f-a673-64483a3bc2f2/8/.
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This thesis deals with random graph processes. More precisely it deals with two random graph processes which create H -free graphs. The first of these processes is the random H-elimination process which starts from the complete graph and in every step removes an edge uniformly at random from the set of edges which are found in a copy of H. The second is the H-free random graph process which starts from the empty graph and in every step an edge chosen uniformly at random from the set of edges which when added to the graph would not create a copy of H is inserted. We consider these graph processes for several classes of graphs H, for example strictly two balanced graphs. The class of strictly two balanced graphs includes among others cycles and complete graphs. We analysed the H-elimination process, when H is strictly 2-balanced. For this class we show the typical number of edges found at the end of the process. We also consider the sub graphs created by the process and its independence number. We also managed to show the expected number of edges in the H -elimination pro- cess when H = Ki, the graph created from the complete graph on 4 vertices by removing an edge and when H = K34 where K34 is created from the complete bi- partite graph with 3 vertices in one partition and'4 vertices in the second partition, by removing an edge. In case of the H -free process we considered the case when H is the triangle and showed that the triangle-free random graph process only creates sparse subgraphs. Finally we have improved the lower bound on the length of the K34-free random graph process. '
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Walters, K. "Genetic recombination processes." Thesis, University of Sheffield, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.269336.
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Scarr, James Richard Hadley. "Pharmaceutical development processes." Thesis, University College London (University of London), 2008. http://discovery.ucl.ac.uk/1446773/.
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The process of developing pharmaceuticals requires expertise from numerous different scientific areas. Four separate studies have been undertaken on Pharmaceuticals Testing, Process Development, Business Strategy and Process Validation within this industry. New pharmaceuticals generally require multi-step reactions, which increasingly feature the involvement of biological synthesis to improve the optical purity and thus efficacy and safety of the drug. Two of the problems with employing biological synthesis are the high level of inhibition observed and the potential difficulty with which these batch based reactions are combined with semi-continuous chemical synthesis. The first study characterises the inhibition of CHMO, a promising oxygenase enzyme, with the aid of flow cytometry using different systems: o A range of substrates, based around the natural substrate cyclohexanone but with differing ring size and increasing chain length. o Different CHMO catalysed reactions - isolated enzyme, free cell and immobilised whole cell. As expected, reactions with CHMO expressed in E. coli TOP 10 [pQR239] in their immobilised form reduced the observed reaction rate. Unexpectedly, for the more rapidly converted substrates (generally those closest to cyclohexanone), immobilisation was found to increase the inhibition observed. It has been postulated that this is due to an oxygen shortage for maintaining cell metabolism and a time based inhibitory effect. Advantages of immobilised cells are that they can be rapidly removed from the reaction broth allowing greater integration with other processes and can be recycled for multiple re-use. To facilitate their industrial use, the large scale production of immobilised whole cells is required. Whilst immobilised cell reactions are industrially employed, how such large quantities of immobilised cells are produced is yet to be reported. The feasibility of immobilisation of oxygenase expressing cells has been assessed in this first study, using the flow cytometry as a tool for assessing cell damage in the key step of cell separation. Within the pharmaceutical development process drug molecules are rigorously tested in clinical trials. However the metabolites likely to be produced in the body, which may be active (and preferable drug candidates to the parent molecule) or toxic (and thus responsible for the failure of the drug in the final stages of clinical trials) are often ignored. Within the human body the oxygenase enzymes Cytochrome P450s (CYPs) are responsible for the primary metabolism of more than 90% of drugs. The second study assesses different methods of identifying the CYP responsible for metabolism and discusses the importance of being able to produce gram scale quantities of metabolites. This study indicated that the best currently feasible option of CYP identification is the employment of Bactosome (individual CYP enzymes expressed in bacteria) with a selective inhibitor pre-screen. The scientific complexity of the pharmaceutical development process makes effective strategic planning and decision making difficult. Whilst the necessity of business plans to enable companies to secure finance has helped scientists to gain an understanding of their market and associated business risks, business decisions such as when to invest and how much, often rely solely on the company's tolerance of risk, collective intuition and experience. The third study investigates the business strategy of the pharmaceutical development process. StrategyDynamics modelling has been employed to create a living model of a start-up contract research organisation. The model demonstrates the advantages of being able to predict key resource bottlenecks, contrast different business decisions such as growth strategy and plan for future events and changes in technology and markets. This modelling can potentially save companies from expensive trial and error approaches and help to manage risk. Regulatory pressure within the pharmaceutical development industry and the importance of validation is increasing. In the fourth study the application of Process Validation to the areas of pharmaceutical development process in the first three studies are investigated. For CHMO biocatalysis the reproducibility of immobilised experiments was assessed, for drug metabolite production the importance of change validation, i.e. assay robustness, was determined and for the Strategy Dynamics modelling an approach to validating the model has been detailed.
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Hamam, Khaled K. K. "Unconventional dyeing processes." Thesis, University of Manchester, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.602947.
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The cost of energy and present market demand for special dyeing effects have created a situation which has resulted in a number of mechanical innovations designed to change the character of textile dyeing. The present work investigates a novel machinery concept and unconventional continuous dyeing process. The process is accomplished by applying the dye liquor to the fabric using the 'FKO system' (Foster Khaled Oulton). The original concept involves preheating and removal of air from the fabric by saturated and superheated steam under pressure in a continuous manner. After passage through a labyrinth seal, the FKO system heats the ecru fabric using saturated or superheated steam under pressure and the fabric then passes through the dye liquor. When the ecru fabric is presented to the dye liquor, it is hot, swollen and air free. A variety of fabrics have been tested, including cotton, polyester, wool, cotton/polyester and cotton/wool union fabrics. The use of compressed air fed labyrinth seals allows high speed, non-contact expression of surplus liquid. Expression perfonnance is found to be equal to, or better than, that produced by the heaviest available mangle systems and gives more controlled variable expression values. The application of different types of computer feedback control is discussed. Methods for the control of temperature, pH and level parameters of the dye liquor in the FKO system are suggested.
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Wlodarski, Rafael. "Processes of pairbonding." Thesis, University of Oxford, 2014. http://ora.ox.ac.uk/objects/uuid:bc2ba4f3-138a-4512-ab4e-087964b7ff88.
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This thesis expands our understanding of the role of several different mating behaviours in the process of forming and maintaining human mating pair-bonds. Chapter 2 investigated within-sex mating strategies and found that their distribution reflects the presence of two phenotypes, one favouring the pursuit of short-term mating and one the establishment of mating pair-bonds, each driven by prenatal testosterone exposure. Chapter 3 investigated the possible functional role of kissing in mating relationships, and found that it was utilised divergently by individuals pursuing different mating strategies, with those interested in short-term mating utilising it to assess the suitability of potential mates at initial relationship stages, and those interested in long-term mating using it to mediate pair-bond attachments. Chapter 4 examined female attitudes towards kissing across the menstrual cycle and found that attitudes varied with cycle phase, mediated by fluctuations in the hormone progesterone. This chapter also investigated the effects of kissing-related information on mate assessment and found that such information influenced mate desirability, even in the presence of typically dominant visual cues. Lastly, Chapter 5 investigated the cognitive effects of established pair-bonds, finding that individuals ‘in love’ with a mating partner show improved empathising abilities, particularly males when it comes to assessing negative emotional states in others. Using an evolutionary framework, each chapter of this thesis contributes novel insights to our understanding of these diverse behaviours. These results suggest that that future research must take into account within-sex phenotypic differences in order to truly understand human mating strategy decisions, and that different mating strategy phenotypes might adaptively utilise the same courtship behaviours in divergent ways. Furthermore, these results also suggest that pair-bonding in humans may be a relatively recent phenomenon, and that the formation of such pair-bonds can have adaptive cognitive effects for males within such bonded relationships.
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Cheng, Hua. "Intensified electrochemical processes." Thesis, University of Newcastle upon Tyne, 1999. http://hdl.handle.net/10443/3104.
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Process intensification is in principle a strategy of making dramatic reductions in the capital cost of a production system, improving intrinsic safety, reducing environmental impact and energy consumption. An electrochemical cell is a specific example of a multiphase system that should be capable of being operated very intensively within a centrifugal acceleration field. This thesis presents the first systematical research work in this field. It demonstrates that many electrochemical processes can be enhanced considerably by using a high-acceleration field, which takes full advantage of the improvement in catalytic activity and optimal electrode structure. Six electrochemical processes have been investigated. Namely, the electro-reduction of oxygen, electro-oxidations of hydrogen and methanol, chlorine evolution, water electrolysis, and methanol fuel cell reaction. Several catalysed electrodes including Ti mesh or carbon cloth were prepared and used for the above processes. A number of catalyst deposition routes were explored for the preparation of the technical electrodes, including Pt, Ag, Pt-Ru and RuO₂ electrodes. The action of a centrifugal field is two fold: first, it acts as an mass transfer promotor; second, it accelerates gas bubble disengagement For chlorine evolution, water electrolysis, and methanol oxidation, centrifugal fields play a very significant role in and lead to significant reductions in polarisation and mass transport resistance. The high acceleration fields reduce the cell resistance drastically through effectively disengaging gas bubbles from the electrode surface. It also overcomes mass transport limitations in these systems through generation of powerful interphase buoyancy force. The processes were therefore greatly intensified in centrifugal fields and approached a maximum efficiency. Increase in the operating temperature and the concentration also benefit the processes. Interestingly, both effects were intensified in centrifugal fields, i.e., the current density increases more rapidly in centrifugal fields than in stationary cell at a constant potential corresponding to the same increment in temperature and concentration. For the gas consuming systems, e.g., oxygen reduction and hydrogen oxidation, centrifugal fields also produce positive results. The degree of intensification for these systems was limited to a relatively low level. Centrifugal fields have little benefit for methanol fuel cell operation. The results were disappointing and unexpected. It was realised that the cathode process, an oxygen gas consuming reaction, is difficult to be intensified by using centrifugal means due to the type of electrode used at the cathode, although the anode process was intensified in centrifugal fields. A model for a centrifugal cell with gas evolving electrodes was proposed and tested. In the model the cell voltage and cell voltage reduction are obtained from the hydrodynamic electrochemical, and electrochemical engineering theories.
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Costello, Roger Lee. "Responsive sequential processes /." The Ohio State University, 1988. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487588249825353.
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Thompson, James. "Submanifold bridge processes." Thesis, University of Warwick, 2015. http://wrap.warwick.ac.uk/79558/.
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We introduce and study submanifold bridge processes. Our method involves proving a general formula for the integral over a submanifold of the minimal heat kernel on a complete Riemannian manifold. Our formula expresses this object in terms of a stochastic process whose trajectories terminate on the submanifold at a fixed positive time. We study this process and use the formula to derive lower bounds, an asymptotic relation and derivative estimates. Using these results we introduce and characterize Brownian bridges to submanifolds. Before doing so we prove necessary estimates on the Laplacian of the distance function and define a notion of local time on a hypersurface. These preliminary developments also lead to a study of the distance between Brownian motion and a submanifold, in which we prove exponential bounds and concentration inequalities. This work is motivated by the desire to extend the analysis of path and loop space to measures on paths which terminate on a submanifold.
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Taylor, Paul. "Autonomic business processes." Thesis, University of York, 2015. http://etheses.whiterose.ac.uk/11712/.
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Business processes in large organisations are typically poorly understood and complex in structure. Adapting such a business process to changing internal and external conditions requires costly and time consuming investigative work and change management. In contrast autonomic systems are able to adapt to changing environments and continue to function without external intervention. Enabling business processes to adapt to changing conditions in the same way would be extremely valuable. This work investigates the potential to self-heal individual business process executions in generic business processes. Classical and Immune-inspired classification algorithms are tested for their predictive utility with Decision Trees augmented with MetaCost and Immunos 99 exhibiting the best performance respectively. An approach to deriving recovery strategies from historical process data in the absence of a process model is presented and tested for suitability. Also presented is an approach to selecting the best of the determined recovery strategies for application to a business process execution, which is then tested to determine the impact of its parameters on the quality of selected recoveries.
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Brown, Neil Christopher Charles. "Communicating Haskell processes." Thesis, University of Kent, 2011. https://kar.kent.ac.uk/33880/.
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Concurrent programming supports multiple threads of concurrent execution. It is a suitable paradigm for interaction with the outside world, where many inputs (e.g. network packets, key-presses, mouse-clicks) may arrive at any time and need to be dealt with at the same time. Concurrent execution also potentially allows for parallel speed-up; multicore machines are now the standard for new PCs, but the quest to take full advantage of the available parallelism continues. One approach to concurrent programming is process-oriented programming, which uses message-passing and is based on Hoare and Roscoe's Communicating Sequential Processes (CSP). CSP is a process calculus centred on concurrent processes that communicate with each other via synchronous channels. This is used as a formal underpinning for process-oriented programming, either directly (proving behaviours of programs with a CSP model checker) or indirectly (providing sound design principles and patterns). Process-oriented programming has previously been provided in programming languages such as occam-π and libraries for other mainstream languages such as Java and C++. However, as yet process-oriented programming has failed to gain much traction via these implementations; occam-π is rooted in the much older language occam and thus lacks powerful data structures (among other features) which are standard in most modern languages - while languages such as Java and C++, where data is mutable and easily shared, can be an awkward fit to process-oriented programming. Haskell is a functional programming language that is notable for its purity, type-classes, monads and lazy evaluation: modern features that provide interesting and powerful ways to program, including good support for imperative programming. Like other functional languages, it eliminates mutable data - which immediately removes a whole class of problems in concurrent programming. This thesis contends that CSP and process-oriented programming fit well with Haskell. The thesis details the creation of a CSP library for Haskell (Communicating Haskell Processes: CHP) - which features powerful support for process composition - and its further augmentation with capabilities such as support for a new concurrency primitive (conjunction), tracing and the ability to generate formal models of CHP programs. This allows programmers to build concurrent message-passing systems with a strong formal underpinning in a modern programming language, with more features and less complications than process-oriented libraries for other languages.
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Harris, John William. "Branching diffusion processes." Thesis, University of Bath, 2006. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.428379.
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Valmy, Larissa. "Modèles hiérarchiques et processus ponctuels spatio-temporels - Applications en épidémiologie et en sismologie." Phd thesis, Université des Antilles-Guyane, 2012. http://tel.archives-ouvertes.fr/tel-00841146.
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Les processus ponctuels sont souvent utilisés comme modèles de répartitions spatiales ou spatio-temporelles d'occurrences. Dans cette thèse, nous nous intéressons tout d'abord à des processus de Cox dirigés par un processus caché associé à un processus de Dirichlet. Ce modèle correspond à des occurrences cachées influençant l'intensité stochastique des occurrences observées. Nous généralisons la notion de " Shot noise Cox process " introduite par Moller et développons le traitement bayésien par un échantillonneur de Gibbs combiné à un algorithme de Metropolis-Hastings. Nous montrons que cette méthode MCMC est à sauts réversibles. Le modèle prend en compte, en effet, un nombre aléatoire de contributions cachées influençant l'intensité du processus ponctuel observé donc a un espace paramétrique de dimension variable. Nous focalisons l'inférence statistique sur l'estimation de la valeur espérée de chaque contribution cachée, le nombre espéré de contributions cachées, le degré d'influence spatiale de ces contributions et leur degré de corrélation. Le test d'égalité des contributions et celui de leur indépendance sont ainsi développés. L'utilité en épidémiologie et en écologie est alors démontrée à partir de données de Rubus fruticosa, Ibicella lutea et de mortalité dans les cantons de Georgia, USA. En termes de données observées, deux situations sont considérées: premièrement, les positions spatiales des occurrences sont observées entre plusieurs paires de dates consécutives; deuxièmement, des comptages sont effectués, au cours d'une période fixée, dans des unités d'échantillonnage spatiales. D'autre part, nous nous intéressons aux processus ponctuels à mémoire introduits par Kagan, Ogata et Vere-Jones, précurseurs de la statistique sismologique. En effet, les processus ponctuels spatio-temporels ont une place importante dans l'étude des catalogues sismiques puisque ces derniers sont généralement constitués d'événements sismiques datés et géo-référencés. Nous avons étudié un modèle ETAS (Epidemic Type Aftershock Sequence) avec une intensité d'arrière-plan indépendante du temps et plusieurs fonctions déclenchantes permettant d'intégrer les événements antérieurs récents. Cette approche est utilisée pour étudier la sismicité de l'arc des Petites Antilles. Une étude comparative des modèles Gamma, Weibull, Log-Normal et loi d'Omori modifiée pour les fonctions déclenchantes est menée. Nous montrons que la loi d'Omori modifiée ne s'ajuste pas aux données sismiques des Petites Antilles et la fonction déclenchante la plus adaptée est le modèle de Weibull. Cela implique que le temps d'attente entre répliques dans la zone des Petites Antilles est plus faible que celui des régions à sismicité décrite par la loi d'Omori modifiée. Autrement dit, l'agrégation des répliques après un événement majeur est plus prononcée dans la zone des Petites Antilles. La possibilité d'inclure une intensité d'arrière-plan suivant un processus de Dirichlet centré sur un processus spatial log-gaussien est discutée.
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Padley, Mark Andrew. "Incorporating operability measures into the process synthesis stage of design." Phd thesis, Department of Chemical Engineering, 1991. http://hdl.handle.net/2123/5996.
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Hägele, Florian [Verfasser]. "Quality improvement of minimally processed leafy salads using innovative technological processes / Florian Hägele." Aachen : Shaker, 2017. http://d-nb.info/1139583433/34.
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Sabir-Bagag, Aïcha. "Photoionisation et spectrométrie de masse : un nouvel outil pour l'identification de biomolécules." Thesis, Evry-Val d'Essonne, 2008. http://www.theses.fr/2008EVRY0041/document.
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Mon travail de thèse a été entièrement dévoué à l’étude d’une récente technique d’ionisation en spectrométrie de masse : la photoionisation à pression atmosphérique (APPI). Ce travail est développé sur deux axes principaux. D’une part, il vise à appliquer cette méthode d’ionisation à de nouvelles familles de molécules et d’en élargir le cas échéant le domaine d’application. D’autre part et parallèlement à cela, nous nous sommes attachés à l’étude des mécanismes de formation des ions ainsi qu’à l’élucidation des voies de fragmentation. En effet, ces dernières se révèlent souvent intensives et particulières. Les résultats obtenus dans le cadre du premier axe de recherche de ce travail de thèse offrent de nouvelles solutions pour mieux comprendre le comportement de molécules biologiques sous irradiation UV et à pression atmosphérique. En effet, nous avons pu démontrer que la photoionisation à pression atmosphérique pouvait s’étendre à d’autres classes de composés que ceux initialement pressentis et plus particulièrement à des biomolécules polaires et de haut poids moléculaire tels que les acides nucléiques, peptides, les peptides, etc. De plus, ce travail a permis de démontrer l’impact du milieu (solvant) sur le mécanisme de formation des ions sous irradiation UV. Ainsi l’étude et la connaissance des mécanismes fondamentaux de formation des ions en APPI a visé in fine au contrôle de la formation des ions précurseurs et par voie de conséquence, à celui des fragments générés en source. Nous avons observé des ions fragments radicalaires d’un type nouveau, jamais observé auparavant avec les sources d’ions connues L’originalité et le caractère résolument novateur de cette expérience nous ont amené à transférer cette expérience sur une ligne de lumière du Synchrotron SOLEIL. L’utilisation d’une source de lumière accordable en APPI va certainement renforcer la versatilité de cette source d’ionsMy PhD’s work has been completely dedicated to develop new ionization source in mass spectrometry: the atmospheric pressure photoionization (APPI). This work is developed on two main areas. On the one hand, it aims to apply this method to new family of biomolecules. On the other hand, we report a comprehensive study on the ionization mechanisms in APPI. The first part of this manuscript offers a better understanding of the behaviour of the biological molecules under VUV radiation and atmospheric pressure. Indeed, we were able to say that polar and high molecular weight biomolecules could be easily photoionizable. Moreover, this work allows studying the effect of the medium (solvent) on the photoionization mechanism to be studied. It is possible to control the orientation of the observed reactions and to choose a particular type of molecular ion. We observed extensive and peculiar fragmentations which have never been detected with classical ionization techniques. The originality and innovative approach of this experience led us to transfer it to a UV beamline of the Synchrotron SOLEIL. Using an accordable source will certainly enhance the versatility of the ion source
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Rascop, Silvana Borges. "Melhoria da qualidade em uma empresa farmaceutica com base no Modelo de Melhoria e na RDC 210/03." [s.n.], 2006. http://repositorio.unicamp.br/jspui/handle/REPOSIP/264862.
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Orientador: Ademir PetenateDissertação (mestrado profissional) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica
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Resumo: O objetivo deste estudo foi aplicar a utilização o ¿Modelo de Melhoria¿, à gestão de controle em processo, visando a obtenção de qualidade no produto terminado e, posteriormente, implantá-lo em outras linhas de produção. O trabalho foi realizado no setor de revisão de produto final de uma indústria farmacêutica, na atividade de controle em processo. Utilizou-se o Modelo de Melhoria na determinação dos pontos críticos a serem trabalhados e as Normas de Amostragem por Atributos da ABNT para a determinação dos planos de amostragem. O estudo envolveu a avaliação de unidades do produto que já haviam passado pela revisão final e a determinação de itens com defeitos que não tinham sido separados pelo processo de revisão 100% caracterizando, assim, como falha de revisão. A reestruturação do Controle em Processo e o treinamento contínuo dos envolvidos propiciaram a diminuição do número de falhas ao longo do tempo, obtendo-se, com isto, melhoria de qualidade do produto terminado
Abstract: The objective of this study was to show that the use of the ¿Improvement Guide¿ methodology to obtain quality in products. The Improvement Guide Methodology was employed to determine the critical factors to be addressed and the ¿Sampling Rules¿ by attributes in acordance to ABNT (Brazilian Association of Technical Rules) was employed to determine the sampling plans. The study comprised the evaluation of samples that had already gone through the final revision process, thus bringing out defective items that had not been detected by the process, therefore being classified as 100% revision failure. By restructuring the process control and by creating an awareness of the employees envolved in the process, failures decreased through time and the problems were corrected, therefore leading toan improvement in the quality of the products
Mestrado
Gestão da Qualidade Total
Mestre Profissional em Engenharia Mecanica
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Eggersmann, Markus. "Analysis and support of work processes within chemical engineering design processes /." Düsseldorf : VDI-Verl, 2005. http://bvbr.bib-bvb.de:8991/F?func=service&doc_library=BVB01&doc_number=013342934&line_number=0001&func_code=DB_RECORDS&service_type=MEDIA.
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Pashalis, Despina. "Central cortical processes or peripheral motor processes differentiate extraverts from introverts /." Title page, table of contents and abstract only, 2002. http://web4.library.adelaide.edu.au/theses/09ARPS/09arpsp2818.pdf.
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Fittipaldi, María Clara. "Representation results for continuos-state branching processes and logistic branching processes." Tesis, Universidad de Chile, 2014. http://www.repositorio.uchile.cl/handle/2250/116458.
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Doctora en Ciencias de la Ingeniería, Mención Modelación MatemáticaEl objetivo de este trabajo es explorar el comportamiento de los procesos de rami ficación evolucionando a tiempo y estados continuos, y encontrar representaciones para su trayectoria y su genealogía. En el primer capítulo se muestra que un proceso de ramifi cación condicionado a no extinguirse es la única solución fuerte de una ecuación diferencial estocástica conducida por un movimiento Browniano y una medida puntual de Poisson, más un subordinador que representa la inmigración, dónde estos procesos son mutuamente independientes. Para esto se usa el hecho de que es posible obtener la ley del proceso condicionado a partir del proceso original, a través de su h-transformada, y se da una manera trayectorial de construir la inmigración a partir de los saltos del proceso. En el segundo capítulo se encuentra una representación para los procesos de rami ficación con crecimiento logístico, usando ecuaciones estocásticas. En particular, usando la de finición general dada por A. Lambert, se prueba que un proceso logístico es la única solución fuerte de una ecuación estocástica conducida por un movimiento Browniano y una medida puntual de Poisson, pero con un drift negativo fruto de la competencia entre individuos. En este capítulo se encuentra además una ecuación diferencial estocástica asociada con un proceso logístico condicionado a no extinguirse, suponiendo que éste existe y que puede ser de finido a través de una h-transformada. Esta representación muestra que nuevamente el condicionamiento da origen a un término correspondiente a la inmigración, pero en este caso dependiente de la población. Por último, en el tercer capítulo se obtiene una representación de tipo Ray-Knight para los procesos de ramifi cación logísticos, lo que da una descripción de su genealogía continua. Para esto, se utiliza la construcción de árboles aleatorios continuos asociados con procesos de Lévy generales dada por J.-F. Le Gall e Y. Le Jan, y una generalización del procedimiento de poda desarrollado por R. Abraham, J.-F. Delmas. Este resultado extiende la representación de Ray-Knight para procesos de difusión logísticos dada por V. Le, E. Pardoux y A. Wakolbinger.
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de, Azeredo Keating Jose B. B. "Managerial cognitions in technological innovation processes : a study of interpretative processes." Thesis, Aston University, 1993. http://publications.aston.ac.uk/10860/.
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In this research, conceptualizations of the links between technological innovation and organizational change are explored and recommendations in the literature concerning such changes are reviewed and criticized. Such recommendations do not usually address the details of social interactions by which organizational changes take place. As a consequence, the issue of how these recommendations become relevant for the actors who would carry them out is not addressed. The complexity of organizational change processes highlights the role of actors' interpretations of organizational reality. Interpretations take place through the use of language in the interaction between actors. Theoretical contributions and recommendations concerning organizational changes should be seen therefore as discourses which contribute to these interpretations. They will influence the process of change only if they become relevant for organizational actors'. A method for analysing discourse in organizations is presented. It is used to identify the variety of discourses which are put forward in organizations, and to describe the structure of their distribution among actors. The structures of discourses in three companies suggest that knowledge about technological innovation processes becomes relevant to the extent that it contributes to political/discursive processes maintained by actors attempting to secure or change their role definitions. It follows that recommendations concerning planned organizational change should take into account these processes explicitly. It is therefore suggested that the analysis of discourse can be a valuable instrument for monitoring change processes. Suggestions for further research are made, concerning (i) the development of the method itself and its use in real situations (ii) the study of how discourse structures evolve over time and episodes of change.
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MOLLMANN, Tonio. "Generalized Feller Processes and their Applications to Affine and Polynomial Processes." Doctoral thesis, Scuola Normale Superiore, 2022. http://hdl.handle.net/11384/112310.
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Serrano, Francisco de Castilho Monteiro Gil. "Fractional processes: an application to finance." Master's thesis, Instituto Superior de Economia e Gestão, 2016. http://hdl.handle.net/10400.5/13002.
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Mestrado em Matemática FinanceiraNeste trabalho é apresentada uma extensa descrição matemática, orientada para a modelação financeira, de três principais processos fracionários: o processo Browniano fracionário e os dois processos de Lévy fracionários. Mostram-se como estes processos podem ser originados. É explorado o conceito de auto-semelhança e apresentamos algumas noções de cálculo fracionário. Também é discutido o lugar destes processos no problema de encontrar o preço de derivados financeiros e apresentamos uma nova abordagem para a simulação do processo de Lévy fracionário que permite um método Monte Carlo para encontrar o preço de derivados financeiros.
In this work it is presented an extensive mathematical description oriented to financial modelling based on three main fractional processes: the fractional Brownian motion and both fractional Lévy processes. It is shown how these processes were originated. The concept of self-similarity is explored and we present some notions of fractional calculus. It is discussed the opportunity of these processes in pricing financial derivatives and we present a new approach for simulation of the fractional Lévy process, which allows a Monte Carlo method for pricing financial derivatives.
info:eu-repo/semantics/publishedVersion
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Turati, Ricardo de Carvalho. "Desenvolvimento de uma abordagem estatística dos tempos para o Lean Healthcare: uma proposta para análise dos tempos nos processos hospitalares." Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/18/18156/tde-29012016-133521/.
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Os hospitais são grandes organizações de serviços responsáveis pelo bem estar da população. Desempenham um papel importante na sociedade e também são responsáveis por boa parte dos recursos financeiros destinados a saúde. Diante deste cenário, os hospitais tem demandado um aumento no uso de ferramentas de gestão e melhoria de seus processos de negócio. Uma proposta para auxiliar neste processo, tem sido reportada na literatura como Lean Healthcare. Desse modo, o objetivo deste trabalho constituiu na proposição de uma abordagem estatística dos tempos para a análise das atividades nos processos hospitalares, de modo a identificar as variações existentes e contribuir com o gerenciamento do processo. A proposta foi desenvolvida utilizando a pesquisa teórica. Este método orientou o processo de desenvolvimento da AET- Abordagem Estatística dos Tempos, uma vez que a motivação para a sua elaboração estava alicerçada em uma proposta que pudesse contribuir com o aprimoramento do Lean Healthcare em hospitais. Os resultados teóricos da AET foram apresentados em três simulações (cenários I, II e III) para dois setores do hospital. Essas simulações atestaram que a variabilidade existente pode afetar diretamente os esforços de melhoria envolvidos, principalmente quando realizada a comparação de tempos de atividade em plantões diferentes Foi também realizada uma aplicação piloto em um processo de atendimento ambulatorial de um hospital regional no Estado de Mato Grosso do Sul. Na aplicação piloto foram utilizados os parâmetros comparativos, que ilustraram, de forma quantitativa, a influência que a variabilidade dos tempos pode desencadear na dinâmica do processo. Esta aplicação ocorreu em um pronto socorro, onde foi possível observar a variabilidade dos tempos em uma situação real. Essa aplicação demonstrou uma melhora na quantificação da variabilidade, pois analisou a variabilidade com base no comportamento dos dados, e não apenas pela média dos tempos ou pelos valores inferiores e superiores de uma amostra de tempos. Dessa aplicação resultou também a identificação de que a padronização do trabalho em ambientes hospitalares pode demandar mais esforços do que em ambientes de manufatura. Isto pode ser observado quanto ao distanciamento no atendimento da demanda, identificado pelo parâmetro LMV - Limite Máximo da Variação. Assim, a AET contribuiu para avaliar melhor a capacidade em atividade que agregam valor, e em relação as atividades que não agregam valor, ela auxiliou na identificação das possíveis causas dos desperdícios. A AET pode ajudar no planejamento das ações de melhoria, pois trouxe para a discussão um importante aspecto de o processo hospitalar: a variação existente nos tempos das atividades.Hospitals are big organizations services responsible for the welfare of the population. They play an important role in society and are also responsible for much of the financial resources for health. In this scenario, the hospital has demanded an increase in the use of management tools and improves their business processes. A proposal to assist in this process has been reported in the literature as Lean Healthcare. Thus, the objective of this work consisted in proposing a statistical approach of the times for the analysis of activities in the hospital processes in order to identify existing variations and contribute to the management of the process. The proposal was developed using theoretical research. This method guided the development process of SAT- Statistical Approach of the Times, since the motivation for its development was founded on a proposal that could contribute to the improvement of Lean Healthcare in hospitals. The theoretical results of SAT were presented in three simulations (scenarios I, II and III) for two hospital sectors. These simulations testified that the variability can directly affect the improvement efforts involved, especially when performed comparing activity times in different shifts. A pilot application was also performed in an outpatient service process of a regional hospital in the state of Mato Grosso do Sul. In the pilot application were used comparative parameters, which illustrated, in a quantitative manner, the influence of the variability of time may initiate the dynamics of the process. This application was in an emergency room, where it was observed in real situation. This application showed an improvement in quantification of variability because analyzed the variability based on data behavior, and not just the average of the time or the lower and upper values of a sample times. This application also resulted in the identification of the standardization work in hospital settings may require more effort than in manufacturing environments. This can be seen as the distance in meeting demand, identified by MLV parameter - Maximum Limit Variation. Thus, the SAT contributed to better assess the capacity of activity that add value, and in relation to activities that do not add value, it assisted in the identification of possible causes of waste. The SAT can help in the planning of improvement actions, as brought to the discussion an important aspect of the hospital process: the variation in the times of activities.
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Palau, Ortin David. "Dynamics of cellular decision making processes." Doctoral thesis, Universitat de Barcelona, 2016. http://hdl.handle.net/10803/396084.
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Cells, either as unicellular organisms or as part of a tissue of a multicellular organism, can acquire different functions thanks to their capability of changing their expression state. The enzyme synthesis, cell division or cell differentiation are some examples of these functions. The turning on and off of them lie in the mechanisms by which cells are able to integrate the information they perceive from the environment. Frequently, cells exhibit different responses under the same stimulus or environment. These probabilistic processes, whose behaviours are not univocal, are known as "cellular decision making". We can classify these processes according to the range at which the decision is made. We denominate cell-autonomous decision those in which of each cell chooses its response independently of the choice of the other cells of the population. By contrast, if the decision is made collectively by the whole population, it is classified as non autonomous. This second type of decisions involve mechanisms of cell-to-cell communication that mediate in the choices the cells and so, some spatial distributions of the different cell states can arise.
The capability of cellular decision making processes of performing a variety of responses under a same signal is given by the multistability and the stochasticity of their dynamics. While multistability is underlain by the nonlinear interactions of the elements involved in genetic regulation, stochasticity arises from the discrete nature of biochemical reactions and the thermal fluctuations of the cellular environment. These two characteristics motivate the study of these processes from Systems Dynamics the point of view, by identifying cell states with system attractors.
This Thesis focuses on the study of the general dynamical mechanisms that control cellular decision making processes. The main goal is to connect the properties of the decision with the relevant dynamical behaviour of the system while it is being made.
We have analysed the properties of cellular decisions in two systems: a system with cell-autonomous dynamics, where cells choose their state regardless the choice of the others; and a system where the decision is made jointly by all the tissue. In this second system, cells interact through a cell-to-cell communication that takes place at first neighbours. From these interactions, different pattern solutions arise, where different different cell types are spatially distributed along the tissue. Finally, it has been analysed the role that a specific choice, whose probability value is well known, plays in the functionality of an organism. The chosen system to study these consequences has been a process of differentiation that the parasite that causes malaria in humans performs.Cada célula, ya se como organismo unicelular o formando parte de un organismo multicelular, tiene que desarrollar distintas funciones a lo largo de su vida. Algunos ejemplos de estas funciones son tales como la síntesis de encimas, dividirse o diferenciarse en otro tipo celular. La activación y desactivación de muchas de estas funciones está sujeta a la integración de la información que la célula percibe de su entorno. A menudo, las células exhiben respuestas distintas bajo un mismo estímulo o bajo unas mismas condiciones del entorno. Estos procesos probabilísticos son conocidos como "toma de decisiones celulares". Estos eventos celulares se puede desarrollar de forma autónoma por cada célula, o de forma colectiva por toda una población o tejido. En este segundo caso, se requiere de algún mecanismo que medie en la comunicación entre células. Esta capacidad de estos sistemas de producir una variedad de respuestas es otorgada por la multiestabilidad y estocasticidad de sus dinámicas. Estas características motivan el estudio de estos procesos desde la perspectiva de la Dinámica de Sistemas, identificando los estados celulares a los atractores del sistema. Esta Tesis se centra en el estudio de los mecanismos dinámicos genéricos que controlan la toma de decisiones celulares. Se ha caracterizado la conexión entre las propiedades de una decisión y el mecanismo subyacente que la genera. Dos tipos decisiones autónomas han sido analizadas de acuerdo a esta perspectiva. También se ha estudiado los mecanismos dinámicos que llevan a la selección de un patrón espacial concreto en un escenario de decisión no autónoma, en el que las células interactúan entre sí a primeros vecinos mediante una inhibición lateral. Estas decisiones han revelado como la simetría especial de la señal inductora de las mismas afecta a la solución final alcanzada por el tejido. Finalmente, se ha analizado el papel que la probabilidad de una decisión concreta y bien conocida puede desarrollar en la viabilidad del organismo implicado. El sistema de estudio escogido ha sido un proceso de diferenciación que lleva a cabo el parásito responsable de causar la malaria en humanos.
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Hamann, Stephan [Verfasser]. "On aspects of chemical processes in surface modification plasma processes / Stephan Hamann." Greifswald : Universitätsbibliothek Greifswald, 2015. http://d-nb.info/1080392726/34.
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Dassios, Angelos. "Insurance, storage and point processes : an approach via piecewise deterministicc Markov processes." Thesis, Imperial College London, 1987. http://hdl.handle.net/10044/1/38278.
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Bechara, Rami. "Methodology for the design of optimal processes : application to sugarcane conversion processes." Thesis, Lyon 1, 2015. http://www.theses.fr/2015LYO10229/document.
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L'adoption d'une méthodologie est cruciale pour la conception de procédés chimiques optimaux. L'optimisation multi-objective de modèles rigoureux en est un exemple, jouissant d'une application extensive dans la littérature. Cette méthode retourne un ensemble de solutions, dit de Pareto, présentant un compromis optimal entre les fonctions objectives. Ceci est suivi par une étape de sélection d'une solution d'intérêt répondant à des critères définis. Cette méthodologie s'appliquait, dans le cadre de cette thèse, à deux procédés. Le premier consistait en une distillerie d'éthanol à partir de la canne à sucre, combinée à un système de cogénération et de combustion à partir de la biomasse de canne à sucre. Le deuxième contenait en plus un système d'hydrolyse enzymatique de cette biomasse. Notre première contribution traitait de la construction d'une procédure pour la modélisation, simulation, intégration thermique et évaluation du coût des équipements. La deuxième contribution traitait de l'analyse des résultats réalisée à travers un suivi de variables mesurées, une fragmentation de la courbe de Pareto, une hiérarchisation des variables de décision et une comparaison avec la littérature. La dernière contribution traitait de l'étape de sélection qui s'est réalisée à travers une évaluation économique des solutions, sous des scénarii différents, avec la Valeur Nette Présente comme critère de sélection. En conclusion, cette thèse constitue une première application intégrale de la méthodologie proposée. Elle représente, de par ses contributions, un tremplin pour des applications futures à des procédés chimiques ou biochimiques, plus spécialement pour la canne à sucreThe use of a systematic methodology is crucial for the design of optimal chemical processes, namely bio-processes. Multi-objective optimization of rigorous process models is therein a prime example, with extensive use in literature. This method yields a Pareto set of optimal compromise solutions, from which one optimal solution is chosen based on specific criteria. This methodology was applied, in the course of this thesis, to two studied processes. The first consisted in a distillery converting sugarcane to ethanol, combined with a sugarcane biomass combustion and power cogeneration system. The second contained an additional biomass hydrolysis system. Our first contribution deals with the construction of an organized procedure for the modeling, simulation, heat integration and equipment and capital cost estimation of chemical processes. The second contribution deals with the analysis of the optimization results through a tracking of measured variables, the fragmentation of the Pareto curve, an ordering of optimization variables, and a comparisons with literature results. The final realization deals with the selection step realized through an economic evaluation of optimal solutions for various scenarios, with the Net Present Value as the selection criterion. In conclusion, this thesis constitutes a first integral application of the said methodology. It sets, through its contributions, a stepping stone for future application in the field of chemical and biochemical processes, namely for sugarcane processes