An integrated design approach to power systems : from power flows to electricity markets

Power system is at the brink of change. Engineering needs, economic forces and environmental factors are the main drivers of this change. The vision is to build a smart electrical grid and a smarter market mechanism around it to fulfill mandates on clean energy. Looking at engineering and economic issues in isolation is no longer an option today; it needs an integrated design approach. In this thesis, I shall revisit some of the classical questions on the engineering operation of power systems that deals with the nonconvexity of power flow equations. Then I shall explore some issues of the interaction of these power flow equations on the electricity markets to address the fundamental issue of market power in a deregulated market environment. Finally, motivated by the emergence of new storage technologies, I present an interesting result on the investment decision problem of placing storage over a power network. The goal of this study is to demonstrate that modern optimization and game theory can provide unique insights into this complex system. Some of the ideas carry over to applications beyond power systems.

Contact and channel modelling using part and function libraries in a function-based design approach

To support the development and analysis of engineering designs at the embodiment stage, designers work iteratively with representations of those designs as they consider the function and form of their constituent parts. Detailed descriptions of "what a machine does" usually include flows of forces and active principles within the technical system, and their localization within parts and across the interfaces between them. This means that a representation should assist a designer in considering form and function at the same time and at different levels of abstraction. This paper describes a design modelling approach that enables designers to break down a system architecture into its subsystems and parts, while assigning functions and flows to parts and the interfaces between them. In turn, this may reveal further requirements to fulfil functions in order to complete the design. The approach is implemented in a software tool which provides a uniform, computable language allowing the user to describe functions and flows as they are iteratively discovered, created and embodied. A database of parts allows the user to search for existing design solutions. The approach is illustrated through an example: modelling the complex mechanisms within a humanoid robot. Copyright © 2010 by ASME.

Stack ventilation in multi-storey atrium buildings: A dimensionless design approach

Using a simplified mathematical model, a preliminary design strategy for steady stack ventilation in multi-storey atrium buildings is developed. By non-dimensionalising the governing equations of flow, two key dimensionless parameters are identified - a ventilation performance indicator, λ, and atrium enhancement parameter, E - which quantify the performance of the ventilation system and the effectiveness of the atrium in assisting flows. Analytical expressions are determined to inform the vent sizes needed to provide the desired balance between indoor air temperature, ventilation flow rate and heat inputs for any distribution of occupants within the building, and also to ensure unidirectional flow. Dimensionless charts for determining the required combination of design variables are presented with a view to informing first-order design guidance for naturally ventilated buildings. © 2013 Elsevier Ltd.

A mechanical design approach to testing fluid turbulence over a rough surface

Senior thesis written for Oceanography 444

Transferring ownership of public housing to existing tenants: a mechanism design approach

This paper explores situations where tenants in public houses, in a specific neighborhood, are given the legislated right to buy the houses they live in or can choose to remain in their houses and pay the regulated rent. This type of legislation has been passed in many European countries in the last 30-35 years (the U.K. Housing Act 1980 is a leading example). The main objective with this type of legislation is to transfer the ownership of the houses from the public authority to the tenants. To achieve this goal, selling prices of the public houses are typically heavily subsidized. The legislating body then faces a trade-off between achieving the goals of the legislation and allocating the houses efficiently. This paper investigates this specific trade-off and identifies an allocation rule that is individually rational, equilibrium selecting, and group non-manipulable in a restricted preference domain that contains “almost all” preference profiles. In this restricted domain, the identified rule is the equilibrium selecting rule that transfers the maximum number of ownerships from the public authority to the tenants. This rule is preferred to the current U.K. system by both the existing tenants and the public authority. Finally, a dynamic process for finding the outcome of the identified rule, in a finite number of steps, is provided.

The autotelic experience : a design approach to user experience

Si les principes d’utilisabilité guident la conception de solutions de design interactif pour s’assurer que celles-ci soient « utilisables », quels principes guident la conception d’objets interactifs pour s’assurer que l’expérience subjective de l’usager (UX) soit adéquate et mémorable? Que manque-t-il au cadre de l‘UX pour expliquer, comprendre, et anticiper en tant que designer une expérience mémorable (‘an experience’; Dewey, 1934)? La question centrale est issue d’une double problématique : (1) le cadre théorique de l’UX est incomplet, et (2) les processus et capacités des designers ne sont pas considérés et utilisés à leur pleine capacité en conception UX. Pour répondre à cette question, nous proposons de compléter les modèles de l’UX avec la notion d’expérience autotélique qui appartient principalement à deux cadres théoriques ayant bien cerné l’expérience subjective, soit l’expérience optimale (ou Flow) de Csikszentmihalyi (1988) et l’expérience esthétique selon Schaeffer (2001). L’autotélie est une dimension interne du Flow alors qu’elle couvre toute l’expérience esthétique. L’autotélie est une expérience d’éveil au moment même de l’interaction. Cette prise de conscience est accompagnée d’une imperceptible tension de vouloir faire durer ce moment pour faire durer le plaisir qu’il génère. Trois études exploratoires ont été faites, s’appuyant sur une analyse faite à partir d’un cadre théorique en trois parties : le Flow, les signes d’activité non verbale (les gestes physiques) et verbale (le discours) ont été évalués pour voir comment ceux-ci s’associent. Nos résultats tendent à prouver que les processus spatiaux jouent un rôle de premier plan dans l’expérience autotélique et par conséquent dans une UX optimale. De plus, ils suggèrent que les expériences pragmatique et autotélique sont ancrées dans un seul et même contenu, et que leur différence tient au type d’attention que le participant porte sur l’interaction, l’attention ordinaire ou de type autotélique. Ces résultats nous ont menés à proposer un modèle pour la conception UX. L’élément nouveau, resté jusqu’alors inaperçu, consiste à s’assurer que l’interface (au sens large) appelle une attitude réceptive à l’inattendu, pour qu’une information puisse déclencher les processus spatiaux, offrant une opportunité de passer de l’attention ordinaire à l’attention autotélique. Le nouveau modèle ouvre la porte à une meilleure valorisation des habiletés et processus du designer au sein de l’équipe multidisciplinaire en conception UX.

On insurance markets with endogenous information acquisition: A robust mechanism design approach

Neste trabalho propomos a aplicação das noções de equilíbrio da recente literatura de desenho de mecanismo robusto com aquisição de informação endógena a um problema de divisão de risco entre dois agentes. Através deste exemplo somos capazes de motivar o uso desta noção de equilíbrio, assim como discutir os efeitos da introdu ção de uma restrição de participação que seja dependente da informação. A simplicidade do modelo nos permite caracterizar a possibilidade de implementar a alocação Pareto efiente em termos do custo de aquisição da informação. Além disso, mostramos que a precisão da informação pode ter um efeito negativo sobre a implementação da alocação efi ciente. Ao final, sao dados dois exemplos específicos de situações nas quais este modelo se aplica.