Blends of poly butylene terephthalate (PBT) and polycarbonate (PC) form a very important class of commercial blends in numerous applications requiring materials with good chemical resistance, impact resistance even at low temperatures, and aesthetic and flow characteristics. PC and PBT are usually blended in a twin screw extruder (TSE). Product melt volume flow rate (MVR) is a property used to monitor product quality while blending the PC/PBT in a twin screw extruder. It is usually measured off line in a quality control laboratory using extrusion plastometer on samples collected discretely during the compounding operation. Typically a target value representing the desired value of the quality characteristics for an in-control process, along with upper and lower control limits are specified. As long as the MVR measurement is within the control limits, the sample is approved and the whole compounded blend is assumed to meet the specification. Otherwise, the blend is rejected. Because of infrequent discrete sampling, corrective actions are usually applied with delay, thus resulting in wasted material. It is important that the produced PC/PBT blend pellets have consistent properties. Variability and fault usually arise from three sources: human errors, feed material variability, and machine operation (i.e. steady state variation). Among these, the latter two are the major ones affecting product quality. The resulting variation in resin properties contributes to increased waste products, larger production cost and dissatisfied customers. Motivated by this, the objective of this project was to study the compounding operation of PC/PBT blend in a twin screw extruder and to develop a feasible methodology that can be applied on-line for monitoring properties of blends on industrial compounding operations employing available extruder input and output variables such as screw speed, material flow rate, die pressure and torque. To achieve this objective, a physics-based model for a twin screw extruder along with a MVR model were developed, examined and adapted for this study, and verified through designed experiments. This dynamic model for a TSE captures the important dynamics, and relates measurable process variables (screw speed, torque, feed rates, pressure etc.) to ones that are not being measured (material holdups and compositions at the partially and filled section along a TSE barrel). This model also provides product quality sensors or inferential estimation techniques for prediction of viscosity and accordingly MVR. The usefulness of the model for inferential MVR sensing and fault diagnosis was demonstrated on experiments performed on a 58 mm co-rotating twin-screw extruder for an industrial compounding operation at a SABIC Innovative Plastics plant involving polycarbonate – poly butylene terephthalate blends. The results showed that the model has the capability of identifying faults (i.e., process deviation from the nominal conditions) in polymer compounding operations with the twin screw extruder. For instance, the die pressure exhibited a change as a function of changes in raw materials and feed composition of PC and PBT. In the presence of deviations from nominal conditions, the die pressure parameters are updated. These die pressure model parameters were identified and updated using the recursive parameter estimation method. The recursive identification of the die pressure parameters was able to capture very well the effects of changes in raw material and/or composition on the die pressure. In addition, the developed MVR model showed a good ability in monitoring product MVR on-line and inferentially from output process variables such as die pressure which enables quick quality control to maintain products within specification limits and to minimize waste production.

The aim of the current study is to model (non-wetting) liquid flow in a packed bed under the influence of gas flow. It has been observed experimentally that non-wetting liquid flows in a packed bed in form of small droplets and rivulets falling through the void regions. Continuum models have not been successful in predicting liquid flow paths when the liquid is injected through a point source in the packed bed. In the current study, we present a discrete deterministic model for modeling the liquid flow in a packed bed, under the influence of gas flow. When a high velocity gas blast in injected into a dry packed bed, a cavity or a void is formed in front of the nozzle. The cavity size increases with increasing gas velocity and exhibits hystersis in size upon increasing and decreasing gas flow rate. The cavity size is very important in determining the gas penetration into the packed bed. A proper gas flow profile prediction is necessary for determining it’s effect on the liquid flow behavior. Attempts at modeling cavity sizes have mostly been confined to experimental studies and development of correlations. Different correlations show different dependence on operating as well as bed parameters and a fundamental understanding of the cavity formation and hystersis phenomena is missing. We adopt a combined Eulerean-Lagrangian approach to study the above mentioned phenomena mathematically. Gas is modeled as a continua and solid as discrete (soft sphere D.E.M. approach). Hystersis and cavity formation studies are carried out in a 2D-slot rectangular packed bed. A discrete deterministic liquid flow model (developed and validated under structured packing conditions using x-ray radiography flow visualization technique), is used to study the effect of presence of liquid on the dry bed void size, when liquid is injected in a packed bed through a point source. It is found that the gas pushes the liquid away from the nozzle side wall. Also, the cavity sizes during gas velocity decreasing case are found to be larger in size than the void size obtained during velocity increasing case for the same inlet gas flow rate. This difference is void size leads to more gas penetration into the bed and thus more liquid shift away from the nozzle side wall. Presence of liquid is found to affect the void size (compared to dry bed size) negligibly.

A two-dimensional Boundary Element Method (BEM) is developed to study the strongly nonlinear interaction between a surface-piercing body and the free-surface. The scheme is applied to problems with and without the possibility of ventilation resulting from the motion and geometric configuration of the surface-piercing body. The main emphasis of this research work is on the development of numerical methods to improve the performance prediction of surface-piercing propellers by including the whole range of free-surface nonlinearities. The scheme is applied to predict the ventilated cavity shapes resulting from the vertical and rotational motion of a blade-section with fully nonlinear free-surface boundary conditions. The current method is able to predict the ventilated cavity shapes for a wide range of angles of attack and Froude numbers, and is in good agreement with existing experimental results. Through a comparison with a linearized free-surface method, the current method highlights the shortcomings of the negative image approach used commonly in two-dimensional and three-dimensional numerical methods for surface-piercing hydrofoils or propellers. The current method with all its capabilities makes it a unique contribution to improving numerical tools for the performance prediction of surface-piercing propellers. The scheme is also applied to predict the roll and heave dynamics of two-dimensional Floating Production Storage and Offloading (FPSO) vessel hull sections within a potential flow framework. The development of the potential flow model is aimed at validating the free-surface dynamics of an independently developed Navier Stokes Solver for predicting the roll characteristics of two-dimensional hull sections with bilge keels. / text

企業營運績效通常是以會計報表上的數字為參考，例如，資產報酬率(ROA)、每股盈餘(EPS)、股東權益報酬率(ROE)與資本報酬率(ROC)等，但這些數字通常受制於許多會計規範，且忽略股東資金成本，若只觀察這些會計數據可能無法忠實呈現一間公司的實際價值與績效。1995年由紐約Stern Stewart & Co.財務顧問公司所提出一個結合會計及經濟之觀念的財務績效衡量指標，現在已廣被使用作為企業價值的衡量工具。能夠以目前會計報表裡的資訊運用若干公式原理而更能充分的呈現在原始會計報表無法獲取的有用的訊息，而更能夠以投資者的角度觀察企業經營者所制定之決策是否以股東之權益為優先考量。本研究係採個案研究方式，分析經濟附加價值，並應用企業評價中自由現金流量折現法，經由三種假設情況下的情境分析，評估個案公司企業價值；最後透過敏感性分析拆解選取關鍵驅動因子，作為提供個案公司未來營運策略與方針之參考。 / The measurement of the firm’s performance usually rely on a lot of normal accounting statements, for example assets rate of returns (ROA ) , per share surplus (EPS ) , stockholder's equity rate of returns (ROE ) and rate of returns of capital (ROC ) ,etc. Those numbers have to follow the Generally Accepted Accounting Principles（GAAP）and ignore the cost of equity. If only observe those accounting numbers, it is hard to faithfully expressing the real value and performance of an enterprise. The Economics Value Added (EVA) concept was proposed in 1995 by the New York Stern Stewart & Co. financial adviser company. It combination of accounting and economic concepts based on financial performance measures. It can show some primitive useful message that accounting statement can't be obtained abundant at present. This concept has been widely be used as a measure of corporate value tool. Our research, which applies case study method, attempts to analyze the EVA value and determine the value of company S by using the discounted free cash flow model under three hypothetic scenarios. In addition, we conduct sensitivity analysis model to find the key value-driving factor of the company, which will be considered in planning future operating strategy.

Este trabalho apresenta proposta de modelo matemático para o problema de expansão do sistema de transmissão baseado no fluxo de carga CC considerando a utilização de links CC e FACTS resolvido através de metodologia de solução que considera a primeira e a segunda lei de Kirchhoff em processo enumerativo de branch-and-bound adaptado. A abordagem possui dois pontos em destaque: i) apresenta uma proposta de modelo matemático com possibilidade da utilização direta em problemas de expansão de linhas de transmissão que possuem tanto linhas de transmissão CA, transformadores, links CC e dispositivos FACTS e ii) é um método exato de solução do problema que garante a otimalidade da resposta e traz uma contribuição ao tradicional método branch-and-bound por incluir relaxações adicionais. O método aplicado aos sistemas de 6 barras de Garver e sistema Sul sudeste Brasileiro de 46 barras apresenta respostas adequadas e o modelo matemático testado em um sistema Garver modificado apresenta novas configurações possíveis com redução do custo total do investimento. / This work proposes a mathematical model to the transmission expansion system problem based on the DC power flow model considering the use of DC links and FACTS that is solved using a solution method considering the first and second Kirchhoff’s Law in an enumerative adapted branch-and-bound process. It is possible to highlight two key aspects of the proposed approach: i) presents a mathematical model that can be directly used on expansion transmission systems problems that have AC transmission lines, transformers, DC links and FACTS and ii) is an exact solution method that guarantees the optimum problems’s solutions and contributes to the traditional branch-and-bound method bringing additional relaxations. The solution method applied to Garver’s six-bus network and southeast Brazilian 46 bus network provides correct answers and the mathematical model tested on a modified Garver’s six-bus network presents new possible configurations that enables overall cost reduction to the problem.

Embora haja um consenso sobre a importância do valor da marca, um modelo de estimação único e uniformemente aceito ainda não surgiu, nem na perspectiva baseada no cliente ou consumidor nem na perspectiva da firma ou financeira. Assim, os profissionais de marketing ainda são desafiados a estimar o valor da marca. Além disso, é importante para a construção de um modelo de estimativa de valor da marca detectar as percepções dos consumidores e também apresentar uma estimativa monetária do valor da marca, satisfazendo às exigências de financistas, contabilistas e acionistas empresariais. A maioria dos modelos de valor da marca baseado no consumidor existentes não oferece uma estimativa monetária do valor da marca e muitos modelos de valor da marca baseado na firma não observam as percepções dos consumidores. A maioria deles não avalia o desempenho das marcas em futuros períodos de tempo. Esta pesquisa desenvolveu um modelo que permite estimar o valor da marca observando as probabilidades de escolha (manutenção ou troca) de marca pelos consumidores, com a aplicação da Matriz de Troca Markov. A matriz de troca de marca foi estimada por um estudo transversal, utilizando um modelo de escolha logit, analisando todas as marcas competidoras no mercado. Esta pesquisa também investigou o valor monetário da marca, utilizando o mecanismo de fluxo de caixa descontado. O modelo permite o cálculo do valor da marca de um produto, em particular, bem como o cálculo do valor da marca da empresa. Além disso, o modelo possibilita o estabelecimento da relação entre o mindset do cliente e a avaliação do desempenho de marca no mercado, comparando a marca de seus concorrentes. A integração entre valor da marca baseado no consumidor e valor da marca baseado na firma permite estimar o retorno financeiro das ações de marketing, verificando a contribuição de cada um dos condutores (consciência de marca, qualidade percebida, lealdade à marca, valor percebido, personalidade da marca e associações organizacionais) ao valor marca. / Although there is a consensus about brand equity importance, a single, uniformly accepted estimation model has not yet emerged, neither from consumer-based brand equity or firm or financial-based brand equity perspectives. Hence, marketing professionals are still challenged to estimate the value of the brand. Furthermore, it is important to build a brand equity estimation model, which detects the consumers’ perceptions and also presents a monetary estimation of brand equity, satisfying shareholders’ requirements. Most of the existent consumer-based brand equity models do not offer a monetary estimation of brand equity and many firm-based brand equity models do not observe consumers’ perceptions. Most of them do not evaluate the brands’ performance in future periods of time. This research developed a model that permits estimation of brand equity observing the consumers’ brand choices probabilities (purchase maintenance and brand-switching), by applying the Markov Matrix. The brand-switching matrix was estimated by a cross-sectional survey, using a logit choice model, analyzing all competing brand. This research also investigated the monetary value of the brand, using the discounted cash flow mechanism. Our model allows the calculation of the value of the brand of a product, in particular, as well as the calculation of the company's brand. Our model enables the establishment of the link between customer mindset and evaluating the performance of brand in market, comparing the brand to its competitors. The integration between consumer-based brand equity and firm or financial-based brand equity allows the estimation of the financial return of marketing actions, checking the contribution of each of the drivers (brand awareness, perceived quality, brand loyalty, perceived value, brand personality and organizational associations) in brand equity.

Este trabalho apresenta proposta de modelo matemático para o problema de expansão do sistema de transmissão baseado no fluxo de carga CC considerando a utilização de links CC e FACTS resolvido através de metodologia de solução que considera a primeira e a segunda lei de Kirchhoff em processo enumerativo de branch-and-bound adaptado. A abordagem possui dois pontos em destaque: i) apresenta uma proposta de modelo matemático com possibilidade da utilização direta em problemas de expansão de linhas de transmissão que possuem tanto linhas de transmissão CA, transformadores, links CC e dispositivos FACTS e ii) é um método exato de solução do problema que garante a otimalidade da resposta e traz uma contribuição ao tradicional método branch-and-bound por incluir relaxações adicionais. O método aplicado aos sistemas de 6 barras de Garver e sistema Sul sudeste Brasileiro de 46 barras apresenta respostas adequadas e o modelo matemático testado em um sistema Garver modificado apresenta novas configurações possíveis com redução do custo total do investimento. / This work proposes a mathematical model to the transmission expansion system problem based on the DC power flow model considering the use of DC links and FACTS that is solved using a solution method considering the first and second Kirchhoff’s Law in an enumerative adapted branch-and-bound process. It is possible to highlight two key aspects of the proposed approach: i) presents a mathematical model that can be directly used on expansion transmission systems problems that have AC transmission lines, transformers, DC links and FACTS and ii) is an exact solution method that guarantees the optimum problems’s solutions and contributes to the traditional branch-and-bound method bringing additional relaxations. The solution method applied to Garver’s six-bus network and southeast Brazilian 46 bus network provides correct answers and the mathematical model tested on a modified Garver’s six-bus network presents new possible configurations that enables overall cost reduction to the problem.

abstract: Modern intelligent transportation systems (ITS) make driving more efficient, easier, and safer. Knowledge of real-time traffic conditions is a critical input for operating ITS. Real-time freeway traffic state estimation approaches have been used to quantify traffic conditions given limited amount of data collected by traffic sensors. Currently, almost all real-time estimation methods have been developed for estimating laterally aggregated traffic conditions in a roadway segment using link-based models which assume homogeneous conditions across multiple lanes. However, with new advances and applications of ITS, knowledge of lane-based traffic conditions is becoming important, where the traffic condition differences among lanes are recognized. In addition, most of the current real-time freeway traffic estimators consider only data from loop detectors. This dissertation develops a bi-level data fusion approach using heterogeneous multi-sensor measurements to estimate real-time lane-based freeway traffic conditions, which integrates a link-level model-based estimator and a lane-level data-driven estimator. Macroscopic traffic flow models describe the evolution of aggregated traffic characteristics over time and space, which are required by model-based traffic estimation approaches. Since current first-order Lagrangian macroscopic traffic flow model has some unrealistic implicit assumptions (e.g., infinite acceleration), a second-order Lagrangian macroscopic traffic flow model has been developed by incorporating drivers’ anticipation and reaction delay. A multi-sensor extended Kalman filter (MEKF) algorithm has been developed to combine heterogeneous measurements from multiple sources. A MEKF-based traffic estimator, explicitly using the developed second-order traffic flow model and measurements from loop detectors as well as GPS trajectories for given fractions of vehicles, has been proposed which gives real-time link-level traffic estimates in the bi-level estimation system. The lane-level estimation in the bi-level data fusion system uses the link-level estimates as priors and adopts a data-driven approach to obtain lane-based estimates, where now heterogeneous multi-sensor measurements are combined using parallel spatial-temporal filters. Experimental analysis shows that the second-order model can more realistically reproduce real world traffic flow patterns (e.g., stop-and-go waves). The MEKF-based link-level estimator exhibits more accurate results than the estimator that uses only a single data source. Evaluation of the lane-level estimator demonstrates that the proposed new bi-level multi-sensor data fusion system can provide very good estimates of real-time lane-based traffic conditions. / Dissertation/Thesis / Doctoral Dissertation Industrial Engineering 2015

La modélisation des phénomènes physiologiques induits par un écoulement, tels que l'écoulement sanguin au travers d'une sténose ou l'écoulement d'air lors de la production de parole, repose souvent sur des théories quasi-unidimensionnelles ou bi-dimensionnelles. Cependant, il est établi que le développement des couches limites dépend de la section transversale. Le but de cette thèse est de modéliser, simuler et caractériser l'importance potentielle de la section transversale sur les écoulements laminaires, contrôlés en pression, en l'absence ou en présence d'une constriction. Des coordonnées de translation sont utilisées pour obtenir des solutions pour des écoulement visqueux au travers d'une section de forme arbitraire. Cette paramétrisation est appliquée à la résolution des équations physiques pour des formes à deux et à trois dimensions. Un modèle d'écoulement simplifié quasi-tridimensionnel, qui prend en compte les pertes dissipatives par convection, la viscosité et la forme de la section est présenté et appliqué à la description de l'écoulement le long d'une sténose. Des données expérimentales et issues de simulations numériques sont collectées afin de caractériser l'influence de la forme de la section transversale dans le cas d'une constriction. simulation numérique sont comparées. / Physical models of physiological flow-induced phenomena, such as blood flow through a stenosis or air flow during human speech production, often rely on a quasi-one-dimensional or two-dimensional flow model, so that details of the cross section shape are neglected. Nevertheless, boundary layer development is known to depend on the cross section shape. The aim of this thesis is to model, simulate and characterize the potential impact of the cross section shape for pressure-driven laminar channel flow without and with constriction. Stretched coordinates are introduced to obtain viscous flow solutions for channels with an arbitrary cross section. The proposed cross section shape parametrization is applied to solve physical equations for two-dimensional and three-dimensional shapes. A simplified quasi-three-dimensional flow model, which accounts for kinetic losses, viscosity and the cross section shape, is presented and applied to describe the flow through a stenosis. Finally, flow data are gathered experimentally and numerically in order to characterize the influence of the cross section shape in the case of a constricted channel. Modeled, experimental and numerical data are compared.

Embora haja um consenso sobre a importância do valor da marca, um modelo de estimação único e uniformemente aceito ainda não surgiu, nem na perspectiva baseada no cliente ou consumidor nem na perspectiva da firma ou financeira. Assim, os profissionais de marketing ainda são desafiados a estimar o valor da marca. Além disso, é importante para a construção de um modelo de estimativa de valor da marca detectar as percepções dos consumidores e também apresentar uma estimativa monetária do valor da marca, satisfazendo às exigências de financistas, contabilistas e acionistas empresariais. A maioria dos modelos de valor da marca baseado no consumidor existentes não oferece uma estimativa monetária do valor da marca e muitos modelos de valor da marca baseado na firma não observam as percepções dos consumidores. A maioria deles não avalia o desempenho das marcas em futuros períodos de tempo. Esta pesquisa desenvolveu um modelo que permite estimar o valor da marca observando as probabilidades de escolha (manutenção ou troca) de marca pelos consumidores, com a aplicação da Matriz de Troca Markov. A matriz de troca de marca foi estimada por um estudo transversal, utilizando um modelo de escolha logit, analisando todas as marcas competidoras no mercado. Esta pesquisa também investigou o valor monetário da marca, utilizando o mecanismo de fluxo de caixa descontado. O modelo permite o cálculo do valor da marca de um produto, em particular, bem como o cálculo do valor da marca da empresa. Além disso, o modelo possibilita o estabelecimento da relação entre o mindset do cliente e a avaliação do desempenho de marca no mercado, comparando a marca de seus concorrentes. A integração entre valor da marca baseado no consumidor e valor da marca baseado na firma permite estimar o retorno financeiro das ações de marketing, verificando a contribuição de cada um dos condutores (consciência de marca, qualidade percebida, lealdade à marca, valor percebido, personalidade da marca e associações organizacionais) ao valor marca. / Although there is a consensus about brand equity importance, a single, uniformly accepted estimation model has not yet emerged, neither from consumer-based brand equity or firm or financial-based brand equity perspectives. Hence, marketing professionals are still challenged to estimate the value of the brand. Furthermore, it is important to build a brand equity estimation model, which detects the consumers’ perceptions and also presents a monetary estimation of brand equity, satisfying shareholders’ requirements. Most of the existent consumer-based brand equity models do not offer a monetary estimation of brand equity and many firm-based brand equity models do not observe consumers’ perceptions. Most of them do not evaluate the brands’ performance in future periods of time. This research developed a model that permits estimation of brand equity observing the consumers’ brand choices probabilities (purchase maintenance and brand-switching), by applying the Markov Matrix. The brand-switching matrix was estimated by a cross-sectional survey, using a logit choice model, analyzing all competing brand. This research also investigated the monetary value of the brand, using the discounted cash flow mechanism. Our model allows the calculation of the value of the brand of a product, in particular, as well as the calculation of the company's brand. Our model enables the establishment of the link between customer mindset and evaluating the performance of brand in market, comparing the brand to its competitors. The integration between consumer-based brand equity and firm or financial-based brand equity allows the estimation of the financial return of marketing actions, checking the contribution of each of the drivers (brand awareness, perceived quality, brand loyalty, perceived value, brand personality and organizational associations) in brand equity.