This thesis explored how asphaltene and naphthenic amphiphile species influence the formation (morphology and size) and stability of heavy crude oil (bitumen) emulsions. It was experimentally shown that asphaltenes produce water-in-oil emulsions. Naphthenic amphiphiles on the other hand flip the emulsion morphology to oil-in-water. It was further demonstrated that the size and stability of these emulsions is influenced by physicochemical effects such as the pH, solvent-bitumen-water ratios, solvent aromaticity, and temperature. In view of these findings, the hydrophilic-lipophilic deviation (HLD) and net-average curvature (NAC) models were looked at as potential means for predicting the formation and stability of emulsions. Owing to the complexity of bitumen emulsions, however, the HLD and NAC models were instead tested against well-defined sodium dihexyl sulfosuccinate-toluene-water emulsions. The morphologies of these emulsions were predicted as a function of the formulation salinity whereas corresponding droplet sizes were predicted as a function of the continuous phase density and interfacial tension (γow). Emulsion stability trends were in turn predicted using a collision-coalescence-separation assumption. From this assumption, emulsion stability was expressed as a function of the emulsion droplet collision frequency and activation energy. The key parameters of the highly scrutinized activation energy term included the γow, interfacial rigidity, and critical film thickness. In applying the same modeling approach to the stability of other emulsions already published in the literature, it was found that the rigidity of adsorbed multilayer/liquid crystal films cannot yet be fully accounted for. This shortcoming was the reason for which only minimum stability times were reported for bitumen emulsions.

Purpose The thesis purpose is to contribute with understanding about managers’ opinions about how to handle deviations caused by unit interdependence. Methodology Qualitative data has been gathered to this exploratory study by semi-structured interviews with 14 managers within the R&D, purchasing and production units at Scania, Södertälje. The result has been interpreted and analyzed by dividing the managers in five smaller groups.  Result from analyzing empirical findings It is found in the analysis that the largest part of the managers in this study seem not to believe it is worth striving for excellence through procedural justice. Reoccurring similarities in opinion between managers is that visualization, dialogue, clear responsibility and less tolerance towards deviations are needed for handling and preventing deviations. Differences in opinion are primarily related to how costs occurred from deviations should be allocated and the purpose with such reallocation. Most managers express a strong concern about undesired behavior developed by a control system where a causing unit always should take the effect from a deviation. However, all managers state that costs occurred from deviations due to interdependence with a external supplier should be invoiced to the supplier.  Conclusion The concern about undesired behavior that may be developed by the way of handling and preventing deviation is strongly mediated by the managers. Instead of handling deviations by justly reallocating effects according to the controllability principle it is perceived as more important to extend the areas of responsibility and increase consciousness between interdependent units through improved dialogue and cross-functional transparency. One should therefore not seek equitable allocation of impacts and cost of devices in dealing with anomalies of this type.

No description available.

Samhället är uppbyggt av organisationer som i olika grad kan vara i behov av styrning för att upprätthålla en viss funktion. Studiens syfte är att undersöka hur organisationer inom privat sektor konkret tillämpar styrning och hur arbetet med styrning följs upp. Forskningsfrågor som besvaras är: vad bidrar styrning med till en organisation och dess måluppfyllelse samt på vilket sätt påverkar styrningen hur ledningen använder och arbetar med resultat samt avvikelser? Studien är kvalitativ där datainsamlingen gjorts med semistrukturerade-intervjuer samt genom fenomenografi, det vill säga med en kvalitativ inriktad empirisk forskningsansats. Urvalet av respondenter gjordes inom Västra Götaland där ett 20-tal privata organisationer kontaktades för att erhålla svar om deltagande från potentiella respondenter. Vilket slutligen resulterade i Åtta genomförda intervjuer. Kravprofil för respondenter var minst tio års erfarenhet av arbete med styrning och arbete i ledande ställning. Styrning kan innebära vad en organisation väljer att beakta, komplexiteten handlar om i vilken kontext styrning placeras. Grundläggande frågor att klargöra kan vara: hur styrning kan implementeras, vilka mål och syfte styrningen kan tjäna en organisation eller vilka resultat styrningen förväntas leda till. Resultatet visar att styrning kan ha en betydande roll när det gäller att nå uppsatta mål och att kunna nå ett visst resultat. Det resonemanget stödjs av litteratur och forskning, samt empiri. För författarna framträder det tydligt bland respondenterna att val av styrmodell kanske inte utgör det mest väsentliga. Istället kan det handla om prioriteringar som ledningen valt att fokusera på, och hur detta delges medarbetare. Organisationer kan påverkas direkt eller indirekt av omvärldsfaktorer och globalisering, faktorer som en organisation kan behöva hitta strategier för att hantera. Medvetna ledare kan styra en organisation med hänsyn till faktorer som påverkar och inverkar på en verksamhets målsättning samt planerade resultat. Arbetet med styrning kan innebära processer där olika verktyg och styrmodeller samverkar för att generera mätdata. Mätetal används till uppföljning, kontroll och till att ge återkoppling till en verksamhet. Mål och resultat kan på olika sätt vara kopplade både till styrning samt val av strategi. Konsekvenser som rör val av styrning ytterst handlar om: att nå önskat resultat, förstå processen som vägen till målet innebär och ytterst att en organisation ska överleva / Communities are made up of organizations as in different degrees may be in need of control to maintain a certain function. This paper aims to examine how organizations in the private sector specific application control and how the process of control are followed up. Research questions as are trying to be answered is: what control contributes to an organization and its effectiveness? And in which way control affect how management uses and works with results and anomalies? The study was conducted using a qualitative approach and semi-structured interviews. The selection of respondents was done in Västra Götaland, where 20 private organizations were contacted to participate in the study. It resulted in eight interviews conducted. Demand profile of respondents were at least ten years of experience working with control and working in senior positions. The results show that control can mean what an organization chooses to consider, the complexity is about the context in which the control is placed. Basic questions to answer include: how control can be implemented, the goals and objectives of control can serve an organization or what performance management is expected to lead to. Control may have a significant role in achieving set goals and to achieve a specific result. This reasoning is supported by the literature and research, and empirical data. For authors emerges clearly among respondents that the choice of control model may not represent the most significant. Instead, it may be about priorities that management focus on control and how this is communicated to employees. Organizations can directly or indirectly affected by external factors and globalization, factors that an organization may need to find strategies to cope. Conscious leaders can control an organization with regard to the factors that influence and affect an organization's objectives and planned results. Work on control may involve processes where different tools and models of control interact to generate the data. Metrics used for monitoring, control, and to provide feedback to a business. Objectives and results can be different ways be linked to both the control and the choice of strategy. The impacts on the choice of control are ultimately about: achieving desired results, understand the process as the way to the target means and ultimately enable an organization to survive

In view of the current situation of fluctuating high crude oil prices, it is now more important than ever for petroleum refineries to operate at an optimal level in the present dynamic global economy. Acknowledging the shortcomings of deterministic models, this work proposes a hybrid of stochastic programming formulations for an optimal midterm refinery planning that addresses three factors of uncertainties, namely price of crude oil and saleable products, product demand, and production yields. An explicit stochastic programming technique is utilized by employing compensating slack variables to account for violations of constraints in order to increase model tractability. Four approaches are considered to ensure both solution and model robustness: (1) the Markowitz???s mean???variance (MV) model to handle randomness in the objective coefficients of prices by minimizing variance of the expected value of the random coefficients; (2) the two-stage stochastic programming with fixed recourse approach via scenario analysis to model randomness in the right-hand side and left-hand side coefficients by minimizing the expected recourse penalty costs due to constraints??? violations; (3) incorporation of the MV model within the framework developed in Approach 2 to minimize both the expectation and variance of the recourse costs; and (4) reformulation of the model in Approach 3 by adopting mean-absolute deviation (MAD) as the risk metric imposed by the recourse costs for a novel application to the petroleum refining industry. A representative numerical example is illustrated with the resulting outcome of higher net profits and increased robustness in solutions proposed by the stochastic models.

This thesis explored how asphaltene and naphthenic amphiphile species influence the formation (morphology and size) and stability of heavy crude oil (bitumen) emulsions. It was experimentally shown that asphaltenes produce water-in-oil emulsions. Naphthenic amphiphiles on the other hand flip the emulsion morphology to oil-in-water. It was further demonstrated that the size and stability of these emulsions is influenced by physicochemical effects such as the pH, solvent-bitumen-water ratios, solvent aromaticity, and temperature. In view of these findings, the hydrophilic-lipophilic deviation (HLD) and net-average curvature (NAC) models were looked at as potential means for predicting the formation and stability of emulsions. Owing to the complexity of bitumen emulsions, however, the HLD and NAC models were instead tested against well-defined sodium dihexyl sulfosuccinate-toluene-water emulsions. The morphologies of these emulsions were predicted as a function of the formulation salinity whereas corresponding droplet sizes were predicted as a function of the continuous phase density and interfacial tension (γow). Emulsion stability trends were in turn predicted using a collision-coalescence-separation assumption. From this assumption, emulsion stability was expressed as a function of the emulsion droplet collision frequency and activation energy. The key parameters of the highly scrutinized activation energy term included the γow, interfacial rigidity, and critical film thickness. In applying the same modeling approach to the stability of other emulsions already published in the literature, it was found that the rigidity of adsorbed multilayer/liquid crystal films cannot yet be fully accounted for. This shortcoming was the reason for which only minimum stability times were reported for bitumen emulsions.

Depuis l'avènement du réseau Internet, le volume de données échangées sur les réseaux a crû de manière exponentielle. Le matériel présent sur les réseaux est devenu très hétérogène, dû entre autres à la multiplication des "middleboxes" (parefeux, routeurs NAT, serveurs VPN, proxy, etc.). Les algorithmes exécutés sur les équipements réseaux (routage, “spanning tree”, etc.) sont souvent complexes, parfois fermés et propriétaires et les interfaces de supervision peuvent être très différentes d'un constructeur/équipement à un autre. Ces différents facteurs rendent la compréhension et le fonctionnement du réseau complexe. Cela a motivé la définition d'un nouveau paradigme réseaux afin de simplifier la conception et la gestion des réseaux : le SDN (“Software-defined Networking”). Il introduit la notion de contrôleur, qui est un équipement qui a pour rôle de contrôler les équipements du plan de données. Le concept SDN sépare donc le plan de données chargés de l'acheminement des paquets, qui est opéré par des équipements nommés virtual switches dans la terminologie SDN, et le plan contrôle, en charge de toutes les décisions, et qui est donc effectué par le contrôleur SDN. Pour permettre au contrôleur de prendre ses décisions, il doit disposer d'une vue globale du réseau. En plus de la topologie et de la capacité des liens, des critères de performances comme le délai, le taux de pertes, la bande passante disponible, peuvent être pris en compte. Cette connaissance peut permettre par exemple un routage multi-classes, ou/et garantir des niveaux de qualité de service. Les contributions de cette thèse portent sur la proposition d'algorithmes permettant à une entité centralisée, et en particulier à un contrôleur dans un cadre SDN, d'obtenir des estimations fiables du délai de bout-en-bout pour les flux traversant le réseau. Les méthodes proposées sont passives, c'est-à-dire qu'elles ne génèrent aucun trafic supplémentaire. Nous nous intéressons tout particulièrement à la moyenne et l'écart type du délai. Il apparaît que le premier moment peut être obtenu assez facilement. Au contraire, la corrélation qui apparaît dans les temps d'attentes des noeuds du réseau rend l'estimation de l'écart type beaucoup plus complexe. Nous montrons que les méthodes développées sont capables de capturer les corrélations des délais dans les différents noeuds et d'offrir des estimations précises de l'écart type. Ces résultats sont validés par simulations où nous considérons un large éventail de scénarios permettant de valider nos algorithmes dans différents contextes d'utilisation / Since the early beginning of Internet, the amount of data exchanged over the networks has exponentially grown. The devices deployed on the networks are very heterogeneous, because of the growing presence of middleboxes (e.g., firewalls, NAT routers, VPN servers, proxy). The algorithms run on the networking devices (e.g., routing, spanning tree) are often complex, closed, and proprietary while the interfaces to access these devices typically vary from one manufacturer to the other. All these factors tend to hinder the understanding and the management of networks. Therefore a new paradigm has been introduced to ease the design and the management of networks, namely, the SDN (Software-defined Networking). In particular, SDN defines a new entity, the controller that is in charge of controlling the devices belonging to the data plane. Thus, in a SDN-network, the data plane, which is handled by networking devices called virtual switches, and the control plane, which takes the decisions and executed by the controller, are separated. In order to let the controller take its decisions, it must have a global view on the network. This includes the topology of the network and its links capacity, along with other possible performance metrics such delays, loss rates, and available bandwidths. This knowledge can enable a multi-class routing, or help guarantee levels of Quality of Service. The contributions of this thesis are new algorithms that allow a centralized entity, such as the controller in an SDN network, to accurately estimate the end-to-end delay for a given flow in its network. The proposed methods are passive in the sense that they do not require any additional traffic to be run. More precisely, we study the expectation and the standard deviation of the delay. We show how the first moment can be easily computed. On the other hand, estimating the standard deviation is much more complex because of the correlations existing between the different waiting times. We show that the proposed methods are able to capture these correlations between delays and thus providing accurate estimations of the standard deviation of the end-to-end delay. Simulations that cover a large range of possible scenariosvalidate these results

Esta tese tem como objetivo central analisar a violação e recuperação da confiança do cliente na empresa após a recuperação de uma falha malsucedida – situação de duplo desvio. No escopo do objetivo central, é verificado o efeito intensificador da violação da confiança oriundo do duplo desvio; o efeito que a promessa de não recorrência das falhas e o pedido de desculpa, enquanto táticas de recuperação, possuem na confiança; o papel das atribuições de competência e integridade para explicar os efeitos das táticas de recuperação da confiança; e o efeito moderador tanto do tipo de violação da confiança quanto da distância temporal entre a ocorrência do duplo desvio e a inserção da tática, na relação entre a tática de recuperação e a confiança. Para verificar estes efeitos, quatro estudos experimentais foram operacionalizados. Os resultados do primeiro estudo indicam que a violação da confiança é maior após o duplo desvio, comparativamente com o nível de confiança identificado após o desvio simples. No segundo estudo, a possibilidade de recuperação da confiança por meio da promessa de não recorrência das falhas e do pedido de desculpa foi verificada. Os resultados deste segundo estudo indicam que tanto a promessa quanto o pedido de desculpa geram níveis mais elevados de confiança na empresa que a condição de controle (sem tática alguma) e outras duas táticas de recuperação da confiança utilizadas. Além disso, o estudo dois também apresenta que os efeitos das táticas de recuperação na confiança são totalmente mediados pelas atribuições de competência ou atribuições de integridade. No terceiro estudo, os resultados indicam que a efetividade da tática de recuperação depende do tipo de violação da confiança a que o sujeito foi submetido, sendo que a promessa gerou níveis mais elevados de confiança quando a violação da confiança foi baseada na competência, enquanto o pedido de desculpa gerou níveis mais elevados de confiança quando a violação da confiança foi baseada na integridade. No último estudo experimental, os resultados evidenciam uma interação entre a tática de recuperação da confiança e a distância temporal entre o duplo desvio e a inserção da tática, sendo que o pedido de desculpa gerou maiores níveis de confiança quando a distância foi curta (vs. longa), enquanto a promessa gerou maiores níveis de confiança quando esta distância foi longa (vs. curta). Baseado nisto, esta tese contribui para a literatura de Marketing e recuperação da confiança ao evidenciar que: o duplo desvio intensifica os efeitos negativos na confiança gerados pelo desvio simples; é possível recuperar a confiança após o duplo desvio, por meio da promessa e do pedido de desculpa; as pistas emitidas pela tática e a atribuição do sujeito explicam o funcionamento das táticas de recuperação da confiança; e tanto o tipo de violação da confiança quanto a distância temporal condicionam os efeitos das táticas de recuperação. / This dissertation aims at analyzing the breach and recovery of customer trust in the company after a poor failure recovery - a double deviation situation. Its objective is to investigate the greater effect of trust violation derived from the double deviation situation; the effect that the promise of non-recurrence of failures and apology as trust recovery tactics have on trust; the role of attributions of competence and integrity to explain the effects of trust recovery tactics; and the moderating effect of both trust violation type and temporal distance between the occurrence of double deviation and tactics insertion, in the relationship between recovery tactics and trust. In order to verify these effects, four experimental studies were operationalized. The results from the first study indicate that the breach of trust is higher after the double deviation, compared with the level of trust identified after the simple deviation. In the second study, the possibility of trust restitution by the promise of non-recurrence of failures and apology was verified. The results of this second study indicate that both promise and apology generate higher levels of trust in the company than the control condition (without any tactics) and two other tactics used to restore trust. Furthermore, the second study also shows that the effects of both recovery tactics on trust are fully mediated by attributions of competence or integrity. In the third study, the findings indicate that the effectiveness of recovery tactics depends on the type of trust violation to which the subject was submitted. Whereas the promise generated higher levels of trust when the violation was based on competence, the apology generated higher levels of trust when the violation was based on integrity. In the last experimental study, the results indicate an interaction between the trust recovery tactics and the temporal distance, between the double deviation and the tactics insertion, given that the apology has generated greater levels of trust when the distance was short (vs. long); while the promise generated higher levels of trust when this distance was long (vs. short). Based on that, this dissertation contributes to the marketing and trust recovery literature by showing that: the double deviation intensifies the negative effects on trust generated by the simple deviation, it is possible to rebuild trust after double deviation, through promise and apology; the cues expressed by the recovery tactics and the subject attribution explain the mechanism through which the trust recovery tactics operates; and both the violation of trust type, as well as the temporal distance condition the effects of recovery tactics.

O conhecimento do risco de ativos financeiros é de fundamental importância para gestão ativa de carteiras, determinação de preços de opções e análise de sensibilidade de retornos. O risco é medido através da variância estatística e há na literatura diversos modelos econométricos que servem a esta finalidade. Esta pesquisa contempla o estudo de modelos determinísticos de volatilidade, mais especificamente os modelos GARCH simétricos e assimétricos. O período de análise foi dividido em dois: de janeiro de 2000 à fevereiro de 2008 e à outubro de 2008. Tal procedimento foi adotado procurando identificar a influência da crise econômica originada nos EUA nos modelos de volatilidade. O setor escolhido para o estudo foi o mercado de petróleo e foram escolhidas as nove maiores empresas do setor de acordo com a capacidade produtiva e reservas de petróleo. Além destas, foram modeladas também as commodities negociadas na Bolsa de Valores de Nova York: o barril de petróleo do tipo Brent e WTI. A escolha deste setor deve-se a sua grande importância econômica e estratégica para todas as nações. Os resultados encontrados mostraram que não houve um padrão de modelo de volatilidade para todos os ativos estudados e para a grande maioria dos ativos, há presença de assimetria nos retornos, sendo o modelo GJR (1,1) o que mais prevaleceu, segundo a modelagem pelo método da máxima verossimilhança. Houve aderência, em 81% dos casos, dos ativos a um determinado modelo de volatilidade, alterando apenas, como eram esperados, os coeficientes de reatividade e persistência. Com relação a estes, percebe-se que a crise aumentou os coeficientes de reatividade para alguns ativos. Ao se compararem as volatilidades estimadas de curto prazo, percebe-se que o agravamento da crise introduziu uma elevação média de 265,4% em relação ao período anterior, indicando um aumento substancial de risco. Para a volatilidade de longo prazo, o aumento médio foi de 7,9%, sugerindo que os choques reativos introduzidos com a crise, tendem a ser dissipados ao longo do tempo. / The knowledge of the risk of financial assets is of basic importance for active management of portfolios, determination of prices of options and analysis of sensitivity of returns. The risk is measured through the variance statistics and has in literature several econometrical models that serve to this purpose. This research contemplates the study of deterministic models of volatility, more specifically symmetrical and asymmetrical models GARCH. The period of analysis was divided in two: January of 2000 to the February of 2008 and the October of 2008. Such a proceeding was adopted trying to identify the influence of the economic crisis given rise in U.S.A. in the volatility models. The sector chosen for the study was the oil market and had been chosen the nine bigger companies of the sector in accordance with the productive capacity and reserves of oil. Beyond these, there were modeled also the commodities negotiated in the Stock Exchange of New York: the barrel of oil of the types Brent and WTI. The choice of this sector is due to his great economical and strategic importance for all the nations. The results showed that there was no a standard of model of volatility for all the studied assets and for the majority of them, there is presence of asymmetry in the returns, being the model GJR (1,1) that more prevailed, according to the method of likelihood. There was adherence, in 81 % of the cases, of the assets to a determined model of volatility, altering only the coefficients of reactivity and persistence. Regarding these, it is realized that the crisis increased the coefficients of reactivity for some assets. In relation to the volatilities of short term, it is realized that the aggravation of the crisis introduced an elevation of 265,4% regarding the previous period, indicating a substantial increase of risk. In relation to the volatility of long term, the increase was 7,9 %, suggesting that the reactive shocks introduced with the crisis have a tendency to be dispersed along the time.

p. 1-147 / Submitted by Santiago Fabio (fabio.ssantiago@hotmail.com) on 2013-03-07T18:40:26Z No. of bitstreams: 1 7777qqq.pdf: 1250897 bytes, checksum: 4c7afd06a395d049360a332991ea01be (MD5) / Approved for entry into archive by Tatiana Lima(tatianasl@ufba.br) on 2013-03-14T19:38:37Z (GMT) No. of bitstreams: 1 7777qqq.pdf: 1250897 bytes, checksum: 4c7afd06a395d049360a332991ea01be (MD5) / Made available in DSpace on 2013-03-14T19:38:37Z (GMT). No. of bitstreams: 1 7777qqq.pdf: 1250897 bytes, checksum: 4c7afd06a395d049360a332991ea01be (MD5) Previous issue date: 2006 / Esta dissertação tem por objetivo verificar as relações existentes entre o significado do trabalho e a conduta ético-profissional do policial militar baiano. Trata-se de um estudo descritivo, cujo modelo de análise contempla o caráter multifacetado do trabalho, abrangendo as dimensões ou facetas: centralidade, produtos ou resultados valorados do trabalho, normas societais e atributos valorativos e descritivos. O estudo empírico envolveu uma pesquisa de campo, abrangendo uma amostra de 113 policiais, subdividida em três grupos: policiais elogiados por suas condutas; detidos por condutas ilícitas e policiais com condutas desviantes, porém em exercício profissional. Os dados foram coletados através do instrumento do MOW, adaptado por Soares (1992) e analisados com o auxílio do programa SPSS. Verificou-se que o trabalho tem elevado índice de centralidade para os policiais, exercendo uma função instrumental como meio de obtenção de recursos financeiros, além de significar um modo útil de servir à sociedade e de auto-realização. Embora não tenham sido encontradas diferenças estatisticamente significantes entre os três grupos pesquisados em relação a todas as dimensões do trabalho, observou-se que os policiais elogiados atribuem uma importância maior ao trabalho do que os outros dois grupos, que a família, seguida do trabalho, constituem-se nas dimensões mais importantes para os policiais elogiados e os praticantes de condutas delitivas, enquanto que a família e a religião são as esferas mais valorizadas pelos policiais detidos, ocupando o trabalho a terceira posição. Verificou-se também uma dissonância entre os atributos valorativos e descritivos do trabalho. Os resultados sugerem a necessidade de que estudos de maior abrangência possam ser conduzidos, com vistas a ampliar a compreensão da relação entre significado do trabalho e conduta ético-profissional. / Salvador