Submitted by JOSIANE SANTOS DE OLIVEIRA (josianeso) on 2018-11-08T13:01:52Z No. of bitstreams: 1 João Eduardo Sampaio_.pdf: 5481805 bytes, checksum: ff4fd651d904071e9a30223e3222c4dc (MD5) / Made available in DSpace on 2018-11-08T13:01:52Z (GMT). No. of bitstreams: 1 João Eduardo Sampaio_.pdf: 5481805 bytes, checksum: ff4fd651d904071e9a30223e3222c4dc (MD5) Previous issue date: 2018-08-23 / Nenhuma / O Brasil precisa de um setor siderúrgico eficiente e competitivo para enfrentar a concorrência externa. A siderurgia é um ramo da metalurgia responsável pela fabricação do aço, e dentre os processos produtivos do setor, destaca-se o processo de laminação do aço, que utiliza fornos de reaquecimento. Esta pesquisa emprega a modelagem com as técnicas do Pensamento Sistêmico e da Dinâmica de Sistemas na formulação de um modelo computacional no contexto dos fornos de reaquecimento. A partir da validação do modelo, são utilizadas a Análise Envoltória de dados, para avaliar a eficiência técnica, e a regressão Tobit, para identificar variáveis estatisticamente significantes. Essas variáveis são usadas para definição dos cenários simulados. Posteriormente, as eficiências dos cenários são avaliadas por meio de estatística descritiva. Também são avaliados alvos e folgas e é testada a hipótese de igualdade da média com o teste de Welch e Post-Hoc Kruskal-Wallis. Finalmente, é realizada a análise explicativa e, com a aplicação da técnica computacional da Rede Neural Artificial, são identificadas as variáveis prevalentes da eficiência técnica do forno de reaquecimento. Tal estudo possibilita e estimula o planejamento, a gestão e a tomada de decisão a partir da análise das melhores opções. Permite, ainda, a tomada de ações com base no conhecimento prévio, contribuindo para iniciativas pontuais e focadas na competitividade. / Brazil needs an efficient and competitive steel sector to face external competition. The siderurgy is a branch of metallurgy responsible for steelmaking, and among the productive processes in the industry the steelmaking process that uses the reheating furnaces can be highlighted. This research employs the modeling with the techniques of Systemic Thinking and Systems Dynamics in the formulation of a computational model in the context of reheating furnaces. Then, using the validated model, Data Envelopment Analysis was used, evaluating the technical efficiency and the use of the Tobit regression of statistically significant variables. These variables are used to define the simulated scenarios. Subsequently, the scenarios efficiencies were evaluated by means of descriptive statistics, evaluated targets and backlash and tested the hypothesis of equality of the average with the test of Welch and Post-Hoc Kruskal-Wallis. Finally, the explanatory analysis and identified with the application of the computational technique of the Artificial Neural Network are the prevalent variables of the technical efficiency of the reheating furnace. This study enables and stimulates planning, management and decision making based on the analysis of the best options and allows the taking of actions based on previous knowledge, and thus contributes to specific initiatives focused on competitiveness.

Peen forming é um processo de conformação plástica a frio de laminas ou painéis metálicos através do impacto de um jato regulado de pequenas esferas de aço em sua superfície, a fim de produzir uma curvatura pré-determinada. A aplicação da técnica de shot peening como um processo de conformação já é conhecida da indústria desde a década de 1940, mas a demanda crescente por produtos de grande confiabilidade tem impulsionado o desenvolvimento de novas pesquisas visando o seu aperfeiçoamento e automação. . O planejamento do processo de peen forming requer medição e controle de diversas variáveis relacionadas à dinâmica do jato de granalhas e à sua interação com o material a ser conformado. Conforme demonstrado por diversos autores, a velocidade de impacto é uma das variáveis que mais contribui para a formação do campo de tensões residuais que leva o material a se curvar. Neste trabalho é apresentado um modelo dinâmico simplificado que descreve o movimento de um grande número de pequenas esferas arrastadas por um fluxo de ar em regime permanente e sujeitas a múltiplas colisões entre si e com a peça a ser conformada. Simulações deste modelo permitiram identificar a correlação entre o campo de velocidades das granalhas e os demais parâmetros do processo. Mediante a aplicação da técnica de projeto de experimentos pôde-se estimar os valores dos parâmetros que otimizam o processo. Ao final, elaborou-se um algoritmo que permite realizar o planejamento de processos de peen forming, ou seja, determinar os valores desses parâmetros, de modo tal a produzir uma curvatura pré-determinada em uma placa metálica originalmente plana. / Peen forming is a plastic cold work process of shaping a metallic sheet or panel through the impact of a regulated blast of small round steel shots on its surface, in order to produce a previously desired curvature. The application of the shot peening as a forming process has been a known technique in the industry since the decade of 1940, but the increasing demand for products of high reliability have pushed the development of new research in order to enhance and automate it. Peen forming process planning requires the measurement and control of several variables concerning the dynamics of the shot jet and its interaction with the piece to be shaped. As previously shown by several authors, impact velocity is one of the variables that most contribute to the development of the residual stress field that causes the material to bend. In this article we present a simplified dynamical model describing the motion of a large number of small spheres (shot) dragged by an air flow in steady conditions and exposed to multiple collisions with each other and with the piece to be shaped. Computer simulations of this model allowed to identify correlations between the shot field velocity and the parameters of the process. Applying design of experiments techniques it was possible to estimate the value of parameters that optimize the process. It was, then, elaborated an algorithm that enables peen forming process planning, allowing the determination of the parameters, in order to make a predetermined bending in a metallic plate originally plane.

<p dir="ltr">The safe and reliable delivery of electricity is critical for the functioning of our modern society. However, high-impact, low-probability (HILP) catastrophic events (such as extreme weather caused by climate change, or cyber-physical attacks) pose an ever-growing threat to the power grid. At the same time, modern advancements in computational capabilities, communication infrastructure, and measurement technologies provide opportunities for new operation and control strategies that enhance the resilience of electric power systems to such HILP events. In this work, optimization-based operation and control approaches are proposed to improve resilience in two power systems applications. First, a real-time linearized-trajectory model-predictive controller (LTMPC) is developed for ensuring voltage, frequency, and transient (rotor angle) stability in systems engineered to operate as microgrids. Such microgrids are capable of seamlessly transitioning from grid-connected operation to an islanded mode and thus, enhance system resilience. The proposed LTMPC enables rapid deployment of such systems by reducing engineering costs and development time while maintaining stable operation. On the other hand, some power systems, such as distribution feeders, are not designed to operate as standalone microgrids. For these cases, a method is proposed for forming ad-hoc microgrids from intact sections of the damaged feeder in the aftermath of a HILP event. A feeder operating center-on-a-laptop (FOCAL) is introduced that coordinates the control of possibly hundreds of inverter-interfaced distributed energy resources (e.g., rooftop solar, battery storage) to improve system resilience. Theoretical analysis as well as numerical case studies and simulations of the proposed strategies are presented for both applications.</p>

The evidence from the literature suggests that Information Technology adoption (IT) governance in organisations is still a challenge. The diversity of application and the ever-increasing use of IT results in making decisions on IT adoption a major challenge for organisations. The decision about using a particular technology from an organisational perspective is problematic since individual users have different worldviews. The implicit assumption in IT adoption literature is that stakeholders always reach consensus during IT adoption decision making in organisations. This study explored the existing models and frameworks in order to develop a preliminary improved IT adoption governance framework. This study used a case study sequential explanatory mixed methods research approach to validate the preliminary IT adoption governance framework. The first validation phase of the framework was done using a quantitative approach followed by the second validation phase based on qualitative interviews. The last validation was done after integrating the quantitative and qualitative results to produce the refined framework. The results suggest that the developed framework may improve IT adoption governance in organisations. The results showed that the framework components facilitate IT adoption governance in organisations. The results also suggest that the components have an association with each other except for the Technology Acceptance Model component. The results indicate that stakeholder participation and hard systems thinking components have a strong predictive impact on IT governance framework component perception in organisations. The study results suggest that IT adoption decision makers need to balance different stakeholders’ demands during IT adoption decision making in organisations. The framework helps in that regard by reconciling different stakeholders’ demands through collective IT adoption decision making. The strength of the framework is its integration of theories from various disciplines in understanding stakeholder expectations. On that basis the framework is in a better position to offer more insight into understanding challenges of IT adoption decision making than existing frameworks and models. The framework offers a potentially valuable basis for future research in IT adoption decision making in organisations. The results suggest that the framework may facilitate IT adoption in organisations using different components. / Information Science / D. Litt. et Phil. (Information systems)

The evidence from the literature suggests that Information Technology adoption (IT) governance in organisations is still a challenge. The diversity of application and the ever-increasing use of IT results in making decisions on IT adoption a major challenge for organisations. The decision about using a particular technology from an organisational perspective is problematic since individual users have different worldviews. The implicit assumption in IT adoption literature is that stakeholders always reach consensus during IT adoption decision making in organisations. This study explored the existing models and frameworks in order to develop a preliminary improved IT adoption governance framework. This study used a case study sequential explanatory mixed methods research approach to validate the preliminary IT adoption governance framework. The first validation phase of the framework was done using a quantitative approach followed by the second validation phase based on qualitative interviews. The last validation was done after integrating the quantitative and qualitative results to produce the refined framework. The results suggest that the developed framework may improve IT adoption governance in organisations. The results showed that the framework components facilitate IT adoption governance in organisations. The results also suggest that the components have an association with each other except for the Technology Acceptance Model component. The results indicate that stakeholder participation and hard systems thinking components have a strong predictive impact on IT governance framework component perception in organisations. The study results suggest that IT adoption decision makers need to balance different stakeholders’ demands during IT adoption decision making in organisations. The framework helps in that regard by reconciling different stakeholders’ demands through collective IT adoption decision making. The strength of the framework is its integration of theories from various disciplines in understanding stakeholder expectations. On that basis the framework is in a better position to offer more insight into understanding challenges of IT adoption decision making than existing frameworks and models. The framework offers a potentially valuable basis for future research in IT adoption decision making in organisations. The results suggest that the framework may facilitate IT adoption in organisations using different components. / Information Science / D. Litt. et Phil. (Information systems)

It is argued that key to gender empowerment and the success of women in leadership is the exploration of the work-family interface which serves to enhance the understanding of issues faced by women leaders as they navigate through their domestic and management roles. It is also contended that work-family scholarship move beyond the study of objective characteristics, and the overt conscious level of functioning of the interface, to an understanding of the intra-psychic experiences of individuals. Recognising the preoccupation with the role strain perspective, it is argued that work-family scholarship adopts a more balanced view and considers the positive and negative effects of participating in multiple roles. Hence the general aim of this qualitative study was to understand the systems psychodynamics underlying the work-family interface that influence the processes of enrichment and conflict among managerial women in the public sector. In the empirical study, data was gathered using the organisational role analysis method, and analysed by means of systems psychodynamic discourse analysis. Six themes and their related subthemes were identified, namely anxiety and conflict, identity, boundary management, authority, role and task. The findings explored the manner in which these behavioural dynamics of participants, and their family and organisational systems interacted, mutually influencing each other, and shaping the way managerial women found, made and took up their domestic and management roles at the work-family interface. This led to resource generation and role enhancement, or resource depletion and role strain in the role (domestic or management). Through relatedness, projection and introjection between the systems and roles, the quality of life in one role influenced the other role, promoting enrichment and conflict at the interface. This study concluded that both enrichment and conflict occur at the interface. While participants oscillated between experiencing enrichment and conflict, some participants experienced more enrichment than conflict, while others experienced more conflict than enrichment at the work-family interface. The extent to which enrichment or conflict occurred between the systems was mediated by participants’ ability to self-contain, and/or the receiving system’s ability to serve as a “good enough” holding environment containing the anxieties experienced in the other role. / D. Litt et Phil. (Industrial & Organisational Psychology)

It is argued that key to gender empowerment and the success of women in leadership is the exploration of the work-family interface which serves to enhance the understanding of issues faced by women leaders as they navigate through their domestic and management roles. It is also contended that work-family scholarship move beyond the study of objective characteristics, and the overt conscious level of functioning of the interface, to an understanding of the intra-psychic experiences of individuals. Recognising the preoccupation with the role strain perspective, it is argued that work-family scholarship adopts a more balanced view and considers the positive and negative effects of participating in multiple roles. Hence the general aim of this qualitative study was to understand the systems psychodynamics underlying the work-family interface that influence the processes of enrichment and conflict among managerial women in the public sector. In the empirical study, data was gathered using the organisational role analysis method, and analysed by means of systems psychodynamic discourse analysis. Six themes and their related subthemes were identified, namely anxiety and conflict, identity, boundary management, authority, role and task. The findings explored the manner in which these behavioural dynamics of participants, and their family and organisational systems interacted, mutually influencing each other, and shaping the way managerial women found, made and took up their domestic and management roles at the work-family interface. This led to resource generation and role enhancement, or resource depletion and role strain in the role (domestic or management). Through relatedness, projection and introjection between the systems and roles, the quality of life in one role influenced the other role, promoting enrichment and conflict at the interface. This study concluded that both enrichment and conflict occur at the interface. While participants oscillated between experiencing enrichment and conflict, some participants experienced more enrichment than conflict, while others experienced more conflict than enrichment at the work-family interface. The extent to which enrichment or conflict occurred between the systems was mediated by participants’ ability to self-contain, and/or the receiving system’s ability to serve as a “good enough” holding environment containing the anxieties experienced in the other role. / D. Litt et Phil. (Industrial and Organisational Psychology)

<div>The security, resilience and sustainability of water supply in urban areas are of major concern in cities around the world. Their dynamics and long-term trajectories result from external change processes, as well as adaptive and maladaptive management practices aiming to secure urban livelihoods. This dissertation examines the dynamics of urban water systems from a social-ecological-technical systems perspective, in which infrastructure and institutions mediate the human-water-ecosystem relationship. </div><div><br></div><div>The three concepts of security, resilience and sustainability are often used interchangeably, making the achievement of goals addressing such challenges somewhat elusive. This becomes evident in the international policy arena, with the UN Sustainable Development Goals being the most prominent example, in which aspirations for achieving the different goals for different sectors lead to conflicting objectives. Similarly, the scientific literature remains inconclusive on characterizations and quantifiable metrics. These and other urban water challenges facing the global urban community are discussed, and research questions and objectives are introduced in Section 1. </div><div><br></div><div>In Section 2, I suggest distinct definitions of urban water security, resilience and sustainability: Security refers to the state of system functioning regarding water services; resilience refers to ability to absorb shocks, to adapt and transform, and therefore describes the dynamic, short- to medium-term system behavior in response to shocks and disturbances; sustainability aims to balance the needs in terms of ecology and society (humans and the economic systems they build) of today without compromising the ability to meet the needs of future generations. Therefore, sustainability refers to current and long-term impacts on nature and society of maintaining system functions, and therefore affects system trajectories. I suggest that sustainability should include not only local effects, but consider impacts across scales and sectors. I propose methods for the quantification of urban water security, resilience and sustainability, an approach for modeling dynamic water system behavior, as well as an integrated framework combining the three dimensions for a holistic assessment of urban water supply systems. The framework integrates natural, human and engineered system components (“Capital Portfolio Approach”) and is applied to a range of case study cities selected from a broad range of hydro-climatic and socio-economic regions on four continents. Data on urban water infrastructure and services were collected from utilities in two cities (Amman, Jordan; Ulaanbaatar, Mongolia), key stakeholder interviews and a household survey conducted in Amman. Publicly available, empirical utility data and globally accessible datasets were used to support these and additional case studies. </div><div><br></div><div>The data show that community adaptation significantly contributes to urban water security and resilience, but the ability to adapt is highly heterogeneous across and within cities, leading to large inequality of water security. In cities with high levels of water security and resilience, adaptive capacity remains latent (inactive), while water-insecure cities rely on community adaptation for the self-provision of services. The framework is applied for assessing individual urban water systems, as well as for cross-city comparison for different types of cities. Results show that cities fall along a continuous gradient, ranging from water insecure and non-resilient cities with inadequate service provision prone to failure in response to extant shock regimes, to water secure and resilient systems with high levels of services and immediate recovery after shocks. Although limited by diverse constraints, the analyses show that urban water security and resilience tend to co-evolve, whereas sustainability, which considers local and global sustainable management, shows highly variable results across cities. I propose that the management of urban water systems should maintain a balance of security, resilience and sustainability.</div><div><br></div><div>The focus in Section 3 is on intra-city patterns and mechanisms, which contribute to urban water security, resilience and sustainability. In spite of engineering design and planning, and against common expectations, intra-city patterns emerge from self-organizing processes similar to those found in nature. These are related to growth processes following the principle of preferential attachment and functional efficiency considerations, which lead to Pareto power-law probability distributions characteristic of scale-free-like structures. Results presented here show that such structures are also present in urban water distribution and sanitary sewer networks, and how deviation from such specific patterns can result in vulnerability towards cascading failures. In addition, unbounded growth, unmanaged demand and unregulated water markets can lead to large inequality, which increases failure vulnerability. </div><div><br></div><div>The introduction of infrastructure and institutions for providing urban water services intercedes and mediates the human-water relationship. Complexity of infrastructural and institutional setups, growth patterns, management strategies and practices result in different levels of disconnects between citizens and the ecosystems providing freshwater resources. “Invisibility” of services to citizens results from maximized water system performance. It can lead to a lack of awareness about the effort and underlying infrastructure and institutions that operate for delivering services. Data for the seven cities illustrate different portfolios of complexity, invisibility and disconnection. Empirical data gathered in a household survey and key stakeholder interviews in Amman reveals that a misalignment of stakeholder perceptions resulting from the lack of information flow between citizens and urban managers can be misguiding and can constrain the decision-making space. Unsustainable practices are fostered by invisibility and disconnection and exacerbate the threats to urban water security and resilience. Such challenges are investigated in the context of urban water system traps: the poverty and the rigidity trap. Results indicate that urban water poverty is associated with local unsustainability, while rigidity traps combined with urban demand growth gravitate towards global unsustainability. </div><div><br></div><div>Returning to the city-level in Section 4, I investigate urban water system evolution. The question how the trajectories of urban water security, resilience and sustainability can be managed is examined using insights from hydrological and social-ecological systems research. I propose an “Urban Budyko Landscape”, which compares urban water supply systems to hydrological catchments and highlights the different roles of supply- and demand-management of water and water-related urban services. A global assessment of 38 cities around the world puts the seven case studies in perspective, emphasizing the relevance of the proposed framework and the representative, archetypal character of the selected case studies. </div><div><br></div><div>Furthermore, I examine how managing for the different dimensions of the CPA (capital availability, robustness, risk and sustainable management) determines the trajectories of urban water systems. This is done by integrating the CPA with the components of social-ecological system resilience, which explain how control of the different components determines the movement of systems through states of security and resilience in a stability landscape. Finally, potential feedbacks resulting from the global environment are investigated with respect to the role that globally sustainable local and regional water management can play in determining the trajectories of urban water systems. These assessments demonstrate how the impact of supply-oriented strategies reach beyond local, regional and into global boundaries for meeting a growing urban demand, and come at the cost of global sustainability and communities elsewhere.</div><div><br></div><div>Despite stark differences between individual cities and large heterogeneities within cities, convergent trends and patterns emerge across systems and are revealed through application of the proposed concepts and frameworks. The implications of these findings are discussed in Section 5, and are summarized here as follows: </div><div>1) The management of urban water systems needs to move beyond the security and resilience paradigms, which focus on current system functioning and short-term behavior. Sustaining a growing global, urban population will require addressing the long-term, cross-scale and inter-sector impacts of achieving and maintaining urban water security and resilience. </div><div>2) Emergent spatial patterns are driven by optimization for the objective functions. Avoiding traps, cascading failure, extreme inequality and maintaining global urban livability requires a balance of supply- and demand-management, consideration of system complexity, size and reach (i.e., footprint), as well as internal structures and management strategies (connectedness and modularity).</div><div>3) Urban water security and resilience are threatened by long-term decline, which necessitates the transformation to urban sustainability. The key to sustainability lies in experimentation, modularization and the incorporation of interdependencies across scales, systems and sectors.</div><div><br></div>

Indiana University-Purdue University Indianapolis (IUPUI) / This thesis proposes an automated grid-based alignment system utilizing lasers and an array of light-detecting photodiodes. The intent is to create an inexpensive and scalable alignment system for pick-and-place robotic systems. The system utilizes the transformation matrix, geometry, and trigonometry to determine the movements to align the robot with a grid-based array of photodiodes. The alignment system consists of a sending unit utilizing lasers, a receiving module consisting of photodiodes, a data acquisition unit, a computer-based control system, and the robot being aligned. The control system computes the robot movements needed to position the lasers based on the laser positions detected by the photodiodes. A transformation matrix converts movements from the coordinate system of the grid formed by the photodiodes to the coordinate system of the robot. The photodiode grid can detect a single laser spot and move it to any part of the grid, or it can detect up to four laser spots and use their relative positions to determine rotational misalignment of the robot. Testing the alignment consists of detecting the position of a single laser at individual points in a distinct pattern on the grid array of photodiodes, and running the entire alignment process multiple times starting with different misalignment cases. The first test provides a measure of the position detection accuracy of the system, while the second test demonstrates the alignment accuracy and repeatability of the system. The system detects the position of a single laser or multiple lasers by using a method similar to a center-of-gravity calculation. The intensity of each photodiode is multiplied by the X-position of that photodiode. The summed result from each photodiode intensity and position product is divided by the summed value of all of the photodiode intensities to get the X-position of the laser. The same thing is done with the Y-values to get the Y-position of the laser. Results show that with this method the system can read a single laser position value with a resolution of 0.1mm, and with a maximum X-error of 2.9mm and Y-error of 2.0mm. It takes approximately 1.5 seconds to process the reading. The alignment procedure calculates the initial misalignment between the robot and the grid of photodiodes by moving the robot to two distinct points along the robot’s X-axis so that only one laser is over the grid. Using these two detected points, a movement trajectory is generated to move that laser to the X = 0, Y = 0 position on the grid. In the process, this moves the other three lasers over the grid, allowing the system to detect the positions of four lasers and uses the positions to determine the rotational and translational offset needed to align the lasers to the grid of photodiodes. This step is run in a feedback loop to update the adjustment until it is within a permissible error value. The desired result for the complete alignment is a robot manipulator positioning within ±0.5mm along the X and Y-axes. The system shows a maximum error of 0.2mm in the X-direction and 0.5mm in the Y-direction with a run-time of approximately 4 to 5 minutes per alignment. If the permissible error value of the final alignment is tripled the alignment time goes down to 1 to 1.5 minutes and the maximum error goes up to 1.4mm in both the X and Y-directions. The run time of the alignment decreases because the system runs fewer alignment iterations.